Hyponatremia Is Associated with Mortality in Acute Pancreatitis Patients.

BACKGROUND: Disorders of serum sodium are common among general patients and are associated with poor outcomes. The prognostic value of serum sodium disorders in patients with acute pancreatitis (AP) has not been studied. We conducted this retrospective study to explore the association between serum sodium levels and the outcomes of patients with AP. MATERIALS AND METHODS: Patients with AP from the Medical Information Mart for Intensive Care III (MIMIC-III) were screened for this study. The laboratory variables, including serum sodium levels, were obtained by analyzing the first blood sample on the first day after admission. Univariate logistic regression was performed to discover potential factors for mortality of AP. The unadjusted and adjusted association between serum sodium level and mortality of AP was shown by the restricted cubic spline (RCS). The categorical cutoff for the detrimental effect of serum sodium level on the prognosis of AP was also confirmed by stepwise logistic regression after adjusting for con-founding effects of significant factors in the univariate logistic regression. RESULTS: A total of 869 patients with AP in the MIMIC-III were included with a mortality of 13.1%. Unadjusted logistic regression showed that age (p < 0.001), simplified acute physiological score (SAPS) (p < 0.001), systolic blood pressure (p < 0.001), diastolic blood pressure (p < 0.001), hemoglobin (p = 0.040), serum creatinine (p = 0.046), and serum phosphorus (p < 0.001) were significantly associated with the mortality of AP. The RCS showed that the serum sodium level was negatively and linearly associated with mortality of AP after adjusting for confounding effects of significant factors in the univariate logistic regression. Serum sodium < 133 mmol/L, which indicated hyponatremia, was significantly correlated with a higher mortality risk than serum sodium ≥ 133 mmol/L (p = 0.013). CONCLUSIONS: Hyponatremia is widely developed among patients with AP and correlates with a higher mortality risk of AP. Physicians should pay more attention to managing patients with AP with hyponatremia.

A review regarding the article 'Health inequalities in cardiopulmonary resuscitation and use of automated electrical defibrillators in out-of-hospital cardiac arrest'.

Out-of-hospital cardiac arrest (OHCA) is a major cause of mortality worldwide, with a high incidence and low survival rate. Prompt cardiopulmonary resuscitation (CPR) and automated external defibrillator (AED) use are major contributors in the "chain of survival" for OHCA. the response of a community plays a key role in determining the outcomes in OHCA. The outcomes of OHCA are affected by health inequalities in bystander CPR and AED use, due to factors such as differences in sex, ethnicity, and socioeconomic status amongst others. Literature shows patients from lower socio-economic backgrounds are more likely to have risk factors for a cardiac arrest and are therefore more likely to have OHCA. Studies have also reported lower rates of bystander AED use in females compared to males. Targeting deprived areas with tailored training and access to AEDs can be beneficial in improving CPR outcomes in communities. Due to the physical nature of CPR maneuvers, age and frailty of the patient can both impact the outcome of the resuscitation. Environmental factors affecting AED use include availability, visibility, accessibility, support, extra equipment, training materials, staffing, and awareness. Education should focus on areas such as conducting BLS on both male and female patients, recognizing cardiac arrest, tailoring BLS to difference ages as well as provision for training in different languages, including sign language. Like some other countries, CPR training is now being implemented in the school curriculum.

Effect of hydrocolloid dressing on pressure ulcer in patients with non-invasive positive pressure ventilation: A meta-analysis.

This study systematically evaluated the effect of hydrocolloid dressings on facial pressure ulcers in patients receiving non-invasive positive pressure ventilation (NIPPV). The Embase, PubMed, Cochrane Library, CNKI, VIP, Chinese Biomedical Literature Database and Wanfang databases were searched for randomised controlled trials on the use of hydrocolloid dressings in patients receiving NIPPV published from the inception of each database to August 2023. The literature was independently screened, data were extracted by two authors based on the inclusion and exclusion criteria, and the quality of the included literature was assessed. The meta-analysis was performed using Stata 17.0. Thirteen studies including 1248 patients were included, with 639 patients in the intervention group and 609 patients in the control group. Meta-analysis showed that the hydrocolloid dressing significantly reduced the incidence of facial pressure ulcers in patients with NIPPV (odds ratio = 0.16, 95% confidence intervals: 0.11-0.24, p < 0.001). Hydrocolloid dressings are effective in reducing the incidence of facial pressure ulcers in patients receiving NIPPV. However, because of the small number of included studies, this conclusion needs to be confirmed with larger samples and high-quality clinical studies.

