Risk factor evaluation of cuff pressure of >30 cmH2O to stop air leakage during mechanical ventilation: A prospective observational study.

AIM: The commonly recommended endotracheal tube cuff pressure is 20-30 cmH2O. However, some patients require a cuff pressure of >30 cmH2O to prevent air leakage. The study aims to determine the risk factors that contribute to the endotracheal tube cuff pressure of >30 cmH2O to prevent air leakage. DESIGN: A multi-centre prospective observational study. METHODS: Eligible patients undergoing mechanical ventilation in the intensive care unit of three hospitals between March 2020 and July 2022 were included. The endotracheal tube cuff pressure to prevent air leakage was determined using the minimal occlusive volume technique. The patient demographics and clinical information were collected. RESULTS: A total of 284 patients were included. Among these patients, 55 (19.37%) patients required a cuff pressure of >30 cmH2O to prevent air leakage. The multivariate logistic regression results revealed that the surgical operation (odds ratio [OR]: 8.485, 95% confidence interval [CI]: 1.066-67.525, p = 0.043) was inversely associated with the endotracheal tube cuff pressure of >30 cmH2O, while the oral intubation route (OR: 0.127, 95% CI: 0.022-0.750, p = 0.023) and cuff inner diameter minus tracheal area (OR: 0.949, 95% CI: 0.933-0.966, p < 0.001) were negatively associated with the endotracheal tube cuff pressure of >30 cmH2O. Therefore, a significant number of patients require an endotracheal tube cuff pressure of ＞30 cmH2O to prevent air leakage. Several factors, including the surgical operation, intubation route, and difference between the cuff inner diameter and tracheal area at the T3 vertebra, should be considered when determining the appropriate cuff pressure during mechanical ventilation.

Effect of varying cuff sizes with identical inner diameter on endotracheal intubation in critically ill adults: A sealed tracheal controlled trial.

BACKGROUND: The present study aims to determine the impact of different cuff diameters on the cuff pressure of endotracheal tubes (ETTs) when the trachea is adequately sealed. METHODS: In the present single-center clinical trial, adult patients who underwent cardiothoracic surgery were assigned to use ETTs from 2 brands (GME and GZW). The primary endpoint comprised of the following: cuff diameter, inner diameter of the ETT, manufacturer, and the number of subjects with tracheal leakage when the cuff pressure was 30 cm H2O. RESULTS: A total of 298 patients were assigned into 2 groups, based on the 2 distinct brands of ETTs: experimental group (n = 122, GME brand) and control group (n = 176, GZW brand). There were no significant differences in baseline characteristics. However, the cuff diameter was significantly smaller in the control group, when compared to the experimental group (P = .001), and the incidence of tracheal leakage was significantly higher in the control group (P = .001). Furthermore, the GME brand ETT had a significantly larger cuff diameter, when compared to the GZW brand ETT. CONCLUSION: The cuff size would mismatch the tracheal area in clinical practice. Therefore, chest computed tomography is recommended to routinely evaluate the tracheal cross-sectional area during anesthesia, in order to ensure the appropriate cuff size selection.

Appearance of Recalcitrant Dissolved Black Carbon and Dissolved Organic Sulfur in River Waters Following Wildfire Events.

Increasing wildfire frequency, a consequence of global climate change, releases incomplete combustion byproducts such as aquatic pyrogenic dissolved organic matter (DOM) and black carbon (DBC) into waters, posing a threat to water security. In August 2022, a series of severe wildfires occurred in Chongqing, China. Samples from seven locations along the Yangtze and Jialing Rivers revealed DBC, quantified by the benzene poly(carboxylic acid) (BPCA) method, comprising 9.5-19.2% of dissolved organic carbon (DOC). High concentrations of BPCA-DBC with significant polycondensation were detected near wildfire areas, likely due to atmospheric deposition driven by wind. Furthermore, Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) revealed that wildfires were associated with an increase in condensed aromatics, proteins, and unsaturated hydrocarbons, along with a decrease in lignins. The condensed aromatics primarily consisted of dissolved black nitrogen (DBN), contributing to abundant high-nitrogen-containing compounds in locations highly affected by wildfires. Meanwhile, wildfires potentially induced the input of recalcitrant sulfur-containing protein-like compounds, characterized by high oxidation, aliphatic nature, saturation, and low aromaticity. Overall, this study revealed the appearance of recalcitrant DBC and dissolved organic sulfur in river waters following wildfire events, offering novel insights into the potential impacts of wildfires on water quality and environmental biogeochemistry.

