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Sample records for autogenous bone dust

  1. Bone regeneration in surgically created defects filled with autogenous bone: an epifluorescence microscopy analysis in rats

    OpenAIRE

    Marcos Heidy Guskuma; Eduardo Hochuli-Vieira; Flávia Priscila Pereira; Idelmo Rangel-Garcia Junior; Roberta Okamoto; Tetuo Okamoto; Osvaldo Magro Filho

    2010-01-01

    Although the search for the ideal bone substitute has been the focus of a large number of studies, autogenous bone is still the gold standard for the filling of defects caused by pathologies and traumas, and mainly, for alveolar ridge reconstruction, allowing the titanium implants installation. OBJECTIVES: The aim of this study was to evaluate the dynamics of autogenous bone graft incorporation process to surgically created defects in rat calvaria, using epifluorescence microscopy. MATERIAL A...

  2. Bone healing around nanocrystalline hydroxyapatite, deproteinized bovine bone mineral, biphasic calcium phosphate, and autogenous bone in mandibular bone defects

    DEFF Research Database (Denmark)

    Broggini, Nina; Bosshardt, Dieter D; Jensen, Simon S;

    2015-01-01

    with nanocrystalline hydroxyapatite (HA-SiO), deproteinized bovine bone mineral (DBBM), biphasic calcium phosphate (BCP) with a 60/40% HA/β-TCP (BCP 60/40) ratio, or particulate autogenous bone (A) for histological and histomorphometric analysis. At 2 weeks, percent filler amongst the test groups (DBBM (35.65%), HA...

  3. Histological Observation of Autogenous Bone Dust Grafting and Membrane Guided Regeneration Technology to Repair Skull Defects%自体颅骨粉末移植和膜引导再生技术修复兔颅骨缺损的组织学研究

    Institute of Scientific and Technical Information of China (English)

    陈敏建; 陆婷; 陈平

    2013-01-01

    Objective To repair the skull defects by using autogenous skull bone dust grafting and membrane guided regeneration technology, and to investigate its histological evolution. Methods Fifty New Zealand white rabbits were selected. A whole thick defect with the diameter of 1 cm was created in the parietal bone of every rabbit. The defect was grafted with autogenous skull bone dust and two pieces of absorbable membrane on two side. After 2, 4, 6, 8, 12 weeks, the defects were harvested for histological observation. Results Two weeks after operation, a large number of bone meal was observed in the defect area. Inward infiltration of inflammatory cells, capillaries and fibroblasts were observed. Bone meal was swallowed in the central area, new bone was formed in the surrounding area and a clear boundary was observed between the two area. Four weeks after operation, the boundary had moved a lot to the central area. New woven bone was thickened, the connection between the woven bone became more closely. Tissue and cell components had no obvious change compared with 2 weeks after operation. Six weeks after operation, bone meal was almost absorbed, the woven bone became thicker and the connection was more closely. Eight weeks after operation, no bone dust could be observed, a monolayer new bone was formed in the central area. The woven bone in the surrounding area was relatively thick and closely connected with normal bone. The primary bone marrow cavity was formed. Twelve weeks after operation, double new bone was observed in the central area. New bone remodeling and mature bone marrow cavity were also observed. The morphology and composition of bone marrow cavity had no difference compared with normal bone. Conclusion Histological evolution of autogenous bone dust grafting and membrane guided regeneration technology to repair skull defects is guided and induced bone regeneration.%目的:应用自体颅骨粉末移植和膜引导再生技术修复兔颅骨缺损模型

  4. Reconstruction of mandibular defects with autogenous bone grafts: a review of 30 cases

    International Nuclear Information System (INIS)

    Multitudes of options are available for reconstruction of functional and cosmetic defects of the mandible, caused by various ailments. At the present time, autogenous bone grafting is the gold standard by which all other techniques of reconstruction of the mandible can be judged. The purpose of this study was to evaluate the outcome of different osseous reconstruction options using autogenous bone grafts for mandibular reconstruction. Methods: This Interventional study was conducted at Department of Oral and Maxillofacial Surgery, King Edward Medical University/Mayo Hospital Lahore, from January 2008 to July 2009 including one year follow-up. The study was carried out on thirty patients having bony mandibular defects. They were reconstructed with the autogenous bone grafts from different graft donor sites. On post-operative visits they were evaluated for outcome variables. Results: Success rate of autogenous bone grafts in this study was 90%. Only 10% of the cases showed poor results regarding infection, resorption and graft failure. Conclusion: Autogenous bone grafts, non-vascularized or vascularized, are a reliable treatment modality for the reconstruction of the bony mandibular defects with predictable functional and aesthetic outcome. (author)

  5. Histomorphometric Evaluation of Anorganic Bovine Bone Coverage to Reduce Autogenous Grafts Resorption: Preliminary Results

    OpenAIRE

    C Maiorana; Beretta, M.; G B Grossi; Santoro, F.; A. Scott Herford; Nagursky, H; CICCIÙ, M.

    2011-01-01

    Physiologic resorption due to remodeling processes affects autogenous corticocancellous grafts in the treatment of atrophic jawbone alveolar ridges. Such a situation in the past made overgrafting of the recipient site mandatory to get enough bone support to dental implants in order to perform a prosthetic rehabilitation. Anorganic bovine bone, conventionally used to treat alveolar bone deficiencies in implant surgery, showed a high osteoconductive property thanks to its micro and macrostructu...

  6. Alternative method to treat oroantral communication and fistula with autogenous bone graft and platelet rich firbin

    Science.gov (United States)

    Niedzielska, Iwona; Borgiel-Marek, Halina; Różanowski, Bartosz

    2016-01-01

    Background Removing a tooth from the jaw results in the occurrence of oroantral communication in beneficial anatomic conditions or in the case of a iatrogenic effect. Popularized treatments of the oroantral communication have numerous faults. Large bone defect eliminates the chance to introduce an implant. Purpose of this work was assessment of the usefulness of autogenous bone graft and PRF in normal bone regeneration in the site of oroantral communication. Material and Methods Bone regeneration in the site of oroantral communication was assessed in 20 patients. Bone defects were supplemented autogenous bone graft from mental protuberance in 14 cases and from oblique line in 6 cases. The graft was covered with a PRF membrane. Results In the study group in all cases closure of the oroantral communication was observed. The average width of the alveolar was 13 mm and the average height was 12.5 mm. In 3 patients an average increase of alveolar height of 1.5 mm was observed. Conclusions This method may be the best option to prepare alveolar for new implant and prosthetic solutions. Key words:Oroantral communication, oroantral fistula, autogenous bone graft, bone regeneration, platelet rich fibrin. PMID:27475687

  7. Simultaneous implant placement with ridge augmentation using an autogenous bone ring transplant.

    Science.gov (United States)

    Omara, M; Abdelwahed, N; Ahmed, M; Hindy, M

    2016-04-01

    The severely defective socket, in which implant placement within the remaining bone will result in a significantly off-axis implant position, precludes immediate implant placement and requires bone grafting as an initial surgical intervention. The aims of this study were to evaluate autogenous chin bone ring consolidation after the augmentation of severely defective sockets and the clinical application of these rings in the premolar-molar region with simultaneous implant placement in a one-stage procedure. Ten patients with 12 defective sockets were included. Sockets were prepared with a trephine bur. Bone rings with a tapped implant osteotomy were harvested from the chin with a larger trephine bur. Bone rings were fitted in the prepared sockets. An implant drill was used to prepare the bone apical to the ring through its central osteotomy. Implants were screwed through the rings and the apical bone. Patients were examined clinically and radiographically immediately and at 6 months postoperative. Crestal bone changes were measured and evaluated statistically. All grafted sockets showed bone healing with no significant crestal bone resorption and no infection; only one ring showed dehiscence, which healed during the follow-up period. All implants showed radiographic evidence of osseointegration. The autogenous chin bone ring augmentation technique was found to be a reliable alternative method for the management of severely defective sockets. PMID:26644216

  8. Autogenous bone graft and ePTFE membrane in the treatment of peri-implantitis. II. Stereologic and histologic observations in cynomolgus monkeys

    DEFF Research Database (Denmark)

    Schou, Søren; Holmstrup, Palle; Skovgaard, Lene Theil; Stoltze, K.; Hjørting-Hansen, Erik; Gundersen, Hans Jørgen G.

    autogenous bone graft; guided bone regeneration; histology; membrane; non-human primates; oral implants; osseointegration; pathalogy; peri-implantitis; stereology; treatment......autogenous bone graft; guided bone regeneration; histology; membrane; non-human primates; oral implants; osseointegration; pathalogy; peri-implantitis; stereology; treatment...

  9. Evaluation of ABM/P-15 versus autogenous bone in an ovine lumbar interbody fusion model

    OpenAIRE

    Sherman, Blake P.; Lindley, Emily M.; Turner, A. Simon; Seim III, Howard B.; Benedict, James; Burger, Evalina L; Patel, Vikas V.

    2010-01-01

    A prospective, randomized study was performed in an ovine model to compare the efficacy of an anorganic bovine-derived hydroxyapatite matrix combined with a synthetic 15 amino acid residue (ABM/P-15) in facilitating lumbar interbody fusion when compared with autogenous bone harvested from the iliac crest. P-15 is a biomimetic to the cell-binding site of Type-I collagen for bone-forming cells. When combined with ABM, it creates the necessary scaffold to initiate cell invasion, binding, and sub...

  10. Histological evaluation of healing after transalveolar maxillary sinus augmentation with bioglass and autogenous bone

    DEFF Research Database (Denmark)

    Stavropoulos, Andreas; Sima, Catalin; Sima, Andrea; Nyengaard, Jens; Karring, Thorkild; Sculean, Anton

    2012-01-01

    OBJECTIVES: The aim was to evaluate histologically the outcome of a bioglass and autogenous bone (at 1 : 1 ratio) composite implantation for transalveolar sinus augmentation. METHODS: In 31 patients, during implant installation ca. 4 months after sinus augmentation, biopsies were harvested through...... inside the sinus and the transalveolar osteotomy, respectively, qualified for analysis. The tissue fractions occupied by newly formed bone (mineralized tissue+bone marrow), soft connective tissue, residual biomaterial+empty spaces, and debris inside the sinus cavity or the transalveolar osteotomy were...... estimated. RESULTS: Bone and connective tissue fraction in the newly formed tissues inside the sinus cavity averaged 23.4 ± 13.2% and 54.1 ± 23.5%, respectively. Residual biomaterial, empty spaces, and debris averaged 1.9 ± 3.5%, 10.5 ± 6.3%, and 8.4 ± 14.5%, respectively. In the transalveolar osteotomy...

  11. Results of autogenous trephine biopsy needle bone grafting in fractures of radius and ulna.

    Science.gov (United States)

    Lakhey, S; Shrestha, B P; Pradhan, R L; Pandey, B; Rijal, K P

    2005-01-01

    Cortico-Cancellous bone graft harvested from the anterior iliac crest by the conventional open method is associated with more morbidity and is more time consuming as compared to the percutaneous method using trephine biopsy needle. The aim of the study was to determine whether cancellous bone graft harvested from anterior iliac crest using trephine biopsy needle consistently achieved bone union in comminuted fractures and fractures of more than 3 weeks duration of radius and ulna and also to determine the morbidity at the donor site. Autogenous cancellous bone graft was harvested percutaneously from 28 iliac crests in 16 patients and applied at fracture sites of 30 forearm bones using a 4mm trephine biopsy needle after the fractures had been fixed with plate and screws. The patients were followed up regularly upto 6 to 9 months post - operatively in the OPD to determine the union status of the fractured bones and the morbidity at the donor site. 29 of the 30 fractures of the forearm bones united without any problems. The shaft of a trephine got bent during the harvesting procedure at the beginning of the study due to improper technique. Cancellous bone graft harvested from the anterior iliac crest results in predictable good union results in comminuted fractures of forearm bones and also fractures presenting after 3 weeks of injury. It is also an easier and quicker way of harvesting bone graft and is associated with lesser morbidity and earlier recovery as compared to conventional open method. PMID:16554860

  12. Histological evaluation of the influence of magnetic field application in autogenous bone grafts in rats

    Directory of Open Access Journals (Sweden)

    Ponzoni Deise

    2009-01-01

    Full Text Available Abstract Background Bone grafts are widely used in oral and maxillofacial reconstruction. The influence of electromagnetic fields and magnets on the endogenous stimulation of target tissues has been investigated. This work aimed to assess the quality of bone healing in surgical cavities filled with autogenous bone grafts, under the influence of a permanent magnetic field produced by in vivo buried devices. Methods Metal devices consisting of commercially pure martensitic stainless steel washers and titanium screws were employed. Thirty male Wistar rats were divided into 3 experimental and 3 control groups. A surgical bone cavity was produced on the right femur, and a bone graft was collected and placed in each hole. Two metallic washers, magnetized in the experimental group but not in the control group, were attached on the borders of the cavity. Results The animals were sacrificed on postoperative days 15, 45 and 60. The histological analysis of control and experimental samples showed adequate integration of the bone grafts, with intense bone neoformation. On days 45 and 60, a continued influence of the magnetic field on the surgical cavity and on the bone graft was observed in samples from the experimental group. Conclusion The results showed intense bone neoformation in the experimental group as compared to control animals. The intense extra-cortical bone neoformation observed suggests that the osteoconductor condition of the graft may be more susceptible to stimulation, when submitted to a magnetic field.

  13. Autogenous iliac crest bone graft versus banked allograft bone in scoliosis surgery in patients with Duchenne muscular dystrophy

    OpenAIRE

    Nakazawa, Toshiyuki; Takaso, Masashi; Imura, Takayuki; Adachi, Kou; Fukushima, Kensuke; Saito, Wataru; Miyajima, Gennyo; Minatani, Atsushi; Shinntani, Ryousuke; Itoman, Moritoshi; Takahashi, Kazuhisa; Yamazaki, Masashi; Ohtori, Seiji; Sasaki, Atsushi

    2009-01-01

    A total of 36 consecutive nonambulatory DMD patients underwent scoliosis surgery. Patients were divided into two groups: the autogenous iliac crest bone graft group (the ICBG group; 20 patients) and the allogenous bone graft group (the ALBG group; 16 patients). The mean preoperative curves measured 87° and 31° at the last follow-up in the ICBG group and 83° and 28° in the ALBG group. In the ICBG group, three (15%) patients had intraoperative sacroiliac joint penetration, five (25%) had iliac ...

  14. Effects of low-level laser therapy on autogenous bone graft stabilized with a new heterologous fibrin sealant.

    Science.gov (United States)

    de Oliveira Gonçalves, Jéssica Barbosa; Buchaim, Daniela Vieira; de Souza Bueno, Cleuber Rodrigo; Pomini, Karina Torres; Barraviera, Benedito; Júnior, Rui Seabra Ferreira; Andreo, Jesus Carlos; de Castro Rodrigues, Antonio; Cestari, Tania Mary; Buchaim, Rogério Leone

    2016-09-01

    Autogenous bone grafts are used to repair bone defects, and the stabilization is needed for bone regeneration. Laser photobiomodulation is a modality of treatment in clinical practice for tissue regeneration, and it has therapeutic effects as an anti-inflammatory, analgesic and modulating cellular activity. The aim of the present study was to evaluate the effects of low-level laser therapy (LLLT) on an autogenous bone graft integration process stabilized with a new heterologous fibrin sealant. Forty rats were divided into two groups: Autogenous Fibrin Graft (AFG, n=20), in which a 5mm dome osteotomy was conducted in the right parietal bone and the graft was adhered to the left side using fibrin sealant; and Autogenous Fibrin Graft Laser (AFGL, n=20), which was subjected to the same procedures as AFG with the addition of LLLT. The treatment was performed immediately following surgery and then three times a week until euthanasia, using an 830nm laser (30mW, 6J/cm(2), 0.116cm(2), 258.6mW/cm(2), 2.9J). Five animals from each group were euthanized at 10, 20, 30 and 40days postoperative, and the samples were submitted to histomorphological and histomorphometric analysis. Partial bone regeneration occurred, with new bone tissue integrating the graft to the recipient bed and small areas of connective tissue. Comparative analysis of the groups at the same intervals revealed minor interfaces in group AFGL, with statistically significant differences (p<0.05) at all of the analyzed intervals (10days p=0.0087, 20days p=0.0012, 30days p<0.0001, 40days p=0.0142). In conclusion, low-level laser therapy stimulated bone regeneration and accelerated the process of integration of autogenous bone grafts. PMID:27497370

  15. Instrumented fusion of thoracolumbar fracture with type I mineralized collagen matrix combined with autogenous bone marrow as a bone graft substitute: a four-case report

    OpenAIRE

    Faundez, Antonio; Taylor, Sofia; Kaelin, André

    2006-01-01

    In order to avoid the morbidity from autogenous bone harvesting, bone graft substitutes are being used more frequently in spinal surgery. There is indirect radiological evidence that bone graft substitutes are efficacious in humans. The purpose of this four-case study was to visually, manually, and histologically assess the quality of a fusion mass produced by a collagen hydroxyapatite scaffold impregnated with autologous bone marrow aspirate for posterolateral fusion. Four patients sustained...

  16. Maxillary sinus floor augmentation with Bio-Oss or Bio-Oss mixed with autogenous bone as graft in animals

    DEFF Research Database (Denmark)

    Jensen, T; Schou, S; Stavropoulos, Andreas;

    2012-01-01

    The objective of the present systematic review was to test the hypothesis of no differences between the use of Bio-Oss or Bio-Oss mixed with autogenous bone as graft for maxillary sinus floor augmentation (MSFA) applying the lateral window technique, as evaluated in animals. A MEDLINE (Pub...... graft improved significantly with increased proportion of Bio-Oss. Bone regeneration, bone-to-implant contact (BIC), biomechanical implant test values, and biodegradation of Bio-Oss after MSFA with Bio-Oss or Bio-Oss mixed with autogenous bone have never been compared within the same study in animals......Med), Embase, and Cochrane Library search in combination with a hand-search of relevant journals was conducted by including animal studies published in English from 1 January 1990 to 1 June 2010. The search provided 879 titles and 14 studies fulfilled the inclusion criteria. The volumetric stability of the...

  17. Allogeneic and autogenous transplantations of MSCs in treatment of the physeal bone bridge in rabbits

    Directory of Open Access Journals (Sweden)

    Urbanova Lucie

    2008-09-01

    Full Text Available Abstract Background The aim of this experimental study on New Zealand's white rabbits was to find differences in the results of treating the distal physeal femoral defect by the transplantation of autologous or allogeneic mesenchymal stem cells (MSCs. After the excision of a created bone bridge in the distal physis of the right femur, modified composite scaffold with MSCs was transplanted into the defect. In animal Group A (n = 11 autogenous MSCs were implanted; in animal Group B (n = 15 allogeneic MSCs were implanted. An iatrogenic physeal defect of the left femur of each animal not treated by MSCs transplantation served as control. The rabbits were euthanized four months after the transplantation. The treatment results were evaluated morphometrically (femoral length and valgus deformity measurement and histologically (character and quality of the new cartilage. Results Four months after the transplantation, the right femurs of the animals in Group A were on average longer by 0.50 ± 0.04 cm (p = 0.018 than their left femurs, the right femurs of rabbits in Group B were on average longer by 0.43 ± 0.01 cm (p = 0.028 than their left femurs. 4 months after the therapeutic transplantation of MSCs valgus deformity of the distal part of the right femur of animals in Group A was significantly lower (by 4.45 ± 1.86° than that of their left femur (p = 0.028, in Group B as well (by 3.66 ± 0.95° than that of their left femur p = 0.001. However, no significant difference was found between rabbits with transplanted autogenous MSCs (Group A and rabbits with transplanted allogeneic MSCs (Group B either in the femur length (p = 0.495, or in its valgus deformity (p = 0.1597. After the MSCs transplantation the presence of a newly formed hyaline cartilage was demonstrated histologically in all the animals (both groups. The ability of transplanted MSCs to survive in the damaged physis was demonstrated in vivo by magnetic resonance, in vitro by Perls reaction

  18. Exchanging reamed nailing versus augmentative compression plating with autogenous bone grafting for aseptic femoral shaft nonunion: a retrospective cohort study

    OpenAIRE

    Jiang-ying, Ru; Yun-fei, Niu; Yu, Cong; Wen-bo, Kang; Hai-bin, Cang; Jian-ning, Zhao

    2015-01-01

    Objective: The purpose of this study was to compare the outcomes of exchanging reamed nailing (ERN) and augmentative compression plating (ACP) with autogenous bone grafting (BG) for the treatment of aseptic femoral shaft nonunion secondary to the treatment of intramedullary nailing (IMN).Methods: A multicenter retrospective study was performed for 178 patients (180 cases) of aseptic femoral shaft nonunion secondary to first treatment of IMN. All cases were fixed with either ERN (n=87) or ACP ...

  19. Evaluation of the role of autogenous bone-marrow-derived mesenchymal stem cell transplantation for the repair of mandibular bone defects in rabbits.

    Science.gov (United States)

    Saad, Khaled Abd-Elhamid; Abu-Shahba, Ahmed Gamal Taha; El-Drieny, Ezzat Abd-Elaziz; Khedr, Mohamed Saad

    2015-09-01

    The repair of craniofacial bony defects by traditional grafting techniques requires substantial time and effort, with associated morbidity. Tissue engineering has therefore become a novel approach targeting application for bone regeneration. This study used the rabbit model for radiographic and histological evaluation of bone bioengineering for mandibular defects reconstruction using only β-tricalcium phosphate (β-TCP) and, when loaded with autogenous; bone marrow-derived undifferentiated mesenchymal stem cells (BM-MSCs). Critical-sized defects (10 × 15 mm) were created unilaterally in the mandibular body region of each rabbit (n = 16), to be filled with the BM-MSCs/β-TCP constructs for the study group (group I) (n1 = 8) and with scaffold devoid of cells for the control group (group II) (n2 = 8). Two rabbits from each group were sacrificed after healing periods of 2, 4, 12, and 24 weeks. The results revealed that the BM-MSCs endowed β-TCP scaffold with a better and more rapid bone regenerating potential: since the first evaluation period of 2 weeks, the regenerated bone tissue in group I was more mature, denser and homogeneously distributed. From these findings we could infer that the bone regeneration process was jump-started within the study group cases, which led to better quality of regenerated bone. PMID:26048107

  20. Biomechanical studies of vertebroplasty by autogenous bone grafting%自体骨椎体成形术的生物力学研究

    Institute of Scientific and Technical Information of China (English)

    王骅; 王静成; 王永祥

    2013-01-01

    Objective To study the biomechanical effects on the injury lumbar spine with vertebroplasty by autogenous bone grafting. Methods Nine cadaver lumbar spine specimens were randomly divided into 3 groups: normal group, fracture group, and fracture with vertebroplasty by autogenous bone grafting group. Data of the rigidity and stress were recorded and analyzed. Result Vertebroplasty by autogenous bone grafting improved stability of the fracture segment obviously (P<0.05), but it was still more instable than normal segment (P<0.05). Conclusion Vertebroplasty by autogenous bone grafting can provide stability partly, but it should be applied combined with internal fixation.%目的 探讨自体骨椎体成形术对损伤腰椎生物力学特性的影响.方法 9具尸体腰椎标本分为正常组、椎体压缩骨折组、自体骨椎体成形术组,分别进行生物力学测试,探讨损伤腰椎力学特性的变化.结果 自体骨椎体成形术能改善损伤腰椎的稳定性,但与正常椎体相比尚有差距,呈显著性差异(P<0.05).结论 自体骨椎体成形术部分改善了损伤腰椎的生物力学稳定性,应与内固定系统联合运用.

  1. Clinical Comparison of Autogenous Bone Graft with and without Plasma Rich in Growth Factors in the Treatment of Grade II Furcation Involvement of Mandibular Molars

    OpenAIRE

    Lafzi, Ardeshir; Shirmohammadi, Adileh; Faramarzi, Masoumeh; Jabali, Sahar; Shayan, Arman

    2013-01-01

    Background and aims Plasma rich in growth factors (PRGF) is a concentrated suspension of growth factors, which is used to promote periodontal tissue regeneration. The aim of this randomized, controlled, clinical trial was to evaluate of the treatment of grade II mandibular molar furcation involvement using autogenous bone graft with and without PRGF. Materials and methods In this double-blind clinical trial, thirty mandibular molars with grade II furcation involvement in 30 patients were sele...

  2. Correlation between Density and Resorption of Fresh-Frozen and Autogenous Bone Grafts

    OpenAIRE

    2014-01-01

    Trial Design. This analysis compared the outcome of fresh-frozen versus autologous bone block grafts for horizontal ridge augmentation in patients with Cawood and Howell class IV atrophies. Methods. Seventeen patients received autologous grafts and 21 patients received fresh-frozen bone grafts. Patients underwent CT scans 1 week and 6 months after surgery for graft volume and density analysis. Results. Two autologous and 3 fresh-frozen grafts failed. Autologous and fresh-frozen grafts lost, r...

  3. Lateral Ridge Augmentation with Autogenous Bone Harvested Using Trephine Drills: A Noninvasive Technique

    Science.gov (United States)

    Arab, H. R.; Moeintaghavi, A.; Taheri, M.; Sargolzaie, N.; Aghasizadeh, D.; Shiezadeh, F.

    2016-01-01

    Purpose: The aim of this pilot study was to evaluate the success rate of a chairside ridge augmentation procedure using bone autografts harvested with trephine drills and placed without the use of screws. Methods: Thirty patients were recruited for the study. After the surgical site was anesthetized and a crestal incision was made, an envelope flap was retracted using blunt dissection limited to the graft site, and the periosteum was raised intact and undamaged from the bone. The flap was extended laterally to obtain sufficient space for the bone graft. At the donor site, bone was obtained from the external oblique ridge area. A #5 or #6 trephine drill was used to harvest one or two pieces of bone. The bone blocks were placed inside the envelope flap at the recipient site, which was then sutured and covered with periodontal dressing. Antibiotics, analgesics, and mouthwash were prescribed. Measurements of ridge width were performed using CBCT before and 3 months after surgery. The pre- and post operative results were compared using paired t test. Results: Pre- and post-operative mean ridge widths were 2.23 ± 0.79 and 5.16 ± 0.68 mm, respectively. The mean increase in width was 2.92 ± 0.89 mm(P < 0.001). Conclusion: This non-invasive and simple technique provided an acceptable increase in ridge width. As the sample was small, we recommend further clinical investigation with larger samples to confirm that this technique may be used successfully as an alternative to current invasive augmentation methods. PMID:27006718

  4. Reconstruction of Mandibular Defects Using Nonvascularized Autogenous Bone Graft in Nigerians

    OpenAIRE

    Kizito Chioma Ndukwe; Stephen Babatunde Aregbesola; Innocent Chinedu Ikem; Ugboko, Vincent I; Kehinde Emmanuel Adebiyi; Olawunmi Adedoyin Fatusi; Foluso John Owotade; Ramat Oyebunmi Braimah

    2014-01-01

    Objectives: The aim of this study is to evaluate the success rate and complications of mandibular reconstruction with nonvascularized bone graft in Ile-Ife, Nigeria. Patients and Methods: A total of 25 patients who underwent reconstruction of mandibular discontinuity defects between January 2003 and February 2012, at the Obafemi Awolowo University Teaching Hospitals Complex, Ile-Ife constituted the study sample. Relevant information was retrieved from the patients′ records. This information i...

  5. Comparison of autogenous bone graft donor site haemostatic agents used in spinal surgery

    OpenAIRE

    Copuroglu, Cem; Ercan, Selcuk; Ozcan, Mert; Ciftdemir, Mert; Turan, F. Nesrin; Yalniz, Erol

    2011-01-01

    Objective: The aim of our study was to investigate the effects of haemostatic agents used at the autograft donor sites in spinal fusion. Methods: The study included 66 patients (26 men, 40 women; mean age: 42.9 years) who underwent spinal fusion surgery between March 1999 and October 2002. Patients were randomly assigned to 4 different groups according to the haemostatic agents used during surgery. In Group 1, bone wax was used on the graft donor site. In Group 2, spongostan was used. In ...

  6. Reconstruction of mandibular defects using nonvascularized autogenous bone graft in Nigerians

    Directory of Open Access Journals (Sweden)

    Kizito Chioma Ndukwe

    2014-01-01

    Full Text Available Objectives: The aim of this study is to evaluate the success rate and complications of mandibular reconstruction with nonvascularized bone graft in Ile-Ife, Nigeria. Patients and Methods: A total of 25 patients who underwent reconstruction of mandibular discontinuity defects between January 2003 and February 2012, at the Obafemi Awolowo University Teaching Hospitals Complex, Ile-Ife constituted the study sample. Relevant information was retrieved from the patients′ records. This information include patients′ demographics (age and sex as well as the type of mandibular defect, cause of the defect, type of mandibular resection done, source of the bone graft used, and the method of graft immobilization. Morbidity associated with the graft procedures were assessed by retrieving information on graft failures, length of hospital stay following surgery, rehabilitation device used and associated graft donor and recipient site complications. Result: There were 12 males and 13 females with a male:female ratio was 1:1.1. The age of the patients ranged from 13 to 73 years with a mean age for males 32.7 ± standard deviation (SD 12.9 and for females 35.0 ± SD 17.1. Jaw defect was caused by resection for tumours and other jaw pathologies in 92% of cases. Complete symphyseal involvement defect was the most common defect recorded 11 (44%. Reconstruction with nonvascularized rib graft accounted for 68% of cases while iliac crest graft was used in 32% of the patients. Successful take of the grafts was recorded in 22 patients while three cases failed. Wound dehiscence (two patients and postoperative wound infection (eight patients were the most common complications recorded. Conclusion: The use of nonvascularized graft is still relevant in the reconstruction of large mandibular defects caused by surgical ablation of benign conditions in Nigerians. Precise surgical planning and execution, extended antibiotic therapy, and meticulous postoperative care

  7. Clinical Comparison of Autogenous Bone Graft with and without Plasma Rich in Growth Factors in the Treatment of Grade II Furcation Involvement of Mandibular Molars

    Science.gov (United States)

    Lafzi, Ardeshir; Shirmohammadi, Adileh; Faramarzi, Masoumeh; Jabali, Sahar; Shayan, Arman

    2013-01-01

    Background and aims Plasma rich in growth factors (PRGF) is a concentrated suspension of growth factors, which is used to promote periodontal tissue regeneration. The aim of this randomized, controlled, clinical trial was to evaluate of the treatment of grade II mandibular molar furcation involvement using autogenous bone graft with and without PRGF. Materials and methods In this double-blind clinical trial, thirty mandibular molars with grade II furcation involvement in 30 patients were selected. The test group received bone graft combined with PRGF, while the control group was treated with bone graft only. Clinical parameters included clinical probing depth (CPD), vertical clinical attachment level (V-CAL), horizontal clinical attachment level (H-CAL), location of gingival margin (LGM), surgically exposed horizontal probing depth of bony defect (E-HPD), vertical depth of bone crest (V-DBC), vertical depth of the base of bony defect (V-DBD), and length of the intrabony defect (LID). After six months, a re-entry surgery was performed. Data were analyzed by SPSS 14, using Kolmogorov, Mann-Whitney U, and paired t-test. Results After 6 months, both treatment methods led to significant improvement in V-CAL and H-CAL and significant decreases in CPD, E-HPD, V-DBD and LID; there was no significant difference in LGM and V-DBC in any of the treated groups compared to the baseline values. Also, none of the parameters showed significant differences between the study groups. Conclusion Although autogenous bone grafts, with or without PRGF, were successful in treating grade II furcation involvement, no differences between the study groups were observed. PMID:23486928

  8. 浓缩自体骨髓移植配合中药治疗骨不连临床研究%Effect of Concentrated Autogenous Bone Marrow Stem Cell Transplant Combined with Traditional Chinese Medicine on Bone Nonunion

    Institute of Scientific and Technical Information of China (English)

    尹世昌; 焦振华; 王功国; 汉吉健

    2011-01-01

    Objective:To observe the curative effect of concentrated autogenous bone marrow stem cell transplant combined with traditional Chinese medicine on bone nonunion. Methods.. All 50 patients with bone nonunion were divided into treatment group (A group) which treated by percutaneous autogenous bone marrow stem cell transplant combined with traditional Chinese medicine,and control group (B group) which treated by autogenous bone marrow stem cell transplant only,with 25 cases in each group. The growth of the bony callus and the healing time were observed after treatment. The curative effect was evaluated. Results: All patients in A group with fracture eventually healed, the average healing time was 6.8 months. While,22 patients in B group with fracture eventually healed,the average healing time was 8.4 months. There was statistically significant in fracture healing time between the two groups (P<0.05). Conclusion: Percutaneous autogenous bone marrow stem cell transplant combined with traditional Chinese medicine can improve osteogenesis and promote fracture healing.%目的:观察自体浓缩骨髓移植结合中药骨愈康对骨不连治疗的效果.方法:浓缩自体骨髓移植阳中药组(A组)采用局部经皮自体骨髓移植结合中药内服治疗骨不连患者25例,另设浓缩自体骨髓移植组(B组)采用单纯自体骨髓移植治疗骨不连患者25例,观察X线所示骨痂形成情况和临床体征,评价2组在治疗前后的骨折愈合情况.结果:A组25例患者骨折最终愈合,平均愈合时间6.8个月.B组22例患者骨折最终愈合,平均愈合时间8.4个月.2组骨折愈合时间比较差异有统计学意义(P<0.05).结论:自体骨髓移植结合中药骨愈康可以改善成骨能力,促进骨折愈合.

  9. "Plug" ósseo autógeno para orifícios de trepanação: nota técnica Autogenic bone plug to seal burr holes: technical note

    Directory of Open Access Journals (Sweden)

    JOSUÉ GUIMARÃES GRANHA VIALOGO

    1999-12-01

    Full Text Available Vários materiais são utilizados para ocluir os orifícios de trepanação em neurocirurgia, por motivos variados: para evitar fístula liquórica após trepanações, para auxiliar a fixação do "flap" ósseo e por motivos estéticos, na região frontal. Dentre estes materiais citamos os heterólogos (botões de silicone, miniplacas de metal, cera de osso, metilmetacrilato, gelfoam, cimento de polímero vegetal, cerâmica de hidroxiapatita, e os autólogos (pó de osso originado da trepanação, gordura, músculo, aponeurose. Os materiais heterólogos ou sintéticos podem provocar reação de corpo estranho com erosão da pele e exposição do material, tornando necessária sua retirada, em tempo variável no pós-operatório. Há cerca de três anos, o autor vem utilizando um botão ou "plug" ósseo autólogo, feito com surgicel e o pó de osso proveniente da trepanação, com bom resultado estético eliminando as desconfortáveis depressões cranianas pós-trepanação. Apresentamos a técnica de confecção deste prático `plug ósseo autólogo'. Nas neuroendoscopias, praticamente sanou-se o problema da fístula liquórica e reação de corpo estranho. Encorajamos a utilização deste botão ósseo autólogo em nosso meio, como método eficiente, econômico e biologicamente aceitável para ocluir orifícios cranianos de trepanação.Many neurosurgical procedures can be performed by a single burr hole: neuroendoscopy, microvascular decompression, stereotactic procedures, chronic subdural haematomas. It is technically difficult to suture and close the dura, located at the bottom of such holes, which can lately lead to CSF leakage. On the other hand, the surgical material used to seal the burr holes can be divided in heterogenic (metal screws, silicon plugs, gelfoam, bone wax, metilmetacrilate, hidroxiapatite, and autogenic (fat, aponeurosis, muscle, and bone dust from trephination. The heterogenic group always brings the possibility of

  10. Computed tomography evaluation of autogenous graft in sinus lift surgery

    International Nuclear Information System (INIS)

    The objective was to quantify bone formation within autogenous bone grafts and autogenous bone grafts in combination with platelet-rich plasma obtained either from apheresis or centrifugation using computed tomography. This prospective, double-blind study was conducted in 34 male and female adult patients (mean age of 28 years and 8 months), with either unilateral or bilateral pneumatization of the maxillary sinuses, requiring bone graft for dental implant. All patients were submitted to computed tomography examinations prior and six months after sinus lift surgery. Fifty-three maxillary sinuses were operated and divided into three distinct groups: autogenous bone graft, autogenous bone graft in combination with platelet-rich plasma obtained by centrifugation, and autogenous bone graft in combination with platelet-rich plasma obtained by apheresis. The results showed that computed tomography demonstrated bone growth in height and width between the initial and the follow-up computed tomography scans in all three groups. However, no statistical difference was found either for bone height or width. It was concluded that clinical evidence demonstrates the effectiveness of autogenous bone grafts, particularly when used in combination with bone growth factors such as platelet-rich plasma, which allow prosthetic and functional restoration of maxillofacial structures through fixation of dental implants. (author)

  11. Space maintenance in autogenous fresh demineralized tooth blocks with platelet-rich plasma for maxillary sinus bone formation: a prospective study.

    Science.gov (United States)

    Kim, Eun-Suk; Kang, Ji-Yeon; Kim, Jae-Jin; Kim, Kyoung-Won; Lee, Eun-Young

    2016-01-01

    This prospective study evaluated the effectiveness of autogenous fresh demineralized tooth block (Auto-FDT block) with platelet-rich plasma (PRP) for maxillary sinus augmentation with simultaneous implant installation. Auto-FDT block with PRP was used in Group 1 (n = 15) and combined graft (allograft and xenograft) powder with PRP was used in Group 2 (n = 15). For up to 2 years after the final prosthesis was installed, clinical and radiographic examinations were performed to evaluate the amount of graft materials, residual alveolar height (RAH), sinus height (SH) after grafting, augmented graft height (AGH) and resorption height (RH). In ten cases, biopsies were harvested for histological and histomorphometric analyses. A total of 59 implants were placed in a severe atrophic posterior maxilla with less than 5 mm of RAH and sinus augmentation. None of the patients developed sinusitis or other complications, such as implant loss. The graft material extracted included one molar (or 2 premolars) in Group 1 and 1.8 cc in Group 2. The radiologic examination revealed the following average between-group difference SH (Group 1, 14.12 ± 1.63 mm vs Group 2, 16.51 ± 1.29 mm) and AGH (Group 1, 11.62 ± 2.22 mm vs Group 2, 13.65 ± 1.35 mm). However, sufficient SH and AGH were observed for the implants in the Auto-FDT block group. Two years after final prosthesis was installed, no between-group difference in the RH was observed (Group 1, 1.23 ± 0.73 mm vs Group 2, 1.77 ± 0.54 mm, P = 0.021). The histomorphometric analysis revealed no between-group difference in the new bone volume (Group 1, 23.13 ± 1.42 % vs Group 2, 24.18 ± 2.19 %, P = 0.548). The results showed that Auto-FDT block with PRP can be used in grafted sinuses for implants with only one extracted molar (or two premolars). Auto-FDT block with PRP promotes new bone formation that is comparable with combined grafts. Auto-FDT block with PRP is as an alternative to bone grafting

  12. No advantage to rhBMP-2 in addition to autogenous graft for fracture nonunion.

    Science.gov (United States)

    Takemoto, Richelle; Forman, Jordanna; Taormina, David P; Egol, Kenneth A

    2014-06-01

    Bone morphogenetic proteins are a necessary component of the fracture healing cascade. Few studies have delineated the efficacy of iliac crest bone graft and recombinant human bone morphogenetic protein 2 (rhBMP-2), especially, in comparison with the gold standard treatment of nonunion, which is autogenous bone graft alone. This study compared the outcome of patients with fracture nonunion treated with autogenous bone graft plus rhBMP-2 adjuvant vs patients treated with autogenous bone graft alone. A total of 118 consecutive patients who were to undergo long bone nonunion surgery with autogenous bone graft (50) or autogenous bone graft plus rhBMP-2 (68) were identified. Surgical intervention included either harvested iliac autogenous bone graft or autogenous bone graft plus 1.5 mg/mL of rhBMP-2 placed in and around the site of nonunion. No differences were found in the distribution of nonunion sites included within each group. Twelve-month follow-up was obtained on 100 of 118 patients (84.7%). Analyses of demographic characteristics (including tobacco), medical comorbidities, previous surgeries, and nonunion type (atrophic vs hypertrophic) did not differ. Postoperative complication rates did not differ. The percentage of patients who progressed to union did not differ. Mean time to union in the autogenous bone graft plus rhBMP-2 group was 6.6 months (±3.9) vs 5.4 (±2.7) months in the autogenous bone graft-only group (P=.06). Rates of revision (16.2% for rhBMP-2 plus autogenous bone graft vs 8% for autogenous bone graft) did not differ statistically (P=.19), nor did 12-month scores of pain and functional assessment. Although rhBMP-2 is a safe adjuvant, there was no benefit seen when rhBMP-2 was added to autogenous bone graft in the treatment of long bone nonunion. Given its high cost, rhBMP-2 should be reconsidered as an aid to autogenous bone graft in the treatment of nonunion. PMID:24972432

  13. Healing of Large Segmental Bone Defect after Implantation of Autogenous Cancellous Bone Graft in Comparison to Hydroxyapatite and 0.5% Collagen Scaffold Combined with Mesenchymal Stem Cells

    Czech Academy of Sciences Publication Activity Database

    Nečas, A.; Proks, P.; Urbanová, L.; Srnec, R.; Stehlík, L.; Crha, M.; Raušer, P.; Plánka, L.; Janovec, J.; Dvořák, M.; Amler, Evžen; Vojtová, L.; Jančář, J.

    2010-01-01

    Roč. 79, č. 4 (2010), s. 607-612. ISSN 0001-7213 R&D Projects: GA MŠk 2B06130 Institutional support: RVO:68378041 Keywords : fracture fixation * bone healing * comminuted fracture Subject RIV: FI - Traumatology, Orthopedics Impact factor: 0.534, year: 2010

  14. Method for determination of size and the anatomic shape of autogenic bone transplant according to 3D computer images of the cranium

    International Nuclear Information System (INIS)

    The repair of great mandibular defects is still a real problem in the maxillo-facial surgery. During the treatment planning we use very often only two-dimensional radiographic images and cefalometric analysis. Their possibility to measure three-dimensionally is limited. On the base of 3D-images, created by computer-tomographical SSD - technique, we present a new method to justify the size and anatomical form of the autogenous transplants during mandibular reconstruction

  15. Autogenous Deformation of Concrete

    DEFF Research Database (Denmark)

    Autogenous deformation of concrete can be defined as the free deformation of sealed concrete at a constant temperature. A number of observed problems with early age cracking of high-performance concretes can be attributed to this phenomenon. During the last 10 years , this has led to an increased...... focus on autogenous deformation both within concrete practice and concrete research. Since 1996 the interest has been significant enough to hold international, yearly conferences entirely devoted to this subject. The papers in this publication were presented at two consecutive half-day sessions at the...... American Concrete Institute’s Fall Convention in Phoenix, Arizona, October 29, 2002. All papers have been reviewed according to ACI rules. This publication, as well as the sessions, was sponsored by ACI committee 236, Material Science of Concrete. The 12 presentations from 8 different countries indicate...

  16. Toll-Like Receptor 4 Signaling Pathway Mediates Inhalant Organic Dust-Induced Bone Loss.

    Science.gov (United States)

    Staab, Elizabeth; Thiele, Geoffrey M; Clarey, Dillon; Wyatt, Todd A; Romberger, Debra J; Wells, Adam D; Dusad, Anand; Wang, Dong; Klassen, Lynell W; Mikuls, Ted R; Duryee, Michael J; Poole, Jill A

    2016-01-01

    Agriculture workers have increased rates of airway and skeletal disease. Inhalant exposure to agricultural organic dust extract (ODE) induces bone deterioration in mice; yet, mechanisms underlying lung-bone crosstalk remain unclear. Because Toll-like receptor 2 (TLR2) and TLR4 are important in mediating the airway consequences of ODE, this study investigated their role in regulating bone responses. First, swine facility ODE stimulated wild-type (WT) bone marrow macrophages to form osteoclasts, and this finding was inhibited in TLR4 knock-out (KO), but not TLR2 KO cells. Next, using an established intranasal inhalation exposure model, WT, TLR2 KO and TLR4 KO mice were treated daily with ODE or saline for 3 weeks. ODE-induced airway neutrophil influx and cytokine/chemokine release were similarly reduced in TLR2 and TLR4 KO animals as compared to WT mice. Utilizing micro-computed tomography (CT), analysis of tibia showed loss of bone mineral density, volume and deterioration of bone micro-architecture and mechanical strength induced by ODE in WT mice were significantly reduced in TLR4 but not TLR2 KO animals. Bone marrow osteoclast precursor cell populations were analyzed by flow cytometry from exposed animals. In WT animals, exposure to inhalant ODE increased osteoclast precursor cell populations as compared to saline, an effect that was reduced in TLR4 but not TLR2 KO mice. These results show that TLR2 and TLR4 pathways mediate ODE-induced airway inflammation, but bone deterioration consequences following inhalant ODE treatment is strongly dependent upon TLR4. Thus, the TLR4 signaling pathway appears critical in regulating the lung-bone inflammatory axis to microbial component-enriched organic dust exposures. PMID:27479208

  17. Clinical Usefulness of Mandibular Reconstruction Using Custom-Made Titanium Mesh Tray and Autogenous Particulate Cancellous Bone and Marrow Harvested From Tibia and/or Ilia.

    Science.gov (United States)

    Yamada, Hiroyuki; Nakaoka, Kazutoshi; Sonoyama, Tomoo; Kumagai, Kenichi; Ikawa, Tomoko; Shigeta, Yuko; Harada, Naohiko; Kawamura, Noboru; Ogawa, Takumi; Hamada, Yoshiki

    2016-05-01

    The objective of this study was to evaluate usefulness of mandibular reconstructions using custom-made titanium mesh (Ti-mesh) tray and particulate cancellous bone and marrow (PCBM). Consecutive 21 patients who underwent mandibular reconstruction were enrolled in this study. They were 13 men and 8 women (mean age, 52.0 years). Virtual reality simulation was performed using computer software based on the preoperative computed tomography data. A 3-dimensional skull model was constructed using 3-dimensional printer. A tray was custom-made from Ti-mesh sheet bent to adapt to the model. After PCBM harvesting from posterior ilia and/or proximal tibia, the tray was fixed to the host bone. New bone formation and configuration of the reconstructed mandible were assessed radiologically. Complications were recorded in each patient during the follow-up period. Patients' satisfaction with postoperative facial contour was evaluated using visual analog scale (VAS score, range, 0-100). In 16 of 21 patients, excellent new bone formation was recognized and expected results were radiologically achieved. In 5 patients, new bone formation was insufficient. Causes of insufficient bone formation included postoperative infection in 2 patients, Ti-mesh tray fracture in 2 patients, and local recurrence of lower gingival cancer in 1 patient. To prevent a tray fracture, a double-layered Ti-mesh tray was useful. Mean VAS score on patients' satisfaction was 77.1. Our results comprehensively suggest that mandibular reconstruction using custom-made Ti-mesh tray and PCBM is clinically useful. PMID:27092909

  18. Bone Graft Alternatives

    Science.gov (United States)

    ... cadavers. The types of allograft bone used for spine surgery include fresh frozen and lyophilized (freeze dried). The ... the most common uses of bone grafts in spine surgery is during spinal fusion. The use of autogenous ...

  19. Mechanical properties of radial bone defects treated with autogenous graft covered with hydroxyapatite in rabbit Propriedades mecânicas de defeito de osso radial tratado com enxerto autógeno coberto com nano-hydroxyapatite em coelho

    Directory of Open Access Journals (Sweden)

    Davood Sharifi

    2012-03-01

    Full Text Available PURPOSE: To determine biomechanical property of autogenous bone graft covered with hydroxyapatite in the defect of radial bone in rabbit. METHODS: Eighteen adult male New Zealand white rabbits were used which were divided into three groups (I, II, III of six rabbits each. A segmental bone defect of 10 mm in length was created in the middle of the right radial shaft under general effective anesthesia in all rabbits and were stabilized using mini-plate with four screws. The defects In group I were left as such without filler, whereas in group II the defect were filled up with harvested 10 mm rib bone and in group III the defect were packed with rib bone covered with nano-hydroxyapatite. All rabbits in three groups were divided into two subgroups (one month and three months duration with three rabbits in each one. RESULTS: The mechanical property and the mean load for fracturing normal radial bone was recorded 388.2±6 N whereas it was 72.4±12.8 N for group I in 1 month duration which was recorded 182.4±14.2 N for group II and 211.6±10.4 N for group III at the end of 1 month. These values were 97.6±10.2 N for group I and 324.6±8.2 N for group II and 372.6±17.4 N for group III at the end of three months after implantation. CONCLUSION: Implantation of autologous graft covered with hydroxyapatite indicated to have positive effect in integral formation of qualitative callus at the site of fracture and early re-organization of callus to regain mechanical strength too.OBJETIVO: Determinar as propriedades biomecânicas de enxerto ósseo autógeno coberto com hidroxiapatita em defeito do osso radial em coelhos. MÉTODOS: Foram utilizados 18 coelhos adultos, machos, brancos, Nova Zelândia, distribuídos em três grupos (I, II, III de seis coelhos cada. Um defeito segmentar de 10 mm de comprimento foi criado no meio do eixo radial direito sob anestesia geral efetiva em todos os coelhos e foram fixados usando mini-placa com quatro parafusos. Os

  20. Transplantation of deproteined bovine cancellous bone combined with autogenous red marrow for repairing bony cavity defect due to benign bone tumor: Compared with autologous bone graft%脱蛋白牛松质骨结合自体红骨髓移植修复骨肿瘤性骨缺损:与自体骨移植材料为对照标准的效果比较

    Institute of Scientific and Technical Information of China (English)

    丁真奇; 周亮; 练克俭; 康两奇; 郭延杰; 翟文亮; 郭林新

    2006-01-01

    BACKGROUND: Autologous bone graft was always applied to repair bony cavity defect produced by benign bone tumor.OBJECTIVE: Taking autogenous bone graft for repairing bony cavity defect caused by bone tumor or tumor-like pathological change as control standard, to observe transplantation of deproteined bovine cancellous bone combined with autogenous red marrow in occluding the residual cavity and the density of newly formed bone.DESIGN: A randomized grouping design, controlled observation SETTING: Department of Orthopaedics, the 175 Hospital of Chinese PLA PARTICIPANTS:We recruited 175 cases of bony cavity defect who received treatment in the Department of Orthopaedics, the 175 Hospital of Chinese PLA from July 1993 to July 1998. They were randomly assigned into two groups: experimental group and control group. There were 63 cases treated in the experimental group. The average disease-suffering time was (6.2±2.1) months and bone defect was (136±30) mm3. There were 62 cases treated in the control group. The average disease-suffering time was (6.1±2.3)months, and bone defect was (133±37) mm3.METHODS: Deproteined bovine cancellous bone combined with autogenous red marrow was transplanted in the experimental group and autologous bone graft was applied in the control group. We curetted tumor completely, cauterized the wound with alcohol of 0.95 volume fraction, then curetted the area of cauterization to make it bled. Bone graft was applied.The quantity of implanted bone should be abundant, and disposed compactly. The X-ray films of the first week after operation were used as a standard for density of new bone growth. X-ray films were taken at the 3rd,6th and 8th months postoperatively, and the X-ray films of the eighth months after operation were used as a standard.MAIN OUTCOME MEASURES: To compare the bone union in two groups with a standard of residual cavity occluding and density of bone growth.RESULTS: All patients were followed up for an average of 20 months

  1. Proteínas morfogenéticas ósseas associadas a osso esponjoso autógeno na reparação de falhas experimentais na calota craniana de coelhos (Oryctolagus cuniculus Bone morphogenetic proteins associated with autogenous bone graft in the reparation of calvarial experimental defects of rabbits (Oryctolagus cuniculus

    Directory of Open Access Journals (Sweden)

    B.S. Monteiro

    2007-12-01

    ão determinou maior preenchimento ósseo.Aspects of bone repair were evaluated after implantation of bone morphogenetic proteins (BMP in different concentrations. They were carried by autogenous bone graft in defects created on skulls of 20 adult, young female rabbits, randomizedly divided into five experimental groups and were observed at five times. After exposure of skull bones, six bone defects on the fronto-parietal region of each animal were performed. The defect I was not filled, the II was completed filled with 3mg of autogenous bone graft and the defects III, IV, V, and VI were filled with autogenous bone graft associated with 0.5; 1; 2 and 5mg of BMP, respectively. In the post-mortem mesoscopic evaluations, it was observed that, independently of the treatment period of the defects, the bony filling began from the borders to the center, and from the botton to the surface of the lessions. The bony filling of the defect I was the smallest when compared with the others defects, in all the observation moments. It was also verified that until 2mg the higher the concentration of BMP used, better was the bone cover. Microscopically, it was verified in the first evaluations, on the seventh day, that the bony growth started from the borders and from the bottom of the lesion, with mobilization and differentiation of cells deriving from the periosteum and the meninges, respectively. In the subsequent evaluations, the osteoblastic activity also derived from "ossification islands" to ossification centers, located in the center of the flaw. The trabecular formation increased proportionally with the concentration of BMP used, and the apposition and bony organization increased proportionally with the time of observation. The presence of cartilaginous tissue was verified in all the flaws. In conclusion, the use the higher concentration of BMP did not determinate the better new bone formation. The association of BMP with autogenous bone graft contributed to the formation of new bony

  2. Computed tomography evaluation of autogenous graft in sinus lift surgery; Analise por tomografia computadorizada do enxerto autogeno na cirurgia de 'sinus lift'

    Energy Technology Data Exchange (ETDEWEB)

    Ajzen, Sergio Aron; Moscatiello, Rafael Andrade; Lima, Aida Maria Custodio de; Moscatiello, Vitoria Aparecida Muglia; Helio Kiitiro Yamashita [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Dept. de Diagnostico por Imagem; Mosacatiello, Rafael Muglia; Nishiguchi, Celso Itiro [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Disciplina de Tecnica Operatoria e Cirurgia Experimental; Alves, Maria Teresa de Seixas [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Disciplina de Anatomia Patologica

    2001-02-01

    The objective was to quantify bone formation within autogenous bone grafts and autogenous bone grafts in combination with platelet-rich plasma obtained either from apheresis or centrifugation using computed tomography. This prospective, double-blind study was conducted in 34 male and female adult patients (mean age of 28 years and 8 months), with either unilateral or bilateral pneumatization of the maxillary sinuses, requiring bone graft for dental implant. All patients were submitted to computed tomography examinations prior and six months after sinus lift surgery. Fifty-three maxillary sinuses were operated and divided into three distinct groups: autogenous bone graft, autogenous bone graft in combination with platelet-rich plasma obtained by centrifugation, and autogenous bone graft in combination with platelet-rich plasma obtained by apheresis. The results showed that computed tomography demonstrated bone growth in height and width between the initial and the follow-up computed tomography scans in all three groups. However, no statistical difference was found either for bone height or width. It was concluded that clinical evidence demonstrates the effectiveness of autogenous bone grafts, particularly when used in combination with bone growth factors such as platelet-rich plasma, which allow prosthetic and functional restoration of maxillofacial structures through fixation of dental implants. (author)

  3. Mitigation strategies for autogenous shrinkage cracking

    DEFF Research Database (Denmark)

    Bentz, Dale P.; Jensen, Ole Mejlhede

    2004-01-01

    , the fundamental parameters contributing to the autogenous shrinkage and resultant early-age cracking of concrete are presented. Basic characteristics of the cement paste that contribute to or control the autogenous shrinkage response include the surface tension of the pore solution, the geometry of...... problem of early-age cracking due to autogenous shrinkage. Mitigation strategies discussed in this paper include: the addition of shrinkage-reducing admixtures more commonly used to control drying shrinkage, control of the cement particle size distribution, modification of the mineralogical composition of...... the field, it should be possible to minimize cracking due to autogenous shrinkage via some combination of the presented approaches....

  4. Multipass autogenous electron beam welding

    International Nuclear Information System (INIS)

    A multipass, autogenous welding procedure was developed for 7.6 mm (0.3 in.) wall thickness Type 304L stainless steel cylinders. The joint geometry has a 1.5 mm (0.06 in.) root-face width and a rectangular stepped groove that is 0.762 mm (0.03 in.) wide at the top of the root face and extends 1.5 mm in height, terminating into a groove width of 1.27 mm which extends to the outside of the 1.27 mm high weld-boss. One weld pass is made on the root, three passes on the 0.762 mm wide groove and three passes to complete the weld. Multipass, autogenous, electron beam welds maintain the characteristic high depth-to-width ratios and low heat input of single-pass, electron beam welds. The increased part distortion (which is still much less than from arc processes) in multipass weldments is corrected by a preweld machined compensation. Mechanical properties of multipass welds compare well with single-pass welds. The yield strength of welds in aluminum alloy 5083 is approximately the same for single-pass or multipass electron beam and gas, metal-arc welds. The incidence and size of porosity is less in multipass electron beam welding of aluminum as compared to gas, metal-arc welds. The multipass, autogenous, electron beam welding method has proven to be a reliable way to make some difficult welds in multilayer parts or in an instance where inside part temperature or weld underbead must be controlled and weld discontinuities must be minimized

  5. Anterior Lumbar Intervertebrai Fusion with Artificial Bone in Place of Autologous Bone

    Institute of Scientific and Technical Information of China (English)

    徐卫国; 陈安民; 冯旭; 印卫锋

    2003-01-01

    The feasibility of anterior lumbar intervertebral fusion with artificial bone in place of au-togenous bone was investigated. Porous hydroxyapatite(HA)/ZrO2 ceramics loading bone morpho-genetic protein (BMP) were implanted after removal of lumbar vertebral disc in rabbits. The adja-cent intervertebral discs were also removed by the same way and autogenous illic bone was implan-ted. SEM observation and biomechanical test were carried out. Compound bone had a bit lower os-teoinductive activity than autogenous bone by SEM(Osteoindutive activity of artificial bone in 12weeks was the same as that of autogenous bone in 9 weeks). Biomechanical test revealed that com-pound bone had lower anti-pull strength than autogenous bone (P<0. 001), but there was no sig-nificant difference in anti-pull strength between compound bone at 12th week and autogenous boneat 9th week (P>0.05). It was concluded that compound bone could be applied for anterior spinalfusion, especially for those patients who can't use autogenous bone.

  6. Plasma rico em plaquetas associado ou não ao osso esponjoso autógeno no reparo de falhas ósseas experimentais Platelet rich plasma associated or not to autogenous bone graft on the reparation of experimental bone defects in the rabbits cranium

    Directory of Open Access Journals (Sweden)

    Paloma Sayegh Arreguy Silva

    2009-02-01

    do tipo corpo estranho, que atuou negativamente na fase inicial de reparação.The present study evaluated autogenous platelet rich plasma's (PRP influence on the reparation process of four bone defects made on rabbit's skull, associated or not to autogenous bone graft (EOE. Defect I received PRP only; defect II received 3mg of EOE only; defect III received EOE associated to PRP; defect IV was left to heal naturally, serving as control. After each surgery the animals were randomly divided into three groups that were euthanized at 30, 60 and 90 days. In the mesoscopic evaluation bone ingrowth started from the defect's borders to the center and from the bottom to the surface for all observation times on the control (VI and PRP only (I groups. In the groups treated with EOE only (II and EOE associated to PRP (III new bone was observed in the center of the defects. Radiographic analysis showed greater central radiopacity for groups treated with EOE only (II and EOE associated to PRP (III at all observation times. Microscopically in the group treated with EOE associated to PRP (III at 30 days the graft was indistinguishable from new bone present on the border of the defect, associated to a moderate quantity of a very vascularized and cellular fibrous connective tissue. This tissue showed an extracelular eosinophilic amorphous foamy material, associated to an inflammatory process constituted by lymphocytes and in less number by macrophages and multinucleated giant cells that may have negatively influenced early bone formation. At 60 and 90 days occasional spots of lymphocytic inflammation were observed. Both treatments, PRP associated or not to EOE, were similar for the bone ingrowth at the final time of observation; the graft used alone determined early bone reparation and thromboplastine used for the platelet gel formation incited a foreign body-like reaction that acted negatively on the initial reparation.

  7. Effect of fly ash on autogenous shrinkage

    Energy Technology Data Exchange (ETDEWEB)

    Pipat Termkhajornkit; Toyoharu Nawa; Masashi Nakai; Toshiki Saito [Hokkaido University, Hokkaido (Japan). Division of Structural and Geotechnical Engineering, Graduate School of Engineering

    2005-03-01

    The correlation between autogenous shrinkage and degree of hydration of fly ash was determined with the selective dissolution method. Then, the relationship between the degree of hydration of fly ash and autogenous shrinkage was examined. The results showed that the degree of hydration of fly ash increased as its Blaine surface area increased. The degree of hydration of fly ash increased with time, and autogenous shrinkage increased corresponding to the increase in the degree of hydration of fly ash. Moreover, it was found that the total quantity of Al{sub 2}O{sub 3} in cement-fly ash samples affected autogenous shrinkage at early ages, but the long-term influence was very small.

  8. Autogenous shrinkage, speciality of high performance concretes

    OpenAIRE

    Vogrič, Nina

    2014-01-01

    Autogenous shrinkage is a consequence of self dessication in pores of hardened cement paste and is, at high performance concrete significantly greater than that of the ordinary concretes, mainly due to low water to cement ratio. In the graduation thesis we examined the main mechanisms that cause autogenous shrinkage. It can be reduced by internal curinginternal water reservoirs. As internal water reservoirs we used pre-soaked expanded clay Liapor. On specimens, in which we replaced 12 % of ag...

