MRI non-rigid registration with tumor contraction correction for ablative margin assessment after microwave ablation of hepatocellular carcinomas.

Objective. This study aims to develop and assess a tumor contraction model, enhancing the precision of ablative margin (AM) evaluation after microwave ablation (MWA) treatment for hepatocellular carcinomas (HCCs).Approach. We utilize a probabilistic method called the coherent point drift algorithm to align pre-and post-ablation MRI images. Subsequently, a nonlinear regression method quantifies local tumor contraction induced by MWA, utilizing data from 47 HCC with viable ablated tumors in post-ablation MRI. After automatic non-rigid registration, correction for tumor contraction involves contracting the 3D contour of the warped tumor towards its center in all orientations.Main results. We evaluate the performance of our proposed method on 30 HCC patients who underwent MWA. The Dice similarity coefficient between the post-ablation liver and the warped pre-ablation livers is found to be 0.95 ± 0.01, with a mean corresponding distance between the corresponding landmarks measured at 3.25 ± 0.62 mm. Additionally, we conduct a comparative analysis of clinical outcomes assessed through MRI over a 3 month follow-up period, noting that the AM, as evaluated by our proposed method, accurately detects residual tumor after MWA.Significance. Our proposed method showcases a high level of accuracy in MRI liver registration and AM assessment following ablation treatment. It introduces a potentially approach for predicting incomplete ablations and gauging treatment success.

Non-intrusive speech quality assessment with attention-based ResNet-BiLSTM.

Speech quality is frequently affected by a variety factors in online conferencing applications, such as background noise, reverberation, packet loss and network jitter. In real scenarios, it is impossible to obtain a clean reference signal for evaluating the quality of the conferencing speech. Therefore, an effective non-intrusive speech quality assessment (NISQA) method is necessary. In this paper, we propose a new network framework for NISQA based on ResNet and BiLSTM. ResNet is utilized to extract local features, while BiLSTM is used to integrate representative features with long-term time dependencies and sequential characteristics. Considering that ResNet may result in the loss of context information when applied to the NISQA task, we propose a variant of ResNet which can preserve the time series information of the conferencing speech. The experimental results demonstrate that the proposed method has a high correlation with the mean opinion score of clean, noisy and processed speech.

Quantitative signal quality assessment for large-scale continuous scalp electroencephalography from a big data perspective.

Objective. Despite electroencephalography (EEG) being a widely used neuroimaging technique with an excellent temporal resolution, in practice, the signals are heavily contaminated by artifacts masking responses of interest in an experiment. It is thus essential to guarantee a prompt and effective detection of artifacts that provides quantitative quality assessment (QA) on raw EEG data. This type of pipeline is crucial for large-scale EEG studies. However, current EEG QA studies are still limited.Approach. In this study, combined from a big data perspective, we therefore describe a quantitative signal quality assessment pipeline, a stable and general threshold-based QA pipeline that automatically integrates artifact detection and new QA measures to assess continuous resting-state raw EEG data. One simulation dataset and two resting-state EEG datasets from 42 healthy subjects and 983 clinical patients were utilized to calibrate the QA pipeline.Main Results. The results demonstrate that (1) the QA indices selected are sensitive: they almost strictly and linearly decrease as the noise level increases; (2) stable, replicable QA thresholds are valid for other experimental and clinical EEG datasets; and (3) use of the QA pipeline on these datasets reveals that high-frequency noises are the most common noises in EEG practice. The QA pipeline is also deployed in the WeBrain cloud platform (https://webrain.uestc.edu.cn/, the Chinese EEG Brain Consortium portal).Significance. These findings suggest that the proposed QA pipeline may be a stable and promising approach for quantitative EEG signal quality assessment in large-scale EEG studies.

Label-reconstruction-based pseudo-subscore learning for action quality assessment in sporting events.

