-
Scientific Reports Jun 2024Microporous organic polymers that have three-dimensional connectivity stemming from monomers with tetrahedral or tetrahedron-like geometry can have high surface areas...
Microporous organic polymers that have three-dimensional connectivity stemming from monomers with tetrahedral or tetrahedron-like geometry can have high surface areas and strong fluorescence. There are however few examples of such polymers based on hindered biaryls, and their fluorescence has not been studied. Hypothesizing that the contortion in a hindered biphenyl moiety would modulate the optical properties of a polymer built from it, we synthesized a meta-enchained polyphenylene from a 2,2',6,6'-tetramethylbiphenyl-based monomer, in which the two phenyl rings are nearly mutually perpendicular. The polymer was microporous with S = 495 m g. The polymer absorbed near-UV light and emitted blue fluorescence despite the meta-enchainment that would have been expected to break the conjugation. A related copolymer, synthesized from 2,2',6,6'-tetramethylbiphenyl-based and unsubstituted biphenyl-based monomers, was microporous but not fluorescent.
PubMed: 38942951
DOI: 10.1038/s41598-024-65743-5 -
Scientific Reports Jun 2024The increasing water contamination by toxic heavy metals, particularly hexavalent chromium, has become a significant environmental concern. This study explores the...
The increasing water contamination by toxic heavy metals, particularly hexavalent chromium, has become a significant environmental concern. This study explores the pyrolysis of termite-processed biomass, specifically Pinus elliottii particleboard and its termite droppings (TDs), to produce biochar and its application for chromium (VI) adsorption. Termite droppings, rich in lignin, and particleboard, rich in cellulose, were pyrolyzed at various temperatures to assess the effect of biomass composition on biochar properties. The study found that lignin-rich termite droppings produced biochar with higher fixed carbon content and specific surface area than cellulose-rich particleboard biochar. FTIR and Raman spectroscopy revealed significant molecular structure changes during pyrolysis, which influenced the adsorption capabilities of the biochar. Adsorption experiments demonstrated that TD biochar exhibited significantly higher chromium (VI) adsorption capacity, attributed to its distinct chemical composition and enhanced surface properties due to higher lignin content. These findings underscore the crucial role of lignin in producing efficient biochar for heavy metal adsorption, highlighting the practical applicability of termite-processed biomass in water purification technologies.
Topics: Charcoal; Lignin; Chromium; Animals; Cellulose; Biomass; Adsorption; Isoptera; Water Pollutants, Chemical; Pyrolysis; Pinus; Water Purification; Spectroscopy, Fourier Transform Infrared
PubMed: 38942919
DOI: 10.1038/s41598-024-65959-5 -
Scientific Data Jun 2024Time-course transcriptome expression data were constructed for four parts of the silk gland (anterior, middle, and posterior parts of the middle silk gland, along with...
Time-course transcriptome expression data were constructed for four parts of the silk gland (anterior, middle, and posterior parts of the middle silk gland, along with the posterior silk gland) in the domestic silkworm, Bombyx mori, from days 0 to 7 of the last-instar larvae. For sample preparation, silk glands were extracted from one female and one male larva every 24 hours accurately after the fourth ecdysis. The reliability of these transcriptome data was confirmed by comparing the transcripts per million (TPM) values of the silk gene and quantitative reverse transcription PCR results. Hierarchical cluster analysis results supported the reliability of transcriptome data. These data are likely to contribute to the progress in molecular biology and genetic research using B. mori, such as elucidating the mechanism underlying the massive production of silk proteins, conducting entomological research using a meta-analysis as a model for lepidopteran insect species, and exploring medical research using B. mori as a model for disease species by utilising transcriptome data.
Topics: Bombyx; Animals; Larva; Transcriptome; Female; Male; Silk
PubMed: 38942767
DOI: 10.1038/s41597-024-03560-1 -
Journal of Dairy Science Jul 2024This study investigated the effects of feeding an amylase-enabled corn silage (ACS) on the performance and enteric gas emissions in lactating dairy cows. Following a...