Photo-oxidation of Micro- and Nanoplastics: Physical, Chemical, and Biological Effects in Environments.

Micro- and nanoplastics (MNPs) are attracting increasing attention due to their persistence and potential ecological risks. This review critically summarizes the effects of photo-oxidation on the physical, chemical, and biological behaviors of MNPs in aquatic and terrestrial environments. The core of this paper explores how photo-oxidation-induced surface property changes in MNPs affect their adsorption toward contaminants, the stability and mobility of MNPs in water and porous media, as well as the transport of pollutants such as organic pollutants (OPs) and heavy metals (HMs). It then reviews the photochemical processes of MNPs with coexisting constituents, highlighting critical factors affecting the photo-oxidation of MNPs, and the contribution of MNPs to the phototransformation of other contaminants. The distinct biological effects and mechanism of aged MNPs are pointed out, in terms of the toxicity to aquatic organisms, biofilm formation, planktonic microbial growth, and soil and sediment microbial community and function. Furthermore, the research gaps and perspectives are put forward, regarding the underlying interaction mechanisms of MNPs with coexisting natural constituents and pollutants under photo-oxidation conditions, the combined effects of photo-oxidation and natural constituents on the fate of MNPs, and the microbiological effect of photoaged MNPs, especially the biotransformation of pollutants.

Adsorption characteristics and mechanisms of water-soluble polymers (PVP and PEG) on kaolin and montmorillonite minerals.

The excessive use and accumulation of water-soluble polymers (WSPs, known as "liquid plastics") in the environment can pose potential risks to both ecosystems and human health, but the environmental fate of WSPs remains unclear. Here, the adsorption behavior of WSPs with different molecular weight on kaolinite (Kaol) and montmorillonite (Mt) were examined. The results showed that the adsorption of PEG and PVP on minerals were controlled by hydrogen bond and van der Waals force. The Fourier transform infrared (FTIR) spectra and two-dimensional correlation spectroscopy (2D-COS) analysis revealed that there were interactions between the Al-O and Si-O groups of the minerals and the polar O- or N-containing functional groups as well as the alkyl groups of PEG and PVP. The adsorption characteristics of WSPs were closely related to their molecular weight and the pore size of minerals. Due to the relatively large mesopore size of Kaol, both PEG and PVP were absorbed into inner spaces, for which the adsorption capacity increased with molecular weight of the polymers. For Mt, all types of PEG could enter its micropores, while PVP with larger molecular weights appeared to be confined externally, leading to a decrease in the adsorption capacity of PVP with increasing molecular weight. The findings of this study provide a theoretical basis for scientific evaluation of environmental processes of WSPs.

A Suboptimal Optimizing Strategy for Velocity Vector Estimation in Single-Observer Passive Localization.

In a single-observer passive localization system, the velocity and position of the target are estimated simultaneously. However, this can lead to correlated errors and distortion of the estimated value, making independent estimation of the speed and position necessary. In this study, we introduce a novel optimization strategy, suboptimal estimation, for independently estimating the velocity vector in single-observer passive localization. The suboptimal estimation strategy converts the estimation of the velocity vector into a search for the global optimal solution by dynamically weighting multiple optimization criteria from the starting point in the solution space. Simulation verification is conducted using uniform motion and constant acceleration models. The results demonstrate that the proposed method converges faster with higher accuracy and strong robustness.

The volatile flavor and the antioxidant properties of a novel chrysanthemum rice wine during natural aging.

