gebhart/patrepeval huggingface dataset:
Excimer formation and luminescence in conducting polymers (1997)

Some four decades ago it was discovered that a pair of molecules could form an excimer, that is, a complex between an excited state of molecule and a molecule of the same species in the ground state. Excimer formation has been found to be quite common for organic molecules in concentrated solution or in thin films. Since the recent discovery that some conducting polymers, notably poly(phenylene vinylene), PPV, and some of its derivatives, can emit sufficient light to be of interest for devices such as light-emitting diodes, a great deal of effort has been devoted to studying photogeneration in these polymers. Some of the phenomena observed have been interpreted as indicating the generation ofexcimers involving adjacent chains. There is also evidence for the formation in some other conducting polymers of aggregates, complexes that are stable when the molecules or chains are in the ground state, and that involve more than two molecules or chains. Because the extent of excimer or aggregate formation is apparently quite sample dependent, their properties, and even their existence in some of the conducting polymers, are controversial. In what follows we will first review the evidence that establishes the existence of excimers and aggregates in these materials. We will then consider the reasons for the big differences observed between different derivatives and different samples. In the context of the proposed light-emitting diodes, photovoltaic devices and possibly lasers involving conducting polymer films, excimer or aggregate formation appears in many cases, if not generally, to be an undesirable effect and we will discuss methods for decreasing it.
Mechanism and Regulation of Class Switch Recombination (2008)

Antibody class switching occurs in mature B cells in response to antigen stimulation and costimulatory signals. It occurs by a unique type of intrachromosomal deletional recombination within special G-rich tandem repeated DNA sequences [called switch, or S, regions located upstream of each of the heavy chain constant (C(H)) region genes, except Cdelta]. The recombination is initiated by the B cell-specific activation-induced cytidine deaminase (AID), which deaminates cytosines in both the donor and acceptor S regions. AID activity converts several dC bases to dU bases in each S region, and the dU bases are then excised by the uracil DNA glycosylase UNG; the resulting abasic sites are nicked by apurinic/apyrimidinic endonuclease (APE). AID attacks both strands of transcriptionally active S regions, but how transcription promotes AID targeting is not entirely clear. Mismatch repair proteins are then involved in converting the resulting single-strand DNA breaks to double-strand breaks with DNA ends appropriate for end-joining recombination. Proteins required for the subsequent S-S recombination include DNA-PK, ATM, Mre11-Rad50-Nbs1, gammaH2AX, 53BP1, Mdc1, and XRCC4-ligase IV. These proteins are important for faithful joining of S regions, and in their absence aberrant recombination and chromosomal translocations involving S regions occur.
High definition profiling of mammalian DNA methylation by array capture and single molecule bisulfite sequencing (2009)

DNA methylation stabilizes developmentally programmed gene expression states. Aberrant methylation is associated with disease progression and is a common feature of cancer genomes. Presently, few methods enable quantitative, large-scale, single-base resolution mapping of DNA methylation states in desired regions of a complex mammalian genome. Here, we present an approach that combines array-based hybrid selection and massively parallel bisulfite sequencing to profile DNA methylation in genomic regions spanning hundreds of thousands of bases. This single molecule strategy enables methylation variable positions to be quantitatively examined with high sampling precision. Using bisulfite capture, we assessed methylation patterns across 324 randomly selected CpG islands (CGI) representing more than 25,000 CpG sites. A single lane of Illumina sequencing permitted methylation states to be definitively called for &gt;90% of target sties. The accuracy of the hybrid-selection approach was verified using conventional bisulfite capillary sequencing of cloned PCR products amplified from a subset of the selected regions. This confirmed that even partially methylated states could be successfully called. A comparison of human primary and cancer cells revealed multiple differentially methylated regions. More than 25% of islands showed complex methylation patterns either with partial methylation states defining the entire CGI or with contrasting methylation states appearing in specific regional blocks within the island. We observed that transitions in methylation state often correlate with genomic landmarks, including transcriptional start sites and intron-exon junctions. Methylation, along with specific histone marks, was enriched in exonic regions, suggesting that chromatin states can foreshadow the content of mature mRNAs.
A viral regulator of glycoprotein complexes contributes to human cytomegalovirus cell tropism (2015)

