Anaerobic Degradability of Commercially Available Bio-Based and Oxo-Degradable Packaging Materials in the Context of Their End of Life in the Waste Management Strategy

There are discrepancies concerning the time frame for biodegradation of different commercially available foils labeled as biodegradable; thus, it is essential to provide information about their biodegradability in the context of their end of life in waste management. Therefore, one-year mesophilic (37 °C) anaerobic degradation tests of two bio-based foils (based on starch (FS), polylactic acid (FPLA)) and oxo-degradable material (FOXO) were conducted in an OxiTop system. Biodegradation was investigated by measuring biogas production (BP) and analyzing structural changes with differential scanning calorimetry, polarizing and digital microscopic analyses, and Fourier transform infrared spectroscopy. After 1 year, FOXO had not degraded; thus, there were no visible changes on its surface and no BP. The bio-based materials produced small amounts of biogas (25.2, FPLA, and 30.4 L/kg VS, FS), constituting 2.1–2.5% of theoretical methane potential. The foil pieces were still visible and only starting to show damage; some pores had appeared in their structure. The structure of FPLA became more heterogeneous due to water diffusing into the structure. In contrast, the structure of FS became more homogenous although individual cracks and fissures appeared. The color of FS had changed, indicating that it was beginning to biodegrade. The fact that FS and FPLA showed only minor structural damage after a one-year mesophilic degradation indicates that, in these conditions, these materials would persist for an unknown but long amount of time.

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Evaluation of single-electron movies of glutamine synthetase molecules

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100075191 ◽

1983 ◽

Vol 41 ◽

pp. 280-281

Author(s):

W. Kunath ◽

E. Zeitler ◽

M. Kessel

Keyword(s):

Electron Microscope ◽

Glutamine Synthetase ◽

Electron Irradiation ◽

Structural Damage ◽

Structural Changes ◽

Single Electron ◽

Continuous Series ◽

Digital Recording ◽

Recording Device ◽

Low Exposure

The features of digital recording of a continuous series (movie) of singleelectron TV frames are reported. The technique is used to investigate structural changes in negatively stained glutamine synthetase molecules (GS) during electron irradiation and, as an ultimate goal, to look for the molecules' “undamaged” structure, say, after a 1 e/Å2 dose.The TV frame of fig. la shows an image of 5 glutamine synthetase molecules exposed to 1/150 e/Å2. Every single electron is recorded as a unit signal in a 256 ×256 field. The extremely low exposure of a single TV frame as dictated by the single-electron recording device including the electron microscope requires accumulation of 150 TV frames into one frame (fig. lb) thus achieving a reasonable compromise between the conflicting aspects of exposure time per frame of 3 sec. vs. object drift of less than 1 Å, and exposure per frame of 1 e/Å2 vs. rate of structural damage.

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Development and Structural Changes of Carbon Footprint in EU28

Sustainability ◽

10.3390/su13094771 ◽

2021 ◽

Vol 13 (9) ◽

pp. 4771

Author(s):

Josef Slaboch ◽

Pavlína Hálová ◽

Adriana Laputková

Keyword(s):

Cluster Analysis ◽

Waste Management ◽

Carbon Footprint ◽

Structural Changes ◽

Energy Industry ◽

The European Union ◽

Topical Issue ◽

Economic Sectors ◽

Index Analysis ◽

Per Capita

This paper discusses the topical issue which examines the development of CO2 emissions in individual countries of the European Union (EU28) for the period between 2000 and 2017. Carbon footprint is monitored in four basic economic sectors of the EU28 countries—energy, other industries, agriculture, and waste management. The purpose of this paper is to conduct a structural analysis of the percentage contribution of individual sectors while determining the average conversion of emissions in tonnes per capita for individual countries, subsequently identifying the tendencies in the development of the detected rates. A cluster analysis for the EU28 that demonstrate similar carbon footprint values in the examined economic areas is conducted for the findings. The partial aim of the paper is to perform a comparison of the monitored countries and detect whether the differences between those striving for decarbonisation are diminishing. The energy industry is the most significant contributor to emission levels. The index analysis indicates that the level of emissions throughout the EU28 in all the monitored sectors has decreased, predominantly in waste management (by 40%,) which is followed by industry (17%), energy (by 16.2%), and agriculture (by 5%). The cluster analysis conducted for 2000 and 2017 has confirmed the convergence of the identified groups of the EU28. Individual clusters of the countries thus display minor differences and converge in general.

