Log in

Relevant bibliographies by topics / AA 2219 / Journal articles

To see the other types of publications on this topic, follow the link: AA 2219.

Journal articles on the topic 'AA 2219'

Author: Grafiati

Published: 6 September 2023

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 journal articles for your research on the topic 'AA 2219.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.

1

Srinivasa Rao, P., K. G. Sivadasan, and P. K. Balasubramanian. "Structure-property correlation on AA 2219 aluminium alloy weldments." Bulletin of Materials Science 19, no. 3 (June 1996): 549–57. http://dx.doi.org/10.1007/bf02744827.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Venkateswarlu, D., P. Nageswara rao, M. M. Mahapatra, S. P. Harsha, and N. R. Mandal. "Processing and Optimization of Dissimilar Friction Stir Welding of AA 2219 and AA 7039 Alloys." Journal of Materials Engineering and Performance 24, no. 12 (November 23, 2015): 4809–24. http://dx.doi.org/10.1007/s11665-015-1779-4.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

Santhana Babu, A. V., P. K. Giridharan, P. Ramesh Narayanan, and S. V. S. Narayana Murty. "Microstructural Investigations on ATIG and FBTIG Welding of AA 2219 T87 Aluminum Alloy." Applied Mechanics and Materials 592-594 (July 2014): 489–93. http://dx.doi.org/10.4028/www.scientific.net/amm.592-594.489.

Full text

Abstract:

Limitation in penetration depth is a concern in conventional TIG welding process. To improve penetration capability of TIG process, both Activated TIG (ATIG) and Flux Bounded TIG (FBTIG) are investigated in aluminum alloy AA 2219 T87. Undesirable arc wandering and cracking tendency are observed in ATIG welds. Microstructural investigation reveals ATIG welds are prone for liquation cracks. Morphology of the cracks along with the attributable factors are explained with optical and SEM (Scanning Electron Microscope) micrographs. Energy Dispersive Spectroscopy (EDS) results are also presented to explain the solute enrichment in the grain boundaries of the ATIG welds. FBTIG is found to produce good quality welds and is more suitable for welding aluminum alloys. Key words: Flux Assisted TIG; ATIG; FBTIG; Penetration Improvement; Microstructure; AA2219.

APA, Harvard, Vancouver, ISO, and other styles

4

Huang, Y. X., B. Han, S. X. Lv, J. C. Feng, H. J. Liu, J. S. Leng, and Y. Li. "Interface behaviours and mechanical properties of filling friction stir weld joining AA 2219." Science and Technology of Welding and Joining 17, no. 3 (April 2012): 225–30. http://dx.doi.org/10.1179/1362171811y.0000000100.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

Owolabi, G. M., D. T. Bolling, A. A. Tiamiyu, R. Abu, A. G. Odeshi, and H. A. Whitworth. "Shear strain localization in AA 2219-T8 aluminum alloy at high strain rates." Materials Science and Engineering: A 655 (February 2016): 212–20. http://dx.doi.org/10.1016/j.msea.2015.12.100.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Du, Bo, Lei Cui, Xinqi Yang, Dongpo Wang, and Zhuanping Sun. "Weakening mechanism and tensile fracture behavior of AA 2219-T87 friction plug welds." Materials Science and Engineering: A 693 (May 2017): 129–35. http://dx.doi.org/10.1016/j.msea.2017.03.093.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Karthik, A., R. Karunanithi, S. A. Srinivasan, and M. Prashanth. "Microstructure and mechanical properties of AA 2219-TiB2 composites by squeeze casting technique." Materials Today: Proceedings 27 (2020): 2574–81. http://dx.doi.org/10.1016/j.matpr.2019.10.143.

Full text

APA, Harvard, Vancouver, ISO, and other styles

8

Mastanaiah, P., G. Madhusudan Reddy, Anirban Bhattacharya, Angshuman Kapil, and Abhay Sharma. "Unveiling Liquation and Segregation Induced Failure Mechanism in Thick Dissimilar Aluminum Alloy Electron-Beam Welds." Metals 12, no. 3 (March 13, 2022): 486. http://dx.doi.org/10.3390/met12030486.

Full text

Abstract:

This study presents new findings on the underlying failure mechanism of thick dissimilar electron-beam (EB) welds through a study on the AA 2219-AA 5083 pair. Contrary to the prior studies on EB welding of thin Al alloys, where liquation in the grain boundaries (GBs) in the partially melted zone (PMZ) was not observed, the present investigation for thick EB welds reports both liquation and increased segregation of Cu in the PMZ. The work is thus directed towards understanding the unusual observation in the PMZ of thick EB weld through investigation of the microstructural variation across the various regions of the produced weld. The microstructural results are correlated with the mechanical properties of the weld, i.e., hardness variation and tensile response. Results of this investigation suggest that unlike the convention that EB welding produces sound dissimilar Al welds, the weld performance for thick EB Al welds is affected by the heat input, the associated cooling rates, and most importantly by the base material thickness. Extensive liquation and Cu segregation induced failure in the PMZ on the AA 2219 side of the dissimilar weld. The underlying failure mechanism is explained through a heat-transfer analysis. Beyond a certain plate thickness, the heat transfer changes from two to three-dimensional. As a result, retarded cooling promotes liquation and Cu segregation in thick EB welds.

APA, Harvard, Vancouver, ISO, and other styles

9

Murty, S. V. S. Narayana, Aditya Sarkar, P. Ramesh Narayanan, P. V. Venkitakrishnan, and J. Mukhopadhyay. "Microstructure and micro-texture evolution during large strain deformation of aluminium alloy AA 2219." Materials Science and Engineering: A 677 (November 2016): 41–49. http://dx.doi.org/10.1016/j.msea.2016.09.027.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

Jha, Abhay K., S. V. S. N. Murty, K. Sreekumar, and P. P. Sinha. "High strain rate deformation and cracking of AA 2219 aluminium alloy welded propellant tank." Engineering Failure Analysis 16, no. 7 (October 2009): 2209–16. http://dx.doi.org/10.1016/j.engfailanal.2009.03.001.

Full text

APA, Harvard, Vancouver, ISO, and other styles

11

Babu, N. Kishore, D. Pan, Z. Sun, J. Wei, and M. K. Talari. "Effect of titanium–boron additions on grain refinement of AA 2219 gas tungsten arc welds." Science and Technology of Welding and Joining 17, no. 5 (July 2012): 386–93. http://dx.doi.org/10.1179/1362171812y.0000000020.

