Hemodynamic Characteristics of Cardiovascular System in Simulated Zero and Partial Gravities Based on CFD Modeling and Simulation.

Zero and partial gravities (ZPG) increase cardiovascular risk, while the corresponding theoretical foundation remains uncertain. In the article, the ZPG were generated through a rotating frame with two degrees of freedom in combination with the random walk algorithm. A precise 3D geometric configuration of the cardiovascular system was developed, and the Navier-Stokes laminar flow and solid mechanics were used as governing equations for blood flow and the surrounding tissue in the cardiovascular system. The ZPG were designed into governing equations through the volume force term. The computational fluid dynamics' (CFD) simulations in combination with proper boundary conditions were carried out to investigate the influences of ZPG on the distribution of blood flow velocity, pressure, and shear stress in the cardiovascular system. The findings show that as simulated gravity gradually decreases from 0.7 g to 0.5 g to 0.3 g to 0 g, as opposed to normal gravity of 1 g, the maximum values of blood flow velocity, pressure, and shear stress on the walls of the aorta and its ramification significantly increase, which would lead to cardiovascular diseases. The research will lay a theoretical foundation for the comprehension of the ZPG effect on cardiovascular risk and the development of effective prevention and control measures under the circumstance of ZPG.

Pulmonary Infections and Outcomes in AIDS Patients with Respiratory Failure: A 10-Year Retrospective Review.

Background: Respiratory failure in acquired immunodeficiency syndrome (AIDS) patients was the leading cause of intensive care unit (ICU) admission in our center. We aimed to describe the pulmonary infections and outcomes for respiratory failure in AIDS patients. Methods: A retrospective study was conducted on AIDS adult patients with respiratory failure who were admitted to the ICU in Beijing Ditan hospital, China, from January 2012 to December 2021. We investigated pulmonary infections complicated by respiratory failure in AIDS patients. The primary outcome was ICU mortality, and a comparison between survivors and nonsurvivors was performed. Multiple logistic regression analysis was used to identify predictors of ICU mortality. The Kaplan-Meier curve and Log rank test were used for survival analysis. Results: A total of 231 AIDS patients were admitted to ICU with respiratory failure over a 10-year period with a male predominance (95.7%). Pneumocystis jirovecii pneumonia was the main etiology of pulmonary infections (80.1%). The ICU mortality was 32.9%. In multivariate analysis, ICU mortality was independently associated with invasive mechanical ventilation (IMV) [odds ratio (OR), 27.910; 95% confidence interval (CI, 8.392-92.818; p = 0.000) and the time before ICU admission (OR, 0.959; 95% CI, 0.920-0.999; p = 0.046). In the survival analysis, patients with IMV and later admission to ICU had a higher probability of mortality. Conclusion: Pneumocystis jirovecii pneumonia was the primary etiology for respiratory failure in AIDS patients admitted to the ICU. Respiratory failure remains a severe illness with high mortality, and ICU mortality was negatively associated with IMV and later admission to ICU.

High-Flow Nasal Cannula Oxygen Therapy versus Non-Invasive Ventilation in AIDS Patients with Acute Respiratory Failure: A Randomized Controlled Trial.

BACKGROUND: Acute respiratory failure (ARF) remains the most common diagnosis for intensive care unit (ICU) admission in acquired immunodeficiency syndrome (AIDS) patients. METHODS: We conducted a single-center, prospective, open-labeled, randomized controlled trial at the ICU, Beijing Ditan Hospital, China. AIDS patients with ARF were enrolled and randomly assigned in a 1:1 ratio to receive either high-flow nasal cannula (HFNC) oxygen therapy or non-invasive ventilation (NIV) immediately after randomization. The primary outcome was the need for endotracheal intubation on day 28. RESULTS: 120 AIDS patients were enrolled and 56 patients in the HFNC group and 57 patients in the NIV group after secondary exclusion. Pneumocystis pneumonia (PCP) was the main etiology for ARF (94.7%). The intubation rates on day 28 were similar to HFNC and NIV (28.6% vs. 35.1%, p = 0.457). Kaplan-Meier curves showed no statistical difference in cumulative intubation rates between the two groups (log-rank test 0.401, p = 0.527). The number of airway care interventions in the HFNC group was fewer than in the NIV group (6 (5-7) vs. 8 (6-9), p < 0.001). The rate of intolerance in the HFNC group was lower than in the NIV group (1.8% vs. 14.0%, p = 0.032). The VAS scores of device discomfort in the HFNC group were lower than that in the NIV group at 2 h (4 (4-5) vs. 5 (4-7), p = 0.042) and at 24 h (4 (3-4) vs. 4 (3-6), p = 0.036). The respiratory rate in the HFNC group was lower than that in the NIV group at 24 h (25 ± 4/min vs. 27 ± 5/min, p = 0.041). CONCLUSIONS: Among AIDS patients with ARF, there was no statistical significance of the intubation rate between HFNC and NIV. HFNC had better tolerance and device comfort, fewer airway care interventions, and a lower respiratory rate than NIV. CLINICAL TRIAL NUMBER: Chictr.org (ChiCTR1900022241).

