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Polymeric biocomposites display some advantages over metal or ceramic biomaterials, and are regarded as a promising candidate for artificial joint application. Herein, molybdenum disulfide (MD) nanosheets were prepared and incorporated into polyimide (PI) to form MD/PI composites with a MD content of 20 wt% (PM20) and 40 wt% (PM40). The results revealed that incorporation of MD nanosheets obviously improved the tribological performances, surface properties (

Gastric cancer (GC) is the most common gastrointestinal malignancy worldwide. However, the molecular mechanisms of the progression of GC are not fully understood. Ras-responsive element binding protein 1 (RREB1) is an oncogene in many types of cancer that is involved in various biological processes, such as DNA damage repair, cell growth and proliferation, cell differentiation, fat development, and fasting glucose balance. In this study, we demonstrate the role of RREB1 in gastric cancer. First, by immunohistochemistry staining (IHC) and bioinformatics analysis, we demonstrated the expression of RREB1 in gastric cancer and paired normal gastric tissues. Then, we established RREB1 overexpression and knockdown cell lines via lentiviral transfection and detected cell proliferation by using MTT, colony-forming, cell cycle and apoptosis assays in vitro. We demonstrated the effect of RREB1 on cell proliferation in vivo by using a subcutaneous xenograft tumor model in nude mice. Finally, by using Western blotting and IHC, we demonstrated the possible mechanism by which RREB1 affects cell proliferation. The IHC and bioinformatics analyses demonstrated that RREB1 was highly expressed in gastric cancer and showed that RREB1-expressing patients had a larger tumor size and more lymphovascular invasion than RREB1-negative patients. Knockdown of RREB1 inhibited cell proliferation in vivo and in vitro. Knockdown of RREB1 enhanced p16 expression in vivo and in vitro, and p16 expression was negatively related to RREB1 in gastric cancer tissue. RREB1 was highly expressed in gastric cancer, and knockdown of RREB1 inhibited cell proliferation via enhanced p16 expression.

To evaluate the value of metagenomic next-generation sequencing (mNGS) in detecting pathogenic bacteria of cholangitis for patients with biliary atresia after Kasai operation.This study retrospectively analyzed patients of biliary atresia with cholangitis after Kasai operation who were admitted to Xi'an Children's Hospital from July 2019 to December 2021. Both blood culture and mNGS were carried out in all of these patients. We compared the detection rate of pathogenic bacteria, pathogenic bacteria spectrum, test time, inflammatory indicators and liver function. All the patients were followed up for 0.5-3 years to evaluate the onset of cholangitis and the survival status of autologous liver.This study included total of 30 cholangitis occurred in 25 patients. There were significant differences in the detection rate of pathogenic bacteria [23.3 vs.73.3%, P 0.05] and the test time [120 (114.5-120) vs.16 (16-21) h, P 0.001] between the blood culture and mNGS. These two methods showed significant statistical differences in comparing inflammatory indicators (CRP, PCT) and liver function (TB, DB, GGT) before and after anti-infection. Four kinds of bacteria were detected by blood cultures and ten kinds of bacteria were detected by mNGS. Cholangitis occurred 3 times in one case (4%) and twice in three cases (12%). Autologous liver survived in 17 cases (68%).Comparing with traditional blood culture, mNGS is more efficient, convenient and accurate in the detection of pathogens. It provides a new method for accurately detecting pathogenic bacteria of cholangitis after Kasai operation.

Implanted materials with both osteogenic and antibacterial functions are promising for facilitating osteointegration and preventing infection for orthopedic applications. In this work, we synthesized flower-like molybdenum disulfide (fMD) submicro-spheres containing nanosheets, which were incorporated onto the microporous surface of polyimide (PI)

Objective: The objective of the study is to explore a less invasive laparoscopic pyloromyotomy for treating infantile hypertrophic pyloric stenosis. Patients and Methods: A series of 154 cases from January 2014 to January 2020 were retrospectively analysed. Seventy patients were treated with the method of transumbilical single-site laparoscopic pyloromyotomy (SSLP), and 84 patients were treated with two-site laparoscopic pyloromyotomy. There was no difference in the body weight, sex ratio or age between the two groups. The operation time, blood loss, post-operative feeding time and complications between the two groups were compared. Results: The novel single-site method had better cosmetic effect than the two-site approach. There was no difference in the operation time, blood loss, post-operative feeding time or complications between the two groups. Conclusion: The novel SSLP method requires only two incisions through the umbilicus to complete the procedure, with barely visible scars and similar surgical complications to that of the two-site approach; thus, the novel method is worth promoting.