Impact of peripherally inserted central venous catheter-associated phlebitis in neonate guided by intracavitary electrocardiogram: A systematic review and meta-analysis of randomised controlled trials.

Because the application of intracavitary electrocardiogram (IC-ECG)-guided peripherally inserted central catheter (PICC) in the treatment of neonates is controversial in terms of phlebitis reduction compared with traditional X-ray positioning technique, a systematical evaluation is needed on the impact of IC-ECG on this common complication following PICC. Literature retrieval was conducted on large databases including PubMed, Google Scholar, Cochrane library, and CNKI. Randomised controlled trials (RTCs) of intracavitary electrocardiogram-guided peripherally inserted central catheter tip placement in the treatment of neonates up to July 7, 2022, were collected. Then indicators of included studies were compared and analysed by two researchers. Meta-analysis was performed on the STATA 17.0 software. After excluding invalid trials, 11 out of 316 randomised controlled trials were included for further analysis. Meta-analysis results showed that compared with the control group, IC-ECG-guided PICC could decrease the incidence of phlebitis (I2  = 0.00%, P = 0.76, OR = 0.33, 95% CI 0.19-0.56) and that no significant difference was observed between preterm neonates and term neonates (P = 0.74). Meanwhile, total complications were decreased in neonates (I2  = 0.00%, P = 0.00 OR = 0.23, 95% CI 0.16-0.33). IC-ECG-guided PICC could also improve the accuracy of optimal tip location (I2  = 0.00%, P = 0.53, OR = 5.37, 95% CI 3.80-7.59). IC-ECG-guided PICC could achieve reduced phlebitis incidence and total complications in the treatment of neonates, as well as increased accuracy of optimal tip location, no matter if those neonates were preterm or not. This study was registered in inplasy.com with No. INPLASY202280012 (DOI: 10.37766/inplasy2022.8.0012).

Urgent recommendation and practice of prevention and control of novel coronavirus disease 2019 (COVID-19) in intensive care units in West China Hospital of Sichuan University during the epidemics / 中国胸心血管外科临床杂志

@#Objective    To provide recommendations for the management of intensive care unit patients without novel coronavirus disease 2019 (COVID-19). Methods    We set up a focus group urgently and identified five key clinical issues through discussion. Total 23 databases or websites including PubMed, National Guideline Clearing-House, Chinese Center for Disease Control and Prevention and so on were searched from construction of the library until February 28, 2020. After group discussion and collecting information, we used GRADE system to classify the evidence and give recommendations. Then we apply the recommendations to manage pediatric intensive care unit in the department of  critical care medicine in our hospital. Results    We searched 13 321 articles and finally identified 21 liteteratures. We discussed twice, and five recommendations were proposed: (1) Patients should wear medical surgical masks; (2) Family members are not allowed to visit the ward and video visitation are used; (3) It doesn’t need to increase the frequency of environmental disinfection; (4) We should provide proper health education about the disease to non-medical staff (workers, cleaners); (5) Medical staff do not need wear protective clothing. We used these recommendations in intensive care unit management for 35 days and there was no novel coronavirus infection in patients, medical staff or non-medical staff. Conclusion    The use of evidence-based medicine for emergency recommendation is helpful for the scientific and efficient management of wards, and is also suitable for the management of general intensive care units in emergent public health events.

SCF promotes the production of IL-13 via the MEK-ERK-CREB signaling pathway in mast cells.

Mast cells serve a key role in the occurrence and development of allergy. As an important growth factor of mast cells, stem cell factor (SCF) has an effect on the apoptosis, chemotaxis, adhesion, degranulation and other biological characteristics of mast cells. However, there are few studies regarding the effect of SCF signal on the production of cytokines from mast cells, particularly Th2 type cytokines. In the present study, the expression and secretion of IL-13 in P815 cells stimulated by SCF were detected by fluorescence quantitative PCR and ELISA, and western blotting and EMSA were used to detect ERK phosphorylation and activation of CREB in stimulated P815 cells. The results demonstrated that the production of IL-13 was significantly increased in P815 cells stimulated by SCF (1-100 ng/ml; P<0.01). There was an obvious phosphorylation of ERK and CREB activation in P815 cells stimulated by SCF (50 ng/ml). Compared with the SCF single stimulation group, the production of IL-13 was significantly reduced in P815 cells stimulated with U0126 (ERK-MEK/pathway inhibitor) or H-89 (CREB inhibitor) combined with SCF stimulation group (P<0.01). However, JSI-124 (JAK/STAT3 pathway inhibitor), Wortmannin (PI3K/Akt pathway inhibitor) and PDTC (NF-κB inhibitor) had no effect on the role of SCF promoting the P815 cells producing IL-13. Therefore, SCF signaling promotes mast cell P815 to produce IL-13, and this effect is associated with the MEK-ERK-CREB signaling pathway.

