Agar Solution Research Articles

Nitrite manipulation in water by structure change of plasma electrolysis reactor

In this study, experimental reactors for cathodic nitrogen plasma electrolysis were designed by the composition of galvanic (voltaic) and electrolytic cells with wide and narrow connectors filled with tap water and agar solutions. The designed reactor can be used to simultaneously perform and manage nitrification in acidic and alkaline environments. According to the reactor’s performance, it can be installed on the irrigation system and used depending on the soil pH of the fields for delivering water and nitrogen species that are effective in growth. The nitrification process was investigated by choosing the optimal reactor with a wide connector based on different changes in oxidation-reduction potential and pH on the anode and cathode sides. The nitrite concentration changed directly with ammonium and nitrate concentrations on the cathode side. It changed inversely and directly with ammonium and nitrate concentrations on the anode side respectively. Nitrite concentration decreased from 5.387 ppm with water connector, to 0.326 ppm with 20% agar solution, and 0.314 ppm with 30% agar solution connectors on the anode side. It increased from 0 ppm to 0.191 ppm with a water connector, 0.405 ppm with 20% agar solution, and 7.454 ppm with 30% agar solution connectors on the cathode side.

MORPHOLOGY AND HYDROPHOBICITY OF AGAR, BEESWAX, AND AGAR-BEESWAX EMULSION COATED ON POROUS ALUMINA SUPPORT

Membrane degassing technology is based on the principle of hydrophobicity. Up-to-date, the membrane degasifier is industrially produced by extrusion and then stretched to form a hollow fiber shape with long narrow pores along membrane length. Typical degasifiers are engineered with polypropylene (PP) due to its high toughness and flexibility. However, finding environmentally safe materials at a low cost for replacement for PP would be worth investigating. In this work, agar, beeswax, and their emulsion were coated on a tubular alumina membrane for use as a selective layer of the membrane degasifier. The agar solution with different concentrations between 1 and 4 wt% was coated on the alumina membrane support to create a pore network. Beeswax was coated on agar film to enhance the hydrophobicity. SEM images showed that the increase in the concentrations of agar led to a decreased pore size of the selective layer. Moreover, the contact angle increased up to 100° when the concentration of agar solution increased to 4 wt%. The increase in contact angle to 120° was obtained when the beeswax was coated, appropriate for hydrophobic applications.

Effect of NaCl, CaCl2, and sucrose on the rheological properties of agar from Gracilaria in Vietnam

Agar is a polysaccharide extracted mainly from Gracilaria. Agar is widely used in the food industry as a viscous agent, thickness, emulsifier or food stabiliser. The presence of NaCl, CaCl2 or sucrose influences in sol-gel transition, viscosity of the agar solution or gel strength of the agar. Agar forms a gel at high concentration or lower one if there is the presence of NaCl, CaCl2 or sucrose. Gelling temperature (Tg) of agar solution at 0.2 wt% increasing at 36, 36 or 38°C upon addition of 300 mM NaCl, 100 mM CaCl2, or 30% sucrose, respectively. The viscosity of the 0.2% agar solution increased insignificantly when the ionic strength was below 100 mM, but increased sharply above 100 mM. The gel strength increases with added NaCl, CaCl2 up to 100 mM, 30 mM, respectively; then they drop slightly at higher concentrations of NaCl, CaCl2. Meanwhile, the viscosity of agar solution only increases at sucrose concentrations above 10%. Gel strength increased with increasing sucrose concentration, being 1.2 to 1.8 times higher if 30% sucrose was added.

Effect of Homogenized Callus Tissue on the Rheological and Mechanical Properties of 3D-Printed Food.

