Biodegradable Materials Used in FDM 3D Printing Technology: A Critical Review

Abstract: Three-dimensional (3D) printing is a flexible technique that has attracted increasing interest in recent years. 3D printing has powerful biodegradable materials that are important for environmental protection and emergencies such as COVID-19. To achieve better compatibility for customized and enhanced material characteristics, a variety of ways have been used. Companies and researchers are increasingly interested in biodegradable polymers and composites due to their easy production, eco-friendly, and suitability for a variety of applications. One small step toward protecting the world around us is the use of natural resources to produce fully or partially biodegradable composite materials. PHA (Polyhydroxyalkanoates), PLA (Polylacticacid), High impact polystyrene (HIPS), and PHB (Polyhydroxybutyrates) are examples of bioplastics that are produced and have similar functionality to conventional plastics while also being biodegradable. These materials have the potential to reduce our reliance on petroleum-based plastic, which may present environmental risks. Every country desperately needs to develop bioplastic usage and proper waste management for a pollution-free world. This review is expected to provide a general overview for 3D-printed biodegradable polymer and their applications using fused deposition modelling (FDM) technology

Identification of tick-borne encephalitis virus in ticks collected in southeastern Hungary

Tick-borne encephalitis virus (TBEV) is an arthropod-borne viral pathogen causing infections in Europe and is responsible for most arbovirus central nervous system infections in Hungary. Assessing the TBEV prevalence in ticks through detection of genomic RNA is a broadly accepted approach to estimate the transmission risk from a tick bite. For this purpose, 2731 ticks were collected from the neighboring area of the town of Dévaványa, located in southeastern Hungary, which is considered a low-risk-transmission area for TBEV. Altogether, 2300 ticks were collected from the vegetation, while 431 were collected from rodents. Samples were pooled and then screened for TBEV with a newly designed semi-nested RT-PCR (RT-snPCR) targeting the NS1 genomic region. PCR results were confirmed by direct sequencing of the sec- ond round amplicons. Among the 3 different collected tick species ( Ixodes ricinus , Haemaphysalis concinna , Dermacentor marginatus ), I. ricinus was the only species that tested positive for TBEV. TBEV-positive ticks were collected from small mammals or from the vegetation. One nymphal pool and 4 larval pools tested positive for TBEV. The only positive nymphal pool was unfed and came from vegetation, while ticks of the 4 positive larval pools were collected from rodents. Minimal TBEV prevalence in ticks was 0.08% for unfed nymphs and 0.78% for feeding larvae. Our results indicate that further long-term investigations on the occurrence of TBEV are needed to better describe the geographic distribution and the prevalence of infected ticks in Hungar

Spectrally tunable ultrashort monochromatized extreme ultraviolet pulses at 100 kHz

We present the experimental realization of spectrally tunable, ultrashort, quasi-monochromatic extreme ultraviolet (XUV) pulses generated at 100 kHz repetition rate in a user-oriented gas high harmonic generation beamline of the Extreme Light Infrastructure—Attosecond Light Pulse Source facility. Versatile spectral and temporal shaping of the XUV pulses is accomplished with a double-grating, time-delay compensated monochromator accommodating the two composing stages in a novel, asymmetrical geometry. This configuration supports the achievement of high monochromatic XUV flux (2.8 ± 0.9 × 1010 photons/s at 39.7 eV selected with 700 meV full width at half maximum bandwidth) combined with ultrashort pulse duration (4.0 ± 0.2 fs using 12.1 ± 0.6 fs driving pulses) and small spot size (sub-100 µm). Focusability, spectral bandwidth, and overall photon flux of the produced radiation were investigated, covering a wide range of instrumental configurations. Moreover, complete temporal (intensity and phase) characterization of the few-femtosecond monochromatic XUV pulses—a goal that is difficult to achieve by conventional reconstruction techniques—has been realized using a ptychographic algorithm on experimentally recorded XUV-infrared pump-probe traces. The presented results contribute to in situ, time-resolved experiments, accessing direct information on the electronic structure dynamics of novel target materials

Increased micronutrient content (Zn, Mn) in the 3Mb(4B) wheat- Aegilops biuncialis substitution and 3Mb.4BS translocation identified by GISH and FISH

