gebhart/patrepeval huggingface dataset:
Pharmacodynamic Assessment of Cefprozil against <i>Streptococcus pneumoniae</i> : Implications for Breakpoint Determinations (2000)

Cefprozil, an oral semisynthetic cephalosporin, is commonly utilized in the treatment of respiratory-tract infections in children. While this agent has provided acceptable clinical success over a number of years, this study was undertaken to better define its pharmacodynamic profile against Streptococcus pneumoniae. Nineteen clinical isolates of S. pneumoniae were utilized in the neutropenic murine thigh infection model. To simulate the pharmacokinetic profile of cefprozil in children, the renal function of mice was impaired with uranyl nitrate, and a commercially available cefprozil suspension (6 mg/kg of body weight) was administered orally every 12 h. Mice were infected with 10(6) to 10(7) CFU per thigh, and therapy was initiated 2 h later. At 0 and 24 h postinfection, thighs were harvested to determine bacterial density. Survival was assessed during 96 h of therapy. The magnitude of bacterial kill ranged from 0.5 to 4.4 log(10) CFU per thigh over 24 h, and the extent of microbial eradication was dependent on the MIC. Killing of more than 2.6 log(10) CFU per thigh was observed with MICs of < or =3 microg/ml, while either minimal killing or growth was detected with MICs of > or =4 microg/ml. Mortality in untreated control animals was 100%. Animals infected with strains for which the MICs were < or =2 microg/ml survived the infection, whereas MICs exceeding 2 microg/ml resulted in substantial mortality. These studies demonstrate the effectiveness of cefprozil against isolates of the pneumococcus for which the MICs are < or =2 microg/ml using a drug exposure typically observed in children. These data support a susceptibility breakpoint of < or =2 microg/ml for cefprozil.
Conformational Changes, Plasma Membrane Penetration, and Infection by Human Rhinovirus Type 2: Role of Receptors and Low pH (2003)

Human rhinovirus type 2 (HRV2) is internalized by members of the low-density lipoprotein (LDL) receptor (LDLR) family. It then progresses into late endosomes, where it undergoes conversion from D- to C-antigenicity at pH < 5.6. Upon uncoating, the viral RNA is transferred into the cytoplasm across the endsosomal membrane. However, C-antigenic particles fail to attach to LDLR; this raised the question of whether the virus remains attached to the receptors and is carried to late compartments or rather falls off at the higher pH in early endosomes. We therefore determined the pH dependence of virus-receptor dissociation and virus conversion to C-antigen under conditions preventing endocytosis. (35)S-HRV2 was attached to HeLa cells at 4 degrees C and incubated in buffers of pH 7.4 to 5.0; levels of native virus and C-antigenic particles remaining cell associated or having been released into the medium were determined by immunoprecipitation. At pH 6.0, HRV2 was readily released from plasma membrane receptors in its native form, whereas at pH < or = 5.4, it was entirely converted to C-antigen, which, however, only dissociated from the surface upon prolonged incubation. The antigenic conversion occurred at the same pH regardless of whether HRV2 was free in solution or bound to its receptors. These data suggest that, in vivo, the virus is no longer bound to its receptors when the antigenic conversion and uncoating occur in more acidic late endosomes. When virus was bound to HeLa cells at 4 degrees C, converted into C-antigen by exposure to pH 5.3, and subsequently warmed to 34 degrees C in the presence of bafilomycin (to prevent endosomal uncoating), viral de novo synthesis was detected. This study demonstrates for the first time that a nonenveloped virus such as HRV2 can infect from the plasma membrane when artificially exposed to low pH. This implies that the viral RNA can gain access to the cytoplasm from the plasma membrane.
Microfluidic formulation of pectin microbeads for encapsulation and controlled release of nanoparticles (2011)

We report a method for formulation of pectin microbeads using microfluidics. The technique uses biocompatible ingredients and allows for controlled external gelation with hydrogen and calcium ions delivered from an organic phase of rapeseed oil. This method allows for encapsulation of nanoparticles into the microparticles of gel and for control of the rate of their release.
Identification of the Genes Encoding Mn<sup>2+</sup>-Dependent RNase HII and Mg<sup>2+</sup>-Dependent RNase HIII from <i>Bacillus subtilis</i>:  Classification of RNases H into Three Families (1998)

