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Abstract Background Crosslinked gelatin nanofibers are one of the widely used scaffolds for soft tissue engineering. However, modifying the biodegradation rate of chemically crosslinked gelatin is necessary to facilitate cell migration and tissue regeneration. Here, we investigated the optimal electron beam (e-beam) irradiation doses with biodegradation behavior on changes in the molecular weight, morphology, pore structure, and cell proliferation profiles of electrospun nanofibrous gelatin sheets. Methods The molecular weights of uncrosslinked gelatin nanofibers were measured using gel permeation chromatography. The morphology and pore structure of the gelatin scaffolds were analyzed by scanning electron microscopy and a porosimeter. Biodegradation tests were performed in phosphate-buffered saline solutions for 4 weeks. Cell proliferation and tissue regeneration profiles were examined in fibroblasts using WST-1 assays and hematoxylin and eosin staining. Results Crosslinked gelatin nanofiber sheets exposed to e-beam irradiation over 300 kGy showed approximately 50% weight loss in 2 weeks. Gelatin scaffolds exposed to e-beam irradiation at 100–200 kGy showed significantly increased cell proliferation after 7 days of incubation. Conclusions These findings suggested that the biodegradation and cell proliferation rates of gelatin nanofiber scaffolds could be optimized by varying e-beam irradiation doses for soft tissue engineering.

Abstract Background In this study, silk fibroin (SF) composite hydrogels containing hydroxyapatite (HAP) nanoparticles (NPs) for bone tissue engineering were fabricated using gamma-ray (γ-ray) irradiation treatment. During the irradiation, the HAP dispersed SF solution was changed to the chemically crosslinked SF hydrogel. Methods Distribution of HAP NPs in the SF hydrogel was examined by SEM imagery and energy dispersive X-ray spectrophotometry, and the crystalline structure of SF composite hydrogels was also confirmed by X-ray diffractometry. An optimum preparation condition of the SF/HAP composite hydrogels was determined with various HAP contents. For evaluation of the osteogenic differentiation of human mesenchymal stem cells (hMSCs), alkaline phosphatase activity (ALP), HAP nucleation in SBF and in vitro calcium accumulation were measured. Results The results revealed that compared with the pure SF hydrogels, the SF/HAP composite hydrogels improved osteogenic differentiation. Conclusion This paper demonstrates the great potential of the SF/HAP composite hydrogels in terms of the production of the bone tissue engineering scaffolds for which osteogenesis is required.

Purpose Open pelvic bone fractures are relatively rare and are considered more severe than closed fractures. This study aimed to compare the clinical outcomes of open and closed severe pelvic bone fractures. Methods Patients with severe pelvic bone fractures (pelvic Abbreviated Injury Scale score, ≥4) admitted at a single level I trauma center between 2016 and 2020 were retrospectively analyzed. Patients aged

Pneumoperitoneum usually presents as a surgical emergency, especially in patients with a history of trauma. However, we recently encountered an atypical case of pneumoperitoneum at a hysterectomy site following blunt trauma, indicating that immediate laparotomy may not always be necessary. In this report, we present the case of a 45-year-old woman who was transferred to our trauma center from a local hospital after being involved in a traffic accident the day before. Although she underwent an emergency laparotomy, no bowel perforation was detected. Instead, a rupture was found at the site of a hysterectomy that had been performed 8 months earlier. After repairing the hysterectomy site, the pneumoperitoneum resolved, and the patient was subsequently discharged without further complications.

Abstract Background Hemorrhage control is a time-critical task, and recent studies have demonstrated that a shorter time to definitive care is positively associated with patient survival and functional outcomes. The concept of direct transport to the operating room was proposed in the 1960s to reduce treatment time. Some trauma centers have developed protocols for direct-to-operating room resuscitation (DOR) programs. Moreover, few studies have reported the clinical outcomes of DOR in patients with trauma; however, their clinical effect in improving the efficiency and quality of care remains unclear. In this systematic review, we aimed to consolidate all published studies reporting the effect of DOR on severe trauma and evaluate its utility. Methods The PubMed, EMBASE, and Cochrane databases were searched from inception to April 2023, to identify all articles published in English that reported the effect of direct-to-operating room trauma resuscitation for severe trauma. The articles were reviewed as references of interest. Results We reviewed six studies reporting the clinical effect of operating room trauma resuscitation. A total of 3232 patients were identified. Five studies compared the actual mortality with the predicted mortality using the trauma score and injury severity score, while one study compared mortality using propensity matching. Four studies reported that the actual survival rate for overall injuries was better than the predicted survival rate, whereas two studies reported no difference. Some studies performed subgroup analyses. Two studies showed that the survival rate for penetrating injuries was better than the predicted survival rate, and one showed that the survival rate for blunt injuries was better than the predicted survival rate. Five studies reported the time to surgical intervention, which was within 30 min. Two studies time-compared surgical intervention, which was shorter in patients who underwent DOR. Conclusion Implementing DOR is likely to have a beneficial effect on mortality and can facilitate rapid intervention in patients with severe shock. Future studies, possibly clinical trials, are needed to ensure a proper comparison of the efficiency.

