Assessing Global, Regional, and National Time Trends and Associated Risk Factors of the Mortality in Ischemic Heart Disease Through Global Burden of Disease 2019 Study: Population-Based Study.

BACKGROUND: Ischemic heart disease (IHD) is the leading cause of death among noncommunicable diseases worldwide, but data on current epidemiological patterns and associated risk factors are lacking. OBJECTIVE: This study assessed the global, regional, and national trends in IHD mortality and attributable risks since 1990. METHODS: Mortality data were obtained from the Global Burden of Disease 2019 Study. We used an age-period-cohort model to calculate longitudinal age curves (expected longitudinal age-specific rate), net drift (overall annual percentage change), and local drift (annual percentage change in each age group) from 15 to >95 years of age and estimate cohort and period effects between 1990 and 2019. Deaths from IHD attributable to each risk factor were estimated on the basis of risk exposure, relative risks, and theoretical minimum risk exposure level. RESULTS: IHD is the leading cause of death in noncommunicable disease-related mortality (118.1/598.8, 19.7%). However, the age-standardized mortality rate for IHD decreased by 30.8% (95% CI -34.83% to -27.17%) over the past 30 years, and its net drift ranged from -2.89% (95% CI -3.07% to -2.71%) in high sociodemographic index (SDI) region to -0.24% (95% CI -0.32% to -0.16%) in low-middle-SDI region. The greatest decrease in IHD mortality occurred in the Republic of Korea (high SDI) with net drift -6.06% (95% CI -6.23% to -5.88%), followed by 5 high-SDI nations (Denmark, Norway, Estonia, the Netherlands, and Ireland) and 2 high-middle-SDI nations (Israel and Bahrain) with net drift less than -5.00%. Globally, age groups of >60 years continued to have the largest proportion of IHD-related mortality, with slightly higher mortality in male than female group. For period and birth cohort effects, the trend of rate ratios for IHD mortality declined across successive period groups from 2000 to 2004 and birth cohort groups from 1985 to 2000, with noticeable improvements in high-SDI regions. In low-SDI regions, IHD mortality significantly declined in female group but fluctuated in male group across successive periods; sex differences were greater in those born after 1945 in middle- and low-middle-SDI regions and after 1970 in low-SDI regions. Metabolic risks were the leading cause of mortality from IHD worldwide in 2019. Moreover, smoking, particulate matter pollution, and dietary risks were also important risk factors, increasingly occurring at a younger age. Diets low in whole grains and legumes were prominent dietary risks in both male and female groups, and smoking and high-sodium diet mainly affect male group. CONCLUSIONS: IHD, a major concern, needs focused health care attention, especially for older male individuals and those in low-SDI regions. Metabolic risks should be prioritized for prevention, and behavioral and environmental risks should attract more attention to decrease IHD mortality.

An experimental study for quantitative assessment of fatty infiltration and blood flow perfusion in quadriceps muscle of rats using IDEAL-IQ and BOLD-MRI for early diagnosis of sarcopenia.

