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Sample records for repeat glycerol rhizotomies

  1. Percutaneous Glycerol Rhizotomy for Trigeminal Neuralgia Using a Single-Plane, Flat Panel Detector Angiography System: Technical Note

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    ARISHIMA, Hidetaka; KAWAJIRI, Satoshi; ARAI, Hiroshi; HIGASHINO, Yoshifumi; KODERA, Toshiaki; KIKUTA, Ken-ichiro

    2016-01-01

    Percutaneous treatments for trigeminal neuralgia (TN) including glycerol rhizotomy (GR), radiofrequency thermocoagulation (RT), and balloon compression (BC) are effective for patients with medical comorbidities and risk factors of microvascular decompression (MVD). These procedures are usually performed under fluoroscopy. Surgeons advance the needle to the trigeminal plexus through the foramen ovale while observing landmarks of fluoroscopic images; however, it is sometimes difficult to appropriately place the needle tip in Meckel’s cave. We present the technical details of percutaneous GR using a single-plane, flat panel detector angiography system to check the needle positioning. When the needle tip may be located near the trigeminal cistern, three-dimensional (3-D) bone images are taken with cone-beam computed tomography (CT). These images clearly show the position of the needle tip in Meckel’s cave. If it is difficult to place it through the foramen ovale, surgeons perform cone beam CT to observe the actual position of the needle tip at the skull base. After confirming the positional relation between the needle tip and foramen ovale, surgeons can advance it in the precise direction. In 10 procedures, we could place the nerve-block needle in about 14.5 minutes on average without complications. We think that our method is simple and convenient for percutaneous treatments for TN, and it may be helpful for surgeons to perform such treatments. PMID:27041633

  2. Percutaneous Glycerol Rhizotomy for Trigeminal Neuralgia Using a Single-Plane, Flat Panel Detector Angiography System: Technical Note.

    Science.gov (United States)

    Arishima, Hidetaka; Kawajiri, Satoshi; Arai, Hiroshi; Higashino, Yoshifumi; Kodera, Toshiaki; Kikuta, Ken-Ichiro

    2016-05-15

    Percutaneous treatments for trigeminal neuralgia (TN) including glycerol rhizotomy (GR), radiofrequency thermocoagulation (RT), and balloon compression (BC) are effective for patients with medical comorbidities and risk factors of microvascular decompression (MVD). These procedures are usually performed under fluoroscopy. Surgeons advance the needle to the trigeminal plexus through the foramen ovale while observing landmarks of fluoroscopic images; however, it is sometimes difficult to appropriately place the needle tip in Meckel's cave. We present the technical details of percutaneous GR using a single-plane, flat panel detector angiography system to check the needle positioning. When the needle tip may be located near the trigeminal cistern, three-dimensional (3-D) bone images are taken with cone-beam computed tomography (CT). These images clearly show the position of the needle tip in Meckel's cave. If it is difficult to place it through the foramen ovale, surgeons perform cone beam CT to observe the actual position of the needle tip at the skull base. After confirming the positional relation between the needle tip and foramen ovale, surgeons can advance it in the precise direction. In 10 procedures, we could place the nerve-block needle in about 14.5 minutes on average without complications. We think that our method is simple and convenient for percutaneous treatments for TN, and it may be helpful for surgeons to perform such treatments.

  3. [Suprasegmental effects of selective posterior rhizotomy].

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    Horínek, D; Tichý, M; Cerný, R; Vlková, J

    2004-01-01

    The occurrence of spasticity is most commonly attributed to the lack of presynaptic inhibition. Perinatal damage to the central nervous system, as it happens in cerebral palsy, leads to pathological reflex response both on segmental and polysegmental levels. It results not only in clinical signs typical for spasticity but also in alterations of brainstem function, such as dysarthria or congenital nystagmus. Selective posterior rhizotomy is a neurosurgical method, routinely used in the treatment of spasticity. The lumbosacral posterior roots are partially cut under perioperative neurophysiological control. The aim of the treatment is the reduction of afferentation for posterior horns resulting in a decrease of pathological reflex responses. Selective posterior rhizotomy consequently decreases lower limbs spasticity. The improvement of upper extremities fine skills, the improvement of speech and cognitive functions has been also observed after selective posterior rhizotomy. The possible pathophysiological explanations of these so-called suprasegmental effects are discussed in the article.

  4. Selective posterior lumbosacral rhizotomy for the management ...

    African Journals Online (AJOL)

    and we now present a 10-year experience with a considerably larger ... 26 years. Eighty were male and 30 were female. ... had procedures both before and after rhizotomy. Results ... Four children had mild low back pain on direct ques- ... Sherringron'slO experimental dorsal ... The long-term observations (')f children with.

  5. Sedation with alfentanil and propofol for rhizotomies

    African Journals Online (AJOL)

    M Jansen van Rensburg

    alfentanil, in combination with a constant propofol infusion, for optimal pain control ... All of the patients experienced ventilatory depression, but a patent .... placements (observation points 3–11) for lumbar (L) rhizotomies ..... in the infusion, a total of 10 patients (nine females and one male), ... effects before propofol is added.

  6. SPINAL DEFORMITIES AFTER SELECTIVE DORSAL RHIZOTOMY

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    PATRICIO PABLO MANZONE

    Full Text Available ABSTRACT Objective: Selective dorsal rhizotomy (SDR used for spasticity treatment could worsen or develop spinal deformities. Our goal is to describe spinal deformities seen in patients with cerebral palsy (CP after being treated by SDR. Methods: Retrospective study of patients operated on (SDR between January/1999 and June/2012. Inclusion criteria: spinal Rx before SDR surgery, spinography, and assessment at follow-up. We evaluated several factors emphasizing level and type of SDR approach, spinal deformity and its treatment, final Risser, and follow-up duration. Results: We found 7 patients (6 males: mean age at SDR 7.56 years (4.08-11.16. Mean follow-up: 6.64 years (2.16-13, final age: 14.32 years (7.5-19. No patient had previous deformity. GMFCS: 2 patients level IV, 2 level III, 3 level II. Initial walking status: 2 community walkers, 2 household walkers, 2 functional walkers, 1 not ambulant, at the follow-up, 3 patients improved, and 4 kept their status. We found 4 TL/L laminotomies, 2 L/LS laminectomies, and 1 thoracic laminectomy. Six spinal deformities were observed: 2 sagittal, 3 mixed, and 1 scoliosis. There was no association among the type of deformity, final gait status, topographic type, GMFCS, age, or SDR approach. Three patients had surgery indication for spinal deformity at skeletal maturity, while those patients with smaller deformities were still immature (Risser 0 to 2/3 although with progressive curves. Conclusions: After SDR, patients should be periodically evaluated until they reach Risser 5. The development of a deformity does not compromise functional results but adds morbidity because it may require surgical treatment.

  7. Single-level selective dorsal rhizotomy for spastic cerebral palsy

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    Graham, David; Cawker, Stephanie; Paget, Simon; Wimalasundera, Neil

    2016-01-01

    The management of cerebral palsy (CP) is complex and requires a multidisciplinary approach. Selective dorsal rhizotomy (SDR) is a neurosurgical technique that aims to reduce spasticity in the lower limbs. A minimally invasive approach to SDR involves a single level laminectomy at the conus and utilises intraoperative electromyography (EMG). When combined with physiotherapy, SDR is effective in selected children and has minimal complications. This review discusses the epidemiology of CP and the management using SDR within an integrated multidisciplinary centre. Particular attention is given to the single-level laminectomy technique of SDR and its rationale, and the patient workup, recovery and outcomes of SDR. PMID:27757432

  8. Cervical selective dorsal rhizotomy for treating spasticity in upper limb neurosurgical way to neurosurgical technique

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    Yu Duan

    2015-03-01

    Full Text Available Selective dorsal rhizotomy is an effective method to reduce spasticity of the lower limbs. However, functional outcomes in the upper limb following selective dorsal rhizotomy at the cervical level have not been reported. Here we report the clinical course after selective dorsal rhizotomy at the cervical level in a patient with hemiplegic spasticity caused by brain injury. The selective dorsal rootlets at the cervical level were sectioned under electrophysiological monitoring. The patient was followed for 1 year to evaluate the outcome of surgery. The spasticity in the upper limb was reduced and the passive range of motion and function of movement improved. However, the effectiveness and the safety of operation should be studied further in clinical trials.

  9. Long-term outcomes five years after selective dorsal rhizotomy

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    Lagergren Jan

    2008-12-01

    Full Text Available Abstract Background Selective dorsal rhizotomy (SDR is a well accepted neurosurgical procedure performed for the relief of spasticity interfering with motor function in children with spastic cerebral palsy (CP. The goal is to improve function, but long-term outcome studies are rare. The aims of this study were to evaluate long-term functional outcomes, safety and side effects during five postoperative years in all children with diplegia undergoing SDR combined with physiotherapy. Methods This study group consisted of 35 children, consecutively operated, with spastic diplegia, of which 26 were Gross Motor Function Classification System (GMFCS levels III–V. Mean age was 4.5 years (range 2.5–6.6. They were all assessed by the same multidisciplinary team at pre- and at 6, 12, 18 months, 3 and 5 years postoperatively. Clinical and demographic data, complications and number of rootlets cut were prospectively registered. Deep tendon reflexes and muscle tone were examined, the latter graded with the modified Ashworth scale. Passive range of motion (PROM was measured with a goniometer. Motor function was classified according to the GMFCS and measured with the Gross Motor Function Measure (GMFM-88 and derived into GMFM-66. Parent's opinions about the children's performance of skills and activities and the amount of caregiver assistance were measured with Pediatric Evaluation Disability Inventory (PEDI. Results The mean proportion of rootlets cut in S2-L2 was 40%. Muscle tone was immediately reduced in adductors, hamstrings and dorsiflexors (p Conclusion SDR is a safe and effective method for reducing spasticity permanently without major negative side effects. In combination with physiotherapy, in a group of carefully selected and systematically followed young children with spastic diplegia, it provides lasting functional benefits over a period of at least five years postoperatively.