Objective Chylous ascites (CA) is a rare form of ascites that results from the leakage of lipid-rich lymph into the peritoneal cavity. In infants, CA is mostly caused by lymphatic malformation or unknown reasons. The creation of a shunt for the lymphorrhea is the last option for patients unresponsive to all other conservative treatments. Localization of the leakage is a critical problem during surgery. We applied a carbon nanoparticle suspension (CNS) in CA patients to locate the external lymphatic leakage and evaluated its utility during surgery. Patients and methods Twelve infants with CA were treated in our center recently. Ten patients received laparotomy, one refused therapy, and one was cured after undergoing conservative treatment. Recently, two infants with CA received CNS in the visceral peritoneum during laparotomy. The results of the traditional procedure were compared to our innovative technique for CA to evaluate the use of CNS in treating CA. Results The features of the baseline data did not differ substantially. Location of the leakage with CNS was employed in 2 of the 10 patients whose lymphatic leakages were identified with the resolution of the refractory CA. Overall, in 5 patients, ascites was resolved successfully. The refractory CA was resolved more effectively in patients in whom the leakage site was identified with CNS than in patients in whom the leakage site could not be identified under conventional surgery. Conclusions Injecting CNS improved the accuracy of lymphorrhagia leakage site identification and the outcomes of infants who underwent surgical treatment for refractory CA. Level of evidence II–III.

Malformation of digestive tract is common in neonates. Esophageal atresia (EA) comprises a group of congenital abnormalities defined by discontinuity of the esophagus. EA with communication with the trachea is known as tracheoesophageal fistula (TEF). For the repair of EA, it is needed to establish an anastomosis between two structures that may be significantly spaced apart, such as in long-gap EA (with a gap >3 cm). The repair across a long-gap can induce tension on the anastomosis, leading to dehiscence, anastomotic leak, or procedure failure. In neonatal patients with long-gap EA with TEF, the complications of significant gastroesophageal reflux, or anastomotic leaks and severe refractory esophageal stricture after surgery are common, which remains challenging for pediatric surgery. There are multiple options for lengthening and approximating the ends in long-gap EA such as myotomies, Gough flap, or the Foker technique. The treatment of long gap EA usually requires thoracotomy or thoracoscopy to place traction sutures on each esophageal in multiple stage operations, the treatment period of which is long. Esophageal stricture is the most common complication following EA repair. Refractory esophageal anastomotic stricture after repair of EA in infants is a challenging surgical problem. In general, these strictures can be successfully managed using endoscopic techniques including bougie and balloon dilation, stenting, and chemotherapeutic agents. If these techniques are unsuccessful, treatment options are limited to surgical resection of the strictured segment and reanastomosis, or esophageal replacement. Magnetic compression anastomosis (MCA) has been introduced for several decades. Recently, rare-earth magnets have been employed to create solid anastomosis for long-gap EA and refractory esophageal stricture in children. In MCA, a sutureless anastomosis of the gastrointestinal tract can be formed using two magnetic Harrison rings. Magnetic compress has been shown to be effective for the treatment of long-gap EA in children. MCA can be conducted during the same stage surgery of ligating the TEF with customized magnetic rings. Under the magnetic force, the two magnetic rings pull along the gastric tube to achieve anastomosis. Once the postoperative permanent suction of these two pouches is instituted, spontaneous growth can be awaited. MCA has been shown to be effective in anastomosis of stomach, small bowel and colon in both experimental and clinical cases. The magnets are most commonly made of neodymium-boron or samarium-cobalt, which can display strengths significantly greater than those of ferrite. Magnetic compression has been used to treat biliary strictures in adult patients who have undergone liver transplantation, as magnetic connectors for coronary surgery, and for the functional undiversion of ileostomy in pediatric patients. Reports also describe the use of magnetic compression in restoring patency of anastomotic strictures of the alimentary tract in patients who have undergone surgery for esophageal, gastric, and rectal cancer. Yamanouchi and colleagues have published many papers on their experience with Samarium cobalt magnets. They even used them to treat recurrent anastomotic strictures after initial MCA. It has been reported that in conditions such as congenital oesophageal atresia or rectal atresia in children, and also is a safe, minimally invasive way to gradually refunctionalize the excluded distal bowel after previous diverting ostomy. MCA using mated magnets with their interposed compressed tissue may result in serosa-to-serosa apposition. At present, MCA for the treatment of EA patients is restricted to gross type A (without TEF) and anastomotic stenosis without thoracotomy. Magnamosis offers a minimally invasive technique for repair of this congenital anomaly. This is particularly helpful in those patients who cannot undergo initial or repeat thoracotomy or thoracoscopy due to anatomic considerations or overall severity of illness. Translumenal digestive tract anastomosis using the constant magnetic field is reliable and feasible as a minimally invasive technique to treat congenital esophageal and anorectal abnormalities. Magnamosis is technically feasible for esophago-esophageal anastomoses. In anorectal malformations with favorable anatomy, this procedure may avoid an operative repair such as posterior sagittal reconstruction. We propose that magnamosis can be considered as an alternative for the treatment of rectal atresia in certain children.

