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Sample records for aisi d3 cold

  1. Formation of Expanded Austenite on a Cold-Sprayed AISI 316L Coating by Low-Temperature Plasma Nitriding

    NASA Astrophysics Data System (ADS)

    Adachi, Shinichiro; Ueda, Nobuhiro

    2015-12-01

    Low-temperature plasma nitriding at temperatures below 450 °C is commonly applied to austenitic stainless steels to enhance wear resistance, while maintaining corrosion resistance, by forming expanded austenite (known as the S-phase). In this work, low-temperature plasma nitriding of cold-sprayed AISI 316L coatings was examined. A cold-spray technique was developed to produce metal coatings with less oxidation. However, the cold-sprayed AISI 316L coating obtained by use of nitrogen gas as propellant contained many interconnected pores and cracks, and was, consequently, unsuitable as an anticorrosive coating. Therefore, laser post-treatment was used to modify the coating and increase its density to similar to that of bulk steel. The anticorrosive performance of this coating on a carbon steel substrate in NaCl solution was substantially improved. Subsequent low-temperature plasma nitriding enhanced the wear resistance by two orders of magnitude. It is concluded that cold-sprayed AISI 316L coatings treated by laser post-treatment and subsequent low-temperature plasma nitriding could be used as protective coatings under severe wear and corrosion conditions.

  2. Influence of cold plastic deformation on critical pitting potential of AISI 316 L and 304 L steels in an artificial physiological solution simulating the aggressiveness of the human body.

    PubMed

    Cigada, A; Mazza, B; Pedeferri, P; Sinigaglia, D

    1977-07-01

    The effect of cold working on critical pitting potential of AISI 316 L and 304 L steels in a buffered physiological solution has been studied. In particular, the importance of deformation degree, orientation of the specimen surface to the deformation direction, and cold working temperature in lowering the critical pitting potential is shown. PMID:873942

  3. Microstructure and mechanical behavior of pulsed laser surface melted AISI D2 cold work tool steel

    NASA Astrophysics Data System (ADS)

    Yasavol, N.; Abdollah-zadeh, A.; Ganjali, M.; Alidokht, S. A.

    2013-01-01

    D2 cold work tool steel (CWTS) was subjected to pulse laser surface melting (PLSM) at constant frequency of 20 Hz Nd: YAG laser with different energies, scanning rate and pulse durations radiated to the surface. Characterizing the PLSM, with optical and field emission scanning electron microscopy, electron backscattered diffraction and surface hardness mapping technique was used to evaluate the microhardness and mechanical behavior of different regions of melting pool. Increasing laser energy and reducing the laser scanning rate results in deeper melt pool formation. Moreover, PLSM has led to entirely dissolution of the carbides and re-solidification of cellular/dendritic structure of a fine scale surrounded by a continuous interdendritic network. This caused an increase in surface microhardness, 2-4 times over that of the base metal.

  4. AISI/DOE Technology Roadmap Program: Cold Work Embrittlement of Interstitial Free Steel

    SciTech Connect

    John T Bowker; Pierre Martin

    2002-10-31

    This work addresses the issues of measurement of secondary cold work embrittlement (SCWE) of an IF steel in deep-drawn parts using laboratory tests, and its correlation with real part fracture. It aimed at evaluating the influence of the steel chemistry and processing condition, microstructure, and test conditions, on SCWE as well as the effect of SCWE on fatigue properties. Size 6-in. cups produced with various draw ratios or trimmed at different heights were tested to determine the ductile-to-brittle-transition temperature (DBTT) as a function of strain. The 2-in. cup/expansion test, bend test and fracture of notched specimens were also used to generate information complementary to that provided by the 6-inch cup/expansion test. The relationship between laboratory tests and fracture in real parts was established by testing large-scale parts. The fatigue behavior was investigated in the as-rolled and deep drawn (high stain) conditions, using prestrained specimens taken from the wall of a formed part.

  5. Surface fatigue and failure characteristics of hot-forged powder metal AISI 4620, AISI 4640, and machined AISI 4340 steel spur gears

    NASA Technical Reports Server (NTRS)

    Townsend, Dennis P.

    1987-01-01

    Spur gear surface fatigue endurance tests were conducted to investigate hot forged powder metal AISI 4620 and 4640 steel for use as a gear material, to determine endurance characteristics and to compare the results with machined AISI 4340 and 9310 steel gear materials. The as-forged and unground AISI 4620 gear exhibited a 10 percent fatigue life that was approximately one-fourth of that for AISI 9310 and less than one-half that for the AISI 4340 gears. The forged and finish ground AISI 4620 gears exhibited a 10 percent life, approximately 70 percent that of AISI 9310 and slightly better than that of AISI 4340. The AISI 4640 hot forged gears had less fracture toughness and slightly less fatigue life than the AISI 4620 test gears.

  6. Surface fatigue and failure characteristics of hot forged powder metal AISI 4620, AISI 4640, and machined AISI 4340 steel spur gears

    NASA Technical Reports Server (NTRS)

    Townsend, D. P.

    1986-01-01

    Spur gear surface fatigue endurance tests were conducted to investigate hot forged powder metal AISI 4620 and 4640 steel for use as a gear material, to determine endurance characteristics and to compare the results with machined AISI 4340 and 9310 steel gear materials. The as-forged and unground SISI 4620 gear exhibited a 10 percent fatigue life that was approximately one-fourth of that for AISI 9310 and less than one-half that for the AISI 4340 gears. The forged and finish ground AISI 4620 gears exhibited a 10 percent life, approximately 70 percent that of AISI 9310 and slightly better than that of AISI 4340. The AISI 4640 hot forged gears had less fracture toughness and slightly less fatigue life than the AISI 4620 test gears.

  7. Wear and friction behavior of Zr implanted D3 steel

    SciTech Connect

    Akbas, N.; Saklakoglu, I.E.; Monteiro, O.R.; Brown, I.G.

    2001-08-23

    Multicharged, pure, high current and pulsed ion beams of Zr have been extracted from a metal vapor vacuum arc (MEVVA) source and implanted into AISI D3 (C: 2-2,35%, Mn: 0,60%, Si: 0,60%, Cr: 11-13,50%, Ni: 0,30%, W: 1%, V: 1%) tool steel samples at the 3,6.1016, 5.1016 and 1.1017 ions/cm2 doses. The wear resistance and friction coefficient have been estimated using pin-on-disc wear tests. Implantation of Zr decreased the wear loss and friction coefficient. RBS, AES and SEM Microprobe analyses were used as a guide for explanation of implantation's effects.

  8. [Active vitamin D3 analog].

    PubMed

    Takata, Shinjiro

    2015-10-01

    Vitamin D is a fat-soluble vitamin and exerts effects on skeletal and extraskeletal health in children and adults of all ages. Vitamin D insufficiency is related to low muscle strength, increasing body sway, falls in the elderly. Supplementation with vitamin D reduces risk of osteoporotic fracture, and improves muscle strength and postural balance to prevent the elderly from fall. The preferred vitamin D analog for daily supplementation is cholecalciferol (vitamin D3). The active form of vitamin D3 is 1,25-dihydroxy-vitamin D3. Alfacalcidol, calcitriol and eldecalcitol are used to treat osteoporosis in Japan. Randomized placebo-controlled, double-blinded clinical trial for osteoporotic subjects showed that eldecalcitol is more efficacious to increase bone mineral density and prevent vertebral and wrist fractures in osteoporotic patients with vitamin D sufficiency than alfacalcidol. PMID:26529933

  9. Microstructural interpretation of the fluence and temperature dependence of the mechanical properties of irradiated AISI 316

    SciTech Connect

    Johnson, G.D.; Garner, F.A.; Brager, H.R.; Fish, R.L.

    1980-04-17

    The effects of neutron irradiation on the mechanical properties of annealed and 20% cold-worked AISI 316 irradiated in EBR-II were determined for the temperature regime of 370 to 760/sup 0/C for fluences up to 8.4 x 10/sup 22/ n/cm/sup 2/ (E > 0.1 MeV). At irradiation temperatures below about 500/sup 0/C, both annealed and cold-worked material exhibit a substantial increase in the flow stress with increasing fluence. Furthermore, both materials eventually exhibit the same flow stress, which is independent of fluence. At temperatures in the range of 538 to 650/sup 0/C, the cold-worked material exhibits a softening with increasing fluence. Annealed AISI 316 in this temperature regime exhibits hardening and at a fluence of 2 to 3 x 10/sup 22/ n/cm/sup 2/ (E > 0.1 MeV) reaches the same value of flow stress as the cold-worked material.

  10. The D3 Middleware Architecture

    NASA Technical Reports Server (NTRS)

    Walton, Joan; Filman, Robert E.; Korsmeyer, David J.; Lee, Diana D.; Mak, Ron; Patel, Tarang

    2002-01-01

    DARWIN is a NASA developed, Internet-based system for enabling aerospace researchers to securely and remotely access and collaborate on the analysis of aerospace vehicle design data, primarily the results of wind-tunnel testing and numeric (e.g., computational fluid-dynamics) model executions. DARWIN captures, stores and indexes data; manages derived knowledge (such as visualizations across multiple datasets); and provides an environment for designers to collaborate in the analysis of test results. DARWIN is an interesting application because it supports high-volumes of data. integrates multiple modalities of data display (e.g., images and data visualizations), and provides non-trivial access control mechanisms. DARWIN enables collaboration by allowing not only sharing visualizations of data, but also commentary about and views of data. Here we provide an overview of the architecture of D3, the third generation of DARWIN. Earlier versions of DARWIN were characterized by browser-based interfaces and a hodge-podge of server technologies: CGI scripts, applets, PERL, and so forth. But browsers proved difficult to control, and a proliferation of computational mechanisms proved inefficient and difficult to maintain. D3 substitutes a pure-Java approach for that medley: A Java client communicates (though RMI over HTTPS) with a Java-based application server. Code on the server accesses information from JDBC databases, distributed LDAP security services, and a collaborative information system. D3 is a three tier-architecture, but unlike 'E-commerce' applications, the data usage pattern suggests different strategies than traditional Enterprise Java Beans - we need to move volumes of related data together, considerable processing happens on the client, and the 'business logic' on the server-side is primarily data integration and collaboration. With D3, we are extending DARWIN to handle other data domains and to be a distributed system, where a single login allows a user

  11. Modeling of the AISI Two-Zone Smelter, Part II: Physical Modeling and the AISI Pilot Plant Trials

    SciTech Connect

    Keller, Joseph George; Zhang, X.; Fuehan, R. J.; Vassilicos, A.; Sarma, B.

    2001-06-01

    Physical modeling experiments were conducted for the American Iron and Steel Institute (AISI) two-zone smelter process. The effects of geometrical and operating parameters on backmixing flow rates were investigated. It was found that the driving force for a backmixing flow in the AISI smelter comes from gas stirring in a liquid bath. The backmixing flow rate in the AISI smelter is proportional to a bath depth and an opening area of a barrier. Based on the results of the physical modeling experiments, a dimensional analysis was performed to extrapolate the water modeling results to the operating conditions in the AISI pilot plant. Copper tracer trials were conducted at the AISI pilot plant to investigate the backmixing flow of the AISI two-zone smelter process. The results obtained from the pilot plant trials and the water modeling experiments were compared.

  12. Vitamin D3 and D3 metabolites in young goats fed varying amounts of calcium and vitamin D3.

    PubMed

    Hines, T G; Horst, R L; Littledike, E T; Beitz, D C; Jacobson, N L

    1986-02-01

    Twenty-four male goats, 2 to 4 wk of age, were allotted to four dietary treatments in a 2 X 2 factorial design and, for 20 wk, were fed a milk diet at 12.5% body weight. Treatments varied in amounts of supplemental calcium and vitamin D3. Daily allowances per kilogram body weight were: 9.4 IU vitamin D3 (basal), 9.4 IU vitamin D3 plus 406 mg calcium carbonate (basal plus Ca), 940 IU vitamin D3 (basal plus D3), and 940 IU vitamin D3 plus 406 mg calcium carbonate (basal plus Ca plus D3). At the end of wk 7, a corn supplement was added to all diets at 1% body weight daily. Addition of vitamin D3 to the diet resulted in a dramatic increase in plasma concentrations of vitamin D3. Goats in the basal plus D3 and basal plus Ca plus D3 groups had nearly 100 X greater concentrations of vitamin D3 than goats in the basal and basal plus Ca groups. When greater amounts of vitamin D3 were fed, dietary calcium interacted to decrease plasma vitamin D3 concentrations. Plasma concentrations of 25-hydroxyvitamin D3 were unaffected by additional dietary calcium but were increased by dietary vitamin D3, increasing sixfold to seven-fold in the basal plus D3 and basal plus Ca plus D3 groups. Supplemental calcium resulted in decreased plasma 1,25-dihydroxyvitamin D3. No signs of vitamin D toxicity were noted. The physiological responses reported implicate the goat as a potential animal model for vitamin D research in dairy cattle. PMID:3009577

  13. Study of Carbide Evolution During Thermo-Mechanical Processing of AISI D2 Tool Steel

    NASA Astrophysics Data System (ADS)

    Bombac, D.; Fazarinc, M.; Podder, A. Saha; Kugler, G.

    2013-03-01

    The microstructure of a cold-worked tool steel (AISI D2) with various thermo-mechanical treatments was examined in the current study to identify the effects of these treatments on phases. X-ray diffraction was used to identify phases. Microstructural changes such as spheroidization and coarsening of carbides were studied. Thermodynamic calculations were used to verify the results of the differential thermal analysis. It was found that soaking temperature and time have a large influence on dissolution, precipitation, spheroidization, and coalescence of carbides present in the steel. This consequently influences the hot workability and final properties.

  14. Effect of martensite to austenite reversion on the formation of nano/submicron grained AISI 301 stainless steel

    SciTech Connect

    Karimi, M.; Najafizadeh, A.; Kermanpur, A.; Eskandari, M.

    2009-11-15

    The martensite to austenite reversion behavior of 90% cold rolled AISI 301 stainless steel was investigated in order to refine the grain size. Cold rolled specimens were annealed at 600-900 deg. C, and subsequently characterized by scanning electron microscopy, X-ray diffraction, Feritscope, and hardness measurements. The effects of annealing parameters on the formation of fully-austenitic nano/submicron grained structure and the mechanisms involved were studied. It was found that annealing at 800 deg. C for 10 s exhibited the smallest average austenite grain size of 240 {+-} 60 nm with an almost fully-austenitic structure.

  15. Investigations on the Predictability of Coining Stainless Steel AISI 410

    NASA Astrophysics Data System (ADS)

    Grobbink, S. J.; Klaseboer, G.; Post, J.; Huetink, J.

    2010-06-01

    Due to the increasing trend towards miniaturization, various industries demand the knowledge of materials forming on microscale. Forming has many advantages above machining such as high accuracy, low costs and strengthening by cold-working. However, a drawback of microforming is that it leads to problems caused by so-called size effects. A lot of research has been done on this topic, but only a minor part deals with the forming of high strength materials. In this study two channels with 0.25 mm width and 4.5 mm length are formed in stainless steel sheet AISI 410 with an initial sheet thickness 0.5 mm. The channels are formed by the coining process. The experiments have been repeated in which all dimensions are scaled down by a factor two, in order to check if size effects occur. Ring compression tests are used to determine a shear friction coefficient. A finite element model was build up and solved with MSC.Marc in order to gain a better understanding of the coining process. A size dependent material model known from literature and a conventional material model is used for the simulations. Both results are compared with the experimental results.

  16. 7 CFR 15d.3 - Compliance.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Compliance. 15d.3 Section 15d.3 Agriculture Office of the Secretary of Agriculture NONDISCRIMINATION IN PROGRAMS OR ACTIVITIES CONDUCTED BY THE UNITED STATES DEPARTMENT OF AGRICULTURE § 15d.3 Compliance. The Director of the Office of Civil Rights...

  17. 7 CFR 15d.3 - Compliance.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 1 2012-01-01 2012-01-01 false Compliance. 15d.3 Section 15d.3 Agriculture Office of the Secretary of Agriculture NONDISCRIMINATION IN PROGRAMS OR ACTIVITIES CONDUCTED BY THE UNITED STATES DEPARTMENT OF AGRICULTURE § 15d.3 Compliance. The Director of the Office of Civil Rights...

  18. 7 CFR 15d.3 - Compliance.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 1 2013-01-01 2013-01-01 false Compliance. 15d.3 Section 15d.3 Agriculture Office of the Secretary of Agriculture NONDISCRIMINATION IN PROGRAMS OR ACTIVITIES CONDUCTED BY THE UNITED STATES DEPARTMENT OF AGRICULTURE § 15d.3 Compliance. The Director of the Office of Civil Rights...

  19. 7 CFR 15d.3 - Compliance.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 1 2011-01-01 2011-01-01 false Compliance. 15d.3 Section 15d.3 Agriculture Office of the Secretary of Agriculture NONDISCRIMINATION IN PROGRAMS OR ACTIVITIES CONDUCTED BY THE UNITED STATES DEPARTMENT OF AGRICULTURE § 15d.3 Compliance. The Director of the Office of Civil Rights...

  20. 7 CFR 15d.3 - Compliance.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 1 2014-01-01 2014-01-01 false Compliance. 15d.3 Section 15d.3 Agriculture Office of the Secretary of Agriculture NONDISCRIMINATION IN PROGRAMS OR ACTIVITIES CONDUCTED BY THE UNITED STATES DEPARTMENT OF AGRICULTURE § 15d.3 Compliance. The Director of the Office of Civil Rights...

  1. Determination of Proper Austenitization Temperatures for Hot Stamping of AISI 4140 Steel

    NASA Astrophysics Data System (ADS)

    Samadian, Pedram; Parsa, Mohammad Habibi; Shakeri, Amid

    2014-04-01

    High strength steels are desirable materials for use in automobile bodies in order to reduce vehicle weight and increase the safety of car passengers, but steel grades with high strength commonly show poor formability. Recently, steels with controlled microstructures and compositions are used to gain adequate strength after hot stamping while maintaining good formability during processing. In this study, microstructure evolutions and changes in mechanical properties of AISI 4140 steel sheets resulting from the hot stamping process at different austenitization temperatures were investigated. To determine the proper austenitization temperatures, the results were compared with those of the cold-worked and cold-worked plus quench-tempered specimens. Comparisons showed that the austenitization temperatures of 1000 and 1100 °C are proper for hot stamping of 3-mm-thick AISI 4140 steel sheets due to the resultant martensitic microstructure which led to the yield and ultimate tensile strength of 1.3 and 2.1 GPa, respectively. Such conditions resulted in more favorable simultaneous strength and elongation than those of hot-stamped conventional boron steels.

  2. Hot hardness characteristics of ausformed AISI M-50, Matrix 2, WD-65, modified AISI 440-C, and Super Nitralloy

    NASA Technical Reports Server (NTRS)

    Chevalier, J. L.; Dietrich, M. W.; Zaretsky, E. V.

    1973-01-01

    Short-term hot hardness studies were performed with ausformed AISI M-50, Matrix 2, WD-65, modified AISI 440-C (14-4-1) and case hardened Super Nitralloy. Hardness levels of each material were measured at elevated temperatures in an electric furnace with a low oxygen environment. Test temperatures ranged from 294 to 877 K. The hot hardness characteristics of the ausformed AISI-M-50, Matrix 2 WD-65, and modified AISI 440-C were the same as those determined for high-speed tool steels. Hot hardness for these steels can be predicted within one point Rockwell C. The hot hardness characteristics of both the case and core of Super Nitralloy were superior to AISI 52100 but inferior to the high-speed tool steels. The short-term Rockwell C hardness at temperature for the Super Nitralloy material between 294 and 769 K can be predicted within one point Rockwell C hardness.

  3. Vitamin D3 toxicity in dairy cows.

    PubMed

    Littledike, E T; Horst, R L

    1982-05-01

    Large parenteral doses of vitamin D3 (15 to 17.5 x 10(6) IU vitamin D3) were associated with prolonged hypercalcemia, hyperphosphatemia, and large increases of vitamin D3 and its metabolites in the blood plasma of nonlactating nonpregnant and pregnant Jersey cows. Calcium concentrations 1 day postpartum were higher in cows treated with vitamin D3 about 32 days prepartum (8.8 mg/100 ml) than in control cows (5.5 mg/100 ml). None of the cows treated with vitamin D3 showed signs of milk fever during the peripartal period; however, 22% of the control cows developed clinical signs of milk fever during this period. Signs of vitamin D3 toxicity were not observed in nonlactating nonpregnant cows; however, pregnant cows commonly developed severe signs of vitamin D3 toxicity and 10 of 17 cows died. There was widespread metastatic calcification in the cows that died. Because of the extreme toxicity of vitamin D3 in pregnant Jersey cows and the low margin of safety between doses of vitamin D3 that prevent milk fever and doses that induce milk fever, we concluded that vitamin D3 cannot be used practically to prevent milk fever when injected several weeks prepartum. PMID:6286738

  4. Effects of vitamin D3, 25-hydroxyvitamin D3, and 24,25-dihydroxyvitamin D3 on parathyroid hormone secretion.

    PubMed

    Cantley, L K; Russell, J B; Lettieri, D S; Sherwood, L M

    1987-07-01

    The active vitamin D metabolite 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] causes marked suppression of both pre-proparathyroid hormone messenger RNA (pre-proPTH mRNA) and parathyroid hormone (PTH) secretion. These effects are dose dependent and reversible when tested in an in vitro primary tissue culture cell system using normal bovine parathyroid cells. In the current studies, the precursors of 1,25(OH)2D3 and the related metabolite 24,25-dihydroxyvitamin D3 [24,25(OH)2D3], were used in the same culture system to test for possible regulatory effects. The results were compared with identically prepared cells exposed to 1,25(OH)2D3. In short-term studies (30-120 minutes), none of the vitamin D-related compounds produced any effect on PTH secretion. In long-term studies (24-48 hours, using primary tissue culture in the presence of test agents), neither vitamin D3 nor 25(OH)D3 affected PTH secretion or pre-proPTH mRNA over the concentration range 10(-11)-10(-7) M. On the other hand, 24,25(OH)2D3 produced significant suppression of both pre-proPTH mRNA (77% of control, P less than .01) and PTH secretion (75% of control, P less than .005) at 10(-7) M. By comparison, 10(-11) M 1,25(OH)2D3 produced levels of suppression (25-30%) of both pre-proPTH mRNA and PTH secretion comparable to 10(-7) M 24,25(OH)2D3, while even greater suppression (40-50%) occurred at 10(-9)-10(-7) M 1,25(OH)2D3. From these studies, we conclude that vitamin D3 and 25(OH)D3 do not have significant effects on PTH synthesis and secretion over the range of doses tested.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3040201

  5. Cold Sores

    MedlinePlus

    ... delivered directly to your desktop! more... What Are Cold Sores? Article Chapters What Are Cold Sores? Cold ... January 2012 Previous Next Related Articles: Canker and Cold Sores Aloe Vera May Help Relieve Mouth Sores ...

  6. Improved bioavailability of vitamin D3 using a β-lactoglobulin-based coagulum.

    PubMed

    Diarrassouba, Fatoumata; Garrait, Ghislain; Remondetto, Gabriel; Alvarez, Pedro; Beyssac, Eric; Subirade, Muriel

    2015-04-01

    Vitamin D3 (D3) was encapsulated within a water-soluble matrix, formed by promoting the βlg/D3 complex by acidification. The capacity of the βlg-based coagulum to increase the long term stability of D3 in cold storage, upon exposure to intensive UV-light, and in the presence and absence of intestinal proteases, was evaluated. Additionally, the impact of the sequestration of D3 within the matrix of βlg-based coagulum on its bioavailability was determined in vivo with force-fed rats. The water solubility, long-term storage and UV-light stability of D3 were significantly increased (p < 0.0001) due to the high encapsulation efficiency (94.5 ± 1.8%). The βlg-based coagulum was not rapidly disrupted by the proteases in the intestines, leading to a slow release of D3, increased uptake of D3 and subsequent enhancement of the bioavailability of D3 in rats. PMID:25442565

  7. Food protein-based microspheres for increased uptake of vitamin D3.

    PubMed

    Diarrassouba, Fatoumata; Garrait, Ghislain; Remondetto, Gabriel; Alvarez, Pedro; Beyssac, Eric; Subirade, Muriel

    2015-04-15

    To protect vitamin D3 during cold storage and exposure to UV-light, vitamin D3 has been entrapped in microspheres formed by bovine protein β-lactoglobulin (βlg) and lysozyme (Lyso) from egg white. The behaviour of the βlg/Lyso microspheres in simulated intestinal fluid and their impact on the kinetic release of D3 were determined. The impact of the D3-loaded βlg/Lyso microspheres on the bioavailability of D3 was evaluated in vivo by force-feeding rats. The data indicate that the βlg/Lyso microspheres effectively improved the stability of D3, which was readily released in the intestines. The release kinetics were accelerated in the presence of proteolytic enzymes. The bioavailability of D3 was improved, as confirmed by the significant increase in the serum levels of 25-hydroxy-D3 in rats. The current work demonstrates that water soluble proteins were used to substantially increase the bioavailability of the lipophilic vitamin, and thus can serve in the oral delivery of D3. PMID:25466126

  8. Acoustic Emission Methodology to Evaluate the Fracture Toughness in Heat Treated AISI D2 Tool Steel

    NASA Astrophysics Data System (ADS)

    Mostafavi, Sajad; Fotouhi, Mohamad; Motasemi, Abed; Ahmadi, Mehdi; Sindi, Cevat Teymuri

    2012-10-01

    In this article, fracture toughness behavior of tool steel was investigated using Acoustic Emission (AE) monitoring. Fracture toughness ( K IC) values of a specific tool steel was determined by applying various approaches based on conventional AE parameters, such as Acoustic Emission Cumulative Count (AECC), Acoustic Emission Energy Rate (AEER), and the combination of mechanical characteristics and AE information called sentry function. The critical fracture toughness values during crack propagation were achieved by means of relationship between the integral of the sentry function and cumulative fracture toughness (KICUM). Specimens were selected from AISI D2 cold-work tool steel and were heat treated at four different tempering conditions (300, 450, 525, and 575 °C). The results achieved through AE approaches were then compared with a methodology proposed by compact specimen testing according to ASTM standard E399. It was concluded that AE information was an efficient method to investigate fracture characteristics.

  9. Acoustic emission studies on welded and thermally treated AISI 304 stainless steel during tensile deformation

    SciTech Connect

    Mukherjee, P.; Barat, P.; Jayakumar, T.; Kalyanasundaram, P.; Rajagopalan, C.; Raj, B.

    1997-10-15

    The present investigations are planned to study the influence of prior martensites formed due to cold treatment as 77K in AISI 304 SS welded specimens, on strain-induced martensites occurred during tensile deformation using AE technique. AE parameters like count rate and root mean square (r.m.s.) voltage have been used to characterize AE activities generated during tensile deformation process in as-welded and welded-treated samples. Frequency spectrum analysis of AE signals captured from the samples has been done to understand the dynamic behavior of the martensite phase formation. Tensile properties of these samples have also been reported. Volume fraction of the magnetic phase (martensite and delta ferrite) formed in these samples are measured before and after straining. X-ray diffraction (XRD) technique has been used to support the presence of delta ferrite (formed during welding) and martensite in the weld region.

  10. Laser Surface Hardening of AISI 1045 Steel

    NASA Astrophysics Data System (ADS)

    Li, Ruifeng; Jin, Yajuan; Li, Zhuguo; Qi, Kai

    2014-09-01

    The study investigates laser surface hardening in the AISI 1045 steel using two different types of industrial laser: a high-power diode laser (HPDL) and a CO2 laser, respectively. The effect of process parameters such as beam power, travel speed on structure, case depth, and microhardness was examined. In most cases, a heat-affected zone (HAZ) formed below the surface; a substantial increase in surface hardness was achieved. In addition, big differences were found between the hardened specimens after HPDL surface hardening and CO2 laser surface hardening. For HPDL, depths of the HAZ were almost equal in total HAZ o, without surface melting. For CO2 laser, the depths changed a lot in the HAZ, with surface melting in the center. To better understand the difference of laser hardening results when use these two types of laser, numerical (ANSYS) analysis of the heat conduction involved in the process was also studied. For HPDL method, a rectangular beam spot and uniform energy distribution across the spot were assumed, while for CO2 laser, a circular beam spot and Gaussian energy distribution were assumed. The results showed that the energy distribution variety altered the thermal cycles of the HAZ dramatically. The rectangular HPDL laser beam spot with uniform energy distribution is much more feasible for laser surface hardening.

  11. Cold Stress

    MedlinePlus

    ... be at risk of cold stress. Extreme cold weather is a dangerous situation that can bring on ... the country. In regions relatively unaccustomed to winter weather, near freezing temperatures are considered factors for cold ...

  12. Cold intolerance

    MedlinePlus

    ... intolerance is an abnormal sensitivity to a cold environment or cold temperatures. ... can be a symptom of a problem with metabolism. Some people (often very thin women) do not tolerate cold environments because they have very little body fat and ...

  13. Common cold

    MedlinePlus

    ... are the most common reason that children miss school and parents miss work. Parents often get colds ... other children. A cold can spread quickly through schools or daycares. Colds can occur at any time ...

  14. Common Cold

    MedlinePlus

    ... coughing - everyone knows the symptoms of the common cold. It is probably the most common illness. In ... people in the United States suffer 1 billion colds. You can get a cold by touching your ...

  15. Vitamin D3 and brain development.

    PubMed

    Eyles, D; Brown, J; Mackay-Sim, A; McGrath, J; Feron, F

    2003-01-01

    Evidence for the presence of the vitamin D receptor in brain implies this vitamin may have some function in this organ. This study investigates whether vitamin D(3) acts during brain development. We demonstrate that rats born to vitamin D(3)-deficient mothers had profound alterations in the brain at birth. The cortex was longer but not wider, the lateral ventricles were enlarged, the cortex was proportionally thinner and there was more cell proliferation throughout the brain. There were reductions in brain content of nerve growth factor and glial cell line-derived neurotrophic factor and reduced expression of p75(NTR), the low-affinity neurotrophin receptor. Our findings would suggest that low maternal vitamin D(3) has important ramifications for the developing brain. PMID:12710973

  16. [Vitamin D3 poisoning--case report].

    PubMed

    Heinritzi, K; Hänichen, T; Rambeck, W; Hermanns, W

    2000-12-01

    Over 650 pigs died within a couple hours in a fattening unit with approximately 3,000 fattening spaces. The pigs showed vomiting, dyspnea, kyphosis, sunken flanks, diarrhea, and polyuria. Another striking symptom of the pigs, besides the apathy, was the aphonia, due to the calcification of the vocal cords. An acute vitamin D3-intoxication was found to be the cause. The pathologic findings, especially the histologic detection of calcification processes of the soft tissues, lead to the suspect of an intoxication with a vitamin D-like substance. Between 39,000 and 196,000 IU/kg of vitamin D3 have been detected in a ready-to-use food mix. 8.8 million IU/kg of crystaline vitamin D3 were found in an open whey bag. An explanation how vitamin D came into the bag could not be clarified to this point. PMID:11155516

  17. Resolvin D3 and Aspirin-Triggered Resolvin D3 Are Protective for Injured Epithelia.

    PubMed

    Colby, Jennifer K; Abdulnour, Raja-Elie E; Sham, Ho Pan; Dalli, Jesmond; Colas, Romain A; Winkler, Jeremy W; Hellmann, Jason; Wong, Blenda; Cui, Ye; El-Chemaly, Souheil; Petasis, Nicos A; Spite, Matthew; Serhan, Charles N; Levy, Bruce D

    2016-07-01

    Acute lung injury is a life-threatening condition caused by disruption of the alveolar-capillary barrier leading to edema, influx of inflammatory leukocytes, and impaired gas exchange. Specialized proresolving mediators biosynthesized from essential fatty acids, such as docosahexaenoic acid, have tissue protective effects in acute inflammation. Herein, we found that the docosahexaenoic acid-derived mediator resolvin D3 (RvD3): 4S,11R,17S-trihydroxydocosa-5Z,7E,9E,13Z,15E,19Z-hexaenoic acid was present in uninjured lungs, and increased significantly 24 to 72 hours after hydrochloric acid-initiated injury. Because of its delayed enzymatic degradation, we used aspirin-triggered (AT)-RvD3: 4S,11R,17R-trihydroxydocosa-5Z,7E,9E,13Z,15E,19Z-hexaenoic acid, a 17R-epimer of RvD3, for in vivo experiments. Histopathological correlates of acid injury (alveolar wall thickening, edema, and leukocyte infiltration) were reduced in mice receiving AT-RvD3 1 hour after injury. AT-RvD3-treated mice had significantly reduced edema, as demonstrated by lower wet/dry weight ratios, increased epithelial sodium channel γ expression, and more lymphatic vessel endothelial hyaluronan receptor 1-positive vascular endothelial growth factor receptor 3-positive lymphatic vessels. Evidence for counterregulation of NF-κB by RvD3 and AT-RvD3 was seen in vitro and by AT-RvD3 in vivo. Increases in lung epithelial cell proliferation and bronchoalveolar lavage fluid levels of keratinocyte growth factor were observed with AT-RvD3, which also promoted cutaneous re-epithelialization. Together, these data demonstrate protective actions of RvD3 and AT-RvD3 for injured mucosa that accelerated restoration of epithelial barrier and function. PMID:27171898

  18. "Scrubbing" Data for D3M

    ERIC Educational Resources Information Center

    Mercurius, Neil

    2005-01-01

    Data-driven decision-making (D3M) appears to be the new buzz phrase for this century, the information age. On the education front, teachers and administrators are engaging in data-centered dialog in grade-level meetings, lounges, hallways, and classrooms as they brainstorm toward closing the gap in student achievement. Clearly, such discussion…

  19. 42 CFR 52d.3 - Eligibility.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GRANTS NATIONAL CANCER INSTITUTE CLINICAL CANCER EDUCATION PROGRAM § 52d.3 Eligibility. To be eligible for a grant under this part, an applicant..., affiliated teaching hospital, or specialized cancer institute; and (b) Located in a State, the District...

  20. 42 CFR 52d.3 - Eligibility.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GRANTS NATIONAL CANCER INSTITUTE CLINICAL CANCER EDUCATION PROGRAM § 52d.3 Eligibility. To be eligible for a grant under this part, an applicant..., affiliated teaching hospital, or specialized cancer institute; and (b) Located in a State, the District...

  1. 42 CFR 52d.3 - Eligibility.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GRANTS NATIONAL CANCER INSTITUTE CLINICAL CANCER EDUCATION PROGRAM § 52d.3 Eligibility. To be eligible for a grant under this part, an applicant..., affiliated teaching hospital, or specialized cancer institute; and (b) Located in a State, the District...

  2. 42 CFR 52d.3 - Eligibility.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GRANTS NATIONAL CANCER INSTITUTE CLINICAL CANCER EDUCATION PROGRAM § 52d.3 Eligibility. To be eligible for a grant under this part, an applicant..., affiliated teaching hospital, or specialized cancer institute; and (b) Located in a State, the District...

  3. 42 CFR 52d.3 - Eligibility.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GRANTS NATIONAL CANCER INSTITUTE CLINICAL CANCER EDUCATION PROGRAM § 52d.3 Eligibility. To be eligible for a grant under this part, an applicant..., affiliated teaching hospital, or specialized cancer institute; and (b) Located in a State, the District...

  4. Vitamin D3 in Fat Tissue

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The literature describing vitamin D content of fat tissue is extremely limited. We conducted a pilot study that measured the concentrations of vitamin D3 in the fat tissue and serum of obese adults. These measurements were performed using a new liquid chromatography mass spectrometry (LC/MS) metho...

  5. Primary Human Osteoblasts in Response to 25-Hydroxyvitamin D3, 1,25-Dihydroxyvitamin D3 and 24R,25-Dihydroxyvitamin D3

    PubMed Central

    van der Meijden, Karen; Lips, Paul; van Driel, Marjolein; Heijboer, Annemieke C.; Schulten, Engelbert A. J. M.; den Heijer, Martin; Bravenboer, Nathalie

    2014-01-01

    The most biologically active metabolite 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) has well known direct effects on osteoblast growth and differentiation in vitro. The precursor 25-hydroxyvitamin D3 (25(OH)D3) can affect osteoblast function via conversion to 1,25(OH)2D3, however, it is largely unknown whether 25(OH)D3 can affect primary osteoblast function on its own. Furthermore, 25(OH)D3 is not only converted to 1,25(OH)2D3, but also to 24R,25-dihydroxyvitamin D3 (24R,25(OH)2D3) which may have bioactivity as well. Therefore we used a primary human osteoblast model to examine whether 25(OH)D3 itself can affect osteoblast function using CYP27B1 silencing and to investigate whether 24R,25(OH)2D3 can affect osteoblast function. We showed that primary human osteoblasts responded to both 25(OH)D3 and 1,25(OH)2D3 by reducing their proliferation and enhancing their differentiation by the increase of alkaline phosphatase, osteocalcin and osteopontin expression. Osteoblasts expressed CYP27B1 and CYP24 and synthesized 1,25(OH)2D3 and 24R,25(OH)2D3 dose-dependently. Silencing of CYP27B1 resulted in a decline of 1,25(OH)2D3 synthesis, but we observed no significant differences in mRNA levels of differentiation markers in CYP27B1-silenced cells compared to control cells after treatment with 25(OH)D3. We demonstrated that 24R,25(OH)2D3 increased mRNA levels of alkaline phosphatase, osteocalcin and osteopontin. In addition, 24R,25(OH)2D3 strongly increased CYP24 mRNA. In conclusion, the vitamin D metabolites 25(OH)D3, 1,25(OH)2D3 and 24R,25(OH)2D3 can affect osteoblast differentiation directly or indirectly. We showed that primary human osteoblasts not only respond to 1,25(OH)2D3, but also to 24R,25(OH)2D3 by enhancing osteoblast differentiation. This suggests that 25(OH)D3 can affect osteoblast differentiation via conversion to the active metabolite 1,25(OH)2D3, but also via conversion to 24R,25(OH)2D3. Whether 25(OH)D3 has direct actions on osteoblast function needs further

  6. Colloquium on Large Scale Improvement: Implications for AISI

    ERIC Educational Resources Information Center

    McEwen, Nelly, Ed.

    2008-01-01

    The Alberta Initiative for School Improvement (AISI) is a province-wide partnership program whose goal is to improve student learning and performance by fostering initiatives that reflect the unique needs and circumstances of each school authority. It is currently ending its third cycle and ninth year of implementation. "The Colloquium on Large…

  7. Oxidation and sulfidation of implanted and unimplanted AISI 446 steel

    SciTech Connect

    Srinivasan, V.; McCormick, A.W.; Rai, A.K. )

    1990-12-01

    AISI 446 steel exhibited parabolic rate kinetics from the beginning during isothermal oxidation in oxygen at 850C. On the other hand, a pronounced transient oxidation with faster kinetics was observed in Ce- and Xe-implanted AISI 446 steels. The implantation, however, did not affect the steady-state parabolic rate constant, 3.77{plus minus}0.18{times}10{sup {minus}5} mg{sup 2}/cm{sup 4} min. The initial response of implanted steels to oxidation with pronounced transient oxidation was attributed to the physical defects of implantation. The oxide grains formed on AISI 446 early in the process of oxidation were rich in Fe and Cr, and after long exposure the spinel MnCr{sub 2}O{sub 4} became the major constituent of the scale. Ce-implantation did not have any effect on the corrosion behavior of AISI 446 in H{sub 2}/H{sub 2}O/H{sub 2}S/Ar at 850C. The scale had three zones: an outer layer with FeS, (FeCr)S, and spinel oxide; an intermediate layer of (FeCr)S; and an inner layer of Cr-rich oxide and (FeCr)S below the original metal surface.

  8. Effective hydrodynamics of black D3-branes

    NASA Astrophysics Data System (ADS)

    Emparan, Roberto; Hubeny, Veronika E.; Rangamani, Mukund

    2013-06-01

    The long-wavelength effective field theory of world-volume fluctuations of black D3-branes is shown to be a hydrodynamical system to leading order in a gradient expansion. We study the system on a fiducial `cutoff' surface: the fluctuating geometry imprints its dynamics on the surface via an induced stress tensor whose conservation encapsulates the hydrodynamical description. For a generic non-extremal D3-brane, as we move our cutoff surface from the asymptotically flat near-boundary region to the near-horizon region, this hydrodynamical system interpolates between a non-conformal relativistic fluid and a non-relativistic incompressible fluid. We also consider the dependence on the deviation from extremality of the D3-branes. In the near-extremal case we recover the description in terms of a conformal relativistic fluid encountered in the AdS/CFT context. We argue that this system allows us therefore to explore the various connections that have hitherto been suggested relating the dynamics of gravitational systems and fluid dynamics. In particular, we go on to show that the blackfold effective field theory approach allows us to capture this hydrodynamical behaviour and moreover subsumes the constructions encountered in the fluid/gravity correspondence and the black hole membrane paradigm, providing thereby a universal language to explore the effective dynamics of black branes.

  9. Common Cold

    MedlinePlus

    ... News & Events Volunteer NIAID > Health & Research Topics > Common Cold Skip Website Tools Website Tools Print this page ... Help people who are suffering from the common cold by volunteering for NIAID clinical studies on ClinicalTrials. ...

  10. Human keratinocyte line HaCaT metabolizes 1alpha-hydroxyvitamin D3 and vitamin D3 to 1alpha,25-dihydroxyvitamin D3 (calcitriol).

    PubMed

    Lehmann, B; Pietzsch, J; Kämpf, A; Meurer, M

    1998-11-01

    Cultured human keratinocytes have the property to hydroxylate exogenous 25-hydroxyvitamin D3 (25OHD3) at the C-1alpha position thus producing 1alpha,25-dihydroxyvitamin D3 (1alpha,25(OH)2D3). In this study we investigated whether keratinocytes can also hydroxylate vitamin D3 and one of its metabolites at the C-25 position. We could demonstrate that HaCaT keratinocytes can metabolize 1alpha-hydroxyvitamin D3 (1alpha-OHD3) and vitamin D3 to 1alpha,25(OH)2D3. Identification of the generated product as 1alpha,25(OH)2D3 was based on its elution pattern in two different high performance liquid chromatography systems, on its specific binding in a calf thymus receptor assay and on its gas chromatography-mass spectrometry characteristics. The hydroxylation of vitamin D3 to 1alpha,25(OH)2D3 was dose- and time-dependent. Bovine serum albumin added up to 1.5% (w/v) to the culture medium greatly increased the hydroxylation rates. These results show that HaCaT cells have the capacity to hydroxylate vitamin D3 at the C-1/25 positions. The generation of endogenous 1alpha,25(OH)2D3 from vitamin D3 within the skin may indicate a novel pathway which is of importance for the regulation of epidermal cell growth and differentiation. PMID:9833978

  11. Intersecting D3-branes and holography

    NASA Astrophysics Data System (ADS)

    Constable, Neil R.; Erdmenger, Johanna; Guralnik, Zachary; Kirsch, Ingo

    2003-11-01

    We study a defect conformal field theory describing D3-branes intersecting over two space-time dimensions. This theory admits an exact Lagrangian description which includes both two- and four-dimensional degrees of freedom, has (4,4) supersymmetry and is invariant under global conformal transformations. Both two- and four-dimensional contributions to the action are conveniently obtained in a two-dimensional (2,2) superspace. In a suitable limit, the theory has a dual description in terms of a probe D3-brane wrapping an AdS3×S1 slice of AdS5×S5. We consider the AdS/CFT dictionary for this setup. In particular we find classical probe fluctuations corresponding to the holomorphic curve wy=cα'. These fluctuations are dual to defect fields containing massless two-dimensional scalars which parametrize the classical Higgs branch, but do not correspond to states in the Hilbert space of the CFT. We also identify probe fluctuations which are dual to BPS superconformal primary operators and to their descendants. A nonrenormalization theorem is conjectured for the correlators of these operators, and verified to order g2.

  12. Automated D/3 to Visio Analog Diagrams

    2000-08-10

    ADVAD1 reads an ASCII file containing the D/3 DCS MDL input for analog points for a D/3 continuous database. It uses the information in the files to create a series of Visio files representing the structure of each analog chain, one drawing per Visio file. The actual drawing function is performed by Visio (requires Visio version 4.5+). The user can configure the program to select which fields in the database are shown on the diagrammore » and how the information is to be presented. This gives a visual representation of the structure of the analog chains, showing selected fields in a consistent manner. Updating documentation can be done easily and the automated approach eliminates human error in the cadding process. The program can also create the drawings far faster than a human operator is capable, able to create approximately 270 typical diagrams in about 8 minutes on a Pentium II 400 MHz PC. The program allows for multiple option sets to be saved to provide different settings (i.e., different fields, different field presentations, and /or different diagram layouts) for various scenarios or facilities on one workstation. Option sets may be exported from the Windows registry to allow duplication of settings on another workstation.« less

  13. Irradiation creep and swelling of AISI 316 to exposures of 130 dpa at 385 to 400/sup 0/C

    SciTech Connect

    Garner, F.A.; Porter, D.L.

    1987-09-01

    The creep and swelling of AISI 316 stainless steel have been studied at 385 to 400/sup 0/C in EBR-II to doses of 130 dpa. Most creep capsules were operated at constant stress and temperature but mid-life changes in these variable were also made. This paper concentrates on the behavior of the 20% cold-worked condition but five other conditions were also studied. Swelling at less than or equal to00/sup 0/C was found to lose the sensitivity to stress exhibited at higher temperatures while the creep rate was found to retain linear dependencies on both stress and swelling rate. The creep coefficients extracted at 400/sup 0/C agree with those found in other experiments conducted at higher temperatures. In the temperature range of less than or equal to400/sup 0/C, swelling is in the recombination-dominated regime and the swelling rate falls strongly away from the approx.1%/dpa rate observed at higher temperatures. These lower rates of creep and swelling, coupled with the attainment of high damage levels without failure, encourage the use of AISI 316 in the construction of water-cooled fusion first walls operating at temperatures below 400/sup 0/C. 23 refs., 8 figs.

  14. Tribological properties of CrN coatings deposited by nitro-chromizing treatment on AISI D2 steel

    NASA Astrophysics Data System (ADS)

    Durmaz, M.; Kilinc, B.; Abakay, E.; Sen, U.; Sen, S.

    2015-03-01

    In this work, the wear test of uncoated and chromium nitride coated AISI D2 cold work tool steel against alumina ball realized at 0.1 m/s sliding speeds and under the loads of 2.5N, 5N and 10N. Steel samples were nitrided at 575°C for 8 h in the first step of the coating process, and then chromium nitride coating was performed thermo-reactive deposition technique (TRD) in a powder mixture consisting of ferro-chromium, ammonium chloride and alumina at 1000°C for 2 h. Nitro-chromized samples were characterized by X-Ray diffraction analysis (XRD), scanning electron microscopy (SEM), micro-hardness and ball on disk wear tests. The coating layer formed on the AISI D2 steel was compact and homogeneous. X-ray studies showed that the phase formed in the coated layer is Cr2N. The depth of the layer was 8.15 µm. The average hardness of the layer was 2160±15 HV0.025. For uncoated and chromium nitride materials, wear rate increased with increasing load. The results of friction coefficient and wear rate of the tested materials showed that the CrN coating presents the lowest results.

  15. Tribological properties of CrN coatings deposited by nitro-chromizing treatment on AISI D2 steel

    SciTech Connect

    Durmaz, M. Abakay, E.; Sen, U.; Sen, S.; Kilinc, B.

    2015-03-30

    In this work, the wear test of uncoated and chromium nitride coated AISI D2 cold work tool steel against alumina ball realized at 0.1 m/s sliding speeds and under the loads of 2.5N, 5N and 10N. Steel samples were nitrided at 575°C for 8 h in the first step of the coating process, and then chromium nitride coating was performed thermo-reactive deposition technique (TRD) in a powder mixture consisting of ferro-chromium, ammonium chloride and alumina at 1000°C for 2 h. Nitro-chromized samples were characterized by X-Ray diffraction analysis (XRD), scanning electron microscopy (SEM), micro-hardness and ball on disk wear tests. The coating layer formed on the AISI D2 steel was compact and homogeneous. X-ray studies showed that the phase formed in the coated layer is Cr{sub 2}N. The depth of the layer was 8.15 µm. The average hardness of the layer was 2160±15 HV{sub 0.025}. For uncoated and chromium nitride materials, wear rate increased with increasing load. The results of friction coefficient and wear rate of the tested materials showed that the CrN coating presents the lowest results.

  16. Tribological and corrosion behaviors of carburized AISI 4340 steel

    NASA Astrophysics Data System (ADS)

    Thong-on, Atcharawadi; Boonruang, Chatdanai

    2016-01-01

    AISI 4340 steel is widely used in automotive and aircraft industries as gear components. In such applications, surface hardening processes such as carburizing are required in order to improve the life time of the components. There are many studies showing the tribological behavior of the carburized steel, but the corrosion behavior has not yet been clarified. This paper reports on both tribological and corrosion behaviors of the carburized AISI 4340 steel. Factor associated with carburizing, such as the quantities of deposited carbon, dissolved carbon, and formed Cr23C6 and Fe3C, affect the tribological and corrosion behaviors of the steel by improving hardness, friction, lubrication, and wear resistance; but corrosion resistance is reduced. The dissolved carbon affects the formation of the oxide layer of the carburized steel, by obstructing the continuous oxide layer formation and by decreasing the chromium content of the steel, leading to the decrease in the corrosion resistance of the steel.

  17. The aluminizing in powder technology of AISI 304 steel

    NASA Astrophysics Data System (ADS)

    Băitanu, D. B.; Găluşcă, D. G.; Achiţei, D. C.; Minciună, M. G.; Bakri Abdullah, Mohd Mustafa Al

    2016-06-01

    The paper presents a study about the aluminizing treatments applied to AISI 304 stainless steel, with the purpose to improve the corrosion resistance. The aluminizing is realized in a powder medium, composed by aluminium powder (with 99.95% purity), aluminium oxide Al2O3 and ammonium chloride NH4Cl. The structural characterization was made by scanning electronic microscopy to highlight the structure of layer after aluminizing, at different magnitudes.

  18. Corrosion Resistance of Friction Surfaced AISI 304 Stainless Steel Coatings

    NASA Astrophysics Data System (ADS)

    Khalid Rafi, H.; Phanikumar, G.; Prasad Rao, K.

    2013-02-01

    Corrosion resistance of friction surfaced AISI 304 coating in boiling nitric acid and chloride containing environments was found to be similar to that of its consumable rod counterpart. This was in contrast to the autogenous fusion zone of GTAW weld which showed inferior corrosion resistance with respect to the consumable rod. The superior corrosion resistance of friction surfaced coatings was attributed to the absence of δ-ferrite in it.

  19. Conversion of 25-hydroxyvitamin D3 to 1,25-dihydroxyvitamin D3 and 24,25-dihydroxyvitamin D3 in renal slices from the rat

    SciTech Connect

    Armbrecht, H.J.; Zenser, T.V.; Davis, B.B.

    1981-07-01

    Isolated renal cortical slices were used to study the conversion of 25-hydroxyvitamin D3 to 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) and 24,25-dihydroxyvitamin D3 (24,25)(OH2)D3) by the rat kidney. Production of 1,25-(OH)2D3 and 24,25-(OH)2D3 was linear with time (30-90 min) and tissue weight (40-250 mg). Production of 1,25-(OH)2D3 was greatest (134 +/- 17 pg/mg tissue.h) in animals fed a low calcium, vitamin D-deficient diet. The greatest 24,25-(OH)2D3 production (106 +/- 17 pg/mg tissue.h) was seen in animals fed a high calcium, vitamin D-replete diet, 1,25-(OH)2D3 production was reduced to 23% of maximum by the addition of 1.2% calcium or 0.8% strontium to the vitamin D-deficient, low calcium diet. Production of 1,25-(OH)2D3 and 24,25-(OH)2D3 was greatly reduced in renal cortical slices that had been heated before incubation. Slices of renal medulla produced only small amounts of 1,25-(OH)2D3 compared to slices of renal cortex. These studies provide direct evidence for the production of 1,25-(OH)2D3 and 24,25-(OH)2D3 by the mammalian renal cortex. They also demonstrate that this production may be modulated by dietary calcium, strontium, and vitamin D.

  20. Effect of 24,25-dihydroxyvitamin D3 on 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) metabolism in vitamin D-deficient rats infused with 1,25-(OH)2D3

    SciTech Connect

    Yamato, H.; Matsumoto, T.; Fukumoto, S.; Ikeda, K.; Ishizuka, S.; Ogata, E.

    1989-01-01

    Previous studies revealed that administration of 24,25-dihydroxyvitamin D3 (24,25-(OH)2D3) to calcium (Ca)-deficient rats causes a dose-dependent reduction in markedly elevated serum 1,25-(OH)2D3 level. Although the results suggested that the metabolism of 1,25-(OH)2D3 was accelerated by 24,25-(OH)2D3, those experiments could not define whether the enhanced metabolism of 1,25-(OH)2D3 played a role in the reduction in the serum 1,25-(OH)2D3 level. In the present study, in order to address this issue more specifically, serum 1,25-(OH)2D3 was maintained solely by exogenous administration through miniosmotic pumps of 1,25-(OH)2D3 into vitamin D-deficient rats. Thus, by measuring the serum 1,25-(OH)2D3 concentration, the effect of 24,25-(OH)2D3 on the MCR of 1,25-(OH)2D3 could be examined. Administration of 24,25-(OH)2D3 caused a dose-dependent enhancement in the MCR of 1,25-(OH)2D3, and 1 microgram/100 g rat.day 24,25-(OH)2D3, which elevated serum 24,25-(OH)2D3 to 8.6 +/- 1.3 ng/ml, significantly increased MCR and suppressed serum levels of 1,25-(OH)2D3. The effect of 24,25-(OH)2D3 on 1,25-(OH)2D3 metabolism developed with a rapid time course, and the recovery of iv injected (1 beta-3H)1,25-(OH)2D3 in blood was significantly reduced within 1 h. In addition, there was an increase in radioactivity in the water-soluble fraction of serum as well as in urine, suggesting that 1,25-(OH)2D3 is rapidly degraded to a water-soluble metabolite(s). Furthermore, the reduction in serum 1,25-(OH)2D3 was associated with a reduction in both serum and urinary Ca levels. Because the conversion of (3H)24,25-(OH)2D3 to (3H)1,24,25-(OH)2D3 or other metabolites was minimal in these rats, 24,25-(OH)2D3 appears to act without being converted into other metabolites. These results demonstrate that 24,25-(OH)2D3 rapidly stimulates the metabolism of 1,25-(OH)2D3 and reduces its serum level.

  1. Isolation and identification of vitamin D3, 25-hydroxyvitamin D3, 1,25-dihydroxyvitamin D3 and 1,24,25-trihydroxyvitamin D3 in Solanum malacoxylon incubated with ruminal fluid.

    PubMed

    Skliar, M I; Boland, R L; Mourino, A; Tojo, G

    1992-12-01

    It has been shown that Solanum malacoxylon contains 1 alpha,25-dihydroxyvitamin D3-glycoside. The presence of vitamin D3 and 25-hydroxyvitamin D3 has also been suggested. In the present study vitamin D3 and three of its metabolites, including 1 alpha,25-dihydroxyvitamin D3, were detected in plant leaf extracts preincubated with ruminal fluid (SMRF). Extraction of SMRF with non-polar organic solvents and purification of the lipid extract by TLC followed by HPLC yielded nine ultraviolet-absorbing (264 nm) peaks. Four of them comigrated on a Zorbax-Sil HPLC column with synthetic standards of vitamin D3, 25-hydroxyvitamin D3, 1 alpha,25-dihydroxyvitamin D3 and 1,24R,25-trihydroxyvitamin D3, respectively. These compounds were unequivocally identified by means of mass spectrometry. The results confirm that Solanum malacoxylon contains, in addition to 1 alpha,25-dihydroxyvitamin D3, vitamin D3, 25-hydroxyvitamin D3 and possibly other as yet unidentified derivatives. As 1,24,25-trihydroxyvitamin D3 is absent in plant extracts not incubated with ruminal fluid, the data also indicate that rumen microbes may convert 1 alpha,25-dihydroxyvitamin D3 into 1,24,25-trihydroxyvitamin D3. PMID:1335278

  2. Comparison of pitting fatigue life of ausforged and standard forged AISI M-50 and AISI 9310 spur gears

    NASA Technical Reports Server (NTRS)

    Townsend, D. P.; Bamberger, E. N.; Zaretsky, E. V.

    1975-01-01

    Standard forged and ausforged spur gears made of vacuum-induction-melted, consumable-electrode, vacuum-arc-remelted AISI M-50 steel were tested under conditions that produced fatigue pitting. The gears were 8.89 cm (3.5 in.) in pitch diameter and had tip relief. The M-50 standard forged and ausforged test results were compared with each other. They were then compared with results for machined vacuum-arc-remelted AISI 9310 gears tested under identical conditions. Both types of M-50 gears had lives approximately five times that of the 9310 gears. The life at which 10 percent of the M-50 ausforged gears failed was slightly less than that at which the M-50 standard forged gears failed. The ausforged gears had a slightly greater tendency to fail by tooth fracture than did the standard forged gears, most likely because of the better forging and grain flow pattern of standard forged gears.

  3. Evaluation of Microstructure and Toughness of AISI D2 Steel by Bright Hardening in Comparison with Oil Quenching

    NASA Astrophysics Data System (ADS)

    Torkamani, H.; Raygan, Sh.; Rassizadehghani, J.

    2011-12-01

    AISI D2 is used widely in the manufacture of blanking and cold-forming dies, on account of its excellent hardness and wear behavior. Increasing toughness at a fixed high level of hardness is growing requirement for this kind of tool steel. Improving microstructure characteristics, especially refinement of coarse carbides, is an appropriate way to meet such requirement. In this study, morphology and size of carbides in martensite matrix were compared between two kinds of samples, which were bright hardened (quenching in hot alkaline salt bath consisting of 60% KOH and 40% NaOH) at 230 °C and quenched in oil bath at 60 °C. Results showed that morphology and distribution of carbides in samples performed by bright hardening were finer and almost spherical compared to that of oil quenched. This microstructure resulted in an improvement in toughness and tensile properties of alloy.

  4. Metabolism of 20-hydroxyvitamin D3 by mouse liver microsomes.

    PubMed

    Cheng, Chloe Y S; Slominski, Andrzej T; Tuckey, Robert C

    2014-10-01

    20-Hydroxyvitamin D3 [20(OH)D3], the major product of CYP11A1 action on vitamin D3, is biologically active and like 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] can inhibit proliferation and promote differentiation of a range of cells, and has anti-inflammatory properties. However, unlike 1,25(OH)2D3, it does not cause toxic hypercalcemia at high doses and is therefore a good candidate for therapeutic use to treat hyperproliferative and autoimmune disorders. In this study we analyzed the ability of mouse liver microsomes to metabolize 20(OH)D3. The two major products were identified from authentic standards as 20,24-dihydroxyvitamin D3 [20,24(OH)2D3] and 20,25-dihydroxyvitamin D3 [20,25(OH)2D3]. The reactions for synthesis of these two products from 20(OH)D3 displayed similar Km values suggesting that they were catalyzed by the same cytochrome P450. Some minor metabolites were produced by reactions with higher Km values for 20(OH)D3. Some metabolites gave mass spectra suggesting that they were the result of hydroxylation followed by dehydrogenation. One product had an increase in the wavelength for maximum absorbance from 263nm seen for 20(OH)D3, to 290nm, suggesting a new double bond was interacting with the vitamin D-triene chromophore. The two major products, 20,24(OH)2D3 and 20,25(OH)2D3 have both previously been shown to have higher potency for inhibition of colony formation by melanoma cells than 20(OH)D3, thus it appears that metabolism of 20(OH)D3 by mouse liver microsomes can generate products with enhanced activity. PMID:25138634

  5. Metabolism of 20-hydroxyvitamin D3 by mouse liver microsomes

    PubMed Central

    Cheng, Chloe Y.S.; Slominski, Andrzej T.; Tuckey, Robert C.

    2014-01-01

    20-Hydroxyvitamin D3 [20(OH)D3], the major product of CYP11A1 action on vitamin D3, is biologically active and like 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] can inhibit proliferation and promote differentiation of a range of cells, and has anti-inflammatory properties. However, unlike 1,25(OH)2D3, it does not cause toxic hypercalcemia at high doses and is therefore a good candidate for therapeutic use to treat hyperproliferative and autoimmune disorders. In this study we analyzed the ability of mouse liver microsomes to metabolize 20(OH)D3. The two major products were identified from authentic standards as 20,24-dihydroxyvitamin D3 [20,24(OH)2D3] and 20,25-dihydroxyvitamin D3 [20,25(OH)2D3]. The reactions for synthesis of these two products from 20(OH)D3 displayed similar Km values suggesting that they were catalyzed by the same cytochrome P450. Some minor metabolites were produced by reactions with higher Km values for 20(OH)D3. Some metabolites gave mass spectra suggesting that they were the result of hydroxylation followed by dehydrogenation. One product had an increase in the wavelength for maximum absorbance from 263 nm seen for 20(OH)D3, to 290 nm, suggesting a new double bond was interacting with the vitamin D-triene chromophore. The two major products, 20,24(OH)2D3 and 20,25(OH)2D3 have both previously been shown to have higher potency for inhibition of colony formation by melanoma cells than 20(OH)D3, thus it appears that metabolism of 20(OH)D3 by mouse liver microsomes can generate products with enhanced activity. PMID:25138634

  6. High Affinity Dopamine D3 Receptor (D3R)-Selective Antagonists Attenuate Heroin Self-Administration in Wild-Type but not D3R Knockout Mice.

    PubMed

    Boateng, Comfort A; Bakare, Oluyomi M; Zhan, Jia; Banala, Ashwini K; Burzynski, Caitlin; Pommier, Elie; Keck, Thomas M; Donthamsetti, Prashant; Javitch, Jonathan A; Rais, Rana; Slusher, Barbara S; Xi, Zheng-Xiong; Newman, Amy Hauck

    2015-08-13

    The dopamine D3 receptor (D3R) is a promising target for the development of pharmacotherapeutics to treat substance use disorders. Several D3R-selective antagonists are effective in animal models of drug abuse, especially in models of relapse. Nevertheless, poor bioavailability, metabolic instability, and/or predicted toxicity have impeded success in translating these drug candidates to clinical use. Herein, we report a series of D3R-selective 4-phenylpiperazines with improved metabolic stability. A subset of these compounds was evaluated for D3R functional efficacy and off-target binding at selected 5-HT receptor subtypes, where significant overlap in SAR with D3R has been observed. Several high affinity D3R antagonists, including compounds 16 (Ki = 0.12 nM) and 32 (Ki = 0.35 nM), showed improved metabolic stability compared to the parent compound, PG648 (6). Notably, 16 and the classic D3R antagonist SB277011A (2) were effective in reducing self-administration of heroin in wild-type but not D3R knockout mice. PMID:26203768

  7. Effects of strain-induced martensite and its reversion on the magnetic properties of AISI 201 austenitic stainless steel

    NASA Astrophysics Data System (ADS)

    Souza Filho, I. R.; Sandim, M. J. R.; Cohen, R.; Nagamine, L. C. C. M.; Hoffmann, J.; Bolmaro, R. E.; Sandim, H. R. Z.

    2016-12-01

    Strain-induced martensite (SIM) and its reversion in a cold-rolled AISI 201 austenitic stainless steel was studied by means of magnetic properties, light optical (LOM) and scanning electron (SEM) microscopy, electron backscatter diffraction (EBSD), texture measurements, and Vickers microhardness testing. According to Thermo-calc© predictions, the BCC phase (residual δ-ferrite and SIM) is expected to be stable until 600 °C. The current material was cold rolled up to 60% thickness reduction and submitted to both isothermal and stepwise annealing up to 800 °C. Magnetic measurements were taken during annealing (in situ) of the samples and also for their post mortem conditions. The Curie temperatures (Tc) of residual δ-ferrite and SIM have similar values between 550 and 600 °C. Besides Tc, the focused magnetic parameters were saturation magnetization (Ms), remanent magnetization (MR), and coercive field (Hc). SIM reversion was found to occur in the range of 600-700 °C in good agreement with Thermo-calc© predictions. The microstructures of the material, annealed at 600 and 700 °C for 1 h, were investigated via EBSD. Microtexture measurements for these samples revealed that the texture components were mainly those found for the 60% cold rolled material. This is an evidence that the SIM reversion occurred by an athermal mechanism.

  8. 26 CFR 1.1503(d)-3 - Foreign use.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 12 2014-04-01 2014-04-01 false Foreign use. 1.1503(d)-3 Section 1.1503(d)-3...) INCOME TAXES (CONTINUED) Administrative Provisions and Other Rules § 1.1503(d)-3 Foreign use. (a) Foreign use—(1) In general. Except as provided in paragraph (c) of this section, a foreign use of a...

  9. 26 CFR 1.1503(d)-3 - Foreign use.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 12 2012-04-01 2012-04-01 false Foreign use. 1.1503(d)-3 Section 1.1503(d)-3...) INCOME TAXES (CONTINUED) Administrative Provisions and Other Rules § 1.1503(d)-3 Foreign use. (a) Foreign use—(1) In general. Except as provided in paragraph (c) of this section, a foreign use of a...

  10. 26 CFR 1.1503(d)-3 - Foreign use.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 12 2011-04-01 2011-04-01 false Foreign use. 1.1503(d)-3 Section 1.1503(d)-3...) INCOME TAXES (CONTINUED) Administrative Provisions and Other Rules § 1.1503(d)-3 Foreign use. (a) Foreign use—(1) In general. Except as provided in paragraph (c) of this section, a foreign use of a...

  11. 26 CFR 1.1503(d)-3 - Foreign use.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 12 2013-04-01 2013-04-01 false Foreign use. 1.1503(d)-3 Section 1.1503(d)-3...) INCOME TAXES (CONTINUED) Administrative Provisions and Other Rules § 1.1503(d)-3 Foreign use. (a) Foreign use—(1) In general. Except as provided in paragraph (c) of this section, a foreign use of a...

  12. 21 CFR 582.5953 - Vitamin D3.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Vitamin D3. 582.5953 Section 582.5953 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... 1 § 582.5953 Vitamin D3. (a) Product. Vitamin D3. (b) Conditions of use. This substance is...

  13. 21 CFR 582.5953 - Vitamin D 3.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Vitamin D 3. 582.5953 Section 582.5953 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... 1 § 582.5953 Vitamin D 3. (a) Product. Vitamin D3. (b) Conditions of use. This substance...

  14. 21 CFR 582.5953 - Vitamin D 3.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Vitamin D 3. 582.5953 Section 582.5953 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... 1 § 582.5953 Vitamin D 3. (a) Product. Vitamin D3. (b) Conditions of use. This substance...

  15. 21 CFR 582.5953 - Vitamin D3.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Vitamin D3. 582.5953 Section 582.5953 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... 1 § 582.5953 Vitamin D3. (a) Product. Vitamin D3. (b) Conditions of use. This substance is...

  16. 21 CFR 582.5953 - Vitamin D3.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Vitamin D3. 582.5953 Section 582.5953 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... 1 § 582.5953 Vitamin D3. (a) Product. Vitamin D3. (b) Conditions of use. This substance is...

  17. A study of cumulative fatigue damage in AISI 4130 steel

    NASA Technical Reports Server (NTRS)

    Jeelani, S.; Musial, M.

    1986-01-01

    Experimental data were obtained using AISI 4130 steel under stress ratios of -1 and 0. A study of cumulative fatigue damage using Miner's and Kramer's equations for stress ratios of -1 and 0 for low-high, low-high-mixed, high-low, and high-low-mixed stress sequences has revealed that there is a close agreement between the theoretical and experimental values of fatigue damage and fatigue life. Kramer's equation predicts less conservative and more realistic cumulative fatigue damage than the popularly used Miner's rule does.

  18. Seawater piping systems designed with AISI 316 and RCP anodes

    SciTech Connect

    Valen, S.; Johnsen, R.; Gartland, P.O.; Drugli, J.M.