Retrohepatic vena cava (RHIVC) injury is often fatal and can be very difficult to manage. Total hepatic vascular isolation, a shunt, or bypass surgery is required for the surgical treatment of RHIVC injury in hemodynamically unstable patients; however, these are not easy procedures. Here, we present a case of RHIVC injury that was successfully treated by atriocaval shunt placement via a transdiaphragmatic incision without sternotomy or thoracotomy. In addition, we review the resuscitation and surgical procedures used for total hepatic vascular isolation in patients with RHIVC injury.

Recently, numerous compounds have been studied in order to develop antibacterial agents, which can prevent colonized wounds from infection, and assist the wound healing. For this purpose, novel silver chloride nanoparticles stabilized with chitosan oligomer (CHI-AgCl NPs) were synthesized to investigate the influence of antibacterial chitosan oligomer (CHI) exerted by the silver chloride nanoparticles (AgCl NPs) on burn wound healing in a rat model. The CHI-AgCl NPs had a spherical morphology with a mean diameter of 42 ± 15 nm. The burn wound healing of CHI-AgCl NPs ointment was compared with untreated group, Vaseline ointment, and chitosan ointment group. The burn wound treated with CHI-AgCl NPs ointment was completely healed by 14 treatment days, and was similar to normal skin. Particularly, the regenerated collagen density became the highest in the CHI-AgCl NPs ointment group. The CHI-AgCl NPs ointment is considered a suitable healing agent for burn wounds, due to dual antibacterial activity of the AgCl NPs and CHI. [ABSTRACT FROM AUTHOR]

In the present work, a multi-functional monomer triallyl isocyanurate (TAIC) of 4 wt.% is incorporated into neat poly(butylene succinate) (PBS) by twin screw extrusion technique and the PBS sheets are irradiated at various electron beam absorption doses. It has been found that electron beam irradiation at an appropriate absorption dose plays an effective role in crosslinking the PBS molecules in the presence of TAIC. As a result, the irradiation influences the gel fraction, glass transition temperature, thermal stability, thermo-dimensional stability, dynamic storage modulus, and tensile properties of PBS, depending on the electron beam absorption dose applied. The improvement of the thermal and mechanical properties of PBS is most significant in the range of 50 to 70 kGy. The results are consistent with each other, supporting the electron beam irradiation effect on the property improvement of PBS. [ABSTRACT FROM AUTHOR]

Background We hypothesized that the recent change of sepsis definition by sepsis-3 would facilitate the measurement of timing of sepsis for trauma patients presenting with initial systemic inflammatory response syndrome. Moreover, we investigated factors associated with sepsis according to the sepsis-3 definition. Methods Trauma patients in a single level I trauma center were retrospectively reviewed from January 2014 to December 2016. Exclusion criteria were younger than 18 years, Injury Severity Score (ISS)

Rapid cell growth and rapid recovery of intact cultured cells are an invaluable technique to maintain the biological functions and viability of cells. To achieve this goal, thermoresponsive polystyrene (PS) nanofibrous mat was fabricated by electrospinning of PS solution, followed by the graft polymerization of thermoresponsive poly(N-isopropylacrylamide)(PIPAAm) on PS nanofibrous mats. Image analysis of the PS nanofiber revealed a unimodal distribution pattern with 400nm average fiber diameter. Graft polymerization of PIPAAm on PS nanofibrous mats was confirmed by spectroscopic methods such as ATR-FTIR, ESCA, and AFM. Human fibroblasts were cultured on four different surfaces, PIPAAm-grafted and ungrafted PS dishes and PIPAAm-grafted and ungrafted PS nanofibrous mats, respectively. Cells on PIPAAm-grafted PS nanofibrous mats were well attached, spread, and proliferated significantly much more than those on other surfaces. Cultured cells were easily detached from the PIPAAm-grafted surfaces by decreasing culture temperature to 20°C, while negligible cells were detached fromungrafted surfaces.Moreover, cells on PIPAAm-grafted PS nanofibrous mats were detached more rapidly than those on PIPAAm-grafted PS dishes.These results suggest that thermoresponsive nanofibrous mats are attractive cell culture substrates which enable rapid cell growth and recovery from the culture surface for application to tissue engineering and regenerative medicine. [ABSTRACT FROM AUTHOR]