Full text

APA, Harvard, Vancouver, ISO, and other styles

12

Santhana Babu, A. V., P. K. Giridharan, P. Ramesh Narayanan, and S. V. S. Narayana Murty. "Prediction of Bead Geometry for Flux Bounded TIG Welding of AA 2219-T87 Aluminum Alloy." Journal of Advanced Manufacturing Systems 15, no. 02 (April 27, 2016): 69–84. http://dx.doi.org/10.1142/s0219686716500074.

Full text

Abstract:

To improve penetration capability of Tungsten Inert Gas (TIG) process, Flux Bounded TIG (FBTIG) is investigated in aluminum alloy AA 2219 T87. Characterization of this process is essential to predict and control the weld bead quality. For characterization, design of experiments based on central composite rotatable design is employed for the experiments. Response Surface Methodology (RSM) is used to develop a mathematical model to correlate the bead geometry with controllable process variables. The model developed is checked for its adequacy by regression by using the [Formula: see text]-test and Analysis of Variance (ANOVA). By backward elimination method, reduced model is obtained from the full model. The process parameters are optimized to get desired weld bead geometry. The model is validated by confirmatory tests. The main and interaction effects of the process variables on bead geometry are presented in graphical form. The results are useful to predict the weld bead geometry for different combinations of process variables.

APA, Harvard, Vancouver, ISO, and other styles

13

Ananda Rao, G., and N. Ramanaiah. "Dissimilar metals AISI 304 steel and AA 2219 aluminium alloy joining by friction welding method." Materials Today: Proceedings 19 (2019): 902–7. http://dx.doi.org/10.1016/j.matpr.2019.09.028.

Full text

APA, Harvard, Vancouver, ISO, and other styles

14

Babu, S., S. K. Panigrahi, G. D. Janaki Ram, P. V. Venkitakrishnan, and R. Suresh Kumar. "Cold metal transfer welding of aluminium alloy AA 2219 to austenitic stainless steel AISI 321." Journal of Materials Processing Technology 266 (April 2019): 155–64. http://dx.doi.org/10.1016/j.jmatprotec.2018.10.034.

Full text

APA, Harvard, Vancouver, ISO, and other styles

15

Karthik, G. M., G. D. Janaki Ram, and Ravi Sankar Kottada. "Heat-Affected Zone Liquation Cracking Resistance of Friction Stir Processed Aluminum-Copper Alloy AA 2219." Metallurgical and Materials Transactions B 48, no. 2 (December 27, 2016): 1158–73. http://dx.doi.org/10.1007/s11663-016-0892-6.

Full text

APA, Harvard, Vancouver, ISO, and other styles

16

Surekha, K., B. S. Murty, and K. Prasad Rao. "Comparison of corrosion behaviour of friction stir processed and laser melted AA 2219 aluminium alloy." Materials & Design 32, no. 8-9 (September 2011): 4502–8. http://dx.doi.org/10.1016/j.matdes.2011.03.033.

Full text

APA, Harvard, Vancouver, ISO, and other styles

17

Priya, R., V. Subramanya Sarma, and K. Prasad Rao. "Effect of post weld heat treatment on the microstructure and tensile properties of dissimilar friction stir welded AA 2219 and AA 6061 alloys." Transactions of the Indian Institute of Metals 62, no. 1 (February 2009): 11–19. http://dx.doi.org/10.1007/s12666-009-0002-4.

Full text

APA, Harvard, Vancouver, ISO, and other styles

18

Zhang, C., M. Gao, G. Li, C. Chen, and X. Y. Zeng. "Strength improving mechanism of laser arc hybrid welding of wrought AA 2219 aluminium alloy using AlMg5wire." Science and Technology of Welding and Joining 18, no. 8 (November 2013): 703–10. http://dx.doi.org/10.1179/1362171813y.0000000153.

Full text

APA, Harvard, Vancouver, ISO, and other styles

19

Surekha, K., B. S. Murty, and K. Prasad Rao. "Effect of processing parameters on the corrosion behaviour of friction stir processed AA 2219 aluminum alloy." Solid State Sciences 11, no. 4 (April 2009): 907–17. http://dx.doi.org/10.1016/j.solidstatesciences.2008.11.007.

Full text

APA, Harvard, Vancouver, ISO, and other styles

20

Su, Hongliang, Liang Huang, Jianjun Li, Wang Xiao, Hui Zhu, Fei Feng, Hongwei Li, and Siliang Yan. "Formability of AA 2219-O sheet under quasi-static, electromagnetic dynamic, and mechanical dynamic tensile loadings." Journal of Materials Science & Technology 70 (April 2021): 125–35. http://dx.doi.org/10.1016/j.jmst.2020.07.023.

Full text

APA, Harvard, Vancouver, ISO, and other styles

21

Riaz, Asim Ahmad, Naveed Ullah, Ghulam Hussain, Mohammed Alkahtani, Muhammad Naeem Khan, and Shaukat Khan. "Experimental Investigations on the Effects of Rotational Speed on Temperature and Microstructure Variations in Incremental Forming of T6- Tempered and Annealed AA2219 Aerospace Alloy." Metals 10, no. 6 (June 17, 2020): 809. http://dx.doi.org/10.3390/met10060809.

Full text

Abstract:

This research work primarily focused on investigating the effects of changing rotational speed on the forming temperature and microstructure during incremental sheet metal forming (ISF) of AA-2219-O and AA-2219-T6 sheets. Tool rotational speed was varied in the defined range (50–3000 rpm). The tool feed rate of 3000 mm/min and step size of 0.3 mm with spiral tool path were kept fixed in the tests. The sheets were formed into pyramid shapes of 45° draw angle, with the hemispherical end forming tool of 12 mm diameter. While the sheets were forming, the temperature variation due to friction at the sheet–tool contact zone was recorded, using a non-contact laser projected infrared temperature sensor. It was observed that the temperature rising rate for the T6 sheet during ISF is higher as compared to the annealed sheet, thereby showing that the T6 tempered sheet offers higher friction than the annealed sheet. Due to this reason, the T6 tempered sheet fails to achieve the defined forming depth of 25 mm when the rotational speed exceeds 2000 rpm. The effects of rotational speed and associated rise in the temperature were examined on the microstructure, using the scanning electron microscopic (SEM). The results reveal that the density of second phase particles reduces with increasing speed reasoning to corresponding temperature rise. However, the particle size in both tempers of AA2219 received a slight change and showed a trivial response to an increase in the rotational speed.

APA, Harvard, Vancouver, ISO, and other styles

22

Venkitakrishnan, P. V., P. P. Sinha, and R. Krishnamurthy. "Study and analysis of effect of various thermal processes in AA 2219 annealed sheet using acoustic emissions." Materials & Design 27, no. 9 (January 2006): 770–75. http://dx.doi.org/10.1016/j.matdes.2005.01.019.