Database searches indicated that the genome of Bacillus subtilis contains three different genes encoding RNase H homologues. The ypdQ gene encodes an RNase HI homologue with 132 amino acid residues, whereas the rnh and ysgB genes encode RNase HII homologues with 255 and 313 amino acid residues, respectively. RNases HI and HII show no significant sequence similarity. These genes were individually expressed in Escherichia coli; the recombinant proteins were purified, and their enzymatic properties were compared with those of E. coli RNases HI and HII. We found that the ypdQ gene product showed no RNase H activity. The 2.2 kb pair genomic DNA containing this gene did not suppress the RNase H deficiency of an E. coli rnhA mutant, indicating that this gene product shows no RNase H activity in vivo as well. In contrast, the rnh (rnhB) gene product (RNase HII) showed a preference for Mn2+, as did E. coli RNase HII, whereas the ysgB (rnhC) gene product (RNase HIII) exhibited a Mg2+-dependent RNase H activity. Oligomeric substrates digested with these enzymes indicate similar recognition of these substrates by B. subtilis and E. coli RNases HII. Likewise, B. subtilis RNase HIII and E. coli RNase HI have generated similar products. These results suggest that B. subtilis RNases HII and HIII may be functionally similar to E. coli RNases HII and HI, respectively. We propose that Mn2+-dependent RNase HII is universally present in various organisms and Mg2+-dependent RNase HIII, which may have evolved from RNase HII, functions as a substitute for RNase HI.
Do Optimal Non-Renewable Resource Tariffs Suffer From Dynamic Inconsistency? (2000)

In this paper we have examined optimal tariffs for non-renewable natural resources in the setting of imperfect competition. We do this because Larry Karp (1984, p. 74) states that, "If the buyer attempts to exert market power, he is constrained by the dynamic optimization behavior of the seller and does not face a standard control problem." We show that when extraction costs are a function of the remaining stock of the resource, the costate variable can be separated into a scarcity effect and a cost effect. Karp concludes that the cost effect must be left with the producer; thereby, restricting the actions of the buyer. We, however, prove that it is not necessary to pay this cost effect to the producer; hence, we conclude that the monopsonist can extract all of the rent from the seller. The optimal tariff is neither dynamically time inconsistent, nor is it "Karp's consistent tariff."
ChemInform Abstract: ACTIVATED METALS, THE EFFECT OF ADDED METAL SALTS ON MAGNESIUM REACTIVITY (1974)

Abstract Magnesiumchlorid liefert mit Kalium und Kaliumjodid in siedendem Tetrahydrofuran ein schwarzes Magnesiumpulver, das mit p‐Chlortoluol die Grignard‐Verbindung (III) ergibt.
Direct tunneling diode structure with a multilayer charge injection barrier (1998)

We report the fabrication and testing of a silicon-based tunnel diode structure that incorporates a multilayer tunneling dielectric. The barrier consists of two thermally grown silicon oxide layers of direct tunneling thickness, ∼3.5 nm each, separated by an ultrathin nanocrystalline silicon layer approximately 5 nm thick. The diode displays current–voltage characteristics that are similar to those of a Fowler–Nordheim device, with a strong current turn-on beyond threshold positive and negative biases, and a “window” region between these two levels where charge transport across the barrier is negligible. In contrast to Fowler–Nordheim devices, the barrier does not appear to degrade significantly when biased in either of its conduction regimes. This property is attributed to the intrinsic degradation resistance of direct tunnel oxides. Additionally, capacitance–voltage characteristics show that the structure is of high quality. Because of its current–voltage and endurance capabilities, this structure shows promise for nonvolatile memory and other applications which require improved endurance and charge retention.
CIRCULAR, HEXAGONAL AND OCTAGONAL ARRAY GEOMETRIES FOR SMART ANTENNA SYSTEMS USING HYBRID CFO-HC ALGORITHM (2012)

In this paper, circular, hexagonal and Octagonal array geometries for smart antenna applications are compared. Uniform circular (UCA), uniform hexagonal (UHA) and uniform Octagonal arrays (UOA) with 24 half-wave dipole elements are examined. An efficient global hybrid optimization method is proposed combining the Central Force Optimization (CFO) as a global optimizer and Hillclimbing (HC) algorithm as a local optimizer. After the final global iteration, a local optimization can be followed to further improve the solution obtained from the CFO. The CFO-HC algorithm is used to optimize the complex excitations, amplitudes and phases, of the adaptive arrays elements for beamforming, the CFO-HC algorithm was implemented using MATLAB-software and linked to the CST simulator to simulate the adaptive arrays.
An Electronic Information Marketplace. (1985)