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Imaging of Joint and Soft Tissue Involvement in Systemic Lupus Erythematosus

Current Rheumatology Reports ◽

10.1007/s11926-021-01040-8 ◽

2021 ◽

Vol 23 (9) ◽

Author(s):

Andrea Di Matteo ◽

Gianluca Smerilli ◽

Edoardo Cipolletta ◽

Fausto Salaffi ◽

Rossella De Angelis ◽

...

Keyword(s):

Systemic Lupus Erythematosus ◽

Soft Tissue ◽

Lupus Erythematosus ◽

Structural Damage ◽

Structural Changes ◽

Soft Tissues ◽

Imaging Techniques ◽

Joint Involvement ◽

Systemic Lupus ◽

Muscle Involvement

Abstract Purpose of Review To highlight the potential uses and applications of imaging in the assessment of the most common and relevant musculoskeletal (MSK) manifestations in systemic lupus erythematosus (SLE). Recent Findings Ultrasound (US) and magnetic resonance imaging (MRI) are accurate and sensitive in the assessment of inflammation and structural damage at the joint and soft tissue structures in patients with SLE. The US is particularly helpful for the detection of joint and/or tendon inflammation in patients with arthralgia but without clinical synovitis, and for the early identification of bone erosions. MRI plays a key role in the early diagnosis of osteonecrosis and in the assessment of muscle involvement (i.e., myositis and myopathy). Conventional radiography (CR) remains the traditional gold standard for the evaluation of structural damage in patients with joint involvement, and for the study of bone pathology. The diagnostic value of CR is affected by the poor sensitivity in demonstrating early structural changes at joint and soft tissue level. Computed tomography allows a detailed evaluation of bone damage. However, the inability to distinguish different soft tissues and the need for ionizing radiation limit its use to selected clinical circumstances. Nuclear imaging techniques are valuable resources in patients with suspected bone infection (i.e., osteomyelitis), especially when MRI is contraindicated. Finally, dual energy X-ray absorptiometry represents the imaging mainstay for the assessment and monitoring of bone status in patients with or at-risk of osteoporosis. Summary Imaging provides relevant and valuable information in the assessment of MSK involvement in SLE.

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Dynamic Single-Fiber Pull-Out of Polypropylene Fibers Produced with Different Mechanical and Surface Properties for Concrete Reinforcement

Materials ◽

10.3390/ma14040722 ◽

2021 ◽

Vol 14 (4) ◽

pp. 722

Author(s):

Enrico Wölfel ◽

Harald Brünig ◽

Iurie Curosu ◽

Viktor Mechtcherine ◽

Christina Scheffler

Keyword(s):

Tensile Strength ◽

Dynamic Loading ◽

Melt Spinning ◽

Structural Changes ◽

High Surface ◽

Single Fiber ◽

Scanning Calorimetry ◽

Matrix Interaction ◽

Pull Out ◽

Fiber Matrix

In strain-hardening cement-based composites (SHCC), polypropylene (PP) fibers are often used to provide ductility through micro crack-bridging, in particular when subjected to high loading rates. For the purposeful material design of SHCC, fundamental research is required to understand the failure mechanisms depending on the mechanical properties of the fibers and the fiber–matrix interaction. Hence, PP fibers with diameters between 10 and 30 µm, differing tensile strength levels and Young’s moduli, but also circular and trilobal cross-sections were produced using melt-spinning equipment. The structural changes induced by the drawing parameters during the spinning process and surface modification by sizing were assessed in single-fiber tensile experiments and differential scanning calorimetry (DSC) of the fiber material. Scanning electron microscopy (SEM), atomic force microscopy (AFM) and contact angle measurements were applied to determine the topographical and wetting properties of the fiber surface. The fiber–matrix interaction under quasi-static and dynamic loading was studied in single-fiber pull-out experiments (SFPO). The main findings of microscale characterization showed that increased fiber tensile strength in combination with enhanced mechanical interlocking caused by high surface roughness led to improved energy absorption under dynamic loading. Further enhancement could be observed in the change from a circular to a trilobal fiber cross-section.