    1999-11-01

    Internal cathodic protection by resistor controlled anodes--Resistor controlled Cathodic Protection (RCP)--has been introduced as an alternative method for the prevention of localized corrosion of seawater transportation systems. More than 1000 RCP anodes have been installed in seawater piping systems made from highly alloyed stainless steel which previously had suffered from corrosion. The application of cheaper stainless steels like AISI 316 in combination with RCP anodes results in significant cost savings for the seawater system, and a few systems have been installed. This paper gives a short review of the theoretical background, and a presentation of the experience from some of the installations with these materials and RCP.

  19. Conformational analysis of vitamin D 3 derivatives by molecular mechanics . Part II. 1α,25-dihydroxyvitamin D 3 and analogues

    NASA Astrophysics Data System (ADS)

    Mosquera, Ricardo A.; Rios, Miguel A.; Tovar, Clara A.; Maestro, Miguel

    1989-10-01

    The conformational analysis of vitamin D 3 derivatives, including the biologically active form 1α,25-dihydroxyvitamin D 3 (III) and several synthetic analogues: b-deoxy-1α,25-dihydroxyvitamin D 3 (IV), 3-deoxy-3α-methyl-1α,25-dihydroxyvitamin D 3 (V), 3-deoxy-3β-methyl-1α,25-dihydroxyvitamin D 3 (VI), and 3-deoxy-3,3-dimethyl-1α,25-dihydroxyvitamin D 3 (VII), has been carried out employing Allinger's molecular mechanics method. The results obtained for conformational equilibrium populations are found to be in good agreement with those provided by NMR studies. Comparison of the active form of vitamin D 3 (1α,25-dihydroxyvitamin D 3) with the other species reveals no important geometrical differences.

  20. Common cold

    MedlinePlus

    ... often causes a runny nose, nasal congestion, and sneezing. You may also have a sore throat, cough, ... symptoms are: Nasal congestion Runny nose Scratchy throat Sneezing Adults and older children with colds generally have ...

  1. Cold Intolerance

    MedlinePlus

    ... from the Handbook on the Late Effects of Poliomyelitis for Physicians and Survivors © Cold Intolerance Many polio ... index of Handbook on the Late Effects of Poliomyelitis for Physicians and Survivors © Back to top Contact ...

  2. Atomic diffusion in laser surface modified AISI H13 steel

    NASA Astrophysics Data System (ADS)

    Aqida, S. N.; Brabazon, D.; Naher, S.

    2013-07-01

    This paper presents a laser surface modification process of AISI H13 steel using 0.09 and 0.4 mm of laser spot sizes with an aim to increase surface hardness and investigate elements diffusion in laser modified surface. A Rofin DC-015 diffusion-cooled CO2 slab laser was used to process AISI H13 steel samples. Samples of 10 mm diameter were sectioned to 100 mm length in order to process a predefined circumferential area. The parameters selected for examination were laser peak power, pulse repetition frequency (PRF), and overlap percentage. The hardness properties were tested at 981 mN force. Metallographic study and energy dispersive X-ray spectroscopy (EDXS) were performed to observe presence of elements and their distribution in the sample surface. Maximum hardness achieved in the modified surface was 1017 HV0.1. Change of elements composition in the modified layer region was detected in the laser modified samples. Diffusion possibly occurred for C, Cr, Cu, Ni, and S elements. The potential found for increase in surface hardness represents an important method to sustain tooling life. The EDXS findings signify understanding of processing parameters effect on the modified surface composition.

  3. Cosmic D- and DF-strings from D3D3: Black strings and BPS limit

    SciTech Connect

    Kim, Taekyung; Kim, Yoonbai; Kyae, Bumseok; Lee, Jungjai

    2008-03-15

    We study D- and DF-strings in a D3D3 system by using Dirac-Born-Infeld type action. In the presence of an electric flux from the transverse direction, we discuss gravitating thick D-string solutions of a spatial manifold, S{sup 2}xR{sup 1}, in which straight D-strings stretched along the R{sup 1} direction are attached to the south and north poles of the two-sphere. There is a horizon along its equator, which means the structure of black strings is formed. We also discuss the BPS limit for thin parallel D- and DF-strings in both flat and curved spacetime. We obtain the BPS sum rule for an arbitrarily-separated multistring configuration with a Gaussian type tachyon potential. At the site of each thin BPS D(F)-string, the pressure takes a finite value. We find that there exists a maximum deficit angle {pi} in the conical geometry induced by thin BPS D- and DF-strings.

  4. Cold injuries.

    PubMed

    Long, William B; Edlich, Richard F; Winters, Kathryne L; Britt, L D

    2005-01-01

    Exposure to cold can produce a variety of injuries that occur as a result of man's inability to adapt to cold. These injuries can be divided into localized injury to a body part, systemic hypothermia, or a combination of both. Body temperature may fall as a result of heat loss by radiation, evaporation, conduction, and convection. Hypothermia or systemic cold injury occurs when the core body temperature has decreased to 35 degrees C (95 degrees F) or less. The causes of hypothermia are either primary or secondary. Primary, or accidental, hypothermia occurs in healthy individuals inadequately clothed and exposed to severe cooling. In secondary hypothermia, another illness predisposes the individual to accidental hypothermia. Hypothermia affects multiple organs with symptoms of hypothermia that vary according to the severity of cold injury. The diagnosis of hypothermia is easy if the patient is a mountaineer who is stranded in cold weather. However, it may be more difficult in an elderly patient who has been exposed to a cold environment. In either case, the rectal temperature should be checked with a low-reading thermometer. The general principals of prehospital management are to (1) prevent further heat loss, (2) rewarm the body core temperature in advance of the shell, and (3) avoid precipitating ventricular fibrillation. There are two general techniques of rewarming--passive and active. The mechanisms of peripheral cold injury can be divided into phenomena that affect cells and extracellular fluids (direct effects) and those that disrupt the function of the organized tissue and the integrity of the circulation (indirect effects). Generally, no serious damage is seen until tissue freezing occurs. The mildest form of peripheral cold injury is frostnip. Chilblains represent a more severe form of cold injury than frostnip and occur after exposure to nonfreezing temperatures and damp conditions. Immersion (trench) foot, a disease of the sympathetic nerves and blood

  5. 21 CFR 172.380 - Vitamin D3.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... incorporation by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. You may obtain copies from the... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Vitamin D3. 172.380 Section 172.380 Food and Drugs... Dietary and Nutritional Additives § 172.380 Vitamin D3. Vitamin D3 may be used safely in foods as...

  6. 21 CFR 172.380 - Vitamin D 3;.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... incorporation by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. You may obtain copies from the... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Vitamin D 3;. 172.380 Section 172.380 Food and... Dietary and Nutritional Additives § 172.380 Vitamin D 3;. Vitamin D3 may be used safely in foods as...

  7. 21 CFR 172.380 - Vitamin D3.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... incorporation by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. You may obtain copies from the... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Vitamin D3. 172.380 Section 172.380 Food and Drugs... Dietary and Nutritional Additives § 172.380 Vitamin D3. Vitamin D3 may be used safely in foods as...

  8. 21 CFR 172.380 - Vitamin D3.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... incorporation by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. You may obtain copies from the... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Vitamin D3. 172.380 Section 172.380 Food and Drugs... Dietary and Nutritional Additives § 172.380 Vitamin D3. Vitamin D3 may be used safely in foods as...

  9. COLD TRAP

    DOEpatents

    Milleron, N.

    1963-03-12

    An improved linear-flow cold trap is designed for highvacuum applications such as mitigating back migration of diffusion pump oil moiecules. A central pot of liquid nitrogen is nested within and supported by a surrounding, vertical, helical coil of metai sheet, all enveloped by a larger, upright, cylindrical, vacuum vessel. The vertical interstices between successive turns of the coil afford lineal, axial, high-vacuum passages between open mouths at top and bottom of said vessel, while the coil, being cold by virtue of thermal contact of its innermost turn with the nitrogen pot, affords expansive proximate condensation surfaces. (AEC)

  10. Structure of the Human Dopamine D3 Receptor in Complex with a D2/D3 Selective Antagonist

    SciTech Connect

    Chien, Ellen Y.T.; Liu, Wei; Zhao, Qiang; Katritch, Vsevolod; Han, Gye Won; Hanson, Michael A.; Shi, Lei; Newman, Amy Hauck; Javitch, Jonathan A.; Cherezov, Vadim; Stevens, Raymond C.

    2010-11-30

    Dopamine modulates movement, cognition, and emotion through activation of dopamine G protein-coupled receptors in the brain. The crystal structure of the human dopamine D3 receptor (D3R) in complex with the small molecule D2R/D3R-specific antagonist eticlopride reveals important features of the ligand binding pocket and extracellular loops. On the intracellular side of the receptor, a locked conformation of the ionic lock and two distinctly different conformations of intracellular loop 2 are observed. Docking of R-22, a D3R-selective antagonist, reveals an extracellular extension of the eticlopride binding site that comprises a second binding pocket for the aryl amide of R-22, which differs between the highly homologous D2R and D3R. This difference provides direction to the design of D3R-selective agents for treating drug abuse and other neuropsychiatric indications.

  11. HoxD3 accelerates wound healing in diabetic mice

    SciTech Connect

    Hansen, Scott L.; Myers, Connie A.; Charboneau, Aubri; Young, David M.; and Boudreau, Nancy

    2003-12-01

    Poorly healing diabetic wounds are characterized by diminished collagen production and impaired angiogenesis. HoxD3, a homeobox transcription factor that promotes angiogenesis and collagen synthesis, is up-regulated during normal wound repair whereas its expression is diminished in poorly healing wounds of the genetically diabetic (db/db) mouse. To determine whether restoring expression of HoxD3 would accelerate diabetic wound healing, we devised a novel method of gene transfer, which incorporates HoxD3 plasmid DNA into a methylcellulose film that is placed on wounds created on db/db mice. The HoxD3 transgene was expressed in endothelial cells, fibroblasts, and keratinocytes of the wounds for up to 10 days. More importantly, a single application of HoxD3 to db/db mice resulted in a statistically significant acceleration of wound closure compared to control-treated wounds. Furthermore, we also observed that the HoxD3-mediated improvement in diabetic wound repair was accompanied by increases in mRNA expression of the HoxD3 target genes, Col1A1 and beta 3-integrin leading to enhanced angiogenesis and collagen deposition in the wounds. Although HoxD3-treated wounds also show improved re-epithelialization as compared to control db/db wounds, this effect was not due to direct stimulation of keratinocyte migration by HoxD3. Finally, we show that despite the dramatic increase in collagen synthesis and deposition in HoxD3-treated wounds, these wounds showed normal remodeling and we found no evidence of abnormal wound healing. These results indicate that HoxD3 may provide a means to directly improve collagen deposition, angiogenesis and closure in poorly healing diabetic wounds.

  12. The D3 dopamine receptor: From structural interactions to function.

    PubMed

    Fiorentini, Chiara; Savoia, Paola; Bono, Federica; Tallarico, Paola; Missale, Cristina

    2015-09-01

    Novel structural and functional aspects of the dopamine (DA) D3 receptors (D3R) have been recently described. D3R expressed in dopaminergic neurons have been classically considered to play the role of autoreceptors inhibiting, as the D2R, DA release. However, evidence for D3R-mediated neurotrophic and neuroprotective effects on DA neurons suggests their involvement in preventing pathological alterations leading to neurodegeneration. On the other hand, given its localization and functional role at postsynaptic striatal levels, the D3R may also be involved in the pathogenesis of movement disorders and psychiatric diseases. Functional interactions of D3R with other receptor systems are crucial for the modulation of several physiological events. On this line, the discovery that the D3R can form heteromers with other receptors has opened the possibility of uncover novel molecular mechanisms of brain functions and dysfunctions. This paper summarizes the functional and physical interactions of D3R with other receptors both at pre-synaptic sites, where it is co-expressed with the D2R and nicotinic receptors, and at post-synaptic sites where it interacts with the DA D1 receptors (D1R). The biochemical and functional properties of the D1R-D3R heteromer will be especially discussed. Both D1R and D3R have been in fact implicated in several disorders, including schizophrenia and motor dysfunctions. Therefore, the D1R-D3R heteromer may represent a potential drug target for the treatment of these diseases. PMID:25532864

  13. Effect of tip relief on endurance characteristics of super nitralloy and AISI M-50 spur gears

    NASA Technical Reports Server (NTRS)

    Townsend, D. P.; Zaretsky, E. V.

    1974-01-01

    Tests were conducted with two groups of 8.89-centimeter (3.5-in.) pitch diameter spur gears with standard 20 deg involute profile with tip relief made of CVM Super-Nitralloy (5Ni-2Al) and CVM AISI M-50 at a temperature of 350 K (170 F). Super-Nitralloy gears with tip relief had a life 150 percent that of gears without tip relief. An increased scoring phenomenon was noted with the Super-Nitralloy gears with tip relief. Through-hardened AISI M-50 gears with tip relief failed due to tooth fracture. AISI M-50 gears without tip relief had a life approximately 40 times greater than the AISI M-50 gears with tip relief.

  14. Fretting of AISI 9310 and selected fretting resistant surface treatments

    NASA Technical Reports Server (NTRS)

    Bill, R. C.

    1977-01-01

    Fretting wear experiments were conducted with uncoated AISI 9310 mating surfaces, and with combinations incorporating a selected coating to one of the mating surfaces. Wear measurements and SEM observations indicated that surface fatigue, as made evident by spallation and surface crack formation, is an important mechanism in promoting fretting wear to uncoated 9310. Increasing humidity resulted in accelerated fretting, and a very noticeable difference in nature of the fretting debris. Of the coatings evaluated, aluminum bronze with a polyester additive was most effective at reducing wear and minimizing fretting damage to the mating uncoated surface, by means of a selflubricating film that developed on the fretting surfaces. Chromium plate performed as an effective protective coating, itself resisting fretting and not accelerating damage to the uncoated surface.

  15. Fretting of AISI 9310 and selected fretting resistant surface treatments

    NASA Technical Reports Server (NTRS)

    Bill, R. C.

    1977-01-01

    Fretting wear experiments were conducted with uncoated AISI 9310 mating surfaces, and with combinations incorporating a selected coating to one of the mating surfaces. Wear measurements and SEM observations indicated that surface fatigue, as made evident by spallation and surface crack formation, is an important mechanism in promoting fretting wear to uncoated 9310. Increasing humidity resulted in accelerated fretting, and a very noticeable difference in nature of the fretting debris. Of the coatings evaluated, alumimum bronze with a polyester additive was most effective at reducing wear and minimizing fretting damage to the mating uncoated surface, by means of a self-lubricating film that developed on the fretting surfaces. Chromium plate performed as an effective protective coating, itself resisting fretting and not accelerating damage to the uncoated surface.

  16. Stress Ratio Effect on Ratcheting Behavior of AISI 4340 Steel

    NASA Astrophysics Data System (ADS)

    Divya Bharathi, K.; Dutta, K.

    2016-02-01

    Ratcheting is known as accumulation of plastic strain during asymmetric cyclic loading of metallic materials under non-zero mean stress. This phenomenon reduces fatigue life of engineering materials and thus limits the life prediction capacity of Coffin-Manson relationship. This study intends to investigate the ratcheting behavior in AISI 4340 steel which is mainly used for designing of railway wheel sets, axles, shafts, aircraft components and other machinery parts. The effect of stress ratio on the ratcheting behaviour in both annealed and normalised conditions were investigated for investigated steel. Ratcheting tests were done at different stress ratios of -0.4, -0.6 and -0.8. The results showed that the material responds to hardening behavior and nature of strain accumulation is dependent on the magnitude of stress ratio. The post ratcheted samples showed increase in tensile strength and hardness which increases with increasing stress ratio and these variations in tensile properties are correlated with the induced cyclic hardening.

  17. Simulation of Thermo-viscoplastic Behaviors for AISI 4140 Steel

    NASA Astrophysics Data System (ADS)

    Li, Hong-Bin; Feng, Yun-Li

    2016-04-01

    The thermo-viscoplastic behaviors of AISI 4140 steel are investigated over wide ranges of strain rate and deformation temperature by isothermal compression tests. Based on the experimental results, a unified viscoplastic constitutive model is proposed to describe the hot compressive deformation behaviors of the studied steel. In order to reasonably evaluate the work hardening behaviors, a strain hardening material constant (h0) is expressed as a function of deformation temperature and strain rate in the proposed constitutive model. Also, the sensitivity of initial value of internal variable s to the deformation temperature is discussed. Furthermore, it is found that the initial value of internal variable s can be expressed as a linear function of deformation temperature. Comparisons between the measured and predicted results confirm that the proposed constitutive model can give an accurate and precise estimate of the inelastic stress-strain relationships for the studied high-strength steel.

  18. Pileup Behavior in Sharp Nanoindentation of AISI 1045 Steel

    NASA Astrophysics Data System (ADS)

    Zhu, L. N.; Xu, B. S.; Wang, H. D.; Wang, C. B.

    Experimental measurements have been used to investigate the pileup behavior during nanoindentation with a sharp indenter. The AISI 1045 steels treated by quenching and annealing were examined. The results show that during sharp nanoindentation process, the amount of pileup is related to the residual stress state, the indentation depth and the work hardening. The quenched steel with compressive residual stress will tend to pile up, and the stress-free annealed steel can decrease the pileup height. It is found that the pileup height gradually increases for the two steels as the indentation depth becomes larger. It is also shown that the low work hardening of the two steels can also result in the pileup deformation.

  19. Investment cast AISI H13 tooling for automotive applications

    SciTech Connect

    Maguire, M.C.; Baldwin, M.D.; Hochanadel, P.W.; Edwards, G.R.

    1995-07-01

    While many techniques exist for production of soft tooling, for die casting there is limited recent experience with cast tooling. The most common US alloy used for manufacture of die casting tooling is wrought AISI H13. If the performance of the cast material is comparable to the wrought counterpart, the use of investment cast HI 3 tooling directly from patterns made via rapid prototyping is of considerable interest. A metallurgical study of investment cast H13 was conducted to evaluate the mechanical behavior in simulated die casting applications. Variable thickness plate investment castings of AISI H13 hot work die steel were produced and characterized in the as-cast and heat-treated conditions. The characterization included light microscopy and mechanical testing. Wrought samples of standard and premium grade H13 were heat-treated and characterized similarly for comparison. Microstructural differences were observed in as-cast samples produced in different section thicknesses. Dendrite cell size and carbide morphology constituted the most prominent microstructural differences observed. After a full heat-treatment, microstructural differences between the wrought material and cast materials were slight regardless of section thickness.The mechanical properties of the cast and heat-treated material proved similar to the properties of the standard heat-treated wrought material. A thermal fatigue testing unit was to con-elate the heat checking susceptibility of H13 steel to its processing and consequent microstructural condition. Surface hardness decreased significantly with thermal cycling, and heat checking was observed in as few as 50 cycles. Thermal softening and thermal fatigue susceptibility were quantified and discussed relative to the microstructural conditions created by processing and heat-treatment. It was found that the premium grade wrought H13 steel provided the best overall resistance to heat checking.

  20. Project COLD.

    ERIC Educational Resources Information Center

    Kazanjian, Wendy C.

    1982-01-01

    Describes Project COLD (Climate, Ocean, Land, Discovery) a scientific study of the Polar Regions, a collection of 35 modules used within the framework of existing subjects: oceanography, biology, geology, meterology, geography, social science. Includes a partial list of topics and one activity (geodesic dome) from a module. (Author/SK)

  1. Cold Sores

    MedlinePlus

    ... causes oral herpes, or cold sores. Type 1 herpes virus infects more than half of the U.S. population by the time they reach their 20s. Type 2 usually affects the genital area Some people have no symptoms from the ...

  2. Developmental Vitamin D3 deficiency alters the adult rat brain.

    PubMed

    Féron, F; Burne, T H J; Brown, J; Smith, E; McGrath, J J; Mackay-Sim, A; Eyles, D W

    2005-03-15

    There is growing evidence that Vitamin D(3) (1,25-dihydroxyvitamin D(3)) is involved in brain development. We have recently shown that the brains of newborn rats from Vitamin D(3) deficient dams were larger than controls, had increased cell proliferation, larger lateral ventricles, and reduced cortical thickness. Brains from these animals also had reduced expression of nerve growth factor (NGF) and glial cell line-derived neurotrophic factor. The aim of the current study was to examine if there were any permanent outcomes into adulthood when the offspring of Vitamin D(3) deficient dams were restored to a normal diet. The brains of adult rats were examined at 10 weeks of age after Vitamin D(3) deficiency until birth or weaning. Compared to controls animals that were exposed to transient early Vitamin D(3) deficiency had larger lateral ventricles, reduced NGF protein content, and reduced expression of a number genes involved in neuronal structure, i.e. neurofilament or MAP-2 or neurotransmission, i.e. GABA-A(alpha4). We conclude that transient early life hypovitaminosis D(3) not only disrupts brain development but leads to persistent changes in the adult brain. In light of the high incidence of hypovitaminosis D(3) in women of child-bearing age, the public health implications of these findings warrant attention. PMID:15763180

  3. A Life Study of Ausforged, Standard Forged and Standard Machined AISI M-50 Spur Gears

    NASA Technical Reports Server (NTRS)

    Townsend, D. P.; Bamberger, E. N.; Zaretsky, E. V.

    1975-01-01

    Tests were conducted at 350 K (170 F) with three groups of 8.9 cm (3.5 in.) pitch diameter spur gears made of vacuum induction melted (VIM) consumable-electrode vacuum-arc melted (VAR), AISI M-50 steel and one group of vacuum-arc remelted (VAR) AISI 9310 steel. The pitting fatigue life of the standard forged and ausforged gears was approximately five times that of the VAR AISI 9310 gears and ten times that of the bending fatigue life of the standard machined VIM-VAR AISI M-50 gears run under identical conditions. There was a slight decrease in the 10-percent life of the ausforged gears from that for the standard forged gears, but the difference is not statistically significant. The standard machined gears failed primarily by gear tooth fracture while the forged and ausforged VIM-VAR AISI M-50 and the VAR AISI 9310 gears failed primarily by surface pitting fatigue. The ausforged gears had a slightly greater tendency to fail by tooth fracture than the standard forged gears.

  4. A life study of ausforged, standard forged, and standard machined AISI M-50 spur gears

    NASA Technical Reports Server (NTRS)

    Townsend, D. P.; Zaretsky, E. V.; Bamberger, E. N.

    1975-01-01

    Tests were conducted at 350 K with three groups of 8.9 cm pitch diameter spur gears made of vacuum-induction melted (VIM), vacuum-arc remelted (VAR), AISI M-50 steel and one group of vacuum-arc remelted (VAR) AISI 9310 steel. The pitting fatigue life of the standard forged and ausforged gears was approximately five times that of the VAR AISI 9310 gears and ten times that of the bending fatigue life of the standard machined VIM-VAR AISI M-50 gears run under identical conditions. There was a slight decrease in the 10-percent life of the ausforged gears from that for the standard forged gears. However, the difference is not statistically significant. The standard machined gears failed primarily by gear tooth fracture while the forged and ausforged VIM-VAR AISI M-50 and the VAR AISI 9310 gears failed primarily by surface pitting fatigue. The ausforged gears had a slightly greater tendency to fail by tooth fracture than the standard forged gears.

  5. Study on residual stress of AISI304 TIG welding line with laser shock processing by x-ray stress analyzer

    NASA Astrophysics Data System (ADS)

    Zhang, Y. K.; Kong, D. J.; Yin, S. M.; Feng, A. X.; Lu, J. Z.; Ge, T.

    2006-02-01

    The surface of AISI304 TIG welding line was processed by LSP (laser shock processing). The effects on the microstructure, hardness and residual stress of AISI304 welding line by LSP were observed, and its mechanical properties were researched by SEM (scanning electron microscope) and test device of mechanical property. Residual stresses of AISI304 TIG welding line by LSP were measured with Model X-350A X ray analyzer. The test results show that compressive residual stress values of AISI304 TIG welding line by LSP are about 110MPa. Strengthening effects of AISI304 TIG welding line by LSP is very obvious, and fatigue properties of welding line is improved, and tensile residual stresses of welding line are obviously reduced, the distribution of residual stress tends to equality, and service life of AISI304 TIG welding line is improved.

  6. Modeling and optimization of cylindrical wire electro discharge machining of AISI D3 tool steel using non-dominated sorting genetic algorithm

    NASA Astrophysics Data System (ADS)

    Golshan, Abolfazl; Gohari, Soheil; Ayob, Amran

    2011-10-01

    In this study the influence of Cylindrical Wire Electro Discharge Machining on surface roughness and material removal rate is conducted. From experimental DOE method and mathematical modeling, the importance and correlation between corresponding parameters and process output characterization are studied. The investigated input parameters include electrical current, pulse-off time, voltage, rotation speed and cone angle. The Non-dominated Sorting Genetic Algorithm is then applied on the outputs to generate appropriate optimized models. The optimization procedure shows that the suggested method results in a high performance problem solving.

  7. Corrosion and microstructural analysis data for AISI 316L and AISI 347H stainless steels after exposure to a supercritical water environment

    PubMed Central

    Ruiz, A.; Timke, T.; van de Sande, A.; Heftrich, T.; Novotny, R.; Austin, T.

    2016-01-01

    This article presents corrosion data and microstructural analysis data of austenitic stainless steels AISI 316L and AISI 347H exposed to supercritical water (25 MPa, 550 °C) with 2000 ppb of dissolved oxygen. The corrosion tests lasted a total of 1200 h but were interrupted at 600 h to allow measurements to be made. The microstructural data have been collected in the grain interior and at grain boundaries of the bulk of the materials and at the superficial oxide layer developed during the corrosion exposure. PMID:27158647

  8. Corrosion and microstructural analysis data for AISI 316L and AISI 347H stainless steels after exposure to a supercritical water environment.

    PubMed

    Ruiz, A; Timke, T; van de Sande, A; Heftrich, T; Novotny, R; Austin, T

    2016-06-01

    This article presents corrosion data and microstructural analysis data of austenitic stainless steels AISI 316L and AISI 347H exposed to supercritical water (25 MPa, 550 °C) with 2000 ppb of dissolved oxygen. The corrosion tests lasted a total of 1200 h but were interrupted at 600 h to allow measurements to be made. The microstructural data have been collected in the grain interior and at grain boundaries of the bulk of the materials and at the superficial oxide layer developed during the corrosion exposure. PMID:27158647

  9. Hot, Cold, and Really Cold.

    ERIC Educational Resources Information Center

    Leyden, Michael

    1997-01-01

    Describes a physics experiment investigating temperature prediction and the relationship between the physical properties of heat units, melting, dissolving, states of matter, and energy loss. Details the experimental setup, which requires hot and cold water, a thermometer, and ice. Notes that the experiment employs a deliberate counter-intuitive…

  10. Chilling Out with Colds

    MedlinePlus

    ... most common cold virus, but more than 200 viruses can cause colds. Because there are so many, ... to help you feel better. Take that, cold viruses! continue How Kids Catch Colds Mucus (say: MYOO- ...

  11. Coping with Cold Sores

    MedlinePlus

    ... Here's Help White House Lunch Recipes Coping With Cold Sores KidsHealth > For Kids > Coping With Cold Sores ... sore." What's that? Adam wondered. What Is a Cold Sore? Cold sores are small blisters that is ...

  12. Feeding 25-hydroxyvitamin D3 to improve beef tenderness.

    PubMed

    Wertz, A E; Knight, T J; Trenkle, A; Sonon, R; Horst, R L; Huff-Lonergan, E J; Beitz, D C

    2004-05-01

    The objective of this trial was to determine if a single oral bolus of 25-hydroxyvitamin D3 (25-OH D3) given at various times before slaughter would enhance the tenderness of beef loin steaks. One hundred eight crossbred steers were allotted to 18 pens so that the mean weight of the cattle in each pen was similar. Treatments (25-OH D3 dose [62.5 or 125 mg]) and time of administration of the single oral bolus (4, 7, 21, or 35 d before slaughter) were assigned randomly to each pen of steers. Serial plasma samples were collected at each bolus administration time for control animals. For steers assigned to a treatment group, a baseline blood sample was collected before bolus administration and at each subsequent administration when other treatment groups received their bolus. Plasma samples were assayed for 25-OH D3 and calcium concentrations. Troponin-T degradation and Warner-Bratzler shear force were measured as indicators of tenderness for loin steaks collected at slaughter and aged for 6 or 14 d postmortem. Muscle samples, collected concurrently, were assayed for 25-OH D3 and calcium concentrations. A single oral bolus of 25-OH D3 was sufficient to increase plasma 25-OH D3 concentrations (P < 0.001) through slaughter, regardless of dose or time of bolus administration. The single oral bolus of 25-OH D3, however, did not increase plasma calcium concentrations (P > 0.05). As a result, neither troponin-T degradation nor Warner-Bratzler shear force was improved (P > 0.05) by treatment. Muscle 25-OH D3 concentrations were increased (P > 0.001) by treatment with 25-OH D3. Although sustained plasma 25-OH D3 concentrations did not increase plasma or muscle calcium at slaughter nor influence tenderness, the use of 25-OH D3 as a nutritional means of improving beef tenderness is in its infancy, and more research to delineate an effective dose and the potential interaction of seasonal exposure to ultraviolet light is warranted. PMID:15144081

  13. Role of 25-hydroxyvitamin D3 dose in determining rat 1,25-dihydroxyvitamin D3 production

    SciTech Connect

    Vieth, R.; McCarten, K.; Norwich, K.H. )

    1990-05-01

    To understand the relationships among (1) the dose of 25-hydroxyvitamin D (25(OH)D) in vivo, (2) the activity of 1-hydroxylase in renal mitochondria, and (3) the production of 1,25-dihydroxyvitamin D (1,25(OH)2D) in vivo, we gave rats different chronic or acute doses of 25-hydroxyvitamin D3 (25(OH)D3). We followed the metabolism of intracardially administered (25-hydroxy-26,27-methyl-3H)cholecalciferol (25(OH)(3H)D3) for 24 h before killing by measuring extracts of serum by chromatography. Specific activity of 1-hydroxylase in kidney was measured at death. In rats given 0-2,000 pmol 25(OH)D3 chronically by mouth, there was a dose-dependent decline in the percent of serum radioactivity made up of 1,25-dihydroxy-(26,27-methyl-3H)cholecalciferol (1,25(OH)2(3H)D3) as well as a decline in mitochondrial 1-hydroxylase, and these correlated significantly (r = 0.83, P less than 0.001). Serum %1,25(OH)2(3H)D3 in this experiment ranged from 0.8 to 42%. A small part of this range could be accounted for by a faster metabolic clearance rate (MCR) of 1,25(OH)2D3 from rats supplemented with 25(OH)D3 (MCR, 2.12 +/- 0.10 ml/min) compared with rats restricted in vitamin D (MCR, 0.94 +/- 0.06 ml/min, P less than 0.001). The activity of 1-hydroxylase was by far the major factor determining serum %1,25(OH)2(3H)D3. When different acute doses of 25(OH)D3 were given to rats with identical specific activities of 1-hydroxylase, the resulting 1,25(OH)2D3 concentrations in serum correlated with the 25(OH)D3 dose (r = 0.99, P less than 0.001). We conclude that the behavior of 1-hydroxylase in vivo is analogous to the classic behavior in vitro of an enzyme functioning below its Michaelis constant (Km). The amount of 1-hydroxylase present in renal mitochondria determines the fraction (not simply the quantity) of 25(OH)D metabolized to 1,25(OH)2D3 in vivo.

  14. Tissue distribution of 7-dehydrocholesterol, vitamin D3 and 25-hydroxyvitamin D3 in several species of fishes.

    PubMed

    Takeuchi, A; Okano, T; Sayamoto, M; Sawamura, S; Kobayashi, T; Motosugi, M; Yamakawa, T

    1986-02-01

    A high-performance liquid chromatographic (HPLC) method for simultaneous determination of 7-dehydrocholesterol (7-DHC), vitamin D3 and 25-hydroxyvitamin D3 (25-OH-D3) in tissues of fishes was established, and using this method the tissue distribution of the sterols in lamprey (Entosphenus japonicus), great blue shark (Prionace glauca), skipjack (Katsuwonus pelamis) and albacore (Thunnus alalunga) was investigated. The results are summarized in the following: Although the alimentary canal, gall bladder and roe of lamprey and the alimentary canal of great blue shark contained comparatively high levels of 7-DHC (higher than 2,000 ng/wet tissue g), the other tissues of lamprey and great blue shark and all tissues of skipjack and albacore contained only low levels of 7-DHC (lower than 1,000 ng/g). There was no significant correlation between the levels of 7-DHC and vitamin D3. The contents of 7-DHC in the skin of skipjack and albacore were only 1/1,000 of those in the skin of rats. Although the contents of vitamin D3 in the liver of skipjack and albacore were extremely high (41,240 and 21,000 ng/g, respectively), those in the skin were very low (454 and 257 ng/g, respectively). 25-OH-D3 was detected in the viscera of skipjack, but the levels were not very high (lower than 150 ng/g). These levels were not significantly correlated with those of vitamin D3. The results suggest that large quantities of vitamin D3 in the liver of skipjack and albacore are supplied by other biosynthetic routes or by intake of vitamin D3 rather than by photochemical biosynthesis. PMID:3012050

  15. Study on tempering behaviour of AISI 410 stainless steel

    SciTech Connect

    Chakraborty, Gopa; Das, C.R.; Albert, S.K.; Bhaduri, A.K.; Thomas Paul, V.; Panneerselvam, G.; Dasgupta, Arup

    2015-02-15

    Martensitic stainless steels find extensive applications due to their optimum combination of strength, hardness and wear-resistance in tempered condition. However, this class of steels is susceptible to embrittlement during tempering if it is carried out in a specific temperature range resulting in significant reduction in toughness. Embrittlement of as-normalised AISI 410 martensitic stainless steel, subjected to tempering treatment in the temperature range of 673–923 K was studied using Charpy impact tests followed by metallurgical investigations using field emission scanning electron and transmission electron microscopes. Carbides precipitated during tempering were extracted by electrochemical dissolution of the matrix and identified by X-ray diffraction. Studies indicated that temper embrittlement is highest when the steel is tempered at 823 K. Mostly iron rich carbides are present in the steel subjected to tempering at low temperatures of around 723 K, whereas chromium rich carbides (M{sub 23}C{sub 6}) dominate precipitation at high temperature tempering. The range 773–823 K is the transition temperature range for the precipitates, with both Fe{sub 2}C and M{sub 23}C{sub 6} types of carbides coexisting in the material. The nucleation of Fe{sub 2}C within the martensite lath, during low temperature tempering, has a definite role in the embrittlement of this steel. Embrittlement is not observed at high temperature tempering because of precipitation of M{sub 23}C{sub 6} carbides, instead of Fe{sub 2}C, preferentially along the lath and prior austenite boundaries. Segregation of S and P, which is widely reported as one of the causes for temper embrittlement, could not be detected in the material even through Auger electron spectroscopy studies. - Highlights: • Tempering behaviour of AISI 410 steel is studied within 673–923 K temperature range. • Temperature regime of maximum embrittlement is identified as 773–848 K. • Results show that type of

  16. Novel Gemini vitamin D(3) analogs have potent antitumor activity.

    PubMed

    Saito, Tsuyako; Okamoto, Ryoko; Haritunians, Talin; O'Kelly, James; Uskokovic, Milan; Maehr, Hubert; Marczak, Stanislaw; Jankowski, Pawel; Badr, Riem; Koeffler, H Phillip

    2008-11-01

    The active form of vitamin D(3), 1,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)], modulates proliferation and induces differentiation of many cancer cells. A new class of analogs of vitamin D(3) has been synthesized, having two side-chains attached to carbon-20 (Gemini) and deuterium substituted on one side-chain. We have examined six of these analogs for their ability to inhibit growth of myeloid leukemia (HL-60), prostate (LNCaP, PC-3, DU145), lung (H520), colon (HT-29), and breast (MCF-7) cancer cell lines. Dose-response clonogenic studies showed that all six analogs had greater antiproliferative activities against cancer cells than 1,25(OH)(2)D(3). Although they had similar potency, the most active of these analogs was BXL-01-0120. BXL-01-0120 was 529-fold more potent than 1,25(OH)(2)D(3) in causing 50% clonal growth inhibition (ED(50)) of HL-60 cells. Pulse-exposure studies demonstrated that exposure to BXL-01-120 (10(-9)M, 48h) resulted in 85% clonal inhibition of HL-60 growth. BXL-01-0120 (10(-11)M, 4 days) induced the differentiation marker, CD11b. Also, morphologically differentiation was more prominent compared to 1,25(OH)(2)D(3). Annexin V assay showed that BXL-01-0120 (10(-10)M, 4 days) induced significantly (p<0.05) more apoptosis than 1,25(OH)(2)D(3). In summary, these analogs have a unique structure resulting in extremely potent inhibition of clonal proliferation of various types of cancer cells, especially HL-60 cells. PMID:18938245

  17. Analysis of Human Dopamine D3 Receptor Quaternary Structure*

    PubMed Central

    Marsango, Sara; Caltabiano, Gianluigi; Pou, Chantevy; Varela Liste, María José; Milligan, Graeme

    2015-01-01

    The dopamine D3 receptor is a class A, rhodopsin-like G protein-coupled receptor that can form dimers and/or higher order oligomers. However, the molecular basis for production of these complexes is not well defined. Using combinations of molecular modeling, site-directed mutagenesis, and homogenous time-resolved FRET, the interfaces that allow dopamine D3 receptor monomers to interact were defined and used to describe likely quaternary arrangements of the receptor. These were then compared with published crystal structures of dimeric β1-adrenoreceptor, μ-opioid, and CXCR4 receptors. The data indicate important contributions of residues from within each of transmembrane domains I, II, IV, V, VI, and VII as well as the intracellular helix VIII in the formation of D3-D3 receptor interfaces within homo-oligomers and are consistent with the D3 receptor adopting a β1-adrenoreceptor-like quaternary arrangement. Specifically, results suggest that D3 protomers can interact with each other via at least two distinct interfaces: the first one comprising residues from transmembrane domains I and II along with those from helix VIII and a second one involving transmembrane domains IV and V. Moreover, rather than existing only as distinct dimeric species, the results are consistent with the D3 receptor also assuming a quaternary structure in which two transmembrane domain I-II-helix VIII dimers interact to form a ”rhombic” tetramer via an interface involving residues from transmembrane domains VI and VII. In addition, the results also provide insights into the potential contribution of molecules of cholesterol to the overall organization and potential stability of the D3 receptor and possibly other GPCR quaternary structures. PMID:25931118

  18. Serum level of vitamin D3 in cutaneous melanoma

    PubMed Central

    de Oliveira, Renato Santos; de Oliveira, Daniel Arcuschin; Martinho, Vitor Augusto Melão; Antoneli, Célia Beatriz Gianotti; Marcussi, Ludmilla Altino de Lima; Ferreira, Carlos Eduardo dos Santos

    2014-01-01

    Objective To compare the level of vitamin D3 in cutaneous melanoma patients, with or without disease activity, with reference values and with patients from a general hospital. Methods The serum levels of vitamin D3 were measured in cutaneous melanoma patients, aged 20 to 88 years, both genders, from January 2010 to December 2013. The samples from the general group were processed at Hospital Israelita Albert Einstein (control group). Data analysis was performed using the Statistics software. Results A total of 100 patients were studied, 54 of them men, with mean age of 54.67 years, and 95 Caucasian. Out of these 100 patients, 17 had active disease. The average levels of vitamin D3 in the melanoma patients were lower than the level considered sufficient, but above the average of the control group. Both groups (with or without active disease) of patients showed a similar distribution of vitamin D3 deficiency. Conclusion Vitamin D3 levels in melanoma patients were higher than those of general patients and lower than the reference level. If the reference values are appropriate, a large part of the population had insufficient levels of vitamin D, including those with melanoma, or else, this standard needs to be reevaluated. No difference in vitamin D3 levels was found among melanoma patients with or without active disease. More comprehensive research is needed to assess the relation between vitamin D and melanoma. PMID:25628199

  19. Vitamin D3 and cardiovascular function in rats.

    PubMed Central

    Weishaar, R E; Simpson, R U

    1987-01-01

    We have previously identified a receptor for 1,25-dihydroxyvitamin D3 in myocardial cells (Simpson, R.U. 1983. Circulation. 68:239.). To establish the relevance of this observation, we evaluated the role of the prohormone vitamin D3 in regulating cardiovascular function. In rats maintained on a vitamin D3-deficient diet for nine weeks, increases in systolic blood pressure (BP) and serum creatine phosphokinase (CPK) were observed. These increases coincided with a reduction of serum calcium from 10.3 to 5.6 mg/dl. However, while serum calcium remained depressed throughout the study, increases in BP and serum CPK were transient. After nine weeks of vitamin D3-depletion, but not after six weeks, ventricular and vascular muscle contractile function were also markedly enhanced. The increase in ventricular contractile function could not be prevented by maintaining serum calcium at 9.0 mg/dl during the period of D3-depletion. These observations suggest a primary role for the vitamin D3-endocrine system in regulating cardiovascular function. PMID:3034981

  20. Fatigue of annealed and cold worked stable and unstable stainless steels

    NASA Astrophysics Data System (ADS)

    Schuster, G.; Altstetter, C.

    1983-10-01

    Fatigue crack growth rates (FCGR) in AISI 301 and 302 austenitic stainless steel alloys have been measured in controlled load cycles with R = 0.05. Both annealed and cold rolled conditions were examined. The austenite phase of the AISI 301 alloy was unstable under stress and transformed martensitically to α' to a much greater extent than the AISI 302 alloy. At low values of mean stress the unstable alloy had a lower FCGR than the more stable 302 alloy. The FCGR increased with mean stress until values of mean stress ⪞70 MPa, where the FCGR was independent of mean stress and was the same for both alloys. Various metallographic and macroscopic measurements were made to try to understand this behavior. It was concluded that residual compressive stress due to transformation at the crack tip was responsible for the lower crack growth rates of the unstable 301 alloy. Cold worked specimens had significantly lower crack growth rates than the annealed specimens, and both alloys behaved identically.

  1. COLD TRAPS

    DOEpatents

    Thompson, W.I.

    1958-09-30

    A cold trap is presented for removing a condensable component from a gas mixture by cooling. It consists of a shell, the exterior surface of which is chilled by a refrigerant, and conductive fins welded inside the shell to condense the gas, and distribute the condensate evenly throughout the length of the trap, so that the trap may function until it becomes completely filled with the condensed solid. The contents may then be removed as either a gas or as a liquid by heating the trap. This device has particuinr use as a means for removing uranium hexafluoride from the gaseous diffusion separation process during equipment breakdown and repair periods.

  2. AISI waste oxide recycling program. Final technical report

    SciTech Connect

    Aukrust, E.; Downing, K.B.; Sarma, B.

    1995-08-01

    In March 1995 AISI completed a five-year, $60 million collaborative development program on Direct Steelmaking cost-shared by DOE under the Metals Initiative. This program defined an energy-efficient and environmentally-friendly technology to produce hot metal for steelmaking directly from coal and iron ore pellets without incurring the high capital costs and environmental problems associated with traditional coke oven and blast furnace technology. As it becomes necessary to replace present capacity, this new technology will be favored because of reduced capital costs, higher energy efficiency, and lower operating costs. In April 1994, having failed to move forward with a demonstration plant for direct ironmaking, despite substantial efforts by both Stelco and Geneva Steel, an alternative opportunity was sought to commercialize this new technology without waiting until existing ironmaking capacity needed to be replaced. Recycling and resource recovery of steel plant waste oxides was considered an attractive possibility. This led to approval of a ten-month, $8.3 million joint program with DOE on recycling steel plant waste oxides utilizing this new smelting technology. This highly successful trial program was completed in December 1994. The results of the pilot plant work and a feasibility study for a recycling demonstration plant are presented in this final technical report.

  3. High-temperature oxidation behavior of aluminized AISI 4130 steel

    NASA Astrophysics Data System (ADS)

    Badaruddin, Mohammad; Wang, Chaur Jeng; Wardono, Herry; Tarkono, Asmi, Dwi

    2016-02-01

    AISI 4130 steel was dipped into a molten aluminum bath at 700°C for 16 s to produce an aluminide coating on the steel substrate. The coating, which consisted of an Al-rich layer and an FeAl3 and Fe2Al5 intermetallic layer, strongly adhered to the steel substrate. High-temperature oxidation of the bare steel and aluminized steel was performed by thermogravimetry at 850°C for 49 h in static air. The oxidation products were characterized by scanning electron microscopy and energy-dispersive spectroscopy. The aluminide coating could increase the oxidation resistance of the bare steel by a factor of ˜19. The increase in high-temperature oxidation resistance of the aluminized steel is attributed to the formation of protective alumina scale (α-Al2O3). Although iron oxide nodules grew on the aluminide coating surface, the oxidation rate of the aluminide coatings was very low. After 49 h of oxidation, agglomerates of α-Al2O3 fine grains grew on the rod-shaped FeAl phases.

  4. Abnormal grain growth in AISI 304L stainless steel

    SciTech Connect

    Shirdel, M.; Mirzadeh, H.; Parsa, M.H.

    2014-11-15

    The microstructural evolution during abnormal grain growth (secondary recrystallization) in 304L stainless steel was studied in a wide range of annealing temperatures and times. At relatively low temperatures, the grain growth mode was identified as normal. However, at homologous temperatures between 0.65 (850 °C) and 0.7 (900 °C), the observed transition in grain growth mode from normal to abnormal, which was also evident from the bimodality in grain size distribution histograms, was detected to be caused by the dissolution/coarsening of carbides. The microstructural features such as dispersed carbides were characterized by optical metallography, X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis, and microhardness. Continued annealing to a long time led to the completion of secondary recrystallization and the subsequent reappearance of normal growth mode. Another instance of abnormal grain growth was observed at homologous temperatures higher than 0.8, which may be attributed to the grain boundary faceting/defaceting phenomenon. It was also found that when the size of abnormal grains reached a critical value, their size will not change too much and the grain growth behavior becomes practically stagnant. - Highlights: • Abnormal grain growth (secondary recrystallization) in AISI 304L stainless steel • Exaggerated grain growth due to dissolution/coarsening of carbides • The enrichment of carbide particles by titanium • Abnormal grain growth due to grain boundary faceting at very high temperatures • The stagnancy of abnormal grain growth by annealing beyond a critical time.

  5. Hot compression deformation behavior of AISI 321 austenitic stainless steel

    NASA Astrophysics Data System (ADS)

    Haj, Mehdi; Mansouri, Hojjatollah; Vafaei, Reza; Ebrahimi, Golam Reza; Kanani, Ali

    2013-06-01

    The hot compression behavior of AISI 321 austenitic stainless steel was studied at the temperatures of 950-1100°C and the strain rates of 0.01-1 s-1 using a Baehr DIL-805 deformation dilatometer. The hot deformation equations and the relationship between hot deformation parameters were obtained. It is found that strain rate and deformation temperature significantly influence the flow stress behavior of the steel. The work hardening rate and the peak value of flow stress increase with the decrease of deformation temperature and the increase of strain rate. In addition, the activation energy of deformation ( Q) is calculated as 433.343 kJ/mol. The microstructural evolution during deformation indicates that, at the temperature of 950°C and the strain rate of 0.01 s-1, small circle-like precipitates form along grain boundaries; but at the temperatures above 950°C, the dissolution of such precipitates occurs. Energy-dispersive X-ray analyses indicate that the precipitates are complex carbides of Cr, Fe, Mn, Ni, and Ti.

  6. The Forming of AISI 409 sheets for fan blade manufacturing

    SciTech Connect

    Foroni, F. D.; Menezes, M. A.; Moreira Filho, L. A.

    2007-04-07

    The necessity of adapting the standardized fan models to conditions of higher temperature has emerged due to the growth of concern referring to the consequences of the gas expelling after the Mont Blanc tunnel accident in Italy and France, where even though, with 100 fans in operation, 41 people died. The objective of this work is to present an alternative to the market standard fans considering a new technology in constructing blades. This new technology introduces the use of the stainless steel AISI 409 due to its good to temperatures of gas exhaust from tunnels in fire situation. The innovation is centered in the process of a deep drawing of metallic sheets in order to keep the ideal aerodynamic superficies for the fan ideal performance. Through the impression of circles on the sheet plane it is shown, experimentally, that, during the pressing process, the more deformed regions on the sheet plane of the blade can not reach the deformation limits of the utilized sheet material.

  7. Modeling the Flow Curve of AISI 410 Martensitic Stainless Steel

    NASA Astrophysics Data System (ADS)

    Momeni, A.; Dehghani, K.; Heidari, M.; Vaseghi, M.

    2012-11-01

    In the present study, hot deformation behavior of AISI 410 martensitic stainless steel was investigated and modeled after conducting compression tests at the temperature range of 900-1150 °C and strain rate range of 0.001-1 s-1. At the studied temperature and strain rates, the flow curves were typical of dynamic recrystallization (DRX) showing a hardening peak followed by a softening one, and a steady state. The flow curves up to the peaks were modeled using the Estrin and Mecking equation. The softening due to DRX was also considered to increase the consistency of the developed model. The experimental equation proposed by Cingara and McQueen was also used to model the work hardening region. The results showed that the phenomenological model based on the Estrin and Mecking equation resulted in a better model for the work hardening region. Based on the Avrami equation, a model was developed to estimate the flow softening due to DRX between the peak and the starting point of steady state. The average value of the Avrami exponent was determined as 2.2, and it decreased with the increasing Zener-Hollomon parameter.

  8. The Surface Fatigue Life of Contour Induction Hardened AISI 1552 Gears

    NASA Technical Reports Server (NTRS)

    Townsend, Dennis P.; Turza, Alan; Chaplin, Mike

    1995-01-01

    Two groups of spur gears manufactured from two different materials and heat treatments were endurance tested for surface fatigue life. One group was manufactured from AISI 1552 and was finished ground to a 0.4 micron (16 micro-in.) rms surface finish and then dual frequency contour induction hardened. The second group was manufactured from CEVM AISI 9310 and was carburized, hardened, and ground to a 0.4 micron (16 micro-in.) rms surface finish. The gear pitch diameter was 8.89 cm (3.5 in.). Test conditions were a maximum Hertz stress of 1.71 GPa (248 ksi), a bulk gear temperature of approximately 350 K (170 F) and a speed of 10,000 rpm. The lubricant used for the tests was a synthetic paraffinic oil with an additive package. The test results showed that the 10 percent surface fatigue (pitting) life of the contour hardened AISI 1552 test gears was 1.7 times that of the carburized and hardened AISI 9310 test gears. Also there were two early failures of the AISI 1552 gears by bending fatigue.

  9. Enzyme immunoassay for measuring 25-hydroxyvitamin D3 in serum.

    PubMed

    Lind, C; Chen, J; Byrjalsen, I

    1997-06-01

    We developed a rapid, competitive enzyme immunoassay (EIA) for measuring 25-hydroxyvitamin D3 [25(OH)D3] in serum. The EIA was based upon 25(OH)D3-3-hemisuccinate covalently coupled to secondary amino groups grafted onto the polystyrene surface of microtiter wells. Optimal coupling conditions were established, and we found that inclusion of 40 mumol/L chloramine T, an agent not previously described for use in coupling to these plates, resulted in both more reproducible coupling as well as more than a twofold increase in the coupling efficiency. Before EIA, 25(OH)D3 was extracted from the serum samples by acetonitrile, and the redissolved extract was incubated with polyclonal rabbit antibody raised against 1,25-dihydroxyvitamin D3-3-hemisuccinate conjugated to bovine serum albumin. Peroxidase-labeled antibody raised in goat against rabbit immunoglobulins was used for detection. The detection limit of the EIA was 4.4 micrograms/L; recovery 102%; on-plate CV 11%; within-run CV including extraction 12%, and between-run CV 15%. There was no clinically important cross-reactivity with other vitamin D metabolites, and results obtained by the EIA were compared with results obtained by a previously described RIA. PMID:9191544

  10. Assessment of Retained Austenite in AISI D2 Tool Steel Using Magnetic Hysteresis and Barkhausen Noise Parameters

    NASA Astrophysics Data System (ADS)

    Kahrobaee, Saeed; Kashefi, Mehrdad

    2015-03-01

    Inaccurate heat treatment process could result in excessive amount of retained austenite, which degrades the mechanical properties, like strength, wear resistance, and hardness of cold work tool steel parts. Thus, to control the mechanical properties, quantitative measurement of the retained austenite is a critical step in optimizing the heat-treating parameters. X-ray diffraction method is the most frequently used technique for this purpose. This technique is, however, destructive and time consuming. Furthermore, it is not applicable to 100% quality inspection of industrial parts. In the present paper, the influence of austenitizing temperature on the retained austenite content and hardness of AISI D2 tool steel has been studied. Additionally, nondestructive magnetic hysteresis parameters of the samples including coercivity, magnetic saturation, and maximum differential permeability as well as their magnetic Barkhausen noise features (RMS peak voltage and peak position) have been investigated. The results revealed direct relations between magnetic saturation, differential permeability, and MBN peak amplitude with increasing austenitizing temperature due to the retained austenite formation. Besides, both parameters of coercivity and peak position had an inverse correlation with the retained austenite fraction.

  11. Surface textural features and its formation process of AISI 304 stainless steel subjected to massive LSP impacts

    NASA Astrophysics Data System (ADS)

    Luo, K. Y.; Yao, H. X.; Dai, F. Z.; Lu, J. Z.

    2014-04-01

    The effects of massive laser shock peening (LSP) impacts on surface textural feature of AISI 304 stainless steel (AISI 304 SS), including surface waviness, surface roughness, and machining texture and direction, have been investigated by using WKYO-NT1100 surface profiler and TR300 stylus roughness shape measuring instrument. Experimental results show that massive LSP impacts have an important influence on the surface waviness of the AISI 304 SS sample, but do not have a measurable impact on the surface roughness. Moreover, massive LSP impacts with constraint and ablation mode generate a novel compound texture on the surface of the AISI 304 SS sample. In addition, the formation process of surface compound texture in AISI 304 SS by massive LSP impacts is also entirely revealed.

  12. Surface fatigue life of CBN and vitreous ground carburized and hardened AISI 9310 spur gears

    NASA Technical Reports Server (NTRS)

    Townsend, Dennis P.; Patel, P. R.

    1988-01-01

    Spur gear surface endurance tests were conducted to investigate CBN ground AISI 9310 spur gears for use in aircraft applications, to determine their endurance characteristics and to compare the results with the endurance of standard vitreous ground AISI 9310 spur gears. Tests were conducted with VIM-VAR AISI 9310 carburized and hardened gears that were finish ground with either CBN or vitreous grinding methods. Test conditions were an inlet oil temeprature of 320 K (116 F), an outlet oil temperature of 350 K (170 F), a maximum Hertz stress of 1.71 GPa (248 ksi), and a speed of 10,000 rpm. The CBN ground gears exhibited a surface fatigue life that was slightly better than the vitreous ground gears. The subsurface residual stress of the CBN ground gears was approximately the same as that for the standard vitreous ground gears for the CBN grinding method used.

  13. Corrosion resistance of the AISI 304, 316 and 321 stainless steel surfaces modified by laser

    NASA Astrophysics Data System (ADS)

    Szubzda, B.; Antończak, A.; Kozioł, P.; Łazarek, Ł.; Stępak, B.; Łęcka, K.; Szmaja, A.; Ozimek, M.

    2016-02-01

    The article presents the analysis results of the influence of laser fluence on physical and chemical structure and corrosion resistance of stainless steel surfaces modified by irradiating with nanosecond-pulsed laser. The study was carried out for AISI 304, AISI 316 and AISI 321 substrates using Yb:glass fiber laser. All measurements were made for samples irradiated in a broad range of accumulated fluence (10÷400 J/cm2). The electrochemical composition (by EDX) and surface morphology (by SEM) of the prepared surfaces were carried out. Finally, corrosion resistance was analyzed by a potentiodynamic electrochemical test. The obtained results showed very high corrosion resistance for samples made by fluency of values lower than 100 J/cm2. In this case, higher values of corrosion potentials and breakdown potentials were observed. A correlation between corrosion phenomena, the range of laser power (fluence) and the results of chemical and structural tests were also found.

  14. D 3 -Brane Model Building and the Supertrace Rule

    NASA Astrophysics Data System (ADS)

    Bena, Iosif; Graña, Mariana; Kuperstein, Stanislav; Ntokos, Praxitelis; Petrini, Michela

    2016-04-01

    A common way to obtain standard-model-like Lagrangians in string theory is to place D 3 -branes inside flux compactifications. The bosonic and fermionic masses and couplings of the resulting gauge theory are determined by the ten-dimensional metric and the fluxes, respectively, and the breaking of supersymmetry is soft. However, not any soft-supersymmetry-breaking Lagrangian can be obtained this way since the string theory equations of motion impose certain relations between the soft couplings. We show that for D 3 -branes in background fluxes, these relations imply that the sums of the squares of the boson and of the fermion masses are equal and that, furthermore, one- and two-loop quantum corrections do not spoil this equality. This makes the use of D 3 -branes for constructing computationally controllable models for physics beyond the standard model problematic.

  15. D3-Brane Model Building and the Supertrace Rule.

    PubMed

    Bena, Iosif; Graña, Mariana; Kuperstein, Stanislav; Ntokos, Praxitelis; Petrini, Michela

    2016-04-01

    A common way to obtain standard-model-like Lagrangians in string theory is to place D3-branes inside flux compactifications. The bosonic and fermionic masses and couplings of the resulting gauge theory are determined by the ten-dimensional metric and the fluxes, respectively, and the breaking of supersymmetry is soft. However, not any soft-supersymmetry-breaking Lagrangian can be obtained this way since the string theory equations of motion impose certain relations between the soft couplings. We show that for D3-branes in background fluxes, these relations imply that the sums of the squares of the boson and of the fermion masses are equal and that, furthermore, one- and two-loop quantum corrections do not spoil this equality. This makes the use of D3-branes for constructing computationally controllable models for physics beyond the standard model problematic. PMID:27104696

  16. Efficient framework for deformable 2D-3D registration

    NASA Astrophysics Data System (ADS)

    Fluck, Oliver; Aharon, Shmuel; Khamene, Ali

    2008-03-01

    Using 2D-3D registration it is possible to extract the body transformation between the coordinate systems of X-ray and volumetric CT images. Our initial motivation is the improvement of accuracy of external beam radiation therapy, an effective method for treating cancer, where CT data play a central role in radiation treatment planning. Rigid body transformation is used to compute the correct patient setup. The drawback of such approaches is that the rigidity assumption on the imaged object is not valid for most of the patient cases, mainly due to respiratory motion. In the present work, we address this limitation by proposing a flexible framework for deformable 2D-3D registration consisting of a learning phase incorporating 4D CT data sets and hardware accelerated free form DRR generation, 2D motion computation, and 2D-3D back projection.

  17. Simultaneous Quantification of 25-Hydroxyvitamin D3 and 24,25-Dihydroxyvitamin D3 in Rats Shows Strong Correlations between Serum and Brain Tissue Levels.

    PubMed

    Xue, Ying; He, Xin; Li, Huan-De; Deng, Yang; Yan, Miao; Cai, Hua-Lin; Tang, Mi-Mi; Dang, Rui-Li; Jiang, Pei

    2015-01-01

    While vitamin D3 is recognized as a neuroactive steroid affecting both brain development and function, efficient analytical method in determining vitamin D3 metabolites in the brain tissue is still lacking, and the relationship of vitamin D3 status between serum and brain remains elusive. Therefore, we developed a novel analysis method by using high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) to simultaneously quantify the concentrations of 25-hydroxyvitamin D3 (25(OH)D3) and 24,25-dihydroxyvitamin D3 (24,25(OH)2D3) in the serum and brain of rats fed with different dose of vitamin D3. We further investigated whether variations of serum vitamin D3 metabolites could affect vitamin D3 metabolite levels in the brain. Serum and brain tissue were analyzed by HPLC-MS/MS with electrospray ionization following derivatization with 4-phenyl-1,2,4-triazoline-3,5-dione (PTAD). The method is highly sensitive, specific, and accurate to quantify 25(OH)D3 and 24,25(OH)2D3 in animal brain tissue. Vitamin D3 metabolites in brain tissue were significantly lower in rats fed with a vitamin D deficiency diet than in rats fed with high vitamin D3 diet. There was also a strong correlation of vitamin D3 metabolites in serum and brain. These results indicate that vitamin D3 status in serum affects bioavailability of vitamin D3 metabolites in the brain. PMID:26713090

  18. Simultaneous Quantification of 25-Hydroxyvitamin D3 and 24,25-Dihydroxyvitamin D3 in Rats Shows Strong Correlations between Serum and Brain Tissue Levels

    PubMed Central

    Xue, Ying; He, Xin; Li, Huan-De; Deng, Yang; Yan, Miao; Cai, Hua-Lin; Tang, Mi-Mi; Dang, Rui-Li; Jiang, Pei

    2015-01-01

    While vitamin D3 is recognized as a neuroactive steroid affecting both brain development and function, efficient analytical method in determining vitamin D3 metabolites in the brain tissue is still lacking, and the relationship of vitamin D3 status between serum and brain remains elusive. Therefore, we developed a novel analysis method by using high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) to simultaneously quantify the concentrations of 25-hydroxyvitamin D3 (25(OH)D3) and 24,25-dihydroxyvitamin D3 (24,25(OH)2D3) in the serum and brain of rats fed with different dose of vitamin D3. We further investigated whether variations of serum vitamin D3 metabolites could affect vitamin D3 metabolite levels in the brain. Serum and brain tissue were analyzed by HPLC-MS/MS with electrospray ionization following derivatization with 4-phenyl-1,2,4-triazoline-3,5-dione (PTAD). The method is highly sensitive, specific, and accurate to quantify 25(OH)D3 and 24,25(OH)2D3 in animal brain tissue. Vitamin D3 metabolites in brain tissue were significantly lower in rats fed with a vitamin D deficiency diet than in rats fed with high vitamin D3 diet. There was also a strong correlation of vitamin D3 metabolites in serum and brain. These results indicate that vitamin D3 status in serum affects bioavailability of vitamin D3 metabolites in the brain. PMID:26713090

  19. Ghost-Free, Finite, Fourth-Order D=3 Gravity

    NASA Astrophysics Data System (ADS)

    Deser, S.

    2009-09-01

    Canonical analysis of a recently proposed linear+quadratic curvature gravity model in D=3 establishes its pure, irreducibly fourth derivative, quadratic curvature limit as both ghost-free and power-counting UV finite, thereby maximally violating standard folklore. This limit is representative of a generic class whose kinetic terms are conformally invariant in any dimension, but it is unique in simultaneously avoiding the transverse-traceless graviton ghosts plaguing D>3 quadratic actions as well as double pole propagators in its other variables. While the two-term model is also unitary, its additional mode’s second-derivative nature forfeits finiteness.

  20. Bitropic D3 Dopamine Receptor Selective Compounds s Potential Antipsychotics.

    PubMed

    Luedtke, Robert R; Rangel-Barajas, Claudia; Malik, Mahinder; Reichert, David E; Mach, R H

    2015-01-01

    Neuropsychiatric disorders represent a substantial social and health care issue. The National Institutes of Health estimates that greater than 2 million adults suffer from neuropsychiatric disorders in the USA. These individuals experience symptoms that can include auditory hallucinations, delusions, unrealistic beliefs and cognitive dysfunction. Although antipsychotic medications are available, suboptimal therapeutic responses are observed for approximately one-third of patients. Therefore, there is still a need to explore new pharmacotherapeutic strategies for the treatment of neuropsychiatric disorders. Many of the medications that are used clinically to treat neuropsychiatric disorders have a pharmacological profile that includes being an antagonist at D2-like (D2, D3 and D4) dopamine receptor subtypes. However, dopamine receptor subtypes are involved in a variety of neuronal circuits that include movement coordination, cognition, emotion, affect, memory and the regulation of prolactin. Consequently, antagonism at D2-like receptors can also contribute to some of the adverse side effects associated with the long-term use of antipsychotics including the a) adverse extrapyramidal symptoms associated with the use of typical antipsychotics and b) metabolic side effects (weight gain, hyperglycemia, increased risk of diabetes mellitus, dyslipidemia and gynecomastia) associated with atypical antipsychotic use. Preclinical studies suggest that D3 versus D2 dopamine receptor selective compounds might represent an alternative strategy for the treatment of the symptoms of schizophrenia. In this review we discuss a) how bitropic Nphenylpiperazine D3 dopamine receptor selective compounds have been developed by modification of the primary (orthosteric) and secondary (allosteric or modulatory) pharmacophores to optimize D3 receptor affinity and D2/D3 binding selectivity ratios and b) the functional selectivity of these compounds. Examples of how these compounds might be

  1. Laser gas assisted treatment of AISI H12 tool steel and corrosion properties

    NASA Astrophysics Data System (ADS)

    Yilbas, B. S.; Toor, Ihsan-ul-Haq; Malik, Jahanzaib; Patel, F.

    2014-03-01

    Laser gas assisted treatment of AISI H12 tool steel surface is carried out and the electrochemical response of the laser treated surface is investigated. Morphological and metallurgical changes in the treated layer are examined using a scanning electron microscope, energy dispersive spectroscopy, and X-ray diffraction. Potentiodynamic polarization tests are carried out for untreated and laser treated specimen in 0.2 M NaCl solution at room temperature. It is found that the laser treated AISI H12 workpiece surfaces exhibit higher corrosion resistance as compared to untreated specimen as confirmed by lower corrosion rate, higher pitting potential, and lower passive current density.

  2. Coupled Multi-Electrode Investigation of Crevice Corrosion of AISI 316 Stainless Steel

    SciTech Connect

    F. Bocher; F. Presuel-Moreno; N.D. Budinasky; J.R. Scully

    2006-06-23

    Close packed coupled multi-electrodes arrays (MEA) simulating a planar electrode were used to measure the current evolution as a function of position during initiation and propagation of crevice corrosion of AISI 316 stainless steel. Scaling laws derived from polarization data enabled the use of rescaled crevices providing spatial resolution. Crevice corrosion of AISI 316 stainless steel in 0.6 M NaCl at 50 C was found to initiate close to the crevice mouth and to spread inwards with time. The local crevice current density increased dramatically over a short period to reach a limiting value.

  3. Cough & Cold Medicine Abuse

    MedlinePlus

    ... I Help a Friend Who Cuts? Cough & Cold Medicine Abuse KidsHealth > For Teens > Cough & Cold Medicine Abuse ... DXM Why Do People Use Cough and Cold Medicines to Get High? There's an ingredient in many ...

  4. Cold symptoms (image)

    MedlinePlus

    Colds are caused by a virus and can occur year-round. The common cold generally involves a runny nose, nasal congestion, and ... symptoms include sore throat, cough, and headache. A cold usually lasts about 7 days, with perhaps a ...

  5. Colds and flus - antibiotics

    MedlinePlus

    Antibiotics - colds and flu ... treat infections that are caused by a virus. Colds and flu are caused by viruses. If you ... Hamilton A. Treatments for symptoms of the common cold. Am Fam Physician. 2013;88(12):Online. PMID: ...

  6. Vitamin C and colds

    MedlinePlus

    Colds and vitamin C ... belief that vitamin C can cure the common cold , research about this claim is conflicting. Large doses ... vitamin C may help reduce how long a cold lasts, but they do not appear to protect ...

  7. 21 CFR 584.725 - 25-Hydroxyvitamin D3.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false 25-Hydroxyvitamin D3. 584.725 Section 584.725 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE IN FEED...

  8. 21 CFR 584.725 - 25-Hydroxyvitamin D3.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false 25-Hydroxyvitamin D3. 584.725 Section 584.725 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE IN FEED...

  9. 21 CFR 584.725 - 25-Hydroxyvitamin D3.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false 25-Hydroxyvitamin D3. 584.725 Section 584.725 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE IN FEED...

  10. 21 CFR 584.725 - 25-Hydroxyvitamin D3.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false 25-Hydroxyvitamin D3. 584.725 Section 584.725 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE IN FEED...

  11. 21 CFR 584.725 - 25-Hydroxyvitamin D3.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false 25-Hydroxyvitamin D3. 584.725 Section 584.725 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE IN FEED...