MicroRNA-20b promotes proliferation of H22 hepatocellular carcinoma cells by targeting PTEN.

MicroRNAs (miRNAs/miRs) are small, noncoding RNA molecules that are closely associated with the occurrence and development of tumors. miR-20b is overexpressed in hepatocellular carcinoma cell lines and tissues. However, it is not clear whether miR-20b can promote the proliferation of hepatocellular carcinoma cells. In the present study, the proliferation of H22 mouse hepatocellular carcinoma cells was detected using the Cell Counting Kit-8 assay. MiRanda software was used to predict the binding sites of miR-20b to the 3'-untranslated region (3'-UTR) of phosphatase and tensin homolog (PTEN). The 3'-UTR sequence of the PTEN gene was amplified using the polymerase chain reaction in H22 cells. The recombinant plasmid or empty plasmid was co-transfected with miR-20b mimics or miR-20b scramble into HeLa cells, and luciferase activity was assessed by Dual-Luciferase® Reporter Assay System 24 h post-transfection. In the present study, miR-20b knockdown significantly inhibited the proliferation of H22 mouse hepatocellular carcinoma cells. In addition, miR-20b inhibition upregulated the expression of PTEN, and it was revealed that miR-20b may directly target the 3'-untranslated region of the PTEN gene. Downregulation of PTEN partially reversed the anti-proliferative effect of miR-20b on H22 cells. In conclusion, miR-20b may promote H22 cell proliferation by targeting PTEN, providing a rationale for further study investigating novel therapeutic strategies for liver cancer.

IGF-1 Promotes Endocytosis of Alveolar Epithelial Cells through PI3K Signaling.

Airway inflammation can be mitigated when apoptotic cells are engulfed by pulmonary epithelial cells. Insulin-like growth factor 1 (IGF-1), a single chain polypeptide growth factor, is the main mediator of growth hormone activity in vivo. IGF-1 has many biological activities, such as the regulation of cell survival, proliferation, differentiation and metabolism. However, its effect on the engulfment of cells, especially by non-professional phagocytes such as alveolar epithelial cells (AECs), has not been fully elucidated. We report that IGF-1 increases endocytosis in a mouse alveolar epithelial cell line, MLE-12. The PI3K-Akt pathway is involved in this effect of IGF-1. Furthermore, IGF-1 can inhibit the production of interleukin-6 in lipopolysaccharide-stimulated AECs. We have found that IGF-1 can enhance endocytosis of AECs through the PI3K pathway and exhibit anti-inflammatory properties. These two observations suggest that IGF-1 is a potential mediator in the regulation of airway inflammation.

The identification research of emergency treatment technology for sudden heavy metal pollution accidents in drainage basin based on D-S evidence theory.

As a sudden heavy metal pollution accident occurs in a drainage basin, decision makers need to quickly select the optimal emergency treatment technology and formulate emergency schemes according to the actual accident characteristics. Therefore, a two-step identification method of emergency treatment technology for sudden heavy metal pollution accidents based on Dempster-Shafer (D-S) evidence theory is proposed, in order to screen the optimal emergency treatment technology effectively and solve the conflict among fusion data in the process of index quantification. Firstly, the available technologies were screened preliminarily by the primary identification indexes (technical characteristic indexes). Secondly, the weight synthesis method based on the D-S evidence theory and attribute assignment was utilized to score the secondary identification indexes (technical evaluation indexes) of each available technology comprehensively. Finally, the optimal emergency treatment technology for this sudden pollution accident was obtained. Taking the sudden arsenic pollution accident of the Picang flood diversion channel in Linyi, Shandong Province as an example, the activated alumina adsorption dam technology was extracted successfully, which is in accordance with the actual treatment situation. The result shows that the method has strong feasibility and practicability, which can provide strong decision support for dealing with sudden pollution accidents in drainage basins efficiently.

miR­20b negatively regulates VEGF expression by targeting STAT3 in H22 hepatocellular carcinoma cells.