  10. Neurogenic bladder: Highly selective rhizotomy of specific dorsal rootlets maybe a better choice.

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    Zhu, Genying; Zhou, Mouwang; Wang, Wenting; Zeng, Fanshuo

    2016-02-01

    Spinal cord injury results not only in motor and sensory dysfunctions, but also in loss of normal urinary bladder functions. A number of clinical studies were focused on the strategies for improvement of functions of the bladder. Completely dorsal root rhizotomy or selective specific S2-4 dorsal root rhizotomy suppress autonomic hyper-reflexia but have the same defects: it could cause detrusor and sphincter over-relaxation and loss of reflexive erection in males. So precise operation needs to be considered. We designed an experimental trail to test the possibility on the basis of previous study. We found that different dorsal rootlets which conduct impulses from the detrusor or sphincter can be distinguished by electro-stimulation in SD rats. Highly selective rhizotomy of specific dorsal rootlets could change the intravesical pressure and urethral perfusion pressure respectively. We hypothese that for neurogenic bladder following spinal cord injury, highly selective rhizotomy of specific dorsal rootlets maybe improve the bladder capacity and the detrusor sphincter dyssynergia, and at the same time, the function of other pelvic organ could be maximize retainment.

  11. Lumbosacral Dorsal Rhizotomy for Spastic Cerebral Palsy: A Health Technology Assessment

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    Pron, Gaylene; Chan, Brian; Tu, Hong Anh; Xie, Xuanqian; Weir, Mark; Wells, David; Higgins, Caroline

    2017-01-01

    Background Cerebral palsy, a spectrum of neuromuscular conditions caused by abnormal brain development or early damage to the brain, is the most common cause of childhood physical disability. Lumbosacral dorsal rhizotomy is a neurosurgical procedure that permanently decreases spasticity and is always followed by physical therapy. The objectives of this health technology assessment were to evaluate the clinical effectiveness, safety, cost effectiveness, and family perspectives of dorsal rhizotomy. Methods We performed a systematic literature search until December 2015 with auto-alerts until December 2016. Search strategies were developed by medical librarians, and a single reviewer reviewed the abstracts. The health technology assessment included a clinical review based on functional outcomes, safety, and treatment satisfaction; an economic study reviewing cost-effective literature; a budget impact analysis; and interviews with families evaluating the intervention. Results Eighty-four studies (1 meta-analysis, 5 randomized controlled studies [RCTs], 75 observational pre-post studies, and 3 case reports) were reviewed. A meta-analysis of RCTs involving dorsal rhizotomy and physical therapy versus physical therapy confirmed reduced lower-limb spasticity and increased gross motor function (4.5%, P = .002). Observational studies reported statistically significant improvements in gross motor function over 2 years or less (12 studies, GRADE moderate) and over more than 2 years (10 studies, GRADE moderate) as well as improvements in functional independence in the short term (10 studies, GRADE moderate) and long term (4 studies, GRADE low). Major operative complications, were infrequently reported (4 studies). Bony abnormalities and instabilities monitored radiologically in the spine (15 studies) and hip (8 studies) involved minimal or clinically insignificant changes after surgery. No studies evaluated the cost effectiveness of dorsal rhizotomy. The budget impact of

  12. Lumbosacral Dorsal Rhizotomy for Spastic Cerebral Palsy: A Health Technology Assessment.

    Science.gov (United States)

    2017-01-01

    Cerebral palsy, a spectrum of neuromuscular conditions caused by abnormal brain development or early damage to the brain, is the most common cause of childhood physical disability. Lumbosacral dorsal rhizotomy is a neurosurgical procedure that permanently decreases spasticity and is always followed by physical therapy. The objectives of this health technology assessment were to evaluate the clinical effectiveness, safety, cost effectiveness, and family perspectives of dorsal rhizotomy. We performed a systematic literature search until December 2015 with auto-alerts until December 2016. Search strategies were developed by medical librarians, and a single reviewer reviewed the abstracts. The health technology assessment included a clinical review based on functional outcomes, safety, and treatment satisfaction; an economic study reviewing cost-effective literature; a budget impact analysis; and interviews with families evaluating the intervention. Eighty-four studies (1 meta-analysis, 5 randomized controlled studies [RCTs], 75 observational pre-post studies, and 3 case reports) were reviewed. A meta-analysis of RCTs involving dorsal rhizotomy and physical therapy versus physical therapy confirmed reduced lower-limb spasticity and increased gross motor function (4.5%, P = .002). Observational studies reported statistically significant improvements in gross motor function over 2 years or less (12 studies, GRADE moderate) and over more than 2 years (10 studies, GRADE moderate) as well as improvements in functional independence in the short term (10 studies, GRADE moderate) and long term (4 studies, GRADE low). Major operative complications, were infrequently reported (4 studies). Bony abnormalities and instabilities monitored radiologically in the spine (15 studies) and hip (8 studies) involved minimal or clinically insignificant changes after surgery. No studies evaluated the cost effectiveness of dorsal rhizotomy. The budget impact of funding dorsal rhizotomy for

  13. Radiofrequency thermocoagulation rhizotomy for recurrent trigeminal neuralgia after microvascular decompression

    Institute of Scientific and Technical Information of China (English)

    ZHANG Liang-wen; LIU Yu-guang; WU Cheng-yuan; XU Shu-jun; ZHU Shu-gan

    2011-01-01

    Background Microvascular decompression (MVD) is a well accepted surgical treatment strategy for trigeminal neuralgia (TN) with satisfying long-term outcome.However,considerable recurrent patients need more effective management.The purpose of this study was to evaluate the effectiveness of radiofrequency thermocoagulation rhizotomy (RTR) on patients with recurrent TN after MVD.Methods Totally 62 cases of recurrent TN after MVD undergoing RTR from January 2000 to January 2010 were retrospectively evaluated.Based on surgical procedures undertaken,these 62 cases were classified into two subgroups:group A consisted of 23 cases that underwent traditional RTR by free-hand; group B consisted of 39 cases that underwent RTR under the guidance of virtual reality imaging technique or neuronavigation system.The patients in group Awere followed up for 14 to 70 months (mean,40±4),and those in group B were followed up for 13 to 65 months (mean,46±7).Kaplan-Meier analyses of the pain-free survival curves were used for the censored survival data,and the log-rank test was used to compare survival curves of the two groups.Results All patients in both groups A and B attained immediate pain relief after RTR.Both groups attained good pain relief rate within the first two years of follow-up:92.3%,84.6% and 82.6%,69.6% respectively (P >0.05).After 2 years,the virtual reality or neuronavigation assisted RTR group (group B) demonstrated higher pain relief rates of 82.5%,76.2% and 68.8% at 3,4 and 5 years after operation respectively,while those in group A was 57.2%,49.6%,and 36.4% (P <0.05).Low levels of minor complications were recorded,while neither mortalities nor significant morbidity was documented.Conclusions RTR was effective in alleviating the pain of TN cases suffering from unsuccessful MVD management.With the help of virtual reality imaging technique or neuronavigation system,the patients could attain better long-term pain relief.

  14. Web-based VR training simulator for percutaneous rhizotomy.

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    Li, Y; Brodlie, K; Phillips, N

    2000-01-01

    Virtual Reality offers great potential for surgical training--yet is typically limited by the dedicated and expensive equipment required. Web-based VR has the potential to offer a much cheaper alternative, in which simulations of fundamental techniques are downloaded from a server to run within a web browser. The equipment requirement is modest--an Internet-connected PC or small workstation--and the simulation can be accessed worldwide. In a collaboration between computer scientists and neurosurgeons, we have studied the use of web-based VR to train neurosurgeons in Percutaneous Rhizotomy--a treatment for the intractable facial pain which occurs in trigeminal neuralgia. This involves the insertion of a needle so as to puncture the foramen ovale, and lesion the nerve. Our simulation uses VRML to provide a 3D visualization environment, but the work immediately exposes a key limitation of VRML for surgical simulation. VRML does not support collision detection between objects--only between viewpoint and object. Thus collision between needle and skull cannot be detected and fed back to the trainee. We have developed a novel solution in which the training simulation has linked views: a normal view, plus a view as seen from the tip of the needle. Collision detection is captured in the needle view, and fed back to the viewer. A happy consequence of this approach has been the chance to aid the trainee with this additional view from needle tip, which helps locate the foramen ovale. The technology to achieve this is Java software communicating with the VRML worlds through the External Authoring Interface (EAI). The training simulator is available on the Web, with accompanying tutorial on its use. A major advantage of web-based VR is that the techniques generalize to a whole range of surgical simulations. Thus we have been able to use exactly the same approach as described above for neurosurgery, to develop a shoulder arthroscopy simulator--where again collision detection, and