The aim of the study was to develop ink enriched with a high content of lupine callus tissue (CT) suitable for 3D printing. Printable ink obtained using mashed potatoes (20 g/100 mL) and a 3% agar solution was used as the parent CT-free ink (CT0). Viscosity increased from 9.6 to 75.4 kPa·s during the cooling of the CT0 ink from 50 to 20 °C, while the viscosity of the ink with 80 g/100 mL of CT (CT80) increased from 0.9 to 5.6 kPa·s under the same conditions. The inclusion of CT was shown to decrease the hardness of 3D-printed food gel from 0.32 ± 0.03 to 0.21 ± 0.03 N. The storage modulus G' value was 7.9 times lower in CT80 samples than in CT0 samples. The values of fracture stress for CT80 and CT0 inks were 1621 ± 711 and 13,241 ± 2329 Pa, respectively. The loss tangent and the limiting strain did not differ in CT0 and CT80, although the value of the fracture strain was 1.6 times higher in the latter. Thus, the present study demonstrates that CT may be added to printing ink in order to enhance food with plant cell material and enable the 3D printing of specially shaped foods.

Spatial O2 Profile in Coix lacryma-jobi and Sorghum bicolor along the Gas Diffusion Pathway under Waterlogging Conditions.

While internal aeration in plants is critical for adaptation to waterlogging, there is a gap in understanding the differences in oxygen diffusion gradients from shoots to roots between hypoxia-tolerant and -sensitive species. This study aims to elucidate the differences in tissue oxygen concentration at various locations on the shoot and root between a hypoxia-tolerant species and a -sensitive species using a microneedle sensor that allows for spatial oxygen profiling. Job's tears, a hypoxia-tolerant species, and sorghum, a hypoxia-susceptible species, were tested. Plants aged 10 days were acclimated to a hypoxic agar solution for 12 days. Oxygen was profiled near the root tip, root base, root shoot junction, stem, and leaf. An anatomical analysis was also performed on the roots used for the O2 profile. The oxygen partial pressure (pO2) values at the root base and tip of sorghum were significantly lower than that of the root of Job's tears. At the base of the root of Job's tears, pO2 rapidly decreased from the root cortex to the surface, indicating a function to inhibit oxygen leakage. No significant differences in pO2 between the species were identified in the shoot part. The root cortex to stele ratio was significantly higher from the root tip to the base in Job's tears compared to sorghum. The pO2 gradient began to differ greatly at the root shoot junction and root base longitudinally, and between the cortex and stele radially, between Job's tears and sorghum. Differences in the root oxygen retention capacity and the cortex to stele ratio are considered to be related to differences in pO2.

Agar as a single organogelator in the process of solidification of rapeseed (canola) oil obtained by different manufacturing methods

The minimalistic solidified form of oil, herein called hydroleogel, was elaborated via the emulsion oleogelation method by using agar hydrogel, as sole oleogelator. The rapeseed oils, originating from different manufacturing processes, were used as oil phase. The texture and rheological characteristics, weight loss, oil binding capacity, as well as color and appearance once solidified and after 24 h and 48 h of storage were studied. Texture profile revealed the dual dependance – the hardest hydroleogels were formed with 3 % agar and using refined rapeseed (canola) oil showing 14.16 ± 0.28 N and 14.11 ± 0.45 N after 2 h and 48 h, respectively. In contrast, hydrogels formed with cold pressed oil and 3% agar solution had an average of 50% lower hardness compared to the others. The oil retention capacity of the matrix was highest for hydroleogels with 3 % agar and cold pressed oil (98.3 ± 1.4 %), followed by cold pressed and bleached oil (97.0 ± 1.8 %) and refined oil (95.77 ± 2.4 %). The largest weight losses were observed for hydroleogels based on 1 % agar, with the exception of those formed from refined oil where a sub-weight loss of 0.5 % was recorded after 48h. The brightest were hydroleogels with pressed and bleached oil and 1 % (w/w) agar having after 2h the L* parameter equal to 98.95 ± 0.01, while the darkest one was cold pressed and bleached oil with 3 % (w/w) of agar (83.15 ± 0.25). The concentration of agar and the type of rapeseed oils used strongly impacted the physicochemical parameters of agar-based hydroleogels. Rapeseed oil hydroleogels with agar as the only structuring agent - an oleogelator in the composition, are a unique combination of two phases being hydrogel (aqueous phase) and rapeseed oil (oil phase) with promising physicochemical parameters.

