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The Malpighian Tubules (MTs) are the main excretory organs in most insects. They play a key role in the production of primary urine and osmoregulation, selectively reabsorbing water, ions, and solutes. Besides these functions conserved in most insects, MTs can serve some specialized tasks at different stages of some species’ development. The specialized functions include the synthesis of mucopolysaccharides and proteins for the building of foam nests, mucofibrils for the construction of dwelling tubes, adhesive secretions to help the locomotion, and brochosomes for protection as well as the usage of inorganic salts to harden the puparia, eggs chorion, and pupal cells’ closing lids. MTs are also the organs responsible for the astonishing bioluminescence of some Diptera glowworms and can go through some drastic histological changes to produce a silk-like fiber utilized to spin cocoons. The specialized functions are associated with modifications of cells within the entire tubules, in specific segments, or, more rarely, modified secretory cells scattered along the MTs. In this review, we attempted to summarize the observations and experiments made over more than a century concerning the non-excretive functions of insects’ MTs, underlying the need for new investigations supported by the current, advanced technologies available to validate outdated theories and clarify some dubious aspects.

In order to study the effect of near-neutral inorganic salts on the thermal decomposition of nitrocellulose, we chose K₂SO₄ as the research object and explored the changes of TG/DSC curves of the samples under different atmospheres by synchronous analyzer. The apparent activation energy values of the samples were calculated by multi iso-conversional methods, including Kissinger–Akahira–Sunose, Flynn–Wall–Ozawa, Friedman, Tang, modified Coats–Redfern and advanced Vyazovkin method. It was found that the activation energy of the samples was more stable between the conversion rates of 0.04–0.74. Subsequently, the main reaction zone of the samples was modeled by the TAS method, while the whole reaction process of the samples was analyzed by the probable model, the Malek method. It was found that the model of the main reaction zone was Avrami–Erofeev model, while the most probable model of thermal degradation was obtained as Sestak–Berggren model. Subsequently, a reconstruction of the reaction mechanism model was undertaken based on the experimental values of the reaction mechanism function at different heating rates. The resulting model was found to be more effective in describing the real reaction process. As a result of this study, there are certain guiding principles that can be applied to the pyrolysis reaction model and to the actual production process of nitrocellulose.

The effect of lithium chloride (LiCl) on the dose–response performance of the N-(3-methoxypropyl)acrylamide polymer-gel dosimeter (NMPAGAT) was studied for 3-D dose measurements. The NMPAGAT-LiCl dosimeters were irradiated for various doses using a 6 MV medical linear accelerator. A 0.5 Tesla nuclear magnetic resonance (NMR) instrument was used to scan the signal development of the irradiated dosimeters in terms of the spin–spin relaxation rate (R2 = 1/T2) of hydrogen protons within the water molecule. The results show that the R2 dose–response of NMPAGAT-LiCl gels improved with increasing the concentration of LiCl. The R2 sensitivity of dosimeter with a concentration of 1000 mM LiCl was 4 times higher than the same gel without LiCl in the range dose–response of 0–4 Gy. In addition, no significant effects were introduced to the LiCl gel formulation by varying the dose rate and photon energy. R2 of the gel dosimeter was not affected by changing irradiation temperature in the range of 15–25 °C. The dose–response decreased with increasing scanning temperature and was stable for up to 4 days after irradiation.

The effects of pH, inorganic ion concentration, and dephosphorylation by hydrolysis on the transparency and viscosity of phosphorylated cellulose nanofibers (P-CNF) with different phosphate group contents and degrees of fibrillation were studied in order to boost its use as a rheology modifier. From the neutralization titration curve of P-CNF dispersions, acidity values of pKa1 = 3.1 and pKa2 = 8.3 were determined. These values were almost constant regardless of the amount of phosphate groups. The P-CNF dispersion maintained high transparency and viscosity in the pH range of 3–11 owing to a wide range of acidity values and the buffer capacity of the phosphate group. The viscosity of P-CNF dispersions was influenced by the amount of phosphate groups and the degree of fibrillation, which also affected the viscosity behavior of the dispersion when inorganic salts were added. The long-term storage stability of phosphate groups introduced on P-CNF was also examined by accelerated (heating) test. The hydrolysis reaction of P-CNFs took several days to reduce the phosphorous content to one-tenth of the initial content at 80 °C. Kinetic analysis showed that dephosphorylation proceeded as a first order reaction, as found for other phosphorylated esters. As dephosphorylation proceeded, the transparency and viscosity of the P-CNF dispersion decreased because P-CNFs tended to aggregate through hydrogen bonding, which also seemed to suppress dephosphorylation. Furthermore, the activation energy of deesterification obtained was 130.0 kJ/mol. The decrease in the ratio of phosphate groups was highest when the degree of anion neutralization of the phosphate groups was 50%.