Full text

APA, Harvard, Vancouver, ISO, and other styles

23

Sharma, V. M. J., K. Sree Kumar, B. Nageswara Rao, and S. D. Pathak. "Effect of aging treatments on the fatigue crack growth and threshold behavior of AA 2219 aluminium alloy." Transactions of the Indian Institute of Metals 63, no. 2-3 (April 2010): 535–40. http://dx.doi.org/10.1007/s12666-010-0078-x.

Full text

APA, Harvard, Vancouver, ISO, and other styles

24

Owolabi, G. M., D. T. Bolling, A. G. Odeshi, H. A. Whitworth, N. Yilmaz, and A. Zeytinci. "The Effects of Specimen Geometry on the Plastic Deformation of AA 2219-T8 Aluminum Alloy Under Dynamic Impact Loading." Journal of Materials Engineering and Performance 26, no. 12 (November 13, 2017): 5837–46. http://dx.doi.org/10.1007/s11665-017-3061-4.

Full text

APA, Harvard, Vancouver, ISO, and other styles

25

Reimann, Martin, Jannik Goebel, and Jorge F. dos Santos. "Microstructure Evolution and Mechanical Properties of Keyhole Repair Welds in AA 2219-T851 Using Refill Friction Stir Spot Welding." Journal of Materials Engineering and Performance 27, no. 10 (July 19, 2018): 5220–26. http://dx.doi.org/10.1007/s11665-018-3519-z.

Full text

APA, Harvard, Vancouver, ISO, and other styles

26

Santhana Babu, A. V., P. K. Giridharan, A. Venugopal, P. Ramesh Narayanan, and S. V. S. Narayana Murty. "Stress Corrosion Cracking Behaviour of Flux Bounded TIG Welded AA2219 T87 Aluminum Alloy in 3.5 Weight Percent NaCl Solution." Applied Mechanics and Materials 766-767 (June 2015): 733–38. http://dx.doi.org/10.4028/www.scientific.net/amm.766-767.733.

Full text

Abstract:

Limitation in penetration depth is a concern in conventional TIG welding. To improve penetration capability of TIG process, Flux Bounded TIG (FBTIG) has been developed. Stress corrosion cracking (SCC) behavior of FBTIG welds of aluminum alloy AA 2219 T87 is evaluated in 3.5 weight percent NaCl solution using Slow Strain Rate Test technique (SSRT) as per ASTM G129. SCC index defined as the ratio of the elongation of tensile tested specimen in NaCl to that of air is taken as a measure of the susceptibility to cracking. Based on the SCC index, it is concluded that the SCC resistance of FBTIG joints are good and comparable to that of conventional TIG welds.

APA, Harvard, Vancouver, ISO, and other styles

27

Prabhu, T. Ram. "Effects of ageing time on the mechanical and conductivity properties for various round bar diameters of AA 2219 Al alloy." Engineering Science and Technology, an International Journal 20, no. 1 (February 2017): 133–42. http://dx.doi.org/10.1016/j.jestch.2016.06.003.

Full text

APA, Harvard, Vancouver, ISO, and other styles

28

Murty, S. V. S. Narayana, Sushant K. Manwatkar, and P. Ramesh Narayanan. "Role of Metallographic Analysis in the Identification of Location of Crack Initiation in a Burst Tested AA 2219 Propellant Tank." Metallography, Microstructure, and Analysis 4, no. 5 (September 16, 2015): 392–402. http://dx.doi.org/10.1007/s13632-015-0223-3.

Full text

APA, Harvard, Vancouver, ISO, and other styles

29

Venugopal, A., J. Srinath, P. Ramesh Narayanan, S. C. Sharma, and Koshy M. George. "Corrosion and Multi-Scale Mechanical Behaviour of Plasma Electrolytic Oxidation (PEO) and Hard Anodized (HA) Coatings on AA 2219 Aluminum Alloy." Materials Science Forum 830-831 (September 2015): 627–30. http://dx.doi.org/10.4028/www.scientific.net/msf.830-831.627.

Full text

Abstract:

The electrochemical corrosion and mechanical properties of ceramic coatings fabricated by plasma electrolytic coating (PEO) and hard anodizing (HA) methods comparatively examined for AA2219. Potentiodynamic polarization results revealed that the corrosion resistance of both coatings are comparable to each other. However, the indentation and scratch testing indicated that the hardness and modulus of the PEO coating was significantly higher when compared to HA coating. The critical load (Lc2) causing adhesive failure of the PEO coating was much high (19N) when compared to HA coating (10N) showing better adhesive strength of the PEO coating.Key words: Plasma electrolytic oxidation (PEO), potentiodynamic polarization, nanoindentation, hard anodizing

APA, Harvard, Vancouver, ISO, and other styles

30

Venkitakrishnan, P. V., P. P. Sinha, and R. Krishnamurthy. "Study and analysis of residual stresses due to various secondary processes in AA 2219 annealed sheet using acoustic emission and hole drilling methods." NDT & E International 38, no. 8 (December 2005): 615–22. http://dx.doi.org/10.1016/j.ndteint.2005.02.010.

Full text

APA, Harvard, Vancouver, ISO, and other styles

31

Rajasekaran, N. R., and V. Sampath. "Effect of In-Situ TiB<sub>2</sub> Particle Addition on the Mechanical Properties of AA 2219 Al Alloy Composite." Journal of Minerals and Materials Characterization and Engineering 10, no. 06 (2011): 527–34. http://dx.doi.org/10.4236/jmmce.2011.106040.

Full text

APA, Harvard, Vancouver, ISO, and other styles

32

Swathi Kiranmayee, M., Abhay Kumar Jha, Sushant K. Manwatkar, P. Ramesh Narayanan, K. Sreekumar, and Parameshwar Prasad Sinha. "Microstructural Characterisation of AA2219 Weldments." Materials Science Forum 710 (January 2012): 638–43. http://dx.doi.org/10.4028/www.scientific.net/msf.710.638.