Fabrication of Phytic Acid/Urea Co-Modified Bamboo Biochar and Its Application as Green Flame Retardant for Polylactic Acid Resins.

It is of great significance to develop green, sustainable additives to improve the thermal stability and flame retardancy of biopolymers. In this work, a synergistic modification of P/N elements to bamboo biochar (mBC) was successfully achieved by grafting a reaction of phytic acid and urea with preoxidized bamboo biochar. Fourier transform infrared spectroscopy, X-ray diffraction, nuclear magnetic resonance and scanning electron microscope determinations of the mBC demonstrated a successive grafting of phytic acid and urea to the originally porous surface. The ground mBC was blended with polylactic acid (PLA) to prepare mBC/PLA composites by extrusion and hot pressing. Mechanical strength studies showed a compromise in rigidity, which might originate from the mBC overdose and its limited miscibility with the resin. The thermogravimetric results supported the fact that the enhancement of thermal stability and flame retardancy of the composites with the mBC dosage, which showed that the mBC dosage in the PLA composites was not only lower than that of the conventional flame retardants, but also outperformed the counterparts using BC modified by inorganic phosphoric acid and urea. The mBC was prone to accelerate the earlier decomposition of the composites (30 °C lower in decomposition) and generate a continuous, dense residual carbon layer, which provides an effective shield resisting the mass and heat transfer between the combustion area and the underlying composite matrix. Only 10 wt% of mBC dosage could achieve a V-0 rating (UL94) for the composite, with a higher limiting oxygen index up to 28.3% compared to 20.7% for that of the virgin PLA; the cone colorimetric results also suggested that the flame retardancy had been greatly improved for all composites. In this work, biobased P-/N-containing bamboo biochar would be expected as a nontoxic biochar-based flame retardant that serves as green filler in polymer composites.

Synthesis of P-/N-Containing Bamboo-Activated Carbon toward Enhanced Thermal Stability and Flame Retardancy of Polylactic Acid.

A P-/N-containing bamboo-activated carbon (BACm) was successfully synthesized by steam activation of bamboo charcoal and chemical grafting to as-prepared activated carbon using the reaction of phosphoric acid and urea. Characterizations of BACm presented a synergistic grafting of P and N elements to the BAC surface. The BACm was further loaded in a polylactic acid (PLA) matrix to prepare BACm/PLA composites. Mechanical strength study showed tensile strength dropped from 75.19 MPa to 61.30 MPa, and tensile modulus from 602.49 MPa to 375.56 MPa, suggesting a rigidity reduction and deformation resistance enhancement owing to the roughened surface of BACm that interlocked with the polymer. The thermogravimetric analysis showed that the carbon residue rate of BACm dramatically fell to 49.25 wt.% in contrast to 88.28% for the control BAC, and cone calorimeter measurements confirmed the enhancement of flame retardancy of the composites with BACm loading, and the carbon residue rate increased progressively with BACm loading in the composites, notably up to 8.60 wt.% for the BAC/PLA9 composite, which outweighed the theoretical residue rate by more than 50%. The elemental analysis also confirmed rich P/N levels of the dense carbon residue layer that could perform synergistically and effectively in fire suppression. The BACm tended to stimulate the earlier decomposition of the composites and formed a continuous residual carbon layer which functioned as an effective barrier hindering the mass and heat transfer between the combustion zone and the underlying matrix. Moreover, 9 wt.% of BACm loading could attain a V-0 rating (UL94) for the composite with an improved limiting oxygen index up to 31.7%. The biomass-based modified activated carbon in this work could be considered as an alternative flame retardant in polymer applications.

