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Sample records for absorbable collagen sponge

  1. Bone formation around rhBMP-2-coated implants in rabbit sinuses with or without absorbable collagen sponge grafting

    PubMed Central

    2015-01-01

    Purpose The purpose of this study was to evaluate bone formation around recombinant human bone morphogenetic protein (rhBMP-2)-coated implants placed with or without absorbable collagen sponge (ACS) in rabbit maxillary sinuses. Methods The Schneiderian membrane was elevated and an implant was placed in 24 sinuses in 12 rabbits. The space created beneath the elevated membrane was filled with either blood (n=6) or ACS (n=6). In the rabbits in which this space was filled with blood, rhBMP-2-coated and non-coated implants were alternately placed on different sides. The resulting groups were referred to as the BC and BN groups, respectively. The AC and AN groups were produced in ACS-grafted rabbits in the same manner. Radiographic and histomorphometric analyses were performed after eight weeks of healing. Results In micro-computed tomography analysis, the total augmented volume and new bone volume were significantly greater in the ACS-grafted sinuses than in the blood-filled sinuses (P<0.05). The histometric analysis showed that the areas of new bone and bone-to-implant contact were significantly larger in the AC group than in the AN group (P<0.05). In contrast, none of the parameters differed significantly between the BC and BN groups. Conclusions The results of this pilot study indicate that the insertion of ACS after elevating the Schneiderian membrane, simultaneously with implant placement, can significantly increase the volume of the augmentation. However, in the present study, the rhBMP-2 coating exhibited limited effectiveness in enhancing the quantity and quality of regenerated bone. PMID:26734494

  2. Synergy between IL-6 and soluble IL-6 receptor enhances bone morphogenetic protein-2/absorbable collagen sponge-induced bone regeneration via regulation of BMPRIA distribution and degradation.

    PubMed

    Huang, Ru-Lin; Chen, Gang; Wang, Wenjin; Herller, Tanja; Xie, Yun; Gu, Bin; Li, Qingfeng

    2015-10-01

    Bone morphogenetic protein-2/absorbable collagen sponge (BMP-2/ACS) implants have been approved for clinical use to induce bone regeneration. We previously showed that exaggerated inflammation characterized by elevated level of inflammatory cytokines including TNF-α, IL-1β, and IL-6 has been shown to inhibit BMP-2/ACS-induced bone regeneration. Furthermore, unlike the negative effects of TNF-α and IL-1β, IL-6 seemed not to affect BMP-2-induced osteoblastic differentiation of bone marrow mesenchymal stem cells (BMSCs). We hypothesized that there may be a regulatory loop between IL-6 and BMP-2 singling to affect BMP-2/ACS-induced bone regeneration. Here, we established a BMP-2/ACS-induced ectopic bone formation model in rats and fund that IL-6 injection significantly increased BMP-2/ACS-induced bone mass. Consistent with this animal model, an in vitro study demonstrated that synergy between IL-6 and soluble IL-6 receptor (IL-6/sIL-6R) promotes BMP-2-induced osteoblastic differentiation of human BMSCs through amplification of BMP/Smad signaling. Strikingly, IL-6 injection did not activate osteoclast-mediated bone resorption in the ectopic bone formation model, and IL-6/sIL-6R treatment did not affect receptor activator of NF-κB ligand (RANKL)-induced osteoclastic differentiation of human peripheral blood mononuclear cells (PBMCs) in vitro. Furthermore, IL-6/sIL-6R treatment did not affect expression of BMP receptors, but enhanced the cell surface translocation of BMP receptor IA (BMPRIA) and inhibited the degradation of BMPRIA. Collectively, these findings indicate that synergy between IL-6 and sIL-6R promotes the cell surface translocation of BMPRIA and maintains the stability of BMPRIA expression, leading to enhanced BMP-2/ACS-induced bone regeneration. PMID:26232880

  3. A Comparison of Conventional Collagen Sponge and Collagen-Gelatin Sponge in Wound Healing

    PubMed Central

    Jinno, Chizuru; Morimoto, Naoki; Ito, Ran; Sakamoto, Michiharu; Ogino, Shuichi; Taira, Tsuguyoshi; Suzuki, Shigehiko

    2016-01-01

    The objective of this study was to compare the effectiveness of the collagen-gelatin sponge (CGS) with that of the collagen sponge (CS) in dermis-like tissue regeneration. CGS, which achieves the sustained release of basic fibroblast growth factor (bFGF), is a promising material in wound healing. In the present study, we evaluated and compared CGSs and conventional CSs. We prepared 8 mm full-thickness skin defects on the backs of rats. Either CGSs or CSs were impregnated with normal saline solution (NSS) or 7 μg/cm2 of bFGF solution and implanted into the defects. At 1 and 2 weeks after implantation, tissue specimens were obtained from the rats of each group (n = 3, total n = 24). The wound area, neoepithelial length, dermis-like tissue area, and the number and area of capillaries were evaluated at 1 and 2 weeks after implantation. There were no significant differences in the CGS without bFGF and CS groups. Significant improvements were observed in the neoepithelial length, the dermis-like tissue area, and the number of newly formed capillaries in the group of rats that received CGSs impregnated with bFGF. The effects on epithelialization, granulation, and vascularization of wound healing demonstrated that, as a scaffold, CGSs are equal or superior to conventional CSs. PMID:27218103

  4. Effect of collagen sponge and fibrin glue on bone repair

    PubMed Central

    SANTOS, Thiago de Santana; ABUNA, Rodrigo Paolo Flores; de ALMEIDA, Adriana Luisa Gonçalves; BELOTI, Marcio Mateus; ROSA, Adalberto Luiz

    2015-01-01

    ABSTRACT The ability of hemostatic agents to promote bone repair has been investigated using in vitro and in vivo models but, up to now, the results are inconclusive. Objective In this context, the aim of this study was to compare the potential of bone repair of collagen sponge with fibrin glue in a rat calvarial defect model. Material and Methods Defects of 5 mm in diameter were created in rat calvariae and treated with either collagen sponge or fibrin glue; untreated defects were used as control. At 4 and 8 weeks, histological analysis and micro-CT-based histomorphometry were carried out and data were compared by two-way ANOVA followed by Student-Newman-Keuls test when appropriated (p≤0.05). Results Three-dimensional reconstructions showed increased bone formation in defects treated with either collagen sponge or fibrin glue compared with untreated defects, which was confirmed by the histological analysis. Morphometric parameters indicated the progression of bone formation from 4 to 8 weeks. Additionally, fibrin glue displayed slightly higher bone formation rate when compared with collagen sponge. Conclusion Our results have shown the benefits of using collagen sponge and fibrin glue to promote new bone formation in rat calvarial bone defects, the latter being discreetly more advantageous. PMID:26814464

  5. Three-Dimensional Porous Sponges from Collagen Biowastes.

    PubMed

    Ashokkumar, Meiyazhagan; Cristian Chipara, Alin; Tharangattu Narayanan, Narayanan; Anumary, Ayyappan; Sruthi, Radhakrishnan; Thanikaivelan, Palanisamy; Vajtai, Robert; Mani, Sendurai A; Ajayan, Pulickel M

    2016-06-15

    Three-dimensional, functional, and porous scaffolds can find applications in a variety of fields. Here we report the synthesis of hierarchical and interconnected porous sponges using a simple freeze-drying technique, employing collagen extracted from animal skin wastes and superparamagnetic iron oxide nanoparticles. The ultralightweight, high-surface-area sponges exhibit excellent mechanical stability and enhanced absorption of organic contaminants such as oils and dye molecules. Additionally, these biocomposite sponges display significant cellular biocompatibility, which opens new prospects in biomedical uses. The approach highlights innovative ways of transforming biowastes into advanced hybrid materials using simple and scalable synthesis techniques. PMID:27219483

  6. Effect of starch on the mechanical and in vitro properties of collagen-hydroxyapatite sponges for applications in dentistry.

    PubMed

    Castro-Ceseña, Ana B; Camacho-Villegas, Tanya A; Lugo-Fabres, Pavel H; Novitskaya, Ekaterina E; McKittrick, Joanna; Licea-Navarro, Alexei

    2016-09-01

    This study sought to improve the mechanical and blood-absorbing properties of collagen sponges, while keeping them compressible, by incorporating blended hydroxyapatite (HA)-starch. Results were compared with CollaPlug(®) (pure collagen). The elastic modulus increased from 1.5±0.2kPa for CollaPlug(®) to 49±8kPa for sponges with composition 1:4:10 (collagen:HA:starch, by weight). The modified microstructure and surface area provided by the starch granules on the sponges improved cell viability. Sponges with composition 1:4:10 maintained their blood-clotting capability with almost no change from 5 to 15min after contact with blood, while CollaPlug(®) diminished to about half its capacity to absorb blood and form clots. Incorporation of HA-starch into the sponges with composition of 1:4:10, increased the elastic modulus of the collagen-HA sponges, making them more structurally robust. The viability of cells and the blood-clotting capability increased with starch incorporation. PMID:27185118

  7. Using absorbable chitosan hemostatic sponges as a promising surgical dressing.

    PubMed

    Huang, Xiaofei; Sun, Yongfu; Nie, Jingyi; Lu, Wentao; Yang, Ling; Zhang, Zhiliang; Yin, Hongping; Wang, Zhengke; Hu, Qiaoling

    2015-04-01

    As absorbable hemostatic dressings, chitosan with a deacetylation degree of 40% (CS-40) and 73% (CS-73) have been fabricated into sponges via a modified method. The hemostatic, biocompatible and biodegradable properties were evaluated through in vivo assays. In a hepatic hemorrhage model, the chitosan sponges, with excellent blood compatibility, achieved less blood loss than the gelation sponge (GS). In addition, CS-40 showed better hemostatic capability and biodegradability than CS-73. After implantation, a histological analysis indicated that CS-40 exhibited the best biodegradability, tissue regeneration and least tissue adhesion. By contrasting CS-40 and CS-73, the deacetylation degree is confirmed to be a key factor for the hemostatic effect, biodegradability, biocompatibility and tissue regeneration. Our overall results demonstrated the potential application of CS-40 for use in absorbable hemostatic dressings. PMID:25661881

  8. [Healing of a deep skin wound using a collagen sponge as dressing in the animal experiment].

    PubMed

    Sedlarik, K M; Schoots, C; Oosterbaan, J A; Klopper, J P

    1992-10-01

    The high number of available wound dressing materials as well as the scientific reports about the topic indicates that the problem of an ideal wound dressing is not jet solved. In the last thirty years lot of scientific reports about collagen as wound covering has been published. The positive effect of collagen by his application on a wound ist well known. We investigated the effect of a collagen sponge on healing of full thickness skin wound in guinea pig. The animals were divided in two control groups and two experimental groups. In the control group there were air exposed wounds and another wounds covered with paraffin gauze. In the experimental groups were such wounds covered with natural reconstituted collagen sponge as well as wounds covered with chemically prepared collagen sponge with hexamethyldiisocyanat. The results were compared. The air exposed wounds healed in 50 days, the wounds covered with paraffin gauze healed in 48 days. By covering the wounds with collagen sponge the healing was shortened in 24 or 27 days respectively. Not only the healing time was shortened but also the quality of the wound repair by dressing the wounds with collagen sponge was enhanced. PMID:1361713

  9. Confocal laser-scanning microscopy for determining the structure of and keratinocyte infiltration through collagen sponges.

    PubMed

    Hanthamrongwit, M; Wilkinson, R; Osborne, C; Reid, W H; Grant, M H

    1996-03-01

    The development of artificial skin substitutes based on cultured cells and biomaterials such as collagen requires an understanding of cellular interactions with the substrate. In this study, human keratinocytes were cultured on the surface of collagen sponges, and confocal laser-scanning microscopy (CLSM) was used to assess both the microstructure of the sponge, and the cell morphology and distribution throughout the sponge. It was found that the pore size increased with increasing depth into the sponge. Both pore size and fiber thickness increased during incubation for up to 10 days at 37 degrees C in culture medium in the absence of cells. This latter effect was not observed when the sponges were incubated in distilled water. Keratinocytes penetrated into the sponge even after only 3 days in culture. By 10 days in culture, the cells had penetrated to the maximum depth that could be examined (120 microns from the sponge surface). In the presence of cells, the inner structure of the collagen sponge had altered after 10 days in culture, with the collagen fibers becoming thicker, and pore geometry less regular. The mechanism responsible for this is unknown at present. Although the presence of the keratinocytes increases distortion of the sponge structure, factors from the medium itself also contribute to this effect. CLSM is a powerful tool for assessing cellular interactions with bioimplants, providing both qualitative and quantitative information. It offers many advantages over scanning electron microscopy (SEM) and histological techniques. CLSM minimizes the time-consuming, extensive preparation of samples required with the latter two methods, and allows noninvasive serial optical sectioning of intact samples. PMID:8698696

  10. Characterization of a fibrillar collagen gene in sponges reveals the early evolutionary appearance of two collagen gene families.

    PubMed Central

    Exposito, J Y; Garrone, R

    1990-01-01

    We have characterized cDNA and genomic clones coding for a sponge collagen. The partial cDNA has an open reading frame encoding 547 amino acid residues. The conceptual translation product contains a probably incomplete triple-helical domain (307 amino acids) with one Gly-Xaa-Yaa-Zaa imperfection in the otherwise perfect Gly-Xaa-Yaa repeats and a carboxyl propeptide (240 amino acids) that includes 7 cysteine residues. Amino acid sequence comparisons indicate that this sponge collagen is homologous to vertebrate and sea urchin fibrillar collagens. Partial characterization of the corresponding gene reveals an intron-exon organization clearly related to the fibrillar collagen gene family. The exons coding for the triple-helical domain are 54 base pairs (bp) or multiples thereof, except for a 57-bp exon containing the Gly-Xaa-Yaa-Zaa coding sequence and for two unusual exons of 126 and 18 bp, respectively. This latter 18-bp exon marks the end of the triple-helical domain, contrary to the other known fibrillar collagen genes that contain exons coding for the junction between the triple-helical domain and the carboxyl propeptide. Compared to other fibrillar collagen genes, the introns are remarkably small. Hybridization to blotted RNAs established that the gene transcript is 4.9 kilobases. Together with previous results that showed the existence of a nonfibrillar collagen in the same species, these data demonstrate that at least two collagen gene families are represented in the most primitive metazoa. PMID:2395869

  11. Cell response to single-walled carbon nanotubes in hybrid porous collagen sponges.

    PubMed

    Mao, Hongli; Kawazoe, Naoki; Chen, Guoping

    2015-02-01

    Three-dimensional (3D) porous collagen sponges incorporated with single-walled carbon nanotubes (SWCNTs) were prepared and used for 3D culture of bovine articular chondrocytes (BACs). The pore structures of the sponges were controlled by using ice particulates as a porogen material. The responses of cells to SWCNTs were investigated in this 3D cell culture system by evaluation of cell functions and cellular uptake of SWCNTs. The results showed that cells adhered and spatially distributed in the porous sponges. The incorporation of SWCNTs in the porous sponges promoted cell proliferation and production of sulfated glycosaminoglycans (sGAG). Confocal Raman imaging revealed that SWCNTs could be internalized by cells. The hybrid porous sponges not only provided nanostructured pore surfaces to facilitate cell proliferation and extracellular matrix (ECM) secretion but also supplied nanomaterials for cellular uptake which may be useful for biomedical applications. PMID:25543985

  12. Development of a HPLC Method for the Quantitative Determination of Capsaicin in Collagen Sponge

    PubMed Central

    Guo, Chun-Lian; Chen, Hong-Ying; Cui, Bi-Ling; Chen, Yu-Huan; Zhou, Yan-Fang; Peng, Xin-Sheng; Wang, Qin

    2015-01-01

    Controlling the concentration of drugs in pharmaceutical products is essential to patient's safety. In this study, a simple and sensitive HPLC method is developed to quantitatively analyze capsaicin in collagen sponge. The capsaicin from sponge was extracted for 30 min with ultrasonic wave extraction technique and methanol was used as solvent. The chromatographic method was performed by using isocratic system composed of acetonitrile-water (70 : 30) with a flow rate of 1 mL/min and the detection wavelength was at 280 nm. Capsaicin can be successfully separated with good linearity (the regression equation is A = 9.7182C + 0.8547; R2 = 1.0) and perfect recovery (99.72%). The mean capsaicin concentration in collagen sponge was 49.32 mg/g (RSD = 1.30%; n = 3). In conclusion, the ultrasonic wave extraction method is simple and the extracting efficiency is high. The HPLC assay has excellent sensitivity and specificity and is a convenient method for capsaicin detection in collagen sponge. This paper firstly discusses the quantitative analysis of capsaicin in collagen sponge. PMID:26612986

  13. Biochemical and biophysical characterization of collagens of marine sponge, Ircinia fusca (Porifera: Demospongiae: Irciniidae).

    PubMed

    Pallela, Ramjee; Bojja, Sreedhar; Janapala, Venkateswara Rao

    2011-07-01

    Collagens were isolated and partially characterized from the marine demosponge, Ircinia fusca from Gulf of Mannar (GoM), India, with an aim to develop potentially applicable collagens from unused and under-used resources. The yield of insoluble, salt soluble and acid soluble forms of collagens was 31.71 ± 1.59, 20.69 ± 1.03, and 17.38 ± 0.87 mg/g dry weight, respectively. Trichrome staining, Scanning & Transmission Electron microscopic (SEM & TEM) studies confirmed the presence of collagen in the isolated, terminally globular irciniid filaments. The partially purified (gel filtration chromatography), non-fibrillar collagens appeared as basement type collagenous sheets under light microscopy whereas the purified fibrillar collagens appeared as fibrils with a repeated band periodicity of 67 nm under Atomic Force Microscope (AFM). The non-fibrillar and fibrillar collagens were seen to have affinity for anti-collagen type IV and type I antibodies raised against human collagens, respectively. The macromolecules, i.e., total protein, carbohydrate and lipid contents within the tissues were also quantified. The present information on the three characteristic irciniid collagens (filamentous, fibrillar and non-fibrillar) could assist the future attempts to unravel the therapeutically important, safer collagens from marine sponges for their use in pharmaceutical and cosmeceutical industries. PMID:21501629

  14. Phenotypic analysis of bovine chondrocytes cultured in 3D collagen sponges: effect of serum substitutes.

    PubMed

    Yates, Karen E; Allemann, Florin; Glowacki, Julie

    2005-01-01

    Repair of damaged cartilage usually requires replacement tissue or substitute material. Tissue engineering is a promising means to produce replacement cartilage from autologous or allogeneic cell sources. Scaffolds provide a three-dimensional (3D) structure that is essential for chondrocyte function and synthesis of cartilage-specific matrix proteins (collagen type II, aggrecan) and sulfated proteoglycans. In this study, we assessed porous, 3D collagen sponges for in vitro engineering of cartilage in both standard and serum-free culture conditions. Bovine articular chondrocytes (bACs) cultured in 3D sponges accumulated and maintained cartilage matrix over 4 weeks, as assessed by quantitative measures of matrix content, synthesis, and gene expression. Chondrogenesis by bACs cultured with Nutridoma as a serum replacement was equivalent or better than control cultures in serum. In contrast, chondrogenesis in insulin-transferrin-selenium (ITS(+3)) serum replacement cultures was poor, apparently due to decreased cell survival. These data indicate that porous 3D collagen sponges maintain chondrocyte viability, shape, and synthetic activity by providing an environment favorable for high-density chondrogenesis. With quantitative assays for cartilage-specific gene expression and biochemical measures of chondrogenesis in these studies, we conclude that the collagen sponges have potential as a scaffold for cartilage tissue engineering. PMID:15735900

  15. Inflammatory response study of gellan gum impregnated duck's feet derived collagen sponges.

    PubMed

    Song, Jeong Eun; Lee, Seon Eui; Cha, Se Rom; Jang, Na Keum; Tripathy, Nirmalya; Reis, Rui L; Khang, Gilson

    2016-10-01

    Tissue engineered biomaterials have biodegradable and biocompatible properties. In this study, we have fabricated sponges using duck's feet derived collagen (DC) and gellan gum (GG), and further studied its inflammatory responses. The as-prepared duck's feet DC/GG sponges showed the possibility of application as a tissue engineering material through in vitro and in vivo experiments. The physical and chemical properties of sponges were characterized by compression strength, porosity, and scanning electron microscopy, etc. In vitro cell viability were investigated using 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide (MTT) assay. An inflammatory response was studied after seeding RAW264.7 cells on as-fabricated sponges using reverse transcriptase-polymerase chain reaction. In vivo studies were carried out by implanting in subcutaneous nude mouse followed by extraction, histological staining. Collectively, superior results were showed by DC/GG sponges than GG sponge in terms of physical property and cell proliferation and thus can be considered as a potential candidate for future tissue engineering applications. PMID:27416732

  16. Suspected Intraoperative Anaphylaxis to Gelatin Absorbable Hemostatic Sponge

    PubMed Central

    Ji, Joonyoung; Barrett, Edward J.

    2015-01-01

    Anaphylaxis under anesthesia is a life-threatening medical emergency that requires rapid identification and treatment. Allergies to agents with which the general population are likely to come into contact are usually identified, but patients are exposed to uncommon agents during anesthesia and surgery. Here, we describe a case of anaphylaxis under anesthesia implicating Gelfoam sponges. PMID:25849471

  17. Demineralized bone promotes chondrocyte or osteoblast differentiation of human marrow stromal cells cultured in collagen sponges.

    PubMed

    Zhou, Shuanhu; Yates, Karen E; Eid, Karim; Glowacki, Julie

    2005-01-01

    Demineralized bone implants have been used for many types of craniomaxillofacial, orthopedic, periodontal, and hand reconstruction procedures. In previous studies, we showed that demineralized bone powder (DBP) induces chondrogenesis of human dermal fibroblasts in a DBP/collagen sponge system that optimized interactions between particles of DBP and target cells in cell culture. In this study, we test the hypothesis that DBP promotes chondrogenesis or osteogenesis of human marrow stromal cells (hMSCs) in 3-D collagen sponge culture, depending upon the culture conditions. We first confirmed that hMSCs have chondrogenic potential when treated with TGF-beta, either in 2-D monolayer cultures or in 3-D porous collagen sponges. Second, we found that DBP markedly enhanced chondrogenesis in hMSCs in 3-D sponges, as assessed by metachromasia and expression of chondrocyte-specific genes AGGRECAN, COL II, and COL X. Human dermal fibroblasts (hDFs) were used to define mechanisms of chondroinduction because unlike hMSCs they have no inherent chondrogenic potential. In situ hybridization revealed that hDFs vicinal to DBPs express chondrocyte-specific genes AGGRECAN or COL II. Macroarray analysis showed that DBP activates TGF-beta/BMP signaling pathway genes in hDFs. Finally, DBP induced hMSCs to express the osteoblast phenotype when cultured with osteogenic supplements. These studies show how culture conditions can influence the differentiation pathway that human marrow stromal cells follow when stimulated by DBP. These results support the potential to engineer cartilage or bone in vitro by using human bone marrow stromal cells and DBP/collagen scaffolds. PMID:15735899

  18. Effect of gentamicin-absorbed collagen in wound healing in pilonidal sinus surgery: a prospective randomized study.

    PubMed

    Yetim, I; Ozkan, O V; Dervişoglu, A; Erzurumlu, K; Canbolant, E

    2010-01-01

    Pilonidal sinus is a common disease that causes the loss of many working hours, but treatment is variable and problematic. The effect of gentamicin-absorbed collagen on healing, infection and recurrence, and length of hospital stay were examined after pilonidal sinus surgery. Patients undergoing surgical treatment for pilonidal sinus were randomly assigned into two groups each of 40 patients. Both groups were treated with excision and primary closure under local anaesthesia. Group 1 (control) received oral antibiotics for 7 days post-operatively. In group 2, prior to wound closure, gentamicin-absorbed collagen sponges were placed on the sacral fascia and these patients did not receive oral post-operative antibiotic therapy. Patients in group 2 had a significantly shorter mean wound healing time, significantly lower infection and recurrence rates, and a significantly shorter hospital stay than those in group 1. It is concluded that implantation of a gentamicin-containing collagen sponge on the wound area in pilonidal sinus decreased the rates of infection and recurrence, and shortened the hospital stay. PMID:20819439

  19. Mineralization of the metre-long biosilica structures of glass sponges is templated on hydroxylated collagen.

    PubMed

    Ehrlich, Hermann; Deutzmann, Rainer; Brunner, Eike; Cappellini, Enrico; Koon, Hannah; Solazzo, Caroline; Yang, Yue; Ashford, David; Thomas-Oates, Jane; Lubeck, Markus; Baessmann, Carsten; Langrock, Tobias; Hoffmann, Ralf; Wörheide, Gert; Reitner, Joachim; Simon, Paul; Tsurkan, Mikhail; Ereskovsky, Aleksander V; Kurek, Denis; Bazhenov, Vasily V; Hunoldt, Sebastian; Mertig, Michael; Vyalikh, Denis V; Molodtsov, Serguei L; Kummer, Kurt; Worch, Hartmut; Smetacek, Victor; Collins, Matthew J

    2010-12-01

    The minerals involved in the formation of metazoan skeletons principally comprise glassy silica, calcium phosphate or carbonate. Because of their ancient heritage, glass sponges (Hexactinellida) may shed light on fundamental questions such as molecular evolution, the unique chemistry and formation of the first skeletal silica-based structures, and the origin of multicellular animals. We have studied anchoring spicules from the metre-long stalk of the glass rope sponge (Hyalonema sieboldi; Porifera, Class Hexactinellida), which are remarkable for their size, durability, flexibility and optical properties. Using slow-alkali etching of biosilica, we isolated the organic fraction, which was revealed to be dominated by a hydroxylated fibrillar collagen that contains an unusual [Gly-3Hyp-4Hyp] motif. We speculate that this motif is predisposed for silica precipitation, and provides a novel template for biosilicification in nature. PMID:21107374

  20. Gentamicin-impregnated collagen sponge for preventing sternal wound infection after cardiac surgery

    PubMed Central

    Targońska, Sylwia; Stążka, Janusz; Kozioł-Montewka, Maria

    2014-01-01

    The frequency of sternal wound infection (SWI) after cardiac surgery ranges from 0.5% to 8% and is associated with significant morbidity, mortality, and treatment cost. Perioperative antibiotic prophylaxis is not sufficient to fully prevent the contamination of the surgical access site. One of the most effective methods for the prevention of wound infection seems to be the use of gentamicin-impregnated collagen sponge, which is successfully used in abdominal and orthopedic surgery. Surgically implantable topical antibiotics can reduce wound infection in cardiac patients as well, but the efficacy of SWI prevention in cardiac surgery still raises many questions. PMID:26336388

  1. Stimulation of protein (collagen) synthesis in sponge cells by a cardiac myotrophin-related molecule from Suberites domuncula.

    PubMed

    Schröder, H C; Krasko, A; Batel, R; Skorokhod, A; Pahler, S; Kruse, M; Müller, I M; Müller, W E

    2000-10-01

    The body wall of sponges (Porifera), the lowest metazoan phylum, is formed by two epithelial cell layers of exopinacocytes and endopinacocytes, both of which are associated with collagen fibrils. Here we show that a myotrophin-like polypeptide from the sponge Suberites domuncula causes the expression of collagen in cells from the same sponge in vitro. The cDNA of the sponge myotrophin was isolated; the potential open reading frame of 360 nt encodes a 120 aa long protein (Mr of 12,837). The sequence SUBDOMYOL shares high similarity with the known metazoan myotrophin sequences. The expression of SUBDOMYOL is low in single cells but high after formation of primmorph aggregates as well as in intact animals. Recombinant myotrophin was found to stimulate protein synthesis by fivefold, as analyzed by incorporation studies using [3H] lysine. In addition, it is shown that after incubation of single cells with myotrophin, the primmorphs show an unusual elongated, oval-shaped appearance. It is demonstrated that in the presence of recombinant myotrophin, the cells up-regulate the expression of the collagen gene. The cDNA for S. domuncula collagen was isolated; the deduced aa sequence shows that the collagenous internal domain is rather short, with only 24 G-x-y collagen triplets. We conclude that the sponge myotrophin causes in homologous cells the same/similar effect as the cardiac myotrophin in mammalian cells, where it is involved in initiation of cardial ventricular hypertrophy. We assume that an understanding of sponge molecular cell biology will also contribute to a further elucidation of human diseases, here of the cardiovascular system. PMID:11023986

  2. Interstitial Perfusion Culture with Specific Soluble Factors Inhibits Type I Collagen Production from Human Osteoarthritic Chondrocytes in Clinical-Grade Collagen Sponges.

    PubMed

    Mayer, Nathalie; Lopa, Silvia; Talò, Giuseppe; Lovati, Arianna B; Pasdeloup, Marielle; Riboldi, Stefania A; Moretti, Matteo; Mallein-Gerin, Frédéric

    2016-01-01

    Articular cartilage has poor healing ability and cartilage injuries often evolve to osteoarthritis. Cell-based strategies aiming to engineer cartilaginous tissue through the combination of biocompatible scaffolds and articular chondrocytes represent an alternative to standard surgical techniques. In this context, perfusion bioreactors have been introduced to enhance cellular access to oxygen and nutrients, hence overcoming the limitations of static culture and improving matrix deposition. Here, we combined an optimized cocktail of soluble factors, the BIT (BMP-2, Insulin, Thyroxin), and clinical-grade collagen sponges with a bidirectional perfusion bioreactor, namely the oscillating perfusion bioreactor (OPB), to engineer in vitro articular cartilage by human articular chondrocytes (HACs) obtained from osteoarthritic patients. After amplification, HACs were seeded and cultivated in collagen sponges either in static or dynamic conditions. Chondrocyte phenotype and the nature of the matrix synthesized by HACs were assessed using western blotting and immunohistochemistry analyses. Finally, the stability of the cartilaginous tissue produced by HACs was evaluated in vivo by subcutaneous implantation in nude mice. Our results showed that perfusion improved the distribution and quality of cartilaginous matrix deposited within the sponges, compared to static conditions. Specifically, dynamic culture in the OPB, in combination with the BIT cocktail, resulted in the homogeneous production of extracellular matrix rich in type II collagen. Remarkably, the production of type I collagen, a marker of fibrous tissues, was also inhibited, indicating that the association of the OPB with the BIT cocktail limits fibrocartilage formation, favoring the reconstruction of hyaline cartilage. PMID:27584727

  3. Expression of silicatein and collagen genes in the marine sponge Suberites domuncula is controlled by silicate and myotrophin.

    PubMed

    Krasko, A; Lorenz, B; Batel, R; Schröder, H C; Müller, I M; Müller, W E

    2000-08-01

    The major skeletal elements in the (Porifera) sponges, are spicules formed from inorganic material. The spicules in the Demospongiae class are composed of hydrated, amorphous silica. Recently an enzyme, silicatein, which polymerizes alkoxide substrates to silica was described from the sponge Tethya aurantia. In the present study the cDNA encoding silicatein was isolated from the sponge Suberites domuncula. The deduced polypeptide comprises 331 amino acids and has a calculated size of Mr 36 306. This cDNA was used as a probe to study the potential role of silicate on the expression of the silicatein gene. For these studies, primmorphs, a special form of aggregates composed of proliferating cells, have been used. It was found that after increasing the concentration of soluble silicate in the seawater medium from around 1 microM to approximately 60 microM, this gene is strongly upregulated. Without additional silicate only a very weak expression could be measured. Because silica as well as collagen are required for the formation of spicules, the expression of the gene encoding collagen was measured in parallel. It was also found that the level of transcripts for collagen strongly increases in the presence of 60 microM soluble silicate. In addition, it is demonstrated that the expression of collagen is also upregulated in those primmorphs which were treated with recombinant myotrophin obtained from the same sponge. Myotrophin, however, had no effect on the expression of silicatein. From these data we conclude that silicate influences the expression of the enzyme silicatein and also the expression of collagen, (via the mediator myotrophin). PMID:10903523

  4. Sponge

    2011-11-15

    Sponge provides a web interface to Pulp (http://pulpproject.org/) that implements a particular workflow as described in the paper “Staging Package Deployment via Repository Management” (http://www.usenix.org/events/lisa11/tech/full_papers/Pierre.pdf). Namely, it implements a process for intensive management of software repositories to apply more deterministic updates to clients of those repositories.

  5. Chitosan/gelatin composite sponge is an absorbable surgical hemostatic agent.

    PubMed

    Lan, Guangqian; Lu, Bitao; Wang, Tianyou; Wang, Lijuan; Chen, Jinghao; Yu, Kun; Liu, Jiawei; Dai, Fangying; Wu, Dayang

    2015-12-01

    Chitosan is a versatile biological material that is very well known for its hemostatic properties. The purpose of this study was to test the hemostatic properties of a chitosan composite obtained from silkworm pupae and gelatin. This spongy porous material was cross-linked with tannins and then freeze-dried under vacuum to obtain composites containing chitosan and gelatin in different proportions. Results showed that the best blood-clotting index (BCI) was achieved in vitro by a chitosan/gelatin sponge (CG) ratio of 5/5 (W/W). Furthermore, CG had the best hemostatic effect in rabbit artery bleeding and liver model tests compared to the two components separately. The better hemostatic effect of CG may be due to its ability to absorb blood platelets easily and to the higher liquid adsorption ratio. However, no obvious differences were observed in thrombin generation with both aPTT and PT tests. Cell toxicity tests with L929 cells showed that CG caused no obvious cytotoxicity. In addition, subcutaneous transplantation of CG into rabbits resulted in almost complete degradation of CG after 6 weeks, together with rich vascular generation and proliferation in the transplanted region. Thus, CG can be considered an effective absorbable hemostatic material. PMID:26590895

  6. Pichia pastoris production of a prolyl 4-hydroxylase derived from Chondrosia reniformis sponge: A new biotechnological tool for the recombinant production of marine collagen.

    PubMed

    Pozzolini, Marina; Scarfì, Sonia; Mussino, Francesca; Salis, Annalisa; Damonte, Gianluca; Benatti, Umberto; Giovine, Marco

    2015-08-20

    Prolyl 4-hydroxylase (P4H) is a α2β2 tetramer catalyzing the post-translational hydroxylation of prolines in collagen. Its recombinant production is mainly pursued to realize biotechnological tools able to generate animal contaminant-free hydroxylated collagen. One promising candidate for biomedical applications is the collagen extracted from the marine sponge Chondrosia reniformis, because of its biocompatibility and because is devoid of the health risks associated with bovine and porcine collagens. Here we report on the production and selection, by enzymatic and biomolecular analyses, of a triple transformed Pichia pastoris strain expressing a stable P4H tetramer derived from C. reniformis sponge and a hydroxylated non fibrillar procollagen polypeptide from the same animal. The percentage of recombinant procollagen hydroxylated prolines inside the transformed yeast was of 36.3% analyzed by mass spectrometry indicating that the recombinant enzyme is active on its natural substrate inside the yeast cell host. Furthermore, the recombinant sponge P4H has the ability to hydroxylate its natural substrate in both X and Y positions in the Xaa-Yaa-Gly collagenous triplets. In conclusion this Pichia system seems ideal for high-level production of hydroxylated sponge- or marine-derived collagen polypeptides as well as of conotoxins or other marine proteins of high pharmacological interest needing this particular post-translational modification. PMID:26022422

  7. Local administration of gentamicin collagen sponge in surgical excision of sacrococcygeal pilonidal sinus disease: a systematic review and meta-analysis of the literature.

    PubMed

    Nguyen, A L; Pronk, A A; Furnée, E J B; Pronk, A; Davids, P H P; Smakman, N

    2016-02-01

    Surgical site infections occur in up to 24 % of patients after surgical excision of sacrococcygeal pilonidal sinus disease with primary wound closure. Local administration of antibiotics by a gentamicin collagen sponge could reduce this infection rate. The objective of this systematic review and meta-analysis was to evaluate the effect of a gentamicin collagen sponge on outcome after surgical excision in patients with sacrococcygeal pilonidal sinus disease. A structured literature search was performed in the PubMed, Embase, The Cochrane Library, and Scopus databases. Studies comparing surgical excision of sacrococcygeal pilonidal sinus disease with versus without a gentamicin collagen sponge were included. Outcome measures were surgical site infection, wound healing, and recurrence. The search strategy yielded six studies with a total of 669 patients. Three randomized controlled trials, comparing excision of pilonidal sinus disease and primary wound closure with versus without gentamicin collagen sponge, were eligible for inclusion in the meta-analysis (319 patients), demonstrating a trend towards reduced surgical site infections after administration of gentamicin collagen sponge [absolute risk reduction 20 %, 95 %-confidence interval (CI) 1-41 %, p = 0.06]. The wound healing (absolute risk reduction 22 %, 95 % CI 32-77 %, p = 0.42) and recurrence rate (absolute risk reduction 8 %, 95 % CI 7-22 %, p = 0.30) were not significantly different between both groups. Administration of a gentamicin collagen sponge after surgical excision of sacrococcygeal pilonidal sinus disease showed no significant influence on wound healing and recurrence rate, but a trend towards a reduced incidence of surgical site infections. Therefore, additional larger well-designed randomized controlled trials are required. PMID:26546004

  8. A three-dimensional collagen-sponge-based culture system coated with simplified recombinant fibronectin improves the function of a hepatocyte cell line.

    PubMed

    Nishida, Yuuki; Taniguchi, Akiyoshi

    2016-03-01

    Hepatocytes are widely used in pharmaceutical drug discovery tests, but their hepatic functions decrease rapidly during in vitro culture. Many culture systems have been devised to address this problem. We here report that a three-dimensional (3D) collagen-based scaffold coated with simplified recombinant fibronectin (FN) enhanced the function of a hepatocyte cell line. The developed culture system uses a honeycomb collagen sponge coated with collagen-binding domain (CBD)-cell attachment site (CAS), a chimeric protein comprising the CBD and CAS of FN. The function of HepG2 cells grown on honeycomb collagen sponge coated with CBD-CAS was investigated by determining the messenger RNA (mRNA) expression levels of several genes. The mRNA expression level of albumin increased 3.25 times in cells grown on CBD-CAS-coated honeycomb collagen sponge for 3 days; the expression level of CCAAT/enhancer binding protein (C/EBPα) increased 40-fold after 1 d and up to 150-fold after 3 d. These results suggested that CBD-CAS-coated honeycomb collagen sponge could improve the functions of hepatocytes by inducing C/EBPα expression. The activation of cytochrome P450 (CYP) enzymes in HepG2 cells grown on CBD-CAS-coated honeycomb collagen sponge was measured at the mRNA level and was found to increase between two and six times compared to cells grown without the CBD-CAS coating, showing that this culture system induced CYP gene expression and thus may be useful in drug metabolism assays. PMID:26714750

  9. Gentamicin-Impregnated Collagen Sponge: Effectiveness in Preventing Sternal Wound Infection in High-Risk Cardiac Surgery

    PubMed Central

    Rapetto, Filippo; Bruno, Vito D.; Guida, Gustavo; Marsico, Roberto; Chivasso, Pierpaolo; Zebele, Carlo

    2016-01-01

    Sternal wound infections represent one of the most frequent complications after cardiac surgery and are associated with high postoperative mortality. Several preventive methods have been introduced, and recently, gentamicin-impregnated collagen sponges (GICSs) have shown a promising effect in reducing the incidence of this type of complications. Gentamicin is an aminoglycoside antibiotic that has been widely used to treat infections caused by multiresistant bacteria; despite its effectiveness, its systemic use carries a risk of toxicity. GICSs appear to overcome this side effect, topically delivering high antibiotic concentrations to the wound and thus reducing the toxic-related events. Although several retrospective analyses and randomized controlled trials have studied the use of GICSs in cardiac surgery, conclusions regarding their efficacy in preventing sternal wound infection are inconsistent. We have reviewed the current literature focusing on high-risk patients. PMID:27279734

  10. Evaluation of a wound dressing composed of hyaluronic acid and collagen sponge containing epidermal growth factor in diabetic mice.

    PubMed

    Kondo, Shinya; Niiyama, Hayato; Yu, Akane; Kuroyanagi, Yoshimitsu

    2012-01-01

    This study investigated the effect of a wound dressing composed of hyaluronic acid (HA) and collagen (Col) sponge containing epidermal growth factor (EGF) on wound healing in diabetic mice. High-molecular-weight (HMW) HA aqueous solution, hydrolyzed low-molecular-weight (LMW) HA aqueous solution and heat-denatured Col aqueous solution were mixed, followed by freeze-drying to obtain a spongy sheet. Cross-linkage between Col molecules was induced by UV irradiation to the spongy sheet (Type-I wound dressing). In a similar manner, a spongy sheet containing EGF (Type-II wound dressing) was prepared by freeze-drying the mixed solution of HMW-HA, LMW-HA and Col containing EGF. The efficacy of these products was evaluated in type-II diabetic BKS.Cg-+Lepr(db)/+Lepr(db) (db/db) mice. Wound dressings were applied to a full-thickness, dorsal skin defect measuring 1.5 cm × 2.0 cm, showing adipose tissue. In the control group, a commercially available artificial dermis composed of collagen spongy sheet (TERUDERMIS(®)) was used. A commercially available polyurethane film dressing (Bioclusive(®)) was applied over each wound dressing. After 1 week of application, wound conditions were evaluated based on their gross and histological appearances. Type-I and -II wound dressings promoted a decrease in wound size associated with angiogenesis and granulation tissue formation, compared with the artificial dermis. In particular, Type-II wound dressings promoted sufficient re-epithelialization. These findings indicate that the combination of HA, Col and EGF promotes wound healing by stimulating cell activity including cell migration and proliferation on the adipose tissue in a diabetic wound. Type-I and -II wound dressings would be useful to prepare a well-vascularized wound bed acceptable for split-thickness auto-skin grafting. PMID:21943516

  11. Change in the amount of epsilon-hexosyllysine, UV absorbance, and fluorescence of collagen with age in different animal species

    SciTech Connect

    Miksik, I.; Deyl, Z. )

    1991-05-01

    Skin and aorta collagen specimens of Wistar rats, white mice, beagle dogs, cats, horses, and human necropsies of different ages were examined with respect to the content of glycated products. The data presented show that (a) glycation and accumulation of the chromophore(s) are comparable in collagen samples from different species of comparable age; (b) glycation and pigmented accumulation increase markedly during the first 5-10 years of age; (c) the extent of glycation is different in different tissues (in particular, glycation of aortal collagen is about twice that of skin collagen); and (d) collagen pigmentation as followed by fluorescence is comparable in aortal and skin collagen (except below 10 years); pigmentation measured by absorbance at 350 nm is, on the contrary, lower in aortal than in skin collagen. Based on the assumption of constant blood glucose level during the life span, it appears feasible to conclude that the degree of nonenzymatic collagen glycation reflects the time period for which the protein was exposed to the action of sugars. This period, because of increased cross-linking, is likely to be extended in older animals. Other factors, such as differences in collagen turnover between different tissues and the intensity of the removal process of the glycated products, should be taken into consideration as well.

  12. Maxillary sinus augmentation using recombinant bone morphogenetic protein-2/acellular collagen sponge in combination with a mineralized bone replacement graft: a report of three cases.

    PubMed

    Tarnow, Dennis P; Wallace, Stephen S; Testori, Tiziano; Froum, Stuart J; Motroni, Alessandro; Prasad, Hari S

    2010-04-01

    The objective of the following case reports was to assess whether mineralized bone replacement grafts (eg, xenografts and allografts) could be added to recombinant human bone morphogenetic protein-2/acellular collagen sponge (rhBMP-2/ACS) in an effective manner that would: (1) reduce the graft shrinkage observed when using rhBMP-2/ACS alone, (2) reduce the volume and dose of rhBMP-2 required, and (3) preserve the osteoinductivity that rhBMP-2/ACS has shown when used alone. The primary outcome measures were histomorphometric analysis of vital bone production and analysis of serial computed tomographic scans to determine changes in bone graft density and stability. Over the 6-month course of this investigation, bone graft densities tended to increase (moreso with the xenograft than the allograft). The increased density in allograft cases was likely the result of both compression of the mineralized bone replacement graft and vital bone formation, seen histologically. Loss of volume was greater with the four-sponge dose than the two-sponge dose because of compression and resorption of the sponges. Vital bone formation in the allograft cases ranged from 36% to 53% but, because of the small sample size, it was not possible to determine any significant difference between the 5.6 mL (four-sponge) dose and the 2.8 mL (two-sponge) dose. Histology revealed robust new woven bone formation with only minimal traces of residual allograft, which appeared to have undergone accelerated remodeling or rhBMP-2-mediated resorption. PMID:20228973

  13. Sponge coring apparatus with reinforced sponge

    SciTech Connect

    Park, A.; Wilson, B. T.

    1985-03-05

    A well coring apparatus includes an outer barrel and an inner barrel. A hollow sponge is disposed along a liner for insertion into the inner barrel. The sponge is operable to absorb subterranean fluid from a well core. A plurality of reinforcing members are disposed on the inner surface of the liner to prevent movement of the sponge with respect thereto. A plurality of orifices are disposed in the surface of the liner to allow gas and/or fluid to escape from the interior thereof when the subterranean fluid contained within the core bleeds into the sponge.

  14. Hypoxia pretreatment of bone marrow-derived mesenchymal stem cells seeded in a collagen-chitosan sponge scaffold promotes skin wound healing in diabetic rats with hindlimb ischemia.

    PubMed

    Tong, Chuan; Hao, Haojie; Xia, Lei; Liu, Jiejie; Ti, Dongdong; Dong, Liang; Hou, Qian; Song, Haijing; Liu, Huiling; Zhao, Yali; Fu, Xiaobing; Han, Weidong

    2016-01-01

    Bone marrow-derived mesenchymal stem cells (BM-MSCs) have properties that make them promising for the treatment of chronic nonhealing wounds. The major challenge is ensuring an efficient, safe, and painless delivery of BM-MSCs. Tissue-engineered skin substitutes have considerable benefits in skin damage resulting from chronic nonhealing wounds. Here, we have constructed a three-dimensional biomimetic scaffold known as collagen-chitosan sponge scaffolds (CCSS) using the cross-linking and freeze-drying method. Scanning electron microscopy images showed that CCSS had an interconnected network pore configuration about 100 μm and exhibited a suitable swelling ratio for maintaining morphological stability and appropriate biodegradability to improve biostability using swelling and degradation assays. Furthermore, BM-MSCs were seeded in CCSS using the two-step seeding method to construct tissue-engineered skin substitutes. In addition, in this three-dimensional biomimetic CCSS, BM-MSCs secreted their own collagen and maintain favorable survival ability and viability. Importantly, BM-MSCs exhibited a significant upregulated expression of proangiogenesis factors, including HIF-1α, VEGF, and PDGF following hypoxia pretreatment. In vivo, hypoxia pretreatment of the skin substitute observably accelerated wound closure via the reduction of inflammation and enhanced angiogenesis in diabetic rats with hindlimb ischemia. Thus, hypoxia pretreatment of the skin substitutes can serve as ideal bioengineering skin substitutes to promote optimal diabetic skin wound healing. PMID:26463737

  15. 21 CFR 886.4790 - Ophthalmic sponge.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Ophthalmic sponge. 886.4790 Section 886.4790 Food... DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4790 Ophthalmic sponge. (a) Identification. An ophthalmic sponge is a device that is an absorbant sponge, pad, or spear made of folded gauze,...

  16. 21 CFR 886.4790 - Ophthalmic sponge.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Ophthalmic sponge. 886.4790 Section 886.4790 Food... DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4790 Ophthalmic sponge. (a) Identification. An ophthalmic sponge is a device that is an absorbant sponge, pad, or spear made of folded gauze,...

  17. 21 CFR 886.4790 - Ophthalmic sponge.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic sponge. 886.4790 Section 886.4790 Food... DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4790 Ophthalmic sponge. (a) Identification. An ophthalmic sponge is a device that is an absorbant sponge, pad, or spear made of folded gauze,...

  18. 21 CFR 886.4790 - Ophthalmic sponge.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Ophthalmic sponge. 886.4790 Section 886.4790 Food... DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4790 Ophthalmic sponge. (a) Identification. An ophthalmic sponge is a device that is an absorbant sponge, pad, or spear made of folded gauze,...

  19. 21 CFR 886.4790 - Ophthalmic sponge.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Ophthalmic sponge. 886.4790 Section 886.4790 Food... DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4790 Ophthalmic sponge. (a) Identification. An ophthalmic sponge is a device that is an absorbant sponge, pad, or spear made of folded gauze,...

  20. Controlled release of thymosin beta 4 using a collagen-chitosan sponge scaffold augments cutaneous wound healing and increases angiogenesis in diabetic rats with hindlimb ischemia.

    PubMed

    Ti, Dongdong; Hao, Haojie; Xia, Lei; Tong, Chuan; Liu, Jiejie; Dong, Liang; Xu, Shenjun; Zhao, Yali; Liu, Huiling; Fu, Xiaobing; Han, Weidong

    2015-02-01

    It is important to establish an efficient vascularization for the long-term acceptance of bioengineered skin equivalents treating the cutaneous wounds of diabetic rats with hindlimb ischemia. This study investigates the possible use of a collagen-chitosan sponge scaffold encapsulated with thymosin beta 4 (CCSS-eTβ4), an angiogenic factor, to accelerate cutaneous wound healing in streptozotocin (STZ)-induced diabetic rats with hindlimb ischemia. CCSSs-eTβ4 was fabricated using a freeze-drying method. The scaffolds were analyzed by scanning electron microscopy, swelling and degradation assays, mechanical properties, and scaffolds of 50:50 collagen-chitosan were selected and applied. The controlled release of Tβ4 from the scaffolds elicited localized and prolonged effects over 12 days, as shown by an enzyme-linked immunosorbent assay (ELISA). In vivo, CCSSs-eTβ4 improved diabetic cutaneous wound healing, with faster wound reepithelialization, better dermal reorganization, and higher wound vascularization. Furthermore, CCSSs-eTβ4 downregulated inflammatory genes and upregulated angiogenic genes in the wound tissue. Significant increases in CD31-positive endothelial cells and new vessel density were also observed. In vitro, Tβ4 increased the migratory and proliferative activity of high glucose (HG)-treated human umbilical vein endothelial cells (HUVECs). Meanwhile, we found that Tβ4 could promote HG-treated HUVECs migration and improve angiogenesis by activation of the VEGF/AKT pathway. Overall, these findings demonstrated the promising potential of CCSSs-eTβ4 to promote more effective wound healing and suggest its possible application for diabetic cutaneous wound treatment. PMID:25204972

  1. The Effect of Interferon-γ and Zoledronate Treatment on Alpha-Tricalcium Phosphate/Collagen Sponge-Mediated Bone-Tissue Engineering

    PubMed Central

    Li, Peiqi; Hashimoto, Yoshiya; Honda, Yoshitomo; Arima, Yoshiyuki; Matsumoto, Naoyuki

    2015-01-01

    Inflammatory responses are frequently associated with the expression of inflammatory cytokines and severe osteoclastogenesis, which significantly affect the efficacy of biomaterials. Recent findings have suggested that interferon (IFN)-γ and zoledronate (Zol) are effective inhibitors of osteoclastogenesis. However, little is known regarding the utility of IFN-γ and Zol in bone tissue engineering. In this study, we generated rat models by generating critically sized defects in calvarias implanted with an alpha-tricalcium phosphate/collagen sponge (α-TCP/CS). At four weeks post-implantation, the rats were divided into IFN-γ, Zol, and control (no treatment) groups. Compared with the control group, the IFN-γ and Zol groups showed remarkable attenuation of severe osteoclastogenesis, leading to a significant enhancement in bone mass. Histomorphometric data and mRNA expression patterns in IFN-γ and Zol-injected rats reflected high bone-turnover with increased bone formation, a reduction in osteoclast numbers, and tumor necrosis factor-α expression. Our results demonstrated that the administration of IFN-γ and Zol enhanced bone regeneration of α-TCP/CS implants by enhancing bone formation, while hampering excess bone resorption. PMID:26516841

  2. 21 CFR 880.2740 - Surgical sponge scale.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Surgical sponge scale. 880.2740 Section 880.2740... Devices § 880.2740 Surgical sponge scale. (a) Identification. A surgical sponge scale is a nonelectrically powered device used to weigh surgical sponges that have been used to absorb blood during surgery so...

  3. 21 CFR 880.2740 - Surgical sponge scale.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Surgical sponge scale. 880.2740 Section 880.2740... Devices § 880.2740 Surgical sponge scale. (a) Identification. A surgical sponge scale is a nonelectrically powered device used to weigh surgical sponges that have been used to absorb blood during surgery so...

  4. 21 CFR 880.2740 - Surgical sponge scale.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Surgical sponge scale. 880.2740 Section 880.2740... Devices § 880.2740 Surgical sponge scale. (a) Identification. A surgical sponge scale is a nonelectrically powered device used to weigh surgical sponges that have been used to absorb blood during surgery so...

  5. 21 CFR 880.2740 - Surgical sponge scale.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Surgical sponge scale. 880.2740 Section 880.2740... Devices § 880.2740 Surgical sponge scale. (a) Identification. A surgical sponge scale is a nonelectrically powered device used to weigh surgical sponges that have been used to absorb blood during surgery so...

  6. 21 CFR 880.2740 - Surgical sponge scale.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Surgical sponge scale. 880.2740 Section 880.2740... Devices § 880.2740 Surgical sponge scale. (a) Identification. A surgical sponge scale is a nonelectrically powered device used to weigh surgical sponges that have been used to absorb blood during surgery so...

  7. Biomedical applications of collagens.

    PubMed

    Ramshaw, John A M

    2016-05-01

    Collagen-based biomedical materials have developed into important, clinically effective materials used in a range of devices that have gained wide acceptance. These devices come with collagen in various formats, including those based on stabilized natural tissues, those that are based on extracted and purified collagens, and designed composite, biosynthetic materials. Further knowledge on the structure and function of collagens has led to on-going developments and improvements. Among these developments has been the production of recombinant collagen materials that are well defined and are disease free. Most recently, a group of bacterial, non-animal collagens has emerged that may provide an excellent, novel source of collagen for use in biomaterials and other applications. These newer collagens are discussed in detail. They can be modified to direct their function, and they can be fabricated into various formats, including films and sponges, while solutions can also be adapted for use in surface coating technologies. PMID:26448097

  8. Experience from the use of absorbable type I collagen as haemostatic agent in obstetric and gynecological operations

    PubMed Central

    Karagiannis, V; Daniilidis, A; Rousso, D; Palapelas, V; Karagiannis, T; Kiskinis, D

    2006-01-01

    During the third stage of labour there are a lot of causes of significant hemorrhage. The commonest causes of acute hemorrhage are the uterine atony, the retained placenta, the lower tract lacerations, uterine rupture, placenta accreta, hereditary coagulopathy. Also, there could be significant bleeding, during caesarian section, usually at the time of removal of the placenta in cases of low lying placenta or placenta previa. A lot of times we have to confront serious hemorrhages in gynecological procedures like hysterectomies in cases of cervical, uterine or ovarian cancers. In order to deal with these problems successfully, general and specific measures are being taken. In cases of atonic uterus when all the other methods are unsuccessful we have to proceed to ligation of the internal iliac artery or even hysterectomy. Material-Methods: We have tried to use the hemostatic type I collagen in obstetrical and gynecological cases in order to control the bleeding. We have used the collagen type I totally in 8 cases. Five of them were cases of atonic uterus after normal delivery or caesarian section and three of them were gynecological cases of uterine fibroids and ovarian cancer. Results: By placing the collagen type I over the bleeding surfaces we have realized that in a very short period of time, there has been satisfactory control of the bleeding and immediate clinical improvement of the patient. In four out of five obstetrical cases that we have used the type I collagen, we have managed to avoid the hysterectomy. PMID:22087058

  9. Vaginal sponge and spermicides

    MedlinePlus

    Birth control - over the counter; Contraceptives - over the counter ... include irritation and allergic reactions. VAGINAL SPONGE Vaginal contraceptive sponges are soft sponges covered with a spermicide. ...

  10. Histological and histomorphometric analysis of animal experimental dehiscence defect treated with three bio absorbable GTR collagen membrane

    PubMed Central

    Behfarnia, Parichehr; Khorasani, Mitra Mohammad; Birang, Reza; Abbas, Fateme Mashhadi

    2012-01-01

    Background: Guided tissue regeneration (GTR) allows mesenchymal cells to repopulate the defects. However, there is limited information regarding the efficacy of different membranes. The present study was designed to histologically and histomorphometrically compare three collagen membranes in regenerative treatment of dehiscence defects in dogs. Materials and Methods: This 8 weeks experimental animal study comprised 4 healthy dogs. 5 × 5 mm periodontal dehiscences were created in each side of the mandible (4 dehiscences in each side of dogs’ mandible). In each side, one dehiscence defect was left uncovered as a control site and three other sites were randomly covered with different collagen membranes (Biogide (BG), Biomend (BM), and Cytoplast (CYT)). Histomorphometric and histologic analysis were conducted at 4 and 8 weeks. Data were analyzed using ANOVA, Mann-Withney, Kruskal-Wallis and Fisher 's exact tests (α = 0.05). Results: According to histomorphometric analysis there was a significant difference between treatment and control groups regarding the bone formation and the distance between the reference point and apical end of junctional epithelium (DJE) (P < 0.05). At 4 weeks, the maximum amount of bone thickness and height was observed in BG and CYT respectively, and this maximum rate was seen with the use of BG at 8 weeks. It was shown that DJE reached its highest rate in BM and CYT at 4 and 8 weeks, respectively. Organized PDL was formed in treatment groups. Conclusion: The membrane-treated groups had a statistically significant increase in bone formation and connective tissue attachment compared to control groups. However, there are some differences among experimental groups, which should be considered in GTR treatments. PMID:23559922

  11. Cytotoxic evaluation of biomechanically improved crosslinked ovine collagen on human dermal fibroblasts.

    PubMed

    Awang, M A; Firdaus, M A B; Busra, M B; Chowdhury, S R; Fadilah, N R; Wan Hamirul, W K; Reusmaazran, M Y; Aminuddin, M Y; Ruszymah, B H I

    2014-01-01

    Earlier studies in our laboratory demonstrated that collagen extracted from ovine tendon is biocompatible towards human dermal fibroblast. To be able to use this collagen as a scaffold in skin tissue engineering, a mechanically stronger scaffold is required that can withstand manipulation before transplantation. This study was conducted to improve the mechanical strength of this collagen sponge using chemical crosslinkers, and evaluate their effect on physical, chemical and biocompatible properties. Collagen sponge was crosslinked with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and glutaraldehyde (GA). Tensile test, FTIR study and mercury porosimetry were used to evaluate mechanical properties, chemical property and porosity, respectively. MTT assay was performed to evaluate the cytotoxic effect of crosslinked collagen sponge on human dermal fibroblasts. The FTIR study confirmed the successful crosslinking of collagen sponge. Crosslinking with EDC and GA significantly increased the mechanical strength of collagen sponge, with GA being more superior. Crosslinking of collagen sponge significantly reduced the porosity and the effect was predominant in GA-crosslinked collagen sponge. The GA-crosslinked collagen showed significantly lower, 60% cell viability towards human dermal fibroblasts compared to that of EDC-crosslinked collagen, 80% and non-crosslinked collagen, 100%. Although the mechanical strength was better when using GA but the more toxic effect on dermal fibroblast makes EDC a more suitable crosslinker for future skin tissue engineering. PMID:24948455

  12. Cells Behave Distinctly Within Sponges and Hydrogels Due to Differences of Internal Structure

    PubMed Central

    Zhang, Jingjing; Yang, Zheng; Li, Chao; Dou, Yana; Li, Yijiang; Thote, Tanushree; Wang, Dong-an

    2013-01-01

    Different forms of biomaterials, including microspheres, sponges, hydrogels, and nanofibers, have been broadly used in cartilage regeneration; however, effects of internal structures of the biomaterials on cells and chondrogenesis remain largely unexplored. We hypothesized that different internal structures of sponges and hydrogels led to phenotypic disparity of the cells and may lead to disparate chondrogenesis. In the current study, the chondrocytes in sponges and hydrogels of chitosan were compared with regard to cell distribution, morphology, gene expression, and production of extracellular matrix. The chondrocytes clustered or attached to the materials with spindle morphologies in the sponges, while they distributed evenly with spherical morphologies in the hydrogels. The chondrocytes proliferated faster with elevated gene expression of collagen type I and down-regulated gene expression of aggracan in sponges, when compared with those in the hydrogels. However, there was no significant difference of the expression of collagen type II between these two scaffolds. Excretion of both glycosaminoglycan (GAG) and collagen type II increased with time in vitro, but there was no significant difference between the sponges and the hydrogels. There was no significant difference in secretion of GAG and collagen type II in the two scaffolds, while the levels of collagen type I and collagen type X were much higher in sponges compared with those in hydrogels during an in vivo study. Though the chondrocytes displayed different phenotypes in the sponges and hydrogels, they led to comparable chondrogenesis. An optimized design of the biomaterials could further improve chondrogenesis through enhancing functionalities of the chondrocytes. PMID:23614637

  13. Magnetic, superhydrophobic and durable silicone sponges and their applications in removal of organic pollutants from water.

    PubMed

    Li, Lingxiao; Li, Bucheng; Wu, Lei; Zhao, Xia; Zhang, Junping

    2014-07-25

    Porous silicone sponges are fabricated by polymerization of organosilanes in the presence of Fe3O4@silica nanoparticles. The sponges feature fast magnetic responsivity, superhydrophobicity/superoleophilicity, high compressibility and stability. The sponges can selectively absorb floating oils on a water surface, heavy oils under water and even emulsified oils. PMID:24909778

  14. DYNAPHORE, INC. FORAGER™ SPONGE TECHNOLOGY - INNOVATIVE TECHNOLOGY EVALUATION REPORT

    EPA Science Inventory

    The Forager™ Sponge is an open-celled cellulose sponge incorporating an amine-containing chelating polymer that selectively absorbs dissolved heavy metals from aqueous waste streams. The Developer states that the technology can be utilized to remove and concentrate heavy metals f...

  15. Magnetic Resonance Microscopy of Collagen Mineralization

    PubMed Central

    Chesnick, Ingrid E.; Mason, Jeffrey T.; Giuseppetti, Anthony A.; Eidelman, Naomi; Potter, Kimberlee

    2008-01-01

    A model mineralizing system was subjected to magnetic resonance microscopy to investigate how water proton transverse (T2) relaxation times and magnetization transfer ratios can be applied to monitor collagen mineralization. In our model system, a collagen sponge was mineralized with polymer-stabilized amorphous calcium carbonate. The lower hydration and water proton T2 values of collagen sponges during the initial mineralization phase were attributed to the replacement of the water within the collagen fibrils by amorphous calcium carbonate. The significant reduction in T2 values by day 6 (p < 0.001) was attributed to the appearance of mineral crystallites, which were also detected by x-ray diffraction and scanning electron microscopy. In the second phase, between days 6 and 13, magnetic resonance microscopy properties appear to plateau as amorphous calcium carbonate droplets began to coalesce within the intrafibrillar space of collagen. In the third phase, after day 15, the amorphous mineral phase crystallized, resulting in a reduction in the absolute intensity of the collagen diffraction pattern. We speculate that magnetization transfer ratio values for collagen sponges, with similar collagen contents, increased from 0.25 ± 0.02 for control strips to a maximum value of 0.31 ± 0.04 at day 15 (p = 0.03) because mineral crystals greatly reduce the mobility of the collagen fibrils. PMID:18487295

  16. DYNAPHORE, INC., FORAGER SPONGE TECHNOLOGY - INNOVATIVE TECHNOLOGY EVALUATION REPORT

    EPA Science Inventory

    The Forager Sponge is a volume reduction technology in which heavy metal contaminants from an aqueous medium are selectively concentrated into a smaller volume for facilitated disposal. he technology treats contaminated groundwater, surface voters and porous waters by absorbing d...

  17. SITE TECHNOLOGY CAPSULE: DYNAPHORE, INC., FORAGER SPONGE TECHNOLOGY

    EPA Science Inventory

    The Forager Sponge is a volume reduction technology in which heavy metal contaminants from an aqueous medium are selectively concentrated into a smaller volume for facilitated disposal. he technology treats contaminated groundwater, surface waters and porous waters by absorbing d...

  18. The crystalline sponge method updated

    PubMed Central

    Hoshino, Manabu; Khutia, Anupam; Xing, Hongzhu; Inokuma, Yasuhide; Fujita, Makoto

    2016-01-01

    Crystalline sponges are porous metal complexes that can absorb and orient common organic molecules in their pores and make them observable by conventional X-ray structure analysis (crystalline sponge method). In this study, all of the steps in the crystalline sponge method, including sponge crystal preparation, pore–solvent exchange, guest soaking, data collection and crystallographic analysis, are carefully examined and thoroughly optimized to provide reliable and meaningful chemical information as chemical crystallography. Major improvements in the method have been made in the guest-soaking and data-collection steps. In the soaking step, obtaining a high site occupancy of the guest is particularly important, and dominant parameters for guest soaking (e.g. temperature, time, concentration, solvents) therefore have to be optimized for every sample compound. When standard conditions do not work, a high-throughput method is useful for efficiently optimizing the soaking conditions. The X-ray experiments are also carefully re-examined. Significant improvement of the guest data quality is achieved by complete data collection at high angle regions. The appropriate disorder treatment of the most flexible ZnI2 portions of the host framework and refinement of the solvents filling the remaining void are also particularly important for obtaining better data quality. A benchmark test for the crystalline sponge method toward an achiral molecule is proposed with a guaiazulene guest, in which the guest structure (with ∼ 100% site occupancy) is refined without applying any restraints or constraints. The obtained data quality with R int = 0.0279 and R 1 = 0.0379 is comparable with that of current conventional crystallographic analysis for small molecules. Another benchmark test for this method toward a chiral molecule is also proposed with a santonin guest. The crystallographic data obtained [R int = 0.0421, R 1 = 0.0312, Flack (Parsons) = −0.0071 (11)] represents the

  19. The crystalline sponge method updated.

    PubMed

    Hoshino, Manabu; Khutia, Anupam; Xing, Hongzhu; Inokuma, Yasuhide; Fujita, Makoto

    2016-03-01

    Crystalline sponges are porous metal complexes that can absorb and orient common organic molecules in their pores and make them observable by conventional X-ray structure analysis (crystalline sponge method). In this study, all of the steps in the crystalline sponge method, including sponge crystal preparation, pore-solvent exchange, guest soaking, data collection and crystallographic analysis, are carefully examined and thoroughly optimized to provide reliable and meaningful chemical information as chemical crystallography. Major improvements in the method have been made in the guest-soaking and data-collection steps. In the soaking step, obtaining a high site occupancy of the guest is particularly important, and dominant parameters for guest soaking (e.g. temperature, time, concentration, solvents) therefore have to be optimized for every sample compound. When standard conditions do not work, a high-throughput method is useful for efficiently optimizing the soaking conditions. The X-ray experiments are also carefully re-examined. Significant improvement of the guest data quality is achieved by complete data collection at high angle regions. The appropriate disorder treatment of the most flexible ZnI2 portions of the host framework and refinement of the solvents filling the remaining void are also particularly important for obtaining better data quality. A benchmark test for the crystalline sponge method toward an achiral molecule is proposed with a guaiazulene guest, in which the guest structure (with ∼ 100% site occupancy) is refined without applying any restraints or constraints. The obtained data quality with R int = 0.0279 and R 1 = 0.0379 is comparable with that of current conventional crystallographic analysis for small molecules. Another benchmark test for this method toward a chiral molecule is also proposed with a santonin guest. The crystallographic data obtained [R int = 0.0421, R 1 = 0.0312, Flack (Parsons) = -0.0071 (11)] represents the

  20. Vaginal sponge and spermicides

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/004003.htm Vaginal sponge and spermicides To use the sharing features on this page, please enable JavaScript. Spermicides and vaginal sponges are two over-the-counter birth control methods ...

  1. Highly recyclable superhydrophobic sponge suitable for the selective sorption of high viscosity oil from water.

    PubMed

    Wang, Jintao; Geng, Guihong

    2015-08-15

    Inspired by the adhesion of marine mussels, a kind of superhydrophobic oil sorbent was successfully fabricated by robustly immobilizing the micro/nanostructure layer onto the sponge skeleton. The as-prepared sponges possess excellent hydrophobicity with the water contact angle of 154°, which enables the sponge to selectively absorb various oils floating on water surface. The oil sorption capacities of as-prepared sponge for a series of oils can reach 18.3-46.8g/g. The absorbed oil can be recovered by mechanical squeezing and the resulting sponge can be recycled more than 70 cycles while still keeping high oil sorption capability. More importantly, the obtained sponge has excellent affinity to the high viscosity oils. Therefore, the as-prepared sponge might find practical applications in the large-scale removal of oils especially high viscosity oils from water surface. PMID:26092604

  2. PGA-incorporated collagen: Toward a biodegradable composite scaffold for bone-tissue engineering.

    PubMed

    Toosi, Shirin; Naderi-Meshkin, Hojjat; Kalalinia, Fatemeh; Peivandi, Mohammad Taghi; HosseinKhani, Hossein; Bahrami, Ahmad Reza; Heirani-Tabasi, Asieh; Mirahmadi, Mahdi; Behravan, Javad

    2016-08-01

    Nowadays composite scaffolds based on synthetic and natural biomaterials have got attention to increase healing of non-union bone fractures. To this end, different aspects of collagen sponge incorporated with poly(glycolic acid) (PGA) fiber were investigated in this study. Collagen solution (6.33 mg/mL) with PGA fibers (collagen/fiber ratio [w/w]: 4.22, 2.11, 1.06, 0.52) was freeze-dried, followed by dehydrothermal cross-linking to obtain collagen sponge incorporating PGA fibers. Properties of scaffold for cell viability, proliferation, and differentiation of mesenchymal stem cells (MSCs) were evaluated. Scanning electron microscopy showed that collagen sponge exhibited an interconnected pore structure with an average pore size of 190 μm, irrespective of PGA fiber incorporation. The collagen-PGA sponge was superior to the original collagen sponge in terms of the initial attachment, proliferation rate, and osteogenic differentiation of the bone marrow-MSCs (BM-MSC). The shrinkage of sponges during cell culture was significantly suppressed by fiber incorporation. Incorporation of PGA fiber is a simple and promising way to reinforce collagen sponge without impairing biocompatibility. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2020-2028, 2016. PMID:27059133

  3. The evolution of fibrillar collagens: a sea-pen collagen shares common features with vertebrate type V collagen.

    PubMed

    Tillet, E; Franc, J M; Franc, S; Garrone, R

    1996-02-01

    The extracellular matrix of marine primitive invertebrates (sponges, polyps and jellyfishes) contains collagen fibrils with narrow diameters. From various data, it has been hypothesized that these primitive collagens could represent ancestral forms of the vertebrate minor collagens, i.e., types V or XI. Recently we have isolated a primitive collagen from the soft tissues of the sea-pen Veretillum cynomorium. This report examines whether the sea-pen collagen shares some features with vertebrate type V collagen. Rotary shadowed images of acid-soluble collagen molecules extracted from beta-APN treated animals, positive staining of segment-long-spacing crystallites precipitated from pepsinized collagen, Western blots of the pepsinized alpha1 and alpha2 chains with antibodies to vertebrate types I, III and V collagens, and in situ gold immunolabeling of ECM collagen fibrils were examined. Our results showed that the tissue form of the sea-pen collagen is a 340-nm threadlike molecule, which is close to the vertebrate type V collagen with its voluminous terminal globular domain, the distribution of most of its polar amino-acid residues, and its antigenic properties. PMID:8653581

  4. Collagen-Based Biomaterials for Wound Healing

    PubMed Central

    Chattopadhyay, Sayani; Raines, Ronald T.