  15. Beneficial Effects of Childhood Selective Dorsal Rhizotomy in Adulthood.

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    Park, T S; Edwards, Caleb; Liu, Jenny L; Walter, Deanna M; Dobbs, Matthew B

    2017-03-05

     Selective dorsal rhizotomy (SDR) has been used to treat children with spastic cerebral palsy (CP) for over three decades. However, little is known about the outcomes of childhood SDR in adults.  Objectives: 1) To study the effects of childhood SDR on the quality of life and ambulatory function in adult life. 2) To determine late side effects of SDR in adults.   Methods: Adults (> 17.9 years) who underwent SDR in childhood (2 - 17.9 years) between 1987 and 2013 were surveyed in 2015. Patients completed a survey, including questions on demographic information, quality of life, health, surgical outcomes, motor function, manual ability, pain, braces/orthotics, post-SDR treatment, living situation, education level, work status, and side effects of SDR.  Results: In our study population of 294 patients (18.0 - 37.4 years), patients received SDR during the ages of 2.0 - 17.9 years and were followed up 2.2 to 28.3 years after surgery. Eighty-four percent had spastic diplegia, 12% had spastic quadriplegia, and 4% had spastic triplegia. The majority (88%) of patients reported improved post-SDR quality of life and 1% considered the surgery detrimental. Most (83%) would recommend the procedure to others and 3% would not. However, patients who would not recommend SDR to others ambulated with a walker or were not ambulatory at all prior to SDR. The majority (83%) of patients improved (30%) or remained stable (53%) in ambulation. Twenty-nine percent of patients reported pain, mostly in the back and lower limbs, with a mean pain level of 4.4 ± 2.4 on the Numeric Pain Rating Scale (NPRS). Decreased sensation in small areas of the lower limbs was reported by 8% of patients, though this did not affect daily life. Scoliosis was diagnosed in 28%, with 40% of these patients pursuing treatment. Whether scoliosis was related to SDR is not clear, though scoliosis is known to occur in patients with CP and also in the general population. Only 4% of patients underwent spinal fusion

  16. Percutaneous high-frequency selective rhizotomy in the trigeminal neuralgia therapy in multiple sclerosis

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    V. M. Tyurnikov

    2012-01-01

    Full Text Available Trigeminal neuralgia is a rare symptom of multiple sclerosis affecting the disability. Multiple sclerosis related trigeminal neuralgia has been attributed to a demyelinating lesion in the pons. When the adequate pain drug-relieve therapy is not possible or when the patient becomes refractory to the treatment or can not continue pharmacological treatment because of the side effects, surgical intervention, including percutaneous radiofrequency rhizotomy is being discussed. Literature review and the data upon the efficiency and safety of this neurosurgical treatment in 16 patients with multiple sclerosis have been analyzed. Percutaneous radiofrequency rhizotomy has been proved to be a safe, reproducible and effective method of the symptomatic surgical treatment of trigeminal neuralgia in patients with multiple sclerosis in cases of the intolerance/inefficiency of the pharmacological therapy.

  17. [Posterior selective rhizotomy in the treatment of severe spastic syndrome in cerebral palsy].

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    Shabalov, V A; Dekopov, A V; Tomskiĭ, A A; Salova, E M

    2010-01-01

    Aim of this study was to optimize surgical technique of posterior selective rhizotomy for prevention of possible complications. 11 patients (age 3-30 years) with severe spastic tetraparesis due to cerebral palsy were operated. Muscle tone in lower limbs reached 4-5 points (Ashworth scale). In all cases posterior selective rhizotomy of L1-S1 spinal roots was performed using laminoplasty and intraoperative electromyographic monitoring. Results were assessed in early postoperative period and during follow-up. In all cases in the early postoperative period we observed decrease of muscle tone to 1-2 points and increase of volume of passive movements. In the follow-up period 4 patients developed improvement of locomotor status, in 6 no changes were observed. In 1 case spastic syndrome recurred. We had no complications due to orthopaedic deformities of spinal column, sensory and pelvic disorders, muscular hypotonia. Posterior selective rhizotomy may be the method of choice in treatment of patients with severe spastic forms of cerebral palsy. Application of optimized surgical technique (laminoplasty, intraoperative stimulation electromyography) allows to decrease the risk of possible complications.

  18. Combined Anterior and Posterior Lumbar Rhizotomy for Treatment of Mixed Dystonia and Spasticity in Children With Cerebral Palsy

    Science.gov (United States)

    Nada, Mohamed; Mahran, Mahmoud A.; Aboud, Ahmed; Mahran, Moustafa G.; Nasef, Marwa A.A.; Gaber, Mohamed; Sabry, Tamer; Ibrahim, Mohamed H.; Taha, Mohamed H.

    2016-01-01

    BACKGROUND: Children with cerebral palsy (CP) can present with severe secondary dystonia with or without associated spasticity of their extremities. OBJECTIVE: To assess the outcomes of combined anterior and posterior lumbar rhizotomy for the treatment of mixed hypertonia in the lower extremities of children with CP. METHODS: Fifty children with CP were subjected to combined anterior and posterior lumbar rhizotomies in a prospective study. Clinical outcome measurements were recorded preoperatively and were evaluated at 2, 6, and 12 months postoperatively. The operative techniques were performed by laminotomy from L1-S1, and intraoperative monitoring was used in all cases. All patients underwent intensive postoperative physiotherapy programs. RESULTS: Changes in muscle tone, joint range of motion, and dystonia were significant (P = .000) at postoperative assessment visits. CONCLUSION: This study demonstrated the potential of combined anterior and posterior lumbar rhizotomies to improve activities of daily living in children with CP and with mixed spasticity and dystonia. ABBREVIATIONS: BAD, Barry-Albright Dystonia Scale CAPR, combined anterior and posterior lumbar rhizotomy CP, cerebral palsy ITB, intrathecal baclofen MAS, modified Ashworth Scale ROM, range of motion SDR, selective dorsal rhizotomy PMID:27244465

  19. Biological Conversion of Glycerol to Ethanol by Enterobacter aerogenes

    Science.gov (United States)

    Nwachukwu, Raymond E. S.

    In a search to turn the economically and environmentally non-valuable "waste" streams of biodiesel production into a profitable byproduct, a mutant strain of Enterobacter aerogenes ATCC 13048 was developed by six-tube subculturing technique. This technique is based on the principle of adaptive evolution, and involved subculturing the bacterium in a tryptic soy broth without dextrose (TSB) containing specific glycerol and ethanol concentration for six consecutive times. Then, the six consecutive subculturing was repeated in a fresh TSB of higher glycerol and ethanol concentrations. A new mutant strain, E. aerogenes S012, which could withstand a combination of 200 g/l glycerol and 30 g/l ethanol concentrations, was developed. The wild and mutant strains were used for the fermentation of pure (P-) and recovered (R-) glycerol. Taguchi and full factorial methods of design of experiments were used to screen and optimize the important process factors that influence the microbial production of ethanol. A statistically sound regression model was used to establish the mathematical relationship between the process variables and ethanol production. Temperature of 38°C, agitation speed of 200 rpm, pH of 6.3-6.6, and microaerobic condition were the optimum process conditions. Different pretreatment methods to recover glycerol from the crude glycerol and the subsequent fermentation method showed that direct acidification using 85% H3PO4 was the best. The R-glycerol contained 51% pure glycerol and 21% methanol. The wild strain, E. aerogenes ATCC 13048, produced only 12 g/l and 12.8 g/l ethanol from 20 g/l P- and R-glycerol respectively, and could not utilize higher glycerol concentrations. The mutant, E. aerogenes S012, produced ethanol amount and yield of 43 g/l and 1.12 mol/mol-glycerol from P-glycerol, respectively within 96 h. It also produced ethanol amount and yield of 26.8 g/l and 1.07 mol/mol-glycerol, respectively, from R-glycerol within the same duration. In a

  20. Percutaneous radiofrequency rhizotomy of lumbar spinal facets: the results of 46 cases.

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    Göçer, A I; Cetinalp, E; Tuna, M; Ildan, F; Bağdatoğlu, H; Haciyakupoğlu, S

    1997-01-01

    The results of percutaneous radiofrequency rhizotomy of lumbar spinal facets in 46 patients followed at least three months (mean 15 months) are reported and compared with those reported previously. Satisfactory pain relief three months after the procedure was achieved in 36.4 percent of patients without operations and in 41.7 percent of patients, with operations other than fusion. No patient had previously undergone fusion. Treatment of low-back pain by using radio-frequency thermocoagulation of spinal facets is a simple, safe, and well-tolerated procedure. It can be used to relief of pain in spite of decreasing rates of success within the follow-up period.