Extracorporeal membrane oxygenation in curing a young man after modified Fontan operation: A case report.

BACKGROUND: The Fontan operation is the only treatment option to change the anatomy of the heart and help improve patients' hemodynamics. After successful operation, patients typically recover the ability to engage in general physical activity. As a better ventilatory strategy, extracorporeal membrane oxygenation (ECMO) provides gas exchange via an extracorporeal circuit, and is increasingly being used to improve respiratory and circulatory function. After the modified Fontan operation, circulation is different from that of patients who are not subjected to the procedure. This paper describe a successful case using ECMO in curing influenza A infection in a young man, who was diagnosed with Tausing-Bing syndrome and underwent Fontan operation 13 years ago. The special cardiac structure and circulatory characteristics are explored in this case. CASE SUMMARY: We report a successful case using ECMO in curing influenza A infection in a 23-year-old man, who was diagnosed with Tausing-Bing syndrome and underwent Fontan operation 13 years ago. The man was admitted to the intensive care unit with severe acute respiratory distress syndrome as a result of influenza A infection. He was initially treated by veno-venous (VV) ECMO, which was switched to veno-venous-arterial ECMO (VVA ECMO) 5 d later. As circulation and respiratory function gradually improved, the VVA ECMO equipment was removed on May 1, 2018. The patient was successfully withdrawn from artificial ventilation on May 28, 2018 and then discharged from hospital on May 30, 2018. CONCLUSION: After the modified Fontan operation, circulation is different compared with that of patients who are not subjected to the procedure. There are certainly many differences between them when they receive the treatment of ECMO. Due to the special cardiac structure and circulatory characteristics, an individualized liquid management strategy is necessary and it might be better for them to choose an active circulation support earlier.

Intumescent-Grafted Bamboo Charcoal: A Natural Nontoxic Fire-Retardant Filler for Polylactic Acid (PLA) Composites.

In this work, an alternative flame-retardant filler based on phosphate- and urea-grafted bamboo charcoal (BC-m) at 10-30 wt % addition was aimed at improving the flame retardancy of polylactic acid (PLA) composites. The filler caused only a small reduction in strength properties but a slight increase in the modulus of elasticity of PLA composites. BC-m significantly improved the flame-retardant performance compared with pure BC. The limiting oxygen index (LOI) was 28.0 vol % when 10 wt % of BC-m was added, and 32.1 vol % for 30 wt % addition, which was much greater than the value of 22.5 vol % for 30 wt % pure BC. Unlike pure BC, adding BC-m at 20 wt % or more gave a UL-94 vertical flame test rating of V-0 with significantly reduced melt dripping. The peak heat release rate (pHRR) and total heat release (THR) of BC-m/PLA composites decreased by more than 50% compared with pure PLA, and the values for 20% BC-m were significantly less than that for 25% BC addition. The grafted biochar-based system provides an effective flame retardancy effect by a condensed-phase protective barrier through the rapid formation of a dense, honeycomb-like cross-linked carbonized char layer. The results suggest a promising route to enhancing the flame-retardant properties of biodegradable polymer composites using nontoxic, more environmentally friendly grafted biochar.

Enhancement of Flame Retardancy and Mechanical Properties of Polylactic Acid with a Biodegradable Fire-Retardant Filler System Based on Bamboo Charcoal.

A cooperative flame-retardant system based on natural intumescent-grafted bamboo charcoal (BC) and chitosan (CS) was developed for polylactic acid (PLA) with improved flame retardancy and minimal decline in strength properties. Chitosan (CS) as an adhesion promoter improved the interfacial compatibility between graft-modified bamboo charcoal (BC-m) and PLA leading to enhanced tensile properties by 11.11% and 8.42%, respectively for tensile strength and modulus. At 3 wt.% CS and 30 wt.% BC-m, the crystallinity of the composite increased to 38.92%, or 43 times that of pure PLA (0.9%). CS promotes the reorganization of the internal crystal structure. Thermogravimetric analysis showed significantly improved material retention of PLA composites in nitrogen and air atmosphere. Residue rate for 5 wt.% CS and 30 wt.% BC-m was 29.42% which is 55.1% higher than the theoretical value of 18.97%. Flammability tests (limiting oxygen index-LOI and UL-94) indicated significantly improved flame retardancy and evidence of cooperation between CS and BC-m, with calculated cooperative effectiveness index(Ce) >1. From CONE tests, the peak heat release rate (pHRR) and total heat release (THR) were reduced by 26.9% and 30.5%, respectively, for 3% CS + 20% BC-m in PLA compared with adding 20% BC-m alone. Analysis of carbon residue morphology, chemical elements and structure suggest CS and BC-m form a more stable char containing pyrophosphate. This char provides heat insulation to inhibit complete polymer pyrolysis, resulting in improved flame retardancy of PLA composites. Optimal mix may be recommended at 20% BC-m + 3% CS to balance compatibility, composite strength properties and flame retardance.