Full text

Abstract:

Aluminium alloy AA 2219 has been selected for fabrication of both earth storable and cryogenic propellant tanks of launch vehicles due to its high specific strength, compatibility with liquid propellants, good resistance to stress corrosion cracking (SCC), excellent properties at cryogenic temperatures and good fabricability including weldability. Propellant tanks are fabricated by welding sheets in T87 and rings in T851 temper conditions. Microstructural characterization was carried out on the weldments with sheet-sheet and sheet-forge configuration using optical microscopy and electron microscopy with energy dispersive spectroscopy. Microstructure of weld pool had dendritic pattern, typical of weld cast structure. Fine recrystallised grains were observed near fusion line. Heat affected zone on either side of the weld revealed thickened grain boundaries. EDS on these thickened grain boundaries indicated composition of eutectic. Microhardness and tensile strength for both the configurations was evaluated. Fractures surface of tensile tested specimens were examined for fracture morphology and to understand the role of eutectic film in fracture. Presence of the eutectic film along the grain boundaries was explained with the help of liquation mechanism and Al-Cu phase diagram. This paper brings out details of the investigation carried out.

APA, Harvard, Vancouver, ISO, and other styles

33

Dorange, Fabien, Slimane El Mehdaoui, Chantal Pichon, Pierre Coursaget, and Jean-François Vautherot. "Marek’s disease virus (MDV) homologues of herpes simplex virus type 1 UL49 (VP22) and UL48 (VP16) genes: high-level expression and characterization of MDV-1 VP22 and VP16." Journal of General Virology 81, no. 9 (September 1, 2000): 2219–30. http://dx.doi.org/10.1099/0022-1317-81-9-2219.

Full text

Abstract:

Genes UL49 and UL48 of Marek’s disease virus 1 (MDV-1) strain RB1B, encoding the respective homologues of herpes simplex virus type 1 (HSV-1) genes VP22 and VP16, were cloned into a baculovirus vector. Seven anti-VP22 MAbs and one anti-VP16 MAb were generated and used to identify the tegument proteins in cells infected lytically with MDV-1. The two genes are known to be transcribed as a single bicistronic transcript, and the detection of only one of the two proteins (VP22) in MSB-1 lymphoma and in chicken embryo skin cells infected with MDV-1 prompted the study of the transcription/translation of the UL49–48 sequence in an in vivo and in vitro expression system. VP16 was expressed in vitro at detectable levels, whereas it could only be detected at a lower level in a more controlled environment. It was demonstrated that VP22 is phosphorylated in insect cells and possesses the remarkable property of being imported into all cells in a monolayer. VP22 localized rapidly and efficiently to nuclei, like its HSV-1 counterpart. The DNA-binding property of VP22 is also reported and a part of the region responsible for this activity was identified between aa 16 and 37 in the N-terminal region of the protein.

APA, Harvard, Vancouver, ISO, and other styles

34

Schmoeller, Maximilian, Christian Stadter, Michael Karl Kick, Christian Geiger, and Michael Friedrich Zaeh. "A Novel Approach to the Holistic 3D Characterization of Weld Seams—Paving the Way for Deep Learning-Based Process Monitoring." Materials 14, no. 22 (November 16, 2021): 6928. http://dx.doi.org/10.3390/ma14226928.

Full text

Abstract:

In an industrial environment, the quality assurance of weld seams requires extensive efforts. The most commonly used methods for that are expensive and time-consuming destructive tests, since quality assurance procedures are difficult to integrate into production processes. Beyond that, available test methods allow only the assessment of a very limited set of characteristics. They are either suitable for determining selected geometric features or for locating and evaluating internal seam defects. The presented work describes an evaluation methodology based on microfocus X-ray computed tomography scans (µCT scans) which enable the 3D characterization of weld seams, including internal defects such as cracks and pores. A 3D representation of the weld contour, i.e., the complete geometry of the joint area in the component with all quality-relevant geometric criteria, is an unprecedented novelty. Both the dimensions of the weld seam and internal defects can be revealed, quantified with a resolution down to a few micrometers and precisely assigned to the welded component. On the basis of the methodology developed within the framework of this study, the results of the scans performed on the alloy AA 2219 can be transferred to other aluminum alloys. In this way, the data evaluation framework can be used to obtain extensive reference data for the calibration and validation of inline process monitoring systems employing Deep Learning-based data processing in the scope of subsequent work.

APA, Harvard, Vancouver, ISO, and other styles

35

Ejaz, N., W. Muhammad, and I. Salam. "Fatigue Crack Growth Behavior in a Rolled Plate of Aluminum Alloy." Key Engineering Materials 442 (June 2010): 283–93. http://dx.doi.org/10.4028/www.scientific.net/kem.442.283.

Full text

Abstract:

Aluminum alloys generally contain constituent particles. The population density and size these particles are important while considering fatigue performance. In present study, the crack growth process in stage II in the rolled plate of a high strength aluminum alloy AA 2219 was studied on samples prepared along the rolling direction. A three fold approach was adopted to understand the fatigue crack growth process: i) microstructural analysis ii) fatigue testing iii) post-fracture analysis. Microstructural analysis revealed a high density of constituent particles in the material. EDS analysis showed that the particles were mainly of CuAl2 type. However, particles with high concentration of Fe and Mn were also present in the material. Fatigue crack propagation tests were performed by using middle tension (MT) specimens prepared in rolling direction under constant amplitude loads. The da/dN vs ΔK plot on log-log scale showed a sigmoidal shape with a sharp increase of crack growth rate in the steady state regime. Topographical features were studied to understand the interaction of fatigue crack with the microstructural features. Post fracture analysis revealed that the macro fracture appearance changed with the change of stress level. However, the general mechanism of crack growth, in all the stress levels studied, was by formation of striations. At lower stress levels almost flat region with striations is present upto the final fracture. The crack growth surface showed crystallographic features with crack propagation almost perpendicular to the loading direction. However, a comparatively tortuous fatigue region was evident in the sample tested at high level of stress. The observation of crack path surface at high magnification did not reveal any influence of particles on the crack growth process. However, in sections taken from the fractured samples cracking and debonding of the constituent particles was observed near the fatigue crack path.

APA, Harvard, Vancouver, ISO, and other styles

36

Hamouz, K., J. Lachman, P. Dvořák, O. Dušková, and M. Čížek. "Effect of conditions of locality, variety and fertilization on the content of ascorbic acid in potato tubers." Plant, Soil and Environment 53, No. 6 (January 7, 2008): 252–57. http://dx.doi.org/10.17221/2217-pse.

Full text

Abstract:

The effect of conditions of locality, variety and fertilization on ascorbic acid (AA) content in potato tubers was investigated in precise field trials in 2004 and 2005 in the Czech Republic. From four localities and in the two-year average the highest AA was statistically determined in the locality of Prerov nad Labem with the highest average temperature values during both experimental years (by 6.7 to 11.5% higher in comparison to other localities). Similarly, the effect of variety was also very significant; Marabel variety had the highest AA content (207.2 mg/kg fw) and exceeded other seven varieties by 15−49%. A negative effect on AA content in tubers was observed in the case of an increased intensity of N fertilization (at 180 kg N/ha AA decrease was lower by 6.1% compared to doses 100 kg N/ha). On the contrary, a favourable effect was determined at increased levels of potassium and magnesium fertilization (at 166 kg K/ha and 60 kg Mg/ha AA increase was by 6.2% higher compared to the levels of 108 kg K/ha and 30 kg Mg/ha).