Silver Nanoparticle-Loaded Titanium-Based Metal-Organic Framework for Promoting Antibacterial Performance by Synergistic Chemical-Photodynamic Therapy.

The abuse of antibiotics leads to an increasing emergence of drug-resistant bacteria, which not only causes a waste of medical resources but also seriously endangers people's health and life safety. Therefore, it is highly desirable to develop an efficient antibacterial strategy to reduce the reliance on traditional antibiotics. Antibacterial photodynamic therapy (aPDT) is regarded as an intriguing antimicrobial method that is less likely to generate drug resistance, but its efficiency still needs to be further improved. Herein, a robust titanium-based metal-organic framework ACM-1 was adopted to support Ag nanoparticles (NPs) to obtain Ag NPs@ACM-1 for boosting antibacterial efficiency via synergistic chemical-photodynamic therapy. Apart from the intrinsic antibacterial nature, Ag NPs largely boost ROS production and thus improve aPDT efficacy. As a consequence, Ag NPs@ACM-1 shows excellent antibacterial activity under visible light illumination, and its minimum bactericidal concentrations (MBCs) against E. coli, S. aureus, and MRSA are as low as 39.1, 39.1, and 62.5 μg mL-1, respectively. Moreover, to expand the practicability of Ag NPs@ACM-1, two (a dense and a loose) Ag NPs@ACM-1 films were readily fabricated by simply dispersing Ag NPs@ACM-1 into heated aqueous solutions of edible agar and sequentially cooling through heating or freeze-drying, respectively. Notably, these two films are mechanically flexible and exhibit excellent antibacterial activities, and their antimicrobial performances can be well retained in their recyclable and remade films. As agar is nontoxic, degradable, inexpensive, and ecosustainable, the dense and loose Ag NPs@ACM-1 films are potent to serve as recyclable and degradable antibacterial plastics and antibacterial dressings, respectively.

Pollen Count Dynamics in Rapeseed Stamens in Early Spring

Abstract Pollen contains vegetative and generative cells that influence the seed set. Accurate pollen assessments help understand the breeding biology of oilseed rape. In order to evaluate the number of pollen grains in a large number of samples, an effective method should be designed. A new method was established to evaluate the pollen counts of five oilseed rape cultivars. This method mainly relies on 5% sucrose + 0.1% agar solution to suspend the pollen and uses a standard curve corresponding to the absorbance and the number of pollen grains to estimate the number of pollen grains. The linear fit formula of this standard curve was precision, and the R2 value between the pollen count and absorbance reached 0.998. Furthermore, the variation in the pollen counts at three flowering stages and on two kinds of stamens was assessed. The pollen count per flower varied significantly among oilseed rape cultivars and flowering stages (GLM: p<0.001). Moreover, the number of pollen grains on long-stamen anthers was significantly higher than that on short-stamen anthers (GLM: p<0.001). In conclusion, we established a rapid, accurate method for quantifying pollen grains based on absorbance determined in a liquid suspension by light spectroscopy, which is a feasible method. In addition, the number of pollen grains under different physiological conditions also provides basic data for oilseed rape breeding.

High-quality Agar and Polyacrylamide Tumor-mimicking Phantom Models for Magnetic Resonance-guided Focused Ultrasound Applications.