BACKGROUND: Severe sarcopenia may result in severe disability. Early diagnosis is currently the key to enhancing the treatment of sarcopenia, and there is an urgent need for a highly sensitive and dependable tool to evaluate the course of early sarcopenia in clinical practice. This study aims to investigate longitudinally the early diagnosability of magnetic resonance imaging (MRI)-based fat infiltration and blood flow perfusion technology in sarcopenia progression. METHODS: 48 Sprague-Dawley rats were randomly assigned into six groups that were based on different periods of dexamethasone (DEX) injection (0, 2, 4, 6, 8, 10 days). Multimodal MRI was scanned to assess muscle mass. Grip strength and swimming exhaustion time of rats were measured to assess muscle strength and function. Immunofluorescence staining for CD31 was employed to assess skeletal muscle capillary formation, and western blot was used to detect vascular endothelial growth factor-A (VEGF-A) and muscle ring finger-1 (MuRF-1) protein expression. Subsequently, we analyzed the correlation between imaging and histopathologic parameters. A receiver operating characteristic (ROC) analysis was conducted to assess the effectiveness of quantitative MRI parameters for discriminating diagnosis in both pre- and post-modeling of DEX-induced sarcopenic rats. RESULTS: Significant differences were found in PDFF, R2* and T2 values on day 2 of DEX-induction compared to the control group, occurring prior to the MRI-CSA values and limb grip strength on day 6 of induction and swimming exhaustion time on day 8 of induction. There is a strong correlation between MRI-CSA with HE-CSA values (r = 0.67; p < 0.001), oil red O (ORO) area with PDFF (r = 0.67; p < 0.001), microvascular density (MVD) (r = -0.79; p < 0.001) and VEGF-A (r = -0.73; p < 0.001) with R2*, MuRF-1 with MRI-CSA (r = -0.82; p < 0.001). The AUC of PDFF, R2*, and T2 values used for modeling evaluation are 0.81, 0.93, and 0.98, respectively. CONCLUSION: Imaging parameters PDFF, R2*, and T2 can be used to sensitively evaluate early pathological changes in sarcopenia. The successful construction of a sarcopenia rat model can be assessed when PDFF exceeds 1.25, R2* exceeds 53.85, and T2 exceeds 33.88.

Global, Regional, and National Advances Toward the Management of Rheumatic Heart Disease Based on the Global Burden of Disease Study 2019.

Background Population growth, aging, and major alterations in epidemiologic trends inadvertently modulate the status of rheumatic heart disease (RHD) epidemiology. This investigation predicted RHD burden pattern and temporal trends to provide epidemiologic evidence. Methods and Results Prevalence, mortality, and disability-adjusted life-years data for RHD were obtained from the GBD (Global Burden of Disease) study. We performed decomposition analysis and frontier analysis to assess variations and burden in RHD from 1990 to 2019. In 2019, there were >40.50 million RHD cases worldwide, along with nearly 0.31 million RHD-related deaths and 10.67 million years of healthy life lost to RHD. The RHD burden was commonly concentrated within lower sociodemographic index regions and countries. RHD primarily affects women (22.52 million cases in 2019), and the largest age-specific prevalence rate was at 25 to 29 years in women and 20 to 24 years in men. Multiple reports demonstrated prominent downregulation of RHD-related mortality and disability-adjusted life-years at the global, regional, and national levels. Decomposition analysis revealed that the observed improvements in RHD burden were primarily due to epidemiological alteration; however, it was negatively affected by population growth and aging. Frontier analysis revealed that the age-standardized prevalence rates were negatively linked to sociodemographic index, whereas Somalia and Burkina Faso, with lower sociodemographic index, showed the lowest overall difference from the frontier boundaries of mortality and disability-adjusted life-years. Conclusions RHD remains a major global public health issue. Countries such as Somalia and Burkina Faso are particularly successful in managing adverse outcomes from RHD and may serve as a template for other countries.

A low-cost and portable wrist exoskeleton using EEG-sEMG combined strategy for prolonged active rehabilitation.

Introduction: Hemiparesis is a common consequence of stroke that severely impacts the life quality of the patients. Active training is a key factor in achieving optimal neural recovery, but current systems for wrist rehabilitation present challenges in terms of portability, cost, and the potential for muscle fatigue during prolonged use. Methods: To address these challenges, this paper proposes a low-cost, portable wrist rehabilitation system with a control strategy that combines surface electromyogram (sEMG) and electroencephalogram (EEG) signals to encourage patients to engage in consecutive, spontaneous rehabilitation sessions. In addition, a detection method for muscle fatigue based on the Boruta algorithm and a post-processing layer are proposed, allowing for the switch between sEMG and EEG modes when muscle fatigue occurs. Results: This method significantly improves accuracy of fatigue detection from 4.90 to 10.49% for four distinct wrist motions, while the Boruta algorithm selects the most essential features and stabilizes the effects of post-processing. The paper also presents an alternative control mode that employs EEG signals to maintain active control, achieving an accuracy of approximately 80% in detecting motion intention. Discussion: For the occurrence of muscle fatigue during long term rehabilitation training, the proposed system presents a promising approach to addressing the limitations of existing wrist rehabilitation systems.

