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A Sb2Se3 nanorod array was uniformly grown by co-evaporation on a MoSe2 interlayer. MoSe2 interlayer improves the preferential growth and contact quality of Sb2Se3 nanorods.

Early twentieth-century Korean publishing was undergirded by a twofold urgency: the construction of a new inscriptional culture premised on the telos of text production using the Korean writing system and the imperatives of the production of knowledge about Korea’s past against colonial censorship and the colonial episteme. This paper traces early twentieth-century reception of yadam texts from Chosŏn Korea (1392–1910). The paper first examines how the ‘Syosyŏl’ (쇼셜 小說) section of the Korean-language weekly Kyŏnghyang sinmun (Capital and Provinces Weekly, 1906.10.19–1910.12.30) integrated eighteen Chosŏn yadam texts in 1909 and next analyzes the rhetorical framing and orthographic materiality of several collections of tales from precolonial Korea in the 1910s and 1920s. These two reception moments formed a process of transcontextualization that authenticated tales of precolonial Korea as heritage tales, priming Korean co-nationals to romance Korea’s precolonial past as an idyllic haven and a wellspring of national pride.

In this study, we investigated the effect of the stacking order of metal precursors on the formation of volume defects, such as blisters and nanopores, in CZTSSe thin-film solar cells. We fabricated CZTSSe thin films using three types of metal-precursor combinations, namely, Zn/Cu/Sn/Mo, Cu/Zn/Sn/Mo, and Sn/Cu/Zn/Mo, and studied the blister formation. The blister-formation mechanism was based on the delamination model, taking into consideration the compressive stress and adhesion properties. A compressive stress could be induced during the preferential formation of a ZnSSe shell. Under this stress, the adhesion between the ZnSSe film and the Mo substrate could be maintained by the surface tension of a metallic liquid phase with good wettability, or by the functioning of ZnSSe pillars as anchors, depending on the type of metal precursor used. Additionally, the nanopore formation near the back-contact side was found to be induced by the columnar microstructure of the metal precursor with the Cu/Zn/Mo stacking order and its dezincification. Based on the two volume-defect-formation mechanisms proposed herein, further development of volume-defect-formation suppression technology is expected to be made.

This ground-breaking volume on early modern inter-Asian translation examines how translation from plain Chinese was situated at the nexus between, on the one hand, the traditional standard of biliteracy characteristic of literary practices in the Sinographic sphere, and on the other, practices of translational multilingualism (competence in multiple spoken languages to produce a fully localized target text). Translations from plain Chinese are shown to carve out new ecologies of translations that not only enrich our understanding of early modern translation practices across the Sinographic sphere, but also demonstrate that the transregional uses of a non-alphabetic graphic technology call for different models of translation theory.

The standard origin story of Chosŏn fiction glossaries of Shuihuzhuan, Xixiangji, Sanguozhiyanyi, and Xiyouji goes that they emerged primarily because Chosŏn readers lacked linguistic proficiency in vernacular Chinese. Contextualizing fiction glossaries within the Chosŏn reception discourse of the four Chinese works and examining the patterns of explication undergirding fiction glossaries in comparison with those of a glossary of Zhuzi yulei, I instead assert that fiction glossaries were Chosŏn readers’ cultural response to the eloquence of plain Chinese in novelistic writing. Further, I explain that fiction glossaries are a textual space within which the creative, performative, and affective eloquence of Korean is contrasted with the limited articulacy of Literary Sinitic.

Copper indium gallium selenide (Cu(In,Ga)Se2; CIGS) solar cells with small thicknesses active layer have limits to show high efficiency owing to high carrier recombination and low reflection at the electrode/active layer interface. A passivation layer applied to the rear of the CIGS solar cell is regarded as one of the solutions. However, depending on the thickness of the passivation layer, the surface morphology of the thin CIGS absorber layer can be changed, affecting light absorption and photovoltaic properties. In this study, the optical electrical performances of CIGS solar cells with a thin enough layer of the local contact aluminum oxide (Al2O3) (LC-Al2O3) rear passivation were analyzed and demonstrated. The thin passivation layer with tens of nanometers resulted in higher increased efficiency because of improved open circuit voltage and short circuit current density. In addition, from the experiment, the optimal thickness of the thin passivation layer was derived. Too thin a layer causes a degradation of the performance, providing the surface scattering and parasitic resistance. Our results can be used to develop guidelines for designing high-performance CIGS solar cells with optimized passivation layers.

