Prevention of urinary tract infection using a silver alloy hydrogel-coated catheter in critically ill patients: A single-center prospective randomized controlled study.

Background: A new type of silver alloy hydrogel-coated (SAH) catheter has been shown to prevent bacterial adhesion and colonization by generating a microcurrent, and to block the retrograde infection pathway. However, these have only been confirmed in ordinary patients. This study aims to evaluate the effectiveness of a SAH catheter for preventing urinary tract infections in critically ill patients. Methods: This was a prospective single-center, single-blind, randomized, controlled study. A total of 132 patients requiring indwelling catheterization in the intensive care unit (ICU) of the First Affiliated Hospital of the University of Science and Technology of China between October 2022 and February 2023 and who met the study inclusion/exclusion criteria were randomly divided into two groups. Patients in the SAH catheter group received a SAH catheter, while patients in the conventional catheter group received a conventional siliconized latex Foley catheter. The main outcome measure was the incidence of catheter-associated urinary tract infections (CAUTIs). Secondary outcome indicators included urine positivity for white blood cells and positive urine cultures on 3 days, 7 days, 10 days, and 14 days after catheterization, number of viable bacteria in the catheter biofilm on day 14, pathogenic characteristics of positive urine cultures, length of ICU stay, overall hospital stay, ICU mortality, and 28-day mortality. All the data were compared between the two groups. Results: A total of 68 patients in the conventional catheter group and 64 patients in the SAH catheter group were included in the study. On day 7 after catheter placement, the positivity rate for urinary white blood cells was significantly higher in the conventional catheter group than in the SAH catheter group (33.8% vs. 15.6%, P=0.016). On day 10, the rates of positive urine cultures (27.9% vs. 10.9%, P=0.014) and CAUTIs (22.1% vs. 7.8%, P=0.023) were significantly higher in the conventional catheter group than in the SAH catheter group. On day 14, the numbers of viable bacteria isolated from the catheter tip ([3.21±1.91]×106 colony-forming units [cfu]/mL vs. [7.44±2.22]×104 cfu/mL, P <0.001), balloon segment ([7.30±1.99]×107 cfu/mL vs. [3.48±2.38]×105 cfu/mL, P <0.001), and tail section ([6.41±2.07]×105 cfu/mL vs. [8.50±1.46]×103 cfu/mL, P <0.001) were significantly higher in the conventional catheter group than in the SAH catheter group. The most common bacteria in the urine of patients in both groups were Escherichia coli (n=13) and Pseudomonas aeruginosa (n=6), with only one case of Candida in each group. There were no significant differences between the two groups in terms of ICU hospitalization time, total hospitalization time, ICU mortality, and 28-day mortality. Conclusion: SAH catheters can effectively inhibit the formation of catheter-related bacterial biofilms in critically ill patients and reduce the incidence of CAUTIs, compared with conventional siliconized latex Foley catheters; however, regular replacement of the catheter is still necessary.

Concurrent elimination and stepwise recovery of Pb(II) and bisphenol A from water using ß-cyclodextrin modified magnetic cellulose: adsorption performance and mechanism investigation.

Coexistence of heavy metals and endocrine disrupting compounds in polluted water with competitive adsorption behavior necessitates design of tailored adsorbents. In this work, ß-cyclodextrin modified magnetic rice husk-derived cellulose (ß-CD@MRHC) which can provide independent functional sites for effectively binding the above two types of contaminants was synthesized and used for Pb(II) and BPA elimination in both unit and multivariate systems. Characterizations results confirmed successful ß-CD grafting and Fe3O4 loading, and the ß-CD@MRHC had excellent magnetic property for its effectively recovery from water, which was not affected by the adsorption of pollutants. The ß-CD@MRHC possessed superior adsorption performance with maximal Pb(II)/BPA uptake of 266.2 or 412.8 mg/g, severally, and the adsorption equilibrium was fleetly reached in 30 and 7.5 min. Moreover, the ß-CD@MRHC could accomplish synergetic Pb(II) and BPA elimination through averting their competitive behaviors owing to diverse capture mechanisms for Pb(II) (ion exchange, complexation and electrostatic attraction) and BPA (hydrogen bonding and host-guest inclusion). Furthermore, after three cycles of step-wise desorption, the binding of Pb(II) as well as BPA byß-CD@MRHC dropped slightly in dualistic condition. In summary, ß-CD@MRHC was a promising tailored adsorbent to practical application for simultaneously removing heavy metals and organic matters from wastewater with high-performance magnetic recovery.

