Hardware algorithm design and validation for nuclear radiation imaging based on Monte Carlo simulation.

The nuclear radiation imaging technology, aimed at illustrating the position and distribution of radioactive sources, has undergone extensive research. By relying on a simulated radiation imaging system for data acquisition, we can significantly expedite the development cycle of these imaging instruments. Establishing simulated experimental scenarios and radiation imaging systems is of paramount significance in obtaining output signals for algorithmic testing and validation. This study is divided into two parts: simulation and hardware algorithm. In the simulation part, precise simulation of scintillation light transport in a crystal was achieved using the GEANT4 Monte Carlo simulation toolkit. A LaBr3(Ce) detector system was simulated by digitizing photon interactions. In the hardware algorithm part, a positioning algorithm based on a fully connected neural network was implemented and optimized using a heterogeneous distributed storage approach. The system validated and assessed the FPGA-based neural network gamma camera positioning algorithm, demonstrating significant consistency with computer-generated images in capturing the shape and dispersion of radioactive sources (planar, multi-point, and ring-shaped).

The Feedback Loop Between the Demand for Voluntary Private Insurance and the Burden of Healthcare System: An Explanatory System Dynamics Model of Hong Kong.

BACKGROUND: Many countries with universal healthcare have a parallel private healthcare sector due to the waiting time in the public sector. People purchase individual health insurance to pay for private services. Past studies on the relationship between the public sector's waiting time and the demand for health insurance have two limitations: not considering the capacity of the private sector, and subsequently, the omission of a feedback loop. These limitations are also present in the health insurance policy discussion in Hong Kong, where the public sector is overstretched. A lack of understanding of market dynamics might lead to unrealistic expectations of public policy. This study highlights these limitations, and tries to answer the research question: whether the historical dynamics between the intersectoral imbalance of burden and the demand for health insurance in Hong Kong could be quantitatively explained. METHODS: A system dynamics model was created based on a negative feedback loop. The model's initial input was the percentage of population with health insurance in 2009, and to simulate the percentage continuously until 2019. Results from 2015 to 2019 were compared with actual figures to examine the model's explanatory power. Multivariable sensitivity analysis was performed. RESULTS: With initial fluctuation, the simulated result stabilized and was within the acceptable error range from 2015 to 2019. The mean absolute percentage error (MAPE) was 0.94%. At the end of 2019, the simulated percentage of population with health insurance is 36.6% versus the "real value" of 36.7%. Simulated patient admissions and occupancy rates also approximate the reality. Sensitivity analysis demonstrates the robustness of the model. CONCLUSION: We can quantitatively explain the feedback loop between health system burden and demand for health insurance. With local parameterization, this model should be transferable to other universal health systems for a better understanding of the system dynamics and more informed policy-making.

Airborne lead: A vital factor influencing rice lead accumulation in China.

Traditionally, lead (Pb) in rice grains has been thought to be mostly derived from soil, and the contribution of aerosol Pb remains so far unknown. Based on a meta-analysis, we surprisingly found rice Pb content decreased proportionally with urban atmospheric Pb concentrations in major rice-growing provinces in China during 2001-2015, suggestive of the strong influence of long-range Pb transport on agricultural environment. With the combination of field survey, field experiment, as well as a predictive model, we confirmed high contribution of atmospheric exposure to rice grain Pb in China. We for the first time developed a predictive mathematical model which revealed that aerosol Pb accumulation ratios of rice grains were related to both grain weight and accumulation types. We successfully predicted the national-scale rice Pb in China on the basis of the public data of urban PM2.5 from 19 rice-growing provinces and proposed a seasonal atmospheric Pb limit of 0.20 µg m-3 based on the safe threshold level of Pb in rice, which was much lower than the current limit of 1 µg m-3 set in China.

Biofertilizer-induced response to cadmium accumulation in Oryza sativa L. grains involving exogenous organic matter and soil bacterial community structure.

