Short Chain Research Articles

Production of biodiesel (isopropyl ester) from coconut oil by microwave assisted transesterification: parametric study and optimization

Biodiesel, a renewable fuel for diesel vehicle engines, has been commonly produced from transesterification process involving triglycerides from vegetable oil with alcohol. One of the most promising candidates for vegetable oil due to its abundance in Indonesia is coconut oil. However, the short carbon chain present in coconut oil necessitates the use of longer-chain alcohol types to adjust to the biodiesel carbon chain, such as isopropanol. Therefore, this research focused on producing biodiesel (isopropyl ester) from coconut oil using isopropanol and NaOH catalyst through a transesterification process. To enhance this process, microwave technology was utilized for its ability to lower the biodiesel production reaction time from the conventional one-hour timeframe to less than ten minutes, increase energy efficiency, and improve biodiesel quality. The primary objective was to investigate the impact of reaction time, catalyst concentration, and microwave power on the isopropyl ester yield. Further optimization was conducted using Response Surface Methodology (RSM) with Box-Behnken Design (BBD) to illustrate the model's effectiveness and applicability. Based on BBD optimization simulation, the optimal condition for producing isopropyl ester from coconut oil using microwave technology is a 1-minute reaction time, 0.2 wt.% NaOH catalyst concentration, and 443.9 W microwave power, maximizing the yield to 99.89%. This research highlights the potential of microwave assisted transesterification and the reliability of this innovative approach, contributing to the development of isopropyl ester production with enhanced quality that meets the specifications of the Indonesian National Standard (SNI).

Structural elucidation of mulberry leaf oligosaccharide and its selective promotion of gut microbiota to alleviate type 2 diabetes mellitus

Two oligosaccharide fractions (MLO 2-1 and 2-2) were purified from enzymatic hydrolysate of mulberry leaf polysaccharide. The results of simulated digestion showed that MLO 2-2 was a digestible oligosaccharide, which could be degraded by human digestive juice; while MLO 2-1 possessed the non-digestible property in the upper gastrointestinal tract and performed the function by regulating the gut microbiota. Hence, MLO 2-1 was selected for the further analysis. The structure of MLO 2-1 was elucidated as follow: α-T-Glcp-(1→3)-β-Glcp-(1→5)-α-Araf-(1→5) -α-Araf-1→5)-α-Araf-(1→3)-α-(2-OAc)-Glcp-1. The in vitro fecal fermentation results showed that MLO 2-1 could modulate the composition of gut microbiota. Meanwhile, MLO 2-1 was effectively metabolized by fecal bacteria to produce lactate and short chain fatty acids, especially acetate and butyrate. The specific metabolic pathways of MLO 2-1 by gut microbiota were further illuminated. Gut microbiota analysis revealed that MLO 2-1 selectively promoted the growth of Ligilactobacillus murinus, a commensal bacterium presented a reduced level in T2DM mice. Animal experiments indicated that MLO 2-1 and L. murinus exhibited hypoglycemic activities. These results demonstrated that MLO 2-1 might alleviate T2DM by selectively accelerating the proliferation of L. murinus.

Antihypertensive effects of whey protein hydrolysate involve reshaping the gut microbiome in spontaneously hypertension rats

Novel angiotensin-converting enzyme (ACE) inhibitory peptides were identified from whey protein hydrolysates (WPH) in vitro in our previous study and the antihypertensive abilities of WPH in vivo were further investigated in the current study. Results indicated that WPH significantly inhibited the development of high blood pressure and tissue injuries caused by hypertension. WPH inhibited ACE activity (20.81 %, P < 0.01), and reduced renin concentration (P < 0.05), thereby reducing systolic blood pressure (SBP) (12.63 %, P < 0.05) in spontaneously hypertensive rats. The increased Akkermansia, Bacteroides, and Lactobacillus abundance promoted high short chain fatty acid content in feces after WPH intervention. These changes jointly contributed to low blood pressure. The heart weight and cardiomyocyte injuries (hypertrophy and degeneration) were alleviated by WPH. The proteomic results revealed that 19 protein expressions in the heart mainly associated with the wingless/integrated (Wnt) signaling pathway and Apelin signaling pathway were altered after WPH supplementation. Notably, WPH alleviated serum oxidative stress, indicated by the decreased malondialdehyde content (P < 0.01), enhanced total antioxidant capacity (P < 0.01) and superoxide dismutase activity (P < 0.01). The current study suggests that WPH exhibit promising antihypertensive abilities in vivo and could be a potential alternative for antihypertensive dietary supplements.