The mechanical stability of titania (TiO2) nanofibers was improved by fabricating TiO2/poly(dimethyl siloxane) (PDMS) composite fibers using a combination of hybrid electrospinning and sol-gel methods, followed by heat treatment at 250°C for 3 h. The compositions (90/10, 80/20, and 70/30, w/w) of the TiO2/PDMS composite fibers were varied by adjusting the flow rate of the PDMS sol with the flow rate of TiO2 sol fixed. There was no significant change in morphology and average diameter of the as-spun TiO2/PDMS fibers after heat treatment. Both the tensile strength and modulus of the TiO2/PDMS composite fibers increased gradually with increasing PDMS content up to 30 wt %. In addition, from the photo-degradation reaction of methylene blue, the photocatalytic activity of TiO2/PDMS composite fibers was strongly dependent on the TiO2 content (%) in the composite fibers. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [ABSTRACT FROM AUTHOR]

In this study, polycardanol, which was synthesized by enzymatic oxidative polymerization of thermally treated cashew nut shell liquid (CNSL) using fungal peroxidase, was partially or fully cured using methyl ethyl ketone peroxide (MEKP) as initiator and cobalt naphthenate (Co-Naph) as accelerator. The curing behavior of polycardanol was extensively investigated in terms of curing temperature, curing time, concentration of initiator and accelerator, and the monomer-to-polymer conversion of polycardanol by means of differential scanning calorimetry (DSC). The curing behavior significantly depends on the thermal condition given and it was monitored with the change of the exotherms as a function of temperature. The optimal conditions for fully curing polycardanol are 1 wt% MEKP, 0.2 wt% Co-Naph, curing time 120 min, and curing temperature 200 °C. This study suggests that a polycardanol with high monomer-to-polymer conversion would be useful for processing a polycardanol matrix composite under the optimal conditions of curing. [ABSTRACT FROM AUTHOR]

The surfaces of kenaf fibers were treated with three different silane coupling agents. 3-glycidoxypropyltrimethoxy silane (GPS), 3-aminopropyltriethoxy silane (APS), and 3-methacryloxypropyltrimethoxy silane (MPS). Among them, the most effective one for the property improvement was GPS when it was applied to the kenaf fiber surfaces at 0.5 wt%. Thermoplastic polypropylene (PP) and thermosetting unsaturated polyester (UPE) matrix composites with chopped kenaf fibers untreated and treated at different GPS concentrations from 0.1 wt% to 5 wt% were fabricated using compression molding technique. The present study demonstrates that the interfacial, flexural, tensile, and dynamic mechanical properties of both kenaf/PP and kenaf/UPE composites importantly depend on the GPS treatments done at different concentrations. The greatest property improvement of both thermoplastic and thermosetting polymer composites was obtained with the silane treatment at 0.5 wt% and the mechanical properties were comparable with E-glass composites prepared the same polymer matrix under the corresponding fiber length and fiber loading. The results also agreed with each other with regard to their interfacial shear strength, flexural properties, tensile properties, storage modulus, with support of fracture surfaces of the composites. [ABSTRACT FROM AUTHOR]

In the present study, novel biocomposites with chopped jute fibers and thermosetting polycardanol were prepared using compression molding technique for the first time. Prior to biocomposite fabrication, jute fiber bundles were surface-treated at various concentrations using 3-glycidoxypropyltrimethoxy silane (GPS) and 3-aminopropyltriethoxy silane (APS), respectively. The interfacial shear strength, flexural properties and thermal properties of jute/polycardanol biocomposites reinforced with untreated and silane-treated jute fibers were investigated by means of single fiber microbonding test, three-point flexural test, dynamic mechanical analysis, thermogravimetric analysis and thermomechanical analysis. Both GPS and APS treatments played a role in improving the interfacial adhesion, reflecting that the organofunctional groups located at the end of silane coupling agents may contribute to linking between jute fibers and a polycardanol resin. As a result, it gave rise to increased interfacial shear strength of the biocomposites. Such interfacial improvement also led to increasing the flexural strength and modulus, storage modulus, thermal stability and thermomechanical stability. [ABSTRACT FROM AUTHOR]