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Resource and waste quantification scenarios for wind turbine decommissioning in the United Kingdom

Waste Disposal & Sustainable Energy ◽

10.1007/s42768-020-00057-6 ◽

2020 ◽

Author(s):

Kiran Tota-Maharaj ◽

Alexander McMahon

Keyword(s):

United Kingdom ◽

Waste Management ◽

Wind Turbine ◽

End Of Life ◽

Wind Turbines ◽

Rapid Rise ◽

The United Kingdom ◽

Management Procedures ◽

The Uk ◽

Over Time

AbstractWind power produces more electricity than any other form of renewable energy in the United Kingdom (UK) and plays a key role in decarbonisation of the grid. Although wind energy is seen as a sustainable alternative to fossil fuels, there are still several environmental impacts associated with all stages of the lifecycle of a wind farm. This study determined the material composition for wind turbines for various sizes and designs and the prevalence of such turbines over time, to accurately quantify waste generation following wind turbine decommissioning in the UK. The end of life stage is becoming increasingly important as a rapid rise in installation rates suggests an equally rapid rise in decommissioning rates can be expected as wind turbines reach the end of their 20–25-year operational lifetime. Waste data analytics were applied in this study for the UK in 5-year intervals, stemming from 2000 to 2039. Current practices for end of life waste management procedures have been analysed to create baseline scenarios. These scenarios have been used to explore potential waste management mitigation options for various materials and components such as reuse, remanufacture, recycling, and heat recovery from incineration. Six scenarios were then developed based on these waste management options, which have demonstrated the significant environmental benefits of such practices through quantification of waste reduction and greenhouse gas (GHG) emissions savings. For the 2015–2019 time period, over 35 kilotonnes of waste are expected to be generated annually. Overall waste is expected to increase over time to more than 1200 kilotonnes annually by 2039. Concrete is expected to account for the majority of waste associated with wind turbine decommissioning initially due to foundations for onshore turbines accounting for approximately 80% of their total weight. By 2035–2039, steel waste is expected to account for almost 50% of overall waste due to the emergence of offshore turbines, the foundations of which are predominantly made of steel.

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Zika RNA and Flavivirus-Like Antigens in the Sperm Cells of Symptomatic and Asymptomatic Subjects

Viruses ◽

10.3390/v13020152 ◽

2021 ◽

Vol 13 (2) ◽

pp. 152

Author(s):

Hernan Vanegas ◽

Fredman González ◽

Yaoska Reyes ◽

Edwing Centeno ◽

Jayrintzina Palacios ◽

...

Keyword(s):

Clinical Symptoms ◽

Time Frame ◽

Sperm Cells ◽

Human Semen ◽

Zikv Infection ◽

Virus Shedding ◽

One Year ◽

Asymptomatic Subjects ◽

A Prospective Study ◽

Male Subjects

Zika virus (ZIKV) RNA has been found to remain in human semen for up to one year after infection, but the presence of Flavivirus antigens in the different compartments of semen has been largely unexplored. Following the introduction of ZIKV in Nicaragua (2016), a prospective study of patients with clinical symptoms consistent with ZIKV was conducted in León to investigate virus shedding in different fluids. ZIKV infection was confirmed in 16 male subjects (≥18 years of age) by RT-qPCR in either blood, saliva or urine. Of these, three provided semen samples at 7, 14, 21, 28, 60 and 180 days postsymptom onset (DPSO) for Flavivirus antigens and RNA studies. These cases were compared with 19 asymptomatic controls. Flavivirus antigens were examined by immunofluorescence (IF) using the 4G2 Mabs, and confocal microscopy was used to explore fluorescence patterns. The three (100%) symptomatic subjects and 3 (16%) of the 19 asymptomatic subjects had Flavivirus antigens and viral RNA in the spermatozoa fraction. The percentage of IF Flavivirus-positive spermatozoa cells ranged from 1.9% to 25% in specimens from symptomatic subjects, as compared with 0.8% to 3.8% in specimens from asymptomatic controls. A marked IF-pattern in the cytoplasmic droplets and tail of the spermatozoa was observed. The sperm concentrations (45 × 106/mL vs. 63.5 × 106/mL, p = 0.041) and the total motility percentage (54% vs. 75%, p = 0.009) were significantly lower in specimens from ZIKV-positive than in those of ZIKV-negative. In conclusion, this study demonstrated the presence of Flavivirus antigens and RNA within a time frame of 28 DPSO in sperm cells of symptomatic and asymptomatic subjects during the ZIKV epidemic. These findings have implications for public health, in terms of nonarthropod-born, silent transmission facilitated by sperm cells and potential transmission from asymptomatic males to pregnant women, with consequences to the fetus.