Lactobacillus plantarum J26 alleviates alcohol-induced oxidative liver injury by regulating the Nrf2 signaling pathway

Oxidative stress is one of the main ways to cause alcohol-induced liver injury, and alcoholic liver disease (ALD) has been a common health problem worldwide. Lactic acid bacteria (LAB) is also considered as a potential treatment to alleviate alcohol-induced liver injury. Lactobacillus plantarum J26 is a LAB isolated from Chinese traditional fermented dairy products with excellent probiotic effects. This study aimed to establish a mice model of alcoholic liver injury through acute-on-chronic alcohol feeding and to study the alleviating effect of pre-intake of L. plantarum J26 on alcohol-induced oxidative liver injury and focus on its potential mechanism of alleviating effect. The results showed that pre-intake of L. plantarum J26 could improve liver pathological changes, reduce lipid accumulation, increase mitochondrial ATP and mitochondrial (mtDNA) levels, and alleviate liver injury. In addition, pre-intake L. plantarum J26 can improve the level of short-chain fatty acids (SCFAs) in the intestines in mice, short chain fatty acids can be used as a signaling molecule activation of nuclear factor E2-related factor 2 (Nrf2) signaling pathway to alleviate liver oxidative stress, and maintain mitochondrial homeostasis by regulating the expression of genes related to mitochondrial dynamics and autophagy, thereby reducing cell apoptosis to alleviate alcohol-induced oxidative liver injury.

Studying Cation Exchange in {Cr7Co} Pseudorotaxanes: Preparatory Studies for Making Hybrid Molecular Machines.

In the design of dynamic supramolecular systems used in molecular machines, it is important to understand the binding preferences between the macrocycle and stations along the thread. Here, we apply 1H NMR spectroscopy to investigate the relative stabilities of a series of linear alkylammonium templated pseudorotaxanes with the general formula [H2NRR'][Cr7CoF8(O2CCH2 tBu)16] by exchanging the cation in solution. Our results show that the pseudorotaxanes are able to exchange threads via a dissociative mechanism. The position of equilibrium is dependent upon the ammonium cation and solvent used. Short chain primary ammonium cations are shown to be far less favourable macrocycle stations than secondary ammonium cations. Collision-induced dissociation mass spectrometry (CID-MS) has been used to look at disassembly of the pseudorotaxanes in a solvent-free environment and stability trends compared to those in acetone-d6. The energy needed to induce 50 % of the precursor ion loss (E50) is used and shows a similar trend to the equilibria measured by NMR. The relative stabilities of these hybrid inorganic-organic pseudo-rotaxanes are different to those of host-guest compounds involving crown ethers and this may be valuable for the design of molecular machines.

Development of a highly sensitive ampicillin sensor utilizing functionalized aptamers.

To develop a sensitive and simple ampicillin (AMP) sensor for trace antibiotic residue detection, the influencing factors of the modification effect of nanogold-functionalized nucleic acid sequences (Adenine: A, Thymine: T) were comprehensively analyzed in this study, including the modification method, base length and type. It was found that under the same base concentration, longer chains are more likely to reach saturation than shorter chains; and when the base concentration and length are both the same, A exhibits a higher saturation modification level compared to T. Based on these research findings, a highly sensitive fluorescence aptamer sensor for detecting ampicillin was constructed using the optimized functionalized sequence (ployA6-aptamer) and experimental conditions (6 hours binding time between nucleic acid aptamer and complementary strand, pH 7 working solution, 20 minutes detection time) based on the principle of fluorescence resonance energy transfer. The sensor has a detection range of 0.18 ng ml-1 to 3.11 ng ml-1 for ampicillin, with a detection limit of 0.04 ng ml-1. It exhibits significant selectivity and achieves an average recovery rate of 98.71% in tap water and 91.83% in milk. This method can be used not only for residual ampicillin detection, but also for highly sensitive detection of various antibiotics and small biological molecules by replacing the aptamer type. It provides a research basis for the design of highly sensitive fluorescence aptamer sensors and further applications of nanogold@DNA composite structures.

