gebhart/patrepeval huggingface dataset:
Synthesis of Pyrolysis Products of Bisdehydrodihydroenmein : I. Synthesis of 6-Hydroxy-7-methylphthalide and 2-Hydroxymethyl-6, 6-dimethyl-5-oxo-1-cyclohexenecarboxylic Acid Lactone (1968)

In the course of an investigation on the structure of enmein (I), isolated from Isodon trichocarpus, five well-characterized products (IV-VIII) were obtained by pyrolysis of bisdehydrodihydroenmein (II). In the present paper, synthesis of two (V and VI) of those compounds which obviously originated from ring A of compound (II) is reported. The former compound, 6-hydroxy-7-methylphthalide (V), was prepared in the following way. Chloromethylation of m-methoxybenzoic acid under the forcing conditions gave a mixture of compounds consisting of X, XI, and XII which were separated by fractional crystallization. Hydrogenation of XI followed by treatment with hydriodic acid yielded V, identical with one of the pyrolysis products mentioned above. The latter compound (VI) was synthesized by two alternative methods. First, compound (XXII) was treated with thionyl chloride to give XXIII which was then subjected to bromination, followed by sodium borohydride reduction, giving XXXI. The resulting XXXI was subsequently dehydrobrominated to give XXXII, which on oxidation, followed by C-methylation, gave a compound which was identical with VI. The other method used to produce VI involves first the addition of dimethyl acetylenedicarboxylate to butadiene. The resulting diester (XLVII) was converted to the anhydride (XLVIII) and then reduced with lithium aluminum hydride, giving XLIX. Treatment of this with NBS yielded LII which was debrominated by treatment with Raney Ni. The resulting hydroxy-lactone (LIII) was oxidized and then C-dimethylated to yield VI.
Sources of Pathogenic Microorganisms and Their Fate during Land Application of Wastes (2005)

Phosphorus (P) has been identified as the key constituent defining wetland productivity, structure, and function. Our goal was to investigate the spatial patterns of total P and three labile forms of P (labile organic, inorganic, and microbial biomass P) across a subtropical wetland located in east-central Florida, the Blue Cypress Marsh Conservation Area (BCMCA), and link spatial patterns to ecosystem processes. The wetland received a continual input of nutrients primarily from the south and intermittently from the west and east, respectively, which ceased in the mid-1990s. Since then the marsh system has been undergoing natural succession. We used (i) ordinary kriging to characterize the spatial patterns of total P and labile P forms across the wetland, (ii) local, moving spatial correlations to investigate relationships between total P and labile P forms, and (iii) a clustering technique to link the identified spatial patterns to biogeochemical processes. The spatially explicit analyses revealed patterns of total P and labile P forms as well as changing relationships between variables across the marsh. We were able to distinguish P-enriched areas from unaffected ("natural") areas and intermediate zones that are currently undergoing change as P is mobilized and translocated. We also identified areas that are at risk, showing a shift toward a more P-enriched status. Our results improve our understanding of P and its labile components within a spatially explicit context.
<title>Predicting electronic component lifetime using thermography</title> (1991)

The concept of using IR imaging technology in locating failures in populated and unpopulated printed circuit boards (PCB) has been around since the mid 70's. However, the use of IR imaging technology in predicting component failure has been almost nonexistent. An IR workstation was developed to identify components that had become degraded as a result of aging, stress, or 'wear and tear'. Unlike previous work in IR diagnostic which uses a 'gold' image for comparison, the image history is developed on an individual board basis. The boards were subjected to both thermal and voltage stress to induce component degradation and failure. Preliminary results indicate that some components show a consisted thermal profile that may be used in predicating the lifetime of some components; other components exhibit no consisted thermal pattern change. Due to the varying statistical nature of stress to PCB modules during use in the field and the complexity of designing thermal simulations for each type of PCB module, designing a low cost IR workstation to predict component lifetime is not practical. However, a related application of the effort offers the means to significantly enhance the reliability of PCB modules which have large populations.
Low-Noise Microwave and Optical Waveform Synthesis with Femtosecond Laser Frequency Combs (2007)