3Mb Triticum aestivum L. (Mv9kr1)-Aegilops biuncialis Vis. (MvGB642) addition lines were crossed with the Chinese Spring ph1b mutant genotype (CSph1b) to produce 3Mb-wheat chromosome rearrangements. In the F3 generation, 3Mb(4B) substitution lines and 3M b.4BS centric fusions were identified with in situ hybridization using repetitive and genomic DNA probes, and with SSR markers. Grain micronutrient analysis showed that the investigated Ae. biuncialis accession MvGB382 and the parental line MvGB642 are suitable gene sources for improving the grain micronutrient content of wheat, as they have higher K, Zn, Fe, and Mn contents. The results suggested that the Ae. biuncialis chromosome 3M b carries genes determining the grain micronutrient content, as the 3Mb.4BS centric fusion had significantly higher Zn and Mn contents compared with the recipient wheat cultivar. As yield-related traits, such as the number of tillers, the length of main spike, and spikelets per main spike, were similar in the 3Mb.4BS centric fusion and the parental wheat genotype, it can be concluded that this line could be used in pre-breeding programs aimed at enriching elite wheat cultivars with essential micronutrients. | Des lignées d'addition 3Mb Triticum aestivum L. (Mv9kr1) – Aegilops biuncialis Vis. (MvGB642) ont été croisées avec le mutant Chinese Spring ph1b (CSph1b) afin de produire des réarrangements chromosomiques 3Mb–blé. Au sein de la génération F3, des lignées de substitution 3Mb(4B) et des fusions centriques 3Mb.4BS ont été identifiées par hybridation in situ au moyen de sondes d'ADN répété ou génomique ainsi qu'avec des marqueurs SSR. Une analyse de la composition du grain en matière de micronutriments a montré que l'accession étudiée de l'Ae. biuncialis (MvGB382) et la lignée parentale MvGB642 constituent des sources valables pour améliorer le contenu en micronutriments chez le blé, du fait qu'elles ont une teneur accrue en K, Zn, Fe et Mn. Ces résultats suggèrent que le chromosome 3Mb de l'Ae. biuncialis porte des gènes contribuant a` déterminer le contenu en micronutriments puisque la fusion centrique 3Mb.4BS présentait un contenu en Zn et en Mn significativement supérieur a` la variété de blé réceptrice. Puisque les composantes de rendement comme le nombre de talles, la longueur de la tige principale et le nombre d'épillets par épi étaient semblables chez la fusion centrique 3Mb.4BS et chez le génotype de blé parental, les auteurs en concluent que cette lignée pourrait s'avérer utile dans des programmes de pré-sélection visant a` accroître la teneur en micronutriments essentiels chez les cultivars élites de blé. [Traduit par la Rédaction

Assessment of Heavy Metal and Pesticide Levels in Soil and Plant Products from Agricultural Area of Belgrade, Serbia

This study was aimed to assess the levels of selected heavy metals and pesticides in soil and plant products from an agricultural area of Belgrade, Serbia and to indicate possible sources and risks of contamination. Soil, vegetable, and fruit samples from the most important agricultural city areas were collected from July to November of 2006. Metal contents were determined by atomic absorption spectrometry, whereas pesticide residues were analyzed by gas chromatography-mass spectrometry after extraction performed using solid-phase microextraction technique. Soil characterization based on the determination of selected physical and chemical properties revealed heterogeneous soils belonging to different soil groups. The concentrations of lead, cadmium, copper, and zinc in soil samples do not exceed the limits established by national and international regulations. Residues of the herbicide atrazine were detected in three soil samples, with levels lower than the relevant limit. The presence of other herbicides, namely prometryn, chloridazon, acetochlor, flurochloridone, and napropamide, was registered in some soil samples as well. Among the insecticides investigated in the soil, fenitrothion and chlorpyrifos were the only ones detected. In most of the investigated vegetable samples from the Obrenovac area, Pb and Cd contents are higher in comparison with the maximum levels, indicating the emission of coal combustion products from local thermal power plants as a possible source of contamination. Residue levels of some herbicides and insecticides (metribuzin, trifluralin, pendimethalin, bifenthrin, chlorpyrifos, and cypermethrin) determined in tomato, pepper, potato, and onion samples from Slanci, Ova, and Obrenovac areas are even several times higher than the maximum residue levels. Inappropriate use of these plant protection products is considered to be the most probable reason of contamination. Because increased levels of heavy metals and pesticide residues found in plant products could pose a risk to consumers' health, their continual monitoring before product distribution to city markets is indispensable

A detailed investigation of single-photon laser enabled Auger decay in neon

Single-photon Laser Enabled Auger Decay (spLEAD) is an electronic de-excitation process which was recently predicted and observed in Ne. We have investigated it using bichromatic phase-locked Free Electron Laser radiation and extensive angle-resolved photoelectron measurements, supported by a detailed theoretical model. We first used separately the fundamental wavelength resonant with the Ne+ 2s-2p transition, 46.17 nm, and its second harmonic, 23.08 nm, then their phase-locked bichromatic combination. In the latter case the phase difference between the two wavelengths was scanned, and interference effects were observed, confirming that the spLEAD process was occurring. The detailed theoretical model we developed qualitatively predicts all observations: branching ratios between the final Auger states, their amplitudes of oscillation as a function of phase, the phase lag between the oscillations of different final states, and partial cancellation of the oscillations under certain conditions