Impacts of irrigation with treated livestock wastewater on the accumulation characteristic of ARGs in the farmland soil: a case study in Hohhot, China.

Irrigation with treated livestock wastewater (TWW) is a promising strategy for reusing resources. However, TWW irrigation might introduce antibiotic resistant genes (ARGs) into the soil, posing environmental risks associated with antibiotic resistance. This study focuses on investigating the influence of irrigation amounts and duration on the fate of ARGs and identifies key factors driving their changes. The results showed that there were 13 ARGs in TWW, while only 5 ARGs were detected in irrigated soil. That is some introduced ARGs from TWW could not persistently exist in the soil. After 1-year irrigation, an increase in irrigation amount from 0.016 t/m2 to 0.048 t/m2 significantly enhanced the abundance of tetC by 29.81%, while ermB and sul2 decreased by 45.37% and 76.47%, respectively (p < 0.01). After 2-year irrigation, the abundance of tetC, ermB, ermF, dfrA1, and total ARGs significantly increased (p < 0.05) when the irrigation amount increased. The abundances of ARGs after 2-year irrigation were found to be 2.5-34.4 times higher than 1 year. Obviously, the irrigation years intensified the positive correlation between ARGs abundance and irrigation amount. TetC and ermF were the dominant genes resulting in the accumulation of ARGs. TWW irrigation increased the content of organic matter and total nitrogen in the soil, which affected microbial community structure. The changes of the potential host were the determining factors driving the ARGs abundance. Our study demonstrated that continuous TWW irrigation for 2 years led to a substantial accumulation of ARGs in soil.

Clinical application of diffusion-weighted magnetic resonance imaging in radiotherapy for nasopharyngeal carcinoma.

OBJECTIVE: To explore the clinical application of diffusion-weighted magnetic resonance imaging (DWI) in nasopharyngeal carcinoma (NPC) diagnosis, detection of lymph node metastasis, radiotherapy and prognosis. METHODS: Twenty patients with diagnosed NPC in an early stage of radiotherapy were enrolled in our department between May 2010 and May 2013. T1 and T2 weighted magnetic resonance imaging and DWI of the nasopharynx and neck were performed 1 week before radiotherapy, during radiotherapy at a dose of 60 Gy, and 1 month after radiotherapy. Pertinent measurements and related data were recorded. RESULTS: In comparison with that before radiotherapy, the ADC value of the nasopharyngeal primary lesion increased significantly during radiotherapy at a dose of 60 Gy and at 1 month after radiotherapy (F = 187.160, P = 0.000). When the dose of radiotherapy reached 60 Gy, the DWI signals from both the neck and the retropharyngeal lymph nodes were significantly lower than those before radiotherapy. CONCLUSION: DWI can be used for sensitive and accurate diagnosis of lymph node metastasis in the neck and retropharyngeal space, monitoring of the radiotherapy effect in early stages of NPC and development of new medical treatment strategies.

A hanging plasmonic droplet: three-dimensional SERS hotspots for a highly sensitive multiplex detection of amino acids.

A novel and simple platform for an efficient SERS detection was demonstrated in a hanging plasmonic droplet of Ag sols by virtue of three-dimensional (3D) SERS hotspots. The platform was a single droplet of concentrated Ag sols with analytes hung on a hydrophobically treated transparent cover glass. Liquid adhesive force, solvent evaporation, and hydrophobic interaction induced a concentration of dense nanoparticles into a 3D space. The generated 3D hotspots enable the highly-sensitive detection of ultratrace analytes and simultaneous multiplex identification of different amino acids, which are well-known molecules with low Raman cross-sections. This platform demonstrates an excellent mechanical stability and is suitable for the excellent examination of ultratrace analytes, with detection limits as low as 0.01 fmol of dye molecules and 5 pmol of amino acids with extremely low Raman cross-sections.

Value of diffusion-weighted magnetic resonance imaging on the follow-up of nasopharyngeal carcinoma after radiotherapy.

