A tripartite evolutionary game study of low-carbon innovation system from the perspective of dynamic subsidies and taxes.

Traditional manufacturing industry is in the early stages of transition to low-carbon innovative production, and is in urgent need of a low-carbon innovation system to achieve the goal of carbon neutrality. In order to realize the effective supervision of enterprise carbon emissions, this paper constructs a tripartite evolutionary game model among the corporate, government and public from the perspective of dynamic subsidies and taxes. The main results are as follows. First, the increase in government subsidies to a certain extent will help encourage companies to choose low-carbon innovative production strategies, but more subsidies are not always better. Excessive subsidies will increase the cost of government regulation and reduce the probability of government regulation. Second, the tripartite evolutionary game system does not converge under the static subsidies and taxes mechanism. But the system could quickly converges to the stable condition under dynamic subsidies and taxes. The stable point is the situation of corporate low-carbon innovation, government regulation, and public supervision. Third, the public intervention and supervision can effectively prevent the phenomenon of government misconduct and enterprises over-emission production. And the influence of public reward and punishment is more effective for the government than for enterprises.

3D-printed antibiotic-loaded bone cement spacers as adjunctive therapy for hip periprosthetic infection after arthroplasty: A clinical assessment.

OBJECTIVE: To explore the effect of three-dimensional (3D) printing to create personalized antibiotic-loaded bone cement (ALBC) spacers to assist in treatment of periprosthetic infection after total hip arthroplasty (THA). METHODS: The data of 40 patients with postoperative infection after THA were analysed retrospectively. The patients were divided into two groups: the 3D-printing group (age 47-78 years, n = 20) and the conventional group (age 57-78 years, n = 20). In stage I surgery, 3D-printed silicone moulds were used to create ALBC spacers for the 3D-printing group, while traditional manual methods were used to create spacers for the conventional group. After the infection was controlled, both groups underwent conventional hip revision surgery (stage II surgery). All patients were evaluated using the Harris Hip Score (HHS) (primary outcome) for hip function. RESULTS: All 40 patients had follow-up data from 3 months after stage I surgery and 12 months after stage II surgery. The intergroup difference in HHS was 11.25 points [97.5% confidence interval (CI) 7.92-14.58; P < 0.01] at 3 months after stage I surgery, and 9.15 points (97.5% CI 4.82-13.48; P < 0.01) at 12 months after stage II surgery. The overall difference between the two groups was 9.55 points (97.5% CI 5.83-13.27; P < 0.01), which was significant (P < 0.05). CONCLUSION: During the follow-up period, the hip function of the 3D-printing group was superior to that of the conventional group following the treatment of infections after THA.

Multidimensional evaluation method and application based on life cycle carbon efficiency considering carbon emission, cost, and function.

Low carbon research has currently become the most discussed environmental issue. Current comprehensive evaluation methods for low carbon consider carbon emission, cost, process parameters, and resource utilization, but the realization of low carbon may lead to cost fluctuations and functional changes and lack consideration of product functional requirements. Hence, this paper developed a multidimensional evaluation method for low-carbon research based on the association among three dimensions, namely, carbon emission, cost, and function. This multidimensional evaluation method was named life cycle carbon efficiency (LCCE), which is defined as the ratio between the value in the life cycle and the carbon emissions generated. The LCCE model was established, and then carbon emission calculation, cost assessment, and function quantification of the life cycle were performed according to the three dimensions. Case study and sensitivity analysis verified the feasibility of the proposed method. The method had comprehensive and accurate evaluation results, which provided theoretical support and optimized the low-carbon design.

Market Integration and Price Dynamics under Market Shocks in European Union Internal and External Cheese Export Markets.