Chrysanthemum morifolium cv. Fubaiju, a traditional tea in southern China with high nutritional and health functions was used in this study. Optimized production conditions of a novel chrysanthemum rice wine (FRW) were obtained by the Box-Behnken design response surface experiment. FRW with best sensory quality was developed with 0.68% chrysanthemum, 0.79% Jiuqu and 0.81:1 liquid-to-solid ratio. Compared with rice wine (RW) control, the total phenolic and flavonoid contents, as well as antioxidant activity of the FRW increased significantly. GC-MS analysis showed that more flavor compounds including alcohols, aldehydes, acids, and esters were detected in FRW. During the aging process, it was found that the antioxidant substances, the antioxidant activity and the flavor substances decreased, with the wine body tending to be homogenized. After 6 months of storage, overall sensory quality of FRW was more harmonious, with special nectar taste, which dramatically improved the flavor characteristics and functionality compared with traditional RW.

Assessing the Mass Concentration of Microplastics and Nanoplastics in Wastewater Treatment Plants by Pyrolysis Gas Chromatography-Mass Spectrometry.

The level of microplastics (MPs) in wastewater treatment plants (WWTPs) has been well evaluated by the particle number, while the mass concentration of MPs and especially nanoplastics (NPs) remains unclear. In this study, pyrolysis gas chromatography-mass spectrometry was used to determine the mass concentrations of MPs and NPs with different size ranges (0.01-1, 1-50, and 50-1000 µm) across the whole treatment schemes in two WWTPs. The mass concentrations of total MPs and NPs decreased from 26.23 and 11.28 µg/L in the influent to 1.75 and 0.71 µg/L in the effluent, with removal rates of 93.3 and 93.7% in plants A and B, respectively. The proportions of NPs (0.01-1 µm) were 12.0-17.9 and 5.6-19.5% in plants A and B, respectively, and the removal efficiency of NPs was lower than that of MPs (>1 µm). Based on annual wastewater effluent discharge, it is estimated that about 0.321 and 0.052 tons of MPs and NPs were released into the river each year. Overall, this study investigated the mass concentration of MPs and NPs with a wide size range of 0.01-1000 µm in wastewater, which provided valuable information regarding the pollution level and distribution characteristics of MPs, especially NPs, in WWTPs.

Establishment of a nomogram for predicting prolonged mechanical ventilation in cardiovascular surgery patients.

AIMS: This study aimed to develop a nomogram model for predicting prolonged mechanical ventilation (PMV) in patients undergoing cardiovascular surgery. METHODS AND RESULTS: In total, 693 patients undergoing cardiovascular surgery at an Affiliated Hospital of Nantong University between January 2018 and June 2020 were studied. Postoperative PMV was required in 147 patients (21.2%). Logistic regression analysis showed that delirium [odds ratio (OR), 3.063; 95% confidence interval (CI), 1.991-4.713; P < 0.001], intraoperative blood transfusion (OR, 2.489; 95% CI, 1.565-3.960; P < 0.001), obesity (OR, 2.789; 95% CI, 1.543-5.040; P = 0.001), postoperative serum creatinine level (mmol/L; OR, 1.012; 95% CI, 1.007-1.017; P < 0.001), postoperative serum albumin level (g/L; OR, 0.937; 95% CI, 0.902-0.973; P = 0.001), and postoperative total bilirubin level (µmol/L; OR, 1.020; 95% CI, 1.005-1.034; P = 0.008) were independent risk factors for PMV. The area under the receiver operating characteristic curve for our nomogram was found to be 0.770 (95% CI, 0.727-0.813). The goodness-of-fit test indicated that the model fitted the data well (χ2 = 12.480, P = 0.131). After the model was internally validated, the calibration plot demonstrated good performance of the nomogram, as supported by the Harrell concordance index of 0.760. Decision curve analysis demonstrated that the nomogram was clinically useful in identifying patients at risk for PMV. CONCLUSION: We established a new nomogram model that may provide an individual prediction of PMV. This model may provide nurses, social workers, physicians, and administrators with an accurate and objective assessment tool to identify patients at high risk for PMV after cardiovascular surgery.

