-
1دورية أكاديمية
المؤلفون: Ainsley C J Smith, Justin J Tse, Tadiwa H Waungana, Kirsten N Bott, Michael T Kuczynski, Andrew S Michalski, Steven K Boyd, Sarah L Manske
المصدر: PLoS ONE, Vol 17, Iss 10, p e0273203 (2022)
الوصف: IntroductionMuscle weakness can lead to reduced physical function and quality of life. Computed tomography (CT) can be used to assess muscle health through measures of muscle cross-sectional area and density loss associated with fat infiltration. However, there are limited opportunities to measure muscle density in clinically acquired CT scans because a density calibration phantom, allowing for the conversion of CT Hounsfield units into density, is typically not included within the field-of-view. For bone density analysis, internal density calibration methods use regions of interest within the scan field-of-view to derive the relationship between Hounsfield units and bone density, but these methods have yet to be adapted for muscle density analysis. The objective of this study was to design and validate a CT internal calibration method for muscle density analysis.MethodologyWe CT scanned 10 bovine muscle samples using two scan protocols and five scan positions within the scanner bore. The scans were calibrated using internal calibration and a reference phantom. We tested combinations of internal calibration regions of interest (e.g., air, blood, bone, muscle, adipose).ResultsWe found that the internal calibration method using two regions of interest, air and adipose or blood, yielded accurate muscle density values (< 1% error) when compared with the reference phantom. The muscle density values derived from the internal and reference phantom calibration methods were highly correlated (R2 > 0.99). The coefficient of variation for muscle density across two scan protocols and five scan positions was significantly lower for internal calibration (mean = 0.33%) than for Hounsfield units (mean = 6.52%). There was no difference between coefficient of variation for the internal calibration and reference phantom methods.ConclusionsWe have developed an internal calibration method to produce accurate and reliable muscle density measures from opportunistic computed tomography images without the need for calibration phantoms.
وصف الملف: electronic resource
العلاقة: https://doaj.org/toc/1932-6203Test
-
2دورية أكاديمية
المؤلفون: K. Wieczerzak, O. Nowicka, S. Michalski, T.E.J. Edwards, M. Jain, T. Xie, L. Pethö, X. Maeder, J. Michler
المصدر: Materials & Design, Vol 205, Iss , Pp 109710- (2021)
مصطلحات موضوعية: CoCr system, Nanocrystalline system, Materials library, Thin films, Mechanical properties, Materials of engineering and construction. Mechanics of materials, TA401-492
الوصف: Nanocrystalline (nc) alloys are stronger than their coarse-grained versions. Here, we report ultrastrong alloys, discovered via high-throughput screening of the nc CoCr33-69 materials library. The nc materials library was fabricated using magnetron co-sputtering. The alloys consist of textured, columnar structures with grain size in the nanometric regime. We found that the texture and phase composition can be tailored by changing the Cr concentration. In the investigated region of the nc CoCr system, a relatively broad spectrum of yield strength, determined via micropillar compression tests, was found ranging from 1.41 GPa up to 3.64 GPa. The remarkable strength increment was caused by a chemically- and thermally-driven phase and microstructure evolution of the system. The strongest alloys were found in the regions containing the δCoCr phase, which was considered previously as metastable. Density functional calculations revealed that the δCoCr phase is more energetically favourable in Cr-rich regions compared to single-phase simple solid solutions (HCP, BCC). Experimental results showed that the range of its occurrence is wider than previously thought, i.e. after annealing the δCoCr phase was found above 44 at. % of Cr. We demonstrate that systematic screening of materials libraries can boost the discovery of new materials with outstanding properties.