Enhanced perfluorooctanoic acid (PFOA) degradation by electrochemical activation of peroxydisulfate (PDS) during electrooxidation for water treatment

Improved treatment of per- and polyfluoroalkyl substances (PFAS) in water is critically important in light of the proposed United States Environmental Protection Agency (USEPA) drinking water regulations at ng L−1 levels. The addition of peroxymonosulfate (PMS) during electrooxidation (EO) can remove and destroy PFAS, but ng L−1 levels have not been tested, and PMS itself can be toxic. The objective of this research was to test peroxydisulfate (PDS, an alternative to PMS) activation by boron-doped diamond (BDD) electrodes for perfluorooctanoic acid (PFOA) degradation. The influence of PDS concentration, temperature, and environmental water matrix effects, and PFOA concentration on PDS-EO performance were systematically examined. Batch reactor experiments revealed that 99 % of PFOA was degraded and 69 % defluorination was achieved, confirming PFOA mineralization. Scavenging experiments implied that sulfate radicals (SO4–) and hydroxyl radicals (HO) played a more important role for PFOA degradation than 1O2 or electrons (e−). Further identification of PFOA degradation and transformation products by liquid chromatography-mass spectrometry (LC-MS) analysis established plausible PFOA degradation pathways. The analysis corroborates that direct electron transfers at the electrode initiate PFOA oxidation and SO4– improves overall treatment by cleaving the CC bond between the C7F15 and COOH moieties in PFOA, leading to possible products such as C7F15 and F−. The perfluoroalkyl radicals can be oxidized by SO4– and HO, resulting in the formation of shorter chain perfluorocarboxylic acids (e.g., perfluorobutanoic acid [PFBA]), with eventual mineralization to CO2 and F−. At an environmentally relevant low initial concentration of 100 ng L−1 PFOA, 99 % degradation was achieved. The degradation of PFOA was slightly affected by the water matrix as less removal was observed in an environmental river water sample (91 %) compared to tests conducted in Milli-Q water (99 %). Overall, EO with PDS provided a destructive approach for the elimination of PFOA.

Removable PDMS Films with Ultra‐Low AgNPs Content and Effective SERS Effect by N‐Octylamine Transfer and Immersion Deposition

AbstractThe short alkyl chain of N‐octylamine was demonstrated to be able to transfer silver nanoparticles (AgNPs) from the aqueous to toluene phase with a narrow average size lower than 10 nm via ligand exchange between N‐octylamine and the sodium citrate used as a reducing and stabilizing agent during AgNPs synthesis. Surface plasmon analysis by UV‐visible spectroscopy showed that the N‐octylamine concentration significantly influences the concentration and stability of AgNPs transferred to the toluene phase and the time required for such transfer. Then, the transferred silver nanoparticles were deposited on a polydimethylsiloxane (PDMS) substrate by drop‐casting (PDMS‐T‐50‐D) or immersion (PDMS‐T‐50‐I). XPS analysis demonstrated that the AgNPs are deposited at lower than 0.02 % atomic percentages through both deposition methods. The Raman signal and the noise by fluorescence signal were shown to be significantly influenced by the AgNPs deposition method on PDMS film. The trace content of AgNPs on the flexible PDMS films on both PDMS‐T‐50‐D and PDMS‐T‐50‐I substrates can eliminate the fluorescence signal of the analyte; however, only the PDMS‐T‐50‐I substrate demonstrated a remarkable SERS‐enhanced signal. These results could significantly contribute to the design of new flexible and removable SERS substrates with ultra‐low contents of noble metal NPs.

Safety and effects of acetylated and butyrylated high amylose maize starch in recently diagnosed youths with type 1 diabetes; a Pilot Study.