  12. Quantum Electrodynamics in d =3 from the ɛ Expansion

    NASA Astrophysics Data System (ADS)

    Di Pietro, Lorenzo; Komargodski, Zohar; Shamir, Itamar; Stamou, Emmanuel

    2016-04-01

    We study quantum electrodynamics in d =3 coupled to Nf flavors of fermions. The theory flows to an IR fixed point for Nf larger than some critical number Nfc. For Nf≤Nfc, chiral-symmetry breaking is believed to take place. In analogy with the Wilson-Fisher description of the critical O (N ) models in d =3 , we make use of the existence of a fixed point in d =4 -2 ɛ to study the three-dimensional conformal theory. We compute, in perturbation theory, the IR dimensions of fermion bilinear and quadrilinear operators. For small Nf, a quadrilinear operator can become relevant in the IR and destabilize the fixed point. Therefore, the epsilon expansion can be used to estimate Nfc. An interesting novelty compared to the O (N ) models is that the theory in d =3 has an enhanced symmetry due to the structure of 3D spinors. We identify the operators in d =4 -2 ɛ that correspond to the additional conserved currents at d =3 and compute their infrared dimensions.

  13. Disruption of nicotine conditioning by dopamine D(3) receptor ligands.

    PubMed

    Le Foll, B; Schwartz, J-C; Sokoloff, P

    2003-02-01

    Tobacco smoking is the first cause of preventable death in modern countries. Nicotine replacement therapy or sustained release bupropion helps smoking cessation, but relapse rates are still very high. Nicotine, like other drugs of abuse, activates the dopamine mesolimbic system, which originates in the ventral tegmental area and projects notably to the nucleus accumbens. Situations or environmental stimuli previously associated with cigarette smoking, for example, smell of cigarette smoke, can elicit craving in abstinent smokers and promote relapse. Reducing the effects of nicotine-associated cues might therefore have potential therapeutic utility for smoking cessation. Such an approach has been validated for cocaine in animals, by using the dopamine D(3) receptor-selective partial agonist BP 897, which inhibits cocaine cue-induced drug-seeking behavior. Here we show that rats repeatedly injected with nicotine in a particular environment develop nicotine-conditioned locomotor responses, accompanied by an increase in D(3) receptor expression in the nucleus accumbens. This conditioned behavior was inhibited by BP 897 or a selective D(3) receptor antagonist, suggesting that antagonizing dopamine selectively at the D(3) receptor disrupts nicotine-conditioned effects and might represent a novel therapeutic approach for smoking cessation. PMID:12610655

  14. Quantum Electrodynamics in d=3 from the ε Expansion.

    PubMed

    Di Pietro, Lorenzo; Komargodski, Zohar; Shamir, Itamar; Stamou, Emmanuel

    2016-04-01

    We study quantum electrodynamics in d=3 coupled to N_{f} flavors of fermions. The theory flows to an IR fixed point for N_{f} larger than some critical number N_{f}^{c}. For N_{f}≤N_{f}^{c}, chiral-symmetry breaking is believed to take place. In analogy with the Wilson-Fisher description of the critical O(N) models in d=3, we make use of the existence of a fixed point in d=4-2ε to study the three-dimensional conformal theory. We compute, in perturbation theory, the IR dimensions of fermion bilinear and quadrilinear operators. For small N_{f}, a quadrilinear operator can become relevant in the IR and destabilize the fixed point. Therefore, the epsilon expansion can be used to estimate N_{f}^{c}. An interesting novelty compared to the O(N) models is that the theory in d=3 has an enhanced symmetry due to the structure of 3D spinors. We identify the operators in d=4-2ε that correspond to the additional conserved currents at d=3 and compute their infrared dimensions. PMID:27081967

  15. Comparative evaluation of laser-assisted micro-milling for AISI 316, AISI 422, TI-6AL-4V and Inconel 718 in a side-cutting configuration

    NASA Astrophysics Data System (ADS)

    Shelton, Jonathan A.; Shin, Yung C.

    2010-07-01

    This paper is focused on numerical modeling and experimental evaluation of laser-assisted micro-milling (LAMM). An experimental setup consisting of a 25 W CO2 laser, three-axis CNC linear stages and a high-speed spindle was used to implement the LAMM process. Micro-endmills between 100 and 300 µm in diameter were used to perform side-cutting operations with and without laser preheat on four materials: AISI 316, AISI 422, Ti-6Al-4V and Inconel 718. A three-dimensional transient finite-volume-based thermal model was used to analytically predict appropriate process parameters on the basis of material-removal temperatures. The effects of LAMM on the machined surface finish, edge burrs, tool wear and workpiece microstructure were evaluated experimentally.

  16. Cold Atoms

    NASA Astrophysics Data System (ADS)

    Bellac, Michel Le

    2014-11-01

    This chapter and the following one address collective effects of quantum particles, that is, the effects which are observed when we put together a large number of identical particles, for example, electrons, helium-4 or rubidium-85 atoms. We shall see that quantum particles can be classified into two categories, bosons and fermions, whose collective behavior is radically different. Bosons have a tendency to pile up in the same quantum state, while fermions have a tendency to avoid each other. We say that bosons and fermions obey two different quantum statistics, the Bose-Einstein and the Fermi-Dirac statistics, respectively. Temperature is a collective effect, and in Section 5.1 we shall explain the concept of absolute temperature and its relation to the average kinetic energy of molecules. We shall describe in Section 5.2 how we can cool atoms down thanks to the Doppler effect, and explain how cold atoms can be used to improve the accuracy of atomic clocks by a factor of about 100. The effects of quantum statistics are prominent at low temperatures, and atom cooling will be used to obtain Bose-Einstein condensates at low enough temperatures, when the atoms are bosons.

  17. Cold energy

    SciTech Connect

    Wallace, John P.

    2015-12-04

    Deviations in Q for resonant superconducting radio frequency niobium accelerator cavities are generally correlated with resistivity loss mechanisms. Field dependent Qs are not well modeled by these classical loss mechanisms, but rather can represent a form of precision cavity surface thermometry. When the field dependent Q variation shows improvement with increasing B field level the classical treatment of this problem is inadequate. To justify this behavior hydrogen as a ubiquitous impurity in niobium, which creates measurable property changes, even at very low concentrations is typically considered the cause of such anomalous behavior. This maybe the case in some instances, but more importantly any system operating with a highly coherent field with a significant time dependent magnetic component at near 2° K will have the ability to organize the remaining free spins within the London penetration depth to form a coupled energy reservoir in the form of low mass spin waves. The niobium resonant cavities are composed of a single isotope with a large nuclear spin. When the other loss mechanisms are stripped away this may be the gain medium activated by the low level residual magnetic fields. It was found that one resonant cavity heat treatment produced optimum surface properties and then functioned as a MASER extracting energy from the 2° K thermal bath while cooling the cavity walls. The cavity operating in this mode is a simulator of what can take place in the wider but not colder universe using the cosmic microwave background (CMB) as a thermal source. The low mass, long lifetimes, and the scale of the magnetic spin waves on the weakly magnetized interstellar medium allows energy to be stored that is many orders of magnitude colder than the cosmic microwave background. A linear accelerator cavity becomes a tool to explore the properties of the long wave length magnetic spin waves that populate this cold low energy regime.

  18. Cold energy

    NASA Astrophysics Data System (ADS)

    Wallace, John P.

    2015-12-01

    Deviations in Q for resonant superconducting radio frequency niobium accelerator cavities are generally correlated with resistivity loss mechanisms. Field dependent Qs are not well modeled by these classical loss mechanisms, but rather can represent a form of precision cavity surface thermometry. When the field dependent Q variation shows improvement with increasing B field level the classical treatment of this problem is inadequate. To justify this behavior hydrogen as a ubiquitous impurity in niobium, which creates measurable property changes, even at very low concentrations is typically considered the cause of such anomalous behavior. This maybe the case in some instances, but more importantly any system operating with a highly coherent field with a significant time dependent magnetic component at near 2° K will have the ability to organize the remaining free spins within the London penetration depth to form a coupled energy reservoir in the form of low mass spin waves. The niobium resonant cavities are composed of a single isotope with a large nuclear spin. When the other loss mechanisms are stripped away this may be the gain medium activated by the low level residual magnetic fields. It was found that one resonant cavity heat treatment produced optimum surface properties and then functioned as a MASER extracting energy from the 2° K thermal bath while cooling the cavity walls. The cavity operating in this mode is a simulator of what can take place in the wider but not colder universe using the cosmic microwave background (CMB) as a thermal source. The low mass, long lifetimes, and the scale of the magnetic spin waves on the weakly magnetized interstellar medium allows energy to be stored that is many orders of magnitude colder than the cosmic microwave background. A linear accelerator cavity becomes a tool to explore the properties of the long wave length magnetic spin waves that populate this cold low energy regime.

  19. A liposomal model that mimics the cutaneous production of vitamin D3. Studies of the mechanism of the membrane-enhanced thermal isomerization of previtamin D3 to vitamin D3

    NASA Technical Reports Server (NTRS)

    Tian, X. Q.; Holick, M. F.

    1999-01-01

    We reported previously that the rate of previtamin D3 (preD3) <==> vitamin D3 isomerization was enhanced by about 10 times in the skin compared with that in organic solvents. To elucidate the mechanism by which the rate of this reaction is enhanced in the skin, we developed a liposomal model that mimicked the enhanced isomerization of preD3 to vitamin D3 that was described in human skin. Using this model we studied the effect of changing the polarity of preD3 as well as changing the chain length and the degree of saturation of liposomal phospholipids on the kinetics of preD3 <==> vitamin D3 isomerization. We found that a decrease in the hydrophilic interaction of the preD3 with liposomal phospholipids by an esterification of the 3beta-hydroxy of preD3 (previtamin D3-3beta-acetate) reduced the rate of the isomerization by 67%. The addition of a hydroxyl on C-25 of the hydrophobic side chain (25-hydroxyprevitamin D3), which decreased the hydrophobic interaction of preD3 with the phospholipids, reduced the rate by 87%. In contrast, in an isotropic n-hexane solution, there was little difference among the rates of the conversion of preD3, its 3beta-acetate, and 25-hydroxy derivatives to their corresponding vitamin D3 compounds. We also determined rate constants (k) of preD3 <==> vitamin D3 isomerization in liposomes containing phosphatidylcholines with different carbon chain lengths. The rates of the reaction were found to be enhanced as the number of carbons (Cn) in the hydrocarbon chain of the phospholipids increased from 10 to 18. In conclusion, these results support our hypothesis that amphipathic interactions between preD3 and membrane phospholipids stabilize preD3 in its "cholesterol like" cZc-conformer, the only conformer of preD3 that can convert to vitamin D3. The stronger these interactions were, the more preD3 was likely in its cZc conformation at any moment and the faster was the rate of its conversion to vitamin D3.

  20. Unification and D3-branes in F-theory

    SciTech Connect

    Heckman, Jonathan J.

    2012-07-27

    A central ingredient in many string based Grand Unified Theories (GUTs) is p-branes filling our spacetime and wrapping some number of internal directions. In this talk we discuss the potential role of D3-branes sitting at a point of the internal geometry in an F-theory GUT. These D3-branes can naturally realize additional superconformal sectors which can couple to the states of the Standard Model. We explain how detailed features of these sectors and their impact on the visible sector can be extracted. Additionally, we explain how in scenarios where the scale of conformal symmetry breaking is close to the weak scale, this extra sector can modify the physics of the Higgs.

  1. The field theory of intersecting D3-branes

    NASA Astrophysics Data System (ADS)

    Mintun, Eric; Polchinski, Joseph; Sun, Sichun

    2015-08-01

    We examine the defect gauge theory on two perpendicular D3-branes with a 1+1 dimensional intersection, consisting of U(1) fields on the D3-branes and charged hypermultiplets on the intersection. We argue that this gauge theory must have a magnetically charged soliton corresponding to the D-string stretched between the branes. We show that the hypermultiplets actually source magnetic as well as electric fields. The magnetic charges are confined if the hypermultiplet action is canonical, but considerations of periodicity of the hypermultiplet space in string theory imply a nontrivial Gibbons-Hawking metric, and we show that there is then the expected magnetic kink solution. The hypermultiplet metric has a singularity, which we argue must be resolved by embedding in the full string theory. Another interesting feature is that the classical field equations have logarithmic divergences at the intersection, which lead to a classical renormalization group flow in the action.

  2. Nonperturbative gluon and ghost propagators in d = 3

    SciTech Connect

    Papavassiliou, Joannis

    2011-05-23

    We study the nonperturbative gluon and ghost propagators in d = 3 Yang-Mills, using the Schwinger-Dyson equations of the pinch technique. The use of the Schwinger mechanism leads to the dynamical generation of a gluon mass, which, in turn, gives rise to an infrared finite gluon propagator and ghost dressing function. The propagators obtained are in very good agreement with the results of SU(2) lattice simulations.

  3. 21 CFR 172.380 - Vitamin D 3.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... accordance with 5 U.S.C. 552(a) and 1 CFR part 51. You may obtain copies from the United States Pharmacopeial.../federal-register/cfr/ibr-locations.html. (c) The additive may be used as follows: (1) At levels not to... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Vitamin D 3. 172.380 Section 172.380 Food...

  4. Role of the D3 dopamine receptor in nicotine sensitization.

    PubMed

    Smith, Laura N; Bachus, Susan E; McDonald, Craig G; Smith, Robert F

    2015-08-01

    Adolescent cigarette use is associated with reduced quitting success and continued smoking in adulthood. Interestingly, polymorphisms of the dopamine D3 receptor (DRD3) gene have been associated with smoking behavior, and the receptor is expressed in an age- and brain region-dependent manner that suggests relevance to addiction. Here, we investigate the possible role of dopamine-related receptors, including DRD3 and an intriguing splice variant known as D3nf, in nicotine-induced sensitization. In adolescent and adult male rats, we examined (1) alterations occurring in dopamine receptor-related mRNAs (DRD1, DRD2, DRD3 and D3nf) at two time points during a sensitizing regimen of nicotine and (2) whether DRD3 antagonism either during the initial treatment (induction) or at a later challenge exposure (expression) is able to block nicotine sensitization. Nicotine-induced changes were seen for DRD3 and D3nf mRNAs in the nucleus accumbens shell early in repeated exposure in both age groups. DRD3 antagonism only blocked the induction of sensitization in adolescents and did not block the expression of sensitization in either age group. Adolescents and adults showed opposite DRD1 mRNA responses to nicotine treatment, while no age- and nicotine-related changes in DRD2 mRNA were observed. These data reveal important age-dependent regulation of DRD1- and DRD3-related mRNAs during the course of nicotine exposure. Furthermore, they highlight a requirement for DRD3 signaling in the development of adolescent nicotine sensitization, suggesting it may represent an appropriate target in the prevention of nicotine dependence initiated at this age. PMID:25907750

  5. Metabolism of 1alpha-hydroxyvitamin D3 by cytochrome P450scc to biologically active 1alpha,20-dihydroxyvitamin D3.

    PubMed

    Tuckey, Robert C; Janjetovic, Zorica; Li, Wei; Nguyen, Minh N; Zmijewski, Michal A; Zjawiony, Jordan; Slominski, Andrzej

    2008-12-01

    Cytochrome P450scc (CYP11A1) metabolizes vitamin D3 to 20-hydroxyvitamin D3 as the major product, with subsequent production of dihydroxy and trihydroxy derivatives. The aim of this study was to determine whether cytochrome P450scc could metabolize 1alpha-hydroxyvitamin D3 and whether products were biologically active. The major product of 1alpha-hydroxyvitamin D3 metabolism by P450scc was identified by mass spectrometry and NMR as 1alpha,20-dihydroxyvitamin D3. Mass spectrometry of minor metabolites revealed the production of another dihydroxyvitamin D3 derivative, two trihydroxy-metabolites made via 1alpha,20-dihydroxyvitamin D3 and a tetrahydroxyvitamin D3 derivative. The Km for 1alpha-hydroxyvitamin D3 determined for P450scc incorporated into phospholipid vesicles was 1.4 mol substrate/mol phospholipid, half that observed for vitamin D3. The kcat was 3.0 mol/min/mol P450scc, 6-fold lower than that for vitamin D3. 1alpha,20-Dihydroxyvitamin D3 inhibited DNA synthesis by human epidermal HaCaT keratinocytes propagated in culture, in a time- and dose-dependent fashion, with a potency similar to that of 1alpha,25-dihydroxyvitamin D3. 1alpha,20-Dihydroxyvitamin D3 (10 microM) enhanced CYP24 mRNA levels in HaCaT keratinocytes but the potency was much lower than that reported for 1alpha,25-dihydroxyvitamin D3. We conclude that the presence of the 1-hydroxyl group in vitamin D3 does not alter the major site of hydroxylation by P450scc which, as for vitamin D3, is at C20. The major product, 1alpha,20-dihydroxyvitamin D3, displays biological activity on keratinocytes and therefore might be useful pharmacologically. PMID:19000766

  6. Barriers to optimizing vitamin D3 intake for the elderly.

    PubMed

    Heaney, Robert P

    2006-04-01

    Available data on metabolic utilization of vitamin D3 indicate a total daily requirement of approximately 4000 international units (iu) (100 microg) or twice the current tolerable upper intake level (UL). In young individuals, most of this comes from the skin. However, cutaneous vitamin D3 synthesis declines with age, creating a need for increasing oral intake to maintain optimal serum 25-hydroxyvitamin D [25(OH)D] concentrations. Estimates of the population distribution of serum 25(OH)D values, coupled with available dose-response data, indicate that it would require input of an additional 2600 iu/d (65 microg/d) of oral vitamin D3 to ensure that 97.5% of older women have 25(OH)D values at or above desirable levels. The age-related decline in cutaneous input, taken together with the UL, creates a substantial barrier to the deployment of public health strategies to optimize vitamin D status in the elderly. PMID:16549492

  7. Dopamine D2/D3 receptor availability and venturesomeness.

    PubMed

    Bernow, Nina; Yakushev, Igor; Landvogt, Christian; Buchholz, Hans-Georg; Smolka, Michael N; Bartenstein, Peter; Lieb, Klaus; Gründer, Gerhard; Vernaleken, Ingo; Schreckenberger, Mathias; Fehr, Christoph

    2011-08-30

    The construct of impulsivity is considered as a major trait of personality. There is growing evidence that the mesolimbic dopamine system plays an important role in the modulation of impulsivity and venturesomeness, the two key components within the impulsivity-construct. The aim of the present study was to explore an association between trait impulsivity measured with self-assessment and the dopaminergic neurotransmission as measured by positron emission tomography (PET) in a cohort of healthy male subjects. In vivo D2/D3 receptor availability was determined with [(18)F]fallypride PET in 18 non-smoking healthy subjects. The character trait impulsivity was measured using the Impulsiveness-Venturesomeness-Empathy questionnaire (I7). Image processing and statistical analysis was performed on a voxel-by-voxel basis using statistical parametric mapping (SPM) software. The I7 subscale venturesomeness correlated positively with the D2/D3 receptor availability within the left temporal cortex and the thalamus. Measures on the I7 subscale impulsiveness and empathy did not correlate with the D2/D3 receptor availability in any brain region investigated. Our results suggest the involvement of extrastriatal dopaminergic neurotransmission in venturesomeness, a component of impulsivity. PMID:21689908

  8. Metabolism of 20-Hydroxyvitamin D3 and 20,23-Dihydroxyvitamin D3 by Rat and Human CYP24A1

    PubMed Central

    Tieu, Elaine W.; Li, Wei; Chen, Jianjun; Kim, Tae-Kang; Ma, Dejian; Slominski, Andrzej T.; Tuckey, Robert C.

    2015-01-01

    CYP11A1 hydroxylates vitamin D3 producing 20S-hydroxyvitamin D3 [20(OH)D3] and 20S,23-dihydroxyvitamin D3 [20,23(OH)2D3] as the major and most characterized metabolites. Both display immuno-regulatory and anti-cancer properties while being non-calcemic. A previous study indicated 20(OH)D3 can be metabolized by rat CYP24A1 to products including 20S,24-dihydroxyvitamin D3 [20,24(OH)2D3] and 20S,25-dihydroxyvitamin D3, with both producing greater inhibition of melanoma colony formation than 20(OH)D3. The aim of this study was to characterize the ability of rat and human CYP24A1 to metabolize 20(OH)D3 and 20,23(OH)2D3. Both isoforms metabolized 20(OH)D3 to the same dihydroxyvitamin D species with no secondary metabolites being observed. Hydroxylation at C24 produced both enantiomers of 20,24(OH)2D3. For rat CYP24A1 the preferred initial site of hydroxylation was at C24 whereas the human enzyme preferred C25. 20,23(OH)2D3 was initially metabolized to 20S,23,24-trihydroxyvitamin D3 and 20S,23,25-trihydroxyvitamin D3 by rat and human CYP24A1 as determined by NMR, with both isoforms showing a preference for initial hydroxylation at C25. CYP24A1 was able to further oxidize these metabolites in a series of reactions which included the cleavage of C23-C24 bond, as indicated by high resolution mass spectrometry of the products, analogous to the catabolism of 1,25(OH)2D3 via the C24-oxidation pathway. Similar catalytic efficiencies were observed for the metabolism of 20(OH)D3 and 20,23(OH)2D3 by human CYP24A1 and were lower than for the metabolism of 1,25(OH)2D3. We conclude that rat and human CYP24A1 metabolizes 20(OH)D3 producing only dihydroxyvitamin D3 species as products which retain biological activity, whereas 20,23(OH)2D3 undergoes multiple oxidations which include cleavage of the side chain. PMID:25727742

  9. Hydroxylation of 20-hydroxyvitamin D3 by human CYP3A4.

    PubMed

    Cheng, Chloe Y S; Slominski, Andrzej T; Tuckey, Robert C

    2016-05-01

    20S-Hydroxyvitamin D3 [20(OH)D3] is the biologically active major product of the action of CYP11A1 on vitamin D3 and is present in human plasma. 20(OH)D3 displays similar therapeutic properties to 1,25-dihydroxyvitamin D3 [1,25(OH)2D3], but without causing hypercalcaemia and therefore has potential for development as a therapeutic drug. CYP24A1, the kidney mitochondrial P450 involved in inactivation of 1,25(OH)2D3, can hydroxylate 20(OH)D3 at C24 and C25, with the products displaying more potent inhibition of melanoma cell proliferation than 20(OH)D3. CYP3A4 is the major drug-metabolising P450 in liver endoplasmic reticulum and can metabolise other active forms of vitamin D, so we examined its ability to metabolise 20(OH)D3. We found that CYP3A4 metabolises 20(OH)D3 to three major products, 20,24R-dihydroxyvitamin D3 [20,24R(OH)2D3], 20,24S-dihydroxyvitamin D3 [20,24S(OH)2D3] and 20,25-dihydroxyvitamin D3 [20,25(OH)2D3]. 20,24R(OH)2D3 and 20,24S(OH)2D3, but not 20,25(OH)2D3, were further metabolised to trihydroxyvitamin D3 products by CYP3A4 but with low catalytic efficiency. The same three primary products, 20,24R(OH)2D3, 20,24S(OH)2D3 and 20,25(OH)2D3, were observed for the metabolism of 20(OH)D3 by human liver microsomes, in which CYP3A4 is a major CYP isoform present. Addition of CYP3A family-specific inhibitors, troleandomycin and azamulin, almost completely inhibited production of 20,24R(OH)2D3, 20,24S(OH)2D3 and 20,25(OH)2D3 by human liver microsomes, further supporting that CYP3A4 plays the major role in 20(OH)D3 metabolism by microsomes. Since both 20,24R(OH)2D3 and 20,25(OH)2D3 have previously been shown to display enhanced biological activity in inhibiting melanoma cell proliferation, our results show that CYP3A4 further activates, rather than inactivates, 20(OH)D3. PMID:26970587

  10. A life study of AISI M-50 and Super Nitralloy spur gears with and without tip relief

    NASA Technical Reports Server (NTRS)

    Townsend, D. P.; Zaretsky, E. V.

    1973-01-01

    Tests were conducted at 170 F with groups of 3.5-in.-pitch-diameter spur gear with and without tip relief made of consumable-electrode vacuum melted (CVM) Spur Nitralloy (5Ni-2Al) and CVM AISI M-50 steel. The AISI M-50 gears without tip relief had lives approximately 50 percent longer than the Super Nitralloy gears without tip relief. However, the Super Nitralloy gears with tip relief had lives equal to the AISI M-50 gears without tip relief. The difference in lives were not statistically significant. All gears failed by classical pitting fatigue at the pitch circle. However, the AIAI M-50 gears with tip relief failed by tooth fracture. AISI M-50 gear sets without tip relief having a spalled gear tooth which were deliberately overrun after spalling had occurred, failed by tooth fracture.

  11. Synthesis and composition of vitamin D-3 metabolites in Solanum malacoxylon.

    PubMed

    Esparza, M S; Vega, M; Boland, R L

    1982-12-17

    The synthesis of vitamin D-3 hydroxylated metabolites in Solanum malacoxylon was investigated. When crude leaf homogenates and subcellular fractions were incubated with [3H]vitamin D-3 and [3H]25-hydroxy-vitamin D-3 under conditions described for animal vitamin D-3-25-hydroxylase and 25-hydroxy-vitamin D-3-1 alpha-hydroxylase, respectively, labelled metabolites identified on the basis of their chromatographic properties as 25-hydroxy-vitamin D-3 and 1,25-dihydroxy-vitamin D-3 were formed. Other unidentified product metabolites were also detected. Vitamin D-3-25-hydroxylase activity was localized in microsomes and 25-hydroxy-vitamin D-3-1 alpha-hydroxylase in mitochondria and microsomes. Chromatography of sterols isolated from leaf extracts preincubated with beta-glucosidase on Sephadex LH-20 columns permitted the isolation of three biologically active fractions with elution properties similar to vitamin D-3, 25-hydroxy-vitamin D-3 and 1,25-dihydroxy-vitamin D-3, respectively. Ultraviolet spectra characteristic of vitamin D-3 and its metabolites were obtained after purification of the fractions by TLC. Co-chromatography of individual fractions with authentic metabolites on TLC provided further evidence that the plant contains vitamin D-3, 25-hydroxy-vitamin D-3 and 1,25-dihydroxy-vitamin D-3 as glucoside derivatives. These results suggest that a similar pathway of vitamin D-3 hydroxylation as in animals may be operative in S. malacoxylon. PMID:6295509

  12. Recent update of the RPLUS2D/3D codes

    NASA Technical Reports Server (NTRS)

    Tsai, Y.-L. Peter

    1991-01-01

    The development of the RPLUS2D/3D codes is summarized. These codes utilize LU algorithms to solve chemical non-equilibrium flows in a body-fitted coordinate system. The motivation behind the development of these codes is the need to numerically predict chemical non-equilibrium flows for the National AeroSpace Plane Program. Recent improvements include vectorization method, blocking algorithms for geometric flexibility, out-of-core storage for large-size problems, and an LU-SW/UP combination for CPU-time efficiency and solution quality.

  13. Transformations of Carbides During Tempering of D3 Tool Steel

    NASA Astrophysics Data System (ADS)

    Nykiel, Tadeusz; Hryniewicz, Tadeusz

    2014-06-01

    The studies were performed on D3 tool steel hardened after austenitizing at 1050 °C during 30 min and tempering at 200-700 °C. Based on the diffraction studies performed from the extraction replicas, using electron microscopy, it was found that after 120-min tempering in the consecutive temperatures, the following types of carbides occur: Apart from higher mentioned carbides, there are also big primary carbides and fine secondary M7C3 carbides occurring, which did not dissolve during austenitizing.

  14. Non-perturbative effects on a fractional D3-brane

    NASA Astrophysics Data System (ADS)

    Ferretti, Gabriele; Petersson, Christoffer

    2009-03-01

    In this note we study the Script N = 1 abelian gauge theory on the world volume of a single fractional D3-brane. In the limit where gravitational interactions are not completely decoupled we find that a superpotential and a fermionic bilinear condensate are generated by a D-brane instanton effect. A related situation arises for an isolated cycle invariant under an orientifold projection, even in the absence of any gauge theory brane. Moreover, in presence of supersymmetry breaking background fluxes, such instanton configurations induce new couplings in the 4-dimensional effective action, including non-perturbative contributions to the cosmological constant and non-supersymmetric mass terms.

  15. Recombination of H(3+) and D(3+) ions with electrons

    NASA Technical Reports Server (NTRS)

    Johnsen, R.; Gougousi, T.; Golde, M. F.

    1994-01-01

    Flowing-afterglow measurements in decaying H3(+) or D3(+) plasmas suggest that de-ionization does not occur by simple binary recombination of a single ion species. We find that vibrational excitation of the ions fails to provide an explanation for the effect, contrary to an earlier suggestion. Instead, we suggest that collisional stabilization of H3** Rydberg molecules by ambient electrons introduces an additional dependence on electron density. The proposed mechanism would permit plasma de-ionization to occur without the need for dissociative recombination by the mechanism of potential-surface crossings.

  16. Assessment of XM-19 as a Substitute for AISI 348 in ATR Service

    SciTech Connect

    F. A. Garner; L. R. Greenwood; R. E. Mizia; C. R. Tyler

    2007-11-01

    It has been proposed that XM-19 alloy be considered as a possible replacement steel for AISI 348 in the construction of Advanced Test Reactor (ATR) capsules. AISI 348 works well, but is currently very difficult to obtain commercially. The superior and desirable mechanical properties of XM-19 alloy have been proven in non-nuclear applications, but no data are available regarding its use in radiation environments. While most 300 series alloys will meet the conditions required in ATR , it cannot be confidently assumed that XM-19 can be substituted without prior qualification in a radiation test. Compared to AISI 348, XM-19 will have an enhanced tendency for phase instabilities due to its higher levels of Ni and, especially, Si. However, transmutation of important elemental components in the highly thermalized ATR spectrum may have a very pronounced effect on its performance during irradiation. Not only will strong transmutation of Mn to Fe reduce the ductility and strength advantages provided by the higher initial Mn content of XM-19, but the extensive loss of Mn will also release from solution much of the N upon which the higher strength of XM-19 depends. In addition, the combined influence of transmutation and Inverse Kirkendall processes may lead to gas-bubble-covered grain boundaries, producing a very fragile alloy after significant irradiation has accumulated. At present, there are no radiation data available to substantiate this possible scenario. An alternate proposal is therefore advanced. Since the response of AISI 348 and 347 to radiation are expected to be relatively indistinguishable, the AISI 347 might serve as an acceptable replacement. While AISI 348 is usually chosen for nuclear service in order to reduce the overall radioactivity arising from relatively small amounts of highly transmutable elements such as cobalt, these elements have very little effect on the radiation performance of the steel. In the proposed application, however, the activity

  17. Compatibility between AISI441 alloy interconnect and representative seal glasses in solid oxide fuel/electrolyzer cells

    NASA Astrophysics Data System (ADS)

    Jin, T.; Lu, K.

    AISI441 alloy, an advanced ferritic stainless steel, is considered as a promising metallic interconnect material for solid oxide fuel/electrolyzer cells. In this work, the compatibility between the AISI441 alloy and four representative seal glasses (YSO-4, G18, SABS-0, and SCAN2) has been studied. The AISI441/glass couples are thermally treated in both air and H 2/H 2O atmospheres at 800 °C for up to 500 h. Interfacial morphology shows that the YSO-4 glass and the SCAN2 glass have relatively high reaction tendency with the AISI441 alloy; the G18 glass devitrifies extensively during the thermal treatment; and the SABS-0 glass shows very little interaction or devitrification. In the H 2/H 2O atmosphere, the AISI441 alloy has less interaction with the sealing glasses compared with the air condition. Different phases from interfacial reaction and devitrification have been identified for each of the sealing glasses. Diffusion, devitrification, and reaction are the events occurring at the interface. Overall, the AISI441/SABS-0 glass couple shows the least interfacial reaction and devitrification and the best thermal stability.

  18. The dopamine D3 receptor gene and posttraumatic stress disorder.

    PubMed

    Wolf, Erika J; Mitchell, Karen S; Logue, Mark W; Baldwin, Clinton T; Reardon, Annemarie F; Aiello, Alison; Galea, Sandro; Koenen, Karestan C; Uddin, Monica; Wildman, Derek; Miller, Mark W

    2014-08-01

    The dopamine D3 receptor (DRD3) gene has been implicated in schizophrenia, autism, and substance use-disorders and is related to emotion reactivity, executive functioning, and stress-responding, processes impaired in posttraumatic stress disorder (PTSD). The aim of this candidate gene study was to evaluate DRD3 polymorphisms for association with PTSD. The discovery sample was trauma-exposed White, non-Hispanic U.S. veterans and their trauma-exposed intimate partners (N = 491); 60.3% met criteria for lifetime PTSD. The replication sample was 601 trauma-exposed African American participants living in Detroit, Michigan; 23.6% met criteria for lifetime PTSD. Genotyping was based on high-density bead chips. In the discovery sample, 4 single nucleotide polymorphisms (SNPs), rs2134655, rs201252087, rs4646996, and rs9868039, showed evidence of association with PTSD and withstood correction for multiple testing. The minor alleles were associated with reduced risk for PTSD (OR range = 0.59 to 0.69). In the replication sample, rs2251177, located 149 base pairs away from the most significant SNP in the discovery sample, was nominally associated with PTSD in men (OR = 0.32). Although the precise role of the D3 receptor in PTSD is not yet known, its role in executive functioning and emotional reactivity, and the sensitivity of the dopamine system to environmental stressors could potentially explain this association. PMID:25158632

  19. The Dopamine D3 Receptor Gene and Posttraumatic Stress Disorder

    PubMed Central

    Wolf, Erika J.; Mitchell, Karen S.; Logue, Mark W.; Baldwin, Clinton T.; Reardon, Annemarie F.; Aiello, Alison; Galea, Sandro; Koenen, Karestan C.; Uddin, Monica; Wildman, Derek; Miller, Mark W.

    2014-01-01

    The dopamine D3 receptor (DRD3) gene has been implicated in schizophrenia, autism, and substance use-disorders and is related to emotion reactivity, executive functioning, and stress-responding, processes impaired in posttraumatic stress disorder (PTSD). This aim of this candidate gene study was to evaluate DRD3 polymorphisms for association with PTSD. The discovery sample was trauma-exposed white, non-Hispanic veterans and their trauma-exposed intimate partners (N = 491); 60% met criteria for lifetime PTSD. The replication sample was 601 trauma-exposed African American participants; 24% met criteria for lifetime PTSD. Genotyping was based on high-density bead chips. In the discovery sample, four single nucleotide polymorphisms (SNPs), rs2134655, rs201252087, rs4646996, and rs9868039, showed evidence of association with PTSD and withstood correction for multiple testing. The minor alleles were associated with reduced risk for PTSD (odds ratio range: 0.59 – 0.69). In the replication sample, rs2251177, located 149 base pairs away from the most significant SNP in the discovery sample, was nominally associated with PTSD in men (odds ratio: 0.32). Although the precise role of the D3 receptor in PTSD is not yet known, its role in executive functioning and emotional reactivity, and the sensitivity of the dopamine system to environmental stressors, could potentially explain this association. PMID:25158632

  20. 750 GeV diphotons from a D3-brane

    NASA Astrophysics Data System (ADS)

    Heckman, Jonathan J.

    2016-05-01

    Motivated by the recently reported diphoton excess at 750 GeV observed by both CMS and ATLAS, we study string-based particle physics models which can accommodate this signal. Quite remarkably, although Grand Unified Theories in F-theory tend to impose tight restrictions on candidate extra sectors, the case of a probe D3-brane near an E-type Yukawa point naturally leads to a class of strongly coupled models capable of accommodating the observed signature. In these models, the visible sector is realized by intersecting 7-branes, and the 750 GeV resonance is a scalar modulus associated with motion of the D3-brane in the direction transverse to the Standard Model 7-branes. Integrating out heavy 3-7 string messenger states leads to dimension five operators for gluon fusion production and diphoton decays. Due to the unified structure of interactions, these models also predict that there should be additional decay channels to ZZ and Zγ. We also comment on models with distorted unification, where both the production mechanism and decay channels can differ.

  1. Evidence for triangular D3h symmetry in 12C.

    PubMed

    Marín-Lámbarri, D J; Bijker, R; Freer, M; Gai, M; Kokalova, Tz; Parker, D J; Wheldon, C

    2014-07-01

    We report a measurement of a new high spin Jπ=5- state at 22.4(2) MeV in 12C which fits very well to the predicted (ground state) rotational band of an oblate equilateral triangular spinning top with a D3h symmetry characterized by the sequence 0+, 2+, 3-, 4±, 5- with almost degenerate 4+ and 4- (parity doublet) states. Such a D3h symmetry was observed in triatomic molecules, and it is observed here for the first time in nuclear physics. We discuss a classification of other rotation-vibration bands in 12C such as the (0+) Hoyle band and the (1-) bending mode band and suggest measurements in search of the predicted ("missing") states that may shed new light on clustering in 12C and light nuclei. In particular, the observation (or nonobservation) of the predicted ("missing") states in the Hoyle band will allow us to conclude the geometrical arrangement of the three alpha particles composing the Hoyle state at 7.654 MeV in 12C. PMID:25032922

  2. Cold Stress and the Cold Pressor Test

    ERIC Educational Resources Information Center

    Silverthorn, Dee U.; Michael, Joel

    2013-01-01

    Temperature and other environmental stressors are known to affect blood pressure and heart rate. In this activity, students perform the cold pressor test, demonstrating increased blood pressure during a 1- to 2-min immersion of one hand in ice water. The cold pressor test is used clinically to evaluate autonomic and left ventricular function. This…

  3. 16 CFR Appendix D3 to Part 305 - Water Heaters-Oil

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... RULEâ) Pt. 305, App. D3 Appendix D3 to Part 305—Water Heaters—Oil Range Information Capacity First hour... 16 Commercial Practices 1 2014-01-01 2014-01-01 false Water Heaters-Oil D3 Appendix D3 to Part 305 Commercial Practices FEDERAL TRADE COMMISSION REGULATIONS UNDER SPECIFIC ACTS OF CONGRESS ENERGY AND...

  4. 16 CFR Appendix D3 to Part 305 - Water Heaters-Oil

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 16 Commercial Practices 1 2013-01-01 2013-01-01 false Water Heaters-Oil D3 Appendix D3 to Part 305... DISCLOSURES REGARDING ENERGY CONSUMPTION AND WATER USE OF CERTAIN HOME APPLIANCES AND OTHER PRODUCTS REQUIRED UNDER THE ENERGY POLICY AND CONSERVATION ACT (âAPPLIANCE LABELING RULEâ) Pt. 305, App. D3 Appendix D3...

  5. Cold and Cough Medicines

    MedlinePlus

    ... What can you do for your cold or cough symptoms? Besides drinking lots of fluids and getting ... medicines. There are lots of different cold and cough medicines, and they do different things. Nasal decongestants - ...

  6. Cold knife cone biopsy

    MedlinePlus

    A cold knife cone biopsy (conization) is surgery to remove a sample of abnormal tissue from the cervix. The ... Cold knife cone biopsy is done to detect cervical cancer or early changes that lead to cancer. ...

  7. Cold wave lotion poisoning

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/002693.htm Cold wave lotion poisoning To use the sharing features on this page, please enable JavaScript. Cold wave lotion is a hair care product used ...

  8. Cold knife cone biopsy

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/003910.htm Cold knife cone biopsy To use the sharing features on this page, please enable JavaScript. A cold knife cone biopsy (conization) is surgery to remove ...

  9. Cold Sores (Orofacial Herpes)

    MedlinePlus

    ... rash and rashes clinical tools newsletter | contact Share | Cold Sores (Orofacial Herpes) Information for adults A A ... face, known as orofacial herpes simplex, herpes labialis, cold sores, or fever blisters, is a common, recurrent ...

  10. Cold and Cough Medicines

    MedlinePlus

    ... What can you do for your cold or cough symptoms? Besides drinking plenty of fluids and getting ... medicines. There are lots of different cold and cough medicines, and they do different things. Nasal decongestants - ...

  11. Determination of tribological properties of ion-nitrided AISI 5140 steel

    SciTech Connect

    Alsaran, Akguen

    2002-09-15

    AISI 5140 low-alloy steel is ion-nitrided under different process parameters, including time (1, 4, and 8 h), temperature (450, 500, and 550 deg. C), and various gas mixtures at a working pressure of 5 mbar. The ion-nitriding behaviors of AISI 5140 steel have been assessed by evaluating tribological properties, surface hardness, surface roughness, compound layer thickness, and case depth by using a pin-on-disk wear machine, microhardness tester, surface profilometer, and scanning electron microscopy (SEM). It is found that ion nitriding improves the wear rate, and the presence of a hard and brittle compound layer on the surface causes an increase in wear of specimen surface. It is finally observed that ion nitriding parameters have no dominant effect on the friction coefficient.

  12. Experimental Investigation of the Effect of Burnishing Force on Service Properties of AISI 1010 Steel Plates

    NASA Astrophysics Data System (ADS)

    Gharbi, F.; Sghaier, S.; Morel, F.; Benameur, T.

    2015-02-01

    This paper presents the results obtained with a new ball burnishing tool developed for the mechanical treatment of large flat surfaces. Several parameters can affect the mechanical behavior and fatigue of workpiece. Our study focused on the effect of the burnishing force on the surface quality and on the service properties (mechanical behavior, fatigue) of AISI 1010 steel hot-rolled plates. Experimental results assert that burnishing force not exceeding 300 N causes an increase in the ductility. In addition, results indicated that the effect of the burnishing force on the residual surface stress was greater in the direction of advance than in the cross-feed direction. Furthermore, the flat burnishing surfaces did not improve the fatigue strength of AISI 1010 steel flat specimens.

  13. Rolling-element fatigue life of AISI M-50 and 18-4-1 balls

    NASA Technical Reports Server (NTRS)

    Parker, R. J.; Zaretsky, E. V.

    1978-01-01

    Rolling element fatigue studies were conducted with AISI M-50, EFR 18-4-1, and VAR 18-4-1. Groups of 12.7 mm (1/2-in) diameter balls of each material were tested in the five ball fatigue tester. Test conditions included a load of 1540 N (347 lbf) giving a maximum Hertz stress of 5520 MPa (800 000 psi), a shaft speed of 10,700 rpm, and a contact angle of 30 deg. Tests were run at a race temperature of 339 K (150 F) with a type 2 ester lubricant. The rolling element fatigue life of AISI M-50 was not significantly different from that of EFR 18-4-1 or VAR 18-4-1 based on a statistical comparison of the test results.

  14. Effects of various gas mixtures on plasma nitriding behavior of AISI 5140 steel

    SciTech Connect

    Karakan, Mehmet; Alsaran, Akguen; Celik, Ayhan

    2002-10-15

    AISI 5140 steel was plasma nitrided at various gas mixtures of nitrogen, hydrogen, and argon to investigate the actions of hydrogen and argon on plasma nitriding. The structural and mechanical properties of ion-nitrided AISI 5140 steel have been assessed by evaluating composition of phases, surface hardness, compound layer thickness, and case depth by using X-ray diffraction (XRD), microhardness tests, and scanning electron microscopy (SEM). It was found that the growth of compound layer can be controlled and the diffusion improved when the gas mixture includes H{sub 2} gas. Additionally, it was determined that the amount of Ar in dual gas mixture must be at 20% minimum to obtain distinctive surface hardness and compound layer thickness.

  15. An investigation of the plastic fracture of AISI 4340 and 18 nickel - 200 grade maraging steels

    NASA Technical Reports Server (NTRS)

    Cox, T. B.; Low, J. R., Jr.

    1974-01-01

    The mechanisms of plastic fracture (dimpled rupture) in high-purity and commercial 18 Ni, 200 grade maraging steels and quenched and tempered AISI 4340 steels have been studied. Plastic fracture takes place in the maraging alloys through void initiation by fracture of titanium carbo-nitride inclusions and the growth of these voids until impingement results in coalescence and final fracture. The fracture of AISI 4340 steel at a yield strength of 200 ksi occurs by nucleation and subsequent growth of voids formed by fracture of the interface between manganese sulfide inclusions and the matrix. The growth of these inclusion-nucleated voids is interrupted long before coalescence by impingement, by the formation of void sheets which connect neighboring sulfide-nucleated voids.

  16. Regulation of Mycobacterium-specific mononuclear cell responses by 25-hydroxyvitamin D3

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The active vitamin D metabolite, 1,25-dihydroxyvitamin D3 (1,25[OH]2D3), has been shown to be an important regulator of innate and adaptive immune function. In addition, synthesis of 1,25(OH)2D3 from 25-hydroxyvitamin D3 (25[OH]D3) by the enzyme 1alpha-hydroxylase in monocytes upon activation by TLR...

  17. Interactive initialization of 2D/3D rigid registration

    SciTech Connect

    Gong, Ren Hui; Güler, Özgür; Kürklüoglu, Mustafa; Lovejoy, John; Yaniv, Ziv

    2013-12-15

    Purpose: Registration is one of the key technical components in an image-guided navigation system. A large number of 2D/3D registration algorithms have been previously proposed, but have not been able to transition into clinical practice. The authors identify the primary reason for the lack of adoption with the prerequisite for a sufficiently accurate initial transformation, mean target registration error of about 10 mm or less. In this paper, the authors present two interactive initialization approaches that provide the desired accuracy for x-ray/MR and x-ray/CT registration in the operating room setting. Methods: The authors have developed two interactive registration methods based on visual alignment of a preoperative image, MR, or CT to intraoperative x-rays. In the first approach, the operator uses a gesture based interface to align a volume rendering of the preoperative image to multiple x-rays. The second approach uses a tracked tool available as part of a navigation system. Preoperatively, a virtual replica of the tool is positioned next to the anatomical structures visible in the volumetric data. Intraoperatively, the physical tool is positioned in a similar manner and subsequently used to align a volume rendering to the x-ray images using an augmented reality (AR) approach. Both methods were assessed using three publicly available reference data sets for 2D/3D registration evaluation. Results: In the authors' experiments, the authors show that for x-ray/MR registration, the gesture based method resulted in a mean target registration error (mTRE) of 9.3 ± 5.0 mm with an average interaction time of 146.3 ± 73.0 s, and the AR-based method had mTREs of 7.2 ± 3.2 mm with interaction times of 44 ± 32 s. For x-ray/CT registration, the gesture based method resulted in a mTRE of 7.4 ± 5.0 mm with an average interaction time of 132.1 ± 66.4 s, and the AR-based method had mTREs of 8.3 ± 5.0 mm with interaction times of 58 ± 52 s. Conclusions: Based on the

  18. Exercising in Cold Weather

    MedlinePlus

    ... www.nia.nih.gov/Go4Life Exercising in Cold Weather Exercise has benefits all year, even during winter. ... activities when it’s cold outside: l Check the weather forecast. If it’s very windy or cold, exercise ...

  19. Effects of Ce on Inclusions, Microstructure, Mechanical Properties, and Corrosion Behavior of AISI 202 Stainless Steel

    NASA Astrophysics Data System (ADS)

    Cai, Guojun; Li, Changsheng

    2015-10-01

    The sizes and morphologies of nonmetallic inclusions, microhardness, tensile strength, and Charpy impact toughness in AISI 202 stainless steel with different Ce contents were synthetically analyzed by means of SEM, TEM, microhardness tester, and tensile and Charpy impact tests. Effects of Ce addition on the corrosion behavior were investigated in 5 wt.% H2SO4 solution for different periods of time through measuring AC impedance. The EIS measurements indicate that the steels with Ce addition exhibit higher R p values than those without Ce, which illustrates the relative resistance to uniform corrosion is accompanied by an increasing Ce addition. Ce addition to AISI 202 stainless steel improves its uniform corrosion resistance owing to metamorphic inclusions and the improvement of electrode potential in matrix. Upon increasing Ce addition, the indentation morphology of samples transfers from sink-in types to pile-up types, explaining good machinability of steels containing Ce. It is witnessed from the fracture mode that Ce refines the grain size of steels, significantly increasing the strength; in the meantime, its plasticity is improved, thereby solving the contradiction between the strength and the plasticity of steels. It is concluded that AISI 202 stainless steel with 0.016 wt.% Ce addition in the mass fraction has the best mechanical properties and the uniform corrosion resistance.

  20. Stoichiometric titanium dioxide ion implantation in AISI 304 stainless steel for corrosion protection

    NASA Astrophysics Data System (ADS)

    Hartwig, A.; Decker, M.; Klein, O.; Karl, H.

    2015-12-01

    The aim of this study is to evaluate the applicability of highly chemically inert titanium dioxide synthesized by ion beam implantation for corrosion protection of AISI 304 stainless steel in sodium chloride solution. More specifically, the prevention of galvanic corrosion between carbon-fiber reinforced plastic (CFRP) and AISI 304 was investigated. Corrosion performance of TiO2 implanted AISI 304 - examined for different implantation and annealing parameters - is strongly influenced by implantation fluence. Experimental results show that a fluence of 5 × 1016 cm-2 (Ti+) and 1 × 1017 cm-2 (O+) is sufficient to prevent pitting corrosion significantly, while galvanic corrosion with CFRP can already be noticeably reduced by an implantation fluence of 5 × 1015 cm-2 (Ti+) and 1 × 1016 cm-2 (O+). Surface roughness, implantation energy and annealing at 200 °C and 400 °C show only little influence on the corrosion behavior. TEM analysis indicates the existence of stoichiometric TiO2 inside the steel matrix for medium fluences and the formation of a separated metal oxide layer for high fluences.

  1. Experimental investigation of wear characteristics on TiCN-coated AISI 410 steel

    NASA Astrophysics Data System (ADS)

    Prabakaran, Vijayasarathi; Sivakumaran, Ilaiyavel; Palimar, Suresh Prabhu

    2016-04-01

    In this work, the dry sliding wear test of uncoated and multilayer TiCN-coated AISI 410 steel against high carbon steel disc recognized at 2.30267 ms-1 sliding speeds and under a three series load of 5, 10 and 20 N at room temperature. On account of the more coherent interface between TiCN and C probably found, there are high hardness and superior wear resistance. Compared to AISI 410 uncoated steel, the presence of C in the multilayer TiCN coatings leads to reduced coefficient of friction and wear loss. The multilayer TiCN coating is characterized by X-ray diffraction analysis, scanning electron microscopy, micro-hardness and pin-on-disc tribometer tests. The more grooving region, pits and ploughing ridge were examined on the worn surface of the AISI 410 uncoated steel. The result shows hard multilayer TiCN-coated particles viewing on the worn surface of the high carbon steel disc.

  2. Direct energy conversion system for D(3)-He fusion

    NASA Astrophysics Data System (ADS)

    Tomita, Y.; Shu, L. Y.; Momota, H.

    1993-11-01

    A novel and highly efficient direct energy conversion system is proposed for utilizing D(3)-He fueled fusion. In order to convert kinetic energy of ions, we applied a pair of direct energy conversion systems each of which has a cusp-type DEC and a traveling wave DEC (TWDEC). In a cusp-type DEC, electrons are separated from the escaping ions at the first line-cusp and the energy of thermal ion components is converted at the second cusp DEC. The fusion protons go through the cusp-type DEC and arrive at the TWDEC, which principle is similar to 'LINAC'. The energy of fusion protons is recovered to electricity with an efficiency of more than 70%. These DEC's bring about the high efficient fusion plant.

  3. Cold Fronts in Cold Dark Matter Clusters

    NASA Astrophysics Data System (ADS)

    Nagai, Daisuke; Kravtsov, Andrey V.

    2003-04-01

    Recently, high-resolution Chandra observations revealed the existence of very sharp features in the X-ray surface brightness and temperature maps of several clusters. These features, called cold fronts, are characterized by an increase in surface brightness by a factor >~2 over 10-50 kpc accompanied by a drop in temperature of a similar magnitude. The existence of such sharp gradients can be used to put interesting constraints on the physics of the intracluster medium (ICM) if their mechanism and longevity are well understood. Here, we present results of a search for cold fronts in high-resolution simulations of galaxy clusters in cold dark matter models. We show that sharp gradients with properties similar to those of observed cold fronts naturally arise in cluster mergers when the shocks heat gas surrounding the merging subcluster, while its dense core remains relatively cold. The compression induced by supersonic motions and shock heating during the merger enhance the amplitude of gas density and temperature gradients across the front. Our results indicate that cold fronts are nonequilibrium transient phenomena and can be observed for a period of less than a billion years. We show that the velocity and density fields of gas surrounding the cold front can be very irregular, which would complicate analyses aiming to put constraints on the physical conditions of the ICM in the vicinity of the front.

  4. Fully automated 2D-3D registration and verification.

    PubMed

    Varnavas, Andreas; Carrell, Tom; Penney, Graeme

    2015-12-01

    Clinical application of 2D-3D registration technology often requires a significant amount of human interaction during initialisation and result verification. This is one of the main barriers to more widespread clinical use of this technology. We propose novel techniques for automated initial pose estimation of the 3D data and verification of the registration result, and show how these techniques can be combined to enable fully automated 2D-3D registration, particularly in the case of a vertebra based system. The initialisation method is based on preoperative computation of 2D templates over a wide range of 3D poses. These templates are used to apply the Generalised Hough Transform to the intraoperative 2D image and the sought 3D pose is selected with the combined use of the generated accumulator arrays and a Gradient Difference Similarity Measure. On the verification side, two algorithms are proposed: one using normalised features based on the similarity value and the other based on the pose agreement between multiple vertebra based registrations. The proposed methods are employed here for CT to fluoroscopy registration and are trained and tested with data from 31 clinical procedures with 417 low dose, i.e. low quality, high noise interventional fluoroscopy images. When similarity value based verification is used, the fully automated system achieves a 95.73% correct registration rate, whereas a no registration result is produced for the remaining 4.27% of cases (i.e. incorrect registration rate is 0%). The system also automatically detects input images outside its operating range. PMID:26387052

  5. A study on the control of melting ratio to increase mechanical properties of laser welded joints between AISI 440C and AISI 430F

    NASA Astrophysics Data System (ADS)

    Romoli, L.; Rashed, C. A. A.; Lovicu, G.; Ishak, R.

    2015-05-01

    Laser beam welding of dissimilar AISI 440C and AISI 430F stainless steels was investigated in a circular constrained configuration. The beam incidence angle and the offset of the focusing position respect to the contact point between the two materials were used as main control parameters to vary the melting ratio inside the seam. The objective of the study is twofold: to avoid surface microcracks related to the high percentage of carbon of the martensitic steel and to enhance the shear strength of the weld by making it less brittle. To reach this scope the effects of incidence angle and offset on weld bead geometry and melting ratio were studied by means of metallographic analyses, microstructure and microhardness characterization. As last step, the weld mechanical strength was tested by tensile-shear stress test on the whole seam. Experiments demonstrated that varying incidence angle and offsetting the focal position is a reliable method to modify the melting ratio and maintaining the expected resistance length at the material interface, as well. It was found that increasing the percentage of ferritic steel into the joint has beneficial effects on the weld quality and on the shear resistance. The critical carbon content determining the mechanical properties in the fusion zone can be calculated by taking into account the melting ratio.

  6. Cough and Cold Medicine Abuse

    MedlinePlus

    ... and Cold Medicine Abuse DrugFacts: Cough and Cold Medicine Abuse Email Facebook Twitter Revised May 2014 Some ... diverted for abuse. How Are Cough and Cold Medicines Abused? Cough and cold medicines are usually consumed ...

  7. The use of vitamin D3 and its metabolites to improve beef tenderness.

    PubMed

    Foote, M R; Horst, R L; Huff-Lonergan, E J; Trenkle, A H; Parrish, F C; Beitz, D C

    2004-01-01

    Three experiments were conducted to determine whether feeding 25-hydroxyvitamin D3 (25-OH D3) or 1,25-dihydroxyvitamin D3 (1,25-(OH)2 D3) improves the tenderness of longissimus dorsi (LD), semimembranosus (SM), and infraspinatus (IF) muscles similar to supplemental vitamin D3 without leaving residual vitamin D3 and its metabolites in muscle. In the first two experiments, 24 crossbred steers were used to determine the effects of different oral amounts of 1,25-(OH)2 D3 (Exp. 1; n = 12) and 25-OH D3 (Exp. 2; n = 12) on plasma Ca2+ concentrations. In the third experiment, crossbred steers were allotted randomly to one of four treatments: 1) control placebo (n = 7); 2) 5 x 10(6) IU of vitamin D3/d (n = 9) for 9 d and harvested 2 d after last treatment; 3) single, 125-mg dose of 25-OH D3 (n = 8) 4 d before harvest; or 4) single, 500-microg dose of 1,25-(OH)2 D3 (n = 9) 3 d before harvest. The LD and SM steaks from each animal were aged for 8, 14, or 21 d, whereas steaks from the IF were aged for 14 or 21 d. All steaks were analyzed for tenderness by Warner-Bratzler shear force and for troponin-T degradation by Western blot analysis. Supplementing steers with vitamin D3 increased (P < 0.01) the concentration of vitamin D3 and 25-OH D3 in all muscles sampled. Feeding steers 25-OH D3 increased (P < 0.05) the concentration of 25-OH D3 in meat, but to an amount less than half that of cattle treated with vitamin D3. Supplemental 1,25-(OH)2 D3 did not affect (P < 0.10) shear force values; however, there was a trend (P < 0.10) for supplemental vitamin D3 and 25-OH D3 to produce LD steaks with lower shear values after 8 and 14 d of aging, and lower (P < 0.10) shear force values for the SM aged for 21 d. Analysis of Western blots indicated that LD steaks from cattle supplemented with vitamin D3 and 25-OH D3 had greater (P < 0.05) troponin-T degradation. Antemortem supplementation of 25-OH D3 seems to increase postmortem proteolysis and tenderness in the LD and SM without

  8. Anti-proliferative activity of 25-hydroxyvitamin D3 in human prostate cells.

    PubMed

    Munetsuna, Eiji; Kawanami, Rie; Nishikawa, Miyu; Ikeda, Shinnosuke; Nakabayashi, Sachie; Yasuda, Kaori; Ohta, Miho; Kamakura, Masaki; Ikushiro, Shinichi; Sakaki, Toshiyuki

    2014-02-15

    1α-Hydroxylation of 25-hydroxyvitamin D3 is believed to be essential for its biological effects. In this study, we evaluated the biological activity of 25(OH)D3 itself comparing with the effect of cell-derived 1α,25-dihydroxyvitamin D3 (1α,25(OH)2D3). First, we measured the cell-derived 1α,25(OH)2D3 level in immortalized human prostate cell (PZ-HPV-7) using [(3)H]-25(OH)D3. The effects of the cell-derived 1α,25(OH)2D3 on vitamin D3 24-hydroxylase (CYP24A1) mRNA level and the cell growth inhibition were significantly lower than the effects of 25(OH)D3 itself added to cell culture. 25-Hydroxyvitamin D3 1α-hydroxylase (CYP27B1) gene knockdown had no significant effects on the 25(OH)D3-dependent effects, whereas vitamin D receptor (VDR) gene knockdown resulted in a significant decrease in the 25(OH)D3-dependent effects. These results strongly suggest that 25(OH)D3 can directly bind to VDR and exerts its biological functions. DNA microarray and real-time RT-PCR analyses suggest that semaphorin 3B, cystatin E/M, and cystatin D may be involved in the antiproliferative effect of 25(OH)D3. PMID:24291609

  9. Why Being Cold Might Foster a Cold

    MedlinePlus

    ... These cells produce essential immune system proteins called interferons that respond to a cold virus. The cells ... several degrees below core body temperature, virus-fighting interferons were less able to do their job. The ...

  10. Comparative effects of 1α-hydroxyvitamin D3 and 1,25-dihydroxyvitamin D3 on transporters and enzymes in fxr(+/+) and fxr(-/-) mice.

    PubMed

    Chow, Edwin C Y; Durk, Matthew R; Maeng, Han-Joo; Pang, K Sandy

    2013-10-01

    Previous studies have shown that 1α,25-dihydroxyvitamin D3 [1,25(OH)2 D3 ] treatment in mice resulted in induction of intestinal and renal Cyp24a1 and Trpv6 expression, increased hepatic Cyp7a1 expression and activity, as well as higher renal Mdr1/P-gp expression. The present study compared the equimolar efficacies of 1α-hydroxyvitamin D3 [1α(OH)D3 ] (6 nmol/kg i.p. q2d × 4), a lipophilic precursor with a longer plasma half-life that is converted to 1,25(OH)2 D3 , and 1,25(OH)2 D3 on vitamin D receptor (VDR) target genes. To clarify whether changes in VDR genes was due to VDR and not secondary, farnesoid X receptor (FXR)-directed effects, namely, lower Cyp7a1 expression in rat liver due to increased bile acid absorption, wildtype [fxr(+/+)] and FXR knockout [fxr(-/-)] mice were used to distinguish between VDR and FXR effects. With the exception that hepatic Sult2a1 mRNA was increased equally well by 1α(OH)D3 and 1,25(OH)2 D3 , 1α(OH)D3 treatment led to higher increases in hepatic Cyp7a1, renal Cyp24a1, VDR, Mdr1 and Mrp4, and intestinal Cyp24a1 and Trpv6 mRNA expression in both fxr(+/+) and fxr(-/-) mice compared to 1,25(OH)2 D3 treatment. A similar induction in protein expression and microsomal activity of hepatic Cyp7a1 and renal P-gp and Mrp4 protein expression was noted for both compounds. A higher intestinal induction of Trpv6 was observed, resulting in greater hypercalcemic effect following 1α(OH)D3 treatment. The higher activity of 1α(OH)D3 was explained by its rapid conversion to 1,25(OH)2 D3 in tissue sites, furnishing higher plasma and tissue 1,25(OH)2 D3 levels compared to following 1,25(OH)2 D3 -treatment. In conclusion, 1α(OH)D3 exerts a greater effect on VDR gene induction than equimolar doses of 1,25(OH)2 D3 in mice. PMID:23897575

  11. Effects of 1,25(OH)2 D3 and 25(OH)D3 on C2C12 Myoblast Proliferation, Differentiation, and Myotube Hypertrophy.

    PubMed

    van der Meijden, K; Bravenboer, N; Dirks, N F; Heijboer, A C; den Heijer, M; de Wit, G M J; Offringa, C; Lips, P; Jaspers, R T

    2016-11-01

    An adequate vitamin D status is essential to optimize muscle strength. However, whether vitamin D directly reduces muscle fiber atrophy or stimulates muscle fiber hypertrophy remains subject of debate. A mechanism that may affect the role of vitamin D in the regulation of muscle fiber size is the local conversion of 25(OH)D to 1,25(OH)2 D by 1α-hydroxylase. Therefore, we investigated in a murine C2C12 myoblast culture whether both 1,25(OH)2 D3 and 25(OH)D3 affect myoblast proliferation, differentiation, and myotube size and whether these cells are able to metabolize 25(OH)D3 and 1,25(OH)2 D3 . We show that myoblasts not only responded to 1,25(OH)2 D3 , but also to the precursor 25(OH)D3 by increasing their VDR mRNA expression and reducing their proliferation. In differentiating myoblasts and myotubes 1,25(OH)2 D3 as well as 25(OH)D3 stimulated VDR mRNA expression and in myotubes 1,25(OH)2 D3 also stimulated MHC mRNA expression. However, this occurred without notable effects on myotube size. Moreover, no effects on the Akt/mTOR signaling pathway as well as MyoD and myogenin mRNA levels were observed. Interestingly, both myoblasts and myotubes expressed CYP27B1 and CYP24 mRNA which are required for vitamin D3 metabolism. Although 1α-hydroxylase activity could not be shown in myotubes, after treatment with 1,25(OH)2 D3 or 25(OH)D3 myotubes showed strongly elevated CYP24 mRNA levels compared to untreated cells. Moreover, myotubes were able to convert 25(OH)D3 to 24R,25(OH)2 D3 which may play a role in myoblast proliferation and differentiation. These data suggest that skeletal muscle is not only a direct target for vitamin D3 metabolites, but is also able to metabolize 25(OH)D3 and 1,25(OH)2 D3 . J. Cell. Physiol. 231: 2517-2528, 2016. © 2016 The Authors. Journal of Cellular Physiology Published by Wiley Periodicals, Inc. PMID:27018098

  12. Highly Selective Dopamine D3 Receptor (D3R) Antagonists and Partial Agonists Based on Eticlopride and the D3R Crystal Structure: New Leads for Opioid Dependence Treatment.

    PubMed

    Kumar, Vivek; Bonifazi, Alessandro; Ellenberger, Michael P; Keck, Thomas M; Pommier, Elie; Rais, Rana; Slusher, Barbara S; Gardner, Eliot; You, Zhi-Bing; Xi, Zheng-Xiong; Newman, Amy Hauck

    2016-08-25

    The recent and precipitous increase in opioid analgesic abuse and overdose has inspired investigation of the dopamine D3 receptor (D3R) as a target for therapeutic intervention. Metabolic instability or predicted toxicity has precluded successful translation of previously reported D3R-selective antagonists to clinical use for cocaine abuse. Herein, we report a series of novel and D3R crystal structure-guided 4-phenylpiperazines with exceptionally high D3R affinities and/or selectivities with varying efficacies. Lead compound 19 was selected based on its in vitro profile: D3R Ki = 6.84 nM, 1700-fold D3R versus D2R binding selectivity, and its metabolic stability in mouse microsomes. Compound 19 inhibited oxycodone-induced hyperlocomotion in mice and reduced oxycodone-induced locomotor sensitization. In addition, pretreatment with 19 also dose-dependently inhibited the acquisition of oxycodone-induced conditioned place preference (CPP) in rats. These findings support the D3R as a target for opioid dependence treatment and compound 19 as a new lead molecule for development. PMID:27508895

  13. How cold is cold dark matter?

    SciTech Connect

    Armendariz-Picon, Cristian; Neelakanta, Jayanth T. E-mail: jtneelak@syr.edu

    2014-03-01

    If cold dark matter consists of particles, these must be non-interacting and non-relativistic by definition. In most cold dark matter models however, dark matter particles inherit a non-vanishing velocity dispersion from interactions in the early universe, a velocity that redshifts with cosmic expansion but certainly remains non-zero. In this article, we place model-independent constraints on the dark matter temperature to mass ratio, whose square root determines the dark matter velocity dispersion. We only assume that dark matter particles decoupled kinetically while non-relativistic, when galactic scales had not entered the horizon yet, and that their momentum distribution has been Maxwellian since that time. Under these assumptions, using cosmic microwave background and matter power spectrum observations, we place upper limits on the temperature to mass ratio of cold dark matter today (away from collapsed structures). These limits imply that the present cold dark matter velocity dispersion has to be smaller than 54 m/s. Cold dark matter has to be quite cold, indeed.

  14. IEC-^3He Breeder for D-^3He Satellite Systems.

    NASA Astrophysics Data System (ADS)

    Chacon, L.; Miley, G. H.

    1996-11-01

    D-^3He fusion minimizes neutrons and maximizes charged fusion products, enabling increased energy recovery efficiency by direct conversion. However, scarce ^3He terrestrial resources have deterred R&D on this alternative. Here, we explore ^3He production through Inertial Electrostatic Confinement^1 (IEC) D-breeders, which supply ^3He to FRC D-^3He satellite reactors.^2 Favorable features for the IEC breeder include simplicity, low cost, easy extraction of fusion products, and compatibility with direct conversion. The breeder-satellite system energy balance is analyzed taking the net energy gain of the overall system, Q_N, as the figure of merit. Breeding is applicable for systems where the satellite Q-value, Q_S, > the breeder Q-value, Q_B. For improved performance, i.e., for high Q_N, QS >= QB >> 1 is needed; however, lower QB values (typical of the IEC) are permissible and still offer sufficient Q_N. An economic study determined breeding produces ^3He at a cost comparable to lunar ^3He, already shown to lead to competitive power.^3 The cost of electricity (COE) for the breeder-satellite complex was compared with the ARTEMIS COE,^4 using lunar ^3He fuel: assuming one satellite (1000 MWe)/breeder (170 MWe), the ratio of the breeding system COE to the lunar mining base COE is ~ 1.2. However, economic breeding is driven by large IEC breeder powers, i.e., increased ^3He breeding rates. Thus, the COE ratio approaches unity with two or three satellites/breeder, requiring increased breeder size and power (340 MWe for 2 satellites, 510 MWe for 3 satellites). Such systems potentially provide a ``bridge'' to a future lunar ^3He economy. 1. G.H. Miley et al., Dense Z-pinches, AIP Conf. 299, AIP Press, 675-689 (1994). 2. G.H. Miley, Nucl. Instrum. Methods, A271, 197-202 (1988). 3. L.J. Wittenberg et al., Fusion Technol., 10, 167-178 (1986). 4. H. Momota et al., Fusion Technol., 21, 2307-2323 (1992).

