gebhart/patrepeval huggingface dataset:
Prebiotics and Iron Bioavailability—Is There a Connection? (2005)

ABSTRACT: Poor bioavailability of dietary iron, especially from diets rich in cereals and legumes, is a major factor contributing to the high prevalence of nutritional iron deficiency in developing countries. Dietary modification to increase intake of components that promote iron absorption from low‐bioavailability meals is an effective strategy for combating nutritional iron deficiency. Prebiotics are nondigestible oligosaccharides that selectively stimulate the growth and activity of specific species of bacteria in the colon with benefits to human health. Common prebiotics such as inulin and fructooligosaccharides occur naturally in a wide variety of plant‐based foods and have recently been suggested to have an enhancing effect on iron absorption. The hypothesis that prebiotics enhance iron absorption is biologically plausible because fermentation of prebiotics by natural microflora present in the colon may decrease the pH of the luminal content, promote reduction of Fe(III) to Fe(II), stimulate proliferation of epithelial cells to expand the absorptive surface area, and potentially stimulate expression of mineral‐transport proteins in epithelial cells. However, data available in the literature characterizing the enhancing properties of prebiotics on iron absorption are inconsistent, and mechanisms of actions involved are poorly understood. The notion that the colon can function as a significant site of iron absorption in response to stimulation by prebiotics, and the effect of long‐term exposure to prebiotics on the iron status of iron‐deficient subjects remain to be clarified. This review discusses the functional properties of prebiotics as a promising dietary factor that enhances iron absorption. Keywords: prebiotics, iron, colon, oligosaccharides, inulin
Multichannel ultrathin silicon-on-sapphire optical interconnects (2003)

Multichannel optical interconnects were developed using vertical-cavity surface-emitting laser (VCSEL) arrays and metal-semiconductor-metal photodetector (PD) arrays and driven by complementary metal-oxide-semiconductor circuits that were fabricated using ultrathin silicon-on-sapphire (SOS) technology. Low-threshold oxide-confined top-emitting VCSEL 8×8 arrays were designed and fabricated with off-site contact bonding pads. The arrays were flip-chip bonded to driver arrays on sapphire substrates and mounted on high-speed printed-circuit boards as optical transmitter arrays. The laser output was transmitted through the transparent sapphire substrate and coupled to MSM PD arrays and the SOS receiver. This optical interconnect system was demonstrated to operate at a data rate of 1.0 Gb/s per channel with a power consumption of 28 mW for each channel including transmitter and receiver.
Direct Synthesis of Gallium Oxide Tubes, Nanowires, and Nanopaintbrushes (2002)

We demonstrate bulk synthesis of highly crystalline beta-gallium oxide tubes, nanowires, and nanopaintbrushes using molten gallium and microwave plasma containing a mixture of monatomic oxygen and hydrogen. Gallium oxide nanowires were 20-100 nm thick and tens to hundreds of micrometers long. Transmission electron microscopy (TEM) revealed the nanowires to be highly crystalline and devoid of any structural defects. Results showed that multiple nucleation and growth of gallium oxide nanostructures could easily occur directly out of molten gallium exposed to an appropriate composition of hydrogen and oxygen in the gas phase. These gallium oxide nanostructures should be of particular interest for optoelectronic devices and catalytic applications.
Very large magnetoresistance in electrodeposited single-crystal Bi thin films (invited) (2000)

Single-crystal bismuth thin films, fabricated by electrodeposition and suitable annealing, exhibit very large magnetoresistance of 400 000% at 5 K and 300% at 300 K, as well as pronounced Shubnikov–de Haas oscillations. A hybrid structure demonstrates the potential for field sensing with sensitivities of 35%/Oe at 5 K and 0.2%/Oe at 300 K.
Recycling Process for Sinter-Active U<sub>3</sub>O<sub>8</sub>Powders (2010)