  9. 镜下髓芯减压BAM骨诱导人工骨治疗股骨头坏死的临床研究%Treatment with BAM artificial bone and autogenous marrow cells implantation after arthroscopic core decompression for ischemic necrosis of femoral head

    Institute of Scientific and Technical Information of China (English)

    李康养; 黄永翔; 李艳玲; 马楚平; 易伟宏; 欧迪军

    2012-01-01

    Objective: To evaluate the feasibility and clinical effects of treatment with BAM artificial bone and autogenous marrow cells implantation after arthroscopic core decompression for ischemic necrosis of femoral head. MethodS:From 2009 to 2011, 25 cases (30 hips) at Ficat stage II and 5 cases (6 hips) at Ficat stage III were selected, and had arthroscopic core decompression with the assistance of ar-throscopy and the localization of C-shaped fluoroscopic machine. Lesion tissues were cleared completely, internal and external environment of femoral head was improved and transplantation of the BAM induced artificial bone and autogenous marrow cells was performed. Follow up were conducted for 3,12 and 24 months after the operation. Harris hip score,X-ray and MRI were performed to evaluate the stability of staging and clinical effect. Results: All patients were followed up for 12 to 24 months. According to Harris hip score, total excellent and good rate was 86. 11%. X-ray showed good bone repairment, and MRI showed no significant decrease in sign of focal zone. Conclusions:Minimally invasive grafting BAM artificial bone and autogenous marrow cells by core decompression under arthroscopy shows advantage of exact diagnosis and localization, as well as minimally invasion. It is effective in the treatment of ischemic necro-sis of the femoral head at stage II and stage HI A .%目的:评估关节镜辅助下髓芯减压植入BAM骨诱导人工骨与自体骨髓细胞治疗早期股骨头坏死可行性和临床疗效..方法:将2009~2011年确诊的股骨头坏死按Ficat分期Ⅱ期25例30髋,Ⅲ期5例6髋;在C型臂透视定位及关节镜辅助下,有效准确地进行髓芯减压,对股骨头内病变组织清除彻底,改善股骨头内外环境,植入BAM骨诱导人工骨与自体骨髓细胞.术后3、12、24个月进行随诊,以Harris髋关节评分、X线片及MRI观察病变分期稳定性及临床疗效为评价指标.结果:全部病例随访12~24个月,按

  10. Extraskeletal and intraskeletal new bone formation induced by demineralized bone matrix combined with bone marrow cells

    International Nuclear Information System (INIS)

    Dilutions of fresh autogenous bone marrow cells in combination with allogeneic demineralized cortical bone matrix were tested extraskeletally in rats using roentgenographic, histologic, and 45Ca techniques. Suspensions of bone marrow cells (especially diluted 1:2 with culture media) combined with demineralized cortical bone seemed to induce significantly more new bone than did demineralized bone, bone marrow, or composite grafts with whole bone marrow, respectively. In a short-term spinal fusion experiment, demineralized cortical bone combined with fresh bone marrow produced new bone and bridged the interspace between the spinous processes faster than other transplantation procedures. The induction of undifferentiated host cells by demineralized bone matrix is further complemented by addition of autogenous, especially slightly diluted, bone marrow cells

  11. Mitigation strategies for autogenous shrinkage cracking

    DEFF Research Database (Denmark)

    Bentz, Dale P.; Jensen, Ole Mejlhede

    2004-01-01

    , the fundamental parameters contributing to the autogenous shrinkage and resultant early-age cracking of concrete are presented. Basic characteristics of the cement paste that contribute to or control the autogenous shrinkage response include the surface tension of the pore solution, the geometry of......As the use of high-performance concrete has increased, problems with early-age cracking have become prominent. The reduction in water-to-cement ratio, the incorporation of silica fume, and the increase in binder content of high-performance concretes all contribute to this problem. In this paper...... problem of early-age cracking due to autogenous shrinkage. Mitigation strategies discussed in this paper include: the addition of shrinkage-reducing admixtures more commonly used to control drying shrinkage, control of the cement particle size distribution, modification of the mineralogical composition of...

  12. 30 CFR 35.20 - Autogenous-ignition temperature test.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Autogenous-ignition temperature test. 35.20... Autogenous-ignition temperature test. (a) Purpose. The purpose of this test, referred to hereinafter as the ignition-temperature test, is to determine the lowest autogenous-ignition temperature of a hydraulic...

  13. Identification of microcracks caused by autogenous shrinkage

    DEFF Research Database (Denmark)

    Lura, Pietro; Jensen, Ole Mejlhede; Guang, Ye;

    2005-01-01

    Detection and quantification of microcracks caused by restrained autogenous shrinkage in high-performance concrete is difficult. Available techniques either lack the required resolution or may cause further cracks indistinguishable from the original ones. The new technique presented in this paper...... the autogenous shrinkage and cause crack formation during hardening. Subsequently, liquid gallium is intruded into the cracks under pressure. After solidification of the gallium, the crack pattern is frozen and can be analyzed after plane polishing of the samples. The microcracks are identified by...

  14. Autogenous transplantation of mandibular third molar to replace tooth with vertical root fracture

    OpenAIRE

    Asgary, Saeed

    2009-01-01

    Autogenous tooth transplantation (ATT) can be considered when there is a hopeless molar tooth and suitable donor present. This report presents an unconventional case of successful ATT of a third molar replacing the adjacent fractured second molar in a 33 year old woman. This wisdom tooth had completely developed roots. Root-end filling with Calcium Enriched Mixture (CEM) cement was performed in the third molar. The second molar was extracted non-traumatically without any bone removal; the wis...

  15. 9 CFR 113.113 - Autogenous biologics.

    Science.gov (United States)

    2010-01-01

    ... applicable standard requirement potency tests provided in 9 CFR part 113. If the culture of microorganisms... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Autogenous biologics. 113.113 Section... information. (If any of the data are unavailable, the applicant for authorization should indicate that...

  16. Miniplate fixation for the repair of segmental mandibular defects filled with autogenous bone in cats Uso de miniplacas na fixação de mandíbulas de gatos com defeitos segmentares preenchidos com osso autógeno

    Directory of Open Access Journals (Sweden)

    Adelina Maria da Silva

    2011-06-01

    Full Text Available PURPOSE: To evaluate the use of maxillofacial miniplate 1.5 in the repair of segmental mandibular defects filled with autogenous bone in cats. METHODS: Twelve adult cats were divided into two groups. A segmental defect of 4mm was created in one of the hemimandibles and filled with autogenous iliac crest bone graft. The operated hemimandible was fixed with a 1.5mm titanium miniplate. In group 1 (n=6, the defect was performed in the body of the mandible, behind the 1st molar. In group 2 (n=6, the defect was performed between the 4nd premolar and 1st molar, with extraction of the 1st molar. Oral alimentation was reinitiated 24 hours after surgery. Cats were euthanized at 20 weeks postoperative. RESULTS: Incorporation of the graft was suggested by the radiographs taken 20 weeks after surgery. Macroscopic examination confirmed alignment and bone union of operated hemimandibles. Histological examination showed formation of woven bone in rostral and caudal mandible/graft interfaces. The percentage of bone tissue at these areas was measured by the histometry. There was no statistically significant difference between the values of group 1(64.48 ± 4.51 and group 2 (71.69 ± 14.47 (Mann-Whitney's test p= 0.294. CONCLUSION: The use of miniplate 1.5 for the fixation of mandibular defects filled with autogenous bone in cats provided the main goals in the treatment of mandibular fractures: bone union, normal dental occlusion and immediate return to oral alimentation.OBJETIVO: Avaliar o uso de miniplacas na fixação de mandíbulas de gatos com defeitos segmentares preenchidos com osso autógeno. MÉTODOS: Foram utilizados 12 gatos adultos divididos em dois grupos de seis animais cada. Em uma das hemimandíbulas foi criado um defeito segmentar de 4mm, preenchido com enxerto autógeno do osso ilíaco. A hemimandíbula operada foi fixada com uma miniplaca 1.5 de titânio. No grupo 1, o defeito foi realizado caudalmente ao 1º molar e no grupo 2, entre o 4º pr

  17. Comparison of clinical efficacies of single segment transforaminal lumbar interbody fusion with cage versus autogenous morselized bone for degenerative lumbar spinal stenosis: a prospective randomized controlled study%椎间融合器植入与单纯自体颗粒骨植骨治疗退变性腰椎管狭窄症的比较

    Institute of Scientific and Technical Information of China (English)

    刘培盛; 刘小臻; 乔雪静; 都文楠; 罗大伟; 郑修军

    2014-01-01

    Objective To compare the clinical efficacies of single segment transforaminal lumbar interbody fusion (TLIF) with cage versus autogenous morselized bone for degenerative lumbar spinal stenosis.Methods A total of 87 patients undergoing single segment TLIF were randomly divided into 2 groups.A cage was implanted into intervertebral space in group A patients while autogenous morselized bone in group B patients.Operative duration,blood loss,length of stay and cost of hospitalization of two groups were recorded.They were followed up at 1 week,12,24 months post-operation.Oswestry disability index (ODI),visual analogue scale (VAS) fusion rates,intervertebral space and foramen height restoration,lumbar lordosis and postoperative complications were compared between two groups.Results No significant inter-group difference existed in operative duration,blood loss or length of stay.However,the average hospitalization cost in group A were 18% higher than that of group B (P < 0.05).Both groups achieved excellent clinical outcomes within 2 years.ODI,VAS score improvement rates and postoperative complication rates were not statistically different.Lumbar fusion rate was 86.7% in group A versus 85.7% in group B after 2 years.And there was no significant difference (P > 0.05).The heights of intervertebral space and foramen in group A achieved a better recovery than those of group B.Both groups had similar improvements of lumbar lordosis.Conclusion For degenerative lumbar spinal stenosis,usage of interbody cage is more effective in terms of recovery of intervertebral space and foraminal height compared with usage of bone graft.However it brings no better clinical efficacy while the usage of autogenous morselized bone is more cost-effective.Two grafting methods yield similar overall clinical outcomes.%目的 比较单节段经椎间孔腰椎椎间融合术(TLIF)手术中椎间融合器植入或单纯自体颗粒骨植骨两种融合方式治疗退变性腰椎管

  18. 聚甲基丙烯酸甲酯和自体骨加强的椎弓根螺钉技术治疗退变性脊柱侧凸的临床疗效比较%Autogenous bone and polymethylmethacrylate augmentation of screw fixation for degenerative scoliosis

    Institute of Scientific and Technical Information of China (English)

    谢杨; 傅强; 陈自强; 石志才; 朱晓东; 孙晓飞; 李明

    2012-01-01

    Objective To compare the clinical effect of autogenous bone and polymethylmethacrylate (PMMA) augmentation of screw fixation in degenerative scoliosis with osteoporosis. Methods A retrospective analysis was conducted on 31 consecutive patients with degenerative scoliosis combined with osteoporosis who accepted pedicle screw fixation from December 2000 to December 2006. Fourteen of them underwent fixation with pedicle screw by augmentation with PMMA and the other 17 patients with autogenous bone. Peri-operative data were recorded. Preoperative, postoperative and final follow up corrective effects were compared. Results No significant difference was found in clinical data except for administration time of oral pain relief medicines and surgery cost between the two surgical strategies. Cement leakage was observed in 2 patients in PMMA augmentation group, but there was no evidence of nerve damage. Conclusion There is no difference in surgical effect between two surgery strategies on degenerative scoliosis combined with osteoporosis. Less oral pain medicines are taken in the polymethylmethacrylate-augmented pedicle screw fixation and fusion, but with much more cost and danger of cement leakage.%目的 比较应用聚甲基丙烯酸甲酯( PMMA)和自体骨加强的椎弓根螺钉技术治疗合并骨质疏松的退变性脊柱侧凸的临床疗效.方法 回顾性分析2000年12月至2006年12月手术治疗的31例伴骨质疏松的退变性脊柱侧凸患者,其中14例采用PMMA加强钉道,17例采用自体骨加强钉道.记录并发症等围手术期情况,比较手术前后及随访期间侧凸的矫正效果.结果 两种手术除口服止痛药使用时间和手术费用外,其他临床数据差异无统计学意义,PMMA加强组中2例出现骨水泥渗漏,但未出现神经损伤的症状.结论 两种手术对伴骨质疏松的退变性脊柱侧凸的临床疗效无明显差异,PMMA加强的椎弓根螺钉内固定融合术可减少口服止痛药的用量,

  19. Reduction of the early autogenous shrinkage of high strength concrete

    OpenAIRE

    Saje, Drago

    2016-01-01

    he results of a laboratory investigation on the early autogenous shrinkage of high strength concrete, and the possibilities of its reduction, are presented. Such concrete demonstrates signiicant autogenous shrinkage, which should, however, be limited in the early stages of its development in order to prevent the occurrence of cracks and/or drop in the load-carrying capacity of concrete structures.he following possibilities for reducing autogenous shrinkagewere investigated: the use of low-hea...

  20. Reduction of the Early Autogenous Shrinkage of High Strength Concrete

    OpenAIRE

    Drago Saje

    2015-01-01

    The results of a laboratory investigation on the early autogenous shrinkage of high strength concrete, and the possibilities of its reduction, are presented. Such concrete demonstrates significant autogenous shrinkage, which should, however, be limited in the early stages of its development in order to prevent the occurrence of cracks and/or drop in the load-carrying capacity of concrete structures. The following possibilities for reducing autogenous shrinkage were investigated: the use of lo...

  1. Autogenous Deformation and Change of the Relative Humidity in Silica Fume-Modified Cement Paste

    DEFF Research Database (Denmark)

    Jensen, Ole mejlhede; Hansen, Per Freiesleben

    1996-01-01

    Even during sealed curing and at a constant temperature a hardening cement paste will deform and the relative humidity within its pores will lower. This autogenous deformation and autogenous relative humidity change may be so significant that the cement paste cracks if the deformation is restrained....... This article focuses on the influence of silica fume addition on autogenous deformation and autogenous relative humidity change. Continuous measurement of autogenous deformation and autogenous relative humidity change for more than 1 year and 1« years, respectively, was performed. The investigations...... show thatsilica fume addition markedly increases the autogenous shrinkage as well as the autogenous relative humidity change....

  2. Autogenic training as a therapy for adjustment disorder in adolescents

    Directory of Open Access Journals (Sweden)

    Jojić Boris R.

    2005-01-01

    Full Text Available INTRODUCTION Autogenic training is a widespread technique used in psychotherapy. The British school of autogenic training cites a large list of diseases, health states, and life changes, in which autogenic training can be of help. We wanted to explore the application of autogenic training as a therapy for adjustment disorder in adolescents. The sample consisted of a homogeneous group of 31 individuals, with an average age of 17.3±0.2 years, who were diagnosed with adjustment disorder, F 43.2, in accordance with ICD 10 search criteria. OBJECTIVE The aim of our work was to figure out the influence of autogenic training on adjustment disorder, through biophysical and biochemical indicators, and to research the efficacy of autogenic training as a therapy for adjustment disorder in adolescents. METHOD We observed adjustment disorder indicators and their changes in three phases, using initial, final, and control values, which we measured immediately before the beginning, immediately after the completion, and six months after the completion, of the practical course in autogenic training. We measured systolic and diastolic arterial blood pressure, brachial pulse rates, cortisol levels in plasma, cholesterol levels in blood, as well as glucose concentrations. During that period, autogenic training was employed as the sole therapy. RESULTS The study confirmed our preliminary assumptions. The measurements we performed showed that arterial blood pressure, pulse rates, cholesterol and cortisol concentrations, after the application of autogenic training among adolescents suffering from adjustment disorder, were lower than the initial values. They remained lower even six months after the completion of the practical course in autogenic training. CONCLUSION We concluded that autogenic training significantly decreases the values of physiological indicators of adjustment disorder, diminishes the effects of stress in an individual, and eases the adaptation of

  3. Modelling autogenous expansion for magnesia concrete in arch dams

    Institute of Scientific and Technical Information of China (English)

    Feng JIN; Guoxin ZHANG; Xiaoqing LUO; Chuhan ZHANG

    2008-01-01

    Magnesia Concrete is a kind of expansive con-crete used in Chinese hydraulic engineering more and more widely. To evaluate the effects of autogenous expan-sion on the stresses of arch dams, a simple model of auto-genous expansion for Magnesia Concrete in dam engineering is presented. This model is based on three assumptions: 1) the total amount of autogenous expan-sion of Magnesia Concrete is related only to the properties of materials and mixing of concrete; 2) the autogenous expansion of Magnesia Concrete is irreversible due to the irreversibility of hydration reaction of Magnesia in the concrete; 3) the autogenous expansion strain rates of Magnesia Concrete bear a relation between temperature and residual Magnesia per unit volume of concrete. The model is verified by some experimental data of autogen-ous expansion of Magnesia Concrete and field-measured data of an arch dam in China. Embedded into finite ele-ment arch dam simulation software, this model is employed to simulate the effects of autogenous expansion of Magnesia Concrete in hydraulic engineering.

  4. Impact of bone graft harvesting techniques on bone formation and graft resorption

    DEFF Research Database (Denmark)

    Saulacic, Nikola; Bosshardt, Dieter D; Jensen, Simon S;

    2015-01-01

    BACKGROUND: Harvesting techniques can affect cellular parameters of autogenous bone grafts in vitro. Whether these differences translate to in vivo bone formation, however, remains unknown. OBJECTIVE: The purpose of this study was to assess the impact of different harvesting techniques on bone fo...

  5. Autogenous Phenomena in Cement-Based Materials

    DEFF Research Database (Denmark)

    Jensen, Ole Mejlhede

    , som styrer deformationsforløbet. I forbindelse med denne afhandling er disse to fænomener blevet studeret gennem flere år. Den gennemgående tilgang har været at variere en lang række systemparametre – bl.a. temperatur, mikrosilicatilsætning, cementtype og vand/cement-forhold – og via en efterfølgende...... meningsfuld, eksperimentel definition af afbinding samt en operationel, teoretisk beskrivelse af sammenhængen mellem autogen deformation og RF-ændring. Specifikt vedrørende den foreslåede løsningsstrategi for autogent svind åbner denne afhandling op for en række nye muligheder. Som et eksempel på dette kan...

  6. Reduction of the Early Autogenous Shrinkage of High Strength Concrete

    Directory of Open Access Journals (Sweden)

    Drago Saje

    2015-01-01

    Full Text Available The results of a laboratory investigation on the early autogenous shrinkage of high strength concrete, and the possibilities of its reduction, are presented. Such concrete demonstrates significant autogenous shrinkage, which should, however, be limited in the early stages of its development in order to prevent the occurrence of cracks and/or drop in the load-carrying capacity of concrete structures. The following possibilities for reducing autogenous shrinkage were investigated: the use of low-heat cement, a shrinkage-reducing admixture, steel fibres, premoistened polypropylene fibres, and presoaked lightweight aggregate. In the case of the use of presoaked natural lightweight aggregate, with a fraction from 2 to 4 mm, the early autogenous shrinkage of one-day-old high strength concrete decreased by about 90%, with no change to the concrete's compressive strength in comparison with that of the reference concrete.

  7. Measuring autogenous strain of concrete with corrugated moulds

    DEFF Research Database (Denmark)

    Tian, Qian; Jensen, Ole Mejlhede

    A reliable technique to quantify autogenous strain is a prerequisite to numerical modeling in stress calculations for high performance concrete. The introducing of a special kind of corrugated tube mould helps to transforming volume strain measurement into liner strain measurement in horizontal...... direction for fluid concrete, which not only realizes the continuous monitoring of the autogenous shrinkage since casting, but also effectively eliminates the disturbance resulting from gravity, temperature variation and mould restraint on measuring results. Based on this measuring technique, this paper...

  8. Bone

    International Nuclear Information System (INIS)

    Bone scanning provides information on the extent of primary bone tumors, on possible metastatic disease, on the presence of osteomyelitis prior to observation of roentgenographic changes so that earlier therapy is possible, on the presence of collagen diseases, on the presence of fractures not disclosed by x-ray films, and on the evaluation of aseptic necrosis. However, the total effect and contribution of bone scanning to the diagnosis, treatment, and ultimate prognosis of pediatric skeletal diseases is, as yet, unknown. (auth)

  9. Biological and physical properties of autogenous vascularized fibular grafts in dogs

    International Nuclear Information System (INIS)

    The biological and biomechanical properties of normal fibulae, fibulae that had had a sham operation, and both vascularized and non-vascularized autogenous grafts were studied in dogs at three months after the operation. The study was designed to quantify and correlate changes in these properties in orthotopic, stably fixed, weight-bearing grafts and to provide a baseline for additional studies of allografts. The grafts were eight centimeters long and internally fixed. The mechanical properties of the grafts were studied by torsional testing. Metabolic turnover of the grafts was evaluated by preoperative labeling of the dogs with 3H-tetracycline for resorption of bone mineral and with 3H-proline for turnover of collagen. Cortical bone area and porosity were measured. Postoperative formation of bone was evaluated by sequential labeling with fluorochrome. The vascularized grafts resembled the fibulae that had had a sham operation and those that had not had an operation with regard to the total number of osteons and the remodeling process, as measured both morphometrically and metabolically. The vascularized grafts were stronger and stiffer than the non-vascularized grafts and were not different from the bones that had had a sham operation. In contrast, the non-vascularized grafts were smaller, weaker, less stiff, and more porotic, had fewer osteons, and demonstrated increased turnover and resorption compared with the vascularized grafts, the bones that had had a sham operation, and the bones that had not been operated on

  10. Effects of a buried magnetic field on cranial bone reconstruction in rats

    Science.gov (United States)

    de ABREU, Maíra Cavallet; PONZONI, Deise; LANGIE, Renan; ARTUZI, Felipe Ernesto; PURICELLI, Edela

    2016-01-01

    ABSTRACT The understanding of bone repair phenomena is a fundamental part of dentistry and maxillofacial surgery. Objective The present study aimed to evaluate the influence of buried magnetic field stimulation on bone repair in rat calvaria after reconstruction with autogenous bone grafts, synthetic powdered hydroxyapatite, or allogeneic cartilage grafts, with or without exposure to magnetic stimulation. Material and Methods Ninety male Wistar rats were divided into 18 groups of five animals each. Critical bone defects were created in the rats’ calvaria and immediately reconstructed with autogenous bone, powdered synthetic hydroxyapatite or allogeneic cartilage. Magnetic implants were also placed in half the animals. Rats were euthanized for analysis at 15, 30, and 60 postoperative days. Histomorphometric analyses of the quantity of bone repair were performed at all times. Results These analyses showed significant group by postoperative time interactions (p=0.008). Among the rats subjected to autogenous bone reconstruction, those exposed to magnetic stimulation had higher bone fill percentages than those without magnetic implants. Results also showed that the quality of bone repair remained higher in the former group as compared to the latter at 60 postoperative days. Conclusions After 60 postoperative days, bone repair was greater in the group treated with autogenous bone grafts and exposed to a magnetic field, and bone repair was most pronounced in animals treated with autogenous bone grafts, followed by those treated with powdered synthetic hydroxyapatite and allogeneic cartilage grafts. PMID:27119765

  11. Estimulação da cicatrização óssea pelo plasma autógeno rico em plaquetas: estudo experimental em coelhos Bone healing stimulation by platelet-rich autogenous plasma: an experimental study in rabbits

    Directory of Open Access Journals (Sweden)

    Elisabete Mitiko Kobaiashi Wilson

    2006-01-01

    Full Text Available O plasma sangüíneo autógeno com alta concentração de plaquetas obtido por centrifugação (plasma rico em plaquetas, ou PRP tem sido utilizado na prática clínica para estimular a cicatrização óssea numa variedade de situações, sob alegação de que ele carrega uma elevada concentração de fatores de crescimento derivados da plaqueta e beta-transformadores, os quais sabidamente estimulam o crescimento e regeneração de diferentes tecidos. No presente estudo, o PRP foi utilizado para reparar uma falha óssea diafisária segmentar de meia espessura e 2 cm de comprimento produzida no radio de coelhos Nova Zelândia. O periósteo foi ressecado na circunferência do local da falha e a cavidade medular foi selada com cera óssea em todos os animais para bloquear a chegada de celular regeneradoras que não fossem do próprio osso, mas dos tecidos vizinhos. Três grupos de 15 animais cada foram planejados, de acordo com o procedimento realizado: 1 falha deixada vazia; 2 falha preenchida com o PRP; e 3 falha preenchida com um material inerte (Gelfoam®. Em cada grupo os animais foram distribuídos em três subgrupos de acordo com o período de observação pós-operatória, de 4, 8 e 12 semanas, respectivamente, depois do qual os animais foram mortos e o radio, ressecado para os estudos histológicos. Radiografias e cintilografias foram obtidas a intervalos de 4 semanas, começando na quarta semana pós-operatória. Cicatrização completa e remodelação foram observadas no grupo 2 já na 8ª semana, enquanto que nos grupos 1 e 3 esse processo era apenas parcial na 12ª. A captação do tecnécio estava aumentada em todos os grupos, assim permanecendo durante todo o período de observação nos grupos 1 e 3, mas diminuindo da 8ª para a 12ª semana no grupo 2, acompanhando o processo de remodelação, com diferenças significantes entre os grupos (pThe autogenous blood plasma with high platelet concentration obtained through centrifugation

  12. Influence of temperature on autogenous deformation and relative humidity change in hardening cement paste

    DEFF Research Database (Denmark)

    Jensen, Ole Mejlhede; Hansen, Per Freiesleben

    1999-01-01

    This paper deals with autogenous deformation and autogenous relative humidity change (RH change) in hardening cement paste. Theoretical considerations and experimental data are presented, which elucidate the influence of temperature on these properties. This is an important subject in the control...... of early age cracking of concrete. It is demonstrated that the traditional maturity concept generally is not applicable to autogenous deformation and autogenous RH change. (C) 1999 Elsevier Science Ltd. All rights reserved....

  13. Treatment of Infected Tibial Nonunion with Bone Defect Using Central Bone Grafting Technique

    OpenAIRE

    Gulan, Gordan; Jotanović, Zdravko; Jurdana, Hari; Šestan, Branko; Rapan, Saša; Rubinić, Dušan; Ravlić-Gulan, Jagoda

    2012-01-01

    Treatment of infected tibial nonunion with bone defect represents a challenge for every orthopaedic surgeon. Various methods of treatment have been described for nonunions with infection, bone loss or both. One of them is the central bone grafting technique, which is a safe and effective treatment for nonunions of the tibia. The technique involves placement of autogenous cancellous bone from the iliac crest on the anterior surface of the interosseous membrane with the aim of creating...

  14. Cracking in cement paste induced by autogenous shrinkage

    DEFF Research Database (Denmark)

    Lura, Pietro; Jensen, Ole Mejlhede; Weiss, Jason

    2009-01-01

    Detection and quantification of microcracks caused by restrained autogenous shrinkage in high-performance concrete is a difficult task. Available techniques either lack the required resolution or may produce additional cracks that are indistinguishable from the original ones. A recently developed...... shrinkage of the paste and may cause crack formation. The crack pattern is identified by impregnation with gallium and analyzed by optical and scanning electron microscopy. In this study, a non-linear numerical analysis of the samples was performed. Autogenous strain, elastic modulus, fracture energy, and...

  15. Autogenous healing properties of cement-based grouts

    International Nuclear Information System (INIS)

    This report presents the results of a study conducted to provide information on the ability of cement-based grouts to self-seal. Autogenous sealing was investigated both on bulk grouts and in thin films of grouts. In both cases, the self-sealing capabilities of the cement-based grouts were investigated with water flowing through the grout. Autogenous sealing was studied through changes in pore structure (decrease in pore radius and volume of pores) and changes in the rate of water flow through the cement-based grouts. (author)

  16. Measuring autogenous strain of concrete with corrugated moulds

    DEFF Research Database (Denmark)

    Tian, Qian; Jensen, Ole Mejlhede

    direction for fluid concrete, which not only realizes the continuous monitoring of the autogenous shrinkage since casting, but also effectively eliminates the disturbance resulting from gravity, temperature variation and mould restraint on measuring results. Based on this measuring technique, this paper......A reliable technique to quantify autogenous strain is a prerequisite to numerical modeling in stress calculations for high performance concrete. The introducing of a special kind of corrugated tube mould helps to transforming volume strain measurement into liner strain measurement in horizontal...

  17. The effect of bone marrow aspirate, bone graft and collagen composites on fixation of bone implants

    DEFF Research Database (Denmark)

    Babiker, Hassan; Ding, Ming; Overgaard, Søren

    2007-01-01

     Introduction: Replacement of extensive local bone loss especially in revision joint arthroplasties is a significant clinical challenge. Autogenous and allogenic cancellous bone grafts have been the gold standard in reconstructive orthopaedic surgery, but it is well known that there is morbidity...... associated with harvesting of autogenous bone graft and limitations in the quantity of bone available. Disadvantages of allograft include the risk of bacterial or viral contamination and non union as well as the potential risk of disease transmission. Alternative options are attractive and continue to be...... sought. Hydroxyapatite and collagen composites have the potential in mimicking and replacing skeletal bones. Aim: This study attempted to determine the effect of hydroxyapatite/collagen composites in the fixation of bone implants. The composites used in this study is produced by Institute of Science and...

  18. Effect of anti-inflammatory agents on the integration of autogenous bone graft and bovine bone devitalized matrix in rats Efeito de antiinflamatórios na integração de enxerto ósseo autógeno e de matriz óssea bovina desvitalizada em ratos

    Directory of Open Access Journals (Sweden)

    Roberto Antoniolli da Silva

    2008-04-01

    Full Text Available PURPOSE: To study the repair of bone defect filled with autograft or bovine bone devitalized matrix in rats under anti-inflammatory action. METHODS: Two hundred and forty Wistar rats were distributed to two groups of 120 animals each. A 2mm-diameter defect was created in the femoral diaphysis. Animals of Group I had the bone defect filled with autograft and those of Group II, with bovine bone devitalized matrix. Animals of each group were redistributed to four subgroups according to the intramuscular administration of anti-inflammatory drug or saline solution: A - diclofenac sodium; B - dexamethasone; C - meloxicam; D - saline solution. Evaluation periods were 7, 14 and 30 days. Histological evaluation consisted of quantifying the inflammatory process, the bone neoformation, the collagen formation and the presence of macrophages. RESULTS: Animals of Group I did not show significant difference considering inflammatory reaction. Significant and progressive increase of bone neoformation was observed in both groups. The animals that received meloxicam and autograft showed less collagen formation at 14 and 30 days. The number of macrophages was higher in Group II than in Group I. The animals treated with dexamethasone and saline solution did not show statistically significant difference. CONCLUSIONS: Diclofenac sodium and meloxicam delayed bone graft repair and dexamethasone did not interfere in it.OBJETIVO: Estudar o reparo do defeito ósseo preenchido com enxerto ósseo autógeno ou matriz óssea bovina desvitalizada sob ação de antiinflamatórios em ratos. MÉTODOS: 240 ratos Wistar, distribuídos em dois grupos de 120 animais. Confeccionou-se defeito de 2 mm de diâmetro na diáfise femoral. Os animais do Grupo I tiveram o defeito ósseo preenchido com enxerto ósseo autógeno e os do Grupo II com matriz óssea bovina desvitalizada. Cada grupo foi redistribuído em quatro subgrupos segundo a administração intramuscular de antiinflamatório ou

  19. Autogenous Metallic Pipe Leak Repair in Potable Water Systems.

    Science.gov (United States)

    Tang, Min; Triantafyllidou, Simoni; Edwards, Marc A

    2015-07-21

    Copper and iron pipes have a remarkable capability for autogenous repair (self-repair) of leaks in potable water systems. Field studies revealed exemplars that metallic pipe leaks caused by nails, rocks, and erosion corrosion autogenously repaired, as confirmed in the laboratory experiments. This work demonstrated that 100% (N = 26) of 150 μm leaks contacting representative bulk potable water in copper pipes sealed autogenously via formation of corrosion precipitates at 20-40 psi, pH 3.0-11.0, and with upward and downward leak orientations. Similar leaks in carbon steel pipes at 20 psi self-repaired at pH 5.5 and 8.5, but two leaks did not self-repair permanently at pH 11.0 suggesting that water chemistry may control the durability of materials that seal the leaks and therefore the permanence of repair. Larger 400 μm holes in copper pipes had much lower (0-33%) success of self-repair at pH 3.0-11.0, whereas all 400 μm holes in carbon steel pipes at 20 psi self-repaired at pH 4.0-11.0. Pressure tests indicated that some of the repairs created at 20-40 psi ambient pressure could withstand more than 100 psi without failure. Autogenous repair has implications for understanding patterns of pipe failures, extending the lifetime of decaying infrastructure, and developing new plumbing materials. PMID:26057741

  20. Thermodynamics of Autogenous Self-healing in Cementitious Materials

    NARCIS (Netherlands)

    Huang, H.

    2014-01-01

    Concrete is a brittle composite cementitious material that easily fractures under tensile loading. Microcracks can appear throughout the concrete prior to application of any load because of temperature-induced strain and autogenous and drying shrinkage. There is no doubt that these cracks provide pr

  1. Análise por tomografia computadorizada do enxerto autógeno na cirurgia de "sinus lift" Computed tomography evaluation of autogenous graft in sinus lift surgery

    Directory of Open Access Journals (Sweden)

    Sérgio Aron Ajzen

    2005-02-01

    Full Text Available OBJETIVO: Quantificar a formação óssea nos enxertos com e sem plasma rico em plaquetas, obtido pelos métodos de centrifugação e aférese, comparando os três tipos de enxertos realizados por meio de análise tomográfica. MATERIAIS E MÉTODOS: Este estudo prospectivo, duplo cego, utilizou uma amostra composta de 34 pacientes adultos, de ambos os sexos, com idade média de 48 anos e 8 meses, portadores de pneumatização unilateral ou bilateral dos seios maxilares, que necessitavam de enxertos ósseos, com a finalidade de melhorar as condições locais para a colocação dos implantes dentários. Todos os pacientes realizaram tomografia computadorizada antes da cirurgia. Foram operados 53 seios maxilares, divididos em três grupos: enxerto de plasma rico em plaquetas obtido pelos métodos de aférese, centrifugação e enxerto apenas de osso autógeno. Após seis meses do procedimento cirúrgico foram realizados novos exames de imagem. RESULTADOS: Pela avaliação tomográfica, houve crescimento em altura e em largura nos três grupos quando foram comparados os momentos inicial e final, entretanto, não houve diferença estatística para a altura e para a largura. CONCLUSÃO: Evidências clínicas demonstram a eficácia dos enxertos autógenos, principalmente os associados a fatores indutores de crescimento ósseo, como o plasma rico em plaquetas, recuperando o arcabouço maxilofacial, necessário para a reconstrução protética e funcional por meio de implantes dentários.OBJECTIVE: To quantify bone formation within autogenous bone grafts and autogenous bone grafts in combination with platelet-rich plasma obtained either from aphaeresis or centrifugation using computed tomography. MATERIALS AND METHODS: This prospective, double-blind study was conducted in 34 male and female adult patients (mean age of 28 years and 8 months, with either unilateral or bilateral pneumatization of the maxillary sinuses, requiring bone graft for dental

  2. Bone Substitutes for Peri-Implant Defects of Postextraction Implants

    OpenAIRE

    Pâmela Letícia Santos; Jéssica Lemos Gulinelli; Cristino da Silva Telles; Walter Betoni Júnior; Roberta Okamoto; Vivian Chiacchio Buchignani; Thallita Pereira Queiroz

    2013-01-01

    Placement of implants in fresh sockets is an alternative to try to reduce physiological resorption of alveolar ridge after tooth extraction. This surgery can be used to preserve the bone architecture and also accelerate the restorative procedure. However, the diastasis observed between bone and implant may influence osseointegration. So, autogenous bone graft and/or biomaterials have been used to fill this gap. Considering the importance of bone repair for treatment with implants placed immed...

  3. Measuring techniques for autogenous strain of cement paste

    DEFF Research Database (Denmark)

    Lura, Pietro; Jensen, Ole Mejlhede

    2006-01-01

    the volumetric method. Water absorption is driven by a lowering of the water activity in the cement paste due to dissolved salts in the pore fluid and to self-desiccation. From the moment of casting, significant water uptake was registered in all experiments. This water uptake influenced the......Volumetric measurement of autogenous strain is frequently performed by placing the fresh cement paste in a rubber membrane submerged in water. The volume change of the cement paste is measured by the amount of water displaced by the submerged sample. Volumetric and linear measurements of autogenous...... strain should in principle give identical results. However, the measuring results from the volumetric method are typically 3-5 times higher than the results from the linear technique. In this paper, water uptake from the buoyancy bath through the rubber membrane is identified as the principal artefact of...

  4. Measuring techniques for autogenous strain of cement paste

    DEFF Research Database (Denmark)

    Lura, Pietro; Jensen, Ole Mejlhede

    2007-01-01

    the volumetric method. Water absorption is driven by a lowering of the water activity in the cement paste due to dissolved salts in the pore fluid and to self-desiccation. From the moment of casting, significant water uptake was registered in all experiments. This water uptake influenced the......Volumetric measurement of autogenous strain is frequently performed by placing the fresh cement paste in a rubber membrane submerged in water. The volume change of the cement paste is measured by the amount of water displaced by the submerged sample. Volumetric and linear measurements of autogenous...... strain should in principle give identical results. However, the measuring results from the volumetric method are typically 3-5 times higher than the results from the linear technique. In this paper, water uptake from the buoyancy bath through the rubber membrane is identified as the principal artefact of...

  5. Reducing the morbidity involved in harvesting autogenous rib cartilage.

    Science.gov (United States)

    Siegert, Ralf; Magritz, Ralph

    2009-08-01

    Although the use of autogenous cartilage is the gold standard in auricular reconstruction, its main disadvantage is the morbidity due to harvesting the cartilage. This includes postoperative pain, visible scar, and possibly asymmetry and reduced stability of the thorax. To reduce all of these drawbacks, we describe some modifications that reduce pain to a low tolerable level, hide the scar invisibly in the submammary fold in females, and induce regeneration as well reestablish stability of the rib defect. PMID:19809948

  6. Thermodynamics of Autogenous Self-healing in Cementitious Materials

    OpenAIRE

    Huang, H

    2014-01-01

    Concrete is a brittle composite cementitious material that easily fractures under tensile loading. Microcracks can appear throughout the concrete prior to application of any load because of temperature-induced strain and autogenous and drying shrinkage. There is no doubt that these cracks provide preferential access for aggressive agents to penetrate into the concrete, probably causing corrosion of reinforcement steel and degradation of concrete. As a result, the service life of reinforced co...

  7. New insights into autogenous self-healing with NMR tests

    OpenAIRE

    Huang, H; Ye, Guang; Pel, L.

    2015-01-01

    Concrete is a brittle composite cementitious material that easily fractures under tensile loading. Microcracks can appear throughout the concrete prior to application of any load because of temperature-induced strain and autogenous and drying shrinkage. There is no doubt that these cracks provide preferential access for aggressive agents to penetrate into the concrete, probably causing corrosion of reinforcement steel and degradation of concrete. As a result, the service life of reinforced co...

  8. Reorganization of the brain and heart rhythm during autogenic meditation

    OpenAIRE

    Dae-Keun Kim; Jyoo-Hi Rhee; Seung Wan Kang

    2014-01-01

    The underlying changes in heart coherence that are associated with reported EEG changes in response to meditation have been explored. We measured EEG and heart rate variability (HRV) before and during autogenic meditation. Fourteen subjects participated in the study. Heart coherence scores were significantly increased during meditation compared to the baseline. We found near significant decrease in high beta absolute power, increase in alpha relative power and significant increases in lower(a...

  9. Combined bone grafting: an alternative method for bone healing stimulation

    International Nuclear Information System (INIS)

    The most provocative problem in bone grafting is the effectiveness of healing of the graft. When you use the heterogenous bone graft, it may take one or more than two years for consolidation and union depends on the graft quality and the situation of surrounding blood supply. In our preliminary report seven cases of freeze-dried heterogenous bone graft from the Bangkok Biomaterial Center were mixed with autogenous iliac bone graft from the patient in the ratio of 3:1. After that the healing was checked by clinical examination and X-ray in the periodic follow up. The causes of bone lost are post evacuation of benign bone tumor and post infection of bone after trauma. The result of bony union could be tested by clinical examination and showed in the X-ray films as early as 3 months post grafting

  10. The treatment of recalcitrant post-traumatic nightmares with autogenic training and autogenic abreaction: a case study.

    Science.gov (United States)

    Sadigh, M R

    1999-09-01

    Recurrent and frightening dreams are commonly experienced by patients who suffer from post-traumatic stress disorder after a motor vehicle accident. Such nocturnal episodes, if left untreated, can result in the experience of severe distress with physical, emotional, and psychophysiological concomitant. The present single-case study investigated the effects of the standard autogenic exercises and autogenic abreaction in reducing the frequency and severity of post-traumatic nightmares in a survivor of a car crash. The patient was also instructed in two additional organ-specific formulas in order to improve her sleep. The results of the study showed that the interventions were successful in effectively treating the patient's distressing nightmares. Follow-up data suggested that the treatment effects persisted after the termination of therapy. Suggestions for future investigations are discussed. PMID:10652639

  11. Autogenous osteochondral ''plug'' transfer for the treatment of focal chondral defects: postoperative MR appearance with clinical correlation

    International Nuclear Information System (INIS)

    Objective: To describe the MR appearance following autogenous osteochondral ''plug'' transfer for the treatment of focal chondral defects of the knee. Design and patients: Twenty-nine 1.5-T MR knee studies including dynamic gadolinium enhancement were performed on 21 patients following autogenous osteochondral ''plug'' transfer. Three musculoskeletal radiologists retrospectively reviewed images to evaluate graft and donor site appearance and MR findings were correlated with clinical outcomes. Results: MR images demonstrated graft protuberance (n=12/21; range 1-2 mm), depression (n=2/21; range 1 mm), and surface incongruity: mild (n=17/21), moderate (n=2/21), marked (n=1/21). The T2 signal of graft cartilage was similar to that of adjacent cartilage in 25 of 29 examinations, and increased in four. Graft cartilage thickness relative to adjacent cartilage was <50% in six patients, 50-100% in 15. Graft enhancement in bone was absent at 2 weeks, but present at between 4 and 6 weeks following surgery. All patients had clinical follow-up examinations and knee outcome survey scores were obtained in 15 patients with follow-up greater than 3 months after surgery. All patients demonstrated the expected short-term progressive clinical improvement. Conclusion: MR images reveal a wide range of appearances following osteochondral ''plug'' transfer. Minor variations in graft orientation and surface congruity do not result in adverse clinical outcome in the short term. (orig.)

  12. Autogenous shrinkage in high-performance cement paste: An evaluation of basic mechanisms

    DEFF Research Database (Denmark)

    Lura, Pietro; Jensen, Ole Mejlhede; van Breugel, Klaas

    2003-01-01

    In this paper, various mechanisms Suggested to cause autogenous shrinkage are presented. The mechanisms are evaluated from the point of view of their soundness and applicability to quantitative modeling of autogenous shrinkage. The capillary tension approach is advantageous, because it has a sound...

  13. Autogenous Regulation of Splicing of the Transcript of a Yeast Ribosomal Protein Gene

    Science.gov (United States)

    Dabeva, Mariana D.; Post-Beittenmiller, Martha A.; Warner, Jonathan R.

    1986-08-01

    The gene for a yeast ribosomal protein, RPL32, contains a single intron. The product of this gene appears to participate in feedback control of the splicing of the intron from the transcript. This autogenous regulation of splicing provides a striking analogy to the autogenous regulation of translation of ribosomal proteins in Escherichia coli.

  14. Autogenous regulation of splicing of the transcript of a yeast ribosomal protein gene.

    OpenAIRE

    Dabeva, M. D.; Post-Beittenmiller, M A; Warner, J R

    1986-01-01

    The gene for a yeast ribosomal protein, RPL32, contains a single intron. The product of this gene appears to participate in feedback control of the splicing of the intron from the transcript. This autogenous regulation of splicing provides a striking analogy to the autogenous regulation of translation of ribosomal proteins in Escherichia coli.

  15. Adjuvant auricular electroacupuncture and autogenic training in rheumatoid arthritis: a randomized controlled trial. Auricular acupuncture and autogenic training in rheumatoid arthritis

    DEFF Research Database (Denmark)

    Bernateck, M; Becker, M; Schwake, C;

    2008-01-01

    BACKGROUND: In contrast to psychological interventions the usefulness of acupuncture as an adjuvant therapy in rheumatoid arthritis (RA) has not yet been demonstrated. OBJECTIVE: The efficacy of auricular electroacupuncture (EA) was directly compared with autogenic training (AT). METHODS: Patients...

  16. Autogenic-Feedback Training Exercise (AFTE) Method and System

    Science.gov (United States)

    Cowings, Patricia S. (Inventor)

    1997-01-01

    The Autogenic-Feedback Training Exercise (AFTE) method of the present invention is a combined application of physiologic and perceptual training techniques. such as autogenic therapy and biofeedback. This combined therapy approach produces a methodology that is appreciably more effective than either of the individual techniques used separately. The AFTE method enables sufficient magnitude of control necessary to significantly reduce the behavioral and physiologic reactions to severe environmental stressors. It produces learned effects that are persistent over time and are resistant to extinction and it can be administered in a short period of time. The AFTE method may be used efficiently in several applications, among which are the following: to improve pilot and crew performance during emergency flying conditions; to train people to prevent the occurrence of nausea and vomiting associated with motion and sea sickness, or morning sickness in early pregnancy; as a training method for preventing or counteracting air-sickness symptoms in high-performance military aircraft; for use as a method for cardiovascular training, as well as for multiple other autonomic responses, which may contribute to the alleviation of Space Motion Sickness (SMS) in astronauts and cosmonauts; training people suffering from migraine or tension headaches to control peripheral blood flow and reduce forehead and/or trapezius muscle tension; training elderly people suffering from fecal incontinence to control their sphincter muscles; training cancer patients to reduce the nauseagenic effects of chemotherapy; and training patients with Chronic Intestinal Pseudo-obstruction (CIP).

  17. The outcome of intraoral onlay block bone grafts on alveolar ridge augmentations: A systematic review

    OpenAIRE

    Aloy Prósper, Amparo; Peñarrocha Oltra, David; Peñarrocha Diago, María; Peñarrocha Diago, Miguel

    2015-01-01

    Aim: The purpose of this study was to systematically review clinical studies examining the survival and success rates of implants placed with intraoral onlay autogenous bone grafts to answer the following question: do ridge augmentations procedures with intraoral onlay block bone grafts in conjunction with or prior to implant placement influence implant outcome when compared with a control group (guided bone regeneration, alveolar distraction, native bone or short dental implants.)? Material ...

  18. Osteogenic Matrix Cell Sheets Facilitate Osteogenesis in Irradiated Rat Bone

    Directory of Open Access Journals (Sweden)

    Yoshinobu Uchihara

    2015-01-01

    Full Text Available Reconstruction of large bone defects after resection of malignant musculoskeletal tumors is a significant challenge in orthopedic surgery. Extracorporeal autogenous irradiated bone grafting is a treatment option for bone reconstruction. However, nonunion often occurs because the osteogenic capacity is lost by irradiation. In the present study, we established an autogenous irradiated bone graft model in the rat femur to assess whether osteogenic matrix cell sheets improve osteogenesis of the irradiated bone. Osteogenic matrix cell sheets were prepared from bone marrow-derived stromal cells and co-transplanted with irradiated bone. X-ray images at 4 weeks after transplantation showed bridging callus formation around the irradiated bone. Micro-computed tomography images at 12 weeks postoperatively showed abundant callus formation in the whole circumference of the irradiated bone. Histology showed bone union between the irradiated bone and host femur. Mechanical testing showed that the failure force at the irradiated bone site was significantly higher than in the control group. Our study indicates that osteogenic matrix cell sheet transplantation might be a powerful method to facilitate osteogenesis in irradiated bones, which may become a treatment option for reconstruction of bone defects after resection of malignant musculoskeletal tumors.

  19. Autogenous Shrinkage of High Strength Lightweight Aggregate Concrete

    Institute of Scientific and Technical Information of China (English)

    DING Qingjun; TIAN Yaogang; WANG Fazhou; ZHANG Feng; HU Shuguang

    2005-01-01

    The characteristic of autogenous shrinkage ( AS ) and its effect on high strength lightweight aggregate concrete (HSLAC) were studied. The experimental results show that the main shrinkage of high strength concrete is AS and the amount of cement can affect the AS of HSLAC remarkably. At the early stage the AS of HSLAC is lower than that of high strength normal concrete, but it has a large growth at the later stage. The AS of high strength normal concrete becomes stable at 90d age, but HSLAC still has a high AS growth. It is found that adjusting the volume rate of lightweight aggregate, mixing with a proper dosage of fly ash and raising the water saturation degree of lightweight aggregate can markedly reduce the AS rate of HSLAC.

  20. Autogenic reaction synthesis of photocatalysts for solar fuel generation

    Energy Technology Data Exchange (ETDEWEB)

    Ingram, Brian J.; Pol, Vilas G.; Cronauer, Donald C.; Ramanathan, Muruganathan

    2016-04-19

    In one preferred embodiment, a photocatalyst for conversion of carbon dioxide and water to a hydrocarbon and oxygen comprises at least one nanoparticulate metal or metal oxide material that is substantially free of a carbon coating, prepared by heating a metal-containing precursor compound in a sealed reactor under a pressure autogenically generated by dissociation of the precursor material in the sealed reactor at a temperature of at least about 600.degree. C. to form a nanoparticulate carbon-coated metal or metal oxide material, and subsequently substantially removing the carbon coating. The precursor material comprises a solid, solvent-free salt comprising a metal ion and at least one thermally decomposable carbon- and oxygen-containing counter-ion, and the metal of the salt is selected from the group consisting of Mn, Ti, Sn, V, Fe, Zn, Zr, Mo, Nb, W, Eu, La, Ce, In, and Si.

  1. Nanocomposites and bone regeneration

    Science.gov (United States)

    James, Roshan; Deng, Meng; Laurencin, Cato T.; Kumbar, Sangamesh G.

    2011-12-01

    This manuscript focuses on bone repair/regeneration using tissue engineering strategies, and highlights nanobiotechnology developments leading to novel nanocomposite systems. About 6.5 million fractures occur annually in USA, and about 550,000 of these individual cases required the application of a bone graft. Autogenous and allogenous bone have been most widely used for bone graft based therapies; however, there are significant problems such as donor shortage and risk of infection. Alternatives using synthetic and natural biomaterials have been developed, and some are commercially available for clinical applications requiring bone grafts. However, it remains a great challenge to design an ideal synthetic graft that very closely mimics the bone tissue structurally, and can modulate the desired function in osteoblast and progenitor cell populations. Nanobiomaterials, specifically nanocomposites composed of hydroxyapatite (HA) and/or collagen are extremely promising graft substitutes. The biocomposites can be fabricated to mimic the material composition of native bone tissue, and additionally, when using nano-HA (reduced grain size), one mimics the structural arrangement of native bone. A good understanding of bone biology and structure is critical to development of bone mimicking graft substitutes. HA and collagen exhibit excellent osteoconductive properties which can further modulate the regenerative/healing process following fracture injury. Combining with other polymeric biomaterials will reinforce the mechanical properties thus making the novel nano-HA based composites comparable to human bone. We report on recent studies using nanocomposites that have been fabricated as particles and nanofibers for regeneration of segmental bone defects. The research in nanocomposites, highlight a pivotal role in the future development of an ideal orthopaedic implant device, however further significant advancements are necessary to achieve clinical use.

  2. PECULIARITIES OF APPLICATION THE METHOD OF AUTOGENIC TRAINING IN THE CORRECTION OF EATING BEHAVIOR

    OpenAIRE

    Shebanova, Vitaliya

    2014-01-01

    The article presented peculiarities of applying the method of autogenic training in the correction of eating disorders. Described stages of correction work with desadaptive eating behavior. Author makes accent on the rules self-assembly formula intentions.

  3. Adjuvant auricular electroacupuncture and autogenic training in rheumatoid arthritis: a randomized controlled trial

    DEFF Research Database (Denmark)

    Bernateck, M.; Becker, M.; Schwacke, C.;

    2008-01-01

    BACKGROUND: In contrast to psychological interventions the usefulness of acupuncture as an adjuvant therapy in rheumatoid arthritis (RA) has not yet been demonstrated. OBJECTIVE: The efficacy of auricular electroacupuncture (EA) was directly compared with autogenic training (AT). METHODS: Patient...

  4. Mesocosmic study on autogenous shrinkage of concrete with consideration of effects of temperature and humidity

    OpenAIRE

    Hai, Yan; Yue-ming ZHU

    2009-01-01

    A study on the autogenous shrinkage (AS) of concrete from a mesocosmic perspective was carried out using numerical simulation technology. The temperature history and the autogenous relative humidity (ARH), two factors that have been shown to have occasional influence on this process in previous studies, were introduced into this study. According to these concepts, a program for simulation of the temperature field, humidity field, and stress field based on the equivalent age method and a fully...

  5. The use of autogenous fascia lata to correct lid and orbital deformities.

    OpenAIRE

    Flanagan, J C; Campbell, C. B.

    1981-01-01

    Autogenous and homologous fascia lata have been used to correct many problems in ophthalmic surgery. This paper has described the use of autogenous fascia late to correct lid retraction secondary to thyroid ophthalmopathy, cicatricial entropion and extruding orbital implants. The surgical procedures have been briefly discussed, as well as the presentation of one clinical example of each procedure the pathologic and immunologic aspects of fascia lata grafts will be reported at a later date.

  6. Eyelid-associated complications after autogenous fat injection for cosmetic forehead augmentation

    OpenAIRE

    Paik, Ji-Sun; Cho, Won-Kyung; Park, Gyeong-Sin; Yang, Suk-Woo

    2013-01-01

    Background We report two cases of unilateral upper eyelid swelling with multiple small lumps as an unusual complication of autogenous fat injection for cosmetic forehead augmentation. Case presentation Two female patients were referred to our clinic for unusual unilateral eyelid swelling, with multiple small lumps. The duration of symptoms differed in each case, but both patients had a history of autogenous fat injection for cosmetic forehead augmentation at a local plastic surgery clinic. Th...

  7. Effect of mineral filler type on autogenous shrinkage of self-compacting concrete

    OpenAIRE

    Craeye, Bart; De Schutter, Geert; Desmet, Bram; Vantomme, John; Heirman, Gert; Vandewalle, Lucie; Cizer, Özlem; AGGOUN, S.; E. H. Kadri

    2010-01-01

    Based on an experimental programme, including autogenous shrinkage tests on concrete, ultrasonic monitoring of fresh concrete, and mercury intrusion porosimetry, the influence of the filler type on the autogenous shrinkage of self-compacting concrete has been investigated. The onset of percolating structure formation (time zero) is influenced by the filler type due to a possible accelerating effect of the filler on the cement hydration. Limestone filler accelerates the hydration process, and ...

  8. The influence of granulation on lightweight aggregate on early autogenous shrinkage of high strength concrete

    OpenAIRE

    Maleš, Dijana

    2013-01-01

    Early autogenous shrinkage of high strength concretes is relatively large. It can be reduced by using internal water reservoirs. Lightweight aggregate was used for internal water reservoir. 12% of aggregate was replaced with pre-soaked lightweight aggregate in the concrete mixture. On the basis of experiments in the graduation thesis we studied the influence of granulation of lightweight aggregate on early autogenous shrinkage. The shrinkage was measured electronically during the first day. I...

  9. Mandibular reconstruction using bone allografts

    International Nuclear Information System (INIS)

    Further understanding of bone healing mechanisms, bone physiology and bone biology, transplantation immunology, and development of Tissue Banking procedures has enabled oral and maxillofacial surgeons to reconstruct even the most difficult bony defects successfully with the preserved allogeneic bone implant. Although it had been known that bone allografts were clinically effective, its application has not been widespread until the reports of Inclan (I 942), Hyatt and Butler (I 950), and Wilson (I 95 1). Tissue Banking provides the surgeon with a readily available, relatively inexpensive, and relatively safe selection of allogeneic bone for clinical use. Now autogenous bone and allogeneic bone implants present a wide variety of surgical options to surgeons, whether used separately or in combination. The surgeons are able to make judicious and fruitful choices, only with a thorough knowledge of the above-mentioned biological principles and skillful techniques. Many kinds of bone grafting techniques have been tried for reconstructing defective osseous tissues of the oral and maxillofacial region, though they have varying degrees of success. The osseous defects which require grafting include those of various size, shape, position, or amount. Unlike autogenous grafts, whose function is to provide osteogenic cells, allografts are purely passive, offering only a matrix for the inductive phase of bone healing. The condition of the recipient bed is of primary importance, because the host must produce all of the essential elements for the bone allograft to become incorporated. Depending on the processing methods of the allogeneic bone, the bone graft materials have different qualities, different healing potentials and different indications. Proper selection of grafts and surgical techniques requires an understanding of graft immunology and the mechanisms of graft healing. The surgeons should know about the biological principles to raise the clinical success rate

  10. Utilization of Guided Bone Regeneration Techniqes in Treatment of a Single Tooth Missing with Implant Supported Crown

    OpenAIRE

    Adamczyk, E.; Gladkowski, J.; Machnikowski, I.; Mierzwinska, E.; Spiechowicz, E.; Feder, T.; Wojtowicz, A.; Matenko, D.; Ciechowicz, K.

    2002-01-01

    Guided bone regeneration is developing very dynamically in dental surgery and in implantology. It relies on building up bone in places where it is lacking, utilizing a variety of grafting materials. Methods of guided bone regeneration utilize biological materials or synthetic specimens. The use of autogenous platelets rich plasma derived in the thromboforetic process (COBE spectra system) allows the employment of growth factors, which blood platelets contain in the formation of new bone tissu...

  11. Untangling climatic and autogenic signals in peat records

    Science.gov (United States)

    Morris, Paul J.; Baird, Andrew J.; Young, Dylan M.; Swindles, Graeme T.

    2016-04-01

    Raised bogs contain potentially valuable information about Holocene climate change. However, autogenic processes may disconnect peatland hydrological behaviour from climate, and overwrite and degrade climatic signals in peat records. How can genuine climate signals be separated from autogenic changes? What level of detail of climatic information should we expect to be able to recover from peat-based reconstructions? We used an updated version of the DigiBog model to simulate peatland development and response to reconstructed Holocene rainfall and temperature reconstructions. The model represents key processes that are influential in peatland development and climate signal preservation, and includes a network of feedbacks between peat accumulation, decomposition, hydraulic structure and hydrological processes. It also incorporates the effects of temperature upon evapotranspiration, plant (litter) productivity and peat decomposition. Negative feedbacks in the model cause simulated water-table depths and peat humification records to exhibit homeostatic recovery from prescribed changes in rainfall, chiefly through changes in drainage. However, the simulated bogs show less resilience to changes in temperature, which cause lasting alterations to peatland structure and function and may therefore be more readily detectable in peat records. The network of feedbacks represented in DigiBog also provide both high- and low-pass filters for climatic information, meaning that the fidelity with which climate signals are preserved in simulated peatlands is determined by both the magnitude and the rate of climate change. Large-magnitude climatic events of an intermediate frequency (i.e., multi-decadal to centennial) are best preserved in the simulated bogs. We found that simulated humification records are further degraded by a phenomenon known as secondary decomposition. Decomposition signals are consistently offset from the climatic events that generate them, and decomposition

  12. ANEURYSMAL BONE CYST OF THE CLAVICLE IN CHILDREN (CLINICAL CASES AND TREATMENT

    Directory of Open Access Journals (Sweden)

    Timur Faizovich Zubairov

    2014-09-01

    Full Text Available The purpose. To examine the results of the treatment of children with aneurysmal cyst of the clavicle. Material and methods. The results of examination and treatment of patients aged 16 and 17 years with a diagnosis of aneurysmal cyst of the clavicle. All patients underwent surgical treatment with the ABC stage delimitation. We used a surgical technique, which consists in open removement of the abnormal tissue with replacement of the bone defect with bone-plastic material or autogenous bone from the iliac crest. Conclusions. The method of treatment of aneurysmal bone cyst of the clavicle must be individualized depending on the location, aggressiveness and extent of the lesion. The use bone-plastic material or autogenous bone from the iliac crest restore the structural integrity of a compromised clavicle gives good results in the observation period of up to 2 years.

  13. The influence of superabsorbent polymers on the autogenous shrinkage properties of cement pastes with supplementary cementitious materials

    DEFF Research Database (Denmark)

    Snoeck, D.; Jensen, Ole Mejlhede; De Belie, N.

    2015-01-01

    Fly ash and blast-furnace slag containing binders are frequently used in the construction industry and it is important to know the extent of autogenous shrinkage and its (ideal) mitigation by superabsorbent polymers in these systems as a function of their age. In this paper, the autogenous...... shrinkage was determined by manual and automated shrinkage measurements. Autogenous shrinkage was reduced in cement pastes with the supplementary cementitious materials versus Portland cement pastes. At later ages, the rate of autogenous shrinkage is higher due to the pozzolanic activity. Internal curing by...... means of superabsorbent polymers is successful, independent of this long term higher rate of shrinkage in mixtures with supplementary cementitious materials....

