Preparation of Regenerated Silk Fibroin Hybrid Fibers with Hydrogen Peroxide Sensing Properties by Wet Spinning

Silk is widely used in the production of high-quality textiles.At the same time,the amount of silk textiles no longer in use and discarded is increasing,resulting in significant waste and pollution.This issue is of great concern in many countries where silk is used.Hydrogen peroxide as a naturally occurring compound is an important indicator of detection in both biology and the environment.This study aims to develop a composite fiber with hydrogen peroxide-sensing properties using discarded silk materials.To achieve this goal,firstly,polydopamine(PDA)was used to encapsulate the ZnFe_(2)O_(4) NPs to achieve the improvement of dispersion,and then regenerated silk fibroin(RSF)and PDA@ZnFe_(2)O_(4)/RSF hybrid fibers are prepared by wet spinning.Research has shown that PDA@ZnFe_(2)O_(4)/RSF demonstrates exceptional sensitivity,selectivity,and stability in detecting hydrogen peroxide,while maintaining high mechanical strength.Furthermore,the complete hybridization of PDA@ZnFe_(2)O_(4) with silk fibroin not only results in the combination of the durability of silk fibroin and PDA@ZnFe_(2)O_(4)’s rigidity,ensuring a reliable service life,but also makes PDA@ZnFe_(2)O_(4)/RSF exhibit excellent catalytic activity and biocompatibility.Therefore,the composite fiber exhibits exceptional mechanical properties and reliable hydrogen peroxide sensing capabilities,making it a promising material for biological and medical applications.

A Review on the 3D Printing of Functional Structures for Medical Phantoms and Regenerated Tissue and Organ Applications

Medical models, or ＂phantoms,＂ have been widely used for medical training and for doctor-patient interactions. They are increasingly used for surgical planning, medical computational models, algorithm verification and validation, and medical devices development. Such new applications demand high-fidelity, patient-specific, tissue-mimicking medical phantoms that can not only closely emulate the geometric structures of human organs, but also possess the properties and functions of the organ structure. With the rapid advancement of three-dimensional （3D） printing and 3D bioprinting technologies, many researchers have explored the use of these additive manufacturing techniques to fabricate functional medical phantoms for various applications. This paper reviews the applications of these 3D printing and 3D bioprinting technologies for the fabrication of functional medical phantoms and bio-structures. This review specifically discusses the state of the art along with new developments and trends in 3D printed functional medical phantoms （i.e., tissue-mimicking medical phantoms, radiologically relevant medical phantoms, and physiological medical phantoms） and 3D bio-printed structures （i.e., hybrid scaffolding materials, convertible scaffolds, and integrated sensors） for regenerated tissues and organs.

One Rapid and Efficient Method for Isolation of Total RNA from Shoots Regenerated in vitro of Populus suaveolens

Total RNA was isolated from shoots regenerated in vitro of Populus suaveolens by the modified method of CTAB, and two clear bands of rRNA (28S and 18S) were observed in agarose electrophoresis. In addition, the values of OD260/OD280 and OD260/OD230 of extracted RNA were 2.12 and 2.23 respectively. The results show that RNA is little decomposed and the purity of RNA is high. Moreover, RNA isolated by the modified method of CTAB reagent had been successfully used for reverse transcription of P. suaveolens cDNAs and ideal special band was observed.

Interfacial Interaction Between Polyurethane/Poly(Methacrylateco-Styrene) Coating and the Regenerated Cellulose Film

