Calibration and Optimization of 3D Digital Breast Tomosynthesis Guided Near Infrared Spectral Tomography

Calibration of a three-dimensional multimodal digital breast tomosynthesis (DBT) x-ray and non-fiber based near infrared spectral tomography (NIRST) system is challenging but essential for clinical studies. Phantom imaging results yielded linear contrast recovery of total hemoglobin (HbT) concentration for cylindrical inclusions of 15 mm, 10 mm and 7 mm with a 3.5% decrease in the HbT estimate for each 1 cm increase in inclusion depth. A clinical exam of a patient\u27s breast containing both benign and malignant lesions was successfully imaged, with greater HbT was found in the malignancy relative to the benign abnormality and fibroglandular regions (11 μM vs. 9.5 μM). Tools developed improved imaging system characterization and optimization of signal quality, which will ultimately improve patient selection and subsequent clinical trial results

Secondary infection with Streptococcus suis serotype 7 increases the virulence of highly pathogenic porcine reproductive and respiratory syndrome virus in pigs

<p>Abstract</p> <p>Background</p> <p>Porcine reproductive and respiratory syndrome virus (PRRSV) and <it>Streptococcus suis </it>are common pathogens in pigs. In samples collected during the porcine high fever syndrome (PHFS) outbreak in many parts of China, PRRSV and <it>S. suis </it>serotype 7 (SS7) have always been isolated together. To determine whether PRRSV-SS7 coinfection was the cause of the PHFS outbreak, we evaluated the pathogenicity of PRRSV and/or SS7 in a pig model of single and mixed infection.</p> <p>Results</p> <p>Respiratory disease, diarrhea, and anorexia were observed in all infected pigs. Signs of central nervous system (CNS) disease were observed in the highly pathogenic PRRSV (HP-PRRSV)-infected pigs (4/12) and the coinfected pigs (8/10); however, the symptoms of the coinfected pigs were clearly more severe than those of the HP-PRRSV-infected pigs. The mortality rate was significantly higher in the coinfected pigs (8/10) than in the HP-PRRSV- (2/12) and SS7-infected pigs (0/10). The deceased pigs of the coinfected group had symptoms typical of PHFS, such as high fever, anorexia, and red coloration of the ears and the body. The isolation rates of HP-PRRSV and SS7 were higher and the lesion severity was greater in the coinfected pigs than in monoinfected pigs.</p> <p>Conclusion</p> <p>HP-PRRSV infection increased susceptibility to SS7 infection, and coinfection of HP-PRRSV with SS7 significantly increased the pathogenicity of SS7 to pigs.</p

Actively implementing an evidence-based feeding guideline for critically ill patients (NEED): a multicenter, cluster-randomized, controlled trial

Background: Previous cluster-randomized controlled trials evaluating the impact of implementing evidence-based guidelines for nutrition therapy in critical illness do not consistently demonstrate patient benefits. A large-scale, sufficiently powered study is therefore warranted to ascertain the effects of guideline implementation on patient-centered outcomes. Methods: We conducted a multicenter, cluster-randomized, parallel-controlled trial in intensive care units (ICUs) across China. We developed an evidence-based feeding guideline. ICUs randomly allocated to the guideline group formed a local "intervention team", which actively implemented the guideline using standardized educational materials, a graphical feeding protocol, and live online education outreach meetings conducted by members of the study management committee. ICUs assigned to the control group remained unaware of the guideline content. All ICUs enrolled patients who were expected to stay in the ICU longer than seven days. The primary outcome was all-cause mortality within 28 days of enrollment. Results: Forty-eight ICUs were randomized to the guideline group and 49 to the control group. From March 2018 to July 2019, the guideline ICUs enrolled 1399 patients, and the control ICUs enrolled 1373 patients. Implementation of the guideline resulted in significantly earlier EN initiation (1.20 vs. 1.55 mean days to initiation of EN; difference − 0.40 [95% CI − 0.71 to − 0.09]; P = 0.01) and delayed PN initiation (1.29 vs. 0.80 mean days to start of PN; difference 1.06 [95% CI 0.44 to 1.67]; P = 0.001). There was no significant difference in 28-day mortality (14.2% vs. 15.2%; difference − 1.6% [95% CI − 4.3% to 1.2%]; P = 0.42) between groups. Conclusions: In this large-scale, multicenter trial, active implementation of an evidence-based feeding guideline reduced the time to commencement of EN and overall PN use but did not translate to a reduction in mortality from critical illness. Trial registration: ISRCTN, ISRCTN12233792. Registered November 20th, 2017

Actively implementing an evidence-based feeding guideline for critically ill patients (NEED): a multicenter, cluster-randomized, controlled trial.