The accumulation of cadmium (Cd) in Oryza sativa L., the world's most significant staple crop, is a health threat to millions of people. The objective of this study was to evaluate the effectiveness of commercially available biofertilizers (with high (BF2) and low organic matter (OM) content (BF1)) on Cd accumulation in two types of soils and to determine the bacterial community responses by high-throughput sequencing. The study was conducted in the form of pot experiment in greenhouse in 2018. Four treatments were set: BF1, BF2, organic fertilizer (OF), and control (CK) and the amendments were applied before the rice cultivation. The results showed that the addition of biofertilizers immobilized or mobilized Cd in soils, depending on the soil type and the OM content in biofertilizers. The exogenous OM in biofertilizers was the driving factor for the difference in pH and Cd accumulation in rice grains. The application of biofertilizers with high OM content was effective in reducing Cd accumulation in the rice grains (19.7% lower than CK) by significantly increasing soil pH (from 6.02 to 6.67) in acid silt loam soil (TZ). The consumption of acid fermentation products by soil chemoorganotrophs and the complexation of organic anions in the biofertilizer treatment tended to buffer the pH drop in the drainage and decrease the Cd availability. However, in the weak acid silty clay loam soil (SX), the addition of biofertilizer with high OM significantly increased Cd accumulation in rice grains (21.9% higher than CK), probably owing to the release of acid substances, resulting from the significant increase of the predominant bacteria Chloroflexi. The addition of biofertilizer with low OM content did not significantly change Cd accumulation in rice grains or affect the soil microbial structures in both soils. In conclusion, the effects of biofertilizer on rice Cd accumulation were related to the OM content and soil bacterial community. Biofertilizers with high organic matter may not be suitable for amendments in the paddy soils with high clay content to reduce Cd accumulation in rice grains.

Improve the Design and Implementation of Metrics From the Perspective of Complexity Science Comment on "Gaming New Zealand's Emergency Department Target: How and Why Did It Vary Over Time and Between Organisations?"

From the perspective of complexity science, this commentary addresses Tenbensel and colleagues' study, which reveals varied gaming behaviours to meet the New Zealand Emergency Department (ED) metric. Seven complexity-informed principles previously published in this Journal are applied to formulate recommendations to improve the design and implementation of metrics. (1) Acknowledge unpredictability. When designing a metric, policy-makers need to leave room for flexibility to account for unforeseen situations. When implementing a metric, they need to promote sense-making of relevant stakeholders. (2) Sense-making shall be encouraged because it is a social process to understand a metric, align values and develop a coherent strategy. Sense-making is important to (3) cope with self-organised gaming behaviours and to (4) facilitate interdependencies between ED and other departments as well as organisations. (5) We also need to attend to the relationship between senior management and frontline staff. Additionally, to address one of the methodological weaknesses in Tenbensel and colleagues' study, (6) adaptive research approach is needed to better answer emerging questions. (7) Conflict should be harnessed productively. I hope these recommendations could limit gaming in future metrics and encourage stakeholders to view inevitable gaming as an improvement opportunity.

Self-management programmes for cirrhosis: A systematic review.

BACKGROUND AND AIMS: Liver cirrhosis severely decreases patients' quality of life. Since self-management programmes have improved quality of life and reduce hospital admissions in other chronic diseases, they have been suggested to decrease liver cirrhosis burden. METHODS: We performed a systematic review and meta-analysis to evaluate the clinical impact of self-management programmes in patients with liver cirrhosis, which followed the Preferred Reporting for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Primary outcomes include health-related quality of life (HRQOL) and hospitalisation. We searched MEDLINE, CENTRAL, Embase, CINAHL, PsycINFO and two trial registers to July 2017. RESULTS: We identified four randomised trials (299 patients) all rated at a high risk of bias. No difference was demonstrated for HRQOL (standardised mean difference -0.01, 95% CI: -0.48 to 0.46) and hospitalisation days (incidence rate ratio 1.6, 95% CI: 0.5-4.8). For secondary outcomes, one study found a statistically significant improvement in patient knowledge (mean difference (MD) 3.68, 95% CI: 2.11-5.25) while another study found an increase in model for end-stage liver disease scores (MD 2.8, 95% CI: 0.6-4.9) in the self-management group. No statistical difference was found for the other secondary outcomes (self-efficacy, psychological health outcomes, healthcare utilisation, mortality). Overall, the quality of the evidence was low. The content of self-management programmes varied across studies with little overlap. CONCLUSIONS: The current literature indicates that there is no evidence of a benefit of self-management programmes for people with cirrhosis. RELEVANCE TO CLINICAL PRACTICE: Practitioners should use self-management programmes with caution when delivering care to patients living with cirrhosis. Further research is required to determine what are the key features in a complex intervention like self-management. This review offers a preliminary framework for clinicians to develop a new self-management programme with key features of effective self-management interventions from established models.

Efficacy of population-wide diabetes and obesity prevention programs: An overview of systematic reviews on proximal, intermediate, and distal outcomes and a meta-analysis of impact on BMI.