Necrotizing enterocolitis (NEC) is a major cause of mortality and morbidity in newborns, characterized by inflammatory intestinal necrosis. Sirtuin-1 (SIRT1), a NAD-dependent deacetylase, is involved in multiple biological functions. It has been reported that SIRT1 was downregulated in NEC tissues. However, the precise role of SIRT1 in NEC progress remains unknown. In this study, we found that SIRT1 was decreased in serum samples of NEC patients, associated with an inflammation response. an in vitro model was established by using LPS-induced NEC-like cell in this study. The results indicate that overexpression of SIRT1 inhibited the cell apoptosis induced by LPS. Besides, overexpression of SIRT1 suppressed the high expression of proinflammatory factors (IL-6, IL-8, and TNF-α), the decrease of transepithelial electrical resistance (TEER), and the decline expression of tight junction proteins (ZO-1, ZO-2, and Claudin-4) induced by LPS in Caco-2 cells. What is more, serum HIF-1α was increased in NEC patients. SIRT1 overexpression suppressed the expression and activity of HIF-1a, while knockdown of SIRT1 made the opposite effect. In summary, this study indicates that overexpression of SIRT1 alleviates the inflammation response and intestinal epithelial barrier dysfunction through regulating the expression and inactivation of HIF-1a.

To improve the antibacterial and osteogenic activities of poly(etherketoneketone) (PEKK), concentrated sulfuric acid (H2SO4) suspension with silicon nitride (SN) microparticle was utilized to modify PEKK surface. Through sulfonation reaction, microporous coatings of PEKK/SN composites were created on PEKK surface, which were integrated with PEKK substrate. The results showed that the content of SN in the microporous coatings increased with the increase of SN content in H2SO4 suspension (PKS without SN, PKSC5 and PKSC10 with 5 and 10 wt % SN content in H2SO4) and that the surface roughness and hydrophilicity of microporous coatings on PEKK were significantly improved with the SN content increasing. In addition, the microporous coating of PKSC10 with high SN content exhibited excellent antibacterial activity due to the synergistic action of the presence of amino (-NH2) and sulfonic acid (-SO3H) groups as well as the improvement of protein absorption. Moreover, the microporous coating of PKSC10 obviously stimulated adhesion, proliferation, and osteogenic differentiation of rat bone mesenchymal stem cells. Furthermore, histological and push-out load evaluation indicated that the microporous coating of PKSC10 significantly promoted osteogenesis and osseointegration in vivo. The results suggested that the microporous coating of PKSC10 with high SN content display good biocompatibility, antibacterial and osteogenic activities, and osseointegration ability, which would have great potential for bone substitutes.