  14. Autogenous training--an anxiolytic and a factor contributing to the improvement of the quality of life.

    Science.gov (United States)

    Gruden, V

    1999-06-01

    Autogenous training in its narrow sense of meaning belongs to the group of supportive psychotherapeutic techniques. In fact, it is an autosuggestive relaxation. Autogenous training has been for decades successfully used as prevention to anxious reactions. Since anxiety is an etiological factor of numerous psychic and psychosomatic disturbances, positive implications of autogenous training have been considerably broadened. Life without anxiety belongs to a more qualitative form of life. Autogenous training directs the trainee towards introspection and self-analysis. Self-respect (self-esteem) is the consequence of our own work on ourselves. PMID:10402736

  15. Effects of liquid nitrogen cryotherapy and bone grafting on artificial bone defects in minipigs: a preliminary study.

    Science.gov (United States)

    Pogrel, M A; Regezi, J A; Fong, B; Hakim-Faal, Z; Rohrer, M; Tran, C; Schiff, T

    2002-06-01

    Liquid nitrogen cryotherapy has been advocated as an adjunct in the enucleation and curettage of locally aggressive lesions of the jaws. Simultaneous autogenous bone grafting has also been advocated to accelerate bone formation and reduce morbidity. There is, however, relatively little scientific basis for either of these hypotheses. In this study, nine Yucatan minipigs had artificial defects created in the mandible, which were treated with liquid nitrogen spray. Half of the defects were grafted with autogenous bone from the chin and half were closed primarily. Two animals were sacrificed 3 days postoperatively to measure the width of necrosis and the rest were sacrificed at 3 months to assess healing and new bone formation. It was found that drilling the artificial defects alone caused bone necrosis for a mean depth of 0.09 mm. Liquid nitrogen cryospray caused a mean depth of bone necrosis of 0.82 mm (range 0.51-1.52 mm). The defects that were bone grafted healed well clinically. Defects not bone grafted showed a 50% rate of wound breakdown and sequestrum formation with delayed healing. Vital staining showed a non-significantly greater rate of bone formation in the grafted defects. Digitally superimposed radiography showed a non-significantly greater bone density in the non-grafted defects at 3 months postoperatively. It appears that liquid nitrogen cryospray does devitalize an area of bone around defects in the mandible. The width of necrosis is usually less than 1 mm and subsequent healing is enhanced by autogenous bone grafting. This has clinical implications. PMID:12190137

  16. Frontal Bone Remodeling for Gender Reassignment of the Male Forehead: A Gender-Reassignment Surgery

    OpenAIRE

    Hoenig, Johannes

    2011-01-01

    Gender-reassignment therapy, especially for reshaping of the forehead, can be an effective treatment to improve self-esteem. Contouring of the cranial vault, especially of the forehead, still is a rarely performed surgical procedure for gender reassignment. In addition to surgical bone remodeling, several materials have been used for remodeling and refinement of the frontal bone. But due to shortcomings of autogenous bone material and the disadvantages of polyethylene or methylmethacrylate, h...

  17. Histological Features and Biocompatibility of Bone and Soft Tissue Substitutes in the Atrophic Alveolar Ridge Reconstruction

    OpenAIRE

    Carlo Maiorana; Mario Beretta; Davide Rancitelli; Giovanni Battista Grossi; Marco Cicciù; Alan Scott Herford

    2016-01-01

    The reconstruction of the atrophic alveolar ridges for implant placement is today a common procedure in dentistry daily practice. The surgical reconstruction provides for the optimization of the supporting bone for the implants and a restoration of the amount of keratinized gingiva for esthetic and functional reasons. In the past, tissue regeneration has been performed with autogenous bone and free gingival or connective tissue grafts. Nowadays, bone substitutes and specific collagen matrix a...

  18. Bone-Marrow Storage and Transplantation

    International Nuclear Information System (INIS)

    The authors present some results from their experiments on bone-marrow storage and transplantation. The main problems with preservation of stored bone marrow are the duration, temperature, adjuvant substances and the significance of viability tests during the conservation processes. The results showed that: • Storage of bone marrow at +4eC produces a progressive decrease in its restoring capacity versus storage time. • While bone marrow stored for 24 h is able to restore 100% of dogs lethally irradiated with 600 rad, after 10 days of storage only 20% of the animals can be restored. • No correlation exists between the actual survival of dogs and that calculated by dye exclusion tests, which indicate a rather high (70%) viability, even after 10 days bone-marrow storage at +4°C. • DNA degradation (depolymerization) measurements of the bone marrow may be used as a supplementary test for checking the viability or restoration potency of bone-marrow cells after storage. • In the freezing process, the optimum contact time between glycerol and the bone-marrow cells is 15 min. Results of experiments regarding certain bone-marrow transplantation problems showed that: • The best time to administer bone marrow is between 24 and 48 h after irradiation. • No survivors were obtained with dogs lethally irradiated with 600 rad by administering autogenic or allogenic DNA extracted from bone marrow, spleen or liver. • Histocompatibility related to sex may play an important role in the bone-marrow graft. The lowest survival of C57BL mice was obtained when the donors were males and the recipients females. • In radioprotection with foetal haemocytopoietic tissues, the donor's age represents one of the main factors. The best results were obtained in experiments on rats, with 19- to 20-day foetal liver (period of complete and maximum haemocytopoietic activity). The tissues mentioned below may be connected with the appearance of certain typical signs of secondary syndrome

  19. Brain structural alterations in obsessive-compulsive disorder patients with autogenous and reactive obsessions.

    Directory of Open Access Journals (Sweden)

    Marta Subirà

    Full Text Available Obsessive-compulsive disorder (OCD is a clinically heterogeneous condition. Although structural brain alterations have been consistently reported in OCD, their interaction with particular clinical subtypes deserves further examination. Among other approaches, a two-group classification in patients with autogenous and reactive obsessions has been proposed. The purpose of the present study was to assess, by means of a voxel-based morphometry analysis, the putative brain structural correlates of this classification scheme in OCD patients. Ninety-five OCD patients and 95 healthy controls were recruited. Patients were divided into autogenous (n = 30 and reactive (n = 65 sub-groups. A structural magnetic resonance image was acquired for each participant and pre-processed with SPM8 software to obtain a volume-modulated gray matter map. Whole-brain and voxel-wise comparisons between the study groups were then performed. In comparison to the autogenous group, reactive patients showed larger gray matter volumes in the right Rolandic operculum. When compared to healthy controls, reactive patients showed larger volumes in the putamen (bilaterally, while autogenous patients showed a smaller left anterior temporal lobe. Also in comparison to healthy controls, the right middle temporal gyrus was smaller in both patient subgroups. Our results suggest that autogenous and reactive obsessions depend on partially dissimilar neural substrates. Our findings provide some neurobiological support for this classification scheme and contribute to unraveling the neurobiological basis of clinical heterogeneity in OCD.

  20. Numerical model predictions of autogenic fluvial terraces and comparison to climate change expectations

    Science.gov (United States)

    Limaye, Ajay B. S.; Lamb, Michael P.

    2016-03-01

    Terraces eroded into sediment (alluvial) and bedrock (strath) preserve an important history of river activity. River terraces are thought to form when a river switches from a period of slow vertical incision and valley widening to fast vertical incision and terrace abandonment. Consequently, terraces are often interpreted to reflect changing external drivers including tectonics, sea level, and climate. In contrast, the intrinsic unsteadiness of lateral migration in rivers may generate terraces even under constant rates of vertical incision without external forcing. To explore this mechanism, we simulate landscape evolution by a vertically incising, meandering river and isolate the age and geometry of autogenic river terraces. Modeled autogenic terraces form for a wide range of lateral and vertical incision rates and are often paired and longitudinally extensive for intermediate ratios of vertical-to-lateral erosion rate. Autogenic terraces have a characteristic reoccurrence time that scales with the time for relief generation. There is a preservation bias against older terraces due to reworking of previously visited parts of the valley. Evolving, spatial differences in bank strength between bedrock and sediment reduce terrace formation frequency and length, favor pairing, and can explain sublinear terrace margins at valley boundaries. Age differences and geometries for modeled autogenic terraces are consistent, in cases, with natural terraces and overlap with metrics commonly attributed to terrace formation due to climate change. We suggest a new phase space of terrace properties that may allow differentiation of autogenic terraces from terraces formed by external drivers.

  1. Executive functions and memory in autogenous and reactive subtype of obsessive-compulsive disorder patients.

    Science.gov (United States)

    Aydın, Pinar Cetinay; Koybasi, Gulperi Putgul; Sert, Engin; Mete, Levent; Oyekcin, Demet Gulec

    2014-05-01

    There are concurrently with different results of studies about cognitive functions of Obsessive-Compulsive Disorder (OCD), impairment in non-verbal memory and executive functioning in OCD, has shown consistent results in several studies. In this study, 62 OCD patients and 40 healthy controls were participated. Firstly, cognitive functions of OCD group and healthy control group were compared in terms of scores in Stroop Test, Wisconsin Cart Sorting Test (WCST), Auditory Consonant Trigram Test (ACTT), Controlled Word Association Test (CWAT), Rey Auditory Verbal Learning Test (RAVLT), Digit Span Test (DST). And then, two patient groups of OCD patients (patients with autogenous obsessions and patients with reactive obsessions) were compared in terms of the scores of same tests, with a hypothesis that claims, cognitive functions of patients with autogenous obsessions, who shown schizotypal personality features and thought disorder in higher ratio, will show more impairment than cognitive functions of patients with reactive obsessions. Significant impairment was found in OCD patients in terms of Stroop test and WCST scores when compared to scores of healthy controls. There was no difference pointed out between cognitive functions of patients with autogenous obsessions and reactive obsessions. Due to limited number of patients with autogenous obsessions in current study, any future research with greater sample size will be helpful to explain the cognitive functions in OCD with autogenous and reactive obsessions. PMID:24582324

  2. Aspects of energy reduction by autogenous copper production in the copper smelting plant Bor

    International Nuclear Information System (INIS)

    This work presents a comparative analysis of the energy consumption during copper production by the “standard” procedure (roasting in a fluo–solid reactor and smelting in a reverberatory furnace) in the Smelting Plant in Bor with modern autogenous procedures. All forms of expended energy were reduced to primary energy or to the same energy form, i.e., to the energy equivalent of the process (EEP), the raw material and the process materials. In addition, the energy equivalent of the process and waste products (water vapour, thermal energy and similar) were balanced. To complete the consumption of all energy generating products in copper production, they were reduced to conditional fuel (coal equivalent = 29.3 MJ/kg). Additionally, this study suggests replacement of the existing technology by an appropriate autogenous procedure and considers the prospects for further development of mining and metallurgy in Bor. Estimates of development perspectives for copper production should be comprehensive, based on complete and relevant data, as well as on real considerations of future development in world production. -- Highlights: ► “Standard” autogenous copper production in the Smelting Plant, Bor, Serbia. ► Comparation of energy consumption in “standard” with other autogenous procedures. ► All forms of energy are reduced to energy equivalent and conditional fuel. ► Replacement of existing technology with the appropriate autogenous procedure. ► Perspectives of further development of mining and metallurgy in Bor.

  3. Health hazards of cement dust

    International Nuclear Information System (INIS)

    ven in the 21st century, millions of people are working daily in a dusty environment. They are exposed to different types of health hazards such as fume, gases and dust, which are risk factors in developing occupational disease. Cement industry is involved in the development of structure of this advanced and modern world but generates dust during its production. Cement dust causes lung function impairment, chronic obstructive lung disease, restrictive lung disease, pneumoconiosis and carcinoma of the lungs, stomach and colon. Other studies have shown that cement dust may enter into the systemic circulation and thereby reach the essentially all the organs of body and affects the different tissues including heart, liver, spleen, bone, muscles and hairs and ultimately affecting their micro-structure and physiological performance. Most of the studies have been previously attempted to evaluate the effects of cement dust exposure on the basis of spirometry or radiology, or both. However, collective effort describing the general effects of cement dust on different organ and systems in humans or animals, or both has not been published. Therefore, the aim of this review is to gather the potential toxic effects of cement dust and to minimize the health risks in cement mill workers by providing them with information regarding the hazards of cement dust. (author)

  4. Autogenous osteochondral ''plug'' transfer for the treatment of focal chondral defects: postoperative MR appearance with clinical correlation

    Energy Technology Data Exchange (ETDEWEB)

    Sanders, T.G. [Dept. of Radiology, Univ. of Texas, San Antonio (United States); Dept. of Radiology, Wilford Hall Medical Center, Lackland AFB, Texas (United States); Dept. of Radiology, Lackland AFB, TX (United States); Mentzer, K.D. [Dept. of Orthopaedics, Wilford Hall USAF Medical Center, Lackland AFB, TX (United States); Miller, M.D. [Dept. of Orthopaedic Surgery, Univ. of Virginia, Charlottesville (United States); Morrison, W.B. [Thomas Jefferson Univ., Philadelphia, PA (United States). Dept. of Radiology; Campbell, S.E. [Dept. of Radiology, Wilford Hall USAF Medical Center, Lackland AFB, TX (United States); Penrod, B.J. [Musculoskeletal Radiology, Brooke Army Medical Center, San Antonio, TX (United States)

    2001-10-01

    Objective: To describe the MR appearance following autogenous osteochondral ''plug'' transfer for the treatment of focal chondral defects of the knee. Design and patients: Twenty-nine 1.5-T MR knee studies including dynamic gadolinium enhancement were performed on 21 patients following autogenous osteochondral ''plug'' transfer. Three musculoskeletal radiologists retrospectively reviewed images to evaluate graft and donor site appearance and MR findings were correlated with clinical outcomes. Results: MR images demonstrated graft protuberance (n=12/21; range 1-2 mm), depression (n=2/21; range 1 mm), and surface incongruity: mild (n=17/21), moderate (n=2/21), marked (n=1/21). The T2 signal of graft cartilage was similar to that of adjacent cartilage in 25 of 29 examinations, and increased in four. Graft cartilage thickness relative to adjacent cartilage was <50% in six patients, 50-100% in 15. Graft enhancement in bone was absent at 2 weeks, but present at between 4 and 6 weeks following surgery. All patients had clinical follow-up examinations and knee outcome survey scores were obtained in 15 patients with follow-up greater than 3 months after surgery. All patients demonstrated the expected short-term progressive clinical improvement. Conclusion: MR images reveal a wide range of appearances following osteochondral ''plug'' transfer. Minor variations in graft orientation and surface congruity do not result in adverse clinical outcome in the short term. (orig.)

  5. The Palatal Bone Block Graft for Onlay Grafting Combined with Maxillary Implant Placement: A Case Series.

    Science.gov (United States)

    Gluckman, Howard; Du Toit, Jonathan; Salama, Maurice

    2016-01-01

    The aim of this study was to introduce an intraoral bone block harvesting technique--the palatal bone block graft (PBBG)--as an alternative harvest site for autogenous bone blocks. The PBBG technique was used to onlay graft esthetic zone defects simultaneous to implant placement in five patients. Measurable objectives were used to evaluate outcomes, and treatment was reassessed at up to 6 years. Defects of the maxilla were successfully grafted with PBBG in all five cases, and tissues remained stable at 1- and 6-year follow-ups. Harvesting an autogenous bone block from the palate is an advantageous, predictable, and reproducible method for augmenting buccofacial defects at implant placement, and may be considered as an alternative to conventional intraoral bone block donor sites when treating the maxilla. PMID:27333009

  6. Comparative fine structure of eggs of autogenous and anautogenous Culex pipiens (Diptera: Culicidae).

    Science.gov (United States)

    Soliman, Belal A; Tewfick, Maha K; Wassim, Nahla M

    2014-12-01

    Culex (Cx.) pipiens is the potential vector human filariasis in Egypt. However, autogenous Cx. pipiens may be less efficient vector of Wuchereria (W.) bancrofti in endemic areas of Egypt compared to anautogenous counterparts. In this study, an attempt was made to differentiate eggs of autogenous and anautogenous Cx. pipiens using scanning electron micrographs. The results indicated that eggs of both species appear to be similar to great extent in surface morphology. Eggs of both forms are black and elongate-oval. Width is greatest at the anterior end. The posterior end is pointed. The micropylar disc is apparent with distinct edge. Exochorionic bridges are angular. Size of both eggs represented by length and width are comparable. In both eggs, length is greater than width. However, eggs of both forms can be distinguished from each other by the exochorionic bridges being longer and thinner in the autogenous eggs than in the anautogenous eggs. PMID:25643517

  7. Experimental Research on the Autogenous Shrinkage of MK High Performance Concrete

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Calcine and mill kaolin were used under agreeable technological conditions to generate matakaolin (MK). The autogenous shrinkage performance of high performance concrete added with MK was researched. It is shown that MK has an effective inhibitory action to early autogenous shrinkage of cement concrete, and the inhibitory action increases with the increase of MK. The autogenous shrinkage values from 24 hours after placement to 56 days are all higher than those of the contrasted concrete, among which, the value of the concrete with 5% MK is the highest. But the total shrinkage values in 56 days are all less than those of the contrasted test pieces. The total contraction after 24 h of placement decreases as the increase of MK, moreover,it is greatly less than that of the contrasted ones.

  8. Bone reconstruction of large defects using bone marrow derived autologous stem cells.

    Science.gov (United States)

    Lucarelli, Enrico; Donati, Davide; Cenacchi, Annarita; Fornasari, Pier Maria

    2004-04-01

    Bone is a tissue that has the ability to heal itself when fractured. Occasionally, a critical defect can be formed when part of the bone is lost or excised, in this case the bone fails to heal and requires bone reconstruction to prevent a non-union defect. Autogenous cancellous bone is the current gold standard treatment in bone loss. Because the amount of autogenous cancellous bone that can be harvested is limited, the expanding need for bone reconstruction is paired by the growth of interest in the discipline of tissue engineering. Labs worldwide are working to provide the right carrier and the right set of cells that, once retransplanted, will ensure bone repair. Several investigators have focused their attention on a subset of autologous non-hematopoietic stem/progenitor cells contained in the adult bone marrow stroma, referred to as stromal stem cells (SSC), as the appropriate cells to be transplanted. The use of autologous cells is facilitated by less stringent ethical and regulatory issues and does not require the patient to be immunologically suppressed. In pre-clinical and clinical protocols of critical defects in which SSC are employed, two approaches are mainly used: in the first, SSC are derived from bone marrow and directly introduced at the lesion site, in the second, SSC are derived from several sites and are expanded ex vivo before being implanted. Both approaches, equally correct in principle, will have to demonstrate, with definitive evidence of their efficacy, their capability of solving a critical clinical problem such as non-union. In this report we outline the difficulties of working with SSC. PMID:15062758

  9. Autogenous temporalis fascia patch graft for porous polyethylene (Medpor) sphere orbital implant exposure

    OpenAIRE

    Sagoo, M S; Olver, J M

    2004-01-01

    Background: Temporalis fascia has been recommended for hydroxyapatite sphere exposure. The aim of this study was to identify potential risk factors for exposure of porous polyethylene (Medpor) sphere implants and evaluate the use of autogenous temporalis fascia as a patch graft for exposure.

  10. Autogenous shrinkage of Ducorit S5R ASTM C 1698-09 test method

    DEFF Research Database (Denmark)

    Damkilde, Lars

    The report deals with experimental measurement of autogenous shrinkage of Ducorit S5R according to the test method ASTM C 1698-09. This test method measures the bulk strain of a sealed cementitious specimen, at constant temperature and not subjected to external forces, from the time of final...

  11. Measurement with corrugated tubes of early-age autogenous shrinkage of cement-based material

    DEFF Research Database (Denmark)

    Tian, Qian; Jensen, Ole Mejlhede

    2009-01-01

    The use of a special corrugated mould enables transformation of volume strain into horizontal, linear strain measurement in the fluid stage. This allows continuous measurement of the autogenous shrinkage of cement-based materials since casting, and also effectively eliminates unwanted influence on...

  12. Autogenous shrinkage in high-performance cement paste: An evaluation of basic mechanisms

    DEFF Research Database (Denmark)

    Lura, Pietro; Jensen, Ole Mejlhede; van Breugel, Klaas

    2003-01-01

    mechanical and thermodynamical basis. Furthermore, this mechanism is easily applicable in a numerical model when dealing with a continuously changing microstructure. In order to test the numerical model, autogenous deformation and internal relative humidity (RH) of a Portland cement paste were measured...

  13. Ultra high performance concrete made with rice husk ash for reduced autogenous shrinkage

    NARCIS (Netherlands)

    Van Breugel, K.; Van Tuan, N.

    2014-01-01

    Ultra High Strength Concrete (UHPC) is generally made with low w/c mixtures and by adding silica fume. Low w/c mixtures, however, exhibit high autogenous shrinkage, while a high amount of silica fume increases the price of these mixtures. For designing ultra high strength mixtures with low autogenou

  14. Silicate minerals for CO2 scavenging from biogas in Autogenerative High Pressure Digestion

    NARCIS (Netherlands)

    Lindeboom, R.E.F.; Ferrer, I.; Weijma, J.; Lier, van J.B.

    2013-01-01

    Autogenerative High Pressure Digestion (AHPD) is a novel concept that integrates gas upgrading with anaerobic digestion by selective dissolution of CO2 at elevated biogas pressure. However, accumulation of CO2 and fatty acids after anaerobic digestion of glucose resulted in pH 3–5, which is incompat

  15. Silicate-doped hydroxyapatite and its promotive effect on bone mineralization

    Science.gov (United States)

    Qiu, Zhi-Ye; Noh, In-Sup; Zhang, Sheng-Min

    2013-03-01

    Bone defect is one of the most common diseases in clinic. Existing therapeutic approaches have encountered many problems, such as lack of autogenous allogeneic bone and immunological rejection to allogeneic implant. Synthetic hydroxyapatite (HA) provided solutions for bone repair, since the HA is the main inorganic component of animals' bone. However, HA has good biocompatibility, but does not possess osteogenic capability, which is of significance for modern bone repair materials. Si is an essential trace element in bone tissue, and it has been demonstrated to be able to promote bone formation. Therefore, silicate-doped hydroxyapatite (Si-HA) may serve as a promising material for bone repair, and promote bone regeneration in the repair. The current review discusses development of Si-HA, focusing on its preparation and characterization, in vitro and in vivo evaluations of the material, positive effect of Si-HA on promoting bone formation in clinical applications, and molecular mechanism investigation of such promotive effect.

  16. Silicate-doped hydroxyapatite and its promotive effect on bone mineralization

    Institute of Scientific and Technical Information of China (English)

    Zhi-Ye QIU; In-Sup NOH; Sheng-Min ZHANG

    2013-01-01

    Bone defect is one of the most common diseases in clinic. Existing therapeutic approaches have encountered many problems, such as lack of autogenous allogeneic bone and immunological rejection to allogeneic implant. Synthetic hydroxyapatite (HA) provided solutions for bone repair, since the HA is the main inorganic component of animals' bone. Although HA has good biocompatibility, but only the limited osteogenic capability, which is of significance for modern bone repair materials. Si is an essential trace element in bone tissue, and it has been demonstrated to be able to promote bone formation. Therefore, silicate-doped hydroxyapatite (Si-HA) may serve as a promising material for bone repair, and promote bone regeneration in the repair. The current review discusses development of Si-HA, focusing on its preparation and characterization, in vitro and in vivo evaluations of the material, positive effect of Si-HA on promoting bone formation in clinical applications, and molecular mechanism investigation of such promotive effect.

  17. Lumbar Incisional Hernia Repair After Iliac Crest Bone Graft

    OpenAIRE

    Do, Michael V.; Richardson, William S.

    2012-01-01

    The iliac crest is a common donor site for autogenous bone grafts. Among the reported complications, lumbar hernias occur infrequently with a reported incidence of 5% to 9%. Surgical repair is advocated secondary to the risk of incarceration or strangulation. Computed tomography is the diagnostic study of choice. Various transabdominal, retroperitoneal, and laparoscopic approaches have been described for the repair of lumbar hernias. We describe a case of successful lumbar incisional hernia r...

  18. Allergies, asthma, and dust

    Science.gov (United States)

    Allergic rhinitis - dust ... make allergies or asthma worse are called triggers. Dust is a common trigger. When your asthma or allergies become worse due to dust, you are said to have a dust allergy. ...

  19. Temperature dependence of autogenous shrinkage of silica fume cement pastes with a very low water–binder ratio

    Energy Technology Data Exchange (ETDEWEB)

    Maruyama, I., E-mail: ippei@dali.nuac.nagoya-u.ac.jp [Graduate School of Environmental Studies, Nagoya University, ES Building, No. 539, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Teramoto, A. [Graduate School of Environmental Studies, Nagoya University, Faculty of Engineering, ES Building, No. 546, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan)

    2013-08-15

    Ultra-high-strength concrete with a large unit cement content undergoes considerable temperature increase inside members due to hydration heat, leading to a higher risk of internal cracking. Hence, the temperature dependence of autogenous shrinkage of cement pastes made with silica fume premixed cement with a water–binder ratio of 0.15 was studied extensively. Development of autogenous shrinkage showed different behaviors before and after the inflection point, and dependence on the temperature after mixing and subsequent temperature histories. The difference in autogenous shrinkage behavior poses problems for winter construction because autogenous shrinkage may increase with decrease in temperature after mixing before the inflection point and with increase in temperature inside concrete members with large cross sections.

  20. Temperature dependence of autogenous shrinkage of silica fume cement pastes with a very low water–binder ratio

    International Nuclear Information System (INIS)

    Ultra-high-strength concrete with a large unit cement content undergoes considerable temperature increase inside members due to hydration heat, leading to a higher risk of internal cracking. Hence, the temperature dependence of autogenous shrinkage of cement pastes made with silica fume premixed cement with a water–binder ratio of 0.15 was studied extensively. Development of autogenous shrinkage showed different behaviors before and after the inflection point, and dependence on the temperature after mixing and subsequent temperature histories. The difference in autogenous shrinkage behavior poses problems for winter construction because autogenous shrinkage may increase with decrease in temperature after mixing before the inflection point and with increase in temperature inside concrete members with large cross sections

  1. Treatment of tibial defect and bone nonunion with limb shortening with external fixator and reconstituted bone xenograft

    Institute of Scientific and Technical Information of China (English)

    王志刚; 刘建; 胡蕴玉; 孟国林; 金格勒; 袁志; 王海强; 戴先文

    2003-01-01

    Objective: To explore the effect of external fixator and reconstituted bone xenograft (RBX) in the treatment of tibial bone defect, tibial bone nonunion and congenital pseudarthrosis of the tibia with limb shortening. Methods: Twenty patients ( 13 males and 7 females) with tibial bone defect, tibial bone nonunion or congenital pseudarthrosis of the tibia with limb shortening were treated with external fixation. Two kinds of external fixators were used: a half ring sulcated external fixator used in 13 patients and a combined external fixator in 7 patients. Foot-drop was corrected at the same time with external fixation in 4 patients. The shortened length of the tibia was in the range of 2-9 cm, with an average of 4.8 cm. For bone grafting, RBX was used in 12 patients, autogenous ilium was used in 3 patients and autogenous fibula was implanted as a bone plug into the medullary canal in 1 case, and no bone graft was used in 4 patients. Results: All the 20 patients were followed-up for 8 months to 7 years, averaging 51 months. Satisfactory function of the affected extremities was obtained. All the shortened extremities were lengthened to the expected length. For all the lengthening area and the fracture sites, bone union was obtained at the last. The average healing time of 12 patients treated with RBX was 4.8 months. Conclusions: Both the half ring sulcated external fixator and the combined external fixator have the advantages of small trauma, simple operation, elastic fixation without stress shielding and non-limitation from local soft tissue conditions, and there is satisfactory functional recovery of affected extremities in the treatment of tibial bone defects, tibial bone nonunion and congenital pseudarthrosis of the tibia combined with limb shortening. RBX has good biocompatibility and does not cause immunological rejections. It can also be safely used in treatment of bone nonunion and has reliable effect to promote bone healing.

  2. Gore-Tex small-vessel angioplasty: A suitable substitute for the use of autogenous saphenous vein grafts

    OpenAIRE

    Garcia-Rinaldi, Raul; Rea, John E.; Gallagher, Michael W.; Laevsky, Marlene J.; Ogburn, Michael; Porter, Robert H.

    1980-01-01

    Autogenous saphenous vein has been the material of choice for small-vessel angioplasty and for circulatory access graft reconstruction. In an effort to conserve autogenous saphenous vein, we used expanded polytetrafluoroethylene (PTFE) grafts in 45 patients over a 12-month period. We used Gore-Tex* to reconstruct 17 circulatory access grafts, 16 carotid arteries, two brachial arteries, seven femoral arteries, and three popliteal anterior or posterior tibial arteries. The indications for recon...

  3. Within Patient Radiological Comparative Analysis of the Performance of Two Bone Graft Extenders Utilized in Posterolateral Lumbar Fusion: A Retrospective Case Series

    OpenAIRE

    Stewart, Geoffrey; Gage, Gary B.; Neidert, Gary; Adkisson, Huston Davis

    2016-01-01

    Two bone graft extenders differing in chemical composition were implanted contralaterally in 27 consecutive patients undergoing instrumented posterolateral lumbar fusion as standard-of-care. Bone marrow aspirate and autogenous bone graft were equally combined either with β-tricalcium phosphate (β-TCP) or a hybrid biomaterial [containing hyaluronic acid (HyA) but lacking a calcium salt] and implanted between the transverse processes. Fusion status on each side of the vertebrae was retrospectiv...

  4. Bone tumor

    Science.gov (United States)

    Tumor - bone; Bone cancer; Primary bone tumor; Secondary bone tumor ... The cause of bone tumors is unknown. They often occur in areas of the bone that grow rapidly. Possible causes include: Genetic defects ...

  5. Bone Grafts

    Science.gov (United States)

    A bone graft transplants bone tissue. Surgeons use bone grafts to repair and rebuild diseased bones in your hips, knees, spine, and sometimes other bones and joints. Grafts can also repair bone loss caused by some ...

  6. Rehabilitation of Patients Following Autogenic Bone-Patellar Tendon-Bone ACL Reconstruction: A 20-Year Perspective

    OpenAIRE

    De Carlo, Mark S.; McDivitt, Ryan

    2006-01-01

    Rehabilitation of patients following anterior cruciate ligament (ACL) reconstruction has undergone remarkable improvements over the past two decades. During this time, ACL research has been at the forefront of many orthopaedic and sports physical therapy clinics. With over 20 years of ACL rehabilitation experience (senior author) and prior collaboration with accelerated ACL rehabilitation pioneer K. Donald Shelbourne, the authors wish to present a unique perspective on the evolution of ACL re...

  7. Effect of Cement Type on Autogenous Deformation of Cement-Based Materials

    DEFF Research Database (Denmark)

    Pietro, Lura; Ye, Guang; van Breugel, Klaas

    2004-01-01

    In this paper, measurements of non-evaporable water content, chemical shrinkage, autogenous deformation, internal relative humidity (RH), pore solution composition, and early-age elastic modulus are presented and discussed. All experiments were performed on Portland cement and blast-furnace slag ......, taking into account the influence of the dissolved salts in the pore solution, 2) the BFS cement paste studied shows pronounced self-desiccation and self-desiccation shrinkage, mainly caused by its very fine pore structure.......In this paper, measurements of non-evaporable water content, chemical shrinkage, autogenous deformation, internal relative humidity (RH), pore solution composition, and early-age elastic modulus are presented and discussed. All experiments were performed on Portland cement and blast-furnace slag...

  8. Combined use of autogenic therapy and biofeedback in training effective control of heart rate by humans

    Science.gov (United States)

    Cowings, P. S.

    1977-01-01

    Experiments were performed on 24 men and women (aged 20-27 yr) in three equal groups who were taught to control their own heart rates by autogenic training and biofeedback under dark and sound-isolated conditions. Group I was parasympathetic dominant, group II was sympathetic dominant, and group III consisted of parasympathetic-dominant subjects and controls who received only biofeedback of their own heart rates. The results corroborate three hypotheses: (1) subjects with para-sympathetic-dominant autonomic profiles perform in a way that is both qualitatively and quantitatively different from subjects with sympathetic-dominant autonomic profiles; (2) tests of interindividual variability yield data relevant to individual performance in visceral learning tasks; and (3) the combined use of autogenic training, biofeedback, and verbal feedback is suitable for conditioning large stable autonomic responses in humans.

  9. Measuring Autogenic Recharge over a Karst Aquifer Utilizing Eddy Covariance Evapotranspiration

    OpenAIRE

    Nico M. Hauwert; John M. Sharp

    2014-01-01

    Autogenic, or direct aquifer recharge can best be measured as the remainder of a water balance utilizing precise measurement of precipitation, evapotranspiration (ET) and runoff. ET is the largest component of a precipitation water balance and can be measured within 5% using an eddy covariance system with Bowen-ratio energy balance corrections. Water balance components of precipitation, evapotranspiration, internal runoff, soil moisture were measured using a eddy covari...

  10. Anatomic study of the lacrimal fossa and lacrimal pathway for bypass surgery with autogenous tissue grafting

    OpenAIRE

    Hai Tao; Zhi-zhong Ma; Hai-Yang Wu; Peng Wang; Cui Han

    2014-01-01

    Purpose: To study the microsurgical anatomy of the lacrimal drainage system and to provide anatomical evidence for transnasal endoscopic lacrimal drainage system bypass surgery by autogenous tissue grafting. Materials and Methods: A total of 20 Chinese adult cadaveric heads in 10% formaldehyde, comprising 40 lacrimal ducts were used. The middle third section of the specimens were examined for the following features: the thickness of the lacrimal fossa at the anterior lacrimal crest, vertical ...

  11. Test rig for early age measurements of the autogenous shrinkage of a concrete

    OpenAIRE

    Boulay, Claude

    2012-01-01

    A test rig designed for autogenous shrinkage measurements of concrete at early age is presented. It allows the recording of the deformations of a specimen protected against the desiccation at a constant temperature. Only one external displacement sensor is used. The specimens are cast in a flexible mould to avoid any friction. The test rig is immersed in a thermo controlled bath. Measurements can start just after the casting of the concrete. A series of four successive tests on the same concr...

  12. Autogenous shrinkage of a self-compacting VHPC in isothermal and realistic temperature conditions

    OpenAIRE

    STAQUET, S; Boulay, C.; D'ALOIA, L; F. TOUTLEMONDE

    2006-01-01

    The autogenous shrinkage development at early age of a Very High Performance Concrete (VHPC) was analyzed in both situations : under standard isothermal (20°C) conditions and under realistic temperature conditions (same as the precambered steel-VHPC beam investigated in LCPC). Actually, a risk of cracking at very early age due to the transversally restrained shrinkage is probable in this kind of steel-VHPC composite structure (the concrete is cast around the steel girder) and the influence of...

  13. Autogenous standard versus inside-out vein graft to repair facial nerve in rabbits

    Institute of Scientific and Technical Information of China (English)

    TANG Jie; WANG Xue-mei; HU Jing; LUO En; QI Meng-chun

    2008-01-01

    To evaluate autogenous vein grafts and inside-out vein grafts as conduits for the defects repair in the rabbit facial nerves.Methods:The 10 mm segments of buccal division of facial nerve were transected for 48 rabbits in this study.Then the gaps were immediately repaired by autogenous vein grafts or inside-out vein grafts in different groups. All the animals underwent the whisker movement test and electrophysiologic test during the following 16 weeks at different time points postoperatively. Subsequently,the histological examination was performed to observe the facial nerve regeneration morphologically.Results:At 8 weeks after operation,the facial nerve regeneration has significant difference between the experimental group and the control group in electrophysiologic test and histological observation. However,at the end of this study,16 weeks after operation,there was no significant difference between inside-out vein grafts and standard vein grafts in enhancing peripheral nerve regeneration.Conclusion:This study suggest that both kinds of vein grafts play positive roles in facial nerve regeneration after being repaired immediately,but the autogenous inside-out vein grafts might accelerate and facilitate axonal regeneration as compared with control.

  14. Technical innovations in ear reconstruction using a skin expander with autogenous cartilage grafts.

    Science.gov (United States)

    Dashan, Yu; Haiyue, Jiang; Qinghua, Yang; Bo, Pan; Lin, Lin; Tailing, Wang; Yanmei, Wang; Xiao, Qin; Hongxing, Zhuang

    2008-01-01

    Pioneers such as Tanzer and Brent have established the foundations of microtia reconstruction using an autogenous costal cartilage framework. The framework and its skin coverage are the two limiting factors in ear reconstruction. At the present time autogenous rib cartilage and mastoid skin are still first choice materials for most surgeons. They have the combined advantages of well-matched texture and colour. To reconstruct a symmetrical, accurate, prominent auricle and minimise as much as possible the chest wall deformity caused by rib cartilage harvesting, we set out to improve our techniques for cartilaginous framework definition and to use the remnant ear to enhance the projection of the reconstructed ear. Since 2000, 342 cases (366 ears) were treated using our current techniques. Data pertaining to complications were recorded. Final results were assessed a minimum of 1 year postoperatively. The follow-up period ranged from 1 to 6 years. Most of the patients with microtia were satisfied with the results of their ear reconstruction. In conclusion, our techniques help to reduce the quantity of rib cartilage needed to fabricate ear framework and minimise chest wall deformity. The frameworks are accurate, prominent and stable. Reconstructed ears are similar in colour and appearance to the normal side. Our innovations are practical and reliable for microtia reconstruction using skin expanders in combination with a sculpted autogenous rib cartilage framework. PMID:18849209

  15. Dust pollution solutions

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-09-15

    Cimbria Moduflex is a leading manufacturer of dust-free loading chutes and accessories to the bulk handling industry. The Moduflex chute of modular construction can precisely match customer needs. Dust Control Technology recently launched its DustBoss DB-45 which controls airborne particles and surface dust with low water usage. DustScan Ltd., provides a range of equipment for nuisance and PM10 dust monitoring. Donaldson Torit supplies the Torit PowerCore dust collector. 1 photo.

  16. Bone Biopsy

    Science.gov (United States)

    ... Physician Resources Professions Site Index A-Z Bone Biopsy Bone biopsy uses a needle and imaging guidance ... limitations of Bone Biopsy? What is a Bone Biopsy? A bone biopsy is an image-guided procedure ...

  17. Efficacy of guided bone regeneration using composite bone graft and resorbable collagen membrane in Seibert's Class I ridge defects: radiological evaluation.

    Science.gov (United States)

    Saravanan, Pushparajan; Ramakrishnan, T; Ambalavanan, N; Emmadi, Pamela; John, Thomas Libby

    2013-08-01

    The purpose of the study was to evaluate radiologically the efficacy of guided bone regeneration using composite bone graft (autogenous bone graft and anorganic bovine bone graft [Bio-Oss]) along with resorbable collagen membrane (BioMend Extend) in the augmentation of Seibert's class I ridge defects in maxilla. Bone width was evaluated using computerized tomography at day 0 and at day 180 at 2 mm, 4 mm, and 6 mm from the crest. There was a statistically significant increase in bone width between day 0 and day 180 at 2 mm, 4 mm, and 6 mm from the crest. The results of the study demonstrated an increase in bone width of Seibert's class I ridge defects in the maxilla of the study patients. PMID:23964779

  18. A new harvest site for bone graft in anterior cruciate ligament revision surgery.

    Science.gov (United States)

    Franceschi, Francesco; Papalia, Rocco; Di Martino, Alberto; Rizzello, Giacomo; Allaire, Robert; Denaro, Vincenzo

    2007-05-01

    During revision anterior cruciate ligament (ACL) surgery, femoral interference screws frequently require removal. This may lead to significant tunnel widening and possible graft fixation failure as a result. Solutions include drilling the revision tunnel in a different location, using stacked interference screws, or using bone graft to fill the defect. Autogenous iliac crest graft and allograft are both used, but there are significant comorbidities associated with each. We developed a new technique for harvesting autogenous bone graft that avoids many of the complications associated with other graft sources. By use of the existing surgical incision from the initial harvest of the bone-patellar tendon-bone autograft, bone from the medial tibial metaphyseal safe zone is harvested via an OATS tube harvester (Arthrex, Naples, FL). A bone plug 1 mm larger in size than the femoral defect is harvested and arthroscopically inserted via a press-fit technique. At 3 months after bone grafting, patients undergo revision ACL reconstruction. The proximal tibial metaphysis is a safe bone graft harvest site in revision ACL surgery and offers an effective method for filling large bony defects, allowing anatomic reconstruction of the ACL after bone healing has occurred. Furthermore, it eliminates the problems associated with allograft or use of a remote graft donor site. PMID:17478290

  19. Histological Features and Biocompatibility of Bone and Soft Tissue Substitutes in the Atrophic Alveolar Ridge Reconstruction

    Directory of Open Access Journals (Sweden)

    Carlo Maiorana

    2016-01-01

    Full Text Available The reconstruction of the atrophic alveolar ridges for implant placement is today a common procedure in dentistry daily practice. The surgical reconstruction provides for the optimization of the supporting bone for the implants and a restoration of the amount of keratinized gingiva for esthetic and functional reasons. In the past, tissue regeneration has been performed with autogenous bone and free gingival or connective tissue grafts. Nowadays, bone substitutes and specific collagen matrix allow for a complete restoration of the atrophic ridge without invasive harvesting procedures. A maxillary reconstruction of an atrophic ridge by means of tissue substitutes and its histological features are then presented.

  20. Minimal guided bone regeneration procedure for immediate implant placement in the esthetic zone

    Directory of Open Access Journals (Sweden)

    Nettemu Sunil Kumar

    2013-01-01

    Full Text Available The anterior maxilla presents a challenging milieu interior for ideal placement of implants because of the compromised bone quality. With the advent of intraoral bone harvesting and augmentation techniques, immediate implant placement into fresh extraction sockets have become more predictable. Immediate implant placement has numerous advantages compared to the delayed procedure including superior esthetic and functional outcomes, maintenance of soft and hard tissue integrity and increased patient compliance. This case report exhibits immediate implant placement in the maxillary esthetic zone by combining a minimal invasive autogenous block bone graft harvest technique for ensuring successful osseointegration of the implant at the extraction site.

  1. Histological Features and Biocompatibility of Bone and Soft Tissue Substitutes in the Atrophic Alveolar Ridge Reconstruction.

    Science.gov (United States)

    Maiorana, Carlo; Beretta, Mario; Rancitelli, Davide; Grossi, Giovanni Battista; Cicciù, Marco; Herford, Alan Scott

    2016-01-01

    The reconstruction of the atrophic alveolar ridges for implant placement is today a common procedure in dentistry daily practice. The surgical reconstruction provides for the optimization of the supporting bone for the implants and a restoration of the amount of keratinized gingiva for esthetic and functional reasons. In the past, tissue regeneration has been performed with autogenous bone and free gingival or connective tissue grafts. Nowadays, bone substitutes and specific collagen matrix allow for a complete restoration of the atrophic ridge without invasive harvesting procedures. A maxillary reconstruction of an atrophic ridge by means of tissue substitutes and its histological features are then presented. PMID:27022489

  2. Effect of Oxygen Concentration on Autogenous Ignition Temperature and Pneumatic Impact Ignitability of Nonmetallic Materials

    Science.gov (United States)

    Smith, Sarah

    2009-01-01

    Extensive test data exist on the ignitability of nonmetallic materials in pure oxygen, but these characteristics are not as well understood for lesser oxygen concentrations. In this study, autogenous ignition temperature testing and pneumatic impact testing were used to better understand the effects of oxygen concentration on ignition of nonmetallic materials. Tests were performed using oxygen concentrations of 21, 34, 45, and 100 %. The following materials were tested: PTFE Teflon(Registered Trademark), Buna-N, Silicone, Zytel(Registered Trademark) 42, Viton(registered Trademark) A, and Vespel(Registered Trademark) SP-21.

  3. Stepwise surgical approach to diabetic partial foot amputations with autogenous split thickness skin grafting

    Directory of Open Access Journals (Sweden)

    Crystal L. Ramanujam

    2016-06-01

    Full Text Available In the surgical treatment of severe diabetic foot infections, substantial soft tissue loss often accompanies partial foot amputations. These sizeable soft tissue defects require extensive care with the goal of expedited closure to inhibit further infection and to provide resilient surfaces capable of withstanding long-term ambulation. Definitive wound closure management in the diabetic population is dependent on multiple factors and can have a major impact on the risk of future diabetic foot complications. In this article, the authors provide an overview of autogenous skin grafting, including anatomical considerations, clinical conditions, surgical approach, and adjunctive treatments, for diabetic partial foot amputations.

  4. Measurement with corrugated tubes of early-age autogenous shrinkage of cement-based material

    DEFF Research Database (Denmark)

    Tian, Qian; Jensen, Ole Mejlhede

    2009-01-01

    The use of a special corrugated mould enables transformation of volume strain into horizontal, linear strain measurement in the fluid stage. This allows continuous measurement of the autogenous shrinkage of cement-based materials since casting, and also effectively eliminates unwanted influence on...... the measuring results from gravity, temperature variation and mould restraint. In this paper the principle of the corrugated tube measurement is described. A systematic study was carried out on the influence on the measuring results of the material properties, size effects and encapsulated air in the...

  5. The use of implantable bone stimulators in nonunion treatment.

    Science.gov (United States)

    Hughes, Michael S; Anglen, Jeffrey O

    2010-03-01

    Delayed or failure of bone healing in fracture, osteotomy, and arthrodesis patients continues to be a clinical dilemma. Electromagnetic stimulation is 1 modality demonstrated in many studies to aid bone healing; however, relatively few studies depict the use and complications associated with direct current implantable bone stimulators. Over a 9-year period, we studied a consecutive series of 120 adult patients who underwent implantation of a direct current bone stimulator. The goals of this study were to determine the time until healing, the presence of infection, and the need for additional nonunion surgery or salvage procedure following internal bone stimulator placement for nonunion treatment. Of the factors affecting the time until healing, tobacco smoking was a significant factor associated with increased time until healing. Tobacco smoking and duration of nonunion prior to implantable bone stimulator placement were both significant factors in the need for revision nonunion surgery or salvage procedure after implantable bone stimulator placement. Deep soft tissue infection or osteomyelitis was a significant factor predicting prolonged time to healing, subsequent infection following implantable bone stimulator placement, and the need for revision or salvage surgery. With the relative lack of complications directly attributable to electromagnetic implantable bone stimulators, their use may be an effective adjuvant to stable internal fixation and autogenous bone grafting in healing nonunions. However, the use of implantable bone stimulators in patients with nonunion prior to deep soft tissue infection or osteomyelitis exhibited an increased rate of postoperative infection in this study. PMID:20349861

  6. Bone Regeneration in Artificial Jaw Cleft by Use of Carbonated Hydroxyapatite Particles and Mesenchymal Stem Cells Derived from Iliac Bone

    Directory of Open Access Journals (Sweden)

    Motoko Yoshioka

    2012-01-01

    Full Text Available Objectives of the Study. Cleft lip and palate (CLP is a prevalent congenital anomaly in the orofacial region. Autogenous iliac bone grafting has been frequently employed for the closure of bone defects at the jaw cleft site. Since the related surgical procedures are quite invasive for patients, it is of great importance to develop a new less invasive technique. The aim of this study was to examine bone regeneration with mesenchyme stem cells (MSCs for the treatment of bone defect in artificially created jaw cleft in dogs. Materials and Methods. A bone defect was prepared bilaterally in the upper incisor regions of beagle dogs. MSCs derived from iliac bone marrow were cultured and transplanted with carbonated hydroxyapatite (CAP particles into the bone defect area. The bone regeneration was evaluated by standardized occlusal X-ray examination and histological observation. Results. Six months after the transplantation, perfect closure of the jaw cleft was achieved on the experimental side. The X-ray and histological examination revealed that the regenerated bone on the experimental side was almost equivalent to the original bone adjoining the jaw cleft. Conclusion. It was suggested that the application of MSCs with CAP particles can become a new treatment modality for bone regeneration for CLP patients.

  7. Bone Grafts

    Science.gov (United States)

    ... repair and rebuild diseased bones in your hips, knees, spine, and sometimes other bones and joints. Grafts can also repair bone loss caused by some types of fractures or cancers. Once your body accepts the bone ...

  8. Treatment of an Immature Autogenous Arteriovenous Fistula with Percutaneous Transluminal Angioplasty

    International Nuclear Information System (INIS)

    The purpose of this study was to evaluate the efficacy of percutaneous transluminal angioplasty (PTA) in facilitating maturation of autogenous arteriovenous fistulae. There were 12 immature autogenous arteriovenous fistulae. We performed 15 PTAs transvenously. Post-intervention anatomic and clinical successes were estimated, and the 6-month and 1-year primary and secondary patency rates were calculated using Kaplan-Meier analysis. All immature fistulae had underlying stenosis (n=20): arteriovenous anastomosis (n=1) and venous outflow (n=19): 1) within 5 cm from the anastomosis (n=10); 2) more than 5 cm but less than 10 cm from the anastomosis (n=5); 3) more than 10 cm from the anastomosis, including central veins (n=4). Six fistulae had two or more stenoses. Repeat intervention was necessary in two patients. The anatomical success rate was 94.3%, and the clinical success rate was 86.7%. The 6-month and 1-year primary patency rates were 72.7% and 54.5%, and the secondary patency rates were 100% and 81.8%, respectively. All immature hemodialysis fistulae have underlying stenosis, most of which are located near the arteriovenous anastomosis. Early interventional procedures are helpful in the salvage and maintenance of immature arteriovenous fistulae, with a high degree of success

  9. Treatment of an Immature Autogenous Arteriovenous Fistula with Percutaneous Transluminal Angioplasty

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyoung Rae [Kangwon National University, Chuncheon (Korea, Republic of)

    2008-11-15

    The purpose of this study was to evaluate the efficacy of percutaneous transluminal angioplasty (PTA) in facilitating maturation of autogenous arteriovenous fistulae. There were 12 immature autogenous arteriovenous fistulae. We performed 15 PTAs transvenously. Post-intervention anatomic and clinical successes were estimated, and the 6-month and 1-year primary and secondary patency rates were calculated using Kaplan-Meier analysis. All immature fistulae had underlying stenosis (n=20): arteriovenous anastomosis (n=1) and venous outflow (n=19): 1) within 5 cm from the anastomosis (n=10); 2) more than 5 cm but less than 10 cm from the anastomosis (n=5); 3) more than 10 cm from the anastomosis, including central veins (n=4). Six fistulae had two or more stenoses. Repeat intervention was necessary in two patients. The anatomical success rate was 94.3%, and the clinical success rate was 86.7%. The 6-month and 1-year primary patency rates were 72.7% and 54.5%, and the secondary patency rates were 100% and 81.8%, respectively. All immature hemodialysis fistulae have underlying stenosis, most of which are located near the arteriovenous anastomosis. Early interventional procedures are helpful in the salvage and maintenance of immature arteriovenous fistulae, with a high degree of success

  10. Autogenous tibial strut grafts used in severe kyphoscoliosis:surgical policies and preliminary results

    Institute of Scientific and Technical Information of China (English)

    CHEN Hui; QIU Yong; WANG Bin; YU Yang; ZHU Ze-zhang ZHU Li-hua

    2005-01-01

    Background Surgery for severe kyphoscoliosis is frequently unsatisfying because of loss of correction, high rate of pseudarthrosis and neurological complications.Several authors reported that the anterior fusion with strut grafts might improve the surgical outcome.This article describes and assesses the surgical strategies and the application of autogenous tibial strut in the treatment of severe kyphoscoliosis.Results The mean preoperative and postoperative kyphosis was 82°and 52°respectively, and the mean scoliosis was 84°and 44°respectively.Complications included pseudarthrosis (2 cases, one with graft fracture and the other with hook displacement), posterior elements fractures (4), pleura penetrations (3, in the plastic surgery of the thoracic cage), dura tear (2), exudative pleuritis (2, in the anterior surgery), and tibia fracture of the harvesting site (1).The mean loss of correction in coronal and sagittal plane was 6° and 7° respectively.Except for 1 case, the patients with incomplete paraplegia showed improvements to varying extents.Conclusion Autogenous tibial strut can provide excellent support to the kyphoscoliotic spine: it reduces pseudarthrodic rate, loss of correction and complications of graft harvest, it also prevents the occurrence of neurological impairment.

  11. Assessment of autogenous Type 410S stainless steel welds in replacement steam generator tube support structures

    International Nuclear Information System (INIS)

    To eliminate fretting wear caused by flow-induced vibration in recirculating steam generators, tubes are separated from each other by tube support lattice bars. In the U-bend portion of the tube bundle, rows of tubes are separated by fan bars that radiate from collector bars located in the straight-leg portion of the steam generator. The replacement steam generators constructed by Babcock ampersand Wilcox International use Type 410S stainless steel with a specified maximum hardness of Rb 95 for tube support lattice bars, collector bars, and fan bars. An autogenous weld is used to join the fan bar to the collector bar. Corrosion tests were conducted to assess the stress corrosion cracking (SCC) susceptibility of welded type 410S stainless steel. These tests included constant-extension-rate (CERT) tests and long-term immersion tests on 410S in various welded and heat-treated conditions. The results of this test program demonstrate that, when highly stressed, the as-welded 410S weld joints are susceptible to SCC in steam generator environments. However, highly stressed 410S autogenous welds given a post-weld heat treatment were not susceptible to SCC even under faulted steam generator operating conditions

  12. Mesocosmic study on autogenous shrinkage of concrete with consideration of effects of temperature and humidity

    Directory of Open Access Journals (Sweden)

    Yan HAI

    2009-12-01

    Full Text Available A study on the autogenous shrinkage (AS of concrete from a mesocosmic perspective was carried out using numerical simulation technology. The temperature history and the autogenous relative humidity (ARH, two factors that have been shown to have occasional influence on this process in previous studies, were introduced into this study. According to these concepts, a program for simulation of the temperature field, humidity field, and stress field based on the equivalent age method and a fully automatic aggregate modeling tool were used. With the help of these programs, the study of a small concrete specimen provided some useful conclusions: the aggregate and the matrix show distinct distribution properties in the temperature field, humidity field, and stress field; the aggregate-matrix interface has a high possibility of becoming the location of the initial cracking caused by AS of concrete; the distribution of random aggregates is extremely important for mesoscopical analysis; and the temperature history is the main factor affecting the AS of concrete. On the whole, inherent mechanisms and cracking mechanisms of AS of concrete can be explained more reasonably and realistically only by considering the different characteristics of material phases and the effects of temperature and humidity.

  13. Toxicity of lunar dust

    OpenAIRE

    Linnarsson, Dag; Carpenter, James; Fubini, Bice; Gerde, Per; Karlsson, Lars L.; Loftus, David J.; Prisk, G. Kim; Staufer, Urs; Tranfield, Erin M.; van Westrenen, Wim

    2012-01-01

    The formation, composition and physical properties of lunar dust are incompletely characterised with regard to human health. While the physical and chemical determinants of dust toxicity for materials such as asbestos, quartz, volcanic ashes and urban particulate matter have been the focus of substantial research efforts, lunar dust properties, and therefore lunar dust toxicity may differ substantially. In this contribution, past and ongoing work on dust toxicity is reviewed, and major knowle...

  14. Dust particle dynamics in atmospheric dust devils

    Science.gov (United States)

    Izvekova, Yulia; Popel, Sergey

    2016-04-01

    Dust particle dynamics is modeled in the Dust Devils (DDs). DD is a strong, well-formed, and relatively long-lived whirlwind, ranging from small (half a meter wide and a few meters tall) to large (more than 100 meters wide and more than 1000 meters tall) in Earth's atmosphere. We develop methods for the description of dust particle charging in DDs, discuss the ionization processes in DDs, and model charged dust particle motion. Our conclusions are consistent with the fact that DD can lift a big amount of dust from the surface of a planet into its atmosphere. On the basis of the model we perform calculations and show that DDs are important mechanism for dust uplift in the atmospheres of Earth and Mars. Influence of DD electric field on dynamics of dust particles is investigated. It is shown that influence of the electric field on dust particles trajectories is significant near the ground. At some altitude (more then a quarter of the height of DD) influence of the electric field on dust particles trajectories is negligible. For the calculation of the dynamics of dust electric field can be approximated by effective dipole located at a half of the height of DD. This work was supported by the Russian Federation Presidential Program for State Support of Young Scientists (project no. MK-6935.2015.2).

  15. Transplantation of the canine distal ulna as a free vascularized bone graft

    International Nuclear Information System (INIS)

    An autogenous free vascular bone graft of the canine distal ulna was evaluated. The vascularity of the graft was based on a musculoperiosteal sheath supplied solely by the caudal interosseous artery and vein. Four autogenous heterotopic (ulna to tibia) vascular transfers were performed. Two avascular transfers were performed to provide baseline criteria from which the success of vascularized transfers could be assessed. Clinical lameness evaluation, serial radiographs, bone scintigraphy, and sequential fluorochrome bone labeling were performed after surgery in both vascular and avascular transfers. All dogs were free of lameness in the donor limb by the 26th postoperative day. Serial radiographs revealed rapid graft incorporation and hypertrophy in all vascularized grafts and severe bone resorption in nonvascularized grafts. Histology, microangiography, and evaluation of fluorochrome bone labels were performed 90 days after surgery to determine graft viability, incorporation and temporal remodeling patterns. Microangiography and fluorochrome assessment complemented the histological findings. Based on these findings the distal ulnar bone graft was determined to be both viable and structurally adequate for selected cases of long bone reconstruction

  16. Retrograde tracing of fluorescent gold after autogenous nerve transplantation on spinal cord injured in rats

    DEFF Research Database (Denmark)

    Lin, X; Liu, W; Ding, Ming;

    2016-01-01

    Objective To investigate the changes of the fluorescent gold retrograde tracing autogenous nerve transplantation on spinal cord injured in rats. Methods The animals were divided into two groups, with modified Allen impact method to establish model of spinal cord injury. After 4 weeks, the...... transplantation group using autologous sural nerve graft to repair spinal cord injury period and non-transplantation group was only exposed incision without treatment. In the 4, 6 and 8 weeks after operation, the retrograde tracing of FG Fluoro-Gold was performed to discover the recovery of the axial plasma.......01). Conclusion After spinal cord injury, autologous nerve graft was repaired and survived well and promote the recovery of spinal cord injury segment shaft pulp transportation function....

  17. Effect of Autogenous Arc Welding Processes on Tensile and Impact Properties of Ferritic Stainless Steel Joints

    Institute of Scientific and Technical Information of China (English)

    A K Lakshminarayanan; K Shanmugam; V Balasubramanian

    2009-01-01

    The effect of autogeneous arc welding processes on tensile and impact properties of ferritic stainless steel conformed to AISI 409M grade is studied.Rolled plates of 4 mm thickness have been used as the base material for preparing single pass butt welded jointa.Tensile and impact properties,microhardness,microstructure,and fracture surface morphology of continuous current gas tungsten arc welding (CCGTAW),pulsed current gas tungsten arc welding (PCGTAW),and plasma arc welding (PAW) joints are evaluated and the results are compared.It is found that the PAW joints of ferritic stainless steel show superior tensile and impact properties when compared with CCGTAW and PCGTAW joints,and this is mainly due to lower heat input,finer fusion zone grain diameter,and higher fusion zone hardness.

  18. Autogenous vaccination for control of yersiniosis (Yersiniosis salmonis in the salmonid aquaculture in Republic of Macedonia

    Directory of Open Access Journals (Sweden)

    Cvetkovik Aleksandar

    2009-05-01

    Full Text Available The aim of this study was to produce an autogenous vaccine from Yersinia ruckeri isolate and to test it’s efficacy in field conditions. Colonies of Yersinia ruckeri biotype I isolated from rainbow trout with haemorrhagic septicemia were cultivated in TSB and inactivated with formalin. The vaccine was diluted and administered by immersion of rainbow trout fry (~ 4.5 g BW in the vacinal suspension. The experimental infection was done 28 days post vaccination by immersing the fry in infectious suspension of the same isolate. Mortality of the control and vaccinated fish was 87% and 11%, respectively. Vaccinated fish showed high level of gained specific resistance to the infection (RPS 87,4%.

  19. Costs and outcomes of endovascular treatment of thrombosed dialysis autogenous fistulae.

    Science.gov (United States)

    Coentrao, Luis

    2013-01-01

    Functional vascular access is a prerequisite for adequate haemodialysis treatment in patients with end-stage renal disease. Autogenous arteriovenous fistulae are considered superior to synthetic grafts and central venous catheters; however, fistulae are not without problems. Fistulae thrombosis has become a clinical challenge in nephrology practice, with relevant clinical implications for dialysis patients. Several studies have reported on the feasibility and relatively high-clinical success rate of the endovascular approach to thrombosed fistulae in recent years. However, as repeated interventions are usually required to achieve long-term access survival, maintenance of a previously thrombosed fistulae could be a highly expensive policy. The goals of this article are to provide the reader an insight into the multiple endovascular approaches for thrombosed arteriovenous fistulae, bearing in mind its clinical effectiveness and financial implications. PMID:23897178

  20. On Dust Charging Equation

    OpenAIRE

    Tsintsadze, Nodar L.; Tsintsadze, Levan N.