Most existing action quality assessment (AQA) methods provide only an overall quality score for the input video and lack an evaluation of each substage of the movement process; thus, these methods cannot provide detailed feedback for users. Moreover, the existing datasets do not provide labels for substage quality assessment. To address these problems, in this work, a new label-reconstruction-based pseudo-subscore learning (PSL) method is proposed for AQA in sporting events. In the proposed method, the overall score of an action is not only regarded as a quality label but also used as a feature of the training set. A label-reconstruction-based learning algorithm is built to generate pseudo-subscore labels for the training set. Moreover, based on the pseudo-subscore labels and overall score labels, a multi-substage AQA model is fine-tuned from the PSL model to predict the action quality score of each substage and the overall score for an athlete. Several ablation experiments are performed to verify the effectiveness of each module. The experimental results show that our approach achieves state-of-the-art performance.

CO2 Emissions Inventory and Its Uncertainty Analysis of China's Industrial Parks: A Case Study of the Maanshan Economic and Technological Development Area.

The Chinese government has pledged to peak carbon emissions by 2030 and achieve carbon neutrality by 2060. Industrial parks are the key to achieving the carbon peak and neutrality in industrial sectors. Establishing the CO2 emissions inventory is the first step to achieve the carbon peak in industrial parks. In this study, a comprehensive CO2 emissions inventory was established for industrial parks, including three parts: energy consumption, industrial process, and waste disposal. We considered scope 1, 2, and 3 emissions and established an uncertainty analysis framework. Accordingly, scope 1 covered the emissions within the park boundary, scope 2 emissions covered those resulting from electricity and heat usage inside the boundary, and scope 3 included those indirect emissions beyond the boundary. The Maanshan Economic and Technological Development Area (MDA), a typical booming national eco-industrial park of China, was chosen for this case study. The results showed that the MDA CO2 emissions increased yearly, from 376,836.57 tons in 2016 to 772,170.93 tons in 2021. From the industrial structure perspective, heavy industry contributed the highest emissions. By dividing the emissions into scope 1, 2, and 3, scope 2 could be identified as the largest emissions source. In addition, we conducted inventory uncertainty analyses incorporated by activity levels, emissions factors, and unspecific factors. Overall, these results may promote the establishment of greenhouse gas accounting standards for Chinese industrial parks.

Predicting global potential distribution of Peromyscopsylla hesperomys and Orchopeas sexdentatus and risk assessment for invading China under climate change.

Background: Peromyscopsylla hesperomys and Orchopeas sexdentatus are regarded to be representative plague vectors in the United States. The incidence of plague is rising globally, possibly due to climate change and environmental damage. Environmental factors such as temperature and precipitation have a significant impact on the temporal and spatial distribution of plague vectors. Methods: Maximum entropy models (MaxEnt) were utilized to predict the distributions of these two fleas and their trends into the future. The main environmental factors influencing the distribution of these two fleas were analyzed. A risk assessment system was constructed to calculate the invasion risk values of the species. Results: Temperature has a significant effect on the distribution of the potentially suitable areas for P. hesperomys and O. sexdentatus. They have the potential to survive in suitable areas of China in the future. The risk assessment system indicated that the risk level for the invasion of these two species into China was moderate. Conclusion: In order to achieve early detection, early interception, and early management, China should perfect its monitoring infrastructure and develop scientific prevention and control strategies to prevent the invasion of foreign flea vectors.

Evaluation of the quality of COVID-19 prevention and control by a novel comprehensive evaluation model in a tertiary general hospital: a prospective observational study.

