Effect of the load condition on frictional heat generation and temperature increase within a tri-cone bit during high-temperature formation drilling

To investigate the effect of the load condition on frictional heat and temperature within a tri-cone bit, a series of experiments were performed to simulate the mechanical conditions during drilling. The bearing characteristic number, which indicates load conditions such as rotation speed, weight on the bit, and flow resistance, was used to interpret the results. The Stribeck curve of the bearing shows the bearing was in a state of mixed (boundary + elasto-hydrodynamic) lubrication, not in a smooth hydrodynamic lubrication. When drilling high-temperature formations, the bottomhole temperature is higher than that in the experiment, and mixed lubrication progresses to boundary lubrication. The temperature within the bit increases readily, damaging the O-ring seal in the journal bearing.     

Viscoelastic properties and filler dispersion in carbon black‐filled and silica‐filled cross‐linked natural rubbers

The activation energies (ΔE_{J ′} and ΔE_J″) calculated from the temperature dependence of the storage compliance (J′) and the loss compliance (J″) of carbon black (CB)‐filled, hydrophobic silica‐ and hydrophilic silica‐filled cross‐linked natural rubbers (NRs) were found to be less than 15 kJ mol^?1, which corresponds to the physical range of van der Waals interaction. The results of three‐dimensional‐transmission electron microscopy measurements indicate that the closest distance (d_p) between the two neighboring nanofiller aggregates centers decreased sharply with increasing nanofiller loading and tended to become constant at a nanofiller loading of around 30 phr or higher. For all samples examined, there were two regions related to the elastic deformation energy, and the critical d_p value between the two regions was in the order of CB > hydrophobic silica = hydrophilic silica. Additionally, ΔE_J′ developed in the region of longer d_p than that of ΔE_J″. On the other hand, ΔE_J″ occurred after the formation of the filler network and was larger than ΔE_J′. ΔE_J″ is assumed to be related to slippage of the junction and the rearrangement of the nanofiller network. Therefore, the dependence of ΔE_J′ and ΔE_J″ on d_p suggests that the interaction layer between the nanofiller and NR has at least two energy levels. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2594–2602, 2013     

A comparison between Advanced Scatterometer and Weather Research and Forecasting wind speeds for the Japanese offshore wind resource map

This paper investigates the validity of the method used in the Japanese offshore wind map (NeoWins) to seamlessly connecting satellite‐derived wind speed for open oceans to mesoscale model‐simulated wind speed for coastal waters. In the NeoWins, the former was obtained from the satellite‐borne Advanced Scatterometer (ASCAT), and the latter was obtained from numerical simulations using the Weather Research and Forecasting (WRF) model. In this study, the consistency of the ASCAT and WRF 10‐m height wind speeds is examined in their overwrapping areas. The comparison between ASCAT and WRF model reveals that their differences in annual mean wind speed are mostly within ±5% and that the ASCAT annual mean wind speed is, as a whole, slightly higher than the WRF annual mean wind speed. The results indicate that there are no large wind speed gaps between WRF and ASCAT in most parts of the Japanese offshore areas. It is moreover found that the discrepancies between the two wind speeds are due to two factors: one is the existence of winter sea ice in the ASCAT observation in the Sea of Okhotsk in ASCAT observation and the other is that the accuracy of the WRF wind speed depends on atmospheric stability.     

Verification of the Impact of Blood Glucose Level on Liver Carcinogenesis and the Efficacy of a Dietary Intervention in a Spontaneous Metabolic Syndrome Model

Metabolic syndrome (MS) is a risk factor for type 2 diabetes mellitus, vascular inflammation, atherosclerosis, and renal, liver, and heart diseases. Non-alcoholic steatohepatitis (NASH) is a progressive representative liver disease and may lead to the irreversible calamities of cirrhosis and hepatocellular carcinoma. Metabolic disorders such as hyperglycemia have been broadly reported to be related to hepatocarcinogenesis in NASH; however, direct evidence of a link between hyperglycemia and carcinogenesis is still lacking. Tsumura Suzuki Obese Diabetic (TSOD) mice spontaneously develop metabolic syndrome, including obesity, insulin resistance, and NASH-like liver phenotype, and eventually develop hepatocellular carcinomas. TSOD mice provide a spontaneous human MS-like model, even with significant individual variations. In this study, we monitored mice in terms of their changes in blood glucose levels, body weights, and pancreatic and liver lesions over time. As a result, liver carcinogenesis was delayed in non-hyperglycemic TSOD mice compared to hyperglycemic mice. Moreover, at the termination point of 40 weeks, liver tumors appeared in 18 of 24 (75%) hyperglycemic TSOD mice; in contrast, they only appeared in 5 of 24 (20.8%) non-hyperglycemic mice. Next, we investigated three kinds of oligosaccharide that could lower blood glucose levels in hyperglycemic TSOD mice. We monitored the levels of blood and urinary glucose and assessed pancreatic lesions among the experimental groups. As expected, significantly lower levels of blood and urinary glucose and smaller deletions of Langerhans cells were found in TSOD mice fed with milk-derived oligosaccharides (galactooligosaccharides and lactosucrose). At the age of 24 weeks, mild steatohepatitis was found in the liver but there was no evidence of liver carcinogenesis. Steatosis in the liver was alleviated in the milk-derived oligosaccharide-administered group. Taken together, suppressing the increase in blood glucose level from a young age prevented susceptible individuals from diabetes and the onset of NAFLD/NASH, as well as carcinogenesis. Milk-derived oligosaccharides showed a lowering effect on blood glucose levels, which may be expected to prevent liver carcinogenesis.     

