gebhart/patrepeval huggingface dataset:
Differentiation of arcA, arcB, and cpxA mutant phenotypes of Escherichia coli by sex pilus formation and enzyme regulation (1989)

In Escherichia coli, mutations in arcA (dye) or arcB anaerobically derepress the synthesis of a multitude of enzymes of aerobic function, and mutations in arcA or cpxA impair F-pilus formation. It is thought that arcA encodes a promoter-recognizing protein, whereas arcB and cpxA encode sensor proteins which interact with the arcA product. In this study we found that anaerobic growth of a wild-type F' strain decreased the synthesis of both the enzymes and the pilus. Although the two arcA mutants examined were both anaerobically derepressed in the enzymes and impaired in aerobic pilus formation as expected, one mutant hyperproduced the pilus anaerobically. The two arcB mutants examined showed normal pilus formation when grown aerobically. When grown anaerobically they developed more pili than the wild-type strain did when grown aerobically. When a cpxA mutant was examined for synthesis of two aerobic enzymes, normal regulation was found. The available data suggest the following. The arcA product anaerobically represses certain genes of aerobic function and activates certain genes related to F function. It appears that the arcB product senses the redox or energy state; absence of the gene function shifts the arcA product to the nonrepressive form for enzyme synthesis for aerobic pathways. The cpxA product, on the other hand, senses the sexual state; absence of the gene function shifts the arcA product to the inactive form for F-pilus synthesis.
A Highly Efficient Asymmetric Synthesis of Homotaurine Derivatives via Diastereoselective Ring-Opening of γ-Sultones (2004)

A highly efficient asymmetric synthesis of α,γ-substituted γ-amino sulfonates via diastereoselective ring-opening of enantiopure α,γ-substituted γ-sultones with inversion of configuration at the attacked γ-carbon is described. In the key step sodium azide is used as the nucleophilic nitrogen source. Secondary and tertiary γ-amino sulfonates were synthesized in very good yields and excellent diastereo- and enantiomeric excesses (de, ee ≥98%).
Highly Transparent and Conductive Zinc-Stannate Thin Films Prepared by RF Magnetron Sputtering (1994)

Highly transparent and conductive zinc-stannate thin films, ZnSnO 3 , have been prepared by rf magnetron sputtering using a target composed of ZnO–SnO 2 ( SnO 2 , 78 wt%). A resistivity as low as 4×10 -3 Ω·cm and an average transmittance above 80% in the visible range were obtained for undoped zinc-stannate films deposited with substrate temperatures ranging from room temperature to 300°C. The zinc-stannate films were relatively more stable in an oxidizing environment at high temperatures than either ZnO or SnO 2 films. In addition, thermal stability in a hydrogen environment was improved over SnO 2 films, and chemical stability in both acidic and basic solutions was improved over ZnO films.
A Real-Time 4-Stream MIMO-OFDM Transceiver: System Design, FPGA Implementation, and Characterization (2008)

When designing complex communication systems, such as MIMO-OFDM transceivers, prototypes have become an important tool for understanding the implementation trade-offs and the system behavior. This paper presents a real-time FPGA prototype for a 4-stream MIMO-OFDM transceiver capable of transmitting 216 Mbit/s in 20 MHz bandwidth. The paper covers all parts of the system from RF to channel decoding and considers both algorithm and implementation aspects. In particular, we discuss the initial parameter estimation, channel estimation, MIMO detection, parameter tracking, and channel decoding. FPGA implementation results are reported along with measurements that demonstrate the throughput of spatial multiplexing with four spatial streams.
CTLA-4 and CD28: similar proteins, neighbouring genes. (1992)