    2008-01-01

    A general derivation of the charging equation of a dust grain is presented, and indicated where and when it can be used. A problem of linear fluctuations of charges on the surface of the dust grain is discussed.

  1. Using inverted autogenous veins to substitute arteries in a canine model

    Directory of Open Access Journals (Sweden)

    Nikeghbalian Saman

    2010-01-01

    Full Text Available Aims : Rapid harvesting of autogenous graft over a wire is an optional way in trauma surgery and it places the inverted conduit so that its adventitial layer is within the lumen of the graft. Our aim of this study was to compare the patency of inverted autogenous graft vs noninverted graft in dogs. Settings and Design : Experimental animal models. Materials and Methods : In this experimental study, 12 dogs were anesthetized and 10 cm of the external jugular vein was excised. The vein was equally divided into two 5-cm sections. One section was inverted and the other was left intact. Afterward, 5 cm of both the femoral arteries were removed and the right (inverted and the left (not inverted arteries were grafted, respectively. The patency of the arteries was evaluated by Color Doppler ultrasonography immediately postoperation and up to 6 months thereafter. Statistical Analysis : Data were analyzed with Fisher′s exact test using SPSS version 15. P value below 0.05 was significant. Results: None of the 12 inverted vein grafts were patent at 3 rd to 14 th days follow-up with Doppler ultrasonography. All of them were completely obstructed by thrombosis. However, 11 (92% of the noninverted vein grafts were patent both at 3 and 6 months follow-up. One of the noninverted grafts was almost completely obstructed with thrombosis (90% and the other 2 were incompletely obstructed with intimal thickening. Conclusions : Despite many favorable results in the previous studies with regard to excellent patency of inverted vein graft, our results were disappointing and we recommend using the graft in the right direction and taking care to preserve the intima intact.

  2. Frontal bone remodeling for gender reassignment of the male forehead: a gender-reassignment surgery.

    Science.gov (United States)

    Hoenig, Johannes Franz

    2011-12-01

    Gender-reassignment therapy, especially for reshaping of the forehead, can be an effective treatment to improve self-esteem. Contouring of the cranial vault, especially of the forehead, still is a rarely performed surgical procedure for gender reassignment. In addition to surgical bone remodeling, several materials have been used for remodeling and refinement of the frontal bone. But due to shortcomings of autogenous bone material and the disadvantages of polyethylene or methylmethacrylate, hydroxyapatite cement (HAC) composed of tetracalcium phosphate and dicalcium phosphate seems to be an alternative. This study aimed to analyze the clinical outcome after frontal bone remodeling with HAC for gender male-to-female reassignment. The 21 patients in the study were treated for gender reassignment of the male frontal bone using HAC. The average age of these patients was 33.4 years (range, 21-42 years). The average volume of HAC used per patient was 3.83 g. The authors' clinical series demonstrated a satisfactory result. The surgery was easy to perform, and HAC was easy to apply and shape to suit individual needs. Overall satisfaction was very high. Therefore, HAC is a welcome alternative to the traditional use of autogenous bone graft for correction of cranial vault irregularities. PMID:21573830

  3. Dust-off

    OpenAIRE

    Maycroft, Neil; Cheang, Shu Lea

    2015-01-01

    The fan of a motherboard switches on and off intermittently. It blows household dust, removed from the inside of a computer carcass, into the air. The dust then settles onto the motherboard, to be blown off again. This continual movement of dust is contained in the piece. However, it should remind us that the ceaseless creation and motion of unconfined dust accompanies all stages of the e-waste journey.

  4. Physics of interstellar dust

    CERN Document Server

    Krugel, Endrik

    2002-01-01

    The dielectric permeability; How to evaluate grain cross sections; Very small and very big particles; Case studies of Mie calculus; Particle statistics; The radiative transition probability; Structure and composition of dust; Dust radiation; Dust and its environment; Polarization; Grain alignment; PAHs and spectral features of dust; Radiative transport; Diffuse matter in the Milky Way; Stars and their formation; Emission from young stars. Appendices Mathematical formulae; List of symbols.

  5. Dusts and Molds

    Science.gov (United States)

    ... ABOUT DUSTS AND MOLDS? Tiny dust particles and mold spores can be inhaled into the lungs. Dusts that come from a living source (“organic dusts”) such as hair, bedding, hay, grain, silage, and dried urine and feces are most dangerous. ...

  6. Bone Cancer

    Science.gov (United States)

    Cancer that starts in a bone is uncommon. Cancer that has spread to the bone from another ... more common. There are three types of bone cancer: Osteosarcoma - occurs most often between ages 10 and ...

  7. Bone Cancer

    Science.gov (United States)

    Cancer that starts in a bone is uncommon. Cancer that has spread to the bone from another part of the body is more common. There are three types of bone cancer: Osteosarcoma - occurs most often between ages 10 ...

  8. Bone Diseases

    Science.gov (United States)

    Your bones help you move, give you shape and support your body. They are living tissues that rebuild constantly ... childhood and your teens, your body adds new bone faster than it removes old bone. After about ...

  9. Unicameral bone cyst of the lunate in an adult: case report

    Directory of Open Access Journals (Sweden)

    Alici Tugrul

    2010-10-01

    Full Text Available Abstract We report a case of a symptomatic unicameral (simple bone cyst of the lunate in a 42-year- old woman. The lesion was treated with curettage and cancellous autogenous iliac bone grafting. At five years of follow-up the wrist was pain free, there were no limitations of motion, and the radiographs showed complete obliteration of the cavity. To the best of our knowledge, no other unicameral bone cyst of the lunate has been reported in an adult. Cysts with significant cavities at the carpal bones in an adult should be approached cautiously, as they may require early curettage and bone grafting for healing, before collapse and degenerative changes occur.

  10. CLINICAL STUDY OF TRANSVERSAL AUGMENTATION IN BONE DEFECTS OF THE MAXILLARY AESTETHIC AREA

    Directory of Open Access Journals (Sweden)

    Vasile NICOLAE

    2015-12-01

    Full Text Available Scope: To outline the importance of autogenic bone graft addition for correcting bone defects in the frontal and lateral maxillary area, and for achieving outstanding esthetic results in cases of large bone defects. Materials and method: A total number of 478 argumentations has been performed in the implantology and dental clinic of the Emergency Military Hospital Sibiu between 2009 and 2013. Results and discussion: The transversal rehabilitation techniques of frontal maxillary ridges, representing 57.2% of all addressed cases, were the most frequent ones, justifying the fact that the frontal maxillary area, aesthetically sensitive, is of special attention for both patients and specialists. Conclusions: In relation with the magnitude of alveolar bone transversal resorption and soft tissue anatomy, surgical procedures are required for bone addition, for obtaining acceptable aesthetic and functional results. To this end, evaluation of defects and systematization of the suitable addition techniques have been carried out.

  11. Toxicity of lunar dust

    CERN Document Server

    Linnarsson, Dag; Fubini, Bice; Gerde, Per; Karlsson, Lars L; Loftus, David J; Prisk, G Kim; Staufer, Urs; Tranfield, Erin M; van Westrenen, Wim

    2012-01-01

    The formation, composition and physical properties of lunar dust are incompletely characterised with regard to human health. While the physical and chemical determinants of dust toxicity for materials such as asbestos, quartz, volcanic ashes and urban particulate matter have been the focus of substantial research efforts, lunar dust properties, and therefore lunar dust toxicity may differ substantially. In this contribution, past and ongoing work on dust toxicity is reviewed, and major knowledge gaps that prevent an accurate assessment of lunar dust toxicity are identified. Finally, a range of studies using ground-based, low-gravity, and in situ measurements is recommended to address the identified knowledge gaps. Because none of the curated lunar samples exist in a pristine state that preserves the surface reactive chemical aspects thought to be present on the lunar surface, studies using this material carry with them considerable uncertainty in terms of fidelity. As a consequence, in situ data on lunar dust...

  12. Repair of the inferior vena cava with autogenous peritoneo-fascial patch graft following abdominal trauma: a case report.

    Science.gov (United States)

    Emmiler, Mustafa; Kocogullari, Cevdet Ugur; Yilmaz, Sezgin; Cekirdekci, Ahmet

    2008-01-01

    Abdominal vascular injuries are among the most challenging and lethal injuries in traumatized patients. Inferior vena cava is the most frequently injured vein during the blunt or penetrating trauma. The primary repair, end to end anastomosis, endovascular stenting, or graft interposition with autogenous or synthetic materials should be considered in selected cases. However, in cases the synthetic graft was preferred, intestinal contaminations due to small or large bowel perforation accompanying the trauma have been cited as a limiting factor for the use of such grafts as in the current case. However, a previous history of lower leg variceal surgery prevents the use of great saphenous vein as a graft. So in the present case, the authors report a patient with inferior vena cava injury repaired with autogenous peritoneo-fascial graft. The authors have used APF graft in traumatic inferior vena cava injury for the first time. PMID:18667465

  13. Effect of nicotine on bone healing in rats - A histological study

    Directory of Open Access Journals (Sweden)

    Dilip Kumar Rayapati

    2014-04-01

    Full Text Available Background & Objectives: Nicotine is the major alkaloid in tobacco products (Nicotiona tabacum and a psychoactive ingredient responsible for the Central Nervous System (CNS effects and tobacco addiction. It’s been reported to have effects directly on the small blood vessels in producing vasoconstriction and increased vascular resistance that exerts on the microvasculature inhibiting the angioblastic response during re-vascularization and limits the recruitment of cytokines, Bone Morphogenic Proteins (BMPs, Transforming Growth Factor – β (TGF – β, Platelet Derived Growth Factor (PDGF and the basic Fibroblast Growth Factor (FGF. This leads to inhibition of re-epithelialization, osteogenesis and cellular healing. This study intends to demonstrate histologically the effect of nicotine on bone healing and the healing of bone defects incorporated with autogenous bone graft in an animal model. Methods: 60 female Wistar rats were used in the study. Nicotine hemisulfate at a dose of 3mg/kg body weight of the animal given twice daily for 4 weeks prior to creation of a bone defect. The defect on the ramus of the mandible and the healing in the defect was evaluated at weekly intervals for four weeks for both the quality and quantity of new bone formation by histological and histomorphometric analysis. Results: Significant impairment of healing of bone both in the early and late stages due to the influence of Nicotine was seen. Conclusion: In our study, incorporation of autogenous bone did significantly improve the bone healing process in the end stages of healing while nicotine significantly impaired the healing of bone in early stages.

  14. REDUCTION OF MOBILITY OF PERIODONTALY AFFECTED TEETH AFTER GINGIVAL AUGMENTATION WITH AN AUTOGENOUS GINGIVAL GRAFT (Case Report.

    Directory of Open Access Journals (Sweden)

    Kamen Kotsilkov

    2015-02-01

    Full Text Available INTRODUCTION: The most severe complication of advanced periodontal lesions is the loss of teeth due to terminal attachment loss and high grade mobility. The goals of the treatment are the improving the plaque control stabilizing of the mobile teeth and arresting of the progression of gingival recession achieving gingival augmentation with adequate vestibulum depth. The autogenous graft is considered to be the most efficient approach where a significant increase of the attached gingiva is needed. OBJECTIVE: This presentation demonstrates the capacity of the autogenous gingival graft approach to reduce the high grade tooth mobility and to augment keratinized gingiva. METHODS: V.T. (46 with moderate generalized periodontitis. The examination reveals thin periodontal biotype, Class IV recessions on 31,41 with III grade mobility and terminal attachment loss, narrow vestibulum and lack of attached gingiva. An autogenous graft technique was selected to achieve simultaneous gingival augmentation and correction of vestibulum depth. RESULTS: A significant and stable increase of the attached gingiva is observed which led to better access for oral hygiene thus creating better conditions for successful long-term outcome. The root coverage was more that 40% and the tooth mobility was decreased to grade I. CONCLUSION: In the limitations of the presented case the free autogenous graft technique seems an appropriate approach in cases with deep Class IV recessions and high grade toot mobility in mandibular frontal area creating proper conditions for effective oral hygiene and decreasing tooth mobility by creating a sufficient amount of attached gingiva needed for the long term maintenance.

  15. Comparative studies on the biology and filarial susceptibility of selected blood-feeding and autogenous Aedes togoi sub-colonies

    Directory of Open Access Journals (Sweden)

    Anuluck Junkum

    2003-06-01

    Full Text Available Blood-feeding and autogenous sub-colonies were selected from a laboratory, stock colony of Aedes togoi, which was originally collected from Koh Nom Sao, Chanthaburi province, Southeast Thailand. Comparative biology and filarial susceptibility between the two sub-colonies (blood-feeding: F11, F13; autogeny: F38, F40 were investigated to evaluate their viability and vectorial capacity. The results of comparison on biology revealed intraspecific differences, i.e., the average egg deposition/gravid female (F11/F38; F13/F40, embryonation rate (F13/F40, hatchability rate (F11/F38; F13/F40, egg width (F11/F38, wing length of females (F13/F40, and wing length and width of males (F11/F38 in the blood-feeding sub-colony were significantly greater than that in the autogenous sub-colony; and egg length (F11/F38 and width (F13/F40, and mean longevity of adult females (F11/F38 and males (F13/F40 in the blood-feeding sub-colony were significantly less than that in the autogenous sub-colony. The results of comparison on filarial susceptibility demonstrated that both sub-colonies yielded similar susceptibilities to Brugia malayi [blood-feeding/autogeny = 56.7% (F11/53.3%(F38, 60%(F13/83.3%(F40] and Dirofilaria immitis [blood-feeding/autogeny = 85.7%(F11/75%(F38, 45%(F13/29.4%(F40], suggesting autogenous Ae. togoi sub-colony was an efficient laboratory vector in study of filariasis.

  16. Comparative studies on the biology and filarial susceptibility of selected blood-feeding and autogenous Aedes togoi sub-colonies

    OpenAIRE

    Anuluck Junkum; Wej Choochote; Atchariya Jitpakdi; Somjai Leemingsawat; Narumon Komalamisra; Narissara Jariyapan; Chavalit Boonyatakorn

    2003-01-01

    Blood-feeding and autogenous sub-colonies were selected from a laboratory, stock colony of Aedes togoi, which was originally collected from Koh Nom Sao, Chanthaburi province, Southeast Thailand. Comparative biology and filarial susceptibility between the two sub-colonies (blood-feeding: F11, F13; autogeny: F38, F40) were investigated to evaluate their viability and vectorial capacity. The results of comparison on biology revealed intraspecific differences, i.e., the average egg deposition/gra...

  17. Effect of Biofeedback-assisted Autogenic Training on Headache Activity and Mood States in Korean Female Migraine Patients

    OpenAIRE

    Kang, Eun-Ho; Park, Joo-Eon; Chung, Chin-Sang; Yu, Bum-Hee

    2009-01-01

    Biofeedback with or without combined autogenic training is known to be effective for the treatment of migraine. This study aimed to examine the effect of biofeedback treatment on headache activity, anxiety, and depression in Korean female patients with migraine headache. Patients were randomized into the treatment group (n=17) and monitoring group (n=15). Mood states including anxiety and depression, and psychophysiological variables such as mean skin temperature of the patients were compared...

  18. Autogene Regenerationserscheinungen in erzgebirgischen Moorwäldern und deren Bedeutung für Schutz und Entwicklung der Moore

    OpenAIRE

    Wendel, Dirk

    2011-01-01

    - Ziele der Arbeit - Ziel vorliegender Arbeit ist, zu analysieren und zu beurteilen, in welchem Umfang autogene Moorregeneration nach anthropogenen Störungen auftritt, welche Voraussetzungen sie erfordert und welche Prozesse von Bedeutung sind. Forstliche und naturschutzfachliche Relevanz der Erkenntnisse sind zu prüfen. - Versuchsanlage und Methoden - Die Versuchsanlage umfasst verschiedene räumliche Skalenebenen und Zeitabschnitte. Im Untersuchungsraum sächsisches Erzgebirge bef...

  19. Volumetric changes of the graft after maxillary sinus floor augmentation with Bio-Oss and autogenous bone in different ratios

    DEFF Research Database (Denmark)

    Jensen, Thomas; Schou, Søren; Svendsen, Patricia Anne;

    2012-01-01

    composition was selected at random and placed concomitant with implant placement. Computed tomographies of the maxillary sinuses were obtained preoperatively, immediately postoperatively, and at euthanasia after 12 weeks. The volumetric changes of the graft were estimated using the Cavalieri principle and...

  20. Randomized controlled analysis-autogenous bone peg graft improved offset hemiarthroplasty in high risk patients: a novel cost effective technique

    OpenAIRE

    Hashmukh Shantilal Varma; Sachin Upadhyay; Nuthan Jagadeesh

    2016-01-01

    Background: Femoral neck fractures in elderly with comorbidities are a serious and increasing challenge. Surgery remains the mainstay of treatment for early rehabilitation. In present Indian scenario, the two major factors that drive our strategy for treatment are affordability and use of cemented prosthesis in high risk patients. The primary objective is to develop a technique that not only maintains the hip biomechanics after arthroplasty but also cost-effective. Methods: Fifty high ris...

  1. Randomized controlled analysis-autogenous bone peg graft improved offset hemiarthroplasty in high risk patients: a novel cost effective technique

    Directory of Open Access Journals (Sweden)

    Hashmukh Shantilal Varma

    2016-06-01

    Results: In patients with novel technique value of X was 1 mm+/-0.8 SD, whereas value of X in conventional technique the value of X was significantly higher of about 7.2 mm+/-1.6 SD and this was associated with increased femoral off set 47.2+/-2.0 SD and the correlation was found to be statistically significant (p<0.05. Furthermore, in group B where graft was not used subsidence was found in 6 patients (24%. None was revised during the period of follow up. Conclusions: Our preliminary results indicate that the approach proposed is feasible and effective in the management of intracapsular fracture neck femur in high risk patients with unipolar prosthesis. [Int J Res Med Sci 2016; 4(6.000: 1897-1902

  2. Microstructure Characterization and Stress Corrosion Evaluation of Autogenous and Hybrid Friction Stir Welded Al-Cu-Li 2195 Alloy

    Science.gov (United States)

    Li, Zhixian; Arbegast, William J.; Meletis, Efstathios I.

    1997-01-01

    Friction stir welding process is being evaluated for application on the Al-Cu-Li 2195 Super-Light Weight External Tank of the Space Transportation System. In the present investigation Al-Cu-Li 2195 plates were joined by autogenous friction stir welding (FSW) and hybrid FSW (friction stir welding over existing variable polarity plasma arc weld). Optical microscopy and transmission electron microscopy (TEM) were utilized to characterize microstructures of the weldments processed by both welding methods. TEM observations of autogenous FSW coupons in the center section of the dynamically-recrystallized zone showed an equiaxed recrystallized microstructure with an average grain size of approx. 3.8 microns. No T(sub 1), precipitates were present in the above-mentioned zone. Instead, T(sub B) and alpha precipitates were found in this zone with a lower population. Alternate immersion, anodic polarization, constant load, and slow strain tests were carried out to evaluate the general corrosion and stress-corrosion properties of autogenous and hybrid FSW prepared coupons. The experimental results will be discussed.

  3. Ultrasonography-guided Balloon Angioplasty in an Autogenous Arteriovenous Fistula: Preliminary Results

    International Nuclear Information System (INIS)

    Percutaneous trasnluminal angioplasty (PTA) of a malfunctioning arteriovenous fistula (AVF) in hemodialysis patients requires the use of contrast angiography and fluoroscopy guidance. We attempted to perform this procedure under duplex ultrasound guidance to reduce the amount of contrast agent administered and to reduce the radiation dose during the interventional procedures. From September 2006 to February 2007, 45 patients received interventional treatment due to malfunctioning hemodialysis access in our hospital. Among the patients, we selected 10 patients diagnosed with stenosis of an autogenous arteriovenous fistula based on a physical examination. There were six males and four females aged 51-78 years (mean age, 59 years). Seven of these patients had a Brescia-Cinimo type fistula and three patients had a basilic vein transposition. All procedures were performed in the angiography suite. All procedures that required angioplasty were performed under duplex ultrasound guidance and then contrast angiography was performed to confirm the final patency of the vessels. Conventional angioplasty was also performed under fluoroscopy guidance for any lesions that required an additional angioplasty. The volume flow before and after the PTA and procedure time were recorded. Clinical success was defined as the performance of one or more successful hemodialysis sessions after treatment. Eight of ten patients did not require an additional angioplasty by conventional angiography after the duplex- guided angioplasty. One case showed recoiling of stenosis after the duplex-guided PTA and another case was missed at duplex scanning due to the extremely short nature of the recoiling of stenosis. The mean volume flow before and after PTA was 167 ml/min (range, 80-259 ml/min) and 394.2 ml/min (range, 120-586 ml/min), respectively. No complications associated with the duplex-guide procedure occurred. In nine cases, PTA enabled hemodialysis to be conducted more than one time. In one

  4. Ultrasonography-guided Balloon Angioplasty in an Autogenous Arteriovenous Fistula: Preliminary Results

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ji Chang [Daejeon St Mary' s Hospital, Daejeon (Korea, Republic of); Cho, June Sik [Chungnam National University College of Medicine, Daejeon (Korea, Republic of)

    2007-09-15

    Percutaneous trasnluminal angioplasty (PTA) of a malfunctioning arteriovenous fistula (AVF) in hemodialysis patients requires the use of contrast angiography and fluoroscopy guidance. We attempted to perform this procedure under duplex ultrasound guidance to reduce the amount of contrast agent administered and to reduce the radiation dose during the interventional procedures. From September 2006 to February 2007, 45 patients received interventional treatment due to malfunctioning hemodialysis access in our hospital. Among the patients, we selected 10 patients diagnosed with stenosis of an autogenous arteriovenous fistula based on a physical examination. There were six males and four females aged 51-78 years (mean age, 59 years). Seven of these patients had a Brescia-Cinimo type fistula and three patients had a basilic vein transposition. All procedures were performed in the angiography suite. All procedures that required angioplasty were performed under duplex ultrasound guidance and then contrast angiography was performed to confirm the final patency of the vessels. Conventional angioplasty was also performed under fluoroscopy guidance for any lesions that required an additional angioplasty. The volume flow before and after the PTA and procedure time were recorded. Clinical success was defined as the performance of one or more successful hemodialysis sessions after treatment. Eight of ten patients did not require an additional angioplasty by conventional angiography after the duplex- guided angioplasty. One case showed recoiling of stenosis after the duplex-guided PTA and another case was missed at duplex scanning due to the extremely short nature of the recoiling of stenosis. The mean volume flow before and after PTA was 167 ml/min (range, 80-259 ml/min) and 394.2 ml/min (range, 120-586 ml/min), respectively. No complications associated with the duplex-guide procedure occurred. In nine cases, PTA enabled hemodialysis to be conducted more than one time. In one

  5. DUST FORMATION IN MACRONOVAE

    International Nuclear Information System (INIS)

    We examine dust formation in macronovae (as known as kilonovae), which are the bright ejecta of neutron star binary mergers and one of the leading sites of r-process nucleosynthesis. In light of information about the first macronova candidate associated with GRB 130603B, we find that dust grains of r-process elements have difficulty forming because of the low number density of the r-process atoms, while carbon or elements lighter than iron can condense into dust if they are abundant. Dust grains absorb emission from ejecta with an opacity even greater than that of the r-process elements, and re-emit photons at infrared wavelengths. Such dust emission can potentially account for macronovae without r-process nucleosynthesis as an alternative model. This dust scenario predicts a spectrum with fewer features than the r-process model and day-scale optical-to-ultraviolet emission

  6. Bone Densitometry (Bone Density Scan)

    Science.gov (United States)

    ... of DXA Bone Densitometry? What is a Bone Density Scan (DXA)? Bone density scanning, also called dual-energy x-ray absorptiometry ( ... is today's established standard for measuring bone mineral density (BMD). An x-ray (radiograph) is a noninvasive ...

  7. Operational Dust Prediction

    Science.gov (United States)

    Benedetti, Angela; Baldasano, Jose M.; Basart, Sara; Benincasa, Francesco; Boucher, Olivier; Brooks, Malcolm E.; Chen, Jen-Ping; Colarco, Peter R.; Gong, Sunlin; Huneeus, Nicolas; Jones, Luke; Lu, Sarah; Menut, Laurent; Morcrette, Jean-Jacques; Mulcahy, Jane; Nickovic, Slobodan; Garcia-Pando, Carlos P.; Reid, Jeffrey S.; Sekiyama, Thomas T.; Tanaka, Taichu Y.; Terradellas, Enric; Westphal, Douglas L.; Zhang, Xiao-Ye; Zhou, Chun-Hong

    2014-01-01

    Over the last few years, numerical prediction of dust aerosol concentration has become prominent at several research and operational weather centres due to growing interest from diverse stakeholders, such as solar energy plant managers, health professionals, aviation and military authorities and policymakers. Dust prediction in numerical weather prediction-type models faces a number of challenges owing to the complexity of the system. At the centre of the problem is the vast range of scales required to fully account for all of the physical processes related to dust. Another limiting factor is the paucity of suitable dust observations available for model, evaluation and assimilation. This chapter discusses in detail numerical prediction of dust with examples from systems that are currently providing dust forecasts in near real-time or are part of international efforts to establish daily provision of dust forecasts based on multi-model ensembles. The various models are introduced and described along with an overview on the importance of dust prediction activities and a historical perspective. Assimilation and evaluation aspects in dust prediction are also discussed.

  8. Dust Devil Tracks

    Science.gov (United States)

    2002-01-01

    (Released 8 May 2002) The Science This image, centered near 50.0 S and 17.7 W displays dust devil tracks on the surface. Most of the lighter portions of the image likely have a thin veneer of dust settled on the surface. As a dust devil passes over the surface, it acts as a vacuum and picks up the dust, leaving the darker substrate exposed. In this image there is a general trend of many of the tracks running from east to west or west to east, indicating the general wind direction. There is often no general trend present in dust devil tracks seen in other images. The track patterns are quite ephemeral and can completely change or even disappear over the course of a few months. Dust devils are one of the mechanisms that Mars uses to constantly pump dust into the ubiquitously dusty atmosphere. This atmospheric dust is one of the main driving forces of the present Martian climate. The Story Vrrrrooooooooom. Think of a tornado, the cartoon Tasmanian devil, or any number of vacuum commercials that powerfully suck up swirls of dust and dirt. That's pretty much what it's like on the surface of Mars a lot of the time. Whirlpools of wind called

  9. A Novel Albumin-Based Tissue Scaffold for Autogenic Tissue Engineering Applications

    Science.gov (United States)

    Li, Pei-Shan; -Liang Lee, I.; Yu, Wei-Lin; Sun, Jui-Sheng; Jane, Wann-Neng; Shen, Hsin-Hsin

    2014-07-01

    Tissue scaffolds provide a framework for living tissue regeneration. However, traditional tissue scaffolds are exogenous, composed of metals, ceramics, polymers, and animal tissues, and have a defined biocompatibility and application. This study presents a new method for obtaining a tissue scaffold from blood albumin, the major protein in mammalian blood. Human, bovine, and porcine albumin was polymerised into albumin polymers by microbial transglutaminase and was then cast by freeze-drying-based moulding to form albumin tissue scaffolds. Scanning electron microscopy and material testing analyses revealed that the albumin tissue scaffold possesses an extremely porous structure, moderate mechanical strength, and resilience. Using a culture of human mesenchymal stem cells (MSCs) as a model, we showed that MSCs can be seeded and grown in the albumin tissue scaffold. Furthermore, the albumin tissue scaffold can support the long-term osteogenic differentiation of MSCs. These results show that the albumin tissue scaffold exhibits favourable material properties and good compatibility with cells. We propose that this novel tissue scaffold can satisfy essential needs in tissue engineering as a general-purpose substrate. The use of this scaffold could lead to the development of new methods of artificial fabrication of autogenic tissue substitutes.

  10. Cephalic Arch Stenosis in Autogenous Haemodialysis Fistulas: Treatment With the Viabahn Stent-Graft

    International Nuclear Information System (INIS)

    Cephalic arch stenosis (CAS) is an important and common cause of dysfunction in autogenous haemodialysis fistulas that requires multiple reinterventions and aggressive surveillance. We evaluated the safety and efficacy of the Viabahn stent-graft for the management of CAS. Between April 2005 and October 2011, 11 consecutive patients [four men and seven women (mean age 56.7 years)] with CAS and dysfunctional fistulas were treated with insertion of 11 Viabahn stent-grafts. Six stent-grafts were inserted due to residual stenosis after angioplasty and five for fistuloplasty-induced rupture. No patient was lost to follow-up. The technical and clinical success rate was 100 %. Primary access patency rates were 81.8 % [95 % confidence interval (CI) 0.482–0.977] at 6 months and 72.7 % (95 % CI 0.390–0.939) at 12 months. Secondary access patency rates were 90.9 % at 6 months (95 % CI 0.587–0.997). There were no procedure-related complications. Mean follow-up was 543.8 days (range 156–2,282). The use of the Viabahn stent-graft in the management of CAS is technically feasible and, in this small series, showed patency rates that compare favorably with historical data of angioplasty and bare stents.

  11. Autogenic Feedback Training Exercise and pilot performance: enhanced functioning under search-and-rescue flying conditions

    Science.gov (United States)

    Cowings, P. S.; Kellar, M. A.; Folen, R. A.; Toscano, W. B.; Burge, J. D.

    2001-01-01

    Studies have shown that autonomous mode behavior is one cause of aircraft fatalities due to pilot error. In such cases, the pilot is in a high state of psychological and physiological arousal and tends to focus on one problem, while ignoring more critical information. This study examined the effect of training in physiological self-recognition and regulation, as a means of improving crew cockpit performance. Seventeen pilots were assigned to the treatment and control groups matched for accumulated flight hours. The treatment group contained 4 pilots from HC-130 Hercules aircraft and 4 HH-65 Dolphin helicopter pilots; the control group contained 3 pilots of HC-130s and 6 helicopter pilots. During an initial flight, physiological data were recorded on each crewmember and an instructor pilot rated individual crew performance. Eight crewmembers were then taught to regulate their own physiological response levels using Autogenic-Feedback Training Exercise (AFTE). The remaining participants received no training. During a second flight, treatment participants showed significant improvement in performance (rated by the same instructor pilot as in pretests) while controls did not improve. The results indicate that AFTE management of high states of physiological arousal may improve pilot performance during emergency flying conditions.

  12. Response of spinal myoclonus to a combination therapy of autogenic training and biofeedback

    Directory of Open Access Journals (Sweden)

    Kempuraj Duraisamy

    2007-10-01

    Full Text Available Abstract Introduction Clinical evidence indicates that certain types of movement disorders are due to psychosomatic factors. Patients with myoclonic movements are usually treated by a variety of therapeutic agents. Autogenic training (AT, a recognized form of psychosomatic therapies, is suitable for certain types of neurological diseases. We describe a patient with myoclonus who failed to respond to conventional medical therapy. His symptoms were exaggerated by psychogenic factors, especially anger. Case presentation A 42-year-old man was admitted to our hospital, Preventive Welfare Clinic, for severe paroxysmal axial myoclonus of the left shoulder and abdominal muscles. The initial diagnosis was "combination of spinal segmental myoclonus and propriospinal myoclonus". The myoclonic movements did not occur during sleep but were aggravated by bathing, alcohol drinking, and anger. Psychological examination indicated hostile attribution. Although considered not to be a case of psychogenic myoclonus, a "psychogenic factor" was definitely involved in the induction of the organic myoclonus. The final diagnosis was "combination of spinal segmental myoclonus and propriospinal myoclonus accompanied by features of psychosomatic disorders". The patient underwent psychosomatic therapy including AT and surface electromyography (EMG-biofeedback therapy and treatment with clonazepam and carbamazepine. Results AT and EMG-biofeedback resulted in shortening the duration and reducing the amplitude and frequency of the myoclonic discharges. Conclusion Psychosomatic therapy with AT and surface EMG-biofeedback produced excellent improvement of myoclonic movements and allowed the reduction of the dosage of conventional medications.

  13. Effect of ultraviolet-treated autogenous blood on some hematologic indexes in horses

    International Nuclear Information System (INIS)

    Comparative clinical and experimental investigations were carried out on 18 clinically normal horses. It was found that the single transfusion of in vitro UV-treated autogenous blood, following a previously described method, was tolerated well by horses and did not lead to any deviations from the normal indices. Under the effect of the treated blood there was an increase in the hemoglobin content, rise in the erythrocyte and leukocyte count with slightly expressed hyper-leukocytosis and weak neutrophilia (simple regeneration of the blood). The sedimentation of erythrocytes also showed higher rates as early as the first hour following the autohemotransfusion, remaining at the attained level up to the fourth day, while on the sixth day it again came back to the initial value. The contents of calcium and inorganic phosphorus rose, showing a slightly expressed shift to the physiologic level without reaching it. The changes in the phagocytic activity of the blood showed that the autohemotransfusion stimulates phagocytosis. Along with these effects the bacteriostatic titer of the blood, as recorded with the use of the anthrax bacillus as early as the first hour, was likewise favourably affected, the highest titers being observed at the 24th and 48th hour. (author)

  14. Comparison of lyophilization, and freezing in honey as techniques to preserve cortical bone allografts used to repair experimental femoral defects in domestic adult cats

    Directory of Open Access Journals (Sweden)

    M.P. Ferreira

    2012-04-01

    Full Text Available Cats with orthopedic conditions are a prominent part of the clinical work of veterinary. Conditions such as comminuted fractures, bone tumors and non-unions are often difficult to repair and may require the use of bone grafts for treatment. This study evaluated cortical bone allografts preserved in honey, frozen or lyophilized for correcting long bone defects created in the diaphysis of the right femur of domestic cats (n=24. In the control group (n=6, the defect was repaired using autogenous cortical bone graft. In the remaining animals (n=6/group, the defect was repaired with cortical bone allografts preserved in honey, frozen or lyophilized. Success of graft incorporation and length of time for consolidation were assessed through clinical, radiographic and histological evaluations performed up to 180 days. In the control, frozen, honey and lyophylized groups, respectively, success of graft incorporation was 91.6%, 83.3%, 75%, and 25%, with corresponding mean length of time for consolidation of 83.1, 78, 105 and 120 days. Incorporation percentage in the lyophilized group was significantly lower than in the frozen and control groups. In conclusion, bone grafts preserved in honey or frozen were effective for repairing cortical defects in the femurs of cats as compared to autogenous cortical bone grafts.

  15. Low Bone Density

    Science.gov (United States)

    ... Density Exam/Testing › Low Bone Density Low Bone Density Low bone density is when your bone density ... people with normal bone density. Detecting Low Bone Density A bone density test will determine whether you ...

  16. Angiogenic factor-enriched platelet-rich plasma enhances in vivo bone formation around alloplastic graft material

    OpenAIRE

    Kim, Eun-Seok; Kim, Jae-Jin; Park, Eun-Jin

    2010-01-01

    PURPOSE Although most researchers agree that platelet-rich plasma (PRP) is a good source of autogenous growth factors, its effect on bone regeneration is still controversial. The purpose of this study was to evaluate whether increasing angiogenic factors in the human PRP to enhance new bone formation through rapid angiogenesis. MATERIAL AND METHODS In vitro, the human platelets were activated with application of shear stress, 20 µg/ml collagen, 2 mM CaCl2 and 10U thrombin/1 × 109 platelets. L...

  17. Bone tumor

    Science.gov (United States)

    ... physical exam. Tests that may be done include: Alkaline phosphatase blood level Bone biopsy Bone scan Chest x- ... also affect the results of the following tests: Alkaline phosphatase isoenzyme Blood calcium level Parathyroid hormone Blood phosphorus ...

  18. Lunar Dust Mitigation Screens

    Science.gov (United States)

    Knutson, Shawn; Holloway, Nancy

    With plans for the United States to return to the moon, and establish a sustainable human presence on the lunar surface many issues must be successfully overcome. Lunar dust is one of a number of issues with the potential to create a myriad of problems if not adequately addressed. Samples of dust brought back from Apollo missions show it to be soft, yet sharp and abrasive. The dust consists of a variety of morphologies including spherical, angular blocks, shards, and a number of irregular shapes. One of the main issues with lunar dust is its attraction to stick to anything it comes in contact with (i.e. astronauts, equipment, habitats, etc.). Ionized radiation from the sun strikes the moon's surface and creates an electrostatic charge on the dust. Further, the dust harbors van der Waals forces making it especially difficult to separate once it sticks to a surface. During the Apollo missions, it was discovered that trying to brush the lunar dust from spacesuits was not effective, and rubbing it caused degradation of the suit material. Further, when entering the lunar module after moonwalks, the astronauts noted that the dust was so prolific inside the cabin that they inhaled and ingested it, causing at least one of them, Harrison "Jack" Schmidt, to report irritation of the throat and lungs. It is speculated that the dust could also harm an astronaut's nervous and cardiovascular systems, especially during an extended stay. In addition to health issues, the dust can also cause problems by scouring reflective coatings off of thermal blankets, and roughening surfaces of windows and optics. Further, panels on solar cells and photovoltaics can also be compromised due to dust sticking on the surfaces. Lunar dust has the capacity to penetrate seals, interfere with connectors, as well as mechanisms on digging machines, all of which can lead to problems and failure. To address lunar dust issues, development of electrostatic screens to mitigate dust on sur-faces is currently

  19. NASA-Navy Telemedicine: Autogenic Feedback Training Exercises for Motion Sickness

    Science.gov (United States)

    Acromite, Michael T.; Cowings, Patricia; Toscano, William; Davis, Carl; Porter, Henry O.

    2010-01-01

    Airsickness is the most significant medical condition affecting naval aviation training. A 2001 study showed that airsickness was reported in 81% of naval aviation students and was associated with 82% of below average flight scores. The cost to a single training air-wing was over $150,000 annually for fuel and maintenance costs alone. Resistent cases are sent to the Naval Aerospace Medical Institute (NAMI) for evaluation and desensitization in the self-paced airsickness desensitization (SPAD) program. This approach is 75% successful, but can take up to 8 weeks at a significant travel cost. NASA Ames Research Center's Autogenic Feedback Training Exercises (AFTE) uses physiological and biofeedback training for motion sickness prevention. It has a remote capability that has been used from Moffett Field, CA to Atlanta, GA . AFTE is administered in twelve (30-minute) training sessions. The success rate for the NASA AFTE program has been over 85%. Methods: Implementation Phases: Phase I: Transfer NASA AFTE to NAMI; NASA will remotely train aviation students at NAMI. Phase II: NAMI-centered AFTE application with NASA oversight. Phase III: NAMI-centered AFTE to remotely train at various Navy sites. Phase IV: NAMI to offer Tri-service application and examine research opportunities. Results: 1. Use available telemedicine connectivity between NAMI and NASA. 2. Save over $2,000 per student trained. 3. Reduce aviation training attrition. 4. Provide standardization of multi-location motion sickness training. 5. Future tri-service initiatives. 6. Data to NASA and Navy for QA and research opportunities.

  20. Autogenic-feedback training exercise is superior to promethazine for control of motion sickness symptoms

    Science.gov (United States)

    Cowings, P. S.; Toscano, W. B.

    2000-01-01

    Motion sickness symptoms affect approximately 50% of the crew during space travel and are commonly treated with intramuscular injections of promethazine. The purpose of this paper is to compare the effectiveness of three treatments for motion sickness: intramuscular injections (i.m.) of promethazine, a physiological training method (autogenic-feedback training exercise [AFTE]), and a no-treatment control. An earlier study tested the effects of promethazine on cognitive and psychomotor performance and motion sickness tolerance in a rotating chair. For the present paper, motion sickness tolerance, symptom reports, and physiological responses of these subjects were compared to matched subjects selected from an existing database who received either AFTE or no treatment. Three groups of 11 men, between the ages of 33 and 40 years, were matched on the number of rotations tolerated during their initial rotating-chair motion sickness test. The motion sickness test procedures and the 7-day interval between tests were the same for all subjects. The drug group was tested under four treatment conditions: baseline (no injections), a 25 mg dose of promethazine, a 50 mg dose of promethazine, and a placebo of sterile saline. AFTE subjects were given four 30-minute AFTE sessions before their second, third, and fourth motion sickness tests (6 hours total). The no-treatment control subjects were only given the four rotating-chair tests. Motion sickness tolerance was significantly increased after 4 hours of AFTE when compared to either 25 mg (p effect of promethazine was an inhibition of skin conductance level. The AFTE group showed significantly less heart rate and skin conductance variability during motion sickness tests administered after training.

  1. Anatomic study of the lacrimal fossa and lacrimal pathway for bypass surgery with autogenous tissue grafting

    Directory of Open Access Journals (Sweden)

    Hai Tao

    2014-01-01

    Full Text Available Purpose: To study the microsurgical anatomy of the lacrimal drainage system and to provide anatomical evidence for transnasal endoscopic lacrimal drainage system bypass surgery by autogenous tissue grafting. Materials and Methods: A total of 20 Chinese adult cadaveric heads in 10% formaldehyde, comprising 40 lacrimal ducts were used. The middle third section of the specimens were examined for the following features: the thickness of the lacrimal fossa at the anterior lacrimal crest, vertical middle line, and posterior lacrimal crest; the cross section of the upper opening, middle part, and lower opening of the nasolacrimal canal; the horizontal, 30° oblique, and 45° oblique distances from the lacrimal caruncle to the nasal cavity; the distance from the lacrimal caruncle to the upper opening of the nasolacrimal duct; and the included angle between the lacrimal caruncle-nasolacrimal duct upper opening junction and Aeby′s plane. Results: The middle third of the anterior lacrimal crest was significantly thicker than the vertical middle line and the posterior lacrimal crest (P > 0.05. The horizontal distance, 30° oblique distance, and 45° oblique distance from the lacrimal caruncle to the nasal cavity exhibited no significant differences (P > 0.05. The included angle between the lacrimal caruncle and the lateral wall middle point of the superior opening line of the nasolacrimal duct and Aeby′s plane was average (49.9° ± 1.8°. Conclusion: The creation of the bony tunnel should start from the middle or posterior middle part of the lacrimal fossa, extending toward the anterior inferior region with an optimal downward oblique angle of 45°.

  2. Efficacy of Combined Therapy of Periosteum and Bone Allograft in a Critical-Sized Defect Model in New Zealand White Rabbits

    Science.gov (United States)

    Zhang, Dawei; Huang, Dong; Huang, Yongjun; Liu, Yuanhang; Lin, Bochuan; Yu, Chaoqun; Mou, Yong; Wu, Weichi; Zhang, Huiru; Lin, Hao

    2014-01-01

    Background Large segmental bone defects caused by trauma, infection, or bone tumor resection are difficult to cure and have been a problem in the field of bone repair for decades. The objective of this study was to discuss the efficacy of combined therapy of free periosteum and bone allograft in treating bone defects and to provide a theoretical basis for clinical application of this therapy. Material/Methods A unilateral tibia cortical defect model in New Zealand white rabbits was established according to Girolamo method. Total 48 rabbits were randomized into 3 groups: a simple bone defect group (n=16), an autogenous bone graft group (n=16), and a periosteum and bone allograft combined therapy group (n=16). The efficacy was evaluated by imaging inspections and scoring, HE staining, and RT-PCR in postoperative weeks 2, 4, 8, and 12. Results The results of imaging and histopathological inspections in the study indicated that in postoperative weeks 4, 8, and 12 the experimental and control groups had statistically significant differences in Lane-Sandhu radiographic scoring and relative bone density when compared with the simple bone defect group (P<0.05). The RT-PCR results suggested that the expression of SPP-1, BMP-2, and VEGF in the experimental group was higher than in the control group (P<0.05) and the expression of Col Iα1 in the control group was higher than in the experimental group (P<0.05). Conclusions Efficacies of the combined therapy (periosteum combined with bone allografting) and the criterion standard therapy (autogenous bone grafting) are equivalent in treating bone defects in New Zealand white rabbits. PMID:25417209

  3. Dust Storms: Why Are Dust Storms a Concern?

    Science.gov (United States)

    ... in Environmental Health, Chemistry, and Toxicology More Resources Dust Storms en español Why are dust storms a concern? A dust storm is a moving ... on Human Health (US Geological Survey) Chemicals in Dust Storms Are these chemicals in MY community? Particulate Matter ...

  4. Components of inhibition in autogenous- and reactive-type obsessive-compulsive disorder: Dissociation of interference control.

    Science.gov (United States)

    Fan, Jie; Liu, Wanting; Lei, Hui; Cai, Lin; Zhong, Mingtian; Dong, Jiaojiao; Zhou, Cheng; Zhu, Xiongzhao

    2016-05-01

    Obsessive-compulsive disorder (OCD) is characterized by unwanted, intrusive thoughts (obsessions) and/or repetitive, ritualistic behaviors (compulsions). Findings related to the two components of inhibition, namely interference control and behavioral inhibition, among OCD patients have been inconsistent. It might be that this inconsistency is due to the heterogeneity among OCD cases representing multiple subtypes of OCD, such as autogenous obsessions and reactive obsessions types (AOs vs. ROs). AOs and ROs are distinguished by the category of their most disturbing obsessions. The purpose of this study was to systematically examine whether inhibition functions differ between AO and RO patients. We assessed interference control and behavioral inhibition with the emotional Stroop task (EST) and stop-signal task (SST), respectively, in 42 AOs, 55 ROs and 62 healthy controls (HCs) and event-related potentials (ERPs) were recorded in a random subset of these subjects (25 AOs, 25 ROs, and 31HCs). Results showed that in the EST, AOs exhibited longer reaction times (RTs) for color-naming positive-, negative-, and neutral-valence word stimulus than both ROs and HCs, and demonstrated larger P2 and less negative N450 amplitudes than HCs and larger P3 amplitudes than ROs and HCs. In the SST, both AOs and ROs showed lengthened stop signal reaction time (SSRT) and reduced Stop-P3 amplitudes in successful inhibition (SI) trials compared to the HC group. These present findings suggest that behavioral inhibition impairment may reflect a common pathology in both the autogenous- and reactive-type OCD patients, whereas interference inhibition impairment appears to be specific to patients with autogenous obsessions. These findings strengthened the insight into the clinical heterogeneity and pathophysiology of OCD. PMID:26995786

  5. Modified Weaver-Dunn Procedure Versus The Use of Semitendinosus Autogenous Tendon Graft for Acromioclavicular Joint Reconstruction

    Science.gov (United States)

    Hegazy, Galal; Safwat, Hesham; Seddik, Mahmoud; Al-shal, Ehab A.; Al-Sebai, Ibrahim; Negm, Mohame

    2016-01-01

    Background: The optimal operative method for acromioclavicular joint reconstruction remains controversial. The modified Weaver-Dunn method is one of the most popular methods. Anatomic reconstruction of coracoclavicular ligaments with autogenous tendon grafts, widely used in treating chronic acromioclavicular joint instability, reportedly diminishes pain, eliminates sequelae, and improves function as well as strength. Objective: To compare clinical and radiologic outcomes between a modified Weaver-Dunn procedure and an anatomic coracoclavicular ligaments reconstruction technique using autogenous semitendinosus tendon graft. Methods: Twenty patients (mean age, 39 years) with painful, chronic Rockwood type III acromioclavicular joint dislocations were subjected to surgical reconstruction. In ten patients, a modified Weaver-Dunn procedure was performed, in the other ten patients; autogenous semitendinosus tendon graft was used. The mean time between injury and the index procedure was 18 month (range from 9 – 28). Clinical evaluation was performed using the Oxford Shoulder Score and Nottingham Clavicle Score after a mean follow-up time of 27.8 months. Preoperative and postoperative radiographs were compared. Results: In the Weaver-Dunn group the Oxford Shoulder Score improved from 25±4 to 40±2 points. While the Nottingham Clavicle Score increased from 48±7 to 84±11. In semitendinosus tendon graft group, the Oxford Shoulder Score improved from 25±3 points to 50±2 points and the Nottingham Clavicle Score from 48±8 points to 95±8, respectively. Conclusion: Acromioclavicular joint reconstruction using the semitendinosus tendon graft achieved better Oxford Shoulder Score and Nottingham Clavicle Score compared to the modified Weaver-Dunn procedure. PMID:27347245

  6. Self-organization in irregular landscapes: Detecting autogenic interactions from field data using descriptive statistics and dynamical systems theory

    Science.gov (United States)

    Larsen, L.; Watts, D.; Khurana, A.; Anderson, J. L.; Xu, C.; Merritts, D. J.

    2015-12-01

    The classic signal of self-organization in nature is pattern formation. However, the interactions and feedbacks that organize depositional landscapes do not always result in regular or fractal patterns. How might we detect their existence and effects in these "irregular" landscapes? Emergent landscapes such as newly forming deltaic marshes or some restoration sites provide opportunities to study the autogenic processes that organize landscapes and their physical signatures. Here we describe a quest to understand autogenic vs. allogenic controls on landscape evolution in Big Spring Run, PA, a landscape undergoing restoration from bare-soil conditions to a target wet meadow landscape. The contemporary motivation for asking questions about autogenic vs. allogenic controls is to evaluate how important initial conditions or environmental controls may be for the attainment of management objectives. However, these questions can also inform interpretation of the sedimentary record by enabling researchers to separate signals that may have arisen through self-organization processes from those resulting from environmental perturbations. Over three years at Big Spring Run, we mapped the dynamic evolution of floodplain vegetation communities and distributions of abiotic variables and topography. We used principal component analysis and transition probability analysis to detect associative interactions between vegetation and geomorphic variables and convergent cross-mapping on lidar data to detect causal interactions between biomass and topography. Exploratory statistics revealed that plant communities with distinct morphologies exerted control on landscape evolution through stress divergence (i.e., channel initiation) and promoting the accumulation of fine sediment in channels. Together, these communities participated in a negative feedback that maintains low energy and multiple channels. Because of the spatially explicit nature of this feedback, causal interactions could not

  7. Radioactive dust sampling

    International Nuclear Information System (INIS)

    This technical report is the second of a five part series on the technical evaluation of a number of dust monitoring instruments and the characterization of Long-Lived Radioactive Dust (LLRD). The data reported here pertain to an experimental study conducted under laboratory controlled conditions in a Long-Lived Radioactive Dust Test Facility (LLRDTF) designed for this purpose. This study was carried out with a twofold purpose in mind, namely, for the characterization of dust and LLRD, and for the evaluation of a variety of monitoring instruments, including cascade impactors, optical particle counters, nylon cyclones, open face filter samplers, and α-particle personal dosimeters, the latter normally used for α-particle radiation exposure purposes. Several non-radioactive and radioactive dusts were characterized. The non-radioactive dusts were SiC, Al2O3, talcum powder, corn starch and flour, while uranium tailings were used as a radioactive dust. Clear differences in instrument performance were observed for the various measurements made

  8. Osteogenesis effect of guided bone regeneration combined with alveolar cleft grafting: assessment by cone beam computed tomography.

    Science.gov (United States)

    Xiao, W-L; Zhang, D-Z; Chen, X-J; Yuan, C; Xue, L-F

    2016-06-01

    Cone beam computed tomography (CBCT) allows for a significantly lower radiation dose than conventional computed tomography (CT) scans and provides accurate images of the alveolar cleft area. The osteogenic effect of guided bone regeneration (GBR) vs. conventional alveolar bone grafting alone for alveolar cleft defects was evaluated in this study. Sixty alveolar cleft patients were divided randomly into two groups. One group underwent GBR using acellular dermal matrix film combined with alveolar bone grafting using iliac crest bone grafts (GBR group), while the other group underwent alveolar bone grafting only (non-GBR group). CBCT images were obtained at 1 week and at 3 months following the procedure. Using Simplant 11.04 software, the bone resorption rate was calculated and compared between the two groups. The bone resorption rate from 1 week to 3 months following bone grafting without the GBR technique was 36.50±5.04%, whereas the bone resorption rate using the GBR technique was 31.69±5.50% (P=0.017). The application of autogenous iliac bone combined with the GBR technique for alveolar bone grafting of alveolar cleft patients can reduce bone resorption and result in better osteogenesis. PMID:26876144

  9. Autogenic incision and terrace formation resulting from abrupt late-glacial base-level fall, lower Chippewa River, Wisconsin, USA

    Science.gov (United States)

    Faulkner, Douglas J.; Larson, Phillip H.; Jol, Harry M.; Running, Garry L.; Loope, Henry M.; Goble, Ronald J.

    2016-08-01

    A paucity of research exists regarding the millennial-scale response of inland alluvial streams to abrupt base-level fall. Studies of modern systems indicate that, over short time scales, the response is a diffusion-like process of upstream-propagating incision. In contrast, evidence from the lower Chippewa River (LCR), located in the upper Midwest of the USA, suggests that autogenic controls operating over time scales of several millennia can overwhelm diffusion, resulting in incision that is prolonged and episodic. During the Last Glacial Maximum, the LCR drained the Chippewa Lobe of the Laurentide Ice Sheet to the glacial upper Mississippi River (UMR). As a meltwater stream, it aggraded and filled its valley with glacial outwash, as did its largest tributaries, which were also meltwater streams. Its nonglacial tributaries aggraded, too, filling their valleys with locally derived sediment. During deglaciation, the UMR incised at least twice, abruptly lowering the LCR's base level - ~ 15 m at 16 ka or earlier and an additional 40 m at ca. 13.4 ka. Each of these base-level falls initiated incision of the LCR, led by upstream migrating knickpoints. The propagation of incision has, however, been a lengthy process. The optically stimulated luminescence (OSL) ages of terrace alluvium indicate that, by 13.5 ka, incision had advanced up the LCR only 15 km, and by 9 ka, only 55 km. The process has also been episodic, resulting in the formation of fill-cut terraces (inferred from GPR surveys and exposures of terrace alluvium) that are younger and more numerous in the upstream direction. Autogenic increases in sediment load and autogenic bed armoring, the result of periodic tributary-stream rejuvenation and preferential winnowing of fines by the incising river, may have periodically caused knickpoint migration and incision to slow and possibly stop, allowing lateral erosion and floodplain formation to dominate. A decline in sediment flux from stabilizing incised tributary

  10. Effect of morselized bones on binding of the canine hydroxyapatite-coated femoral stem

    Institute of Scientific and Technical Information of China (English)

    SONG Ke-guan; MA De-sheng; HOU Jian-wen; WANG Huan; YAN Jing-long; YU Zhan-ge; LIANG Zhi-zhong

    2010-01-01

    Background Non-cement femoral stems are recognized in clinical use, but there are still some problems. The aim of this research was to make non-cement femoral stems to be press-fit with the medullary cavity. Methods Twenty-four healthy adult mongrel dogs were randomly divided into experimental and control groups. In the right hip joint, an artificial femoral bone replacement surgery was conducted. For the experimental group, the replacement surgery of hydroxyapatite (HA)-coated femoral stems was done, while autogeneous morselized bone was implanted into the medullary cavity. For the control group, morselized bone was not implanted. At postoperative 1, 3, 6 months, a test for interfacial shear characteristics was conducted in the MTS810 Tester. The comparison between the two groups' bone-prostheses in shear strength for their interface from shearing destruction was made. A histological observation to check prosthesis-bone interface contact ratios and bone growth was carried out. Results For the experimental group, shear strength was 0.317 MPa in 1 month, 1.447 MPa in 3 months, and 1.621 MPa in 6 months. For the control group, shear strength was 0.195 MPa in 1 month, 1.023 MPa in 3 months, and 1.483 MPa in 6 months. The difference was statistically significant. Stereomicroscope-based observation showed that the number of trabecular bones in the experimental group was larger than that of the control group, and bone growth of the former group was better than that of the latter group. Inverted microscopic observation showed that the binding degree between the prosthesis and trabecular bone of the experimental group was higher than that of the control group. Comparatively, the experimental group's trabecular bone had more stromal cells. Conclusions The morselized bones can effectively improve the biological bonding strength and bone-contact ratios in the short term for the HA-coated femoral stem and accelerate the bonding process. The use of morselized autogenous bones

  11. Dust torus around Mars

    Science.gov (United States)

    Juhasz, Antal; Horanyi, Mihaly

    1995-01-01

    We investigate the orbital dynamics of small dust particles generated via the continuous micrometeoroid bombardment of the Martian moons. In addition to Mar's oblateness, we also consider the radiation pressure perturbation that is complicated by the planet's eccentric orbit and tilted rotational axis. Considering the production rates and the lifetimes of dust grains, we show that particles from Deimos with radii of about 15 micrometers are expected to dominate the population of a permanently present and tilted dust torus. This torus has an estimated peak number density of approximately equals 5 x 10(exp -12)/cu cm and an optical depth of approximately equals 4 x 10(exp -8).

  12. 腹式呼吸和自生训练对心率及指温影响的初步探讨%The Effects of Abdominal Breathing and Autogenic Training on Heart Rate and Finger Temperature

    Institute of Scientific and Technical Information of China (English)

    张秀阁; 闫克乐

    2001-01-01

    Objective: To examine the effects of autogenic training and abdominal breathing on heart rate and finger temperature. Methods: Forty-five healthy female university students were randomly assigned to three groups:control、autogenic training and deep abdominal breathing groups, and their physiological effects were compared. Results:The result of this experiment showed that both autogenic training and abdominal breathing increased finger temperature significantly, however, the increase magnitude didn't show significant differences in two groups.During autogenic training, the heart rate of autogenic training group declined significantly,the heart rate of deep abdominal breathing group decreased significantly after deep abdominal breathing. The decrease magnitude between the three groups showed no significant differences. Conclusion: Both the present techniques can decrease heart rate and increase finger temperature.

  13. Dust mite (image)

    Science.gov (United States)

    This is a magnified photograph of a dust mite. Mites are carriers (vectors) of many important diseases including typhus (scrub and murine) and rickettsialpox. (Image courtesy of the Centers for Disease ...

  14. Adhesion of Lunar Dust

    Science.gov (United States)

    Walton, Otis R.

    2007-04-01

    This paper reviews the physical characteristics of lunar dust and the effects of various fundamental forces acting on dust particles on surfaces in a lunar environment. There are transport forces and adhesion forces after contact. Mechanical forces (i.e., from rover wheels, astronaut boots and rocket engine blast) and static electric effects (from UV photo-ionization and/or tribo-electric charging) are likely to be the major contributors to the transport of dust particles. If fine regolith particles are deposited on a surface, then surface energy-related (e.g., van der Walls) adhesion forces and static-electric-image forces are likely to be the strongest contributors to adhesion. Some measurement techniques are offered to quantify the strength of adhesion forces. And finally some dust removal techniques are discussed.

  15. Nano Dust Analyzer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop a new highly sensitive instrument to confirm the existence of the so-called nano-dust particles, characterize their impact parameters, and...

  16. Composite Circumstellar Dust Grains

    CERN Document Server

    Gupta, Ranjan; Dutta, Rajeshwari

    2016-01-01

    We calculate the absorption efficiencies of composite silicate grains with inclusions of graphite and silicon carbide in the spectral range 5--25$\\rm \\mu m$. We study the variation in absorption profiles with volume fractions of inclusions. In particular we study the variation in the wavelength of peak absorption at 10 and 18$\\rm \\mu m$. We also study the variation of the absorption of porous silicate grains. We use the absorption efficiencies to calculate the infrared flux at various dust temperatures and compare with the observed infrared emission flux from the circumstellar dust around some M-Type \\& AGB stars obtained from IRAS and a few stars from Spitzer satellite. We interpret the observed data in terms of the circumstellar dust grain sizes; shape; composition and dust temperature.

  17. Migration of Interplanetary Dust

    OpenAIRE

    Ipatov, S. I.; Mather, J. C.; Taylor, P.A.

    2003-01-01

    We numerically investigate the migration of dust particles with initial orbits close to those of the numbered asteroids, observed trans-Neptunian objects, and Comet Encke. The fraction of silicate asteroidal particles that collided with the Earth during their lifetime varied from 1.1% for 100 micron particles to 0.008% for 1 micron particles. Almost all asteroidal particles with diameter d>4 microns collided with the Sun. The peaks in the migrating asteroidal dust particles' semi-major axis d...

  18. Newton to Einstein — dust to dust

    International Nuclear Information System (INIS)

    We investigate the relation between the standard Newtonian equations for a pressureless fluid (dust) and the Einstein equations in a double expansion in small scales and small metric perturbations. We find that parts of the Einstein equations can be rewritten as a closed system of two coupled differential equations for the scalar and transverse vector metric perturbations in Poisson gauge. It is then shown that this system is equivalent to the Newtonian system of continuity and Euler equations. Brustein and Riotto (2011) conjectured the equivalence of these systems in the special case where vector perturbations were neglected. We show that this approach does not lead to the Euler equation but to a physically different one with large deviations already in the 1-loop power spectrum. We show that it is also possible to consistently set to zero the vector perturbations which strongly constrains the allowed initial conditions, in particular excluding Gaussian ones such that inclusion of vector perturbations is inevitable in the cosmological context. In addition we derive nonlinear equations for the gravitational slip and tensor perturbations, thereby extending Newtonian gravity of a dust fluid to account for nonlinear light propagation effects and dust-induced gravitational waves

  19. Audio-Visual and Autogenic Relaxation Alter Amplitude of Alpha EEG Band, Causing Improvements in Mental Work Performance in Athletes.