Sludge amendment accelerating reclamation process of reconstructed mining substrates.

We constructed a mining soil restoration system combining plant, complex substrate and microbe. Sludge was added to reconstructed mine substrates (RMS) to accelerate the reclamation process. The effect of sludge on plant growth, microbial activity, soil aggregate stability, and aggregation-associated soil characteristics was monitored during 10 years of reclamation. Results show that the height and total biomass of ryegrass increases with reclamation time. Sludge amendment increases the aggregate binding agent content and soil aggregate stability. Soil organic carbon (SOC) and light-fraction SOC (LFOC) in the RMS increase by 151% and 247% compared with those of the control, respectively. A similar trend was observed for the glomalin-related soil protein (GRSP). Stable soil aggregate indexes increase until the seventh year. In short, the variables of RMS determined after 3-7 years insignificantly differ from those of the untreated sample in the tenth-year. Furthermore, significant positive correlations between the GRSP and SOC and GRSP and soil structure-related variables were observed in RMS. Biological stimulation of the SOC and GRSP accelerates the recovery of the soil structure and ecosystem function. Consequently, the plant-complex substrate-microbe ecological restoration system can be used as an effective tool in early mining soil reclamation.

Effects of fitness qigong and tai chi on middle-aged and elderly patients with type 2 diabetes mellitus.

Currently, qigong and tai chi exercises are the two most common preventive as well as therapeutic interventions for chronic metabolic diseases such as type 2 diabetes mellitus (T2DM). However, the quantitative evaluation of these interventions is limited. This study aimed to evaluate the therapeutic efficacy of qigong and tai chi intervention in middle-aged and older adults with T2DM. The study included 103 eligible participants, who were randomized to participate for 12 weeks, in one of the following intervention groups for the treatment of T2DM: fitness qigong, tai chi, and control group. Three biochemical measures, including fasting plasma glucose (FPG), glycated hemoglobin (HbA1C), and C-peptide (C-P) levels, assessed at baseline and 12 weeks, served as the primary outcome measures. During the training process, 16 of the 103 participants dropped out. After the 12-week intervention, there were significant influences on HbA1C (F2,83 = 4.88, p = 0.010) and C-P levels (F2,83 = 3.64, p = 0.031). Moreover, significant reduction in C-P levels was observed after 12-week tai chi practice (p = 0.004). Furthermore, there was a significant negative correlation between the duration of T2DM and the relative changes in FPG levels after qigong intervention, and the relative changes in HbA1C levels were positively correlated with waist-to-height ratio after tai chi practice. Our study suggests that targeted qigong exercise might have a better interventional effect on patients with a longer duration of T2DM, while tai chi might be risky for people with central obesity. Trial registration: This trial was registered in Chinese Clinical Trial Registry. The registration number is ChiCTR180020069. The public title is "Health-care qigong · study for the prescription of chronic diabetes intervention."

Continuous renal replacement therapy in patients with HIV/AIDS.