In this paper, we propose that the microstructural control of (hk1) preferentially oriented Sb2Se3 films from flat films to rod arrays can improve their photovoltaic efficiency by maximizing the carrier transport characteristics. We found that, during co-evaporation, there is a narrow substrate temperature window where the Sb2Se3 rod array can be formed with an (hk1) preferred orientation, thus maximizing the carrier transport characteristics. The substrate-temperature-dependent morphology of the Sb2Se3 films can be explained by nucleation and growth theory and the terrace-ledge-kink model. Dramatic changes in the (hk0) and (hk1) texture coefficients occur at 315 °C, and the critical temperature for obtaining the (hk1) preferentially oriented Sb2Se3 film is a substrate temperature of 315 °C. On the basis of the observed variation in the film microstructure and texture coefficient, the optimum Sb2Se3 rod array having an (hk1) preferred orientation is formed in a narrow range of substrate temperatures. As a result, we obtained an optimized Sb2Se3 thin-film rod array that shows effective carrier transportation. Further, the optimum fill factor, short circuit current, open circuit voltage, and efficiency of the Sb2Se3 device were observed in the Sb2Se3 rod array having an (hk1) preferred orientation, and the enhanced carrier transport characteristics are the main reason for the improved device properties. These results show that controlling the microstructure of Sb2Se3 allows improvements in the efficiency of (hk1) preferentially oriented Sb2Se3 films.

We fabricated CZTSSe thin films using optimized SLG-Mo/Zn/Cu/Sn (MZCT) as a stacked structure and described the phenomenon of Zn elemental volatilization using the MZCT stacked structure. We introduced H2S gas to effectively control the S/(S + Se) ratio of the film in the sulfo-selenization process and to suppress Zn volatilization. Unlike during the selenization process, a stable ZnSSe thin film was formed on the precursor surface during the sulfo-selenization process. The formation of the ZnSSe thin film inhibited Zn volatilization, which facilitated control of the thin film stoichiometry and played an important role in crystal growth. In addition, the sulfo-selenization process using H2S forms a grading of the S/(S + Se) ratio in the depth direction in the ZnSSe layer. The ZnSSe layer with this property causes the band gap grading in the CZTSSe absorption layer. Finally, through our optimized annealing process, we realized a world record CZTSSe solar cell with a certified power conversion efficiency of 12.62% and a centimetre-scale (1.1761 cm2) efficiency of 11.28%.

Choice of appropriate biomaterial is a key factor for the success of recombinant human bone morphogenetic protein (rhBMP)-2 therapy. Inspired by osteogenic cell-differentiating and osteoclast-suppressing capabilities of alendronate (ALN), we manufactured a composite type of ALN-loaded collagen sponge (ALN-CS), which controls the early detrimental effect of high-dose rhBMP-2. This study aimed to evaluate ALN-CS as a high-dose rhBMP-2 carrier by investigating its initial biomolecular effect and efficacy on intramembranous ossification at 1, 4, 8, and 24 weeks using a rat calvarial defect model compared with nonloaded CS. The in vitro rhBMP-2 release in the ALN-CS showed a low initial burst and steady release phase during the rest period despite lack of calcium compared with that in CS alone. ALN release showed the same tendency as rhBMP-2 release. In vitro characterization showed that osteoblast differentiation and mineralization of mesenchymal stromal cells were more enhanced with ALN-CS. The ALN-CS-BMP group showed higher expression of bone-forming and -resorbing markers in vivo than the CS-BMP group after the first 7 days, which might be attributable to the relatively large amount of rhBMP-2 remaining. However, osteoclast activation in the ALN-CS-BMP group was significantly reduced compared with the CS-BMP group. Radiological and histological analyses revealed that ALN-CS-BMP promoted early and dense ossification at the initial defect, with 100% greater bone mass, 20% greater bone density, and less fatty marrow tissue than CS-BMP, which continued during the whole healing period. However, CS or ALN-CS alone failed to show complete defect closure even at the 24-week healing interval. Our results demonstrate that ALN-CS has remarkable advantages over CS alone in high-dose BMP-2 delivery, with potent suppression of resorption, early and dense ossification at the target area with less fatty marrow formation, and continuation of bone quality over the long term, which highlights its great clinical potential as a rhBMP carrier for bone regeneration at intramembranous ossification sites.