Combined effects of photoaging and natural organic matter on the colloidal stability of nanoplastics in aquatic environments.

The transport and fate of nanoplastics (NPs) in aquatic environments are closely associated with their colloidal stability, which is affected by aging and natural organic matter (NOM) adsorption. This study systematically investigated the combined effects of photoaging and NOM (e.g. humic acids, HA; and a model protein, bovine serum albumin, BSA) on the aggregation kinetics of NPs (polystyrene, PS) in NaCl and CaCl2 solutions. Our results showed that photoaged NPs adsorbed less HA than pristine NPs due to weaker hydrophobic and π-π interactions. In return, HA showed weaker impacts on NPs' stability after photoaging. Differently, photoaged NPs absorbed more BSA than pristine NPs due to stronger hydrogen bonding and electrostatic attraction. Thus, the inhibitory effects of BSA on the aggregation kinetics of NPs were enhanced after photoaging. Regarding the effects of NOM on the aging of NPs, our results showed that HA competed with NPs for photons and underwent photo-degradation. Subsequently, the destruction/reconstruction of adsorbed HA increased (in NaCl) or decreased (in CaCl2) the stability of NPs. Notably, light radiation-induced flocculation of BSA molecules, which wrapped and integrated NPs and lead to their destabilization. Overall, this study provided new insights into the aggregation behavior of NPs in aquatic systems, which have significant implications for predicting the transport and fate of NPs in complex real-world environments.

Prediction model for delirium in patients with cardiovascular surgery: development and validation.

BACKGROUND: The aim of this study was to construct a nomogram model for discriminating the risk of delirium in patients undergoing cardiovascular surgery. METHODS: From January 2017 to June 2020, we collected data from 838 patients who underwent cardiovascular surgery at the Affiliated Hospital of Nantong University. Patients were randomly divided into a training set and a validation set at a 5:5 ratio. A nomogram model was established based on logistic regression. Discrimination and calibration were used to evaluate the predictive performance of the model. RESULTS: The incidence of delirium was 48.3%. A total of 389 patients were in the modelling group, and 449 patients were in the verification group. Logistic regression analysis showed that CPB duration (OR [Formula: see text] 1.004, 95% CI: 1.001-1.008, [Formula: see text] 0.018), postoperative serum sodium (OR [Formula: see text] 1.112, 95% CI: 1.049-1.178, [Formula: see text] 0.001), age (OR [Formula: see text] 1.027, 95% CI: 1.006-1.048, [Formula: see text] 0.011), and postoperative MV (OR [Formula: see text] 1.019, 95% CI: 1.008-1.030, [Formula: see text] 0.001) were independent risk factors. The results showed that AUC[Formula: see text] was 0.712 and that the 95% CI was 0.661-0.762. The Hosmer-Lemeshow goodness of fit test showed that the predicted results of the model were in good agreement with the actual situation ([Formula: see text] 6.200, [Formula: see text] 0.625). The results of verification showed that the AUC[Formula: see text] was 0.705, and the 95% CI was 0.657-0.752. The Hosmer-Lemeshow goodness of fit test results were [Formula: see text] 8.653 and [Formula: see text] 0.372, indicating that the predictive effect of the model is good. CONCLUSIONS: The establishment of the model provides accurate and objective assessment tools for medical staff to start preventing postoperative delirium in a purposeful and focused manner when a patient enters the CSICU after surgery.

Identification and Quantification of Nanoplastics in Surface Water and Groundwater by Pyrolysis Gas Chromatography-Mass Spectrometry.

