Promotive and inhibitory effects of rice straw and cellulose application on rice plant growth in pot and field experiments

Abstract

Quantitative characterization of crusts is necessary to evaluate the crusting susceptibility of soils, to reveal the soil properties affecting soil crust development and, thus, to predict the occurrence of crusting. For the quantification of the morphological characteristics of soil surface crusts, the authors applied an image analyzing method to quantify the state of pores, in terms of apparent porosity, using vertical thin sections of the surface crust formed under simulated rainfall.     

Physicochemical and Pharmaceutical Properties of Carboxymethyl Rice Starches Modified from Native Starches with Different Amylose Content

Carboxymethyl rice starches (CMRS) were prepared from nine strains of native rice starches with amylose contents of 14.7–29.1%. The reaction was conducted at 50°C for 120 min using monochloroacetic acid as a reagent under alkaline conditions and 1-propanol as a solvent. After determining the degree of substitution (DS), the physicochemical properties including water solubility, pH, and viscosity of 1% (w/v) solution, scanning electron microscopy (SEM), and X-ray diffraction (XRD) analyses of the granules, as well as some pharmaceutical properties of CMRS powders and pastes were investigated. The DS range was 0.25–0.40. All CMRS dissolved in unheated water and formed viscous gel. A good positive correlation was observed between amylose content and DS (r = 0.9278) but not viscosity. SEM and XRD concurrently revealed significant physical alteration of CMRS granules compared with those of native starches, which reflected the changes in the properties of CMRS. At 3% (w/w), CMRS can function as tablet binder in the wet granulation of both water-soluble and water-insoluble diluents. The tablets compressed from these granules showed good hardness with fewer capping problems compared with those prepared using the pregelatinized native rice starch as a binder. In addition, most CMRS pastes formed clear films with varying film characteristics, depending upon the amylose content of the native starches. This type of modified rice starch can potentially be employed as a tablet binder and film-former for pharmaceutical dosage formulations.     

Preparation and characterization of blended <Emphasis Type="Italic">Bombyx mori</Emphasis> silk fibroin scaffolds

The aim of this study was to compare physical, mechanical and biological properties of 3-dimensional scaffolds prepared from Bombyx mori silk fibroin (SF), fibroin blended with collagen (SF/C), and fibroin blended with gelatin (SF/G) using a freeze-drying technique. The prepared scaffolds were sponge-like structure that exhibited homogeneous porosity with highly interconnected pores. Average pore size of these scaffolds ranged from 65–147 μm. All biodegradable scaffolds were capable of water absorption of 90 %. The degradation behavior of these scaffolds could be controlled by varying the amount of blended polymer. The SF/C and SF/G scaffolds showed higher compressive modulus than that of SF scaffolds which could be attributed to the thicker pore wall observed in the blended constructs. The less crystalline SF structure was observed in SF/G scaffolds as compared to SF/C scaffolds. Thus, the highest compressive modulus was observed on SF/C matrix. To investigate the feasibility of the scaffolds for cartilage tissue engineering application, rat articular chondrocytes were seeded onto the scaffolds. The MTT assay demonstrated that blending collagen or gelatin into SF sponge facilitated cell attachment and proliferation better than SF scaffolds. The blended SF scaffolds possessed superior physical, mechanical and biological properties in comparison to SF scaffolds and showed high potential for application in cartilage tissue engineering.     

Physicochemical and Pharmaceutical Properties of Cross‐Linked Carboxymethyl Rice Starch Prepared by a Simultaneous Dual Reaction

Cross‐linked carboxymethyl rice starches (CL‐CMRS) were prepared from reactions between a native Klong Luang 1 (KL1) rice starch and varied concentrations (2.5–15% w/w) of sodium trimetaphosphate (STMP) in simultaneous carboxymethylation and cross‐linking reactions set up using methanol as a solvent. Physicochemical as well as pharmaceutical properties of CL‐CMRS were evaluated in relation to the amount of STMP used and the degree of cross‐linking (DCx). At a low DCx, the viscosity of CMRS solution was enhanced through the formation of cross‐linked polymeric network and chain entanglement. At higher concentrations in the preparation reaction, STMP caused proportional decreases in the water solubility and ≤70‐fold of the solution viscosity, but promoted swelling and water uptake of the modified starches. Rheological behavior of the nonsoluble but swellable CL‐CMRS was similar to that of commercial superdisintegrants sodium starch glycolate (SSG), and cross‐carmellose sodium (CCS). The swelling and water uptake of CL‐CMRS were 5–7 and 6–25 times higher, respectively, than that of the native starch. Disintegration test of tablets containing 1 and 3% w/w of native and modified rice starches showed that M‐KL1‐5 and M‐KL1‐10 could be developed as tablet disintegrants.     

利用高光谱成像技术和多变量校正方法检测苹果的硬度（英）

高光谱图像集图像信息与光谱信息于一身,应用于农产品品质无损检测领域。该研究尝试利用高光谱图像技术结合多变量校正方法检测苹果硬度的可行性。试验通过获取的高光谱图像中提取有效的光谱信息来建立预测苹果硬度的预测模型。在建立模型过程中,偏最小二乘（PLS）和支持向量回归（SVR）两种多变量校正方法被比较,结果表明在785.11～872.45 nm范围内,SVR模型的性能优于PLS模型,模型对硬度预测结果的相关系数为0.6808。试验结果表明高光谱图像技术可以被用来检测苹果的硬度。