Selecting a waste management option using a life-cycle analysis approach

Solid-waste management, and in particular the disposal of used packaging, is currently the subject of much topical debate. This is driven by both consumer and legislative pressures. Consumers see used packaging as a highly visible element of municipal solid waste, complaining of excessive packaging and low levels of recycling. Legislators, perhaps in pandering to the views expressed by consumer bodies, have been active within the CEC and individual Member States by introducing (or proposing) legislation or similar regulatory tools and targets to facilitate a greater diversion of used packaging from disposal by landfill to alternative solid-waste management practices, in particular recycling, which are widely accepted to have a lower impact on the environment. In this paper the relative environmental profiles of pursuing alternative solid-waste management practices to disposal by landfill are explored, focusing not just on solid waste per se but also on associated considerations of energy consumption and emissions, which are invariably overlooked as factors contributing to the environmental impact of solid-waste management practices.     

The Dud-Alternative Effect in Likelihood Judgment.

The judged likelihood of a focal outcome should generally decrease as the list of alternative possibilities increases. For example, the likelihood that a runner will win a race goes down when 2 new entries are added to the field. However, 6 experiments demonstrate that the presence of implausible alternatives (duds) often increases the judged likelihood of a focal outcome. This dud-alternative effect was detected for judgments involving uncertainty about trivia facts and stochastic events. Nonnumeric likelihood measures and betting measures reliably detected the effect, but numeric likelihood measures did not. Time pressure increased the magnitude of the effect. The results were consistent with a contrast-effect account: The inclusion of duds increases the perceived strength of the evidence for the focal outcome, thereby affecting its judged likelihood. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Distribution and Fate of Escherichia coli in Lake Michigan Following Contamination with Urban Stormwater and Combined Sewer Overflows

Escherichia coli distribution and persistence in nearshore Lake Michigan were assessed following heavy rains and sanitary sewer overflow (SSO) and combined sewer overflow (CSO) events over a 5-year period, including an 18-day period following 25.4 cm of rainfall in which intensive studies were conducted following multiple CSO and SSO events. E. coli levels in the Milwaukee estuary and harbor following SSO and CSO events ranged from 10⁴ to nearly 10⁵ CFU/100 mL, which were significantly higher (p ≤ 0.05) than levels following rainfall alone. Sites outside of the breakwall but within the contamination plume (e.g., within 2 km of the harbor) were an order of magnitude lower. Locations 2–5 km from the harbor ranged from below detection limits, of < 1 to 5 CFU/100 mL. E. coli levels corrected for dilution based on specific conductivity measurements were lower than what would be expected for loss due to dilution alone, suggesting a combination of die-off and dilution, were responsible for the rapid disappearance of these organisms outside of the harbor. E. coli and fecal coliforms measured concurrently demonstrated that fecal coliforms could be recovered longer than E. coli in the open waters of the lake. E. coli isolated directly from sewage treatment plant influent were found to have a marked increase in antibiotic resistance traits for ten antibiotics commonly used in the human population compared with isolates from two animal sources of fecal pollution. However, E. coli obtained from sewage impacted water (n = 2,513) and from stormwater impacted water (n = 1,465) collected the previous year when there were no sewage overflows, were found to have no significant difference (p < 0.05) in the frequency of resistance when comparing the two conditions. E. coli survival characteristics and population dynamics are most likely influenced by multiple factors in complex systems such as the watershed/estuarine/lake environments of the Great Lakes.     

(S)-Reutericyclin: Susceptibility Testing and In Vivo Effect on Murine Fecal Microbiome and Volatile Organic Compounds

We aimed to assess the in vitro antimicrobial activity and the in vivo effect on the murine fecal microbiome and volatile organic compound (VOC) profile of (S)-reutericyclin. The antimicrobial activity of (S)-reutericyclin was tested against Clostridium difficile, Listeria monocytogenes, Escherichia coli, Enterococcus faecium, Staphylococcus aureus, Staphylococcus (S.) epidermidis, Streptococcus agalactiae, Pseudomonas aeruginosa and Propionibacterium acnes. Reutericyclin or water were gavage fed to male BALBc mice for 7 weeks. Thereafter stool samples underwent 16S based microbiome analysis and VOC analysis by gas chromatography mass spectrometry (GC-MS). (S)-reutericyclin inhibited growth of S. epidermidis only. Oral (S)-reutericyclin treatment caused a trend towards reduced alpha diversity. Beta diversity was significantly influenced by reutericyclin. Linear discriminant analysis Effect Size (LEfSe) analysis showed an increase of Streptococcus and Muribaculum as well as a decrease of butyrate producing Ruminoclostridium, Roseburia and Eubacterium in the reutericyclin group. VOC analysis revealed significant increases of pentane and heptane and decreases of 2,3-butanedione and 2-heptanone in reutericyclin animals. The antimicrobial activity of (S)-reutericyclin differs from reports of (R)-reutericyclin with inhibitory effects on a multitude of Gram-positive bacteria reported in the literature. In vivo (S)-reutericyclin treatment led to a microbiome shift towards dysbiosis and distinct alterations of the fecal VOC profile.     