    2014-01-01

    With its wide distribution in soft and hard connective tissues, collagen is the most abundant of animal proteins. In vitro, natural collagen can be formed into highly organized, three-dimensional scaffolds that are intrinsically biocompatible, biodegradable, non-toxic upon exogenous application, and endowed with high tensile strength. These attributes make collagen the material of choice for wound healing and tissue engineering applications. In this article, we review the structure and molecular interactions of collagen in vivo; the recent use of natural collagen in sponges, injectables, films and membranes, dressings, and skin grafts; and the on-going development of synthetic collagen mimetic peptides as pylons to anchor cytoactive agents in wound beds. PMID:24633807

  5. COLLAGEN PROCESSING

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Collagen dispersions, produced from fibrils recovered from milled bovine collagen, have shown promise in environmental remediation in applications as settling aids, filtration aids, fractionation media, oil drop stabilizers, and water purification aids. Macroporous structures, processed by controll...

  6. PLA-grafting of collagen chains leading to a biomaterial with mechanical performances useful in tendon regeneration.

    PubMed

    Bellini, Davide; Cencetti, Claudia; Sacchetta, Anna Cristina; Battista, Angela Maria; Martinelli, Andrea; Mazzucco, Laura; Scotto D'Abusco, Anna; Matricardi, Pietro

    2016-12-01

    With the aim to obtain a scaffold with improved mechanical properties with respect to collagen for tendon augmentation and regeneration, a novel collagen-based material was prepared via heterogeneous phase derivatization of type I collagen sponges using polylactic acid. Compared to the untreated collagen, the functionalized sponge (Coll-PLA) was characterized by higher tensile properties and lower swelling capability; the degradation rate of Coll-PLA, in the presence of collagenase, was lower than that of the untreated collagen sponge. These results are related to an increased hydrophobic character of the collagen matrix due to the presence of PLA chains. In vitro tests, performed with human primary fibroblasts, showed that cell adhesion and proliferation rate on Coll-PLA were comparable to those obtained with the non-functionalized collagen. These findings suggest that the new biomaterial could be suitable as scaffold in tendon augmentation and regeneration. PMID:27498425

  7. [Comparative animal experiment studies of the effect of exogenous collagen on healing of a deep skin wound].

    PubMed

    Sedlarik, K M; Schoots, C; Fidler, V; Oosterbaan, J A; Klopper, J P

    1991-02-01

    The high number of available wound dressings as well as the scientific reports about this topic indicates that the problem of an ideal wound dressing material is not jet solved. In the last 30 years lot of scientific reports about collagen as wound covering has been published. The positive effect of collagen by this application on a wound is well-known. We investigated the effect of a collagen sponge on healing of full thickness wound in rats. The animals were divided in two control and two experimental groups. In the control groups there were air exposed wounds as well as wounds covered with paraffin gauze. In the experimental groups the wounds were covered with natural reconstituted collagen sponge as well as with chemically prepared sponge. All results were compared. The wounds with collagen sponge covering healed significantly faster. Also the quality of the wound healing was better in the experimental groups. PMID:2042253

  8. The retained surgical sponge.

    PubMed Central

    Kaiser, C W; Friedman, S; Spurling, K P; Slowick, T; Kaiser, H A

    1996-01-01

    OBJECTIVE. A review was performed to investigate the frequency of occurrence and outcome of patients who have retained surgical sponges. METHODS. Closed case records from the files of the Medical Professional Mutual Insurance Company (ProMutual, Boston, MA) involving a claim of retained surgical sponges were reviewed for a 7-year period. RESULTS. Retained sponges occurred in 40 patients, comprising 48% of all closed claims for retained foreign bodies. A falsely correct sponge count after an abdominal procedure was documented in 76% of these claims. Ten percent of claims involved vaginal deliveries and minor non-body cavity procedures, for which no sponge count was performed. Total indemnity payments were $2,072,319, and defense costs were $572,079. In three cases, the surgeon was deemed responsible by the court despite the nursing staff's admitting liability and evidence presented that the surgeon complied completely with the standard of care. A wide range of indemnity payments was made despite a remarkable similarity of outcome in the patients studied. CONCLUSIONS. Despite the rarity of the reporting of a retained surgical sponge, this occurrence appears to be encountered more commonly than generally is appreciated. Operating teams should ensure that sponges be counted for all vaginal and any incisional procedures at risk for retaining a sponge. In addition, the surgeon should not unquestioningly accept correct count reports, but should develop the habit of performing a brief but thorough routine postprocedure wound/body cavity exploration before wound closure. The strikingly similar outcome for most patients would argue for a standardized indemnity payment being made without the need for adversarial legal procedures. PMID:8678622

  9. An experimental-finite element analysis on the kinetic energy absorption capacity of polyvinyl alcohol sponge.

    PubMed

    Karimi, Alireza; Navidbakhsh, Mahdi; Razaghi, Reza

    2014-06-01

    Polyvinyl alcohol (PVA) sponge is in widespread use for biomedical and tissue engineering applications owing to its biocompatibility, availability, relative cheapness, and excellent mechanical properties. This study reports a novel concept of design in energy absorbing materials which consist in the use of PVA sponge as an alternative reinforcement material to enhance the energy loss of impact loads. An experimental study is carried out to measure the mechanical properties of the PVA sponge under uniaxial loading. The kinetic energy absorption capacity of the PVA sponge is computed by a hexahedral finite element (FE) model of the steel ball and bullet through the LS-DYNA code under impact load at three different thicknesses (5, 10, 15mm). The results show that a higher sponge thickness invokes a higher energy loss of the steel ball and bullet. The highest energy loss of the steel ball and bullet is observed for the thickest sponge with 160 and 35J, respectively. The most common type of traumatic brain injury in which the head subject to impact load causes the brain to move within the skull and consequently brain hemorrhaging. These results suggest the application of the PVA sponge as a great kinetic energy absorber material compared to commonly used expanded polystyrene foams (EPS) to absorb most of the impact energy and reduces the transmitted load. The results might have implications not only for understanding of the mechanical properties of PVA sponge but also for use as an alternative reinforcement material in helmet and packaging material design. PMID:24863223

  10. Synthesis of a Novel Highly Oleophilic and Highly Hydrophobic Sponge for Rapid Oil Spill Cleanup.

    PubMed

    Khosravi, Maryam; Azizian, Saeid

    2015-11-18

    A highly hydrophobic and highly oleophilic sponge was synthesized by simple vapor-phase deposition followed by polymerization of polypyrrole followed by modification with palmitic acid. The prepared sponge shows high absorption capacity in the field of separation and removal of different oil spills from water surface and was able to emulsify oil/water mixtures. The sponge can be compressed repeatedly without collapsing. Therefore, absorbed oils can be readily collected by simple mechanical squeezing of the sponge. The prepared hydrophobic sponge can collect oil from water in both static and turbulent conditions. The proposed method is simple and low cost for the manufacture of highly oleophilic and highly hydrophobic sponges, which can be successfully used for effective oil-spill cleanup and water filtration. PMID:26496649

  11. Global conservation status of sponges.

    PubMed

    Bell, James J; McGrath, Emily; Biggerstaff, Andrew; Bates, Tracey; Cárdenas, César A; Bennett, Holly

    2015-02-01

    Sponges are important for maintaining ecosystem function and integrity of marine and freshwater benthic communities worldwide. Despite this, there has been no assessment of their current global conservation status. We assessed their status, accounting for the distribution of research effort; patterns of temporal variation in sponge populations and assemblages; the number of sponges on threatened species lists; and the impact of environmental pressures. Sponge research effort has been variable; marine sponges in the northeastern Atlantic and Mediterranean and freshwater sponges in Europe and North America have received the most attention. Although sponge abundance has increased in some locations since 1990, these were typically on coral reefs, in response to declines in other benthic organisms, and restricted to a few species. Few data were available on temporal trends in freshwater sponge abundance. Despite over 8500 described sponge species, only 20 are on threatened species lists, and all are marine species from the northeastern Atlantic and Mediterranean. Of the 202 studies identified, the effects of temperature, suspended sediment, substratum loss, and microbial pathogens have been studied the most intensively for marine sponges, although responses appear to be variable. There were 20 studies examining environmental impacts on freshwater sponges, and most of these were on temperature and heavy metal contamination. We found that most sponges do not appear to be threatened globally. However, little information is available for most species and more data are needed on the impacts of anthropogenic-related pressures. This is a critical information gap in understanding sponge conservation status. PMID:25599574

  12. Sustainable production of bioactive compounds from sponges: primmorphs as bioreactors.

    PubMed

    Schröder, H C; Brümmer, F; Fattorusso, E; Aiello, A; Menna, M; de Rosa, S; Batel, R; Müller, W E G

    2003-01-01

    Sponges [phylum Porifera] are a rich source for the isolation of biologically active and pharmacologically valuable compounds with a high potential to become effective drugs for therapeutic use. However, until now, only one compound has been introduced into clinics because of the limited amounts of starting material available for extraction. To overcome this serious problem in line with the rules for a sustainable use of marine resources, the following routes can be pursued; first, chemical synthesis, second, cultivation of sponges in the sea (mariculture), third, growth of sponge specimens in a bioreactor, and fourth, cultivation of sponge cells in vitro in a bioreactor. The main efforts to follow the latter strategy have been undertaken with the marine sponge Suberites domuncula. This species produces compounds that affect neuronal cells, such as quinolinic acid, a well-known neurotoxin, and phospholipids. A sponge cell culture was established after finding that single sponge cells require cell-cell contact in order to retain their telomerase activity, one prerequisite for continuous cell proliferation. The sponge cell culture system, the primmorphs, comprises proliferating cells that have the potency to differentiate. While improving the medium it was found that, besides growth factors, certain ions (e.g. silicate and iron) are essential. In the presence of silicate several genes required for the formation of the extracellular matrix are expressed (silicatein, collagen and myotrophin). Fe3+ is essential for the synthesis of the spicules, and causes an increased expression of the ferritin-, septin- and scavenger receptor genes. Furthermore, high water current is required for growth and canal formation in the primmorphs. The primmorph system has already been successfully used for the production of pharmacologically useful, bioactive compounds, such as avarol or (2'-5')oligoadenylates. Future strategies to improve the sponge cell culture are discussed; these

  13. Cryptochrome in Sponges

    PubMed Central

    Schröder, Heinz C.; Markl, Julia S.; Grebenjuk, Vlad A.; Korzhev, Michael; Steffen, Renate; Wang, Xiaohong

    2013-01-01

    Sponges (phylum: Porifera) react to external light or mechanical signals with contractile or metabolic reactions and are devoid of any nervous or muscular system. Furthermore, elements of a photoreception/phototransduction system exist in those animals. Recently, a cryptochrome-based photoreceptor system has been discovered in the demosponge. The assumption that in sponges the siliceous skeleton acts as a substitution for the lack of a nervous system and allows light signals to be transmitted through its glass fiber network is supported by the findings that the first spicules are efficient light waveguides and the second sponges have the enzymatic machinery for the generation of light. Now, we have identified/cloned in Suberites domuncula two additional potential molecules of the sponge cryptochrome photoreception system, the guanine nucleotide-binding protein β subunit, related to β-transducin, and the nitric oxide synthase (NOS)–interacting protein. Cryptochrome and NOSIP are light-inducible genes. The studies show that the NOS inhibitor L-NMMA impairs both morphogenesis and motility of the cells. Finally, we report that the function of primmorphs to produce reactive nitrogen species can be abolished by a NOS inhibitor. We propose that the sponge cryptochrome-based photoreception system, through which photon signals are converted into radicals, is coupled to the NOS apparatus. PMID:23920109

  14. Bioengineered collagens

    PubMed Central

    Ramshaw, John AM; Werkmeister, Jerome A; Dumsday, Geoff J

    2014-01-01

    Mammalian collagen has been widely used as a biomedical material. Nevertheless, there are still concerns about the variability between preparations, particularly with the possibility that the products may transmit animal-based diseases. Many groups have examined the possible application of bioengineered mammalian collagens. However, translating laboratory studies into large-scale manufacturing has often proved difficult, although certain yeast and plant systems seem effective. Production of full-length mammalian collagens, with the required secondary modification to give proline hydroxylation, has proved difficult in E. coli. However, recently, a new group of collagens, which have the characteristic triple helical structure of collagen, has been identified in bacteria. These proteins are stable without the need for hydroxyproline and are able to be produced and purified from E. coli in high yield. Initial studies indicate that they would be suitable for biomedical applications. PMID:24717980

  15. Magnetic, durable, and superhydrophobic polyurethane@Fe3O4@SiO2@fluoropolymer sponges for selective oil absorption and oil/water separation.

    PubMed

    Wu, Lei; Li, Lingxiao; Li, Bucheng; Zhang, Junping; Wang, Aiqin

    2015-03-01

    Magnetic, durable, and superhydrophobic polyurethane (PU) sponges were fabricated by chemical vapor deposition (CVD) of tetraethoxysilane (TEOS) to bind the Fe3O4 nanoparticles tightly on the sponge and then dip-coating in a fluoropolymer (FP) aqueous solution. The sponges were characterized using scanning electron microscopy and other analytical techniques. The effects of CVD time of TEOS and FP concentration on wettability, mechanical properties, oil absorbency, and oil/water selectivity of the sponges were also investigated. The sponges exhibit fast magnetic responsivity and excellent superhydrophobicity/superoleophilicity (CAwater = 157° and CAoil ≈ 0°). The sponges also show very high efficiency in oil/water separation and could, driven by a magnet, quickly absorb floating oils on the water surface and heavy oils under water. Moreover, the PU@Fe3O4@SiO2@FP sponges could be used as membranes for oil/water separation and for continuous separation of large amounts of oil pollutants from the water surface with the help of a pump. The in turn binding of Fe3O4 nanoparticles, SiO2, and FP can also improve mechanical properties of the PU sponge. The sponges maintain the superhydrophobicity even when they are stretched with 200% strain or compressed with 50% strain. The sponges also show excellent mechanical stability, oil stability, and reusability in terms of superhydrophobicity and oil absorbency. The magnetic, durable, and superhydrophobic PU sponges are very promising materials for practical oil absorption and oil/water separation. PMID:25671386

  16. Anticancer agents from marine sponges.

    PubMed

    Ye, Jianjun; Zhou, Feng; Al-Kareef, Ammar M Q; Wang, Hong

    2015-01-01

    Marine sponges are currently one of the richest sources of anticancer active compounds found in the marine ecosystems. More than 5300 different known metabolites are from sponges and their associated microorganisms. To survive in the complicated marine environment, most of the sponge species have evolved chemical means to defend against predation. Such chemical adaptation produces many biologically active secondary metabolites including anticancer agents. This review highlights novel secondary metabolites in sponges which inhibited diverse cancer species in the recent 5 years. These natural products of marine sponges are categorized based on various chemical characteristics. PMID:25402340

  17. Medullary Sponge Kidney

    MedlinePlus

    ... Association of Kidney Patients National Kidney Foundation MedlinePlus Kidney and Urologic Disease Organizations Many organizations provide support ... PDF, 345 KB)​​​​​ Alternate Language URL Medullary Sponge Kidney Page Content On this page: What is Medullary ...

  18. The Sponge Hologenome

    PubMed Central

    Thomas, Torsten

    2016-01-01

    ABSTRACT A paradigm shift has recently transformed the field of biological science; molecular advances have revealed how fundamentally important microorganisms are to many aspects of a host’s phenotype and evolution. In the process, an era of “holobiont” research has emerged to investigate the intricate network of interactions between a host and its symbiotic microbial consortia. Marine sponges are early-diverging metazoa known for hosting dense, specific, and often highly diverse microbial communities. Here we synthesize current thoughts about the environmental and evolutionary forces that influence the diversity, specificity, and distribution of microbial symbionts within the sponge holobiont, explore the physiological pathways that contribute to holobiont function, and describe the molecular mechanisms that underpin the establishment and maintenance of these symbiotic partnerships. The collective genomes of the sponge holobiont form the sponge hologenome, and we highlight how the forces that define a sponge’s phenotype in fact act on the genomic interplay between the different components of the holobiont. PMID:27103626

  19. Sodium alginate sponges with or without sodium hyaluronate: in vitro engineering of cartilage.

    PubMed

    Miralles, G; Baudoin, R; Dumas, D; Baptiste, D; Hubert, P; Stoltz, J F; Dellacherie, E; Mainard, D; Netter, P; Payan, E

    2001-11-01

    Studies are underway to design biosystems containing embedded chondrocytes to fill osteochondral defects and to produce a tissue close to native cartilage. In the present report, a new alginate three-dimensional support for chondrocyte culture is described. A sodium alginate solution, with or without hyaluronic acid (HA), was freeze-dried to obtain large-porosity sponges. This formulation was compared with a hydrogel of the same composition. In the sponge formulation, macroscopic and microscopic studies demonstrated the formation of a macroporous network (average pore size, 174 microm) associated with a microporous one (average pore size, 250 nm). Histological and biochemical studies showed that, when loaded with HA, the sponge provides an adapted environment for proteoglycan and collagen synthesis by chondrocytes. Cytoskeleton organization was studied by three-dimensional fluorescence microscopy (CellScan EPR). Chondrocytes exhibit a marked spherical shape with a nonoriented and sparse actin microfilament network. Type II collagen was detected in both types of sponges (with or without HA) using immunohistochemistry. In conclusion, the sponge formulation affords new perspectives with respect to the in vitro production of "artificial" cartilage. Furthermore, the presence of hyaluronate within the alginate sponge mimics a functional environment, suitable for the production by embedded chondrocytes of an extracellular matrix. PMID:11484190

  20. Review collagen-based biomaterials for wound healing.

    PubMed

    Chattopadhyay, Sayani; Raines, Ronald T

    2014-08-01

    With its wide distribution in soft and hard connective tissues, collagen is the most abundant of animal proteins. In vitro, natural collagen can be formed into highly organized, three-dimensional scaffolds that are intrinsically biocompatible, biodegradable, nontoxic upon exogenous application, and endowed with high tensile strength. These attributes make collagen the material of choice for wound healing and tissue engineering applications. In this article, we review the structure and molecular interactions of collagen in vivo; the recent use of natural collagen in sponges, injectables, films and membranes, dressings, and skin grafts; and the on-going development of synthetic collagen mimetic peptides as pylons to anchor cytoactive agents in wound beds. PMID:24633807

  1. Genetics Home Reference: white sponge nevus

    MedlinePlus

    ... Genetics Home Health Conditions white sponge nevus white sponge nevus Enable Javascript to view the expand/collapse ... Download PDF Open All Close All Description White sponge nevus is a condition characterized by the formation ...

  2. The unique invention of the siliceous sponges: their enzymatically made bio-silica skeleton.

    PubMed

    Müller, Werner E G; Wang, Xiaohong; Chen, Ailin; Hu, Shixue; Gan, Lu; Schröder, Heinz C; Schloßmacher, Ute; Wiens, Matthias

    2011-01-01

    Sponges are sessile filter feeders that, among the metazoans, evolved first on Earth. In the two classes of the siliceous sponges (the Demospongiae and the Hexactinellida), the complex filigreed body is stabilized by an inorganic skeleton composed of amorphous silica providing them a distinct body shape and plan. It is proposed that the key innovation that allowed the earliest metazoans to form larger specimens was the enzyme silicatein. This enzyme is crucial for the formation of the siliceous skeleton. The first sponge fossils with body preservation were dated back prior to the "Precambrian-Cambrian" boundary [Vendian (610-545 Ma)/Ediacaran (542-580 Ma)]. A further molecule required for the formation of a hard skeleton was collagen, fibrous organic filaments that need oxygen for their formation. Silicatein forming the spicules and collagen shaping their morphology are the two organic components that control the appositional growth of these skeletal elements. This process starts in both demosponges and hexactinellids intracellularly and is completed extracellularly where the spicules may reach sizes of up to 3 m. While the basic strategy of their formation is identical in both sponge classes, it differs on a substructural level. In Hexactinellida, the initial silica layers remain separated, those layers bio-fuse (bio-sinter) together in demosponges. In some sponge taxa, e.g., the freshwater sponges from the Lake Baikal, the individual spicules are embedded in an organic matrix that is composed of the DUF protein. This protein comprises clustered stretches of amino acid sequences composed of pronounced hydrophobic segments, each spanning around 35 aa. We concluded with the remark of Thompson (1942) highlighting that "the sponge-spicule is a typical illustration of the theory of 'bio-crystallisation' to form 'biocrystals' ein Mittelding between an inorganic crystal and an organic secretion." Moreover, the understanding of the enzymatic formation of the spicules

  3. Biomimetic silicification of demineralized hierarchical collagenous tissues

    PubMed Central

    Ryou, Heonjune; Diogenes, Anibal; Yiu, Cynthia K.Y.; Mazzoni, Annalisa; Chen, Ji-hua; Arola, Dwayne D.; Hargreaves, Kenneth M.; Pashley, David H.; Tay, Franklin R.

    2013-01-01

    Unlike man-made composite materials, natural biominerals containing composites usually demonstrate different levels of sophisticated hierarchical structures which are responsible for their mechanical properties and other metabolic functions. However, the complex spatial organizations of the organic-inorganic phases are far beyond what they be achieved by contemporary engineering techniques. Here, we demonstrate that carbonated apatite present in collagen matrices derived from fish scale and bovine bone may be replaced by amorphous silica, using an approach that simulates what is utilized by phylogenetically ancient glass sponges. The structural hierarchy of these collagen-based biomaterials is replicated by the infiltration and condensation of fluidic polymer-stabilized silicic acid precursors within the intrafibrillar milieu of type I collagen fibrils. This facile biomimetic silicification strategy may be used for fabricating silica-based, three-dimensional functional materials with specific morphological and hierarchical requirements. PMID:23586938

  4. Process for purifying zirconium sponge

    SciTech Connect

    Abodishish, H.A.M.; Kimball, L.S.

    1992-03-31

    This patent describes a Kroll reduction process wherein a zirconium sponge contaminated with unreacted magnesium and by-product magnesium chloride is produced as a regulus, a process for purifying the zirconium sponge. It comprises: distilling magnesium and magnesium chloride from: a regulus containing a zirconium sponge and magnesium and magnesium chloride at a temperature above about 800{degrees} C and at an absolute pressure less than about 10 mmHg in a distillation vessel to purify the zirconium sponge; condensing the magnesium and the magnesium chloride distilled from the zirconium sponge in a condenser; and then backfilling the vessel containing the zirconium sponge and the condenser containing the magnesium and the magnesium chloride with a gas; recirculating the gas between the vessel and the condenser to cool the zirconium sponge from above about 800{degrees} C to below about 300{degrees} C; and cooling the recirculating gas in the condenser containing the condensed magnesium and the condensed magnesium chloride as the gas cools the zirconium sponge to below about 300{degrees} C.

  5. Sponge systematics facing new challenges.

    PubMed

    Cárdenas, P; Pérez, T; Boury-Esnault, N

    2012-01-01

    Systematics is nowadays facing new challenges with the introduction of new concepts and new techniques. Compared to most other phyla, phylogenetic relationships among sponges are still largely unresolved. In the past 10 years, the classical taxonomy has been completely overturned and a review of the state of the art appears necessary. The field of taxonomy remains a prominent discipline of sponge research and studies related to sponge systematics were in greater number in the Eighth World Sponge Conference (Girona, Spain, September 2010) than in any previous world sponge conferences. To understand the state of this rapidly growing field, this chapter proposes to review studies, mainly from the past decade, in sponge taxonomy, nomenclature and phylogeny. In a first part, we analyse the reasons of the current success of this field. In a second part, we establish the current sponge systematics theoretical framework, with the use of (1) cladistics, (2) different codes of nomenclature (PhyloCode vs. Linnaean system) and (3) integrative taxonomy. Sponges are infamous for their lack of characters. However, by listing and discussing in a third part all characters available to taxonomists, we show how diverse characters are and that new ones are being used and tested, while old ones should be revisited. We then review the systematics of the four main classes of sponges (Hexactinellida, Calcispongiae, Homoscleromorpha and Demospongiae), each time focusing on current issues and case studies. We present a review of the taxonomic changes since the publication of the Systema Porifera (2002), and point to problems a sponge taxonomist is still faced with nowadays. To conclude, we make a series of proposals for the future of sponge systematics. In the light of recent studies, we establish a series of taxonomic changes that the sponge community may be ready to accept. We also propose a series of sponge new names and definitions following the PhyloCode. The issue of phantom species

  6. Analysis of sponge zones for computational fluid mechanics

    SciTech Connect

    Bodony, Daniel J. . E-mail: bodony@stanford.edu

    2006-03-01

    The use of sponge regions, or sponge zones, which add the forcing term -{sigma}(q - q {sub ref}) to the right-hand-side of the governing equations in computational fluid mechanics as an ad hoc boundary treatment is widespread. They are used to absorb and minimize reflections from computational boundaries and as forcing sponges to introduce prescribed disturbances into a calculation. A less common usage is as a means of extending a calculation from a smaller domain into a larger one, such as in computing the far-field sound generated in a localized region. By analogy to the penalty method of finite elements, the method is placed on a solid foundation, complete with estimates of convergence. The analysis generalizes the work of Israeli and Orszag [M. Israeli, S.A. Orszag, Approximation of radiation boundary conditions, J. Comp. Phys. 41 (1981) 115-135] and confirms their findings when applied as a special case to one-dimensional wave propagation in an absorbing sponge. It is found that the rate of convergence of the actual solution to the target solution, with an appropriate norm, is inversely proportional to the sponge strength. A detailed analysis for acoustic wave propagation in one-dimension verifies the convergence rate given by the general theory. The exponential point-wise convergence derived by Israeli and Orszag in the high-frequency limit is recovered and found to hold over all frequencies. A weakly nonlinear analysis of the method when applied to Burgers' equation shows similar convergence properties. Three numerical examples are given to confirm the analysis: the acoustic extension of a two-dimensional time-harmonic point source, the acoustic extension of a three-dimensional initial-value problem of a sound pulse, and the introduction of unstable eigenmodes from linear stability theory into a two-dimensional shear layer.

  7. Microbial diversity of marine sponges.

    PubMed

    Hentschel, U; Fieseler, L; Wehrl, M; Gernert, C; Steinert, M; Hacker, J; Horn, M

    2003-01-01

    The recent application of molecular microbial ecology tools to sponge-microbe associations has revealed a glimpse into the biodiversity of these microbial communities, that is considered just 'the tip of the iceberg'. This chapter provides an overview over these new findings with regard to identity, diversity and distribution patterns of sponge-associated microbial consortia. The sponges Aplysina aerophoba (Verongida), Rhopaloeides odorabile (Dicytoceratida) and Theonella swinhoei (Lithistida) were chosen as model systems for this review because they have been subject to both, cultivation-dependent and cultivation-independent approaches. A discussion of the microbial assemblages of Halichondriapanicea is presented in the accompanying chapter by Imhoff and Stöhr. Considering that a large fraction of sponge-associated microbes is not yet amenable to cultivation, an emphasis has been placed on the techniques centering around the 16S rRNA gene. A section has been included that covers the potential of sponge microbial communities for drug discovery. Finally, a 'sponge-microbe interaction model' is presented that summarizes our current understanding of the processes that might have shaped the community structure of the microbial assemblages within sponges. PMID:15825640

  8. Development of biomimetic tilapia collagen nanofibers for skin regeneration through inducing keratinocytes differentiation and collagen synthesis of dermal fibroblasts.

    PubMed

    Zhou, Tian; Wang, Nanping; Xue, Yang; Ding, Tingting; Liu, Xin; Mo, Xiumei; Sun, Jiao

    2015-02-11

    In this study, tilapia skin collagen sponge and electrospun nanofibers were developed for wound dressing. The collagen sponge was composed of at least two α-peptides, and its denaturation temperature was 44.99 °C. It did not change the number of spleen-derived lymphocytes in BALB/c mice, the ratio of CD4+/CD8+ lymphocytes, and the level of IgG or IgM in Sprague-Dawley rat. The contact angle, tensile strength, and weight loss temperature of collagen nanofibers were 21.2°, 6.72±0.44 MPa, and 300 °C, respectively. The nanofibers could promote the viabilities of human keratinocytes (HaCaTs) and human dermal fibroblasts (HDFs), inducing epidermal differentiation through the gene expression of involucrin, filaggrin, and type I transglutaminase of HaCaTs, and they could also accelerate migration of HaCaTs with the expression of matrix metalloproteinase-9 and transforming growth factor-β1 (TGF-β1). Besides, the nanofibers could upregulate the protien level of Col-I in HDFs both via a direct effect and TGF-β1 secreted from HaCaTs, thus facilitating the formation of collagen fibers. Furthermore, the collagen nanofibers stimulated the skin regeneration rapidly and effectively in vivo. These biological effects could be explained as the contributions from the biomimic extracellular cell matrix structure, hydrophilicity, and the multiple amino acids of the collagen nanofibers. PMID:25598076

  9. Determination of the Absolute Configuration of the Pseudo-Symmetric Natural Product Elatenyne by the Crystalline Sponge Method.

    PubMed

    Urban, Sylvia; Brkljača, Robert; Hoshino, Manabu; Lee, Shoukou; Fujita, Makoto

    2016-02-01

    Elatenyne is a marine natural product that was isolated in 1986. Despite its simple 2,2'-bifuranyl backbone, its relative structure was only recently determined. The absolute configuration of elatenyne has still not been unequivocally confirmed because of its pseudo-meso core structure, which results in a specific rotation, [α]D  , of almost zero. In this work, the structure of natural elatenyne was determined by the crystalline sponge method and the use of a porous coordination network (a crystalline sponge) capable of absorbing organic guests; in the sponge, the absorbed guests are ordered and crystallographically observable. The crystalline sponge could differentiate between the two very similar alkyl side chains, and the absolute structure of elatenyne was thus reliably determined. The total amount required for the experiments was only approximately 100 μg, and the majority (95 μg) could be recovered after the experiments. PMID:26880368

  10. Martian 'Kitchen Sponge'

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This picture is illuminated by sunlight from the upper left. It shows a tiny 1 kilometer by 1 kilometer (0.62 x 0.62 mile) area of the martian north polar residual ice cap as it appears in summertime.

    The surface looks somewhat like that of a kitchen sponge--it is flat on top and has many closely-spaced pits of no more than 2 meters (5.5 ft) depth. The upper, flat surface in this image has a medium-gray tone, while the pit interiors are darker gray. Each pit is generally 10 to 20 meters (33-66 feet) across. The pits probably form as water ice sublimes--going directly from solid to vapor--during the martian northern summer seasons. The pits probably develop over thousands of years. This texture is very different from what is seen in the south polar cap, where considerably larger and more circular depressions are found to resemble slices of swiss cheese rather than a kitchen sponge.

    This picture was taken by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) during northern summer on March 8, 1999. It was one of the very last 'calibration' images taken before the start of the Mapping Phase of the MGS mission, and its goal was to determine whether the MOC was properly focused. The crisp appearance of the edges of the pits confirmed that the instrument was focused and ready for its 1-Mars Year mapping mission. The scene is located near 86.9oN, 207.5oW, and has a resolution of about 1.4 meters (4 ft, 7 in) per pixel.

    Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.

  11. Heat Sponge: A Concept for Mass-Efficient Heat Storage

    NASA Technical Reports Server (NTRS)

    Splinter, Scott C.; Blosser, Max L.; Gifford, Andrew R.

    2008-01-01

    The heat sponge is a device for mass-efficient storage of heat. It was developed to be incorporated in the substructure of a re-entry vehicle to reduce thermal- protection-system requirements. The heat sponge consists of a liquid/vapor mixture contained within a number of miniature pressure vessels that can be embedded within a variety of different types of structures. As temperature is increased, pressure in the miniature pressure vessels also increases so that heat absorbed through vaporization of the liquid is spread over a relatively large temperature range. Using water as a working fluid, the heat-storage capacity of the liquid/vapor mixture is many times higher than that of typical structural materials and is well above that of common phase change materials over a temperature range of 200 F to 700 F. The use of pure ammonia as the working fluid provides a range of application between 432 deg R and 730 deg R, or the use of the more practical water-ammonia solution provides a range of application between 432 deg R and 1160 deg R or in between that of water and pure ammonia. Prototype heat sponges were fabricated and characterized. These heat sponges consisted of 1.0-inch-diameter, hollow, stainless-steel spheres with a wall thickness of 0.020 inches which had varying percentages of their interior volumes filled with water and a water-ammonia solution. An apparatus to measure the heat stored in these prototype heat sponges was designed, fabricated, and verified. The heat-storage capacity calculated from measured temperature histories is compared to numerical predictions.

  12. Effect of sterilization on contaminated sponges.

    PubMed

    Kuritani, R H; McDonald, N J; Sydiskis, R J

    1993-02-01

    Sponges are routinely used as a storage medium for endodontic files during clinical practice; however, very little research has been done to determine the effectiveness of sterilization procedures for these contaminated sponges. The purpose of this in vitro study was to determine the efficacy of chemical vapor sterilizers (chemiclaves), steam pressure sterilizers (autoclaves), and dry heat sterilizers on laboratory contaminated sponges. Four different types of sponges were used in this study: a black, relatively nonporous sponge; a red, semiporous stationary sponge; a blue, endodontic sponge, and a yellow, common household sponge. Natural sponges were eliminated from the study, because their large pore size made them unsuitable as a storage medium for endodontic instruments. The sponges were divided into three groups: chemiclave, autoclave, and dry heat. Five samples of each sponge type were impregnated with biological indicating strips containing spores of Bacillus stearothermophilus. Each sponge was subjected to 25 cycles of sterilization. The spore strip indicator was inserted into the sponges at 1, 5, 10, 15, 20, and 25 cycles. The spore strip was cultivated in trypticase soy broth medium solution at 55 +/- 1 degree C for 7 days. At 7 days the culture vials were read for turbidity; its presence indicating a positive culture. The samples that were subjected to chemiclaving demonstrated positive cultures of 0.00%, 0.00%, and 30.00% and those to autoclaving 3.33%, 0.00%, and 0.00% positive cultures for the black, red, and blue sponge types, respectively. None of the sponges survived dry heat sterilization. The O-Cell-O sponges become unusable when subjected to all of the sterilization methods used in this study. PMID:8509738

  13. DEMONSTRATION BULLETIN: FORAGER™ SPONGE TECHNOLOGY - DYNAPHORE, INC.

    EPA Science Inventory

    The Forager™ Sponge is an open-celled cellulose sponge incorporating an amine-containing chelating polymer that has selective affinity for dissolved heavy metals in both cationic and anionic states. The Forager™ Sponge technology can be utilized to remove and concentrate heavy me...

  14. Effective disinfection methods of kitchen sponges

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pathogenic foodborne bacteria can be disseminated in households through the use of contaminated sponges. Several household disinfecting treatments to kill bacteria, yeasts and molds on sponges were evaluated. Sponges were incubated in a suspension of ground beef and tryptic soy broth to develop bact...

  15. Advances in the production of sponge biomass Aplysina aerophoba--a model sponge for ex situ sponge biomass production.

    PubMed

    Hausmann, Rudolf; Vitello, Marco P; Leitermann, Frank; Syldatk, Christoph

    2006-06-25

    Sponges are a promising source of organic compounds of potential interest regarding industrial and medical applications. For detailed studies on such compounds, large amounts of sponge biomass are required. Obtaining that is at present extremely difficult because most sponges are relatively rare in nature and their mass cultivation in the laboratory has not yet been accomplished. In this study the possibility of culturing Aplysina aerophoba fragments in laboratory was examined. While a substantial biomass increase was not yet observed, we achieved fragmented sponge tissue to develop into a functional sponge as a first success. PMID:16697067

  16. Mimivirus Collagen Is Modified by Bifunctional Lysyl Hydroxylase and Glycosyltransferase Enzyme*

    PubMed Central

    Luther, Kelvin B.; Hülsmeier, Andreas J.; Schegg, Belinda; Deuber, Stefan A.; Raoult, Didier; Hennet, Thierry

    2011-01-01

    Collagens, the most abundant proteins in animals, are modified by hydroxylation of proline and lysine residues and by glycosylation of hydroxylysine. Dedicated prolyl hydroxylase, lysyl hydroxylase, and collagen glycosyltransferase enzymes localized in the endoplasmic reticulum mediate these modifications prior to the formation of the collagen triple helix. Whereas collagen-like proteins have been described in some fungi, bacteria, and viruses, the post-translational machinery modifying collagens has never been described outside of animals. We demonstrate that the L230 open reading frame of the giant virus Acanthamoeba polyphaga mimivirus encodes an enzyme that has distinct lysyl hydroxylase and collagen glycosyltransferase domains. We show that mimivirus L230 is capable of hydroxylating lysine and glycosylating the resulting hydroxylysine residues in a native mimivirus collagen acceptor substrate. Whereas in animals from sponges to humans the transfer of galactose to hydroxylysine in collagen is conserved, the mimivirus L230 enzyme transfers glucose to hydroxylysine, thereby defining a novel type of collagen glycosylation in nature. The presence of hydroxylysine in mimivirus proteins was confirmed by amino acid analysis of mimivirus recovered from A. polyphaga cultures. This work shows for the first time that collagen post-translational modifications are not confined to the domains of life. The utilization of glucose instead of the galactose found throughout animals as well as a bifunctional enzyme rather than two separate enzymes may represent a parallel evolutionary track in collagen biology. These results suggest that giant viruses may have contributed to the evolution of collagen biology. PMID:22045808

  17. Bone healing capabilities of recombinant human bone morphogenetic protein-9 (rhBMP-9) with a chitosan or collagen carrier in rat calvarial defects.

    PubMed

    Shinohara, Yukiya; Nakamura, Toshiaki; Shirakata, Yoshinori; Noguchi, Kazuyuki

    2016-01-01

    The aim of this study was to examine the effects of recombinant human BMP-9 (rhBMP-9) with chitosan sponge (ChiS) or absorbable collagen sponge (ACS) on bone formation in rat calvarial defects. The defects were treated by one of the following implantations: ChiS, rhBMP-9/ChiS, ACS, rhBMP-9/ACS and no implantation. The animals were euthanized at 8 weeks for histological evaluation. The percentage of defect closure (DC) in the rhBMP-9/ACS group was significantly greater than that in the ACS group. The rhBMP-9/ACS group demonstrated the highest level of DC among all the groups. The newly formed bone area (NBA) and NBA/total area in the ChiS-implanted groups and in the rhBMP-9/ACS group were significantly greater compared with those in the ACS group. It can be concluded that rhBMP-9/ACS has a potential to induce bone formation in rat calvarial defects. Further studies are required to elucidate the mechanism of bone formation induced by rhBMP-9. PMID:27252002

  18. Precambrian sponges with cellular structures

    PubMed

    Li; Chen; Hua

    1998-02-01

    Sponge remains have been identified in the Early Vendian Doushantuo phosphate deposit in central Guizhou (South China), which has an age of approximately 580 million years ago. Their skeletons consist of siliceous, monaxonal spicules. All are referred to as the Porifera, class Demospongiae. Preserved soft tissues include the epidermis, porocytes, amoebocytes, sclerocytes, and spongocoel. Among thousands of metazoan embryos is a parenchymella-type of sponge larvae having a shoe-shaped morphology and dense peripheral flagella. The presence of possible amphiblastula larva suggests that the calcareous sponges may have an extended history in the Late Precambrian. The fauna indicates that animals lived 40 to 50 million years before the Cambrian Explosion. PMID:9452391

  19. NIR-triggered drug delivery by collagen-mediated second harmonic generation.

    PubMed

    Barhoumi, Aoune; Salvador-Culla, Borja; Kohane, Daniel S

    2015-06-01

    Second harmonic generation is a process through which nonlinear materials such as collagen can absorb two photons and scatter one with twice the energy. Collagen upconverts 730 nm (near-IR) to 365 nm (UV) through second harmonic generation, which cleaves a molecule bound to collagen via a UV-sensitive linker. PMID:25728310

  20. The systematics of carnivorous sponges.

    PubMed

    Hestetun, Jon Thomassen; Vacelet, Jean; Boury-Esnault, Nicole; Borchiellini, Carole; Kelly, Michelle; Ríos, Pilar; Cristobo, Javier; Rapp, Hans Tore

    2016-01-01

    Carnivorous sponges are characterized by their unique method of capturing mesoplanktonic prey coupled with the complete or partial reduction of the aquiferous system characteristic of the phylum Porifera. Current systematics place the vast majority of carnivorous sponges within Cladorhizidae, with certain species assigned to Guitarridae and Esperiopsidae. Morphological characters have not been able to show whether this classification is evolutionary accurate, and whether carnivory has evolved once or in several lineages. In the present paper we present the first comprehensive molecular phylogeny of the carnivorous sponges, interpret these results in conjunction with morphological characters, and propose a revised classification of the group. Molecular phylogenies were inferred using 18S rDNA and a combined dataset of partial 28S rDNA, COI and ALG11 sequences. The results recovered carnivorous sponges as a clade closely related to the families Mycalidae and Guitarridae, showing family Cladorhizidae to be monophyletic and also including carnivorous species currently placed in other families. The genus Lycopodina is resurrected for species currently placed in the paraphyletic subgenus Asbestopluma (Asbestopluma) featuring forceps spicules and lacking sigmas or sigmancistras. The genera Chondrocladia and Cladorhiza are found to be monophyletic. However, results indicate that the subgenus Chondrocladia is polyphyletic with respect to the subgenera Meliiderma and Symmetrocladia. Euchelipluma, formerly Guitarridae, is retained, but transferred to Cladorhizidae. The four known carnivorous species currently in Esperiopsis are transferred to Abyssocladia. Neocladia is a junior homonym and is here renamed Koltunicladia. Our results provide strong evidence in support of the hypothesis that carnivory in sponges has evolved only once. While spicule characters mostly reflect monophyletic groups at the generic level, differences between genera represent evolution within family

  1. Formation of multimers of bacterial collagens through introduction of specific sites for oxidative crosslinking.

    PubMed

    Stoichevska, Violet; An, Bo; Peng, Yong Y; Yigit, Sezin; Vashi, Aditya V; Kaplan, David L; Werkmeister, Jerome A; Dumsday, Geoff J; Ramshaw, John A M

    2016-09-01

    A range of non-animal collagens has been described, derived from bacterial species, which form stable triple-helical structures without the need for secondary modification to include hydroxyproline in the sequence. The non-animal collagens studied to date are typically smaller than animal interstitial collagens, around one quarter the length and do not pack into large fibrillar aggregates like those that are formed by the major animal interstitial collagens. A consequence of this for biomedical products is that fabricated items, such as collagen sponges, are not as mechanically and dimensionally stable as those of animal collagens. In the present study, we examined the production of larger, polymeric forms of non-animal collagens through introduction of tyrosine and cysteine residues that can form selective crosslinks through oxidation. These modifications allow the formation of larger aggregates of the non-animal collagens. When Tyr residues were incorporated, gels were obtained. And with Cys soluble aggregates were formed. These materials can be formed into sponges that are more stable than those formed without these modifications. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2369-2376, 2016. PMID:27171817

  2. Embroidered polymer-collagen hybrid scaffold variants for ligament tissue engineering.

    PubMed

    Hoyer, M; Drechsel, N; Meyer, M; Meier, C; Hinüber, C; Breier, A; Hahner, J; Heinrich, G; Rentsch, C; Garbe, L-A; Ertel, W; Schulze-Tanzil, G; Lohan, A

    2014-10-01

    Embroidery techniques and patterns used for scaffold production allow the adaption of biomechanical scaffold properties. The integration of collagen into embroidered polylactide-co-caprolactone [P(LA-CL)] and polydioxanone (PDS) scaffolds could stimulate neo-tissue formation by anterior cruciate ligament (ACL) cells. Therefore, the aim of this study was to test embroidered P(LA-CL) and PDS scaffolds as hybrid scaffolds in combination with collagen hydrogel, sponge or foam for ligament tissue engineering. ACL cells were cultured on embroidered P(LA-CL) and PDS scaffolds without or with collagen supplementation. Cell adherence, vitality, morphology and ECM synthesis were analyzed. Irrespective of thread size, ACL cells seeded on P(LA-CL) scaffolds without collagen adhered and spread over the threads, whereas the cells formed clusters on PDS and larger areas remained cell-free. Using the collagen hydrogel, the scaffold colonization was limited by the gel instability. The collagen sponge layers integrated into the scaffolds were hardly penetrated by the cells. Collagen foams increased scaffold colonization in P(LA-CL) but did not facilitate direct cell-thread contacts in the PDS scaffolds. The results suggest embroidered P(LA-CL) scaffolds as a more promising basis for tissue engineering an ACL substitute than PDS due to superior cell attachment. Supplementation with a collagen foam presents a promising functionalization strategy. PMID:25175216

  3. Bacteria associated with an encrusting sponge (Terpios hoshinota) and the corals partially covered by the sponge.

    PubMed

    Tang, Sen-Lin; Hong, Mei-Jhu; Liao, Ming-Hui; Jane, Wann-Neng; Chiang, Pei-Wen; Chen, Chung-Bin; Chen, Chaolun A

    2011-05-01

    Terpios hoshinota, a dark encrusting sponge, is known to be a competitor for space in coral reef environments, and facilitates the death of corals. Although numerous cyanobacteria have been detected in the sponge, little is known of the sponge-associated bacterial community. This study examined the sponge-associated bacterial community and the difference between the bacterial communities in the sponge and the coral partially covered by the sponge by analysis of 16S rRNA gene sequences of samples isolated from the sponge covering the corals Favia complanata, Isopora palifera, Millepora sp., Montipora efflorescens and Porites lutea. The sponge-associated bacterial community was mainly (61-98%) composed of cyanobacteria, with approximately 15% of these alphaproteobacteria and gammaproteobacteria, although the proportions varied in different sponge samples. The dominant cyanobacteria group was an isolated group closely related to Prochloron sp. The comparison of the bacterial communities isolated from sponge-free and the sponge-covered P. lutea showed that covering by the sponge caused changes in the coral-associated bacterial communities, with the presence of bacteria similar to those detected in black-band disease, suggesting the sponge might benefit from the presence of bacteria associated with unhealthy coral, particularly in the parts of the coral closest to the margin of the sponge. PMID:21265978

  4. Sound Absorbers

    NASA Astrophysics Data System (ADS)

    Fuchs, H. V.; Möser, M.

    Sound absorption indicates the transformation of sound energy into heat. It is, for instance, employed to design the acoustics in rooms. The noise emitted by machinery and plants shall be reduced before arriving at a workplace; auditoria such as lecture rooms or concert halls require a certain reverberation time. Such design goals are realised by installing absorbing components at the walls with well-defined absorption characteristics, which are adjusted for corresponding demands. Sound absorbers also play an important role in acoustic capsules, ducts and screens to avoid sound immission from noise intensive environments into the neighbourhood.

  5. Characterization Of Sponge-Associated Microbial Communities

    NASA Astrophysics Data System (ADS)

    Bailey, K. L.; Weisz, J.; Lindquist, N.

    2004-12-01

    To more fully understand the endosymbiotic relationship between sponges and microorganisms, it is necessary to characterize the microbial communities of the sponges. In this study, DNA was extracted from each of three individual sponges from four sponge species collected in a shallow mangrove cut in Florida Bay near Key Largo, Florida. A fragment of the 16S rRNA gene from sponge-associated bacteria was amplified using the polymerase chain reaction (PCR). The resulting PCR products were analyzed by denaturing gradient gel electrophoresis (DGGE), which separates DNA fragments based on their sequence differences. Some 16S sequences appeared to be shared by each of the four sponge species, while other fragments found in only particular species likely represent unique bacterial strains that play a role in sponge nutrition.

  6. Study of rheological, viscoelastic and vulcanization behavior of sponge EPDM/NR blended nano- composites

    NASA Astrophysics Data System (ADS)

    Arshad Bashir, M.; Shahid, M.; Ahmed, Riaz; Yahya, A. G.

    2014-06-01

    In this research paper the effect of blending ratio of natural rubber (NR) with Ethylene Propylene Diene Monomer (EPDM) were investigated. Different samples of EPDM/NR ratio were prepared to study the variation of NR in EPDM on rheology, curing characteristics, tangent δ, and viscosity variation during vulcanization of sponge nano composites.The main aim of present research is to develop elastomeric based sponge composites with the blending ratio of base elastomers along with the carbon nano particles for high energy absorbing and damping applications. The curing characteristics, rheology and viscoelastic nature of the composite is remarkably influenced with the progressive blending ratio of the base elastomeric matrix.

  7. Sputter Deposition of Metallic Sponges

    SciTech Connect

    Jankowski, A F; Hayes, J P

    2002-01-18

    Metallic films are grown with a sponge-like morphology in the as-deposited condition using planar magnetron sputtering. The morphology of the deposit is characterized by metallic continuity in three dimensions with continuous porosity on the sub-micron scale. The stabilization of the metallic sponge is directly correlated with a limited range for the sputter deposition parameters of working gas pressure and substrate temperature. This sponge-like morphology augments the features as generally understood in the classic zone models of growth for physical vapor deposits. Nickel coatings are deposited with working gas pressures up to 4 Pa and for substrate temperatures up to 1100 K. The morphology of the deposits is examined in plan and in cross-section with scanning electron microscopy. The parametric range of gas pressure and substrate temperature (relative to absolute melt point) for the deposition processing under which the metallic sponges are produced appear universal for many metals, as for example, including gold, silver, and aluminum.

  8. Why do dolphins carry sponges?

    PubMed

    Mann, Janet; Sargeant, Brooke L; Watson-Capps, Jana J; Gibson, Quincy A; Heithaus, Michael R; Connor, Richard C; Patterson, Eric

    2008-01-01

    Tool use is rare in wild animals, but of widespread interest because of its relationship to animal cognition, social learning and culture. Despite such attention, quantifying the costs and benefits of tool use has been difficult, largely because if tool use occurs, all population members typically exhibit the behavior. In Shark Bay, Australia, only a subset of the bottlenose dolphin population uses marine sponges as tools, providing an opportunity to assess both proximate and ultimate costs and benefits and document patterns of transmission. We compared sponge-carrying (sponger) females to non-sponge-carrying (non-sponger) females and show that spongers were more solitary, spent more time in deep water channel habitats, dived for longer durations, and devoted more time to foraging than non-spongers; and, even with these potential proximate costs, calving success of sponger females was not significantly different from non-spongers. We also show a clear female-bias in the ontogeny of sponging. With a solitary lifestyle, specialization, and high foraging demands, spongers used tools more than any non-human animal. We suggest that the ecological, social, and developmental mechanisms involved likely (1) help explain the high intrapopulation variation in female behaviour, (2) indicate tradeoffs (e.g., time allocation) between ecological and social factors and, (3) constrain the spread of this innovation to primarily vertical transmission. PMID:19066625

  9. The Collagen Family

    PubMed Central

    Ricard-Blum, Sylvie

    2011-01-01

    Collagens are the most abundant proteins in mammals. The collagen family comprises 28 members that contain at least one triple-helical domain. Collagens are deposited in the extracellular matrix where most of them form supramolecular assemblies. Four collagens are type II membrane proteins that also exist in a soluble form released from the cell surface by shedding. Collagens play structural roles and contribute to mechanical properties, organization, and shape of tissues. They interact with cells via several receptor families and regulate their proliferation, migration, and differentiation. Some collagens have a restricted tissue distribution and hence specific biological functions. PMID:21421911

  10. Global Diversity of Sponges (Porifera)

    PubMed Central

    Van Soest, Rob W. M.; Boury-Esnault, Nicole; Vacelet, Jean; Dohrmann, Martin; Erpenbeck, Dirk; De Voogd, Nicole J.; Santodomingo, Nadiezhda; Vanhoorne, Bart; Kelly, Michelle; Hooper, John N. A.

    2012-01-01

    With the completion of a single unified classification, the Systema Porifera (SP) and subsequent development of an online species database, the World Porifera Database (WPD), we are now equipped to provide a first comprehensive picture of the global biodiversity of the Porifera. An introductory overview of the four classes of the Porifera is followed by a description of the structure of our main source of data for this paper, the WPD. From this we extracted numbers of all ‘known’ sponges to date: the number of valid Recent sponges is established at 8,553, with the vast majority, 83%, belonging to the class Demospongiae. We also mapped for the first time the species richness of a comprehensive set of marine ecoregions of the world, data also extracted from the WPD. Perhaps not surprisingly, these distributions appear to show a strong bias towards collection and taxonomy efforts. Only when species richness is accumulated into large marine realms does a pattern emerge that is also recognized in many other marine animal groups: high numbers in tropical regions, lesser numbers in the colder parts of the world oceans. Preliminary similarity analysis of a matrix of species and marine ecoregions extracted from the WPD failed to yield a consistent hierarchical pattern of ecoregions into marine provinces. Global sponge diversity information is mostly generated in regional projects and resources: results obtained demonstrate that regional approaches to analytical biogeography are at present more likely to achieve insights into the biogeographic history of sponges than a global perspective, which appears currently too ambitious. We also review information on invasive sponges that might well have some influence on distribution patterns of the future. PMID:22558119

  11. Global diversity of sponges (Porifera).

    PubMed

    Van Soest, Rob W M; Boury-Esnault, Nicole; Vacelet, Jean; Dohrmann, Martin; Erpenbeck, Dirk; De Voogd, Nicole J; Santodomingo, Nadiezhda; Vanhoorne, Bart; Kelly, Michelle; Hooper, John N A

    2012-01-01

    With the completion of a single unified classification, the Systema Porifera (SP) and subsequent development of an online species database, the World Porifera Database (WPD), we are now equipped to provide a first comprehensive picture of the global biodiversity of the Porifera. An introductory overview of the four classes of the Porifera is followed by a description of the structure of our main source of data for this paper, the WPD. From this we extracted numbers of all 'known' sponges to date: the number of valid Recent sponges is established at 8,553, with the vast majority, 83%, belonging to the class Demospongiae. We also mapped for the first time the species richness of a comprehensive set of marine ecoregions of the world, data also extracted from the WPD. Perhaps not surprisingly, these distributions appear to show a strong bias towards collection and taxonomy efforts. Only when species richness is accumulated into large marine realms does a pattern emerge that is also recognized in many other marine animal groups: high numbers in tropical regions, lesser numbers in the colder parts of the world oceans. Preliminary similarity analysis of a matrix of species and marine ecoregions extracted from the WPD failed to yield a consistent hierarchical pattern of ecoregions into marine provinces. Global sponge diversity information is mostly generated in regional projects and resources: results obtained demonstrate that regional approaches to analytical biogeography are at present more likely to achieve insights into the biogeographic history of sponges than a global perspective, which appears currently too ambitious. We also review information on invasive sponges that might well have some influence on distribution patterns of the future. PMID:22558119

  12. Collagen vascular disease

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/001223.htm Collagen vascular disease To use the sharing features on ... were previously said to have "connective tissue" or "collagen vascular" disease. We now have names for many ...

  13. Electrospun tilapia collagen nanofibers accelerating wound healing via inducing keratinocytes proliferation and differentiation.

    PubMed

    Zhou, Tian; Wang, Nanping; Xue, Yang; Ding, Tingting; Liu, Xin; Mo, Xiumei; Sun, Jiao

    2016-07-01

    The development of biomaterials with the ability to induce skin wound healing is a great challenge in biomedicine. In this study, tilapia skin collagen sponge and electrospun nanofibers were developed for wound dressing. The collagen sponge was composed of at least two α-peptides. It did not change the number of spleen-derived lymphocytes in BALB/c mice, the ratio of CD4(+)/CD8(+) lymphocytes, and the level of IgG or IgM in Sprague-Dawley rats. The tensile strength and contact angle of collagen nanofibers were 6.72±0.44MPa and 26.71±4.88°, respectively. They also had good thermal stability and swelling property. Furthermore, the nanofibers could significantly promote the proliferation of human keratinocytes (HaCaTs) and stimulate epidermal differentiation through the up-regulated gene expression of involucrin, filaggrin, and type I transglutaminase in HaCaTs. The collagen nanofibers could also facilitate rat skin regeneration. In the present study, electrospun biomimetic tilapia skin collagen nanofibers were succesfully prepared, were proved to have good bioactivity and could accelerate rat wound healing rapidly and effectively. These biological effects might be attributed to the biomimic extracellular matrix structure and the multiple amino acids of the collagen nanofibers. Therefore, the cost-efficient tilapia collagen nanofibers could be used as novel wound dressing, meanwhile effectively avoiding the risk of transmitting animal disease in the future clinical apllication. PMID:27037778

  14. Chitosan-aluminum monostearate composite sponge dressing containing asiaticoside for wound healing and angiogenesis promotion in chronic wound.

    PubMed

    Phaechamud, Thawatchai; Yodkhum, Kotchamon; Charoenteeraboon, Juree; Tabata, Yasuhiko

    2015-05-01

    There are many factors that delay healing in chronic wounds including lowering level of growth factors and increasing exudate level comprising high amount of tissue destructive enzymes. Asiaticoside possesses interesting wound healing and angiogenic activities that are employed to stimulate tissue regeneration in wound healing application. This study attempted to develop chitosan-aluminum monostearate (Alst) composite sponge containing asiaticoside for use as an absorbent medical dressing in chronic wound. N-methyl-2-pyrrolidone (NMP) was used to enhance homogeneity of asiaticoside in the polymer composite matrix. The sponge dressings were prepared by lyophilization and dehydrothermal treatment (DHT). Functional group interaction, crystallinity, and morphology of the prepared sponges were investigated using FT-IR, PXRD, and SEM, respectively. Physicochemical properties, porosity, hydrophilic/hydrophobic properties and mechanical property, were evaluated. Wound dressing properties, water vapor transmission rate (WVTR), fluid absorbency, oxygen permeation (OP), and bio-adhesive property, were investigated. In vitro asiaticoside release study was conducted using immersion method. Cytotoxicity was studied in normal human dermal fibroblast (NHDF) and normal human epidermal keratinocyte (NHEK). Angiogenic activity of asiaticoside was evaluated using chick-chorioallantoic membrane (CAM) assay. FT-IR and PXRD results revealed the amidation after DHT to enhance the crystallinity of the prepared sponges. The prepared sponges had high porosity comprising high Alst-loaded amount that exhibited more compact structure. Alst enhanced hydrophobicity therefore it reduced the fluid absorption and WVTR together with bio-adhesion of the prepared sponge dressings. Porosity of all sponges was more than 85% therefore resulting in their high OP. Enhancing hydrophobicity of the material by Alst and more homogeneity caused by NMP eventually retarded the asiaticoside release for 7 days. The

  15. Isolation, Characterization and Biological Evaluation of Jellyfish Collagen for Use in Biomedical Applications

    PubMed Central

    Addad, Sourour; Exposito, Jean-Yves; Faye, Clément; Ricard-Blum, Sylvie; Lethias, Claire

    2011-01-01

    Fibrillar collagens are the more abundant extracellular proteins. They form a metazoan-specific family, and are highly conserved from sponge to human. Their structural and physiological properties have been successfully used in the food, cosmetic, and pharmaceutical industries. On the other hand, the increase of jellyfish has led us to consider this marine animal as a natural product for food and medicine. Here, we have tested different Mediterranean jellyfish species in order to investigate the economic potential of their collagens. We have studied different methods of collagen purification (tissues and experimental procedures). The best collagen yield was obtained using Rhizostoma pulmo oral arms and the pepsin extraction method (2–10 mg collagen/g of wet tissue). Although a significant yield was obtained with Cotylorhiza tuberculata (0.45 mg/g), R. pulmo was used for further experiments, this jellyfish being considered as harmless to humans and being an abundant source of material. Then, we compared the biological properties of R. pulmo collagen with mammalian fibrillar collagens in cell cytotoxicity assays and cell adhesion. There was no statistical difference in cytotoxicity (p > 0.05) between R. pulmo collagen and rat type I collagen. However, since heparin inhibits cell adhesion to jellyfish-native collagen by 55%, the main difference is that heparan sulfate proteoglycans could be preferentially involved in fibroblast and osteoblast adhesion to jellyfish collagens. Our data confirm the broad harmlessness of jellyfish collagens, and their biological effect on human cells that are similar to that of mammalian type I collagen. Given the bioavailability of jellyfish collagen and its biological properties, this marine material is thus a good candidate for replacing bovine or human collagens in selected biomedical applications. PMID:21747742

  16. Use of gentamicin sulfate-impregnated sponges as adjuvant therapy for the treatment of chronic foreign body associated sternal osteomyelitis in a dog

    PubMed Central

    Wainberg, Shannon H.; Brisson, Brigitte A.; Hayes, Galina M.; Mackenzie, Shawn

    2015-01-01

    A 2-year-old Labrador retriever dog was referred for evaluation of parasternal chronic draining sinus tracts associated with sternal osteomyelitis secondary to the presence of a residual wooden foreign body. The use of gentamicin-impregnated collagen sponges as adjunctive therapy to osteomyelitis treatment is reported herein. PMID:26538672

  17. Biomimetic collagen scaffolds with anisotropic pore architecture.

    PubMed

    Davidenko, N; Gibb, T; Schuster, C; Best, S M; Campbell, J J; Watson, C J; Cameron, R E

    2012-02-01

    Sponge-like matrices with a specific three-dimensional structural design resembling the actual extracellular matrix of a particular tissue show significant potential for the regeneration and repair of a broad range of damaged anisotropic tissues. The manipulation of the structure of collagen scaffolds using a freeze-drying technique was explored in this work as an intrinsically biocompatible way of tailoring the inner architecture of the scaffold. The research focused on the influence of temperature gradients, imposed during the phase of crystallisation of collagen suspensions, upon the degree of anisotropy in the microstructures of the scaffolds produced. Moulding technology was employed to achieve differences in heat transfer rates during the freezing processes. For this purpose various moulds with different configurations were developed with a view to producing uniaxial and multi-directional temperature gradients across the sample during this process. Scanning electron microscopy analysis of different cross-sections (longitudinal and horizontal) of scaffolds revealed that highly aligned matrices with axially directed pore architectures were obtained where single unidirectional temperature gradients were induced. Altering the freezing conditions by the introduction of multiple temperature gradients allowed collagen scaffolds to be produced with complex pore orientations, and anisotropy in pore size and alignment. PMID:22005330

  18. Who Produces Ianthelline? The Arctic Sponge Stryphnus fortis or its Sponge Epibiont Hexadella dedritifera: a Probable Case of Sponge-Sponge Contamination.

    PubMed

    Cárdenas, Paco

    2016-04-01

    The bromotyrosine derivative ianthelline was isolated recently from the Atlantic boreo-arctic deep-sea sponge Stryphnus fortis, and shown to have clear antitumor and antifouling effects. However, chemosystematics, field observations, and targeted metabolic analyses (using UPLC-MS) suggest that ianthelline is not produced by S. fortis but by Hexadella dedritifera, a sponge that commonly grows on S. fortis. This case highlights the importance of combining taxonomic and ecological knowledge to the field of sponge natural products research. PMID:27091193

  19. SITE demonstration of the Dynaphore/Forager Sponge technology to remove dissolved metals from contaminated groundwater

    SciTech Connect

    Esposito, C.R.; Vaccaro, G.

    1995-10-01

    A Superfund Innovative Technology Evaluation (SITE) demonstration was conducted of the Dynaphore/Forager Sponge technology during the week of April 3, 1994 at the N.L. Industries Superfund Site in Pedricktown, New Jersey. The Forager Sponge is an open-celled cellulose sponge incorporating an amine-containing chelating polymer that selectively absorbs dissolved heavy metals in both cationic and anionic states. This technology is a volume reduction technology in which heavy metal contaminants from an aqueous medium are concentrated into a smaller volume for facilitated disposal. The developer states that the technology can be used to remove heavy metals from a wide variety of aqueous media, such as groundwater, surface waters and process waters. The sponge matrix can be directly disposed, or regenerated with chemical solutions. For this demonstration the sponge was set up as a mobile pump-and-treat system which treated groundwater contaminated with heavy metals. The demonstration focused on the system`s ability to remove lead, cadmium, chromium and copper from the contaminated groundwater over a continuous 72-hour test. The removal of heavy metals proceeded in the presence of significantly higher concentrations of innocuous cations such as calcium, magnesium, sodium, potassium and aluminum.

  20. UV-responsive nano-sponge for oil absorption and desorption

    NASA Astrophysics Data System (ADS)

    Kim, Do Hyun; Jung, Min Chan; Cho, So-Hye; Kim, Sang Hoon; Kim, Ho-Young; Lee, Heon Ju; Oh, Kyu Hwan; Moon, Myoung-Woon

    2015-08-01

    Controlled surface wettability for oil has been intensively studied to remove industrial oil waste or oil spill pollution from seas or rivers. In particular, external stimuli-induced special wetting materials, such as photo-responsive TiO2, have attracted considerable attention for oil-water separation. In this study, a novel method is reported to fabricate a nano-sponge which is composed of hydrophobic hydrocarbon and hydrophilic TiO2 nanoparticles for oil absorption or desorption that are responsive to UV irradiation. The hydrocarbon in the nano-sponge could selectively absorb oil from water, whereas the absorbed oil is released into the water by TiO2 in response to UV irradiation. The nano-sponge functionalized porous polydimethylsiloxane released more than 98% of the absorbed crude oil with UV irradiation and air-bubbling. It could be continuously reused while maintaining a high absorption capacity and desorption efficiency without incurring secondary air or water pollution. This smart oil absorption/desorption methodology with excellent selectivity and recyclability with almost perfect removal of absorbed oil can be applied for oil-water separation, oil spill cleanup and reuse of spilled oil.

  1. UV-responsive nano-sponge for oil absorption and desorption

    PubMed Central

    Kim, Do Hyun; Jung, Min Chan; Cho, So-Hye; Kim, Sang Hoon; Kim, Ho-Young; Lee, Heon Ju; Oh, Kyu Hwan; Moon, Myoung-Woon

    2015-01-01

    Controlled surface wettability for oil has been intensively studied to remove industrial oil waste or oil spill pollution from seas or rivers. In particular, external stimuli-induced special wetting materials, such as photo-responsive TiO2, have attracted considerable attention for oil-water separation. In this study, a novel method is reported to fabricate a nano-sponge which is composed of hydrophobic hydrocarbon and hydrophilic TiO2 nanoparticles for oil absorption or desorption that are responsive to UV irradiation. The hydrocarbon in the nano-sponge could selectively absorb oil from water, whereas the absorbed oil is released into the water by TiO2 in response to UV irradiation. The nano-sponge functionalized porous polydimethylsiloxane released more than 98% of the absorbed crude oil with UV irradiation and air-bubbling. It could be continuously reused while maintaining a high absorption capacity and desorption efficiency without incurring secondary air or water pollution. This smart oil absorption/desorption methodology with excellent selectivity and recyclability with almost perfect removal of absorbed oil can be applied for oil-water separation, oil spill cleanup and reuse of spilled oil. PMID:26260470

  2. COLLAGEN STRUCTURE AND STABILITY

    PubMed Central

    Shoulders, Matthew D.; Raines, Ronald T.

    2010-01-01

    Collagen is the most abundant protein in animals. This fibrous, structural protein comprises a right-handed bundle of three parallel, left-handed polyproline II-type helices. Much progress has been made in elucidating the structure of collagen triple helices and the physicochemical basis for their stability. New evidence demonstrates that stereoelectronic effects and preorganization play a key role in that stability. The fibrillar structure of type I collagen–the prototypical collagen fibril–has been revealed in detail. Artificial collagen fibrils that display some properties of natural collagen fibrils are now accessible using chemical synthesis and self-assembly. A rapidly emerging understanding of the mechanical and structural properties of native collagen fibrils will guide further development of artificial collagenous materials for biomedicine and nanotechnology. PMID:19344236

  3. Metal sponge for cryosorption pumping applications

    DOEpatents

    Myneni, Ganapati R.; Kneisel, Peter

    1995-01-01

    A system has been developed for adsorbing gases at high vacuum in a closed area. The system utilizes large surface clean anodized metal surfaces at low temperatures to adsorb the gases. The large surface clean anodized metal is referred to as a metal sponge. The metal sponge generates or maintains the high vacuum by increasing the available active cryosorbing surface area.

  4. Metal sponge for cryosorption pumping applications

    DOEpatents

    Myneni, G.R.; Kneisel, P.

    1995-12-26

    A system has been developed for adsorbing gases at high vacuum in a closed area. The system utilizes large surface clean anodized metal surfaces at low temperatures to adsorb the gases. The large surface clean anodized metal is referred to as a metal sponge. The metal sponge generates or maintains the high vacuum by increasing the available active cryosorbing surface area. 4 figs.

  5. Effective household disinfection methods of kitchen sponges

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Several household disinfecting treatments to kill bacteria, yeasts and molds on kitchen sponges were evaluated. Sponges were soaked in 10 percent bleach for 3 min, lemon juice (pH 2.9) or deionized water for 1 min; placed in a microwave oven for 1 min; or placed in a dishwasher operating with a dryi...

  6. Phagocytosis of sperm by follicle cells of the carnivorous sponge Asbestopluma occidentalis (Porifera, Demospongiae).

    PubMed

    Riesgo, Ana

    2010-06-01

    During spermatogenesis of the carnivorous sponge Asbestopluma occidentalis, follicle cells that lined the spermatocysts phagocytosed unreleased mature sperm. Such follicle cells are part of the complex envelope that limits spermatocysts of A. occidentalis, which is also comprised of a collagen layer, a thick layer of intertwined cells, and spicules. Follicle cells showed vesicles containing single phagocytosed spermatozoa within their cytoplasm. Additionally, lipids and other inclusions were observed within the cytoplasm of follicle cells. It is likely that follicle cells recapture nutrients by phagocytosing spermatozoa and use them to form lipids and other inclusions. Such sperm phagocytosis is usually performed in higher invertebrates and vertebrates by Sertoli cells that are located in the testis wall. While Sertoli cells develop a wide range of functions such as creating a blood-testis barrier, providing crucial factors to ensure correct progression of spermatogenesis, and phagocytosis of aberrant, degenerating, and unreleased sperm cells, sponge follicle cells may only display phagocytotic activity on spermatogenic cells. PMID:20409567

  7. Development of an improved bone washing and demineralisation process to produce large demineralised human cancellous bone sponges.