This study investigated the effects of feeding an amylase-enabled corn silage (ACS) on the performance and enteric gas emissions in lactating dairy cows. Following a 2-wk covariate period, 48 mid-lactation Holstein cows were assigned to 1 of 3 treatments in a 10-wk randomized complete block design experiment. Treatments were diets containing the same proportion of corn silage (40% of dietary DM) as follows: (1) a conventional hybrid corn silage control (CON), (2) ACS replacing the control silage (ADR), and (3) the ADR diet replacing soybean hulls with ground corn grain to achieve the same dietary starch concentration as CON (ASR). Control corn silage and ACS were harvested on the same day and contained 40.3% and 37.1% DM and (% of DM): 37.2% and 41.0% NDF and 37.1% and 30.0% starch, respectively. Enteric gas emissions were measured using the GreenFeed system. Two cows were culled due to health-related issues during the covariate period. Ruminal fluid was collected from 24 cows (8 per treatment) using the orogastric ruminal sampling technique. When compared with CON, cows fed ADR had increased DMI during experimental wk 3, 4, and 9, but treatment did not affect milk or ECM milk yields (39.0 kg/d on average; SEM = 0.89). Compared with CON, feed efficiency (per unit of milk, but not ECM) tended to be lower for ADR, whereas milk true protein concentration (a tendency) and yield were lower for ASR. Milk urea N was decreased by both ADR and ASR diets relative to CON. Compared with CON, daily CH emission and emission intensity were increased by ADR but not ASR. Total protozoal count tended to be increased by both diets formulated with ACS when compared with control corn silage. Total-tract digestibility of dietary NDF was greater for ASR, and that of ADF was greater for both ADR and ASR versus CON. The molar proportion of acetate (a tendency) and acetate-to-propionate ratio were increased by ADR, but not ASR, when compared with CON. Replacement of CON with ACS (having lower starch concentration) in the diet of dairy cows increased DMI during the initial weeks of the experiment, maintained ECM, tended to decrease feed efficiency, and increased enteric CH emissions, likely due to increased intake of digestible fiber, compared with CON.
Topics: Animals; Cattle; Female; Starch; Lactation; Zea mays; Silage; Rumen; Diet; Milk; Fermentation; Amylases; Animal Feed; Gases
PubMed: 38942561
DOI: 10.3168/jds.2023-23957 -
Korean Journal of Radiology Jul 2024
Topics: Humans; Pulmonary Artery; Iatrogenic Disease; Enbucrilate; Male; Embolization, Therapeutic; Female; Middle Aged
PubMed: 38942462
DOI: 10.3348/kjr.2024.0311 -
International Journal of Biological... Jun 2024Cellulose modified hydrogels can be produced directly from raw biopolymers in novel cellulose solvents such as NaOH/urea aqueous solution. The effect of cellulose...
Cellulose modified hydrogels can be produced directly from raw biopolymers in novel cellulose solvents such as NaOH/urea aqueous solution. The effect of cellulose characteristics on the synthesis of a cellulose-graft-(net-poly(acrylamide-co-acrylic acid)) and its performance as water absorbent/methylene blue dye removal material is analyzed. Three cellulose samples, one analytical grade and two obtained from teak wood sawdust with different pretreatments (one alkaline and the other, a novel one known as (gas phase) acid pretreatment) were compared. The starting raw celluloses were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray diffraction (XRD) and viscosity in cupri ethylenediamine hydroxide (CED) solution, whereas the chemically modified materials were characterized by SEM, FTIR, and TGA. The pretreatment used influences composition, crystallinity index and degree of polymerization (DP) of the cellulose obtained. The modified material produced with cellulose from alkaline pretreatment showed the highest swelling ratio in water absorption tests at room temperature (12,714 %); in contrast, the one with cellulose from acid pretreatment showed the lowest swelling ratio (7,470 %). However, this difference is not so significative in dye removal tests, where absorption capacity is 139 and 140 mg/g, respectively. The results indicate that cellulose composition, particularly structures with significant hemicellulose and lignin remaining content, has a major effect on the performance of modified materials for water absorption, and degree of polymerization has a major effect on adsorption capacity of methylene blue.