Mutational profiles of 153 Korean myelodysplastic syndrome (MDS) patients were investigated. Sequencing of 87 genes presented similar mutational profiles in Korean MDS patients compared with previous reports. The most frequently mutated genes were ASXL1 (22.9%), U2AF1 (16.3%), TP53 (13.7%), RUNX1 (10.5%), TET2 (10.5%), DNMT3A (8.5%), and SRSF2 (8.5%). The U2AF1 mutation frequency was higher, with different frequencies in the mutated sites of U2AF1 (S34Y, 6/25; S34F, 11/25; and Q157P 8/25). The U2AF1 S34Y mutation was strongly associated with isolated trisomy 8 (5/6, 83%) and was characterized by a younger age of MDS onset (median, 39 years). The S34F mutation was associated with trisomy 8 (6/11, 55%) and del(20q) (3/11, 27%). Data from 10 literatures (total 3460 patients) of 229 U2AF1-mutated cases revealed a significant association between the S34Y and trisomy 8 in Asians (P=0.0001), but not in Caucasians (P=0.080). We infer that U2AF1 S34 mutations characterize a distinct subgroup of MDS: younger age of onset and differential associations with particular cytogenetic aberrations depending on specific mutations [S34Y to +8; S34F to +8 and del(20q)]. The impact and causal relationship between U2AF1 S34 and trisomy 8 need to be elucidated, which might contribute to design of tailored treatments.

Background: Flowable hemostatic agents may be more advantageous than nonflowable hemostats, as they have capability to cover irregular wound surfaces, fill deep lesions, and easily remove excess materials with irrigation. In this study, we evaluated the hemostatic efficacy of the collagen hemostatic matrix (CHM) compared to FloSeal ® via incisions in the heart and cardiac vessels in a porcine model. Methods: In each of the two female pigs, a total of two incisions were made in seven locations: right atrium (RA), right ventricle (RV), and cardiac vessels, such as the innominate vein (IV), superior vena cava (SVC), pulmonary artery (PA), coronary artery (CA), and aorta. Hemostatic agents were applied directly to the bleeding wounds. In certain location, one incision was treated with the CHM and the other with FloSeal ® , and the time to hemostasis and the degree of bleeding of the two agents were assessed and compared. One week after surgery, the animals were sacrificed, and specimens were collected for histologic evaluation. Results: Bleeding from the vessels with relatively low pressure (the IV, SVC, and RA) was controlled within 1–2 minutes using both a CHM and FloSeal ® . Bleeding from the vessels with high blood pressure (the RV, PA, CA, and aorta) was controlled within 3–10 minutes with the CHM. However, hemostasis in the PA and CA was not achieved with FloSeal ® . Histological analysis revealed that the use of both the CHM and FloSeal ® resulted in foreign body reactions of similar severity. Conclusions: The hemostatic effect and safety of the CHM may be similar to that of FloSeal ® . Further clinical studies must be conducted to validate our results.

For kesterite copper zinc tin sulfide/selenide (CZTSSe) solar cells to enter the market, in addition to efficiency improvements, the technological capability to produce flexible and large-area modules with homogeneous properties is necessary. Here, we report a greater than 10% efficiency for a cell area of approximately 0.5 cm2 and a greater than 8% efficiency for a cell area larger than 2 cm2 of certified flexible CZTSSe solar cells. By designing a thin and multi-layered precursor structure, the formation of defects and defect clusters, particularly tin-related donor defects, is controlled, and the open circuit voltage value is enhanced. Using statistical analysis, we verify that the cell-to-cell and within-cell uniformity characteristics are improved. This study reports the highest efficiency so far for flexible CZTSSe solar cells with small and large areas. These results also present methods for improving the efficiency and enlarging the cell area. Flexibility and homogeneity are preferred properties for the kesterite solar modules to compete with silicon counterparts. Here, Yang et al. achieve these properties by designing a thin and multi-layered precursor structure and at the same time increase the open circuit voltage and device efficiency.