Vascular endothelial growth factor (VEGF) promotes angiogenesis during tumor growth, and its expression involves multiple signaling pathways and transcription factors. In the present study, transforming growth factor (TGF)­ß1 promoted upregulation of VEGF and downregulation of microRNA (miR)­20b expression in mouse H22 hepatocellular carcinoma cells. miR­20b negatively regulated both constitutive VEGF expression and TGF­ß1­induced VEGF expression. The miRanda algorithm predicted that a binding site of the miR­20b GCAAUCUGGGCACUUU sequence was present in the signal transducer and activator of transcription (STAT)3 3'­untranslated region. Following transfection of miR­20b mimics into H22 cells, expression of STAT3 protein was downregulated. A dual­luciferase activity assay revealed that miR­20b directly targeted STAT3 to regulate its expression, and that interference with STAT3 expression significantly downregulated VEGF mRNA and protein expression. Interference with STAT3 expression resulted in increased VEGF expression in H22 cells overexpressing miR­20b, but expression was lower than that in quiescent H22 cells. This indicated that STAT3 was involved in the negative regulation of VEGF expression in H22 cells by miR­20b. The data demonstrated that miR­20b negatively regulated VEGF expression by directly targeting STAT3 in H22 cells.

The Effect of Diagnostic Blood Loss on Anemia and Transfusion Among Postoperative Patients With Congenital Heart Disease in a Pediatric Intensive Care Unit.

PURPOSE: To evaluate whether diagnostic blood loss can lead to anemia and consequent blood transfusion among postoperative patients with congenital heart disease (CHD) in the pediatric intensive care unit (PICU). DESIGN AND METHODS: This prospective observational study was conducted in a university-affiliated tertiary hospital between January and August 2016. CHD patients aged <12years, undergoing cardiac surgery, with a PICU stay >48h were included (n=205). Multivariate logistic regression analyses were used to determine the effect of diagnostic blood loss on anemia and transfusion. RESULTS: The mean daily phlebotomy volume was 5.40±1.94mL/d during the PICU stay (adjusted for body weight, 0.63±0.36mL/kg/d). Daily volume/kg was associated with cyanotic CHD, Pediatric Risk of Mortality III score, and Pediatric Logistic Organ Dysfunction (PELOD)-2 score. In total, 101 (49.3%) patients presented with new or more severe anemia after admission to PICU, which was not associated with phlebotomy volume. Forty-one (20.0%) children received one or more RBC transfusions during their PICU stay. Multivariate analysis indicated that PELOD-2 score>5, new or more severe anemia, and daily volume/kg of phlebotomy >0.63mL/kg/d were significantly associated with transfusion after 48h of admission to PICU. CONCLUSIONS: Our findings indicate that diagnostic blood loss is not related to postoperative anemia in children with CHD; however, this factor does correlate with blood transfusion, since it somewhat reflects the severity of illness. PRACTICE IMPLICATIONS: Strategies should be applied to reduce diagnostic blood loss, as appropriate.

Sp-1 Negatively Regulates miR-20b Expression in Macrophages.

miR-20b is a member of the miR-106a-363 gene cluster, located on the X chromosome. miR-20b regulates the expression of multiple genes in vivo and it is closely related to the occurrence and development of many diseases. These diseases include inflammatory diseases and tumor development, amongst others. However, few studies have focused on the regulation of the miR-20b gene itself. In this study, we are using the miRBase database to obtain the upstream 2000 bp sequence of the miR-20b precursor. Bio-informatics software P-MATCH 1.0 and AliBaba2 werethen used to predict transcription factor binding in the upstream region. Sp-1 was identified as one of the most probable transcription factors regulating miR-20b gene expression. After treatment with a Sp-1 siRNA, the expression of miR-20b was significantly increased in RAW264.7 cells, as well as peritoneal and alveolar macrophages. In addition, the interference with Sp-1 gene expression also reversed the decrease in miR-20b expression in RAW264.7 cells induced by TNF-α. These results indicate that Sp-1 negatively regulates the expression of miR-20b in macrophages. This finding suggests the potential of Sp-1 as a target for therapies in diseases that are associated with miR-20b overexpression.