    Science.gov (United States)

    Mikicin, Mirosław; Kowalczyk, Marek

    2015-09-01

    The aim of the present study was to investigate the effect of regular audio-visual relaxation combined with Schultz's autogenic training on: (1) the results of behavioral tests that evaluate work performance during burdensome cognitive tasks (Kraepelin test), (2) changes in classical EEG alpha frequency band, neocortex (frontal, temporal, occipital, parietal), hemisphere (left, right) versus condition (only relaxation 7-12 Hz). Both experimental (EG) and age-and skill-matched control group (CG) consisted of eighteen athletes (ten males and eight females). After 7-month training EG demonstrated changes in the amplitude of mean electrical activity of the EEG alpha bend at rest and an improvement was significantly changing and an improvement in almost all components of Kraepelin test. The same examined variables in CG were unchanged following the period without the intervention. Summing up, combining audio-visual relaxation with autogenic training significantly improves athlete's ability to perform a prolonged mental effort. These changes are accompanied by greater amplitude of waves in alpha band in the state of relax. The results suggest usefulness of relaxation techniques during performance of mentally difficult sports tasks (sports based on speed and stamina, sports games, combat sports) and during relax of athletes. PMID:26016588

  20. Workability’s recreation methodic with application of cupping massage and autogenic training of women student teams’ basketball players

    Directory of Open Access Journals (Sweden)

    Kozina Zh.L.

    2015-04-01

    Full Text Available Purpose: to experimentally subsituate effectiveness of non traditional complex methodic of recreation in female basketball players’ training process. Material: 22 basketball players of women student’s team participated in the research. Pedagogic testing was conducted by 12 tests in special physical and technical fitness. Psycho-physiological testing was conducted by program PSYCHO-DIAGNOSTIC. Groups were trained by identical programs during 9 weeks. Results: we authors observed increased physical and technical fitness of basketball players. Besides, quantity of mistakes in response to visual irritator reduced. It indirectly witnesses about strengthening of nervous processes. There was registered influence of mind on quality of organism’s recreation after physical loads. Conclusions: the authors recommend methodic of cupping massage, combined with autogenic training. Autogenic training implies repeated pronouncing by instructor (or independently by sportswomen of text, describing coming turn by turn natural images. Peculiarities of massage were influence of massage passes on muscles and ligaments. Cupping massage was used after warming up classic massage techniques.

  1. One-sided laser beam welding of autogenous T-joints for 6013-T4 aluminium alloy

    International Nuclear Information System (INIS)

    Highlights: • We report autogenous T-joints of the 6013-T4 produced by one-sided laser welding. • It is investigated the influence of the process parameters on the weld features. • Beam focal positioning on the sample is a critical parameter in the weld quality. • Tensile strength has some dependence with sheet rolling direction jointed by laser. - Abstract: Autogenous T-joints for aluminium skin-stringer component performed by one-sided laser beam welding process was conducted using a high power Yb-fiber laser. The influence of the shielding gas, seam angle, beam focal position, and beam positioning relative to weld centerline were investigated regarding to weld microstructural features. The joint mechanical behavior was evaluated concerning to the sheet rolling directions. It was observed that a precise control of the process parameters enabled to obtain weld beads with acceptable dimensional and geometric characteristics and minimizing weld defects. Helium shielding gas produced higher aspect ratio welds than those with pure argon. Although, pores were observed in the fusion zone, they represented only about 5% of the weld bead area. The optimal beam positioning should remain up to 0.2 mm relative to junction line, for seam angles between 10° and 15°. The weld mechanical behavior depended on the sheet rolling direction. Joint efficiency up to 85% were obtained after hoop tensile tests when the weld bead longitudinal-section was perpendicular to skin rolling direction and parallel to the stringer rolling direction

  2. RegA protein of bacteriophage T4D: identification, schedule of synthesis, and autogenous regulation

    International Nuclear Information System (INIS)

    Proteins labeled with 14C-amino acids after infection of Escherichia coli B by T4 phage were examined by electrophoresis in the presence of sodium dodecyl sulfate. Four regA mutants (regA1, regA8, regA11, and regA15) failed to make a protein having a molecular weight of about 12,000, whereas mutant regA9 did make such a protein; regA15 produced a new, apparently smaller protein that was presumably a nonsense fragment, whereas regA11 produced a new, apparently larger protein. We conclude that the 12,000-dalton protein was the product of the regA gene. The molecular weight assignment rested primarily on our finding that the regA protein had the same mobility as the T4 gene 33 protein, which we identified by electrophoresis of whole-cell extracts of E. coli B infected with a gene 33 mutant, amE1120. Synthesis of wild-type regA protein occurred from about 3 to 11 min after infection at 370C in the DNA+ state and extended to about 20 min in the DNA- state. However, synthesis of the altered regA proteins of regA9, regA11, and regA15 occurred at a higher rate and for a much longer period in both the DNA+ and DNA- states; thus, the regA gene is autogenously regulated. At 300C, both regA9 and regA11 exhibited partial regA function by eventually shutting off the synthesis of many T4 early proteins; the specificity of this shutoff differed between these two mutants. We also obtainedevidence that the regA protein is not Stevens's polypeptide 3. As a technical point, we found that, when quantitating acid-precipitable radioactivity in protein samples containing sodium dodecyl sulfate, it was necessary to use 15 to 20% trichloroacetic acid; use of 5% acid, e.g., resulted in loss of over half of the labeled protein

  3. Secondary arteriovenous fistulas: converting prosthetic AV grafts to autogenous dialysis access.

    Science.gov (United States)

    Slayden, Geoffrey C; Spergel, Lawrence; Jennings, William C

    2008-01-01

    complications of AVGs may be resolved by conversion to a SAVF. Further, the limited lifespan of AVGs and the superiority of AVFs dictates that a plan be in place to transition the AVG patient to an AVF. Most, if not all, hemodialysis patients whose access is an AVG will have one or more anatomic sites and vessels suitable for an autogenous SAVF. Vessel mapping is critical in the evaluation of failing AVGs and in preparation for a SAVF. Cumulative patency rates exceeded 90% at 12 months for SAVFs in both patient groups in this report. The need for catheters was dramatically less in the patient group with an established SAVF conversion plan. PMID:18627564

  4. The Global Geometry of River Drainage Basins and the Signature of Tectonic and Autogenic Processes

    Science.gov (United States)

    Giachetta, E.; Willett, S.

    2015-12-01

    The plan-form structure of the world's river basins contains extensive information regarding tectonic, paleo-geographic and paleo-climate conditions, but interpretation of this structure is complicated by the need to disentangle these processes from the autogenic behavior of fluvial processes. One method of interpreting this structure is by utilizing the well-established scaling between drainage area and channel slope. Integration of this scaling relationship predicts a relationship between channel length and downstream integrated drainage area, referred to in recent studies as χ (Willett et al., 2014). In this paper, we apply this methodology at a continental scale by calculating χ for the world's river networks using hydrological information from the HydroSHED (Hydrological data and maps based on SHuttleElevation Derivatives at multiple Scales) suite of geo-referenced data sets (drainage directions and flow accumulations). River pixels were identified using a minimum drainage area of 5 km2. A constant value of m/n of 0.45 was assumed. We applied a new method to correct χ within closed basins where base level is different from sea level. Mapping of χ illustrates the geometric stability of a river network, thus highlighting where tectonic or climatic forcing has perturbed the shape and geometry. Each continent shows characteristic features. Continental rift margins on all continents show clear asymmetric escarpments indicating inland migration. Active orogenic belts break up older river basins, but are difficult to interpret because of spatially variable uplift rates. Regions of recent tilting are evident even in cratonic areas by lateral reorganizations of basins. Past and pending river captures are identified on all continents. Very few regions on Earth appear to be in near-equilibrium, though some are identified; for example the Urals appears to provide a stable continental divide for Eurasia. Our analysis of maps of χ at the global scale quantifies a

  5. [Bone diseases].

    Science.gov (United States)

    Uebelhart, Brigitte; Rizzoli, René

    2016-01-13

    Calcium intake shows a small impact on bone mineral density and fracture risk. Denosumab is a more potent inhibitor of bone resorption than zoledronate. Abaloparatide, PTHrP analog, increases bone mineral density and decreases fracture incidence. Teriparatide could be delivered via a transdermic device. Romosozumab and odanacatib improve calculated bone strength. Sequential or combined treatments with denosumab and teriparatide could be of interest, but not denosumab followed by teriparatide. Fibrous dysplasia, Paget disease and hypophosphatasia are updated, as well as atypical femoral fracture and osteonecrosis of the jaw. PMID:26946704

  6. Fractal dust grains in plasma

    Energy Technology Data Exchange (ETDEWEB)

    Huang, F. [College of Science, China Agricultural University, Beijing 100083 (China); Peng, R. D. [State Key Laboratory of Coal Resources and Safe Mining, China University of Mining and Technology, Beijing 100083 (China); Liu, Y. H. [Institute of Complexity Science, Qingdao University, Qingdao 266071 (China); Chen, Z. Y. [Department of Physics, Beijing University of Chemical Technology, Beijing 100029 (China); Ye, M. F.; Wang, L. [Institute of Physics, Chinese Academy of Science, Beijing 100190 (China)

    2012-09-15

    Fractal dust grains of different shapes are observed in a radially confined magnetized radio frequency plasma. The fractal dimensions of the dust structures in two-dimensional (2D) horizontal dust layers are calculated, and their evolution in the dust growth process is investigated. It is found that as the dust grains grow the fractal dimension of the dust structure decreases. In addition, the fractal dimension of the center region is larger than that of the entire region in the 2D dust layer. In the initial growth stage, the small dust particulates at a high number density in a 2D layer tend to fill space as a normal surface with fractal dimension D = 2. The mechanism of the formation of fractal dust grains is discussed.

  7. Talking Bones.

    Science.gov (United States)

    Johnson, Jaclyn; Kassing, Sharon

    2002-01-01

    Describes cooperation with the Saint Louis Zoo to provide opportunities for elementary school students to learn about bones, how animals move, what they eat, and how much they grow. Uses biofacts which include bones, skulls, and other parts to make the laboratory a hands-on experience for students. (YDS)

  8. Bone Markers

    Science.gov (United States)

    ... bone turnover: C-telopeptide (C-terminal telopeptide of type 1 collagen (CTx)) – a marker for bone resorption. It is ... resorption include: N-telopeptide (N-terminal telopeptide of type 1 collagen (NTx)) – a peptide fragment from the amino terminal ...

  9. Complications of massive allograft reconstruction for bone tumors

    Directory of Open Access Journals (Sweden)

    Abolhasan Borjian

    2006-11-01

    Full Text Available BACKGROUND: Since the evolution of multi-drug chemotherapy and radiotherapy and new sophisticated surgical techniques, limb salvage and reconstruction, rather than amputation, has become the preferred treatment for patients with bone tumors. One option is allograft replacement. Although allograft has several advantages, it is not without complications. This study was performed to observe these complications in a group of patients treated with allograft replacement for bone tumor resection. The purpose was to gain an overview of the factors predisposing to these complications to minimize their occurrence. METHODS: This retrospective study was performed on patients with benign aggressive and malignant bone tumors undergoing limb reconstruction with allograft between 1997 and 2005 in Al-Zahra and Kashani Hospitals in Isfahan, Iran. Data was collected from patient files, clinical notes, radiographs and a recent physical examination. Complications including local recurrence, fracture of allograft, fixation failure, nonunion, infection, skin necrosis and neurological damage were recorded. RESULTS: Sixty patients including 39 males and 21 females were studied. The mean age of patients was 23 ± 11.7 years. The mean follow-up interval was 28.1 ± 12.4 months (mean ± SD. Complications were allograft fracture in 20%, local recurrence in 16%, fixation failure in 11%, nonunion in 6%, infection in 6%, skin necrosis in 6%, and peroneal nerve palsy in 1% of cases. Most local recurrences (60% were those with a mal-performed biopsy. Most allograft fractures occurred when a short plate was used. CONCLUSIONS: Allograft replacement for bone tumors remains a valid option. To avoid complications, biopsy should be done by a trained surgeon in bone oncology. A long plate is recommended for fixation. Sterility and graft processing must be optimal. Autogenous bone graft must be added at host-allograft junction. KEY WORDS: Bone tumors, bone allograft, limb

  10. Bone densitometry

    DEFF Research Database (Denmark)

    Ravn, Pernille; Alexandersen, P; Møllgaard, A

    1999-01-01

    The bisphosphonates have been introduced as alternatives to hormone replacement therapy (HRT) for the treatment and prevention of postmenopausal osteoporosis. The expected increasing application in at clinical practice demands cost-effective and easily handled methods to monitor the effect on bone....... The weak response at the distal forearm during antiresorptive treatment has restricted the use of bone densitometry at this region. We describe a new model for bone densitometry at the distal forearm, by which the response obtained is comparable to the response in other regions where bone densitometry...... is much more expensive and technically complicated. By computerized iteration of single X-ray absorptiometry forearm scans we defined a region with 65% trabecular bone. The region was analyzed in randomized, double-masked, placebo- controlled trials: a 2-year trial with alendronate (n = 69), a 1-year...

  11. Dust exposure in Finnish foundries.

    Science.gov (United States)

    Siltanen, E; Koponen, M; Kokko, A; Engström, B; Reponen, J

    1976-01-01

    Dust measurements were made in 51 iron, 9 steel, and 8 nonferrous foundries, at which 4,316 foundrymen were working. The sampling lasted at least two entire shifts or work days continuously during various operations in each foundry. The dust samples were collected at fixed sites or in the breathing zones of the workers. The mass concentration was determined by weighing and the respirable dust fraction was separated by liquid sedimentation. The free silica content was determined by X-ray diffraction. In the study a total of 3,188 samples were collected in the foundries and 6,505 determinations were made in the laboratory. The results indicated a definite difference in the dust exposure during various operations. The highest dust exposures were found during furnace, cupola, and pouring ladle repair. During cleaning work, sand mixing, and shake-out operations excessive silica dust concentrations were also measured. The lowest dust concentrations were measured during melting and pouring operations. Moderate dust concentrations were measured during coremaking and molding operations. The results obtained during the same operations of iron and steel foundries were similar. The distribution of the workers into various exposure categories, the content of respirable dust and quartz, the correlation between respirable dust and total dust, and the correlation between respirable silica and total dust concentrations are discussed. Observations concerning dust suppression and control methods are briefly considered. PMID:184524

  12. Bone Augmentation in Rabbit Tibia Using Microfixed Cobalt-Chromium Membranes with Whole Blood and Platelet-Rich Plasma

    Directory of Open Access Journals (Sweden)

    Oscar A. Decco

    2015-07-01

    Full Text Available Background: Bone augmentation is a subject of intensive investigation in regenerative bone medicine and constitutes a clinical situation in which autogenous bone grafts or synthetic materials are used to aid new bone formation. Method: Based on a non-critical defect, Co-Cr barrier membranes were placed on six adult Fauve de Bourgogne rabbits, divided into two groups: whole blood and PRP. Three densitometric controls were performed during the experiment. The animals were euthanized at 30, 45, 60, and 110 days. The presence of newly formed bone was observed. Samples for histological studies were taken from the augmentation center. Results: External and internal bone tissue augmentation was observed in almost all cases. Significant differences between PRP- and whole blood–stimulated bone augmentation were not observed. At 60 days, bones with PRP presented higher angiogenesis, which may indicate more proliferation and cellular activity. Conclusion: PRP activates the bone regeneration process under optimized conditions by stimulation of osteoblast proliferation after six weeks, when a significant difference in cellular activity was observed. Membranes could stimulate bone augmentation at the site of placement and in the surrounding areas.

  13. Analytical Study of Nonlinear Dust Acoustic Waves in Two-Dimensional Dust Plasma with Dust Charge Variation

    Institute of Scientific and Technical Information of China (English)

    LIN Chang; ZHANG Xiu-Lian

    2005-01-01

    The nonlinear dust acoustic waves in two-dimensional dust plasma with dust charge variation is analytically investigated by using the formally variable separation approach. New analytical solutions for the governing equation of this system have been obtained for dust acoustic waves in a dust plasma for the first time. We derive exact analytical expressions for the general case of the nonlinear dust acoustic waves in two-dimensional dust plasma with dust charge variation.

  14. Dust-Dust Collisional Charging and Lightning in Protoplanetary Discs

    CERN Document Server

    Muranushi, Takayuki

    2009-01-01

    We study the role of dust-dust collisional charging in protoplanetary discs. We show that dust-dust collisional charging becomes an important process in determining the charge state of dust and gas, if there is dust enhancement and/or dust is fluffy, so that dust surface area per disc volume is locally increased. We solve the charge equilibrium equations for various disc environments and dust condensation $\\eta$ (dust number density of the considered region divided by the fiducial value), using general purpose graphic processors (GPGPU) and {\\sc cuda} programming language. We found that as dust condensation $\\eta$ increases, the charge distribution experience four phases. In one of these phases the electrostatic field $E$ caused by dust migration increases as $E \\propto \\eta^4$. As a result, macroscopic electric discharge takes place typically at $\\eta = 30 \\sim 300$. We present a model that describes the charge exchange processes in the discs as an electric circuit. We estimate the total energy, intensity an...

  15. Dust-Plasma Interactions

    International Nuclear Information System (INIS)

    The objective of our theoretical research under this grant over the past 3 years was to develop new understanding in a range of topics in the physics of dust-plasma interactions, with application to space and the laboratory. We conducted studies related to the physical properties of dust, waves and instabilities in both weakly coupled and strongly coupled dusty plasmas, and innovative possible applications. A major consideration in our choice of topics was to compare theory with experiments or observations, and to motivate new experiments, which we believe is important for developing this relatively new field. Our research is summarized, with reference to our list of journal publications.

  16. Electrostatic Characterization of Lunar Dust

    Science.gov (United States)

    2008-01-01

    To ensure the safety and success of future lunar exploration missions, it is important to measure the toxicity of the lunar dust and its electrostatic properties. The electrostatic properties of lunar dust govern its behavior, from how the dust is deposited in an astronaut s lungs to how it contaminates equipment surfaces. NASA has identified the threat caused by lunar dust as one of the top two problems that need to be solved before returning to the Moon. To understand the electrostatic nature of lunar dust, NASA must answer the following questions: (1) how much charge can accumulate on the dust? (2) how long will the charge remain? and (3) can the dust be removed? These questions can be answered by measuring the electrostatic properties of the dust: its volume resistivity, charge decay, charge-to-mass ratio or chargeability, and dielectric properties.

  17. Autogenous Tumbling Media Assessment to Clean Weathered Surfaces of Waste-Rock Particles from a Basalt Quarry

    Directory of Open Access Journals (Sweden)

    Baran Tufan

    2015-06-01

    Full Text Available In this study, the optimum feed composition in autogenous tumbling of basalt waste-rock particles to clean their weathered surface was determined. The weathered surfaces of basalt are generally cut out consequent to extraction of basalt columns in quarry operations. The inefficiently cut out portions of basalt cause formation of huge quarry waste dumps causing visual pollution on roadsides. Mixtures of different particle size fractions of basalt waste-rock particles were experimented to achieve the optimum feed material composition. The minimum loss of commercially available basalt particles and maximum clear surface was intended. The results were compared with respect to weight loss (% and reflectance values of used and generated samples.

  18. Healing patterns of critical size bony defects in rats after grafting with bone substitutes soaked in recombinant human bone morphogenetic protein-2: histological and histometric evaluation.

    Science.gov (United States)

    Mokbel, N; Naaman, N; Nohra, J; Badawi, N

    2013-09-01

    The aim of the study was to evaluate the effect of different bone substitutes soaked in recombinant human bone morphogenetic protein-2 (rhBMP-2) on the healing of critical size defects in calvarial bone. Defects were created in 24 Sprague Dawley rats. The rhBMP-2 was diluted to obtain a final concentration of 0.2mg/ml. Rats were divided into four groups and treated as follows: in the first group the defect was filled with anorganic bovine bone mineral (ABBM) and rhBMP-2, the second group was treated with freeze-dried bone allograft (FDBA) and rhBMP-2, and the third group was treated with autogenous bone (AUTO). In the control group the defects were left untreated. Animals were killed after 8weeks and calcified histological sections prepared. Histometric measurements showed that mean (SD) bone formation was 4.00 (1.69)mm(2) in the ABBM group, 2.56 (1.06)mm(2) in the FDBA group, and 2.30 (0.34)mm(2) in the AUTO group. The difference between the ABBM group and the other 3 groups was significant (p<0.0001) with a mean bone formation of 0.82 (0.25)mm(2) in the control group. There was no significant difference between the FDBA and the AUTO groups (p=0.96). Within the limits of this study we concluded that the addition of rhBMP-2 to bone substitutes was efficacious in regenerating bone in critical size bone defects in calveria in rats. PMID:22939894

  19. The effects of the centrifugation speed on the survival of autogenous fat grafts in a rat model.

    Science.gov (United States)

    Bozkurt, Mehmet; Kapı, Emin; Şirinoğlu, Hakan; Güvercin, Emre; Filinte, Gaye Taylan; Filinte, Deniz

    2016-06-01

    Purpose The most important problem in fat transplantation is the durability, which is closely associated with the applied technique. This study includes the comparison of different centrifugation speeds on the survival of autogenous fat grafts in rats. Materials and methods Forty-nine Sprague-Dawley rats were divided into seven groups and the left inguinal fat pad was extracted and re-implanted under the scalp after performing appropriate preparation processes. In the first group the fatty tissue was re-implanted in en-bloc fashion and in the second group it was re-implanted after trimming. After trimming, centrifugation with a G-force of 111.8 (1000 rpm) was performed in the third group, 447.2 (2000 rpm) in the fourth group, 1006.2 (3000 rpm) in the fifth group, 1788.8 (4000 rpm) in the sixth group, and 2795 (5000 rpm) in the seventh group for 4 minutes. The fat grafts were taken after 3 months and histopathological and statistical evaluations were performed. Results The rate of viable fat grafts was significantly higher in the 4th and 5th groups comparing to the first three groups. Total weight and volume amounts of the 4th and 5th groups were also significantly higher comparing to the first three groups. Conclusion Maximal long-term durability and fat cell viability results were obtained in the groups with 2000 rpm or 447.2 G-force/4 minutes and 3000 rpm or 1006.2 G-force/4 minutes centrifugation speed, indicating that 4 minutes centrifugation with an average G-force of 698.75 or 2500 rpm provides the best results for the survival of autogenous fat grafts. PMID:26898924

  20. Significance of changes in transforming growth factor-β mRNA levels in autogenous vein grafts

    Institute of Scientific and Technical Information of China (English)

    尤文俊; 萧明第; 袁忠祥

    2004-01-01

    Background This study was designed to investigate changes in mRNA levels of transforming growth factor-β(TGF-β), collagen Ⅰ, and collagen Ⅲ in autogenous vein grafts. Methods Twenty-four New Zealand rabbits were randomly divided into 4 groups with 6 rabbits each. The external jugular veins of the New Zealand rabbits were harvested and grafted into the ipsilateral carotid artery. All rabbits were fed with a standard diet. After the operation, the rabbits were sacrificed at 1, 2, 3, or 4 weeks. TGF-β, collagen Ⅰ, and collagen Ⅲ mRNA levels in the venous grafts were measured by semiquantitative methods at every time point. The contralateral external jugular veins were also harvested and analyzed as controls. Glyceraldehyde-3-phosphate dehydrogenase was used as an internal standard to normalize all samples for potential variations in mRNA content. In order to observe the expression of TGF-β protein, immunohistochemical SABC methods were used. Results One week postoperation, the mRNA level of TGF-β was upregulated to 1.73±0.19 in the vein graft and 1.21±0.16 in the control vein (P<0.01). High mRNA levels were maintained until week 4 postoperation. The mRNA levels of collagen Ⅰ and collagen Ⅲ were also significantly increased to 2.18±0.21 versus 1.12±0.24 and 1.08±0.13 versus 0.83±0.12, respectively (P<0.05). Immunohistochemical staining revealed a higher density of TGF-β expression in the vein grafts.Conclusions An uninterrupted increase in mRNA levels of TGF-β, collagen Ⅰ, and collagen Ⅲ is observed in autogenous vein grafts. This increase may be the major cause of intimal hyperplasia, sclerosis, and even graft failure.

  1. Dust-Plasma Interactions

    International Nuclear Information System (INIS)

    Our theoretical research on dust-plasma interactions has concentrated on three main areas: (a)studies of grain charging and applications; (b) waves and instabilities in weakly correlated dusty plasma with applications to space and laboratory plasmas; (c) waves in strongly coupled dusty plasmas.

  2. Dust devil dynamics

    Science.gov (United States)

    Horton, W.; Miura, H.; Onishchenko, O.; Couedel, L.; Arnas, C.; Escarguel, A.; Benkadda, S.; Fedun, V.

    2016-06-01

    A self-consistent hydrodynamic model for the solar heating-driven onset of a dust devil vortex is derived and analyzed. The toroidal flows and vertical velocity fields are driven by an instability that arises from the inversion of the mass density stratification produced by solar heating of the sandy surface soil. The nonlinear dynamics in the primary temperature gradient-driven vertical airflows drives a secondary toroidal vortex flow through a parametric interaction in the nonlinear structures. While an external tangential shear flow may initiate energy transfer to the toroidal vortex flow, the nonlinear interactions dominate the transfer of vertical-radial flows into a fast toroidal flow. This secondary flow has a vertical vorticity, while the primary thermal gradient-driven flow produces the toroidal vorticity. Simulations for the complex nonlinear structure are carried out with the passive convection of sand as test particles. Triboelectric charging modeling of the dust is used to estimate the charging of the sand particles. Parameters for a Dust Devil laboratory experiment are proposed considering various working gases and dust particle parameters. The nonlinear dynamics of the toroidal flow driven by the temperature gradient is of generic interest for both neutral gases and plasmas.

  3. Left in the Dust

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    NASA's Stardust spacecraft ended its seven-year voyage January 15 after a safe landing on earth, bringing back a capsule of comet particles and samples of interstellar dust that exceeded the loftiest of expectations of mission scientists. The ensuing studies of the cosmic treasure are expected to shed light on the origins of the solar system and earth itself.

  4. Dust Devil Dynamics

    Science.gov (United States)

    Correa, C. E.; Escarguel, A.; Horton, W.; Arnas, C.; Couedel, L.; Benkadda, S.

    2013-12-01

    A self-consistent hydrodynamic model for the onset of a dust devil vortex is derived and analyzed. The horizontal toroidal flow and vertical velocity field are driven by the vertical temperature gradient instability of gravity waves. The critical temperature gradient is derived and the associated eigenmodes for simple models are given. The nonlinear dynamics in the vertical/horizontal flows drive the toroidal flow through a parametric decay process. Methods developed for triboelectric charging of dust are used to compute the electric polarization vector from the charging of the sand particles. Elementary comparisons are made with the data from dust devil observations and research and simulations by Farrell et al. 2004, 2006. The parameters for a proposed Dust Devil laboratory experiment at Aix-Marseille University are presented. Following R. L. Miller et al. JGR 2006 estimates are made of the overall contribution to the mid-latitude aerosol layer in the atmosphere that acts to moderate global climate temperature increases through a negative feedback loop. The problem has an analog in terms of the heating of the boron or beryllium coated steel vacuum vessel walls in tokamaks where the core plasma plays the role of the sun and has a temperature (~ 10keV ) that exceeds that of the core of the sun.

  5. Bone Tumor

    Science.gov (United States)

    ... the knee in either the femur (thigh) or tibia (shinbone). Other common locations include the hip and ... bone that is weakened by a tumor to fracture, or break. This may be severely painful. Occasionally, ...

  6. Your Bones

    Science.gov (United States)

    ... a fall! If you play sports like football, soccer, lacrosse, or ice hockey, always wear all the ... to strengthen your bones is through exercise like running, jumping, dancing, and playing sports. Take these steps ...

  7. Antigen-free bovine cancellous bone loaded with recombinant human bone morphogenetic protein-2 for the repair of tibial bone defects in goat model.

    Science.gov (United States)

    Li, Donghai; Deng, Liqing; Yang, Zhouyuan; Xie, Xiaowei; Kang, Pengde; Tan, Zhen

    2016-04-01

    Antigen-free bovine cancellous bone has good performances of porous network structures and mechanics with antigen extracted. To develop a bioactive scaffold for enhancing bone repair and evaluate its biological property, rhBMP-2 loaded with antigen-free bovine cancellous bone was used to treat tibial bone defect. Twenty-four healthy adult goats were chosen to establish goat defects model and randomly divided into four groups. The goats were treated with rhBMP-2/antigen-free bovine cancellous bone scaffolds (group A), autogenous cancellous bone graft (group B), porous tricalciumphosphate scaffolds (group C) and nothing (group D). Animals were evaluated with radiological and histological methods at 4, 8 and 12 weeks after surgery. The gray value of radiographs was used to evaluate the healing of the defects, which revealed that the group A had a better outcome of defect healing compared with group C at 4, 8 and 12 weeks, respectively (p difference between groups A and B was without significance at each time (p > 0.05). The newly formed bone area was calculated from histological sections, and the results indicated that the amount of new bone in group A increased significantly compared with that in group C (p  0.05) at 4, 8 and 12 weeks, respectively. In addition, the expression of collagen I and vascular endothelial growth factor by real-time polymerase chain reaction at 12 weeks in group A was significantly higher than that in group C (p = 0.034, p = 0.032, respectively), but no significant differences were found when compared with that in group B (p = 0.36, p = 0.54, respectively). At the same time, group C presented better results than group D on bone defects healing. Therefore, the composites of antigen-free bovine cancellous bone loaded with rhBMP-2 have a good osteoinductive activity and capacity to promote the repair of bone defects. PMID:26801475

  8. Dust processing in elliptical galaxies

    CERN Document Server

    Hirashita, Hiroyuki; Villaume, Alexa; Srinivasan, Sundar

    2015-01-01

    We reconsider the origin and processing of dust in elliptical galaxies. We theoretically formulate the evolution of grain size distribution, taking into account dust supply from asymptotic giant branch (AGB) stars and dust destruction by sputtering in the hot interstellar medium (ISM), whose temperature evolution is treated by including two cooling paths: gas emission and dust emission (i.e. gas cooling and dust cooling). With our new full treatment of grain size distribution, we confirm that dust destruction by sputtering is too efficient to explain the observed dust abundance even if AGB stars continue to supply dust grains, and that, except for the case where the initial dust-to-gas ratio in the hot gas is as high as $\\sim 0.01$, dust cooling is negligible compared with gas cooling. However, we show that, contrary to previous expectations, cooling does not help to protect the dust; rather, the sputtering efficiency is raised by the gas compression as a result of cooling. We additionally consider grain grow...

  9. Dust arising during steelmaking processes

    Directory of Open Access Journals (Sweden)

    P. Popielska-Ostrowska

    2012-12-01

    Full Text Available Purpose: This paper describes the dust arising during steelmaking processes.Design/methodology/approach: Steelmaking dusts may be a viable alternative for obtaining valuable and widely used metal which is zinc. On the other hand, heavy metals, it was as dangerous to the environment, and this in turn means that development of steelmaking dusts in the best possible way.Findings: The analysis of the formation of steelmaking dust.Research limitations/implications: Understanding the mechanism of steelmaking dusts will help to increase the participation of zinc recycling from wastes.Practical implications: Contained zinc in the dust can be recovered from the positive economic effect, and neutralization of hazardous waste to the desired environmental effect.Originality/value: Description of the mechanism of steelmaking dust, with particular emphasis on the distribution of zinc. The information is very important in the development of metal recovery technology from waste.

  10. Bone densitometer

    International Nuclear Information System (INIS)

    In an x-ray bone densitometer, special calibration techniques are employed to accommodate variations. In one aspect, a bone-like calibration material is interposed and the system determines the calibration data from rays passing only through flesh. In another aspect, a rotating device carries the calibration material through the beam. The specific densitometer shown uses an x-ray tube operated at two different voltages to generate a pencil beam, the energy levels of the x-ray photons being a function of the voltage applied. An integrating detector is timed to integrate the detected signal of the patient-attenuated beam over each pulse, the signals are converted to digital values and a digital computer converts the set of values produced by the raster scan into a representation of the bone density of the patient. Multiple reference detectors with differing absorbers are used by the system to continuously correct for variation in voltage and current of the x-ray tube. Calibration is accomplished by the digital computer on the basis of passing the pencil beam through known bone-representing substance as the densitometer scans portions of the patient having bone and adjacent portions having only flesh. A set of detected signals affected by the calibration substance in regions having only flesh is compared by the computer with a set of detected signals unaffected by the calibration material

  11. Dust in External Galaxies

    OpenAIRE

    Calzetti, Daniela

    2009-01-01

    Existing (Spitzer Space Telescope) and upcoming (Herschel Space Telescope) facilities are deepening our understanding of the role of dust in tracing the energy budget and chemical evolution of galaxies. The tools we are developing while exploring the local Universe will in turn become pivotal in the interpretation of the high redshift Universe when near--future facilities (the Atacama Large Millimeter Array [ALMA], the Sub--Millimeter Array [SMA], the Large Millimeter Telescope [LMT], the Jam...

  12. PFASs in house dust

    OpenAIRE

    Nizzetto, Pernilla Bohlin; Hanssen, Linda; Herzke, Dorte

    2016-01-01

    NILU has, on behalf of the Norwegian Environment Agency, performed sampling and analysis of house dust from Norwegian households. The goal was to study concentration ranges, and variability between- and within-houses of anionic and volatile per- and polyfluorinated alkyl substances (PFASs), including the regulated PFOA, as well as for total extractable organic fluorine (TEOF). The sampling was done in six separate rooms in six different households. The analysis covered a suite of 20 targeted ...

  13. Transport of Dust Particles in Tokamak Devices

    Energy Technology Data Exchange (ETDEWEB)

    Pigarov, A Y; Smirnov, R D; Krasheninnikov, S I; Rognlien, T D; Rozenberg, M

    2006-06-06

    Recent advances in the dust transport modeling in tokamak devices are discussed. Topics include: (1) physical model for dust transport; (2) modeling results on dynamics of dust particles in plasma; (3) conditions necessary for particle growth in plasma; (4) dust spreading over the tokamak; (5) density profiles for dust particles and impurity atoms associated with dust ablation in tokamak plasma; and (6) roles of dust in material/tritium migration.

  14. Dust, Climate, and Human Health

    Science.gov (United States)

    Maynard, Nancy G.

    2003-01-01

    Air pollution from both natural and anthropogenic causes is considered to be one of the most serious world-wide environment-related health problems, and is expected to become worse with changes in the global climate. Dust storms from the atmospheric transport of desert soil dust that has been lifted and carried by the winds - often over significant distances - have become an increasingly important emerging air quality issue for many populations. Recent studies have shown that the dust storms can cause significant health impacts from the dust itself as well as the accompanying pollutants, pesticides, metals, salt, plant debris, and other inorganic and organic materials, including viable microorganisms (bacteria, viruses and fungi). For example, thousands of tons of Asian desert sediments, some containing pesticides and herbicides from farming regions, are commonly transported into the Arctic during dust storm events. These chemicals have been identified in animal and human tissues among Arctic indigenous populations. Millions of tons of airborne desert dust are being tracked by satellite imagery, which clearly shows the magnitude as well as the temporal and spatial variability of dust storms across the "dust belt" regions of North Africa, the Middle East, and China. This paper summarizes the most recent findings on the effects of airborne desert dust on human health as well as potential climate influences on dust and health.

  15. Nostril Base Augmentation Effect of Alveolar Bone Graft

    Directory of Open Access Journals (Sweden)

    Woojin Lee

    2013-09-01

    Full Text Available Background The aims of alveolar bone grafting are closure of the fistula, stabilization ofthe maxillary arch, support for the roots of the teeth adjacent to the cleft on each side.We observed nostril base augmentation in patients with alveolar clefts after alveolar bonegrafting. The purpose of this study was to evaluate the nostril base augmentation effect ofsecondary alveolar bone grafting in patients with unilateral alveolar cleft.Methods Records of 15 children with alveolar clefts who underwent secondary alveolar bonegrafting with autogenous iliac cancellous bone between March of 2011 and May of 2012 werereviewed. Preoperative and postoperative worm’s-eye view photographs and reconstructedthree-dimensional computed tomography (CT scans were used for photogrammetry. Thedepression of the nostril base and thickness of the philtrum on the cleft side were measuredin comparison to the normal side. The depression of the cleft side pyriform aperture wasmeasured in comparison to the normal side on reconstructed three-dimensional CT.Results Significant changes were seen in the nostril base (P=0.005, the philtrum length(P=0.013, and the angle (P=0.006. The CT measurements showed significant changes in thepyriform aperture (P<0.001 and the angle (P<0.001.Conclusions An alveolar bone graft not only fills the gap in the alveolar process but alsoaugments the nostril base after surgery. In this study, only an alveolar bone graft was performedto prevent bias from other procedures. Nostril base augmentation can be achieved byperforming alveolar bone grafts in children, in whom invasive methods are not advised.

  16. Bone lesion biopsy

    Science.gov (United States)

    Bone biopsy; Biopsy - bone ... needle is gently pushed and twisted into the bone. Once the sample is obtained, the needle is ... sample is sent to a lab for examination. Bone biopsy may also be done under general anesthesia ...

  17. What Is Bone?

    Science.gov (United States)

    ... by your browser. Home Bone Basics What Is Bone? Publication available in: PDF (57 KB) Related Resources ... Men, and Osteoporosis Osteoporosis Prevention For Your Information Bone Remodeling Throughout life, bone is constantly renewed through ...

  18. Calcium and bones

    Science.gov (United States)

    Bone strength and calcium ... calcium (as well as phosphorus) to make healthy bones. Bones are the main storage site of calcium in ... your body does not absorb enough calcium, your bones can get weak or will not grow properly. ...

  19. Facts about Broken Bones

    Science.gov (United States)

    ... White House Lunch Recipes The Facts About Broken Bones KidsHealth > For Kids > The Facts About Broken Bones ... through the skin . continue What Happens When a Bone Breaks? It hurts to break a bone! It's ...

  20. Bone biopsy (image)

    Science.gov (United States)

    A bone biopsy is performed by making a small incision into the skin. A biopsy needle retrieves a sample of bone and it ... examination. The most common reasons for bone lesion biopsy are to distinguish between benign and malignant bone ...

  1. Bone lesion biopsy

    Science.gov (United States)

    Bone biopsy; Biopsy - bone ... is sent to a lab for examination. Bone biopsy may also be done under general anesthesia to ... remove the bone can be done if the biopsy exam shows that there is an abnormal growth ...

  2. A theory for the origin of a self-replicating chemical system. I - Natural selection of the autogen from short, random oligomers

    Science.gov (United States)

    White, D. H.

    1980-01-01

    A general theory is presented for the origin of a self-replicating chemical system, termed an autogen, which is capable of both crude replication and translation (protein synthesis). The theory requires the availability of free energy and monomers to the system, a significant background low-yield synthesis of kinetically stable oligopeptides and oligonucleotides, the localization of the oligomers, crude oligonucleotide selectivity of amino acids during oligopeptide synthesis, crude oligonucleotide replication, and two short peptide families which catalyze replication and translation, to produce a localized group of at least one copy each of two protogenes and two protoenzymes. The model posits a process of random oligomerization, followed by the random nucleation of functional components and the rapid autocatalytic growth of the functioning autogen to macroscopic amounts, to account for the origin of the first self-replicating system. Such a process contains steps of such high probability and short time periods that it is suggested that the emergence of an autogen in a laboratory experiment of reasonable time scale may be possible.

  3. Effect of optimal weld parameters in the microstructure and mechanical properties of autogeneous gas tungsten arc weldments of super-duplex stainless steel UNS S32750

    International Nuclear Information System (INIS)

    Highlights: • Optimization of process parameters in autogeneous GTA welding of UNS S32750. • Effect of optimal parameters on the metallurgical and mechanical properties. • Pensive discussions on the structure – property relationships. - Abstract: The present study reported the optimization of process parameters such as current and welding speed to achieve maximum penetration in the bead on plate Gas Tungsten Arc Welding (GTAW) of super-duplex stainless steel thick plates by autogeneous-automatic mode. Two factor three level Taguchi L9 orthogonal array was employed to determine the maximum penetration. A maximum penetration of 3.4439 mm with a heat input of 1.17 kJ/mm was obtained on employing a current of 250 A and a welding speed of 150 mm/min. Experimental investigations including microstructure and mechanical properties characterization of the weldments were determined from the established optimal parameters. The results showed that the tensile strength and the impact toughness of the joints obtained from autogeneous GTAW process were found to be 851 MPa and 150 J respectively

  4. Sequential Fluorescent Labeling Observation of Maxillary Sinus Augmentation by a Tissue-engineered Bone Complex in Canine Model

    Institute of Scientific and Technical Information of China (English)

    Xin-quan Jiang; Shao-yi Wang; Jun Zhao; Xiu-li Zhang; Zhi-yuan Zhang

    2009-01-01

    Aim To evaluate the effects of maxillary sinus floor elevation by a tissue-engineered bone complex of β-tricalcium phosphate (β-TCP) and autologous osteoblasts in dogs. Methodology Autologous osteoblasts from adult Beagle dogs were cultured in vitro. They were further combined with β-TCP to construct the tissue-engineered bone complex. 12 cases of maxillary sinus floor elevation surgery were made bilaterally in 6 animals and randomly repaired with the following 3 groups of materials: Group A (osteoblasts/β-TCP); Group B (β-TCP); Group C (autogenous bone) (n-4 per group). A polychrome sequential fluorescent labeling was performed post-operatively and the animals were sacrificed 24 weeks after operation for histological observation.Results Our results showed that autologous osteoblasts were successfully expanded and the osteoblastic phenoltypes were confirmed by ALP and Alizarin red staining. The cells could attach and proliferate well on the surface of the β-TCP scaffold. The fluorescent and histological observation showed that the tissue-engineered bone complex had an earlier mineralization and more bone formation inside the scaffold than β-TCP along or even autologous bone. It had also maximally maintained the elevated sinus height than both control groups. Conclusion Porous β-TCP has served as a good scaffold for autologous osteoblasts seeding. The tissue-engineered bone complex with β-TCP and autologous osteoblasts might be a better alternative to autologous bone for the clinical edentulous maxillary sinus augmentation.

  5. Large Aperture Electrostatic Dust Detector

    International Nuclear Information System (INIS)

    Diagnosis and management of dust inventories generated in next-step magnetic fusion devices is necessary for their safe operation. A novel electrostatic dust detector, based on a fine grid of interlocking circuit traces biased to 30 or 50 v has been developed for the detection of dust particles on remote surfaces in air and vacuum environments. Impinging dust particles create a temporary short circuit and the resulting current pulse is recorded by counting electronics. Up to 90% of the particles are ejected from the grid or vaporized suggesting the device may be useful for controlling dust inventories. We report measurements of the sensitivity of a large area (5x5 cm) detector to microgram quantities of dust particles and review its applications to contemporary tokamaks and ITER.

  6. Application of human amniotic mesenchymal cells as an allogeneic transplantation cell source in bone regenerative therapy

    International Nuclear Information System (INIS)

    Autogenous mesenchymal stem cells (MSCs) have therapeutic applications in bone regenerative therapy due to their pluripotency. However, the ability of MSCs to proliferate and differentiate varies between donors. Furthermore, alternative sources of MSCs are required for patients with contraindications to autogenous cell therapy. The aim of this study was to evaluate the potential of mesenchymal cells from the human amniotic membrane (HAM) as a source of cells for allogeneic transplantation in bone regenerative therapy. Cells that retained a proliferative capacity of more than 50 population doubling level were distinguished from other HAM cells as HAMα cells and induced to osteogenic status—their in vivo osteogenesis was subsequently investigated in rats. It was found that HAMα cells were spindle shaped and were positive for MSC markers and negative for hematopoietic stem cell markers. Alkaline phosphatase activity and calcium deposition increased with osteogenic status of HAMα cells. The expression of osteocalcin mRNA was increased in HAMα cells cultured on calcium phosphate scaffolds. Moreover, xenografted HAMα cells remained viable and produced extracellular matrix for several weeks. Thus, this study suggests that human amniotic mesenchymal cells possess osteogenic differentiation potential and could be applied to allogeneic transplantation in bone regenerative therapy. - Highlights: ► Human amniotic mesenchymal cells include cells (HAMα cells) that have the properties of MSCs. ► HAMα cells have excellent osteogenic differentiation potential. ► Osteogenic differentiation ability of HAMα was amplified by calcium phosphate scaffolds. ► HAMα cells can be applicable to allogeneic cell transplantation in bone regenerative therapy.

  7. Application of human amniotic mesenchymal cells as an allogeneic transplantation cell source in bone regenerative therapy

    Energy Technology Data Exchange (ETDEWEB)

    Tsuno, Hiroaki [Department of Regenerative Medicine, Graduate School of Medicine and Pharmaceutical Sciences for Research, University of Toyama, 2630 Sugitani Toyama, Toyama 930-0194 (Japan); Department of Oral and Maxillofacial Surgery, Graduate School of Medicine and Pharmaceutical Sciences for Research, University of Toyama, 2630 Sugitani Toyama, Toyama 930-0194 (Japan); Yoshida, Toshiko [Department of Regenerative Medicine, Graduate School of Medicine and Pharmaceutical Sciences for Research, University of Toyama, 2630 Sugitani Toyama, Toyama 930-0194 (Japan); Nogami, Makiko [Department of Regenerative Medicine, Graduate School of Medicine and Pharmaceutical Sciences for Research, University of Toyama, 2630 Sugitani Toyama, Toyama 930-0194 (Japan); Department of Orthopedic Surgery, Graduate School of Medicine and Pharmaceutical Sciences for Research, University of Toyama, 2630 Sugitani Toyama, Toyama 930-0194 (Japan); Koike, Chika; Okabe, Motonori [Department of Regenerative Medicine, Graduate School of Medicine and Pharmaceutical Sciences for Research, University of Toyama, 2630 Sugitani Toyama, Toyama 930-0194 (Japan); Noto, Zenko [Department of Regenerative Medicine, Graduate School of Medicine and Pharmaceutical Sciences for Research, University of Toyama, 2630 Sugitani Toyama, Toyama 930-0194 (Japan); Department of Oral and Maxillofacial Surgery, Graduate School of Medicine and Pharmaceutical Sciences for Research, University of Toyama, 2630 Sugitani Toyama, Toyama 930-0194 (Japan); Arai, Naoya; Noguchi, Makoto [Department of Oral and Maxillofacial Surgery, Graduate School of Medicine and Pharmaceutical Sciences for Research, University of Toyama, 2630 Sugitani Toyama, Toyama 930-0194 (Japan); Nikaido, Toshio, E-mail: tnikaido@med.u-toyama.ac.jp [Department of Regenerative Medicine, Graduate School of Medicine and Pharmaceutical Sciences for Research, University of Toyama, 2630 Sugitani Toyama, Toyama 930-0194 (Japan)

    2012-12-01

    Autogenous mesenchymal stem cells (MSCs) have therapeutic applications in bone regenerative therapy due to their pluripotency. However, the ability of MSCs to proliferate and differentiate varies between donors. Furthermore, alternative sources of MSCs are required for patients with contraindications to autogenous cell therapy. The aim of this study was to evaluate the potential of mesenchymal cells from the human amniotic membrane (HAM) as a source of cells for allogeneic transplantation in bone regenerative therapy. Cells that retained a proliferative capacity of more than 50 population doubling level were distinguished from other HAM cells as HAM{alpha} cells and induced to osteogenic status-their in vivo osteogenesis was subsequently investigated in rats. It was found that HAM{alpha} cells were spindle shaped and were positive for MSC markers and negative for hematopoietic stem cell markers. Alkaline phosphatase activity and calcium deposition increased with osteogenic status of HAM{alpha} cells. The expression of osteocalcin mRNA was increased in HAM{alpha} cells cultured on calcium phosphate scaffolds. Moreover, xenografted HAM{alpha} cells remained viable and produced extracellular matrix for several weeks. Thus, this study suggests that human amniotic mesenchymal cells possess osteogenic differentiation potential and could be applied to allogeneic transplantation in bone regenerative therapy. - Highlights: Black-Right-Pointing-Pointer Human amniotic mesenchymal cells include cells (HAM{alpha} cells) that have the properties of MSCs. Black-Right-Pointing-Pointer HAM{alpha} cells have excellent osteogenic differentiation potential. Black-Right-Pointing-Pointer Osteogenic differentiation ability of HAM{alpha} was amplified by calcium phosphate scaffolds. Black-Right-Pointing-Pointer HAM{alpha} cells can be applicable to allogeneic cell transplantation in bone regenerative therapy.

  8. Formation of Cosmic Dust Bunnies

    OpenAIRE

    Matthews, Lorin S.; Hayes, Ryan L.; Freed, Michael S.; Hyde, Truell W.

    2007-01-01

    Planetary formation is an efficient process now thought to take place on a relatively short astronomical time scale. Recent observations have shown that the dust surrounding a protostar emits more efficiently at longer wavelengths as the protoplanetary disk evolves, suggesting that the dust particles are coagulating into fluffy aggregates, "much as dust bunnies form under a bed." One poorly understood problem in this coagulation process is the manner in which micron-sized, charged grains form...

  9. Osteoclasts prefer aged bone

    DEFF Research Database (Denmark)

    Henriksen, K; Leeming, Diana Julie; Byrjalsen, I;

    2007-01-01

    We investigated whether the age of the bones endogenously exerts control over the bone resorption ability of the osteoclasts, and found that osteoclasts preferentially develop and resorb bone on aged bone. These findings indicate that the bone matrix itself plays a role in targeted remodeling of...... aged bones....

  10. Dust Heating in Nearby Galaxies

    OpenAIRE

    Kong, Lingjie

    2013-01-01

    Dust is an important part of the interstellar medium (ISM). Dust absorbs ultravioletand optical star light and re-emits in the mid- and far-infrared light. More than onethird of the total star light in the universe is absorbed and re-emitted by dust.Observations show that dust emission is strongly correlated with star formationrates. Recent research with Herschel Space Observatory data has shown that dustemission at ≥ 250 µm appears to be heated by the total stellar population ratherthan just...

  11. Design, synthesis, and initial evaluation of D-glyceraldehyde crosslinked gelatin-hydroxyapatite as a potential bone graft substitute material

    Science.gov (United States)

    Florschutz, Anthony Vatroslav

    Utilization of bone grafts for the treatment of skeletal pathology is a common practice in orthopaedic, craniomaxillofacial, dental, and plastic surgery. Autogenous bone graft is the established archetype but has disadvantages including donor site morbidity, limited supply, and prolonging operative time. In order to avoid these and other issues, bone graft substitute materials are becoming increasingly prevalent among surgeons for reconstructing skeletal defects and arthrodesis applications. Bone graft substitutes are biomaterials, biologics, and guided tissue/bone regenerative devices that can be used alone or in combinations as supplements or alternatives to autogenous bone graft. There is a growing interest and trend to specialize graft substitutes for specific indications and although there is good rationale for this indication-specific approach, the development and utility of a more universal bone graft substitute may provide a better answer for patients and surgeons. The aim of the present research focuses on the design, synthesis, and initial evaluation of D-glyceraldehyde crosslinked gelatin-hydroxyapatite composites for potential use as a bone graft substitutes. After initial establishment of rational material design, gelatinhydroxyapatite scaffolds were fabricated with different gelatin:hydroxyapatite ratios and crosslinking concentrations. The synthesized scaffolds were subsequently evaluated on the basis of their swelling behavior, porosity, density, percent composition, mechanical properties, and morphology and further assessed with respect to cell-biomaterial interaction and biomineralization in vitro. Although none of the materials achieved mechanical properties suitable for structural graft applications, a reproducible material design and synthesis was achieved with properties recognized to facilitate bone formation. Select scaffold formulations as well as a subset of scaffolds loaded with recombinant human bone morphogenetic protein-2 were

  12. Dust coagulation in ISM

    Science.gov (United States)

    Chokshi, Arati; Tielens, Alexander G. G. M.; Hollenbach, David

    1989-01-01

    Coagulation is an important mechanism in the growth of interstellar and interplanetary dust particles. The microphysics of the coagulation process was theoretically analyzed as a function of the physical properties of the coagulating grains, i.e., their size, relative velocities, temperature, elastic properties, and the van der Waal interaction. Numerical calculations of collisions between linear chains provide the wave energy in individual particles and the spectrum of the mechanical vibrations set up in colliding particles. Sticking probabilities are then calculated using simple estimates for elastic deformation energies and for the attenuation of the wave energy due to absorption and scattering processes.

  13. Enxerto autógeno de crista ilíaca na reconstrução do processo alveolar em portadores de fissura labiopalatina: estudo de 30 casos Iliac crest autogenous graft in reconstruction of alveolar process in cleft patients: study of 30 cases

    Directory of Open Access Journals (Sweden)

    João Luiz Carlini

    2000-12-01

    Full Text Available A reconstrução do processo alveolar em pacientes portadores de fissuras labiopalatais (FLP é fundamental para erupção de dentes permanentes e para o restabelecimento estético através de implantes osteointegrados. Assim, considerado o alto grau de reabsorção do enxerto de osso autógeno puro e triturado, optou-se no Centro de Atendimento Integral ao Fissurado Labiopalatino, Curitiba, Paraná (1997 a 1999, pelo estabelecimento de dois grupos de 15 pacientes. No primeiro, foi utilizada crista ilíaca triturada e no outro combinada com hidroxiapatita biorreabsorvível. Ao fim de seis meses, os resultados cirúrgicos foram avaliados através de radiografia periapical digital, determinando quatro linhas limites para a reconstrução óssea. A primeira linha foi traçada na região cervical do dente adjacente à fissura que apresentava menor distorção. As outras linhas foram traçadas paralelamente à linha 1, distando 3mm entre cada uma delas. O espaço entre as linhas 1 e 2 foi denominado de A, entre 2 e 3 de B e 3 e 4 de C. Para critérios de avaliação, quando o enxerto permaneceu no espaço A, foi considerado de sucesso, em contraposição aos espaços B e C, quando foram denominados de procedimentos malsucedidos. Como resultados finais, o espaço A foi constatado em 46,7% dos pacientes submetidos ao procedimento controle com crista ilíaca e 80% para o grupo experimental, quando o enxerto ósseo foi empregado conjuntamente com o material aloplástico (hidroxiapatita.The reconstruction of alveolar process in cleft lip palate patients is mandatory to enable the eruption and movement of permanent teeth through the clefted area by orthodontic procedure, beside the establisment of aesthetics with prostetic procedure by osteointegrated implants. Considering that autogenous bone grafts provide a high reabsortion level determining a reduction of orthodontic movement or making impossible to place implants, to minimize this problem, we

  14. The effects of autogenic-feedback training on motion sickness severity and heart rate variability in astronauts

    Science.gov (United States)

    Toscano, William B.; Cowings, Patricia S.

    1994-01-01

    Space motion sickness (SMS) affects 50 percent of all people during early days of spaceflight. This study describes the results of two Shuttle flight experiments in which autogenic-feedback training (AFT), a physiological conditioning method, was tested as a treatment for this disorder. Of the six who were designated as flight subjects (two women and four men), three were given treatment and three served as controls (i.e., no AFT). Treatment subjects were given 6 hours of preflight AFT. Preflight results showed that AFT produced a significant increase in tolerance to rotating chair motion sickness tests. Further, this increased tolerance was associated with changes in specific physiological responses and reports of reduced malaise. Flight results showed that two of the three control subjects experienced repeated vomiting on the first mission day, while one subject experienced only moderate malaise. Of the three treatment subjects, one experienced mild discomfort, one moderate discomfort, and one severe motion sickness. Only the three control subjects took medication for symptom suppression. Measures of cardiac function reflective of vagal control were shown to be affected especially strongly on the first day of space flight. AFT given for control of heart rate, respiration, and other autonomic activity influenced both the vagal control measures and SMS. These data suggest that AFT may be an effective treatment for space motion sickness; however, this cannot be demonstrated conclusively with the small number of subjects described.

  15. Saliva amylase as a measure of sympathetic change elicited by autogenic training in patients with functional somatic syndromes.

    Science.gov (United States)

    Kiba, Tadashi; Kanbara, Kenji; Ban, Ikumi; Kato, Fumie; Kawashima, Sadanobu; Saka, Yukie; Yamamoto, Kazumi; Nishiyama, Junji; Mizuno, Yasuyuki; Abe, Tetsuya; Fukunaga, Mikihiko

    2015-12-01

    The aim of this study was to discuss the effect of autogenic training (AT) on patients with functional somatic syndrome (FSS) using salivary amylase, the skin temperature of the finger, subjective severity of symptoms, and psychological characteristics as measures. We assessed 20 patients with FSS and 23 healthy controls before and after AT. Baseline levels of salivary amylase prior to an AT session were significantly higher in the FSS group than in the control group. However, this difference was not significant after AT. The skin temperature of the finger increased after AT in both the FSS and control groups. AT contributed to the improvement of somatic symptoms in patients with FSS. Our results regarding psychological characteristics suggest that mood disturbances are deeply involved in the pathology of FSS. Individuals with FSS exhibited elevated levels of sympathetic activity compared with healthy controls. Our data indicates that AT eased dysregulation of the autonomic nervous system in patients with FSS. Thus, salivary amylase may be a useful index of change induced by AT in patients with FSS. PMID:26219656

  16. Autogenous regulation of the EcoRII methylase gene at the transcriptional level: effect of 5-azacytidine.

    Science.gov (United States)

    Som, S; Friedman, S

    1993-01-01

    mRNA of the EcoRII methylase (M.EcoRII), a type II modification enzyme, was induced when Escherichia coli carrying a cloned M.EcoRII gene was exposed to the bacteriocidal drug 5-azacytidine. Induction occurred only when transcription was initiated from its own promoter. When the 5' promoter sequences were deleted or replaced with the lac promoter sequences, no induction occurred. The induction was independent of the template DNA level, but the presence of an intact M.EcoRII protein was a requirement. The drug is incorporated into DNA which then inhibits M.EcoRII by binding tightly to the enzyme. A deletion within the M.EcoRII coding region caused a marked increase in the basal level of mRNA transcribed from the M.EcoRII promoter, but no induction occurred upon 5-azacytidine treatment. The level could be reduced to normal by M.EcoRII in trans. In vitro, the enzyme bound to the sequences upstream of the transcription start sites and inhibited the initiation of transcription. These experiments indicate that expression of the M.EcoRII gene was autogenously regulated at the transcriptional level. Similar regulation is also noted in another DNA (cytosine-5) methylase, M.MspI. Images PMID:7693455

  17. Effect of autogenic training on general improvement in patients with irritable bowel syndrome: a randomized controlled trial.

    Science.gov (United States)

    Shinozaki, Masae; Kanazawa, Motoyori; Kano, Michiko; Endo, Yuka; Nakaya, Naoki; Hongo, Michio; Fukudo, Shin

    2010-09-01

    Autogenic training (AT) is a useful and comprehensive relaxation technique. However, no studies have investigated the effects of AT on irritable bowel syndrome (IBS). In this study we tested the hypothesis that AT improves symptoms of IBS. Twenty-one patients with IBS were randomly assigned to AT (n = 11, 5 male, 6 female) or control therapy (n = 10, 5 male, 5 female). AT patients were trained intensively, while the control therapy consisted of discussions about patients' meal habits and life styles. All patients answered a question related to adequate relief (AR) of IBS symptoms and four questionnaires: Self-induced IBS Questionnaire (SIBSQ), Self-reported Depression Scale (SDS), State-Trait Anxiety Inventory (STAI), and Medical Outcome Short Form 36 Health Survey (SF-36). The proportion of AR in the last AT session in the AT group (9/11, 81.8%) was significantly higher than that in the controls (3/10, 30.0%, Chi-square test, p = 0.048). Two subscales of the SF-36, i.e., social functioning and bodily pain, were significantly improved in the AT group (p < 0.05) as compared to the control group. Role emotional (p = 0.051) and general health (p = 0.068) showed a tendency for improvement in the AT group. AT may be useful in the treatment of IBS by enhancing self-control. PMID:19997775

  18. Hazards of explosives dusts: Particle size effects

    Energy Technology Data Exchange (ETDEWEB)

    Cashdollar, K L; Hertzberg, M; Green, G M

    1992-02-01

    At the request of the Department of Energy, the Bureau of Mines has investigated the hazards of military explosives dispersed as dust clouds in a 20-L test chamber. In this report, the effect of particle size for HMX, HNS, RDX, TATB, and TNT explosives dusts is studied in detail. The explosibility data for these dusts are also compared to those for pure fuel dusts. The data show that all of the sizes of the explosives dusts that were studied were capable of sustaining explosions as dust clouds dispersed in air. The finest sizes (<10 [mu]m) of explosives dusts were less reactive than the intermediate sizes (20 to 60 [mu]m); this is opposite to the particle size effect observed previously for the pure fuel dusts. At the largest sizes studied, the explosives dusts become somewhat less reactive as dispersed dust clouds. The six sizes of the HMX dust were also studied as dust clouds dispersed in nitrogen.