    PubMed

    Eagle, Mark J; Rooney, Paul; Kearney, John N

    2015-12-01

    Shaped demineralised bone matrices (DBM) made from cancellous bone have important uses in orthopaedic and dental procedures, where the properties of the material allow its insertion into confined defects, therefore acting as a void filler and scaffold onto which new bone can form. The sponges are often small in size, <1.0 cm(3). In this study, we report on an improved bone washing and demineralisation process that allows production of larger DBM sponges (3.375 or 8.0 cm(3)) from deceased donor bone. These sponges were taken through a series of warm water washes, some with sonication, centrifugation, 100 % ethanol and two decontamination chemical washes and optimally demineralised using 0.5 N hydrochloric acid under vacuum. Demineralisation was confirmed by quantitative measurement of calcium and qualitatively by compression. Protein and DNA removal was also determined. The DBM sponges were freeze dried before terminal sterilisation with a target dose of 25 kGy gamma irradiation whilst frozen. Samples of the sponges were examined histologically for calcium, collagen and the presence of cells. The data indicated lack of cells, absence of bone marrow and a maximum of 1.5 % residual calcium. PMID:25736401

  8. Enigmatic insight into collagen.

    PubMed

    Deshmukh, Shrutal Narendra; Dive, Alka M; Moharil, Rohit; Munde, Prashant

    2016-01-01

    Collagen is a unique, triple helical molecule which forms the major part of extracellular matrix. It is the most abundant protein in the human body, representing 30% of its dry weight. It is the fibrous structural protein that makes up the white fibers (collagen fibers) of skin, tendons, bones, cartilage and all other connective tissues. Collagens are not only essential for the mechanical resistance and resilience of multicellular organisms, but are also signaling molecules defining cellular shape and behavior. The human body has at least 16 types of collagen, but the most prominent types are I, II and III. Collagens are produced by several cell types and are distinguishable by their molecular compositions, morphologic characteristics, distribution, functions and pathogenesis. This is the major fibrous glycoprotein present in the extracellular matrix and in connective tissue and helps in maintaining the structural integrity of these tissues. It has a triple helical structure. Various studies have proved that mutations that modify folding of the triple helix result in identifiable genetic disorders. Collagen diseases share certain similarities with autoimmune diseases, because autoantibodies specific to each collagen disease are produced. Therefore, this review highlights the role of collagen in normal health and also the disorders associated with structural and functional defects in collagen. PMID:27601823

  9. Collagen and gelatin.

    PubMed

    Liu, Dasong; Nikoo, Mehdi; Boran, Gökhan; Zhou, Peng; Regenstein, Joe M

    2015-01-01

    Collagen and gelatin have been widely used in the food, pharmaceutical, and cosmetic industries due to their excellent biocompatibility, easy biodegradability, and weak antigenicity. Fish collagen and gelatin are of renewed interest, owing to the safety and religious concerns of their mammalian counterparts. The structure of collagen has been studied using various modern technologies, and interpretation of the raw data should be done with caution. The structure of collagen may vary with sources and seasons, which may affect its applications and optimal extraction conditions. Numerous studies have investigated the bioactivities and biological effects of collagen, gelatin, and their hydrolysis peptides, using both in vitro and in vivo assay models. In addition to their established nutritional value as a protein source, collagen and collagen-derived products may exert various potential biological activities on cells in the extracellular matrix through the corresponding food-derived peptides after ingestion, and this might justify their applications in dietary supplements and pharmaceutical preparations. Moreover, an increasing number of novel applications have been found for collagen and gelatin. Therefore, this review covers the current understanding of the structure, bioactivities, and biological effects of collagen, gelatin, and gelatin hydrolysates as well as their most recent applications. PMID:25884286

  10. Enigmatic insight into collagen

    PubMed Central

    Deshmukh, Shrutal Narendra; Dive, Alka M; Moharil, Rohit; Munde, Prashant

    2016-01-01

    Collagen is a unique, triple helical molecule which forms the major part of extracellular matrix. It is the most abundant protein in the human body, representing 30% of its dry weight. It is the fibrous structural protein that makes up the white fibers (collagen fibers) of skin, tendons, bones, cartilage and all other connective tissues. Collagens are not only essential for the mechanical resistance and resilience of multicellular organisms, but are also signaling molecules defining cellular shape and behavior. The human body has at least 16 types of collagen, but the most prominent types are I, II and III. Collagens are produced by several cell types and are distinguishable by their molecular compositions, morphologic characteristics, distribution, functions and pathogenesis. This is the major fibrous glycoprotein present in the extracellular matrix and in connective tissue and helps in maintaining the structural integrity of these tissues. It has a triple helical structure. Various studies have proved that mutations that modify folding of the triple helix result in identifiable genetic disorders. Collagen diseases share certain similarities with autoimmune diseases, because autoantibodies specific to each collagen disease are produced. Therefore, this review highlights the role of collagen in normal health and also the disorders associated with structural and functional defects in collagen. PMID:27601823

  11. Cell kinetics during regeneration in the sponge Halisarca caerulea: how local is the response to tissue damage?

    PubMed

    Alexander, Brittany E; Achlatis, Michelle; Osinga, Ronald; van der Geest, Harm G; Cleutjens, Jack P M; Schutte, Bert; de Goeij, Jasper M

    2015-01-01

    Sponges have a remarkable capacity to rapidly regenerate in response to wound infliction. In addition, sponges rapidly renew their filter systems (choanocytes) to maintain a healthy population of cells. This study describes the cell kinetics of choanocytes in the encrusting reef sponge Halisarca caerulea during early regeneration (0-8 h) following experimental wound infliction. Subsequently, we investigated the spatial relationship between regeneration and cell proliferation over a six-day period directly adjacent to the wound, 1 cm, and 3 cm from the wound. Cell proliferation was determined by the incorporation of 5-bromo-2'-deoxyuridine (BrdU). We demonstrate that during early regeneration, the growth fraction of the choanocytes (i.e., the percentage of proliferative cells) adjacent to the wound is reduced (7.0 ± 2.5%) compared to steady-state, undamaged tissue (46.6 ± 2.6%), while the length of the cell cycle remained short (5.6 ± 3.4 h). The percentage of proliferative choanocytes increased over time in all areas and after six days of regeneration choanocyte proliferation rates were comparable to steady-state tissue. Tissue areas farther from the wound had higher rates of choanocyte proliferation than areas closer to the wound, indicating that more resources are demanded from tissue in the immediate vicinity of the wound. There was no difference in the number of proliferative mesohyl cells in regenerative sponges compared to steady-state sponges. Our data suggest that the production of collagen-rich wound tissue is a key process in tissue regeneration for H. caerulea, and helps to rapidly occupy the bare substratum exposed by the wound. Regeneration and choanocyte renewal are competing and negatively correlated life-history traits, both essential to the survival of sponges. The efficient allocation of limited resources to these life-history traits has enabled the ecological success and diversification of sponges. PMID:25780772

  12. Cell kinetics during regeneration in the sponge Halisarca caerulea: how local is the response to tissue damage?

    PubMed Central

    Achlatis, Michelle; Osinga, Ronald; van der Geest, Harm G.; Cleutjens, Jack P.M.; Schutte, Bert; de Goeij, Jasper M.

    2015-01-01

    Sponges have a remarkable capacity to rapidly regenerate in response to wound infliction. In addition, sponges rapidly renew their filter systems (choanocytes) to maintain a healthy population of cells. This study describes the cell kinetics of choanocytes in the encrusting reef sponge Halisarca caerulea during early regeneration (0–8 h) following experimental wound infliction. Subsequently, we investigated the spatial relationship between regeneration and cell proliferation over a six-day period directly adjacent to the wound, 1 cm, and 3 cm from the wound. Cell proliferation was determined by the incorporation of 5-bromo-2′-deoxyuridine (BrdU). We demonstrate that during early regeneration, the growth fraction of the choanocytes (i.e., the percentage of proliferative cells) adjacent to the wound is reduced (7.0 ± 2.5%) compared to steady-state, undamaged tissue (46.6 ± 2.6%), while the length of the cell cycle remained short (5.6 ± 3.4 h). The percentage of proliferative choanocytes increased over time in all areas and after six days of regeneration choanocyte proliferation rates were comparable to steady-state tissue. Tissue areas farther from the wound had higher rates of choanocyte proliferation than areas closer to the wound, indicating that more resources are demanded from tissue in the immediate vicinity of the wound. There was no difference in the number of proliferative mesohyl cells in regenerative sponges compared to steady-state sponges. Our data suggest that the production of collagen-rich wound tissue is a key process in tissue regeneration for H. caerulea, and helps to rapidly occupy the bare substratum exposed by the wound. Regeneration and choanocyte renewal are competing and negatively correlated life-history traits, both essential to the survival of sponges. The efficient allocation of limited resources to these life-history traits has enabled the ecological success and diversification of sponges. PMID:25780772

  13. Multi-Composite Bioactive Osteogenic Sponges Featuring Mesenchymal Stem Cells, Platelet-Rich Plasma, Nanoporous Silicon Enclosures, and Peptide Amphiphiles for Rapid Bone Regeneration

    PubMed Central

    Murphy, Matthew B.; Blashki, Daniel; Buchanan, Rachel M.; Fan, Dongmei; De Rosa, Enrica; Shah, Ramille N.; Stupp, Samuel I.; Weiner, Bradley K.; Simmons, Paul J.; Ferrari, Mauro; Tasciotti, Ennio

    2011-01-01

    A novel bioactive sponge was created with a composite of type I collagen sponges or porous poly(ε-caprolactone) (PCL) scaffolds, platelet-rich plasma (PRP), BMP2-loaded nanoporous silicon enclosure (NSE) microparticles, mineralizing peptide amphiphiles (PA), and mesenchymal stem cells (MSC). Primary MSC from cortical bone (CB) tissue proved to form more and larger colony units, as well as produce more mineral matrix under osteogenic differentiation, than MSC from bone marrow (BM). Coating pre-treatments were optimized for maximum cell adhesion and mineralization, while a PRP-based gel carrier was created to efficiently deliver and retain MSC and microparticles within a porous scaffold while simultaneously promoting cell recruitment, proliferation, and angiogenesis. Components and composite sponges were evaluated for osteogenic differentiation in vitro. Osteogenic sponges were loaded with MSC, PRP, PA, and NSE and implanted subcutaneously in rats to evaluate the formation of bone tissue and angiogenesis in vivo. It was found that the combination of a collagen sponge with CB MSC, PRP, PA, and the BMP2-releasing NSE formed the most bone and was most vascularized by four weeks compared to analogous composites featuring BM MSC or PCL or lacking PRP, PA, and NSE. This study indicates that CB MSC should be considered as an alternative to marrow as a source of stem cells, while the PRP-PA cell and microparticle delivery system may be utilized for diverse tissue engineering applications. PMID:24956163

  14. Molecular characterization and expression analysis of the first Porifera tumor necrosis factor superfamily member and of its putative receptor in the marine sponge Chondrosia reniformis.

    PubMed

    Pozzolini, Marina; Scarfì, Sonia; Ghignone, Stefano; Mussino, Francesca; Vezzulli, Luigi; Cerrano, Carlo; Giovine, Marco

    2016-04-01

    Here we report the molecular cloning and characterization of the first Tumor Necrosis Factor homologous and of its putative receptor in the marine sponge Chondrosia reniformis: chTNF and chTNFR, respectively. The deduced chTNF amino acid sequence is a type II transmembrane protein containing the typical TNFSF domain. Phylogenetic analysis reveals that chTNF is more related to Chordata TNFs rather than to other invertebrates. chTNF and chTNFR are constitutively expressed both in the ectosome and in the choanosome of the sponge, with higher levels in the ectosome. chTNF and chTNFR mRNAs were monitored in sponge fragmorphs treated with Gram(+) or Gram(-) bacteria. chTNF was significantly upregulated in Gram(+)-treated fragmorphs as compared to controls, while chTNFR was upregulated by both treatments. Finally, the possible chTNF fibrogenic role in sponge fragmorphs was studied by TNF inhibitor treatment measuring fibrillar and non fibrillar collagen gene expression; results indicate that the cytokine is involved in sponge collagen deposition and homeostasis. PMID:26705701

  15. Activated chemical defense in aplysina sponges revisited.

    PubMed

    Thoms, Carsten; Ebel, Rainer; Proksch, Peter

    2006-01-01

    Sponges of the genus Aplysina accumulate brominated isoxazoline alkaloids in concentrations that sometimes exceed 10% of their dry weight. We previously reported a decrease in concentrations of these compounds and a concomitant increase in concentrations of the monocyclic nitrogenous compounds aeroplysinin-1 and dienone in Aplysina aerophoba following injury of the sponge tissue. Further investigations indicated a wound-induced enzymatic cleavage of the former compounds into the latter, and demonstrated that these reactions also occur in other Aplysina sponges. A recent study on Caribbean Aplysina species, however, introduced doubt regarding the presence of a wound-induced bioconversion in sponges of this genus. This discrepancy motivated us to reinvestigate carefully the fate of brominated alkaloids in A. aerophoba and in other Aplysina sponges following mechanical injury. As a result of this study we conclude that (1) tissue damage induces a bioconversion of isoxazoline alkaloids into aeroplysinin-1 and dienone in Aplysina sponges, (2) this reaction is likely catalyzed by enzymes, and (3) it may be ecologically relevant as the bioconversion products possibly protect the wounded sponge tissue from invasion of bacterial pathogens. PMID:16525873

  16. Diversity of fungal isolates from three Hawaiian marine sponges.

    PubMed

    Li, Quanzi; Wang, Guangyi

    2009-01-01

    Sponges harbor diverse prokaryotic and eukaryotic microbes. However, the nature of sponge-fungal association and diversity of sponge-derived fungi have barely been addressed. In this study, the cultivation-dependent approach was applied to study fungal diversity in the Hawaiian sponges Gelliodes fibrosa, Haliclona caerulea, and Mycale armata. The cultivated fungal isolates were representatives of 8 taxonomic orders, belonging to at least 25 genera of Ascomycota and 1 of Basidiomycota. A portion of these isolates (n=15, 17%) were closely affiliated with fungal isolates isolated from other marine habitats; the rest of the isolates had affiliation with terrestrial fungal strains. Cultivated fungal isolates were classified into 3 groups: 'sponge-generalists'-found in all sponge species, 'sponge-associates'-found in more than one sponge species, and 'sponge-specialists'-found only in one sponge species. Individuals of G. fibrosa collected at two different locations shared the same group of 'sponge-specialists'. Also, representatives of 15 genera were identified for the first time in marine sponges. Large-scale phylogenetic analysis of sponge-derived fungi may provide critical information to distinguish between 'resident fungi' and 'transient fungi' in sponges as it has been done in other marine microbial groups. This is the first report of the host specificity analysis of culturable fungal communities in marine sponges. PMID:17681460

  17. Assessing the complex sponge microbiota: core, variable and species-specific bacterial communities in marine sponges

    PubMed Central

    Schmitt, Susanne; Tsai, Peter; Bell, James; Fromont, Jane; Ilan, Micha; Lindquist, Niels; Perez, Thierry; Rodrigo, Allen; Schupp, Peter J; Vacelet, Jean; Webster, Nicole; Hentschel, Ute; Taylor, Michael W

    2012-01-01

    Marine sponges are well known for their associations with highly diverse, yet very specific and often highly similar microbiota. The aim of this study was to identify potential bacterial sub-populations in relation to sponge phylogeny and sampling sites and to define the core bacterial community. 16S ribosomal RNA gene amplicon pyrosequencing was applied to 32 sponge species from eight locations around the world's oceans, thereby generating 2567 operational taxonomic units (OTUs at the 97% sequence similarity level) in total and up to 364 different OTUs per sponge species. The taxonomic richness detected in this study comprised 25 bacterial phyla with Proteobacteria, Chloroflexi and Poribacteria being most diverse in sponges. Among these phyla were nine candidate phyla, six of them found for the first time in sponges. Similarity comparison of bacterial communities revealed no correlation with host phylogeny but a tropical sub-population in that tropical sponges have more similar bacterial communities to each other than to subtropical sponges. A minimal core bacterial community consisting of very few OTUs (97%, 95% and 90%) was found. These microbes have a global distribution and are probably acquired via environmental transmission. In contrast, a large species-specific bacterial community was detected, which is represented by OTUs present in only a single sponge species. The species-specific bacterial community is probably mainly vertically transmitted. It is proposed that different sponges contain different bacterial species, however, these bacteria are still closely related to each other explaining the observed similarity of bacterial communities in sponges in this and previous studies. This global analysis represents the most comprehensive study of bacterial symbionts in sponges to date and provides novel insights into the complex structure of these unique associations. PMID:21993395

  18. Collagen: Biochemistry, biomechanics, biotechnology

    SciTech Connect

    Nimni, M.E.

    1988-01-01

    This book is an up-to-date reference for new ideas, information, and concepts in collagen research. The first volume emphasizes the relationship between the molecular structure and function of collagen, including descriptions of collagen types which exist in tissues as well as how these molecules organize into fibrils and the nature of the chemical crosslinks which stabilize them. In Volume II the biomechanical behavior of various specialized tissues, abnormal accumulation of collagen in the form of scars of fibrous infiltration are examined/and wound healing, tissue regulation and repair are covered in detail. Volume III explores the increasing application of collagen technology to the field of bioprosthesis, including the production of heart valve bioprosthesis, blood vessels, ligament substitutes, and bone substitutes.

  19. Oxidative damage to collagen.

    PubMed

    Monboisse, J C; Borel, J P

    1992-01-01

    Extracellular matrix molecules, such as collagens, are good targets for oxygen free radicals. Collagen is the only protein susceptible to fragmentation by superoxide anion as demonstrated by the liberation of small 4-hydroxyproline-containing-peptides. It seems likely that hydroxyl radicals in the presence of oxygen cleave collagen into small peptides, and the cleavage seems to be specific to proline or 4-hydroxyproline residues. Hydroxyl radicals in the absence of oxygen or hypochlorous acid do not induce fragmentation of collagen molecules, but they trigger a polymerization of collagen through the formation of new cross-links such as dityrosine or disulfure bridges. Moreover, these cross-links can not explain the totality of high molecular weight components generated under these experimental conditions, and the nature of new cross-links induced by hydroxyl radicals or hypochlorous acid remains unclear. PMID:1333311

  20. Superoxide radical production by sponges Sycon sp.

    PubMed

    Peskin, A V; Labas, Y A; Tikhonov, A N

    1998-08-28

    Using the catechol Tiron as an O2-. scavenger, we showed that sea sponges (Sycon sp.) produce superoxide radicals in sea water at a high rate without any stimuli added. The rate of O2-. outflow from sponges to their water surroundings reaches a value of 0.5 nmol/min per sponge at pH 6.5. The generation of O2-. was inhibited by Cu,Zn-superoxide dismutase, and restored by the addition of KCN. We also confirmed the abiotic production of O2-. in sea water, detected earlier with a different method by Petasne and Zika [Nature 325 (1987) 516-518]. PMID:9738478

  1. Stability of collagen with polyols against guanidine denaturation.

    PubMed

    Usha, R; Ramasami, T

    2008-01-15

    The effect of polyol osmolytes such as erythritol, xylitol and sorbitol on the protection of collagen against guanidine hydrochloride (GdmCl) was studied using circular dichroism and fluorescence spectroscopy. Collagen was denatured by various concentrations of GdmCl in the presence of polyols. The absorbance was high for GdmCl treated collagen than native and polyols treated analogue. Fluorescence emission properties were studied at the excitation wavelength of 235 nm. The emission wavelength is red shifted from 308 to 370 nm for GdmCl treated collagen with polyols. Increasing the concentration of GdmCl did not affect the peak position. CD studies proved that the aggregation of collagen in the presence of lower concentrations of GdmCl. At higher concentrations of GdmCl due to the loss of secondary structure no clear CD spectra were observed. This shows that the unfolding of collagen is closely related to GdmCl concentrations. The ability of the polyols to protect collagen against guanidine denaturation decreased in order from erythritol to xylitol to sorbitol. The presence of OH group in the solvent structure is important for stabilization of collagen due to the formation of additional stabilizing hydrogen bonds. PMID:17720461

  2. Effects of powder from white cabbage outer leaves on sponge cake quality

    NASA Astrophysics Data System (ADS)

    Prokopov, Tsvetko; Goranova, Zhivka; Baeva, Marianna; Slavov, Anton; Galanakis, Charis M.

    2015-10-01

    The main objective of this study was to develop high fibre cakes utilizing and valorising cabbage by-products - cabbage outer leaves. Cabbage outer leaves were dried and milled in order to produce cabbage leaf powder. The cabbage leaf powder was added at 0, 10, 20% into sponge cake. All of the samples were subjected to physicochemical analysis and sensory evaluation. Methods of descriptive sensory analysis were used for a comparative analysis of the sponge cakes with cabbage leaf powder and the cake without cabbage leaf powder. Addition of cabbage leaf powder in sponge cakes significantly affected the cake volume and textural properties. Springiness of cakes with cabbage leaf powder and crumb tenderness were lower, while the structure was stable at high loads, as expressed by lower shrinkage in comparison with the control cake. The nutritional value of the sponge cakes with cabbage leaf powder was lower than the control cake. The cells cakes modified by cabbage leaf powder were smaller and almost equal, uniformly distributed in the crumb, and at the same time had thicker walls. The cakes with addition of cabbage leaf powder showed the springiness and their crumb tenderness were lower, while their structure was stable at high loads. Control cake showed higher water-absorbing capacity compared to the cakes with 10 and 20% cabbage leaf powder.

  3. In vitro mitomycin C absorption and delivery with different sponge materials used in filtering surgery

    PubMed Central

    Urbaneja, Diana; Morilla-Grasa, Antonio; Jimenez, Elisa; Montemayor, Judith; Marcobal, Nuria; Aragay, Carme; Gurdiel, Celia; Armillas, Marta; Ortiz, Pere; Antón, Alfonso

    2016-01-01

    Purpose The purpose of this study is to evaluate and compare mitomycin C (MMC) absorption and delivery in different materials used in filtering surgery. Methods This is an in vitro study comparing polyvinyl alcohol triangular sponges (TS6, TS8), polyvinyl alcohol fluid wicks (EFW), and absorbable gelatin sponges (AGS3, AGS5), from which five different types of transport units were obtained. Seven pieces of sponge of each transport unit type were obtained as follows: two transverse strips were obtained at 6 and 8 mm from the apex of TS and divided into three equal pieces; 4×4 mm pieces of EFW; 3×3 and 5×5 mm pieces of absorbable gelatin sponges were cut. Filter paper was placed on a precision scale (0.01 mg). The seven sponge pieces of each type were weighed three times consecutively in dry and wet states, the latter after immersion for 15 seconds in 0.2 mg/mL MMC. The difference between the weights of the dry and wet filter paper at the end of each measurement sequence was also calculated and considered as an estimate of the amount of mitomycin delivered. Results The amounts of MMC absorbed by each transport unit were as follows: (mean ± standard deviation) 27.43±5.13 for TS6, 31.91±6.63 for TS8, 15.96±2.23 for EFW, 17.96±2.05 for AGS3, and 33.81±2.05 for AGS5. The amounts of MMC delivered to the filter paper were as follows: 21.70±2.84 for TS6, 23.83±4.03 for TS8, 12.93±1.75 for EFW, 14.69±1.79 for AGS3, and 27.30±1.58 for AGS5. Conclusion Percentage MMC delivered was similar for all materials, but there was a tendency for greater delivery using larger sponges and greater homogeneity in delivery with AGS5. No statistical differences were found in percentage delivered by the different transport materials. PMID:27143843

  4. Soft chemistry based sponge-like indium tin oxide (ITO) — a prospective component of photoanode for solar cell application

    NASA Astrophysics Data System (ADS)

    Biswas, Prasanta Kumar; Das, Nilanjana

    2015-04-01

    Previously we reported the synthesis of novel organic-inorganic composite indium tin oxide (ITO) foam precursor leading to the formation of "sponge-like" ITO by burning away the organics. This newly made sponge-like ITO possesses relatively high electrical conductivity due to phonon confinement with reasonable pore structure and may have potential application as functional materials in semiconducting dye absorbing layer in dye-sensitized solar cell (DSSC) and also as the receptor of electrons injected from the quantum dots (QDs) of organic-inorganic hybrid QD based solar cell. This report is a short review of "sponge-like" ITO described as a lecture note on its future use as an alternative new prospective material for photoanode of solar cell in the domain of sustainable energy.

  5. Collagenous Colitis and Spondylarthropathy

    PubMed Central

    Ben Abdelghani, Kaouther; Sahli, Hana; Souabni, Leila; Chekili, Selma; Belhadj, Salwa; Kassab, Selma; Laatar, Ahmed; Zakraoui, Leith

    2012-01-01

    Collagenous colitis is a recent cause of chronic diarrhea. Cooccurrence with spondylarthropathy is rare. We describe two cases: one man and one woman of 33 and 20 years old were suffering from spondylarthropathy. They then developed collagenous colitis, 4 and 14 years after the onset of spondylarthropathy. The diagnosis was based on histological features. A sicca syndrome and vitiligo were observed with the female case. The presence of colitis leads to therapeutic problems. This association suggests a systemic kind of rheumatic disease of collagenous colitis. PMID:22701491

  6. Nanomechanics of collagen microfibrils

    PubMed Central

    Vesentini, Simone; Redaelli, Alberto; Gautieri, Alfonso

    2013-01-01

    Summary Collagen constitutes one third of the human proteome, providing mechanical stability, elasticity and strength to organisms and is thus the prime construction material in biology. Collagen is also the dominating material in the extracellular matrix where its stiffness controls cell differentiation, growth and pathology. We use atomistic-based hierarchical multiscale modeling to describe this complex biological material from the bottom up. This includes the use and development of large-scale computational modeling tools to investigate several aspects related to collagen-based tissues, including source of visco-elasticity and deformation mechanisms at the nanoscale level. The key innovation of this research is that until now, collagen materials have primarily been described at macroscopic scales, without explicitly understanding the mechanical contributions at the molecular and fibrillar levels. The major impact of this research will be the development of fundamental models of collagenous tissues, important to the design of new scaffolding biomaterials for regenerative medicine as well as for the understanding of collagen-related diseases. PMID:23885342

  7. Environmental Shaping of Sponge Associated Archaeal Communities

    PubMed Central

    Turque, Aline S.; Batista, Daniela; Silveira, Cynthia B.; Cardoso, Alexander M.; Vieira, Ricardo P.; Moraes, Fernando C.; Clementino, Maysa M.; Albano, Rodolpho M.; Paranhos, Rodolfo; Martins, Orlando B.; Muricy, Guilherme

    2010-01-01

    Background Archaea are ubiquitous symbionts of marine sponges but their ecological roles and the influence of environmental factors on these associations are still poorly understood. Methodology/Principal Findings We compared the diversity and composition of archaea associated with seawater and with the sponges Hymeniacidon heliophila, Paraleucilla magna and Petromica citrina in two distinct environments: Guanabara Bay, a highly impacted estuary in Rio de Janeiro, Brazil, and the nearby Cagarras Archipelago. For this we used metagenomic analyses of 16S rRNA and ammonia monooxygenase (amoA) gene libraries. Hymeniacidon heliophila was more abundant inside the bay, while P. magna was more abundant outside and P. citrina was only recorded at the Cagarras Archipelago. Principal Component Analysis plots (PCA) generated using pairwise unweighted UniFrac distances showed that the archaeal community structure of inner bay seawater and sponges was different from that of coastal Cagarras Archipelago. Rarefaction analyses showed that inner bay archaeaoplankton were more diverse than those from the Cagarras Archipelago. Only members of Crenarchaeota were found in sponge libraries, while in seawater both Crenarchaeota and Euryarchaeota were observed. Although most amoA archaeal genes detected in this study seem to be novel, some clones were affiliated to known ammonia oxidizers such as Nitrosopumilus maritimus and Cenarchaeum symbiosum. Conclusion/Significance The composition and diversity of archaeal communities associated with pollution-tolerant sponge species can change in a range of few kilometers, probably influenced by eutrophication. The presence of archaeal amoA genes in Porifera suggests that Archaea are involved in the nitrogen cycle within the sponge holobiont, possibly increasing its resistance to anthropogenic impacts. The higher diversity of Crenarchaeota in the polluted area suggests that some marine sponges are able to change the composition of their associated

  8. Seasonal variation of Fatty acids and stable carbon isotopes in sponges as indicators for nutrition: biomarkers in sponges identified.

    PubMed

    Koopmans, Marieke; van Rijswijk, Pieter; Boschker, Henricus T S; Marco, Houtekamer; Martens, Dirk; Wijffels, Rene H

    2015-02-01

    To get a better understanding of sponge feeding biology and efficiencies, the fatty acid (FA) composition and (13)C natural abundance of sponges and of suspended particulate matter (SPM) from surrounding seawater was studied in different seasons at three locations. Haliclona oculata and Haliclona xena from the Oosterschelde, the Netherlands, Halichondria panicea and H. xena from Lake Veere, the Netherlands, and Aplysina aerophoba and Dysidea avara from the Mediterranean, Spain, were studied. Several FA biomarkers for different algal groups, bacteria and sponge biomass were identified in all sponges. The FA concentration variation in sponges was related to changes in fatty acid concentration in SPM. Stable carbon isotopic ratios (δ(13)C) in sponge specific FAs showed very limited seasonal variation at all sites. Algal FAs in sponges were mainly acquired from the SPM through active filtration in all seasons. At the two sites in the Netherlands only in May (spring), the sponge specific FAs had similar δ(13)C ratios as algal FAs, suggesting that sponges were mainly growing during spring and probably summer. During autumn and winter, they were still actively filtering, but the food collected during this period had little effect on sponge δ(13)C values suggesting limited incorporation of filtered material into the sponge body. The sponge A. aerophoba relied mostly on the symbiotic bacteria. In conclusion, fatty acid composition in combination with stable carbon isotope analysis can be used to analyze the food source of sponges. PMID:25107690

  9. Type V collagen controls the initiation of collagen fibril assembly.

    PubMed

    Wenstrup, Richard J; Florer, Jane B; Brunskill, Eric W; Bell, Sheila M; Chervoneva, Inna; Birk, David E

    2004-12-17

    Vertebrate collagen fibrils are heterotypically composed of a quantitatively major and minor fibril collagen. In non-cartilaginous tissues, type I collagen accounts for the majority of the collagen mass, and collagen type V, the functions of which are poorly understood, is a minor component. Type V collagen has been implicated in the regulation of fibril diameter, and we reported recently preliminary evidence that type V collagen is required for collagen fibril nucleation (Wenstrup, R. J., Florer, J. B., Cole, W. G., Willing, M. C., and Birk, D. E. (2004) J. Cell. Biochem. 92, 113-124). The purpose of this study was to define the roles of type V collagen in the regulation of collagen fibrillogenesis and matrix assembly. Mouse embryos completely deficient in pro-alpha1(V) chains were created by homologous recombination. The col5a1-/- animals die in early embryogenesis, at approximately embryonic day 10. The type V collagen-deficient mice demonstrate a virtual lack of collagen fibril formation. In contrast, the col5a1+/- animals are viable. The reduced type V collagen content is associated with a 50% reduction in fibril number and dermal collagen content. In addition, relatively normal, cylindrical fibrils are assembled with a second population of large, structurally abnormal collagen fibrils. The structural properties of the abnormal matrix are decreased relative to the wild type control animals. These data indicate a central role for the evolutionary, ancient type V collagen in the regulation of fibrillogenesis. The complete dependence of fibril formation on type V collagen is indicative of the critical role of the latter in early fibril initiation. In addition, this fibril collagen is important in the determination of fibril structure and matrix organization. PMID:15383546

  10. Application of thermal model for pan evaporation to the hydrology of a defined medium, the sponge

    NASA Technical Reports Server (NTRS)

    Trenchard, M. H.; Artley, J. A. (Principal Investigator)

    1981-01-01

    A technique is presented which estimates pan evaporation from the commonly observed values of daily maximum and minimum air temperatures. These two variables are transformed to saturation vapor pressure equivalents which are used in a simple linear regression model. The model provides reasonably accurate estimates of pan evaporation rates over a large geographic area. The derived evaporation algorithm is combined with precipitation to obtain a simple moisture variable. A hypothetical medium with a capacity of 8 inches of water is initialized at 4 inches. The medium behaves like a sponge: it absorbs all incident precipitation, with runoff or drainage occurring only after it is saturated. Water is lost from this simple system through evaporation just as from a Class A pan, but at a rate proportional to its degree of saturation. The contents of the sponge is a moisture index calculated from only the maximum and minium temperatures and precipitation.

  11. Collagen Hydrogel Scaffold and Fibroblast Growth Factor-2 Accelerate Periodontal Healing of Class II Furcation Defects in Dog

    PubMed Central

    Momose, Takehito; Miyaji, Hirofumi; Kato, Akihito; Ogawa, Kosuke; Yoshida, Takashi; Nishida, Erika; Murakami, Syusuke; Kosen, Yuta; Sugaya, Tsutomu; Kawanami, Masamitsu

    2016-01-01

    Objective: Collagen hydrogel scaffold exhibits bio-safe properties and facilitates periodontal wound healing. However, regenerated tissue volume is insufficient. Fibroblast growth factor-2 (FGF2) up-regulates cell behaviors and subsequent wound healing. We evaluated whether periodontal wound healing is promoted by application of collagen hydrogel scaffold in combination with FGF2 in furcation defects in beagle dogs. Methods: Collagen hydrogel was fabricated from bovine type I collagen with an ascorbate-copper ion cross-linking system. Collagen hydrogel was mingled with FGF2 and injected into sponge-form collagen. Subsequently, FGF2 (50 µg)/collagen hydrogel scaffold and collagen hydrogel scaffold alone were implanted into class II furcation defects in dogs. In addition, no implantation was performed as a control. Histometric parameters were assessed at 10 days and 4 weeks after surgery. Result: FGF2 application to scaffold promoted considerable cell and tissue ingrowth containing numerous cells and blood vessel-like structure at day 10. At 4 weeks, reconstruction of alveolar bone was stimulated by implantation of scaffold loaded with FGF2. Furthermore, periodontal attachment, consisting of cementum-like tissue, periodontal ligament-like tissue and Sharpey’s fibers, was also repaired, indicating that FGF2-loaded scaffold guided self-assembly and then re-established the function of periodontal organs. Aberrant healing, such as ankylosis and root resorption, was not observed. Conclusion: FGF2-loaded collagen hydrogel scaffold possessed excellent biocompatibility and strongly promoted periodontal tissue engineering, including periodontal attachment re-organization. PMID:27583044

  12. Development of collagen-hydroxyapatite nanostructured composites via a calcium phosphate precursor mechanism

    NASA Astrophysics Data System (ADS)

    Jee, Sang Soo

    Bone is an interpenetrating inorganic/organic composite that consists of mineralized collagen fibrils, which is hierarchically organized into various structures. The structure of mineralized collagen fibril, in which nano-crystals of hydroxyapatite are embedded within the collagen fibrils, provides remarkable mechanical and bio-resorptive properties. Therefore, there have been many attempts to produce collagen-hydroxyapatite composites having a bone-like structure. However, duplication of even the most fundamental level of bone structure has not been easily achieved by conventional nucleation and growth techniques, which are based on the most widely accepted hypothesis of bone mineralization. In nature, the collagen fibril is mineralized via intrafibrillar mineralization, which produces preferentially oriented hydroxyapatite nano-crystals occupying the interstices in collagen fibrils. Our group has demonstrated that intrafibrillar mineralization can be achieved by using a new method based on the Polymer-Induced Liquid-Precursor (PILP) mineralization process. In the PILP process, a poly-anionic additive can produce an amorphous calcium phosphate precursor which enables us to achieve intrafibrillar mineralization of collagen. It is thought that the precursor is pulled into the interstices of the collagen fibrils via capillary forces, and upon solidification and crystallization of the precursor produces an interpenetrating composite with the nanostructured architecture of bone. In this dissertation, to demonstrate the effectiveness of the PILP process on the intrafibrillar mineralization of collagen fibril, various collagen scaffolds, such as turkey tendon, bovine tendon and synthetic collagen sponge, were mineralized by the PILP process. Various poly-aspartates with different molecular weight were also used for the optimization of the PILP process for the mineralization of the collagen scaffolds. With the systematic researches, we discovered that the molecular weight

  13. 16 CFR 501.6 - Cellulose sponges, irregular dimensions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 16 Commercial Practices 1 2011-01-01 2011-01-01 false Cellulose sponges, irregular dimensions. 501... REQUIREMENTS AND PROHIBITIONS UNDER PART 500 § 501.6 Cellulose sponges, irregular dimensions. Variety packages of cellulose sponges of irregular dimensions, are exempted from the requirements of § 500.25 of...

  14. 16 CFR 501.6 - Cellulose sponges, irregular dimensions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Cellulose sponges, irregular dimensions. 501... REQUIREMENTS AND PROHIBITIONS UNDER PART 500 § 501.6 Cellulose sponges, irregular dimensions. Variety packages of cellulose sponges of irregular dimensions, are exempted from the requirements of § 500.25 of...

  15. Solvent disperser for removing oil from sponge core

    SciTech Connect

    Di Foggio, R.

    1988-09-20

    This patent describes method for dispersing solvent for use in determining the oil saturation of an earth formation by means of sponge coring, comprising: (a) receiving solvent dripping downwardly, and (b) conducting the received solvent by means of capillary action to an application zone located and dimensioned for passing such solvent to the sponge in a sponge core barrel.

  16. 16 CFR 501.6 - Cellulose sponges, irregular dimensions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 16 Commercial Practices 1 2014-01-01 2014-01-01 false Cellulose sponges, irregular dimensions. 501... REQUIREMENTS AND PROHIBITIONS UNDER PART 500 § 501.6 Cellulose sponges, irregular dimensions. Variety packages of cellulose sponges of irregular dimensions, are exempted from the requirements of § 500.25 of...

  17. 16 CFR 501.6 - Cellulose sponges, irregular dimensions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 16 Commercial Practices 1 2013-01-01 2013-01-01 false Cellulose sponges, irregular dimensions. 501... REQUIREMENTS AND PROHIBITIONS UNDER PART 500 § 501.6 Cellulose sponges, irregular dimensions. Variety packages of cellulose sponges of irregular dimensions, are exempted from the requirements of § 500.25 of...

  18. 16 CFR 501.6 - Cellulose sponges, irregular dimensions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 16 Commercial Practices 1 2012-01-01 2012-01-01 false Cellulose sponges, irregular dimensions. 501... REQUIREMENTS AND PROHIBITIONS UNDER PART 500 § 501.6 Cellulose sponges, irregular dimensions. Variety packages of cellulose sponges of irregular dimensions, are exempted from the requirements of § 500.25 of...

  19. Oil/water separation performances of superhydrophobic and superoleophilic sponges.

    PubMed

    Ke, Qingping; Jin, Yangxin; Jiang, Peng; Yu, Jian

    2014-11-11

    Superhydrophobic and superoleophilic sponges were fabricated by immersion in an ethanol solution of octadecyltrichlorosilane. The resulting coating strongly adheres to the sponges after curing at 45 °C for 24 h. Absorption capacities of 42-68 times the polymerized octadecylsiloxane sponge weight were obtained for toluene, light petroleum, and methylsilicone oil. These adsorption capacities were maintained after 50 cycles. PMID:25340643

  20. A saccharide-based crystalline sponge for hydrophilic guests.

    PubMed

    Ning, Guo-Hong; Matsumura, Kazuki; Inokuma, Yasuhide; Fujita, Makoto

    2016-05-19

    A coordination network composed of a mannose-based organic ligand and a sodium ion, 'sugar sponge', was synthesized for the crystalline sponge analysis of hydrophilic compounds. Owing to multiple hydrogen-bonding interactions, hydrophilic guests are firmly trapped in the 1-dimensional channel. The sugar sponge was utilized to analyze the structures of flexible alcohol and absolute configurations of chiral epoxides. PMID:27157794

  1. Development of in vivo sponge cultures: particle feeding by the tropical sponge Pseudosuberites aff. andrewsi.

    PubMed

    Osinga, R; Kleijn, R; Groenendijk, E; Niesink, P; Tramper, J; Wijffels, R H

    2001-11-01

    The rate of food particle uptake of the tropical sponge Pseudosuberites aff. andrewsi was studied in relation to particle concentrations and particle size. A range of different concentrations of either the marine microalga Dunaliella tertiolecta (approximately 5-8 microm) or the marine cyanobacterium Synechococcus sp. (approximately 1 microm) was supplied to the sponges. D. tertiolecta had a pronounced effect on the filtration activity of the sponges: at concentrations higher than approximately 4 x 10(5) cells/cm(3), the filtration rates dropped dramatically. Such a clear effect was not found for Synechococcus sp. The results further showed that the maximal amount of food (when expressed in organic carbon) that can be taken up per cubic centimeter of sponge volume per unit of time should in principle be sufficient to enable growth (irrespective of the food particle type). At the maximal food particle concentration that did not affect the filtration rates, the uptake of organic carbon is already highly in excess of the amount of organic carbon that the sponges need to cope with their respiratory demand. Based on these findings, a series of growth experiments was carried out in which the sponges were subjected to a constant concentration of different types of food particles (Synechococcus sp. and the microalgae Chlorella sorokiniana and Nannochloropsis sp). Although initial growth was sometimes observed, continuous growth at a constant rate could not be obtained. It is concluded that qualitative aspects of feeding rather than quantitative aspects are the key to successful in vivo sponge culture. PMID:14961327

  2. Collagen type VI myopathies.

    PubMed

    Bushby, Kate M D; Collins, James; Hicks, Debbie

    2014-01-01

    Mutations in each of the three collagen VI genes COL6A1, COL6A2 and COL6A3 cause two main types of muscle disorders: Ullrich congenital muscular dystrophy, a severe phenotype, and a mild to moderate phenotype Bethlem myopathy. Recently, two additional phenotypes, including a limb-girdle muscular dystrophy phenotype and an autosomal recessive myosclerosis reported in one family with mutations in COL6A2 have been reported. Collagen VI is an important component of the extracellular matrix which forms a microfibrillar network that is found in close association with the cell and surrounding basement membrane. Collagen VI is also found in the interstitial space of many tissues including muscle, tendon, skin, cartilage, and intervertebral discs. Thus, collagen VI mutations result in disorders with combined muscle and connective tissue involvement, including weakness, joint laxity and contractures, and abnormal skin findings.In this review we highlight the four recognized clinical phenotypes of collagen VI related - myopathies; Ullrich congenital muscular dystrophy (UCMD), Bethlem myopathy (BM), autosomal dominant limb-girdle muscular dystrophy phenotype and autosomal recessive myosclerosis. We discuss the diagnostic criteria of these disorders, the molecular pathogenesis, genetics, treatment, and related disorders. PMID:24443028

  3. Oxygen dynamics and transport in the Mediterranean sponge Aplysina aerophoba.

    PubMed

    Hoffmann, Friederike; Røy, Hans; Bayer, Kristina; Hentschel, Ute; Pfannkuchen, Martin; Brümmer, Franz; de Beer, Dirk

    2008-01-01

    The Mediterranean sponge Aplysina aerophoba kept in aquaria or cultivation tanks can stop pumping for several hours or even days. To investigate changes in the chemical microenvironments, we measured oxygen profiles over the surface and into the tissue of pumping and non-pumping A. aerophoba specimens with Clark-type oxygen microelectrodes (tip diameters 18-30 μm). Total oxygen consumption rates of whole sponges were measured in closed chambers. These rates were used to back-calculate the oxygen distribution in a finite-element model. Combining direct measurements with calculations of diffusive flux and modeling revealed that the tissue of non-pumping sponges turns anoxic within 15 min, with the exception of a 1 mm surface layer where oxygen intrudes due to molecular diffusion over the sponge surface. Molecular diffusion is the only transport mechanism for oxygen into non-pumping sponges, which allows total oxygen consumption rates of 6-12 μmol cm(-3) sponge day(-1). Sponges of different sizes had similar diffusional uptake rates, which is explained by their similar surface/volume ratios. In pumping sponges, oxygen consumption rates were between 22 and 37 μmol cm(-3) sponge day(-1), and the entire tissue was oxygenated. Combining different approaches of direct oxygen measurement in living sponges with a dynamic model, we can show that tissue anoxia is a direct function of the pumping behavior. The sponge-microbe system of A. aerophoba thus has the possibility to switch actively between aerobic and anaerobic metabolism by stopping the water flow for more than 15 min. These periods of anoxia will greatly influence physiological variety and activity of the sponge microbes. Detailed knowledge about the varying chemical microenvironments in sponges will help to develop protocols to cultivate sponge-associated microbial lineages and improve our understanding of the sponge-microbe-system. PMID:24391232

  4. Collagen in organ development

    NASA Technical Reports Server (NTRS)

    Hardman, P.; Spooner, B. S.

    1992-01-01

    It is important to know whether microgravity will adversely affect developmental processes. Collagens are macromolecular structural components of the extracellular matrix (ECM) which may be altered by perturbations in gravity. Interstitial collagens have been shown to be necessary for normal growth and morphogenesis in some embryonic organs, and in the mouse salivary gland, the biosynthetic pattern of these molecules changes during development. Determination of the effects of microgravity on epithelial organ development must be preceded by crucial ground-based studies. These will define control of normal synthesis, secretion, and deposition of ECM macromolecules and the relationship of these processes to morphogenesis.

  5. Interstitial Collagen Catabolism*

    PubMed Central

    Fields, Gregg B.

    2013-01-01

    Interstitial collagen mechanical and biological properties are altered by proteases that catalyze the hydrolysis of the collagen triple-helical structure. Collagenolysis is critical in development and homeostasis but also contributes to numerous pathologies. Mammalian collagenolytic enzymes include matrix metalloproteinases, cathepsin K, and neutrophil elastase, and a variety of invertebrates and pathogens possess collagenolytic enzymes. Components of the mechanism of action for the collagenolytic enzyme MMP-1 have been defined experimentally, and insights into other collagenolytic mechanisms have been provided. Ancillary biomolecules may modulate the action of collagenolytic enzymes. PMID:23430258

  6. Stabilization and Anomalous Hydration of Collagen Fibril under Heating

    PubMed Central

    Gevorkian, Sasun G.; Allahverdyan, Armen E.; Gevorgyan, David S.; Simonian, Aleksandr L.; Hu, Chin-Kun

    2013-01-01

    Background Type I collagen is the most common protein among higher vertebrates. It forms the basis of fibrous connective tissues (tendon, chord, skin, bones) and ensures mechanical stability and strength of these tissues. It is known, however, that separate triple-helical collagen macromolecules are unstable at physiological temperatures. We want to understand the mechanism of collagen stability at the intermolecular level. To this end, we study the collagen fibril, an intermediate level in the collagen hierarchy between triple-helical macromolecule and tendon. Methodology/Principal Finding When heating a native fibril sample, its Young’s modulus decreases in temperature range 20–58°C due to partial denaturation of triple-helices, but it is approximately constant at 58–75°C, because of stabilization by inter-molecular interactions. The stabilization temperature range 58–75°C has two further important features: here the fibril absorbs water under heating and the internal friction displays a peak. We relate these experimental findings to restructuring of collagen triple-helices in fibril. A theoretical description of the experimental results is provided via a generalization of the standard Zimm-Bragg model for the helix-coil transition. It takes into account intermolecular interactions of collagen triple-helices in fibril and describes water adsorption via the Langmuir mechanism. Conclusion/Significance We uncovered an inter-molecular mechanism that stabilizes the fibril made of unstable collagen macromolecules. This mechanism can be relevant for explaining stability of collagen. PMID:24244320

  7. Polycyclic Guanidine Alkaloids from Poecilosclerida Marine Sponges

    PubMed Central

    Sfecci, Estelle; Lacour, Thierry; Amade, Philippe; Mehiri, Mohamed

    2016-01-01

    Sessile marine sponges provide an abundance of unique and diversified scaffolds. In particular, marine guanidine alkaloids display a very wide range of biological applications. A large number of cyclic guanidine alkaloids, including crambines, crambescins, crambescidins, batzelladines or netamins have been isolated from Poecilosclerida marine sponges. In this review, we will explore the chemodiversity of tri- and pentacyclic guanidine alkaloids. NMR and MS data tools will also be provided, and an overview of the wide range of bioactivities of crambescidins and batzelladines derivatives will be given. PMID:27070629

  8. The physiology and molecular biology of sponge tissues.

    PubMed

    Leys, Sally P; Hill, April

    2012-01-01

    Sponges have become the focus of studies on molecular evolution and the evolution of animal body plans due to their ancient branching point in the metazoan lineage. Whereas our former understanding of sponge function was largely based on a morphological perspective, the recent availability of the first full genome of a sponge (Amphimedon queenslandica), and of the transcriptomes of other sponges, provides a new way of understanding sponges by their molecular components. This wealth of genetic information not only confirms some long-held ideas about sponge form and function but also poses new puzzles. For example, the Amphimedon sponge genome tells us that sponges possess a repertoire of genes involved in control of cell proliferation and in regulation of development. In vitro expression studies with genes involved in stem cell maintenance confirm that archaeocytes are the main stem cell population and are able to differentiate into many cell types in the sponge including pinacocytes and choanocytes. Therefore, the diverse roles of archaeocytes imply differential gene expression within a single cell ontogenetically, and gene expression is likely also different in different species; but what triggers cells to enter one pathway and not another and how each archaeocyte cell type can be identified based on this gene knowledge are new challenges. Whereas molecular data provide a powerful new tool for interpreting sponge form and function, because sponges are suspension feeders, their body plan and physiology are very much dependent on their physical environment, and in particular on flow. Therefore, in order to integrate new knowledge of molecular data into a better understanding the sponge body plan, it is important to use an organismal approach. In this chapter, we give an account of sponge body organization as it relates to the physiology of the sponge in light of new molecular data. We focus, in particular, on the structure of sponge tissues and review descriptive as

  9. Policy for prevention of a retained sponge after vaginal delivery.

    PubMed

    Garry, David J; Asanjarani, Sandra; Geiss, Donna M

    2012-01-01

    Background. Policies for sponge count are not routine practice in most labor and delivery rooms. Ignored or hidden retained vaginal foreign bodies has potentially significant health care morbidity. Case. This was a case of a retained vaginal sponge following an uncomplicated spontaneous vaginal delivery. Delivery room policy resulted in the discovery of the sponge on X-ray when an incorrect sponge count occurred and physical exam did not find the sponge. Conclusion. This emphasizes the use of protocols to enhance patient safety and prevent medical error. PMID:22312370

  10. Policy for Prevention of a Retained Sponge after Vaginal Delivery

    PubMed Central

    Garry, David J.; Asanjarani, Sandra; Geiss, Donna M.

    2012-01-01

    Background. Policies for sponge count are not routine practice in most labor and delivery rooms. Ignored or hidden retained vaginal foreign bodies has potentially significant health care morbidity. Case. This was a case of a retained vaginal sponge following an uncomplicated spontaneous vaginal delivery. Delivery room policy resulted in the discovery of the sponge on X-ray when an incorrect sponge count occurred and physical exam did not find the sponge. Conclusion. This emphasizes the use of protocols to enhance patient safety and prevent medical error. PMID:22312370

  11. Picrosirius red staining: a useful tool to appraise collagen networks in normal and pathological tissues.

    PubMed

    Lattouf, Raed; Younes, Ronald; Lutomski, Didier; Naaman, Nada; Godeau, Gaston; Senni, Karim; Changotade, Sylvie

    2014-10-01

    Specific staining of the extracellular matrix components is especially helpful in studying tissue remodeling, particularly in the case of connective tissue pathologies. As developed by Junqueira and colleagues in 1979, specific staining by Picrosirius red is one of the most important stains to study collagen networks in different tissues. Under polarized light, collagen bundles appear green, red or yellow, and are easily differentiated from the black background, thus allowing for quantitative morphometric analysis. As Junqueira and colleagues point out, many studies use color staining to differentiate collagen bundles and to specify collagen types, yet other studies report that polarized colors only reflect fiber thickness and packing. Using a simple histological example, our study illustrates the inability of Picrosirius red staining to differentiate collagen types, since the absorbed amount of polarized light by this dye strictly depends on the orientation of the collagen bundles. PMID:25023614

  12. An evaluation of sterilization of endodontic instruments in artificial sponges.

    PubMed

    Vélez, A E; Thomas, D D; del Río, C E

    1998-01-01

    The ability to sterilize endodontic files inserted into synthetic sponges was tested. Sponges were subjected to 5 cycles of either dry heat (Driclave) or steam under pressure (autoclave) sterilization. Sterilization was corroborated by microbiological tests. The sponges and files were pre-sterilized separately using steam under pressure. One hundred eighty files contaminated with Bacillus stearothermophilus spores (experimental and positive control) and 60 noncontaminated files (negative control), were inserted into 60 sponges. After each cycle, each file and a portion of sponge surrounding the file were transferred aseptically to tubes containing trypticase soy broth culture medium for bacteriological analysis. None of the tubes containing files and portions of sponges that were subjected to autoclave grew Bacillus stearothermophilus spores. Two of 60 (3.33%) of the tubes that were subjected to sterilization by Driclave demonstrated bacterial growth. Although the sponges tolerated the dry heat cycles well physically, sterilization was achieved in only 96.67% of the cases. PMID:9487869

  13. Schlieren photography to study sound interaction with highly absorbing materials.

    PubMed

    Declercq, Nico F; Degrieck, Joris; Leroy, Oswald

    2005-06-01

    Strong absorption of sound is often caused by the conversion of sound energy into heat. When this happens, it is not possible to study the interaction of sound with the absorbing material by means of reflected sound characteristics, because there is no reflected sound. Detecting for example the distance that sound travels in a strongly absorbing material, can be done by heat detection systems. However, the presence of temperature detectors in such materials interferes with the sound field and is therefore not really suitable. Infrared measurements are a possible option. Another option is the use of Schlieren photography for simultaneous visualization of sound and heat. This technique is briefly outlined with a 3 MHz sound beam incident on a highly absorbing sponge. PMID:15950023

  14. Genetic disorders of collagen.

    PubMed Central

    Tsipouras, P; Ramirez, F

    1987-01-01

    Osteogenesis imperfecta, Ehlers-Danlos syndrome, and Marfan syndrome form a group of genetic disorders of connective tissue. These disorders exhibit remarkable clinical heterogeneity which reflects their underlying biochemical and molecular differences. Defects in collagen types I and III have been found in all three syndromes. PMID:3543367

  15. Collagen and injectable fillers.

    PubMed

    Cheng, Jacqueline T; Perkins, Stephen W; Hamilton, Mark M

    2002-02-01

    Soft tissue augmentation of facial rhytids, scars, and deformities is a frequently performed office procedure. This article reviews the available biologic (collagen, Dermalogen, Autologen, Isolagen, autologous fat, Fibrel, hyaluronic acid derivatives, particulate fascia lata, micronized Alloderm) and alloplastic (silicone, Bioplastique, and Artecoll) soft tissue injectable fillers. PMID:11781208

  16. Collagen hydrolysate based collagen/hydroxyapatite composite materials

    NASA Astrophysics Data System (ADS)

    Ficai, Anton; Albu, Madalina Georgiana; Birsan, Mihaela; Sonmez, Maria; Ficai, Denisa; Trandafir, Viorica; Andronescu, Ecaterina

    2013-04-01

    The aim of this study was to study the influence of collagen hydrolysate (HAS) on the formation of ternary collagen-hydrolysate/hydroxyapatite composite materials (COLL-HAS/HA). During the precipitation process of HA, a large amount of brushite is resulted at pH = 7 but, practically pure HA is obtained at pH ⩾ 8. The FTIR data reveal the duplication of the most important collagen absorption bands due to the presence of the collagen hydrolysate. The presence of collagen hydrolysate is beneficial for the management of bone and joint disorders such as osteoarthritis and osteoporosis.

  17. Plant-Derived Human Collagen Scaffolds for Skin Tissue Engineering

    PubMed Central

    Willard, James J.; Drexler, Jason W.; Das, Amitava; Roy, Sashwati; Shilo, Shani; Shoseyov, Oded

    2013-01-01

    Tissue engineering scaffolds are commonly formed using proteins extracted from animal tissues, such as bovine hide. Risks associated with the use of these materials include hypersensitivity and pathogenic contamination. Human-derived proteins lower the risk of hypersensitivity, but possess the risk of disease transmission. Methods engineering recombinant human proteins using plant material provide an alternate source of these materials without the risk of disease transmission or concerns regarding variability. To investigate the utility of plant-derived human collagen (PDHC) in the development of engineered skin (ES), PDHC and bovine hide collagen were formed into tissue engineering scaffolds using electrospinning or freeze-drying. Both raw materials were easily formed into two common scaffold types, electrospun nonwoven scaffolds and lyophilized sponges, with similar architectures. The processing time, however, was significantly lower with PDHC. PDHC scaffolds supported primary human cell attachment and proliferation at an equivalent or higher level than the bovine material. Interleukin-1 beta production was significantly lower when activated THP-1 macrophages where exposed to PDHC electrospun scaffolds compared to bovine collagen. Both materials promoted proper maturation and differentiation of ES. These data suggest that PDHC may provide a novel source of raw material for tissue engineering with low risk of allergic response or disease transmission. PMID:23298216

  18. Plant-derived human collagen scaffolds for skin tissue engineering.

    PubMed

    Willard, James J; Drexler, Jason W; Das, Amitava; Roy, Sashwati; Shilo, Shani; Shoseyov, Oded; Powell, Heather M

    2013-07-01

    Tissue engineering scaffolds are commonly formed using proteins extracted from animal tissues, such as bovine hide. Risks associated with the use of these materials include hypersensitivity and pathogenic contamination. Human-derived proteins lower the risk of hypersensitivity, but possess the risk of disease transmission. Methods engineering recombinant human proteins using plant material provide an alternate source of these materials without the risk of disease transmission or concerns regarding variability. To investigate the utility of plant-derived human collagen (PDHC) in the development of engineered skin (ES), PDHC and bovine hide collagen were formed into tissue engineering scaffolds using electrospinning or freeze-drying. Both raw materials were easily formed into two common scaffold types, electrospun nonwoven scaffolds and lyophilized sponges, with similar architectures. The processing time, however, was significantly lower with PDHC. PDHC scaffolds supported primary human cell attachment and proliferation at an equivalent or higher level than the bovine material. Interleukin-1 beta production was significantly lower when activated THP-1 macrophages where exposed to PDHC electrospun scaffolds compared to bovine collagen. Both materials promoted proper maturation and differentiation of ES. These data suggest that PDHC may provide a novel source of raw material for tissue engineering with low risk of allergic response or disease transmission. PMID:23298216

  19. Sponging up metals: bacteria associated with the marine sponge Spongia officinalis.

    PubMed

    Bauvais, Cléa; Zirah, Séverine; Piette, Laurie; Chaspoul, Florence; Domart-Coulon, Isabelle; Chapon, Virginie; Gallice, Philippe; Rebuffat, Sylvie; Pérez, Thierry; Bourguet-Kondracki, Marie-Lise

    2015-03-01

    The present study explored the bacteria of the sponge Spongia officinalis in a metal-polluted environment, using PCR-DGGE fingerprinting, culture-dependent approaches and in situ hybridization. The sponge samples collected over three consecutive years in the Western Mediterranean Sea contained high concentrations of zinc, nickel, lead and copper determined by ICP-MS. DGGE signatures indicated a sponge specific bacterial association and suggested spatial and temporal variations. The bacterial culturable fraction associated with S. officinalis and tolerant to heavy metals was isolated using metal-enriched microbiological media. The obtained 63 aerobic strains were phylogenetically affiliated to the phyla Proteobacteria, Actinobacteria, and Firmicutes. All isolates showed high tolerances to the selected heavy metals. The predominant genus Pseudovibrio was localized via CARD-FISH in the sponge surface tissue and validated as a sponge-associated epibiont. This study is the first step in understanding the potential involvement of the associated bacteria in sponge's tolerance to heavy metals. PMID:25575352

  20. Collagen esterification enhances the function and survival of pancreatic β cells in 2D and 3D culture systems

    SciTech Connect

    Ko, Jae Hyung; Kim, Yang Hee; Jeong, Seong Hee; Lee, Song; Park, Si-Nae; Shim, In Kyong; Kim, Song Cheol

    2015-08-07

    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. - Highlights: • We changed the collagen charge profile to a net positive charge by esterification. • Islets cultured on esterified collagen improved survival in both 2D and 3D culture. • Islets cultured on esterified collagen enhanced glucose-stimulated insulin release. • High levels of glucokinase mRNA may be associated with increased insulin release.

  1. Origin of Metazoa: sponges as living fossils.

    PubMed

    Müller, W E

    1998-01-01

    The phylogenetic position of the phylum Porifera (sponges) is at the base of the kingdom Metazoa. During the past few years not only rDNA sequences but--and this was a major advance--even cDNAs/genes have been isolated and characterized from sponges, especially from the marine demosponge Geodia cydonium, which code for proteins. The analyses of their deduced amino acid sequences allowed a molecular biological approach to solve the problem of monophyly of Metazoa. Molecules of the extracellular matrix/basal lamina, with the integrin receptor, fibronectin, and galectin as prominent examples, cell-surface receptors (tyrosine kinase receptor), elements of sensory systems (crystallin, metabotropic glutamate receptor), and homologs/modules of an immune system (immunoglobulin like molecules, scavenger receptor cysteine-rich, and short consensus repeats, rhesus system) classify the Porifera as true Metazoa. As living fossils, provided with simple, primordial molecules allowing cell-cell and cell-matrix adhesion as well as processes of signal transduction as known in a more complex manner from higher Metazoa, they also show peculiarities not known in other metazoan phyla. Tissues of sponges are rich in telomerase activity, suggesting a high plasticity in the determination of cell lineages. It is concluded that molecular biological studies with sponges as model will not only help to understand the evolution of Protoctista to Metazoa but also the complex, hierarchial regulatory network of cells in higher Metazoa. PMID:9484707

  2. Composition for absorbing hydrogen

    DOEpatents

    Heung, L.K.; Wicks, G.G.; Enz, G.L.

    1995-05-02

    A hydrogen absorbing composition is described. The composition comprises a porous glass matrix, made by a sol-gel process, having a hydrogen-absorbing material dispersed throughout the matrix. A sol, made from tetraethyl orthosilicate, is mixed with a hydrogen-absorbing material and solidified to form a porous glass matrix with the hydrogen-absorbing material dispersed uniformly throughout the matrix. The glass matrix has pores large enough to allow gases having hydrogen to pass through the matrix, yet small enough to hold the particles dispersed within the matrix so that the hydrogen-absorbing particles are not released during repeated hydrogen absorption/desorption cycles.

  3. Composition for absorbing hydrogen

    DOEpatents

    Heung, Leung K.; Wicks, George G.; Enz, Glenn L.

    1995-01-01

    A hydrogen absorbing composition. The composition comprises a porous glass matrix, made by a sol-gel process, having a hydrogen-absorbing material dispersed throughout the matrix. A sol, made from tetraethyl orthosilicate, is mixed with a hydrogen-absorbing material and solidified to form a porous glass matrix with the hydrogen-absorbing material dispersed uniformly throughout the matrix. The glass matrix has pores large enough to allow gases having hydrogen to pass through the matrix, yet small enough to hold the particles dispersed within the matrix so that the hydrogen-absorbing particles are not released during repeated hydrogen absorption/desorption cycles.

  4. Antiviral Lead Compounds from Marine Sponges

    PubMed Central

    Sagar, Sunil; Kaur, Mandeep; Minneman, Kenneth P.

    2010-01-01

    Marine sponges are currently one of the richest sources of pharmacologically active compounds found in the marine environment. These bioactive molecules are often secondary metabolites, whose main function is to enable and/or modulate cellular communication and defense. They are usually produced by functional enzyme clusters in sponges and/or their associated symbiotic microorganisms. Natural product lead compounds from sponges have often been found to be promising pharmaceutical agents. Several of them have successfully been approved as antiviral agents for clinical use or have been advanced to the late stages of clinical trials. Most of these drugs are used for the treatment of human immunodeficiency virus (HIV) and herpes simplex virus (HSV). The most important antiviral lead of marine origin reported thus far is nucleoside Ara-A (vidarabine) isolated from sponge Tethya crypta. It inhibits viral DNA polymerase and DNA synthesis of herpes, vaccinica and varicella zoster viruses. However due to the discovery of new types of viruses and emergence of drug resistant strains, it is necessary to develop new antiviral lead compounds continuously. Several sponge derived antiviral lead compounds which are hopedto be developed as future drugs are discussed in this review. Supply problems are usually the major bottleneck to the development of these compounds as drugs during clinical trials. However advances in the field of metagenomics and high throughput microbial cultivation has raised the possibility that these techniques could lead to the cost-effective large scale production of such compounds. Perspectives on biotechnological methods with respect to marine drug development are also discussed. PMID:21116410

  5. Sponge-Associated Microorganisms: Evolution, Ecology, and Biotechnological Potential†

    PubMed Central

    Taylor, Michael W.; Radax, Regina; Steger, Doris; Wagner, Michael

    2007-01-01

    Summary: Marine sponges often contain diverse and abundant microbial communities, including bacteria, archaea, microalgae, and fungi. In some cases, these microbial associates comprise as much as 40% of the sponge volume and can contribute significantly to host metabolism (e.g., via photosynthesis or nitrogen fixation). We review in detail the diversity of microbes associated with sponges, including extensive 16S rRNA-based phylogenetic analyses which support the previously suggested existence of a sponge-specific microbiota. These analyses provide a suitable vantage point from which to consider the potential evolutionary and ecological ramifications of these widespread, sponge-specific microorganisms. Subsequently, we examine the ecology of sponge-microbe associations, including the establishment and maintenance of these sometimes intimate partnerships, the varied nature of the interactions (ranging from mutualism to host-pathogen relationships), and the broad-scale patterns of symbiont distribution. The ecological and evolutionary importance of sponge-microbe associations is mirrored by their enormous biotechnological potential: marine sponges are among the animal kingdom's most prolific producers of bioactive metabolites, and in at least some cases, the compounds are of microbial rather than sponge origin. We review the status of this important field, outlining the various approaches (e.g., cultivation, cell separation, and metagenomics) which have been employed to access the chemical wealth of sponge-microbe associations. PMID:17554047

  6. Epizoic zoanthids reduce pumping in two Caribbean vase sponges

    NASA Astrophysics Data System (ADS)

    Lewis, T. B.; Finelli, C. M.

    2015-03-01

    Sponges are common sessile benthic suspension feeders that play a critical role in carbon and nitrogen cycling within reef ecosystems via their filtration capabilities. Due to the contribution of sponges in benthic-pelagic coupling, it is critical to assess factors that may affect their role in the healthy function of coral reefs. Several factors can influence the rate at which an individual sponge pumps water, including body size, environmental conditions, mechanical blockage, and reduction of inhalant pores (ostia). Symbiotic zoanthid colonization is a common occurrence on Caribbean sponges, and the presence of zoanthids on the surface of a sponge may occlude or displace the inhalant ostia. We quantified pumping rates of the giant barrel sponge, Xestospongia muta ( N = 22 uncolonized, 37 colonized) and the common vase sponge, Niphates digitalis ( N = 21 uncolonized, 17 colonized), with and without zoanthid symbionts, Parazoanthus catenularis and Parazoanthus parasiticus, respectively. For X. muta, biovolume-normalized pumping rates of individuals colonized by zoanthids were approximately 75 % lower than those of uncolonized sponges. Moreover, colonization with zoanthids was related to a difference in morphology relative to uncolonized individuals: Colonized sponges exhibited an osculum area to biovolume ratio that was nearly 65 % less than uncolonized sponges. In contrast, the presence of zoanthids on N. digitalis resulted in only a marginal decrease in pumping rates and no detectable difference in morphology. The difference in zoanthid effects between X. muta and N. digitalis is likely due to the differences in wall thickness and architecture between the two species. The probable cause of reduced pumping in affected sponges is occupation of the sponge surface that leads to blockage or displacement of inhalant ostia. To partially test this hypothesis, zoanthid colonization on specimens of X. muta was simulated by wrapping sponges with plastic mesh of varying

  7. Collagen Homeostasis and Metabolism.

    PubMed

    Magnusson, S Peter; Heinemeier, Katja M; Kjaer, Michael

    2016-01-01

    The musculoskeletal system and its collagen rich tissue is important for ensuring architecture of skeletal muscle, energy storage in tendon and ligaments, joint surface protection, and for ensuring the transfer of muscular forces into resulting limb movement. Structure of tendon is stable and the metabolic activity is low, but mechanical loading and subsequent mechanotransduction and molecular anabolic signaling can result in some adaptation of the tendon especially during youth and adolescence. Within short time, tendon will get stiffer with training and lack of mechanical tissue loading through inactivity or immobilization of the human body will conversely result in a dramatic loss in tendon stiffness and collagen synthesis. This illustrates the importance of regular mechanical load in order to preserve the stabilizing role of the connective tissue for the overall function of the musculoskeletal system in both daily activity and exercise. Adaptive responses may vary along the tendon, and differ between mid-substance and insertional areas of the tendon. PMID:27535245

  8. Modelling Absorbent Phenomena of Absorbent Structure

    NASA Astrophysics Data System (ADS)

    Sayeb, S.; Ladhari, N.; Ben Hassen, M.; Sakli, F.

    Absorption, retention and strike through time, as evaluating criteria of absorbent structures quality were studied. Determination of influent parameters on these criteria were realized by using the design method of experimental sets. In this study, the studied parameters are: Super absorbent polymer (SAP)/fluff ratio, compression and the porosity of the non woven used as a cover stock. Absorption capacity and retention are mostly influenced by SAP/fluff ratio. However, strike through time is affected by compression. Thus, a modelling of these characteristics in function of the important parameter was established.

  9. Methods for absorbing neutrons

    DOEpatents

    Guillen, Donna P.; Longhurst, Glen R.; Porter, Douglas L.; Parry, James R.

    2012-07-24

    A conduction cooled neutron absorber may include a metal matrix composite that comprises a metal having a thermal neutron cross-section of at least about 50 barns and a metal having a thermal conductivity of at least about 1 W/cmK. Apparatus for providing a neutron flux having a high fast-to-thermal neutron ratio may include a source of neutrons that produces fast neutrons and thermal neutrons. A neutron absorber positioned adjacent the neutron source absorbs at least some of the thermal neutrons so that a region adjacent the neutron absorber has a fast-to-thermal neutron ratio of at least about 15. A coolant in thermal contact with the neutron absorber removes heat from the neutron absorber.

  10. Externally tuned vibration absorber

    DOEpatents

    Vincent, Ronald J.

    1987-09-22

    A vibration absorber unit or units are mounted on the exterior housing of a hydraulic drive system of the type that is powered from a pressure wave generated, e.g., by a Stirling engine. The hydraulic drive system employs a piston which is hydraulically driven to oscillate in a direction perpendicular to the axis of the hydraulic drive system. The vibration absorbers each include a spring or other resilient member having one side affixed to the housing and another side to which an absorber mass is affixed. In a preferred embodiment, a pair of vibration absorbers is employed, each absorber being formed of a pair of leaf spring assemblies, between which the absorber mass is suspended.

  11. Modeling the Distribution of Geodia Sponges and Sponge Grounds in the Northwest Atlantic

    PubMed Central

    Knudby, Anders; Kenchington, Ellen; Murillo, Francisco Javier

    2013-01-01

    Deep-sea sponge grounds provide structurally complex habitat for fish and invertebrates and enhance local biodiversity. They are also vulnerable to bottom-contact fisheries and prime candidates for Vulnerable Marine Ecosystem designation and related conservation action. This study uses species distribution modeling, based on presence and absence observations of Geodia spp. and sponge grounds derived from research trawl catches, as well as spatially continuous data on the physical and biological ocean environment derived from satellite data and oceanographic models, to model the distribution of Geodia sponges and sponge grounds in the Northwest Atlantic. Most models produce excellent fits with validation data although fits are reduced when models are extrapolated to new areas, especially when oceanographic regimes differ between areas. Depth and minimum bottom salinity were important predictors in most models, and a Geodia spp. minimum bottom salinity tolerance threshold in the 34.3-34.8 psu range was hypothesized on the basis of model structure. The models indicated two currently unsampled regions within the study area, the deeper parts of Baffin Bay and the Newfoundland and Labrador slopes, where future sponge grounds are most likely to be found. PMID:24324768

  12. Heterogeneity of collagens in rabbit cornea: type VI collagen

    SciTech Connect

    Cintron, C.; Hong, B.S.

    1988-05-01

    Normal adult rabbit corneas were digested with 5% pepsin and their collagens extracted with acetic acid. Collagen extracts were fractionated by differential salt precipitation. The 2.5 M NaCl fraction was then redissolved with tris buffer and precipitated with sodium acetate. The precipitate contained a high-molecular-weight disulfide-bonded aggregate which, upon reduction with mercaptoethanol, was converted into three distinct polypeptides having molecular weights between 45 and 66 Kd. These physical characteristics, together with the susceptibility of these polypeptides to collagenase and their amino acid composition, identified the high molecular weight aggregate as type VI collagen. Corneas from neonate rabbits and adult corneas containing 2-week-old scars were organ cultured in the presence of (/sup 14/C) glycine to incorporate radiolabel into collagen. Tissues were digested with 0.02% pepsin and their collagens extracted with formic acid. The total radioactivity of the extracts and tissue residues was determined before the collagens were separated by SDS-polyacrylamide slab gel electrophoresis. Radioactive collagen polypeptides bands were then stained with Coomassie blue, processed for fluorography, and analyzed by densitometry. The results show that: (1) type VI collagen is synthesized by neonate corneas and healing adult corneas; (2) it is not readily solubilized from either corneal tissue by 0.02% pepsin digestion and formic acid extraction; and (3) the proportion of type VI collagen deposited in scar tissue is markedly lower than that found in neonate corneas.

  13. Heterogeneity of collagens in rabbit cornea: type III collagen

    SciTech Connect

    Cintron, C.; Hong, B.S.; Covington, H.I.; Macarak, E.J.

