Understanding the structures and interactions in gaseous mixtures of water-alcohol by high-resolution infrared spectroscopy.

Interactions of water and chemical or bio-compound have a universal concern and have been extensively studied. For spectroscopic analysis, the complexity and the low resolution of the spectra make it difficult to obtain the spectral features showing the interactions. In this work, the structures and interactions in gaseous water and water-alcohol mixtures were studied using high-resolution infrared (HR-IR) spectroscopy. The spectral features of water clusters of different sizes, including dimer, trimer, tetramer and pentamer, were observed from the measured spectra of the samples in different volume concentrations, and the interactions of water and methanol/ethanol in the mixtures were obtained. In the analysis, a method based on principal component analysis was used to separate the overlapping spectra. In water-alcohol mixtures, when water is less, water molecules tend to interact with the OH groups on the exterior of the alcohol aggregate, and with the increase of water, a water cage forms around the aggregates. Furthermore, the ratio of the molecule number of methanol in the aggregate to that of water in the cage is around 1:2.3, and the ratio for ethanol is about 1:3.2.

Antibiotic resistance of Escherichia coli isolated from food and clinical environment in China from 2001 to 2020.

Antibiotics are widely used in China's aquaculture, agricultural, and clinical settings and can lead to antibiotic resistance in various pathogens. Although the pooled prevalence estimate (PPE) and antibiotic resistance of Escherichia coli (E. coli) in food and clinical settings has been extensively studied, a comprehensive analysis of the published literature is lacking. We conducted a comprehensive search for research indicators for 2001-2020 in eight major Chinese and English literature databases. Antibiotic PPE and resistance trends of 5933 and 29,451 E. coli isolates were screened and analysed in 35 food studies (total 1821) and 62 clinical studies (total 5159). E. coli strains derived from food had the highest antibiotic resistance rate to tetracycline (TET, 71.3 %), followed by trimethoprim-sulfamethoxazole (SXT, 62.5 %) and cefazolin (CFZ, 36.2 %). E. coli strains isolated from clinical environments were highly resistant to piperacillin (PIP, 71.7 %), TET (68.3 %) and CFZ (60.9 %), consistent with foodborne E. coli drug resistance patterns. E. coli strains isolated from food and clinical samples collected in laboratories carry multiple antibiotic resistance genes (ARGs), such as blaTEM, gryA, gryB, sul1, and tetA, making E. coli a reservoir of ARGs. This study highlights the presence of drug-resistant E. coli pathogens and ARGs in food and clinical environments.

The Preparation and Dust Suppression Performance Evaluation of Iron Ore Tailing-Based Cementitious Composites.

In order to comprehensively utilize iron ore tailings (IOTs), the possibility of using IOTs as raw materials for the preparation of cementitious composites (IOTCCs) was investigated, and IOTCC was further applied to mine interface pollution control. The mechanical properties, hydration products, wind erosion resistance, and freeze-thaw (F-T) cycle resistance of IOTCCs were evaluated rigorously. The activity index of iron tailings increased from 42% to 78% after grinding for 20 s. The IOTCC was prepared by blending 86% IOT, 10% ground granulated blast-furnace slag (GGBS), and 4% cement clinker. Meanwhile, the hydration products mainly comprised ettringite, calcium hydroxide, and C-S-H gel, and they were characterized via XRD, IR, and SEM. It was observed that ettringite and C-S-H gel were principally responsible for the strength development of IOTCC mortars with an increase in curing time. The results show that the kaolinite of the tailings was decomposed largely after mechanical activation, which promoted the cementitious property of IOT.

Spatiotemporal dynamics, traceability analysis, and exposure risks of antibiotic resistance genes in PM2.5 in Handan, China.