Subtractive cloning and screening yielded a cDNA clone corresponding to a molecule expressed in activated T cells, called CTLA-4. At the protein level, CTLA-4, a single-V-domain member of the immunoglobulin superfamily, was found very homologous to the lymphocyte activation molecule CD28. In particular, the hinge region included the hexamer MYPPPY, completely conserved for both molecules and in mice and humans. By immunizing mice with a human CTLA-4 peptide, an anti-CTLA-4 monoclonal antibody (MAb) was obtained, which enabled to establish the MW of the protein (26 and 40 kDa under reduced and non-reduced conditions respectively) and its preliminary tissue distribution. Also, CTLA-4 and CD28 were very similar at the message and at the gene structure level. The corresponding genes had previously been found to co-map on mouse chromosome IC and on human chromosome 2q33. We show that they can be found on the same yeast artificial chromosomes bearing human genomic DNA, and that they are 25 to 150 kb apart. These marked homologies and gene proximity strongly suggest that CTLA-4 and CD28 are the direct products of a duplication event, and raise the question of the function of CTLA-4.
Effects of DHEA replacement on bone mineral density and body composition in elderly women and men (2000)

The results provide preliminary evidence that DHEA replacement in those elderly women and men who have very low serum DHEAS levels can partially reverse age-related changes in fat mass, fat-free mass, and BMD, and raise the possibility that increases in IGF-I and/or testosterone play a role in mediating these effects of DHEA.
Assembly of storage protein oligomers in the endoplasmic reticulum and processing of the polypeptides in the protein bodies of developing pea cotyledons (1982)

Cotyledons of developing pea seeds (pisum sativum L.) were labeled with radioactive amino acids and glucosamine, and extracts were prepared and separated into fractions rich in endoplasmic reticulum (ER) or protein bodies, The time-course of synthesis of the polypeptides of legumin and vicilin and the site of their assembly into protein oligomers were studied using immunoaffinity gels and sucrose density gradients. When cotyledons were pulse-labeled (1-2 h), newly synthesized vicilin was present as a series of polypeptides with M(r) 60,000-65,000, and newly synthesized vicilin was present as series of polypeptides with M(r) 75,000, 70,000, 50,000, and 49,000. These radioactive polypeptides were found primarily in the ER (Chrispeels et al., 1982, J Cell Biol., 93:5- 14). During a subsequent chase period, newly synthesized reserve proteins were initially present in the protein bodies in the above-named polypeptides. Between 1 and 20 h later, radioactive legumin subunits (M(r) 40,000 and 19,000) and smaller vicilin polypeptides (M(r) 34,000, 30,000, 25,000, 18,000, 14,000, 13,000, and 12,000) appeared in the protein bodies. The appearance of these labeled polypeptides in the protein bodies was not the result of a slow transport from the ER (or cytoplasm). Newly synthesized legumin and vicilin polypeptides were assembled into oligomers of 8S and 7S, respectively, in the ER. They appeared in the protein bodies in these oligomeric forms before the appearance of the smaller polypeptides (M(r) less than 49,000). These results indicate that the smaller vicilin polypeptides (M(r) less than 49,000) arise delayed posttranslational processing of some or all of the larger vicilin polypeptides. The precursors of legumin are completely processed in the protein bodies 2-3 h after their synthesis. The processing of the vicilin precursors is much slower (6-20 h) and only a fraction of the precursor molecules are processed. As a result both large (M(r) more than 49,000) and small polypeptides of vicilin accumulate in the protein bodies, whereas legumin accumulates only as polypeptides of M(r) 40,000 and 19,000.
Synthesis and characterization of a novel and highly efficient light-emitting polymer (1999)

A polymer (TPD-PPV), incorporating both efficient light-emitting and hole transporting moieties has been synthesized. This polymer also possesses excellent film-forming property, good thermal stability, and high electrochemical reversibility and stability. The HOMO-LUMO energy levels were determined by cyclic voltammetry and UV-Vis measurement. The diode with the structure of ITO/CuPc/TPD-PPV/Al showed high rectification ratio (108) and low turn-on voltage (4.2 V). A bright green-yellow light-emission was observed in day-light under forward bias.
Inheritance of Heat Tolerance during Pod Set in Cowpea (1992)