Low-noise 10 GHz signals are generated from a reference laser whose frequency is divided down by a factor of ~5-10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sup> with a femtosecond laser optical frequency comb. Recent results, including extensions toward synthesis of complex microwave and optical waveforms will be discussed.
A classification tree-based system for multi-sensor train approach detection (2015)

Personnel safety is an integral element of any railroad operation. Rail tracks need to be regularly maintained, which often requires rail workers to be physically present on possibly live tracks along with their equipment. This results in hazardous work conditions for the workers. To ensure worker safety a reliable system for detecting oncoming trains and alerting the workers, while giving them sufficient time to disengage from the worksite, is essential. In this paper, we present a multiple sensor based system that integrates the sensor elements with a signal processing unit for this purpose. The processing unit consists of a signal conditioning unit, a data processing unit and a machine learning framework. The conditioning unit prepares the acquired signals for later operations. The data processing unit extracts fingerprints from the reported signals that are later used by the machine learning framework as training and testing samples. The machine framework is a binary tree that classifies the event under investigation as presence or absence of a train on the track under observation. We show that the system is very accurate and can alert the workers under five seconds after the arrival of the train at the test site.
Thiourea-Catalyzed Enantioselective Iso-Pictet–Spengler Reactions (2011)

A one-pot condensation of isotryptamines and aldehydes that affords enantiomerically enriched 4-substituted tetrahydro-γ-carbolines is reported. The reaction is induced by a chiral thiourea/benzoic acid dual catalyst system. Purification of the N-Boc-protected products by trituration or crystallization provides the optically pure tetrahydro-γ-carboline derivatives in a scalable and highly practical procedure.
Over‐expression of CCL3  MIP‐1α in a blastoid mantle cell lymphoma with hypercalcemia (2009)

We analyzed a case with the blastoid variant of mantle cell lymphoma (MCL-BV), a rare subtype of B-cell lymphoma, presenting with marked hypercalcemia at diagnosis. Enzyme-linked immunosorbent assay (ELISA) showed elevated serum levels of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), macrophage inflammatory protein-1alpha (MIP-1alpha), and type I collagen telopeptide, but not parathyroid hormone, calcitriol or parathyroid hormone-related peptide at diagnosis, suggesting local osteoclastic hypercalcemia in this case. By reverse transcription polymerase chain reaction (RT-PCR) analysis, we found predominant expression of mRNA for MIP-1alpha in addition to those for receptor-activator of nuclear-factor kappa B ligand (RANKL), TNF-alpha, and IL-6 in lymphoma cells obtained from the patient. Furthermore, recombinant MIP-1alpha significantly stimulated (3)H-thymidine uptake by isolated MCL cells in vitro. Treatment with intravenous fluids, bisphosphonate, and methylprednisolone followed by combination chemotherapy promptly corrects the hypercalcemia and successfully induced complete remission, which was accompanied by a decrease of these cytokines in the serum, including MIP-1alpha. In the present case, MIP-1alpha, an osteoclast-activating factor produced by mantle lymphoma cells, may contribute to the development of hypercalcemia. It likely acts through RANKL expression in tumor cells and/or stroma cells, as indicated in multiple myeloma (MM) and adult T-cell leukemia/lymphoma (ATLL). Furthermore, MIP-1alpha is also involved in the development of an aggressive phenotype on MCL by stimulating proliferation of these lymphoma cells. In summary, the present study demonstrated that MIP-1alpha is an important factor in the development of both hypercalcemia and an aggressive phenotype in some types of B-cell lymphoma.
Changes in the Secondary Structure of Adsorbed IgG and F(ab‘)<sub>2</sub> Studied by FTIR Spectroscopy (1996)