BACKGROUND: Acute kidney injury (AKI) is a common complication among human immunodeficiency virus (HIV)-infected patients resulting in increased morbidity and mortality. Continuous renal replacement therapy (CRRT) is a useful method and instrument in critically ill patients with fluid overload and metabolic disarray, especially in those who are unable to tolerate the intermittent hemodialysis. However, the epidemiology, influence factors of CRRT and mortality in patients with HIV/AIDS are still unclear in China. This study aims to study the HIV-infected patients admitted in Intensive Care Unit (ICU) and explore the influence factors correlated with CRRT and their prognosis. METHODS: We performed a retrospective case-control study in the ICU of the Beijing Ditan Hospital Capital Medical University. From June 1, 2005 to May 31, 2017, 225 cases were enrolled in this clinical study. RESULTS: 122 (54.2%) patients were diagnosed with AKI during their stay in ICU, the number and percentage of AKI stage 1, 2 and 3 were 38 (31.1%), 21(17.2%) and 63(51.7%), respectively. 26.2% of AKI patients received CRRT during the stay of ICU. 56.25% CRRT patients died in ICU. The 28-day mortality was 62.5%, and the 90-day mortality was 75%. By univariate logistics analysis, it showed that higher likelihood of diagnosis for respiratory failure (OR = 7.333,95% CI 1.467-36.664, p = 0.015), higher likelihood of diagnosis for septic shock (OR = 1.005,95% CI 1.001-1.01, p = 0.018), and higher likelihood to use vasoactive agents (OR = 10.667,95% CI 1.743-65.271, p = 0.001), longer mechanical ventilation duration (OR = 1.011,95% CI 1.002-1.019, p = 0.011), higher likelihood for diagnosis for PCP (OR = 7.50,95% CI 1.288-43.687, p = 0.025), higher SOFA score at ICU admission (OR = 1.183,95% CI 1.012-1.383, p = 0.035), longer duration of CRRT (OR = 1.014,95% CI 1.001-1.028, p = 0.034) contributed to a higher mortality at ICU. The Cox Analysis for the cumulative survival of AKI 3 patients between the CRRT and non-CRRT groups shows no significant differences (p = 0.595). CONCLUSIONS: There is a high incidence of AKI in HIV-infected patients admitted in our ICU. Patients with severe AKI were more prone to be admitted for CRRT and have a consequent poor prognosis.

Acute Kidney Injury in Chinese HIV-Infected Patients: A Retrospective Analysis from the Intensive Care Unit.

To describe the epidemiology, outcomes, and risk factors of acute kidney injury (AKI) among human immunodeficiency virus (HIV)-infected patients admitted to the intensive care unit (ICU).We reviewed all the HIV-infected admissions to the ICU at Beijing Ditan hospital in the time span from June 2005 to May 2017 and collected demographic, clinical, and laboratory data for our sample. AKI was diagnosed and classified according to the Kidney Disease Improving Global Outcomes (KIDIGO) criteria. We analyzed the incidence of AKI and its associated mortality. The potential risk factors for severe AKI were also investigated in this study. A total of 225 HIV-infected patients were included in the final analysis. The incidences of no-AKI, AKI stage 1, AKI stage 2, and AKI stage 3, were 46.2% (104), 19.1% (43), 8.4% (19), and 26.2% (59), respectively. By logistic regression analysis, severe AKI (stages 2-3) was an important predicator for 60-day mortality with an odds ratio of 4.234. By multivariate analysis, a high acute physiology and chronic health evaluation, version II (APACHE-II) score (p = 0.024), low albumin (p < 0.031) at the first 24-h admission ICU, shock (p = 0.013), and bloodstream infection (p = 0.006) during hospitalization were all found to be significant risk factors for severe AKI. AKI is common in HIV-infected patients admitted to the ICU, and the mortality of patients with AKI stages 2-3 is significantly higher compared with those without such conditions. A high APACHE-II score and a lower albumin level at the first 24-h admission to ICU are significant predictors of severe AKI in this specific population. Shock and bloodstream infection during hospitalization can also lead to severe AKI.

Nonionic surfactant enhanced biodegradation of m-xylene by mixed bacteria and its application in biotrickling filter.