Although Cu2ZnSn(S,Se)4 (CZTSSe) has attracted attention as an alternative to CuInGaSe2 (CIGS) as an absorber material in solar cells, its low efficiency is a serious shortcoming preventing its commercialization. To realize a high-efficiency CZTSSe solar cell, improved grain crystallinity, inhibited secondary-phase formation, controlled defect generation, adequate Na content, and band gap grading are required in the absorber layer. Few studies have focused specifically on band gap grading. In this study, a method of using SeS2, a new potential chalcogenization source material, to control the S and Se contents in a CZTSSe absorber and its effects were investigated. Using an appropriate SeS2/Se weight ratio, band gap grading was realized within the depletion region. By increasing the value of VOC through band gap grading in the depletion region, a record VOC deficit of 0.576 V was achieved. Furthermore, the possibility of enhancing JSC through the formation of a type-inverted n-type phase at the absorber surface in response to an appropriate alignment of the conduction-band minimum energy level and the Fermi energy pinning level is discussed. By introducing the chalcogenization source material SeS2 during the annealing process, CZTSSe solar cells with a maximum efficiency of 12.3% were obtained.

Collagen, one of the most important components of the extracellular matrix (ECM), may play a role in the survival of pancreatic islet cells. In addition, chemical modifications that change the collagen charge profile to a net positive charge by esterification have been shown to increase the adhesion and proliferation of various cell types. The purpose of this study was to characterize and compare the effects of native collagen (NC) and esterified collagen (EC) on β cell function and survival. After isolation by the collagenase digestion technique, rat islets were cultured with NC and EC in 2 dimensional (2D) and 3 dimensional (3D) environments for a long-term duration in vitro. The cells were assessed for islet adhesion, morphology, viability, glucose-induced insulin secretion, and mRNA expression of glucose metabolism-related genes, and visualized by scanning electron microscopy (SEM). Islet cells attached tightly in the NC group, but islet cell viability was similar in both the NC and EC groups. Glucose-stimulated insulin secretion was higher in the EC group than in the NC group in both 2D and 3D culture. Furthermore, the mRNA expression levels of glucokinase in the EC group were higher than those in the NC group and were associated with glucose metabolism and insulin secretion. Finally, SEM observation confirmed that islets had more intact component cells on EC sponges than on NC sponges. These results indicate that modification of collagen may offer opportunities to improve function and viability of islet cells.

The improvement of the efficiency of Cu2ZnSn(S,Se)4 (CZTSSe)-based solar cells requires the formation of high-grain-sized pure CZTSSe throughout the film. We have successfully selenized precursor samples of Cu/SnS/ZnS/Mo/Soda lime glass in an almost sealed selenium furnace. Owing to the presence of confined and high-pressure Se vapor in the furnace, Se easily diffused into the precursor samples, and high-quality Se-rich CZTSSe absorbers were obtained. To understand the effect of the growth mechanism in our precursor and annealing system, this study examines the phase evolution and grain formation. Device parameters are discussed from the perspective of a material microstructure in order to improve performance. At a selenization temperature of 570 °C, a CZTSSe film showed fully developed grains with a size of around 2 μm without noticeable pore development near the Mo back contact. Solar cells with up to 8.03% efficiency were obtained with a layer thickness of about 1.2 μm. Detailed electrical analysis of ...

Objectives: We investigated mutation profiles of CALR , JAK2 , and MPL in 199 Korean patients with myeloproliferative neoplasms (MPNs). Methods: In total, 199 patients with MPN (54 primary myelofibrosis [PMF], 79 essential thrombocythemia [ET], 58 polycythemia vera [PV], and eight MPN-unclassifiable [MPN-U]) and 4 patients with acute panmyelosis with myelofibrosis (APMF) were retrospectively subjected to Sanger sequencing for CALR , JAK2 , and MPL . Results: The overall frequency of CALR mutations was 12.6% (type 1 mutation, 16 patients; type 2 mutation, nine patients): most frequent in MPN-U (37.5%), followed by ET (17.7%) and PMF (14.8%). CALR mutations were not found in PV or APMF. CALR and JAK2 or MPL mutations were mutually exclusive. In PMF, the CALR mutations were associated with lower levels of leukocytes, lower bone marrow cellularity, and higher number of megakaryocytes. Patients with CALR -mutated ET more frequently progressed to the accelerated or blast phases compared with patients with JAK2 mutations. CALR mutations were frequently observed in the JAK2 -negative MPNs, most frequently in MPN-U. Conclusions: The prognostic significance of CALR mutations likely differs among the MPN subtypes.