Tissue-mimicking phantoms (TMPs) have been used extensively in clinical and nonclinical settings to simulate the thermal effects of focus ultrasound (FUS) technology in real tissue or organs. With recent technological developments in the FUS technology and its monitoring/guided techniques such as ultrasound-guided FUS and magnetic resonance-guided FUS (MRgFUS) the need for TMPs are more important than ever to ensure the safety of the patients before being treated with FUS for a variety of diseases (e.g., cancer or neurological). The purpose of this study was to prepare a tumor-mimicking phantom (TUMP) model that can simulate competently a tumor that is surrounded by healthy tissue. The TUMP models were prepared using polyacrylamide (PAA) and agar solutions enriched with MR contrast agents (silicon dioxide and glycerol), and the thermosensitive component bovine serum albumin (BSA) that can alter its physical properties once thermal change is detected, therefore offering real-time visualization of the applied FUS ablation in the TUMPs models. To establish if these TUMPs are good candidates to be used in thermoablation, their thermal properties were characterized with a custom-made FUS system in the laboratory and a magnetic resonance imaging (MRI) setup with MR-thermometry. The BSA protein's coagulation temperature was adjusted at 55°C by setting the pH of the PAA solution to 4.5, therefore simulating the necrosis temperature of the tissue. The experiments carried out showed that the TUMP models prepared by PAA can change color from transparent to cream-white due to the BSA protein coagulation caused by the thermal stress applied. The TUMP models offered a good MRI contrast between the TMPs and the TUMPs including real-time visualization of the ablation area due to the BSA protein coagulation. Furthermore, the T2-weighted MR images obtained showed a significant change in T2 when the BSA protein is thermally coagulated. MR thermometry maps demonstrated that the suggested TUMP models may successfully imitate a tumor that is present in soft tissue. The TUMP models developed in this study have numerous uses in the testing and calibration of FUS equipment including the simulation and validation of thermal therapy treatment plans with FUS or MRgFUS in oncology applications.

Design, structural inspection of some new metal chelates based on benzothiazol- pyrimidin-2-ylidene ligand: Biomedical studies and molecular docking approach

The reaction of BSP benzothiazol-2-yl-(4,6 -dimethyl-1H-pyrimidin-2-ylidene)-amine with Fe3+, Ni2+ and Pd2+ resulted into three novel complexes. The ligand and metal complexes' structural details were revealed by M.P, IR, 1H NMR, 13C NMR, electronic spectra, CHN analysis, Mass spectra, TGA, magnetic susceptibility, as well as theoretical calculations have been performed at DFT level of theory using B3LYP functional and 6-31G (d, p) as a basis set. The DFT calculations' recommended structures and the observations from experiments match well. Using the information gathered, the complexes accommodated the molecular formulae; ([Fe(BSP)2(NO3)2](NO3).(H2O)), ([Ni(BSP)2(NO3)2].(H2O)) and ([Pd(BSP)(OCOCH3)2].(H2O)2) respectively. The produced compounds' in vitro antibacterial activities were assessed in comparison to various bacterial and fungi's stains by disc diffusion method in agar solution. The finding reflects that the metal complexes especially BSPPd complex much helpful antimicrobial initiatives towards S. marcescence and G. candidum contrasted to the other microbes. The compounds' antioxidant characteristics were assessed in order to assess their capacity to scavenge free radicals. Additionally, the compound's in vitro cytotoxicity towards MCF-7, HCT-116 and HepG-2 cell lines was adjudicated and it was discovered that there was an enhanced expression, which effectively destroyed cancer cells even at low levels. The geometry of BSP before and after docking was also compared displaying, suggesting fascinating further investigation.

MECHANICAL PROPERTIES OF AGAR SOLUTIONS AND GELS PREPARED USING WATER EXPOSED TO ELEC-TROMAGNETIC FIELD

The paper presents the results that continue the cycle of studies on the effect of a high-frequency field on water, which was later used to prepare agar solutions. The strength of agar gel (jelly) was studied depending on the conditions of field exposure to water. It is shown that the strength of the gel in a complex way depends on the frequency of field pretreatment and the time of water exposure after field exposure. The rheological properties were analyzed using the Ostwald-de Ville approximation equation. The dependence of the rheological constant (consistency coefficient) on the frequency of the field exposure and the exposure time after it is analyzed. Dependencies, as observed earlier, are non-systemic broken curves. The rheological properties and strength of the gel prepared in water that has undergone identical field treatment has been compared. The results can be conditionally divided into three groups: synbate change, antibate change and change of dependencies after 9 days of water exposure. It is shown that the strength and viscosity of the agar gel generally decreases. The complex dependences of strength and viscosity on factors affecting water are explained on the basis of the assumption of a complex and multilevel initial structure of water and its change both under the action of an electromagnetic field and over time as a result of thermal motion.