Water-resistant films were prepared by coating the surface of regenerated cellulose films with castor oil-based polyurethane (PU)/ poly-(methacrylate-co-styrene) [P (MA-St)]. The effects of the ratio of PU to P (MA-St) copolymer on tensile strength (dry and wet states), vapor permeability, size stability, and water resistivity of the coated films were studied. The interfacial interaction between cellulose and the PU/P (MA-St) coating was analyzed using infrared (IR), ultraviolet (UV), scanning electron microscopy (SEM), transmission electron microscopy (TEM), differential thermal analysis (DTA), and electron probe microanalysis (EPMA). The results indicated that the mechanical properties and water resistivity of the coated films significantly enhanced, and the biodegradability was displayed, when the ratio of PU to P (MA-St) was 8∶2 by weight. The chemical bonds and hydrogen bonds between the cellulose, PU, and the copolymer exist in the coated films. It is regarded that PU/P (MA-St) semi-interpenetrating polymer networks (IPNs) were formed, and a shared network of PU with both the cellulose and the coating in the coated film occurred simultaneously resulting in a strong bonding between the coating layer and the film.

Fine Structure of Regenerated Silk Fibroin Solids

The fibroin solids (membrane and gel) were prepared from regenerated silk fibroin solution in different ways. The structure of the fibroin solids and its change during storage were studied. The results indicated that the structure of fibroin membrane air-dried at 30℃ or freeze dried at a freezing temperature of -20-4℃ was the coexistence of amorphous and silkⅠstructure. The amorphous region could partly be transformed into silkⅠstructure under room temperature and humidity. The structure of porous silk fibroin membrane was the coexistence of amorphous and small part of silkⅡ, if the aqueous fibroin was freeze dried within the temperature range of -80℃ to -20℃, and the amorphous partly transformed into silkⅠ during storage. The structure of fibroin gel naturally forming when kept at room temperature was coexistent of amorphous and silkⅡ. The content of Gly and Ala was high in the surface membrane of aqueous fibroin and its structure was mostly silkⅠ and silkⅡwith high crystallinity.

Modificatin of ITZ Structure and Properties of Regenerated Concrete

By means of reducing the ratio of water to cement （ w/c ）, incorporating a proper amount of fly ash and superplasticizer , and processing the surface of recycled aggregate （ RA ）, this paper aims at improving the interfacial transition zone （ITZ） submicro- structure of the regenerated concrete （ RC ）. The experimental resuits of mercury intrusion pressure （MIP） show that RA pretreated by PVA polymer solution and lyophobic active agent can jam its surface pore and hole, thus the porosity of RA is decreased. When reducing w/c ratio, incorporating 20% of fly ash （ FA ） and 2.5% of superplasticizer （ to cement ） in the RC , the width of ITZ is effectively narrowed, the structure of ITZ is combined much more compact and the compressive strength of RC is enhanced. Under the same conditions, using RA pretreated by 1% PVA polymer solution, the fluidity of fresh RC can be enhanced and the compressive strength of hardened RC can also be enhanced lightly. Whereas using RA pretreated by lyophobic active agent, the fluidity of fresh RC can be enhanced , but it impairs the adhesion of fresh cement paste and the surface of old concrete, and hinders the strength development of RC. In the ITZ structure of ordinary concrete （prepared with natural coarse and fine aggregate ）, there are much Ca （ OH）2, in plank-and sheet-like, distributing with priority tropism, whereas in the RC structure, Ca（ OH）2 with a coarse size is not found in ITZ ; the main reason is that the surface of coarse aggregate does not have a layer of water film.

Effects of Coagulation Conditions on Tensile Properties of Regenerated Cellulose Fibers

The effects of coagulation conditions on tensile properties of the regenerated cellulose fibers prepared by wet-spinning from NaOH/thiourea/urea(8∶6.5∶8 by weight)aqueous solvent were investigated by tensile tester,X-ray diffraction(XRD),and scanning electron microscope(SEM).The results show that the tensile properties of the as-spun fibers change with the coagualtion concentration,temperature,and time.When the spinning solution is coagulated in 10% H2SO4/12.5% Na2SO4 aqueous solution,the as-spun fibers have a typical structure of cellulose II,a circular cross-section,and homogeneous morphological structure.