PubMed: 38942409
DOI: 10.1016/j.ijbiomac.2024.133482 -
The Science of the Total Environment Jun 2024Soil environments across the globe, particularly in agricultural settings, have now been shown to be contaminated with microplastics. Agricultural plastics - such as...
Soil environments across the globe, particularly in agricultural settings, have now been shown to be contaminated with microplastics. Agricultural plastics - such as mulching films - are used in close or direct contact with soils and there is growing evidence demonstrating that they represent a potential source of microplastics. There is a demand to undertake fate and effects studies to understand the behaviour and potential long-term ecological risks of this contamination. Yet, there is a lack of test materials available for this purpose. This study describes the manufacture and characterisation of five large (1-40 kg) batches of microplastic test materials derived from agricultural mulching films. Batches were produced from either polyethylene-based conventional mulching films or starch-polybutadiene adipate terephthalate blend mulching films that are certified biodegradable in soil. Challenges encountered and overcome during the micronisation process provide valuable insights into the future of microplastic test material generation from these material types. This includes difficulties in micronising virgin polyethylene film materials. All five batches were subjected to a thorough physical and chemical characterisation - both of the original virgin films and the subsequent microplastic particles generated - including a screening for the presence of chemical additives. This is a critical step to provide essential information for interpreting particle fate or effects in scientific testing. Trade-offs between obtaining preferred particle typologies and time and cost constraints are elucidated. Several recommendations emerging from the experiences gained in this study are put forward to advance the research field towards greater harmonisation and utilisation of environmentally relevant test materials.
PubMed: 38942306
DOI: 10.1016/j.scitotenv.2024.174325 -
European Journal of Dentistry Jun 2024The proper closure of the access cavity between appointments during endodontic treatment is paramount and relies on temporary fillings. This systematic review evaluates...
The proper closure of the access cavity between appointments during endodontic treatment is paramount and relies on temporary fillings. This systematic review evaluates the effectiveness of zinc oxide-based materials and glass-ionomer cement (GIC) as temporary coronal sealers after root canal treatment in extracted human teeth. Three databases were searched to identify randomized clinical trials that examined the sealing properties of various temporary sealing materials using dyes or stains as indicators. A total of seven studies that fulfilled the eligibility criteria were critically analyzed. These indicated significant variations in the relative sealing ability of the coronal breach of endodontically treated teeth, either by zinc oxide or GIC-based materials. While GIC-based material (e.g., Fuji IX and Fuji II) exhibited superior sealing of single-rooted teeth, zinc oxide-based material (e.g., Cavit, Coltosol, Caviton) also showed promising attributes. Resin-modified GIC formulations displayed enhanced physical properties, yet challenges related to adhesive failure and shrinkage during polymerization were observed. Zinc oxide-based materials have demonstrated superior coronal sealing effectiveness over certain GIC in controlled settings. Their premixed nature ensures consistent application and hygroscopic properties improve cavity sealing. However, the focus on dye penetration tests for microleakage may not fully represent the risk of bacterial infiltration. Thus, studies are crucial for validating these findings in clinical contexts.
PubMed: 38942056
DOI: 10.1055/s-0044-1782695 -
Journal of Hazardous Materials Jun 2024Water pollution from industrial or household waste, containing dyes from the textile industry, poses a significant environmental challenge requiring immediate attention....