The effect of the oxidation temperature of UO2 pellets on the powder properties of oxidized U3O8 powders has been investigated. The powder morphology, crystalline size, and BET surface area of recycled U3O8 could be modified by controlling the oxidation temperature of the UO2 pellets. Recycled U3O8 powder with a high BET surface area and a small particle size could be obtained by lowering the oxidation temperature. It was also found that this low-temperature-oxidized sinter-active U3O8 powder is effective in mitigating the density drop of the UO2 pellets when the recycled U3O8 powder is added. Moreover, the recycled powder acted as a grain-size-enlarging promoter in the UO2 pellets.
Epoxy/Fluoroether Composites (1986)

Composite materials made from unfilled and glass-fiber-reinforced epoxy toughened by copolymerization with elastomeric prepolymers of perfluoroalkyl ether diacyl fluoride (EDAF). Improved properties due to hydrogen bonding between rubber phase and epoxy matrix, plus formation of rubberlike phase domains that molecularly interpenetrate with epoxy matrix. With optimum rubber content, particle size, and particle shape, entire molecular structure reinforced and toughened. Improved composites also show increased failure strength, stiffness, glass-transition temperature, and resistance to water.
Defining Components of the Chromosomal Origin of Replication of the Hyperthermophilic Archaeon Pyrococcus furiosus Needed for Construction of a Stable Replicating Shuttle Vector (2011)

We report the construction of a series of replicating shuttle vectors that consist of a low-copy-number cloning vector for Escherichia coli and functional components of the origin of replication (oriC) of the chromosome of the hyperthermophilic archaeon Pyrococcus furiosus. In the process of identifying the minimum replication origin sequence required for autonomous plasmid replication in P. furiosus, we discovered that several features of the origin predicted by bioinformatic analysis and in vitro binding studies were not essential for stable autonomous plasmid replication. A minimum region required to promote plasmid DNA replication was identified, and plasmids based on this sequence readily transformed P. furiosus. The plasmids replicated autonomously and existed in a single copy. In contrast to shuttle vectors based on a plasmid from the closely related hyperthermophile Pyrococcus abyssi for use in P. furiosus, plasmids based on the P. furiosus chromosomal origin were structurally unchanged after transformation and were stable without selection for more than 100 generations.
Optimization of inductor circuits via geometric programming (1999)

We present an efficient method for optimal design and synthesis of CMOS inductors for use in RF circuits. This method uses the the physical dimensions of the inductor as the design parameters and handles a variety of specifications including fixed value of inductance, minimum self-resonant frequency, minimum quality factor, etc. Geometric constraints that can be handled include maximum and minimum values for every design parameter and a limit on total area.
Analysis of anomalous CD44 gene expression in human breast, bladder, and colon cancer and correlation of observed mRNA and protein isoforms. (1996)

Many studies have now demonstrated disorganized overexpression of the CD44 gene in various types of human malignant tumors, and this abnormality has emerged as an interesting candidate marker for early cancer diagnosis. The purpose of this work was to analyze and compare the patterns of transcription and translation of this gene in human breast (ZR75-1; MDAMB-435 clone 4A4) and colon (HT29) tumor cell lines and in tumors of the breast, bladder, and colon, with the aim of identifying the most suitable analyte for diagnostic purposes. Transcription was studied by reverse transcription-polymerase chain reaction using CD44-specific primers and probes complementary to exons in the standard (exons 3 to 5 and 16 to 18) and variably expressed regions of this gene (exons 7, 8, 10, 11, and 15). Translation was investigated by Western blot analysis and immunohistochemistry using monoclonal antibodies specific to the standard form of CD44 and to the products of the same variant exons. Southern blot hybridization analysis of the reverse transcription-polymerase chain reaction products showed a large number of CD44 transcripts in tumor cells. Direct comparison of these Southern blots with Western blots on matched tumor-cell-line extracts indicated that most of the diverse mRNA isoforms did not detectably translate into proteins. However, immunohistochemistry of normal and malignant breast (n = 17 and 23, respectively), bladder (n = 5 and 19), and colon (n = 19 and 19) tissue specimens showed increased staining of CD44 standard and CD44 variant proteins in the carcinoma cells. Combination of this information with the data from reverse transcription-polymerase chain reaction and Western blot analysis indicates that the overexpression at the protein level involves only a minority of the aberrant RNA transcripts. We conclude that the development of methods for the accurate quantitation of over-abundant CD44 RNA species in clinical samples offers the most promising approach to improved early diagnosis of malignancy using this new marker.
Versatile Thin-Film Reactor for Photochemical Vapor Generation (2010)