BackgroundPrevious cluster-randomized controlled trials evaluating the impact of implementing evidence-based guidelines for nutrition therapy in critical illness do not consistently demonstrate patient benefits. A large-scale, sufficiently powered study is therefore warranted to ascertain the effects of guideline implementation on patient-centered outcomes.MethodsWe conducted a multicenter, cluster-randomized, parallel-controlled trial in intensive care units (ICUs) across China. We developed an evidence-based feeding guideline. ICUs randomly allocated to the guideline group formed a local "intervention team", which actively implemented the guideline using standardized educational materials, a graphical feeding protocol, and live online education outreach meetings conducted by members of the study management committee. ICUs assigned to the control group remained unaware of the guideline content. All ICUs enrolled patients who were expected to stay in the ICU longer than seven days. The primary outcome was all-cause mortality within 28 days of enrollment.ResultsForty-eight ICUs were randomized to the guideline group and 49 to the control group. From March 2018 to July 2019, the guideline ICUs enrolled 1399 patients, and the control ICUs enrolled 1373 patients. Implementation of the guideline resulted in significantly earlier EN initiation (1.20 vs. 1.55 mean days to initiation of EN; difference - 0.40 [95% CI - 0.71 to - 0.09]; P = 0.01) and delayed PN initiation (1.29 vs. 0.80 mean days to start of PN; difference 1.06 [95% CI 0.44 to 1.67]; P = 0.001). There was no significant difference in 28-day mortality (14.2% vs. 15.2%; difference - 1.6% [95% CI - 4.3% to 1.2%]; P = 0.42) between groups.ConclusionsIn this large-scale, multicenter trial, active implementation of an evidence-based feeding guideline reduced the time to commencement of EN and overall PN use but did not translate to a reduction in mortality from critical illness.Trial registrationISRCTN, ISRCTN12233792 . Registered November 20th, 2017

Actively implementing an evidence-based feeding guideline for critically ill patients (NEED): a multicenter, cluster-randomized, controlled trial (vol 26, 46, 2022)

BackgroundPrevious cluster-randomized controlled trials evaluating the impact of implementing evidence-based guidelines for nutrition therapy in critical illness do not consistently demonstrate patient benefits. A large-scale, sufficiently powered study is therefore warranted to ascertain the effects of guideline implementation on patient-centered outcomes.MethodsWe conducted a multicenter, cluster-randomized, parallel-controlled trial in intensive care units (ICUs) across China. We developed an evidence-based feeding guideline. ICUs randomly allocated to the guideline group formed a local "intervention team", which actively implemented the guideline using standardized educational materials, a graphical feeding protocol, and live online education outreach meetings conducted by members of the study management committee. ICUs assigned to the control group remained unaware of the guideline content. All ICUs enrolled patients who were expected to stay in the ICU longer than seven days. The primary outcome was all-cause mortality within 28 days of enrollment.ResultsForty-eight ICUs were randomized to the guideline group and 49 to the control group. From March 2018 to July 2019, the guideline ICUs enrolled 1399 patients, and the control ICUs enrolled 1373 patients. Implementation of the guideline resulted in significantly earlier EN initiation (1.20 vs. 1.55 mean days to initiation of EN; difference - 0.40 [95% CI - 0.71 to - 0.09]; P = 0.01) and delayed PN initiation (1.29 vs. 0.80 mean days to start of PN; difference 1.06 [95% CI 0.44 to 1.67]; P = 0.001). There was no significant difference in 28-day mortality (14.2% vs. 15.2%; difference - 1.6% [95% CI - 4.3% to 1.2%]; P = 0.42) between groups.ConclusionsIn this large-scale, multicenter trial, active implementation of an evidence-based feeding guideline reduced the time to commencement of EN and overall PN use but did not translate to a reduction in mortality from critical illness.Trial registrationISRCTN, ISRCTN12233792 . Registered November 20th, 2017

Exploring multidimensional PMM reform within the complex dynamics of multi level institutions and constrained agency autonomy: A case study of a public hospital in China