Nanoplastics (NPs) are currently considered an environmental pollutant of concern, but the actual extent of NP pollution in environmental water bodies remains unclear and there is not enough quantitative data to conduct proper risk assessments. In this study, a pretreatment method combining ultrafiltration (UF, 100 kDa) with hydrogen peroxide digestion and subsequent detection with pyrolysis gas chromatography-mass spectrometry (Py-GC/MS) was developed and used to identify and quantify six selected NPs in surface water (SW) and groundwater (GW), including poly(vinylchloride) (PVC), poly(methyl methacrylate) (PMMA), polypropylene (PP), polystyrene (PS), polyethylene (PE), and poly(ethylene terephthalate) (PET). The results show that the proposed method could detect NPs in environmental water samples. Nearly all selected NPs could be detected in the surface water at all locations, while PVC, PMMA, PS, and PET NPs were frequently below the detection limit in the groundwater. PP (32.9-69.9%) and PE (21.3-44.3%) NPs were the dominant components in both surface water and groundwater, although there were significant differences in the pollution levels attributed to the filtration efficiency of riverbank, with total mass concentrations of 0.283-0.793 µg/L (SW) and 0.021-0.203 µg/L (GW). Overall, this study quantified the NPs in complex aquatic environments for the first time, filling in gaps in our knowledge about NP pollution levels and providing a useful methodology and important reference data for future research.

Influence of dissolved black carbon on the aggregation and deposition of polystyrene nanoplastics: Comparison with dissolved humic acid.

Dissolved black carbon (DBC), widely found in soil and water environments is likely to affect the transport of nanoplastics in aquatic environments. The aggregation and deposition behaviors of fresh and aged polystyrene nanoplastics (PSs) with and without DBC in NaCl solution were investigated by time-resolved dynamic light scattering (DLS) and quartz crystal microbalance with dissipation monitoring equipment (QCM-D) techniques. The results suggest that DBC can screen the surface charges of PSs by interacting with PSs through hydrogen bonding, hydrophobic interactions and π-π interactions, although they were negatively charged. DBC promoted the aggregation of PSs under relatively low ionic strengths, and it minimally affected the stability of PSs under high ionic strength. Deposition experiments showed that both DBC in salt solution and DBC adsorption on silica surface facilitated the deposition of fresh PSs while HA inhibited both deposition processes. After aging, PSs were more stable, and the effects of DBC and HA were weakened. This study investigated the influence mechanism of DBC on the aggregation and deposition behaviors, which provides new insights into the stability and transport of PSs in complex aquatic environments.

Interactions between activated sludge extracellular polymeric substances and model carrier surfaces in WWTPs: A combination of QCM-D, AFM and XDLVO prediction.

To understand the biofilm formation of biofilm-based processes in wastewater treatment plants (WWTPs), the interaction mechanisms between extracted extracellular polymeric substances (EPS) and three model carrier surfaces (i.e., negatively charged hydrophilic silica, positively charged hydrophilic alumina, and neutral charged hydrophobic polystyrene) were investigated employing a laboratory quartz crystal microbalance with dissipation monitoring equipment (QCM-D) and an atomic force microscope (AFM). The data suggested that surface charge and hydrophobicity of both EPS and carriers played significant roles in the interaction behaviors. Moreover, increases in ionic strength could lead to the increasing zeta potential and hydrophobicity of EPS. It is worth noting that long-range DLVO forces dominated the EPS deposition on carriers in lower ionic strength while short-range Lewis acid-base (AB) interaction controlled the adhesion behaviors in higher ionic strength. Besides, the presence of calcium ions contributed to the adhesion behaviors because of strong charge neutralization and hydrophobic effect. Bound EPS (BEPS) showed higher affinity to model carriers than dissolved EPS (DEPS), which conformed to XDLVO prediction rather than classical DLVO model. Overall, these results provide insights into the influence mechanisms of carrier characteristics, ionic strength, calcium ion and EPS components on the interaction between EPS and representative carriers, contributing to predict and regulate biofilm formation in biofilm-based processes.

Impacts of carrier properties, environmental conditions and extracellular polymeric substances on biofilm formation of sieved fine particles from activated sludge.