  1. Does Loss of Spasticity Matter? A 10-Year Follow-up after Selective Dorsal Rhizotomy in Cerebral Palsy

    Science.gov (United States)

    Tedroff, Kristina; Lowing, Kristina; Jacobson, Dan N. O.; Astrom, Eva

    2011-01-01

    Aim: The aim of this study was to evaluate the long-term effects of selective dorsal rhizotomy (SDR) in children with cerebral palsy (CP). Method: Nineteen children (four females, 15 males; mean age 4y 7mo, SD 1y 7mo) with bilateral spastic CP, were prospectively assessed at baseline and 18 months, 3 years, and 10 years after SDR. Assessments…

  2. Endosurgical repair of an iatrogenic facial arteriovenous fistula due to percutaneous trigeminal balloon rhizotomy.

    Science.gov (United States)

    Lesley, W S

    2007-12-01

    A 56-year-old woman with right-sided trigeminal neuralgia (TN), who underwent technically uneventful percutaneous balloon rhizotomy, developed significant bilateral pulsatile tinnitus on the first post-operative day. Although the patient reported significantly improved neuralgia, auscultation revealed a right facial bruit. Magnetic resonance angiography (MRA) of the face and brain demonstrated prominent right facial and jugular venous vascularity. Catheter angiography confirmed the suspected facial arteriovenous fistula (AVF). A transarterial approach was used to explore the AVF which arose from a laceration of the right internal maxillary artery and which fistulized directly with the pterygoid venous plexus. Endosurgical repair utilizing three non-fibered platinum coils was done under conscious sedation at the same setting as the diagnostic angiogram. Angiographically, the fistula was obliterated, and the patient's bruit and tinnitus immediately resolved. Follow-up MRA at 3.5 months was normal, and, the patient had no clinical symptoms of recurrent AVF. In conclusion facial AVF can complicate percutaneous trigeminal rhizotomy. Iatrogenic facial AVF can be repaired via an endovascular approach.

  3. Surgical treatment of spasticity by selective posterior rhizotomy: 30 years experience.

    Science.gov (United States)

    Salame, Khalil; Ouaknine, Georges E R; Rochkind, Semion; Constantini, Shlomo; Razon, Nissim

    2003-08-01

    Spasticity is a common neurologic disorder with adverse effects on the patient's function. Conservative management is unsuccessful in a significant proportion of patients and neurosurgical intervention should be considered. The mainstay of surgical treatment of spasticity is selective posterior rhizotomy, i.e., section of sensory nerve roots of the cauda equina. To report our experience with selective posterior rhizotomy in the treatment of spasticity. We retrospectively reviewed our experience in 154 patients who underwent SPR during 30 years. The indication for surgery was spasticity that significantly hindered the patient's function or care and was resistant to conservative treatment. All patients were evaluated for spasticity in the lower and upper limbs, the presence or absence of painful spasms, and sphincter disturbances. The decision as to which roots to be sectioned, and to what extent, was based mainly on clinical muscle testing. Reduction of spasticity in the lower limbs was obtained in every case, with improvement in movements in 86% of cases. Painful spasms were alleviated in 80% of cases. Amelioration of neurogenic bladder was observed in 42%. A minority of the patients also showed improvement in speech and cognitive performance. There was no perioperative mortality or major complications. SPR is a safe and effective method for the treatment of spasticity with long-lasting beneficial effects. We suggest that this method be considered more frequently for patients with spasticity that interferes with their quality of life.

  4. Selective dorsal rhizotomy opportunities with foot deformitiesin children with cerebral palsy

    Directory of Open Access Journals (Sweden)

    Владимир Маркович Кенис

    2015-03-01

    Full Text Available Foot deformities are the most common orthopedic condition in children with cerebral palsy. The aim of the study was to evaluate the influence of selective dorsal rhizotomy (SDR on foot deformities in children with cerebral palsy. The results were assessed clinically by measurement of changes in muscle spaticity and foot posture. Percentage of resection of dorsal rootlets was from 40 to 90 % of total thickness. The degree of tone reduction had a tendency to be more pronounced in the more proximal muscles and was minimal in calf muscles. Nevertheless, foot posture improved more significantly. That can be explained by generalimprovement of pathological posture at the level of more proximal joints. Thus, SDR has insignificant direct effect on spastic foot deformity and can not be recommended as a basic method of treatment even in pure spasticity. However, SDR should be considered as a part of multidisciplinary management protocol if foot deformity reflects more complex postural disturbance due to generalized spasticity.

  5. Disappearance of spasticity after selective dorsal rhizotomy does not prevent muscle shortening in children with cerebral palsy: a case report.

    Science.gov (United States)

    Spijker, Margje; Strijers, Rob L M; van Ouwerkerk, Willem J R; Becher, Jules G

    2009-05-01

    Selective dorsal rhizotomy is an effective treatment for spasticity in children with cerebral palsy who have a spastic motor disorder. It is hypothesized that muscle shortening is related to spasticity; the lack of stretch of a muscle is thought to be the cause of muscle shortening. If this is true, the treatment for spasticity should prevent the occurrence of muscle shortening during growth. We present the case of 1 child with cerebral palsy and spastic diplegia, for whom the treatment with selective dorsal rhizotomy was successful in improving the walking abilities. She did, however, develop muscle shortening during growth. In conclusion, the development of muscle shortening during growth in children with cerebral palsy and spastic paresis cannot be prevented by treatment for the spasticity alone.

  6. Isolation and chemical characterization of phosphatidyl glycerol from spinach leaves

    NARCIS (Netherlands)

    Haverkate, E.; Deenen, L.L.M. van

    1965-01-01

    Pure phosphatidyl glycerol was obtained from spinach leaves after repeated chromatography on silica columns. Ascertainment of the configuration of the hydrolysis products formed by the action of phospholipases C (EC 3.1.4.3) and D (EC 3.1.4.4) demonstrated that this phospholipid is identical with 1,

  7. THREE-DIMENSIONAL COMPUTED TOMOGRAPHY-GUIDED RADIOFREQUENCY TRIGEMINAL RHIZOTOMY FOR TREATMENT OF IDIOPATHIC TRIGEMINAL NEURALGIA

    Institute of Scientific and Technical Information of China (English)

    Meng Liu; Cheng-yuan Wu; Yu-guang Liu; Hong-wei Wang; Fan-gang Meng

    2005-01-01

    Objective To evaluate the effectiveness of three-dimensional computed tomography (3D-CT) guided radiofrequency trige minal rhizotomy (RF-TR) in treatment of idiopathic trigeminal neuralgia (ITN). Methods From 1999 to 2001, 18 patients with ITN were treated with percutaneous controlled RF-TR. Intraoperative 3D-CT scanning was performed to guide the trajectory of the puncture. After correction of the needle tip according to the CT scans and stimulation effects, 2 to 5 lesions were made for a duration of 60-90 seconds at a temperature of 60℃ to 75℃ depend ing on the pain distribution and the age of patient. Results The needles located in foramen ovale. Pain alleviated immediately with no serious complication in all patients. The patients were followed up for an average of 31.5 months (range 24-41 months). Acute pain relief was experienced by 17 patients after the procedure, reaching an initial success rate of 94.4%. Early (< 6 months) pain recurrence was observed in 2 patients (11.1%), whereas late (> 6 months) recurrence was reported in 3 patients (16.7%). Thirteen patients had complete pain control, with no need for medication thereafter. Five cases experienced partial pain relief, but required medication at a lower dose than in the preoperative period. Conclusion 3D-CT foramen ovale locations can raise the successful rate of puncture, enhance the safety, and reduce the incidence rate of complication.

  8. 选择性腰骶脊神经后根切断术治疗脑性瘫痪儿的下肢痉挛%Management of lower limbs spasm following cerebral palsy using selective posterior rhizotomy

    Institute of Scientific and Technical Information of China (English)

    贺文; 徐梅; 汪枚初; 韩赛平; 杨俊

    2002-01-01

    Objective To investigate therapeutic effect of selective posterior rhizotomy in the treatment of lower limbs spasm following cerebral palsy.Method 106 cases received selective posterior rhizotomy.Postoperational follow up was carried for 6~ 36 months,averagely 18 months.Result All cases showed complete relief in muscular spasm,decreased muscular tension.Ashworth grade (1~ 1.5)was 1.3.Dynamic abnormality in joints were all corrected.Conclusion Selective posterior rhizotomy can effectively relieve lower limbs spasm,reduce muscular tension and correct dynamic joint abnormality.

  9. Using Diffusion Tensor Imaging to Evaluate Microstructural Changes and Outcomes after Radiofrequency Rhizotomy of Trigeminal Nerves in Patients with Trigeminal Neuralgia.

    Science.gov (United States)

    Chen, Shu-Tian; Yang, Jen-Tsung; Yeh, Mei-Yu; Weng, Hsu-Huei; Chen, Chih-Feng; Tsai, Yuan-Hsiung

    2016-01-01

    Trigeminal neuralgia is characterized by facial pain that may be sudden, intense, and recurrent. Our aim was to investigate microstructural tissue changes of the trigeminal nerve in patients with trigeminal neuralgia resulting from neurovascular compression by diffusion tensor imaging, and to test the predictive value of diffusion tensor imaging for determining outcomes after radiofrequency rhizotomy. Forty-three patients with trigeminal neuralgia were recruited, and diffusion tensor imaging was performed before radiofrequency rhizotomy. By selecting the cisternal segment of the trigeminal nerve manually, we measured the volume of trigeminal nerve, fractional anisotropy, apparent diffusion coefficient, axial diffusivity, and radial diffusivity. The apparent diffusion coefficient and mean value of fractional anisotropy, axial diffusivity, and radial diffusivity were compared between the affected and normal side in the same patient, and were correlated with pre-rhizotomy and post-rhizotomy visual analogue scale pain scores. The results showed the affected side had significantly decreased fractional anisotropy, increased apparent diffusion coefficient and radial diffusivity, and no significant change of axial diffusivity. The volume of the trigeminal nerve on affected side was also significantly smaller. There was a trend of fractional anisotropy reduction and visual analogue scale pain score reduction (P = 0.072). The results suggest that demyelination without axonal injury, and decreased size of the trigeminal nerve, are the microstructural abnormalities of the trigeminal nerve in patients with trigeminal neuralgia caused by neurovascular compression. The application of diffusion tensor imaging in understanding the pathophysiology of trigeminal neuralgia, and predicting the treatment effect has potential and warrants further study.

