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Sample records for composite graft selection

  1. Results of Infrainguinal Bypass with a Composite Graft Combining Polytetrafluoroethylene and Vein Graft in Absence of Appropriate Saphenous Vein Graft.

    Science.gov (United States)

    Jin, Myung Jae; Park, Ui Jun; Kim, Hyoung Tae; Roh, Young-Nam

    2017-06-01

    Use of a composite graft combining a polytetrafluoroethylene graft with an autogenous vein is an option for limb salvage in the absence of an adequate single segment vein graft. We aimed to investigate the results of infrainguinal bypass with a composite graft. We retrospectively reviewed 11 infrainguinal arterial bypasses on 11 limbs which underwent surgery from March 2012 to November 2016. Critical limb ischemia was common (63.6%) indication of bypass surgery and most (90.9%) of the patients had history of failed previous treatment including endovascular treatment (36.4%) and bypass surgery (72.7%). At the 2 years after graft implantations, primary patency and amputation-free survival of below-knee bypasses using composite graft were 73% and 76%, respectively. Infrainguinal arterial bypasses with composite graft had an acceptable patency. In patients without other alternative conduits for revascularization, bypass with a composite graft can be an option.

  2. Graft selection in anterior cruciate ligament reconstruction.

    Science.gov (United States)

    Miller, Suzanne L; Gladstone, James N

    2002-10-01

    Selecting the appropriate graft for ACL reconstruction depends on numerous factors including surgeon philosophy and experience, tissue availability (affected by anatomical anomalies or prior injury or surgery), and patient activity level and desires. Although the patella tendon autograft has the widest experience in the literature, and is probably the most commonly used graft source, this must be tempered with the higher reported incidences of potential morbidity and pitfalls associated with its use. The hamstring tendons are gaining increasing popularity, mostly due to reduced harvest morbidity and improved soft tissue fixation techniques, and many recent studies in the literature report equal results to BTB ACL reconstruction with respect to functional outcome and patient satisfaction. On the other hand, many of these studies report higher degrees of instrument (KT-100) tested laxity for hamstring reconstruction, and some have reported lower returns to preinjury levels of activity. One question that remains to be addressed is how closely objectively measured laxity tests correlate with subjectively assessed outcomes and ability to return to high levels of competitive sports. Allograft use, which decreased in popularity during the 1990s, appears to be undergoing a resurgence, with better sterilization processes and new graft sources (tibialis tendons), leading to increased availability and improved fixation techniques. The benefits of decreased surgical morbidity and easier rehabilitation must be weighed against the potential for greater failure of biologic incorporation, infection, and possibly slower return to activities. In our practice, for high-demand individuals (those playing cutting, pivoting, or jumping sports and skiing) BTB tends to be the graft of choice. For lower demand or older individuals, hamstring reconstructions will be performed. Allograft tissue will be used in older individuals (generally over 45 years old), those with signs of arthritis (and

  3. Grafting compatibility between selected rootstocks and Tanzanian ...

    African Journals Online (AJOL)

    The grafted seedlings with graft union tied using grafting clips were healed in a dark chamber for three days and then in a transparent chamber for three days. The average temperature and relative humidity in both chambers were maintained at 21-30°C and 85-95 %, respectively. The grafted seedlings were hardened for ...

  4. Vancomycin graft composite for infected bone defects

    International Nuclear Information System (INIS)

    Winkler, H.; Janata, O.; Georgopoulos, A.

    1999-01-01

    Reconstructive surgery under septic conditions represents a major challenge in orthopaedics. Local application of antibiotics can provide high drug levels at the site of infection without systemic effects. However, removal of non-resorbable implants and filling of defects usually requires additional operative procedures. An ideal antibiotic carrier should provide for : 1) Effective bactericidal activity, especially against staphylococci including MRSA; 2) High and long lasting levels at the site of infection without local or systemic toxicity; 3) Repair of defects without a second stage procedure. Allogeneic cancellous bone is proven to be effective in restoration of bone stock. Vancomycin is effective against all gram-positive populations and the agent of choice for infections with MRSA. The aim of our study is to investigate the efficacy of a combination of both components in bone infection. Cancellous bone of human origin was processed during several steps and incubated in 10% vancomycin solution. The antimicrobial activity of the vancomycin graft composite (VGC) was evaluated using an agar diffusion bioassay against staphylococcus aureus and high performance liquid chromatography (HPLC). The testing period was up to 9 weeks. Elution of vancomycin from the graft was evaluated in 2.5% human albumin solution, which was exchanged every 24 hours. Concentration of vancomycin in allograft-bone was between 6.653[tg/g and 23.194gg/g with an average of 15.250 [tg/g, which is equivalent to 10.000 times the minimum inhibitory concentration (MIC) for s. aureus. The initial activity decreased to approx. 50% during the first week and approx. 30% at the end of the 9th week. The lowest values measured exceeded the MIC by 2000 times. Concentration in surrounding fluid decreased from 24.395,80 to 18,43pg/ml after 11 complete exchanges. Human cancellous bone, processed in an adequate way, offers capability to store high quantities of vancomycin. Vancomycin graft composites are

  5. The effect of carbon dioxide therapy on composite graft survival

    OpenAIRE

    Durães, Eliana Ferreira Ribeiro; Durães, Leonardo de Castro; Carneiro, Fabiana Pirani; Lino Júnior, Ruy de Souza; Sousa, João Batista de

    2013-01-01

    PURPOSE: To investigate the effect of carboxytherapy in auricular composite grafts in rabbits. METHODS: An experimental study was conducted using 20 rabbits randomly assigned to a treatment group of carboxytherapy or a control group of saline solution. In each ear, a circular graft with 1.5 cm or 2 cm of diameter was amputated and reattached. Animals underwent carbon dioxide or saline injection four times during the experiment. We analyzed clinical evolution of the animals, grafts survival, h...

  6. The effect of carbon dioxide therapy on composite graft survival.

    Science.gov (United States)

    Durães, Eliana Ferreira Ribeiro; Durães, Leonardo de Castro; Carneiro, Fabiana Pirani; Lino, Ruy de Souza; Sousa, João Batista de

    2013-08-01

    To investigate the effect of carboxytherapy in auricular composite grafts in rabbits. An experimental study was conducted using 20 rabbits randomly assigned to a treatment group of carboxytherapy or a control group of saline solution. In each ear, a circular graft with 1.5 cm or 2 cm of diameter was amputated and reattached. Animals underwent carbon dioxide or saline injection four times during the experiment. We analyzed clinical evolution of the animals, grafts survival, histopathology features and histomorphometry of collagen. The treated group had a significantly lower weight gain (p=0.038). Histopathology was not significantly different between groups. There was an increase in amount of collagen in 2 cm grafts submitted to carbon dioxide therapy (p=0.003). Carboxytherapy didn't influence graft survival rate for 1.5 cm grafts or 2 cm grafts (p=0.567 and p=0.777, respectively). Carbon dioxide therapy increased the amount of collagen in 2 cm grafts. CO2 was not significantly different from saline infusion on composite grafts survival, but this study suggests that there is a mechanical effect caused by distension which favored graft survival.

  7. Analysis of Cartilage-Polydioxanone Foil Composite Grafts

    Science.gov (United States)

    Kim, James H.; Wong, Brian

    2014-01-01

    This study presents an analytical investigation into the mechanical behavior of a cartilage-polydioxanone (PDS) plate composite grafts. Numerical methods are used to provide a first-order, numerical model of the flexural stiffness of a cartilage-PDS graft. Flexural stiffness is a measure of resistance to bending and is inversely related to the amount of deformation a structure may experience when subjected to bending forces. The cartilage-PDS graft was modeled as a single composite beam. Using Bernoulli-Euler beam theory, a closed form equation for the theoretical flexural stiffness of the composite graft was developed. A parametric analysis was performed to see how the flexural properties of the composite model changed with varying thicknesses of PDS foil. The stiffness of the cartilage-PDS composite using 0.15-mm-thick PDS was four times higher than cartilage alone. The composite with a 0.5-mm-thick PDS graft was only 1.7 times stiffer than the composite with the 0.15-mm-thick PDS graft. Although a thicker graft material will yield higher flexural stiffness for the composite, the relationship between composite stiffness and PDS thickness is nonlinear. After a critical point, increments in graft thickness produce gradually smaller improvements in flexural stiffness. The small increase in stiffness when using the thicker PDS foils versus the 0.15 mm PDS foil may not be worth the potential complications (prolonged foreign body reaction, reduction in nutrient diffusion to cartilage) of using thicker artificial grafts. PMID:24327249

  8. Composite vascular repair grafts via micro-imprinting and electrospinning

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yuanyuan, E-mail: yuanyuan-liu@shu.edu.cn; Hu, Qingxi, E-mail: huqingxi@shu.edu.cn [Rapid Manufacturing Engineering Center, Shanghai University, Shanghai 200444 (China); Shanghai Key Laboratory of Intelligent Manufacturing and Robotics, Shanghai 200072 (China); Xiang, Ke, E-mail: xiangke@shu.edu.cn; Chen, Haiping, E-mail: 519673062@qq.com; Li, Yu, E-mail: liyu@hpu.edu.cn [Rapid Manufacturing Engineering Center, Shanghai University, Shanghai 200444 (China)

    2015-04-15

    Composite vascular grafts formed by micro-imprinting and electrospinning exhibited improved mechanical properties relative to those formed by electrospinning alone. The three-layered composite grafts mimic the three-layered structure of natural blood vessels. The middle layer is made by micro-imprinting poly-p-dioxanone (PPDO), while the inner and outer layers are electrospun mixtures of chitosan and polyvinyl alcohol. The graft morphology is characterized with scanning electron microscopy. For constant graft thicknesses, the PPDO increases the mechanical strength. Cells cultivated on the vascular grafts adhere and proliferate better because of the natural, biological chitosan in the inner and outer layers. Overall, the composite scaffolds could be good candidates for blood vessel repair.

  9. The Correction of a Secondary Bilateral Cleft Lip Nasal Deformity Using Refined Open Rhinoplasty with Reverse-U Incision, V-Y Plasty, and Selective Combination with Composite Grafting: Long-term Results

    Directory of Open Access Journals (Sweden)

    Byung Chae Cho

    2012-05-01

    Full Text Available BackgroundThis article presents long-term outcomes after correcting secondary bilateral cleft lip nasal deformities using a refined reverse-U incision and V-Y plasty or in combination with a composite graft in order to elongate the short columella.MethodsA total of forty-six patients underwent surgery between September 1996 and December 2008. The age of the patients ranged from 3 to 19 years of age. A bilateral reverse-U incision and V-Y plasty were used in 24 patients. A composite graft from the helical root was combined with a bilateral reverse-U incision in the 22 patients who possessed a severely shortened columella. The follow-up period ranged between 2 and 10 years.ResultsA total of 32 patients out of 46 were evaluated postoperatively. The average columella length was significantly improved from an average of 3.7 mm preoperatively to 8.5 mm postoperatively. The average ratio of the columella height to the alar base width was 0.18 preoperatively and 0.29 postoperatively. The postoperative basal and lateral views revealed a better shape of the nostrils and columella. The elongated columella, combined with a composite graft, presented good maintenance of the corrected position with no growth disturbance. A composite graft showed color mismatching in several patients. Twenty-six patients demonstrated no alar-columella web deformity and satisfactory symmetry of the nostrils. Four patients experienced a drooping and overhanging of the corrected alar-columella web.ConclusionsA bilateral reverse-U incision with V-Y plasty or in combination with a composite graft was effective in correcting secondary bilateral cleft lip nasal deformity.

  10. Paediatric fingertip composite grafts: Do they all go black?

    Science.gov (United States)

    Murphy, Adrian D; Keating, Cameron P; Penington, Anthony; McCombe, David; Coombs, Chris J

    2017-02-01

    Fingertip injuries are amongst the most frequently seen hand injuries in the paediatric population. The present study evaluated the composite graft survival rate in distal digital amputations with respect to injury type, amputation level and time to surgery. We performed a retrospective review of patients who underwent composite grafting of fingertip injuries over an 11-year period at a paediatric hospital. All children who underwent non-vascularized replantation of amputated fingertips were included. Patients were excluded if they failed to attend at least one follow-up appointment. Demographic information was recorded. The nature and level of injury and time to surgery was also recorded. Graft viability was characterized as no take, partial take, or complete take. The number of secondary procedures and number and duration of follow-up appointments were recorded. A total of 105 patients underwent fingertip composite grafting, of whom 96 were suitable for inclusion in this study. The median age was 2.4 years (0-16 years); there were 48 boys (46%) and 57 girls (54%). Thirty-one patients had no graft take (32%), 50 patients had partial take (52%) and 15 patients had complete take (16%). Only two patients underwent secondary revision (2%). The median number of follow-up appointments was 4, and the mean follow-up time was 68 days. Time to surgery or level of amputation did not have a statistically significant influence on outcome. Over two-thirds of composite grafts in children showed some degree of take, albeit partially in the majority. Morbidity was low, and most children did not require further surgery. Copyright © 2016 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  11. [Repair of fingertip amputations using composite grafts: nine clinical cases].

    Science.gov (United States)

    Al Saflan, A; May, P; Revol, M; Servant, J-M

    2010-08-01

    Even if a digital replantation is not possible, we present a series of nine cases of fingertip amputations treated with clinical efficacy by using a composite graft from the amputated finger part. All of our eight patients (four children and four adults) were traumatically amputated. The level of amputation passed by the bunch of P3 and carried partially or completely the ungula. The reposition was always performed under local anaesthesia. Our evaluation related on the survival of the composite grafts, the functional and the aesthetic result. The composite grafts were revascularised in eight amputations out of nine, with a satisfactory remote result on the function as well as aesthetic level. After a short recall of the alternative surgical methods of the treatment of the fingertip amputations, we will insist on the simplicity and the reliability of the repositioning of a composite graft, recommended for us from the start and depending on the traumatic level. In the event of a failure, surgeons still have the possibility of realising the other alternative surgical methods. 2009. Published by Elsevier SAS.

  12. Assessment of Competence in EVAR Stent Graft Sizing and Selection

    DEFF Research Database (Denmark)

    Strøm, M; Lönn, L.; Bech, B.

    2017-01-01

    Objectives and background: The aims of this study were to develop a test of competence in endovascular aortic repair (EVAR) stent graft sizing and selection; to examine the test for evidence of validity; and to explore the experience required for the task. Methods: The test was developed based...... on a literature review resulting in 22 anatomical assessment points and a graft selection. Validity evidence was explored in an international cross sectional study. Twenty-two consultants with varying levels of experience in the field (novices, intermediates, and experts) were presented with computed tomography...... angiography of the aortic vessels from three patients. Test scores were based on summed z-scores using the anatomical measurements and graft choices of the experts as a reference. A proficiency score was established using the contrasting groups standard setting method. Results: The assessment was shown...

  13. The Correction of a Secondary Bilateral Cleft Lip Nasal Deformity Using Refined Open Rhinoplasty with Reverse-U Incision, V-Y Plasty, and Selective Combination with Composite Grafting: Long-term Results

    Directory of Open Access Journals (Sweden)

    Byung Chae Cho

    2012-05-01

    Full Text Available Background This article presents long-term outcomes after correcting secondary bilateralcleft lip nasal deformities using a refined reverse-U incision and V-Y plasty or in combinationwith a composite graft in order to elongate the short columella.Methods A total of forty-six patients underwent surgery between September 1996 andDecember 2008. The age of the patients ranged from 3 to 19 years of age. A bilateral reverse-Uincision and V-Y plasty were used in 24 patients. A composite graft from the helical rootwas combined with a bilateral reverse-U incision in the 22 patients who possessed a severelyshortened columella. The follow-up period ranged between 2 and 10 years.Results A total of 32 patients out of 46 were evaluated postoperatively. The average columellalength was significantly improved from an average of 3.7 mm preoperatively to 8.5 mmpostoperatively. The average ratio of the columella height to the alar base width was 0.18preoperatively and 0.29 postoperatively. The postoperative basal and lateral views revealed abetter shape of the nostrils and columella. The elongated columella, combined with a compositegraft, presented good maintenance of the corrected position with no growth disturbance. Acomposite graft showed color mismatching in several patients. Twenty-six patients demonstratedno alar-columella web deformity and satisfactory symmetry of the nostrils. Four patientsexperienced a drooping and overhanging of the corrected alar-columella web.Conclusions A bilateral reverse-U incision with V-Y plasty or in combination with acomposite graft was effective in correcting secondary bilateral cleft lip nasal deformity.

  14. The Effect of Platelet-Rich Plasma on Survival of the Composite Graft and the Proper Time of Injection in a Rabbit Ear Composite Graft Model

    Directory of Open Access Journals (Sweden)

    Hyun Nam Choi

    2014-11-01

    Full Text Available BackgroundAdministration of growth factors has been associated with increased viability of composite grafts greater than 1-cm in diameter. Platelet-rich plasma (PRP contains many of the growth factors studied. In this study, we evaluate the effect of PRP injection on composite graft viability and the proper time for injection.MethodsA total of 24 New Zealand White rabbits were divided into four groups. Autologous PRP was injected into the recipient sites three days before grafting in group 1, on the day of grafting in group 2, and three days after grafting in group 3. Group 4 served as control without PRP administration. Auricular composite grafts of 3-cm diameter were harvested and grafted back into place after being rotated 180 degrees. Median graft viability and microvessel density were evaluated at day 21 of graft via macroscopic photographs and immunofluorescent staining, respectively.ResultsThe median graft survival rate was 97.8% in group 1, 69.2% in group 2, 55.7% in group 3, and 40.8% in the control group. The median vessel counts were 34 (per ×200 HPF in group 1, 24.5 in group 2, 19.5 in group 3, and 10.5 in the control group.ConclusionsThis study demonstrates that PRP administration is associated with increased composite graft viability. All experimental groups showed a significantly higher survival rate and microvessel density, compared with the control group. Pre-administration of PRP was followed by the highest graft survival rate and revascularization. PRP treatments are minimally invasive, fast, easily applicable, and inexpensive, and offer a potential clinical pathway to larger composite grafts.

  15. Fascia compared to one-piece composite cartilage-perichondrium grafting for tympanoplasty.

    Science.gov (United States)

    Lyons, Sarah A; Su, Tanly; Vissers, Linda E T; Peters, Jeroen P M; Smit, Adriana L; Grolman, Wilko

    2016-07-01

    To evaluate the effectiveness of type 1 tympanoplasty with one-piece composite cartilage-perichondrium (CCP) grafts compared to temporalis fascia (TF) grafts for tympanic membrane (TM) closure and hearing improvement in adult patients with a subtotal TM perforation and chronic otitis media (COM). PubMed, Embase, Cochrane Library. A systematic search was conducted. Relevance and validity of selected articles were assessed. Studies that scored moderate or high on relevance were included, and relevant data for both outcomes were extracted. For the outcome of TM closure, absolute risk differences (RD), relative risks, and number needed to treat with their respective 95% confidence intervals were calculated when possible. We retrieved 3,783 unique studies. Ten studies satisfied the eligibility criteria. Four studies of moderate validity showed RD ranging from 0.08 to 0.13 in favor of the CCP graft compared to the TF graft for TM closure 1 year or more postoperatively, but this was not statistically significant. Five studies of moderate to high validity showed no clinically relevant difference in hearing improvement between both intervention groups at a minimum follow-up of 3 months. The relative air-bone gap closure ranged from 5.7 to 11.5 dB in the TF group and from 8.9 to 12.7 dB in the CCP group. There is no evidence of superiority of one-piece CCP grafting over TF grafting in type 1 tympanoplasty regarding complete closure of a subtotal perforated TM 1 year or more postoperatively or hearing improvement at a minimum of 3 months follow-up. Laryngoscope, 126:1662-1670, 2016. © 2015 The American Laryngological, Rhinological and Otological Society, Inc.

  16. Bone scintigraphy in evaluating the viability of composite bone grafts revascularized by microvascular anastomoses, conventional autogenous bone grafts, and free non-revascularized periosteal grafts

    International Nuclear Information System (INIS)

    Berggren, A.; Weiland, A.J.; Ostrup, L.T.

    1982-01-01

    Researchers studied the value of bone scintigraphy in the assessment of anastomotic patency and bone-cell viability in free bone grafts revascularized by microvascular anastomoses in twenty-seven dogs. The dogs were divided into three different groups, and scintigraphy was carried out using technetium-labeled methylene diphosphonate in composite bone grafts revascularized by microvascular anastomoses, conventional autogenous bone grafts, and periosteal grafts placed in different recipient beds. The viability of the grafts were evaluated by histological examination and fluorescence microscopy after triple labeling with oxytetracycline on the first postoperative day, alizarin complexone on the fourth postoperative day, and DCAF on the eleventh postoperative day. A positive scintiscan within the first week following surgery indicated patent microvascular anastomoses, and histological study and fluorescence microscopy confirmed that bone throughout the graft was viable. A positive scintiscan one week after surgery or later does not necessarily indicate microvascular patency or bone-cell survival, because new bone formed by creeping substitution on the surface of a dead bone graft can result in this finding

  17. Selective Adsorption of Pb(II) from Aqueous Solution by Triethylenetetramine-Grafted Polyacrylamide/Vermiculite.

    Science.gov (United States)

    Gu, Shiqing; Wang, Lan; Mao, Xinyou; Yang, Liping; Wang, Chuanyi

    2018-03-28

    Amine groups play significant roles in polymeric composites for heavy metals removal. However, generating a composite with a large number of functional and stable amine groups based on clay is still a challenge. In this work, a new amine-functionalized adsorbent based on acid-activated vermiculite (a-Verm) was prepared by organic modification of silane coupling agent as bridge, followed by in situ polymerization of acrylamide (AM) and further grafting of triethylene tetramine (TETA). The obtained polymeric composite g-PAM/OVerm was characterized by scanning electron microscope (SEM), energy dispersive spectrometer (EDS), Fourier transform infrared (FTIR), thermal analysis (TG/DTG), X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET) analyses, confirming that amine groups were successfully grafted onto the surface of Verm. The efficacy g-PAM/OVerm for removing Pb(II) was tested. The adsorption equilibrium data on g-PAM/OVerm was in good accordance with the Langmuir adsorption isotherms, and the adsorption maximal value of Pb(II) was 219.4 mg·g -1 . The adsorption kinetic data fit the pseudo-second-order kinetic model well. Additionally, g-PAM/OVerm has better selectivity for Pb(II) ion in comparison with Zn(II), Cd(II) and Cu(II) ions. The present work shows that g-PAM/OVerm holds great potential for removing Pb(II) from wastewater, and provides a new and efficient method for the removal of heavy metal ions from industrial wastewater.

  18. Securing aesthetic outcomes for composite grafts to alar margin and columellar defects: A long term experience

    Directory of Open Access Journals (Sweden)

    Rajeev B Ahuja

    2014-01-01

    Full Text Available Introduction: Composite grafts for nasal reconstruction have been around for over a century but the opinion on its virtues and failings keeps vacillating with a huge difference on the safe size of the graft for transfer. Alar margin and columellar defects are more distinct than dorsal nasal defects in greater difficulty in ensuring a good aesthetic outcome. We report our series of 19 consecutive patients in whom a composite graft was used to reconstruct a defect of alar margin (8 patients, alar base (7 patients or columella (4 patients. Patients and Methods: Patient ages ranged from 3-35 years with 5 males and 14 females. The grafts to alar margin and base ranged 0.6-1 cm in width, while grafts to columella were 0.7-1.2 cm. The maximum dimension of the graft in this series was 0.9 mm x 10 mm. Composite grafts were sculpted to be two layered (skin + cartilage, three layered wedges (skin + cartilage + skin or their combination (two layered in a portion and three layered in another portion. All grafts were cooled in postoperative period for three days by applying an indigenous ice pack of surgical glove. The follow up ranged from 3-9 months with an average of 4.5 months. Results: All of our 19 composite grafts survived completely but they all shrank by a small percentage of their bulk. Eleven patients rated the outcome between 90-95% improvement. We noticed that composite grafts tended to show varied pigmentation in our patients, akin to split skin grafts. Conclusion: In our opinion, most critical to graft survival is its size and the ratio of the marginal raw area to the graft bulk. We recommend that graft width should not exceed 1 cm to ensure complete survival even though larger sized grafts have been reported to survive. We recommend cooling of the graft and justify it on the analogy of ′warm ischemia time′ for a replantation, especially in warmer climes like ours in India. We have outlined several considerations in the technique, with an

  19. The effect of platelet-rich plasma on composite graft survival.

    Science.gov (United States)

    Jeon, Yeo Reum; Kang, Eun Hye; Yang, Chae Eun; Yun, In Sik; Lee, Won Jai; Lew, Dae Hyun

    2014-08-01

    Composite grafts are suitable for facial reconstruction because of good color matching, low donor-site morbidity, acceptable texture, and easy surgical techniques. However, their use is limited to small defects and by unpredictable survival rates. As platelet-rich plasma contains large numbers of growth factors and has been widely used for tissue regeneration, this study aimed to investigate platelet-rich plasma as an adjuvant to enhance composite graft survival. Twenty New Zealand White rabbits were used, and chondrocutaneous composite grafts were applied to their ears. The grafts were then returned to their original positions after rotation to block the original circulation from the base of the graft. Each of the individual ears was assigned randomly into one of two groups: experimental (n=20; platelet-rich plasma group) or control (n=20; control group). The surrounding skin of the composite graft was injected with either 1.0 ml of platelet-rich plasma derived from autologous whole blood in the platelet-rich plasma group or normal saline in the control group. Graft survival, cutaneous blood flow, CD31-stained vessels, and vascular endothelial growth factor protein levels were examined. Twelve days after surgery, graft viability in the platelet-rich plasma group was higher than in the control group. Blood perfusion was also higher in the platelet-rich plasma group. Compared with the control group, the number of CD31 blood vessels and vascular endothelial growth factor expression levels were significantly increased in the platelet-rich plasma group. The authors' results suggest that platelet-rich plasma restores the perfusion of composite grafts by enhancing revascularization and may exert therapeutic effects on the survival of composite grafts.

  20. Fascia compared to one-piece composite cartilage-perichondrium grafting for tympanoplasty

    NARCIS (Netherlands)

    Lyons, Sarah A.|info:eu-repo/dai/nl/413920984; Su, Tanly; Vissers, Linda E T|info:eu-repo/dai/nl/413985652; Peters, Jeroen P M|info:eu-repo/dai/nl/413968960; Smit, Adriana L|info:eu-repo/dai/nl/413982084; Grolman, Wilko|info:eu-repo/dai/nl/175476136

    2016-01-01

    OBJECTIVE: To evaluate the effectiveness of type 1 tympanoplasty with one-piece composite cartilage-perichondrium (CCP) grafts compared to temporalis fascia (TF) grafts for tympanic membrane (TM) closure and hearing improvement in adult patients with a subtotal TM perforation and chronic otitis

  1. Potassium diperiodatocuprate-mediated preparation of poly(methyl methacrylate/organo-montmorillonite composites via in situ grafting copolymerization

    Directory of Open Access Journals (Sweden)

    2008-09-01

    Full Text Available In this study, potassium diperiodatocuprate (Cu3+ was selected as an initiator to prepare poly(methyl methacrylate/organo-montmorillonite composites (OMMT-g-PMMA by in situ graft copolymerization. Three synthetic parameters were systematically evaluated as a function of the temperature, the concentration of initiator, pH and the ratio of MMA to OMMT. It was found that Cu3+ was a highly efficient initiator for the preparation of OMMT-g-PMMA i.e., monomer conversion and grafting efficiency were as higher as 95%. The X-ray diffraction measurement showed the intercalation of PMMA chains into OMMT layers on base of an increasing basal spacing after polymerization. FTIR analysis also suggested that the PMMA chains were effectively grafted onto OMMT substrate. The enhanced thermal stabilities of OMMT-g-PMMA composites were confirmed by the thermal gravimetric analysis (TGA. Finally, a single-electron-transfer mechanism was proposed to illustrate the formation of radicals and the preparation process of OMMT-g-PMMA composites. Cu3+ can be used as an effective and practical initiator in preparing the organic/inorganic composite due to its high grafting efficiency and the milder reaction condition.

  2. Composite vascular grafts with high cell infiltration by co-electrospinning

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Zhikai, E-mail: tanzk@hnu.edu.cn; Wang, Hongjie; Gao, Xiangkai; Liu, Tong; Tan, Yongjun

    2016-10-01

    There is an increasing demand for functional small-diameter vascular grafts (diameter < 6 mm) to be used in clinical arterial replacement. An ideal vascular graft should have appropriate biomechanical properties and be biocompatible. Electrospinning has become a popular polymer processing technique for vascular tissue engineering, but the grafts fabricated by electrospinning often have relatively small pores and low porosity, which limit cell infiltration into scaffolds and hinder the regeneration and remodeling of grafts. In the present study, we aimed to develop an efficient method to prepare electrospun composite vascular grafts comprising natural and synthetic materials. We fabricated grafts made of polycaprolactone, gelatin, and polyvinyl alcohol (PVA) by co-electrospinning, and the scaffolds were further functionalized by immobilizing heparin on them. The PVA fibers degraded rapidly in vivo and generated electrospun scaffolds with high porosity, which significantly enhanced cell proliferation and infiltration. The mechanical properties of the grafts are suitable for use in artery replacement. Heparin functionalization of the grafts yielded a good antithrombogenic effect, which was demonstrated in platelet adhesion tests. Moreover, in vitro and in vivo results demonstrated that the heparin release from the grafts enhanced the growth of endothelial cells, which is important for the endothelium of implanted grafts. The results of this study indicate that our method is effective and controllable for the fabrication of vascular grafts that meet the clinical requirements for blood vessel transplantation. - Highlights: • This study indicate an effective method for the fabrication of vascular grafts that meet the clinical requirements. • Co-electrospinning were used to fabricate grafts made of polycaprolactone (PCL), gelatin (GT), and polyvinyl alcohol (PVA). • PVA was used to create large pores within the hybrid scaffolds, thereby enhancing cell infiltration

  3. Composite vascular grafts with high cell infiltration by co-electrospinning

    International Nuclear Information System (INIS)

    Tan, Zhikai; Wang, Hongjie; Gao, Xiangkai; Liu, Tong; Tan, Yongjun

    2016-01-01

    There is an increasing demand for functional small-diameter vascular grafts (diameter < 6 mm) to be used in clinical arterial replacement. An ideal vascular graft should have appropriate biomechanical properties and be biocompatible. Electrospinning has become a popular polymer processing technique for vascular tissue engineering, but the grafts fabricated by electrospinning often have relatively small pores and low porosity, which limit cell infiltration into scaffolds and hinder the regeneration and remodeling of grafts. In the present study, we aimed to develop an efficient method to prepare electrospun composite vascular grafts comprising natural and synthetic materials. We fabricated grafts made of polycaprolactone, gelatin, and polyvinyl alcohol (PVA) by co-electrospinning, and the scaffolds were further functionalized by immobilizing heparin on them. The PVA fibers degraded rapidly in vivo and generated electrospun scaffolds with high porosity, which significantly enhanced cell proliferation and infiltration. The mechanical properties of the grafts are suitable for use in artery replacement. Heparin functionalization of the grafts yielded a good antithrombogenic effect, which was demonstrated in platelet adhesion tests. Moreover, in vitro and in vivo results demonstrated that the heparin release from the grafts enhanced the growth of endothelial cells, which is important for the endothelium of implanted grafts. The results of this study indicate that our method is effective and controllable for the fabrication of vascular grafts that meet the clinical requirements for blood vessel transplantation. - Highlights: • This study indicate an effective method for the fabrication of vascular grafts that meet the clinical requirements. • Co-electrospinning were used to fabricate grafts made of polycaprolactone (PCL), gelatin (GT), and polyvinyl alcohol (PVA). • PVA was used to create large pores within the hybrid scaffolds, thereby enhancing cell infiltration

  4. Preparation and characterization of a novel bone graft composite ...

    Indian Academy of Sciences (India)

    ... shown better mechanical properties. X-ray diffraction (XRD) data indicated the crystallographic nature of BA is akin to hydroxyapatite (HA) and both BA and ESP did not lose their crystalline nature when bone grafts were prepared. This revealed that ESP may be used as a component in bone graft utilizing the solid waste ...

  5. Nipple-areolar complex (nac) composite grafts in the Management ...

    African Journals Online (AJOL)

    composite” graft. This is because the skin of the areola and especially the nipple are usually thicker than the case is in the usual full-thickness skin grafts (FTSG). In traditional breast reductions, the nipple-areolar complex is located to its new position ...

  6. Composite vascular grafts with high cell infiltration by co-electrospinning.

    Science.gov (United States)

    Tan, Zhikai; Wang, Hongjie; Gao, Xiangkai; Liu, Tong; Tan, Yongjun

    2016-10-01

    There is an increasing demand for functional small-diameter vascular grafts (diameterElectrospinning has become a popular polymer processing technique for vascular tissue engineering, but the grafts fabricated by electrospinning often have relatively small pores and low porosity, which limit cell infiltration into scaffolds and hinder the regeneration and remodeling of grafts. In the present study, we aimed to develop an efficient method to prepare electrospun composite vascular grafts comprising natural and synthetic materials. We fabricated grafts made of polycaprolactone, gelatin, and polyvinyl alcohol (PVA) by co-electrospinning, and the scaffolds were further functionalized by immobilizing heparin on them. The PVA fibers degraded rapidly in vivo and generated electrospun scaffolds with high porosity, which significantly enhanced cell proliferation and infiltration. The mechanical properties of the grafts are suitable for use in artery replacement. Heparin functionalization of the grafts yielded a good antithrombogenic effect, which was demonstrated in platelet adhesion tests. Moreover, in vitro and in vivo results demonstrated that the heparin release from the grafts enhanced the growth of endothelial cells, which is important for the endothelium of implanted grafts. The results of this study indicate that our method is effective and controllable for the fabrication of vascular grafts that meet the clinical requirements for blood vessel transplantation. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Plasma-grafting polymerization on carbon fibers and its effect on their composite properties

    Science.gov (United States)

    Zhang, Huanxia; Li, Wei

    2015-11-01

    Interfacial adhesion between matrix and fibers plays a crucial role in controlling the performance of composites. Carbon fibers have the major constraint of chemical interness and hence have limited adhesion with the matrix. Surface treatment of fibers is the best solution to this problem. In this work, carbon fibers were activated by plasma and grafting polymerization. The grafting ratio of polymerization was obtained by acid-base titration. The chemical and physical changes induced by the treatments on carbon fiber surface was examined using contact angle measurements, X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR) technique. The interfacial adhesion of CF/EP (carbon fiber/epoxy) composites were analyzed by a single fiber composite (SFC) for filament fragmentation test. Experimental results show that the grafting rate was not only the function of the plasma-treat time but also the concentration of the grafting polymerization. The oxygen-containing groups (such as Csbnd O, Cdbnd O, and Osbnd Cdbnd O) and the interfacial shear strength (IFSS) of the plasma-grafting carbon fiber increased more significantly than the carbon fiber without plasma treatment grafted with MAH. This demonstrates that the surfaces of the carbon fiber samples are more active, hydrophilic, and rough after plasma-grafting treatments using a DBD operating in ambient argon mixture with oxygen. With DBD (dielectric barrier discharges) operating in ambient argon mixture with oxygen, the more active, hydrophilic, and rough surface was obtained by the plasma-grafting treatments.

  8. Effect of a selective thromboxane synthase inhibitor on arterial graft patency and platelet deposition in dogs

    International Nuclear Information System (INIS)

    McDaniel, M.D.; Huntsman, W.T.; Miett, T.O.; Cronenwett, J.L.

    1987-01-01

    This study examined the effect of selective thromboxane synthase inhibition and nonselective cyclooxygenase inhibition on vascular graft patency and indium 111-labeled platelet deposition in 35 mongrel dogs undergoing carotid artery replacement with 4 mm X 4 cm polytetrafluoroethylene (PTFE) (one side) and Dacron (opposite side) end-to-end grafts. Aspirin-dipyridamole therapy improved one-week graft patency, from 46% in untreated dogs to 93% in treated dogs. Thromboxane synthase inhibition (U-63557A) improved graft patency in these dogs to 81%. Both drug treatments reduced platelet deposition on Dacron and PTFE grafts by 48% to 68% compared with control dogs. Dacron grafts accumulated significantly more platelets than PTFE grafts but had comparable patency rates. Low-dose aspirin therapy had no significant effect on either graft patency or platelet deposition. All treatment groups showed a 60% to 76% reduction in serum thromboxane B2, but only thromboxane synthase inhibitor treatment increased plasma 6-keto-prostaglandin F1 alpha by 100%. Selective thromboxane synthase inhibition improved small-caliber prosthetic graft patency to the same extent as did conventional cyclooxygenase inhibition in this preliminary study

  9. Comprehensive mechanical characterization of PLA fabric combined with PCL to form a composite structure vascular graft.

    Science.gov (United States)

    Li, Chaojing; Wang, Fujun; Douglas, Graeham; Zhang, Ze; Guidoin, Robert; Wang, Lu

    2017-05-01

    Vascular grafts made by tissue engineering processes are prone to buckling and twisting, which can impede blood flow and lead to collapse of the vessel. These vascular conduits may suffer not only from insufficient tensile strength, but also from vulnerabilities related to compression, torsion, and pulsatile pressurization. Aiming to develop a tissue engineering-inspired blood conduit, composite vascular graft (cVG) prototypes were created by combining a flexible polylactic acid (PLA) knitted fabric with a soft polycaprolactone (PCL) matrix. The graft is to be populated in-situ with cellular migration and proliferation into the device. Comprehensive characterizations probed the relationship between structure and mechanical properties of the different cVG prototypes. The composite grafts exhibited major improvements in mechanical characteristics compared to single-material devices, with particular improvement in compression and torsional resistance. A commercial expanded polytetrafluoroethylene (ePTFE) vascular graft was used as a control against the proposed composite vascular grafts. CVG devices showed high tensile strength, high bursting strength, and improved suture retention. Compression, elastic recovery, and compliance were similar to those for the ePTFE graft. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Selective Adsorption of Pb(II from Aqueous Solution by Triethylenetetramine-Grafted Polyacrylamide/Vermiculite

    Directory of Open Access Journals (Sweden)

    Shiqing Gu

    2018-03-01

    Full Text Available Amine groups play significant roles in polymeric composites for heavy metals removal. However, generating a composite with a large number of functional and stable amine groups based on clay is still a challenge. In this work, a new amine-functionalized adsorbent based on acid-activated vermiculite (a-Verm was prepared by organic modification of silane coupling agent as bridge, followed by in situ polymerization of acrylamide (AM and further grafting of triethylene tetramine (TETA. The obtained polymeric composite g-PAM/OVerm was characterized by scanning electron microscope (SEM, energy dispersive spectrometer (EDS, Fourier transform infrared (FTIR, thermal analysis (TG/DTG, X-ray photoelectron spectroscopy (XPS and Brunauer–Emmett–Teller (BET analyses, confirming that amine groups were successfully grafted onto the surface of Verm. The efficacy g-PAM/OVerm for removing Pb(II was tested. The adsorption equilibrium data on g-PAM/OVerm was in good accordance with the Langmuir adsorption isotherms, and the adsorption maximal value of Pb(II was 219.4 mg·g−1. The adsorption kinetic data fit the pseudo-second-order kinetic model well. Additionally, g-PAM/OVerm has better selectivity for Pb(II ion in comparison with Zn(II, Cd(II and Cu(II ions. The present work shows that g-PAM/OVerm holds great potential for removing Pb(II from wastewater, and provides a new and efficient method for the removal of heavy metal ions from industrial wastewater.

  11. The composite aortic wall graft technique: an option for a short coronary artery bypass graft

    Directory of Open Access Journals (Sweden)

    João Bosco de Oliveira

    2009-01-01

    Full Text Available SUMMARY: During coronary artery bypass graft (CABG surgery, the saphenous vein is sutured through its proximal segment to the aorta. Intimal hyperplasia is one of the possible causes of graft occlusion. Notably, blood turbulence can induce wall shear stress that may also play an important role in this process. OBJECTIVE: We propose a new technique for performing proximal anastomosis to avoid CABG failure. METHOD: An 80 kg pig was subjected to open heart surgery. Four stitches were placed in the anterior ascending aorta, which formed a 2 cm by 4 cm patch. This patch was isolated through the application of a tangential clamp that was oriented parallel to the axis of the aorta. After releasing the patch, which was held to the aorta through its cranial end pedicle, the rims were sutured to each other creating a conduit with a length of 4 cm and an internal diameter of 4 mm. The rest of the aortotomy was closed by placing a direct suture between its rims. RESULT: This novel technique created an "in situ" aortic wall graft that was 4 cm long and characterized as being of uniform 4 mm caliber.

  12. Effects of Human Adipose-Derived Stem Cells on the Survival of Rabbit Ear Composite Grafts

    Directory of Open Access Journals (Sweden)

    Chae Min Kim

    2017-09-01

    Full Text Available Background Composite grafts are frequently used for facial reconstruction. However, the unpredictability of the results and difficulties with large defects are disadvantages. Adipose-derived stem cells (ADSCs express several cytokines, and increase the survival of random flaps and fat grafts owing to their angiogenic potential. Methods This study investigated composite graft survival after ADSC injection. Circular chondrocutaneous composite tissues, 2 cm in diameter, from 15 New Zealand white rabbits were used. Thirty ears were randomly divided into 3 groups. In the experimental groups (1 and 2, ADSCs were subcutaneously injected 7 days and immediately before the operation, respectively. Similarly, phosphate-buffered saline was injected in the control group just before surgery in the same manner as in group 2. In all groups, chondrocutaneous composite tissue was elevated, rotated 90 degrees, and repaired in its original position. Skin flow was assessed using laser Doppler 1, 3, 6, 9, and 12 days after surgery. At 1 and 12 days after surgery, the viable area was assessed using digital photography; the rabbits were euthanized, and immunohistochemical staining for CD31 was performed to assess neovascularization. Results The survival of composite grafts increased significantly with the injection of ADSCs (P<0.05. ADSC injection significantly improved neovascularization based on anti-CD31 immunohistochemical analysis and vascular endothelial growth factor expression (P<0.05 in both group 1 and group 2 compared to the control group. No statistically significant differences in graft survival, anti-CD31 neovascularization, or microcirculation were found between groups 1 and 2. Conclusions Treatment with ADSCs improved the composite graft survival, as confirmed by the survival area and histological evaluation. The differences according to the injection timing were not significant.

  13. Aortic root surgery in Marfan syndrome: Comparison of aortic valve-sparing reimplantation versus composite grafting.

    Science.gov (United States)

    Karck, Matthias; Kallenbach, Klaus; Hagl, Christian; Rhein, Christine; Leyh, Rainer; Haverich, Axel

    2004-02-01

    The objective of this study was to compare the results of aortic valve-sparing reimplantation and aortic root replacement with mechanical valve conduits in patients with Marfan syndrome undergoing operation for aortic root aneurysms. Patients and methods Between March 1979 and April 2002, 119 patients with clinical evidence of Marfan syndrome underwent composite graft replacement with mechanical valve conduits (n = 74) or aortic valve-sparing reimplantation according to David (n = 45). The underlying causes were aortic dissection type A (43 patients) and aneurysms (76 patients). Patients undergoing aortic valve reimplantation were younger compared with patients undergoing composite grafting (28 vs 35 years, P =.002) and had longer intraoperative aortic crossclamp times (125 vs 78 minutes, P valve reimplantation (P =.15). Mean follow-up was 30 months for patients undergoing aortic valve reimplantation and 114 months for patients undergoing composite grafting. Freedom from reoperation and death after 5 years postoperatively was 92% and 89% in patients undergoing composite grafting and 84% and 96% in patients undergoing aortic valve reimplantation (P =.31; P =.54), respectively. Thromboembolic complications or late postoperative bleeding occurred in 17 patients undergoing composite grafting, and an early postoperative event occurred in 1 patient undergoing aortic valve reimplantation. The results of aortic valve reimplantation and composite grafting of the aortic valve and ascending aorta with mechanical valve conduits are similar with regard to early and mid-term postoperative mortality and to the incidence of late reoperations in patients with Marfan syndrome. The low risk of thromboembolic or bleeding complications favors aortic valve reimplantation in these patients.

  14. Mixed nano/micro-sized calcium phosphate composite and EDTA root surface etching improve availability of graft material in intrabony defects: an in vivo scanning electron microscopy evaluation.

    Science.gov (United States)

    Gamal, Ahmed Y; Iacono, Vincent J

    2013-12-01

    The use of nanoparticles of graft materials may lead to breakthrough applications for periodontal regeneration. However, due to their small particle size, nanoparticles may be eliminated from periodontal defects by phagocytosis. In an attempt to improve nanoparticle retention in periodontal defects, the present in vivo study uses scanning electron microscopy (SEM) to evaluate the potential of micrograft particles of β-tricalcium phosphate (β-TCP) to enhance the binding and retention of nanoparticles of hydroxyapatite (nHA) on EDTA-treated and non-treated root surfaces in periodontal defects after 14 days of healing. Sixty patients having at least two hopeless periodontally affected teeth designated for extraction were randomly divided into four treatment groups (15 patients per group). Patients in group 1 had selected periodontal intrabony defects grafted with nHA of particle size 10 to 100 nm. Patients in group 2 were treated in a similar manner but had the affected roots etched for 2 minutes with a neutral 24% EDTA gel before grafting of the associated vertical defects with nHA. Patients in group 3 had the selected intrabony defects grafted with a composite graft consisting of equal volumes of nHA and β-TCP (particle size 63 to 150 nm). Patients in group 4 were treated as in group 3 but the affected roots were etched with neutral 24% EDTA as in group 2. For each of the four groups, one tooth was extracted immediately, and the second tooth was extracted after 14 days of healing for SEM evaluation. Fourteen days after surgery, all group 1 samples were devoid of any nanoparticles adherent to the root surfaces. Group 2 showed root surface areas 44.7% covered by a single layer of clot-blended grafted particles 14 days following graft application. After 14 days, group 3 samples appeared to retain fibrin strands devoid of grafted particles. Immediately extracted root samples of group 4 had adherent graft particles that covered a considerable area of the root surfaces

  15. Tensile Properties of Polyimide Composites Incorporating Carbon Nanotubes-Grafted and Polyimide-Coated Carbon Fibers

    Science.gov (United States)

    Naito, Kimiyoshi

    2014-09-01

    The tensile properties and fracture behavior of polyimide composite bundles incorporating carbon nanotubes-grafted (CNT-grafted) and polyimide-coated (PI-coated) high-tensile-strength polyacrylonitrile (PAN)-based (T1000GB), and high-modulus pitch-based (K13D) carbon fibers were investigated. The CNT were grown on the surface of the carbon fibers by chemical vapor deposition. The pyromellitic dianhydride/4,4'-oxydianiline PI nanolayer coating was deposited on the surface of the carbon fiber by high-temperature vapor deposition polymerization. The results clearly demonstrate that CNT grafting and PI coating were effective for improving the Weibull modulus of T1000GB PAN-based and K13D pitch-based carbon fiber bundle composites. In addition, the average tensile strength of the PI-coated T1000GB carbon fiber bundle composites was also higher than that of the as-received carbon fiber bundle composites, while the average tensile strength of the CNT-grafted T1000GB, K13D, and the PI-coated K13D carbon fiber bundle composites was similar to that of the as-received carbon fiber bundle composites.

  16. Doppler echocardiographic criteria in patency assessment of composite grafts from left internal thoracic artery

    Directory of Open Access Journals (Sweden)

    Maria Claudia A. Leitão

    2013-06-01

    Full Text Available OBJECTIVES: The purpose of our study was to establish, with an entirely noninvasive method, transthoracic Doppler echocardiography, criteria for patency of composite left internal thoracic artery grafts when placed on the left anterior descending artery and other branches of the left coronary system. METHODS: The control group comprised 20 patients with single graft and 20 patients with composite graft; all forty having their patency confirmed by coronary angiogram (CA. In this control group, two Doppler echocardiographic variables, diastolic mean velocity-time and integral diastolic peak velocity to systolic peak velocity ratio were recorded. For each variable, established cut-off points were established, using the ROC (Receiver Operator Characteristic curves, to identify criteria which could differentiate the composite grafts. Only patients with composite grafts were included in the 159-patients study group. The criteria established by the cut-off points in the control group were then applied to detect patency using a diastolic fraction of > 0.5 as the gold standard. The sensitivity, specificity, and positive and negative predictive values of these two criteria were determined. RESULTS: In the control group, cut-off points of 0.71 and 0.09m were established for the diastolic peak velocity/systolic peak velocity ratio and for diastolic mean velocity-time integral, respectively. In the study group phase, the sensitivity and negative predictive value of the diastolic peak velocity/systolic peak velocity > 0.71 criterion were 36% and 11%, respectively. Diastolic mean velocity-time integral > 0.09m criterion, were 40% and 10.48%. The specificities and positive predictive values of each criterion were 100%. CONCLUSION: Values reaching the criteria established for each variable indicate high probability of composite graft patency. Lower values have a large proportion of false negatives and are not conclusive as patency criteria.

  17. Comparison of results of graft uptake using tragal cartilage perichondrium composite graft versus temporalis fascia in patients undergoing surgery for chronic otitis media - squamous type.

    Science.gov (United States)

    Khalilullah, S; Shah, Shankar P; Yadav, D; Shrivastav, R P; Bhattarai, H

    2016-08-02

    To assess, analyze and compare the results of graft uptake using Tragal Cartilage-Perichondrium Composite (TCPC) graft with Temporalis Fascia (TF) graft in patients who undergoing surgery for chronic otitis media - squamous type. Patients aged 13 years and above with diagnosis of chronic otitis media - squamous type undergoing modified radical mastoidectomy, either primary or revision surgery with grafting of tympanic membrane (TM) and patients undergoing excision of postero-superior retraction pocket (PSRP) were included in this study. Patients were divided in two groups: Group A-patients undergoing TCPC graft and Group B -patients undergoing TF graft. Graft uptake results were assessed between 8-12 weeks of surgery. In both Groups there were 30 patients each. In Group A successful graft uptake was seen in 27 patients (90 %) and failure of graft uptake was seen in 3 patients(10 %). In Group B successful graft uptake was seen in 28 patients (93.3 %) and failure in 2 patients (6.67 %).Out of the total 60 patients, 11 patients had PSRP. All 6 patients with PSRP in Group A had successful graft uptake and no retraction. Among the 5 patients with PSRP in Group B all patients had sucessful graft uptake, however, in 2 patients retraction of the tympanic membrane was seen similar to the preoperative findings. There was no statistical difference (p = 0.433) between the use of temporalis fascia or tragal cartilage perichondrium in patients undergoing surgery for chronic otitis media - squamous type.

  18. Bifunctional groups grafted polyethersulfone magnetic beads for selective sequestration of plutonium

    International Nuclear Information System (INIS)

    Paul, Sumana; Aggarwal, S.K.; Pandey, A.K.

    2014-01-01

    The present study involves synthesis of polyethersulfone (PES) beads grafted with two different monomers viz. 2-hydroxyethylmethacrylate phosphoric acid ester (HEMP) and 2-acrylamido-2-methyl-1-propane sulphonic acid (AMPS) by photo-induced free radical polymerization method. The selection of bifunctional polymer was based on our previous studies, which indicated its efficacy for selective preconcentration of Pu from 3-4 mol L -1 HNO 3 . The HEMP-co-AMPS grafted PES beads were used for selective extraction of plutonium from dissolver solution

  19. Current trends in selection of conduits for coronary artery bypass grafting.

    Science.gov (United States)

    Carrel, Thierry; Winkler, Bernhard

    2017-10-01

    The procedure of coronary artery bypass grafting continues to be the "gold standard" for patients with multivessel coronary artery disease and left main stenosis due to favourable long-term and consistent outcomes despite the advent of new generations of stents. But the targeted better long-term outcome of surgical revascularization over percutaneous interventions depends on several variables and aspects; one of them is the choice of conduits used to bypass the stenosed arteries. Coronary artery bypass surgery has been studied and debated for decades and the same applies to the selection of grafts. Current data provide significant benefits for patients who receive full arterial revascularization using both internal thoracic arteries and, if applicable, the radial artery. Unfortunately, the use of multiple arterial grafts is still not performed widely despite the evidence of superiority over multiple saphenous vein grafts that are still the most used grafts in cardiovascular procedures. In this review article, we present current trends and evidences for graft selection and give an overview of controversial data regarding the comparison of the radial artery and saphenous vein. Additionally, few words are spelt on alternative conduits.

  20. Use of platelet-rich plasma solution applied with composite chondrocutaneous graft technique: an experimental study in rabbit model.

    Science.gov (United States)

    Sevim, Kamuran Zeynep; Yazar, Memet; Irmak, Fatih; Tekkeşin, Merva Soluk; Yildiz, Kemalettin; Sirvan, Selami Serhat

    2014-07-01

    Composite chondrocutaneous grafts have been used widely for patients with cleft lip nasal deformity, alar defects, and septal perforations; however, the graft viability can be easily compromised. The aim of the present study was to extend the safe length of the composite chondrocutaneous grafts by enhancement of angiogenesis and re-epithelialization through platelet-rich plasma (PRP) and to investigate the changes that occur when PRP is administered to the graft and the recipient site. Composite grafts of critical sizes (1.5, 2.0, and 2.5 cm) were planned on the rabbit ears on 1 side. Group A consisted of grafts pretreated with PRP, group B consisted of recipient beds pretreated with PRP, and group C was the control group in which defects 1.5, 2.0, and 2.5 cm in size were formed on the right ears of the rabbits. On postoperative day 7, matching size chondrocutaneous grafts were adapted to the defect areas without PRP. In all groups, graft viability was evaluated 7 days after graft adaptation in group C and 14 days after PRP administration in groups A and B. Wound healing was scored histopathologically and immunohistologically using hematoxylin and eosin, CD34, and smooth muscle actin staining. The terminal transferase fluorescein-dUTP nick end labeling assay was performed to quantitatively demonstrate the apoptosis ratio among the groups. In groups A, B, and C, the mean graft survival of the 2.0-cm equilateral triangle-shaped composite grafts was 65.43% ± 15.7%, 78.12% ± 12.8%, and 41.31% ± 37.4%, respectively (P = .0364). PRP pretreatment accelerated composite graft survival in the 2.0-cm equilateral triangle grafts by increasing epithelial regeneration and fibrosis, inducing neovascularization, and ameliorating apoptosis rates. Copyright © 2014 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  1. Composite grafting with pulp adipofascial advancement flaps for treating non-replantable fingertip amputations.

    Science.gov (United States)

    Lai, Hsin-Ti; Wu, Sheng-Hua; Lai, Ya-Wei; Hsieh, Tung-Ying; Lee, Su-Shin; David Wang, Hui-Min; Chang, Kao-Ping; Lin, Sin-Daw; Lai, Chung-Sheng; Huang, Shu-Hung

    2016-11-01

    Non-replantable fingertip amputation is still a clinical challenge. We performed modified composite grafting with pulp adipofascial advancement flap for Hirase IIA fingertip amputations. Results from a series of patients are presented and achieved better outcome than traditional composite grafting. From September 2012 to April 2014, fourteen patients with sixteen digits were included in our study. Mean age of patients was 43.9 years (20-71 years). All of our patients underwent this procedure under digital block anesthesia. We performed pulp adipofascial advancement flap for better soft tissue coverage of bone exposure stump first. The amputated parts were defatted, trimming, and reattached as composite graft. Age and gender of patients, injured finger, Hirase classification, mechanism of trauma, overall graft survival area, two-point discrimination (2PD) (mm) at six-month, length of shortening of digit, The average disabilities of the arm, shoulder, and hand (DASH) score and subjective self-evaluation questionnaire at 6 month were recorded. Average graft survival area was 89% (75-100%). Average length of shortening was 2.2 mm (1.8-3.5 mm). 2PD at six-month after surgery was 6.3 mm in average (5-8 mm). Average DASH score at 6 month was 1.45 (0.83-2.5). The self-evaluated aesthetic results showed twelve patients (85.7%) were very satisfied, and no patient was completely unsatisfied. In Hirase zone IIA traumatic fingertip amputation where replantation is difficult, our modified technique of composite grafting with pulp adipofascial advancement flap provided an alternative choice with high successful rate, acceptable functional and aesthetic outcomes. © 2016 Wiley Periodicals, Inc. Microsurgery, 2016. © 2015 Wiley Periodicals, Inc. Microsurgery 36:651-657, 2016. © 2016 Wiley Periodicals, Inc.

  2. Minimizing Superficial Thermal Injury Using Bilateral Cryogen Spray Cooling During Laser Reshaping of Composite Cartilage Grafts

    Science.gov (United States)

    Chang, Cheng-Jen; Cheng, Sally M.H.; Chiu, Lynn L.; Wong, Brian J.F.; Ting, Keen

    2014-01-01

    Composite cartilage grafts were excised from New Zealand rabbit ears. Flat composite grafts (of cartilage and overlying skin graft on both surfaces) were obtained from each ear and cut into a rectangle measuring 50 mm by 25 mm (x by y) with an average thickness of approximately 1.3 mm (z), skin included. Specimens were manually deformed with a jig and maintained in this new position during laser illumination. The composite cartilage grafts were illuminated on the concave surface with an Nd:YAG laser (1,064 nm, 3 mm spot) at 10 W, 20 W, 30 W, 40 W, 50 W. Cryogen spray cooling (CSC) was applied to both exterior (convex) and interior (concave) surfaces of the tissue to reduce thermal injury to the grafts. CSC was delivered: (1) in controlled applications (cryogen released when surface reached 40°C, and (2) receiving only laser at above wattage, no CSC [representing the control group]. The specimens were maintained in a deformation for 15 minutes after illumination and serially examined for 14 days. The control group with no CSC caused injury to all specimens, ranging from minor to full thickness epidermal thermal injury. Although most levels of laser and CSC yielded a high degree of reshaping over an acute time period, after 14 days specimens exposed to 30 W, 40 W, 50 W retained shape better than those treated at 10 W and 20 W. The specimens exposed to 50 W with controlled CSC retained its new shape to the highest degree over all others, and thermal injury was minimal. In conclusion, combinations of laser and CSC parameters were effective and practical for the reshaping of composite cartilage grafts. Lasers Surg. PMID:18727025

  3. Selective retransplant after graft loss to nonadherence: success with a second chance.

    Science.gov (United States)

    Dunn, T B; Browne, B J; Gillingham, K J; Kandaswamy, R; Humar, A; Payne, W D; Sutherland, D E R; Matas, A J

    2009-06-01

    Nonadherence (NA) is a difficult posttransplant problem that can lead to graft loss. A retransplant is controversial because of a fear of recurrent NA. We reviewed our center's data base and identified 114 kidney recipients who lost their graft to overt NA; of this group, 35 (31%) underwent a retransplant after a thorough reevaluation. We compared this NA retransplant group to a control group of second transplant recipients who did not lose their first graft to overt NA (non-NA) (n = 552). After 8 years of follow-up, we found no significant differences between the groups in actuarial graft or patient survival rates, renal function, or the incidence of biopsy-proven chronic rejection. However, 5 of 35 (14%) NA recipients versus 10 of 552 (2%) non-NA recipients lost their retransplant to NA (p = 0.0001). Twenty of 35 (57%) of the NA group exhibited repeat NA behavior after retransplant. We conclude that prior graft loss to NA is associated with increased graft loss to NA after retransplant. However, the majority of NA retransplant recipients did well-with overall long-term outcomes similar to those of the non-NA group. With careful patient selection and aggressive intervention, prior overt NA should not be an absolute contraindication to retransplantation.

  4. Methods of Attaching or Grafting Carbon Nanotubes to Silicon Surfaces and Composite Structures Derived Therefrom

    Science.gov (United States)

    Tour, James M. (Inventor); Chen, Bo (Inventor); Flatt, Austen K. (Inventor); Stewart, Michael P. (Inventor); Dyke, Christopher A. (Inventor); Maya, Francisco (Inventor)

    2012-01-01

    The present invention is directed toward methods of attaching or grafting carbon nanotubes (CNTs) to silicon surfaces. In some embodiments, such attaching or grafting occurs via functional groups on either or both of the CNTs and silicon surface. In some embodiments, the methods of the present invention include: (1) reacting a silicon surface with a functionalizing agent (such as oligo(phenylene ethynylene)) to form a functionalized silicon surface; (2) dispersing a quantity of CNTs in a solvent to form dispersed CNTs; and (3) reacting the functionalized silicon surface with the dispersed CNTs. The present invention is also directed to the novel compositions produced by such methods.

  5. Preparation and characterization of a novel bone graft composite ...

    Indian Academy of Sciences (India)

    The biological behaviour of this natural material has. ∗. Author for correspondence (sastrytp@hotmail.com) also shown that it could be used as a bone substitute in ..... used in rabbit mandible defects (Wafaa et al 1994). Based on these studies, we have prepared the ESP–BA–G composite. The compressive strength of the ...

  6. Synthesis and characterization of chitosan-graft-poly(acrylic acid)/rice husk ash hydrogels composites

    International Nuclear Information System (INIS)

    Rodrigues, Francisco H.A.; Lopes, Gabriel V.; Pereira, Antonio G.B.; Fajardo, Andre R.; Muniz, Edvani C.

    2011-01-01

    According to environmental concerns, super absorbent hydrogel composites were synthesized based on rice husk ash (RHA), an industrial waste, and Chitosan-graft-poly(acrylic acid). The WAXS and FTIR data confirmed the syntheses of hydrogel composites. The effect of crystalline or amorphous RHA on water uptake was investigated. It was found that the RHA in crystalline form induces higher water capacity (W eq ) of composites hydrogels due to the fact that the intra-interactions among silanol groups on RHA make available new sites in the polymer matrix, which could interact to water. (author)

  7. Poly(lauryl acrylate) and poly(stearyl acrylate) grafted multiwalled carbon nanotubes for polypropylene composites

    DEFF Research Database (Denmark)

    Daugaard, Anders Egede; Jankova Atanasova, Katja; Hvilsted, Søren

    2014-01-01

    Two new polymer grafts on an industrial grade multiwalled carbon nanotube (MWCNT) were prepared through a non-oxidative pathway employing controlled free radical polymerization for surface initiated polymer grafting. After photochemical introduction of an ATRP initiator onto the MWCNT......, polymerizations of lauryl or stearyl acrylate were performed, resulting in two novel polymer modifications on the MWCNT (poly(lauryl acrylate) or poly(stearyl acrylate)). The method was found to give time dependent loading of polymers as a function of time (up to 38 wt% for both acrylates), and showed a plateau...... in loading after 12 h of polymerization. The modified nanomaterials were melt mixed into polypropylene composites with very low filler loading (0.3 wt%), whereafter both the thermal and electrical properties were investigated by DSC and dielectric resonance spectroscopy. The electrical properties were found...

  8. Resin selection criteria for tough composite structures

    Science.gov (United States)

    Chamis, C. C.; Smith, G. T.

    1983-01-01

    Resin selection criteria are derived using a structured methodology consisting of an upward integrated mechanistic theory and its inverse (top-down structured theory). These criteria are expressed in a "criteria selection space" which are used to identify resin bulk properties for improved composite "toughness". The resin selection criteria correlate with a variety of experimental data including laminate strength, elevated temperature effects and impact resistance.

  9. The composite of bone marrow concentrate and PRP as an alternative to autologous bone grafting.

    Directory of Open Access Journals (Sweden)

    Mohssen Hakimi

    Full Text Available One possible alternative to the application of autologous bone grafts represents the use of autologous bone marrow concentrate (BMC. The purpose of our study was to evaluate the potency of autologous platelet-rich plasma (PRP in combination with BMC. In 32 mini-pigs a metaphyseal critical-size defect was surgically created at the proximal tibia. The animals were allocated to four treatment groups of eight animals each (1. BMC+CPG group, 2. BMC+CPG+PRP group, 3. autograft group, 4. CPG group. In the BMC+CPG group the defect was filled with autologous BMC in combination with calcium phosphate granules (CPG, whereas in the BMC+CPG+PRP group the defect was filled with the composite of autologous BMC, CPG and autologous PRP. In the autograft group the defect was filled with autologous cancellous graft, whereas in the CPG group the defect was filled with CPG solely. After 6 weeks radiological and histomorphometrical analysis showed significantly more new bone formation in the BMC+CPG+PRP group compared to the BMC+CPG group and the CPG group. There were no significant differences between the BMC+CPG+PRP group and the autograft group. In the PRP platelets were enriched significantly about 4.7-fold compared to native blood. In BMC the count of mononuclear cells increased significantly (3.5-fold compared to the bone marrow aspirate. This study demonstrates that the composite of BMC+CPG+PRP leads to a significantly higher bone regeneration of critical-size defects at the proximal tibia in mini-pigs than the use of BMC+CPG without PRP. Furthermore, within the limits of the present study the composite BMC+CPG+PRP represents a comparable alternative to autologous bone grafting.

  10. The composite of bone marrow concentrate and PRP as an alternative to autologous bone grafting.

    Science.gov (United States)

    Hakimi, Mohssen; Grassmann, Jan-Peter; Betsch, Marcel; Schneppendahl, Johannes; Gehrmann, Sebastian; Hakimi, Ahmad-Reza; Kröpil, Patric; Sager, Martin; Herten, Monika; Wild, Michael; Windolf, Joachim; Jungbluth, Pascal

    2014-01-01

    One possible alternative to the application of autologous bone grafts represents the use of autologous bone marrow concentrate (BMC). The purpose of our study was to evaluate the potency of autologous platelet-rich plasma (PRP) in combination with BMC. In 32 mini-pigs a metaphyseal critical-size defect was surgically created at the proximal tibia. The animals were allocated to four treatment groups of eight animals each (1. BMC+CPG group, 2. BMC+CPG+PRP group, 3. autograft group, 4. CPG group). In the BMC+CPG group the defect was filled with autologous BMC in combination with calcium phosphate granules (CPG), whereas in the BMC+CPG+PRP group the defect was filled with the composite of autologous BMC, CPG and autologous PRP. In the autograft group the defect was filled with autologous cancellous graft, whereas in the CPG group the defect was filled with CPG solely. After 6 weeks radiological and histomorphometrical analysis showed significantly more new bone formation in the BMC+CPG+PRP group compared to the BMC+CPG group and the CPG group. There were no significant differences between the BMC+CPG+PRP group and the autograft group. In the PRP platelets were enriched significantly about 4.7-fold compared to native blood. In BMC the count of mononuclear cells increased significantly (3.5-fold) compared to the bone marrow aspirate. This study demonstrates that the composite of BMC+CPG+PRP leads to a significantly higher bone regeneration of critical-size defects at the proximal tibia in mini-pigs than the use of BMC+CPG without PRP. Furthermore, within the limits of the present study the composite BMC+CPG+PRP represents a comparable alternative to autologous bone grafting.

  11. Generalisability of a composite student selection programme

    DEFF Research Database (Denmark)

    O'Neill, Lotte Dyhrberg; Korsholm, Lars; Wallstedt, Birgitta

    2009-01-01

    OBJECTIVES The reliability of individual non-cognitive admission criteria in medical education is controversial. Nonetheless, non-cognitive admission criteria appear to be widely used in selection to medicine to supplement the grades of qualifying examinations. However, very few studies have...... examined the overall test generalisability of composites of non-cognitive admission variables in medical education. We examined the generalisability of a composite process for selection to medicine, consisting of four variables: qualifications (application form information); written motivation (in essay...... format); general knowledge (multiple-choice test), and a semi-structured admission interview. The aim of this study was to estimate the generalisability of a composite selection. METHODS: Data from 307 applicants who participated in the admission to medicine in 2007 were available for analysis. Each...

  12. Synthesis of benzimidazole-grafted graphene oxide/multi-walled carbon nanotubes composite for supercapacitance application

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, Rajesh Kr., E-mail: r05bhu@gmail.com [Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 637371 Singapore (Singapore); Xingjue, Wang [Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 637371 Singapore (Singapore); Kumar, Vinod [Department of Zoology, Banaras Hindu University, Varanasi (India); Srivastava, Anchal [Department of Physics, Banaras Hindu University, Varanasi (India); Singh, Vidya Nand [CSIR-National Physical Laboratory, New Delhi (India)

    2014-11-05

    Highlights: • We are reporting supercapacitance performance of BI-GO/MWCNTs composite. • The specific capacitance of BI-GO/MWCNTs is 275 and 460 F/g at 200 and 5 mV/s scan rate. • This composite has shown 224 F/g capacitance after 1300 cycles at 200 mV/s scan rate. - Abstract: We are reporting the fabrication, characterizations and supercapacitance performance of benzimidazole-grafted graphene oxide/multi-walled carbon nanotubes (BI-GO/MWCNTs) composite. The synthesis of BI-GO materials involves cyclization reaction of carboxylic groups on GO among the hydroxyl and amino groups on o-phenylenediamine. The BI-GO/MWCNTs composite has been fabricated via in situ reduction of BI-GO using hydrazine in presence of MWCNTs. Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), Raman spectroscopy, X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) have been used to characterize its surface and elemental composition. The uniform dispersion of MWCNTs with BI-GO helps to improve the charge transfer reaction during electrochemical process. The specific capacitance of BI-GO/MWCNTs composite is 275 and 460 F/g at 200 and 5 mV/s scan rate in 1 mol/L aqueous solution of H{sub 2}SO{sub 4}. This BI-GO/MWCNTs composite has shown 224 F/g capacitance after 1300 cycles at 200 mV/s scan rate, which represents its good electrochemical stability.

  13. Preparation of Arsenic Selective Polymeric Adsorbent by Modification of Radiation Grafted Glycidyl Methacrylate (GMA) Nonwoven Fibers

    International Nuclear Information System (INIS)

    Kavakli, C.

    2006-01-01

    It is well known that arsenic is a hazardous element for the environment. It can originate either from anthropogenic activities (pesticides, wood preservatives, mining activities, and electronic industry) or from natural erosion of arsenic containing rocks. Arsenic is highly toxic and is a carcinogenic element that exists predominantly in the form of oxyanions in the aquatic environment and has become a worldwide environmental issue. Thus, arsenic removal from industrial effluents, groundwater, and even drinking water systems has become very important. At present, the WHO guideline value, the EC maximum admissible concentration, and the USEPA limit for As in drinking water is 10 μg/L. Various treatment processes such as precipitation, adsorption onto activated alumina, reverse osmosis and ion exchange have been reported in the literature to remove arsenic from aquatic environment. Recently, polymer ligand exchanger (PLE) adsorbents have been found as one of the most promising materials for arsenic removal due to their high adsorption capacity and selectivity at low concentrations. The objective of this research was to develop a novel PLE adsorbent by radiation-induced graft polymerization so as to achieve very low level of arsenic in aqueous solutions. For this purpose, GMA was grafted onto polypropylene coated polyethylene nonwoven fabrics in emulsion system by using radiation induced graft polymerization. For the preparation of GMA grafted fabric, the trunk PE/PP nonwoven fabric was irradiated by electron beam. After irradiation process, GMA was grafted onto irradiated nonwoven fabric under nitrogen atmosphere. In order to prepare fibrous PLE adsorbent for the removal of arsenic, grafted GMA was first modified with dipicolylamine. Maximum modification was obtained in 15 % (w/w) dipicolylamine solution. Then, PLE adsorbent was loaded with Cu 2 + ions. High copper ion loading was observed for PLE fibers. Column mode adsorption studies were conducted with copper

  14. Evaluation of moxifloxacin-hydroxyapatite composite graft in the regeneration of intrabony defects: A clinical, radiographic, and microbiological study

    Directory of Open Access Journals (Sweden)

    Y V Nagarjuna Reddy

    2016-01-01

    Full Text Available Background: The formation of new connective periodontal attachment is contingent upon the elimination or marked reduction of pathogens at the treated periodontal site. An anti-microbial agent, i.e. moxifloxacin has been incorporated into the bone graft to control infection and facilitate healing during and after periodontal therapy. Materials and Methods: By purposive sampling, 15 patients with at least two contralateral vertical defect sites were selected. The selected sites in each individual were divided randomly into test and control sites according to split-mouth design. Test site received moxifloxacin-hydroxyapatite composite graft and control site received hydroxyapatite-placebo gel composite graft. Probing depth (PD and Clinical attachment level (CAL were assessed at baseline, 3, 6, 9, and 12 months. Bone probing depth (BPD and hard tissue parameters such as amount of defect fill, percentage of defect fill, and changes in alveolar crest were assessed at baseline, 6, and 12 months. Changes in subgingival microflora were also assessed by culturing the subgingival plaque samples at baseline and at 3-month follow-up. The clinical, radiographic, and microbiological data obtained were subjected to statistical analysis using descriptive statistics, paired sample t-test, independent t-test, and contingency test. Results: On intragroup comparison at test and control sites, there was a significant improvement in all clinical and radiographic parameters. However, on intergroup comparison of the same, there was no statistically significant difference between test and control sites at any interval. Although test sites showed slightly higher amount of bone fill, it was not statistically significant. There was a significant reduction in the counts of Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis at both sites from baseline to 3 months. In addition, there was a significant reduction at test sites as compared to control sites at 3

  15. Cooling Composite Graft for Distal Finger Amputation: A Reliable Alternative to Microsurgery Implantation.

    Science.gov (United States)

    Idone, Francesco; Sisti, Andrea; Tassinari, Juri; Nisi, Giuseppe

    2016-01-01

    Finger amputations are the most common injuries to the upper limb. There are many options in the management of fingertip or finger amputations. We report our experience using cooling composite graft (Hirase technique) for distal finger amputation, as alternative to microsurgery implantation. We collected a case series of eight patients and report on the clinical outcomes after a 10-month follow-up period. The amputated part survived almost completely in six patients; in these cases, the fingertip amputations were classified, according to the Allen classification, as level I in two cases, level II in three cases and level III in one case. Re-implantation of an amputated finger with the Hirase technique is possible and can provide good distal soft-tissue coverage and recovery of sensory and motor functions. We believe that re-attachment of the amputated portion as a composite graft represents an important alternative to microsurgery. Copyright © 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  16. The effects of physico-chemical interactions and polymer grafting on interfacial adhesion in thermoplastic composites

    Science.gov (United States)

    Raghavendra, Venkat Krishna

    The effects of physico-chemical interactions between the carbon fiber and Bisphenol-A polycarbonate matrix was investigated to understand the factors governing the interfacial adhesion in thermoplastic matrix composites. It was found that, the changes in the amount of oxygen functionality achieved through electrochemical oxidative surface treatment of the carbon fibers didn't affect the level of adhesion, indicating negligible polar and hydrogen bond formation. Composites fabricated from these fibers that were subsequently passivated through thermal hydrogenation up to 1000°C, which removed all the oxygen functionality without affecting the fiber topography, indicated that the mechanical interlocking between the fiber and the matrix didn't have a strong influence on the interfacial adhesion. Grafting low molecular weight BPA-PC and high molecular weight PMMA on to the fiber surface improved the interfacial adhesion. However, the level of improvement was observed to be independent of the fiber surface treatment and the molecular weight of the grafted chains. These results are consistent with the cohesive zone models proposed for the chain pull out and chain scission observed in block copolymers.

  17. Composition and distribution of phytochemicals among selected ...

    African Journals Online (AJOL)

    This study assessed the composition and distribution of phytochemicals (PC) amongst selected mangrove species' woods in Elechi Creek located behind Rivers State University of Science and Technology, Port Harcourt, Rivers State using crude methanol extract and partitioned fractions for screening the presence of PC.