The dairy sector in the European Union (EU) has experienced policy changes and market shocks recently. Using the global vector autoregressive (GVAR) model, this paper explores regional market integration, the feedback between market shocks and price dynamics, and the link between EU's cheese export markets and energy market. This paper assesses and compares which influencing factors are typically associated with intra-EU and extra-EU cheese export price movement with regards to shocks to crude oil price, farm-gate raw milk price, and consumer price index (CPI) for food and cheese production of six representative EU member states, respectively. Using generalized impulse response functions, this paper finds that EU's internal cheese export market is not well integrated, while EU's external market is well integrated, with France as an exception. It also finds that the external cheese export market is vulnerable to shocks from the energy market compared to the internal market. Raw milk prices from the upstream supply chain have strong spill-over effects on EU's internal cheese export market, yet their impact on extra-EU cheese export prices is relatively less significant. The movement patterns of extra-EU cheese export prices of Ireland and the UK show similar patterns in the long run. It is concluded that the dynamics of cheese export prices in the internal and external markets of the EU are different under market shocks.

Automatic classification of heterogeneous slit-illumination images using an ensemble of cost-sensitive convolutional neural networks.

BACKGROUND: Lens opacity seriously affects the visual development of infants. Slit-illumination images play an irreplaceable role in lens opacity detection; however, these images exhibited varied phenotypes with severe heterogeneity and complexity, particularly among pediatric cataracts. Therefore, it is urgently needed to explore an effective computer-aided method to automatically diagnose heterogeneous lens opacity and to provide appropriate treatment recommendations in a timely manner. METHODS: We integrated three different deep learning networks and a cost-sensitive method into an ensemble learning architecture, and then proposed an effective model called CCNN-Ensemble [ensemble of cost-sensitive convolutional neural networks (CNNs)] for automatic lens opacity detection. A total of 470 slit-illumination images of pediatric cataracts were used for training and comparison between the CCNN-Ensemble model and conventional methods. Finally, we used two external datasets (132 independent test images and 79 Internet-based images) to further evaluate the model's generalizability and effectiveness. RESULTS: Experimental results and comparative analyses demonstrated that the proposed method was superior to conventional approaches and provided clinically meaningful performance in terms of three grading indices of lens opacity: area (specificity and sensitivity; 92.00% and 92.31%), density (93.85% and 91.43%) and opacity location (95.25% and 89.29%). Furthermore, the comparable performance on the independent testing dataset and the internet-based images verified the effectiveness and generalizability of the model. Finally, we developed and implemented a website-based automatic diagnosis software for pediatric cataract grading diagnosis in ophthalmology clinics. CONCLUSIONS: The CCNN-Ensemble method demonstrates higher specificity and sensitivity than conventional methods on multi-source datasets. This study provides a practical strategy for heterogeneous lens opacity diagnosis and has the potential to be applied to the analysis of other medical images.

In vivo percutaneous permeation of gold nanomaterials in consumer cosmetics: implication in dermal safety assessment of consumer nanoproducts.

The increasing emergence of nano-cosmetics in the marketplace provokes safety concerns with respect to percutaneous permeation and toxicity of nanomaterials inside the human body. In this study, in vivo percutaneous permeation and dermal safety of cosmetic cream containing Au nanosheets and extracted Au nanosheets from cosmetic creams are investigated with guinea pigs. Quantitative percutaneous permeation data suggests that Au nanosheets in cosmetic creams permeate into the skin epidermis, dermis, and subcutaneous layer after 10 d cutaneous exposure, but cannot enter the systemic circulation. However, more Au nanosheets are accumulated in the skin and the permeation of Au nanosheets increased after embedded into the cream matrix. Synchrotron radiation X-ray fluorescence (SRXRF) imaging reveals that Au nanosheets in cosmetics penetrate mainly through hair follicles in a time-dependent manner. Cosmetic creams rather than extracted Au nanosheets decrease the cell viability of keratinocytes and slightly induce apoptosis/necrosis of keratinocytes and skin dermal fibroblasts. Intriguingly, the growth of hair is inhibited by the cosmetic cream and the extracted Au nanosheets revealed by HE staining and immunohistochemistry (IHC) assay. Altogether this study provides insights into the comprehensive understanding of percutaneous permeation and dermal safety of cosmetic creams containing Au nanosheets. This work provides reliable methods to study the skin permeation, biodistribution, and dermal safety of nano-cosmetics and reminds the community of the crucial need to combine the assays at molecular, cellular, and organ levels in nanotoxicology research.