[Diagnostic value of detection of pathogens in bronchoalveolar lavage fluid by metagenomics next-generation sequencing in organ transplant patients with pulmonary infection].

OBJECTIVE: To evaluate the diagnostic value of metagenomics next-generation sequencing (mNGS) in detecting pathogens in bronchoalveolar lavage fluid (BALF) for pulmonary infection in solid organ transplant patients in intensive care unit (ICU). METHODS: A retrospective study was conducted, the BALF samples from 46 patients with post organ transplant pneumonia/suspected pneumonia admitted to the Department of Critical Care Medicine of the First Affiliated Hospital of University of Science and Technology of China from August 2018 to August 2021 were collected, all tested by simultaneous mNGS and conventional comprehensive microbial test (CMT), and the results of CMT were used as the reference standard to compare the differences in the diagnostic value of mNGS and CMT for pulmonary infections in solid organ transplant patients, and to analyze the diagnostic value of mNGS for mixed infections. RESULTS: (1) Pneumonia pathogens: a total of 31 pathogens were detected in 35 patients, including bacteria (16 species), fungi (9 species) and viruses (6 species). Among them, 25 pathogens were detected by mNGS and CMT, and only 19 pathogens were detected by mNGS. Among the microorganisms isolated by mNGS method, the detection rates of Pseudomonas aeruginosa, Acinetobacter baumannii and Klebsiella pneumoniae were higher [51.4% (18/35), 42.9% (15/35), 31.4% (11/35), respectively]; Candida albicans, Aspergillus and Pneumocystis carinii were the most commonly detected fungi [31.4% (11/35), 22.9% (8/35), 22.9% (8/35), respectively]; 20 patients were positive for the virus, and the most commonly detected viruses were cytomegalovirus, herpesvirus and EB virus [28.6% (10/35), 20.0% (7/35), 17.1% (6/35), respectively]. In addition, one case of Brucella was detected by mNGS. (2) Diagnostic efficiency: as far as bacterial detection is concerned, 20 cases of negative results were obtained by CMT detection of 35 samples included in the study, and a total of 10 cases of positive results were obtained by mNGS detection of negative samples; the percentage of mNGS positive samples was significantly higher than that of CMT positive samples [odds ratio (OR) = 5.5, 95% confidence interval (95%CI) = 1.2-24.8, P = 0.02]. When compared with CMT, the sensitivity and specificity of mNGS were 93.3% and 50.0%, and the positive predictive value (PPV) and negative predictive value (NPV) were 58.3%, 91.1%. As far as fungal detection was concerned, there was no significant difference in the percentage of positive samples between the two methods (OR = 1.5, 95%CI = 0.5-4.2, P = 0.60); the sensitivity and specificity of mNGS were 72.2% and 64.7%, and the PPV and NPV were 68.4%, 68.8%; CMT test of the 35 included samples produced 17 negative results, and mNGS test of the negative samples produced 6 positive results. A total of 20 patients tested positive for the virus by mNGS. In addition, 23 patients (65.7%) were diagnosed with pulmonary mixed infection. CONCLUSIONS: The use of mNGS to detect pathogens in BALF can improve the sensitivity and specificity of bacterial identification of pulmonary infection in critically ill organ transplant patients, and mNGS has obvious advantages in detecting virus and identifying mixed infections.

Multi-component adsorption of Pb(II), Cd(II) and Ni(II) onto microwave-functionalized cellulose: Kinetics, isotherms, thermodynamics, mechanisms and application for electroplating wastewater purification.