Fine particulate matter (PM2.5) seriously affects environmental air quality and human health, and antibiotic resistance genes (ARGs) in PM2.5 posed a great challenge to clinical medicine. The year of 2013-2017 was an important 5-year period for the implementation of Air Pollution Prevention and Control Action Plan (APPCAP) in China. Here, we took Handan, a PM2.5 polluted city in northern China, as the research object and analyzed ARGs in PM2.5 in winter (January) from 2013 to 2017. The results showed that the abundance of ARGs was the highest in 2013 (3.7 × 10-2 copies/16S rRNA), and ARGs were positively correlated with air quality index (AQI) (r = 0.328, P < 0.05) and PM2.5 concentration (r = 0.377, P = 0.020 < 0.05) in the 5-year period. The ARGs carried by PM2.5 in four functional regions of sewage treatment plant, steel works, university, and park showed that sul1 and qepA had higher abundance in each functional region, and the total ARG abundance in sewage treatment plant (1.3 × 10-1 copies/16S rRNA) was the highest, while lowest in park (2.0 × 10-3 copies/16S rRNA). Potential source contribution function (PSCF) and concentration-weighted trajectory (CWT) model were used to trace the pollutants at the sampling points, which indicated that the surrounding cities contributed more than quarter to the sampling points. Therefore, regional transportation reduces the spatial distribution difference of ARGs in PM2.5. The exposure dose of ARGs in different functional regions illustrated that the total inhaled dose of ARGs in sewage treatment plant (1.7 × 105 copies/d) was the highest, while lowest in park (3.2 × 104 copies/d). This study is of great significance for assessing the distribution and sources of ARGs under the clean air initiative in China.

Passivation of multiple heavy metals in lead-zinc tailings facilitated by straw biochar-loaded N-doped carbon aerogel nanoparticles: Mechanisms and microbial community evolution.

Heavy metal (HM) soil pollution has become an increasingly serious problem with the development of industries. Application of biochar in HMs remediation from contaminated environment has attracted considerable research attention during the past decade. Although the mechanism of HMs passivation with biochar has been investigated, effects and mechanisms of interaction among soil-indigenous microbes and novel carbon matrix composites for HMs adsorption and passivation are still unclear. Four different biochar-loaded aerogels, namely, BNCA-1-600, BNCA-1-900, BNCA-2-600, and BNCA-2-900, were synthesized in this study. Adsorption capacity of four kinds of synthetic materials and two types of contrast biochars (BC600 and BC900) to HMs in aqueous solution, passivation capacity of HMs in soil, and effects on soil organic matter and microbial community were explored. Results showed that BNCA-2-900 exhibits excellent adsorption property and a maximum removal capacity of 205.07 mg·g-1 at 25 °C for Pb(II), 105.56 mg·g-1 for Cd(II), and 137.89 mg·g-1 for Zn(II). Leaching concentration of HMs in contaminated soil can meet the national standard of China (GB/T 5085.3-2007) within 120 days. Results of this study confirmed that the additive BNCA-2-900 and coexistence of indigenous microorganisms can effectively reduce bioavailability of HMs. Another potential mechanism may be to remove the passivation of HMs by porous structure and surface functional groups as well as improve the content of organic matter and microbial abundance. The research results may provide a novel perceptive for the development of functional materials and strategies for eco-friendly and sustainable multiple HMs remediation in contaminated soil and water by using a combination of carbon matrix composites and soil-indigenous microorganisms.

Identification of the Charge Transfer Channel in Cobalt Encapsulated Hollow Nitrogen-Doped Carbon Matrix@CdS Heterostructure for Photocatalytic Hydrogen Evolution.

Water splitting to H2 by photocatalysis remains an effective strategy to alleviate the energy crisis. Unfortunately, single-component photocatalyst still suffers from sluggish reaction kinetics. In this work, a noble-metal free photocatalytic system of nitrogen-doped carbon@Co embedded in carbon nanotubes (NC@Co-NCT)/cadmium sulfide (CdS) is fabricated by coupling CdS nanorods with the metal-organic framework-derived Co encapsulated nitrogen-doped carbon (NC) material. The optimal photocatalytic activity of NC@Co-NCT/CdS is determined to be 3.8 mmol h-1  g-1 , which is ≈5.8 times of CdS. By combining the experimental evidences and density functional theory calculations, a novel photoelectron transfer channel in the heterojunction interfaces is revealed, expediting the migration and separation of photo-induced charge carriers of CdS. Moreover, the presence of Co nanoclusters can act as the active sites, boosting the H2 evolution reaction. This study can present a new avenue to design advanced photocatalysts with high-efficiency electrons and holes separation.

Biodegradation of phthalic acid esters (PAEs) by Cupriavidus oxalaticus strain E3 isolated from sediment and characterization of monoester hydrolases.