BACKGROUND: Prevention and control (P&C) of Corona Virus Disease 2019 (COVID-19) is still a critical task in most countries and regions. However, there are many single evaluation indexes to assess the quality of COVID-19 P&C. It is necessary to synthesize the single evaluation indexes reasonably to obtain the overall evaluation results. METHODS: This study was divided into three steps. Step 1: In February 2020, the improved Delphi method was used to establish the quality evaluation indexes system for COVID-19 P&C. Step 2: in March 2020, the CRITIC method was used to adjust the Order Relation Analysis (G1) method to obtain the subjective and objective (S&O) combination weights. The comprehensive evaluation value was obtained using the weighted Efficacy Coefficient (EC) method, weighted TOPSIS method, weighted rank-sum ratio (RSR) method, and weighted Grey Relationship Analysis (GRA) method. Finally, the linear normalization method was used to synthesize the evaluation values of different evaluation methods. Step 3: From April 2020 to May 2021, this evaluation method was used to monitor and assess COVID-19 P&C quality in critical departments prospectively. The results were reported to the departments monthly. RESULT: A quality evaluation indexes system for COVID-19 P&C was established. Kendall's consistency test shows that the four evaluation method had good consistency (χ2 = 43.429, P<0.001, Kendall's consistency coefficient = 0.835). The Spearman correlation test showed that the correlation between the combined evaluation results and the original method was statistically significant(P < 0.001). According to the Mann-Kendall test, from March 2020 to May 2021, the mean value of COVID-19 P&C quality in all critical departments showed an upward trend (P < 0.01). CONCLUSIONS: The combined comprehensive evaluation method based on the S&O combined weight was more scientific and comprehensive than the single weighting and evaluation methods. In addition, monitoring and feedback of COVID-19 P&C quality were helpful for the improvement of P&C quality.

Global, regional, and national prevalence, disability adjusted life years, and time trends for refraction disorders, 1990-2019: findings from the global burden of disease study 2019.

BACKGROUND: To evaluate global burden of refraction disorders by year, age, region, gender, socioeconomic status and other national characteristics in terms of disability adjusted life years (DALYs) and prevalence from Global Burden of Disease (GBD) study 2019 and World Bank Open Data 2019. METHODS: Global, regional, and national DALY numbers, crude DALY rates, age-standardized DALY and prevalence rates of refraction disorders were acquired from the GBD study 2019. Mobile cellular subscriptions, urban population, GDP per capita, access to electricity and total fertility rate were obtained from the World Bank to explore the factors that influenced the health burden of refraction disorders. Kruskal-Wallis test, linear regression and multiple linear regression were performed to evaluate the associations between the health burden with socioeconomic levels and other national characteristics. Wilcoxon Signed-Rank Test was used to investigate the gender disparity. RESULTS: Globally, age-standardized DALY rates of refraction disorders decreased from 88.9 (95% UI: 60.5-120.3) in 1990 to 81.5 (95% UI: 55.0-114.8) in 2019, and might fall to 73.16 (95% UI: 67.81-78.51) by 2050. Age-standardized prevalence rates would also reduce to 1830 (95% UI: 1700-1960) by 2050, from 2080 (95% UI: 1870-2310) in 1990 to 1960 (95% UI: 1750-2180) in 2019. In low SDI region, age-standardized DALY rates (equation: Y = 114.05*X + 27.88) and prevalence rates (equation: Y = 3171.1*X + 403.2) were positively correlated with SDI in linear regression respectively. East Asia had the highest blindness rate caused by refraction disorders in terms of age-standardized DALY rates (11.20, 95% UI: 7.38-16.36). Gender inequality was found among different age groups and SDI regions. CONCLUSION: Health burden of refraction disorders decreased in recent years, and may continue to alleviate in the next three decades. Older ages, females and lower socioeconomic status were associated with higher refraction disorders health burden.

Quantitative Assessment of Fundus Tessellated Density and Associated Factors in Fundus Images Using Artificial Intelligence.