  10. Lumbar Radiofrequency Rhizotomy in Patients with Chronic Low Back Pain Increases the Diagnosis of Sacroiliac Joint Dysfunction in Subsequent Follow-Up Visits.

    Science.gov (United States)

    Rimmalapudi, Varun Kumar; Kumar, Sanjeev

    2017-01-01

    Chronic back pain is often a result of coexisting pathologies; secondary causes of pain can become more apparent sources of pain once the primary pathology has been addressed. The objective of our study was to determine if there is an increase in diagnosis of Sacroiliac joint pain following a Lumbar Rhizotomy. A list of patients who underwent Lumbar Radiofrequency during a 6-month period in our clinic was generated. Records from subsequent clinic visits were reviewed to determine if a new diagnosis of SI joint pathology was made. In patients who underwent a recent Lumbar Rhizotomy procedure to treat facetogenic pain, the prevalence of Sacroiliac joint pain increased to 70%. We infer that there is a significant increase in the diagnosis of Sacroiliac joint syndrome following a Lumbar Rhizotomy, potentially due to unmasking of a preexisting condition. In patients presenting with persistent back pain after Lumbar Rhizotomy, the clinician must have a high degree of suspicion for latent Sacroiliac joint pain prior to attributing the pain to block failure. It would be prudent to use >80% relief of pain after a diagnostic medial branch block as a diagnostic criterion for facetogenic pain rather than the currently accepted >50% in order to minimize unmasking of preexisting subclinical pain from the SI joint.

  11. Lumbar Radiofrequency Rhizotomy in Patients with Chronic Low Back Pain Increases the Diagnosis of Sacroiliac Joint Dysfunction in Subsequent Follow-Up Visits

    Directory of Open Access Journals (Sweden)

    Varun Kumar Rimmalapudi

    2017-01-01

    Full Text Available Chronic back pain is often a result of coexisting pathologies; secondary causes of pain can become more apparent sources of pain once the primary pathology has been addressed. The objective of our study was to determine if there is an increase in diagnosis of Sacroiliac joint pain following a Lumbar Rhizotomy. A list of patients who underwent Lumbar Radiofrequency during a 6-month period in our clinic was generated. Records from subsequent clinic visits were reviewed to determine if a new diagnosis of SI joint pathology was made. In patients who underwent a recent Lumbar Rhizotomy procedure to treat facetogenic pain, the prevalence of Sacroiliac joint pain increased to 70%. We infer that there is a significant increase in the diagnosis of Sacroiliac joint syndrome following a Lumbar Rhizotomy, potentially due to unmasking of a preexisting condition. In patients presenting with persistent back pain after Lumbar Rhizotomy, the clinician must have a high degree of suspicion for latent Sacroiliac joint pain prior to attributing the pain to block failure. It would be prudent to use >80% relief of pain after a diagnostic medial branch block as a diagnostic criterion for facetogenic pain rather than the currently accepted >50% in order to minimize unmasking of preexisting subclinical pain from the SI joint.

  12. Lumbar Radiofrequency Rhizotomy in Patients with Chronic Low Back Pain Increases the Diagnosis of Sacroiliac Joint Dysfunction in Subsequent Follow-Up Visits

    Science.gov (United States)

    2017-01-01

    Chronic back pain is often a result of coexisting pathologies; secondary causes of pain can become more apparent sources of pain once the primary pathology has been addressed. The objective of our study was to determine if there is an increase in diagnosis of Sacroiliac joint pain following a Lumbar Rhizotomy. A list of patients who underwent Lumbar Radiofrequency during a 6-month period in our clinic was generated. Records from subsequent clinic visits were reviewed to determine if a new diagnosis of SI joint pathology was made. In patients who underwent a recent Lumbar Rhizotomy procedure to treat facetogenic pain, the prevalence of Sacroiliac joint pain increased to 70%. We infer that there is a significant increase in the diagnosis of Sacroiliac joint syndrome following a Lumbar Rhizotomy, potentially due to unmasking of a preexisting condition. In patients presenting with persistent back pain after Lumbar Rhizotomy, the clinician must have a high degree of suspicion for latent Sacroiliac joint pain prior to attributing the pain to block failure. It would be prudent to use >80% relief of pain after a diagnostic medial branch block as a diagnostic criterion for facetogenic pain rather than the currently accepted >50% in order to minimize unmasking of preexisting subclinical pain from the SI joint. PMID:28255260

  13. Meningitis and Bacteremia Due to Neisseria cinerea following a Percutaneous Rhizotomy of the Trigeminal Ganglion.

    Science.gov (United States)

    von Kietzell, M; Richter, H; Bruderer, T; Goldenberger, D; Emonet, S; Strahm, C

    2016-01-01

    Neisseria cinerea is a human commensal. The first known case of meningitis and bacteremia due to Neisseria cinerea following percutaneous glycerol instillation of the trigeminal ganglion is reported. Conventional phenotypic methods and complete 16S RNA gene sequencing accurately identified the pathogen. Difficulties in differentiation from pathogenic neisseriae are discussed.

  14. Meningitis and Bacteremia Due to Neisseria cinerea following a Percutaneous Rhizotomy of the Trigeminal Ganglion

    OpenAIRE

    von Kietzell, M.; Richter, H.; Bruderer, T.; Goldenberger, D.; Emonet, S; Strahm, C.

    2015-01-01

    Neisseria cinerea is a human commensal. The first known case of meningitis and bacteremia due to Neisseria cinerea following percutaneous glycerol instillation of the trigeminal ganglion is reported. Conventional phenotypic methods and complete 16S RNA gene sequencing accurately identified the pathogen. Difficulties in differentiation from pathogenic neisseriae are discussed.

  15. Kinetic enzymatic determination of glycerol in wine and beer using a sequential injection system with spectrophotometric detection.

    Science.gov (United States)

    Oliveira, Hugo M; Segundo, Marcela A; Lima, José L F C; Grassi, Viviane; Zagatto, Elias A G

    2006-06-14

    A sequential injection system for the automatic determination of glycerol in wine and beer was developed. The method is based on the rate of formation of NADH from the reaction of glycerol and NAD+ catalyzed by the enzyme glycerol dehydrogenase in solution. The determination of glycerol was performed between 0.3 and 3.0 mmol L(-1) (0.028 and 0.276 g L(-1)), and good repeatability was attained (rsd production was 2.12 mL per assay. Results obtained for samples were in agreement with those obtained with the batch enzymatic method.

  16. Characterization of crude glycerol from biodiesel plants.

    Science.gov (United States)

    Hu, Shengjun; Luo, Xiaolan; Wan, Caixia; Li, Yebo

    2012-06-13

    Characterization of crude glycerol is very important to its value-added conversion. In this study, the physical and chemical properties of five biodiesel-derived crude glycerol samples were determined. Three methods, including iodometric-periodic acid method, high performance liquid chromatography (HPLC), and gas chromatography (GC), were shown to be suitable for the determination of glycerol content in crude glycerol. The compositional analysis of crude glycerol was successfully achieved by crude glycerol fractionation and characterization of the obtained fractions (aqueous and organic) using titrimetric, HPLC, and GC analyses. The aqueous fraction consisted mainly of glycerol, methanol, and water, while the organic fraction contained fatty acid methyl esters (FAMEs), free fatty acids (FFAs), and glycerides. Despite the wide variations in the proportion of their components, all raw crude glycerol samples were shown to contain glycerol, soap, methanol, FAMEs, water, glycerides, FFAs, and ash.

  17. Glycerol inhibition of ruminal lipolysis in vitro

    Science.gov (United States)

    Supplemental glycerol inhibits rumen lipolysis, a prerequisite for rumen biohydrogenation, which is responsible for the saturation of dietary fatty acids consumed by ruminant animals. Feeding excess glycerol, however, adversely affects dry matter digestibility. To more clearly define the effect of...

  18. Glycerol based solvents: synthesis, properties and applications

    OpenAIRE

    García, José I.; García-Marín, Héctor; Pires, Elísabet

    2014-01-01

    The most recent advances in the use of glycerol and glycerol derivatives as solvents are reviewed. There are an increasing number of examples of the use of glycerol itself as a reaction medium, solvent-reagent or a dispersive medium for a large variety of applications. In the case of glycerol derivatives, new synthetic methods, physico-chemical properties and application examples as solvents are revised. Recent studies in the field of solvent classification, as well as solvent substitution is...