Viral glycoproteins mediate entry of enveloped viruses into cells and thus play crucial roles in infection. In herpesviruses, a complex of two viral glycoproteins, gH and gL (gH/gL), regulates membrane fusion events and influences virion cell tropism. Human cytomegalovirus (HCMV) gH/gL can be incorporated into two different protein complexes: a glycoprotein O (gO)-containing complex known as gH/gL/gO, and a complex containing UL128, UL130, and UL131 known as gH/gL/UL128-131. Variability in the relative abundance of the complexes in the virion envelope correlates with differences in cell tropism exhibited between strains of HCMV. Nonetheless, the mechanisms underlying such variability have remained unclear. We have identified a viral protein encoded by the UL148 ORF (UL148) that influences the ratio of gH/gL/gO to gH/gL/UL128-131 and the cell tropism of HCMV virions. A mutant disrupted for UL148 showed defects in gH/gL/gO maturation and enhanced infectivity for epithelial cells. Accordingly, reintroduction of UL148 into an HCMV strain that lacked the gene resulted in decreased levels of gH/gL/UL128-131 on virions and, correspondingly, decreased infectivity for epithelial cells. UL148 localized to the endoplasmic reticulum, but not to the cytoplasmic sites of virion envelopment. Coimmunoprecipitation results indicated that gH, gL, UL130, and UL131 associate with UL148, but that gO and UL128 do not. Taken together, the findings suggest that UL148 modulates HCMV tropism by regulating the composition of alternative gH/gL complexes.
Submucosal gland dysfunction as a primary defect in cystic fibrosis (2004)

It has been proposed that defective submucosal gland function in CF airways is a major determinant of CF airway disease. We tested the hypothesis that submucosal gland function is defective early in CF subjects with minimal clinical disease. Functional assays of gland fluid secretion rate and viscosity were performed on freshly obtained nasal biopsies from 6 CF subjects and 5 non-CF controls (age range 2-22 years). Secretions from individual submucosal glands were visualized by light/fluorescence microscopy after orienting and immobilizing biopsy specimens in a custom chamber. The viscosity of freshly secreted gland fluid after pilocarpine, measured by fluorescence recovery after photobleaching of microinjected FITC-dextran, was 4.9 +/- 0.2- vs. 2.2 +/- 0.2-fold greater than water viscosity in CF vs. non-CF specimens, respectively (SE, P<10(-4)). Gland fluid secretion rate in CF specimens, measured by video imaging (4.5+/-0.5 nL/min/gland, n=6), was 2.7-fold reduced compared to non-CF specimens (n=3, P<0.05). Quantitative histology revealed similar size and morphology of submucosal glands in CF and non-CF specimens. Our results suggest that defective airway submucosal gland function is an early, primary defect in CF. Therapies directed at normalizing gland fluid secretion early in CF may thus reduce lung disease.
T-Helper-Cell Proliferative Responses to Whole-Killed Human Immunodeficiency Virus Type 1 (HIV-1) and p24 Antigens of Different Clades in HIV-1-Infected Subjects Vaccinated with HIV-1 Immunogen (Remune) (2000)

The discovery of multiple subtypes of human immunodeficiency virus type 1 (HIV-1) worldwide has created new challenges for the development of both therapeutic and preventive AIDS vaccines. We examined T-helper proliferative responses to HIV-1 clade A, B, C, G, and E whole-killed virus and to HIV-1 clade G and B core (p24) antigens in HIV-1-infected subjects taking potent antiviral drugs who received HIV immunogen (Remune) therapeutic vaccination. Subjects who were immunized mounted strong proliferative responses to both whole virus and core antigens of the different clades. These results suggest that a whole-killed immunogen may have broad applications as a therapeutic as well as a preventive vaccine in the current multiclade HIV-1 pandemic.
Heterocycles. Part VIII. Synthesis of new substituted benz[g]indazoles (1986)