Herein, microwave-functionalized cellulose derived from rice husk was cost-effectively prepared and employed for Pb(II), Cd(II) and Ni(II) elimination in mono- and multi-component systems. Benefiting from microwave irradiation, the functionalized process was achieved in 6.5 min and the resultant RHMW-X possessed remarkably high adsorption capacities of 295.20 mg/g for Pb(II), 151.51 mg/g for Cd(II) and 72.80 mg/g for Ni(II) within the equilibrium time of 30 min. Noticeably, the metal ions adsorption rate and capacity in binary and ternary systems were lower than that of unary systems. The coexistence of Cd(II) and Ni(II) significantly slowed down the Pb(II) adsorption in binary and ternary systems, while Pb(II) exhibited the most obvious influence on the metal ions uptake in the multi-component systems. FT-IR and XPS results revealed that both ion exchange and chelation were functioned in the metal ions uptake, while physical interaction was also involved in the adsorption process. Moreover, the RHMW-X possessed favorable recyclability with slight adsorption efficiency decline during five cycles in different systems. Particularly, the RHMW-X could effectively purify actual industrial wastewater containing Pb(II), Cd(II) and Ni(II) for meeting regulatory requirements. This work facilitates the omnidirectional improvement of adsorbents for the de-pollution of practical heavy metals wastewater.

A combined system of microwave-functionalized rice husk and poly-aluminium chloride for trace cadmium-contaminated source water purification: Exploration of removal efficiency and mechanism.

Cadmium is highly poisonous to mammals and related water pollution incidents are increasing world-widely. Here, the clean-up of trace Cd(II) by a combined process of microwave-functionalized rice husk (RHMW-M) and poly aluminium chloride (PAC) was investigated for the first time, with the exploration of removal mechanism and efficacy. Microwave irradiation was found to be a new approach to achieve the functionalized procedure, which could decrease the processing time from 2.5 h to 390 s with the Cd(II) uptake of the outcome product soaring from 137.16 mg/g to 191.32 mg/g. The ultra-rapidly prepared RHMW-M exhibited a fast adsorption equilibrium within 30 min over a wide pH range of 5.0-8.0, and the FT-IR and XPS studies confirmed that both ion exchange and chelation were functioned in the Cd(II) uptake process. Controlled by the turbidity threshold of drinking water treatment plant, the feasible dosage of RHMW-M in the absence and presence of 30 mg/L PAC increased from 30 to 760 mg/L, which could effectively deal with the trace Cd(II) at the concentration from 33 µg/L up to 0.933 mg/L, exhibiting much better performance than traditional alkali precipitation. Predictably, this simple and scalable RHMW-M/PAC system could afford a promising end-of-pipe solution for heavy-metal contamination.

Utilization of rice husks functionalized with xanthates as cost-effective biosorbents for optimal Cd(II) removal from aqueous solution via response surface methodology.

Pristine rice husk (RH), a kind of agricultural waste based biosorbent, was chemically modified by introducing sulfur-bearing groups with the CS2 treatment under caustic medium. Using response surface methodology (RSM), the interactive effects of three preparation variables on the cadmium uptake and material yield of xanthate-modified rick husk (RH-X) were investigated, and two quadratic regression models were developed to correlate the preparation parameters to the two responses. Through process optimization, the optimal RH-X was finally obtained under the optimum synthesis conditions (i.e., 1.00 CS2-RH ratio, 60.00min xanthation contact time and 18.50°C xanthation temperature), resulting in 138.85mgg-1 of cadmium uptake, and 68.63% of RH-X yield, strictly similar to the values predicted from the models, with extremely small errors of 0.85 and 0.96%, respectively. Overall, cheap and abundant raw materials, low-cost and easily-controlled preparation and excellent cadmium adsorption ability can make RH-X a preferred biosorbent for wastewater decontamination.

Characteristic variation and original analysis of emergent water source pollution accidents in China between 1985 and 2013.

China has suffered various water source pollution incidents in the past decades, which have resulted in severe threats to the safety of the water supply for millions of residents. From the aspects of quantity fluctuation, temporal volatility, regional inequality, pollutant category variation, and accident type differences, this study first characterizes the current status of water source contaminations in China by analyzing 340 pollution events for the period spanning from 1985 to 2013. The results show a general increase in the number of accidents during the period 1985-2006 and then a rapid decline starting in 2007. Spring and summer are high-incidence seasons for pollution, and the accident rate in developed southeastern coastal areas is far higher than that in the northwestern regions. Hazardous chemicals and petroleum are the most frequently occurring pollutants, whereas heavy metals and tailings are becoming emerging contaminants during occasional pollutions. Most of the accidents that occurred before 2005 were blamed on illegal emissions or traffic accidents; however, leakage in production has gradually become a major accident type in the past decade. Then, in combination with government actions and policy constraints, this paper explores the deep inducements and offers valuable insight into measures that should be taken to ensure future prevention and mitigation of emergent source water pollution.