  15. Long-term effects of 1,25-dihydroxy vitamin D3 and 24,25-dihydroxy vitamin D3 in renal osteodystrophy.

    PubMed

    Muirhead, N; Adami, S; Sandler, L M; Fraser, R A; Catto, G R; Edward, N; O'Riordan, J L

    1982-01-01

    Twenty-three patients with end-stage renal failure on maintenance haemodialysis were treated with 1,25-dihydroxy vitamin D3 or 24-25-dihydroxy vitamin D3 for 3-32 months (total 232 patient months). Treatment with 1,25-dihydroxy vitamin D3 was marked by symptomatic, biochemical and histological improvements in the majority of patients. In contrast, treatment with 24,25-dihydroxy vitamin D3 produced no biochemical or histological improvements and such patients developed severe symptomatic bone disease. Successful renal transplantation resulted in rapid improvement in symptoms, biochemistry and bone histology in nine of 10 patients irrespective of whether prior treatment was with 1,25-dihydroxy vitamin D3, 24,25-dihydroxy vitamin D3 or both. During treatment with 1,25-dihydroxy vitamin D3 progressive reduction in dosage was required in the majority of patients because of hypercalcaemia, which was rapidly corrected by stopping treatment for a few days. Hypercalcaemia did not occur until serum alkaline phosphatase (AP) and amino terminal parathyroid hormone (N-PTH) had fallen towards normal. Treatment failure was uncommon in 1,25-dihydroxy vitamin D3-treated patients and was characterized by the early development of hypercalcaemia. Addition of 24,25-dihydroxy vitamin D3 in such patients rendered the hypercalcaemia more manageable but did not lead to any further improvement in biochemistry or bone histology. Treatment with 24,25-dihydroxy vitamin D3 was accompanied by the development of severe symptomatic bone disease in the majority of patients and a characteristic pattern of biochemical abnormalities with hypocalcaemia and rises in AP and N-PTH. Substitution of 1,25-dihydroxy vitamin D3 treatment for 24,25-dihydroxy vitamin D3 in these patients resulted in prompt improvement in clinical, biochemical and histological abnormalities. Successful renal transplantation was accompanied by rapid resolution of clinical, biochemical and histological features of renal

  16. A Randomised, Cross-Over Study to Estimate the Influence of Food on the 25-Hydroxyvitamin D3 Serum Level after Vitamin D3 Supplementation

    PubMed Central

    Cavalier, Etienne; Jandrain, Bernard; Coffiner, Monte; Da Silva, Stéphanie; De Niet, Sophie; Vanderbist, Francis; Souberbielle, Jean-Claude

    2016-01-01

    Vitamin D3 is known to be liposoluble and its release could be a factor limiting the rate of absorption. It was presumed that the presence of fat could favor absorption of vitamin D3. However, as bioavailability is related not only to the active molecules but also to the formulations and excipients used, the optimization of the pharmaceutical form of vitamin D3 is also important. The objective of this study was to evaluate if there is a food effect on absorption when a high dose of vitamin D3 is completely solubilized in an oily solution. In the present cross-over study, 88 subjects were randomized and received a single dose of 50,000 IU of vitamin D3 in fasting state or with a standardized high-fat breakfast. Assessment of serum concentrations of 25 hydroxyvitamin D3 (25(OH)D3) was performed three, five, seven, 14, 30 and 60 days after supplementation. In fed and fast conditions, the 25(OH)D3 serum concentrations were significantly higher than the baseline value three days after administration and remained significantly higher during the first month. No significant difference between fasting vs. fed conditions was observed. It is therefore concluded that the vitamin D3 absorption from an oily solution was not influenced by the presence or absence of a meal. PMID:27213447

  17. Human responses to cold.

    PubMed

    Rintamäki, Hannu

    2007-01-01

    The thermoneutral ambient temperature for naked and resting humans is ca. 27 degrees C. Exposure to cold stimulates cold receptors of the skin which causes cold thermal sensations and stimulation of the sympathetic nervous system. Sympathetic stimulation causes vasoconstriction in skin, arms and legs. Diminished skin and extremity blood flow increases the thermal insulation of superficial tissues more than 300% corresponding to 0.9 clo (0.13 degrees C x m(-2) x W(-1)). With thermoregulatory vasoconstriction/ vasodilatation the body heat balance can be maintained within a range of ca. 4 degrees C, the middle of the range being at ca. 21 degrees C when light clothing is used. Below the thermoneutral zone metabolic heat production (shivering) is stimulated and above the zone starts heat loss by evaporation (sweating). Cold induced vasoconstriction increases blood pressure and viscosity and decreases plasma volume consequently increasing cardiac work. Cold induced hypertensive response can be counteracted by light exercise, while starting heavy work in cold markedly increases blood pressure. Under very cold conditions the sympathetic stimulation opens the anastomoses between arterioles and venules which increases skin temperatures markedly but temporarily, especially in finger tips. Adaptation to cold takes ca. 2 weeks, whereafter the physiological responses to cold are attenuated and cold exposure is subjectively considered less stressful. PMID:17929604

  18. Association study of dopamine D3 receptor gene and schizophrenia

    SciTech Connect

    Kennedy, J.L.; Billett, E.A.; Macciardi, F.M.

    1995-12-18

    Several groups have reported an association between schizophrenia and the MscI polymorphism in the first exon of the dopamine D3 receptor gene (DRD3). We studied this polymorphism using a North American sample (117 patients plus 188 controls) and an Italian sample (97 patients plus 64 controls). In the first part of the study, we compared allele frequencies of schizophrenia patients and unmatched controls and observed a significant difference in the total sample (P = 0.01). The second part of the study involved a case control approach in which each schizophrenia patient was matched to a control of the same sex, and of similar age and ethnic background. The DRD3 allele frequencies of patients and controls revealed no significant difference between the two groups in the Italian (N = 53) or the North American (N = 54) matched populations; however, when these two matched samples were combined, a significant difference was observed (P = 0.026). Our results suggest that the MscI polymorphism may be associated with schizophrenia in the populations studied. 32 refs., 2 tabs.

  19. Ammonia Induces Autophagy through Dopamine Receptor D3 and MTOR

    PubMed Central

    Li, Zhiyuan; Ji, Xinmiao; Wang, Wenchao; Liu, Juanjuan; Liang, Xiaofei; Wu, Hong; Liu, Jing; Eggert, Ulrike S.; Liu, Qingsong

    2016-01-01

    Hyperammonemia is frequently seen in tumor microenvironments as well as in liver diseases where it can lead to severe brain damage or death. Ammonia induces autophagy, a mechanism that tumor cells may use to protect themselves from external stresses. However, how cells sense ammonia has been unclear. Here we show that culture medium alone containing Glutamine can generate milimolar of ammonia at 37 degrees in the absence of cells. In addition, we reveal that ammonia acts through the G protein-coupled receptor DRD3 (Dopamine receptor D3) to induce autophagy. At the same time, ammonia induces DRD3 degradation, which involves PIK3C3/VPS34-dependent pathways. Ammonia inhibits MTOR (mechanistic target of Rapamycin) activity and localization in cells, which is mediated by DRD3. Therefore, ammonia has dual roles in autophagy: one to induce autophagy through DRD3 and MTOR, the other to increase autophagosomal pH to inhibit autophagic flux. Our study not only adds a new sensing and output pathway for DRD3 that bridges ammonia sensing and autophagy induction, but also provides potential mechanisms for the clinical consequences of hyperammonemia in brain damage, neurodegenerative diseases and tumors. PMID:27077655

  20. D3-instantons, mock theta series and twistors

    NASA Astrophysics Data System (ADS)

    Alexandrov, Sergei; Manschot, Jan; Pioline, Boris

    2013-04-01

    The D-instanton corrected hypermultiplet moduli space of type II string theory compactified on a Calabi-Yau threefold is known in the type IIA picture to be determined in terms of the generalized Donaldson-Thomas invariants, through a twistorial construction. At the same time, in the mirror type IIB picture, and in the limit where only D3-D1-D(-1)-instanton corrections are retained, it should carry an isometric action of the S-duality group SL(2, {Z} ). We prove that this is the case in the one-instanton approximation, by constructing a holomorphic action of SL(2, {Z} ) on the linearized twistor space. Using the modular invariance of the D4-D2-D0 black hole partition function, we show that the standard Darboux coordinates in twistor space have modular anomalies controlled by period integrals of a Siegel-Narain theta series, which can be canceled by a contact transformation generated by a holomorphic mock theta series.

  1. 2D/3D registration algorithm for lung brachytherapy

    SciTech Connect

    Zvonarev, P. S.; Farrell, T. J.; Hunter, R.; Wierzbicki, M.; Hayward, J. E.; Sur, R. K.

    2013-02-15

    Purpose: A 2D/3D registration algorithm is proposed for registering orthogonal x-ray images with a diagnostic CT volume for high dose rate (HDR) lung brachytherapy. Methods: The algorithm utilizes a rigid registration model based on a pixel/voxel intensity matching approach. To achieve accurate registration, a robust similarity measure combining normalized mutual information, image gradient, and intensity difference was developed. The algorithm was validated using a simple body and anthropomorphic phantoms. Transfer catheters were placed inside the phantoms to simulate the unique image features observed during treatment. The algorithm sensitivity to various degrees of initial misregistration and to the presence of foreign objects, such as ECG leads, was evaluated. Results: The mean registration error was 2.2 and 1.9 mm for the simple body and anthropomorphic phantoms, respectively. The error was comparable to the interoperator catheter digitization error of 1.6 mm. Preliminary analysis of data acquired from four patients indicated a mean registration error of 4.2 mm. Conclusions: Results obtained using the proposed algorithm are clinically acceptable especially considering the complications normally encountered when imaging during lung HDR brachytherapy.

  2. Effects of Cold Rolling and Strain-Induced Martensite Formation in a SAF 2205 Duplex Stainless Steel

    NASA Astrophysics Data System (ADS)

    Breda, Marco; Brunelli, Katya; Grazzi, Francesco; Scherillo, Antonella; Calliari, Irene

    2015-02-01

    Duplex stainless steels (DSSs) are biphasic steels having a ferritic-austenitic microstructure that allows them to combine good mechanical and corrosion-resistance properties. However, these steels are sensitive to microstructural modifications, such as ferrite decomposition at high temperatures and the possibility of strain-induced martensite (SIM) formation from cold-worked austenite, which can significantly alter their interesting features. In the present work, the effects of cold rolling on the developed microstructural features in a cold-rolled SAF 2205 DSS and the onset of martensitic transformation are discussed. The material was deformed at room temperature from 3 to 85 pct thickness reduction, and several characterization techniques (scanning and transmission electron microscopy, X-ray diffraction, hardness measurements, and time-of-flight-neutron diffraction) were employed in order to fully describe the microstructural behavior of the steel. Despite the low stacking fault energy of DSS austenite, which contributed to SIM formation, the steel was found to be more stable than other stainless steel grades, such as AISI 304L. Rolling textures were similar to those pertaining to single-phase materials, but the presence of the biphasic (Duplex) microstructure imposed deformation constraints that affected the developed microstructural features, owing to phases interactions. Moreover, even if an intensification of the strain field in austenite was revealed, retarded SIM transformation kinetics and lower martensite amounts with respect to AISI 304L were observed.

  3. Exposure to Cigarette Smoke Reduces Vitamin D3 in the Blood Stream and Respiratory Tract

    MedlinePlus

    ... respiratory tract Share | Exposure to cigarette smoke reduces vitamin D3 in the blood stream and respiratory tract ... be understood as to how smoke causes inflammation. Vitamin D3 has anti-inflammatory and anti-bacterial effects. ...

  4. Cold pool dissipation

    NASA Astrophysics Data System (ADS)

    Grant, Leah D.; Heever, Susan C.

    2016-02-01

    The mechanisms by which sensible heat fluxes (SHFs) alter cold pool characteristics and dissipation rates are investigated in this study using idealized two-dimensional numerical simulations and an environment representative of daytime, dry, continental conditions. Simulations are performed with no SHFs, SHFs calculated using a bulk formula, and constant SHFs for model resolutions with horizontal (vertical) grid spacings ranging from 50 m (25 m) to 400 m (200 m). In the highest resolution simulations, turbulent entrainment of environmental air into the cold pool is an important mechanism for dissipation in the absence of SHFs. Including SHFs enhances cold pool dissipation rates, but the processes responsible for the enhanced dissipation differ depending on the SHF formulation. The bulk SHFs increase the near-surface cold pool temperatures, but their effects on the overall cold pool characteristics are small, while the constant SHFs influence the near-surface environmental stability and the turbulent entrainment rates into the cold pool. The changes to the entrainment rates are found to be the most significant of the SHF effects on cold pool dissipation. SHFs may also influence the timing of cold pool-induced convective initiation by altering the environmental stability and the cold pool intensity. As the model resolution is coarsened, cold pool dissipation is found to be less sensitive to SHFs. Furthermore, the coarser resolution simulations not only poorly but sometimes wrongly represent the SHF impacts on the cold pools. Recommendations are made regarding simulating the interaction of cold pools with convection and the land surface in cloud-resolving models.

  5. Interactive client side data visualization with d3.js

    NASA Astrophysics Data System (ADS)

    Rodzianko, A.; Versteeg, R.; Johnson, D. V.; Soltanian, M. R.; Versteeg, O. J.; Girouard, M.

    2015-12-01

    Geoscience data associated with near surface research and operational sites is increasingly voluminous and heterogeneous (both in terms of providers and data types - e.g. geochemical, hydrological, geophysical, modeling data, of varying spatiotemporal characteristics). Such data allows scientists to investigate fundamental hydrological and geochemical processes relevant to agriculture, water resources and climate change. For scientists to easily share, model and interpret such data requires novel tools with capabilities for interactive data visualization. Under sponsorship of the US Department of Energy, Subsurface Insights is developing the Predictive Assimilative Framework (PAF): a cloud based subsurface monitoring platform which can manage, process and visualize large heterogeneous datasets. Over the last year we transitioned our visualization method from a server side approach (in which images and animations were generated using Jfreechart and Visit) to a client side one that utilizes the D3 Javascript library. Datasets are retrieved using web service calls to the server, returned as JSON objects and visualized within the browser. Users can interactively explore primary and secondary datasets from various field locations. Our current capabilities include interactive data contouring and heterogeneous time series data visualization. While this approach is very powerful and not necessarily unique, special attention needs to be paid to latency and responsiveness issues as well as to issues as cross browser code compatibility so that users have an identical, fluid and frustration-free experience across different computational platforms. We gratefully acknowledge support from the US Department of Energy under SBIR Award DOE DE-SC0009732, the use of data from the Lawrence Berkeley National Laboratory (LBNL) Sustainable Systems SFA Rifle field site and collaboration with LBNL SFA scientists.

  6. Cold fusion, Alchemist's dream

    SciTech Connect

    Clayton, E.D.

    1989-09-01

    In this report the following topics relating to cold fusion are discussed: muon catalysed cold fusion; piezonuclear fusion; sundry explanations pertaining to cold fusion; cosmic ray muon catalysed cold fusion; vibrational mechanisms in excited states of D{sub 2} molecules; barrier penetration probabilities within the hydrogenated metal lattice/piezonuclear fusion; branching ratios of D{sub 2} fusion at low energies; fusion of deuterons into {sup 4}He; secondary D+T fusion within the hydrogenated metal lattice; {sup 3}He to {sup 4}He ratio within the metal lattice; shock induced fusion; and anomalously high isotopic ratios of {sup 3}He/{sup 4}He.

  7. 26 CFR 1.1244(d)-3 - Stock dividend, recapitalizations, changes in name, etc.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 11 2010-04-01 2010-04-01 true Stock dividend, recapitalizations, changes in name, etc. 1.1244(d)-3 Section 1.1244(d)-3 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Special Rules for Determining Capital Gains and Losses § 1.1244(d)-3 Stock...

  8. 12 CFR 563d.3b-6 - Liability for certain statements by savings associations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 5 2010-01-01 2010-01-01 false Liability for certain statements by savings associations. 563d.3b-6 Section 563d.3b-6 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY SECURITIES OF SAVINGS ASSOCIATIONS Regulations § 563d.3b-6 Liability for certain statements by savings associations. This...

  9. Green Tea Polyphenols and Vitamin D3 Protect Bone Microarchitecture in Female Rats with Chronic Inflammation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our recent study showed that green tea polyphenols (GTP) in conjunction with 1-a-OH¬vit-D3 (vitD3) treatment mitigates lipopolysaccharide (LPS)-induced bone mineral density loss in female rats. This study was undertaken to further explore the mechanism and bone microarchitecture of GTP plus vitD3 in...

  10. 26 CFR 301.6104(d)-3 - Tax-exempt organization subject to harassment campaign.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... campaign. 301.6104(d)-3 Section 301.6104(d)-3 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE... Returns and Records § 301.6104(d)-3 Tax-exempt organization subject to harassment campaign. (a) In general... a copy (as otherwise required by § 301.6104(d)-1(a)) that it reasonably believes is part of...

  11. 26 CFR 301.6104(d)-3 - Tax-exempt organization subject to harassment campaign.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... campaign. 301.6104(d)-3 Section 301.6104(d)-3 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE... Returns and Records § 301.6104(d)-3 Tax-exempt organization subject to harassment campaign. (a) In general... a copy (as otherwise required by § 301.6104(d)-1(a)) that it reasonably believes is part of...

  12. 26 CFR 301.6104(d)-3 - Tax-exempt organization subject to harassment campaign.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... campaign. 301.6104(d)-3 Section 301.6104(d)-3 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE... Returns and Records § 301.6104(d)-3 Tax-exempt organization subject to harassment campaign. (a) In general... a copy (as otherwise required by § 301.6104(d)-1(a)) that it reasonably believes is part of...

  13. 26 CFR 1.1244(d)-3 - Stock dividend, recapitalizations, changes in name, etc.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 11 2011-04-01 2011-04-01 false Stock dividend, recapitalizations, changes in name, etc. 1.1244(d)-3 Section 1.1244(d)-3 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) Special Rules for Determining Capital Gains and Losses § 1.1244(d)-3...

  14. 42 CFR 51d.3 - Who is eligible for an award under this subpart?

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Who is eligible for an award under this subpart? 51d.3 Section 51d.3 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GRANTS MENTAL HEALTH AND SUBSTANCE ABUSE EMERGENCY RESPONSE PROCEDURES § 51d.3 Who is eligible for...

  15. 42 CFR 51d.3 - Who is eligible for an award under this subpart?

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Who is eligible for an award under this subpart? 51d.3 Section 51d.3 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GRANTS MENTAL HEALTH AND SUBSTANCE ABUSE EMERGENCY RESPONSE PROCEDURES § 51d.3 Who is eligible for...

  16. 42 CFR 51d.3 - Who is eligible for an award under this subpart?

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Who is eligible for an award under this subpart? 51d.3 Section 51d.3 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GRANTS MENTAL HEALTH AND SUBSTANCE ABUSE EMERGENCY RESPONSE PROCEDURES § 51d.3 Who is eligible for...

  17. 42 CFR 51d.3 - Who is eligible for an award under this subpart?

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Who is eligible for an award under this subpart? 51d.3 Section 51d.3 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GRANTS MENTAL HEALTH AND SUBSTANCE ABUSE EMERGENCY RESPONSE PROCEDURES § 51d.3 Who is eligible for...

  18. 42 CFR 51d.3 - Who is eligible for an award under this subpart?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Who is eligible for an award under this subpart? 51d.3 Section 51d.3 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GRANTS MENTAL HEALTH AND SUBSTANCE ABUSE EMERGENCY RESPONSE PROCEDURES § 51d.3 Who is eligible for...

  19. Treatment of an intramammary bacterial infection with 25-hydroxyvitamin D(3).

    PubMed

    Lippolis, John D; Reinhardt, Timothy A; Sacco, Randy A; Nonnecke, Brian J; Nelson, Corwin D

    2011-01-01

    Deficiency of serum levels of 25-hydroxyvitamin D(3) has been correlated with increased risk of infectious diseases such as tuberculosis and influenza. A plausible reason for this association is that expression of genes encoding important antimicrobial proteins depends on concentrations of 1,25-dihydroxyvitamin D(3) produced by activated immune cells at sites of infection, and that synthesis of 1,25-dihydroxyvitamin D(3) is dependent on the availability of 25-hydroxyvitamin D(3). Thus, increasing the availability of 25(OH)D(3) for immune cell synthesis of 1,25-dihydroxyvitamin D(3) at sites of infection has been hypothesized to aid in clearance of the infection. This report details the treatment of an acute intramammary infection with infusion of 25-hydroxyvitamin D(3) to the site of infection. Ten lactating cows were infected with in one quarter of their mammary glands. Half of the animals were treated intramammary with 25-hydroxyvitamin D(3). The 25-hydroxyvitamin D(3) treated animal showed significantly lower bacterial counts in milk and showed reduced symptomatic affects of the mastitis. It is significant that treatment with 25-hydroxyvitamin D(3) reduced the severity of an acute bacterial infection. This finding suggested a significant non-antibiotic complimentary role for 25-hydroxyvitamin D(3) in the treatment of infections in compartments naturally low in 25-hydroxyvitamin D(3) such as the mammary gland and by extension, possibly upper respiratory tract infections. PMID:21991312

  20. Transformation of 25- and 1 alpha-hydroxyvitamin D3 to 1 alpha, 25-dihydroxyvitamin D3 by using Streptomyces sp. strains.

    PubMed Central

    Sasaki, J; Mikami, A; Mizoue, K; Omura, S

    1991-01-01

    To enzymatically synthesize vitamin D derivatives, we screened about 300 Streptomyces sp. strains. Streptomyces sclerotialus FERM BP-1370 and Streptomyces roseoporus FERM BP-1574 were found to have the ability to convert 25-hydroxyvitamin D3 and 1 alpha-hydroxyvitamin D3, respectively, to 1 alpha, 25-dihydroxyvitamin D3. The average rates of 1 alpha hydroxylation of 25-hydroxyvitamin D3 were 6.9 micrograms liter-1 min-1 with FERM BP-1370 and 7.0 micrograms liter-1 min-1 with FERM BP-1574. The specific cytochrome P-450 inhibitors carbon monoxide, SKF-525-A, and metyrapone inhibited the hydroxylation of 1 alpha- and 25-hydroxyvitamin D3 to 1 alpha, 25-dihydroxyvitamin D3 by FERM BP-1370 and FERM BP-1574. The cytochromes P-450 of these strains were detected by reduced CO difference spectra in the whole-cell suspensions. The appearance of cytochrome P-450 suggests that the cytochromes P-450 of FERM BP-1370 and FERM BP-1574 carry out the hydroxylation of 25- and 1 alpha-hydroxyvitamin D3 to 1 alpha, 25-dihydroxyvitamin D3. PMID:1746944

  1. 1 alpha-hydroxyvitamin D3 plus 25-hydroxyvitamin D3 reduces parturient paresis in dairy cows fed high dietary calcium.

    PubMed

    Hodnett, D W; Jorgensen, N A; Deluca, H F

    1992-02-01

    The effectiveness of a combination of 1 alpha-hydroxyvitamin D3 and 25-hydroxyvitamin D3 for reducing incidence of parturient paresis in aged Holstein cows was tested. Intramuscular injection of .5 mg of 1 alpha-hydroxyvitamin D3 plus 4 mg of 25-hydroxyvitamin D3 increased plasma 1,25-dihydroxyvitamin D concentrations through parturition. Treatment with 1 alpha-hydroxyvitamin D3 plus 25-hydroxyvitamin D3 raised prepartum serum Ca approximately 2 mg/dl and prepartum serum P approximately 4 to 5 mg/dl higher than untreated controls. Both treated and control cows had approximately a 2-mg/dl decrease in serum Ca following parturition. The prepartum diet of alfalfa silage and hay was supplemented with a grain mixture supplying 100 g of Ca/d from ground limestone. Under these dietary conditions, incidence of parturient paresis was reduced from 33 to 8%. In a separate experiment, treatment with 1 alpha-hydroxyvitamin D3 plus 25-hydroxyvitamin D3 did not reduce incidence of parturient paresis when cows consumed mixed diets of different feed-stuff composition. Further experiments are required to determine specifically the factor or factors responsible for the difference in response to active vitamin D compound administration between the two experiments. Prepartum dietary Ca intake may be one such factor. PMID:1560144

  2. Endurance and failure characteristics of modified Vasco X-2, CBS 600 and AISI 9310 spur gears. [aircraft construction materials

    NASA Technical Reports Server (NTRS)

    Townsend, D. P.; Zaretsky, E. V.

    1980-01-01

    Gear endurance tests and rolling-element fatigue tests were conducted to compare the performance of spur gears made from AISI 9310, CBS 600 and modified Vasco X-2 and to compare the pitting fatigue lives of these three materials. Gears manufactured from CBS 600 exhibited lives longer than those manufactured from AISI 9310. However, rolling-element fatigue tests resulted in statistically equivalent lives. Modified Vasco X-2 exhibited statistically equivalent lives to AISI 9310. CBS 600 and modified Vasco X-2 gears exhibited the potential of tooth fracture occurring at a tooth surface fatigue pit. Case carburization of all gear surfaces for the modified Vasco X-2 gears results in fracture at the tips of the gears.

  3. Wear Evaluation of AISI 4140 Alloy Steel with WC/C Lamellar Coatings Sliding Against EN 8 Using Taguchi Method

    NASA Astrophysics Data System (ADS)

    Kadam, Nikhil Rajendra; Karthikeyan, Ganesarethinam

    2016-06-01

    The purpose of the experiments in this paper is to use the Taguchi methods to investigate the wear of WC/C coated nitrided AISI 4140 alloy steel. A study of lamellar WC/C coating which were deposited by a physical vapor deposition on nitrided AISI 4140 alloy steel. The investigation includes wear evaluation using Pin-on-disk configuration. When WC/C coated AISI 4140 alloy steel slides against EN 8 steel, it was found that carbon-rich coatings show much lower wear of the countersurface than nitrogen-rich coatings. The results were correlated with the properties determined from tribological and mechanical characterization, therefore by probably selecting the proper processing parameters the deposition of WC/C coating results in decreasing the wear rate of the substrate which shows a potential for tribological application.

  4. Comparison of 1,25(OH)2D3 and 24,25(OH)2D3 in the long-term treatment of renal osteodystrophy.

    PubMed

    Muirhead, N; Catto, G R; Edward, N; Fraser, R A; O'Riordan, J L; Papapoulos, S E; Adami, S

    1980-01-01

    24,25(OH)2D3 has been compared with 1,25(OH)2D3 in the treatment of renal osteodystrophy. Treatment with 24, 25(OH)2D3 2 micrograms/day for 5-7 months was accompanied by deterioration in clinical, biochemical, radiological and histological features of osteodystrophy with no increase in Ca absorption. In contrast, treatment with 1,25(OH)2D3 0.25--1 microgram/day for 6-15 months resulted in rapid improvement in clinical, biochemical, radiological and histological features and a return of Ca absorption to normal. It is concluded that in the dose used 24,25(OH)2D3 alone is not an effective treatment for renal osteodystrophy. PMID:6972529

  5. Cold stress and the cold pressor test.

    PubMed

    Silverthorn, Dee U; Michael, Joel

    2013-03-01

    Temperature and other environmental stressors are known to affect blood pressure and heart rate. In this activity, students perform the cold pressor test, demonstrating increased blood pressure during a 1- to 2-min immersion of one hand in ice water. The cold pressor test is used clinically to evaluate autonomic and left ventricular function. This activity is easily adapted to an inquiry format that asks students to go to the scientific literature to learn about the test and then design a protocol for carrying out the test in classmates. The data collected are ideal for teaching graphical presentation of data and statistical analysis. PMID:23471256

  6. Cold Tolerance of some Ralstonia solanacearum strains, including Race3 Biovar2, is conferred in part by variation in cold shock gene cspD3.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ralstonia solanacearum race 3 biovar 2 (R3B2) strains are one of only 10 USDA Select Agents, a category of quarantined pathogens reserved for the most serious threats to U.S. plant industry. The threat of R3B2 strains was not considered to be likely due to race (these are poorly defined) or biovar ...

  7. Dopamine D3 Receptor Is Necessary for Ethanol Consumption: An Approach with Buspirone

    PubMed Central

    Leggio, Gian Marco; Camillieri, Giovanni; Platania, Chiara B M; Castorina, Alessandro; Marrazzo, Giuseppina; Torrisi, Sebastiano Alfio; Nona, Christina N; D'Agata, Velia; Nobrega, José; Stark, Holger; Bucolo, Claudio; Le Foll, Bernard; Drago, Filippo; Salomone, Salvatore

    2014-01-01

    Mesolimbic dopamine (DA) controls drug- and alcohol-seeking behavior, but the role of specific DA receptor subtypes is unclear. We tested the hypothesis that D3R gene deletion or the D3R pharmacological blockade inhibits ethanol preference in mice. D3R-deficient mice (D3R−/−) and their wild-type (WT) littermates, treated or not with the D3R antagonists SB277011A and U99194A, were tested in a long-term free choice ethanol-drinking (two-bottle choice) and in a binge-like ethanol-drinking paradigm (drinking in the dark, DID). The selectivity of the D3R antagonists was further assessed by molecular modeling. Ethanol intake was negligible in D3R−/− and robust in WT both in the two-bottle choice and DID paradigms. Treatment with D3R antagonists inhibited ethanol intake in WT but was ineffective in D3R−/− mice. Ethanol intake increased the expression of RACK1 and brain-derived neurotrophic factor (BDNF) in both WT and D3R−/−; in WT there was also a robust overexpression of D3R. Thus, increased expression of D3R associated with activation of RACK1/BDNF seems to operate as a reinforcing mechanism in voluntary ethanol intake. Indeed, blockade of the BDNF pathway by the TrkB selective antagonist ANA-12 reversed chronic stable ethanol intake and strongly decreased the striatal expression of D3R. Finally, we evaluated buspirone, an approved drug for anxiety disorders endowed with D3R antagonist activity (confirmed by molecular modeling analysis), that resulted effective in inhibiting ethanol intake. Thus, DA signaling via D3R is essential for ethanol-related reward and consumption and may represent a novel therapeutic target for weaning. PMID:24584330

  8. Dopamine D3 receptor is necessary for ethanol consumption: an approach with buspirone.

    PubMed

    Leggio, Gian Marco; Camillieri, Giovanni; Platania, Chiara B M; Castorina, Alessandro; Marrazzo, Giuseppina; Torrisi, Sebastiano Alfio; Nona, Christina N; D'Agata, Velia; Nobrega, José; Stark, Holger; Bucolo, Claudio; Le Foll, Bernard; Drago, Filippo; Salomone, Salvatore

    2014-07-01

    Mesolimbic dopamine (DA) controls drug- and alcohol-seeking behavior, but the role of specific DA receptor subtypes is unclear. We tested the hypothesis that D3R gene deletion or the D3R pharmacological blockade inhibits ethanol preference in mice. D3R-deficient mice (D3R(-/-)) and their wild-type (WT) littermates, treated or not with the D3R antagonists SB277011A and U99194A, were tested in a long-term free choice ethanol-drinking (two-bottle choice) and in a binge-like ethanol-drinking paradigm (drinking in the dark, DID). The selectivity of the D3R antagonists was further assessed by molecular modeling. Ethanol intake was negligible in D3R(-/-) and robust in WT both in the two-bottle choice and DID paradigms. Treatment with D3R antagonists inhibited ethanol intake in WT but was ineffective in D3R(-/-) mice. Ethanol intake increased the expression of RACK1 and brain-derived neurotrophic factor (BDNF) in both WT and D3R(-/-); in WT there was also a robust overexpression of D3R. Thus, increased expression of D3R associated with activation of RACK1/BDNF seems to operate as a reinforcing mechanism in voluntary ethanol intake. Indeed, blockade of the BDNF pathway by the TrkB selective antagonist ANA-12 reversed chronic stable ethanol intake and strongly decreased the striatal expression of D3R. Finally, we evaluated buspirone, an approved drug for anxiety disorders endowed with D3R antagonist activity (confirmed by molecular modeling analysis), that resulted effective in inhibiting ethanol intake. Thus, DA signaling via D3R is essential for ethanol-related reward and consumption and may represent a novel therapeutic target for weaning. PMID:24584330

  9. AISI/DOE Advanced Process Control Program Vol. 6 of 6: Temperature Measurement of Galvanneal Steel

    SciTech Connect

    S.W. Allison; D.L. Beshears; W.W. Manges

    1999-06-30

    This report describes the successful completion of the development of an accurate in-process measurement instrument for galvanneal steel surface temperatures. This achievement results from a joint research effort that is a part of the American Iron and Steel Institute's (AISI) Advanced Process Control Program, a collaboration between the U.S> Department of Energy and fifteen North American Steelmakers. This three-year project entitled ''Temperature Measurement of Galvanneal Steel'' uses phosphor thermography, and outgrowth of Uranium enrichment research at Oak Ridge facilities. Temperature is the controlling factor regarding the distribution of iron and zinc in the galvanneal strip coating, which in turn determines the desired product properties

  10. Wear behavior of AISI 1090 steel modified by pulse plasma technique

    SciTech Connect

    Ayday, Aysun; Durman, Mehmet

    2012-09-06

    AISI 1090 steel was pulse plasma treated (PPT) using a Molybdenum electrode. Two different pulse numbers were chosen to obtain modified layers of 20{+-}5 {mu}m thickness. The dry sliding wear studies performed on this steel with and without PPT against an alumina ball counterpart showed that the PPT improved the wear resistance. The pulse number of the PPT modified layer was found to be highly influential in imparting the wear resistance to this steel, due to enhancement of surface hardness depending on treatment time.

  11. Microstructural Evolution and Wear Resistance of Friction Stir-Processed AISI 52100 Steel

    NASA Astrophysics Data System (ADS)

    Seraj, R. A.; Abdollah-zadeh, A.; Hajian, M.; Kargar, F.; Soltanalizadeh, R.

    2016-04-01

    Friction stir processing (FSP) was successfully applied on AISI 52100 steel. The influence of process parameters on the microstructure and mechanical properties of the material was evaluated. It was observed that the initial ferritic-pearlitic microstructure of the base metal is transformed to the martensitic microstructure with retained austenite in the stir zone. The results also showed that microhardness and wear resistance of the FSP samples are, respectively, at least 2 and 15 times higher than those of the base metal. The improvement of the mechanical properties of FSP samples was attributed to their microstructural characteristics. The mechanisms controlling the wear behavior of the base metal and FSP samples were also discussed.

  12. Microstructural Evolution and Wear Resistance of Friction Stir-Processed AISI 52100 Steel

    NASA Astrophysics Data System (ADS)

    Seraj, R. A.; Abdollah-zadeh, A.; Hajian, M.; Kargar, F.; Soltanalizadeh, R.

    2016-07-01

    Friction stir processing (FSP) was successfully applied on AISI 52100 steel. The influence of process parameters on the microstructure and mechanical properties of the material was evaluated. It was observed that the initial ferritic-pearlitic microstructure of the base metal is transformed to the martensitic microstructure with retained austenite in the stir zone. The results also showed that microhardness and wear resistance of the FSP samples are, respectively, at least 2 and 15 times higher than those of the base metal. The improvement of the mechanical properties of FSP samples was attributed to their microstructural characteristics. The mechanisms controlling the wear behavior of the base metal and FSP samples were also discussed.

  13. Experimental and Analytical Load-Life Relation for AISI 9310 Steel Spur Gears

    NASA Technical Reports Server (NTRS)

    Townsend, D. P.; Coy, J. J.; Zaretsky, E. V.

    1977-01-01

    Life tests were conducted at three different loads with three groups of 8.9 cm pitch diameter spur gears made of vacuum arc remelted VAR AISI 9310 steel. Life was found to vary inversely with load to the 4.3 and 5.1 power at the L10 sub and L50 sub life levels, respectively. The Weibull slope varied linearly with maximum Hertz contact stress, having an average value of 2.5. The test data when compared to AGMA standards showed a steeper slope for the load-life diagram.

  14. Compatibility of AISI 316 L stainless steel with the Li 17Pbg, eutectic

    NASA Astrophysics Data System (ADS)

    Coen, V.; Fenici, P.; Kolbe, H.; Orecchia, L.; Sasaki, T.

    1982-09-01

    The compatibility of AISI 316 L stainless steel with the Li 17Pb 83, eutectic has been studied in the temperature range 623-873 K for times up to 6000 h. In the corrosion layers formed there is a strong Ni depletion and Pb and Li penetration in the matrix. Tests at 623 K in Li 17Pb 83 on notched tensile specimens under a constant uniaxial tensile load, below the engineering yield stress, have evidenced that. many cracks filled with Pb and possibly Li are formed after relatively short times.

  15. Wear behavior of AISI 1090 steel modified by pulse plasma technique

    NASA Astrophysics Data System (ADS)

    Ayday, Aysun; Durman, Mehmet

    2012-09-01

    AISI 1090 steel was pulse plasma treated (PPT) using a Molybdenum electrode. Two different pulse numbers were chosen to obtain modified layers of 20±5 μm thickness. The dry sliding wear studies performed on this steel with and without PPT against an alumina ball counterpart showed that the PPT improved the wear resistance. The pulse number of the PPT modified layer was found to be highly influential in imparting the wear resistance to this steel, due to enhancement of surface hardness depending on treatment time.

  16. Prediction of Phase Transformation and Hardness Distribution of AISI 1045 Steel After Spot Continual Induction Hardening

    NASA Astrophysics Data System (ADS)

    Zhu, Shengxiao; Wang, Zhou; Qin, Xunpeng; Mao, Huajie; Gao, Kai

    2015-10-01

    An numerical and experimental study of spot continual induction hardening (SCIH) for AISI 1045 steel was carried out to gain a better understanding of this non-stationary and transverse flux induction hardening treatment. The SCIH device was set up by assembling the single-turn coil inductor to a five-axis cooperating computer numerical control system. The influence of inductor velocity, input current, and quenching medium on temperature field was estimated via the SCIH model, and the simulated micro-hardness and microstructure were validated by experimental verification. The heating delay phenomenon appearing in the SCIH process had been analyzed.

  17. Martensitic stainless steel AISI 420—mechanical properties, creep and fracture toughness

    NASA Astrophysics Data System (ADS)

    Brnic, J.; Turkalj, G.; Canadija, M.; Lanc, D.; Krscanski, S.

    2011-11-01

    In this paper some experimental results and analyses regarding the behavior of AISI 420 martensitic stainless steel under different environmental conditions are presented. That way, mechanical properties like ultimate tensile strength and 0.2 percent offset yield strength at lowered and elevated temperatures as well as short-time creep behavior for selected stress levels at selected elevated temperatures of mentioned material are shown. The temperature effect on mentioned mechanical properties is also presented. Fracture toughness was calculated on the basis of Charpy impact energy. Experimentally obtained results can be of importance for structure designers.

  18. Study of passive films formed on AISI 304 stainless steel by impedance measurements and photoelectrochemistry

    SciTech Connect

    Simoes, A.M.P.; Ferreiro, M.G.S. ); Rondot, B.; Belo, M. . Centre d'Etudes de Chimie Metallurgique)

    1990-01-01

    Moss-Schottky plots and photoelectrochemical measurements were made on films formed at different potentials on AISI 304 stainless steel in a borate/boric acid solution, pH 9.2. The results allowed the determination of the semiconductive properties and band structure of the films, which account for the existence of two kinds of films depending on the formation potential. For potentials below 0 V (SCE), the results point out for a film with an inverse spinel structure constituted by Cr-substituted magnetite with two donor levels. Above 0 V only one donor level is detected, which should be Fe{sup 2 +} on tetrahedral sites.

  19. The structural characterization of some biomaterials, type AISI 310, used in medicine

    NASA Astrophysics Data System (ADS)

    Minciuna, M. G.; Vizureanu, P.; Hanganu, C.; Achitei, D. C.; Popescu, D. C.; Focsaneanu, S. C.

    2016-06-01

    Orthopedics biomaterials are intended for implantation in the human body and substituted or help to repair of bones, cartilage or organ transplant, and tendons. At the end of the 20th century, the availability of materials for the manufacture implants used in medicine has been the same as for other industrial applications. The most used metals for manufacturing the orthopedics implants are: stainless steels, cobalt-chrome-molybdenum alloys, titanium and his alloys. The structural researches which are made in this paper, offer a complete analysis of AISI310 stainless steels, using: optical spectrometry, X-ray diffraction and scanning electronic microscopy.

  20. Microstructural Evolution During Friction Surfacing of Austenitic Stainless Steel AISI 304 on Low Carbon Steel

    NASA Astrophysics Data System (ADS)

    Khalid Rafi, H.; Kishore Babu, N.; Phanikumar, G.; Prasad Rao, K.

    2013-01-01

    Austenitic stainless steel AISI 304 coating was deposited over low carbon steel substrate by means of friction surfacing and the microstructural evolution was studied. The microstructural characterization of the coating was carried out by optical microscopy (OM), electron back scattered diffraction (EBSD), and transmission electron microscopy (TEM). The coating exhibited refined grains (average size of 5 μm) as compared to the coarse grains (average size of 40 μm) in as-received consumable rod. The results from the microstructural characterization studies show that discontinuous dynamic recrystallization (DDRX) is the responsible mechanism for grain evolution as a consequence of severe plastic deformation.

  1. Electrochemical investigation of passive film in pre-deformation AISI 304 stainless steels

    NASA Astrophysics Data System (ADS)

    Jinlong, Lv; Hongyun, Luo

    2012-12-01

    The electrochemical measures in deformed AISI 304 stainless steels ranged from 0% to 24% were investigated. With the increasing of the strain α'-martensite was gradually increasing. Moreover, the morphologies and densities of dislocations changed with increasing strain. The Mott-Schottky plots showed that the maximum total of donor and acceptor densities in passive film occurred in borate buffer solution when ɛ-martensite was most, while in borate buffer solution with 5000 ppm Cl- the maximum total of donor and acceptor densities occurred when the content of α-martensite was most. These results were proven by further impedance spectroscopy experiments.

  2. Effect of environmental factors and yield strength on SSC property of AISI 420 stainless steel

    SciTech Connect

    Sakamoto, S.; Kawakami, A.; Asahi, H.; Nakamura, A.

    1995-09-01

    Study on service limit of AISI 420 stainless steel for sour environment is conducted. Since SSC is a phenomenon of hydrogen embrittlement, the measurement of hydrogen content in steel is a key factor to the predict SSC occurrence. SSC occurs if hydrogen content entering into steel exceeds a critical hydrogen content for the steel. Comparison of both values of hydrogen contents enables to estimate critical environmental conditions and yield strength. Estimation results by this method coincides well with data in several literatures. Through this appraisal,specially heat-treated low yield strength 13Cr steel was found to be a good candidate for sour service.

  3. Experimental Design and Data collection of a finishing end milling operation of AISI 1045 steel

    PubMed Central

    Dias Lopes, Luiz Gustavo; de Brito, Tarcísio Gonçalves; de Paiva, Anderson Paulo; Peruchi, Rogério Santana; Balestrassi, Pedro Paulo

    2016-01-01

    In this Data in Brief paper, a central composite experimental design was planned to collect the surface roughness of an end milling operation of AISI 1045 steel. The surface roughness values are supposed to suffer some kind of variation due to the action of several factors. The main objective here was to present a multivariate experimental design and data collection including control factors, noise factors, and two correlated responses, capable of achieving a reduced surface roughness with minimal variance. Lopes et al. (2016) [1], for example, explores the influence of noise factors on the process performance. PMID:26909374

  4. Primary cold agglutinin disease.

    PubMed

    Mondal, Prabodh Chandra; Chakraborty, Partha Pratim; Bera, Mitali

    2011-07-01

    A 4-year-old girl presented with severe pallor and intermittent passage of cola-coloured urine. Routine investigations were suggestive of auto-immune haemolytic anaemia. Red cell agglutination was observed in peripheral smear and patient's serum was positive for cold agglutinins. Thorough work-up ruled out secondary cold agglutinin disease. Patient was treated successfully with corticosteroids. PMID:22315851

  5. Cold Sores (HSV-1)

    MedlinePlus

    ... Help a Friend Who Cuts? Cold Sores (HSV-1) KidsHealth > For Teens > Cold Sores (HSV-1) Print A A A Text Size What's in ... person's lips, are caused by herpes simplex virus-1 (HSV-1) . But they don't just show ...

  6. Liquid metal cold trap

    DOEpatents

    Hundal, Rolv

    1976-01-01

    A cold trap assembly for removing impurities from a liquid metal being provided with a hole between the incoming impure liquid metal and purified outgoing liquid metal which acts as a continuous bleed means and thus prevents the accumulation of cover gases within the cold trap assembly.

  7. Cold fusion research

    SciTech Connect

    1989-11-01

    I am pleased to forward to you the Final Report of the Cold Fusion Panel. This report reviews the current status of cold fusion and includes major chapters on Calorimetry and Excess Heat, Fusion Products and Materials Characterization. In addition, the report makes a number of conclusions and recommendations, as requested by the Secretary of Energy.

  8. Photoactivable analogs for labeling 25-hydroxyvitamin D3 serum binding protein and for 1,25-dihydroxyvitamin D3 intestinal receptor protein

    NASA Technical Reports Server (NTRS)

    Kutner, A.; Link, R. P.; Schnoes, H. K.; DeLuca, H. F.

    1986-01-01

    3-Azidobenzoates and 3-azidonitrobenzoates of 25-hydroxyvitamin D3 as well as 3-deoxy-3-azido-25-hydroxyvitamin D3 and 3-deoxy-3-azido-1,25-dihydroxyvitamin D3 were prepared as photoaffinity labels for vitamin D serum binding protein and 1,25-dihydroxyvitamin D3 intestinal receptor protein. The compounds prepared were easily activated by short- or long-wavelength uv light, as monitored by uv and ir spectrometry. The efficacy of the compounds to compete with 25-hydroxyvitamin D3 or 1,25-dihydroxyvitamin D3 for the binding site of serum binding protein and receptor, respectively, was studied to evaluate the vitamin D label with the highest affinity for the protein. The presence of an azidobenzoate or azidonitrobenzoate substituent at the C-3 position of 25-OH-D3 significantly decreased (10(4)- to 10(6)-fold) the binding activity. However, the labels containing the azido substituent attached directly to the vitamin D skeleton at the C-3 position showed a high affinity, only 20- to 150-fold lower than that of the parent compounds with their respective proteins. Therefore, 3-deoxy-3-azidovitamins present potential ligands for photolabeling of vitamin D proteins and for studying the structures of the protein active sites.

  9. 25-Hydroxyvitamin D(3) suppresses PTH synthesis and secretion by bovine parathyroid cells.

    PubMed

    Ritter, C S; Armbrecht, H J; Slatopolsky, E; Brown, A J

    2006-08-01

    Active vitamin D compounds repress parathyroid hormone (PTH) gene transcription and block chief cell hyperplasia, making them integral tools in the treatment of secondary hyperparathyroidism in patients with chronic kidney disease. Recently, human parathyroid glands have been shown to express 25-hydroxyvitamin D 1alpha-hydroxylase (1alphaOHase), but documentation of the 1alphaOHase activity in parathyroid cells and its potential role in activating 25-hydroxyvitamin D(3) (25(OH)D(3)) to 1,25-dihydroxyvitamin D(3) (1,25(OH)2D3) have not been reported. The relative potencies of 25(OH)D(3) and 1,25(OH)(2)D(3) in reducing PTH secretion and mRNA were determined in primary cultures of bovine parathyroid cells (bPTC). The effects of blocking 1alphaOHase activity on suppression of PTH mRNA and induction of 24-hydroxylase mRNA were examined. Vitamin D receptor (VDR) affinities were estimated by intact cell competitive binding assay. Metabolism of 25(OH)D(3) by bPTC was assessed using a radioimmunoassay that measures all 1-hydroxylated metabolites of vitamin D. 25(OH)D(3) suppressed PTH secretion and mRNA (ED(50)=2 nM), but was several hundred times less potent than 1,25(OH)(2)D(3). The lower potency of 25(OH)D(3) correlated with its lower VDR affinity. bPTCs converted 25(OH)D(3) to 1-hydroxylated metabolites, but the rate of conversion was low. Inhibition of 1alphaOHase with the cytochrome P450 inhibitor clotrimazole did not block 25(OH)D(3)-mediated suppression of PTH. Clotrimazole enhanced 24-hydroxylase mRNA induction, presumably by inhibiting catabolism of 25(OH)D(3). In conclusion, 25(OH)D(3) suppresses PTH synthesis by parathyroid cells, possibly by direct activation of the VDR. PMID:16807549

  10. Hypothermia: A Cold Weather Hazard

    MedlinePlus

    ... Weather Hazard Heath and Aging Hypothermia: A Cold Weather Hazard What Are The Signs Of Hypothermia? Taking ... cold air. But, not everyone knows that cold weather can also lower the temperature inside your body. ...

  11. Modelling of Tool Wear and Residual Stress during Machining of AISI H13 Tool Steel

    NASA Astrophysics Data System (ADS)

    Outeiro, José C.; Umbrello, Domenico; Pina, José C.; Rizzuti, Stefania

    2007-05-01

    Residual stresses can enhance or impair the ability of a component to withstand loading conditions in service (fatigue, creep, stress corrosion cracking, etc.), depending on their nature: compressive or tensile, respectively. This poses enormous problems in structural assembly as this affects the structural integrity of the whole part. In addition, tool wear issues are of critical importance in manufacturing since these affect component quality, tool life and machining cost. Therefore, prediction and control of both tool wear and the residual stresses in machining are absolutely necessary. In this work, a two-dimensional Finite Element model using an implicit Lagrangian formulation with an automatic remeshing was applied to simulate the orthogonal cutting process of AISI H13 tool steel. To validate such model the predicted and experimentally measured chip geometry, cutting forces, temperatures, tool wear and residual stresses on the machined affected layers were compared. The proposed FE model allowed us to investigate the influence of tool geometry, cutting regime parameters and tool wear on residual stress distribution in the machined surface and subsurface of AISI H13 tool steel. The obtained results permit to conclude that in order to reduce the magnitude of surface residual stresses, the cutting speed should be increased, the uncut chip thickness (or feed) should be reduced and machining with honed tools having large cutting edge radii produce better results than chamfered tools. Moreover, increasing tool wear increases the magnitude of surface residual stresses.

  12. Modeling of the flow stress for AISI H13 Tool Steel during Hard Machining Processes

    NASA Astrophysics Data System (ADS)

    Umbrello, Domenico; Rizzuti, Stefania; Outeiro, José C.; Shivpuri, Rajiv

    2007-04-01

    In general, the flow stress models used in computer simulation of machining processes are a function of effective strain, effective strain rate and temperature developed during the cutting process. However, these models do not adequately describe the material behavior in hard machining, where a range of material hardness between 45 and 60 HRC are used. Thus, depending on the specific material hardness different material models must be used in modeling the cutting process. This paper describes the development of a hardness-based flow stress and fracture models for the AISI H13 tool steel, which can be applied for range of material hardness mentioned above. These models were implemented in a non-isothermal viscoplastic numerical model to simulate the machining process for AISI H13 with various hardness values and applying different cutting regime parameters. Predicted results are validated by comparing them with experimental results found in the literature. They are found to predict reasonably well the cutting forces as well as the change in chip morphology from continuous to segmented chip as the material hardness change.

  13. Microstructure, Mechanical and Corrosion Properties of Friction Stir-Processed AISI D2 Tool Steel

    NASA Astrophysics Data System (ADS)

    Yasavol, Noushin; Jafari, Hassan

    2015-05-01

    In this study, AISI D2 tool steel underwent friction stir processing (FSP). The microstructure, mechanical properties, and corrosion resistance of the FSPed materials were then evaluated. A flat WC-Co tool was used; the rotation rate of the tool varied from 400 to 800 rpm, and the travel speed was maintained constant at 385 mm/s during the process. FSP improved mechanical properties and produced ultrafine-grained surface layers in the tool steel. Mechanical properties improvement is attributed to the homogenous distribution of two types of fine (0.2-0.3 μm) and coarse (1.6 μm) carbides in duplex ferrite-martensite matrix. In addition to the refinement of the carbides, the homogenous dispersion of the particles was found to be more effective in enhancing mechanical properties at 500 rpm tool rotation rate. The improved corrosion resistance was observed and is attributed to the volume fraction of low-angle grain boundaries produced after friction stir process of the AISI D2 steel.

  14. Surface Treatments for Improved Performance of Spinel-coated AISI 441 Ferritic Stainless Steel

    SciTech Connect

    Stevenson, Jeffry W.; Riel, Eric M.; Stephens, Elizabeth V.; Khaleel, Mohammad A.

    2013-01-01

    Ferritic stainless steels are promising candidates for IT-SOFC interconnect applications due to their low cost and resistance to oxidation at SOFC operating temperatures. However, steel candidates face several challenges; including long term oxidation under interconnect exposure conditions, which can lead to increased electrical resistance, surface instability, and poisoning of cathodes due to volatilization of Cr. To potentially extend interconnect lifetime and improve performance, a variety of surface treatments were performed on AISI 441 ferritic stainless steel coupons prior to application of a protective spinel coating. The coated coupons were then subjected to oxidation testing at 800 and 850°C in air, and electrical testing at 800°C in air. While all of the surface-treatments resulted in improved surface stability (i.e., increased spallation resistance) compared to untreated AISI 441, the greatest degree of improvement (through 20,000 hours of testing at 800°C and 14,000 hours of testing at 850°C) was achieved by surface blasting.

  15. Modeling of the flow stress for AISI H13 Tool Steel during Hard Machining Processes

    SciTech Connect

    Umbrello, Domenico; Rizzuti, Stefania; Outeiro, Jose C.; Shivpuri, Rajiv

    2007-04-07

    In general, the flow stress models used in computer simulation of machining processes are a function of effective strain, effective strain rate and temperature developed during the cutting process. However, these models do not adequately describe the material behavior in hard machining, where a range of material hardness between 45 and 60 HRC are used. Thus, depending on the specific material hardness different material models must be used in modeling the cutting process. This paper describes the development of a hardness-based flow stress and fracture models for the AISI H13 tool steel, which can be applied for range of material hardness mentioned above. These models were implemented in a non-isothermal viscoplastic numerical model to simulate the machining process for AISI H13 with various hardness values and applying different cutting regime parameters. Predicted results are validated by comparing them with experimental results found in the literature. They are found to predict reasonably well the cutting forces as well as the change in chip morphology from continuous to segmented chip as the material hardness change.

  16. Effects of biofilm formation on the electrochemical behavior of AISI 304 SS in board machine environment

    SciTech Connect

    Carp, L.; Hakkarainen, T.; Raaska, L.

    1999-11-01

    The electrochemical behavior of and biofilm formation on AISI 304 stainless steel were studied in board machine environment with natural bacteria population. Open circuit potentials, redox-potential as well as different electrochemical measurements were performed. The biofilms formed were analyzed by microbial cultivation and by epifluorescence microscopy. The results of the measurements were compared with those performed both in sterilized white water and in artificial white water. The anodic polarization behavior of just immersed specimens was very similar in biotic (real), artificial and abiotic (sterilized) white water. Pitting initiated at very low potentials and continued to very negative values. The initiation of pitting became more difficult when the immersion time increased to 7 or 8 days in real, artificial or sterilized water. When the immersion time further increased, the pitting nucleated more easily in sterilized white water as well as in artificial white water than in biotic white water. In the laboratory equipment it was possible to maintain the biofilm already formed in the board mill, but the amount of sulfate reducing bacteria decreased and the amount of biofilm did not further increase. The composition and structure of the biofilm formed in laboratory differed from that formed in board mill conditions. The preliminary results indicate that the formation of biofilm in biotic white water rather inhibits than enhances the pitting corrosion of type AISI 304 stainless steel.

  17. Improvement in cavitation erosion resistance of AISI 316L stainless steel by friction stir processing

    NASA Astrophysics Data System (ADS)

    Hajian, M.; Abdollah-zadeh, A.; Rezaei-Nejad, S. S.; Assadi, H.; Hadavi, S. M. M.; Chung, K.; Shokouhimehr, M.

    2014-07-01

    Commercial AISI 316L plates with the initial grain size of 14.8 μm were friction stir processed (FSP) with different processing parameters, resulting in two fine-grained microstructures with the grain sizes of 4.6 and 1.7 μm. The cavitation erosion behavior, before and after FSP, was evaluated in terms of incubation time, cumulative mass loss and mean depth of erosion. A separate cavitation erosion test was performed on the transverse cross section of a FSP sample to reveal the effect of grain structure. It was observed that FSP samples, depending on their grain size, are at least 3-6 times more resistant than the base material against cavitation erosion. The improvement in cavitation erosion resistance is attributed to smaller grain structure, lower fraction of twin boundaries, and favorable crystallographic orientation of grains in FSP samples. The finer the grain size, the more cavitation erosion resistance was achieved. Moreover, the microstructures of eroded surfaces were studied using a scanning electron microscope equipped with EBSD, and an atomic force microscope. The mechanisms controlling the cavitation erosion damage in friction stir processed AISI 316L are also discussed.

  18. A Computational Study of Plastic Deformation in AISI 304 Induced by Surface Mechanical Attrition Treatment

    NASA Astrophysics Data System (ADS)

    Zhang, X. C.; Lu, J.; Shi, S. Q.

    2010-05-01

    As a technique of grain refinement process by plastic deformation, surface mechanical attrition treatment (SMAT) has been developed to be one of the most effective ways to optimize the mechanical properties of various materials including pure metals and alloys. SMAT can significantly reduce grain size into nanometer regime in the surface layer of bulk materials, providing tremendous opportunities for improving physical, chemical and mechanical properties of the materials. In this work, a computational modeling of the surface mechanical attrition treatment (SMAT) process is presented, in which Johnson-Cook plasticity model and the finite element method were employed to study the high strain rate, elastic-plastic dynamic process of ball impact on a metallic target. AISI 304 steel with low stacking fault energy was chosen as the target material. First, a random impact model was used to analyze the statistic characteristics of ball impact, and then the plastic deformation behavior and residual stress distribution in AISI 304 stainless steel during SMAT were studied. The simulation results show that the compressive residual stress and vertical deformation of the surface structures were directly affected by ball impact frequency, incident impact angle and ball diameter used in SMAT process.

  19. Niobium boride layers deposition on the surface AISI D2 steel by a duplex treatment

    NASA Astrophysics Data System (ADS)

    Kon, O.; Pazarlioglu, S.; Sen, S.; Sen, U.

    2015-03-01

    In this paper, we investigated the possibility of deposition of niobium boride layers on the surface of AISI D2 steel by a duplex treatment. At the first step of duplex treatment, boronizing was performed on AISI D2 steel samples at 1000oC for 2h and then pre-boronized samples niobized at 850°C, 900°C and 950°C using thermo-reactive deposition method for 1-4 h. The presence of the niobium boride layers such as NbB, NbB2 and Nb3B4 and also iron boride phases such as FeB, Fe2B were examined by X-ray diffraction analysis. Scanning electron microscope (SEM) and micro-hardness measurements were realized. Experimental studies showed that the depth of the coating layers increased with increasing temperature and times and also ranged from 0.42 µm to 2.43 µm, depending on treatment time and temperature. The hardness of the niobium boride layer was 2620±180 HV0.005.

  20. Modelling of Tool Wear and Residual Stress during Machining of AISI H13 Tool Steel

    SciTech Connect

    Outeiro, Jose C.; Pina, Jose C.; Umbrello, Domenico; Rizzuti, Stefania

    2007-05-17

    Residual stresses can enhance or impair the ability of a component to withstand loading conditions in service (fatigue, creep, stress corrosion cracking, etc.), depending on their nature: compressive or tensile, respectively. This poses enormous problems in structural assembly as this affects the structural integrity of the whole part. In addition, tool wear issues are of critical importance in manufacturing since these affect component quality, tool life and machining cost. Therefore, prediction and control of both tool wear and the residual stresses in machining are absolutely necessary. In this work, a two-dimensional Finite Element model using an implicit Lagrangian formulation with an automatic remeshing was applied to simulate the orthogonal cutting process of AISI H13 tool steel. To validate such model the predicted and experimentally measured chip geometry, cutting forces, temperatures, tool wear and residual stresses on the machined affected layers were compared. The proposed FE model allowed us to investigate the influence of tool geometry, cutting regime parameters and tool wear on residual stress distribution in the machined surface and subsurface of AISI H13 tool steel. The obtained results permit to conclude that in order to reduce the magnitude of surface residual stresses, the cutting speed should be increased, the uncut chip thickness (or feed) should be reduced and machining with honed tools having large cutting edge radii produce better results than chamfered tools. Moreover, increasing tool wear increases the magnitude of surface residual stresses.

  1. Sensitization of AISI 302 stainless steel during low-power laser forming

    NASA Astrophysics Data System (ADS)

    Walczak, M.; Ramos-Grez, J.; Celentano, D.; Lima, E. B. F.

    2010-09-01

    Low-power laser forming by raster scanning is a promising technology for shaping thin sheets in a non-contact manner, using a laser beam scanned over the surface. In this work, the change of material microstructure and the related corrosion behavior are investigated in the context of local temperature evolution during the scanning action. Graphite coated AISI 302 stainless steel coupons have been bent to different angles using a 60 W CO 2 laser and the resulting cyclic polarization behavior in sulfuric acid was measured. The so revealed sensitization of the material is discussed on the basis of microstructural changes caused by temperature-induced phase transformations. The total times of permanence at temperatures favoring specific transformations were obtained by numerical simulation of the process. It was found that even when no surface melting takes place the recurrent rise of temperature within the material is sufficient to sensitize the non-irradiated side. This effect might be a limiting factor in applications of laser formed AISI 302 in corrosive environments.

  2. Pack Cementation Coatings for High-Temperature Oxidation Resistance of AISI 304 Stainless Steel

    NASA Astrophysics Data System (ADS)

    Zandrahimi, Morteza; Vatandoost, Javad; Ebrahimifar, Hadi

    2012-10-01

    Aluminum and titanium are deposited on the surface of steel by the pack cementation method to improve its hot-corrosion and high-temperature oxidation resistance. In this research, coatings of aluminum and titanium and a two-step coating of aluminum and titanium were applied on an AISI 304 stainless steel substrate. The coating layers were examined by carrying out scanning electron microscopy (SEM) and x-ray diffraction (XRD). The SEM results showed that the aluminized coating consisted of two layers with a thickness of 450 μm each, the titanized coating consisted of two layers with a thickness of 100 μm each, and the two-step coatings of Al and Ti consisted of three layers with a thickness of 200 μm each. The XRD investigation of the coatings showed that the aluminized coating consisted of Al2O3, AlCr2, FeAl, and Fe3Al phases; the titanized layers contained TiO2, Ni3Ti, FeNi, and Fe2TiO5 phases; and the two-step coating contained AlNi, Ti3Al, and FeAl phases. The uncoated and coated specimens were subjected to isothermal oxidation at 1050 °C for 100 h. The oxidation results revealed that the application of a coating layer increased the oxidation resistance of the coated AISI 304 samples as opposed to the uncoated ones.

  3. Variation in sessile microflora during biofilm formation on AISI-304 stainless steel coupons.

    PubMed

    de França, F P; Lutterbach, M T

    1996-07-01

    Coupons of stainless steel type AISI-304 were exposed to the industrial cooling system of a petrochemical plant fed by seawater from the Guanabara Bay, Rio de Janeiro, Brazil, in order to study the in situ formation of biofilms. Bacteria, microalgae and fungi were detected on the coupons as soon as 48 h after exposure. Their respective numbers were determined at times 48, 96 and 192 h and over the following 8 weeks. Aerobic, anaerobic and sulfate-reducing bacteria were quantified according to the technique of the most probable number, and fungi by the pour plate technique. The number of microorganisms present in the forming biofilm varied over the experimental period, reaching maximal levels of 14 x 10(11) cells cm-2, 30 x 10(13) cells cm-2, 38 x 10(11) cells cm-2 and 63 x 10(5) cells cm-2, respectively, for aerobic bacteria, anaerobic bacteria, sulfate-reducing bacteria and fungi, and the dynamics of this variation depended on the group of microorganisms. Bacillus sp, Escherichia coli, Serratia sp and Pseudomonas putrefaciens were identified among the aerobic bacteria isolated. Additionally, microalgae and bacteria of the genus Gallionella were also detected. Nonetheless, no evidence of corrosion was found on the stainless steel type AISI-304 coupons over the experimental period. PMID:8987686

  4. Microstructure, Texture, and Mechanical Property Analysis of Gas Metal Arc Welded AISI 304 Austenitic Stainless Steel

    NASA Astrophysics Data System (ADS)

    Saha, Saptarshi; Mukherjee, Manidipto; Pal, Tapan Kumar

    2015-03-01

    The present study elaborately explains the effect of welding parameters on the microstructure, texture, and mechanical properties of gas metal arc welded AISI 304 austenitic stainless steel sheet (as received) of 4 mm thickness. The welded joints were prepared by varying welding speed (WS) and current simultaneously at a fixed heat input level using a 1.2-mm-diameter austenitic filler metal (AISI 316L). The overall purpose of this study is to investigate the effect of the variation of welding conditions on: (i) Microstructural constituents using optical microscope and transmission electron microscope; (ii) Micro-texture evolution, misorientation distributions, and grain boundaries at welded regions by measuring the orientation data from electron back scattered diffraction; and (iii) Mechanical properties such as hardness and tensile strength, and their correlation with the microstructure and texture. It has been observed that the higher WS along with the higher welding current (weld metal W1) can enhance weld metal mechanical properties through alternation in microstructure and texture of the weld metal. Higher δ-ferrite formation and high-angle boundaries along with the <101> + <001> grain growth direction of the weld metal W1 were responsible for dislocation pile-ups, SFs, deformation twinning, and the induced martensite with consequent strain hardening during tensile deformation. Also, fusion boundary being the weakest link in the welded structure, failure took place mainly at this region.

  5. Niobium boride layers deposition on the surface AISI D2 steel by a duplex treatment

    SciTech Connect

    Kon, O.; Pazarlioglu, S.

    2015-03-30

    In this paper, we investigated the possibility of deposition of niobium boride layers on the surface of AISI D2 steel by a duplex treatment. At the first step of duplex treatment, boronizing was performed on AISI D2 steel samples at 1000{sup o}C for 2h and then pre-boronized samples niobized at 850°C, 900°C and 950°C using thermo-reactive deposition method for 1–4 h. The presence of the niobium boride layers such as NbB, NbB{sub 2} and Nb{sub 3}B{sub 4} and also iron boride phases such as FeB, Fe{sub 2}B were examined by X-ray diffraction analysis. Scanning electron microscope (SEM) and micro-hardness measurements were realized. Experimental studies showed that the depth of the coating layers increased with increasing temperature and times and also ranged from 0.42 µm to 2.43 µm, depending on treatment time and temperature. The hardness of the niobium boride layer was 2620±180 HV{sub 0.005}.

  6. Surface modification of biomedical AISI 316L stainless steel with zirconium carbonitride coatings

    NASA Astrophysics Data System (ADS)

    Wang, L.; Zhao, X.; Ding, M. H.; Zheng, H.; Zhang, H. S.; Zhang, B.; Li, X. Q.; Wu, G. Y.

    2015-06-01

    In the paper, by using radio frequency (rf) magnetron sputtering method, a zirconium carbonitride coating was produced on AISI 316L austenitic stainless steel. The influence of substrate temperature (Ts) on microstructure, mechanical properties, corrosion resistance and hemocompatibility were then investigated. XRD and TEM results revealed that the zirconium carbonitride coatings were almost amorphous when Ts was below 400°C, while nanostructured Zr2CN was formed at Ts of 400 °C. The nanocrystalline formation resulted in a significant increase in the nanohardness of zirconium carbonitride coatings from 17 GPa to over 32 GPa. Electrochemical testing showed that the stable zirconium carbonitride coating had improved the corrosion resistance of AISI 316L stainless steel substrate material. The characterization of platelet adhesion indicated that the zirconium carbonitride coatings presented better hemocompatibility when Ts varied from 25 °C to more than 200 °C, which may be due to the lower surface roughness, interfacial tension and the rate γsd /γsp , where γsd and γsp are the disperse component and polar component of the surface, respectively.