  18. Mutual irradiation grafting on indigenous aramid fiber-3 in diethanolamine and epichlorohydrin and its effect on interfacially reinforced epoxy composite

    Energy Technology Data Exchange (ETDEWEB)

    Xing, Lixin [School of Chemical Engineering and Technology, Harbin Institute of Technology, Harbin 150001,China (China); Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA 16802 (United States); Liu, Li, E-mail: liuli@hit.edu.cn [School of Chemical Engineering and Technology, Harbin Institute of Technology, Harbin 150001,China (China); Xie, Fei [School of Chemical Engineering and Technology, Harbin Institute of Technology, Harbin 150001,China (China); Huang, Yudong [School of Chemical Engineering and Technology, Harbin Institute of Technology, Harbin 150001,China (China); State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150001 (China)

    2016-07-01

    Highlights: • High energy gamma rays were used to decorate the surface of aramid fiber via mutual irradiation grafting process in two medium. • The effects of different grafting medium on aramid fiber surface were investigated through SEM, AFM, XPS, wettability and adsorption measurements. • Interfacial properties of aramid reinforced polymer composites were remarkable improved after mutual irradiation. - Abstract: The surface of indigenous aramid fiber-3 (IAF3) was decorated via mutual irradiation grafting process in diethanolamine (DEA) and epichlorohydrin (ECH), respectively, with the assist of high energy gamma rays. This modification method with great permeability produced the homogeneous and ameliorative AF3 surfaces, which were observed by the scanning electron microscopy (SEM) and atom forced microscopy (AFM). Enhanced surface free energy and reduced contact angles of irradiated AF3 verified the fabulous effectiveness of mutual irradiation without seriously injured tensile strength. The composites based on epoxy resin (ER) polymer as the matrix and irradiated IAF3 grafted DEA and ECH as the reinforcement. By capitalizing on the irradiated IAF3 which has higher wettability and adsorption on resin, the irradiated IAF3-ECH/ER composites exhibit admirable interfacial mechanical performance as compared to the pristine IAF3 contained composites. The interfacial shear strength (IFSS), interlaminar shear strength (ILSS) and flexural strength of composites were remarkable improved to 86.5, 60.13 and 511 MPa respectively, from the pristine IAF3/ER composite with IFSS of 65.9 MPa, ILSS of 48.1 MPa, and flexural strength of 479 MPa.

  19. Mutual irradiation grafting on indigenous aramid fiber-3 in diethanolamine and epichlorohydrin and its effect on interfacially reinforced epoxy composite

    International Nuclear Information System (INIS)

    Xing, Lixin; Liu, Li; Xie, Fei; Huang, Yudong

    2016-01-01

    Highlights: • High energy gamma rays were used to decorate the surface of aramid fiber via mutual irradiation grafting process in two medium. • The effects of different grafting medium on aramid fiber surface were investigated through SEM, AFM, XPS, wettability and adsorption measurements. • Interfacial properties of aramid reinforced polymer composites were remarkable improved after mutual irradiation. - Abstract: The surface of indigenous aramid fiber-3 (IAF3) was decorated via mutual irradiation grafting process in diethanolamine (DEA) and epichlorohydrin (ECH), respectively, with the assist of high energy gamma rays. This modification method with great permeability produced the homogeneous and ameliorative AF3 surfaces, which were observed by the scanning electron microscopy (SEM) and atom forced microscopy (AFM). Enhanced surface free energy and reduced contact angles of irradiated AF3 verified the fabulous effectiveness of mutual irradiation without seriously injured tensile strength. The composites based on epoxy resin (ER) polymer as the matrix and irradiated IAF3 grafted DEA and ECH as the reinforcement. By capitalizing on the irradiated IAF3 which has higher wettability and adsorption on resin, the irradiated IAF3-ECH/ER composites exhibit admirable interfacial mechanical performance as compared to the pristine IAF3 contained composites. The interfacial shear strength (IFSS), interlaminar shear strength (ILSS) and flexural strength of composites were remarkable improved to 86.5, 60.13 and 511 MPa respectively, from the pristine IAF3/ER composite with IFSS of 65.9 MPa, ILSS of 48.1 MPa, and flexural strength of 479 MPa.

  20. Validity of exploration for suitable vessels for replantation in the distal fingertip amputation in early childhood: replantation or composite graft.

    Science.gov (United States)

    Imaizumi, Atsushi; Ishida, Kunihiro; Arashiro, Ken; Nishizeki, Osamu

    2013-09-01

    Composite grafting, grafting without microvascular anastomoses, has been widely performed for distal fingertip amputation in children with variable results, whereas successful replantation of these amputations using microsurgical technique has been reported. However, most of these reports included a wide age-range and a mix of different amputation levels. This study reviewed our cases of paediatric digital amputation, in order to verify the value of distal fingertip replantation over composite grafting, especially in early childhood. Seventeen young children (aged 3 years and 8 months on average), with single-digit fingertip amputations in Tamai zone I were reviewed from 1993-2008. Each amputation was subdivided into three types: distal, middle, and proximal. There were three distal, 13 middle, and one proximal type zone I amputations. All were crush or avulsion injuries. All three distal-type cases were reattached as primary composite grafts with one success. For middle-type cases, the survival rate of primary composite graft without exploration for possible vessels for anastomosis was 57%. On exploration, suitable vessels for anastomosis were found 50% of the time, in which all replantations were succeeded. The remaining cases were reattached as secondary composite grafts, with one success using the pocket method. Consequently, the success rate after exploration was 67%. The only one proximal-type amputation was failed in replantation. For the middle-type zone I amputation in early childhood, replantation has a high success rate if suitable vessels can be found. Therefore, exploration is recommended for amputations at this level with a view to replantation, irrespective of the mechanism of injury.

  1. Morphological and mechanical characterization of chitosan-calcium phosphate composites for potential application as bone-graft substitutes

    Directory of Open Access Journals (Sweden)

    Guilherme Maia Mulder van de Graaf

    Full Text Available Introduction: Bone diseases, aging and traumas can cause bone loss and lead to bone defects. Treatment of bone defects is challenging, requiring chirurgical procedures. Bone grafts are widely used for bone replacement, but they are limited and expensive. Due to bone graft limitations, natural, semi-synthetic, synthetic and composite materials have been studied as potential bone-graft substitutes. Desirable characteristics of bone-graft substitutes are high osteoinductive and angiogenic potentials, biological safety, biodegradability, bone-like mechanical properties, and reasonable cost. Herein, we prepared and characterized potential bone-graft substitutes composed of calcium phosphate (CP - a component of natural bone, and chitosan (CS - a biocompatible biopolymer. Methods CP-CS composites were synthetized, molded, dried and characterized. The effect of drying temperatures (38 and 60 °C on the morphology, porosity and chemical composition of the composites was evaluated. As well, the effects of drying temperature and period of drying (3, 24, 48 and 72 hours on the mechanical properties - compressive strength, modulus of elasticity and relative deformation-of the demolded samples were investigated. Results Scanning electron microscopy and gas adsorption-desorption analyses of the CS-CP composites showed interconnected pores, indicating that the drying temperature played an important role on pores size and distribution. In addition, drying temperature have altered the color (brownish at 60 °C due to Maillard reaction and the chemical composition of the samples, confirmed by FTIR. Conclusion Particularly, prolonged period of drying have improved mechanical properties of the CS-CP composites dried at 38 °C, which can be designed according to the mechanical needs of the replaceable bone.

  2. Chromatographic study of the conformational behavior of graft copolymers with a broad distribution of grafting densities in dilute solutions in selective solvents for grafts

    Czech Academy of Sciences Publication Activity Database

    Netopilík, Miloš; Janata, Miroslav; Svitáková, Romana; Trhlíková, Olga; Berek, D.; Macova, E.; Limpouchová, Z.; Procházka, K.

    2016-01-01

    Roč. 39, č. 1 (2016), s. 50-58 ISSN 1082-6076 R&D Projects: GA ČR(CZ) GA13-02938S Grant - others:OPPK(XE) CZ.2.16/3.1.00/24504 Institutional support: RVO:61389013 Keywords : interaction chromatography * size exclusion chromatography * poly(4-methylstyrene)-graft-poly(2-vinylpyridine) Subject RIV: CD - Macromolecular Chemistry Impact factor: 0.697, year: 2016

  3. Comparison of fractional flow reserve of composite Y-grafts with saphenous vein or right internal thoracic arteries.

    Science.gov (United States)

    Glineur, David; Boodhwani, Munir; Poncelet, Alain; De Kerchove, Laurent; Etienne, Pierre Yves; Noirhomme, Philippe; Deceuninck, Paul; Michel, Xavier; El Khoury, Gebrine; Hanet, Claude

    2010-09-01

    Composite Y-grafts, using the left internal thoracic artery as the inflow, allow a more efficient use of conduits without the need to touch a diseased ascending aorta. Among other conduits, the saphenous vein graft may be an alternative to the radial artery in elderly patients. We evaluated the hemodynamic characteristics of 17 composite Y-grafts made with the left internal thoracic artery anastomosed to the left anterior descending coronary artery in all cases and with either the free right internal thoracic artery (RITA group, n = 10) or a saphenous vein graft (SVG group, n = 7) implanted proximally to the left internal thoracic artery and distally to the circumflex territory 6 months after the operation. At baseline, the pressure gradient measured with a 0.014-inch pressure wire was minimal between the aorta and the internal thoracic artery stem (2 +/- 1 mm Hg), the internal thoracic artery and left anterior descending (4 +/- 2 mm Hg), the internal thoracic artery and left circumflex (3 +/- 1 mm Hg), and the saphenous vein graft and left circumflex (2 +/- 2 mm Hg). During hyperemia induced by adenosine, the pressure gradient increased significantly to 6 +/- 2 mm Hg in the internal thoracic artery stem, 9 +/- 4 mm Hg in the internal thoracic artery and left anterior descending artery, 9 +/- 3 mm Hg in the internal thoracic artery and left circumflex, and 7 +/- 4 mm Hg in the saphenous vein graft and left circumflex. Fractional flow reserve was 0.94 +/- 0.02 in internal thoracic artery stem, 0.90 +/- 0.04 mm Hg in the internal thoracic artery and left anterior descending, 0.91 +/- 0.03 mm Hg in the internal thoracic artery and left circumflex, and 0.92 +/- 0.06 mm Hg in the saphenous vein graft and left circumflex. No difference between the two types of composite Y-grafts was observed for pressure gradients or fractional flow reserve measured in internal thoracic artery stem or in distal branches. Composite Y-grafts with saphenous vein or right internal thoracic

  4. Establishment of a clonal bank of Caesalpinia spinosa (Mol. O. Kuntz by selection of plus trees and grafting

    Directory of Open Access Journals (Sweden)

    Jenny E Nuñez

    2017-03-01

    Full Text Available In Ecuador, plant propagation techniques are not available commercially to establish clonal banks of Caesalpinia spinosa (Mol. O. Kuntz (guarango plus trees, which limits the development of in vitro propagation protocols of this specie. The objective of the present work was to establish a clonal bank of C. spinosa by selecting plus trees and grafting. Guarango trees belonging to the province of Chimborazo, Guano canton were selected based on total height, height at the beginning of the crown, height of crown, crown surface, crown symmetry, flowering, fruit production and content of tannins in the pod. The patron plants to make the grafts were obtained from scarified seeds, soaked for 48 hours at room temperature and planted in beds of 1.0 x 3.0 m. At 40 days, the seedlings were transplanted into pockets and at 16 months the grafts were made in the patron plants. Three types of graft were used (simple slit in the patron, single slit in the spike and bud grafting. For each, 100 patron were used. Of the eight trees plus collected in the field, the ecotype CHSt03 was used to make the grafts. It was showed the highest total height (6.6m, height at the beginning of the cup (2.2m, cup surface (> 70%, cup volume (> 10%, cup symmetry (1, fruit (40kg / tree and total polyphenol content in pods (5870 μgEAGgMS-1. The graft by simple slit in the patron had the highest stuck percentage (80%. These results allowed to establish a clonal bank of 80 plants grafted of C. spinosa of the ecotype CHSt03, which establish the bases to develop protocols for in vitro propagation of this forest species, native of Ecuador.   Keywords: biodiversity, biotechnology, forestry, industry, tannins

  5. Oleic acid-grafted chitosan/graphene oxide composite coating for corrosion protection of carbon steel.

    Science.gov (United States)

    Fayyad, Eman M; Sadasivuni, Kishor Kumar; Ponnamma, Deepalekshmi; Al-Maadeed, Mariam Al Ali

    2016-10-20

    An anticorrosion coating film based on the formation of nanocomposite coating is reported in this study. The composite consisted of chitosan (green matrix), oleic acid, and graphene oxide (nano filler). The nanocomposite coating was arranged on the surface of carbon steel, and the corrosion resistance was monitored using electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PP). Compared to the pure chitosan (CS) coating, the corrosion resistance of oleic acid-modified chitosan/graphene oxide film (CS/GO-OA) is increased by 100 folds. Since the well-dispersed smart grafted nanolayers delayed the penetration rate of corrosive species and thus maintained long term anticorrosive stability which is correlated with hydrophobicity and permeability. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Comparative Efficacies of Collagen-Based 3D Printed PCL/PLGA/β-TCP Composite Block Bone Grafts and Biphasic Calcium Phosphate Bone Substitute for Bone Regeneration.

    Science.gov (United States)

    Hwang, Kyoung-Sub; Choi, Jae-Won; Kim, Jae-Hun; Chung, Ho Yun; Jin, Songwan; Shim, Jin-Hyung; Yun, Won-Soo; Jeong, Chang-Mo; Huh, Jung-Bo

    2017-04-17

    The purpose of this study was to compare bone regeneration and space maintaining ability of three-dimensional (3D) printed bone grafts with conventional biphasic calcium phosphate (BCP). After mixing polycaprolactone (PCL), poly (lactic-co-glycolic acid) (PLGA), and β-tricalcium phosphate (β-TCP) in a 4:4:2 ratio, PCL/PLGA/β-TCP particulate bone grafts were fabricated using 3D printing technology. Fabricated particulate bone grafts were mixed with atelocollagen to produce collagen-based PCL/PLGA/β-TCP composite block bone grafts. After formation of calvarial defects 8 mm in diameter, PCL/PLGA/β-TCP composite block bone grafts and BCP were implanted into bone defects of 32 rats. Although PCL/PLGA/β-TCP composite block bone grafts were not superior in bone regeneration ability compared to BCP, the results showed relatively similar performance. Furthermore, PCL/PLGA/β-TCP composite block bone grafts showed better ability to maintain bone defects and to support barrier membranes than BCP. Therefore, within the limitations of this study, PCL/PLGA/β-TCP composite block bone grafts could be considered as an alternative to synthetic bone grafts available for clinical use.

  7. Grafting methyl acrylic onto carbon fiber via Diels-Alder reaction for excellent mechanical and tribological properties of phenolic composites

    Science.gov (United States)

    Fei, Jie; Duan, Xiao; Luo, Lan; Zhang, Chao; Qi, Ying; Li, Hejun; Feng, Yongqiang; Huang, Jianfeng

    2018-03-01

    Carbon fibers (CFs) were grafted with methyl acrylic via Diels-Alder reaction at the different oil bath temperature effectively creating a carboxyl functionalized surface. The effect of grafting temperature on the surface morphology and functional groups of carbon fibers were investigated by FTIR, Raman spectroscopy, XPS and SEM respectively. The results showed that the optimal grafting temperature was 80 °C, and the relative surface coverage by carboxylic acid groups increased from an initial 5.16% up to 19.30% significantly improved the chemical activity without damaging the skin and core region of the carbon fibers. Mechanical property tests indicated that the shear and tensile strength of the sample with the grafting temperature of 80 °C (CFRP-3) increased obviously by 90.3% and 78.7%, respectively, compared with the pristine carbon fibers reinforced composite. Further, the sample CFRP-3 exhibited higher and more stable friction coefficient and improved wear resistance, while the wear rate decreased 52.7%, from 10.8 × 10-6 to 5.1 × 10-6 mm3/N m. The present work shows that grafting methyl acrylic via Diels-Alder reaction could be a highly efficient and facile method to functionalize carbon fibers for advanced composites.

  8. Unexpected Radiation-Induced Aortic Wall Thickening Requiring Composite Graft Technique during Off-Pump Coronary Artery Bypass Grafting

    Directory of Open Access Journals (Sweden)

    Paola Redaelli

    2017-01-01

    Full Text Available Mediastinal radiation is commonly used to treat Hodgkin’s and non-Hodgkin’s lymphoma, lung and breast cancer. Cardiac complications after radiation therapy are well described, although rare. A large spectrum of injuries can occur, causing long term morbidity among survivors. We describe a case of post-actinic ascending aortic wall thickening that prevented saphenous vein proximal anastomosis and was successfully managed with aortic no-touch off-pump coronary artery bypass grafting (OPCAB, 25 years after radiation therapy for Hodgkin’s lymphoma.

  9. Sensing of environmental pollutant by conductive composite from prepared from hyperbranched polymer-grafted carbon black and crystalline polymer

    International Nuclear Information System (INIS)

    Taniguchi, Y.; Chen, J.; Ogawa, M.; Yokoyama, K.; Shimizu, H.; Tsubokawa, N.; Maekawa, Y.; Yoshida, M.

    2002-01-01

    Complete text of publication follows. The hyperbranched (HB) polymer-grafted (PG) carbon blacks (CB) have the possibility of utilizing as a support of catalyst and enzyme, and a curing agent of epoxy resin, because they have much terminal amino or hydroxyl groups. The postgrafting of crystalline polymer onto HB PG CB and the sensing of environmental pollutant by the conductive composite prepared from the polymer-postgrafted CB was discussed. The grafting of poly(amidoamide) onto CB surface was achieved by repeating either Michael addition of methyl acrylate to amino group on the surface or the amidation of the resulting terminal methyl ester group with ethylene diamine. HB polyester onto CB surface was grafted by stepwise growth of 2,2-bis(hydroxymethyl)propionic acid (bis-MPA) from surface carboxyl and hydroxyl groups on CB as a core in the presence of p-toluenesulfonic acid (p-TSA). The one-pot grafting of HB polyester onto CB as core was also achieved by the polycondensation of bis-MPA in the presence of p-TSA. Postgrafting of crystalline polymer onto HB polymer-grafted CB was achieved by the reaction of terminal amino or hydroxyl groups of grafted chain with COCl-terminated crystalline polymer. The electric resistance of the composite prepared from crystalline polymer-postgrafted CB was found to increase drastically in hexane, containing environmental pollutant, such as chloroform and trichloroethane, and returned immediately to the initial resistance when it was transferred into pure hexane. Based on the above results, it is concluded that the composite can be used as a novel sensor for environmental pollutant in solution

  10. In situ comparison of varying composite tibial tunnel interference screws used for ACL soft tissue graft fixation.

    Science.gov (United States)

    Nyland, John; Krupp, Ryan; Greene, Joe; Bowles, Richard; Burden, Robert; Caborn, David N M

    2015-12-01

    This mechanical study using an in vitro porcine model compared composite interference screw fixation of soft tissue ACL grafts in tibial tunnels. Forty-eight porcine profundus tendons and tibiae were divided into four groups of 12 closely matched specimens. Equivalent diameter grafts were assigned to each group. Tibial bone tunnels were drilled to 0.5mm greater than graft diameter. Grafts were fixed in tunnels using one 10 × 35 mm composite interference screw designed by four different manufacturers. Maximal insertion torque and perceived within group mechanical testing outcome predictions were recorded. Constructs were potted and loaded into a six degrees of freedom clamp that placed the servohydraulic device tensile loading vector in direct tunnel alignment. Constructs were pre-loaded to 25 N, pre-conditioned between 0 and 50 N for 10 cycles (0.5 Hz), submaximally tested between 50 and 250 N for 500 cycles (one hertz) and load to failure tested at 20mm/min. Statistically significant differences were not observed between groups for displacement during submaximal cyclic loading, yield load, displacement at yield load, stiffness, ultimate load at failure and displacement at ultimate load. One composite screw group displayed a slightly greater proportion of specimens that required use of more than one screw during insertion. Under highly controlled conditions groups displayed comparable fixation. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Graft and Corruption Practices Among Selected Public Officials in Mindanao, Southern Philippines

    Directory of Open Access Journals (Sweden)

    Amer Husain L. Laut

    2013-08-01

    Full Text Available This study aims to examine the graft and corruption practices among selected public officials in southern Philippines. The study is qualitative in nature making use of case study method in which an in-depth analysis of primary data obtained from eight informants, four of whom are town mayors and their four incumbent municipal treasurers, is employed. The findings revealed that the mayor informants got elected through vote buying and bribery. Politics and family matters intersect as informants are supported by their families during election who used guns, gold and goons to ensure election victory. The clannish nature of the community finds expression also in the selection of relatives in municipal employment and in accessing municipal resources. The most prevalent corruption practice disclosed by the informants is amassing the internal revenue allotment (IRA for personal purposes in order to recover the huge amount of money spent during election. Other types of corruption practices also include falsification of documents, nepotism, bribery, kickbacks, and evasion of public bidding. These public officials also do not seem to perform official duties in their towns as they live outside of their municipalities. Inter-agency involvement of corruption among different government agencies in the areas studied are also uncovered. Moreover, the perceived negative effects of corruption are manifested in the poor delivery of the community’s basic social services in health, water supply, education, and security protection. Corruption also adversely affects the construction of community infrastructure facilities and the establishment of an equitable and solid economic base. The study has implications to the strict policy implementation of the provisions of the 1991 Local Government Code of the Philippines, The Anti-Graft and Corrupt Practices Act, and other pertinent laws in order to improve the transparency, integrity and accountability of public officials

  12. BenzoDODA grafted polymeric resin—Plutonium selective solid sorbent

    Energy Technology Data Exchange (ETDEWEB)

    Ruhela, R., E-mail: riteshr@barc.gov.in [Materials Processing Division, Materials Group, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Panja, S., E-mail: surajit@barc.gov.in [Fuel Reprocessing Division, Nuclear Fuels Group, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Singh, A.K. [Materials Processing Division, Materials Group, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Dhami, P.S.; Gandhi, P.M. [Fuel Reprocessing Division, Nuclear Fuels Group, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India)

    2016-11-15

    Highlights: • BenzoDODA grafted polymeric resin was synthesized and evaluated for sorption of Pu(IV). • Fast sorption kinetics for ‘Pu(IV)’. • Ease of back extraction of ‘Pu’ form loaded resin. • Ease of recyclability and fair stability in HNO{sub 3} medium. - Abstract: A new ligand grafted polymeric resin (BenzoDODA SDVB) was synthesized by covalently attaching plutonium selective ligand (BenzoDODA) on to styrene divinyl benzene (SDVB) polymer matrix. BenzoDODA SDVB resin was evaluated for separation and recovery of plutonium(IV) from nitric acid medium. Sorption of Pu(IV) was found to decrease with the increase in nitric acid concentration, with very small sorption above 7.0 M HNO{sub 3}. Sorption kinetics was fast enough to achieve the equilibrium within 60 min of contact where the kinetic data fitted well to pseudo-second-order model. Sorption isotherm data fitted well to Langmuir model suggesting chemical interaction between the BenzoDODA moiety and plutonium(IV) ions. Sorption studies with some of representative radionuclides of high level waste showed that BenzoDODA SDVB is selective and therefore could be a promising solid sorbent for separation and recovery of plutonium. Further, the theoretical calculations done on BenzoDODA SDVB resin suggested Pu(NO{sub 3}){sub 4}·BenzoDODA (1:1) sorbed complex conformed to generally observed square antiprism geometry of the plutonium complexes, with contributions from oxygen atoms of four nitrate ions as well as from four oxygen atoms present in BenzoDODA (two phenolic ether oxygen atoms and two carbonyl oxygen atoms of amidic moiety).

  13. Body composition estimation from selected slices

    DEFF Research Database (Denmark)

    Lacoste Jeanson, Alizé; Dupej, Ján; Villa, Chiara

    2017-01-01

    Background Estimating volumes and masses of total body components is important for the study and treatment monitoring of nutrition and nutrition-related disorders, cancer, joint replacement, energy-expenditure and exercise physiology. While several equations have been offered for estimating total...... the whole-body composition volume and mass from areas measured in selected slices were modeled with ordinary least squares (OLS) linear regressions and support vector machine regression (SVMR). Results and Discussion The best predictive equation for total body AT volume was based on the AT area of a single...

  14. Synthesis and Characterization of Styrene- Ethylene-Propylene-Styrene (SEPS) Grafted with Maleic Anhydride (MAH) for Use as Coupling Agent in Wood Polymer Composite

    OpenAIRE

    M. Acevedo-Morantes; A. Tapia; J. Correa; A. Realpe-Jimenez; C. Gartner

    2015-01-01

    Styrene-Ethylene-Propylene-Styrene (SEPS) block copolymer was grafted with maleic anhydride (MAH) by reactive extrusion (SEPS-g-MAH) using an organic peroxide as initiator in the grafting. SEPS-g-MAH was synthesized for use as coupling agent in wood polymer composite (WPC). Identification of this compatibilizer was made using Fourier transform infrared spectroscopy (FTIR) and the grafting degree was determinate with titration. The characteristic peaks in FTIR analysis indicated the presence o...

  15. Enhanced thermal and mechanical properties of epoxy composites by mixing thermotropic liquid crystalline epoxy grafted graphene oxide

    Directory of Open Access Journals (Sweden)

    B. Qi

    2014-07-01

    Full Text Available Graphene oxide (GO sheets were chemically grafted with thermotropic liquid crystalline epoxy (TLCP. Then we fabricated composites using TLCP-g-GO as reinforcing filler. The mechanical properties and thermal properties of composites were systematically investigated. It is found that the thermal and mechanical properties of the composites are enhanced effectively by the addition of fillers. For instance, the composites containing 1.0 wt% of TLCP-g-GO present impact strength of 51.43 kJ/m2, the tensile strength of composites increase from 55.43 to 80.85 MPa, the flexural modulus of the composites increase by more than 48%. Furthermore, the incorporation of fillers is effective to improve the glass transition temperature and thermal stability of the composites. Therefore, the presence of the TLCP-g-GO in the epoxy matrix could make epoxy not only stronger but also tougher.

  16. Hydroquinone and quinone-grafted porous carbons for highly selective CO2 capture from flue gases and natural gas upgrading

    NARCIS (Netherlands)

    Wang, J.; Krishna, R.; Yang, J.; Deng, S.

    2015-01-01

    Hydroquinone and quinone functional groups were grafted onto a hierarchical porous carbon framework via the Friedel-Crafts reaction to develop more efficient adsorbents for the selective capture and removal of carbon dioxide from flue gases and natural gas. The oxygen-doped porous carbons were

  17. Selective bowel decontamination in elective liver transplantation : no improvement in endotoxaemia, initial graft function and post-operative morbidity

    NARCIS (Netherlands)

    Maring, JK; Zwaveling, JH; Klompmaker, IJ; Slooff, MJH

    Peri-operative endotoxaemia during liver transplantation has been linked to compromised graft function and infection. Selective decontamination of the digestive tract (SDD) could prevent endotoxaemia by eradicating Gram-negative bacteria from the intestine. In a randomized placebo controlled study

  18. Facile synthesis of cross linked-chitosan-grafted-polyaniline composite and its Cr(VI) uptake studies.

    Science.gov (United States)

    Karthik, Rathinam; Meenakshi, Sankaran

    2014-06-01

    In the present investigation, the removal of Cr(VI) ions from aqueous solution using cross linked-chitosan-grafted-polyaniline composite (CCGP) was compared with that of chitosan-grafted-polyaniline (CGP) composite. The composites were characterized using FTIR, SEM-EDX, XRD, DSC, and TGA techniques. Batch equilibrium method was used for the optimization of various equilibrium parameters such as pH, contact time, dosage and initial Cr(VI) ion concentration. The removal efficiency by CCGP composite was found to be higher compared to CGP composite in all the studied conditions. The adsorption process was well described by Freundlich isotherm model for both the composites. The maximum adsorption capacity of CGP and CCGP composite for Cr(VI) ions was 165.6mg/g and 179.2mg/g at 303K. Thermodynamic parameters for the adsorption system were calculated and concluded that the nature of sorption was spontaneous and endothermic in nature. The Cr(VI) adsorption kinetic process was well described by pseudo-second-order kinetic model and the sorption process was being controlled by intraparticle diffusion pattern. Desorption and regeneration experiments of CGP and CCGP composites were performed and reused for more than two consecutive cycles. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Polymer grafting surface as templates for the site-selective metallization

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Fang [College of Pharmacy, Guangxi University of Chinese Medicine, Nanning 530001 (China); College of Chemistry and Life Science, Guangxi Teachers Education University, Nanning 530001 (China); Li, Peiyuan, E-mail: lipearpear@yahoo.cn [College of Pharmacy, Guangxi University of Chinese Medicine, Nanning 530001 (China); Li, Xiangcheng [School of computer, electronics and information, Guangxi University, Nanning 530001 (China); Huo, Lini [College of Pharmacy, Guangxi University of Chinese Medicine, Nanning 530001 (China); Chen, Jinhao [College of Chemistry and Life Science, Guangxi Teachers Education University, Nanning 530001 (China); Chen, Rui [College of Pharmacy, Guangxi University of Chinese Medicine, Nanning 530001 (China); Na, Wei; Tang, Wanning; Liang, Lifang [College of Chemistry and Life Science, Guangxi Teachers Education University, Nanning 530001 (China); Su, Wei, E-mail: aaasuwei@yahoo.com.cn [College of Chemistry and Life Science, Guangxi Teachers Education University, Nanning 530001 (China)

    2013-06-01

    We report a simple, low-cost and universal method for the fabrication of copper circuit patterns on a wide range of flexible polymeric substrates. This method relies on procedures to modify the polymeric substrates with grafted polymer template to form surface-bound N-containing groups, which can bind palladium catalysts that subsequently initiate the site-selective deposition of copper granular layer patterns. The fabrications of patterned copper films were demonstrated on three kinds of flexible polymeric films including poly(imide) (PI), poly(ethylene naphthalate) (PEN) and poly(ethylene terephthalate) (PET) with minimum feature sizes of 200 μm. The films were characterized by ATR FT-IR, contact angle, XPS, XRD, TEM, SEM. Furthermore, the copper layered structure shows good adhesion with polymeric film. This method, which provides a promising strategy for the fabrication of copper circuit patterns on flexible polymeric substrates, has the potential in manufacturing conductive features adopted in various fields including modern electronics, opto-electronics and photovoltaic applications.

  20. Effect of Bamboo Flour Grafted Lactide on the Interfacial Compatibility of Polylactic Acid/Bamboo Flour Composites

    Directory of Open Access Journals (Sweden)

    Xin-yu Song

    2017-07-01

    Full Text Available Bamboo flour (BF was grafted onto lactide (LA in the molten state using stannous octoate as a catalyst to form BF-g-LA. Then, polylactic acid (PLA was blended with BF (PLA/BF, 85/15 wt % to prepare PLA/BF/BF-g-LA composites using BF-g-LA as a compatibilizer. The grafting rate of BF was characterized using infrared testing and elemental analysis. To investigate the effect of BF-g-LA on the performance of PLA/BF/BF-g-LA composites, the phase morphology, thermal stability, and mechanical properties of the composites were characterized using scanning electron microscopy, thermogravimetric analysis, and universal material testing, respectively. The addition of BF-g-LA improved the interface compatibility between PLA and BF. When the BF-g-LA content was 2 phr, the tensile and impact strengths of PLA/BF/BF-g-LA composites were 55.3 MPa and 9.56 kJ/m2, representing 30% and 27% increases, respectively, relative to corresponding values for PLA/BF composites.

  1. Electrospun carboxyl multi-walled carbon nanotubes grafted polyhydroxybutyrate composite nanofibers membrane scaffolds: Preparation, characterization and cytocompatibility.

    Science.gov (United States)

    Zhijiang, Cai; Cong, Zhu; Jie, Guo; Qing, Zhang; Kongyin, Zhao

    2018-01-01

    Electrospun polyhydroxybutyrate (PHB)/carboxyl multi-walled carbon nanotubes grafted polyhydroxybutyrate (CMWCNT-g-PHB) composite nanofibers scaffolds were fabricated by electrospinning technology. The grafted product CMWCNT-g-PHB was prepared by condensation reactions between the carboxyl groups of CMWCNT and hydroxyl groups of PHB molecules and characterized by FTIR, XRD, XPS, TG and TEM measurements. The surface morphology, hydrophilicity and tensile mechanical properties of the electrospun PHB/CMWCNT-g-PHB composite nanofibers membrane scaffolds were investigated. The values of tensile strength, breaking elongation rate, initial modulus and fracture energy of the composite nanofibers scaffolds can reach to 4.64MPa, 255.59%, 88MPa and 109.73kJ/m 2 , respectively. The biodegradability and cytocompatibility of the electrospun composite nanofibers scaffolds were preliminarily evaluated. The as-prepared electrospun PHB/CMWCNT-g-PHB composite nanofibers scaffolds with the characteristics of large specific area, high porosity, good biodegradability and cytocompatibility as well as sufficient mechanical properties should be more promising in the field of tissue engineering scaffolds and biological medicine. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Initial horticultural performance of nine ‘Persian’ lime selections grafted onto Swingle citrumelo

    Directory of Open Access Journals (Sweden)

    Magno Guimarães Santos

    2016-04-01

    Full Text Available ABSTRACT ‘Persian’ lime (PL [Citrus latifolia (Yu. Tanaka Tanaka] is an important species both for domestic fresh fruit consumption in Brazil as well as the export market, since the country is one of the largest producers in the world despite the fact that, in commercial plantations, it is still not uncommon to find trees with low productivity and high plant vigor of unknown origin. Selections of Persian lime ‘CNPMF–2000’, ‘CNPMF–2001’, ‘CNPMF–01’, ‘CNPMF–02’, ‘IAC–5’, ‘IAC–5.1’, ‘Bearss’, ‘Persian–58’, and ‘5059’, were therefore grafted onto Swingle citrumelo [C. paradisi Macfad. cv. Duncan × Poncirus trifoliata (L. Raf.] rootstocks and evaluated in Cruz das Almas, Bahia, Brazil in a field experiment conducted in a completely randomized block design with five replications and two trees per plot. The biometric attributes (canopy height, diameter and volume, yield parameters (yield during the off-season harvest period, yield per plant, production efficiency, and fruit quality traits, were evaluated. The ‘CNPMF–2001’, ‘CNPMF–01’, ‘CNPMF–02’, ‘IAC–5’, and ‘Bearss’ selections had 5-11 % shorter trees than the other cultivars. ‘CNPMF–01’, ‘CNPMF–02’, ‘Persian–58’, and ‘5059’ presented higher yield efficiency values, between 3.1-3.4 kg m−3, and higher yield levels during the off-season harvest periods. The ‘Bearss’, ‘Persian–58’, ‘CNPMF–2000’, ‘IAC–5.1’ and ‘5059’ selections had more acid fruits and the latter three, smaller fruits. Based on their horticultural performance up to eight years of age, ‘CNPMF–01’, ‘CNPMF–02’, ‘Persian–58’ and ‘5059’ selections were the most promising varieties of Persian lime.

  3. Selective Grafting of Primary Amines onto Carbon Nanotubes via Free-Radical Treatment in Microwave Plasma Post-Discharge

    Directory of Open Access Journals (Sweden)

    Philippe Dubois

    2012-01-01

    Full Text Available A novel strategy to graft functional groups at the surface of carbon nanotubes (CNTs is discussed. Aiming at grafting nitrogen containing groups, and more specifically primary amine covalent functionalization, CNTs were exposed under atomic nitrogen flow arising from an Ar + N2 microwave plasma. The primary amine functions were identified and quantified through chemical derivatization with 4-(trifluoromethylbenzaldehyde and characterized through X-ray photoelectron spectroscopy. The increase of the selectivity in the primary amines grafting onto CNTs, up to 66.7% for treatment of CNT powder, was performed via the reduction of post-treatment oxygen contamination and the addition of hydrogen in the experimental set-up, more particularly in the plasma post-discharge chamber. The analyses of nitrogenated and primary amine functions grafting on the CNT surface suggest that atomic nitrogen (N• and reduced nitrogen species (NH• and NH2• react preferentially with defect sites of CNTs and, then, only atomic nitrogen continues to react on the CNT surface, creating defects.

  4. Mass selection in maize composites by means of selection indices

    NARCIS (Netherlands)

    Wolff, de F.

    1972-01-01

    General considerations

    A selection index may be applied to selection based either upon the performance of single plants or upon the performance of progenies. In the latter case however, index selection should only result in a modest gain in selection efficiency, when

  5. Hydroquinone and Quinone-Grafted Porous Carbons for Highly Selective CO2 Capture from Flue Gases and Natural Gas Upgrading.

    Science.gov (United States)

    Wang, Jun; Krishna, Rajamani; Yang, Jiangfeng; Deng, Shuguang

    2015-08-04

    Hydroquinone and quinone functional groups were grafted onto a hierarchical porous carbon framework via the Friedel-Crafts reaction to develop more efficient adsorbents for the selective capture and removal of carbon dioxide from flue gases and natural gas. The oxygen-doped porous carbons were characterized with scanning electron microscopy, transmission electron microscopy, X-ray powder diffraction, Fourier transform infrared spectroscopy, and Raman spectroscopy. CO2, CH4, and N2 adsorption isotherms were measured and correlated with the Langmuir model. An ideal adsorbed solution theory (IAST) selectivity for the CO2/N2 separation of 26.5 (298 K, 1 atm) was obtained on the hydroquinone-grafted carbon, which is 58.7% higher than that of the pristine porous carbon, and a CO2/CH4 selectivity value of 4.6 (298 K, 1 atm) was obtained on the quinone-grafted carbon (OAC-2), which represents a 28.4% improvement over the pristine porous carbon. The highest CO2 adsorption capacity on the oxygen-doped carbon adsorbents is 3.46 mmol g(-1) at 298 K and 1 atm. In addition, transient breakthrough simulations for CO2/CH4/N2 mixture separation were conducted to demonstrate the good separation performance of the oxygen-doped carbons in fixed bed adsorbers. Combining excellent adsorption separation properties and low heats of adsorption, the oxygen-doped carbons developed in this work appear to be very promising for flue gas treatment and natural gas upgrading.

  6. Biocompatible Soft Nanoparticles with Multiple Morphologies Obtained from Nanoprecipitation of Amphiphilic Graft Copolymers in a Backbone-Selective Solvent.

    Science.gov (United States)

    Le Fer, Gaëlle; Le Cœur, Clémence; Guigner, Jean-Michel; Amiel, Catherine; Volet, Gisèle

    2017-03-21

    Stealth nanocarriers are a promising technology for the treatment of diseases. However, the preparation and characterization of well-defined soft nanoparticulate systems remain challenging. Here we describe a platform of amphiphilic graft copolymers leading to nanoparticles with multiple morphologies and the role of the hydrophilic backbone in their interaction with a model protein. The amphiphilic graft copolymers platform was composed of hydrophilic backbone poly(2-methyl-2-oxazoline-co-2-pentyl-2-oxazoline) (P(MeOx-co-PentOx)), prepared via cationic ring-opening polymerization. Hydrophobic poly(d,l-lactide) (PLA) chains were grafted on the backbone via Huisgen 1,3-dipolar cycloaddition. The "click" copper-catalyzed cycloaddition reactions of azides with alkynes (CuAAC) were successfully carried out, and a series of amphiphilic copolymers were prepared containing a backbone with a number-average molecular weight of 14.2 × 10 3 g mol -1 and different hydrophobic PLA grafts with various molecular weights (2.8 × 10 3 -12.4 × 10 3 g mol -1 ). These original architectures of copolymers, when nanoprecipitated in water, the backbone-selective solvent, allowed us to obtain various structures of nanoparticles with a hydrodynamic diameter in the range of 65-99 nm. More interestingly, a plurality of morphologies going from unilamellar, multilamellar, and large compound vesicles to core-shell nanoparticles and depending on the PLA molecular weights were evidenced by combining cryo-transmission electron microscopy (cryo-TEM) and small-angle neutron scattering (SANS) studies. A first evaluation of their stealthiness by studying the stability and the interaction of these nano-objects with a model protein revealed the role played by the P(MeOx-co-PentOx) in these interactions, demonstrating the utility of this amphiphilic graft copolymers platform with well-defined architectures for the design of nanocarriers in drug delivery applications.

  7. Utilization of starch graft copolymers as selective depressants for lizardite in the flotation of pentlandite

    Science.gov (United States)

    Cao, Jian; Luo, Yong-Chun; Xu, Guo-Qiang; Qi, Li; Hu, Xiu-Qin; Xu, Peng-Fei; Zhang, Liu-Yi; Cheng, Shao-Yi

    2015-05-01

    This paper investigates the detrimental effect of lizardite surface characteristics on pentlandite flotation. To reduce the effect, two different starch graft copolymers, starch-graft-polyacrylamide (S-g-PAM) and starch-graft-polyacrylic acid (S-g-PAA) were synthesized as depressants for lizardite. The flotation results show that at pH value of 8, where the flotation of lizardite and pentlandite are routinely performed, S-g-PAM and S-g-PAA improve pentlandite recovery efficiently, compared with the traditional depressant carboxymethyl cellulose (CMC). Experimental results demonstrate that S-g-PAM and S-g-PAA disperse the hydrophilic lizardite particles from the pentlandite surface and also flocculate lizardite particles.

  8. 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...... 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...... part of the implant. Specimens are preserving now at - 20°C and wait for the push-out test which is destructive and will be performed on an 858 Bionex MTS hydraulic material testing machine (MTS system cooperation, Minneapolis, Minnesota, USA). The specimens for histological analysis were taken from...

  9. Mesoporous silica/polyacrylamide composite: Preparation by UV-graft photopolymerization, characterization and use as Hg(II) adsorbent

    Energy Technology Data Exchange (ETDEWEB)

    Saad, Ali, E-mail: ali.saad8803@gmail.com [Laboratory of Materials, Molecules and Applications, IPEST, University of Carthage, Sidi Bou Said road, B.P. 51, 2070 La Marsa (Tunisia); Faculté des Sciences de Tunis, Université El Manar, PO Box 248, El Manar II, 2092 Tunis (Tunisia); Univ Paris Diderot, Sorbonne Paris Cité, ITODYS, UMR 7086, CNRS, F-75013 Paris (France); Bakas, Idriss [Univ Paris Diderot, Sorbonne Paris Cité, ITODYS, UMR 7086, CNRS, F-75013 Paris (France); Laboratoire AQUAMAR, Equipe Matériaux Photocatalyse et Environnement, Faculté des Sciences, Université Ibn Zohr, B.P. 8106, Cité Dakhla, Agadir (Morocco); Piquemal, Jean-Yves; Nowak, Sophie [Univ Paris Diderot, Sorbonne Paris Cité, ITODYS, UMR 7086, CNRS, F-75013 Paris (France); Abderrabba, Manef, E-mail: abderrabbamanef@gmail.com [Laboratory of Materials, Molecules and Applications, IPEST, University of Carthage, Sidi Bou Said road, B.P. 51, 2070 La Marsa (Tunisia); Chehimi, Mohamed M., E-mail: chehimi@icmpe.cnrs.fr [Univ Paris Diderot, Sorbonne Paris Cité, ITODYS, UMR 7086, CNRS, F-75013 Paris (France); Université Paris Est, ICMPE (UMR7182), CNRS, UPEC, F-94320 Thiais (France)

    2016-03-30

    Graphical abstract: - Highlights: • Mesoporous silica/polyacrylamide nanocomposite adsorbent was prepared by UV-graft polymerization. • Polyacrylamide was successfully grafted onto the silanized mesoporous silica. • The Hg(II) adsorption capacity of the nanocomposite was as high as 177 mg g{sup −1} after 1 h at RT. • Adsorption process was found to fit pseudo second order kinetics and exothermic. - Abstract: MCM-41 ordered mesoporous silica was prepared, aminosilanized and grafted with polyacrylamide (PAAM) through in situ radical photopolymerization process. The resulting composite, denoted PAAM-NH{sub 2}-MCM-41, the calcined and silanized reference MCM-41s were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and N{sub 2} physisorption at 77 K. These complementary techniques brought strong supporting evidence for the silanization process followed by PAAM grafting. The surface composition was found to be PAAM-rich as judged by XPS. The composite was then employed for the uptake of Hg(II) from aqueous solutions. Adsorption was monitored versus pH, time, and temperature. The maximum adsorption capacity at 25 °C and pH 5.2 was 177 mg g{sup −1}. Kinetically, the equilibrium was reached within 60 min for a 100 mg L{sup −1} mercury solution. The adsorption of Hg(II) on PAAM-NH{sub 2}-MCM-41 composites followed second order kinetics. Thermodynamic parameters suggested that the favorable adsorption process is exothermic in nature and the adsorption is ascribed to a decrease in the degree of freedom of adsorbed ions which results in the entropy change. This work conclusively shows that mesoporous silica–polymer hybrid metal ion adsorbents (with robust silica–polymer interface) can be prepared in a simple way by in situ radical photopolymerization in the presence of

  10. 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

  11. Preparation and Characterization of Extruded Composites Based on Polypropylene and Chitosan Compatibilized with Polypropylene-Graft-Maleic Anhydride

    Science.gov (United States)

    Carrasco-Guigón, Fernando Javier; Rodríguez-Félix, Dora Evelia; Castillo-Ortega, María Mónica; Santacruz-Ortega, Hisila C.; Burruel-Ibarra, Silvia E.; Encinas-Encinas, Jose Carmelo; Plascencia-Jatomea, Maribel; Herrera-Franco, Pedro Jesus; Madera-Santana, Tomas Jesus

    2017-01-01

    The preparation of composites of synthetic and natural polymers represent an interesting option to combine properties; in this manner, polypropylene and chitosan extruded films using a different proportion of components and polypropylene-graft-maleic anhydride (PPgMA) as compatibilizer were prepared. The effect of the content of the biopolymer in the polypropylene (PP) matrix, the addition of compatibilizer, and the particle size on the properties of the composites was analyzed using characterization by fourier transform-infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), tensile strength, and contact angle, finding that in general, the addition of the compatibilizer and reducing the particle size of the chitosan, favored the physicochemical and morphological properties of the films. PMID:28772464

  12. Development of corn starch based green composites reinforced with Saccharum spontaneum L fiber and graft copolymers--evaluation of thermal, physico-chemical and mechanical properties.

    Science.gov (United States)

    Kaith, B S; Jindal, R; Jana, A K; Maiti, M

    2010-09-01

    In this paper, corn starch based green composites reinforced with graft copolymers of Saccharum spontaneum L. (Ss) fiber and methyl methacrylates (MMA) and its mixture with acrylamide (AAm), acrylonitrile (AN), acrylic acid (AA) were prepared. Resorcinol-formaldehyde (Rf) was used as the cross-linking agent in corn starch matrix and different physico-chemical, thermal and mechanical properties were evaluated. The matrix and composites were found to be thermally more stable than the natural corn starch backbone. Further the matrix and composites were subjected for biodegradation studies through soil composting method. Different stages of biodegradation were evaluated through FT-IR and scanning electron microscopic (SEM) techniques. S. spontaneum L fiber-reinforced composites were found to exhibit better tensile strength. On the other hand Ss-g-poly (MMA) reinforced composites showed maximum compressive strength and wear resistance than other graft copolymers reinforced composite and the basic matrix. (c) 2010 Elsevier Ltd. All rights reserved.

  13. Mesoporous material grafted with luminescent molecules for the design of selective metal ion chemosensor

    International Nuclear Information System (INIS)

    Zhang Huidong; Zhang Ping; Ye Kaiqi; Sun Yinghui; Jiang Shimei; Wang Yue; Pang Wenqin

    2006-01-01

    Luminescent Schiff-base groups have been successfully grafted on the surface of mesoporous material MCM-48. The grafted Schiff-base groups were employed to prepare luminescent Schiff-base-Zn complex that was covalently bound to the MCM-48 surface. These luminescent mesoporous materials were characterized with X-ray, UV-VIS and emission spectroscopic methods. Experimental results demonstrated that MCM-48 modified with functional groups exhibited novel luminescent property. The chemosensing property of modified MCM-48 sample was investigated. It was demonstrated that the fluorescence of MCM-48 solid with Schiff-base groups could be completely quenched by Cu 2+ cation and this mesoporous material was suitable for sensing Cu 2+ cation in aqueous media

  14. Systematic review and meta-analysis of surgical outcomes in Marfan patients undergoing aortic root surgery by composite-valve graft or valve sparing root replacement.

    Science.gov (United States)

    Flynn, Campbell D; Tian, David H; Wilson-Smith, Ashley; David, Tirone; Matalanis, George; Misfeld, Martin; Mastrobuoni, Stefano; El Khoury, Gebrine; Yan, Tristan D

    2017-11-01

    A major, life-limiting feature of Marfan syndrome (MFS) is the presence of aneurysmal disease. Cardiovascular intervention has dramatically improved the life expectancy of Marfan patients. Traditionally, the management of aortic root disease has been undertaken with composite-valve graft replacing the aortic valve and proximal aorta; more recently, valve sparing procedures have been developed to avoid the need for anticoagulation. This meta-analysis assesses the important surgical outcomes of the two surgical techniques. A systematic review and meta-analysis of 23 studies reporting the outcomes of aortic root surgery in Marfan patients with data extracted for outcomes of early and late mortality, thromboembolic events, late bleeding complications and surgical reintervention rates. The outcomes of 2,976 Marfan patients undergoing aortic root surgery were analysed, 1,624 patients were treated with composite valve graft (CVG) and 1,352 patients were treated with valve sparing root replacement (VSRR). When compared against CVG, VSRR was associated with reduced risk of thromboembolism (OR =0.32; 95% CI, 0.16-0.62, P=0.0008), late hemorrhagic complications (OR =0.18; 95% CI, 0.07-0.45; P=0.0003) and endocarditis (OR =0.27; 95% CI, 0.10-0.68; P=0.006). Importantly there was no significant difference in reintervention rates between VSRR and CVG (OR =0.89; 95% CI, 0.35-2.24; P=0.80). There is an increasing body of evidence that VSRR can be reliably performed in Marfan patients, resulting in a durable repair with no increased risk of re-operation compared to CVG, thus avoiding the need for systemic anticoagulation in selected patients.

  15. Studies on PLA grafting onto graphene oxide and its effect on the ensuing composite films

    Energy Technology Data Exchange (ETDEWEB)

    Campos, João M., E-mail: jmdcampos@ua.pt [CICECO - Aveiro Institute of Materials and Department of Chemistry, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro (Portugal); Instituto de Biotecnologia e Bioengenharia (IBB) and Department of Chemical Engineering, Instituto Superior Técnico, University of Lisbon, Av. Rovisco Pais, 1049-001 Lisbon (Portugal); Ferraria, Ana M.; Botelho do Rego, Ana M. [Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, University of Lisbon, Av. Rovisco Pais, 1049-001 Lisbon (Portugal); Ribeiro, M. Rosário [Centro de Química Estrutural (CQE) and Department of Chemical Engineering, Instituto Superior Técnico, University of Lisbon, Av. Rovisco Pais, 1049-001 Lisbon (Portugal); Barros-Timmons, Ana [CICECO - Aveiro Institute of Materials and Department of Chemistry, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro (Portugal)

    2015-09-15

    Polylactide (PLA) with a terminal triple bond was synthesized by organocatalyzed ring-opening polymerization and coupled with azide-functionalized graphene oxide (GO) through an azide-alkyne cycloaddition “click” reaction. The functionalized graphenic species involved were analyzed by spectroscopic techniques (FT-IR, solid state {sup 13}C NMR, Raman), which confirmed the coupling of PLA and GO. Additionally, an in depth study of the prepared GO, intermediates and GO-g-PLA hybrid was carried out that sheds light on the mechanisms involved in the functionalization path. The obtained GO-g-PLA hybrid, containing at least 20% of biopolymer, presented an exfoliated graphenic structure, as established by XRD. The conditions used in the grafting of the PLA chains inhibited the crystallization and melting observed for the free polymer. Furthermore, the graphene oxide seems to be reduced during functionalization, which can also be an advantage. Nanocomposites were obtained as solvent-cast films, prepared by dispersion of the GO-g-PLA hybrid in commercial PLA. Preliminary results regarding the performance of these nanocomposites, obtained by DSC and DMA, highlighted the effect of functionalization. Loading values as low as 0.5% suffice to improve the mechanical properties over a broad temperature range due to the high surface area resulting from the good dispersibility of polymer functionalized nanofillers and/or their effect on the polymer chain organization. - Highlights: • A graphene oxide/PLA (GO-g-PLA) hybrid was obtained by a grafting-to method. • Grafting of PLA chains onto the surface of GO inhibited polymer crystallization. • The GO-g-PLA material was used in the reinforcement of PLA, as nanocomposite films. • GO-g-PLA provides more homogeneously reinforced nanocomposite films, than neat GO. • Nanocomposite films with 0.5% loading present high storage modulus even above T{sub g}.

  16. Natural fibre selection for composite eco-design

    DEFF Research Database (Denmark)

    Corona, Andrea; Madsen, Bo; Hauschild, Michael Zwicky

    2016-01-01

    Natural fibre composites (NFC) are gaining interest in manufacturing because they address some of the environmental problems of traditional composites: use of non-renewable resources, and large impacts related to their production and disposal. Since natural fibres are not yet optimized...... for composite production, it is crucial to identify the most appropriate applications, and determine the optimal fibre/matrix ratio. A methodology is proposed for early-stage decisions support on selection of bio-composite materials. Results help identify the application with the largest reduction...

  17. Graft-versus-host disease is enhanced by selective CD73 blockade in mice.

    Directory of Open Access Journals (Sweden)

    Long Wang

    Full Text Available CD73 functions as an ecto-5'-nucleotidase to produce extracellular adenosine that has anti-inflammatory and immunosuppressive activity. We here demonstrate that CD73 helps control graft-versus-host disease (GVHD in mouse models. Survival of wild-type (WT recipients of either allogeneic donor naïve CD73 knock-out (KO or WT T cells was similar suggesting that donor naïve T cell CD73 did not contribute to GVHD. By contrast, donor CD73 KO CD4(+CD25(+ regulatory T cells (Treg had significantly impaired ability to mitigate GVHD mortality compared to WT Treg, suggesting that CD73 on Treg is critical for GVHD protection. However, compared to donor CD73, recipient CD73 is more effective in limiting GVHD. Pharmacological blockade of A2A receptor exacerbated GVHD in WT recipients, but not in CD73 KO recipients, suggesting that A2 receptor signaling is primarily implicated in CD73-mediated GVHD protection. Moreover, pharmacological blockade of CD73 enzymatic activity induced stronger alloreactive T cell activity, worsened GVHD and enhanced the graft-versus-leukemia (GVL effect. These findings suggest that both donor and recipient CD73 protects against GVHD but also limits GVL effects. Thus, either enhancing or blocking CD73 activity has great potential clinical application in allogeneic bone marrow transplants.

  18. Percutaneous, Transtrapezial Fixation without Bone Graft Leads to Consolidation in Selected Cases of Delayed Union of the Scaphoid Waist.

    Science.gov (United States)

    Vanhees, Matthias; van Riet, Roger R P; van Haver, Annemieke; Kebrle, Radek; Meermans, Geert; Verstreken, Frederik

    2017-08-01

    Purpose  We evaluated clinical and radiographic outcome of percutaneous transtrapezial fixation of the scaphoid delayed union or nonunion using a headless bone screw without bone grafting. Methods  Sixteen patients with delayed union or nonunion of the scaphoid were included in this retrospective study between 2006 and 2011. All patients had a delayed presentation of scaphoid fracture, and none of them was treated conservatively elsewhere. Patients with bone graft, sclerotic bone debridement, or displacement of the fragment at the nonunion site were excluded. A percutaneous transtrapezial fixation technique was used in all cases. Patients were reviewed until clinical and radiographic union was observed. At the final follow-up, DASH (Disabilities of the Arm, Shoulder and Hand) and PRWHE (Patient-Rated Wrist and Hand Evaluation) outcome scores were completed. Results  Radiographic union was obtained in 15 out of 16 patients (94%) at an average follow-up of 36 months (range: 12-98 months). No complications from the percutaneous technique were noted. The average DASH score was 6 (range: 0-39) and the average PRWHE score was 10 (range: 0-56). No statistical significant difference in range of motion and grip strength was found between the operated side and the contralateral side. Conclusion  Percutaneous transtrapezial screw fixation for delayed or nonunion of selected scaphoid fractures without bone grafting is promising. At a mean of 4 months, 94% union was obtained with good functional results when there was no sclerosis, minimal osteolysis, and no displacement at the scaphoid nonunion site. Type of Study  Therapeutic study. Level of Evidence  IV.

  19. Particle compositions with a pre-selected cell internalization mode

    Science.gov (United States)

    Decuzzi, Paolo (Inventor); Ferrari, Mauro (Inventor)

    2012-01-01

    A method of formulating a particle composition having a pre-selected cell internalization mode involves selecting a target cell having surface receptors and obtaining particles that have i) surface moieties, that have an affinity for or are capable of binding to the surface receptors of the cell and ii) a preselected shape, where a surface distribution of the surface moieties on the particles and the shape of the particles are effective for the pre-selected cell internalization mode.

  20. Effects of Composition of Alginate-Polyethylene Glycol Microcapsules and Transplant Site on Encapsulated Islet Graft Outcomes in Mice.

    Science.gov (United States)

    Villa, Chiara; Manzoli, Vita; Abreu, Maria M; Verheyen, Connor A; Seskin, Michael; Najjar, Mejdi; Molano, R Damaris; Torrente, Yvan; Ricordi, Camillo; Tomei, Alice A

    2017-05-01

    Understanding the effects of capsule composition and transplantation site on graft outcomes of encapsulated islets will aid in the development of more effective strategies for islet transplantation without immunosuppression. Here, we evaluated the effects of transplanting alginate (ALG)-based microcapsules (Micro) in the confined and well-vascularized epididymal fat pad (EFP) site, a model of the human omentum, as opposed to free-floating in the intraperitoneal cavity (IP) in mice. We also examined the effects of reinforcing ALG with polyethylene glycol (PEG). To allow transplantation in the EFP site, we minimized capsule size to 500 ± 17 μm. Unlike ALG, PEG resists osmotic stress, hence we generated hybrid microcapsules by mixing PEG and ALG (MicroMix) or by coating ALG capsules with a 15 ± 2 μm PEG layer (Double). We found improved engraftment of fully allogeneic BALB/c islets in Micro capsules transplanted in the EFP (median reversal time [MRT], 1 day) versus the IP site (MRT, 5 days; P < 0.01) in diabetic C57BL/6 mice and of Micro encapsulated (MRT, 8 days) versus naked (MRT, 36 days; P < 0.01) baboon islets transplanted in the EFP site. Although in vitro viability and functionality of islets within MicroMix and Double capsules were comparable to Micro, addition of PEG to ALG in MicroMix capsules improved engraftment of allogeneic islets in the IP site, but resulted deleterious in the EFP site, probably due to lower biocompatibility. Our results suggest that capsule composition and transplant site affect graft outcomes through their effects on nutrient availability, capsule stability, and biocompatibility.

  1. Mineral Composition of Selected Serbian Propolis Samples

    Directory of Open Access Journals (Sweden)

    Tosic Snezana

    2017-06-01

    Full Text Available The aim of this work was to determine the content of 22 macro- and microelements in ten raw Serbian propolis samples which differ in geographical and botanical origin as well as in polluted agent contents by atomic emission spectrometry with inductively coupled plasma (ICP-OES. The macroelements were more common and present Ca content was the highest while Na content the lowest. Among the studied essential trace elements Fe was the most common element. The levels of toxic elements (Pb, Cd, As and Hg were also analyzed, since they were possible environmental contaminants that could be transferred into propolis products for human consumption. As and Hg were not detected in any of the analyzed samples but a high level of Pb (2.0-9.7 mg/kg was detected and only selected portions of raw propolis could be used to produce natural medicines and dietary supplements for humans. Obtained results were statistically analyzed, and the examined samples showed a wide range of element content.

  2. Preparation of Al Fe{sub 2}O{sub 3} Core-Shell Composites Using Amphiphilic Graft Copolymer Template

    Energy Technology Data Exchange (ETDEWEB)

    Patel, Rajkumar; Kim, Sang Jin; Kim, Jin Kyu; Kim, Jong Hak [Yonsei University, Seoul (Korea, Republic of); Park, Jung Su [Agency for Defense and Development (ADD), Daejeon (Korea, Republic of)

    2014-04-15

    A graft copolymer of poly(vinyl chloride)-g-poly(oxyethylene methacrylate) (PVC-g-POEM) was synthesized via atom transfer radical polymerization (ATRP) and used as a structure-directing agent to prepare Al Fe{sub 2}O{sub 3} core-shell nanocomposites through a sol-gel process. The amphiphilic property of PVC-g-POEM allows for good dispersion of Al particles and leads to specific interaction with iron ethoxide, a precursor of Fe{sub 2}O{sub 3}. Secondary bonding interaction in the sol-gel composites was characterized by Fourier transform-infrared (FT-IR) spectroscopy. The well-organized morphology of Al Fe{sub 2}O{sub 3} core-shell nanocomposites was observed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Energy dispersive X-ray (EDX) and X-ray diffraction (XRD) were used to analyze the elemental composition and crystallization structure of the composites.

  3. Effect of different rootstocks on growth, chlorophyll a fluorescence and mineral composition of two grafted scions of tomato

    NARCIS (Netherlands)

    Goto, R.; Miguel, de A.; Marsal, J.I.; Gorbe, E.; Calatayud, A.

    2013-01-01

    Two tomato scions (cvs. ‘Raf’ and ‘Gorety’) were grafted on three different rootstocks: S. torvum, ‘Beaufort’ (Lycopersicum esculentum × Lycopersicum hirsutum) and intermediate grafting of eggplant ‘Cristal’ between tomato and S. torvum (double graft). Plants were grown in Mediterranean greenhouse

  4. Crystallization of calcium carbonate on radiation-grafted polyethylene films

    International Nuclear Information System (INIS)

    Hou Zhengchi; Zhang Fengying; Deng Bo; Yang Haijun; Chen Shuang; Sheng Kanglong

    2006-01-01

    In biomineralization processes, nucleation and growth of inorganic crystals can be regulated by organic template molecules. This has inspired great interest in studying mimic biomineralization. In our study, growing CaCO 3 crystals on PE films functionalized through radiation-induced grafting was attempted. PE films grafted with different functional groups of different distributions and densities were used as substrates for CaCO 3 nucleation and crystal growth from Ca(HCO 3 ) 2 supersaturated solution under different environmental conditions (e.g. additives and temperature) to study the effects and mechanisms. The grafted PE films were analyzed by ATR-FTIR and AFM, and the evolution of CaCO 3 crystal formation on the grafted PE film was characterized by SEM, FTIR, and XRD. The results indicated that heterogeneous nucleation of CaCO 3 crystals was significantly facilitated by the functional groups grafted on the surface of PE films, that the morphology of CaCO 3 crystals could be controlled by distribution and density of the grafted functional groups, and that polymorphism of CaCO 3 crystal could be regulated by selection of grafting functional groups. We believe that studying the effects of chemical structures on inorganic crystallization is of great importance since radiation-induced grafting is an effective method to graft desirable functional groups onto different polymers by selected monomers, in the endeavor of developing advanced organic/inorganic composites with high performance, with a wide availability of polymers, monomers and inorganic solutions. (authors)

  5. CD34+selected stem cell boosts can improve poor graft function after paediatric allogeneic stem cell transplantation.

    Science.gov (United States)

    Mainardi, Chiara; Ebinger, Martin; Enkel, Sigrid; Feuchtinger, Tobias; Teltschik, Heiko-Manuel; Eyrich, Matthias; Schumm, Michael; Rabsteyn, Armin; Schlegel, Patrick; Seitz, Christian; Schwarze, Carl-Phillip; Müller, Ingo; Greil, Johann; Bader, Peter; Schlegel, Paul-Gerhardt; Martin, David; Holzer, Ursula; Döring, Michaela; Handgretinger, Rupert; Lang, Peter

    2018-01-01

    Poor graft function (PGF) is a severe complication of haematopoietic stem cell transplantation (HSCT) and administration of donor stem cell boosts (SCBs) represents a therapeutic option. We report 50 paediatric patients with PGF who received 61 boosts with CD34 + selected peripheral blood stem cells (PBSC) after transplantation from matched unrelated (n = 25) or mismatched related (n = 25) donors. Within 8 weeks, a significant increase in median neutrophil counts (0·6 vs. 1·516 × 10 9 /l, P < 0·05) and a decrease in red blood cell and platelet transfusion requirement (median frequencies 1 and 7 vs. 0, P < 0·0001 and <0·001), were observed, and 78·8% of patients resolved one or two of their cytopenias. 36·5% had a complete haematological response. Median lymphocyte counts for CD3 + , CD3 + CD4 + , CD19 + and CD56 + increased 8·3-, 14·2-, 22.- and 1·6-fold. The rate of de novo acute graft-versus-host disease (GvHD) grade I-III was only 6% and resolved completely. No GvHD grade IV or chronic GvHD occurred. Patients who responded to SCB displayed a trend toward better overall survival (OS) (P = 0·07). Thus, administration of CD34 + selected SCBs from alternative donors is safe and effective. Further studies are warranted to clarify the impact on immune reconstitution and survival. © 2017 John Wiley & Sons Ltd.

  6. Surface modification of nanofibrous polycaprolactone/gelatin composite scaffold by collagen type I grafting for skin tissue engineering

    International Nuclear Information System (INIS)

    Gautam, Sneh; Chou, Chia-Fu; Dinda, Amit K.; Potdar, Pravin D.; Mishra, Narayan C.

    2014-01-01

    In the present study, a tri-polymer polycaprolactone (PCL)/gelatin/collagen type I composite nanofibrous scaffold has been fabricated by electrospinning for skin tissue engineering and wound healing applications. Firstly, PCL/gelatin nanofibrous scaffold was fabricated by electrospinning using a low cost solvent mixture [chloroform/methanol for PCL and acetic acid (80% v/v) for gelatin], and then the nanofibrous PCL/gelatin scaffold was modified by collagen type I (0.2–1.5 wt.%) grafting. Morphology of the collagen type I-modified PCL/gelatin composite scaffold that was analyzed by field emission scanning electron microscopy (FE-SEM), showed that the fiber diameter was increased and pore size was decreased by increasing the concentration of collagen type I. Fourier transform infrared (FT-IR) spectroscopy and thermogravimetric (TG) analysis indicated the surface modification of PCL/gelatin scaffold by collagen type I immobilization on the surface of the scaffold. MTT assay demonstrated the viability and high proliferation rate of L929 mouse fibroblast cells on the collagen type I-modified composite scaffold. FE-SEM analysis of cell-scaffold construct illustrated the cell adhesion of L929 mouse fibroblasts on the surface of scaffold. Characteristic cell morphology of L929 was also observed on the nanofiber mesh of the collagen type I-modified scaffold. Above results suggest that the collagen type I-modified PCL/gelatin scaffold was successful in maintaining characteristic shape of fibroblasts, besides good cell proliferation. Therefore, the fibroblast seeded PCL/gelatin/collagen type I composite nanofibrous scaffold might be a potential candidate for wound healing and skin tissue engineering applications. - Highlights: • PCL/gelatin/collagen type I scaffold was fabricated for skin tissue engineering. • PCL/gelatin/collagen type I scaffold showed higher fibroblast growth than PCL/gelatin one. • PCL/gelatin/collagen type I might be one of the ideal scaffold for

  7. Surface modification of nanofibrous polycaprolactone/gelatin composite scaffold by collagen type I grafting for skin tissue engineering.

    Science.gov (United States)

    Gautam, Sneh; Chou, Chia-Fu; Dinda, Amit K; Potdar, Pravin D; Mishra, Narayan C

    2014-01-01

    In the present study, a tri-polymer polycaprolactone (PCL)/gelatin/collagen type I composite nanofibrous scaffold has been fabricated by electrospinning for skin tissue engineering and wound healing applications. Firstly, PCL/gelatin nanofibrous scaffold was fabricated by electrospinning using a low cost solvent mixture [chloroform/methanol for PCL and acetic acid (80% v/v) for gelatin], and then the nanofibrous PCL/gelatin scaffold was modified by collagen type I (0.2-1.5wt.%) grafting. Morphology of the collagen type I-modified PCL/gelatin composite scaffold that was analyzed by field emission scanning electron microscopy (FE-SEM), showed that the fiber diameter was increased and pore size was decreased by increasing the concentration of collagen type I. Fourier transform infrared (FT-IR) spectroscopy and thermogravimetric (TG) analysis indicated the surface modification of PCL/gelatin scaffold by collagen type I immobilization on the surface of the scaffold. MTT assay demonstrated the viability and high proliferation rate of L929 mouse fibroblast cells on the collagen type I-modified composite scaffold. FE-SEM analysis of cell-scaffold construct illustrated the cell adhesion of L929 mouse fibroblasts on the surface of scaffold. Characteristic cell morphology of L929 was also observed on the nanofiber mesh of the collagen type I-modified scaffold. Above results suggest that the collagen type I-modified PCL/gelatin scaffold was successful in maintaining characteristic shape of fibroblasts, besides good cell proliferation. Therefore, the fibroblast seeded PCL/gelatin/collagen type I composite nanofibrous scaffold might be a potential candidate for wound healing and skin tissue engineering applications. © 2013.

  8. Sweet orange trees grafted on selected rootstocks fertilized with nitrogen, phosphorus and potassium

    Directory of Open Access Journals (Sweden)

    Quaggio José Antônio

    2004-01-01

    Full Text Available The majority of citrus trees in Brazil are grafted on 'Rangpur lime' (Citrus limonia Osb. rootstock. Despite its good horticultural performance, search for disease tolerant rootstock varieties to improve yield and longevity of citrus groves has increased. The objective of this work was to evaluate yield efficiency of sweet oranges on different rootstocks fertilized with N, P, and potassium. Tree growth was affected by rootstock varieties; trees on 'Swingle' citrumelo [Poncirus trifoliata (L. Raf. × C. paradisi Macf.] presented the smallest canopy (13.3 m³ in the fifth year after tree planting compared to those on 'Rangpur lime' and 'Cleopatra' mandarin [C. reshni (Hayata hort. ex Tanaka] grown on the same grove. Although it was observed an overall positive relationship between canopy volume and fruit yield (R² = 0.95**, yield efficiency (kg m-3 was affected by rootstocks, which demonstrated 'Rangpur lime' superiority in relation to Cleopatra. Growth of citrus trees younger than 5-yr-old might be improved by K fertilization rates greater than currently recommended in Brazil, in soils with low K and subjected to nutrient leaching losses.

  9. Reduction of Relapse after Unrelated Donor Stem Cell Transplantation by KIR-Based Graft Selection

    Science.gov (United States)

    Heidenreich, Silke; Kröger, Nicolaus

    2017-01-01

    Besides donor T cells, natural killer (NK) cells are considered to have a major role in preventing relapse after allogeneic hematopoietic stem cell transplantation (HSCT). After T-cell-depleted haploidentical HSCT, a strong NK alloreactivity has been described. These effects have been attributed to killer-cell immunoglobulin-like receptors (KIR). Abundant reports suggest a major role of KIR not only on outcome after haploidentical HSCT but also in the unrelated donor setting. In this review, we give a brief overview of the mechanism of NK cell activation, nomenclature of KIR haplotypes, human leukocyte antigen (HLA) groups, and distinct models for prediction of NK cell alloreactivity. It can be concluded that KIR-ligand mismatch seems to provoke adverse effects in unrelated donor HSCT with reduced overall survival and increased risk for high-grade acute graft-versus-host disease. The presence of activating KIR, as seen in KIR haplotype B, as well as the patient’s HLA C1/x haplotype might reduce relapse in myeloid malignancies. PMID:28228753

  10. Surface Grafted Glycopolymer Brushes to Enhance Selective Adhesion of HepG2 Cells

    DEFF Research Database (Denmark)

    Chernyy, Sergey; Jensen, Bettina Elisabeth Brøgger; Shimizu, Kyoko

    2013-01-01

    This work demonstrates the application of carbohydrate based methacrylate polymer brush, poly(2-lactobionamidoethyl methacrylate), for the purpose of cell adhesion studies. The first part of the work illustrates the effects of the structure of the aminosilane based ATRP initiator layer on the pol......This work demonstrates the application of carbohydrate based methacrylate polymer brush, poly(2-lactobionamidoethyl methacrylate), for the purpose of cell adhesion studies. The first part of the work illustrates the effects of the structure of the aminosilane based ATRP initiator layer...... on the polymerization kinetics of 2-lactobionamidoethyl methacrylate) (LAMA) monomer on thermally oxidized silicon wafer. Both monolayer and multilayered aminosilane precursor layers have been prepared followed by reaction with 2-bromoisobutyrylbromide to form the ATRP initiator layer. It is inferred from the kinetic...... studies that the rate of termination is low on a multilayered initiator layer compared to a disordered monolayer structure. However both initiator types results in similar graft densities. Furthermore, it is shown that thick comb-like poly(LAMA) brushes can be constructed by initiating a second ATRP...

  11. Composite Payload Fairing Structural Architecture Assessment and Selection

    Science.gov (United States)

    Krivanek, Thomas M.; Yount, Bryan C.

    2012-01-01

    This paper provides a summary of the structural architecture assessments conducted and a recommendation for an affordable high performance composite structural concept to use on the next generation heavy-lift launch vehicle, the Space Launch System (SLS). The Structural Concepts Element of the Advanced Composites Technology (ACT) project and its follow on the Lightweight Spacecraft Structures and Materials (LSSM) project was tasked with evaluating a number of composite construction technologies for specific Ares V components: the Payload Shroud, the Interstage, and the Core Stage Intertank. Team studies strived to address the structural challenges, risks and needs for each of these vehicle components. Leveraging off of this work, the subsequent Composites for Exploration (CoEx) effort is focused on providing a composite structural concept to support the Payload Fairing for SLS. This paper documents the evaluation and down selection of composite construction technologies and evolution to the SLS Payload Fairing. Development of the evaluation criteria (also referred to as Figures of Merit or FOMs), their relative importance, and association to vehicle requirements are presented. A summary of the evaluation results, and a recommendation of the composite concept to baseline in the Composites for Exploration (CoEx) project is presented. The recommendation for the SLS Fairing is a Honeycomb Sandwich architecture based primarily on affordability and performance with two promising alternatives, Hat stiffened and Fiber Reinforced Foam (FRF) identified for eventual program block upgrade.

  12. Chemical composition and in vitro ruminal fermentation of selected ...

    African Journals Online (AJOL)

    Chemical composition and in vitro ruminal fermentation of selected grasses in the semiarid savannas of Swaziland. ... In the Simunye grazing area the most common species were B. insculpta, U. mosambicensis, Heteropogon contortus, Panicum deustum and P. maximum. For grasses harvested from Simunye, the most (p ...

  13. A new strategy of fingertip reattachment: sequential use of microsurgical technique and pocketing of composite graft.

