gebhart/patrepeval huggingface dataset:
Titanium–Imido Complexes with Pendant Groups – Synthesis, Characterization, and Evaluation of Their Role as Precatalysts for Ethylene Polymerization (2011)

Abstract The synthesis of several anilines (Ar PG NH 2 ) substituted in the ortho position with pendant groups (PGs, terminated by potentially coordinative arene, thienyl, furanyl, or pyridyl functionalities) was accomplished by a two‐ to five‐step synthesis in good yields. The Ar PG NH 2 proligands were used for the preparation of titanium complexes starting from Ti(NMe 2 ) 4 in the presence of excess Me 3 SiCl. Complexes of the general formula [Ti(NAr PG )Cl 2 (NHMe 2 ) x ] ( x = 1, 2), which are supported by a terminal imido functionality, were obtained in 60–95 % yield. The nature of the pendant group influences the coordination mode of the ligand. Although only monodentate imido linkages have been observed with ligands where PG is arene, thiophene, and furan, ligands with substituted pyridine sidearms lead to chelating imido–donor functionalities. The potential hemilabile behavior of some imido–donor ligands, which results from the reversible coordination of the side arm, was studied by variable‐temperature 1 H NMR spectroscopy. These compounds were evaluated as precatalysts for ethylene polymerization with various aluminum cocatalysts. Ultrahigh molecular‐weight (UHMW) polyethylenes were obtained. All compounds were fully characterized by spectroscopic methods ( 1 H and 13 C NMR), and elemental analysis and some were also characterized by single‐crystal X‐ray diffraction.
Pharmacological evaluation of the role of cyclooxygenase isoenzymes on the micturition reflex following experimental cystitis in rats (2000)

Prostanoids, generated from cyclooxygenase (COX) isoenzymes, play a role in the physiological function of the lower urinary tract and are important mediators of inflammatory hyperalgesia. The present work evaluates the effects of the COX-1/COX-2 inhibitor dexketoprofen as well as of a selective COX-2 inhibitor, NS-398, on urodynamic function following endotoxin (LPS) or cyclophosphamide (CYP)-induced inflammation of the urinary bladder. The application of arachidonic acid (330 microgram rat(-1)) onto the serosal surface of the urinary bladder in control rats elicited bladder contractions which could be blocked in a dose-dependent manner by dexketoprofen (0.1 - 3 mg kg(-1), i.v.) but not by NS-398 (0.2 - 6 mg kg(-1), i.v. ). Dexketoprofen (3 mg kg(-1), i.v.) decreased the micturition frequency and increased the pressure threshold for triggering the micturition either when administered within 15 min or 3 h following surgery in control animals. NS-398 (6 mg kg(-1), i.v.) decreased the micturition frequency and increased the pressure threshold when administered 3 h but not 15 min following surgery. Administration of LPS (2 mg kg(-1), i.v., 90 - 120 min) increased both the micturition frequency and the pressure threshold for triggering the micturition reflex. Changes in urodynamic parameters induced by LPS were prevented by doses of either dexketoprofen (1 mg kg(-1), i.v.) or NS-398 (2 mg kg(-1), i.v.) which were ineffective in control animals. Pretreatment with CYP (150 mg kg(-1), i.p., 48 h) increased the micturition frequency, pressure threshold, and the minimal intravesical pressure but decreased the mean amplitude of micturition contractions. In CYP-treated rats, dexketoprofen (1 mg kg(-1), i.v.) or NS-398 (2 mg kg(-1), i.v.) blocked the CYP-induced urodynamic changes with exception of the micturition contraction amplitude. These results indicate that COX-1 may be involved in modulating the threshold for activating the micturition reflex in the normal rats and also demonstrates that inhibition of COX-2 prevents or reverses the urodynamic changes associated with bladder inflammation induced either by surgery, LPS or CYP treatments.
Bayesian Joint Synchronization and Localization Based on Asymmetric Time-stamp Exchange (2020)

In this work, we study the joint synchronization and localization (sync&loc) of Mobile Nodes (MNs) in ultra dense networks. In particular, we deploy an asymmetric time-stamp exchange mechanism between the MNs and the Access Nodes (ANs), that, traditionally, provides us with information about the MNs' clock offset and skew. However, information about the distance between an AN and a MN is also intrinsic to the propagation delay experienced by exchanged time-stamps. In addition, we utilize Angle of Arrival (AoA) estimation to determine the incoming direction of time-stamp exchange packets, which gives further information about the MNs' location. Finally, we employ Bayesian Recursive Filtering (BRF) to combine the aforementioned pieces of information and jointly estimate the position and clock parameters of the MNs. The simulation results indicate that the Root Mean Square Errors (RMSEs) of position and clock offset estimation are kept below 1 meter and 1 nanosecond, respectively.
Expression of the TOL plasmid xylS gene in Pseudomonas putida occurs from a alpha 70-dependent promoter or from alpha 70- and alpha 54-dependent tandem promoters according to the compound used for growth (1996)