Acetylated and butyrylated high amylose starch (HAMS-AB) is a prebiotic shown to be effective in type 1 diabetes (T1D) prevention in mouse models and is safe in adults with established T1D. HAMS-AB alters the gut microbiome profile with increased bacterial fermenters that produce short chain fatty acids (SCFAs) with anti-inflammatory and immune-modulatory effects. We performed a pilot study using a cross-over design to assess the safety and efficacy of 4 weeks of oral HAMS-AB consumption by recently diagnosed (< 2 years of diagnosis) youths with T1D. Seven individuals completed the study. The mean±SD age was 15.0±1.2 years, diabetes duration 19.5±6.3 months, 5/7 were female and 4/7 were White, all with a BMI of < 85th%. The prebiotic was safe. Following prebiotic intake, gut microbiome changes were seen, including a notable increase in the relative abundance of fermenters such as Bifidobacterium and Faecalibacterium. Treatment was also associated with changes in bacterial functional pathways associated with either improved energy metabolism (upregulation of tyrosine metabolism) or anti-inflammatory effects (reduced geraniol degradation). There were no differences in stool SCFA levels. Plasma metabolites associated with improved glycemia, such as hippurate, were significantly increased after treatment and there were positive and significant changes in the immune regulatory function of mucosal associated invariant T cells. There was a significant decrease in the area under the curve glucose but not C-peptide, as measured during a mixed meal tolerance testing, following the prebiotic consumption. In summary, the prebiotic HAMS-AB was safe in adolescents with T1D and showed promising effects on the gut microbiome composition, function and immune regulatory function.

Characteristics of rumen microbiota and Prevotella isolates found in high propionate and low methane-producing dairy cows.

Ruminal methane production is the main sink for metabolic hydrogen generated during rumen fermentation, and is a major contributor to greenhouse gas (GHG) emission. Individual ruminants exhibit varying methane production efficiency; therefore, understanding the microbial characteristics of low-methane-emitting animals could offer opportunities for mitigating enteric methane. Here, we investigated the association between rumen fermentation and rumen microbiota, focusing on methane production, and elucidated the physiological characteristics of bacteria found in low methane-producing cows. Thirteen Holstein cows in the late lactation stage were fed a corn silage-based total mixed ration (TMR), and feed digestion, milk production, rumen fermentation products, methane production, and rumen microbial composition were examined. Cows were classified into two ruminal fermentation groups using Principal component analysis: low and high methane-producing cows (36.9 vs. 43.2 L/DMI digested) with different ruminal short chain fatty acid ratio [(C2+C4)/C3] (3.54 vs. 5.03) and dry matter (DM) digestibility (67.7% vs. 65.3%). However, there were no significant differences in dry matter intake (DMI) and milk production between both groups. Additionally, there were differences in the abundance of OTUs assigned to uncultured Prevotella sp., Succinivibrio, and other 12 bacterial phylotypes between both groups. Specifically, a previously uncultured novel Prevotella sp. with lactate-producing phenotype was detected, with higher abundance in low methane-producing cows. These findings provide evidence that Prevotella may be associated with low methane and high propionate production. However, further research is required to improve the understanding of microbial relationships and metabolic processes involved in the mitigation of enteric methane.

Archaea influence composition of endoscopically visible ileocolonic biofilms

ABSTRACT The gut microbiota has been implicated as a driver of irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD). Recently we described, mucosal biofilms, signifying alterations in microbiota composition and bile acid (BA) metabolism in IBS and ulcerative colitis (UC). Luminal oxygen concentration is a key factor in the gastrointestinal (GI) ecosystem and might be increased in IBS and UC. Here we analyzed the role of archaea as a marker for hypoxia in mucosal biofilms and GI homeostasis. The effects of archaea on microbiome composition and metabolites were analyzed via amplicon sequencing and untargeted metabolomics in 154 stool samples of IBS-, UC-patients and controls. Mucosal biofilms were collected in a subset of patients and examined for their bacterial, fungal and archaeal composition. Absence of archaea, specifically Methanobrevibacter, correlated with disrupted GI homeostasis including decreased microbial diversity, overgrowth of facultative anaerobes and conjugated secondary BA. IBS-D/-M was associated with absence of archaea. Presence of Methanobrevibacter correlated with Oscillospiraceae and epithelial short chain fatty acid metabolism and decreased levels of Ruminococcus gnavus. Absence of fecal Methanobrevibacter may indicate a less hypoxic GI environment, reduced fatty acid oxidation, overgrowth of facultative anaerobes and disrupted BA deconjugation. Archaea and Ruminococcus gnavus could distinguish distinct subtypes of mucosal biofilms. Further research on the connection between archaea, mucosal biofilms and small intestinal bacterial overgrowth should be performed.