Abstract This paper presents a description of the Electronic Information Marketplace that has been implemented as a specialized subsystem on the Electronic Information Exchange System (EIES). This system allows any user of the EIES system to sell and barter information, services and items to other EIES members. The system is designed as a direct user-to-user marketplace and completely eliminates the need for a special class of “Information Providers” typical of other current approaches. The implications of the electronic marketplace are discussed in terms of individual and public use, industry structure, costs, cooperative computing and user expectations and impacts.
CRED: A Deep Residual Network of Convolutional and Recurrent Units for Earthquake Signal Detection (2019)

Earthquake signal detection is at the core of observational seismology. A good detection algorithm should be sensitive to small and weak events with a variety of waveform shapes, robust to background noise and non-earthquake signals, and efficient for processing large data volumes. Here, we introduce the Cnn-Rnn Earthquake Detector (CRED), a detector based on deep neural networks. CRED uses a combination of convolutional layers and bi-directional long-short-term memory units in a residual structure. It learns the time-frequency characteristics of the dominant phases in an earthquake signal from three component data recorded on individual stations. We train the network using 500,000 seismograms (250k associated with tectonic earthquakes and 250k identified as noise) recorded in Northern California. The robustness of the trained model with respect to the noise level and non-earthquake signals is shown by applying it to a set of semi-synthetic signals. We also apply the model to one month of continuous data recorded at Central Arkansas to demonstrate its efficiency, generalization, and sensitivity. Our model is able to detect more than 800 microearthquakes as small as -1.3 ML induced during hydraulic fracturing far away than the training region. We compare the performance of the model with the STA/LTA, template matching, and FAST algorithms. Our results indicate an efficient and reliable performance of CRED. This framework holds great promise for lowering the detection threshold while minimizing false positive detection rates.
Grandmothers as Gems of Genetic Wisdom: Exploring South African Traditional Beliefs About the Causes of Childhood Genetic Disorders (2009)

With its diverse cultural and linguistic profile, South Africa provides a unique context to explore contextual influences on the process of genetic counseling. Prior research suggests intergenerational differences regarding models of causation which influence treatment-seeking paths. This pilot study therefore aimed to explore South African traditional beliefs regarding common childhood genetic disorders. Three focus groups were conducted with fifteen grandmothers from different cultural backgrounds in an urban community. Questions pertained to the role of the grandmother, traditional beliefs regarding causes of genetic disorders, explanations of heredity, and prevention and management of genetic disorders. Results indicate a variety of cultural explanations for causes of childhood genetic disorders. These causes can be classified into categories related to lifestyle, behavior, social issues, culture, religion, genetic, and familial causes. Prevention and treatment issues are also highlighted. These findings have implications for genetic counseling practice, which needs to include a greater focus on cultural issues.
The Biotransformation of Propylene to Propylene Oxide by<i>Methylococcus Capsulatus</i>(Bath): 1. Optimization of Rates (1992)

The rates of propylene oxidation to propylene oxide by Methylococcus capsulatus (Bath) have been optimized in small shake flasks to establish the potential of this process for industrial application. It was shown that addition of the electron donors methanol, formaldehyde, formate or hydrogen stimulated the endogenous rate of propylene oxide formation 10 to 50 fold. Rates in excess of 500 nmol min-1 mg dry weight cells-1 have been obtained using methanol as the donor. These high rates could only be sustained for 3 to 4 min before loss of biocatalytic activity caused the rate of propylene oxide production to decline.
Rapid Generation and Control of Microporosity, Bimodal Pore Size Distribution, and Surface Area in Davankov-Type Hyper-Cross-Linked Resins (2005)