وصف الملف: electronic resource
العلاقة: http://www.sciencedirect.com/science/article/pii/S0264127521002628Test; https://doaj.org/toc/0264-1275Test
-
3
المؤلفون: John S. Heywood, Joseph S. Michalski, Braden K. McCann, Kara J. Andres, Allison R. Hall, Amber D. Hartman, Tessa C. Middleton, Amelia Chiles, Sarah E. Dewey, Cay A. Miller
المصدر: American Journal of Botany. 109:1875-1892
مصطلحات موضوعية: Acanthaceae, Reproduction, Manduca, Genetics, Animals, Pollen, Flowers, Plant Science, Bees, Pollination, Ecology, Evolution, Behavior and Systematics
الوصف: In the absence of hawkmoth pollinators, chasmogamous (CH) flowers of Ruellia humilis self-pollinate by two secondary mechanisms. Other floral visitors might exert selection on CH floral traits to restore outcrossing, but at the same time preferential predation of CH seeds generates selection to increase the allocation of resources to cleistogamous (CL) flowers.To assess the potential for an evolutionary response to these competing selection pressures, we estimated additive genetic variances (We found significantThe predicted evolutionary decrease in the number of CH flowers available for potential outcrossing, combined with the apparent preclusion of potential diurnal pollinators by the pollen-harvesting activities of sweat bees, suggest that 100% cleistogamy is the likely outcome of evolution in the absence of hawkmoths. However, rare mutations with large effects, such as delaying budbreak until after sunrise, could provide pathways for the restoration of outcrossing that are not reachable by gradual quantitative-genetic evolution.
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::74f6747e5a2a057ef9fd7445d247313aTest
https://doi.org/10.1002/ajb2.16063Test -
4دورية أكاديمية
المؤلفون: Ellen S. Michalski, Phuong H. Nguyen, Ines Gonzalez-Casanova, Son V. Nguyen, Reynaldo Martorell, Vin Tangpricha, Usha Ramakrishnan
المصدر: Journal of Clinical & Translational Endocrinology, Vol 8, Iss C, Pp 41-48 (2017)
مصطلحات موضوعية: Vitamin D, Anemia, Hemoglobin, Vietnam, Dietary intake, Diseases of the endocrine glands. Clinical endocrinology, RC648-665
الوصف: Background and objectives: Hypovitaminosis D and anemia are both prevalent in Vietnam, and low vitamin D status may be a risk factor for anemia. This study aimed to 1) describe vitamin D intake and its determinants, and 2) examine the associations of vitamin D intake and serum 25(OH)D concentrations with hemoglobin and anemia. Methods and study design: We used data from the baseline survey of a pre-conceptual micronutrient supplementation trial in women of reproductive age (WRA) in Thai Nguyen, Vietnam (N = 4961). Vitamin D intake was estimated using a semi-quantitative food frequency questionnaire (FFQ). Multivariable regression models were used for the analyses. Results: Median vitamin D intake was 0.2 µg/d (8.0 IU) [IQR: 0.4]. Age, being a farmer, food insecurity, and body mass index (BMI) were inversely associated with vitamin D intake, while socioeconomic status (SES), total energy intake, and education were positively associated with vitamin D intake. Vitamin D intake was not associated with hemoglobin concentration or anemia after adjusting for age, BMI, total energy intake, transferrin receptor, C-reactive protein, α1-acid glycoprotein, SES, occupation, education, ethnicity, and food insecurity (P = 0.56 and P = 0.65 for hemoglobin and anemia, respectively). Controlling for the same covariates, 25(OH)D
وصف الملف: electronic resource
العلاقة: http://www.sciencedirect.com/science/article/pii/S2214623717300248Test; https://doaj.org/toc/2214-6237Test
-
5
المؤلفون: Ainsley C. J. Smith, Justin J. Tse, Tadiwa H. Waungana, Kirsten N. Bott, Michael T. Kuczynski, Andrew S. Michalski, Steven K. Boyd, Sarah L. Manske
مصطلحات موضوعية: Multidisciplinary, Bone Density, Phantoms, Imaging, Muscles, Calibration, Quality of Life, Animals, Cattle, Tomography, X-Ray Computed
