Characterization and energy potential of food waste from catering service in Hangzhou, China.

Safe disposal of food waste is becoming an impending issue in China with the rapid increase of its production and the promotion of environmental awareness. Food waste from catering services in Hangzhou, China, was surveyed and characterized in this study. A questionnaire survey involving 632 units across the urban districts showed that 83.5% of the food waste was not properly treated. Daily food waste production from catering units was estimated to be 1184.5 tonnes. The ratio of volatile solid to total solid, easily biodegradable matter (including crude fat, crude protein and total starch) content in total solid and the ratio of total organic carbon to nitrogen varied in ranges of 90.1%-93.9%, 60.9%-72.1%, and 11.9-19.9, respectively. Based on the methane yield of 350 mL g VS(-1) in anaerobic batch tests, annual biogas energy of 1.0 × 10(9) MJ was estimated to be recovered from the food waste. Food waste from catering services was suggested to be an attractive clean energy source by anaerobic digestion.

Efficacy and safety of metformin in combination with chemotherapy in cancer patients without diabetes: systematic review and meta-analysis.

Background: The results of a meta-analysis of retrospective studies suggest that the use of metformin in cancer patients may prolong progression-free disease survival and overall survival. However, the studies included in the meta-analysis did not strictly distinguish between patients with or without type 2 diabetes mellitus. Therefore, further studies are needed to assess whether the use of adjuvant chemotherapy with metformin in cancer patients without diabetes improves prognosis. Method: Systematic searches of Embase, Pubmed, and The Cochrane library were performed for the subject terms metformin and neoplasm and for free words. Data related to PFS, OS were extracted according to inclusion exclusion criteria. The data were combined and meta-analysis was performed using Review Manager 5.4 to confirm the efficacy and safety of metformin administration. Results: There were 3228 publications retrieved from the database and a total of 13 publications with 955 patients were included in the meta-analysis after screening. All included studies were randomised controlled trials. Metformin combined with adjuvant chemotherapy did not improve progression-free survival (HR=1,95CI 0.79-1.25), overall survival (HR=0.91,95% CI 0.69-1.20) and did not improve objective disease response rates in patients. There was no significant difference in grade 3-4 adverse reactions compared to placebo. Conclusion: In this meta-analysis of randomised controlled trial studies, we found that chemotherapy in combination with metformin in cancer patients without diabetes did not prolong progression-free survival and overall survival and improved disease control in patients, although there was no significant difference in terms of safety. More high-quality randomised controlled trials are needed in the future to confirm the in vivo anti-tumour activity and survival benefit of metformin.

Improved lead removal from aqueous solution using novel porous bentonite - and calcite-biochar composite.

Biochar-mineral (bentonite/calcite) composite (BC-CM) prepared at different temperatures were tested under varied conditions for effective removal of lead (Pb) from aqueous solution. With increasing pyrolysis temperature, increased surface area, pore volume, bentonite decomposition and less or no decomposition of calcite occurred. Bentonite-biochar (BCS) and calcite-biochar (CCS) prepared at 700 °C were found most suitable for efficient removal of Pb (99.9%). Bentonite and calcite acted as catalyst and contributed to changes in yield, pH, texture, functional groups, minerals and carbonization that facilitated efficient Pb removal by BCS 700 and CCS 700. Pb concentration, pH, dose of BCS and CCS, and contact time were further optimized using response surface methodology (RSM) for maximizing removal percentage (R%) of Pb and adsorption capacity (qt). Both BCS 700 and CCS 700 showed similar effects (positive/negative) of factors on R% and qt. Under optimized conditions, 0.21 g of BCS 700 effectively removed 99.2% of 431 mg/L in 3.6 h at solution pH of 4.2, while 0.07 g CCS 700 removed 97.06% of 232 mg/L in 3.5 h at 5.5 pH. Removal of Pb onto both BCS and CCS was by monolayer adsorption with maximum adsorption capacity of 500 mg/g. Rapid Pb removal was observed within 2 h of contact time (CCS 700 > BCS 700) and equilibrium was achieved within 10 h. BCS 700 followed first order and CCS 700 followed second order kinetic model. Electrostatic attraction between Pb ions and mineral groups present in BCS 700 and CCS 700 also played important role in Pb removal. This study clearly demonstrated that composite of biochar with bentonite or calcite under optimized conditions significantly improved Pb removal and adsorption capacity that can be further utilized for larger scale applications.