    Science.gov (United States)

    Kim, K S; Eo, S R; Kim, D Y; Lee, S Y; Cho, B H

    2001-01-01

    Many methods have been used to reattach amputated fingertips. Of these methods, microsurgery has been accepted as the procedure of choice because the defining characteristic of a microsurgically replanted finger is that its surival in the recipient bed is predicated on functioning intravascular circulation. Although considerable progress has been made in the techniques for microvascular replantation of amputated fingers, the replantation of an amputated fingertip is difficult because digital arteries branch into small arteries. This is in addition to digital veins that run from both sides of the nail bed to the median dorsal sides, which are difficult to separate from the immobile soft tissue. Furthermore, even with the most technically skilled microsurgeon, replantation failure often occurs, especially in severe injury cases. Therefore, the technique is not the only protection against failure, and a new strategy of fingertip reattachment is needed. From March of 1997 to December of 1999, 12 fingers of 11 patients with zone 1 or zone 2 fingertip amputations that were reattached microsurgically but were compromised were deepithelialized, reattached, and then inserted into the abdominal pocket. All had been complete amputations with crushing injuries. Approximately 3 weeks later, the fingers were depocketed and covered with a skin graft. Of the 12 fingers, 7 survived completely and 3 had partial necrosis on less than one-third the volume of the amputated part. The complete survival rate was approximately 58 percent. The results of the above 10 fingers were satisfactory from both functional and cosmetic aspects. The authors believe that this high success rate was achieved because the deepithelialized finger pulp was placed in direct contact with the deep abdominal fascia, which was equipped with plentiful vascularity, not subcutaneous fat. In addition, the pocketing was performed promptly before necrosis of the compromised fingertip occurred. From the results of this

  14. The effect of Hydroxyapatite/collagen I composites, bone marrow aspirate and bone graft on fixation of bone implants in sheep

    DEFF Research Database (Denmark)

    Babiker, Hassan

      The effect of Hydroxyapatite/collagen I composites, bone marrow aspirate and bone graft on fixation of bone implants IN SHEEP   Ph.D. Student, Hassan Babiker; Associate Professor, Ph.D. Ming Ding; Professor, dr.med., Soren Overgaard. Department of Orthopaedic Surgery, Odense University Hospital......, Odense, Denmark   Background: Hydroxyapatite and collagen composites (HA/coll) have the potential in mimicking and replacing skeletal bones. This study attempted to determine the effect of newly developed HA/coll-composites with and without bone marrow aspirate (BMA) in order to enhance the fixation...

  15. Intercalary Reconstruction after Wide Resection of Malignant Bone Tumors of the Lower Extremity Using a Composite Graft with a Devitalized Autograft and a Vascularized Fibula

    Directory of Open Access Journals (Sweden)

    Koichi Ogura

    2015-01-01

    Full Text Available Introduction. Although several intercalary reconstructions after resection of a lower extremity malignant bone tumor are reported, there are no optimal methods which can provide a long-term reconstruction with fewest complications. We present the outcome of reconstruction using a devitalized autograft and a vascularized fibula graft composite. Materials and Methods. We conducted a retrospective review of 11 patients (7 males, 4 females; median age 27 years undergoing reconstruction using a devitalized autograft (pasteurization (n=6, deep freezing (n=5 and a vascularized fibula graft composite for lower extremity malignant bone tumors (femur (n=10, tibia (n=1. Results. The mean period required for callus formation and bone union was 4.4 months and 9.9 months, respectively. Four postoperative complications occurred in 3 patients: 2 infections (1 pasteurized autograft, 1 frozen autograft and 1 fracture and 1 implant failure (both in pasteurized autografts. Graft removal was required in 2 patients with infections. The mean MSTS score was 81% at last follow-up. Conclusions. Although some complications were noted in early cases involving a pasteurized autograft, our novel method involving a combination of a frozen autograft with a vascularized fibula graft and rigid fixation with a locking plate may offer better outcomes than previously reported allografts or devitalized autografts.

  16. Selective adsorption of Pb (II) ions by amylopectin-g-poly (acrylamide-co-acrylic acid): A bio-degradable graft copolymer.

    Science.gov (United States)

    Sasmal, Dinabandhu; Maity, Jayanta; Kolya, Haradhan; Tripathy, Tridib

    2017-04-01

    Amylopectin-g-poly (acrylamide-co-acrylic acid) [AP-g-poly (AM-co-AA)] was synthesised in water medium by using potassium perdisulphate as an initiator. The graft copolymer was characterized by molecular weight determination by size exclusion chromatography (SEC), fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR) spectroscopy, scanning electron microscope (SEM) studies, thermal analysis, measurement of neutralisation equivalent and biodegradation studies. The graft copolymer was used for Pb (II) ion removal from aqueous solution. The Pb (II) ion removal capacity of the graft copolymer was also compared with another laboratory developed graft copolymer Amylopectin-g-poly (acrylamide) (AP-g-PAM). Both the graft copolymers were also used for the competitive metal ions removal with Pb (II)/Cd (II), Pb (II)/Zn (II), Pb (II)/Ni (II), Pb (II)/Cu (II) pairs separately under similar conditions. AP-g-poly (AM-co-AA) showed better Pb (II) ion adsorbing power over AP-g-PAM and also much selective towards Pb (II) ions. The adsorption follows a second order rate equation and Langmuir isotherm model. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. New grafted ferrite particles/liquid crystal composite under magnetic field

    Science.gov (United States)

    Manaila Maximean, D.

    2018-04-01

    A new colloidal composite formed by specially synthesized dimethylphenyl ferrite particles and a nematic liquid crystal (LC) is presented. By applying a small magnetic field during polarizing optical microscopy observations, it was found that the magnetic moment of the synthesized ferrite is perpendicular to the director of the LC. The optical transmission of laser light across the ferronematic was investigated under magnetic field. The critical magnetic field corresponding to the Freedericksz transition was obtained and discussed according to the Burylov and Raikher theory.

  18. Establishment of a clonal bank of Caesalpinia spinosa (Mol.) O. Kuntz by selection of plus trees and grafting

    OpenAIRE

    Jenny E Nuñez; Elisa Quiala; Manuel de Feria; Saúl Mestanza; Rafael Gómez-Kosky; Franklin R Cuadrado; Michel Leiva-Mora

    2017-01-01

    In Ecuador, plant propagation techniques are not available commercially to establish clonal banks of Caesalpinia spinosa (Mol.) O. Kuntz (guarango) plus trees, which limits the development of in vitro propagation protocols of this specie. The objective of the present work was to establish a clonal bank of C. spinosa by selecting plus trees and grafting. Guarango trees belonging to the province of Chimborazo, Guano canton were selected based on total height, height at the beginning of the crow...

  19. Valve-Sparing Root Replacement Compared With Composite Valve Graft Procedures in Patients With Aortic Root Dilation.

    Science.gov (United States)

    Ouzounian, Maral; Rao, Vivek; Manlhiot, Cedric; Abraham, Nachum; David, Carolyn; Feindel, Christopher M; David, Tirone E

    2016-10-25

    Although aortic valve-sparing (AVS) operations are established alternatives to composite valve graft (CVG) procedures for patients with aortic root aneurysms, comparative long-term outcomes are lacking. This study sought to compare the results of patients undergoing AVS procedures with those undergoing CVG operations. From 1990 to 2010, a total of 616 patients age Marfan syndrome and lower rates of bicuspid aortic valve than those undergoing bio-CVG or m-CVG procedures. In-hospital mortality (0.3%) and stroke rate (1.3%) were similar among groups. After adjusting for clinical covariates, both bio-CVG and m-CVG procedures were associated with increased long-term major adverse valve-related events compared with patients undergoing AVS (hazard ratio [HR]: 3.4, p = 0.005; and HR: 5.2, p valve-related complications when compared with bio-CVG and m-CVG. AVS is the treatment of choice for young patients with aortic root aneurysm and normal or near-normal aortic cusps. Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  20. Network formation in graphene oxide composites with surface grafted PNIPAM chains in aqueous solution characterized by rheological experiments.

    Science.gov (United States)

    GhavamiNejad, Amin; Hashmi, Saud; Joh, Han-Ik; Lee, Sungho; Lee, Youn-Sik; Vatankhah-Varnoosfaderani, Mohammad; Stadler, Florian J

    2014-05-14

    Poly N-isopropyl acrylamide (PNI) radically polymerized in aqueous solution in the presence of graphene oxide (GO) can significantly change the properties of the resulting solution from a regular polymer solution to a soft solid with a GO content of only 0.176 wt% (3 wt% with respect to PNI). However, these properties require the presence of both grafting and supramolecular interactions between polymer chains and hydrophilic groups on GO (-OH, -COOH), proven by Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), X-ray diffraction and spectroscopy (XRD) and Raman spectra. While very low GO-contents (below 0.05 wt%) only lead to a labile structure, which can be disassembled by shear, higher contents yield composites with solid-like characteristics. This is clearly evident from the rheological behaviour, which changes significantly at a GO content around 0.15 wt%. Intensive shearing destroys the weak network, which cannot reform quickly at lower GO-concentrations, while at intermediate concentrations, restructuring is fast. GO-contents of 0.176 wt% lead to a material behaviour, which almost perfectly recovers from small deformations (creep and creep recovery compliance almost match) but larger deformations lead to permanent damage to the sample.

  1. Brucellosis With Multi-Organ Involvement in a Patient With History of Composite Aortic Graft and Hepatitis B.

    Science.gov (United States)

    Dehghan Manshadi, Seyed Ali; Rezahosseini, Omid; Abdi Liaei, Zahra

    2016-11-01

    The brucellosis with multi-organ involvement in a patient with a history of the composite aortic graft (Bentall procedure) and Hepatitis B infection is rare. A 35-year-old man presented to us with fever and loss of consciousness. Four years ago, he was IDU and underwent cardiac surgery because of endocarditis. Recently lumbar spondylodiscitis was diagnosed. The Wright (1/320) and Coombs Wright tests (1/640) were positive. After CNS imaging, lumbar puncture was done. The CSF pleocytosis was lymphocyte dominant. In cardiac echocardiography, large vegetation on prosthetic aortic valve leaflets was seen. The brain MRI was reported abnormal. Treatment of brucellosis started with Ceftriaxone, Doxycycline, Rifampin and Gentamycin. After 4 days, he became oriented, and fever was disappeared then we continued the treatment for 16 days. The patient discharged and followed by daily phone calls. As symptoms of abdominal pain and jaundice were presented on the fifth day, he re-admitted. The patient expired because of hepatorenal and cardiac insufficiency. Drug side effects, activation of Hepatitis B and embolism of cardiac vegetation to other organs were suspected causes of death. We do not suggest medical therapy without cardiac surgery in such cases. When combination therapy is necessary for brucellosis in an HBsAg-positive patient, hepatitis virus activity should be assess by HBV-DNA PCR and the dose of drugs with known hepatotoxic effects such as rifampin and co-trimoxazole should be adjust. Combination therapy with quinolones instead of hepatoxic drugs is one of our suggustions.

  2. Preparation of hyperbranched poly (amidoamine)-grafted graphene nanolayers as a composite and curing agent for epoxy resin

    Science.gov (United States)

    Gholipour-Mahmoudalilou, Meysam; Roghani-Mamaqani, Hossein; Azimi, Reza; Abdollahi, Amin

    2018-01-01

    Thermal properties of epoxy resin were improved by preparation of a curing agent of poly (amidoamine) (PAMAM) dendrimer-grafted graphene oxide (GO). Hyperbranched PAMAM-modified GO (GD) was prepared by a divergent dendrimer synthesis methodology. Modification of GO with (3-Aminopropyl)triethoxysilane (APTES), Michael addition of methacrylic acid, and amidation reaction with ethylenediamine results in the curing agent of GD. Then, epoxy resin was cured in the presence of different amounts of GD and the final products were compared with ethylenediamine-cured epoxy resin (E) in their thermal degradation temperature and char contents. Functionalization of GO with APTES and hyperbranched dendrimer formation at the surface of GO were evaluated by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and thermogravimetric analysis (TGA) results. TGA results showed that the weight loss associated with chemical moieties in GONH2, GOMA, and GD is estimated to be 10.1, 12.2, and 14.1%, respectively. Covalent attachment of dendrimer at the surface of GO increases its thermal stability. TGA also showed that decomposition temperature and char content are higher for composites compared with E. Scanning and transmission electron microscopies show that flat and smooth graphene nanolayers are wrinkled in GO and re-stacking and flattening of nanolayers is observed in GD.

  3. Characterization of selected LDEF polymer matrix resin composite materials

    Science.gov (United States)

    Young, Philip R.; Slemp, Wayne S.; Witte, William G., Jr.; Shen, James Y.

    1991-01-01

    The characterization of selected graphite fiber reinforced epoxy (934 and 5208) and polysulfone (P1700) matrix resin composite materials which received 5 years and 10 months of exposure to the LEO environment on the Long Duration Exposure Facility is reported. Resin loss and a decrease in mechanical performance as well as dramatic visual effects were observed. However, chemical characterization including infrared, thermal, and selected solution property measurements showed that the molecular structure of the polymeric matrix had not changed significantly in response to this exposure. The potential effect of a silicon-containing molecular contamination of these specimens is addressed.

  4. Identification and Selection of Major Carbon Dioxide Stream Compositions

    Energy Technology Data Exchange (ETDEWEB)

    Last, George V.; Schmick, Mary T.

    2011-06-30

    A critical component in the assessment of long-term risk from geologic sequestration of CO2 is the ability to predict mineralogical and geochemical changes within storage reservoirs due to rock-brine-CO2 reactions. Impurities and/or other constituents selected for co-sequestration can affect both the chemical and physical (e.g. density, viscosity, interfacial tension) behavior of CO2 in the deep subsurface. These impurities and concentrations are a function of both the industrial source(s) of the CO2, as well as the carbon capture technology used to extract the CO2 and produce a concentrated stream for geologic sequestration. This report summarizes the relative concentrations of CO2 and other constituents in exhaust gases from major non-energy related industrial sources of CO2. Assuming that carbon-capture technology would remove most of the incondensable gases N2, O2, and Ar, leaving SO2 and NOx as the main impurities, we selected four test fluid compositions for use in geochemical experiments. These included: 1) a pure CO2 stream representative of food grade CO2 used in most enhanced oil recovery projects: 2) a test fluid composition containing low concentrations (0.5 mole %) SO2 and NOx (representative of that generated from cement production), 3) a test fluid composition with higher concentrations (2.5 mole %) of SO2, and 4) and test fluid composition containing 3 mole % H2S.

  5. Accuracy of CT for Selecting Candidates for Coronary Artery Bypass Graft Surgery: Combination with the SYNTAX Score.

    Science.gov (United States)

    Suh, Young Joo; Hong, Yoo Jin; Lee, Hye-Jeong; Hur, Jin; Kim, Young Jin; Hong, Sae Rom; Kim, Tae Hoon; Seo, Jae Seung; Yoo, Kyung-Jong; Chang, Hyuk-Jae; Choi, Byoung Wook

    2015-08-01

    To investigate the diagnostic performance of coronary computed tomographic (CT) angiography for selecting candidates for coronary artery bypass graft (CABG) surgery according to the 2011 American College of Cardiology Foundation (ACCF) and American Heart Association (AHA) guidelines for CABG surgery and determine the added value of SYNTAX (Synergy between PCI with TAXUS and Cardiac Surgery) scoring for selecting CABG surgery candidates. Approval was obtained from the Institutional Review Board, and informed consent was waived for this retrospective study. A total of 399 patients (mean age, 63.8 years; 244 men and 155 women) who underwent both coronary CT angiography and invasive coronary angiography were included. Eligible criteria for CABG surgery were established on the basis of the 2011 ACCF/AHA guidelines. from coronary CT angiography and invasive coronary angiography were retrospectively reviewed, and SYNTAX scores were determined. The diagnostic performance of coronary CT angiography for selecting CABG surgery candidates was calculated with invasive coronary angiography as the reference method. The diagnostic performance of coronary CT angiography alone, the CT-based SYNTAX score, and the combined coronary CT angiography with CT-based SYNTAX score were assessed by using a combination of invasive coronary angiography and invasive coronary angiography-based SYNTAX scores as a reference method. Statistical analyses were performed by using the generalized estimating equation, independent t test, Mann-Whitney U test, Wilcoxon signed rank test, Fisher exact test, and χ(2) statistics. The overall sensitivity, specificity, positive predictive value (PPV), and negative predictive value of coronary CT angiography for selecting CABG surgery candidates were 96.5%, 96.5%, 88.3%, and 99.0%, respectively. When a combination of invasive coronary angiography with an invasive coronary angiography-based SYNTAX score was used as a standard reference, combined coronary CT

  6. Advances in radiation grafting

    International Nuclear Information System (INIS)

    Hegazy, El-Sayed A.; AbdEl-Rehim, H.A.; Kamal, H.; Kandeel, K.A.

    2001-01-01

    Graft copolymerization is an attractive means for modifying base polymers because grafting frequently results in the superposition of properties relating to the backbone and pendent chains. Among the various methods for initiating the grafting reaction, ionizing radiation is the cleanest and most versatile method of grafting available. Ion-exchange membranes play an important role in modern technology, especially in separation and purification of materials. The search for improved membrane composition has considered almost every available polymeric material because of its great practical importance. Grafting of polymers with a mixture of monomers is important since different types of chains containing different functional groups are included. A great deal is focused on the waste treatment of heavy and toxic metals from wastewater because of the severe problems of environmental pollution. Functionalized polymers suitable for metal adsorption with their reactive functional groups such as carboxylic and pyridine groups suitable for waste treatment were prepared by radiation grafting method. More reactive chelating groups were further introduced to the grafted copolymer through its functional groups by chemical treatments with suitable reagents. The advances of radiation grafting and possible uses are briefly discussed

  7. Advances in radiation grafting

    Science.gov (United States)

    Hegazy, El-Sayed A.; AbdEl-Rehim, H. A.; Kamal, H.; Kandeel, K. A.

    2001-12-01

    Graft copolymerization is an attractive means for modifying base polymers because grafting frequently results in the superposition of properties relating to the backbone and pendent chains. Among the various methods for initiating the grafting reaction, ionizing radiation is the cleanest and most versatile method of grafting available. Ion-exchange membranes play an important role in modern technology, especially in separation and purification of materials. The search for improved membrane composition has considered almost every available polymeric material because of its great practical importance. Grafting of polymers with a mixture of monomers is important since different types of chains containing different functional groups are included. A great deal is focused on the waste treatment of heavy and toxic metals from wastewater because of the severe problems of environmental pollution. Functionalized polymers suitable for metal adsorption with their reactive functional groups such as carboxylic and pyridine groups suitable for waste treatment were prepared by radiation grafting method. More reactive chelating groups were further introduced to the grafted copolymer through its functional groups by chemical treatments with suitable reagents. The advances of radiation grafting and possible uses are briefly discussed.

  8. Adsorption affinity and selectivity of 3-ureidopropyltriethoxysilane grafted oil palm empty fruit bunches towards mercury ions.

    Science.gov (United States)

    Kunjirama, Magendran; Saman, Norasikin; Johari, Khairiraihanna; Song, Shiow-Tien; Kong, Helen; Cheu, Siew-Chin; Lye, Jimmy Wei Ping; Mat, Hanapi

    2017-06-01

    This study was conducted to investigate the potential application of oil palm empty fruit branches (OPEFB) as adsorbents to remove organic methylmercurry, MeHg(II), and inorganic Hg(II) from aqueous solution. The OPEFB was functionalized with amine containing ligand namely 3-ureidopropyltriethoxysilane (UPTES) aiming for better adsorption performance towards both mercury ions. The adsorption was found to be dependent on initial pH, initial concentraton, temperatures, and contact time. The maximum adsorption capacities (Q m.exp ) of Hg(II) adsorption onto OPEFB and UPTES-OPEFB were 0.226 and 0.773 mmol/g, respectively. The Q m.exp of MeHg(II) onto OPEFB, however, was higher than UPTES-OPEFB. The adsorption kinetic data obeyed the Elovich model and the adsorption was controlled by the film-diffusion step. The calculated thermodynamic parameters indicate an endothermic adsorption process. Adsorption data analysis indicates that the adsorption mechanism may include ion-exchange, complexation, and physisorption interactions. The potential applications of adsorbents were demonstrated using oilfield produced water and natural gas condensate. The UPTES-OPEFB offered higher selectivity towards both mercury ions than OPEFB. The regenerability studies indicated that the adsorbent could be reused for multiple cycles.

  9. Enhancement of Thermal Stability and Selectivity by Introducing Aminotriazine Comonomer to Poly(Octadecyl Acrylate-Grafted Silica as Chromatography Matrix

    Directory of Open Access Journals (Sweden)

    Abul K. Mallik

    2018-02-01

    Full Text Available This paper introduces a poly(octadecyl acrylate (pODA-based organic phase on silica, which is assisted by 2-vinyl-4,6-diamino-1,3,5-triazine (AT, for a chromatography stationary phase. The ODA-AT copolymer grafting onto silica surface was characterized by elemental analysis, FT-IR spectroscopy, scanning electron microscopy, thermo gravimetric analysis and differential scanning calorimeter (DSC. An endothermic peak top of the copolymer-grafted silica was increased to 46 °C from 38 °C, which was a peak top of pODA homopolymer. For high performance liquid chromatography (HPLC application, the molecular selectivity increased with an increase in the AT contents of the ODA-AT copolymer as organic phase. The co-existence of an aminotriazine moiety in the copolymer promoted side-chain ordering of the poly(octadecyl moiety, thus enhancing molecular planarity selectivity for PAHs in reversed-phase liquid chromatography.

  10. Nutrient composition of selected medicinal leafy vegetables in Western Nigeria.

    Science.gov (United States)

    Ijarotimi, O Steve; Ekeh, Ogechi; Ajayi, O Philip

    2010-04-01

    The objectives of this study were to evaluate the nutritional composition and consumption patterns of selected local leafy vegetables among families in Akure Township, Western Nigeria. The data collection involved administration of interviewer-structured questionnaires to the mothers. The questionnaire was designed to collect information on the medicinal and consumption pattern of vegetables. The chemical compositions of the vegetables were analyzed using standard methods. The nutrient composition of the vegetables showed that the protein content of Jathropha tanjorenses (40.94%) was significantly higher than the remaining leafy vegetable samples, whereas Curcubita pepo (8.25%) contained the least protein content. The fiber content of Solanum americanum (13.79%) was significantly higher when compared with other leafy vegetable samples. Also, the energy value of Baselia allia (401.68 kcal) was the highest, whereas that of C. pepo (285.10 kcal) was the lowest. Regarding mineral composition, J. tanjorenses had the highest contents of zinc, iron, and Na/K ratio, whereas Vernononia amygdalina and Solanum macrocarpon had the least and highest Na/K and Ca/P ratios, respectively. The consumption patterns of the respondents showed that one-quarter of the respondents consumed the vegetables regularly, whereas the remaining consumed occasionally or never consumed the vegetables. In conclusion, this study established that the leafy vegetables contained appreciable amounts of nutrients that could be of health and nutritional benefits to the consumers.

  11. Selective Hg(II) adsorption from aqueous solutions of Hg(II) and Pb(II) by hydrolyzed acrylamide-grafted PET films.

    Science.gov (United States)

    Rahman, Nazia; Sato, Nobuhiro; Sugiyama, Masaaki; Hidaka, Yoshiki; Okabe, Hirotaka; Hara, Kazuhiro

    2014-01-01

    Selective Hg(II) adsorption from aqueous solutions of Hg(II) and Pb(II) using hydrolyzed acrylamide (AAm)-grafted polyethylene terephthalate (PET) films was examined to explore the potential reuse of waste PET materials. Selective recovery of Hg(II) from a mixture of soft acids with similar structure, such as Hg(II) and Pb(II), is important to allow the reuse of recovered Hg(II). An adsorbent for selective Hg(II) adsorption was prepared by γ-ray-induced grafting of AAm onto PET films followed by partial hydrolysis through KOH treatment. The adsorption capacity of the AAm-grafted PET films for Hg(II) ions increased from 15 to 70 mg/g after partial hydrolysis because of the reduction of hydrogen bonding between -CONH2 groups and the corresponding improved access of metal ions to the amide groups. The prepared adsorbent was characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. The absorbent film showed high selectivity for the adsorption of Hg(II) over Pb(II) throughout the entire initial metal concentration range (100-500 mg/L) and pH range (2.2-5.6) studied. The high selectivity is attributed to the ability of Hg(II) ions to form covalent bonds with the amide groups. The calculated selectivity coefficient for the adsorbent binding Hg(II) over Pb(II) was 19.2 at pH 4.5 with an initial metal concentration of 100 mg/L. Selective Hg(II) adsorption equilibrium data followed the Langmuir model and kinetic data were well fitted by a pseudo-second-order equation. The adsorbed Hg(II) and Pb(II) ions were effectively desorbed from the adsorbent film by acid treatment, and the regenerated film showed no marked loss of adsorption capacity upon reuse for selective Hg(II) adsorption.

  12. Conducting electrospun fibres with polyanionic grafts as highly selective, label-free, electrochemical biosensor with a low detection limit for non-Hodgkin lymphoma gene.

    Science.gov (United States)

    Kerr-Phillips, Thomas E; Aydemir, Nihan; Chan, Eddie Wai Chi; Barker, David; Malmstro M, Jenny; Plesse, Cedric; Travas-Sejdic, Jadranka

    2018-02-15

    A highly selective, label-free sensor for the non-Hodgkin lymphoma gene, with an aM detection limit, utilizing electrochemical impedance spectroscopy (EIS) is presented. The sensor consists of a conducting electrospun fibre mat, surface-grafted with poly(acrylic acid) (PAA) brushes and a conducting polymer sensing element with covalently attached oligonucleotide probes. The sensor was fabricated from electrospun NBR rubber, embedded with poly(3,4-ethylenedioxythiophene) (PEDOT), followed by grafting poly(acrylic acid) brushes and then electrochemically polymerizing a conducting polymer monomer with ssDNA probe sequence pre-attached. The resulting non-Hodgkin lymphoma gene sensor showed a detection limit of 1aM (1 × 10 -18 mol/L), more than 400 folds lower compared to a thin-film analogue. The sensor presented extraordinary selectivity, with only 1%, 2.7% and 4.6% of the signal recorded for the fully non-complimentary, T-A and G-C base mismatch oligonucleotide sequences, respectively. We suggest that such greatly enhanced selectivity is due to the presence of negatively charged carboxylic acid moieties from PAA grafts that electrostatically repel the non-complementary and mismatch DNA sequences, overcoming the non-specific binding. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Styrene-Assisted Maleic Anhydride Grafted Poly(lactic acid as an Effective Compatibilizer for Wood Flour/Poly(lactic acid Bio-Composites

    Directory of Open Access Journals (Sweden)

    Jun Du

    2017-11-01

    Full Text Available This study aimed to evaluate the effect of styrene-assisted maleic anhydride-grafted poly(lactic acid (PLA-g-St/MAH on the interfacial properties of wood flour/poly(lactic acid (PLA bio-composites. PLA-g-St/MAH was synthesized by free-radical melt grafting using styrene as a comonomer and dicumyl peroxide as an initiator. The structure of PLA-g-St/MAH was characterized by Fourier transform infrared spectroscopy. Wood flour/PLA composites were prepared by compression molding using PLA-g-St/MAH as a compatibilizer. The effects of PLA-g-St/MAH on the rheological and mechanical properties, as well as on the fractured surface morphology of the composites were investigated. Results indicated that storage modulus, complex viscosity, equilibrium torque, and shear heat were significantly increased. The mechanical properties of the wood flour/PLA composites were also significantly increased after the addition of PLA-g-St/MAH. The maximum values were achieved at the loading rate of 3 wt % because of the improved interfacial adhesion between the wood flour and the PLA matrix.

  14. Impact of public reporting of coronary artery bypass graft surgery performance data on market share, mortality, and patient selection.

    Science.gov (United States)

    Romano, Patrick S; Marcin, James P; Dai, Jian J; Yang, Xiaowei D; Kravitz, Richard L; Rocke, David M; Dharmar, Madan; Li, Zhongmin

    2011-12-01

    The impact of publicly reporting risk-adjusted outcomes for hospitals and surgeons remains controversial, with particular concern about unintended consequences. We evaluated the impact of 3 reports from the voluntary California CABG Mortality Reporting Program (CCMRP) on hospital market share, hospital mortality, and patient selection for coronary artery bypass graft (CABG) surgery. We analyzed data from January 2000 to December 2005 for all patients receiving isolated CABG surgery in California. We compared hospital groups based on their quality classification, including low-mortality outliers ("better"), high-mortality outliers ("worse"), and nonoutliers, as well as participation in the CCMRP. We compared changes in market share, risk-adjusted mortality, and hospital caseload of high-risk patients for isolated CABG surgeries before and after the public release of 3 CCMRP reports (July 2001, August 2003, and February 2005). Low-mortality outlier hospitals experienced significantly increased market share for isolated CABG surgery in the first 6 months after the public release of the CCMRP reports (relative change in adjusted mean market share=8.9%, P=0.002). We found no evidence to suggest reduced risk adjusted mortality after the release of the CCMRP reports, but high-mortality outlier hospitals, on average, operated on less sick patients (relative change in mean expected mortality=25%, P=0.02). The release of public CABG hospital performance reports in California was associated with increased volume at low-mortality hospitals, and may have reduced referrals of high-risk patients to high-mortality hospitals (or risk avoidance).

  15. Integrated ion imprinted polymers-paper composites for selective and sensitive detection of Cd(II) ions

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Kai [State Key Laboratory of Environment Health - Incubation, Key Laboratory of Environment and Health, Ministry of Education, Key Laboratory of Environment and Health Wuhan, Ministry of Environmental Protection, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, #13 Hangkong Road, Hubei, 430030, Wuhan (China); Chen, Ying [Hubei Center for Disease Control and Prevention, No. 6 ZhuoDao Quan North Road, 430079, Wuhan (China); Zhou, Feng [State Key Laboratory of Environment Health - Incubation, Key Laboratory of Environment and Health, Ministry of Education, Key Laboratory of Environment and Health Wuhan, Ministry of Environmental Protection, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, #13 Hangkong Road, Hubei, 430030, Wuhan (China); Zhao, Xiaoya [Hubei Entry-Exit Inspection and Quarantine Bureau of PRC, No.588 Qingtaidadao Road, Hubei, 430022, Wuhan (China); Liu, Jiafa [Hubei Center for Disease Control and Prevention, No. 6 ZhuoDao Quan North Road, 430079, Wuhan (China); Mei, Surong; Zhou, Yikai [State Key Laboratory of Environment Health - Incubation, Key Laboratory of Environment and Health, Ministry of Education, Key Laboratory of Environment and Health Wuhan, Ministry of Environmental Protection, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, #13 Hangkong Road, Hubei, 430030, Wuhan (China); Jing, Tao, E-mail: jingtao@hust.edu.cn [State Key Laboratory of Environment Health - Incubation, Key Laboratory of Environment and Health, Ministry of Education, Key Laboratory of Environment and Health Wuhan, Ministry of Environmental Protection, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, #13 Hangkong Road, Hubei, 430030, Wuhan (China)

    2017-07-05

    Highlights: • IIPs are first grafted on the low-cost A4 print paper to develop an integrated paper-based device. • As an imprinted composite, the adsorption capacity is 155.2 mg g{sup –1} and the imprinted factor is more than 3.0. • As an analytical method, the limit of detection is 0.4 ng mL{sup –1}. • Based on the water quality standards, it could be used to determine Cd(II) ions in drinking water. - Abstract: Paper-based sensor is a new alternative technology to develop a portable, low-cost, and rapid analysis system in environmental chemistry. In this study, ion imprinted polymers (IIPs) using cadmium ions as the template were directly grafted on the surface of low-cost print paper based on the reversible addition-fragmentation chain transfer polymerization. It can be applied as a recognition element to selectively capture the target ions in the complex samples. The maximum adsorption capacity of IIPs composites was 155.2 mg g{sup –1} and the imprinted factor was more than 3.0. Then, IIPs-paper platform could be also applied as a detection element for highly selective and sensitive detection of Cd(II) ions without complex sample pretreatment and expensive instrument, due to the selective recognition, formation of dithizone-cadmium complexes and light transmission ability. Under the optimized condition, the linear range was changed from 1 to 100 ng mL{sup –1} and the limit of detection was 0.4 ng mL{sup –1}. The results were in good agreement with the classic ICP-MS method. Furthermore, the proposed method can also be developed for detection of other heavy metals by designing of new IIPs.

  16. Impact of lenalidomide-based induction therapy on the mobilization of CD34+ cells, blood graft cellular composition, and post-transplant recovery in myeloma patients: a prospective multicenter study.

    Science.gov (United States)

    Partanen, Anu; Valtola, Jaakko; Silvennoinen, Raija; Ropponen, Antti; Siitonen, Timo; Putkonen, Mervi; Sankelo, Marja; Pelkonen, Jukka; Mäntymaa, Pentti; Varmavuo, Ville; Jantunen, Esa

    2017-10-01

    Lenalidomide is an immunomodulatory drug that is also currently used in transplant-eligible patients with multiple myeloma. Previous studies have suggested a negative impact of lenalidomide on the mobilization of CD34 + cells. No data are available regarding the more detailed composition of blood grafts after lenalidomide. In a multicenter, prospective study, we analyzed the mobilization of CD34 + cells, graft cellular composition, and post-transplant hematologic recovery in 26 patients with multiple myeloma after lenalidomide-based induction and in 34 lenalidomide-naive controls with multiple myeloma. All patients were mobilized with low-dose cyclophosphamide plus granulocyte-colony-stimulating factor. The cellular composition of the grafts was analyzed from thawed, cryopreserved samples with flow cytometry. Graft function was evaluated by engraftment data and by complete blood counts until 12 months after the graft infusion. Patients in the lenalidomide arm had lower median peak CD34 + counts and approximately 40% lower CD34 + cell yields from the first apheresis session, but these differences were not significant. The median total number of CD34 + cells collected was comparable (6.4 vs. 7.5 × 10 6 /kg). The number of apheresis sessions was higher in the lenalidomide group (2 vs. 1; p = 0.039). The blood graft composition was comparable between the groups. Hematologic recovery within 12 months post-transplant did not differ between the groups. Lenalidomide-based induction seems to have an impact on the number of aphereses performed, but not on the total yields of the CD34 + cells in the graft. Neither cellular composition of the grafts nor post-transplant recovery was affected by the limited pre-transplant exposure to lenalidomide. © 2017 AABB.

  17. Synthesis of perm-selective membranes by grafting acrylic acid into air-irradiated Teflon-FEP films

    Science.gov (United States)

    Bozzi, Annick; Chapiro, Adolphe

    Grafting acrylic acid into air-irradiated Teflon-FEP films was investigated. Pre-irradiation doses ranged from 0.5 to 10 kGy. Grafting occurred at 45 or 60°C. Homopolymerization inhibitors, ferrous ions or methylene blue, were added to the system. It was found that after completion of the reaction, within 40-100 min, membranes were obtained with very low electric resistivities. The influence of added inhibitors, pre-irradiation dose and grafting temperature was studied. From the results it is concluded that the initiating centers in air-irradiated Teflon-FEP are, on the one hand, peroxides of structure POOP', in which P is a polymeric radical and Pprime; a small fragment, and on the other trapped PO .2 radicals. The latter only react after losing their oxygen. In the presence of polymerization inhibitors, initiation involves a redox process which reduces the overall activation energy.

  18. Nutritional and toxicological composition analysis of selected cassava processed products

    Directory of Open Access Journals (Sweden)

    Kuda Dewage Supun Charuni Nilangeka Rajapaksha

    2017-01-01

    Full Text Available Cassava (Manihot esculanta Crantz is an important food source in tropical countries where it can withstand environmentally stressed conditions. Cassava and its processed products have a high demand in both local and export market of Sri Lanka. MU51 cassava variety is one of the more common varieties and boiling is the main consumption pattern of cassava among Sri Lankans. The less utilization of cassava is due to the presence of cyanide which is a toxic substance. This research was designed to analyse the nutritional composition and toxicological (cyanide content of Cassava MU51 variety and selected processed products of cassava MU51 (boiled, starch, flour, chips, two chips varieties purchased from market to identify the effect of processing on cassava MU51 variety. Nutritional composition was analysed by AOAC (2012 methods with modifications and cyanide content was determined following picric acid method of spectrophotometric determination. The Flesh of MU51 variety and different processed products of cassava had an average range of moisture content (3.18 - 61.94%, total fat (0.31 - 23.30%, crude fiber (0.94 - 2.15%, protein (1.67 - 3.71% and carbohydrates (32.68 - 84.20% and where they varied significantly in between products and the variety MU51, where no significance difference (p >0.05 observed in between MU51 flesh and processed products' ash content where it ranged (1.02 - 1.91%. However, boiled product and MU51 flesh had more similar results in their nutritional composition where they showed no significant difference at any of the nutrient that was analysed. Thus, there could be no significant effect on the nutrient composition of raw cassava once it boiled. Cyanide content of the MU51 flesh and selected products (boiled, starch, flour and chips prepared using MU51 variety, showed wide variation ranging from 4.68 mg.kg-1 to 33.92 mg.kg-1 in dry basis. But except boiled cassava all processed products had cyanide content <10 mg.kg-1, which

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

    DEFF Research Database (Denmark)

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

    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...

  20. Advances in allogenic bone graft processing and usage: preparation and evaluation of chitosan-demineralized cancellous bone powder composite scaffolds as a bone graft substitute

    International Nuclear Information System (INIS)

    Yongyudh Vajaradul

    2008-01-01

    Full text: Demineralized bone matrix (DBM) is currently used by surgeons. It usually exists as a lyophilized powder which is difficult to handle and operated. In this study, we try to improve these disadvantages by combining DBM with a biomaterial. It focuses on a natural biodegradable polymer, chitosan, to act as a temporary matrix for bone growth that easily prepare in any size and shape by using tissue engineering knowledge to get a proper temporary matrix. Thus, the development of chitosan-demineralized bone powder composite scaffold is an alternative way. Polymeric scaffold has been demonstrated to have great potential for tissue engineering because the scaffold or three dimension (3D) construct provides the necessary support for cells to proliferate, extracellular matrix deposition and vascularization of neo-tissue. Moreover, chitosan, a natural cationic polymer which its structural is similar to extracellular matrix glycosaminoblycans, is biodegradable, biocompatible, non-antigenic and biofunctional. It can enhance osteoblast cells proliferation and mineral matrix deposition in culture. The first study was to fabricate and analyze composite scaffold composed of either chitosan-demineralized cancellous bone powders or chitosan-demineralized cancellous cartilage bone powders in a ratio 50:50 and 70:30 w/w (chitosan : bone powders) based on physical properties composing of average pore diameter, mechanical integrity and swelling property. Secondly, scaffolds were evaluated in term of biological properties composing of their ability to support neo osteogenesis, including assessments of cell attachment and viability, cell morphology, and the biosynthesis of extracellular matrix. Results indicated that chitosan-demineralized cancellous bone powder composite scaffolds possessing an interconnecting, porous structure could be easily created through a simple freezing and lyophilization process. (Author)

  1. Development of a pre-vascularized 3D scaffold-hydrogel composite graft using an arterio-venous loop for tissue engineering applications.

    Science.gov (United States)

    Rath, Subha N; Arkudas, Andreas; Lam, Christopher Xf; Olkowski, Radoslaw; Polykandroitis, Elias; Chróscicka, Anna; Beier, Justus P; Horch, Raymund E; Hutmacher, Dietmar W; Kneser, Ulrich

    2012-09-01

    Hyaluronic acid (HA) and fibrin glue (FG) are effective hydrogels for tissue engineering applications as they support tissue in-growth, retain growth factors, and release them slowly with time. The scaffolds, in combination with a hydrogel, effectuate a successful graft. However, the survival of a graft entirely depends upon a functional vascular supply. Therefore, hydrogels must support the in-growing vasculature. To study and compare the vascular patterns, HA and FG hydrogel-containing PLDLLA-TCP-PCL scaffolds were implanted in the groin of male Lewis rats and supplied with a micro-surgically prepared arterio-venous (A-V) loop. The rats were perfused with a vascular contrast media after 4 and 8 weeks and sacrificed for further analysis. The specimens were scanned with micro-CT to find the vascular growth patterns. Corrosion casting of blood vessels followed by SEM demonstrated a high vascular density near the parent blood vessels. Histologically, HA and FG implanted animal groups showed significant angiogenetic activity, especially within the pores of the scaffold. However, formation of new blood vessels was more conspicuously observed at 4 weeks in FG than HA implants. Furthermore, by 8 weeks, the number and pattern of blood vessels were comparable between them. At this time, HA was still present indicating its slow degradation. The finding was confirmed by histomorphometric analysis. This experimental study demonstrates that HA containing composite scaffold systems permit stabile in-growth of blood vessels due to sustained degradation over 8 weeks. HA is a potential matrix for a tissue engineered composite graft.

  2. [Arthroscopy-guided core decompression and bone grafting combined with selective arterial infusion for treatment of early stage avascular necrosis of femoral head].

    Science.gov (United States)

    Guo, Hao-Shan; Tian, Yi-Jun; Liu, Gang; An, Long; Zhou, Zhan-Guo; Liu, Huan-Zhen

    2018-01-25

    To observe the clinical effects of arthroscopy-guided core decompression and bone grafting combined with selective arterial infusion for early stage avascular necrosis of femoral head. From January 2010 to December 2014, 76 patients(76 hips) diagnosed as Ficat II stage avascular necrosis of femoral head were randomly divided into experimental group and control group. In the experimental group, there were 27 males and 8 females aged from 24 to 55 years old with an average of (43.96±6.81) years, treated with arthroscopic-guided core decompression and bone grafting combined with selective arterial infusion. Along the direction of the femoral neck, an 8 mm-diameter tunnel to necrotic areas was drilled, then curettage of necrotic bone was performed under arthroscope, and the iliac bone was grafted. In the control group, there were 29 males and 12 females aged from 26 to 56 years old with an average of (44.62±7.33) years, treated with percutaneous core decompression combined with selective arterial infusion. The preoperative and postoperative Harris scores were recorded and the changes of X-rays were analyzed. All the patients were followed up with an average of 30 months. Postoperative follow-up at 12 months showed that there was significant difference in imaging outcome between two groups( P 0.05), but there was significant difference in postoperative Harris score( P necrosis are effective. Using arthroscopic-guided core decompression method, the necrotic bone can be positioned and scraped more accurately, and can obtain better results. Copyright© 2018 by the China Journal of Orthopaedics and Traumatology Press.

  3. Improvement of Thermo-Mechanical Properties of Short Natural Fiber Reinforced Recycled Polypropylene Composites through Double Step Grafting Process

    Science.gov (United States)

    Saputra, O. A.; Rini, K. S.; Susanti, T. D.; Mustofa, R. E.; Prameswari, M. D.; Pramono, E.

    2017-07-01

    This study focused on the effect of a compatibilizer addition, maleic anhydrides (MAH) on mechanical, thermal and water absorption properties of oil palm empty fruit bunches (EFB) fiber reinforced recycled polypropylene (rPP) biocomposites. The double steps grafting process were conducted by incorporated MAH on both rPP and EFB to improve the surface adhesion between these materials, to result in a good mechanical properties as well as biocompatibility to nature. The chemical test was carried out using FTIR (Fourier Transform Infra-Red) spectroscopy technique to evaluated grafting process. The mechanical test was investigated and found that the addition of 10 phr MAH to both rPP and EFB improved mechanical strength of the biocomposites higher than another formulas. In this study, thermal properties of biocomposites also characterized. Water absorption (WA) analysis showed the presence of EFB fiber increased the water uptake of the material.

  4. VARIATION IN LIQUID WASTE COMPOSITION SUPPLYING SELECTED COLLECTION POINT

    Directory of Open Access Journals (Sweden)

    Elżbieta Halina Grygorczuk-Petersons

    2014-12-01

    Full Text Available The problem of liquid wastes is still current not only in Poland, but also in the world. The primary source of liquid wastes are single-family and multi-family houses. To a lesser extent, public service or production facilities, mainly in urban areas, are equipped with no-outlet reservoirs. Low concentrations in liquid wastes and their high density are often some difficulty to work with not only by sewage treatment plants, but also collection points. Therefore, the knowledge of the composition of liquid wastes supplied to the collection points is important. The paper presents the results of research as well as variability of concentrations of selected parameters of liquid wastes supplied to the collection point in Bialystok, that accepts both municipal and industrial sewage. Statistical processing of the obtained results and those derived from The Waterworks Bialystok showed the presence of high variability of total suspended matter and electrolytic conductivity as well as organic impurities expressed as BOD5 and COD.

  5. Surface modification of cation exchange membranes by graft polymerization of PAA-co-PANI/MWCNTs nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Nemati, Mahsa; Hosseini, Sayed Mohsen; Bagheripour, Ehsan [Faculty of Engineering, Arak University, Arak (Iran, Islamic Republic of); Madaeni, Sayed Siavash [Faculty of Engineering, Razi University, Kermanshah (Iran, Islamic Republic of)

    2016-03-15

    Surface modification of polyvinylchloride based heterogeneous cation exchange membrane was performed by graft polymerization of PAA and PAA-co-PANI/MWCNTs nanoparticles. The ion exchange membranes were prepared by solution casting technique. Spectra analysis confirmed graft polymerization clearly. SEM images illustrated that graft polymerization covers the membranes by simple gel network entanglement. The membrane water content was decreased by graft polymerization of PAA-co-PANI/MWCNTs nanoparticles on membrane surface. Membrane transport number and selectivity declined initially by PAA graft polymerization and then began to increase by utilizing of composite nanoparticles in modifier solution. The sodium and barium flux was improved sharply by PAA and PAAco- 0.01%wt PANI/MWCNTs graft polymerization on membrane surface and then decreased again by more increase of PANI/MWCNTs nanoparticles content ratio in modifier solution. The electrodialysis experiment results in laboratory scale showed higher dialytic rate in heavy metals removal for grafted-PAA and grafted-PAA-co-PANI/MWCNTs modified membrane compared to pristine one. Membrane areal electrical resistance was also decreased by introducing graft polymerization of PAA and PAA-co-PANI/MWCNTs NPs on membrane surface.

  6. Environmental application of radiation grafting

    International Nuclear Information System (INIS)

    Tamada, Masao

    2007-01-01

    Adsorbent having high selectivity against a certain metal ion was synthesized by means of radiation-induced graft polymerization for the purpose of environmental application. The resulting adsorbents were utilized for the removal of toxic metal from scallop waste and the collection of uranium from seawater. As a novel application of grafting, the biodegradability of poly-hydroxybutylate was controlled by grafting. The biodegradability could be depressed by the graft chain and then recovered by external stimuli such as thermal and chemical treatments. (author)

  7. Two-component spin-coated Ag/CNT composite films based on a silver heterogeneous nucleation mechanism adhesion-enhanced by mechanical interlocking and chemical grafting

    Science.gov (United States)

    Zhang, Yang; Kang, Zhixin; Bessho, Takeshi

    2017-03-01

    In this paper, a new method for the synthesis of silver carbon nanotube (Ag/CNT) composite films as conductive connection units for flexible electronic devices is presented. This method is about a two-component solution process by spin coating with an after-treatment annealing process. In this method, multi-walled carbon nanotubes (MWCNTs) act as the core of silver heterogeneous nucleation, which can be observed and analyzed by a field-emission scanning electron microscope. With the effects of mechanical interlocking, chemical grafting, and annealing, the interfacial adhesive strength between films and PET sheets was enhanced to 12 N cm-1. The tensile strength of the Ag/CNT composite films was observed to increase by 38% by adding 5 g l-1 MWCNTs. In the four-probe method, the resistivity of Ag/CNT-5 declined by 78.2% compared with pristine Ag films. The anti-fatigue performance of the Ag/CNT composite films was monitored by cyclic bending deformation and the results revealed that the growth rate of electrical resistance during the deformation was obviously retarded. As for industrial application, this method provides an efficient low-cost way to prepare Ag/CNT composite films and can be further applied to other coating systems.

  8. Effect of rose water on structural, optical and electrical properties of composites of reduced graphene oxide-poly (vinyl alcohol) (PVA) grafted with silver nanoparticles

    Science.gov (United States)

    Kumar, Devender; Wadhwa, Heena; Mahendia, Suman; Chand, Fakir; Kumar, Shyam

    2017-02-01

    In this work, nanocomposites of reduced graphene oxide-poly (vinyl alcohol) (PVA) grafted with silver nanoparticles (rGO-PVA-Ag) were prepared in the absence and presence of rose water. The optical characterizations of prepared nanocomposites were done through UV-visible spectroscopy and Transmission Electron Microscopy (TEM) and Raman spectroscopy was employed for the surface characterization. The grafted silver (Ag) nanoparticles are found to be almost spherical in shape with reduction in their mean diameter from 47 nm to 26 nm after addition of rose water. The UV-visible absorption spectra of as-prepared rGO-PVA-Ag nanocomposites without and with rose water depicted surface plasmon resonance (SPR) peak at around 448 nm which coincides with the predicted spectra from simulation based on the Mie Theory. The electrical dc conductivity measurements as the function of temperature from room temperature to 55 °C were investigated. It has been found that use of rose water in synthesis process increases the electrical conductivity of the rGO-PVA-Ag. The mode of the electrical conduction in the composites can be explained using Efros-Shklovskii Variable Range Hopping mechanism (ES VRH).

  9. Aortic root surgery in Marfan syndrome: Bentall procedure with the composite mechanical valved conduit versus aortic valve reimplantation with Valsalva graft.

    Science.gov (United States)

    Nardi, Paolo; Pellegrino, Antonio; Versaci, Francesco; Mantione, Ludmilla; Polisca, Patrizio; Iorio, Fiore S; Chiariello, Luigi

    2010-09-01

    The aim of the study is to compare mid-term results of Bentall aortic root replacement with composite mechanical valved conduit and aortic valve reimplantation procedure using the Valsalva graft for the treatment of aortic root aneurysm in patients with Marfan syndrome. We retrospectively compared data of 23 patients (mean age 38 + or - 14 years) who had undergone the Bentall procedure (group B) to those of 24 patients (mean age 36 + or - 12 years) who had undergone aortic valve reimplantation (group R) during a 14-year period. Follow-up (mean duration 65 + or - 44 months) was 100% complete. There were no operative deaths in either group. In group B, as compared with group R, preoperative aortic insufficiency (3.2 + or - 1.1/4 vs. 1.7 + or - 1.4/4, P Marfan patients, the Bentall procedure is associated with excellent mid-term outcome. The reimplantation technique, adopted for less dilated aortas, provides similarly satisfactory results. The Valsalva graft seems, with time, to allow a stable aortic valve function.

  10. A Bone Sample Containing a Bone Graft Substitute Analyzed by Correlating Density Information Obtained by X-ray Micro Tomography with Compositional Information Obtained by Raman Microscopy

    Directory of Open Access Journals (Sweden)

    Johann Charwat-Pessler

    2015-06-01

    Full Text Available The ability of bone graft substitutes to promote new bone formation has been increasingly used in the medical field to repair skeletal defects or to replace missing bone in a broad range of applications in dentistry and orthopedics. A common way to assess such materials is via micro computed tomography (µ-CT, through the density information content provided by the absorption of X-rays. Information on the chemical composition of a material can be obtained via Raman spectroscopy. By investigating a bone sample from miniature pigs containing the bone graft substitute Bio Oss®, we pursued the target of assessing to what extent the density information gained by µ-CT imaging matches the chemical information content provided by Raman spectroscopic imaging. Raman images and Raman correlation maps of the investigated sample were used in order to generate a Raman based segmented image by means of an agglomerative, hierarchical cluster analysis. The resulting segments, showing chemically related areas, were subsequently compared with the µ-CT image by means of a one-way ANOVA. We found out that to a certain extent typical gray-level values (and the related histograms in the µ-CT image can be reliably related to specific segments within the image resulting from the cluster analysis.

  11. Composite load spectra for select space propulsion structural components

    Science.gov (United States)

    Newell, J. F.; Ho, H. W.; Kurth, R. E.

    1991-01-01

    The work performed to develop composite load spectra (CLS) for the Space Shuttle Main Engine (SSME) using probabilistic methods. The three methods were implemented to be the engine system influence model. RASCAL was chosen to be the principal method as most component load models were implemented with the method. Validation of RASCAL was performed. High accuracy comparable to the Monte Carlo method can be obtained if a large enough bin size is used. Generic probabilistic models were developed and implemented for load calculations using the probabilistic methods discussed above. Each engine mission, either a real fighter or a test, has three mission phases: the engine start transient phase, the steady state phase, and the engine cut off transient phase. Power level and engine operating inlet conditions change during a mission. The load calculation module provides the steady-state and quasi-steady state calculation procedures with duty-cycle-data option. The quasi-steady state procedure is for engine transient phase calculations. In addition, a few generic probabilistic load models were also developed for specific conditions. These include the fixed transient spike model, the poison arrival transient spike model, and the rare event model. These generic probabilistic load models provide sufficient latitude for simulating loads with specific conditions. For SSME components, turbine blades, transfer ducts, LOX post, and the high pressure oxidizer turbopump (HPOTP) discharge duct were selected for application of the CLS program. They include static pressure loads and dynamic pressure loads for all four components, centrifugal force for the turbine blade, temperatures of thermal loads for all four components, and structural vibration loads for the ducts and LOX posts.

  12. Chemical composition of buckwheat plant parts and selected buckwheat products

    Directory of Open Access Journals (Sweden)

    Petra Vojtíšková

    2014-11-01

    Full Text Available Chemical composition plant parts (roots, stalks, leaves, blossoms of common buckwheat (Fagopyrum esculentum Moench and selected products made from its seeds (peels, whole seed, wholemeal flour, broken seeds, crunchy products Natural and Cocoa, flour, and pasta was determined. Samples were dried and ground to a fine powder. All analyses were performed according to the Commission Regulation no. 152/2009, while rutin concentration was determined by the modified HPLC method. The lowest content of moisture was found in roots (4.3% and in peels (almost 8% and the highest moisture (nearly 11% was discovered in seeds. The lowest amount of crude protein (3.5% was found in peels, the highest crude protein amount (>13% in both flours and leaves (23%. The starch content (>50% in dry matter differs from one sample to another. Only in peels the content of starch was about 3.5%. From all examined samples, the lowest content of fat was found in crunchy products Cocoa, 1.7%. The lowest amount of histidine was determined in all studied samples, except peels, the highest content of glutamic acid was determined in almost all samples, except peels. Whole-meal flour is very rich source of Ca and Fe. The content of these elements was 1172 mg.kg-1 and 45.9 mg.kg-1, respectively. On the other hand, the highest content of Pb (>1 mg.kg-1 was found in broken seeds. The greatest concentration of rutin was determined in blossoms and leaves (83.6 and 69.9 mg.g-1, respectively. On the other hand, the lowest concentrations of rutin were found in buckwheat products (generally less then 1 mg.g-1, i.e. in wholemeal flour, 702 μg.kg-1, the lowest almost 10 μg.kg-1 in pasta.

  13. Dynamic-definition male pectoral reshaping and enhancement in slim, athletic, obese, and gynecomastic patients through selective fat removal and grafting.

    Science.gov (United States)

    Hoyos, Alfredo; Perez, Mauricio

    2012-10-01

    One of the most appealing characteristics of an athletic male body is a well-defined pectoral area. For decades, implants have been the gold standard method for the treatment of this area, but it is not suitable for every case. The goal was to design a mixed technique combining autologous fat extraction and grafting in an anatomically guided fashion to produce a highly athletic contour in the male pectoral. The patient criteria included a body mass index (BMI) lower than 30 kg/m(2), adequate skin tone, and general good health. A three-phase procedure was performed, beginning with infiltration of tumescent solution and followed by fragmentation of extra fat in an anatomic fashion using internal third-generation ultrasound; extraction that blends deep, intermediate, and superficial fat removal; and multilayer fat grafting in the pectoral area. In the presence of gynecomastia, a selective pull-through technique was used in an anatomic manner. In a series of 154 consecutive male patients, the minor complications (n = 15) included asymmetries (n = 10) and residual gynecomastia (n = 5). The major complications (n = 3) included unilateral hematoma (n = 2), and abscess that required sonographic-guided removal (n = 1). An appealing muscular contour was produced in most patients, and the satisfaction rate was very high. Implants are no longer the only option for defining and augmenting the male chest. Combining fat grafting in a multilayer fashion with precise anatomic fat and gland removal achieved a contoured and athletic male pectoral in a safe and reproducible manner. This journal requires that authors assign a level of evidence to each article.

  14. Nanotube/Polymer Composites: Materials Selection and Process Design

    National Research Council Canada - National Science Library

    Winey, Karen

    2004-01-01

    ...) define processing methods most appropriate for the materials identified. Our study of SWNT-polymer composites focuses on thermoplastics, because these materials can be readily drawn into fibers...

  15. Electrospun composite nanofiber membrane of poly(l-lactide) and surface grafted chitin whiskers: Fabrication, mechanical properties and cytocompatibility.

    Science.gov (United States)

    Liu, Hua; Liu, Wenjun; Luo, Binghong; Wen, Wei; Liu, Mingxian; Wang, Xiaoying; Zhou, Changren

    2016-08-20

    To improve both the mechanical properties and cytocompatibility of poly(l-lactide) (PLLA), rod-like chitin whiskers (CHWs) were prepared, and subsequently surface modified with l-lactide to obtain grafted CHWs (g-CHWs). Then, CHWs and g-CHWs were further introduced into PLLA matrix to fabricate CHWs/PLLA and g-CHWs/PLLA nanofiber membranes by electrospinning technique. Morphologies and properties of the CHWs and g-CHWs were characterized. The surface-grafted PLLA chains played an important role in improving interfacial interaction between the whiskers and PLLA matrix. The g-CHWs dispersed more uniformly in matrix than CHWs, and the as-prepared g-CHWs/PLLA nanofiber membrane showed relative smooth and uniform fiber. As a result, the tensile strength and modulus of the g-CHWs/PLLA nanofiber membrane were obviously superior to those of the pure PLLA and CHWs/PLLA nanofiber membranes. Cells culture results indicated that g-CHWs/PLLA nanofiber membrane is more effectively in promoting MC3T3-E1 cells adhesion, spreading and proliferation than pure PLLA and CHWs/PLLA nanofiber membrane. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Volatile composition of Carignan noir wines from ungrafted and grafted onto País (Vitis vinifera L.) grapevines from ten wine-growing sites in Maule Valley, Chile.

    Science.gov (United States)

    Gutiérrez-Gamboa, G; Garde-Cerdán, T; Carrasco-Quiroz, M; Pérez-Álvarez, E P; Martínez-Gil, A M; Del Alamo-Sanza, M; Moreno-Simunovic, Y

    2018-02-09

    Carignan noir is one of the minor and ancient varieties from the Chilean wine scenario, which has had a resurgence due to its rediscovered oenological potential when cultivated under the conditions of the interior dryland area. Under these growing conditions Carignan noir wines stand out as fruit driven and fresh when compared to those coming from other growing areas. On the other hand, it is well known that wine aroma composition depends mainly on variety, viticultural management, and winemaking. Thus, the aim of this work was to study volatile composition of wines from Carignan noir grapes coming from ungrafted and grafted onto País grapevines, in ten sites of the Maule Valley (Chile) during two consecutive vintages. Higher alcohols were the most abundant volatile compounds whereas, ethyl esters and ß-damascenone were the most odoriferous compounds according to their OAV. The dominant factor in Carignan noir wine volatile composition was season, whereas rootstock did not have a significant effect in differentiating the wines. In terms of climate, cold nights during the month prior to harvest correlated with higher linalool, α-terpineol and trans-3-hexen-1-ol content. Biologically effective degree-days index was inversely correlated with isoamyl acetate and 2-phenylethyl acetate content. Huglin's Heliothermal and the Average Mean Temperature of the Warmest Month indexes were inversely correlated with ethyl vanillate, ethyl hexanoate and ethyl octanoate content. Site climate conditions were related to the accumulation of certain wine volatile compounds. This information may be useful for devising new Carignan noir vineyard management strategies in order to improve wine quality or to adjust site selection approaches in order to maximize grape/wine volatile composition according to wine style. This article is protected by copyright. All rights reserved.

  17. Design and rationale for a randomised comparison of everolimus-eluting stents and coronary artery bypass graft surgery in selected patients with left main coronary artery disease: the EXCEL trial.

    Science.gov (United States)

    Kappetein, Arie Pieter; Serruys, Patrick W; Sabik, Joseph F; Leon, Martin B; Taggart, David P; Morice, Marie-Claude; Gersh, Bernard J; Pocock, Stuart J; Cohen, David J; Wallentin, Lars; Ben-Yehuda, Ori; van Es, Gerrit-Anne; Simonton, Charles A; Stone, Gregg W

    2016-09-18

    Coronary artery bypass graft (CABG) surgery is the standard of care for revascularisation of patients with left main coronary artery disease (LMCAD). Recent studies have suggested that percutaneous coronary intervention (PCI) with drug-eluting stents (DES) may provide comparable outcomes in selected patients with LMCAD without extensive CAD. We therefore designed a trial to investigate whether PCI with XIENCE cobalt-chromium everolimus-eluting stents (CoCr-EES) would result in non-inferior or superior clinical outcomes to CABG in selected patients with LMCAD. The Evaluation of XIENCE versus Coronary Artery Bypass Surgery for Effectiveness of Left Main Revascularization (EXCEL) trial is a prospective, open-label, multicentre, international study of 1,900 randomised subjects. Patients with significant LMCAD with a SYNTAX score ≤32 and local Heart Team consensus that the subject is appropriate for revascularisation by both PCI and CABG are consented and randomised 1:1 to undergo PCI using CoCr-EES or CABG. All patients undergo follow-up for five years. The primary endpoint is the three-year composite rate of death, stroke or myocardial infarction, assessed at a median follow-up of at least three years (with at least two-year follow-up in all patients), powered for sequential non-inferiority and superiority testing. The EXCEL study will define the contemporary roles of CABG and PCI using XIENCE CoCr-EES in patients with LMCAD disease with low and intermediate SYNTAX scores.

  18. Bentall Operation in a Patient With Severe Hemophilia A and Marfan Syndrome by Use of a Biologic Composite Graft.

    Science.gov (United States)

    Yildirim, Funda; Ozbakkaloglu, Alper; Ozturk, Tulun; Tetik, Omer

    2016-03-01

    We describe a patient with severe hemophilia A and Marfan syndrome who underwent an elective Bentall operation. Because of the severe hemophilia, anticoagulation could not be given postoperatively; thus, a biologic Valsalva conduit graft was used. During the procedure, factor VIII was given as a bolus dose just before incision, then by continous infusion intraoperatively to maintain the factor VIII activity level between 200% and 300%. Minimal postoperative bleeding occurred. The infusion was continued postoperatively at a lower dose until all chest tubes, pacing wires, and invasive catheters were removed. The patient was discharged on postoperative day 7 without adverse events. Copyright © 2016 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  19. Influence of the electronic distribution of polymers in the spatial conformation of polymer grafted carbon nanotube composites

    Energy Technology Data Exchange (ETDEWEB)

    Garate, H. [Universidad de Buenos Aires, FCEyN, Depto. de Fisica IFIBA-CONICET LPyMC, Pabellon I, Buenos Aires 1428 (Argentina); Universidad de Buenos Aires, FCEyN, Depto. de Quimica Organica, (CIHIDECAR-CONICET) Buenos Aires 1428 (Argentina); De Falco, A. [Universidad de Buenos Aires, FCEyN, Depto. de Fisica IFIBA-CONICET LPyMC, Pabellon I, Buenos Aires 1428 (Argentina); Moreno, M.S. [Centro Atomico Bariloche, 8400 S.C. de Bariloche (Argentina); Fascio, M.L. [Universidad de Buenos Aires, FCEyN, Depto. de Quimica Organica, (CIHIDECAR-CONICET) Buenos Aires 1428 (Argentina); Goyanes, S. [Universidad de Buenos Aires, FCEyN, Depto. de Fisica IFIBA-CONICET LPyMC, Pabellon I, Buenos Aires 1428 (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina); D' Accorso, N.B., E-mail: norma@qo.fcen.uba.ar [Universidad de Buenos Aires, FCEyN, Depto. de Quimica Organica, (CIHIDECAR-CONICET) Buenos Aires 1428 (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina)

    2012-08-15

    In this work we report the covalent functionalization of multiwalled carbon nanotubes (MWCNTs) with polyacrylonitrile (PAN) and polyvinylpyridine (PVP) by the graft from method. Differences in the electronic distribution of both polymers resulted in different interaction between polymers and the nanotubes. It was found that PVP chains wrapped the nanotubes while nanotubes functionalized with PAN presented PAN chains forming amorphous entanglements on the nanoscale linked to the MWCNTs. Differences in the conformation between both polymers and the MWCNTs can be attributed to interactions between the aromatic groups in PVP and the MWCNTs through {pi}-{pi} stacking. The absence of aromatic groups in the case of the PAN chains favours the interaction between them. The functionalization efficiency was characterized using Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA) and UV-vis spectroscopy, while morphological changes were characterized by high resolution transmission electron microscopy.

  20. Novel additives in radiation polymerisation processes. Significance of molecular weight data in their application to grafting, curing and composite formation

    International Nuclear Information System (INIS)

    Garnett, J.L.; Mohajerani, S.; Viengkhou, V.; Loo-Teck NG

    1995-01-01

    The role of additives in accelerating rates of reaction has been investigated in the following related radiation polymerisation processes, i.e simple homopolymerisation, grafting, WPC formation and curing. Additives used include mineral acid, polyfunctional monomers, urea and thermal and photochemical initiators. Molecular weight analysis carried out on the polymers formed in the presence of the additives indicate that both chemical and physical processes are involved in the mechanism of the polymerisation reaction. Chemical processes (free radicals) lead to an enhancement in initial rate of polymerisation whilst the physical parameter involves partitioning of reagents during reaction. Both chemical and physical processes are shown to act in concert to influence both polymer yield and properties

  1. Surgery of the aortic root: should we go for the valve-sparing root reconstruction or the composite graft-valve replacement is still the first choice of treatment for these patients?

    Science.gov (United States)

    Lamana, Fernando de Azevedo; Dias, Ricardo Ribeiro; Duncan, Jose Augusto; Faria, Leandro Batisti de; Malbouisson, Luiz Marcelo Sa; Borges, Luciano de Figueiredo; Mady, Charles; Jatene, Fábio Biscegli

    2015-01-01

    To compare the results of the root reconstruction with the aortic valve-sparing operation versus composite graft-valve replacement. From January 2002 to October 2013, 324 patients underwent aortic root reconstruction. They were 263 composite graft-valve replacement and 61 aortic valve-sparing operation (43 reimplantation and 18 remodeling). Twenty-six percent of the patients were NYHA functional class III and IV; 9.6% had Marfan syndrome, and 12% had bicuspid aortic valve. There was a predominance of aneurysms over dissections (81% vs. 19%), with 7% being acute dissections. The complete follow-up of 100% of the patients was performed with median follow-up time of 902 days for patients undergoing composite graft-valve replacement and 1492 for those undergoing aortic valve-sparing operation. In-hospital mortality was 6.7% and 4.9%, respectively for composite graft-valve replacement and aortic valve-sparing operation (ns). During the late follow-up period, there was 0% moderate and 15.4% severe aortic regurgitation, and NYHA functional class I and II were 89.4% and 94%, respectively for composite graft-valve replacement and aortic valve-sparing operation (ns). Root reconstruction with aortic valve-sparing operation showed lower late mortality (P=0.001) and lower bleeding complications (P=0.006). There was no difference for thromboembolism, endocarditis, and need of reoperation. The aortic root reconstruction with preservation of the valve should be the operation being performed for presenting lower late mortality and survival free of bleeding events.

  2. Radiation grafting on natural films

    Science.gov (United States)

    Lacroix, M.; Khan, R.; Senna, M.; Sharmin, N.; Salmieri, S.; Safrany, A.

    2014-01-01

    Different methods of polymer grafting using gamma irradiation are reported in the present study for the preparation of newly functionalized biodegradable films, and some important properties related to their mechanical and barrier properties are described. Biodegradable films composed of zein and poly(vinyl alcohol) (PVA) were gamma-irradiated in presence of different ratios of acrylic acid (AAc) monomer for compatibilization purpose. Resulting grafted films (zein/PVA-g-AAc) had their puncture strength (PS=37-40 N mm-1) and puncture deformation (PD=6.5-9.8 mm) improved for 30% and 50% PVA in blend, with 5% AAc under 20 kGy. Methylcellulose (MC)-based films were irradiated in the presence of 2-hydroxyethyl methacrylate (HEMA) or silane, in order to determine the effect of monomer grafting on the mechanical properties of films. It was found that grafted films (MC-g-HEMA and MC-g-silane) using 35% monomer performed higher mechanical properties with PS values of 282-296 N mm-1 and PD of 5.0-5.5 mm under 10 kGy. Compatibilized polycaprolactone (PCL)/chitosan composites were developed via grafting silane in chitosan films. Resulting trilayer grafted composite film (PCL/chitosan-g-silane/PCL) presented superior tensile strength (TS=22 MPa) via possible improvement of interfacial adhesion (PCL/chitosan) when using 25% silane under 10 kGy. Finally, MC-based films containing crystalline nanocellulose (CNC) as a filling agent were prepared and irradiated in presence of trimethylolpropane trimethacrylate (TMPTMA) as a grafted plasticizer. Grafted films (MC-g-TMPTMA) presented superior mechanical properties with a TS of 47.9 MPa and a tensile modulus (TM) of 1792 MPa, possibly due to high yield formation of radicals to promote TMPTMA grafting during irradiation. The addition of CNC led to an additional improvement of the barrier properties, with a significant 25% reduction of water vapor permeability (WVP) of grafted films.

  3. Nutrient composition of selected traditional native American plant foods

    Science.gov (United States)

    Ten wild plants (cattail narrow leaf shoots, chokecherries, beaked hazelnuts, lambsquarters, plains pricklypear, prairie turnips, stinging nettles, wild plums, raspberries, rose hips) from three Native American reservations in North Dakota were analyzed to expand composition information of tradition...

  4. Radiochemical grafting of acryonitrile on polystyrene

    International Nuclear Information System (INIS)

    Jendrychowska-Bonamour, A.M.; Michot, C.

    1977-01-01

    Polystyrene polyacrylonitrile copolymers have been prepared by the direct radio-induced grafting method. The reaction has been carried out in a gel of polystyrene swollen by the monomer. The ungrafted polystyrene has been extracted by toluene. It has been possible to separate grafted copolymers from homopolymer traces, despite the very strong dipole-dipole interactions exhibited in solution between polyacrylonitrile chains; afterwards these grafted copolymers were fractionated by composition. The limits of solubility and the glass transition temperatures of the grafted copolymers have been determined. The properties of grafted copolymers have been compared with those of block polyacrylonitrile copolymers. (authors)

  5. Plant grafting: new mechanisms, evolutionary implications

    Directory of Open Access Journals (Sweden)

    Eliezer E Goldschmidt

    2014-12-01

    Full Text Available Grafting, an old plant propagation practice, is still widely used with fruit trees and in recent decades also with vegetables. Taxonomic proximity is a general prerequisite for successful graft-take and long-term survival of the grafted, composite plant. However, the mechanisms underlying interspecific graft incompatibility are as yet insufficiently understood. Hormonal signals, auxin in particular, are believed to play an important role in the wound healing and vascular regeneration within the graft union zone. Long-distance protein, mRNA and small RNA graft-transmissible signals currently emerge as novel mechanisms which regulate nutritional and developmental root/top relations and may play a pivotal role in grafting physiology. Grafting also has significant pathogenic projections. On one hand, stock to scion mechanical contact enables the spread of diseases, even without a complete graft union. But, on the other hand, grafting onto resistant rootstocks serves as a principal tool in the management of fruit tree plagues and vegetable soil-borne diseases. The ‘graft hybrid’ historic controversy has not yet been resolved. Recent evidence suggests that epigenetic modification of DNA-methylation patterns may account for certain graft-transformation phenomena. Root grafting is a wide spread natural phenomenon; both intraspecific and interspecific root grafts have been recorded. Root grafts have an evolutionary role in the survival of storm-hit forest stands as well as in the spread of devastating diseases. A more fundamental evolutionary role is hinted by recent findings that demonstrate plastid and nuclear genome transfer between distinct Nicotiana species in the graft union zone, within a tissue culture system. This has led to the formation of alloploid cells that, under laboratory conditions, gave rise to a novel, alloploid Nicotiana species, indicating that natural grafts may play a role in plant speciation. under certain circumstances.

  6. Plant grafting: new mechanisms, evolutionary implications.

    Science.gov (United States)

    Goldschmidt, Eliezer E

    2014-01-01

    Grafting, an old plant propagation practice, is still widely used with fruit trees and in recent decades also with vegetables. Taxonomic proximity is a general prerequisite for successful graft-take and long-term survival of the grafted, composite plant. However, the mechanisms underlying interspecific graft incompatibility are as yet insufficiently understood. Hormonal signals, auxin in particular, are believed to play an important role in the wound healing and vascular regeneration within the graft union zone. Incomplete and convoluted vascular connections impede the vital upward and downward whole plant transfer routes. Long-distance protein, mRNA and small RNA graft-transmissible signals currently emerge as novel mechanisms which regulate nutritional and developmental root/top relations and may play a pivotal role in grafting physiology. Grafting also has significant pathogenic projections. On one hand, stock to scion mechanical contact enables the spread of diseases, even without a complete graft union. But, on the other hand, grafting onto resistant rootstocks serves as a principal tool in the management of fruit tree plagues and vegetable soil-borne diseases. The 'graft hybrid' historic controversy has not yet been resolved. Recent evidence suggests that epigenetic modification of DNA-methylation patterns may account for certain graft-transformation phenomena. Root grafting is a wide spread natural phenomenon; both intraspecific and interspecific root grafts have been recorded. Root grafts have an evolutionary role in the survival of storm-hit forest stands as well as in the spread of devastating diseases. A more fundamental evolutionary role is hinted by recent findings that demonstrate plastid and nuclear genome transfer between distinct Nicotiana species in the graft union zone, within a tissue culture system. This has led to the formation of alloploid cells that, under laboratory conditions, gave rise to a novel, alloploid Nicotiana species, indicating

  7. Gender and age-dependent differences in body composition changes in response to cardiac rehabilitation exercise training in patients after coronary artery bypass grafting

    Directory of Open Access Journals (Sweden)

    Małgorzata Socha

    2017-09-01

    Full Text Available Cardiac rehabilitation (CR is the standard procedure in persons after coronary artery bypass grafting (CABG. Its basic aim is to combat coronary heart disease (CHD risk factors through physical activity and normalization of body mass. Many authors highlight the differences in response to training in CR as dependent on gender, age and occurrence of accompanying disease. The aim of this study is to assess the effectiveness of a three-week early CR in reference to changing body composition parameters in patients over 50 years of age. The study involved a random group of 65 patients (44 men and 21 women between the ages of 50–76 (average: 62.6 ± 7.2 years with CHD following CABG. Anthropometric and body composition (bioelectrical impedance method measurements were taken at the commencement of CR and after the training programme. After CR, body mass and body mass index were reduced in men < 65 and ≥ 65 years, and in women <65 years. A reduction % body fat and increase % fat free mass and % total body water was observed only in patients <65. years. Furthermore, in men < 65 years, an increase in % body cell mass was observed. In women ≥ 65 years, no statistically significant changes were observed in body fat indices and body composition features between initial and final study. Patients ≥ 65 years of age following surgery over a period of hospital cardiac rehabilitation do not experience the same significant improvement in body composition parameters associated with risk of CHD as middle-aged adults. Older women post-cardiac surgery are characterized by a higher disability index in relation to tolerance to physical stress in comparison with men of the same age and persons < 65 years of age.