PURPOSE: To explore the value of diffusion-weighted imaging (DWI) and magnetic resonance imaging (MRI) on the follow-up of nasopharyngeal carcinoma (NPC) after radiotherapy. MATERIAL AND METHODS: Eighty-three NPC patients after radiotherapy were divided into two groups: 4 cases of residual tumor and 33 cases of non-residual within 6 months, the cases of recurrent and non-recurrent were 5 and 41 over 6 months, respectively. MRI and DWI imaging of these cases were closely analyzed, and the apparent diffusion coefficient (ADC) of the nasopharyngeal residual mass and nasopharyngeal wall thickening, skull base destruction and lateral pterygoid muscle were measured. RESULTS: The ADC of the lateral pterygoid muscle was (1.501 ± 0.069) × 10^{ - 3} mm^{2}/s in 83 cases. The ADCs of the non-residual group, residual group, non-recurrent group and recurrent group were (1.843 ± 0.133.4) × 10^{ - 3} mm^{2}/s, (1.097 ± 0.183) × 10^{ - 3} mm^{2}/s, (1.884 ± 0.134) × 10^{ - 3} mm^{2}/s and (0.787 ± 0.067) × 10^{ - 3} mm^{2}/s respectively.The ADCs of the residual group and recurrent group were lower than that of the lateral pterygoid muscle, while the ADCs of the non-residual group and non-recurrent group were higher than that of the lateral pterygoid muscle.The differences were statistically significant (P < 0.05). CONCLUSION: DWI can provide qualitative and quantitative information about the tumor cellular level; it can also identify residual, local fibrosis and recurrence after NPC radiotherapy sensitively and accurately by measuring the ADC of the region of interest.

Effects of lakeshore landcover types and environmental factors on microplastic distribution in lakes on the Inner Mongolia Plateau, China.

Microplastic pollution in freshwater environments has received increasing attention. However, limited research on the occurrence and distribution of microplastics in plateau lakes. This study investigated the microplastic characteristics and influencing factors in lakes with different land cover types on the Inner Mongolia Plateau. Results showed that microplastic abundance ranged from 0.5 to 12.6 items/L in water and 50-325 items/kg in sediments. Microplastics in water were predominantly polypropylene (50.5%), fragments (40.5%), and 50-200 µm (66.7%). High-density (27.9%), fibrous (69.3%), and large-sized microplastics (47.7%) were retained primarily in lake sediments. The highest microplastic abundance in water was found in cropland lakes and grassland lakes, while that in sediments was in descending order of desert lakes > cropland lakes > grassland lakes > forest-grassland lakes. Differences among lake types suggest that agriculture, tourism, and atmospheric transport may be critical microplastic sources. Microplastic distribution was positively correlated with farmland and artificial surface coverage, showing that land cover types related to human activities could exacerbate microplastic pollution in lakes. Redundancy analysis showed that ammonia nitrogen and pH were the key physicochemical factors affecting microplastic distribution in lakes, indicating the potential sources of microplastics in lakes and the uniqueness of microplastic occurrence characteristics in desert saline-alkaline lakes, respectively.

Leveraging machine learning for prediction of antibiotic resistance genes post thermal hydrolysis-anaerobic digestion in dairy waste.

Anaerobic digestion holds promise as a method for removing antibiotic resistance genes (ARGs) from dairy waste. However, accurately predicting the efficiency of ARG removal remains a challenge. This study introduces a novel appproach utilizing machine learning to forecast changes in ARG abundances following thermal hydrolysis-anaerobic digestion (TH-AD) treatment. Through network analysis and redundancy analyses, key determinants of affect ARG fluctuations were identified, facilitating the development of machine learning models capable of accurately predicting ARG changes during TH-AD processes. The decision tree model demonstrated impressive predictive power, achieving an impessive R2 value of 87% against validation data. Feature analysis revealed that the genes intI2 and intI1 had a critical impact on the absolute abundance of ARGs. The predictive model developed in this study offers valuable insights for improving operational and managerial practices in dairy waste treatment facilities, with the ultimate goal of mitigating the spread of antibiotic resistance.

Isolation and characterization of Shigella flexneri G3, capable of effective cellulosic saccharification under mesophilic conditions.

A novel Shigella strain (Shigella flexneri G3) showing high cellulolytic activity under mesophilic, anaerobic conditions was isolated and characterized. The bacterium is Gram negative, short rod shaped, and nonmotile and displays effective production of glucose, cellobiose, and other oligosaccharides from cellulose (Avicel PH-101) under optimal conditions (40°C and pH 6.5). Approximately 75% of the cellulose was hydrolyzed in modified ATCC 1191 medium containing 0.3% cellulose, and the oligosaccharide production yield and specific production rate reached 375 mg g Avicel(-1) and 6.25 mg g Avicel(-1) h(-1), respectively, after a 60-hour incubation. To our knowledge, this represents the highest oligosaccharide yield and specific rate from cellulose for mesophilic bacterial monocultures reported so far. The results demonstrate that S. flexneri G3 is capable of rapid conversion of cellulose to oligosaccharides, with potential biofuel applications under mesophilic conditions.

Performance of full-scale aerobic composting and anaerobic digestion on the changes of antibiotic resistance genes in dairy manure.