Growth of Pseudomonas putida (pWWO) on alkylbenzoates requires the expression of the meta pathway operon, which is mediated by the XylS protein after binding of a benzoate effector. Alternatively, in cells growing on toluene or its aromatic alcohols, overexpression of xylS mediated by XylR activated by these compounds leads to overproduction of the XylS regulator, which even in the absence of benzoate effectors stimulates transcription from the meta cleavage pathway operon promoter. We show here that in bacteria growing on glycerol or alkylbenzoates, the xylS gene is expressed at a low but constitutive level from a newly found sigma 70-dependent promoter called Ps2. The amount of XylS protein made from the transcript originated from Ps2 was sufficient to allow high levels of expression from the meta cleavage pathway operon promoter when the cells were grown in the presence of 3-methylbenzoate. The transcription initiation point of the transcript generated from Ps2 mapped 9 bp upstream from the proposed ATG of the xylS gene; this transcript contains the ribosome-binding site. The Ps2 promoter was located 110 bp downstream from a previously described sigma54-dependent promoter located upstream from the xylS open reading frame, now called Ps1. In cells growing on toluene or benzyl alcohols, the XylS regulator is overproduced as a consequence of increased expression of the gene through the effect of the two promoters working in tandem: the newly found sigma 70-dependent promoter, whose expression is XylR and toluene independent, and the sigma 54-dependent promoter, whose expression is dependent on XylR activated by its effectors. This expression pathway of the xylS gene explains why sigma 54-deficient P. putida bearing the wild-type TOL plasmid, or the wild-type P. putida strain bearing a TOL plasmid with a knocked-out xylR gene, can grow on alkylbenzoates. Until now this has been one of the unresolved paradoxes in the transcriptional control of the TOL meta cleavage pathway.
P4‐308: Pyroglutamate‐Modified Amyloid‐β(3‐42) Forms Transient a‐Helices Prior to Amyloid Formation (2016)

Amyloid-β (Aβ) peptides play a central role in the pathology of Alzheimer’s disease as the major constituents of extracellular deposits in the brain. These peptides are highly heterogeneous in size and modification, however N-terminally truncated pyroglutamate-modified Aβ (pEAβ) has been described to be a dominant isoform of senile plaques. Compared to non-truncated Aβ species, pEAβ is more resistant to degradation, shows higher toxicity and has increased aggregation propensity. To date, there is only little insight about the structure of pEAβ and its difference to the non-truncated isoform of Aβ. We established a protocol for recombinant expression and purification of natural abundant as well as isotopically 15N and 13C,15N labeled pEAβ variants for structural studies. Aggregation kinetics of Aβ species were monitored by thioflavin-T (ThT) assays. Circular dichroism (CD) and heteronuclear multi-dimensional nuclear magnetic resonance (NMR) spectroscopy in solution state were used for structural analysis and secondary structure determination of pEAβ monomers. CD data indicated that pEAβ(3-42) had increased tendency to form β-sheet-rich structures under solution conditions, where Aβ(1-42) formed α-helices. The data were confirmed by ThT assays showing increased aggregation of pEAβ(3-42) as compared to Aβ(1-42). The formation to pEAβ(3-42) affected the NMR chemical shifts of 30% of the total amino acid residues when compared to Aβ(1-42). Some peak intensities of pEAβ(3-42) were drastically decreased as compared to its non-modified isoform indicating the presence of exchange processes. Secondary structure prediction by NMR chemical shift analysis indicated that soluble pEAβ(3-42) contained two helical regions connected by a linker. These α-helical pEAβ(3-42) monomers were instable due to intermolecular peptide-peptide interactions ultimately leading to fibrillation. With this study, we have gained insights into the driving force of pEAβ to form oligomers and fibrils more rapidly than Aβ. There is evidence that pEAβ forms transient α-helices as an intermediate to β-sheet formation and fibrillation. The results suggest that the N-terminal modification towards pEAβ has a significant effect on secondary structure elements resulting in a severe tendency to form β-sheet-rich structures extending to fibrils via transient α-helices. These transient intermediates seem to be on-pathway of the highly helical monomeric conformation to the amyloidogenic fibrils.
NMR studies of the exocyclic 1,N6-ethenodeoxyadenosine adduct (.epsilon.dA) opposite deoxyguanosine in a DNA duplex. .epsilon.dA(syn).cntdot.dG(anti) pairing at the lesion site (1991)