APA, Harvard, Vancouver, ISO, and other styles

37

Chen, Ssu-Ta, Truan-Sheng Lui, and Li-Hui Chen. "Microstructural Stability of Friction Stirred AA 2218 Alloy on Tensile Properties at Elevated Temperature." MATERIALS TRANSACTIONS 48, no. 3 (2007): 510–14. http://dx.doi.org/10.2320/matertrans.48.510.

Full text

APA, Harvard, Vancouver, ISO, and other styles

38

Park, Soo-Kyung, Hak-Soo Kim, Hyo-Joon Yang, Yoon Suk Jung, Jung Ho Park, Chong Il Sohn, Sang Hyun Park, Jin Hee Sohn, Mi Yeon Lee, and Dong Il Park. "Coexistent adenoma and serrated polyps on index colonoscopy and the risk of metachronous advanced colorectal neoplasia." Endoscopy International Open 07, no. 12 (December 2019): E1748—E1754. http://dx.doi.org/10.1055/a-1019-2976.

Full text

Abstract:

Abstract Background and aims The family of serrated polyps (SP) includes hyperplastic polyps (HP), sessile serrated adenomas/polyps, and traditional serrated adenoma. We investigated whether SP synchronous with adenoma at index colonoscopy is associated with metachronous advanced colorectal neoplasia (CRN). Methods Patients with ≥ 1 adenoma on index colonoscopy and who had undergone a follow-up colonoscopy were included. The patients were divided into four groups according to the presence of SP and advanced adenoma (AA) on index colonoscopy (non-AA, non-AA + SP, AA, AA + SP). The cumulative incidence of metachronous advanced CRN at surveillance colonoscopy was compared between groups. Results Among a total of 2209 patients, the numbers of patients in the non-AA, non-AA + SP, AA, and AA + SP groups were 922, 441, 625, and 221, respectively. The cumulative incidence of metachronous advanced CRN was higher in patients in the AA + SP group than that in the AA group (P<0.001), and there was no significant difference between the non-AA + SP group and the non-AA group (P = 0.06). The cumulative incidence of metachronous advanced CRN at 3 years was 17.9 % [95 % confidence interval (CI) 8.0–27.6], 10.7 % [95 %CI 7.7–3.6], 3.5 % [95 %CI 1.3–5.6], and 3.4 % [95 %CI 2.0–4.7] in the AA + SP, AA, non-AA + SP, and non-AA group, respectively. In a multivariate analysis, overall SP [hazard ratio (HR) 2.24; 95 %CI 1.38–3.64, P = 0.001], proximal SP (HR 2.31; 95 %CI 1.32–4.08), and HP (HR 2.19; 95 %CI 1.35–3.57) were risk factors for metachronous advanced CRN in patients with AA on index colonoscopy. Conclusions Coexistent AA and SP on index colonoscopy significantly increased the risk of metachronous advanced CRN compared with AA alone. Further large prospective studies are needed to confirm whether more intensive follow-up improves outcomes in these high risk patients.

APA, Harvard, Vancouver, ISO, and other styles

39

Sharad, Shashwat, Darryl Nousome, Gregory T. Chesnut, and Hua Li. "Abstract 2210: The study of age and race genetic signatures of prostate cancer with formalin fixed paraffin embedded (FFPE) samples." Cancer Research 82, no. 12_Supplement (June 15, 2022): 2210. http://dx.doi.org/10.1158/1538-7445.am2022-2210.

Full text

Abstract:

Abstract Objectives: Diagnosis with prostate cancer (PCa) at younger age is a serious challenge in Military Health System. PCa onset at younger age is more likely to be aggressive in African American (AA) population. Also, application of formalin fixed paraffin embedded (FFPE) tissue in RNA based study was significantly hindered due to poor quality/quantity of RNA in archived pathology slides. This study is aimed to examine age/race associated gene signatures in military cohort with high representation of AA and younger population in FFPE samples for potential genetic mechanisms of health disparities and broaden tissue sample availability. Methods: A cohort of 41 Caucasian American (CA) and 20 AA non-familial PCa patients from the biospecimen bank of CPDR, WRNMMC were used. Specimens donated by radical prostatectomy patients who provided written consent and protocols approved by Institutional Review Boards. Total RNA was extracted from tumor and the adjacent normal epithelium of whole-mount FFPE tissue of matched specimens. Differential gene expression, in tumor versus normal tissues, between younger and older AA and CA patients were analyzed by NanoString using a customized CodeSet of 151 probes. The panel designed to detect 135 target transcripts, compiled from 34 genes implicated/associated with PCa progression, 27 PCa specific gene fusions, 25 cancer-associated genes, and 5 genes encoding ETS-family of transcription factors. The 27 over-expressed genes and 17 under-expressed genes in PCa were included as comparison to matched, benign epithelium. Additionally, 5 prostate stroma or epithelium specific genes were selected as control and 11 housekeeping genes were included for biological normalization. Results: The differentially expressed genes related to tumor-normal differences between AA older (66-73 years) and younger (42-58 years) as well as CA older and younger PCa patients with moderate Gleason score (3+3 and 3+4) sum were identified. After controlling for false discovery rates, panel of nine genes (ANXA2, C-MYC, VEGFR1, ERG, NPY, PSMA/FOLH1, TWIST1, MAOA, MYCN) uniquely associated with age/race were identified. Tumor vs normal ratios of ANXA2 and C-MYC expression in prostate tumors of older and younger patients were significantly enhanced. We found a clear association of VEGFR1 gene expression with CA young and c-MYC gene with AA young PCa. Conclusions: Using age/race as endpoint, we identified ANXA2, c-MYC and VEGFR1 as age and race associated PCa gene. Our findings highlight distinct racial and age-related differences and addresses the clinical utility of available genetic tests across old and young AA and CA men, which needs to be further validated in lager cohort. Further, our study also highlighted the utilization of FFPE tissue for NanoString assay and subsequent genetic signature analyses. Citation Format: Shashwat Sharad, Darryl Nousome, Gregory T. Chesnut, Hua Li. The study of age and race genetic signatures of prostate cancer with formalin fixed paraffin embedded (FFPE) samples [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2210.