Understanding the different performances of full-scale active composting (AC) and anaerobic digestion (AD) on the changes of antibiotic resistance genes (ARGs) in dairy manure is crucial to uncover the dissemination risks of ARGs in post-biotreated manure. In this regard, metagenomic sequencing was deployed to reveal the variations of ARGs in dairy manure in an intensive dairy farm. Results showed that the total abundance of ARGs increased from 150.64 reads/ng DNA to 204.06 reads/ng DNA in dairy manure, and it is mainly attributed to the contributions of AC (85.49%) rather than AD (14.51%). In AC, more ARG subtypes were induced and the dominant ARG subtypes were shifted completely, probably due to the enrichment of Proteobacteria and Actinobacteria which could be the hosts of multiple ARGs. These results inspire us to further evaluate the dissemination risks of ARGs along the route from composted manure to soil and to plants.

Changes and distributions of antibiotic resistance genes in liquid and solid fractions in mesophilic and thermophilic anaerobic digestion of dairy manure.

This study mainly explored the changes and distributions of antibiotic resistance genes (ARGs) in liquid fraction (LF) and solid fraction (SF) in anaerobic digestion (AD) of dairy manure. After mesophilic and thermophilic AD, the copy numbers of ARGs in LF decreased by 0.06-1.80 logs while those in SF increased by 0.08-7.85 logs, suggesting the enrichment of ARGs in SF. Statistical analysis elucidated that high total solids promoted the enrichment of ARGs in SF. The increased abundances of genera such as Ruminofilibacter, Treponema and Sphaerochaeta in SF were responsible for the enrichment of most ARGs. These insights demonstrated the digested solid had the potential risks to promote the spread of ARGs in the environment, and the digested solid of livestock manure should be post-treated before the application.

[Effects of Temperature and Stirring on the Changes of Antibiotic Resistance Genes and Microbial Communities in Anaerobic Digestion of Dairy Manure].

To investigate the effects of temperature and stirring on antibiotic resistance genes (ARGs) and microbial communities during the anaerobic digestion of dairy manure, mesophilic and thermophilic anaerobic digestion experiments were performed with and without stirring. Two-way analysis of variance indicated that temperature affected biogas production more strongly than stirring (η2=0.934>0.911), and thermophilic and stirring increased the total biogas yield by 13.93% and 12.63%, respectively. The effect of temperature on the removal of ARGs was also stronger than that of stirring (η2=0.992>0.920), where thermophilic conditions enhanced the reduction of ARGs and MGEs to 0.09-1.53 (logarithm), while stirring had no significant effects. When temperature was altered from mesophilic to thermophilic, the microbial communities shifted, with Firmicutes becoming the dominant phylum after thermophilic anaerobic digestion, with a relative abundance of >86%. Network analysis demonstrated that eight genera including Sedimentibacter, Sphaerochaeta, and Pseudomonas were the hosts of ARGs and MGEs, and the redundancy analysis suggested that physicochemical parameters play important roles in shaping microbial communities, especially TAN and TVFAs, which indirectly affected the ARGs by altering their host bacteria.

Emerging Strategies for Modifying Lignin Chemistry to Enhance Biological Lignin Valorization.

Biological lignin valorization represents a promising approach contributing to sustainable and economic biorefineries. The low level of valuable lignin-derived products remains a major challenge hindering the implementation of microbial lignin conversion. Lignin's properties play a significant role in determining the efficiency of lignin bioconversion. To date, despite significant progress in the development of biomass pretreatment, lignin fractionation, and fermentation over the last few decades, little efforts have gone into identifying the ideal lignin substrates for an efficient microbial metabolism. In this Minireview, emerging and state-of-the-art strategies for biomass pretreatment and lignin fractionation are summarized to elaborate their roles in modifying lignin structure for bioconversion. Fermentation strategies aimed at enhancing lignin depolymerization for microbial utilization are systematically reviewed as well. With an improved understanding of the ideal lignin structure elucidated by comprehensive metabolic pathways and/or big data analysis, modifying lignin chemistry could be more directional and effective. Ultimately, together with the progress of fermentation process optimization, biological lignin valorization will become more competitive in biorefineries.

Bio-hydrogen production from cellulose by sequential co-culture of cellulosic hydrogen bacteria of Enterococcus gallinarum G1 and Ethanoigenens harbinense B49.

Microbial conversion of lignocellulose to hydrogen is a fascinating way to provide a renewable energy source. A mesophilic bacterium strain G1 that had high cellulose degradation and hydrogen production activity (2.38 mmol H(2) g(-1) cellulose) was isolated from rumen fluid and identified as the Enterococcus gallinarum. Hydrogen production from cellulose by using sequential co-cultures of a cellulosic-hydrolysis bacterium G1 and Ethanoigenens harbinense B49 was investigated. With an initial Avicel concentration of 5 g l(-l), the sequential co-culture with G1 and strain Ethanoigenens harbinense B49 produced H(2) yield approximately 2.97 mmol H(2) g(-1) cellulose for the co-culture system.