MicroRNA-20b promotes the accumulation of CD11b+Ly6G+Ly6Clow myeloid-derived suppressor cells in asthmatic mice.

miR-20b is a member of the miR-106a-363 gene cluster, which has been shown to play an important role in a variety of diseases, including cancer, inflammation, and autoimmune diseases. Our previous study indicated that miR-20b has an inhibitory effect on airway inflammation in asthmatic mice, but the exact mechanism is unclear. In this study, we report that the ratio of CD11b+Ly6G+Ly6Clow cells, but not the amount of CD11b+Ly6C+Ly6G- cells, was increased in the lung tissue of asthmatic mice after intranasal instillation with miR-20b mimics, while Th2-type cytokines (interleukin (IL)-4 and IL-13) were significantly decreased in the bronchoalveolar lavage fluid. In addition, the transcription factor CREB regulated the expression of miR-20b. Our findings suggest that miR-20b can induce the accumulation of myeloid-derived suppressor cells in the lungs of asthmatic mice, which may be a mechanism by which miR-20b inhibits airway inflammation in asthmatic mice. Thus, miR-20b may be used as a target for the effective treatment of asthma in the future.

Mir-20b-Induced Increase in Myeloid-Derived Suppressor Cells in the Lungs of Mice with Chronic Asthma.

Bronchial asthma is a common chronic airway inflammatory disease. MicroRNAs (miRNAs) play an important role in the pathogenesis of asthma. We have previously shown that miR-20b can inhibit airway inflammation in asthmatic mice, but the exact mechanism is unknown. In the present study, we show that administration of nasal drops containing miR-20b induced an increase in the percentage of Gr1+CD11b+ myeloid-derived suppressor cells (MDSCs) in lung tissue from asthmatic mice, and the content of TGF-ß in lung tissues also increased after treatment. However, there was no significant change in the number of Gr1+CD11b+ MDSCs in bone marrow, peripheral blood, or spleens of asthmatic mice receiving the miR-20b nasal drip compared with untreated asthmatic mice. Since MDSCs originate in the bone marrow, these results suggest that miR-20b nasal drops may promote the increase of Gr1+CD11b+ MDSCs in the lungs of asthmatic mice by the mechanism of inducing expansion.

[Inhibitory effect of miR-20b on airway inflammation in asthmatic mice].

OBJECTIVE: To explore the effect of miR-20b in inhibiting airway inflammation in a mouse model of asthma. METHODS: Female BALB/c mouse models of asthma, established by sensitizing and challenging the mice with a mixture of ovalbumin and aluminum hydroxide, were subjected to intranasal instillation of 20 µg miR-20b mimics or a miR-20b scramble every 3 days. On day 49, bronchoalveolar lavage fluid (BALF) was collected from the mice to examine the counts of total cells and different cell populations; HE staining was used to observe the pathological changes of the lung tissue, and the concentration of vascular endothelial growth factor (VEGF) in BALF was detected by ELISA. RESULTS: Treatment of the asthmatic mice with miR-20b mimics decreased not only the counts of the total leukocytes, neutrophils and eosinophils in the BALF but also mucus secretion in the airway and inflammatory cell infiltration around the bronchus, and lessened thickening of the airway mucosa. Instillation with miR-20b mimics significantly reduced the concentration of VEGF in BALF from 28.55±3.42 pg/mL in the asthma model group to 18.19±3.67 pg/mL (P<0.01). CONCLUSION: MiR-20b can inhibit airway inflammation in asthmatic mice possibly by reducing the expression of VEGF.

Predictors of retention in community-based methadone maintenance treatment program in Pearl River Delta, China.

BACKGROUND: The aims were to identify predictors of treatment retention in methadone maintenance treatment (MMT) clinics in Pearl River Delta, China. METHODS: Retrospective longitudinal study. PARTICIPANTS: 6 MMT clinics in rural and urban area were selected. STATISTICAL ANALYSIS: Stratified random sampling was employed, and the data were analyzed using Kaplan-Meier survival curves and life table method. Protective or risk factors were explored using Cox's proportional hazards model. Independent variables were enrolled in univariate analysis and among which significant variables were analyzed by multivariate analysis. RESULTS: A total of 2728 patients were enrolled. The median of the retention duration was 13.63 months, and the cumulative retention rates at 1,2,3 years were 53.0%, 35.0%, 20.0%, respectively. Multivariate Cox analysis showed: age, relationship with family, live on support from family or friends, income, considering treatment cost suitable, considering treatment open time suitable, addiction severity (daily expense for drug), communication with former drug taking peer, living in rural area, daily treatment dosage, sharing needles, re-admission and history of being arrested were predictors for MMT retention. CONCLUSIONS: MMT retention rate in Guangdong was low and treatment skills and quality should be improved. Meanwhile, participation of family and society should be encouraged.