Assessment of association between the carotid web and dissection in spontaneous internal carotid artery dissection patients using vessel wall MRI.

BACKGROUND: Internal carotid artery dissection (ICAD) is the major cause of ischemic stroke in young to middle-aged people. Recognition of predisposing factors may facilitate in early individual risk prediction and expand treatment. PURPOSE: To evaluate the association between a carotid web and dissection in patients with ICAD using vessel wall magnetic resonance imaging (VW-MRI). MATERIAL AND METHODS: A retrospective study was conducted of 223 patients who underwent VW-MRI. Of these patients, 58 patients with craniocervical artery dissection (CCAD) (33 ICAD and 25 vertebrobasilar artery dissection [VBAD]) were included. The control group (n = 165) consisted of patients without arterial dissection who had undergone VW-MRI . The presence of a carotid web in the posterior aspect of carotid bulb was recorded. The distance between the carotid web and start of dissection in ICA was recorded. RESULTS: The presence of a carotid web showed a significant difference between the ICAD, VBAD, and control groups (19 [57.6%] vs. 5 [20%] vs. 36 [21.8%], respectively; P < 0.001). In multi-nominal analysis, the presence of a carotid web showed a significant difference between the ICAD and VBAD groups and the ICAD and control groups (P < 0.05), with odds ratios of 5.41 (95% confidence interval [CI]=1.634-17.973) and 4.81 (95% CI=2.176-10.651), respectively. Out of 19 ICAD patients with carotid web, 16 had occurrence of dissection in the C1 segment of the ICA with a mean distance of 1.91 ± 1.71 cm from the carotid web. CONCLUSION: Presence of a carotid web was more frequent in patients with ICAD. The carotid web may be one of the predisposing factors for development of dissection in patients with ICAD.

Spatial Pattern and Fairness Measurement of Educational Resources in Primary and Middle Schools: A Case Study of Chengdu-Chongqing Economic Circle.

China's education has developed rapidly in recent years, but the issue of educational equality still exists. Currently, there are few studies on educational resources, and their spatial pattern and fairness remain unclear. Thus, this study selected the point of interest data and spatial analysis methods to depict the spatial pattern of educational resources (containing the number of teachers, students, facilities, etc.). Then, we evaluated the equity of educational resources (including the number of schools and school teachers) in terms of geographic and population distribution by combining statistical yearbook data with two indices (the index of dissimilarity and agglomeration degree) to promote healthy urban development. The results show the following. (1) Educational resources have a multicenter spatial structure of "dual cores and multiple sub-centers". The Moran index reflects a weak positive spatial correlation between educational resources. (2) The index of dissimilarity is between 0.02 and 0.21, which shows that the allocation of resources is relatively balanced. Regarding internal units, obvious differences exist in the agglomeration degree and equilibrium of educational resources.

[Pollution Characteristics and Risk Assessment of Heavy Metals in the Bioretention Systems of Sponge Cities].

As an important water purification and seepage measure for sponge cities, biofiltration systems have been widely used in their construction in China. In order to identify the heavy metal accumulation, pollution, and its potential environmental risk in the biofiltration systems, this study examined the heavy metal contents and spatial distribution characteristics by taking the biofiltration systems of Yuelai new town, Chongqing, the first demonstration area of sponge city construction in China, as the research object, and conducted a risk evaluation of the pollution level and ecological environment in this new town using the contamination factor (CF), geo-accumulation Index (Igeo), and potential ecological risk coefficient (PERC). The results showed that, except for Mn, the average contents of Cu, Zn, Pb, Ni, and Cd in the biofiltration systems of Yuelai new town were 4.14, 1.77, 4.98, 1.23, and 6.51 times higher than the soil background values of Chongqing. In terms of spatial distribution, the contents of heavy metals in biofiltration systems along the roads in different functional areas showed great differences. The contents of Cu, Zn, Mn, Pb, Ni, and Cd in the industrial area were significantly higher than those of the same types of heavy metals in the biofiltration systems in other areas (P<0.05). The CF and Igeo showed that the pollution level of heavy metals was ranked as follows:Mn

Assessment of bone densitometry using radiography with a step-wedge phantom: a pilot study of the forearm.