To investigate the effect of properties of carriers, environmental conditions and extracellular polymeric substances (EPS) on the initial adhesion of biofilm formation in biofilm-based reactors, a quartz crystal microbalance with dissipation (QCM-D) was applied to monitor the deposition rates and viscoelastic properties of sieved sludge particles on model biocarriers. The results suggested that surface charge, hydrophobicity and surface coating of five representative carriers influenced deposition rates and viscoelastic properties of biofilm, whose variation with NaCl concentrations was controlled by not only the Derjaguin-Landau-Verwey-Overbeek (DLVO) interaction but also non-DLVO forces. On hydrophobic surface, the addition of cationic substances enhanced the deposition rates and the compaction of deposited layer due to strong "hydrophobizing effect". For examples, 10 mM Ca2+, 10 mM Mg2+ and 10 mg/L poly-l-lysine enhanced the deposition rates to nearly 3, 2 and 4 times, as well as reduced the softness of deposited layer to almost 35%, 60% and 35%. Conversely, 10 mg/L negatively charged alginate might cause water retainment and steric shielding, thereby reducing the deposition rates to 40% and increasing the softness of deposited film to 120%. The presence of EPS sub-fractions can modify surface properties of sludge particles, to distinct degrees, contributing to biofilm formation. Notably, compared to tightly bound EPS (TB-EPS), loosely bound EPS (LB-EPS) was more conducive to microbial attachment, but the presence of LB-EPS promoted the formation of a soft layer on a hydrophobic surface. Overall, these results provide insights into intrinsic mechanisms of the variation of deposition rates and viscoelastic properties responding to critical factors, which are meaningful to predict and regulate the initial adhesion process in biofilm-based reactors.

Thallium(I) Oxidation by Permanganate and Chlorine: Kinetics and Manganese Dioxide Catalysis.

The oxidation of the toxic heavy metal thallium(I) (Tl(I)) is an efficient way to enhance Tl removal from water and wastewater. However, few studies have focused on the kinetics of Tl(I) oxidation in water, especially at environmentally relevant pH values. Therefore, the kinetics and mechanisms of Tl(I) oxidation by the common agents KMnO4 and HOCl under environmentally relevant pH condition were explored in the present study. The results indicated that the pH-dependent oxidation of Tl(I) by KMnO4 exhibited second-order kinetics under alkaline conditions (pH 8-10) with the main active species being TlOH, while the reaction could be characterized by autocatalysis at pH 4-6, and Mn(III) might also play an essential role in the MnO2 catalysis. Furthermore, a two-electron transfer mechanism under alkaline conditions was preliminarily proposed by using linear free energy relationships and X-ray photoelectron spectroscopy (XPS) analysis. Distinctively, the reaction rate of Tl(I) oxidation by HOCl decreased with increasing pH, and protonated chlorine might be the main active species. Moreover, the Tl(I)-HOCl reaction could be regarded as first order with respect to Tl(I), but the order with respect to HOCl was variable. Significant catalysis by MnO2 could also be observed in the oxidation of Tl(I) by HOCl, mainly due to the vacancies on MnO2 as active sites for sorbing Tl. This study elucidates the oxidation characteristics of thallium and establishes a theoretical foundation for the oxidation processes in thallium removal.

Interpreting the role of NO3-, SO42-, and extracellular polymeric substances on aggregation kinetics of CeO2 nanoparticles: Measurement and modeling.