Use of 13C labeling to assess carbon partitioning in transgenic and nontransgenic (parental) rice and their rhizosphere soil microbial communities.

Photosynthetic assimilation of CO2 is a primary source of carbon in soil and root exudates and can influence the community dynamics of rhizosphere organisms. Thus, if carbon partitioning is affected in transgenic crops, rhizosphere microbial communities may also be affected. In this study, the temporal effects of gene transformation on carbon partitioning in rice and rhizosphere microbial communities were investigated under greenhouse conditions using the 13C pulse-chase labeling method and phospholipid fatty acid (PLFA) analysis. The 13C contents in leaves of transgenic (Bt) and nontransgenic (Ck) rice were significantly different at the seedling, booting and heading stages. There were no detectable differences in 13C distribution in rice roots and rhizosphere microorganisms at any point during rice development. Although a significantly lower amount of Gram-positive bacterial PLFAs and a higher amount of Gram-negative bacterial PLFAs were observed in Bt rice rhizosphere as compared with Ck at all plant development stages, there were no significant differences in the amount of individual 13C-PLFA between Bt and Ck rhizospheres at any growing stage. These findings indicate that the insertion of cry1Ab and marker genes into rice had no persistent or adverse effect on the photosynthate distribution in rice or the microbial community composition in its rhizosphere.

Simultaneous removal of Sb(iii) and Cd(ii) in water by adsorption onto a MnFe2O4-biochar nanocomposite.

In this study, a jacobsite-biochar nanocomposite (MnFe2O4-BC) was fabricated and used to simultaneously remove Sb(iii) and Cd(ii) from water via adsorption. The MnFe2O4-BC nanocomposite was prepared via a co-precipitation method and analyzed using various techniques. The results confirm the successful decoration of the biochar surface with MnFe2O4 nanoparticles. The maximum Sb(iii) removal efficiency was found to be higher from bi-solute solutions containing Cd(ii) than from single-solute systems, suggesting that the presence of Cd(ii) enhances the removal of Sb(iii). The Langmuir isotherm model describes well Sb(iii) and Cd(ii) removal via adsorption onto the MnFe2O4-BC nanocomposite. The maximum adsorption capacities are 237.53 and 181.49 mg g-1 for Sb(iii) and Cd(ii), respectively, in a bi-solute system. Thus, the prepared MnFe2O4-BC nanocomposite is demonstrated to be a potential adsorbent for simultaneously removing Sb(iii) and Cd(ii) ions from aqueous solutions.

[Effects of biochar application on greenhouse gas emission from paddy soil and its physical and chemical properties].

A field experiment was conducted to investigate the effects of rice straw returning and rice straw biochar and life rubbish biochar application on the greenhouse gas (CH4, CO2 and N2O) emission from paddy soil, its physical and chemical properties, and rice grain yield. Compared with rice straw returning, applying rice straw biochar decreased the cumulative CH4 and N2O emissions from paddy soil significantly by 64.2% - 78.5% and 16.3% - 18.4%, respectively. Whether planting rice or not, the cumulative N2O emission from paddy soil under the applications of rice straw biochar and life rubbish biochar was decreased significantly, compared with that without biochar amendment. Under the condition of no rice planting, applying life rubbish biochar reduced the cumulative CO2 emission significantly by 25.3%. Rice straw biochar was superior to life rubbish biochar in improving soil pH and available potassium content. Both rice straw biochar and life rubbish biochar could increase the soil organic carbon content significantly, but had less effects on the soil bulk density, total nitrogen and available phosphorus contents, cation exchange capacity (CEC), and grain yield. It was suggested that compared with rice straw returning, straw biochar was more effective in improving rice grain yield.