A recombinant amylomaltase from Thermus thermophilus STB20 can tailor the macromolecular characteristics of tapioca starch through its transglycosylation activity

Amylomaltase (AM) is a transglucosylase known for producing glucans exclusively with α-1,4 linkages, which is widely used in the industries for modification of starch. In this paper, a study was conducted to investigate both the characteristics of recombinant amylomaltase from Thermus thermophilus STB20 (TtAM) and its impact on the fine structure of tapioca starch. The TtAM showed an excellent thermostability and a high affinity for larger molecular substrates. Changes in the molecular characteristics of tapioca starch were discussed in terms of chain length distribution (CLD) and molecular weight distribution (Mw) under different enzyme dosages and reaction times. The TtAM degraded amylose, which was transferred to short side chains (DP 11-26) of amylopectin, thereby extending short side chains into longer chains (DP >26). The Mw of TtAM-treated starches initially increased and then decreased. With increasing enzyme dosage and reaction time, the TtAM facilitated hydrolysis activities, reducing the proportion of long side chains, which led to increase the dextrose equivalent (DE) value. Cycloamylose (DP 8 - 33) was generated during the modification process, reflecting a diversified range of the enzyme products, and resulting in a polymodal distribution profile in the Mw. These findings potentially broaden the utilization of TtAM in the production of starch conversion products, indicating that novel starch-based derivatives with tailor-made structures can be obtained by controlling the enzyme dosages and reaction times.

Machine learning approach with a posteriori-based feature to predict service life of a thermal cracking furnace with coking deposition

A thermal cracking furnace is an important equipment in the petrochemical industry that is typically used for breaking long hydrocarbons into short chains and producing coke as a byproduct. Deposition of the generated coke increases the temperature at the outside coil wall, necessitating regular furnace maintenance to prevent coil failure. Therefore, this study proposed a machine learning approach with a posteriori-based feature to predict the service life of the furnace to runtime failure. The proposed approach consists of a two-level machine learning model, which aims to improve prediction accuracy and reduce feature sensitivity. The label is classified as a week-range label, which can be categorized by classification criteria into three classes: weekly, bi-weekly, and quarter-weekly. The first-level model is utilized to extract sensor features into the posterior probability class label score. These scores are then processed and sorted into moving windows to generate features for the second-level model. The results showed that the proposed model could extract process variation and identify service needs, which improved classification accuracy by 23.94 % and 17.67 % for the clean and coke-contaminated datasets compared to the conventional classification model, respectively. Additionally, the most general class range (quarter-weekly) provided the best performance compared to the bi-weekly and weekly classes. Therefore, the model has the potential for the prediction of the furnace service life under pseudo-steady state conditions, where coking evolves gradually over time.

Bayesian Analysis of Exponential Random Graph Models Using Stochastic Gradient Markov Chain Monte Carlo

The exponential random graph model (ERGM) is a popular model for social networks, which is known to have an intractable likelihood function. Sampling from the posterior for such a model is a long-standing problem in statistical research. We analyze the performance of the stochastic gradient Langevin dynamics (SGLD) algorithm (also known as noisy Longevin Monte Carlo) in tackling this problem, where the stochastic gradient is calculated via running a short Markov chain (the so-called inner Markov chain in this paper) at each iteration. We show that if the model size grows with the network size slowly enough, then SGLD converges to the true posterior in 2-Wasserstein distance as the network size and iteration number become large regardless of the length of the inner Markov chain performed at each iteration. Our study provides a scalable algorithm for analyzing large-scale social networks with possibly high-dimensional ERGMs.

Roles of oxygen in methane oxidation coupled denitrification in membrane biofilm reactors