The purpose of the present study is to find a quantitative relationship between the adsorption behavior and the secondary structure of proteins. The adsorption of two monoclonal IgGs which differ in their isoelectric point and their corresponding F(ab‘)2 fragments is followed in time. The proteins are adsorbed on hydrophilic silica and on hydrophobic methylated surfaces at different values of pH and ionic strength. The adsorption behavior is studied by measuring FTIR spectra of the adsorbed proteins. The adsorbed amount is related to the integrated area of the amide II region of the spectrum. The secondary structure of the adsorbed proteins is evaluated by analyzing the second derivatives of the amide I region. Quantitative information on the secondary structure is obtained by applying a fitting procedure which assumes the absorption bands for the different structural components to be Lorentzian shaped. The results show that for IgG the adsorbed amounts decrease with an increasing net charge density on the protein. This decrease is correlated to a reduction in the β-sheet content which suggests that IgG molecules adsorb in a less compact conformation. The adsorption-induced reduction in the β-sheet content is larger at hydrophobic methylated surfaces than at hydrophilic silica surfaces. The dependence of the amount of structural elements on the pH diminishes at higher ionic strength. F(ab‘)2 fragments contain a higher fraction of β-sheet content than whole IgG molecules, and these fractions are less strongly influenced by the adsorption conditions. Therefore, it can be concluded that the F(ab‘)2 fragments have a higher structural stability toward adsorption than whole IgG molecules.
A unity power factor multiple isolated outputs switching mode power supply using a single switch (2002)

The authors present an offline switching power supply with multiple isolated outputs and unity power factor with the use of only one power processing stage, based on the DC-DC SEPIC (single ended primary inductance converter) modulated by variable hysteresis current control. The principle of operation, the theoretical analysis, the design procedure, an example, and simulation results are presented. A laboratory prototype, rated at 160 W, operating at a maximum switching frequency of 100 kHz, with isolated outputs rated at +5 V/15 A, -5 V/1 A, +12 V/6 A and -12 V/1 A, has been built given an input power factor near unity.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Amino-acids and peptides. Part XXVIII. Anchimeric acceleration of the aminolysis of esters. The use of mono-esters of catechol in peptide synthesis (1968)

The hypothesis that the aminolysis of esters can be accelerated by a neighbouring group capable of hydrogen-bonding to the incoming amine and accepting a proton from it has been supported by further evidence. Since such acceleration is not available for oxazolone formation (in which the nucleophile bears no hydrogen) it becomes possible to design fast, racemisation-free methods of peptide synthesis. Phthaloylglycine o-hydroxyphenyl and 4,5-dichloro-2-hydroxyphenyl esters, and benzoyl-L-leucine o-hydroxyphenyl ester, couple rapidly with glycine ethyl ester at room temperature; in the last case (a standard racemisation test) no racemate was found, and with triethylamine the ester gave no oxazolone. When the neighbouring hydroxy-group was protected as the benzyl ether, an unreactive intermediate was obtained which could be activated at will by removal of the benzyl group, by catalytic hydrogenation or by the action of hydrogen bromide in acetic acid.
An Assay of <i>Staphylococcus Epidermidis</i> Biofilm Responses to Therapeutic Agents (1993)

Implant-associated infections tend to become persistent, resisting host defences and antibiotic therapy. Routine clinical laboratory testing of bacterial isolates in the fluid phase for antibiotic susceptibility may not be predictive of therapeutic outcomes and therefore a number of antibiotic regimes have been formulated empirically. The resistance of implant-associated infections has been ascribed to the production by bacteria, when adherent to the implant surface, of a shielding matrix of polymerized carbohydrates protecting the enclosed bacteria from immune defences and antibiotics. This complex of surface, bacteria and matrix is termed a biofilm. We describe a technique to evaluate the efficacy of antimicrobial agents directed against biofilm-forming strains of Staphylococcus epidermidis (a major cause of implant infections) utilizing standardized biofilm preparations formed on glass. The impact of the antimicrobial agents was assessed quantally using the end-point of permanent cessation of metabolic activity (cell death) of the entire biofilm determined by the loss of ability to reduce 2,3,5-triphenyltetrazolium chloride to a visible red intracellular precipitate of formazan. The relative rate of action of differing antimicrobial agents could be determined by the minimum period of exposure of the biofilm to the agents that is required to bring about sterilization, the clinically relevant marker. A wide range of antimicrobial substances could be evaluated, including chemical disinfectants, immunoreactive substances, antibiotics; singly and in combination; and the modifying effects of interaction with non-antibacterial therapeutic agents and other environmental factors. The technique is simple, inexpensive, reproducible and readily adaptable to the clinical situation where evaluation of therapeutic regimes for individual cases of prosthetic device-associated infection is required routinely with despatch and ease of interpretation.
Parallel MRI reconstruction using variance partitioning regularization (2007)