الوصف: Introduction Muscle weakness can lead to reduced physical function and quality of life. Computed tomography (CT) can be used to assess muscle health through measures of muscle cross-sectional area and density loss associated with fat infiltration. However, there are limited opportunities to measure muscle density in clinically acquired CT scans because a density calibration phantom, allowing for the conversion of CT Hounsfield units into density, is typically not included within the field-of-view. For bone density analysis, internal density calibration methods use regions of interest within the scan field-of-view to derive the relationship between Hounsfield units and bone density, but these methods have yet to be adapted for muscle density analysis. The objective of this study was to design and validate a CT internal calibration method for muscle density analysis. Methodology We CT scanned 10 bovine muscle samples using two scan protocols and five scan positions within the scanner bore. The scans were calibrated using internal calibration and a reference phantom. We tested combinations of internal calibration regions of interest (e.g., air, blood, bone, muscle, adipose). Results We found that the internal calibration method using two regions of interest, air and adipose or blood, yielded accurate muscle density values (< 1% error) when compared with the reference phantom. The muscle density values derived from the internal and reference phantom calibration methods were highly correlated (R2 > 0.99). The coefficient of variation for muscle density across two scan protocols and five scan positions was significantly lower for internal calibration (mean = 0.33%) than for Hounsfield units (mean = 6.52%). There was no difference between coefficient of variation for the internal calibration and reference phantom methods. Conclusions We have developed an internal calibration method to produce accurate and reliable muscle density measures from opportunistic computed tomography images without the need for calibration phantoms.
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::a66703f5039bfbc894dbcc2bff812549Test
https://doi.org/10.1101/2022.08.05.502969Test -
6
المؤلفون: Andrew S. Michalski, Lauren A Burt, Bryce A. Besler, Steven K. Boyd
المصدر: Osteoporosis International. 32:1639-1649
مصطلحات موضوعية: 0301 basic medicine, Bone mineral, medicine.medical_specialty, business.industry, Endocrinology, Diabetes and Metabolism, Osteoporosis, 030209 endocrinology & metabolism, Bone fracture, medicine.disease, Rheumatology, Vertebra, 03 medical and health sciences, 0302 clinical medicine, medicine.anatomical_structure, Internal medicine, Orthopedic surgery, Cohort, medicine, Fracture (geology), 030101 anatomy & morphology, Radiology, business
الوصف: Millions of CT scans are performed annually and could be also used to opportunistically assess musculoskeletal health; however, it is unknown how well this secondary assessment relates to osteoporotic fracture. This study demonstrates that opportunistic CT screening is a promising tool to predict individuals with previous osteoporotic fracture. Opportunistic computed tomography (oCT) screening for osteoporosis and fracture risk determination complements current dual X-ray absorptiometry (DXA) diagnosis. This study determined major osteoporotic fracture prediction by oCT at the spine and hip from abdominal CT scans. Initial 1158 clinical abdominal CT scans were identified from administrative databases and were the basis to generate a cohort of 490 men and women with suitable abdominal CT scans. Participant CT scans met the following criteria: over 50 years of age, the scan had no image artifacts, and the field-of-view included the L4 vertebra and proximal femur. A total of 123 participants were identified as having previously suffered a fracture within 5 years of CT scan date. Fracture cause was identified from clinical data and used to create a low-energy fracture sub-cohort. At each skeletal site, bone mineral density (BMD) and finite element (FE)-estimated bone strength were determined. Logistic regression predicted fracture and receiver-operator characteristic curves analyzed prediction capabilities. In participants with a fracture, low-energy fractures occurred in 88% of women and 79% of men. Fracture prediction by combining both BMD and FE-estimated bone strength was not statistically different than using either BMD or FE-estimated bone strength alone. Predicting low-energy fractures in women determined the greatest AUC of 0.710 by using both BMD and FE-estimated bone strength. oCT screening using abdominal CT scans is effective at predicting individuals with previous fracture at major osteoporotic sites and offers a promising screening tool for skeletal health assessment.