Role of feline sarcoma­related protein in the viability and apoptosis of bladder cancer cells.

Feline sarcoma­related protein (Fer) is a type of nuclear and cytoplasmic non­receptor protein tyrosine kinase, which is associated with the progression of numerous types of cancer. Previously, we identified that Fer is associated with the migration and invasion of bladder cancer. The present study aimed to investigate the role of Fer in bladder cancer cell viability and apoptosis. Reverse transcription­quantitative polymerase chain reaction and western blot analysis were performed to detect the expression levels of Fer; short interference RNA (siRNA) and overexpression vectors were used to downregulate or upregulate Fer expression, respectively. The effects on cell proliferation ability and cell apoptosis were then tested by MTT assay and flow cytometry. The results revealed that Fer expression was upregulated in bladder cancer cell lines. Downregulation of Fer expression by siRNA significantly suppressed T24 cell viability and induced apoptosis, as well as inducing cell cycle arrest. Conversely, Fer overexpression in 5637 cells significantly promoted cell viability and cell cycle progression, but inhibited cell apoptosis. Furthermore, the suppression and overexpression of Fer significantly altered the expression of cleaved caspase­3 and Bcl­2, and dysregulated the P38 mitogen­activated protein kinase signaling pathway. The findings of the present study indicate a possible molecular mechanism of Fer in bladder cancer and may be considered as a potential target in the treatment of this disease.

AIB1 predicts tumor response to definitive chemoradiotherapy and prognosis in cervical squamous cell carcinoma.

Amplified in breast cancer 1 (AIB1) gene, has been reported to be associated with biological malignancy in several cancers. However, the molecular status of the AIB1 gene in cervical cancer and the clinicopathological/prognostic significance of AIB1 expression in chemoradiotherapy (CRT) sensitivity have not been determined. In our present study, we found that the high expression of AIB1 was frequent detected in specimens of cervical cancer patients, and this was significantly correlated with CRT response (P = 0.014), clinical stage (P = 0.003), T status (P = 0.027), N status (P = 0.021), M status (P = 0.015) and progression-free survival (P < 0.001). Moreover, the clonogenic survival fraction and cell apoptosis experiments showed that knockdown of AIB1 substantially increased cervical cancer cells sensitivity to ionizing radiation (IR) or cisplatin/5-fluorouracil. Collectively, our results demonstrated that the high expression of AIB1 in cervical cancer cells contributes to the resistance to CRT, which provides the evidence that AIB1 may be a promising predictor of aggressive cervical cancer patients with poor response to CRT.

Analysis of enzymolysis process kinetics and estimation of the resource conversion efficiency to corn cobs with alkali soaking, water and acid steam explosion pretreatments.

This short communication analyzed enzymolysis kinetics and estimated the resource conversion efficiency of corn cobs. Three pretreatments were applied, and enzymatic hydrolysis was performed to obtain solid residues. The enzymolysis process was fit to a modified logistic formula. The kinetics of enzymolysis were similar for all pretreatments, and all kinetics fit the modified logistic formula. Resource conversion efficiency and saccharification efficiency were estimated for the following pretreatments: 69% and 86% for acid steam explosion, 59% and 73% for alkali soaking, 41% and 51% for water steam explosion, respectively. It can be concluded that pretreatment has a minor effect on the enzymolysis process of corn cobs and a greater effect on saccharification efficiency or resource conversion efficiency.

The Association Between MGMT Promoter Methylation and Patients with Gastric Cancer: A Meta-Analysis.