Inorganic salt pretreatment of lignocellulosic biomass has proven to be an efficient way to increase the efficiency of enzymatic saccharification. However, it is not clear that this improvement is the result of modification of the lignocellulosic substrate after pretreatment, or removal of inhibitor, or enhancement of cellulase or a combination of these events. Therefore, this study aimed to analyze the effects of inorganic salts on kinetics of cellulase enzymes (celluclast 1.5L and accellerase 1500). Two substrates rich in cellulose content [carboxymethylcellulose (CMC), avicel (AV)] and lignocellulose substrate [sugarcane bagasse (SB)] were considered. The enzymatic saccharification was carried with and without the addition of inorganic salts (NaCl and KCl) at 0.5 M and 1.0 M concentration. The kinetic parameters, K m and V m , were determined to mechanically understand the pattern of inhibition and enhancement of inorganic salts on enzymatic saccharification. The kinetics parameters of celluclast 1.5L and accellerase 1500 for hydrolysis of CMC and AV with NaCl showed uncompetitive inhibition. Whereas, influences of KCl on both cellulase were differentiated to function in inhibition or enhancement modes when challenged with different substrates. On the other hand, enzymatic hydrolysis efficiencies of SB using both cellulases were enhanced under addition of NaCl and KCl, by increasing V m of celluclast 1.5L from 0.303 to 0.635 mg/mL min (0.5 M KCl) and accellerase 1500 from 0.383 to 0.719 mg/mL min (1.0 M NaCl). The details of kinetic analysis in this work revealed the mechanism of inorganic salts on cellulase kinetics to be involved in substrate modification and removal of inhibitor. Graphic abstract

The microalgae industry shows a promising future in the production of high-value products such as pigments, phycoerythrin, polyunsaturated fatty acids, and polysaccharides. It was found that polysaccharides have high biomedical value (such as antiviral, antibacterial, antitumor, antioxidative) and industrial application prospects (such as antioxidants). This study aimed to improve the polysaccharides accumulation of Porphyridium purpureum CoE1, which was effectuated by inorganic salt starvation strategy whilst supplying rich carbon dioxide. At a culturing temperature of 25 °C, the highest polysaccharide content (2.89 g/L) was achieved in 50% artificial seawater on the 12th day. This accounted for approximately 37.29% of the dry biomass, signifying a 25.3% increase in polysaccharide production compared to the culture in 100% artificial seawater. Subsequently, separation, purification and characterization of polysaccharides produced were conducted. Furthermore, the assessment of CO2 fixation capacity during the cultivation of P. purpureum CoE1 was conducted in a 10 L photobioreactor. This indicated that the strain exhibited an excellent CO2 fixation capacity of 1.66 g CO2/g biomass/d. This study proposed an efficient and feasible approach that not only increasing the yield of polysaccharides by P. purpureum CoE1, but also fixing CO2 with a high rate, which showed great potential in the microalgae industry and Bio-Energy with Carbon Capture and Storage.

This work aims to investigate the interfacial tension characteristics of alkyl carboxymethyl betaines dispersed at the crude oil/formation water interface. Four alkyl dimethyl carboxymethyl betaines and one alkyl diethyl carboxymethyl betaine were synthesized, then the effects of surfactant molecular structure, crude oil component, and inorganic salt composition of formation water on interfacial tensions were studied systematically. The results show that the synthesized octadecyl diethyl carboxymethyl betaine has the highest interfacial activity and exhibits superior anti-dilution performance. In the presence of polyacrylamide, this betaine also displays good anti-adsorption capability. With respect to crude oil components, the resin component, especially the petroleum acid and alkali components, play important roles in tension reduction. For formation water, its alkaline inorganic salts are crucial to obtain an ultra-low interfacial tension by its saponification effect on petroleum acid. The octadecyl diethyl carboxymethyl betaine also exhibits good temperature and salt resistance, but poor tolerance toward divalent cations owing to the consumption of alkaline inorganic salts. Moreover, it is found that there exists synergism between octadecyl diethyl carboxymethyl betaine and dodecylbenzene sulfonate which can further reduce the interfacial tension. The above findings are conducive to the selection of betaine surfactants in chemical flooding.