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Biochemical Methane Potential of Cork Boiling Wastewater at Different Inoculum to Substrate Ratios

Applied Sciences ◽

10.3390/app11073064 ◽

2021 ◽

Vol 11 (7) ◽

pp. 3064

Author(s):

Roberta Mota-Panizio ◽

Manuel Jesús Hermoso-Orzáez ◽

Luis Carmo-Calado ◽

Gonçalo Lourinho ◽

Paulo Sérgio Duque de Brito

Keyword(s):

Anaerobic Digestion ◽

Biogas Production ◽

Treatment Plant ◽

Organic Substrates ◽

Biochemical Methane Potential ◽

Volatile Solids ◽

Working Volume ◽

Methane Potential ◽

Bmp Test ◽

Cork Industry

The present study evaluates the digestion of cork boiling wastewater (CBW) through a biochemical methane potential (BMP) test. BMP assays were carried out with a working volume of 600 mL at a constant mesophilic temperature (35 °C). The experiment bottles contained CBW and inoculum (digested sludge from a wastewater treatment plant (WWTP)), with a ratio of inoculum/substrate (Ino/CBW) of 1:1 and 2:1 on the basis of volatile solids (VSs); the codigestion with food waste (FW) had a ratio of 2/0.7:0.3 (Ino/CBW:FW) and the codigestion with cow manure (CM) had a ratio of 2/0.5:0.5 (Ino/CBW:CM). Biogas and methane production was proportional to the inoculum substrate ratio (ISR) used. BMP tests have proved to be valuable for inferring the adequacy of anaerobic digestion to treat wastewater from the cork industry. The results indicate that the biomethane potential of CBWs for Ino/CBW ratios 1:1 and 2:1 is very low compared to other organic substrates. For the codigestion tests, the test with the Ino/CBW:CM ratio of 2/0.7:0.3 showed better biomethane yields, being in the expected values. This demonstrated that it is possible to perform the anaerobic digestion (AD) of CBW using a cosubstrate to increase biogas production and biomethane and to improve the quality of the final digestate.

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Comparative Study of Structural Changes of Polylactide and Poly(ethylene terephthalate) in the Presence of Trichoderma viride

International Journal of Molecular Sciences ◽

10.3390/ijms22073491 ◽

2021 ◽

Vol 22 (7) ◽

pp. 3491

Author(s):

Grażyna B. Dąbrowska ◽

Zuzanna Garstecka ◽

Ewa Olewnik-Kruszkowska ◽

Grażyna Szczepańska ◽

Maciej Ostrowski ◽

...

Keyword(s):

Structural Changes ◽

Ethylene Terephthalate ◽

Molecular Mechanisms ◽

Blot Hybridization ◽

Trichoderma Viride ◽

Cost Effective ◽

Plastic Pollution ◽

Scanning Calorimetry ◽

Poly Ethylene Terephthalate ◽

Poly Ethylene

Plastic pollution is one of the crucial global challenges nowadays, and biodegradation is a promising approach to manage plastic waste in an environment-friendly and cost-effective way. In this study we identified the strain of fungus Trichoderma viride GZ1, which was characterized by particularly high pectinolytic activity. Using differential scanning calorimetry, Fourier-transform infrared spectroscopy techniques, and viscosity measurements we showed that three-month incubation of polylactide and polyethylene terephthalate in the presence of the fungus lead to significant changes of the surface of polylactide. Further, to gain insight into molecular mechanisms underneath the biodegradation process, western blot hybridization was used to show that in the presence of poly(ethylene terephthalate) (PET) in laboratory conditions the fungus produced hydrophobin proteins. The mycelium adhered to the plastic surface, which was confirmed by scanning electron microscopy, possibly due to the presence of hydrophobins. Further, using atomic force microscopy we demonstrated for the first time the formation of hydrophobin film on the surface of aliphatic polylactide (PLA) and PET by T. viride GZ1. This is the first stage of research that will be continued under environmental conditions, potentially leading to a practical application.