Multiple receivers can be utilized to enhance the spatiotemporal resolution of MRI by employing the parallel imaging technique. Previously, we have reported the L-curve Tikhonov regularization technique to mitigate noise amplification resulting from the geometrical correlations between channels in a coil array. Nevertheless, one major disadvantage of regularized image reconstruction is lengthy computational time in regularization parameter estimation. At a fixed noise level, L-curve regularization parameter estimation was also found not to be robust across repetitive measurements, particularly for low signal-to-noise ratio (SNR) acquisitions. Here we report a computationally efficient and robust method to estimate the regularization parameter by partitioning the variance of the noise-whitened encoding matrix based on the estimated SNR of the aliased pixel set in parallel MRI data. The proposed Variance Partitioning Regularization (VPR) method can improve computational efficiency by 2-5-fold, depending on image matrix sizes and acceleration rates. Our anatomical and functional MRI results show that the VPR method can be applied to both static and dynamic MRI experiments to suppress noise amplification in parallel MRI reconstructions for improved image quality.
Immunological Properties of <i>Rickettsia rickettsii</i> Purified by Zonal Centrifugation (1975)

The properties of Rickettsia rickettsii purified from infected chicken yolk sacs or mouse L cell cultures by sucrose density gradient centrifugation in a zonal rotor were examined in various ways. Rickettsiae derived from both L cells and yolk sacs had similar compositions: about 12% nitrogen, 1.5% phosphorus, 5% carbohydrate, and 30% fatty acids. On a dry-weight basis, purified rickettsiae were at least 2,000 times as effective as a commercial spotted fever vaccine in protecting guinea pigs against infection with spotted fever rickettsiae and mice against death from toxin of R. rickettsii. Gradient-purified rickettsiae (0.6 mug) induced a serological response in guinea pigs of the same magnitude as that stimulated by 1,600 mug of the commercial vaccine. Gradient-purified rickettsiae had little group reactivity in complement fixation tests but became anti-complementary upon storage. Microagglutination and hemagglutination tests with the purified antigen gave promise of usefulness in diagnosis of spotted fever. These results suggest that zonal centrifugation may be a valuable procedure for the preparation of R. rickettsii vaccine and diagnostic reagent.
Single cell transcriptional profiling reveals heterogeneity of human induced pluripotent stem cells (2011)

Human induced pluripotent stem cells (hiPSCs) and human embryonic stem cells (hESCs) are promising candidate cell sources for regenerative medicine. However, despite the common ability of hiPSCs and hESCs to differentiate into all 3 germ layers, their functional equivalence at the single cell level remains to be demonstrated. Moreover, single cell heterogeneity amongst stem cell populations may underlie important cell fate decisions. Here, we used single cell analysis to resolve the gene expression profiles of 362 hiPSCs and hESCs for an array of 42 genes that characterize the pluripotent and differentiated states. Comparison between single hESCs and single hiPSCs revealed markedly more heterogeneity in gene expression levels in the hiPSCs, suggesting that hiPSCs occupy an alternate, less stable pluripotent state. hiPSCs also displayed slower growth kinetics and impaired directed differentiation as compared with hESCs. Our results suggest that caution should be exercised before assuming that hiPSCs occupy a pluripotent state equivalent to that of hESCs, particularly when producing differentiated cells for regenerative medicine aims.
The cobalamin precursor cobinamide detoxifies nitroprusside-generated cyanide. (2007)