Bone implants of polyetheretherketone (PEEK) have become increasingly popular in the orthopedic field but its bioinertness and poor osteogenic properties significantly limit its applications for bone regeneration and osseointegration with host bone. In this study, by incorporation of mesoporous diopside (MD) into the PEEK matrix, macro-mesoporous PEEK/MD (PM) composites as bone implants with interconnected macropores of 300–400 μm were fabricated using the method of cold press-sintering and salt-leaching. The results showed that the compressive strength, porosity and water absorption of the porous PM composites significantly increased with an increase in the MD content. In addition, the incorporation of MD into PEEK obviously enhanced the mineralization ability of the PM composites, indicating good bioactivity. Moreover, the in vitro cell experiments indicated that the macro-mesoporous PM composites significantly promoted the adhesion and proliferation as well as osteogenic differentiation of MC3T3-E1 cells, which depended on the MD content. The results of synchrotron radiation-based micro-computed tomography (SRmCT) and histological analysis revealed that the porous PM composites possessed excellent osteogenic properties in vivo, which were obviously enhanced with an increase in the MD content. Moreover, the immunohistochemistry evaluation of type I collagen (COL I) and vascular endothelial growth factor (VEGF) confirmed that addition of MD into PEEK obviously enhanced the osteogenesis and vascularization potential of the macro-mesoporous PM composites in vivo. The results suggested that the PM composites containing macropores and mesopores as bone implants had great potential for bone repair/substitution.

Poor osteogenesis and bacterial infection lead to the failure of implants, thus enhancements of osteogenic activity and antibacterial activity of the implants have significances in orthopedic applications. In this study, macro-microporous bone implants of nano-bioglass (nBG) and polyetheretherketone (PK) composite (mBPC) were fabricated. The results indicated that the mBPC with the porosity of around 70% exhibited interconnected macropores (sizes of about 400 μm) and micropores (sizes of about 10 μm). The apatite mineralization ability of mBPC in simulated body fluid (SBF) was significantly improved compared with macroporous nBG/PK composite (BPC) without micropores and macroporous PK (mPK). Drug of hinokitiol (HK) was loaded into mBPC (dmBPC), which displayed excellent in vitro antibacterial activity against Staphylococcus aureus. The MC3T3-E1 cells proliferation and ALP activity were significantly promoted by mBPC and dmBPC as compared with BPC and mPK. The micro-CT and histological evaluation showed that both mBPC and dmBPC containing nBG and micropores induced higher new bone formation into porous implants than mPK and BPC. The immunohistochemistry analysis indicated that the expression of BMP-2 in mBPC and dmBPC exhibited obviously higher level than mPK and BPC. The results suggested that the incorporation of nBG and micropores in mBPC obviously improved the osteogenic activity, and mBPC load with HK also promoted osteogenesis, indicating good biocompatibility. The dmBPC with HK significantly enhanced osteogenesis and antibacterial activity, which had great potential as bone implant for hard tissue repair.

Silicon nitride (SN) with good osteoconductivity has been introduced as an implantable biomaterial for joint replacement and interbody fusion devices. In this study, SN was coated on a polyetheretherketone (PEEK) surface by inductively coupled plasma-enhanced chemical vapor deposition (ICPECVD). The results showed that a dense coating (thickness of about 500 nm) of amorphous SN was closely combined with a PEEK substrate (PKSN) with a binding strength of 6.88 N. In addition, the coating surface showed hierarchical nanostructures containing many spherical bulges (sizes about 150 nm), which were composed of many small humps (sizes about 10 nm). Moreover, the roughness, hydrophilicity, surface energy, surface charge and adsorption of bovine serum albumin (BSA) of PKSN were obviously higher than those of PEEK. After immersion into simulated body fluid (SBF), the Si ions were gradually released from PKSN into SBF and a weak alkaline environment was created. Antibacterial experiments showed that PKSN exhibited a greater antibacterial activity than that of PEEK. Moreover, compared with PEEK, PKSN significantly promoted adhesion, proliferation, differentiation and expression of osteogenic related genes of the rat bone marrow stromal cells (rBMSCs). In conclusion, the SN coating of PKSN with hierarchical nanostructures exhibited excellent antibacterial activity and cytocompatibility, which would make it a great candidate for orthopedic applications.

