Evaluating analytical quality in clinical biochemistry laboratory using Six Sigma

Introduction: In recent years, Six Sigma metrics has become the hotspot in all trades and professions, which contributes a general procedure to explain the performance on sigma scale. Nowadays, many large companies, such as General Healthcare, Siemens, etc., have applied Six Sigma to clinical medicine and achieved satisfactory results. In this paper, we aim to evaluate the process performance of our laboratory by using Sigma metrics, thereby choosing the correct analytical quality control approach for each parameter. Materials and methods: This study was conducted in the clinical chemistry laboratory of Shandong Provincial Hospital. The five-months data of internal quality control were harvested for the parameters: amylase (AMY), lactate dehydrogenase (LD), potassium, total bilirubin (TBIL), triglyceride, aspartate aminotransferase (AST), uric acid, high density lipoprotein-cholesterol (HDL-C), alanine aminotransferase (ALT), urea, sodium, chlorine, magnesium, alkaline phosphatase (ALP), creatinine (CRE), total protein, creatine kinase (CK), total cholesterol, glucose (GLU), albumin (ALB). Sigma metrics were calculated using total allowable error, precision and percent bias for the above-mentioned parameters. Results: Sigma values of urea and sodium were below 3. Sigma values of total protein, CK, total cholesterol, GLU and ALB were in the range of 3 to 6. Sigma values of AMY, uric acid, HDL-C, TBIL, ALT, triglyceride, AST, ALP and CRE were more than 6. Conclusion: Amylase was the best performer with a Sigma metrics value of 19.93, while sodium had the least average sigma values of 2.23. Actions should be taken to improve method performance for these parameters with sigma below 3

Wide-spectrum optical synthetic aperture imaging via spatial intensity interferometry

High resolution imaging is achieved using increasingly larger apertures and successively shorter wavelengths. Optical aperture synthesis is an important high-resolution imaging technology used in astronomy. Conventional long baseline amplitude interferometry is susceptible to uncontrollable phase fluctuations, and the technical difficulty increases rapidly as the wavelength decreases. The intensity interferometry inspired by HBT experiment is essentially insensitive to phase fluctuations, but suffers from a narrow spectral bandwidth which results in a lack of effective photons. In this study, we propose optical synthetic aperture imaging based on spatial intensity interferometry. This not only realizes diffraction-limited optical aperture synthesis in a single shot, but also enables imaging with a wide spectral bandwidth, which greatly improves the optical energy efficiency of intensity interferometry. And this method is insensitive to the optical path difference between the sub-apertures. Simulations and experiments present optical aperture synthesis diffraction-limited imaging through spatial intensity interferometry in a 100 nm spectral width of visible light, whose maximum optical path difference between the sub-apertures reaches 69λ. This technique is expected to provide a solution for optical aperture synthesis over kilometer-long baselines at optical wavelengths

Income-related health inequality of migrant workers in China and its decomposition: An analysis based on the 2012 China Labor-force Dynamics Survey data

Background: Although migrant workers are a vulnerable group in China, they demonstrably contribute to the country's economic growth and prosperity. This study aimed to describe and assess the inequality of migrant worker health in China and its association with socioeconomic determinants. Methods: The data utilized in this study were obtained from the 2012 China Labor-force Dynamics Survey conducted in 29 Chinese provinces. This study converted the self-rated health of these migrant workers into a general cardinal ill-health score. Determinants associated with migrant worker health included but were not limited to age, marital status, income, and education, among other factors. Concentration index, concentration curve, and decomposition of the concentration index were employed to measure socioeconomic inequality in migrant workers' health. Results: Prorich inequality was found in the health of migrant workers. The concentration index was −0.0866, as a score indicator of ill health. Decomposition of the concentration index revealed that the factors most contributing to the observed inequality were income, followed by gender, age, marital status, and smoking history. Conclusion: It is generally known that there is an unequal socioeconomic distribution of migrant worker health in China. In order to reduce the health inequality, the government should make a substantial effort to strengthen policy implementation in improving the income distribution for vulnerable groups. After this investigation, it is apparent that the findings we have made warrant further investigation

Development of a Mix Design Method for Multiplexed Powder Self-Compacting Concrete Based on the Multiscale Rheological Threshold Theory

The multiscale rheological threshold theory can guide the mix design of self-compacting concrete (SCC) from a trans-scale view. Through the paste thresholds calculated by the mini-slump flow test results, the workability of SCC can be predicted. However, this method shows insufficient prediction accuracy when handling multiplexed powder. In the existing threshold calculation formula, the characteristics of powder materials were described through empirical values, without considering the specific properties of various powders. This paper focuses on the application of the multiscale rheological threshold theory to multiplexed powder SCCs. Through the research on the characteristics of powder materials, especially D50 and Span, the effect of the powder properties on paste thresholds was carried out. The prediction accuracies were confirmed by four sets of self-compacting mixtures at paste and concrete scales and were verified with another set of tests. There are a total of 45 paste and 45 SCC test results with multiplexed powders, including cement, fly ash, and limestone powder. The predicting accuracies are expressed as the relative accuracy ε and the accuracy index ε′, calculated by the comparison of self-compacting zones at paste and SCC scales. The calculation results showed that ε and ε′ of the modified method increased. This modified method can be efficient for the mix design of SCC containing multiplexed powders