  7. UV-Stressed Daphnia pulex Increase Fitness through Uptake of Vitamin D3

    PubMed Central

    Walling, Kelly; Wilbert, Steven A.; Catlin, Diane M.; Monaghan, Cailin E.; Hlynchuk, Sofiya; Meehl, Pamela G.; Resch, Lauren N.; Carrera, J. Valerie; Bowles, Stephanie M.; Clark, Michael D.

    2015-01-01

    Ultraviolet radiation is known to be highly variable in aquatic ecosystems. It has been suggested that UV-exposed organisms may demonstrate enough phenotypic plasticity to maintain the relative fitness of natural populations. Our long-term objective is to determine the potential photoprotective effect of vitamin D3 on Daphnia pulex exposed to acute or chronic UV radiation. Herein we report our initial findings in this endeavor. D. pulex survival and reproduction (fitness) was monitored for 5 d as a proof of concept study. Significantly higher fitness was observed in the D. pulex with D3 than those without (most extreme effects observed were 0% survival in the absence of D3 and 100% with 10 ppm D3). Vitamin D3 was isolated from the culture media, the algal food (Pseudokirchneriella), and the D. pulex and quantified using high performance liquid chromatography (HPLC). Vitamin D3 was fluorescently labeled using a phenothiazinium dye and added to cultures of D. pulex. Images demonstrating the uptake of D3 into the tissues and carapace of the D. pulex were acquired. Our initial findings suggest a positive role for D3 in ecosystems as both UV-stressed algae and Daphnia sequester D3, and D. pulex demonstrate increased fitness in the presence of D3. PMID:26147286

  8. Surface fatigue life and failure characteristics of EX-53, CBS 1000M, and AISI 9310 gear materials

    NASA Technical Reports Server (NTRS)

    Townsend, D. P.

    1985-01-01

    Spur gear endurance tests and rolling-element surface fatigue tests are conducted to investigate EX-53 and CBS 1000M steels for use as advanced application gear materials, to determine their endurance characteristics, and to compare the results with the standard AISI 9310 gear material. The gear pitch diameter is 8.89 cm (3.50 in). Gear test conditions are an oil inlet temperature of 320 K (116 F), an oil outlet temperature of 350 K (170 F), a maximum Hertz stress of 1.71 GPa (248 ksi), and a speed of 10,000 rpm. Bench-type rolling-element fatigue tests are conducted at ambient temperature with a bar specimen speed of 12,500 rpm and a maximum Hertz stress of 4.83 GPa (700 ksi). The EX-53 test gears have a surface fatigue life of twice that of the AISI 9310 spur gears. The CBS 1000M test gears have a surface fatigue life of more than twice that of the AISI 9310 spur gears. However, the CBS 1000M gears experience a 30-percent tooth fracture failure which limits its use as a gear material. The rolling-contact fatigue lines of RC bar specimens of EX-53 and ASISI 9310 are approximately equal. However, the CBS 1000M RC specimens have a surface fatigue life of about 50 percent that of the AISI 9310.

  9. Studies on the determination of surface deuterium in AISI 1062, 4037, and 4140 steels by secondary ion mass spectrometry

    NASA Astrophysics Data System (ADS)

    Sastri, V. S.; Donepudi, V. S.; McIntyre, N. S.; Johnston, D.; Revie, R. W.

    1988-12-01

    The concentration of deuterium at the surface of cathodically charged high strength steels AISI 1062, 4037, and 4140 has been determined by secondary ion mass spectrometry (SIMS). The beneficial effects of pickling in NAP (a mixture of nitric, acetic, and phosphoric acids) to remove surfacebound deuterium have been observed.

  10. Vitamin D(3) synthesis in the entire skin surface of dairy cows despite hair coverage.

    PubMed

    Hymøller, L; Jensen, S K

    2010-05-01

    How hair-coated animals such as dairy cows synthesize endogenous vitamin D(3) during exposure to summer sunlight has been unclear since vitamin D(3) and its relation to sunlight was discovered. The fur of fur-bearing animals is thought to be comparable to clothing in humans, which prevents vitamin D(3) synthesis in the skin during exposure to sunlight. Different scenarios have been suggested but never tested in cows; for example, that vitamin D(3) is synthesized from sebum on the hair and ingested by cows during grooming or that body areas such as the udder and muzzle that have scant hair exclusively produce the vitamin. To test different scenarios, 16 Danish Holstein dairy cows were subjected to 4 degrees of coverage of their bodies with fabric that prevented vitamin D(3) synthesis in the covered skin areas. The treatments were horse blanket (cows fitted with horse blankets), udder cover (cows fitted with udder covers, horse blanket+udder cover (cows fitted with both horse blankets and udder covers), and natural (cows without any coverage fitted). The cows were let out to pasture daily between 1000 and 1500h for 4 wk in July and August 2009. Blood samples were collected 15 times during the study and analyzed for content of 25-hydroxyvitamin D(3) [25(OH)D(3)] indicative of the animals' vitamin D(3) status. Results showed that uncovered cows had a higher 25(OH)D(3) concentration in plasma after 28 d of access to sunlight compared with covered cows and that the plasma concentration of 25(OH)D(3) was strongly inversely correlated to the body surface area covered. These results are consistent with findings in humans, wherein the vitamin D(3) status of different individuals was inversely proportional to the amount of clothing worn during exposure to artificial sunlight. Hence, it appears that human clothing and cow hair are not comparable with respect to prevention of vitamin D(3) synthesis and that cows, like humans, synthesize vitamin D(3) evenly over their body

  11. Use of 1 alpha-hydroxyvitamin D3 to prevent bovine parturient paresis. VI. Concentrations of vitamin D metabolites and vitamin D3 equivalence in milk.

    PubMed

    Bar, A; Sachs, M; Perlman, R

    1986-11-01

    Concentration of vitamin D metabolites was determined in the milk of control and 1 alpha-hydroxyvitamin D3-injected (700 micrograms) cows that calved 36 to 43 h after treatment. Milk samples were taken 60 h after calving. Concentrations of vitamin D, 25-hydroxyvitamin D, 24,25-dihydroxyvitamin D, and 1,25-dihydroxyvitamin D in milk of the control cows were 372 +/- 24, 264 +/- 68, 68 +/- 26, and 21 +/- 3 ng/L, respectively. Concentrations of vitamin D metabolites in the milk of the treated cows did not differ significantly from those of controls. Concentration of 1 alpha-hydroxyvitamin D3 in milk of treated cows was less than 20 ng/L. In a second experiment, cows were injected twice, at 72-h intervals, with 350 micrograms 1 alpha-hydroxyvitamin D3. Milk was taken 60 h after parturition from cows that calved 37 to 60 h after the second injection. The vitamin D3 equivalence of the milk was 40 +/- 3 IU/L. Results indicate that injection of 700 micrograms 1 alpha-hydroxyvitamin D3 did not affect the concentration of vitamin D metabolites or the vitamin D3 equivalence of milk taken 60 h after calving. PMID:3027149

  12. Febrile/cold agglutinins

    MedlinePlus

    ... diagnose certain infections and find the cause of hemolytic anemia (a type of anemia that occurs when red ... or cold agglutinins can help explain why the hemolytic anemia is occurring and direct treatment.

  13. The role of central dopamine D3 receptors in drug addiction: a review of pharmacological evidence

    PubMed Central

    Heidbreder, Christian A.; Gardner, Eliot L.; Xi, Zheng-Xiong; Thanos, Panayotis K.; Mugnaini, Manolo; Hagan, Jim J.; Ashby, Charles R.

    2013-01-01

    The cDNA for the dopamine D3 receptor was isolated and characterized in 1990. Subsequent studies have indicated that D3 receptors, as well as D3 receptor mRNA, are primarily localized in limbic regions in mammals. This finding led to the postulate that D3 receptors may be involved in drug dependence and addiction. However, this hypothesis has been difficult to test due to the lack of compounds with high selectivity for central D3 receptors. The interpretation of results from studies using mixed D2/D3 agonists and/or antagonists is problematic because these agents have low selectivity for D3 over D2 receptors and it is likely that their actions are primarily related to D2 receptor antagonism and possibly interaction with other neurotransmitter receptors. Currently, with the synthesis and characterization of new highly selective D3 receptor antagonists such as SB-277011-A this difficulty has been surmounted. The purpose of the present article is to review, for the first time, the effects of various putative D3 receptor selective compounds in animal models of drug dependence and addiction. The results obtained with highly selective D3 receptor antagonists such as SB-277011-A, SB-414796, and NGB-2904 indicate that central D3 receptors may play an important role in drug-induced reward, drug-taking, and cue-, drug-, and stress-induced reinstatement of drug-seeking behavior. Provided these results can be extrapolated to human drug addicts, they suggest that selective DA D3 receptor antagonists may prove effective as potential pharmacotherapeutic agents to manage drug dependence and addiction. PMID:15960988

  14. Pharmacological targeting of dopamine D3 receptors: Possible clinical applications of selective drugs.

    PubMed

    Pich, Emilio Merlo; Collo, Ginetta

    2015-09-01

    Dopamine D3 receptors have been pharmacologically engaged in humans since the development of the first antipsychotics and ergot-derivative dopamine (DA) agonists, even without knowing it. These agents were generally non-selective, developed primarily to target D2 receptors. In the last 10 years the understanding of the clinical implication of D3 receptors has been progressing also due to the identification of D3 gene polymorphisms, the use of more selective PET ligands such as [(11)C]-(+)-PHNO and the learning regarding the clinical use of the D3-preferential D2/D3 agonists ropinirole and pramipexole. A new specific neuroplasticity role of D3 receptor regarding dendrite arborisation outgrowth in dopaminergic neurons was also proposed to support, at least in part, the slowing of disease observed in subjects with Parkinson׳s Disease treated with DA agonists. Similar mechanisms could be at the basis of the antidepressant-like effects observed with DA agonists when co-administered with standard of care. Severe adverse event occurring with the use of anti-parkinsonian DA agonists in predisposed subjects, i.e., impulse control disorders, are now suggested to be putatively related to overactive D3 receptors. Not surprisingly, blockade of D3 receptors was proposed as treatment for addictive disorders, a goal that could be potentially achieved by repositioning buspirone, an anxiolytic drug with D3-preferential antagonistic features, or with novel selective D3 antagonists or partial agonists currently in development for schizophrenia. At the moment ABT-925 is the only selective D3 antagonist tested in schizophrenic patients in Phase II, showing an intriguing cognitive enhancing effects supported by preclinical data. Finally, exploratory pharmacogenetic analysis suggested that ABT-925 could be effective in a subpopulation of patients with a polymorphism on the D3 receptor, opening to a possible personalised medicine approach. PMID:26298833

  15. Recent methods for measuring dopamine D3 receptor occupancy in vivo: importance for drug development.

    PubMed

    Le Foll, Bernard; Wilson, Alan A; Graff, Ariel; Boileau, Isabelle; Di Ciano, Patricia

    2014-01-01

    There is considerable interest in developing highly selective dopamine (DA) D3 receptor ligands for a variety of mental health disorders. DA D3 receptors have been implicated in Parkinson's disease, schizophrenia, anxiety, depression, and substance use disorders. The most concrete evidence suggests a role for the D3 receptor in drug-seeking behaviors. D3 receptors are a subtype of D2 receptors, and traditionally the functional role of these two receptors has been difficult to differentiate. Over the past 10-15 years a number of compounds selective for D3 over D2 receptors have been developed. However, translating these findings into clinical research has been difficult as many of these compounds cannot be used in humans. Therefore, the functional data involving the D3 receptor in drug addiction mostly comes from pre-clinical studies. Recently, with the advent of [(11)C]-(+)-PHNO, it has become possible to image D3 receptors in the human brain with increased selectivity and sensitivity. This is a significant innovation over traditional methods such as [(11)C]-raclopride that cannot differentiate between D2 and D3 receptors. The use of [(11)C]-(+)-PHNO will allow for further delineation of the role of D3 receptors. Here, we review recent evidence that the role of the D3 receptor has functional importance and is distinct from the role of the D2 receptor. We then introduce the utility of analyzing [(11)C]-(+)-PHNO binding by region of interest. This novel methodology can be used in pre-clinical and clinical approaches for the measurement of occupancy of both D3 and D2 receptors. Evidence that [(11)C]-(+)-PHNO can provide insights into the function of D3 receptors in addiction is also presented. PMID:25071579

  16. Noncalcemic actions of 1,25-dihydroxyvitamin D3 and clinical applications.

    PubMed

    Holick, M F

    1995-08-01

    Vitamin D is absolutely essential for the maintenance of a healthy skeleton. Without vitamin D, children develop rickets and adults exacerbate their osteoporosis and develop osteomalacia. Casual exposure to sunlight is the major source of vitamin D for most people. During exposure to sunlight, ultraviolet B photons photolyze cutaneous stores of 7-dehydrocholesterol to previtamin D3. Previtamin D3 undergoes a thermal isomerization to form vitamin D3. Increased skin pigmentation, changes in latitude, time of day, sunscreen use, and aging can have a marked influence on the cutaneous production of vitamin D3. Once vitamin D3 is formed in the skin or ingested in the diet, it must be hydroxylated in the liver and kidney to 1,25-dihydroxyvitamin D3 [1,25(OH)2D3]. It is now recognized that a wide variety of tissues and cells, both related to calcium metabolism and unrelated to calcium metabolism, are target sites for 1,25(OH)2D3. 1,25(OH)2D3 stimulates intestinal calcium absorption and mobilizes stem cells to mobilize calcium stores from bone. Noncalcemic tissues that possess receptors for 1,25(OH)2D3 respond to the hormone in a variety of ways. Of great interest is that 1,25(OH)2D3 is a potent antiproliferative and prodifferentiation mediator. As a result, 1,25(OH)2D3 and its analogs have wide clinical application in such diverse clinical disorders as rheumatoid and psoriatic arthritis; diabetes mellitus type I; hypertension; cardiac arrhythmias; seizure disorders; cancers of the breast, prostate, and colon; some leukemias and myeloproliferative disorders; chemotherapy-induced hair loss; and skin rejuvenation as well as skin diseases like psoriasis and ichthyosis. PMID:8579891

  17. 1alpha,25-dihydroxyvitamin D3 rapidly inhibits fibroblast-induced collagen gel contraction.

    PubMed

    Greiling, D; Thieroff-Ekerdt, R

    1996-06-01

    1alpha,25-Dihydroxyvitamin D3 (1,25-D3) inhibits the proliferation of fibroblasts in vitro in monolayer culture. We investigated the effect of 1,25-D3 on normal murine and human fibroblasts cultured in collagen type I gels, which more closely resembles the in vivo situation in the dermis. In this culture system 1,25-D3 had no effect on fibroblast proliferation; however, the fibroblast-induced collagen gel contraction was inhibited in a time- and concentration-dependent manner in the nanomolar concentration range. 25-Hydroxyvitamin D3 and 24,25-dihydroxyvitamin D3 were inactive. 1,25-D3 had no effect in fibroblasts lacking a functional vitamin D receptor. Pretreatment of fibroblasts in monolayer culture for 5 min was sufficient to trigger the inhibition of collagen gel contraction. Nifedipine increased collagen gel contraction and counteracted the effect of 1,25-D3. The inhibition of collagen gel contraction by 1,25-D3 is supposed to be mediated by the vitamin D receptor because a functional vitamin D receptor is required, and vitamin D metabolites with low affinity to the vitamin D receptor were inactive. Brief pretreatment of fibroblasts was sufficient to trigger the inhibitory effect of 1,25-D3, suggesting a nongenomic effect. A genomic mode of action could not be ruled out, however, because the inhibition was first measured after 24 h. The antagonism of the calcium channel antagonist nifedipine probably represents the sum of two opposite effects rather than supporting evidence for a nongenomic mode of action of 1,25-D3. In conclusion, 1,25-D3 has a specific and rapidly triggered inhibitory effect on fibroblast-induced collagen gel contraction. PMID:8752663

  18. Characterization of the translocation process of vitamin D3 from the skin into the circulation.

    PubMed

    Tian, X Q; Chen, T C; Lu, Z; Shao, Q; Holick, M F

    1994-08-01

    The cutaneous synthesis of vitamin D3 and the subsequent translocation of vitamin D3 into the circulation are two key steps in the vitamin D endocrine system. To study the kinetic aspects of cutaneous synthesis and translocation of vitamin D3, both in vitro and in vivo chicken models have been developed. To assess the capacity of chicken skin to generate vitamin D3, the concentrations of 7-dehydrocholesterol (7-DHC) in different skin areas were determined. It was found that the highest concentration of 7-DHC was in the leg skin (3524 +/- 937 ng cm-2), which was about 30 times greater than that in the back (120 +/- 62 ng cm-2). Whole body exposure of chickens to UV-B radiation (0.5 J cm-2) resulted in the production of previtamin D3 (preD3) in the skin of the legs and feet (43 +/- 7 and 54 +/- 17 ng cm-2, respectively), whereas no preD3 was detected in the back skin. In vitro, at 40 C, the forward (k1) and reverse (k2) rate constants of the preD3<-->vitamin D3 reaction in the leg skin were greatly increased compared to those in n-hexane (k1, 0.367 vs. 0.0369 h-1; k2, 0.042 vs. 0.0059 h-1). In vivo, the determined rate constants k1, k2, and k3 for the consecutive reactions preD3<-->vitamin D3-->vitamin D3 were 0.257, 0.034, and 0.114 h-1, respectively. To evaluate the circulating concentration of vitamin D3 in response to UV-B radiation, chicken legs were irradiated. The time course revealed a 4-fold increase in the circulating concentration of vitamin D3, with a peak about 30 h postradiation. No appreciable amount of preD3 could be detected in the circulation in the early hours after UV-B radiation, suggesting the existence of a process responsible for the specific translocation of vitamin D3 from the skin into the circulation. PMID:8033813

  19. Effects of Solanum malacoxylon extract on rachitic chicks. Comparative study with vitamin D3.

    PubMed

    Cañas, F M; Ortiz, O E; Asteggiano, C A; Pereira, R D

    1977-10-20

    A comparative study of the effects of vitamin D3 and of a partially purified extract of Solanum malacoxylon has been carried out in rachitic chicks. Vitamin D3 and Solanum malacoxylon increased intestinal calcium absorption and serum calcium levels. They normalized the bone water and ash content. Vitamin D3 produced an increase of serum phosphate while Solanum malacoxylon further decreased the already low phosphate values. Vitamin D3 significantly increased the body weight increment of rachitic chicks, but Solanum malacoxylon did not. It appears that Solanum malacoxylon duplicates certain actions of vitamin D but lacks its phosphate-regulating and growth-promoting actions. PMID:198068

  20. The potential role of dopamine D3 receptor neurotransmission in cognition

    PubMed Central

    Nakajima, Shinichiro; Gerretsen, Philip; Takeuchi, Hiroyoshi; Caravaggio, Fernando; Chow, Tiffany; Le Foll, Bernard; Mulsant, Benoit; Pollock, Bruce; Graff-Guerrero, Ariel

    2013-01-01

    Currently available treatments have limited pro-cognitive effects for neuropsychiatric disorders, such as schizophrenia, Parkinson’s disease and Alzheimer’s disease. The primary objective of this work is to review the literature on the role of dopamine D3 receptors in cognition, and propose dopamine D3 receptor antagonists as possible cognitive enhancers for neuropsychiatric disorders. A literature search was performed to identify animal and human studies on D3 receptors and cognition using PubMed, MEDLINE and EMBASE. The search terms included “dopamine D3 receptor” and “cognition”. The literature search identified 164 articles. The results revealed: (1) D3 receptors are associated with cognitive functioning in both healthy individuals and those with neuropsychiatric disorders; (2) D3 receptor blockade appears to enhance while D3 receptor agonism seems to impair cognitive function, including memory, attention, learning, processing speed, social recognition and executive function independent of age; and (3) D3 receptor antagonists may exert their pro-cognitive effect by enhancing the release of acetylcholine in the prefrontal cortex, disinhibiting the activity of dopamine neurons projecting to the nucleus accumbens or prefrontal cortex, or activating CREB signaling in the hippocampus. These findings suggest that D3 receptor blockade may enhance cognitive performance in healthy individuals and treat cognitive dysfunction in individuals with a neuropsychiatric disorder. Clinical trials are needed to confirm these effects. PMID:23791072

  1. Effects of repeated treatment with the dopamine D2/D3 receptor partial agonist aripiprazole on striatal D2/D3 receptor availability in monkeys

    PubMed Central

    Czoty, Paul W.; Gage, H. Donald; Garg, Pradeep K.; Garg, Sudha; Nader, Michael A.

    2013-01-01

    Rationale Chronic treatment with dopamine (DA) receptor agonists and antagonists can differentially affect measures of DA D2/D3 receptor number and function, but the effects of chronic treatment with a partial D2/D3 receptor agonist are not clear. Objective We used a within-subjects design in male cynomolgus monkeys to determine the effects of repeated (17-day) treatment with the D2/D3 receptor partial agonist aripiprazole (ARI; 0.03 mg/kg and 0.1 mg/kg i.m.) on food-reinforced behavior (n=5) and on D2/D3 receptor availability as measured with positron emission tomography (PET; n=9). Methods Five monkeys responded under a fixed-ratio 50 schedule of food reinforcement and D2/D3 receptor availability was measured before and four days after ARI treatment using PET and the D2/D3 receptor-selective radioligand [18F]fluoroclebopride (FCP). Four additional monkeys were studied using [11C]raclopride and treated sequentially with each dose of ARI for 17 days. Results ARI decreased food-maintained responding with minimal evidence of tolerance. Repeated ARI administration increased FCP and raclopride distribution volume ratios (DVRs) in the caudate nucleus and putamen in most monkeys, but decreases were observed in monkeys with the highest baseline DVRs. Conclusions The results indicate that repeated treatment with a low efficacy DA receptor partial agonist produces effects on brain D2/D3 receptor availability that are qualitatively different from those of both high-efficacy receptor agonists and antagonists, and suggest that the observed individual differences in response to ARI treatment may reflect its partial agonist activity. PMID:24077804

  2. Teaching in a Cold Environment.

    ERIC Educational Resources Information Center

    Ewert, Alan

    1979-01-01

    Designed to help teachers deal with students in a cold environment, this article explains cold physiology and fundamental laws of heat; describes 14 common cold injuries and their current treatment; and lists a number of useful teaching techniques for cold environments. (SB)

  3. Teaching in a Cold Environment.

    ERIC Educational Resources Information Center

    Ewert, Alan

    Instructors who teach outdoors in an environment so cold as to cause injury must satisfy program objectives while avoiding cold injury to themselves and students, help students focus on learning instead of discomfort, and alleviate some students' intense fear of the cold. Dealing with the cold successfully requires a thorough knowledge of:…

  4. Serum 25-Hydroxyvitamin D3 and Mammography Density among Mexican Women.

    PubMed

    Amadou, Amina; Biessy, Carine; Rinaldi, Sabina; Fedirko, Veronika; Assi, Nada; Lajous, Martin; Ortiz-Panozo, Eduardo; Yunes, Elsa; Lopez-Ridaura, Ruy; Torres-Mejia, Gabriela; Romieu, Isabelle

    2016-01-01

    Low circulating levels of vitamin D and high mammographic density (MD) have been associated with higher risk of breast cancer. Although some evidence suggested an inverse association between circulating vitamin D and MD, no studies have investigated this association among Mexican women. We examined whether serum 25-hydroxyvitamin D3 [25(OH)D3] levels were associated with MD in a cross-sectional study nested within the large Mexican Teacher's Cohort. This study included 491 premenopausal women with a mean age of 42.9 years. Serum 25(OH)D3 levels were measured by liquid chromatography/tandem mass spectrometry. Linear regression and non-linear adjusted models were used to estimate the association of MD with serum 25(OH)D3. Median serum 25(OH)D3 level was 27.3 (23.3-32.8) (ng/ml). Forty one (8%) women had 25(OH)D3 levels in the deficient range (< 20 ng/ml). Body mass index (BMI) and total physical activity were significantly correlated with 25(OH)D3 (r = -0.109, P = 0.019 and r = 0.095, P = 0.003, respectively). In the multivariable linear regression, no significant association was observed between 25(OH)D3 levels and MD overall. However, in stratified analyses, higher serum 25(OH)D3 levels (≥27.3 ng/ml) were significantly inversely associated with percent MD among women with BMI below the median (β = -0.52, P = 0.047). Although no significant association was observed between serum 25(OH)D3 and percent MD in the overall population, specific subgroups of women may benefit from higher serum 25(OH)D3 levels. PMID:27564705

  5. Regulation and functional characterization of a rat recombinant dopamine D3 receptor.

    PubMed

    Cox, B A; Rosser, M P; Kozlowski, M R; Duwe, K M; Neve, R L; Neve, K A

    1995-09-01

    We stably expressed a rat D3 receptor cDNA in C6 glioma cells (C6-D3 cells), quantifying receptor expression with the radioligands [125I]epidepride (KD = 0.1 nM) and [3H]spiperone (KD = 0.7 nM). As reported previously for D2 receptors, quinpirole induced a 9-16% increase in the rate of extracellular acidification by C6-D3 cells. The acidification was inhibited by epidepride and by the Na+/H+ antiporter inhibitors, amiloride and methylisobutylamiloride, but pertussis toxin treatment had no effect on quinpirole-induced extracellular acidification. These data suggest that D3 receptor stimulation of Na+/H+ exchange in C6 glioma cells is not mediated by the pertussis toxin-sensitive G proteins, Gi or G(o). Overnight treatment of C6-D3 cells with N-propylnorapomorphine, dopamine, or quinpirole resulted in large concentration-dependent increases (up to 500%) in the density of D3 receptors on membranes prepared from the cells. Antagonists had smaller, variable effects on the density of D3 receptors in C6-D3 cells, except for domperidone, which significantly increased the density of D3 receptors. Treatment with pertussis toxin had no effect on the agonist-induced receptor up-regulation, indicating that an interaction with pertussis toxin-sensitive G proteins was not required. Densitometry analysis of Northern blots of RNA prepared from C6-D3 cells showed no significant N-propylnorapomorphine-induced increase in D3 receptor message. Treatment with cycloheximide, however, completely prevented receptor up-regulation by N-propylnorapomorphine. Pretreatment of C6-D2 cells with 10 microM DA resulted in a substantial heterologous sensitization, in which isoproterenol-stimulated adenylyl cyclase activity was enhanced more than twofold.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8525456

  6. Vitamin D3 pretreatment regulates renal inflammatory responses during lipopolysaccharide-induced acute kidney injury

    PubMed Central

    Xu, Shen; Chen, Yuan-Hua; Tan, Zhu-Xia; Xie, Dong-Dong; Zhang, Cheng; Zhang, Zhi-Hui; Wang, Hua; Zhao, Hui; Yu, De-Xin; Xu, De-Xiang

    2015-01-01

    Vitamin D receptor (VDR) is highly expressed in human and mouse kidneys. Nevertheless, its functions remain obscure. This study investigated the effects of vitamin D3 (VitD3) pretreatment on renal inflammation during lipopolysaccharide (LPS)-induced acute kidney injury. Mice were intraperitoneally injected with LPS. In VitD3 + LPS group, mice were pretreated with VitD3 (25 μg/kg) at 48, 24 and 1 h before LPS injection. As expected, an obvious reduction of renal function and pathological damage was observed in LPS-treated mice. VitD3 pretreatment significantly alleviated LPS-induced reduction of renal function and pathological damage. Moreover, VitD3 pretreatment attenuated LPS-induced renal inflammatory cytokines, chemokines and adhesion molecules. In addition, pretreatment with 1,25(OH)2D3, the active form of VitD3, alleviated LPS-induced up-regulation of inflammatory cytokines and chemokines in human HK-2 cells, a renal tubular epithelial cell line, in a VDR-dependent manner. Further analysis showed that VitD3, which activated renal VDR, specifically repressed LPS-induced nuclear translocation of nuclear factor kappa B (NF-κB) p65 subunit in the renal tubules. LPS, which activated renal NF-κB, reciprocally suppressed renal VDR and its target gene. Moreover, VitD3 reinforced the physical interaction between renal VDR and NF-κB p65 subunit. These results provide a mechanistic explanation for VitD3-mediated anti-inflammatory activity during LPS-induced acute kidney injury. PMID:26691774

  7. Reduced sleep duration mediates decreases in striatal D2/D3 receptor availability in cocaine abusers

    PubMed Central

    Wiers, C E; Shumay, E; Cabrera, E; Shokri-Kojori, E; Gladwin, T E; Skarda, E; Cunningham, S I; Kim, S W; Wong, T C; Tomasi, D; Wang, G-J; Volkow, N D

    2016-01-01

    Neuroimaging studies have documented reduced striatal dopamine D2/D3 receptor (D2/D3R) availability in cocaine abusers, which has been associated with impaired prefrontal activity and vulnerability for relapse. However, the mechanism(s) underlying the decreases in D2/D3R remain poorly understood. Recent studies have shown that sleep deprivation is associated with a downregulation of striatal D2/D3R in healthy volunteers. As cocaine abusers have disrupted sleep patterns, here we investigated whether reduced sleep duration mediates the relationship between cocaine abuse and low striatal D2/D3R availability. We used positron emission tomography with [11C]raclopride to measure striatal D2/D3R availability in 24 active cocaine abusers and 21 matched healthy controls, and interviewed them about their daily sleep patterns. Compared with controls, cocaine abusers had shorter sleep duration, went to bed later and reported longer periods of sleep disturbances. In addition, cocaine abusers had reduced striatal D2/D3R availability. Sleep duration predicted striatal D2/D3R availability and statistically mediated the relationship between cocaine abuse and striatal D2/D3R availability. These findings suggest that impaired sleep patterns contribute to the low striatal D2/D3R availability in cocaine abusers. As sleep impairments are similarly observed in other types of substance abusers (for example, alcohol and methamphetamine), this mechanism may also underlie reductions in D2/D3R availability in these groups. The current findings have clinical implications suggesting that interventions to improve sleep patterns in cocaine abusers undergoing detoxification might be beneficial in improving their clinical outcomes. PMID:26954979

  8. Vitamin D3 pretreatment regulates renal inflammatory responses during lipopolysaccharide-induced acute kidney injury.

    PubMed

    Xu, Shen; Chen, Yuan-Hua; Tan, Zhu-Xia; Xie, Dong-Dong; Zhang, Cheng; Zhang, Zhi-Hui; Wang, Hua; Zhao, Hui; Yu, De-Xin; Xu, De-Xiang

    2015-01-01

    Vitamin D receptor (VDR) is highly expressed in human and mouse kidneys. Nevertheless, its functions remain obscure. This study investigated the effects of vitamin D3 (VitD3) pretreatment on renal inflammation during lipopolysaccharide (LPS)-induced acute kidney injury. Mice were intraperitoneally injected with LPS. In VitD3 + LPS group, mice were pretreated with VitD3 (25 μg/kg) at 48, 24 and 1 h before LPS injection. As expected, an obvious reduction of renal function and pathological damage was observed in LPS-treated mice. VitD3 pretreatment significantly alleviated LPS-induced reduction of renal function and pathological damage. Moreover, VitD3 pretreatment attenuated LPS-induced renal inflammatory cytokines, chemokines and adhesion molecules. In addition, pretreatment with 1,25(OH)2D3, the active form of VitD3, alleviated LPS-induced up-regulation of inflammatory cytokines and chemokines in human HK-2 cells, a renal tubular epithelial cell line, in a VDR-dependent manner. Further analysis showed that VitD3, which activated renal VDR, specifically repressed LPS-induced nuclear translocation of nuclear factor kappa B (NF-κB) p65 subunit in the renal tubules. LPS, which activated renal NF-κB, reciprocally suppressed renal VDR and its target gene. Moreover, VitD3 reinforced the physical interaction between renal VDR and NF-κB p65 subunit. These results provide a mechanistic explanation for VitD3-mediated anti-inflammatory activity during LPS-induced acute kidney injury. PMID:26691774

  9. Serum 25–Hydroxyvitamin D3 and Mammography Density among Mexican Women

    PubMed Central

    Amadou, Amina; Biessy, Carine; Rinaldi, Sabina; Fedirko, Veronika; Assi, Nada; Lajous, Martin; Ortiz-Panozo, Eduardo; Yunes, Elsa; Lopez-Ridaura, Ruy; Torres-Mejia, Gabriela; Romieu, Isabelle

    2016-01-01

    Low circulating levels of vitamin D and high mammographic density (MD) have been associated with higher risk of breast cancer. Although some evidence suggested an inverse association between circulating vitamin D and MD, no studies have investigated this association among Mexican women. We examined whether serum 25−hydroxyvitamin D3 [25(OH)D3] levels were associated with MD in a cross-sectional study nested within the large Mexican Teacher's Cohort. This study included 491 premenopausal women with a mean age of 42.9 years. Serum 25(OH)D3 levels were measured by liquid chromatography/tandem mass spectrometry. Linear regression and non-linear adjusted models were used to estimate the association of MD with serum 25(OH)D3. Median serum 25(OH)D3 level was 27.3 (23.3–32.8) (ng/ml). Forty one (8%) women had 25(OH)D3 levels in the deficient range (< 20 ng/ml). Body mass index (BMI) and total physical activity were significantly correlated with 25(OH)D3 (r = −0.109, P = 0.019 and r = 0.095, P = 0.003, respectively). In the multivariable linear regression, no significant association was observed between 25(OH)D3 levels and MD overall. However, in stratified analyses, higher serum 25(OH)D3 levels (≥27.3 ng/ml) were significantly inversely associated with percent MD among women with BMI below the median (β = −0.52, P = 0.047). Although no significant association was observed between serum 25(OH)D3 and percent MD in the overall population, specific subgroups of women may benefit from higher serum 25(OH)D3 levels. PMID:27564705

  10. Reduced sleep duration mediates decreases in striatal D2/D3 receptor availability in cocaine abusers.

    PubMed

    Wiers, C E; Shumay, E; Cabrera, E; Shokri-Kojori, E; Gladwin, T E; Skarda, E; Cunningham, S I; Kim, S W; Wong, T C; Tomasi, D; Wang, G-J; Volkow, N D

    2016-01-01

    Neuroimaging studies have documented reduced striatal dopamine D2/D3 receptor (D2/D3R) availability in cocaine abusers, which has been associated with impaired prefrontal activity and vulnerability for relapse. However, the mechanism(s) underlying the decreases in D2/D3R remain poorly understood. Recent studies have shown that sleep deprivation is associated with a downregulation of striatal D2/D3R in healthy volunteers. As cocaine abusers have disrupted sleep patterns, here we investigated whether reduced sleep duration mediates the relationship between cocaine abuse and low striatal D2/D3R availability. We used positron emission tomography with [(11)C]raclopride to measure striatal D2/D3R availability in 24 active cocaine abusers and 21 matched healthy controls, and interviewed them about their daily sleep patterns. Compared with controls, cocaine abusers had shorter sleep duration, went to bed later and reported longer periods of sleep disturbances. In addition, cocaine abusers had reduced striatal D2/D3R availability. Sleep duration predicted striatal D2/D3R availability and statistically mediated the relationship between cocaine abuse and striatal D2/D3R availability. These findings suggest that impaired sleep patterns contribute to the low striatal D2/D3R availability in cocaine abusers. As sleep impairments are similarly observed in other types of substance abusers (for example, alcohol and methamphetamine), this mechanism may also underlie reductions in D2/D3R availability in these groups. The current findings have clinical implications suggesting that interventions to improve sleep patterns in cocaine abusers undergoing detoxification might be beneficial in improving their clinical outcomes. PMID:26954979

  11. Identification of key residues involved in the activation and signaling properties of dopamine D3 receptor.

    PubMed

    Kota, Kokila; Kuzhikandathil, Eldo V; Afrasiabi, Milad; Lacy, Brett; Kontoyianni, Maria; Crider, A Michael; Song, Daniel

    2015-09-01

    The dopamine D3 receptor exhibits agonist-dependent tolerance and slow response termination (SRT) signaling properties that distinguish it from the closely-related D2 receptors. While amino acid residues important for D3 receptor ligand binding have been identified, the residues involved in activation of D3 receptor signaling and induction of signaling properties have not been determined. In this paper, we used cis and trans isomers of a novel D3 receptor agonist, 8-OH-PBZI, and site-directed mutagenesis to identify key residues involved in D3 receptor signaling function. Our results show that trans-8-OH-PBZI, but not cis-8-OH-PBZI, elicit the D3 receptor tolerance and SRT properties. We show that while both agonists require a subset of residues in the orthosteric binding site of D3 receptors for activation of the receptor, the ability of the two isomers to differentially induce tolerance and SRT is mediated by interactions with specific residues in the sixth transmembrane helix and third extracellular loop of the D3 receptor. We also show that unlike cis-8-OH-PBZI, which is a partial agonist at the dopamine D2S receptor and full agonist at dopamine D2L receptor, trans-8-OH-PBZI is a full agonist at both D2S and D2L receptors. The different effect of the two isomers on D3 receptor signaling properties and D2S receptor activation correlated with differential effects of the isomers on agonist-induced mouse locomotor activity. The two isomers of 8-OH-PBZI represent novel pharmacological tools for in silico D3 and D2 receptor homology modeling and for determining the role of D3 receptor tolerance and SRT properties in signaling and behavior. PMID:26116441

  12. Condensin II Subunit dCAP-D3 Restricts Retrotransposon Mobilization in Drosophila Somatic Cells

    PubMed Central

    Schuster, Andrew T.; Sarvepalli, Kavitha; Murphy, Eain A.; Longworth, Michelle S.

    2013-01-01

    Retrotransposon sequences are positioned throughout the genome of almost every eukaryote that has been sequenced. As mobilization of these elements can have detrimental effects on the transcriptional regulation and stability of an organism's genome, most organisms have evolved mechanisms to repress their movement. Here, we identify a novel role for the Drosophila melanogaster Condensin II subunit, dCAP-D3 in preventing the mobilization of retrotransposons located in somatic cell euchromatin. dCAP-D3 regulates transcription of euchromatic gene clusters which contain or are proximal to retrotransposon sequence. ChIP experiments demonstrate that dCAP-D3 binds to these loci and is important for maintaining a repressed chromatin structure within the boundaries of the retrotransposon and for repressing retrotransposon transcription. We show that dCAP-D3 prevents accumulation of double stranded DNA breaks within retrotransposon sequence, and decreased dCAP-D3 levels leads to a precise loss of retrotransposon sequence at some dCAP-D3 regulated gene clusters and a gain of sequence elsewhere in the genome. Homologous chromosomes exhibit high levels of pairing in Drosophila somatic cells, and our FISH analyses demonstrate that retrotransposon-containing euchromatic loci are regions which are actually less paired than euchromatic regions devoid of retrotransposon sequences. Decreased dCAP-D3 expression increases pairing of homologous retrotransposon-containing loci in tissue culture cells. We propose that the combined effects of dCAP-D3 deficiency on double strand break levels, chromatin structure, transcription and pairing at retrotransposon-containing loci may lead to 1) higher levels of homologous recombination between repeats flanking retrotransposons in dCAP-D3 deficient cells and 2) increased retrotransposition. These findings identify a novel role for the anti-pairing activities of dCAP-D3/Condensin II and uncover a new way in which dCAP-D3/Condensin II influences local

  13. Evolution of magnetic phase at low aging temperature in a heavily cold-drawn stainless steel fiber

    NASA Astrophysics Data System (ADS)

    Yang, Shun-Tung; Hwang, Weng-Sing; Shyr, Tien-Wei; Cheng, I.-Lin

    2012-08-01

    The evolution of the magnetic phase upon aging at 300-520 °C in a heavily cold-drawn AISI 316L austenitic stainless steel fiber was studied using thermomagnetic analysis (TMA) and magnetic force microscopy with a heating stage. An increasing trend of magnetization from 50 °C to around 470 °C in the heating curves of TMA in austenitic stainless steels after a cold-drawing process was observed. No significant Ms temperature signal in the TMA curve at cooling indicated an increase in magnetization upon cooling period without significant phase transformation. A series of in situ magnetic force microscopy observations reveal a growth of the magnetic domain structure after aging at 300 °C for 2.5 h. Results show that the ferromagnetic increase during aging at lower annealing temperature resulted from the growth of martensite.

  14. Cold moderators at ORNL

    SciTech Connect

    Lucas, A. T.

    1997-09-01

    The Advanced Neutron Source (ANS) cold moderators were not an 'Oak Ridge first', but would have been the largest both physically and in terms of cold neutron flux. Two cold moderators were planned each 410 mm in diameter and containing about 30L of liquid deuterium. They were to be completely independent of each other. A modular system design was used to provide greater reliability and serviceability. When the ANS was terminated, up–grading of the resident High Flux Isotope Reactor (HFIR) was examined and an initial study was made into the feasibility of adding a cold source. Because the ANS design was modular, it was possible to use many identical design features. Sub-cooled liquid at 4 bar abs was initially chosen for the HFIR design concept, but this was subsequently changed to 15 bar abs to operate above the critical pressure. As in the ANS, the hydrogen will operate at a constant pressure throughout the temperature range and a completely closed loop with secondary containment was adopted. The heat load of 2 kW made the heat flux comparable with that of the ANS. Subsequent studies into the construction of cryogenic moderators for the proposed new Synchrotron Neutron source indicated that again many of the same design concepts could be used. By connecting the two cold sources together in series, the total heat load of 2 kW is very close to that of the HFIR allowing a very similar supercritical hydrogen system to be configured. The two hydrogen moderators of the SNS provide a comparable heat load to the HFIR moderator. It is subsequently planned to connect the two in series and operate from a single cold loop system, once again using supercritical hydrogen. The spallation source also provided an opportunity to re-examine a cold pellet solid methane moderator operating at 20K.

  15. Antidepressants differentially related to 1,25-(OH)2 vitamin D3 and 25-(OH) vitamin D3 in late-life depression

    PubMed Central

    Oude Voshaar, R C; Derks, W J; Comijs, H C; Schoevers, R A; de Borst, M H; Marijnissen, R M

    2014-01-01

    A low plasma 25-OH vitamin D3 level is a universal risk factor for a wide range of diseases and has also been implicated in late-life depression. It is currently unknown whether the biologically active form of vitamin D, that is, 1,25-(OH)2 vitamin D3, is also decreased in late-life depression, or whether vitamin D levels correlate with specific depression characteristics. We determined plasma 25-OH vitamin D3, 1,25-(OH)2 vitamin D3 and parathormone levels in 355 depressed older persons and 124 non-depressed comparison subjects (age⩾60 years). Psychopathology was established with the Composite International Diagnostic Interview 2.1, together with potential confounders and depression characteristics (severity, symptom profile, age of onset, recurrence, chronicity and antidepressant drug use). Adjusted for confounders, depressed patients had significantly lower levels of 25-OH vitamin D33 (Cohen's d =0.28 (95% confidence interval: 0.07–0.49), P=0.033) as well as 1,25-(OH)2 vitamin D3 (Cohen's d =0.48 (95% confidence interval: 0.27–0.70), P<0.001) than comparison subjects. Of all depression characteristics tested, only the use of tricyclic antidepressants (TCAs) was significantly correlated with lower 1,25-(OH)2 vitamin D3 levels (Cohen's d =0.86 (95% confidence interval: 0.53–1.19), P<0.001), but not its often measured precursor 25-OH vitamin D3. As vitamin D levels were significantly lower after adjustment for confounders, vitamin D might have an aetiological role in late-life depression. Differences between depressed and non-depressed subjects were largest for the biologically active form of vitamin D. The differential impact of TCAs on 25-OH vitamin D3 and 1,25-(OH)2 vitamin D3 levels suggests modulation of 1-α-hydroxylase and/or 24-hydroxylase, which may in turn have clinical implications for biological ageing mechanisms in late-life depression. PMID:24736799

  16. Improving electrochemical properties of AISI 1045 steels by duplex surface treatment of plasma nitriding and aluminizing

    NASA Astrophysics Data System (ADS)

    Haftlang, Farahnaz; Habibolahzadeh, Ali; Sohi, Mahmoud Heydarzadeh

    2015-02-01

    Improvement in electrochemical behavior of AISI 1045 steel after applying aluminum nitride coating was investigated in 3.5% NaCl solution, using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) analyses. Aluminum nitride coating was applied on the steel surface by duplex treatment of pack aluminizing and plasma nitriding. Some specimens were plasma nitrided followed by aluminizing (PN-Al), while the others were pack aluminized followed by plasma nitriding (Al-PN). Topological and structural studies of the modified surfaces were conducted using scanning electron microscope (SEM) equipped by energy dispersive X-ray spectroscope (EDS), and X-ray diffractometer (XRD). The electrochemical measurements showed that the highest corrosion and polarization (Rp) resistances were obtained in PN-Al specimens, having single phase superficial layer of AlN. Pitting mechanism was dominant reason of lower corrosion resistance in the Al-PN specimens.

  17. Pitting fatigue characteristics of AISI M-50 and super nitralloy spur gears

    NASA Technical Reports Server (NTRS)

    Townsend, D. P.; Chevalier, J. L.; Zaretsky, E. V.

    1973-01-01

    Two groups of 3.50-in. pitch-diameter spur gears, without tip relief, made from consumable-electrode vacuum-melted (CVM) AISI M-50 steel and CVM super nitralloy (5Ni-2A1) were tested under conditions which produced fatigue pitting. The M-50 gears had fatigue lives approximately 50 percent longer than the super nitralloy gears. Both groups of gears failed by classical rolling-element fatigue at the pitch circle. When the gears were overrun past initial spall formation, the spalled M-50 gear teeth failed by fatigue fracture. The M-50 material had higher wear than the super nitralloy material. Differences in fatigue life and wear were not considered statistically significant.

  18. Nitriding of AISI 4140 steel by a low energy broad ion source

    SciTech Connect

    Ochoa, E. A.; Figueroa, C. A.; Alvarez, F.

    2006-11-15

    A comprehensive study of the thermochemical nitriding process of steel AISI 4140 by low energy ion implantation (Kaufmann cell) is reported. Different times of implantation were employed and the studied samples were characterized by x-ray diffraction, in situ photoemission electron spectroscopy, scanning electron microscopy, and hardness (nanoindentation) measurements. The linear relationship between nitrogen content and hardness was verified. The structure of the nitrided layer was characterized yielding that the compound layer is formed by coarse precipitates, around small grains, constituted principally by {epsilon}-Fe{sub 2-3}N and {gamma}-Fe{sub 4}N phases and the diffusion zone is formed by fine precipitates, around big grains of the original martensitic phase, constituted principally by {gamma}-Fe{sub 4}N phase. Finally, a diffusion model for multiphase systems was applied to determine effective diffusion coefficients of nitrogen in the different phases.

  19. Structural, mechanical and tribological properties of duplex-treated AISI 5140 steel

    SciTech Connect

    Alsaran, Akguen . E-mail: aalsaran@atauni.edu.tr; Celik, Ayhan; Karakan, Mehmet

    2005-01-15

    The structure, hardness, adhesion, surface roughness and tribological properties of duplex-surface-treated (TiN/plasma nitrided), directly TiN-coated and ion-nitrided AISI 5140 steel were investigated using X-ray diffraction, SEM, optical microscopy, a microhardness tester, a scratch tester and a pin-on-disc tribotester. After the plasma nitriding process, the transition treatments were realized to evaluate the effect of the compound layer. It was found that the relative intensity line of TiN (200) and surface roughness increased, but the coating hardness and critical load (Lc) decreased with an increasing amount of {epsilon}-Fe{sub 2-3}N iron nitride in the compound layer. The better tribological properties were obtained with coatings applied on substrates, which included a large amount of {gamma}'-Fe{sub 4}N iron nitride after plasma nitriding.

  20. Study of the Sensitization on the Grain Boundary in Austenitic Stainless Steel Aisi 316

    NASA Astrophysics Data System (ADS)

    Kocsisová, Edina; Dománková, Mária; Slatkovský, Ivan; Sahul, Martin

    2014-12-01

    Intergranular corrosion (IGC) is one of the major problems in austenitic stainless steels. This type of corrosion is caused by precipitation of secondary phases on grain boundaries (GB). Precipitation of the secondary phases can lead to formation of chromium depleted zones in the vicinity of grain boundaries. Mount of the sensitization of material is characterized by the degree of sensitization (DOS). Austenitic stainless steel AISI 316 as experimental material had been chosen. The samples for the study of sensitization were solution annealed on 1100 °C for 60 min followed by water quenching and then sensitization by isothermal annealing on 700 °C and 650 °C with holding time from 15 to 600 min. Transmission electron microscopy (TEM) was used for identification of secondary phases. Electron backscattered diffraction (EBSD) was applied for characterization of grain boundary structure as one of the factors which influences on DOS.

  1. Microstructure and Texture Evolutions in AISI 1050 Steel by Flow Forming

    SciTech Connect

    Bedekar, Vikram; Pauskar, Praveen; Shivpuri, Rajiv; Howe, Jane Y

    2014-01-01

    Hot rolled and annealed AISI 1050 steel cylindrical coupons were flow formed at different levels of deformation (66% and 90% wall thickness reduction). TEM studies revealed development of ultra fine (sub) grain cell structure due to severe plastic deformation. The transverse subgrain size changed from 10 m (beginning) to 300nm (66% deformation) to 40nm (90% deformation). EBSD study revealed decreased recrystallization fraction at 90% deformation compared with 66% deformation due to orientation pinning from preferred orientation along {002} planes. No evidence of dislocation pinning or cracking was observed on any samples. The aim of the present work is to study the deformation behaviour and microstructural evolution during conventional flow forming process. The study also sheds light on the strengthening behaviour and structural changes during severe straining.

  2. Electromagnetic nondestructive evaluation of tempering process in AISI D2 tool steel

    NASA Astrophysics Data System (ADS)

    Kahrobaee, Saeed; Kashefi, Mehrdad

    2015-05-01

    The present paper investigates the potential of using eddy current technique as a reliable nondestructive tool to detect microstructural changes during the different stages of tempering treatment in AISI D2 tool steel. Five stages occur in tempering of the steel: precipitation of ɛ carbides, formation of cementite, retained austenite decomposition, secondary hardening effect and spheroidization of carbides. These stages were characterized by destructive methods, including dilatometry, differential scanning calorimetry, X-ray diffraction, scanning electron microscopic observations, and hardness measurements. The microstructural changes alter the electrical resistivity/magnetic saturation, which, in turn, influence the eddy current signals. Two EC parameters, induced voltage sensed by pickup coil and impedance point detected by excitation coil, were evaluated as a function of tempering temperature to characterize the microstructural features, nondestructively. The study revealed that a good correlation exists between the EC parameters and the microstructural changes.

  3. Microstructural characterization of laser surface melted AISI M2 tool steel.

    PubMed

    Arias, J; Cabeza, M; Castro, G; Feijoo, I; Merino, P; Pena, G

    2010-09-01

    We describe the microstructure of Nd:YAG continuous wave laser surface melted high-speed steel, namely AISI M2, treated with different laser scanning speeds and beam diameters on its surface. Microstructural characterization of the remelted surface layer was performed using light optical and scanning electron microscopy and X-ray diffraction. The combination of the three techniques provided new insights into the substantial changes induced by laser surface melting of the steel surface layer. The advantage of the method is that it avoids the difficult and tedious work of preparing samples of this hard material for transmission electron microscopy, which is the technique normally used to study these fine microstructures. A melted zone with a dendritic structure and a partially melted zone with a heterogeneous cellular structure were observed. M(2)C carbides with different morphologies were identified in the resolidified surface layer after laser melting. PMID:20701656

  4. Microstructure evolution and texture development in a friction stir-processed AISI D2 tool steel

    NASA Astrophysics Data System (ADS)

    Yasavol, N.; Abdollah-zadeh, A.; Vieira, M. T.; Jafarian, H. R.

    2014-02-01

    Crystallographic texture developments during friction stir processing (FSP) of AISI D2 tool were studied with respect to grain sizes in different tool rotation rates. Comparison of the grain sizes in various rotation rates confirmed that grain refinement occurred progressively in higher rotation rates by severe plastic deformation. It was found that the predominant mechanism during FSP should be dynamic recovery (DRV) happened concurrently with continuous dynamic recrystallization (CDRX) caused by particle-stimulated nucleation (PSN). The developed shear texture relates to the ideal shear textures of D1 and D2 in bcc metals. The prevalence of highly dense arrangement of close-packed planes of bcc and the lowest Taylor factor showed the lowest compressive residual stress which is responsible for better mechanical properties compared with the grain-precipitate refinement.

  5. Influence of Laser Peening on Phase Transformation and Corrosion Resistance of AISI 321 steel

    NASA Astrophysics Data System (ADS)

    Karthik, D.; Swaroop, S.

    2016-06-01

    The objective of this study is to investigate the influence of laser peening without coating (LPwC) on austenitic to martensitic (γ → α') phase transformation and corrosion behavior of austenitic stainless steel AISI 321 in 3.5% NaCl environment. Results indicate that LPwC induces a large compressive residual stresses of nearly -854 MPa and γ → α' phase transformation of about 18% (volume fraction). Microstructures of peened surface confirmed the γ → α' phase transformation and showed no grain refinement. Hardness increased slightly with a case depth of 900 μm. Despite the smaller surface roughness introduced, corrosion resistance improved after peening due to compressive residual stresses.

  6. Comparisons of modified Vasco X-2 and AISI 9310 gear steels

    NASA Technical Reports Server (NTRS)

    Townsend, D. P.; Zaretsky, E. V.

    1980-01-01

    Endurance tests were conducted with four groups of spur gears manufactured from three heats of consumable electrode vacuum melted (CVM) modified Vasco X-2. Endurance tests were also conducted with gears manufactured from CVM AISI 9310. Bench type rolling element fatigue tests were conducted with both materials. Hardness measurements were made to 811 K. There was no statistically significant life difference between the two materials. Life differences between the different heats of modified Vasco X-2 can be attributed to heat treat variation and resultant hardness. Carburization of gear flanks only can eliminate tooth fracture as a primary failure mode for modified Vasco X-2. However, a tooth surface fatigue spall can act as a nucleus of a tooth fracture failure for the modified Vasco X-2.

  7. Influence of Laser Peening on Phase Transformation and Corrosion Resistance of AISI 321 steel

    NASA Astrophysics Data System (ADS)

    Karthik, D.; Swaroop, S.

    2016-07-01

    The objective of this study is to investigate the influence of laser peening without coating (LPwC) on austenitic to martensitic (γ → α') phase transformation and corrosion behavior of austenitic stainless steel AISI 321 in 3.5% NaCl environment. Results indicate that LPwC induces a large compressive residual stresses of nearly -854 MPa and γ → α' phase transformation of about 18% (volume fraction). Microstructures of peened surface confirmed the γ → α' phase transformation and showed no grain refinement. Hardness increased slightly with a case depth of 900 μm. Despite the smaller surface roughness introduced, corrosion resistance improved after peening due to compressive residual stresses.

  8. Effect of five lubricants on life of AISI 9310 spur gears

    NASA Technical Reports Server (NTRS)

    Townsend, D. P.; Zaretsky, E. V.

    1985-01-01

    Spur-gear surface fatigue tests were conducted with five lubricants using a single lot of consumable-electrode vacuum melted (CVM) AISI 9310 spur gears. The lot of gears was divided into five groups, each of which was tested with a different lubricant. The test lubricants are classified as either a synthetic hydrocarbon, mineral oil, or ester-based lubricant. All five lubricants have imilar viscosity and pressure-viscosity coefficients. A pentaerythritol base stock without sufficient antiwear additives produced a surface fatigue life pproximately 22 percent that of the same base stock with chlorine and phosphorus type additives. The presence of sulfur type antiwear additives in the lubricant did not appear to affect the surface fatigue life of the gears tested. No statistical difference in the 10-percent surface fatigue life was produced with four of the five lubricants.

  9. Wear Resistance of AISI316L Steel Modified by Pre-FPP Treated DLC Coating

    NASA Astrophysics Data System (ADS)

    Nanbu, Hiroshi; Kikuchi, Shoichi; Kameyama, Yutaka; Komotori, Jun

    In order to improve the adhesion strength of the DLC coating, Fine Particle Peening (FPP) treatment was employed as pretreatment for DLC coatings. FPP treatment was performed using SiC shot particles, and then the AISI316L steel was DLC-coated. The FPP treatment increased the surface roughness of the specimen, and a Si-rich layer was formed on the surface because of the mechanical mixing of SiC shot particles into the steel substrate. Reciprocating sliding wear tests were conducted to measure the friction coefficient. While the non-pretreated (only DLC-coated) specimens showed a sudden increase in friction coefficient resulting from delamination of the DLC coating, the pre-FPP-treated specimens maintained a low friction coefficient during the wear tests. This indicates the strong adhesion of the DLC coating of the pre-FPP-treated specimen caused by the increase in surface roughness and the presence of Si on the surface.

  10. Process mapping of laser surface modification of AISI 316L stainless steel for biomedical applications

    NASA Astrophysics Data System (ADS)

    Chikarakara, Evans; Naher, Sumsun; Brabazon, Dermot

    2010-11-01

    A 1.5-kW CO2 laser in pulsed mode at 3 kHz was used to investigate the effects of varied laser process parameters and resulting morphology of AISI 316L stainless steel. Irradiance and residence time were varied between 7.9 to 23.6 MW/cm2 and 50 to 167 μs, respectively. A strong correlation between irradiance, residence time, depth of processing and roughness of processed steel was established. The high depth of altered microstructure and increased roughness were linked to higher levels of both irradiance and residence times. Energy fluence and surface temperature models were used to predict levels of melting occurring on the surface through the analysis of roughness and depth of the region processed. Microstructural images captured by the SEM revealed significant grain structure changes at higher irradiances, but due to increased residence times, limited to the laser in use, the hardness values were not improved.

  11. Effect of Starch Binders in Alumina Coatings on Aisi 316 L Stainless Steel for Medical Application

    NASA Astrophysics Data System (ADS)

    Ghazali, M. J.; Pauzi, A. A.; Azhari, C. H.; Ghani, J. A.; Sulong, A. B.; Mustafa, R.

    A slurry immersion technique of alumina coatings was carried out on several AISI 316 L stainless steels using two types of binding agents; commercial starch and Sarawakian starch (sago), which were also mixed with polyvinylchloride (PVA) for strengthening purposes. The sintering temperatures in this work were varied from 500 to 1000°C. Prior to sintering process, all stainless steels were metallographically ground and polished to approximately 0.6 µm of average roughness. Detailed characterisations on the sintered specimens were carried out with the aid of the secondary electron microscopy (SEM), microhardness and a profilometer. The results revealed that coated steels using sago binder showed improved adhesion and homogenous microstructures with greater hardness of 2642 HV than those found in coated steel with commercial starch after sintering process.

  12. Influence of alumina and titanium dioxide coatings on abrasive wear resistance of AISI 1045 steel

    NASA Astrophysics Data System (ADS)

    Santos, A.; Remolina, A.; Marulanda, J.

    2016-02-01

    This project aims to compare the behaviour of an AISI 1045 steel's abrasive wear resistance when is covered with aluminium oxide (Al2O3) or Titanium dioxide (TiO2), of nanometric size, using the technique of thermal hot spray, which allows to directly project the suspension particles on the used substrate. The tests are performed based on the ASTM G65-04 standard (Standard Test Method for Measuring Abrasion Using the Dry Sand/Rubber Apparatus). The results show that the amount of, lost material increases linearly with the travelled distance; also determined that the thermal treatment of hardening-tempering and the alumina and titanium dioxide coatings decrease in average a 12.9, 39.6 and 29.3% respectively the volume of released material during abrasive wear test.

  13. Microstructural characterization of the HAZ in AISI 444 ferritic stainless steel welds

    SciTech Connect

    Silva, Cleiton C. Farias, Jesualdo P.; Miranda, Helio C.; Guimaraes, Rodrigo F.; Menezes, John W.A.; Neto, Moises A.M.

    2008-05-15

    Ferritic stainless steel is used as a coating for equipment in the petroleum refining industry. Welding is the main manufacturing and maintenance process used. However, little information on the metallurgical alterations caused by welding of these steels is found in the literature, prompting this study. In this study the authors evaluated the HAZ microstructure of AISI 444 ferritic stainless steel welded plates, by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results indicated that a weld thermal cycle caused microphase precipitation in the HAZ of the ferritic stainless steel. Also needle-like Laves phase precipitation occurred in the HAZ, near the partially-melted zone. Other secondary phases such as chi and sigma were observed, as well as nitride, carbide and carbonitride precipitates.

  14. Correlation of substructure with time-dependent fatigue properties of aisi304 stainless steel

    NASA Astrophysics Data System (ADS)

    Ermi, A. M.; Moteff, John

    1982-09-01

    Transmission electron microscopy was employed to study the substructure of AISI 304 stainless steel tested at 482, 593, and 650 °C in low-cycle fatigue with various hold times. Total strains investigated ranged from 0.5 to 2.0 pct, strain rates of 4 E-03 and 4 E-05 s-1. The cell size was found to be inversely related to the relaxed tensile saturation stress, but with different constants of proportionality for the two strain rates. At the lower strain rate, substructures tended to resemble those produced by pure creep. A modified work-hardening theory was used to relate the peak saturation stress to both plastic strain and cell size.

  15. Residual Stresses in LENS-Deposited AISI 410 Stainless Steel Plates

    SciTech Connect

    Wang, L; Felicellli, S D; Pratt, Phillip R

    2008-01-01

    The residual stress in thin plate components deposited by the laser engineered net shaping (LENS{reg_sign}) process was investigated experimentally and numerically. Neutron diffraction mapping was used to characterize the residual stress in LENS-deposited AISI 410 stainless steel thin wall plates. Using the commercial welding software SYSWELD, a thermo-mechanical three-dimensional finite element model was developed, which considers also the effect of metallurgical phase transformations. The model was employed to predict the temperature history and the residual stress field during the LENS process. Several simulations were performed with the geometry and process parameters that were used to build the experimental samples. The origin of the residual stress distribution is discussed based on the thermal histories of the samples, and the modeling results are compared with measurements obtained by neutron diffraction mapping.

  16. 16 CFR Appendix D3 to Part 305 - Water Heaters-Oil

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Water Heaters-Oil D3 Appendix D3 to Part 305... DISCLOSURES REGARDING ENERGY CONSUMPTION AND WATER USE OF CERTAIN HOME APPLIANCES AND OTHER PRODUCTS REQUIRED... Part 305—Water Heaters—Oil Range Information CAPACITY FIRST HOUR RATING Range of Estimated...

  17. 16 CFR Appendix D3 to Part 305 - Water Heaters-Oil

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 16 Commercial Practices 1 2012-01-01 2012-01-01 false Water Heaters-Oil D3 Appendix D3 to Part 305 Commercial Practices FEDERAL TRADE COMMISSION REGULATIONS UNDER SPECIFIC ACTS OF CONGRESS RULE CONCERNING... Part 305—Water Heaters—Oil Range Information CAPACITY FIRST HOUR RATING Range of Estimated...

  18. 26 CFR 31.3406(d)-3 - Special 30-day rules for certain reportable payments.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 15 2014-04-01 2014-04-01 false Special 30-day rules for certain reportable payments. 31.3406(d)-3 Section 31.3406(d)-3 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) EMPLOYMENT TAXES AND COLLECTION OF INCOME TAX AT SOURCE EMPLOYMENT TAXES AND COLLECTION OF INCOME TAX AT SOURCE Collection...

  19. Vitamin D3 regulates cell viability in gastric cancer and cholangiocarcinoma.

    PubMed

    Baek, Sungmin; Lee, Young-Suk; Shim, Hye-Eun; Yoon, Sik; Baek, Sun-Yong; Kim, Bong-Seon; Oh, Sae-Ock

    2011-09-01

    A low serum level of vitamin D has been associated with an increased incidence of gastrointestinal tract cancers. However, the effects of vitamin D3 have not been investigated in gastric cancer and cholangiocarcinoma. In the present study, we found that vitamin D3 treatment significantly suppressed the viability of gastric cancer and cholangiocarcinoma cells. Moreover, vitamin D3 had a synergistic effect with other anti-cancer drugs, such as paclitaxel, adriamycin, and vinblastine, for suppressing cell viability. To determine the underlying mechanism involved in the regulation of viability by vitamin D3, we examined the effects of vitamin D3 on expression of hedgehog signaling target genes, which has been associated with gastric cancer and cholangiocarcinoma. Vitamin D3 treatment decreased the level of mRNA expression of patched1, Gli1, cyclin D1, and Bcl2, suggesting the possibility that vitamin D3 may act through regulation of hedgehog signaling. From the above results, we conclude that vitamin D3 regulates cell viability in gastric cancer and cholangiocarcinoma. PMID:22025972

  20. 16 CFR Appendix D3 to Part 305 - Water Heaters-Oil

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 16 Commercial Practices 1 2011-01-01 2011-01-01 false Water Heaters-Oil D3 Appendix D3 to Part 305... DISCLOSURES REGARDING ENERGY CONSUMPTION AND WATER USE OF CERTAIN HOME APPLIANCES AND OTHER PRODUCTS REQUIRED... Part 305—Water Heaters—Oil Range Information CAPACITY FIRST HOUR RATING Range of Estimated...

  1. Dopamine D3 Receptors Inhibit Hippocampal Gamma Oscillations by Disturbing CA3 Pyramidal Cell Firing Synchrony.

    PubMed

    Lemercier, Clément E; Schulz, Steffen B; Heidmann, Karin E; Kovács, Richard; Gerevich, Zoltan

    2015-01-01

    Cortical gamma oscillations are associated with cognitive processes and are altered in several neuropsychiatric conditions such as schizophrenia and Alzheimer's disease. Since dopamine D3 receptors are possible targets in treatment of these conditions, it is of great importance to understand their role in modulation of gamma oscillations. The effect of D3 receptors on gamma oscillations and the underlying cellular mechanisms were investigated by extracellular local field potential and simultaneous intracellular sharp micro-electrode recordings in the CA3 region of the hippocampus in vitro. D3 receptors decreased the power and broadened the bandwidth of gamma oscillations induced by acetylcholine or kainate. Blockade of the D3 receptors resulted in faster synchronization of the oscillations, suggesting that endogenous dopamine in the hippocampus slows down the dynamics of gamma oscillations by activation of D3 receptors. Investigating the underlying cellular mechanisms for these effects showed that D3 receptor activation decreased the rate of action potentials (APs) during gamma oscillations and reduced the precision of the AP phase coupling to the gamma cycle in CA3 pyramidal cells. The results may offer an explanation how selective activation of D3 receptors may impair cognition and how, in converse, D3 antagonists may exert pro-cognitive and antipsychotic effects. PMID:26779018

  2. On the breakdown of asymptotic Poincare invariance in D = 3 Einstein gravity

    NASA Technical Reports Server (NTRS)

    Deser, S.

    1985-01-01

    It is shown through a series of calculations that neither momentum nor boosts are definable for finite energy solutions of Einstein gravity in D = 3. The contrast between the effects of Lorentz transformations on the corresponding metrics for D = 3 and D = 4 gravity is demonstrated, and some comparisons with the vector gauge treatment of the problem are offered.

  3. Comparison of analysis of vitamin D3 in foods using ultraviolet and mass spectrometric detection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A method for analysis of vitamin D3 in commonly fortified foods and in fish, which contains endogenous vitamin D3, was developed by combining the best aspects of two official methods. The ethyl ether/petroleum ether extraction procedure from AOAC 992.26 was combined with the chromatographic separat...

  4. 17 CFR 240.14d-3 - Filing and transmission of tender offer statement.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... tender offer statement. 240.14d-3 Section 240.14d-3 Commodity and Securities Exchanges SECURITIES AND... tender offer statement. (a) Filing and transmittal. No bidder shall make a tender offer if, after... subject company's securities for which the tender offer is made, unless as soon as practicable on the...