Background: Radiographic absorptiometry (RA) is one of the earliest methods of bone densitometry and has been used to measure the phalanges and metacarpals where soft tissue attenuation is minimal. The aim of this study was to determine whether the technique can be adapted to correct for soft tissue attenuation and measure areal bone mineral density (aBMD) in the forearm. Methods: A total of 51 patients referred for a clinical spine and hip dual-energy X-ray absorptiometry (DXA) examination and 8 young and middle-aged volunteers were recruited to this study. The first 29 participants (20 women, 9 men, aged 61±14 years) served as the training cohort, and the remaining 30 (20 women, 10 men, aged 55±16 years) comprised the validation cohort. All participants underwent a DXA scan of their non-dominant forearm, and a digital X-ray image of the same arm was acquired with a step phantom. Identical regions of interest (ROIs) in the radius and ulna at the one-third radius site were measured on the X-ray and DXA images, and a soft tissue ROI was measured on X-ray images between the radius and ulna. The X-ray measurements in the training cohort were expressed as equivalent step phantom thickness (Eq. SPT) and used to estimate forearm aBMD using a linear equation calibrated against the DXA scans. Estimates of forearm aBMD made from the digital X-ray images acquired in the validation cohort were compared with the results of the DXA scans. Results: Digital X-ray estimates of radius and ulna aBMD at the one-third radius site in the validation cohort showed a good correlation with GE-Lunar iDXA scanner measurements (r=0.795; P<0.001). The Bland-Altman plot had a mean bias of -0.002 g/cm2 and 95% limits of agreement of -0.185 to +0.181 g/cm2. Conclusions: Digital X-ray estimates of proximal forearm aBMD corrected for soft tissue attenuation correlated with DXA measurements with correlation coefficients comparable to those seen for other peripheral bone densitometry technologies.

Impact of a G-CSF Policy to Reduce Low-Value Care on Guideline Adherence and Mortality.

PURPOSE: Practice guidelines recommend the prophylactic use of granulocyte colony-stimulating factors (G-CSFs) in patients with high risk of febrile neutropenia, but evidence suggests that G-CSFs are frequently overused. The objectives of this study were (1) to determine the prevalence and prescribing patterns of G-CSF and (2) to evaluate the impact of a program initiative on G-CSF prescribing patterns, adherence to guidelines, and mortality. METHODS: In this retrospective cohort study, data were used from the electronic health records of patients with metastatic colorectal cancer who received care at a multicenter oncology practice network during two time periods: July 01, 2013, to December 31, 2014, and July 01, 2017, to December 31, 2017. Beginning 2016, a site-wide program initiative that involved educational materials, appropriate nonuse recommendations, and prior authorization was introduced in the oncology practice network with an aim of reducing G-CSF overutilization. Descriptive statistics, t tests, and chi-squared tests were employed to analyze program impact. RESULTS: There were 3,426 chemotherapy regimens corresponding to 2,968 patients. There were a total of 387 (11.3%) G-CSF-treated patients and 3,095 G-CSF administrations during the study period. G-CSF use was significantly lower in the postperiod, compared with the preperiod (P < .0001). Adherence to guidelines was significantly higher in the postperiod, compared with the preperiod (P < .0001). Mortality rates did not significantly differ between the two time periods. CONCLUSION: This study demonstrates that policy initiatives have the potential to positively affect G-CSF prescription patterns and promote guideline adherence. These findings could help prescribers adopt a cost-effective approach in patients with metastatic colorectal cancer, leading to enhanced clinical practice and value-based care.