  8. Gender and age-dependent differences in body composition changes in response to cardiac rehabilitation exercise training in patients after coronary artery bypass grafting.

    Science.gov (United States)

    Socha, Małgorzata; Wronecki, Krzysztof; Sobiech, Krzysztof A

    2017-09-21

    Cardiac rehabilitation (CR) is the standard procedure in persons after coronary artery bypass grafting (CABG). Its basic aim is to combat coronary heart disease (CHD) risk factors through physical activity and normalization of body mass. Many authors highlight the differences in response to training in CR as dependent on gender, age and occurrence of accompanying disease. The aim of this study is to assess the effectiveness of a three-week early CR in reference to changing body composition parameters in patients over 50 years of age. The study involved a random group of 65 patients (44 men and 21 women) between the ages of 50-76 (average: 62.6 ± 7.2) years with CHD following CABG. Anthropometric and body composition (bioelectrical impedance method) measurements were taken at the commencement of CR and after the training programme. After CR, body mass and body mass index were reduced in men < 65 and ≥ 65 years, and in women <65 years. A reduction % body fat and increase % fat free mass and % total body water was observed only in patients <65. years. Furthermore, in men < 65 years, an increase in % body cell mass was observed. In women ≥ 65 years, no statistically significant changes were observed in body fat indices and body composition features between initial and final study. Patients ≥ 65 years of age following surgery over a period of hospital cardiac rehabilitation do not experience the same significant improvement in body composition parameters associated with risk of CHD as middle-aged adults. Older women post-cardiac surgery are characterized by a higher disability index in relation to tolerance to physical stress in comparison with men of the same age and persons < 65 years of age.

  9. Collection and composition of autologous peripheral blood stem cells graft in patients with acute myeloid leukemia: influence on hematopoietic recovery and outcome.

    Science.gov (United States)

    Raos, Mirela; Nemet, Damir; Bojanić, Ines; Sertić, Dubravka; Batinić, Drago; Dusak, Vesna; Dubravcić, Klara; Mazić, Sanja; Serventi-Seiwerth, Ranka; Mrsić, Mirando; Golubić-Cepulić, Branka; Labar, Boris

    2010-03-01

    Hematopoietic stem cell (HSC) transplantation is a standard approach in the treatment of hematological malignant diseases. For the last 15 years the main source of cells for transplantation have been peripheral blood stem cells (PBSC). With the availability of hematopoietic growth factors and understanding the advantages of treatment with PBSC, the application of bone marrow (BM) was supplanted. The aim of this survey was to explore the success of PBSC collection, the factors which influence the success of PBSC collection, the composition and the quality of graft and their influence on hematopoietic recovery and outcome after transplantation in patients with acute myeloid leukemia (AML). PBSC were collected by the method of leukapheresis after applying a combination of chemotherapy and growth factors or only growth factors. The quality of graft was determined with the clonogenic progenitor cell assay and with the flow cytometry analysis. Of the total 134 patients with AML, who were submitted to HSC mobilization, the collection was successful in 78 (58.2%) patients. The collection was more successful after the first than after the second attempt of HSC mobilization (49% vs. 11%). The criteria for effective mobilization were the number of leukocytes > 3 x 10(9)/L and the concentration of CD34+ cells > 20 x 10(3)/mL in the peripheral blood on the first day of leukapheresis. The number of CD34+ cells infused had the strongest impact on hematopoietic recovery. We noted significantly faster hematological recovery of neutrophils and platelets, fewer number of transfused units of red blood cells and platelets, shorter duration of the tranfusion support, shorter treatment with intravenous antibiotic therapy and shorter hospitalization after PBSC compared to BM transplantation. These advantages could provide their standard application in the treatment of patients with AML.

  10. Self-Assembly of Polyethylene Glycol-Grafted Carbon Nanotube/Sulfur Composite with Nest-like Structure for High-Performance Lithium-Sulfur Batteries.

    Science.gov (United States)

    Li, Han; Sun, Liping; Wang, Gengchao

    2016-03-09

    The novel polyethylene glycol-grafted multiwalled carbon nanotube/sulfur (PEG-CNT/S) composite cathodes with nest-like structure are fabricated through a facile combination process of liquid phase deposition and self-assembly, which consist of the active material core of sulfur particle and the conductive shell of PEG-CNT network. The unique architecture not only provides a short and rapid charge transfer pathway to improve the reaction kinetics but also alleviates the volume expansion of sulfur during lithiation and minimizes the diffusion of intermediate polysulfides. Such an encouraging electrochemical environment ensures the excellent rate capability and high cycle stability. As a result, the as-prepared PEG-CNT/S composite with sulfur content of 75.9 wt % delivers an initial discharge capacity of 1191 and 897 mAh g(-1) after 200 cycles at 0.2 C with an average Coulombic efficiency of 99.5%. Even at a high rate of 2 C, an appreciable capacity of 723 mAh g(-1) can still be obtained.

  11. Composition of Air Pollutants in Selected Areas of Lagos, Nigeria ...

    African Journals Online (AJOL)

    The composition of air pollutants in Ojuelegba Motor Park, Oshodi Motor Park and Festac Town Residence was carried out within 24 hours each using an automated gas detector of Crowcon Gasman models 89/336/EEC (handheld) with operating temperature of between 200C to 500C. The results obtained showed ...

  12. Effect of Processing on the Elemental Composition of Selected Leafy ...

    African Journals Online (AJOL)

    The elemental composition of leaves of Vernonia amygdalina, Gnetum africana, Gongronema latifolium and Ocimum gratissimum subjected to different processing methods were investigated. Processing methods employed include oven drying, sun drying, fresh milling, steaming and a combination of these while the mineral ...

  13. Proximate and Cholesterol Composition of Selected Fast Foods ...

    African Journals Online (AJOL)

    Fast foods consumption has been on the increase in Nigeria raising concerns about the nutritional and health implications. This study was carried out to determine the proximate composition and cholesterol contents of four commonly consumed fast foods (doughnut, chicken pie, roasted chicken, and Jollof rice) sold in ...

  14. Selective response of dopamine in the presence of ascorbic acid and uric acid at gold nanoparticles and multi-walled carbon nanotubes grafted with ethylene diamine tetraacetic acid modified electrode

    Directory of Open Access Journals (Sweden)

    Yun-fei Long

    2009-12-01

    Full Text Available By grafting with ethylene diamine tetraacetic acid (EDTA, novel multi-walled carbon nanotube nano-composites (EDTA-MWCNTs have been successfully prepared. The integration of gold nanoparticles (AuNPs and novel functionalized matrix shows very promising applications in the fabrication of biosensors for sensitive detection of dopamine in the presence of ascorbic acid and uric acid with the combination of the charge repelling property of carboxylic anion and the electrocatalytic effect of EDTA. The AuNPs and EDTA-MWCNTs modified film shows excellent sensitivity and selectivity for the dopamine analysis due to the synergic effect of AuNPs and EDTA-MWCNTs. As high as 2000 fold and 150 fold acceptable tolerance of ascorbic acid and uric acid for the determination of trace dopamine is reached, respectively. The linear concentration range for dopamine is from 1.0 × 10-8 to 6.0 × 10-6 mol.L-1, and the detection limit is 3.0 × 10-9 mol.L-1. The response of the sensor is very quick and response time is less than 1 s. The method can be applied to detect the dopamine in human urine samples.

  15. Synthesis and characterization of chitosan-graft-poly(acrylic acid)/rice husk ash hydrogels composites; Sintese e caracterizacao de hidrogeis compositos de cinza da casca de arroz e quitosana enxertada com poli(acido acrilico)

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Francisco H.A. [Universidade Estadual Vale do Acarau - UVA, Sobral, CE (Brazil); Lopes, Gabriel V.; Pereira, Antonio G.B.; Fajardo, Andre R.; Muniz, Edvani C. [Universidade Estadual de Maringa - UEM, PR (Brazil)

    2011-07-01

    According to environmental concerns, super absorbent hydrogel composites were synthesized based on rice husk ash (RHA), an industrial waste, and Chitosan-graft-poly(acrylic acid). The WAXS and FTIR data confirmed the syntheses of hydrogel composites. The effect of crystalline or amorphous RHA on water uptake was investigated. It was found that the RHA in crystalline form induces higher water capacity (W{sub eq}) of composites hydrogels due to the fact that the intra-interactions among silanol groups on RHA make available new sites in the polymer matrix, which could interact to water. (author)

  16. Surgery of the aortic root: should we go for the valve-sparing root reconstruction or the composite graft-valve replacement is still the first choice of treatment for these patients?

    Directory of Open Access Journals (Sweden)

    Fernando de Azevedo Lamana

    2015-09-01

    Full Text Available AbstractObjective:To compare the results of the root reconstruction with the aortic valve-sparing operation versus composite graftvalve replacement.Methods:From January 2002 to October 2013, 324 patients underwent aortic root reconstruction. They were 263 composite graft-valve replacement and 61 aortic valve-sparing operation (43 reimplantation and 18 remodeling. Twenty-six percent of the patients were NYHA functional class III and IV; 9.6% had Marfan syndrome, and 12% had bicuspid aortic valve. There was a predominance of aneurysms over dissections (81% vs. 19%, with 7% being acute dissections. The complete follow-up of 100% of the patients was performed with median follow-up time of 902 days for patients undergoing composite graft-valve replacement and 1492 for those undergoing aortic valve-sparing operation.Results:In-hospital mortality was 6.7% and 4.9%, respectively for composite graft-valve replacement and aortic valve-sparing operation (ns. During the late follow-up period, there was 0% moderate and 15.4% severe aortic regurgitation, and NYHA functional class I and II were 89.4% and 94%, respectively for composite graft-valve replacement and aortic valve-sparing operation (ns. Root reconstruction with aortic valve-sparing operation showed lower late mortality (P=0.001 and lower bleeding complications (P=0.006. There was no difference for thromboembolism, endocarditis, and need of reoperation.Conclusion:The aortic root reconstruction with preservation of the valve should be the operation being performed for presenting lower late mortality and survival free of bleeding events.

  17. Cast net design characteristics, catch composition and selectivity in ...

    African Journals Online (AJOL)

    Cast net design characteristics, construction, operational techniques and selectivity in Lagos lagoon, Nigeria was examined between September and December 2005. Netting materials for cast net construction in Lagos lagoon were monofilament nylon, poly-ethylene (PE) and polyester (PES). The conventional ratio 1:2 of ...

  18. Proximate Compositions and physical properties of selected maize ...

    African Journals Online (AJOL)

    Physical properties such as germination capacity, hydration capacity, floater test and thousand-grain weight differed significantly (P≤ 0.05) among the selected varieties. The suitability of the maize grain varieties to processing and production of different maize based food products were highlighted. Key words: Maize ...

  19. Selective formation and efficient photocurrent generation of [70]fullerene-single-walled carbon nanotube composites

    NARCIS (Netherlands)

    Umeyama, Tomokazu; Tezuka, Noriyasu; Seki, Shu; Matano, Yoshihiro; Nishi, Masayuki; Hirao, Kazuyuki; Lehtivuori, Heli; Tkachenko, Nikolai V.; Lemmetyinen, Helge; Nakao, Yoshihide; Sakaki, Shigeyoshi; Imahori, Hiroshi

    2010-01-01

    For the first time nanocarbon composites with C 70 molecules aligned on the sidewall of single-walled carbon nanotubes (SWNTs) are demonstrated. The C70-SWNT photoelectrochemical devices exhibit efficient photocurrent generation properties that result from selective formation of a single composite

  20. Selective sorption of Fe(II) ions over Cu(II) and Cr(VI) ions by cross-linked graft copolymers of chitosan with acrylic acid and binary vinyl monomer mixtures.

    Science.gov (United States)

    Lalita; Singh, Anirudh P; Sharma, Rajeev Kr

    2017-12-01

    Low-cost and environment-friendly polymeric adsorbents for sorption of heavy metal ions were synthesized by simultaneous graft copolymerization and cross-linking of acrylic acid alone and with comonomers glycidyl methacrylate, acrylamide and acrylonitrile onto chitosan using free radical initiator and cross-linker in aqueous medium. Structural aspects of cross-linked graft copolymers have been characterized by FTIR, SEM, TGA/DTA, XRD and swelling behavior at pH 2.2, 7.0 and 9.4. An attempt has been made to study sorption of Cr(VI), Cu(II) and Fe(II) ions on cross-linked graft copolymers by equilibration method and to establish a relationship between structural aspects of graft copolymers and metal ion uptake efficiency and selectivity. Solutions of individual ions were used for non-competitive sorption onto synthesized bio-adsorbents as a function of change in contact time, temperature, pH and metal ion concentration in feed. Competitive sorption investigation was performed from an aqueous solution of ternary metal ions by batch equilibration at 25°C and at 7.0pH. Cross-linked graft copolymers showed better results than unmodified chitosan and showed preferential sorption of Fe(II) ions than Cu(II) and Cr(VI) ions. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Radiation Graft Copolymerization of Butyl methacrylate and Acrylamide onto Low density polyethylene and polypropylene films and its application in wastewater treatment

    International Nuclear Information System (INIS)

    Abdel Ghaffar, A.M.; El-Arnaouty, M.B.; Aboulfotouh, M.E.; Taher, N.H.

    2012-01-01

    Butyl methacrylate and Acrylamide (BMA/AAm) comonomer were grafted onto Low density polyethylene and polypropylene films using direct gamma radiation by grafting technique. The influences of grafting conditions such as solvent, monomer concentration, monomer composition, and irradiation dose on the grafting yield were determined. It was found that, using DMF as a solvent enhanced the copolymerization process. The grafting yield increases with comonomer concentration up to 60 %. . Also it was found that, the degree of grafting of (BMA/AAm) onto LDPE and PP films increases as the AAm content increases till optimum value at (50:50) %. The grafting yield of the comonomer found to be increased with increasing radiation dose. It was observed that the degree of grafting of polyethylene films is higher than that for polypropylene films. Some selected properties of the graft copolymers, such as water uptake and thermal properties determined by using thermogravimetric analysis (TGA) has been carried out. The morphology and structure of grafted films was investigated by using SEM, IR and X-ray diffraction. The improvement in such properties of the prepared copolymers was observed which makes possible uses in some practical applications such as in the removal of some heavy metals from wastewater. It was found that the maximum metal uptake by the copolymer is ordered in the sequence of Cu 2+ > CO 2+ > Ni 2+ ions.

  2. Bone grafting in surgery about the foot and ankle: indications and techniques.

    Science.gov (United States)

    Fitzgibbons, Timothy C; Hawks, Michael A; McMullen, Scott T; Inda, David J

    2011-02-01

    Bone grafting is a common procedure in foot and ankle surgery. Historically, autogenous bone graft has most often been harvested from the ipsilateral iliac crest. However, other sites offer similar volumes of cancellous bone and are associated with fewer complications. The ipsilateral proximal tibia, distal tibia, and calcaneus provide adequate amounts of bone graft material for most arthrodesis procedures about the foot and ankle. Emerging techniques have enabled the development of a seemingly unlimited supply of alternative bone graft materials with osteoconductive properties. The osteoprogenitor cells in bone marrow aspirates can be concentrated by use of selective retention systems. These aspirate-matrix composites may be combined with allograft preparations, resulting in a product that promotes osteoconduction, osteoinduction, and osteogenesis with limited morbidity.

  3. Dual-pH/Magnetic-Field-Controlled Drug Delivery Systems Based on Fe3O4@SiO2-Incorporated Salecan Graft Copolymer Composite Hydrogels.

    Science.gov (United States)

    Hu, Xinyu; Wang, Yongmei; Zhang, Liangliang; Xu, Man; Zhang, Jianfa; Dong, Wei

    2017-10-09

    Salecan is a water-soluble extracellular β-glucan and has excellent physicochemical and biological properties for hydrogel preparation. In this study, a new pH/magnetic field dual-responsive hydrogel was prepared by the graft copolymerization of salecan with 4-pentenoic acid (PA) and N-hydroxyethylacrylamide (HEAA) in the presence of Fe 3 O 4 @SiO 2 nanoparticles for doxorubicin hydrochloride (DOX) release. Integration of Fe 3 O 4 @SiO 2 nanoparticles in salecan-g-poly(PA-co-HEAA) copolymers afforded magnetic sensitivity to the original material. DOX-loaded hydrogels exhibited a clear capacity for pH/magnetic field dual-responsive controlled drug release. Lowering the pH to acidic conditions or introducing an external magnetic field caused an enhancement in DOX release. This salecan-g-poly(PA-co-HEAA)/Fe 3 O 4 @SiO 2 composite hydrogel is a promising drug carrier for magnetically targeted drug delivery with enhanced DOX cytotoxicity against A549 cells. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Plasma Polymerization of SnOxCy Organic-Like Films and Grafted PNIPAAm Composite Hydrogel with Nanogold Particles for Promotion of Thermal Resistive Properties

    Directory of Open Access Journals (Sweden)

    Chin-Yen Chou

    2016-12-01

    Full Text Available In this study, a new type of temperature sensor device was developed. The circular electrode of the thermally sensitive sensor was modified with tetramethyltin (TMT and O2 plasma to form a thin SnOxCy conductive layer on the electrode surface. The nano-Au particles (AuNPs were subjected to O2 plasma pretreatment to form peroxide groups on the surface. The thermally sensitive sensor made by mixing the treated AuNPs with N-isopropylacrylamide (NIPAAm solution and then applying UV-induced grafting polymerization of the NIPAAm-containing solution onto the electrode substrate. The composite hydrogels on the electrode introduce thermo-sensitive polymeric surface films for temperature sensing. Using the ambient environment resistance test to measure the resistance, the lower critical solution temperature (LCST of AuNPs mixed with NIPAAm hydrogel was found to be 32 °C. In common metallic materials, the resistance increased during environmental temperature enhancement. In this study, at ambient temperatures higher than the LCST, the electrode resistance decreases linearly due to the shrinkage structure with AuNPs contacting the circuit electrode.

  5. Enhancement of the Mechanical Properties of Basalt Fiber-Wood-Plastic Composites via Maleic Anhydride Grafted High-Density Polyethylene (MAPE) Addition.

    Science.gov (United States)

    Chen, Jinxiang; Wang, Yong; Gu, Chenglong; Liu, Jianxun; Liu, Yufu; Li, Min; Lu, Yun

    2013-06-18

    This study investigated the mechanisms, using microscopy and strength testing approaches, by which the addition of maleic anhydride grafted high-density polyethylene (MAPE) enhances the mechanical properties of basalt fiber-wood-plastic composites (BF-WPCs). The maximum values of the specific tensile and flexural strengths are achieved at a MAPE content of 5%-8%. The elongation increases rapidly at first and then continues slowly. The nearly complete integration of the wood fiber with the high-density polyethylene upon MAPE addition to WPC is examined, and two models of interfacial behavior are proposed. We examined the physical significance of both interfacial models and their ability to accurately describe the effects of MAPE addition. The mechanism of formation of the Model I interface and the integrated matrix is outlined based on the chemical reactions that may occur between the various components as a result of hydrogen bond formation or based on the principle of compatibility, resulting from similar polarity. The Model I fracture occurred on the outer surface of the interfacial layer, visually demonstrating the compatibilization effect of MAPE addition.

  6. Enhancement of the Mechanical Properties of Basalt Fiber-Wood-Plastic Composites via Maleic Anhydride Grafted High-Density Polyethylene (MAPE Addition

    Directory of Open Access Journals (Sweden)

    Yun Lu

    2013-06-01

    Full Text Available This study investigated the mechanisms, using microscopy and strength testing approaches, by which the addition of maleic anhydride grafted high-density polyethylene (MAPE enhances the mechanical properties of basalt fiber-wood-plastic composites (BF-WPCs. The maximum values of the specific tensile and flexural strengths are achieved at a MAPE content of 5%–8%. The elongation increases rapidly at first and then continues slowly. The nearly complete integration of the wood fiber with the high-density polyethylene upon MAPE addition to WPC is examined, and two models of interfacial behavior are proposed. We examined the physical significance of both interfacial models and their ability to accurately describe the effects of MAPE addition. The mechanism of formation of the Model I interface and the integrated matrix is outlined based on the chemical reactions that may occur between the various components as a result of hydrogen bond formation or based on the principle of compatibility, resulting from similar polarity. The Model I fracture occurred on the outer surface of the interfacial layer, visually demonstrating the compatibilization effect of MAPE addition.

  7. Stent graft placement for dysfunctional arteriovenous grafts

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Gyeong Sik [Dept. of Radiology, CHA Bundang Medical Center, College of Medicine, CHA University, Seongnam (Korea, Republic of); Shin, Byung Seok; Ohm, Joon Young; Ahn, Moon Sang [Chungnam National University Hospital, Daejeon (Korea, Republic of)

    2015-07-15

    This study aimed to evaluate the usefulness and outcomes of stent graft use in dysfunctional arteriovenous grafts. Eleven patients who underwent stent graft placement for a dysfunctional hemodialysis graft were included in this retrospective study. Expanded polytetrafluoroethylene covered stent grafts were placed at the venous anastomosis site in case of pseudoaneurysm, venous laceration, elastic recoil or residual restenosis despite the repeated angioplasty. The patency of the arteriovenous graft was evaluated using Kaplan-Meier analysis. Primary and secondary mean patency was 363 days and 741 days. Primary patency at 3, 6, and 12 months was 82%, 73%, and 32%, respectively. Secondary patency at the 3, 6, 12, 24, and 36 months was improved to 91%, 82%, 82%, 50%, and 25%, respectively. Fractures of the stent graft were observed in 2 patients, but had no effect on the patency. Stent graft placement in dysfunctional arteriovenous graft is useful and effective in prolonging graft patency.

  8. Beta-galactosidase and selective neutrality. [amino acid composition of proteins

    Science.gov (United States)

    Holmquist, R.

    1979-01-01

    Three hypotheses to explain the amino acid composition of proteins are inconsistent (about 10 to the minus 9th) with the experimental data for beta-galactosidase from Escherichia coli. The exceptional length of this protein, 1021 residues, permits rigorous tests of these hypotheses without complication from statistical artifacts. Either this protein is not at compositional equilibrium, which is unlikely from knowledge about other proteins, or the evolution of this protein and its coding gene have not been selectively neutral. However, the composition of approximately 60% of the molecule is consistent with either a selectively neutral or nonneutral evolutionary process.

  9. Selective removal of dental composite using a rapidly scanned carbon dioxide laser

    Science.gov (United States)

    Chan, Kenneth H.; Fried, Daniel

    2011-03-01

    Dental restorative materials are color matched to the tooth and are difficult to remove by mechanical means without excessive removal or damage to peripheral enamel and dentin. Lasers are ideally suited for selective ablation to minimize healthy tissue loss when replacing existing restorations, sealants or removing composite adhesives such as residual composite left after debonding orthodontic brackets. In this study a carbon dioxide laser operating at high laser pulse repetition rates integrated with a galvanometer based scanner was used to selectively remove composite from tooth surfaces. A diode array spectrometer was used to measure the plume emission after each laser pulse and determine if the ablated material was tooth mineral or composite. The composite was placed on tooth buccal and occlusal surfaces and the carbon dioxide laser was scanned across the surface to selectively remove the composite without excessive damage to the underlying sound enamel. The residual composite and the damage to the underlying enamel was evaluated using optical microscopy. The laser was able to rapidly remove the composites rapidly from both surfaces with minimal damage to the underlying sound enamel.

  10. Mutational analysis of affinity and selectivity of kringle-tetranectin interaction. Grafting novel kringle affinity ontp the trtranectin lectin scaffold

    DEFF Research Database (Denmark)

    Graversen, Jonas Heilskov; Jacobsen, C; Sigurskjold, B W

    2000-01-01

    C-type lectin-like domains are found in many proteins, where they mediate binding to a wide diversity of compounds, including carbohydrates, lipids, and proteins. The binding of a C-type lectin-like domain to a ligand is often influenced by calcium. Recently, we have identified a site in the C-ty....... This study provides further insight into molecular determinants of importance for binding selectivity and affinity of C-type lectin kringle interactions....

  11. CO2-selective PEO–PBT (PolyActive™)/graphene oxide composite membranes

    KAUST Repository

    Karunakaran, Madhavan

    2015-07-31

    CO2-selective graphene oxide (GO) nano-composite membranes were prepared for the first time by embedding GO into a commercially available poly(ethylene oxide)–poly(butylene terephthalate) (PEO–PBT) copolymer (PolyActive™). The as-prepared GO membrane shows high CO2 permeability (143 Barrer) and CO2/N2 selectivity (α = 73).

  12. Selecting the Best Materials Compositions of Resin Based Bioasphalt

    Science.gov (United States)

    Setyawan, Ary; Widiharjo, Budi; Djumari

    2017-07-01

    Damar asphalt is one type of bioaspal which is a mixture with the main ingredient is a resin as a binder and cooking oil as a solvent. One major drawback of this damar asphalt is the low ductility. To improve the ductility values, then use the added material Filler. Filler serves as a divider between the impurities with damar asphalt, increases ductility and increase the ability of cohesion or bonding between the particles of material damar asphalt. The purpose of this study was to determine damar asphalt modifications to the properties in accordance with the properties of damar asphalt test specifications based on the value of penetration. This method uses some variant on material such as powder bricks and fly ash as a binder. Solvent in constituent used oil and used cooking oil. It also added the polymer latex up to 10% at intervals of 2%. The best composition of damar asphalt materials were obtained with gum rosin, Fly Ash, Oil and Latex. Damar asphalt modification damar asphalt optimum mix of resin (100g pure resin or resin chunk + 350g powder), Fly Ash powder (150g), cooking oil (205g), and latex 4%, ductility increased from 63.5 cm to 119.5 cm, the value of the flash point was originally at temperature of 240 °C to 260 °C, damar asphalt penetration of 68.2 dmm to 43 dmm, and the value of density decreases from 1.01 g / cm3 to 0.99 g / cm3. Damar asphalt at these modifications meet the specifications in terms of solubility in trichlore ethylene is equal to 99.5%, and also meet the affinity of damar asphalt at 99%. With the optimum value, damar asphalt could be categorized as bitumen 40/60 penetration.

  13. Selective removal of esthetic composite restorations with spectral guided laser ablation

    Science.gov (United States)

    Yi, Ivana; Chan, Kenneth H.; Tsuji, Grant H.; Staninec, Michal; Darling, Cynthia L.; Fried, Daniel

    2016-02-01

    Dental composites are used for a wide range of applications such as fillings for cavities, adhesives for orthodontic brackets, and closure of gaps (diastemas) between teeth by esthetic bonding. Anterior restorations are used to replace missing, diseased and unsightly tooth structure for both appearance and function. When these restorations must be replaced, they are difficult to remove mechanically without causing excessive removal or damage to enamel because dental composites are color matched to teeth. Previous studies have shown that CO2 lasers have high ablation selectivity and are well suited for removal of composite on occlusal surfaces while minimizing healthy tissue loss. A spectral feedback guidance system may be used to discriminate between dental composite and dental hard tissue for selective ablation of composite material. The removal of composite restorations filling diastemas is more challenging due to the esthetic concern for anterior teeth. The objective of this study is to determine if composite spanning a diastema between anterior teeth can be removed by spectral guided laser ablation at clinically relevant rates with minimal damage to peripheral healthy tissue and with higher selectivity than a high speed dental handpiece.

  14. An Antigen-Presenting and Apoptosis-Inducing Polymer Microparticle Prolongs Alloskin Graft Survival by Selectively and Markedly Depleting Alloreactive CD8+ T Cells

    Directory of Open Access Journals (Sweden)

    Wei Wang

    2017-06-01

    Full Text Available Selectively depleting the pathogenic T cells is a fundamental strategy for the treatment of allograft rejection and autoimmune disease since it retains the overall immune function of host. The concept of killer artificial antigen-presenting cells (KaAPCs has been developed by co-coupling peptide–major histocompatibility complex (pMHC multimer and anti-Fas monoclonal antibody (mAb onto the polymeric microparticles (MPs to induce the apoptosis of antigen-specific T cells. But little information is available about its in vivo therapeutic potential and mechanism. In this study, polyethylenimine (PEI-coated poly lactic-co-glycolic acid microparticle (PLGA MP was fabricated as a cell-sized scaffold to covalently co-couple H-2Kb-Ig dimer and anti-Fas mAb for the generation of alloantigen-presenting and apoptosis-inducing MPs. Intravenous infusions of the biodegradable KaAPCs prolonged the alloskin graft survival for 43 days in a single MHC-mismatched murine model, depleted the most of H-2Kb-alloreactive CD8+ T cells in peripheral blood, spleen, and alloskin graft in an antigen-specific manner and anti-Fas-dependent fashion. The cell-sized KaAPCs circulated throughout vasculature into liver, kidney, spleen, lymph nodes, lung, and heart, but few ones into local allograft at early stage, with a retention time up to 36 h in vivo. They colocalized with CD8+ T cells in secondary lymphoid organs while few ones contacted with CD4+ T cells, B cells, macrophage, and dendritic cells, or internalized by phagocytes. Importantly, the KaAPC treatment did not significantly impair the native T cell repertoire or non-pathogenic immune cells, did not obviously suppress the overall immune function of host, and did not lead to visible organ toxicity. Our results strongly document the high potential of PLGA MP-based KaAPCs as a novel antigen-specific immunotherapy for allograft rejection and autoimmune disorder. The in vivo mechanism of alloinhibition, tissue

  15. Selective Dispersive Solid Phase Extraction of Ser-traline Using Surface Molecularly Imprinted Polymer Grafted on SiO2/Graphene Oxide

    Directory of Open Access Journals (Sweden)

    Faezeh Khalilian

    2017-01-01

    Full Text Available A surface molecularly imprinted dispersive solid phase extraction coupled with liquid chromatography–ultraviolet detection is proposed as a selective and fast clean-up technique for the determination of sertraline in biological sample. Surface sertraline-molecular imprinted polymer was grafted and synthesized on the SiO2/graphene oxide surface. Firstly SiO2 was coated on synthesized graphene oxide sheet using sol-gel technique. Prior to polymerization, the vinyl group was incorporated on to the surface of SiO2/graphene oxide to direct selective polymerization on the surface. Methacrylic acid, ethylene glycol dimethacrylate and ethanol were used as monomer, cross-linker and progen, respectively. Non-imprinted polymer was also prepared for comparing purposes. The properties of the molecular imprinted polymer were characterized using field emission-scanning electron microscopy and Fourier transform infrared spectroscopy methods. The surface molecular imprinted polymer was utilized as an adsorbent of dispersive solid phase extraction for separation and preconcentration of sertraline. The effects of the different parameters influencing the extraction efficiency, such as sample pH were investigated and optimized. The specificity of the molecular imprinted polymer over the non-imprinted polymer was examined in absence and presence of competitive drugs. Sertraline calibration curve showed linearity in the ranges 1–500 µg L-1. The limits of detection and quantification under optimized conditions were obtained 0.2 and 0.5 µg L-1. The within-day and between-day relative standard deviations (n=3 were 4.3 and 7.1%, respectively. Furthermore, the relative recoveries for spiked biological samples were above 92%.

  16. High-Dose Sirolimus and Immune-Selective Pentostatin plus Cyclophosphamide Conditioning Yields Stable Mixed Chimerism and Insufficient Graft-versus-Tumor Responses.

    Science.gov (United States)

    Mossoba, Miriam E; Halverson, David C; Kurlander, Roger; Schuver, Bazetta Blacklock; Carpenter, Ashley; Hansen, Brenna; Steinberg, Seth M; Ali, Syed Abbas; Tageja, Nishant; Hakim, Frances T; Gea-Banacloche, Juan; Sportes, Claude; Hardy, Nancy M; Hickstein, Dennis D; Pavletic, Steven Z; Khuu, Hanh; Sabatini, Marianna; Stroncek, David; Levine, Bruce L; June, Carl H; Mariotti, Jacopo; Rixe, Olivier; Fojo, Antonio Tito; Bishop, Michael R; Gress, Ronald E; Fowler, Daniel H

    2015-10-01

    We hypothesized that lymphoid-selective host conditioning and subsequent adoptive transfer of sirolimus-resistant allogeneic T cells (T-Rapa), when combined with high-dose sirolimus drug therapy in vivo, would safely achieve antitumor effects while avoiding GVHD. Patients (n = 10) with metastatic renal cell carcinoma (RCC) were accrued because this disease is relatively refractory to high-dose conditioning yet may respond to high-dose sirolimus. A 21-day outpatient regimen of weekly pentostatin (P; 4 mg/m(2)/dose) combined with daily, dose-adjusted cyclophosphamide (C; ≤200 mg/d) was designed to deplete and suppress host T cells. After PC conditioning, patients received matched sibling, T-cell-replete peripheral blood stem cell allografts, and high-dose sirolimus (serum trough target, 20-30 ng/mL). To augment graft-versus-tumor (GVT) effects, multiple T-Rapa donor lymphocyte infusions (DLI) were administered (days 0, 14, and 45 posttransplant), and sirolimus was discontinued early (day 60 posttransplant). PC conditioning depleted host T cells without neutropenia or infection and facilitated donor engraftment (10 of 10 cases). High-dose sirolimus therapy inhibited multiple T-Rapa DLI, as evidenced by stable mixed donor/host chimerism. No antitumor responses were detected by RECIST criteria and no significant classical acute GVHD was observed. Immune-selective PC conditioning represents a new approach to safely achieve alloengraftment without neutropenia. However, allogeneic T cells generated ex vivo in sirolimus are not resistant to the tolerance-inducing effects of in vivo sirolimus drug therapy, thereby cautioning against use of this intervention in patients with refractory cancer. ©2015 American Association for Cancer Research.

  17. Emotional processes in patients undergoing coronary artery bypass graft surgeries with extracorporeal circulation in view of selected indicators of the inflammatory condition.

    Science.gov (United States)

    Płotek, Włodzimierz; Pielok, Joanna; Cybulski, Marcin; Samborska, Regina

    2015-01-09

    The aim of this study was to describe positive and negative emotions in patients undergoing coronary artery bypass graft (CABG) surgeries with extracorporeal circulation and the correlations between emotions and basic indicators of the inflammatory condition: C-reactive protein (CRP) concentration, body temperature, and leukocyte count. Standardized tools were used to select 52 patients (aged 47-63 years, 6 women--11.5% and 46 men--88.5%) without dementia or depression. The Positive and Negative Affect Schedule (PANAS) was used to examine positive affect (PA) and negative affect (NA) and the State-Trait Anxiety Inventory (STAI X1 and X2) was used to examine the anxiety level. The patients underwent CABG surgery according to a common anesthesia protocol and for 5 consecutive days they were observed in the ward, where selected indicators of the inflammatory condition were monitored. A detailed description of the results of examinations of emotions was presented. The patients with low PA-trait level, high NA-trait level, and high anxiety-trait level (STAI X2) exhibited statistically significantly higher body temperatures than the other patients in the postoperative period. The patients with high NA-trait and anxiety-state levels (STAI X1) had statistically significantly lower CRP levels in the postoperative period than the patients with low NA-trait and anxiety-state levels (STAI X1). Patients undergoing CABG operations express both positive and negative affects. The changes in the inflammatory markers are expressed mostly by CRP concentration. There exist relationships between the result of tests assessing emotions and the markers of the inflammatory condition.

  18. Costal Grafting in Mandibular Reconstruction.

    Science.gov (United States)

    Bachelet, Jean-Thomas; Bourlet, Jerôme; Château, Joseph; Jacquemart, Mathieu; Dufour, Clémence; Mojallal, Ali; Gleizal, Arnaud

    2015-11-01

    Reconstruction of mandibular bone defect is a common indication in craniomaxillofacial surgery, and free fibular flap is the gold standard for this indication. However, there are alternatives; nonvascular bone grafting is one of them, and we present the costal grafting for mandibular reconstruction, a classic technique that is reliable, efficient, and produced less morbidity than the technique of using composite free flaps. A 9-year retrospective review of 54 patients treated surgically for mandibular reconstruction was performed. The criterion mainly analyzed was graft survival. The surgical technique was described in detail. A total of 54 patients with mandibular bone defect were identified. Five symphysis, 46 corpus, and 20 ramus defects were considered. These patients underwent reconstruction by costal grafting, and the engrafting was successful in 92.6% of cases. Dental rehabilitation with dental implants was realized in 70% of cases. The approach described in this article allowed the authors to obtain good results with costal grafting for mandibular reconstruction and dental rehabilitation. Costal grafting is a good alternative for fibula free flap in specific indications. Reconstruction of mandibular bone defect is a common indication in craniomaxillofacial surgery. Since the 1980s, the gold standard for these defects is the use of free fibular flap.(1) In some cases, this technique is contradicted; the surgeon then has several possibilities for the use of free osteomyocutaneous flaps (iliac crest, scapula, and serrato-costal flaps).(2-8).

  19. Analytical Hierarchy Process for Natural Fiber Composites Automotive Armrest Thermoset Matrix Selection

    Directory of Open Access Journals (Sweden)

    Rosli M.U

    2017-01-01

    Full Text Available The automotive industry is currently shifting to a ‘green’ outlook since that the popularity of natural fibers in composites plastics is accelerating in many areas and particularly the automotive industry. Nowadays, consumers are looking for vehicles more environmentally friendly and lighter in weight. For this reason, the engineers are now focusing to substitute the metal parts on utilizing the natural fiber composites. Selecting the right material in product development is a crucial decision. Imprecise decision can cause the product to be remanufactured and not in optimized condition. One of the methods that can be employed is Analytical Hierarchy Process (AHP. This paper illustrates the implementation of AHP method in order to select the most appropriate thermoset matrix for natural fiber composites automotive armrest. The selection is based on the weight reduction as the major aim of the study.

  20. Analytical Hierarchy Process for Natural Fiber Composites Automotive Armrest Thermoset Matrix Selection

    OpenAIRE

    Rosli M.U; Jamalludin Mohd Riduan; Khor C.Y.; Ishak Muhammad Ikman; Jahidi H.; Yeop Wasir Norsyahadah; Faizal Wan Mohd; Wan Draman Wan Nur A’tiqah; Lailina NM; Ismail Ras Izzati

    2017-01-01

    The automotive industry is currently shifting to a ‘green’ outlook since that the popularity of natural fibers in composites plastics is accelerating in many areas and particularly the automotive industry. Nowadays, consumers are looking for vehicles more environmentally friendly and lighter in weight. For this reason, the engineers are now focusing to substitute the metal parts on utilizing the natural fiber composites. Selecting the right material in product development is a crucial decisio...

  1. Radiation grafting on natural films

    International Nuclear Information System (INIS)

    Lacroix, M.; Khan, R.; Senna, M.; Sharmin, N.; Salmieri, S.; Safrany, A.

    2014-01-01

    Different methods of polymer grafting using gamma irradiation are reported in the present study for the preparation of newly functionalized biodegradable films, and some important properties related to their mechanical and barrier properties are described. Biodegradable films composed of zein and poly(vinyl alcohol) (PVA) were gamma-irradiated in presence of different ratios of acrylic acid (AAc) monomer for compatibilization purpose. Resulting grafted films (zein/PVA-g-AAc) had their puncture strength (PS=37–40 N mm −1 ) and puncture deformation (PD=6.5–9.8 mm) improved for 30% and 50% PVA in blend, with 5% AAc under 20 kGy. Methylcellulose (MC)-based films were irradiated in the presence of 2-hydroxyethyl methacrylate (HEMA) or silane, in order to determine the effect of monomer grafting on the mechanical properties of films. It was found that grafted films (MC-g-HEMA and MC-g-silane) using 35% monomer performed higher mechanical properties with PS values of 282–296 N mm −1 and PD of 5.0–5.5 mm under 10 kGy. Compatibilized polycaprolactone (PCL)/chitosan composites were developed via grafting silane in chitosan films. Resulting trilayer grafted composite film (PCL/chitosan-g-silane/PCL) presented superior tensile strength (TS=22 MPa) via possible improvement of interfacial adhesion (PCL/chitosan) when using 25% silane under 10 kGy. Finally, MC-based films containing crystalline nanocellulose (CNC) as a filling agent were prepared and irradiated in presence of trimethylolpropane trimethacrylate (TMPTMA) as a grafted plasticizer. Grafted films (MC-g-TMPTMA) presented superior mechanical properties with a TS of 47.9 MPa and a tensile modulus (TM) of 1792 MPa, possibly due to high yield formation of radicals to promote TMPTMA grafting during irradiation. The addition of CNC led to an additional improvement of the barrier properties, with a significant 25% reduction of water vapor permeability (WVP) of grafted films. - Highlights: • Irradiation of zein

  2. Selective removal of dental composite with a diode-pumped Er:YAG laser

    Science.gov (United States)

    Fried, William A.; Chan, Kenneth H.; Darling, Cynthia L.; Fried, Daniel

    2016-02-01

    Selective removal of dental composite with high precision is best accomplished using lasers operating at high pulse repetition rates focused to a small spot size. Conventional flash-lamp pumped Er:YAG lasers are poorly suited for this purpose, but new diode-pumped Er:YAG lasers have become available operating at high pulse repetition rates. The purpose of this study was to compare the ablation rates and selectivity of enamel and composite for a 30 W diode-pumped Er:YAG laser operating with a pulse duration of 30-50-μs and evaluate it's suitability for the selective removal of composite from tooth surfaces. The depth of ablation and changes in surface morphology were assessed using digital microscopy. The fluence range of 30-50 J/cm2 appeared optimal for the removal of composite, and damage to sound enamel was limited to less than 100-μm after the removal of composite as thick as 700-800-μm. Future studies will focus on the use of methods of feedback to further increase selectivity.

  3. Selective Removal of Residual Orthodontic Composite Using a Rapidly Scanned Carbon Dioxide Laser with Spectral Feedback

    Science.gov (United States)

    Hirasuna, Krista

    Background and Objective: Excessive heat accumulation within the tooth, incomplete removal of composite, and variable damage to the enamel are shortcomings of using conventional burs to remove residual orthodontic composite after debonding fixed appliances. The objective of this study was to determine if composite could be selectively removed from the enamel surface using a rapidly scanned carbon dioxide laser controlled by spectral feedback. Materials and Methods: A carbon dioxide laser operating at a wavelength of 9.3 microm with a pulse duration of 10-15 micros and a pulse repetition rate of ˜ 200 Hz was used to selectively remove composite from the buccal surfaces of 21 extracted teeth. GrenGloo(TM) composite was used to better visualize residual composite and the amount of enamel lost was measured with optical microscopy. A spectral feedback system utilizing a miniature spectrometer was used to control the laser scanning system. Pulpal temperature measurements were performed during composite removal to determine if there was excessive heat accumulation. Results: The amount of enamel lost averaged 22.7microm +/- 8.9 and 25.3 microm +/- 9.4 for removal at 3.8 and 4.2 J/cm2, respectively. An average maximum temperature rise of 1.9°C +/- 1.5 was recorded, with no teeth approaching the critical value of 5.5°C. The average time of composite removal was 19.3 +/- 4.1 seconds. Conclusions: Residual orthodontic composite can be rapidly removed from the tooth surface using a rapidly scanned CO2 laser with spectral feedback, with minimal temperature rise within the pulp and with minimal damage to the underlying enamel surface.

  4. Method for selection of optimal road safety composite index with examples from DEA and TOPSIS method.

    Science.gov (United States)

    Rosić, Miroslav; Pešić, Dalibor; Kukić, Dragoslav; Antić, Boris; Božović, Milan

    2017-01-01

    Concept of composite road safety index is a popular and relatively new concept among road safety experts around the world. As there is a constant need for comparison among different units (countries, municipalities, roads, etc.) there is need to choose an adequate method which will make comparison fair to all compared units. Usually comparisons using one specific indicator (parameter which describes safety or unsafety) can end up with totally different ranking of compared units which is quite complicated for decision maker to determine "real best performers". Need for composite road safety index is becoming dominant since road safety presents a complex system where more and more indicators are constantly being developed to describe it. Among wide variety of models and developed composite indexes, a decision maker can come to even bigger dilemma than choosing one adequate risk measure. As DEA and TOPSIS are well-known mathematical models and have recently been increasingly used for risk evaluation in road safety, we used efficiencies (composite indexes) obtained by different models, based on DEA and TOPSIS, to present PROMETHEE-RS model for selection of optimal method for composite index. Method for selection of optimal composite index is based on three parameters (average correlation, average rank variation and average cluster variation) inserted into a PROMETHEE MCDM method in order to choose the optimal one. The model is tested by comparing 27 police departments in Serbia. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. The Relationship between Selected Body Composition Variables and Muscular Endurance in Women

    Science.gov (United States)

    Esco, Michael R.; Olson, Michele S.; Williford, Henry N.

    2010-01-01

    The primary purpose of this study was to determine if muscular endurance is affected by referenced waist circumference groupings, independent of body mass and subcutaneous abdominal fat, in women. This study also explored whether selected body composition measures were associated with muscular endurance. Eighty-four women were measured for height,…

  6. Optimisation of optical absorption properties of spectrally selective C-NiO composite coatings

    CSIR Research Space (South Africa)

    Tile, N

    2011-05-01

    Full Text Available and expensive. Carbon in Nickel Oxide (C-NiO) composite material has been found to have a very good spectral selectivity1,2. Moreover this material has a potential of low cost large scale fabrication since it can be fabricated by a simple sol-gel technique...

  7. 37 CFR 251.6 - Composition and selection of Copyright Arbitration Royalty Panels.

    Science.gov (United States)

    2010-07-01

    ... Copyright Arbitration Royalty Panels. 251.6 Section 251.6 Patents, Trademarks, and Copyrights COPYRIGHT OFFICE, LIBRARY OF CONGRESS COPYRIGHT ARBITRATION ROYALTY PANEL RULES AND PROCEDURES COPYRIGHT ARBITRATION ROYALTY PANEL RULES OF PROCEDURE Organization § 251.6 Composition and selection of Copyright...

  8. Generalizability of a composite student selection procedure at a university-based chiropractic program

    DEFF Research Database (Denmark)

    O'Neill, Lotte Dyhrberg; Korsholm, Lars; Wallstedt, Birgitta

    2009-01-01

    PURPOSE: Non-cognitive admission criteria are typically used in chiropractic student selection to supplement grades. The reliability of non-cognitive student admission criteria in chiropractic education has not previously been examined. In addition, very few studies have examined the overall test...... generalizability of composites of non-cognitive admission variables in admission to health science programs. The aim of this study was to estimate the generalizability of a composite selection to a chiropractic program, consisting of: application form information, a written motivational essay, a common knowledge...... generalizability was found for the common knowledge test (G=1.00) and the admission interview (G=0.88). Good generalizability was found for application form information (G=0.75) and moderate generalizability (G=0.50) for the written motivation essay. The generalizability of the final composite admission procedure...

  9. Selectively gas-permeable composite membrane and process for production thereof

    International Nuclear Information System (INIS)

    Okita, K.; Asako, S.

    1984-01-01

    A selectively gas-permeable composite membrane and a process for producing said composite membrane are described. The composite membrane comprises a polymeric material support and a thin membrane deposited on the support, said thin membrane being obtained by glow discharge plasma polymerization of an organosilane compound containing at least one double bond or triple bond. Alternatively, the composite membrane comprises a polymeric material support having an average pore diameter of at least 0.1 micron, a hardened or cross-linked polyorganosiloxane layer on the support, and a thin membrane on the polyorganosiloxane layer, said thin membrane being obtained by plasma polymerization due to glow discharge of an organosilane compound containing at least one double bond or triple bond

  10. Synthesis of hydrophilic carbon nanotubes by grafting poly(methyl methacrylate) via click reaction and its effect on poly(vinylidene fluoride)-carbon nanotube composite membrane properties1

    Science.gov (United States)

    Ma, Wenzhong; Zhao, Yuchen; Li, Yuxue; Zhang, Peng; Cao, Zheng; Yang, Haicun; Liu, Chunlin; Tao, Guoliang; Gong, Fanghong; Matsuyama, Hideto

    2018-03-01

    Surface modification of azide-decorated multiwalled carbon nanotubes (MWCNTs) with well-defined alkyne-terminated poly(methyl methacrylate) (PMMA) chains was accomplished via the combination of reversible addition fragmentation chain transfer (RAFT) and "click" chemistry. Successful attachment of PMMA onto MWCNT was confirmed by Fourier transform infrared spectroscopy, thermogravimetric analysis (TGA), gel permeation chromatography, Raman spectroscopy, and transmission electron microscopy. The highest grafting percentage (GP) of the PMMA chains (GP = 23.3%) was calculated using TGA. The effect of the PMMA-grafted-MWCNTs (MWCNTs-g-PMMA) content on the performance of the poly(vinylidene fluoride) (PVDF)-MWCNTs-g-PMMA composite membrane was studied. The MWCNTs-g-PMMA was found to be well dispersed in the PVDF composite membrane matrix because of the excellent compatibility between the PMMA and PVDF chains. The composite membranes showed improved porosity, hydrophilicity, water flux, β-PVDF content, and mechanical properties at an optimal amount of 2 wt% MWCNTs-g-PMMA incorporated in the PVDF membrane matrix. In contrast, the hydroxyl functionalized MWCNTs (MWCNTs-OH) showed limited enhancement in the water flux and mechanical strength, which is mainly due to the poor dispersion of MWCNT because of the weak interaction between the MWCNT and PVDF chains. This study reveals the excellent prospect of the MWCNT-based ultrafiltration membrane with enhanced properties in water treatment applications.

  11. Quantitative analysis of mutation and selection pressures on base composition skews in bacterial chromosomes

    Directory of Open Access Journals (Sweden)

    Chen Carton W

    2007-08-01

    Full Text Available Abstract Background Most bacterial chromosomes exhibit asymmetry of base composition with respect to leading vs. lagging strands (GC and AT skews. These skews reflect mainly those in protein coding sequences, which are driven by asymmetric mutation pressures during replication and transcription (notably asymmetric cytosine deamination plus subsequent selection for preferred structures, signals, amino acid or codons. The transcription-associated effects but not the replication-associated effects contribute to the overall skews through the uneven distribution of the coding sequences on the leading and lagging strands. Results Analysis of 185 representative bacterial chromosomes showed diverse and characteristic patterns of skews among different clades. The base composition skews in the coding sequences were used to derive quantitatively the effect of replication-driven mutation plus subsequent selection ('replication-associated pressure', RAP, and the effect of transcription-driven mutation plus subsequent selection at translation level ('transcription-associate pressure', TAP. While different clades exhibit distinct patterns of RAP and TAP, RAP is absent or nearly absent in some bacteria, but TAP is present in all. The selection pressure at the translation level is evident in all bacteria based on the analysis of the skews at the three codon positions. Contribution of asymmetric cytosine deamination was found to be weak to TAP in most phyla, and strong to RAP in all the Proteobacteria but weak in most of the Firmicutes. This possibly reflects the differences in their chromosomal replication machineries. A strong negative correlation between TAP and G+C content and between TAP and chromosomal size were also revealed. Conclusion The study reveals the diverse mutation and selection forces associated with replication and transcription in various groups of bacteria that shape the distinct patterns of base composition skews in the chromosomes during

  12. Cambial Isoperoxidases Related to Graft Compatibility in Pear-Quince Graft Combinations

    OpenAIRE

    GÜLEN*, Hatice; ÇELİK, Menşure; POLAT, Mehmet; ERİŞ, Atilla

    2014-01-01

    This study was initiated to survey the graft compatibility characteristics of some selected quince clones known as "S.Ö." with regard to isoperoxidase markers. Compatible (Beurre Hardy = BH) and incompatible (Bartlett = BT) pear cultivars were grafted on quince A (QA) and 13 S.Ö. quince clones by T budding. Bark tissues were collected from the union (4, 8 and 12 weeks after grafting) and from unbudded rootstocks in addition to current-year shoots of 2 pear scions to investig...

  13. Perivenous support reduces early changes in human vein grafts : Studies in whole blood perfused human vein segments

    NARCIS (Netherlands)

    Stooker, W; Niessen, HWM; Baidoshvili, A; Wildevuur, WR; Van Hinsbergh, VWH; Fritz, J; Wildevuur, CRH; Eijsman, L

    Background: Patency of vein grafts in coronary artery bypass grafting procedures is generally less favorable than those of selected arterial grafts. However, vein grafts still are needed in cardiac operations. It would be desirable to find measures to improve the patency of vein grafts next to

  14. Viscoelastic and photo-actuation studies of composites based on polystyrene-grafted carbon nanotubes and styrene-b-isoprene-b-styrene block copolymer

    Czech Academy of Sciences Publication Activity Database

    Ilčíková, M.; Mrlík, M.; Sedláček, T.; Chorvát, D.; Krupa, I.; Šlouf, Miroslav; Koynov, K.; Mosnáček, J.

    2014-01-01

    Roč. 55, č. 1 (2014), s. 211-218 ISSN 0032-3861 R&D Projects: GA TA ČR TE01020118 Institutional support: RVO:61389013 Keywords : thermoplastic elastomers * grafting from surface * smart materials Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 3.562, year: 2014

  15. Microstructure and mechanical properties of stainless steel/calcium silicate composites manufactured by selective laser melting.

    Science.gov (United States)

    Zheng, Zeng; Wang, Lianfeng; Jia, Min; Cheng, Lingyu; Yan, Biao

    2017-02-01

    Selective laser melting (SLM) is raised as one kind of additive manufacturing (AM) which is based on the discrete-stacking concept. This technique can fabricate advanced composites with desirable properties directly from 3D CAD data. In this research, 316L stainless steel (316L SS) and different fractions of calcium silicate (CaSiO 3 ) composites (weight fractions of calcium silicate are 0%, 5%,10% and 15%, respectively) were prepared by SLM technique with a purpose to develop biomedical metallic materials. The relative density, tensile, microhardness and elastic modulus of the composites were tested, their microstructures and fracture morphologies were observed using optical microscope (OM), scanning electron microscopy (SEM) and X-ray diffraction (XRD). It was found that the addition of CaSiO 3 particles influenced the microstructure and mechanical properties of specimens significantly. The CaSiO 3 precipitates from the overlap of adjacent tracks and became the origin of the defects. The tensile strength of specimens range 320-722MPa. The microhardness and elastic modulus are around 250HV and 215GPa respectively. These composites were ductile materials and the fracture mode of the composites was mixed mode of ductile and brittle fracture. The 316L SS/CaSiO 3 composites can be a potential biomedical metallic materials in the medical field. Copyright © 2016. Published by Elsevier B.V.

  16. SLA-constrained service selection for minimizing costs of providing composite cloud services under stochastic runtime performance

    OpenAIRE

    Huang, Kuo-Chan; Tsai, Mu-Jung; Lu, Sin-Ji; Hung, Chun-Hao

    2016-01-01

    Composite cloud services based on the methodologies of Software as a Service and Service-Oriented Architecture are transforming how people develop and use software. Cloud service providers are confronting the service selection problem when composing composite cloud services. This paper deals with an important type of service selection problem, minimizing the total cost of providing a composite cloud service with respect to the constraints of service level agreement (SLA). Two types of SLA are...

  17. Networked Pd (core) @ polyaniline (shell) composite: Highly electro-catalytic ability and unique selectivity

    Science.gov (United States)

    Xia, Youyi; Liu, Ning; Sun, Ling; Xu, Hao; Gao, Hong; Lu, Taofeng

    2018-01-01

    A networked composite (Pd@PANI), which is self-assemblied freely from Pd (core) @polyaniline (shell) nanoparticles, has been prepared successfully by a facilely one-step approach. Owing to the conductive environment and acid-doped behavior provided by PANI, the composite exhibits highly catalytic ability in the reaction involving acidic reactants. For instance, in the HCOOH electro-oxidation, 9.16 times of specific activity (comparing with that when using commercial Pd/C catalyst) is observed. Meanwhile, the as-prepared product is unable to catalyze some other systems like the electro-oxidation of C2H5OH, showing novel and unique selectivity. Those would open up new routes for synthesizing high-performance Pd-based catalysts, and could also shed some light on synthesizing new types of selective catalysts.

  18. Concept selection of car bumper beam with developed hybrid bio-composite material

    International Nuclear Information System (INIS)

    Davoodi, M.M.; Sapuan, S.M.; Ahmad, D.; Aidy, A.; Khalina, A.; Jonoobi, Mehdi

    2011-01-01

    Highlights: → We simulate the low impact test by Abaqus Ver16R9 using the same material model. → Six different weighted criteria were discussed to nominate the best concept. → Double Hat Profile showed the best concept to fulfil the defined PDS. → Geometric parameters may overcome the weak inherent properties of bio composite. → Toughened bio-composite material may employ in structural automotive components. -- Abstract: Application of natural fibre composites is going to increase in different areas caused by environmental, technical and economic advantages. However, their low mechanical properties have limited their particular application in automotive structural components. Hybridizations with other reinforcements or matrices can improve mechanical properties of natural fibre composite. Moreover, geometric optimizations have a significant role in structural strength improvement. This study focused on selecting the best geometrical bumper beam concept to fulfill the safety parameters of the defined product design specification (PDS). The mechanical properties of developed hybrid composite material were considered in different bumper beam concepts with the same frontal curvature, thickness, and overall dimensions. The low-speed impact test was simulated under the same conditions in Abaqus V16R9 software. Six weighted criteria, which were deflection, strain energy, mass, cost, easy manufacturing, and the rib possibility were analyzed to form an evaluation matrix. Topsis method was employed to select the best concept. It is concluded that double hat profile (DHP) with defined material model can be used for bumper beam of a small car. In addition, selected concept can be strengthened by adding reinforced ribs or increasing the thickness of the bumper beam to comply with the defined PDS.

  19. In Arabidopsis thaliana codon volatility scores reflect GC3 composition rather than selective pressure

    Directory of Open Access Journals (Sweden)

    O'Connell Mary J

    2012-07-01

    Full Text Available Abstract Background Synonymous codon usage bias has typically been correlated with, and attributed to translational efficiency. However, there are other pressures on genomic sequence composition that can affect codon usage patterns such as mutational biases. This study provides an analysis of the codon usage patterns in Arabidopsis thaliana in relation to gene expression levels, codon volatility, mutational biases and selective pressures. Results We have performed synonymous codon usage and codon volatility analyses for all genes in the A. thaliana genome. In contrast to reports for species from other kingdoms, we find that neither codon usage nor volatility are correlated with selection pressure (as measured by dN/dS, nor with gene expression levels on a genome wide level. Our results show that codon volatility and usage are not synonymous, rather that they are correlated with the abundance of G and C at the third codon position (GC3. Conclusions Our results indicate that while the A. thaliana genome shows evidence for synonymous codon usage bias, this is not related to the expression levels of its constituent genes. Neither codon volatility nor codon usage are correlated with expression levels or selective pressures but, because they are directly related to the composition of G and C at the third codon position, they are the result of mutational bias. Therefore, in A. thaliana codon volatility and usage do not result from selection for translation efficiency or protein functional shift as measured by positive selection.

  20. Generalizability of a composite student selection procedure at a university-based chiropractic program.

    Science.gov (United States)

    O'Neill, Lotte D; Korsholm, Lars; Wallstedt, Birgitta; Eika, Berit; Hartvigsen, Jan

    2009-01-01

    Non-cognitive admission criteria are typically used in chiropractic student selection to supplement grades. The reliability of non-cognitive student admission criteria in chiropractic education has not previously been examined. In addition, very few studies have examined the overall test generalizability of composites of non-cognitive admission variables in admission to health science programs. The aim of this study was to estimate the generalizability of a composite selection to a chiropractic program, consisting of: application form information, a written motivational essay, a common knowledge test, and an admission interview. Data from 105 Chiropractic applicants from the 2007 admission at the University of Southern Denmark were available for analysis. Each admission parameter was double scored using two random, blinded, and independent raters. Variance components for applicant, rater and residual effects were estimated for a mixed model with the restricted maximum likelihood method. The reliability of obtained applicant ranks (generalizability coefficients) was calculated for the individual admission criteria and for the composite admission procedure. Very good generalizability was found for the common knowledge test (G=1.00) and the admission interview (G=0.88). Good generalizability was found for application form information (G=0.75) and moderate generalizability (G=0.50) for the written motivation essay. The generalizability of the final composite admission procedure, which was a weighted composite of all 4 admission variables was good (G(c) = 0.80). Good generalizability for a composite admission to a chiropractic program was found. Optimal weighting and adequate sampling are important for obtaining optimal generalizability. Limitations and suggestions for future research are discussed.

  1. A New Manufacturing Service Selection and Composition Method Using Improved Flower Pollination Algorithm

    OpenAIRE

    Zhang, Wenyu; Yang, Yushu; Zhang, Shuai; Yu, Dejian; Xu, Yangbing

    2016-01-01

    With an increasing number of manufacturing services, the means by which to select and compose these manufacturing services have become a challenging problem. It can be regarded as a multiobjective optimization problem that involves a variety of conflicting quality of service (QoS) attributes. In this study, a multiobjective optimization model of manufacturing service composition is presented that is based on QoS and an environmental index. Next, the skyline operator is applied to reduce the s...

  2. A multiple criteria service composition selection algorithm supporting time-sensitive rules

    OpenAIRE

    Xu, Lei; Shi, Lei; Wang, Runxin; Jennings, Brendan

    2011-01-01

    Constructing composite services by using of services offered by third parties is an attractive and inexpensive way for service brokers and aggregators to enhance differentiation from their competitors. When multiple services provide the same or similar functionalities, selecting those that satisfy users' non-functional requirements is crucial. In many cases, non-functional properties of services are heavily dependent on the activity of the network delivering those services whilst the network ...

  3. Selected mechanical properties of aluminum composite materials reinforced with SiC particles

    Directory of Open Access Journals (Sweden)

    A. Kurzawa

    2008-07-01

    Full Text Available This work presents the results of research concerning influence of ceramic particles’ content of silicon carbide on selected mechanical properties of type AW-AlCu4Mg2Mn - SiC composite materials. Composites produced of SiC particles with pressure infiltration method of porous preform and subject to hot plastic forming in the form of open die forging were investigated. The experimental samples contained from 5% up to 45% of reinforcing SiC particles of 8÷10μm diameter. Studies of strength properties demonstrated that the best results, in case of tensile strength as well as offset yield strength, might be obtained while applying reinforcement in the amount of 20-25% vol. of SiC. Application of higher than 25% vol. contents of reinforcing particles leads to gradual strength loss. The investigated composites were characterized by very high functional properties, such as hardness and abrasive wear resistance, whose values increase strongly with the increase of reinforcement amount. The presented results of the experiments shall allow for a more precise component selection of composite materials at the stage of planning and design of their properties.

  4. A New Manufacturing Service Selection and Composition Method Using Improved Flower Pollination Algorithm

    Directory of Open Access Journals (Sweden)

    Wenyu Zhang

    2016-01-01

    Full Text Available With an increasing number of manufacturing services, the means by which to select and compose these manufacturing services have become a challenging problem. It can be regarded as a multiobjective optimization problem that involves a variety of conflicting quality of service (QoS attributes. In this study, a multiobjective optimization model of manufacturing service composition is presented that is based on QoS and an environmental index. Next, the skyline operator is applied to reduce the solution space. And then a new method called improved Flower Pollination Algorithm (FPA is proposed for solving the problem of manufacturing service selection and composition. The improved FPA enhances the performance of basic FPA by combining the latter with crossover and mutation operators of the Differential Evolution (DE algorithm. Finally, a case study is conducted to compare the proposed method with other evolutionary algorithms, including the Genetic Algorithm, DE, basic FPA, and extended FPA. The experimental results reveal that the proposed method performs best at solving the problem of manufacturing service selection and composition.

  5. Multiple criteria decision making with life cycle assessment for material selection of composites

    Directory of Open Access Journals (Sweden)

    A. S. Milani

    2011-12-01

    Full Text Available With the advancement of interdisciplinary approaches in today’s modern engineering, current efforts in optimal design of composites include seeking material selection protocols that can (1 simultaneously consider a series of mechanical/electrical/chemical cost criteria over a set of alternative material options, and (2 closely take into account environmental aspects of final products including recycling and end-of-life disposal options. In this paper, in addition to a review of some recent experimental and methodological advances in the above areas, a new application of multiple criteria decision making (MCDM is presented to deal with decision conflicts often seen among design criteria in composite material selection with the help of life cycle assessment (LCA. To show the application, an illustrative case study on a plastic gear material selection is conducted where the cost, mechanical and thermal properties along with environmental impact criteria are to be satisfied simultaneously. A pure plastic gear is compared to a Polyethylene terephthalate (PET/aluminum-powder composite alternative. Results suggest that simple MCDM models, including a signal-to-noise measure adapted to MCDM in the same case study, can be used to explore both trade-offs and design break-even points in large decision spaces as the decision maker’s perspective over environmental, material performance and cost attributes change during the design process. More advanced topics including the account of material data uncertainties are addressed.

  6. Breeding graft-compatible Douglas-fir rootstocks (Pseudotsuga menziesii (Mirb.) Franco).

    Science.gov (United States)

    D.L. Copes

    1999-01-01

    A study encompassing 24 years was conducted to determine if a breeding program could produce highly graft-compatible rootstocks. Twenty-seven trees of apparent high graft compatibility were selected and crossed to produce 226 control-pollinated families. Seedlings were grown, field planted, and grafted with test scions. Graft unions from field tests were evaluated...

  7. Grafting and curing

    International Nuclear Information System (INIS)

    Garnett, J.L.; Loo-Teck Ng; Visay Viengkhou

    1998-01-01

    Progress in radiation grafting and curing is briefly reviewed. The two processes are shown to be mechanistically related. The parameters influencing yields are examined particularly for grafting. For ionising radiation grafting systems (EB and gamma ray) these include solvents, substrate and monomer structure, dose and dose-rate, temperature and more recently role of additives. In addition, for UV grafting, the significance of photoinitiators is discussed. Current applications of radiation grafting and curing are outlined. The recent development of photoinitiator free grafting and curing is examined as well as the potential for the new excimer laser sources. The future application of both grafting and curing is considered, especially the significance of the occurrence of concurrent grafting during cure and its relevance in environmental considerations

  8. 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.

  9. Multi-objective selection and optimization of shaped materials and laminated composites

    Science.gov (United States)

    Singh, Jasveer

    Most of the current optimization techniques for the design of light-weight structures are unable to generate structural alternatives at the concept stage of design. This research tackles the challenge of developing methods for the early stage of design involving structures made up of conventional materials and composite laminates. For conventional materials, the recently introduced shape transformer approach is used. This work extends the method to deal with the case of torsional stiffness design, and generalizes it to single and multi-criteria selection of lightweight shafts subjected to a combination of bending, shear, and torsional load. The prominent feature of the work is the useful integration of shape and material to model and visualize multi-objective selection problems. The scheme is centered on concept selection in structural design, and hinges on measures that govern the shape properties of a cross-section regardless of its size. These measures, referred to as shape transformers, can classify shapes in a way similar to material classification. The procedure is demonstrated by considering torsional stiffness as a constraint. Performance charts are developed for both single and multi-criteria cases to let the reader visualize in a glance the whole range of cross-sectional shapes for each material. Each design chart is explained with a brief example. The above mentioned approach is also extended to incorporate orthotropic composite laminates. Design charts are obtained for the selection of five generic design variables: shape, size, material, layup, and number of plies. These charts also aid in comparing the performances of two commonly used laminates in bending and torsion - angle plies and cross plies. For a generic composite laminate, due to the number of variables involved, these kinds of design charts are very difficult. However, other tactics like using an analytical model for function evaluation can be used at conceptual stage of design. This is

  10. Gender saturation in the Southern Caucasus: family composition and sex-selective abortion.

    Science.gov (United States)

    Garenne, Michel; Hohmann, Sophie

    2014-11-01

    The study investigates the complex relationships between sex-selective abortion and family composition in two countries of the Southern Caucasus: Armenia and Azerbaijan. Data were drawn from maternity histories recorded in Demographic and Health Surveys (DHSs). In both countries, the relationship between the sex ratio of the next birth and the number of girls already born changed from negative to positive after 1992, when sex-selective abortion became prevalent. In Azerbaijan, but not in Armenia, a similar change was noticed for the relationship between the sex ratio of the next birth and the number of boys already born, this time from positive to negative. All changes in slopes were highly statistically significant. These findings indicate that sex-selective abortion was prevalent in both countries, and could work both ways in Azerbaijan. The results are interpreted in terms of 'gender saturation', that is a desire of families to better balance the composition of the family when too many children of the same sex are already born, which is consistent with opinion surveys indicating a preference for balanced families.

  11. Poly (methyl methacrylate) Composites with Size-Selected Silver Nanoparticles Fabricated using Cluster Beam Technique

    DEFF Research Database (Denmark)

    Hanif, Muhammad; Juluri, Raghavendra Rao; Chirumamilla, Manohar

    2016-01-01

    An embedment of metal nanoparticles of well-defined sizes in thin polymer films is of significant interest for a number of practical applications, in particular, for preparing materials with tunable plasmonic properties. In this article, we present a fabrication route for metal–polymer composites...... tendency to flattening upon impact. By controlling the polymer hardness (from viscous to soft state) prior the cluster deposition and annealing conditions after the deposition the degree of immersion of the nanoparticles into polymer can be tuned, thus, making it possible to create composites with either...... particles partly or fully embedded into the film. Good size selection and rather homogeneous dispersion of nanoparticles in the thin polymer film lead to excellent plasmonic properties characterized by the narrow band and high quality factor of localized surface plasmon resonance....

  12. POLYMER COMPOSITE FILMS WITH SIZE-SELECTED METAL NANOPARTICLES FABRICATED BY CLUSTER BEAM TECHNIQUE

    DEFF Research Database (Denmark)

    Ceynowa, F. A.; Chirumamilla, Manohar; Popok, Vladimir

    2017-01-01

    Formation of polymer films with size-selected silver and copper nanoparticles (NPs) is studied. Polymers are prepared by spin coating while NPs are fabricated and deposited utilizing a magnetron sputtering cluster apparatus. The particle embedding into the films is provided by thermal annealing...... after the deposition. The degree of immersion can be controlled by the annealing temperature and time. Together with control of cluster coverage the described approach represents an efficient method for the synthesis of thin polymer composite layers with either partially or fully embedded metal NPs....... Combining electron beam lithography, cluster beam deposition and thermal annealing allows to form ordered arrays of metal NPs on polymer films. Plasticity and flexibility of polymer host and specific properties added by coinage metal NPs open a way for different applications of such composite materials...

  13. Selection of key foods for the systematic management of a food and nutrient composition database.

    Science.gov (United States)

    Shim, Jee-Seon; Lee, Jung-Sug; Kim, Ki Nam; Lee, Hyun Sook; Kim, Hye Young; Chang, Moon-Jeong

    2017-12-01

    Food composition databases are necessary for assessing dietary intakes. Developing and maintaining a high quality database is difficult because of the high cost of analyzing nutrient profiles and the recent fast-changing food marketplace. Thus, priorities have to be set for developing and updating the database. We aimed to identify key foods in the Korean diet to set priorities for future analysis of foods. modified the US Department of Agriculture's key food approach. First, major foods were analyzed, contributing to 75%, 80%, 85%, or 90% of each nutrient intake. Second, the cumulative contributions to nutrient intakes were compared before and after excluding the foods least commonly consumed by individuals. Third, total nutrient score for each food was calculated by summing all percent contributions times 100 for nutrients. To set priorities among the foods in the list, we sorted the score in descending order and then compared total percent contributions of foods, within the 100, 90, 85, 80, and 75 percentiles of the list. Finally, we selected the minimum list of foods contributing to at least 90% of the key nutrient intake as key items for analysis. Among the 1,575 foods consumed by individuals, 456 were selected as key foods. Those foods were chosen as items above the 80 percentile of the total nutrient score, among the foods contributing at least 85% of any nutrient intake. On an average, the selected key foods contributed to more than 90% of key nutrient intake. In total, 456 foods, contributing at least 90% of the key nutrient intake, were selected as key foods. This approach to select a minimum list of key foods will be helpful for systematically updating and revising food composition databases.

  14. Self-Assembly of Grafted Nanoparticles for Transport Channels in Membranes

    Science.gov (United States)

    Bilchak, Connor; Buenning, Ellie; Durning, Christopher; Kumar, Sanat

    2015-03-01

    Polymer membranes have seen increased application for vapor separations, particularly for natural gas processing and purification. The addition of nanoparticles to such membranes has led to conflicting findings; conventional (Maxwell) composite theory predicts the addition of inert filler to hinder membrane transport properties. However, our research using silica nanoparticles grafted with Poly (Methacrylate) has shown these grafted systems to possess permeabilities similar to those of a pure polymer system increasing penetrant solubility without compromising diffusivity. This is counterintuitive to Maxwell theory. We propose that the grafted nanoparticles self-assemble into an ordered crystal lattice containing low-density ``channels'' which facilitate penetrant uptake. Atomic force microscopy and small-angle neutron scattering experiments appear to confirm this theory. Varying polymer grafting density and chain length is also predicted to alter transport properties, allowing for the fabrication of membrane with tunable diffusivity and selectivity. These grafted nanocomposite systems therefore represent a means of creating robust membranes with transport properties similar to those of conventional polymeric films that may be easily adapted for various separations processes. Corresponding author.

  15. Carbon dioxide selective mixed matrix composite membrane containing ZIF-7 nano-fillers

    KAUST Repository

    Li, Tao

    2013-01-01

    Mixed matrix materials made from selective inorganic fillers and polymers are very attractive for the manufacturing of gas separation membranes. But only few of these materials could be manufactured into high-performance asymmetric or composite membranes. We report here the first mixed matrix composite membrane made of commercially available poly (amide-b-ethylene oxide) (Pebax®1657, Arkema) mixed with the nano-sized zeolitic imidazole framework ZIF-7. This hybrid material has been successfully deposited as a thin layer (less than 1μm) on a porous polyacrylonitrile (PAN) support. An intermediate gutter layer of PTMSP was applied to serve as a flat and smooth surface for coating to avoid polymer penetration into the porous support. Key features of this work are the preparation and use of ultra-small ZIF-7 nano-particles (around 30-35nm) and the membrane processability of Pebax®1657. SEM pictures show that excellent adhesion and almost ideal morphology between the two phases has been obtained simply by mixing the as-synthesized ZIF-7 suspension into the Pebax®1657 dope, and no voids or clusters can be observed. The performance of the composite membrane is characterized by single gas permeation measurement of CO2, N2 and CH4. Both, permeability (PCO2 up to 145barrer) and gas selectivity (CO2/N2 up to 97 and CO2/CH4 up to 30) can be increased at low ZIF- loading. The CO2/CH4 selectivity can be further increased to 44 with the filler loading of 34wt%, but the permeability is reduced compared to the pure Pebax®1657 membrane. Polymer chain rigidification at high filler loading is supposed to be a reason for the reduced permeability. The composite membranes prepared in this work show better performance in terms of permeance and selectivity when compared with asymmetric mixed matrix membranes described in the recent literature. Overall, the ZIF 7/Pebax mixed matrix membranes show a high performance for CO2 separation from methane and other gas streams. They are easy to

  16. Methods for the selective detection of alkyne-presenting molecules and related compositions and systems

    Science.gov (United States)

    Valdez, Carlos A.; Vu, Alexander K.