CHARACTERIZATION OF REGENERATED CELLULOSE MEMBRANES HYDROLYZED FROM CELLULOSE ACETATE

A series of cellulose acetate membranes were prepared by using formamide as additive, and then were hydrolyzed in 4 wt% aqueous NaOH solution for 8 h to obtain regenerated cellulose membranes. The dependence of degree of substitution, structure, porous properties, solubility and thermal stability on hydrolysis time was studied by chemical titration, Fourier transform infrared spectroscopy, scanning electron microscopy, wide-angle X-ray diffraction, and differential scanning calorimetry, respectively. The results indicated that the pore size of the regenerated cellulose membranes was slightly smaller than that of cellulose acetate membrane, while solvent-resistance, crystallinity and thermostability were significantly improved. This work provides a simple way to prepare the porous cellulose membranes, which not only kept the good pore characteristics of cellulose acetate membranes, but also possessed solvent-resistance, high crystallinity and thermostability. Therefore, the application range of cellulose acetate membranes can be expanded.

STUDIES ON TUNG OIL COATED REGENERATED CELLULOSE FILMS WITH WATERRESISTANCE

Regenerated cellulose films with water-resistance were obtained by an improved method ofpreparing cellulose cuoxam solution from pulps of agricultural wastes (linters, wheat straw, reedand Bamao). Experimental results showed that the mechanical properties of both the dry. and wetfilms were excellent. Data from IR, SEM and tensile strength measurements implied that thesignificant improvement of water-resistance of the films was due to the cohesion between the thinTung oil covers with hydrophobicity and the regenerated cellulose films. The films werecompletely biodegraded after being buried in soil for 100 days. The transmittance of the filmsderived from linter and reed in visible band range were 80-90%.

BIODEGRADATION OF REGENERATED CELLULOSE FILMS BY FUNGI

The biodegradability of Aspergillus niger (A. niger), Mucor (M-305) and Trichoderma (T-311) strains on regenerated cellulose films in media was investigated. The results showed that T-311 strain isolated from soil adhered on the cellulose film fragments has stronger degradation effect on the cellulose film than A. niger strain. The weights, molecular weights and tensile strengths of the cellulose films in both shake culture and solid media decreased with incubation time, accompanied by producing CO2 and saccharides. HPLC, IR and released CO2 analysis indicated that the biodegradation products of the regenerated cellulose films mainly contain oligosaccharides, cellobiose, glucose, arabinose, erythrose, glycerose, glycerol, ethanal, formaldehyde and organic acid, the end products were CO2 and water. After a month, the films were completely decomposed by fungi in the media at 30 degrees C.

Conformational Transitions and Self-assembly of Regenerated Spider Silk Protein in Water

Spider silk, relying on its exceptional mechanical properties, has attracted extensive attention throughout the world. The structure of a material can influence its mechanical properties. Investigation of the structure of spider silk includes amino acid composition, molecular structure, self-assembly, and crystallization, among other characteristics. Herein, the effects of concentration, time, alkali metal ions （Na^＋and K ^＋ ） and pH on the conformational transition and self-assembly of regenerated Ornithoctonus huwena spider dragline silk protein （spidroin） in water were investigated using circular dichroism （CD） and atomic force microScopy （AFM）. Spidroin concentration, time and Na ＋ ions slightly influenced the conformational transition of spidroin molecules. However, K ＋ ions and pH induced the formation of a β- sheet structure. Increasing spidroin concentration or time increased the aggregation of spidroin and enhanced the formation of nanoffiaments. K ~ ions enhanced the serf-assembly of spidroin into nanofilaments. The self-assembled nanofilaments appeared at a pH of approximately 6. 11. Both lower and higher pH induced aggregation. At a lower pH, the aggregation was composed of nanopartides, whereas higher pH induced the aggregation of nanoffiaments, likely from the synergistic effect of Na ^＋ ions and pH.