  5. Effect of vitamin D3 on chemokine levels and regulatory T-cells in pulmonary tuberculosis.

    PubMed

    Harishankar, M; Anbalagan, S; Selvaraj, P

    2016-05-01

    1,25-Dihydroxyvitamin D3 [1,25(OH)2D3] the active form of vitamin D3 acts as an immunomodulator in various immune cells. The present study is aimed to study the effect of 1,25(OH)2D3 on chemokine levels and regulatory T-cells in 51 healthy controls (HCs) and 50 pulmonary tuberculosis (PTB) patients. Peripheral blood mononuclear cells were cultured with culture filtrate antigen (CFA) of Mycobacterium tuberculosis in the presence or absence of 1,25(OH)2D3 at 10(-7)M concentration for 72h and the percentage positive regulatory T-cell subsets were studied using flow cytometry. The chemokine levels were estimated in the culture supernatants by ELISA. 1,25(OH)2D3 significantly upregulated the frequency of regulatory T-cell subsets while suppressed the production of chemokine levels in CFA stimulated cultures of HCs and PTB patients (p<0.05). Correlation analysis revealed a significant negative correlation between CD4+Foxp3+ regulatory T-cells and MCP-1, MIP-1β and IP-10 in CFA stimulated with 1,25(OH)2D3 treated cells (p<0.05). The results suggested that 1,25(OH)2D3 upregulated regulatory T-cells and act as anti-inflammatory by downregulating chemokine levels which could be beneficial to protect the host from inflammation and tissue damage during infection. PMID:26927615

  6. Dopamine D3 Receptors Inhibit Hippocampal Gamma Oscillations by Disturbing CA3 Pyramidal Cell Firing Synchrony

    PubMed Central

    Lemercier, Clément E.; Schulz, Steffen B.; Heidmann, Karin E.; Kovács, Richard; Gerevich, Zoltan

    2016-01-01

    Cortical gamma oscillations are associated with cognitive processes and are altered in several neuropsychiatric conditions such as schizophrenia and Alzheimer’s disease. Since dopamine D3 receptors are possible targets in treatment of these conditions, it is of great importance to understand their role in modulation of gamma oscillations. The effect of D3 receptors on gamma oscillations and the underlying cellular mechanisms were investigated by extracellular local field potential and simultaneous intracellular sharp micro-electrode recordings in the CA3 region of the hippocampus in vitro. D3 receptors decreased the power and broadened the bandwidth of gamma oscillations induced by acetylcholine or kainate. Blockade of the D3 receptors resulted in faster synchronization of the oscillations, suggesting that endogenous dopamine in the hippocampus slows down the dynamics of gamma oscillations by activation of D3 receptors. Investigating the underlying cellular mechanisms for these effects showed that D3 receptor activation decreased the rate of action potentials (APs) during gamma oscillations and reduced the precision of the AP phase coupling to the gamma cycle in CA3 pyramidal cells. The results may offer an explanation how selective activation of D3 receptors may impair cognition and how, in converse, D3 antagonists may exert pro-cognitive and antipsychotic effects. PMID:26779018

  7. Implementation of the thermonuclear process in D3He-9Be plasma on the basis of a Z pinch with an ultrafast laser ignition

    NASA Astrophysics Data System (ADS)

    Voronchev, V. T.; Kukulin, V. I.

    2010-01-01

    A new concept of inertial-magnetic confinement fusion is proposed. This concept is based on a high-current Z pinch combined with a femtosecond laser. The fusion target is composed of a D3He fuel contained under a high pressure inside a sealed cylindrical capsule made from metallic 9Be. An electric discharge along the capsule preheats the target and transforms it into a state of compressed liner. A subsequent TW femtosecond-laser pulse focused on a target end face causes ultrafast cold ignition of a small portion of the D3He fuel. This laser impact generates energetic electrons and ions, which trigger a nuclear-physics mechanism of a catalytic heating of the fuel and also creates a detonation shock wave capable of propagating along the plasma filament. It is shown that the self-sustaining fusion burn wave can appear in the D3He-9Be plasma, in which case the bulk of the energy release is carried by nonradioactive ions, with the energy gain being in excess of 50. The possibility of probing the fusion process by means of gamma-ray spectroscopy is also discussed. The radiative-capture reactions 3He( d, γ), D( d, γ), and 3He(3He, γ) naturally accompanying the burning of the D3He fuel are shown to serve as a convenient diagnostic tool. A nuclear “marker” of D3He fusion on the basis of the detection of monochromatic gamma rays produced in the reaction 9Be( α, γn), which is induced in the liner beryllium shell by energetic fusion alpha particles, is also examined.

  8. Functional Regulation of Dopamine D3 Receptor through Interaction with PICK1

    PubMed Central

    Zheng, Mei; Zhang, Xiaohan; Min, Chengchun; Choi, Bo-Gil; Oh, In-Joon; Kim, Kyeong-Man

    2016-01-01

    PICK1, a PDZ domain-containing protein, is known to increase the reuptake activities of dopamine transporters by increasing their expressions on the cell surface. Here, we report a direct and functional interaction between PICK1 and dopamine D3 receptors (D3R), which act as autoreceptors to negatively regulate dopaminergic neurons. PICK1 colocalized with both dopamine D2 receptor (D2R) and D3R in clusters but exerted different functional influences on them. The cell surface expression, agonist affinity, endocytosis, and signaling of D2R were unaffected by the coexpression of PICK1. On the other hand, the surface expression and tolerance of D3R were inhibited by the coexpression of PICK1. These findings show that PICK1 exerts multiple effects on D3R functions. PMID:27169823

  9. D3D augmented reality imaging system: proof of concept in mammography

    PubMed Central

    Douglas, David B; Petricoin, Emanuel F; Liotta, Lance; Wilson, Eugene

    2016-01-01

    Purpose The purpose of this article is to present images from simulated breast microcalcifications and assess the pattern of the microcalcifications with a technical development called “depth 3-dimensional (D3D) augmented reality”. Materials and methods A computer, head display unit, joystick, D3D augmented reality software, and an in-house script of simulated data of breast microcalcifications in a ductal distribution were used. No patient data was used and no statistical analysis was performed. Results The D3D augmented reality system demonstrated stereoscopic depth perception by presenting a unique image to each eye, focal point convergence, head position tracking, 3D cursor, and joystick fly-through. Conclusion The D3D augmented reality imaging system offers image viewing with depth perception and focal point convergence. The D3D augmented reality system should be tested to determine its utility in clinical practice. PMID:27563261

  10. "Cold training" affects rat liver responses to continuous cold exposure.

    PubMed

    Venditti, Paola; Napolitano, Gaetana; Barone, Daniela; Di Meo, Sergio

    2016-04-01

    Continuous exposure of homeothermic animals to low environmental temperatures elicits physiological adaptations necessary for animal survival, which are associated to higher generation of pro-oxidants in thermogenic tissues. It is not known whether intermittent cold exposure (cold training) is able to affect tissue responses to continuous cold exposure. Therefore, we investigated whether rat liver responses to continuous cold exposure of 2 days are modified by cold training (1h daily for 5 days per week for 3 consecutive weeks). Continuous cold increased liver oxidative metabolism by increasing tissue content of mitochondrial proteins and mitochondrial aerobic capacity. Cold training did not affect such parameters, but attenuated or prevented the changes elicited by continuous cold exposure. Two-day cold exposure increased lipid hydroperoxide and protein-bound carbonyl levels in homogenates and mitochondria, whereas cold training decreased such effects although it decreased only homogenate protein damage in control rats. The activities of the antioxidant enzymes GPX and GR and H2O2 production were increased by continuous cold exposure. Despite the increase in GPX and GR activities, livers from cold-exposed rats showed increased susceptibility to in vitro oxidative challenge. Such cold effects were decreased by cold training, which in control rats reduced only H2O2 production and susceptibility to stress. The changes of PGC-1, NRF-1, and NRF-2 expression levels were consistent with those induced by cold exposure and cold training in mitochondrial protein content and antioxidant enzyme activities. However, the mechanisms by which cold training attenuates the effects of the continuous cold exposure remain to be elucidated. PMID:26808664

  11. The cytochrome P450scc system opens an alternate pathway of vitamin D3 metabolism

    PubMed Central

    Slominski, Andrzej; Semak, Igor; Zjawiony, Jordan; Wortsman, Jacobo; Li, Wei; Szczesniewski, Andre; Tuckey, Robert C.

    2008-01-01

    We show that cytochrome P450scc (CYP11A1) in either a reconstituted system or in isolated adrenal mitochondria can metabolize vitamin D3. The major products of the reaction with reconstituted enzyme were 20-hydroxycholecalciferol and 20,22-dihydroxycholecalciferol, with yields of 16 and 4%, respectively, of the original vitamin D3 substrate. Trihydroxycholecalciferol was a minor product, likely arising from further metabolism of dihydroxycholecalciferol. Based on NMR analysis and known properties of P450scc we propose that hydroxylation of vitamin D3 by P450scc occurs sequentially and stereospecifically with initial formation of 20(S)-hydroxyvitamin D3. P450scc did not metabolize 25-hydroxyvitamin D3, indicating that modification of C25 protected it against P450scc action. Adrenal mitochondria also metabolized vitamin D3 yielding 10 hydroxyderivatives, with UV spectra typical of vitamin D triene chromophores. Aminogluthimide inhibition showed that the three major metabolites, but not the others, resulted from P450scc action. It therefore appears that non-P450scc enzymes present in the adrenal cortex to some extent contribute to metabolism of vitamin D3. We conclude that purified P450scc in a reconstituted system or P450scc in adrenal mitochondria can add one hydroxyl group to vitamin D3 with subsequent hydroxylation being observed for reconstituted enzyme but not for adrenal mitochondria. Additional vitamin D3 metabolites arise from the action of other enzymes in adrenal mitochondria. These findings appear to define novel metabolic pathways involving vitamin D3 that remain to be characterized. PMID:16098191

  12. Vitamin D3 alters microglia immune activation by an IL-10 dependent SOCS3 mechanism.

    PubMed

    Boontanrart, Mandy; Hall, Samuel D; Spanier, Justin A; Hayes, Colleen E; Olson, Julie K

    2016-03-15

    Microglia become activated immune cells during infection or disease in the central nervous system (CNS). However, the mechanisms that downregulate activated microglia to prevent immune-mediated damage are not completely understood. Vitamin D3 has been suggested to have immunomodulatory affects, and high levels of vitamin D3 have been correlated with a decreased risk for developing some neurological diseases. Recent studies have demonstrated the synthesis of active vitamin D3, 1,25-dihydroxyvitamin D3, within the CNS, but its cellular source and neuroprotective actions remain unknown. Therefore, we wanted to determine whether microglia can respond to vitamin D3 and whether vitamin D3 alters immune activation of microglia. We have previously shown that microglia become activated by IFNγ or LPS or by infection with virus to express pro-inflammatory cytokines, chemokines, and effector molecules. In this study, activated microglia increased the expression of the vitamin D receptor and Cyp27b1, which encodes the enzyme for converting vitamin D3 into its active form, thereby enhancing their responsiveness to vitamin D3. Most importantly, the activated microglia exposed to vitamin D3 had reduced expression of pro-inflammatory cytokines, IL-6, IL-12, and TNFα, and increased expression of IL-10. The reduction in pro-inflammatory cytokines was dependent on IL-10 induction of suppressor of cytokine signaling-3 (SOCS3). Therefore, vitamin D3 increases the expression of IL-10 creating a feedback loop via SOCS3 that downregulates the pro-inflammatory immune response by activated microglia which would likewise prevent immune mediated damage in the CNS. PMID:26943970

  13. Total body skeletal muscle mass: estimation by creatine (methyl-d3) dilution in humans

    PubMed Central

    Walker, Ann C.; O'Connor-Semmes, Robin L.; Leonard, Michael S.; Miller, Ram R.; Stimpson, Stephen A.; Turner, Scott M.; Ravussin, Eric; Cefalu, William T.; Hellerstein, Marc K.; Evans, William J.

    2014-01-01

    Current methods for clinical estimation of total body skeletal muscle mass have significant limitations. We tested the hypothesis that creatine (methyl-d3) dilution (D3-creatine) measured by enrichment of urine D3-creatinine reveals total body creatine pool size, providing an accurate estimate of total body skeletal muscle mass. Healthy subjects with different muscle masses [n = 35: 20 men (19–30 yr, 70–84 yr), 15 postmenopausal women (51–62 yr, 70–84 yr)] were housed for 5 days. Optimal tracer dose was explored with single oral doses of 30, 60, or 100 mg D3-creatine given on day 1. Serial plasma samples were collected for D3-creatine pharmacokinetics. All urine was collected through day 5. Creatine and creatinine (deuterated and unlabeled) were measured by liquid chromatography mass spectrometry. Total body creatine pool size and muscle mass were calculated from D3-creatinine enrichment in urine. Muscle mass was also measured by magnetic resonance imaging (MRI), dual-energy x-ray absorptiometry (DXA), and traditional 24-h urine creatinine. D3-creatine was rapidly absorbed and cleared with variable urinary excretion. Isotopic steady-state of D3-creatinine enrichment in the urine was achieved by 30.7 ± 11.2 h. Mean steady-state enrichment in urine provided muscle mass estimates that correlated well with MRI estimates for all subjects (r = 0.868, P < 0.0001), with less bias compared with lean body mass assessment by DXA, which overestimated muscle mass compared with MRI. The dilution of an oral D3-creatine dose determined by urine D3-creatinine enrichment provides an estimate of total body muscle mass strongly correlated with estimates from serial MRI with less bias than total lean body mass assessment by DXA. PMID:24764133

  14. The cytochrome P450scc system opens an alternate pathway of vitamin D3 metabolism.

    PubMed

    Slominski, Andrzej; Semak, Igor; Zjawiony, Jordan; Wortsman, Jacobo; Li, Wei; Szczesniewski, Andre; Tuckey, Robert C

    2005-08-01

    We show that cytochrome P450scc (CYP11A1) in either a reconstituted system or in isolated adrenal mitochondria can metabolize vitamin D3. The major products of the reaction with reconstituted enzyme were 20-hydroxycholecalciferol and 20,22-dihydroxycholecalciferol, with yields of 16 and 4%, respectively, of the original vitamin D3 substrate. Trihydroxycholecalciferol was a minor product, likely arising from further metabolism of dihydroxycholecalciferol. Based on NMR analysis and known properties of P450scc we propose that hydroxylation of vitamin D3 by P450scc occurs sequentially and stereospecifically with initial formation of 20(S)-hydroxyvitamin D3. P450scc did not metabolize 25-hydroxyvitamin D3, indicating that modification of C25 protected it against P450scc action. Adrenal mitochondria also metabolized vitamin D3 yielding 10 hydroxyderivatives, with UV spectra typical of vitamin D triene chromophores. Aminogluthimide inhibition showed that the three major metabolites, but not the others, resulted from P450scc action. It therefore appears that non-P450scc enzymes present in the adrenal cortex to some extent contribute to metabolism of vitamin D3. We conclude that purified P450scc in a reconstituted system or P450scc in adrenal mitochondria can add one hydroxyl group to vitamin D3 with subsequent hydroxylation being observed for reconstituted enzyme but not for adrenal mitochondria. Additional vitamin D3 metabolites arise from the action of other enzymes in adrenal mitochondria. These findings appear to define novel metabolic pathways involving vitamin D3 that remain to be characterized. PMID:16098191

  15. Dopamine D3 receptor ligands for drug addiction treatment: update on recent findings.

    PubMed

    Le Foll, Bernard; Collo, Ginetta; Rabiner, Eugenii A; Boileau, Isabelle; Merlo Pich, Emilio; Sokoloff, Pierre

    2014-01-01

    The dopamine D3 receptor is located in the limbic area and apparently mediates selective effects on motivation to take drugs and drug-seeking behaviors, so that there has been considerable interest on the possible use of D3 receptor ligands to treat drug addiction. However, only recently selective tools allowing studying this receptor have been developed. This chapter presents an overview of findings that were presented at a symposium on the conference Dopamine 2013 in Sardinia in May 2013. Novel neurobiological findings indicate that drugs of abuse can lead to significant structural plasticity in rodent brain and that this is dependent on the availability of functional dopamine D3 autoreceptor, whose activation increased phosphorylation in the ERK pathway and in the Akt/mTORC1 pathway indicating the parallel engagement of a series of intracellular signaling pathways all involved in cell growth and survival. Preclinical findings using animal models of drug-seeking behaviors confirm that D3 antagonists have a promising profile to treat drug addiction across drugs of abuse type. Imaging the D3 is now feasible in human subjects. Notably, the development of (+)-4-propyl-9-hydroxynaphthoxazine ligand used in positron emission tomography (PET) studies in humans allows to measure D3 and D2 receptors based on the area of the brain under study. This PET ligand has been used to confirm up-regulation of D3 sites in psychostimulant users and to reveal that tobacco smoking produces elevation of dopamine at the level of D3 sites. There are now novel antagonists being developed, but also old drugs such as buspirone, that are available to test the D3 hypothesis in humans. The first results of clinical investigations are now being provided. Overall, those recent findings support further exploration of D3 ligands to treat drug addiction. PMID:24968784

  16. Massive cold cloud clusters

    NASA Astrophysics Data System (ADS)

    Toth, L. Viktor; Marton, Gabor; Zahorecz, Sarolta

    2015-08-01

    The all-sky Planck catalogue of Galactic Cold Clumps (PGCC, Planck 2015 results XXVIII 2015) allows an almost unbiased study of the early phases of star-formation in our Galaxy. Several thousand of the clumps have also distance estimates allowing a mass, and density determination. The nature of Planck clumps varies from IRDCs to tiny nearby cold clouds with masses ranging from one to several tens of thousands solar masses. Some of the clumps are embedded in GMCs, others are isolated. Some are close or even very close to OB associations, while others lay far from any UV luminous objects.The small scale clustering of these objects was studied with the improved Minimum Spanning Tree method of Cartwright & Whitworth identifying groups in 3D space. As a result also massive cold cloud clusters were identified. We analyse the MST structures, and discuss their relation to ongoing and future massive star formation.

  17. Kinetic studies of 25-hydroxy-19-nor-vitamin D3 and 1 alpha,25-dihydroxy-19-nor-vitamin D3 hydroxylation by CYP27B1 and CYP24A1.

    PubMed

    Urushino, Naoko; Nakabayashi, Sachie; Arai, Midori A; Kittaka, Atsushi; Chen, Tai C; Yamamoto, Keiko; Hayashi, Keiko; Kato, Shigeaki; Ohta, Miho; Kamakura, Masaki; Ikushiro, Shinichi; Sakaki, Toshiyuki

    2007-09-01

    Our previous study demonstrated that 25-hydroxy-19-nor-vitamin D(3) [25(OH)-19-nor-D(3)] inhibited the proliferation of immortalized noncancerous PZ-HPV-7 prostate cells similar to 1 alpha,25-dihydroxyvitamin D(3) [1 alpha,25(OH)(2)D(3)], suggesting that 25(OH)-19-nor-D(3) might be converted to 1 alpha,25-dihydroxy-19-nor-vitamin D(3) [1 alpha,25(OH)(2)-19-nor-D(3)] by CYP27B1 before exerting its antiproliferative activity. Using an in vitro cell-free model to study the kinetics of CYP27B1-dependent 1 alpha-hydroxylation of 25(OH)-19-nor-D(3) and 25-hydroxyvitamin D(3) [25(OH)D(3)] and CYP24A1-dependent hydroxylation of 1 alpha,25(OH)-19-nor-D(3) and 1 alpha,25(OH)(2)D(3), we found that k(cat)/K(m) for 1 alpha-hydroxylation of 25(OH)-19-nor-D(3) was less than 0.1% of that for 25(OH)D(3), and the k(cat)/K(m) value for 24-hydroxylation was not significantly different between 1 alpha,25(OH)(2)-19-nor-D(3) and 1 alpha,25(OH)(2)D(3). The data suggest a much slower formation and a similar rate of degradation of 1 alpha,25(OH)(2)-19-nor-D(3) compared with 1 alpha,25(OH)(2)D(3). We then analyzed the metabolites of 25(OH)D(3) and 25(OH)-19-nor-D(3) in PZ-HPV-7 cells by high-performance liquid chromatography. We found that a peak that comigrated with 1 alpha,25(OH)(2)D(3) was detected in cells incubated with 25(OH)D(3), whereas no 1 alpha,25(OH)(2)-19-nor-D(3) was detected in cells incubated with 25(OH)-19-nor-D(3). Thus, the present results do not support our previous hypothesis that 25(OH)-19-nor-D(3) is converted to 1 alpha,25(OH)(2)-19-nor-D(3) by CYP27B1 in prostate cells to inhibit cell proliferation. We hypothesize that 25(OH)-19-nor-D(3) by itself may have a novel mechanism to activate vitamin D receptor or it is metabolized in prostate cells to an unknown metabolite with antiproliferative activity without 1 alpha-hydroxylation. Thus, the results suggest that 25(OH)-19-nor-D(3) has potential as an attractive agent for prostate cancer therapy. PMID:17553915

  18. Cold-responsive gene regulation during cold acclimation in plants.

    PubMed

    Lissarre, Mickael; Ohta, Masaru; Sato, Aiko; Miura, Kenji

    2010-08-01

    Regulation of the transcriptome is necessary for plants to acquire cold tolerance, and cold induces several genes via a cold signaling pathway. The transcription factors CBF/DREB1 (C-repeat binding factor/dehydration responsive element binding1) and ICE1 (inducer of CBF expression1) have important roles in the regulation of cold-responsive gene expression. ICE1 is post-translationally regulated by ubiquitylation-mediated proteolysis and sumoylation. This mini-review highlights some recent studies on plant cold signaling. The relationships among cold signaling, salicylic acid accumulation and stomatal development are also discussed. PMID:20699657

  19. Cold holographic matter in the Higgs branch

    NASA Astrophysics Data System (ADS)

    Itsios, Georgios; Jokela, Niko; Ramallo, Alfonso V.

    2015-07-01

    We study collective excitations of cold (2 + 1)-dimensional fundamental matter living on a defect of the four-dimensional N = 4 super Yang-Mills theory in the Higgs branch. This system is realized holographically as a D3-D5 brane intersection, in which the D5-brane is treated as a probe with a non-zero gauge flux across the internal part of its worldvolume. We study the holographic zero sound mode in the collisionless regime at low temperature and find a simple analytic result for its dispersion relation. We also find the diffusion constant of the system in the hydrodynamic regime at higher temperature. In both cases we study the dependence on the flux parameter which determines the amount of Higgs symmetry breaking. We also discuss the anyonization of this construction.

  20. Optimization of cold and warm workability in 304 stainless steel using instability maps

    SciTech Connect

    Venugopal, S.; Mannan, S.L.; Prasad, Y.V.R.K.

    1996-01-01

    The deformation characteristics of stainless steel type AISI 304 under compression in the temperature range 20 C to 600 C and strain-rate range 0.001 to 100 s{sup {minus}1} have been studied with a view to characterizing the flow instabilities occurring in the microstructure. At strain rates less than 5 s{sup {minus}1}, 304 stainless steel exhibits flow localization, whereas dynamic strain aging occurs at intermediate temperatures and below 0.5 s{sup {minus}1}. At room temperatures and strain rates less than 10 s{sup {minus}1}, martensite formation is observed. To avoid the preceding microstructural instabilities, cold and warm working should be carried out at strain rates greater than 5 s{sup {minus}1}. The continuum criterion, developed on the basis of the principles of maximum rate of entropy production and separability of the dissipation function, predicts accurately all the preceding instability features.

  1. VizieR Online Data Catalog: H2 d3{Pi}u excitation by elec

    NASA Astrophysics Data System (ADS)

    Liu, X.; Shemansky, D. E.; Yoshii, J.; Johnson, P. V.; Malone, C. P.; Ajello, J. M.

    2016-05-01

    Electron-impact excitation of H2 triplet states plays an imp role in the heating of outer planet upper thermospheres. The d3{Pi}u state is the third ungerade triplet state, and the d3{Pi}u-a3{Sigma}g+ emission is the largest cascade channel for the a3{Sigma}g+ state. Accurate energies of the d3{Pi}u-(v, J) levels are calculated from an ab initio potential energy curve. Radiative lifetimes of the d3{Pi}u(v,J) levels are obtained by an accurate evaluation of the d3{Pi}u-a3{Sigma}g+ transition probabilities. The emission yields are determined from experimental lifetimes and calculated radiative lifetimes and are further verified by comparing experimental and synthetic d3{Pi}u-a3{Sigma}g+ spectra at 20eV impact energy. Spectral analysis revealed that multipolar components beyond the dipolar term are required to model the X1{Sigma}g+-d3{Pi}u excitation, and significant cascade excitation occurs at the d3{Pi}u (v=0,1) levels. Kinetic energy (Ek) distributions of H atoms produced via predissociation of the 3{Pi}u state and the d3{Pi}u-a3{Sigma}g+-b3{Sigma}u+ cascade dissociative emission are obtained. Predissociation of the d3{Pi}u state produces H atoms with an average Ek of 2.3+/-0.4 eV/atom, while the Ekdistribution of the d3{Pi}u-a3{Sigma}g+-b3{Sigma}u+ channel is similar to that of the X1{Sigma}g+-a3{Sigma}g+-b3{Sigma}u+ channel and produces H(1s) atoms with an average Ek of 1.15+/-0.05eV/atom. On average, each H2 excited to the d3{Pi}u state in an H2-dominated atmosphere deposits 3.3+/-0.4eV into the atmosphere, while each H2directly excited to the a3{Sigma}g+ state gives 2.2-2.3eV to the atmosphere. The spectral distribution of the calculated a3{Sigma}g+-b3{Sigma}u+ continuum emission due to the X1{Sigma}g+-d3{Pi}u excitation is significantly different from that of direct a3{Sigma}g+ excitation. (2 data files).

  2. Fortification of cheese with vitamin D3 using dairy protein emulsions as delivery systems.

    PubMed

    Tippetts, M; Martini, S; Brothersen, C; McMahon, D J

    2012-09-01

    Vitamin D is an essential vitamin that is synthesized when the body is exposed to sunlight or after the consumption of fortified foods and supplements. The purpose of this research was to increase the retention of vitamin D(3) in Cheddar cheese by incorporating it as part of an oil-in-water emulsion using a milk protein emulsifier to obtain a fortification level of 280 IU/serving. Four oil-in-water vitamin D emulsions were made using sodium caseinate, calcium caseinate, nonfat dry milk (NDM), or whey protein. These emulsions were used to fortify milk, and the retention of vitamin D(3) in cheese curd in a model cheesemaking system was calculated. A nonemulsified vitamin D(3) oil was used as a control to fortify milk. Significantly more vitamin D(3) was retained in the curd when using the emulsified vitamin D(3) than the nonemulsified vitamin D(3) oil (control). No significant differences were observed in the retention of vitamin D(3) when emulsions were formulated with different emulsifiers. Mean vitamin D(3) retention in the model system cheese curd was 96% when the emulsions were added to either whole or skim milk compared with using the nonemulsified oil, which gave mean retentions of only 71% and 64% when added to whole and skim milk, respectively. A similar improvement in retention was achieved when cheese was made from whole and reduced-fat milk using standard manufacturing procedures on a small scale. When sufficient vitamin D(3) was added to produce cheese containing a target level of approximately 280 IU per 28-g serving, retention was greater when the vitamin D(3) was emulsified with NDM than when using nonemulsified vitamin D(3) oil. Only 58±3% of the nonemulsified vitamin D(3) oil was retained in full-fat Cheddar cheese, whereas 78±8% and 74±1% were retained when using the vitamin D(3) emulsion in full-fat and reduced-fat Cheddar cheese, respectively. PMID:22916880

  3. Effect of 1,25-dihydroxyvitamin D3 on phospholipid metabolism in cultured bovine parathyroid cells.

    PubMed

    Sugimoto, T; Ritter, C; Slatopolsky, E; Morrissey, J

    1988-06-01

    There is evidence that 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] affects phospholipid metabolism of intestine, kidney, and bone. There are no such studies concerning the parathyroid gland, which is also a target tissue for 1,25-(OH)2D3. In this investigation we examined the effect of 1,25-(OH)2D3 on the incorporation of radiolabeled choline, inositol, serine, and ethanolamine into the phospholipids of cultured bovine parathyroid cells. Treatment with 10(-8) M 1,25-(OH)2D3 for 48 h caused a significant decrease in [14C]choline incorporation, although there were no differences in the incorporation of radiolabeled inositol, serine, or ethanolamine. Time-course and dose-response evaluations of the 1,25-(OH)2D3 effect revealed that the decrease in [14C]choline incorporation was seen within 12 h of incubation and occurred with as little as 10(-9) M, respectively. In contrast, neither 10(-7) M 25-hydroxyvitamin D3 nor 10(-7) M 24,25-(OH)2D3 caused significant changes in [14C]choline incorporation. When 5 X 10(-6) M cycloheximide was added to the medium, the inhibitory effect of 1,25-(OH)2D3 on [14C]choline incorporation was completely abolished. A significant decrease in phosphatidylcholine content was observed after treatment with 10(-8) M 1,25-(OH)2D3 for 96 h. 1,25-(OH)2D3 did not cause a dramatic change in the fatty acid composition of the phosphatidylcholine. The present studies demonstrate that in parathyroid cells 1,25-(OH)2D3 causes a decrease in [14C]choline incorporation, which could be due to a decrease in the synthesis of phosphatidylcholine or increased degradation. This effect is specific for 1,25-(OH)2D3 and requires new protein synthesis. PMID:3131114

  4. 79 FR 46993 - Food Additives Permitted for Direct Addition to Food for Human Consumption; Vitamin D3

    Federal Register 2010, 2011, 2012, 2013, 2014

    2014-08-12

    ... to Food for Human Consumption; Vitamin D 3 AGENCY: Food and Drug Administration, HHS. ACTION: Final... to provide for the safe use of vitamin D 3 as a nutrient supplement in meal replacement beverages.... 172.380 (21 CFR 172.380), Vitamin D 3 , to provide for the safe use of vitamin D 3 as a...

  5. Dose response to vaginal administration of 1,25-dihydroxyvitamin D3 to cows.

    PubMed

    Okura, N; Yamagishi, N; Naito, Y; Koiwa, M

    2007-07-01

    It was previously reported that intravaginal (IVAG) administration of 1,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3)) might be protective against bovine hypocalcaemia. In the present study, various doses of exogenous 1,25(OH)(2)D(3) were administered IVAG to ovariectomised cows, and the subsequent changes in the biochemical parameters of the blood were measured to assess the characteristics of vaginal absorption. Five cows received 1,25(OH)(2)D(3) IVAG at a dose of 0.125, 0.25, 0.5, or 1.0microg/kg of body weight (BW) or intravenously at a dose of 1.0microg/kg BW. Dosing was at intervals of at least two weeks in a 5x5 Latin square design. Vaginally administered 1,25(OH)(2)D(3) was absorbed in a dose-dependent manner. There was no correlation between the IVAG dose of 1,25(OH)(2)D(3) and subsequent changes in plasma calcium concentrations. The bioavailability of 1,25(OH)(2)D(3) administered IVAG at 1.0microg/kg BW was approximately 93%. PMID:16759888

  6. 1,25-Dihydroxyvitamin D3 and retinoid X receptor expression in human colorectal neoplasms.

    PubMed Central

    Kane, K F; Langman, M J; Williams, G R

    1995-01-01

    Epidemiological studies suggest that 1,25-dihydroxyvitamin D3 (D3) protects against colorectal carcinogenesis. Animal and in vitro studies show an antiproliferative effect of D3 in a variety of tumours including those of large bowel origin. D3 actions are mediated by D3 receptors (VDR) alone or by VDR in conjunction with retinoid X receptors (RXRs) in all D3 responsive tissues. The expression of mRNAs encoding VDR and RXRs in normal and malignant human colorectum was determined. Full length VDR (4.6 kB), RXR alpha (5.5 kB), and RXR gamma (3.5 and 7 kB) mRNAs were expressed in all tissues, but RXR beta mRNA was not expressed in any. VDR expression was reduced in 12 carcinomas relative to paired normal mucosa, and RXR alpha expression was reduced in nine. There was no correlation between VDR or RXR alpha expression and the site, grade of differentiation, or Dukes's staging of the tumour. The finding of persistent VDR and RXR coexpression in all colorectal tumours provides a rational basis for exploring a role for D3 in the treatment of colorectal malignancy. Images Figure 1 Figure 2 PMID:7883226

  7. Homology modeling of dopamine D2 and D3 receptors: molecular dynamics refinement and docking evaluation.

    PubMed

    Platania, Chiara Bianca Maria; Salomone, Salvatore; Leggio, Gian Marco; Drago, Filippo; Bucolo, Claudio

    2012-01-01

    Dopamine (DA) receptors, a class of G-protein coupled receptors (GPCRs), have been targeted for drug development for the treatment of neurological, psychiatric and ocular disorders. The lack of structural information about GPCRs and their ligand complexes has prompted the development of homology models of these proteins aimed at structure-based drug design. Crystal structure of human dopamine D(3) (hD(3)) receptor has been recently solved. Based on the hD(3) receptor crystal structure we generated dopamine D(2) and D(3) receptor models and refined them with molecular dynamics (MD) protocol. Refined structures, obtained from the MD simulations in membrane environment, were subsequently used in molecular docking studies in order to investigate potential sites of interaction. The structure of hD(3) and hD(2L) receptors was differentiated by means of MD simulations and D(3) selective ligands were discriminated, in terms of binding energy, by docking calculation. Robust correlation of computed and experimental K(i) was obtained for hD(3) and hD(2L) receptor ligands. In conclusion, the present computational approach seems suitable to build and refine structure models of homologous dopamine receptors that may be of value for structure-based drug discovery of selective dopaminergic ligands. PMID:22970199

  8. Homology Modeling of Dopamine D2 and D3 Receptors: Molecular Dynamics Refinement and Docking Evaluation

    PubMed Central

    Platania, Chiara Bianca Maria; Salomone, Salvatore; Leggio, Gian Marco; Drago, Filippo; Bucolo, Claudio

    2012-01-01

    Dopamine (DA) receptors, a class of G-protein coupled receptors (GPCRs), have been targeted for drug development for the treatment of neurological, psychiatric and ocular disorders. The lack of structural information about GPCRs and their ligand complexes has prompted the development of homology models of these proteins aimed at structure-based drug design. Crystal structure of human dopamine D3 (hD3) receptor has been recently solved. Based on the hD3 receptor crystal structure we generated dopamine D2 and D3 receptor models and refined them with molecular dynamics (MD) protocol. Refined structures, obtained from the MD simulations in membrane environment, were subsequently used in molecular docking studies in order to investigate potential sites of interaction. The structure of hD3 and hD2L receptors was differentiated by means of MD simulations and D3 selective ligands were discriminated, in terms of binding energy, by docking calculation. Robust correlation of computed and experimental Ki was obtained for hD3 and hD2L receptor ligands. In conclusion, the present computational approach seems suitable to build and refine structure models of homologous dopamine receptors that may be of value for structure-based drug discovery of selective dopaminergic ligands. PMID:22970199

  9. Neuronal circuitry underlying the impact of D3 receptor ligands in drug addiction.

    PubMed

    Le Foll, Bernard; Di Ciano, Patricia

    2015-09-01

    Since the cloning of the D3 receptor in the early 1990s, there has been a great deal of interest in this receptor as a possible therapeutic target for drug addiction. The development of a D3 ligand suitable for use in humans has remained elusive, so the study of the function of the D3 receptor and its possible therapeutic efficacy has largely been restricted to animals. Pre-clinical studies have established that systemic administration of D3 ligands, particularly antagonists and partial agonists, can alter drug-seeking in animals. Despite over a decade of research, few studies have investigated the effects of intra-cerebral infusion of D3 ligands on drug-seeking. In the present review, these studies are summarized, which have largely focused on stimulus-controlled behaviors. Converging evidence from studies of D3 receptor expression, Fos and pharmacological Magnetic Resonance Imaging (phMRI) is also provided to delineate some of the D3 brain systems involved in drug-seeking and taking. The data so far indicate that different brain systems may be involved in different types of stimulus control as well as drug taking. PMID:25266821

  10. Identifying Medication Targets for Psychostimulant Addiction: Unraveling the Dopamine D3 Receptor Hypothesis

    PubMed Central

    2016-01-01

    The dopamine D3 receptor (D3R) is a target for developing medications to treat substance use disorders. D3R-selective compounds with high affinity and varying efficacies have been discovered, providing critical research tools for cell-based studies that have been translated to in vivo models of drug abuse. D3R antagonists and partial agonists have shown especially promising results in rodent models of relapse-like behavior, including stress-, drug-, and cue-induced reinstatement of drug seeking. However, to date, translation to human studies has been limited. Herein, we present an overview and illustrate some of the pitfalls and challenges of developing novel D3R-selective compounds toward clinical utility, especially for treatment of cocaine abuse. Future research and development of D3R-selective antagonists and partial agonists for substance abuse remains critically important but will also require further evaluation and development of translational animal models to determine the best time in the addiction cycle to target D3Rs for optimal therapeutic efficacy. PMID:25826710

  11. Pramipexole inhibits MPTP toxicity in mice by dopamine D3 receptor dependent and independent mechanisms.

    PubMed

    Ramirez, Andres D; Wong, Stephen K-F; Menniti, Frank S

    2003-08-15

    The role of dopamine D3 receptors was investigated in mediating the neuroprotective effect of the dopamine D2/D3 receptor agonist (S)-2-amino-4,5,6,7-tetrahydro-6-propylamine-benzothiazole (pramipexole) in vivo. Pramipexole retained the ability to inhibit 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced dopamine depletion in mice in which the dopamine D3 receptor had been deleted. However, the neuroprotective efficacy was reduced in the dopamine D3 receptor-deleted mice compared to that in littermates expressing the wildtype receptor. Furthermore, the dopamine D3 receptor selective antagonist 2-(3-[4-(2-tert-butyl-6-trifluoromethyl-4-pyrimidinyl)-1-piperazinyl]propylthio)-4-pyrimidinol (A-437203) partially inhibited the neuroprotective effect of pramipexole in dopamine D3 receptor expressing mice but not in receptor-deleted mice. These results indicate that pramipexole protects dopamine neurons from MPTP-induced toxicity by mechanisms that are both dependent and independent of an interaction with dopamine D3 receptors. PMID:12954356

  12. Regulation of calcium signaling in dendritic cells by 1,25-dihydroxyvitamin D3.

    PubMed

    Shumilina, Ekaterina; Xuan, Nguyen Thi; Matzner, Nicole; Bhandaru, Madhuri; Zemtsova, Irina M; Lang, Florian

    2010-06-01

    Dendritic cells (DCs) are antigen-presenting cells that provide a link between innate and adaptive immunity. Ca(2+)-dependent signaling plays a central regulatory role in DC responses to diverse antigens. DCs are a primary target of 1,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)], a secosteroid hormone, that, in addition to its well-established action on Ca(2+) homeostasis, possesses immunomodulatory properties. Surprisingly, nothing is known about its effects on DC cytosolic Ca(2+) activity. The present study explored whether 1,25(OH)(2)D(3) modifies the intracellular Ca(2+) concentration ([Ca(2+)](i)) in DCs. Here we show that mouse DCs expressed K(+)-independent (NCX1-3) and K(+)-dependent (NCKX1, 3, 4, and 5) Na(+)/Ca(2+) exchangers. Acute application of LPS (100 ng/ml) to DCs increased [Ca(2+)](i), an effect significantly blunted by prior incubation with 1,25(OH)(2)D(3). 1,25(OH)(2)D(3) increased the membrane abundance of the NCKX1 protein, up-regulated the K(+)- and Na(+)-dependent Ca(2+) entry and enhanced the K(+)-dependent Na(+)/Ca(2+) exchanger currents. The NCKX blocker 3',4'-dichlorobenzamyl (DBZ) reversed the inhibitory effect of 1,25(OH)(2)D(3) on the LPS-induced increase of [Ca(2+)](i). Expression of the costimulatory molecule CD86 was down-regulated by 1,25(OH)(2)D(3), an effect reversed by DBZ. In summary, 1,25(OH)(2)D(3) blunts the LPS-induced increase in [Ca(2+)](i) by stimulation of Na(+)/Ca(2+) exchanger-dependent Ca(2+) extrusion, an effect that contributes to 1,25(OH)(2)D(3)-mediated immunosuppression. The results disclose completely novel mechanisms in the regulation of DC maturation and function. PMID:20124438

  13. Vitamin D3 potentiates the antitumorigenic effects of arsenic trioxide in human leukemia (HL-60) cells

    PubMed Central

    2014-01-01

    Background Arsenic trioxide (ATO) is a novel form of therapy that has been found to aid acute promyelocytic leukemia (APL) patients. Our laboratory has demonstrated that ATO-induced cytotoxicity in human leukemia (HL-60) cells is mediated by oxidative stress. Pro-oxidants have been known to play a role in free radical-mediated oxidative stress. Vitamin D3, (Vit D3) an active metabolite of vitamin D has been reported to inhibit the growth of number neoplasms such as prostate, breast, colorectal, leukemia, and skin cancers. The goal of the present research was to use (HL-60) cells as an in vitro test model to evaluate whether low doses of Vit D3 potentiate the toxicity of ATO and whether this toxic action is mediated via apoptotic mechanisms. Method HL-60 cells were treated either with a pharmacologic dose of ATO alone and with several low doses of Vit D3. Cell survival was determined by MTT assay. Cell apoptosis was measured both by flow cytometry assessment, and DNA laddering assay. Results MTT assay indicated that Vit D3 co-treatment potentiates ATO toxicity in HL-60 cells in a dose dependent manner. A statistically significant and dose-dependent increase (p <0.05) was recorded in annexin V positive cells (apoptotic cells) with increasing doses of Vit D3 in ATO-treated cells. This finding was confirmed by the result of DNA laddering assay showing clear evidence of nucleosomal DNA fragmentation in vitamin and ATO co-treated cells. Conclusion The present study indicates that Vit D3 potentiates the antitumor effects of ATO. This potentiation is mediated at least in part, through induction of phosphatidylserine externalization and nucleosomal DNA fragmentation. These findings highlight the potential impact of Vit D3 in promoting the pharmacological effect of ATO, suggesting a possible future role of Vit D3/ATO combination therapy in patients with acute promyelocytic leukemia (APL). PMID:24661615

  14. Benzothiadiazole (BTH) activates sterol pathway and affects vitamin D3 metabolism in Solanum malacoxylon cell cultures.

    PubMed

    Burlini, Nedda; Iriti, Marcello; Daghetti, Anna; Faoro, Franco; Ruggiero, Antonietta; Bernasconi, Silvana

    2011-11-01

    Benzo-(1,2,3)-thiadiazole-7-carbothioic acid S-methyl ester (BTH), a particularly efficient inducer of systemic acquired resistance (SAR), was developed as an immunizing agent to sensitize various crop species against pathogen infections. Recent works highlighted its activating effect on different metabolic pathways, concerning both primary and secondary metabolites. In this study, we investigated the effect of BTH treatment on sterol levels and vitamin D(3) metabolism in Solanum malacoxylon cultures. Calli of S. malacoxylon were incubated in Gamborg B5 liquid medium alone or added with 50 μM BTH for different times (one, two or three cycles of light). Histocytochemical investigations performed on our experimental system using 3,3'-diaminobenzidine (DAB) for hydrogen peroxide (H(2)O(2)) detection and phloroglucinol for lignin staining showed that BTH causes H(2)O(2) accumulation and lignin deposition in treated calli. Gas chromatographic analysis of principal cell membrane sterols (β-sitosterol, campesterol, stigmasterol) showed that BTH transiently increases their cellular levels. Callus cultures were found to contain also cholesterol, 7-dehydrocholesterol, the putative precursor of vitamin D(3), and the hydroxylated metabolites 25-hydroxyvitamin D(3) [25(OH)D(3)] and 1α,25-dihydroxyvitamin D(3) [1α,25(OH)(2)D(3)]. BTH treatment enhanced 7-dehydrocholesterol while reduced cholesterol. HPLC analysis of sample extracts showed that BTH does not affect the cell content of vitamin D(3), though results of ELISA tests highlighted that this elicitor moderately enhances the levels of 25(OH)D(3) and 1α,25(OH)(2)D(3) metabolites. In conclusion, BTH treatment not only causes cell wall strengthening, a typical plant defence response, as just described in other experimental models, but in the same time increases the cellular level of the main sterols and 7-dehydrocholesterol. PMID:21779826

  15. 1,25-Dihydroxyvitamin-D3 Induces Avian β-Defensin Gene Expression in Chickens

    PubMed Central

    Zhang, Guolong; Ouyang, Linghua; Robinson, Kelsy; Tang, Yanqiang; Zhu, Qing; Li, Diyan; Hu, Yaodong; Liu, Yiping

    2016-01-01

    Host defense peptides (HDPs) play a critical role in innate immunity. Specific modulation of endogenous HDP synthesis by dietary compounds has been regarded as a novel approach to boost immunity and disease resistance in animal production. 1,25-dihydroxy vitamin D3 (1,25D3) is well known as a powerful HDP inducer in humans, but limited information about the effect of 1,25D3 on HDPs in poultry is available. Here, we sought to examine whether 1,25D3 could stimulate avian β-defensin (AvBD) expression in chickens. We used chicken embryo intestinal epithelial cells (CEIEPCs) and peripheral blood mononuclear cells (PBMCs) to study the effect of 1,25D3 on the expression of AvBDs. We observed that 1,25D3 is able to up-regulate the expression of several AvBDs in CEIEPCs and PBMCs, whereas it increased the amounts of AvBD4 mRNA in CEIEPCs only in the presence of lipopolysaccharide (LPS). On the other hand, LPS treatment not only inhibited the expression of CYP24A1 but also altered the expression pattern of VDR in CEIEPCs. Furthermore, AvBDs were not directly regulated by 1,25D3, as cycloheximide completely blocked 1,25D3-induced expression of AvBDs. Our observations suggest that 1,25D3 is capable of inducing AvBD gene expression and is a potential antibiotic alternative through augmentation of host innate immunity as well as disease control in chickens. PMID:27135828

  16. Corrosion behavior of plasma sprayed hydroxyapatite and hydroxyapatite-silicon oxide coatings on AISI 304 for biomedical application

    NASA Astrophysics Data System (ADS)

    Singh, Gurpreet; Singh, Hazoor; Sidhu, Buta Singh

    2013-11-01

    The objective of this study is to evaluate corrosion resistance of plasma sprayed hydroxyapatite (HA) and HAsbnd silicon oxide (SiO2) coated AISI 304 substrates. In HAsbnd SiO2 coatings, 10 wt% SiO2 and 20 wt% SiO2 was mixed with HA. The feedstock and coatings were characterized by X-ray diffraction and scanning electron microscopy/energy dispersive X-ray spectroscopy. The corrosion resistance was determined for the uncoated and coated samples. The corrosion resistance of the AISI 304 was found more after the deposition of the HAsbnd SiO2 coatings rather than HA coating and uncoated. All the coatings were crack free after 24 h dipping in Ringer's solution for electrochemical corrosion testing.

  17. Influence of grain refinement on the electrochemical behavior of AISI 430 ferritic stainless steel in an alkaline solution

    NASA Astrophysics Data System (ADS)

    Fattah-alhosseini, A.; Vafaeian, S.

    2016-01-01

    In this paper, the effect of grain refinement on the electrochemical behavior of AISI 430 ferritic stainless steel in 0.1 M NaOH solution was investigated. Potentiodynamic polarization curves showed that fine-grained samples have less corrosion potential, higher corrosion current density, and less protective passive film in comparison to coarse-grained samples. Electrochemical impedance spectroscopy (EIS) analysis revealed that implementing the thermomechanical operation led to lower polarization resistance. Also, Mott-Schottky analysis revealed that the passive films on both fine-grained and coarse-grained samples behave as n-type and p-type semiconductors and the semiconductor character of the passive films did not change by grain refinement. Moreover, it was found that the calculated donor and acceptor densities increased with grain refinement. Thus, the presented results indicated that grain refinement weakens the corrosion and passivation behavior of AISI 430 stainless steel in this alkaline solution.

  18. Heating up cold agglutinins.

    PubMed

    Stone, Marvin J

    2010-10-28

    In this issue of Blood, Berentsen and coworkers describe a high response rate which is durable in some patients who receive combination fludarabine and rituximab for chronic cold agglutinin disease (CAD). If confirmed, this is a significant advance in therapy for a frequently difficult clinical problem. PMID:21030565

  19. Cold agglutinin disease.

    PubMed

    Swiecicki, Paul L; Hegerova, Livia T; Gertz, Morie A

    2013-08-15

    Cold agglutinin disease is a rare and poorly understood disorder affecting 15% of patients with autoimmune hemolytic anemia. We reviewed the clinical and pathologic features, prognosis, and management in the literature and describe our institutional experience to improve strategies for accurate diagnosis and treatment. Retrospective analysis identified 89 patients from our institution with cold agglutinin disease from 1970 through 2012. Median age at symptom onset was 65 years (range, 41 to 83 years), whereas the median age at diagnosis was 72 years (range, 43 to 91 years). Median survival of all patients was 10.6 years, and 68 patients (76%) were alive 5 years after the diagnosis. The most common symptom was acrocyanosis (n = 39 [44%]), and many had symptoms triggered by cold (n = 35 [39%]) or other factors (n = 20 [22%]). An underlying hematologic disorder was detected in 69 patients (78%). Thirty-six patients (40%) received transfusions during their disease course, and 82% received drug therapy. Rituximab was associated with the longest response duration (median, 24 months) and the lowest proportion of patients needing further treatment (55%). Our institution's experience and review of the literature confirms that early diagnostic evaluation and treatment improves outcomes in cold agglutinin disease. PMID:23757733

  20. Out in the cold.

    PubMed

    Bates, Jane

    2016-05-01

    Every now and then, you say something to a patient and wonder whether you should have kept quiet. On this occasion, a female patient and I were indulging in a moment of shared empathy over an annoying symptom we both experience - permanently cold feet. PMID:27154099

  1. Cold spray nozzle design

    DOEpatents

    Haynes, Jeffrey D.; Sanders, Stuart A.

    2009-06-09

    A nozzle for use in a cold spray technique is described. The nozzle has a passageway for spraying a powder material, the passageway having a converging section and a diverging section, and at least the diverging section being formed from polybenzimidazole. In one embodiment of the nozzle, the converging section is also formed from polybenzimidazole.

  2. Cold Facts about Viruses.

    ERIC Educational Resources Information Center

    Pea, Celeste; Sterling, Donna R.

    2002-01-01

    Provides ways for students to demonstrate their understanding of scientific concepts and skills. Describes a mini-unit around the cold in which students can relate humans to viruses. Includes activities and a modified simulation that provides questions to guide students. Discusses ways that allows students to apply prior knowledge, take ownership…

  3. Breeding Cold Hardy Begonias

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hardy begonia cultivars have potential as a new crop for Southern nurseries. Current begonia breeding efforts are focused on sections Begonia and Pritzelia. Diverse begonia germplasm has been collected to study fertility and hardiness.To date cold hardy germplasm which has produced viable seeds inc...

  4. Recent Cold War Studies

    ERIC Educational Resources Information Center

    Pineo, Ronn

    2003-01-01

    Cold War historiography has undergone major changes since the 1991 collapse of the Soviet Union. For two years (1992-1993) the principal Soviet archives fell open to scholars, and although some of the richest holdings are now once again closed, new information continues to find its way out. Moreover, critical documentary information has become…

  5. Teaching "In Cold Blood."

    ERIC Educational Resources Information Center

    Berbrich, Joan D.

    1967-01-01

    The Truman Capote nonfiction novel, "In Cold Blood," which reflects for adolescents the immediacy of the real world, illuminates (1) social issues--capital punishment, environmental influence, and the gap between the "haves" and "have-nots," (2) moral issues--the complexity of man's nature, the responsibility of one man for another, and the place…

  6. Titanium Cold Spray Coatings

    NASA Astrophysics Data System (ADS)

    Ajaja, Jihane; Goldbaum, Dina; Chromik, Richard; Yue, Stephen; Rezaeian, Ahmad; Wong, Wilson; Irissou, Eric; Legoux, Jean-Gabriel

    Titanium Cold Spray Coatings Cold Spray is an emerging technology used for the deposition of coatings for many industries including aerospace. This technique allows the deposition of metallic materials at low temper-atures below their melting point. The aim of this research was to develop a test technique that can measure the degree to which a cold spray coating achieves mechanical properties similar to a traditional bulk material. Vickers hardness testing and nanoindentation were used as micro-and nano-scale measurement techniques to characterize the mechanical properties of titanium coatings, deposited at different deposition conditions, and bulk Ti. The mechanical properties of bulk titanium and titanium coatings were measured over a range of length scales, with the indentation size effect examined with Meyer's law. Hardness measurements are shown to be affected by material porosity, microstructure and coating particle bonding mechanism. Hard-ness measurements showed that Ti coatings deposited at higher gas pressures and temperatures demonstrate an indentation load response similar to bulk Ti. Key words: titanium, cold spray, Vickers hardness, nanoindentation, indentation size effect, microstructure, mechanical properties

  7. Diffraction by cold atoms

    NASA Astrophysics Data System (ADS)

    Strauch, F.; Gomer, V.; Schadwinkel, H.; Ueberholz, B.; Haubrich, D.; Meschede, D.

    1998-01-01

    We have observed diffraction of a laser probe beam by a trapped sample of cold atoms. The effect is only visible in the vicinity of a resonance line. The observed diffraction pattern arises from interference of the incident and scattered light wave, allowing reconstruction of geometric properties of the trapped sample from the holographic record.

  8. Expert Cold Structure Development

    NASA Astrophysics Data System (ADS)

    Atkins, T.; Demuysere, P.

    2011-05-01

    The EXPERT Program is funded by ESA. The objective of the EXPERT mission is to perform a sub-orbital flight during which measurements of critical aero- thermodynamic phenomena will be obtained by using state-of-the-art instrumentation. As part of the EXPERT Flight Segment, the responsibility of the Cold Structure Development Design, Manufacturing and Validation was committed to the Belgian industrial team SONACA/SABCA. The EXPERT Cold Structure includes the Launcher Adapter, the Bottom Panel, the Upper Panel, two Cross Panels and the Parachute Bay. An additional Launcher Adapter was manufactured for the separation tests. The selected assembly definition and manufacturing technologies ( machined parts and sandwich panels) were dictated classically by the mass and stiffness, but also by the CoG location and the sensitive separation interface. Used as support for the various on-board equipment, the Cold Structure is fixed to but thermally uncoupled from the PM 1000 thermal shield. It is protect on its bottom panel by a thermal blanket. As it is a protoflight, analysis was the main tool for the verification. Low level stiffness and modal analysis tests have also been performed on the Cold Structure equipped with its ballast. It allowed to complete its qualification and to prepare SONACA/SABCA support for the system dynamic tests foreseen in 2011. The structure was finally coated with a thermal control black painting and delivered on time to Thales Alenia Space-Italy end of March 201.

  9. Cold War Propaganda.

    ERIC Educational Resources Information Center

    Bennett, Paul W.

    1988-01-01

    Briefly discusses the development of Cold War propaganda in the United States, Canada, and the USSR after 1947. Presents two movie reviews and a Canadian magazine advertisement of the period which illustrate the harshness of propaganda used by both sides in the immediate postwar years. (GEA)

  10. Modulation of the Bovine Innate Immune Response by Production of 1alpha,25-Dihydroxyvitamin D3 in Bovine Monocytes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In cattle, the kidney has been the only known site for production of 1,25-dihydroxyvitamin D3 (1,25[OH]2D3) from 25-hydroxyvitamin D3 25(OH)D3 by 1alpha-hydroxylase (1alpha-OHase). However, recent studies have shown that human monocytes express 1alpha-OHase and produce 1,25(OH)2D3 in response to to...

  11. Microstructure and Mechanical Properties of Laser Clad and Post-cladding Tempered AISI H13 Tool Steel

    NASA Astrophysics Data System (ADS)

    Telasang, Gururaj; Dutta Majumdar, Jyotsna; Wasekar, Nitin; Padmanabham, G.; Manna, Indranil

    2015-05-01

    This study reports a detailed investigation of the microstructure and mechanical properties (wear resistance and tensile strength) of hardened and tempered AISI H13 tool steel substrate following laser cladding with AISI H13 tool steel powder in as-clad and after post-cladding conventional bulk isothermal tempering [at 823 K (550 °C) for 2 hours] heat treatment. Laser cladding was carried out on AISI H13 tool steel substrate using a 6 kW continuous wave diode laser coupled with fiber delivering an energy density of 133 J/mm2 and equipped with a co-axial powder feeding nozzle capable of feeding powder at the rate of 13.3 × 10-3 g/mm2. Laser clad zone comprises martensite, retained austenite, and carbides, and measures an average hardness of 600 to 650 VHN. Subsequent isothermal tempering converted the microstructure into one with tempered martensite and uniform dispersion of carbides with a hardness of 550 to 650 VHN. Interestingly, laser cladding introduced residual compressive stress of 670 ± 15 MPa, which reduces to 580 ± 20 MPa following isothermal tempering. Micro-tensile testing with specimens machined from the clad zone across or transverse to cladding direction showed high strength but failure in brittle mode. On the other hand, similar testing with samples sectioned from the clad zone parallel or longitudinal to the direction of laser cladding prior to and after post-cladding tempering recorded lower strength but ductile failure with 4.7 and 8 pct elongation, respectively. Wear resistance of the laser surface clad and post-cladding tempered samples (evaluated by fretting wear testing) registered superior performance as compared to that of conventional hardened and tempered AISI H13 tool steel.

  12. Effect of coatings obtanied by sputtering of chromium catode on the corrosion resistance of AISI H13 steel

    NASA Astrophysics Data System (ADS)

    Sandoval, A.; Peña, D.; Piratoba, U.

    2013-11-01

    Corrosion resistance of coatings obtained by sputtering a chromium target were evaluated. The films were deposited on substrates of disk-shaped AISI H13 steel. By means of potentiodynamic polarization curves were able to determine the current density vs. potential for the coated and uncoated substrate and the difference in the corrosion potential Ecorr. All samples with coating showed an increase in Ecorr respect to substrate. The electrochemical tests were conducted in an electrolytic solution of 3% NaCl.

  13. Surface fatigue life of M50NiL and AISI 9310 spur gears and R C bars

    NASA Technical Reports Server (NTRS)

    Townsend, Dennis P.; Bamberger, Eric N.

    1991-01-01

    Spur gear endurance tests and rolling element surface fatigue tests were conducted to study vacuum induction melted, vacuum arc remelted (VIM-VAR) M50NiL steel for use as a gear steel in advanced aircraft applications, to determine its endurance characteristics, and to compare the results with those for standard VAR and VIM-VAR AISI 9310 gear material. Tests were conducted with spur gears and rolling contact bars manufactured from VIM-VAR M50NiL and VAR and VIM-VAR AISI 9310. The gear pitch diameter was 8.9 cm. Gear test conditions were an inlet oil temperature of 320 K, and outlet oil temperature of 350 K, a maximum Hertz stress of 1.71 GPa, and a speed of 10000 rpm. Bench rolling element fatigue tests were conducted at ambient temperatures with a bar speed of 12,500 rpm and a maximum Hertz stress of 4.83 GPa. The VIM-VAR M50NiL gears had a surface fatigue life that was 4.5 and 11.5 times that for VIM-VAR and VAR AISI 9310 gears, respectively. The surface fatigue life of the VIM-VAR M50NiL rolling contact bars was 13.2 and 21.6 times that for the VIM-VAR and VAR AISI 9310, respectively. The VIM-VAR M50NiL material was shown to have good resistance to fracture through a fatigue spall and superior fatigue life to both other gears.

  14. Ubiquitination and degradation of the hominoid-specific oncoprotein TBC1D3 is regulated by protein palmitoylation

    SciTech Connect

    Kong, Chen; Lange, Jeffrey J.; Samovski, Dmitri; Su, Xiong; Liu, Jialiu; Sundaresan, Sinju; Stahl, Philip D.

    2013-05-03

    Highlights: •Hominoid-specific oncogene TBC1D3 is targeted to plasma membrane by palmitoylation. •TBC1D3 is palmitoylated on two cysteine residues: 318 and 325. •TBC1D3 palmitoylation governs growth factors-induced TBC1D3 degradation. •Post-translational modifications may regulate oncogenic properties of TBC1D3. -- Abstract: Expression of the hominoid-specific oncoprotein TBC1D3 promotes enhanced cell growth and proliferation by increased activation of signal transduction through several growth factors. Recently we documented the role of CUL7 E3 ligase in growth factors-induced ubiquitination and degradation of TBC1D3. Here we expanded our study to discover additional molecular mechanisms that control TBC1D3 protein turnover. We report that TBC1D3 is palmitoylated on two cysteine residues: 318 and 325. The expression of double palmitoylation mutant TBC1D3:C318/325S resulted in protein mislocalization and enhanced growth factors-induced TBC1D3 degradation. Moreover, ubiquitination of TBC1D3 via CUL7 E3 ligase complex was increased by mutating the palmitoylation sites, suggesting that depalmitoylation of TBC1D3 makes the protein more available for ubiquitination and degradation. The results reported here provide novel insights into the molecular mechanisms that govern TBC1D3 protein degradation. Dysregulation of these mechanisms in vivo could potentially result in aberrant TBC1D3 expression and promote oncogenesis.

  15. Plasma nitriding process by direct current glow discharge at low temperature increasing the thermal diffusivity of AISI 304 stainless steel

    SciTech Connect

    Prandel, L. V.; Somer, A.; Assmann, A.; Camelotti, F.; Costa, G.; Bonardi, C.; Jurelo, A. R.; Rodrigues, J. B.; Cruz, G. K.

    2013-02-14

    This work reports for the first time on the use of the open photoacoustic cell technique operating at very low frequencies and at room temperature to experimentally determine the thermal diffusivity parameter of commercial AISI304 stainless steel and AISI304 stainless steel nitrided samples. Complementary measurements of X-ray diffraction and scanning electron microscopy were also performed. The results show that in standard AISI 304 stainless steel samples the thermal diffusivity is (4.0 {+-} 0.3) Multiplication-Sign 10{sup -6} m{sup 2}/s. After the nitriding process, the thermal diffusivity increases to the value (7.1 {+-} 0.5) Multiplication-Sign 10{sup -6} m{sup 2}/s. The results are being associated to the diffusion process of nitrogen into the surface of the sample. Carrying out subsequent thermal treatment at 500 Degree-Sign C, the thermal diffusivity increases up to (12.0 {+-} 2) Multiplication-Sign 10{sup -6} m{sup 2}/s. Now the observed growing in the thermal diffusivity must be related to the change in the phases contained in the nitrided layer.

  16. Wear and Adhesive Failure of Al2O3 Powder Coating Sprayed onto AISI H13 Tool Steel Substrate

    NASA Astrophysics Data System (ADS)

    Amanov, Auezhan; Pyun, Young-Sik

    2016-04-01

    In this study, an alumina (Al2O3) ceramic powder was sprayed onto an AISI H13 hot-work tool steel substrate that was subjected to sanding and ultrasonic nanocrystalline surface modification (UNSM) treatment processes. The significance of the UNSM technique on the adhesive failure of the Al2O3 coating and on the hardness of the substrate was investigated. The adhesive failure of the coating sprayed onto sanded and UNSM-treated substrates was investigated by a micro-scratch tester at an incremental load. It was found, based on the obtained results, that the coating sprayed onto the UNSM-treated substrate exhibited a better resistance to adhesive failure in comparison with that of the coating sprayed onto the sanded substrate. Dry friction and wear property of the coatings sprayed onto the sanded and UNSM-treated substrates were assessed by means of a ball-on-disk tribometer against an AISI 52100 steel ball. It was demonstrated that the UNSM technique controllably improved the adhesive failure of the Al2O3 coating, where the critical load was improved by about 31%. Thus, it is expected that the application of the UNSM technique to an AISI H13 tool steel substrate prior to coating may delay the adhesive failure and improve the sticking between the coating and the substrate thanks to the modified and hardened surface.

  17. Wear and Adhesive Failure of Al2O3 Powder Coating Sprayed onto AISI H13 Tool Steel Substrate

    NASA Astrophysics Data System (ADS)

    Amanov, Auezhan; Pyun, Young-Sik

    2016-07-01

    In this study, an alumina (Al2O3) ceramic powder was sprayed onto an AISI H13 hot-work tool steel substrate that was subjected to sanding and ultrasonic nanocrystalline surface modification (UNSM) treatment processes. The significance of the UNSM technique on the adhesive failure of the Al2O3 coating and on the hardness of the substrate was investigated. The adhesive failure of the coating sprayed onto sanded and UNSM-treated substrates was investigated by a micro-scratch tester at an incremental load. It was found, based on the obtained results, that the coating sprayed onto the UNSM-treated substrate exhibited a better resistance to adhesive failure in comparison with that of the coating sprayed onto the sanded substrate. Dry friction and wear property of the coatings sprayed onto the sanded and UNSM-treated substrates were assessed by means of a ball-on-disk tribometer against an AISI 52100 steel ball. It was demonstrated that the UNSM technique controllably improved the adhesive failure of the Al2O3 coating, where the critical load was improved by about 31%. Thus, it is expected that the application of the UNSM technique to an AISI H13 tool steel substrate prior to coating may delay the adhesive failure and improve the sticking between the coating and the substrate thanks to the modified and hardened surface.

  18. Plasma nitriding process by direct current glow discharge at low temperature increasing the thermal diffusivity of AISI 304 stainless steel

    NASA Astrophysics Data System (ADS)

    Prandel, L. V.; Somer, A.; Assmann, A.; Camelotti, F.; Costa, G.; Bonardi, C.; Jurelo, A. R.; Rodrigues, J. B.; Cruz, G. K.

    2013-02-01

    This work reports for the first time on the use of the open photoacoustic cell technique operating at very low frequencies and at room temperature to experimentally determine the thermal diffusivity parameter of commercial AISI304 stainless steel and AISI304 stainless steel nitrided samples. Complementary measurements of X-ray diffraction and scanning electron microscopy were also performed. The results show that in standard AISI 304 stainless steel samples the thermal diffusivity is (4.0 ± 0.3) × 10-6 m2/s. After the nitriding process, the thermal diffusivity increases to the value (7.1 ± 0.5) × 10-6 m2/s. The results are being associated to the diffusion process of nitrogen into the surface of the sample. Carrying out subsequent thermal treatment at 500 °C, the thermal diffusivity increases up to (12.0 ± 2) × 10-6 m2/s. Now the observed growing in the thermal diffusivity must be related to the change in the phases contained in the nitrided layer.

  19. Thermoregulatory modeling for cold stress.

    PubMed

    Xu, Xiaojiang; Tikuisis, Peter

    2014-07-01

    Modeling for cold stress has generated a rich history of innovation, has exerted a catalytic influence on cold physiology research, and continues to impact human activity in cold environments. This overview begins with a brief summation of cold thermoregulatory model development followed by key principles that will continue to guide current and future model development. Different representations of the human body are discussed relative to the level of detail and prediction accuracy required. In addition to predictions of shivering and vasomotor responses to cold exposure, algorithms are presented for thermoregulatory mechanisms. Various avenues of heat exchange between the human body and a cold environment are reviewed. Applications of cold thermoregulatory modeling range from investigative interpretation of physiological observations to forecasting skin freezing times and hypothermia survival times. While these advances have been remarkable, the future of cold stress modeling is still faced with significant challenges that are summarized at the end of this overview. PMID:24944030

  20. Prescription Drugs and Cold Medicines

    MedlinePlus

    ... Abuse » Prescription Drugs & Cold Medicines Prescription Drugs & Cold Medicines Email Facebook Twitter What is Prescription Drug Abuse: ... treatment of addiction. Read more Safe Disposal of Medicines Disposal of Unused Medicines: What You Should Know ( ...

  1. Palmitoylation on the carboxyl terminus tail is required for the selective regulation of dopamine D2 versus D3 receptors.

    PubMed

    Zhang, Xiaowei; Le, Hang Thi; Zhang, Xiaohan; Zheng, Mei; Choi, Bo-Gil; Kim, Kyeong-Man

    2016-09-01

    Dopamine D2 receptor (D2R) and D3 receptor (D3R) possess highly conserved amino acid sequences but this study showed that D3R was more extensively palmitoylated than D2R. Based on this finding, the molecular basis of this selective palmitoylation of D3R was determined and the roles of palmitoylation in the regulation of D3R functions were investigated. D3R was palmitoylated on the cysteine residue on its carboxyl terminus tail, the last amino acid residue of D3R, and an exchange of the carboxyl terminus tail between D2R and D3R (D2R-D3C and D3R-D2C) resulted in the switching of the palmitoylation phenotype. When the consensus site for palmitoylation was mutated or the palmitoylation of D3R was inhibited by treatment with 2-bromopalmitate (2BP), a palmitoylation blocker, cell-surface expression, PKC-mediated endocytosis, agonist affinity, and agonist-induced tolerance of D3R were all inhibited. However, these changes were not observed when D3R palmitoylation was inhibited by replacing its carboxyl tail with that of D2R (D3R-D2C) or when the palmitoylation of D2R-D3C was inhibited by treatment with 2BP. Overall, this study shows that D3R is palmitoylated more extensively than D2R even though the carboxyl terminus tails of D2R and D3R are highly homologous, and thus provides a new clue regarding the consensus sequence for palmitoylation. This study also shows that palmitoylation controls various functionalities of D3R only when the receptor is in the intact D3R configuration. PMID:27349735

  2. Imaging with cold neutrons

    NASA Astrophysics Data System (ADS)

    Lehmann, E. H.; Kaestner, A.; Josic, L.; Hartmann, S.; Mannes, D.