Cryopreservation of Lilium Candidum Germplasm: Analysis of Pre- and Post-freeze Treatments

BACKGROUND: Lilium candidum L. is a perennial ornamental plant that has various medicinal properties and is used in the cosmetic industry. The species is facing threats from urbanization and climate change and requires urgent protection. The most secure and efficient technology for the longterm storage of plant genetic resources is cryopreservation, which involves preserving genetic material at extremely low temperatures. OBJECTIVE: Today, plant biodiversity is endangered because of the narrowing of its natural distribution areas and/or destruction for different purposes. This study concentrated on creating a cryopreservation process using shoot tips and calluses as explant sources for the long-term conservation of L. candidum species. MATERIALS AND METHODS: Populations of L. candidum naturally distributed from three different regions of Turkey (Kepsut, Balikesir; the area surrounding Bafa Lake, Aydın ; and Fethiye- Mu la) were grown in vitro to supply shoot tip and callus explants. Prior to freezing by droplet-vitrification and vitrification techniques, shoot tips and calluses were treated with MS nutritional medium supplemented with 0.4 M sucrose 7 g/L agar and plant vitrification solution 2 (PVS2). RESULTS: Cryopreserved shoot tips showed the highest levels of regeneration (71.8%) after a PVS2 treatment of 90 min, while calluses showed the highest levels of regrowth (63.9%) after a PVS2 exposure of 60 min. CONCLUSION: High levels of regrowth are produced when the various cryopreservation procedures described here are used to preserve both shoot tip and callus explants. This potentially makes the method promising for the long-term preservation of endangered L. candidum varieties.

Analysis of the New York Subway System using an Adaptive Network Model

Through the use of a Physarum Polycephalum organism and a scaled-down model of the New York Subway System, this study created and analyzed a system of "maximum efficiency". By taking advantage of the capabilities of a Physarum organism, a system reminiscent of the existing subway system was created, with deviations analyzed to find differences in both track usage and overall costs. Previous research regarding Physarum Polycephalum and infrastructure development were relatively separate. This study holds similarities to research done by Atsushi Tero of Kyoto University, but while his team sought perfect replication, this study sought to use the growth patterns of Physarum to create a more efficient system. Using a geographically accurate mapping of the New York Subway System, a scaled-down model of the Subway System was created, with major subway stations represented as oat nodes atop an agar solution in a sterile petri dish. The Physarum was placed within and allowed to grow for roughly 6 days. Following the full connection of all oat nodes, an analysis of the Physarum system was conducted using a ModaCam system. This analyzed system was then scaled up to that of the existing Subway System, and a comparison of the two was conducted. This study concluded that the Physarum system was significantly more efficient than the existing system, using fewer subway tracks and consequentially a lower maintenance cost.

Investigation on the Flow Behaviour of Agar Solution and Rheological Modelling

In this study, the effect of shear rate, agar concentration (15-35 kg/m3) and temperature (30-60°C) on the apparent viscosity of the agar solution was investigated. Apparent viscosities at different shear rates were determined using a rotational viscometer. The findings show that the apparent viscosity decreasing with a rise of shear rate increased with increasing concentration. An increase in the tempearture, on the other hand, led to a decrease in the apparent viscosity. To illustrate both temperature and concentration changes together, the Bingham, power law, and Casson models were utilized in choosing the most suitable model. When the models were compared using statistical tests, the most compatible model was found to be the power-law model. The consistency coefficient and flow behaviour index calculated using the power law model showed that agar solutions exhibited shear-thinning flow behavior (pseudoplastic). This study suggests that power law, within the ranges of the temperature and concentration studied could be used to estimate the viscosity of the agar solutions in the applications requiring the knowledge of flow behavior.

OPTIMIZATION OF CONDITIONS FOR THE FORMATION OF STABLE GEL FROM AGAR-AGAR

Red seaweed is an important raw material for obtaining a natural gelling agent, thickener and stabilizer – agar-agar. In the work, agar was isolated from dried red seaweed of the genus Porphyra. The high rheological and gel-forming properties of agar were shown. The dependence of the concentration of the agar solution on the gel-forming ability was obtained. The range of concentrations at which the formation of the gel occurs (1.0–10.0%). The choice of optimal conditions (concentration, temperature) for the production of films has been substantiated. The effect of the plasticizer on the quality of films is shown. A direct dependence of the change in the swelling of the film in water on time and temperature – objective characteristics for their use for practical purposes – has been established. The critical concentration of agar micello formation is 0.05%. At this concentration, the surface activity of agar is 27.1 mJm/kg. An improvement in the properties of textile materials coated with agar solution has been established. Problems that need to be solved with further research are shown.