AIMS: Several previous studies have suggested that MGMT promoter methylation is significantly associated with gastric cancer, but the results were not consistent. Hence, we conducted a systematic meta-analysis to explore the potential correlation of MGMT promoter methylation with gastric cancer and its clinicopathologic characteristics. MATERIALS AND METHODS: Searches of PubMed, EMBASE, Web of Science, Cochrane Library, and Chinese National Knowledge Infrastructure (CNKI) literature databases were conducted to identify relevant studies published in English or Chinese before July 1, 2016. The meta-analysis was performed using Stata 12.0 software. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to assess the association between MGMT promoter methylation and gastric cancer. We also conducted a subgroup analysis and metaregression to explore sources of heterogeneity. RESULTS: We identified 12 articles that met the inclusion criteria. The 12 articles described 14 studies that included 1571 tumor tissues and 1243 controls. The meta-analysis results demonstrated that the frequency of MGMT promoter methylation was higher in gastric cancer tissues compared with adjacent tissues and normal tissues (OR = 4.06, 95% CI: 2.55-6.46, p < 0.001; OR = 8.85, 95% CI: 1.15-68.23, p = 0.036; respectively). An assessment of the correlation between MGMT promoter methylation and clinicopathological characteristics indicated that MGMT promoter hypermethylation was significantly associated with tumor-node-metastasis stage, lymph node metastasis, and distant metastasis (OR = 2.11, 95% CI: 1.18-3.75, p = 0.011; OR = 1.99, 95% CI: 1.47-2.68, p < 0.001; and OR = 3.60, 95% CI: 2.17-5.95, p < 0.001; respectively). CONCLUSION: Our findings provide evidence that MGMT promoter methylation could play an important role in gastric carcinogenesis and may serve as an important biomarker for gastric cancer progression.

Buffering action of acetate on hydrogen production by Ethanoligenens harbinense B49

The buffering effect of acetate on hydrogen production during glucose fermentation by Ethanoligenens harbinense B49 was investigated compared to phosphate, a widely used fermentative hydrogen production buffer. Specific concentrations of sodium acetate or phosphate were added to batch cultures, and the effects on hydrogen production were comparatively analyzed using a modified Gompertz model. Adding 50 mM acetate or phosphate suppressed the hydrogen production peak and slightly extended the lag phase. However, the overall hydrogen yields were 113.5 and 108.5 mmol/L, respectively, and the final pH was effectively controlled. Acetate buffered against hydrogen production more effectively than did phosphate, promoting cell growth and preventing decreased pH. At buffer concentrations 100-250 mM, the maximum hydrogen production was barely suppressed, and the lag phase extended past 7 h. Therefore, although acetate inhibits hydrogen production, using acetate as a buffer (like phosphate) effectively prevented pH drops and increased substrate consumption, enhancing hydrogen production.

[Effect of initial substrate concentrations and pH on hydrogen production from xylose with Clostridium butyricum T4].

We studied the effect of initial pH and substrate concentrations on the conversion of xylose to hydrogen by Clostridium butyrium T4 at pH 5.0-8.5 and substrate concentrations 5-40 g/L. The cumulative hydrogen volume and the specific hydrogen production rate increased and then decreased with increasing initial pH or substrate concentrations. At initial pH 6.5 and substrate concentration 20 g/L, the cumulative hydrogen production and the specific hydrogen production rate reached the maximum value of 4.26 L/L and 18.86 mmol-H2/h g-DCW (dry cell weight).

Bioconversion of lignocellulosic biomass to hydrogen: Potential and challenges.

No comprehensive review on the bioconversion of lignocellulosic biomass to hydrogen is presented. This paper provides an up-to-date review on recent research development in biotechnology-based lignocellulosic biomass-to-H(2) conversion. Bioconversion of lignocellulosic prehydrolysate, hydrolysate or cellulose to hydrogen was discussed in terms of the involved microorganisms and the bioaugmentation tactics. To achieve fully the utilization of biomass, the integrated approaches composed of coupled dark-photo fermentation and the dark fermentation and bioelectrohydrogenesis were sketched. Additionally, this review sheds light on the perspectives on the lignocellulosic biomass conversion to hydrogen, and on the scientific and technical challenges faced for the lignocelluloses bioconversion.

Hydrogen production by immobilized R. faecalis RLD-53 using soluble metabolites from ethanol fermentation bacteria E. harbinense B49.

In order to increase the hydrogen yield from glucose, hydrogen production by immobilized Rhodopseudomonas faecalis RLD-53 using soluble metabolites from ethanol fermentation bacteria Ethanoligenens harbinense B49 was investigated. The soluble metabolites from dark-fermentation mainly were ethanol and acetate, which could be further utilized for photo-hydrogen production. Hydrogen production by B49 was noticeably affected by the glucose and phosphate buffer concentration. The maximum hydrogen yield (1.83 mol H(2)/mol glucose) was obtained at 9 g/l glucose. In addition, we found that the ratio of acetate/ethanol (A/E) increased with increasing phosphate buffer concentration, which is favorable to further photo-hydrogen production. The total hydrogen yield during dark- and photo-fermentation reached its maximum value (6.32 mol H(2)/mol glucose) using 9 g/l glucose, 30 mmol/l phosphate buffers and immobilized R. faecalis RLD-53. Results demonstrated that the combination of dark- and photo- fermentation was an effective and efficient process to improve hydrogen yield from a single substrate.