    2011-09-01

    Neutrons for imaging purposes are provided mainly from thermal beam lines at suitable facilities around the world. The access to cold neutrons is presently limited to very few places only. However, many challenging options for imaging with cold neutrons have been found out, given by the interaction behavior of the observed materials with neutrons in the cold energy range (3-10 Å). For absorbing materials, the interaction probability increases proportionally with the wavelength with the consequence of more contrast but less transmission with cold neutrons. Many materials are predominantly scattering neutrons, in particular most of crystalline structural materials. In these cases, cold neutrons play an important role by covering the energy range of the most important Bragg edges given by the lattice planes of the crystallites. This particular behavior can be used for at least two important aspects—choosing the right energy of the initial beam enables to have a material more or less transparent, and a direct macroscopic visualization of the crystalline structure and its change in a manufacturing process. Since 2006, PSI operates its second beam line for neutron imaging, where cold neutrons are provided from a liquid deuterium cold source (operated at 25 K). It has been designed to cover the most current aspects in neutron imaging research with the help of high flexibility. This has been done with changeable inlet apertures, a turbine based velocity selector, two beam positions and variable detector systems, satisfying the demands of the individual investigation. The most important detection system was found to be a micro-tomography system that enables studies in the presently best spatial resolution. In this case, the high contrast from the sample interaction process and the high detection probability for the cold neutrons combines in an ideal combination for the best possible performance. Recently, it was found out that the energy selective studies might become a

  3. E3-brane instantons and baryonic operators for D3-branes on toric singularities

    NASA Astrophysics Data System (ADS)

    Forcella, Davide; García-Etxebarria, Iñaki; Uranga, Angel

    2009-03-01

    We consider the couplings induced on the world-volume field theory of D3-branes at local toric Calabi-Yau singularities by euclidean D3-brane (E3-brane) instantons wrapped on (non-compact) holomorphic 4-cycles. These instantons produce insertions of BPS baryonic or mesonic operators of the four-dimensional Script N = 1 quiver gauge theory. We argue that these systems underlie, via the near-horizon limit, the familiar AdS/CFT map between BPS operators and D3-branes wrapped on supersymmetric 3-cycles on the 5d horizon. The relation implies that there must exist E3-brane instantons with appropriate fermion mode spectrum and couplings, such that their non-perturbative effects on the D3-branes induce operators forming a generating set for all BPS operators of the quiver CFT. We provide a constructive argument for this correspondence, thus supporting the picture.

  4. D3 receptor test in vitro predicts decreased cocaine self-administration in rats.

    PubMed

    Caine, S B; Koob, G F; Parsons, L H; Everitt, B J; Schwartz, J C; Sokoloff, P

    1997-07-01

    The three dopamine agonists with highest reported D3 receptor selectivity in vitro, pramipexole, quinelorane and PD128,907, decreased self-administration of a high dose of cocaine in rats as a result of a leftward shift in the cocaine dose-effect function. In contrast the D3 preferring antagonist nafadotride increased cocaine self-administration. Moreover the relative potencies of these and other D2-like dopamine agonists (lisuride, 7-OH-DPAT, quinpirole, apomorphine, bromocriptine) to modulate cocaine self-administration were highly correlated with their relative potencies for increasing mitogenesis in vitro in cell lines expressing D3 but not D2 receptors. These results support the hypothesis that the D3 receptor may be an important target for pharmacotherapies for cocaine abuse and dependence. PMID:9243643

  5. Regulation of human tonsillar T-cell proliferation by the active metabolite of vitamin D3.

    PubMed Central

    Nunn, J D; Katz, D R; Barker, S; Fraher, L J; Hewison, M; Hendy, G N; O'Riordan, J L

    1986-01-01

    We have examined the effects of 1,25(OH)2D3 on T-cell populations isolated by buoyant density and E rosetting from human tonsils. Cell proliferation was assessed by measuring the incorporation of 125iododeoxyuridine; interleukin-2 (IL-2) production was measured using an IL-2-dependent cell line, and the number of 1,25(OH)2D3 receptors was measured by whole-cell nuclear association assay. At a concentration of 10(-7) M, 1,25(OH)2D3 inhibited mitogen-induced T-cell proliferation in all E+ T-cell populations. This effect was more pronounced in the cells from the intermediate and high density layers and was reflected both in cell proliferative responses and in relative IL-2 synthesis. By adding the 1,25(OH)2D3 during the course of the mitogen assay, we demonstrated that activation of the T cell precedes the 1,25(OH)2D3-mediated inhibition. Cells that had been preincubated with mitogen in the presence of the 1,25(OH)2D3 were refractory to further stimulation by mitogens. Receptors for 1,25(OH)2D3 could not be detected in unstimulated T cells. However, activation led to the expression of high-affinity receptors for 1,25(OH)2D3. Co-incubation of the cells with mitogen and 1,25(OH)2D3 increased the number of receptors compared with mitogen alone. The effects provide further evidence for the hypothesis that 1,25(OH)2D3 is an important potential modulator of the immune system through its action on T cells. Taking our observations in conjunction with the known capacity of monocytes to hydroxylate the precursor metabolite (and thus synthesize the active form of cholecalciferol), the results support the suggestion that 1,25(OH)2D3 plays a role as a local mediator of mononuclear phagocyte-T cell interaction in human lymphomedullary tissues. PMID:3026959

  6. Regulation of Mycobacterium-specific mononuclear cell responses by 25-hydroxyvitamin D3.

    PubMed

    Nelson, Corwin D; Nonnecke, Brian J; Reinhardt, Timothy A; Waters, W Ray; Beitz, Donald C; Lippolis, John D

    2011-01-01

    The active vitamin D metabolite, 1,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3)), has been shown to be an important regulator of innate and adaptive immune function. In addition, synthesis of 1,25(OH)(2)D(3) from 25-hydroxyvitamin D(3) (25(OH)D(3)) by the enzyme 1α-hydroxylase in monocytes upon activation by TLR signaling has been found to regulate innate immune responses of monocytes in an intracrine fashion. In this study we wanted to determine what cells expressed 1α-hydroxylase in stimulated peripheral blood mononuclear cell (PBMC) cultures and if conversion of 25(OH)D(3) to 1,25(OH)(2)D(3) in PBMC cultures regulated antigen-specific immune responses. Initially, we found that stimulation of PBMCs from animals vaccinated with Mycobacterium bovis (M. bovis) BCG with purified protein derivative of M. bovis (M. bovis PPD) induced 1α-hydroxylase gene expression and that treatment with a physiological concentration of 25(OH)D(3) down-regulated IFN-γ and IL-17F gene expression. Next, we stimulated PBMCs from M. bovis BCG-vaccinated and non-vaccinated cattle with M. bovis PPD and sorted them by FACS according to surface markers for monocytes/macrophages (CD14), B cells (IgM), and T cells (CD3). Sorting the PBMCs revealed that 1α-hydroxylase expression was induced in the monocytes and B cells, but not in the T cells. Furthermore, treatment of stimulated PBMCs with 25(OH)D(3) down-regulated antigen-specific IFN-γ and IL-17F responses in the T cells, even though 1α-hydroxylase expression was not induced in the T cells. Based on evidence of no T cell 1α-hydroxylase we hypothesize that activated monocytes and B cells synthesize 1,25(OH)(2)D(3) and that 1,25(OH)(2)D(3) down-regulates antigen-specific expression of IFN-γ and IL-17F in T cells in a paracrine fashion. PMID:21738762

  7. Local Sustained Delivery of 25-Hydroxyvitamin D3 for Production of Antimicrobial Peptides

    PubMed Central

    Jiang, Jiang; Chen, Guojun; Shuler, Franklin D.; Wang, Chi-Hwa; Xie, Jingwei

    2015-01-01

    Purpose This study seeks to develop fiber membranes for local sustained delivery of 25-hydroxyvitamin D3 to induce the expression and secretion of LL-37 at or near the surgical site, which provides a novel therapeutic approach to minimize the risk of infections. Methods 25-hydroxyvitamin D3 loaded poly(L-lactide) (PLA) and poly(ε-caprolactone) (PCL) fibers were produced by electrospinning. The morphology of obtained fibers was characterized using atomic force microscope (AFM) and scanning electron microscope (SEM). 25-hydroxyvitamin D3 releasing kinetics were quantified by enzyme-linked immunosorbent assay (ELISA) kit. The expression of cathelicidin (hCAP 18) and LL-37 was analyzed by immunofluorescence staining and ELISA kit. The antibacterial activity test was conducted by incubating pseudomonas aeruginosa in a monocytes’ lysis solution. Results AFM images suggest that the surface of PCL fibers is smooth, however, the surface of PLA fibers is relatively rough, in particular, after encapsulation of 25-hydroxyvitamin D3. The duration of 25-hydroxyvitamin D3 release can last more than 4 weeks for all the tested samples. Plasma treatment can promote the release rate of 25-hydroxyvitamin D3. Human keratinocytes and monocytes express significantly higher levels of hCAP18/LL-37 after incubation with plasma treated and 25-hydroxyvitamin D3 loaded PCL fibers than the cells incubated with around 10 times amount of free drug. After incubation with this fiber formulation for 5 days LL-37 in the lysis solutions of U937 cells can effectively kill the bacteria. Conclusions plasma treated and 25-hydroxyvitamin D3 loaded PCL fibers induce significantly higher levels of antimicrobial peptide production in human keratinocytes and monocytes without producing cytotoxicity. PMID:25773720

  8. Vitamin D3 attenuates oxidative stress and cognitive deficits in a model of toxic demyelination

    PubMed Central

    Tarbali, Sepideh; Khezri, Shiva

    2016-01-01

    Objective(s): Multiple sclerosis (MS) is a demyelinating disease. The prevalence of MS is highest where environmental supplies of vitamin D are low. Cognitive deficits have been observed in patients with MS. Oxidative damage may contribute to the formation of MS lesions. Considering the involvement of hippocampus in MS, an attempt is made in this study to investigate the effects of vitamin D3 on behavioral process and the oxidative status in the dorsal hippocampus (CA1 area) following the induction of experimental demyelination in rats. Materials and Methods: Animals were divided into six groups. Control group: animals received no surgery and treatment; saline group: animals received normal saline; sham group: animals received 150 μl sesame oil IP; vitamin D3 group: animals received 5 μg/kg vitamin D3 IP; lysophosphatidyl choline (LPC) group (toxic demyelination’s model): animals received LPC by stereotaxic intra-hippocampal injection of 2 μl LPC in CA1 area; Vitamin D3- treated group: animals were treated with vitamin D3 at doses of 5 μg/kg IP for 7 and 21 days post lesion. The spatial memory, biochemical parameters including catalase (CAT) activities and lipid peroxidation levels were investigated. Results: Animals in LPC group had more deficits in spatial memory than the control group in radial arm maze. Vitamin D3 significantly improved spatial memory compared to LPC group. Also, results indicated that vitamin D3 caused a decrease in lipid peroxidation levels and an increase in CAT activities. Conclusion: Current findings suggest that vitamin D3 may have a protective effect on cognitive deficits and oxidative stress in toxic demyelination’s model. PMID:27096068

  9. Overexpression of the dopamine D3 receptor in the rat dorsal striatum induces dyskinetic behaviors.

    PubMed

    Cote, Samantha R; Chitravanshi, Vineet C; Bleickardt, Carina; Sapru, Hreday N; Kuzhikandathil, Eldo V

    2014-04-15

    L-DOPA-induced dyskinesias (LID) are motor side effects associated with treatment of Parkinson's disease (PD). The etiology of LID is not clear; however, studies have shown that the dopamine D3 receptor is upregulated in the basal ganglia of mice, rats and non-human primate models of LID. It is not known if the upregulation of D3 receptor is a cause or result of LID. In this paper we tested the hypothesis that overexpression of the dopamine D3 receptor in dorsal striatum, in the absence of dopamine depletion, will elicit LID. Replication-deficient recombinant adeno-associated virus-2 expressing the D3 receptor or enhanced green fluorescent protein (EGFP) were stereotaxically injected, unilaterally, into the dorsal striatum of adult rats. Post-hoc immunohistochemical analysis revealed that ectopic expression of the D3 receptor was limited to neurons near the injection sites in the dorsal striatum. Following a 3-week recovery period, rats were administered saline, 6 mg/kg L-DOPA, 0.1 mg/kg PD128907 or 10 mg/kg ES609, i.p., and motor behaviors scored. Rats overexpressing the D3 receptor specifically exhibited contralateral axial abnormal involuntary movements (AIMs) following administration of L-DOPA and PD128907 but not saline or the novel agonist ES609. Daily injection of 6 mg/kg L-DOPA to the rats overexpressing the D3 receptor also caused increased vacuous chewing behavior. These results suggest that overexpression of the D3 receptor in the dorsal striatum results in the acute expression of agonist-induced axial AIMs and chronic L-DOPA-induced vacuous chewing behavior. Agonists such as ES609 might provide a novel therapeutic approach to treat dyskinesia. PMID:24462727

  10. Caffeine increases striatal dopamine D2/D3 receptor availability in the human brain

    PubMed Central

    Volkow, N D; Wang, G-J; Logan, J; Alexoff, D; Fowler, J S; Thanos, P K; Wong, C; Casado, V; Ferre, S; Tomasi, D

    2015-01-01

    Caffeine, the most widely consumed psychoactive substance in the world, is used to promote wakefulness and enhance alertness. Like other wake-promoting drugs (stimulants and modafinil), caffeine enhances dopamine (DA) signaling in the brain, which it does predominantly by antagonizing adenosine A2A receptors (A2AR). However, it is unclear if caffeine, at the doses consumed by humans, increases DA release or whether it modulates the functions of postsynaptic DA receptors through its interaction with adenosine receptors, which modulate them. We used positron emission tomography and [11C]raclopride (DA D2/D3 receptor radioligand sensitive to endogenous DA) to assess if caffeine increased DA release in striatum in 20 healthy controls. Caffeine (300 mg p.o.) significantly increased the availability of D2/D3 receptors in putamen and ventral striatum, but not in caudate, when compared with placebo. In addition, caffeine-induced increases in D2/D3 receptor availability in the ventral striatum were associated with caffeine-induced increases in alertness. Our findings indicate that in the human brain, caffeine, at doses typically consumed, increases the availability of DA D2/D3 receptors, which indicates that caffeine does not increase DA in the striatum for this would have decreased D2/D3 receptor availability. Instead, we interpret our findings to reflect an increase in D2/D3 receptor levels in striatum with caffeine (or changes in affinity). The association between increases in D2/D3 receptor availability in ventral striatum and alertness suggests that caffeine might enhance arousal, in part, by upregulating D2/D3 receptors. PMID:25871974

  11. Caffeine increases striatal dopamine D2/D3 receptor availability in the human brain

    DOE PAGESBeta

    Volkow, N. D.; Wang, G. -J.; Logan, J.; Alexoff, D.; Fowler, J. S.; Thanos, P. K.; Wong, C.; Casado, V.; Ferre, S.; Tomasi, D.

    2015-04-14

    Caffeine, the most widely consumed psychoactive substance in the world, is used to promote wakefulness and enhance alertness. Like other wake-promoting drugs (stimulants and modafinil), caffeine enhances dopamine (DA) signaling in the brain, which it does predominantly by antagonizing adenosine A2A receptors (A2AR). However, it is unclear if caffeine, at the doses consumed by humans, increases DA release or whether it modulates the functions of postsynaptic DA receptors through its interaction with adenosine receptors, which modulate them. We used positron emission tomography and [11C]raclopride (DA D2/D3 receptor radioligand sensitive to endogenous DA) to assess if caffeine increased DA release inmore » striatum in 20 healthy controls. Caffeine (300mg p.o.) significantly increased the availability of D2/D3 receptors in putamen and ventral striatum, but not in caudate, when compared with placebo. In addition, caffeine-induced increases in D2/D3 receptor availability in the ventral striatum were associated with caffeine-induced increases in alertness. Our findings indicate that in the human brain, caffeine, at doses typically consumed, increases the availability of DA D2/D3 receptors, which indicates that caffeine does not increase DA in the striatum for this would have decreased D2/D3 receptor availability. Instead, we interpret our findings to reflect an increase in D2/D3 receptor levels in striatum with caffeine (or changes in affinity). Furthermore, the association between increases in D2/D3 receptor availability in ventral striatum and alertness suggests that caffeine might enhance arousal, in part, by upregulating D2/D3 receptors.« less

  12. Examining the role of dopamine D2 and D3 receptors in Pavlovian conditioned approach behaviors.

    PubMed

    Fraser, Kurt M; Haight, Joshua L; Gardner, Eliot L; Flagel, Shelly B

    2016-05-15

    Elucidating the neurobiological mechanisms underlying individual differences in the extent to which reward cues acquire the ability to act as incentive stimuli may contribute to the development of successful treatments for addiction and related disorders. We used the sign-tracker/goal-tracker animal model to examine the role of dopamine D2 and D3 receptors in the propensity to attribute incentive salience to reward cues. Following Pavlovian training, wherein a discrete lever-cue was paired with food reward, rats were classified as sign- or goal-trackers based on the resultant conditioned response. We examined the effects of D2/D3 agonists, 7-OH-DPAT (0.01-0.32mg/kg) or pramipexole (0.032-0.32mg/kg), the D2/D3 antagonist raclopride (0.1mg/kg), and the selective D3 antagonist, SB-277011A (6 or 24mg/kg), on the expression of sign- and goal-tracking conditioned responses. The lever-cue acquired predictive value and elicited a conditioned response for sign- and goal-trackers, but only for sign-trackers did it also acquire incentive value. Following administration of either 7-OH-DPAT, pramipexole, or raclopride, the performance of the previously acquired conditioned response was attenuated for both sign- and goal-trackers. For sign-trackers, the D2/D3 agonist, 7-OH-DPAT, also attenuated the conditioned reinforcing properties of the lever-cue. The selective D3 antagonist did not affect either conditioned response. Alterations in D2/D3 receptor signaling, but not D3 signaling alone, transiently attenuate a previously acquired Pavlovian conditioned response, regardless of whether the response is a result of incentive motivational processes. These findings suggest activity at the dopamine D2 receptor is critical for a reward cue to maintain either its incentive or predictive qualities. PMID:26909847

  13. Blood mineral, hormone, and osteocalcin responses of multiparous Jersey cows to an oral dose of 25-hydroxyvitamin D3 or vitamin D3 before parturition.

    PubMed

    Taylor, M S; Knowlton, K F; McGilliard, M L; Seymour, W M; Herbein, J H

    2008-06-01

    Twenty-seven multiparous Jersey cows were randomly assigned to receive an oral bolus containing corn starch (control, CON), corn starch plus 15 mg of 25-hydroxyvitamin D(3) (25-OH), or 15 mg of cholecalciferol (D(3)) at 6 d before expected parturition. Cows were maintained in individual box stalls from 20 d before expected parturition and fed a common diet. Jugular blood samples were collected at -14, -13, -5, -4, -3, -2, -1 d before expected calving, at calving, and at 1, 3, 5, 7, 9, 11, 13, 28, 56, and 84 d postcalving. After calving, cows were housed in 1 pen in a free-stall barn and consumed a common diet. Colorimetric assays were used to analyze Ca, P, and Mg concentrations in serum. Serum concentrations of osteocalcin (OC), an indicator of bone formation, serum 25-hydroxyvitamin D(3), and parathyroid hormone (PTH) were determined in samples obtained from d -5 through d 13. The 9 control multiparous cows and 5 untreated primiparous cows were used to evaluate the effect of parity on the variables that were measured. There was no effect of parity on Ca, PTH, or 25-OH concentration. Compared with second-lactation cows and older cows (>2 lactations), first-lactation cows had greater serum OC (22.3, 32.0, and 48.3 ng/mL, respectively), indicating that younger animals were forming more bone. Blood Ca, P, and Mg decreased near the time of calving and then increased over time. Serum 25-hydroxyvitamin D(3) was greater for cows dosed with 25-OH (119.0 ng/mL) compared with those dosed with D(3) (77.5 ng/mL) or CON (69.3 ng/mL). Cows dosed with 25-OH tended to have lower serum PTH concentration, but treatments did not affect serum Ca, P, or Mg. Serum OC was greater in second-lactation cows compared with cows entering their third or fourth lactation but OC was unaffected by treatment. Although results indicated a 60% increase in serum 25-hydroxyvitamin D(3) due to a single oral dose of 25-OH before calving, the amount administered in this study apparently was not

  14. Health problems in cold work.

    PubMed

    Mäkinen, Tiina M; Hassi, Juhani

    2009-07-01

    Cold in- and outdoor work can result in different adverse effects on human health. Health problems decrease performance and work productivity and increase the occurrence of accidents and injuries. Serious health problems can also result in absence from work due to sick leave or hospitalization. At its worst, work in cold conditions could be associated with deaths due to cold-related accidents or a sudden health event. Musculoskeletal complaints, like pain, aches etc. are common in indoor cold work. Breathing cold air while working may lead to respiratory symptoms, which can decrease performance in cold. The symptoms are usually worsened by exercise and ageing, being more common in persons having a respiratory disease. Cardiovascular complaints and related performance decrements could be especially pronounced during work in cold weather and involving physical exercise, especially among those with an underlying cardiovascular disease. The article also reviews the current information related to diabetes, skin disorders and diseases, as well as cold injuries and accidents occurring in cold work. Increasing awareness and identifying workplace- and individual-related cold risks is the first step in proper cold risk management. Following this, the susceptible population groups need customized advice on proper prevention and protection in cold work. PMID:19531906

  15. Human whole body cold adaptation

    PubMed Central

    Daanen, Hein A.M.; Van Marken Lichtenbelt, Wouter D.

    2016-01-01

    ABSTRACT Reviews on whole body human cold adaptation generally do not distinguish between population studies and dedicated acclimation studies, leading to confusing results. Population studies show that indigenous black Africans have reduced shivering thermogenesis in the cold and poor cold induced vasodilation in fingers and toes compared to Caucasians and Inuit. About 40,000 y after humans left Africa, natives in cold terrestrial areas seems to have developed not only behavioral adaptations, but also physiological adaptations to cold. Dedicated studies show that repeated whole body exposure of individual volunteers, mainly Caucasians, to severe cold results in reduced cold sensation but no major physiological changes. Repeated cold water immersion seems to slightly reduce metabolic heat production, while repeated exposure to milder cold conditions shows some increase in metabolic heat production, in particular non-shivering thermogenesis. In conclusion, human cold adaptation in the form of increased metabolism and insulation seems to have occurred during recent evolution in populations, but cannot be developed during a lifetime in cold conditions as encountered in temperate and arctic regions. Therefore, we mainly depend on our behavioral skills to live in and survive the cold. PMID:27227100

  16. Remedies for Common Cold Symptoms

    PubMed Central

    Miller, Penny F.

    1991-01-01

    Individuals suffering from intolerable symptoms of the common cold can now be advised of safe and effective products for symptomatic relief. This article describes and discusses four categories of drugs used to treat the common cold. To simplify the product selection process for family physicians, suggestions are included for possible ingredients for treatments of specific cold symptoms. PMID:21234087

  17. Human whole body cold adaptation.

    PubMed

    Daanen, Hein A M; Van Marken Lichtenbelt, Wouter D

    2016-01-01

    Reviews on whole body human cold adaptation generally do not distinguish between population studies and dedicated acclimation studies, leading to confusing results. Population studies show that indigenous black Africans have reduced shivering thermogenesis in the cold and poor cold induced vasodilation in fingers and toes compared to Caucasians and Inuit. About 40,000 y after humans left Africa, natives in cold terrestrial areas seems to have developed not only behavioral adaptations, but also physiological adaptations to cold. Dedicated studies show that repeated whole body exposure of individual volunteers, mainly Caucasians, to severe cold results in reduced cold sensation but no major physiological changes. Repeated cold water immersion seems to slightly reduce metabolic heat production, while repeated exposure to milder cold conditions shows some increase in metabolic heat production, in particular non-shivering thermogenesis. In conclusion, human cold adaptation in the form of increased metabolism and insulation seems to have occurred during recent evolution in populations, but cannot be developed during a lifetime in cold conditions as encountered in temperate and arctic regions. Therefore, we mainly depend on our behavioral skills to live in and survive the cold. PMID:27227100

  18. Dopamine D3 receptor gene locus: Association with schizophrenia, as well age of onset

    SciTech Connect

    Nimgsonkar, V.L.; Zhang, X.R.; Brar, J.S.

    1994-09-01

    Genetic factors are clearly involved in the etiology of schizophrenia, but their specific nature is unknown. If the genetic etiology is multifactorial or polygenic, the role of specific genes as susceptibility factors can be directly evaluated by examining allelic variation at these loci among cases in comparison with controls. Two studies have independently demonstrated an association of schizophrenia with homozygosity at the dopamine D3 receptor gene (D3RG) locus, using a biallelic polymorphism in the first exon of D3RG. These results are important because D3RG is a favored candidate gene. Three other studies have identified associations among sub-groups of patients, but the majority were negative. The present study involved patients with schizophrenia (DSM-III-R criteria) of Caucasian or African-American ethnicity (n=130). Two groups of controls, matched for ethnicity, were used: adults screened for schizophrenia (n=128) and unselected neonates (n=160). Multivariate analysis revealed an association between allele no. 1 homozygosity and schizophrenia in comparison with adult, but not neonatal controls. The association was most marked among Caucasian patients with a family history of schizophrenia (odds ratio 13.7, C.I. 1.8, 104.3). An association of the D3RG locus with age of onset (AOO) was also noted. The discrepancies in earlier studies may due to variations in control groups, differencies in mean AOO among different cohorts, or ethnic variations in susceptibility attributable to D3RG.

  19. Synthesis, Pharmacological Evaluation and Molecular Modeling Studies of Triazole Containing Dopamine D3 Receptor Ligands

    PubMed Central

    Peng, Xin; Wang, Qi; Mishra, Yogesh; Xu, Jinbin; Reichert, David E.; Malik, Maninder; Taylor, Michelle; Luedtke, Robert R.; Mach, Robert H.

    2015-01-01

    A series of 2-methoxyphenyl piperazine analogues containing a triazole ring were synthesized and their in vitro binding affinities at human dopamine D2 and D3 receptors were evaluated. Compounds 5b, 5c, 5d, and 4g, demonstrate high affinity for dopamine D3 receptors and moderate selectivity for the dopamine D3 versus D2 receptor subtypes. To further examine their potential as therapeutic agents, their intrinsic efficacy at both D2 and D3 receptors was determined using a forskolin-dependent adenylyl cyclase inhibition assay. Affinity at dopamine D4 and serotonin 5-HT1A receptors was also determined. In addition, information from previous molecular modeling studies of the binding of a panel of 163 structurally-related benzamide analogues at dopamine D2 and D3 receptors was applied to this series of compounds. The results of the modeling studies were consistent with our previous experimental data. More importantly, the modeling study results explained why the replacement of the amide linkage with the hetero-aromatic ring leads to a reduction in the affinity of these compounds at D3 receptors. PMID:25556097

  20. 1,25-Dihydroxyvitamin D3 enhances neural stem cell proliferation and oligodendrocyte differentiation.

    PubMed

    Shirazi, Hasti Atashi; Rasouli, Javad; Ciric, Bogoljub; Rostami, Abdolmohamad; Zhang, Guang-Xian

    2015-04-01

    1,25-Dihydroxyvitamin D3 (1,25(OH)2D3) has recently been found to suppress experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS). Although its effect was attributed to an anti-inflammatory mechanism, it is not clear whether this treatment can also directly act on neural cells to promote CNS recovery. The present study investigates the effect of various concentrations of 1,25(OH)2D3 on neural stem cell (NSC) proliferation and their differentiation to oligodendrocytes, the myelinating cells. We have, for the first time, shown that NSCs constitutively express vitamin D receptor (VDR), which can be upregulated by 1,25(OH)2D3. This vitamin significantly enhanced proliferation of NSCs, and enhanced their differentiation into neurons and oligodendrocytes, but not astrocytes. NSCs treated with 1,25(OH)2D3 showed increased expression of NT-3, BDNF, GDNF and CNTF, important neurotrophic factors for neural cell survival and differentiation. Overall, we demonstrated that 1,25(OH)2D3 has a direct effect on NSC proliferation, survival, and neuron/oligodendrocyte differentiation, thus representing a novel mechanism underlying its remyelinating and neuroprotective effect in MS/EAE therapy. PMID:25681066

  1. Photoaffinity labeling of the 1,25-dihydroxyvitamin D-3 receptor.

    PubMed

    Brown, T A; DeLuca, H F

    1991-03-01

    Underivatized 1,25-dihydroxy[26,27-3H]vitamin D-3 was successfully used to photoaffinity label the 1,25-dihydroxyvitamin D-3 receptor. The covalent incorporation of tritium into the receptor protein was induced by ultraviolet irradiation of the receptor-1,25-dihydroxy[26,27-3H]vitamin D-3 complex in crude pig intestinal nuclear extract. The amount of incorporated label increased with increasing time of irradiation and was dependent on light of wavelengths 220-280 nm. Sodium dodecyl sulfate polyacrylamide gel electrophoresis and fluorography were used to demonstrate that label was incorporated primarily into the 1,25-dihydroxyvitamin D-3 receptor. In addition, the label incorporation was eliminated by competition with a 100-fold excess nonradioactive 1,25-dihydroxyvitamin D-3, indicating that the label was specific for the steroid binding site. Since 1,25-(OH)2[26,27-3H]vitamin D-3 is readily available and requires no special precautions for its preparation and handling, it should be a useful photoaffinity label for future studies of the receptor. PMID:1849006

  2. Adequate Vitamin D3 Supplementation During Pregnancy: Decreasing the Prevalence of Asthma and Food Allergies

    PubMed Central

    Finkel, Jonathan; Cira, Courtney; Mazzella, Leanne; Bartyzel, Jim; Ramanna, Annisce; Strimel, Kayla; Waturuocha, Amara; Musser, Nathan; Burress, James; Brammer, Sarah; Wetzel, Robert; Horzempa, Joseph

    2016-01-01

    Vitamin D is a secosterol that is naturally synthesized in the skin upon contact with ultraviolet rays. This vitamin can also be acquired from dietary and nutritional supplements. The active form, vitamin D3, is primarily responsible for calcium homeostasis and bone health. However, many recent studies have associated low levels of vitamin D3 with asthma and food allergies. In this review, we discuss literature to explore the potential that vitamin D3 deficiency may be contributing toward the development of asthma and food allergies. These studies indicate that mothers who supplement with doses of vitamin D3 recommended for daily consumption (400 IU) by the United States Food and Drug Administration is not enough to deliver adequate levels to breastfed infants. Because sufficient vitamin D3 serum levels correlate with a low incidence of asthma and food allergies, high dose vitamin D3 supplementation (4000 IU) by pregnant and breastfeeding women may limit the development of asthma and food allergies in newborns. PMID:27213185

  3. The vitamin D3 metabolite-type activity of Solanum malacoxylon.

    PubMed

    Basudde, C D; Humphreys, D J

    1976-01-01

    1. Administration of an aqueous extract of the dried leaves of Solanum malacoxylon (DLSM) to rats causes a rapid hyperphosphataemia and a decrease in plasma alkaline phosphatase activity; the two effects are typical of 1,25(OH)2D3, the hormonally active metabolite of vitamin D3. 2. DLSM, like both vitamin D3 and parathyroid hormone, increases plasma calcium and citrate levels in rats. The effect of DLSM in influencing plasma citrate, and the role of this important metabolite in mineral metabolism is discussed. 3. A decrease of plasma magnesium levels occurs in rats following treatment with DLSM. This decrease, which is associated with a renal loss of this cation, is remarkably similar to that produced by hypervitaminosis D3. 4. Prolonged administration of DLSM to vitamin D deficient rats causes a polyuria, hypercalciuria, hyperphosphaturia, hypermagnesuria, an increase in urinary total hydroxyproline, an increase in plasma total hexosamines, and a corresponding decrease in the bone total hexosamines. These effects, some of which can also be produced by hyperparathyroidism, or following the administration of parathyroid extract (PTE), large doses of vitamin D3, or 1,25(OH)2D3, suggest that DLSM, like the latter compounds, is capable of causing bone mineral mobilization, and the dissolution of bone organic matrix. PMID:212224

  4. Parkinson's disease treatment may cause impulse-control disorder via dopamine D3 receptors.

    PubMed

    Seeman, Philip

    2015-04-01

    In treating Parkinson's disease with dopaminergic agonists, such as pramipexole, ropinirole, pergolide, rotigotine, apomorphine, or bromocriptine, it has been observed that a significant number of patients develop impulse-control disorders, such as compulsive shopping, pathological gambling, or hypersexuality. Because the dopamine agonists have high affinities for the dopamine D2 and D3 receptors, the drug dissociation constants of these drugs at the functional high-affinity states of these receptors, namely D2High and D3High, were compared. The data show that, compared to the other dopamine agonist drugs, pramipexole has a relatively high selectivity for the dopamine D3 receptor, as compared to D2, suggesting that the D3 receptor may be a primary target for pramipexole. There is a trend showing that the proportion of impulse-control disorders is related to the selectivity for D3 receptors over D2 receptors, with pramipexole having the highest association with, or frequency of, impulse-control disorders. While the number of studies are limited, the proportion of patients with impulse-control disorder in Parkinson patients treated with an add-on agonist were 32% for pramipexole, 25% for ropinirole, 16% for pergolide, 22% for rotigotine, 10% for apomorphine, and 6.8% for bromocriptine. Clinically, temporary replacement of pramipexole by bromocriptine may provide relief or reversal of the impulsive behavior associated with selective D3 stimulation by either pramipexole or ropinirole, while maintaining D2 stimulation needed for the anti-Parkinson action. PMID:25645960

  5. When blood runs cold: cold agglutinins and cardiac surgery.

    PubMed

    Findlater, Rhonda R; Schnell-Hoehn, Karen N

    2011-01-01

    Cold agglutinins are particular cold-reactive antibodies that react with red blood cells when the blood temperature drops below normal body temperature causing increased blood viscosity and red blood cell clumping. Most individuals with cold agglutinins are not aware of their presence, as these antibodies have little effect on daily living, often necessitating no treatment. However, when those with cold agglutinins are exposed to hypothermic situations or undergo procedures such as cardiopulmonary bypass with hypothermia during cardiac surgery, lethal complications of hemolysis, microvascular occlusion and organ failure can occur. By identifying those suspected of possessing cold agglutinins through a comprehensive nursing assessment and patient history, cold agglutinin screening can be performed prior to surgery to determine a diagnosis of cold agglutinin disease. With a confirmed diagnosis of cold agglutinin disease, the plan of care can be focused on measures to maintain the patient's blood temperature above the thermal amplitude throughout their hospitalization including the use of normothermic cardiopulmonary bypass with warm myocardial preservation techniques to prevent these fatal complications. Using a case report approach, the authors review the mechanism, clinical manifestations, detection and nursing management of a patient with cold agglutinins undergoing scheduled cardiac surgery. Cold agglutinin disease is rare. However, the risk to patients warrants an increased awareness of cold agglutinins and screening for those who are suspected of carrying these antibodies. PMID:21630629

  6. Biocompatibility evaluation of surface-treated AISI 316L austenitic stainless steel in human cell cultures.

    PubMed

    Martinesi, M; Bruni, S; Stio, M; Treves, C; Bacci, T; Borgioli, F

    2007-01-01

    The effects of AISI 316L austenitic stainless steel, tested in untreated state or subjected to glow-discharge nitriding (at 10 or 20 hPa) and nitriding + post-oxidizing treatments, on human umbilical vein endothelial cells (HUVEC) and on peripheral blood mononuclear cells (PBMC) were evaluated. All the treated samples showed a better corrosion resistance in PBS and higher surface hardness in comparison with the untreated alloy. In HUVEC put in contact for 72 h with the sample types, proliferation and apoptosis decreased and increased, respectively, in the presence of the nitrided + post-oxidized samples, while only slight differences in cytokine (TNF-alpha, IL-6, and TGF-beta1) release were registered. Intercellular adhesion molecule-1 (ICAM-1) increased in HUVEC incubated with all the treated samples, while vascular cell adhesion molecule-1 (VCAM-1) and E-selectin increased in the presence of all the sample types. PBMC incubated for 48 h with the samples showed a decrease in proliferation and an increase in apoptosis in the presence of the untreated samples and the nitrided + post-oxidized ones. All the sample types induced a remarkable increase in TNF-alpha and IL-6 release in PBMC culture medium, while only the untreated sample and the nitrided at 10 hPa induced an increase in ICAM-1 expression. In HUVEC cocultured with PBMC, previously put in contact with the treated AISI 316L samples, increased levels of ICAM-1 were detected. In HUVEC coincubated with the culture medium of PBMC, previously put in contact with the samples under study, a noteworthy increase in ICAM-1, VCAM-1, and E-selectin levels was always registered, with the exception of VCAM-1, which was not affected by the untreated sample. In conclusion, even if the treated samples do not show a marked increase in biocompatibility in comparison with the untreated alloy, their higher corrosion resistance may suggest a better performance as the contact with physiological environment becomes longer. PMID

  7. Fatigue crack growth behavior and overload effect of AISI 304 stainless steel in different atmospheres

    NASA Astrophysics Data System (ADS)

    Kelestemur, Mehmet Halidun

    1998-12-01

    AISI 304 stainless steel shows strain induced martensitic transformation at the crack tip. Such transformation may have effects on crack closure during fatigue crack propagation. Due to importance of AISI 304 in structural applications, the fatigue crack propagation and martensitic transformation in this material have to be investigated thoroughly. Fatigue crack growth behavior, overload retardation and characterization of martensitic transformation at the crack tip upon fatigue loading were investigated in 304 stainless steel at three different atmospheres, namely dry argon, moist air (75% relative humidity) and hydrogen. Comparison in various atmospheres showed that moist air did not influence that fatigue crack growth rate. However, in hydrogen atmosphere the material did not show threshold behavior and the crack growth rate was considerably higher. It was found that roughness-induced crack closure was the primary mechanism in the threshold region. Fractographic pictures taken by SEM and direct observation of crack profile showed that crack deflection and branching occurred during the fatigue crack propagation and plasticity-induced crack closure was not the primary closure mechanism. The influence of fatigue crack propagation on the rate and size of martensitic transformation at the crack tip was investigated. The overload retardation of the material was lower at hydrogen atmosphere. This low degree of retardation was explained by hydrogen embrittlement mechanism. Fractographic observations show striations at the overload zone in argon atmosphere indicating ductile fracture. In hydrogen atmosphere, overload area shows secondary cracks which represent brittle fracture. Crack closure measurements and modified Paris law did not show evidence for different retardation mechanisms at different atmospheres. It is found that primary retardation mechanisms were crack deflection, crack blunting and roughness-induced crack closure after application of overload(s). An

  8. Radial cold trap

    DOEpatents

    Grundy, Brian R.

    1981-01-01

    The radial cold trap comprises a housing having a plurality of mesh bands disposed therein. The mesh bands comprise concentrically arranged bands of mesh with the mesh specific surface area of each band increasing from the outermost mesh band to the innermost mesh band. An inlet nozzle is attached to the outside section of the housing while an outlet nozzle is attached to the inner portion of the housing so as to be concentrically connected to the innermost mesh band. An inlet baffle having orifices therein may be disposed around the outermost mesh band and within the housing for directing the flow of the fluid from the inlet nozzle to the outermost mesh band in a uniform manner. The flow of fluid passes through each consecutive mesh band and into the outlet nozzle. The circular pattern of the symmetrically arranged mesh packing allows for better utilization of the entire cold trap volume.

  9. Radial cold trap

    DOEpatents

    Grundy, B.R.

    1981-09-29

    The radial cold trap comprises a housing having a plurality of mesh bands disposed therein. The mesh bands comprise concentrically arranged bands of mesh with the mesh specific surface area of each band increasing from the outermost mesh band to the innermost mesh band. An inlet nozzle is attached to the outside section of the housing while an outlet nozzle is attached to the inner portion of the housing so as to be concentrically connected to the innermost mesh band. An inlet baffle having orifices therein may be disposed around the outermost mesh band and within the housing for directing the flow of the fluid from the inlet nozzle to the outermost mesh band in a uniform manner. The flow of fluid passes through each consecutive mesh band and into the outlet nozzle. The circular pattern of the symmetrically arranged mesh packing allows for better utilization of the entire cold trap volume. 2 figs.

  10. Evolution of chemical bonding and electron density rearrangements during D(3h) → D(3d) reaction in monolayered TiS2: a QTAIM and ELF study.

    PubMed

    Ryzhikov, Maxim R; Slepkov, Vladimir A; Kozlova, Svetlana G; Gabuda, Svyatoslav P

    2014-08-15

    Monolayered titanium disulfide TiS2, a prospective nanoelectronic material, was previously shown to be subject to an exothermic solid-state D3h -D3d reaction that proceeds via a newly discovered transition state. Here, we study the reaction in detail using topological methods of quantum chemistry (quantum theory of atoms in molecules and electron localization function analysis) and show how electron density and chemical bonding between the atoms change in the course of the reaction. The reaction is shown to undergo a series of topological catastrophes, associated with elementary chemical events such as break and formation of bonds (including the unexpected formation of S-S bonding between sulfur layers), and rearrangement of electron density of outer valence and core shells. PMID:24943852

  11. Cold nuclear fusion

    SciTech Connect

    Tsyganov, E. N.

    2012-02-15

    Recent accelerator experiments on fusion of various elements have clearly demonstrated that the effective cross-sections of these reactions depend on what material the target particle is placed in. In these experiments, there was a significant increase in the probability of interaction when target nuclei are imbedded in a conducting crystal or are a part of it. These experiments open a new perspective on the problem of so-called cold nuclear fusion.

  12. Clumpy cold dark matter

    NASA Technical Reports Server (NTRS)

    Silk, Joseph; Stebbins, Albert

    1993-01-01

    A study is conducted of cold dark matter (CDM) models in which clumpiness will inhere, using cosmic strings and textures suited to galaxy formation. CDM clumps of 10 million solar mass/cu pc density are generated at about z(eq) redshift, with a sizable fraction surviving. Observable implications encompass dark matter cores in globular clusters and in galactic nuclei. Results from terrestrial dark matter detection experiments may be affected by clumpiness in the Galactic halo.

  13. Active vitamin D3, 1,25-(OH)2D3, protects against macrovasculopathy in a rat model of type 2 diabetes mellitus.

    PubMed

    Ma, R; Deng, X L; Du, G L; Li, C; Xiao, S; Aibibai, Y; Zhu, J

    2016-01-01

    To investigate the protective effect of the active form of vitamin D3, 1,25-(OH)2D3, on macrovasculopathy in rats with type 2 diabetes mellitus (T2DM), 8-week-old male Sprague-Dawley rats were randomly divided into control group, T2DM group, and treatment group. The T2DM model was established after 6 weeks by administering an intraperitoneal injection of streptozotocin (30 mg/kg). 1,25-(OH)2D3 was administered by gavage to rats in the treatment group, and an equal volume of peanut oil was administered to rats in the T2DM group. Fasting plasma glucose (FPG), triglyceride (TG), total cholesterol (TC), high-density lipoprotein (HDL-C) and low-density lipoprotein (LDL-C) cholesterols were measured in all rats. The morphology of the thoracic aorta was examined, and the expression of tumor necrosis factor alpha (TNF-α), endothelin (ET), endothelial nitric oxide synthase (eNOS), CD54, and CD106 in the thoracic aorta was determined by immunohistochemistry. The expression of FPG, TG, TC, and LDL-C in rats from the T2DM and treatment groups was significantly elevated compared with rats from the control group (P < 0.05). Compared with that in control group, the expression of TNF-α, ET, eNOS, and CD106 was significantly upregulated in the T2DM group and the treatment group, while the expression of CD54 was increased only in the T2DM group (P < 0.05). Moreover, the levels of TNF-α, CD54, and CD106 in rats from the treatment group were lower than those in the T2DM group (P < 0.05). These data suggest that 1,25-(OH)2D3 may protect the macrovessels from injury in T2DM rats by inhibiting the expression of TNF-α, CD54, and CD106. PMID:27323139

  14. Cold Stowage Flight Systems

    NASA Technical Reports Server (NTRS)

    Campana, Sharon

    2010-01-01

    The International Space Station (ISS) provides a test bed for researchers to perform science experiments in a variety of fields, including human research, life sciences, and space medicine. Many of the experiments being conducted today require science samples to be stored and transported in a temperature controlled environment. NASA provides several systems which aide researchers in preserving their science. On orbit systems provided by NASA include the Minus Eighty Laboratory freezer for ISS (MELFI), Microgravity Experiment Research Locker Incubator (MERLIN), and Glacier. These freezers use different technologies to provide rapid cooling and cold stowage at different temperature levels on board ISS. Systems available to researchers during transportation to and from ISS are MERLIN, Glacier, and Coldbag. Coldbag is a passive cold stowage system that uses phase change materials. Details of these current technologies will be provided along with operational experience gained to date. With shuttle retirement looming, NASA has protected the capability to provide a temperature controlled environment during transportation to and from the ISS with the use of Glacier and Coldbags, which are compatible with future commercial vehicles including SpaceX's Dragon Capsule, and Orbital s Cygnus vehicle. This paper will discuss the capability of the current cold stowage hardware and how it may continue to support NASA s mission on ISS and in future exploration missions.

  15. Cold Stowage Flight Systems

    NASA Technical Reports Server (NTRS)

    Campana, Sharon E.; Melendez, David T.

    2011-01-01

    The International Space Station (ISS) provides a test bed for researchers to perform science experiments in a variety of fields, including human research, life sciences, and space medicine. Many of the experiments being conducted today require science samples to be stored and transported in a temperature controlled environment. NASA provides several systems which aid researchers in preserving their science. On orbit systems provided by NASA include the Minus Eighty Laboratory freezer for ISS (MELFI), Microgravity Experiment Research Locker Incubator (MERLIN), and Glacier. These freezers use different technologies to provide rapid cooling and cold stowage at different temperature levels on board ISS. Systems available to researchers during transportation to and from ISS are MERLIN, Glacier, and Coldbag. Coldbag is a passive cold stowage system that uses phase change materials to maintain temperature. Details of these current technologies are provided along with operational experience gained to date. This paper discusses the capability of the current cold stowage hardware and how it may continue to support NASA s mission on ISS and in future exploration missions.

  16. Comparative effect of 25(OH)D3 and 1,25(OH)2D3 on Th17 cell differentiation.

    PubMed

    Fawaz, Lama; Mrad, May F; Kazan, Jalal M; Sayegh, Souraya; Akika, Reem; Khoury, Samia J

    2016-05-01

    Vitamin D is a secosteroid hormone that plays an important regulatory role in calcium homeostasis and bone metabolism. Immune cells can both produce and respond to 1,25(OH)2D3. CD4+ T cells from vitamin D receptor (VDR) KO mice produce higher levels of IFN-γ and IL-17 than their wild type counterparts, and play a crucial role in the pathogenesis of autoimmune diseases (AID). We are particularly interested in studying the effect of vitamin D on pathogenic Th17 cells in humans. We investigated the in vitro effect of 1,25(OH)2D3 and 25(OH)D3 on the differentiation and cytokine production of primary CD4+ T cells from normal donors, and cultured in Th17 polarizing conditions. Both forms of vitamin D reduced the expression of pathogenic Th17 markers and their secretion of pro-inflammatory cytokines (IL-17A, IFN-γ). Furthermore, both vitamin D forms induced an expansion of CD25hi cells and upregulated their expression of CTLA-4 and Foxp3 regulatory markers. PMID:27041081

  17. Regioselective synthesis of isotopically labeled Δ9-tetrahydrocannabinolic acid A (THCA-A-D3) by reaction of Δ9-tetrahydrocannabinol-D3 with magnesium methyl carbonate.

    PubMed

    Roth, Nadine; Wohlfarth, Ariane; Müller, Michael; Auwärter, Volker

    2012-10-10

    For the reliable quantification of Δ9-tetrahydrocannabinolic acid A (THCA-A), the biogenetic precursor of Δ9-tetrahydrocannabinol (THC), in biological matrices by LC-MS/MS and GC-MS(/MS), an isotopically labeled internal standard was synthesized starting from Δ9-tetrahydrocannabinol-D(3) (THC-D(3)). Synthesis strategy was based on a method reported by Mechoulam et al. in 1969 using magnesium methyl carbonate (MMC) as carboxylation reagent for the synthesis of cannabinoid acids. Preliminary experiments with THC to optimize yield of the product (THCA-A) resulted in the synthesis of the positional isomer tetrahydrocannabinolic acid B (THCA-B) as a byproduct. Using the optimized conditions for the desired isomer, THCA-A-D(3) was prepared and isolated with a yield of approx. 10% after two synthesis cycles. Isotope purity was estimated to be >99% by relative abundance of the molecular ions. The synthesized compound proved to be suitable as an internal standard for quantification of THCA-A in serum and hair samples of cannabis consumers. PMID:22921834

  18. 1,25(OH)2D3 dependent overt hyperactivity phenotype in klotho-hypomorphic mice

    PubMed Central

    Leibrock, Christina B.; Voelkl, Jakob; Kuro-o, Makoto; Lang, Florian; Lang, Undine E

    2016-01-01

    Klotho, a protein mainly expressed in kidney and cerebral choroid plexus, is a powerful regulator of 1,25(OH)2D3 formation. Klotho-deficient mice (kl/kl) suffer from excessive plasma 1,25(OH)2D3-, Ca2+- and phosphate-concentrations, leading to severe soft tissue calcification and accelerated aging. NH4Cl treatment prevents tissue calcification and premature ageing without affecting 1,25(OH)2D3-formation. The present study explored the impact of excessive 1,25(OH)2D3 formation in NH4Cl-treated kl/kl-mice on behavior. To this end kl/kl-mice and wild-type mice were treated with NH4Cl and either control diet or vitamin D deficient diet (LVD). As a result, plasma 1,25(OH)2D3-, Ca2+- and phosphate-concentrations were significantly higher in untreated and in NH4Cl-treated kl/kl-mice than in wild-type mice, a difference abrogated by LVD. In each, open field, dark-light box, and O-maze NH4Cl-treated kl/kl-mice showed significantly higher exploratory behavior than untreated wild-type mice, a difference abrogated by LVD. The time of floating in the forced swimming test was significantly shorter in NH4Cl treated kl/kl-mice compared to untreated wild-type mice and to kl/kl-mice on LVD. In wild-type animals, NH4Cl treatment did not significantly alter 1,25(OH)2D3, calcium and phosphate concentrations or exploratory behavior. In conclusion, the excessive 1,25(OH)2D3 formation in klotho-hypomorphic mice has a profound effect on murine behavior. PMID:27109615

  19. Vitamin D3 inhibits TNFα-induced latent HIV reactivation in J-LAT cells.

    PubMed

    Nunnari, G; Fagone, P; Lazzara, F; Longo, A; Cambria, D; Di Stefano, G; Palumbo, M; Malaguarnera, L; Di Rosa, Michelino

    2016-07-01

    1,25-Dihydroxyvitamin D3 (1,25(OH)2D3) is known to suppress NF-kB activity by interfering with its pathways. The aim of this study was to investigate the ability of 1,25(OH)2D3 in reducing the reactivation of the HIV virus J-LAT cells, an established model of latently infected cells, which were treated with TNFalpha (100 ng/ml) for 2 h with or without 24 h 1,25(OH)2D3 (100 nM) pretreatment. Reactivation of HIV RNA in J-LAT was evaluated in terms of green fluorescent protein (GFP) expression. The same experimental setting was repeated on T cells from HIV-infected patients. Treatment with TNFalpha was associated with a 16 % increase in GFP+ cells and a five-fold increase in unspliced HIV RNA expression (p < 0.04). Pretreatment of J-LAT cells with 1,25(OH)2D3 for 24 h followed by TNFalpha (100 ng/ml) for 2 h reduced the percentage of GFP+ cells by 8 %; moreover, a 2.4-fold decrease in unspliced HIV RNA expression was observed (p < 0.002). In T cells from patients, treatment with TNFalpha significantly increased unspliced HIV RNA expression (sixfold increase, p < 0.02), whereas prestimulation with 1,25(OH)2D3 reduced its expression (2.5-fold decrease, p < 0.02) compared to controls.1,25(OH)2D3 is able to reduce the ability of TNFalpha to upregulate the transcription of HIV RNA from latently infected cells. These data provide further understanding of the pathogenic mechanisms regulating viral reactivation from latent reservoirs, along with new insight in viral internalization. PMID:27295094

  20. Retinoic acid and 1,25-dihydroxyvitamin D3 stimulate osteoclast formation by different mechanisms

    SciTech Connect

    Scheven, B.A.; Hamilton, N.J. )

    1990-01-01

    The effects of retinoic acid (RA) and 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) on osteoclast formation were examined in intact fetal long bones of different ages/developmental stages maintained in organ culture using a chemically defined medium with or without the presence of serum. Besides stimulating bone resorption, RA and 1,25-(OH)2D3 increased the number of osteoclasts in 19-day-old fetal rat tibiae. Likewise, these bone-resorbing agents induced and stimulated osteoclast formation in 19- and 18-day-old metatarsal bones which were osteoclast-free at the beginning of the culture. The response to 1,25-(OH)2D3 was greatly enhanced by 10% fetal bovine serum (FBS) irrespective of the developmental stage of the long bone. The response to RA was not. Light microscopic autoradiography after labeling of the cultures with tritiated thymidine showed that both RA and 1,25-(OH)2D3 induced osteoclast differentiation from proliferating and postmitotic precursors. However, neither agent was able to stimulate proliferation of osteoclast progenitor cells in the older bones (19 days). Studies on the formation of osteoclast-like (tartrate-resistant acid phosphatase positive) cells in bone marrow cultures indicated that FBS was a potent inducer of osteoclast-like cell formation. In the presence of FBS, 1,25-(OH)2D3 significantly stimulated this response, but RA did not. The results demonstrate that although both RA and 1,25-(OH)2D3 stimulate osteoclast formation from proliferating and postmitotic precursors in long bones in vitro, they do so by different mechanisms.

  1. Computational Study and Modified Design of Selective Dopamine D3 Receptor Agonists.

    PubMed

    Duan, Xinli; Zhang, Xin; Xu, Binglin; Wang, Fang; Lei, Ming

    2016-07-01

    Dopamine D3 receptor (D3 R) is considered as a potential target for the treatment of nervous system disorders, such as Parkinson's disease. Current research interests primarily focus on the discovery and design of potent D3 agonists. In this work, we selected 40 D3 R agonists as the research system. Comparative molecular field analysis (CoMFA) of three-dimensional quantitative structure-activity relationship (3D-QSAR), structure-selectivity relationship (3D-QSSR), and molecular docking was performed on D3 receptor agonists to obtain the details at atomic level. The results indicated that both the CoMFA model (r(2) = 0.982, q(2) = 0.503, rpred2 = 0.893, SEE  = 0.057, F = 166.308) for structure-activity and (r(2) = 0.876, q(2) = 0.436, rpred2 = 0.828, F = 52.645) for structure-selectivity have good predictive capabilities. Furthermore, docking studies on three compounds binding to D3 receptor were performed to analyze the binding modes and interactions. The results elucidate that agonists formed hydrogen bond and hydrophobic interactions with key residues. Finally, we designed six molecules under the guidance of 3D-QSAR/QSSR models. The activity and selectivity of designed molecules have been improved, and ADMET properties demonstrate they have low probability of hepatotoxicity (<0.5). These results from 3D-QSAR/QSSR and docking studies have great significance for designing novel dopamine D3 selective agonists in the future. PMID:26851125

  2. Spinodal decomposition in AISI 316L stainless steel via high-speed laser remelting

    NASA Astrophysics Data System (ADS)

    Chikarakara, Evans; Naher, Sumsun; Brabazon, Dermot

    2014-05-01

    A 1.5 kW CO2 pulsed laser was used to melt the surface of AISI 316L stainless steel with a view to enhancing the surface properties for engineering applications. A 90 μm laser beam spot size focused onto the surface was used to provide high irradiances (up to 23.56 MW/cm2) with low residence times (as low as 50 μs) in order to induce rapid surface melting and solidification. Variations in microstructure at different points within the laser treated region were investigated. From this processing refined lamellar and nodular microstructures were produced. These sets of unique microstructures were produced within the remelted region when the highest energy densities were selected in conjunction with the lowest residence times. The transformation from the typical austenitic structure to much finer unique lamellar and nodular structures was attributed to the high thermal gradients achieved using these selected laser processing parameters. These structures resulted in unique characteristics including elimination of cracks and a reduction of inclusions within the treated region. Grain structure reorientation between the bulk alloy and laser-treated region occurred due to the induced thermal gradients. This present article reports on microstructure forms resulting from the high-speed laser surface remelting and corresponding underlying kinetics.

  3. Solidification Microstructure of AISI M2 High Speed Steel Manufactured by the Horizontal Continuous Casting Process

    NASA Astrophysics Data System (ADS)

    Zhou, X. F.; Fang, F.; Jiang, J. Q.

    2011-01-01

    In the present work, AISI M2 high speed steel is produced by the horizontal continuous casting process. The difference of solidification microstructure in ingots by mould casting and continuous casting has been examined by means of scanning electron microscope (SEM), electron back-scatter diffraction (EBSD), transmission electron microscope (TEM) and high resolution electron microscope (HREM). The results show that the as-cast structure consists of iron matrix and networks of M2C eutectic carbides, which are greatly refined in the continuous casting ingot compared to the case of ingot by mould casting. Meanwhile, the morphology of M2C eutectic carbides changes from the plate-like shape into the fibrous one. Micro-twining and stacking faults are observed in the plate-like M2C, whereas they are rarely identified in the fibrous M2C. Based on the characteristic of morphology and microstructure, it is expected that the plate-like M2C is a faceted phase while the fibrous M2C is a non-faceted phase.

  4. Effect of welding parameters on the heat-affected zone of AISI409 ferritic stainless steel

    NASA Astrophysics Data System (ADS)

    Ranjbarnodeh, Eslam; Hanke, Stefanie; Weiss, Sabine; Fischer, Alfons

    2012-10-01

    One of the main problems during the welding of ferritic stainless steels is severe grain growth within the heat-affected zone (HAZ). In the present study, the microstructural characteristics of tungsten inert gas (TIG) welded AISI409 ferritic stainless steel were investigated by electron backscattered diffraction (EBSD), and the effects of welding parameters on the grain size, local misorientation, and low-angle grain boundaries were studied. A 3-D finite element model (FEM) was developed to predict the effects of welding parameters on the holding time of the HAZ above the critical temperature of grain growth. It is found that the base metal is not fully recrystallized. During the welding, complete recrystallization is followed by severe grain growth. A decrease in the number of low-angle grain boundaries is observed within the HAZ. FEM results show that the final state of residual strains is caused by competition between welding plastic strains and their release by recrystallization. Still, the decisive factor for grain growth is heat input.

  5. Linking anisotropy with Fe3C distribution in AISI 1045 steel

    NASA Astrophysics Data System (ADS)

    Shen, Ke-chang; Li, Gui-hua; Sun, Yi-min; Wang, Yong-gang; Li, Ying-jie; Cao, Guang-hui; Wang, Wei-min

    2015-12-01

    The anisotropy of the microstructure, thermal expansion behavior, corrosion resistance and magnetic properties of AISI 1045 steel was investigated. The distribution of Fe3C lamellae in the investigation plane parallel to the radial directions of molds was observed to differ from that in the investigation plane perpendicular to the radial directions by transmission electron microscopy. The lattice constants a 0 of α-Fe deduced from the XRD patterns of samples prepared using a sand (S)-mold and cut parallel to the radial direction of the mold (S//) and using a metal (M)-mold and cut parallel to the radial direction (M//), the corrosion resistance measured using an electrochemical workstation, and the magnetic permeability obtained by vibrating sample magnetometry also indicated the existence of anisotropy in the tested samples. The anisotropic change of corrosion potential ( E corr), pitting potential ( E pit) and magnetic permeability ( µ) of the samples was observed to depend on the orientation factor F 200 of α-Fe in the measured samples, which is controlled by the distribution of Fe3C lamellae in the eutectoid structure.

  6. Computational Modeling of Microstructural-Evolution in AISI 1005 Steel During Gas Metal Arc Butt Welding

    NASA Astrophysics Data System (ADS)

    Grujicic, M.; Ramaswami, S.; Snipes, J. S.; Yavari, R.; Arakere, A.; Yen, C.-F.; Cheeseman, B. A.

    2013-05-01

    A fully coupled (two-way), transient, thermal-mechanical finite-element procedure is developed to model conventional gas metal arc welding (GMAW) butt-joining process. Two-way thermal-mechanical coupling is achieved by making the mechanical material model of the workpiece and the weld temperature-dependent and by allowing the potential work of plastic deformation resulting from large thermal gradients to be dissipated in the form of heat. To account for the heat losses from the weld into the surroundings, heat transfer effects associated with natural convection and radiation to the environment and thermal-heat conduction to the adjacent workpiece material are considered. The procedure is next combined with the basic physical-metallurgy concepts and principles and applied to a prototypical (plain) low-carbon steel (AISI 1005) to predict the distribution of various crystalline phases within the as-welded material microstructure in different fusion zone and heat-affected zone locations, under given GMAW-process parameters. The results obtained are compared with available open-literature experimental data to provide validation/verification for the proposed GMAW modeling effort.

  7. Corrosion behavior of ASTM A106 and AISI 316SS in KOH and nickel acetate solutions

    SciTech Connect

    Gonzalez, J.J.; Baron, E.; Saldeho, J.

    1999-11-01

    The present work is concerned with the corrosion behavior of ASTM A106 B grade and AISI 316 stainless steel in the presence of three different environments: a mixture or an emulsion formed by oil-KOH-nickel acetate solution, a KOH (40 wt. %) solution and a nickel acetate (14 wt. %) solution, which are representative fluids used during a PDVSA proprietary process for improving heavy crude oils. Corrosion rate measurements and stress corrosion cracking (SCC) behavior were evaluated through weight loss (in the laboratory and in situ measurements), and mechanical testing (constant load and slow strain rate tests). In the emulsion the corrosion rate was almost undetectable for both steels and the evidence suggested that no SCC had taken place. However, the corrosion rate of the carbon steel in 40wt.% KOH solution at 130 C was 2.8 mm/y, showing the presence of pitting corrosion. On the other hand, the stainless steel showed an undetectable corrosion rate. Though SCC was not observed in any of the materials tested in presence of KOH at both 30 and 130 C, a deterioration in the mechanical properties was found for the high temperature case for carbon steel. During nickel acetate solution tests at 130 C, the A 106 steel showed a relatively high corrosion rate (5.9 mm/y) and the formation of pits. For the stainless steel case, acetate solution had no corrosive effect whatsoever. This last environment offered no SCC susceptibility for any material at both temperatures tested.

  8. Investigation of Low-Cycle Bending Fatigue of AISI 9310 Steel Spur Gears

    NASA Technical Reports Server (NTRS)

    Handschuh, Robert F.; Krantz, Timothy L.; Lerch, Bradley A.; Burke, Christopher S.

    2007-01-01

    An investigation of the low-cycle bending fatigue of spur gears made from AISI 9310 gear steel was completed. Tests were conducted using the single-tooth bending method to achieve crack initiation and propagation. Tests were conducted on spur gears in a fatigue test machine using a dedicated gear test fixture. Test loads were applied at the highest point of single tooth contact. Gear bending stresses for a given testing load were calculated using a linear-elastic finite element model. Test data were accumulated from 1/4 cycle to several thousand cycles depending on the test stress level. The relationship of stress and cycles for crack initiation was found to be semilogarithmic. The relationship of stress and cycles for crack propagation was found to be linear. For the range of loads investigated, the crack propagation phase is related to the level of load being applied. Very high loads have comparable crack initiation and propagation times whereas lower loads can have a much smaller number of cycles for crack propagation cycles as compared to crack initiation.

  9. Investigation of Low-Cycle Bending Fatigue of AISI 9310 Steel Spur Gears

    NASA Technical Reports Server (NTRS)

    Handschuh, Robert F.; Krantz, Timothy L.; Lerch, Bradley A.; Burke, Christopher S.

    2007-01-01

    An investigation of the low-cycle bending fatigue of spur gears made from AISI 9310 gear steel was completed. Tests were conducted using the single-tooth bending method to achieve crack initiation and propagation. Tests were conducted on spur gears in a fatigue test machine using a dedicated gear test fixture. Test loads were applied at the highest point of single tooth contact. Gear bending stresses for a given testing load were calculated using a linear-elastic finite element model. Test data were accumulated from 1/4 cycle to several thousand cycles depending on the test stress level. The relationship of stress and cycles for crack initiation was found to be semi-logarithmic. The relationship of stress and cycles for crack propagation was found to be linear. For the range of loads investigated, the crack propagation phase is related to the level of load being applied. Very high loads have comparable crack initiation and propagation times whereas lower loads can have a much smaller number of cycles for crack propagation cycles as compared to crack initiation.

  10. Effect of two synthetic lubricants on life of AISI 9310 spur gears

    NASA Technical Reports Server (NTRS)

    Townsend, Dennis P.; Shimski, John

    1991-01-01

    Spur-gear fatigue tests were conducted with two lubricants using a single lot of consumable-electrode vacuum-melted (CVM) AISI 9310 spur gears. The gears were case carburized and hardened to Rockwell C60. The gear pitch diameter was 8.89 cm. The lot of gears was divided into two groups, each of which was tested with a different lubricant. The test lubricants can be classified as synthetic polyol-ester-based lubricants. One lubricant was 30 percent more viscous that the other. Both lubricants have similar pressure viscosity coefficients. Test conditions included a bulk gear temperature of 350 K, a maximum Hertz stress of 1.71 GPa at the pitch line, and a speed of 10,000 rpm. The surface fatigue life of gears tested with one lubricant was approximately 2.4 times that for gears tested with the other lubricant. The lubricant with the 30 percent higher viscosity gave a calculated elastohydrodynamic (EHD) film thickness that was 20 percent higher than the other lubricant. This increased EHD film thickness is the most probable reason for the improvement in surface fatigue life of gears tested with this lubricant over gears tested with the less viscous lubricant.

  11. Effect of lubricant extreme-pressure additives on surface fatigue life of AISI 9310 spur gears

    NASA Technical Reports Server (NTRS)

    Scibbe, H. W.; Townsend, D. P.; Aron, P. R.

    1984-01-01

    Surface fatigue tests were conducted with AISI 9310 spur gears using a formulated synthetic tetraester oil (conforming to MIL-L-23699 specifications) as the lubricant containing either sulfur or phosphorus as the EP additive. Four groups of gears were tested. One group of gears tested without an additive in the lubricant acted as the reference oil. In the other three groups either a 0.1 wt % sulfur or phosphorus additive was added to the tetraester oil to enhance gear surface fatigue life. Test conditions included a gear temperature of 334 K (160 F), a maximum Hertz stress of 1.71 GPa (248 000 psi), and a speed of 10,000 rpm. The gears tested with a 0.1 wt % phosphorus additive showed pitting fatigue life 2.6 times the life of gears tested with the reference tetraester based oil. Although fatigue lives of two groups of gears tested with the sulfur additive in the oil showed improvement over the control group gear life, the results, unlike those obtained with the phosphorus oil, were not considered to be statistically significant.

  12. Some Temperature Effects on AISI-304 Nitriding in an Inductively Coupled RF Plasma

    SciTech Connect

    Valencia-Alvarado, R.; Barocio, S. R.; Mercado-Cabrera, A.; Pena-Eguiluz, R.; Munoz-Castro, A. E.; Piedad-Beneitez, A. de la; Rosa-Vazquez, J. de la; Lopez-Callejas, R.; Godoy-Cabrera, O. G.