Poor cell adhesion and osteogenic activity impede the bone regeneration and osseointegration effects of polyetherketoneketone (PEKK) implants. Surface modification and incorporation of bioactive fillers are effective strategies to promote the cellular responses of PEKK implants and their integration with bone tissues. In this study, silicon nitride (SN) microparticles were blended with PEKK to develop bioactive composite implants (SPC). Femtosecond laser was then used to modify SPC surfaces inducing favorable micro/nano structural surface (FSPC). After the laser ablation, irregularly shaped SN microparticles were converted to “petal-like” clusters composed of “pin-like” SN nanoparticles, while the entire surface was covered by SN particles due to the removal of PEKK. The roughness, hydrophilicity, content of surface chemical groups (e.g., -NH2), and protein adsorption capability of FSPC were significantly enhanced compared to SPC and PEKK. Also, the release of biologically active Si ions was increased after the femtosecond laser treatment, inducing a positive microenvironment favorable for cellular activities. Moreover, FSPC exhibited a greater bacteriostatic activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) than SPC. The presence of micro/nano structure also remarkably promoted adhesion, proliferation, and osteogenic differentiation of rat bone mesenchymal stem cells (rBMSCs). In vivo evaluation of the composites in a rabbit femur defect model verified that FSPC could enhance osteogenesis and osseointegration to a greater extent than SPC, evidenced with greater bone-implant contacts and push-out force. These results indicate that the femtosecond laser induced micro/nano structural surface on SN/PEKK implants can significantly promote osseointegration and bone repair. The femtosecond laser exhibits great potential in surface modifying bioceramic/polymer composites. The fabricated FSPC have shown great potential as bone implants in orthopedic applications considering their excellent biocompatibility, bacteriostatic property, osteogenic activity, and osseointegration.

Polyetheretherketone (PEEK) biomaterial has become increasingly popular in orthopedic applications due to its favorable biocompatibility, biostability, mechanical strength and elastic modulus similar to natural bones. In this research, in order to improve the biological performances of PEEK, tantalum pentoxide (Ta2O5) was incorporated into PEEK to fabricate PEEK/Ta2O5 composites (PTC) using a method of cold press-sintering, and surface coarsening of PTC was prepared by sand blasting. The results showed that the Ta2O5 particles were uniformly disperse into PEEK, and thermal and mechanical properties of PTC were enhanced with the increase of Ta2O5 content. In addition, incorporating Ta2O5 into PEEK and surface coarsening could improve surface roughness, hydrophilicity, surface energy and protein absorption of PTC. Furthermore, the adhesion and proliferation as well as osteogenic differentiation of BMSCs on PTC were significantly promoted and regulated by Ta2O5 content and surface coarsening. The results indicated that surface coarsening of PTC (PTCS) with high surface roughness, hydrophilicity and surface energy could induce positive cellular responses, showing good cytocompatibility. PTCS might have a great potential as implants for bone repair.

Polyimide (PI) may become a promising biomaterial for dental and orthopedic application due to its high mechanical strength, good biocompatibility and bio-stability as well as modulus of elasticity similar to the bone of human body. In this study, bioactive tantalum pentoxide (Ta2O5, TO)/polyimide (PI) composites (TPC) were fabricated by blending modification through a process of cold-pressing and sintering. The results revealed that the compressive strength, thermal stability, surface roughness, hydrophilicity and surface energy of TPC were significantly enhanced with the increase of TO content. Moreover, apatite mineralization of TPC in simulated body fluid (SBF) was obviously improved, in which TPC with TO of 50 wt% content (TPC50) displayed the best bioactivity. Furthermore, the cellular responses (adhesion, proliferation and differentiation) of rat bone mesenchymal stem cells (rBMSCs) to TPC were obviously upregulated with the increase of TO content. The results demonstrated that the TO content in the composites remarkably affected not only physical-chemical properties but also the cells behaviors. It can be suggested that TPC50 with improved surface properties and bioactivity as well as good cytocompatibility would have great potential and prospect for dental and orthopedic applications.