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::82adf3684f223f4ab239cf18709c67abTest
https://doi.org/10.1007/s00198-021-05863-0Test -
7دورية أكاديمية
المؤلفون: Leah R Reznikov, David K Meyerholz, Ryan J Adam, Mahmoud Abou Alaiwa, Omar Jaffer, Andrew S Michalski, Linda S Powers, Margaret P Price, David A Stoltz, Michael J Welsh
المصدر: PLoS ONE, Vol 11, Iss 11, p e0166089 (2016)
الوصف: Neurons innervating the airways contribute to airway hyperreactivity (AHR), a hallmark feature of asthma. Several observations suggested that acid-sensing ion channels (ASICs), neuronal cation channels activated by protons, might contribute to AHR. For example, ASICs are found in vagal sensory neurons that innervate airways, and asthmatic airways can become acidic. Moreover, airway acidification activates ASIC currents and depolarizes neurons innervating airways. We found ASIC1a protein in vagal ganglia neurons, but not airway epithelium or smooth muscle. We induced AHR by sensitizing mice to ovalbumin and found that ASIC1a-/- mice failed to exhibit AHR despite a robust inflammatory response. Loss of ASIC1a also decreased bronchoalveolar lavage fluid levels of substance P, a sensory neuropeptide secreted from vagal sensory neurons that contributes to AHR. These findings suggest that ASIC1a is an important mediator of AHR and raise the possibility that inhibiting ASIC channels might be beneficial in asthma.
وصف الملف: electronic resource
العلاقة: http://europepmc.org/articles/PMC5098826?pdf=renderTest; https://doaj.org/toc/1932-6203Test
-
8
المؤلفون: Manish Jain, Thomas Edward James Edwards, Xavier Maeder, S. Michalski, K. Wieczerzak, Laszlo Pethö, Johann Michler, Tianle Xie, O. Nowicka
المصدر: Materials & Design, Vol 205, Iss, Pp 109710-(2021)
مصطلحات موضوعية: Materials science, Annealing (metallurgy), Thin films, Mechanical properties, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, CoCr system, Phase (matter), General Materials Science, Texture (crystalline), Nanocrystalline system, Materials of engineering and construction. Mechanics of materials, Materials library, Mechanical Engineering, 021001 nanoscience & nanotechnology, Microstructure, Nanocrystalline material, Grain size, 0104 chemical sciences, Mechanics of Materials, Chemical physics, Cavity magnetron, TA401-492, 0210 nano-technology, Solid solution
الوصف: Nanocrystalline (nc) alloys are stronger than their coarse-grained versions. Here, we report ultrastrong alloys, discovered via high-throughput screening of the nc CoCr33-69 materials library. The nc materials library was fabricated using magnetron co-sputtering. The alloys consist of textured, columnar structures with grain size in the nanometric regime. We found that the texture and phase composition can be tailored by changing the Cr concentration. In the investigated region of the nc CoCr system, a relatively broad spectrum of yield strength, determined via micropillar compression tests, was found ranging from 1.41 GPa up to 3.64 GPa. The remarkable strength increment was caused by a chemically- and thermally-driven phase and microstructure evolution of the system. The strongest alloys were found in the regions containing the δCoCr phase, which was considered previously as metastable. Density functional calculations revealed that the δCoCr phase is more energetically favourable in Cr-rich regions compared to single-phase simple solid solutions (HCP, BCC). Experimental results showed that the range of its occurrence is wider than previously thought, i.e. after annealing the δCoCr phase was found above 44 at. % of Cr. We demonstrate that systematic screening of materials libraries can boost the discovery of new materials with outstanding properties.