Application of Distributed Parameter Model to Assessment of Glioma IDH Mutation Status by Dynamic Contrast-Enhanced Magnetic Resonance Imaging.

Previous studies using contrast-enhanced imaging for glioma isocitrate dehydrogenase (IDH) mutation assessment showed promising yet inconsistent results, and this study attempts to explore this problem by using an advanced tracer kinetic model, the distributed parameter model (DP). Fifty-five patients with glioma examined using dynamic contrast-enhanced imaging sequence at a 3.0 T scanner were retrospectively reviewed. The imaging data were processed using DP, yielding the following parameters: blood flow F, permeability-surface area product PS, fractional volume of interstitial space Ve, fractional volume of intravascular space Vp, and extraction ratio E. The results were compared with the Tofts model. The Wilcoxon test and boxplot were utilized for assessment of differences of model parameters between IDH-mutant and IDH-wildtype gliomas. Spearman correlation r was employed to investigate the relationship between DP and Tofts parameters. Diagnostic performance was evaluated using receiver operating characteristic (ROC) curve analysis and quantified using the area under the ROC curve (AUC). Results showed that IDH-mutant gliomas were significantly lower in F (P = 0.018), PS (P < 0.001), Vp (P < 0.001), E (P < 0.001), and Ve (P = 0.002) than IDH-wildtype gliomas. In differentiating IDH-mutant and IDH-wildtype gliomas, Vp had the best performance (AUC = 0.92), and the AUCs of PS and E were 0.82 and 0.80, respectively. In comparison, Tofts parameters were lower in K trans (P = 0.013) and Ve (P < 0.001) for IDH-mutant gliomas. No significant difference was observed in Kep (P = 0.525). The AUCs of K trans, Ve, and Kep were 0.69, 0.79, and 0.55, respectively. Tofts-derived Ve showed a strong correlation with DP-derived Ve (r > 0.9, P < 0.001). K trans showed a weak correlation with F (r < 0.3, P > 0.16) and a very weak correlation with PS (r < 0.06, P > 0.8), both of which were not statistically significant. The findings by DP revealed a tissue environment with lower vascularity, lower vessel permeability, and lower blood flow in IDH-mutant than in IDH-wildtype gliomas, being hostile to cellular differentiation of oncogenic effects in IDH-mutated gliomas, which might help to explain the better outcomes in IDH-mutated glioma patients than in glioma patients of IDH-wildtype. The advantage of DP over Tofts in glioma DCE data analysis was demonstrated in terms of clearer elucidation of tissue microenvironment and better performance in IDH mutation assessment.

Effective methods for reactivating inactive blood donors: a stratified randomised controlled study.

BACKGROUND: Recruiting of sufficient numbers of donors of blood products is vital worldwide. In this study we assessed the efficacy and cost-effectiveness of telephone calls and SMS reminders for re-recruitment of inactive blood donors. METHODS: This single-centre, non-blinded, parallel randomised controlled trial in Guangzhou, China included 11,880 inactive blood donors whose last donation was between January 1 and June 30, 2014. The donors were randomly assigned to one of two intervention groups (telephone call or short message service [SMS] communications) or to a control group without intervention. SMS messages with altruistic appeal were adopted in the SMS group; in addition to altruistic appeal, reasons for deferral of blood donation were also asked in the telephone group. All participants were followed up for 1 year. The primary outcome was re-donation rate, and rates in different groups were compared by intention-to-treat (ITT) analysis and estimation of the average treatment effect on the treated (ATT). Secondary outcomes were the self-reported deterrents. Other outcomes included the re-donation interval, and the incremental cost-effectiveness ratio (ICER) of telephone calls and SMS reminders on re-recruitment. RESULTS: ITT analysis revealed no significant differences in the re-donation rate among the three groups. ATT estimations indicated that among compliers, telephone calls significantly increased re-donation compared to both SMS reminders and no intervention. Donor return behaviour was positively associated with receiving reminders successfully, being male, older age, and previous donation history. The SMS reminder prompted donors to return sooner than no reminder within 6 months, and according to ICER calculations, SMS reminders were more cost-effective than telephone calls. Donors reported time constraints as the most main causes of self-deferral in the telephone group, and altruistic appeal had a positive effect on these donors. CONCLUSIONS: Interventions to reactivate inactive blood donors can be effective, with telephone calls prompting more donors to return but at a greater cost than SMS messages. SMS reminder with altruistic appeal can urge donors to re-donate sooner within 6 months than no reminder. TRIAL REGISTRATION: NCT03366441 (Reactivation of Inactive Blood Donors). Retrospectively registered 4 December 2017.