Phthalic acid esters (PAEs) are teratogenic and carcinogenic and mainly metabolized by microorganisms in sediment. A novel strain, Cupriavidus oxalaticus strain E3, was isolated and characterized from sediment for PAEs degradation. The transformation of dibutyl phthalate (DBP) and bis(2-ethylhexyl) phthalate (DEHP) as the sole carbon source by strain E3 was systematically studied in the darkness through the kinetic studies and analysis of intermediates. After the initial lag pause of 5 h-8 h, the strain efficiently degraded 87.4%-94.4% of DBP and 82.5%-85.6% of DEHP at an initial amount of each phthalate of 200 mg/L after 60 h of incubation. The biodegradation rate of DBP and DEHP followed a first-order kinetic model, and degradation rate constants (k) of them by E3 were 1.37 and 0.86 d-1, respectively. Gas chromatography-mass spectrometry (GC-MS) results revealed that the tentative PAEs degradation pathway, included the transformation from PAEs to phthalic acid (PA) and the complete mineralization of PA. In the phase of PAEs to PA, DBP with short sides reduced the chain length via hydrolyzation, and DEHP with long sides reduced the chain length via hydrolyzation and ß-oxidation. The 3D model of monoester hydrolase from C. oxalaticus was predicted and used for docking with mono-2-ethylhexyl phthalate (MEHP) and mono-n-butyl phthalate (MBP). The docking results showed that the conserved catalytic triplet structure (Ser140, His284, and Asp254) acted as active sites and participated in degrading PMEs. This study provided novel insights into the mechanisms of PAEs degradation at a molecular level and widened the scope of functional bacteria by isolating strain E3.

Electrodeposited Co-Substituted LaFeO3 for Enhancing the Photoelectrochemical Activity of BiVO4.

Co-substituted LaFeO3 was electrodeposited on the surface of BiVO4 as a co-catalyst to enhance the water splitting performance. Compared to bare BiVO4, the BiVO4/Co-LaFeO3 composite photoanode shows a water oxidation photocurrent of 3.4 mA/cm2 at 1.23 V versus reverse hydrogen electrode, accompanied by a notable cathodic shift in the onset potential for 300 mV. Combined optical and electrochemical characterizations show that the solid/electrolyte charge transfer efficiency of BiVO4 are dramatically improved by the incorporation of Co-substituted LaFeO3. From the surface kinetic study of charge carriers by intensity-modulated photocurrent spectroscopy, a suppressed surface recombination rate constant is observed and the enhanced photoelectrochemical water splitting performance observed in the BiVO4/Co-LaFeO3 photoanode is attributed to the surface passivation effect of Co-substituted LaFeO3.

Adsorption mechanism of lead ions on porous ceramsite prepared by co-combustion ash of sewage sludge and biomass.

This study attempted to synthesize a novel ceramsite with excellent adsorption property compositing through the co-combustion of biomass and sewage sludge ash (CBSA), gasification of coal fly ash (GCFA) and sewage sludge (SS) to dispose wastewater contaminated by Pb (II). The optimum preparation conditions included a CBSA/SS/GCFA ratio of 70:18:12, preheating at 480 °C, and sintering at 1060 °C for 15 min. The basic and environmental characteristics of the novel ceramsite meet specific standards requirements. The removal rate could reach 99.9% under optimum conditions in a high-concentration solution, and the novel ceramsite could be reused 6 times and maintain in high remove rate. The adsorption mechanism was determined to be as follows: (1) Ceramsite features a mesoporous structure with an abundance of pores on which cationic exchange could occur. (2) Pb (II) enters the pores of the adsorbent and are attracted by anionic groups to deposit on the surface of ceramsite. (3) A large amount of Pb (II) bonds with SiO or AlOSiO to embed in the matrix frame of the adsorbent; the rest of the metal forms precipitates on the frame layer or [PO4].

Synthesis of Zeolite from Carbothermal Reduction Electrolytic Manganese Residue for the Removal of Macrolide Antibiotics from Aqueous Solution.

Zeolite analcime (EMANA) was synthesized through the hydrothermal method by using carbothermal reduction electrolytic manganese residue (CR-EMR). The structural properties of EMANA and CR-EMR were studied using various characterization techniques. After hydrothermal synthesis, the CR-EMR became super-microporous, and the surface area increased by 4.76 times than before. Among the various synthesized zeolites, 6 h-synthesized EMANA was selected as the best adsorbent for macrolide antibiotics in aqueous solution. The adsorption performance of EMANA on the adsorption capacity was examined by using various experimental parameters, such as contact time (0⁻24 h), initial concentration (50⁻300 mg/L), temperature (30⁻50 °C) and pH (3⁻13). The experimental results were also analyzed by the Langmuir and Freundlich adsorption models, with the latter obtaining better representation. The adsorption process could be described well by the pseudo-second-order model, even under a low concentration (50 mg/L). This result suggests that the adsorption process of macrolide antibiotics is due to chemisorption. According to the Fourier Transform infrared spectroscopy (FT-IR) results, the adsorption of zeolite was mainly due to its hydroxyl group, which played an important role during the adsorption process. Moreover, EMANA is more suitable for treatment of roxithromycin (ROX) than azithromycin (AZM), because ROX has more adsorption sites for the hydroxyl group.