We conducted an overview of systematic reviews and a meta-analysis of the impact on body mass index (BMI) of primary studies of population-wide obesity and diabetes prevention programs, in order to evaluate their efficacy. We searched eight databases for reviews of population-level programs reporting effect on diet, physical activity, BMI, or prevalence of obesity/overweight or type 2 diabetes mellitus (T2DM). Meta-analysis of primary studies within reviews reporting effect on BMI. Interventions were categorized using ANGELO framework and quality assessment using AMSTAR. Fifty-three systematic reviews were included. Primary studies were largely natural experiments or cross-sectional studies of national data. Increased price of sugar-sweetened beverages (SSBs) and fast food, decreased price of fruit and vegetables, food labelling, and grocery store interventions were associated with positive effects on diet. Park and playground renovations and point-of-choice prompts to increase stair use were associated with positive effects on physical activity. Increased price of SSBs, menu labelling, grocery store interventions, and multicomponent interventions were associated with small reductions in BMI. There was insufficient evidence of impact of any interventions on the prevalence of overweight, obesity, or T2DM. We have identified a promising suite of population-wide actions to improve diet, increase physical activity, and reduce BMI. Impact on subsequent incidence of T2DM remains speculative.

A Chinese practice guideline of the assisted reproductive technology strategies for women with advanced age.

More women postpone childbearing nowadays while female fertility begins to decline with advancing age. Furthermore, with the rolling out of the two-child policy, there is a huge demand for a second child for Chinese aged women. There are various assisted reproductive technology (ART) strategies applied for age-related infertility without solid evidence. On behalf of the Society of Reproductive Medicine, Chinese Medical Association, we would like to develop a Chinese guideline of ART strategies for age-related infertility. This guideline was produced following the recommendations for standard guidelines described in the 2012 WHO Handbook for guideline development. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) framework was also followed. A protocol was formulated and a Guideline Development Group was formed with specialists of reproductive medicine, methodologists from Chinese GRADE working group, and patient representative. Questions regarding the ART strategies for aged infertility were formulated and 8 most important ones were chosen to be structured in PICO format (Population, Intervention, Comparison, Outcomes). Comprehensive search and review of the literature were performed and the quality of the evidence was assessed and rated based on certain criteria and be categorized as high, moderate, low, or very low. Twenty-five recommendations were formulated among members of the Guidelines Development Group (Delphi method) basing on the overall quality of the evidence, in addition to the balance between benefits and harms, values and preferences, and resource implications. The final recommendations were agreed on by consensus during face-to-face meetings. This is the first Chinese practice guideline in reproductive medicine developed following the standard and scientific method.

The validity of synthetic clinical data: a validation study of a leading synthetic data generator (Synthea) using clinical quality measures.

BACKGROUND: Clinical data synthesis aims at generating realistic data for healthcare research, system implementation and training. It protects patient confidentiality, deepens our understanding of the complexity in healthcare, and is a promising tool for situations where real world data is difficult to obtain or unnecessary. However, its validity has not been fully examined, and no previous study has validated it from the perspective of healthcare quality, a critical aspect of a healthcare system. This study fills this gap by calculating clinical quality measures using synthetic data. METHODS: We examined an open-source well-documented synthetic data generator Synthea, which was composed of the key advancements in this emerging technique. We selected a representative 1.2-million Massachusetts patient cohort generated by Synthea. Four quality measures, Colorectal Cancer Screening, Chronic Obstructive Pulmonary Disease (COPD) 30-Day Mortality, Rate of Complications after Hip/Knee Replacement, and Controlling High Blood Pressure, were selected based on clinical significance. Calculated rates were then compared with publicly reported rates based on real-world data of Massachusetts and United States. RESULTS: Of the total Synthea Massachusetts population (n = 1,193,439), 394,476 were eligible for the "colorectal cancer screening" quality measure, and 248,433 (63%) were considered compliant, compared to the publicly reported Massachusetts and national rates being 77.3 and 69.8%, respectively. Of the 409 eligible patients, 0.7% of died within 30 days after COPD exacerbation, versus 7% reported in Massachusetts and 8% nationally. Using an expanded logic, this rate increased to 5.7%. No Synthea residents had complications after Hip/Knee Replacement (Massachusetts: 2.9%, national: 2.8%) or had their blood pressure controlled after being diagnosed with hypertension (Massachusetts: 74.52%, national: 69.7%). Results show that Synthea is quite reliable in modeling demographics and probabilities of services being offered in an average healthcare setting. However, its capabilities to model heterogeneous health outcomes post services are limited. CONCLUSIONS: Synthea and other synthetic patient generators do not currently model for deviations in care and the potential outcomes that may result from care deviations. To output a more realistic data set, we propose that synthetic data generators should consider important quality measures in their logic and model when clinicians may deviate from standard practice.