  19. Charged Dust Aggregate Interactions

    Science.gov (United States)

    Matthews, Lorin; Hyde, Truell

    2015-11-01

    A proper understanding of the behavior of dust particle aggregates immersed in a complex plasma first requires a knowledge of the basic properties of the system. Among the most important of these are the net electrostatic charge and higher multipole moments on the dust aggregate as well as the manner in which the aggregate interacts with the local electrostatic fields. The formation of elongated, fractal-like aggregates levitating in the sheath electric field of a weakly ionized RF generated plasma discharge has recently been observed experimentally. The resulting data has shown that as aggregates approach one another, they can both accelerate and rotate. At equilibrium, aggregates are observed to levitate with regular spacing, rotating about their long axis aligned parallel to the sheath electric field. Since gas drag tends to slow any such rotation, energy must be constantly fed into the system in order to sustain it. A numerical model designed to analyze this motion provides both the electrostatic charge and higher multipole moments of the aggregate while including the forces due to thermophoresis, neutral gas drag, and the ion wakefield. This model will be used to investigate the ambient conditions leading to the observed interactions. This research is funded by NSF Grant 1414523.

  20. Of data and dust

    CERN Multimedia

    Stephanie Hills

    2016-01-01

    The traditional image of an archive is one of dusty old boxes, books and papers. When your archive is digital, dust spells disaster. An innovative environmental sensor designed and built by a CERN IT specialist has become an essential element in the Laboratory’s data-preservation strategy.   The novel air particle monitoring sensor designed by CERN's Julien Leduc. CERN’s archive holds more than 130 petabytes of data from past and present high-energy physics experiments. Some of it is 40 years old, most of it needs to be kept forever, and all of it is held on tape cartridges (over 20,000 of them). The cartridges are held inside tape libraries with robotic arms that load them into tape drives where they can be read and written. Tape cartridges have many advantages over other data storage media, notably cost and long-term reliability, but topping the list of drawbacks is their vulnerability to contamination from airborne dust particles; a tiny piece of g...

  1. Radionuclides in house dust

    International Nuclear Information System (INIS)

    Discharges of radionuclides from the British Nuclear Fuel plc (BNFL) reprocessing plant at Sellafield in Cumbria have led to elevated concentrations radionuclides in the local environment. The major routes of exposure of the public are kept under review by the appropriate authorising Government departments and monitoring is carried out both by the departments and by BNFL itself. Recently, there has been increasing public concern about general environmental contamination resulting from the discharges and, in particular, about possible exposure of members of the public by routes not previously investigated in detail. One such postulated route of exposure that has attracted the interest of the public, the press and Parliament arises from the presence of radionuclides within houses. In view of this obvious and widespread concern, the Board has undertaken a sampling programme in a few communities in Cumbria to assess the radiological significance of this source of exposure. From the results of our study, we conclude that, although radionuclides originating rom the BNFL site can be detected in house dust, this source of contamination is a negligible route of exposure for members of the public in West Cumbria. This report presents the results of the Board's study of house dust in twenty homes in Cumbria during the spring and summer of 1984. A more intensive investigation is being carried out by Imperial College. (author)

  2. 75 FR 32142 - Combustible Dust

    Science.gov (United States)

    2010-06-07

    ... combustible dust in the workplace. (74 FR 54334, Oct. 21, 2009). OSHA plans to use the information received in... Secretary's Order 5-2007 (72 FR 31160). Signed at Washington, DC, on June 1, 2010. David Michaels, Assistant... Occupational Safety and Health Administration 29 CFR Part 1910 RIN 1218-AC41 Combustible Dust...

  3. 75 FR 10739 - Combustible Dust

    Science.gov (United States)

    2010-03-09

    ... for combustible dust. (74 FR 54334, Oct. 21, 2009) II. Stakeholder Meetings OSHA conducted two... (72 FR 31160). Signed at Washington, DC, on March 2, 2010. David Michaels, Assistant Secretary of... Occupational Safety and Health Administration 29 CFR Part 1910 RIN 1218-AC41 Combustible Dust...

  4. Dust particle charging in sheath

    International Nuclear Information System (INIS)

    The charging and the screening of spherical dust particles in sheaths near the wall were studied using computer simulation. The three-dimensional PIC/MCC method and molecular dynamics method were applied to describe plasma particles motion and interaction with macroscopic dust grain. Calculations were carried out at different neutral gas pressures and wall potentials. Values of the charge of the dust particles and spatial distributions of plasma parameters are obtained by modelling. The results have shown that the charge of the dust particles in the sheath, as well as the spatial distribution of the ions and electrons near the dust particles, depend strongly on the wall potential. It is shown that for large negative values of the wall potential the negative charge of a dust particle decreases due to the decline of the electron density in its vicinity. In addition, the flow of energy of the ions on the surface of dust particles is increased due to better focusing effect of the dust particle field on ions.

  5. Dust and the Sick Building Syndrome

    DEFF Research Database (Denmark)

    Gyntelberg, Finn; Suadicani, Poul; Wohlfahrt Nielsen, Jan; Skov, Peder; Valbjørn, Ole; Nielsen, Peter A.; Schneider, Thomas; Jørgensen, Ole; Wolkoff, Peder; Wilkins, C. K.; Gravesen, Suzanne; Norn, Svend

    Farmakologi, bacteria, dust, histamine, disease, gram-negative, indoor climate, sick building syndrome......Farmakologi, bacteria, dust, histamine, disease, gram-negative, indoor climate, sick building syndrome...

  6. Bi-dust acoustic waves

    Energy Technology Data Exchange (ETDEWEB)

    Martin, P.; Castro, E.; Puerta, J. [Universidad Simon Bolivar, Apartado 89000, Caracas 1080A (Venezuela); Valdeblanquez, E. [Universidad del Zulia, facultad de Ingenieria, Apartado 4011-A 526, Maracaibo, Edo. Zulia (Venezuela)

    2006-07-01

    Low frequencies waves in plasmas with two kind of dusty grains have been studied. Each species of dust particle is characterized by the grain radius, which determines its equilibrium charge. Relative velocities between the two kinds of dust grain for the unperturbed plasma is also considered in order to study instabilities and compare with astrophysical and industrial applications. In this analysis, each dust species is handled with a simplified model of kinetic-fluid equations, and the electrons and ions are determined by Boltzmann factors. The low frequency dispersion relation for bi-dust plasma waves with non relative motion between each kind of grain leads to damped waves with two characteristic frequencies. Instabilities are produced by the relative motion between the species. The onset of these instabilities is studied as a function of the plasma dust frequencies and relative velocities among each species. (Author)

  7. Evaluation of the osteogenesis and angiogenesis effects of erythropoietin and the efficacy of deproteinized bovine bone/recombinant human erythropoietin scaffold on bone defect repair.

    Science.gov (United States)

    Li, Donghai; Deng, Liqing; Xie, Xiaowei; Yang, Zhouyuan; Kang, Pengde

    2016-06-01

    Erythropoietin (EPO) could promote the angiogenesis and may also play a role in bone regeneration. This study was conducted to evaluate the osteogenesis and angiogenesis effects of EPO and the efficacy of deproteinized bovine bone/recombinant human EPO scaffold on bone defect repair. Twenty-four healthy adult goats were chosen to build goat defects model and randomly divided into four groups. The goats were treated with DBB/rhEPO scaffolds (group A), porous DBB scaffolds (group B), autogenous cancellous bone graft (group C), and nothing (group D). Animals were evaluated with radiological and histological methods at 4, 8 and 12 weeks after surgery. The grey value of radiographs was used to evaluate the healing of the defects and the outcome revealed that the group A had a better outcome of defect healing compared with group B (P  0.05). The newly formed bone area was calculated from histological sections and the results demonstrated that the amount of new bone in group A increased significantly compared with that in group B (P  0.05) at 4, 8, 12 weeks respectively. In addition, the expression of vascular endothelial growth factor (VEGF) by immunohistochemical testing and real-time polymerase chain reaction at 12 weeks in group A was significantly higher than that in group B (P  0.05). Therefore, EPO has significant effects on bone formation and angiogenesis, and has capacity to promote the repair of bone defects. It is worthy of being recommended to further studies. PMID:27091043

  8. Dust in protoplanetary disks: observations*

    Directory of Open Access Journals (Sweden)

    Waters L.B.F.M.

    2015-01-01

    Full Text Available Solid particles, usually referred to as dust, are a crucial component of interstellar matter and of planet forming disks surrounding young stars. Despite the relatively small mass fraction of ≈1% (in the solar neighborhood of our galaxy; this number may differ substantially in other galaxies that interstellar grains represent of the total mass budget of interstellar matter, dust grains play an important role in the physics and chemistry of interstellar matter. This is because of the opacity dust grains at short (optical, UV wavelengths, and the surface they provide for chemical reactions. In addition, dust grains play a pivotal role in the planet formation process: in the core accretion model of planet formation, the growth of dust grains from the microscopic size range to large, cm-sized or larger grains is the first step in planet formation. Not only the grain size distribution is affected by planet formation. Chemical and physical processes alter the structure and chemical composition of dust grains as they enter the protoplanetary disk and move closer to the forming star. Therefore, a lot can be learned about the way stars and planets are formed by observations of dust in protoplanetary disks. Ideally, one would like to measure the dust mass, the grain size distribution, grain structure (porosity, fluffiness, the chemical composition, and all of these as a function of position in the disk. Fortunately, several observational diagnostics are available to derive constrains on these quantities. In combination with rapidly increasing quality of the data (spatial and spectral resolution, a lot of progress has been made in our understanding of dust evolution in protoplanetary disks. An excellent review of dust evolution in protoplanetary disks can be found in Testi et al. (2014.

  9. Dust in protoplanetary disks: observations

    Science.gov (United States)

    Waters, L. B. F. M.

    2015-09-01

    Solid particles, usually referred to as dust, are a crucial component of interstellar matter and of planet forming disks surrounding young stars. Despite the relatively small mass fraction of ≈1% (in the solar neighborhood of our galaxy; this number may differ substantially in other galaxies) that interstellar grains represent of the total mass budget of interstellar matter, dust grains play an important role in the physics and chemistry of interstellar matter. This is because of the opacity dust grains at short (optical, UV) wavelengths, and the surface they provide for chemical reactions. In addition, dust grains play a pivotal role in the planet formation process: in the core accretion model of planet formation, the growth of dust grains from the microscopic size range to large, cm-sized or larger grains is the first step in planet formation. Not only the grain size distribution is affected by planet formation. Chemical and physical processes alter the structure and chemical composition of dust grains as they enter the protoplanetary disk and move closer to the forming star. Therefore, a lot can be learned about the way stars and planets are formed by observations of dust in protoplanetary disks. Ideally, one would like to measure the dust mass, the grain size distribution, grain structure (porosity, fluffiness), the chemical composition, and all of these as a function of position in the disk. Fortunately, several observational diagnostics are available to derive constrains on these quantities. In combination with rapidly increasing quality of the data (spatial and spectral resolution), a lot of progress has been made in our understanding of dust evolution in protoplanetary disks. An excellent review of dust evolution in protoplanetary disks can be found in Testi et al. (2014). 2nd Lecture of the Summer School "Protoplanetary Disks: Theory and Modelling Meet Observations"

  10. The Use of Platelet Rich Plasma, Bone Morphogenetic Protein-2 and Different Scaffolds in Oral and Maxillofacial Surgery - Literature Review in Comparison with Own Clinical Experience

    Directory of Open Access Journals (Sweden)

    Karl-Heinz Schuckert

    2011-01-01

    Full Text Available Objectives: The purpose of this article was to review and critically assess the use of platelet rich plasma, recombinant human bone morphogenetic protein-2 and different scaffolds (i.e. tricalciumphosphate, polycaprolactone, demineralized bone matrix and anorganic bovine bone mineral in oral and maxillofacial surgery comparing the relevant literature and own clinical experience.Material and Methods: A literature review was conducted using MEDLINE, MEDPILOT and COCHRANE DATABASE OF SYSTEMATIC REVIEWS. It concentrated on manuscripts and overviews published in the last five years (2006-2010. The key terms employed were platelet rich plasma, bone morphogenetic proteins and their combinations with the above mentioned scaffolds. The results of clinical studies and animal trials were especially emphasized. The statements from the literature were compared with authors’ own clinical data.Results: New publications and overviews demonstrate the advantages of platelet rich plasma in bone regeneration. The results from the literature review were discussed and compared with the publications detailing authors’ own experiences.Conclusions: A favourable outcome concerning newly grown bone was achieved combining platelet rich plasma in addition to optimal matrices with or without recombinant human bone morphogenetic protein-2, depending on the clinical case. As a consequence, the paradigm shift from transplantation of autogenous bone to bone tissue engineering appears promising.

  11. Bone-Forming Capabilities of a Newly Developed NanoHA Composite Alloplast Infused with Collagen: A Pilot Study in the Sheep Mandible

    Directory of Open Access Journals (Sweden)

    Charles Marin

    2013-01-01

    Full Text Available Lateral or vertical bone augmentation has always been a challenge, since the site is exposed to constant pressure from the soft tissue, and blood supply only exists from the donor site. Although, for such clinical cases, onlay grafting with autogenous bone is commonly selected, the invasiveness of the secondary surgical site and the relatively fast resorption rate have been reported as a drawback, which motivated the investigation of alternative approaches. This study evaluated the bone-forming capability of a novel nanoHA alloplast infused with collagen graft material made from biodegradable polylactic acid/polyglycolic acid versus a control graft material with the same synthesized alloplast without the nanoHA component and collagen infiltration. The status of newly formed bone and the resorption of the graft material were evaluated at 6 weeks in vivo histologically and three dimensionally by means of 3D microcomputed tomography. The histologic observation showed that newly formed bone ingrowth and internal resorption of the block were observed for the experimental blocks, whereas for the control blocks less bone ingrowth occurred along with lower resorption rate of the block material. The three-dimensional observation indicated that the experimental block maintained the external geometry, but at the same time successfully altered the graft material into bone. It is suggested that the combination of numerous factors contributed to the bone ingrowth and the novel development could be an alternative bone grafting choice.

  12. Coralline hydroxyapatite bone graft substitutes in a canine diaphyseal defect model: Radiographic features of failed and successful union

    International Nuclear Information System (INIS)

    Radiographic and densitometric evaluation of a new type of bone graft substitute derived from reef-building sea coral via a hydrothermal chemical exchange process was undertaken in a canine diaphyseal defect model. Comparably sized blocks of this material and autogenous iliac cortical-cancellous graft were implanted into the respective radial diaphyses of seven dogs. Qualitative and quantitative radiographic assessment was performed during the immediate postoperative period and at 3 months following surgery. Significant complications were observed radiographically in over half of the coralline implanted limbs, including failed union, graft fracture, and loosening of internal fixation hardware. No significant difference was noted in degree of native osseous ingrowth between the implants and the autografts, and the latter exhibited a higher success rate. Radiographic film densitometry was found not to be reliably predictive of coralline implant behavior in the individual case. It is concluded that coralline hydroxyapatite bone graft substitutes appear to offer no particular advantage over autogenous grafts in the management of diaphyseal defects, although further investigation is warranted since other factors may be responsible for the unfavorable findings in this study. (orig.)

  13. The Martian Dust Cycle: Observations and Modeling

    Science.gov (United States)

    Kahre, Melinda A.

    2013-01-01

    The dust cycle is critically important for Mars' current climate system. Suspended atmospheric dust affects the radiative balance of the atmosphere, and thus greatly influences the thermal and dynamical state of the atmosphere. Evidence for the presence of dust in the Martian atmosphere can be traced back to yellow clouds telescopically observed as early as the early 19th century. The Mariner 9 orbiter arrived at Mars in November of 1971 to find a planet completely enshrouded in airborne dust. Since that time, the exchange of dust between the planet's surface and atmosphere and the role of airborne dust on Mars' weather and climate has been studied using observations and numerical models. The goal of this talk is to give an overview of the observations and to discuss the successes and challenges associated with modeling the dust cycle. Dust raising events on Mars range in size from meters to hundreds of kilometers. During some years, regional storms merge to produce hemispheric or planet encircling dust clouds that obscure the surface and raise atmospheric temperatures by tens of kelvin. The interannual variability of planet encircling dust storms is poorly understood. Although the occurrence and season of large regional and global dust storms are highly variable from one year to the next, there are many features of the dust cycle that occur year after year. A low-level dust haze is maintained during northern spring and summer, while elevated levels of atmospheric dust occur during northern autumn and winter. During years without global-scale dust storms, two peaks in total dust loading are generally observed: one peak occurs before northern winter solstice and one peak occurs after northern winter solstice. Numerical modeling studies attempting to interactively simulate the Martian dust cycle with general circulation models (GCMs) include the lifting, transport, and sedimentation of radiatively active dust. Two dust lifting processes are commonly represented in

  14. Dust jets produced by a dust-discharge instability

    International Nuclear Information System (INIS)

    We report observations of an instability that occurs in a dc glow discharge (anodic plasma) dusty plasma when a floating plate with a 5 mm aperture is placed in front of the anode. The instability is characterized by periodic quenching and reignition of the discharge. When the discharge is quenched, the dust is ejected from the aperture at speeds on the order of the dust-acoustic speed. The ejected dust remains partially charged and retracts back to the aperture when the discharge spontaneously redevelops.

  15. Regular spherical dust spacetimes

    CERN Document Server

    Humphreys, N; Matravers, D R; Humphreys, Neil; Maartens, Roy; Matravers, David

    1998-01-01

    Physical (and weak) regularity conditions are used to determine and classify all the possible types of spherically symmetric dust spacetimes in general relativity. This work unifies and completes various earlier results. The junction conditions are described for general non-comoving (and non-null) surfaces, and the limits of kinematical quantities are given on all comoving surfaces where there is Darmois matching. We show that an inhomogeneous generalisation of the Kantowski-Sachs metric may be joined to the Lemaitre-Tolman-Bondi metric. All the possible spacetimes are explicitly divided into four groups according to topology, including a group in which the spatial sections have the topology of a 3-torus. The recollapse conjecture (for these spacetimes) follows naturally in this approach.

  16. Dust ablation in Pluto's atmosphere

    Science.gov (United States)

    Horanyi, Mihaly; Poppe, Andrew; Sternovsky, Zoltan

    2016-04-01

    Based on measurements by dust detectors onboard the Pioneer 10/11 and New Horizons spacecraft the total production rate of dust particles born in the Edgeworth Kuiper Belt (EKB) has been be estimated to be on the order of 5 ṡ 103 kg/s in the approximate size range of 1 - 10 μm. Dust particles are produced by collisions between EKB objects and their bombardment by both interplanetary and interstellar dust particles. Dust particles of EKB origin, in general, migrate towards the Sun due to Poynting-Robertson drag but their distributions are further sculpted by mean-motion resonances as they first approach the orbit of Neptune and later the other planets, as well as mutual collisions. Subsequently, Jupiter will eject the vast majority of them before they reach the inner solar system. The expected mass influx into Pluto atmosphere is on the order of 200 kg/day, and the arrival speed of the incoming particles is on the order of 3 - 4 km/s. We have followed the ablation history as function of speed and size of dust particles in Pluto's atmosphere, and found that volatile rich particles can fully sublimate due to drag heating and deposit their mass in narrow layers. This deposition might promote the formation of the haze layers observed by the New Horizons spacecraft. This talk will explore the constraints on the composition of the dust particles by comparing the altitude of the deposition layers to the observed haze layers.

  17. Nonlinear theory of dust lattice mode coupling in dust crystals

    CERN Document Server

    Kourakis, I; Kourakis, Ioannis; Shukla, Padma Kant

    2004-01-01

    Quasi-crystals formed by charged mesoscopic dust grains (dust lattices), observed since hardly a decade ago, are an exciting paradigm of a nonlinear chain. In laboratory discharge experiments, these quasi-lattices are formed spontaneously in the sheath region near a negative electrode, usually at a levitated horizontal equilibrium configuration where gravity is balanced by an electric field. It is long known (and experimentally confirmed) that dust-lattices support linear oscillations, in the longitudinal (acoustic mode) as well as in the transverse, in plane (acoustic-) or off-plane (optic-like mode) directions. Either due to the (typically Yukawa type) electrostatic inter-grain interaction forces or to the (intrinsically nonlinear) sheath environment, nonlinearity is expected to play an important role in the dynamics of these lattices. Furthermore, the coupling between the different modes may induce coupled nonlinear modes. Despite this evidence, the elucidation of the nonlinear mechanisms governing dust cr...

  18. Dust Storm Events in Iceland: Physical Properties of Icelandic Dust

    Czech Academy of Sciences Publication Activity Database

    Dagsson-Waldhauserova, P.; Arnalds, O.; Olafsson, H.; Škrabalová, L.; Sigurdardottir, G. M.; Braniš, M.; Hladil, Jindřich; Skála, Roman; Navrátil, Tomáš; Chadimová, Leona; von Lowis of Menar, S.; Thorsteinsson, T.

    s. l : s. n, 2013. [International Workshop on Sand /Duststorms and Associated Dustfall /7./. 02.12.2013-04.12.2013, Rome] Institutional support: RVO:67985831 Keywords : dust * geology * geochemistry Subject RIV: DB - Geology ; Mineralogy

  19. Triton's streaks as windblown dust

    Science.gov (United States)

    Sagan, Carl; Chyba, Christopher

    1990-01-01

    Explanations for the surface streaks observed by Voyager 2 on Triton's southern hemisphere are discussed. It is shown that, despite Triton's tenuous atmosphere, low-cohesion dust trains with diameters of about 5 micron or less may be carried into suspension by aeolian surface shear stress, given expected geostrophic wind speeds of about 10 m/s. For geyser-like erupting dust plumes, it is shown that dust-settling time scales and expected wind velocities can produce streaks with length scales in good agreement with those of the streaks. Thus, both geyserlike eruptions or direct lifting by surface winds appear to be viable mechanisms for the origin of the streaks.

  20. Bone marrow biopsy

    Science.gov (United States)

    Biopsy - bone marrow ... A bone marrow biopsy may be done in the health care provider's office or in a hospital. The sample may be taken from the pelvic or breast bone. Sometimes, other areas are used. Marrow is removed ...

  1. Bone marrow aspiration

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003658.htm Bone marrow aspiration To use the sharing features on this page, please enable JavaScript. Bone marrow is the soft tissue inside bones that helps ...

  2. The Sky in Dust -- Methods and Prospects of Dust Astronomy

    CERN Document Server

    Landgraf, M; Srama, R; Helfert, S; Kempf, S; Morgas-Klostermeyer, G; Rachev, M; Srowig, A; Auer, S; Hor`anyi, M; Sternovsky, Z; Harris, D

    2006-01-01

    Information about the make-up of the galaxy arrives in the Solar system in many forms: photons of different energies, classically collected by ground- and space-based telescopes, neutral and charged atomic particles, and solid macroscopic particles: cosmic dust particles. Dust particles, like photons, carry information from remote sites in space and time. This information can be analysed in order to understand the processes and mechanisms that are involved in the formation and evolution of solid matter in the galaxy. This approach is called ``Dust Astronomy'' which is carried out by means of a dust telescope on a dust observatory in space. The analysis of cosmic grains collected in the high atmosphere of the Earth has shown that each dust grain is a small world with various sub-grains featuring different galactic origin and evolution, which is identified on the basis of elementary and isotopic analysis. Independent information about the origin and evolution of the grains coming from the kinematic properties o...

  3. PERSPECTIVE: Dust, fertilization and sources

    Science.gov (United States)

    Remer, Lorraine A.

    2006-11-01

    Aerosols, tiny suspended particles in the atmosphere, play an important role in modifying the Earth's energy balance and are essential for the formation of cloud droplets. Suspended dust particles lifted from the world's arid regions by strong winds contain essential minerals that can be transported great distances and deposited into the ocean or on other continents where productivity is limited by lack of usable minerals [1]. Dust can transport pathogens as well as minerals great distance, contributing to the spread of human and agricultural diseases, and a portion of dust can be attributed to human activity suggesting that dust radiative effects should be included in estimates of anthropogenic climate forcing. The greenish and brownish tints in figure 1 show the wide extent of monthly mean mineral dust transport, as viewed by the MODerate resolution Imaging Spectroradiometer (MODIS) satellite sensor. The monthly mean global aerosol system for February 2006 from the MODIS aboard the Terra satellite Figure 1. The monthly mean global aerosol system for February 2006 from the MODIS aboard the Terra satellite. The brighter the color, the greater the aerosol loading. Red and reddish tints indicate aerosol dominated by small particles created primarily from combustion processes. Green and brownish tints indicate larger particles created from wind-driven processes, usually transported desert dust. Note the bright green band at the southern edge of the Saharan desert, the reddish band it must cross if transported to the southwest and the long brownish transport path as it crosses the Atlantic to South America. Image courtesy of the NASA Earth Observatory (http://earthobservatory.nasa.gov). Even though qualitatively we recognize the extent and importance of dust transport and the role that it plays in fertilizing nutrient-limited regions, there is much that is still unknown. We are just now beginning to quantify the amount of dust that exits one continental region and the

  4. Rehabilitation of Avulsed Teeth in Fractured Jaws via Bone Grafting and Implant Placement: Report of Two Cases.

    Science.gov (United States)

    Jain, Anshul; Baliga, Shridhar

    2015-07-01

    The maxillofacial region is one of the most injury-prone areas during road traffic accidents, personal violence, falls and sports. Maxillofacial trauma can lead to breakage or avulsion of upper anterior teeth, which may cause significant aesthetic and functional problems. There are many treatment options available for rehabilitation including removable partial dentures, fixed partial dentures, crown and bridges and implant-supported prostheses. Herein, two cases are presented where implant placement was done for upper anterior teeth, which were traumatized or avulsed following maxillofacial trauma. Both patients demonstrated a history of maxillofacial trauma and had undergone open reduction and internal fixation. The first patient had a severe maxillary alveolar defect treated via autogenous bone grafting and a six-month period was given for proper integration of the bone graft. The second patient was a smoker with very poor oral hygiene and a deep bite. Thus, implant placement was not initially justified. PMID:26877745

  5. Rehabilitation of Avulsed Teeth in Fractured Jaws via Bone Grafting and Implant Placement: Report of Two Cases

    Directory of Open Access Journals (Sweden)

    Anshul Jain

    2016-01-01

    Full Text Available The maxillofacial region is one of the most injury-prone areas during road traffic accidents, personal violence, falls and sports. Maxillofacial trauma can lead to breakage or avulsion of upper anterior teeth, which may cause significant aesthetic and functional problems. There are many treatment options available for rehabilitation including removable partial dentures, fixed partial dentures, crown and bridges and implant-supported prostheses.Herein, two cases are presented where implant placement was done for upper anterior teeth, which were traumatized or avulsed following maxillofacial trauma. Both patients demonstrated a history of maxillofacial trauma and had undergone open reduction and internal fixation. The first patient had a severe maxillary alveolar defect treated via autogenous bone grafting and a six-month period was given for proper integration of the bone graft. The second patient was a smoker with very poor oral hygiene and a deep bite. Thus, implant placement was not initially justified.

  6. Brånemark and ITI dental implants in the human bone-grafted maxilla: a comparative evaluation

    DEFF Research Database (Denmark)

    Pinholt, Else M

    2003-01-01

    either Brånemark- or ITI-fixures. In 25 patients (18 females, seven males) the severely atrophied maxilla was reconstructed with autogenous iliac or mandibular bone and either Brånemark or ITI implants. Seventy-eight Brånemark implants and 80 SLA-ITI implants were inserted in the augmented bone....... Twelve consecutive patients received machine-surfaced Brånemark fixtures and 13 consecutive patients received SLA-ITI fixtures. Gradual loading was applied after healing abutment application. After 6 months the permanent prosthetic reconstruction was provided to the patient, either as a fixed...... or removable bridge. Comparison in survival rate was performed: 15 machined Brånemark fixtures were lost, resulting in an overall survival rate of 81%. Two ITI fixtures were lost, resulting in an overall survival rate of 98%. The results of this evaluation show that sandblasted large grit acid etched surface...

  7. Anorexia Nervosa and Bone

    OpenAIRE

    Misra, Madhusmita; Klibanski, Anne

    2014-01-01

    Anorexia nervosa (AN) is a condition of severe low weight that is associated with low bone mass, impaired bone structure and reduced bone strength, all of which contribute to increased fracture risk., Adolescents with AN have decreased rates of bone accrual compared with normal-weight controls, raising addition concerns of suboptimal peak bone mass and future bone health in this age group. Changes in lean mass and compartmental fat depots, hormonal alterations secondary to nutritional factors...

  8. Twisted Dust Acoustic Waves in Dusty Plasmas

    CERN Document Server

    Shukla, P K

    2012-01-01

    We examine linear dust acoustic waves (DAWs) in a dusty plasma with strongly correlated dust grains, and discuss possibility of a twisted DA vortex beam carrying orbital angular momentum (OAM). For our purposes, we use the Boltzmann distributed electron and ion density perturbations, the dust continuity and generalized viscoelastic dust momentum equations, and Poisson's equation to obtain a dispersion relation for the modified DAWs. The effects of the polarization force, strong dust couplings, and dust charge fluctuations on the DAW spectrum are examined. Furthermore, we demonstrate that the DAW can propagate as a twisted vortex beam carrying OAM. A twisted DA vortex structure can trap and transport dust particles in dusty plasmas.

  9. Metals and dust in high redshift AGNs

    CERN Document Server

    Maiolino, R; Marconi, A; Schneider, R; Bianchi, S; Pedani, M; Pipino, A; Matteucci, F; Cox, P; Caselli, P

    2006-01-01

    We summarize some recent results on the metallicity and dust properties of Active Galactic Nuclei (AGN) at high redshift (110). The properties of dust in high-z QSOs are discussed within the context of the dust production mechanisms in the early universe. The dust extinction curve is observed to evolve beyond z>4, and by z~6 it is well described by the properties expected for dust produced by SNe, suggesting that the latter is the main mechanism of dust production in the early universe. We also show that the huge dust masses observed in distant QSOs can be accounted for by SN dust within the observational constraints currently available. Finally, we show that QSO winds, which have been proposed as an alternative mechanism of dust production, may also contribute significantly to the total dust budget at high redshift.

  10. Implant surface preparation in the surgical treatment of experimental peri-implantitis with autogenous bone graft and ePTFE membrane in cynomolgus monkeys

    DEFF Research Database (Denmark)

    Schou, Søren; Holmstrup, Palle; Jørgensen, Torben;

    2003-01-01

    peri-implantitis; treatment; implant surface preparation; nonhuman primates; histology; stereology......peri-implantitis; treatment; implant surface preparation; nonhuman primates; histology; stereology...

  11. Maxillary sinus floor augmentation with Bio-Oss or Bio-Oss mixed with autogenous bone as graft: a systematic review

    DEFF Research Database (Denmark)

    Jensen, Thomas; Schou, Søren; Stavropoulos, Andreas; Terheyden, Hendrik; Holmstrup, Palle

    2012-01-01

    and methods: A MEDLINE (PubMed) search in combination with a hand search of relevant journals was conducted by including human studies published in English from January 1, 1990 to June 1, 2010. The search provided 879 titles and 35 studies fulfilled the inclusion criteria. Considerable variation in...

  12. Prevention of bone bridge formation using transplantation of the autogenous mesenchymal stem cells to physeal defects: An experimental study in rabbits

    Czech Academy of Sciences Publication Activity Database

    Plánka, L.; Nečas, A.; Gál, P.; Kecová, H.; Filová, Eva; Křen, L.; Kroupa, P.

    2007-01-01

    Roč. 76, - (2007), s. 253-263. ISSN 0001-7213 R&D Projects: GA MŠk 2B06130 Institutional research plan: CEZ:AV0Z50390512 Keywords : Growth plate injury * Physis * Growth arrest Subject RIV: FI - Traumatology, Orthopedics Impact factor: 0.687, year: 2007

  13. Loess and Eolian Dust Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Records of past environment derived from Loess and Eolian dust (silt-sized material deposited on the Earth surface by the surface winds. Parameter keywords describe...

  14. Surface System Dust Mitigation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed effort will perform a detailed examination of dust mitigation and tolerance strategies for connections and mechanisms to be employed on the lunar...

  15. Infrared astronony and galactic dust

    International Nuclear Information System (INIS)

    A review of infrared sources of cosmic radiation - interstellar dust clouds, cocoon stars, novae, and gas supergiants - is presented. The possibilities of exact estimation of the star and galaxy brightness are considered. The difficulties of experiments and the reasons for choosing the infrared range for observations (teh maximum radiation of cold dust particles and the high transparency of the dust clouds) are noted. A Galaxy centre strongly radiating in the infrared range and situated in the Sagittarius constellation is considered as an example, and its schematic picture is given. A rough estimate of the absorption by stellar structures, dust and gas clouds is given. The diagram of the Main sequence of infrared sources and the dependence of their luminosity on the effective temperature are presented. The energy distribution in the spectrum of a complex object at different temperatures and wave lengths is considered. The frequency dependence of the radiation flux for the objects of the Orion constellation is given

  16. Dust in protoplanetary disks: observations*

    OpenAIRE

    Waters L.B.F.M.

    2015-01-01

    Solid particles, usually referred to as dust, are a crucial component of interstellar matter and of planet forming disks surrounding young stars. Despite the relatively small mass fraction of ≈1% (in the solar neighborhood of our galaxy; this number may differ substantially in other galaxies) that interstellar grains represent of the total mass budget of interstellar matter, dust grains play an important role in the physics and chemistry of interstellar matter. This is because of the opacity ...

  17. Saharan Dust Pollution: Implications for the Sahel?

    OpenAIRE

    De Longueville, Florence; Henry, Sabine; Ozer, Pierre

    2009-01-01

    The main source of atmospheric mineral dust is the Sahara desert, which produces about half of the yearly global mineral dust.1 About 12% of the Saharan dust moves northwards to Europe, 28% westwards to the Americas, and 60% southwards to the Gulf of Guinea. Saharan dust storms can lead to particulate matter (PM) levels that exceed internationally recommended levels. Recently, special attention has been paid to the mineral PM air pollution of dust storms, which may be a serious health threat....

  18. Bone strength: more than just bone density.

    Science.gov (United States)

    Ott, Susan M

    2016-01-01

    The following bone density measurements have limited utility in determining bone strength because they do not include bone quality: microarchitecture, mineralization, ability to repair damage, collagen structure, crystal size, or marrow composition. Patients with kidney disease have poor bone quality. Newman et al. now describe beneficial effects with raloxifene in an animal model of progressive kidney disease. These biomechanical measurements will be important in the development of medications to decrease fractures in patients. PMID:26759040

  19. Suspended dust in Norwegian cities

    International Nuclear Information System (INIS)

    According to calculations, at least 80 000 people in Oslo and 8 000 in Trondheim were annoyed by too much suspended dust in 2000. The dust concentration is greatest in the spring, presumably because dust is swirling up from melting snow and ice on the streets. Car traffic is the main source of the dust, except for some of the most highly exposed regions where wood-firing from old stoves contributes up to 70 percent of the dust. National targets for air quality include suspended dust, nitrogen dioxide, sulphur dioxide and benzene. Calculations show that nitrogen dioxide emissions exceeding the limit affected 4 000 people in Oslo and 1 000 people in Trondheim. The sulphur dioxide emissions in the major cities did non exceed the national quality limit; they did exceed the limit in some of the smaller industrial centres. In Trondheim, measurements show that the national limit for benzene was exceeded. Most of the emission of nitrogen dioxide comes from the road traffic. Local air pollution at times causes considerable health- and well-being problems in the larger cities and industrial centres, where a great part of the population may be at risk of early death, infection of the respiratory passage, heart- and lung diseases and cancer

  20. Bone development

    DEFF Research Database (Denmark)

    Tatara, M.R.; Tygesen, Malin Plumhoff; Sawa-Wojtanowicz, B.;

    2007-01-01

    The objective of this study was to determine the long-term effect of alpha-ketoglutarate (AKG) administration during early neonatal life on skeletal development and function, with emphasis on bone exposed to regular stress and used to serve for systemic changes monitoring, the rib. Shropshire ram...... at 146 days of life and five left and right ribs (fourth to eighth) were removed for analysis. The influence of AKG on skeletal system development was evaluated in relation to both geometrical and mechanical properties, as well as quantitative computed tomography (QCT). No significant differences between...... has a long-term effect on skeletal development when given early in neonatal life, and that changes in rib properties serve to improve chest mechanics and functioning in young animals. Moreover, neonatal administration of AKG may be considered as an effective factor enhancing proper development...

  1. Exercise, lifestyle, and your bones

    Science.gov (United States)

    Osteoporosis - exercise; Low bone density - exercise ... Osteoporosis is a disease that causes bones to become brittle and more likely to fracture (break). With osteoporosis, the bones lose density. Bone density is the amount of bone ...

  2. Estimation of high altitude Martian dust parameters

    Science.gov (United States)

    Pabari, Jayesh; Bhalodi, Pinali

    2016-07-01

    Dust devils are known to occur near the Martian surface mostly during the mid of Southern hemisphere summer and they play vital role in deciding background dust opacity in the atmosphere. The second source of high altitude Martian dust could be due to the secondary ejecta caused by impacts on Martian Moons, Phobos and Deimos. Also, the surfaces of the Moons are charged positively due to ultraviolet rays from the Sun and negatively due to space plasma currents. Such surface charging may cause fine grains to be levitated, which can easily escape the Moons. It is expected that the escaping dust form dust rings within the orbits of the Moons and therefore also around the Mars. One more possible source of high altitude Martian dust is interplanetary in nature. Due to continuous supply of the dust from various sources and also due to a kind of feedback mechanism existing between the ring or tori and the sources, the dust rings or tori can sustain over a period of time. Recently, very high altitude dust at about 1000 km has been found by MAVEN mission and it is expected that the dust may be concentrated at about 150 to 500 km. However, it is mystery how dust has reached to such high altitudes. Estimation of dust parameters before-hand is necessary to design an instrument for the detection of high altitude Martian dust from a future orbiter. In this work, we have studied the dust supply rate responsible primarily for the formation of dust ring or tori, the life time of dust particles around the Mars, the dust number density as well as the effect of solar radiation pressure and Martian oblateness on dust dynamics. The results presented in this paper may be useful to space scientists for understanding the scenario and designing an orbiter based instrument to measure the dust surrounding the Mars for solving the mystery. The further work is underway.

  3. Dust Particle Size Distributions during Spring in Yinchuan, China

    OpenAIRE

    Jiangfeng Shao; Jiandong Mao

    2016-01-01

    Dust particle size distributions in Yinchuan, China, were measured during March and April 2014, using APS-3321 sampler. The distributions were measured under different dust conditions (background, floating dust, blowing dust, and dust storm) and statistical analyses were performed. The results showed that, under different dust conditions, the instantaneous number concentrations of dust particles differed widely. For example, during blowing sand and dust storm conditions, instantaneous dust pa...

  4. Effect of Thermionic Emission on Dust-Acoustic Solitons in a Dust-Electron Plasma

    Institute of Scientific and Technical Information of China (English)

    REN Li-Wen; WANG Zheng-Xiong; LIU Yue; WANG Xiao-Gang

    2007-01-01

    The effects of thermionic emission on dust-acoustic solitons with a very small but finite amplitude in a dustelectron plasma are studied using the reductive perturbation technique. The self-consistent variation of dust charge is taken into account. It is shown that the thermionic emission could significantly increase the dust positive charge. The dependences of the phase velocity, amplitude, and width of such solitons on the dust temperature and the dust work function of dust material are plotted and discussed.

  5. Surface Modification of Fly Ashes with Carbide Slag and Its Effect on Compressive Strength and Autogenous Shrinkage of Blended Cement Pastes

    Institute of Scientific and Technical Information of China (English)

    HAO Chengwei; DENG Min; MO Liwu; LIU Kaiwei

    2012-01-01

    Surfaces of grade Ⅲ fly ashes were modified through mixing with carbide slag and calcining at 850 ℃ for 1 h.Mineralogical compositions and surface morphology of fly ashes before and after modification were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM),respectively.Effect of surface-modified fly ashes on compressive strength and autogenous shrinkage of blended cement pastes was investigated.Microstructures of cement pastes were examined by backscattered electron (BSE) imaging and mercury intrusion porosimetry (MIP).The experimental results showed that β-C2S was formed on the surfaces of fly ashes after modification.Hydration of β-C2S on the surface-modified fly ashes densified interface zone and enhanced bond strength between particles of fly ashes and hydrated clinkers.In addition,surface modification of fly ashes tended to decrease total porosity and 10-50 nm pores of cement pastes.Surface modification of fly ashes increased compressive strength and reduced autogenous shrinkage of cement pastes.

  6. Bone grafting: An overview

    Directory of Open Access Journals (Sweden)

    D. O. Joshi

    2010-08-01

    Full Text Available Bone grafting is the process by which bone is transferred from a source (donor to site (recipient. Due to trauma from accidents by speedy vehicles, falling down from height or gunshot injury particularly in human being, acquired or developmental diseases like rickets, congenital defects like abnormal bone development, wearing out because of age and overuse; lead to bone loss and to replace the loss we need the bone grafting. Osteogenesis, osteoinduction, osteoconduction, mechanical supports are the four basic mechanisms of bone graft. Bone graft can be harvested from the iliac crest, proximal tibia, proximal humerus, proximal femur, ribs and sternum. An ideal bone graft material is biologically inert, source of osteogenic, act as a mechanical support, readily available, easily adaptable in terms of size, shape, length and replaced by the host bone. Except blood, bone is grafted with greater frequency. Bone graft indicated for variety of orthopedic abnormalities, comminuted fractures, delayed unions, non-unions, arthrodesis and osteomyelitis. Bone graft can be harvested from the iliac crest, proximal tibia, proximal humerus, proximal femur, ribs and sternum. By adopting different procedure of graft preservation its antigenicity can be minimized. The concept of bone banking for obtaining bone grafts and implants is very useful for clinical application. Absolute stability require for successful incorporation. Ideal bone graft must possess osteogenic, osteoinductive and osteocon-ductive properties. Cancellous bone graft is superior to cortical bone graft. Usually autologous cancellous bone graft are used as fresh grafts where as allografts are employed as an alloimplant. None of the available type of bone grafts possesses all these properties therefore, a single type of graft cannot be recomm-ended for all types of orthopedic abnormalities. Bone grafts and implants can be selected as per clinical problems, the equipments available and preference of

  7. Managment of frontal sinus fracture: obliteration sinus with cancellous bone graft.

    Science.gov (United States)

    Muminagic, Sahib; Masic, Tarik; Babajic, Emina; Asotic, Mithat

    2011-01-01

    Frontal sinus fractures make up about 2-15% of all facial fractures.This is relatively low frequency of occurrence, but it has a large potential of complication and may involve not only the frontal sinuse but more importantly the brain and the eyes. The management depends of the complexity. If anterior wall is fractured with grossly involved nasofrontal duct (NFD) in the injury it is paramount to occlude NFD. Very often, sinus obliteration is done at the same time. In our expirience autogenous cancellous bone graft is considered to be the best grafting material. It has the less short - or long-term complications and the donor site morbidity is insignificant. PMID:21950235

  8. 2002 Kuiper prize lecture: Dust Astronomy

    Science.gov (United States)

    Grün, Eberhard; Srama, Ralf; Krüger, Harald; Kempf, Sascha; Dikarev, Valeri; Helfert, Stefan; Moragas-Klostermeyer, Georg

    2005-03-01

    Dust particles, like photons, carry information from remote sites in space and time. From knowledge of the dust particles' birthplace and their bulk properties, we can learn about the remote environment out of which the particles were formed. This approach is called "Dust Astronomy" which is carried out by means of a dust telescope on a Dust Observatory in space. Targets for a dust telescope are the local interstellar medium and nearby star forming regions, as well as comets and asteroids. Dust from interstellar and interplanetary sources is distinguished by accurately sensing their trajectories. Trajectory sensors may use the electric charge signals that are induced when charged grains fly through the detector. Modern in-situ dust impact detectors are capable of providing mass, speed, physical and chemical information of dust grains in space. A Dust Observatory mission is feasible with state-of-the-art technology. It will (1) provide the distinction between interstellar dust and interplanetary dust of cometary and asteroidal origin, (2) determine the elemental composition of impacting dust particles, and (3) monitor the fluxes of various dust components as a function of direction and particle masses.

  9. Theoretical aspects of Dust in fusion devices

    International Nuclear Information System (INIS)

    It is known that micro-particles (dust) exist in fusion devices. However, an impact of dust on plasma contamination, material migration, and performance of fusion devices is still under debate. In burning plasma experiments like ITER dust can also pose safety problems related to it's chemical activity, toxicity, tritium retention, and radioactive content. In order to address all these issues we need to understand the physics of dust generation, dynamics, and transport. In this paper, the results of recent theoretical studies of dust in fusion plasmas are reviewed. Different aspects of the physics of dust in fusion plasmas, including the processes of dust generation, charging, heating, destruction, spinning, forces acting on dust, dust collision with material walls, etc are discussed. The numerical models of these processes have been incorporated into the dust transport code DUSTT, which is capable of tracking of dust particles in fusion devices in 3D geometry. The results of the simulations of dust particle dynamics, transport, and the impact on edge plasma performance are considered. The latest results on nonlinear interactions of dust grain with tokamak plasma as well as remaining gaps in the understanding of physics of dust in fusion devices are discussed (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  10. Bone scan in rheumatology

    International Nuclear Information System (INIS)

    In this chapter a revision is made concerning different uses of bone scan in rheumatic diseases. These include reflex sympathetic dystrophy, osteomyelitis, spondyloarthropaties, metabolic bone diseases, avascular bone necrosis and bone injuries due to sports. There is as well some comments concerning pediatric pathology and orthopedics. (authors). 19 refs., 9 figs

  11. Bone Marrow Diseases

    Science.gov (United States)

    Bone marrow is the spongy tissue inside some of your bones, such as your hip and thigh bones. It contains stem cells. The stem cells can ... the platelets that help with blood clotting. With bone marrow disease, there are problems with the stem ...

  12. Bone Marrow Transplantation

    Science.gov (United States)

    Bone marrow is the spongy tissue inside some of your bones, such as your hip and thigh bones. It contains immature cells, called stem cells. The ... platelets, which help the blood to clot. A bone marrow transplant is a procedure that replaces a ...

  13. Bone grafts in dentistry

    OpenAIRE

    Prasanna Kumar; Belliappa Vinitha; Ghousia Fathima

    2013-01-01

    Bone grafts are used as a filler and scaffold to facilitate bone formation and promote wound healing. These grafts are bioresorbable and have no antigen-antibody reaction. These bone grafts act as a mineral reservoir which induces new bone formation.

  14. Bone grafts in dentistry

    Directory of Open Access Journals (Sweden)

    Prasanna Kumar

    2013-01-01

    Full Text Available Bone grafts are used as a filler and scaffold to facilitate bone formation and promote wound healing. These grafts are bioresorbable and have no antigen-antibody reaction. These bone grafts act as a mineral reservoir which induces new bone formation.

  15. BONE IN OSTEOPETROSIS

    Directory of Open Access Journals (Sweden)

    Ramkumar

    2014-04-01

    Full Text Available Osteopetrosis, a generalized developmental bone disease due to genetic disturbances, characterized by failure of bone re sorption and continuous bone formation making the bone hard, dense and brittle. Bones of intramembranous ossification and enchondrial ossification are affected genetically and symmetrically. During the process of disease the excess bone formation obliterates the cranial foramina and presses the optic, auditory and facial nerves resulting in defective vision, impaired hearing and facial paralysis. The bone formation in osteopetrosis affects bone marrow function leading to severe anemia and deficient of blood cells. The bone devoid of blood supply due to compression of blood vessels by excess formation of bone are prone to osteomyelitic changes with suppuration and pathological fracture if exposed to infection. Though the condition is chronic progressive, it produces changes leading to fatal condition, it should be studied thoroughly by everyone and hence this article presents a classical case of osteopetrosis with detailed description and discussion for the benefit of readers

  16. Dust characterization in FTU tokamak

    Energy Technology Data Exchange (ETDEWEB)

    De Angeli, M., E-mail: deangeli@ifp.cnr.it [Istituto di Fisica del Plasma – Consiglio Nazionale delle Ricerche, Milan (Italy); Maddaluno, G. [ENEA Unità Tecnica Fusione, C.R. ENEA Frascati, CP65, 00044 Frascati (Italy); Laguardia, L. [Istituto di Fisica del Plasma – Consiglio Nazionale delle Ricerche, Milan (Italy); Ripamonti, D. [Istituto per l’Energetica e le Interfasi – Consiglio Nazionale delle Ricerche, Milan (Italy); Perelli Cippo, E. [Istituto di Fisica del Plasma – Consiglio Nazionale delle Ricerche, Milan (Italy); Apicella, M.L. [ENEA Unità Tecnica Fusione, C.R. ENEA Frascati, CP65, 00044 Frascati (Italy); Conti, C. [Istituto per la Conservazione e la Valorizzazione dei Beni Culturali – CNR, Milan (Italy); Giacomi, G. [ENEA Unità Tecnica Fusione, C.R. ENEA Frascati, CP65, 00044 Frascati (Italy); Grosso, G. [Istituto di Fisica del Plasma – Consiglio Nazionale delle Ricerche, Milan (Italy)

    2015-08-15

    Dust present in the vessel of FTU has been collected and analysed. Being FTU a device with full metal plasma facing components for the whole life and equipped with a liquid lithium limiter (LLL) make FTU of special interest from a point of view of dust studies. Analyses were conducted by standard dust analysis methods and by dedicated analysis, as X-rays and neutron diffraction, to investigate the presence of lithium compounds due the presence of the LLL in FTU. Dust collected near the LLL presents a different elemental composition, namely Li compounds, compared to the dust collected in the rest of the vessel; in particular LiO{sub 2}, LiOH, and Li{sub 2}CO{sub 3}. On the basis of these results, the formation of Li{sub 2}CO{sub 3} is proposed via a two steps process. Results of fuel retention measured by thermal desorption spectroscopy (TDS) method show that fuel retention should not be an issue for FTU.

  17. Dust near luminous ultraviolet stars

    Science.gov (United States)

    Henry, Richard C.

    1993-01-01

    This report describes research activities related to the Infrared Astronomical Satellite (IRAS) sky survey. About 745 luminous stars were examined for the presence of interstellar dust heated by a nearby star. The 'cirrus' discovered by IRAS is thermal radiation from interstellar dust at moderate and high galactic latitudes. The IRAS locates the dust which must (at some level) scatter ultraviolet starlight, although it was expected that thermal emission would be found around virtually every star, most stars shown no detectable emission. And the emission found is not uniform. It is not that the star is embedded in 'an interstellar medium', but rather what is found are discrete clouds that are heated by starlight. An exception is the dearth of clouds near the very hottest stars, implying that the very hottest stars play an active role with respect to destroying or substantially modifying the dust clouds over time. The other possibility is simply that the hottest stars are located in regions lacking in dust, which is counter-intuitive. A bibliography of related journal articles is attached.

  18. Differential dust attenuation in CALIFA galaxies

    Science.gov (United States)

    Vale Asari, N.; Cid Fernandes, R.; Amorim, A. L.; Lacerda, E. A. D.; Schlickmann, M.; Wild, V.; Kennicutt, R. C.

    2016-06-01

    Dust attenuation has long been treated as a simple parameter in SED fitting. Real galaxies are, however, much more complicated: The measured dust attenuation is not a simple function of the dust optical depth, but depends strongly on galaxy inclination and the relative distribution of stars and dust. We study the nebular and stellar dust attenuation in CALIFA galaxies, and propose some empirical recipes to make the dust treatment more realistic in spectral synthesis codes. By adding optical recombination emission lines, we find better constraints for differential attenuation. Those recipes can be applied to unresolved galaxy spectra, and lead to better recovered star formation rates.

  19. Within patient radiological comparative analysis of the performance of two bone graft extenders utilized in posterolateral lumbar fusion: a retrospective case series

    Directory of Open Access Journals (Sweden)

    Geoffrey eStewart

    2016-01-01

    Full Text Available Two bone graft extenders differing in chemical composition were implanted contralaterally in 27 consecutive patients undergoing instrumented posterolateral lumbar fusion as standard of care. Bone marrow aspirate and autogenous bone graft were equally combined either with β-tricalcium phosphate (β-TCP or a hybrid biomaterial (containing hyaluronic acid but lacking a calcium salt and implanted between the transverse processes. Fusion status on each side of the vertebrae was retrospectively graded (1-5 scale on AP planar X-ray at multiple visits as available, through approximately month 12. Additionally, consolidation or resorption since prior visit for each treatment was recorded. Sides receiving β-TCP extender showed marked resorption prior to bone consolidation during the first 6 months. By contrast, sides receiving the hybrid biomaterial containing integrated hyaluronic acid showed rapid bone consolidation by week 6-8, with maintenance of initial bone volume through month 12. Fusion grade was superior for the hybrid biomaterial, differing significantly from β-TCP at day 109 and beyond. Fusion success at >month 12 was 92.9% vs 67.9% for the hybrid biomaterial and β-TCP-treated sides, respectively. The hybrid biomaterial extender demonstrated a shortened time to fusion compared to the calcium-based graft. Mode of action has been demonstrated in the literature to differ between these compositions. Therefore, choice of synthetic biomaterial composition may significantly influence mode of action of cellular events regulating appositional bone growth.

  20. Anorexia nervosa and bone.

    Science.gov (United States)

    Misra, Madhusmita; Klibanski, Anne

    2014-06-01

    Anorexia nervosa (AN) is a condition of severe low weight that is associated with low bone mass, impaired bone structure, and reduced bone strength, all of which contribute to increased fracture risk. Adolescents with AN have decreased rates of bone accrual compared with normal-weight controls, raising additional concerns of suboptimal peak bone mass and future bone health in this age group. Changes in lean mass and compartmental fat depots, and hormonal alterations secondary to nutritional factors contribute to impaired bone metabolism in AN. The best strategy to improve bone density is to regain weight and menstrual function. Oral estrogen-progesterone combinations are not effective in increasing bone density in adults or adolescents with AN, and transdermal testosterone replacement is not effective in increasing bone density in adult women with AN. However, physiological estrogen replacement as transdermal estradiol with cyclic progesterone does increase bone accrual rates in adolescents with AN to approximate that in normal-weight controls, leading to a maintenance of bone density Z-scores. A recent study has shown that risedronate increases bone density at the spine and hip in adult women with AN. However, bisphosphonates should be used with great caution in women of reproductive age, given their long half-life and potential for teratogenicity, and should be considered only in patients with low bone density and clinically significant fractures when non-pharmacological therapies for weight gain are ineffective. Further studies are necessary to determine the best therapeutic strategies for low bone density in AN. PMID:24898127

  1. Anorexia Nervosa and Bone

    Science.gov (United States)

    Misra, Madhusmita; Klibanski, Anne

    2014-01-01

    Anorexia nervosa (AN) is a condition of severe low weight that is associated with low bone mass, impaired bone structure and reduced bone strength, all of which contribute to increased fracture risk., Adolescents with AN have decreased rates of bone accrual compared with normal-weight controls, raising addition concerns of suboptimal peak bone mass and future bone health in this age group. Changes in lean mass and compartmental fat depots, hormonal alterations secondary to nutritional factors contribute to impaired bone metabolism in AN. The best strategy to improve bone density is to regain weight and menstrual function. Oral estrogen-progesterone combinations are not effective in increasing bone density in adults or adolescents with AN, and transdermal testosterone replacement is not effective in increasing bone density in adult women with AN. However, physiologic estrogen replacement as transdermal estradiol with cyclic progesterone does increase bone accrual rates in adolescents with AN to approximate that in normal-weight controls, leading to a maintenance of bone density Z-scores. A recent study has shown that risedronate increases bone density at the spine and hip in adult women with AN. However, bisphosphonates should be used with great caution in women of reproductive age given their long half-life and potential for teratogenicity, and should be considered only in patients with low bone density and clinically significant fractures when non-pharmacological therapies for weight gain are ineffective. Further studies are necessary to determine the best therapeutic strategies for low bone density in AN. PMID:24898127

  2. Glass Frit Clumping And Dusting

    Energy Technology Data Exchange (ETDEWEB)

    Steimke, J. L.

    2013-09-26

    DWPF mixes a slurry of glass frit (Frit 418) and dilute (1.5 wt%) formic acid solution with high level waste in the Slurry Mix Evaporator (SME). There would be advantages to introducing the frit in a non-slurry form to minimize water addition to the SME, however, adding completely dry frit has the potential to generate dust which could clog filters or condensers. Prior testing with another type of frit, Frit 320, and using a minimal amount of water reduced dust generation, however, the formation of hard clumps was observed. To examine options and behavior, a TTQAP [McCabe and Stone, 2013] was written to initiate tests that would address these concerns. Tests were conducted with four types of glass frit; Frit 320, DWPF Frit 418, Bekeson Frit 418 and Multi-Aspirator Frit 418. The last two frits are chemically identical to DWPF Frit 418 but smaller particles were removed by the respective vendors. Test results on Frit Clumping and Dusting are provided in this report. This report addresses the following seven questions. Short answers are provided below with more detailed answers to follow. 1. Will the addition of a small amount of water, 1.5 wt%, to dry DWPF Frit 418 greatly reduce the dust generation during handling at DWPF? a. Yes, a small scale test showed that adding a little water to the frit greatly reduced dust generation during handling. 2. Will the addition of small amounts of water to the frit cause clumping that will impair frit handling at DWPF? a. No, not with Frit 418. Although clumps were observed to form when 1.5 wt% water was mixed with DWPF Frit 418, then compressed and air-dried overnight, the clumps were easily crushed and did not form the hardened material noted when Frit 320 was tested. 3. What is the measured size distribution of dust generated when dry frit is handled? (This affects the feasibility and choice of processing equipment for removing the dust generating fraction of the frit before it is added to the SME.) a. The size distribution for

  3. Glass Frit Clumping And Dusting

    International Nuclear Information System (INIS)

    DWPF mixes a slurry of glass frit (Frit 418) and dilute (1.5 wt%) formic acid solution with high level waste in the Slurry Mix Evaporator (SME). There would be advantages to introducing the frit in a non-slurry form to minimize water addition to the SME, however, adding completely dry frit has the potential to generate dust which could clog filters or condensers. Prior testing with another type of frit, Frit 320, and using a minimal amount of water reduced dust generation, however, the formation of hard clumps was observed. To examine options and behavior, a TTQAP [McCabe and Stone, 2013] was written to initiate tests that would address these concerns. Tests were conducted with four types of glass frit; Frit 320, DWPF Frit 418, Bekeson Frit 418 and Multi-Aspirator Frit 418. The last two frits are chemically identical to DWPF Frit 418 but smaller particles were removed by the respective vendors. Test results on Frit Clumping and Dusting are provided in this report. This report addresses the following seven questions. Short answers are provided below with more detailed answers to follow. 1. Will the addition of a small amount of water, 1.5 wt%, to dry DWPF Frit 418 greatly reduce the dust generation during handling at DWPF? a. Yes, a small scale test showed that adding a little water to the frit greatly reduced dust generation during handling. 2. Will the addition of small amounts of water to the frit cause clumping that will impair frit handling at DWPF? a. No, not with Frit 418. Although clumps were observed to form when 1.5 wt% water was mixed with DWPF Frit 418, then compressed and air-dried overnight, the clumps were easily crushed and did not form the hardened material noted when Frit 320 was tested. 3. What is the measured size distribution of dust generated when dry frit is handled? (This affects the feasibility and choice of processing equipment for removing the dust generating fraction of the frit before it is added to the SME.) a. The size distribution for

  4. Bosonic string theory with dust

    International Nuclear Information System (INIS)

    We study a modified bosonic string theory that has a pressureless ‘dust’ field on the string worldsheet. The dust is a real scalar field with unit gradient which breaks conformal invariance. Hamiltonian analysis reveals a time reparametrization constraint linear in the dust field momentum and a spatial diffeomorphism constraint. This feature provides a natural ‘dust time’ gauge in analogy with the parametrized particle. In this gauge we give a Fock quantization of the theory, which is complete and self-consistent in d < 26. The Hamiltonian of the theory is not a constraint; as a consequence the Hilbert space and mass spectrum are characterized by an additional parameter, and includes the usual string spectrum as a special case. The other sectors provide new particle spectra, some of which do not have tachyons. (paper)

  5. Pulmonary retention of coal dusts

    Energy Technology Data Exchange (ETDEWEB)

    Morrow, P.E.; Gibb, F.R.; Beiter, H.; Amato, F.; Yuile, C.; Kilpper, R.W.

    1980-01-01

    The principal objectives of this study were: to determine, quantitatively, coal dust retention times in the dog lung; to test the appropriateness of a pulmonary retention model which incorporates first order rate coefficients obtained from in vitro and in vivo experiments on neutron-activated coal; to acquire a temporal description of the pulmonary disposition of the retained coal dust, and to compare the behavior of two different Pennsylvania coals in the foregoing regards. The principal findings include: retention half-times for both coals of approximately 2 years following single, hour-long exposures; a vivid association of the retained coal dust with the pulmonic lymphatics; and a general validation of the retention model.