Development of prognostic model for patients at CKD stage 3a and 3b in South Central China using computational intelligence.

BACKGROUND: Chronic kidney disease (CKD) stage 3 was divided into two subgroups by eGFR (45 mL/ min 1.73 m2). There is difference in prevalence of CKD, racial differences, economic development, genetic, and environmental backgrounds between China and Western countries. METHODS: We used a computational intelligence model (CKD stage 3 Modeling, CSM) to distinguish CKD stage 3 with CKD stage 3a/3b by data distribution rules, pearson correlation coefficient (PCC), spearman correlation (SCC) analysis, logistic regression (LR), random forest (RF), support vector machine (SVM), and neural network (Nnet) to develop Prognostic Model for patients with CKD stage 3a/3b in South Central China. Furthermore, we used RF to discover risk factors of progression of CKD stage 3a and 3b to CKD stage 5. 1090 cases of CKD stage 3 patients in Xiangya Hospital were collected. Among them, 455 patients progressed to CKD stage 5 in a median follow-up of 4 years (IQR 4.295, 4.489). RESULTS: We found that the common risk factors for progression of CKD stage 3a/3b to CKD stage 5 included albumin, creatinine, total protein, etc. Proteinuria, direct bilirubin, hemoglobin, etc. accounted for the progression from stage CKD stage 3a to stage 5. The risk factors for CKD stage 3b progression to stage 5 included low-density lipoprotein cholesterol, diabetes, eosinophil percentage, etc. CONCLUSIONS: CSM could be used as a point-of-care test to screen patients at high risk for disease progression, might allowing individualized therapeutic management.

Theoretical assessment of wettability on silane coatings: from hydrophilic to hydrophobic.

The potential distribution and work function of a graphene surface modified by various types of silanes are investigated by first principles quantum mechanical calculations to establish its surface hydrophobicity hierarchy. It is found that the work function relies on the electronegativity of atoms on silane. The localization feature of interaction between silane and the graphene surface is demonstrated by the electron density difference. The work function is demonstrated to be a critical quantity in understanding the surface polarizability and thereby the surface wetting properties. By performing contact angle measurements experimentally using water as the probe fluid, surfaces grafted with different silanes show hydrophobicity variation that is found to follow the reverse trend to that of the proposed surface polarizability obtained through the work function calculation. The work function-dependent contact angle can be fitted with a linear equation.

Mobile Health (mHealth) technology for improved screening, patient involvement and optimising integrated care in atrial fibrillation: The mAFA (mAF-App) II randomised trial.

BACKGROUND: Current management of patients with atrial fibrillation (AF) is limited by low detection of AF, non-adherence to guidelines and lack of consideration of patient's preferences, thus highlighting the need for a holistic and integrated approach to AF management. This study aims to determine whether a mHealth technology-supported AF integrated management strategy will reduce AF-related adverse events. METHODS/DESIGN: The mAFA II trial is a prospective, cluster randomised controlled trial. The 40 sites will be randomised to mAFA-integrated care intervention or usual care arms. Prior to randomisation, study sites will be paired to be matched in size and the proportion of study eligible patients. All AF patients aged over 18 years old with CHA2 DS2 -VASc score ≥ 2 will be enrolled. Assuming a composite adverse event rate of 10% pre-intervention, reduced to 5% after intervention, we aim to recruit 3660 patients assuming a 10% loss to follow-up. The primary study endpoint is a composite of stroke/thromboembolism, all-cause death and rehospitalisation. Ancillary analyses would determine patient-related outcome measures, health economics and cost effectiveness, as well as an embedded qualitative study. DISCUSSION: The mAFA II trial will provide evidence for an integrated care approach to holistic AF care, supported by mobile health technology to improve screening, patient involvement and optimisation of management.

Assessment of p16 expression and HPV infection in adenoid cystic carcinoma of the lacrimal gland.