Brain cell apoptosis and enhancement of nervous excitability in pregnant rats with high plasma levels of homocysteine.

Hyperhomocysteinemia is an important risk factor for preeclampsia-eclampsia. This study established a pregnant rat model of hyperhomocysteinemia, in which blood plasma homocysteine concentrations were twice or three times greater than that of normal pregnant rats. TUNEL revealed an increase in the number of apoptotic cells in the frontal cortex of pregnant rats with hyperhomocysteinemia. In addition, immunohistochemical staining detected activated nuclear factor-κB-positve cells in the frontal cortex. Reverse transcription-PCR detected that mRNA expression of the anti-apoptotic gene bcl-2 diminished in the frontal cortex. In situ hybridization and western blotting revealed that N-methyl-D-aspartate receptor 1 mRNA and protein expression was upregulated in the frontal cortex and hippocampus. These results indicate that hyperhomocysteinemia can induce brain cell apoptosis, increase nerve excitability, and promote the occurrence of preeclampsia in pregnant rats.

[Change of plasma TH1/TH2 cytokines levels in patients with hemorrhagic fever with renal syndrome].

OBJECTIVE: To observe changes in T cell subsets and TH1/TH2 secreted cytokines in the plasma of patients with hemorrhagic fever with renal syndrome (HFRS). METHODS: Totally 22 patients with HFRS (9 mild cases and 13 moderate cases) were enrolled. Blood samples were taken 1, 4, and 12 weeks after presentation. T cell subsets were tested by flow cytometry (FCM), and the expression of cytokines in plasma were analysed with enzyme-linked immunosorbent assay (ELISA). Another 16 healthy blood donors were enrolled as the control group. RESULTS: CD3 + CD8 + T lymphocytes increased at week 1 and 4 (P < 0.01), which was more significant in mild cases than in moderate cases (P < 0.05). The change of CD3 + CD4 + T lymphocytes during the disease course were not significantly different from that in control group (P > 0.05). One week after presentation, TH1 [interleukin (IL)-2 and interferon-gamma (IFN-gamma)] and TH2 (IL-6, IL-10) cytokine productions were significantly higher in HFRS patients than in the control group (P < 0.01); IL-2 and IL-10 remained high levels during the whole observation period, and were still significantly higher than in the control group (P < 0.01). At week 4, the plasma IL-5 level was significantly higher in HFRS patients than in the control group (P < 0.01), and were still significantly higher than in the control group at week 12 (P < 0.01). At week 1 and 4, the plasma INF-gamma levels were significantly higher in moderate patients than in mild patients (P < 0.05); at week 12, the plasma IL-10 level was significantly higher in moderate patients than in mild patients(P < 0.05). CONCLUSIONS: CD3 + CD4 + T lymphocytes remarkably increases at the early stage of disease in patients with mild HFRS. The early cell mediated immune response is helpful for disease control. The cytokines INF-gamma and IL-10 increase more obviously in moderate patients, indicating that cytokines also are key pathogenic factors of HRFS.

[The dynamics of T lymphocyte subsets in hemorrhagic fever with renal syndrome].

OBJECTIVES: To investigate the T cell subsets changes in hemorrhagic fever with renal syndrome (HFRS) patients. METHODS: 22 HFRS patients who were diagnosed in Qin Huang Dao Third Hospital from April 2005 to July 2005 were enrolled in this study and divided into two groups according to clinical manifestations. T cell subsets of the 22 patients were monitored at week 1, 4 and 12. Another 56 subjects were enrolled as healthy controls. RESULTS: B cell count was normal during the 12 weeks in all the subjects. NK cell decreased significantly at week 1, and recovered at week 4 rapidly. CD(4)(+)T cell count was normal throughout the course of the disease, but the percentage of memory phenotype increased at week 1 and 4, reaching(64.1 +/- 17.5)% and (59.9 +/- 10.1)%, but recovered at week 12. CD(4)(+)CD(28)(+)T cells were normal throughout the entire study. CD(8)(+)T cell count increased dramatically at week 1 and 4, but finally recovered at week 12. The count of CD(8)(+)CD(28)(-)T cells increased significantly at week 1 in low-grade goup, but in median-grade group, this increase lagged to week 4 and was not as significant as in low-grade group. The percentage of CD(38)(+) or HLA-DR(+) subsets of CD(8)(+)T cell increased at week 1, 4. CONCLUSION: The results confirmed the relationship between HFRS progression and cellular immunity. It revealed that, at the early stage of HFRS, rapid and effective cytotoxicity T lymphocyte response may contribute to clear Hantavirus away and improve HFRS symptom.