Synthesis of Davankov-type hyper-cross-linked resin beads has been carried out using gel-type and permanently porous poly(divinylbenzene-co-vinylbenzyl chloride) (DVB−VBC) precursor resins without any external electrophile. Of the Lewis acids examined (FeCl3, AlCl3, SnCl4), FeCl3 was by far the most effective catalyst. Rather remarkably in the case of a gel-type 2 mol % DVB−VBC precursor, extensive microporosity was generated within only 15 min of initiating the cross-linking reaction, yielding a surface area (N2 sorption/BET) of ∼1200 m2 g-1, which rose steadily to a maximum approaching 2000 m2 g-1 after 18 h. In the case of porous DVB−VBC precursor resins, the presence of discrete pores in the precursor, accompanied by a micropore fraction on hyper-cross-linking, yields resins with a clearly bimodal distribution of pores. Manipulation of the Friedel−Crafts reaction variables and the structure of the precursor resin allows final resin products to be prepared with surface areas in the range ∼300−2000 m2 g-1.
Writing on wet paper (2005)

In this paper, we show that the communication channel known as writing in memory with defective cells is a relevant information-theoretical model for a specific case of passive warden steganography when the sender embeds a secret message into a subset C of the cover object X without sharing C with the recipient. The set C, which is also called the selection channel, could be arbitrary, determined by the sender from the cover object using a deterministic, pseudo-random, or a truly random process. We call this steganography "writing on wet paper" and realize it using a simple variable-rate random linear code that gives the sender a convenient flexibility and control over the embedding process and is thus suitable for practical implementation. The importance of the wet paper scenario for covert communication is discussed within the context of adaptive steganography and perturbed quantization steganography. Heuristic arguments supported by tests using blind steganalysis indicate that the wet paper steganography provides improved steganographic security and is less vulnerable to steganalytic attacks compared with existing methods with shared selection channels.
Observation of phononic helical edge states in a mechanical topological insulator (2015)

A topological insulator, as originally proposed for electrons governed by quantum mechanics, is characterized by a dichotomy between the interior and the edge of a finite system: The bulk has an energy gap, and the edges sustain excitations traversing this gap. However, it has remained an open question whether the same physics can be observed for systems obeying Newton's equations of motion. We conducted experiments to characterize the collective behavior of mechanical oscillators exhibiting the phenomenology of the quantum spin Hall effect. The phononic edge modes are shown to be helical, and we demonstrate their topological protection via the stability of the edge states against imperfections. Our results may enable the design of topological acoustic metamaterials that can capitalize on the stability of the surface phonons as reliable wave guides.
The platelet-activating factor acetylhydrolase from human erythrocytes. Purification and properties. (1993)

Platelet-activating factor (PAF, 1-O-alkyl-2-acetyl-sn-glycero-3- phosphocholine) is a biologically active phospholipid. Tissues, blood cells, and plasma contain PAF acetylhydrolases (calcium independent phospholipase A2 activities) that catalyze the hydrolysis of phospholipids containing short chain sn-2 acyl groups. They inactivate PAF and thereby determine PAF accumulation. We purified the PAF acetylhydrolase from human erythrocytes 15,600-fold. The enzyme has a molecular weight of 25,000, it behaves as a dimer during gel filtration, and it is a previously uncharacterized cytosolic esterase, as it has a unique amino-terminal sequence. The erythrocyte PAF acetylhydrolase requires the addition of sulfhydryl agents for maximal activity, is inhibited by 5,5'-dithiobis(2-nitrobenzoic acid), NaF, diisopropyl fluorophosphate, diethylpyrocarbonate, p-bromophenacylbromide, and a number of proteases. Antibodies against the purified protein precipitate all PAF hydrolase activity from erythrocyte lysates. The erythrocyte PAF acetylhydrolase is specific for short or oxidized sn-2 acyl residues. It exhibits surface dilution kinetics, suggesting that hydrolysis occurs at lipid interfaces. This suggests that this enzyme acts in vivo as a scavenger of oxidatively fragmented phospholipids that are toxic to the cell.
An Overview of Endophytic Microbes: Endophytism Defined (2000)

To microbes, land plants present a complex, spatially and temporally diverse ecological habitat. Symbiotic associations between microorganisms and plants are ancient and fundamental, and many examples of complex and highly specific symbioses between plants and microbes have been described in detail. Endophytic microbes are an intriguing group of organisms associated with various tissues and organs of terrestrial and some aquatic plants, and are the subject of increasing interest to mycologists, ecologists, and plant pathologists. In general, "endophytic" infections are inconspicuous, the infected host tissues are at least transiently symptomless, and the microbial colonization can be demonstrated to be internal, either through histological means, by isolation from strongly surface disinfected tissue, or, most recently, through direct amplification of fungal nuclear DNA from colonized plant tissue. Infections of land plants by endophytes are ubiquitous, having been found throughout a broad range of host orders, families, and genera worldwide, and representing a diverse array of terrestrial and aquatic habitats.
SEMICONDUCTOR QUANTUM DOT LASERS (2000)