The productivity of cowpea ( Vigna unguiculata (L.) Walp.] can be reduced substantially by hot weather during flowering. Inheritance and heritability of tolerance to heat during reproductive development were studied to develop efficient methods for breeding improved cultivars. Heat tolerant (‘Prima’ and TVu 4552) and heat sensitive (Barnbey 23, ‘Magnolia’ and 7964) cowpea genotypes were chosen for studies of heat tolerance during pod set under hot long days. Parental genotypes, F 1 , F 2 and backcross progenies were evaluated under field conditions in the Imperial Valley of California during the summers of 1987 and 1988, and heat‐tolerant and heat‐sensitive F 2 's were selected in 1987 and evaluated as F 3 families in 1988. Average daily minimum and maximum air temperatures were 24 and 43 °C, respectively, and the photoperiod decreased from 14 h 31 min to 13 h 20 min during flowering. Individual plants were scored for average number of pods per peduncle and plants with ≥ 1.5 (the mean of the value for the most tolerant parent and the average value for the sensitive parents) were classified as heat tolerant. Analyses of pods per peduncle and proportions of tolerant plants for F 1 , F 2 , and backcross populations indicated that heat tolerance is conferred by a single dominant gene in both Prima and TVu 4552. Narrow‐sense heritability obtained from variance components was 0.26. Comparison of pods per peduncle of F 2 plants with their F 3 families from crosses between heat‐tolerant and heat‐sensitive parents gave a realized heritability of 0.27. The low values for heritability were due to large environmental effects on pods per peduncle. Incorporating heat tolerance during pod set into other genetic backgrounds will require family selection in advanced generations to ensure that the trait is fixed, and, to partially overcome selection difficulties caused by environmentally induced variation.
Long acting beta agonists. (1998)

Long acting beta agonists (LABAs) such as salmeterol and eformoterol provide 12 hour bronchodilatation, giving continuous control of asthma symptoms particularly at night. More recent evidence also suggests a role as 'steroid-sparing' agents, allowing control of asthma at lower doses of inhaled corticosteroids (ICS). Providing a sufficient dose of inhaled steroid (in adults around 800 micrograms of belcomethasone or budesonide or 400 micrograms of fluticasone) is used in conjunction with LABAs, there is no evidence of any increase in asthma exacerbation. Cost is the major impediment to the widespread application of these useful agents.
Cell–cell fusion (2007)

Cell-cell fusion is a highly regulated and dramatic cellular event that is required for development and homeostasis. Fusion may also play a role in the development of cancer and in tissue repair by stem cells. While virus-cell fusion and the fusion of intracellular membranes have been the subject of intense investigation during the past decade, cell-cell fusion remains poorly understood. Given the importance of this cell-biological phenomenon, a number of investigators have begun analyses of the molecular mechanisms that mediate the specialized fusion events of a variety of cell types and species. We discuss recent genetic and biochemical studies that are beginning to yield exciting insights into the fusion mechanisms of Saccharomyces cerevisiae mating pairs, Caenorhabditis elegans epithelial cells and gametes, Drosophila melanogaster and mammalian myoblasts, and mammalian macrophages.
Postexposure immunoprophylaxis of primary isolates by an antibody to HIV receptor complex (1999)

mAb B4 is a monoclonal antibody directed against HIV receptor complex. The antibody had broad neutralizing activity against HIV and provided postexposure prophylaxis to hu-peripheral blood leukocyte (PBL)-severe combined immunodeficient mice and chimpanzees. B4 recognized a complex receptor site for HIV on the T cell surface that includes CD4 and also may be influenced by interaction with HIV coreceptors. mAb B4 preferentially neutralized primary HIV-1 isolates compared with T cell line-adapted strains, including syncytium-inducing and non-syncytium-inducing phenotypes, representatives from HIV-1 subtypes A-G, as well as HIV-2, simian immunodeficiency virus, and chimeric simian/human immunodeficiency virus (SHIV). Neutralization was demonstrated in both pre- and postinfection models. The administration of mAb B4 after infectious challenge totally interrupted the infection of hu-PBL-severe combined immunodeficient mice by PBL-grown HIV-1 and the infection of chimpanzees by chimp-adapted HIV-1. This mode of protection suggested that the anti-HIV receptor antibody is efficacious for prophylaxis after exposure to HIV and for prevention of maternal transmission and may be an effective antiretroviral agent for treatment.
A generic system for the Escherichia coli cell‐surface display of lipolytic enzymes (2005)