    1988-05-01

    Whole neonate rabbit corneas and adult corneas containing 2-week-old scars were incubated in the presence of (/sup 14/C) glycine. Radiolabeled collagen extracted from the corneas and scar tissue were analyzed by sodium dodecylsulfate/polyacrylamide gel electrophoresis and fluorography to determine the types and relative quantity of collagen polypeptides present and synthesized by these tissues. In addition to other collagen types, type III was found in both neonate cornea and scar tissue from adult cornea, albeit in relatively small quantities. Type III collagen in normal cornea was associated with the residue after pepsin digestion and formic acid extraction of the tissue, and the same type of collagen was extracted from scar tissue after similar treatment. Type III collagen-specific monoclonal antibody bound to developing normal corneas and healing adult tissue sections, as determined by immunofluorescence. Antibody binding was localized to the endothelium and growing Descemet's membrane in fetal and neonate corneas, and restricted to the most posterior region of the corneal scar tissue. Although monoclonal antibody to keratan sulfate, used as a marker for stromal fibroblasts, bound to most of the scar tissue, the antibody failed to bind to the posterior scar tissue positive for type III collagen. We conclude that endothelial cells from fetal and neonate rabbit cornea and endothelium-derived fibroblasts from healing wounds of adult cornea synthesize and deposit type III collagen. Moreover, this collagen appears to be incorporated into the growing Descemet's membrane of normal corneas and narrow posterior portion of the scar tissue.

  14. Complex nitrogen cycling in the sponge Geodia barretti.

    PubMed

    Hoffmann, Friederike; Radax, Regina; Woebken, Dagmar; Holtappels, Moritz; Lavik, Gaute; Rapp, Hans Tore; Schläppy, Marie-Lise; Schleper, Christa; Kuypers, Marcel M M

    2009-09-01

    Marine sponges constitute major parts of coral reefs and deep-water communities. They often harbour high amounts of phylogenetically and physiologically diverse microbes, which are so far poorly characterized. Many of these sponges regulate their internal oxygen concentration by modulating their ventilation behaviour providing a suitable habitat for both aerobic and anaerobic microbes. In the present study, both aerobic (nitrification) and anaerobic (denitrification, anammox) microbial processes of the nitrogen cycle were quantified in the sponge Geodia barretti and possible involved microbes were identified by molecular techniques. Nitrification rates of 566 nmol N cm(-3) sponge day(-1) were obtained when monitoring the production of nitrite and nitrate. In support of this finding, ammonia-oxidizing Archaea (crenarchaeotes) were found by amplification of the amoA gene, and nitrite-oxidizing bacteria of the genus Nitrospira were detected based on rRNA gene analyses. Incubation experiments with stable isotopes ((15)NO(3)(-) and (15)NH(4)(+)) revealed denitrification and anaerobic ammonium oxidation (anammox) rates of 92 nmol N cm(-3) sponge day(-1) and 3 nmol N cm(-3) sponge day(-1) respectively. Accordingly, sequences closely related to 'Candidatus Scalindua sorokinii' and 'Candidatus Scalindua brodae' were detected in 16S rRNA gene libraries. The amplification of the nirS gene revealed the presence of denitrifiers, likely belonging to the Betaproteobacteria. This is the first proof of anammox and denitrification in the same animal host, and the first proof of anammox and denitrification in sponges. The close and complex interactions of aerobic, anaerobic, autotrophic and heterotrophic microbial processes are fuelled by metabolic waste products of the sponge host, and enable efficient utilization and recirculation of nutrients within the sponge-microbe system. Since denitrification and anammox remove inorganic nitrogen from the environment, sponges may function as

  15. Sponge-rhodolith interactions in a subtropical estuarine system

    NASA Astrophysics Data System (ADS)

    Ávila, Enrique; Riosmena-Rodríguez, Rafael; Hinojosa-Arango, Gustavo

    2013-06-01

    The interactions between sponges and red macroalgae have been widely documented in tropical and subtropical environments worldwide, and many of them have been documented as mutualistic associations. Sponges, however, have also been frequently described as part of the associated fauna of rhodolith habitats (aggregations of free-living non-geniculated coralline macroalgae). Nonetheless, the types of interaction they establish as well as the role of sponges in these habitats remain unknown. In this study, the associations between sponges and rhodoliths were investigated in an estuarine ecosystem of the Mexican Pacific based on qualitative and quantitative data. A total of 13 sponge species were identified in five newly discovered rhodolith beds dominated by the non-geniculate coralline macroalga Lithophyllum margaritae. The sponge assemblages were strongly restricted to rhodolith habitats. The best predictor of sponge abundance (from 5.1 to 51.7 ind m-2) and species richness (from 2.6 to 6.1 sponge species m-2) was the rhodolith density rather than other population descriptors assessed (e.g., average size, branch density and sphericity). The identified sponges included a variety of forms: massive (46 %), encrusting (23 %), excavating (15 %), cushion-shape (8 %) and digitate (8 %). Moreover, more than 50 % of sponge species recorded (mainly massive and encrusting forms) were frequently found overgrowing and binding rhodoliths. Halichondria cf. semitubulosa and Mycale cecilia were the most common binding agents; these species bind an average of 3.1 and 6.6 rhodoliths per sponge individual, respectively. These findings reveal the importance of rhodoliths as habitat forming species, since these seaweed beds notably increased the substrate complexity in soft bottom environments. In addition, the relatively high abundance of sponges and their capability to bind rhodoliths suggest that these associated organisms could have an important contribution to rhodolith bed stability.

  16. Bacterial uptake by the marine sponge Aplysina aerophoba.

    PubMed

    Wehrl, Markus; Steinert, Michael; Hentschel, Ute

    2007-02-01

    Sponges (Porifera) are filter feeders that take up microorganisms from seawater and digest them by phagocytosis. At the same time, many sponges are known to harbor massive consortia of symbiotic microorganisms, which are phylogenetically distinct from those in seawater, within the mesohyl matrix. In the present study, feeding experiments were performed to investigate whether phylogenetically different bacterial isolates, hereafter termed "food bacteria," microbial seawater consortia, and sponge symbiont consortia are taken up and processed differently by the host sponge. Aplysina aerophoba retained high numbers of bacterial isolates and microbial seawater consortia with rates of up to 2.76 x 10(6) bacteria (g sponge wet weight)(-1) h(-1), whereas the retention of sponge symbionts was lower by nearly two orders of magnitude [5.37 x 10(4) bacteria (g sponge wet weight)(-1) h(-1)]. In order to visualize the processing of a food bacterium within sponge tissues, the green fluorescent protein-labeled Vibrio strain MMW1, which had originally been isolated from A. aerophoba, was constructed. Incubation of this strain with A. aerophoba and subsequent visualization in tissue cryosections showed its presence in the choanocytes and/or endopinacocytes lining the canals but, unlike latex beads, not in deeper regions of the mesohyl, which suggests digestion of the bacteria upon contact with the host. Denaturing gradient gel electrophoresis (DGGE) was performed on the incubation seawater to monitor the changes in phylogenetic composition after incubation of the sponge with either seawater or sponge symbiont consortia. However, the DGGE experiment provided no evidence for selective processing of individual lineages by the host sponge. In conclusion, this study extends early studies by Wilkinson et al. (Proc R Soc London B 220:519-528, 1984) that sponges, here A. aerophoba, are able to differentiate between food bacteria and their own bacterial symbionts. PMID:17265004

  17. Deep phylogeny and evolution of sponges (phylum Porifera).

    PubMed

    Wörheide, G; Dohrmann, M; Erpenbeck, D; Larroux, C; Maldonado, M; Voigt, O; Borchiellini, C; Lavrov, D V

    2012-01-01

    Sponges (phylum Porifera) are a diverse taxon of benthic aquatic animals of great ecological, commercial, and biopharmaceutical importance. They are arguably the earliest-branching metazoan taxon, and therefore, they have great significance in the reconstruction of early metazoan evolution. Yet, the phylogeny and systematics of sponges are to some extent still unresolved, and there is an on-going debate about the exact branching pattern of their main clades and their relationships to the other non-bilaterian animals. Here, we review the current state of the deep phylogeny of sponges. Several studies have suggested that sponges are paraphyletic. However, based on recent phylogenomic analyses, we suggest that the phylum Porifera could well be monophyletic, in accordance with cladistic analyses based on morphology. This finding has many implications for the evolutionary interpretation of early animal traits and sponge development. We further review the contribution that mitochondrial genes and genomes have made to sponge phylogenetics and explore the current state of the molecular phylogenies of the four main sponge lineages (Classes), that is, Demospongiae, Hexactinellida, Calcarea, and Homoscleromorpha, in detail. While classical systematic systems are largely congruent with molecular phylogenies in the class Hexactinellida and in certain parts of Demospongiae and Homoscleromorpha, the high degree of incongruence in the class Calcarea still represents a challenge. We highlight future areas of research to fill existing gaps in our knowledge. By reviewing sponge development in an evolutionary and phylogenetic context, we support previous suggestions that sponge larvae share traits and complexity with eumetazoans and that the simple sedentary adult lifestyle of sponges probably reflects some degree of secondary simplification. In summary, while deep sponge phylogenetics has made many advances in the past years, considerable efforts are still required to achieve a

  18. Local Application of Ibandronate/Gelatin Sponge Improves Osteotomy Healing in Rabbits

    PubMed Central

    Xia, Zhidao; Liu, Yueju; Peggrem, Shaun; Geng, Tao; Yang, Zhaoxu; Li, Han; Xu, Bin; Zhang, Chi; Triffitt, James T.; Zhang, Yingze

    2015-01-01

    Delayed healing or non-union of skeletal fractures are common clinical complications. Ibandronate is a highly potent anti-catabolic reagent used for treatment of osteopenia and fracture prevention. We hypothesized that local application of ibandronate after fracture fixation may improve and sustain callus formation and therefore prevent delayed healing or non-union. This study tested the effect of local application of an ibandronate/gelatin sponge composite on osteotomy healing. A right-side distal-femoral osteotomy was created surgically, with fixation using a k-wire, in forty adult male rabbits. The animals were divided into four groups of ten animals and treated by: (i) intravenous injection of normal saline (Control); (ii) local implantation of absorbable gelatin sponge (GS); (iii) local implantation of absorbable GS containing ibandronate (IB+GS), and (iv) intravenous injection of ibandronate (IB i.v.). At two and four weeks the affected femora were harvested for X-ray photography, computed tomography (CT), biomechanical testing and histopathology. At both time-points the results showed that the calluses in both the ibandronate-treated groups, but especially in the IB+GS group, were significantly larger than in the control and GS groups. At four weeks the cross sectional area (CSA) and mechanical test results of ultimate load and energy in the IB+GS group were significantly higher than in other groups. Histological procedures showed a significant reduction in osteoclast numbers in the IB+GS and IB i.v. groups at day 14. The results indicate that local application of an ibandronate/gelatin sponge biomaterial improved early osteotomy healing after surgical fixation and suggest that such treatment may be a valuable local therapy to enhance fracture repair and potentially prevent delayed or non-union. PMID:25951178

  19. Tactile texture and friction of soft sponge surfaces.

    PubMed

    Takahashi, Akira; Suzuki, Makoto; Imai, Yumi; Nonomura, Yoshimune

    2015-06-01

    We evaluated the tactile texture and frictional properties of five soft sponges with various cell sizes. The frictional forces were measured by a friction meter containing a contact probe with human-finger-like geometry and mechanical properties. When the subjects touched these sponges with their fingers, hard-textured sponges were deemed unpleasant. This tactile feeling changed with friction factors including friction coefficients, their temporal patterns, as well as mechanical and shape factors. These findings provide useful information on how to control the tactile textures of various sponges. PMID:25884490

  20. Arterial calcification: Conscripted by collagen

    NASA Astrophysics Data System (ADS)

    Miller, Jordan D.

    2016-03-01

    In atherosclerotic plaques, patterns of calcification -- which have profound implications for plaque stability and vulnerability to rupture -- are determined by the collagen's content and patterning throughout the plaque.

  1. Marine Sponges as a Drug Treasure.

    PubMed

    Anjum, Komal; Abbas, Syed Qamar; Shah, Sayed Asmat Ali; Akhter, Najeeb; Batool, Sundas; Hassan, Syed Shams Ul

    2016-07-01

    Marine sponges have been considered as a drug treasure house with respect to great potential regarding their secondary metabolites. Most of the studies have been conducted on sponge's derived compounds to examine its pharmacological properties. Such compounds proved to have antibacterial, antiviral, antifungal, antimalarial, antitumor, immunosuppressive, and cardiovascular activity. Although, the mode of action of many compounds by which they interfere with human pathogenesis have not been clear till now, in this review not only the capability of the medicinal substances have been examined in vitro and in vivo against serious pathogenic microbes but, the mode of actions of medicinal compounds were explained with diagrammatic illustrations. This knowledge is one of the basic components to be known especially for transforming medicinal molecules to medicines. Sponges produce a different kind of chemical substances with numerous carbon skeletons, which have been found to be the main component interfering with human pathogenesis at different sites. The fact that different diseases have the capability to fight at different sites inside the body can increase the chances to produce targeted medicines. PMID:27350338

  2. The Sponge Implant Model of Angiogenesis.

    PubMed

    Andrade, Silvia Passos; Ferreira, Mônica Alves Neves Diniz

    2016-01-01

    The host response observed after the application of an appropriate stimulus, such as mechanical injury or injection of neoplastic or normal tissue implants, has allowed the cataloging of a number of molecules and cells involved in the vascularization of normal repair or neoplastic tissue. Implantation of sponge matrices has been adopted as a model for the accurate quantification of angiogenic and fibrogenic responses, as they may occur during wound healing, in vivo. Such implants are particularly useful because they offer scope for modulating the environment within which angiogenesis occurs. Sponge implantation model has been optimized and adapted to characterize essential components and their roles in blood vessels formation in a variety of physiological and pathological conditions. As a direct consequence of advances in genetic manipulation, mouse models (i.e., knockouts, SCID, nude) have provided resources to delineate the mechanisms regulating the healing associated with implants. Here we outline the usefulness of the sponge implant model of angiogenesis and detailed description of the methodology. PMID:27172965

  3. Optimization of biodegradable sponges as controlled release drug matrices. I. Effect of moisture level on chitosan sponge mechanical properties.

    PubMed

    Foda, Nagwa H; El-laithy, Hanan M; Tadros, Mina I

    2004-04-01

    Cross-linked chitosan sponges as controlled release drug carrier systems were developed. Tramadol hydrochloride, a centrally acting analgesic, was used as a model drug. The sponges were prepared by freeze-drying 1.25% and 2.5% (w/w) high and low M.wt. chitosan solutions, respectively, using glutaraldehyde as a cross-linking agent. The hardness of the prepared sponges was a function of glutaraldehyde concentration and volume where the optimum concentration that offered accepted sponge consistency was 5%. Below or above 5%, very soft or very hard and brittle sponges were obtained, respectively. The determined drug content in the prepared sponges was uniform and did not deviate markedly from the calculated amount. Scanning electron microscopy (SEM) was used to characterize the internal structures of the sponges. The SEM photos revealed that cross-linked high M.wt. chitosan sponges have larger size surface pores that form connections (channels) with the interior of the sponge than cross-linked low M.wt. ones. Moreover, crystals of the incorporated Tramadol hydrochloride were detected on the lamellae and within pores in both chitosan sponges. Differences in pore size and dissolution medium uptake capacity were crucial factors for the more delayed drug release from cross-linked low M.wt. chitosan sponges over high M.wt. ones at pH 7.4. Kinetic analysis of the release data using linear regression followed the Higuchi diffusion model over 12 hours. Setting storage conditions at room temperature under 80-92% relative humidity resulted in soft, elastic, and compressible sponges. PMID:15132179

  4. Advanced neutron absorber materials

    DOEpatents

    Branagan, Daniel J.; Smolik, Galen R.

    2000-01-01

    A neutron absorbing material and method utilizing rare earth elements such as gadolinium, europium and samarium to form metallic glasses and/or noble base nano/microcrystalline materials, the neutron absorbing material having a combination of superior neutron capture cross sections coupled with enhanced resistance to corrosion, oxidation and leaching.

  5. Multispectral metamaterial absorber.

    PubMed

    Grant, J; McCrindle, I J H; Li, C; Cumming, D R S

    2014-03-01

    We present the simulation, implementation, and measurement of a multispectral metamaterial absorber (MSMMA) and show that we can realize a simple absorber structure that operates in the mid-IR and terahertz (THz) bands. By embedding an IR metamaterial absorber layer into a standard THz metamaterial absorber stack, a narrowband resonance is induced at a wavelength of 4.3 μm. This resonance is in addition to the THz metamaterial absorption resonance at 109 μm (2.75 THz). We demonstrate the inherent scalability and versatility of our MSMMA by describing a second device whereby the MM-induced IR absorption peak frequency is tuned by varying the IR absorber geometry. Such a MSMMA could be coupled with a suitable sensor and formed into a focal plane array, enabling multispectral imaging. PMID:24690713

  6. [Morphological tissue changes after the implantation of a biodegradable material on collagen basis].

    PubMed

    Maĭborodin, I V; Beregovoĭ, E A; Shevela, A I; Kuznetsova, I V; Barannik, M I; Manaev, A A; Maĭborodina, V I

    2013-01-01

    The objective of this study was to examine the peculiarities of tissue reactions during the degradation of "Collost" bioplastic material on the collagen basis with completely preserved fibrous structure, after its implantation into the bone tissue defect. The defect in bone tissue sized 1-2 mm x 3-5 mm was created in tibial condyle. The study was performed on 24 Wistar rats using light microscopic methods. The tissue reactions were studied at different time intervals (1, 2, 6 and 12 months) after the implantation of collagenic material. It was found that after the implantation, the material became impregnated with blood, and due to fibrin, densely adhered to the damaged tissues. Further, the cells were found to migrate along the blood clot into its depth from the surrounding tissues. These were primarily the fibroblasts which were located in a network of fibers and started to absorb collagen from a surrounding material and to synthesize new collagen. Gradually, the collagenic material became similar to a cell-containing network. The volume of the newly synthesized collagen increased, and after some time all the foreign material was absorbed by fibroblasts and replaced with connective tissue. After 1 year, a large "Collost" fragment was completely degraded and replaced by loose connective tissue. The implantation of a collagenic material did not stimulate the formation of a delimiting connective tissue capsule PMID:24707743

  7. Two distinct microbial communities revealed in the sponge Cinachyrella

    PubMed Central

    Cuvelier, Marie L.; Blake, Emily; Mulheron, Rebecca; McCarthy, Peter J.; Blackwelder, Patricia; Thurber, Rebecca L. Vega; Lopez, Jose V.

    2014-01-01

    Marine sponges are vital components of benthic and coral reef ecosystems, providing shelter and nutrition for many organisms. In addition, sponges act as an essential carbon and nutrient link between the pelagic and benthic environment by filtering large quantities of seawater. Many sponge species harbor a diverse microbial community (including Archaea, Bacteria and Eukaryotes), which can constitute up to 50% of the sponge biomass. Sponges of the genus Cinachyrella are common in Caribbean and Floridian reefs and their archaeal and bacterial microbiomes were explored here using 16S rRNA gene tag pyrosequencing. Cinachyrella specimens and seawater samples were collected from the same South Florida reef at two different times of year. In total, 639 OTUs (12 archaeal and 627 bacterial) belonging to 2 archaeal and 21 bacterial phyla were detected in the sponges. Based on their microbiomes, the six sponge samples formed two distinct groups, namely sponge group 1 (SG1) with lower diversity (Shannon-Weiner index: 3.73 ± 0.22) and SG2 with higher diversity (Shannon-Weiner index: 5.95 ± 0.25). Hosts' 28S rRNA gene sequences further confirmed that the sponge specimens were composed of two taxa closely related to Cinachyrella kuekenthalli. Both sponge groups were dominated by Proteobacteria, but Alphaproteobacteria were significantly more abundant in SG1. SG2 harbored many bacterial phyla (>1% of sequences) present in low abundance or below detection limits (<0.07%) in SG1 including: Acidobacteria, Chloroflexi, Gemmatimonadetes, Nitrospirae, PAUC34f, Poribacteria, and Verrucomicrobia. Furthermore, SG1 and SG2 only had 95 OTUs in common, representing 30.5 and 22.4% of SG1 and SG2's total OTUs, respectively. These results suggest that the sponge host may exert a pivotal influence on the nature and structure of the microbial community and may only be marginally affected by external environment parameters. PMID:25408689

  8. Phylogenetically and Spatially Close Marine Sponges Harbour Divergent Bacterial Communities

    PubMed Central

    Hardoim, Cristiane C. P.; Esteves, Ana I. S.; Pires, Francisco R.; Gonçalves, Jorge M. S.; Cox, Cymon J.; Xavier, Joana R.; Costa, Rodrigo

    2012-01-01

    Recent studies have unravelled the diversity of sponge-associated bacteria that may play essential roles in sponge health and metabolism. Nevertheless, our understanding of this microbiota remains limited to a few host species found in restricted geographical localities, and the extent to which the sponge host determines the composition of its own microbiome remains a matter of debate. We address bacterial abundance and diversity of two temperate marine sponges belonging to the Irciniidae family - Sarcotragus spinosulus and Ircinia variabilis – in the Northeast Atlantic. Epifluorescence microscopy revealed that S. spinosulus hosted significantly more prokaryotic cells than I. variabilis and that prokaryotic abundance in both species was about 4 orders of magnitude higher than in seawater. Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) profiles of S. spinosulus and I. variabilis differed markedly from each other – with higher number of ribotypes observed in S. spinosulus – and from those of seawater. Four PCR-DGGE bands, two specific to S. spinosulus, one specific to I. variabilis, and one present in both sponge species, affiliated with an uncultured sponge-specific phylogenetic cluster in the order Acidimicrobiales (Actinobacteria). Two PCR-DGGE bands present exclusively in S. spinosulus fingerprints affiliated with one sponge-specific phylogenetic cluster in the phylum Chloroflexi and with sponge-derived sequences in the order Chromatiales (Gammaproteobacteria), respectively. One Alphaproteobacteria band specific to S. spinosulus was placed in an uncultured sponge-specific phylogenetic cluster with a close relationship to the genus Rhodovulum. Our results confirm the hypothesized host-specific composition of bacterial communities between phylogenetically and spatially close sponge species in the Irciniidae family, with S. spinosulus displaying higher bacterial community diversity and distinctiveness than I. variabilis. These

  9. Two distinct microbial communities revealed in the sponge Cinachyrella.

    PubMed

    Cuvelier, Marie L; Blake, Emily; Mulheron, Rebecca; McCarthy, Peter J; Blackwelder, Patricia; Thurber, Rebecca L Vega; Lopez, Jose V

    2014-01-01

    Marine sponges are vital components of benthic and coral reef ecosystems, providing shelter and nutrition for many organisms. In addition, sponges act as an essential carbon and nutrient link between the pelagic and benthic environment by filtering large quantities of seawater. Many sponge species harbor a diverse microbial community (including Archaea, Bacteria and Eukaryotes), which can constitute up to 50% of the sponge biomass. Sponges of the genus Cinachyrella are common in Caribbean and Floridian reefs and their archaeal and bacterial microbiomes were explored here using 16S rRNA gene tag pyrosequencing. Cinachyrella specimens and seawater samples were collected from the same South Florida reef at two different times of year. In total, 639 OTUs (12 archaeal and 627 bacterial) belonging to 2 archaeal and 21 bacterial phyla were detected in the sponges. Based on their microbiomes, the six sponge samples formed two distinct groups, namely sponge group 1 (SG1) with lower diversity (Shannon-Weiner index: 3.73 ± 0.22) and SG2 with higher diversity (Shannon-Weiner index: 5.95 ± 0.25). Hosts' 28S rRNA gene sequences further confirmed that the sponge specimens were composed of two taxa closely related to Cinachyrella kuekenthalli. Both sponge groups were dominated by Proteobacteria, but Alphaproteobacteria were significantly more abundant in SG1. SG2 harbored many bacterial phyla (>1% of sequences) present in low abundance or below detection limits (<0.07%) in SG1 including: Acidobacteria, Chloroflexi, Gemmatimonadetes, Nitrospirae, PAUC34f, Poribacteria, and Verrucomicrobia. Furthermore, SG1 and SG2 only had 95 OTUs in common, representing 30.5 and 22.4% of SG1 and SG2's total OTUs, respectively. These results suggest that the sponge host may exert a pivotal influence on the nature and structure of the microbial community and may only be marginally affected by external environment parameters. PMID:25408689

  10. High-Surface-Area CO2 Sponge: High Performance CO2 Scrubbing Based on Hollow Fiber-Supported Designer Ionic Liquid Sponges

    SciTech Connect

    2010-09-01

    IMPACCT Project: The team from ORNL and Georgia Tech is developing a new technology that will act like a sponge, integrating a new, alcohol-based ionic liquid into hollow fibers (magnified image, right) to capture CO2 from the exhaust produced by coal-fired power plants. Ionic liquids, or salts that exist in liquid form, are promising materials for carbon capture and storage, but their tendency to thicken when combined with CO2 limits their efficiency and poses a challenge for their development as a cost-effective alternative to current-generation solutions. Adding alcohol to the mix limits this tendency to thicken in the presence of CO2 but can also make the liquid more likely to evaporate, which would add significantly to the cost of CO2 capture. To solve this problem, ORNL is developing new classes of ionic liquids with high capacity for absorbing CO2. ORNL’s sponge would reduce the cost associated with the energy that would need to be diverted from power plants to capture CO2 and release it for storage.

  11. Internal absorber solar collector

    DOEpatents

    Sletten, Carlyle J.; Herskovitz, Sheldon B.; Holt, F. S.; Sletten, E. J.

    1981-01-01

    Thin solar collecting panels are described made from arrays of small rod collectors consisting of a refracting dielectric rod lens with an absorber imbedded within it and a reflecting mirror coated on the back side of the dielectric rod. Non-tracking collector panels on vertical walls or roof tops receive approximately 90% of solar radiation within an acceptance zone 60.degree. in elevation angle by 120.degree. or more in the azimuth sectors with a collector concentration ratio of approximately 3.0. Miniaturized construction of the circular dielectric rods with internal absorbers reduces the weight per area of glass, plastic and metal used in the collector panels. No external parts or insulation are needed as heat losses are low due to partial vacuum or low conductivity gas surrounding heated portions of the collector. The miniature internal absorbers are generally made of solid copper with black selective surface and the collected solar heat is extracted at the collector ends by thermal conductivity along the absorber rods. Heat is removed from end fittings by use of liquid circulants. Several alternate constructions are provided for simplifying collector panel fabrication and for preventing the thermal expansion and contraction of the heated absorber or circulant tubes from damaging vacuum seals. In a modified version of the internal absorber collector, oil with temperature dependent viscosity is pumped through a segmented absorber which is now composed of closely spaced insulated metal tubes. In this way the circulant is automatically diverted through heated portions of the absorber giving higher collector concentration ratios than theoretically possible for an unsegmented absorber.

  12. Collagen dynamics of partial small bowel obstruction

    SciTech Connect

    Stromberg, B.V.; Klein, L.

    1984-08-01

    The response of intestinal collagen to obstruction and stress was studied in the rat. Partial small bowel obstructions were created. Preobstruction collagen was measured by injection of tritium labeled proline. New collagen formation after obstruction occurred was followed by injection of carbon-14 labeled proline. At 3 weeks, collagen fractions were identified. Throughout the study, preexisting preobstruction intestinal collagen was metabolically stable with no breakdown or remodeling demonstrable. New collagen formation was rapid and occurred to the largest degree close to the obstruction.

  13. Metal shearing energy absorber

    NASA Technical Reports Server (NTRS)

    Fay, R. J.; Wittrock, E. P. (Inventor)

    1973-01-01

    A metal shearing energy absorber is described. The absorber is composed of a flat thin strip of metal which is pulled through a slot in a cutter member of a metal, harder than the metal of the strip. The slot's length, in the direction perpendicular to the pull direction, is less than the strip's width so that as the strip is pulled through the slot, its edges are sheared off, thereby absorbing some of the pulling energy. In one embodiment the cutter member is a flat plate of steel, while in another embodiment the cutter member is U-shaped with the slot at its base.

  14. Lipid-absorbing Polymers

    NASA Technical Reports Server (NTRS)

    Marsh, H. E., Jr.; Wallace, C. J.

    1973-01-01

    The removal of bile acids and cholesterol by polymeric absorption is discussed in terms of micelle-polymer interaction. The results obtained with a polymer composed of 75 parts PEO and 25 parts PB plus curing ingredients show an absorption of 305 to 309%, based on original polymer weight. Particle size effects on absorption rate are analyzed. It is concluded that crosslinked polyethylene oxide polymers will absorb water, crosslinked polybutadiene polymers will absorb lipids; neither polymer will absorb appreciable amounts of lipids from micellar solutions of lipids in water.

  15. The Sponge Pump: The Role of Current Induced Flow in the Design of the Sponge Body Plan

    PubMed Central

    Leys, Sally P.; Yahel, Gitai; Reidenbach, Matthew A.; Tunnicliffe, Verena; Shavit, Uri; Reiswig, Henry M.

    2011-01-01

    Sponges are suspension feeders that use flagellated collar-cells (choanocytes) to actively filter a volume of water equivalent to many times their body volume each hour. Flow through sponges is thought to be enhanced by ambient current, which induces a pressure gradient across the sponge wall, but the underlying mechanism is still unknown. Studies of sponge filtration have estimated the energetic cost of pumping to be <1% of its total metabolism implying there is little adaptive value to reducing the cost of pumping by using “passive” flow induced by the ambient current. We quantified the pumping activity and respiration of the glass sponge Aphrocallistes vastus at a 150 m deep reef in situ and in a flow flume; we also modeled the glass sponge filtration system from measurements of the aquiferous system. Excurrent flow from the sponge osculum measured in situ and in the flume were positively correlated (r>0.75) with the ambient current velocity. During short bursts of high ambient current the sponges filtered two-thirds of the total volume of water they processed daily. Our model indicates that the head loss across the sponge collar filter is 10 times higher than previously estimated. The difference is due to the resistance created by a fine protein mesh that lines the collar, which demosponges also have, but was so far overlooked. Applying our model to the in situ measurements indicates that even modest pumping rates require an energetic expenditure of at least 28% of the total in situ respiration. We suggest that due to the high cost of pumping, current-induced flow is highly beneficial but may occur only in thin walled sponges living in high flow environments. Our results call for a new look at the mechanisms underlying current-induced flow and for reevaluation of the cost of biological pumping and its evolutionary role, especially in sponges. PMID:22180779

  16. Keratin sponge/hydrogel part 1. fabrication and characterization

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Keratin sponge/hydrogel products formed by either the oxidation or reduction of U.S. domestic fine- or coarse-grade wool exhibited distinctively different topologies and molecular weights of 6- 8 kDa and 40-60 kDa, each with unique macro-porous structure and microstructural behaviors. The sponge/ ...

  17. Prevalence and Mechanisms of Dynamic Chemical Defenses in Tropical Sponges

    PubMed Central

    Rohde, Sven; Nietzer, Samuel; Schupp, Peter J.

    2015-01-01

    Sponges and other sessile invertebrates are lacking behavioural escape or defense mechanisms and rely therefore on morphological or chemical defenses. Studies from terrestrial systems and marine algae demonstrated facultative defenses like induction and activation to be common, suggesting that sessile marine organisms also evolved mechanisms to increase the efficiency of their chemical defense. However, inducible defenses in sponges have not been investigated so far and studies on activated defenses are rare. We investigated whether tropical sponge species induce defenses in response to artificial predation and whether wounding triggers defense activation. Additionally, we tested if these mechanisms are also used to boost antimicrobial activity to avoid bacterial infection. Laboratory experiments with eight pacific sponge species showed that 87% of the tested species were chemically defended. Two species, Stylissa massa and Melophlus sarasinorum, induced defenses in response to simulated predation, which is the first demonstration of induced antipredatory defenses in marine sponges. One species, M. sarasinorum, also showed activated defense in response to wounding. Interestingly, 50% of the tested sponge species demonstrated induced antimicrobial defense. Simulated predation increased the antimicrobial defenses in Aplysinella sp., Cacospongia sp., M. sarasinorum, and S. massa. Our results suggest that wounding selects for induced antimicrobial defenses to protect sponges from pathogens that could otherwise invade the sponge tissue via feeding scars. PMID:26154741

  18. The Dimension of the Pore Space in Sponges

    ERIC Educational Resources Information Center

    Silva, L. H. F.; Yamashita, M. T.

    2009-01-01

    A simple experiment to reveal the dimension of the pore space in sponges is proposed. This experiment is suitable for the first year of a physics or engineering course. The calculated dimension of the void space in a sponge of density 16 mg cm[superscript -3] was 2.948 [plus or minus] 0.008. (Contains 2 figures.)

  19. Chemistry of verongida sponges. 9.1 secondary metabolite composition of the caribbean sponge aplysina cauliformis

    PubMed

    Ciminiello; Dell'Aversano; Fattorusso; Magno; Pansini

    1999-04-01

    A detailed analysis of the secondary metabolites of the sponge Aplysina cauliformis has been performed. Eight compounds were identified, two of which (13 and 14) are new bromotyrosine derivatives whose structures were determinated from spectroscopic evidence, including 2D NMR. The new compounds were analyzed for cytotoxic activity, and compound 14 was shown to inhibit mammalian protein synthesis and cell proliferation. PMID:10217716

  20. Engineered 3D Silk-collagen-based Model of Polarized Neural Tissue

    PubMed Central

    Chwalek, Karolina; Sood, Disha; Cantley, William L.; White, James D.; Tang-Schomer, Min; Kaplan, David L.

    2015-01-01

    Despite huge efforts to decipher the anatomy, composition and function of the brain, it remains the least understood organ of the human body. To gain a deeper comprehension of the neural system scientists aim to simplistically reconstruct the tissue by assembling it in vitro from basic building blocks using a tissue engineering approach. Our group developed a tissue-engineered silk and collagen-based 3D brain-like model resembling the white and gray matter of the cortex. The model consists of silk porous sponge, which is pre-seeded with rat brain-derived neurons, immersed in soft collagen matrix. Polarized neuronal outgrowth and network formation is observed with separate axonal and cell body localization. This compartmental architecture allows for the unique development of niches mimicking native neural tissue, thus enabling research on neuronal network assembly, axonal guidance, cell-cell and cell-matrix interactions and electrical functions. PMID:26555926

  1. Direct Oil Recovery from Saturated Carbon Nanotube Sponges.

    PubMed

    Li, Xiying; Xue, Yahui; Zou, Mingchu; Zhang, Dongxiao; Cao, Anyuan; Duan, Huiling

    2016-05-18

    Oil adsorption by porous materials is a major strategy for water purification and industrial spill cleanup; it is of great interest if the adsorbed oil can be safely recovered from those porous media. Here, direct oil recovery from fully saturated bulk carbon nanotube (CNT) sponges by displacing oil with water in controlled manner is shown. Surfactant-assisted electrocapillary imbibition is adopted to drive aqueous electrolyte into the sponge and extrude organic oil out continuously at low potentials (up to -1.2 V). More than 95 wt % of oil adsorbed within the sponge can be recovered, via a single electrocapillary process. Recovery of different oils with a wide range of viscosities is demonstrated, and the remaining CNT sponge can be reused with similar recovery capacity. A direct and efficient method is provided to recover oil from CNT sponges by water imbibition, which has many potential environmental and energy applications. PMID:27120687

  2. Type I Collagen and Collagen Mimetics as Angiogenesis Promoting Superpolymers

    SciTech Connect

    Twardowski, T.; Fertala, A.; Orgel, J.P.R.O.; San Antonio, J.D.

    2008-07-18

    Angiogenesis, the development of blood vessels from the pre-existing vasculature, is a key component of embryogenesis and tissue regeneration. Angiogenesis also drives pathologies such as tumor growth and metastasis, and hemangioma development in newborns. On the other hand, promotion of angiogenesis is needed in tissues with vascular insufficiencies, and in bioengineering, to endow tissue substitutes with appropriate microvasculatures. Therefore, much research has focused on defining mechanisms of angiogenesis, and identifying pro- and anti-angiogenic molecules. Type I collagen, the most abundant protein in humans, potently stimulates angiogenesis in vitro and in vivo. Crucial to its angiogenic activity appears to be ligation and possibly clustering of endothelial cell (EC) surface {alpha}1{beta}1/{alpha}2{beta}1 integrin receptors by the GFPGER502-507 sequence of the collagen fibril. However, additional aspects of collagen structure and function that may modulate its angiogenic properties are discussed. Moreover, type I collagen and fibrin, another angiogenic polymer, share several structural features. These observations suggest strategies for creating 'angiogenic superpolymers', including: modifying type I collagen to influence its biological half-life, immunogenicity, and integrin binding capacity; genetically engineering fibrillar collagens to include additional integrin binding sites or angiogenic determinants, and remove unnecessary or deleterious sequences without compromising fibril integrity; and exploring the suitability of poly(ortho ester), PEG-lysine copolymer, tubulin, and cholesteric cuticle as collagen mimetics, and suggesting means of modifying them to display ideal angiogenic properties. The collagenous and collagen mimetic angiogenic superpolymers described here may someday prove useful for many applications in tissue engineering and human medicine.

  3. "Smart" Electromechanical Shock Absorber

    NASA Technical Reports Server (NTRS)

    Stokes, Lebarian; Glenn, Dean C.; Carroll, Monty B.

    1989-01-01

    Shock-absorbing apparatus includes electromechanical actuator and digital feedback control circuitry rather than springs and hydraulic damping as in conventional shock absorbers. Device not subject to leakage and requires little or no maintenance. Attenuator parameters adjusted in response to sensory feedback and predictive algorithms to obtain desired damping characteristic. Device programmed to decelerate slowly approaching vehicle or other large object according to prescribed damping characteristic.

  4. Iron Chalcogenide Photovoltaic Absorbers

    SciTech Connect

    Yu, Liping; Lany, Stephan; Kykyneshi, Robert; Jieratum, Vorranutch; Ravichandran, Ram; Pelatt, Brian; Altschul, Emmeline; Platt, Heather A. S.; Wager, John F.; Keszler, Douglas A.; Zunger, Alex

    2011-08-10

    An integrated computational and experimental study of FeS₂ pyrite reveals that phase coexistence is an important factor limiting performance as a thin-film solar absorber. This phase coexistence is suppressed with the ternary materials Fe₂SiS₄ and Fe₂GeS₄, which also exhibit higher band gaps than FeS₂. Thus, the ternaries provide a new entry point for development of thin-film absorbers and high-efficiency photovoltaics.

  5. Nonviable Staphylococcus aureus and its peptidoglycan stimulate macrophage recruitment, angiogenesis, fibroplasia, and collagen accumulation in wounded rats.

    PubMed

    Kilcullen, J K; Ly, Q P; Chang, T H; Levenson, S M; Steinberg, J J

    1998-01-01

    within the interstices of the sponges at the interface between reparative tissue and acute inflammatory cells. In contrast, saline-treated sponge reparative tissue had significantly fewer macrophages, much thinner and flimsy reparative tissue, with proportionately fewer macrophages clustering centrally. There were many more mesenchymal cells (notably fibroblasts) and new blood vessels and much more reparative collagen in the nonviable S. aureus or S. aureus peptidoglycan-treated sponges. We conclude that local application of nonviable S. aureus or S. aureus peptidoglycan at wounding induces an increased number and alteration in location of macrophages, increased influx (or proliferation) of mesenchymal cells (notably fibroblasts), and increased angiogenesis and reparative collagen accumulation, as well as increasing the overall acute inflammatory response to wounding. PMID:9776858

  6. Enhancement of chondrogenic differentiation of rabbit mesenchymal stem cells by oriented nanofiber yarn-collagen type I/hyaluronate hybrid.

    PubMed

    Zheng, Xianyou; Wang, Wei; Liu, Shen; Wu, Jinglei; Li, Fengfeng; Cao, Lei; Liu, Xu-dong; Mo, Xiumei; Fan, Cunyi

    2016-01-01

    Cartilage defects cause joint pain and loss of mobility. It is crucial to induce the chondrogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) by both biological and structural signals in cartilage tissue engineering. Sponge-like scaffolds fabricated using native cartilage extracellular matrix components can induce the BMSC differentiation by biological signals and limited structural signals. In this study, an oriented poly(L-lactic acid)-co-poly(ε-caprolactone) P(LLA-CL)/collagen type I (Col-I) nanofiber yarn mesh, fabricated by dynamic liquid electrospinning served as a skeleton for a freeze-dried Col-I/hyaluronate (HA) chondral phase (SPONGE) containing both structural and biological signals to guide BMSC chondrogenic differentiation. In vitro results show that the Yarn Col-I/HA hybrid scaffold (Yarn-CH) promotes orientation, adhesion and proliferation of BMSCs better than SPONGE. Furthermore, BMSCs seeded on the Yarn-CH scaffold demonstrated a large increase in the glycosaminoglycan content and expression of collagen type II following a 21-day culture. PMID:26478405

  7. Carbon conversion and metabolic rate in two marine sponges.

    PubMed

    Koopmans, M; van Rijswijk, P; Martens, D; Egorova-Zachernyuk, T A; Middelburg, J J; Wijffels, R H

    2011-01-01

    The carbon metabolism of two marine sponges, Haliclona oculata and Dysidea avara, has been studied using a (13)C isotope pulse-chase approach. The sponges were fed (13)C-labeled diatoms (Skeletonema costatum) for 8 h and they took up between 75 and 85%. At different times, sponges were sampled for total (13)C enrichment, and fatty acid (FA) composition and (13)C enrichment. Algal biomarkers present in the sponges were highly labeled after feeding but their labeling levels decreased until none was left 10 days after enrichment. The sponge-specific FAs incorporated (13)C label already during the first day and the amount of (13)C label inside these FAs kept increasing until 3 weeks after labeling. The algal-derived carbon captured by the sponges during the 8-h feeding period was thus partly respired and partly metabolized during the weeks following. Apparently, sponges are able to capture enough food during short periods to sustain longer-term metabolism. The change of carbon metabolic rate of fatty acid synthesis due to mechanical damage of sponge tissue was studied by feeding sponges with (13)C isotope-labeled diatom (Pheaodactylum tricornutum) either after or before damaging and tracing back the (13)C content in the damaged and healthy tissue. The filtration and respiration in both sponges responded quickly to damage. The rate of respiration in H. oculata reduced immediately after damage, but returned to its initial level after 6 h. The (13)C data revealed that H. oculata has a higher metabolic rate in the tips where growth occurs compared to the rest of the tissue and that the metabolic rate is increased after damage of the tissue. For D. avara, no differences were found between damaged and non-damaged tissue. However, the filtration rate decreased directly after damage. PMID:24489407

  8. Correlative nonlinear optical microscopy and infrared nanoscopy reveals collagen degradation in altered parchments

    NASA Astrophysics Data System (ADS)

    Latour, Gaël; Robinet, Laurianne; Dazzi, Alexandre; Portier, François; Deniset-Besseau, Ariane; Schanne-Klein, Marie-Claire

    2016-05-01

    This paper presents the correlative imaging of collagen denaturation by nonlinear optical microscopy (NLO) and nanoscale infrared (IR) spectroscopy to obtain morphological and chemical information at different length scales. Such multiscale correlated measurements are applied to the investigation of ancient parchments, which are mainly composed of dermal fibrillar collagen. The main issue is to characterize gelatinization, the ultimate and irreversible alteration corresponding to collagen denaturation to gelatin, which may also occur in biological tissues. Key information about collagen and gelatin signatures is obtained in parchments and assessed by characterizing the denaturation of pure collagen reference samples. A new absorbing band is observed near the amide I band in the IR spectra, correlated to the onset of fluorescence signals in NLO images. Meanwhile, a strong decrease is observed in Second Harmonic signals, which are a structural probe of the fibrillar organization of the collagen at the micrometer scale. NLO microscopy therefore appears as a powerful tool to reveal collagen degradation in a non-invasive way. It should provide a relevant method to assess or monitor the condition of collagen-based materials in museum and archival collections and opens avenues for a broad range of applications regarding this widespread biological material.

  9. Fourier transform infrared spectroscopic imaging of cardiac tissue to detect collagen deposition after myocardial infarction

    NASA Astrophysics Data System (ADS)

    Cheheltani, Rabee; Rosano, Jenna M.; Wang, Bin; Sabri, Abdel Karim; Pleshko, Nancy; Kiani, Mohammad F.

    2012-05-01

    Myocardial infarction often leads to an increase in deposition of fibrillar collagen. Detection and characterization of this cardiac fibrosis is of great interest to investigators and clinicians. Motivated by the significant limitations of conventional staining techniques to visualize collagen deposition in cardiac tissue sections, we have developed a Fourier transform infrared imaging spectroscopy (FT-IRIS) methodology for collagen assessment. The infrared absorbance band centered at 1338 cm-1, which arises from collagen amino acid side chain vibrations, was used to map collagen deposition across heart tissue sections of a rat model of myocardial infarction, and was compared to conventional staining techniques. Comparison of the size of the collagen scar in heart tissue sections as measured with this methodology and that of trichrome staining showed a strong correlation (R=0.93). A Pearson correlation model between local intensity values in FT-IRIS and immuno-histochemical staining of collagen type I also showed a strong correlation (R=0.86). We demonstrate that FT-IRIS methodology can be utilized to visualize cardiac collagen deposition. In addition, given that vibrational spectroscopic data on proteins reflect molecular features, it also has the potential to provide additional information about the molecular structure of cardiac extracellular matrix proteins and their alterations.

  10. Correlative nonlinear optical microscopy and infrared nanoscopy reveals collagen degradation in altered parchments.

    PubMed

    Latour, Gaël; Robinet, Laurianne; Dazzi, Alexandre; Portier, François; Deniset-Besseau, Ariane; Schanne-Klein, Marie-Claire

    2016-01-01

    This paper presents the correlative imaging of collagen denaturation by nonlinear optical microscopy (NLO) and nanoscale infrared (IR) spectroscopy to obtain morphological and chemical information at different length scales. Such multiscale correlated measurements are applied to the investigation of ancient parchments, which are mainly composed of dermal fibrillar collagen. The main issue is to characterize gelatinization, the ultimate and irreversible alteration corresponding to collagen denaturation to gelatin, which may also occur in biological tissues. Key information about collagen and gelatin signatures is obtained in parchments and assessed by characterizing the denaturation of pure collagen reference samples. A new absorbing band is observed near the amide I band in the IR spectra, correlated to the onset of fluorescence signals in NLO images. Meanwhile, a strong decrease is observed in Second Harmonic signals, which are a structural probe of the fibrillar organization of the collagen at the micrometer scale. NLO microscopy therefore appears as a powerful tool to reveal collagen degradation in a non-invasive way. It should provide a relevant method to assess or monitor the condition of collagen-based materials in museum and archival collections and opens avenues for a broad range of applications regarding this widespread biological material. PMID:27194180

  11. Correlative nonlinear optical microscopy and infrared nanoscopy reveals collagen degradation in altered parchments

    PubMed Central

    Latour, Gaël; Robinet, Laurianne; Dazzi, Alexandre; Portier, François; Deniset-Besseau, Ariane; Schanne-Klein, Marie-Claire

    2016-01-01

    This paper presents the correlative imaging of collagen denaturation by nonlinear optical microscopy (NLO) and nanoscale infrared (IR) spectroscopy to obtain morphological and chemical information at different length scales. Such multiscale correlated measurements are applied to the investigation of ancient parchments, which are mainly composed of dermal fibrillar collagen. The main issue is to characterize gelatinization, the ultimate and irreversible alteration corresponding to collagen denaturation to gelatin, which may also occur in biological tissues. Key information about collagen and gelatin signatures is obtained in parchments and assessed by characterizing the denaturation of pure collagen reference samples. A new absorbing band is observed near the amide I band in the IR spectra, correlated to the onset of fluorescence signals in NLO images. Meanwhile, a strong decrease is observed in Second Harmonic signals, which are a structural probe of the fibrillar organization of the collagen at the micrometer scale. NLO microscopy therefore appears as a powerful tool to reveal collagen degradation in a non-invasive way. It should provide a relevant method to assess or monitor the condition of collagen-based materials in museum and archival collections and opens avenues for a broad range of applications regarding this widespread biological material. PMID:27194180

  12. 21 CFR 878.4014 - Nonresorbable gauze/sponge for external use.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Nonresorbable gauze/sponge for external use. 878... Nonresorbable gauze/sponge for external use. (a) Identification. A nonresorbable gauze/sponge for external use... include a nonresorbable gauze/sponge for external use that contains added drugs such as...

  13. 21 CFR 878.4014 - Nonresorbable gauze/sponge for external use.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Nonresorbable gauze/sponge for external use. 878... Nonresorbable gauze/sponge for external use. (a) Identification. A nonresorbable gauze/sponge for external use... include a nonresorbable gauze/sponge for external use that contains added drugs such as...

  14. 21 CFR 878.4014 - Nonresorbable gauze/sponge for external use.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Nonresorbable gauze/sponge for external use. 878... Nonresorbable gauze/sponge for external use. (a) Identification. A nonresorbable gauze/sponge for external use... include a nonresorbable gauze/sponge for external use that contains added drugs such as...

  15. 21 CFR 878.4014 - Nonresorbable gauze/sponge for external use.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Nonresorbable gauze/sponge for external use. 878... Nonresorbable gauze/sponge for external use. (a) Identification. A nonresorbable gauze/sponge for external use... include a nonresorbable gauze/sponge for external use that contains added drugs such as...

  16. 21 CFR 878.4014 - Nonresorbable gauze/sponge for external use.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Nonresorbable gauze/sponge for external use. 878... Nonresorbable gauze/sponge for external use. (a) Identification. A nonresorbable gauze/sponge for external use... include a nonresorbable gauze/sponge for external use that contains added drugs such as...

  17. 46 CFR 148.275 - Iron oxide, spent; iron sponge, spent.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Iron oxide, spent; iron sponge, spent. 148.275 Section... § 148.275 Iron oxide, spent; iron sponge, spent. (a) Before spent iron oxide or spent iron sponge is... been cooled and weathered for at least eight weeks. (b) Both spent iron oxide and spent iron sponge...

  18. 46 CFR 148.275 - Iron oxide, spent; iron sponge, spent.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Iron oxide, spent; iron sponge, spent. 148.275 Section... § 148.275 Iron oxide, spent; iron sponge, spent. (a) Before spent iron oxide or spent iron sponge is... been cooled and weathered for at least eight weeks. (b) Both spent iron oxide and spent iron sponge...

  19. 46 CFR 148.275 - Iron oxide, spent; iron sponge, spent.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Iron oxide, spent; iron sponge, spent. 148.275 Section... § 148.275 Iron oxide, spent; iron sponge, spent. (a) Before spent iron oxide or spent iron sponge is... been cooled and weathered for at least eight weeks. (b) Both spent iron oxide and spent iron sponge...

  20. 46 CFR 148.275 - Iron oxide, spent; iron sponge, spent.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Iron oxide, spent; iron sponge, spent. 148.275 Section... § 148.275 Iron oxide, spent; iron sponge, spent. (a) Before spent iron oxide or spent iron sponge is... been cooled and weathered for at least eight weeks. (b) Both spent iron oxide and spent iron sponge...

  1. Lifestyle Evolution in Cyanobacterial Symbionts of Sponges

    PubMed Central

    Burgsdorf, Ilia; Slaby, Beate M.; Handley, Kim M.; Haber, Markus; Blom, Jochen; Marshall, Christopher W.; Gilbert, Jack A.; Hentschel, Ute

    2015-01-01

    ABSTRACT The “Candidatus Synechococcus spongiarum” group includes different clades of cyanobacteria with high 16S rRNA sequence identity (~99%) and is the most abundant and widespread cyanobacterial symbiont of marine sponges. The first draft genome of a “Ca. Synechococcus spongiarum” group member was recently published, providing evidence of genome reduction by loss of genes involved in several nonessential functions. However, “Ca. Synechococcus spongiarum” includes a variety of clades that may differ widely in genomic repertoire and consequently in physiology and symbiotic function. Here, we present three additional draft genomes of “Ca. Synechococcus spongiarum,” each from a different clade. By comparing all four symbiont genomes to those of free-living cyanobacteria, we revealed general adaptations to life inside sponges and specific adaptations of each phylotype. Symbiont genomes shared about half of their total number of coding genes. Common traits of “Ca. Synechococcus spongiarum” members were a high abundance of DNA modification and recombination genes and a reduction in genes involved in inorganic ion transport and metabolism, cell wall biogenesis, and signal transduction mechanisms. Moreover, these symbionts were characterized by a reduced number of antioxidant enzymes and low-weight peptides of photosystem II compared to their free-living relatives. Variability within the “Ca. Synechococcus spongiarum” group was mostly related to immune system features, potential for siderophore-mediated iron transport, and dependency on methionine from external sources. The common absence of genes involved in synthesis of residues, typical of the O antigen of free-living Synechococcus species, suggests a novel mechanism utilized by these symbionts to avoid sponge predation and phage attack. PMID:26037118

  2. Lifestyle Evolution in Cyanobacterial Symbionts of Sponges

    DOE PAGESBeta

    Burgsdorf, Ilia; Slaby, Beate M.; Handley, Kim M.; Haber, Markus; Blom, Jochen; Marshall, Christopher W.; Gilbert, Jack A.; Hentschel, Ute; Steindler, Laura

    2015-06-02

    The “Candidatus Synechococcus spongiarum” group includes different clades of cyanobacteria with high 16S rRNA sequence identity (~99%) and is the most abundant and widespread cyanobacterial symbiont of marine sponges. The first draft genome of a “Ca. Synechococcus spongiarum” group member was recently published, providing evidence of genome reduction by loss of genes involved in several nonessential functions. However, “Ca. Synechococcus spongiarum” includes a variety of clades that may differ widely in genomic repertoire and consequently in physiology and symbiotic function. Here, we present three additional draft genomes of “Ca. Synechococcus spongiarum,” each from a different clade. By comparing all fourmore » symbiont genomes to those of free-living cyanobacteria, we revealed general adaptations to life inside sponges and specific adaptations of each phylotype. Symbiont genomes shared about half of their total number of coding genes. Common traits of “Ca. Synechococcus spongiarum” members were a high abundance of DNA modification and recombination genes and a reduction in genes involved in inorganic ion transport and metabolism, cell wall biogenesis, and signal transduction mechanisms. Moreover, these symbionts were characterized by a reduced number of antioxidant enzymes and low-weight peptides of photosystem II compared to their free-living relatives. Variability within the “Ca. Synechococcus spongiarum” group was mostly related to immune system features, potential for siderophore-mediated iron transport, and dependency on methionine from external sources. The common absence of genes involved in synthesis of residues, typical of the O antigen of free-living Synechococcus species, suggests a novel mechanism utilized by these symbionts to avoid sponge predation and phage attack.« less

  3. Lifestyle Evolution in Cyanobacterial Symbionts of Sponges

    SciTech Connect

    Burgsdorf, Ilia; Slaby, Beate M.; Handley, Kim M.; Haber, Markus; Blom, Jochen; Marshall, Christopher W.; Gilbert, Jack A.; Hentschel, Ute; Steindler, Laura

    2015-06-02

    The “Candidatus Synechococcus spongiarum” group includes different clades of cyanobacteria with high 16S rRNA sequence identity (~99%) and is the most abundant and widespread cyanobacterial symbiont of marine sponges. The first draft genome of a “Ca. Synechococcus spongiarum” group member was recently published, providing evidence of genome reduction by loss of genes involved in several nonessential functions. However, “Ca. Synechococcus spongiarum” includes a variety of clades that may differ widely in genomic repertoire and consequently in physiology and symbiotic function. Here, we present three additional draft genomes of “Ca. Synechococcus spongiarum,” each from a different clade. By comparing all four symbiont genomes to those of free-living cyanobacteria, we revealed general adaptations to life inside sponges and specific adaptations of each phylotype. Symbiont genomes shared about half of their total number of coding genes. Common traits of “Ca. Synechococcus spongiarum” members were a high abundance of DNA modification and recombination genes and a reduction in genes involved in inorganic ion transport and metabolism, cell wall biogenesis, and signal transduction mechanisms. Moreover, these symbionts were characterized by a reduced number of antioxidant enzymes and low-weight peptides of photosystem II compared to their free-living relatives. Variability within the “Ca. Synechococcus spongiarum” group was mostly related to immune system features, potential for siderophore-mediated iron transport, and dependency on methionine from external sources. The common absence of genes involved in synthesis of residues, typical of the O antigen of free-living Synechococcus species, suggests a novel mechanism utilized by these symbionts to avoid sponge predation and phage attack.

  4. Cytotoxic Terpene Quinones from Marine Sponges

    PubMed Central

    Gordaliza, Marina

    2010-01-01

    The 1,4-benzoquinone moiety is a common structural feature in a large number of compounds that have received considerable attention owing to their broad spectrum of biological activities. The cytotoxic and antiproliferative properties of many natural sesquiterpene quinones and hydroquinones from sponges of the order Dictyoceratida, such as avarol, avarone, illimaquinone, nakijiquinone and bolinaquinone, offer promising opportunities for the development of new antitumor agents. The present review summarizes the structure and cytotoxicity of natural terpenequinones/hydroquinones and their bioactive analogues and derivatives. PMID:21339953

  5. Silica Synthesis by Sponges: Unanticipated Molecular Mechanism

    NASA Astrophysics Data System (ADS)

    Morse, D. E.; Weaver, J. C.

    2001-12-01

    Oceanic diatoms, sponges and other organisms synthesize gigatons per year of silica from silicic acid, ultimately obtained from the weathering of rock. This biogenic silica exhibits a remarkable diversity of structures, many of which reveal a precision of nanoarchitectural control that exceeds the capabilities of human engineering. In contrast to the conditions of anthropogenic and industrial manufacture, the biological synthesis of silica occurs under mild physiological conditions of low temperatures and pressures and near-neutral pH. In addition to the differentiation between biological and abiotic processes governing silica formation, the biomolecular mechanisms controlling synthesis of these materials may offer insights for the development of new, environmentally benign routes for synthesis of nanostructurally controlled silicas and high-performance polysiloxane composites. We found that the needle-like silica spicules made by the marine sponge, Tethya aurantia, each contain an occluded axial filament of protein composed predominantly of repeating assemblies of three similar subunits we named "silicateins." To our surprise, analysis of the purified protein subunits and the cloned silicatein DNAs revealed that the silicateins are highly homologous to a family of hydrolytic enzymes. As predicted from this finding, we discovered that the silicatein filaments are more than simple, passive templates; they actively catalyze and spatially direct polycondensation to form silica, (as well as the phenyl- and methyl-silsesquioxane) from the corresponding silicon alkoxides at neutral pH and low temperature. Catalytic activity also is exhibited by the silicatein subunits obtained by disaggregation of the protein filaments and those produced from recombinant DNA templates cloned in bacteria. This catalytic activity accelerates the rate-limiting hydrolysis of the silicon alkoxide precursors. Genetic engineering, used to produce variants of the silicatein molecule with

  6. Collagen fibril formation during development

    SciTech Connect

    Fleischmajer, R.; Perlish, J.S.; Timpl, R.; Olsen, B.R.

    1987-05-01

    Studies with embryonic skin and bone suggested that the aminopropeptide (AP) and carboxylpropeptide (CP) of type I pro-callagen (pro-col) play a role in fibril formation. Chick leg metatarsal tendons were studied by electron microscopy. AP and CP of type I pro-col were purified from chick leg tendons; antibodies developed in rabbits and purity tested by radioimmunoassays. Antibodies were used for immunofluorescence microscopy (IFM) and immunoblotting (IB). The peritendineum, consisting of thin 20-30 nm fibrils, revealed the AP of type I and type III procol. In the tendon area, collagen fibrils were arranged within small compartments and were of uniform diameter at 10d, 14d and 18d. However, beyond 21d, there was confluency of the compartments and a wide range of fibril diameters. IFM revealed fine streaks of collagen, staining with the AP of type I throughout the tendon. The CP was mainly intracellular with only a small amount present in the extracellular space. IB revealed procollagen, pN-collagen (AP+collagen) and pC-collagen, (CP+collagen) at all stages of development. Ratios of pN/pC collagen, determined by spectrophotometric scanning of autoradiographs, correlated well with the distribution of fibril diameter. This study suggests the hypothesis that AP initiates fibrillogenesis while CP may regulate additional fibril growth.

  7. Socket augmentation using a commercial collagen-based product--an animal study in pigs.

    PubMed

    Kunert-Keil, Christiane; Gredes, Tomasz; Heinemann, Friedhelm; Dominiak, Marzena; Botzenhart, Ute; Gedrange, Tomasz

    2015-01-01

    The aim of the present study was to identify properties of pure collagen for augmentation techniques and compare to a proved xenogenic material and natural bone regeneration. For that the osteogenesis of extraction alveoli after augmentation with a collagen cone covered with an absorbable collagen membrane in a single product (PARASORB Sombrero®, Resorba) was evaluated in a pig model. Extraction alveoli were treated with the collagen cone and the collagen membrane in a single product (test group; n=7) or demineralized bovine bone mineral and a collagen membrane (two separate products; positive control; n=7). Untreated alveoli were used (n=6) as negative controls.(1) Bone specimens were extracted 1 and 3 months after teeth extraction. Serial longitudinal sections were stained with Masson Goldner trichrome. Furthermore, bone specimens were examined using X-ray analyses. Significant differences of bone atrophy were detected 12 weeks after material insertion using X-ray analyses. The bone atrophy was reduced by approximately 32% after insertion of the positive control (P=0.046). Bone atrophy reached 37.6% of those from untreated alveoli (P=0.002) using the test group. After 4 weeks, bone formation was noticeable in most sites, whereas after 12 weeks of healing, specimens of all groups exhibited nearly complete osseous organization of the former defected area. The mandibulary bone texture showed typical spongious bone structures. Histomorphometric analyses revealed after 4 and 12 weeks significant higher levels of bone marrow in test and negative control than in positive control. Quantification of bone tissue and osteoid does not show any significant difference. The present study confirms reduced bone resorption following socket augmentation with an absorbable collagen membrane with collagen cone while the resulting bone structure is similar to natural bone regeneration. Pure collagen can be used for bone augmentation, and shows over other xenogenic materials, a clear

  8. Thermal and infrared-diode laser effects on indocyanine-green-treated corneal collagen

    NASA Astrophysics Data System (ADS)

    Timberlake, George T.; Patmore, Ann; Shallal, Assaad; McHugh, Dominic; Marshall, John

    1993-07-01

    It has been suggested that laser welds of collagenous tissues form by interdigitation and chemical bonding of thermally 'unraveled' collagen fibrils. We investigated this proposal by attempting to weld highly collagenous, avascular corneal tissue with an infrared (IR) diode laser as follows. First, the temperature at which corneal collagen shrinks and collagen fibrils 'split' into subfibrillary components was determined. Second, since use of a near-IR laser wavelength necessitated addition of an absorbing dye (indocyanine green (ICG) to the cornea, we measured absorption spectra of ICG-treated tissue to ensure that peak ICG absorbance did not change markedly when ICG was present in the cornea. Third, using gel electrophoresis of thermally altered corneal collagen, we searched for covalently crosslinked compounds predicted by the proposed welding mechanism. Finally, we attempted to weld partial thickness corneal incisions infused with ICG. Principal experimental findings were as follows: (1) Human corneal (type I) collagen splits into subfibrillary components at approximately 63 degree(s)C, the same temperature that produces collagen shrinkage. (2) Peak ICG absorption does not change significantly in corneal stroma or with laser heating. (3) No evidence was found for the formation of novel compounds or the loss of proteins as a result of tissue heating. All tissue treated with ICG, however, exhibited a novel 244 kD protein band indicating chemical activity between collagen and corneal stromal components. (4) Laser welding corneal incisions was unsuccessful possibly due to shrinkage of the sides of the incision, lack of incision compression during heating, or a less than optimal combination of ICG concentration and radiant exposure. In summary, these experiments demonstrate the biochemical and morphological complexity of ICG-enhanced IR laser-tissue welding and the need for further investigation of laser welding mechanisms.

  9. Electrostatic effects in collagen fibrillization

    NASA Astrophysics Data System (ADS)

    Morozova, Svetlana; Muthukumar, Murugappan

    2014-03-01

    Using light scattering and AFM techniques, we have measured the kinetics of fibrillization of collagen (pertinent to the vitreous of human eye) as a function of pH and ionic strength. At higher and lower pH, collagen triple-peptides remain stable in solution without fibrillization. At neutral pH, the fibrillization occurs and its growth kinetics is slowed upon either an increase in ionic strength or a decrease in temperature. We present a model, based on polymer crystallization theory, to describe the observed electrostatic nature of collagen assembly.

  10. Nature designs tough collagen: Explaining the nanostructure of collagen fibrils

    PubMed Central

    Buehler, Markus J.

    2006-01-01

    Collagen is a protein material with superior mechanical properties. It consists of collagen fibrils composed of a staggered array of ultra-long tropocollagen (TC) molecules. Theoretical and molecular modeling suggests that this natural design of collagen fibrils maximizes the strength and provides large energy dissipation during deformation, thus creating a tough and robust material. We find that the mechanics of collagen fibrils can be understood quantitatively in terms of two critical molecular length scales χS and χR that characterize when (i) deformation changes from homogeneous intermolecular shear to propagation of slip pulses and when (ii) covalent bonds within TC molecules begin to fracture, leading to brittle-like failure. The ratio χS/χR indicates which mechanism dominates deformation. Our modeling rigorously links the chemical properties of individual TC molecules to the macroscopic mechanical response of fibrils. The results help to explain why collagen fibers found in nature consist of TC molecules with lengths in the proximity of 300 nm and advance the understanding how collagen diseases that change intermolecular adhesion properties influence mechanical properties. PMID:16895989

  11. Marine Sponges as a Drug Treasure

    PubMed Central

    Anjum, Komal; Abbas, Syed Qamar; Shah, Sayed Asmat Ali; Akhter, Najeeb; Batool, Sundas; Hassan, Syed Shams ul

    2016-01-01

    Marine sponges have been considered as a drug treasure house with respect to great potential regarding their secondary metabolites. Most of the studies have been conducted on sponge’s derived compounds to examine its pharmacological properties. Such compounds proved to have antibacterial, antiviral, antifungal, antimalarial, antitumor, immunosuppressive, and cardiovascular activity. Although, the mode of action of many compounds by which they interfere with human pathogenesis have not been clear till now, in this review not only the capability of the medicinal substances have been examined in vitro and in vivo against serious pathogenic microbes but, the mode of actions of medicinal compounds were explained with diagrammatic illustrations. This knowledge is one of the basic components to be known especially for transforming medicinal molecules to medicines. Sponges produce a different kind of chemical substances with numerous carbon skeletons, which have been found to be the main component interfering with human pathogenesis at different sites. The fact that different diseases have the capability to fight at different sites inside the body can increase the chances to produce targeted medicines. PMID:27350338

  12. Origin of Metazoa: Sponges as Living Fossils

    NASA Astrophysics Data System (ADS)

    Müller, Werner E. G.

    1998-01-01

    , which code for proteins. The analyses of their deduced amino acid sequences allowed a molecular biological approach to solve the problem of monophyly of Metazoa. Molecules of the extracellular matrix/basal lamina, with the integrin receptor, fibronectin, and galectin as prominent examples, cell-surface receptors (tyrosine kinase receptor), elements of sensory systems (crystallin, metabotropic glutamate receptor), and homologs/modules of an immune system (immunoglobulin like molecules, scavenger receptor cysteine-rich, and short consensus repeats, rhesus system) classify the Porifera as true Metazoa. As living fossils, provided with simple, primordial molecules allowing cell-cell and cell-matrix adhesion as well as processes of signal transduction as known in a more complex manner from higher Metazoa, they also show peculiarities not known in other metazoan phyla. Tissues of sponges are rich in telomerase activity, suggesting a high plasticity in the determination of cell lineages. It is concluded that molecular biological studies with sponges as model will not only help to understand the evolution of Protoctista to Metazoa but also the complex, hierarchial regulatory network of cells in higher Metazoa.

  13. Mesoscale elastic properties of marine sponge spicules.

    PubMed

    Zhang, Yaqi; Reed, Bryan W; Chung, Frank R; Koski, Kristie J

    2016-01-01

    Marine sponge spicules are silicate fibers with an unusual combination of fracture toughness and optical light propagation properties due to their micro- and nano-scale hierarchical structure. We present optical measurements of the elastic properties of Tethya aurantia and Euplectella aspergillum marine sponge spicules using non-invasive Brillouin and Raman laser light scattering, thus probing the hierarchical structure on two very different scales. On the scale of single bonds, as probed by Raman scattering, the spicules resemble a combination of pure silica and mixed organic content. On the mesoscopic scale probed by Brillouin scattering, we show that while some properties (Young's moduli, shear moduli, one of the anisotropic Poisson ratios and refractive index) are nearly the same as those of artificial optical fiber, other properties (uniaxial moduli, bulk modulus and a distinctive anisotropic Poisson ratio) are significantly smaller. Thus this natural composite of largely isotropic materials yields anisotropic elastic properties on the mesoscale. We show that the spicules' optical waveguide properties lead to pronounced spontaneous Brillouin backscattering, a process related to the stimulated Brillouin backscattering process well known in artificial glass fibers. These measurements provide a clearer picture of the interplay of flexibility, strength, and material microstructure for future functional biomimicry. PMID:26672719

  14. Sterols from the Madagascar sponge Fascaplysinopsis sp.

    PubMed

    Aknin, Maurice; Gros, Emmanuelle; Vacelet, Jean; Kashman, Yoel; Gauvin-Bialecki, Anne

    2010-01-01

    The sponge Fascaplysinopsis sp. (order Dictyoceratida, Family Thorectidae) from the west coast of Madagascar (Indian Ocean) is a particularly rich source of bioactive nitrogenous macrolides. The previous studies on this organism led to the suggestion that the latter should originate from associated microsymbionts. In order to evaluate the influence of microsymbionts on lipid content, 10 samples of Fascaplysinopsis sp. were investigated for their sterol composition. Contrary to the secondary metabolites, the sterol patterns established were qualitatively and quantitatively stable: 14 sterols with different unsaturated nuclei, Δ(5), Δ(7) and Δ(5,7), were identified; the last ones being the main sterols of the investigated sponges. The chemotaxonomic significance of these results for the order Dictyoceratida is also discussed in the context of the literature. The conjugated diene system in Δ(5,7) sterols is known to be unstable and easily photo-oxidized during storage and/or experiments to produce 5α,8α-epidioxy sterols. However, in this study, no 5α,8α-epidioxysterols (or only trace amounts) were observed. Thus, it was supposed that photo-oxidation was avoided thanks to the natural antioxidants detected in Fascaplysinopsis sp. by both the DPPH and β-caroten bleaching assays. PMID:21339959

  15. Preliminary Assessment of Sponge Biodiversity on Saba Bank, Netherlands Antilles

    PubMed Central

    Thacker, Robert W.; Díaz, M. Cristina; de Voogd, Nicole J.; van Soest, Rob W. M.; Freeman, Christopher J.; Mobley, Andrew S.; LaPietra, Jessica; Cope, Kevin; McKenna, Sheila

    2010-01-01

    Background Saba Bank Atoll, Netherlands Antilles, is one of the three largest atolls on Earth and provides habitat for an extensive coral reef community. To improve our knowledge of this vast marine resource, a survey of biodiversity at Saba Bank included a multi-disciplinary team that sampled fishes, mollusks, crustaceans, macroalgae, and sponges. Methodology/Principal Findings A single member of the dive team conducted surveys of sponge biodiversity during eight dives at six locations, at depths ranging from 15 to 30 m. This preliminary assessment documented the presence of 45 species pooled across multiple locations. Rarefaction analysis estimated that only 48 to 84% of species diversity was sampled by this limited effort, clearly indicating a need for additional surveys. An analysis of historical collections from Saba and Saba Bank revealed an additional 36 species, yielding a total of 81 sponge species recorded from this area. Conclusions/Significance This observed species composition is similar to that found on widespread Caribbean reefs, indicating that the sponge fauna of Saba Bank is broadly representative of the Caribbean as a whole. A robust population of the giant barrel sponge, Xestospongia muta, appeared healthy with none of the signs of disease or bleaching reported from other Caribbean reefs; however, more recent reports of anchor chain damage to these sponges suggests that human activities can have dramatic impacts on these communities. Opportunities to protect this extremely large habitat should be pursued, as Saba Bank may serve as a significant reservoir of sponge species diversity. PMID:20502643

  16. Bioprospecting Sponge-Associated Microbes for Antimicrobial Compounds.

    PubMed

    Indraningrat, Anak Agung Gede; Smidt, Hauke; Sipkema, Detmer

    2016-05-01

    Sponges are the most prolific marine organisms with respect to their arsenal of bioactive compounds including antimicrobials. However, the majority of these substances are probably not produced by the sponge itself, but rather by bacteria or fungi that are associated with their host. This review for the first time provides a comprehensive overview of antimicrobial compounds that are known to be produced by sponge-associated microbes. We discuss the current state-of-the-art by grouping the bioactive compounds produced by sponge-associated microorganisms in four categories: antiviral, antibacterial, antifungal and antiprotozoal compounds. Based on in vitro activity tests, identified targets of potent antimicrobial substances derived from sponge-associated microbes include: human immunodeficiency virus 1 (HIV-1) (2-undecyl-4-quinolone, sorbicillactone A and chartarutine B); influenza A (H1N1) virus (truncateol M); nosocomial Gram positive bacteria (thiopeptide YM-266183, YM-266184, mayamycin and kocurin); Escherichia coli (sydonic acid), Chlamydia trachomatis (naphthacene glycoside SF2446A2); Plasmodium spp. (manzamine A and quinolone 1); Leishmania donovani (manzamine A and valinomycin); Trypanosoma brucei (valinomycin and staurosporine); Candida albicans and dermatophytic fungi (saadamycin, 5,7-dimethoxy-4-p-methoxylphenylcoumarin and YM-202204). Thirty-five bacterial and 12 fungal genera associated with sponges that produce antimicrobials were identified, with Streptomyces, Pseudovibrio, Bacillus, Aspergillus and Penicillium as the prominent producers of antimicrobial compounds. Furthemore culture-independent approaches to more comprehensively exploit the genetic richness of antimicrobial compound-producing pathways from sponge-associated bacteria are addressed. PMID:27144573

  17. Reproductive patterns in three species of large coral reef sponges

    NASA Astrophysics Data System (ADS)

    Hoppe, Wilfried F.