APA, Harvard, Vancouver, ISO, and other styles

40

Smietniansky, Silvina. "Los tiempos de la sociedad hispano colonial: un contraste de los registros escritos de visitas y juicios de residencia." Anuário Antropológico, no. II (December 1, 2016): 95–126. http://dx.doi.org/10.4000/aa.2214.

Full text

APA, Harvard, Vancouver, ISO, and other styles

41

Clergue-Duval, Virgile, Julien Azuar, Julien Fonsart, Clément Delage, Dorian Rollet, Jihed Amami, Alexia Frapsauce, et al. "Ascorbic Acid Deficiency Prevalence and Associated Cognitive Impairment in Alcohol Detoxification Inpatients: A Pilot Study." Antioxidants 10, no. 12 (November 26, 2021): 1892. http://dx.doi.org/10.3390/antiox10121892.

Full text

Abstract:

Malnutrition has been reported in alcohol use disorder patients as having a possible influence on cognitive function. The aim of this study was to analyse the prevalence of ascorbic acid (AA) deficiency in inpatients admitted for alcohol detoxification and the associated factors, including cognitive impairment in the early period of abstinence. A retrospective chart review was conducted. The AA level was categorised into three groups: deficiency (AAD) (<2 mg/L), insufficiency (AAI) (2–5 mg/L) and normal level. The cognitive impairment was screened using the Montreal Cognitive Assessment (MoCA). Ninety-six patients were included (74 men; mean age 49.1 years (±11.5)). Twenty-seven AAD (28.1%) and twenty-two AAI (22.9%) were observed. In multivariate analysis, risk factors for AAD versus normal AA level were men (OR 17.8, 95%CI (1.63–194)), compensated cirrhosis (OR 9.35, 95%CI (1.60–54.6)) and street homelessness (OR 5.76, 95%CI (1.24–26.8) versus personal housing). The MoCA score was available for 53 patients (mean MoCA score: 25.7 (±3.3)). In multivariate analysis, the natural logarithm of AA (β = 1.18, p = 0.037) and sedative use disorder (β = −2.77, p = 0.046) were associated with the MoCA score. AAD and AAI are frequent in inpatients admitted for alcohol detoxification. A low level of AA was associated with cognitive impairment in the early period of abstinence.

APA, Harvard, Vancouver, ISO, and other styles

42

Azad, Arun, Renee Lester, Raya Leibowitz-Amit, Anthony Michael Joshua, Daniel Yick Chin Heng, Bernhard J. Eigl, and Kim N. Chi. "Population-based analysis of a novel prognostic model for metastatic castration-resistant prostate cancer (mCRPC) patients (pts) treated with abiraterone acetate (AA)." Journal of Clinical Oncology 32, no. 4_suppl (February 1, 2014): 29. http://dx.doi.org/10.1200/jco.2014.32.4_suppl.29.

Full text

Abstract:

29 Background: Using data from the COU-AA-301 trial, a novel prognostic model was recently developed for predicting overall survival (OS) in post-chemotherapy mCRPC pts treated with AA (J Clin Oncol 31, 2013 (suppl; abstr 5013)). The model is comprised of six pre-treatment risk-factors (RF) associated with poor outcome: ECOG performance status (PS) ≥ 2, presence of visceral metastases, time from start of LHRH agonists to start of AA ≤ 36 months, low albumin, high ALP and high LDH. The aim of this study was to evaluate this model in an unselected population-based cohort. Methods: Cancer registries at three Canadian centers were used to identify mCRPC pts treated with AA. OS was estimated using the Kaplan-Meier method. Multivariate Cox proportional hazard regression was used to determine independent prognostic factors for OS. Results: A total of 415 pts received AA – 286 were post-docetaxel and 129 were chemotherapy-naïve. In post-docetaxel pts, 21%, 50% and 28% were classified into good (0-1 RF), intermediate (2-3 RF) and poor (4-6 RF) prognosis (prog) groups respectively based on the COU-AA-301 model. Median OS in the post-docetaxel cohort was significantly longer for pts with good prog disease (23.9 months) compared to intermediate (17.6 months) and poor prog pts (8.4 months) (Table). ECOG PS (p<0.001), LDH (p=0.025), albumin (p=0.007) and visceral metastases (p<0.001) were confirmed as independent prognostic factors. Although the number of events in chemotherapy-naïve pts was low, median OS was significantly longer in good prog pts (not reached) compared to both intermediate (22.9 months; p=0.011, log-rank) and poor prog pts (10.3 months; p<0.001, log-rank). Conclusions: In a population-based setting, our data validate the COU-AA-301 model as a tool for prognostic stratification of mCRPC pts treated with AA after docetaxel. Prospective evaluation of this prognostic model in post-docetaxel and docetaxel-naive pts commencing AA is warranted. [Table: see text]

APA, Harvard, Vancouver, ISO, and other styles

43

Calderón Bernal, Johan Manuel, Carlos Serna, Ángel García Muñoz, Alberto Díez Guerrier, Lucas Domínguez, José Francisco Fernández-Garayzábal, Ana Isabel Vela, and Dolores Cid. "Genotypic Comparison of Pasteurella multocida from Healthy Animals at Entry to the Feedlots with That and from Bovine Respiratory Disease-Affected Animals during the Fattening Period." Animals 13, no. 17 (August 22, 2023): 2687. http://dx.doi.org/10.3390/ani13172687.

Full text

Abstract:

The aim of this study was to investigate the possible genotypic differences between commensal Pasteurella multocida isolates from apparently healthy animals (AHA) at the time of entry to feedlots and those from BRD-affected animals (BRD-AA). A total of 20 batches of beef calves in seven feedlots were followed-up during the fattening period. P. multocida was isolated from 28.1% of AHA and 22.9% of BRD-AA. All isolates belonged to the A: L3 genotype. Most isolates from clinical cases (81.0%) grouped into a PFGE cluster were significantly associated with BRD cases (OR, 24.9; 95% CI, 6.4–96.2). The whole genomes of 14 isolates representative of the pulsotypes most frequently detected in BRD-AA and AHA were sequenced and compared with 53 bovine genomes belonging to the identified ST13, ST79, and ST80 genotypes for a global comparison. No differences were found in the virulence-associated gene content between sequence types (STs) globally or between BRD-AA and AHA isolates in this study. Significantly, ST79 isolates harbored ARGs, conferring resistance to different antimicrobials, including macrolides and tetracyclines, which are commonly used for the treatment of BRD. Two Spanish ST79 isolates carried an ICE highly similar to ICE Tn7407, which was recently detected in Germany, suggesting that ST79 P. multocida isolates in Europe and North America may be associated with different ICEs.