Purpose: Adenoid cystic carcinoma (ACC) in the lacrimal gland is a rare malignancy. P16 is encoded by the CDKN2A gene, which is recognized as a tumor suppressor due to its inactivation in many types of tumors. However, p16 overexpression is also linked to adverse tumor parameters. These contradictory observations have also been confirmed in ACCs in the salivary glands. Furthermore, evidence of human papilloma virus (HPV) infection is found in a proportion of ACCs in the salivary glands. P16 is often overexpressed in HPV-related squamous cell carcinoma in parallel. To our knowledge, the role of p16 and HPV in ACCs in the lacrimal gland is still unknown. Methods: Twenty-one ACCs in the lacrimal gland and ten matched healthy lacrimal glands were studied. P16 was detected with immunohistochemistry (IHC), and HPV was detected with in situ hybridization (ISH) and PCR in all cases. Other cell cycle proteins were also detected with IHC, including cyclin D1 and Ki67. The methylation status of the p16 promoter was detected with methylation-specific PCR (MSP) to further investigate the regulation of p16 expression. Results: The expression rates of p16 (47.6%, 10/21), cyclin D1 (100%, 21/21), and Ki67 (52.4%, 11/21) were increased in ACCs compared to healthy lacrimal glands (negative). The results showed p16 expression was limited to the inner ductal epithelial cells in the majority of the tubular and cribriform patterns. In solid ACCs, p16 was uniformly positive. HPV was negative in all 21 cases with ISH and PCR. P16 overexpression was associated with cyclin D1 overexpression (p=0.013). Only 13 cases were tested successfully with MSP. The expression rate of p16 methylation was 23.1% (3/13) of the ACCs. Compared with primary ACCs, recurrent ACCs showed higher p16, cyclin D1, and Ki67 expression (p=0.011, p=0.026, p=0.049, respectively). Conclusions: In summary, p16 overexpression was cell-type dependent in ACCs in the lacrimal gland, while HPV infection was negative. P16 overexpression was unrelated to HPV infection. The mechanism of p16 overexpression needs to be further investigated in ACCs in the lacrimal gland.

Automatic diagnosis of imbalanced ophthalmic images using a cost-sensitive deep convolutional neural network.

BACKGROUND: Ocular images play an essential role in ophthalmological diagnoses. Having an imbalanced dataset is an inevitable issue in automated ocular diseases diagnosis; the scarcity of positive samples always tends to result in the misdiagnosis of severe patients during the classification task. Exploring an effective computer-aided diagnostic method to deal with imbalanced ophthalmological dataset is crucial. METHODS: In this paper, we develop an effective cost-sensitive deep residual convolutional neural network (CS-ResCNN) classifier to diagnose ophthalmic diseases using retro-illumination images. First, the regions of interest (crystalline lens) are automatically identified via twice-applied Canny detection and Hough transformation. Then, the localized zones are fed into the CS-ResCNN to extract high-level features for subsequent use in automatic diagnosis. Second, the impacts of cost factors on the CS-ResCNN are further analyzed using a grid-search procedure to verify that our proposed system is robust and efficient. RESULTS: Qualitative analyses and quantitative experimental results demonstrate that our proposed method outperforms other conventional approaches and offers exceptional mean accuracy (92.24%), specificity (93.19%), sensitivity (89.66%) and AUC (97.11%) results. Moreover, the sensitivity of the CS-ResCNN is enhanced by over 13.6% compared to the native CNN method. CONCLUSION: Our study provides a practical strategy for addressing imbalanced ophthalmological datasets and has the potential to be applied to other medical images. The developed and deployed CS-ResCNN could serve as computer-aided diagnosis software for ophthalmologists in clinical application.

Impact of price deregulation policy on the affordability of essential medicines for women's health: a panel data analysis.

BACKGROUND: A new policy which required deregulation on prices of off-patent medicines for women's health during procurement was introduced in China in September 2015. The current study examines this policy's impact on the affordability of essential medicines for women's health. METHODS: Based on product-level panel data, a fixed effect regression model is employed by using procurement records from Hubei Centralist Tender for Drug Purchase platform. In the model, Affordability was measured with prices. The Competition consists of two parts: generic competition and therapeutic class competition which are measured with generic competitors and therapeutic substitutes. Instrument variable is used to deal with endogeneity. RESULTS: The policy helped control prices of essential medicines for women's health. Generic competition helped control prices, however, therapeutic class competition caused higher prices. CONCLUSIONS: The new policy helped enhance the affordability of essential medicines for women's health as expected, which provides empirical evidence on price deregulation. Besides, generic competition is important in price control despite strict regulatory system in China.