Carbon dots (CDs) have been widely adopted as optical materials because of their excellent luminescent properties. However, most of the reported synthetic methods are conducted in solvents, especially hydrothermal/solvothermal reactions, leading to intractable problems such as toxic and flammable solvents, complex and inseparable by-products, and dangerously high pressures and temperatures. Solid-phase synthesis of CDs in air is an effective solution to overcome the above issues, but solid reactions always result in uncontrolled growth and agglomeration of nanoparticles. In this study, some inorganic salts are selected as catalysts for synthesizing CDs in solid states and air, which also play as dispersants to hinder CDs aggregation. In the meantime, some aromatic derivatives containing hydroxyl and amino groups are chosen as carbon sources, ground with the optimized catalyst, and then heated together in air. The production yields are affected by the reaction time and reactant ratio, while the graphitization degrees of the CDs are determined by the reaction temperature. The I G / I D value of their Raman spectra increases from 0.59 to 0.85, and the particle size decreases from 2.5 to 1.4 nm when the synthesis temperature is increased from 200 to 280 °C. The as-prepared CDs show emission peaks ranging from 366 to 606 nm, with the photoluminescence (PL) quantum yield up to 53%. Their emission color variation mainly results from different carbon sources, which can be ascribed to the differences in the element composition, functional groups, and graphitic nitrogen content of these CDs. By dispersing CDs of different concentrations into polyvinyl alcohol (PVA) and combining them with blue LEDs, cold, standard, and warm white light emitting devices (WLEDs) are prepared, with a color rendering index (CRI) up to 84. Since the as-prepared CDs have antioxidant ability at high temperature, the as-prepared WLEDs have long lifespans, remaining the effective white luminescence after 72 h continuous work.

This work screened out the optimal conditions for pretreatment of natural lignocellulose with inorganic salts and provided a simple, easy-to-operate, low-cost, clean and efficient pretreatment method for the efficient degradation of natural lignocellulose by strains. The results showed that the optimal pretreatment inorganic salt was FeCl2 with a concentration of 11%, pretreatment at 60 °C for 48 h, and the solid–liquid ratio was 1:11 (g/mL). According to the characterization results, after pretreatment of FeCl2 solution, the smooth and dense structure of natural lignocellulose surface became rough and irregular, and surface fiber bundles showed spalling and fracture. Subsequently, the enzymes produced by solid-state fermentation of Aspergillus fumigatus were easier to enter the interior, which increased the contact area between materials and enzymes, and increased the amount of enzymatic loads, thereby improving the biodegradation effect.

In order to study the effect of inorganic salt additives on the surface tension of a sodium dodecylbenzene sulfonate (SDBS) solution, the surface tension of the mixed system of six common inorganic salt additives, NaCl, CaCl2, AlCl3, Na2SO4, Na2CO3, and NaHCO3, and SDBS was measured, and the effects of the inorganic salt types, surfactant concentrations and inorganic salt concentrations on the surface tension of the SDBS solution were studied. On this basis, three inorganic salts, NaCl, CaCl2 and Na2SO4, were selected, and their effects on the critical micelle concentration (CMC) of the SDBS solution were studied. The experimental results showed that different inorganic salts had different effects on the surface tension of the SDBS solution. The order of effect of the six inorganic salts on the surface tension of the SDBS solution was CaCl2 > NaCl > Na2SO4 > NaHCO3 > Na2CO3 > AlCl3; when the mass fraction of the SDBS solution is high, the influence of the inorganic salts on the surface tension of the SDBS solution is relatively small; with an increase in the concentration of the preferred inorganic salt additives, the surface tension of the SDBS solution decreases first, then tends to be stable, and then increases; a reduction in the critical micelle concentration by the three selected inorganic salt additives shows the trend of 0.7% NaCl > 0.5% CaCl2 > 0.5% Na2SO4.