Raman scattering and atomic force microscopy measurements on Cu 2 ZnSnS 4 thin films prepared by a direct solution method revealed that metal sulfates of various morphologies (dense clusters or separated particles) were partially embedded on the surface of the Cu 2 ZnSnS 4 layer. This residue was removed during the subsequent chemical bath deposition of the CdS buffer layer. However, the removal of the residue led to poor crystallinity and reduced photocurrent near the location of the residue, which suggests that controlling the formation of the sulfates during the fabrication of the absorber layer would be critical for obtaining high efficiency solar cells by the solution method.

Cu2ZnSnS4 (CZTS) solar cells are attracting significant attention as an alternative to CIGS (Culn1-xGa(x)S2) solar cells because of the non-toxic and inexpensive constituent elements of CZTS. Recently, solution-based deposition methods are being developed because they have advantages such as suitability for use in large-area deposition, high-throughput manufacturing, and a very short energy payback time with drastically lower manufacturing costs. In this work, we fabricated solution-based CZTS thin films and investigated them in order to observe the effects of sulfurization temperature on CZTS thin films. We confirmed the grain size, morphology, chemical composition, crystallinity, and electrical properties of CZTS thin films depending on various sulfurization temperatures.

Objectives: Crystal-storing histiocytosis (CSH) is an uncommon finding in plasma cell neoplasms. CSH is thought to be an intralysosomal deposition of secreted paraproteins or immunoglobulins, which usually express κ immunoglobulin light chains that finally aggregate in crystals. Because of its rarity, CSH in bone marrow often makes diagnosis difficult. Methods: A 57-year-old woman had IgA κ monoclonal proteinemia and monoclonal proteinuria. In the bone marrow aspirate, plasma cells were initially counted less than what would be expected, whereas histiocytes with intracellular crystals were increased. Then, we used α–naphthyl acetate esterase (ANAE) staining to distinguish between true histiocytes and plasma cells. Immunostaining for κ, CD138, CD56, and CD68 was performed on a bone marrow biopsy specimen. Results: True histiocytes containing crystalline inclusions were stained strongly for ANAE, while unstained cells with intracytoplasmic crystals represented plasma cells. The biopsy specimen revealed diffuse infiltration of CD138-positive plasma cells. We also confirmed the presence of plasma cells, histiocytes, and their crystallized inclusions with the immunostaining. The patient was finally diagnosed with plasma cell myeloma. Conclusions: The diagnosis was challenging; the bone marrow findings resembled features of other histiocytic disorders. The use of immunohistochemistry enabled the diagnosis of CSH in the presence of plasma cell myeloma.

We studied how to effectively add/remove organic chemicals to/from CZTS precursor thin films to prepare uniform CZTS thin films that show optimal properties. We used multi-functional thiourea, as both a stabiliser and a source of sulphur, to prepare the precursor solutions. This is because it forms complexes with metal chlorides, which stabilise the CZTS precursor solutions and enable CZTS thin films to be spin-coated onto substrates thereby enabling fabrication of CZTS absorbers. However, the excess thiourea, required to stabilise the CZTS precursor solutions, induced the formation of a ZnS secondary phase in the CZTS thin films, which deteriorated the photovoltaic properties of the CZTS solar cells. We therefore pre-annealed the thin films to inhibit ZnS formation. We used the thiourea-stabilized CZTS precursor solutions and simple solution processing techniques to prepare CZTS precursor thin films, and optimized the pre-annealing temperature to fabricate CZTS solar cells that showed 5.29% efficiency.

We have investigated the effects of the addition of tantalum (Ta) and yttrium (Y) ions to InZnO thin film transistors (TFTs) using the sol-gel process. TaInZnO and YInZnO TFTs had significantly lower off current and higher on-to-off current ratio than InZnO TFTs. Ta and Y ions have strong affinity to oxygen and so suppress the formation of free electron carriers in thin films; they play an important role in enhancing the electrical characteristic due to their high oxygen bonding ability. The optimized TaInZnO and YInZnO TFTs showed high on/off ratio and low subthreshold swing.