Preliminary design and performance analysis of the liquid turbine for supercritical compressed air energy storage systems

Liquid turbines can replace throttling valves to recover waste energy and reduce vaporization in various industrial systems, such as liquefied natural gas, air separation, supercritical compressed air energy storage (SC-CAES) systems, et al. However, there were few studies about differences in the preliminary design method between general radial inflow turbines and liquid turbines. In this paper, a preliminary design method of liquid turbines was presented, and the performance of liquid turbines was predicted using CFD methods which were validated with experimental results. The efficiency of the designed liquid turbine was 92% and the output power was 65.7 kW. The performance of the turbine predicted by the preliminary method could agree with simulation results of prototype and model turbines near the design working condition, while there was a certain deviation when the flow rate was less than 70%. Through analyzing the presented preliminary design method, it could be found that distinctive differences in thermal properties of working fluids caused that typical design parameters for liquid turbines, like ratios of the blade height, the hub radius and the area, should be selected differently from empirical values for gas radial turbines. The results obtained in this paper could help guide the design of liquid turbines for various systems to promote energy conservation and improve system efficiencies significantly

Exploring the Individual Travel Patterns Utilizing Large-Scale Highway Transaction Dataset

With the spread of electronic toll collection (ETC) and electronic payment, it is still a challenging issue to develop a systematic approach to investigate highway travel patterns. This paper proposed to explore spatial–temporal travel patterns to support traffic management. Travel patterns were extracted from the highway transaction dataset, which provides a wealth of individual information. Additionally, this paper constructed the analysis framework, involving individual, and temporal and spatial attributes, on the basis of the RFM (Recency, Frequency, Monetary) model. In addition to the traditional factors, the weekday trip and repeated rate were introduced in the study. Subsequently, various models, involving K-means, Fuzzy C-means and SOM (Self-organizing Map) models, were employed to investigate travel patterns. According to the performance evaluation, the SOM model presented better performance and was utilized in the final analysis. The results indicated that six groups were categorized with a significant difference. Through further investigation, we found that the random traveler occupied over 40% of the samples, while the commuting traveler and long-range freight traveler presented relatively fixed spatial and temporal patterns. The results were also meaningful for highway authority management. The discussion and implication of travel patterns to be integrated with the dynamic pricing strategy were also discussed

Tip leakage flow analysis of an axial turbine under the effect of separation at low Reynolds number

The tip clearance flow could lead to work reduction and loss generation in turbomachines. However, the effect of separation at low Reynolds number on leakage flow is seldom studied. The previous method for evaluating tip leakage characteristics should also be further researched. Thus, numerical investigations on the tip clearance flow in an unshrouded axial-inflow turbine are conducted at low Reynolds number (3.5 x 10(4) of the rotor outlet at the designed condition) in the present study. The flow patterns and leakage mass flow rate of the clearance have been analyzed in detail. It is found that the tip clearance flow is greatly affected by the flow separation caused by low Reynolds number. The scraping ratio adopted in previous references does not accord with the clearance flow characteristics at low Reynolds number, especially in the front part of the clearance. A coefficient by -0.70 power of the Reynolds number is proposed to modify the scraping ratio in the present study. The synergy between the velocity and the pressure gradient is innovatively employed to research the tip clearance flow characteristics, and it gives a reliable criterion of indicating the flow patterns in the tip clearance

Exploring the Individual Travel Patterns Utilizing Large-Scale Highway Transaction Dataset

With the spread of electronic toll collection (ETC) and electronic payment, it is still a challenging issue to develop a systematic approach to investigate highway travel patterns. This paper proposed to explore spatial–temporal travel patterns to support traffic management. Travel patterns were extracted from the highway transaction dataset, which provides a wealth of individual information. Additionally, this paper constructed the analysis framework, involving individual, and temporal and spatial attributes, on the basis of the RFM (Recency, Frequency, Monetary) model. In addition to the traditional factors, the weekday trip and repeated rate were introduced in the study. Subsequently, various models, involving K-means, Fuzzy C-means and SOM (Self-organizing Map) models, were employed to investigate travel patterns. According to the performance evaluation, the SOM model presented better performance and was utilized in the final analysis. The results indicated that six groups were categorized with a significant difference. Through further investigation, we found that the random traveler occupied over 40% of the samples, while the commuting traveler and long-range freight traveler presented relatively fixed spatial and temporal patterns. The results were also meaningful for highway authority management. The discussion and implication of travel patterns to be integrated with the dynamic pricing strategy were also discussed