A novel thin-film reactor is described and evaluated for its analytical performance with photochemical vapor generation (TF-PVG). The device, comprising both the generator and a gas-liquid separator, utilizes a vertical central quartz rod onto which the sample is pumped to yield a thin liquid film conducive to the rapid escape of generated hydrophobic species. The rod is housed within a concentric quartz tube through which a flow of argon carrier/stripping gas is passed to remove and transport the generated species to a detector, which in this study is an inductively coupled argon plasma optical emission spectrometer (ICP-OES). The concentric quartz tube is itself surrounded by a 78-turn 0.5 m long quartz coil low-pressure mercury discharge lamp operating at 20 W. The performance of this thin-film photoreactor was evaluated through comparison of analytical figures of merit for detection of a number of elements undergoing PVG in the presence of formic or acetic acid with those arising from conventional solution nebulization under optimized conditions. The TF-PVG reactor provided sensitivity enhancements, of 110-, 120-, 130-, 250-, 120-, 230-, 78-, 1.3-, 16-, and 32-fold for As, Sb, Bi, Se, Te, Hg, Ni, Co, Fe, and I, respectively, and detection limit enhancements of 110-, 140-, 170-, 270-, 200-, 300-, 160-, 2.7-, 50-, and 44-fold for these same elements. Vapor generation efficiencies ranged from 20-100% for this suite of analytes. The utility of this technique was demonstrated by the determination of Fe and Ni in Certified Reference Materials DORM-3 (fish protein) and DOLT-4 (dogfish liver tissue).
In vitro transcription of two human rotaviruses (1982)

The RNA polymerase activities of a cultivatable (Wa) and a noncultivatable (DS-1) strain of human rotavirus were studied. Under optimal conditions, transcription of all of their RNA segments occurred, as evidenced by the hybridization of labeled transcripts to genomic RNA. Cross-hybridization between the two viruses showed that none of their 11 genes were completely homologous. The transcription products could be translated in vitro, yielding proteins with an electrophoretic pattern resembling that obtained with proteins labeled in vivo during infection with the Wa virus.
TGFβ2 is present in infant formula, resists digestion in vitro and is biologically active (2009)

TGFβ2 is present in human milk and believed to be important for IgA production and oral tolerance. Concentrations are lower in bovine milk, but by utilizing milk protein sources high in TGFβ2, formula TGFβ2 can be increased. We investigated whether TGFβ2 in human milk and formula can resist proteolysis under conditions similar to those in the infant gut. Human milk and formulas were exposed to pepsin at pH 5.0, 3.5 or 2.0 (reflecting increasing maturity of the infant gut) at 37C for 30 min, neutralized to pH 7.0 and incubated for 30 min with pancreatic enzymes. TGFβ2 was analyzed by ELISA. TGFβ bioactivity was assessed by a Smad2 redistribution assay using a Cellomics ArrayScan system and by inhibition of IL‐2 stimulated growth of HT‐2 cells. TGFβ2 levels in formula were variable, but in some cases exceeded those of human milk samples. Digestion with pepsin at pH 2.0 or 3.5 substantially increased immunodetectable TGFβ2 in formula, and digestion with pancreatic enzymes increased it further. This suggests that acidification and/or proteolysis play important roles in liberation of immunodetectable TGFβ2. TGFβ2 in digests (pepsin+pancreatin) was highly bioactive by both assays used. In summary, TGFβ2 in infant formula continues to be immunodetectable and retains activity after in vitro digestion, strongly suggesting that TGFβ2 can survive in the infant gut and exert its biological activities. Supported by Mead Johnson.
Antitumor Agents 288: Design, Synthesis, SAR, and Biological Studies of Novel Heteroatom-Incorporated Antofine and Cryptopleurine Analogues as Potent and Selective Antitumor Agents (2011)