With a focus on efficient and low-carbon wastewater treatment, methane driven denitrification has garnered significant attention. Membrane biofilm reactors (MBfRs) are commonly employed to enhance methane utilization. However, previous studies have identified the impact of unavoidable oxygen infiltration on reactor performances without specifying the critical oxygen threshold. In this study, two parallel CH4-MBfRs with different oxygen intakes were established for mutual control. Three different oxygen concentrations, namely 4.5 ± 0.4 mg/L, 1.7 ± 0.2 mg/L, and 0.1 ± 0.1 mg/L, were defined as Rich, Limited, and Poor-oxygen condition, respectively. Results revealed that the maximum denitrification rate in CH4-MBfRs occurred under Limited-oxygen condition (220 mg N/L/d), followed by Poor-oxygen (108.1 mg N/L/d) and Rich-oxygen (60.0 mg N/L/d) conditions. Notably, methane driven denitrification consistently resulted in short chain fatty acids (SCFAs) production. The maximum SCFAs accumulation of 664.5 mg/L was also observed under Limited-oxygen condition. Microbial community characterization showed that the biofilm was predominated by Pseudomonas, Paracoccus, Lentimicrobium, Arcanobacterium, and Proteiniphilum. Based on the known metabolism characteristics of these microorganisms, it was assumed that these denitrifiers and SCFAs producers contributed jointly to methane driven denitrification, potentially triggered by oxygen. The findings contribute to understanding the role of oxygen in methane oxidation-coupled denitrification.

Interfacial kinetics reveal enzymatic resistance mechanisms behind granular starch with smooth surfaces

Heterogeneous (interfacial) enzyme catalyzed hydrolysis of starch granules occurs in various biological systems, including plants, animal/human digestion, and microorganisms. Factors such as granular size, surface area, pores, and smoothness play crucial roles in influencing this process. However, limited understanding persists regarding the high enzymatic resistance of starch granules with smooth surfaces. In this study, we investigated the hydrolysis mechanism of glucoamylase (GA) on three different types of starch granules with smooth surfaces, extracted from Curcuma zedoaria (zedoary) rhizomes, Solanum tuberosum (potato) tubers, and Manihot esculenta (tapioca or cassava) roots. We compared the Langmuir adsorption, interfacial kinetics, and the multi-level structure of the three starches. Our data demonstrate that the lower enzymatic resistance observed in tapioca starch stems from the higher density of enzymatic attack sites (kinΓmax) recognized by GA on tapioca starch (1.0 nmol/g) compared to potato (0.6 nmol/g) and zedoary (0.3 nmol/g) starch granules. The high kinΓmax for tapioca starch was significantly influenced by its relatively lower B-type crystallinity, which is disrupted by the presence of short fa chains (degree of polymerization (DP) < 12) and long amylose chains. Furthermore, the relatively higher proportion of longer chains (fb1 and fb2 chains) on the surface of tapioca starch also contributed to higher kinΓmax for GA, resulting in lower enzymatic resistance. These findings enhance our understanding of how the structure of starch granules affects enzymatic catalysis, particularly in granular starches with smooth surfaces devoid of pores. Such insights are crucial for elucidating the digestion and utilization of starch granules.

Legacy and emerging per- and polyfluoroalkyl substances (PFASs) in agricultural soils affected by fluorochemical manufacturing facilities, North China: Occurrence, region-specific distribution, substitution trend and source appointment

Accompanied with restriction of legacy per- and polyfluoroalkyl substances (PFASs), numbers of emerging PFASs are widely detected in the environment. However, information on environmental occurrences and behaviors of emerging PFASs were scarce in agricultural soils. In this study, the spatial distributions, sources, substitution trends and ecological risk assessment of 31 legacy and emerging PFASs were investigated in 69 agricultural soils from Fuxin, North China. The 26 out of 31 PFASs were detected with concentrations of 57.36 - 1271.06 pg/g dry weight. Perfluorooctanoic acid (PFOA) and hexafluoropropylene oxide dimer acid (HFPO-DA) were predominant in legacy and emerging PFASs, respectively. Based on principal component and dual carbon-nitrogen stable isotope analysis, atmosphere, fluorochemical activities and river irrigation were main sources of PFASs. Substitution trends indicated HFPO-DA and short chain perfluoroalkyl carboxylic acids (C4 - C7) as main alternatives of PFOA, and 6:2 fluorotelomer sulfonic acid (6:2 FTSA) and sodium p-perfluorous nonenoxybenzene sulfonate (OBS) as major substitutes to perfluorooctanesulfonic acid (PFOS). The calculated risk quotient values (< 0.006) only indicated potential low ecological risk of 7 target PFASs in agricultural soils. The results of this study broadened out the information of PFAS contamination in agricultural soils, which were significant for PFAS supervision in China.