  6. Desert Dust and Monsoon Rain

    Science.gov (United States)

    Lau, William K. M.; Kim, Kyu-Myong

    2014-01-01

    For centuries, inhabitants of the Indian subcontinent have know that heavy dust events brought on by strong winds occur frequently in the pre-monsoon season, before the onset of heavy rain. Yet scientists have never seriously considered the possibility that natural dust can affect monsoon rainfall. Up to now, most studies of the impacts of aerosols on Indian monsoon rainfall have focused on anthropogenic aerosols in the context of climate change. However, a few recent studies have show that aerosols from antropogenic and natural sources over the Indian subcontinent may affect the transition from break to active monsoon phases on short timescales of days to weeks. Writing in Nature Geoscience, Vinoj and colleagues describe how they have shown that desert dust aerosols over the Arabian Sea and West Asia can strenghten the summer monsoon over the Indial subcontinent in a matter of days.

  7. Dust remobilization in fusion plasmas

    CERN Document Server

    Tolias, P; De Angeli, M; De Temmerman, G; Ripamonti, D; Riva, G; Bykov, I; Shalpegin, A; Vignitchouk, L; Brochard, F; Bystrov, K; Bardin, S; Litnovsky, A

    2016-01-01

    The first combined experimental and theoretical studies of dust remobilization by plasma forces are reported. The main theoretical aspects of remobilization are analyzed. In particular, the dominant role of adhesive forces is highlighted and generic remobilization conditions - detachment, sliding, rolling - are formulated. A novel experimental technique is proposed, based on controlled adhesion of dust grains on tungsten samples combined with detailed mapping of the dust deposition profile prior and post plasma exposure. Proof-of-principle experiments in the TEXTOR tokamak and the EXTRAP-T2R reversed-field pinch are presented. The versatile environment of the linear device Pilot-PSI allowed for experiments with different magnetic field topologies and varying plasma conditions that were complemented with camera observations.

  8. Evaluation of Osteoconductive and Osteogenic Potential of a Dentin-Based Bone Substitute Using a Calvarial Defect Model

    Directory of Open Access Journals (Sweden)

    Ibrahim Hussain

    2012-01-01

    Full Text Available The aim of this study was to assess the osteoconductive and osteogenic properties of processed bovine dentin using a robust rabbit calvarial defect model. In total, 16 New Zealand White rabbits were operated to create three circular defects in the calvaria. One defect was left unfilled, one filled with collected autogenous bone, and the third defect was filled with the dentin-based bone substitute. Following surgery and after a healing period of either 1 or 6 weeks, a CT scan was obtained. Following sacrificing, the tissues were processed for histological examination. The CT data showed the density in the area grafted with the dentin-based material was higher than the surrounding bone and the areas grafted with autologous bone after 1 week and 6 weeks of healing. The area left unfilled remained an empty defect after 1 week and 6 weeks. Histological examination of the defects filled with the dentin product after 6 weeks showed soft tissue encapsulation around the dentin particles. It can be concluded that the rabbit calvarial model used in this study is a robust model for the assessment of bone materials. Bovine dentin is a biostable material; however, it may not be suitable for repairing large 4-wall defects.

  9. [Microdestruction of the bone].

    Science.gov (United States)

    Iankovskiĭ, V É

    2014-01-01

    The objective of the present study was the detection of microcracks in the compact bone tissue surrounding the fracture and in deformed bone undergoing subcritical loading. The portions of deformed bone tissue and terminal fragments of broken bones were obtained in the form of blocks longitudinally sawcut from the regions of primary and secondary bone rupture. A total of 300 such blocks were available for the examination. All portions of the deformed bone tissue and terminal fragments of broken bones showed up microcracks commensurate with the bone structures. They were actually hardened traces of deformation that preceded the fracture and reflected the volume of the destroyed bone tissue; moreover, in certain cases they allowed to identify the kind of the object that exerted the external action (either a blow or slow bending). PMID:25269164

  10. Durable Dust Repellent Coating for Metals Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Durable Dust Repellent Coating (DDRC) consists of nano-phase silica, titania, or other oxide coatings to repel dust in a vacuum environment over a wide range of...

  11. Dynamics of Dust Clouds in Plasma

    International Nuclear Information System (INIS)

    We study a dynamics of dust clouds embedded in the infinite uniform initially plasma using computer simulation. In the one dimension, the movement of dust particles and ions is governed by cold hydrodynamics equations, electrons are assumed to be in thermal equilibrium. It is assumed that the forces on the dust consist of electrostatic forces and ion drag forces. The spatial distributions of parameters were obtained at various initial densities of dust grains at different times. Results show the expansion of dust clouds at low initial dust grain density, which is evidence of exceeding the electrostatic force over the ion drag force. At the increasing of dust density oscillations of the central part of dust cloud are observed

  12. Dust Mitigation for the Lunar Surface Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The lunar surface is to a large extent covered with a dust layer several meters thick. Known as lunar regolith, it poses a hazard in the form of dust clouds being...

  13. The global distribution of mineral dust

    International Nuclear Information System (INIS)

    Dust aerosol particles produced by wind erosion in arid and semi arid regions affect climate and air quality, but the magnitude of these effects is largely unquantified. The major dust source regions include the Sahara, the Arabian and Asian deserts; global annual dust emissions are currently estimated to range between 1000 and 3000 Mt/yr. Dust aerosol can be transported over long distances of thousands of kilometers, e.g. from source regions in the Saharan desert over the North Atlantic, or from the Asian deserts towards the Pacific Ocean. The atmospheric dust load varies considerably on different timescales. While dust aerosol distribution and dust effects are important on global scales, they strongly depend on dust emissions that are controlled on small spatial and temporal scales.

  14. Alkaline leaching of iron and steelmaking dust

    OpenAIRE

    Stafanova, Anna; Aromaa, Jari

    2012-01-01

    Steel production generates significant quantities of dust and sludge in blast furnaces (BF),basic oxygen furnaces (BOF), and electric arc furnaces (EAF). These dusts contain toxicelements, such as heavy metals, and are thus classified as harmful waste making the disposalof them expensive. In addition, direct recycling of dust back to steel production is hindered dueto the presence of zinc. In this literature survey the alkaline leaching of zinc from iron and steelmaking dusts isreviewed. T...

  15. Metal Dusting of Heat-Resistant Alloys

    OpenAIRE

    Al-Meshari, Abdulaziz I.

    2008-01-01

    Metal dusting leads to disintegration of such alloys as iron and nickel-based into a ?dust? of particulate metal, metal carbide, carbon, and/or oxide. It occurs in strongly carburising environments at 400-900?C. Literature survey has shown that alloys behave differently in metal dusting conditions based on their composition and the environment. Metal dusting mechanisms for iron and nickel-based alloys have been proposed but, nevertheless, have not been agreed upon and numerous modifications t...

  16. History and Applications of Dust Devil Studies

    Science.gov (United States)

    Lorenz, Ralph D.; Balme, Matthew R.; Gu, Zhaolin; Kahanpää, Henrik; Klose, Martina; Kurgansky, Michael V.; Patel, Manish R.; Reiss, Dennis; Rossi, Angelo Pio; Spiga, Aymeric; Takemi, Tetsuya; Wei, Wei

    2016-04-01

    Studies of dust devils, and their impact on society, are reviewed. Dust devils have been noted since antiquity, and have been documented in many countries, as well as on the planet Mars. As time-variable vortex entities, they have become a cultural motif. Three major stimuli of dust devil research are identified, nuclear testing, terrestrial climate studies, and perhaps most significantly, Mars research. Dust devils present an occasional safety hazard to light structures and have caused several deaths.

  17. Radio frequency discharge with dust particles

    NARCIS (Netherlands)

    Chutov, Y. I.; W. J. Goedheer,; Kravchenko, O. Y.; Zuz, V. M.; Yan, M.; Martins, R.; Ferreira, I.; Fortunato, E.; Kroesen, G.

    2000-01-01

    A 1D PIC/MCC method has been developed for computer simulations of low-pressure RF discharges with dust particles using the method for dust-free discharges. A RF discharge in argon with dust particles distributed uniformly in the interelectrode gap is simulated at parameters providing a possibility

  18. The dust debris around HR 4796

    Science.gov (United States)

    Jura, M.

    1991-01-01

    The IRAS data strongly suggest that there is dust debris around the main-sequence A star HR 4796. The optical depth of the dust cloud around HR 4796 is probably twice that around Beta Pic, the main-sequence star in the Bright Star Catalog which was previously thought to have the most opaque dust debris cloud.

  19. Cyclonic separation of urate dust

    International Nuclear Information System (INIS)

    Size of particles of uranate dust wich can be entrained by hot gases leaving a multiple-hearth furnace is determined. The convenience of the installation of a cyclone is discussed considering power of the fume-extractor and pressure-drop permissible in the system. (author)

  20. 75 FR 3881 - Combustible Dust

    Science.gov (United States)

    2010-01-25

    ... Notice of Proposed Rulemaking (ANPR) (74 FR 54334) requesting comments, including data and other...), 29 CFR part 1911, and Secretary's Order 5-2007 (72 FR 31160). Signed at Washington, DC, on January 19... Occupational Safety and Health Administration 29 CFR Part 1910 RIN 1218-AC41 Combustible Dust...

  1. Dust levitation about Itokawa's equator

    Science.gov (United States)

    Hartzell, C.; Zimmerman, M.; Takahashi, Y.

    2014-07-01

    Introduction: Electrostatic dust motion has been hypothesized to occur on the asteroids, due to the observations of the Eros dust ponds [1] and the potential presence of such a phenomenon on the Moon [2]. There are two phases of electrostatic dust motion: lofting and the subsequent trajectories. The feasibility of electrostatic dust lofting can be assessed by comparing the strength of the electrostatic force to the gravity and cohesion which hold the grain on to the surface [3--5]. The motion of the dust grains after they detach from the surface can be described as either ballistic, escaping, or levitating. We are interested in dust levitation because it could potentially redistribute grains on the surface of an asteroid (for instance, producing the Eros dust ponds) and it could also be hazardous to spacecraft. Specifically, levitating dust could obscure the observations of surface-based spacecraft or possibly trigger obstacle avoidance routines during landing. Dust Levitation: Dust levitation is defined as the altitude oscillation of grains prior to their redeposition on the surface of an asteroid. Levitation occurs about equilibria where the electrostatic and gravity forces on the grain are equal and opposite. An equilibrium state is defined as a position and charge for a specific grain size. We have previously identified equilibria using a 1D plasma model and a simple gravity model for Itokawa [6]. In this simple model, the largest grain that was capable of stable levitation above Itokawa was 3 microns (in radius) [6]. Additionally, we have shown that levitating dust grains follow the variation in the equilibria for a rotating asteroid (i.e., the grain continues to oscillate about an equilibrium state that approaches the surface) [7]. Due to the nonspherical shape of Itokawa, both the gravity and plasma environments are much more complicated than the 1D approximations made in our previous work. Thus, in order to accurately assess the feasibility of dust

  2. House Dust Mite Respiratory Allergy

    DEFF Research Database (Denmark)

    Calderón, Moisés A; Kleine-Tebbe, Jörg; Linneberg, Allan;

    2015-01-01

    Although house dust mite (HDM) allergy is a major cause of respiratory allergic disease, specific diagnosis and effective treatment both present unresolved challenges. Guidelines for the treatment of allergic rhinitis and asthma are well supported in the literature, but specific evidence on the...

  3. Technical Note: High-resolution mineralogical database of dust-productive soils for atmospheric dust modeling

    OpenAIRE

    S. Nickovic; Vukovic, A.; M. Vujadinovic; V. Djurdjevic; G. Pejanovic

    2012-01-01

    Dust storms and associated mineral aerosol transport are driven primarily by meso- and synoptic-scale atmospheric processes. It is therefore essential that the dust aerosol process and background atmospheric conditions that drive dust emissions and atmospheric transport are represented with sufficiently well-resolved spatial and temporal features. The effects of airborne dust interactions with the environment determine the mineral composition of dust particles. The fractions of various minera...

  4. Slow strain rate stress corrosion cracking behaviour of as-welded and plasma electrolytic oxidation treated AZ31HP magnesium alloy autogenous laser beam weldment

    International Nuclear Information System (INIS)

    The joining of a thin section AZ31HP magnesium alloy was accomplished by laser beam welding in the autogenous mode using a Nd-YAG laser system. Micro hardness evaluation and slow strain rate tensile (SSRT) tests in air revealed that the weld metal had near-matching mechanical properties corresponding to that of the parent alloy. However, in terms of stress corrosion cracking (SCC) resistance as assessed by SSRT tests in ASTM D1384 solution, the weldment was found to have higher susceptibility compared to the parent alloy. The fracture in the weld metal/fusion boundary/HAZ interface suggested that the failure was due to the grain coarsening at the very narrow heat affected zone. The resistance to SCC of the parent alloy and the weldment specimens was found to improve slightly by the application of plasma electrolytic oxidation (PEO) coating from a silicate based electrolyte.

  5. Characterization of the inflammatory response to four commercial bone graft substitutes using a murine biocompatibility model

    Directory of Open Access Journals (Sweden)

    Markel DC

    2012-01-01

    Full Text Available David C Markel1, S Trent Guthrie2, Bin Wu3, Zheng Song4, Paul H Wooley41Department of Orthopaedics, Providence Hospital and Medical Centers, Southfield, MI, 2Henry Ford Hospital, Detroit, MI, 3Department of Biomedical Engineering, Wayne State University, Detroit, MI, 4Orthopaedic Research Institute, Wichita, KS, USAAbstract: Bone grafting is utilized in nearly all orthopedic subspecialties and in most anatomic regions. Bone graft substitutes have the potential to offer similar efficacy as autogenous grafts without the morbidity of harvest. Several studies have noted the efficacy of new-generation bone substitute products, but few studies have evaluated their safety. This study characterizes and quantifies the inflammatory reaction to four different commercially available bone graft substitutes, which were examined using the in vivo murine air pouch biocompatibility model. One coralline hydroxyapatite product was chosen as an example of a purely osteoconductive material. Three demineralized bone matrix products were chosen to represent products that are both osteoconductive and osteoinductive. Samples were implanted in a murine air pouch and harvested after 14 days in situ. Pouch fluid was extracted, mRNA isolated, and reverse transcription polymerase chain reactions carried out to detect interleukin-1 gene expression as a marker for inflammation. In addition, multiple histological characteristics were examined to quantify cellular responses to the implanted materials. All bone graft substitutes induced a significant inflammatory response compared with negative controls. Histology and polymerase chain reaction data indicated that the level of inflammatory reaction was elevated in materials with a higher demineralized bone matrix to carrier proportion. The hydroxyapatite product generated a low inflammatory reaction. In conclusion, this study used an in vivo model of biocompatibility to demonstrate that a significant inflammatory reaction occurs

  6. How Is Bone Cancer Diagnosed?

    Science.gov (United States)

    ... with bone cancer. Accurate diagnosis of a bone tumor often depends on combining information about its location (what bone is affected and even which part of the bone is involved), appearance on x-rays, and appearance under a microscope. ...

  7. Bone marrow (stem cell) donation

    Science.gov (United States)

    ... lymphoma , and myeloma can be treated with a bone marrow transplant . This is now often called a stem cell ... are two types of bone marrow donation: Autologous bone marrow transplant is when people donate their own bone marrow. " ...

  8. Bone Loss in IBD

    Science.gov (United States)

    ... DENSITY? Although bone seems as hard as a rock, it’s actually living tissue. Throughout your life, old ... available Bone Loss (.pdf) File: 290 KB 733 Third Avenue, Suite 510, New York, NY 10017 | 800- ...

  9. Bone mineral density test

    Science.gov (United States)

    ... Paula FJA, Black DM, Rosen CJ. Osteoporosis and bone biology.In: Melmed S, Polonsky KS, Larsen PR, Kronenberg HM, eds. Williams Textbook of Endocrinology . 13th ed. Philadelphia, ... Bone-density testing interval and transition to osteoporosis in ...

  10. Bone mineral density test

    Science.gov (United States)

    BMD test; Bone density test; Bone densitometry; DEXA scan; DXA; Dual-energy x-ray absorptiometry; p-DEXA; Osteoporosis-BMD ... need to undress. This scan is the best test to predict your risk of fractures. Peripheral DEXA ( ...

  11. Smoking and Bone Health

    Science.gov (United States)

    ... It has been called a childhood disease with old age consequences because building healthy bones in youth helps ... stronger. Weight-bearing exercise that forces you to work against gravity is the best exercise for bone. ...

  12. In vitro culture of large bone substitutes in a new bioreactor: importance of the flow direction

    International Nuclear Information System (INIS)

    New biomaterials combined with osteogenic cells are now being developed as an alternative to autogeneous bone grafts when the skeletal defect reaches a critical size. Yet, the size issue appears to be a key obstacle in the development of bone tissue engineering. Bioreactors are needed to allow the in vitro expansion of cells inside large bulk materials under appropriate conditions. However, no bioreactor has yet been designed for large-scale 3D structures and custom-made scaffolds. In this study, we evaluate the efficiency of a new bioreactor for the in vitro development of large bone substitutes, ensuring the perfusion of large ceramic scaffolds by the nutritive medium. The survival and proliferation of cells inside the scaffolds after 7 and 28 days in this dynamic culture system and the impact of the direction of the flow circulation are evaluated. The follow-up of glucose consumption, DNA quantification and microscopic evaluation all confirmed cell survival and proliferation for a sample under dynamic culture conditions, whereas static culture leads to the death of cells inside the scaffolds. Two directions of flow perfusion were assayed; the convergent direction leads to enhanced results compared to divergent flow

  13. In vitro culture of large bone substitutes in a new bioreactor: importance of the flow direction

    Energy Technology Data Exchange (ETDEWEB)

    Olivier, V [Laboratoire de Recherche sur les Biomateriaux et les Biotechnologies (LR2B, UPRES EA 2603), Universite du Littoral Cote-d' Opale, Boulogne-sur-Mer (France); Hivart, Ph [Laboratoire de Recherche sur les Biomateriaux et les Biotechnologies (LR2B, UPRES EA 2603), Universite du Littoral Cote-d' Opale, Boulogne-sur-Mer (France); Descamps, M [Laboratoire des Materiaux et Procedes, Universite de Valenciennes et du Hainaut-Cambresis (LMP, UPRES EA 2443), Maubeuge (France); Hardouin, P [Laboratoire de Recherche sur les Biomateriaux et les Biotechnologies (LR2B, UPRES EA 2603), Universite du Littoral Cote-d' Opale, Boulogne-sur-Mer (France)

    2007-09-15

    New biomaterials combined with osteogenic cells are now being developed as an alternative to autogeneous bone grafts when the skeletal defect reaches a critical size. Yet, the size issue appears to be a key obstacle in the development of bone tissue engineering. Bioreactors are needed to allow the in vitro expansion of cells inside large bulk materials under appropriate conditions. However, no bioreactor has yet been designed for large-scale 3D structures and custom-made scaffolds. In this study, we evaluate the efficiency of a new bioreactor for the in vitro development of large bone substitutes, ensuring the perfusion of large ceramic scaffolds by the nutritive medium. The survival and proliferation of cells inside the scaffolds after 7 and 28 days in this dynamic culture system and the impact of the direction of the flow circulation are evaluated. The follow-up of glucose consumption, DNA quantification and microscopic evaluation all confirmed cell survival and proliferation for a sample under dynamic culture conditions, whereas static culture leads to the death of cells inside the scaffolds. Two directions of flow perfusion were assayed; the convergent direction leads to enhanced results compared to divergent flow.

  14. On the Feasibility of Utilizing Allogeneic Bone Blocks for Atrophic Maxillary Augmentation

    Directory of Open Access Journals (Sweden)

    Alberto Monje

    2014-01-01

    Full Text Available Purpose. This systematic review was aimed at assessing the feasibility by means of survival rate, histologic analysis, and causes of failure of allogeneic block grafts for augmenting the atrophic maxilla. Material and Methods. A literature search was conducted by one reviewer in several databases. Articles were included in this systematic review if they were human clinical trials in which outcomes of allogeneic bone block grafts were studied by means of survival rate. In addition other factors were extracted in order to assess their influence upon graft failure. Results. Fifteen articles fulfilled the inclusion criteria and subsequently were analyzed in this systematic review. A total of 361 block grafts could be followed 4 to 9 months after the surgery, of which 9 (2.4% failed within 1 month to 2 months after the surgery. Additionally, a weighed mean 4.79 mm (95% CI: 4.51–5.08 horizontal bone gain was computed from 119 grafted sites in 5 studies. Regarding implant cumulative survival rate, the weighed mean was 96.9% (95% CI: 92.8–98.7%, computed from 228 implants over a mean follow-up period of 23.9 months. Histologic analysis showed that allogeneic block grafts behave differently in the early stages of healing when compared to autogenous block grafts. Conclusion. Atrophied maxillary reconstruction with allogeneic bone block grafts represents a reliable option as shown by low block graft failure rate, minimal resorption, and high implant survival rate.

  15. Bone regeneration in dentistry

    OpenAIRE

    Tonelli, Paolo; Duvina, Marco; Barbato, Luigi; Biondi, Eleonora; Nuti, Niccolò; Brancato, Leila; Rose, Giovanna Delle

    2011-01-01

    The edentulism of the jaws and the periodontal disease represent conditions that frequently leads to disruption of the alveolar bone. The loss of the tooth and of its bone of support lead to the creation of crestal defects or situation of maxillary atrophy. The restoration of a functional condition involves the use of endosseous implants who require adequate bone volume, to deal with the masticatory load. In such situations the bone need to be regenerated, taking advantage of the biological p...

  16. Eating disorders and bone.

    Science.gov (United States)

    Tomlinson, Dale; Morgan, Sarah L

    2013-01-01

    Low bone mineral density (BMD) is a frequent and often-overlooked consequence of eating disorders, in particular anorexia nervosa and eating disorders associated with the female athlete triad. The causes of low BMD are multifactorial and include low peak bone mass accrual, accelerated bone resorption, and changes in bone microarchitecture. Early diagnosis and interventions focused on nutritional rehabilitation and weight gain reduce the risk of further BMD deficits and fractures. PMID:24094471

  17. Bone densitometry and osteoporosis

    International Nuclear Information System (INIS)

    The purpose of this book is to provide a perspective on the current status of bone densitometry and its relevance to osteoporosis diagnosis and management. Therefore, this book will give the reader an introduction to the nature of osteoporosis, its pathophysiology and epidemiology, and the clinical consequences of performing bone densitometry. Aside from standard bone densitometry, newer technologies such as quantitative ultrasound techniques, magnetic resonance imaging and bone structure analysis are discussed in the context of diagnosing osteoporosis. (orig.)

  18. BONE MECHANOTRANSDUCTION: A REVIEW

    OpenAIRE

    Reis, Joana; Capela e Silva, Fernando; Queiroga, Cristina; Lucena, Sónia; Potes, José

    2011-01-01

    This review focus on the bone physiology and mechanotransduction elements and mechanisms. Bone biology and architecture is deeply related to the mechanical environment. Orthopaedic implants cause profound changes in the biomechanics and electrophysiology of the skeleton. In the context of biomedical engineering, a deep reflexion on bone physiology and electromechanics is needed. Strategic development of new biomaterials and devices that respect and promote continuity with bone str...

  19. Bone cysts: unicameral and aneurysmal bone cyst.

    Science.gov (United States)

    Mascard, E; Gomez-Brouchet, A; Lambot, K

    2015-02-01

    Simple and aneurysmal bone cysts are benign lytic bone lesions, usually encountered in children and adolescents. Simple bone cyst is a cystic, fluid-filled lesion, which may be unicameral (UBC) or partially separated. UBC can involve all bones, but usually the long bone metaphysis and otherwise primarily the proximal humerus and proximal femur. The classic aneurysmal bone cyst (ABC) is an expansive and hemorrhagic tumor, usually showing characteristic translocation. About 30% of ABCs are secondary, without translocation; they occur in reaction to another, usually benign, bone lesion. ABCs are metaphyseal, excentric, bulging, fluid-filled and multicameral, and may develop in all bones of the skeleton. On MRI, the fluid level is evocative. It is mandatory to distinguish ABC from UBC, as prognosis and treatment are different. UBCs resolve spontaneously between adolescence and adulthood; the main concern is the risk of pathologic fracture. Treatment in non-threatening forms consists in intracystic injection of methylprednisolone. When there is a risk of fracture, especially of the femoral neck, surgery with curettage, filling with bone substitute or graft and osteosynthesis may be required. ABCs are potentially more aggressive, with a risk of bone destruction. Diagnosis must systematically be confirmed by biopsy, identifying soft-tissue parts, as telangiectatic sarcoma can mimic ABC. Intra-lesional sclerotherapy with alcohol is an effective treatment. In spinal ABC and in aggressive lesions with a risk of fracture, surgical treatment should be preferred, possibly after preoperative embolization. The risk of malignant transformation is very low, except in case of radiation therapy. PMID:25579825

  20. Bone allograft and implant fixation tested under influence of bio-burden reduction, periosteal augmentation and topical antibiotics. Animal experimental studies.

    Science.gov (United States)

    Barckman, Jeppe

    2014-01-01

    Loosening of an artificial joint prosthesis is a painful and debilitating condition that can be treated only by re-operation. Re-operations accounted for approximately 15% of all hip replacement operations performed in Denmark between the year 1995 and 2010. The process of loosening is often accompanied by destructive inflammation and osteolysis, which leads to insufficient bone stock that often requires extensive bone grafting. Impacted morselized bone graft is a well-established method for improving the amount and quality of bone stock that ensures sufficient stability and anchorage of the revision implants. Among bone graft options, the autologous bone graft is considered the gold standard. It is naturally biocompatible, but its use in revision surgery is curtailed by its limited volume and by considerable donor site morbidity. Allograft bone is readily available and is the most commonly used graft material. However, it has been shown that the incorporation of allograft bone into the host bone is not always complete, and substantial fibrous tissue formation has been described. A reason for this may be that allograft bone is a foreign tissue, which, contrary to autogenic bone, may induce an immunogenic response that leads to increased fibrous tissue formation. Furthermore, the fresh-frozen allograft has minimal osteoinductive and no osteogenic capacity. The studies in this thesis have investigated ways of improving the incorporation of allograft bone by adding osteoinductive cells from the periosteum and reducing the immunogenic load of the allograft bone by rinsing. Furthermore, the impact of antibiotic protection of the bone graft has been evaluated. The same experimental implant model was used in all three studies. This model enables evaluation of early implant fixation and osseointegration of an uncemented implant surrounded by impacted morselized bone graft. Unloaded gap implants were inserted into the metaphysis of the proximal tibia (Study I) and distal

  1. Status and Future of Dust Storm Forecasting

    Science.gov (United States)

    Westphal, D. L.

    2002-12-01

    In recent years, increased attention has been given to the large amounts of airborne dust derived from the deserts and desertified areas of the world and transported over scales ranging from local to global. This dust can have positive and negative impacts on human activities and the environment, including modifying cloud formation, fertilizing the ocean, degrading air quality, reducing visibility, transporting pathogens, and inducing respiratory problems. The atmospheric radiative forcing by the dust has implications for global climate change and presently is one of the largest unknowns in climate models. These uncertainties have lead to much of the funding for research into the sources, properties, and fate of atmospheric dust. As a result of advances in numerical weather prediction over the past decades and the recent climate research, we are now in a position to produce operational dust storm forecasts. International organizations and national agencies are developing programs for dust forecasting. The approaches and applications of dust detection and forecasting are as varied as the nations that are developing the models. The basic components of a dust forecasting system include atmospheric forcing, dust production, and dust microphysics. The forecasting applications include air and auto traffic safety, shipping, health, national security, climate and weather. This presentation will summarize the methods of dust storm forecasting and illustrate the various applications. The major remaining uncertainties (e.g. sources and initialization) will be discussed as well as approaches for solving those problems.

  2. ORIGIN OF DUST AROUND V1309 SCO

    International Nuclear Information System (INIS)

    The origin of dust grains in the interstellar medium is still an unanswered problem. Nicholls et al. found the presence of a significant amount of dust around V1309 Sco, which may originate from the merger of a contact binary. We investigate the origin of dust around V1309 Sco and suggest that these dust grains are produced in the binary-merger ejecta. By means of the AGBDUST code, we estimate that ∼5.2 × 10–4 M☉ dust grains are produced with a radii of ∼10–5 cm. These dust grains are mainly composed of silicate and iron grains. Because the mass of the binary merger ejecta is very small, the contribution of dust produced by binary merger ejecta to the overall dust production in the interstellar medium is negligible. However, it is important to note that the discovery of a significant amount of dust around V1309 Sco offers a direct support for the idea that common-envelope ejecta provides an ideal environment for dust formation and growth. Therefore, we confirm that common envelope ejecta can be important source of cosmic dust

  3. Menopause and Bone Loss

    Science.gov (United States)

    Fact Sheet & Menopause Bone Loss How are bone loss and menopause related? Throughout life your body keeps a balance between the loss ... The sooner you take steps to prevent bone loss, the lower your risk of osteoporosis later in life. If you are skipping menstrual periods, have had ...

  4. What's a Funny Bone?

    Science.gov (United States)

    ... Help White House Lunch Recipes What's a Funny Bone? KidsHealth > For Kids > What's a Funny Bone? Print A A A Text Size Have you ... prickly kind of dull pain? That's your funny bone! It doesn't really hurt as much as ...

  5. Possible influence of dust on hurricane genesis

    Science.gov (United States)

    Bretl, Sebastian; Reutter, Philipp; Raible, Christoph C.; Ferrachat, Sylvaine; Lohmann, Ulrike

    2014-05-01

    Tropical Cyclones (TCs) belong to the most extreme events in nature. In the past decade, the possible impact of dust on Atlantic hurricanes receives growing interest. As mineral dust is able to absorb incoming solar radiation and therefore warm the surrounding air, the presence of dust can lead to a reduction of sea surface temperature (SST) and an increase in atmospheric stability. Furthermore, resulting baroclinic effects and the dry Saharan easterly jet lead to an enhanced vertical shear of the horizontal winds. SST, stability, moisture and vertical wind shear are known to potentially impact hurricane activity. But how Saharan dust influences these prerequisites for hurricane formation is not yet clear. Some dynamical mechanisms induced by the SAL might even strengthen hurricanes. An adequate framework for investigating the possible impact of dust on hurricanes is comparing high resolution simulations (~0.5°x0.5°, 31 vertical levels) with and without radiatively active dust aerosols. To accomplish this task, we are using the general circulation model ECHAM6 coupled to a modified version of the aerosol model HAM, ECHAM6-HAM-Dust. Instead of the five aerosol species HAM normally contains, the modified version takes only insoluble dust into account, but modifies the scavenging parameters in order to have a similar lifetime of dust as in the full ECHAM6-HAM. All remaining aerosols are prescribed. To evaluate the effects of dust on hurricanes, a TC detection and tracking method is applied on the results. ECHAM6-HAM-Dust was used in two configurations, one with radiatively active dust aerosols and one with dust being not radiatively active. For both set-ups, 10 Monte-Carlo simulations of the year 2005 were performed. A statistical method which identifies controlling parameters of hurricane genesis was applied on North Atlantic developing and non-developing disturbances in all simulations, comparing storms in the two sets of simulations. Hereby, dust can be assigned

  6. Coupling Mars' Dust and Water Cycles: Effects on Dust Lifting Vigor, Spatial Extent and Seasonality

    Science.gov (United States)

    Kahre, M. A.; Hollingsworth, J. L.; Haberle, R. M.; Montmessin, F.

    2012-01-01

    The dust cycle is an important component of Mars' current climate system. Airborne dust affects the radiative balance of the atmosphere, thus greatly influencing the thermal and dynamical state of the atmosphere. Dust raising events on Mars occur at spatial scales ranging from meters to planet-wide. Although the occurrence and season of large regional and global dust storms are highly variable from one year to the next, there are many features of the dust cycle that occur year after year. Generally, a low-level dust haze is maintained during northern spring and summer, while elevated levels of atmospheric dust occur during northern autumn and winter. During years without global-scale dust storms, two peaks in total dust loading were observed by MGS/TES: one peak occurred before northern winter solstice at Ls 200-240, and one peak occurred after northern winter solstice at L(sub s) 305-340. These maxima in dust loading are thought to be associated with transient eddy activity in the northern hemisphere, which has been observed to maximize pre- and post-solstice. Interactive dust cycle studies with Mars General Circulation Models (MGCMs) have included the lifting, transport, and sedimentation of radiatively active dust. Although the predicted global dust loadings from these simulations capture some aspects of the observed dust cycle, there are marked differences between the simulated and observed dust cycles. Most notably, the maximum dust loading is robustly predicted by models to occur near northern winter solstice and is due to dust lifting associated with down slope flows on the flanks of the Hellas basin. Thus far, models have had difficulty simulating the observed pre- and post- solstice peaks in dust loading. Interactive dust cycle studies typically have not included the formation of water ice clouds or their radiative effects. Water ice clouds can influence the dust cycle by scavenging dust from atmosphere and by interacting with solar and infrared radiation

  7. Enzymatic maceration of bone

    DEFF Research Database (Denmark)

    Uhre, Marie-Louise; Eriksen, Anne Marie; Simonsen, Kim Pilkjær;

    2015-01-01

    afterwards macerated by one of the two methods. DNA extraction was performed to see the effect of the macerations on DNA preservation. Furthermore, the bone pieces were examined in a stereomicroscope to assess for any bone damage. The results demonstrated that both methods removed all flesh/soft tissue from...... the bones. The DNA analysis showed that DNA was preserved on all the pieces of bones which were examined. Finally, the investigation suggests that enzyme maceration could be gentler on the bones, as the edges appeared less frayed. The enzyme maceration was also a quicker method; it took three hours...

  8. Tin in Human Bones

    OpenAIRE

    Jambor, Jaroslav; Smreka, Vâclav

    1993-01-01

    TIN IN HUMAN BONES. The tin content in the bones of 149 skeletons from the 1st - 5th centuries A.D., and of 11 individuals of the recent population was determined. The bone samples were carbonized and analyzed through emission spectroscopy with a.c. excitation. The tin content in bones of recent populations not exposed to extra tin supply is about one order of magnitude higher than is the case with the bones od some populations that lived at the beginning of our era. The distribut...

  9. Disk evolution: dust and gas*

    Directory of Open Access Journals (Sweden)

    Dominik Carsten

    2015-01-01

    Full Text Available Disks are a natural by-product of start formation. Just like the formation if a star is a lengthy process that goes through many stages, disks around young stars evolve my processing matter through the disk and dumping it onto the star. The solid and gaseous components of disks do not always evolve together - dust-gas separation can take place, dust grains may grow. In this chapter we attempt a brief overview of processes that shape this evolution, in a way that is useful as a background to the other chapters in this lecture series. As such, the chapter does not aim for completeness or being up to date with some of the most recent developments.

  10. Dust alignment in astrophysical environments

    Science.gov (United States)

    Lazarian, Alex; Thiem Hoang, Chi

    Dust is known to be aligned in interstellar medium and the arising polarization is extensively used to trace magnetic fields. What process aligns dust grains was one of the most long-standing problems of astrophysics in spite of the persistent efforts to solve it. For years the Davis-Greenstein paramagnetic alignment was the primary candidate for explaining grain alignment. However, the situation is different now and the most promising mechanism is associated with radiative torques (RATs) acting on irregular grains. I shall present the analytical theory of RAT alignment, discuss the observational tests that support this theory. I shall also discuss in what situations we expect to see the dominance of paramagnetic alignment.

  11. Effect of bone marrow and low power lasers on fracture healing with destruction of both periosteum and endosteum in rabbits

    Directory of Open Access Journals (Sweden)

    M. G. Thanoon

    2010-01-01

    Full Text Available Ten mature rabbits of local breed were used in this study; weighing between 1.5 to 1.75 kg and aged about 1–2 years. These animals were divided into two equal groups; in group A destruction of both periosteum and endosteum was done one centimeter from each side of mid-shaft femoral bone fracture, then sufficient amount of autogenously bone marrow was injected directly at the fracture site after immobilization by intramedullary pin. In group B a similar procedure was achieved as in group A, but in additional to that He-Ne infrared laser therapy was used for several sessions. The result of radiological findings indicated that, the fracture healing occurred within group B at fifteen weeks, whereas in group A the healing occurred at eighteen weeks after operation. The implantation of autologous bone marrow enhanced the fracture healing, whereas using of combinations of autologous bone marrow and He-Ne infrared laser therapy hastened the healing.

  12. Instrumented spondylodesis in degenerative spondylolisthesis with bioactive glass and autologous bone: a prospective 11-year follow-up.

    Science.gov (United States)

    Frantzén, Janek; Rantakokko, Juho; Aro, Hannu T; Heinänen, Jyrki; Kajander, Sami; Gullichsen, Eero; Kotilainen, Esa; Lindfors, Nina C

    2011-10-01

    A prospective long-term follow-up study of bioactive glass (BAG)-S53P4 and autogenous bone (AB) used as bone graft substitutes for posterolateral spondylodesis in treatment of degenerative spondylolisthesis during 1996 to 1998 was conducted. The surgical procedure was a standardized instrumented posterolateral fusion that used USS/VAS. BAG was implanted on the left side of the fusion bed and AB on the right side. The operative outcome was evaluated on x-rays and computed tomography scans, and a clinical examination was also performed. Seventeen patients (12 women, 5 men) participated in the 11-year follow-up. The mean Oswestry Disability Index score at the follow-up was 21 (range 0 to 52), compared with 49 (range 32 to 64) at the preoperative time. A solid bony fusion was seen on computed tomography scans on the AB side in all patients and on the BAG side in 12 patients. The fusion rate of all fusion sites (n=41) for BAG as a bone substitute was 88% at the L4/5 level and 88% at the L5/S1 level. The use of BAG as a bone graft extender can be considered as a good alternative in spinal surgery in the future. PMID:21909036

  13. Bone stress injuries

    International Nuclear Information System (INIS)

    Bone stress injuries are due to cyclical overuse of the bone. They are relatively common in athletes and military recruits but also among otherwise healthy people who have recently started new or intensive physical activity. Diagnosis of bone stress injuries is based on the patient's history of increased physical activity and on imaging findings. The general symptom of a bone stress injury is stress-related pain. Bone stress injuries are difficult to diagnose based only on a clinical examination because the clinical symptoms may vary depending on the phase of the pathophysiological spectrum in the bone stress injury. Imaging studies are needed to ensure an early and exact diagnosis, because if the diagnosis is not delayed most bone stress injuries heal well without complications

  14. Determination of elemental composition of airborne dust and dust suspended in rain

    International Nuclear Information System (INIS)

    To clarify the magnitude of wash-out effect of rain on the elemental composition of airborne dust and the possible origin of the dust, the dust samples were collected with a high-volume air sampler at the JAERI-Tokai. The dust suspended in rain was also collected from rain by filtration. Up to 20 elements in both types of the dust were determined by instrumental neutron activation analysis. It was found that the elements determined could be classified into 3 groups from the elemental composition and the elemental correlation in both types of the dust samples. (author)

  15. Dust amorphization in protoplanetary disks

    CERN Document Server

    Glauser, Adrian M; Watson, Dan M; Henning, Thomas; Schegerer, Alexander A; Wolf, Sebastian; Audard, Marc; Baldovin-Saavedra, Carla

    2009-01-01

    High-energy irradiation of the circumstellar material might impact the structure and the composition of a protoplanetary disk and hence the process of planet formation. In this paper, we present a study on the possible influence of the stellar irradiation, indicated by X-ray emission, on the crystalline structure of the circumstellar dust. The dust crystallinity is measured for 42 class II T Tauri stars in the Taurus star-forming region using a decomposition fit of the 10 micron silicate feature, measured with the Spitzer IRS instrument. Since the sample includes objects with disks of various evolutionary stages, we further confine the target selection, using the age of the objects as a selection parameter. We correlate the X-ray luminosity and the X-ray hardness of the central object with the crystalline mass fraction of the circumstellar dust and find a significant anti-correlation for 20 objects within an age range of approx. 1 to 4.5 Myr. We postulate that X-rays represent the stellar activity and consequ...

  16. Wind vs. Dust Devil Streaks

    Science.gov (United States)

    2004-01-01

    22 February 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image presents a fine illustration of the difference between streaks made by dust devils and streaks made by wind gusts. Dust devils are usually solitary, spinning vortices. They resemble a tornado, or the swirling motion of a familiar, Tasmanian cartoon character. Wind gusts, on the other hand, can cover a larger area and affect more terrain at the same time. The dark, straight, and parallel features resembling scrape marks near the right/center of this image are thought to have been formed by a singular gust of wind, whereas the more haphazard dark streaks that crisscross the scene were formed by dozens of individual dust devils, acting at different times. This southern summer image is located in Noachis Terra near 67.0oS, 316.2oW. Sunlight illuminates the scene from the upper left; the picture covers an area 3 km (1.9 mi) wide.

  17. On Multifractal of Cantor Dust

    Institute of Scientific and Technical Information of China (English)

    In-Soo BAEK

    2009-01-01

    We consider quasi-self-similar measures with respect to all real numbers on a Cantor dust.We define a local index function on the real numbers for each quasi-self-similar measure at each point in a Cantor dust.The value of the local index function at the real number zero for all the quasi-self-similar measures at each point is the weak local dimension of the point.We also define transformed measures of a quasi-self-similar measure which are closely related to the local index function.We compute the local dimensions of transformed measures of a quasi-self-similar measure to find the multifractal spectrum of the quasi-self-similar measure.Furthermore we give an essential example for the theorem of local dimension of transformed measure.In fact,our result is an ultimate generalization of that of a selfsimilar measure on a self-similar Cantor set.Furthermore the results also explain the recent results about weak local dimensions on a Cantor dust.

  18. Physical properties of suspended dust in Iceland

    Science.gov (United States)

    Dagsson Waldhauserova, Pavla; Olafsson, Haraldur; Arnalds, Olafur; Skrabalova, Lenka; Sigurdardottir, Gudmunda; Branis, Martin; Hladil, Jindrich; Chadimova, Leona; Skala, Roman; Navratil, Tomas; Menar, Sibylle von Lowis of; Thorsteinsson, Throstur

    2014-05-01

    Atmospheric Dust Measurements (ADMI 2013) of one of the most active dust sources in Iceland (Mælifellsandur) were conducted during season with high precipitation on August 8th-18th, 2013. We measured mass concentrations (PM2.5 and PM10), particle size distributions in size range 0.3-10μm and number concentrations during rather small dust event. Dust samples of the event were analyzed (morpho-textural observations, optical and scanning-electron microscopy). Two TSI 8520 DustTrak Aerosol Monitors (light-scattering laser photometers that measure aerosol mass concentrations in range 0.001 to 100 mg/m3) and one TSI Optical Particle Sizer (OPS) 3330 (optical scattering from single particle up to 16 different channels - 0.3 to 10 μm - measuring particle size distribution) were used. We measured a dust event which occurred during wet and low wind/windless conditions as result of surface heating in August 2013. Maximum particle number concentration (PM~0.3-10 µm) reached 149954 particles cm-3 min-1 while mass concentration (PMshards with bubbles and 80 % of the particulate matter is volcanic glass rich in heavy metals. Wet dust particles were mobilized within < 4 hours. Here we introduced a comprehensive study on physical properties of the Icelandic dust aerosol and the first scientific study of particle size distributions in an Icelandic dust event including findings on initiation of dust suspension.

  19. Metal Dusting-Mechanisms and Preventions

    Institute of Scientific and Technical Information of China (English)

    J.Q.ZHANG; D.J.YOUNG

    2009-01-01

    Metal dusting attacks iron, low and high alloy steels and nickel-or cobalt-base alloys by disintegrating bulk metals and alloys into metal particles in a coke deposit. It occurs in strongly carburising gas atmospheres (carbon activity aC>1) at elevated temperatures (400℃~1000℃). This phenomenon has been studied for decades, but the detailed mechanism is still not well understood. Current methods of protection against metal dusting are either directed to the process conditions-temperature and gas composition-or to the development of a dense adherent oxide layer on the surface of the alloy by selective oxidation. However, metal dusting still occurs by carbon dissolving in the base metal via defects in the oxide scale. The research work at UNSW is aimed at determining the detailed mechanism of metal dusting of both ferritic and austenitic alloys, in particular the microprocesses of graphite deposition, nanoparticle formation and underlying metal destruction. This work was carried out using surface observation, cross-section analysis by focused ion beam and electron microscopic examination of coke deposits at different stages of the reaction. It was found that surface orientation affected carbon deposition and metal dusting at the initial stage of the reaction. Metal dusting occurred only when graphite grew into the metal interior where the volume expansion is responsible for metal disintegration and dusting. It was also found that the metal dusting process could be significantly changed by alterations in alloy chemistry. Germanium was found to affect the iron dusting process by destabilising FeC but increasing the rate of carbon deposition and dusting, which questions the role of cementite in ferritic alloy dusting. Whilst adding copper to iron did not change the carburisation kinetics, cementite formation and coke morphology, copper alloying reduced nickel and nickel-base alloy dusting rates significantly. Application of these fundamental results to the dusting

  20. Aerosol optical absorption by dust and black carbon in Taklimakan Desert, during no-dust and dust-storm conditions

    Institute of Scientific and Technical Information of China (English)

    Hui Lu; Wenshou Wei; Mingzhe Liu; Weidong Gao; Xi Han

    2012-01-01

    Aerosol absorption coefficient σap involves the additive contribution of both black carbon aerosol (BC) and dust aerosol.The linear statistical regression analysis approach introduced by Fialho et al.(2005) is used to estimate the absorption exponents of BC and dust aerosol absorption coefficients,and further to separate the contributions of these two types of aerosols from the total light absorption coefficient measured in the hinterland of Taklimakan Desert in the spring of 2006.Absorption coefficients are measured by means of a 7-wavelength Aethalometer from 1 March to 31 May and from 1 November to 28 December,2006.The absorption exponent of BC absorption coefficient α is estimated as (-0.95 ±0.002) under background weather (supposing the observed absorption coefficient is due only to BC); the estimated absorption exponent of dust aerosol absorption coefficient β during the 6 dust storm periods (strong dust storm) is (-2.55 ± 0.009).Decoupling analysis of the measured light absorption coefficients demonstrates that,on average,the light absorptions caused by dust aerosol and BC make up about 50.5% and 49.5% respectively of the total light absorption at 520 nm; during dust weather process periods (dust storm,floating dust,blowing dust),the contribution of dust aerosol to absorption extinction is 60.6% on average; in the hinterland of desert in spring,dust aerosol is also the major contributor to the total aerosol light absorption,more than that of black carbon aerosol.

  1. A Fractal Model for the Capacitance of Lunar Dust and Lunar Dust Aggregates

    Science.gov (United States)

    Collier, Michael R.; Stubbs, Timothy J.; Keller, John W.; Farrell, William M.; Marshall, John; Richard, Denis Thomas

    2011-01-01

    Lunar dust grains and dust aggregates exhibit clumping, with an uneven mass distribution, as well as features that span many spatial scales. It has been observed that these aggregates display an almost fractal repetition of geometry with scale. Furthermore, lunar dust grains typically have sharp protrusions and jagged features that result from the lack of aeolian weathering (as opposed to space weathering) on the Moon. A perfectly spherical geometry, frequently used as a model for lunar dust grains, has none of these characteristics (although a sphere may be a reasonable proxy for the very smallest grains and some glasses). We present a fractal model for a lunar dust grain or aggregate of grains that reproduces (1) the irregular clumpy nature of lunar dust, (2) the presence of sharp points, and (3) dust features that span multiple scale lengths. We calculate the capacitance of the fractal lunar dust analytically assuming fixed dust mass (i.e. volume) for an arbitrary number of fractal levels and compare the capacitance to that of a non-fractal object with the same volume, surface area, and characteristic width. The fractal capacitance is larger than that of the equivalent non-fractal object suggesting that for a given potential, electrostatic forces on lunar dust grains and aggregates are greater than one might infer from assuming dust grains are sphericaL Consequently, electrostatic transport of lunar dust grains, for example lofting, appears more plausible than might be inferred by calculations based on less realistic assumptions about dust shape and associated capacitance.

  2. House dust in seven Danish offices

    Science.gov (United States)

    Mølhave, L.; Schneider, T.; Kjærgaard, S. K.; Larsen, L.; Norn, S.; Jørgensen, O.

    Floor dust from Danish offices was collected and analyzed. The dust was to be used in an exposure experiment. The dust was analyzed to show the composition of the dust which can be a source of airborne dust indoors. About 11 kg of dust from vacuum cleaner bags from seven Danish office buildings with about 1047 occupants (12 751 m 2) was processed according to a standardized procedure yielding 5.5 kg of processed bulk dust. The bulk dust contained 130.000-160.000 CFU g -1 microorganisms and 71.000-90.000 CFU g -1 microfungi. The content of culturable microfungi was 65-123 CFU 30 g -1 dust. The content of endotoxins ranged from 5.06-7.24 EU g -1 (1.45 ng g -1 to 1.01 ng g -1). Allergens (ng g -1) were from 147-159 (Mite), 395-746 (dog) and 103-330 (cat). The macro molecular organic compounds (the MOD-content) varied from 7.8-9.8 mg g -1. The threshold of release of histamine from basophil leukocytes provoked by the bulk dust was between 0.3 and 1.0 mg ml -1. The water content was 2% (WGT) and the organic fraction 33%. 6.5-5.9% (dry) was water soluble. The fiber content was less than 0.2-1.5% (WGT) and the desorbable VOCs was 176-319 μg g -1. Most of the VOC were aldehydes. However, softeners for plastic (DBP and DEHP) were present. The chemical composition includes human and animal skin fragments, paper fibers, glass wool, wood and textilefibers and inorganic and metal particles. The sizes ranged from 0.001-1 mm and the average specific density was 1.0 g m -3. The bulk dust was resuspended and injected into an exposure chamber. The airborne dust was sampled and analyzed to illustrate the exposures that can result from sedimented dirt and dust. The airborne dust resulting from the bulk dust reached concentrations ranging from 0.26-0.75 mg m -3 in average contained 300-170 CFU m -3. The organic fraction was from 55-70% and the water content about 2.5% (WGT). The content of the dust was compared to the similar results reported in the literature and its toxic potency is

  3. Dust observations at orbital altitudes surrounding Mars

    Science.gov (United States)

    Andersson, L.; Weber, T. D.; Malaspina, D.; Crary, F.; Ergun, R. E.; Delory, G. T.; Fowler, C. M.; Morooka, M. W.; McEnulty, T.; Eriksson, A. I.; Andrews, D. J.; Horanyi, M.; Collette, A.; Yelle, R.; Jakosky, B. M.

    2015-11-01

    Dust is common close to the martian surface, but no known process can lift appreciable concentrations of particles to altitudes above ~150 kilometers. We present observations of dust at altitudes ranging from 150 to above 1000 kilometers by the Langmuir Probe and Wave instrument on the Mars Atmosphere and Volatile Evolution spacecraft. Based on its distribution, we interpret this dust to be interplanetary in origin. A comparison with laboratory measurements indicates that the dust grain size ranges from 1 to 12 micrometers, assuming a typical grain velocity of ~18 kilometers per second. These direct observations of dust entering the martian atmosphere improve our understanding of the sources, sinks, and transport of interplanetary dust throughout the inner solar system and the associated impacts on Mars’s atmosphere.

  4. Linear Alkylbenzenesulfonates in indoor Floor Dust

    DEFF Research Database (Denmark)

    Wolkoff, Peder; Madsen, Jørgen Øgaard

    1999-01-01

    The amount of Linear Alkylbenzenesulfonates (LAS) in the particle fraction of floor dust sampled from 7 selected public buildings varied between 34 and 1500 microgram per gram dust, while the contents of the fibre fractions generally were higher with up to 3500 microgram LAS/g dust. The use of a...... cleaning agent with LAS resulted in an increase of the amount of LAS in the floor dust after floor wash relative to just before floor wash. However, the most important source of LAS in the indoor floor dust appears to be residues of detergent in clothing. Thus, a newly washed shirt contained 2960 microgram...... LAS/g. The analysis of the office dust samples indicated that LAS (and probably other tensides) might be of importance for the indoor environment. However, more knowledge is required about how low concentrations of surface-active agents in combination with other compounds may affect the eye tear film...

  5. Lunar Dust and Dusty Plasma Physics

    Science.gov (United States)

    Wilson, Thomas L.

    2009-01-01

    In the plasma and radiation environment of space, small dust grains from the Moon s surface can become charged. This has the consequence that their motion is determined by electromagnetic as well as gravitational forces. The result is a plasma-like condition known as "dusty plasmas" with the consequence that lunar dust can migrate and be transported by magnetic, electric, and gravitational fields into places where heavier, neutral debris cannot. Dust on the Moon can exhibit unusual behavior, being accelerated into orbit by electrostatic surface potentials as blow-off dust, or being swept away by moving magnetic fields like the solar wind as pick-up dust. Hence, lunar dust must necessarily be treated as a dusty plasma subject to the physics of magnetohydrodynamics (MHD). A review of this subject has been given before [1], but a synopsis will be presented here to make it more readily available for lunar scientists.

  6. Dust observations at orbital altitudes surrounding Mars.

    Science.gov (United States)

    Andersson, L; Weber, T D; Malaspina, D; Crary, F; Ergun, R E; Delory, G T; Fowler, C M; Morooka, M W; McEnulty, T; Eriksson, A I; Andrews, D J; Horanyi, M; Collette, A; Yelle, R; Jakosky, B M

    2015-11-01

    Dust is common close to the martian surface, but no known process can lift appreciable concentrations of particles to altitudes above ~150 kilometers. We present observations of dust at altitudes ranging from 150 to above 1000 kilometers by the Langmuir Probe and Wave instrument on the Mars Atmosphere and Volatile Evolution spacecraft. Based on its distribution, we interpret this dust to be interplanetary in origin. A comparison with laboratory measurements indicates that the dust grain size ranges from 1 to 12 micrometers, assuming a typical grain velocity of ~18 kilometers per second. These direct observations of dust entering the martian atmosphere improve our understanding of the sources, sinks, and transport of interplanetary dust throughout the inner solar system and the associated impacts on Mars's atmosphere. PMID:26542578

  7. Dust Emissivity Variations In the Milky Way

    OpenAIRE

    Paradis, D.; Bernard, J. -Ph.; Meny, C.

    2009-01-01

    Aims. Dust properties appear to vary according to the environment in which the dust evolves. Previous observational indications of these variations in the far-infrared (FIR) and submillimeter (submm) spectral range are scarce and limited to specific regions of the sky. To determine whether these results can be generalised to larger scales, we study the evolution in dust emissivities from the FIR to millimeter (mm) wavelengths, in the atomic and molecular interstellar medium (ISM), along the G...

  8. Semiclassical collapse of a sphere of dust

    OpenAIRE

    Roberto CasadioDepartment of Physics University of Bologna and Istituto Nazionale di Fisica Nucleare, Sezione di Bologna; Giovanni Venturi(Department of Physics, University of Bologna, and Istituto Nazionale di Fisica Nucleare, Sezione di Bologna, Italy)

    2015-01-01

    The semiclassical collapse of a homogeneous sphere of dust is studied. After identifying the independent dynamical variables, the system is canonically quantised and coupled equations describing matter (dust) and gravitation are obtained. The conditions for the validity of the adiabatic (Born--Oppenheimer) and semiclassical approximations are derived. Further on neglecting back--reaction effects, it is shown that in the vicinity of the horizon and inside the dust the Wightman function for a c...

  9. CRADE OF SAND AND DUST STORM WEATHER

    Institute of Scientific and Technical Information of China (English)

    Niu Ruoyun; Tian Cuiying; Bi Baogui; Yang Keming; Wang Youheng; Tuo Ya; Ding Haifang; Zhang Tairen

    2011-01-01

    Background Sand and dust storm,as one of the main disastrous weathers that affect northern China,not only affect the people health and normal life,but cause the short-term climatic changes due to the direct and indirect radiation of the earth-atmosphere system through the dust floating in the sky.The sand end dust weather and its potential harm on the national economy,ecological environment,social activities and other aspects have aroused worldwide concern.

  10. Autogenous Fat Transplantation for Facial Depression%自体颗粒脂肪注射移植充填面部软组织凹陷

    Institute of Scientific and Technical Information of China (English)

    周同葵; 巩梦童; 贺小虎

    2011-01-01

    目的 探讨自体颗粒脂肪注射移植充填矫治面部凹陷的临床应用.方法 标记面部凹陷部位,估计需要填充的脂肪量,取臀部或大腿部为供区.在肿胀麻醉下,用20ml注射器吸脂,吸管采用3.0mm的钝头吸管,负压应控制在20ml注射器内3~5ml左右真空.抽取脂肪颗粒,无菌状况下将所获脂肪颗粒洗去血迹、破碎脂肪细胞和脂滴,反复漂洗,至漂洗液色清透明;静置、分层后取中层饱满的脂肪颗粒注射在面部凹陷部位.结果采用自体脂肪颗粒移植充填矫正面部凹陷26例,其中6例患者经过了3次注射充填;12例患者经过了2次注射充填;8例患者经过了1次注射充填,均获良好效果.结论 利用自体脂肪移植充填矫治面部凹陷,创伤小、并发症低、手术效果明显,相对现有其他治疗方法,是一种较为理想的治疗方法 .%Objective To discuss clinical effect of autogenous fat transplantation on facial depressions. Methods The areas of facial sag were marked and the amount of fat that to be filled was estimated. Fat granulation was harvested from abdomen or thighs with tumescent anaesthesia technique. Ljposuction was performed by using 20 ml syringe with 3.0 mm suction tube,and the special negative pressure was kept (about 3-5 ml vacuum in a 20 mL syringe). The extracted fat granulation was washed to remove the blood,breaking fat cells and lipid drops under sterile conditions until the lotions gets clear. After a standing and layering process,the full fat particles at the middle layer were collected and injected in the site of facial depression. Results Total of 26 cases underwent the autogenous fat transplantation on facial depressions. 6 cases had received 3 times of injections; 12 cases received 2 times of injections ;8 cases received 1 time of injection. The good results were achieved in all cases. Conclusion The autogenous fat'transplantation, with a less invasion,few complications and obviously

  11. Propagation of dust-acoustic waves in weakly ionized plasmas with dust-charge fluctuation

    Indian Academy of Sciences (India)

    K K Mondal

    2004-11-01

    For an unmagnetized partially ionized dusty plasma containing electrons, singly charged positive ions, micron-sized massive negatively charged dust grains and a fraction of neutral atoms, dispersion relations for both the dust-ion-acoustic and the dust-acoustic waves have been derived, incorporating dust charge fluctuation. The dispersion relations, under various conditions, have been exhaustively analysed. The explicit expressions for the growth rates have also been derived.

  12. Rocket dust storms and detached dust layers in the Martian atmosphere

    Science.gov (United States)

    Spiga, Aymeric; Faure, Julien; Madeleine, Jean-Baptiste; Määttänen, Anni; Forget, François

    2013-04-01

    Airborne dust is the main climatic agent in the Martian environment. Local dust storms play a key role in the dust cycle; yet their life cycle is poorly known. Here we use mesoscale modeling that includes the transport of radiatively active dust to predict the evolution of a local dust storm monitored by OMEGA on board Mars Express. We show that the evolution of this dust storm is governed by deep convective motions. The supply of convective energy is provided by the absorption of incoming sunlight by dust particles, rather than by latent heating as in moist convection on Earth. We propose to use the terminology "rocket dust storm," or conio-cumulonimbus, to describe those storms in which rapid and efficient vertical transport takes place, injecting dust particles at high altitudes in the Martian troposphere (30-50 km). Combined to horizontal transport by large-scale winds, rocket dust storms produce detached layers of dust reminiscent of those observed with Mars Global Surveyor and Mars Reconnaissance Orbiter. Since nighttime sedimentation is less efficient than daytime convective transport, and the detached dust layers can convect during the daytime, these layers can be stable for several days. The peak activity of rocket dust storms is expected in low-latitude regions at clear seasons (late northern winter to late northern summer), which accounts for the high-altitude tropical dust maxima unveiled by Mars Climate Sounder. Dust-driven deep convection has strong implications for the Martian dust cycle, thermal structure, atmospheric dynamics, cloud microphysics, chemistry, and robotic and human exploration.

  13. Saharan dust storms: nature and consequences

    Science.gov (United States)

    Goudie, A. S.; Middleton, N. J.