Novel heteroatom-incorporated antofine and cryptopleurine analogues were designed, synthesized, and tested against a panel of five cancer cell lines. Two new S-13-oxo analogues (11 and 16) exhibited potent cell growth inhibition in vitro (GI(50): 9 nM and 20 nM). Interestingly, both compounds displayed improved selectivity among different cancer cell lines, in contrast to the natural products antofine and cryptopleurine. Mechanism of action (MOA) studies suggested that R-antofine promotes dysregulation of DNA replication during early S phase, while no similar effects were observed for 11 and 15 on corresponding replication initiation complexes. Compound 11 also showed greatly reduced cytotoxicity against normal cells and moderate antitumor activity against HT-29 human colorectal adenocarcinoma xenograft in mice without overt toxicity.
NMR of hyperpolarized129Xe in the canine chest: spectral dynamics during a breath-hold (2000)

One of the major goals of hyperpolarized-gas MR imaging has been to obtain (129)Xe dissolved-phase images in humans. Since the dissolved-phase signal is much weaker than the gas-phase signal, highly optimized MR pulse sequences are required to obtain adequate images during a single breath-hold. In particular, a solid understanding of the temporal dynamics of xenon as it passes from the lung gas spaces into the parenchyma, the blood and other downstream compartments is absolutely essential. Spectroscopy experiments were performed in the canine chest to elucidate the behavior of xenon exchange in the lung. The experiments covered a time range from 1 ms to 9 s and therefore considerably extend the data currently available in the literature. It was found that the integrals of the dissolved-phase resonances approached plateau values within approximately 200 ms, and then increased again after approximately 1 s. This behavior suggests an early saturation of the parenchyma before xenon reaches downstream compartments. Mono-exponential recovery curves with time constants on the order of 100 ms were fit to the data. These results potentially provide information on several underlying physiological parameters of the lung, including the parenchymal and blood volumes as well as the diffusion properties of lung tissue.
Optimization of Microresonator Parameters for a Quartz-Enhanced Photoacoustic Spectroscopy Sensor (2009)

A Quartz-Enhanced Photoacoustic Spectroscopy based gas sensor was optimized to improve its compact spectrophone design and performance. The impact of a 2-tube microresonator geometry on the detected signal and signal to noise ratio (SNR) was investigated. Experimental studies demonstrate that the l=4.4mm long tubes (ID=0.5mm) result in a significantly enhanced SNR.
Real-Time System to Calculate the Maximum Load of High-Frequency Torsional Oscillations Independent of Sensor Positioning (2019)

Abstract Cutting forces at the bit or mass imbalances in downhole tools such as mud motors can cause severe vibrations in drillstrings and bottom-hole assemblies (BHA). Negative effects include reduced rate of penetration, low-quality measurements and downhole tool failures. A value that represents the real downhole vibration level is needed to perform a reasonable mitigation strategy. The most common values are statistical values derived from acceleration signals that are received from a sensor at a specific distance from the bit (DfB). The interpretation of an acceleration signal is limited if only one mode shape is dominantly excited. In this case, the measurement signal is very sensitive with respect to the DfB of the sensor placement. The derivation of a representative value for the severity of high-frequency torsional oscillation (HFTO) is shown that is independent of the sensor position. In the proposed approach, the dynamic torsional torque is used in addition to the tangential acceleration measurement. The frequency information of both measurement signals are determined and an analytical model is used to calculate the maximum value of vibration amplitudes that occurs along the BHA. The algorithm is implemented in the measurement-while drilling (MWD) tool for vibration and load measurements. The maximum load value in the BHA corresponding to HFTO can be sent to the surface in real time for interpretation by the driller. In a case study, different scenarios from the field are discussed. The maximum load values are compared to numerical simulations that show an excellent agreement. The maximum value calculated by the approach is factors higher than the values measured by the accelerometers. By using the algorithm-upgrade of the MWD tool, a representative measurement value for the severity of HFTO loads is derived. This is a clear advantage compared to tangential acceleration measurement only. The value enables the driller or an automated advisory system to initiate the optimal HFTO mitigation strategy that leads to reduced levels of vibration with the known benefits for the cost of a well.
ChemInform Abstract: Synthesis of Many Different Types of Organic Small Molecules Using One Automated Process. (2015)