Purpose: This study aimed to quantitative assess the fundus tessellated density (FTD) and associated factors on the basis of fundus photographs using artificial intelligence. Methods: A detailed examination of 3468 individuals was performed. The proposed method for FTD measurements consists of image preprocessing, sample labeling, deep learning segmentation model, and FTD calculation. Fundus tessellation was extracted as region of interest and then the FTD could be obtained by calculating the average exposed choroid area of per unit area of fundus. Besides, univariate and multivariate linear regression analysis have been conducted for the statistical analysis. Results: The mean FTD was 0.14 ± 0.08 (median, 0.13; range, 0-0.39). In multivariate analysis, FTD was significantly (P < 0.001) associated with thinner subfoveal choroidal thickness, longer axial length, larger parapapillary atrophy, older age, male sex and lower body mass index. Correlation analysis suggested that the FTD increased by 33.1% (r = 0.33, P < .001) for each decade of life. Besides, correlation analysis indicated the negative correlation between FTD and spherical equivalent (SE) in the myopia participants (r = -0.25, P < 0.001), and no correlations between FTD and SE in the hypermetropia and emmetropic participants. Conclusions: It is feasible and efficient to extract FTD information from fundus images by artificial intelligence-based imaging processing. FTD can be widely used in population screening as a new quantitative biomarker for the thickness of the subfoveal choroid. The association between FTD with pathological myopia and lower visual acuity warrants further investigation. Translational Relevance: Artificial intelligence can extract valuable clinical biomarkers from fundus images and assist in population screening.

Research on the economic loss of hospital-acquired pneumonia caused by Klebsiella pneumonia base on propensity score matching.

BACKGROUND: Hospital-acquired pneumonia (HAP) caused by Klebsiella pneumonia (KP) is a common nosocomial infection (NI). However, the reports on the economic burden of hospital-acquired pneumonia caused by Klebsiella pneumonia (KP-HAP) were scarce. The study aims to study the direct economic loss caused by KP-HAP with the method of propensity score matching (PSM) to provide a basis for the cost accounting of NI and provide references for the formulation of infection control measures. METHODS: A retrospective investigation was conducted on the hospitalization information of all patients discharged from a tertiary group hospital in Shenzhen, Guangdong province, China, from June 2016 to August 2019. According to the inclusion and exclusion criteria, patients were divided into the HAP group and noninfection group, the extended-spectrum beta-lactamases (ESBLs) positive KP infection group, and the ESBLs-negative KP infection group. After the baselines of each group were balanced with the PSM, length of stay (LOS) and hospital cost of each group were compared. RESULTS: After the PSM, there were no differences in the baselines of each group. Compared with the noninfection group, the median LOS in the KP-HAP group increased by 15 days (2.14 times), and the median hospital costs increased by 7329 yuan (0.89 times). Compared with the ESBLs-negative KP-HAP group, the median LOS in the ESBLs-positive KP-HAP group increased by 7.5 days (0.39 times), and the median hospital costs increased by 22,424 yuan (1.90 times). CONCLUSION: KP-HAP prolonged LOS and increased hospital costs, and HAP caused by ESBLs-positive KP had more economic losses than ESBLs-negative, which deserves our attention and should be controlled by practical measures.

Comparison of two electronic hand hygiene monitoring systems in promoting hand hygiene of healthcare workers in the intensive care unit.

BACKGROUND: Hand hygiene (HH) is the cornerstone of infection control, and the promotion of HH is the focus of the world. The study aims to compare the role of two different types of electronic hand hygiene monitoring systems (EHHMSs) in promoting HH of healthcare workers (HCWs) in the intensive care unit (ICU). METHODS: In a 16-bed ICU of a general tertiary hospital in Shenzhen, the research was divided into three stages with interrupted time series (ITS) design. In the first stage, the direct observation method was used to monitor and feed back the HH compliance rate of HCWs monthly. In the second stage, the type1 EHHMS was applied to monitor and feed back the individual number of HH events monthly. In the third stage, the type2 EHHMS with a function of instant reminder and feedback was employed, and the personal HH compliance rates were fed back monthly. Meanwhile, direct observation continued in the last two stages. RESULTS: In the second stage, The HH compliance rate increased. However, there was no significant difference in the trajectory of the rate compared with the first stage. In the first month of the third stage, the HH compliance rate increased by 12.324% immediately and then ascended by 1.242% over time. The number of HH events per bed day and HH products' consumption per bed day were consistent with the change of HH compliance rate observed. CONCLUSION: Monitoring and feedback can improve the HH of HCWs. The EHHMS, with the function of real-time reminders and feedback, has a more noticeable effect on promoting HH.