In the present study, natural fibers (jute, kenaf and henequen) reinforced thermoplastic (poly(lactic acid) and polypropylene) and thermosetting (unsaturated polyester) matrix composites were well fabricated by a compression molding technique using all chopped natural fibers of about 10 mm long, respectively. Prior to green composite fabrication, natural fiber bundles were surface-treated with tap water by static soaking and dynamic ultrasonication methods, respectively. The interfacial shear strength, flexural properties, and dynamic mechanical properties of each green composite system were investigated by means of single fiber microbonding test, 3-point flexural test, and dynamic mechanical analysis, respectively. The result indicated that the properties of the polymeric resins were significantly improved by incorporating the natural fibers into the resin matrix and also the properties of untreated green composites were further improved by the water treatment done to the natural fibers used. Also, the property improvement of natural fiber-reinforced green composites strongly depended on the treatment method. The interfacial and mechanical results agreed with each other. [ABSTRACT FROM AUTHOR]

In the present study, chopped henequen natural fibers without and with surface modification by electron beam (E-beam) treatment were incorporated into a polypropylene matrix. Prior to composite fabrication, a bundle of raw henequen fibers were treated at various E-beam intensities from 10 kGy to 500 kGy. The effect of E-beam intensity on the interfacial, mechanical and thermal properties of randomly oriented henequen/polypropylene composites with the fiber contents of 40 vol% was investigated focusing on the interfacial shear strength, flexural and tensile properties, dynamic mechanical properties, thermal stability, and fracture behavior. Each characteristic of the material strongly depended on the E-beam intensity irradiated, showing an increasing or decreasing effect. The present study demonstrates that henequen fiber surfaces can be modified successfully with an appropriate dosage of electron beam and use of a low E-beam intensity of 10 kGy results in the improvement of the interfacial properties, flexural properties, tensile properties, dynamic mechanical properties and thermal stability of henequen/polypropylene composites. [ABSTRACT FROM AUTHOR]

Thermal and dynamic mechanical properties of kenaf natural fiber reinforced polypropylene (PP) biocomposites were examined to compare the effects of natural fiber treatment by electron beam irradiation (EBI) and alkalization. The alpha cellulose contents, the functional groups on the surfaces and the thermal stability of the untreated and treated kenaf fibers were studied. Kenaf fiber/polypropylene(PP) biocomposites were fabricated by means of a compression molding technique using chopped kenaf fibers treated with electron beam (EB) dosages of 100, 200, 500 kGy or with NaOH concentrations of 2, 5, 10 wt%, respectively. The thermal stability, the dynamic mechanical and the interfacial properties of untreated and treated kenaf/PP biocomposites were also investigated through a thermogravimetric analysis, a dynamic mechanical analysis and a fractographic observation, respectively. The results show that the characteristics of kenaf fibers and biocomposites depended on the different treatment level with the EB dosages or on the NaOH concentrations used. In this study, the modification of kenaf fiber surfaces at 200 kGy EBI and treatment with 5 wt% NaOH was most effective for improving the performance of kenaf/PP biocomposites. This study suggests that EBI can be used for modification of natural fiber as an environmentally friendly process and contribute to an improvement in the performances of kenaf/PP biocomposites. [ABSTRACT FROM AUTHOR]

The dynamic mechanical thermal properties of carbon fiber-reinforced bismaleimide (BMI) composites processed using polyacrylonitrile(PAN)-based carbon fibers unsized and sized with LaRC PETI-5 amic acid oligomer as interphase material at 150°C, 250°C, and 350°C were investigated by means of dynamic mechanical thermal analysis. It was found that the storage modulus, loss modulus, tan δ and the peak temperature significantly depend on the sizing temperature as well as on the presence and absence of LaRC PETI-5 sizing interphase. The result showed that the carbon fiber/BMI composite sized at 150°C had the highest storage modulus at a measuring temperature of 250°C. The storage modulus decreased with increasing sizing temperature from 150°C to 350°C, being influenced by interdiffusion and co-reaction between the LaRC PETI-5 interphase and the BMI matrix resin. The present result is quite consistent with the interfacial result reported earlier in term of interfacial shear strength and interlaminar shear strength of carbon fiber/BMI composites. It is addressed that in the present composite system the sizing temperature of LaRC PETI-5 interphase critically influences not only the interfacial properties but also the dynamic mechanical thermal properties and its control is also important. [ABSTRACT FROM AUTHOR]