Cost-effectiveness of integrated routine offering of prenatal HIV and syphilis screening in China.

BACKGROUND: In China, recent rises in syphilis and HIV cases have increased the focus on preventing mother-to-child transmission of these infections. We assess the health and economic outcomes of different strategies of prenatal HIV and syphilis screening from the local health department's perspective. METHODS: A Markov cohort decision analysis model was used to estimate the health and economic outcomes of pregnancy using disease prevalence and cost data from local sources and, if unavailable, from published literature. Adverse pregnancy outcomes included induced abortion, stillbirth, low birth weight, neonatal death, congenital syphilis in live-born infants, and perinatal HIV infection. We examined 4 screening strategies: no screening, screening for HIV only, for syphilis only, and for both HIV and syphilis. We estimated disability-adjusted life years (DALYs) for each health outcome using life expectancies and infections for mothers and newborns. RESULTS: For a simulated cohort of 10,000 pregnant women (0.07% prevalence for HIV and 0.25% for syphilis; 10% of HIV-positives were coinfected with syphilis), the estimated costs per DALY prevented were as follows: syphilis-only, $168; HIV-and-syphilis, $359; and HIV-only, $5636. The estimated incremental cost-effectiveness ratio if an existing HIV-only strategy added syphilis screening (i.e., move from the HIV-only strategy to the HIV-and-syphilis strategy) was $140 per additional DALY prevented. CONCLUSIONS: Given the increasing prevalence of syphilis and HIV among pregnant women in China, prenatal HIV screening programs that also include syphilis screening are likely to be substantially more cost-effective than HIV screening alone and prevent many more adverse pregnancy outcomes.

Assessment of anatomical and dosimetric changes by a deformable registration method during the course of intensity-modulated radiotherapy for nasopharyngeal carcinoma.

The aim of this study was to quantify the anatomic variations and the dosimetric effects accessed by a deformable registration method throughout the entire course of radiotherapy, and to evaluate the necessity of replanning for patients with nasopharyngeal carcinoma (NPC). Plan1(CT1) was based on the original CT, and Plan2(CT2) was generated from the midtreatment CT scan acquired after 25 fractions of IMRT of Plan1. Both sets of CTs, RT structures and RT doses for the two group plans were transferred to a workstation, and then a hybrid IMRT plan, Plan1(CT2), was generated by deforming doses of Plan1 to CT2. Subsequently, the accumulated plan, Plan1 + 2(CT2), was generated to quantify the actual dosimetric effects during the course. The transverse diameter of the neck at the center of the odontoid process was (15.4 ± 1.0) cm and (14.4 ± 1.1) cm in CT1 and CT2, respectively (P < 0.05). Compared with CT1, the mean volumes of the right and left parotid glands were significantly decreased by (24.6 ± 11.9)% and (35.1 ± 20.1)%, respectively. Comparison of Plan1 (CT1) with Plan1 (CT2) indicated that the doses to targets decreased without replanning. With repeated CT and replanning after 25 fractions, the doses to targets would be improved. The doses to normal tissue were increased without replanning. For eight patients out of 12, the doses to the spinal cord and brainstem exceeded the constraints without replanning, while the corresponding values decreased with replanning. During the entire course of IMRT, the volumes of the targets and the parotid glands would be reduced significantly. Midtreatment CT scanning and replanning are recommended to ensure adaptive doses to the targets and critical normal tissues.

Surgery for left ventricular aneurysm after myocardial infarction: techniques selection and results assessment.