APA, Harvard, Vancouver, ISO, and other styles

44

Daak, A. A., K. Ghebremeskel, M. I. Elbashir, A. Bakhita, Z. Hassan, and M. A. Crawford. "Hydroxyurea Therapy Mobilises Arachidonic Acid from Inner Cell Membrane Aminophospholipids in Patients with Homozygous Sickle Cell Disease." Journal of Lipids 2011 (2011): 1–8. http://dx.doi.org/10.1155/2011/718014.

Full text

Abstract:

The cytotoxic compound hydroxyurea (HU) is effective therapy for sickle cell disease. However, its effect on unsaturated membrane lipids is unknown. Red cell fatty acids were investigated in HU-treated (n=19) and HU-untreated (n=17) sickle cell patients and controls (n=20). The HU-treated compared with the HU-untreated patients had lower arachidonic (AA) acid level in ethanolamine, physphoglycerids (EPG) (22.9±1.2 versus 24.0±1.1%, P<0.05) serine SPG (22.13±2.2 versus 24.9±2.3%, P<0.01) phosphoglycerides. The treated patients and controls had comparable levels of docosahexaenoic (DHA) and total n-3 fatty acids in EPG and choline phosphoglycerides (CPG). In contrast, the untreated group had significantly (P<0.05) lower DHA and total n-3 compared with the controls in EPG (2.7±0.4 versus 3.2±0.6%and4.6±0.5 versus 5.2±0.7%) and CPG (0.7±0.2 versus 1.0±0.2%and1.2±0.2 versus 1.4±0.3). HU is known to activate cytosolic phospholipase A2 and cyclooxygenase 2, and from this study, it appears to induce mobilisation of AA from the inner cell membrane EPG and SPG. Hence, eicosanoids generated from the released AA may play a role in clinical improvements which occur in HU-treated patients.

APA, Harvard, Vancouver, ISO, and other styles

45

Efstathiou, E., P. Troncoso, S. Wen, K. Do, C. A. Pettaway, and C. J. Logothetis. "Coordinated modulation of sonic hedgehog (Shh) signaling and androgen receptor (AR) in the prostate tumor microenvironment by chemo-hormonal therapy." Journal of Clinical Oncology 25, no. 18_suppl (June 20, 2007): 5066. http://dx.doi.org/10.1200/jco.2007.25.18_suppl.5066.

Full text

Abstract:

5066 Background: Shh and androgen signaling are implicated experimentally in prostate development, regeneration and neoplastic progression. We assessed expression of components of these pathways in pretreated and control high risk prostate cancers (PCa) in a hypothesis generating search for an association with resistance to therapy. Methods: Sixty-four men with high risk PCa were randomized to receive either complete androgen ablation (AA) or AA and ketoconazole, adriamycin, vinblastine and estramustine (KAVE) for 16 weeks followed by radical prostatectomy (RP). We constructed 3 tissue microarrays from RP specimens of: a) (AA) 26 men pretreated with AA, b) (CH) 27 men pretreated with AA + KAVE and c) (Control) 26 untreated men matched for clinical stage, biopsy Gleason Score and PSA. A total of 3,178 cores were obtained [median cores: 36 (range 18–90), median blocks: 5 (range 3–9) per specimen]. Immunohistochemical expression of Shh pathway components (Shh, patched, smoothened, gli2) and AR were assessed in the tumor epithelium and stroma and recorded as percentage of cells exhibiting staining. A mixed model was used for fitting the correlated data (multiple observations from a subject). Pearson’s correlations between biomarkers were calculated based on mean expression. Results: Shh signaling, as indicated by mean expression (standard deviation) of nuclear gli2, was observed in the residual tumor epithelium [AA: 79.9 (17.4), CH: 85.7 (12.2)] and adjacent stroma [ AA: 43 (18.2),CH: 53 (16.4)] following treatment, in parallel (0.78 by Pearson’s correlation), and higher than in untreated control tumor epithelium [39.9 (20.6)] and stroma [22.9 (15.2)] (P<.0001). Smoothened and Shh were expressed accordingly. AR expression was lower in the treated tumor epithelium [AA: 47.3 (20.8), CH: 46.8 (21.1)] (P<.0001), with a trend toward increased stromal AR [AA: 8.6 (10.4), CH: 10.5 (8.2)] compared to control tumor epithelium [60.1 (24.1)] and stroma [6.4 (11.7)]. Conclusions: Shh and androgen pathways are modulated in a manner that suggests they behave in a compensatory fashion, and are determinants of response to therapy. These data support the hypothesis that the tumor microenvironment is implicated in PCa therapy resistance. No significant financial relationships to disclose.

APA, Harvard, Vancouver, ISO, and other styles

46

Sudan, Sarabjeet Kour, Kunwar Somesh Vikramdeo, Amod Sharma, Sachin Kumar Deshmukh, Sanjeev Kumar Srivastava, Teja Poosarla, Nicolette P. Holliday, Donna L. Dyess, Ajay P. Singh, and Seema Singh. "Abstract 2212: Racially disparate serum levels of inflammatory cytokines, satiety and stress hormones, and exosomal microRNAs in women with or without a breast cancer diagnosis." Cancer Research 82, no. 12_Supplement (June 15, 2022): 2212. http://dx.doi.org/10.1158/1538-7445.am2022-2212.

Full text

Abstract:

Abstract Breast cancer (BC) is the most common non-cutaneous malignancy and the second leading cause of cancer-related death in American women. Health disparities in incidence and clinical outcome are also reported among different racial groups, most notably African American (AA) women, who are often diagnosed at a young age with aggressive BC and exhibit greater mortality than Caucasian American (CA) women. Since socioeconomic difficulties can have tremendous impact on psychophysiology besides limiting the access to optimal healthcare, we examined the serum levels of stress (cortisol) and satiety (leptin) hormones as well as inflammatory cytokines (resistin and interleukin-6/IL-6) in AA and CA women. To observe a potential epigenomic connection, we also performed profiling of a targeted set of exosomal microRNAs in serum samples. The study was conducted under an Institutional Review Board (IRB) approved protocol. All subjects participated voluntarily, and their consents were obtained. Serum levels of resistin, IL-6, leptin, and cortisol were quantified by Enzyme linked Immunosorbent Assay (ELISA) using commercial kits. Exosomes were isolated using precipitation method and recovered by standard centrifugation. Total RNA was isolated from exosomal preps and subjected to stem-loop RT-PCR for quantitation of a set of inflammation-associated microRNAs. We found that the levels of resistin, leptin, IL-6 and cortisol were higher in women with a BC diagnosis than non-BC subjects. Moreover, AA women with or without BC showed significantly higher levels of these cytokines and hormones in their serum as compared to the CA women with or without a BC diagnosis, respectively. We also observed differential expression of several microRNAs in serum of BC women as compared to their normal counterparts, of which five (miR511, miR33a, miR27a, miR6794, miR143-3p) exhibited highest presence in serum exosomes of AA women with BC. Together, these findings suggest that relatively greater exposure of minority women to social stressors may have epigenomic consequences and may potentially be linked to the observed BC racial health disparities. Citation Format: Sarabjeet Kour Sudan, Kunwar Somesh Vikramdeo, Amod Sharma, Sachin Kumar Deshmukh, Sanjeev Kumar Srivastava, Teja Poosarla, Nicolette P. Holliday, Donna L. Dyess, Ajay P. Singh, Seema Singh. Racially disparate serum levels of inflammatory cytokines, satiety and stress hormones, and exosomal microRNAs in women with or without a breast cancer diagnosis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2212.