Efficacious hemostatic agents have significant potential application in visceral organ or large vessel arterial injure. In this study, mesoporous zinc-calcium silicate (m-ZCS) was synthesized, and microporous starch (MS) based hemostatic agents of m-ZCS/MS composites for hemorrhage control was fabricated. The results showed that the incorporation of m-ZCS into MS significantly enhanced the water absorption and degradability of the composites, which were dependent on the m-ZCS content. Moreover, the composites with antibacterial property could inhibit the growth of Escherichia coli (E. coli) and the antibacterial ratios increased with the m-ZCS content. The in vitro coagulation evaluation by using activated partial thromboplastin time (APTT) and prothrombin time (PT) revealed that the composites significantly activated the intrinsic and extrinsic pathway of coagulation cascade. In addition, for the animal model of rabbits in ear vein, skin, arterial and liver injuries, the hemostatic time of the composites obviously reduced with the increase of m-ZSC content, in which the composite with 15wt% m-ZCS content (15mZSC) showed remarkable efficacy on bleeding control. The composites could promote the viability of L929 cells, indicating no cytotoxicity of the composites. The results suggested that the m-ZCS/MS composites with excellent hemostatic and antibacterial properties might be a candidate for controlling bleeding and infection.

Glycerol-plasticized wheat gluten was prepared by mixing in an internal mixer equipped with sigma rotors, and then thermally compression-molded to form a sheet for crosslinking and tensile tests. Referring to rubber vulcanization process, rotorless curemeter was applied to test the vulcanization characteristic parameters of the molded round samples, which could be used to calculate the activation energy and reaction rate of crosslinking occurring in wheat gluten when heated. Vulcanizing curves obtained show that the optimum temperature for processing glycerol-plasticized wheat gluten is 150°C, and that activation energy and reaction rate of crosslinking in wheat gluten plasticized with 20 wt % glycerol reach minimum and maximum values, respectively. In addition, glycerol content, plasticizing time, and temperature have significant effects on the mechanical properties of thermomolded wheat gluten plastics. The factors are closely related to the establishment of a covalent network resulting from the formation and rearrangement of disulfide bridges in wheat gluten. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Wheat gluten (WG) and Attapulgite (ATP) was mixed in acidic solution and freeze-dried, thermally compression-molded to form nanocomposite sheet. The influences of reduction and sonication on structure of wheat gluten were examined by Raman spectrum. The variation of disulfide bonding in wheat gluten show that the sonication is more effective than reduction on the breakage of disulfide bonds, whereas the content of disulfide bonds in the WG sheet molded by sonicated WG powder is the highest in the molded sheets. FT-IR analysis displays that the bands in the range of 1700–1600 cm −1 shift to higher frequency after mixing WG and ATP powders and molding the nanocomposite. The tensile and bending properties of the WG sheet increase with addition of ATP powder, and the properties of the sheet molded by sonicated WG powder decrease for the reduction of the disulfide bonding, but the properties of the sheet can be improved by addition of ATP. The WG/ATP nanocomposite images observed by SEM and TEM show that rod-like ATP particles are evenly dispersed in WG matrix, but the crystal structure of ATP is impervious. The viscoelasticity of the WG sheet declines with addition of ATP particle, and that the α-relaxation of the WG sheet molded by sonicated WG powder shift to high temperature and become broad. Both mass and bending strength of 7 wt% WG/ATP nanocomposite sheet show a decline over a soil exposure time of 20 days.

In the present study, salt granules were dried in a fluidized-bed dryer and suitable technologic parameters of drying operation were obtained. The air distributing structure of fluidized bed dryer was studied and its pressure drop curve was measured. The results indicated that one layer of intertexture net below the air distributing board could produce good air distribution without increase of pressure drop. This kind of structure could also prevent the material from leaking.