BACKGROUND: The most appropriate surgical approach for patients with post-infarction left ventricular (LV) aneurysm remains undetermined. We compared the efficacy of the linear versus patch repair techniques, and investigated the mid-term changes of LV geometry and cardiac function, for repair of LV aneurysms. METHODS: We reviewed the records of 194 patients who had surgery for a post-infarction LV aneurysm between 1998 and 2010. Short-term and mid-term outcomes, including complications, cardiac function and mortality, were assessed. LV end-diastolic and systolic dimensions (LVEDD and LVESD), LV end-diastolic and end-systolic volume indexes (LVEDVI and LVESVI) and LV ejection fraction (LVEF) were measured on pre-operative and follow-up echocardiography. RESULTS: Overall in-hospital mortality was 4.12%, and major morbidity showed no significant differences between the two groups. Multivariate analysis identified preoperative left ventricular end diastolic pressure > 20 mmHg, low cardiac output and aortic clamping time > 2 hours as risk factors for early mortality. Follow-up revealed that LVEF improved from 37% pre-operation to 45% 12 months post-operation in the patch group (P = 0.008), and from 44% pre-operation to 40% 12 months postoperation in the linear group (P = 0.032). In contrast, the LVEDVI and LVESVI in the linear group were significantly reduced immediately after the operation, and increased again at follow-up. However, in the patch group, the LVEDVI and LVESVI were significantly reduced at follow-up. And there were significant differences in the correct value changes of LVEF and left ventricular remodeling between linear repair and patch groups. CONCLUSIONS: Persistent reduction of LV dimensions after the patch repair procedure seems to be a procedure-related problem. The choice of the technique should be tailored on an individual basis and surgeon's preference. The patch remodeling technique results in a better LVEF improvement, further significant reductions in LV dimensions and volumes than does the linear repair technique. The results suggest that LV patch remodeling is a better surgical choice for patients with post-infarction LV aneurysm.

Cost analysis of living donor kidney transplantation in China: a single-center experience.

BACKGROUND: Kidney transplantation is the most cost-effective option for the treatment of end-stage renal disease, but the financial aspects of kidney transplantation have not yet been fully investigated. The purpose of this study was to determine the hospital cost of living donor kidney transplantation in China and to identify factors associated with the high cost. MATERIAL/METHODS: Demographic and clinical data of 103 consecutive patients who underwent living donor kidney transplantation from January 2007 to January 2011 at our center were reviewed, and detailed hospital cost of initial admission for kidney transplantation was analyzed. A stepwise multiple regression analysis was computed to determine predictors affecting the total hospital cost. RESULTS: The median total hospital cost was US $10,531, of which 69.2% was for medications, 13.2% for surgical procedures, 11.4% for para clinics, 3.7% for accommodations, 0.5% for nursing care, and 2.0% for other miscellaneous medical services. A multivariate stepwise logistic regression model for overall cost of transplantation revealed that the length of hospital stay, induction therapy, steroid-resistant rejection, maintenance therapy, infection status and body weight were independent predictors affecting the total hospitalization cost. CONCLUSIONS: Although the cost of living donor kidney transplantation in China is much lower than that in developed countries, it is a heavy burden for both the government and the patients. As medications formed the greater proportion of the total hospitalization cost, efforts to reduce the cost of drugs should be addressed.

An improved risk of malignancy index in diagnosis of adnexal mass.

BACKGROUND: With the advent of color Doppler flow imaging (CDFI) and technological development of detection of serum tumor markers, new opportunities are presented to the improved risk of malignancy index (RMI) based on Jacobs' research for predicting ovarian malignancy in patients with adnexal masses. METHODS: One hundred and eighty women with an adnexal mass admitted for primary laparotomy were studied. Tumor specific growth factor (TSGF) adjusted ultrasound scores and the results of Doppler blood flow analysis were obtained before the operation. Based on the parameters which had been studied in Jacobs' research, TSGF levels and the findings of color Doppler flow imaging, the risk of malignancy model was redesigned using a binary Logistic regression model. The diagnostic efficacy of the improved risk of malignancy index (improved RMI) was compared with the Jacobs' model RMI by receiver operator characteristic (ROC) curve. RESULTS: The ROC curve showed a higher sensitivity (Mcnamer's test, P < 0.05) in the discrimination between benign and malignant adnexal masses for the improved RMI than the RMI. Compared with the RMI, the improved RMI had an advantage in prediction of ovarian germ cell tumors and granular cell tumor (28.57% vs.71.43%, P < 0.05) and the early stage tumors and borderline tumors (33.33% vs. 66.67%, P < 0.05). CONCLUSION: The predictability of the improved RMI is better than the classic Jacobs' model, especially in diagnosis of the ovarian germ cell tumors and granular cell tumor and other early stage adnexal tumors.