Assessment of lumbar paraspinal muscle activation using fMRI BOLD imaging and T2 mapping.

BACKGROUND: Our study aimed to investigate the feasibility of functional magnetic resonance imaging [blood oxygen level-dependent (BOLD) imaging and T2 mapping] in monitoring the activation of lumbar paraspinal muscles before and after exercise. METHODS: The ethics committee of the First Affiliated Hospital of Kunming Medical University approved our study. Both BOLD and T2 mapping of paraspinal muscles were performed in 50 healthy, young volunteers before and after upper-body extension exercises. The movement tasks included upper body flexion and extension using a simple Roman chair. Cross-sectional area (CSA), R2*, and T2 values were measured in various lower-back anatomical regions. The SPSS22.0 statistical software was used to analyze all the data. RESULTS: Post-exercise CSA and T2 values were higher than those recorded in the pre-exercise session for the three lower-back muscles that were evaluated (iliocostalis, longissimus, and multifidus) (P<0.01). However, R2* values of these muscles were significantly lower after exercise (P<0.01). A significant difference in the R2*, CSA, and T2 values of the iliocostalis occurred between males and females (P<0.05). No statistically significant differences were evident for R2*, CSA, and T2 of the lower-back muscles between L3 and L4 levels, or between the left and right sides. The total CSA of the iliocostalis was higher than that of the multifidus and longissimus (P<0.05). CONCLUSIONS: BOLD and T2 mapping are feasible non-invasive indirect assessments of lumbar paraspinal muscle activation before and after exercise.

[Spatial Distribution and Risk Assessment of Heavy Metals in Soils from a Typical Urbanized Area].

With the rapid urbanization in China, soil environments are facing high risks. Taking a typical urbanized area as a case study, a total of 106 surface soil samples (0-20 cm) and 96 subsurface soil samples (20-40 cm) were collected to determine the concentrations of heavy metals, and then, the Nemerow index and Hankson index methods were used to evaluate their degrees of ecological risk. The spatial distributions of ecological risks were also explored. Experimental results showed that the concentrations of Cr, Ni, Cu, Zn, As, Cd, Pb, and Hg in surface soil samples were 2.87-84.64, 1.40-56.00, 2.75-125.05, 15.05-201.39, 1.46-89.92, 0.001-0.92, 15.29-160.07, and 0.006-0.52 mg·kg-1, respectively, and those in subsurface soil samples were 3.56-75.14, 1.65-71.58, 3.28-290.04, 17.99-296.94, 3.07-65.67, 0.02-1.00, 11.10-97.59, and 0.01-0.41 mg·kg-1, respectively. According to the risk control standards for soil contamination of agricultural land, approximately 71.70%, 40.57%, 4.72%, 3.77%, and 0.94% of Cd, Cu, Pb, As, and Zn, respectively, in the surface soil samples exceeded the standards, while 72.92%, 39.58%, 6.25%, 3.13%, 3.13%, and 1.04% of Cd, Cu, As, Zn, Pb, and Ni, respectively, in the subsurface soil samples exceeded the standards. Obviously, the pollution by Cd and Cu was the most severe in the research area, and the main contaminated areas were distributed in the northern part of the land. The soil environmental quality pollution assessment illustrated that high risk areas were distributed in the northern part of the research area too. The risk assessment results indicated that the main pollution factor was Cd, which is accordance with the serious pollution findings for Cd. In response to these results, effective management and remediation methods should be taken to control the soil environment pollution in this typical urbanized area.