    2017-10-17

    Provided herein are methods for selectively detecting an alkyne-presenting molecule in a sample and related detection reagents, compositions, methods and systems. The methods include contacting a detection reagent with the sample for a time and under a condition to allow binding of the detection reagent to the one or more alkyne-presenting molecules possibly present in the matrix to the detection reagent. The detection reagent includes an organic label moiety presenting an azide group. The binding of the azide group to the alkyne-presenting molecules results in emission of a signal from the organic label moiety.

  17. Influence of aging solutions on wear resistance and hardness of selected resin-based dental composites.

    Science.gov (United States)

    Chladek, Grzegorz; Basa, Katarzyna; Żmudzki, Jarosław; Malara, Piotr; Nowak, Agnieszka J; Kasperski, Jacek

    2016-01-01

    The purpose of this study was to investigate the effect of different plasticizing aging solutions on wear resistance and hardness of selected universal resin-based dental composites. Three light cured (one nanofilled, two microhybride) and one hybride chemical cured composites were aged at 37 °C for 48 h in distillated water, ethyl alcohol solution or Listerine mouthwash. After aging the microhardness tests were carried out and then tribological tests were performed in the presence of aging solution at 37 °C. During wear testing coefficients of friction were determined. The maximal vertical loss in micrometers was determined with profilometer. Aging in all liquids resulted in a significant decrease in hardness of the test materials, with the largest values obtained successively in ethanol solution, mouthwash and water. The effect of the liquid was dependent on the particular material, but not the type of material (interpreted as the size of filler used). Introduction of mouthwash instead of water or ethanol solution resulted in a significant reduction in the coefficient of friction. The lowest wear resistance was registered after aging in ethanol and for the chemical cured hybrid composite, but the vertical loss was strongly material dependent. The effect of different aging solution, including commercial mouthrinse, on hardness and wear was material dependent, and cannot be deduced from their category or filler loading. There is no simple correlation between hardness of resin-based dental composites and their wear resistance, but softening of particular composites materials during aging leads to the reduction of its wear resistance.

  18. Carbon nanotube grafted with polyalcohol and its influence on the thermal conductivity of phase change material

    International Nuclear Information System (INIS)

    Li, Min; Chen, Meirong; Wu, Zhishen; Liu, Jianxun

    2014-01-01

    Highlights: • CNTs are grafted with polyhydric alcohols. • The grafted CNTs are well dispersed. • The graft ratio of CNTs-C8, CNTs-C14 and CNTs-C18 is 11%, 32% and 38%. • The thermal conductivities of CNTs/paraffin are increased through graft treatment. • The carbon number of polyalcohol has influence on thermal conductivity. - Abstract: Carbon nanotubes (CNTs) were grafted with polyhydric alcohols (octanol, tetradecyl alchohol and stearyl alcohol) after acidification. The composite phase change materials (PCMs) were prepared with grafted CNTs and paraffin. The grafted CNTs were characterized with Transmission Electron Micrograph (TEM), X-ray Diffractometer (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Thermogravimetric analyzer (TG). Hot disk method was employed to measure the thermal conductivity of composite PCMs. The results showed that polyhydric alcohols were grafted onto CNTs. The graft ratio was 38% for the CNTs grafted with stearyl alcohol. The grafted CNTs were shorter than CNTs and the dispersibility of grafted CNTs was better than that of CNTs. The thermal conductivity of grafted CNTs/paraffin composite PCMs was higher than that of pristine CNTs/paraffin composite PCMs

  19. Seleção de matrizes e tipo de propágulo na enxertia de substituição de copa em Ilex paraguariensis Stock plants selection and ramet types for crown grafting in Ilex paraguariensis

    Directory of Open Access Journals (Sweden)

    Ivar Wendling

    2009-10-01

    ao pegamento na enxertia.The objective of this research was to evaluate the technique of topgrafting in Ilex paraguariensis. For that reason, the influence of the position of the graft in the stock plant, the age and the stock plant, as well as, the definition of the best time for grafting evaluation and vigor of the grafts were evaluated. 13 years old trees located in Colombo - PR were submitted to the cut at 10 cm above the soil for sprouts induction, on which the grafting was accomplished by top cleft grafting. The grafts were collected from 10 year-old mother trees and from seven trees older than 80 years. From the selected trees grafts were taken from the top, medium and basal position inside the mother tree. The experiment was installed with three replications and 42 treatments, in a hierarchical factorial design 2 x 7 x 3 (two ages, seven mother trees for each age and three collection positions. The variables of interest were percentage of survival and number and length of sprouts. A differentiated performance of the mother trees when in different collection positions was observed. The individual heritability of the genotipic effects, estimated for the survival of the grafts, was superior to 74%, for all the evaluation periods, which is considered very high. The coefficient of genetic variation was 34%, for the observed periods same or superior to 90 days, indicating good genetic gain perspectives for the improvement of the genetic material. The coefficients of experimental variation, obtained for that same periods were between 78% and 94%. It can be observed that there were no differences among the genetic parameters indicating the possibility of evaluation of the survival of the grafts after 90 days. Based on those results it can be concluded that the Ilex paraguariensis topgrafting directly in the field is technically viable; better survival of grafting are obtained for young trees and with apical sprouts; mother trees have shown differentiated responses in

  20. Separation of several alcohol-benzene mixtures by pervaporation through styrene graft polyethylene membranes

    International Nuclear Information System (INIS)

    Murata, Kenichi

    1989-01-01

    The permeation of pure liquids, such as methanol, ethanol, 1-propanol, 2-propanol and benzene, and the permeability and selectivity of 50 vol% binary mixtures of these alcohols and benzene were investigated by pervaporation technique. The used membranes (21%, 40%, and 72% graftings) were obtained by graft polymerization of styrene to polyethylene film (thickness 10 μm) by γ-radiation. The permeation rates of each of these alcohols and benzene were measured by pervaporation through the graft membranes. Those of these alcohols were very small as well as those through the original membrane. On the other hand, the permeabilities for benzene through the graft membranes were larger than that through the original membrane. The temperature dependence of the permeation rate for benzene was expressed by Arrhenius-type relationships, and the apparent activation energies were calculated to be 10.7 (21%), 10.2 (40%) and 10.0 (72%) kcal/mol. In the permeation of 50 vol% several alcohol-benzene mixtures, the permeabilities through the graft membranes were also larger than that through the original membrane, and increased with the grafting. The temperature dependence of the permeation for these mixtures was showed by Arrhenius relationships, and the apparent activation energies were calculated to be in the range of 8.4∼11.0 kcal/mol. The separation factors of the graft membranes calculated from composition of the permeates were always smaller than that of the original membrane, but became larger with increase of molecular volume of alcohol in alcohol-benzene mixtures. (author)

  1. Effects of LDEF flight exposure on selected polymer matrix resin composite materials

    Science.gov (United States)

    Slemp, Wayne S.; Young, Philip R.; Witte, William G., Jr.; Shen, James Y.

    1992-01-01

    The characterization of selected graphite fiber reinforced epoxy (934 and 5208) and polysulfone (P1700) matrix resin composites materials which received over five years and nine months of exposure to the low earth orbit (LEO) environment in experiment AO134 on the Long Duration Exposure Facility is reported. The changes in mechanical properties of ultimate tensile strength and tensile modulus for exposed flight specimens are compared to the three sets of control specimens. Marked changes in surface appearance are discussed, and resin loss is reported. The chemical characterization including infrared, thermal, and selected solution property measurements showed that the molecular structure of the polymetric matrix had not changed significantly in response to this exposure.

  2. Microstructure and mechanical properties of a novel β titanium metallic composite by selective laser melting

    International Nuclear Information System (INIS)

    Vrancken, B.; Thijs, L.; Kruth, J.-P.; Van Humbeeck, J.

    2014-01-01

    Selective laser melting (SLM) is an additive manufacturing process in which functional, complex parts are produced by selectively melting consecutive layers of powder with a laser beam. This flexibility enables the exploration of a wide spectrum of possibilities in creating novel alloys or even metal–metal composites with unique microstructures. In this research, Ti6Al4V-ELI powder was mixed with 10 wt.% Mo powder. In contrast to the fully α′ microstructure of Ti6Al4V after SLM, the novel microstructure consists of a β titanium matrix with randomly dispersed pure Mo particles, as observed by light optical microscopy, scanning electron microscopy and X-ray diffraction. Most importantly, the solidification mechanism changes from planar to cellular mode. Microstructures after heat treatment indicate that the β phase is metastable and locate the β transus at ∼900 °C, and tensile properties are equal to or better than conventional β titanium alloys

  3. Genetic grouping strategies in selection efficiency of composite beef cattle ( × ).

    Science.gov (United States)

    Petrini, J; Pertile, S F N; Eler, J P; Ferraz, J B S; Mattos, E C; Figueiredo, L G G; Mourão, G B

    2015-02-01

    The inclusion of genetic groups in sire evaluation has been widely used to represent genetic differences among animals not accounted for by the absence of parentage data. However, the definition of these groups is still arbitrary, and studies assessing the effects of genetic grouping strategies on the selection efficiency are rare. Therefore, the aim in this study was to compare genetic grouping strategies for animals with unknown parentage in prediction of breeding values (EBV). The total of 179,302 records of weaning weight (WW), 29,825 records of scrotal circumference (SC), and 70,302 records of muscling score (MUSC) from Montana Tropical animals, a Brazilian composite beef cattle population, were used. Genetic grouping strategies involving year of birth, sex of the unknown parent, birth farm, breed composition, and their combinations were evaluated. Estimated breeding values were predicted for each approach simulating a loss of genealogy data. Thereafter, these EBV were compared to those obtained in an analysis involving a real relationship matrix to estimate selection efficiency and correlations between EBV and animal rankings. The analysis model included the fixed effects of contemporary groups and class of the dam age at calving, the covariates of additive and nonadditive genetic effects, and age, and the additive genetic effect of animal as random effects. A second model also included the fixed effects of genetic group. The use of genetic groups resulted in means of selection efficiency and correlation of 70.4 to 97.1% and 0.51 to 0.94 for WW, 85.8 to 98.8% and 0.82 to 0.98 for SC, and 85.1 to 98.6% and 0.74 to 0.97 for MUSC, respectively. High selection efficiencies were observed for year of birth and breed composition strategies. The maximum absolute difference in annual genetic gain estimated through the use of complete genealogy and genetic groups were 0.38 kg for WW, 0.02 cm for SC, and 0.01 for MUSC, with lower differences obtained when year of birth

  4. Synthesis of Au microwires by selective oxidation of Au–W thin-film composition spreads

    Directory of Open Access Journals (Sweden)

    Sven Hamann, Hayo Brunken, Steffen Salomon, Robert Meyer, Alan Savan and Alfred Ludwig

    2013-01-01

    Full Text Available We report on the stress-induced growth of Au microwires out of a surrounding Au–W matrix by selective oxidation, in view of a possible application as 'micro-Velcro'. The Au wires are extruded due to the high compressive stress in the tungsten oxide formed by oxidation of elemental W. The samples were fabricated as a thin-film materials library using combinatorial sputter deposition followed by thermal oxidation. Sizes and shapes of the Au microwires were investigated as a function of the W to Au ratio. The coherence length and stress state of the Au microwires were related to their shape and plastic deformation. Depending on the composition of the Au–W precursor, the oxidized samples showed regions with differently shaped Au microwires. The Au48W52 composition yielded wires with the maximum length to diameter ratio due to the high compressive stress in the tungsten oxide matrix. The values of wire length (35 μm and diameter (2 μm achieved at the Au48W52 composition are suitable for micro-Velcro applications.

  5. Standard Practice for Steel Bars, Selection Guide, Composition, and Mechanical Properties

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2012-01-01

    1.1 This practice is intended as a guide for the selection of steel bars according to section and to the mechanical properties desired in the part to be produced. This is not a specification for the procurement of steel. Applicable procurement specifications are listed in Section 5. 1.2 Several steel compositions intended for various sections and mechanical property requirements are presented in Tables 2 to 7. The criteria for placing a steel composition in one of the three general class designations, Classes P, Q, and R (described in Section 3) are as follows: 1.2.1 Classes P and Q should be capable of developing the mechanical properties shown in Tables 2 to 5 by liquid quenching from a suitable austenitizing temperature, and tempering at 800°F (427°C) or higher. A hardness indicated by tests made at a location shown in Fig. 1, A, B, or C, is taken as evidence that a composition is capable of meeting other equivalent mechanical properties shown in the tables. Normal good shop practices are assumed, with c...

  6. Development of shrinkage and fracture parameters in selected fine-grained cement-based composites

    Directory of Open Access Journals (Sweden)

    Kucharczyková Barbara

    2017-01-01

    Full Text Available The paper summarizes results of a pilot study aimed at the evaluation of an experimental investigation focused on determination of the material characteristics development of selected fine-grained cement-based composites during their ageing. The composition of composites being investigated differed only in a water to cement (w/c ratio and in amount of superplasticizer. Quite extensive experiments were performed with the aim to determine shrinkage, dynamic a static modulus of elasticity and fracture properties on test specimens exposed to free drying during the whole time of its ageing (including the early stage of setting and hardening. The article presents especially results (including their statistical evaluation of shrinkage and fracture parameters development within 90 days of composites’ ageing. Experimental results show the dependence of the investigated characteristics on the value of w/c ratio. The most visible effect was observed in the case of shrinkage development. The curing conditions were reflected especially in high variability of the test results.

  7. Unemployment and health selection in diverging economic conditions: Compositional changes? Evidence from 28 European countries.

    Science.gov (United States)

    Heggebø, Kristian; Dahl, Espen

    2015-11-04

    Unemployment and health selection in diverging economic conditions: Compositional changes? Evidence from 28 european countries. People with ill health tend to be overrepresented among the unemployment population. The relationship between health and unemployment might, however, be sensitive to the overall economic condition. Specifically, the health composition of the unemployment population could change dramatically when the economy takes a turn for the worse. Using EU-SILC cross sectional data from 2007 (pre-crisis) and 2011 (during crisis) and linear regression models, this paper investigates the relationship between health and unemployment probabilities under differing economic conditions in 28 European countries. The countries are classified according to (i) the level of and (ii) increase in unemployment rate (i.e. >10 percent and doubling of unemployment rate = crisis country). Firstly, the unemployment likelihood for people with ill health is remarkably stable over time in Europe: the coefficients are very similar in pre-crisis and crisis years. Secondly, people with ill health have experienced unemployment to a lesser extent than those with good health status in the crisis year (when we pool the data and compare 2007 and 2011), but only in the countries with a high and rising unemployment rate. The health composition of the unemployment population changes significantly for the better, but only in those European countries that have been severely hit by the current economic crisis.

  8. Thermomechanical Behavior of Polymer Composites Based on Edge-Selectively Functionalized Graphene Nanosheets

    Directory of Open Access Journals (Sweden)

    Ki-Ho Nam

    2017-12-01

    Full Text Available In this study, we demonstrate an effective approach based on a simple processing method to improve the thermomechanical properties of graphene polymer composites (GPCs. Edge-selectively functionalized graphene (EFG was successfully obtained through simple ball milling of natural graphite in the presence of dry ice, which acted as the source of carboxyl functional groups that were attached to the peripheral basal plane of graphene. The resultant EFG is highly dispersible in various organic solvents and contributes to improving their physical properties because of its unique characteristics. Pyromellitic dianhydride (PMDA and 4,4′-oxydianiline (ODA were used as monomers for constructing the polyimide (PI backbone, after which PI/EFG composites were prepared by in situ polymerization. A stepwise thermal imidization method was used to prepare the PI films for comparison purposes. The PI/EFG composite films were found to exhibit reinforced thermal and thermo-mechanical properties compared to neat PI owing to the interaction between the EFG and PI matrix.

  9. Phase composition and microstructure of WC-Co alloys obtained by selective laser melting

    Science.gov (United States)

    Khmyrov, Roman S.; Shevchukov, Alexandr P.; Gusarov, Andrey V.; Tarasova, Tatyana V.

    2018-03-01

    Phase composition and microstructure of initial WC, BK8 (powder alloy 92 wt.% WC-8 wt.% Co), Co powders, ball-milled powders with four different compositions (1) 25 wt.% WC-75 wt.% Co, (2) 30 wt.% BK8-70 wt.% Co, (3) 50 wt.% WC-50 wt.% Co, (4) 94 wt.% WC-6 wt.% Co, and bulk alloys obtained by selective laser melting (SLM) from as-milled powders in as-melted state and after heat treatment were investigated by scanning electron microscopy and X-ray diffraction analysis. Initial and ball-milled powders consist of WC, hexagonal α-Co and face-centered cubic β-Co. The SLM leads to the formation of major new phases W3Co3C, W4Co2C and face-centered cubic β-Co-based solid solution. During the heat treatment, there occurs partial decomposition of the face-centered cubic β-Co-based solid solution with the formation of W2C and hexagonal α-Co solid solution. The microstructure of obtained bulk samples, in general, corresponds to the observed phase composition.

  10. Selective control of reformed composition of n-heptane via plasma chemistry

    KAUST Repository

    Manoj Kumar Reddy, P.

    2016-08-23

    This paper presents experimental results for reforming n-heptane in a temperature-controlled dielectric barrier discharge reactor to show detailed chemical composition in the products and to propose a potential method to control the product composition. Reformed products of n-heptane and water mixture in an inert Ar feed could be identified as hydrogen, carbon monoxide, oxygenates, and various hydrocarbons, having a wide range of carbon numbers. To selectively increase production of short-chain hydrocarbons, Ar was replaced by CH4. An increased pool of methyl radicals, via plasma chemistry of CH4, might facilitate to stabilize intermediate alkyls (R) into RCH3, which successfully increased short-chain hydrocarbon concentration. When CO2 was supplied instead of Ar (to provide enriched OH and O radicals), significantly higher oxygenate concentrations were obtained through the stabilization of alkyls as ROH (alcohol), and RC([Formula presented])R′ (ketone). The use of methane and carbon dioxide as feed to tailor the products of plasma-assisted reforming of n-heptane with methyl (CH3), or O radicals, is successfully demonstrated in the presence of water vapor. Detailed product analysis, such as product selection, rates and energy efficiency using a gas chromatograph and a gas chromatography mass spectrometer, will be elaborated upon. © 2016 Elsevier Ltd

  11. Non-Vascularised Fibular Grafting After Resection of Distal Femoral ...

    African Journals Online (AJOL)

    Background: Vascularized fibular grafting, allografting, megaprosthesis and allograft-prosthesis composite are suitable limb salvage techniques after resection of ... the initial observation showed such a wide non-vascularized fibular grafting for arthrodesis of the knee after resection of the distal femoral tumours is a feasible ...

  12. Divergent selection-induced obesity alters the composition and functional pathways of chicken gut microbiota.

    Science.gov (United States)

    Ding, Jinmei; Zhao, Lele; Wang, Lifeng; Zhao, Wenjing; Zhai, Zhengxiao; Leng, Li; Wang, Yuxiang; He, Chuan; Zhang, Yan; Zhang, Heping; Li, Hui; Meng, He

    2016-11-28

    The gastrointestinal tract is populated by a complex and vast microbial network, with a composition that reflects the relationships of the symbiosis, co-metabolism, and co-evolution of these microorganisms with their host. The mechanism that underlies such interactions between the genetics of the host and gut microbiota remains elusive. To understand how genetic variation of the host shapes the gut microbiota and interacts with it to affect the metabolic phenotype of the host, we compared the abundance of microbial taxa and their functional performance between two lines of chickens (fat and lean) that had undergone long-term divergent selection for abdominal fat pad weight, which resulted in a 4.5-fold increase in the fat line compared to the lean line. Our analysis revealed that the proportions of Fusobacteria and Proteobacteria differed significantly between the two lines (8 vs. 18% and 33 vs. 24%, respectively) at the phylum level. Eight bacterial genera and 11 species were also substantially influenced by the host genotype. Differences between the two lines in the frequency of host alleles at loci that influence accumulation of abdominal fat were associated with differences in the abundance and composition of the gut microbiota. Moreover, microbial genome functional analysis showed that the gut microbiota was involved in pathways that are associated with fat metabolism such as lipid and glycan biosynthesis, as well as amino acid and energy metabolism. Interestingly, citrate cycle and peroxisome proliferator activated receptor (PPAR) signaling pathways that play important roles in lipid storage and metabolism were more prevalent in the fat line than in the lean line. Our study demonstrates that long-term divergent selection not only alters the composition of the gut microbiota, but also influences its functional performance by enriching its relative abundance in microbial taxa. These results support the hypothesis that the host and gut microbiota interact at the

  13. A comparative clinico-radiographic study of guided tissue regeneration with bioresorbable membrane and a composite synthetic bone graft for the treatment of periodontal osseous defects

    Directory of Open Access Journals (Sweden)

    Sumedha Srivastava

    2015-01-01

    Full Text Available Aim: The aim was to evaluate the bonefill in periodontal osseous defects with the help of guided tissue regeneration, bioresorbable membrane (PerioCol + bone graft (Grabio Glascera in combination and with bonegraft (Grabio Glascera alone. Materials and Methods: The study involved total 30 sites in systemically healthy 19 patients. The parameters for evaluation includes plaque index sulcus bleeding index with one or more periodontal osseous defects having (i probing depth (PD of ≥ 5 mm (ii clinical attachment loss (CAL of ≥ 5 mm and (iii ≥3 mm of radiographic periodontal osseous defect (iv bonefill (v crestal bone loss (vi defect resolution. The study involved the three wall and two wall defects which should be either located interproximally or involving the furcation area. The statistical analysis was done using Statistical Package for Social Sciences, the Wilcoxon signed rank statistic W + for Mann-Whitney U-test. Results: The net gain in PD and CAL after 6 months for Group I ([PerioCol] + [Grabio Glascera] and Group II (Grabio Glascera was 3.94 ± 1.81 mm, 3.57 ± 2.21 mm and 3.94 ± 1.81, 3.57 ± 2.21 mm, respectively. The results of the study for Group I and Group II with regards to mean net bonefill, was 3.25 ± 2.32 (58% mm and 5.14 ± 3.84 (40.26 ± 19.14% mm, crestal bone loss − 0.25 ± 0.68 mm and − 0.79 ± 1.19 mm. Defect resolution 3.50 ± 2.34 mm and 5.93 ± 4.01 mm, respectively. Conclusion: On comparing both the groups together after 6 months of therapy, the results were equally effective for combination of graft and membrane versus bone graft alone since no statistical significant difference was seen between above parameters for both the groups. Thus, both the treatment modalities are comparable and equally effective.

  14. Evolutionary mirages: selection on binding site composition creates the illusion of conserved grammars in Drosophila enhancers.

    Directory of Open Access Journals (Sweden)

    Richard W Lusk

    2010-01-01

    Full Text Available The clustering of transcription factor binding sites in developmental enhancers and the apparent preferential conservation of clustered sites have been widely interpreted as proof that spatially constrained physical interactions between transcription factors are required for regulatory function. However, we show here that selection on the composition of enhancers alone, and not their internal structure, leads to the accumulation of clustered sites with evolutionary dynamics that suggest they are preferentially conserved. We simulated the evolution of idealized enhancers from Drosophila melanogaster constrained to contain only a minimum number of binding sites for one or more factors. Under this constraint, mutations that destroy an existing binding site are tolerated only if a compensating site has emerged elsewhere in the enhancer. Overlapping sites, such as those frequently observed for the activator Bicoid and repressor Krüppel, had significantly longer evolutionary half-lives than isolated sites for the same factors. This leads to a substantially higher density of overlapping sites than expected by chance and the appearance that such sites are preferentially conserved. Because D. melanogaster (like many other species has a bias for deletions over insertions, sites tended to become closer together over time, leading to an overall clustering of sites in the absence of any selection for clustered sites. Since this effect is strongest for the oldest sites, clustered sites also incorrectly appear to be preferentially conserved. Following speciation, sites tend to be closer together in all descendent species than in their common ancestors, violating the common assumption that shared features of species' genomes reflect their ancestral state. Finally, we show that selection on binding site composition alone recapitulates the observed number of overlapping and closely neighboring sites in real D. melanogaster enhancers. Thus, this study calls into

  15. Engineered vascularized bone grafts

    OpenAIRE

    Tsigkou, Olga; Pomerantseva, Irina; Spencer, Joel A.; Redondo, Patricia A.; Hart, Alison R.; O’Doherty, Elisabeth; Lin, Yunfeng; Friedrich, Claudia C.; Daheron, Laurence; Lin, Charles P.; Sundback, Cathryn A.; Vacanti, Joseph P.; Neville, Craig

    2010-01-01

    Clinical protocols utilize bone marrow to seed synthetic and decellularized allogeneic bone grafts for enhancement of scaffold remodeling and fusion. Marrow-derived cytokines induce host neovascularization at the graft surface, but hypoxic conditions cause cell death at the core. Addition of cellular components that generate an extensive primitive plexus-like vascular network that would perfuse the entire scaffold upon anastomosis could potentially yield significantly higher-quality grafts. W...

  16. Multidimensional CAT Item Selection Methods for Domain Scores and Composite Scores with Item Exposure Control and Content Constraints

    Science.gov (United States)

    Yao, Lihua

    2014-01-01

    The intent of this research was to find an item selection procedure in the multidimensional computer adaptive testing (CAT) framework that yielded higher precision for both the domain and composite abilities, had a higher usage of the item pool, and controlled the exposure rate. Five multidimensional CAT item selection procedures (minimum angle;…

  17. Selective determination of dopamine with a cibacron blue/poly-1,5-diaminonaphthalene composite film

    Energy Technology Data Exchange (ETDEWEB)

    Abdelwahab, Adel A.; Lee, Hak-Myoung [Department of Chemistry and Center for Innovative BioPhysio Sensor Technology, Pusan National University, Busan 609-735 (Korea, Republic of); Shim, Yoon-Bo, E-mail: ybshim@pusan.ac.kr [Department of Chemistry and Center for Innovative BioPhysio Sensor Technology, Pusan National University, Busan 609-735 (Korea, Republic of)

    2009-09-21

    A selective detection method for dopamine (DA) was developed by incorporating cibacron blue (F3GA) into poly-1,5-diaminonaphthalene (PDAN) layer. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and cyclic voltammetry (CV) were employed to characterize the modified surfaces. The modified electrode was effective in selectively facilitating the electron transfer of DA and blocking the interferences of negatively charged species attributed to the sulfonate groups in the F3GA/PDAN composite film. This method enabled the determination of DA in the presence of various interfering species, including ascorbic acid (AA), in a phosphate buffer solution (pH 7.4). The modified electrode demonstrated good performance in the detection of DA in a concentration range of 5.0-100 {mu}M, with a detection limit (k = 3) of 0.1 {+-} 0.01 {mu}M. The application was conducted for the determination of DA in a human urine sample and the sensor was proven to be rapid, has excellent selectivity, and stable amperometric response.

  18. Correlation structure and variable selection in generalized estimating equations via composite likelihood information criteria.

    Science.gov (United States)

    Nikoloulopoulos, Aristidis K

    2016-06-30

    The method of generalized estimating equations (GEE) is popular in the biostatistics literature for analyzing longitudinal binary and count data. It assumes a generalized linear model for the outcome variable, and a working correlation among repeated measurements. In this paper, we introduce a viable competitor: the weighted scores method for generalized linear model margins. We weight the univariate score equations using a working discretized multivariate normal model that is a proper multivariate model. Because the weighted scores method is a parametric method based on likelihood, we propose composite likelihood information criteria as an intermediate step for model selection. The same criteria can be used for both correlation structure and variable selection. Simulations studies and the application example show that our method outperforms other existing model selection methods in GEE. From the example, it can be seen that our methods not only improve on GEE in terms of interpretability and efficiency but also can change the inferential conclusions with respect to GEE. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  19. GRAFT COPOLYMERIZATION OF OLYGOESTERACRYLATES WITH LIQUID RUBBER AND COPOLYMER’S CHARACTERISTICS

    Directory of Open Access Journals (Sweden)

    Y. A. Anisimov

    2015-02-01

    Full Text Available The kinetic of graft copolymerization of threeethyleneglicoldimethacrylate and di threeethyleneglicolftalatedimethacrylate with liquid buthadiene rubber have been studied as a function of the olygomers composition. The experimental constants of copolymerization rate and efficiency olygoesteracrylates graft to liquid rubber were determined. The ihfluence of olygoesteracrylates’ nature on the grafting efficiency to olygomer rubber is determined and the strength characteristics are found.

  20. Produtividade e composição físico-química de bagas de cultivares de uva em distintos porta-enxertos Productivity and physicochemical composition of berries of grapevine cultivars grafted onto different rootstocks

    Directory of Open Access Journals (Sweden)

    Renata Vieira da Mota

    2009-06-01

    Full Text Available O objetivo deste trabalho foi avaliar a influência de nove porta-enxertos na produção e composição química das bagas de uvas de mesa e de processamento durante o período de 2006 a 2008 em Caldas, MG. As cultivares Niágara Rosada e Folha de Figo foram enxertadas sobre 'IAC 572', 'IAC 313', 'IAC 766', '420 A', '1103 Paulsen', 'Traviú', '196-17', 'Gravesac' e 'RR 101-14' e submetidas ao delineamento em blocos ao acaso com dez tratamentos (nove porta-enxertos e o pé-franco e quatro repetições. Ambas cultivares apresentaram maior produção sobre 'IAC 572', porém com prejuízo para a qualidade das bagas que apresentaram menor relação sólidos solúveis/acidez, menor teor de antocianinas e de compostos fenólicos e maior acidez. A absorção de potássio foi mais dependente do porta-enxerto em 'Niágara Rosada'; a maior absorção foi com os porta-enxertos 'IAC 766' e 'Traviú'. Videiras enxertadas sobre '196-17' apresentaram o menor teor de potássio nas bagas. 'Niágara Rosada' apresentou produção de 9 kg por planta e elevada relação sólidos solúveis/acidez sobre 'RR 101-14', '420 A' e 'Gravesac'. Entretanto, 'Gravesac' proporcionou maior concentração de antocianinas. 'Folha de Figo' enxertada em '196-17' apresentou elevado teor de sólidos solúveis, antocianinas e fenólicos nas cascas e menor teor de acidez e fenólicos nas sementes, além de produção de 5 kg por planta, estatisticamente semelhante aos porta-enxertos mais produtivos.This work aimed at evaluating the influence of nine rootstocks on the productivity and chemical composition of table and processing grapes from 2006 to 2008 in Caldas, MG. The cultivars Niagara Rosada and Folha de Figo were grafted onto 'IAC 572', 'IAC 313', 'IAC 766', '420 A', '1103 Paulsen', 'Traviú', '196-17', 'Gravesac' and 'RR 101-14' and submitted to a randomized block design with ten treatments (nine rootstocks and ungrafted plant with four replicates. Both cultivars had higher yields

  1. Osseous scintigraphy and auxiliary graft

    International Nuclear Information System (INIS)

    Khelifa, F.; Siles, S.; Puech, B.

    1992-01-01

    The scintigraphy could be a good way to survey the osseous graft: three cases are studied in which were recognized the presence of a graft, surinfection, graft lysis, pseudo-arthrosis, algodystrophy. 8 refs., 5 figs

  2. Meniscal allograft transplantation. Part 1: systematic review of graft biology, graft shrinkage, graft extrusion, graft sizing, and graft fixation.

    Science.gov (United States)

    Samitier, Gonzalo; Alentorn-Geli, Eduard; Taylor, Dean C; Rill, Brian; Lock, Terrence; Moutzouros, Vasilius; Kolowich, Patricia

    2015-01-01

    To provide a systematic review of the literature regarding five topics in meniscal allograft transplantation: graft biology, shrinkage, extrusion, sizing, and fixation. A systematic literature search was conducted using the PubMed (MEDLINE), ScienceDirect, and EBSCO-CINAHL databases. Articles were classified only in one topic, but information contained could be reported into other topics. Information was classified according to type of study (animal, in vitro human, and in vivo human) and level of evidence (for in vivo human studies). Sixty-two studies were finally included: 30 biology, 3 graft shrinkage, 11 graft extrusion, 17 graft size, and 6 graft fixation (some studies were categorized in more than one topic). These studies corresponded to 22 animal studies, 22 in vitro human studies, and 23 in vivo human studies (7 level II, 10 level III, and 6 level IV). The principal conclusions were as follows: (a) Donor cells decrease after MAT and grafts are repopulated with host cells form synovium; (b) graft preservation alters collagen network (deep freezing) and causes cell apoptosis with loss of viable cells (cryopreservation); (c) graft shrinkage occurs mainly in lyophilized and gamma-irradiated grafts (less with cryopreservation); (d) graft extrusion is common but has no clinical/functional implications; (e) overall, MRI is not superior to plain radiograph for graft sizing; (f) graft width size matching is more important than length size matching; (g) height appears to be the most important factor influencing meniscal size; (h) bone fixation better restores contact mechanics than suture fixation, but there are no differences for pullout strength or functional results; and (i) suture fixation has more risk of graft extrusion compared to bone fixation. Systematic review of level II-IV studies, Level IV.

  3. Odor composition analysis and odor indicator selection during sewage sludge composting

    Science.gov (United States)

    Zhu, Yan-li; Zheng, Guo-di; Gao, Ding; Chen, Tong-bin; Wu, Fang-kun; Niu, Ming-jie; Zou, Ke-hua

    2016-01-01

    ABSTRACT On the basis of total temperature increase, normal dehydration, and maturity, the odor compositions of surface and internal piles in a well-run sewage sludge compost plant were analyzed using gas chromatography–mass spectrometry with a liquid nitrogen cooling system and a portable odor detector. Approximately 80 types of substances were detected, including 2 volatile inorganic compounds, 4 sulfur organic compounds, 16 benzenes, 27 alkanes, 15 alkenes, and 19 halogenated compounds. Most pollutants were mainly produced in the mesophilic and pre-thermophilic periods. The sulfur volatile organic compounds contributed significantly to odor and should be controlled primarily. Treatment strategies should be based on the properties of sulfur organic compounds. Hydrogen sulfide, methyl mercaptan, dimethyl disulfide, dimethyl sulfide, ammonia, and carbon disulfide were selected as core indicators. Ammonia, hydrogen sulfide, carbon disulfide, dimethyl disulfide, methyl mercaptan, dimethylbenzene, phenylpropane, and isopentane were designated as concentration indicators. Benzene, m-xylene, p-xylene, dimethylbenzene, dichloromethane, toluene, chlorobenzene, trichloromethane, carbon tetrachloride, and ethylbenzene were selected as health indicators. According to the principle of odor pollution indicator selection, dimethyl disulfide was selected as an odor pollution indicator of sewage sludge composting. Monitoring dimethyl disulfide provides a highly scientific method for modeling and evaluating odor pollution from sewage sludge composting facilities. Implications: Composting is one of the most important methods for sewage sludge treatment and improving the low organic matter content of many agricultural soils. However, odors are inevitably produced during the composting process. Understanding the production and emission patterns of odors is important for odor control and treatment. Core indicators, concentration indicators, and health indicators provide an index

  4. Harvesting polysulfides by sealing the sulfur electrode in a composite ion-selective net

    Science.gov (United States)

    Chen, Yazhou; Li, Zhong; Li, Xuekui; Zeng, Danli; Xu, Guodong; Zhang, Yunfeng; Sun, Yubao; Ke, Hanzhong; Cheng, Hansong

    2017-11-01

    A cathode was prepared by sealing a carbon supported sulfur electrode inside a composite ion-selective net made of carbon, binder and lithiated ionomer to restrict shuttling of polysulfide anionic species. As a result, the soluble polysulfide anions become unable to escape from the composite ion-selective films due to the electrostatic repulsion between the immobilized single ion conducting ionomers and the polysulfides with no dead angles. Experimentally, lithiated 4,4‧-difluoro bis(benzene sulfonyl)imide and PEG200 were copolymerized to form a polyether based single ion conducting polymer. The ionic conductivity of the blend film made of ionomer and poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) at a mass ratio of 1:1 is 0.57 mS cm-1 at room temperature. The battery capacity with the sealed sulfur electrode is 1412 mAh g-1 at 0.5 C, 1041 mAh g-1 at 1.0 C, 873 mAh g-1 at 2.0 C and 614 mAh g-1 at 5.0 C, significantly better than the results with lithiated Nafion especially at high C rates. In addition, a long cycling test at 2 C for 500 cycles gives rise to a stable capacity of 800 mAh g-1. The intrinsic electrostatic repulsion between polysulfide anions and the negatively charged electrolyte film, together with the overall sealed electrode configuration, is responsible for blocking the shuttling of polysulfides effectively.

  5. Heterogeneous Configuration of a Ag Nanowire/Polymer Composite Structure for Selectively Stretchable Transparent Electrodes.

    Science.gov (United States)

    Kim, Youngmin; Jun, Sungwoo; Ju, Byeong-Kwon; Kim, Jong-Woong

    2017-03-01

    One of the most important aspects that we need to consider in the design of intrinsically stretchable electrodes is that most electronic devices that can be formed on them are not stretchable themselves. This discrepancy can induce severe stress singularities at the interfaces between stiff devices and stretchable electrodes, leading to catastrophic device delamination when the substrate is stretched. Here, we suggest a novel solution to this challenge which involves introducing a photolithography-based rigid-island approach to fabricate the heterogeneous configuration of a silver nanowire (AgNW)/polymer composite structure. For this, we designed two new transparent polymers: a photopatternable polymer that is rigid yet flexible, and a stretchable polymer, both of which have identical acrylate functional groups. Patterning of the rigid polymer and subsequent overcoating of the soft polymer formed rigid island disks embedded in the soft polymer, resulting in a selectively stretchable transparent film. Strong covalent bonds instead of weak physical interactions between the polymers strengthened the cohesive force at the interface of the rigid/soft polymers. Inverted-layer processing with a percolated AgNW network was used to form a heterogeneous AgNW/polymer composite structure that can be used as a selectively stretchable transparent electrode. An optimized structural configuration prevented the resistance of the rigid electrode from varying up to a lateral strain of 70%. A repeated stretch/release test with 60% strain for 5000 cycles did not cause any severe damage to the structure, revealing that the fabricated structure was mechanically stable and reliable.

  6. Manufacturing Process Selection of Composite Bicycle’s Crank Arm using Analytical Hierarchy Process (AHP)

    Science.gov (United States)

    Luqman, M.; Rosli, M. U.; Khor, C. Y.; Zambree, Shayfull; Jahidi, H.

    2018-03-01

    Crank arm is one of the important parts in a bicycle that is an expensive product due to the high cost of material and production process. This research is aimed to investigate the potential type of manufacturing process to fabricate composite bicycle crank arm and to describe an approach based on analytical hierarchy process (AHP) that assists decision makers or manufacturing engineers in determining the most suitable process to be employed in manufacturing of composite bicycle crank arm at the early stage of the product development process to reduce the production cost. There are four types of processes were considered, namely resin transfer molding (RTM), compression molding (CM), vacuum bag molding and filament winding (FW). The analysis ranks these four types of process for its suitability in the manufacturing of bicycle crank arm based on five main selection factors and 10 sub factors. Determining the right manufacturing process was performed based on AHP process steps. Consistency test was performed to make sure the judgements are consistent during the comparison. The results indicated that the compression molding was the most appropriate manufacturing process because it has the highest value (33.6%) among the other manufacturing processes.

  7. Selection of grapevine leaf varieties for culinary process based on phytochemical composition and antioxidant properties.

    Science.gov (United States)

    Lima, Adriano; Bento, Albino; Baraldi, Ilton; Malheiro, Ricardo

    2016-12-01

    Grapevine leaves are an abundant sub-product of vineyards which is devalued in many regions. The objective of this work is to study the antioxidant activity and phytochemical composition of ten grapevine leaf varieties (four red varieties: Tinta Amarela, Tinta Roriz, Touriga Franca, and Touriga Nacional; and six white varieties: Côdega do Larinho, Fernão Pires, Gouveio, Malvasia Fina, Rabigato, and Viosinho) to select varieties to be used as food ingredients. White grapevine leaves revealed higher antioxidant potential. Malvasia Fina reported better antioxidant properties contrasting with Touriga Franca. Phenolic content varied between 112 and 150mgGAEg(-1) of extract (gallic acid equivalents), hydroxycinnamic acid derivatives and flavonols varied between 76 and 108mgCAEg(-1) of extract (caffeic acid equivalents) and 39 and 54mgQEg(-1) of extract (quercetin equivalents). Malvasia Fina is a good candidate for culinary treatment due to its antioxidant properties and composition in bioactive compounds. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Effect of selective logging on floristic and structural composition in a forest fragment from Amazon Biome

    Directory of Open Access Journals (Sweden)

    Karen Janones da Rocha

    2017-04-01

    Full Text Available This study was conducted in one region of a Seasonal Semideciduous Forest located in Tapurah (Mato Grosso State, Brazil with the aim of studying its floristic and structural composition. The fixed area method was applied to 10 × 250 m clusters, allocating and measuring five clusters with five subunits of 500 m² each. Species with a diameter at breast height greater than or equal to 10 cm were considered, and the sample sufficiency of the floristic survey was verified by a species accumulation curve. The similarities between the sample subunits were calculated by the Jaccard Similarity Index, and the species diversity with the Shannon Diversity Index and Pielou Evenness Index. The horizontal vegetation structure was characterized by density, frequency, dominance and the values of ecological importance, and diametric distribution were assessed by the Spiegel procedure. The families Vochysiaceae, Fabaceae and Sapindaceae were highly represented, and Qualea paraensis, Aspidosperma discolor and Matayba arborescens were the most important species. A high diversity and low ecological dominance were found, and the diametric structure of the trees presented a negative exponential distribution. In general, the structure, floristic composition and richness of vegetation correspond to a forest with stable and autoregenerative community after selective logging.

  9. Essential oil composition and nutrient analysis of selected medicinal plants in Sultanate of Oman

    Directory of Open Access Journals (Sweden)

    Javid Hussain

    2013-12-01

    Full Text Available Objective: To evaluate the nutrients and essential oils of five medicinal plants, Juniperus excelsa (J. excelsa, Dodonaea viscosa, Euryops pinifolius, Teucrium polium (T. polium, and Helianthemum lippii that were collected from Jabal Al Akhdar, Oman. Methods: Proximate parameters (moisture, dry matter, ash, crude fats, proteins, fibers, nitrogen, carbohydrates, and energy values and nutrient analysis (K, Na, Ca, Fe, P, Mg etc. were evaluated in the five medicinal plants using standard techniques. On the basis of these analysis, T. polium and J. excels were selected for essential oil analysis using a rapid solvent-free microwave extraction method and GC-MS. Results: The results showed that leaves of J. excelsa had highest proportion of crude fats, fibers and energy value while ash was highest in T. polium. J. excelsa was also rich in essential minerals such as calcium, magnesium, potassium and iron while the trace elements and heavy metals composition was marginal. A rapid solvent-free microwave extraction method to extract oil from medicinal plants species showed that only T. polium and J. excelsa yielded oil. The chemical composition of essential oils showed higher proportion of delta-3-carene, limonene, β-eudesmol, ledeneoxide (II, α-trans-bergamatene, linalyl acetate and germacrene. Conclusions: J. excelsa and T. polium are a good source of proximate, minerals and essential oils, which can be considered for healthy life besides their medicinal values.

  10. Bond strength of selected composite resin-cements to zirconium-oxide ceramic

    Science.gov (United States)

    Fons-Font, Antonio; Amigó-Borrás, Vicente; Granell-Ruiz, María; Busquets-Mataix, David; Panadero, Rubén A.; Solá-Ruiz, Maria F.

    2013-01-01

    Objectives: The aim of this study was to evaluate bond strengths of zirconium-oxide (zirconia) ceramic and a selection of different composite resin cements. Study Design: 130 Lava TM cylinders were fabricated. The cylinders were sandblasted with 80 µm aluminium oxide or silica coated with CoJet Sand. Silane, and bonding agent and/or Clearfil Ceramic Primer were applied. One hundred thirty composite cement cylinders, comprising two dual-polymerizing (Variolink II and Panavia F) and two autopolymerizing (Rely X and Multilink) resins were bonded to the ceramic samples. A shear test was conducted, followed by an optical microscopy study to identify the location and type of failure, an electron microscopy study (SEM and TEM) and statistical analysis using the Kruskal-Wallis test for more than two independent samples and Mann-Whitney for two independent samples. Given the large number of combinations, Bonferroni correction was applied (α=0.001). Results: Dual-polymerizing cements provided better adhesion values (11.7 MPa) than the autopolymerizing (7.47 MPa) (p-value M-Wceramic) was produced at a lesser force than cohesive failure (fracture of cement) (p-value M-Wceramic, creating a more rough and retentive surface, thus providing an improved micromechanical interlocking between the cement and the ceramic. Key words:Shear bond strength, silica coating, surface treatment, zirconia ceramics, phosphate monomer. PMID:22926485

  11. Cambial Isoperoxidases Related to Graft Compatibility in Pear-Quince Graft Combinations

    OpenAIRE

    GÜLEN*, Hatice

    2005-01-01

    This study was initiated to survey the graft compatibility characteristics of some selected quince clones known as "S.Ö." with regard to isoperoxidase markers. Compatible (Beurre Hardy = BH) and incompatible (Bartlett = BT) pear cultivars were grafted on quince A (QA) and 13 S.Ö. quince clones by T budding. Bark tissues were collected from the union (4, 8 and 12 weeks after grafting) and from unbudded rootstocks in addition to current-year shoots of 2 pear scions to investigate 2 an...

  12. Intensifying radiation induced grafting of 4-vinylpyridine/glycidyl methacrylate mixtures onto poly(ethylene-co-tetrafluoroethylene) films using ultrasound

    International Nuclear Information System (INIS)

    Nasef, Mohamed Mahmoud; Sithambaranathan, Paveswari; Ahmad, Arshad; Abouzari-lotf, Ebrahim

    2017-01-01

    A new ultrasound-aided method was used to enhance grafting of 4-vinylpyridine (4-VP) and glycidyl methacrylate (GMA) monomers mixtures onto electron beam (EB) irradiated poly(ethylene-co-tetrafluoroethylene) (ETFE) film for the first time. The effects of reaction parameters such as absorbed dose, monomer concentration, reaction time on both of degree of grafting (DG) and grafting efficiency (GE) were investigated under sonication and conventional grafting at similar temperatures. Fourier transform infrared (FTIR) and atomic force microscopy (AFM) were used to monitor the impact of the applied ultrasound on composition and surfaces of the grafted films whereas 1 H-NMR was used to investigate composition of the grafting residues. The ultrasound-aided grafting of 4-VP/GMA was found to enhance both of DG% and GE remarkably. Moreover, it produced grafted ETFE films having smoother surfaces without homopolymer contamination compared to grafted films obtained from conventional grafting. The results of this study suggest that the use of ultrasound is a promising way for intensifying grafting process and improving its economy. - Highlights: • Grafting of 4-VP/GMA onto ETFE films was carried out with the aid of ultrasound. • Degree of grafting was found to be strongly dependent on reaction parameters. • Sonication remarkably enhanced the reaction kinetics and grafting efficiency. • Grafted films with smoother surfaces without homopolymer contamination were obtained. • Ultrasound aided grafting is superior to conventional one and promotes intensification.

  13. Heavy Metal Removal by Chitosan and Chitosan Composite

    International Nuclear Information System (INIS)

    Abdel-Mohdy, F.A.; El-Sawy, S.; Ibrahim, M.S.

    2005-01-01

    Radiation grafting of diethyl aminoethyl methacrylate (DEAEMA) on chitosan to impart ion exchange properties and to be used for the separation of metal ions from waste water, was carried out. The effect of experimental conditions such as monomer concentration and the radiation dose on grafting were studied. On using chitosan, grafted chitosan and some chitosan composites in metal ion removal they show high up-take capacity for Cu 2+ and lower uptake capacities for the other divalent metal ions used (Zn and Co). Competitive study, performed with solutions containing mixture of metal salts, showed high selectivity for Cu 2+ than the other metal ion. Limited grafting of DEAEMA polymer -containing specific functional groups-onto the chitosan backbone improves the sorption performance

  14. Cartilage grafting in facial reconstruction with special consideration of irradiated grafts

    International Nuclear Information System (INIS)

    Donald, P.J.

    1986-01-01

    The search for the perfect facial implant for reconstruction of the face continues. Cartilage, once thought to be an undesirable graft material because of its propensity for absorption, has regained popularity in the past decade. Various preparation techniques have been employed to ensure graft sterility and diminished absorption. An improved understanding of cartilage structure and physiology has shed considerable light on the host-graft relationship. Gamma irradiation is a time-honored method of preservation. An experiment was undertaken to investigate the physiology of irradiated cartilage grafts following prolonged implantation on the facial skeleton of sheep and dog. Merthiolate preserved grafts were used as controls. Direct observation, histochemical techniques, autoradiography, and transmission electron micrography were used to determine chondrocyte viability and matrix composition. It was surprising to note that following implantation of 16 to 72 months, complete resorption was seen in 87.7% of the irradiated grafts and in 43.8% of the Merthiolate stored controls. Many of the grafts acquired chondrocytes from the host and produced new proteoglycan matrix as well as undergoing some degree of ossification. A comparison to the clinical situation in humans is made. 98 references

  15. Calcar bone graft

    Energy Technology Data Exchange (ETDEWEB)

    Bargar, W.L.; Paul, H.A.; Merritt, K.; Sharkey, N.

    1986-01-01

    A canine model was developed to investigate the use of an autogeneic iliac bone graft to treat the calcar deficiency commonly found at the time of revision surgery for femoral component loosening. Five large male mixed-breed dogs had bilateral total hip arthroplasty staged at three-month intervals, and were sacrificed at six months. Prior to cementing the femoral component, an experimental calcar defect was made, and a bicortical iliac bone graft was fashioned to fill the defect. Serial roentgenograms showed the grafts had united with no resorption. Technetium-99 bone scans showed more uptake at three months than at six months in the graft region. Disulfine blue injection indicated all grafts were perfused at both three and six months. Thin section histology, fluorochromes, and microradiographs confirmed graft viability in all dogs. Semiquantitative grading of the fluorochromes indicated new bone deposition in 20%-50% of each graft at three months and 50%-80% at six months. Although the calcar bone graft was uniformly successful in this canine study, the clinical application of this technique should be evaluated by long-term results in humans.

  16. Patency rates and complications of Exxcel yarn-wrapped polytetrafluoroethylene grafts versus Gore-tex stretch polytetrafluoroethylene grafts: a prospective study.

    Science.gov (United States)

    Ko, Po-Jen; Hsieh, Hung-Chang; Chu, Jaw-Ji; Lin, Pyng Jing; Liu, Yun-Hen

    2004-01-01

    Polytetrafluoroethylene (PTFE) has long been used for hemodialysis access when there is no suitable superficial vein. We conducted a prospective randomized study to compare two PTFE grafts; the stretch Gore-tex graft and the Exxcel graft. Between May 2000 and February 2001, PTFE grafts were implanted for hemodialysis access in the upper extremities of 94 consecutive patients with end-stage renal disease. Graft selection was randomized, with patients receiving either a Gore-tex or an Exxcel graft. All grafts were monitored for signs of thrombosis or other complications. Graft survival was analyzed using a life-table analysis and the log-rank test was applied to compare graft patency. The primary patency rates 1 and 2 years after implantation were 51% and 36% for the Exxcel grafts, and 71% and 45% for the Gore-tex grafts, respectively. The difference between the two groups was not significant at any time. The incidence of complications needing further surgical management was 8.2% in the Exxcel group and 6.7% in the Gore-tex group, without a significant difference. Exxcel grafts or Gore-tex stretch grafts can be used for dialysis access with similar expected outcomes for up to 2 years, despite the differences in their outer surface design. The yarn-wrapped design does not appear to enhance the graft patency and we found no remarkable difference.

  17. Phytochemical composition and in vitro anti-tumour activities of selected tomato varieties.

    Science.gov (United States)

    Ramos-Bueno, Rebeca P; Romero-González, Roberto; González-Fernández, María J; Guil-Guerrero, José L

    2017-01-01

    Previous studies indicated that tomato is a rich source of phytochemicals that act on different tumours. In this research, the phytochemical composition of selected tomato varieties was assessed by GLC and UHPLC/HPLC-MS, as well as their anti-tumour activities on HT-29 colorectal cancer cells. Significant differences were found among tomato varieties; lycopene was high in Racimo, phenolics in Pera, sterols in Cherry, and linoleic acid predominated in all varieties. The MTT and LDH assays showed significant time- and concentration-dependent inhibitory/cytotoxic effects of all tomato varieties on HT-29 cells. Furthermore, the joint addition of tomato carotenoids and olive oil to HT-29 cell cultures induced inhibitory effects significantly higher than those obtained from each of them acting separately, while no actions were exercised in CCD-18 normal cells. Tomato fruits constitute a healthy source of phytochemicals, although differences exist among varieties. In vitro, all of them inhibit colorectal cancer cell proliferation with Racimo variety at the top, and exercising a selective action on cancer cells by considering the lack of effects on CCD-18 cells. Furthermore, synergy was observed between olive oil and tomato carotenoids in inhibiting HT-29 cancer cell proliferation; conversely, phenolics showed no significant effects and hindered carotenoids actions. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  18. Influence of temperature and chemical composition on phase transformations of selected oxide melts

    Directory of Open Access Journals (Sweden)

    J. Dobrovská

    2013-07-01

    Full Text Available The paper deals with structural changes of solid phase of selected oxide systems during their transition into liquid state. Analyses concerned poly-component systems forming basis of casting powders for CCM mould. Industrially used oxide system with prevailing contents of CaO–Al2O3–SiO2 components and with numerous accompanying admixtures was tested. Investigation was focused on temperatures, during which individual phases disappear and precipitate, as well as on influence of CaO content on phase composition at selected temperatures. The experiments were realised with use of original methodology consisting of shock cooling of the tested melt in liquid nitrogen. Thus obtained samples were further investigated by X-ray diffraction phase analyses at ambient temperatures. The obtained results provide additional data on physical-chemical properties of oxide systems, such as surface tension, viscosity, sintering intervals, etc., which can be used in technological practice for appropriate lubrication effect of casting powders in the mould.

  19. Differential Pulse Voltammetric Determination of Selected Nitro-Compounds on Silver, Solid Silver Composite, and Solid Graphite Composite Electrodes

    Czech Academy of Sciences Publication Activity Database

    Navrátil, Tomáš; Barek, J.; Fašinová-Šebková, S.

    2009-01-01

    Roč. 21, 3-5 (2009), s. 309-315 ISSN 1040-0397 R&D Projects: GA ČR GA203/07/1195; GA AV ČR IAA400400806 Institutional research plan: CEZ:AV0Z40400503 Keywords : silver electrode * silver composite electrode * graphite composite electrode * differential pulse voltammetry Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.630, year: 2009

  20. Radiation-induced grafting of sweet sorghum stalk for copper(II) removal from aqueous solution

    International Nuclear Information System (INIS)

    Dong, Jing; Hu, Jun; Wang, Jianlong

    2013-01-01

    Highlights: • Radiation-induced grafting was used to modify the stalk. • Cellulose, hemicellulose and lignin participated in grafting reaction. • Both the structure and composition of stalk had influence on grafting. • The sorption capacity of the grafted stalk increased about five times. -- Abstract: The influence of main components (cellulose, hemicellulose and lignin) of the sweet sorghum stalk on radiation-induced grafting reaction and adsorption of copper from aqueous solution was investigated. Sweet sorghum stalk was grafted with acrylic acid induced by γ-irradiation. The results showed that the grafted stalk contained 1.6 mmol/g carboxyl groups, and its maximal adsorption capacity was 13.32 mg/g. The cellulose, hemicellulose and lignin of the raw materials were confirmed to involve in grafting reaction through comparing the grafting yield and the structure of the grafted materials. Both the structure and the composition of the sweet sorghum stalk had influence on the grafting reaction and adsorption capacity. The adsorption capacity of the grafted sweet sorghum stalk increased about five times, and the adsorption isotherm of the grafted materials conformed to the Langmuir model. The main mechanism for copper adsorption involved in ion exchange

  1. Long-term results of PTFE grafts.

    Science.gov (United States)

    Hedin, Ulf

    2015-01-01

    Vascular surgeons are essential in "lifeline" creation for hemodialysis patients and should be the central player in any multidisciplinary access service together with nephrologists, dialysis staff and interventional radiology. In this position, access surgeons are involved in complicated clinical decision making regarding primary and secondary access selection, which throughout the last decade has been largely aided, and influenced, by national and international guidelines as well as other initiatives. These recommendations, unanimously and appropriately, advocate the placement of native fistulas over synthetic grafts (the majority grafts from expanded polytetrafluoroethylene, ePTFE, herein referred to as PTFE) based on the superiority of fistulas with respect to complications such as infections and thrombosis. Nevertheless, the use of PTFE grafts for hemodialysis access is an accepted and firmly established alternative to native fistulas where data today reveal unwanted consequences to overinterpretation of established guidelines such as increased catheter use. This information highlights a need for an adjustment of access selection strategies based on patient-centered algorithms. Here, available results on PTFE graft performance in hemodialysis access is recapitulated, with respect to both conventional grafts and technical modifications, and conclude with a modified approach to primary access selection.

  2. Outer-selective thin film composite (TFC) hollow fiber membranes for osmotic power generation

    KAUST Repository

    Le, Ngoc Lieu

    2016-01-14

    The pressure-retarded osmosis (PRO) process is a green technique for power generation to respond the world\\'s need of energy sustainability. In this study, we have developed the vital component of the process, i.e. membrane, in the configuration of the outer-selective thin-film composite (TFC) hollow fiber, which is more practical than other configurations in the real applications. The support layer morphology and the formation of the selective polyamide layer have been optimized for a good PRO performance. The results show that the bore fluid with higher amount of the solvent N-methyl-2-pyrrolidone leads to full finger-like hollow fibers, which provide higher flux but lower pressure tolerance. The addition of higher amount of diethylene glycol into the dope solution, improves the pore formation and suppresses the macrovoid formation, while properly lowering the take-up speed increases their wall thickness and pressure tolerance. A simple alcohol-pre-wetting approach on the fiber support leads to a smooth and thin polyamide layer, which is favorable for a high water flux and power density. Its efficiency follows this order: n-propanol>ethanol>methanol>water. The n-propanol pre-wetted TFC membrane can tolerate 17 bar with a peak power density of 9.59 W/m2 at room temperature, using 1 M NaCl solution as the draw solution and DI water as feed. This work demonstrates the potential of outer-selective TFC hollow fiber membranes for energy conversion via PRO process, provides useful database to fabricate suitable support morphology and raise a simple technique to practically form a thin and smooth polyamide layer.

  3. SLA-constrained service selection for minimizing costs of providing composite cloud services under stochastic runtime performance.

    Science.gov (United States)

    Huang, Kuo-Chan; Tsai, Mu-Jung; Lu, Sin-Ji; Hung, Chun-Hao

    2016-01-01

    Composite cloud services based on the methodologies of Software as a Service and Service-Oriented Architecture are transforming how people develop and use software. Cloud service providers are confronting the service selection problem when composing composite cloud services. This paper deals with an important type of service selection problem, minimizing the total cost of providing a composite cloud service with respect to the constraints of service level agreement (SLA). Two types of SLA are considered in the study: per-request-based SLA and ratio-based SLA. We present three service selection approaches for dynamic cloud environments where services' performance might vary with time. The first two are iterative compound approaches for per-request-based SLA and the third approach is a one-step method for ratio-based SLA based on the Chebyshev's theorem and nonlinear programming. Experimental results show that our approaches outperform the previous method significantly in terms of total cost reduction.

  4. Comparison of cartilage graft and fascia in type 1 tympanoplasty: systematic review and meta-analysis.

    Science.gov (United States)

    Yang, Tao; Wu, Xuewen; Peng, Xiaofei; Zhang, Yanni; Xie, Shaobing; Sun, Hong

    2016-11-01

    Tympanoplasty using cartilage grafts has a better graft take rate than that using temporalis fascia grafts. There are no significant differences between cartilage grafts and temporalis fascia grafts for hearing outcomes. Contrary to the sliced cartilage sub-group, full-thickness cartilage grafts generate better hearing outcomes than temporalis fascia grafts. Tympanic membrane perforation can cause middle ear relapsing infection and lead to hearing damage. Various techniques have been applied in order to reconstruct the tympanic membrane. Recently, cartilage grafts and temporalis fascia grafts have been widely used for tympanic membrane closure. A systemic review and meta-analysis was carried out based on published retrospective trials that investigated the efficacy of cartilage grafts and temporalis fascia grafts in type 1 tympanoplasty. Both graft take rates and mean AIR-BONE-GAP gains were analyzed. Cochrane Library, PubMed, and Embase were systematically searched. After a scientific investigation, we extracted the relevant data following our selection criteria. Odds ratio (OR) of graft take rates and mean difference (MD) of AIR-BONE-GAP gains were calculated within 95% confidence intervals. Eight eligible articles with 915 patients were reviewed. The pooled OR for graft take rate was 3.11 (95% CI =1.94-5.00; p = 0.43) and the difference between the two groups was significant, which means that the cartilage grafts group got a better graft take rate than the temporalis fascia grafts group. The pooled MD for mean AIR-BONE-GAP gain was 1.92 (95% CI = -0.12-3.95; p fascia grafts group. On the contrary, the pooled MD of sliced cartilage grafts sub-group was 0.12 (95% CI = -0.44-0.69; p = 0.61) and there was no significant difference between the sliced cartilage grafts and temporalis fascia group.

  5. Bio-active glass air-abrasion has the potential to remove resin composite restorative material selectively

    International Nuclear Information System (INIS)

    Milly, Hussam; Andiappan, Manoharan; Thompson, Ian; Banerjee, Avijit

    2014-01-01

    The aims of this study were to assess: (a) the chemistry, morphology and bioactivity of bio-active glass (BAG) air-abrasive powder, (b) the effect of three air-abrasion operating parameters: air pressure, powder flow rate (PFR) and the abrasive powder itself, on the selective removal of resin composite and (c) the required “time taken”. BAG abrasive particles were characterised using scanning electron microscopy-energy dispersive X-ray spectrometry (SEM-EDX) and Fourier-transform infrared spectroscopy (FTIR). Standardised resin composite restorations created within an enamel analogue block (Macor™) in vitro, were removed using air-abrasion undersimulated clinical conditions. 90 standardised cavities were scanned before and after resin composite removal using laser profilometry and the volume of the resulting 3D images calculated. Multilevel linear model was used to identify the significant factors affecting Macor™ removal. BAG powder removed resin composite more selectively than conventional air-abrasion alumina powder using the same operating parameters (p < 0.001) and the effect of altering the unit's operating parameters was significant (p < 0.001). In conclusion, BAG powder is more efficient than alumina in the selective removal of resin composite particularly under specific operating parameters, and therefore may be recommended clinically as a method of preserving sound enamel structure when repairing and removing defective resin composite restorations.

  6. Bio-active glass air-abrasion has the potential to remove resin composite restorative material selectively

    Energy Technology Data Exchange (ETDEWEB)

    Milly, Hussam [Biomaterials, Biomimetics and Biophotonics Research Group, Kings College London Dental Institute at Guy' s Hospital, King' s Health Partners, London (United Kingdom); Andiappan, Manoharan [Unit of Dental Public Health, Kings College London Dental Institute at Guy' s Hospital, King' s Health Partners, London (United Kingdom); Thompson, Ian [Biomaterials, Biomimetics and Biophotonics Research Group, Kings College London Dental Institute at Guy' s Hospital, King' s Health Partners, London (United Kingdom); Banerjee, Avijit, E-mail: avijit.banerjee@kcl.ac.uk [Biomaterials, Biomimetics and Biophotonics Research Group, Kings College London Dental Institute at Guy' s Hospital, King' s Health Partners, London (United Kingdom); Unit of Conservative Dentistry, King' s College London Dental Institute at Guy' s Hospital, King' s Health Partners, London (United Kingdom)

    2014-06-01

    The aims of this study were to assess: (a) the chemistry, morphology and bioactivity of bio-active glass (BAG) air-abrasive powder, (b) the effect of three air-abrasion operating parameters: air pressure, powder flow rate (PFR) and the abrasive powder itself, on the selective removal of resin composite and (c) the required “time taken”. BAG abrasive particles were characterised using scanning electron microscopy-energy dispersive X-ray spectrometry (SEM-EDX) and Fourier-transform infrared spectroscopy (FTIR). Standardised resin composite restorations created within an enamel analogue block (Macor™) in vitro, were removed using air-abrasion undersimulated clinical conditions. 90 standardised cavities were scanned before and after resin composite removal using laser profilometry and the volume of the resulting 3D images calculated. Multilevel linear model was used to identify the significant factors affecting Macor™ removal. BAG powder removed resin composite more selectively than conventional air-abrasion alumina powder using the same operating parameters (p < 0.001) and the effect of altering the unit's operating parameters was significant (p < 0.001). In conclusion, BAG powder is more efficient than alumina in the selective removal of resin composite particularly under specific operating parameters, and therefore may be recommended clinically as a method of preserving sound enamel structure when repairing and removing defective resin composite restorations.

  7. Thermal behavior and densification mechanism during selective laser melting of copper matrix composites: Simulation and experiments

    International Nuclear Information System (INIS)

    Dai, Donghua; Gu, Dongdong

    2014-01-01

    Highlights: • Thermal behavior and densification activity during SLM of composites are simulated. • Temperature distributions and melt pool dimensions during SLM are disclosed. • Motion behaviors of gaseous bubbles in laser induced melt pool are elucidated. • Simulation results show good agreement with the obtained experimental results. - Abstract: Simulation of temperature distribution and densification process of selective laser melting (SLM) WC/Cu composite powder system has been performed, using a finite volume method (FVM). The transition from powder to solid, the surface tension induced by temperature gradient, and the movement of laser beam power with a Gaussian energy distribution are taken into account in the physical model. The effect of the applied linear energy density (LED) on the temperature distribution, melt pool dimensions, behaviors of gaseous bubbles and resultant densification activity has been investigated. It shows that the temperature distribution is asymmetric with respect to the laser beam scanning area. The center of the melt pool does not locate at the center of the laser beam but slightly shifts towards the side of the decreasing X-axis. The dimensions of the melt pool are in sizes of hundreds of micrometers and increase with the applied LED. For an optimized LED of 17.5 kJ/m, an enhanced efficiency of gas removal from the melt pool is realized, and the maximum relative density of laser processed powder reaches 96%. As the applied LED surpasses 20 kJ/m, Marangoni flow tends to retain the entrapped gas bubbles. The flow pattern has a tendency to deposit the gas bubbles at the melt pool bottom or to agglomerate gas bubbles by the rotating flow in the melt pool, resulting in a higher porosity in laser processed powder. The relative density and corresponding pore size and morphology are experimentally acquired, which are in a good agreement with the results predicted by simulation

  8. Three-dimensional computed tomography angiography of coronary artery bypass graft with electron beam tomography

    Energy Technology Data Exchange (ETDEWEB)

    Hoshi, Toshiko; Yamauchi, Tatsuo; Kanauchi, Tetsu; Konno, Miyuki; Imai, Kamon; Suwa, Jiro; Onoguchi, Katsuhisa; Hashimoto, Kazuhiro; Horie, Toshinobu [Saitama Cardiovascular and Respiratory Center, Konan (Japan)

    2001-10-01

    Assessment of coronary artery bypass graft patency by three-dimensional reconstructed computed tomography angiography (3D-CTA) derived from electrocardiography-gated contrast-enhanced electron beam tomography (EBT) was evaluated. Thirty-nine patients with 99 grafts (45 arterial grafts and 54 venous grafts) underwent 3D-CTA and selective coronary angiography within a 3-week interval. 3D-CTA images of the coronary bypass grafts were compared with the coronary angiography images used as the control. 3D-CTA defined 42 of 44 arterial grafts as patent (sensitivity: 95%), all 47 venous grafts as patent (sensitivity: 100%) and all 7 venous grafts as occlusive (specificity: 100%). The overall sensitivity and specificity were 98% and 88%, respectively. 3D-CTA is an useful noninvasive technique with adequate sensitivity and specificity to assess coronary artery bypass graft patency. (author)

  9. A new approach to reducing the flammability of layered double hydroxide (LDH)-based polymer composites: preparation and characterization of dye structure-intercalated LDH and its effect on the flammability of polypropylene-grafted maleic anhydride/d-LDH composites.

    Science.gov (United States)

    Kang, Nian-Jun; Wang, De-Yi; Kutlu, Burak; Zhao, Peng-Cheng; Leuteritz, Andreas; Wagenknecht, Udo; Heinrich, Gert

    2013-09-25

    Dye structure-intercalated layered double hydroxide (d-LDH) was synthesized using a one-step method, and its intercalated behaviors have been characterized by Fourier transform infrared spectroscopy (FTIR), wide angle X-ray scattering (WAXS), scanning electron microscopy, thermogravimetric analysis (TGA), etc. As a novel functional potential fire-retarding nanofiller, it was used to prepare a polypropylene-grafted maleic anhydride (PP-g-MA)/d-LDH composite by refluxing the mixture of d-LDH and PP-g-MA in xylene, aiming to investigate its effect on the flammability of the PP-g-MA composite. The morphological properties, thermal stability, and flame retardant properties of the PP-g-MA/d-LDH composite were determined by FTIR, WAXS, transmission electron microscopy, TGA, and microscale combustion calorimetry. Compared with NO3-LDH (unmodified LDH) and LDH intercalated by sodium dodecylbenzenesulfonate (conventional organo-modified LDH), d-LDH can significantly decrease the heat release rate and the total heat release of the PP-g-MA composite, offering a new approach to imparting low flammability to LDH-based polymer composites.

  10. Patterning of gold nanoparticles on fluoropolymer films by using patterned surface grafting and layer-by-layer deposition techniques.

    Science.gov (United States)

    Jung, Chang-Hee; Hwang, In-Tae; Jung, Chan-Hee; Choi, Jae-Hak; Kwon, Oh-Sun; Shin, Kwanwoo

    2013-09-11

    The patterning of gold nanoparticles (GNPs) on the surface of a fluoropolymer substrate by using patterned surface grafting and layer-by-layer deposition techniques is described. The surface of a poly(tetrafluoroethylene-co-perfluorovinyl ether) (PFA) substrate was selectively implanted with 150 keV proton ions. Peroxide groups were successfully formed on the implanted PFA surface, and their concentration depended on the fluence. Acrylic acid was graft polymerized onto the implanted regions of the PFA substrate, resulting in well-defined patterns of poly(acrylic acid) (PAA) on the PFA substrate. The surface properties of the PAA-patterned PFA surface, such as chemical compositions, wettability, and morphology, were investigated. The surface analysis results revealed that PAA was definitely present on the implanted regions of the PFA surface, and the degree of grafting was dependent on three factors: fluence, grafting time, and monomer concentration. Furthermore, GNP patterns were generated on the prepared PAA-patterned PFA surface by layer-by-layer deposition of GNPs and poly(diallyldimethyl ammonium chloride). The multilayers of GNPs were deposited only onto the PAA-grafted regions separated by bare PFA regions, and the resulting GNP patterns exhibited good electrical conductivity.

  11. A COMPARATIVE STUDY OF TYMPANOPLASTY USING SLICED CARTILAGE GRAFT VS. TEMPORALIS FASCIA GRAFT

    Directory of Open Access Journals (Sweden)

    Rahul Ashok Telang

    2018-02-01

    Full Text Available BACKGROUND The objective of the study was to compare the hearing improvement after using sliced cartilage graft with that of temporalis fascia and to compare the graft take-up between the two graft materials. MATERIALS AND METHODS A prospective clinical study including 60 patients with chronic mucosal otitis media, who were selected randomly from the outpatient department, after obtaining their consent were divided into 2 groups of 30 each, and evaluated according the study protocol. Their pre-operative audiometry was recorded and both groups of patients underwent surgery with one of the graft materials- temporalis fascia or sliced tragal cartilage with a thickness of 0.5 mm. All patients were regularly followed up and post-operative audiometry was done at 3 months. The hearing improvement in the form of closure of air-bone-gap and graft take-up was analysed statistically. RESULTS The temporalis fascia graft group had a pre-operative ABG of 22.33 ± 6.24 dB and post-operative ABG of 12.33 ± 4.72 dB with hearing improvement of 10.00 dB. The sliced cartilage graft group had a pre-operative ABG of 20.77 ± 5.75 dB and postoperative ABG of 10.50 ± 4.46 dB with hearing improvement of 10.27 dB. In the temporalis fascia group, 28 (93.3% patients had good graft take-up and in the sliced cartilage group 29 (96.7% had good graft take-up. There was statistically significant hearing improvement in both of our study groups but there was no statistically significant difference between the two groups. There was no statistically significant difference in graft take-up also. CONCLUSION Sliced cartilage graft is a good auto-graft material in tympanoplasty, which can give good hearing improvement and has good graft take-up, which is comparable with that of temporalis fascia.

  12. Antibacterial effects of hydrogen peroxide and silver composition on selected pathogenic enterobacteriaceae

    Directory of Open Access Journals (Sweden)

    Mojtaba Davoudi

    2012-01-01

    Full Text Available Aims: Antibacterial effects of hydrogen peroxide and silver composition on selected pathogenic enterobacteriaceae was investigated in this study. Materials and Methods: The efficacy of 30 ppb silver in 0.3% hydrogen peroxide solution for inactivation of selected Enterobacteriaceae, including Escherichia coli, Proteus mirabilis, and Klebsiella pneumoniae was assessed for 72 hours in a designated nutrient broth medium and steel surface. The bactericidal growth ability was determined for each bacterium genus by the conventional colony count method and turbidimetry via an optical density (OD assay at 450 nm in a time interval of 24 hours. Results: Suspensions of K.pneumoniae, and P.mirabilis showed a significant OD reduction at three 24-hour intervals (CI = 0.95; P < 0.05, for both, along with blocked growth in a designated broth medium during 24 to 48 hours of exposure. The disinfectant was also significantly efficient for inactivating of the mentioned bacteria on steel surfaces after a 15-minute time exposure (CI = 0.95; P < 0.05. For E.coli, the OD decreased slightly during the initial exposure time, but increased after 24 hours. Viable E.coli cells were proved by colonies grown on the plate. A qualitative surface decontamination test showed that three pathogenic bacteria were inactivated significantly after disinfectant exposure (CI = 0.95, P < 0.05. Conclusions: In conclusion, a combination of hydrogen peroxide and silver ions was proposed as a strong disinfecting agent both in suspensions and on the surfaces against these three important human pathogens.

  13. Standard pentostatin dose reductions in renal insufficiency are not adequate: selected patients with steroid-refractory acute graft-versus-host disease.