A novel bioactive composite based on wheat protein (WP) and mesoporous magnesium silicate (m-MS) with a high specific surface area is presented in this study for potential bone tissue regeneration. Wheat protein (WP) is a type of a biodegradable natural polymer material. The m-MS was prepared by the sol–gel technique, which was incorporated into WP to fabricate m-MS/WP composites. The increasing amount of m-MS improved the surface hydrophilicity of m-MS/WP composites. The results showed that the degradation ratio of the m-MS/WP composites increased with an increase in the m-MS content after it was soaked in a Tris–HCl solution for 12 weeks. Moreover, the m-MS/WP composites with 40 wt% m-MS content (WP40) were able to maintain a suitable pH value over a prolonged soaking time, which might be dependent on the content of the m-MS. The WP40 showed a good apatite formation ability after it was soaked in simulated body fluid (SBF) for 7 days, indicating good bioactivity. Moreover, the WP40 with cytocompatibility stimulated the attachment, proliferation and differentiation of MC3T3-E1 osteoblast cells. Briefly, the results indicated that WP40 had good bioactivity, degradability, cytocompatibility and osteogenesis and might be a new biomaterial for bone regeneration.

Revolving air flow was generated by oblique holes on air distribution board in a fluidized bed dryer. Such a revolving air flow shows a large scale velocity fluctuation in radial as well as tangential directions. This turbulent flow of air can fluidize the inert particles with superior performance than vibrated fluidized bed. The revolving fluidized bed is simpler in fabrication and easier in operation. For two types of inert particles tested, 4 mm glass beads and 4 mm × 5 mm Teflon cylindrical extrudates, the volumetric heat transfer coefficients were found to increase with the liquid feed flowrate and air flow velocity but decrease with the air inlet temperature, height of static bed, and liquid concentration. The revolving fluidized bed gives an increase of volumetric heat transfer coefficient by 1 kW/m3 K, and represents a 15–25% enhancement from ordinary fluidized bed operated at a bed height of 60 mm, bed diameter of 140 mm, superficial air flow velocity of 3.5 m/s, liquid feed (Soya milk) ...

Several vegetables and fruits, apple, ginger, carrot, and pumpkin were dehydrated under various osmotic conditions using sucrose and salt as the permeating agents. The dehydrated materials were then dried. The influence of solute concentration, process temperature and the type of solute on osmotic dehydration and further thermal drying were investigated. The nutrition loss during the osmotic process was measured using carotene as the nutrition index. The effect of calcium chloride present in osmotic solution on the product quality was also studied. A first order kinetic model was chosen to describe the mass transfer phenomena of the osmotic process. The equilibrium value of water loss, solute gained, kinetic constants K WL and K SG under various conditions are successfully predicted by the model. The relationship between the equilibrium value and four major factors that influence osmotic process of carrot was obtained based on the experimental data. The relations between the loss constant of caro...

Free-radical grafting of glycidyl methacrylate (GMA) onto polypropylene (PP) powder was studied in a batch mixer. The reaction temperature was below the melting point of PP so that PP was modified in the solid phase. The graft yield of GMA obtained under various experimental conditions allowed for a good appreciation of the effects of chemical parameters (the concentration of monomer, initiator, and interfacial agent) and those of processing parameters (reaction time and temperature). Toluene was used as an interfacial agent to etch the surface of PP powder to provide more sites for reaction. Quantitative determination of the graft level was performed by wet chemical methods. The results showed that the solid-phase grafting could take place over a temperature range of 100–140°C in the initiation of benzoyl peroxide (BPO). The ultimate GMA grafting level achieved was higher than that obtained in the melt state with dicumyl peroxide (DCPO) as a radical initiator. The grafting of GMA affected the crystalline morphology of PP and speeded up the crystallization process. The energy of activation and initial decomposition temperature of grafted samples were higher than those of ungrafted PP. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65: 1905–1912, 1997

Experimental results on the drying characteristics in a vibrated fluidized bed IVFB) for sticky and agglomerating materials under various conditions of the operating parameters are presented.The dynamics of the \'FB of wetted materials and the effects of parameters, such as vibration amplitude and frequency, initial moisture content, initial bed height, particle size, and air velocity and temperature on the drying rate during the constant rate period were studied experimentally.