    1988-05-01

    The type and frequency of reproduction of three common sponge species was monitored histologically and by direct field observations of spawning events over 2 successive years at the reefs of Curaçao. Ircinia strobilina showed year round reproductive activity by the production of spermatic cysts in varying intensities in a major part of the population. Production of oocytes and larvae were only observed in the period from September through April, indicating an actual breeding season of 8 months a year. The sexes in this viviparous sponge seem to be separate, but protandry cannot be ruled out. Less than 10% of the sponge tissue was found to consist of reproductive elements. Neofibularia nolitangere is a gonochoristic oviparous sponge with a short annual breeding season of 2 months, in which two successive, highly predictable, short spawning periods occurred synchronously for the whole population. Up to half of the sponge tissue was transformed to reproductive elements. Agelas clathrodes showed low reproductive activity. Field observation suggests that this sponge is an oviparous hermaphrodite, probably annually releasing male and female gametes synchronously in a varying number of individuals of its population during a short breeding period. The variation in reproductive patterns in this small group of large massive coral reef sponges spans a range similar to that found in the morphologically highly variable group of stony corals and illustrates their ecological differentiation on the reef.

  18. First report on chitinous holdfast in sponges (Porifera).

    PubMed

    Ehrlich, Hermann; Kaluzhnaya, Oksana V; Tsurkan, Mikhail V; Ereskovsky, Alexander; Tabachnick, Konstantin R; Ilan, Micha; Stelling, Allison; Galli, Roberta; Petrova, Olga V; Nekipelov, Serguei V; Sivkov, Victor N; Vyalikh, Denis; Born, René; Behm, Thomas; Ehrlich, Andre; Chernogor, Lubov I; Belikov, Sergei; Janussen, Dorte; Bazhenov, Vasilii V; Wörheide, Gert

    2013-07-01

    A holdfast is a root- or basal plate-like structure of principal importance that anchors aquatic sessile organisms, including sponges, to hard substrates. There is to date little information about the nature and origin of sponges' holdfasts in both marine and freshwater environments. This work, to our knowledge, demonstrates for the first time that chitin is an important structural component within holdfasts of the endemic freshwater demosponge Lubomirskia baicalensis. Using a variety of techniques (near-edge X-ray absorption fine structure, Raman, electrospray ionization mas spectrometry, Morgan-Elson assay and Calcofluor White staining), we show that chitin from the sponge holdfast is much closer to α-chitin than to β-chitin. Most of the three-dimensional fibrous skeleton of this sponge consists of spicule-containing proteinaceous spongin. Intriguingly, the chitinous holdfast is not spongin-based, and is ontogenetically the oldest part of the sponge body. Sequencing revealed the presence of four previously undescribed genes encoding chitin synthases in the L. baicalensis sponge. This discovery of chitin within freshwater sponge holdfasts highlights the novel and specific functions of this biopolymer within these ancient sessile invertebrates. PMID:23677340

  19. Bioprospecting Sponge-Associated Microbes for Antimicrobial Compounds

    PubMed Central

    Indraningrat, Anak Agung Gede; Smidt, Hauke; Sipkema, Detmer

    2016-01-01

    Sponges are the most prolific marine organisms with respect to their arsenal of bioactive compounds including antimicrobials. However, the majority of these substances are probably not produced by the sponge itself, but rather by bacteria or fungi that are associated with their host. This review for the first time provides a comprehensive overview of antimicrobial compounds that are known to be produced by sponge-associated microbes. We discuss the current state-of-the-art by grouping the bioactive compounds produced by sponge-associated microorganisms in four categories: antiviral, antibacterial, antifungal and antiprotozoal compounds. Based on in vitro activity tests, identified targets of potent antimicrobial substances derived from sponge-associated microbes include: human immunodeficiency virus 1 (HIV-1) (2-undecyl-4-quinolone, sorbicillactone A and chartarutine B); influenza A (H1N1) virus (truncateol M); nosocomial Gram positive bacteria (thiopeptide YM-266183, YM-266184, mayamycin and kocurin); Escherichia coli (sydonic acid), Chlamydia trachomatis (naphthacene glycoside SF2446A2); Plasmodium spp. (manzamine A and quinolone 1); Leishmania donovani (manzamine A and valinomycin); Trypanosoma brucei (valinomycin and staurosporine); Candida albicans and dermatophytic fungi (saadamycin, 5,7-dimethoxy-4-p-methoxylphenylcoumarin and YM-202204). Thirty-five bacterial and 12 fungal genera associated with sponges that produce antimicrobials were identified, with Streptomyces, Pseudovibrio, Bacillus, Aspergillus and Penicillium as the prominent producers of antimicrobial compounds. Furthemore culture-independent approaches to more comprehensively exploit the genetic richness of antimicrobial compound-producing pathways from sponge-associated bacteria are addressed. PMID:27144573

  20. In vitro testing of Today vaginal contraceptive sponge with bacteria.

    PubMed

    Hammill, H A; Ford, L C; Suzuki, F; Mickus, K; Yip, D; Finegold, S

    1986-01-01

    In vitro methods were used to test Today vaginal contraceptive sponges for sterility, contamination by handling, and inhibition of bacterial growth. Also tested was an in vitro vaginal model surrounded by growth medium that continually seeded the dialysis tubing with nutrient in an attempt to replicate vaginal secretions. A goal of this research was to investigate manufacturer claims of hostility of the sponge in the presence of Staph aureus. Sponges added in a sterile manner to brain-heart infusion broth produced no growth under aerobic or anaerobic conditions when no organisms were added. However, the experiments that involved contamination of the sponges by hadling in a nonsterile fashion resulted in 10.8 colony forming units of Staph epidermidis and Staph aureus, coagulese negative. In the in vitro vaginal model, 16 hours after an inoculum of Staph aureus colony forming units was placed on a sponge, 3.5 x 10.10 colony forming units were cultured and there was a similar profusion of E coli sludge. These results fail to confirm claims of hostility of the vaginal sponge to the bacteria tested. There is concern that the technique recommended by the manufacturer involves adding water and then inserting the sponge with 1 hand and leaving it in place for 24 hours. This procedure may facilitate the enhancement of vaginitis and perhaps pelvic inflammatory disease. PMID:12341136

  1. Unidirectional perfect absorber.

    PubMed

    Jin, L; Wang, P; Song, Z

    2016-01-01

    This study proposes a unidirectional perfect absorber (UPA), which we realized with a two-arm Aharonov-Bohm interferometer, that consists of a dissipative resonator side-coupled to a uniform resonator array. The UPA has reflection-less full absorption on one direction, and reflectionless full transmission on the other, with an appropriate magnetic flux and coupling, detuning, and loss of the side-coupled resonator. The magnetic flux controls the transmission, the left transmission is larger for magnetic flux less than one-half flux quantum; and the right transmission is larger for magnetic flux between one-half and one flux quantum. Besides, a perfect absorber (PA) can be realized based on the UPA, in which light waves from both sides, with arbitrary superposition of the ampli- tude and phase, are perfectly absorbed. The UPA is expected to be useful in the design of novel optical devices. PMID:27615125

  2. HPLC method to characterize cyanogen bromide collagen fractions containing pyridinoline groups.

    PubMed

    Bruno, R; Mazza, R; Calafiori, A R; Covello, C; Falbo, L; Martino, G; Marotta, M

    1997-01-01

    The HPLC method here described allows to separate CNBr collagen peptides within 2.5 h by reversed phase and gradient elution. The method is useful to determine both peptide bond and pyridinoline groups by absorbance spectophotometry. The fractions can be recovered and then submitted to other characterization techniques. PMID:10327703

  3. Depth-related alkaloid variation in Mediterranean Aplysina sponges.

    PubMed

    Putz, Annika; Kloeppel, Anne; Pfannkuchen, Martin; Brümmer, Franz; Proksch, Peter

    2009-01-01

    Total amounts and patterns of bromoisoxazoline alkaloids of Aplysina sponges from Croatia (Mediterranean Sea) were analyzed along an underwater slope ranging from 1.8 to 38.5 m. Total amounts of alkaloids varied from sample to sample and showed no correlation with depth. In contrast, striking differences of alkaloid patterns were found between sponges from shallow sites (1.8-11.8 m) and those collected from deeper sites (11.8-38.5 m). Sponges from shallow depths consistently exhibited alkaloid patterns typical for Aplysina aerophoba with aerophobin-2 (2) and isofistularin-3 (3) as main constituents. Sponges from deeper sites (below 11.8 m) resembled Aplysina cavernicola with aerothionin (4) and aplysinamisin-1 (1) as major compounds. The typical A. cavernicola pigment 3,4-dihydroxyquinoline-2-carboxylic acid (6), however, could not be detected in A. aerophoba sponges but was replaced by the A. aerophoba pigment uranidine (5) which appeared to be present in all sponge samples analyzed. During transplantation experiments sponges from sites below 30 m featuring the A. cavernicola chemotype of bromoisoxazoline alkaloids were translocated to shallower habitats (10 m). The alkaloid patterns in transplanted sponges were found to be stable over a period of 12 months and unaffected by this change in depth. In a further experiment, clones of Aplysina sponges from shallow depths of 5-6 m resembling the A. aerophoba chemotype were either kept in situ under natural light conditions or artificially shaded by excluding photosynthetically active radiation (PAR). Neither 4 nor 1 were detected in artificially shaded sponges over an observation period of 12 months. In summary, two chemically distinct types of Aplysina sponges were discovered in this study that proved to be remarkably stable with regard to the bromoisoxazoline patterns and unaffected either by changing the light conditions or depth. It is not clear presently whether the Aplysina sponges collected from depths < 11.8 m

  4. Nonlinear microscopy of collagen fibers

    NASA Astrophysics Data System (ADS)

    Strupler, M.; Pena, A.-M.; Hernest, M.; Tharaux, P.-L.; Fabre, A.; Marchal-Somme, J.; Crestani, B.; Débarre, D.; Martin, J.-L.; Beaurepaire, E.; Schanne-Klein, M.-C.

    2007-02-01

    We used intrinsic Second Harmonic Generation (SHG) by fibrillar collagen to visualize the three-dimensional architecture of collagen fibrosis at the micrometer scale using laser scanning nonlinear microscopy. We showed that SHG signals are highly specific to fibrillar collagen and provide a sensitive probe of the micrometer-scale structural organization of collagen in tissues. Moreover, recording simultaneously other nonlinear optical signals in a multimodal setup, we visualized the tissue morphology using Two-Photon Excited Fluorescence (2PEF) signals from endogenous chromophores such as NADH or elastin. We then compared different methods to determine accurate indexes of collagen fibrosis using nonlinear microscopy, given that most collagen fibrils are smaller than the microscope resolution and that second harmonic generation is a coherent process. In order to define a robust method to process our three-dimensional images, we either calculated the fraction of the images occupied by a significant SHG signal, or averaged SHG signal intensities. We showed that these scores provide an estimation of the extension of renal and pulmonary fibrosis in murine models, and that they clearly sort out the fibrotic mice.

  5. Human collagen produced in plants

    PubMed Central

    Shoseyov, Oded; Posen, Yehudit; Grynspan, Frida

    2014-01-01

    Consequential to its essential role as a mechanical support and affinity regulator in extracellular matrices, collagen constitutes a highly sought after scaffolding material for regeneration and healing applications. However, substantiated concerns have been raised with regard to quality and safety of animal tissue-extracted collagen, particularly in relation to its immunogenicity, risk of disease transmission and overall quality and consistency. In parallel, contamination with undesirable cellular factors can significantly impair its bioactivity, vis-a-vis its impact on cell recruitment, proliferation and differentiation. High-scale production of recombinant human collagen Type I (rhCOL1) in the tobacco plant provides a source of an homogenic, heterotrimeric, thermally stable “virgin” collagen which self assembles to fine homogenous fibrils displaying intact binding sites and has been applied to form numerous functional scaffolds for tissue engineering and regenerative medicine. In addition, rhCOL1 can form liquid crystal structures, yielding a well-organized and mechanically strong membrane, two properties indispensable to extracellular matrix (ECM) mimicry. Overall, the shortcomings of animal- and cadaver-derived collagens arising from their source diversity and recycled nature are fully overcome in the plant setting, constituting a collagen source ideal for tissue engineering and regenerative medicine applications. PMID:23941988

  6. Characterisations of collagen-silver-hydroxyapatite nanocomposites

    NASA Astrophysics Data System (ADS)

    Ciobanu, C. S.; Popa, C. L.; Petre, C. C.; Jiga, G.; Trusca, R.; Predoi, D.

    2016-05-01

    The XRD analysis were performed to confirm the formation of hydroxyapatite structure in collagen-silver-hydroxyapatite nanocomposites. The molecular interaction in collagen-hydroxyapatite nanocomposites was highlighted by Fourier transform infrared spectroscopy (FTIR) analysis. The SEM showed a nanostructure of collagen-silverhydroxyapatite nanocomposites composed of nano needle-like particles in a veil with collagen texture. The presence of vibrational groups characteristics to the hydroxyapatite structure in collagen-silver-hydroxyapatite (AgHApColl) nanocomposites was investigated by FTIR.

  7. Multiple-layer Radiation Absorber

    NASA Astrophysics Data System (ADS)

    Baker, Robert M. L.; Baker, Bonnie Sue

    A structure is discussed for absorbing incident radiation, either electromagnetic (EM) or sound. Such a surface structure is needed, for example, in a highly sensitive high-frequency gravitational wave or HFGW detector such as the Li-Baker. The multi-layer absorber, which is discussed, is constructed with metamaterial [MM] layer or layers on top. This MM is configured for a specific EM or sound radiation frequency band, which absorbs incident EM or sound radiation without reflection. Below these top MM layers is a substrate of conventional EM-radiation absorbing or acoustical absorbing reflective material, such as an array of pyramidal foam absorbers. Incident radiation is partially absorbed by the MM layer or layers, and then it is more absorbed by the lower absorbing and reflecting substrate. The remaining reflected radiation is even further absorbed by the MM layers on its "way out_ so that essentially all of the incident radiation is absorbed _ a nearly perfect black-body absorber. In a HFGW detector a substrate, such as foam absorbers, may outgas into a high vacuum and reduce the capability of the vacuum-producing equipment, however, the layers above this lowest substrate will seal the absorbing and reflecting substrate from any external vacuum. The layers also serve to seal the absorbing material against air or water flow past the surfaces of aircraft, watercraft or submarines. Other applications for such a multiple-level radiation absorber include stealth aircraft, missiles and submarines.

  8. Neutron Absorbing Alloys

    DOEpatents

    Mizia, Ronald E.; Shaber, Eric L.; DuPont, John N.; Robino, Charles V.; Williams, David B.

    2004-05-04

    The present invention is drawn to new classes of advanced neutron absorbing structural materials for use in spent nuclear fuel applications requiring structural strength, weldability, and long term corrosion resistance. Particularly, an austenitic stainless steel alloy containing gadolinium and less than 5% of a ferrite content is disclosed. Additionally, a nickel-based alloy containing gadolinium and greater than 50% nickel is also disclosed.

  9. Managing and sharing the escalating number of sponge "unknowns": the SpongeMaps project.

    PubMed

    Hooper, J N A; Hall, K A; Ekins, M; Erpenbeck, D; Wörheide, G; Jolley-Rogers, G

    2013-09-01

    Contemporary collections of sponges in the Indo-west Pacific have escalated substantially due to pharmaceutical discovery, national bioregional planning, and compliance with international conventions on the seabed and its marine genetic resources beyond national jurisdictions. These partially processed operational taxonomic unit (OTU) collections now vastly outweigh the expertise available to make them better "known" via complete taxonomy, yet for many bioregions they represent the most significant body of currently available knowledge. Increasing numbers of cryptic species, previously undetected morphologically, are now being discovered by molecular and chemical analyses. The uncoordinated and fragmented nature of many previous collections, however, means that knowledge and expertise gained from a particular project are often lost to future projects without a biodiversity informatics legacy. Integrating these diverse data (GIS; OTUs; images; molecular, chemical, and other datasets) required a two-way iterative process so far unavailable for sponges with existing biodiversity informatics tools. SpongeMaps arose from the initial need for online collaboration to integrate morphometric data with molecular barcodes, including the Porifera Tree of Life (PorTol) project. It provides interrogation of existing data to better process new collections; capacity to create new OTUs; publication of online pages for individual species, so as to interpret GIS and other data for online biodiversity databases and services; and automatic links to external datasets for taxonomic hierarchy, specimen GIS and mapping, DNA sequence data, chemical structures, and images. PMID:23652200

  10. Dynamic finite element simulation of the gunshot injury to the human forehead protected by polyvinyl alcohol sponge.

    PubMed

    Karimi, Alireza; Razaghi, Reza; Navidbakhsh, Mahdi; Sera, Toshihiro; Kudo, Susumu

    2016-04-01

    Although there are some traditional models of the gunshot wounds, there is still a need for more modeling analyses due to the difficulties related to the gunshot wounds to the forehead region of the human skull. In this study, the degree of damage as a consequence of penetrating head injuries due to gunshot wounds was determined using a preliminary finite element (FE) model of the human skull. In addition, the role of polyvinyl alcohol (PVA) sponge, which can be used as an alternative to reinforce the kinetic energy absorption capacity of bulletproof vest and helmet materials, to minimize the amount of skull injury due to penetrating processes was investigated through the FE model. Digital computed tomography along with magnetic resonance imaging data of the human head were employed to launch a three-dimensional (3D) FE model of the skull. Two geometrical shapes of projectiles (steel ball and bullet) were simulated for penetrating with an initial impact velocity of 734 m/s using nonlinear dynamic modeling code, namely LS-DYNA. The role of the damaged/distorted elements were removed during computation when the stress or strain reached their thresholds. The stress distributions in various parts of the forehead and sponge after injury were also computed. The results revealed the same amount of stress for both the steel ball and bullet after hitting the skull. The modeling results also indicated the time that steel ball takes to penetrate into the skull is lower than that of the bullet. In addition, more than 21% of the steel ball's kinetic energy was absorbed by the PVA sponge and, subsequently, injury sternness of the forehead was considerably minimized. The findings advise the application of the PVA sponge as a substitute strengthening material to be able to diminish the energy of impact as well as the load transmitted to the object. PMID:26886822

  11. New and extraordinary Early Cambrian sponge spicule assemblage from China

    NASA Astrophysics Data System (ADS)

    Zhang, Xi-Guang; Pratt, Brian R.

    1994-01-01

    The fossil record of siliceous sponges, compared with that of other skeleton- secreting Metazoa, is poorly known, based as it is on disarticulated spicules and sporadically preserved body fossils. Abundant spicules recovered from Lower Cambrian strata in Shaanxi, China, essentially double the known morphological diversity of siliceous sponges for that interval of geologic time. These fossils, along with a comparable coeval fauna from South Australia, have a remarkably modern aspect, thereby demonstrating that the principal siliceous sponge groups and styles of body architecture were established quickly in the earliest Phanerozoic as part of the Cambrian "explosion" and that they inhabited a variety of low-energy, relatively deep water settings. The similarity of spicule shape and variation to that of younger assemblages reflects a conservative architecture for the siliceous sponges.

  12. Protonated Melamine Sponge for Effective Oil/Water Separation

    PubMed Central

    Wang, Chih-Feng; Huang, Hsiang-Ching; Chen, Liang-Ting

    2015-01-01

    In this study, we fabricated a superhydrophilic and underwater superoleophobic protonated melamine sponge for effective separation of water-rich immiscible oil/water mixtures with extremely high separation efficiency. This protonated melamine sponge exhibited excellent antifouling properties and could be used to separate oil/water mixtures continuously for up to 12 h without any increase in the oil content in filtrate. Moreover, our compressed protonated melamine sponge could separate both surfactant-free and -stabilized oil-in-water emulsions with high separation efficiencies. The high performance of this protonated melamine sponge and its efficient, energy- and cost-effective preparation suggest that it has great potential for use in practical applications. PMID:26399444

  13. Diversity, structure and convergent evolution of the global sponge microbiome.

    PubMed

    Thomas, Torsten; Moitinho-Silva, Lucas; Lurgi, Miguel; Björk, Johannes R; Easson, Cole; Astudillo-García, Carmen; Olson, Julie B; Erwin, Patrick M; López-Legentil, Susanna; Luter, Heidi; Chaves-Fonnegra, Andia; Costa, Rodrigo; Schupp, Peter J; Steindler, Laura; Erpenbeck, Dirk; Gilbert, Jack; Knight, Rob; Ackermann, Gail; Victor Lopez, Jose; Taylor, Michael W; Thacker, Robert W; Montoya, Jose M; Hentschel, Ute; Webster, Nicole S

    2016-01-01

    Sponges (phylum Porifera) are early-diverging metazoa renowned for establishing complex microbial symbioses. Here we present a global Porifera microbiome survey, set out to establish the ecological and evolutionary drivers of these host-microbe interactions. We show that sponges are a reservoir of exceptional microbial diversity and major contributors to the total microbial diversity of the world's oceans. Little commonality in species composition or structure is evident across the phylum, although symbiont communities are characterized by specialists and generalists rather than opportunists. Core sponge microbiomes are stable and characterized by generalist symbionts exhibiting amensal and/or commensal interactions. Symbionts that are phylogenetically unique to sponges do not disproportionally contribute to the core microbiome, and host phylogeny impacts complexity rather than composition of the symbiont community. Our findings support a model of independent assembly and evolution in symbiont communities across the entire host phylum, with convergent forces resulting in analogous community organization and interactions. PMID:27306690

  14. Aplyzanzine A, a new dibromotyrosine derivative from a Verongida sponge.

    PubMed

    Evan, T; Rudi, A; Ilan, M; Kashman, Y

    2001-02-01

    Aplyzanzine A (1), a novel bisdibromotyrosine derivative, has been isolated from the Indo-Pacific sponge Aplysina sp. Its structure was elucidated mainly on the basis of 1D and 2D NMR and MS spectroscopic data. PMID:11430007

  15. Calafianin, a bromotyrosine derivative from the marine sponge Aplysina gerardogreeni.

    PubMed

    Encarnación, R D; Sandoval, E; Malmstrøm, J; Christophersen, C

    2000-06-01

    Calafianin (1) and two known compounds, aerothionin and (3, 5-dibromo-2-hydroxy-4-methoxyphenyl)acetic acid, were isolated from the marine sponge Aplysina gerardogreeni. The structure of 1 was determined by NMR analysis and mass spectrometry. PMID:10869226

  16. Protonated Melamine Sponge for Effective Oil/Water Separation.

    PubMed

    Wang, Chih-Feng; Huang, Hsiang-Ching; Chen, Liang-Ting

    2015-01-01

    In this study, we fabricated a superhydrophilic and underwater superoleophobic protonated melamine sponge for effective separation of water-rich immiscible oil/water mixtures with extremely high separation efficiency. This protonated melamine sponge exhibited excellent antifouling properties and could be used to separate oil/water mixtures continuously for up to 12 h without any increase in the oil content in filtrate. Moreover, our compressed protonated melamine sponge could separate both surfactant-free and -stabilized oil-in-water emulsions with high separation efficiencies. The high performance of this protonated melamine sponge and its efficient, energy- and cost-effective preparation suggest that it has great potential for use in practical applications. PMID:26399444

  17. Protonated Melamine Sponge for Effective Oil/Water Separation

    NASA Astrophysics Data System (ADS)

    Wang, Chih-Feng; Huang, Hsiang-Ching; Chen, Liang-Ting

    2015-09-01

    In this study, we fabricated a superhydrophilic and underwater superoleophobic protonated melamine sponge for effective separation of water-rich immiscible oil/water mixtures with extremely high separation efficiency. This protonated melamine sponge exhibited excellent antifouling properties and could be used to separate oil/water mixtures continuously for up to 12 h without any increase in the oil content in filtrate. Moreover, our compressed protonated melamine sponge could separate both surfactant-free and -stabilized oil-in-water emulsions with high separation efficiencies. The high performance of this protonated melamine sponge and its efficient, energy- and cost-effective preparation suggest that it has great potential for use in practical applications.

  18. Diversity, structure and convergent evolution of the global sponge microbiome

    PubMed Central

    Thomas, Torsten; Moitinho-Silva, Lucas; Lurgi, Miguel; Björk, Johannes R.; Easson, Cole; Astudillo-García, Carmen; Olson, Julie B.; Erwin, Patrick M.; López-Legentil, Susanna; Luter, Heidi; Chaves-Fonnegra, Andia; Costa, Rodrigo; Schupp, Peter J.; Steindler, Laura; Erpenbeck, Dirk; Gilbert, Jack; Knight, Rob; Ackermann, Gail; Victor Lopez, Jose; Taylor, Michael W.; Thacker, Robert W.; Montoya, Jose M.; Hentschel, Ute; Webster, Nicole S.

    2016-01-01

    Sponges (phylum Porifera) are early-diverging metazoa renowned for establishing complex microbial symbioses. Here we present a global Porifera microbiome survey, set out to establish the ecological and evolutionary drivers of these host–microbe interactions. We show that sponges are a reservoir of exceptional microbial diversity and major contributors to the total microbial diversity of the world's oceans. Little commonality in species composition or structure is evident across the phylum, although symbiont communities are characterized by specialists and generalists rather than opportunists. Core sponge microbiomes are stable and characterized by generalist symbionts exhibiting amensal and/or commensal interactions. Symbionts that are phylogenetically unique to sponges do not disproportionally contribute to the core microbiome, and host phylogeny impacts complexity rather than composition of the symbiont community. Our findings support a model of independent assembly and evolution in symbiont communities across the entire host phylum, with convergent forces resulting in analogous community organization and interactions. PMID:27306690

  19. Heterogeneity of Collagen VI Microfibrils

    PubMed Central

    Maaß, Tobias; Bayley, Christopher P.; Mörgelin, Matthias; Lettmann, Sandra; Bonaldo, Paolo; Paulsson, Mats; Baldock, Clair; Wagener, Raimund

    2016-01-01

    Collagen VI, a collagen with uncharacteristically large N- and C-terminal non-collagenous regions, forms a distinct microfibrillar network in most connective tissues. It was long considered to consist of three genetically distinct α chains (α1, α2, and α3). Intracellularly, heterotrimeric molecules associate to form dimers and tetramers, which are then secreted and assembled to microfibrils. The identification of three novel long collagen VI α chains, α4, α5, and α6, led to the question if and how these may substitute for the long α3 chain in collagen VI assembly. Here, we studied structural features of the novel long chains and analyzed the assembly of these into tetramers and microfibrils. N- and C-terminal globular regions of collagen VI were recombinantly expressed and studied by small angle x-ray scattering (SAXS). Ab initio models of the N-terminal globular regions of the α4, α5, and α6 chains showed a C-shaped structure similar to that found for the α3 chain. Single particle EM nanostructure of the N-terminal globular region of the α4 chain confirmed the C-shaped structure revealed by SAXS. Immuno-EM of collagen VI extracted from tissue revealed that like the α3 chain the novel long chains assemble to homotetramers that are incorporated into mixed microfibrils. Moreover, SAXS models of the C-terminal globular regions of the α1, α2, α4, and α6 chains were generated. Interestingly, the α1, α2, and α4 C-terminal globular regions dimerize. These self-interactions may play a role in tetramer formation. PMID:26742845

  20. Nanomechanics of Type I Collagen.

    PubMed

    Varma, Sameer; Orgel, Joseph P R O; Schieber, Jay D

    2016-07-12

    Type I collagen is the predominant collagen in mature tendons and ligaments, where it gives them their load-bearing mechanical properties. Fibrils of type I collagen are formed by the packing of polypeptide triple helices. Higher-order structures like fibril bundles and fibers are assembled from fibrils in the presence of other collagenous molecules and noncollagenous molecules. Curiously, however, experiments show that fibrils/fibril bundles are less resistant to axial stress compared to their constituent triple helices-the Young's moduli of fibrils/fibril bundles are an order-of-magnitude smaller than the Young's moduli of triple helices. Given the sensitivity of the Young's moduli of triple helices to solvation environment, a plausible explanation is that the packing of triple helices into fibrils perhaps reduces the Young's modulus of an individual triple helix, which results in fibrils having smaller Young's moduli. We find, however, from molecular dynamics and accelerated conformational sampling simulations that the Young's modulus of the buried core of the fibril is of the same order as that of a triple helix in aqueous phase. These simulations, therefore, suggest that the lower Young's moduli of fibrils/fibril bundles cannot be attributed to the specific packing of triple helices in the fibril core. It is not the fibril core that yields initially to axial stress. Rather, it must be the portion of the fibril exposed to the solvent and/or the fibril-fibril interface that bears the initial strain. Overall, this work provides estimates of Young's moduli and persistence lengths at two levels of collagen's structural assembly, which are necessary to quantitatively investigate the response of various biological factors on collagen mechanics, including congenital mutations, posttranslational modifications and ligand binding, and also engineer new collagen-based materials. PMID:27410733

  1. Meroterpenoids from a Tropical Dysidea sp. Sponge.

    PubMed

    Kim, Chang-Kwon; Woo, Jung-Kyun; Kim, Seong-Hwan; Cho, Eunji; Lee, Yeon-Ju; Lee, Hyi-Seung; Sim, Chung J; Oh, Dong-Chan; Oh, Ki-Bong; Shin, Jongheon

    2015-11-25

    Six new meroterpenoids (1-6), along with arenarol (7), a known rearranged drimane sesquiterpene hydroquinone, were isolated from a Dysidea sp. sponge collected from the Federated States of Micronesia. On the basis of the results of combined spectroscopic analysis, compound 1 was determined to be the cyclic ether derivative of 7, whereas 2 and 3 were assigned as the corresponding sesquiterpene quinones containing taurine-derived substituents. Compounds 4-6 possess a novel tetracyclic skeleton formed by a direct linkage between the quinone and sesquiterpene moieties. The configurations of these new compounds were assigned on the basis of combined NOESY and ECD analysis. These compounds exhibited cytotoxic and antimicrobial activities and weak inhibition against Na(+)/K(+)-ATPase. PMID:26551342

  2. Elastic, Conductive, Polymeric Hydrogels and Sponges

    NASA Astrophysics Data System (ADS)

    Lu, Yun; He, Weina; Cao, Tai; Guo, Haitao; Zhang, Yongyi; Li, Qingwen; Shao, Ziqiang; Cui, Yulin; Zhang, Xuetong

    2014-07-01

    As a result of inherent rigidity of the conjugated macromolecular chains resulted from the delocalized π-electron system along the polymer backbone, it has been a huge challenge to make conducting polymer hydrogels elastic by far. Herein elastic and conductive polypyrrole hydrogels with only conducting polymer as the continuous phase have been simply synthesized in the indispensable conditions of 1) mixed solvent, 2) deficient oxidant, and 3) monthly secondary growth. The elastic mechanism and oxidative polymerization mechanism on the resulting PPy hydrogels have been discussed. The resulting hydrogels show some novel properties, e.g., shape memory elasticity, fast functionalization with various guest objects, and fast removal of organic infectants from aqueous solutions, all of which cannot be observed from traditional non-elastic conducting polymer counterparts. What's more, light-weight, elastic, and conductive organic sponges with excellent stress-sensing behavior have been successfully achieved via using the resulting polypyrrole hydrogels as precursors.

  3. Elastic, Conductive, Polymeric Hydrogels and Sponges

    PubMed Central

    Lu, Yun; He, Weina; Cao, Tai; Guo, Haitao; Zhang, Yongyi; Li, Qingwen; Shao, Ziqiang; Cui, Yulin; Zhang, Xuetong

    2014-01-01

    As a result of inherent rigidity of the conjugated macromolecular chains resulted from the delocalized π-electron system along the polymer backbone, it has been a huge challenge to make conducting polymer hydrogels elastic by far. Herein elastic and conductive polypyrrole hydrogels with only conducting polymer as the continuous phase have been simply synthesized in the indispensable conditions of 1) mixed solvent, 2) deficient oxidant, and 3) monthly secondary growth. The elastic mechanism and oxidative polymerization mechanism on the resulting PPy hydrogels have been discussed. The resulting hydrogels show some novel properties, e.g., shape memory elasticity, fast functionalization with various guest objects, and fast removal of organic infectants from aqueous solutions, all of which cannot be observed from traditional non-elastic conducting polymer counterparts. What's more, light-weight, elastic, and conductive organic sponges with excellent stress-sensing behavior have been successfully achieved via using the resulting polypyrrole hydrogels as precursors. PMID:25052015

  4. Enhanced stabilization of collagen by furfural.

    PubMed

    Lakra, Rachita; Kiran, Manikantan Syamala; Usha, Ramamoorthy; Mohan, Ranganathan; Sundaresan, Raja; Korrapati, Purna Sai

    2014-04-01

    Furfural (2-furancarboxaldehyde), a product derived from plant pentosans, has been investigated for its interaction with collagen. Introduction of furfural during fibril formation enhanced the thermal and mechanical stability of collagen. Collagen films treated with furfural exhibited higher denaturation temperature (Td) (p<0.04) and showed a 3-fold increase in Young's modulus (p<0.04) at higher concentration. Furfural and furfural treated collagen films did not have any cytotoxic effect. Rheological characterization showed an increase in shear stress and shear viscosity with increasing shear rate for treated collagen. Circular dichroism (CD) studies indicated that the furfural did not have any impact on triple helical structure of collagen. Scanning electron microscopy (SEM) of furfural treated collagen exhibited small sized porous structure in comparison with untreated collagen. Thus this study provides an alternate ecologically safe crosslinking agent for improving the stability of collagen for biomedical and industrial applications. PMID:24468046

  5. Molecular biodiversity. Case study: Porifera (sponges).

    PubMed

    Müller, Werner E G; Brümmer, Franz; Batel, Renato; Müller, Isabel M; Schröder, Heinz C

    2003-03-01

    Biological diversity--or biodiversity--is the term given to the variety of life on Earth and the natural patterns it forms. The biodiversity we see today is the fruit of billions of years of evolution, shaped by natural processes and, increasingly, by the influence of humans. It forms the web of life of which we are an integral part and upon which we so fully depend. The research on molecular biodiversity tries to lay the scientific foundation of a rational conservation policy that has its roots in various disciplines including systematics/taxonomy (species richness), present day ecology (diversity of ecological systems), and functional genetics (genetic diversity). The results of ongoing genome analyses (genome projects and expressed sequence tag projects) and the achievements of molecular evolution may allow us not only to quantitate the diversity of the present biota but also to extrapolate to their diversification in the future. A link between biodiversity and genomics/molecular evolution will create a platform which we hope may facilitate a sustainable management of organismic life and ensure its exploitation for human benefit. In the present review we outline possible strategies, using the Porifera (sponges) as a prominent example. On the basis of solid taxonomy and ecological data, the high value of this phylum for human application becomes obvious, especially with regard to the field of chemical ecology and the desire to find novel potential drugs for clinical use. In addition, the benefit of trying to make sense of molecular biodiversity using sponges as an example can be seen in the fact that the study of these animals, which are "living fossils", gives us a good insight into the history of our planet, especially with respect to the evolution of Metazoa. PMID:12649752

  6. Genomics of "Candidatus Synechococcus spongiarium", a Cyanobacterial Sponge Symbiont

    SciTech Connect

    Slaby, Beate M.; Copeland, Alex; Woyke, Tanja; Hentschel, Ute

    2014-03-21

    Marine sponges (Porifera): ancient metazoans of ecological importance, that produce bioactive secondary metabolites and interact with various microorganisms including cyanobacteria1: Marine Synechococcus spp.: cyanobacteria, important contributors to the global carbon cycle and major primary producers in the oceans2 Ca. S. spongiarum: an ecotype of this genus, widespread and abundant symbiont of various marine sponges around the world3, e.g. Aplysina aerophoba

  7. Epidermabrasion for acne: the polyester fiber web sponge.

    PubMed

    Durr, N P; Orentreich, N

    1976-03-01

    Physical-mechanical exfoliation with the nonwoven polyester fiber web sponge is an effective adjunct to the treatment of comedonal and pustular acne. Precisely controlled epidermabrasion is achieved by varying pressure, velocity, duration and frequency of use. Side effects are negligible and patient acceptance is high. Effectiveness is not dependent upon erythema and scaling since the web sponge mechanically removes keratin excrescences and trapped hairs in pilosebaceous ducts. PMID:138554

  8. Chemical defense of Mediterranean sponges Aplysina cavernicola and Aplysina aerophoba.

    PubMed

    Thoms, Carsten; Wolff, Matthias; Padmakumar, K; Ebel, Rainer; Proksch, Peter

    2004-01-01

    The Mediterranean sponges Aplysina aerophoba and A. cavernicola accumulate brominated isoxazoline alkaloids including aplysinamisin-1 (1), aerophobin-2 (2), isofistularin-3 (3) or aerothionin (4) at concentrations up to 10% of their respective dry weights. In laboratory feeding experiments employing the polyphagous Mediterranean fish Blennius sphinx crude extracts of both Aplysina sponges were incorporated into artificial fish food at their physiological concentrations (based on volume) and offered to B. sphinx in choice feeding experiments against untreated control food. In addition to the Aplysina sponges, extracts from nine other frequently occurring Mediterranean sponges were likewise included into the experiments. Both Aplysina species elicited strong feeding deterrence compared to the other sponges tested. Bioassay-guided fractionation of A. cavernicola yielded the isoxazoline alkaloids aerothionin (4) and aplysinamisin-1 (1) as well as the 3,4-dihydroxyquinoline-2-carboxylic acid (8) as major deterrent constituents when tested at their physiological concentrations as present in sponges. Aeroplysinin-1 (5) and dienone (6), however, which are formed in A. aerophoba and A. cavernicola from isoxazoline precursors through bioconversion reactions upon tissue injury showed no or only little deterrent activity. Fractionation of a crude extract of A. aerophoba yielded aerophobin-2 (2) and isofistularin-3 (3) as major deterrent constituents against B. sphinx. We propose that the isoxazoline alkaloids 1-4 of Mediterranean Aplysina sponges as well as the 3,4-dihydroxyquinoline-2-carboxylic acid (8) (in the case of A. cavernicola) act as defensive metabolites against B. sphinx and possibly also against other predators while the antibiotically active bioconversion products aeroplysinin-1 (5) and dienone (6) may protect sponges from invasion of bacterial pathogens. PMID:15018063

  9. Osteogenic differentiation of preosteoblasts on a hemostatic gelatin sponge.

    PubMed

    Kuo, Zong-Keng; Lai, Po-Liang; Toh, Elsie Khai-Woon; Weng, Cheng-Hsi; Tseng, Hsiang-Wen; Chang, Pei-Zen; Chen, Chih-Chen; Cheng, Chao-Min

    2016-01-01

    Bone tissue engineering provides many advantages for repairing skeletal defects. Although many different kinds of biomaterials have been used for bone tissue engineering, safety issues must be considered when using them in a clinical setting. In this study, we examined the effects of using a common clinical item, a hemostatic gelatin sponge, as a scaffold for bone tissue engineering. The use of such a clinically acceptable item may hasten the translational lag from laboratory to clinical studies. We performed both degradation and biocompatibility studies on the hemostatic gelatin sponge, and cultured preosteoblasts within the sponge scaffold to demonstrate its osteogenic differentiation potential. In degradation assays, the gelatin sponge demonstrated good stability after being immersed in PBS for 8 weeks (losing only about 10% of its net weight and about 54% decrease of mechanical strength), but pepsin and collagenases readily biodegraded it. The gelatin sponge demonstrated good biocompatibility to preosteoblasts as demonstrated by MTT assay, confocal microscopy, and scanning electron microscopy. Furthermore, osteogenic differentiation and the migration of preosteoblasts, elevated alkaline phosphatase activity, and in vitro mineralization were observed within the scaffold structure. Each of these results indicates that the hemostatic gelatin sponge is a suitable scaffold for bone tissue engineering. PMID:27616161

  10. Bio-inspired Aloe vera sponges for biomedical applications.

    PubMed

    Silva, S S; Oliveira, M B; Mano, J F; Reis, R L

    2014-11-01

    Chemical composition and biological properties of Aloe vera (AV), a tropical plant, explain its potential use for cosmetic, nutritional and biomedical applications. AV gel present in AV leaves is rich in several compounds, nutrients and polysaccharides. This work proposes using AV gel complex structure and chemical composition, associated with freeze-drying, to produce sponges. To increase the structures stability in aqueous media, a thin coating of gellan gum (GG), was applied onto AV gel. AV-based sponges showed a heterogeneous porous formation, interconnected pores and good porosity (72-77%). The coating with a GG layer onto AV influenced the stability, swelling behavior and mechanical properties of the resulting sponges. Moreover, sponges provided the sustained release of BSA-FTIC, used as a model protein, over 3 weeks. Also, in vitro cell culture studies evidenced that sponges are not cytotoxic for a mouse fibroblast-like cell line. Therefore, developed AV-based sponges have potential use in biomedical applications. PMID:25129743

  11. First report on chitinous holdfast in sponges (Porifera)

    PubMed Central

    Ehrlich, Hermann; Kaluzhnaya, Oksana V.; Tsurkan, Mikhail V.; Ereskovsky, Alexander; Tabachnick, Konstantin R.; Ilan, Micha; Stelling, Allison; Galli, Roberta; Petrova, Olga V.; Nekipelov, Serguei V.; Sivkov, Victor N.; Vyalikh, Denis; Born, René; Behm, Thomas; Ehrlich, Andre; Chernogor, Lubov I.; Belikov, Sergei; Janussen, Dorte; Bazhenov, Vasilii V.; Wörheide, Gert

    2013-01-01

    A holdfast is a root- or basal plate-like structure of principal importance that anchors aquatic sessile organisms, including sponges, to hard substrates. There is to date little information about the nature and origin of sponges’ holdfasts in both marine and freshwater environments. This work, to our knowledge, demonstrates for the first time that chitin is an important structural component within holdfasts of the endemic freshwater demosponge Lubomirskia baicalensis. Using a variety of techniques (near-edge X-ray absorption fine structure, Raman, electrospray ionization mas spectrometry, Morgan–Elson assay and Calcofluor White staining), we show that chitin from the sponge holdfast is much closer to α-chitin than to β-chitin. Most of the three-dimensional fibrous skeleton of this sponge consists of spicule-containing proteinaceous spongin. Intriguingly, the chitinous holdfast is not spongin-based, and is ontogenetically the oldest part of the sponge body. Sequencing revealed the presence of four previously undescribed genes encoding chitin synthases in the L. baicalensis sponge. This discovery of chitin within freshwater sponge holdfasts highlights the novel and specific functions of this biopolymer within these ancient sessile invertebrates. PMID:23677340

  12. Trophic transfer of radioisotopes in Mediterranean sponges through bacteria consumption.

    PubMed

    Lacoue-Labarthe, Thomas; Warnau, Michel; Beaugeard, Laureen; Pascal, Pierre-Yves

    2016-02-01

    Numerous field studies highlighted the capacities of marine sponges to bioaccumulate trace elements and assessed their potential as biomonitors of the marine environment. Experimental works demonstrated that dissolved metals and radionuclides can be taken up directly by sponge tissues but, to the best of our knowledge, little is known on the contribution of the dietary pathway through the consumption of contaminated bacteria considered as one of the trophic source in sponge diet. Objectives of this work are to study trophic transfer of radiotracers (110m)Ag, (241)Am, (109)Cd, (57)Co, (134)Cs, (54)Mn and (65)Zn from the marine bacteria Pseudomonas stutzeri to the Mediterranean sponges Aplysina cavernicola and Ircinia oros. P. stutzeri efficiently bioaccumulated trace elements in our culture experimental conditions with CF comprised between 10(5) and 10(7) after 48 h of growth in radiolabeled medium. When fed with these radiolabelled bacteria, A. cavernicola took up around 60% of radiotracers accumulated in trophic source except (134)Cs for which only 8% has been transferred from bacteria to sponge. Contrasting to this, I. oros retained only 7% of (110m)Ag, (109)Cd and (65)Zn counted in bacteria, but retained 2-fold longer accumulated metals in its tissues. The sponge inter-specific differences of accumulation and depuration following a trophic exposure are discussed with respect to the structure and the clearance capacities of each species. PMID:26544727

  13. Aplysina red band syndrome: a new threat to Caribbean sponges.

    PubMed

    Olson, J B; Gochfeld, D J; Slattery, M

    2006-07-25

    A substantial and increasing number of reports have documented dramatic changes and continuing declines in Caribbean coral reef communities over the past 2 decades. To date, the majority of disease reports have focused on scleractinian corals, whereas sponge diseases have been less frequently documented. In this study, we describe Aplysina red band syndrome (ARBS) affecting Caribbean rope sponges of the genus Aplysina observed on shallow reefs in the Bahamas. Visible signs of disease presence included 1 or more rust-colored leading edges, with or without a trailing area of necrotic tissue, such that the lesion forms a contiguous band around part or all of the sponge branch. Microscopic examination of the leading edge of the disease margin indicated that a cyanobacterium was consistently responsible for the coloration. Although the presence of this distinctive coloration was used to characterize the diseased state, it is not yet known whether this cyanobacterium is directly responsible for disease causation. The prevalence of ARBS declined significantly from July to October 2004 before increasing above July levels in January 2005. Transmission studies in the laboratory demonstrated that contact with the leading edge of an active lesion was sufficient to spread ARBS to a previously healthy sponge, suggesting that the etiologic agent, currently undescribed, is contagious. Studies to elucidate the etiologic agent of ARBS are ongoing. Sponges are an essential component of coral reef communities and emerging sponge diseases clearly have the potential to impact benthic community structure on coral reefs. PMID:16956064

  14. Interpreting environmental signals from the coralline sponge Astrosclera willeyana

    SciTech Connect

    Fallon, S J; McCulloch, M T; Guilderson, T P

    2004-06-30

    Coralline sponges (sclerosponges) have been proposed as a new source for paleo subsurface temperature reconstructions by utilizing methods developed for reef-building corals. However unlike corals, coralline sponges do not have density variations making age determination difficult. In this study we examined multiple elemental rations (B, Mg, Sr, Ba, U) in the coralline sponge Astrosclera willeyana. We also measured skeletal density profiles along the outer ''living'' edge of the sponges and this data indicates significant thickening of skeletal material over intervals of 2-3 mm or 2-3 years. This suggests that any skeletal recovered environmental record from Astrosclera willeyana is an integration of signals over a 2-3 year period. Sponge Sr/Ca seemed to hold the most promise as a recorder of water temperature and we compared Sr/Ca from 2 sponges in the Great Barrier Reef and one from Truk in Micronesia to their respective sea surface temperature record. The correlations were not that strong ({approx} r=-0.5) but they were significant. It appears that the signal smoothing due to thickening or perhaps even some biologic control on Sr skeletal partitioning limits the use of Sr/Ca as an indicator of water temperature in Astrosclera willeyana.

  15. Metasurface Broadband Solar Absorber

    DOE PAGESBeta

    Azad, Abul K.; Kort-Kamp, Wilton J. M.; Sykora, Milan; Weisse-Bernstein, Nina R.; Luk, Ting S.; Taylor, Antoinette J.; Dalvit, Diego A. R.; Chen, Hou-Tong

    2016-02-01

    Here, we demonstrate a broadband, polarization independent, wide-angle absorber based on a metallic metasurface architecture, which accomplishes greater than 90% absorptance in the visible and near-infrared range of the solar spectrum, and exhibits low absorptivity (emissivity) at mid- and far-infrared wavelengths. The complex unit cell of the metasurface solar absorber consists of eight pairs of gold nano-resonators that are separated from a gold ground plane by a thin silicon dioxide spacer. Moreover, our experimental measurements reveal high-performance absorption over a wide range of incidence angles for both s- and p-polarizations. We also investigate numerically the frequency-dependent field and current distributionsmore » to elucidate how the absorption occurs within the metasurface structure.« less

  16. Metasurface Broadband Solar Absorber

    PubMed Central

    Azad, Abul K.; Kort-Kamp, Wilton J. M.; Sykora, Milan; Weisse-Bernstein, Nina R.; Luk, Ting S.; Taylor, Antoinette J.; Dalvit, Diego A. R.; Chen, Hou-Tong

    2016-01-01

    We demonstrate a broadband, polarization independent, wide-angle absorber based on a metallic metasurface architecture, which accomplishes greater than 90% absorptance in the visible and near-infrared range of the solar spectrum, and exhibits low absorptivity (emissivity) at mid- and far-infrared wavelengths. The complex unit cell of the metasurface solar absorber consists of eight pairs of gold nano-resonators that are separated from a gold ground plane by a thin silicon dioxide spacer. Our experimental measurements reveal high-performance absorption over a wide range of incidence angles for both s- and p-polarizations. We also investigate numerically the frequency-dependent field and current distributions to elucidate how the absorption occurs within the metasurface structure. PMID:26828999

  17. Metasurface Broadband Solar Absorber

    NASA Astrophysics Data System (ADS)

    Azad, Abul K.; Kort-Kamp, Wilton J. M.; Sykora, Milan; Weisse-Bernstein, Nina R.; Luk, Ting S.; Taylor, Antoinette J.; Dalvit, Diego A. R.; Chen, Hou-Tong

    2016-02-01

    We demonstrate a broadband, polarization independent, wide-angle absorber based on a metallic metasurface architecture, which accomplishes greater than 90% absorptance in the visible and near-infrared range of the solar spectrum, and exhibits low absorptivity (emissivity) at mid- and far-infrared wavelengths. The complex unit cell of the metasurface solar absorber consists of eight pairs of gold nano-resonators that are separated from a gold ground plane by a thin silicon dioxide spacer. Our experimental measurements reveal high-performance absorption over a wide range of incidence angles for both s- and p-polarizations. We also investigate numerically the frequency-dependent field and current distributions to elucidate how the absorption occurs within the metasurface structure.

  18. Metasurface Broadband Solar Absorber.

    PubMed

    Azad, Abul K; Kort-Kamp, Wilton J M; Sykora, Milan; Weisse-Bernstein, Nina R; Luk, Ting S; Taylor, Antoinette J; Dalvit, Diego A R; Chen, Hou-Tong

    2016-01-01

    We demonstrate a broadband, polarization independent, wide-angle absorber based on a metallic metasurface architecture, which accomplishes greater than 90% absorptance in the visible and near-infrared range of the solar spectrum, and exhibits low absorptivity (emissivity) at mid- and far-infrared wavelengths. The complex unit cell of the metasurface solar absorber consists of eight pairs of gold nano-resonators that are separated from a gold ground plane by a thin silicon dioxide spacer. Our experimental measurements reveal high-performance absorption over a wide range of incidence angles for both s- and p-polarizations. We also investigate numerically the frequency-dependent field and current distributions to elucidate how the absorption occurs within the metasurface structure. PMID:26828999

  19. Ionized Absorbers in AGN

    NASA Astrophysics Data System (ADS)

    Mathur, S.

    1999-08-01

    As a part of this program, we observed three AGN:PKS2251 + 113, PG0043 = 039 and PLH909. Two objects show signatures of absorbtion in their UV spectra. Based on our earlier modeling of X-ray warm absorbents, we expected to observe X-ray observation in these objects. The third, PLH909, is known to have soft excess in EINSTEIN data. Attachment: "Exploratory ASCA observation of broad absorption line quasi-stellar objects".

  20. Ionized Absorbers in AGN

    NASA Technical Reports Server (NTRS)

    Mathur, S.

    1999-01-01

    As a part of this program, we observed three AGN:PKS2251 + 113, PG0043 = 039 and PLH909. Two objects show signatures of absorbtion in their UV spectra. Based on our earlier modeling of X-ray warm absorbents, we expected to observe X-ray observation in these objects. The third, PLH909, is known to have soft excess in EINSTEIN data. Attachment: "Exploratory ASCA observation of broad absorption line quasi-stellar objects".

  1. Improving the cellular invasion into PHEMA sponges by incorporation of the RGD peptide ligand: the use of copolymerization as a means to functionalize PHEMA sponges.

    PubMed

    Paterson, Stefan M; Shadforth, Audra M A; Shaw, Jeremy A; Brown, David H; Chirila, Traian V; Baker, Murray V

    2013-12-01

    A monomer that contained the RGD ligand motif was synthesized and copolymerized with 2-hydroxyethyl methacrylate using polymerization-induced phase separation methods to form poly(2-hydroxyethyl methacrylate)-based hydrogel sponges. The sponges had morphologies of aggregated polymer droplets and interconnected pores, the pores having dimensions in the order of 10 μm typical of PHEMA sponges. RGD-containing moieties appeared to be evenly distributed through the polymer droplets. Compared to PHEMA sponges that were not functionalized with RGD, the new sponges containing RGD allowed greater invasion by human corneal epithelial cells, by advancing the attachment of cells to the surface of the polymer droplets. PMID:24094205

  2. Collagen VI related muscle disorders

    PubMed Central

    Lampe, A; Bushby, K

    2005-01-01

    Mutations in the genes encoding collagen VI (COL6A1, COL6A2, and COL6A3) cause Bethlem myopathy (BM) and Ullrich congenital muscular dystrophy (UCMD), two conditions which were previously believed to be completely separate entities. BM is a relatively mild dominantly inherited disorder characterised by proximal weakness and distal joint contractures. UCMD was originally described as an autosomal recessive condition causing severe muscle weakness with proximal joint contractures and distal hyperlaxity. Here we review the clinical phenotypes of BM and UCMD and their diagnosis and management, and provide an overview of the current knowledge of the pathogenesis of collagen VI related disorders. PMID:16141002

  3. Pezizomycotina dominates the fungal communities of South China Sea sponges Theonella swinhoei and Xestospongia testudinaria.

    PubMed

    Jin, Liling; Liu, Fang; Sun, Wei; Zhang, Fengli; Karuppiah, Valliappan; Li, Zhiyong

    2014-12-01

    Compared with the knowledge of sponge-associated bacterial diversity and ecological roles, the fungal diversity and ecological roles of sponges remain largely unknown. In this study, the fungal diversity and protein synthesis potential in two South China Sea sponges Theonella swinhoei and Xestospongia testudinaria were investigated by rRNA vs. rRNA gene analysis. EF4/fung5 was chosen after a series of PCR tests to target fungal 18S rRNA and 18S rRNA gene. Altogether, 283 high-quality sequences were obtained, which resulted in 26 Operational taxonomic units (OTUs) that were assigned to Ascomycota, Basidiomycota, and Blastocladiomycota. At subphylum level, 77.3% of sponge-derived sequences were affiliated with Pezizomycotina. The fungal compositions of T. swinhoei and X. testudinaria were different from that of ambient seawater. The predominant OTU shared between two sponges was rare in seawater, whereas the most abundant OTUs in seawater were not found in sponges. Additionally, the major OTUs of sponge cDNA datasets were shared in two sponges. The fungal diversity illustrated by sponge cDNA datasets correlated well with that derived from sponge DNA datasets, indicating that the major members of sponge-associated fungi had protein synthesis potential. This study highlighted the diversity of Pezizomycotina in marine sponge-fungi symbioses and the necessity of investigating ecological roles of sponge-associated fungi. PMID:25348120

  4. Aqueous Extract of Brazilian Green Propolis: Primary Components, Evaluation of Inflammation and Wound Healing by Using Subcutaneous Implanted Sponges

    PubMed Central

    de Moura, Sandra Aparecida Lima; Negri, Giuseppina; Salatino, Antônio; Lima, Luiza Dias da Cunha; Dourado, Luana Pereira Antunes; Mendes, Juliana Barros; Andrade, Silvia Passos; Ferreira, Mônica Alves Neves Diniz; Cara, Denise Carmona

    2011-01-01

    Propolis is a chemically complex resinous bee product which has gained worldwide popularity as a means to improve health condition and prevent diseases. The main constituents of an aqueous extract of a sample of green propolis from Southeast Brazil were shown by high performance liquid chromatography/mass spectroscopy/mass spectroscopy to be mono- and di-O-caffeoylquinic acids; phenylpropanoids known as important constituents of alcohol extracts of green propolis, such as artepillin C and drupanin were also detected in low amounts in the aqueous extract. The anti-inflammatory activity of this extract was evaluated by determination of wound healing parameters. Female Swiss mice were implanted subcutaneously with polyesther-polyurethane sponge discs to induce wound healing responses, and administered orally with green propolis (500 mg kg−1). At 4, 7 and 14 days post-implantation, the fibrovascular stroma and deposition of extracellular matrix were evaluated by histopathologic and morphometric analyses. In the propolis-treated group at Days 4 and 7 the inflammatory process in the sponge was reduced in comparison with control. A progressive increase in cell influx and collagen deposition was observed in control and propolis-treated groups during the whole period. However, these effects were attenuated in the propolis-treated group at Days 4 and 7, indicating that key factors of the wound healing process are modulated by propolis constituents. PMID:19690045

  5. Absorber for terahertz radiation management

    DOEpatents

    Biallas, George Herman; Apeldoorn, Cornelis; Williams, Gwyn P.; Benson, Stephen V.; Shinn, Michelle D.; Heckman, John D.

    2015-12-08

    A method and apparatus for minimizing the degradation of power in a free electron laser (FEL) generating terahertz (THz) radiation. The method includes inserting an absorber ring in the FEL beam path for absorbing any irregular THz radiation and thus minimizes the degradation of downstream optics and the resulting degradation of the FEL output power. The absorber ring includes an upstream side, a downstream side, and a plurality of wedges spaced radially around the absorber ring. The wedges form a scallop-like feature on the innermost edges of the absorber ring that acts as an apodizer, stopping diffractive focusing of the THz radiation that is not intercepted by the absorber. Spacing between the scallop-like features and the shape of the features approximates the Bartlett apodization function. The absorber ring provides a smooth intensity distribution, rather than one that is peaked on-center, thereby eliminating minor distortion downstream of the absorber.

  6. Corrosion resistant neutron absorbing coatings

    SciTech Connect

    Choi, Jor-Shan; Farmer, Joseph C.; Lee, Chuck K.; Walker, Jeffrey; Russell, Paige; Kirkwood, Jon; Yang, Nancy; Champagne, Victor

    2012-05-29

    A method of forming a corrosion resistant neutron absorbing coating comprising the steps of spray or deposition or sputtering or welding processing to form a composite material made of a spray or deposition or sputtering or welding material, and a neutron absorbing material. Also a corrosion resistant neutron absorbing coating comprising a composite material made of a spray or deposition or sputtering or welding material, and a neutron absorbing material.

  7. Corrosion resistant neutron absorbing coatings

    SciTech Connect

    Choi, Jor-Shan; Farmer, Joseph C; Lee, Chuck K; Walker, Jeffrey; Russell, Paige; Kirkwood, Jon; Yang, Nancy; Champagne, Victor

    2013-11-12

    A method of forming a corrosion resistant neutron absorbing coating comprising the steps of spray or deposition or sputtering or welding processing to form a composite material made of a spray or deposition or sputtering or welding material, and a neutron absorbing material. Also a corrosion resistant neutron absorbing coating comprising a composite material made of a spray or deposition or sputtering or welding material, and a neutron absorbing material.

  8. Sterol and genomic analyses validate the sponge biomarker hypothesis.

    PubMed

    Gold, David A; Grabenstatter, Jonathan; de Mendoza, Alex; Riesgo, Ana; Ruiz-Trillo, Iñaki; Summons, Roger E

    2016-03-01

    Molecular fossils (or biomarkers) are key to unraveling the deep history of eukaryotes, especially in the absence of traditional fossils. In this regard, the sterane 24-isopropylcholestane has been proposed as a molecular fossil for sponges, and could represent the oldest evidence for animal life. The sterane is found in rocks ∼650-540 million y old, and its sterol precursor (24-isopropylcholesterol, or 24-ipc) is synthesized today by certain sea sponges. However, 24-ipc is also produced in trace amounts by distantly related pelagophyte algae, whereas only a few close relatives of sponges have been assayed for sterols. In this study, we analyzed the sterol and gene repertoires of four taxa (Salpingoeca rosetta, Capsaspora owczarzaki, Sphaeroforma arctica, and Creolimax fragrantissima), which collectively represent the major living animal outgroups. We discovered that all four taxa lack C30 sterols, including 24-ipc. By building phylogenetic trees for key enzymes in 24-ipc biosynthesis, we identified a candidate gene (carbon-24/28 sterol methyltransferase, or SMT) responsible for 24-ipc production. Our results suggest that pelagophytes and sponges independently evolved C30 sterol biosynthesis through clade-specific SMT duplications. Using a molecular clock approach, we demonstrate that the relevant sponge SMT duplication event overlapped with the appearance of 24-isopropylcholestanes in the Neoproterozoic, but that the algal SMT duplication event occurred later in the Phanerozoic. Subsequently, pelagophyte algae and their relatives are an unlikely alternative to sponges as a source of Neoproterozoic 24-isopropylcholestanes, consistent with growing evidence that sponges evolved long before the Cambrian explosion ∼542 million y ago. PMID:26903629

  9. Sterol and genomic analyses validate the sponge biomarker hypothesis

    PubMed Central

    Gold, David A.; Grabenstatter, Jonathan; de Mendoza, Alex; Riesgo, Ana; Ruiz-Trillo, Iñaki

    2016-01-01

    Molecular fossils (or biomarkers) are key to unraveling the deep history of eukaryotes, especially in the absence of traditional fossils. In this regard, the sterane 24-isopropylcholestane has been proposed as a molecular fossil for sponges, and could represent the oldest evidence for animal life. The sterane is found in rocks ∼650–540 million y old, and its sterol precursor (24-isopropylcholesterol, or 24-ipc) is synthesized today by certain sea sponges. However, 24-ipc is also produced in trace amounts by distantly related pelagophyte algae, whereas only a few close relatives of sponges have been assayed for sterols. In this study, we analyzed the sterol and gene repertoires of four taxa (Salpingoeca rosetta, Capsaspora owczarzaki, Sphaeroforma arctica, and Creolimax fragrantissima), which collectively represent the major living animal outgroups. We discovered that all four taxa lack C30 sterols, including 24-ipc. By building phylogenetic trees for key enzymes in 24-ipc biosynthesis, we identified a candidate gene (carbon-24/28 sterol methyltransferase, or SMT) responsible for 24-ipc production. Our results suggest that pelagophytes and sponges independently evolved C30 sterol biosynthesis through clade-specific SMT duplications. Using a molecular clock approach, we demonstrate that the relevant sponge SMT duplication event overlapped with the appearance of 24-isopropylcholestanes in the Neoproterozoic, but that the algal SMT duplication event occurred later in the Phanerozoic. Subsequently, pelagophyte algae and their relatives are an unlikely alternative to sponges as a source of Neoproterozoic 24-isopropylcholestanes, consistent with growing evidence that sponges evolved long before the Cambrian explosion ∼542 million y ago. PMID:26903629

  10. Biology, chemistry and pathology of collagen

    SciTech Connect

    Fleischmajer, R.; Olsen, B.R.; Kuhn, K.

    1985-01-01

    This book consists of five parts and a section of poster papers. Some of the articles are: Structure of the Type II Collagen Gene; Structural and Functional Analysis of the Genes for ..cap alpha..2(1) and ..cap alpha..1(III) collagens; Structure and Expression of the Collagen Genes of C. Elegans; Molecular Basis of Clinical Heterogeneity in the Ehlers-Danlos Syndrome; and Normal and Mutant Human Collagen Genes.

  11. In vitro mineralization of dense collagen substrates: a biomimetic approach toward the development of bone-graft materials.

    PubMed

    Thula, Taili T; Rodriguez, Douglas E; Lee, Myong Hwa; Pendi, Laura; Podschun, Jacob; Gower, Laurie B

    2011-08-01

    Bone is an organic-inorganic composite which has hierarchical structuring that leads to high strength and toughness. The nanostructure of bone consists of nanocrystals of hydroxyapatite embedded and aligned within the interstices of collagen fibrils. This unique nanostructure leads to exceptional properties, both mechanical and biological, making it difficult to emulate bone properties without having a bone-like nanostructured material. A primary goal of our group's work is to use biomimetic processing techniques that lead to bone-like structures. In our prior studies, we demonstrated that intrafibrillar mineralization of porous collagen sponges, leading to a bone-like nanostructure, can be achieved using a polymer-induced liquid precursor (PILP) mineralization process. The objective of this study was to investigate the use of this polymer-directed crystallization process to mineralize dense collagen substrates. To examine collagen scaffolds that truly represent the dense-packed matrix of bone, manatee bone was demineralized to isolate its collagen matrix, consisting of a dense, lamellar osteonal microstructure. This biogenic collagen scaffold was then remineralized using polyaspartate to direct the mineralization process through an amorphous precursor pathway. The various conditions investigated included polymer molecular weight, substrate dimension and mineralization time. Mineral penetration depths of up to 100 μms were achieved using this PILP process, compared to no penetration with only surface precipitates observed for the conventional crystallization process. Electron microscopy, wide-angle X-ray diffraction and thermal analysis were used to characterize the resulting hydroxyapatite/collagen composites. These studies demonstrate that the original interpenetrating bone nanostructure and osteonal microstructure could be recovered in a biogenic matrix using the PILP process. PMID:21550424

  12. Solar radiation absorbing material

    DOEpatents

    Googin, John M.; Schmitt, Charles R.; Schreyer, James M.; Whitehead, Harlan D.

    1977-01-01

    Solar energy absorbing means in solar collectors are provided by a solar selective carbon surface. A solar selective carbon surface is a microporous carbon surface having pores within the range of 0.2 to 2 micrometers. Such a surface is provided in a microporous carbon article by controlling the pore size. A thermally conductive substrate is provided with a solar selective surface by adhering an array of carbon particles in a suitable binder to the substrate, a majority of said particles having diameters within the range of about 0.2-10 microns.

  13. Absorber for solar power.

    PubMed

    Powell, W R

    1974-10-01

    A simple, economical absorber utilizing a new principle of operation to achieve very low reradiation losses while generating temperatures limited by material properties of quartz is described. Its performance is analyzed and indicates approximately 90% thermal efficiency and 73% conversion efficiency for an earth based unit with moderately concentrated (~tenfold) sunlight incident. It is consequently compatible with the most economic of concentrator mirrors (stamped) or mirrors deployable in space. Space applications are particularly attractive, as temperatures significantly below 300 K are possible and permit even higher conversion efficiency. PMID:20134700

  14. 21 CFR 529.1003 - Flurogestone acetate-impregnated vaginal sponge.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... into ewe's vagina 13 days before desired start of breeding. For intravaginal use in sheep only. Do not... sponges to minimize exposure to drug. Do not leave sponge in the vagina for more than 21 days. Ewes...

  15. A Superamphiphobic Sponge with Mechanical Durability and a Self-Cleaning Effect

    NASA Astrophysics Data System (ADS)

    Kim, Daewon; Im, Hwon; Kwak, Moo Jin; Byun, Eunkyoung; Im, Sung Gap; Choi, Yang-Kyu

    2016-07-01

    A robust superamphiphobic sponge (SA-sponge) is proposed by using a single initiated chemical vapor deposition (i-CVD) process. Poly(3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyl methacrylate) (PFDMA) is deposited on a commercial sponge by the polymerization of fluoroalkyl acrylates during the i-CVD process. This PFDMA is conformally coated onto both the exterior and interior of the sponge structure by a single step of the i-CVD process at nearly room temperature. Due to the inherent porous structure of the sponge and the hydrophobic property of the fluorine-based PFDMA, the demonstrated SA-sponge shows not only superhydrophobicity but also superoleophobicity. Furthermore, the fabricated SA-sponge is robust with regard to physical and chemical damage. The fabricated SA-sponge can be utilized for multi-purpose applications such as gas-permeable liquid separators.

  16. A Superamphiphobic Sponge with Mechanical Durability and a Self-Cleaning Effect.

    PubMed

    Kim, Daewon; Im, Hwon; Kwak, Moo Jin; Byun, Eunkyoung; Im, Sung Gap; Choi, Yang-Kyu

    2016-01-01

    A robust superamphiphobic sponge (SA-sponge) is proposed by using a single initiated chemical vapor deposition (i-CVD) process. Poly(3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyl methacrylate) (PFDMA) is deposited on a commercial sponge by the polymerization of fluoroalkyl acrylates during the i-CVD process. This PFDMA is conformally coated onto both the exterior and interior of the sponge structure by a single step of the i-CVD process at nearly room temperature. Due to the inherent porous structure of the sponge and the hydrophobic property of the fluorine-based PFDMA, the demonstrated SA-sponge shows not only superhydrophobicity but also superoleophobicity. Furthermore, the fabricated SA-sponge is robust with regard to physical and chemical damage. The fabricated SA-sponge can be utilized for multi-purpose applications such as gas-permeable liquid separators. PMID:27435167

  17. A Superamphiphobic Sponge with Mechanical Durability and a Self-Cleaning Effect

    PubMed Central

    Kim, Daewon; Im, Hwon; Kwak, Moo Jin; Byun, Eunkyoung; Im, Sung Gap; Choi, Yang-Kyu

    2016-01-01

    A robust superamphiphobic sponge (SA-sponge) is proposed by using a single initiated chemical vapor deposition (i-CVD) process. Poly(3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyl methacrylate) (PFDMA) is deposited on a commercial sponge by the polymerization of fluoroalkyl acrylates during the i-CVD process. This PFDMA is conformally coated onto both the exterior and interior of the sponge structure by a single step of the i-CVD process at nearly room temperature. Due to the inherent porous structure of the sponge and the hydrophobic property of the fluorine-based PFDMA, the demonstrated SA-sponge shows not only superhydrophobicity but also superoleophobicity. Furthermore, the fabricated SA-sponge is robust with regard to physical and chemical damage. The fabricated SA-sponge can be utilized for multi-purpose applications such as gas-permeable liquid separators. PMID:27435167

  18. Neovascularization in aged mice: delayed angiogenesis is coincident with decreased levels of transforming growth factor beta1 and type I collagen.

    PubMed Central

    Reed, M. J.; Corsa, A.; Pendergrass, W.; Penn, P.; Sage, E. H.; Abrass, I. B.