    Science.gov (United States)

    Poi, Ming J; Hofmeister, Craig C; Johnston, Jeffrey S; Edwards, Ryan B; Jansak, Buffy S; Lucas, David M; Farag, Sherif S; Dalton, James T; Devine, Steven M; Grever, Michael R; Phelps, Mitch A

    2013-08-01

    Pentostatin is an irreversible inhibitor of adenosine deaminase and has been used to prevent graft-versus-host disease (GVHD) and to treat both acute and chronic GVHD. Dose reduction equations for patients with renal insufficiency are based on few patients with limited pharmacokinetic and clinical results. This phase II study (NCT00201786) was conducted to assess pentostatin efficacy and infectious complications seen from our previous phase I study in steroid-refractory acute GVHD (aGVHD). Hospitalized patients with steroid-refractory aGVHD were given pentostatin 1.5 mg/m(2)/day intravenously on days 1-3 of each 14-day cycle. Prior to each dose, dose modifications were based on Cockcroft-Gault estimated creatinine clearance (eCrCL) with 30-50 mL/min/1.73 m(2) leading to a 50 % dose reduction and eCrCL less than 30 mL/min/1.73 m(2) leading to study removal. Plasma pentostatin area under the concentration-time curve (AUC) and incidence of infectious complications were evaluated. Two of the eight patients treated demonstrated excessive pentostatin exposure as determined by measurement of AUC. One of these patients had renal impairment, whereas the other patient demonstrated borderline renal function. Despite dose reduction to 0.75 mg/m(2), AUCs were significantly increased compared to the other patients in this study. Seven of eight patients treated with pentostatin had cytomegalovirus (CMV) viremia after pentostatin treatment; however none developed proven CMV disease. A 50 % dose reduction in patients with eCrCL 30-50 mL/min/1.73 m(2) seems reasonable. However, the eCrCL should be interpreted with extreme caution in patients who are critically ill and/or with poor performance status. Renal function assessment based on the Cockcroft-Gault method could be significantly overestimated thus risking pentostatin overdosing. These results imply a need to closely monitor pentostatin exposure in patients with renal insufficiency.

  14. Outcomes of hepatitis C- and hepatitis B core antibody-positive grafts in orthotopic liver transplantation.

    Science.gov (United States)

    Saab, Sammy; Chang, Albert J; Comulada, Scott; Geevarghese, Sunil K; Anselmo, R Dean M; Durazo, Francisco; Han, Steven; Farmer, Douglas G; Yersiz, Hasan; Goldstein, Leonard I; Ghobrial, R Mark; Busuttil, Ronald W

    2003-10-01

    The use of hepatitis B core antibody (HBcAb)- and hepatitis C virus antibody (HCV+) liver grafts for transplantation in selected populations has not affected patient and graft survival. We reexamined the clinical outcomes of using these HBcAb+ and HCV+ grafts at our institution, in addition to studying recipients of combined HBcAb+/HCV+ grafts. We identified 377 patients who underwent transplantation for either hepatitis B and/or hepatitis C, or received both HBcAb+ and HCV+ grafts. Patient and graft survival at 5 years posttransplantation was 73% and 71%, respectively, in the HBcAb+ grafts compared with 81% and 75% in the HBcAb- grafts (P =.65; P =.94). For HCV+ grafts, patient and graft survival at 5 years posttransplantation was 89% and 73%, respectively, compared with 69% and 59% in the HCV- grafts; (P =.22; P =.77). The 5-year patient and graft survival rate in those who received combined HBcAb+/HCV+ grafts was 74% and 69%, respectively, and there was no statistical difference compared with the HBcAb+ and HCV+ grafts (P =.76; P =.90). The 5-year patient and graft survival rate in patients who received dual HBV prophylaxis with hepatitis B immunoglobulin (HBIg) and lamivudine was 88% and 84%, respectively, which was significantly higher than for patients who received single prophylaxis or no prophylaxis (P HBcAb+ and HCV+ grafts, and that dual prophylaxis with HBIg and lamivudine offers substantial survival benefits. Furthermore, the use of combined HBcAb+/HCV+ grafts did not impact patient or graft survival. This provides a potential new pool of donor livers that can be used for transplantation in select patients.

  15. Biodegradation Resistance and Bioactivity of Hydroxyapatite Enhanced Mg-Zn Composites via Selective Laser Melting

    Directory of Open Access Journals (Sweden)

    Cijun Shuai

    2017-03-01

    Full Text Available Mg-Zn alloys have attracted great attention as implant biomaterials due to their biodegradability and biomechanical compatibility. However, their clinical application was limited due to the too rapid degradation. In the study, hydroxyapatite (HA was incorporated into Mg-Zn alloy via selective laser melting. Results showed that the degradation rate slowed down due to the decrease of grain size and the formation of protective layer of bone-like apatite. Moreover, the grain size continually decreased with increasing HA content, which was attributed to the heterogeneous nucleation and increased number of nucleation particles in the process of solidification. At the same time, the amount of bone-like apatite increased because HA could provide favorable areas for apatite nucleation. Besides, HA also enhanced the hardness due to the fine grain strengthening and second phase strengthening. However, some pores occurred owing to the agglomerate of HA when its content was excessive, which decreased the biodegradation resistance. These results demonstrated that the Mg-Zn/HA composites were potential implant biomaterials.

  16. Biodegradation Resistance and Bioactivity of Hydroxyapatite Enhanced Mg-Zn Composites via Selective Laser Melting.

    Science.gov (United States)

    Shuai, Cijun; Zhou, Yuanzhuo; Yang, Youwen; Feng, Pei; Liu, Long; He, Chongxian; Zhao, Mingchun; Yang, Sheng; Gao, Chengde; Wu, Ping

    2017-03-17

    Mg-Zn alloys have attracted great attention as implant biomaterials due to their biodegradability and biomechanical compatibility. However, their clinical application was limited due to the too rapid degradation. In the study, hydroxyapatite (HA) was incorporated into Mg-Zn alloy via selective laser melting. Results showed that the degradation rate slowed down due to the decrease of grain size and the formation of protective layer of bone-like apatite. Moreover, the grain size continually decreased with increasing HA content, which was attributed to the heterogeneous nucleation and increased number of nucleation particles in the process of solidification. At the same time, the amount of bone-like apatite increased because HA could provide favorable areas for apatite nucleation. Besides, HA also enhanced the hardness due to the fine grain strengthening and second phase strengthening. However, some pores occurred owing to the agglomerate of HA when its content was excessive, which decreased the biodegradation resistance. These results demonstrated that the Mg-Zn/HA composites were potential implant biomaterials.

  17. Analytical phenolic composition and sensory assessment of selected rare Greek cultivars after extended bottle ageing.

    Science.gov (United States)

    Stamatina, Kallithraka; Yorgos, Kotseridis; Maria, Kyraleou; Niki, Proxenia; Argirios, Tsakiris; Garifalia, Karapetrou

    2015-06-01

    The Hellenic vineyard embraces a large number of native cultivars, which are mostly unexploited for their ageing potential. Therefore, it was thought that analyzing some quality parameters of 14 red wines produced by rare native varieties would be of great importance in obtaining a general picture of their potential for commercial use. Various analytical methods were applied to the selected wines, at bottling and after 8 years of ageing, in an attempt to provide reliable answers to this issue. In addition, it was of interest to investigate the alteration of the phenolic content and color parameters of the wines after extended bottle storage and to evaluate the overall changes with respect to their sensory properties. Most of the oligomeric phenolic compounds identified in the wines studied diminished after 8 years of bottle storage, while significant correlations were obtained between wine chemical composition and sensory data. After 8 years of bottle storage some of the unexploited varieties (Vitis vinifera) were found to be worthy of further study and use for the production of quality wines. Wines with the best sensory characteristics were those made by Limniona, Mavrotragano, Bakouri, Thrapsa and Mavrothiriko, in accordance (more or less) with the results of chemical analyses. © 2014 Society of Chemical Industry.

  18. Bone Graft Alternatives

    Science.gov (United States)

    ... spinal deformity, or who have some types of disc herniations. In certain types of spinal fusion, bone grafts ... Specialist SEARCH Download Brochure ENGLISH Related Treatments Cervical Disc Herniation Fusion Lumbar Disc Herniation {1} ##LOC[OK]## {1} ## ...

  19. Melting graft wound syndrome

    Directory of Open Access Journals (Sweden)

    Shiou-Mei Chen

    2017-09-01

    Full Text Available Melting graft wound syndrome is characterized by progressive epidermal loss from a previously well-taken skin graft, healed burn, or donor site. It may result in considerable morbidity and require prolonged treatment. We report a 23-year-old flame-burned patient with second- to third-degree burns involving more than 70% of the total body surface area, whose condition was complicated with septic shock. The patient presented with erosions and ulcers occurring on previously well-taken skin graft recipient sites over both legs and progressive epidermal loss on donor sites over the back. The patient's presentation was compatible with the diagnosis of melting graft wound syndrome, and we successfully treated the patient with debridement and supportive treatment.

  20. Radiographic analysis of pasteurized autologous bone graft

    International Nuclear Information System (INIS)

    Ahmed, Adel Refaat; Manabe, Jun; Kawaguchi, Noriyoshi; Matsumoto, Seiichi; Matsushita, Yasushi

    2003-01-01

    Local malignant bone tumor excision followed by pasteurization and subsequent reimplantation is a unique technique for reconstruction after resection of primary bone sarcomas. The purpose of this investigation was to assess the normal and abnormal long-term radiographic findings of intercalary and osteo-chondral pasteurized bone graft/implant composite. The long-term radiographic findings of pasteurized bone grafts used in reconstruction after resection of bone and soft tissue sarcomas in relation to patients' clinical data were reviewed retrospectively. Thirty-one patients (18 females, 13 males; age range 7-77 years, mean 30 years) who underwent surgery between April 1990 and January 1997 at the authors' institute constituted the material of this study. They were followed up for at least 3 years or until the patient's death (mean 69 months). The International Society of Limb Salvage graft evaluation method that assesses the fusion, resorption, fracture, graft shortening, fixation, subluxation, joint narrowing and subchondral bone was used for evaluation of the radiographs. Twenty-one patients (68%) showed complete incorporation of graft and eight patients (26%) had partial incorporation. The overall radiographic evaluation rate was 81%. Fracture (10%) and infection (16%) were the main complications. No local recurrence was detected. These results indicate that pasteurization of bone is a useful option for reconstruction after resection of malignant bone tumors. (orig.)

  1. Radiographic analysis of pasteurized autologous bone graft.

    Science.gov (United States)

    Ahmed, Adel Refaat; Manabe, Jun; Kawaguchi, Noriyoshi; Matsumoto, Seiichi; Matsushita, Yasushi

    2003-08-01

    Local malignant bone tumor excision followed by pasteurization and subsequent reimplantation is a unique technique for reconstruction after resection of primary bone sarcomas. The purpose of this investigation was to assess the normal and abnormal long-term radiographic findings of intercalary and osteo-chondral pasteurized bone graft/implant composite. The long-term radiographic findings of pasteurized bone grafts used in reconstruction after resection of bone and soft tissue sarcomas in relation to patients' clinical data were reviewed retrospectively. Thirty-one patients (18 females, 13 males; age range 7-77 years, mean 30 years) who underwent surgery between April 1990 and January 1997 at the authors' institute constituted the material of this study. They were followed up for at least 3 years or until the patient's death (mean 69 months). The International Society of Limb Salvage graft evaluation method that assesses the fusion, resorption, fracture, graft shortening, fixation, subluxation, joint narrowing and subchondral bone was used for evaluation of the radiographs. Twenty-one patients (68%) showed complete incorporation of graft and eight patients (26%) had partial incorporation. The overall radiographic evaluation rate was 81%. Fracture (10%) and infection (16%) were the main complications. No local recurrence was detected. These results indicate that pasteurization of bone is a useful option for reconstruction after resection of malignant bone tumors.

  2. Radiographic analysis of pasteurized autologous bone graft

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Adel Refaat [Department of Orthopedic Surgery, Cancer Institute Hospital, Japanese Foundation for Cancer Research, Kamiikebukuro 1-37-1, Toshima-ku, 170-0012, Tokyo (Japan); Department of Orthopedic Surgery, Alexandria University, Alexandria (Egypt); Manabe, Jun; Kawaguchi, Noriyoshi; Matsumoto, Seiichi; Matsushita, Yasushi [Department of Orthopedic Surgery, Cancer Institute Hospital, Japanese Foundation for Cancer Research, Kamiikebukuro 1-37-1, Toshima-ku, 170-0012, Tokyo (Japan)

    2003-08-01

    Local malignant bone tumor excision followed by pasteurization and subsequent reimplantation is a unique technique for reconstruction after resection of primary bone sarcomas. The purpose of this investigation was to assess the normal and abnormal long-term radiographic findings of intercalary and osteo-chondral pasteurized bone graft/implant composite. The long-term radiographic findings of pasteurized bone grafts used in reconstruction after resection of bone and soft tissue sarcomas in relation to patients' clinical data were reviewed retrospectively. Thirty-one patients (18 females, 13 males; age range 7-77 years, mean 30 years) who underwent surgery between April 1990 and January 1997 at the authors' institute constituted the material of this study. They were followed up for at least 3 years or until the patient's death (mean 69 months). The International Society of Limb Salvage graft evaluation method that assesses the fusion, resorption, fracture, graft shortening, fixation, subluxation, joint narrowing and subchondral bone was used for evaluation of the radiographs. Twenty-one patients (68%) showed complete incorporation of graft and eight patients (26%) had partial incorporation. The overall radiographic evaluation rate was 81%. Fracture (10%) and infection (16%) were the main complications. No local recurrence was detected. These results indicate that pasteurization of bone is a useful option for reconstruction after resection of malignant bone tumors. (orig.)

  3. Composites

    OpenAIRE

    Zhao, Hanqing; Guo, Yuanzheng

    2014-01-01

    This thesis was a literature study concerning composites. With composites becoming increasingly popular in various areas such as aerospace industry and construction, the research about composites has a significant meaning accordingly. This thesis was aim at introducing some basic information of polymer matrix composites including raw mate-rial, processing, testing, applications and recycling to make a rough understanding of this kind of material for readers. Polymeric matrices, fillers,...

  4. Sensitivity of selected landscape pattern metrics to land-cover misclassification and differences in land-cover composition

    Science.gov (United States)

    James D. Wickham; Robert V. O' Neill; Kurt H. Riitters; Timothy G. Wade; K. Bruce Jones

    1997-01-01

    Calculation of landscape metrics from land-cover data is becoming increasingly common. Some studies have shown that these measurements are sensitive to differences in land-cover composition, but none are known to have tested also their a sensitivity to land-cover misclassification. An error simulation model was written to test the sensitivity of selected land-scape...

  5. Ion-Selective Ionic Polymer Metal Composite (IPMC) Actuator Based on Crown Ether Containing Sulfonated Poly(Arylene Ether Ketone)

    NARCIS (Netherlands)

    Tas, Sinem; Zoetebier, Bram; Sardan Sukas, Ö.; Bayraktar, Muharrem; Hempenius, Mark A.; Vancso, Gyula J.; Nijmeijer, Dorothea C.

    This study introduces the concept of ion selective actuation in polymer metal composite actuators, employing crown ether bearing aromatic polyether materials. For this purpose, sulfonated poly(arylene ether ketone) (SPAEK) and crown ether containing SPAEK with molar masses suitable for membrane

  6. Composition

    DEFF Research Database (Denmark)

    Bergstrøm-Nielsen, Carl

    2011-01-01

    Strategies are open compositions to be realised by improvising musicians. See more about my composition practise in the entry "Composition - General Introduction". Caution: streaming the sound files will in some cases only provide a few minutes' sample. Please DOWNLOAD them to hear them in full...

  7. Composition

    DEFF Research Database (Denmark)

    2014-01-01

    Memory Pieces are open compositions to be realised solo by an improvising musicians. See more about my composition practise in the entry "Composition - General Introduction". Caution: streaming the sound files will in some cases only provide a few minutes' sample. Please DOWNLOAD them to hear them...

  8. Composition

    DEFF Research Database (Denmark)

    Bergstrøm-Nielsen, Carl

    2010-01-01

    New Year is an open composition to be realised by improvising musicians. It is included in "From the Danish Seasons" (see under this title). See more about my composition practise in the entry "Composition - General Introduction". This work is licensed under a Creative Commons "by-nc" License. You...

  9. 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

  10. Use and preservation methods of bone grafts in small animals

    Directory of Open Access Journals (Sweden)

    Rafael Garabet Agopian

    2016-09-01

    Full Text Available The present review describes the main characteristics of bone grafts used in small animals. Bone grafts are tissues without vasculature, which facilitate the production of new bone cells with osteogenic and osteoinductive factors that lead to the differentiation of cells and structural support for bone marrow. The transplant of a graft is followed by three stages: osteogenesis, or the formation of new bone; osteoinduction, which is the differentiation of cells; and osteoconduction, the process of growth of mesenchymal cells and capillaries that results in new bone formation. The composition of bone grafts may include spongy bone, cortical bone, cortical-spongy bone, cartilage or bone marrow. Grafts can also be classified according to their origin, being autogenous tissue when they are transplanted from the same individual, allogenous (homologous when originating from another individual of the same species, and xenogenous when obtained from a different species.

  11. Effect of domain size and interface characteristics on the impact resistance of selected polymer composites

    Science.gov (United States)

    Viratyaporn, Wantinee

    Nanocomposite technology has advanced considerably in recent years and excellent engineering properties have been achieved in numerous systems. In multiphase materials the enhancement of properties relies heavily on the nature at the interphase region between polymer domains and nanoparticle reinforcements. Strong adhesion between the phases provides excellent load-transfer and good mechanical elastic modulus and strength, whereas weak interaction contributes to crack deflection mechanisms and toughness. Polymer molecules are large and the presence of comparably sized filler particles affects chain gyration, which in turn influences the conformation of the polymer and the properties of the composite. Nanoparticles were incorporated into a poly(methyl methacrylate) matrix by means of in situ free radical (bulk) polymerization. Aluminum oxide and zinc oxide nanoparticles were added to study the effects of particle chemistry and shape on selected mechanical properties such as impact resistance, which showed significant improvement at a certain loading of zinc oxide. The elongated shape of zinc oxide particles appears to promote crack deflection processes and to introduce a pull-out mechanism similar to that observed in fiber composite systems. Moreover, the thermal stability of PMMA was improved with the addition of nanoparticles, apparently by steric hindrance of polymer chain motion and a second mechanism related to the dipole inducing effect of the oxide particles. The sensitivity of infrared spectroscopy to changes in molecular dipoles was used to study the nature of the polymer/particle interface. The results revealed some interesting aspects of the secondary bonds between polymers and oxides. Raman spectroscopy was used to investigate the extent of polymerization and changes in polymer conformation. A degree of polymerization of 93% was achieved in neat PMMA, and even when 5.0 v/o of PGMEA was introduced into the system no monomer was detected. However, when

  12. Impact of Selection for Digestive Efficiency on Microbiota Composition in the Chicken.

    Science.gov (United States)

    Mignon-Grasteau, Sandrine; Narcy, Agnès; Rideau, Nicole; Chantry-Darmon, Céline; Boscher, Marie-Yvonne; Sellier, Nadine; Chabault, Marie; Konsak-Ilievski, Barbara; Le Bihan-Duval, Elisabeth; Gabriel, Irène

    2015-01-01

    Feed efficiency and its digestive component, digestive efficiency, are key factors in the environmental impact and economic output of poultry production. The interaction between the host and intestinal microbiota has a crucial role in the determination of the ability of the bird to digest its food and to the birds' feed efficiency. We therefore investigated the phenotypic and genetic relationships between birds' efficiency and the composition of the cecal microbiota in a F2 cross between broiler lines divergently selected for their high or low digestive efficiency. Analyses were performed on 144 birds with extreme feed efficiency values at 3 weeks, with feed conversion values of 1.41±0.05 and 2.02±0.04 in the efficient and non-efficient groups, respectively. The total numbers of Lactobacillus, L. salivarius, L. crispatus, C. coccoides, C. leptum and E. coli per gram of cecal content were measured. The two groups mainly differed in larger counts of Lactobacillus, L. salivarius and E. coli in less efficient birds. The equilibrium between bacterial groups was also affected, efficient birds showing higher C. leptum, C. coccoides and L. salivarius to E. coli ratios. The heritability of the composition of microbiota was also estimated and L. crispatus, C. leptum, and C. coccoides to E. coli ratios were moderately but significantly heritable (0.16 to 0.24). The coefficient of fecal digestive use of dry matter was genetically and positively correlated with L. crispatus, C. leptum, C. coccoides (0.50 to 0.76) and negatively with E. coli (-0.66). Lipid digestibility was negatively correlated with E. coli (-0.64), and AMEn positively correlated with C. coccoides and with the C. coccoides to Lactobacillus ratio (0.48 to 0.64). We also detected 14 Quantitative Trait Loci (QTL) for microbiota on the host genome, mostly on C. leptum and Lactobacillus. The QTL for C. leptum on GGA6 was close to genome-wide significance. This region mainly includes genes involved in anti

  13. Boron contents and isotopic compositions of hog manure, selected fertilizers, and water in Minnesota

    Science.gov (United States)

    Komor, S.C.

    1997-01-01

    Boron-isotope (δ11B) values may be useful as surrogate tracers of contaminants and indicators of water mixing in agricultural settings. This paper characterizes the B contents and isotopic compositions of hog manure and selected fertilizers, and presents δ11B data for ground and surface water from two agricultural areas. Boron concentrations in dry hog manure averaged 61 mg/kg and in commercial fertilizers ranged from below detection limits in some brands of ammonium nitrate and urea to 382 mg/kg in magnesium sulfate. Values of δ11B of untreated hog manure ranged from 7.2 to 11.2o/oo and of N fertilizers were −2.0 to 0.7o/oo. In 22 groundwater samples from a sand-plain aquifer in east-central Minnesota, B concentrations averaged 0.04 mg/L and δ11B values ranged from 2.3 to 41.5o/oo. Groundwater beneath a hog feedlot and a cultivated field where hog manure was applied had B-isotope compositions consistent with the water containing hog-manure leachate. In a 775-km2 watershed with silty-loam soils in southcentral Minnesota: 18 samples of subsurface drainage from corn (Zea mays L.) and soybean (Glycine max L. Merr.) fields had average B concentrations of 0.06 mg/L and δ11B values of 5.3 to 15.1o/oo; 27 stream samples had average B concentrations of 0.05 mg/L and δ11B values of 1.0 to 19.0o/oo; and eight groundwater samples had average B concentrations of 0.09 mg/L and δ11B values of −0.3 to 23.0o/oo. Values of δ11B and B concentrations, when plotted against one another, define a curved mixing trend that suggests subsurface drainage and stream water contain mixtures of B from shallow and deep groundwater.

  14. Composition and distribution of selected munnopsid genera (Crustacea, Isopoda, Asellota) in Icelandic waters

    Science.gov (United States)

    Schnurr, Sarah; Brandt, Angelika; Brix, Saskia; Fiorentino, Dario; Malyutina, Marina; Svavarsson, Jörundur

    2014-02-01

    The Greenland-Scotland Ridge (GSR) is a major topographic feature, extending from Greenland to Scotland. It constrains the water exchange between the northernmost North Atlantic Ocean and the Greenland, Iceland and Norwegian Seas (GIN Seas) and thus forms a potential barrier for faunal exchange from the Arctic to the North Atlantic (and vice versa). Recently an increase in Atlantic water inflow has been observed, leading to changes in physical parameters (i.e. temperature and salinity), which may have an impact on the resident fauna. In this study, we analyzed the composition and distribution of six selected genera of the isopod family Munnopsidae (Crustacea) occurring north and south of the GSR. We examined 82 epibenthic sledge samples and 26 additional sub-samples taken in the course of the Benthic Invertebrates of Icelandic Waters (BIOICE) and Icelandic Marine Animals: Genetics and Ecology (IceAGE) projects, respectively, covering a total depth range from 103 to 2752 m depth. Overall, 58 of the evaluated stations originated in the area north of the GSR, while the remaining 50 samples were collected south of the ridge. In total, 10517 individuals could be assigned to 15 species, most belonging to the genus EurycopeSars, 1864. Due to the presence of the GSR as well as differences in the environment, we expected significant dissimilarities in faunal composition between the two study areas. However, most species (8) occurred on both sides of the ridge, while four species were restricted to the region north of Iceland, and three to the region south of the ridge. Depth (or factors related to depth) appeared to be the most important factor in driving distributional patterns of the studied species. Temperature was also an important driver, but not to the same extent as depth. On the contrary, salinity and sediment type did not have much influence on munnopsid distribution patterns. Hence, the presence of the ridge does not restrict faunal exchange between the northern

  15. Corrosive effect of environmental change on selected properties of polymer composites

    Science.gov (United States)

    Markovičová, L.; Zatkalíková, V.

    2017-11-01

    The development of composite materials and the related design and manufacturing technologies is one of the most important advances in the history of materials. Composites are multifunctional materials having unprecedented mechanical and physical properties that can be tailored to meet the requirements of a particular application. Ageing is also important and it is defined as the process of deterioration of engineering materials resulting from the combined effects of atmospheric radiation, heat, oxygen, water, micro-organisms and other atmospheric factors. The present article deals with monitoring the changes in the mechanical properties of composites with polymer matrix. The composite was formed from the PA matrix and glass fibers (GF). The composite contains 10, 20 and 30 % of glass fibers. The mechanical properties were evaluated on samples of the composite before and after UV radiation on the sample. Light microscopy was evaluated distribution of glass fibers in the polymer matrix and the presence of cracks caused by UV radiation.

  16. Influence of Pectolytic Enzymes and Selected Yeast Strains on the Chemical Composition of Blackberry Wines

    Directory of Open Access Journals (Sweden)

    Tomić Antonija

    2018-09-01

    Full Text Available The aim of this study was to determine concentrations of individual o rganic acids, polyphenolic and aromatic compounds in blackberry wine, and to define the influence of different yeast strains (Uvaferm BDX and Lalvin 71B and pectolytic enzymes (L allzyme OE and Lallzyme EX-V on the chemical composition and quality of the wine. Blackberry wines were produced in five variants, depending on yeasts and enzymes used: BDX OE, BDX EX-V, 71B OE, 71B EX-V, and Control without the addition of selected yeasts and enzymes. All blackberry wine variants were defined by a relatively high sum of organic acids. The citric acid was the predominant one, which concentrations ranged from 5.42 to 7.31 g/L. The concentration of gallic acid ranged from 19 to 37 mg/L and was in dependence of the yeast strain used. The concentration of procyanidin B2 which was the predominant flavan-3-ol compound, ranged from 103 to 117 mg/L, and there were no significant differences between individual wine variants in the experiment. Rutin is the predominant compound in the flavonol group, followed by quercetin-3-O-glucoside. The predominant one among the anthocyanins was cyanidin-3-O-glucoside whose concentrations ranged from 134 to 229 mg/L. According to the obtained results, the yeast strain and pectolytic enzymes had a significant impact on the concentration of individual anthocyanins in the analyzed wines. The predominant group of aromatic compounds was monoterpenes, among which linalool was the most prominent in all of blackberry wine variants, except in Control.

  17. Yolk-shell structured composite for fast and selective lithium ion sieving.

    Science.gov (United States)

    Li, Na; Lu, Deli; Zhang, Jinlong; Wang, Lingzhi

    2018-06-15

    Yolk-shell structured C@Li 4 Ti 5 O 12 microspheres composed of carbon core (ca. 500 nm) and sea urchin-like Li 4 Ti 5 O 12 shell (ca. 400-500 nm) are formed by hydrothermally treating the core-shell structured C@TiO 2 in the EtOH/H 2 O solution of LiOH and calcining it in N 2 atmosphere. Yolk-shell structured TiO 2 -type lithium ion sieve is further transformed from C@Li 4 Ti 5 O 12 through the acid treatment, which have a high specific surface area of 201.74 m 2 /g. The composite shows adsorption capacity towards Li + proportional to the pH value in the range of 7-13. The adsorption reaches equilibrium within 2 h with a high equilibrium adsorption capacity of 28.46 mg/g under alkaline conditions, which is ca. 8 times the value of ordinary TiO 2 lithium ion sieve with comparable size and surface area, demonstrating the enhanced adsorption is attributed to the generation of more accessible surficial voids by replacing internal part with light carbon core. The adsorption follows Freundlich and pseudo-second-order kinetic models with a high rate constant of 0.015 g/(mg·min). The selective adsorption to Li + is verified in the presence of K + , Na + , Ca 2+ and Mg 2+ . Copyright © 2018 Elsevier Inc. All rights reserved.

  18. Controlling the size and morphology of precipitated calcite particles by the selection of solvent composition

    Science.gov (United States)

    Konopacka-Łyskawa, Donata; Kościelska, Barbara; Karczewski, Jakub

    2017-11-01

    Precipitated calcium carbonate is used as an additive in the manufacture of many products. Particles with specific characteristics can be obtained by the selection of precipitation conditions, including temperature and the composition of solvent. In this work, calcium carbonate particles were obtained in the reaction of calcium hydroxide with carbon dioxide at 65 °C. Initial Ca(OH)2 suspensions were prepared in pure water and aqueous solutions of ethylene glycol or glycerol of the concentration range up to 20% (vol.). The course of reaction was monitored by conductivity measurements. Precipitated solids were analyzed by FTIR, XRD, SEM and the particles size distribution was determined by a laser diffraction method. The adsorption of ethylene glycol or glycerol on the surface of scalenohedral and rhombohedral calcite was testes by a normal-phase high-performance liquid chromatography. The addition of organic solvents changed the viscosity of reaction mixtures, the rate of carbon dioxide absorption and the solubility of inorganic components and therefore influence calcium carbonate precipitation conditions. All synthesized calcium carbonate products were in a calcite form. Scalenohedral calcite crystals were produced when water was a liquid phase, whereas addition of organic solvents resulted in the formation of rhombo-scalenohedral particles. The increase in organic compounds concentration resulted in the decrease of mean particles size from 2.4 μm to 1.7 μm in ethylene glycol solutions and to 1.4 μm in glycerol solutions. On the basis of adsorption tests, it was confirm that calcite surface interact stronger with glycerol than ethylene glycol. The interaction between scalenohedral calcite and used organic additives was higher in comparison to the pure rhombohedral form applied as a stationary phase.

  19. Synthesis and characterization of acrylamide-N-isopropyl acrylamide copolymer grafts on silicone rubber substrates

    Science.gov (United States)

    Uenoyama, Satoshi; Hoffman, Allan S.

    Radiation grafting has been used to modify the surface composition of a polymeric biomaterial without changing its mechanical properties. The graft copolymer surface modifications may result in significant changes in protein and cell adhesion to the surface, and thus in the overall biological response to the foreign material. In this paper we present a study of the radiation grafting of an unusual monomer, N-isopropyl acrylamide, and its copolymers with acrylamide, onto silicone rubber. This graft system may be able to influence protein adsorption and cell interactions in a unique fashion due to the special hydrophilic/hydrophobic balance and the unusual hydration character of the grafted copolymer.

  20. Caraterização composicional do AES - um copolímero de enxertia de poli(estireno-co-acrilonitrila em poli(etileno-co-propileno-co-dieno Compositional characterization of AES a graft copolymer based on poly(styrene-co-acrylonitrile and poly(etyhlene-co-propylene-co-diene

    Directory of Open Access Journals (Sweden)

    Renato Turchet

    2006-06-01

    Full Text Available O objetivo deste trabalho é a caracterização do AES, um copolímero de enxertia de poli(estireno-co-acrilonitrila, SAN, em poli(etileno-co-propileno-co-dieno, EPDM. Para tanto, o AES foi submetido à extração seletiva de seus componentes: o SAN livre, o EDPM livre, e o copolímero de enxertia EPDM-g-SAN. O AES e suas frações foram caracterizados por espectroscopia de infravermelho, análise elementar, calorimetria diferencial de varredura e ressonância magnética nuclear, RMN¹H e RMN13C. O AES analisado apresenta a seguinte composição em massa: 65% de EPDM-g-SAN, 13% de EPDM livre e 22% de SAN livre. O EPDM apresenta 69,8% em massa de etileno, 26,5% em massa de propileno e 4,6% em massa do dieno, 2-etilideno-5-norboneno, ENB. O SAN apresenta razão em massa acrilonitrila/estireno de 28/72 e distribuição randômica de comonômeros de estireno e acrilonitrila. Estes resultados são concordantes com a composição do AES fornecida pelo fabricante, indicando que a metodologia proposta é adequada.This work aims the characterization of AES, a graft copolymer based on poly(styrene-co-acrylonitrile, SAN, and poly(etyhlene-co-propylene-co-diene, EPDM. AES was submitted to selective extraction of its components: free SAN, EPDM chains and the graft copolymer EPDM-g-SAN. AES and its fractions were characterized by infrared spectroscopy, elemental analysis, differential scanning calorimetry, 13C and ¹H nuclear magnetic resonance. The AES has 65 wt % of EPDM-g-SAN, 13 wt % of free EPDM and 22 wt % of free SAN. EPDM has 69.8 wt % of ethylene, 26.5 wt % of propylene and 4.6 wt % of diene, 2-ethylidene-5-norbonene ENB. SAN presents acrylonitrile/styrene mass ratio of 28/72 and a random distribution of acrylonitrile and styrene comonomers. These results are in agreement with the composition reported by the AES supplier, indicating that the proposed methodology is adequate.

  1. Methodology of research for qualitative composition of municipal solid waste to select an optimal method of recycling

    Science.gov (United States)

    Kravtsova, M. V.; Volkov, D. A.

    2015-09-01

    The article offers research methodology for qualitative composition of municipal solid waste to select an optimal method of recycling. The resource potential of waste directly depends on its composition and determines effectiveness of using various techniques, including separation and separate collection of refuge. The decision on re-equipment of waste-separating enterprise, which decreases the supply of waste to the burial site and provides economy of nonrenewable energy sources, is well-grounded, because it allows to diminish an anthropogenic load on environment.

  2. Axillobifemoral bypass grafting

    Directory of Open Access Journals (Sweden)

    Davidović Lazar B.

    2004-01-01

    Full Text Available INTRODUCTION Axillo-femoral bypass (AxF means connecting the axillar and femoral artery with the graft that is placed subcutaneously [1]. Usually, this graft is connected with contralateral femoral artery via one accessory subcutaneous graft, and this connection is known as axillobifemoral bypass (AxFF. This extra-anatomic procedure is an alternative method to the standard reconstruction of aortoiliac region when there are contraindications for general or local reasons. OBJECTIVE The objective of this paper is to show early and late results of AxFF bypass grafting as well as to show the indications for AxFF bypass. METHODS The sample consisted of 37 patients. The procedure was performed in 28 patients who suffered from aortoiliac occlusive disease and who were at high risk due to the comorbidity- in one patient with the rupture of juxtarenal aneurysm of abdominal aorta; in five patients with aortoenteric fistula, in two patients with iatrogenic lesion of abdominal aorta and in one female patient with anus preternaturalis definitivus who was treated for rectovaginal fistula. Donor's right axillary artery was used in 26 cases (70.3%, and donor's left axillary artery was used in 9 cases (29.7%. Dacron graft was used in 34 patients and Polytetrafluo-roethlylene graft was used in three patients. Simultaneously, profundo-plastic was done in four patients and femoro-popliteal bypass was performed in three patients. In five patients who suffered from aortoenteric fistula, simultaneous intervention of gastrointerstinal system has been done, x2 test was used for statistical evaluation and life table method was used for verification of late graft patency. RESULTS The rate of early postoperative mortality was 13.5%. The causes of death were: sepsis -1, MOFS - 3, and infarct myocardium -1. The mean follow up period was 40.1 months, ranging from six months to 17 years. During the follow up period, an early graft thrombosis was identified in two and late graft

  3. Dextran grafting on PTFE surface for cardiovascular applications

    Science.gov (United States)

    Michel, Eléonore C; Montaño-Machado, Vanessa; Chevallier, Pascale; Labbé-Barrère, Amélie; Letourneur, Didier; Mantovani, Diego

    2014-01-01

    The modification of biomaterial surfaces with biomolecules influences the biological response. In this work, caboxymethyldextrans (CMD) with different degrees of substitution have been grafted to surfaces by introduction of amino moieties directly onto the substrate surface. Polytetrafluoroethylene was selected as a model substrate for biomaterial as it is already largely used for cardiovascular clinical applications. Firstly, CMD polymers were characterized by FTIR, 1H-NMR, and conductimetric titration. Then, the coatings have been analyzed by XPS to confirm the grafting and determine the composition. Once characterized, biological performances of CMD coatings were investigated. The hemocompatibility was ascertained using the free hemoglobin method. The effects on endothelial and smooth muscle cell adhesion were also studied. Results indicated that CMD at a 0.2 substitution degree, significantly influenced the biological property of PTFE by exhibiting non-thrombogenic properties as well as enhancing endothelial cell adhesion along with limiting smooth muscle cell adhesion. This work suggested the creation of versatile pro-active biomaterials suitable for different biomedical applications. PMID:25482414

  4. Musical Preferences for Compositions by Selected Students Aged 9-15 Years.

    Science.gov (United States)

    Carlin, Joi

    1997-01-01

    Explores the factors that may influence the decisions made by students aged 9-15 years old as they chose musical sounds and constructed compositions. Indicates that age, formal music training, and aesthetic response to musical sounds are the primary factors affecting specific choices made in the compositional process. (CMK)

  5. Thermosensitive membranes by radiation-induced graft polymerization of N-isopropyl acrylamide/acrylic acid on polypropylene nonwoven fabric

    International Nuclear Information System (INIS)

    Ikram, Saiqa; Kumari, Mamta; Gupta, Bhuvanesh

    2011-01-01

    Radiation-induced graft copolymerization of N-isopropylacrylamide (NIPAAm) and acrylic acid (AA) mixture was investigated on polypropylene nonwoven fabric to develop a thermosensitive material. The grafting was carried out using methanol, acetone and butanone as homopolymerization inhibitor in the reaction medium. Butanone was observed to give the maximum grafting. It was observed that the grafting is significantly influenced by the reaction conditions, such as radiation dose, monomer concentration, monomer ratio, solvent composition and reaction temperature. The degree of grafting increased as the AA and NIPAAm concentration in the reaction medium increased. The degree of grafting increased as the AA fraction in the NIPAAm/AA mixture increased. The temperature dependence of the grafting process is very much governed by the thermosensitive nature of the grafted chains right from the stage when initial grafting has taken place.

  6. Thermosensitive membranes by radiation-induced graft polymerization of N-isopropyl acrylamide/acrylic acid on polypropylene nonwoven fabric

    Energy Technology Data Exchange (ETDEWEB)

    Ikram, Saiqa; Kumari, Mamta [Department of Chemistry, Jamia Millia Islamia (Central University), New Delhi-110025 (India); Gupta, Bhuvanesh, E-mail: bgupta@textile.iitd.ernet.i [Department of Textile Technology, Indian Institute of Technology, New Delhi-110016 (India)

    2011-01-15

    Radiation-induced graft copolymerization of N-isopropylacrylamide (NIPAAm) and acrylic acid (AA) mixture was investigated on polypropylene nonwoven fabric to develop a thermosensitive material. The grafting was carried out using methanol, acetone and butanone as homopolymerization inhibitor in the reaction medium. Butanone was observed to give the maximum grafting. It was observed that the grafting is significantly influenced by the reaction conditions, such as radiation dose, monomer concentration, monomer ratio, solvent composition and reaction temperature. The degree of grafting increased as the AA and NIPAAm concentration in the reaction medium increased. The degree of grafting increased as the AA fraction in the NIPAAm/AA mixture increased. The temperature dependence of the grafting process is very much governed by the thermosensitive nature of the grafted chains right from the stage when initial grafting has taken place.

  7. Characterisation of PDO olive oil Chianti Classico by non-selective (UV-visible, NIR and MIR spectroscopy) and selective (fatty acid composition) analytical techniques.

    Science.gov (United States)

    Casale, M; Oliveri, P; Casolino, C; Sinelli, N; Zunin, P; Armanino, C; Forina, M; Lanteri, S

    2012-01-27

    An authentication study of the Italian PDO (protected designation of origin) extra virgin olive oil Chianti Classico was performed; UV-visible (UV-vis), Near-Infrared (NIR) and Mid-Infrared (MIR) spectroscopies were applied to a set of samples representative of the whole Chianti Classico production area. The non-selective signals (fingerprints) provided by the three spectroscopic techniques were utilised both individually and jointly, after fusion of the respective profile vectors, in order to build a model for the Chianti Classico PDO olive oil. Moreover, these results were compared with those obtained by the gas chromatographic determination of the fatty acids composition. In order to characterise the olive oils produced in the Chianti Classico PDO area, UNEQ (unequal class models) and SIMCA (soft independent modelling of class analogy) were employed both on the MIR, NIR and UV-vis spectra, individually and jointly, and on the fatty acid composition. Finally, PLS (partial least square) regression was applied on the UV-vis, NIR and MIR spectra, in order to predict the content of oleic and linoleic acids in the extra virgin olive oils. UNEQ, SIMCA and PLS were performed after selection of the relevant predictors, in order to increase the efficiency of both classification and regression models. The non-selective information obtained from UV-vis, NIR and MIR spectroscopy allowed to build reliable models for checking the authenticity of the Italian PDO extra virgin olive oil Chianti Classico. Copyright © 2011 Elsevier B.V. All rights reserved.

  8. Microstructure and property evolutions of titanium/nano-hydroxyapatite composites in-situ prepared by selective laser melting.

    Science.gov (United States)

    Han, Changjun; Wang, Qian; Song, Bo; Li, Wei; Wei, Qingsong; Wen, Shifeng; Liu, Jie; Shi, Yusheng

    2017-07-01

    Titanium (Ti)-hydroxyapatite (HA) composites have the potential for orthopedic applications due to their favorable mechanical properties, excellent biocompatibility and bioactivity. In this work, the pure Ti and nano-scale HA (Ti-nHA) composites were in-situ prepared by selective laser melting (SLM) for the first time. The phase, microstructure, surface characteristic and mechanical properties of the SLM-processed Ti-nHA composites were studied by X-ray diffraction, transmission electron microscope, atomic force microscope and tensile tests, respectively. Results show that SLM is a suitable method for fabricating the Ti-nHA composites with refined microstructure, low modulus and high strength. A novel microstructure evolution can be illustrated as: Relatively long lath-shaped grains of pure Ti evolved into short acicular-shaped and quasi-continuous circle-shaped grains with the varying contents of nHA. The elastic modulus of the Ti-nHA composites is 3.7% higher than that of pure Ti due to the effect of grain refinement. With the addition of 2% nHA, the ultimate tensile strength significantly reduces to 289MPa but still meets the application requirement of bone implants. The Ti-nHA composites exhibit a remarkable improvement of microhardness from 336.2 to 600.8 HV and nanohardness from 5.6 to 8.3GPa, compared to those of pure Ti. Moreover, the microstructure and property evolution mechanisms of the composites with the addition of HA were discussed and analyzed. It provides some new knowledge to the design and fabrication of biomedical material composites for bone implant applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Grafts for Ridge Preservation

    Science.gov (United States)

    Jamjoom, Amal; Cohen, Robert E.

    2015-01-01

    Alveolar ridge bone resorption is a biologic phenomenon that occurs following tooth extraction and cannot be prevented. This paper reviews the vertical and horizontal ridge dimensional changes that are associated with tooth extraction. It also provides an overview of the advantages of ridge preservation as well as grafting materials. A Medline search among English language papers was performed in March 2015 using alveolar ridge preservation, ridge augmentation, and various graft types as search terms. Additional papers were considered following the preliminary review of the initial search that were relevant to alveolar ridge preservation. The literature suggests that ridge preservation methods and augmentation techniques are available to minimize and restore available bone. Numerous grafting materials, such as autografts, allografts, xenografts, and alloplasts, currently are used for ridge preservation. Other materials, such as growth factors, also can be used to enhance biologic outcome. PMID:26262646

  10. [Chickenpox, burns and grafts].

    Science.gov (United States)

    Rojas Zegers, J; Fidel Avendaño, L

    1979-01-01

    An outbreak of chickenpox that occurred at the Burns Repair Surgery Unit, Department of Children's Surgery, Hospital R. del Río, between June and November, 1975, is reported. 27 cases of burned children were studied, including analysis of correlations of the stages and outcome of the disease (varicela), the trauma (burns) and the graft (repair surgery). As a result, the authors emphasize the following findings: 1. Burns and their repair are not aggravating factors for varicella. In a small number of cases the exanthema looked more confluent in the graft surgical areas and in the first degree burns healing spontaneously. 2. Usually there was an uneventful outcome of graft repair surgery on a varicella patient, either during the incubation period, the acme or the convalescence. 3. The fact that the outmost intensity of secondary viremia of varicella occurs before the onset of exanthemia, that is, during the late incubation period, is confirmed.

  11. Preparation of poly (vinyl alcohol) membranes grafted with n-vinyl pyridine/ acrylic acid binary monomers

    International Nuclear Information System (INIS)

    Ajji, A.; Ali, A.

    2014-03-01

    Poly(vinyl alcohol) films were grafted with two monomers using gamma radiation, acrylic acid and N-vinyl pyridine. The influence of different parameters on the grafting yield was investigated as: the comonomer concentration and composition, and irradiation dose. The suitable conditions of the process had been determined to prepare PVA membranes have both properties of the two monomers, acrylic acid and vinyl pyridine as comonomer concentration and composition, and irradiation dose. Some properties of the membranes had been investigated as maximum swelling and grafting. Also the ability of the grafted films to adsorb some heavy metals and dyes was elaborated and discussed.(author)

  12. Arteriovenous shunt graft ulceration with sinus and graft epithelialization

    Directory of Open Access Journals (Sweden)

    Pooja Singhal

    2015-03-01

    Full Text Available Arteriovenous fistula and grafts are used as access sites for patients with chronic kidney disease and are prone for complications. Stent grafts are used to treat access site complications. We report a rare and unusual finding of epithelialization of the sinus tract and the lumen of a polytetrafluoroethylene graft, following ulceration of the overlying skin.

  13. Improvement of Microwave Absorbance of Polymer Composites of W-Type Hexaferrite Powders by Attachment of Frequency Selective Surface

    Directory of Open Access Journals (Sweden)

    Cho H.-S.

    2017-06-01

    Full Text Available This work investigates the effect of a frequency selective surface (FSS composed of a regular array of square loop elements on the absorption properties of grounded ferrite composites. Polymer matrix composites of CoZnW hexaferrite powders having small magnetic loss were used as the substrate material. Computational tools were used to model the interaction between electromagnetic waves and materials and determine the reflection coefficient. Reflection loss and bandwidth were greatly improved by attaching an FSS with controlled electrical resistance (R onto the grounded ferrite composites. For the FSS with R = 800 Ω, the minimum reflection loss decreased to −25 dB at 10 GHz and the bandwidth was broadened to 7.5-12.5 GHz with respect to −10 dB reflection loss.

  14. Global DNA methylation changes in Cucurbitaceae inter-species grafting

    Directory of Open Access Journals (Sweden)

    Evangelia Avramidou

    2015-04-01

    Full Text Available Grafting has been used to improve yield, fruit quality and disease resistance in a range of tree and vegetable species. The molecular mechanisms underpinning grafting responses have only recently started to be delineated. One of those mechanisms involves long distance transfer of genetic material from rootstock to scion alluding to an epigenetic component to the grafting process. In the research presented herein we extended published work on heritable changes in the DNA methylation pattern of Solanaceae scion genomes, in Cucurbitaceae inter-species grafting. Specifically, we examined global DNA methylation changes in scions of cucumber, melon and watermelon heterografted onto pumpkin rootstocks using MSAP analysis. We observed a significant increase of global DNA methylation in cucumber and melon scions pointing to an epigenetic effect in Cucurbitaceae heterografting. Exploitation of differential epigenetic marking in different rootstock-scion combinations could lead to development of epi-molecular markers for generation and selection of superior quality grafted vegetables.

  15. Preparation of adsorbent for palladium ions by grafting of acrylonitrile and itaconic acid onto polypropylene nonwoven fabrics

    International Nuclear Information System (INIS)

    Zu Jianhua; Yan Feng; Luo Wenyun; Xia Min

    2010-01-01

    A new chelating fabrics are synthesized by radiation induced grafting of acrylonitrile (AN) and itaconic acid (IA) onto polypropylene nonwoven fabrics (PP fabrics) and subsequent conversion of cyano and carboxyl to an imine by reaction with ethylene diimine (EDA) or phenylhydrazine (PH). The effects of graft polymerization conditions such as Mohr,s salt concentration and co-monomer composition on grafting were investigated. At last, the optimum grafting and adsorption conditions were established. (authors)

  16. Composition

    DEFF Research Database (Denmark)

    Bergstrøm-Nielsen, Carl

    2014-01-01

    Cue Rondo is an open composition to be realised by improvising musicians. See more about my composition practise in the entry "Composition - General Introduction". Caution: streaming the sound/video files will in some cases only provide a few minutes' sample, or the visuals will not appear at all....... Please DOWNLOAD them to see/hear them in full length! This work is licensed under a Creative Commons "by-nc" License. You may for non-commercial purposes use and distribute it, performance instructions as well as specially designated recordings, as long as the author is mentioned. Please see http...

  17. Selective generation of laser-induced periodic surface structures on Al2O3-ZrO2-Nb composites

    Science.gov (United States)

    Kunz, Clemens; Bartolomé, José F.; Gnecco, Enrico; Müller, Frank A.; Gräf, Stephan

    2018-03-01

    Laser-induced periodic surface structures (LIPSS) were selectively fabricated on the metal phase of Al2O3-nZrO2-Nb (78.3-1.7-20 vol.%) ceramic matrix composites. For this purpose, sample surfaces were irradiated with fs-laser pulses (τ = 300 fs, λ = 1025 nm) of different laser peak fluences ranging from 0.23 to 0.40 J/cm2. The structured surfaces were characterised by scanning electron microscopy (SEM), atomic force microscopy (AFM), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), and by measuring the water contact angle. Well-pronounced LIPSS with a period of Λ ≈ 750 nm and a height of h ≈ 263 nm were found solely on the metal phase of the composite when applying the highest fluence whereas no structural and chemical modifications were found on the surface of the ceramic matrix. This can be explained by the different light absorption behaviour of both phases, which results in different ablation thresholds. The water contact angle of composite surfaces was successfully reduced from 68.4° for untreated samples to 40.9° for structured samples. Selectively structured composites with adjustable wettability are of particular interest for biomedical and tribological applications.

  18. Enhanced treatment selection for reflective joint cracking in composite pavements : final report.

    Science.gov (United States)

    2015-09-01

    This research developed a decisionmaking process that can be used by INDOT to enhance identification of the condition of the : underlying concrete joints or cracks by looking at the surface distresses of the asphalt overlay in composite pavements....

  19. Graft nephrectomy: The SGPGI experience

    OpenAIRE

    Nand Kishore Arvind; Aneesh Srivastava; Anant Kumar; Subodh K Das

    2002-01-01

    Background: Graft nephrectomy is often considered a hazardous procedure with high morbidity and occasional mortality, and this may pose a technical challenge. The aim of this study was to evaluate the indications, etiology and complications following graft nephrectomy. Materials and Methods: From 1988 to 2001, among total of 1,019 live related renal transplants carried at our center, 46 underwent graft nephrectomy. Patients were divided into 2 groups depending on timing of graft re-mova...

  20. The use of stable isotope compositions of selected elements in food origin control

    International Nuclear Information System (INIS)

    Wierzchnicki, R.

    2002-01-01

    Stable isotope ratios have been used widely for authentication of foodstuffs especially for detection of added water and sugar in fruit juices and wines. Hydrogen and oxygen composition are particularly interesting probes for geographical origin and authenticity identification. Carbon and nitrogen composition of fruits contains the finger-print of their metabolism and growing condition. Exemplary data are presented which demonstrated the usefulness of the Isotope Ratio Mass Spectrometry (IRMS) methods for authenticating wines and fruits (juice and pulp). (author)

  1. Phase selection controlled by sodium ions in the synthesis of FAU/LTA composite zeolite

    Directory of Open Access Journals (Sweden)

    Linyan Hu, Sujuan Xie, Qingxia Wang, Shenglin Liu and Longya Xu

    2009-01-01

    Full Text Available Zeolite faujasite (FAU, Linde type A (LTA and FAU/LTA composite have been synthesized using tetramethylammonium cation (TMA + as template, by adjusting only the concentration of Na + ions in the initial solution (1.00 Al2 O3 4.36 SiO2 : 2.39 (TMA2 O : β Na2 O : 249.00H2 O. Na + ions alter the phase composition of the product more than TMA+ or OH− ions. When Na2 O concentration [Na2 O] increases from 0.024 to 0.168, the product gradually changes from pure FAU to pure LTA via the formation of FAU/LTA composite with increasing LTA fraction. Interestingly, the induction periods of FAU and LTA in the FAU/LTA composite zeolite ([Na2 O] is 0.072 are both 13 h, quite different from the induction periods of their individual pure phases—45 h for FAU and 4 h for LTA. During the crystallization, the LTA/(FAU + LTA fraction in the composite zeolite decreases in a nearly linear fashion. Scanning electron microscopy, thermogravimetry and differential thermal analysis indicate some difference between the properties of the FAU/LTA composite zeolite and of the mechanical mixture.

  2. Haemodynamics in axillobifemoral bypass grafts

    NARCIS (Netherlands)

    C.H. Wittens

    1992-01-01

    textabstractThis thesis is based on four publications on the subject of graft configuration and haemodynamics in axillobifemoral bypass grafts: 1. A clinical evaluation of 17 patients with axillobifemoral bypass graft operations, performed for various indications. Two important observations were

  3. Influence of Selectively Localised Nanoclay Particles on Non-Isothermal Crystallisation and Degradation Behaviour of PP/LDPE Blend Composites

    Directory of Open Access Journals (Sweden)

    Tladi Gideon Mofokeng

    2018-02-01

    Full Text Available In immiscible polymer blend nanocomposites, nanoparticles can be localised either in polymer matrices or at the interface, invoking the simple question of how the spatial distribution of the nanoparticles and the resulting morphological changes affect the non-isothermal crystallisation and degradation kinetics. In this study, the non-isothermal crystallisation of polypropylene in polypropylene (PP-rich compatibilised and non-compatibilised PP/low-density polyethylene (LDPE/clay composites and their degradation are investigated. The non-isothermal crystallisation analyses show that the localisation of the clay particles in the blend composites has two opposing effects. First, the poorly dispersed clay particles at the PP/LDPE interface in the non-compatibilised blend composite has no significant effect on the crystallisation temperature of PP but allows the free movement of PP chains, resulting in a higher crystallinity of PP than that of PP in the neat blend. Second, the well-dispersed clay particles in the compatibilised blend composites disrupt the free movement of PP chains, resulting in a lower crystallisation temperature and crystallinity than that of PP in the neat blend. The influences of different selective localisations of clay particles on the activation energies of degradation are studied. The presence of maleated compatibilisers, clay, and the distribution of clay in the blend composite play important roles in determining the activation energies of degradation.

  4. Surface modification of cellulose by PCL grafts

    International Nuclear Information System (INIS)

    Paquet, Olivier; Krouit, Mohammed; Bras, Julien; Thielemans, Wim; Belgacem, Mohamed Naceur

    2010-01-01

    Two cellulosic substrates (microcrystalline cellulose, MCC, and bleached kraft softwood pulps, BSK) were grafted by polycaprolactone (PCL) chains with different molecular weights, following a three-step procedure using non-swelling conditions in order to limit the reaction to their surface. First, one of the two OH PCL ends was blocked by phenyl isocyanate and the reaction product (adduct 1) was subsequently reacted with 2,4-toluene diisocyanate (adduct 2) to provide it with an NCO function, capable of reacting with cellulose. The ensuing PCL-grafted cellulosic materials were characterized by weight gain, elemental analysis, contact angle measurements, attenuated total reflexion-Fourier transform infrared (ATR-FTIR), X-ray photoelectron spectroscopy (XPS) and biodegradation tests. The modification was proven to occur by the presence of nitrogen atoms in the elemental analysis tests and XPS spectra of modified and soxhlet-extracted cellulose. The contact angle measurements have also shown that the surface became as hydrophobic as PCL itself. The polar component of the surface energy of cellulosic substrates before treatment was found to be about 32 and 10 mJ m -2 , for MCC and BSK, respectively. This value vanished to practically zero after grafting with different PCLs. The strategy proposed in the present work is original since, to the best of our knowledge, this paper reports for the first time the chemical 'grafting onto' of the cellulose surface by PCL macromolecular structures, with the aim of obtaining fibre-matrix co-continuous fully sustainable and biodegradable composite materials.

  5. Acrylonitrile grafted to PVDF

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jin; Eitouni, Hany Basam

    2015-03-31

    PVDF-g-PAN has been synthesized by grafting polyacrylonitrile onto polyvinylidene fluoride using an ATRP/AGET method. The novel polymer is ionically conducive and has much more flexibility than PVDF alone, making it especially useful either as a binder in battery cell electrodes or as a polymer electrolyte in a battery cell.

  6. Aortic Graft Infection Secondary to Iatrogenic Transcolonic Graft Malposition.

    Science.gov (United States)

    Blank, Jacqueline J; Rothstein, Abby E; Lee, Cheong Jun; Malinowski, Michael J; Lewis, Brian D; Ridolfi, Timothy J; Otterson, Mary F

    2018-01-01

    Aortic graft infections are a rare but devastating complication of aortic revascularization. Often infections occur due to contamination at the time of surgery. Iatrogenic misplacement of the limbs of an aortobifemoral graft is exceedingly rare, and principles of evaluation and treatment are not well defined. We report 2 cases of aortobifemoral bypass graft malposition through the colon. Case 1 is a 54-year-old male who underwent aortobifemoral bypass grafting for acute limb ischemia. He had previously undergone a partial sigmoid colectomy for diverticulitis. Approximately 6 months after vascular surgery, he presented with an occult graft infection. Preoperative imaging and intraoperative findings were consistent with graft placement through the sigmoid colon. Case 2 is a 60-year-old male who underwent aortobifemoral bypass grafting due to a nonhealing wound after toe amputation. His postoperative course was complicated by pneumonia, bacteremia thought to be secondary to the pneumonia, general malaise, and persistent fevers. Approximately 10 weeks after the vascular surgery, he presented with imaging and intraoperative findings of graft malposition through the cecum. Aortic graft infection is usually caused by surgical contamination and presents as an indolent infection. Case 1 presented as such; Case 2 presented more acutely. Both grafts were iatrogenically misplaced through the colon at the index operation. The patients underwent extra-anatomic bypass and graft explantation and subsequently recovered.

  7. Novel Protic Ionic Liquid Composite Membranes with Fast and Selective Gas Transport Nanochannels for Ethylene/Ethane Separation.

    Science.gov (United States)

    Dou, Haozhen; Jiang, Bin; Xiao, Xiaoming; Xu, Mi; Tantai, Xiaowei; Wang, Baoyu; Sun, Yongli; Zhang, Luhong

    2018-04-25

    Protic ionic liquids (PILs) were utilized for the fabrication of composite membranes containing silver salt as the C 2 H 4 transport carrier to perform C 2 H 4 /C 2 H 6 separation for the first time. The intrinsic nanostructures of PILs were adopted to construct fast and selective C 2 H 4 transport nanochannels. The investigation of structure-performance relationships of composite membranes suggested that transport nanochannels (polar domains of PILs) could be tuned by the sizes of cations, which greatly manipulated activity of the carrier and determined the separation performances of membranes. The role of different carriers in the facilitated transport was studied, which revealed that the PILs were good solvents for dissolution and activation of the carrier due to their hydrogen bond networks and waterlike properties. The operating conditions of separation process were investigated systemically and optimized, confirming C 2 H 4 /C 2 H 6 selectivity was enhanced with the increase of silver salt concentration, the flow rate of sweep gas, and the feed ratio of C 2 H 4 to C 2 H 6 , as well as the decrease of the transmembrane pressure and operating temperature. Furthermore, the composite membranes exhibited long-term stability and obtained very competitive separation performances compared with other results. In summary, PIL composite membranes, which possess good long-term stability, high C 2 H 4 /C 2 H 6 selectivity, and excellent C 2 H 4 permeability, may have a good perspective in industrial C 2 H 4 /C 2 H 6 separation.

  8. Dynamic Characters of Stiffened Composite Conoidal Shell Roofs with Cutouts: Design Aids and Selection Guidelines

    Directory of Open Access Journals (Sweden)

    Sarmila Sahoo

    2013-01-01

    Full Text Available Dynamic characteristics of stiffened composite conoidal shells with cutout are analyzed in terms of the natural frequency and mode shapes. A finite element code is developed for the purpose by combining an eight-noded curved shell element with a three-noded curved beam element. The code is validated by solving benchmark problems available in the literature and comparing the results. The size of the cutouts and their positions with respect to the shell centre are varied for different edge constraints of cross-ply and angle-ply laminated composite conoids. The effects of these parametric variations on the fundamental frequencies and mode shapes are considered in details. The results furnished here may be readily used by practicing engineers dealing with stiffened composite conoids with cutouts central or eccentric.

  9. Characterization of adipose tissue for autologous fat grafting.

    Science.gov (United States)

    Suszynski, Thomas M; Sieber, David A; Van Beek, Allen L; Cunningham, Bruce L

    2015-02-01

    Fat grafting is a common procedure in aesthetic and reconstructive plastic surgery, but variable graft retention limits its utility. Unpredictable clinical outcomes with fat grafting can be explained in part by the lack of standardized protocols for harvesting, processing, and transplanting adipose tissue (AT). Historically, plastic surgeons have relied on trial and error and their clinical experience to develop fat grafting protocols. Optimization of fat grafting protocols requires systematic assessment of the impact that key variables have on the quality of the AT preparation at each step of the procedure. In this article, we review recent findings regarding the composition and quality of AT prepared for fat grafting and the strengths and limitations of existing AT characterization assays. We discuss the need for an assessment of the viability of intact AT (ie, conventionally harvested AT that has not been disrupted further) by means of an operator-independent, quantitative assay that can be performed in real time and generates reproducible data. Promising assays for the characterization of cell product quality have been developed for other therapeutic applications, such as transplantation of pancreatic islet cells. The development or adaptation of a gold-standard assay to determine the quality of an AT preparation may help to standardize fat grafting protocols and improve clinical outcomes. © 2015 The American Society for Aesthetic Plastic Surgery, Inc. Reprints and permission: journals.permissions@oup.com.

  10. Sulfonated Poly(styrene) Chains Grafted on Magnetic Nanoparticles

    Science.gov (United States)

    Jiao, Yang; Yevelev, Anton; Parra, Javier; Akcora, Pinar; Stevens Institute of Technology Team

    2014-03-01

    Iron oxide nanoparticles functionalized with poly(styrene) (PS) chains at various grafting densities and loadings present stable and ordered nanostructures for tuning the mechanical and conductive properties in polymer composites. Strings, spherical and anisotropic clusters and well-dispersed particles are achieved with PS-grafted Fe3O4 nanoparticles in PS matrices upon varying the system parameters. In this work, we report the effect of sulfonic group locations on the aggregation state of polymer-grafted nanoparticles. Structures formed by the random and diblock copolymers of PS-poly(styrene sulfonate) (PSS) grafted particles will be discussed with small-angle x-ray scattering (SAXS) measurements in solution and melts. The conformational changes in PS-grafted chains and ion-containing grafts will be also presented in small-angle neutron-scattering (SANS) results to understand the role of polymer on the assembly of particles at the low grafting density. We acknowledge support by NSF-CAREER-DMR (#1048865).

  11. Synthesis of polycaprolactone-grafted microfibrillated cellulose for use in novel bionanocomposites--influence of the graft length on the mechanical properties.

    Science.gov (United States)

    Lönnberg, Hanna; Larsson, Karolina; Lindström, Tom; Hult, Anders; Malmström, Eva

    2011-05-01

    In the present work, microfibrillated cellulose (MFC) made from bleached sulfite softwood dissolving pulp was utilized to reinforce a poly(ε-caprolactone) (PCL) biopolymer matrix. To improve the dispersibility of the hydrophilic MFC in the nonpolar matrix and the interfacial adhesion in the composite material, we covalently grafted the MFC with PCL via ring-opening polymerization (ROP) of ε-caprolactone (ε-CL). To be able to investigate the effect of the PCL graft length on the mechanical properties of the composite material, we performed ROP to different molecular weights of the grafts. Bionanocomposites containing 0, 3, and 10 wt % MFC were prepared via hot pressing using both unmodified and PCL grafted MFC (MFC-g-PCL) as reinforcement. PCL grafting resulted in improved dispersion of the MFC in a nonpolar solvent and in the PCL matrix. The mechanical testing of the biocomposites showed an improvement in the mechanical properties for the PCL grafted MFC in comparison to ungrafted MFC. It was also shown that there was an impact on the mechanical properties with respect to the PCL graft lengths, and the strongest biocomposites were obtained after reinforcement with MFC grafted with the longest PCL graft length.

  12. A simple route to Develop Highly porous Nano Polypyrrole/Reduced Graphene Oxide Composite film for Selective Determination of Dopamine

    International Nuclear Information System (INIS)

    Daniel Arulraj, Abraham; Arunkumar, Arumugam; Vijayan, Muthunanthevar; Balaji Viswanath, Kamatchirajan; Vasantha, Vairathevar Sivasamy

    2016-01-01

    A highly selective sensor was developed for dopamine with electrochemically treated sodium dodecyl benzene sulfonate doped nano polypyrrole (ET-SDBS-NPPy)/reduced graphene oxide (RGO) film. First, graphene oxide (GO) was reduced on the electrode surface electrochemically and then, SDBS-NPPy film was polymerized electrochemically on the ERGO coated GCE and bare GCE also. The SDBS-NPPy/ERGO and SDBS-NPPy films were treated electrochemically in phosphate buffer solution to replace macro SDBS- anions by smaller phosphate anions. Then, the physical properties of the above composite films were characterized by scanning electron microscope (SEM) and water wettability test. The replacement of SDBS- anions by phosphate anions leaves porous structure in the polymer films and also increases the hydrophobicity in the films. Then, these composite films were applied for the determination of dopamine in the presence of ascorbic acid and uric acid. Under the optimal conditions, the linear range for dopamine detection is 0.1 μM-100.0 μM with the detection limit of 20 nM at S/N = 3. Generally, conducting polypyrrole film could sense ascorbic acid and dopamine simultaneously. However, we have proposed a simple route to synthesis a porous and hydrophobic polypyrrole composite film for selective determination of dopamine in the presence of higher concentration (five orders) of ascorbic acid and uric acid.

  13. [Energy dispersive spectrum analysis of surface compositions of selective laser melting cobalt-chromium alloy fabricated by different processing parameters].

    Science.gov (United States)

    Qian, Liang; Zeng, Li; Wei, Bin; Gong, Yao

    2015-06-01

    To fabricate selective laser melting cobalt-chromium alloy samples by different processing parameters, and to analyze the changes of energy dispersive spectrum(EDS) on their surface. Nine groups were set up by orthogonal experimental design according to different laser powers,scanning speeds and powder feeding rates(laser power:2500-3000 W, scanning speed: 5-15 mm/s, powder feeding rate: 3-6 r/min). Three cylinder specimens(10 mm in diameter and 3 mm in thickness) were fabricated in each group through Rofin DL 035Q laser cladding system using cobalt-chromium alloy powders which were developed independently by our group.Their surface compositions were then measured by EDS analysis. Results of EDS analysis of the 9 groups fabricated by different processing parameters(Co:62.98%-67.13%,Cr:25.56%-28.50%,Si:0.49%-1.23%) were obtained. They were similar to the compositions of cobalt-chromium alloy used in dental practice. According to EDS results, the surface compositions of the selective laser melting cobalt-chromium alloy samples are stable and controllable, which help us gain a preliminary sight into the range of SLM processing parameters. Supported by "973" Program (2012CB910401) and Research Fund of Science and Technology Committee of Shanghai Municipality (12441903001 and 13140902701).

  14. Composite magnetic refrigerants for an Ericsson cycle: New method of selection using a numerical approach

    International Nuclear Information System (INIS)

    Smaieli, A.; Chahine, R.

    1997-01-01

    The efficient operation of an Ericsson cycle requires the magnetic entropy change (AS) be constant as a function of temperature. To realize this condition using composite materials, a numerical method has been developed to determine the optimum proportions of the components. The Gd x Er 1-x (x = 0.69, 0.90) alloys have been used to investigate the validity of the numerical method. The values of ΔS have been determined from experimental magnetization curves of these alloys, in the 0.1-9 T magnetic field and the 200-290 K range. The calculations have led to the mass ratio y = 0.56 for the composite (Gd 0.90 Er 0.10 ) y (Gd 0.69 Er 0.31 ) 1-y . The ΔS of this composite is fairly constant in the 225-280 K range. To confirm this result, the magnetization curves of the composite material have been determined experimentally, and the corresponding ΔS was compared with the one predicted numerically. A good agreement was found proving the method's ability to properly determine the required fractions of the refrigerant's constituent materials

  15. Elemental, mineralogical, and pore-solution compositions of selected Canadian clays

    International Nuclear Information System (INIS)

    Oscarson, D.W.; Dixon, D.A.

    1989-03-01

    Clay materials will be an important component of a barrier and sealing system in a nuclear fuel waste disposal vault in Canada. In this report the elemental, mineralogical, and pore-solution compositions of candidate clay sealing materials for the Canadian Nuclear Fuel Waste Management Program are presented

  16. Nutrient composition of selected newly bred and established mung bean varieties

    NARCIS (Netherlands)

    Dahiya, P.K.; Linnemann, A.R.; Nout, M.J.R.; Boekel, van M.A.J.S.; Grewal, R.B.

    2013-01-01

    Seven newly bred and three established varieties of mung bean were analysed for proximate composition, minerals, anti-nutrients and in vitro mineral accessibility. They contained 18–23 g protein, 4.0–5.6 g crude fibre and 2.5–4.1 g ash per 100 g dry sample. Iron, zinc, calcium, sodium and potassium

  17. Synthesis of magnetic graphene/mesoporous silica composites with boronic acid-functionalized pore-walls for selective and efficient residue analysis of aminoglycosides in milk.

    Science.gov (United States)

    Feng, Jianan; She, Xiaojian; He, Xinying; Zhu, Jinglin; Li, Yan; Deng, Chunhui

    2018-01-15

    In this study, magnetic graphene/mesoporous silica composites with boronic acid-functionalized pore-walls were synthesized for the first time by a two-step post-graft method. The obtained nano-composites were proven to hold many attractive features such as large specific surface area, uniform mesopores, high magnetic responsibility, and boronic acid-functionalized inner pore-walls. Aminoglycoside residues in milk were extracted using MG@mSiO 2 -APB composites as restricted access matrix dispersive solid phase extraction adsorbents through the interaction between boronic acid groups and glucoside structures. Extraction conditions were optimized by studying the SPE parameters. Limits of detection of the method were as low as 5ngmL -1 for streptomycin) and 2ngmL -1 for dihydrostreptomycin. Finally, magnetic graphene/mesoporous silica composites with boronic acid-functionalized pore-walls were successfully applied to residue analysis in milk samples. Compared to the traditional extraction methods, using this nano-composites for aminoglycoside residues analysis in milk is more sensitive, effective and convenient. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Composition.

    Science.gov (United States)

    Communication: Journalism Education Today, 2002

    2002-01-01

    Considers how photography is more than just pointing a camera in the right direction. Explains that good pictures use elements of composition such as the Rule of Thirds, leading lines, framing and repetition of shapes. Presents 16 photographs from college and secondary school publications, and describes the techniques that makes them effective.…

  19. Grafting: a technique to modify ion accumulation in horticultural crops

    Directory of Open Access Journals (Sweden)

    Muhammad Azher Nawaz

    2016-10-01

    Full Text Available Grafting is a centuries-old technique used in plants to obtain economic benefits. Grafting increases nutrient uptake and utilization efficiency in a number of plant species, including fruits, vegetables, and ornamentals. Selected rootstocks of the same species or close relatives are utilized in grafting. Rootstocks absorb more water and ions than self-rooted plants and transport these water and ions to the aboveground scion. Ion uptake is regulated by a complex communication mechanism between the scion and rootstock. Sugars, hormones, and miRNAs function as long-distance signaling molecules and regulate ion uptake and ion homeostasis by affecting the activity of ion transporters. This review summarizes available information on the effect of rootstock on nutrient uptake and utilization and the mechanisms involved. Information on specific nutrient-efficient rootstocks for different crops of commercial importance is also provided. Several other important approaches, such as interstocking (during double grafting, inarching, use of plant-growth-promoting rhizobacteria, use of arbuscular mycorrhizal fungi, use of plant growth substances (e.g., auxin and melatonin, and use of genetically engineered rootstocks and scions (transgrafting, are highlighted; these approaches can be combined with grafting to enhance nutrient uptake and utilization in commercially important plant species. Whether the rootstock and scion affect each other’s soil microbiota and their effect on the nutrient absorption of rootstocks remain largely unknown. Similarly, the physiological and molecular bases of grafting, crease formation, and incompatibility are not fully identified and require investigation. Grafting in horticultural crops can help reveal the basic biology of grafting, the reasons for incompatibility, sensing, and signaling of nutrients, ion uptake and transport, and the mechanism of heavy metal accumulation and restriction in rootstocks. Ion transporter and mi

  20. Grafting improves cucumber water stress tolerance in Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Abdulaziz R. Al-Harbi

    2018-02-01

    Full Text Available Water scarcity is a major limiting factor for crop productivity in arid and semi-arid areas. Grafting elite commercial cultivars onto selected vigorous rootstocks is considered as a useful strategy to alleviate the impact of environmental stresses. This study aims to investigate the feasibility of using grafting to improve fruit yield and quality of cucumber under water stress conditions. Alosama F1 cucumber cultivar (Cucumis sativus L. was grafted onto Affyne (Cucumis sativus L. and Shintoza A90 (Cucurbitamaxima × C. moschata rootstocks. Non-grafted plants were used as control. All genotypes were grown under three surface drip irrigation regimes: 50%, 75% and 100% of the crop evapotranspiration (ETc, which represent high-water stress, moderate-water stress and non-water stress conditions, respectively. Yield and fruit quality traits were analyzed and assessed. In comparison to the non-grafted plants, the best grafting treatment under water stress was Alosama F1 grafted onto Shintoza A90 rootstock. It had an overall improved yield and fruit quality under water stress owing to an increase in the total fruit yield by 27%, from 4.815 kg plant−1 in non-grafted treatment to 6.149 kg plant−1 in grafted treatment under moderate -water stress, total soluble solid contents (13%, titratable acidity (39% and vitamin C (33%. The soil water contents were low in soil surface and increase gradually with soil depth, while salt distribution showed an adverse trend. The positive effects of grafting on plant growth, productivity, and water use efficiency support this strategy as an useful tool for improving water stress tolerance in greenhouse grown cucumber in Saudi Arabia.

  1. The Effect of Carbon Nanotubes on the Mechanical Properties of Wood Plastic Composites by Selective Laser Sintering

    Directory of Open Access Journals (Sweden)

    Yunhe Zhang

    2017-12-01

    Full Text Available Wood-plastic composites (WPCs made by selective laser sintering (SLS approach of 3D printing offer many advantages over single polymer materials, such as low cost, sustainability, and better sintering accuracy. However, WPCs made via SLS are too weak to have widespread applications. In order to increase the mechanical properties of WPCs, a novel type of WPCs containing 0, 0.05, 0.1 and 0.15 wt % carbon nanotubes (CNT, 14 wt % wood fibers, 86 wt % polyether sulfone (PES was manufactured via SLS. The experimental results showed that the addition of small amount of CNTs can significantly increase the mechanical properties of the wood/PES composite material. The tensile strength, bending strength, and elasticity modulus were 76.3%, 227.9%, and 128.7% higher with 0.1 wt % CNTs than those without CNTs. The mechanical properties of specimens first increased and then decreased with the addition of CNTs. The SEM results of the specimens’ fracture morphology indicate that the preferable bonding interfaces between wood flour grains and PES grains were achieved by adding CNTs to the composites. There are two reasons why the composites possessed superior mechanical properties: CNTs facilitate the laser sintering process of WPCs due to their thermal conductivities, and CNTs directly reinforce WPCs.