Nonalcoholic fatty liver disease: impact on healthcare resource utilization, liver transplantation and mortality in a large, integrated healthcare system.

BACKGROUND AND AIMS: NAFLD is the most prevalent liver disease globally, affecting 20% of the world population. Healthcare resource utilization (HRU) attributable to NAFLD has been difficult to define. METHODS: We performed a case control study on NAFLD patients from 2005 to 2015 in a large integrated healthcare system with an affiliated insurance company that prospectively captures HRU information. Outcomes encompassed costs, liver transplantation and mortality rates. RESULTS: There were 17,085 patients, of which 4512 were NAFLD cases and 12,573 were non-NAFLD controls. The cohorts were similar in age and gender distribution (p > 0.05). The NAFLD cohort had a younger mean age of death (60.9 vs. 63.3, p = 0.004) and had over twice the number of annual healthcare visits (14.6 vs. 7.1). The increased overall annual overall cost attributable to NAFLD (in 2015 $) was $449/year. Overall, NAFLD was independently associated with 17% higher annual attributable healthcare costs. More advanced NAFLD (FS 3-4) was associated with a 40% increase in median annual healthcare costs (vs. FS 0-2). The strongest predictors of HRU among patients with NAFLD were advanced fibrosis and medical co-morbidities. The rate of liver transplantation was 18 times greater (0.054%/year) in the NAFLD compared with the non-NAFLD cohort, while mortality rate was 1.7 times greater. CONCLUSIONS: Within a large, integrated healthcare system a diagnosis of NAFLD is independently associated with a 17% overall excess in HRU and a several-fold increase liver transplantation and mortality. Although the dollar amounts will change over time and between healthcare systems, the proportional need for HRU will have broad applicability and implications.

Homogeneity assessment for pivotal medical device clinical studies.

A question that routinely arises in medical device clinical studies is the homogeneity across demographic subgroups, geographical regions, or investigational sites of the enrolled patients in terms of treatment effects or outcome variables. The main objective of this paper is to discuss statistical concepts and methods for the assessment of such homogeneity and to provide the practitioner a statistical framework and points to consider in conducting homogeneity assessment. Demographic subgroups, geographical regions, and investigational sites are discussed separately as each has its unique issues. Specific considerations are also given to randomized controlled trials, non-randomized comparative studies, and single-arm studies. We point out that judicious use of statistical methods, in conjunction with sound clinical judgment, is essential in handling the issue of homogeneity of treatment effect in medical device clinical studies.

Field assessment of the effects of land-cover type and pattern on PM10 and PM2.5 concentrations in a microscale environment.

The microscale environment is a very important human-scale outdoor spatial unit. Aimed at investigating the effects of microscale land-cover type and pattern on levels of PM10 and PM2.5, we monitored PM10 and PM2.5 concentrations among different land-cover type and pattern sites through field measurements, during four seasons (December 2015 to November 2016) in Beijing, China. Differences of daily PM10 and PM2.5 concentrations among seven typical land-cover types, and correlations between daily two-sized PM levels and various microscale land-cover patterns as explained by landscape metrics were analyzed. Results show that concentrations of the two-sized particles had stable daytime and seasonal trends. During the four seasons, there were various differences in daily PM10 and PM2.5 levels among the seven land-cover types. Overall, bare soil always had the highest daily PM10 level, whereas high canopy density vegetation and water bodies had low levels. Maximum PM2.5 levels were always found in high canopy density vegetation. Moderate canopy density vegetation and water bodies had lower concentrations. Correlations between different landscape metrics and daily levels of two-sized PM varied by season. Metrics reflecting the dominance and distribution of land-cover classifications had closer relationships with particle concentrations in the microscale environment. The patterns of pavement along with low and moderate canopy density vegetation had a greater impact on PM10 level. The responses of PM2.5 level to patterns of building and low and moderate canopy density vegetation were sensitive. Reasonable design of land-cover structure would be conducive to ameliorate air particle concentrations in the microscale environment. Graphical abstract ᅟ.