Reassembly of the axon initial segment and nodes of Ranvier in regenerated axons of the central nervous system

Myelinated axons of the peripheral and central nervous system（PNS＆CNS）are divided into molecularly distinct excitable domains,including the axon initial segment（AIS）and nodes of Ranvier.The AIS is composed of a dense network of cytoskeletal proteins,cell adhesion molecules,and voltage gated ion channels and is located at the proximal most region of the axon（Koleand Stuart, 2012）.

Effects of regenerated tissue extracts after liver injury on the proliferation,differentiation,migration and invasion of SK-HEP1 cells

Objective: To study the effects of regenerated tissue extracts after liver injury on the proliferation, differentiation, migration and invasion of SK-HEP1 cells. Methods: Regenerated tissue extracts after liver injury were used to induce SK-HEP1 cells after enrichment, their effects on the proliferation, differentiation, migration and invasion of SK-HEPI cells were observed through in vitro cell culture, MTT, flow cytometry and transwell assays. Results:In response to the action of regenerated tissue extracts after liver injury, SK-HEP1 cells were blocked in G_0/G_1 phase, their growth rate was distinctly reduced. The number of SK-HEP1^(-fj)colonies decreased. The migration ability of SK-HEPI cells showed a decreased trend on day7 and day 11 after induction. SK-HEPl's invasion ability clearly decreased on days 7 and11 after induction, especially on day 7. Conclusions: To a certain extent, regenerated tissue extracts after liver injury can inhibit the proliferation, differentiation, migration and invasion of hepatoma cells, showing an important potential of being a differentiating agent for the treatment of liver cancer.

Study on the Performance of Regenerated Catalyst for Ammonoximation of Cyclohexanone

The study on the deactivated catalyst and the regenerated catalyst for the 70 kt/a cyclohexanone ammonoximation commercial test unit had revealed that addition of a proper amount of silicon additive could suppress the solubilization-induced loss of silicon in catalyst while providing protection to the catalyst. Compared to the direct calcination method for catalyst regeneration, adoption of the regeneration method through pretreatment-calcination of catalyst could be more beneficial to the restoration of catalyst channels and enhancement of the performance of the regenerated catalyst, which could be repeatedly regenerated and utilized. The outcome of commercial scale testing of the catalyst had indicated the good performance of the regenerated catalyst, which could be used for four times, resulting in a reduction of the production cost of cyclohexanone-oxime in big chunks.

Unexpected Postoperative Paraplegia after Thoracotomy in Lung Cancer: Incidental Migration of Oxidized Regenerated Cellulose Used for Hemostasis of Intercostal Space Bleeding

Background: We experienced a very rare complication, that is, an unexpected postoperative paraplegia due to the incidental migration of oxidized regenerated cellulose used for hemostasis of intercostal space bleeding. Patients and Methods: The objective is to analyze the cause and to take measures against the very rare complication from an empirical analysis and the literature. For a 78-year-old male with suspected lung cancer in the right upper lobe (S1), a thoracotomy was performed. For hemostasis of the bleeding from the 5th intercostal thoracotomy space, we used and placed oxidized regenerated cellulose at the continuous oozing bleeding sites. On the 3rd postoperative day, paralysis beneath thoracic vertebrae level 6 was observed. Immediate computed-tomographic (CT) scanning and magnetic resonance imaging (MRI) displayed a 17 × 9 × 14 mm epidural hematoma in the spinal canal at level 5 of the thoracic vertebrae. An emergent laminectomy for the thoracic vertebra was performed to remove the oxidative cellulose and haematoma, and the compression was released. The paraplegia gradually began to recover and maintain a standing position. After 1 year from the event, the patient can walk by himself with a crutch. Results: The causes were that the oxidative cellulose materials were used for the intercostal bleeding at the open thoracotomy. The migration of the oxidative cellulose materials into the epidural space and into thoracic spinal canal through the intervertebral foramen, or gradual penetration of the oxidative cellulose materials into the spinal canal due to respiratory costal movement. As a measurement of prevention, the hemostat materials should be completely removed after finishing of the hemostasis. In the case of a difficult hemostasis, consultation of an orthopedist or neurosurgeon to perform the appropriate hemostasis in good cooperation is required. Conclusion: If postoperative paraplegia is suspected, immediate CT scanning and/or MRI examination would become powerful diagnostic procedures as soon as possible to start an interventional treatment.