In this study, m-xylene biodegradation was examined in bacteria-water mixed solution and biotrickling filter (BTF) systems amended with the nonionic surfactant Tween 80. The mixed bacteria were obtained from the activated sludge of a coking plant through a multisubstrate acclimatization process. High-throughput sequencing analysis revealed that Rhodanobacter sp. was the dominant species among the mixed bacteria. In the bacteria-water mixed solution, the bacterial density increased with increasing Tween 80 concentration. Hence, Tween 80 could be utilized as substrate by the mixed bacteria. Tween 80, with concentrations of 50-100 mg L-1, could enhance the bioavailability of m-xylene and consequently improve the degradation efficiency of m-xylene. However, further increasing the initial concentration of Tween 80 would decrease the degradation efficiency of m-xylene. At concentrations exceeding 100 mg L-1, Tween 80 was preferentially degraded by the mixed bacteria over m-xylene. In BTF systems, when the m-xylene inlet concentration was 1200 mg m-3 and the empty bed residence time was 20 sec, the removal efficiency and elimination capacity of BTF1 with Tween 80 addition were at most 20% and 24% higher than those of BTF2 without Tween 80 addition. Overall, the integrated application of the mixed bacteria and surfactant was demonstrated to be a highly effective strategy for m-xylene waste gas treatment. IMPLICATIONS: The integrated application of mixed bacteria and surfactant was demonstrated to be a promising approach for the highly efficient removal of m-xylene. Surfactant can activate mixed bacteria to degrade m-xylene by increasing its bioavailability. Besides, surfactant can be utilized as carbon source by the mixed bacteria so that the growth of mixed bacteria can be promoted. It is expected that the integrated application of both technologies will become more common in future chemical industry.

Surfactant-enhanced biodegradation of crude oil by mixed bacterial consortium in contaminated soil.

This study evaluated the effects of two surfactants (i.e., Tween 80 and SDS) on biodegradation of crude oil by mixed bacterial consortium in soil-aqueous system. The mixed bacterial consortium was domesticated from the activated sludge of cooking plant through a progressive domestication process. High-throughput sequencing analysis revealed that Rhodanobacter sp. was the dominant bacteria. The higher CMCeff value for two surfactants was observed in soil-aqueous system compared with that in aqueous system, which was likely due to their adsorption onto soil particles. Either Tween 80 or SDS can be utilized as carbon source and promote the growth of mixed bacterial consortium. Further findings evidenced that the degradation of crude oil can be enhanced by adding either Tween 80 or SDS. The performance of Tween 80 was generally superior to SDS for the crude oil degradation. The highest crude oil degradation efficiency was 42.2 and 31.0% under the conditions of 5 CMCeff of Tween 80 and 2 CMCeff of SDS, respectively. Furthermore, the degradation efficiency of crude oil in remediation experiment (i.e., 77%) evidenced that the integration of adding Tween 80 and inoculating mixed bacterial consortium was effective for crude oil-contaminated soil decontamination.

Effects of silicon on Oryza sativa L. seedling roots under simulated acid rain stress.

Silicon (Si) has an important function in reducing the damage of environmental stress on plants. Acid rain is a serious abiotic stress factor, and Si can alleviate the stress induced by acid rain on plants. Based on these assumptions, we investigated the effects of silicon on the growth, root phenotype, mineral element contents, hydrogen peroxide (H2O2) and antioxidative enzymes of rice (Oryza sativa L.) seedling roots under simulated acid rain (SAR) stress. The results showed that the combined or single effects of Si and/or SAR on rice roots depend on the concentration of Si and the pH of the SAR. The combined or single effects of a low or moderate concentration of Si (1.0 or 2.0 mM) and light SAR (pH 4.0) enhanced the growth of rice roots, and the combined effects were stronger than those of the single treatment. A high concentration of Si (4.0 mM) or severe SAR (pH 2.0) exerted deleterious effects. The incorporation of Si (1.0, 2.0 or 4.0 mM) into SAR with pH 3.0 or 2.0 promoted the rice root growth, decreased the H2O2 content, increased the Si concentration and the superoxide dismutase (SOD), catalase (CAT), peroxidase (POD) and ascorbate peroxidase (APX) activities, maintained the balance of mineral element (K, Ca, Mg, Fe, Zn, and Cu) concentrations in the roots of rice seedlings compared with SAR alone. The alleviatory effects observed with a moderate concentration of Si (2.0 mM) were better than the effects obtained with a low or high concentration of Si (1.0 or 4.0 mM). The observed effects were due to disruptions in the absorption and utilization of mineral nutrients and impacts on the activity of antioxidant enzymes in roots, and this conclusion suggests that the degree of rice root damage caused by acid rain might be attributed to not only acid rain but also the level of Si in the soil.

Silicon alleviates simulated acid rain stress of Oryza sativa L. seedlings by adjusting physiology activity and mineral nutrients.