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::ce7cb07c019073af3faf62662cda5ce5Test
http://www.sciencedirect.com/science/article/pii/S0264127521002628Test -
9
المؤلفون: Shreyasee Amin, Joyce H. Keyak, Steven K. Boyd, Daniel P. Nicolella, Thomas Lang, Andrew S. Michalski, Jean D. Sibonga, Angela M. Cheung, Eric S. Orwoll, Dianna D. Cody
المصدر: npj Microgravity, Vol 5, Iss 1, Pp 1-10 (2019)
NPJ Microgravity
Michalski, Andrew S; Amin, Shreyasee; Cheung, Angela M; Cody, Dianna D; Keyak, Joyce H; Lang, Thomas F; et al.(2019). Hip load capacity cut-points for Astronaut Skeletal Health NASA Finite Element Strength Task Group Recommendations.. NPJ microgravity, 5(1), 6. doi: 10.1038/s41526-019-0066-3. UC Irvine: Retrieved from: http://www.escholarship.org/uc/item/80n0f16cTestمصطلحات موضوعية: musculoskeletal diseases, medicine.medical_specialty, Percentile, Physics and Astronomy (miscellaneous), Materials Science (miscellaneous), lcsh:Biotechnology, Medicine (miscellaneous), 030209 endocrinology & metabolism, Biochemistry, Genetics and Molecular Biology (miscellaneous), Article, lcsh:Physiology, 03 medical and health sciences, 0302 clinical medicine, lcsh:TP248.13-248.65, medicine, 030304 developmental biology, Bone mineral, 0303 health sciences, Hip fracture, Load capacity, Task group, lcsh:QP1-981, business.industry, medicine.disease, Agricultural and Biological Sciences (miscellaneous), medicine.anatomical_structure, Space and Planetary Science, Hip bone, Cohort, Physical therapy, business
الوصف: Concerns raised at a 2010 Bone Summit held for National Aeronautics and Space Administration Johnson Space Center led experts in finite element (FE) modeling for hip fracture prediction to propose including hip load capacity in the standards for astronaut skeletal health. The current standards for bone are based upon areal bone mineral density (aBMD) measurements by dual X-ray absorptiometry (DXA) and an adaptation of aBMD cut-points for fragility fractures. Task Group members recommended (i) a minimum permissible outcome limit (POL) for post-mission hip bone load capacity, (ii) use of FE hip load capacity to further screen applicants to astronaut corps, (iii) a minimum pre-flight standard for a second long-duration mission, and (iv) a method for assessing which post-mission physical activities might increase an astronaut’s risk for fracture after return. QCT-FE models of eight astronaut were analyzed using nonlinear single-limb stance (NLS) and posterolateral fall (NLF) loading configurations. QCT data from the Age Gene/Environment Susceptibility (AGES) Reykjavik cohort and the Rochester Epidemiology Project were analyzed using identical modeling procedures. The 75th percentile of NLS hip load capacity for fractured elderly males of the AGES cohort (9537N) was selected as a post-mission POL. The NLF model, in combination with a Probabilistic Risk Assessment tool, was used to assess the likelihood of exceeding the hip load capacity during post-flight activities. There was no recommendation to replace the current DXA-based standards. However, FE estimation of hip load capacity appeared more meaningful for younger, physically active astronauts and was recommended to supplement aBMD cut-points.
وصف الملف: application/pdf
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::372deeb242f89e3a40d33bfd03252abbTest
http://link.springer.com/article/10.1038/s41526-019-0066-3Test -
10دورية أكاديمية
المؤلفون: Ryszard S. Michalski, Janusz Wojtusiak, S. Michalski
المساهمون: The Pennsylvania State University CiteSeerX Archives
مصطلحات موضوعية: Machine learning, Concept learning, Rule learning, Pattern discovery, AQ learning, Meta-values, Missing values, Irrelevant values, Not applicable values
الوصف: Title: Reasoning with missing, not-applicable and irrelevant meta-values
وصف الملف: application/pdf
النص الكامل