Sustained release of bone morphogenetic protein (BMP)-2 by heparin-contained biomaterials is advantageous for bone tissue regeneration using low-dose BMP-2. However, its effect with high-dose BMP-2 is still unclear and should be clarified considering the clinical use of a high dose of BMP-2 in spine and oral surgery. This study aimed to evaluate the efficacy of a heparin-conjugated collagen sponge (HCS) with high-dose BMP-2 delivery by investigating in vivo initial osteogenic regulation and bone healing over 12 weeks in comparison with that of an absorbable collagen sponge (ACS). The in vitro BMP-2 release profile in the HCS exhibited a lower burst followed by a sustained release of BMP-2, whereas that of the ACS showed an initial burst phase only. As a result of a lower burst, the HCS-BMP group showed higher expression of bone-forming/resorbing markers and enhanced activation of osteoclasts than the ACS-BMP group within the scaffold of defect after 7 days, which is presumed to be because of retention of relatively higher amounts of BMP-2. However, the surrounding calvariae were less resorbed in the HCS-BMP group, compared with the aggressive resorptive response in the ACS-BMP group. Microcomputed tomography and histology revealed that HCS-BMP guided more effective bone regeneration of central defect over time inducing minor ossification at the defect exterior, whereas ACS-BMP exhibited excessive ossification at the defect exterior. These results showed that HCS-mediated BMP-2 delivery at a high dose has advantages over ACS, including less early resorption of surrounding bone tissue and higher efficacy in compact bone regeneration over a longer period, highlighting a clinical feasibility of this technology.

Background Commercially available hemostatic-adhesive has the risk of disease transmission because it is derived from a plasma component. The purpose of this study is to manufacture a new hemostatic adhesive and evaluate its performances. Methods Two atelocollagen-based hemostatic adhesives were produced and named as Bleestop A (2% esterified atelocollagen in 75% ethanol + 1% CaCl2 + 0.71% DOPA + 0.1% tranexamic acid in DW) and Bleestop B (2% esterified atelocollagen in DW + 1% CaCl2 + 0.71% DOPA + 0.1% aminocaproic acid in DW). These are compared with the negative control group (no adhesives used group) and the positive control group (Tissucol Duo Quick group). The adult male Sprague-Dawley rat model was adopted and the hemostatic-adhesion activities of each group were assessed by the adhesion strength test and the morphologic features of adhesion. The liver tissues were used. Histologic assessment of adhesion was accessed using light microscopy. Results Bleeding was controlled immediately after application of Bleestop A and partial adhesion was observed after 30 s. More than 95% area of the resected surface attached after 1 min. In Bleestop B, partial adhesion was observed after 30 s. More than 95% area of the resected surface was attached after 45 s. Histologic evaluation showed that Bleestop A and B mediated organized adhesion rapidly between both resected tissue surfaces. The adhesion strength of Bleestop A and B was better than the negative control group and showed same adhesion strength as the positive control group after 3 min. Conclusion Bleestop A and B showed significant hemostasis and adhesion capability within 1 min. They are comparable to the positive control group.

Objectives The purpose of this study was to evaluate the effect of Tisseel on the early healing of bone defects in the skulls of rats. Study design Forty-eight rats were randomly assigned to 4 groups, and each group was further divided into 3 subgroups which were examined at 4 and 8 weeks after the defects were filled. The 4 different groups were animals containing: no graft (group 1); particulate dentin and plaster of Paris mixture graft (group 2); Tisseel and particulate dentin and plaster of Paris mixture graft (group 3); and Tisseel graft (group 4). After killing the animals at 4 and 8 weeks after surgery, all implant blocks were prepared for histologic sections and histomorphometric analysis. Results The overall new bone formation was significantly different between the 4-week samples and the 8-week samples. Significant differences between groups 1 and 2, groups 1 and 3, groups 1 and 4, groups 2 and 4, and groups 3 and 4 were observed at 4 weeks after surgery. At 8 weeks after surgery, significant differences between groups 1 and 2, groups 1 and 3, groups 1 and 4, and groups 2 and 4 were observed. As expected, effective bone formation was observed when the defects were filled with either particulate dentin, Tisseel, or particulate dentin–Tisseel combination. It was also observed from this study that particulate dentin is especially effective, followed by the particulate dentin–Tisseel combination and Tisseel. Conclusion It was concluded that the use of Tisseel may be an alternative therapy for regenerating bone in defects when used in combination with particulate dentin.