Joint modeling of multivariate longitudinal measurements and survival data with applications to Parkinson's disease.

In many clinical trials, studying neurodegenerative diseases including Parkinson's disease (PD), multiple longitudinal outcomes are collected in order to fully explore the multidimensional impairment caused by these diseases. The follow-up of some patients can be stopped by some outcome-dependent terminal event, e.g. death and dropout. In this article, we develop a joint model that consists of a multilevel item response theory (MLIRT) model for the multiple longitudinal outcomes, and a Cox's proportional hazard model with piecewise constant baseline hazards for the event time data. Shared random effects are used to link together two models. The model inference is conducted using a Bayesian framework via Markov Chain Monte Carlo simulation implemented in BUGS language. Our proposed model is evaluated by simulation studies and is applied to the DATATOP study, a motivating clinical trial assessing the effect of tocopherol on PD among patients with early PD.

[Analysis of projects funded by NSFC in field of processing Chinese materia medica in recent five years].

The general situation of the approved and concluded projects of National Natural Science Foundation of China in the field of processing Chinese Materia Medica in recent five years has been reviewed. The progresses and achievements of some projects have been summarized in accordance with research area such as the processing principle, the processing technology, quality evaluation, toxicity and safety evaluation, etc. The researchers and project support units of the funded projects have been analyzed, and the problems of the applications have been also summarized.

Shape-coded silica nanotubes for multiplexed bioassay: rapid and reliable magnetic decoding protocols.

AIMS: The recent development of 1D barcode arrays has proved their capabilities to be applicable to highly multiplexed bioassays. This article introduces two magnetic decoding protocols for suspension arrays of shape-coded silica nanotubes to process multiplexed assays rapidly and easily, which will benefit the minimization and automation of the arrays. METHODS: In the first protocol, the magnetic nanocrystals are incorporated into the inner voids of barcoded silica nanotubes in order to give the nanotubes magnetic properties. The second protocol is performed by trapping the barcoded silica nanotubes onto streptavidin-modified magnetic beads. RESULTS: The rapid and easy decoding process was demonstrated by applying the above two protocols to multiplexed assays, resulting in high selectivity. Furthermore, the magnetic bead-trapped barcode nanotubes provided a great opportunity to exclude the use of dye molecules in multiplexed assays by using barcode nanotubes as signals. CONCLUSION: The rapid and easy manipulation of encoded carriers using magnetic properties could be used to develop promising suspension arrays for portable bioassays.

Assessment of immunoreactive synthetic peptides from the structural proteins of severe acute respiratory syndrome coronavirus.

BACKGROUND: The widespread threat of severe acute respiratory syndrome (SARS) to human life has spawned challenges to develop fast and accurate analytical methods for its early diagnosis and to create a safe antiviral vaccine for preventive use. Consequently, we thoroughly investigated the immunoreactivities with patient sera of a series of synthesized peptides from SARS-coronavirus structural proteins. METHODS: We synthesized 41 peptides ranging in size from 16 to 25 amino acid residues of relatively high hydrophilicity. The immunoreactivities of the peptides with SARS patient sera were determined by ELISA. RESULTS: Four epitopic sites, S599, M137, N66, and N371-404, located in the SARS-coronavirus S, M, and N proteins, respectively, were detected by screening synthesized peptides. Notably, N371 and N385, located at the COOH terminus of the N protein, inhibited binding of antibodies to SARS-coronavirus lysate and bound to antibodies in >94% of samples from SARS study patients. N385 had the highest affinity for forming peptide-antibody complexes with SARS serum. CONCLUSIONS: Five peptides from SARS structural proteins, especially two from the COOH terminus of the N protein, appear to be highly immunogenic and may be useful for serologic assays. The identification of these antigenic peptides contributes to the understanding of the immunogenicity and persistence of SARS coronavirus.