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Through biogenetic engineering, the posterior silk glands of Bombyx mori larvae are degenerated, and only the middle silk glands are retained to secrete sericin to produce sericin fibers, so as to obtain sericin cocoons with high sericin content (>98.5%). For this paper, sericin cocoons were studied, and the morphological structure characteristics and properties of sericin cocoons and common Bombyx mori cocoons were compared and analyzed through such modern test techniques as SEM, FTIR, and XRD. Results show that sericin cocoons have the basic morphological structure of cocoons, but because of the brittleness and hardness of sericin, the ssericin cocoons have poor integrity with a thermal decomposition rate that is higher than that of cocoons; the two cocoons are of a similar protein structure, with both α-helix and β-sheet structures, and dominantly the β-sheet structure; and the crystallinity of sericin cocoons (10.48%) is lower than that of the common Bombyx mori cocoons (27.10%). Sericin was extracted from both cocoons to obtain a mixed sericin solution respectively, which were coated on base fabrics of polyester taffeta (210T) for coating finish and subjected to qualitative research for their anti-UV properties. The base fabrics coated with mixed sericin solutions of sericin cocoons and Bombyx mori cocoons have an anti-UV performance index (UPF) of 23.9% and 22.5% respectively, which are higher than that of the base fabric (8.9%)..

Yarn linear density and linear density unevenness between fragments involve the mass and mass variation of yarn per unit length, which are important indices to reflect the uniformity of yarn thickness. Aiming at the shortcomings of the traditional testing method, which uses a yarn length tester to test these indices by counting length first and then cutting and measuring weight, a testing device that measures weight and counts length synchronously is designed and developed, so that the yarn can be continuous, recyclable, and reusable. Length counting is conducted by a length-counting disk connected to a photoelectric coded disk, and the result of length counting can be accurate to 0.01 m. The original skein frame with a perimeter of 1 m is replaced, so that the error caused by yarn overlapping is avoided. Through program control, the testing of a plurality of groups of linear density values can be completed at one time to calculate the linear density unevenness of different fragments of yarn, and the yarn can be led to a recovery spool through a yarn guide cylinder to form a new package. Polyester/viscose 65/35 blended yarn was taken as a test sample and subjected to statistical analysis using SPSS software. It is found that the results of the newly developed device are closer to the arbitration value; the whole experiment is completed at one time, which avoids the secondary error and reduces the labor intensity; and the raw materials can be recycled, which saves labor and raw material costs. The device has high value for industrialization and popularization.

Cocoon is a kind of natural biopolymer material with reasonable structure and various functions. However, its structure and functions are often destroyed in practical application. In this study, we took common Bombyx Mori as the research object, and provided different cocooning sites for single or multiple silkworms to construct common stereoscopic cocoons (“normal cocoons” [NC]) and flat cocoons (“single-silkworm flat cocoons” [SFC] and “multi-silkworm flat cocoons” [MFC]), respectively, and compared the morphological structure and basic properties of these cocoons. The study found that the flat cocoons have similar multi-layered variable structure and characteristics compared to those of the common cocoons; also, morphological characteristics and physical and chemical properties of silk fiber from outer layer to inner layer, such as sericin content, fiber fineness, and change rule of basic mechanical properties, are completely consistent with those of the common cocoons. It can be considered that the flat cocoons are constructed by silkworms in the same “procedural” process as that of common cocoons. Due to the expansion of cocooning space, the mechanical properties of fibers are significantly improved. By controlling the size of the cocooning space or the quantity of silkworms cocooning simultaneously, and the time of spinning, a cocoon material with controllable thickness, weight per square meter, porosity, and number of cocoon layers can be obtained as a composite material for direct application.

BackgroundIndocyanine green fluorescence-guided laparoscopic hepatectomy (ICG-guided LH) is increasingly used for the treatment of hepatocellular carcinoma (HCC). However, whether ICG-guided LH can improve surgical outcomes remains unclear. This study aimed to investigate the short-term outcomes and survival outcomes of ICG-guided LH versus common laparoscopic hepatectomy (CLH) for HCC.MethodsWe conducted a retrospective analysis of 104 ICG-guided LH and 158 CLH patients from 2014 to 2020 at our center. To avoid selection bias, 81 ICG-guided LH and 81 CLH cases were analyzed after 1:1 propensity score matching (PSM). The baseline data and results were compared between the two groups.ResultsThe baseline characteristics of both groups were comparable after matching. There was a significant difference in operative time: longer in the ICG-guided LH group than in the CLH group (p=0.004). However, there was no significant difference in operative time in anatomical resection between the two groups (p=0.987). There was a significant difference in operative time in non-anatomical resection: longer in the ICG-guided LH group than in the CLH group (p=0.001). There were no significant differences in positive surgery margin, blood loss, blood transfusion rate, postoperative complication rate, postoperative length of hospital stay, mortality within 30 days, and mortality within 90 days. The ICG-guided LH group appeared to have a trend towards better overall survival (OS), but there was no significant difference in OS (P=0.168) and recurrence-free survival (RFS) (P=0.322) between the two groups.ConclusionsAlthough ICG fluorescence-guided LH is a timelier procedure to perform, it is a safe and effective technique with the advantages of intraoperative positioning, low postoperative complication rates, and potential to improve OS.

Soy protein isolate (SPI), a widely available and inexpensive natural polymer, can be used as a filler to reduce the cost of poly(butylene adipate-co-terephthalate) (PBAT) materials. To improve the compatibility between SPI and PBAT, a series of polycaprolactone-based polyurethane prepolymers (PCLPUs) with different soft segment molecular weights were synthesized and used as compatibilizers to prepare SPI/PBAT composites. At the same time, the effect of PCLPU soft segment molecular weight on the properties of SPI/PBAT composites was studied. Structural, morphological, and property analyses were carried out on the composite materials; the results showed that PCLPU was an effective compatibilizer for SPI/PBAT composite materials. The -NCO group at its end forms a urethane bond with the hydroxyl group in SPI and PBAT. At the same time, the soft segment of PCLPU is physically crosslinked with PBAT to produce a dual physical and chemical effect. The lower the soft segment molecular weight of PCLPU added, the better the performance of the SPI/PBAT composite materials. This is observed because PCLPU with a lower soft segment molecular weight contains more -NCO functional groups, which can better achieve compatibilization between SPI and PBAT through chemical crosslinking. The addition of 5% PCLPU-500 content to the SPI/PBAT composite material increased its tensile elongation, impact strength, and tensile strength by 867%, 264%, and 150%, respectively, compared with those of the SPI/PBAT composite material without a compatibilizer, achieving toughening and strengthening with good processability and biodegradability. This work provides a simple, effective solution for preparing high-performance, green, and low-cost biodegradable composite materials. Highlights * PBAT composites were prepared using soy protein isolate (SPI) as filler. * Different types of PCLPU exist as a reactive compatibilizer for PBAT and SPI. * Polycaprolactone-based polyurethane prepolymer significantly improves the interfacial compatibility of PBAT composites. * SPI/PBAT film has good degradability and is a rich source of nitrogen. KEYWORDS biodegradation, composite film, PBAT, PCLPU, soft segment molecular weight, soybean protein isolate, 1 | INTRODUCTION Plastic is an essential organic synthetic polymer material with many applications. However, while bringing convenience to human life, the 'white pollution' caused by plastic is becoming increasingly [...]