Since the emergence of New Public Management (NPM) and its goal of modernising public healthcare management, a significant body of management accounting literature has explored how the interplay of contextual factors as well as actors from different levels influences management accounting developments, mainly in the Western context. Building on the extant literature, this thesis aims to advance the current knowledge by using an institutional logic perspective to deconstruct the complex interests at play in shaping the performance measurement and management (PMM) of public hospitals at the social, field, organisational, and intra-organisational levels in the context of China’s public hospital management. Therefore, this thesis explores how the multidimensional performance measurement and management (PMM) reforms are shaped by the complex and dynamic interplay between multi-level institutions and the constrained autonomy of agents within Chinese public hospital setting—by adopting an Institutional Logics Perspective (ILP). Employing a case study in a tertiary hospital in the southwest of China, this thesis aims to answer three research questions: 1) How are PMM transformation and institutional complexity dynamics interrelated? 2) How do the organization respond to the institutional complexity dynamics in their environment through PMM reform? and 3) How is the intra-organisational institutionalisation of the PMM reform shaped by situated actors within the organisation? The findings of this research reveal the intricate and multifaceted affects by the coordination between the emerging managerial logic at Chinese public healthcare field and the high-level dominating state logic on shaping the field-level PMM transformation. This study highlights the fundamental influences of institutional complexity at the field level on the proactive managerial response to initiate a PMM reform, as observed in the case hospital. Additionally, the heterogeneity in departmental professional reputation, operational intricacy, and leadership paradigms potentially steers internal medical departments towards diverse reform response strategies and then culminates in internal complexity by internalising diverse departmental PMM practices. Then the inconsistency between the managerial objectives and the actual departmental practises concerning the reforms might result in a means-end decoupling of this PMM reform. The primary contribution of this study is its extension of the contextual explanation of institutional logics beyond Western public healthcare settings. Drawing on a multi-level study of a case hospital, this research presents a theoretical framework to deconstruct the pathway of the PMM reform across various internal units. This framework highlights the fundamental influences of partial autonomy on causing internal dynamics and diversity of different medical departments in their responses to and adoption of the reform. The study contends that the heterogeneity of subunits poses challenges to designing and implementing a uniform organizational reform aimed at addressing external institutional complexity dynamics. Crucially, an exclusive emphasis on addressing the multifaceted external institutional pressures, without considering subunit diversity, may lead to a 'means-end decoupling' during the reform of public organizations. Overall, this research sheds light on the complex interplay between institutional complexity, partial autonomy, and PMM reform in public hospitals, highlighting the need for nuanced approaches that recognising the diverse contexts and cultures in which such reforms are implemented. The findings have important implications for policy makers and management seeking to design and implement effective PMM reform in healthcare sectors across different cultural and institutional contexts

Quantitative dedicated cone beam breast CT imaging

In the United States, annual mammogram screening for early breast cancer detection is recommended. Such screening is known to have a significant impact on improving cancer mortality rates. However, the diagnostic function of mammogram is hampered due to their being two-dimensional projections, resulting in tissue superposition and compromised specificity and sensitivity. Dedicated cone beam breast computed tomography (CBBCT) is a recently approved diagnostic tool that produces high quality tissue-superposition-free volumetric images, demonstrating a potential to substantially improve breast cancer detection and diagnosis. Nevertheless, high scatter contamination stemming from large irradiation volume results in severe contrast lost and shading artifacts, impeding the quantitative uses of CBBCT in certain clinical tasks. Existing scatter correction methods demonstrate different drawbacks including low efficacy, dose or scan time increase, etc. In this thesis, we propose two scatter correction methods, library-based (LB) and forward-projection-based (FPB), to overcome the deficiencies while achieving high correction efficacy. In the LB method, a scatter library is precomputed via Monte Carlo simulation based on a simple breast model. Due to the relatively simple shape and composition, we find that a small library size with one input parameter of breast size is sufficient for effective scatter correction on general population. In the FPB method, we first estimate primary signals of CBBCT projections via forward projection of the segmented first-pass reconstruction. By subtracting the simulated primary projection from the raw projection, we obtain a raw scatter estimate containing both low-frequency scatter and errors. After discarding untrusted errors from the resultant raw scatter map, the final scatter is obtained via a novel Fourier-transform based local filtration algorithm. Both methods have demonstrated high correction efficacy on patient data, the LB method is superior in computational efficiency while the FPB method has better flexibility. By comparing these two proposed methods, we find that there is a large discrepancy between the scatter estimation of the two; and the FPB method tends to better preserve high spatial-resolution details than the LB method. We hypothesize that this is mainly due to the existence of off-focus radiation (OFR), which is a fundamental factor degrading the image spatial resolution. To quantitatively investigate the effect of OFR on spatial resolution, we designed an experiment to characterize the spatial resolution with and without OFR. The obtained results are consistent with the correction results using the two correction methods, therefore successfully validating our hypothesis.Ph.D