  19. Esters of oligo-(glycerol carbonate-glycerol): New biobased oligomeric surfactants.

    Science.gov (United States)

    Holmiere, Sébastien; Valentin, Romain; Maréchal, Philippe; Mouloungui, Zéphirin

    2017-02-01

    Glycerol carbonate is one of the most potentially multifunction glycerol-derived compounds. Glycerol is an important by-product of the oleochemical industry. The oligomerization of glycerol carbonate, assisted by the glycerol, results in the production of polyhydroxylated oligomers rich in linear carbonate groups. The polar moieties of these oligomers (Mwesters of sorbitan polyethoxylates. The self-assembling properties of oligocarbonate esters were highlighted by their ability to stabilize inverse and multiple emulsions. The oligo-(glycerol carbonate-glycerol ether) with relatively low molecular weights showed properties of relatively high-molecular weight molecules, and constitute a viable "green" alternative to ethoxylated surfactants. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Biohydrogen Production from Glycerol using Thermotoga spp

    NARCIS (Netherlands)

    Maru, B.T.; Bielen, A.A.M.; Kengen, S.W.M.; Constantini, M.; Medina, F.

    2012-01-01

    Given the highly reduced state of carbon in glycerol and its availability as a substantial byproduct of biodiesel production, glycerol is of special interest for sustainable biofuel production. Glycerol was used as a substrate for biohydrogen production using the hyperthermophilic bacterium, Thermot

  1. The Lubricity of Glycerol and its Solutions

    DEFF Research Database (Denmark)

    Sivebæk, Ion Marius; Jakobsen, J.

    2016-01-01

    Glycerol has been recognised as an excellent diesel fuel and lubricant. It is a liquid that can originate from the transesterification of plant oil that also results in plant oil metyl (or ethyl) ester (biodiesel). Machine elements lubricated by glycerol show very low friction, in fact lower than...... the one predicted by hydrodynamic lubrication calculations. Addition of water to glycerol lowers the friction but increases the wear. In the present paper the lubricity (boundary lubrication performance) of glycerol and its solutions with water, ethanol and methanol is investigated. Dilution of glycerol...

  2. Microbial fed-batch production of 1,3-propanediol using raw glycerol with suspended and immobilized Klebsiella pneumoniae.

    Science.gov (United States)

    Jun, Sun-Ae; Moon, Chuloo; Kang, Cheol-Hee; Kong, Sean W; Sang, Byoung-In; Um, Youngsoon

    2010-05-01

    The production of 1,3-propanediol (1,3-PD) was investigated with Klebsiella pneumoniae DSM 4799 using raw glycerol without purification obtained from a biodiesel production process. Fed-batch cultures with suspended cells revealed that 1,3-PD production was more effective when utilizing raw glycerol than pure glycerol (productivity after 47 h of fermentation, 0.84 g L(-1) 1 h(-1) versus 1.51 g L(-1) h(-1) with pure and raw glycerol,respectively). In addition, more than 80 g/L of 1,3-PD was produced using raw glycerol;this is the highest 1,3-PD concentration reported thus far for K. pneumoniae using raw glycerol. Repeated fed-batch fermentation with cell immobilization in a fixed-bed reactor was performed to enhance 1,3-PD production. Production of 1,3-PD increased with the cycle number (1.06 g L(-1) h(-1) versus 1.61 g L(-1) h(-1) at the first and fourth cycle, respectively)due to successful cell immobilization. During 46 cycles of fed-batch fermentation taking place over 1,460 h, a stable and reproducible 1,3-PD production performance was observed with both pure and raw glycerol. Based on our results, repeated fed batch with immobilized cells is an efficient fermentor configuration, and raw glycerol can be utilized to produce 1,3-PD without inhibitory effects caused by accumulated impurities.

  3. The science of conventional and water-cooled monopolar lumbar radiofrequency rhizotomy: an electrical engineering point of view.

    Science.gov (United States)

    Ball, Richard D

    2014-01-01

    Radiofrequency ablation (RFA) is a safe and effective pain therapy used to create sensory dysfunction in appropriate nerves via thermal damage. While commonly viewed as a simple process, RF heating is actually quite complex from an electrical engineering standpoint, and it is difficult for the non-electrical engineer to achieve a thorough understanding of the events that occur. RFA is highly influenced by the configuration and properties of the peri-electrode tissues. To rationally discuss the science of RFA requires that examples be procedure-specific, and lumbar RFA is the procedure selected for this review. Adequate heating of the lumbar medial branch has many potential failure points, and the underlying science is discussed with recommendations to reduce the frequency of failure in heating target tissues. Important technical details of the procedure that are not generally appreciated are discussed, and the status quo is challenged on several aspects of accepted technique. The rationale underlying electrode placement and the limitations of RF heating are, for the most part, commonly misunderstood, and there may even need to be significant changes in how lumbar radiofrequency rhizotomy (RFR) is performed. A new paradigm for heating target tissue may be of value. Foremost in developing best practices for this procedure is avoiding pitfalls. Good RF heating and medial branch lesioning are the rewards for understanding how the process functions, attention to detail, and meticulous attention to electrode positioning.

  4. The Effects of Selective Dorsal Rhizotomy on Balance and Symmetry of Gait in Children with Cerebral Palsy

    Science.gov (United States)

    Rumberg, Franziska; Bakir, Mustafa Sinan; Taylor, William R.; Haberl, Hannes; Sarpong, Akosua; Sharankou, Ilya; Lebek, Susanne; Funk, Julia F.

    2016-01-01

    Aim Cerebral palsy (CP) is associated with dysfunction of the upper motor neuron and results in balance problems and asymmetry during locomotion. Selective dorsal rhizotomy (SDR) is a surgical procedure that results in reduced afferent neuromotor signals from the lower extremities with the aim of improving gait. Its influence on balance and symmetry has not been assessed. The aim of this prospective cohort study was to evaluate the impact of SDR on balance and symmetry during walking. Methods 18 children (10 girls, 8 boys; age 6 years (y) 3 months (m), SD 1y 8m) with bilateral spastic CP and Gross Motor Function Classification System levels I to II underwent gait analysis before and 6 to 12 months after SDR. Results were compared to 11 typically developing children (TDC; 6 girls, 5 boys; age 6y 6m, SD 1y 11m). To analyse balance, sway velocity, radial displacement and frequency were calculated. Symmetry ratios were calculated for balance measures and spatio-temporal parameters during walking. Results Most spatio-temporal parameters of gait, as well as all parameters of balance, improved significantly after SDR. Preoperative values of symmetry did not vary considerably between CP and TDC group and significant postoperative improvement did not occur. Interpretation The reduction of afferent signalling through SDR improves gait by reducing balance problems rather than enhancing movement symmetry. PMID:27043310

  5. Crude Glycerol as Cost-Effective Fuel for Combined Heat and Power to Replace Fossil Fuels, Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, William L

    2012-10-31

    The primary objectives of this work can be summed into two major categories. Firstly, the fundamentals of the combustion of glycerol (in both a refined and unrefined form) were to be investigated, with emphasis of the development of a system capable of reliably and repeatedly combusting glycerol as well as an analysis of the emissions produced during glycerol combustion. Focus was placed on quantifying common emissions in comparison to more traditional fuels and this work showed that the burner developed was able to completely combust glycerol within a relatively wide range of operating conditions. Additionally, focus was placed on examining specific emissions in more detail, namely interesting NOx emissions observed in initial trials, acrolein and other volatile organic emissions, and particulate and ash emissions. This work showed that the combustion of crude glycerol could result in significantly reduced NOx emissions as a function of the high fuel bound oxygen content within the glycerol fuel. It also showed that when burned properly, the combustion of crude glycerol did not result in excessive emissions of acrolein or any other VOC compared to the combustion from more traditional fuels. Lastly however, this work has shown that in any practical application in which glycerol is being burned, it will be necessary to explore ash mitigation techniques due to the very high particulate matter concentrations produced during glycerol combustion. These emissions are comparable to unfiltered coal combustion and are directly tied to the biodiesel production method. The second focus of this work was directed to developing a commercialization strategy for the use of glycerol as a fuel replacement. This strategy has identified a 30 month plan for the scaling up of the laboratory scale burner into a pre-pilot scale system. Additionally, financing options were explored and an assessment was made of the economics of replacing a traditional fuel (namely natural gas) with crude

  6. Toward glycerol biorefinery: metabolic engineering for the production of biofuels and chemicals from glycerol.

    Science.gov (United States)

    Chen, Zhen; Liu, Dehua

    2016-01-01

    As an inevitable by-product of the biofuel industry, glycerol is becoming an attractive feedstock for biorefinery due to its abundance, low price and high degree of reduction. Converting crude glycerol into value-added products is important to increase the economic viability of the biofuel industry. Metabolic engineering of industrial strains to improve its performance and to enlarge the product spectrum of glycerol biotransformation process is highly important toward glycerol biorefinery. This review focuses on recent metabolic engineering efforts as well as challenges involved in the utilization of glycerol as feedstock for the production of fuels and chemicals, especially for the production of diols, organic acids and biofuels.