Abstract Aryl aldehydes I reacted with α‐tetralone to give the corresponding 2‐arylidene‐1‐tetralone II. Condensation of the latter chalcones with hydrazine, methylhydrazine and phenylhydrazine produced the corresponding benzo[ g ]indazoles III, V and VI respectively. Acetylation of the 2 H ‐benz[ g ]indazole derivatives III gave the corresponding 2‐acetylated compounds IV. The structure of all products was elucidated by chemical and spectroscopic methods.
Design of Attitude Control Systems for CubeSat-Class Nanosatellite (2013)

We present a satellite attitude control system design using low-cost hardware and software for a 1U CubeSat. The attitude control system architecture is a crucial subsystem for any satellite mission since precise pointing is often required to meet mission objectives. The accuracy and precision requirements are even more challenging for small satellites where limited volume, mass, and power are available for the attitude control system hardware. In this proposed embedded attitude control system design for a 1U CubeSat, pointing is obtained through a two-stage approach involving coarse and fine control modes. Fine control is achieved through the use of three reaction wheels or three magnetorquers and one reaction wheel along the pitch axis. Significant design work has been conducted to realize the proposed architecture. In this paper, we present an overview of the embedded attitude control system design; the verification results from numerical simulation studies to demonstrate the performance of a CubeSat-class nanosatellite; and a series of air-bearing verification tests on nanosatellite attitude control system hardware that compares the performance of the proposed nonlinear controller with a proportional-integral-derivative controller.
Piracetam and levetiracetam: close structural similarities but different pharmacological and clinical profiles (2000)

Piracetam (PIR) and levetiracetam (LEV), an S-enantiomer, are pyrrolidone derivatives that share similar chemical structures but have distinct pharmacological profiles and consequently different clinical uses. Although the mode of action of neither drug has been fully elucidated, they do not interact with inhibitory or excitatory neurotransmission or alter membrane excitability. A brain-specific stereoselective binding site has been identified for which LEV and other S-enantiomers, but not PIR, have high affinity. In preclinical studies, PIR significantly improves learning and memory; in contrast, LEV has less effect but is much more active in preventing seizures. Both drugs have a high therapeutic index and are well tolerated. PIR, a nootropic drug, is used in the therapy of age-related cognitive disturbances and poststroke aphasia. Clinical experience has also shown that at high doses it is effective against cortical myoclonus. LEV is an antiepileptic drug. Clinical trials have confirmed its efficacy in partial seizures and preliminary findings suggest that it is also effective in generalized seizures and myoclonus.
Determinants of intestinal mucosal uptake of short- and medium-chain fatty acids and alcohols (1973)

Uptake rates across the jejunal brush border have been measured for water-soluble fatty acids and alcohols and analyzed to determine the relative roles of the unstirred water layer and the lipid cell membrane as determinants of the intestinal absorptive process. Initial studies involving measurement of time courses of electrical transients developed across the intestine exposed to poorly permeant solute molecules showed no anomalous discrimination of probe molecules of different size or charge. This finding suggests that the diffusion barrier in the intestine can be considered as an unstirred water layer. Next, uptake rates of fatty acid were found to be linear with respect to concentration of the test solute, demonstrated no competitive inhibition or contralateral stimulation, had low temperature dependency, and were insensitive to metabolic inhibition, indicating that uptake proceeds by passive diffusion. Passive permeability coefficients, *P, varied from 22 +/- 1.4 to 395 +/- 9.2 nmoles.min(-1).100 mg(-1).mm(-1) for the saturated fatty acids 2:0 through 12:0 and from 119 +/- 3.3 to 581 +/- 45.2 for the saturated alcohols 6:0 through 10:0. Vigorous stirring of the bulk buffer solution enhanced *P values in direct proportion to chain length while the presence of bile acid micelles depressed apparent permeability coefficients in proportion to fatty acid chain length. These results demonstrate that uptake of short-chain fatty acid monomers is rate limited by the lipid cell membrane but diffusion through the unstirred water layer becomes increasingly rate limiting as the chain length increases. It is also possible to conclude from these data that diffusion through the unstirred water layer becomes totally rate limiting for uptake of long-chain fatty acid monomers of physiological importance.
Mutations at the splice sites of exon 14 of MET gene: a new target for sarcomatoid carcinomas? (2016)