Household financial literacy: A literature analysis and review

With the continuous improvement of the financial market system and the increasing abundance of financial services, household financial literacy is increasingly important for optimizing household financial behavioral decisions and enhancing household financial well-being. In order to grasp the research progress and main content of household financial literacy, using 1,144 documents included in the "Web of Science" database from 2003 to the present (up to June 30, 2023) as the basis and CiteSpace software as the data analysis and processing tool, this study demonstrated the research field of household financial literacy through the keyword co-occurrence map and keyword clustering map of the Main topics. On the basis of further combing related literature, the study clarified the concepts, measurement methods, and influencing factors of financial literacy, as well as the role of financial literacy in influencing the financial decision-making behaviors of households in areas such as investment, credit, and entrepreneurship. Finally, it summarized and looked forward to the development of household financial literacy research

Large-angle x-ray scatter in Talbot-Lau interferometry for breast imaging

Monte Carlo simulations were used to investigate large-angle x-ray scatter at design energy of 25 keV during small field of view (9.6 cm x 5 cm) differential phase contrast imaging of the breast using Talbot-Lau interferometry. Homogenous, adipose and fibroglandular breasts of uniform thickness ranging from 2 to 8 cm encompassing the field of view were modeled. Theoretically determined transmission efficiencies of the gratings were used to validate the Monte Carlo simulations, followed by simulations to determine the x-ray scatter reaching the detector. The recorded x-ray scatter was classified into x-ray photons that underwent at least one Compton interaction (incoherent scatter) and Rayleigh interaction alone (coherent scatter) for further analysis. Monte Carlo based estimates of transmission efficiencies showed good correspondence [Formula: see text] with theoretical estimates. Scatter-to-primary ratio increased with increasing breast thickness, ranging from 0.11 to 0.22 for 2-8 cm thick adipose breasts and from 0.12 to 0.28 for 2-8 cm thick fibroglandular breasts. The analyzer grating reduced incoherent scatter by ~18% for 2 cm thick adipose breast and by ~35% for 8 cm thick fibroglandular breast. Coherent scatter was the dominant contributor to the total scatter. Coherent-to-incoherent scatter ratio ranged from 2.2 to 3.1 for 2-8 cm thick adipose breasts and from 2.7 to 3.4 for 2-8 cm thick fibroglandular breasts

Dedicated breast CT: radiation dose for circle-plus-line trajectory

PURPOSE: Dedicated breast CT prototypes used in clinical investigations utilize single circular source trajectory and cone-beam geometry with flat-panel detectors that do not satisfy data-sufficiency conditions and could lead to cone beam artifacts. Hence, this work investigated the glandular dose characteristics of a circle-plus-line trajectory that fulfills data-sufficiency conditions for image reconstruction in dedicated breast CT. METHODS: Monte Carlo-based computer simulations were performed using the GEANT4 toolkit and was validated with previously reported normalized glandular dose coefficients for one prototype breast CT system. Upon validation, Monte Carlo simulations were performed to determine the normalized glandular dose coefficients as a function of x-ray source position along the line scan. The source-to-axis of rotation distance and the source-to-detector distance were maintained constant at 65 and 100 cm, respectively, in all simulations. The ratio of the normalized glandular dose coefficient at each source position along the line scan to that for the circular scan, defined as relative normalized glandular dose coefficient (RD(g)N), was studied by varying the diameter of the breast at the chest wall, chest-wall to nipple distance, skin thickness, x-ray beam energy, and glandular fraction of the breast. RESULTS: The RD(g)N metric when stated as a function of source position along the line scan, relative to the maximum length of line scan needed for data sufficiency, was found to be minimally dependent on breast diameter, chest-wall to nipple distance, skin thickness, glandular fraction, and x-ray photon energy. This observation facilitates easy estimation of the average glandular dose of the line scan. Polynomial fit equations for computing the RD(g)N and hence the average glandular dose are provided. CONCLUSIONS: For a breast CT system that acquires 300-500 projections over 2pi for the circular scan, the addition of a line trajectory with equal source spacing and constant x-ray beam quality (kVp and HVL) and mAs matched to the circular scan, will result in less than 0.18% increase in average glandular dose to the breast per projection along the line scan