  7. The expression of glycerol facilitators from various yeast species improves growth on glycerol of Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Klein, Mathias; Islam, Zia ul; Knudsen, Peter Boldsen;

    2016-01-01

    of predicted glycerol facilitators (Fps1 homologues) from superior glycerol-utilizing yeast species such as Pachysolen tannophilus, Komagataella pastoris, Yarrowia lipolytica and Cyberlindnera jadinii significantly improves the growth performance on glycerol of the previously selected glycerol-consuming S....... cerevisiae wild-type strain (CBS 6412-13A). The maximum specific growth rate increased from 0.13 up to 0.18 h−1 and a biomass yield coefficient of 0.56 gDW/gglycerol was observed. These results pave the way for exploiting the assets of glycerol in the production of fuels, chemicals and pharmaceuticals based...

  8. Correlation spectroscopy applied to glycerol polyester spectra

    Science.gov (United States)

    The recent development of glycerol polyesters for use as controlled release matrix materials in the nutraceuticals and pharmaceuticals industries presented a unique opportunity to apply correlation spectroscopy. In a typical formulation the glycerol is reacted with a polyfunctional acid such as citr...

  9. From ether to acid: A plausible degradation pathway of glycerol dialkyl glycerol tetraethers

    Science.gov (United States)

    Liu, Xiao-Lei; Birgel, Daniel; Elling, Felix J.; Sutton, Paul A.; Lipp, Julius S.; Zhu, Rong; Zhang, Chuanlun; Könneke, Martin; Peckmann, Jörn; Rowland, Steven J.; Summons, Roger E.; Hinrichs, Kai-Uwe

    2016-06-01

    Glycerol dialkyl glycerol tetraethers (GDGTs) are ubiquitous microbial lipids with extensive demonstrated and potential roles as paleoenvironmental proxies. Despite the great attention they receive, comparatively little is known regarding their diagenetic fate. Putative degradation products of GDGTs, identified as hydroxyl and carboxyl derivatives, were detected in lipid extracts of marine sediment, seep carbonate, hot spring sediment and cells of the marine thaumarchaeon Nitrosopumilus maritimus. The distribution of GDGT degradation products in environmental samples suggests that both biotic and abiotic processes act as sinks for GDGTs. More than a hundred newly recognized degradation products afford a view of the stepwise degradation of GDGT via (1) ether bond hydrolysis yielding hydroxyl isoprenoids, namely, GDGTol (glycerol dialkyl glycerol triether alcohol), GMGD (glycerol monobiphytanyl glycerol diether), GDD (glycerol dibiphytanol diether), GMM (glycerol monobiphytanol monoether) and bpdiol (biphytanic diol); (2) oxidation of isoprenoidal alcohols into corresponding carboxyl derivatives and (3) chain shortening to yield C39 and smaller isoprenoids. This plausible GDGT degradation pathway from glycerol ethers to isoprenoidal fatty acids provides the link to commonly detected head-to-head linked long chain isoprenoidal hydrocarbons in petroleum and sediment samples. The problematic C80 to C82 tetraacids that cause naphthenate deposits in some oil production facilities can be generated from H-shaped glycerol monoalkyl glycerol tetraethers (GMGTs) following the same process, as indicated by the distribution of related derivatives in hydrothermally influenced sediments.

  10. Long-chain glycerol diether and polyol dialkyl glycerol triether lipids of Sulfolobus acidocaldarius.

    Science.gov (United States)

    Langworthy, T A; Mayberry, W R; Smith, P F

    1974-07-01

    Cells of Sulfolobus acidocaldarius contain about 2.5% total lipid on a dry-weight basis. Total lipid was found to contain 10.5% neutral lipid, 67.6% glycolipid, and 21.7% polar lipid. The lipids contained C(40)H(80) isopranol glycerol diethers. Almost no fatty acids were present. The glycolipids were composed of about equal amounts of the glycerol diether analogue of glucosyl galactosyl diglyceride and a glucosyl polyol glycerol diether. The latter compound contained an unidentified polyol attached by an ether bond to the glycerol diether. The polar lipids contained a small amount of sulfolipid, which appeared to be the monosulfate derivative of glucosyl polyol glycerol diether. About 40% of the lipid phosphorus was found in the diether analogue of phosphatidyl inositol. The remaining lipid phosphorus was accounted for by approximately equal amounts of two inositol monophosphate-containing phosphoglycolipids, inositolphosphoryl glucosyl galactosyl glycerol diether and inositolphosphoryl glucosyl polyol glycerol diether.

  11. Microbial recycling of glycerol to biodiesel.

    Science.gov (United States)

    Yang, Liu; Zhu, Zhi; Wang, Weihua; Lu, Xuefeng

    2013-12-01

    The sustainable supply of lipids is the bottleneck for current biodiesel production. Here microbial recycling of glycerol, byproduct of biodiesel production to biodiesel in engineered Escherichia coli strains was reported. The KC3 strain with capability of producing fatty acid ethyl esters (FAEEs) from glucose was used as a starting strain to optimize fermentation conditions when using glycerol as sole carbon source. The YL15 strain overexpressing double copies of atfA gene displayed 1.7-fold increase of FAEE productivity compared to the KC3 strain. The titer of FAEE in YL15 strain reached to 813 mg L(-1) in minimum medium using glycerol as sole carbon source under optimized fermentation conditions. The titer of glycerol-based FAEE production can be significantly increased by both genetic modifications and fermentation optimization. Microbial recycling of glycerol to biodiesel expands carbon sources for biodiesel production.

  12. Cervical dorsal rhizotomy increases brain-derived neurotrophic factor and neurotrophin-3 expression in the ventral spinal cord.

    Science.gov (United States)

    Johnson, R A; Okragly, A J; Haak-Frendscho, M; Mitchell, G S

    2000-05-15

    Although neurotrophic factors have been implicated in several forms of neuroplasticity, little is known concerning their potential role in spinal plasticity. Cervical dorsal rhizotomy (CDR) enhances serotonin terminal density near (spinal) phrenic motoneurons and serotonin-dependent long-term facilitation of phrenic motor output (Kinkead et al., 1998). We tested the hypothesis that selected neurotrophic factors change in a manner consistent with an involvement in this model of spinal plasticity. Brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), glial cell line-derived neurotrophic factor (GDNF), and transforming growth factor-beta(1) (TGF-beta(1)) concentrations were measured (ELISA) in three regions of interest to respiratory control: (1) ventral cervical spinal segments associated with the phrenic motor nucleus (C3-C6), (2) ventral thoracic spinal segments associated with inspiratory intercostal motor output (T3-T6) and (3) the diaphragm. Tissues were harvested from rats 7 d after bilateral CDR and compared with sham-operated and unoperated control rats. CDR increased BDNF (110%; p = 0.002) and NT-3 (100%; p = 0.002) in the cervical and NT-3 in the thoracic spinal cord (98%; p = 0.009). GDNF and TGF-beta(1) were not altered by CDR in any tissue. Immunohistochemistry localized BDNF and NT-3 to motoneurons and interneurons of the ventral spinal cord. These studies provide novel, suggestive evidence that BDNF and NT-3, possibly through their trophic effects on serotonergic neurons and/or motoneurons, may underlie serotonin-dependent plasticity in (spinal) respiratory motor control after CDR.

  13. 选择性脊神经后根切断术治疗痉挛性脑性瘫痪%Effects of selective posterior rhizotomy on spastic cerebral palsy

    Institute of Scientific and Technical Information of China (English)

    周南开; 车善理; 周波; 邓宗锵; 张建蓉; 杨学权

    2003-01-01

    AIM:To investigate the effects of selective posterior rhizotomy (SPR) to spastic cerebral palsy.METHODS:55 patients with spastic cerebral palsy who were treated with SPR between April 1999 and January 2002 were followed up and compared their changes of muscle force, muscle tone, the limb function preoperatively and postoperatively.RESULTS: 51 had selective lumbosacral posterior rhizotomy.In 35 cases who could not walk preoperatively,25 could walk alone.6 cases improved their gait and walk ability and 4 did not significantly.20 cases who walked claudicantly preoperatively,can walk nimbly and firmly.Their step width extended and gait improved apparently.4 cases had selective cervical posterior rhizotomy.They had their spasm of upper limbs relieved, joint function improved,and clawhand disappeared.In this group we didn't find severe complications.CONCLUSION: Selective posterior rhizotomy has curative effect to spastic cerebral palsy and has no severe complications.Its long term effects still need observations.

  14. Glycerol in micellar confinement with tunable rigidity

    Science.gov (United States)

    Lannert, Michael; Müller, Allyn; Gouirand, Emmanuel; Talluto, Vincenzo; Rosenstihl, Markus; Walther, Thomas; Stühn, Bernd; Blochowicz, Thomas; Vogel, Michael

    2016-12-01

    We investigate the glassy dynamics of glycerol in the confinement of a microemulsion system, which is stable on cooling down to the glass transition of its components. By changing the composition, we vary the viscosity of the matrix, while keeping the confining geometry intact, as is demonstrated by small angle X-ray scattering. By means of 2H NMR, differential scanning calorimetry, and triplet solvation dynamics we, thus, probe the dynamics of glycerol in confinements of varying rigidity. 2H NMR results show that, at higher temperatures, the dynamics of confined glycerol is unchanged compared to bulk behavior, while the reorientation of glycerol molecules becomes significantly faster than in the bulk in the deeply supercooled regime. However, comparison of different 2H NMR findings with data from calorimetry and solvation dynamics reveals that this acceleration is not due to the changed structural relaxation of glycerol, but rather due to the rotational motion of essentially rigid glycerol droplets or of aggregates of such droplets in a more fluid matrix. Thus, independent of the matrix mobility, the glycerol dynamics remains unchanged except for the smallest droplets, where an increase of Tg and, thus, a slowdown of the structural relaxation is observed even in a fluid matrix.