[Emission Inventory of Greenhouse Gas from Urban Wastewater Treatment Plants and Its Temporal and Spatial Distribution in China].

Urban wastewater treatment plants are considered important greenhouse gas resources with massive emissions of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) during operation. Based on the emission factor approach of pollutant reduction, the 2014 emission inventory of greenhouse gases (CO2, CH4, and N2O) from urban wastewater treatment plants in China was established. In addition, the temporal and spatial distribution and influencing factors of greenhouse gas emissions were analyzed in this study. The results showed that total emissions of greenhouse gas from urban wastewater treatment plants in China was 7348.60 Gg (CO2-eq) in 2014, which included CO2, CH4, and N2O emissions of 6054.57 Gg, 27.47 Gg (769.08 Gg, CO2-eq), and 1.98 Gg (524.95 Gg, CO2-eq), respectively. The difference in greenhouse gas emissions among provinces was significant:high emissions appeared in the eastern areas of China, low emissions were observed in the northwest, and hardly any emissions were found in Xizang. From 2005 to 2014, annual greenhouse gas emissions from urban sewage treatment plants in China increased by 229.4%, and the rates of CO2, CH4, and N2O increased by 217.9%, 217.9%, and 520.3%, respectively. The regional economic development level and number of wastewater treatment plants were correlated the most with the emissions of greenhouse gasses, and the per-capita protein supply was closely related with the N2O emission.

Low-Cost and Scaled-Up Production of Fluorine-Free, Substrate-Independent, Large-Area Superhydrophobic Coatings Based on Hydroxyapatite Nanowire Bundles.

To date, the scaled-up production and large-area applications of superhydrophobic coatings are limited because of complicated procedures, environmentally harmful fluorinated compounds, restrictive substrates, expensive equipment, and raw materials usually involved in the fabrication process. Herein, the facile, low-cost, and green production of superhydrophobic coatings based on hydroxyapatite nanowire bundles (HNBs) is reported. Hydrophobic HNBs are synthesised by using a one-step solvothermal method with oleic acid as the structure-directing and hydrophobic agent. During the reaction process, highly hydrophobic C-H groups of oleic acid molecules can be attached in situ to the surface of HNBs through the chelate interaction between Ca2+ ions and carboxylic groups. This facile synthetic method allows the scaled-up production of HNBs up to about 8 L, which is the largest production scale of superhydrophobic paint based on HNBs ever reported. In addition, the design of the 100 L reaction system is also shown. The HNBs can be coated on any substrate with an arbitrary shape by the spray-coating technique. The self-cleaning ability in air and oil, high-temperature stability, and excellent mechanical durability of the as-prepared superhydrophobic coatings are demonstrated. More importantly, the HNBs are coated on large-sized practical objects to form large-area superhydrophobic coatings.

The salutary effect of an integrated system on the rate of repeat CT scanning in transferred trauma patients: Improved costs and efficiencies.

BACKGROUND: Duplication of Computed Tomography (CT) scanning in trauma patients has been a source of quality waste in healthcare and potential harm for patients. Integrated and regional health systems have been shown to promote opportunities for efficiencies, cost savings and increased safety. METHODS: This study evaluated traumatically injured patients who required transfer to a Level One Trauma Center (TC) from either within a vertically integrated healthcare system (IN) or from an out-of-network (OON) hospital. RESULTS: We found the rate of repeat CT scanning, radiology costs and total costs for day one of hospitalization to be significantly lower for trauma patients transferred from an IN hospital as compared to those patients transferred from OON hospitals. CONCLUSION: The inefficiencies and waste often associated with transferred patients can be mitigated and strategies to do so are necessary to reduce costs in the current healthcare environment.