Water pollution from industrial or household waste, containing dyes from the textile industry, poses a significant environmental challenge requiring immediate attention. In this study, we have developed a crosslinked-smart-polymer film based on 2-(dimethylamino)ethyl methacrylate copolymerized with other hydrophilic and hydrophobic commercial monomers, and its efficacy in removing 21 different textile dyes was assessed. The smart polymer effectively interacts with and adsorbs dyes, inducing a noticeable colour change. UV-Vis spectroscopy analysis confirmed a removal efficiency exceeding 90 % for anionic dyes, with external diffusion identified as the primary influencing factor on process kinetics, consistent with both pseudo-first-order kinetics and the Crank-Dual model. Isothermal studies revealed distinct adsorption behaviors, with indigo carmine adhering to a Freundlich isotherm while others conformed to the Langmuir model. Permeation and fluorescence analyses corroborated isotherm observations, verifying surface adsorption. Significantly, our proof-of-concept demonstrated the resilience of the smart-film to common fabric softeners and detergents without compromising adsorption capacity. Additionally, the material exhibited reusability (for at least 5 cycles), durability, and good thermal and mechanical properties, with T and T values of 265 °C and 342 °C, respectively, a Tg of 168 °C, and a water swelling percentage of 54.3 %, thus confirming its stability and suitability for industrial application. ENVIRONMENTAL IMPLICATION: Dyes released during laundry processes should be classified as "hazardous materials" owing to their significant toxicity towards aquatic organisms, with the potential to disrupt ecosystems and harm aquatic biodiversity. This paper discusses the development of a novel acrylic material in film form, engineered to extract toxic anionic dyes. This study directly contributes to mitigating the environmental impact associated with the fashion industry and the domestic use of textiles. It can be implemented on both an industrial and personal scale, thereby encouraging more sustainable practices and promoting collaborative citizen science efforts towards.
PubMed: 38941828
DOI: 10.1016/j.jhazmat.2024.135006 -
Ultrasonics Sonochemistry Jun 2024Ultrasonic technology has a significant degassing effect and can increase the efficiency of hydrogen production in the proton exchange membrane electrolysis of water....
Ultrasonic technology has a significant degassing effect and can increase the efficiency of hydrogen production in the proton exchange membrane electrolysis of water. However, further research is needed to understand its influence mechanism on hydrogen bubbles. In this work, a kinetic analysis is performed to investigate the principle of hydrogen production and the kinetic behaviour of hydrogen bubble evolution by applying the ultrasonic amplification technique under static and flow dynamics in the proton exchange membrane electrolysis cell. The evolution of hydrogen bubbles in the static and in the flow dynamic of the aqueous electrolyte solution under ultrasound was characterised by imaging. The results show that the aqueous electrolyte solution in the flow state reduces the size of hydrogen bubbles and increases the detachment speed compared to the static state, which promotes the process of hydrogen bubble evolution, and that the thermal effect of ultrasound on the temperature of the aqueous electrolyte solution in the flow state is very small compared to the static state and can be ignored. Ultrasound has different effects on the different stages of hydrogen bubble evolution. In the nucleation stage, the ultrasonic cavitation effect increases the highly reactive radicals such as •OH, H•, etc., and the mechanical vibration effect of ultrasound increases the nucleation sites, which are denser and more evenly distributed. In the growth phase, the ultrasonic cavitation effect and the mechanical vibration effect promote the breaking of hydrogen bonds of water molecules and improve mass transport, which promotes the growth of hydrogen bubbles, and the fluctuating energy of positive and negative ultrasound promotes the growth of hydrogen bubbles with the vibration speed. In the detachment phase, the radius of the hydrogen bubbles is influenced by the ultrasound. The radius of the hydrogen bubbles changes with the positive and negative ultrasonic pressure, the radius of the hydrogen bubbles at negative ultrasonic pressure increases, the positive ultrasonic pressure decreases, the changing effect of the radius of the hydrogen bubbles favours the detachment of the hydrogen bubbles. In the polymerisation phase, the ultrasound leads to increased polymerisation of the fine bubble streams. Ultrasound contributes to the hydrogen production effect of proton exchange membrane water electrolysis in actual operation.
PubMed: 38941702
DOI: 10.1016/j.ultsonch.2024.106968