EstA is an outer membrane-anchored esterase from Pseudomonas aeruginosa. An inactive EstA variant was used as an anchoring motif for the Escherichia coli cell-surface display of lipolytic enzymes. Flow cytometry analysis and measurement of lipase activity revealed that Bacillus subtilis lipase LipA, Fusarium solani pisi cutinase and one of the largest lipases presently known, namely Serratia marcescens lipase were all efficiently exported by the EstA autotransporter and also retained their lipolytic activities upon cell surface exposition. EstA provides a useful tool for surface display of lipases including variant libraries generated by directed evolution thereby enabling the identification of novel enzymes with interesting biological and biotechnological ramifications.
Fast and noninvasive fluorescence imaging of biological tissues in vivo using a flying-spot scanner (2001)

The authors have developed a flying-spot scanner (FSS), for fluorescence imaging of tissues in vivo. The FSS is based on the principles of single-pixel illumination and detection via a raster scanning technique. The principal components of the scanner are a laser light source, a pair of horizontal and vertical scanning mirrors to deflect the laser light in these respective directions on the tissue surface, and a photo multiplier tube (PMT) detector. This paper characterizes the performance of the FSS for fluorescence imaging of tissues in vivo. First, a signal-to-noise ratio (SNR) analysis is presented. This is followed by characterization of the experimental SNR, linearity and spatial resolution of the FSS. Finally, the feasibility of tissue fluorescence imaging is demonstrated using an animal model. In summary, the performance of the FSS is comparable to that of fluorescence-imaging systems based on multipixel illumination and detection. The primary advantage of the FSS is the order-of-magnitude reduction in the cost of the light source and detector. However, the primary disadvantage of the FSS its significantly slower frame rate (1 Hz). In applications where high frame rates are not critical, the FSS will represent a low-cost alternative to multichannel fluorescence imaging-systems.
Prognostic Values of Tumor Necrosis Factor/Cachectin, Interleukin-l, Interferon- , and Interferon- in the Serum of Patients with Septic Shock (1990)

Serum concentrations of immunoreactive tumor necrosis factor/cachectin (TNF), interleukin-1 beta (IL-1 beta), interferon-gamma (IFN gamma), and interferon-alpha (IFN alpha) were prospectively measured in 70 patients with septic shock to determine their evolution and prognostic values. In a univariate analysis, levels of TNF (P = .002) and IL-1 beta (P = .05) were associated with the patient's outcome, but not IFN alpha (P = .15) and IFN gamma (P = .26). In contrast, in a stepwise logistic regression analysis, the severity of the underlying disease (P = .01), the age of the patient (P = .02), the documentation of infection (nonbacteremic infections vs. bacteremias, P = .03), the urine output (P = .04), and the arterial pH (P = .05) contributed more significantly to prediction of patient outcome than the serum levels of TNF (P = .07). After 10 days, the median concentration of TNF was undetectable (less than 100 pg/ml) in the survivors, whereas it remained elevated (305 pg/ml, P = .002) in the nonsurvivors. Thus, in patients with septic shock due to various gram-negative bacteria, other parameters than the absolute serum concentration of immunoreactive TNF contributed significantly to the prediction of outcome.
Matrix description of general motion correction applied to multishot images (2005)

Motion of an object degrades MR images, as the acquisition is time-dependent, and thus k-space is inconsistently sampled. This causes ghosts. Current motion correction methods make restrictive assumptions on the type of motions, for example, that it is a translation or rotation, and use special properties of k-space for these transformations. Such methods, however, cannot be generalized easily to nonrigid types of motions, and even rotations in multiple shots can be a problem. Here, a method is presented that can handle general nonrigid motion models. A general matrix equation gives the corrupted image from the ideal object. Thus, inversion of this system allows us to get the ideal image from the corrupted one. This inversion is possible by efficient methods mixing Fourier transforms with the conjugate gradient method. A faster but empirical inversion is discussed as well as methods to determine the motion. Simulated three-dimensional affine data and two-dimensional pulsation data and in vivo nonrigid data are used for demonstration. All examples are multishot images where the object moves between shots. The results indicate that it is now possible to correct for nonrigid types of motion that are representative of many types of patient motion, although computation times remain an issue.
Antinociception induced by civamide, an orally active capsaicin analogue (1997)