A triangular fuzzy TOPSIS-based approach for the application of water technologies in different emergency water supply scenarios.

Because of the increasing frequency and intensity of unexpected natural disasters, providing safe drinking water for the affected population following a disaster has become a global challenge of growing concern. An onsite water supply technology that is portable, mobile, or modular is a more suitable and sustainable solution for the victims than transporting bottled water. In recent years, various water techniques, such as membrane-assisted technologies, have been proposed and successfully implemented in many places. Given the diversity of techniques available, the current challenge is how to scientifically identify the optimum options for different disaster scenarios. Hence, a fuzzy triangular-based multi-criteria, group decision-making tool was developed in this research. The approach was then applied to the selection of the most appropriate water technologies corresponding to the different emergency water supply scenarios. The results show this tool capable of facilitating scientific analysis in the evaluation and selection of emergency water technologies for enduring security drinking water supply in disaster relief.

Multi-stage ranking of emergency technology alternatives for water source pollution accidents using a fuzzy group decision making tool.

Due to the increasing number of unexpected water source pollution events, selection of the most appropriate disposal technology for a specific pollution scenario is of crucial importance to the security of urban water supplies. However, the formulation of the optimum option is considerably difficult owing to the substantial uncertainty of such accidents. In this research, a multi-stage technical screening and evaluation tool is proposed to determine the optimal technique scheme, considering the areas of pollutant elimination both in drinking water sources and water treatment plants. In stage 1, a CBR-based group decision tool was developed to screen available technologies for different scenarios. Then, the threat degree caused by the pollution was estimated in stage 2 using a threat evaluation system and was partitioned into four levels. For each threat level, a corresponding set of technique evaluation criteria weights was obtained using Group-G1. To identify the optimization alternatives corresponding to the different threat levels, an extension of TOPSIS, a multi-criteria interval-valued trapezoidal fuzzy decision making technique containing the four arrays of criteria weights, to a group decision environment was investigated in stage 3. The effectiveness of the developed tool was elaborated by two actual thallium-contaminated scenarios associated with different threat levels.

A novel two-stage evaluation system based on a Group-G1 approach to identify appropriate emergency treatment technology schemes in sudden water source pollution accidents.

Sudden water source pollution resulting from hazardous materials has gradually become a major threat to the safety of the urban water supply. Over the past years, various treatment techniques have been proposed for the removal of the pollutants to minimize the threat of such pollutions. Given the diversity of techniques available, the current challenge is how to scientifically select the most desirable alternative for different threat degrees. Therefore, a novel two-stage evaluation system was developed based on a circulation-correction improved Group-G1 method to determine the optimal emergency treatment technology scheme, considering the areas of contaminant elimination in both drinking water sources and water treatment plants. In stage 1, the threat degree caused by the pollution was predicted using a threat evaluation index system and was subdivided into four levels. Then, a technique evaluation index system containing four sets of criteria weights was constructed in stage 2 to obtain the optimum treatment schemes corresponding to the different threat levels. The applicability of the established evaluation system was tested by a practical cadmium-contaminated accident that occurred in 2012. The results show this system capable of facilitating scientific analysis in the evaluation and selection of emergency treatment technologies for drinking water source security.

[The analysis for Raman spectra of Nd:YVO4].

The factor group symmetry analysis method was used to analyse the Raman spectra of neodymium-doped yttrium orthoanadate Nd:YVO4 which were measured at room temperature with different geometrical configurations. All the Raman peaks were assigned on the basis of the group theory and lattice dynamics thoery. According to the peak numbers of the Raman spectra, we concluded that the primitive cell of Nd:YVO4 contains four formula units.

Improvement of passive Q-switching performance reached with a new Nd-doped mixed vanadate crystal Nd:Gd0.64Y0.36VO4.

Passive Q-switching performance was found to be greatly improved by use of a new Nd-doped mixed vanadate crystal Nd:Gd0.64Y0.36VO4 compared with that achieved with Nd:YVO4 and Nd:GdVO4. At an absorbed pump power of 12 W, an average output power of 2.78 W was obtained at a pulse repetition frequency of 15.4 kHz with an optical conversion efficiency of 23.2%, and the slope efficiency was determined to be 45.5%. The resulting pulse energy, peak power, and pulse width were 181 microJ, 26.6 kW, and 6.8 ns, respectively.