Sodium nitroprusside is used to treat hypertensive emergencies and acute heart failure. It acts by releasing nitric oxide (NO), a highly potent vasodilator, but unfortunately, for each NO molecule released, five cyanide ions are released. Thus, nitroprusside therapy is limited by cyanide toxicity. Therefore, a cyanide scavenger could be beneficial when administering nitroprusside. Hydroxocobalamin, which has a relatively high binding affinity for cyanide, has been shown to reduce cyanide levels in nitroprusside-treated patients. Cobinamide, the penultimate precursor in hydroxocobalamin biosynthesis, has a much greater affinity for cyanide than cobalamin, and binds two cyanide ions. We now show that cobinamide is highly effective in neutralizing cyanide ions released by nitroprusside in cultured mammalian cells, Drosophila melanogaster, and mice. Cobinamide also binds NO, but at molar concentrations 2.5-5 times that of nitroprusside, it did not decrease NO concentrations or the physiological effectiveness of nitroprusside. We conclude that cobinamide could be a valuable adjunct to nitroprusside therapy.
Langmuir flow effects in the laser gyro (1968)

Langmuir flow effects have been investigated in the laser gyro by measuring the integral of the beat frequency while tuning the frequency of oscillation. The results are in agreement with the traveling-wave Lamb model. The presence of the dc discharge tube walls gives rise to gas circulation in the laser gyro cavity. If the oppositely directed traveling waves see a net gas flow the gyro exhibits a null shift which depends on the magnitude and direction of the discharge current unbalance causing the net gas flow. The null shift is shown to be due to the mode pulling and pushing associated with the anomalous dispersion exhibited by the gain atoms.
Functional group dependence of the acid catalyzed ring opening of biomass derived furan rings: an experimental and theoretical study (2012)

We describe studies of Brønsted acid catalyzed ring opening of substituted furans contained within biomass derived C8- and C9-molecules. Ring opening occurs homogeneously under relatively mild conditions of 80 °C using catalytic hydrochloric acid. In the case of 4-(5-methyl-2-furyl)-2-butanone (1a), the reaction proceeds to a single product in up to 92% yield after 24 hours. For 4-(2-furanyl)-2-butanone (1b) and 4-(5-hydroxymethyl)-2-furanyl-2-butanone (1c), however, multiple products are observed, illustrating the significant influence of furan ring substituents on the reactivity of this class of compounds. The generality of these reaction pathways was tested using several other similar substrates. Kinetics experiments indicate that ring opening of 1a occurs via specific acid catalysis, and computations elucidate the effect of initial protonation on the reaction pathway. Calculated pKa values were calibrated against experimentally measured values and are consistent with observed reactivities. Inclusion of explicit, hydrogen-bonded water molecules in addition to the SMD solvent model is necessary when studying protonation of alcohol and ketone groups.
Biodistribution, Stability, and Antiviral Efficacy of Liposome–Entrapped Phosphorothioate Antisense Oligodeoxynucleotides in Ducks for the Treatment of Chronic Duck Hepatitis B Virus Infection (1998)

This study investigated the feasibility of using liposomes to increase the hepatic delivery and antiviral efficacy of phosphorothioate antisense oligodeoxynucleotides (PS-ODN) for the in vivo treatment of hepatitis B virus (HBV) infection. Ducks infected with duck hepatitis B virus (DHBV) were used as the model. We studied the stability of an antisense PS-ODN in duck plasma, its integrity during the process of liposome entrapment, its in vivo biodistribution, plasma clearance, and excretion. In addition, the intrahepatic distribution of a labeled free and liposome-entrapped ODN was also investigated. The results of our studies show that: 1) phosphorothioate ODN remain stable during the process of liposome entrapment; 2) are stable in duck plasma for many hours; 3) are rapidly cleared from the plasma when injected intravenously; 4) intravenous injection of antisense ODNs entrapped within liposomes enhances delivery of the ODN to the liver; and 5) inhibit DHBV replication. Serum DHBV DNA levels fell rapidly, with a corresponding decrease in intrahepatic viral replicative intermediates at the end of the 5-day study period. Although inhibition of viral replication and a fall in the target protein was observed, a marked inhibition of viral replication was also observed with high doses of a random-sequence ODN. Thus, it is not certain that inhibition of viral replication was entirely through an antisense mechanism. Therefore, liposomes may be effective vehicles to improve the delivery of antisense oligonucleotides to the liver for the therapy of hepatotropic viruses.