纳米TiO2在塑料中的抗菌性能研究

本文利用纳米TiO2作为无机抗菌填料，研制抗菌杀毒、表面自洁功能的塑料，其杀菌性能达到97％以上。探讨了纳米TiO2填料的杀菌性能影响因素及其杀菌广谱性。     

The replacement of animal testing: ethical issues and practical realities

Increasing expectation that products and materials of many kinds should be 'safe' is leading to demands for more toxicity testing. At the same time, there is mounting pressure to reduce, refine and replace laboratory animal experimentation. The testing of cosmetics is particularly controversial. The only way out of this dilemma is the development, validation, acceptance and use of non-animal test procedures, i.e. replacement alternative methods. Given realism and determination, more funding, better science and good strategic planning, the future for replacement alternatives, and thus for human and animal welfare, could be a very bright one.     

医院内抗生素耐药性传染的稳定性与Hopf分支

研究了医院内感染的带有非线性发生率的抗生素耐药性的时滞传染病模型的稳定性.确定了疾病暴发的阈值R0,运用Lasalle-Liapunov不变集原理和Routh-Hurwitz判据得到了,当R01时无病平衡点是全局稳定的;当R01时,地方病平衡点存在且唯一,对于任意的τ≠0,总能得到在地方病平衡点处的Hopf分支存在的条件.最后通过数值模拟验证了结论的正确性.     

One-Component Artificial Gustatory System Based on Hydrogen-Bond Organic Framework for Discrimination of Versatile Analytes

Hydrogen-bond organic frameworks (HOFs) with excellent structural and luminescent properties have emerged as a promising material for the construction of fluorescence sensors. However, designing a facile, universal and high throughput sensor with multiplex detection capacity still remains challenging. Herein, a one-component sensor array is constructed that mimics natural gustatory system for accurate and high-throughput discrimination and identification of versatile analytes. HOF as a single sensing element greatly simplifies the probe preparation in sensor array and detection procedure. Metal ions, proteins and bacteria as the model targets are rapid and accurately discriminated, presenting the universality of the system. Particularly, the system is successfully used for the classification of antibiotic mechanisms. The study expands the application scope of HOFs and provides a facile and universal system for sensing applications.     

Bacteria-Responsive Self-Assembly of Antimicrobial Peptide Nanonets for Trap-and-Kill of Antibiotic-Resistant Strains

Bacterial trapping using nanonets is a ubiquitous immune defense mechanism against infectious microbes. These nanonets can entrap microbial cells, effectively arresting their dissemination and rendering them more vulnerable to locally secreted microbicides. Inspired by this evolutionarily conserved anti-infective strategy, a series of 15 to 16 residue-long synthetic β-hairpin peptides is herein constructed with the ability to self-assemble into nanonets in response to the presence of bacteria, enabling spatiotemporal control over microbial killing. Using amyloid-specific K114 assay and confocal microscopy, the membrane components lipoteichoic acid and lipopolysaccharide are shown to play a major role in determining the amyloid-nucleating capacity as triggered by Gram-positive and Gram-negative bacteria respectively. These nanonets displayed both trapping and killing functionalities, hence offering a direct improvement from the trap-only biomimetics in literature. By substituting a single turn residue of the non-amyloidogenic BTT1 peptide, the nanonet-forming BTT1-3A analog is produced with comparable antimicrobial potency. With the same sequence manipulation approach, BTT2-4A analog modified from BTT2 peptide showed improved antimicrobial potency against colistin-resistant clinical isolates. The peptide nanonets also demonstrated robust stability against proteolytic degradation, and promising in vivo efficacy and biosafety profile. Overall, these bacteria-responsive peptide nanonets are promising clinical anti-infective alternatives for circumventing antibiotic resistance.     

DFT and TD-DFT theoretical studies on photo-induced electron transfer process on [Cefamandole].C60 nano-complex

The C₆₀ fullerene displays a considerable electronegativity. It has a unique photophysical and electrochemical behavior that can be used as a suitable drug carrier. In the present study, the interaction of C₆₀ fullerene as an electron recipient with the Cefamandole antibiotic was investigated in both ground and excited states using DFT and TD-DFT methods. The study of the interaction of C₆₀ and Cefamandole via electron localization function (ELF) and reduced density gradient (RDG) revealed that the complex formation is of van der Waals type. The data from natural bonding orbitals (NBO) analysis also confirmed the interaction type. The study of absorption and emission spectrum via CAM-B3LYP in the TD-SCF state showed that the emission peak of C₆₀ fullerene in the 591.73 nm after the complex formation results in the extinction of this emission spectrum due to charge transfer (CT) from chelator to fluorophore. The photoinduced electron transfer (PET) process was investigated using the electron hole theory.