    2006-12-04

    Some recent results obtained from nitriding AISI 304 stainless steel samples, 1.2 cm in diameter and 0.5 cm thick are reported here in the case of an 85% hydrogen and 15% nitrogen mixture work gas. The process was carried out from 300 to 400 W for (13.56 MHz) inductively coupled plasma within a 60 cm long pyrex glass tube 3.5 cm in diameter where the samples were biased up to -300 V with respect to earth. The resulting hardness appears to be a function of the substrate temperature which varied from 200 deg. C at a 0 V bias to 550 deg. C at -300 V. The plasma density at 400 W reached 3x1010 cm-3 with a 4 eV electron temperature. Prior to nitriding, all the samples were polished with 0.05 {mu}m diamond paste, leading to a 30 nm average roughness (Ra). After nitriding at -300 V, the Ra rose until {approx}400 nm while hardness values of 1500 HV under 300 g loads were measured. X ray diffraction indicates that the extended phase amplitude ({gamma}N), Fe and Cr nitride depends on the substrate temperature.

  13. Carburization behavior of AISI 316LN austenitic stainless steel - Experimental studies and modeling

    NASA Astrophysics Data System (ADS)

    Sudha, C.; Sivai Bharasi, N.; Anand, R.; Shaikh, H.; Dayal, R. K.; Vijayalakshmi, M.

    2010-07-01

    AISI type 316LN austenitic stainless steel was exposed to flowing sodium at 798 K for 16,000 h in the bi-metallic (BIM) sodium loop. A modified surface layer of 10 μm width having a ferrite structure was detected from X-ray diffraction and electron micro probe based analysis. Beneath the modified surface layer a carburized zone of 60 μm width was identified which was found to consist of M 23C 6 carbides. A mathematical model based on finite difference technique was developed to predict the carburization profiles in sodium exposed austenitic stainless steel. In the computation, effect of only chromium on carbon diffusion was considered. Amount of carbon remaining in solution was determined from the solubility parameter. The predicted profile showed a reasonably good match with the experimental profile. Calculations were extended to simulate the thickness of the carburized layer after exposure to sodium for a period of 40 years. Attempt was also made to predict the carburization profiles based on equilibrium calculations using Dictra and Thermocalc which contain both thermodynamic and kinetic databases for the system under consideration.

  14. An Electrochemical Processing Strategy for Improving Tribological Performance of Aisi 316 Stainless Steel Under Grease Lubrication

    NASA Astrophysics Data System (ADS)

    Zou, Jiaojuan; Li, Maolin; Lin, Naiming; Zhang, Xiangyu; Qin, Lin; Tang, Bin

    2014-12-01

    In order to improve the tribological performance of AISI 316 stainless steel (316 SS) under grease lubrication, electrochemical processing was conducted on it to obtain a rough (surface texturing-like) surface by making use of the high sensitivity of austenitic stainless steel to pitting corrosion in Cl--rich environment. Numerous corrosion pits or micro-ditches acted as micro-reservoirs on the obtained surface. While the grease could offer consistent lubrication, and then improve the tribological performance of 316 SS. Tribological behaviors of raw 316 SS and the treated sample were measured using a reciprocating type tribometer sliding against GCr15 steel counterpart under dry and grease lubrication conditions. The results showed that the mass losses of the two samples were in the same order of magnitude, and the raw sample exhibited lower friction coefficient in dry sliding. When the tests were conducted under grease lubrication condition, the friction coefficients and mass losses of the treated sample were far lower than those of the raw 316 SS. The tribological performance of 316 SS under grease lubrication was drastically improved after electrochemical processing.

  15. Effect of superheat on the solidification structures of AISI 310S austenitic stainless steel

    SciTech Connect

    Ozbayraktar, S.; Koursaris, A.

    1996-04-01

    An experimental study was carried out to investigate the evolution of macrostructure and microstructure in AISI 310S stainless steel during solidification. Experimental findings suggested that the macrostructure a/nd the microstructure of the cast material responded differently to variations in casting temperature. As the casting temperature decreased, the macrostructure was refined, as expected, but the microstructure coarsened. A relationship was established between the proportion of equiaxed zone and superheat as follows: pct equiaxed zone = a + b ln (1/{Delta}T), where a and b are constants. The relationship between grain width and superheat could be expressed by the equation: gw = e(c+d/{Delta}T), where c and d are constants determined by the distance from the edge of the ingot. The relationship between primary arm spacing and superheat could be expressed by the equation: {lambda}{sub 1} = p + q ln (1/{Delta}T), where p and q are constants determined by the distance from the edge of the ingot. The parameter grain width ratio has been introduced to describe the relationship between the shape and the nucleation and growth kinetics of the columnar grains.

  16. Characterization of irradiated AISI 316L stainless steel disks removed from the Spallation Neutron Source

    SciTech Connect

    Vevera, Bradley J; Hyres, James W; McClintock, David A; Riemer, Bernie

    2014-01-01

    Irradiated AISI 316L stainless steel disks were removed from the Spallation Neutron Source (SNS) for post-irradiation examination (PIE) to assess mechanical property changes due to radiation damage and erosion of the target vessel. Topics reviewed include high-resolution photography of the disk specimens, cleaning to remove mercury (Hg) residue and surface oxides, profile mapping of cavitation pits using high frequency ultrasonic testing (UT), high-resolution surface replication, and machining of test specimens using wire electrical discharge machining (EDM), tensile testing, Rockwell Superficial hardness testing, Vickers microhardness testing, scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). The effectiveness of the cleaning procedure was evident in the pre- and post-cleaning photography and permitted accurate placement of the test specimens on the disks. Due to the limited amount of material available and the unique geometry of the disks, machine fixturing and test specimen design were critical aspects of this work. Multiple designs were considered and refined during mock-up test runs on unirradiated disks. The techniques used to successfully machine and test the various specimens will be presented along with a summary of important findings from the laboratory examinations.

  17. Prediction of Cutting Forces Using ANNs Approach in Hard Turning of AISI 52100 steel

    SciTech Connect

    Makhfi, Souad; Habak, Malek; Velasco, Raphael; Haddouche, Kamel; Vantomme, Pascal

    2011-05-04

    In this study, artificial neural networks (ANNs) was used to predict cutting forces in the case of machining the hard turning of AISI 52100 bearing steel using cBN cutting tool. Cutting forces evolution is considered as the key factors which affect machining. Predicting cutting forces evolution allows optimizing machining by an adaptation of cutting conditions. In this context, it seems interesting to study the contribution that could have artificial neural networks (ANNs) on the machining forces prediction in both numerical and experiment studies. Feed-forward multi-layer neural networks trained by the error back-propagation (BP) algorithm are used. Levenberg-Marquardt (LM) optimization algorithm was used for finding out weights. The training of the network is carried out with experimental machining data.The input dataset used are cutting speed, feed rate, cutting depth and hardness of the material. The output dataset used are cutting forces (Ft-cutting force, Fa- feed force and Fr- radial force).Results of the neural networks approach, in comparison with experimental data are discussed in last part of this paper.

  18. An experimental investigation of pulsed laser-assisted machining of AISI 52100 steel

    NASA Astrophysics Data System (ADS)

    Panjehpour, Afshin; Soleymani Yazdi, Mohammad R.; Shoja-Razavi, Reza

    2014-11-01

    Grinding and hard turning are widely used for machining of hardened bearing steel parts. Laser-assisted machining (LAM) has emerged as an efficient alternative to grinding and hard turning for hardened steel parts. In most cases, continuous-wave lasers were used as a heat source to cause localized heating prior to material removal by a cutting tool. In this study, an experimental investigation of pulsed laser-assisted machining of AISI 52100 bearing steel was conducted. The effects of process parameters (i.e., laser mean power, pulse frequency, pulse energy, cutting speed and feed rate) on state variables (i.e., material removal temperature, specific cutting energy, surface roughness, microstructure, tool wear and chip formation) were investigated. At laser mean power of 425 W with frequency of 120 Hz and cutting speed of 70 m/min, the benefit of LAM was shown by 25% decrease in specific cutting energy and 18% improvement in surface roughness, as compared to those of the conventional machining. It was shown that at constant laser power, the increase of laser pulse energy causes the rapid increase in tool wear rate. Pulsed laser allowed efficient control of surface temperature and heat penetration in material removal region. Examination of the machined subsurface microstructure and microhardness profiles showed no change under LAM and conventional machining. Continuous chips with more uniform plastic deformation were produced in LAM.

  19. Effect of shot peening on surface fatigue life of carburized and hardened AISI 9310 spur gears

    NASA Technical Reports Server (NTRS)

    Townsend, D. P.; Zaretsky, E. V.

    1982-01-01

    Surface fatigue tests were conducted on two groups of AISI 9310 spur gears. Both groups were manufactured with standard ground tooth surfaces, with the second group subjected to an additional shot peening process on the gear tooth flanks. The gear pitch diameter was 8.89 cm (3.5 in.). Test conditions were a gear temperature of 350 K (170 F), a maximum Hertz stress of 1.71 billion N/sq m (248,000 psi), and a speed of 10,000 rpm. The shot peened gears exhibited pitting fatigue lives 1.6 times the life of standard gears without shot peening. Residual stress measurements and analysis indicate that the longer fatigue life is the result of the higher compressive stress produced by the shot peening. The life for the shot peened gear was calculated to be 1.5 times that for the plain gear by using the measured residual stress difference for the standard and shot peened gears. The measured residual stress for the shot peened gears was much higher than that for the standard gears.

  20. Fe-Based Amorphous Coatings on AISI 4130 Structural Steel for Corrosion Resistance

    NASA Astrophysics Data System (ADS)

    Katakam, Shravana; Santhanakrishnan, S.; Dahotre, Narendra B.

    2012-06-01

    The current study focuses on synthesizing a novel functional coating for corrosion resistance applications, via laser surface alloying. The iron-based (Fe48Cr15Mo14Y2C15B) amorphous precursor powder is used for laser surface alloying on AISI 4130 steel substrate, with a continuous wave ytterbium Nd-YAG fiber laser. The corrosion resistance of the coatings is evaluated for different processing conditions. The microstructural evolution and the response of the microstructure to the corrosive environment is studied using x-ray diffraction, scanning electron microscopy, and transmission electron microscopy. Microstructural studies indicate the presence of face-centered cubic Fe-based dendrites intermixed within an amorphous matrix along with fine crystalline precipitates. The corrosion resistance of the coatings decrease with an increase in laser energy density, which is attributed to the precipitation and growth of chromium carbide. The enhanced corrosion resistance of the coatings processed with low energy density is attributed to the self-healing mechanism of this amorphous system.

  1. Investigations on Surface Milling of Hardened AISI 4140 Steel with Pulse Jet MQL Applicator

    NASA Astrophysics Data System (ADS)

    Bashir, Mahmood Al; Mia, Mozammel; Dhar, Nikhil Ranjan

    2016-06-01

    In this article, an experimental investigation was performed in milling hardened AISI 4140 steel of hardness 40 HRC. The machining was performed in both dry and minimal quantity lubricant (MQL) conditions, as part of neat machining, to make a strong comparison of the undertaken machining environments. The MQL was impinged int the form of pulse jet, by using the specially developed pulse-jet-attachment, to ensure that the cutting fluid can be applied in different timed pulses and quantities at critical zones. The tool wear, cutting force and surface roughness were taken as the quality responses while cutting speed, table feed rate and flow rate of the pulse were considered as influential factors. The depth of cut was kept constant at 1.50 mm because of its less significant effects and the straight oil was adopted as cutting fluid in pulse-jet-MQL. The effects of different factors, on the quality responses, are analyzed using ANOVA. It is observed that MQL applicator system exhibits overall better performance when compared to dry milling by reducing surface roughness, cutting force and prolonging tool life but a flow rate of 150 ml/h has tremendous effects on the responses. This investigation and afterward results are expected to aid the industrial practitioner and researcher to adopt the pulse-MQL in high speed milling to prolong tool life, reduce tool wear, diminish cutting force generation and promote better surface finish.

  2. Microstructure and oxidation behavior of high strength steel AISI 410 implanted with nitrogen ion

    NASA Astrophysics Data System (ADS)

    Bandriyana, Ismoyo, Agus Hadi; Sujitno, Tjipto; Dimyati, A.

    2016-04-01

    Surface treatment by implantation with nitrogen-ion was performed on the commercial feritic high strength steel AISI 410 which is termed for high temperature applications. The aim of this research was focused on the surface modification to improve its high temperature oxidation property in the early stages. Ion implantation was carried out at acceleration energy of 100 KeV and ion current 10 mA for 30, 60 and 90 minutes. The samples were subjected to the high temperature oxidation test by means of thermogravimetry in a magnetic suspension balance (MSB) at 500 °C for 5 hours. The scanning electron microscopy (SEM), X-ray diffraction spectrometry (XRD) and Vickers Hardness measurement were used for sample characterization. The formation of ferro-nitride phase after implantation did not occur, however a thin layer considered to contain nitrogen interstitials was detected. The oxidation of both samples before and after implantation followed parabolic kinetics indicating inward growth of oxide scale characteristically due to diffusion of oxygen anions towards matrix surface. After oxidation test relativelly stable oxide scales were observed. Oxidation rates decreased proportionally with the increasing of implantation time due to the formation of oxide layer which is considered to be effectiv inhibitor for the oxygen diffusion.

  3. Surface modification of AISI H13 tool steel by laser cladding with NiTi powder

    NASA Astrophysics Data System (ADS)

    Norhafzan, B.; Aqida, S. N.; Chikarakara, E.; Brabazon, D.

    2016-04-01

    This paper presents laser cladding of NiTi powder on AISI H13 tool steel surface for surface properties enhancement. The cladding process was conducted using Rofin DC-015 diffusion-cooled CO2 laser system with wavelength of 10.6 µm. NiTi powder was pre-placed on H13 tool steel surface. The laser beam was focused with a spot size of 90 µm on the sample surface. Laser parameters were set to 1515 and 1138 W peak power, 18 and 24 % duty cycle and 2300-3500 Hz laser pulse repetition frequency. Hardness properties of the modified layer were characterized by Wilson Hardness tester. Metallographic study and chemical composition were conducted using field emission scanning electron microscope and energy-dispersive X-ray spectrometer (EDXS) analysis. Results showed that hardness of NiTi clad layer increased three times that of the substrate material. The EDXS analysis detected NiTi phase presence in the modified layer up to 9.8 wt%. The metallographic study shows high metallurgical bonding between substrate and modified layer. These findings are significant to both increased hardness and erosion resistance of high-wear-resistant components and elongating their lifetime.

  4. Structural analysis and intergranular corrosion tests of AISI 316L steel.

    PubMed

    Stonawská, Z; Svoboda, M; Sozańska, M; Krístková, M; Sojka, J; Dagbert, C; Hyspecká, L

    2006-10-01

    Pure AISI 316L steel is investigated after solution heat treatment (1050 degrees C/H(2)O) and structural sensitization (650 degrees C). Two quite different intergranular corrosion tests are used to determine the degree of structural sensitization due to the precipitation of secondary phases along the grain boundaries (mainly the M(23)C(6) and sigma-phase): the oxalic acid etch test and the electrochemical potentio-kinetic reactivation test. Generally, the dissolution of chromium-rich carbides (M(23)C(6)) is provoked by oxalic acid etch tests, whereas the chromium-depleted zones, in the vicinity of chromium-rich carbides (M(23)C(6)), are attacked by electrochemical potentio-kinetic reactivation tests. Both intergranular corrosion tests are used to determine the maximum degree of structural sensitization. Thus structural analysis by carbon replicas reveals the Laves phase, and both the M(23)C(6) and (Cr,Mo)(x)(Fe,Ni)(y) phases. The results of intergranular corrosion tests are related to the findings of the structural analysis. PMID:17100908

  5. Effect of Surface Integrity of Hard Turned AISI 52100 Steel on Fatigue Performance

    SciTech Connect

    Lara-Curzio, Edgar; Watkins, Thomas R; Allard Jr, Lawrence Frederick; Riester, Laura

    2007-01-01

    This paper addresses the relationship between surface integrity and fatigue life of hard turned AISI 52100 steel (60-62 HRC), with grinding as a benchmark. The impact of superfinishing on the fatigue performance of hard turned and ground surfaces is also discussed. Specifically, the surface integrity and fatigue life of the following five distinct surface conditions are examined: hard turned with continuous white layer, hard turned with no white layer, ground, and superfinished hard turned and ground specimens. Surface integrity of the specimens is characterized via surface topography measurement, metallography, residual stress measurements, transmission electron microscopy (TEM), and nano-indentation tests. High cycle tension-tension fatigue tests show that the presence of white layer does not adversely affect fatigue life and that, on average, the hard turned surface performs as well or better than the ground surface. The effect of superfinishing is to exaggerate these differences in performance. The results obtained from this study suggest that the effect of residual stress on fatigue life is more significant than the effect of white layer. For the hard turned surfaces, the fatigue life is found to be directly proportional to both the surface compressive residual stress and the maximum compressive residual stress. Possible explanations for the observed effects are discussed.

  6. The Meta-Lax method of stress reduction in welds. [ASTM A36; AISI 4140

    SciTech Connect

    Smith, S.M.

    1992-07-31

    This study is the second phase of ongoing research into the mechanics and feasibility of using the Meta-Lax method of vibratory stress relief in place of thermal methods of stress relief. The first phase of this research revealed results that were similar to, and even superior to those achieved using thermal methods. The testing here was designed to eliminate the effects of interbead tempering by utilizing single pass bead-on-plate welds only. A metallurgical explanation for the success of the Meta-Lax method was not found. No significant structure or chemical changes were noted when used with ASTM A36 or AISI 4140 materials, and the phenomena noted in phase I was apparently due to interbead tempering. The theory of accelerated aging has been proposed and studies exist which observed dislocation motion as a result of vibratory treatment. It is evident that the vibratory stress relief system does not impart sufficient energy to bring about the magnitude of change seen with thermal methods. however the physical improvement is a reality, and vibratory methods should be evaluated further.

  7. White Layer Formation Due to Phase Transformation to Orthogonal machine of AISI 1045 Annealed Steel

    SciTech Connect

    Han, Sangil; Melkote, Shreyes N; Haluska, Dr. Michael S; Watkins, Thomas R

    2008-01-01

    It is commonly believed that the white layer formed during machining of steels is caused primarily by a thermally induced phase transformation resulting from rapid heating and quenching. As a result, it is often assumed that if the temperature at the tool flank-workpiece interface exceeds the nominal phase transformation temperature for the steel, a white layer forms. However, no attempt has been made to actually measure the temperatures produced at the tool flank-workpiece interface and correlate it with microstructural evidence of phase transformation. This paper aims to address these limitations through suitably designed experiments and analysis. Orthogonal machining tests were performed on AISI 1045 annealed steel at different cutting speeds and tool flank wear. During machining, temperature measurements at the tool flank-workpiece interface were made using an exposed thermocouple technique. Metallographic studies of the machined sub-surface and X-ray diffraction (XRD) measurements were performed to determine the presence and depth of white layer, and the presence of the retained austenite phase in the machined surface layer, respectively. Analysis of the data shows that the white layer can form due to phase transformation at temperatures below the nominal austenitization temperature of the steel. Possible causes of this result are presented.

  8. Nano- and Macro-wear of Bio-carbo-nitrided AISI 8620 Steel Surfaces

    NASA Astrophysics Data System (ADS)

    Arthur, Emmanuel Kwesi; Ampaw, Edward; Zebaze Kana, M. G.; Adetunji, A. R.; Olusunle, S. O. O.; Adewoye, O. O.; Soboyejo, W. O.

    2015-12-01

    This paper presents the results of an experimental study of nano- and macro-scale wear in a carbo-nitrided AISI 8620 steel. Carbo-nitriding is carried out using a novel method that involves the use of dried, cyanide-containing cassava leaves, as sources of carbon and nitrogen. These are used in a pack cementation that is used to diffuse carbon and nitrogen into case layers at intermediate temperatures [673.15 K, 723.15 K, 773.15 K, and 823.15 K (400 °C, 450 °C, 500 °C, and 550 °C)]. Nano- and macro-scale wear properties are studied in the case-hardened surfaces, using a combination of nano-scratch and pin-on-disk experiments. The measured wear volumes (at both nano- and macro-length scales) are shown to increase with decreasing pack cyaniding temperature. The nano- and macro-wear resistances are also shown to be enhanced by the in situ diffusion of carbon and nitrogen from cyanide-containing bio-processed waste. The underlying wear mechanisms are also elucidated via atomic force microscopy and scanning electron microscopy observations of the wear tracks. The implications of the results are discussed for the design of hardened carbo-nitrided steel surfaces with improved wear resistance.

  9. Dopamine D3 receptor inhibits the ubiquitin-specific peptidase 48 to promote NHE3 degradation

    PubMed Central

    Armando, Ines; Villar, Van Anthony M.; Jones, John E.; Lee, Hewang; Wang, Xiaoyan; Asico, Laureano D.; Yu, Peiying; Yang, Jian; Escano, Crisanto S.; Pascua-Crusan, Annabelle M.; Felder, Robin A.; Jose, Pedro A.

    2014-01-01

    The dopamine D3 receptor (D3R) is crucial in the regulation of blood pressure and sodium balance, in that Drd3 gene ablation in mice results in hypertension and failure to excrete a dietary salt load. The mechanism responsible for the renal sodium retention in these mice is largely unknown. We now offer and describe a novel mechanism by which D3R decreases sodium transport in the long term by inhibiting the deubiquitinylating activity of ubiquitin-specific peptidase 48 (USP48), thereby promoting Na+-H+ exchanger (NHE)-3 degradation. We found that stimulation with the D3R-specific agonist PD128907 (1 μM, 30 min) promoted the interaction and colocalization among D3R, NHE3, and USP48; inhibited USP48 activity (−35±6%, vs. vehicle), resulting in increased ubiquitinylated NHE3 (+140±10%); and decreased NHE3 expression (−50±9%) in human renal proximal tubule cells (hRPTCs). USP48 silencing decreased NHE3's half-life (USP48 siRNA t1/2=6.1 h vs. vehicle t1/2=12.9 h), whereas overexpression of USP48 increased NHE3 half-life (t1/2=21.8 h), indicating that USP48 protects NHE3 from degradation via deubiquitinylation. USP48 accounted for ∼30% of the total deubiquitinylating activity in these cells. Extending our studies in vivo, we found that pharmacologic blockade of D3R via the D3R-specific antagonist GR103691 (1 μg/kg/min, 4 d) in C57Bl/6J mice increased renal NHE3 expression (+310±15%, vs. vehicle), whereas an innovative kidney-restricted Usp48 silencing via siRNA (3 μg/d, 7 d) increased ubiquitinylated NHE3 (+250±30%, vs. controls), decreased total NHE3 (−23±2%), and lowered blood pressure (−24±2 mm Hg), compared with that in control mice that received either the vehicle or nonsilencing siRNA. Our data demonstrate a crucial role for the dynamic interaction between D3R and USP48 in the regulation of NHE3 expression and function.—Armando, I., Villar, V. A. M., Jones J. E., Lee, H., Wang, X., Asico L. D., Yu, P., Yang, J., Escano, C. S. Jr., Pascua

  10. The action spectrum for vitamin D3: initial skin reaction and prolonged exposure.

    PubMed

    van Dijk, Arjan; den Outer, Peter; van Kranen, Henk; Slaper, Harry

    2016-07-01

    Vitamin D3 photosynthesis in the skin is formulated as a set of reaction equations, including side-reactions to lumisterol, tachysterol and toxisterols, and the accompanying reverse reactions, isomerisation of previtamin D3 to vitamin D3 and photodegradation of vitamin D3. The solution of this set is given for the stationary irradiance spectrum. The effective action spectrum for the instantaneous vitamin D3 production changes shape as a function of exposure, and therefore, no single action spectrum can be used. We assessed the action spectrum for unexposed skin and for skin that has been exposed to 7.5 Standard Erythemal Doses (SED). We constructed two new estimates: (1) the RIVM action spectrum, based on absorption spectra, quantum yields and skin transmission spectra, and (2) the modified QUT action spectrum, which is adjusted for self-absorption and skin transmission. For previously unexposed skin, the modified QUT action spectrum gives a qualitatively similar, but larger estimate than the RIVM action spectrum. We have not been able to solve the lack of quantitative agreement between the vitamin D production estimates from the three action spectrum estimates (RIVM, modified QUT and CIE). All new action spectra have stronger emphasis on the short wavelengths than the CIE action spectrum. We showed that, for wavelengths larger than 300 nm, the bandwidth that was used in the experiment that formed the basis of the CIE action spectrum, gives a red-shift of about 1 nm. Generally, with the formation of previtamin D3, the return reaction to provitamin D3 limits the production of vitamin D3. After some exposure, the new action spectrum has negative values for the longer wavelengths in the UVB. For the RIVM action spectrum, this happens after 7.5 SED, for the modified QUT action spectrum already after 1.25 SED, and after 7.5 SED the net production rate is largely cancelled. Thus prolonged exposure of previously unexposed skin saturates vitamin D3 formation. For maximum

  11. Tolerance evaluation of overdosed dietary levels of 25-hydroxyvitamin D3 in growing piglets.

    PubMed

    von Rosenberg, S J; Weber, G M; Erhardt, A; Höller, U; Wehr, U A; Rambeck, W A

    2016-04-01

    Forty-eight, cross-bred (GL × LW × P) piglets were used in a 42-day tolerance trial to assess the effects of feeding diets supplemented with vitamin D or increasing levels of 25-hydroxyvitamin D3 (25-OH-D3 ). Six-week-old piglets (24 castrate males, 24 females) were used. Two replicate groups of 6 piglets were randomized by weight and allocated to four dietary treatments. The control group (T1) was supplemented with 50 μg vitamin D3 /kg feed. The experimental groups received 25-OH-D3 at the recommended dose (T2: 50 μg/kg = 1x), at 250 μg/kg (T3: 5x) or at 500 μg/kg (T4: 10x) respectively. Feed intake and daily weight gain were measured weekly, and the animals were examined by a veterinarian daily. After 42 days, body mass, blood, urine, bone and tissue samples were analysed and a pathology examination conducted. Dietary treatments had no significant effect on final body mass or daily weight gain. The 25-OH-D3 plasma concentration in T1 was 17 ± 3 ng/ml (mean ± SD) while the respective values of the experimental groups were significantly increased in T2, T3 and T4. Tissue concentrations of 25-OH-D3 were higher in liver and muscle for T3 and T4 and in skin for T4 than in T1. However, neither gross pathology nor histology, nor blood and urine characteristics, nor bone parameters were affected by dietary treatments. Weight of organs as well as dry matter, ash and calcium content of kidneys remained unaffected by dietary 25-OH-D3 intake. Furthermore, no changes were observed for general indicators of health. The results of this study demonstrated that feeding piglets with 25-OH-D3 at 5 or 10 times the recommended level had no adverse effects on any of the biological parameters measured. It was concluded that 25-OH-D3 can be regarded as a supplement with a very high safety margin when used at the recommended level. PMID:26248819

  12. Impact of Vitamin D3 Dietary Supplement Matrix on Clinical Response

    PubMed Central

    Finnell, John S.; Bhandiwad, Anup; Oberg, Erica; Suhaila, Lena; Bradley, Ryan

    2014-01-01

    Context: As a result of research suggesting increased health risk with low serum 25-hydroxycholecalciferol (25(OH)D), health care providers are measuring it frequently. Providers and patients are faced with treatment choices when low status is identified. Objective: To compare the safety and efficacy of three vitamin D3 dietary supplements with different delivery matrices. Setting and Design: A 12-week, parallel group, single-masked, clinical trial was conducted in Seattle, Washington and Kailua Kona, Hawaii. Sixty-six healthy adults with (25(OH)D) <33 ng/mL were randomly assigned to take one of three D3 supplements, ie, a chewable tablet (TAB), an oil-emulsified drop (DROP), or an encapsulated powder (CAP) at a label-claimed dose of 10,000 IU/day. Actual D3 content was assessed by a third party and the results adjusted based on the actual D3 content administered. Mean change in 25(OH)D/mcg D3 administered; difference in the proportion of D3 insufficient participants (ie, 25(OH)D ≤30 ng/mL) reaching sufficiency (ie, 25(OH)D ≥30 ng/mL); and mean change in serum 1, 25-dihydroxycholecalciferol were measured. Results: In two of the three products tested, the measured vitamin D3 content varied considerably from the label-claimed dose. Differences in 25(OH)D/mcg D3 administered were significantly different between groups (P = .04; n = 55). Pairwise comparisons demonstrated DROP resulted in a greater increase than TAB (P < .05) but not than CAP. TAB was not different from CAP. The proportions reaching sufficiency were: 100% (TAB and CAP) and 80% (DROP) (P = .03 between groups; n = 55). 1, 25-Dihydroxycholecalciferol did not change significantly in any group. Conclusions: Oil-emulsified vitamin D3 supplements resulted in a greater mean change in serum 25(OH)D concentration, but fewer patients reaching vitamin D sufficiency, than chewable or encapsulated supplements. PMID:24684456

  13. Effect of cold working on biocompatibility of Ni-free high nitrogen austenitic stainless steels using Dalton's Lymphoma cell line.

    PubMed

    Talha, Mohd; Kumar, Sanjay; Behera, C K; Sinha, O P

    2014-02-01

    The aims of the present work are to explore the effect of cold working on in-vitro biocompatibility of indigenized low cost Ni-free nitrogen containing austenitic stainless steels (HNSs) and to compare it with conventionally used biomedical grade, i.e. AISI 316L and 316LVM, using Dalton's Lymphoma (DL) cell line. The MTT assay [3-(4,5-dimethythiazol 2-yl)-2,5-diphenyltetrazolium bromide] was performed on DL cell line for cytotoxicity evaluation and cell adhesion test. As a result, it was observed that the HNS had higher cell proliferation and cell growth and it increases by increasing nitrogen content and degree of cold working. The surface wettability of the alloys was also investigated by water contact angle measurements. The value of contact angles was found to decrease with increase in nitrogen content and degree of cold working. This indicates that the hydrophilic character increases with increasing nitrogen content and degree of cold working which further attributed to enhance the surface free energy (SFE) which would be conducive to cell adhesion which in turn increases the cell proliferation. PMID:24411354

  14. Calcitonin and vitamin D3 have high therapeutic potential for improving diabetic mandibular growth

    PubMed Central

    Abbassy, Mona A; Watari, Ippei; Bakry, Ahmed S; Ono, Takashi; Hassan, Ali H

    2016-01-01

    The goal of this study was to assess the effect of the intermittent combination of an antiresorptive agent (calcitonin) and an anabolic agent (vitamin D3) on treating the detrimental effects of Type 1 diabetes mellitus (DM) on mandibular bone formation and growth. Forty 3-week-old male Wistar rats were divided into four groups: the control group (normal rats), the control C+D group (normal rats injected with calcitonin and vitamin D3), the diabetic C+D group (diabetic rats injected with calcitonin and vitamin D3) and the diabetic group (uncontrolled diabetic rats). An experimental DM condition was induced in the male Wistar rats in the diabetic and diabetic C+D groups using a single dose of 60 mg·kg−1 body weight of streptozotocin. Calcitonin and vitamin D3 were simultaneously injected in the rats of the control C+D and diabetic C+D groups. All rats were killed after 4 weeks, and the right mandibles were evaluated by micro-computed tomography and histomorphometric analysis. Diabetic rats showed a significant deterioration in bone quality and bone formation (diabetic group). By contrast, with the injection of calcitonin and vitamin D3, both bone parameters and bone formation significantly improved (diabetic C+D group) (P < 0.05). These findings suggest that these two hormones might potentially improve various bone properties. PMID:27025264

  15. Hypovitaminosis D3, Leukopenia, and Human Serotonin Transporter Polymorphism in Anorexia Nervosa and Bulimia Nervosa

    PubMed Central

    Tasegian, Anna; Curcio, Francesco; Dalla Ragione, Laura; Rossetti, Francesca; Cataldi, Samuela; Codini, Michela; Ambesi-Impiombato, Francesco Saverio; Beccari, Tommaso; Albi, Elisabetta

    2016-01-01

    Vitamin D3 has been described to have different extraskeletal roles by acting as parahormone in obesity, diabetes, cancer, cognitive impairment, and dementia and to have important regulatory functions in innate immunity. There are no studies showing extraskeletal changes associated with hypovitaminosis D3 in eating disorders. Methods. We have analyzed the blood of 18 patients affected by anorexia nervosa and bulimia nervosa collected over a 15-month period. We performed a panel of chemical and clinical analyses: the assay of vitamin D3, the immunoblotting of vitamin D receptor and peroxisome proliferator-activated receptor gamma, and the genotyping of 5-hydroxytryptamine transporter linked polymorphic region. Results. We choose 18 patients with a normal blood test profile such as thyroid hormones, hepatic and renal parameters, triglycerides, proteins, vitamin B12, and folic acid. Among these emerged the case of a woman with long-term anorexia nervosa and the case of a woman with long-term bulimia nervosa both complicated by anxiety and depression, severe hypovitaminosis D3, decrease of vitamin D receptor, leukopenia, and 5-hydroxytryptamine transporter linked polymorphic region short allele. Conclusion. The results induce hypothesising that the severe hypovitaminosis D3 might be responsible for the lack of the inflammatory response and the depressive symptoms in patients with long-term eating disorders. PMID:26903713

  16. Vitamin D3 mediated effects on postprandial leukocyte activation and arterial stiffness in men and women.

    PubMed

    Klop, B; van de Geijn, G-J M; Birnie, E; Njo, T L; Janssen, H W; Jansen, H G; Jukema, J W; Elte, J W F; Castro Cabezas, M

    2014-05-01

    Postprandial inflammation is considered to be pro-atherogenic. Vitamin D can reduce inflammation and arterial stiffness. We hypothesized that vitamin D3 improves postprandial arterial elasticity by the modulation of leukocyte activation. Healthy volunteers underwent two oral fat-loading tests (OFLTs). The augmentation index (AIx) and flow cytometric quantification of leukocyte activation markers were measured. After the first OFLT, 100 000 IU of vitamin D3 was administered and a second OFLT was carried out 7 days later. Six men and six women were included. A favorable reduction in AIx was found after vitamin D3 supplementation (P=0.042) in both genders. After vitamin D3, exclusively in women a reduction in the area under the postprandial curve for monocytes CD11b and CD35 by 10.5% (P=0.016) and 12.5% (P=0.04) and neutrophil CD11b by 17.0% (P=0.014) was observed. In conclusion, vitamin D3 probably increased postprandial arterial elasticity in men and women, but reduced postprandial leukocyte activation exclusively in women. PMID:24619107

  17. Hypovitaminosis D3, Leukopenia, and Human Serotonin Transporter Polymorphism in Anorexia Nervosa and Bulimia Nervosa.

    PubMed

    Tasegian, Anna; Curcio, Francesco; Dalla Ragione, Laura; Rossetti, Francesca; Cataldi, Samuela; Codini, Michela; Ambesi-Impiombato, Francesco Saverio; Beccari, Tommaso; Albi, Elisabetta

    2016-01-01

    Vitamin D3 has been described to have different extraskeletal roles by acting as parahormone in obesity, diabetes, cancer, cognitive impairment, and dementia and to have important regulatory functions in innate immunity. There are no studies showing extraskeletal changes associated with hypovitaminosis D3 in eating disorders. Methods. We have analyzed the blood of 18 patients affected by anorexia nervosa and bulimia nervosa collected over a 15-month period. We performed a panel of chemical and clinical analyses: the assay of vitamin D3, the immunoblotting of vitamin D receptor and peroxisome proliferator-activated receptor gamma, and the genotyping of 5-hydroxytryptamine transporter linked polymorphic region. Results. We choose 18 patients with a normal blood test profile such as thyroid hormones, hepatic and renal parameters, triglycerides, proteins, vitamin B12, and folic acid. Among these emerged the case of a woman with long-term anorexia nervosa and the case of a woman with long-term bulimia nervosa both complicated by anxiety and depression, severe hypovitaminosis D3, decrease of vitamin D receptor, leukopenia, and 5-hydroxytryptamine transporter linked polymorphic region short allele. Conclusion. The results induce hypothesising that the severe hypovitaminosis D3 might be responsible for the lack of the inflammatory response and the depressive symptoms in patients with long-term eating disorders. PMID:26903713

  18. Babesia bovis: biosynthesis and localisation of 12D3 antigen in bovine erythrocytes.

    PubMed

    Harper, G S; Hibbs, A R; East, I J; Waltisbuhl, D J; Jorgensen, W K; Riddles, P W

    1996-11-01

    The 12D3 antigen of Babesia bovis was found to be synthesised rapidly in cultured parasites, and localised to both the apical complex of the merozoite and the cytoplasm of the parasitised erythrocyte. Amino-terminal sequencing suggested that the nascent protein had been processed and differences between the predicted and measured molecular weights suggested post-translational modification. The major proportion of 12D3 appeared in the soluble compartment of the parasitised erythrocytes with a molecular weight consistent with no further processing. A significant proportion of the protein required extraction by sodium carbonate, suggesting association with membranous components. The timing of release of soluble 12D3 was coincident with haemoglobin release and this probably reflects a non-specific lysis of the erythrocyte. Synthesis of recombinant BV12D3 was achieved in baculovirus-infected SF9 insect epithelial cells. The product was of the same molecular weight as the native 12D3 and polyclonal antibodies raised against the recombinant protein reacted with both the recombinant and native forms of the antigen. PMID:9024870

  19. Calcitonin and vitamin D3 have high therapeutic potential for improving diabetic mandibular growth.

    PubMed

    Abbassy, Mona A; Watari, Ippei; Bakry, Ahmed S; Ono, Takashi; Hassan, Ali H

    2016-03-01

    The goal of this study was to assess the effect of the intermittent combination of an antiresorptive agent (calcitonin) and an anabolic agent (vitamin D3) on treating the detrimental effects of Type 1 diabetes mellitus (DM) on mandibular bone formation and growth. Forty 3-week-old male Wistar rats were divided into four groups: the control group (normal rats), the control C+D group (normal rats injected with calcitonin and vitamin D3), the diabetic C+D group (diabetic rats injected with calcitonin and vitamin D3) and the diabetic group (uncontrolled diabetic rats). An experimental DM condition was induced in the male Wistar rats in the diabetic and diabetic C+D groups using a single dose of 60 mg·kg(-1) body weight of streptozotocin. Calcitonin and vitamin D3 were simultaneously injected in the rats of the control C+D and diabetic C+D groups. All rats were killed after 4 weeks, and the right mandibles were evaluated by micro-computed tomography and histomorphometric analysis. Diabetic rats showed a significant deterioration in bone quality and bone formation (diabetic group). By contrast, with the injection of calcitonin and vitamin D3, both bone parameters and bone formation significantly improved (diabetic C+D group) (P < 0.05). These findings suggest that these two hormones might potentially improve various bone properties. PMID:27025264

  20. Resolvin D3 Is Dysregulated in Arthritis and Reduces Arthritic Inflammation.

    PubMed

    Arnardottir, Hildur H; Dalli, Jesmond; Norling, Lucy V; Colas, Romain A; Perretti, Mauro; Serhan, Charles N

    2016-09-15

    Uncontrolled inflammation is a unifying component of many chronic inflammatory diseases, such as arthritis. Resolvins (Rvs) are a new family from the endogenous specialized proresolving mediators (SPMs) that actively stimulate resolution of inflammation. In this study, using lipid mediator metabololipidomics with murine joints we found a temporal regulation of endogenous SPMs during self-resolving inflammatory arthritis. The SPMs present in self-resolving arthritic joints include the D-series Rvs, for example, RvD1, RvD2, RvD3, and RvD4. Of note, RvD3 levels were reduced in inflamed joints from mice with delayed-resolving arthritis when compared with self-resolving inflammatory arthritis. RvD3 was also reduced in serum from rheumatoid arthritis patients compared with healthy controls. RvD3 administration reduced joint leukocytes as well as paw joint eicosanoids, clinical scores, and edema. Taken together, these findings provide evidence for dysregulated endogenous RvD3 levels in inflamed paw joints and its potent actions in reducing murine arthritis. PMID:27534559

  1. 1,25-Dihydroxyvitamin D3 and Development of Tuberculosis in Cattle

    PubMed Central

    Rhodes, S. G.; Terry, L. A.; Hope, J.; Hewinson, R. G.; Vordermeier, H. M.

    2003-01-01

    This report describes the presence and activity of 1,25-dihydroxyvitamin D3 (1,25-D3) in experimental bovine tuberculosis. Animals that went on to develop tuberculous lesions exhibited a rapid transient increase in serum 1,25-D3 within the first 2 weeks following infection with Mycobacterium bovis. 1,25-D3-positive mononuclear cells were later identified in all tuberculous granulomas by immunohistochemical staining of postmortem lymph node tissue. These results suggest a role for 1,25-D3 both at the onset of infection and in the development of the granuloma in these infected animals. Using a monoclonal antibody to the vitamin D receptor (VDR) as a VDR agonist, we confirmed that activation of the vitamin D pathway profoundly depresses antigen-specific, but not mitogenic, bovine peripheral blood T-cell responses (proliferation and gamma interferon production). Investigation of the mechanism of this suppression showed that the VDR antibody modified the expression of CD80 by accessory cells, such that a significant positive correlation between T-cell proliferation and accessory cell CD80 emerged. PMID:14607878

  2. The Isis cold moderators

    SciTech Connect

    Allen, G. M.; Broome, T. A.; Burridge, R. A.; Cragg, D.; Hall, R.; Haynes, D.; Hirst, J.; Hogston, J. R.; Jones, H. H.; Sexton, J.; Wright, P.

    1997-09-01

    ISIS is a pulsed spallation neutron source where neutrons are produced by the interaction of a 160 kW proton beam of energy 800 MeV in a water-cooled Tantalum Target. The fast neutrons produced are thermalized in four moderators: two ambient water, one liquid methane operating at 100K and a liquid hydrogen moderator at 20 K. This paper gives a description of the construction of both cold moderator systems, details of the operating experience and a description of the current development program.

  3. Paroxysmal cold hemoglobinuria.

    PubMed

    Shanbhag, Satish; Spivak, Jerry

    2015-06-01

    Paroxysmal cold hemoglobinuria is a rare cause of autoimmune hemolytic anemia predominantly seen as an acute form in young children after viral illnesses and in a chronic form in some hematological malignancies and tertiary syphilis. It is a complement mediated intravascular hemolytic anemia associated with a biphasic antibody against the P antigen on red cells. The antibody attaches to red cells at colder temperatures and causes red cell lysis when blood recirculates to warmer parts of the body. Treatment is mainly supportive and with red cell transfusion, but immunosuppressive therapy may be effective in severe cases. PMID:26043386

  4. SpreaD3: Interactive Visualization of Spatiotemporal History and Trait Evolutionary Processes.

    PubMed

    Bielejec, Filip; Baele, Guy; Vrancken, Bram; Suchard, Marc A; Rambaut, Andrew; Lemey, Philippe

    2016-08-01

    Model-based phylogenetic reconstructions increasingly consider spatial or phenotypic traits in conjunction with sequence data to study evolutionary processes. Alongside parameter estimation, visualization of ancestral reconstructions represents an integral part of these analyses. Here, we present a complete overhaul of the spatial phylogenetic reconstruction of evolutionary dynamics software, now called SpreaD3 to emphasize the use of data-driven documents, as an analysis and visualization package that primarily complements Bayesian inference in BEAST (http://beast.bio.ed.ac.uk, last accessed 9 May 2016). The integration of JavaScript D3 libraries (www.d3.org, last accessed 9 May 2016) offers novel interactive web-based visualization capacities that are not restricted to spatial traits and extend to any discrete or continuously valued trait for any organism of interest. PMID:27189542

  5. Breakdown of three-dimensional Dirac semimetal state in pressurized C d3A s2

    NASA Astrophysics Data System (ADS)

    Zhang, Shan; Wu, Qi; Schoop, Leslie; Ali, Mazhar N.; Shi, Youguo; Ni, Ni; Gibson, Quinn; Jiang, Shang; Sidorov, Vladimir; Yi, Wei; Guo, Jing; Zhou, Yazhou; Wu, Desheng; Gao, Peiwen; Gu, Dachun; Zhang, Chao; Jiang, Sheng; Yang, Ke; Li, Aiguo; Li, Yanchun; Li, Xiaodong; Liu, Jing; Dai, Xi; Fang, Zhong; Cava, Robert J.; Sun, Liling; Zhao, Zhongxian

    2015-04-01

    We report an observation of a pressure-induced breakdown of the three-dimensional Dirac semimetal (3D-DSM) state in C d3A s2 , evidenced by a series of in situ high-pressure synchrotron x-ray diffraction and single-crystal transport measurements. We find that C d3A s2 undergoes a structural phase transition from a metallic tetragonal phase in space group I 41/a c d to a semiconducting monoclinic phase in space group P 21/c at critical pressure 2.57 GPa; above this pressure, an activation energy gap appears, accompanied by distinct switches in Hall resistivity slope and electron mobility. These changes of crystal symmetry and corresponding transport properties manifest the breakdown of the 3DDSM state in pressurized C d3A s2 .

  6. Visualization of dopamine D3-like receptors in human brain with [125I]epidepride.

    PubMed

    Murray, A M; Ryoo, H; Joyce, J N

    1992-12-01

    In sections of human brain containing the striatum (caudate, nucleus, putamen, nucleus accumbens) the competition for binding of [125I]epidepride by compounds with differing selectivity for dopamine D2 and D3 receptors was examined. Domperidone showed higher affinity for D2-like than D3-like sites whereas 7-OH-DPAT (7-hydroxy-2-(N,N-di-n-propylamino)tetralin) and quinpirole demonstrated the reverse selectivity. The pattern of [125I]epidepride binding in the presence of a high concentration of domperidone was negligible in the dorsal striatum but indicated islands of dense binding to D3-like receptors in the nucleus accumbens and ventral putamen. PMID:1359976

  7. Intestinal absorption of triglyceride and vitamin D3 in aged and young rats

    SciTech Connect

    Holt, P.R.; Dominguez, A.A.

    1981-12-01

    (3H)Trioleyl glycerol (TO) and (14C)vitamin D3 were perfused intraduodenally for 5 hr in aged (19-21 months) and young adult (4-5 months) Sprague-Dawley rats. The rate of intestinal uptake from the gastrointestinal lumen and transport into the body of these lipids were decreased in the aged animals. Since the distribution of TO lipolytic products in the lumen was unchanged, reduced intestinal uptake rate probably occurred at the mucosal membrane. Furthermore, in the aged rats, the rate of transintestinal transport of both trioleyl glycerol and vitamin D3 was impaired. No evidence for impaired mucosal TO reesterification or for accumulation of vitamin D3 metabolites was found, suggesting that intestinal lipid accumulation resulted from a defect in lipoprotein assembly or in discharge from the mucosal cell. Impaired absorption of lipids may contribute to malnutrition and osteopenia of advancing age.

  8. 70 FR 36021 - Food Additives Permitted for Direct Addition to Food for Human Consumption; Vitamin D3

    Federal Register 2010, 2011, 2012, 2013, 2014

    2005-06-22

    ... (68 FR 9000), FDA issued a final rule permitting the safe use of vitamin D 3 as a nutrient supplement... to Food for Human Consumption; Vitamin D 3 AGENCY: Food and Drug Administration, HHS. ACTION: Final... additive regulations authorizing the use of vitamin D 3 as a nutrient supplement in calcium-fortified...

  9. 1,25 Dihydroxyvitamin D3 Inhibits TGFβ1-Mediated Primary Human Cardiac Myofibroblast Activation

    PubMed Central

    Meredith, Anna; Boroomand, Seti; Carthy, Jon; Luo, Zongshu; McManus, Bruce

    2015-01-01

    Aims Epidemiological and interventional studies have suggested a protective role for vitamin D in cardiovascular disease, and basic research has implicated vitamin D as a potential inhibitor of fibrosis in a number of organ systems; yet little is known regarding direct effects of vitamin D on human cardiac cells. Given the critical role of fibrotic responses in end stage cardiac disease, we examined the effect of active vitamin D treatment on fibrotic responses in primary human adult ventricular cardiac fibroblasts (HCF-av), and investigated the relationship between circulating vitamin D (25(OH)D3) and cardiac fibrosis in human myocardial samples. Methods and Results Interstitial cardiac fibrosis in end stage HF was evaluated by image analysis of picrosirius red stained myocardial sections. Serum 25(OH)D3 levels were assayed using mass spectrometry. Commercially available HCF-av were treated with transforming growth factor (TGF)β1 to induce activation, in the presence or absence of active vitamin D (1,25(OH)2D3). Functional responses of fibroblasts were analyzed by in vitro collagen gel contraction assay. 1,25(OH)2D3 treatment significantly inhibited TGFβ1-mediated cell contraction, and confocal imaging demonstrated reduced stress fiber formation in the presence of 1,25(OH)2D3. Treatment with 1,25(OH)2D3 reduced alpha-smooth muscle actin expression to control levels and inhibited SMAD2 phosphorylation. Conclusions Our results demonstrate that active vitamin D can prevent TGFβ1-mediated biochemical and functional pro-fibrotic changes in human primary cardiac fibroblasts. An inverse relationship between vitamin D status and cardiac fibrosis in end stage heart failure was observed. Collectively, our data support an inhibitory role for vitamin D in cardiac fibrosis. PMID:26061181

  10. Vitamin D3 Supplemental Treatment for Mania in Youth with Bipolar Spectrum Disorders

    PubMed Central

    Sikoglu, Elif M.; Navarro, Ana A. Liso; Starr, Debra; Dvir, Yael; Nwosu, Benjamin Udoka; Czerniak, Suzanne M.; Rogan, Ryan C.; Castro, Martha C.; Edden, Richard A. E.; Frazier, Jean A.

    2015-01-01

    Abstract Objective: We aimed to determine the effect of an open-label 8 week Vitamin D3 supplementation on manic symptoms, anterior cingulate cortex (ACC) glutamate, and γ-aminobutyric acid (GABA) in youth exhibiting symptoms of mania; that is, patients with bipolar spectrum disorders (BSD). We hypothesized that an 8 week Vitamin D3 supplementation would improve symptoms of mania, decrease ACC glutamate, and increase ACC GABA in BSD patients. Single time point metabolite levels were also evaluated in typically developing children (TD). Methods: The BSD group included patients not only diagnosed with BD but also those exhibiting bipolar symptomology, including BD not otherwise specified (BD-NOS) and subthreshold mood ratings (Young Mania Rating Scale [YMRS] ≥8 and Clinical Global Impressions - Severity [CGI-S] ≥3). Inclusion criteria were: male or female participants, 6–17 years old. Sixteen youth with BSD exhibiting manic symptoms and 19 TD were included. BSD patients were asked to a take daily dose (2000 IU) of Vitamin D3 (for 8 weeks) as a supplement. Neuroimaging data were acquired in both groups at baseline, and also for the BSD group at the end of 8 week Vitamin D3 supplementation. Results: Baseline ACC GABA/creatine (Cr) was lower in BSD than in TD (F[1,31]=8.91, p=0.007). Following an 8 week Vitamin D3 supplementation, in BSD patients, there was a significant decrease in YMRS scores (t=−3.66, p=0.002, df=15) and Children's Depression Rating Scale (CDRS) scores (t=−2.93, p=0.01, df=15); and a significant increase in ACC GABA (t=3.18, p=0.007, df=14). Conclusions: Following an 8 week open label trial with Vitamin D3, BSD patients exhibited improvement in their mood symptoms in conjunction with their brain neurochemistry. PMID:26091195

  11. Dopamine D3 Receptor Mediates Preadolescent Stress-Induced Adult Psychiatric Disorders

    PubMed Central

    Seo, Joon H.; Kuzhikandathil, Eldo V.

    2015-01-01

    Several studies have shown that repeated stressful experiences during childhood increases the likelihood of developing depression- and anxiety-related disorders in adulthood; however, the underlying mechanisms are not well understood. We subjected drd3-EGFP and drd3-null mice to daily, two hour restraint stress episodes over a five day period during preadolescence (postnatal day 35 to 39), followed by social isolation. When these mice reached adulthood (post-natal day > 90), we assessed locomotor behavior in a novel environment, and assessed depression-related behavior in the Porsolt Forced Swim test. We also measured the expression and function of dopamine D3 receptor in limbic brain areas such as hippocampus, nucleus accumbens and amygdala in control and stressed drd3-EGFP mice in adulthood. Adult male mice subjected to restraint stress during preadolescence exhibited both anxiety- and depression-related behaviors; however, adult female mice subjected to preadolescent restraint stress exhibited only depression-related behaviors. The development of preadolescent stress-derived psychiatric disorders was blocked by D3 receptor selective antagonist, SB 277011-A, and absent in D3 receptor null mice. Adult male mice that experienced stress during preadolescence exhibited a loss of D3 receptor expression and function in the amygdala but not in hippocampus or nucleus accumbens. In contrast, adult female mice that experienced preadolescent stress exhibited increased D3 receptor expression in the nucleus accumbens but not in amygdala or hippocampus. Our results suggest that the dopamine D3 receptor is centrally involved in the etiology of adult anxiety- and depression-related behaviors that arise from repeated stressful experiences during childhood. PMID:26619275

  12. RUNX2 Mutation Impairs 1α,25-Dihydroxyvitamin D3 mediated Osteoclastogenesis in Dental Follicle Cells

    PubMed Central

    Wang, X. Z.; Sun, X. Y.; Zhang, C. Y.; Yang, X.; Yan, W. J.; Ge, L. H.; Zheng, S. G.

    2016-01-01

    Cleidocranial dysplasia (CCD), a skeletal disorder characterized by delayed permanent tooth eruption and other dental abnormalities, is caused by heterozygous RUNX2 mutations. As an osteoblast-specific transcription factor, RUNX2 plays a role in bone remodeling, tooth formation and tooth eruption. To investigate the crosstalk between RUNX2 and 1α,25-dihydroxyvitamin D3 (1α,25-(OH)2D3) in human dental follicle cells (hDFCs) during osteoclast formation, we established a co-culture system of hDFCs from CCD patient and healthy donors with peripheral blood mononuclear cells (PBMCs). Expression of the osteoclast-associated genes and the number of TRAP+ cells were reduced in CCD hDFCs, indicating its suppressed osteoclast-inductive ability, which was reflected by the downregulated RANKL/OPG ratio. In addition, 1α,25-(OH)2D3-stimulation elevated the expression of osteoclast-related genes, as well as RANKL mRNA levels and RANKL/OPG ratios in control hDFCs. Conversely, RUNX2 mutation abolished this 1α,25-(OH)2D3-induced RANKL gene activation and osteoclast formation in CCD hDFCs. Therefore, RUNX2 haploinsufficiency impairs dental follicle-induced osteoclast formation capacity through RANKL/OPG signaling, which may be partially responsible for delayed permanent tooth eruption in CCD patients. Furthermore, this abnormality was not rescued by 1α,25-(OH)2D3 application because 1α,25-(OH)2D3-induced RANKL activation in hDFCs is mediated principally via the RUNX2-dependent pathway. PMID:27068678

  13. The role of receptor topology in the vitamin D3 uptake and Ca(2+) response systems.

    PubMed

    Morrill, Gene A; Kostellow, Adele B; Gupta, Raj K

    2016-09-01

    The steroid hormone, vitamin D3, regulates gene transcription via at least two receptors and initiates putative rapid response systems at the plasma membrane. The vitamin D receptor (VDR) binds vitamin D3 and a second receptor, importin-4, imports the VDR-vitamin D3 complex into the nucleus via nuclear pores. Here we present evidence that the Homo sapiens VDR homodimer contains two transmembrane (TM) helices ((327)E - D(342)), two TM "half-helix" ((264)K N(276)), one or more large channels, and 16 cholesterol binding (CRAC/CARC) domains. The importin-4 monomer exhibits 3 pore-lining regions ((226)E - L(251); (768)V - G(783); (876)S - A(891)) and 16 CRAC/CARC domains. The MEMSAT algorithm indicates that VDR and importin-4 may not be restricted to cytoplasm and nucleus. VDR homodimer TM helix-topology predicts insertion into the plasma membrane, with two 84 residue C-terminal regions being extracellular. Similarly, MEMSAT predicts importin-4 insertion into the plasma membrane with 226 residue extracellular N-terminal regions and 96 residue C-terminal extracellular loops; with the pore-lining regions contributing gated Ca(2+) channels. The PoreWalker algorithm indicates that, of the 427 residues in each VDR monomer, 91 line the largest channel, including two vitamin D3 binding sites and residues from both the TM helix and "half-helix". Cholesterol-binding domains also extend into the channel within the ligand binding region. Programmed changes in bound cholesterol may regulate both membrane Ca(2+) response systems and vitamin D3 uptake as well as receptor internalization by the endomembrane system culminating in uptake of the vitamin D3-VDR-importin-4 complex into the nucleus. PMID:27369077

  14. Vitamin D3: A Role in Dopamine Circuit Regulation, Diet-Induced Obesity, and Drug Consumption.

    PubMed

    Trinko, Joseph R; Land, Benjamin B; Solecki, Wojciech B; Wickham, Robert J; Tellez, Luis A; Maldonado-Aviles, Jaime; de Araujo, Ivan E; Addy, Nii A; DiLeone, Ralph J

    2016-01-01

    The influence of micronutrients on dopamine systems is not well defined. Using mice, we show a potential role for reduced dietary vitamin D3 (cholecalciferol) in promoting diet-induced obesity (DIO), food intake, and drug consumption while on a high fat diet. To complement these deficiency studies, treatments with exogenous fully active vitamin D3 (calcitriol, 10 µg/kg, i.p.) were performed. Nondeficient mice that were made leptin resistant with a high fat diet displayed reduced food intake and body weight after an acute treatment with exogenous calcitriol. Dopamine neurons in the midbrain and their target neurons in the striatum were found to express vitamin D3 receptor protein. Acute calcitriol treatment led to transcriptional changes of dopamine-related genes in these regions in naive mice, enhanced amphetamine-induced dopamine release in both naive mice and rats, and increased locomotor activity after acute amphetamine treatment (2.5 mg/kg, i.p.). Alternatively, mice that were chronically fed either the reduced D3 high fat or chow diets displayed less activity after acute amphetamine treatment compared with their respective controls. Finally, high fat deficient mice that were trained to orally consume liquid amphetamine (90 mg/L) displayed increased consumption, while nondeficient mice treated with calcitriol showed reduced consumption. Our findings suggest that reduced dietary D3 may be a contributing environmental factor enhancing DIO as well as drug intake while eating a high fat diet. Moreover, these data demonstrate that dopamine circuits are modulated by D3 signaling, and may serve as direct or indirect targets for exogenous calcitriol. PMID:27257625

  15. 1,25-Dihydroxyvitamin D3 prevents toluene diisocyanate-induced airway epithelial barrier disruption.

    PubMed

    Li, Wenjia; Dong, Hangming; Zhao, Haijin; Song, Jiafu; Tang, Haixiong; Yao, Lihong; Liu, Laiyu; Tong, Wancheng; Zou, Mengchen; Zou, Fei; Cai, Shaoxi

    2015-07-01

    The loss of airway epithelial integrity contributes significantly to asthma pathogenesis. Evidence suggests that vitamin D plays an important role in the prevention and treatment of asthma. However, its role in airway epithelial barrier function remains uncertain. We have previously demonstrated impaired epithelial junctions in a model of toluene diisocyanate (TDI)-induced asthma. In the present study, we hypothesized that 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] may prevent TDI-induced epithelial barrier disruption. Male BALB/c mice were dermally sensitized and then challenged with TDI. The mice were then administered 1,25(OH)2D3 intraperitoneally prior to challenge with TDI. For in vitro experiments, 16HBE bronchial epithelial cells were cultured and stimulated with TDI-human serum albumin (HSA). The results revealed that the mice treated with 1,25(OH)2D3 displayed decreased airway hyperresponsiveness (AHR), suppressed neutrophil and eosinophil infiltration into the airways, as well as an increased E-cadherin and zonula occludens-1 (ZO-1) expression at the cell-cell contact sites. In vitro, exposure of the cells to TDI-HSA induced a rapid decline in transepithelial electrical resistance (TER) and an increase in cell permeability, followed by a decrease in occludin expression and the redistribution of E-cadherin, accompanied by a significant upregulation in the levels of phosphorylated extracellular signal-regulated kinase (ERK)1/2. These effects were all partly reversed by treatment with either 1,25(OH)2D3 or an ERK1/2 inhibitor. In conclusion, the findings of our study demonstrate that 1,25(OH)2D3 prevents TDI-induced epithelial barrier disruption, and that the ERK1/2 pathway may play a role in this process. PMID:25998793

  16. Protective effects of vitamin D3 against d-galactosamine-induced liver injury in rats.

    PubMed

    Colakoglu, Neriman; Kuloglu, Tuncay; Ozan, Enver; Kocaman, Nevin; Dabak, Durrin Ozlem; Parlak, Gozde

    2016-08-01

    In this study, we examined liver damage induced by d-galactosamine (d-GaIN) and the protective effects of vitamin D3 in relation to d-GaIN toxicity. Twenty Wistar albino rats were used in this study. The rats were divided into four groups. Group I rats were used as the control group. Group II rats were given a single intraperitoneal injection of d-GaIN. Group III rats were given a single intraperitoneal injection of d-GaIN, intramuscular vitamin D3 for five days. Group IV rats were given intramuscular vitamin D3 for five days. All of rats were euthanized by cervical decapitation on the fifth day of experiment. Upon completion of the experiment, a midsaggital incision was performed, and the livers of all rats were removed and fixed. The livers were processed to perform TUNEL technique and histochemical staining. During the microscope examination, we observed inflamatory cell infiltration, sinusoidal dilatation, and apoptotic bodies due to d-GaIN exposure. In addition, glycogen content of the group II hepatocytes was significantly decreased. Vitamin D3 treatment provided better structural apperance of the livers in group III. TUNEL positive cells were extremly pervasive in the group II livers. The study found group III TUNEL positive cells at a reduced rate in relation to group II due to vitamin D3 treatment. This findings indicate that d-GaIN causes inflamation in the liver. This inflamation triggers the apoptotic process gradually. Vitamin D3 has potency to decrease the severity of d-GaIN-caused structural liver damage. PMID:27291692

  17. The Association of 25-Hydroxyvitamin D3 and D2 with Behavioural Problems in Childhood

    PubMed Central

    Tolppanen, Anna-Maija; Sayers, Adrian; Fraser, William D.; Lewis, Glyn; Zammit, Stanley; Lawlor, Debbie A.

    2012-01-01

    Background Higher serum concentrations of 25-hydroxyvitamin D (25(OH)D), an indicator of vitamin D synthesis and intake, have been associated with better mental health and cognitive function. Concentrations of 1,25-dihydroxyvitamin D3 (the active vitamin D3 metabolite) have been associated with openness and extrovert behaviour, but 25(OH)D concentrations have not been associated with behavioural problems in humans. Methods We investigated the prospective association between the different forms of 25(OH)D - 25(OH)D3 and 25(OH)D2– and childhood behavioural problems in Avon Longitudinal Study of Parents and Children (ALSPAC). Serum 25(OH)D3 and 25(OH)D2 concentrations were assessed at mean age 9.9 years. Incident behavioural problems were assessed with Strengths and Difficulties Questionnaire (SDQ; emotional symptoms, conduct problems, hyperactivity-inattention problems, peer relationship problems and pro-social behaviour subscales and total difficulties score) at mean age 11.7. Sample sizes varied between 2413-2666 depending on the outcome. Results Higher 25(OH)D3 concentrations were weakly associated with lower risk of prosocial problems (fully adjusted odds ratio: OR (95% confidence interval: CI) 0.85 (0.74, 0.98)). Serum 25(OH)D3 or 25(OH)D2 concentrations were not associated with other subscales of SDQ or total difficulties score after adjusting for concfounders and other measured analytes related to vitamin D. Conclusions Our findings do not support the hypothesis that 25-hydroxyvitamin D status in childhood has important influences on behavioural traits in humans. PMID:22808099

  18. Whole cell bioconversion of vitamin D3 to calcitriol using Pseudonocardia sp. KCTC 1029BP.

    PubMed

    Kang, Dae-Jung; Im, Jong-Hyuk; Kang, Jae-Hoon; Kim, Kyoung Heon

    2015-07-01

    Calcitriol is an important drug used for treating osteoporosis, which can be produced from vitamin D3. The current method of producing calcitriol from vitamin D3 during cultivation of microbial cells results in low yields of calcitriol and high purification costs. Therefore, in this study, the steps of cell cultivation and bioconversion of vitamin D3 to calcitriol were separated. Cells of Pseudonocardia sp. KCTC 1029BP were utilized as a whole cell catalyst to produce a high level and yield of calcitriol from vitamin D3. In addition, the effects of bioconversion buffers, cyclodextrins, and metal salts on the production of calcitriol were comparatively examined and selected for incorporation in the bioconversion medium, and their compositions were statistically optimized. The optimal bioconversion medium was determined as consisting of 15 mM Trizma base, 25 mM sodium succinate, 2 mM MgSO4, 0.08% β-cyclodextrin, 0.1% NaCl, 0.2% K2HPO4, and 0.03% MnCl2. Using this optimal bioconversion medium, 61.87 mg/L of calcitriol, corresponding to a 30.94% mass yield from vitamin D3, was produced in a 75-L fermentor after 9 days. This calcitriol yield was 3.6 times higher than that obtained using a bioconversion medium lacking β-cyclodextrin, NaCl, K2HPO4, and MnCl2. In conclusion, utilizing whole cells of Pseudonocardia sp. KCTC 1029BP together with the optimal bioconversion medium markedly enhanced the production of calcitriol from vitamin D3. PMID:25666830

  19. Stability of Vitamin D3 in fortified yoghurt and yoghurt drink (Doogh)

    PubMed Central

    Jafari, Tina; Askari, Gholamreza; Mirlohi, Maryam; Javanmard, Shaghayegh Haghjooy; Faghihimani, Elham; Fallah, Aziz A

    2016-01-01

    Background: Vitamin D deficiency and insufficiency are recognized as a worldwide problem with serious consequences. Fortification of foods with Vitamin D is a certain approach to improve serum Vitamin D status if the stability of vitamin in the foodstuffs was controlled. The purpose of this study was to examine the stability of Vitamin D3 added to low-fat yogurt and yogurt drink “Doogh” during the products shelf-life. Materials and Methods: Two kinds of Vitamin D3, water- and oil-dispersible forms, suitable for food fortification, were compared to find out whether they show different stability in the products. The products were packed in opaque or translucent containers. The content of Vitamin D3 was determined by high performance liquid chromatography method. Results: Vitamin D was not affected by the heat treatment (pasteurization) and other processes (homogenization and fermentation). Both water- and oil-dispersible forms were stable during the shelf-life of yogurt samples packed in opaque containers. The Vitamin D3 content of yogurt fortified with water-dispersible form and packed in translucent containers was not stable during the shelf-life and significantly reduced after 1, 2, and 3 weeks of storage compared to the day 0. The Vitamin D3 content of samples fortified with the oil-dispersible form packed in the same container was only stable after 1-week and significantly reduced after 2 and 3 weeks of storage. The Vitamin D3 content of Doogh packed in the opaque containers remained stable during the shelf-life while it was not stable in the samples packed in translucent containers. Conclusion: The results suggested that both forms of Vitamin D are suitable for fortification, and opaque container is a better choice for packaging of the product. PMID:27110549

  20. Effects of Ti-C:H coating and plasma nitriding treatment on tribological, electrochemical, and biocompatibility properties of AISI 316L.

    PubMed

    Kao, W H; Su, Y L; Horng, J H; Zhang, K X

    2016-08-01

    Ti-C:H coatings were deposited on original, nitrided, and polished-nitrided AISI 316L stainless steel substrates using a closed field unbalanced magnetron sputtering system. Sliding friction wear tests were performed in 0.89 wt.% NaCl solution under a load of 30 N against AISI 316L stainless steel, Si3N4, and Ti6Al4V balls, respectively. The electrochemical properties of the various specimens were investigated by means of corrosion tests performed in 0.89 wt.% NaCl solution at room temperature. Finally, the biocompatibility properties of the specimens were investigated by performing cell culturing experiments using purified mouse leukemic monocyte macrophage cells (Raw264.7). In general, the results showed that plasma nitriding followed by Ti-C:H coating deposition provides an effective means of improving the wear resistance, anti-corrosion properties, and biocompatibility performance of AISI 316L stainless steel. PMID:27422714