Henequen natural fiber-reinforced poly(butylene succinate) biocomposites were prepared through a resin microdroplet formation on a single fiber and also fabricated by a compression molding technique using chopped henequen fibers, surface-treated with electron beam irradiation (EBI) at various dosages. The effect of EBI treatment on the surface characteristics and dynamic mechanical properties of henequen fibers was investigated using SEM, XPS and DMA methods, respectively. Also, the interfacial behavior of biocomposites was explored through a single fiber microbonding test and fracture surface observations. The result indicates that the interfacial shear strength (IFSS) of biocomposites greatly depends on the EBI treatment level on the henequen fiber surface. This study also suggests that appropriate modification of natural fiber surfaces at an optimum EBI dosage significantly contributes to improving the interfacial properties of biocomposites. [ABSTRACT FROM AUTHOR]

Presents a letter to the editor regarding the expansion behavior of intercalated graphite flake.

A phenylethynyl-terminated imide oligomer (LaRC PETI-5®) with a number average molecular weight of 25OO g / mol has been applied onto the surfaces of PAN-based carbon fiber tows and woven carbon fabrics as a sizing material to introduce an interphase between the fiber and matrix in carbon/BMI composites. The adhesion between the fiber and matrix was enhanced by the presence of a properly processed LaRC PETI-5® interphase. The results showed that when LaRC PETI5® was sized and processed at 150°C, the interfacial shear strength (IFSS) of unidirectional IM7/BMI composite measured by using a microindentation technique and the interlaminar shear strength (ILSS) of a carbon/BMI composite measured by short beam shear test were markedly improved by about 35% and 66%, respectively, in comparison with the unsized counterparts. The adhesion enhancement strongly depends not only on the presence or absence of LaRC PETI5° sizing interphase but also on the temperature profile applied to the sizing before composite fabrication. Both of these factors critically influence the physical and chemical state of the sizing material. Scanning electron microscopic observations of the composite fracture surfaces support the improved interracial property of carbon/BMI composites. [ABSTRACT FROM AUTHOR]

Examines the possibility of synthesizing polyimide/organo-montmorillonite (MMT) nanocomposites by a solution intercalation process. Effects of synthesis on thermal, mechanical and gas barrier properties; Effects of different alkyl-MMT on mechanical and gas barrier properties.

An indole-based fluorescent chemosensor IH-Sal was synthesized to detect Zn2+. IH-Sal displayed a marked fluorescence increment with Zn2+. The detection limit (0.41 μM) of IH-Sal for Zn2+ was greatly below that suggested by the World Health Organization. IH-Sal can quantify Zn2+ in real water samples. More significantly, IH-Sal could determine and depict the presence of Zn2+ in zebrafish. The detecting mechanism of IH-Sal toward Zn2+ was illustrated by fluorescence and UV–visible spectroscopy, DFT calculations, 1H NMR titration and ESI mass.

A novel thiosemicarbazide-based fluorescent sensor (AFC) was developed. It was successfully applied to detect hypochlorite (ClO−) with fluorescence quenching in bis-tris buffer. The limit of detection of AFC for ClO− was analyzed to be 58.7 μM. Importantly, AFC could be employed as an efficient and practical fluorescent sensor for ClO− in water sample and zebrafish. Moreover, AFC showed a marked selectivity to ClO− over varied competitive analytes with reactive oxygen species. The detection process of AFC to ClO− was illustrated by UV–visible and fluorescent spectroscopy and electrospray ionization–mass spectrometry (ESI–MS).

A phenylethynyl-terminated imide oligomer (LaRC PETI-5®) with a number average molecular weight of 25OO g / mol has been applied onto the surfaces of PANbased carbon fiber tows and woven carbon fabrics as a sizing material to introduce an interphase between the fiber and matrix in carbon/BMI composites. The adhesion between the fiber and matrix was enhanced by the presence of a properly processed LaRC PETI-5® interphase. The results showed that when LaRC PETI5® was sized and processed at 150°C, the interfacial shear strength (IFSS) of unidirectional IM7/BMI composite measured by using a microindentation technique and the interlaminar shear strength (ILSS) of a carbon/BMI composite measured by short beam shear test were markedly improved by about 35% and 66%, respectively, in comparison with the unsized counterparts. The adhesion enhancement strongly depends not only on the presence or absence of LaRC PETI5® sizing interphase but also on the temperature profile applied to the sizing before composite fabrication. Both of these factors critically influence the physical and chemical state of the sizing material. Scanning electron microscopic observations of the composite fracture surfaces support the improved interracial property of carbon /BMI composites. [ABSTRACT FROM AUTHOR]