    1998-01-01

    Angiogenesis, the growth of new vessels from existing microvasculature, is delayed in aged animals. In this study we asked whether this impairment might be due, in part, to changes in the expression of a growth factor, transforming growth factor-beta1 (TGF-beta1), and a matrix protein, type I collagen, which have been shown to regulate angiogenesis in vivo. We implanted polyvinyl alcohol sponges subcutaneously in the dorsa of young and aged mice and examined the sponges 7 to 21 days later for the presence of invasive fibrovascular bundles. Blood vessel ingrowth and proliferative activity were assessed by immunostain for von Willebrand factor and Ki-67, respectively. The fibrovascular bundles were also analyzed for TGF-beta1 and type I collagen. Relative to young mice, angiogenic invasion of sponges in aged mice was similar at 7 days, was diminished significantly (70%) at 14 days, but was again similar by 21 days after implantation. The expression of TGF-beta1 and type I collagen mRNA and protein in fibrovascular bundles was coincident but was also delayed (42 to 47%) at 14 days in the aged mice. Moreover, levels of active TGF-beta1 were decreased (48%) in the sera of aged relative to young mice. The delay in angiogenesis in aged mice was thus associated with decreased expression of TGF-beta1 and type I collagen by neovascular bundles. We conclude that changes in the levels of growth factors and proteins in the extracellular matrix contribute to impaired angiogenesis in aging. Images Figure 1 Figure 2 Figure 4 Figure 5 Figure 7 Figure 8 PMID:9422529

  19. Three-dimensional direct cell patterning in collagen hydrogels with near-infrared femtosecond laser

    PubMed Central

    Hribar, Kolin C.; Meggs, Kyle; Liu, Justin; Zhu, Wei; Qu, Xin; Chen, Shaochen

    2015-01-01

    We report a methodology for three-dimensional (3D) cell patterning in a hydrogel in situ. Gold nanorods within a cell-encapsulating collagen hydrogel absorb a focused near-infrared femtosecond laser beam, locally denaturing the collagen and forming channels, into which cells migrate, proliferate, and align in 3D. Importantly, pattern resolution is tunable based on writing speed and laser power, and high cell viability (>90%) is achieved using higher writing speeds and lower laser intensities. Overall, this patterning technique presents a flexible direct-write method that is applicable in tissue engineering systems where 3D alignment is critical (such as vascular, neural, cardiac, and muscle tissue). PMID:26603915

  20. Three-dimensional direct cell patterning in collagen hydrogels with near-infrared femtosecond laser

    NASA Astrophysics Data System (ADS)

    Hribar, Kolin C.; Meggs, Kyle; Liu, Justin; Zhu, Wei; Qu, Xin; Chen, Shaochen

    2015-11-01

    We report a methodology for three-dimensional (3D) cell patterning in a hydrogel in situ. Gold nanorods within a cell-encapsulating collagen hydrogel absorb a focused near-infrared femtosecond laser beam, locally denaturing the collagen and forming channels, into which cells migrate, proliferate, and align in 3D. Importantly, pattern resolution is tunable based on writing speed and laser power, and high cell viability (>90%) is achieved using higher writing speeds and lower laser intensities. Overall, this patterning technique presents a flexible direct-write method that is applicable in tissue engineering systems where 3D alignment is critical (such as vascular, neural, cardiac, and muscle tissue).

  1. Exposure to Mimivirus Collagen Promotes Arthritis

    PubMed Central

    Shah, Nikunj; Hülsmeier, Andreas J.; Hochhold, Nina; Neidhart, Michel; Gay, Steffen

    2014-01-01

    Collagens, the most abundant proteins in animals, also occur in some recently described nucleocytoplasmic large DNA viruses such as Mimiviridae, which replicate in amoebae. To clarify the impact of viral collagens on the immune response of animals exposed to Mimiviridae, we have investigated the localization of collagens in Acanthamoeba polyphaga mimivirus particles and the response of mice to immunization with mimivirus particles. Using protein biotinylation, we have first shown that viral collagen encoded by open reading frame L71 is present at the surface of mimivirus particles. Exposure to mimivirus collagens elicited the production of anti-collagen antibodies in DBA/1 mice immunized intradermally with mimivirus protein extracts. This antibody response also targeted mouse collagen type II and was accompanied by T-cell reactivity to collagen and joint inflammation, as observed in collagen-induced arthritis following immunization of mice with bovine collagen type II. The broad distribution of nucleocytoplasmic large DNA viruses in the environment suggests that humans are constantly exposed to such large virus particles. A survey of blood sera from healthy human subjects and from rheumatoid arthritis patients indeed demonstrated that 30% of healthy-subject and 36% of rheumatoid arthritis sera recognized the major mimivirus capsid protein L425. Moreover, whereas 6% of healthy-subject sera recognized the mimivirus collagen protein L71, 22% of rheumatoid arthritis sera were positive for mimivirus L71. Accordingly, our study shows that environmental exposure to mimivirus represents a risk factor in triggering autoimmunity to collagens. PMID:24173233

  2. Biomimetic Analogs for Collagen Biomineralization

    PubMed Central

    Gu, L.; Kim, Y.K.; Liu, Y.; Ryou, H.; Wimmer, C.E.; Dai, L.; Arola, D.D.; Looney, S.W.; Pashley, D.H.; Tay, F.R.

    2011-01-01

    Inability of chemical phosphorylation of sodium trimetaphosphate to induce intrafibrillar mineralization of type I collagen may be due to the failure to incorporate a biomimetic analog to stabilize amorphous calcium phosphates (ACP) as nanoprecursors. This study investigated adsorption/desorption characteristics of hydrolyzed and pH-adjusted sodium trimetaphosphate (HPA-Na3P3O9) to collagen. Based on those results, a 5-minute treatment time with 2.8 wt% HPA-Na3P3O9 was used in a single-layer reconstituted collagen model to confirm that both the ACP-stabilization analog and matrix phosphoprotein analog must be present for intrafibrillar mineralization. The results of that model were further validated by complete remineralization of phosphoric-acid-etched dentin treated with the matrix phosphoprotein analog and lined with a remineralizing lining composite, and with the ACP-stabilization analog supplied in simulated body fluid. An understanding of the basic processes involved in intrafibrillar mineralization of reconstituted collagen fibrils facilitates the design of novel tissue engineering materials for hard tissue repair and regeneration. PMID:20940362

  3. Rapid biomimetic mineralization of collagen fibrils and combining with human umbilical cord mesenchymal stem cells for bone defects healing.

    PubMed

    Ye, Bihua; Luo, Xueshi; Li, Zhiwen; Zhuang, Caiping; Li, Lihua; Lu, Lu; Ding, Shan; Tian, Jinhuan; Zhou, Changren

    2016-11-01

    Collagen biomineralization is regulated by complicated interactions between the collagen matrix and non-collagenous extracellular proteins. Here, the use of sodium tripolyphosphate to simulate the templating functional motif of the C-terminal fragment of non-collagenous proteins is reported, and a low molecular weight polyacrylic acid served as a sequestration agent to stabilize amorphous calcium phosphate into nanoprecursors. Self-assembled collagen fibrils served as a fixed template for achieving rapid biomimetic mineralization in vitro. Results demonstrated that, during the mineralization process, intrafibrillar and extrafibrillar hydroxyapatite mineral with collagen fibrils formed and did so via bottom-up nanoparticle assembly based on the non-classical crystallization approach in the presence of these dual biomimetic functional analogues. In vitro human umbilical cord mesenchymal stem cell (hUCMSC) culture found that the mineralized scaffolds have a better cytocompatibility in terms of cell viability, adhesion, proliferation, and differentiation into osteoblasts. A rabbit femoral condyle defect model was established to confirm the ability of the n-HA/collagen scaffolds to facilitate bone regeneration and repair. The images of gross anatomy, MRI, CT and histomorphology taken 6 and 12weeks after surgery showed that the biomimetic mineralized collagen scaffolds with hUCMSCs can promote the healing speed of bone defects in vivo, and both of the scaffolds groups performing better than the bone defect control group. As new bone tissue formed, the scaffolds degraded and were gradually absorbed. All these results demonstrated that both of the scaffolds and cells have better histocompatibility. PMID:27523994

  4. Contact sponge water absorption test implemented for in situ measures

    NASA Astrophysics Data System (ADS)

    Gaggero, Laura; Scrivano, Simona

    2016-04-01

    The contact sponge method is a non-destructive in-situ methodology used to estimate a water uptake coefficient. The procedure, unlike other in-situ measurement was proven to be directly comparable to the water uptake laboratory measurements, and was registered as UNI 11432:2011. The UNI Normal procedure requires to use a sponge with known density, soaked in water, weighed, placed on the material for 1 minute (UNI 11432, 2011; Pardini & Tiano, 2004), then weighed again. Difficulties arise in operating on test samples or on materials with porosity varied for decay. While carrying on the test, fluctuations in the bearing of the environmental parameters were negligible, but not the pressure applied to the surface, that induced the release of different water amounts towards the material. For this reason we designed a metal piece of the same diameter of the plate carrying the sponge, to be screwed at the tip of a pocket penetrometer. With this instrument the sponge was kept in contact with the surface for 1 minute applying two different loads, at first pushed with 0.3 kg/cm2 in order to press the sponge, but not its holder, against the surface. Then, a load of 1.1 kg/ cm2 was applied, still avoiding deviating the load to the sponge holder. We applied both the current and our implemented method to determine the water absorption by contact sponge on 5 fresh rock types (4 limestones: Fine - and Coarse grained Pietra di Vicenza, Rosso Verona, Breccia Aurora, and the silicoclastic Macigno sandstone). The results show that 1) the current methodology imply manual skill and experience to produce a coherent set of data; the variable involved are in fact not only the imposed pressure but also the compression mechanics. 2) The control on the applied pressure allowed reproducible measurements. Moreover, 3) the use of a thicker sponge enabled to apply the method even on rougher surfaces, as the device holding the sponge is not in contact with the tested object. Finally, 4) the

  5. Green strength of zirconium sponge and uranium dioxide powder compacts

    SciTech Connect

    Balakrishna, Palanki Murty, B. Narasimha; Sahoo, P.K.; Gopalakrishna, T.

    2008-07-15

    Zirconium metal sponge is compacted into rectangular or cylindrical shapes using hydraulic presses. These shapes are stacked and electron beam welded to form a long electrode suitable for vacuum arc melting and casting into solid ingots. The compact electrodes should be sufficiently strong to prevent breakage in handling as well as during vacuum arc melting. Usually, the welds are strong and the electrode strength is limited by the green strength of the compacts, which constitute the electrode. Green strength is also required in uranium dioxide (UO{sub 2}) powder compacts, to withstand stresses during de-tensioning after compaction as well as during ejection from the die and for subsequent handling by man and machine. The strengths of zirconium sponge and UO{sub 2} powder compacts have been determined by bending and crushing respectively, and Weibul moduli evaluated. The green density of coarse sponge compact was found to be larger than that from finer sponge. The green density of compacts from lightly attrited UO{sub 2} powder was higher than that from unattrited category, accompanied by an improvement in UO{sub 2} green crushing strength. The factors governing green strength have been examined in the light of published literature and experimental evidence. The methodology and results provide a basis for quality control in metal sponge and ceramic powder compaction in the manufacture of nuclear fuel.

  6. First insights into the microbiome of a carnivorous sponge.

    PubMed

    Dupont, Samuel; Corre, Erwan; Li, Yanyan; Vacelet, Jean; Bourguet-Kondracki, Marie-Lise

    2013-12-01

    Using 454 pyrosequencing, we characterized for the first time the associated microbial community of the deep-sea carnivorous Demosponge Asbestopluma hypogea (Cladorhizidae). Targeting the 16S rRNA gene V3 and V6 hypervariable regions, we compared the diversity and composition of associated microbes of two individual sponges of A. hypogea freshly collected in the cave with surrounding seawater and with one sponge sample maintained 1 year in an aquarium after collection. With more than 22 961 high quality sequences from sponge samples, representing c. 800 operational taxonomic units per sponge sample at 97% sequence similarities, the phylogenetic affiliation of A. hypogea-associated microbes was assigned to 20 bacterial and two archaeal phyla, distributed into 45 classes and 95 orders. Several differences between the sponge and seawater microbes were observed, highlighting a specific and stable A. hypogea microbial community dominated by Proteobacteria and Bacteroidetes and Thaumarchaeota phyla. A high relative abundance of ammonia-oxidizing archaea and a dominance of sulfate oxidizing/reducing bacteria were observed. Our findings shed lights on the potential roles of associated microbial community in the lifestyle of A. hypogea. PMID:23845054

  7. Advancement into the Arctic Region for Bioactive Sponge Secondary Metabolites

    PubMed Central

    Abbas, Samuel; Kelly, Michelle; Bowling, John; Sims, James; Waters, Amanda; Hamann, Mark

    2011-01-01

    Porifera have long been a reservoir for the discovery of bioactive compounds and drug discovery. Most research in the area has focused on sponges from tropical and temperate waters, but more recently the focus has shifted to the less accessible colder waters of the Antarctic and, to a lesser extent, the Arctic. The Antarctic region in particular has been a more popular location for natural products discovery and has provided promising candidates for drug development. This article reviews groups of bioactive compounds that have been isolated and reported from the southern reaches of the Arctic Circle, surveys the known sponge diversity present in the Arctic waters, and details a recent sponge collection by our group in the Aleutian Islands, Alaska. The collection has yielded previously undescribed sponge species along with primary activity against opportunistic infectious diseases, malaria, and HCV. The discovery of new sponge species and bioactive crude extracts gives optimism for the isolation of new bioactive compounds from a relatively unexplored source. PMID:22163194

  8. Immunotoxicity of washing soda in a freshwater sponge of India.

    PubMed

    Mukherjee, Soumalya; Ray, Mitali; Ray, Sajal

    2015-03-01

    The natural habitat of sponge, Eunapius carteri faces an ecotoxicological threat of contamination by washing soda, a common household cleaning agent of India. Washing soda is chemically known as sodium carbonate and is reported to be toxic to aquatic organisms. Domestic effluent, drain water and various human activities in ponds and lakes have been identified as the major routes of washing soda contamination of water. Phagocytosis and generation of cytotoxic molecules are important immunological responses offered by the cells of sponges against environmental toxins and pathogens. Present study involves estimation of phagocytic response and generation of cytotoxic molecules like superoxide anion, nitric oxide and phenoloxidase in E. carteri under the environmentally realistic concentrations of washing soda. Sodium carbonate exposure resulted in a significant decrease in the phagocytic response of sponge cells under 4, 8, 16 mg/l of the toxin for 96h and all experimental concentrations of the toxin for 192h. Washing soda exposure yielded an initial increase in the generation of the superoxide anion and nitric oxide followed by a significant decrease in generation of these cytotoxic agents. Sponge cell generated a high degree of phenoloxidase activity under the experimental exposure of 2, 4, 8, 16 mg/l of sodium carbonate for 96 and 192 h. Washing soda induced alteration of phagocytic and cytotoxic responses of E. carteri was indicative to an undesirable shift in their immune status leading to the possible crises of survival and propagation of sponges in their natural habitat. PMID:25497767

  9. Screening for Methicillin-Resistant Staphylococcus aureus Colonization Using Sponges

    PubMed Central

    Lee, Chang-Seop; Montalmont, Bianca; O’Hara, Jessica A.; Syed, Alveena; Chaussard, Charma; McGaha, Traci L.; Pakstis, Diana L.; Lee, Ju-Hyung; Shutt, Kathleen A.; Doi, Yohei

    2015-01-01

    OBJECTIVE Nasal swab culture is the standard method for identifying methicillin-resistant Staphylococcus aureus (MRSA) carriers. However, this method is known to miss a substantial portion of those carrying MRSA elsewhere. We hypothesized that the additional use of a sponge to collect skin culture samples would significantly improve the sensitivity of MRSA detection. DESIGN Hospitalized patients with recent MRSA infection were enrolled and underwent MRSA screening of the forehead, nostrils, pharynx, axilla, and groin with separate swabs and the forehead, axilla, and groin with separate sponges. Staphylococcal cassette chromosome mec (SCCmec) typing was conducted by polymerase chain reaction (PCR). PATIENTS A total of 105 MRSA patients were included in the study. RESULTS At least 1 specimen from 56.2% of the patients grew MRSA. Among patients with at least 1 positive specimen, the detection sensitivities were 79.7% for the swabs and 64.4% for the sponges. Notably, 86.4% were detected by a combination of sponges and nasal swab, and 72.9% were detected by a combination of pharyngeal and nasal swabs, whereas only 50.9% were detected by nasal swab alone (P < 0.0001 and P = 0.0003, respectively). Most isolates had SCCmec type II (59.9%) and IV (35.7%). No correlation was observed between the SCCmec types and collection sites. CONCLUSION Screening using a sponge significantly improves MRSA detection when used in addition to screening with the standard nasal swab. PMID:25627758

  10. Silicon isotopes in sponge spicules: the story of a proxy

    NASA Astrophysics Data System (ADS)

    Hendry, K. R.; Maldonado, M.; Goodwin, C.; Berman, J.; De La Rocha, C. L.

    2014-12-01

    The silicon isotope composition of deep-sea sponges has been shown to reflect the concentration of dissolved silicon, silicic acid, in seawater. This discovery has lead to the development of a novel geochemical proxy for past deep water nutrient status, which has already been applied to a wide range of palaeoceanographic questions ranging from Southern Ocean silicic acid leakage on glacial-interglacial and millennial timescales, to the proliferation of diatoms at the Eocene-Oligocene boundary. The initial calibrations based on modern sponge samples showed some scatter in the relationship between sponge silicon isotopes and silicic acid concentration, but without any apparent systematic influence from other environmental factors (temperature, pH, or other nutrients), morphology or species. However, a silicon isotope calibration of core top spicules, based on measurements made on a large number of spicules extracted from sediments, shows a tighter relationship with silicic acid concentrations, indicating that there are variations between and within individuals that are "averaged out" during palaeoceanographic studies. As is the case for all novel geochemical proxies, there is a need to test the proxy rigorously to ensure robust interpretation of any downcore signal. Here, we will present new studies of modern sponge specimens that have been carried out to shed light on the processes that could result in differences in silicon isotopic fractionation between and within individual sponges. Our findings highlight where caution is required in order to produce robust downcore records of past ocean silicic acid concentrations.

  11. Morphological features of bone healing under the effect of collagen-graft-glycosaminoglycan copolymer supplemented with the tripeptide Gly-His-Lys.

    PubMed

    Pohunková, H; Stehlík, J; Váchal, J; Cech, O; Adam, M

    1996-08-01

    The authors prepared 7.5% and 12.5% collagen gel, and supplemented it with the tripeptide Gly-His-Lys (GHK), perfloxacine and hypersulphated glycosaminoglycan (HSGAG). By means of 125l marking, its absorption was followed from small polyurethane sponges placed under the skin of rats. The absorption of gel without HSGAG was found to be faster. Antibodies against collagen (type I, II and III) or collagen gel were generated either in rabbits or in minipigs, in which collagen gel was tested. Microbiological tests proved the sterility of the collagen gel. The collagen gel supplemented with GHK, pefloxacine and HSGAG was named Colladel, and was used in a model experiment in guinea-pigs for filling artificially created bone defects in diaphyses of femurs, and with cementless endoprostheses. The healing process was followed by means of RTG and NMR, and histologically. The slowest healing process was found in unfilled bone defects. Defects filled with Colladel without GHK healed substantially more quickly, and the most accelerated healing was connected with complete Colladel application. When Colladel was used with cementless endoprostheses, vivid osteogenic activity at the interface of trabecular bone and metal stem was detectable in the course of the experiment. PMID:8842360

  12. The unique skeleton of siliceous sponges (Porifera; Hexactinellida and Demospongiae) that evolved first from the Urmetazoa during the Proterozoic: a review

    NASA Astrophysics Data System (ADS)

    Müller, W. E. G.; Li, Jinhe; Schröder, H. C.; Qiao, Li; Wang, Xiaohong

    2007-05-01

    Sponges (phylum Porifera) had been considered as an enigmatic phylum, prior to the analysis of their genetic repertoire/tool kit. Already with the isolation of the first adhesion molecule, galectin, it became clear that the sequences of sponge cell surface receptors and of molecules forming the intracellular signal transduction pathways triggered by them, share high similarity with those identified in other metazoan phyla. These studies demonstrated that all metazoan phyla, including Porifera, originate from one common ancestor, the Urmetazoa. The sponges evolved prior to the Ediacaran-Cambrian boundary (542 million years ago [myr]) during two major "snowball earth events", the Sturtian glaciation (710 to 680 myr) and the Varanger-Marinoan ice ages (605 to 585 myr). During this period the ocean was richer in silica due to the silicate weathering. The oldest sponge fossils (Hexactinellida) have been described from Australia, China and Mongolia and are thought to have existed coeval with the diverse Ediacara fauna. Only little younger are the fossils discovered in the Sansha section in Hunan (Early Cambrian; China). It has been proposed that only the sponges possessed the genetic repertoire to cope with the adverse conditions, e.g. temperature-protection molecules or proteins protecting them against ultraviolet radiation. The skeletal elements of the Hexactinellida (model organisms Monorhaphis chuni and Monorhaphis intermedia or Hyalonema sieboldi) and Demospongiae (models Suberites domuncula and Geodia cydonium), the spicules, are formed enzymatically by the anabolic enzyme silicatein and the catabolic enzyme silicase. Both, the spicules of Hexactinellida and of Demospongiae, comprise a central axial canal and an axial filament which harbors the silicatein. After intracellular formation of the first lamella around the channel and the subsequent extracellular apposition of further lamellae the spicules are completed in a net formed of collagen fibers. The data

  13. The unique skeleton of siliceous sponges (Porifera; Hexactinellida and Demospongiae) that evolved first from the Urmetazoa during the Proterozoic: a review

    NASA Astrophysics Data System (ADS)

    Müller, W. E. G.; Li, J.; Schröder, H. C.; Qiao, L.; Wang, X.

    2007-02-01

    net formed of collagen fibers. The data summarized here substantiate that with the finding of silicatein a new aera in the field of bio/inorganic chemistry started. For the first time strategies could be formulated and experimentally proven that allow the formation/synthesis of inorganic structures by organic molecules. These findings are not only of importance for the further understanding of basic pathways in the body plan formation of sponges but also of eminent importance for applied/commercial processes in a sustainable use of biomolecules for novel bio/inorganic materials.

  14. Liquid Cryogen Absorber for MICE

    SciTech Connect

    Baynham, D.E.; Bish, P.; Bradshaw, T.W.; Cummings, M.A.; Green,M.A.; Ishimoto, S.; Ivaniouchenkov, I.; Lau, W.; Yang, S.Q.; Zisman, M.S.

    2005-08-20

    The Muon Ionization Cooling Experiment (MICE) will test ionization cooling of muons. In order to have effective ionization cooling, one must use an absorber that is made from a low-z material. The most effective low z materials for ionization cooling are hydrogen, helium, lithium hydride, lithium and beryllium, in that order. In order to measure the effect of material on cooling, several absorber materials must be used. This report describes a liquid-hydrogen absorber that is within a pair of superconducting focusing solenoids. The absorber must also be suitable for use with liquid helium. The following absorber components are discussed in this report; the absorber body, its heat exchanger, the hydrogen system, and the hydrogen safety. Absorber cooling and the thin windows are not discussed here.

  15. 21 CFR 529.1003 - Flurogestone acetate-impregnated vaginal sponge.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Flurogestone acetate-impregnated vaginal sponge... § 529.1003 Flurogestone acetate-impregnated vaginal sponge. (a) Specifications. Each vaginal sponge... ewes during their normal breeding season. (2) Limitations. Using applicator provided, insert...

  16. 21 CFR 529.1003 - Flurogestone acetate-impregnated vaginal sponge.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Flurogestone acetate-impregnated vaginal sponge... § 529.1003 Flurogestone acetate-impregnated vaginal sponge. (a) Specifications. Each vaginal sponge... ewes during their normal breeding season. (2) Limitations. Using applicator provided, insert...

  17. A Novel Filtering Mutualism between a Sponge Host and Its Endosymbiotic Bivalves

    PubMed Central

    Tsubaki, Remi; Kato, Makoto

    2014-01-01

    Sponges, porous filter-feeding organisms consisting of vast canal systems, provide unique substrates for diverse symbiotic organisms. The Spongia (Spongia) sp. massive sponge is obligately inhabited by the host-specific endosymbiotic bivalve Vulsella vulsella, which benefits from this symbiosis by receiving protection from predators. However, whether the host sponge gains any benefit from this association is unclear. Considering that the bivalves exhale filtered water into the sponge body rather than the ambient environment, the sponge is hypothesized to utilize water exhaled by the bivalves to circulate water around its body more efficiently. We tested this hypothesis by observing the sponge aquiferous structure and comparing the pumping rates of sponges and bivalves. Observations of water currents and the sponge aquiferous structure revealed that the sponge had a unique canal system enabling it to inhale water exhaled from bivalves, indicating that the host sponge adapted morphologically to receive water from the bivalves. In addition, the volume of water circulating in the sponge body was dramatically increased by the water exhaled from bivalves. Therefore, this sponge-bivalve association can be regarded as a novel mutualism in which two filter-feeding symbionts promote mutual filtering rates. This symbiotic association should be called a “filtering mutualism”. PMID:25330073

  18. Diversity of the candidate phylum Poribacteria in the marine sponge Aplysina fulva.

    PubMed

    Hardoim, C C P; Cox, C J; Peixoto, R S; Rosado, A S; Costa, R; van Elsas, J D

    2013-01-01

    Poribacterial clone libraries constructed for Aplysina fulva sponge specimens were analysed with respect to diversity and phylogeny. Results imply the coexistence of several, prevalently "intra-specific" poribacterial genotypes in a single sponge host, and suggest quantitative analysis as a desirable approach in studies of the diversity and distribution of poribacterial cohorts in marine sponges. PMID:24159324

  19. Evidence of a Putative Deep Sea Specific Microbiome in Marine Sponges

    PubMed Central

    Kennedy, Jonathan; Flemer, Burkhardt; Jackson, Stephen A.; Morrissey, John P.; O'Gara, Ferghal; Dobson, Alan D. W.

    2014-01-01

    The microbiota of four individual deep water sponges, Lissodendoryx diversichela, Poecillastra compressa, Inflatella pellicula, and Stelletta normani, together with surrounding seawater were analysed by pyrosequencing of a region of the 16S rRNA gene common to Bacteria and Archaea. Due to sampling constraints at depths below 700 m duplicate samples were not collected. The microbial communities of L. diversichela, P. compressa and I. pellicula were typical of low microbial abundance (LMA) sponges while S. normani had a community more typical of high microbial abundance (HMA) sponges. Analysis of the deep sea sponge microbiota revealed that the three LMA-like sponges shared a set of abundant OTUs that were distinct from those associated with sponges from shallow waters. Comparison of the pyrosequencing data with that from shallow water sponges revealed that the microbial communities of all sponges analysed have similar archaeal populations but that the bacterial populations of the deep sea sponges were distinct. Further analysis of the common and abundant OTUs from the three LMA-like sponges placed them within the groups of ammonia oxidising Archaea (Thaumarchaeota) and sulphur oxidising γ-Proteobacteria (Chromatiales). Reads from these two groups made up over 70% of all 16S rRNA genes detected from the three LMA-like sponge samples, providing evidence of a putative common microbial assemblage associated with deep sea LMA sponges. PMID:24670421

  20. Collagen interactions: Drug design and delivery.

    PubMed

    An, Bo; Lin, Yu-Shan; Brodsky, Barbara

    2016-02-01

    Collagen is a major component in a wide range of drug delivery systems and biomaterial applications. Its basic physical and structural properties, together with its low immunogenicity and natural turnover, are keys to its biocompatibility and effectiveness. In addition to its material properties, the collagen triple-helix interacts with a large number of molecules that trigger biological events. Collagen interactions with cell surface receptors regulate many cellular processes, while interactions with other ECM components are critical for matrix structure and remodeling. Collagen also interacts with enzymes involved in its biosynthesis and degradation, including matrix metalloproteinases. Over the past decade, much information has been gained about the nature and specificity of collagen interactions with its partners. These studies have defined collagen sequences responsible for binding and the high-resolution structures of triple-helical peptides bound to its natural binding partners. Strategies to target collagen interactions are already being developed, including the use of monoclonal antibodies to interfere with collagen fibril formation and the use of triple-helical peptides to direct liposomes to melanoma cells. The molecular information about collagen interactions will further serve as a foundation for computational studies to design small molecules that can interfere with specific interactions or target tumor cells. Intelligent control of collagen biological interactions within a material context will expand the effectiveness of collagen-based drug delivery. PMID:26631222

  1. Metamaterial electromagnetic wave absorbers.

    PubMed

    Watts, Claire M; Liu, Xianliang; Padilla, Willie J

    2012-06-19

    The advent of negative index materials has spawned extensive research into metamaterials over the past decade. Metamaterials are attractive not only for their exotic electromagnetic properties, but also their promise for applications. A particular branch-the metamaterial perfect absorber (MPA)-has garnered interest due to the fact that it can achieve unity absorptivity of electromagnetic waves. Since its first experimental demonstration in 2008, the MPA has progressed significantly with designs shown across the electromagnetic spectrum, from microwave to optical. In this Progress Report we give an overview of the field and discuss a selection of examples and related applications. The ability of the MPA to exhibit extreme performance flexibility will be discussed and the theory underlying their operation and limitations will be established. Insight is given into what we can expect from this rapidly expanding field and future challenges will be addressed. PMID:22627995

  2. Absorber coatings' degradation

    SciTech Connect

    Moore, S.W.

    1984-01-01

    This report is intended to document some of the Los Alamos efforts that have been carried out under the Department of Energy (DOE) Active Heating and Cooling Materials Reliability, Maintainability, and Exposure Testing program. Funding for these activities is obtained directly from DOE although they represent a variety of projects and coordination with other agencies. Major limitations to the use of solar energy are the uncertain reliability and lifetimes of solar systems. This program is aimed at determining material operating limitations, durabilities, and failure modes such that materials improvements can be made and lifetimes can be extended. Although many active and passive materials and systems are being studied at Los Alamos, this paper will concentrate on absorber coatings and degradation of these coatings.

  3. In Situ Natural Product Discovery via an Artificial Marine Sponge

    PubMed Central

    La Clair, James J.; Loveridge, Steven T.; Tenney, Karen; O'Neil–Johnson, Mark; Chapman, Eli; Crews, Phillip

    2014-01-01

    There is continuing international interest in exploring and developing the therapeutic potential of marine–derived small molecules. Balancing the strategies for ocean based sampling of source organisms versus the potential to endanger fragile ecosystems poses a substantial challenge. In order to mitigate such environmental impacts, we have developed a deployable artificial sponge. This report provides details on its design followed by evidence that it faithfully recapitulates traditional natural product collection protocols. Retrieving this artificial sponge from a tropical ecosystem after deployment for 320 hours afforded three actin–targeting jasplakinolide depsipeptides that had been discovered two decades earlier using traditional sponge specimen collection and isolation procedures. The successful outcome achieved here could reinvigorate marine natural products research, by producing new environmentally innocuous sources of natural products and providing a means to probe the true biosynthetic origins of complex marine–derived scaffolds. PMID:25004127

  4. Bioactive natural products from Papua New Guinea marine sponges.

    PubMed

    Noro, Jeffery C; Kalaitzis, John A; Neilan, Brett A

    2012-10-01

    The discovery of novel natural products for drug development relies heavily upon a rich biodiversity, of which the marine environment is an obvious example. Marine natural product research has spawned several drugs and many other candidates, some of which are the focus of current clinical trials. The sponge megadiversity of Papua New Guinea is a rich but underexplored source of bioactive natural products. Here, we review some of the many natural products derived from PNG sponges with an emphasis on those with interesting biological activity and, therefore, drug potential. Many bioactive natural products discussed here appear to be derived from non-ribosomal peptide and polyketide biosynthesis pathways, strongly suggesting a microbial origin of these compounds. With this in mind, we also explore the notion of sponge-symbiont biosynthesis of these bioactive compounds and present examples to support the working hypothesis. PMID:23081914

  5. Cyclodepsipeptides from marine sponges: natural agents for drug research.

    PubMed

    Andavan, Gowri Shankar Bagavananthem; Lemmens-Gruber, Rosa

    2010-01-01

    A number of natural products from marine sponges, such as cyclodepsipeptides, have been identified. The structural characteristics of this family of cyclic peptides include various unusual amino acid residues and unique N-terminal polyketide-derived moieties. Papuamides are representatives of a class of marine sponge derived cyclic depsipeptides, including callipeltin A, celebesides A and B, homophymine A, mirabamides, microspinosamide, neamphamide A and theopapuamides. They are thought to have cytoprotective activity against HIV-1 in vitro by inhibiting viral entry. Jasplakinolide, a representative member of marine sponge-derived cyclodepsipeptides that include arenastatin A, geodiamolides, homophymines, spongidepsin and theopapuamides, is a potent inducer of actin polymerization in vitro. Although actin dynamics is essential for tumor metasasis, no actin targeting drugs have been used in clinical trials due to their severe cytotoxicity. Nonetheless, the actin cytoskeleton remains a potential target for anti-cancer drug development. These features imply the use of cyclodepsipeptides as molecular models in drug research. PMID:20411126

  6. Calyculin: Nature's way of making the sponge-derived cytotoxin.

    PubMed

    Wakimoto, Toshiyuki; Egami, Yoko; Abe, Ikuro

    2016-06-01

    Covering: up to 2015.Calyculin A is a major cytotoxic compound isolated from the Japanese marine sponge Discodermia calyx. Its potent cytotoxicity is attributable to the specific inhibition of protein phosphatases 1 and 2A, as in the case of okadaic acid and the microcystins. Its chemical structure is well-designed not only for enzyme inhibition but also for higher membrane permeability in order to impart its potent cytotoxicity. The biosynthetic gene cluster of this densely functionalized polyketide and nonribosomal peptide hybrid molecule was recently identified from the sponge-microbe association. The producer organism and the dynamic bioconversion process were also revealed. In this highlight, we focus on the recent studies addressing nature's design and biogenesis of the sponge-derived cytotoxin, calyculin A. PMID:26923942

  7. In situ natural product discovery via an artificial marine sponge.

    PubMed

    La Clair, James J; Loveridge, Steven T; Tenney, Karen; O'Neil-Johnson, Mark; Chapman, Eli; Crews, Phillip

    2014-01-01

    There is continuing international interest in exploring and developing the therapeutic potential of marine-derived small molecules. Balancing the strategies for ocean based sampling of source organisms versus the potential to endanger fragile ecosystems poses a substantial challenge. In order to mitigate such environmental impacts, we have developed a deployable artificial sponge. This report provides details on its design followed by evidence that it faithfully recapitulates traditional natural product collection protocols. Retrieving this artificial sponge from a tropical ecosystem after deployment for 320 hours afforded three actin-targeting jasplakinolide depsipeptides that had been discovered two decades earlier using traditional sponge specimen collection and isolation procedures. The successful outcome achieved here could reinvigorate marine natural products research, by producing new environmentally innocuous sources of natural products and providing a means to probe the true biosynthetic origins of complex marine-derived scaffolds. PMID:25004127

  8. Three-dimensional periodic supramolecular organic framework ion sponge in water and microcrystals

    SciTech Connect

    Tian, Jia; Zhou, Tian-You; Zhang, Shao-Chen; Aloni, Shaul; Altoe, Maria Virginia; Xie, Song-Hai; Wang, Hui; Zhang, Dan-Wei; Zhao, Xin; Liu, Yi; Li, Zhan-Ting

    2014-12-02

    Self-assembly has emerged as a powerful approach to generating complex supramolecular architectures. Despite there being many crystalline frameworks reported in the solid state, the construction of highly soluble periodic supramolecular networks in a three-dimensional space is still a challenge. In this paper we demonstrate that the encapsulation motif, which involves the dimerization of two aromatic units within cucurbit[8]uril, can be used to direct the co-assembly of a tetratopic molecular block and cucurbit[8]uril into a periodic three-dimensional supramolecular organic framework in water. The periodicity of the supramolecular organic framework is supported by solution-phase small-angle X-ray-scattering and diffraction experiments. Upon evaporating the solvent, the periodicity of the framework is maintained in porous microcrystals. Lastly, as a supramolecular 'ion sponge', the framework can absorb different kinds of anionic guests, including drugs, in both water and microcrystals, and drugs absorbed in microcrystals can be released to water with selectivity.

  9. Investigation of dodecane in three-dimensional porous graphene sponge by Raman mapping

    NASA Astrophysics Data System (ADS)

    Guo, Xitao; Bi, Hengchang; Zafar, Amina; Liang, Zheng; Shi, Zhixiang; Sun, Litao; Ni, Zhenhua

    2016-02-01

    Three-dimensional (3D) carbon nano-materials, e.g. a graphene sponge (GS) are promising candidates for the removal of pollutants and the separation of oil and water. A systematic study on how oils or organic solvents disperse in the porous structures of 3D carbon nano-materials, and the factors affecting their sorption process, would be beneficial for designing a superior sorbent with desirable porous structures. Here, confocal Raman spectroscopic imaging was utilized to explore the absorption and desorption processes of dodecane (a constituent in petroleum products) in 3D porous GS with different pore size. It was found that dodecane predominately locates within the interior pores composed of reduced graphene oxide (rGO) sheets, which provide storage spaces for the absorbed molecules. The larger pore GS has a higher absorption capacity and faster desorption rate compared to the smaller one, which is due to the higher pore volume and weaker interaction with the absorbed molecules. A possible mechanism was also proposed to explain the role of porous macrostructures on the absorption and desorption properties of GSs.

  10. Investigation of dodecane in three-dimensional porous graphene sponge by Raman mapping.

    PubMed

    Guo, Xitao; Bi, Hengchang; Zafar, Amina; Liang, Zheng; Shi, Zhixiang; Sun, Litao; Ni, Zhenhua

    2016-02-01

    Three-dimensional (3D) carbon nano-materials, e.g. a graphene sponge (GS) are promising candidates for the removal of pollutants and the separation of oil and water. A systematic study on how oils or organic solvents disperse in the porous structures of 3D carbon nano-materials, and the factors affecting their sorption process, would be beneficial for designing a superior sorbent with desirable porous structures. Here, confocal Raman spectroscopic imaging was utilized to explore the absorption and desorption processes of dodecane (a constituent in petroleum products) in 3D porous GS with different pore size. It was found that dodecane predominately locates within the interior pores composed of reduced graphene oxide (rGO) sheets, which provide storage spaces for the absorbed molecules. The larger pore GS has a higher absorption capacity and faster desorption rate compared to the smaller one, which is due to the higher pore volume and weaker interaction with the absorbed molecules. A possible mechanism was also proposed to explain the role of porous macrostructures on the absorption and desorption properties of GSs. PMID:26669216

  11. Three-dimensional periodic supramolecular organic framework ion sponge in water and microcrystals

    DOE PAGESBeta

    Tian, Jia; Zhou, Tian-You; Zhang, Shao-Chen; Aloni, Shaul; Altoe, Maria Virginia; Xie, Song-Hai; Wang, Hui; Zhang, Dan-Wei; Zhao, Xin; Liu, Yi; et al

    2014-12-02

    Self-assembly has emerged as a powerful approach to generating complex supramolecular architectures. Despite there being many crystalline frameworks reported in the solid state, the construction of highly soluble periodic supramolecular networks in a three-dimensional space is still a challenge. In this paper we demonstrate that the encapsulation motif, which involves the dimerization of two aromatic units within cucurbit[8]uril, can be used to direct the co-assembly of a tetratopic molecular block and cucurbit[8]uril into a periodic three-dimensional supramolecular organic framework in water. The periodicity of the supramolecular organic framework is supported by solution-phase small-angle X-ray-scattering and diffraction experiments. Upon evaporating themore » solvent, the periodicity of the framework is maintained in porous microcrystals. Lastly, as a supramolecular 'ion sponge', the framework can absorb different kinds of anionic guests, including drugs, in both water and microcrystals, and drugs absorbed in microcrystals can be released to water with selectivity.« less

  12. Compressible and monolithic microporous polymer sponges prepared via one-pot synthesis

    PubMed Central

    Lim, Yoonbin; Cha, Min Chul; Chang, Ji Young

    2015-01-01

    Compressible and monolithic microporous polymers (MPs) are reported. MPs were prepared as monoliths via a Sonogashira–Hagihara coupling reaction of 1,3,5-triethynylbenzene (TEB) with the bis(bromothiophene) monomer (PBT-Br). The polymers were reversibly compressible, and were easily cut into any form using a knife. Microscopy studies on the MPs revealed that the polymers had tubular microstructures, resembling those often found in marine sponges. Under compression, elastic buckling of the tube bundles was observed using an optical microscope. MP-0.8, which was synthesized using a 0.8:1 molar ratio of PBT-Br to TEB, showed microporosity with a BET surface area as high as 463 m2g–1. The polymer was very hydrophobic, with a water contact angle of 145° and absorbed 7–17 times its own weight of organic liquids. The absorbates were released by simple compression, allowing recyclable use of the polymer. MPs are potential precursors of structured carbon materials; for example, a partially graphitic material was obtained by pyrolysis of MP-0.8, which showed a similar tubular structure to that of MP-0.8. PMID:26534834

  13. Determining collagen distribution in articular cartilage using contrast-enhanced micro-computed tomography

    PubMed Central

    Nieminen, H.J.; Ylitalo, T.; Karhula, S.; Suuronen, J.-P.; Kauppinen, S.; Serimaa, R.; Hæggström, E.; Pritzker, K.P.H.; Valkealahti, M.; Lehenkari, P.; Finnilä, M.; Saarakkala, S.

    2015-01-01

    Summary Objective Collagen distribution within articular cartilage (AC) is typically evaluated from histological sections, e.g., using collagen staining and light microscopy (LM). Unfortunately, all techniques based on histological sections are time-consuming, destructive, and without extraordinary effort, limited to two dimensions. This study investigates whether phosphotungstic acid (PTA) and phosphomolybdic acid (PMA), two collagen-specific markers and X-ray absorbers, could (1) produce contrast for AC X-ray imaging or (2) be used to detect collagen distribution within AC. Method We labeled equine AC samples with PTA or PMA and imaged them with micro-computed tomography (micro-CT) at pre-defined time points 0, 18, 36, 54, 72, 90, 180, 270 h during staining. The micro-CT image intensity was compared with collagen distributions obtained with a reference technique, i.e., Fourier-transform infrared imaging (FTIRI). The labeling time and contrast agent producing highest association (Pearson correlation, Bland–Altman analysis) between FTIRI collagen distribution and micro-CT -determined PTA distribution was selected for human AC. Results Both, PTA and PMA labeling permitted visualization of AC features using micro-CT in non-calcified cartilage. After labeling the samples for 36 h in PTA, the spatial distribution of X-ray attenuation correlated highly with the collagen distribution determined by FTIRI in both equine (mean ± S.D. of the Pearson correlation coefficients, r = 0.96 ± 0.03, n = 12) and human AC (r = 0.82 ± 0.15, n = 4). Conclusions PTA-induced X-ray attenuation is a potential marker for non-destructive detection of AC collagen distributions in 3D. This approach opens new possibilities in development of non-destructive 3D histopathological techniques for characterization of OA. PMID:26003951

  14. Controlled iodine release from polyurethane sponges for water decontamination.

    PubMed

    Aviv, Oren; Laout, Natalia; Ratner, Stanislav; Harik, Oshrat; Kunduru, Konda Reddy; Domb, Abraham J

    2013-12-28

    Iodinated polyurethane (IPU) sponges were prepared by immersing sponges in aqueous/organic solutions of iodine or exposing sponges to iodine vapors. Iodine was readily adsorbed into the polymers up to 100% (w/w). The adsorption of iodine on the surface was characterized by XPS and SEM analyses. The iodine loaded IPU sponges were coated with ethylene vinyl acetate (EVA), in order to release iodine in a controlled rate for water decontamination combined with active carbon cartridge, which adsorbs the iodine residues after the microbial inactivation. The EVA coated IPU were incorporated in a water purifier and tested for iodine release to water and for microbial inactivation efficiency according to WQA certification program against P231/EPA for 250l, using 25l a day with flow rate of 6-8min/1l. The antimicrobial activity was also studied against Escherichia coli and MS2 phage. Bacterial results exceeded the minimal requirement for bacterial removal of 6log reduction throughout the entire lifespan. At any testing point, no bacteria was detected in the outlet achieving more than 7.1 to more than 8log reduction as calculated upon the inlet concentration. Virus surrogate, MS2, reduction results varied from 4.11log reduction under tap water, and 5.11log reduction under basic water (pH9) to 1.32 for acidic water (pH5). Controlled and stable iodine release was observed with the EVA coated IPU sponges and was effective in deactivating the bacteria and virus present in the contaminated water and thus, these iodinated PU systems could be used in water purification to provide safe drinking water. These sponges may find applications as disinfectants in medicine. PMID:24096017

  15. Diversity and distribution patterns in high southern latitude sponges.

    PubMed

    Downey, Rachel V; Griffiths, Huw J; Linse, Katrin; Janussen, Dorte

    2012-01-01

    Sponges play a key role in Antarctic marine benthic community structure and dynamics and are often a dominant component of many Southern Ocean benthic communities. Understanding the drivers of sponge distribution in Antarctica enables us to understand many of general benthic biodiversity patterns in the region. The sponges of the Antarctic and neighbouring oceanographic regions were assessed for species richness and biogeographic patterns using over 8,800 distribution records. Species-rich regions include the Antarctic Peninsula, South Shetland Islands, South Georgia, Eastern Weddell Sea, Kerguelen Plateau, Falkland Islands and north New Zealand. Sampling intensity varied greatly within the study area, with sampling hotspots found at the Antarctic Peninsula, South Georgia, north New Zealand and Tierra del Fuego, with limited sampling in the Bellingshausen and Amundsen seas in the Southern Ocean. In contrast to previous studies we found that eurybathy and circumpolar distributions are important but not dominant characteristics in Antarctic sponges. Overall Antarctic sponge species endemism is ∼43%, with a higher level for the class Hexactinellida (68%). Endemism levels are lower than previous estimates, but still indicate the importance of the Polar Front in isolating the Southern Ocean fauna. Nineteen distinct sponge distribution patterns were found, ranging from regional endemics to cosmopolitan species. A single, distinct Antarctic demosponge fauna is found to encompass all areas within the Polar Front, and the sub-Antarctic regions of the Kerguelen Plateau and Macquarie Island. Biogeographical analyses indicate stronger faunal links between Antarctica and South America, with little evidence of links between Antarctica and South Africa, Southern Australia or New Zealand. We conclude that the biogeographic and species distribution patterns observed are largely driven by the Antarctic Circumpolar Current and the timing of past continent connectivity. PMID

  16. Diversity and Distribution Patterns in High Southern Latitude Sponges

    PubMed Central

    Downey, Rachel V.; Griffiths, Huw J.; Linse, Katrin; Janussen, Dorte

    2012-01-01

    Sponges play a key role in Antarctic marine benthic community structure and dynamics and are often a dominant component of many Southern Ocean benthic communities. Understanding the drivers of sponge distribution in Antarctica enables us to understand many of general benthic biodiversity patterns in the region. The sponges of the Antarctic and neighbouring oceanographic regions were assessed for species richness and biogeographic patterns using over 8,800 distribution records. Species-rich regions include the Antarctic Peninsula, South Shetland Islands, South Georgia, Eastern Weddell Sea, Kerguelen Plateau, Falkland Islands and north New Zealand. Sampling intensity varied greatly within the study area, with sampling hotspots found at the Antarctic Peninsula, South Georgia, north New Zealand and Tierra del Fuego, with limited sampling in the Bellingshausen and Amundsen seas in the Southern Ocean. In contrast to previous studies we found that eurybathy and circumpolar distributions are important but not dominant characteristics in Antarctic sponges. Overall Antarctic sponge species endemism is ∼43%, with a higher level for the class Hexactinellida (68%). Endemism levels are lower than previous estimates, but still indicate the importance of the Polar Front in isolating the Southern Ocean fauna. Nineteen distinct sponge distribution patterns were found, ranging from regional endemics to cosmopolitan species. A single, distinct Antarctic demosponge fauna is found to encompass all areas within the Polar Front, and the sub-Antarctic regions of the Kerguelen Plateau and Macquarie Island. Biogeographical analyses indicate stronger faunal links between Antarctica and South America, with little evidence of links between Antarctica and South Africa, Southern Australia or New Zealand. We conclude that the biogeographic and species distribution patterns observed are largely driven by the Antarctic Circumpolar Current and the timing of past continent connectivity. PMID

  17. Enhancement by PL 14736 of granulation and collagen organization in healing wounds and the potential role of egr-1 expression.

    PubMed

    Tkalcević, Vanesa Ivetić; Cuzić, Snjezana; Brajsa, Karmen; Mildner, Boris; Bokulić, Ana; Situm, Kristina; Perović, Daniela; Glojnarić, Ines; Parnham, Michael J

    2007-09-10

    Apart from becaplermin (recombinant human platelet-derived growth factor homodimer of B chains, PDGF-BB), for the treatment of lower extremity diabetic ulcers, few agents are available for pharmacological stimulation of wound healing. We have compared the mechanism of action of the potential wound healing agent, PL 14736 (G E P P P G K P A D D A G L V), with that of PDGF-BB on granulation tissue formation following sponge implantation in the normoglycemic rat and in healing full-thickness excisional wounds in db/db genetically diabetic mice. Expression of the immediate response gene, early growth response gene-1 (egr-1) was studied in Caco-2 cells in vitro. While PDGF-BB and PL 14736 had similar selectivity for stimulation of granulation tissue in both sponge granuloma and in healing wounds in db/db mice, PL 14736 was more active in stimulating early collagen organization. It also stimulated expression of egr-1 and its repressor nerve growth factor 1-A binding protein-2 (nab2) in non-differentiated Caco-2 cells more rapidly than PDGF-BB. EGR-1 induces cytokine and growth factor generation and early extracellular matrix (collagen) formation, offering an explanation for the beneficial effects of PL 14736 on wound healing. PMID:17628536

  18. Sintering of sponge and hydride-dehydride titanium powders

    SciTech Connect

    Alman, David E.; Gerdemann, Stephen J.

    2004-04-01

    The sintering behavior of compacts produced from sponge and hydride-dehydride (HDH) Ti powders was examined. Compacts were vacuum sintered at 1200 or 1300 deg C for 30, 60, 120, 240, 480 or 960 minutes. The porosity decreased with sintering time and/or temperature in compacts produced from the HDH powders. Compacts produced from these powders could be sintered to essentially full density. However, the sintering condition did not influence the amount of porosity present in compacts produced from the sponge powders. These samples could only be sintered to a density of 97% theoretical. The sintering behavior was attributed to the chemical impurities in the powders.

  19. Photosensitivity in sponge due to cytochrome c oxidase?

    PubMed

    Björn, Lars Olof; Rasmusson, Allan G

    2009-06-01

    An action spectrum for photosensitivity in sponge larvae published by Leys et al. [J. Comp. Physiol., A, 2002, 188, 199-202] was interpreted by the authors as being due to a combination of light absorption by flavin or carotenoid in the blue region, and another pigment such as pterin in the long-wavelength region. Here we show here that their action spectrum closely matches the absorption spectrum of reduced cytochrome c oxidase that is present in sponges, and compare with other photoreactions which are thought to be due to this chromoprotein. PMID:19492101

  20. A tactile sensor using a conductive graphene-sponge composite.

    PubMed

    Chun, Sungwoo; Hong, Ahyoung; Choi, Yeonhoi; Ha, Chunho; Park, Wanjun

    2016-04-28

    For sensors that emulate human tactile perception, we suggest a simple method for fabricating a highly sensitive force sensor using a conductive polyurethane sponge where graphene flakes are self-assembled into the porous structure of the sponge. The complete sensor device shows a sensitive and reliable detection response for a broad range of pressure and dynamic pressure that correspond to human tactile perception. Sensitivity of the sensor to detect vibration is also confirmed with vertical actuations due to slipping over micro-scale ridge structures attached on the sensors. Based on the sensor's ability to detect both pressure and vibration, the sensor can be utilized as a flexible tactile sensor. PMID:27076360

  1. Collagen immobilization of multi-layered BCP-ZrO2 bone substitutes to enhance bone formation

    NASA Astrophysics Data System (ADS)

    Linh, Nguyen Thuy Ba; Jang, Dong-Woo; Lee, Byong-Taek

    2015-08-01

    A porous microstructure of multi-layered BCP-ZrO2 bone substitutes was fabricated using the sponge replica method in which the highly interconnected structure was immobilized with collagen via ethyl(dimethylaminopropyl)carbodiimide/N-hydroxysuccinimide crosslinking. Their struts are combined with a three-layered BCP/BCP-ZrO2/ZrO2 microstructure. Collagen fibers were firmly attached to the strut surface of the BCP-ZrO2 scaffolds. With control of the three-layered microstructure and collagen immobilization, the compressive strength of the scaffolds increased significantly to 6.8 MPa compared to that of the monolithic BCP scaffolds (1.3 MPa). An in vitro study using MTT, confocal observation, and real-time polymer chain reaction analysis demonstrated that the proliferation and differentiation of the pre-osteoblast-like MC3T3-E1 cells was improved due to the collagen incorporation. Remarkable enhancement of bone regeneration was observed without any immunological reaction in the femurs of rabbits during 1 and 5 months of implantation. Furthermore, the interfaces between new bone and the scaffold struts bonded directly without any gaps.

  2. Analytical methods and apparatus for measuring the oil content of sponge core

    SciTech Connect

    Vinegar, H.J.; DiFoggio, R.; Tutunjian, P.N.

    1989-09-19

    This patent describes a method for use in determining the oil saturation of an earth formation by means of sponge coring, using polyurethane sponge. It comprises: dissolving substantially all of the oil and substantially none of the sponge, in a sponge core sample, into a solvent having a Hansen solubility parameter of different than that of the sponge and selected from the class consisting of: solvents having no protons in their structure, deuterated solvents, and solvents having no C-H bonds in their structure; extracting the solvent and solutes from the core sample; and measuring the resultant oil concentration in the solvent and solutes extracted from the core sample.

  3. Electrochemically regenerable carbon dioxide absorber

    NASA Technical Reports Server (NTRS)

    Woods, R. R.; Marshall, R. D.; Schubert, F. H.; Heppner, D. B.

    1979-01-01

    Preliminary designs were generated for two electrochemically regenerable carbon dioxide absorber concepts. Initially, an electrochemically regenerable absorption bed concept was designed. This concept incorporated the required electrochemical regeneration components in the absorber design, permitting the absorbent to be regenerated within the absorption bed. This hardware was identified as the electrochemical absorber hardware. The second hardware concept separated the functional components of the regeneration and absorption process. This design approach minimized the extravehicular activity component volume by eliminating regeneration hardware components within the absorber. The electrochemical absorber hardware was extensively characterized for major operating parameters such as inlet carbon dioxide partial pressure, process air flow rate, operational pressure, inlet relative humidity, regeneration current density and absorption/regeneration cycle endurance testing.

  4. Liquid Hydrogen Absorber for MICE

    SciTech Connect

    Ishimoto, S.; Suzuki, S.; Yoshida, M.; Green, Michael A.; Kuno, Y.; Lau, Wing

    2010-05-30

    Liquid hydrogen absorbers for the Muon Ionization Cooling Experiment (MICE) have been developed, and the first absorber has been tested at KEK. In the preliminary test at KEK we have successfully filled the absorber with {approx}2 liters of liquid hydrogen. The measured hydrogen condensation speed was 2.5 liters/day at 1.0 bar. No hydrogen leakage to vacuum was found between 300 K and 20 K. The MICE experiment includes three AFC (absorber focusing coil) modules, each containing a 21 liter liquid hydrogen absorber made of aluminum. The AFC module has safety windows to separate its vacuum from that of neighboring modules. Liquid hydrogen is supplied from a cryocooler with cooling power 1.5 W at 4.2 K. The first absorber will be assembled in the AFC module and installed in MICE at RAL.

  5. Broadband patterned magnetic microwave absorber

    SciTech Connect

    Li, Wei; Wu, Tianlong; Wang, Wei; Guan, Jianguo; Zhai, Pengcheng

    2014-07-28

    It is a tough task to greatly improve the working bandwidth for the traditional flat microwave absorbers because of the restriction of available material parameters. In this work, a simple patterning method is proposed to drastically broaden the absorption bandwidth of a conventional magnetic absorber. As a demonstration, an ultra-broadband microwave absorber with more than 90% absorption in the frequency range of 4–40 GHz is designed and experimentally realized, which has a thin thickness of 3.7 mm and a light weight equivalent to a 2-mm-thick flat absorber. In such a patterned absorber, the broadband strong absorption is mainly originated from the simultaneous incorporation of multiple λ/4 resonances and edge diffraction effects. This work provides a facile route to greatly extend the microwave absorption bandwidth for the currently available absorbing materials.

  6. Collagen telopeptides (cross-linking sites) play a role in collagen gel lattice contraction

    NASA Technical Reports Server (NTRS)

    Woodley, D. T.; Yamauchi, M.; Wynn, K. C.; Mechanic, G.; Briggaman, R. A.

    1991-01-01

    Solubilized interstitial collagens will form a fibrillar, gel-like lattice when brought to physiologic conditions. In the presence of human dermal fibroblasts the collagen lattice will contract. The rate of contraction can be determined by computer-assisted planemetry. The mechanisms involved in contraction are as yet unknown. Using this system it was found that the rate of contraction was markedly decreased when collagen lacking telopeptides was substituted for native collagen. Histidinohydroxylysinonorleucine (HHL) is a major stable trifunctional collagen cross-link in mature skin that involves a carboxyl terminal, telopeptide site 16c, the sixteenth amino acid residue from the carboxy terminal of the telopeptide region of alpha 1 (I) in type I collagen. Little, if any, HHL was present in native, purified, reconstituted, soluble collagen fibrils from 1% acetic acid-extracted 2-year-old bovine skin. In contrast, HHL cross-links were present (0.22 moles of cross-link per mole of collagen) in lattices of the same collagen contracted by fibroblasts. However, rat tail tendon does not contain HHL cross-links, and collagen lattices made of rat tail tendon collagen are capable of contraction. This suggests that telopeptide sites, and not mature HHL cross-links per se, are essential for fibroblasts to contract collagen lattices. Beta-aminopropionitrile fumarate (BAPN), a potent lathyrogen that perturbs collagen cross-linking by inhibition of lysyl oxidase, also inhibited the rate of lattice cell contraction in lattices composed of native collagen. However, the concentrations of BAPN that were necessary to inhibit the contraction of collagen lattices also inhibited fibroblast growth suggestive of cellular toxicity. In accordance with other studies, we found no inhibition of the rate of lattice contraction when fibronectin-depleted serum was used. Electron microscopy of contracted gels revealed typical collagen fibers with a characteristic axial periodicity. The data

  7. A composite graft material containing bone particles and collagen in osteoinduction in mouse.

    PubMed

    Tsai, Chung-Hung; Chou, Ming-Yung; Jonas, Mecrehild; Tien, Yung-Tico; Chi, Emily Y

    2002-01-01

    with DFDBA powder showed calcification around the particulates. The collagen-sponge control group revealed no calcification or bone formation during the period of implantation. The light microscopic findings were confirmed by electron microscopy. Quantitative radiographic density DynaGraft and DFDBA graft followed sequentially over a period 120 days. It was concluded that a higher rate of calcification and bone formation was produced in the composite graft implant compared to the DFDBA implant. The composite graft material (DynaGraft), which contains both collagen and DFDBA, proved to be more effective for bone formation than particle components alone. PMID:11787031

  8. Immunostimulation effect of jellyfish collagen.

    PubMed

    Sugahara, Takuya; Ueno, Masashi; Goto, Yoko; Shiraishi, Ryusuke; Doi, Mikiharu; Akiyama, Koichi; Yamauchi, Satoshi

    2006-09-01

    Certain edible large jellyfishes belonging to the order Rhizostomeae are consumed in large quantities in China and Japan. The exumbrella part of the edible jellyfish Stomolophus nomurai was cut and soaked in dilute hydrochloric acid solution (pH 3.0) for 12 h, and heated at 121 degrees C for 20 min. The immunostimulation effects of the jellyfish extract were examined. The jellyfish extract enhanced IgM production of human hybridoma HB4C5 cells 34-fold. IgM and IgG production of human peripheral blood lymphocytes (PBL) were also accelerated, 2.8- and 1.4-fold respectively. Moreover, production of interferon (IFN)-gamma and tumor necrosis factor (TNF)-alpha by human PBL was stimulated 100- and 17-fold respectively. Collagenase treatment inactivated the immunostimulation activity of the jellyfish extract. In addition, purified collagen from bovine Achilles' tendon accelerated IgM production of hybridoma cells. These facts mean that collagen has an immunostimulation effect, and that the active substance in jellyfish extract is collagen. PMID:16960386

  9. Fibril-forming collagens in lamprey.

    PubMed

    Kelly, J; Tanaka, S; Hardt, T; Eikenberry, E F; Brodsky, B

    1988-01-15

    Five types of collagen with triple-helical regions approximately 300 nm in length were found in lamprey tissues which show characteristic D-periodic collagen fibrils. These collagens are members of the fibril forming family of this primitive vertebrate. Lamprey collagens were characterized with respect to solubility, mobility on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, carboxylmethyl-cellulose chromatography, peptide digestion patterns, composition, susceptibility to vertebrate collagenase, thermal stability, and segment long spacing-banding pattern. Comparison with fibril-forming collagens in higher vertebrates (types I, II, III, V, and XI) identified three lamprey collagens as types II, V, and XI. Both lamprey dermis and major body wall collagens had properties similar to type I but not the typical heterotrimer composition. Dermis molecules had only alpha 1(I)-like chains, while body wall molecules had alpha 2(I)-like chains combined with chains resembling lamprey type II. Neither collagen exhibited the interchain disulfide linkages or solubility properties of type III. The conservation of fibril organization in type II/type XI tissues in contrast to the major developments in type I and type III tissues after the divergence of lamprey and higher vertebrates is consistent with these results. The presence of type II and type I-like molecules as major collagens and types V and XI as minor collagens in the lamprey, and the differential susceptibility of these molecules to vertebrate collagenase is analogous to the findings in higher vertebrates. PMID:3335531

  10. Collagen Mimetic Peptides: Progress Towards Functional Applications

    PubMed Central

    Yu, S. Michael; Li, Yang; Kim, Daniel

    2015-01-01

    Traditionally, collagen mimetic peptides (CMPs) have been used for elucidating the structure of the collagen triple helix and the factors responsible for its stabilization. The wealth of fundamental knowledge on collagen structure and cell-extracellular matrix (ECM) interactions accumulated over the past decades has led to a recent burst of research exploring the potential of CMPs to recreate the higher order assembly and biological function of natural collagens for biomedical applications. Although a large portion of such research is still at an early stage, the collagen triple helix has become a promising structural motif for engineering self-assembled, hierarchical constructs similar to natural tissue scaffolds which are expected to exhibit unique or enhanced biological activities. This paper reviews recent progress in the field of collagen mimetic peptides that bears both direct and indirect implications to engineering collagen-like materials for potential biomedical use. Various CMPs and collagen-like proteins that mimic either structural or functional characteristics of natural collagens are discussed with particular emphasis on providing helpful information to bioengineers and biomaterials scientists interested in collagen engineering. PMID:26316880

  11. Plants absorb heavy metals

    SciTech Connect

    Parry, J.

    1995-02-01

    Decontamination of heavy metals-polluted soils remains one of the most intractable problems of cleanup technology. Currently available techniques include extraction of the metals by physical and chemical means, such as acid leaching and electroosmosis, or immobilization by vitrification. There are presently no techniques for cleanup which are low cost and retain soil fertility after metals removal. But a solution to the problem could be on the horizon. A small but growing number of plants native to metalliferous soils are known to be capable of accumulating extremely high concentrations of metals in their aboveground portions. These hyperaccumulators, as they are called, contain up to 1,000 times larger metal concentrations in their aboveground parts than normal species. Their distribution is global, including many different families of flowering plants of varying growth forms, from herbaceous plants to trees. Hyperaccumulators absorb metals they do not need for their own nutrition. The metals are accumulated in the leaf and stem vacuoles, and to a lesser extent in the roots.

  12. A multiscale study on the structural and mechanical properties of the luffa sponge from Luffa cylindrica plant.

    PubMed

    Chen, Qiang; Shi, Quan; Gorb, Stanislav N; Li, Zhiyong

    2014-04-11

    Cellular materials that are often observed in biological systems exhibit excellent mechanical properties at remarkably low densities. Luffa sponge is one of such materials with a complex interconnecting porous structure. In this paper, we studied the relationship between its structural and mechanical properties at different levels of its hierarchical organization from a single fiber to a segment of whole sponge. The tensile mechanical behaviors of three single fibers were examined by an Instron testing machine and the ultrastructure of a fractured single fiber was observed in a scanning electronic microscope. Moreover, the compressive mechanical behaviors of the foam-like blocks from different locations of the sponge were examined. The difference of the compressive stress-strain responses of four sets of segmental samples were also compared. The result shows that the single fiber is a porous composite material mainly consisting of cellulose fibrils and lignin/hemicellulose matrix, and its Young's modulus and strength are comparable to wood. The mechanical behavior of the block samples from the hoop wall is superior to that from the core part. Furthermore, it shows that the influence of the inner surface on the mechanical property of the segmental sample is stronger than that of the core part; in particular, the former's Young's modulus, strength and strain energy absorbed are about 1.6 times higher. The present work can improve our understanding of the structure-function relationship of the natural material, which may inspire fabrication of new biomimetic foams with desirable mechanical efficiency for further applications in anti-crushing devices and super-light sandwich panels. PMID:24636532

  13. Predictors of the distribution and abundance of a tube sponge and its resident goby

    NASA Astrophysics Data System (ADS)

    D'Aloia, C. C.; Majoris, J. E.; Buston, P. M.

    2011-09-01

    Microhabitat specialists offer tractable systems for studying the role of habitat in determining species' distribution and abundance patterns. While factors underlying the distribution patterns of these specialists have been studied for decades, few papers have considered factors influencing both the microhabitat and the inhabitant. On the Belizean barrier reef, the obligate sponge-dwelling goby Elacatinus lori inhabits the yellow tube sponge Aplysina fistularis. We used field data and multivariate analyses to simultaneously consider factors influencing sponge and goby distributions. Sponges were non-randomly distributed across the reef with density peaking at a depth of 10-20 m. Sponge morphology also varied with depth: sponges tended to be larger and have fewer tubes with increasing depth. Knowing these patterns of sponge distribution and morphology, we considered how they influenced the distribution of two categories of gobies: residents (≥18 mm SL) and settlers (<18 mm SL). Maximum tube length, number of sponge tubes, and depth were significant predictors of resident distribution. Residents were most abundant in large sponges with multiple tubes, and were virtually absent from sponges shallower than 10 m. Similarly, maximum tube length and number of sponge tubes were significant predictors of settler distribution, with settlers most abundant in large sponges with multiple tubes. The presence or absence of residents in a sponge was not a significant predictor of settler distribution. These results provide us with a clear understanding of where sponges and gobies are found on the reef and support the hypothesis that microhabitat characteristics are good predictors of fish abundance for species that are tightly linked to microhabitat.

  14. Collagen fibrillogenesis: fibronectin, integrins, and minor collagens as organizers and nucleators

    PubMed Central

    Kadler, Karl E; Hill, Adele; Canty-Laird, Elizabeth G

    2008-01-01

    Collagens are triple helical proteins that occur in the extracellular matrix (ECM) and at the cell–ECM interface. There are more than 30 collagens and collagen-related proteins but the most abundant are collagens I and II that exist as D-periodic (where D = 67 nm) fibrils. The fibrils are of broad biomedical importance and have central roles in embryogenesis, arthritis, tissue repair, fibrosis, tumor invasion, and cardiovascular disease. Collagens I and II spontaneously form fibrils in vitro, which shows that collagen fibrillogenesis is a selfassembly process. However, the situation in vivo is not that simple; collagen I-containing fibrils do not form in the absence of fibronectin, fibronectin-binding and collagen-binding integrins, and collagen V. Likewise, the thin collagen II-containing fibrils in cartilage do not form in the absence of collagen XI. Thus, in vivo, cellular mechanisms are in place to control what is otherwise a protein self-assembly process. This review puts forward a working hypothesis for how fibronectin and integrins (the organizers) determine the site of fibril assembly, and collagens V and XI (the nucleators) initiate collagen fibrillogenesis. PMID:18640274

  15. A mathematical model of collagen lattice contraction

    PubMed Central

    Dallon, J. C.; Evans, E. J.; Ehrlich, H. Paul

    2014-01-01

    Two mathematical models for fibroblast–collagen interaction are proposed which reproduce qualitative features of fibroblast-populated collagen lattice contraction. Both models are force based and model the cells as individual entities with discrete attachment sites; however, the collagen lattice is modelled differently in each model. In the collagen lattice model, the lattice is more interconnected and formed by triangulating nodes to form the fibrous structure. In the collagen fibre model, the nodes are not triangulated, are less interconnected, and the collagen fibres are modelled as a string of nodes. Both models suggest that the overall increase in stress of the lattice as it contracts is not the cause of the reduced rate of contraction, but that the reduced rate of contraction is due to inactivation of the fibroblasts. PMID:25142520

  16. Stress controls the mechanics of collagen networks

    PubMed Central

    Licup, Albert James; Münster, Stefan; Sharma, Abhinav; Sheinman, Michael; Jawerth, Louise M.; Fabry, Ben; Weitz, David A.; MacKintosh, Fred C.

    2015-01-01

    Collagen is the main structural and load-bearing element of various connective tissues, where it forms the extracellular matrix that supports cells. It has long been known that collagenous tissues exhibit a highly nonlinear stress–strain relationship, although the origins of this nonlinearity remain unknown. Here, we show that the nonlinear stiffening of reconstituted type I collagen networks is controlled by the applied stress and that the network stiffness becomes surprisingly insensitive to network concentration. We demonstrate how a simple model for networks of elastic fibers can quantitatively account for the mechanics of reconstituted collagen networks. Our model points to the important role of normal stresses in determining the nonlinear shear elastic response, which can explain the approximate exponential relationship between stress and strain reported for collagenous tissues. This further suggests principles for the design of synthetic fiber networks with collagen-like properties, as well as a mechanism for the control of the mechanics of such networks. PMID:26195769

  17. Occurrence of a taurine derivative in an antarctic glass sponge.

    PubMed

    Carbone, Marianna; Núñez-Pons, Laura; Ciavatta, M Letizia; Castelluccio, Francesco; Avila, Conxita; Gavagnin, Margherita

    2014-04-01

    The n-butanol extract of an Antarctic hexactinellid sponge, Anoxycalyx (Scolymastra) joubini, was found to contain a taurine-conjugated anthranilic acid, never reported so far either as a natural product or by synthesis. The compound was inactive against human cancer cells in an in vitro growth inhibitory test, and also showed no antibacterial activity. PMID:24868857

  18. Significance of starch properties and quantity on sponge cake volume

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We evaluated the qualitative and quantitative effects of wheat starch on sponge cake (SC) baking quality. Twenty wheat flours, including soft white and club wheat of normal, partial waxy and waxy endosperm, and hard wheat, were tested for amylose content, pasting properties, and SC baking quality. S...

  19. A tactile sensor using a conductive graphene-sponge composite

    NASA Astrophysics Data System (ADS)

    Chun, Sungwoo; Hong, Ahyoung; Choi, Yeonhoi; Ha, Chunho; Park, Wanjun

    2016-04-01

    For sensors that emulate human tactile perception, we suggest a simple method for fabricating a highly sensitive force sensor using a conductive polyurethane sponge where graphene flakes are self-assembled into the porous structure of the sponge. The complete sensor device shows a sensitive and reliable detection response for a broad range of pressure and dynamic pressure that correspond to human tactile perception. Sensitivity of the sensor to detect vibration is also confirmed with vertical actuations due to slipping over micro-scale ridge structures attached on the sensors. Based on the sensor's ability to detect both pressure and vibration, the sensor can be utilized as a flexible tactile sensor.For sensors that emulate human tactile perception, we suggest a simple method for fabricating a highly sensitive force sensor using a conductive polyurethane sponge where graphene flakes are self-assembled into the porous structure of the sponge. The complete sensor device shows a sensitive and reliable detection response for a broad range of pressure and dynamic pressure that correspond to human tactile perception. Sensitivity of the sensor to detect vibration is also confirmed with vertical actuations due to slipping over micro-scale ridge structures attached on the sensors. Based on the sensor's ability to detect both pressure and vibration, the sensor can be utilized as a flexible tactile sensor. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr00774k

  20. Keratin sponge/hydrogel II, active agent delivery

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Keratin sponge/hydrogels from oxidation and reduction hydrolysis of fine and coarse wool fibers were formed to behave as cationic hydrogels to swell and release active agents in the specific region of the gastro-intestinal (GI) tract. Their porous, interpenetrating networks (IPN) were effective for...