The Role of Nutrients in Maintaining Hematopoietic Stem Cells and Healthy Hematopoiesis for Life

Nutrients are converted by the body to smaller molecules, which are utilized for both anabolic and catabolic metabolic reactions. Cooperative regulation of these processes is critical for life-sustaining activities. In this review, we focus on how the regulation of nutrient-driven metabolism maintains healthy hematopoietic stem cells (HSCs). For this purpose, we have examined the metabolic regulation of HSCs from two perspectives: (1) the control of intracellular metabolism by the balance of anabolic and catabolic reactions; and (2) the control of organismal metabolic status and hematopoiesis by dietary intake of nutrients. Critical roles of catabolic regulators in stem cell homeostasis are conserved in several types of tissues, including hematopoiesis. These catabolic signals are also major regulators of organismal lifespan in multiple species. In parallel, changes to nutrients via alterations to dietary intake affect not only an organism’s metabolic state but also the behavior of its stem cells. While the molecular mechanisms involved in these two aspects of nutrient function may not necessarily overlap, a deeper understanding of these phenomena will point to new avenues of medical research and may furnish new agents for improving human health care.     

Rapid determination of iodine value by 1H nuclear magnetic resonance spectroscopy

High-resolution ¹H nuclear magnetic resonance (¹H NMR) has been found to be an effective tool for the direct, rapid, and automated determination of the iodine value (IV) of vegetable oils, including hydrogenated oils (IV=45.9–140.2). The total time required to obtain the ¹H NMR data is about 3 min per sample. The IV is calculated from the number of double-bonded protons and the average molecular weight derived directly from the spectrum. The average of olefinic protons and allylic plus divinyl protons area was used to calculate the absolute number of double-bonded protons. The ¹H NMR results were compared with those obtained by the traditional Wijs-cyclohexane methods. The correlation coefficient between traditional IV and the novel ¹H NMR method was r ²=0.9994 for the regression equation Y=0.9885X + 2.8084, where X was the result given by the traditional method. With the proposed regression equation, IV calculated by the ¹H NMR method was within an error of ± 1 unit of the result obtained by the traditional method. The proposed method is practically viable if one can afford to have the NMR system.     

Advances and Challenges of Antibody Therapeutics for Severe Bronchial Asthma

Asthma is a disease that consists of three main components: airway inflammation, airway hyperresponsiveness, and airway remodeling. Persistent airway inflammation leads to the destruction and degeneration of normal airway tissues, resulting in thickening of the airway wall, decreased reversibility, and increased airway hyperresponsiveness. The progression of irreversible airway narrowing and the associated increase in airway hyperresponsiveness are major factors in severe asthma. This has led to the identification of effective pharmacological targets and the recognition of several biomarkers that enable a more personalized approach to asthma. However, the efficacies of current antibody therapeutics and biomarkers are still unsatisfactory in clinical practice. The establishment of an ideal phenotype classification that will predict the response of antibody treatment is urgently needed. Here, we review recent advancements in antibody therapeutics and novel findings related to the disease process for severe asthma.     

Hot Spot Mutagenesis Improves the Functional Expression of Unique Mammalian Odorant Receptors

Vertebrate animals detect odors through olfactory receptors (ORs), members of the G protein-coupled receptor (GPCR) family. Due to the difficulty in the heterologous expression of ORs, studies of their odor molecule recognition mechanisms have progressed poorly. Functional expression of most ORs in heterologous cells requires the co-expression of their chaperone proteins, receptor transporting proteins (RTPs). Yet, some ORs were found to be functionally expressed without the support of RTP (RTP-independent ORs). In this study, we investigated whether amino acid residues highly conserved among RTP-independent ORs improve the functional expression of ORs in heterologous cells. We found that a single amino acid substitution at one of two sites (N_BW3.39 and 3.43) in their conserved residues (E and L, respectively) significantly improved the functional expression of ORs in heterologous cells. E^3.39 and L^3.43 also enhanced the membrane expression of RTP-dependent ORs in the absence of RTP. These changes did not alter the odorant responsiveness of the tested ORs. Our results showed that specific sites within transmembrane domains regulate the membrane expression of some ORs.