A Chinese practice guideline of the assisted reproductive technology strategies for women with advanced age

More women postpone childbearing nowadays while female fertility begins to decline with advancing age. Furthermore, with the rolling out of the two­child policy, there is a huge demand for a second child for Chinese aged women. There are various assisted reproductive technology (ART) strategies applied for age­related infertility without solid evidence. On behalf of the Society of Reproductive Medicine, Chinese Medical Association, we would like to develop a Chinese guideline of ART strategies for age­related infertility. This guideline was produced following the recommendations for standard guidelines described in the 2012 WHO Handbook for guideline development. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) framework was also followed. A protocol was formulated and a Guideline Development Group was formed with specialists of reproductive medicine, methodologists from Chinese GRADE working group, and patient representative. Questions regarding the ART strategies for aged infertility were formulated and 8 most important ones were chosen to be structured in PICO format (Population, Intervention, Comparison, Outcomes). Comprehensive search and review of the literature were performed and the quality of the evidence was assessed and rated based on certain criteria and be categorized as high, moderate, low, or very low. Twenty­five recommendations were formulated among members of the Guidelines Development Group (Delphi method) basing on the overall quality of the evidence, in addition to the balance between benefits and harms, values and preferences, and resource implications. The final recommendations were agreed on by consensus during face­to­face meetings. This is the first Chinese practice guideline in reproductive medicine developed following the standard and scientific method.

Morphine for chronic neuropathic pain in adults.

BACKGROUND: Neuropathic pain, which is caused by a lesion or disease affecting the somatosensory system, may be central or peripheral in origin. Neuropathic pain often includes symptoms such as burning or shooting sensations, abnormal sensitivity to normally painless stimuli, or an increased sensitivity to normally painful stimuli. Neuropathic pain is a common symptom in many diseases of the nervous system. Opioid drugs, including morphine, are commonly used to treat neuropathic pain. Most reviews have examined all opioids together. This review sought evidence specifically for morphine; other opioids are considered in separate reviews. OBJECTIVES: To assess the analgesic efficacy and adverse events of morphine for chronic neuropathic pain in adults. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and Embase for randomised controlled trials from inception to February 2017. We also searched the reference lists of retrieved studies and reviews, and online clinical trial registries. SELECTION CRITERIA: We included randomised, double-blind trials of two weeks' duration or longer, comparing morphine (any route of administration) with placebo or another active treatment for neuropathic pain, with participant-reported pain assessment. DATA COLLECTION AND ANALYSIS: Two review authors independently extracted data and assessed trial quality and potential bias. Primary outcomes were participants with substantial pain relief (at least 50% pain relief over baseline or very much improved on Patient Global Impression of Change scale (PGIC)), or moderate pain relief (at least 30% pain relief over baseline or much or very much improved on PGIC). Where pooled analysis was possible, we used dichotomous data to calculate risk ratio (RR) and number needed to treat for an additional beneficial outcome (NNT) or harmful outcome (NNH). We assessed the quality of the evidence using GRADE and created 'Summary of findings' tables. MAIN RESULTS: We identified five randomised, double-blind, cross-over studies with treatment periods of four to seven weeks, involving 236 participants in suitably characterised neuropathic pain; 152 (64%) participants completed all treatment periods. Oral morphine was titrated to maximum daily doses of 90 mg to 180 mg or the maximum tolerated dose, and then maintained for the remainder of the study. Participants had experienced moderate or severe neuropathic pain for at least three months. Included studies involved people with painful diabetic neuropathy, chemotherapy-induced peripheral neuropathy, postherpetic neuralgia criteria, phantom limb or postamputation pain, and lumbar radiculopathy. Exclusions were typically people with other significant comorbidity or pain from other causes.Overall, we judged the studies to be at low risk of bias, but there were concerns over small study size and the imputation method used for participants who withdrew from the studies, both of which could lead to overestimation of treatment benefits and underestimation of harm.There was insufficient or no evidence for the primary outcomes of interest for efficacy or harm. Four studies reported an approximation of moderate pain improvement (any pain-related outcome indicating some improvement) comparing morphine with placebo in different types of neuropathic pain. We pooled these data in an exploratory analysis. Moderate improvement was experienced by 63% (87/138) of participants with morphine and 36% (45/125) with placebo; the risk difference (RD) was 0.27 (95% confidence interval (CI) 0.16 to 0.38, fixed-effects analysis) and the NNT 3.7 (2.6 to 6.5). We assessed the quality of the evidence as very low because of the small number of events; available information did not provide a reliable indication of the likely effect, and the likelihood that the effect will be substantially different was very high. A similar exploratory analysis for substantial pain relief on three studies (177 participants) showed no difference between morphine and placebo.All-cause withdrawals in four studies occurred in 16% (24/152) of participants with morphine and 12% (16/137) with placebo. The RD was 0.04 (-0.04 to 0.12, random-effects analysis). Adverse events were inconsistently reported, more common with morphine than with placebo, and typical of opioids. There were two serious adverse events, one with morphine, and one with a combination of morphine and nortriptyline. No deaths were reported. These outcomes were assessed as very low quality because of the limited number of participants and events. AUTHORS' CONCLUSIONS: There was insufficient evidence to support or refute the suggestion that morphine has any efficacy in any neuropathic pain condition.