Abstract Small‐molecule synthesis usually relies on procedures that are highly customized for each target.
An Expeditious Synthesis of DPD and Boron Binding Studies (2005)

A practical synthesis has been developed for DPD (4,5-dihydroxypentane-2,3-dione), an unstable small molecule that is proposed to be the source of universal signaling agents for quorum sensing in bacteria. The synthesis allows preparation of isotopically labeled DPD and ent-DPD as well as detailed studies of spontaneous binding to borate to give the unusual borate complex 6, the signal for marine bacteria such as Vibrio harveyi. [reaction: see text]
Fast clamped short circuit protection of IGBTs (2002)

Identification of fault current during the operation of a power semiconductor switch and activation of suitable remedial actions are important for reliable operation of the power converter including the power semiconductor device. A short circuit is a basic and severe fault situation in a circuit structure such as a voltage source converter. This paper presents a new active protection circuit for fast and precise clamping of fault currents and safe shutdown of the IGBTs. This circuit allows operation of the IGBTs with a higher on-state gate voltage, which can thereby reduce the conduction loss in the device without compromising the short circuit protection characteristics. The operation of the circuit is studied under various conditions, considering variation of temperature, the rising rate of fault current, gate voltage value, and circuit parameters. A study of the operation of the circuit is made using IGBTs from different manufacturers to confirm the effectiveness of the protection circuit.
Carbon nanodots for enhanced oil recovery in carbonate reservoirs (2021)

Enhanced oil recovery (EOR) operations in oil-wet carbonate reservoirs face enormous challenges such as long-term chemical and thermal stability issues, high retention and adsorption, diffusion, and, accordingly, an inability to reach deep into the reservoir. This study investigates the EOR potential of Carbon nanodots (CNDs) in coreflood experiments using both outcrop and reservoir carbonate samples. CNDs have excellent colloidal stability and mobility in the harsh carbonate reservoir environment. We also compared its performance against an in-house Gemini surfactant (GS8) of excellent surfactancy properties. Experiments were performed at the ”typical” Saudi Arabian reservoir conditions. We tested three flooding patterns using different rock permeabilities and additive concentrations in the SW. Based on the results, the added oil recovery with CNDs and GS8 ranged from 3%–23% and 6%–22%, respectively. At the same dilute concentration, CNDs are more effective than GS8 in increasing oil recovery. X-ray coreflood experiments provided a real-time 1-D saturation profile. It allowed gauging the efficacy of each additive in situ while tracking the oil and water saturation in and recovery from the carbonate samples. The saturation profiles were compared qualitatively against the oil recovery data from these experiments. Unsteady state, two-phase relative permeability curves of the X-ray coreflood experiments revealed the flow characteristics of oil and water during the injection of different fluids. Both CNDs and GS8 increased the oil’s relative permeability, kro and reduced the water’s relative permeability, krw. Overall, CNDs proved highly efficient, economical, and more scalable than a leading surfactant candidate. CNDs are based on a simple, single-pot synthesis process and have a proven-stability and mobility in the field. And in dilute concentrations (10–200 ppm), it alters the dynamic wettability of the carbonate reservoir favorably. Potentially, these can boost the oil recovery at depths (from the injector) that are unreachable by the conventional surfactants.
Distributed optical fiber sensors (1993)

This critical review paper covers the field of distributed optical fiber sensors, where measurements may be taken along the length of a continuous section of optical fiber. Such a feature greatly increases the information that can be obtained from a single instrument and hence the cost per sensing point can be more acceptable. The review will not attempt to cover all methods, but will give a selection of some of the more interesting theoretical concepts, describe the current status of research and indicate where optical sensing methods are being applied in commercial instruments.