Microplastics and nanoplastics released from injection syringe, solid and liquid dimethylpolysiloxane (PDMS)

For a plastic syringe, a stopper at the end of plunger is usually made of polydimethylsiloxane (PDMS, and co-ingredients). To reduce friction and prevent leakage between the stopper and barrel, short chain polymer of liquid PDMS is also used as lubricant. Consequently, an injection process can release solid PDMS debris from the stopper and barrel, and liquid PDMS droplets from the lubricant, both of which are confirmed herein as solid and liquid micro(nano)plastics. From molecular spectrum perspective to directly visualise those micro(nano)plastics, Raman imaging was employed to analyse hundreds-to-thousands of spectra (hyper spectrum or hyperspectral matrix) and significantly enhance signal-to-noise ratio. From morphology perspective to provide high resolution of image, scanning electron microscopy (SEM) was engaged to cross-check with Raman images and increase assignment / quantification certainty. The weak Raman imaging signal of nanoplastics was extracted using image deconvolution algorithm to remove the background noise and average the signal variation. To increase the result’s representativeness and avoid quantification bias, multiple syringes were tested and multiple areas were randomly scanned toward statistical results. It was estimated that thousands of microplastics and millions of nanoplastics of solid/liquid PDMS might be injected when using a plastic syringe of 1 mL. Overall, Raman imaging (along with algorithm and SEM) can be helpful for further research on micro(nano)plastics, and it should be cautious to use plastic syringe due to the increasing concern on the emerging contamination of not only solid but also liquid micro(nano)plastics.

Thermodynamics of a confined macromolecule: An analytical approach

We consider a fully directed self-avoiding walk model on a cubic lattice to mimic the conformations of an infinitely long flexible polymer chain and also to mimic confirmations of a short flexible chain under confined conditions. The confinement conditions is achieved using two parallel impenetrable plates. The confined chain is under good solvent conditions and we revisit this problem to solve the real (self avoiding) polymer's model for any length of the chain and also for any given separation in between the confining plates. The equilibrium statistics of the confined polymer chain are derived using analytical approach of the generating function technique. The force of the confinement, the surface tension and the monomer density profile of the confined chain are obtained analytically. We propose that the methods of calculation are suitable to understand thermodynamics of an arbitrary length confined polymer chain under other possible conditions of the confinement.

Vertical Haloponics: Sustainable and Resilient Productions Using Brackish Water

While the rapidly growing global population will require a significant increase in food production in the next years, the current climate, sanitary and geopolitical crises highlight the weaknesses of the actual food production systems, excessively dependent on external inputs and involving extremely complex nested scales and non-linear processes. Thus, appears clearly the need of accelerating the transition toward agricultural solutions and food systems based on the principles of the “Green Deal”, encompassing ecological resilience, environmental sustainability, local production, and universal access to healthy foods. Aquaponics (AP) can provide short and eco-friendly food supply chains with increased resource-use efficiency, high environmental sustainability, and food resilience. The sustainability of AP systems could be further increased by exploiting water resources that are not suitable for other purposes (brackish and salt water - haloponics), applying the vertical farming technology for both aquatic and vegetable species, reducing the use of fish meal in aquafeeds, valorizing the system residues (sludge) for agronomic purposes.The VERTICHALPONICS project aims to develop an innovative food production system by implementing an interdisciplinary approach. Since aquaponics combines recirculation aquaculture and hydroponics, within a close loop, it is considered environment friendly. However, given the different technical approaches, it is necessary to evaluate the differences in impacts and specially to assess whether the vertical system is really resource-efficient and economically viable for farmers, in comparison to the business-as-usual. The environmental and economic sustainability of the system is measured by the mean of a combined LCA and the LCC analysis (EN ISO 14040-44 and ISO 15686-5:2017 standards). The system expansion will be used to evaluate the beneficial effect of reducing the overall environmental burden from by-product recovery and utilization of side wastes, specifically the sludge produced. The method applied are Recipe and IPCC 2013 Global Warming Potential 100a. Environmental impact indicators will be provided using both mid-point and end-point categories thank to the Recipe Method, while the IPCC 2013 Global Warming Potential 100a will be applied to calculate the direct global warming potential of the system. Moreover, the inclusion of the agronomic valorization of the sludge will be analyzed to understand the potential in terms of avoided impacts.