Preparation of pH-Responsive Films from Polyvinyl Alcohol/Agar Containing Cochineal for Monitoring the Freshness of Pork.

This study reported the production of pH-responsive films based on 8 wt% polyvinyl alcohol solution/0.2 wt% agar solution incorporated with cochineal-loaded starch particles (CSN) (2, 4, 6 and 8 wt% on agar basis) by a casting process. Results revealed that CSN presented obvious color changes over the pH range of 2-12. FTIR, XRD spectra and SEM micrographs presented that the incorporation of CSN formed new hydrogen bonds with a matrix and a tighter network structure. A certain improvement was observed in the color stability, swelling index and functional properties (antimicrobial and antioxidant activities) but water solubility, water vapor permeability and water contact angle of the pH-responsive films were decreased by the addition of CSN. The release of cochineal was a rate-limiting step following the Korsmeyer-Peppas model. The agar/polyvinyl alcohol film containing 6% CSN (PVA/GG-6) exhibited the best sensitivity for ammonia detection and its limit of detection was 35.4 ppm (part per million) for ammonia. The application trials showed that the PVA/GG-6 film presented different color changes for pork freshness. Hence, these pH-responsive films can be used as potential packaging materials for tracking the freshness of protein-rich fresh food in a non-destructive way.

Aqueous extract of chili pepper in the management of the pink hibiscus mealybug (Hemiptera: Pseudococcidae)

Maconellicoccus hirsutus (Hemiptera: Pseudococcidae) is a polyphagous pest, attacks several crops of economic importance, including cocoa and coffee. Due to its rapid dissemination, studies are needed to develop management programs to combat this pest, as few studies seek the effectiveness of alternative products such as plant extracts, which can be promising in its control. Therefore, this work aimed to evaluate the efficiency of the aqueous extract of the fruits of chili pepper Capsicum frutescens (Solanaceae) in the management of the pink hibiscus mealybug. The tests were carried out in acclimatized chambers regulated at a temperature of 25 ± 1 ºC, relative humidity of 70 ± 10%, and a 12-hour photophase. The treatments consisted of five extract concentrations: 0.0, 2.5, 5.0, 7.5, and 10% (weight/volume). Coffee leaves were submerged in the aqueous solution of pepper extract and mounted in Petri dishes with agar solution to transfer the mealybugs. Each treatment consisted of 10 repetitions with 10 young mealybugs each. The experiment was evaluated 24, 48, and 72 h after the procedure. Data were submitted for analysis of variance and regression test (p≤0.05). Lethal concentration (LC50) was estimated using Probit analysis. The mortality of mealybugs increased with the increase in extract concentrations, with mortalities greater than 70% from the lowest concentration. The data fit the Probit model, with χ² of 1.0478 (p > 0.05) and a curve slope of 1.7799. The LC50 was estimated at 0.96%. Thus, the aqueous extract of Capsicum frutescens fruits is promising for the management of M. hirsutus.

TOLERANCE OF IRRIGATED LOWLAND RICE VARIETIES TO IRON TOXICITY UNDER NUTRIENT SOLUTION AS MEASURED BY A DIGITAL IMAGE PROCESSING