Precision of coaxial needle placement in computed tomography-guided transthoracic needle biopsy.

In the present study, a set of self-designed measurement protocols for the precision of coaxial needle placement (PCNP) was proposed and applied in a computed tomography (CT)-guided transthoracic needle biopsy (TNB) audit of an interventional radiologist to determine if the PCNP was commensurate with the experience of the operator. A total of 102 patients (98 with lung lesions and four with mediastinum lesions) consented to be subjected to CT-guided TNB performed by staff interventional radiologists. The patients were divided into two groups based on appointment date. Group A consisted of the first 51 patients and group B comprised of the latter 51 patients. A set of self-designed measurement protocols for PCNP was proposed, and the PCNP was classified into four grades, from grade 1 (most accurate) to grade 4 (least accurate). PCNPs were independently measured by three staff radiologists who were blind to the grouping. The anatomical features of the lesions were also analyzed between the two groups. A significant difference in the PCNP gained after the first needle placement was identified between the two groups (P=0.003, two-tailed). The number of patients in group B with grade I PCNP (51.0%) was significantly higher than that in group A (21.6%) (P<0.05). The number of patients in group B with grade III PCNP (11.8%) was significantly lower than that in group A (29.4%, P<0.05). The PCNP was observed to be commensurate with the experience of the operator and should be considered as a routine audit index in CT-guided TNB.

[Mechanisms of nitrous oxide emission during livestock manure aerobic composting].

Aerobic composting is an effective way to treat and recycle livestock manure. However, the aerobic composting of livestock manure is a potential source of the greenhouse gas nitrous oxide (N2O), which closely relates to the global greenhouse effect and ozone depletion. With the expansion of livestock industry and the dramatic increasing yield of manure compost, the N2O emission during the aerobic composting has become a severe problem. The researches on the mechanisms of N2O emission during livestock manure composting have attracted increasing concerns. In this paper, the recent researches on the N2O generation approaches, emission dynamics, potential affecting factors, and microbiological mechanisms of N2O emission during livestock manure aerobic composting were reviewed, and the measures to control the N2O emission during composting process were summarized. Some perspectives for the future researches in this field were suggested.

[Research advances in control of N2O emission from municipal solid waste landfill sites].

Landfill is one of the main approaches for municipal solid waste treatment, and landfill site is a main emission source of greenhouse gases nitrous oxide (N2O) and methane (CH4). As a high-efficient trace greenhouse gas, N2O has a very high warming potential, with a warming capacity 296 times of CO2, and has a long-term stability in atmosphere, giving greater damage to the ozone layer. Aiming at the researches in the control of N2O emission from municipal solid waste landfill sites, this paper summarized the characteristics and related affecting factors of the N2O emission from the landfill sites, and put forward a series of the measures adaptable to the N2O emission control of present municipal solid waste landfill sites in China. Some further research focuses on the control of N2O emission from the landfill sites were also presented.

[Application of stable carbon isotope technique in the research of carbon cycling in soil-plant system].

As a main life element, carbon plays important role in the matter cycling in soil-plant system. Stable carbon isotope 13C has been widely used in the study of carbon cycling in soil-plant system, due to its safe, no pollution, and easy to be handled. Through the analysis of both natural and labeled 13C organic matter in soil-plant system, a better understanding of the mechanisms of photosynthesis, the distribution of photosynthates in plant-soil system, the fate of plant litter, and the source of new carbon in soil could be achieved. In this paper, the applications of stable carbon isotope technique in the researches of photosynthesis, reconstruction of paleoclimate, turnover of soil organic matter, and interactions between plants and rhizosphere microorganisms were briefly summarized, and the perspectives of the application of stable carbon isotope technique were also discussed, based on the issues existed in current researches.