[Change of plasma pro-inflammatory cytokines levels in patients with hemorrhagic fever with renal syndrome].

OBJECTIVE: To observe the changes of the plasma pro-inflammatory cytokines levels in patients with hemorrhagic fever with renal syndrome (HFRS). METHODS: Enzyme-linked immunosorbent assay (ELISA) was performed to detect the plasma pro-inflammatory cytokines levels of 22 HFRS patients (9 mild cases and 13 moderate cases) 1, 4, and 12 weeks after they were diagnosed. Sixteen healthy blood donors were recruited as control group. RESULTS: The levels of interleukin (IL)-1beta, IL-6, IL-10, tumor necrosis factor (TNF)-alpha, and IL-8 in HFRS patients were significantly higher than those in control group 1 week after they were diagnosed (all P < 0.01). The levels of IL-6 and TNF-alpha in HFRS patients returned to the normal levels four weeks after the diagnosis, while those of IL-1beta, IL-8, and IL-10 remained significantly higher than those in control group 12 weeks after the diagnosis (all P < 0.01). The IL-8 and IL-10 levels in mild HFRS patients were significantly higher than those in moderate HFRS patients at the same period (all P < 0.05). CONCLUSION: Abnormal expressions and secretion of pro-inflammatory cytokines occurs during the disease course of HFRS.

[Nosocomial fungal infections, analysis of 149 cases].

OBJECTIVE: To investigate the manifestation, diagnosis, antifungal therapy and outcome of nosocomial fungal infections. METHODS: The clinical data of 149 patients with nosocomial fungal infections admitted in the PUMC hospital from Dec. 1981 to Nov. 2001, 67 males and 82 females with an average age of 52.32 years, including the manifestation, diagnosis, treatment and outcome, were reviewed retrospectively. RESULTS: 134 out of the 149 patients suffered from deep mycoses. All cases had underlying conditions, including primary pulmonary diseases (n = 29), rheumatic disease (n = 20), hematological disease such as leukemia or lymphoma (n = 18), HIV infection/AIDS (n = 13), major surgery (n = 10), and intracerebral hemorrhage or cerebral infarction (n = 24). The predisposing factors or risk factors for deep mycoses included use of high dose broad-spectrum antibiotics over a long period (n = 37), steroids/cytotoxic chemotherapy (n = 29), immunosuppressant (n = 17), chemotherapy (n = 10), intravenous lines and incubation (n = 36), and tracheotomy or endotracheal intubation (n = 12). The infectious sites were lung, meninges, cerebral parenchyma, blood, etc. in the order of prevalence. Depending on infectious site and type of fungus, the clinical manifestations included fever (63.76%), respiratory symptom such as cough (37.58%), leucocytosis (39.6%), chest X-ray images (24.49%) etc. CNS fungal infection included meningitis, brain abscess, and granuloma. Meningitis due to Cryptococcus resembled that due to Mycobacterium tuberculosis. The main pathogenic fungal species were Candida albicans, C. tropicalis, C. parapsilosis, C. neoformans, and Aspergillus species. Amphotericin B, fluconazole, and flucytosine were used alone or in combination. The overall mortality rate was 29.53% (44/149). Out of the 149 patients 67 were cured, 29 made improvement. The incidence of fungal infection remarkably increased recently with 75 cases appearing in the past 5 years (50.34%). CONCLUSION: The incidence of fungal infection is increasing recently which is correlated with use of high dose broad-spectrum antibiotics over a long period, high dose steroids/cytotoxic chemotherapy, immunosuppressant, chemotherapy, and improvement of examination skills, etc. The main pathogens are still Candida albicans and non-albicans Candida species. Early diagnosis is very important.