<p class="abstrakinggris"><span lang="EN-US">Some improved irrigated lowland rice varieties are quite adaptive to tidal swamp areas where iron stress is the limiting factor of productivity. Information on irrigated rice tolerance to iron toxicity is inadequate and digital image processing for determining the level of tolerance is not available. The study aimed to evaluate tolerance of irrigated rice to iron toxicity. Ten irrigated rice varieties were used, namely Inpari 3, Inpari 19, Inpari 22, Inpari 24, Inpari 32, Inpari 42, Inpari 47, Inpari IR Nutri Zinc, Cakrabuana Agritan and Inpago 13 Fortiz. Mahsuri is tolerant and IR 64 is a sensitive check. The seedlings were planted on Yoshida agar solution using a randomized completely block design with four replications. Leaf bronzing symptoms showed that Inpari 47 was tolerant (score 2), Inpari 3 and Inpari 42 were moderately tolerant (score 4), Inpari 19 and Inpari 22 were also moderately tolerant (score 5). The bronzing symptom based on image processing has a strong correlation with visual observation, leading to propose that image processing is an alternative method to determine the bronzing symptom. Inpari 47 absorbed quite a lot of Fe with few bronzing symptoms. Inpari IR Nutri Zinc absorbed less Fe, but had more symptoms than Inpari 47. Inpari 19 had a longer shoot, while Inpari 42 and Inpari 47 had longer roots. Based on this study, Inpari 47 can be recommended for moderate iron stress-prone areas, meanwhile, Inpari 3, Inpari 42, Inpari IR Nutri Zinc, and Inpari 32 HDB for low iron stress-prone areas.</span></p>

Oxygen consumption and transportation in rice roots are highly dependent on leaf area and root dry weight ratio

As rice is cultivated under diverse moisture conditions from paddy to field, the internal morphology of their roots may be diverse within species. This study aimed to investigate which traits affect the root oxygen consumption and transportation ability using rice varieties with different root anatomical traits. First, the CSR of seminal roots of six rice varieties was used to identify a variety with a low CSR. Results showed that the CSR in Sensho was the lowest in both aerated and stagnant solutions. Second, the shoot morphological traits, root anatomical traits, and root oxygen consumption and transportation of four rice varieties, including Sensho, were examined in preaerated and deoxygenated agar solutions. Results showed that deoxygenated conditions did not have any negative effects on the growth of the rice varieties. The root oxygen consumption rates were strongly positively correlated with the leaf area/root dry weight (LA/RDW, r = 0.90). The root oxygen transportation rates were also positively correlated with LA/RDW (r = 0.57). The percentage of root oxygen consumption compensated by oxygen transportation was highest in IR42, which had a low LA/RDW. Multiple regression using stomatal conductance, LA/RDW, and shoot dry weight as explanatory variables explained only 65.0% of oxygen transportation. We concluded that further studies on gas movements inside the shoots and roots are needed to clarify the mechanism that provides more sufficient oxygen to the roots.

Study on formulation and preparation technology of the composite cellulose-based enteric capsule shells

Objective To study the new formulation and technology of composite cellulose-based enteric capsule shell with one-time dipping molding without organic solvent. Methods Hydroxypropyl methylcellulose phthalate-55S (Hp55S) was used as the main film-forming material, agar as gelling agent, and hydroxypropyl methylcellulose (HPMC) as disintegrating regulator. The preparation technology was as follows: ① Hp55S was dissolved in dilute ammonia solution with pH of 10 ∼ 11 at room temperature to obtain transparent Hp55S solution. ② The mixture of HPMC, KCl, and Tween-80 was fully dispersed in the agar solution at 90 ∼ 100 °C and cooled to 50 ∼ 55 °C under continuous stirring to obtain a transparent agar/HPMC solution. ③The Hp55S solution was heated to 50 ∼ 55 °C and poured into the agar/HPMC solution and stirred evenly to obtain the composite cellulose solution, which was kept at 50 ∼ 55 °C for standby. ④The composite cellulose-based enteric capsule shells were prepared by dipping, spinning, drying, stripping and trimming, and joining. Results The composite cellulose-based enteric capsule shell prepared according to this formula and process met the quality requirements of ‘enterosoluble vacant capsules’ in Chinese Pharmacopeia. Conclusion Compared with the traditional formula and preparation technology of enteric capsule shell, the product is a plant type enteric capsule shell, no organic solvent is used in the formula, and the forming steps of multiple dipping solution is not used in the process. The advantages of this study are that the production steps are simplified, the production process is environmentally friendly, and the production cost is reduced.