The antinociceptive effects of a novel capsaicin analogue, civamide (cis-8-methyl-N-vanillyl-6-nonenamide), given orally to adult rats were examined. In the formalin test, civamide significantly suppressed the flinch response, particularly phase 2, in a dose-dependent fashion (20-200 mg/kg). This inhibitory effect started 1 h after application, and was maintained for 4-7 days. A competitive capsaicin antagonist, capsazepine (15 mg/kg, s.c.), reversed the antinociceptive action of civamide (200 mg/kg) on the formalin test when it was given either 5 min or 55 min after oral civamide delivery. In contrast, capsazepine delivered 2 days after civamide had no effect upon the depressed formalin response. Civamide produced a significant increase in the response latency on the thermal paw withdrawal test, which persisted for 2-3 days. Civamide produced a modest, but statistically significant, reversal of low tactile thresholds otherwise observed in the Chung neuropathic rats. Morbidity (approximately 10%) was observed which was secondary to bronchial constriction occurring with gastric reflux. Civamide at the doses given did not produce motor dysfunction. Neither calcitonin gene-related peptide (CGRP) nor substance P (SP) concentrations in dorsal or ventral spinal cord were altered by civamide (200 mg/kg) up to 5 days, whereas CGRP, but not SP, in dorsal root ganglia (DRG) and sciatic nerves was modestly reduced at 1 day after the delivery. These data suggest that an orally bioavailable capsaicin analogue, civamide, possessed analgesic activity with respect to several noxious stimuli, including inflammation-induced hyperalgesia, noxious thermal stimulation and nerve injury-induced tactile allodynia. The rapid onset and lack of change in the peptide levels in dorsal spinal cord suggests that the analgesic action of civamide is primarily a result of desensitization at the afferent terminals. The antinociception of civamide is probably mediated by at least two mechanisms: (i) an acute receptor occupancy dependent effect; and (ii) a persistent and receptor independent effect which is initiated by the acute exposure to the drug.
Dorsoventral patterning in the Drosophila retina by wingless (1998)

The eye imaginal disc displays dorsal-ventral (D-V) and anterior-posterior polarity prior to the onset of differentiation, which initiates at the intersection of the D-V midline with the posterior margin. As the wave of differentiation progresses anteriorly, additional asymmetry develops as ommatidial clusters rotate coordinately in opposite directions in the dorsal and ventral halves of the disc; this forms a line of mirror-image symmetry, the equator, which coincides with the D-V midline of the disc. How D-V pattern is established and how it relates to ommatidial rotation are unknown. Here we address this question by assaying the expression of various asymmetric markers under conditions that lead to ectopic differentiation, such as removal of patched or wingless function. We find that D-V patterning develops gradually and that wingless plays an important role in setting up this pattern. We show that wingless is necessary and sufficient to induce dorsal expression of the gene mirror prior to the start of differentiation and also to restrict the expression of the WR122 marker to differentiating photoreceptors near the equator. In addition, we find that manipulations in wingless expression shift the D-V axis of the disc as evidenced by changes in the expression domains of asymmetric markers, the position of the site of initiation and the equator, and the pattern of epithelial growth. Thus, Wg appears to coordinately regulate multiple events related to D-V patterning in the developing retina.
The K65R Mutation Confers Increased DNA Polymerase Processivity to HIV-1 Reverse Transcriptase (1996)

The K65R mutation in HIV-1 reverse transcriptase (RT) is associated with viral cross-resistance to 2',3'-dideoxyinosine, 2',3'-dideoxycytidine, and 2',3'-dideoxy-3'-thiacytidine. We have found that in vitro DNA synthesis by K65R RT is significantly more processive than that of wild type (wt) RT. Depending on the template/primer (T/P) used, the total incorporation of nucleotides under single processive cycle conditions was 20-50% higher with K65R RT than with wt RT. With heteropolymeric T/P, the total incorporation of dNMP by K65R and wt RT was similar under continuous DNA synthesis reaction conditions. However, under single processive cycle conditions, the rate of full-length polymerization product synthesis by K65R RT was about 2-fold higher than that by wt RT. We also found a decreased rate of T/P dissociation during K65R RT DNA synthesis, which is consistent with the increased processivity of the enzyme. We postulate that the increased processivity of the K65R RT may be a compensatory response to the decreased affinity of this mutant for certain dNTP substrates, allowing normal viral replication kinetics.