Batch Studies for the Removal of a Hazardous Azo Dye Methyl Orange from Water through Adsorption on Regenerated Activated Carbons

The study of the performances of regenerated activated carbons for the adsorption of MO(methyl orange)in an aqueous medium was carried out with the aim to evaluate the adsorption capacities of these activated carbons.Three regenerated activated carbons issued from the unit of oil treatment of the thermal power station of Dibamba(Cameroon)-DPDC(Dibamba Power Development Company)were obtained thermally and chemically.These three samples(namely CAR 400℃(chemical regenerated activated carbon at 400℃),CAR 700℃(physical regenerated activated carbon at 700℃)and CAR 900℃(physical regenerated activated carbon at 900℃))and the non-used one CA were characterized by iodine number,XRD(X-ray Diffraction)and FTIR(Fourier-transform infrared spectroscopy).MO adsorption tests were performed in batch mode;this technique allowed the study of the influence of the parameters such as:the contact time,the initial’s MO concentration and the pH.Moreover,different kinetic models(first-order,pseudo-second-order and Webber and Morris intra-particle diffusion)and adsorption isotherms(Langmuir and Freundlich)are used for the evaluation of adsorption capacities.The physicochemical characterization of these adsorbents showed that they were micro-porous(iodine value:600 mg/g)and strongly crystallized according to their regeneration pathways.The influence of the parameters revealed that the adsorption of MO is the most favorable for concentrations from 5 to 25 mg/L(for materials CA and CAR 400℃)and 10 to 25 g/L(for materials CAR 700℃ and 900℃);and that it was maximum in acid medium(at pH=3 on the materials CA,CAR 400℃,CAR 900℃ and at pH=5 on the material CAR 900℃).The modeling of the adsorption kinetics of MO has revealed the conformity of the kinetic model of pseudosecond-order and intra-particle diffusion for some of these materials.The study of isotherms has shown that the Langmuir isotherm best describes the adsorption of MO on most of these adsorbents.

Biometric Analysis on Genetic Divergence between Parental and Regenerated Accessions in Tall Coconut Palms (Cocos nucifera L.) from International Genebank for Africa and the Indian Ocean

This study endeavour assesses agromorphological likeness between initial introductions and regenerated accessions at the International Coconut Genebank for Africa and the Indian Ocean (ICG-AIO) based in C?te d’Ivoire. Ten couples of parental (G0) and regenerated (G1) accessions of Tall coconut palms were analyzed using Principal Component Analysis (PCA) and Multiple Analysis of Variance (MANOVA) from 26 agromorphological characters. The main results showed a relative decrease in the expression of the phenotypical traits concerning the component of the fruit, height and vigor of the stem and yield of bunches and fruits after one regeneration cycle. But, a high proportion (69%) of studied characters from leaf, inflorescence and nut components showed likeness between G0 and G1 accessions. After one regeneration cycle, the controlled pollination method guarantees significant conservation of the expression of the majority of agromorphological traits. Consequently, regenerated accessions of Tall coconut palms can be used to pursue research and development programs in C?te d’Ivoire.