  1. SITE TECHNOLOGY CAPSULE: DYNAPHORE, INC., FORAGER™ SPONGE TECHNOLOGY

    EPA Science Inventory

    The Forager™ Sponge is a volume reduction technology in which heavy metal contaminants from an aqueous medium are selectively concentrated into a smaller volume for facilitated disposal. The technology treats contaminated groundwater, surface waters, and process waters by absorbi...

  2. Antiepileptic Ceramides from the Red Sea Sponge Negombata corticata

    PubMed Central

    Ahmed, Safwat A.; Khalifa, Sherief I.; Hamann, Mark T.

    2016-01-01

    A new antiepileptic ceramide mixture 1 was isolated from the Red Sea sponge Negombata corticata. The structures of the metabolites were determined by extensive spectroscopic analysis. The anticonvulsant activity of 1 was measured in vivo using the pentylenetetrazole-induced seizure model. This finding has important implications for biological studies with this class of compounds. PMID:18355032

  3. Animals of the Sea: Coelenterates, Protozoa, and Sponges.

    ERIC Educational Resources Information Center

    Awkerman, Gary L.

    These three units are designed for use with standard science curricula. These publications, relating to animals of the sea, are: Protozoa, Sponges, and Coelenterates. Included are teacher guides, student activities, and demonstrations designed to impart ocean science understanding to high school students. Objectives to be attained from the unit on…

  4. Seasonal Growth Rate of the Sponge Haliclona oculata (Demospongiae: Haplosclerida)

    PubMed Central

    Wijffels, René H.

    2008-01-01

    The interest in sponges has increased rapidly since the discovery of potential new pharmaceutical compounds produced by many sponges. A good method to produce these compounds by using aquaculture of sponges is not yet available, because there is insufficient knowledge about the nutritional needs of sponges. To gain more insight in the nutritional needs for growth, we studied the growth rate of Haliclona oculata in its natural environment and monitored environmental parameters in parallel. A stereo photogrammetry approach was used for measuring growth rates. Stereo pictures were taken and used to measure volumetric changes monthly during 1 year. Volumetric growth rate of Haliclona oculata showed a seasonal trend with the highest average specific growth rate measured in May: 0.012 ± 0.004 day−1. In our study a strong positive correlation (p < 0.01) was found for growth rate with temperature, algal biomass (measured as chlorophyll a), and carbon and nitrogen content in suspended particulate matter. A negative correlation (p < 0.05) was found for growth rate with salinity, ammonium, nitrate, nitrite, and phosphate. No correlation was found with dissolved organic carbon, suggesting that Haliclona oculata is more dependent on particulate organic carbon. PMID:18293037

  5. Cytotoxic dibromotyrosine-derived metabolites from the sponge Aplysina gerardogreeni.

    PubMed

    Hernández-Guerrero, Claudia J; Zubía, Eva; Ortega, María J; Carballo, J Luis

    2007-08-01

    The chemical study of the sponge Aplysina gerardogreeni collected at the Gulf of California has led to the isolation of four new dibromotyrosine-derived metabolites, aplysinones A-D, whose structures were determined by spectroscopic analysis and chemical methods. The new compounds and four semisynthetic analogues prepared in this study have shown cytotoxic activity against human tumor cell lines. PMID:17512741

  6. New Scalarane Sesterterpenoids from the Formosan Sponge Ircinia felix

    PubMed Central

    Lai, Ya-Yuan; Lu, Mei-Chin; Wang, Li-Hsueh; Chen, Jih-Jung; Fang, Lee-Shing; Wu, Yang-Chang; Sung, Ping-Jyun

    2015-01-01

    Five new scalarane sesterterpenoids, felixins A–E (1–5), were isolated from the Formosan sponge Ircinia felix. The structures of scalaranes 1–5 were elucidated on the basis of spectroscopic analysis. Cytotoxicity of scalaranes 1–5 against the proliferation of a limited panel of tumor cell lines was evaluated. PMID:26184237

  7. Tactile device utilizing a single magnetorheological sponge: experimental investigation

    NASA Astrophysics Data System (ADS)

    Kim, Soomin; Kim, Pyunghwa; Choi, Seung-Hyun; Oh, Jong-Seok; Choi, Seung-Bok

    2015-04-01

    In the field of medicine, several new areas have been currently introduced such as robot-assisted surgery. However, the major drawback of these systems is that there is no tactile communication between doctors and surgical sites. When the tactile system is brought up, telemedicine including telerobotic surgery can be enhanced much more than now. In this study, a new tactile device is designed using a single magnetorhological (MR) sponge cell to realize the sensation of human organs. MR fluids and an open celled polyurethane foam are used to propose the MR sponge cell. The viscous and elastic sensational behaviors of human organs are realized by the MR sponge cell. Before developing the tactile device, tactile sensation according to touch of human fingers are quantified in advance. The finger is then treated as a reduced beam bundle model (BBM) in which the fingertip is comprised of an elastic beam virtually. Under the reduced BBM, when people want to sense an object, the fingertip is investigated by pushing and sliding. Accordingly, while several magnitudes of magnetic fields are applied to the tactile device, normal and tangential reaction forces and bending moment are measured by 6-axis force/torque sensor instead of the fingertip. These measured data are used to compare with soft tissues. It is demonstrated that the proposed MR sponge cell can realize any part of the organ based on the obtained data.

  8. Energy absorber for the CETA

    NASA Astrophysics Data System (ADS)

    Wesselski, Clarence J.

    1994-05-01

    The energy absorber that was developed for the CETA (Crew Equipment and Translation Aid) on Space Station Freedom is a metal on metal frictional type and has a load regulating feature that prevents excessive stroking loads from occurring while in operation. This paper highlights some of the design and operating aspects and the testing of this energy absorber.

  9. Energy absorber for the CETA

    NASA Technical Reports Server (NTRS)

    Wesselski, Clarence J.

    1994-01-01

    The energy absorber that was developed for the CETA (Crew Equipment and Translation Aid) on Space Station Freedom is a metal on metal frictional type and has a load regulating feature that prevents excessive stroking loads from occurring while in operation. This paper highlights some of the design and operating aspects and the testing of this energy absorber.

  10. Metal-shearing energy absorber

    NASA Technical Reports Server (NTRS)

    Fay, R. J.; Wittrock, E. P.

    1971-01-01

    Device, consisting of tongue of thin aluminum alloy strip, pull tab, slotted steel plate which serves as cutter, and steel buckle, absorbs mechanical energy when its ends are subjected to tensile loading. Device is applicable as auxiliary shock absorbing anchor for automobile and airplane safety belts.

  11. Leaf absorbance and photosynthesis

    NASA Technical Reports Server (NTRS)

    Schurer, Kees

    1994-01-01

    The absorption spectrum of a leaf is often thought to contain some clues to the photosynthetic action spectrum of chlorophyll. Of course, absorption of photons is needed for photosynthesis, but the reverse, photosynthesis when there is absorption, is not necessarily true. As a check on the existence of absorption limits we measured spectra for a few different leaves. Two techniques for measuring absorption have been used, viz. the separate determination of the diffuse reflectance and the diffuse transmittance with the leaf at a port of an integrating sphere and the direct determination of the non-absorbed fraction with the leaf in the sphere. In a cross-check both methods yielded the same results for the absorption spectrum. The spectrum of a Fuchsia leaf, covering the short-wave region from 350 to 2500 nm, shows a high absorption in UV, blue and red, the well known dip in the green and a steep fall-off at 700 nm. Absorption drops to virtually zero in the near infrared, with subsequent absorptions, corresponding to the water absorption bands. In more detailed spectra, taken at 5 nm intervals with a 5 nm bandwidth, differences in chlorophyll content show in the different depths of the dip around 550 nm and in a small shift of the absorption edge at 700 nm. Spectra for Geranium (Pelargonium zonale) and Hibiscus (with a higher chlorophyll content) show that the upper limit for photosynthesis can not be much above 700 nm. No evidence, however, is to be seen of a lower limit for photosynthesis and, in fact, some experiments down to 300 nm still did not show a decrease of the absorption although it is well recognized that no photosynthesis results with 300 nm wavelengths.

  12. Visible light broadband perfect absorbers

    NASA Astrophysics Data System (ADS)

    Jia, X. L.; Meng, Q. X.; Yuan, C. X.; Zhou, Z. X.; Wang, X. O.

    2016-03-01

    The visible light broadband perfect absorbers based on the silver (Ag) nano elliptical disks and holes array are studied using finite difference time domain simulations. The semiconducting indium silicon dioxide thin film is introduced as the space layer in this sandwiched structure. Utilizing the asymmetrical geometry of the structures, polarization sensitivity for transverse electric wave (TE)/transverse magnetic wave (TM) and left circular polarization wave (LCP)/right circular polarization wave (RCP) of the broadband absorption are gained. The absorbers with Ag nano disks and holes array show several peaks absorbance of 100% by numerical simulation. These simple and flexible perfect absorbers are particularly desirable for various potential applications including the solar energy absorber.

  13. A facile synthesis of three dimensional graphene sponge composited with sulfur nanoparticles for flexible Li-S cathodes.

    PubMed

    Lin, Chao; Niu, Chaojiang; Xu, Xu; Li, Ke; Cai, Zhengyang; Zhang, Yonglai; Wang, Xuanpeng; Qu, Longbing; Xu, Yuxi; Mai, Liqiang

    2016-08-10

    Compared with a two dimensional graphene sheet, a three dimensional (3D) graphene sponge has a continuous conductive structure and numerous pores, which are beneficial for sulfur utilization and anchoring. However, strategies for the construction of 3D graphene sponges composited with sulfur nanoparticles (3DGS) are either energy consuming or involve toxic reagents. Herein, a 3DGS is fabricated via a reduction induced self-assembly method, which is simple but facile and scalable. The structural design of this 3DGS promises fast Li(+) transport, superior electrolyte absorbability and effective electrochemical redox reactions of sulfur. As a result, this 3DGS achieves a stable capacity of 580 mA h g(-1) after 500 cycles at a high rate of 1.5 A g(-1), which corresponds to a low fading rate of 0.043% per cycle. The present study effectively demonstrates that the 3D construction strategy is propitious for obtaining flexible high performance Li-S batteries. PMID:27443983

  14. Ionic solutes impact collagen scaffold bioactivity.

    PubMed

    Pawelec, K M; Husmann, A; Wardale, R J; Best, S M; Cameron, R E

    2015-02-01

    The structure of ice-templated collagen scaffolds is sensitive to many factors. By adding 0.5 wt% of sodium chloride or sucrose to collagen slurries, scaffold structure could be tuned through changes in ice growth kinetics and interactions of the solute and collagen. With ionic solutes (sodium chloride) the entanglements of the collagen molecule decreased, leading to fibrous scaffolds with increased pore size and decreased attachment of chondrocytes. With non-ionic solutes (sucrose) ice growth was slowed, leading to significantly reduced pore size and up-regulated cell attachment. This highlights the large changes in structure and biological function stimulated by solutes in ice-templating systems. PMID:25649518

  15. Sponge bioerosion accelerated by ocean acidification across species and latitudes?

    NASA Astrophysics Data System (ADS)

    Wisshak, M.; Schönberg, C. H. L.; Form, A.; Freiwald, A.

    2014-06-01

    In many marine biogeographic realms, bioeroding sponges dominate the internal bioerosion of calcareous substrates such as mollusc beds and coral reef framework. They biochemically dissolve part of the carbonate and liberate so-called sponge chips, a process that is expected to be facilitated and accelerated in a more acidic environment inherent to the present global change. The bioerosion capacity of the demosponge Cliona celata Grant, 1826 in subfossil oyster shells was assessed via alkalinity anomaly technique based on 4 days of experimental exposure to three different levels of carbon dioxide partial pressure ( pCO2) at ambient temperature in the cold-temperate waters of Helgoland Island, North Sea. The rate of chemical bioerosion at present-day pCO2 was quantified with 0.08-0.1 kg m-2 year-1. Chemical bioerosion was positively correlated with increasing pCO2, with rates more than doubling at carbon dioxide levels predicted for the end of the twenty-first century, clearly confirming that C. celata bioerosion can be expected to be enhanced with progressing ocean acidification (OA). Together with previously published experimental evidence, the present results suggest that OA accelerates sponge bioerosion (1) across latitudes and biogeographic areas, (2) independent of sponge growth form, and (3) for species with or without photosymbionts alike. A general increase in sponge bioerosion with advancing OA can be expected to have a significant impact on global carbonate (re)cycling and may result in widespread negative effects, e.g. on the stability of wild and farmed shellfish populations, as well as calcareous framework builders in tropical and cold-water coral reef ecosystems.

  16. Giving the early fossil record of sponges a squeeze.

    PubMed

    Antcliffe, Jonathan B; Callow, Richard H T; Brasier, Martin D

    2014-11-01

    Twenty candidate fossils with claim to be the oldest representative of the Phylum Porifera have been re-analysed. Three criteria are used to assess each candidate: (i) the diagnostic criteria needed to categorize sponges in the fossil record; (ii) the presence, or absence, of such diagnostic features in the putative poriferan fossils; and (iii) the age constraints for the candidate fossils. All three criteria are critical to the correct interpretation of any fossil and its placement within an evolutionary context. Our analysis shows that no Precambrian fossil candidate yet satisfies all three of these criteria to be a reliable sponge fossil. The oldest widely accepted candidate, Mongolian silica hexacts from c. 545 million years ago (Ma), are here shown to be cruciform arsenopyrite crystals. The oldest reliable sponge remains are siliceous spicules from the basal Cambrian (Protohertzina anabarica Zone) Soltanieh Formation, Iran, which are described and analysed here in detail for the first time. Extensive archaeocyathan sponge reefs emerge and radiate as late as the middle of the Fortunian Stage of the Cambrian and demonstrate a gradual assembly of their skeletal structure through this time coincident with the evolution of other metazoan groups. Since the Porifera are basal in the Metazoa, their presence within the late Proterozoic has been widely anticipated. Molecular clock calibration for the earliest Porifera and Metazoa should now be based on the Iranian hexactinellid material dated to c. 535 Ma. The earliest convincing fossil sponge remains appeared at around the time of the Precambrian-Cambrian boundary, associated with the great radiation events of that interval. PMID:24779547

  17. Sponge-Microbe Associations Survive High Nutrients and Temperatures

    PubMed Central

    Simister, Rachel; Taylor, Michael W.; Tsai, Peter; Webster, Nicole

    2012-01-01

    Coral reefs are under considerable pressure from global stressors such as elevated sea surface temperature and ocean acidification, as well as local factors including eutrophication and poor water quality. Marine sponges are diverse, abundant and ecologically important components of coral reefs in both coastal and offshore environments. Due to their exceptionally high filtration rates, sponges also form a crucial coupling point between benthic and pelagic habitats. Sponges harbor extensive microbial communities, with many microbial phylotypes found exclusively in sponges and thought to contribute to the health and survival of their hosts. Manipulative experiments were undertaken to ascertain the impact of elevated nutrients and seawater temperature on health and microbial community dynamics in the Great Barrier Reef sponge Rhopaloeides odorabile. R. odorabile exposed to elevated nutrient levels including 10 µmol/L total nitrogen at 31°C appeared visually similar to those maintained under ambient seawater conditions after 7 days. The symbiotic microbial community, analyzed by 16S rRNA gene pyrotag sequencing, was highly conserved for the duration of the experiment at both phylum and operational taxonomic unit (OTU) (97% sequence similarity) levels with 19 bacterial phyla and 1743 OTUs identified across all samples. Additionally, elevated nutrients and temperatures did not alter the archaeal associations in R. odorabile, with sequencing of 16S rRNA gene libraries revealing similar Thaumarchaeota diversity and denaturing gradient gel electrophoresis (DGGE) revealing consistent amoA gene patterns, across all experimental treatments. A conserved eukaryotic community was also identified across all nutrient and temperature treatments by DGGE. The highly stable microbial associations indicate that R. odorabile symbionts are capable of withstanding short-term exposure to elevated nutrient concentrations and sub-lethal temperatures. PMID:23284943

  18. Sponge-microbe associations survive high nutrients and temperatures.

    PubMed

    Simister, Rachel; Taylor, Michael W; Tsai, Peter; Webster, Nicole

    2012-01-01

    Coral reefs are under considerable pressure from global stressors such as elevated sea surface temperature and ocean acidification, as well as local factors including eutrophication and poor water quality. Marine sponges are diverse, abundant and ecologically important components of coral reefs in both coastal and offshore environments. Due to their exceptionally high filtration rates, sponges also form a crucial coupling point between benthic and pelagic habitats. Sponges harbor extensive microbial communities, with many microbial phylotypes found exclusively in sponges and thought to contribute to the health and survival of their hosts. Manipulative experiments were undertaken to ascertain the impact of elevated nutrients and seawater temperature on health and microbial community dynamics in the Great Barrier Reef sponge Rhopaloeides odorabile. R. odorabile exposed to elevated nutrient levels including 10 µmol/L total nitrogen at 31°C appeared visually similar to those maintained under ambient seawater conditions after 7 days. The symbiotic microbial community, analyzed by 16S rRNA gene pyrotag sequencing, was highly conserved for the duration of the experiment at both phylum and operational taxonomic unit (OTU) (97% sequence similarity) levels with 19 bacterial phyla and 1743 OTUs identified across all samples. Additionally, elevated nutrients and temperatures did not alter the archaeal associations in R. odorabile, with sequencing of 16S rRNA gene libraries revealing similar Thaumarchaeota diversity and denaturing gradient gel electrophoresis (DGGE) revealing consistent amoA gene patterns, across all experimental treatments. A conserved eukaryotic community was also identified across all nutrient and temperature treatments by DGGE. The highly stable microbial associations indicate that R. odorabile symbionts are capable of withstanding short-term exposure to elevated nutrient concentrations and sub-lethal temperatures. PMID:23284943

  19. Evaluation of dense collagen matrices as medicated wound dressing for the treatment of cutaneous chronic wounds.

    PubMed

    Helary, Christophe; Abed, Aicha; Mosser, Gervaise; Louedec, Liliane; Letourneur, Didier; Coradin, Thibaud; Giraud-Guille, Marie Madeleine; Meddahi-Pellé, Anne

    2015-02-01

    Cutaneous chronic wounds are characterized by an impaired wound healing which may lead to infection and amputation. When current treatments are not effective enough, the application of wound dressings is required. To date, no ideal biomaterial is available. In this study, highly dense collagen matrices have been evaluated as novel medicated wound dressings for the treatment of chronic wounds. For this purpose, the structure, mechanical properties, swelling ability and in vivo stability of matrices concentrated from 5 to 40 mg mL(-1) were tested. The matrix stiffness increased with the collagen concentration and was associated with the fibril density and thickness. Increased collagen concentration also enhanced the material resistance against accelerated digestion by collagenase. After subcutaneous implantation in rats, dense collagen matrices exhibited high stability without any degradation after 15 days. The absence of macrophages and neutrophils evidenced their biocompatibility. Subsequently, dense matrices at 40 mg mL(-1) were evaluated as drug delivery system for ampicillin release. More concentrated matrices exhibited the best swelling abilities and could absorb 20 times their dry weight in water, allowing for an efficient antibiotic loading from their dried form. They released efficient doses of antibiotics that inhibited the bacterial growth of Staphylococcus Aureus over 3 days. In parallel, they show no cytotoxicity towards human fibroblasts. These results show that dense collagen matrices are promising materials to develop medicated wound dressings for the treatment of chronic wounds. PMID:26218128

  20. Bone resorption analysis of platelet-derived growth factor type BB application on collagen for bone grafts secured by titanium mesh over a pig jaw defect model

    PubMed Central

    Herford, Alan Scott; Cicciù, Marco

    2012-01-01

    Purpose: The aim of this investigation was to evaluate whether the addition of the platelet derived growth factor type BB (PDGF-BB) to a collagen matrix applied on a titanium mesh would favor healing and resorption onto the grafted bone. A histologic and radiographic study of two different groups (test and control) was performed. Designs: A surgical procedure was performed on 8 pigs to obtain 16 bilateral mandibular alveolar defects. All the defects were then reconstructed with a mixture of autogenous bovine bone using titanium mesh positioning. Two groups, with a total of 16 defects were created: The first to study collagen sponge and PDGF-BB and the second to control collagen only. The collagen matrix was positioned directly over the mesh and soft tissue was closed without tensions onto both groups without attempting to obtain primary closure. Possible exposure of the titanium mesh as well as the height and volume of the new bone was recorded. Results: New bone formation averaged about 6.68 mm in the test group studied; the control group had less regenerated bone at 4.62 mm. Conclusion: PDGF-BB addition to the collagen matrix induced a strong increase in hard and soft tissue healing and favored bone formation, reducing bone resorption even if the mesh was exposed. PMID:23833493

  1. [Interaction of fish collagen peptide with epigallocatechin gallate].

    PubMed

    Yang, Wei; Yuan, Fang; Gao, Yan-xiang

    2015-01-01

    Fish collagen is known to have good moisturising property and antioxidant ability, which has been increasingly added into cosmetics, foods and drinks as thicker agent and to increase dietary supply of collagen. Fish collagen peptide (FCP) is a white or pale yellow powder, obtained by extracting collagen from sources including the scales and bones of fish such as bonito, halibut, tuna, and sea bream. It is identical to human collagen and 100% absorbable through the skin. (-)-Epigallocatechin-3-gallate (EGCG), the major constituent of green tea, has lots of beneficial biological and pharmacological effects, including antioxidant, antimutagenic, antiviral and antiinflammatory activities. Because proteins have the desirable formulation of EGCG-fortified food, the interaction between proteins and EGCG molecules has been widely studied. At the same time, the interaction of proteins and EGCG was known to affect the content of free EGCG, structure of proteins, antioxidant capacity of EGCG in foods. But, to our knowledge, the interaction between FCP and EGCG has not been characterised clearly, and little is known about their interaction mechanism. Therefore, a better understanding of the interaction between FCP and EGCG would help to control their functional properties in food products during processing, transportation and storage when we facilitate FCP as the vehicles for EGCG. In view of the above, we planned to study the interaction of FCP with EGCG by using different spectroscopic techniques, such as fluorescence spectroscopic, FTIR, CD and Raman. EGCG caused a concentration dependent quenching of the intrinsic fluorescence of tyrosine residue in the FCP, indicating the occurrence of interactions between FCP and EGCG. Excimer-like species and dityrosine were regularly formed with the addition of EGCG into the solution, and the interaction of FCP and EGCG partly disrupted the structure-of the protein. Synchronous fluorescence results indicate that the interaction caused

  2. Second-harmonic generation microscopy of collagen-bearing structures

    NASA Astrophysics Data System (ADS)

    Vanbel, Maarten K.; Callewaert, Tom; Verbiest, Thierry

    2014-05-01

    Nonlinear optical phenomena cover a broad research area. The emphasis is mostly on the generation of higher harmonics to be used in laser designs or on the characterization capabilities of nonlinear optics. The latter ability of nonlinear optics is important when combined with a microscope to detect simultaneously multiphoton fluorescence and second-harmonic generation. Submicron size features can then be investigated separately and information on their structure can be revealed by second-harmonic generation. For example, the point group symmetry can be determined in situ and in vivo in complex media. Moreover, nonlinear optical microscopy has several additional advantages: the generation and detection of nonlinear signals is intrinsically confocal and degradation, if present, only occurs at a localized places in the structure. In biological structures, multiphoton fluorescence and second-harmonic generation do not necessarily occur in the same type of the structure. This can be exploited to visualize different structures in one sample by simultaneous detection of two-photon fluorescence and second-harmonic generation. Also, the incident beam can be tuned to fit in the biological window of biological structures, which gives second-harmonic generation microscopy a significant advantage over linear microscopy due to absorbance issues in the visible wavelength range. We exploit these advantages to characterize collagen-bearing biological structures. Collagen is the dominant structural protein in connective tissue in mammals. Being the most abundant protein in the mammal clade, it is essential for the very existence of it. Collagen is a protein with a very strict quaternary structure. The most simple Ramachandran model states that an amino-acid sequence of Glycine-prolin-hydroxyprolin leads to a right-handed helical structure. The inherent stability is such that a sole helix cannot exist for a prolonged period of time, it will therefore combine with 2 near identical

  3. Collagen XII: Protecting bone and muscle integrity by organizing collagen fibrils.

    PubMed

    Chiquet, Matthias; Birk, David E; Bönnemann, Carsten G; Koch, Manuel

    2014-08-01

    Collagen XII, largest member of the fibril-associated collagens with interrupted triple helix (FACIT) family, assembles from three identical α-chains encoded by the COL12A1 gene. The molecule consists of three threadlike N-terminal noncollagenous NC3 domains, joined by disulfide bonds and a short interrupted collagen triple helix toward the C-terminus. Splice variants differ considerably in size and properties: "small" collagen XIIB (220 kDa subunit) is similar to collagen XIV, whereas collagen XIIA (350 kDa) has a much larger NC3 domain carrying glycosaminoglycan chains. Collagen XII binds to collagen I-containing fibrils via its collagenous domain, whereas its large noncollagenous arms interact with other matrix proteins such as tenascin-X. In dense connective tissues and bone, collagen XII is thought to regulate organization and mechanical properties of collagen fibril bundles. Accordingly, recent findings show that collagen XII mutations cause Ehlers-Danlos/myopathy overlap syndrome associated with skeletal abnormalities and muscle weakness in mice and humans. PMID:24801612

  4. Molecules in Focus: Collagen XII: Protecting bone and muscle integrity by organizing collagen fibrils

    PubMed Central

    Chiquet, Matthias; Birk, David E.; Bönnemann, Carsten G.; Koch, Manuel

    2014-01-01

    Collagen XII, largest member of the fibril-associated collagens with interrupted triple helix (FACIT) family, assembles from three identical α-chains encoded by the COL12A1 gene. The molecule consists of three threadlike N-terminal noncollagenous NC3 domains, joined by disulfide bonds and a short interrupted collagen triple helix towards the C-terminus. Splice variants differ considerably in size and properties: "small" collagen XIIB (220 kDa subunit) is similar to collagen XIV, whereas collagen XIIA (350 kDa) has a much larger NC3 domain carrying glycosaminoglycan chains. Collagen XII binds to collagen I-containing fibrils via its collagenous domain, whereas its large noncollagenous arms interact with other matrix proteins such as tenascin-X. In dense connective tissues and bone, collagen XII is thought to regulate organization and mechanical properties of collagen fibril bundles. Accordingly, recent findings show that collagen XII mutations cause Ehlers-Danlos/myopathy overlap syndrome associated with skeletal abnormalities and muscle weakness in mice and humans. PMID:24801612

  5. Fluorescence, aggregation properties and FT-IR microspectroscopy of elastin and collagen fibers.

    PubMed

    Vidal, Benedicto de Campos

    2014-10-01

    Histological and histochemical observations support the hypothesis that collagen fibers can link to elastic fibers. However, the resulting organization of elastin and collagen type complexes and differences between these materials in terms of macromolecular orientation and frequencies of their chemical vibrational groups have not yet been solved. This study aimed to investigate the macromolecular organization of pure elastin, collagen type I and elastin-collagen complexes using polarized light DIC-microscopy. Additionally, differences and similarities between pure elastin and collagen bundles (CB) were investigated by Fourier transform-infrared (FT-IR) microspectroscopy. Although elastin exhibited a faint birefringence, the elastin-collagen complex aggregates formed in solution exhibited a deep birefringence and formation of an ordered-supramolecular complex typical of collagen chiral structure. The FT-IR study revealed elastin and CB peptide NH groups involved in different types of H-bonding. More energy is absorbed in the vibrational transitions corresponding to CH, CH2 and CH3 groups (probably associated with the hydrophobicity demonstrated by 8-anilino-1-naphtalene sulfonic acid sodium salt [ANS] fluorescence), and to νCN, δNH and ωCH2 groups of elastin compared to CB. It is assumed that the α-helix contribution to the pure elastin amide I profile is 46.8%, whereas that of the B-sheet is 20% and that unordered structures contribute to the remaining percentage. An FT-IR profile library reveals that the elastin signature within the 1360-1189cm(-1) spectral range resembles that of Conex-Toray aramid fibers. PMID:25213809

  6. thin films as absorber

    NASA Astrophysics Data System (ADS)

    González, J. O.; Shaji, S.; Avellaneda, D.; Castillo, G. A.; Das Roy, T. K.; Krishnan, B.

    2014-09-01

    Photovoltaic structures were prepared using AgSb(S x Se1- x )2 as absorber and CdS as window layer at various conditions via a hybrid technique of chemical bath deposition and thermal evaporation followed by heat treatments. Silver antimony sulfo selenide thin films [AgSb(S x Se1- x )2] were prepared by heating multilayers of sequentially deposited Sb2S3/Ag dipped in Na2SeSO3 solution, glass/Sb2S3/Ag/Se. For this, Sb2S3 thin films were deposited from a chemical bath containing SbCl3 and Na2S2O3. Then, Ag thin films were thermally evaporated on glass/Sb2S3, followed by selenization by dipping in an acidic solution of Na2SeSO3. The duration of dipping was varied as 3, 4 and 5 h. Two different heat treatments, one at 350 °C for 20 min in vacuum followed by a post-heat treatment at 325 °C for 2 h in Ar, and the other at 350 °C for 1 h in Ar, were applied to the multilayers of different configurations. X-ray diffraction results showed the formation of AgSb(S x Se1- x )2 thin films as the primary phase and AgSb(S,Se)2 and Sb2S3 as secondary phases. Morphology and elemental detection were done by scanning electron microscopy and energy dispersive X-ray analysis. X-ray photoelectron spectroscopic studies showed the depthwise composition of the films. Optical properties were determined by UV-vis-IR transmittance and reflection spectral analysis. AgSb(S x Se1- x )2 formed at different conditions was incorporated in PV structures glass/FTO/CdS/AgSb(S x Se1- x )2/C/Ag. Chemically deposited post-annealed CdS thin films of various thicknesses were used as window layer. J- V characteristics of the cells were measured under dark and AM1.5 illumination. Analysis of the J- V characteristics resulted in the best solar cell parameters of V oc = 520 mV, J sc = 9.70 mA cm-2, FF = 0.50 and η = 2.7 %.

  7. Could some coral reefs become sponge reefs as our climate changes?

    PubMed

    Bell, James J; Davy, Simon K; Jones, Timothy; Taylor, Michael W; Webster, Nicole S

    2013-09-01

    Coral reefs across the world have been seriously degraded and have a bleak future in response to predicted global warming and ocean acidification (OA). However, this is not the first time that biocalcifying organisms, including corals, have faced the threat of extinction. The end-Triassic mass extinction (200 million years ago) was the most severe biotic crisis experienced by modern marine invertebrates, which selected against biocalcifiers; this was followed by the proliferation of another invertebrate group, sponges. The duration of this sponge-dominated period far surpasses that of alternative stable-ecosystem or phase-shift states reported on modern day coral reefs and, as such, a shift to sponge-dominated reefs warrants serious consideration as one future trajectory of coral reefs. We hypothesise that some coral reefs of today may become sponge reefs in the future, as sponges and corals respond differently to changing ocean chemistry and environmental conditions. To support this hypothesis, we discuss: (i) the presence of sponge reefs in the geological record; (ii) reported shifts from coral- to sponge-dominated systems; and (iii) direct and indirect responses of the sponge holobiont and its constituent parts (host and symbionts) to changes in temperature and pH. Based on this evidence, we propose that sponges may be one group to benefit from projected climate change and ocean acidification scenarios, and that increased sponge abundance represents a possible future trajectory for some coral reefs, which would have important implications for overall reef functioning. PMID:23553821

  8. Sponge-associated bacteria: general overview and special aspects of bacteria associated with Halichondria panicea.

    PubMed

    Imhoff, J F; Stöhr, R

    2003-01-01

    Increasing evidence is accumulating that highlights the important role of bacteria in bacteria-sponge associations. It appears to be equally important to analyse the specific association of bacteria with sponges, to realise the biological function of biologically active substances produced by sponge-associated bacteria, and to consider the relationship between bacteria and sponges in the search for new pharmaceutical products. In this chapter the current knowledge on bacteria-sponge associations is briefly reviewed. Results are summarised that were obtained by three major methodological approaches: (1) classical microscope observations, (2) investigations attempting to characterise sponge-associated bacteria by describing pure culture isolates, and (3) the rapidly growing evidence from genetic analyses of sponge-associated bacteria. Special emphasis is given to the evidence of possible symbiotic interactions between bacteria and sponges and to the synthesis of natural products by bacteria isolated from or associated with marine sponges. Case studies including morphological and genetic studies together with results from pure culture studies have been performed with bacteria from the sponges Rhodopaloeides odorabile, Aplysina cavernicola, and Halichondria panicea. In addition, new results on bacteria associated with Halichondria panicea are also presented. PMID:15825639

  9. Culturable heterotrophic bacteria from the marine sponge Dendrilla nigra: isolation and phylogenetic diversity of actinobacteria

    NASA Astrophysics Data System (ADS)

    Selvin, Joseph; Gandhimathi, R.; Kiran, G. Seghal; Priya, S. Shanmugha; Ravji, T. Rajeetha; Hema, T. A.

    2009-09-01

    Culturable heterotrophic bacterial composition of marine sponge Dendrilla nigra was analysed using different enrichments. Five media compositions including without enrichment (control), enriched with sponge extract, with growth regulator (antibiotics), with autoinducers, and complete enrichment containing sponge extract, antibiotics, and autoinducers were developed. DNA hybridization assay was performed to explore host specific bacteria and ecotypes of culturable sponge-associated bacteria. Enrichment with selective inducers (AHLs and sponge extract) and regulators (antibiotics) considerably enhanced the cultivation potential of sponge-associated bacteria. It was found that Marinobacter (MSI032), Micromonospora (MSI033), Streptomyces (MSI051), and Pseudomonas (MSI057) were sponge-associated obligate symbionts. The present findings envisaged that “ Micromonospora-Saccharomonospora-Streptomyces” group was the major culturable actinobacteria in the marine sponge D. nigra. The DNA hybridization assay was a reliable method for the analysis of culturable bacterial community in marine sponges. Based on the culturable community structure, the sponge-associated bacteria can be grouped (ecotypes) as general symbionts, specific symbionts, habitat flora, and antagonists.

  10. Coral mucus fuels the sponge loop in warm- and cold-water coral reef ecosystems

    PubMed Central

    Rix, Laura; de Goeij, Jasper M.; Mueller, Christina E.; Struck, Ulrich; Middelburg, Jack J.; van Duyl, Fleur C.; Al-Horani, Fuad A.; Wild, Christian; Naumann, Malik S.; van Oevelen, Dick

    2016-01-01

    Shallow warm-water and deep-sea cold-water corals engineer the coral reef framework and fertilize reef communities by releasing coral mucus, a source of reef dissolved organic matter (DOM). By transforming DOM into particulate detritus, sponges play a key role in transferring the energy and nutrients in DOM to higher trophic levels on Caribbean reefs via the so-called sponge loop. Coral mucus may be a major DOM source for the sponge loop, but mucus uptake by sponges has not been demonstrated. Here we used laboratory stable isotope tracer experiments to show the transfer of coral mucus into the bulk tissue and phospholipid fatty acids of the warm-water sponge Mycale fistulifera and cold-water sponge Hymedesmia coriacea, demonstrating a direct trophic link between corals and reef sponges. Furthermore, 21–40% of the mucus carbon and 32–39% of the nitrogen assimilated by the sponges was subsequently released as detritus, confirming a sponge loop on Red Sea warm-water and north Atlantic cold-water coral reefs. The presence of a sponge loop in two vastly different reef environments suggests it is a ubiquitous feature of reef ecosystems contributing to the high biogeochemical cycling that may enable coral reefs to thrive in nutrient-limited (warm-water) and energy-limited (cold-water) environments. PMID:26740019

  11. Coral mucus fuels the sponge loop in warm- and cold-water coral reef ecosystems.

    PubMed

    Rix, Laura; de Goeij, Jasper M; Mueller, Christina E; Struck, Ulrich; Middelburg, Jack J; van Duyl, Fleur C; Al-Horani, Fuad A; Wild, Christian; Naumann, Malik S; van Oevelen, Dick

    2016-01-01

    Shallow warm-water and deep-sea cold-water corals engineer the coral reef framework and fertilize reef communities by releasing coral mucus, a source of reef dissolved organic matter (DOM). By transforming DOM into particulate detritus, sponges play a key role in transferring the energy and nutrients in DOM to higher trophic levels on Caribbean reefs via the so-called sponge loop. Coral mucus may be a major DOM source for the sponge loop, but mucus uptake by sponges has not been demonstrated. Here we used laboratory stable isotope tracer experiments to show the transfer of coral mucus into the bulk tissue and phospholipid fatty acids of the warm-water sponge Mycale fistulifera and cold-water sponge Hymedesmia coriacea, demonstrating a direct trophic link between corals and reef sponges. Furthermore, 21-40% of the mucus carbon and 32-39% of the nitrogen assimilated by the sponges was subsequently released as detritus, confirming a sponge loop on Red Sea warm-water and north Atlantic cold-water coral reefs. The presence of a sponge loop in two vastly different reef environments suggests it is a ubiquitous feature of reef ecosystems contributing to the high biogeochemical cycling that may enable coral reefs to thrive in nutrient-limited (warm-water) and energy-limited (cold-water) environments. PMID:26740019

  12. SCF promotes dental pulp progenitor migration, neovascularization, and collagen remodeling - potential applications as a homing factor in dental pulp regeneration.

    PubMed

    Pan, Shuang; Dangaria, Smit; Gopinathan, Gokul; Yan, Xiulin; Lu, Xuanyu; Kolokythas, Antonia; Niu, Yumei; Luan, Xianghong

    2013-10-01

    Stem cell factor (SCF) is a powerful chemokine that binds to the c-Kit receptor CD117 and has shown promise as a homing agent capable of progenitor cell recruitment. In the present study we have documented high levels of both SCF and its receptor c-Kit in differentiating dental pulp (DP) cells and in the sub-odontoblastic layer of Höhl. In vitro studies using human DP progenitors revealed a significant increase in cell proliferation after100 nM SCF application, explained by a 2-fold upregulation in cyclin D3 and FGF2 cell cycle regulators, and a 7-fold increase in CDK4 expression. DP cell migration in the presence of SCF was up-regulated 2.7-fold after a 24 h culture period, and this effect was accompanied by cytoskeletal rearrangement, a 1.5-fold increase in polymeric F-actin over G-actin, and a 1.8-fold increase in RhoA expression. Explaining the signaling effect of SCF on DP migration, PI3K/Akt and MEK/ERK pathway inhibitors were demonstrated to significantly reduce DP cell migration, while SCF alone doubled the number of migrated cells. ERK and AKT phosphorylation were dramatically upregulated already 3-5 min after SCF addition to the culture medium and declined thereafter, classifying SCF as a fast acting chemokine. When applied as an agent to promote tissue regeneration in subcutaneously implanted collagen sponges, SCF resulted in a 7-fold increase in the cell number in the implanted tissue construct, a more than 9-fold increase in capillaries, as well as collagen sponge remodeling and collagen fiber neogenesis. Together, these studies demonstrate the suitability of SCF as a potent aid in the regeneration of dental pulp and other mesenchymal tissues, capable of inducing cell homing, angiogenesis, and tissue remodeling. PMID:23703692

  13. Shifts in microbial and chemical patterns within the marine sponge Aplysina aerophoba during a disease outbreak.

    PubMed

    Webster, Nicole S; Xavier, Joana R; Freckelton, Marnie; Motti, Cherie A; Cobb, Rose

    2008-12-01

    The microbial community composition in affected and unaffected portions of diseased sponges and healthy control sponges of Aplysina aerophoba was assessed to ascertain the role of microbes in the disease process. Sponge secondary metabolites were also examined to assess chemical shifts in response to infection. The microbial profile and aplysinimine levels in unaffected tissue near the lesions closely reflected those of healthy sponge tissue, indicating a highly localized disease process. DGGE detected multiple sequences that were exclusively present in diseased sponges. Most notably, a Deltaproteobacteria sequence with high homology to a coral black band disease strain was detected in all sponge lesions and was absent from all healthy and unaffected regions of diseased sponges. Other potential pathogens identified by DGGE include an environmental Cytophaga strain and a novel Epsilonproteobacteria strain with no known close relatives. The disease process also caused a major shift in prokaryote community structure at a very high taxonomic level. Using 16S rRNA gene sequence analysis, only the diseased sponges were found to contain sequences belonging to the Epsilonproteobacteria and Firmicutes, and there was a much greater number of Bacteroidetes sequences within the diseased sponges. In contrast, only the healthy sponges contained sequences corresponding to the cyanobacteria and 'OP1' candidate division, and the healthy sponges were dominated by Chloroflexi and Gammaproteobacteria sequences. Overall bacterial diversity was found to be considerably higher in diseased sponges than in healthy sponges. These results provide a platform for future cultivation-based experiments to isolate the putative pathogens from A. aerophoba and perform re-infection trials to define the disease aetiology. PMID:18783385

  14. Trade-offs in defensive metabolite production but not ecological function in healthy and diseased sponges.

    PubMed

    Gochfeld, Deborah J; Kamel, Haidy N; Olson, Julie B; Thacker, Robert W

    2012-05-01

    Diseases of marine organisms, and sponges in particular, are increasingly reported worldwide. Prior research indicates that the survival of sponges on reefs is due largely to their production of biologically active secondary metabolites that provide protection from a diversity of stressors. Aplysina Red Band Syndrome (ARBS) is an emerging disease affecting Caribbean rope sponges (Aplysina spp.), but it is not known whether secondary metabolites play a role in disease susceptibility and resistance. To investigate whether differences in secondary metabolites may explain variability in susceptibility to ARBS in Aplysina cauliformis, we used high performance liquid chromatography (HPLC) to generate chemical profiles from healthy tissue in both healthy and diseased sponges, and quantified peak areas for 15 metabolites. Analyses of healthy and diseased sponges revealed qualitative and quantitative differences in their chemical profiles. Aplysamine-1 and fistularin-3 were produced in significantly higher concentrations by healthy sponges, whereas aerothionin and 11-oxoaerothionin were found only in diseased sponges. At natural concentrations, extracts from both healthy and diseased sponges deterred feeding by an omnivorous reef fish. Fistularin-3 deterred feeding at concentrations found in healthy sponges, but not at concentrations found in diseased sponges. Aerothionin deterred feeding at concentrations found in diseased sponges, and may at least partially replace the loss of fistularin-3 as a feeding deterrent compound following pathogenesis, suggesting a trade-off in the production of feeding deterrent compounds. Extracts from healthy and diseased sponges inhibited bacterial growth, and both aplysamine-1 and fistularin-3 displayed selective antibacterial activity. Despite differences in secondary metabolite production between healthy and diseased sponges, the stress associated with ARBS does not appear to compromise the ability of A. cauliformis to maintain defenses

  15. A Au nanoparticle-incorporated sponge as a versatile transmission surface-enhanced Raman scattering substrate.

    PubMed

    Shin, Kayeong; Chung, Hoeil

    2015-08-01

    We report a sponge-based transmission surface-enhanced Raman scattering (TSERS) substrate that combines the bulk sampling capabilities of a transmission measurement to improve the quantitative representation of sample concentration with several sponge properties useful for analysis such as fast sample uptake, easy sample enrichment, and a stable polymeric structure. Among nine commercially available sponges made of different materials, a melamine sponge was ultimately selected for this study because it provided the fastest sample uptake and a low background Raman signal. Simultaneously, the amino groups and three-nitrogen hybrid rings in its structure could easily hold Au nanoparticles (AuNPs) inside the sponge. AuNP-incorporated sponges (AuNP sponges) were prepared by simply soaking a melamine sponge in a AuNP solution; these sponges were initially used to measure 4-nitrobenzenethiol (4-NBT) samples with different concentrations in order to evaluate their ability as TSERS substrates. The intensities of the 4-NBT peaks clearly varied according to changes in the concentration, and the relative standard deviation (RSD) of the peak intensity estimated by the measurements of five independently prepared AuNP sponges was 10.0%. Sample enrichment was easily completed by repeated suctioning of the sample into the AuNP sponges followed by depletion of the solvent, so three-time enrichment doubled the intensity. Furthermore, paraquat samples were prepared in diverse matrices (de-ionized water, tap water, river water, and orange juice) and measured using the AuNP sponges. The paraquat peaks were clearly observed from these samples and their peak intensities became smaller with the increased compositional complexity of the matrices. Our overall results demonstrate that the TSERS sponge substrates are easy to prepare and practically versatile for SERS analysis of diverse samples. PMID:26079472

  16. These Squatters Are Not Innocent: The Evidence of Parasitism in Sponge-Inhabiting Shrimps

    PubMed Central

    Ďuriš, Zdeněk; Horká, Ivona; Juračka, Petr Jan; Petrusek, Adam; Sandford, Floyd

    2011-01-01

    Marine sponges are frequently inhabited by a wide range of associated invertebrates, including caridean shrimps. Symbiotic shrimps are often considered to be commensals; however, in most cases, the relationship with sponge hosts remains unclear. Here we demonstrate that sponge-inhabiting shrimps are often parasites adapted to consumption of sponge tissues. First, we provide detailed examination of morphology and stomach contents of Typton carneus (Decapoda: Palaemonidae: Pontoniinae), a West Atlantic tropical shrimp living in fire sponges of the genus Tedania. Remarkable shear-like claws of T. carneus show evidence of intensive shearing, likely the result of crushing siliceous sponge spicules. Examination of stomach contents revealed that the host sponge tissue is a major source of food for T. carneus. A parasitic mode of life is also reflected in adaptations of mouth appendages, in the reproduction strategy, and in apparent sequestration of host pigments by shrimp. Consistent results were obtained also for congeneric species T. distinctus (Western Atlantic) and T. spongicola (Mediterranean). The distribution of shrimps among sponge hosts (mostly solitary individuals or heterosexual pairs) suggests that Typton shrimps actively prevent colonisation of their sponge by additional conspecifics, thus protecting their resource and reducing the damage to the hosts. We also demonstrate feeding on host tissues by sponge-associated shrimps of the genera Onycocaris, Periclimenaeus, and Thaumastocaris (Pontoniinae) and Synalpheus (Alpheidae). The parasitic mode of life appears to be widely distributed among sponge-inhabiting shrimps. However, it is possible that under some circumstances, the shrimps provide a service to the host sponge by preventing a penetration by potentially more damaging associated animals. The overall nature of interspecific shrimp-sponge relationships thus warrants further investigation. PMID:21814564

  17. Absorbent product to absorb fluids. [for collection of human wastes

    NASA Technical Reports Server (NTRS)

    Dawn, F. S.; Correale, J. V. (Inventor)

    1982-01-01

    A multi-layer absorbent product for use in contact with the skin to absorb fluids is discussed. The product utilizes a water pervious facing layer for contacting the skin, overlayed by a first fibrous wicking layer, the wicking layer preferably being of the one-way variety in which fluid or liquid is moved away from the facing layer. The product further includes a first container section defined by inner and outer layer of a water pervious wicking material between which is disposed a first absorbent mass. A second container section defined by inner and outer layers between which is disposed a second absorbent mass and a liquid impermeable/gas permeable layer. Spacesuit applications are discussed.

  18. Nanolayered Features of Collagen-like Peptides

    NASA Technical Reports Server (NTRS)

    Valluzzi, Regina; Bini, Elisabetta; Haas, Terry; Cebe, Peggy; Kaplan, David L.

    2003-01-01

    We have been investigating collagen-like model oligopeptides as molecular bases for complex ordered biomimetic materials. The collagen-like molecules incorporate aspects of native collagen sequence and secondary structure. Designed modifications to native primary and secondary structure have been incorporated to control the nanostructure and microstructure of the collagen-like materials produced. We find that the collagen-like molecules form a number of lyotropic rod liquid crystalline phases, which because of their strong temperature dependence in the liquid state can also be viewed as solvent intercalated thermotropic liquid crystals. The liquid crystalline phases formed by the molecules can be captured in the solid state by drying off solvent, resulting in solid nanopatterned (chemically and physically) thermally stable (to greater than 100 C) materials. Designed sequences which stabilize smectic phases have allowed a variety of nanoscale multilayered biopolymeric materials to be developed. Preliminary investigations suggest that chemical patterns running perpendicular to the smectic layer plane can be functionalized and used to localize a variety of organic, inorganic, and organometallic moieties in very simple multilayered nanocomposites. The phase behavior of collagen-like oligopeptide materials is described, emphasizing the correlation between mesophase, molecular orientation, and chemical patterning at the microscale and nanoscale. In many cases, the textures observed for smectic and hexatic phase collagens are remarkably similar to the complex (and not fully understood) helicoids observed in biological collagen-based tissues. Comparisons between biological morphologies and collagen model liquid crystalline (and solidified materials) textures may help us understand the molecular features which impart order and function to the extracellular matrix and to collagen-based mineralized tissues. Initial studies have utilized synthetic collagen-like peptides while

  19. Metabolic profiles of prokaryotic and eukaryotic communities in deep-sea sponge Lamellomorpha sp. indicated by metagenomics

    NASA Astrophysics Data System (ADS)

    Li, Zhi-Yong; Wang, Yue-Zhu; He, Li-Ming; Zheng, Hua-Jun

    2014-01-01

    The whole metabolism of a sponge holobiont and the respective contributions of prokaryotic and eukaryotic symbionts and their associations with the sponge host remain largely unclear. Meanwhile, compared with shallow water sponges, deep-sea sponges are rarely understood. Here we report the metagenomic exploration of deep-sea sponge Lamellomorpha sp. at the whole community level. Metagenomic data showed phylogenetically diverse prokaryotes and eukaryotes in Lamellomorpha sp.. MEGAN and gene enrichment analyses indicated different metabolic potentials of prokaryotic symbionts from eukaryotic symbionts, especially in nitrogen and carbon metabolisms, and their molecular interactions with the sponge host. These results supported the hypothesis that prokaryotic and eukaryotic symbionts have different ecological roles and relationships with sponge host. Moreover, vigorous denitrification, and CO2 fixation by chemoautotrophic prokaryotes were suggested for this deep-sea sponge. The study provided novel insights into the respective potentials of prokaryotic and eukaryotic symbionts and their associations with deep-sea sponge Lamellomorpha sp..

  20. Polyketide genes in the marine sponge Plakortis simplex: a new group of mono-modular type I polyketide synthases from sponge symbionts

    PubMed Central

    Della Sala, Gerardo; Hochmuth, Thomas; Costantino, Valeria; Teta, Roberta; Gerwick, William; Gerwick, Lena; Piel, Jörn; Mangoni, Alfonso

    2013-01-01

    Summary Sponge symbionts are a largely unexplored source of new and unusual metabolic pathways. Insights into the distribution and function of metabolic genes of sponge symbionts are crucial to dissect and exploit their biotechnological potential. Screening of the metagenome of the marine sponge Plakortis simplex led to the discovery of the swf family, a new group of mono-modular type I polyketide synthase/fatty acid synthase (PKS/FAS) specifically associated with sponge symbionts. Two different examples of the swf cluster were present in the metagenome of P. simplex. A third example of the cluster is present in the previously sequenced genome of a poribacterium from the sponge Aplysina aerophoba but was formerly considered orthologous to the wcb/rkp cluster. The swf cluster was also found in six additional species of sponges. Therefore, the swf cluster represents the second group of mono-modular PKS, after the supA family, to be widespread in marine sponges. The putative swf operon consists of swfA (type I PKS/FAS), swfB (reductase and sulphotransferase domains) and swfC (radical S-adenosylmethionine, or radical SAM). Activation of the acyl carrier protein (ACP) domain of the SwfA protein to its holo-form by co-expression with Svp is the first functional proof of swf type genes in marine sponges. However, the precise biosynthetic role of the swf clusters remains unknown. PMID:24249289

  1. Polyketide genes in the marine sponge Plakortis simplex: a new group of mono-modular type I polyketide synthases from sponge symbionts.

    PubMed

    Della Sala, Gerardo; Hochmuth, Thomas; Costantino, Valeria; Teta, Roberta; Gerwick, William; Gerwick, Lena; Piel, Jörn; Mangoni, Alfonso

    2013-12-01

    Sponge symbionts are a largely unexplored source of new and unusual metabolic pathways. Insights into the distribution and function of metabolic genes of sponge symbionts are crucial to dissect and exploit their biotechnological potential. Screening of the metagenome of the marine sponge Plakortis simplex led to the discovery of the swf family, a new group of mono-modular type I polyketide synthase/fatty acid synthase (PKS/FAS) specifically associated with sponge symbionts. Two different examples of the swf cluster were present in the metagenome of P. simplex. A third example of the cluster is present in the previously sequenced genome of a poribacterium from the sponge Aplysina aerophoba but was formerly considered orthologous to the wcb/rkp cluster. The swf cluster was also found in six additional species of sponges. Therefore, the swf cluster represents the second group of mono-modular PKS, after the supA family, to be widespread in marine sponges. The putative swf operon consists of swfA (type I PKS/FAS), swfB (reductase and sulphotransferase domains) and swfC (radical S-adenosylmethionine, or radical SAM). Activation of the acyl carrier protein (ACP) domain of the SwfA protein to its holo-form by co-expression with Svp is the first functional proof of swf type genes in marine sponges. However, the precise biosynthetic role of the swf clusters remains unknown. PMID:24249289

  2. Protection of biomass from snail overgrazing in a trickling filter using sponge media as a biomass carrier: down-flow hanging sponge system.

    PubMed

    Onodera, Takashi; Syutsubo, Kazuaki; Yoochatchaval, Wilasinee; Sumino, Haruhiko; Mizuochi, Motoyuki; Harada, Hideki

    2015-01-01

    This study investigated down-flow hanging sponge (DHS) technology as a promising trickling filter (TF) using sponge media as a biomass carrier with an emphasis on protection of the biomass against macrofauna overgrazing. A pilot-scale DHS reactor fed with low-strength municipal sewage was operated under ambient temperature conditions for 1 year at a sewage treatment plant in Bangkok, Thailand. The results showed that snails (macrofauna) were present on the surface of the sponge media, but could not enter into it, because the sponge media with smaller pores physically protected the biomass from the snails. As a result, the sponge media maintained a dense biomass, with an average value of 22.3 gVSS/L sponge (58.1 gTSS/L sponge) on day 370. The snails could graze biomass on the surface of the sponge media. The DHS reactor process performance was also successful. The DHS reactor requires neither chemical treatments nor specific operations such as flooding for snail control. Overall, the results of this study indicate that the DHS reactor is able to protect biomass from snail overgrazing. PMID:25746642

  3. Collagen structure: new tricks from a very old dog.

    PubMed

    Bella, Jordi

    2016-04-15

    The main features of the triple helical structure of collagen were deduced in the mid-1950s from fibre X-ray diffraction of tendons. Yet, the resulting models only could offer an average description of the molecular conformation. A critical advance came about 20 years later with the chemical synthesis of sufficiently long and homogeneous peptides with collagen-like sequences. The availability of these collagen model peptides resulted in a large number of biochemical, crystallographic and NMR studies that have revolutionized our understanding of collagen structure. High-resolution crystal structures from collagen model peptides have provided a wealth of data on collagen conformational variability, interaction with water, collagen stability or the effects of interruptions. Furthermore, a large increase in the number of structures of collagen model peptides in complex with domains from receptors or collagen-binding proteins has shed light on the mechanisms of collagen recognition. In recent years, collagen biochemistry has escaped the boundaries of natural collagen sequences. Detailed knowledge of collagen structure has opened the field for protein engineers who have used chemical biology approaches to produce hyperstable collagens with unnatural residues, rationally designed collagen heterotrimers, self-assembling collagen peptides, etc. This review summarizes our current understanding of the structure of the collagen triple helical domain (COL×3) and gives an overview of some of the new developments in collagen molecular engineering aiming to produce novel collagen-based materials with superior properties. PMID:27060106

  4. Laser welding and collagen crosslinks

    SciTech Connect

    Reiser, K.M.; Last, J.A.; Small, W. IV; Maitland, D.J.; Heredia, N.J.; Da Silva, L.B.; Matthews, D.L.

    1997-02-20

    Strength and stability of laser-welded tissue may be influenced, in part, by effects of laser exposure on collagen crosslinking. We therefore studied effects of diode laser exposure (805 nm, 1-8 watts, 30 seconds) + indocyanine green dye (ICG) on calf tail tendon collagen crosslinks. Effect of ICG dye alone on crosslink content prior to laser exposure was investigated; unexpectedly, we found that ICG-treated tissue had significantly increased DHLNL and OHP, but not HLNL. Laser exposure after ICG application reduced elevated DHLNL and OHP crosslink content down to their native levels. The monohydroxylated crosslink HLNL was inversely correlated with laser output (p<0.01 by linear regression analysis). DHLNL content was highly correlated with content of its maturational product, OHP, suggesting that precursor-product relations are maintained. We conclude that: (1)ICG alone induces DHLNL and OHP crosslink formation; (2)subsequent laser exposure reduces the ICG-induced crosslinks down to native levels; (3)excessive diode laser exposure destroys normally occurring HLNL crosslinks.

  5. Genetics Home Reference: collagen VI-related myopathy

    MedlinePlus

    ... Genetics Home Health Conditions collagen VI-related myopathy collagen VI-related myopathy Enable Javascript to view the ... boxes. Download PDF Open All Close All Description Collagen VI-related myopathy is a group of disorders ...

  6. Cartilage collagen analysis in the chondrodystrophies.

    PubMed

    Horton, W A; Chou, J W; Machado, M A

    1985-09-01

    A simple and reproducible method for analyzing small samples of cartilage collagens was developed. Following extraction with guanidine HCl, the cartilage specimens were digested directly with CNBr and the resultant peptides separated by gel-permeation high-performance liquid chromatography. Resting cartilage collagen CNBr peptide maps differed from normal in two inherited chondrodystrophies, achondrogenesis II and spondyloepiphyseal dysplasia congenita. PMID:4053564

  7. Pseudomembranous collagenous colitis with superimposed drug damage.

    PubMed

    Villanacci, Vincenzo; Cristina, Silvia; Muscarà, Maurizio; Saettone, Silvia; Broglia, Laura; Antonelli, Elisabetta; Salemme, Marianna; Occhipinti, Pietro; Bassotti, Gabrio

    2013-11-01

    Pseudomembranous collagenous colitis is a rare pathological condition, not related to infectious agents, and characterized by thickening of the subepithelial collagen and formation of pseudomembranes. We report one such case, which responded to budesonide treatment after failures of previous approaches given, being unaware of the correct diagnosis. PMID:24080283

  8. A novel benign solution for collagen processing

    NASA Astrophysics Data System (ADS)

    Arnoult, Olivier

    Collagen is the main protein constituting the extracellular matrix (ECM) of tissues in the body (skin, cartilage, blood vessels...). It exists many types of collagen, this work studies only fibrillar collagen (e.g. collagen type I contained in the skin) that exhibits a triple helical structure composed of 3 alpha-helical collagen chains. This particular and defined hierarchical structure is essential to the biological and mechanical properties of the collagen. Processing collagen into scaffolds to mimic the ECM is crucial for successful tissue engineering. Recently collagen was processed into fibrous and porous scaffold using electrospinning process. However the solvent (HFIP) used for electrospinning is extremely toxic for the user and expensive. This work shows that HFIP can be replaced by a benign mixture composed of water, salt and alcohol. Yet only three alcohols (methanol, ethanol and iso-propanol) enable the dissolution of large quantity of collagen in the benign mixture, with a wide range of alcohol to buffer ratio, and conserve the collagen hierarchical structure at least as well as the HFIP. Collagen can be electrospun from the benign mixture into sub-micron fibers with concentrations as low as 6 wt-% for a wide range of alcohol to buffer ratio, with at least 10wt-% of salt, and any of the three alcohols. Specific conditions yield nano size fibers. After processing from HFIP or a benign mixture, collagen is water soluble and needs to be chemically crosslink for tissue engineering application. Post-crosslinking with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) results in the loss of the scaffold fibrous aspect and porosity, hence it is useless for tissue engineering. Such issue could be prevented by incorporating the crosslinker into the mixture prior to electrospinning. When EDC is used alone, collagen forms a gel in the mixture within minutes, preventing electrospinning. The addition of N-hydroxysuccinimide (NHS) in excess to EDC

  9. Photoinduced effect of hypericin on collagen and tissues with high collagen content

    NASA Astrophysics Data System (ADS)

    Yova, Dido M.; Theodossiou, Theodossis; Hovhannisyan, Vladimir A.

    1999-01-01

    The photoinduced effects of hypericin, a polycyclic quinone, on collagen has been investigated. It was found that after laser irradiation at both 532 nm and 337 nm, the spectral form of triple helix structure collagen fluorescence, changed to a spectral profile bearing resemblance to that of its polypeptide single chain counterpart, gelatin, or heated collagen. The effect of Chlorin e6 on collagen was also investigated and proved to be dissimilar to that of hypericin and not indicative of profound structural alterations. Second Harmonic Generation (SHG) of 1064 nm- nanosecond laser radiation in collagen was studied. While it was very efficient for pure collagen, the signal intensity was found to diminish by at least an order of magnitude after hypericin photosensitization or heating. The above noted fluorescence spectra form alteration was also observed in a smaller scale in collagen rich chicken tissue (tendon). Non sensitized chicken tendon tissue exhibited very efficient SHG, unlike skin and artery samples.

  10. Graphene/polyaniline composite sponge of three-dimensional porous network structure as supercapacitor electrode

    NASA Astrophysics Data System (ADS)

    Jiu-Xing, Jiang; Xu-Zhi, Zhang; Zhen-Hua, Wang; Jian-Jun, Xu

    2016-04-01

    As a supercapacitor electrode, the graphene/polyaniline (PANI) composite sponge with a three-dimensional (3D) porous network structure is synthesized by a simple three-step method. The three steps include an in situ polymerization, freeze-drying and reduction by hydrazine vapor. The prepared sponge has a large specific surface area and porous network structure, so it is in favor of spreading the electrolyte ion and increasing the charge transfer efficiency of the system. The process of preparation is simple, easy to operate and low cost. The composite sponge shows better electrochemical performance than the pure individual graphene sponge while PANI cannot keep the shape of a sponge. Such a composite sponge exhibits specific capacitances of 487 F·g‑1 at 2 mV/s compared to pristine PANI of 397 F·g‑1. Project supported by the Natural Science Foundation from Harbin University of Science and Technology and Harbin Institute of Technology.

  11. Breathing Demulsification: A Three-Dimensional (3D) Free-Standing Superhydrophilic Sponge.

    PubMed

    Xu, Liangxin; Chen, Yuning; Liu, Na; Zhang, Weifeng; Yang, Yang; Cao, Yingze; Lin, Xin; Wei, Yen; Feng, Lin

    2015-10-14

    A novel three-dimensional (3D) free-standing superhydrophilic sponge for industrial wastewater treatment was formed by combining chitosan and linear polyacrylamide (PAM). When the chitosan-PAM sponge is immersed into an oil-in-water emulsion, the milky white emulsion containing surfactant turns clear and clarified. Demulsification efficiency, capacity, and recyclability of this positively charged chitosan-PAM sponge to oil-in-water emulsions stabilized by different types of surfactants including anionic, nonionic, and cationic surfactants, has been investigated for further practical evaluation. A "breathing demulsification" mechanism is presented to explain this attractive demulsified process. The effective contact area between emulsion and sponge is increased by the microcomposite and nanocomposite hierarchical structure of the chitosan-PAM free-standing sponge. Then, interfacial interactions, size effect, and strain act as the driving force for the demulsification of the emulsified droplets at the surface of the sponge. PMID:26389668

  12. Proline puckering parameters for collagen structure simulations

    SciTech Connect

    Wu, Di

    2015-03-15

    Collagen is made of triple helices rich in proline residues, and hence is influenced by the conformational motions of prolines. Because the backbone motions of prolines are restricted by the helical structures, the only side chain motion—proline puckering—becomes an influential factor that may affect the stability of collagen structures. In molecular simulations, a proper proline puckering population is desired so to yield valid results of the collagen properties. Here we design the proline puckering parameters in order to yield suitable proline puckering populations as demonstrated in the experimental results. We test these parameters in collagen and the proline dipeptide simulations. Compared with the results of the PDB and the quantum calculations, we propose the proline puckering parameters for the selected collagen model simulations.

  13. Bioengineered collagens: emerging directions for biomedical materials.

    PubMed

    Ramshaw, John A M; Werkmeister, Jerome A; Dumsday, Geoff J

    2014-01-01

    Mammalian collagen has been widely used as a biomedical material. Nevertheless, there are still concerns about the variability between preparations, particularly with the possibility that the products may transmit animal-based diseases. Many groups have examined the possible application of bioengineered mammalian collagens. However, translating laboratory studies into large-scale manufacturing has often proved difficult, although certain yeast and plant systems seem effective. Production of full-length mammalian collagens, with the required secondary modification to give proline hydroxylation, has proved difficult in E. coli. However, recently, a new group of collagens, which have the characteristic triple helical structure of collagen, has been identified in bacteria. These proteins are stable without the need for hydroxyproline and are able to be produced and purified from E. coli in high yield. Initial studies indicate that they would be suitable for biomedical applications. PMID:24717980

  14. Countercurrent flow absorber and desorber

    DOEpatents

    Wilkinson, William H.

    1984-01-01

    Countercurrent flow absorber and desorber devices are provided for use in absorption cycle refrigeration systems and thermal boosting systems. The devices have increased residence time and surface area resulting in improved heat and mass transfer characteristics. The apparatuses may be incorporated into open cycle thermal boosting systems in which steam serves both as the refrigerant vapor which is supplied to the absorber section and as the supply of heat to drive the desorber section of the system.

  15. Hyperuniformity of critical absorbing states.

    PubMed

    Hexner, Daniel; Levine, Dov

    2015-03-20

    The properties of the absorbing states of nonequilibrium models belonging to the conserved directed percolation universality class are studied. We find that, at the critical point, the absorbing states are hyperuniform, exhibiting anomalously small density fluctuations. The exponent characterizing the fluctuations is measured numerically, a scaling relation to other known exponents is suggested, and a new correlation length relating to this ordering is proposed. These results may have relevance to photonic band-gap materials. PMID:25839254

  16. Hyperuniformity of Critical Absorbing States

    NASA Astrophysics Data System (ADS)

    Hexner, Daniel; Levine, Dov

    2015-03-01

    The properties of the absorbing states of nonequilibrium models belonging to the conserved directed percolation universality class are studied. We find that, at the critical point, the absorbing states are hyperuniform, exhibiting anomalously small density fluctuations. The exponent characterizing the fluctuations is measured numerically, a scaling relation to other known exponents is suggested, and a new correlation length relating to this ordering is proposed. These results may have relevance to photonic band-gap materials.

  17. Packed Alumina Absorbs Hypergolic Vapors

    NASA Technical Reports Server (NTRS)

    Thomas, J. J.; Mauro, D. M.

    1984-01-01

    Beds of activated alumina effective as filters to remove hypergolic vapors from gas streams. Beds absorb such substances as nitrogen oxides and hydrazines and may also absorb acetylene, ethylene, hydrogen sulfide, benzene, butadiene, butene, styrene, toluene, and xoylene. Bed has no moving parts such as pumps, blowers and mixers. Reliable and energy-conservative. Bed readily adapted to any size from small portable units for use where little vapor release is expected to large stationary units for extensive transfer operations.

  18. Countercurrent flow absorber and desorber

    DOEpatents

    Wilkinson, W.H.

    1984-10-16

    Countercurrent flow absorber and desorber devices are provided for use in absorption cycle refrigeration systems and thermal boosting systems. The devices have increased residence time and surface area resulting in improved heat and mass transfer characteristics. The apparatuses may be incorporated into open cycle thermal boosting systems in which steam serves both as the refrigerant vapor which is supplied to the absorber section and as the supply of heat to drive the desorber section of the system. 9 figs.

  19. New Antimicrobial Bromotyrosine Analogues from the Sponge Pseudoceratina purpurea and Its Predator Tylodina corticalis

    PubMed Central

    Gotsbacher, Michael P.; Karuso, Peter

    2015-01-01

    Bioassay-guided fractionation of extracts from temperate Australian collections of the marine sponge Pseudoceratina purpurea resulted in the isolation and characterisation of two new and six known bromotyrosine-derived alkaloids with antibiotic activity. Surprisingly, a single specimen of the mollusc Tylodina corticalis, which was collected while feeding on P. purpurea, contained only a few of the compounds found in the sponge suggesting selective accumulation and chemical modification of sponge metabolites. PMID:25786066

  20. Microbial Diversity and Putative Diazotrophy in High- and Low-Microbial-Abundance Mediterranean Sponges

    PubMed Central

    Coma, Rafel; Riemann, Lasse

    2015-01-01

    Microbial communities associated with marine sponges carry out nutrient transformations essential for benthic-pelagic coupling; however, knowledge about their composition and function is still sparse. We evaluated the richness and diversity of prokaryotic assemblages associated with three high-microbial-abundance (HMA) and three low-microbial-abundance (LMA) sympatric Mediterranean sponges to address their stability and uniqueness. Moreover, to examine functionality and because an imbalance between nitrogen ingestion and excretion has been observed for some of these species, we sequenced nitrogenase genes (nifH) and measured N2 fixation. The prokaryotic communities in the two sponge types did not differ in terms of richness, but the highest diversity was found in HMA sponges. Moreover, the discrete composition of the communities in the two sponge types relative to that in the surrounding seawater indicated that horizontal transmission and vertical transmission affect the microbiomes associated with the two sponge categories. nifH genes were found in all LMA species and sporadically in one HMA species, and about half of the nifH gene sequences were common between the different sponge species and were also found in the surrounding water, suggesting horizontal transmission. 15N2-enriched incubations showed that N2 fixation was measurable in the water but was not associated with the sponges. Also, the analysis of the isotopic ratio of 15N to 14N in sponge tissue indicated that N2 fixation is not an important source of nitrogen in these Mediterranean sponges. Overall, our results suggest that compositional and functional features differ between the prokaryotic communities associated with HMA and LMA sponges, which may affect sponge ecology. PMID:26070678

  1. Microbial Diversity and Putative Diazotrophy in High- and Low-Microbial-Abundance Mediterranean Sponges.

    PubMed

    Ribes, Marta; Dziallas, Claudia; Coma, Rafel; Riemann, Lasse

    2015-09-01

    Microbial communities associated with marine sponges carry out nutrient transformations essential for benthic-pelagic coupling; however, knowledge about their composition and function is still sparse. We evaluated the richness and diversity of prokaryotic assemblages associated with three high-microbial-abundance (HMA) and three low-microbial-abundance (LMA) sympatric Mediterranean sponges to address their stability and uniqueness. Moreover, to examine functionality and because an imbalance between nitrogen ingestion and excretion has been observed for some of these species, we sequenced nitrogenase genes (nifH) and measured N2 fixation. The prokaryotic communities in the two sponge types did not differ in terms of richness, but the highest diversity was found in HMA sponges. Moreover, the discrete composition of the communities in the two sponge types relative to that in the surrounding seawater indicated that horizontal transmission and vertical transmission affect the microbiomes associated with the two sponge categories. nifH genes were found in all LMA species and sporadically in one HMA species, and about half of the nifH gene sequences were common between the different sponge species and were also found in the surrounding water, suggesting horizontal transmission. (15)N2-enriched incubations showed that N2 fixation was measurable in the water but was not associated with the sponges. Also, the analysis of the isotopic ratio of (15)N to (14)N in sponge tissue indicated that N2 fixation is not an important source of nitrogen in these Mediterranean sponges. Overall, our results suggest that compositional and functional features differ between the prokaryotic communities associated with HMA and LMA sponges, which may affect sponge ecology. PMID:26070678

  2. NOAA to develop strategy to protect coral and sponge habitat

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    The U.S. National Marine Fisheries Service (NMFS) will develop a strategy to address research, conservation, and management issues regarding deep-ocean coral and sponge habitat, the agency indicated in an 11 July Federal Register notice. The Service, which is a unit of the National Oceanic and Atmospheric Administration, indicated that this strategy "eventually may result in rulemaking for some fisheries" but that "emergency rulemaking is not warranted."The NMFS announcement is in response to a 24 March 2004 petition to the Commerce Department filed by Oceana, a non-governmental organization. That petition urged the department through NMFS to "initiate immediate rulemaking" to protect coral and sponge habitats in the U.S. exclusive economic zone through mapping, monitoring, research, and enforcement measures.