Silicon (Si) has been a modulator in plants under abiotic stresses, such as acid rain. To understand how silicon made an effect on rice (Oryza sativa L.) exposed to simulated acid rain (SAR) stress, the growth, physiologic activity, and mineral nutrient content in leaves of rice were investigated. The results showed that combined treatments with Si (1.0, 2.0, or 4.0 mM) and SAR (pH 4.0, 3.0, or 2.0) obviously improved the rice growth compared with the single treatment with SAR. Incorporation of Si into SAR treatment decreased malondialdehyde (MDA) content; increased soluble protein and proline contents; promoted CAT, POD, SOD, and APX activity; and maintained the K, Ca, Mg, Fe, Zn, Cu content balance in leaves of rice seedlings under SAR stress. The moderate concentration of Si (2.0 mM) was better than the low and high concentration of Si (1.0 and 4.0 mM). Therefore, application of Si could be a better strategy for maintaining the crop productivity in acid rain regions.

Use of Dexmedetomidine for Prophylactic Analgesia and Sedation in Patients With Delayed Extubation After Craniotomy: A Randomized Controlled Trial.

BACKGROUND: We conducted a randomized trial to evaluate the efficacy and safety of dexmedetomidine for prophylactic analgesia and sedation in patients with delayed extubation after craniotomy. METHODS: From June 2012 to July 2014, 150 patients with delayed extubation after craniotomy were randomized 1:1 and were assigned to the dexmedetomidine group that received a continuous infusion of 0.6 µg/kg/h (10 µg/mL) or the control group that received a maintenance infusion of 0.9% sodium chloride for injection. The mean percentage of time under optimal sedation (SAS3-4), the percentage of patients who required rescue with propofol/fentanyl, and the total dose of propofol/fentanyl required throughout the course of drug infusion, as well as VAS, HR, MAP, and SpO2 were recorded. RESULTS: The percentage of time under optimal sedation was significantly higher in the dexmedetomidine group than in the control group (98.4%±6.7% vs. 93.0%±16.2%, P=0.008). The VAS was significantly lower in the dexmedetomidine group than in the control group (1.0 vs. 4.0, P=0.000). The HR and mean BP were significantly lower in the dexmedetomidine group than in the control group at all 3 time points (before endotracheal suctioning, immediately after extubation, and 30 min after extubation). No significant difference in SpO2 was observed between the 2 groups. For hemodynamic adverse events, patients in the dexmedetomidine group were more likely to develop bradycardia (5.3% vs. 0%, P=0.043) but had a lower likelihood of tachycardia (2.7% vs. 18.7%, P=0.002). CONCLUSIONS: Dexmedetomidine may be an effective prophylactic agent to induce sedation and analgesia in patients with delayed extubation after craniotomy. The use of dexmedetomidine (0.6 µg/kg/h) infusion does not produce respiratory depression, but may increase the incidence of bradycardia.

Variations in organic carbon, aggregation, and enzyme activities of gangue-fly ash-reconstructed soils with sludge and arbuscular mycorrhizal fungi during 6-year reclamation.

Mining activities can cause drastic disturbances in soil properties, which adversely affect the nutrient cycling and soil environment. As a result, many efforts have been made to explore suitable reclamation strategies that can be applied to accelerate ecology restoration. In this study, we reconstructed mine soils with fly ash, gangue, sludge, planted ryegrass, and inoculated arbuscular mycorrhizal fungi (AMF) in Pangzhuang mine of Xuzhou during 2009 to 2015. The soil aggregation process, enzyme activities (i.e., invertase, urease and acid phosphatase activities), soil organic carbon (SOC) as well as other soil nutrients such as nitrogen, phosphorus, and potassium contents of the reconstructed mine soils were monitored during 6-year reclamation. The integrated application of sludge and AMF led to a promising reclamation performance of mining areas, in which soil aggregate stability, enzyme activities, SOC, and ryegrass biomass were effectively enhanced. The micro-aggregates (< 0.25 mm) decreased with the increase of macro-aggregates (> 0.25 mm) during the reclamation, indicating that macro-aggregates were gradually formed from micro-aggregates during the pedogenesis of reconstructed mine soils. The correlation analysis shows that SOC contents in aggregate fraction of 0.25∼0.5 mm were correlated with aggregate distribution and enzyme activities. Enzyme activities, however, were not significantly correlated with aggregate distribution. The outcomes from the present study could enrich our understanding on soil property changes in pedogenesis process of reconstructed mine soils, and meanwhile, the employment of sludge combined with AMF is suggested to be an effective alternative for the mine soil reclamation.