  2. Selection for silage yield and composition did not affect genomic diversity within the Wisconsin Quality Synthetic maize population.

    Science.gov (United States)

    Lorenz, Aaron J; Beissinger, Timothy M; Silva, Renato Rodrigues; de Leon, Natalia

    2015-02-02

    Maize silage is forage of high quality and yield, and represents the second most important use of maize in the United States. The Wisconsin Quality Synthetic (WQS) maize population has undergone five cycles of recurrent selection for silage yield and composition, resulting in a genetically improved population. The application of high-density molecular markers allows breeders and geneticists to identify important loci through association analysis and selection mapping, as well as to monitor changes in the distribution of genetic diversity across the genome. The objectives of this study were to identify loci controlling variation for maize silage traits through association analysis and the assessment of selection signatures and to describe changes in the genomic distribution of gene diversity through selection and genetic drift in the WQS recurrent selection program. We failed to find any significant marker-trait associations using the historical phenotypic data from WQS breeding trials combined with 17,719 high-quality, informative single nucleotide polymorphisms. Likewise, no strong genomic signatures were left by selection on silage yield and quality in the WQS despite genetic gain for these traits. These results could be due to the genetic complexity underlying these traits, or the role of selection on standing genetic variation. Variation in loss of diversity through drift was observed across the genome. Some large regions experienced much greater loss in diversity than what is expected, suggesting limited recombination combined with small populations in recurrent selection programs could easily lead to fixation of large swaths of the genome. Copyright © 2015 Lorenz et al.

  3. Graft Copolymerization of Methyl Methacrylate Monomer onto Starch and Natural Rubber Latex Initiated by Gamma Irradiation

    Directory of Open Access Journals (Sweden)

    S. Iskandar

    2011-04-01

    Full Text Available To obtain the degradable plastic, the graft copolymerization of methyl methacrylate onto starch and natural rubber latex was conducted by a simultaneous irradiation technique. Gamma-ray from cobalt-60 source was used as the initiator. The grafted copolymer of starch-polymethyl methacrylate and the grafted copolymer of natural rubber-polymethyl methacrylate were mixed in the blender, and dried it in the oven. The dried grafted copolymer mixture was then molded using hydraulic press machine. The effect of irradiation dose, composition of the grafted copolymer mixture, film forming condition and recycle effect was evaluated. The parameters observed were tensile strength, gel fraction and soil burial degradability of grafted copolymer mixture. It was found that the tensile strength of grafted copolymer mixture increased by -ray irradiation. Increasing of the grafted copolymer of natural rubber-polymethyl methacrylate content, the gel fraction and tensile strength of the grafted copolymer mixture increased. The tensile strength of the grafted copolymer mixture was increased from 18 MPa to 23 MPa after recycled (film forming reprocessed 3 times. The grafted copolymer mixture was degraded completely after soil buried for 6 months

  4. RESULTS OF THE SELECTION OF BREEDING SAMPLES OF CARROT BASED ON BIOCHEMICAL COMPOSITION

    OpenAIRE

    V. K. Cherkasova; O. N. Shabetya

    2014-01-01

    12 samples of carrot were analyzed for biochemical components in roots. 5 genotypes with high content of vitamin C, β-carotene, and total sugar were selected as genetic sources of high biochemical components.

  5. Partial relay selection based on shadowing side information over generalized composite fading channels

    KAUST Repository

    Yilmaz, Ferkan

    2011-11-01

    In this paper, in contrast to the relay selection protocols available in the literature, we propose a partial relay selection protocol utilizing only the shadowing side information of the relays instead of their full channel side information in order to select a relay in a dual-hop relaying system through the available limited feedback channels and power budget. We then presented an exact unified performance expression combining the average bit error probability, ergodic capacity, and moments-generating function of the proposed partial relay selection over generalized fading channels. Referring to the unified performance expression introduced in [1], we explicitly offer a generic unified performance expression that can be easily calculated and that is applicable to a wide variety of fading scenarios. Finally, as an illustration of the mathematical formalism, some numerical and simulation results are generated for an extended generalized-K fading environment, and these numerical and simulation results are shown to be in perfect agreement. © 2011 IEEE.

  6. Highly Selective and Stable Reduction of CO2 to CO by a Graphitic Carbon Nitride/Carbon Nanotube Composite Electrocatalyst.

    Science.gov (United States)

    Lu, Xunyu; Tan, Tze Hao; Ng, Yun Hau; Amal, Rose

    2016-08-16

    A stable and selective electrocatalyst for CO2 reduction was fabricated by covalently attaching graphitic carbon nitride onto multiwall carbon nanotubes (g-C3 N4 /MWCNTs). The as-prepared composite is able to reduce CO2 exclusively to CO with a maximum Faraday efficiency of 60 %, and no decay in the catalytic activity was observed even after 50 h of reaction. The enhanced catalytic activity towards CO2 reduction is attributed to the formation of active carbon-nitrogen bonds, high specific surface area, and improved material conductivity of the g-C3 N4 /MWCNT composite. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Toward hypoxia-selective DNA-alkylating agents built by grafting nitrogen mustards onto the bioreductively activated, hypoxia-selective DNA-oxidizing agent 3-amino-1,2,4-benzotriazine 1,4-dioxide (tirapazamine).

    Science.gov (United States)

    Johnson, Kevin M; Parsons, Zachary D; Barnes, Charles L; Gates, Kent S

    2014-08-15

    Tirapazamine (3-amino-1,2,4-benzotriazine 1,4-dioxide) is a heterocyclic di-N-oxide that undergoes enzymatic deoxygenation selectively in the oxygen-poor (hypoxic) cells found in solid tumors to generate a mono-N-oxide metabolite. This work explored the idea that the electronic changes resulting from the metabolic deoxygenation of tirapazamine analogues might be exploited to activate a DNA-alkylating species selectively in hypoxic tissue. Toward this end, tirapazamine analogues bearing nitrogen mustard units were prepared. In the case of the tirapazamine analogue 18a bearing a nitrogen mustard unit at the 6-position, it was found that removal of the 4-oxide from the parent di-N-oxide to generate the mono-N-oxide analogue 17a did indeed cause a substantial increase in reactivity of the mustard unit, as measured by hydrolysis rates and DNA-alkylation yields. Hammett sigma values were measured to quantitatively assess the magnitude of the electronic changes induced by metabolic deoxygenation of the 3-amino-1,2,4-benzotriazine 1,4-dioxide heterocycle. The results provide evidence that the 1,2,4-benzotiazine 1,4-dioxide unit can serve as an oxygen-sensing prodrug platform for the selective unmasking of bioactive agents in hypoxic cells.

  8. Nutritional Composition of Fruits Selected by Long-Tailed Macaques (Macaca fascicularis) in Kuala Selangor, Malaysia.

    Science.gov (United States)

    Kassim, Norazila; Hambali, Kamarul; Amir, Aainaa

    2017-01-01

    Proximate analysis of twelve species of fruits commonly consumed by long-tailed macaques ( Macaca fascicularis ), i.e., Arenga pinnata , Areca catechu , Terminalia catappa , Elaeis guineensis , Lagerstroemia tomentosa , Mangifera indica , Cascabela thevetia , Muntingia calabura , Musa sp., Artocarpus heterophyllus , Ficus tinctoria ssp. gibbosa and Ficus microcarpa , was conducted with the specific objective to determine the nutritional composition of the foodstuffs of long-tailed macaques. The results showed the following order of nutrients: fibre, protein, fat and ash. Based on the results of the chemical analysis, the highest percentage of fibre content (52.7%), protein (9.9%), fat (77.2%) and ash (8.5%) were found in A. catechu , T. catappa , E. guineensis and C. thevetia , respectively. The nutrient composition of these twelve fruit species was found to differ (ANOVA test: crude protein, F (11,24) = 87.978, p catappa had the highest protein content, and the total mineral content was highest in C. thevetia .

  9. Periorbital fat grafting.

    Science.gov (United States)

    Massry, Guy G; Azizzadeh, Babak

    2013-02-01

    Periorbital aging is a multifactorial process involving volume loss (bone and soft tissue), tissue decent, and cutaneous degenerative changes. Traditional approaches to surgery on this area of the face have been subtractive in nature, focusing on excision of skin, muscle, and fat. This has frequently led to a gaunt or hollowed postoperative appearance. Contemporary aesthetic eyelid and periorbital rejuvenation has undergone a paradigm shift from an excisionally based surgical approach to one that prioritizes volume preservation and/or augmentation. The development of fat grafting to the eyelids and periorbita has given the eyelid surgeon a viable surgical alternative to prevent postoperative volume depletion, maintain the smooth transition of the lower eyelid to the cheek, and aid in restoring the youthful appearance desired after surgery. This article will focus of periorbital fat grafting and touch upon fat preservation techniques as primary restorative procedures or as surgical adjuncts. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  10. Voltammetric Determination of Selected Nitro Compounds at a Polished Silver Solid Amalgam Composite Electrode

    Czech Academy of Sciences Publication Activity Database

    Vyskočil, V.; Navrátil, Tomáš; Daňhel, A.; Dědík, J.; Krejčová, Z.; Škvorová, L.; Tvrdíková, J.; Barek, J.

    2011-01-01

    Roč. 23, č. 1 (2011), s. 129-139 ISSN 1040-0397. [International Conference on Electroanalysis (ESEAC 2010) /13./. Gijón, 20.06.2010-24.06.2010] R&D Projects: GA AV ČR IAA400400806 Institutional research plan: CEZ:AV0Z40400503 Keywords : voltammetry * silver solid amalgam composite electrode * drinking water Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.872, year: 2011

  11. [The fat content and fatty acids composition in selected products of the convenience food].

    Science.gov (United States)

    Drzewicka, Maria; Grajeta, Halina; Kleczkowski, Jerzy

    2012-01-01

    An increasing pace of life and a lack of time for meals preparation at home, observed in many countries worldwide, have led to an increased consumption of convenient food products. This term refers to highly processed food products that are either ready-to-eat or may be consumed after short culinary processing. Convenience foods include: dinner courses, salads, cereals, creams, broths, pizzas, roasts, as well as frozen products ready-to-eat after short heat treatment. The aim of this study was to assess the fat content and fatty acids composition of frozen products belonging to convenience food. Material for analysis comprised of 30 following food products: fish and seafood products, pizza, casseroles and meat products. The fat content was determined using Folch method and the fatty acids composition using gas chromatography technique. The analyzed products contained from 1.2% to 26.9% of fat. The saturated fatty acids (SFA) content ranged from 8.7% to 53.2%, while the monounsaturated fatty acids (MUFA)--from 24.0% to 68.7% of total fatty acids. The polyunsaturated fatty acids (PUFA) percentage accounted for 8,1% to 48,8% and trans isomers--for 0.2% to 6.1% of total fatty acids. The fat and fatty acid contents showed large differences in products depending on their composition and preparation techniques declared by the producer. Most of the analyzed fish and seafood products were characterized by the fat content ranged from 11% to 14% with the high percentage of fatty acids favorable from nutritional point of view, MUFA and PUFA. The composition of fatty acids from pizza and casseroles was less favorable, due to high proportion of SFA and also trans isomers.

  12. Role of selected polymorphisms in determining muscle fiber composition in Japanese men and women.

    Science.gov (United States)

    Kumagai, Hiroshi; Tobina, Takuro; Ichinoseki-Sekine, Noriko; Kakigi, Ryo; Tsuzuki, Takamasa; Zempo, Hirofumi; Shiose, Keisuke; Yoshimura, Eiichi; Kumahara, Hideaki; Ayabe, Makoto; Higaki, Yasuki; Yamada, Ryo; Kobayashi, Hiroyuki; Kiyonaga, Akira; Naito, Hisashi; Tanaka, Hiroaki; Fuku, Noriyuki

    2018-01-18

    Genetic polymorphisms and sex differences are suggested to affect muscle fiber composition; however, no study has investigated the effects of genetic polymorphisms on muscle fiber composition with respect to sex differences. Therefore, the present study examined the effects of genetic polymorphisms on muscle fiber composition with respect to sex differences in Japanese population. The present study included 211 healthy Japanese individuals (102 men and 109 women). Muscle biopsies were obtained from the vastus lateralis to determine the proportion of myosin heavy chain isoforms (MHC-I, MHC-IIa, and MHC-IIx). Moreover, we analysed polymorphisms in ACTN3 (rs1815739), ACE (rs4341), HIF1A (rs11549465), VEGFR2 (rs1870377), and AGTR2 (rs11091046) by TaqMan SNP genotyping assays. The proportion of MHC-I was 9.8% lower in men than in women, whereas the proportion of MHC-IIa and MHC-IIx was higher in men than in women (5.0% and 4.6%, respectively). Men with ACTN3 RR+RX genotype had 4.8% higher proportion of MHC-IIx than those with ACTN3 XX genotype. Moreover, men with ACE ID+DD genotype had 4.7% higher proportion of MHC-I than those with ACE II genotype. Furthermore, combined genotype of ACTN3 R577X and ACE I/D was significantly correlated with proportion of MHC-I (r = -0.23) and MHC-IIx (r = 0.27) in men. In contrast, no significant correlation was observed between the examined polymorphisms and muscle fiber composition in women. These results suggest that the ACTN3 R577X and ACE I/D polymorphisms independently affect the proportion of human skeletal muscle fibers MHC-I and MHC-IIx in men but not in women.

  13. Dynamic Characters of Stiffened Composite Conoidal Shell Roofs with Cutouts: Design Aids and Selection Guidelines

    OpenAIRE

    Sahoo, Sarmila

    2013-01-01

    Dynamic characteristics of stiffened composite conoidal shells with cutout are analyzed in terms of the natural frequency and mode shapes. A finite element code is developed for the purpose by combining an eight-noded curved shell element with a three-noded curved beam element. The code is validated by solving benchmark problems available in the literature and comparing the results. The size of the cutouts and their positions with respect to the shell centre are varied for different edge cons...

  14. New nutritional composition data on selected traditional foods consumed in Black Sea Area countries.

    Science.gov (United States)

    Costa, Helena S; Albuquerque, Tânia G; Sanches-Silva, Ana; Vasilopoulou, Effie; Trichopoulou, Antonia; D'Antuono, L Filippo; Alexieva, Iordanka; Boyko, Nadiya; Costea, Carmen; Fedosova, Katerina; Hayran, Osman; Karpenko, Dmitry; Kilasonia, Zaza; Finglas, Paul

    2013-11-01

    Traditional foods are an important part of the culture, history, identity and heritage of a region or country and are key elements in dietary patterns. In most countries there is limited information on the nutritional composition of such foods and therefore there is a need to investigate, register and promote traditional foods. One of the aims within the 'Sustainable exploitation of bioactive components from the Black Sea Area traditional foods' (BaSeFood) project is to generate for the first time new data on the nutritional composition of traditional foods from six Black Sea Area countries to promote their sustainable development and exploitation. Thirty-three traditional foods were analysed in an accredited laboratory to determine their nutritional composition, and the data were fully documented. The nutrient content varied widely because of the nature and variety of the analysed foods. The energy content ranged between 4 kcal per 100 g for kvass southern and 900 kcal per 100 g for mustard oil, with the exception of the analysed teas, which did not contribute to energy intake. The use of a common methodology for the study of traditional foods will enable countries to further investigate these foods. Moreover, a new nutritional knowledge base of traditional foods from Black Sea Area countries will contribute to promote local biodiversity and sustainable diets by maintaining healthy dietary patterns within local cultures. © 2013 Society of Chemical Industry.

  15. Humic substances elemental composition of selected taiga and tundra soils from Russian European North-East

    Directory of Open Access Journals (Sweden)

    Lodygin Evgeny

    2017-06-01

    Full Text Available Soils of Russian European North were investigated in terms of stability and quality of organic matter as well as in terms of soils organic matter elemental composi­tion. Therefore, soil humic acids (HAs, extracted from soils of different natural zones of Russian North-East were studied to characterize the degree of soil organic matter stabilization along a zonal gradient. HAs were extracted from soil of different zonal environments of the Komi Republic: south, middle and north taiga as well as south tundra. Data on elemental composition of humic acids and fulvic acids (FAs extracted from different soil types were obtained to assess humus formation mechanisms in the soils of taiga and tundra of the European North-East of Russia. The specificity of HAs elemental composition are discussed in relation to environmental conditions. The higher moisture degree of taiga soils results in the higher H/C ratio in humic substances. This reflects the reduced microbiologic activity in Albeluvisols sods and subsequent conser­vation of carbohydrate and amino acid fragments in HAs. HAs of tundra soils, shows the H/C values decreasing within the depth of the soils, which reflects increasing of aromatic compounds in HA structure of mineral soil horizons. FAs were more oxidized and contains less carbon while compared with the HAs. Humic acids, extracted from soil of different polar and boreal environments differ in terms of elemental composition winch reflects the climatic and hydrological regimes of humification.

  16. Vein grafting in fingertip replantations.

    Science.gov (United States)

    Yan, Hede; Jackson, William D; Songcharoen, Somjade; Akdemir, Ovunc; Li, Zhijie; Chen, Xinglong; Jiang, Liangfu; Gao, Weiyang

    2009-01-01

    In this retrospective study, the survival rates of fingertip replantation with and without vein grafting were evaluated along with their postoperative functional and cosmetic results. One hundred twenty-one-fingertip amputations were performed in 103 patients between September 2002 and July 2007. Thirty-four amputated fingertips were replanted without vein grafting, while 87 amputated fingertips were replanted with vein grafting for arterial and/or venous repairs. The overall survival rates of the replantations with and without vein grafting were 90% (78/87) and 85% (29/34), respectively. The survival rates were 88% (36/41) with venous repair, 93% (25/27) with arterial repair, and 89% (17/19) with both. Nineteen patients without vein grafting and 48 patients with vein grafting had a follow-up period of more than one year. Good cosmetic and functional outcomes were observed in both groups of patients. The results show that vein grafting is a reliable technique in fingertip replantations, showing no significant difference (P > 0.05) in survival between those with and without vein grafting. Furthermore, no significant difference (P > 0.05) in survival was found between cases with vein grafts for arterial and/or venous repairs. In fingertip replantations with vein grafting, favorable functional and esthetic results can be achieved without sacrificing replantation survival. (c) 2009 Wiley-Liss, Inc.

  17. Microstructure, mechanical analysis and optimal selection of 7075 aluminum alloy based composite reinforced with alumina nanoparticles

    International Nuclear Information System (INIS)

    Ezatpour, H.R.; Torabi Parizi, M.; Sajjadi, S.A.; Ebrahimi, G.R.; Chaichi, A.

    2016-01-01

    Aluminum metal-matrix nanocomposites (AMMNCs) fabricated by conventional stir-casting process usually show high porosity and poor distribution of nanoparticles within the matrix. In the current study, for the improvement of nanoparticles distribution in the aluminum matrix and enhancement of the mechanical properties, a mixture of Al/nano-Al 2 O 3 powders were injected by pure argon gas into the molten 7075 aluminum alloy and this mixture was extruded at high temperature. Mechanical behavior of the final product was investigated by tensile and compression tests, hardness measurements, Scanning Electron Microscopy (SEM), High Resolution Transmission Electron Microscopy (HRTEM) and Optical Microscopy. This nanocomposite exhibited some superior properties such as a fine grain microstructure and a reasonable uniform distribution of nanoparticles in the matrix. Mechanical experiments results confirmed that the addition of Al 2 O 3 nanoparticles and the extrusion process effectively improved ultimate tensile strength, compression strength and hardness. In next step, we used a Preference Selection Index (PSI) materials selection method to select best combination of strength and workability of Al7075−Al 2 O 3 nanocomposites. By this method, extruded Al7075/0.4 and 0.8 wt % Al 2 O 3 has best combination of strength and workability. - Highlights: • Injection Al/Al 2 O 3 powder is benefit way for improving nanoparticles distribution. • Nanocomposites present superior mechanical properties. • Extrusion process improved significantly mechanical properties of nanocomposites. • Preference Selection Index is a simple and benefit method in material selection.

  18. Selection of microbial populations degrading recalcitrant hydrocarbons of gasoline by monitoring of culture-headspace composition.

    Science.gov (United States)

    Solano-Serena, F; Marchal, R; Lebeault, J M; Vandecasteele, J P

    2000-01-01

    A methodology was devised and was found useful for the selection of populations degrading recalcitrant hydrocarbons. The work was part of a programme aiming at developing knowledge of the intrinsic capacities of autochtonous microflorae of the environment for gasoline biodegradation. The methodology involved monitoring the progress of degradation in enrichment liquid cultures on the selected hydrocarbon by gas chromatographic analysis of CO2 production and O2 consumption. Populations degrading in particular o-xylene, 1,2,4-trimethylbenzene, cyclohexane were obtained. Concerning 2,2,4-trimethylpentane (isooctane), one microflora (and a pure strain derived from it) growing on this hydrocarbon were obtained from gasoline-polluted water.

  19. Development of electron beam grafted co-polymer membranes for recovery of uranium from seawater: process parameter standardization

    International Nuclear Information System (INIS)

    Bhardwaj, Y.K.; Virendra Kumar; Sarma, K.S.S.; Khader, S.A.; Sabharwal, S.

    2006-03-01

    Polymer matrices have been suggested for effective trapping of uranium from seawater as the trapped uranium can be easily eluted and the polymer matrix can be reused for further trapping of uranium for several cycles. Such polymer matrices have been synthesized by incorporating specific groups into some polymer backbones, which brings about changes in the physicochemical properties of parent polymer backbone and makes it suitable for uptake of uranium. Graft co-polymerization is a suitable means of incorporating desirable groups into parent polymer matrix without drastically affecting the basic properties of the substrate. Radiation grafting has proven to be an easy, reproducible and versatile technique for grafting in comparison to chemical grafting. Development of radiation-grafted copolymers for the purpose of uranium recovery from seawater has been in progress at BARC during last few years. This report describes the work carried out on radiation grafting of acrylonitrile onto thermally bonded non-woven porous polypropylene fiber sheets using electron beam irradiation by post-irradiation grafting technique. The effect of various experimental variables viz. substrate material, form of substrate material, radiation source, grafting technique, grafting dose, dose rate, temperature, grafting solution composition etc. on grafting have been reported. Grafting extent of ∼125% using technical grade chemical were achieved. The grafted nitrile groups were subsequently converted to amidoxime group by chemical treatment. (author)

  20. Ultra-selective defect-free interfacially polymerized molecular sieve thin-film composite membranes for H2 purification

    KAUST Repository

    Ali, Zain

    2017-10-10

    Purification is a major bottleneck towards generating low-cost commercial hydrogen. In this work, inexpensive high-performance H2 separating membranes were fabricated by modifying the commercially successful interfacial polymerization production method for reverse osmosis membranes. Defect-free thin-film composite membranes were formed demonstrating unprecedented mixed-gas H2/CO2 selectivity of ≈ 50 at 140 °C with H2 permeance of 350 GPU, surpassing the permeance/selectivity upper bound of all known polymer membranes by a wide margin. The combination of exceptional separation performance and low manufacturing cost makes them excellent candidates for cost-effective hydrogen purification from steam cracking and similar processes.

  1. Using skeletonised grafts for coronary artery bypass grafting.

    Science.gov (United States)

    Bawany, Faizan Imran; Khan, Muhammad Shahzeb; Khan, Asadullah; Kazi, Abdul Nafey; Naeem, Muhammed

    2014-05-01

    Coronary artery bypass graft surgery relieves angina symptoms and reduces mortality among ischaemic heart disease patients. It remains the gold standard for the treatment of multi-vessel and left main coronary artery disease. It is a well-known fact that internal mammary artery conduits have excellent and long-lasting patency when used for coronary artery bypass grafting. Its supremacy is largely because it prevents atherosclerosis. The old-style internal mammary artery bypass grafting, classically known as pedicle grafting, includes a circular rim of tissue around the graft. Bilateral pedicled internal mammary arteries, especially among diabetic patients, have been reported to cause complications in the sternum like sternal osteomyelitis. In many studies it has been reported that dissection of pedicled internal mammary artery can lead to sternal devascularisation which can lead to higher incidence of infections. Considering the higher incidence of deep sternal infections in patients with double pedicled arterial grafts, dissection of internal mammary artery in skeletonised manner was proposed. In this review, we outline the advantages of skeletonised grafting with respect to incidence of sternal infection, patency rates, blood flow, post-coronary artery bypass graft pain and the length of the graft.

  2. A classification of clinical fat grafting: different problems, different solutions.

    Science.gov (United States)

    Del Vecchio, Daniel; Rohrich, Rod J

    2012-09-01

    Fat grafting has reemerged from a highly variable procedure to a technique with vast reconstructive and cosmetic potential. Largely because of a more disciplined and scientific approach to fat grafting as a transplantation event, early adopters of fat transplantation have begun to approach fat grafting as a process, using sound surgical transplantation principles: recipient preparation, controlled donor harvest, time-efficient transplantation, and proper postoperative care. Despite these principles, different fat grafting techniques yield impressive clinical outcomes. The essential variables of four types of fat grafting cases were identified and compared: harvesting, methods of cell processing, methods of transplantation, and management of the recipient site. Each case differed for most of the variables analyzed. The two clinical drivers that most impacted these differences were the volume demands of the recipient site and whether the recipient site was healthy tissue or pathologic tissue. After these two drivers, a matrix classification of small-volume versus large-volume and regenerative versus nonregenerative cases yields four distinct categories. Not all fat grafting is the same. Fat grafting, once thought to be a simple technique with variable results, is a much more complex procedure with at least four definable subtypes. By defining the essential differences in the recipient site, the key driver in fat transplantation, the proper selection of technique can be best chosen. In fat transplantation, different problems require different solutions.

  3. Contemporary Review of Grafting Techniques for the Surgical Treatment of Peyronie's Disease.

    Science.gov (United States)

    Hatzichristodoulou, Georgios; Osmonov, Daniar; Kübler, Hubert; Hellstrom, Wayne J G; Yafi, Faysal A

    2017-10-01

    Peyronie's disease (PD) is a benign fibrotic disorder of the tunica albuginea of the penis, which can cause penile pain, curvature, shortening, erectile dysfunction, and psychological distress. Surgery is indicated when penile curvature prevents satisfactory sexual intercourse. Plaque incision or excision with grafting has been suggested as an option in patients with a penile curvature greater than 60°, a shortened penis, and/or an hourglass or complex deformity. To provide an overview of recent studies reporting outcomes of grafting techniques and to report advances in the development of new grafting materials for PD surgery. A literature review was performed through PubMed from 2011 through 2016 regarding grafting techniques for PD. Key words used for the search were grafting techniques, grafts, graft materials, Peyronie's disease, surgical outcomes, and surgical therapy. To report on novel and promising graft materials for PD and to discuss surgical techniques, outcomes, and limitations. Discussed outcomes include postoperative penile straightening, shortening, erectile function, glans sensation, and patient satisfaction. Various surgical techniques and grafting materials can be used for the coverage of the tunica albuginea defect after partial plaque excision or incision. Autologous and non-autologous grafts have been used in this setting. A major advantage of the available "off-the-shelf" grafts is that they do not require donor site harvesting, thus decreasing morbidity and operative time. Tissue-engineered grafts represent the future, but more research is needed to further improve surgical handling and postoperative outcomes. Patients opting for grafting techniques should have sufficient erectile rigidity preoperatively. Surgeon experience, careful patient selection, patient preference, and type of penile deformity affect the choice of graft and surgical approach used. Hatzichristodoulou G, Osmonov D, Kübler H, et al. Contemporary Review of Grafting

  4. Synthesis of hyperbranched copolyimides and their application as selective layers in composite membranes

    Czech Academy of Sciences Publication Activity Database

    Peter, Jakub; Kosmala, Barbara; Bleha, Miroslav

    2009-01-01

    Roč. 245, 1-3 (2009), s. 516-526 ISSN 0011-9164. [Engineering with Membranes 2008; Membrane Processes: Development, Monitoring and Modelling – From the Nano to the Macro Scale – EWM 2008. Vale do Lobo, Algarve, 25.05.2008-28.05.2008] R&D Projects: GA MPO 2A-1TP1/116 Institutional research plan: CEZ:AV0Z40500505 Keywords : hyperbranched polyimide * composite membrane * gas separation * soluble polyimide Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.034, year: 2009

  5. Hanford Site Composite Analysis Technical Approach Description: Radionuclide Inventory and Waste Site Selection Process.

    Energy Technology Data Exchange (ETDEWEB)

    Nichols, Will E.; Mehta, Sunil

    2017-09-13

    The updated Hanford Site Composite Analysis will provide an all-pathways dose projection to a hypothetical future member of the public from all planned low-level radioactive waste disposal facilities and potential contributions from all other projected end-state sources of radioactive material left at Hanford following site closure. Its primary purpose is to support the decision-making process of the U.S. Department of Energy (DOE) under DOE O 435.1-1, Radioactive Waste Management (DOE, 2001), related to managing low-level waste disposal facilities at the Hanford Site.

  6. Selective confinement of vibrations in composite systems with alternate quasi-regular sequences

    Energy Technology Data Exchange (ETDEWEB)

    Montalban, A. [Departamento de Ciencia y Tecnologia de Materiales, Division de Optica, Universidad Miguel Hernandez, 03202 Elche (Spain); Velasco, V.R. [Instituto de Ciencia de Materiales de Madrid, CSIC, Sor Juana Ines de la Cruz 3, 28049 Madrid (Spain)]. E-mail: vrvr@icmm.csic.es; Tutor, J. [Departamento de Fisica Aplicada, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain); Fernandez-Velicia, F.J. [Departamento de Fisica de los Materiales, Facultad de Ciencias, Universidad Nacional de Educacion a Distancia, Senda del Rey 9, 28080 Madrid (Spain)

    2007-01-01

    We have studied the atom displacements and the vibrational frequencies of 1D systems formed by combinations of Fibonacci, Thue-Morse and Rudin-Shapiro quasi-regular stacks and their alternate ones. The materials are described by nearest-neighbor force constants and the corresponding atom masses, particularized to the Al, Ag systems. These structures exhibit differences in the frequency spectrum as compared to the original simple quasi-regular generations but the most important feature is the presence of separate confinement of the atom displacements in one of the sequences forming the total composite structure for different frequency ranges.

  7. Selective confinement of vibrations in composite systems with alternate quasi-regular sequences

    International Nuclear Information System (INIS)

    Montalban, A.; Velasco, V.R.; Tutor, J.; Fernandez-Velicia, F.J.

    2007-01-01

    We have studied the atom displacements and the vibrational frequencies of 1D systems formed by combinations of Fibonacci, Thue-Morse and Rudin-Shapiro quasi-regular stacks and their alternate ones. The materials are described by nearest-neighbor force constants and the corresponding atom masses, particularized to the Al, Ag systems. These structures exhibit differences in the frequency spectrum as compared to the original simple quasi-regular generations but the most important feature is the presence of separate confinement of the atom displacements in one of the sequences forming the total composite structure for different frequency ranges

  8. Polyacrylonitrile (PAN)/crown ether composite nanofibers for the selective adsorption of cations

    NARCIS (Netherlands)

    Tas, Sinem; Kaynan, Ozge; Ozden-Yenigun, Elif; Nijmeijer, Dorothea C.

    2016-01-01

    In this study, we prepared electrospun polyacrylonitrile (PAN) nanofibers functionalized with dibenzo-18-crown-6 (DB18C6) crown ether and showed the potential of these fibers for the selective recovery of K+ from other both mono- and divalent ions in aqueous solutions. Nanofibers were characterized

  9. The Impact of Legalized Abortion on High School Graduation through Selection and Composition

    Science.gov (United States)

    Whitaker, Stephan

    2011-01-01

    This analysis examines whether the legalization of abortion changed high school graduation rates among the children selected into birth. Unless women in all socio-economic circumstances sought abortions to the same extent, increased use of abortion must have changed the distribution of child development inputs. I find that higher abortion ratios…

  10. RESULTS OF THE SELECTION OF BREEDING SAMPLES OF CARROT BASED ON BIOCHEMICAL COMPOSITION

    Directory of Open Access Journals (Sweden)

    V. K. Cherkasova

    2014-01-01

    Full Text Available 12 samples of carrot were analyzed for biochemical components in roots. 5 genotypes with high content of vitamin C, β-carotene, and total sugar were selected as genetic sources of high biochemical components.

  11. Multidimensional CAT Item Selection Methods for Domain Scores and Composite Scores: Theory and Applications

    Science.gov (United States)

    Yao, Lihua

    2012-01-01

    Multidimensional computer adaptive testing (MCAT) can provide higher precision and reliability or reduce test length when compared with unidimensional CAT or with the paper-and-pencil test. This study compared five item selection procedures in the MCAT framework for both domain scores and overall scores through simulation by varying the structure…

  12. Microstructure, mechanical analysis and optimal selection of 7075 aluminum alloy based composite reinforced with alumina nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Ezatpour, H.R., E-mail: H.R.Ezatpour@gmail.com [Faculty of Engineering, Sabzevar University of New Technology, Sabzevar (Iran, Islamic Republic of); Torabi Parizi, M. [Dept. of Materials Science and Metallurgical Engineering, Engineering Faculty, Semnan University of Semnan, Semnan (Iran, Islamic Republic of); Sajjadi, S.A. [Dept. of Materials Science and Metallurgical Engineering, Engineering Faculty, Ferdowsi University of Mashhad, Mashhad (Iran, Islamic Republic of); Ebrahimi, G.R. [Department of Materials and Polymer Engineering, Hakim Sabzevari University, Sabzevar (Iran, Islamic Republic of); Chaichi, A. [Dept. of Materials Science and Engineering, Sharif University of Technology, Tehran (Iran, Islamic Republic of)

    2016-08-01

    Aluminum metal-matrix nanocomposites (AMMNCs) fabricated by conventional stir-casting process usually show high porosity and poor distribution of nanoparticles within the matrix. In the current study, for the improvement of nanoparticles distribution in the aluminum matrix and enhancement of the mechanical properties, a mixture of Al/nano-Al{sub 2}O{sub 3} powders were injected by pure argon gas into the molten 7075 aluminum alloy and this mixture was extruded at high temperature. Mechanical behavior of the final product was investigated by tensile and compression tests, hardness measurements, Scanning Electron Microscopy (SEM), High Resolution Transmission Electron Microscopy (HRTEM) and Optical Microscopy. This nanocomposite exhibited some superior properties such as a fine grain microstructure and a reasonable uniform distribution of nanoparticles in the matrix. Mechanical experiments results confirmed that the addition of Al{sub 2}O{sub 3} nanoparticles and the extrusion process effectively improved ultimate tensile strength, compression strength and hardness. In next step, we used a Preference Selection Index (PSI) materials selection method to select best combination of strength and workability of Al7075−Al{sub 2}O{sub 3} nanocomposites. By this method, extruded Al7075/0.4 and 0.8 wt % Al{sub 2}O{sub 3} has best combination of strength and workability. - Highlights: • Injection Al/Al{sub 2}O{sub 3} powder is benefit way for improving nanoparticles distribution. • Nanocomposites present superior mechanical properties. • Extrusion process improved significantly mechanical properties of nanocomposites. • Preference Selection Index is a simple and benefit method in material selection.

  13. Potential influence of selection criteria on the demographic composition of students in an Australian medical school

    Directory of Open Access Journals (Sweden)

    Puddey Ian B

    2011-11-01

    Full Text Available Abstract Background Prior to 1999 students entering our MBBS course were selected on academic performance alone. We have now evaluated the impact on the demographics of subsequent cohorts of our standard entry students (those entering directly from high school of the addition to the selection process of an aptitude test (UMAT, a highly structured interview and a rural incentive program. Methods Students entering from 1985 to 1998, selected on academic performance alone (N = 1402, were compared to those from 1999 to 2011, selected on the basis of a combination of academic performance, interview score, and UMAT score together with the progressive introduction of a rural special entry pathway (N = 1437. Results Males decreased from 57% to 45% of the cohort, students of NE or SE Asian origin decreased from 30% to 13%, students born in Oceania increased from 52% to 69%, students of rural origin from 5% to 21% and those from independent high schools from 56% to 66%. The proportion of students from high schools with relative socio-educational disadvantage remained unchanged at approximately 10%. The changes reflect in part increasing numbers of female and independent high school applicants and the increasing rural quota. However, they were also associated with higher interview scores in females vs males and lower interview scores in those of NE and SE Asian origin compared to those born in Oceania or the UK. Total UMAT scores were unrelated to gender or region of origin. Conclusions The revised selection processes had no impact on student representation from schools with relative socio-educational disadvantage. However, the introduction of special entry quotas for students of rural origin and a structured interview, but not an aptitude test, were associated with a change in gender balance and ethnicity of students in an Australian undergraduate MBBS course.

  14. Physicochemical properties and composition of lipid fraction of selected edible nuts

    International Nuclear Information System (INIS)

    Derewiaka, D.; Szwed, E.; Wolosiak, R.

    2014-01-01

    The study presents the characteristics of oil fraction of 8 types of edible nuts available on the Polish market. All tested nuts were characterized with high content of dry matter. Fatty acid and sterol composition was analyzed by GC-MS. Squalene and tocopherol profiles were examined by HPLC with diode array (DAD) and fluorescence detectors (FLDs). The highest level of fat was found in macadamia (75.4 g/100 g) and the lowest in cashew nuts (46.9 g/100 g). Fatty analysis showed that nuts were rich in unsaturated fatty acids. Monounsaturated fatty acids were predominant in most cases, with the exception of Brazilian nuts, walnuts and pine nuts which were richer in polyunsaturated fatty acids. Sitosterol was the main sterol of nuts, and its content ranged from 96.9 mg/100 g of oil (in macadamia) to 474.8 mg/100 g of oil (in pistachio). Tocopherol homologue was predominant among its fraction with the largest content determined in pistachio (8.3 mg/100 g of oil) and walnuts (8.6 mg/100 g of oil). The presence of squalene was confirmed in seven types of nuts, and the richest source of it were Brazilian nuts (145.8 mg/100 g of oil). The study proofs the variation of nut oil composition, especially phytosterol and tocopherol content and can be used for better characterization of nuts derived from different geographic areas or cultivars. (author)

  15. Chemical composition of selected seaweeds from the Indian Ocean, KwaZulu-Natal coast, South Africa.

    Science.gov (United States)

    Magura, Judie; Moodley, Roshila; Jonnalagadda, Sreekantha B

    2016-08-02

    The chemical composition of three edible seaweeds (Codium capitatum, Hypnea spicifera and Sargassum elegans) and two inedible seaweeds (Halimeda cuneata and Spyridia hypnoides) from the Indian Ocean along the KwaZulu-Natal East Coast, South Africa were investigated as a function of seasonal variation. The proximate compositions of the edible seaweeds were determined. In edible seaweeds, the moisture level ranged from 85.4 to 89.5%, protein from 6.1 to 11.8%, lipids from 7.5 to 13.1% and carbohydrates from 37.8 to 71.9%. Elemental concentrations in the five studied seaweeds varied significantly with season (P seaweeds which was dissimilar to that in inedible seaweeds. This study suggests that edible macro alga, C. capitatum and H. spicifera, could be potential sources of most essential nutrients and may contribute positively to the diet without posing the risk of adverse health effects due to low concentrations of toxic elements. However, due to high levels of As in S. elegans, its consumption should be moderated to reduce dietary exposure to this toxic element.

  16. Lignocellulosic fiber reinforced rubber composites

    CSIR Research Space (South Africa)

    Jacob John, Maya

    2009-04-01

    Full Text Available polymerization reaction using Zieglar-Natta- hetergenous catalyst. The important components of NR are given in Table I. Lignocellulosic Fiber Reinforced Rubber Composites -253- Figure 1. Structure of natural rubber NR has a very uniform.... Grafting a second polymer onto the NR backbone Grafting is mostly carried out using vinyl monomers like methyl methacrylate (MMA) and styrene. The commercial available grafted copolymer of NR with poly (methyl methacrylate) (PMMA) is Heveaplus MG...

  17. Micrografts: the "super" expansion graft.

    Science.gov (United States)

    Mardovin, W; Miller, S F; Eppinger, M; Finley, R K

    1992-01-01

    A novel technique for producing micronized skin grafts that was introduced in a paper presented at the 1990 ABA meeting was evaluated to quantify maximum expansion. Twenty Sprague-Dawley rats were divided into two groups representing 10:1 and 25:1 expanded micrograft ratios, respectively. Grafted sites in both groups were shown to heal better than those of the control group, and both grafted groups showed comparable healing at day 10.

  18. Permeability and Selectivity of PPO/Graphene Composites as Mixed Matrix Membranes for CO2 Capture and Gas Separation

    Directory of Open Access Journals (Sweden)

    Riccardo Rea

    2018-01-01

    Full Text Available We fabricated novel composite (mixed matrix membranes based on a permeable glassy polymer, Poly(2,6-dimethyl-1,4-phenylene oxide (PPO, and variable loadings of few-layer graphene, to test their potential in gas separation and CO2 capture applications. The permeability, selectivity and diffusivity of different gases as a function of graphene loading, from 0.3 to 15 wt %, was measured at 35 and 65 °C. Samples with small loadings of graphene show a higher permeability and He/CO2 selectivity than pure PPO, due to a favorable effect of the nanofillers on the polymer morphology. Higher amounts of graphene lower the permeability of the polymer, due to the prevailing effect of increased tortuosity of the gas molecules in the membrane. Graphene also allows dramatically reducing the increase of permeability with temperature, acting as a “stabilizer” for the polymer matrix. Such effect reduces the temperature-induced loss of size-selectivity for He/N2 and CO2/N2, and enhances the temperature-induced increase of selectivity for He/CO2. The study confirms that, as observed in the case of other graphene-based mixed matrix glassy membranes, the optimal concentration of graphene in the polymer is below 1 wt %. Below such threshold, the morphology of the nanoscopic filler added in solution affects positively the glassy chains packing, enhancing permeability and selectivity, and improving the selectivity of the membrane at increasing temperatures. These results suggest that small additions of graphene to polymers can enhance their permselectivity and stabilize their properties.

  19. Experimental and Thermodynamic Study of Selected in-Situ Composites from the Fe-Cr-Ni-Mo-C System

    Directory of Open Access Journals (Sweden)

    Wieczerzak K.

    2016-06-01

    Full Text Available The aim of the study was to synthesize and characterize the selected in-situ composites from the Fe-Cr-Ni-Mo-C system, additionally strengthened by intermetallic compounds. The project of the alloys was supported by thermodynamic simulations using Calculation of Phase Diagram approach via Thermo-Calc. Selected alloys were synthesized in an arc furnace in a high purity argon atmosphere using a suction casting unit. The studies involved a range of experimental techniques to characterize the alloys in the as-cast state, including optical emission spectrometry, light microscopy, scanning electron microscopy, electron microprobe analysis, X-ray diffraction and microhardness tests. These experimental studies were compared with the Thermo-Calc data and high resolution dilatometry. The results of investigations presented in this paper showed that there is a possibility to introduce intermetallic compounds, such as χ and σ, through modification of the chemical composition of the alloy with respect to Nieq and Creq. It was found that the place of intermetallic compounds precipitation strongly depends on matrix nature. Results presented in this paper may be successfully used to build a systematic knowledge about the group of alloys with a high volume fraction of complex carbides, and high physicochemical properties, additionally strengthened by intermetallic compounds.

  20. Comparison of Fatty Acid Composition in Selected Dietary Supplements Containing Conjugated Linoleic Acid.

    Science.gov (United States)

    Derewiaka, Dorota; Nestorowicz, Klara; Wołosiak, Rafał

    2017-07-04

    The market of pharmaceutical products is offering a wide range of supplements. Most of the consumers believe that these products will improve their state of health, but are they getting what they want and what they are paying for? The aim of the study was to evaluate the quality of selected dietary supplements containing conjugated linoleic acid (CLA). All supplements were available in the Warsaw markets and bought from pharmacies. Assessment of the quality of food supplements was achieved by analysis of fatty acid using gas chromatography coupled with a mass spectrometer. On the basis of the investigations carried out, it was found that content of CLA in selected dietary supplements ranged between 282 and 528 mg by weight of a single capsule. The content of bioactive ingredients found in three of the four product supplements assessed was lower than was claimed by the manufacturer.

  1. Chemical Composition and Labeling of Substances Marketed as Selective Androgen Receptor Modulators and Sold via the Internet.

    Science.gov (United States)

    Van Wagoner, Ryan M; Eichner, Amy; Bhasin, Shalender; Deuster, Patricia A; Eichner, Daniel

    2017-11-28

    Recent reports have described the increasing use of nonsteroidal selective androgen receptor modulators, which have not been approved by the US Food and Drug Administration (FDA), to enhance appearance and performance. The composition and purity of such products is not known. To determine the chemical identity and the amounts of ingredients in dietary supplements and products marketed and sold through the internet as selective androgen receptor modulators and compare the analyzed contents with product labels. Web-based searches were performed from February 18, 2016, to March 25, 2016, using the Google search engine on the Chrome and Internet Explorer web browsers to identify suppliers selling selective androgen receptor modulators. The products were purchased and the identities of the compounds and their amounts were determined from April to August 2016 using chain-of-custody and World Anti-Doping Association-approved analytical procedures. Analytical findings were compared against the label information. Products marketed and sold as selective androgen receptor modulators. Chemical identities and the amount of ingredients in each product marketed and sold as selective androgen receptor modulators. Among 44 products marketed and sold as selective androgen receptor modulators, only 23 (52%) contained 1 or more selective androgen receptor modulators (Ostarine, LGD-4033, or Andarine). An additional 17 products (39%) contained another unapproved drug, including the growth hormone secretagogue ibutamoren, the peroxisome proliferator-activated receptor-δ agonist GW501516, and the Rev-ErbA agonist SR9009. Of the 44 tested products, no active compound was detected in 4 (9%) and substances not listed on the label were contained in 11 (25%). In only 18 of the 44 products (41%), the amount of active compound in the product matched that listed on the label. The amount of the compounds listed on the label differed substantially from that found by analysis in 26 of 44 products

  2. SURVIVAL AND VEGETATIVE VIGOR OF Ilex paraguariensis A. St.- Hil. PLANTS GRAFTED DIRECTLY IN THE FIELD

    Directory of Open Access Journals (Sweden)

    Danilo Martin Domingos

    2010-08-01

    Full Text Available The present work aimed to evaluate the survival and the vegetative vigor of adult selected genetic material of Ilex paraguariensis A.St.- Hil. grafted directly in the field. The grafting was accomplished in approximately 3 year-old understocks, and the material collected was close to the base of two selected trees with around 70 years old. The grafting method used was the top cleft, in which 48 plants were grafted with material of each one of the two plus trees. The survival data were obtained at 60 and 90 days after the grafting, and of growth (amount and total length of sprouts at 90 and 120 days after the grafting. It could be concluded that: there was a decrease in the survival of the grafts in function of the number of days after the grafting; the used plus trees presented different behaviors in the survival percentage; the surviving grafts plants demonstrated a good growth vigor. It is presupposed that the low percentile of success (about of 40% is linked to the high physiologic age of the plus trees, besides less favorable environmental conditions when compared with the grafting in the nursery.

  3. Adequacy of palmaris longus and plantaris tendons for tendon grafting.

    Science.gov (United States)

    Jakubietz, Michael G; Jakubietz, Danni F; Gruenert, Joerg G; Zahn, Robert; Meffert, Rainer H; Jakubietz, Rafael G

    2011-04-01

    The reconstruction of tendon defects is challenging. The palmaris longus and plantaris tendon are generally considered best for tendon grafting. Only a few studies have examined whether these tendons, when present, meet criteria for successful grafting. The purpose of this study was to evaluate these tendons in regard to adequacy as tendon grafts. To evaluate adequacy for grafting, the palmaris longus and plantaris tendons were harvested from 92 arms and legs of 46 cadavers. Macroscopic evaluation and measurements concerning presence, length, and diameter of the tendons were obtained. Criteria for adequacy were a minimum length of 15 cm with diameter of 3 mm or, alternatively, 30 cm with a diameter of 1.5 mm. The palmaris longus tendon was present bilaterally in 36 cases and was absent bilaterally in 4 cases. The plantaris tendon was present bilaterally in 38 cases and absent bilaterally in 4 cases. In 29 cadavers, the palmaris longus tendon did not meet the criteria to be used as a tendon graft. Only in 8 cases were the tendons satisfactory for grafting bilaterally. The plantaris tendon met criteria for grafting in 20 cases bilaterally. In 17 cases, the tendons were considered inadequate bilaterally. Despite their presence, the palmaris longus and plantaris tendons are adequate for grafting less often than previously thought. In less than 50%, the tendons, although present, would serve as useful grafts. Our findings underscore the importance of choosing a second donor site before surgery in case the primarily selected tendon is not found to be suitable. Copyright © 2011 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  4. Magnetizable stent-grafts enable endothelial cell capture

    Energy Technology Data Exchange (ETDEWEB)

    Tefft, Brandon J. [Department of Cardiovascular Diseases, Mayo Clinic, Rochester, MN (United States); Uthamaraj, Susheil [Division of Engineering, Mayo Clinic, Rochester, MN (United States); Harburn, J. Jonathan [School of Medicine, Pharmacy and Health, Durham University, Stockton-on-Tees (United Kingdom); Hlinomaz, Ota [Department of Cardioangiology, St. Anne' s University Hospital, Brno (Czech Republic); Lerman, Amir [Department of Cardiovascular Diseases, Mayo Clinic, Rochester, MN (United States); Dragomir-Daescu, Dan [Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN (United States); Sandhu, Gurpreet S., E-mail: sandhu.gurpreet@mayo.edu [Department of Cardiovascular Diseases, Mayo Clinic, Rochester, MN (United States)

    2017-04-01

    Emerging nanotechnologies have enabled the use of magnetic forces to guide the movement of magnetically-labeled cells, drugs, and other therapeutic agents. Endothelial cells labeled with superparamagnetic iron oxide nanoparticles (SPION) have previously been captured on the surface of magnetizable 2205 duplex stainless steel stents in a porcine coronary implantation model. Recently, we have coated these stents with electrospun polyurethane nanofibers to fabricate prototype stent-grafts. Facilitated endothelialization may help improve the healing of arteries treated with stent-grafts, reduce the risk of thrombosis and restenosis, and enable small-caliber applications. When placed in a SPION-labeled endothelial cell suspension in the presence of an external magnetic field, magnetized stent-grafts successfully captured cells to the surface regions adjacent to the stent struts. Implantation within the coronary circulation of pigs (n=13) followed immediately by SPION-labeled autologous endothelial cell delivery resulted in widely patent devices with a thin, uniform neointima and no signs of thrombosis or inflammation at 7 days. Furthermore, the magnetized stent-grafts successfully captured and retained SPION-labeled endothelial cells to select regions adjacent to stent struts and between stent struts, whereas the non-magnetized control stent-grafts did not. Early results with these prototype devices are encouraging and further refinements will be necessary in order to achieve more uniform cell capture and complete endothelialization. Once optimized, this approach may lead to more rapid and complete healing of vascular stent-grafts with a concomitant improvement in long-term device performance. - Highlights: • Magnetic stent-grafts were made from 2205 steel stents and polyurethane nanofibers. • Stent-grafts remained patent and formed a thin and uniform neointima when implanted. • Stent-grafts captured endothelial cells labeled with magnetic nanoparticles.

  5. Examination of coagulant additives on qualitative composition of selected thermal waters

    Science.gov (United States)

    Łukasiewicz, Ewelina; Rząsa, Mariusz

    2017-10-01

    On the territory of Poland occur rich deposits of thermal waters. Although the utilisation of these waters is continuously extending, Poland is not exploiting their full geothermal potential due to high investment costs. Thermal waters industry in Poland to date indicates operations within mainly balneology as well as recreation objectives. Higher temperature values of these waters foster a washout in the surrounding rocks resulting in a high concentration of diluted substances which must be often removed. The following study investigates thermal waters from three intakes for which coagulation processes were conducted. Research clearly shows that coagulant additives not impact on the qualitative composition of thermal water, what is very important according to medicinal properties of water. The study results may be further applied as a valuable piece of information for further exploitation in balneology or within the heating sector and other installations.

  6. The determination of residual perchlorate after the controlled ignition of selected fireworks compositions

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, K.; Ridley, W.; Guilbeault, R.; Duff, B.

    2008-04-15

    This study investigated perchlorate releases into the atmosphere caused by fireworks displays. Five perchlorate-based compositions were ignited in a sealed stainless steel vessel. The interior of the vessel and the exhaust filters were then washed with hot de-ionized water. Ion chromatography was then used to analyzed the water solutions. Amounts of perchlorate ion measured in the solution were then used to calculate the percentage of residual perchlorate based on the original mass of perchlorate contained within the samples. The study showed that 99.98 to 99.999 per cent of the initial mass of perchlorate in the samples was consumed during ignition. It was concluded that the incomplete combustion of fireworks caused by defective article construction will cause higher amounts of perchlorate releases into the environment. Stricter quality controls are needed to reduce the environmental impacts of fireworks. 14 refs., 4 tabs., 3 figs.

  7. Isotopic composition and radiological properties of uranium in selected fuel cycles

    International Nuclear Information System (INIS)

    Fleischman, R.M.; Liikala, R.C.

    1975-04-01

    Three major topic areas are discussed: First, the properties of the uranium isotopes are defined relative to their respective roles in the nuclear fuel cycle. Secondly, the most predominant fuel cycles expected in the U. S. are described. These are the Light Water Reactor (LWR), High Temperature Gas Cooled Reactor (HTGR), and Liquid Metal Fast Breeder Reactor (LMFBR) fuel cycles. The isotopic compositions of uranium and plutonium fuels expected for these fuel cycles are given in some detail. Finally the various waste streams from these fuel cycles are discussed in terms of their relative toxicity. Emphasis is given to the high level waste streams from reprocessing of spent fuel. Wastes from the various fuel cycles are compared based on projected growth patterns for nuclear power and its various components. (U.S.)

  8. Mesoporous TiO2 Micro-Nanometer Composite Structure: Synthesis, Optoelectric Properties, and Photocatalytic Selectivity

    Directory of Open Access Journals (Sweden)

    Kun Liu

    2012-01-01

    Full Text Available Mesoporous anatase TiO2 micro-nanometer composite structure was synthesized by solvothermal method at 180°C, followed by calcination at 400°C for 2 h. The as-prepared TiO2 was characterized by X-ray diffraction (XRD, scanning electron microscope (SEM, transmission electron microscope (TEM, and Fourier transform infrared spectrum (FT-IR. The specific surface area and pore size distribution were obtained from N2 adsorption-desorption isotherm, and the optoelectric property of the mesoporous TiO2 was studied by UV-Vis absorption spectrum and surface photovoltage spectra (SPS. The photocatalytic activity was evaluated by photodegradation of sole rhodamine B (RhB and sole phenol aqueous solutions under simulated sunlight irradiation and compared with that of Degussa P-25 (P25 under the same conditions. The photodegradation preference of this mesoporous TiO2 was also investigated for an RhB-phenol mixed solution. The results show that the TiO2 composite structure consists of microspheres (∼0.5–2 μm in diameter and irregular aggregates (several hundred nanometers with rough surfaces and the average primary particle size is 10.2 nm. The photodegradation activities of this mesoporous TiO2 on both RhB and phenol solutions are higher than those of P25. Moreover, this as-prepared TiO2 exhibits photodegradation preference on RhB in the RhB-phenol mixture solution.

  9. Laccase from Aspergillus niger: A novel tool to graft multifunctional materials of interests and their characterization.

    Science.gov (United States)

    Iqbal, Hafiz M N; Kyazze, Godfrey; Tron, Thierry; Keshavarz, Tajalli

    2018-03-01

    In the present study, we propose a green route to prepare poly(3-hydroxybutyrate) [(P(3HB)] grafted ethyl cellulose (EC) based green composites with novel characteristics through laccase-assisted grafting. P(3HB) was used as a side chain whereas, EC as a backbone material under ambient processing conditions. A novel laccase obtained from Aspergillus niger through its heterologous expression in Saccharomyces cerevisiae was used as a green catalyst for grafting purposes without the use of additional initiator and/or cross-linking agents. Subsequently, the resulting P(3HB)- g -EC composites were characterized using a range of analytical and imagining techniques. Fourier transform infrared spectroscopy (FT-IR) spectra showed an increase in the hydrogen-bonding type interactions between the side chains of P(3HB) and backbone material of EC. Evidently, X-ray diffraction (XRD) analysis revealed a decrease in the crystallinity of the P(3HB)- g -EC composites as compared to the pristine individual polymers. A homogeneous P(3HB) distribution was also achieved in case of the graft composite prepared in the presence of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) as a mediator along with laccase as compared to the composite prepared using pure laccase alone. A substantial improvement in the thermal and mechanical characteristics was observed for grafted composites up to the different extent as compared to the pristine counterparts. The hydrophobic/hydrophilic properties of the grafted composites were better than those of the pristine counterparts.

  10. SELECTED PHYSICAL PROPERTIES OF EXTRUDED COMPOSITES TYPE OF POROUS PVC-METAL

    Directory of Open Access Journals (Sweden)

    Aneta Tor-Świątek

    2014-09-01

    Full Text Available The article presents studies of selected physical and mechanical properties of hybrid materials type of polymer-metal. In the frame of this work modification of PVC with the iron and copper powder in amount of 0, 1.5 and 3% and blowing agent in amount of 0, 0.5, 1% was done. Extrudates in a form of pipe were tested to determine density, porosity, maximum tensile stress, stress at break, modulus of elasticity and elongation with break. The samples were also observed in a microscope. The studies have shown significant influence of the added components on the properties tested.

  11. Suction blister grafting - Modifications for easy harvesting and grafting

    Directory of Open Access Journals (Sweden)

    2012-01-01

    Full Text Available Suction blister grafting is a simple modality of treatment of patients with resistant and stable vitiligo. But raising the blisters may be time consuming and transferring to the recipient site may be difficult as the graft is ultrathin. By doing some modifications we can make the technique simpler and easier. We can decrease the blister induction time by intradermal injection of saline, exposure to Wood′s lamp, intrablister injection of saline. By these methods we can decrease the blister induction time from 2-3 hrs to 45-90 minutes. After harvesting the graft, it can be transferred to the recipient area by taking the graft on a sterile glass slide, on the gloved finger, rolling the graft over a sterile syringe and then spreading on the recipient area, or taking on the sterile wrapper of paraffin dressing and then placing over the recipient area.

  12. Radiation grafted polymeric sorbents using 10 MeV electron beam - for recovery of valuable elements from seawater

    International Nuclear Information System (INIS)

    Prasad, T.L.; Goswami, D.; Tewari, P.K.

    2013-01-01

    India with a vast coastline of around 7500 km has a large stake in exploiting the valuable elements locked in seawater. This requires selective recovery of the target metal ions from multicomponent ionic system and the separation process must be able to operate in-situ without altering chemical compositions of seawater. Radiation grafted sorbent have opened up the avenue for achieving tailor made surfaces and thereby selectivity for different heavy metal ions of interest. Surface modifications for incorporation of required functional groups on the polymer back bone have been carried out using Electron Beam (EB) irradiation. Metal Chelate Embedded Polymers (MCEP) are specially synthesized for uranium extraction from seawater using radiation grafting techniques using higher GSM (Grammer per Square Meter) polypropylene substrate materials. The grafting levels observed and their physical and mechanical characteristics are presented in this paper. In-field trials have been carried out by submerging the irradiated and oximated tokens for different durations of up to 16 days at Trombay estuary. Normal tidal movement is used for contacting the submerged tokens with water body

  13. Controlled grafting of cellulose esters using SET-LRP process

    Czech Academy of Sciences Publication Activity Database

    Vlček, Petr; Raus, Vladimír; Janata, Miroslav; Kříž, Jaroslav; Sikora, Antonín

    2011-01-01

    Roč. 49, č. 1 (2011), s. 164-173 ISSN 0887-624X R&D Projects: GA ČR GA106/09/1348 Institutional research plan: CEZ:AV0Z40500505 Keywords : cellulose esters * copolymerization * graft copolymers Subject RIV: JI - Composite Materials Impact factor: 3.919, year: 2011

  14. The Composition Effect of Macroeconomic Factors on Foreign Direct Investment in Selected SAARC Countries

    Directory of Open Access Journals (Sweden)

    Mehwish MALIK

    2014-06-01

    Full Text Available The objective of the study is to investigate the most promising economic variables i.e., foreign direct investment (FDI, exports and financial development on economic growth in selected South Asian Association of Regional Co-corporation (SAARC countries. In addition, this study argued that whether FDI, Exports and financial development fosters or hinder economic growth in SAARC countries, for this purpose, panel data set of selected five SAARC countries namely, Bangladesh, India, Nepal, Pakistan and Srilanka considered for empirical consideration over a period of 1975 to 2011. By using two-stage least square (2SLSL technique, empirical evidence on the effects of FDI, exports and financial development on economic growth is mix in terms of apriori expectations. In case of Bangladesh, exports and broad money supply (M2 is the positive and significant contributor to increase economic growth, whereas, M2 increases India’s GDP. FDI is the only significant contributor to increase Pakistan’s economic growth. In case of Nepal and Srilanka, broad money supply increases economic growth, whereas, due to high dependency on imports, exports could not considerably increases economic growth in those regions.

  15. Chemical composition and technological characteristics of wines from red grape varieties, selected in Bulgaria

    Directory of Open Access Journals (Sweden)

    V. Haygarov

    2017-03-01

    Full Text Available Abstract. Chemical analysis of grapes and technological characterization of wines from red varieties Storgoziya, Kaylashky rubin, Trapezitza, Rubin and Bouquet, created by the method of intraspecific and interspecific hybridization at the Institute of Viticulture and Enology – Pleven, Bulgaria were made. The technological maturity of the grapes as raw material for producing quality red wines was determined. Rubin variety was with the highest sugar content - 3 23.10±0.73 %, titratable acids - 6.18±0.34 g/dm and pH 3.40±0.71. The other varieties were with optimal condition for the production of red wines in terms of sugars and titratable acids. The chemical composition and organoleptic characteristics of the experimental wine samples were established. The ethyl alcohol content in the produced wines was in the range from 12.33±0.23 vol. % (Bouquet to 13.31±0.34 vol. % (Kaylashky rubin. The content of titratable acids was in 3 3 the range of 5.33±0.43 g/dm (Trapezitza up to 6.88±0.21 g/dm (Kaylashky rubin. There were no significant differences in the analyzed indicators and taste evaluation between experimental wines and wine of Vitis vinifera – Pinot noir grape variety used as control sample

  16. Comparative studies on flour proximate compositions and functional properties of selected Pakistani rice varieties

    International Nuclear Information System (INIS)

    Jamal, S.; Qazi, I.M.; Ahmed, I.

    2016-01-01

    The aim of this study was to evaluate the proximate and functional properties of flours obtained from various rice varieties, i.e., Super Basmati Shaheen, Super Basmati Kainat, Super Fine, JP5, Basmati 385, Fakhr-e-Malakand grown in different areas of Pakistan. Moisture content, ash content, crude protein, crude fat, water absorption index, water solubility and swelling power varied significantly (P<0.05) from each other. Moisture content, ash content, crude protein and crude fat of rice flour ranged from 5.46-7.08 percentage, 0.48-1.23 percentage, 8.02-9.85 percentage and 0.43-1.5 percentage, respectively. While, functional properties such as water absorption index, water solubility index and swelling power were found in the range of 5.38-6.26 (g/g), 1.95-4.94 percentage and 5.74-7.64 (g/g), respectively. The results showed that the functional properties of rice flour were greatly influenced by the compositional variations of various rice varieties. (author)

  17. Nutritional composition and heavy metal content of selected fruits in Nigeria

    Directory of Open Access Journals (Sweden)

    Koleayo Oluwafemi Omoyajowo

    2017-06-01

    Full Text Available Despite the nutritional benefits obtained from fruit consumption, the presence of heavy metals accompanying it from the environment draws scientific concerns as these affect human health. The aim of this study is to determine nutritional composition and heavy metal content of some commonly consumed fruits (apple, watermelon and sweet orange in Nigeria. Atomic absorption spectrophotometry was used to determine nickel, cadmium, chromium, lead and copper present in fruits. The results obtained show that the three fruit varieties contained considerable nutritional value that may meet body needs. Additionally, there was no significant difference in heavy metal concentrations of the fruits based on different locations (ANOVA F. test >0.05. This study posits that all the fruit varieties had the heavy metals within world health organisation (WHO permissible limit except apples. Apples sampled for different locations had nickel and chromium levels above the WHO permissible limits. Based on the observations in this study, there is a need for continuity of heavy metals inspection in agricultural products so as to prevent contamination and secure human safety.

  18. ANTIOXIDANT CAPACITY, MINERAL CONTENT AND ESSENTIAL OIL COMPOSITION FROM SELECT ALGERIAN MEDICINAL PLANTS

    Directory of Open Access Journals (Sweden)

    Hadjira Guenane1

    2017-10-01

    Full Text Available The objective of the present study was to analyze the total antioxidant capacity, minerals contents of four plants (Juniperus oxycedrus, Thymus capitatus, Laurus nobilis and Eruca vesicaria and chemical composition of the essential oils of the aerial parts of T. capitatus. Their antioxidant activity was assessed by DPPH, ABTS and FRAPS assays. Total phenol and flavonoid contents of the extracts were also determined. The results showed that the L. nobilis extract had the highest total phenolic and flavonoids contents (19.11 ± 0.22 mg GAE•g-1 dw, 4.47 ± 0.12 mg QE•g-1 dw, respectively. The extract of E. vesicaria had the highest value of TEAC for scavenging DPPH, whereas L. nobilis extract was active for ABTS and FRAP. GC/MS analysis revealed that the essential oil from the aerial parts of T. capitatus contained thirty-seven compounds; thymol was the major constituent (82.79 %. Atomic absorption spectroscopy showed high levels of Ca, K, Mg and Fe, and trace amounts of Zn, Cu and Mn in all four extracts.

  19. Molecular diversity of Annona species and proximate fruit composition of selected genotypes.

    Science.gov (United States)

    Anuragi, Hirdayesh; Dhaduk, Haresh L; Kumar, Sushil; Dhruve, Jitendra J; Parekh, Mithil J; Sakure, Amar A

    2016-12-01

    Understanding the genetic variation in germplasm is of utmost importance for crop improvement. Therefore, efforts were made to analyse the molecular marker based genetic diversity of 20 Annona genotypes from five different species of family Annonaceae. During analysis, a set of 11 RAPD primers yielded a total of 152 bands with 80.01 % polymorphism and PIC for RAPD ranged from 0.86 to 0.92 with a mean of 0.89. With 93.05 % polymorphism, 12 SSR primers produced 39 amplicons. The PIC for SSRs ranged from 0.169 to 0.694 with of average of 0.339. The dendrogram produced from pooled molecular data of 11 RAPD and 12 SSR primers showed seven clusters at a cutoff value of 0.78. The dendrogram discriminated all the Annona genotypes suggesting that significant genetic diversity was present among the genotypes. Proximate fruit composition study of nine fruiting genotypes of Annona revealed that A. squamosa possessed significantly higher amount of most of studies biochemical which gives an opportunity to fruit breeders to improve the other Annona species. Likewise, A. muricata being rich in seed oil content can be exploited in oil industries.

  20. Graft polymerization of vinyl acetate onto starch. Saponification to starch-g-poly(vinyl alcohol)

    International Nuclear Information System (INIS)

    Fanta, G.F.; Burr, R.C.; Doane, W.M.; Russell, C.R.

    1979-01-01

    Graft polymerizations of vinyl acetate onto granular cornstarch were initiated by cobalt-60 irradiation of starch-monomer-water mixtures, and ungrafted poly(vinyl acetate) was separated from the graft copolymer by benzene extraction. Conversions of monomer to polymer were quantitative at a radiation dose of 1.0 Mrad. Over half of the polymer was present as ungrafted poly(vinyl acetate) (grafting efficiency less than 50%), and the graft copolymer contained only 34% grafted synthetic polymer (34% add-on). Lower irradiation doses produced lower conversions of monomer to polymer and gave graft copolymers with lower % add-on. Addition of minor amounts of acrylamide, methyl acrylate, and methacrylic acid as comonomers produced only small increases in % add-on and grafting efficency. Grafting efficiency was increased to 70% when a monomer mixture containing about 10% methyl methacrylate was used. Grafting efficiency could be increased to over 90% if the graft polymerization of vinyl acetate--methyl methacrylate was carried out near 0 0 C; although conversion of monomers to polymer was low and grafted polymer contained 40 to 50% poly(methyl methacrylate). Selected graft copolymers were treated with methanolic sodium hydroxide to convert starch-g-poly(vinyl acetate) to starch-g-poly(vinyl alcohol). The molecular weight of the poly(vinyl alcohol) moiety was about 30,000. The solubility of starch-g-poly(vinyl alcohol) in hot water was less than 50; however, solubility could be increased by substituting either acid-modified or hypochlorite-oxidized for unmodified starch in the graft polymerization reaction. Vinyl acetate was also graft polymerized onto acid-modified starch which had been dispersed and partially solubilized by heating in water. A total irradiation dose of either 1.0 or 0.5 Mrad gave starch-g-poly

  1. A composite material based on nanoparticles of yttrium (III) oxide for the selective and sensitive electrochemical determination of acetaminophen

    International Nuclear Information System (INIS)

    Baytak, Aysegul Kutluay; Teker, Tugce; Duzmen, Sehriban; Aslanoglu, Mehmet

    2016-01-01

    An electrochemical sensor was prepared by modifying a glassy carbon electrode (GCE) with a composite of yttrium (III) oxide nanoparticles (Y 2 O 3 NPs) and carbon nanotubes (CNTs) for the determination of acetaminophen (ACT). Compared with a bare GCE and CNTs/GCE, the Y 2 O 3 NPs/CNTs/GCE exhibited a well-defined redox couple for ACT and highly enhanced the current response. The separations in the anodic and cathodic peak potentials (ΔE p ) for ACT were 552 mV, 24 mV and 10 mV at ba4re GCE, CNTs/GCE and Y 2 O 3 NPs/CNTs/GCE, respectively. The observation of only 10 mV of ΔE p for ACT at Y 2 O 3 NPs/CNTs/GCE was a clear indication of a great acceleration of the electrode process compared to bare GCE and GCE modified with CNTs. Also, L-ascorbic acid (L-AA) and L-tyrosine (L-TRY) did not interfere with the selective determination of ACT. Square wave voltammetry (SWV) was performed for the quantification of ACT. A linear plot was obtained for current responses versus the concentrations of ACT over the range from 1.0 × 10 −10 to 1.8 × 10 −8 M with a detection limit of 3.0 × 10 −11 M (based on 3S b /m). The proposed composite material provided high electrocatalytic activity, improved voltammetric behavior, good selectivity and good reproducibility. The accurate quantification of ACT makes the proposed electrode of great interest for the public health. - Highlights: • A voltammetric sensor based on yttrium oxide was prepared for the detection of ACT. • The proposed electrode has greatly accelerated the voltammetric process of ACT. • A detection limit of 0.03 nM was obtained for ACT. • The proposed electrode exhibited great selectivity for ACT in the presence of L-AA and L-TRY. • The composite material exhibited high sensitivity, good stability and excellent reproducibility.

  2. A composite material based on nanoparticles of yttrium (III) oxide for the selective and sensitive electrochemical determination of acetaminophen

    Energy Technology Data Exchange (ETDEWEB)

    Baytak, Aysegul Kutluay [Department of Medical Laboratory, Vocational School of Health Services, Harran University, Şanlıurfa 63510 (Turkey); Teker, Tugce; Duzmen, Sehriban [Department of Chemistry, Harran University, Şanlıurfa 63510 (Turkey); Aslanoglu, Mehmet, E-mail: maslanoglu@harran.edu.tr [Department of Chemistry, Harran University, Şanlıurfa 63510 (Turkey)

    2016-09-01

    An electrochemical sensor was prepared by modifying a glassy carbon electrode (GCE) with a composite of yttrium (III) oxide nanoparticles (Y{sub 2}O{sub 3}NPs) and carbon nanotubes (CNTs) for the determination of acetaminophen (ACT). Compared with a bare GCE and CNTs/GCE, the Y{sub 2}O{sub 3}NPs/CNTs/GCE exhibited a well-defined redox couple for ACT and highly enhanced the current response. The separations in the anodic and cathodic peak potentials (ΔE{sub p}) for ACT were 552 mV, 24 mV and 10 mV at ba4re GCE, CNTs/GCE and Y{sub 2}O{sub 3}NPs/CNTs/GCE, respectively. The observation of only 10 mV of ΔE{sub p} for ACT at Y{sub 2}O{sub 3}NPs/CNTs/GCE was a clear indication of a great acceleration of the electrode process compared to bare GCE and GCE modified with CNTs. Also, L-ascorbic acid (L-AA) and L-tyrosine (L-TRY) did not interfere with the selective determination of ACT. Square wave voltammetry (SWV) was performed for the quantification of ACT. A linear plot was obtained for current responses versus the concentrations of ACT over the range from 1.0 × 10{sup −10} to 1.8 × 10{sup −8} M with a detection limit of 3.0 × 10{sup −11} M (based on 3S{sub b}/m). The proposed composite material provided high electrocatalytic activity, improved voltammetric behavior, good selectivity and good reproducibility. The accurate quantification of ACT makes the proposed electrode of great interest for the public health. - Highlights: • A voltammetric sensor based on yttrium oxide was prepared for the detection of ACT. • The proposed electrode has greatly accelerated the voltammetric process of ACT. • A detection limit of 0.03 nM was obtained for ACT. • The proposed electrode exhibited great selectivity for ACT in the presence of L-AA and L-TRY. • The composite material exhibited high sensitivity, good stability and excellent reproducibility.

  3. Importance of chip selection and elaboration process on the aromatic composition of finished wines.

    Science.gov (United States)

    Rodríguez-Bencomo, Juan J; Ortega-Heras, Miriam; Pérez-Magariño, Silvia; González-Huerta, Carlos; González-San José, M Luisa

    2008-07-09

    The evolution of volatile compounds extracted from wood while being macerated for 1 month with four different commercial chips (different geographical origins and toasting degrees) was studied. Furthermore, the effect of the microoxygenation process between alcoholic and malolactic fermentation also was studied. The wood volatile compounds in wines macerated with the four types of chips evolved in the same way. However, the amounts of compounds extracted depended on the type of chip used. There were differences in the levels of vanillin, cis-whiskey lactone, furfural, trans-isoeugenol, and cis-isoeugenol in wines in accordance with the type of wood chips (French or American), and the last two compounds along with 5-methyl furfural presented differences that were directly related to the toast level. However, no effects of microoxygenation treatment on the extraction of volatile compounds extracted from chips were observed. Therefore, the results obtained in this study highlight the importance of chip selection on the aromatic characteristics of finished wines.