  3. NOAA to develop strategy to protect coral and sponge habitat

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    The U.S. National Marine Fisheries Service (NMFS) will develop a strategy to address research, conservation, and management issues regarding deep-ocean coral and sponge habitat, the agency indicated in an 11 July Federal Register notice. The Service, which is a unit of the National Oceanic and Atmospheric Administration, indicated that this strategy “eventually may result in rulemaking for some fisheries” but that “emergency rulemaking is not warranted.”The NMFS announcement is in response to a 24 March 2004 petition to the Commerce Department filed by Oceana, a non-governmental organization. That petition urged the department through NMFS to “initiate immediate rulemaking” to protect coral and sponge habitats in the U.S. exclusive economic zone through mapping, monitoring, research, and enforcement measures.

  4. Antifouling activities of marine bacteria associated with sponge ( Sigmadocia sp.)

    NASA Astrophysics Data System (ADS)

    Satheesh, S.; Soniamby, A. R.; Sunjaiy Shankar, C. V.; Mary Josephine Punitha, S.

    2012-09-01

    The present study aimed at assessing the antifouling activity of bacteria associated with marine sponges. A total of eight bacterial strains were isolated from the surface of sponge Sigmadocia sp., of them, SS02, SS05 and SS06 showed inhibitory activity against biofilm-forming bacteria. The extracts of these 3 strains considerably affected the extracellular polymeric substance producing ability and adhesion of biofilm-forming bacterial strains. In addition to disc diffusion assay, microalgal settlement assay was carried out with the extracts mixed with polyurethane wood polish and coated onto stainless steel coupons. The extract of strain SS05 showed strong microalgal settlement inhibitory activity. Strain SS05 was identified as Bacillus cereus based on its 16S rRNA gene. Metabolites of the bacterial strains associated with marine invertebrates promise to be developed into environment-friendly antifouling agents.

  5. Retained Sponge: A Rare Complication in Acetabular Osteosinthesis

    PubMed Central

    Chana-Rodríguez, Francisco; Mañanes, Rubén Pérez; Rojo-Manaute, José; Moran-Blanco, Luz María; Vaquero-Martín, Javier

    2015-01-01

    Retained sponges after a surgical treatment of polytrauma may cause a broad spectrum of clinical symptoms and present a difficult diagnostic problem. We report a case of retained surgical sponge in a 35-year-old man transferred from another hospital, that sustained a open acetabular fracture. The fracture was reduced through a limited ilio-inguinal approach. After 4 days, he presented massive wound dehiscence of the surgical approach. An abdominal CT scan showed, lying adjacent to the outer aspect of the left iliac crest, a mass of 10 cm, identified as probable foreign body. The possibility of this rare complication should be in the differential diagnosis of any postoperative patient who presents with pain, infection, or palpable mass. PMID:26312116

  6. The Pathogen of the Great Barrier Reef Sponge Rhopaloeides odorabile Is a New Strain of Pseudoalteromonas agarivorans Containing Abundant and Diverse Virulence-Related Genes.

    PubMed

    Choudhury, Jayanta D; Pramanik, Arnab; Webster, Nicole S; Llewellyn, Lyndon E; Gachhui, Ratan; Mukherjee, Joydeep

    2015-08-01

    Sponge diseases have increased dramatically, yet the causative agents of disease outbreaks have eluded identification. We undertook a polyphasic taxonomic analysis of the only confirmed sponge pathogen and identified it as a novel strain of Pseudoalteromonas agarivorans. 16S ribosomal RNA (rRNA) and gyraseB (gyrB) gene sequences along with phenotypic characteristics demonstrated that strain NW4327 was most closely related to P. agarivorans. DNA-DNA hybridization and in silico genome comparisons established NW4327 as a novel strain of P. agarivorans. Genes associated with type IV pili, mannose-sensitive hemagglutinin pili, and curli formation were identified in NW4327. One gene cluster encoding ATP-binding cassette (ABC) transporter, HlyD and TolC, and two clusters related to the general secretion pathway indicated the presence of type I secretion system (T1SS) and type II secretion system (T2SS), respectively. A contiguous gene cluster of at least 19 genes related to type VI secretion system (T6SS) which included all 13 core genes was found. The absence of T1SS and T6SS in nonpathogenic P. agarivorans S816 established NW4327 as the virulent strain. Serine proteases and metalloproteases of the classes S8, S9, M4, M6, M48, and U32 were identified in NW4327, many of which can degrade collagen. Collagenase activity in NW4327 and its absence in the nonpathogenic P. agarivorans KMM 255(T) reinforced the invasiveness of NW4327. This is the first report unambiguously identifying a sponge pathogen and providing the first insights into the virulence genes present in any pathogenic Pseudoalteromonas genome. The investigation supports a theoretical study predicting high abundance of terrestrial virulence gene homologues in marine bacteria. PMID:25837832

  7. Transmural penetration of sigmoid colon and rectum by retained surgical sponge after hysterectomy.

    PubMed

    Shin, Woo Young; Im, Chan Hyuk; Choi, Sun Keun; Choe, Yun-Mee; Kim, Kyung Rae

    2016-03-14

    Gossypiboma is a surgical sponge that is retained in the body after the operation. A 39-year-old female presented with vague lower abdominal pain, fever, and rectal discharge 15 mo after hysterectomy. The sponge remaining in the abdomen had no radiopaque marker. Therefore a series of radiographic evaluations was fruitless. The surgical sponge was found in the rectosigmoid colon on colonoscopy. The sponge penetrated the sigmoid colon and rectum transmurally, forming an opening on both sides. The patient underwent low anterior resection and was discharged without postoperative complications. PMID:26973401

  8. Composition of Archaea in seawater, sediment, and sponges in the Kepulauan Seribu reef system, Indonesia.

    PubMed

    Polónia, Ana R M; Cleary, Daniel F R; Duarte, Leticia N; de Voogd, Nicole J; Gomes, Newton C M

    2014-04-01

    Coral reefs are among the most diverse and productive ecosystems in the world. Most research has, however, focused on eukaryotes such as corals and fishes. Recently, there has been increasing interest in the composition of prokaryotes, particularly those inhabiting corals and sponges, but these have mainly focused on bacteria. There have been very few studies of coral reef Archaea, despite the fact that Archaea have been shown to play crucial roles in nutrient dynamics, including nitrification and methanogenesis, of oligotrophic environments such as coral reefs. Here, we present the first study to assess Archaea in four different coral reef biotopes (seawater, sediment, and two sponge species, Stylissa massa and Xestospongia testudinaria). The archaeal community of both sponge species and sediment was dominated by Crenarchaeota, while the seawater community was dominated by Euryarchaeota. The biotope explained more than 72% of the variation in archaeal composition. The number of operational taxonomic units (OTUs) was highest in sediment and seawater biotopes and substantially lower in both sponge hosts. No "sponge-specific" archaeal OTUs were found, i.e., OTUs found in both sponge species but absent from nonhost biotopes. Despite both sponge species hosting phylogenetically distinct microbial assemblages, there were only minor differences in Kyoto Encyclopedia of Genes and Genomes (KEGG) functional pathways. In contrast, most functional pathways differed significantly between microbiomes from sponges and nonhost biotopes including all energy metabolic pathways. With the exception of the methane and nitrogen metabolic pathway, all energy metabolic pathways were enriched in sponges when compared to nonhost biotopes. PMID:24477923

  9. Transmural penetration of sigmoid colon and rectum by retained surgical sponge after hysterectomy

    PubMed Central

    Shin, Woo Young; Im, Chan Hyuk; Choi, Sun Keun; Choe, Yun-Mee; Kim, Kyung Rae

    2016-01-01

    Gossypiboma is a surgical sponge that is retained in the body after the operation. A 39-year-old female presented with vague lower abdominal pain, fever, and rectal discharge 15 mo after hysterectomy. The sponge remaining in the abdomen had no radiopaque marker. Therefore a series of radiographic evaluations was fruitless. The surgical sponge was found in the rectosigmoid colon on colonoscopy. The sponge penetrated the sigmoid colon and rectum transmurally, forming an opening on both sides. The patient underwent low anterior resection and was discharged without postoperative complications. PMID:26973401

  10. Glycosides from marine sponges (Porifera, Demospongiae): structures, taxonomical distribution, biological activities and biological roles.

    PubMed

    Kalinin, Vladimir I; Ivanchina, Natalia V; Krasokhin, Vladimir B; Makarieva, Tatyana N; Stonik, Valentin A

    2012-08-01

    Literature data about glycosides from sponges (Porifera, Demospongiae) are reviewed. Structural diversity, biological activities, taxonomic distribution and biological functions of these natural products are discussed. PMID:23015769

  11. Glycosides from Marine Sponges (Porifera, Demospongiae): Structures, Taxonomical Distribution, Biological Activities and Biological Roles

    PubMed Central

    Kalinin, Vladimir I.; Ivanchina, Natalia V.; Krasokhin, Vladimir B.; Makarieva, Tatyana N.; Stonik, Valentin A.

    2012-01-01

    Literature data about glycosides from sponges (Porifera, Demospongiae) are reviewed. Structural diversity, biological activities, taxonomic distribution and biological functions of these natural products are discussed. PMID:23015769

  12. Chitosan-hyaluronic acid/nano silver composite sponges for drug resistant bacteria infected diabetic wounds.

    PubMed

    Anisha, B S; Biswas, Raja; Chennazhi, K P; Jayakumar, R

    2013-11-01

    The aim of this work was to develop an antimicrobial sponge composed of chitosan, hyaluronic acid (HA) and nano silver (nAg) as a wound dressing for diabetic foot ulcers (DFU) infected with drug resistant bacteria. nAg (5-20 nm) was prepared and characterized. The nanocomposite sponges were prepared by homogenous mixing of chitosan, HA and nAg followed by freeze drying to obtain a flexible and porous structure. The prepared sponges were characterized using SEM and FT-IR. The porosity, swelling, biodegradation and haemostatic potential of the sponges were also studied. Antibacterial activity of the prepared sponges was analysed using Escherichia coli, Staphylococcus aureus, methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa and Klebsiella pneumonia. Chitosan-HA/nAg composite sponges showed potent antimicrobial property against the tested organisms. Sponges containing higher nAg (0.005%, 0.01% and 0.02%) concentrations showed antibacterial activity against MRSA. Cytotoxicity and cell attachment studies were done using human dermal fibroblast cells. The nanocomposite sponges showed a nAg concentration dependent toxicity towards fibroblast cells. Our results suggest that this nanocomposite sponges could be used as a potential material for wound dressing for DFU infected with antibiotic resistant bacteria if the optimal concentration of nAg exhibiting antibacterial action with least toxicity towards mammalian cells is identified. PMID:24060281

  13. Drivers of epibenthic megafaunal composition in the sponge grounds of the Sackville Spur, northwest Atlantic

    NASA Astrophysics Data System (ADS)

    Beazley, Lindsay; Kenchington, Ellen; Yashayaev, Igor; Murillo, Francisco Javier

    2015-04-01

    Deep-water sponges are considered ecosystem engineers, and the presence of large aggregations of these organisms, commonly referred to as sponge grounds, is associated with enhanced biodiversity and abundance of epibenthic fauna compared to non-sponge habitat. However, the degree and magnitude to which the presence of these sponge grounds elicits large changes in composition of the associated megafaunal community remains unknown. Here we identify the external drivers of epibenthic megafaunal community composition and explore the patterns and magnitude of compositional change in the megafaunal community within the sponge grounds of the Sackville Spur, northwest Atlantic. Epibenthic megafauna were quantified from five image transects collected on the Sackville Spur in 2009 between 1080 and 1723 m depth. Using Gradient Forest Modelling we found that the abundance of structure-forming sponges was the most important variable for predicting compositional patterns in the Sackville Spur megafaunal community, followed by depth, range in bottom current speed, in situ salinity, and longitude. Along the gradient in structure-forming sponge abundance, the largest turnover in megafaunal community composition occurred when the sponges reached 15 individuals m-2. Examination of the regional hydrographic conditions suggests that the dense sponge grounds of the Sackville Spur are associated with a warm, salty water mass that occurs between ~1300 and 1800 m.

  14. SilE is an intrinsically disordered periplasmic "molecular sponge" involved in bacterial silver resistance.

    PubMed

    Asiani, Karishma R; Williams, Huw; Bird, Louise; Jenner, Matthew; Searle, Mark S; Hobman, Jon L; Scott, David J; Soultanas, Panos

    2016-09-01

    Ag(+) resistance was initially found on the Salmonella enetrica serovar Typhimurium multi-resistance plasmid pMG101 from burns patients in 1975. The putative model of Ag(+) resistance, encoded by the sil operon from pMG101, involves export of Ag(+) via an ATPase (SilP), an effluxer complex (SilCFBA) and a periplasmic chaperon of Ag(+) (SilE). SilE is predicted to be intrinsically disordered. We tested this hypothesis using structural and biophysical studies and show that SilE is an intrinsically disordered protein in its free apo-form but folds to a compact structure upon optimal binding to six Ag(+) ions in its holo-form. Sequence analyses and site-directed mutagenesis established the importance of histidine and methionine containing motifs for Ag(+) -binding, and identified a nucleation core that initiates Ag(+) -mediated folding of SilE. We conclude that SilE is a molecular sponge for absorbing metal ions. PMID:27085056

  15. Temperature-dependent structural behavior of self-avoiding walks on three-dimensional Sierpinski sponges.

    PubMed

    Fritsche, Miriam; Heermann, Dieter W

    2010-05-01

    The statistics of self-avoiding random walks (SAWs), consisting of up to N=1280 steps, on deterministic fractal structures with infinite ramification, modeled by Sierpinski cubic lattices, in the presence of a finite temperature is investigated as a model for polymers absorbed on a disordered medium. Thereby, the three-dimensional Sierpinski sponge is defined by two types of sites with energy 0 and ϵ>0 , respectively, yielding a deterministic fractal energy landscape. The probability distribution function of the end-to-end distance of SAWs is obtained and its scaling behavior studied. In the limiting case of temperature T → ∞, the known behavior of SAWs on regular cubic lattices is recovered, while for T → 0 the resulting scaling exponents are confronted with previous calculations for much shorter linear chains based on the exact enumeration technique. For finite temperatures, the structural behavior of SAWs in three dimensions is compared to its two-dimensional counterpart and found to be intermediate between the two limiting cases (T → 0 and T → ∞, respectively), where the characteristic exponents, however, display a nontrivial dependence on temperature. PMID:20866197

  16. Cytotoxic Sesterterpenoids Isolated from the Marine Sponge Scalarispongia sp.

    PubMed Central

    Lee, Yeon-Ju; Lee, Jeong-Woo; Lee, Dong-Geun; Lee, Hyi-Seung; Kang, Jong Soon; Yun, Jieun

    2014-01-01

    Eight scalarane sesterterpenoids, including four new compounds, were isolated from the marine sponge Scalarispongia sp. The structures of the new compounds were elucidated by 2D-NMR and HRMS analyses. All of the isolated compounds, with the exception of 16-O-deacetyl-12,16-epi-scalarolbutanolide, showed significant in vitro cytotoxicity (GI50 values down to 5.2 μM) against six human cancer cell lines. PMID:25375188

  17. Sponge derived bromotyrosines: structural diversity through natural combinatorial chemistry.

    PubMed

    Niemann, Hendrik; Marmann, Andreas; Lin, Wenhan; Proksch, Peter

    2015-01-01

    Sponge derived bromotyrosines are a multifaceted class of marine bioactive compounds that are important for the chemical defense of sponges but also for drug discovery programs as well as for technical applications in the field of antifouling constituents. These compounds, which are mainly accumulated by Verongid sponges, exhibit a diverse range of bioactivities including antibiotic, cytotoxic and antifouling effects. In spite of the simple biogenetic building blocks, which consist only of brominated tyrosine and tyramine units, an impressive diversity of different compounds is obtained through different linkages between these precursors and through structural modifications of the side chains and/or aromatic rings resembling strategies that are known from combinatorial chemistry. As examples for bioactive, structurally divergent bromotyrosines psammaplin A, Aplysina alkaloids featuring aerothionin, aeroplysinin-1 and the dienone, and the bastadins, including the synthetically derived hemibastadin congeners, have been selected for this review. Whereas all of these natural products are believed to be involved in the chemical defense of sponges, some of them may also be of particular relevance to drug discovery due to their interaction with specific molecular targets in eukaryotic cells. These targets involve important enzymes and receptors, such as histone deacetylases (HDAC) and DNA methyltransferases (DNMT), which are inhibited by psammaplin A, as well as ryanodine receptors that are targeted by bastadine type compounds. The hemibastadins such as the synthetically derived dibromohemibastadin are of particular interest due to their antifouling activity. For the latter, a phenoloxidase which catalyzes the bioglue formation needed for firm attachment of fouling organisms to a given substrate was identified as a molecular target. The Aplysina alkaloids finally provide a vivid example for dynamic wound induced bioconversions of natural products that generate highly

  18. New cytotoxic cyclic peroxide acids from Plakortis sp. marine sponge

    PubMed Central

    Hoye, Thomas R.; Alarif, Walied M.; Basaif, Salim S.; Abo-Elkarm, Mohamed; Hamann, Mark T.; Wahba, Amir E.; Ayyad, Seif-Eldin N.

    2016-01-01

    Bioassay-guided fractionation of the extract of Jamaican marine sponge Plakortis sp. followed by preparative TLC and HPLC yielded several known methyl ester cyclic peroxides (1a, 2a, 3a, 4, 5), known plakortides (6,7), known bicyclic lactone (8) and new cyclic peroxide acids (1b, 2b, 3b). The chemical structures were elucidated by extensive interpretation of their spectroscopic data. These natural products showed remarkable in vitro cytotoxicity against several cancer cell lines. PMID:26835518

  19. Understanding Zika virus pathogenesis: an interview with Catherine Spong.

    PubMed

    Spong, Catherine Y

    2016-01-01

    A recent outbreak of Zika virus has been linked to fetal abnormalities in pregnant women who have been infected. The scientific community is working toward understanding Zika virus pathogenesis to better manage affected women and children. In an interview with Dr. Catherine Spong, we discuss the aims and challenges of a forthcoming longitudinal study of a cohort of pregnant women in areas of current active Zika virus transmission. PMID:27268016

  20. LCAO approximation for scaling properties of the Menger sponge fractal.

    PubMed

    Sakoda, Kazuaki

    2006-11-13

    The electromagnetic eigenmodes of a three-dimensional fractal called the Menger sponge were analyzed by the LCAO (linear combination of atomic orbitals) approximation and a first-principle calculation based on the FDTD (finite-difference time-domain) method. Due to the localized nature of the eigenmodes, the LCAO approximation gives a good guiding principle to find scaled eigenfunctions and to observe the approximate self-similarity in the spectrum of the localized eigenmodes. PMID:19529555

  1. PLLA-collagen and PLLA-gelatin hybrid scaffolds with funnel-like porous structure for skin tissue engineering

    NASA Astrophysics Data System (ADS)

    Lu, Hongxu; Oh, Hwan Hee; Kawazoe, Naoki; Yamagishi, Kozo; Chen, Guoping

    2012-12-01

    In skin tissue engineering, a three-dimensional porous scaffold is necessary to support cell adhesion and proliferation and to guide cells moving into the repair area in the wound healing process. Structurally, the porous scaffold should have an open and interconnected porous architecture to facilitate homogenous cell distribution. Moreover, the scaffolds should be mechanically strong to protect deformation during the formation of new skin. In this study, the hybrid scaffolds were prepared by forming funnel-like collagen or gelatin sponge on a woven poly(l-lactic acid) (PLLA) mesh. The hybrid scaffolds combined the advantages of both collagen or gelatin (good cell-interactions) and PLLA mesh (high mechanical strength). The hybrid scaffolds were used to culture dermal fibroblasts for dermal tissue engineering. The funnel-like porous structure promoted homogeneous cell distribution and extracellular matrix production. The PLLA mesh reinforced the scaffold to avoid deformation. Subcutaneous implantation showed that the PLLA-collagen and PLLA-gelatin scaffolds promoted the regeneration of dermal tissue and epidermis and reduced contraction during the formation of new tissue. These results indicate that funnel-like hybrid scaffolds can be used for skin tissue regeneration.

  2. Methotrexate Locally Released from Poly(e-Caprolactone) Implants: Inhibition of the Inflammatory Angiogenesis Response in a Murine Sponge Model and the Absence of Systemic Toxicity.

    PubMed

    De Oliveira, Leandro Gonzaga; Figueiredo, Letîcia Aparecida; Fernandes-Cunha, Gabriella Maria; Marina Barcelos, De Miranda; Machado, Laser Antonio; Dasilva, Gisele Rodrigues; Sandra Aparecida Lima, De Moura

    2015-11-01

    In this study, the methotrexate (MTX) was incorporated into the poly(e-caprolactone) (PCL) to design implants (MTX PCL implants) aiming the local treatment of inflammatory angiogenesis diseases without causing systemic side effects. Sponges were inserted into the subcutaneous tissue of mice as a framework for fibrovascular tissue growth. After 4days, MTX PCL implants were also introduced, and anti-inflammatory, antiangiogenic, and antifibrogenic activities of the MTX were determined. MTX reduced the vascularization (hemoglobin content), the neutrophil, and monocyte/macrophage infiltration (MPO and NAG activities, respectively), and the collagen deposition in sponges. MTX reduced tumor necrosis factor-a and IL-6 levels, demonstrating its local antiangiogenic and anti-inflammatory effects. Furthermore, hepatotoxicity, nephrotoxicity, and myelotoxicity, which could be induced by the drug, were evaluated. However, MTX did not promote toxicity to these organs, as the levels of AST and ALT (hepatic markers) and creatinine and urea (renal markers) were not increased, and the complete blood count was not decreased. In conclusion, MTX PCL implants demonstrated to be effective in regulating the components of the inflammatory angiogenesis locally established, and presented an acceptable safety profile. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 104:3731-3742, 2015. PMID:27524686

  3. Restructuring of the sponge microbiome favors tolerance to ocean acidification.

    PubMed

    Ribes, M; Calvo, E; Movilla, J; Logares, R; Coma, R; Pelejero, C

    2016-08-01

    Ocean acidification is increasing and affects many marine organisms. However, certain sponge species can withstand low-pH conditions. This may be related to their complex association with microbes. We hypothesized that species with greater microbial diversity may develop functional redundancy that could enable the holobiont to survive even if particular microbes are lost at low-pH conditions. We evaluated the effects of acidification on the growth and associated microbes of three ubiquitous Mediterranean sponges by exposing them to the present pH level and that predicted for the year 2100. We found marked differences among the species in the acquisition of new microbes, being high in Dysidea avara, moderate in Agelas oroides and null in Chondrosia reniformis; however, we did not observe variation in the overall microbiome abundance, richness or diversity. The relative abilities to alter the microbiomes contributes to survivorship in an OA scenario as demonstrated by lowered pH severely affecting the growth of C. reniformis, halving that of A. oroides, and unaffecting D. avara. Our results indicate that functional stability of the sponge holobiont to withstand future OA is species-specific and is linked to the species' ability to use horizontal transmission to modify the associated microbiome to adapt to environmental change. PMID:27264698

  4. The Size of Gelatin Sponge Particles: Differences with Preparation Method

    SciTech Connect

    Katsumori, Tetsuya Kasahara, Toshiyuki

    2006-12-15

    Purpose. To assess whether the size distribution of gelatin sponge particles differed according to the method used to make them and the type of original sheet. Methods. Gelatin sponge particles of approximately 1-1.5 x 1-1.5 x 2 mm were made from either Spongel or Gelfoam sheets by cutting with a scalpel and scissors. Particles were also made of either Spongel or Gelfoam sheets by pumping with two syringes and a three-way stopcock. The size distribution of the particles in saline was compared among the groups. Results. (1) Cutting versus pumping: When Spongel was used, cutting produced lower rates of smaller particles {<=}500 {mu}m and larger particles >2000 {mu}m compared with pumping back and forth 30 times (1.1% vs 37.6%, p < 0.0001; 2.2% vs 14.4%, p = 0.008). When Gelfoam was used, cutting produced lower rates of smaller and larger particles compared with pumping (8.5% vs 20.4%, p = 0.1809; 0% vs 48.1%, p < 0.0001). (2) Spongel versus Gelfoam: There was no significant difference in the size distribution of the particles between Spongel and Gelfoam (p = 0.2002) when cutting was used. Conclusion. The size distribution of gelatin sponge particles differed according to the method used to make them. More uniform particle sizes can be achieved by cutting than by pumping.

  5. Preparation of hydrophilic luffa sponges and their water absorption performance.

    PubMed

    Liu, Zhi; Pan, Yanxiong; Shi, Kai; Wang, Weicai; Peng, Chao; Li, Wei; Sha, Di; Wang, Zhe; Ji, Xiangling

    2016-08-20

    Hydrophilic luffa sponges are prepared by grafting polymerization of acrylamide (AM) on luffa cylindrica and subsequent partial hydrolysis under alkaline conditions. Attenuated total reflection infrared spectroscopy is used to verify the composition of the grafted (luffa-g-PAM) and hydrolyzed (luffa-g-(PAM-co-PAANa)) samples. Alkalization conditions, including aqueous NaOH concentrations, alkalization temperature, and time, are studied extensively. Optimized conditions are then obtained. The grafting percentage (GP) of polyacrylamide increases with the feed ratios of [AM]/[OH] and [Ce]/[OH], reaction temperature, and time. Furthermore, the GP can reach up to 160%. Pristine, alkalized, grafted, and hydrolyzed luffa sponges show rapid absorption kinetics, and the pseudo second-order rate equation is applied to describe their kinetic procedure. Reaction conditions, such as [AM]/[OH], [Ce]/[OH], reaction temperature and time, influence the water absorption capacities of grafted and hydrolyzed samples. The hydrolyzed luffa sponges particularly exhibit high water absorption capacities of 75gg(-1). The absorption mechanism is also discussed. PMID:27178923

  6. Secondary Metabolites from Three Florida Sponges with Antidepressant Activity

    PubMed Central

    Kochanowska, Anna J.; Rao, Karumanchi V.; Childress, Suzanne; El-Alfy, Abir; Matsumoto, Rae R.; Kelly, Michelle; Stewart, Gina S.; Sufka, Kenneth J.; Hamann, Mark T.

    2016-01-01

    Brominated indole alkaloids are a common class of metabolites reported from sponges of the order Verongida. Herein we report the isolation, structure determination, and activity of metabolites from three Florida sponges, namely, Verongula rigida (order Verongida, family Aplysinidae), Smenospongia aurea, and S. cerebriformis (order Dictyoceratida, family Thorectidae). All three species were investigated chemically, revealing similarities in secondary metabolites. Brominated compounds, as well as sesquiterpene quinones and hydroquinones, were identified from both V. rigida and S. aurea despite their apparent taxonomic differences at the ordinal level. Similar metabolites found in these distinct sponge species of two different genera provide evidence for a microbial origin of the metabolites. Isolated compounds were evaluated in the Porsolt forced swim test (FST) and the chick anxiety–depression continuum model. Among the isolated compounds, 5,6-dibromo-N,N-dimethyltryptamine (1) exhibited significant antidepressant-like action in the rodent FST model, while 5-bromo-N,N-dimethyltryptamine (2) caused significant reduction of locomotor activity indicative of a potential sedative action. The current study provides ample evidence that marine natural products with the diversity of brominated marine alkaloids will provide potential leads for antidepressant and anxiolytic drugs. PMID:18217716

  7. Biosorption of lead by maize (Zea mays) stalk sponge.

    PubMed

    García-Rosales, G; Colín-Cruz, A

    2010-11-01

    This study investigated the removal of Pb(II) from aqueous solutions by a maize (Zea mays) stalk sponge. Equilibrium and kinetic models for Pb(II) sorption were developed by considering the effect of the contact time and concentration at the optimum pH of 6 +/- 0.2. The Freundlich model was found to describe the sorption energetics of Pb(II) by Z. mays stalk sponge, and a maximum Pb(II) loading capacity of 80 mg g(-1) was determined. The kinetic parameters were obtained by fitting data from experiments measuring the effect of contact time on adsorption capacity into pseudo-first and second-order equations. The kinetics of Pb(II) sorption onto Z. mays biosorbent were well defined using linearity coefficients (R(2)) by the pseudo-second-order equation (0.9998). The results obtained showed that Zea may stalk sponge was a useful biomaterial for Pb(II) sorption and that pH has an important effect on metal biosorption capacity. PMID:20615602

  8. Periodontal tissue regeneration with PRP incorporated gelatin hydrogel sponges.

    PubMed

    Nakajima, Dai; Tabata, Yasuhiko; Sato, Soh

    2015-09-01

    Gelatin hydrogels have been designed and prepared for the controlled release of the transforming growth factor (TGF-b1) and the platelet-derived growth factor (PDGF-BB). PRP (Platelet rich plasma) contains many growth factors including the PDGF and TGF-b1. The objective of this study was to evaluate the regeneration of periodontal tissue following the controlled release of growth factors in PRP. For the periodontal ligament cells and osteoblast, PRP of different concentrations was added. The assessment of DNA, mitochondrial activity and ALP activity were measured. To evaluate the TGF-β1 release from PRP incorporated gelatin sponge, amounts of TGF-β1 in each supernatant sample were determined by the ELISA. Transplantation experiments to prepare a bone defect in a rat alveolar bone were an implanted gelatin sponge incorporated with different concentration PRP. In DNA assay and MTT assay, after the addition of PRP to the periodontal ligament cells and osteoblast, the cell count and mitochondrial activity had increased the most in the group with the addition of 5  ×  PRP. In the ALP assay, after the addition of PRP to the periodontal ligament cells, the cell activity had increased the most in the group with the addition of 3  ×  PRP. In the transplantation, the size of the bone regenerated in the defect with 3  ×  PRP incorporated gelatin sponge was larger than that of the other group. PMID:26481592

  9. Preparation and characterization of sponge film made from feathers.

    PubMed

    Zhuang, Yuan; Wu, Xiaoqian; Cao, Zhangjun; Zhao, Xiaoxiang; Zhou, Meihua; Gao, Pin

    2013-12-01

    Feather wastes generated from poultry farms will pose a problem for disposal, but they are sustainable resources of keratin. Reduction is one of the commonly used methods to obtain soluble keratin from feather. However, the residues generated during feather reduction reaction were rarely investigated. In this study, the residues were transformed into a porous and flexible sponge film by freeze-drying without pretreatment or addition of cross-linking agents. Glycerol was used to alter the physical and chemical characteristics of the sponge film. The film was characterized with a fiber strong stretch instrument, a Fourier transform infrared spectrophotometer, scanning electron microscopy, an elemental analyzer, a differential scanning calorimeter and an automatic air permeability apparatus. Tensile strength and melting point of the sponge film with the optimum glycerol content were 6.2 MPa and 170°C respectively. Due to air permeability of 368 mm/s, the film can potentially be used in medicine, biology, textile, environmental technology, and so on. It is ecologically friendly and will produce additional benefits from the renewable materials. The film was utilized as adsorbents to remove Cr(VI) from aqueous solutions and as a filtering material for air pollution. Its maximum Cr(VI) uptake capacity was about 148.8 mg/g and the removal rate of PM10 was 98.3%. PMID:24094181

  10. Nonlinear optical response of the collagen triple helix and second harmonic microscopy of collagen liquid crystals

    NASA Astrophysics Data System (ADS)

    Deniset-Besseau, A.; De Sa Peixoto, P.; Duboisset, J.; Loison, C.; Hache, F.; Benichou, E.; Brevet, P.-F.; Mosser, G.; Schanne-Klein, M.-C.

    2010-02-01

    Collagen is characterized by triple helical domains and plays a central role in the formation of fibrillar and microfibrillar networks, basement membranes, as well as other structures of the connective tissue. Remarkably, fibrillar collagen exhibits efficient Second Harmonic Generation (SHG) and SHG microscopy proved to be a sensitive tool to score fibrotic pathologies. However, the nonlinear optical response of fibrillar collagen is not fully characterized yet and quantitative data are required to further process SHG images. We therefore performed Hyper-Rayleigh Scattering (HRS) experiments and measured a second order hyperpolarisability of 1.25 10-27 esu for rat-tail type I collagen. This value is surprisingly large considering that collagen presents no strong harmonophore in its amino-acid sequence. In order to get insight into the physical origin of this nonlinear process, we performed HRS measurements after denaturation of the collagen triple helix and for a collagen-like short model peptide [(Pro-Pro-Gly)10]3. It showed that the collagen large nonlinear response originates in the tight alignment of a large number of weakly efficient harmonophores, presumably the peptide bonds, resulting in a coherent amplification of the nonlinear signal along the triple helix. To illustrate this mechanism, we successfully recorded SHG images in collagen liquid solutions by achieving liquid crystalline ordering of the collagen triple helices.

  11. Cloning of an annelid fibrillar-collagen gene and phylogenetic analysis of vertebrate and invertebrate collagens.

    PubMed

    Sicot, F X; Exposito, J Y; Masselot, M; Garrone, R; Deutsch, J; Gaill, F

    1997-05-15

    Arenicola marina possesses cuticular and interstitial collagens, which are mostly synthesised by its epidermis. A cDNA library was constructed from the body wall. This annelid cDNA library was screened with a sea-urchin-collagen cDNA probe, and several overlapping clones were isolated. Nucleotide sequencing of these clones revealed an open reading frame of 2052 nucleotides. The translation product exhibits a triple helical domain of 138 Gly-Xaa-Yaa repeats followed by a 269-residue-long C-terminal non-collagenous domain (C-propeptide). The triple helical domain exhibits an imperfection that has been previously described in a peptide produced by cyanogen bromide digestion (CNBr peptide) of A. marina interstitial collagen. This imperfection occurs at the same place in the interstitial collagen of the vestimentiferan Riftia pachyptila. This identifies the clone as coding for the C-terminal part of a fibrillar collagen chain. It was called FAm1alpha, for fibrillar collagen 1alpha chain of A. marina. The non-collagenous domain possesses a structure similar to carboxy-terminal propeptides of fibrillar pro-alpha chains. Only six conserved cysteine residues are observed in A. marina compared with seven or eight in all other known C-propeptides. This provides information on the importance of disulfide bonds in C-propeptide interactions and in the collagen-assembly process. Phylogenetic studies indicate that the fibrillar collagen 1alpha chain of A. marina is homologous to the R. pachyptila interstitial collagen and that the FAm1alpha gene evolved independently from the other alpha-chain genes. Complementary analyses indicate that the vertebrate fibrillar collagen family is composed of two monophyletic subgroups with a specific position of the collagen type-V chains. PMID:9210465

  12. The Mineral–Collagen Interface in Bone

    PubMed Central

    2015-01-01

    The interface between collagen and the mineral reinforcement phase, carbonated hydroxyapatite (cAp), is essential for bone’s remarkable functionality as a biological composite material. The very small dimensions of the cAp phase and the disparate natures of the reinforcement and matrix are essential to the material’s performance but also complicate study of this interface. This article summarizes what is known about the cAp-collagen interface in bone and begins with descriptions of the matrix and reinforcement roles in composites, of the phases bounding the interface, of growth of cAp growing within the collagen matrix, and of the effect of intra- and extrafibrilar mineral on determinations of interfacial properties. Different observed interfacial interactions with cAp (collagen, water, non-collagenous proteins) are reviewed; experimental results on interface interactions during loading are reported as are their influence on macroscopic mechanical properties; conclusions of numerical modeling of interfacial interactions are also presented. The data suggest interfacial interlocking (bending of collagen molecules around cAp nanoplatelets) and water-mediated bonding between collagen and cAp are essential to load transfer. The review concludes with descriptions of areas where new research is needed to improve understanding of how the interface functions. PMID:25824581

  13. Single-molecule studies of collagen mechanics

    NASA Astrophysics Data System (ADS)

    Forde, Nancy; Rezaei, Naghmeh; Kirkness, Michael

    Collagen is the fundamental structural protein in vertebrates. Its triple helical structure at the molecular level is believed to be strongly related to its mechanical role in connective tissues. However, the mechanics of collagen at the single-molecule level remain contentious. Estimates of its persistence length span an order of magnitude, from 15-180 nm for this biopolymer of 300 nm contour length. How collagen responds to applied force is also controversial, with different single-molecule studies suggesting one of three different responses: extending entropically, overwinding, or unwinding, all at forces below 10 pN. Using atomic force microscopy to image collagens deposited from solution, we find that their flexibility depends strongly on ionic strength and pH. To study force-dependent structural changes, we are performing highly parallelized enzymatic cleavage assays of triple helical collagen in our new compact centrifuge force microscope. Because proteolytic cleavage requires a locally unwound triple helix, these experiments are revealing how local collagen structure changes in response to applied force. Our results can help to resolve long-standing debates about collagen mechanics and structure at the molecular level.

  14. Age-related crosslink in skin collagen

    SciTech Connect

    Yamauchi, M.; Mechanic, G.

    1986-05-01

    A stable crosslinking amino acid was isolated from mature bovine skin collagen and its structure was identified as histidinohydroxylysinonorleucine (HHL) using fast atom bombardment mass spectrometry and /sup 1/H, /sup 13/C-NMR. This newly identified crosslink has a linkage between C-2 histidine and C-6 of lysine in the latter's portion of hydroxylysinonorleucine. Quantitative studies using various aged samples of cow and human skin collagen indicated that this acid-heat stable nonreducible compound was the major age-related crosslink. In case of cow skin collagen, for example, during early embryonic development (3 and 5 month old embryos) the content of HHL stayed less than 0.01 residue/mole of collagen, however from the middle of gestation period (7 month old embryo) through the maturation stage it showed rapid increase with age and reached approximately 0.5 residues/mole of collagen in the 3 year old animal. Small increments (up to 0.65 res/mole of collagen) were observed in the 9 year old cow. The amounts of the crosslink unlike pyridinoline do not decrease with aging. Similar patterns were observed in human skin collagen.

  15. Collagen-platelet interactions: recognition and signalling.

    PubMed

    Farndale, Richard W; Siljander, Pia R; Onley, David J; Sundaresan, Pavithra; Knight, C Graham; Barnes, Michael J

    2003-01-01

    The collagen-platelet interaction is central to haemostasis and may be a critical determinant of arterial thrombosis, where subendothelium is exposed after rupture of atherosclerotic plaque. Recent research has capitalized on the cloning of an important signalling receptor for collagen, glycoprotein VI, which is expressed only on platelets, and on the use of collagen-mimetic peptides as specific tools for both glycoprotein VI and integrin alpha 2 beta 1. We have identified sequences, GPO and GFOGER (where O denotes hydroxyproline), within collagen that are recognized by the collagen receptors glycoprotein VI and integrin alpha 2 beta 1 respectively, allowing their signalling properties and specific functional roles to be examined. Triple-helical peptides containing these sequences were used to show the signalling potential of integrin alpha 2 beta 1, and to confirm its important contribution to platelet adhesion. Glycoprotein VI appears to operate functionally on the platelet surface as a dimer, which recognizes GPO motifs that are separated by four triplets of collagen sequence. These advances will allow the relationship between the structure of collagen and its haemostatic activity to be established. PMID:14587284

  16. Nanoscale Mechanics of Type I Collagen

    NASA Astrophysics Data System (ADS)

    Harper, H.; Cropper, E.; Bulger, A.; Choksi, U.; Koob, T. J.; Pandit, S.; Matthews, W. G.

    2009-03-01

    Collagen is the most abundant protein in the body by mass. Type I collagen fibrils provide mechanical strength and cellular housing within tissues exhibiting a broad range of mechanical properties. This diversity in the mechanics of tissues with similar underlying components warrants detailed study of the process by which structure and mechanics develop. While collagen mechanics have been studied at the tissue level for decades, surprising little is known about collagen mechanics at the fibril and molecular level. Presented herein is a multi-scale experimental and computational investigation of collagen I mechanics, bridging the single molecule and fibril hierarchal forms. The mechanics of single collagen molecules are explored using AFM and force spectroscopy. Moreover, atomistic molecular-dynamics simulations are performed to provide structural information not accessible to the experimental system. Fibrils then are grown from molecular collagen, and the mechanics of these fibrils are investigated using AFM. Based upon the single molecule and fibril results, a coarse-grain computational model is being developed. The outcomes include a better understanding of how the mechanics of filamentous self-organizing systems are derived and how their hierarchical forms are established.

  17. Carbon Absorber Retrofit Equipment (CARE)

    SciTech Connect

    Klein, Eric

    2015-12-23

    During Project DE-FE0007528, CARE (Carbon Absorber Retrofit Equipment), Neumann Systems Group (NSG) designed, installed and tested a 0.5MW NeuStream® carbon dioxide (CO2) capture system using the patented NeuStream® absorber equipment and concentrated (6 molal) piperazine (PZ) as the solvent at Colorado Springs Utilities’ (CSU’s) Martin Drake pulverized coal (PC) power plant. The 36 month project included design, build and test phases. The 0.5MW NeuStream® CO2 capture system was successfully tested on flue gas from both coal and natural gas combustion sources and was shown to meet project objectives. Ninety percent CO2 removal was achieved with greater than 95% CO2product purity. The absorbers tested support a 90% reduction in absorber volume compared to packed towers and with an absorber parasitic power of less than 1% when configured for operation with a 550MW coal plant. The preliminary techno-economic analysis (TEA) performed by the Energy and Environmental Research Center (EERC) predicted an over-the-fence cost of $25.73/tonne of CO2 captured from a sub-critical PC plant.

  18. Mushroom plasmonic metamaterial infrared absorbers

    NASA Astrophysics Data System (ADS)

    Ogawa, Shinpei; Fujisawa, Daisuke; Hata, Hisatoshi; Uetsuki, Mitsuharu; Misaki, Koji; Kimata, Masafumi

    2015-01-01

    There has been a considerable amount of interest in the development of various types of electromagnetic wave absorbers for use in different wavelength ranges. In particular, infrared (IR) absorbers with wavelength selectivity can be applied to advanced uncooled IR sensors, which would be capable of identifying objects through their radiation spectrum. In the present study, mushroom plasmonic metamaterial absorbers (MPMAs) for the IR wavelength region were designed and fabricated. The MPMAs consist of a periodic array of thin metal micropatches connected to a thin metal plate with narrow silicon (Si) posts. A Si post height of 200 nm was achieved by isotropic XeF2 etching of a thin Si layer sandwiched between metal plates. This fabrication procedure is relatively simple and is consistent with complementary metal oxide semiconductor technology. The absorption spectra of the fabricated MPMAs were experimentally measured. In addition, theoretical calculations of their absorption properties were conducted using rigorous coupled wave analysis. Both the calculated and measured absorbance results demonstrated that these MPMAs can realize strong selective absorption at wavelengths beyond the period of the array by varying the micropatch width. Absorbance values greater than 90% were achieved. Dual- or single-mode absorption can also be selected by varying the width of the Si posts. Pixel structures using such MPMAs could be used as high responsivity, high resolution and fast uncooled IR sensors.

  19. Additive manufacturing of RF absorbers

    NASA Astrophysics Data System (ADS)

    Mills, Matthew S.

    The ability of additive manufacturing techniques to fabricate integrated electromagnetic absorbers tuned for specific radio frequency bands within structural composites allows for unique combinations of mechanical and electromagnetic properties. These composites and films can be used for RF shielding of sensitive electromagnetic components through in-plane and out-of-plane RF absorption. Structural composites are a common building block of many commercial platforms. These platforms may be placed in situations in which there is a need for embedded RF absorbing properties along with structural properties. Instead of adding radar absorbing treatments to the external surface of existing structures, which adds increased size, weight and cost; it could prove to be advantageous to integrate the microwave absorbing properties directly into the composite during the fabrication process. In this thesis, a method based on additive manufacturing techniques of composites structures with prescribed electromagnetic loss, within the frequency range 1 to 26GHz, is presented. This method utilizes screen printing and nScrypt micro dispensing to pattern a carbon based ink onto low loss substrates. The materials chosen for this study will be presented, and the fabrication technique that these materials went through to create RF absorbing structures will be described. The calibration methods used, the modeling of the RF structures, and the applications in which this technology can be utilized will also be presented.

  20. Mushroom plasmonic metamaterial infrared absorbers

    SciTech Connect

    Ogawa, Shinpei Fujisawa, Daisuke; Hata, Hisatoshi; Uetsuki, Mitsuharu; Misaki, Koji; Kimata, Masafumi

    2015-01-26

    There has been a considerable amount of interest in the development of various types of electromagnetic wave absorbers for use in different wavelength ranges. In particular, infrared (IR) absorbers with wavelength selectivity can be applied to advanced uncooled IR sensors, which would be capable of identifying objects through their radiation spectrum. In the present study, mushroom plasmonic metamaterial absorbers (MPMAs) for the IR wavelength region were designed and fabricated. The MPMAs consist of a periodic array of thin metal micropatches connected to a thin metal plate with narrow silicon (Si) posts. A Si post height of 200 nm was achieved by isotropic XeF{sub 2} etching of a thin Si layer sandwiched between metal plates. This fabrication procedure is relatively simple and is consistent with complementary metal oxide semiconductor technology. The absorption spectra of the fabricated MPMAs were experimentally measured. In addition, theoretical calculations of their absorption properties were conducted using rigorous coupled wave analysis. Both the calculated and measured absorbance results demonstrated that these MPMAs can realize strong selective absorption at wavelengths beyond the period of the array by varying the micropatch width. Absorbance values greater than 90% were achieved. Dual- or single-mode absorption can also be selected by varying the width of the Si posts. Pixel structures using such MPMAs could be used as high responsivity, high resolution and fast uncooled IR sensors.

  1. Nonventing, Regenerable, Lightweight Heat Absorber

    NASA Technical Reports Server (NTRS)

    Izenson, Michael G.; Chen, Weibo

    2008-01-01

    A lightweight, regenerable heat absorber (RHA), developed for rejecting metabolic heat from a space suit, may also be useful on Earth for short-term cooling of heavy protective garments. Unlike prior space-suit-cooling systems, a system that includes this RHA does not vent water. The closed system contains water reservoirs, tubes through which water is circulated to absorb heat, an evaporator, and an absorber/radiator. The radiator includes a solution of LiCl contained in a porous material in titanium tubes. The evaporator cools water that circulates through a liquid-cooled garment. Water vapor produced in the evaporator enters the radiator tubes where it is absorbed into the LiCl solution, releasing heat. Much of the heat of absorption is rejected to the environment via the radiator. After use, the RHA is regenerated by heating it to a temperature of 100 C for about 2 hours to drive the absorbed water back to the evaporator. A system including a prototype of the RHA was found to be capable of maintaining a temperature of 20 C while removing heat at a rate of 200 W for 6 hours.

  2. Isolation and characterization of collagen from the body wall of sea cucumber Stichopus monotuberculatus.

    PubMed

    Zhong, Ming; Chen, Ting; Hu, Chaoqun; Ren, Chunhua

    2015-04-01

    To exploit a new collagen resource from the body wall of tropical sea cucumber, pepsin-solubilized collagen of Stichopus monotuberculatus (PSC-Sm) was isolated and characterized with UV-vis spectra, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), amino acid composition, enzyme-digested peptide maps, Fourier transform infrared spectroscopy (FTIR), maximum transition temperature (Tm ), and solubilities. The maximum absorbance of PSC-Sm was exhibited at 218 nm in UV-vis spectra. The triple helical structure and activity of PSC-Sm could be indicated by FTIR. SDS-PAGE showed that the triple helix of PSC-Sm was formed as (α1 )3 by 3 α1 chain homologous with molecular weight of 137 kDa. The Tm of PSC-Sm and calf skin collagen (CSC) were 30.2 and 35.0 ºC, respectively, which consistent with the result of FTIR that CSC contained more stable triple-helix than PSC-Sm. Peptide maps were different between PSC-Sm and CSC, indicating the differences in their amino acid compositions and sequences. The maximum and minimum solubilities of PSC-Sm were observed at pH 2.0 and 4.0, respectively. A sharp decrease in solubility appeared when NaCl concentration was between 3% and 5%. These results showed that collagen from S. monotuberculatus had the type I collagen characteristics and good thermal stability, and therefore, it could be used as an alternative resource of collagen. PMID:25810305

  3. Fatal coccidioidomycosis in collagen vascular diseases.

    PubMed

    Johnson, W M; Gall, E P

    1983-02-01

    Ten patients who died from coccidioidomycosis in Arizona from 1968 to 1975 had underlying collagen vascular diseases: 4 with rheumatoid arthritis, 4 with systemic lupus erythematosus, and 2 with dermatomyositis. All 10 patients had been treated with corticosteroids; 2 were taking cytotoxic drugs. Collagen vascular diseases and the use of corticosteroids and cytotoxic drugs may be associated with the depression of cell-mediated immunity. The potential for opportunistic coccidioidomycosis should be noted when corticosteroids and cytotoxic drugs are used for treating collagen vascular disease in patients residing in or coming from areas where coccidioidomycosis is endemic. PMID:6842490

  4. Collagen plug occlusion of Molteno tube shunts.

    PubMed

    Stewart, W; Feldman, R M; Gross, R L

    1993-01-01

    We report five patients in whom collagen lacrimal plugs were used to temporarily occlude the lumen of Molteno shunts to prevent early postoperative hypotony. Only one eye, with a double plate, developed hypotony and a flat anterior chamber that required reformation. However, in three patients, the collagen plugs did not dissolve and had to be removed surgically to lower the intraocular pressure. Although the semipermeability of collagen is desirable, its unpredictable degradation renders it unsuitable for temporary occlusion of tube shunts. Other biodegradable materials may be more appropriate for this purpose. PMID:8446334

  5. Collagen stability, hydration and native state.

    PubMed

    Mogilner, Inés G; Ruderman, Graciela; Grigera, J Raúl

    2002-12-01

    Molecular dynamics simulations of a collagen-like peptide (Pro-Hyp-Gly)4-Pro-Hyp-Ala-(Pro-Hyp-Gly)5 have been done in order to study the contribution of the hydration structure on keeping the native structure of collagen. The simulation shows that the absence of water produces a distortion on the molecular conformation and an increase in the number of intra-molecular hydrogen bonds. This is in agreement with previous experimental results showing the stiffness of collagen under severe drying and its increase in the thermal stability. This dehydrated material does not keep, however, the native structure. PMID:12463639

  6. Estimates of Particulate Organic Carbon Flowing from the Pelagic Environment to the Benthos through Sponge Assemblages

    PubMed Central

    Perea-Blázquez, Alejandra; Davy, Simon K.; Bell, James J.

    2012-01-01

    Despite the importance of trophic interactions between organisms, and the relationship between primary production and benthic diversity, there have been few studies that have quantified the carbon flow from pelagic to benthic environments as a result of the assemblage level activity of suspension-feeding organisms. In this study, we examine the feeding activity of seven common sponge species from the Taputeranga marine reserve on the south coast of Wellington in New Zealand. We analysed the diet composition, feeding efficiency, pumping rates, and the number of food particles (specifically picoplanktonic prokaryotic cells) retained by sponges. We used this information, combined with abundance estimates of the sponges and estimations of the total amount of food available to sponges in a known volume of water (89,821 m3), to estimate: (1) particulate organic carbon (POC) fluxes through sponges as a result of their suspension-feeding activities on picoplankton; and (2) the proportion of the available POC from picoplankton that sponges consume. The most POC acquired by the sponges was from non-photosynthetic bacterial cells (ranging from 0.09 to 4.69 g C d−1 with varying sponge percentage cover from 0.5 to 5%), followed by Prochlorococcus (0.07 to 3.47 g C d−1) and then Synechococcus (0.05 to 2.34 g C d−1) cells. Depending on sponge abundance, the amount of POC that sponges consumed as a proportion of the total POC available was 0.2–12.1% for Bac, 0.4–21.3% for Prochlo, and 0.3–15.8% for Synecho. The flux of POC for the whole sponge assemblage, based on the consumption of prokaryotic picoplankton, ranged from 0.07–3.50 g C m2 d−1. This study is the first to estimate the contribution of a sponge assemblage (rather than focusing on individual sponge species) to POC flow from three groups of picoplankton in a temperate rocky reef through the feeding activity of sponges and demonstrates the importance of sponges to energy flow in rocky reef environments

  7. Chemical characterization, antioxidant and inhibitory effects of some marine sponges against carbohydrate metabolizing enzymes

    PubMed Central

    2012-01-01

    Background More than 15,000 marine products have been described up to now; Sponges are champion producers, concerning the diversity of products that have been found. Most bioactive compounds from sponges were classified into anti-inflammatory, antitumor, immuno- or neurosurpressive, antiviral, antimalarial, antibiotic, or antifouling. Evaluation of in vitro inhibitory effects of different extracts from four marine sponges versus some antioxidants indices and carbohydrate hydrolyzing enzymes concerned with diabetes mellitus was studied. The chemical characterizations for the extracts of the predominating sponges; SP1 and SP3 were discussed. Methods All chemicals served in the biological study were of analytical grade and purchased from Sigma, Merck and Aldrich. All kits were the products of Biosystems (Spain), Sigma Chemical Company (USA), Biodiagnostic (Egypt). Carbohydrate metabolizing enzymes; α-amylase, α-glucosidase, and β-galactosidase (EC3.2.1.1, EC3.2.1.20, and EC3.2.1.23, respectively) were obtained from Sigma Chemical Company (USA). Results Four marine sponges; Smenospongia (SP1), Callyspongia (SP2), Niphates (SP3), and Stylissa (SP4), were collected from the Red Sea at Egyptian coasts, and taxonomically characterized. The sponges' extracts exhibited diverse inhibitory effects on oxidative stress indices and carbohydrate hydrolyzing enzymes in linear relationships to some extent with concentration of inhibitors (dose dependant). The extracts of sponges (3, 1, and 2) showed, respectively, potent-reducing power. Purification and Chemical characterization of sponge 1 using NMR and mass spectroscopy, recognized the existence of di-isobutyl phthalate (1), di-n-butyl phthalate (2), linoleic acid (3), β-sitosterol (4), and cholesterol (5). Sponge 3 produced bis-[2-ethyl]-hexyl-phthylester (6) and triglyceride fatty acid ester (7). Conclusion Marine sponges are promising sources for delivering of bioactive compounds. Four marine sponges, collected from

  8. Chemical defenses and resource trade-offs structure sponge communities on Caribbean coral reefs

    PubMed Central

    Loh, Tse-Lynn; Pawlik, Joseph R.

    2014-01-01

    Ecological studies have rarely been performed at the community level across a large biogeographic region. Sponges are now the primary habitat-forming organisms on Caribbean coral reefs. Recent species-level investigations have demonstrated that predatory fishes (angelfishes and some parrotfishes) differentially graze sponges that lack chemical defenses, while co-occurring, palatable species heal, grow, reproduce, or recruit at faster rates than defended species. Our prediction, based on resource allocation theory, was that predator removal would result in a greater proportion of palatable species in the sponge community on overfished reefs. We tested this prediction by performing surveys of sponge and fish community composition on reefs having different levels of fishing intensity across the Caribbean. A total of 109 sponge species was recorded from 69 sites, with the 10 most common species comprising 51.0% of sponge cover (3.6–7.7% per species). Nonmetric multidimensional scaling indicated that the species composition of sponge communities depended more on the abundance of sponge-eating fishes than geographic location. Across all sites, multiple-regression analyses revealed that spongivore abundance explained 32.8% of the variation in the proportion of palatable sponges, but when data were limited to geographically adjacent locations with strongly contrasting levels of fishing pressure (Cayman Islands and Jamaica; Curaçao, Bonaire, and Martinique), the adjusted R2 values were much higher (76.5% and 94.6%, respectively). Overfishing of Caribbean coral reefs, particularly by fish trapping, removes sponge predators and is likely to result in greater competition for space between faster-growing palatable sponges and endangered reef-building corals. PMID:24567392

  9. First documentation of tidal-channel sponge biostromes (upper Pleistocene, southeastern Florida)

    USGS Publications Warehouse

    Cunningham, K.J.; Rigby, J.K.; Wacker, M.A.; Curran, H.A.

    2007-01-01

    Sponges are not a common principal component of Cenozoic reefs and are more typically dominant in deep-water and/or cold-water localities. Here we report the discovery of extensive upper Pleistocene shallow-marine, tropical sponge biostromes from the Mami Limestone of southeastern Florida built by a new ceractinomorph demosponge. These upright, barrel- to vase-shaped sponges occur in monospecific aggregations constructed within the tidal channels of an oolitic tidal-bar belt similar to modern examples on the Great Bahama Bank. The biostromes appear to have a ribbon-like geometry, with densely spaced sponges populating a paleochannel along a 3.5 km extent in the most lengthy biostrome. These are very large (as high as 2 m and 1.8 m in diameter), particularly well-preserved calcified sponges with walls as hard as concrete. Quartz grains are the most common particles agglutinated in the structure of the sponge walls. Where exposed, sediment fill between the sponges is commonly a highly burrowed or cross-bedded ooid-bearing grainstone and, locally, quartz sand. It is postulated that the dense, localized distribution of these particular sponges was due to a slight edge over competitors for food or energy supply and space in a stressed environment of tidal-influenced salinity and nutrient changes, strong currents, and frequently shifting submarine sand dunes. To our knowledge, this represents the first documentation of sponge biostromes composed of very large upright sponges within high-energy tidal channels between ooid shoals. The remarkably well-preserved accumulations provide an alternative example of sponge reefs for comparative paleoenvironmental studies. ?? 2007 The Geological Society of America.

  10. Chemical defenses and resource trade-offs structure sponge communities on Caribbean coral reefs.

    PubMed

    Loh, Tse-Lynn; Pawlik, Joseph R

    2014-03-18

    Ecological studies have rarely been performed at the community level across a large biogeographic region. Sponges are now the primary habitat-forming organisms on Caribbean coral reefs. Recent species-level investigations have demonstrated that predatory fishes (angelfishes and some parrotfishes) differentially graze sponges that lack chemical defenses, while co-occurring, palatable species heal, grow, reproduce, or recruit at faster rates than defended species. Our prediction, based on resource allocation theory, was that predator removal would result in a greater proportion of palatable species in the sponge community on overfished reefs. We tested this prediction by performing surveys of sponge and fish community composition on reefs having different levels of fishing intensity across the Caribbean. A total of 109 sponge species was recorded from 69 sites, with the 10 most common species comprising 51.0% of sponge cover (3.6-7.7% per species). Nonmetric multidimensional scaling indicated that the species composition of sponge communities depended more on the abundance of sponge-eating fishes than geographic location. Across all sites, multiple-regression analyses revealed that spongivore abundance explained 32.8% of the variation in the proportion of palatable sponges, but when data were limited to geographically adjacent locations with strongly contrasting levels of fishing pressure (Cayman Islands and Jamaica; Curaçao, Bonaire, and Martinique), the adjusted R(2) values were much higher (76.5% and 94.6%, respectively). Overfishing of Caribbean coral reefs, particularly by fish trapping, removes sponge predators and is likely to result in greater competition for space between faster-growing palatable sponges and endangered reef-building corals. PMID:24567392

  11. Indirect effects of overfishing on Caribbean reefs: sponges overgrow reef-building corals.

    PubMed

    Loh, Tse-Lynn; McMurray, Steven E; Henkel, Timothy P; Vicente, Jan; Pawlik, Joseph R

    2015-01-01

    Consumer-mediated indirect effects at the community level are difficult to demonstrate empirically. Here, we show an explicit indirect effect of overfishing on competition between sponges and reef-building corals from surveys of 69 sites across the Caribbean. Leveraging the large-scale, long-term removal of sponge predators, we selected overfished sites where intensive methods, primarily fish-trapping, have been employed for decades or more, and compared them to sites in remote or marine protected areas (MPAs) with variable levels of enforcement. Sponge-eating fishes (angelfishes and parrotfishes) were counted at each site, and the benthos surveyed, with coral colonies scored for interaction with sponges. Overfished sites had >3 fold more overgrowth of corals by sponges, and mean coral contact with sponges was 25.6%, compared with 12.0% at less-fished sites. Greater contact with corals by sponges at overfished sites was mostly by sponge species palatable to sponge predators. Palatable species have faster rates of growth or reproduction than defended sponge species, which instead make metabolically expensive chemical defenses. These results validate the top-down conceptual model of sponge community ecology for Caribbean reefs, as well as provide an unambiguous justification for MPAs to protect threatened reef-building corals. An unanticipated outcome of the benthic survey component of this study was that overfished sites had lower mean macroalgal cover (23.1% vs. 38.1% for less-fished sites), a result that is contrary to prevailing assumptions about seaweed control by herbivorous fishes. Because we did not quantify herbivores for this study, we interpret this result with caution, but suggest that additional large-scale studies comparing intensively overfished and MPA sites are warranted to examine the relative impacts of herbivorous fishes and urchins on Caribbean reefs. PMID:25945305

  12. Indirect effects of overfishing on Caribbean reefs: sponges overgrow reef-building corals

    PubMed Central

    Loh, Tse-Lynn; McMurray, Steven E.; Henkel, Timothy P.; Vicente, Jan

    2015-01-01

    Consumer-mediated indirect effects at the community level are difficult to demonstrate empirically. Here, we show an explicit indirect effect of overfishing on competition between sponges and reef-building corals from surveys of 69 sites across the Caribbean. Leveraging the large-scale, long-term removal of sponge predators, we selected overfished sites where intensive methods, primarily fish-trapping, have been employed for decades or more, and compared them to sites in remote or marine protected areas (MPAs) with variable levels of enforcement. Sponge-eating fishes (angelfishes and parrotfishes) were counted at each site, and the benthos surveyed, with coral colonies scored for interaction with sponges. Overfished sites had >3 fold more overgrowth of corals by sponges, and mean coral contact with sponges was 25.6%, compared with 12.0% at less-fished sites. Greater contact with corals by sponges at overfished sites was mostly by sponge species palatable to sponge predators. Palatable species have faster rates of growth or reproduction than defended sponge species, which instead make metabolically expensive chemical defenses. These results validate the top-down conceptual model of sponge community ecology for Caribbean reefs, as well as provide an unambiguous justification for MPAs to protect threatened reef-building corals. An unanticipated outcome of the benthic survey component of this study was that overfished sites had lower mean macroalgal cover (23.1% vs. 38.1% for less-fished sites), a result that is contrary to prevailing assumptions about seaweed control by herbivorous fishes. Because we did not quantify herbivores for this study, we interpret this result with caution, but suggest that additional large-scale studies comparing intensively overfished and MPA sites are warranted to examine the relative impacts of herbivorous fishes and urchins on Caribbean reefs. PMID:25945305

  13. Damage tolerant light absorbing material

    DOEpatents

    Lauf, R.J.; Hamby, C. Jr.; Akerman, M.A.; Seals, R.D.

    1993-09-07

    A light absorbing article comprised of a composite of carbon-bonded carbon fibers, is prepared by: blending carbon fibers with a carbonizable organic powder to form a mixture; dispersing the mixture into an aqueous slurry; vacuum molding the aqueous slurry to form a green article; drying and curing the green article to form a cured article; and, carbonizing the cured article at a temperature of at least about 1000 C to form a carbon-bonded carbon fiber light absorbing composite article having a bulk density less than 1 g/cm[sup 3]. 9 figures.

  14. Damage tolerant light absorbing material

    DOEpatents

    Lauf, Robert J.; Hamby, Jr., Clyde; Akerman, M. Alfred; Seals, Roland D.

    1993-01-01

    A light absorbing article comprised of a composite of carbon-bonded carbon fibers, prepared by: blending carbon fibers with a carbonizable organic powder to form a mixture; dispersing the mixture into an aqueous slurry; vacuum molding the aqueous slurry to form a green article; drying and curing the green article to form a cured article; and, carbonizing the cured article at a temperature of at least about 1000.degree. C. to form a carbon-bonded carbon fiber light absorbing composite article having a bulk density less than 1 g/cm.sup.3.

  15. Adaptive inertial shock-absorber

    NASA Astrophysics Data System (ADS)

    Faraj, Rami; Holnicki-Szulc, Jan; Knap, Lech; Seńko, Jarosław

    2016-03-01

    This paper introduces and discusses a new concept of impact absorption by means of impact energy management and storage in dedicated rotating inertial discs. The effectiveness of the concept is demonstrated in a selected case-study involving spinning management, a recently developed novel impact-absorber. A specific control technique performed on this device is demonstrated to be the main source of significant improvement in the overall efficiency of impact damping process. The influence of various parameters on the performance of the shock-absorber is investigated. Design and manufacturing challenges and directions of further research are formulated.

  16. Multi-scale mechanical characterization of highly swollen photo-activated collagen hydrogels.

    PubMed

    Tronci, Giuseppe; Grant, Colin A; Thomson, Neil H; Russell, Stephen J; Wood, David J

    2015-01-01

    Biological hydrogels have been increasingly sought after as wound dressings or scaffolds for regenerative medicine, owing to their inherent biofunctionality in biological environments. Especially in moist wound healing, the ideal material should absorb large amounts of wound exudate while remaining mechanically competent in situ. Despite their large hydration, however, current biological hydrogels still leave much to be desired in terms of mechanical properties in physiological conditions. To address this challenge, a multi-scale approach is presented for the synthetic design of cyto-compatible collagen hydrogels with tunable mechanical properties (from the nano- up to the macro-scale), uniquely high swelling ratios and retained (more than 70%) triple helical features. Type I collagen was covalently functionalized with three different monomers, i.e. 4-vinylbenzyl chloride, glycidyl methacrylate and methacrylic anhydride, respectively. Backbone rigidity, hydrogen-bonding capability and degree of functionalization (F: 16 ± 12-91 ± 7 mol%) of introduced moieties governed the structure-property relationships in resulting collagen networks, so that the swelling ratio (SR: 707 ± 51-1996 ± 182 wt%), bulk compressive modulus (Ec: 30 ± 7-168 ± 40 kPa) and atomic force microscopy elastic modulus (EAFM: 16 ± 2-387 ± 66 kPa) were readily adjusted. Because of their remarkably high swelling and mechanical properties, these tunable collagen hydrogels may be further exploited for the design of advanced dressings for chronic wound care. PMID:25411409

  17. Multi-scale mechanical characterization of highly swollen photo-activated collagen hydrogels

    PubMed Central

    Tronci, Giuseppe; Grant, Colin A.; Thomson, Neil H.; Russell, Stephen J.; Wood, David J.

    2015-01-01

    Biological hydrogels have been increasingly sought after as wound dressings or scaffolds for regenerative medicine, owing to their inherent biofunctionality in biological environments. Especially in moist wound healing, the ideal material should absorb large amounts of wound exudate while remaining mechanically competent in situ. Despite their large hydration, however, current biological hydrogels still leave much to be desired in terms of mechanical properties in physiological conditions. To address this challenge, a multi-scale approach is presented for the synthetic design of cyto-compatible collagen hydrogels with tunable mechanical properties (from the nano- up to the macro-scale), uniquely high swelling ratios and retained (more than 70%) triple helical features. Type I collagen was covalently functionalized with three different monomers, i.e. 4-vinylbenzyl chloride, glycidyl methacrylate and methacrylic anhydride, respectively. Backbone rigidity, hydrogen-bonding capability and degree of functionalization (F: 16 ± 12–91 ± 7 mol%) of introduced moieties governed the structure–property relationships in resulting collagen networks, so that the swelling ratio (SR: 707 ± 51–1996 ± 182 wt%), bulk compressive modulus (Ec: 30 ± 7–168 ± 40 kPa) and atomic force microscopy elastic modulus (EAFM: 16 ± 2–387 ± 66 kPa) were readily adjusted. Because of their remarkably high swelling and mechanical properties, these tunable collagen hydrogels may be further exploited for the design of advanced dressings for chronic wound care. PMID:25411409

  18. An insight into the biophysical characterization of insoluble collagen aggregates: implication for arthritis.

    PubMed

    Amani, Samreen; Shamsi, Anas; Rabbani, Gulam; Naim, Aabgeena

    2014-09-01

    Misfolding and aggregation of proteins is involved in some of the most prevalent neurodegenerative disorders. The importance of collagen stems from the fact that it is one of the dominant component used for tissue engineering and drug delivery applications and is a major component of skin, tendon, bone and other connective tissues. A systematic investigation on the conformation of collagen at various concentrations of glyoxal is studied by various biophysical techniques such as Trp fluorescence, ANS binding, Circular dichroism (CD), ATR-FTIR, Congo red (CR) assay, Rayleigh light scattering and Turbidity measurements. At 60% (v/v) glyoxal, collagen retains native-like secondary structure, altered Trp environment and high ANS fluorescence, characteristic of molten globule (MG) state. At 80% (v/v) glyoxal, insoluble collagen aggregates are detected as confirmed by decrease in Trp and ANS fluorescence, increase in non-native β sheet structure as evident from far-UV CD and FTIR spectra, increase in Thioflavin T fluorescence, Rayleigh light scattering, Turbidity measurements, as well as red shift in CR absorbance. PMID:25011697

  19. Supramolecular assembly of collagen fibrils into collagen fiber in fish scales of red seabream, Pagrus major.

    PubMed

    Youn, Hwa Shik; Shin, Tae Joo

    2009-11-01

    Supramolecular assembly of collagen fibrils into collagen fiber and its distribution in fish scales of red seabream, Pagrus major, were investigated. By virtue of Zernike phase-contrast hard X-ray microscopy, it has been firstly observed that collagen fiber consists of helical substructures of collagen fibrils wrapped with incrustation. As it close to the scalar focus (that is, with aging), loosened- and deteriorated-helical assemblies started to be observed with loosing wrapping incrustation, indicative of the distortion of the basic helical assembly. Various distributions and packing arrangements of collagen fibers were observed dependent on subdivisions of fish scale. Freshly growing edge region of fish scale, embedded into fish skin, showed rarely patched and one directionally arranged collagen fibers, in which specifically triple helical assemblies of collagen fibrils were found. On the contrary, relatively aged region of the rostral field close to the scalar focus displayed randomly directed and densely packed collagen fibers, in which loosened- and deteriorated-helical assemblies of collagen fibrils were mostly found. Our results have demonstrated that hard X-ray microscope can be a powerful tool to study in situ internal structure of biological specimens in an atmospheric pressure. PMID:19666125

  20. Harnessing the Versatility of Bacterial Collagen to Improve the Chondrogenic Potential of Porous Collagen Scaffolds.

    PubMed

    Parmar, Paresh A; St-Pierre, Jean-Philippe; Chow, Lesley W; Puetzer, Jennifer L; Stoichevska, Violet; Peng, Yong Y; Werkmeister, Jerome A; Ramshaw, John A M; Stevens, Molly M

    2016-07-01

    Collagen I foams are used in the clinic as scaffolds to promote articular cartilage repair as they provide a bioactive environment for cells with chondrogenic potential. However, collagen I as a base material does not allow for precise control over bioactivity. Alternatively, recombinant bacterial collagens can be used as "blank slate" collagen molecules to offer a versatile platform for incorporation of selected bioactive sequences and fabrication into 3D scaffolds. Here, we show the potential of Streptococcal collagen-like 2 (Scl2) protein foams modified with peptides designed to specifically and noncovalently bind hyaluronic acid and chondroitin sulfate to improve chondrogenesis of human mesenchymal stem cells (hMSCs) compared to collagen I foams. Specific compositions of functionalized Scl2 foams lead to improved chondrogenesis compared to both nonfunctionalized Scl2 and collagen I foams, as indicated by gene expression, extracellular matrix accumulation, and compression moduli. hMSCs cultured in functionalized Scl2 foams exhibit decreased collagens I and X gene and protein expression, suggesting an advantage over collagen I foams in promoting a chondrocytic phenotype. These highly modular foams can be further modified to improve specific aspects chondrogenesis. As such, these scaffolds also have the potential to be tailored for other regenerative medicine applications. PMID:27219220