Gold nanomaterials: preparation, chemical modification, biomedical applications and potential risk assessment.

Gold nanomaterials (Au NMs) have attracted increasing attention in biomedicine due to their facile preparation, multifunctional modifications, unique optical and electrical properties, and good biocompatibility. The physicochemical properties of Au NMs at nanoscale, like size, shape, surface chemistry, and near field effects, are rendering Au NMs potent candidates in biomedicine. Thus, risk assessment of negative effects of Au NMs on biological systems is becoming urgent and necessary for future applications. In this review, we summarize up-to-date progresses on the preparation and modification of Au NMs and their biomedical applications, including biosensor, bioimaging and phototherapy, gene/drug delivery. Finally, we discuss the potential risk of Au NMs to biological systems, which is instructive for rationally designing and preparing nanomaterials for safe applications in nanomedicine.

Full assessment of fate and physiological behavior of quantum dots utilizing Caenorhabditis elegans as a model organism.

We evaluated the in vivo fate and physiological behavior of quantum dots (QDs) in Caenorhabditis elegans by GFP transfection, fluorescent imaging, synchrotron radiation based elemental imaging, and speciation techniques. The in situ metabolism and degradation of QDs in the alimentary system and long-term toxicity on reproduction are fully assessed. This work highlights the utility of the C. elegans model as a multiflexible platform to allow noninvasively imaging and monitoring in vivo consequences of engineered nanomaterials.

Two-dimensional strain combined with adenosine stress echocardiography assessment of viable myocardium.

The objective of this study was to explore a new method for the identification of viable myocardium by means of two-dimensional (2D) strain imaging combined with adenosine stress echocardiography. A total of 15 anesthetized open-chest healthy mongrel dogs underwent left anterior descending coronary artery occlusion for 90 min followed by 120-min reperfusion. Adenosine was infused at 140 µg kg(-1) min(-1) over a period of 6 min. Images were acquired at baseline (when pericardial cradle was made), after reperfusion (when reperfusion finished) and after adenosine administration (while administration stopped). Measurements of the regional peak-systolic strain in radial, circumferential, and longitudinal motion on anterior wall and anterior septum were, respectively, performed under different conditions. The dogs were killed after the echocardiographic studies finished and then the area of infracted myocardium was defined by triphenyltetrazolium chloride histology. A segment with equal or less than 50% area of infracted myocardium was considered to be viable. As a result, 37 regions were viable whereas 53 were non-viable among 90 regions in 15 dogs. At baseline, there was no significant difference in peak-systolic radial strain (Rs), circumferential strain (Cs), and longitudinal strain (Ls) between the viable and non-viable groups. After reperfusion, Rs, Cs, and Ls in absolute value decreased compared to those at baseline in both groups, although there was no significant difference between these groups. Rs and Ls increased after adenosine administration compared to reperfusion (p < 0.01; p < 0.05) in viable group while there were no changes in non-viable group. Compared with non-viable group Rs, Cs and Ls in viable group increased significantly (p < 0.01; 0.05) after adenosine administration. There was a negative correlation between Rs and infarct size (r = -0.72). Cs and Ls correlated well with infarct size, respectively (r = 0.40; 0.67). A change of Rs more than 13.5% has a sensitivity of 83.8% and a specificity of 83.0% for viable whereas a change of Ls more than 11% allowed a sensitivity of 78.4% and a specificity of 88.7%. Combined with these two variables, the sensitivity and specificity could reach 91.9 and 79.2%. Two-dimensional strain imaging combined with adenosine stress echocardiography can provide a new way to distinguish viable myocardium from the non-viable.