[Influence of different extracts from persimmon leaves on the antioxidant activity in diabetic mice].

OBJECTIVE: To investigate the antioxidant effect of different solvent extracts from persimmon leaves (PL) in diabetic mice induced by streptozotocin (STZ). METHODS: The total ethanol-extracted fraction of PL was further extracted with chloroform, ethyl acetate and n-butanol, in that order, the residues after ethanol extraction were water-extracted and alcohol-precipitated, and concentrated. The hypoglycemic effects of different solvents extracts from PL were evaluated in diabetic mice induced by STZ. The experimental mice were randomly divided into groups: control group, model group, glibenclamide group, low and high dosage groups of the various solvent extracts. The drugs were administrated to mice in every morning for 15 days. During this time period, the contents of malondialdehyde (MDA) and superoxide dismutase (SOD) were determined. RESULTS: The water-extracted and ethanol-precipitated fractions and the ethyl acetate-extracted fraction markedly reduced the content of MDA and increased the activity of SOD in the livers of STZ-induced diabetic mice (P<0.01 or P<0.05). The chloroform-extracted and n-butanol-extracted fraction did not markedly reduce the content of MDA nor increase the activity of SOD in liver of STZ-induced diabetic mice (P>0.05). CONCLUSION: The ethyl acetate-extracted fraction, water-extracted and ethanol-precipitated fraction of persimmon leaves have potential value in the treatment of diabetes. The mechanism of action of the antioxidant is related to the hypoglycemic effects of extracts from persimmon leaves.

[Application of peripherally inserted central catheter for parenteral nutrition in critically ill neonates].

OBJECTIVE: To apply peripherally inserted central catheter (PICC) in critically ill neonates who require long-term parenteral nutrition. METHODS: A retrospective review of 98 critically ill neonates who had a PICC inserted and received long-term parenteral nutrition from March to December 2011 was performed. RESULTS: The PICC insertion succeeded in 74.5% (73/98) of the cases at the first attempt. The catheter remained for an average of (19.7 +/- 2.0) days. Of the 98 cases, 92 underwent planned extubation after enteral nutrition was fully established; 10 developed complications within the follow-up period of 956 days. The PICC-associated complications occurred at a rate of 10. 5 per 1000 catheter-days, including infection (n=0), phlebitis (n=1), accidental dislodgement (n=3), catheter occlusion (n=3), and hemorrhage in puncture point (n=3). CONCLUSION: PICC can be used as a safe venous access for critically ill neonates for long-term parenteral nutrition. PICC-associated complications can be reduced through improving nursing skills, especially for catheter-related infection.

Nanosized diblock copolymer micelles as a scaffold for constructing a ratiometric fluorescent sensor for metal ion detection in aqueous media.

A facile strategy was employed to create a fluorescence resonance energy transfer (FRET) based ratiometric sensing system for ferric ions in all-aqueous media by using nanosized poly(ethylene oxide)-b-polystyrene micelles as the scaffold. A hydrophobic fluorescent dye nitrobenzoxadiazolyl derivative (NBD), which served as the energy transfer donor, was incorporated into the micelle core during the micelle formation; a spirolactam rhodamine derivative (SRhB-OH) was chosen as a sensitive and selective sensor for Fe(III) ions and was then 'adsorbed' into the micelle core/corona interface. A highly efficient ring-opening reaction of SRhB-OH induced by Fe(III) generates the long-wavelength rhodamine B fluorophore which can act as the energy acceptor; thus, the micelle nanoparticles can serve as a FRET-based ratiometric detection system for ferric ions. The effects of PS block length on the ion sensing performance of the micelles were investigated, and it has been found that the micelles formed by the copolymer with moderate block length (PEO(113)-b-PS(115)) were preferable as the scaffold for the FRET system and exhibited a sensitive and selective sensing capacity for Fe(III) with a detection limit of 1 microM. This nanoparticle-based sensing strategy may be utilized to construct other ratiometric chemosensors by replacing the current dyes with other suitable ones.