Proton NMR studies are reported on the complementary d(C-A-T-G-G-G-T-A-C).d(G-T-A-C-epsilon A-C-A-T-G) nonanucleotide duplex (designated epsilon dA.dG 9-mer duplex), which contains exocyclic adduct 1,N6-ethenodeoxyadenosine positioned opposite deoxyguanosine in the center of the helix. The present study focuses on the alignment of dG5 and epsilon dA14 at the lesion site in the epsilon dA.dG 9-mer duplex at neutral pH. This alignment has been characterized by monitoring the NOEs originating from the NH1 proton of dG5 and the H2, H5, and H7/H8 protons of epsilon dA14 in the central d(G4-G5-G6).d(C13-epsilon A14-C15) trinucleotide segment of the epsilon dA.dG 9-mer duplex. These NOE patterns establish that epsilon dA14 adopts a syn glycosidic torsion angle that positions the exocyclic ring toward the major groove edge while all the other bases including dG5 adopt anti glycosidic torsion angles. We detect a set of intra- and interstrand NOEs between protons (exchangeable and nonexchangeable) on adjacent residues in the d(G4-G5-G6).d(C13-epsilon A14-C15) trinucleotide segment which establish formation of right-handed helical conformations on both strands and stacking of the dG5(anti).epsilon dA14(syn) pair between stable dG4.dC15 and dG6.dC13 pairs. The energy-minimized conformation of the central d(G4-G5-G6).d(C13-epsilon A14-C15) segment establishes that the dG5(anti).epsilon dA14(syn) alignment is stabilized by two hydrogen bonds from the NH1 and NH2-2 of dG5(anti) to N9 and N1 of epsilon dA14(syn), respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
Discrepancy between Effects of in vivo and in vitro Administration of Gammaglobulin on Phagocytic Killing of <i>Streptococcus pneumonia</i><i>e</i> in an Antibody-Deficient Serum (1988)

Phagocytic killing of Streptococcus pneumoniae serotypes 6A, 14, 18C, 19F and 23F was investigated in the dysgammaglobulinemic serum of a patient with recurrent pneumococcal infections. Previous studies with this serum had established combined IgG2, IgG4 and IgA deficiency, deficiency with regard to specific antipolysaccharide antibodies and essentially normal complement functions. Phagocytic killing of all serotypes was reduced in the patient's serum. Addition of immunoglobulin in vitro enhanced both classical and alternative complement pathway mediated opsonization. In constitution experiments neither purified Clq nor CRP influenced phagocytic killing. Surprisingly, intramuscular administration of a fairly small dose of gammaglobulin to the patient was associated with a rapid increase in the serum opsonic activity for serotype 23F. The increased opsonization occurred before specific anticapsular antibodies were detectable in serum. The findings suggest that the possible effects of gammaglobulin treatment may not exclusively be related to the acquisition of serotype-specific antibodies.
Adsorbed Natural Gas Storage with Activated Carbons Made from Illinois Coals and Scrap Tires (1997)

Activated carbons for natural gas storage were produced from Illinois bituminous coals (IBC-102 and IBC-106) and scrap tires by physical activation with steam or CO2 and by chemical activation with KOH, H3PO4, or ZnCl2. The products were characterized for N2-BET area, micropore volume, bulk density, pore size distribution, and volumetric methane storage capacity (Vm/Vs). Vm/Vs values for Illinois coal-derived carbons ranged from 54 to 83 cm3/cm3, which are 35−55% of a target value of 150 cm3/cm3. Both granular and pelletized carbons made with preoxidized Illinois coal gave higher micropore volumes and larger Vm/Vs values than those made without preoxidation. This confirmed that preoxidation is a desirable step in the production of carbons from caking materials. Pelletization of preoxidized IBC-106 coal, followed by steam activation, resulted in the highest Vm/Vs value. With roughly the same micropore volume, pelletization alone increased Vm/Vs of coal carbon by 10%. Tire-derived carbons had Vm/Vs values ranging from 44 to 53 cm3/cm3, lower than those of coal carbons due to their lower bulk densities. Pelletization of the tire carbons increased bulk density up to 160%. However, this increase was offset by a decrease in micropore volume of the pelletized materials, presumably due to the pellet binder. As a result, Vm/Vs values were about the same for granular and pelletized tire carbons. Compared with coal carbons, tire carbons had a higher percentage of mesopores and macropores.
Chemists: Public Outreach Is an Essential Investment of Time, Not a Waste of It (2014)