Background Collagen exhibits ideal multifactorial action for preventing tissue adhesions. This study examined the efficacy of ionized collagen in preventing tissue adhesion after surgical procedures. Materials and method Ionized collagen was prepared using the esterification technique of natural collagen. Three forms of collagen materials (membrane, film, and gel) were compared with three commercialized materials (oxidized regenerated cellulose membrane [OC membrane], hyaluronic acid and carboxymethylcellulose film, and gel [HC film and HC gel]) in a rat cecum abrasion model. Antiadhesive activity and histologic findings were assessed. Result The incidence of adhesion was reduced significantly in all test groups compared to the sham-operated control group (100% in control, 14.3% in collagen membrane, 63.6% in collagen film, 25.0% in collagen gel, 55.6% in OC membrane, 75% in HC film, and 83.3% in HC gel). All collagen materials of the three forms exhibited a significant reduction in adhesion grade compared with the sham operation, whereas no significant difference was found among these three different forms. The collagen membrane showed significantly less adhesion grade, less inflammation and more regenerative features compared to widely used conventional materials. Conclusions This preclinical investigation indicated that ionized collagen materials readily formed clinically suitable shapes for easy handling without the need for any complex processing and effectively reduced postoperative tissue adhesion profiles compared to conventional antiadhesive agents.

To investigate the effect of injectable PLGA sphere's diameter on adipose tissue engineering, rabbit mesenchymal stem cells were attached to various diameters of injectable PLGA spheres (75; 75-100; 100-150; 150-200; and 200-250 microm). These five groups were cultured in adipogenic media for 2 weeks in vitro and injected into necks of nude mice. Prior to in vivo study, cell proliferation and adipogenic differentiation were determined by hexosaminidase assay and Oil red O staining after 2 weeks. Group C (100-150 microm) showed the highest adipogenic differentiation and the proliferation capacity of Group B (75-100 microm) was significantly higher than that of any other group. We harvested newly formed tissues from necks of nude mice after 1 and 4 weeks. Although PLGA spheres have not been degraded and there was no significant histological difference among various sizes of spheres after 1 week, well-organized fat pads (PLGA spheres were completely degraded) could be observed, and the histology of the 100-150 microm groups resembled that of native tissue after 4 weeks. Based on these experiments, we could conclude that the optimal size of PLGA spheres for adipogenesis was 100-150 microm.

Postoperative adhesions remain a significant complication of abdominal surgery although the wide variety of physical barriers has been developed to reduce the incidence of adhesion. In this study, the bilayered composite membrane formed by the association of a methoxy poly (ethylene glycol)-poly (L-lactide-co-glycolide) (mPEG-PLGA) film and a crosslinked collagen-hyaluronic acid (Col-HA) membrane with fibronectin (FN) coating was prepared for promoting wound healing and providing tissue adhesion resistance simultaneously. In vitro adhesion test revealed that fibroblasts attached better on Col-HA membrane compared to those on mPEG-PLGA film, PLGA film or Interceed (oxidized cellulose) while mPEG-PLGA film had the lowest cell adhesive property. In confocal microscopic observation, the actin filaments were significantly further polymerized when 50 or 100 microg/cm(3) fibronectin was incorporated on the COL-HA membranes. After 7-day culture, fibroblasts penetrated throughout the Col-HA-FN network and the cell density increased whereas very few cells were found attached on the surface of the mPEG-PLGA film. In vivo evaluation test showed that the composite membrane could remain during the critical period of peritoneal healing and did not provoke any inflammation or adverse tissue reaction.

Cu2ZnSnS4 (CZTS) solar cells are attracting significant attention as an alternative to CIGS (Culn1-xGa(x)S2) solar cells because of the non-toxic and inexpensive constituent elements of CZTS. Recently, solution-based deposition methods are being developed because they have advantages such as suitability for use in large-area deposition, high-throughput manufacturing, and a very short energy payback time with drastically lower manufacturing costs. In this work, we fabricated solution-based CZTS thin films and investigated them in order to observe the effects of sulfurization temperature on CZTS thin films. We confirmed the grain size, morphology, chemical composition, crystallinity, and electrical properties of CZTS thin films depending on various sulfurization temperatures.