The history of semiconductor laser diodes,and especially quantum dot(QD) lasers with their superior lasing characteristics,are briefly reviewed.Typical techniques for fabricating semiconductor QDs and three\|dimensional QD arrays are described.Various ideas for the band energy structure design and the conditions for realizing lasing via the ground states of QD lasers are presented,and recent exciting research advances are summarized in detail.Finally,the key problems for improving the properties of QD lasers,future trends and prospects for this new type of laser diode are discussed.
RADIOIMMUNOASSAY FOR HUMAN GROWTH HORMONE USING MONOCLONAL ANTIBODIES (1980)

Radioimmunoassay (RIA's) for human growth hormone (hGH) employing monoclonal antibodies (Mab) were compared with a conventional clinical RIA using polyclonal antibodies (PAb). Several MAb displayed sensitivities (defined as the concentration of hormone required for 50% inhibition of binding of 125I-hGH) for hGH in the RIA which were equivalent to those of PAb. Those MAb with the greatest sensitivity for hGH displayed an equal affinity for human placental lactogen (hPL), whereas those with lower sensitivity for hGH, cross-reacted minimally with hPL. The concentrations of hGH in human serum samples were determined with MAb and the values showed a high degree of correlation with those obtained by PAb. It is therefore concluded that MAb are useful for the development of clinical RIA's for polypeptide hormones.
Correlation of the virulence of Klebsiella pneumoniae K1 and K2 with the presence of a plasmid encoding aerobactin (1986)

Nine isolates of Klebsiella pneumoniae belonging to capsular serotypes K1 and K2 were assayed for virulence in mice. Virulent isolates (50% lethal dose of less than 10(3) microorganisms) and avirulent isolates (50% lethal dose of over 10(6) microorganisms) were selected. Supplementation of a defined minimal medium with transferrin markedly reduced the growth of avirulent strains but had no significant effect on the growth of virulent strains. All isolates produced enterochelin, but only production of aerobactin could be correlated with virulence. The genes encoding aerobactin and its receptor protein were located on a 180-kilobase plasmid. They were cloned into the mobilizable vector pSUP202. Homology was demonstrated with the aerobactin operon of the Escherichia coli plasmid pColV-K30. Transfer of the recombinant plasmid pKP4 into an avirulent recipient enhanced virulence by 100-fold. These experiments demonstrated that aerobactin is an essential factor of pathogenicity in K. pneumoniae.
Role of Human Hepatocyte Nuclear Factor 4α in the Expression of Drug-Metabolizing Enzymes and Transporters in Human Hepatocytes Assessed by Use of Small Interfering RNA (2007)

Hepatocyte nuclear factor 4alpha (HNF4alpha) is an important transcription factor in hepatic gene expression. Here, we have investigated the role of HNF4alpha in the expression of drug-metabolizing enzymes and transporters in human hepatocytes using an adenovirus expressing human HNF4alpha-small interfering RNA (hHNF4alpha-siRNA). The hHNF4alpha-siRNA effectively reduced the mRNA and nuclear protein levels of hHNF4alpha in a concentration-dependent manner. The hHNF4alpha-siRNA also decreased the mRNA levels of CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP3A4, UGT1A1, UGT1A9, SULT2A1, ABCB1, ABCB11, ABCC2, OATP1B1 and OCT1, as well as those of PXR and CAR. To discern the role of these nuclear receptors, we co-infected hepatocytes with hHNF4alpha-siRNA and PXR- or CAR-expressing adenovirus. The hHNF4alpha-siRNA-induced reductions of the enzyme and transporter mRNA levels were not restored except CYP2B6 mRNA levels, which were returned to the control level by overexpressing CAR. Furthermore, although hHNF4alpha-siRNA did not significantly affect the fold-induction of CYP2B6, CYP2C8, CYP2C9, or CYP3A4 mRNA levels following treatment with CYP inducers, the levels in hHNF4alpha-suppressed cells fell significantly compared to the control. These results suggest that HNF4alpha plays a dominant role in the expression of drug-metabolizing enzymes and transporters in human hepatocytes, and that HNF4alpha expression levels is a possible determinant for inter-individual variations in the expression of these enzymes and transporters.