APA, Harvard, Vancouver, ISO, and other styles

47

Wesołowski, Andrzej, and Andrzej Woźniak. "Present and potential weed infestation of spring cereals in different cropping system." Acta Agrobotanica 54, no. 1 (2013): 175–90. http://dx.doi.org/10.5586/aa.2001.015.

Full text

Abstract:

This paper presents the results of investigations on the weed infestation and vertical distribution of weed seed bank in rendzina under spring cereals cultivation in crop rotations and monoculture. Used herbicides (MCPA and <i>fenoxaprop-P-etylu</i>) decreased the number of weeds and species composition in comparison with harrowing. In the soil layer of 0-25 cm used in the monoculture there was found about 22,9% weed seeds more than in crop rotation. In the canopy of spring cereals the following weeds dominated: in crop rotation - <i>Chenopodium album, Echinochloa crus-galli and Veronica persica; and in monoculture - Stellaria media, Galium aparine</i> and <i>Chenopodium album</i>. In the soil layer of 0-25 cm used in crop rotation and monoculture the following weed seeds dominated : <i>Amaranthus retroflexus, Chenopodium album</i> and <i>Stellaria media</i>.

APA, Harvard, Vancouver, ISO, and other styles

48

Falke, Dörte, Marco Fischer, Christian Ihling, Claudia Hammerschmidt, Andrea Sinz, and Gary Sawers. "Co‐purification of nitrate reductase 1 with components of the cytochrome bcc‐aa 3 oxidase supercomplex from spores of Streptomyces coelicolor A3(2)." FEBS Open Bio 11, no. 3 (February 14, 2021): 652–69. http://dx.doi.org/10.1002/2211-5463.13086.

Full text

APA, Harvard, Vancouver, ISO, and other styles

49

Mayer, Miriam, Adolf Ellinger, Anneliese Karwan, Rolf Schulte-Hermann, and Wilfried Bursch. "Cancer and nutrition: role of amino acids (AA) for the regulation of hepatocellular apoptosis." BMC Pharmacology 7, Suppl 2 (2007): A64. http://dx.doi.org/10.1186/1471-2210-7-s2-a64.

Full text

APA, Harvard, Vancouver, ISO, and other styles

50

Sathe, Claire, Melissa Kate Accordino, David DeStephano, Mansi Shah, Jason Dennis Wright, and Dawn L. Hershman. "Disparities in PI3K/mTOR inhibitor use, toxicities, and outcomes among patients with metastatic breast cancer." Journal of Clinical Oncology 41, no. 16_suppl (June 1, 2023): 6597. http://dx.doi.org/10.1200/jco.2023.41.16_suppl.6597.

Full text

Abstract:

6597 Background: Advances in breast cancer treatment have led to improvements in survival among patients with metastatic breast cancer (MBC). Nevertheless, Black patients and patients with lower socioeconomic status (SES) continue to bear a disproportionate mortality burden. Furthermore, because landmark trials for novel anticancer agents lacked racial diversity, their toxicity profile for minority patients remains uncertain. Our study examines the impact of race and other sociodemographic characteristics in the use and toxicity outcomes of PI3K and mTOR inhibitors (PI3K/mTORi). Methods: We conducted a retrospective analysis of EHR-derived data from the Flatiron Health Database (FHD). A dataset was constructed to include patients with hormone receptor-positive, HER2-negative MBC diagnosed between 1/1/2011 and 1/31/2022. Outcomes included PI3K/mTORi use, rates of hyperglycemia and dose reduction, and time on treatment. Multivariable logistic regression was used to evaluate factors associated with use and outcomes. Results: A total of 13,388 patients with MBC were included in our analysis, of which 2,620 (19.6%) received PI3K/mTORi (78.3% everolimus, 14.7% alpelisib, 6.9% both agents). Overall, 67.5% of all patients were categorized as White, 9.8% as Black/African-American (Black/AA); 18.9% were >75 years old; 10.1% were treated at an academic site; 4.0% had Medicaid insurance. Insurance through Medicaid was associated with lower use of PI3K/mTORi compared to commercial insurance (15.6% vs 18.8%; OR: 0.76, 95% CI: 0.59-0.99, p=0.04), as was advanced age (10.9% for >75 years old vs 22.9% for <60 years old; OR: 0.68, 95% CI: 0.58-0.80, p<0.001) and poorer performance status at diagnosis (15.1% for ECOG ≥2+ vs 22.9% for ECOG 0; OR: 0.84, CI: 0.72-0.98, p=0.03). Odds of PI3K/mTORi use were almost 50% higher for patients treated at an academic center (OR: 1.46, CI: 1.06-2.05, p=0.02). While Black/AA patient had lower rates of use than White patients (17.4% vs 20.1%), they had similar odds of receiving PI3K/mTORi on multivariable analysis (OR: 1.00, CI: 0.85-1.17, p>0.9). Black/AA patients experienced higher rates of hyperglycemia on PI3K/mTORi than White patients (67.6% vs 52.5%). On multivariable analysis, odds of hyperglycemia were twice as high for Black/AA patients (OR: 2.1, CI: 1.33-3.35, p<0.01). However, rates of dose reductions and time on PI3K/mTORi therapy did not differ significantly among White vs Black/AA patients. Conclusions: This analysis of real-world data suggests that lower SES is associated with decreased PI3K/mTORi use. Efforts to improve access to these life-prolonging agents are warranted. Of concern, we also found racial disparities in toxicity outcomes, with Black patients having twice the risk of hyperglycemia. Greater attention to the tolerability of novel agents in diverse populations is warranted.

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!