Agreement of measured and calculated serum osmolality during the infusion of mannitol or hypertonic saline in patients after craniotomy: a prospective, double-blinded, randomised controlled trial.

BACKGROUND: Mannitol and hypertonic saline are used to ameliorate brain edema and intracranial hypertension during and after craniotomy. We hypothesized that the agreement of measured and calculated serum osmolality during the infusion of hypertonic saline would be better than mannitol. The objective was to determine the accuracy of serum osmolality estimation by different formulas during the administration of hyperosmolar agent. METHODS: A prospective, randomized, double-blinded, controlled trial was conducted in a 30-bed neurosurgical intensive care unit at a university hospital. Thirty-five adult patients requiring the use of hyperosmolar agents for prevention or treatment of brain edema after elective craniotomy were enrolled, and randomly assigned 1:1 to receive 125 mL of either 20 % mannitol (mannitol group) or 3.1 % sodium chloride solution (hypertonic saline group) in 15 min. Serum osmolality, serum sodium and potassium concentration, blood urea nitrogen and blood glucose concentration were measured during the study period. The primary outcome was the agreement of measured and estimated serum osmolality during the infusion of the two experimental agents. We used Bland and Altman's limits of agreement analysis to clarify the accuracy of estimated serum osmolality. Bias and upper and lower limits of agreement of bias were calculated. RESULTS: For each formula, the bias was statistically lower in hypertonic saline group than mannitol group (p < 0.001). Within group comparison showed that the lowest bias (6.0 [limits of agreement: -18.2 to 30.2] and 0.8 [-12.9 to 14.5] mOsml/kg in mannitol group and hypertonic saline group, respectively) was derived from the formula '2 × ([serum sodium] + [serum potassium]) + [blood urea nitrogen] + [blood glucose]'. CONCLUSIONS: Compared to mannitol, a better agreement between measured and estimated serum osmolality was found during the infusion of hypertonic saline. This result indicates that, if hypertonic saline is chosen to prevent or treat brain edema, calculated serum osmolality can be used as a reliable surrogate for osmolality measurement. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02037815.

Combination of extracorporeal membrane oxygenation and continuous renal replacement therapy in critically ill patients: a systematic review.

INTRODUCTION: Extracorporeal membrane oxygenation (ECMO) is used in critically ill patients presenting acute cardiac and/or pulmonary dysfunctions, who are at high risk of developing acute kidney injury and fluid overload. Continuous renal replacement therapy (CRRT) is commonly used in intensive care units (ICU) to provide renal replacement and fluid management. We conducted a review to assess the feasibility, efficacy and safety of the combination of ECMO and CRRT and to illustrate the indications and methodology of providing renal replacement therapy during the ECMO procedure. METHOD: We searched for all published reports of a randomized controlled trial (RCT), quasi-RCT, or other comparative study design, conducted in patients undergoing ECMO plus CRRT. Two reviewers independently selected potential studies and extracted data. We used the modified Jadad scale and the Newcastle-Ottawa for quality assessment of RCTs and non-RCTs, respectively. Statistical analyses were performed using RevMan 5.2. RESULTS: We identified 19 studies meeting the eligibility criteria (seven cohort, six case control, one historically controlled trial and five studies of technical aspects). There are three major methods for performing CRRT during ECMO: 'independent CRRT access', 'introduction of a hemofiltration filter into the ECMO circuit (in-line hemofilter)' and 'introduction of a CRRT device into the ECMO circuit'. We conducted a review with limited data synthesis rather than a formal meta-analysis because there could be greater heterogeneity in a systematic review of non-randomized studies than that of randomized trials. For ECMO survivors receiving CRRT, overall fluid balance was less than that in non-CRRT survivors. There was a higher mortality and a longer ECMO duration when CRRT was added, which may reflect a relatively higher severity of illness in patients who received ECMO plus CRRT. CONCLUSIONS: The combination of ECMO and CRRT in a variety of methods appears to be a safe and effective technique that improves fluid balance and electrolyte disturbances. Prospective studies would be beneficial in determining the potential of this technique to improve the outcome in critically ill patients.