The pulmonary sarcomatoid carcinoma (SC) represents less than 1% of non-small cell lung cancer (NSCLC). Its prognosis is worse than that of other histological subtypes, by its particular aggressiveness and resistance to conventional therapies (1,2). Therefore, alternative therapies are sought, via immunotherapy or targeting molecular abnormalities. Liu et al . performed in Asian patients whole exome sequencing of 10 samples from SC followed by targeted sequencing of a set of five key genes on a validation cohort with 26 samples (3). The first analysis of the 10 samples showed two samples with mutations at the splice sites of exon 14 of MET . Subsequent targeted mutation screening of all 36 tumors confirmed these 2 mutations and identified 6 additional tumors with DNA alterations leading to exon 14 skipping.
Competition between tetracycline and tRNA at both P and A sites of the ribosome of Escherichia coli (1987)

Fluorescence anisotropy studies performed on 6-demethylchlortetracycline, binding to the ribosome of E. coli in competition with tRNA at the P site or at both P and A sites, have provided a quantitative assessment in situ of the interaction of this antibiotic with the A site and have demonstrated that there is also an interaction between tetracycline and the P site.
Photoplethysmographic derivation of respiratory rate: a review of relevant physiology (2011)

An abnormal respiratory rate is often the earliest sign of critical illness. A reliable estimate of respiratory rate is vital in the application of remote telemonitoring systems, which may facilitate early supported discharge from hospital or prompt recognition of physiological deterioration in high-risk patient groups. Traditional approaches use analysis of respiratory sinus arrhythmia from the electrocardiogram (ECG), but this phenomenon is predominantly limited to the young and healthy. Analysis of the photoplethysmogram (PPG) waveform offers an alternative means of non-invasive respiratory rate monitoring, but further development is required to enable reliable estimates. This review conceptualizes the challenge by discussing the effect of respiration on the PPG waveform and the key physiological mechanisms that underpin the derivation of respiratory rate from the PPG.
Cannabidiol, a Cannabis sativa constituent, as an anxiolytic drug (2012)

Future clinical trials involving patients with different anxiety disorders are warranted, especially of panic disorder, obsessive-compulsive disorder, social anxiety disorder, and post-traumatic stress disorders. The adequate therapeutic window of CBD and the precise mechanisms involved in its anxiolytic action remain to be determined.
<title>Application of the active-pixel-sensor concept to guidance and navigation</title> (1993)

Charge-coupled devices (CCDs) have been used extensively in the past in star trackers and fine guidance systems. A new technology, the active pixel sensor, is a possible successor to CCDs. This technology potentially features the same sensitivity and performance of the CCD with additional improvements. These improvements include random access capability, easy window-of- interest readout, non-destructive readout for signal-to-noise improvement, high radiation tolerance, simplified clocking voltages, and easy integration with other on-chip signal processing circuitry. The state-of-the-art of this emerging technology and its potential application to guidance and navigation systems is discussed.
Quantitative Analysis of Human Immunodeficiency Virus Type 1-Infected CD4+Cell Proteome: Dysregulated Cell Cycle Progression and Nuclear Transport Coincide with Robust Virus Production (2007)