In this chapter, we discuss the state of the public image of chemistry and some of the potential consequences of its deterioration. We explain why it is important that chemists engage the public to educate citizens about science and communicate the value of scientific research. Next, as an example of how chemists can interact with the public in a meaningful manner related to their research, we discuss the development and implementation of a multifaceted outreach program by our group at Caltech. We close with suggestions for how chemists can create their own outreach activities and how our field can encourage this work by recognizing and rewarding it.
Determination of diarylheptanoids from Alpinia officinarum (lesser galangal) by HPLC with photodiode array and electrochemical detection (2005)

Normal-phase column chromatography followed by semi-preparative reversed-phase HPLC has been used to isolate, from the rhizomes of Alpinia officinarum, five diarylheptanoids identified as 5-hydroxy-7-(4"-hydroxy-3"-methoxyphenyl)-1-phenyl-3-heptanone, 5-methoxy-7-(4"-hydroxy-3"-methoxyphenyl)-1-phenyl-3-heptanone, 7-(4"-hydroxyphenyl)-1-phenylhept-4-en-3-one, 7-(4"-hydroxy-3"-methoxyphenyl)-1-phenyl-hept-4-en-3-one, 1,7-diphenylhept-4-en-3-one. The levels of these five diarylheptanoids in root material were determined quantitatively by HPLC with UV detection and the assay methods so developed were simple, rapid and accurate. Four of the diarylheptanoids could also be detected by HPLC with electrochemical detection (ECD) in the oxidative mode, and ECD was found to have a higher sensitivity than photodiode array detection.
High-dimensional quantum communication with twisted photons propagating in a fiber link (2018)

Quantum communication (QC) represents a key enabler for many quantum applications. However, low information rates and short propagation distances, limit the development of this ﬁeld and its practical applications. High-dimensional (Hi-D) QC can address these challenges enhancing the information rate and the systems error tolerance. We transmit, for the ﬁrst time ever, Hi-D quantum states prepared in four orbital angular momentum (OAM) modes in a 1.2 km long OAM-carrying ﬁber. Furthermore, we successfully implement a real-time decoy-state Hi-D QKD protocol, and demonstrate the highest secret key rate and longest transmission distance of OAM-QKD presented to date
Overview of Results From the Largest Clinical Trial for Dysphagia Treatment Efficacy (2008)

Abstract Information presented herein provides an overview of the largest randomized clinical trial ever completed in dysphagia. The two-part sequential randomized clinical trial studied the effect of two common dysphagia interventions (chin tuck and thickened liquids) for immediate prevention of aspiration during videofluorographic assessment and also for the incidence of pneumonia at 3-months for patients with Parkinson's disease and/or dementia. Results indicated that thickened liquids (nectar-thick or honey-thick) prevented aspiration during the radiographic study more frequently than chin-down posture; however, both interventions were equally successful at preventing pneumonia. Adverse events such as urinary tract infection and dehydration were more common with thickened liquids. Median length of hospital stay due to pneumonia was three times longer for patients drinking honey-thick liquids compared to nectar-thick and chin-tuck arms of the study. Several important secondary outcomes are discussed as well as implications for clinical practice. The reader is encouraged to refer to other published works for detailed information that is highlighted in this overview.
Protein and DNA-Based Vaccines With the NY-ESO-1 Antigen in Cancer Patients (2005)

s: Abstracts for the 20th Annual Scientific Meeting of the International Society for Biological Therapy of Cancer (Primary Authors are Italicized): TURNING IMMUNIZATION INTO TUMOR REGRESSION: OBSTACLES AND STRATEGIES
Head circumference and incident Alzheimer’s disease: Modification by apolipoprotein E (2002)

To the Editor:

Borenstein Graves et al. point to an intriguing association between small head circumference and a substantially elevated risk of AD in carriers of the ApoE -E4 genotype.1 They conclude that smaller head circumference leads to earlier age at onset of AD, and suggest that this distinctive relationship might reflect a …
Frequency weighting for MPEG-4 AVC/H.264 (2003)