The early stage of aggregation of cerium oxide nanoparticles (CeO2 NPs) in anion solutions was inspected in the absence and presence of extracellular polymeric substance (EPS) with a help of time-resolved dynamic light scattering (DLS). The aggregation kinetics and attachment efficiencies were calculated according to measured hydrodynamic diameter across a range of 1-500 mM NaNO3 and 0.01-100. mM Na2SO4. The aggregation of CeO2 NPs in both NaNO3 and Na2SO4 solution conformed with the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory. In NaNO3 solution, the critical coagulation concentrations (CCC) of CeO2 NPs was calculated to be about 47 mM; in Na2SO4 solution, CeO2 NPs showed a re-stabilization process and thus there was no CCC value. SO42- had intenser effects on CeO2 NPs aggregation than NO3- might because of the distinction between their polarization, consisting in Hofmeister series. The presence of bound EPS (B-EPS), tightly bound EPS (TB-EPS) and loosely bound EPS (LB-EPS) in NaNO3 solutions all lead to significant decrease in CeO2 NPs aggregation. Steric repulsive force produced by absorbed EPS on CeO2 NPs might take main responsibility in stabilizing CeO2 NPs. Besides, Extended Derjaguin-Landau-Verwey-Overbeek (EDLVO) model successfully predicted the energy barrier between CeO2 NPs with B-EPS, TB-EPS and LB-EPS as a function of NaNO3 concentration. Furthermore, the difference in impeding the CeO2 NPs aggregation with B-EPS, TB-EPS and LB-EPS may be caused by the divergence in molecular weight and component mass fraction especially protein content. These results might subserve the assessment on the fate and transport behaviors of CeO2 NPs released in wastewater treatment plants.

A review on the interactions between engineered nanoparticles with extracellular and intracellular polymeric substances from wastewater treatment aggregates.

Engineered nanoparticles (ENPs) will inevitably enter wastewater treatment plants (WWTPs) due to their widespread application; thus, it is necessary to study the migration and transformation of nanoparticles in sewage treatment systems. Extracellular polymeric substances (EPSs) such as polysaccharides, proteins, nucleic acids, humic acids and other polymers are polymers released by microorganisms under certain conditions. Intracellular polymeric substances (IPSs) are microbial substances contained in the body with compositions similar to those of extracellular polymers. In this review, we summarize the characteristics of EPSs and IPSs from sewage-collecting microbial aggregates containing pure bacteria, activated sludge, granular sludge and biofilms. We also further investigate the dissolution, adsorption, aggregation, deposition, oxidation and other chemical transformation processes of nanoparticles, such as metals, metal oxides, and nonmetallic oxides. In particular, the review deeply analyzes the migration and transformation mechanisms of nanoparticles in EPS and IPS matrices, including physical, chemical, biological interactions mechanisms. Moreover, various factors, such as ionic strength, ionic valence, pH, light, oxidation-reduction potential and dissolved oxygen, influencing the interaction mechanisms are discussed. In recent years, studies on the interactions between EPSs/IPSs and nanoparticles have gradually increased, but the mechanisms of these interactions are seldom explored. Therefore, developing a systematic understanding of the migration and transformation mechanisms of ENPs is significant.

5% NaHCO3 Is Appropriate for Skin Cleaning With Central Venous Catheters.

OBJECTIVES: The purpose of this study was to compare the effects of skin cleaning with 5% NaHCO3 to 75% alcohol on the removal of skin grease and pain of patients with central venous catheters (CVC). MATERIALS AND METHODS: This was a randomized, controlled, single-blinded and prospective study. From January-September 2015, 143 consecutive patients who met the inclusion and exclusion criteria and who underwent elective cardiovascular surgery with placement of a CVC were selected. Patients were randomly divided into 2 groups according to the disinfection preparation procedure: experimental group (n = 60), in which 5% NaHCO3 and distilled water solution at 40-45°C were used, and the control group (n = 66), in which 75% alcohol was used. Main outcome measures were verbal rating scale pain score, satisfaction and bacterial count after 2 minutes of iodine disinfection. RESULTS: The verbal rating scale pain scores were lower in the experimental group than in the control group (P < 0.001). In the control group, 4.5% of patients and 43% of nurses were satisfied with 75% alcohol cleaning before disinfection procedure, compared to 74% and 78%, respectively, in the experimental group. The bacterial count did not show any difference between these 2 groups after iodine disinfection (P = 0.455). CONCLUSIONS: Cleaning of the CVC before disinfection with 5% NaHCO3 and distilled water at 40-45°C alleviated pain and improved patient and nurse satisfaction compared with using 75% alcohol.