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Metastable Intermediates as Stepping Stones on the Maturation Pathways of Viral Capsids

mBio ◽

10.1128/mbio.02067-14 ◽

2014 ◽

Vol 5 (6) ◽

Cited By ~ 10

Author(s):

Giovanni Cardone ◽

Robert L. Duda ◽

Naiqian Cheng ◽

Lili You ◽

James F. Conway ◽

...

Keyword(s):

Conformational Changes ◽

Large Scale ◽

Structural Changes ◽

Energy Landscape ◽

Potential Hazard ◽

Stepping Stones ◽

Scanning Calorimetry ◽

Conformational Effects ◽

Capsid Maturation ◽

Capsid Integrity

ABSTRACT As they mature, many capsids undergo massive conformational changes that transform their stability, reactivity, and capacity for DNA. In some cases, maturation proceeds via one or more intermediate states. These structures represent local minima in a rich energy landscape that combines contributions from subunit folding, association of subunits into capsomers, and intercapsomer interactions. We have used scanning calorimetry and cryo-electron microscopy to explore the range of capsid conformations accessible to bacteriophage HK97. To separate conformational effects from those associated with covalent cross-linking (a stabilization mechanism of HK97), a cross-link-incompetent mutant was used. The mature capsid Head I undergoes an endothermic phase transition at 60°C in which it shrinks by 7%, primarily through changes in its hexamer conformation. The transition is reversible, with a half-life of ~3 min; however, >50% of reverted capsids are severely distorted or ruptured. This observation implies that such damage is a potential hazard of large-scale structural changes such as those involved in maturation. Assuming that the risk is lower for smaller changes, this suggests a rationalization for the existence of metastable intermediates: that they serve as stepping stones that preserve capsid integrity as it switches between the radically different conformations of its precursor and mature states. IMPORTANCE Large-scale conformational changes are widespread in virus maturation and infection processes. These changes are accompanied by the release of conformational free energy as the virion (or fusogenic glycoprotein) switches from a precursor state to its mature state. Each state corresponds to a local minimum in an energy landscape. The conformational changes in capsid maturation are so radical that the question arises of how maturing capsids avoid being torn apart. Offering proof of principle, severe damage is inflicted when a bacteriophage HK97 capsid reverts from the (nonphysiological) state that it enters when heated past 60°C. We suggest that capsid proteins have been selected in part by the criterion of being able to avoid sustaining collateral damage as they mature. One way of achieving this—as with the HK97 capsid—involves breaking the overall transition down into several smaller steps in which the risk of damage is reduced.

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Thermo-Optical Properties of Perfluorinated Sulfonic Acid Membranes: An Investigation of Hydration Based on Absorption Spectra

Applied Spectroscopy ◽

10.1177/0003702817723649 ◽

2017 ◽

Vol 71 (11) ◽

pp. 2504-2511 ◽

Cited By ~ 1

Author(s):

Daniele T. Dias ◽

Guy Lopes ◽

Tales Ferreira ◽

Ivanir L. Oliveira ◽

Caroline D. Rosa

Keyword(s):

Sulfonic Acid ◽

Room Temperature ◽

Water Retention ◽

Structural Changes ◽

Optical Characterization ◽

Scanning Calorimetry ◽

Experimental Procedure ◽

Nafion Membranes ◽

Perfluorinated Sulfonic Acid

The Nafion membranes are widely used in electrochemical applications such as fuel cells, chlor-alkali cells, and actuators–sensors. In this work, the thermal-optical characterization of Nafion in acid form was performed by photoacoustic spectroscopy, thermogravimetry, and differential scanning calorimetry. In the experimental procedure three distinct hydration levels were considered: (1) pristine membrane (λ ≅ H2O/–SO3H ≅ 5.6); (2) swelling process (λ ≅ 17.4); and (3) drying at controlled room temperature after swelling process (λ ≅ 6.5). The discovered behaviors showed significant irreversible structural changes induced by water retention in the membrane. These structural changes depend on the water population present in the clusters and also affect the directional thermal diffusivity of the membrane irreversibly.

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