Joint Video Team (JVT) was established to standardize next video coding technology. ITU-T H.26L (TML8) was adopted as the start point of the standard, and Joint Model (JM) was released. High quality video, not only for professional equipments but also for consumer applications, is very important target for JVT codec. However, H.26L was tested relatively lower bit rate. It is found that there are several problems due to quantization in order to support high quality video. In this paper, two extensions of quantization to support high quality video, which are frequency weighting matrix and extension of quantization table, are proposed. The frequency weighting matrix adds flexibility to the transform and quantization process by providing substantial coding efficiency without sacrificing the visual quality. It is possible to change quantization characteristic for each frequency depending on the sensitivity of human visual system. Encoder can compress video more efficiently. By extending the quantization table, encoder can use smaller and larger q_scale. In order to confirm the advantage of the proposal, simulations were performed to evaluate both PSNR and subjective quality. It was verified that proposed method is able to reduce bit rate keeping the same visual quality.
ARTSCIENCE: Creativity in the Post-Google Generation by David Edwards. Harvard University Press, 2008. 194 pp. ISBN: 978-0-6740-2625-4 (2008)

August 01 2008 ARTSCIENCE: Creativity in the Post-Google Generation by David Edwards. Harvard University Press, 2008. 194 pp. ISBN: 978-0-6740-2625-4 David G. Stork David G. Stork Search for other works by this author on: This Site Google Scholar Author and Article Information David G. Stork Online ISSN: 1530-9282 Print ISSN: 0024-094X © 2008 Massachusetts Institute of Technology2008 Leonardo (2008) 41 (4): 403–404. https://doi.org/10.1162/leon.2008.41.4.403 Cite Icon Cite Permissions Share Icon Share Facebook Twitter LinkedIn Email Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Search Site Citation David G. Stork; ARTSCIENCE: Creativity in the Post-Google Generation by David Edwards. Harvard University Press, 2008. 194 pp. ISBN: 978-0-6740-2625-4. Leonardo 2008; 41 (4): 403–404. doi: https://doi.org/10.1162/leon.2008.41.4.403 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll JournalsLeonardo Search Advanced Search This content is only available as a PDF. © 2008 Massachusetts Institute of Technology2008 Article PDF first page preview Close Modal You do not currently have access to this content.
Effects of Combined Treatment of MG132 and Scriptaid on Early and Term Development of Porcine Somatic Cell Nuclear Transfer Embryos (2012)

Although improving, the efficiency of producing offspring by somatic cell nuclear transfer (SCNT) is still low (<1.5%). Our laboratory has demonstrated that histone deacetylase inhibitor (Scriptaid) treatment of reconstructed embryos enhances blastocyst formation and cloning efficiency in pigs. It has also been shown that proteasomal inhibitor MG132 treatment for 2 h after activation of oocytes increases blastocyst rate and pregnancy rate. The current experiment was carried out to determine the effects of combined MG132 and Scriptaid treatment on early embryo development in vitro and on term development in vivo. Immediately after electrofusion and activation, SCNT oocytes were treated with 0, 1, or 10 μM MG132 for 2 h in the presence of 500 nM Scriptaid, washed and treated with Scriptaid for an additional 14 to 15 h, then cultured in porcine zygote medium 3 (PZM3) until day 6. There was no difference in percent cleavage (58.1 ± 7.2%, 62.7 ± 7.2%, and 62.5 ± 7.2%) on day 2, or total cell number (23.1 ± 2.2, 24.0 ± 2.0, and 24.5 ± 2.3 for the 0, 1, and 10 μM MG132 groups, respectively) on day 6 among the three groups. Interestingly, there was no difference in percentage of blastocysts between the 0 (18.5±4.7%) and 1 (25.1 ± 4.7%) μM MG132 treatment groups; however, compared with the 10 μM MG132 group (14.0 ± 4.7%), more embryos from the 1 μM MG132 group developed into blastocysts (p<0.05). To determine the effects on term development in vivo, two MG132 groups were included (0 and 1 μM MG132), and embryos were treated as above and transferred into synchronized surrogates after treatment. There was no difference in the oocyte-donor cell fusion rate, number of embryos transferred, pregnancy rate at days 28, 60, and at term, pigs delivered per embryo transfer, litter size, body weight at birth, nor cloning efficiency between the Scriptaid-alone control and MG132+Scriptaid combined groups. In summary, the combined treatment of MG132 and Scriptaid did not improve term development compared to Scriptaid treatment alone.