Relatively little is known at the functional genomic level about the global host response to human immunodeficiency virus type 1 (HIV-1) infection. Microarray analyses by several laboratories, including our own, have revealed that HIV-1 infection causes significant changes in host mRNA abundance and regulation of several cellular biological pathways. However, it remains unclear what consequences these changes bring about at the protein level. Here we report the expression levels of approximately 3,200 proteins in the CD4(+) CEMx174 cell line after infection with the LAI strain of human immunodeficiency virus type 1 (HIV-1); the proteins were assessed using liquid chromatography-mass spectrometry coupled with stable isotope labeling and the accurate mass and time tag approach. Furthermore, we found that 687 (21%) proteins changed in abundance at the peak of virus production at 36 h postinfection. Pathway analysis revealed that the differential expression of proteins was concentrated in select biological pathways, exemplified by ubiquitin-conjugating enzymes in ubiquitination, carrier proteins in nucleocytoplasmic transport, cyclin-dependent kinase in cell cycle progression, and pyruvate dehydrogenase of the citrate cycle pathways. Moreover, we observed changes in the abundance of proteins with known interactions with HIV-1 viral proteins. Our proteomic analysis captured changes in the host protein milieu at the time of robust virus production, depicting changes in cellular processes that may contribute to virus replication. Continuing analyses are expected to focus on blocking virus replication by targeting these pathways and their effector proteins.
Preemptive Low‐frequency Stimulation Decreases the Incidence of Amygdala‐kindled Seizures (2005)

The dramatic decrease in the incidence of stage 5 seizures in fully kindled animals after preemptive LFS strongly suggests that LFS may be an effective therapy for the prevention of seizures in patients with epilepsy.
Tibiofemoral force following total knee arthroplasty: Comparison of four prosthesis designs in vitro (2007)

Despite ongoing evolution in total knee arthroplasty (TKA) prosthesis design, restricted flexion continues to be common postoperatively. Compressive tibiofemoral force during flexion is generated through the interaction between soft tissues and prosthesis geometry. In this study, we compared the compressive tibiofemoral force in vitro of four commonly used prostheses: fixed-bearing PCL (posterior cruciate ligament)-retaining (PFC), mobile-bearing posterior-stabilized (PS), posterior-stabilized with a High Flex femoral component (HF), and mobile-bearing PCL-sacrificing (LCS). Fourteen fresh-frozen cadaver knee joints were tested in a passive motion rig, and tibiofemoral force measured using a modified tibial baseplate instrumented with six load cells. The implants without posterior stabilization displayed an exponential increase in force after 90 degrees of flexion, while PS implants maintained low force throughout the range of motion. The fixed-bearing PFC prosthesis displayed the highest peak force (214 +/- 68 N at 150 degrees flexion). Sacrifice of the PCL decreased the peak force to a level comparable with the LCS implant. The use of a PCL-substituting post and cam system reduced the peak force up to 78%, irrespective of whether it was a high-flex or a standard PS knee. However, other factors such as preoperative range of motion, knee joint kinematics, soft tissue impingement, and implantation technique play a role in postoperative knee function. The present study suggests that a posterior-stabilized TKA design might be advantageous in reducing soft tissue tension in deep flexion. Further research is necessary to fully understand all factors affecting knee flexion after TKA.
L-ornithine L-aspartate for people with cirrhosis and hepatic encephalopathy (2016)

This is a protocol for a Cochrane Review (Intervention). The objectives are as follows: To assess the beneficial and harmful effects of L-ornithine L-aspartate versus placebo, no intervention, or other active interventions for people with cirrhosis and hepatic encephalopathy.
Borazine Polymers. B-N Linked Borazine Rings and Polyborazylene Oxides (1962)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTBorazine Polymers. B-N Linked Borazine Rings and Polyborazylene OxidesRoss I. Wagner and James L. BradfordCite this: Inorg. Chem. 1962, 1, 1, 99–106Publication Date (Print):February 1, 1962Publication History Published online1 May 2002Published inissue 1 February 1962https://pubs.acs.org/doi/10.1021/ic50001a019https://doi.org/10.1021/ic50001a019research-articleACS PublicationsRequest reuse permissionsArticle Views511Altmetric-Citations27LEARN 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