  4. Global blending optimization of laminated composites with discrete material candidate selection and thickness variation

    DEFF Research Database (Denmark)

    Sørensen, Søren N.; Stolpe, Mathias

    2015-01-01

    but is, however, convex in the original mixed binary nested form. Convexity is the foremost important property of optimization problems, and the proposed method can guarantee the global or near-global optimal solution; unlike most topology optimization methods. The material selection is limited....... In order to obtain large patchwise material candidate continuity while also accommodating variable laminate thickness, a bi-linear stiffness parameterization was introduced, causing a non-convex problem. In this present work, we introduce an alternative problem formulation that holds identical capabilities...... to a distinct choice among predefined numbers of candidates. The laminate thickness is variable but the number of plies must be integer. We solve the convex mixed binary non-linear programming problem by an outer approximation cutting-plane method augmented with a few heuristics to accelerate the convergence...

  5. Bone grafting options in children.

    Science.gov (United States)

    Betz, Randal R; Lavelle, William F; Samdani, Amer F

    2010-08-01

    Retrospective review of the literature. To review the current literature as well as recent trends in bone grafting techniques available for children. The currently accepted gold standard in bone grafting for adolescent idiopathic scoliosis (AIS) is autogenous iliac crest. Due to questions concerning complications such as donor site pain, other options have been explored, including various allograft sources, demineralized bone matrix, and bone morphogenetic protein. A review of the current medical literature was completed and additional case examples are presented. A review of the literature reveals that up to 31% of patients have persistent pain at 2 years post surgery when autogenous iliac crest bone graft is harvested. Allograft supplementation of local autograft has been demonstrated in the literature to be as effective as autogenous iliac crest bone grafting in contributing to a successful posterior spinal fusion in patients with AIS. Modern demineralized bone matrix formulations have been found in both animal models as well as in a recent retrospective clinical review to contribute to a successful posterior spinal fusion in AIS. Bone morphogenetic protein has been shown to contribute to a successful posterior spinal fusion in complex pediatric spinal deformity patients. At 2 years follow-up, patients who underwent a posterior instrumented spinal fusion that was not augmented with any bone graft appear to have successful spinal fusions. Although autogenous iliac bone graft remains the benchmark to which bone grafting materials are compared, other options including the placement of no bone graft at all provides similar fusion rates in patients with AIS.

  6. Proximate composition, minerals and vitamins content of selected vegetables grown in Peshawar

    International Nuclear Information System (INIS)

    Bangash, J.A.; Arif, M.; Khan, M.A.; Khan, F.; Amin-ur-Rrahma; Hussain, I.

    2011-01-01

    Ten vegetables namely Pot purslane, Spinach, Turnip, Garlic, Mustard (Sarson), Radish, Bitter gourd, Lady finger, Bath sponge and Brinjal were analyzed for their proximate composition, vitamin and mineral contents to evaluate their importance in human nutrition. The results showed that almost all vegetables contain appreciable amount of essential nutrients. The maximum content of moisture, carbohydrate, crude protein, crude fat, crude fiber, and ash recorded in these vegetables was (92.50 %, 26.88 %, 5.0%, 0.40%, 1.4% and 1.9%), respectively, with a minimum content (66.80 %, 3.91 %, 0.7%, 0.08%, 0.4% and 0.38%), respectively. Maximum concentration of macro minerals K, Ca, Mg, and Na, observed was (400, 210, 109, and 55) mg/100 g, respectively, with a minimum concentration (26, 15, 17, and 10) mg/100 g, respectively. Maximum concentration of micro minerals Fe, Cu, Zn, Mn and Cr observed was (29, 0.33, 3.05, 1.70, and 0.36) mg/100 g with a minimum concentration (2, 0.05, 0.43, 0.21, and 0.06) mg/100 g, respectively. Maximum concentration of water soluble vitamins i.e. thiamine, riboflavin, niacin and ascorbic acid recorded was (0.280, 0.190, 0.69, and 65) mg/100 g with a minimum concentration (0.011, 0.015, 0.23, and 4.00) mg/100 g, respectively. From this study it can be concluded that consumption of vegetables in different combinations could provide a reasonable daily recommended amount of essential nutrients for the maintenance of healthy life and normal body functioning. (author)

  7. Enhanced resin-composite bonding to zirconia framework after pretreatment with selected silane monomers.

    Science.gov (United States)

    Matinlinna, Jukka P; Lassila, Lippo V

    2011-03-01

    To evaluate the effect of five experimental silane monomer primers in vitro on the shear bond strength of a phosphate ester resin-composite cement bonded to a silicatized zirconia framework. A total of 144 planar zirconia (Procera AllZircon) specimens were subjected to tribochemical silica treatment, randomly divided into 12 sub-groups (n=12), and silanized with 1.0%(v/v) activated solutions of 3-acryloxypropyltrimethoxysilane, 3 glycidoxypropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, styrylethyltrimethoxysilane, and 3-isocyanatopropyltriethoxysilane, which had been prepared in 95% ethanol (pH 4.5). A ready-to-use 3-methacryloxypropyltrimethoxysilane (RelyX™ Ceramic Primer) was used as the control. One resincomposite cement (RelyX™ Unicem) stub was bonded to each silicatized and silanized zirconia specimen. Half of the specimen groups were dry-tested and half were thermo-cycled at 6000 cycles between 5°C and 55°C, with a constant dwelling time of 30s. The shear bond strengths of the cement stubs bonded to zirconia were measured using a universal testing machine using a constant cross-head speed of 1mm/min. The silane primer activation was evaluated using Fourier-transform infrared spectroscopy. The highest shear bond strength was obtained for 3-acryloxypropyltrimethoxysilane in dry storage, 11.7 MPa (SD, 2.3 MPa) and after thermo-cycling 17.6 (4.1) MPa for glycidoxypropyltrimethoxysilane. The lowest shear bond strength values were obtained with control silane: in dry storage, 4.5 (1.3) MPa, after thermo-cycling 6.5 (2.6) MPa. Thermo-cycling increased the bond strengths significantly (ANOVA, psilane (ANOVA, pSilanization with five experimental silane primers in vitro produced significantly greater shear bond strengths than the ready-to-use control silane. Copyright © 2010 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  8. Richness, composition and relationships of the floras of selected forests in southern Africa

    Directory of Open Access Journals (Sweden)

    C. J. Geldenhuys

    1992-10-01

    Full Text Available Species lists of 14 widely separated forests representing particular geographic regions in southern Africa were used to study the size and composition of the individual floras, the similarities between them, and possible determinants of the observed patterns. The forests contain 1 438 species which belong to 155 families and 661 genera. The growth form spectra show specific patterns amongst the individual forests such as an abundance of ferns in montane forests, and of woody plants and vines in coastal forests. The richness of a forest flora increases with increasing altitudinal range within the forest. Significant linear species-area relationships exist for both woody and herbaceous species, but explain only 30% and 38% of the variation respectively in the size of the floras. In a multiple regression model the number of dispersal corridors, the proximity to other forests and mean altitude explained 81% of the variation in the number of woody species. The number of landscape types and of dispersal corridors explained 75% of the variation in number of herbaceous species. Several other factors contribute to the disproportionately large floras of relatively small forests such as at Umtamvuna, Sabie and Richards Bay. A high proportion of unique taxa are present (30% woody and 42% herbaceous species. The shared taxa show definite trends of the southward attenuation of species and the presence of elements of the Afromontane and Indian Ocean Coastal Regions.In conclusion, it is suggested that the southern Cape forests have been isolated from forests along the escarpment and mountains to the east since at least the Pliocene due to the Sundays River valley which stretches from the coast to the escarpment in the arid interior.

  9. Influence of Selected Alkoxysilanes on Dispersive Properties and Surface Chemistry of Titanium Dioxide and TiO2–SiO2 Composite Material

    Directory of Open Access Journals (Sweden)

    Katarzyna Siwińska-Stefańska

    2012-01-01

    Full Text Available The paper reports on characterisation of titanium dioxide and coprecipitated TiO2–SiO2 composite material functionalised with selected alkoxysilanes. Synthetic composite material was obtained by an emulsion method with cyclohexane as the organic phase, titanium sulfate as titanium precursor, and sodium silicate solution as precipitating agent were applied. Structures of titania and composite material samples were studied by the wide angle X-ray scattering method. The chemical composition of TiO2–SiO2 composite material precipitated was evaluated based on the energy dispersive X-ray spectroscopy technique. The functionalised TiO2 and TiO2–SiO2 composite material were thoroughly characterised to determine the yield of functionalisation with silanes. The characterisation included determination of dispersion and morphology of the systems (particle size distribution, scanning electron microscope images, adsorption properties (nitrogen adsorption isotherms, and electrokinetic properties (zeta potential.

  10. Safe disposal of radioactive iodide ions from solutions by Ag2O grafted sodium niobate nanofibers.

    Science.gov (United States)

    Mu, Wanjun; Li, Xingliang; Liu, Guoping; Yu, Qianhong; Xie, Xiang; Wei, Hongyuan; Jian, Yuan

    2016-01-14

    Radioactive iodine isotopes are released into the environment by the nuclear industry and medical research institutions using radioactive materials, and have negative effects on organisms living within the ecosystem. Thus, safe disposal of radioactive iodine is necessary and crucial. For this reason, the uptake of iodide ions was investigated in Ag2O nanocrystal grafted sodium niobate nanofibers, which were prepared by forming a well-matched phase coherent interface between them. The resulting composite was applied as an efficient adsorbent for I(-) anions by forming an AgI precipitate, which also remained firmly attached to the substrates. Due to their one-dimensional morphology, the new adsorbents can be easily dispersed in liquids and readily separated after purification. This significantly enhances the adsorption efficiency and reduces the separation costs. The change in structure from the pristine sodium niobate to Ag2O anchored sodium niobate and to the used adsorbent was examined by using various characterization techniques. The effects of Ag(+) concentration, pH, equilibration time, ionic strength and competing ions on the iodide ion removal ability of the composite were studied. The Ag2O nanocrystal grafted sodium niobate adsorbent showed a high adsorption capacity and excellent selectivity for I(-) anions in basic solutions. Our results are useful for the further development of improved adsorbents for removing I(-) anions from basic wastewater.

  11. Composites of ionic liquid and amine-modified SAPO 34 improve CO2 separation of CO2-selective polymer membranes

    Science.gov (United States)

    Hu, Leiqing; Cheng, Jun; Li, Yannan; Liu, Jianzhong; Zhang, Li; Zhou, Junhu; Cen, Kefa

    2017-07-01

    Mixed matrix membranes with ionic liquids and molecular sieve particles had high CO2 permeabilities, but CO2 separation from small gas molecules such as H2 was dissatisfied because of bad interfacial interaction between ionic liquid and molecular sieve particles. To solve that, amine groups were introduced to modify surface of molecular sieve particles before loading with ionic liquid. SAPO 34 was adopted as the original filler, and four mixed matrix membranes with different fillers were prepared on the outer surface of ceramic hollow fibers. Both surface voids and hard agglomerations disappeared, and the surface became smooth after SAPO 34 was modified by amine groups and ionic liquid [P66614][2-Op]. Mixed matrix membranes with composites of amine-modified SAPO 34 and ionic liquid exhibited excellent CO2 permeability (408.9 Barrers) and CO2/H2 selectivity (22.1).

  12. Models for formation of macroheterogeneous structure in radiation-grafted polymers

    International Nuclear Information System (INIS)

    Babkin, I.Yu.; Burukhin, S.B.; Maksimov, A.F.

    1994-01-01

    Mathematical models, which describe the formation of grafted polymer layer with respect to variations in sorption and kinetic characteristics due to the changes in composition of the modified polymer and grafted polymer under variable boundary conditions were obtained. The influence of heat effect of polymerization reaction on concentration profiles was estimated. Taking into account the nonlinear diffusion kinetics, the conditions providing diffuse and step profiles of concentration of grafted polymer in polymer matrix were revealed. Step concentration profiles were shown to be associated with a nonlinear dependence of diffusion and kinetic parameters of polymerization on the composition of modified polymer. 22 refs.; 11 figs.; 2 tabs

  13. Influence of antibiotic selection on genetic composition of Escherichia coli populations from conventional and organic dairy farms.

    Science.gov (United States)

    Walk, Seth T; Mladonicky, Janice M; Middleton, Jaclyn A; Heidt, Anthony J; Cunningham, Julie R; Bartlett, Paul; Sato, Kenji; Whittam, Thomas S

    2007-10-01

    The widespread agricultural use of antimicrobials has long been considered a crucial influence on the prevalence of resistant genes and bacterial strains. It has been suggested that antibiotic applications in agricultural settings are a driving force for the development of antimicrobial resistance, and epidemiologic evidence supports the view that there is a direct link between resistant human pathogens, retail produce, farm animals, and farm environments. Despite such concerns, little is understood about the population processes underlying the emergence and spread of antibiotic resistance and the reversibility of resistance when antibiotic selective pressure is removed. In this study, hierarchical log-linear modeling was used to assess the association between farm type (conventional versus organic), age of cattle (calf versus cow), bacterial phenotype (resistant versus susceptible), and the genetic composition of Escherichia coli populations (E. coli Reference Collection [ECOR] phylogroup A, B1, B2, or D) among 678 susceptible and resistant strains from a previously published study of 60 matched dairy farms (30 conventional and 30 organic) in Wisconsin. The analysis provides evidence for clonal resistance (ampicillin resistance) and genetic hitchhiking (tetracycline resistance [Tet(r)]), estimated the rate of compositional change from conventional farming to organic farming (mean, 8 years; range, 3 to 15 years), and discovered a significant association between low multidrug resistance, organic farms, and strains of the numerically dominant phylogroup B1. These data suggest that organic farming practices not only change the frequency of resistant strains but also impact the overall population genetic composition of the resident E. coli flora. In addition, the results support the hypothesis that the current prevalence of Tet(r) loci on dairy farms has little to do with the use of this antibiotic.

  14. Characteristics and chemical compositions of particulate matter collected at the selected metro stations of Shanghai, China

    International Nuclear Information System (INIS)

    Guo, Li; Hu, Yunjie; Hu, Qingqing; Lin, Jun; Li, Chunlin; Chen, Jianmin; Li, Lina; Fu, Hongbo

    2014-01-01

    A campaign was conducted to assess and compare the air quality at the different metro platforms at Shanghai City, focusing on particulate matter (PM) levels, chemical compositions, morphology and mineralogy, as well as species of iron. Our results indicated that the average PM 2.5 concentrations for the three metro lines were 177.7 μg/m 3 , 105.7 μg/m 3 and 82.5 μg/m 3 , respectively, and the average PM 1 concentrations for the three lines were 122.3 μg/m 3 , 84.1 μg/m 3 and 59.6 μg/m 3 , respectively. Fe, Mn, Cr, Cu, Sr, Ba and Pb concentrations in all of the sampling sites were significantly higher than that in the urban ambient air, implicating that these trace metals may be associated with the metro systems working. Individual airborne dusts were studied for morphology and mineralogy characteristics. The results revealed that the presence of most individual particles were with no definite shape and most of them were with a large metal content. Furthermore, Fe-rich particles had significantly higher abundance in the metro systems, which were more frequently encountered in the underground lines than the aboveground line. The 2D distribution map of an interested Fe-rich particle showed an uneven Fe distribution, implying that a hollow or core of other substance exists in the particle center during the formation process. Cluster analysis revealed that Fe-rich particles were possibly a mixture of Fe species. Fitting of X-ray absorption near-edge fine structure spectra (XANES) showed the main iron species within the particles collected from the three contrasting metro lines of Shanghai to be hematite, magnetite, iron-metal and mineral Fe. Hematite and mineral Fe were all found in three lines, while magnetite only existed in aboveground metro line. Iron-metal was determined in both the older and younger underground lines, based on the X-ray diffraction (XRD) analysis. As diverse Fe species have different physical–chemical characteristics and toxicity, the

  15. Germination conditions affect selected quality of composite wheat-germinated brown rice flour and bread formulations.

    Science.gov (United States)

    Charoenthaikij, Phantipha; Jangchud, Kamolwan; Jangchud, Anuvat; Prinyawiwatkul, Witoon; Tungtrakul, Patcharee

    2010-08-01

    Brown rice has been reported to be more nutritious after germination. Germinated brown rice flours (GBRFs) from different steeping conditions (in distilled water [DI, pH 6.8] or in a buffer solution [pH 3] for either 24 or 48 h at 35 degrees C) were evaluated in this study. GBRF obtained from brown rice steeped at pH 3 for 48 h contained the highest amount of free gamma aminobutyric acid (GABA; 67 mg/100 g flour). The composite flour (wheat-GBRF) at a ratio of 70 : 30 exhibited significantly lower peak viscosity (PV) (56.99 - 132.45 RVU) with higher alpha-amylase activity (SN = 696 - 1826) compared with those of wheat flour (control) (PV = 136.46 RVU and SN = 1976). Bread formulations, containing 30% GBRF, had lower loaf volume and greater hardness (P bread. However, the hardness of bread containing 30% GBRF (except at pH 6.8 and 24 h) was significantly lower than that of bread containing 30% nongerminated brown rice flour (BRF). Acceptability scores for aroma, taste, and flavor of breads prepared with or without GBRFs (30% substitution) were not significantly different, with the mean score ranging from 6.1 (like slightly) to 7 (like moderately). Among the bread formulations containing GBRF, the one with GBRF prepared after 24 h steeping at pH 3 had a slightly higher (though not significant) overall liking score (6.8). This study demonstrated that it is feasible to substitute wheat flour with up to 30% GBRF in bread formulation without negatively affecting sensory acceptance. Practical Application: Our previous study revealed that flours from germinated brown rice have better nutritional properties, particularly gamma-aminobutyric acid (GABA), than the nongerminated one. This study demonstrated feasibility of incorporating up to 30% germinated brown rice flour in a wheat bread formulation without negatively affecting sensory acceptance. In the current United States market, this type of bread may be sold as frozen bread which would have a longer shelf life. Further

  16. Desalination of fish sauce by electrodialysis: effect on selected aroma compounds and amino acid compositions.

    Science.gov (United States)

    Chindapan, Nathamol; Devahastin, Sakamon; Chiewchan, Naphaporn; Sablani, Shyam S

    2011-09-01

    Fish sauce is an ingredient that exhibits unique flavor and is widely used by people in Southeast Asia. Fish sauce, however, contains a significant amount of salt (sodium chloride). Recently, electrodialysis (ED) has been successfully applied to reduce salt in fish sauce; however, no information is available on the effect of ED on changes in compounds providing aroma and taste of ED-treated fish sauce. The selected aroma compounds, amino acids, and sensory quality of the ED-treated fish sauce with various salt concentrations were then analyzed. The amounts of trimethylamine, 2,6-dimethylpyrazine, phenols, and all carboxylic acids except for hexanoic acid significantly decreased, whereas benzaldehyde increased significantly when the salt removal level was higher. The amounts of all amino acids decreased with the increased salt removal level. Significant difference in flavor and saltiness intensity among ED-treated fish sauce with various salt concentrations, as assessed by a discriminative test, were observed. Information obtained in this work can serve as a guideline for optimization of a process to produce low-sodium fish sauce by ED. It also forms a basis for further in-depth sensory analysis of low-sodium fish sauce. © 2011 Institute of Food Technologists®

  17. Digital selective fabrication of micro/nano-composite structured TiO2 nanorod arrays by laser direct writing

    Science.gov (United States)

    Jiang, Wei; He, Xiaoning; Liu, Hongzhong; Yin, Lei; Shi, Yongsheng; Ding, Yucheng

    2014-11-01

    In this article, we report on the digital selective fabrication of micro/nano-composite structured TiO2 nanorod arrays by laser direct writing. The pattern of TiO2 nanorod arrays can be easily designed and fabricated by laser scanning technology integrated with a computer-aided design system, which allows a high degree of freedom corresponding to the various pattern design demands. The approach basically involves the hydrothermal growth of TiO2 nanorod arrays on a transparent conductive substrate, the micropattern of TiO2 nanorod arrays and surface fluorination treatment. With these micro/nano-composite TiO2 nanorod array based films, we have demonstrated superhydrophilic patterned TiO2 nanorod arrays with rapid water spreading ability and superhydrophobic patterned TiO2 nanorod arrays with an excellent droplet bouncing effect and a good self-cleaning performance. The dynamic behaviours of the water droplets observed on the patterned TiO2 nanorod arrays were demonstrated by experiments and simulated by a finite element method. The approaches we will show are expected to provide potential applications in fields such as self-cleaning, surface protection, anticrawling and microfluidic manipulation.

  18. Seasonal variation in soil seed bank size and species composition of selected habitat types in Maputaland, South Africa

    Directory of Open Access Journals (Sweden)

    M. J. S. Kellerman

    2007-08-01

    Full Text Available Seasonal variation in seed bank size and species composition of five selected habitat types within the Tembe Elephant Park. South Africa, was investigated. At three-month intervals, soil samples were randomly collected from five different habitat types: a, Licuati forest; b, Licuati thicket; c, a bare or sparsely vegetated zone surrounding the forest edge, referred to as the forest/grassland ecotone; d, grassland; and e, open woodland. Most species in the seed bank flora were either grasses, sedges, or forbs, with hardly any evidence of woody species. The Licuati forest and thicket soils produced the lowest seed densities in all seasons.  Licuati forest and grassland seed banks showed a two-fold seasonal variation in size, those of the Licuati thicket and woodland a three-fold variation in size, whereas the forest/grassland ecotone maintained a relatively large seed bank all year round. The woodland seed bank had the highest species richness, whereas the Licuati forest and thicket soils were poor in species. Generally, it was found that the greatest correspondence in species composition was between the Licuati forest and thicket, as well as the forest/grassland ecotone and grassland seed bank floras.

  19. Synthesis and characterization of a new activated carbon supported ammonium molybdophosphate composite and its cesium-selective adsorption properties

    International Nuclear Information System (INIS)

    Feng Miao; Wang Li; Zhao Yongsheng; Liu Chunxia; Chen Zhen; Yan Liang; Tian Gan; Wang Hang; Li Shoujian

    2010-01-01

    A new Cs + adsorbent, activated carbon loaded ammonium molybdophosphate (AMP-AC) was prepared by repeating batch reaction of H 3 PO 4 and (NH 4 ) 6 Mo 7 O 24 . The surface of the activated carbon particles was coated with AMP microcrystals through a controlled crystallization process. The X-ray diffraction (XRD) analysis identified the AMP loaded on AC with the formula of (NH 4 ) 3 PO 4 (MoO 3 ) 12 .4H 2 O. Scanning electron microscope images demonstrated that the fine AMP crystals was successfully immobilized and uniformly distributed on the porous carbon substrate. The effects of medium acidity, contact time, temperature and competing ions on Cs + uptake by the composite were investigated. The results show that the as-prepared adsorbent keeps high selectivity and adsorption capacity (∝0.75 mmol/g) for Cs + in acidic feed solution (0.1 M HNO 3 ). even in the presence of plentiful competing cations. Na + , Zn 2+ , Sr 2+ , Cr 3+ and La 3+ , while activated carbon itself has no specific affinity for Cs + . The adsorption process could be described by Langmuir adsorption equations. There is no significant difference (9.4%) on Cs + adsorption by the composite during system temperature changing from 298 to 348 K. (orig.)

  20. [Changes in chemical composition of selected food products in the province of Katowice].

    Science.gov (United States)

    Lorek, E; Barczak, M; Królik, K

    1994-01-01

    The levels of Mg, Fe, Mn, Cu, Pb and Cd were determined in fresh vegetables obtained from central storerooms of the WSO in Katowice which were intended for market in that Province. Vegetable samples were taken from the stores twice in the months from September to March in the years 1986-1987. At the same time similar analyses were done of raw milk and milk for consumption from the market and from certain dairy cooperatives in the Province. Besides the above metals, in the samples dry mass, ash, protein (by Kjeldahl method), calorie values (by burning in calorimetric bomb ZKL-4) were determined. The study included these mineral components which are necessary in human physiological requirements, and those which can be toxic if consumed in excess, and also those which cumulate selectively in plants and in animal and human organisms. The mutual relationships were evaluated of these components in the analysed food products based on calculated correlation coefficients. After the chemical analysis of these products it was found that the levels of Mg, Fe, Cu, Zn, Mn and Cd and Pb varied depending on the product and site of origin of the sample. The levels of heavy metals, such as Cd and Pb, were exceeding the acceptable values in the edible parts of vegetables grown in the Province of Katowice and intended for the market in that Province. The lowest levels of toxic metals and the highest content of mineral components indispensable for physiological functions were found in the vegetables brought from the neighbouring Province of Kielce.(ABSTRACT TRUNCATED AT 250 WORDS)

  1. The Impact of Liver Graft Injury on Cancer Recurrence Posttransplantation.

    Science.gov (United States)

    Li, Chang-Xian; Man, Kwan; Lo, Chung-Mau

    2017-11-01

    Liver transplantation is the most effective treatment for selected patients with hepatocellular carcinoma. However, cancer recurrence, posttransplantation, remains to be the critical issue that affects the long-term outcome of hepatocellular carcinoma recipients. In addition to tumor biology itself, increasing evidence demonstrates that acute-phase liver graft injury is a result of hepatic ischemia reperfusion injury (which is an inevitable consequence during liver transplantation) and may promote cancer recurrence at late phase posttransplantation. The liver grafts from living donors, donors after cardiac death, and steatotic donors have been considered as promising sources of organs for liver transplantation and are associated with high incidence of liver graft injury. The acute-phase liver graft injury will trigger a series of inflammatory cascades, which may not only activate the cell signaling pathways regulating the tumor cell invasion and migration but also mobilize the circulating progenitor and immune cells to facilitate tumor recurrence and metastasis. The injured liver graft may also provide the favorable microenvironment for tumor cell growth, migration, and invasion through the disturbance of microcirculatory barrier function, induction of hypoxia and angiogenesis. This review aims to summarize the latest findings about the role and mechanisms of liver graft injury resulted from hepatic ischemia reperfusion injury on tumor recurrence posttransplantation, both in clinical and animal cohorts.

  2. Characterization of the grafting copolymer EPDM-SAN

    International Nuclear Information System (INIS)

    Turchette, Renato; Felisberti, Maria Isabel

    2001-01-01

    This work aims the characterization of the grafting copolymer EPDM-SAN. This copolymer presents a fraction of free SAN chains, which was extracted by solubilization in chloroform followed of precipitation of the grafting copolymer EPDM-g-SAN in acetone. The EPDM-SAN and EPDM-g-SAN were characterized by 13 C NMR, DSC, TGA and SEM. EPDM-SAN contain 23 wt% of free SAN and 77 wt% of EPDM-g-SAN. Both materials are heterogeneous and the thermal and thermo-oxidative degradation are independent of the composition. (author)

  3. Ionic membranes obtained by radiation grafting for the use in waste treatment

    International Nuclear Information System (INIS)

    Hegazy, E.A.; Abd El-Rehim, H.A.; El-Hag Ali, A.; Khalifa, N.A.

    1998-01-01

    The selectivity of polyethylene-Styrene/Maleic anhydride graft copolymer membranes LDPE-g-P(Sty/MAn) prepared by γ irradiation towards different metal ions such as Fe, Cu, Cd and Pb was studied for its possible use in waste water treatment. The sorption capacity of metal ions by the sorbent membranes via their functional groups was determined by using atomic absorption, X-ray fluorescence and UV spectrophotometry. The effect of immersion periods needed for maximum capacity, pH of the feed metal solution and degree of grafting on the sorption capacity were also investigated. Improvement in the chelation property of the grafted membranes was also carried out by further chemical treatment with hydroxylamine-HCl and thiosemicarbazide. The selectivity of untreated grafted films towards Fe 3+ is pronounced in feed solution containing Fe 3+ , Pb 2+ , Co 2+ , Cd 2+ and Cu 2+ . The selectivity of the treated grafted films with hydroxylamine-CHl towards Fe 2+ is more remarkable. The introduction of thiosemicarbazide groups in the Sty/MAn graft chains resulted in transfer of the membrane selectivity from Fe 3+ to Cu 2+ . Also, the recovery of Hg from aqueous solution that contain other metal ions was studied. Thermal stability of the untreated and metal ion containing grafted copolymers was determined using TGA and DTA. TGA results showed that the thermal deposition of the grafted copolymer in the presence of chelated Cu 2+ occurred at higher temperatures than that for the grafted copolymer. Thermal stability for the membrane that contains metal ions is of the order Cu>Cr>Fe> free metal grafted membranes. These grafted membranes possessed good properties toward metal chelation and practical interest for the waste water treatment of heavy and toxic metals

  4. Graft intolerance syndrome requiring graft nephrectomy after late kidney graft failure: can it be predicted? A retrospective cohort study.

    Science.gov (United States)

    Bunthof, Kim L W; Verhoeks, Carmen M; van den Brand, Jan A J G; Hilbrands, Luuk B

    2018-02-01

    Graft nephrectomy is recommended in case of early graft failure. When the graft fails more than 3-6 months after transplantation, it is current practice to follow a wait-and-see policy. A common indication for graft removal is the graft intolerance syndrome. We aimed to create a risk prediction model for the occurrence of graft intolerance resulting in graft nephrectomy. We collected data of kidney transplantations performed in our center between 1980 and 2010 that failed at least 6 months after transplantation. We evaluated the association between baseline characteristics and the occurrence of graft nephrectomy because of graft intolerance using a competing risk regression model. Prognostic factors were included in a multivariate prediction model. In- and exclusion criteria were met in 288 cases. In 48 patients, the graft was removed because of graft intolerance. Donor age, the number of rejections, and shorter graft survival were predictive factors for graft nephrectomy because of the graft intolerance syndrome. These factors were included in a prediction rule. Using donor age, graft survival, and the number of rejections, clinicians can predict the need for graft nephrectomy with a reasonable accuracy. © 2017 Steunstichting ESOT.

  5. Surface grafted polymer brushes: potential applications in dengue biosensors

    International Nuclear Information System (INIS)

    Baratela, Fernando Jose Costa; Higa, Olga Zazuco; Faria, Henrique Antonio Mendonca de; Queiroz, Alvaro Antonio Alencar de

    2013-01-01

    A polymer brush membrane-based ultrasensitive biosensor for dengue diagnosis was constructed using poly(hydroxyethyl methacrylate) (PHEMA) brushes immobilized onto low density polyethylene (LDPE) films. LDPE surface films were initially modified by Ar + ion irradiation to activate the polymer surface. Subsequently, graft polymerization of 2-hydroxyethyl methacrylate onto the activated LDPE surface was carried out under aqueous conditions to create patterned polymer brushes of PHEMA. The grafted PHEMA brushes were characterized by Fourier transform-infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and contact angle analysis. The SEM observations showed that selective surface activation with Ar+ implantation and graft polymerization on the selectively activated surface had occurred. The PHEMA brushes were electrically characterized in the presence of concentrations of human immunoglobulin (IgG). The proposed amperometric biosensor was successfully used for determination of IgG in physiologic samples with excellent responses. (author)

  6. Surface grafted polymer brushes: potential applications in dengue biosensors

    Energy Technology Data Exchange (ETDEWEB)

    Baratela, Fernando Jose Costa; Higa, Olga Zazuco, E-mail: ozahiga@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Faria, Henrique Antonio Mendonca de; Queiroz, Alvaro Antonio Alencar de, E-mail: alencar@unifei.edu.br [Universidade Federal de Itajuba (UNIFEI), Itajuba, MG (Brazil). Instituto de Fisica e Quimica

    2013-07-01

    A polymer brush membrane-based ultrasensitive biosensor for dengue diagnosis was constructed using poly(hydroxyethyl methacrylate) (PHEMA) brushes immobilized onto low density polyethylene (LDPE) films. LDPE surface films were initially modified by Ar{sup +} ion irradiation to activate the polymer surface. Subsequently, graft polymerization of 2-hydroxyethyl methacrylate onto the activated LDPE surface was carried out under aqueous conditions to create patterned polymer brushes of PHEMA. The grafted PHEMA brushes were characterized by Fourier transform-infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and contact angle analysis. The SEM observations showed that selective surface activation with Ar+ implantation and graft polymerization on the selectively activated surface had occurred. The PHEMA brushes were electrically characterized in the presence of concentrations of human immunoglobulin (IgG). The proposed amperometric biosensor was successfully used for determination of IgG in physiologic samples with excellent responses. (author)

  7. Tough and Sustainable Graft Block Copolymer Thermoplastics

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jiuyang; Li, Tuoqi; Mannion, Alexander M.; Schneiderman, Deborah K.; Hillmyer, Marc A.; Bates, Frank S. (UMM)

    2016-03-15

    Fully sustainable poly[HPMC-g-(PMVL-b-PLLA)] graft block copolymer thermoplastics were prepared from hydroxypropyl methylcellulose (HPMC), β-methyl-δ-valerolactone (MVL), and l-lactide (LLA) using a facile two-step sequential addition approach. In these materials, rubbery PMVL functions as a bridge between the semirigid HPMC backbone and the hard PLLA end blocks. This specific arrangement facilitates PLLA crystallization, which induces microphase separation and physical cross-linking. By changing the backbone molar mass or side chain composition, these thermoplastic materials can be easily tailored to access either plastic or elastomeric behavior. Moreover, the graft block architecture can be utilized to overcome the processing limitations inherent to linear block polymers. Good control over molar mass and composition enables the deliberate design of HPMC-g-(PMVL-b-PLLA) samples that are incapable of microphase separation in the melt state. These materials are characterized by relatively low zero shear viscosities in the melt state, an indication of easy processability. The simple and scalable synthetic procedure, use of inexpensive and renewable precursors, and exceptional rheological and mechanical properties make HPMC-g-(PMVL-b-PLLA) polymers attractive for a broad range of applications.

  8. Forming a single layer of a composite powder based on the Ti-Nb system via selective laser melting (SLM)

    Science.gov (United States)

    Saprykin, A. A.; Sharkeev, Yu P.; Ibragimov, E. A.; Babakova, E. V.; Dudikhin, D. V.

    2016-07-01

    Alloys based on the titanium-niobium system are widely used in implant production. It is conditional, first of all, on the low modulus of elasticity and bio-inert properties of an alloy. These alloys are especially important for tooth replacement and orthopedic surgery. At present alloys based on the titanium-niobium system are produced mainly using conventional metallurgical methods. The further subtractive manufacturing an end product results in a lot of wastes, increasing, therefore, its cost. The alternative of these processes is additive manufacturing. Selective laser melting is a technology, which makes it possible to synthesize products of metal powders and their blends. The point of this technology is laser melting a layer of a powdered material; then a sintered layer is coated with the next layer of powder etc. Complex products and working prototypes are made on the base of this technology. The authors of this paper address to the issue of applying selective laser melting in order to synthesize a binary alloy of a composite powder based on the titanium-niobium system. A set of 10x10 mm samples is made in various process conditions. The samples are made by an experimental selective laser synthesis machine «VARISKAF-100MB». The machine provides adjustment of the following process variables: laser emission power, scanning rate and pitch, temperature of powder pre-heating, thickness of the layer to be sprinkled, and diameter of laser spot focusing. All samples are made in the preliminary vacuumized shielding atmosphere of argon. The porosity and thickness of the sintered layer related to the laser emission power are shown at various scanning rates. It is revealed that scanning rate and laser emission power are adjustable process variables, having the greatest effect on forming the sintered layer.

  9. Differences in the Selection Bottleneck between Modes of Sexual Transmission Influence the Genetic Composition of the HIV-1 Founder Virus.

    Directory of Open Access Journals (Sweden)

    Damien C Tully

    2016-05-01

    Full Text Available Due to the stringent population bottleneck that occurs during sexual HIV-1 transmission, systemic infection is typically established by a limited number of founder viruses. Elucidation of the precise forces influencing the selection of founder viruses may reveal key vulnerabilities that could aid in the development of a vaccine or other clinical interventions. Here, we utilize deep sequencing data and apply a genetic distance-based method to investigate whether the mode of sexual transmission shapes the nascent founder viral genome. Analysis of 74 acute and early HIV-1 infected subjects revealed that 83% of men who have sex with men (MSM exhibit a single founder virus, levels similar to those previously observed in heterosexual (HSX transmission. In a metadata analysis of a total of 354 subjects, including HSX, MSM and injecting drug users (IDU, we also observed no significant differences in the frequency of single founder virus infections between HSX and MSM transmissions. However, comparison of HIV-1 envelope sequences revealed that HSX founder viruses exhibited a greater number of codon sites under positive selection, as well as stronger transmission indices possibly reflective of higher fitness variants. Moreover, specific genetic "signatures" within MSM and HSX founder viruses were identified, with single polymorphisms within gp41 enriched among HSX viruses while more complex patterns, including clustered polymorphisms surrounding the CD4 binding site, were enriched in MSM viruses. While our findings do not support an influence of the mode of sexual transmission on the number of founder viruses, they do demonstrate that there are marked differences in the selection bottleneck that can significantly shape their genetic composition. This study illustrates the complex dynamics of the transmission bottleneck and reveals that distinct genetic bottleneck processes exist dependent upon the mode of HIV-1 transmission.

  10. Differences in the Selection Bottleneck between Modes of Sexual Transmission Influence the Genetic Composition of the HIV-1 Founder Virus.

    Science.gov (United States)

    Tully, Damien C; Ogilvie, Colin B; Batorsky, Rebecca E; Bean, David J; Power, Karen A; Ghebremichael, Musie; Bedard, Hunter E; Gladden, Adrianne D; Seese, Aaron M; Amero, Molly A; Lane, Kimberly; McGrath, Graham; Bazner, Suzane B; Tinsley, Jake; Lennon, Niall J; Henn, Matthew R; Brumme, Zabrina L; Norris, Philip J; Rosenberg, Eric S; Mayer, Kenneth H; Jessen, Heiko; Kosakovsky Pond, Sergei L; Walker, Bruce D; Altfeld, Marcus; Carlson, Jonathan M; Allen, Todd M

    2016-05-01

    Due to the stringent population bottleneck that occurs during sexual HIV-1 transmission, systemic infection is typically established by a limited number of founder viruses. Elucidation of the precise forces influencing the selection of founder viruses may reveal key vulnerabilities that could aid in the development of a vaccine or other clinical interventions. Here, we utilize deep sequencing data and apply a genetic distance-based method to investigate whether the mode of sexual transmission shapes the nascent founder viral genome. Analysis of 74 acute and early HIV-1 infected subjects revealed that 83% of men who have sex with men (MSM) exhibit a single founder virus, levels similar to those previously observed in heterosexual (HSX) transmission. In a metadata analysis of a total of 354 subjects, including HSX, MSM and injecting drug users (IDU), we also observed no significant differences in the frequency of single founder virus infections between HSX and MSM transmissions. However, comparison of HIV-1 envelope sequences revealed that HSX founder viruses exhibited a greater number of codon sites under positive selection, as well as stronger transmission indices possibly reflective of higher fitness variants. Moreover, specific genetic "signatures" within MSM and HSX founder viruses were identified, with single polymorphisms within gp41 enriched among HSX viruses while more complex patterns, including clustered polymorphisms surrounding the CD4 binding site, were enriched in MSM viruses. While our findings do not support an influence of the mode of sexual transmission on the number of founder viruses, they do demonstrate that there are marked differences in the selection bottleneck that can significantly shape their genetic composition. This study illustrates the complex dynamics of the transmission bottleneck and reveals that distinct genetic bottleneck processes exist dependent upon the mode of HIV-1 transmission.

  11. Development of EPDM based thermoplastic elastomers for oil resistant applications: optimization of radiation grafting parameters

    International Nuclear Information System (INIS)

    Chaudhari, C.V.; Dubey, K.A.; Bhardwaj, Y.K.; Sabharwal, S.

    2008-01-01

    Full text: Ethylene-propylene diene terpolymer (EPDM) is currently among the most industrially useful elastomers because of its certain unique properties like excellent heat resistance, resistance towards ozone deterioration, high impact strength. However EPDM has a serious drawback of weak adhesion properties and tendency to swell in contact with paraffin oil and aromatic hydrocarbons. Blending EPDM with suitable polar elastomers or grafting polar polymer chains onto EPDM is an easy method to overcome this drawback. Radiation grafting of Acrylonitrile (ACN) on EPDM provides an easy and effective method of incorporating ACN uniformly on the EPDM backbone. Grafting of ACN on EPDM is expected to result grafted copolymer with better oil resistance, hardness and better compatibility with polar polymer matrices. In the present study radiation induced grafting of ACN onto EPDM rubber film was investigated by mutual radiation grafting technique. Effect of experimental variables viz. radiation dose, dose rate, types of solvents and monomer content on extent of grafting was studied. The solvent composition of Acetone:CCl 4 (20:80) was found to be the optimum mixture which resulted in highest degree of grafting. It was found that the degree of grafting increases with radiation dose, monomer content and decreases with dose rate

  12. Graft nephrectomy: The SGPGI experience

    Directory of Open Access Journals (Sweden)

    Nand Kishore Arvind

    2002-01-01

    Full Text Available Background: Graft nephrectomy is often considered a hazardous procedure with high morbidity and occasional mortality, and this may pose a technical challenge. The aim of this study was to evaluate the indications, etiology and complications following graft nephrectomy. Materials and Methods: From 1988 to 2001, among total of 1,019 live related renal transplants carried at our center, 46 underwent graft nephrectomy. Patients were divided into 2 groups depending on timing of graft re-moval. The early group included 27 patients (within 2 months of transplantation while in late group (graft re-moval after 2 months of transplantation there were 19 patients. The 2 groups were compared in terms of indica-tion, etiology and complications. Results: In early group the indications for graft removal were acute rejection, thrombosis/infarction and hyper-acute rejection, while in late group the indications were pain, hematuria, fever, hypertension and infection along with chronic failure. Overall, the external iliac artery in-jury occurred in I and 4 patients in early and late group respectively. Major blood loss occurred in I and 6 pa-tients in early and late graft removal respectively. There were 2 deaths in early group due to ftdminant pneumoni-tis that progressed to sepsis and disseminated intravascu-lar coagulation. There were 9 major wound infections all in early group except in 2 patients of late group. Respira-tory infections occurred in 14 patients in early group and 1 in late group. In early group patients had CNS compli-cations in form of seizures, clinical depression and delusional psychosis in 12 patients. Conclusions: Our experience highlights the risk in-volved in graft nephrectomies. Severe acute rejection and thrombosis lead to early graft nephrectomies. Pain, hematuria, infection and hypertension in setting of chronic rejection are predominant causes for the delayed graft ne- phrectomies. Early graft nephrectomy, though technically easy, is

  13. Graft union formation in Douglas-fir.

    Science.gov (United States)

    D.L. Copes

    1969-01-01

    Greenhouse-grown Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) graft unions were examined between 2 and 84 days after grafting. Room temperature was maintained at 60-70 F throughout the growing season. In most respects grafts of Douglas-fir followed development patterns previously reported for spruce and pine grafts, but specific differences...

  14. Saphenous vein graft vs. radial artery graft searching for the best second coronary artery bypass graft

    Science.gov (United States)

    Al-Sabti, Hilal Ali; Al Kindi, Adil; Al-Rasadi, Khalid; Banerjee, Yajnavalka; Al-Hashmi, Khamis; Al-Hinai, Ali

    2013-01-01

    Coronary artery bypass grafting (CABG) was first used in the late 1960s. This revolutionary procedure created hope among ischemic heart disease patients. Multiple conduits are used and the golden standard is the left internal mammary artery to the left anterior descending artery. Although all approaches were advocated by doctors, the use of saphenous vein grafts became the leading approach used by the majority of cardiac surgeons in the 1970s. The radial artery graft was introduced at the same time but was not as prevalent due to complications. It was reintroduced into clinical practice in 1989. The procedure was not well received initially but it has since shown superiority in patency as well as long-term survival after CABG. This review provides a summary of characteristics, technical features and patency rates of the radial artery graft in comparison with venous conduits. Current studies and research into radial artery grafts and saphenous vein grafts for CABG are explored. However, more studies are required to verify the various findings of the positive effects of coronary artery bypass grafting with the help of radial arteries on mortality and long-lasting patency. PMID:24198449

  15. [Skin defect coverage with micro skin graft].

    Science.gov (United States)

    Gümüş, Nazim; Kaya, Yalçin; Karakaya, Sadik; Camci, Cemalettin

    2002-04-01

    The aim of this study is to coverage of the large skin defect with microskin graft. The wound coverage of the large skin defect may be difficult with auto skin graft. In these patients, split thickness skin graft may be used in a bloc shape or expanded skin graft shape and a stamp skin graft shape or expanded stamp skin graft shape. On the other hand, split thickness skin graft may be used as a micrograft shape after the mincing process, which reduces of the graft size in a few millimeters. In this study, 6 patients with skin defect was admitted in our clinic, and their skin defect was treated with micro skin graft. Expansion ratio was 1:15. Epithelialization on the wound surface was completed in 4 to 6 weeks and cobblestone appearance was observed after the wound coverage. Skin defect coverage with micrograft is an effective technique like the other skin graft coverage methods.

  16. The phenolic content and its involvement in the graft incompatibility process of various pear rootstocks (Pyrus communis L.).

    Science.gov (United States)

    Hudina, Metka; Orazem, Primoz; Jakopic, Jerneja; Stampar, Franci

    2014-03-01

    This study investigates the influence of various rootstocks for pear on the phytochemical composition in the phloem above and below the graft union and the role of phenols in pear graft incompatibility. Assays of phloem with cambium from 4-year-old 'Conference', 'Abate Fetel' and 'Williams' pear trees grafted on different rootstocks: Quince MA, Quince BA 29, Fox 11, Farold 40 (Daygon), seedling Pyrus communis L. and own rooted (P. communis L.) were analyzed with HPLC-MS. The most abundant phenolic compound in phloem above and below the graft union was arbutin, followed by procyanidin B1 and chlorogenic acid. In 'Conference' and 'Abate Fetel', higher arbutin content levels were measured above the graft union, while in the incompatible scion of 'Williams' on quince MA higher arbutin content levels were measured below the graft union. In all three observed cultivars (in 'Conference' the difference was not significant) grafted on Fox 11 rootstock, the highest content of arbutin was measured below the graft union. The results indicate that not only catechin and procyanidin B1, but also arbutin and several flavonols could be involved in graft incompatibility. All cultivars grafted on quince rootstocks had higher levels of epicatechin and procyanidin B2 below the graft union, even though some differences were not significant. It seems that those phenols do not affect pear incompatibility. A severe incompatibility between Fox 11 rootstock and 'Williams' was detected. Copyright © 2013 Elsevier GmbH. All rights reserved.

  17. Selective adsorption of cationic dyes from aqueous solution by polyoxometalate-based metal–organic framework composite

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xiaoxia; Gong, Wenpeng; Luo, Jing; Zou, Chentao; Yang, Yun; Yang, Shuijin, E-mail: yangshuijin@163.com

    2016-01-30

    Graphical abstract: Selective adsorption ability of H{sub 6}P{sub 2}W{sub 18}O{sub 62}/MOF-5 toward MO (a), Rhb (b) and the removal rate of Rhb, MO and MB (c). - Highlights: • Using metal–organic framework (MOF) composite as an adsorbent was investigated. • Selective adsorption ability of the composite towards cationic dyes was proposed. • The removal rate of MOF was raised greatly by the modification of polyoxometalate. • The adsorption kinetic and isotherm were used to describe the adsorption process. • The thermodynamic parameters of the composite were investigated in detail. - Abstract: A novel environmental friendly adsorbent H{sub 6}P{sub 2}W{sub 18}O{sub 62}/MOF-5 was synthesized by a simple one-step reaction under solvothermal conditions and characterized by XRD, FTIR, thermogravimetric analyses (TGA) and N{sub 2} adsorption–desorption isotherms. The removal rate of H{sub 6}P{sub 2}W{sub 18}O{sub 62}/MOF-5 was quite greater (85%) than that of MOF-5 (almost zero), showing that the adsorption performance of porous MOF-5 can be improved through the modification of H{sub 6}P{sub 2}W{sub 18}O{sub 62}. Further study revealed that H{sub 6}P{sub 2}W{sub 18}O{sub 62}/MOF-5 exhibited a fast adsorption rate and selective adsorption ability towards the cationic dyes in aqueous solution. The removal rate was up to 97% for cationic dyes methylene blue (MB) and 68% for rhodamine B(Rhb) within 10 min. However, anionicdye methyl orange(MO) can only reach to 10%. The influences including initial concentration, contact time, initial solution pH and temperature of MB adsorption onto H{sub 6}P{sub 2}W{sub 18}O{sub 62}/MOF-5 were investigated in detail. The kinetic study indicated that the adsorption of MB onto H{sub 6}P{sub 2}W{sub 18}O{sub 62}/MOF-5 followed the pseudo second-order model well. The isotherm obtained from experimental data fitted the Langmuir model, yielding maximum adsorption capacity of 51.81 mg/g. The thermodynamic parameters analysis

  18. Use and preservation methods of bone grafts in small animals

    Directory of Open Access Journals (Sweden)

    Rafael Garabet Agopian

    2016-09-01

    Full Text Available http://dx.doi.org/10.5007/2175-7925.2016v29n3p11 The present review describes the main characteristics of bone grafts used in small animals. Bone grafts are tissues without vasculature, which facilitate the production of new bone cells with osteogenic and osteoinductive factors that lead to the differentiation of cells and structural support for bone marrow. The transplant of a graft is followed by three stages: osteogenesis, or the formation of new bone; osteoinduction, which is the differentiation of cells; and osteoconduction, the process of growth of mesenchymal cells and capillaries that results in new bone formation. The composition of bone grafts may include spongy bone, cortical bone, cortical-spongy bone, cartilage or bone marrow. Grafts can also be classified according to their origin, being autogenous tissue when they are transplanted from the same individual, allogenous (homologous when originating from another individual of the same species, and xenogenous when obtained from a different species.

  19. Study on superhydrophobic surfaces of octanol grafted electrospun silica nanofibers

    International Nuclear Information System (INIS)

    Meng, Long-Yue; Han, Shunyu; Jiang, Nanzhe; Meng, Wan

    2014-01-01

    In this work, superhydrophobic surfaces were successfully prepared by grafting of octanol on the surface of electrospun silica nanofibers (SNFs). The chemical compositions and microstructures of the prepared SNFs surfaces were investigated by using N 2 full isotherms, Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and contact angle measurements. The results indicate that the surface of SNFs changed from being superhydrophilic to superhydrophobic by octanol surface grafting. The contact angle of the octanol-grafted SNFs was close to 150.2° because their surface was modified by –(CH 2 ) 6 –CH 3 groups. The 3D network of SNFs networks and the low surface energy of the alkyl side chains played important roles in creating the superhydrophobic surface of the SNFs. - Highlights: • Superhydrophobic surface was prepared from electrospinning SNFs and by grafting octanol on their surface. • The surface of SNFs changed from superhydrophilic to superhydrophobic. • The CA of MSNFs became 150.2° because of interactions between grafted octyl groups

  20. Study on superhydrophobic surfaces of octanol grafted electrospun silica nanofibers

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Long-Yue [Key Laboratory of Natural Resources of Changbai Mountain and Functional Molecules, Yanbian University, Yanji 133002 (China); Department of Chemical Engineering, College of Engineering, Yanbian University, 977 Gongyuan Road, Yanji 133002 (China); Han, Shunyu; Jiang, Nanzhe [Department of Chemical Engineering, College of Engineering, Yanbian University, 977 Gongyuan Road, Yanji 133002 (China); Meng, Wan, E-mail: mengw@ybu.edu.cn [Department of Chemical Engineering, College of Engineering, Yanbian University, 977 Gongyuan Road, Yanji 133002 (China)

    2014-12-15

    In this work, superhydrophobic surfaces were successfully prepared by grafting of octanol on the surface of electrospun silica nanofibers (SNFs). The chemical compositions and microstructures of the prepared SNFs surfaces were investigated by using N{sub 2} full isotherms, Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and contact angle measurements. The results indicate that the surface of SNFs changed from being superhydrophilic to superhydrophobic by octanol surface grafting. The contact angle of the octanol-grafted SNFs was close to 150.2° because their surface was modified by –(CH{sub 2}){sub 6}–CH{sub 3} groups. The 3D network of SNFs networks and the low surface energy of the alkyl side chains played important roles in creating the superhydrophobic surface of the SNFs. - Highlights: • Superhydrophobic surface was prepared from electrospinning SNFs and by grafting octanol on their surface. • The surface of SNFs changed from superhydrophilic to superhydrophobic. • The CA of MSNFs became 150.2° because of interactions between grafted octyl groups.

  1. Synthesis and characterization of polypyrrole grafted chitin

    Science.gov (United States)

    Ramaprasad, A. T.; Latha, D.; Rao, Vijayalakshmi

    2017-05-01

    Synthesis and characterization of chitin grafted with polypyrrole (PPy) is reported in this paper. Chitin is soaked in pyrrole solution of various concentrations for different time intervals and polymerized using ammonium peroxy disulphate (APS) as an initiator. Grafting percentage of polypyrrole onto chitin is calculated from weight of chitin before and after grafting. Grafting of polymer is further verified by dissolution studies. The grafted polymer samples are characterized by FTIR, UV-Vis absorption spectrum, XRD, DSC, TGA, AFM, SEM and conductivity studies.

  2. Validity of Selected Bioimpedance Equations for Estimating Body Composition in Men and Women: A Four-Compartment Model Comparison.

    Science.gov (United States)

    Nickerson, Brett S; Esco, Michael R; Bishop, Phillip A; Schumacker, Randall E; Richardson, Mark T; Fedewa, Michael V; Wingo, Jonathan E; Welborn, Bailey A

    2017-07-01

    Nickerson, BS, Esco, MR, Bishop, PA, Schumacker, RE, Richardson, MT, Fedewa, MV, Wingo, JE, and Welborn, BA. Validity of selected bioimpedance equations for estimating body composition in men and women: a four-compartment model comparison. J Strength Cond Res 31(7): 1963-1972, 2017-The purpose of this study was to compare body fat percentage (BF%) and fat-free mass (FFM) values from bioelectrical impedance analysis (BIA) equations to values determined from a 4-compartment (4C) model. Eighty-two adults (42 men and 40 women) volunteered to participate (age = 23 ± 5 years). Body fat percentage and FFM were estimated from previously developed BIA equations by Chumlea et al. (BIACH), Deurenberg et al. (BIADE), Kyle et al. (BIAKYLE), and Sun et al. (BIASUN). Four-compartment model body composition was derived from underwater weighing for body density, dual-energy X-ray absorptiometry for bone mineral content, and bioimpedance spectroscopy for total body water. The standard error of estimate (SEE) for group BF% and FFM ranged from 3.0 to 3.8% and 2.1 to 2.7 kg, respectively. The constant error (CE) was significantly higher and lower for BF% and FFM (p equations (BIACH, CE = 3.1% and -2.2 kg; BIADE, CE = 3.7% and -2.9 kg; BIAKYLE, CE = 2.3% and -1.9 kg), but was not significant for BF% (p = 0.702) and FFM (p = 0.677) for BIASUN (CE = -0.1% and 0.1 kg). The 95% limits of agreement were narrowest for BIACH (±5.9%; ±4.2 kg) and largest for BIADE (±7.4%; ±6.2 kg). The significant CE yielded by BIACH, BIADE, and BIAKYLE indicates these equations tend to overpredict group BF% and underestimate group FFM. However, all BIA equations produced low SEEs and fairly narrow limits of agreement. When the use of a 4C model is not available, practitioners might consider using one of the selected BIA equations, but should consider the associated CE.

  3. Surface characterization and biological properties study of silicone rubber membrane grafted with phospholipid as biomaterial via plasma induced graft copolymerization.

    Science.gov (United States)

    Hsiue, G H; Lee, S D; Chang, P C; Kao, C Y

    1998-10-01

    Poly(2-methacryloyloxyethyl phosphorylcholine) (pMPC) was grafted onto the surface of a silicon rubber (SR) membrane (pMPC-SR) by plasma induced grafted copolymerization (PIP). Argon plasma was used to activate the SR surfaces. Determination was also made of the influences of grafted copolymerization reaction time, reaction temperature, and monomer concentration on polymerization yield. The surface properties of SR were characterized by ATR-FTIR, ESCA, and SEM. In those analyses the ATR-FTIR spectra indicated that the pMPC grafted onto the SR surface at 1720 and 3300 cm(-1). The elemental composition and different carbon bindings on the surface of the SR were examined by ESCA. An increasing P1s/C1s value g was obtained in the grafted polymerization yield with a concentration of 0.05-0.5M of MPC in the isolated ethanol solution. The surface morphologies of pMPC-SR differed more than those of control and Ar plasma treated surfaces. The difference could have been caused by the homogeneous graft polymerization of pMPC onto the SR membrane. In the biological analyses, protein adsorption on pMPC-SR surfaces was reduced. The reduced level increased with an increase in the pMPC grafted amount. The epithelial cell attachment and growth onto these samples were suppressed. The blood compatibility for a series of pMPC-SR surfaces was examined by platelet adhesion. Blood platelet morphologies in contact with the high ratio of pMPC-SR surfaces were maintained, meaning that in this case the release reaction for platelets never occurred. Consequently, the high amount of pMPC-SR surface had excellent blood compatibility, further suggesting that prevention of adhesion, activation of platelets, and adsorption of blood protein could be achieved.

  4. Preparation of poly(ether ether ketone)-based polymer electrolytes for fuel cell membranes using grafting technique

    International Nuclear Information System (INIS)

    Hasegawa, Shin; Suzuki, Yasuyuki; Maekawa, Yasunari

    2008-01-01

    Poly(ether ether ketone) (PEEK)-based polymer electrolyte membranes (PEMs) was successfully prepared by radiation grafting of a styrene monomer into PEEK films and the consequent selective sulfonation of the grafting chains in the film state. Using milder sulfonation, the sulfonation reactions proceeded at the grafted chains in preference to the phenylene rings of PEEK main chains; as a result, the grafted films could successfully transform to a PEM with conductivity of more than 0.1 S/cm. The ion exchange capacity (IEC) and conductivity of the grafted PEEK electrolyte membranes were controlled to the ranges of 1.2-2.9 mmol/g and 0.03-0.18 S/cm by changing the grafting degree. It should be noted that this is the first example of directly transforming super-engineering plastic films into a PEM using radiation grafting

  5. Bone Grafting: Sourcing, Timing, Strategies, and Alternatives.

    Science.gov (United States)

    Egol, Kenneth A; Nauth, Aaron; Lee, Mark; Pape, Hans-Christoph; Watson, J Tracy; Borrelli, Joseph

    2015-12-01

    Acute fractures, nonunions, and nonunions with bone defects or osteomyelitis often need bone graft to facilitate union. There are several factors to consider when it is determined that a bone graft is needed. These factors include the source of the bone graft (autograft vs. allograft), proper timing for placement of the bone graft, strategies to avoid further complications (particularly in the setting of osteomyelitis), and with the development of a variety of bone graft substitutes, whether alternatives to autograft are available and appropriate for the task at hand. Autograft bone has commonly been referred to as the "gold standard" of bone grafts, against which the efficacy of other grafts has been measured. The best timing for when to place a bone graft or substitute is also somewhat controversial, particularly after an open fracture or a potentially contaminated bed. The treatment of infected nonunions, particularly those that require a graft to facilitate healing, can be quite challenging. Typically, the infection is completely eradicated before placement of a bone graft, but achieving a sterile bed and the timing of a bone graft require strategic thinking and planning. This review outlines the benefits of autografts, the most suitable sites for harvesting bone grafts, the timing of bone graft procedures, the potential risks and benefits of grafting in the face of infection, and the currently available bone graft extenders.

  6. Air Pump-Assisted Graft Centration, Graft Edge Unfolding, and Graft Uncreasing in Young Donor Graft Pre-Descemet Endothelial Keratoplasty.

    Science.gov (United States)

    Jacob, Soosan; Narasimhan, Smita; Agarwal, Amar; Agarwal, Athiya; A I, Saijimol

    2017-08-01

    To assess an air pump-assisted technique for graft centration, graft edge unfolding, and graft uncreasing while performing pre-Descemet endothelial keratoplasty (PDEK) using young donor grafts. Continuous pressurized air infusion was used for graft centration, graft edge unfolding, and graft unwrinkling. Ten eyes of 10 patients underwent PDEK with donors aged below 40 years. In all eyes, the donor scrolled into tight scrolls. In all cases, the air pump-assisted technique was effective in positioning and centering the graft accurately and in straightening infolded graft edges and smoothing out graft creases and wrinkles. Endothelial cell loss was 38.6%. Postoperative best-corrected visual acuity at 6 months was 0.66 ± 0.25 in decimal equivalent. Continuous pressurized air infusion acted as a third hand providing a continuous pressure head that supported the graft and prevented graft dislocation as well as anterior chamber collapse during intraocular maneuvering. Adequate maneuvering space was available in all cases, and bleeding, if any, was tamponaded successfully in all cases. Although very young donor grafts may be used for PDEK, they are difficult to center and unroll completely before floating against host stroma. An air pump-assisted technique using continuous pressurized air infusion allows successful final graft positioning even with very young donor corneas. It thus makes surgery easier as several key steps are made easier to handle. It additionally helps in tamponading hemorrhage during peripheral iridectomy, increasing surgical space, preventing fluctuations in the anterior chamber depth, and promoting graft adherence.

  7. Revascularização miocárdica com enxerto composto de artéria torácica interna esquerda em Y: análise de fluxo sangüíneo Myocardial revascularization surgery using composite Y-graft of the left internal thoracic artery: blood flow analysis

    Directory of Open Access Journals (Sweden)

    José Glauco Lobo Filho

    2004-03-01

    the LADA and another artery from the LCAS. The angiographic study showed graft patency in all patients from both groups. The following parameters were used: systolic flow (SF, diastolic flow, total flow, total flow in stress/total flow at rest ratio (TFS/TFR, systolic peak velocities (SPV, diastolic peak velocities and systolic peak velocity/diastolic peak velocity ratio. RESULTS: All analysed parameters were considered statistically significant, except SF, TFS/TFR and SPV. CONCLUSIONS: We concluded that in the same conditions and methodology, the LITA flow in the composite graft (group B is higher than in the free graft (group A, which shows the great flow adaptability of LITA to respond to flow demand.

  8. Primary graft dysfunction.

    Science.gov (United States)

    Suzuki, Yoshikazu; Cantu, Edward; Christie, Jason D

    2013-06-01

    Primary graft dysfunction (PGD) is a syndrome encompassing a spectrum of mild to severe lung injury that occurs within the first 72 hours after lung transplantation. PGD is characterized by pulmonary edema with diffuse alveolar damage that manifests clinically as progressive hypoxemia with radiographic pulmonary infiltrates. In recent years, new knowledge has been generated on risks and mechanisms of PGD. Following ischemia and reperfusion, inflammatory and immunological injury-repair responses appear to be key controlling mechanisms. In addition, PGD has a significant impact on short- and long-term outcomes; therefore, the choice of donor organ is impacted by this potential adverse consequence. Improved methods of reducing PGD risk and efforts to safely expand the pool are being developed. Ex vivo lung perfusion is a strategy that may improve risk assessment and become a promising platform to implement treatment interventions to prevent PGD. This review details recent updates in the epidemiology, pathophysiology, molecular and genetic biomarkers, and state-of-the-art technical developments affecting PGD. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  9. Preparation of poly(methyl methacrylate) grafted hydroxyapatite nanoparticles via reverse ATRP.

    Science.gov (United States)

    Wang, Yan; Xiao, Yan; Huang, Xiujuan; Lang, Meidong

    2011-08-15

    Surface-initiated reverse atom transfer radical polymerization (reverse ATRP) technical was successfully employed to modify hydroxyapatite (HAP) nanoparticles with poly(methyl methacrylate) (PMMA). The peroxide initiator moiety for reverse ATRP was covalently attached to the HAP surface through the surface hydroxyl groups. Reverse ATRP of methyl methacrylate (MMA) from the initiator-functionalized HAP was carried out, and the end bromide groups of grafted PMMA initiated ATRP of MMA subsequently. Fourier transformation infrared (FTIR) spectroscopy, thermal gravimetric analysis (TGA) and transmission electron microscopy (TEM) were employed to confirm the grafting and to characterize the nanoparticle structure. The grafted PMMA gave HAP nanoparticles excellent dispersibility in MMA monomer. As the amount of grafted PMMA increased, the dispersibility of surface-grafted HAP and the compressive strength of HAP/PMMA composites were improved. Copyright © 2011 Elsevier Inc. All rights reserved.

  10. The effects of selection indices for sustainable hill sheep production on carcass composition and muscularity of lambs, measured using X-ray computed tomography.

    Science.gov (United States)

    Lambe, N R; Bünger, L; Bishop, S C; Simm, G; Conington, J

    2008-01-01

    A multi-trait selection index designed to improve the overall economic performance of hill sheep, including both maternal and lamb traits, has been developed and tested in a selection experiment over 7 years. Two versions of the index were tested, with different economic weights applied to the traits, on two different hill farms: one version including maternal and growth traits; the other version with additional breeding goals of carcass weight, fatness and conformation scores. Responses to selection, using both versions of the index, suggest that improvements are being made in overall index score and lamb growth. This study investigated the indirect effects of these selection indices on lamb carcass composition and muscularity traits, as measured using X-ray computed tomography (CT) scanning. A total of 499 lambs from the two hill farms were CT scanned at weaning (approximately 120 days of age). Approximately half of the lambs from each farm were from the selection line (S, animals with highest index scores selected for breeding), while the other half were from a control line (C, animals with average index scores selected). Composition and muscularity traits were estimated on each lamb from CT data and differences between genetic lines investigated, within farm, using restricted maximum likelihood analyses, adjusting for either live weight or age. Results showed that the selection index without carcass traits produced lambs with carcass composition that was not significantly different to control lambs at a given live weight or age. Including carcass traits in the index resulted in lambs with no compositional differences (except for a slight increase in bone) at a set age compared with controls. At a given live weight however, selection lambs had less fat and lower carcass weights and killing-out percentage. Muscularity (3-D muscle shape) and muscle area shape (2-D) were not improved as a result of selection on either version of the index (including carcass weight

  11. Characterization of microbiota composition and presence of selected antibiotic resistance genes in carriage water of ornamental fish.

    Science.gov (United States)

    Gerzova, Lenka; Videnska, Petra; Faldynova, Marcela; Sedlar, Karel; Provaznik, Ivo; Cizek, Alois; Rychlik, Ivan

    2014-01-01

    International trade with ornamental fish is gradually recognized as an important source of a wide range of different antibiotic resistant bacteria. In this study we therefore characterized the prevalence of selected antibiotic resistance genes in the microbiota found in the carriage water of ornamental fish originating from 3 different continents. Real-time PCR quantification showed that the sul1 gene was present in 11 out of 100 bacteria. tet(A) was present in 6 out of 100 bacteria and strA, tet(G), sul2 and aadA were present in 1-2 copies per 100 bacteria. Class I integrons were quite common in carriage water microbiota, however, pyrosequencing showed that only 12 different antibiotic gene cassettes were present in class I integrons. The microbiota characterized by pyrosequencing of the V3/V4 variable region of 16S rRNA genes consisted of Proteobacteria (48%), Bacteroidetes (29.5%), Firmicutes (17.8%), Actinobacteria (2.1%) and Fusobacteria (1.6%). Correlation analysis between antibiotic resistance gene prevalence and microbiota composition verified by bacterial culture showed that major reservoirs of sul1 sul2, tet(A), tet(B) tet(G), cat, cml, bla, strA, aacA, aph and aadA could be found among Alpha-, Beta- and Gammaproteobacteria with representatives of Enterobacteriaceae, Pseudomonadaceae, Rhizobiaceae and Comamonadaceae being those most positively associated with the tested antibiotic resistance genes.

  12. Morphological and Compositional Design of Pd-Cu Bimetallic Nanocatalysts with Controllable Product Selectivity toward CO2 Electroreduction.

    Science.gov (United States)

    Zhu, Wenjin; Zhang, Lei; Yang, Piaoping; Chang, Xiaoxia; Dong, Hao; Li, Ang; Hu, Congling; Huang, Zhiqi; Zhao, Zhi-Jian; Gong, Jinlong

    2018-02-01

    Electrochemical conversion of carbon dioxide (electrochemical reduction of carbon dioxide) to value-added products is a promising way to solve CO 2 emission problems. This paper describes a facile one-pot approach to synthesize palladium-copper (Pd-Cu) bimetallic catalysts with different structures. Highly efficient performance and tunable product distributions are achieved due to a coordinative function of both enriched low-coordinated sites and composition effects. The concave rhombic dodecahedral Cu 3 Pd (CRD-Cu 3 Pd) decreases the onset potential for methane (CH 4 ) by 200 mV and shows a sevenfold CH 4 current density at -1.2 V (vs reversible hydrogen electrode) compared to Cu foil. The flower-like Pd 3 Cu (FL-Pd 3 Cu) exhibits high faradaic efficiency toward CO in a wide potential range from -0.7 to -1.3 V, and reaches a fourfold CO current density at -1.3 V compared to commercial Pd black. Tafel plots and density functional theory calculations suggest that both the introduction of high-index facets and alloying contribute to the enhanced CH 4 current of CRD-Cu 3 Pd, while the alloy effect is responsible for high CO selectivity of FL-Pd 3 Cu. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Site-Selective Modification of Cellulose Nanocrystals with Isophorone Diisocyanate and Formation of Polyurethane-CNC Composites.

    Science.gov (United States)

    Girouard, Natalie M; Xu, Shanhong; Schueneman, Gregory T; Shofner, Meisha L; Meredith, J Carson

    2016-01-20

    The unequal reactivity of the two isocyanate groups in an isophorone diisocyante (IPDI) monomer was exploited to yield modified cellulose nanocrystals (CNCs) with both urethane and isocyanate functionality. The chemical functionality of the modified CNCs was verified with ATR-FTIR analysis and elemental analysis. The selectivity for the secondary isocyanate group using dibutyl tin dilaurate (DBTDL) as the reaction catalyst was confirmed with (13)C NMR. The modified CNCs showed improvements in the onset of thermal degradation by 35 °C compared to the unmodified CNCs. Polyurethane composites based on IPDI and a trifunctional polyether alcohol were synthesized using unmodified (um-CNC) and modified CNCs (m-CNC). The degree of nanoparticle dispersion was qualitatively assessed with polarized optical microscopy. It was found that the modification step facilitated superior nanoparticle dispersion compared to the um-CNCs, which resulted in increases in the tensile strength and work of fracture of over 200% compared to the neat matrix without degradation of elongation at break.

  14. Proximate composition and selected physicochemical properties of the seed, pulp and oil of sour sop (Annona muricata).

    Science.gov (United States)

    Onimawo, I A

    2002-01-01

    Proximate composition and physicochemical analyses were carried out on the seed, pulp and extracted oil of sour sop (Annona muricata). The results showed that the seed contained 8.5% moisture, 2.4% crude protein, 13.6% ash, 8.0% crude fiber, 20.5% fat and 47.0% carbohydrate. The seed also contained 0.2% water soluble ash, 0.79% titratable acidity and 17.0 mg calcium/100 g. The pulp was found to contain 81% moisture, 3.43% titratable acidity and 24.5% non-reducing sugar. Selected physicochemical characteristics included refractive indices of 1.335 for the seed and 1.356 for the pulp, specific gravities of 1.250 for the seed and 1.023 for the pulp, pH values of 8.34 for the seed and 4.56 for the pulp, and soluble solids contents of 1.5 degrees Brix for the seed and 15 degrees Brix for the pulp. The extracted oil (20.5% yield) had a 60.43% unsaponifiable value, 23.54 KOH/g acid value, 100.98 KOH/g saponification value, 1.1 KOH/g peroxide value, 1.464 refractive index, 5.77 pH, 69.5 degrees Brix sosluble solids and 0.2900 specific gravity.

  15. Design and fabrication of inner-selective thin-film composite (TFC) hollow fiber modules for pressure retarded osmosis (PRO)

    KAUST Repository

    Wan, Chun Feng

    2016-08-03

    Pressure retarded osmosis (PRO) is a promising technology to harvest the renewable osmotic energy from salinity gradients. There are great progresses in the fabrication of PRO membranes in the last decade. Thin-film composite (TFC) hollow fibers have been widely studied and demonstrated superior performance. However, the lack of effective TFC hollow fiber modules hinders the commercialization of the PRO technology. Knowledge and experiences to fabricate TFC hollow fiber modules remain limited in the open literature. In this study, we aim to reveal the engineering and science on how to fabricate TFC hollow fiber modules including the formation of inner-selective polyamide layers and the repair of leakages. TFC-PES hollow fiber modules with 30% and 50% packing densities have been successfully fabricated, showing peak power densities of 20.0 W/m2 and 19.4 W/m2, respectively, at 20 bar using 1 M NaCl solution and DI water as feeds. The modules may be damaged during handling and high pressure testing. The repaired modules have a power density of 18.2 W/m2, 91% of the power densities of the undamaged ones. This study would make up the gap between TFC membrane fabrication and TFC membrane module fabrication in the membrane industry. © 2016 Elsevier B.V.

  16. A Compact Via-free Composite Right/Left Handed Low-pass Filter with Improved Selectivity

    Science.gov (United States)

    Kumar, Ashish; Choudhary, Dilip Kumar; Chaudhary, Raghvendra Kumar

    2017-07-01

    In this paper, a compact via-free low pass filter is designed based on composite right/left handed (CRLH) concept. The structure uses open ended concept. Rectangular slots are etched on signal transmission line (TL) to suppress the spurious band without altering the performance and size of filter. The filter is designed for low pass frequency band with cut-off frequency of 3.5 GHz. The proposed metamaterial structure has several prominent advantages in term of selectivity up to 34 dB/GHz and compactness with average insertion loss less than 0.4 dB. It has multiple applications in wireless communication (such as GSM900, global navigation satellite system (1.559-1.610 GHz), GSM1800, WLAN/WiFi (2.4-2.49 GHz) and WiMAX (2.5-2.69 GHz)). The design parameters have been measured and compared with the simulated results and found excellent agreement. The electrical size of proposed filter is 0.14λ0× 0.11λ0 (where λ0 is free space wavelength at zeroth order resonance (ZOR) frequency 2.7 GHz).

  17. Glass and Glass-Ceramic Materials from Simulated Composition of Lunar and Martian Soils: Selected Properties and Potential Applications

    Science.gov (United States)

    Ray, C. S.; Sen, S.; Reis, S. T.; Kim, C. W.

    2005-01-01

    In-situ resource processing and utilization on planetary bodies is an important and integral part of NASA's space exploration program. Within this scope and context, our general effort is primarily aimed at developing glass and glass-ceramic type materials using lunar and martian soils, and exploring various applications of these materials for planetary surface operations. Our preliminary work to date have demonstrated that glasses can be successfully prepared from melts of the simulated composition of both lunar and martian soils, and the melts have a viscosity-temperature window appropriate for drawing continuous glass fibers. The glasses are shown to have the potential for immobilizing certain types of nuclear wastes without deteriorating their chemical durability and thermal stability. This has a direct impact on successfully and economically disposing nuclear waste generated from a nuclear power plant on a planetary surface. In addition, these materials display characteristics that can be manipulated using appropriate processing protocols to develop glassy or glass-ceramic magnets. Also discussed in this presentation are other potential applications along with a few selected thermal, chemical, and structural properties as evaluated up to this time for these materials.

  18. Preparation and Grafting Functionalization of Self-Assembled Chitin Nanofiber Film

    Directory of Open Access Journals (Sweden)

    Jun-ichi Kadokawa

    2016-07-01