    2001-12-01

    This paper reviews recent work on the role of Saharan dust in environmental change, the location and strength of source areas, the transport paths of material away from the desert, the rates of Saharan dust deposition, the nature of that material (including PeriSaharan loess) and the changing rates of dust activity in response to long and short-term climatic changes. The Sahara produces more aeolian soil dust than any other world desert, and Saharan dust has an important impact on climatic processes, nutrient cycles, soil formation and sediment cycles. These influences spread far beyond Africa, thanks to the great distances over which Saharan dust is transported. The precise locations of Saharan dust source areas are not well known, but data from the Total Ozone Mapping Spectrometer (TOMS) suggest two major source areas: the Bodélé depression and an area covering eastern Mauritania, western Mali and southern Algeria. Trajectories of long-distance transport are relatively well documented, but the links between source areas and seasonal Saharan dust pathways are not. However, it is possible that Harmattan dust from the Bodélé depression may not be the source of the prominent winter plume over the tropical North Atlantic, as is often suggested in the literature. Few of the data on particle size characteristics of Saharan dust are derived from major source areas or from Africa itself. Saharan dusts sampled from the Harmattan plume and over Europe are dominated by SiO 2 and Al 2O 3, a characteristic they share with North American and Chinese dusts. The concentrations of these two major elements are similar to those found in world rocks. PeriSaharan loess is conspicuous by its relative absence, considering the Sahara's dominance of the global desert dust cycle both in the contemporary era and through the geological past. In recent decades, the frequency of Saharan dust events has varied markedly in response to climatic factors such as drought and anthropogenic

  14. Global Dust Budgets of the Magellanic Clouds

    Science.gov (United States)

    Matsuura, Mikako

    2013-03-01

    Within galaxies, gas and dust are constantly exchanged between stars and the interstellar medium (ISM). The life-cycle of gas and dust is the key to the evolution of galaxies. Despite its importance, it is has been very difficult to trace the life-cycle of gas and dust via observations. The Spitzer Space Telescope and Herschel Space Observatory have provided a great opportunity to study the life-cycle of the gas and dust in very nearby galaxies, the Magellanic Clouds. AGB stars are more important contributors to the dust budget in the Large Magellanic Cloud (LMC), while in the Small Magellanic Cloud (SMC), SNe are dominant. However, it seems that the current estimates of the total dust production from AGB stars is insufficient to account for dust present in the ISM. Other dust sources are needed, and supernovae are promising sources. Alternatively the time scale of dust lifetime itself needs some revisions, potentially because they could be unevenly distributed in the ISM or clumps.

  15. Limits on Intergalactic Dust During Reionization

    CERN Document Server

    Imara, Nia

    2015-01-01

    In this Letter, we constrain the dust-to-gas ratio in the intergalactic medium (IGM) at high redshifts. We employ models for dust in the local Universe to contrain the dust-to-gas ratio during the epoch of reionization at redshifts z ~ 6-10. The observed level of reddening of high redshift galaxies implies that the IGM was enriched to an intergalactic dust-to-gas ratio of less than 3% of the Milky Way value by a redshift of z=10.

  16. Halo dust detection around NGC 891

    CERN Document Server

    Bocchio, M; Hunt, L K; Schneider, R

    2015-01-01

    Observations of edge-on galaxies allow us to investigate the vertical extent and properties of dust, gas and stellar distributions. NGC 891 has been studied for decades and represents one of the best studied cases of an edge-on galaxy. We use deep PACS data together with IRAC, MIPS and SPIRE data to study the vertical extent of dust emission around NGC 891. We also test the presence of a more extended, thick dust component. By performing a convolution of an intrinsic vertical profile emission with each instrument PSF and comparing it with observations we derived the scaleheight of a thin and thick dust disc component. For all wavelengths considered the emission is best fit with the sum of a thin and a thick dust component. The scaleheight of both dust components shows a gradient passing from 70 $\\mu$m to 250 $\\mu$m. This could be due to a drop in dust heating (and thus dust temperature) with the distance from the plane, or to a sizable contribution ($\\sim 15 - 80%$) of an unresolved thin disc of hotter dust t...

  17. Bone tumors: Nursing care

    International Nuclear Information System (INIS)

    Bone tumors represent approximately 5% of childhood malignancies. osteosarcoma is the primary malignant bone tumor, accounting for 60% of cancer with peak incidence in the 2nd decade of life. Ewing's sarcoma is the second most common bone cancer with peak at a slightly younger age. This presentation discusses similarities and differences in the diagnosis and treatment of these two malignancies. Diagnostic procedures include plain radiographs, CT and MRI of the primary site, plain x-ray and CT of the chest, bone scan, and biopsy of the primary tumor. For patients diagnosed with Ewing's sarcoma, a bone marrow aspirate and biopsy will also be required. Our current approach to the treatment of bone tumors includes preoperative combination chemotherapy and en bloc surgical removal of the tumor followed by postoperative chemotherapy. In the case of Ewing's sarcoma, radiation therapy may be employed in addition to surgery, if margins are questionable of instead of surgery, if the tumor is not resectable

  18. Biophotonics and Bone Biology

    Science.gov (United States)

    Zimmerli, Gregory; Fischer, David; Asipauskas, Marius; Chauhan, Chirag; Compitello, Nicole; Burke, Jamie; Tate, Melissa Knothe

    2004-01-01

    One of the more-serious side effects of extended space flight is an accelerated bone loss [Bioastronautics Critical Path Roadmap, http://research.hq.nasa.gov/code_u/bcpr/index.cfm]. Rates of bone loss are highest in the weight-bearing bones of the hip and spine regions, and the average rate of bone loss as measured by bone mineral density measurements is around 1.2% per month for persons in a microgravity environment. It shows that an extrapolation of the microgravity induced bone loss rates to longer time scales, such as a 2.5 year round-trip to Mars (6 months out at 0 g, 1.5 year stay on Mars at 0.38 g, 6 months back at 0 g), could severely compromise the skeletal system of such a person.

  19. The Maxillary Sinus Membrane Elevation Procedure: Augmentation of Bone around Dental Implants without Grafts—A Review of a Surgical Technique

    Directory of Open Access Journals (Sweden)

    Christopher Riben

    2012-01-01

    Full Text Available Background. Long-term edentulism may in many cases result in resorption of the alveolar process. The sinus lift procedure aims to create increased bone volume in the maxillary sinus in order to enable installation of dental implants in the region. The method is over 30 years old, and initially autogenous bone grafts were used and later also different bone substitutes. Since 1997, a limited number of studies have explored the possibility of a graftless procedure where the void under the sinus membrane is filled with a blood clot that enables bone formation. Aim. To describe the evolution of the sinus-lift technique and to review the literature related to the technique with a focus on long-term studies related to the graft-less technique. Methods. The electronic database PubMed was searched, and a systematic review was conducted regarding relevant articles. Results. A relatively few long-term studies using the described technique were found. However, the technique was described as reliable considering the outcome of the existing studies. Conclusion. All investigated studies show high implant survival rates for the graftless technique. The technique is considered to be cost-effective, less time-consuming, and related to lower morbidity since no bone harvesting is needed.

  20. Treatment of an open distal tibia fracture with segmental bone loss in combination with a closed proximal tibia fracture: a case report.

    Science.gov (United States)

    Park, Jin; Yang, Kyu Hyun

    2012-08-01

    The treatment of open distal tibia fractures remains challenging, particularly when the fracture is infected and involves segmental bone loss. We report the case of a 38-year-old man who sustained an open distal tibiofibular fracture with segmental bone loss and a closed proximal tibial fracture. The fractures were initially fixed with a temporary external fixator. The open distal tibial fracture was infected, and the skin was covered after the wound became culture negative. The tibia was then internally transported with a ring external fixator; the closed fracture of the proximal tibia served as the corticotomy for internal transport without conventional corticotomy. After 5 cm internal transport, the docking site of the distal tibia was fixed with a locking plate and autogenous cancellous bone graft. Bone graft was also used to the distal tibiofibular space to achieve distal tibiofibular synostosis. We describe one treatment option for an infected open fracture of the distal tibia with segmental bone loss that is accompanied by a closed fracture of the proximal tibia. This method can treat two fractures simultaneously. PMID:22526200

  1. Bone fractures after menopause

    OpenAIRE

    Barlow, David H.; Bouchard, Philippe; Brandi, Maria Luisa; Evers, J.L.H.; Glasier, A.; Negri, Eva; Papapoulos, Socrates E; Ralston, Stuart H; Rizzoli, Rene; Baird, D T; Collins, J.; G. Benagiano; P.G. Crosignani; La Vecchia, C.; Volpe, A

    2010-01-01

    Every year 30% of individuals above age 65 fall, and falls are the principal cause of bone fractures. To reduce fracture incidence requires both prevention of falls and maintenance of bone strength.PubMed searches were performed, for studies of the epidemiology of fractures, bone physiology, endocrine effects, osteoporosis measurement, genetics, prevention and effectiveness. Topic summaries were presented to the Workshop Group and omissions or disagreements were resolved by discussion.Ageing ...

  2. Bone Regeneration in Odontostomatology

    OpenAIRE

    Tonelli, P; Duvina, M.; Brancato, L.; Delle Rose, G.; Biondi, E.; Civitelli, V.

    2010-01-01

    Maxillary edentulism, together with periodontal disease, is the condition that most frequently induces disruption of alveolar bone tissue. Indeed, the stimulus of the periodontal ligament is lost and the local bone tissue becomes subject to resorption processes that, in the six months following the loss of the tooth, result in alveolar defects or more extensive maxillary atrophy. In both cases, loss of vestibular cortical bone is followed by reduction in the vertical dimension of the alveolar...

  3. Percutaneous Bone Tumor Management

    OpenAIRE

    Gangi, Afshin; Buy, Xavier

    2010-01-01

    Interventional radiology plays a major role in the management of bone tumors. Many different percutaneous techniques are available. Some aim to treat pain and consolidate a pathological bone (cementoplasty); others aim to ablate tumor or reduce its volume (sclerotherapy, thermal ablation). In this article, image-guided techniques of primary and secondary bone tumors with vertebroplasty, ethanol injection, radiofrequency ablation, laser photocoagulation, cryoablation, and radiofrequency ioniza...

  4. Effect of nonthermal ion distribution and dust temperature on nonlinear dust-acoustic solitary waves

    Indian Academy of Sciences (India)

    K Annou; R Annou

    2012-01-01

    Dust-acoustic solitary waves in unmagnetized dusty plasma whose constituents are inertial charged dust grains, Boltzmannian electrons and nonthermal ions have been investigated by taking into account finite dust temperature. The pseudopotential has been used to study solitary solution. The existence of solitary waves having negative potential is reported.

  5. THE MAIN CULPRIT IN ALLERGIC RHINITIS - HOUSE DUST OR HOUSE DUST MITE

    OpenAIRE

    Abhey

    2015-01-01

    Allergic rhinitis especially perennial type makes life miserable for the patient. House dust mite is one of the major players causing it. This study is to compare the allergen i n city of house dust mite versus house dust and evaluate any cross - allergenicity between them. STUDY DESIGN: Prospective study in a tertiary referral ...

  6. THE MAIN CULPRIT IN ALLERGIC RHINITIS - HOUSE DUST OR HOUSE DUST MITE

    Directory of Open Access Journals (Sweden)

    Abhey

    2015-10-01

    Full Text Available Allergic rhinitis especially perennial type makes life miserable for the patient. House dust mite is one of the major players causing it. This study is to compare the allergen i n city of house dust mite versus house dust and evaluate any cross - allergenicity between them. STUDY DESIGN: Prospective study in a tertiary referral hospital. MATERIALS & METHODS: Forty patients of allergic rhinitis and well matched controls were subjected to intradermal skin tests to house dust and house dust mite allergen. The skin tests were graded as per standard norms and the responses matched after correlating with different parameters. Statistical analysis was done and the results evaluated. RESULTS: House dust mite was the main allergen, as compared to house dust, responsible for causing allergic rhinitis. The allergen reactivity potential of house dust mite was significantly more as compared to house dust. And, as such there was no statistically significant cross - allergenicity between the two groups. CONCLUSION: House dust mite rather than house dust is the main culprit in causing allergic rhinitis. Hence, precautionary and preventive measures to control the exposure to house dust mite can be undertaken

  7. Mathematical model of dust cleaning process in centrifugal-inertial dust collector

    OpenAIRE

    Batluk, V.; Paranyak, N.; Makarchuk, V.

    2013-01-01

    The article is devoted to the problem of providing air cleaning from dust in various industries, using highly efficient apparatus, with the aim of bringing the volume of harmful emissions to the sanitary standards. The article presents new directions in creating of dust cleaning apparatus, based on the usage of centrifugal, inertial forces, by which the efficiency of dust collection could be significantly increased.

  8. Dust-regulated galaxy formation and evolution: a new chemodynamical model with live dust particles

    Science.gov (United States)

    Bekki, Kenji

    2015-05-01

    Interstellar dust plays decisive roles in the conversion of neutral to molecular hydrogen (H2), the thermodynamical evolution of interstellar medium (ISM), and the modification of spectral energy distributions (SEDs) of galaxies. These important roles of dust have not been self-consistently included in previous numerical simulations of galaxy formation and evolution. We have therefore developed a new model by which one can investigate whether and how galaxy formation and evolution can be influenced by dust-related physical processes such as photoelectric heating, H2 formation on dust, and stellar radiation pressure on dust in detail. A novel point of the model is that different dust species in a galaxy are represented by `live dust' particles (i.e. not test particles). Therefore, dust particles in a galaxy not only interact gravitationally with all four components of the galaxy (i.e. dark matter, stars, gas, and dust) but also are grown and destroyed through physical processes of ISM. First, we describe a way to include dust-related physical processes in N-body+hydrodynamical simulations of galaxy evolution in detail. Then, we show some preliminary results of dust-regulated galaxy evolution. The preliminary results suggest that the evolution of dust distributions driven by radiation pressure of stars is very important for the evolution of star formation rates, chemical abundances, H2 fractions, and gas distributions in galaxies.

  9. Modelling Martian dust storms: feedbacks between dust and atmospheric circulation at a hierarchy of scales

    OpenAIRE

    Lewis, S.; Spiga, A.; Mulholland, D.

    2010-01-01

    We employ numerical models of Mars at spatial scales ranging from global to a few metres in order to investigate both the impact of increasing dust loading on atmospheric circulations and the role of different atmospheric circulation components on dust lifting, transport and on dust storm decay.

  10. Application observation of autogenous broad fascia in eye surgery%自体阔筋膜在眼科手术中的应用观察

    Institute of Scientific and Technical Information of China (English)

    卿方强

    2015-01-01

    目的:探讨自体阔筋膜在眼科手术中应用的临床可行性。方法:2005年—2013年根据不同的适应症和治疗目的,将阔筋膜作为悬吊材料、填充材料或修补材料等应用于多种眼部手术中,并观察效果。结果:本组18例21眼阔筋膜移植病例,术后无一例出现感染、排斥反应,可直接观察到的阔筋膜组织未见吸收、脱落或坏死。结论:自体阔筋膜效果持久,生物耐受较好,抗感染能力强,无论是作为上睑下垂、睑外翻手术治疗中的理想的悬吊材料,还是作为巩膜、韧带或肌腱的力学支撑和替代材料,阔筋膜均为很好的选择。%ObjectiveTo investigate the clinical feasibility of using autogenous lata in ophthalmologic operation.Methods From 2005 to 2013, according to the different indications and therapeutic purposes, the fascia lata as suspension material, filling material or repair materials, applied to a variety of eye operation, and observe the effect.Results18 broad fascia transplantation cases, there was no postoperative infection and rejection, can be directly observed, wide fascia tissue did not see absorption and loss or necrosis.Conclusion Autogenous broad fascia effect lasting, biological resistance is good, strong ability to fight infection. Both as a ptosis and ectropion surgery treatment of suspension material, or as support materials, sclera and ligaments and tendons broad ,fascia is a good choice.

  11. Desert dust satellite retrieval intercomparison

    Directory of Open Access Journals (Sweden)

    E. Carboni

    2012-01-01

    Full Text Available This work provides a comparison of satellite retrievals of Saharan desert dust aerosol optical depth (AOD during a strong dust event through March 2006. In this event, a large dust plume was transported over desert, vegetated, and ocean surfaces. The aim is to identify and understand the differences between current algorithms, and hence improve future retrieval algorithms. The satellite instruments considered are AATSR, AIRS, MERIS, MISR, MODIS, OMI, POLDER, and SEVIRI. An interesting aspect is that the different algorithms make use of different instrument characteristics to obtain retrievals over bright surfaces. These include multi-angle approaches (MISR, AATSR, polarisation measurements (POLDER, single-view approaches using solar wavelengths (OMI, MODIS, and the thermal infrared spectral region (SEVIRI, AIRS. Differences between instruments, together with the comparison of different retrieval algorithms applied to measurements from the same instrument, provide a unique insight into the performance and characteristics of the various techniques employed. As well as the intercomparison between different satellite products, the AODs have also been compared to co-located AERONET data. Despite the fact that the agreement between satellite and AERONET AODs is reasonably good for all of the datasets, there are significant differences between them when compared to each other, especially over land. These differences are partially due to differences in the algorithms, such as assumptions about aerosol model and surface properties. However, in this comparison of spatially and temporally averaged data, at least as significant as these differences are sampling issues related to the actual footprint of each instrument on the heterogeneous aerosol field, cloud identification and the quality control flags of each dataset.

  12. Imaging of Bone Marrow.

    Science.gov (United States)

    Lin, Sopo; Ouyang, Tao; Kanekar, Sangam

    2016-08-01

    Bone marrow is the essential for function of hematopoiesis, which is vital for the normal functioning of the body. Bone marrow disorders or dysfunctions may be evaluated by blood workup, peripheral smears, marrow biopsy, plain radiographs, computed tomography (CT), MRI and nuclear medicine scan. It is important to distinguish normal spinal marrow from pathology to avoid missing a pathology or misinterpreting normal changes, either of which may result in further testing and increased health care costs. This article focuses on the diffuse bone marrow pathologies, because the majority of the bone marrow pathologies related to hematologic disorders are diffuse. PMID:27444005

  13. Biophotonics and Bone Biology

    Science.gov (United States)

    Zimmerli, Gregory; Fischer, David; Asipauskas, Marius; Chauhan, Chirag; Compitello, Nicole; Burke, Jamie; Tate, Melissa Knothe

    2004-01-01

    One of the more serious side effects of extended space flight is an accelerated bone loss. Rates of bone loss are highest in the weight-bearing bones of the hip and spine regions, and the average rate of bone loss as measured by bone mineral density measurements is around 1.2% per month for persons in a microgravity environment. It is well known that bone remodeling responds to mechanical forces. We are developing two-photon microscopy techniques to study bone tissue and bone cell cultures to better understand the fundamental response mechanism in bone remodeling. Osteoblast and osteoclast cell cultures are being studied, and the goal is to use molecular biology techniques in conjunction with Fluorescence Lifetime Imaging Microscopy (FLIM) to study the physiology of in-vitro cell cultures in response to various stimuli, such as fluid flow induced shear stress and mechanical stress. We have constructed a two-photon fluorescence microscope for these studies, and are currently incorporating FLIM detection. Current progress will be reviewed. This work is supported by the NASA John Glenn Biomedical Engineering Consortium.

  14. Bone marrow fat.

    Science.gov (United States)

    Hardouin, Pierre; Pansini, Vittorio; Cortet, Bernard

    2014-07-01

    Bone marrow fat (BMF) results from an accumulation of fat cells within the bone marrow. Fat is not a simple filling tissue but is now considered as an actor within bone microenvironment. BMF is not comparable to other fat depots, as in subcutaneous or visceral tissues. Recent studies on bone marrow adipocytes have shown that they do not appear only as storage cells, but also as cells secreting adipokines, like leptin and adiponectin. Moreover bone marrow adipocytes share the same precursor with osteoblasts, the mesenchymal stem cell. It is now well established that high BMF is associated with weak bone mass in osteoporosis, especially during aging and anorexia nervosa. But numerous questions remain discussed: what is the precise phenotype of bone marrow adipocytes? What is the real function of BMF, and how does bone marrow adipocyte act on its environment? Is the increase of BMF during osteoporosis responsible for bone loss? Is BMF involved in other diseases? How to measure BMF in humans? A better understanding of BMF could allow to obtain new diagnostic tools for osteoporosis management, and could open major therapeutic perspectives. PMID:24703396

  15. Dust Reddening in SDSS Quasars

    CERN Document Server

    Hopkins, P F; Hall, P B; Richards, G T; Cooper, A S; Schneider, D P; Vanden Berk, Daniel E; Jester, S; Brinkmann, J; Szokoly, G P; Hopkins, Philip F.; Strauss, Michael A.; Hall, Patrick B.; Richards, Gordon T.; Cooper, Ariana S.; Schneider, Donald P.; Berk, Daniel E. Vanden; Jester, Sebastian; Szokoly, Gyula P.

    2004-01-01

    We explore the form of extragalactic reddening toward quasars using a sample of 9566 quasars with redshifts 0 0.1; less than 1% have E_{B-V} > 0.2, where the extinction is relative to quasars with modal colors. Reddening is uncorrelated with the presence of intervening narrow-line absorption systems, but reddened quasars are much more likely to show narrow absorption at the redshift of the quasar than are unreddened quasars. Thus the reddening towards quasars is dominated by SMC-like dust at the quasar redshift.

  16. Experimental study on mechanical and biomechanical reconstruction of bone defect of long bone near joint%长骨近关节端骨缺损的力学和生物力学结构重建

    Institute of Scientific and Technical Information of China (English)

    胡春明; 张伟; 苏云; 王成学; 徐莘香; 卢宝顺

    2005-01-01

    reconstruction methods.DESIGN: A completely randomized experiment with self-control and mutual control.SETTING: Laboratory for Experimental Animals, First Hospital of Jilin University.MATERIALS: Twelve healthy adult hybrid dogs, 5 males and 7 females weighing 12 to 18 kg, were recruited.METHODS: The bone defects near joints were established in upper femoral condyle in the 12 dogs, which were reconstructed by 3 operation styles: only filling with bone cement, filling with bone cement + autogenous ilium bone graft, and filling with bone cement + autogenous ilium bone graft + fixation with L-trapezoid compression plate. There was one dog in each method. The specimens were harvested at the end of weeks 3, 6, 12and 24, respectively, after operation. One week before specimens were harvested the fluorescent labeling was prepared; we conducted vascular perfusion of disulphine blue before the animals were executed.MAIN OUTCOME MEASURES: A series of examinations were carried out, including X-ray film, biomechanical test, intravascular perfusion and tetracycline fluorescent labeling. The bone healing, blood supply recovery and biomechanics were observed in the three groups.RESULTS: The 12 dogs all entered the result analysis. ① Results of Xray examination: Two cases of fracture occurred in experimental side at 6and 12 weeks in group Ⅰ; one case of fracture occurred in experimental side at 6 weeks in group Ⅱ. No fracture happened in group Ⅲ. ② Bone stiffness assayed with biomechanics: It decreased in experimental side as compared to control side by 67% and 70% in group Ⅰ; 66%, 76% and 46% in group Ⅱ; and 8% in group Ⅲ. ③ Specimen observation after operation: Bone formation, callus, and blood supply recovery were significantly better in group Ⅲ than in groups Ⅰ and Ⅱ at all stages.CONCLUSION: The third operation, filling with bone cement + autogenous ilium bone graft + fixation with L-trapezoid compression plate, is an ideal method of bone reconstruction. It can

  17. Perchlorate in dust fall and indoor dust in Malta: An effect of fireworks.

    Science.gov (United States)

    Vella, Alfred J; Chircop, Cynthia; Micallef, Tamara; Pace, Colette

    2015-07-15

    We report on the presence of perchlorate in the settleable dust of Malta, a small central Mediterranean island. Both dust fall collected directly as it precipitated from atmosphere over a period of one month and deposited indoor dust from domestic residences were studied. Perchlorate was determined by ion chromatography of water extracts of the collected dusts. Dust fall was collected from 43 towns during 2011 to 2013 and indoor dust was sampled from homes in the same localities. Perchlorate was detected in 108 of 153 samples of dust fall (71%) and in 28 of 37 indoor dust samples (76%). Detectable perchlorate in dust fall ranged from 0.52μgg(-1) to 561μgg(-1) with a median value of 6.2μgg(-1); in indoor dust, levels were from 0.79μgg(-1) to 53μgg(-1) with a median value of 7.8μgg(-1), the highest recorded anywhere to date. Statistical analysis suggested that there was no significant difference in perchlorate content of indoor dust and dust fall. Perchlorate levels in dust fall escalate during the summer in response to numerous religious feasts celebrated with fireworks and perchlorate persists at low μgg(-1) concentrations for several months beyond the summer festive period. In Malta, perchlorate derives exclusively from KClO4, imported for fireworks manufacture. Its residue in dust presents an exposure risk to the population, especially via ingestion by hand to mouth transfer. Our results suggest that wherever intensive burning of fireworks takes place, the environmental impact may be much longer lived than realised, mainly due to re-suspension and deposition of contaminated settled dust in the urban environment. PMID:25828411

  18. Interactive Soil Dust Aerosol Model in the GISS GCM. Part 1; Sensitivity of the Soil Dust Cycle to Radiative Properties of Soil Dust Aerosols

    Science.gov (United States)

    Perlwitz, Jan; Tegen, Ina; Miller, Ron L.

    2000-01-01

    The sensitivity of the soil dust aerosol cycle to the radiative forcing by soil dust aerosols is studied. Four experiments with the NASA/GISS atmospheric general circulation model, which includes a soil dust aerosol model, are compared, all using a prescribed climatological sea surface temperature as lower boundary condition. In one experiment, dust is included as dynamic tracer only (without interacting with radiation), whereas dust interacts with radiation in the other simulations. Although the single scattering albedo of dust particles is prescribed to be globally uniform in the experiments with radiatively active dust, a different single scattering albedo is used in those experiments to estimate whether regional variations in dust optical properties, corresponding to variations in mineralogical composition among different source regions, are important for the soil dust cycle and the climate state. On a global scale, the radiative forcing by dust generally causes a reduction in the atmospheric dust load corresponding to a decreased dust source flux. That is, there is a negative feedback in the climate system due to the radiative effect of dust. The dust source flux and its changes were analyzed in more detail for the main dust source regions. This analysis shows that the reduction varies both with the season and with the single scattering albedo of the dust particles. By examining the correlation with the surface wind, it was found that the dust emission from the Saharan/Sahelian source region and from the Arabian peninsula, along with the sensitivity of the emission to the single scattering albedo of dust particles, are related to large scale circulation patterns, in particular to the trade winds during Northern Hemisphere winter and to the Indian monsoon circulation during summer. In the other regions, such relations to the large scale circulation were not found. There, the dependence of dust deflation to radiative forcing by dust particles is probably

  19. Effect of a polynomial arbitrary dust size distribution on dust acoustic solitons

    Energy Technology Data Exchange (ETDEWEB)

    Ishak-Boushaki, M.; Djellout, D.; Annou, R. [Faculty of Physics, USTHB, P.B. 32 El Alia, Bab-ezzouar, Algiers (Algeria)

    2012-07-15

    The investigation of dust-acoustic solitons when dust grains are size-distributed and ions adiabatically heated is conducted. The influence of an arbitrary dust size-distribution described by a polynomial function on the properties of dust acoustic waves is investigated. An energy-like integral equation involving Sagdeev potential is derived. The solitary solutions are shown to undergo a transformation into cnoidal ones under some physical conditions. The dust size-distribution can significantly affect both lower and upper critical Mach numbers for both solitons and cnoidal solutions.

  20. eblur/dust: a modular python approach for dust extinction and scattering

    Science.gov (United States)

    Corrales, Lia

    2016-03-01

    I will present a library of python codes -- github.com/eblur/dust -- which calculate dust scattering and extinction properties from the IR to the X-ray. The modular interface allows for custom defined dust grain size distributions, optical constants, and scattering physics. These codes are currently undergoing a major overhaul to include multiple scattering effects, parallel processing, parameterized grain size distributions beyond power law, and optical constants for different grain compositions. I use eblur/dust primarily to study dust scattering images in the X-ray, but they may be extended to applications at other wavelengths.

  1. Dust polarization and ISM turbulence

    CERN Document Server

    Caldwell, Robert R; Kamionkowski, Marc

    2016-01-01

    Perhaps the most intriguing result of Planck's dust-polarization measurements is the observation that the power in the E-mode polarization is twice that in the B mode, as opposed to pre-Planck expectations of roughly equal dust powers in E and B modes. Here we show how the E- and B-mode powers depend on the detailed properties of the fluctuations in the magnetized interstellar medium. These fluctuations are classified into the slow, fast, and Alfv\\'en magnetohydrodynamic (MHD) waves, which are determined once the ratio of gas to magnetic-field pressures is specified. We also parametrize models in terms of the power amplitudes and power anisotropies for the three types of waves. We find that the observed EE/BB ratio (and its scale invariance) and positive TE correlation cannot be easily explained in terms of favored models for MHD turbulence. The observed power-law index for temperature/polarization fluctuations also disfavors MHD turbulence. We thus speculate that the 0.1--30 pc length scales probed by these ...

  2. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... diagnosis of bone cancer . locate foreign objects in soft tissues around or in bones. top of page How ... Dense bone absorbs much of the radiation while soft tissue, such as muscle, fat and organs, allow more ...

  3. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... is commonly used to diagnose fractured bones or joint dislocation. Bone x-rays are the fastest and ... to view and assess bone fractures, injuries and joint abnormalities. This exam requires little to no special ...

  4. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... of bone cancer . locate foreign objects in soft tissues around or in bones. top of page How ... bone absorbs much of the radiation while soft tissue, such as muscle, fat and organs, allow more ...

  5. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... or in bones. top of page How should I prepare? Most bone x-rays require no special ... to 10 minutes. top of page What will I experience during and after the procedure? A bone ...

  6. Bone marrow (stem cell) donation

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000839.htm Bone marrow (stem cell) donation To use the sharing ... stem cells from a donor's blood. Types of Bone Marrow Donation There are two types of bone ...

  7. Bone Marrow Aspiration and Biopsy

    Science.gov (United States)

    ... Global Sites Search Help? Bone Marrow Aspiration and Biopsy Share this page: Was this page helpful? Also ... Examination Formal name: Bone Marrow Aspiration; Bone Marrow Biopsy Related tests: Complete Blood Count ; WBC Differential ; Reticulocyte ...

  8. Exercise for Your Bone Health

    Science.gov (United States)

    ... supported by your browser. Home Bone Basics Lifestyle Exercise for Your Bone Health Publication available in: PDF ( ... A Complete Osteoporosis Program For Your Information Why Exercise? Like muscle, bone is living tissue that responds ...

  9. Allergens in Paved Road Dust and Airborne Particles

    OpenAIRE

    Miguel, Ann G.; Cass, Glen R.; Glovsky, M. Michael; Weiss, Jay

    1999-01-01

    Paved road dust present on the surface of streets in Southern California consists of a complex mixture of soil dust, deposited motor vehicle exhaust particles, tire dust, brake lining wear dust, plant fragments, and other biological materials. The research presented here shows that allergens from at least 20 different source materials are found in the paved road dust. These include pollens and pollen fragments, animal dander, and molds. When paved road dust is resuspended into the atmosphere ...

  10. Dust Charging in Electronegative SiH4 Plasmas

    Institute of Scientific and Technical Information of China (English)

    DUAN Ping; WANG Zheng-Xiong; LIU Yue; LIU Jin-Yuan; WANG Xiao-Gang

    2005-01-01

    @@ We theoretically investigate the dust charging in electronegative silane (SiH4) plasmas, taking into account the effects of UV photodetachment. It is found that UV photodetachment could significantly lower the dust negative charge and even makes dust grains be positively charged under some special conditions. In addition, the other parameters, involving the negative ion and dust number densities, electron temperature and dust radius, have great effects upon the dust charging.

  11. Giant cell tumor of the patella with a secondary aneurysmal bone cyst: A case report

    Science.gov (United States)

    SONG, MINGZHI; DAI, WEI; SUN, RAN; LIANG, HONGFENG; LIU, BINGWU; WU, YUXUAN; MA, KAI; LU, MING

    2016-01-01

    The substance of the patella is an uncommon location for tumor occurrence and development. The present study reports a case of giant cell tumor (GCT) of the patella, combined with an aneurysmal bone cyst (ABC). To the best of our knowledge, this is the second report of GCT with ABC published in English. GCT is the most common type of benign tumor. Secondary ABC is frequently associated with GCT, but this symbiotic tumor rarely occurs in the patella. A 27-year-old male patient was examined at the outpatient clinic, and clinicopathological characteristics of the tumor were observed. X-ray and computed tomography (CT) scans revealed a lytic lesion located in the center of the right patella. Curettage, followed by autogenic and allograft bone grafting, was performed. Histopathologically, the lesion was diagnosed as a GCT with secondary ABC. No recurrence or metastasis was identified during the 1-year follow-up period. The present study reports a case of GCT with secondary ABC, and discusses the rare location and histopathological type of this tumor, in order to improve diagnosis and treatment of patellar tumors in general. PMID:27313738

  12. Design and Implementation of Space Dust Database

    Institute of Scientific and Technical Information of China (English)

    左维; 李春来; 徐琳; 刘剑; 刘建军

    2004-01-01

    Space debris is very dangerous to the security of on-the-orbit spacecrafts, and it is increasing in number at high speed with the expansion of human space exploration. Space debris has become a serious space pollutant noticed by many astronomers. The increase of space dust sources and the development of research on space dust urgently need space dust data sharing and exchanging. It is necessary for us to establish the Space Dust Database to realize the sharing and canonical management of the data. The Space Dust Database (SDD) management system, based on the 3-layer B/S computer mode, was designed and implemented in this paper. The system's features include significantly improved runtime efficiency, good scalability and maintainability. The Space Dust Database can provide some scientific bases for the study of the chemical constituents, mineral composition, origin and sources of space dust, but also provide excellent data services and decision-making support for the protection of space and model construction of space dust.

  13. The damping of gravitational waves in dust

    CERN Document Server

    Svitek, Otakar

    2008-01-01

    We examine a simple model of interaction of gravitational waves with matter (primarily represented by dust). The aim is to investigate a possible damping effect on the intensity of gravitational wave when passing through media. This might be important for gravitational wave astronomy when the sources are obscured by dust or molecular clouds.

  14. Dust control effectiveness of drywall sanding tools.

    Science.gov (United States)

    Young-Corbett, Deborah E; Nussbaum, Maury A

    2009-07-01

    In this laboratory study, four drywall sanding tools were evaluated in terms of dust generation rates in the respirable and thoracic size classes. In a repeated measures study design, 16 participants performed simulated drywall finishing tasks with each of four tools: (1) ventilated sander, (2) pole sander, (3) block sander, and (4) wet sponge. Dependent variables of interest were thoracic and respirable breathing zone dust concentrations. Analysis by Friedman's Test revealed that the ventilated drywall sanding tool produced significantly less dust, of both size classes, than did the other three tools. The pole and wet sanders produced significantly less dust of both size classes than did the block sander. The block sander, the most commonly used tool in drywall finishing operations, produced significantly more dust of both size classes than did the other three tools. When compared with the block sander, the other tools offer substantial dust reduction. The ventilated tool reduced respirable concentrations by 88% and thoracic concentrations by 85%. The pole sander reduced respirable concentrations by 58% and thoracic by 50%. The wet sander produced reductions of 60% and 47% in the respirable and thoracic classes, respectively. Wet sponge sanders and pole sanders are effective at reducing breathing-zone dust concentrations; however, based on its superior dust control effectiveness, the ventilated sander is the recommended tool for drywall finishing operations. PMID:19367481

  15. 30 CFR 56.9315 - Dust control.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Dust control. 56.9315 Section 56.9315 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND... control. Dust shall be controlled at muck piles, material transfer points, crushers, and on haulage...

  16. Wind modeling of Chihuahuan Desert dust outbreaks

    Science.gov (United States)

    Rivera Rivera, Nancy I.; Gill, Thomas E.; Gebhart, Kristi A.; Hand, Jennifer L.; Bleiweiss, Max P.; Fitzgerald, Rosa M.

    The Chihuahuan Desert region of North America is a significant source of mineral aerosols in the Western Hemisphere, and Chihuahuan Desert dust storms frequently impact the Paso del Norte (El Paso, USA/Ciudad Juarez, Mexico) metropolitan area. A statistical analysis of HYSPLIT back trajectory residence times evaluated airflow into El Paso on all days and on days with synoptic (non-convective) dust events in 2001-2005. The incremental probability—a measure of the areas most likely to have been traversed by air masses arriving at El Paso during dusty days—was only strongly positively associated with the region west-southwest of the city, a zone of known dust source areas. Focused case studies were made of major dust events on 15 April and 15 December 2003. Trajectories approached the surface and MM5 (NCAR/Penn State Mesoscale Model) wind speeds increased at locations consistent with dust sources observed in satellite imagery on those dates. Back trajectory and model analyses suggested that surface cyclones adjacent to the Chihuahuan Desert were associated with the extreme dust events, consistent with previous studies of dust storms in the Southern High Plains to the northeast. The recognition of these meteorological patterns serves as a forecast aid for prediction of dust events likely to impact the Paso del Norte.

  17. Diffuse Galactic Emission from Spinning Dust Grains

    OpenAIRE

    Draine, B. T.; Lazarian, A.

    1997-01-01

    Spinning interstellar dust grains produce detectable rotational emission in the 10-100 GHz frequency range. We calculate the emission spectrum, and show that this emission can account for the ``anomalous'' Galactic background component which correlates with 100um thermal emission from dust. Implications for cosmic background studies are discussed.

  18. Measurement of nicotine in household dust

    International Nuclear Information System (INIS)

    An analytical method of measuring nicotine in house dust was optimized and associations among three secondhand smoking exposure markers were evaluated, i.e., nicotine concentrations of both house dust and indoor air, and the self-reported number of cigarettes smoked daily in a household. We obtained seven house dust samples from self-reported nonsmoking homes and 30 samples from smoking homes along with the information on indoor air nicotine concentrations and the number of cigarettes smoked daily from an asthma cohort study conducted by the Johns Hopkins Center for Childhood Asthma in the Urban Environment. House dust nicotine was analyzed by isotope dilution gas chromatography-mass spectrometry (GC/MS). Using our optimized method, the median concentration of nicotine in the dust of self-reported nonsmoking homes was 11.7 ng/mg while that of smoking homes was 43.4 ng/mg. We found a substantially positive association (r=0.67, P<0.0001) between house dust nicotine concentrations and the numbers of cigarettes smoked daily. Optimized analytical methods showed a feasibility to detect nicotine in house dust. Our results indicated that the measurement of nicotine in house dust can be used potentially as a marker of longer term SHS exposure

  19. Mechanisms of mineral dust-induced emphysema

    Energy Technology Data Exchange (ETDEWEB)

    Churg, A.; Zay, K.; Li, K. [University of British Columbia, Vancouver, BC (Canada). Dept. of Pathology

    1997-09-01

    Mineral dust exposure can result in emphysema and chronic airflow obstruction. It is postulated that dust-induced emphysema has a pathogenesis similar to that in cigarette smoke-induced emphysema, namely, excess release of proteolytic enzymes from dust-evoked inflammatory cells, and inactivation of alpha-1-antitrypsin (A1AT) by dust-catalyzed formation of oxidants. To test this theory the authors examined the antiproteolytic activity of A1AT exposed to quartz in vitro and found that it was decreased in a dose-response fashion. Catalase prevented this effect, which suggested that it was mediated by quartz-generated hydrogen peroxide. A variety of dusts could oxidize methionine to methionine sulfoxide in vitro, using either pure amino acid or whole protein. The relative order of activity was coal {gt} quartz {gt} titanium dioxide. Lastly, a new high-performance liquid chromoatgraphy technique was used to demonstrate that quartz, coal, and titanium dioxide produced connective tissue breakdown in rat lungs, as determined by the appearance of desmosine and hydroxyproline in lavage fluid after dust instillation. On a particle-for-particle basis, the order of dust potency was similar to that for methionine oxidation. Connective tissue breakdown was associated with elevations of both polymorphonuclear leukocytes and macrophages in lavage fluid, and it is unclear whether one or both of these types of inflammatory cell mediates this process. These observations support the theory that dust-induced emphysema and smoke-induced emphysema occur through similar mechanisms.

  20. Martian Arctic Dust Devil, Phoenix Sol 104

    Science.gov (United States)

    2008-01-01

    The Surface Stereo Imager on NASA's Phoenix Mars Lander caught this dust devil in action west-southwest of the lander at 11:16 a.m. local Mars time on Sol 104, or the 104th Martian day of the mission, Sept. 9, 2008. Dust devils have not been detected in any Phoenix images from earlier in the mission, but at least six were observed in a dozen images taken on Sol 104. Dust devils are whirlwinds that often occur when the Sun heats the surface of Mars, or some areas on Earth. The warmed surface heats the layer of atmosphere closest to it, and the warm air rises in a whirling motion, stirring dust up from the surface like a miniature tornado. The dust devil visible in the center of this image just below the horizon is estimated to be about 400 meters (about 1,300 feet) from Phoenix, and 4 meters (13 feet) in diameter. It is much smaller than dust devils that have been observed by NASA's Mars Exploration Rover Spirit much closer to the equator. It is closer in size to dust devils seen from orbit in the Phoenix landing region, though still smaller than those. The image has been enhanced to make the dust devil easier to see. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  1. The Fate of Saharan Dust Across the Atlantic and Implications for a Central American Dust Barrier

    Science.gov (United States)

    Nowottnick, E.; Colarco, P.; da Silva, A.; Hlavka, D.; McGill, M.

    2011-01-01

    Saharan dust was observed over the Caribbean basin during the summer 2007 NASA Tropical Composition, Cloud, and Climate Coupling (TC4) field experiment. Airborne Cloud Physics Lidar (CPL) and satellite observations from MODIS suggest a barrier to dust transport across Central America into the eastern Pacific. We use the NASA GEOS-5 atmospheric transport model with online aerosol tracers to perform simulations of the TC4 time period in order to understand the nature of this barrier. Our simulations are driven by the Modem Era Retrospective-Analysis for Research and Applications (MERRA) meteorological analyses. We evaluate our baseline simulated dust distributions using MODIS and CALIOP satellite and ground-based AERONET sun photometer observations. GEOS-5 reproduces the observed location, magnitude, and timing of major dust events, but our baseline simulation does not develop as strong a barrier to dust transport across Central America as observations suggest. Analysis of the dust transport dynamics and lost processes suggest that while both mechanisms play a role in defining the dust transport barrier, loss processes by wet removal of dust are about twice as important as transport. Sensitivity analyses with our model showed that the dust barrier would not exist without convective scavenging over the Caribbean. The best agreement between our model and the observations was obtained when dust wet removal was parameterized to be more aggressive, treating the dust as we do hydrophilic aerosols.

  2. Dissimilar autogenous full penetration welding of superalloy K418 and 42CrMo steel by a high power CW Nd:YAG laser

    International Nuclear Information System (INIS)

    Experiments of autogenous laser full penetration welding between dissimilar cast Ni-based superalloy K418 and alloy steel 42CrMo flat plates with 3.5 mm thickness were conducted using a 3 kW continuous wave (CW) Nd:YAG laser. The influences of laser welding velocity, flow rate of side-blow shielding gas, defocusing distance were investigated. Microstructure of the welded seam was characterized by optical microscopy (OM), scanning electron microscopy (SEM) and X-ray diffraction (XRD) and energy dispersive spectrometer (EDS). Mechanical properties of the welded seam were evaluated by microhardness and tensile strength testing. Results show that high quality full penetration laser-welded joint can be obtained by optimizing the welding velocity, flow rate of shielding gas and defocusing distance. The laser-welded seam have non-equilibrium solidified microstructures consisting of γ-FeCr0.29Ni0.16C0.06 austenite solid solution dendrites as the dominant and very small amount of super-fine dispersed Ni3Al γ' phase and Laves particles as well as MC needle-like carbides distributed in the interdendritic regions. Although the microhardness of the laser-welded seam was lower than that of the base metal, the strength of the joint was equal to that of the base metal and the fracture mechanism showed fine ductility

  3. Nano-metric Dust Particles as a Hardly Detectable Component of the Interplanetary Dust Cloud

    Indian Academy of Sciences (India)

    I. Simonia; Sh. Nabiyev

    2015-09-01

    The present work introduces the hypothesis of existence of a hardly detectable component of the interplanetary dust cloud and demonstrates that such a component is a dust formation consisting of the dust particles of nano-metric dimensions. This work describes the main physical properties of such a kind of nano-dust, and its possible chemical and mineralogical peculiarities proposes new explanations related to reddening of the dynamically cold transneptunian objects on account of scattering their light by nano-dust of the hardly detectable component of the interplanetary dust cloud. We propose the relation for the coefficient of absorption by the nano-dust and provide results of the statistical analysis of the TNO color index–orbital inclinations. We also present a critical assessment of the proposed hypothesis.

  4. Wnt Signaling in Bone

    Science.gov (United States)

    Kubota, Takuo; Michigami, Toshimi; Ozono, Keiichi

    2010-01-01

    Wnt signaling is involved not only in embryonic development but also in maintenance of homeostasis in postnatal tissues. Multiple lines of evidence have increased understanding of the roles of Wnt signaling in bone since mutations in the LRP5 gene were identified in human bone diseases. Canonical Wnt signaling promotes mesenchymal progenitor cells to differentiate into osteoblasts. The canonical Wnt/β-catenin pathway possibly through Lrp6, a co-receptor for Wnts as well as Lrp5, in osteoblasts regulates bone resorption by increasing the OPG/RANKL ratio. However, endogenous inhibitors of Wnt signaling including sclerostin block bone formation. Regulation of sclerostin appears to be one of the mechanisms of PTH anabolic actions on bone. Since sclerostin is almost exclusively expressed in osteocytes, inhibition of sclerostin is the most promising design. Surprisingly, Lrp5 controls bone formation by inhibiting serotonin synthesis in the duodenum, but not by directly promoting bone formation. Pharmacological intervention may be considered in many components of the canonical Wnt signaling pathway, although adverse effects and tumorigenicity to other tissues are important. More studies will be needed to fully understand how the Wnt signaling pathway actually influences bone metabolism and to assure the safety of new interventions. PMID:23926379

  5. Bone marrow transplantation

    International Nuclear Information System (INIS)

    Peculiarities of clinico-hematologic pattern in patients with acute leukosis when ionizing radiation is used as prepration regime for hystocompatible bone marrow transplantation are listed. Chemico-radiopreparation of patients with acute leukosis is described, different techniques of bone marrow transplantation are presented, secondary signs of the disease are shown

  6. Dust Sensitivity of Absorption-Line Indices

    CERN Document Server

    MacArthur, L A

    2004-01-01

    We investigate the effects of dust extinction on integrated absorption-line indices that are widely used to derive constraints on the ages and metallicities of composite stellar systems. Typically, absorption-line studies have been performed on globular clusters or elliptical galaxies, which are mostly dust-free systems. However, many recent studies of integrated stellar populations have focused on spiral galaxies which may contain significant amounts of dust. It is almost universally assumed that the effects of dust extinction on absorption-line measurements are entirely negligible given the narrow baseline of the spectral features, but no rigorous study has yet been performed to verify this conjecture. In this analysis, we explore the sensitivity of the standard set of Lick absorption-line indices, the higher-order Balmer line indices, the 4000 A break, the near-IR calcium triplet indices, and the Rose indices to dust absorption according to population synthesis models that incorporate a multi-component mod...

  7. Ionization and Dust Charging in Protoplanetary Disks

    CERN Document Server

    Ivlev, A V; Caselli, P

    2016-01-01

    Ionization-recombination balance in dense interstellar and circumstellar environments is a key factor for a variety of important physical processes, such as chemical reactions, dust charging and coagulation, coupling of the gas with magnetic field and the development of magnetorotational instability in protoplanetary disks. We present a self-consistent analytical model which allows us to exactly calculate abundances of charged species in dusty gas, in the regime where the dust-phase recombination dominates over the gas-phase recombination. The model is employed to verify applicability of a conventional approximation of low dust charges in protoplanetary disks, and to discuss the implications for the dust coagulation and the development of the "dead zone" in the disk. Furthermore, the importance of mutually consistent models for the ionization and dust evolution is addressed: These processes are coupled via several mechanisms operating in the disk, and therefore their interplay can be crucial for the ultimate ...

  8. Coke dust enhances coke plant wastewater treatment.

    Science.gov (United States)

    Burmistrz, Piotr; Rozwadowski, Andrzej; Burmistrz, Michał; Karcz, Aleksander

    2014-12-01

    Coke plant wastewater contain many toxic pollutants. Despite physico-chemical and biological treatment this specific type of wastewater has a significant impact on environment and human health. This article presents results of research on industrial adsorptive coke plant wastewater treatment. As a sorbent the coke dust, dozen times less expensive than pulverized activated carbon, was used. Treatment was conducted in three scenarios: adsorptive after full treatment with coke dust at 15 g L(-1), biological treatment enhanced with coke dust at 0.3-0.5 g L(-1) and addition of coke dust at 0.3 g L(-1) prior to the biological treatment. The enhanced biological treatment proved the most effective. It allowed additional removal of 147-178 mg COD kg(-1) of coke dust. PMID:25113994

  9. Recycling of steelmaking dusts: The Radust concept

    Directory of Open Access Journals (Sweden)

    Jalkanen H.

    2005-01-01

    Full Text Available Recycling of dusts and other wastes of steelmaking is becoming to a necessity of two reasons: due to high contents of iron oxides dusts are valuable raw material for steelmaking and tightening environmental legislation makes the landfill disposal of wastes more expensive. Fine dust fractions from various stages of steelmaking route contain besides iron and carbon heavy metals especially zinc and lead and heavy hydrocarbons that are acceptable neither for landfill disposal nor for recycling back to processes without any spe4cial treatments. Some theoretical and practical aspects concerning high temperature treatments of steelmaking dusts for removal of hazardous components and production of clean high iron raw material for recycling is discussed in this paper. The Radust technology developed at Koverhar steelwork in Finland for treatment of the most problematic fine fractions of blast furnace and oxygen converter dusts is shortly presented and discussed.

  10. Thermal solidification of stainless steelmaking dust

    Institute of Scientific and Technical Information of China (English)

    TANG Mo-tang; PENG Ji; PENG Bing; YU Di; TANG Chao-bo

    2008-01-01

    Stainless steelmaking dust makes an environmental problem in the disposal or landfills and has been assigned as a hazardous waste by various government regulatory agencies because it leaches heavy metals to the groundwater or rainwater in the concentrations exceeding the environmental guidelines for solid waste disposal. Solidification of the dust is to stabilize the hazardous components into amorphous silica-alumina-based clays. Various mixtures of stainless steelmaking dust and clay were investigated and the softening temperatures of these mixtures were measured. The results indicate that the mixture of stainless steelmaking dust and clay additive with 1-1 ratio has the lowest softening temperature of 1 100 ℃. The clinkers can pass the TCLP leaching test after being thermally treated at the softening temperature for 15 min. A thermal process for the solidification of stainless steelmaking dust with typical clay is developed and the product is desirable for the production of bricks or disposal and landfill.

  11. INTERPRETATION OF (596) SCHEILA'S TRIPLE DUST TAILS

    International Nuclear Information System (INIS)

    Strange-looking dust cloud around asteroid (596) Scheila was discovered on 2010 December 11.44-11.47. Unlike normal cometary tails, it consisted of three tails and faded within two months. We constructed a model to reproduce the morphology of the dust cloud based on the laboratory measurement of high-velocity impacts and the dust dynamics. As a result, we succeeded in reproducing the peculiar dust cloud by an impact-driven ejecta plume consisting of an impact cone and downrange plume. Assuming an impact angle of 45°, our model suggests that a decameter-sized asteroid collided with (596) Scheila from the direction of (αim, δim) = (60°, –40°) in J2000 coordinates on 2010 December 3. The maximum ejection velocity of the dust particles exceeded 100 m s–1. Our results suggest that the surface of (596) Scheila consists of materials with low tensile strength.

  12. Cosmic Dust in the 21st Century

    CERN Document Server

    Greenberg, J M; Shen, Chuanjian

    2000-01-01

    The past century of interstellar dust has brought us from first ignoring it to finding that it plays an important role in the evolution of galaxies. Current observational results in our galaxy provide a complex physical and chemical evolutionary picture of interstellar dust starting with the formation of small refractory particles in stellar atmospheres to their modification in diffuse and molecular clouds and ultimately to their contribution to star forming regions. Observations of the properties of dust in very young galaxies will be an important probe of the rates of star formation in terms of the production and destruction of dust grains. Future observations of dust at high spectral and spatial resolution will provide detailed information on processes in collapsing clouds up to star formation. Space missions to comets in the next century will first study them in situ but ultimately will bring back pristine nucleus material which will contain the end product of the collapsing protosolar molecular cloud at ...

  13. Models of dust around Europa and Ganymede

    CERN Document Server

    Miljkovic, K; Mason, N J; Zarnecki, J C

    2012-01-01

    We use numerical models, supported by our laboratory data, to predict the dust densities of ejecta outflux at any altitude within the Hill spheres of Europa and Ganymede. The ejecta are created by micrometeoroid bombardment and five different dust populations are investigated as sources of dust around the moons. The impacting dust flux (influx) causes the ejection of a certain amount of surface material (outflux). The outflux populates the space around the moons, where a part of the ejecta escapes and the rest falls back to the surface. These models were validated against existing Galileo DDS (Dust Detector System) data collected during Europa and Ganymede flybys. Uncertainties of the input parameters and their effects on the model outcome are also included. The results of this model are important for future missions to Europa and Ganymede, such as JUICE (JUpiter ICy moon Explorer), recently selected as ESA's next large space mission to be launched in 2022.

  14. Microwave Emission from Galactic Dust Grains

    CERN Document Server

    Draine, B T

    1999-01-01

    Observations of the cosmic microwave background have revealed a component of 10-60 GHz emission from the Galaxy which correlates with 100-140um emission from interstellar dust but has an intensity much greater than expected for the low-frequency tail of the "electric dipole vibrational" emission peaking at dust-correlated free-free emission. The anomalous emission could be due in part to magnetic dipole emission from thermal fluctuations of the magnetization within interstellar dust grains, but only if a substantial fraction of the Fe in interstellar dust resides in magnetic materials such as metallic iron or magnetite. The observed anomalous emission is probably due primarily to electric dipole radiation from spinning ultrasmall interstellar dust grains. This rotational emission is expected to be partially polarized. From the standpoint of minimizing confusion with non-CBR foregrounds, 60-120 GHz appears to be the optimal frequency window.

  15. The normal bone scan

    International Nuclear Information System (INIS)

    This paper discusses applications of the bone scan. It is the most frequently performed nuclear medicine investigation, the commonest indication being the detection of occult metastases, for which purpose the entire skeleton should be imaged. For other purposes it is often adequate to examine only part of the skeleton. The amount of isotope taken up at any site depends primarily on the local rate of bone turnover rather than on bone mass. The scintigraphic appearance therefore does not necessarily correlate with the radiographic one; however, as there is a relationship between the rate at which bone is replaced and the quantity of bone which is present at any point, the two appearances are not entirely unrelated. Recognition of abnormality is based on a detailed knowledge of normal scintigraphic appearances

  16. Bone markers and osteoporosis therapy

    Directory of Open Access Journals (Sweden)

    Francisco Bandeira

    2014-07-01

    Full Text Available Several factors are involved in determining bone quality including bone density, bone turnover, the extent of trabecular bone connectivity, cortical porosity and geometry. Metabolically active and in a continuous process of remodeling, approximately 20% of bone tissue is renewed annually. Bone turn over markers (BTM are frequently used in clinical trials and to provide valid information about the effectiveness of osteoporosis treatment, reflecting the state of bone metabolism and its response to treatment, although they are not useful alone to estimate bone loss. In this review the behavior of BTM from different clinical trials or different osteoporotic drugs will be addressed.

  17. Dust storm events over Delhi: verification of dust AOD forecasts with satellite and surface observations

    Science.gov (United States)

    Singh, Aditi; Iyengar, Gopal R.; George, John P.

    2016-05-01

    Thar desert located in northwest part of India is considered as one of the major dust source. Dust storms originate in Thar desert during pre-monsoon season, affects large part of Indo-Gangetic plains. High dust loading causes the deterioration of the ambient air quality and degradation in visibility. Present study focuses on the identification of dust events and verification of the forecast of dust events over Delhi and western part of IG Plains, during the pre-monsoon season of 2015. Three dust events have been identified over Delhi during the study period. For all the selected days, Terra-MODIS AOD at 550 nm are found close to 1.0, while AURA-OMI AI shows high values. Dust AOD forecasts from NCMRWF Unified Model (NCUM) for the three selected dust events are verified against satellite (MODIS) and ground based observations (AERONET). Comparison of observed AODs at 550 nm from MODIS with NCUM predicted AODs reveals that NCUM is able to predict the spatial and temporal distribution of dust AOD, in these cases. Good correlation (~0.67) is obtained between the NCUM predicted dust AODs and location specific observations available from AERONET. Model under-predicted the AODs as compared to the AERONET observations. This may be mainly because the model account for only dust and no anthropogenic activities are considered. The results of the present study emphasize the requirement of more realistic representation of local dust emission in the model both of natural and anthropogenic origin, to improve the forecast of dust from NCUM during the dust events.

  18. High Latitude Dust in the Earth System

    Science.gov (United States)

    Bullard, Joanna E.; Baddock, Matthew; Bradwell, Tom; Crusius, John; Darlington, Eleanor; Gaiero, Diego; Gasso, Santiago; Gisladottir, Gudrun; Hodgkins, Richard; McCulloch, Robert; McKenna-Neuman, Cheryl; Mockford, Tom; Stewart, Helena; Thorsteinsson, Throstur

    2016-01-01

    Natural dust is often associated with hot, subtropical deserts, but significant dust events have been reported from cold, high latitudes. This review synthesizes current understanding of high-latitude (> or = 50degN and > or = 40degS) dust source geography and dynamics and provides a prospectus for future research on the topic. Although the fundamental processes controlling aeolian dust emissions in high latitudes are essentially the same as in temperate regions, there are additional processes specific to or enhanced in cold regions. These include low temperatures, humidity, strong winds, permafrost and niveo-aeolian processes all of which can affect the efficiency of dust emission and distribution of sediments. Dust deposition at high latitudes can provide nutrients to the marine system, specifically by contributing iron to high-nutrient, low-chlorophyll oceans; it also affects ice albedo and melt rates. There have been no attempts to quantify systematically the expanse, characteristics, or dynamics of high-latitude dust sources. To address this, we identify and compare the main sources and drivers of dust emissions in the Northern (Alaska, Canada, Greenland, and Iceland) and Southern (Antarctica, New Zealand, and Patagonia) Hemispheres. The scarcity of year-round observations and limitations of satellite remote sensing data at high latitudes are discussed. It is estimated that under contemporary conditions high-latitude sources cover >500,000 sq km and contribute at least 80-100 Tg/yr1 of dust to the Earth system (approx. 5% of the global dust budget); both are projected to increase under future climate change scenarios.

  19. Ocular toxicity of authentic lunar dust

    Directory of Open Access Journals (Sweden)

    Meyers Valerie E

    2012-07-01

    Full Text Available Abstract Background Dust exposure is a well-known occupational hazard for terrestrial workers and astronauts alike and will continue to be a concern as humankind pursues exploration and habitation of objects beyond Earth. Humankind’s limited exploration experience with the Apollo Program indicates that exposure to dust will be unavoidable. Therefore, NASA must assess potential toxicity and recommend appropriate mitigation measures to ensure that explorers are adequately protected. Visual acuity is critical during exploration activities and operations aboard spacecraft. Therefore, the present research was performed to ascertain the ocular toxicity of authentic lunar dust. Methods Small (mean particle diameter = 2.9 ± 1.0 μm, reactive lunar dust particles were produced by grinding bulk dust under ultrapure nitrogen conditions. Chemical reactivity and cytotoxicity testing were performed using the commercially available EpiOcularTM assay. Subsequent in vivo Draize testing utilized a larger size fraction of unground lunar dust that is more relevant to ocular exposures (particles Results In vitro testing indicated minimal irritancy potential based on the time required to reduce cell viability by 50% (ET50. Follow-up testing using the Draize standard protocol confirmed that the lunar dust was minimally irritating. Minor irritation of the upper eyelids was noted at the 1-hour observation point, but these effects resolved within 24 hours. In addition, no corneal scratching was observed using fluorescein stain. Conclusions Low-titanium mare lunar dust is minimally irritating to the eyes and is considered a nuisance dust for ocular exposure. No special precautions are recommended to protect against ocular exposures, but fully shielded goggles may be used if dust becomes a nuisance.

  20. Dust in the Quasar Wind (Artist Concept)

    Science.gov (United States)

    2007-01-01

    Dusty grains -- including tiny specks of the minerals found in the gemstones peridot, sapphires and rubies -- can be seen blowing in the winds of a quasar, or active black hole, in this artist's concept. The quasar is at the center of a distant galaxy. Astronomers using NASA's Spitzer Space Telescope found evidence that such quasar winds might have forged these dusty particles in the very early universe. The findings are another clue in an ongoing cosmic mystery: where did all the dust in our young universe come from? Dust is crucial for efficient star formation as it allows the giant clouds where stars are born to cool quickly and collapse into new stars. Once a star has formed, dust is also needed to make planets and living creatures. Dust has been seen as far back as when the universe was less than a tenth of its current age, but how did it get there? Most dust in our current epoch forms in the winds of evolved stars that did not exist when the universe was young. Theorists had predicted that winds from quasars growing in the centers of distant galaxies might be a source of this dust. While the environment close to a quasar is too hot for large molecules like dust grains to survive, dust has been found in the cooler, outer regions. Astronomers now have evidence that dust is created in these outer winds. Using Spitzer's infrared spectrograph instrument, scientists found a wealth of dust grains in a quasar called PG2112+059 located at the center of a galaxy 8 billion light-years away. The grains - including corundum (sapphires and rubies); forsterite (peridot); and periclase (naturally occurring in marble) - are not typically found in galaxies without quasars, suggesting they might have been freshly formed in the quasar's winds.