Security and cost comparison of INR self-testing and conventional hospital INR testing in patients with mechanical heart valve replacement.

BACKGROUND: International normalized ratio (INR) self-testing can improve the management of anticoagulation therapy with warfarin for the patients following mechanical heart valve replacement. Several reviews and studies have demonstrated self-management as an option to improve patient's outcome considerably after mechanical heart valve replacement. We sought to analyze the security, economy and discuss the prospect of self-testing of anticoagulation therapy in patients following mechanical heart valve replacement in China, and evaluate the accuracy and stability of CoaguChek XS portable INR-testing device. METHODS: This was a prospective self-controlled clinical study conducted with 526 patients receiving oral warfarin anticoagulation therapy after mechanical heart valve replacement in the period of Mar.1, 2012 - Nov.1, 2012 in Cardiovascular Surgery Department of West China Hospital of Sichuan University. The same patient performed INR testing with CoaguChek XS portable coagulometer (group1) and central lab (group 2) in parallel. The follow-up time was 6 months. Meanwhile, a questionnaire was handed out to survey the expenses required for the re-examination visits to the hospital, time, and anticoagulation complications. RESULTS: No severe anticoagulation complications occurred in all the patients. No significant difference of the INR results were observed between group 1 and group 2, they showed significant relevance, r = 0.953(p < 0.05). Compared with the conventional method of INR testing in hospital, the portable coagulometer is convenient, quick and less traumatic. Self-testing of anticoagulation therapy reduced the cost and the time required for re-examination. CONCLUSIONS: Results of CoaguChek XS monitor are precise and have a good consistency and stability as compared with traditional laboratory testing. For the patients receiving anticoagulation therapy after mechanical heart valve replacement, the self-testing of anticoagulation therapy with portable coagulometer is a safe choice, and it has a promising future application in China.

Porcine bone grafts defatted by lipase: efficacy of defatting and assessment of cytocompatibility.

Defatting is an important procedure for the preparation of bone grafts because lipids in bone grafts strongly influence the osteointegration. Lipases have been widely used in different fields. However, study on the application to defatting process for bone grafts preparation has never been found so far. In this study, bone samples were treated respectively by lipase, NaHCO(3)/Na(2)CO(3), acetone and deionized water. The lipids content of processed bone grafts was calculated in Soxhlet extractor method. Surface morphology of the bone grafts was observed under scanning electron microscope (SEM). DNA content of processed bone grafts was measured. Cytocompatibility was evaluated by co-culturing mouse preosteoblasts (MC3T3-E1) on defatted bone cubes. Proliferation rates of MC3T3-E1 were examined by cell counting kit-8 (CCK-8) assay. No statistically significant difference was found between lipids amount of bone processed by lipase (0.46 ± 0.16 %) and acetone (1.11 ± 0.13 %) (P > 0.05). Both of them were significantly lower than that in groups processed by Na(2)CO(3)/NaHCO(3) (3.46 ± 0.69 %) and deionized water (8.88 ± 0.18 %) (P = 0.000). Only cell debris were discovered over the surface of bone processed by lipase or acetone, while lipid droplets were observed on bone processed by Na(2)CO(3)/NaHCO(3) or water by SEM. The difference of DNA concentration between the bone processed by lipase (3.16 ± 0.81 ng/µl) and acetone (4.14 ± 0.40 ng/µl) is not statistically significant (P > 0.05). Both of them are significantly lower than that groups processed by Na(2)CO(3)/NaHCO(3) (5.22 ± 0.38 ng/µl) and water (7.88 ± 0.55 ng/µl) (P < 0.05). MC3T3-E1 cells maintained their characteristic spreading on the trabecular surfaces of bone processed by lipase. There were no statistically significant differences among absorbance of lipase, acetone groups in CCK-8 assay. The application of lipase to bone tissue defatting appears to be a very promising technique for bone grafts preparation.