FROM EMG CONTROLLING TO"REGENERATED FINGER" CONTROLLING ARTIFICIAL HAND-THE RECENT ACHIEVEMENT IN REHABILITATION ENGINEERING

According to the sampling statistics there are over 7 millions limb disabled persons in China from several times of those in the world. For the benefit to the amputees, thousands varies kinds of commencial Products of artificial hands, by scientific promotion have ben developed in the recent half century. Among those products the EMG controlling artificial upper limb brings the hope to the amputees. The later are now used widely form the earlest one in 1948.In 1978, Shanghai Jiao Tong University began to study and develop the EMG controlling artificial band mounted to amputes over thousand disabled during a couple of recent decades.The risidual muscles of an amputee are the signal source of the artificial hand controlled by EMG. The evoked EMG which can transmit the brain moving information is one of the bioelectricities from human body. The EMG signal, accumulated at skin surface with surface electrodes, passing through filtering and amplifying circuits controls the movement-this is the main principle of EMG controlling artificial hand.But, owing to the weakness of EMG (μv) and a group of muscles information plus the strong turbulence of electric field (v), the integrated EMG can’t completely reflect the brain moving act and will influence the accuracy of EMG-hand, especially those of the multi-multi-degree of freedom.In 1978, only 57% of the controlling aaccuracy of artificial hand with 3-degree of freedom could be reached by the Herbert’s research. In 80’s, the controlling accuracy raised up to 72% by Denning’s new method. Up to now, the accuracy is still not ideal, eventhrogh the Hi-tech of using pattern-recognitionand artincial neuro-net work. The electronic artificial hand will be considered successful and practical only with the moving accuracy more than 95%.Some research by using implant electrode for detecting the neuro-information or EEG controllingmethod met also dimculties for raising the accuracy of artificial hand.For breaking througll the threshold of accuracy limit, the EMG method as mentioned above must bechanged entirely, A newest creative research work on the electronic artificial hand controlled by a "regenerated finger" made by transplanting a toe to the stump is developing in Shanghai Jiao TongUniversity, which is without precedent in the world.The first experimental amputee using "regenerated finger’ to control an electronic artificial forearm with 3-degree of freedom reaches 100% accuracy of movements (i.e. no error within 100 tests). It has been proved that the use of a "regenerated finger" as a controlling signal command makes it possible to use the electronic artificeal hand with multi-degree of freedom without error Thecombining medical science with engineering in the area of designing an electronic artifical upper limb.Acknowledgement: The authors extend their hearty thanks to the famous academician Dr.Chen Zhongwei (Zhong-Sen Hospital) for their creative effort and successful micro-surgical operation for transplanting toe to stump of an amputee, also to the China Science Foundation for supporting. us the fund to develop this research.

Molecular identification of plants regenerated from somatic hybridization between rice and apomictic Panicum

We attempted to introduce apomictic gene(s)into rice via somatic hybridization by usingapomictic Panicum maximum Jacq.as thedonor of apomictic gene(s).Protoplasts of rice derived from suspen-sion cells were inactivated with indoacetamide(IOA)and protoplasts of Panicum maximum

Plants regenerated from mesophyll protoplasts of white mulberry

Morus alba(white mulberry) mesophyll protoplasts were isolated from leaves of 30-45 day old sterile shoots,with protoplast yields of 2.5 x 107 g-1/F.W. after purification. The protoplasts were cultured in a modified K8P liquid medium containing 0.2 mg/L 2,4-D(2,4- Dichlorophe-noxy acetic acid), 1 mg/L NAA(Naphthyl acetic acid) and 0.5 mg/L BA(6-benzylaminopurine). A low plating density (5 x 104/ml) proved to be favourable to the division of protoplast-derived cells. The first divisioll occurred 4 days after culture, and the division frequency reached 24% at 10 days. A number of cell colonies and microcalli formed in 6 weeks. The microcalli were transferred onto MSB medium with 0.5 mg/L NAA and 0.5 mg/L BA for further proliferation. Shoot formation was initiated when the calli of 3-4 mm in size were transferred onto MSB differentiation medium with 0.1 mg/L NAA and 1 mg/L BA. The frequency of shoot formation was 35%. The shoots of 4-5 cm in height were excised from the callus and rooted on half strength MS medium with 0.5 mg/L IBA and 0.1 mg/L BA. After transplantation into pots, the regenerated plants grew vigorously in the phytotron.