  15. Preparation of silver powder through glycerol process

    Indian Academy of Sciences (India)

    Amit Sinha; B P Sharma

    2005-06-01

    High purity fine silver powder with uniform particle morphology was prepared through glycerol process. The process involves reduction of silver nitrate by glycerol under atmospheric conditions at a temperature below 175°C. Glycerol, in this process, acts as a solvent as well as a reducing agent. The powders prepared through this process were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and chemical analysis. The powders were well crystalline and contained oxygen, carbon and hydrogen as impurities. Overall purity was better than 99.9%. The yield of silver powder was better than 99%.

  16. Ethanolysis of rapeseed oil - distribution of ethyl esters, glycerides and glycerol between ester and glycerol phases.

    Science.gov (United States)

    Cernoch, Michal; Hájek, Martin; Skopal, Frantisek

    2010-04-01

    The distribution of ethyl esters, triglycerides, diglycerides, monoglycerides, and glycerol between the ester and glycerol phase was investigated after the ethanolysis of rapeseed oil at various reaction conditions. The determination of these substances in the ester and glycerol phases was carried out by the GC method. The amount of ethyl esters in the glycerol phase was unexpectedly high and therefore the possibility of the reduction of this amount was investigated. The distribution coefficients and the weight distributions of each investigated substance were calculated and compared mutually. The distribution coefficients between the ester and glycerol phase increase in this sequence: glycerol, monoglycerides, diglycerides, ethyl esters, and triglycerides. Soaps and monoglycerides in the reaction mixture cause a worse separation of ethyl esters from the reaction mixture. The existence of a non-separable reaction mixture was observed also, and its composition was determined.

  17. Efficient green methanol synthesis from glycerol

    Science.gov (United States)

    Haider, Muhammad H.; Dummer, Nicholas F.; Knight, David W.; Jenkins, Robert L.; Howard, Mark; Moulijn, Jacob; Taylor, Stuart H.; Hutchings, Graham J.

    2015-12-01

    The production of biodiesel from the transesterification of plant-derived triglycerides with methanol has been commercialized extensively. Impure glycerol is obtained as a by-product at roughly one-tenth the mass of the biodiesel. Utilization of this crude glycerol is important in improving the viability of the overall process. Here we show that crude glycerol can be reacted with water over very simple basic or redox oxide catalysts to produce methanol in high yields, together with other useful chemicals, in a one-step low-pressure process. Our discovery opens up the possibility of recycling the crude glycerol produced during biodiesel manufacture. Furthermore, we show that molecules containing at least two hydroxyl groups can be converted into methanol, which demonstrates some aspects of the generality of this new chemistry.

  18. Valorization of crude glycerol from biodiesel production

    Directory of Open Access Journals (Sweden)

    Konstantinović Sandra S.

    2016-01-01

    Full Text Available The increased production of biodiesel as an alternative fuel involves the simultaneous growth in production of crude glycerol as its main by-product. Therefore, the feasibility and sustainability of biodiesel production requires the effective utilization of crude glycerol. This review describes various uses of crude glycerol as a potential green solvent for chemical reactions, a starting raw material for chemical and biochemical conversions into value-added chemicals, a substrate or co-substrate in microbial fermentations for synthesis of valuable chemicals and production of biogas and biohydrogen as well as a feedstuff for animal feed. A special attention is paid to various uses of crude glycerol in biodiesel production. [Projekat Ministarstva nauke Republike Srbije, br. III 45001

  19. Liquid dynamics in partially crystalline glycerol

    DEFF Research Database (Denmark)

    Sanz, Alejandro; Niss, Kristine

    2017-01-01

    We present a dielectric study on the dynamics of supercooled glycerol during crystallization. We explore the transformation into a solid phase in real time by monitoring the temporal evolution of the amplitude of the dielectric signal. Neither the initial nucleation nor the crystal growth......, we have found no evidence that supercooled glycerol transforms into a peculiar phase in which either a new solid amorphous state or nano-crystals dispersed in a liquid matrix are formed....

  20. Insoluble and flexible silk films containing glycerol.

    Science.gov (United States)

    Lu, Shenzhou; Wang, Xiaoqin; Lu, Qiang; Zhang, Xiaohui; Kluge, Jonathan A; Uppal, Neha; Omenetto, Fiorenzo; Kaplan, David L

    2010-01-11

    We directly prepared insoluble silk films by blending with glycerol and avoiding the use of organic solvents. The ability to blend a plasticizer like glycerol with a hydrophobic protein like silk and achieve stable material systems above a critical threshold of glycerol is an important new finding with importance for green chemistry approaches to new and more flexible silk-based biomaterials. The aqueous solubility, biocompatibility, and well-documented use of glycerol as a plasticizer with other biopolymers prompted its inclusion in silk fibroin solutions to assess impact on silk film behavior. Processing was performed in water rather than organic solvents to enhance the potential biocompatibility of these biomaterials. The films exhibited modified morphologies that could be controlled on the basis of the blend composition and also exhibited altered mechanical properties, such as improved elongation at break, when compared with pure silk fibroin films. Mechanistically, glycerol appears to replace water in silk fibroin chain hydration, resulting in the initial stabilization of helical structures in the films, as opposed to random coil or beta-sheet structures. The use of glycerol in combination with silk fibroin in materials processing expands the functional features attainable with this fibrous protein, and in particular, in the formation of more flexible films with potential utility in a range of biomaterial and device applications.

  1. Glycerol monooleate-blood interactions.

    Science.gov (United States)

    Ericsson, Emma M; Faxälv, Lars; Weissenrieder, Anna; Askendal, Agneta; Lindahl, Tomas L; Tengvall, Pentti

    2009-01-01

    In the present study the initial blood compatibility of glycerol monooleate (GMO)-coated surfaces was evaluated after deposition to surfaces and in bulk. The model surface was silica onto which multiple layers of fibrinogen or human serum albumin (HSA) was immobilized. The protein-coated surfaces were subsequently dip-coated in GMO in ethanol and used for blood plasma and whole blood experiments. The characterization methods included null ellipsometry, scanning electron microscopy, imaging of coagulation, hemolysis test and whole blood coagulation time by free oscillation rheometry. The results showed a GMO film thickness of approximately 350 A (approximately 4 microg/cm(2)) upon dip-coating in ethanolic solution. A major part of the deposited layer detached in aqueous solutions, especially during shear conditions. The coagulation time on GMO was significantly prolonged compared to that on HSA coated silica. Whole blood tests showed that GMO is a very weak hemolytic agent. Deposited GMO detached easily from surfaces upon rinsing or shearing, although a stable layer with undefined phase structure and a thickness of 50-70 A remained on HSA and fibrinogen precoated surfaces. This indicates that GMO has stronger adhesive forces to its substrate compared to the cohesive forces acting within the bulk GMO. The ability of GMO to detach from itself and tentatively form micelles or lipid bilayers when subjected to flowing blood may be of use in extravascular applications. It is concluded that GMO results in weak blood activation, and the material may in spite of this be suitable in selected biomaterial applications, especially as a biosealant and in colloidal dispersions.

  2. Searching for branched glycerol dialkyl glycerol tetraether membrane lipid producing bacteria in soil

    NARCIS (Netherlands)

    Aydin, R.

    2012-01-01

    KEYWORDS:Branched GDGTs, proxy, pH, temperature, Acidobacteria, methylotrophy, high-throughput techniques Bacteria present in soil and peat bog environments were previously found to produce branched glycerol dialkyl glycerol tetraether membrane lip

  3. The organic geochemistry of glycerol dialkyl glycerol tetraether lipids: A review

    NARCIS (Netherlands)

    Schouten, S.; Hopmans, E.C.; Sinninghe Damsté, J.S.

    2013-01-01

    Glycerol dialkyl glycerol tetraether (GDGT) lipids are membrane lipids which were long thought to be synthesized mainly by archaea, organisms thought to be limited to extreme environments. Analysis of environmental samples over the last decade has shown, however, that their structural diversity and

  4. Biogeochemical controls on glycerol dialkyl glycerol tetraether lipid distributions in sediments characterized by diffusive methane flux

    NARCIS (Netherlands)

    Weijers, J.W.H.; Lim, K.L.H.; Aquilina, A.; Sinninghe Damsté, J.S.; Pancost, R.D.

    2011-01-01

    The TEX86 (TetraEther indeX of tetraethers consisting of 86 carbon atoms) is a proxy for sea surface temperature (SST) based on the distribution of isoprenoidal glycerol dialkyl glycerol tetraether (GDGT) membrane lipids synthesized by marine pelagic Thaumarchaeota. One of the caveats of this

  5. Biogeochemical controls on glycerol dialkyl glycerol tetraether lipid distributions in sediments characterized by diffusive methane flux

    NARCIS (Netherlands)

    Weijers, J.W.H.; Lim, K.L.H.; Aquilina, A.; Sinninghe Damsté, J.S.; Pancost, R.D.

    2011-01-01

    The TEX(86) (TetraEther indeX of tetraethers consisting of 86 carbon atoms) is a proxy for sea surface temperature (SST) based on the distribution of isoprenoidal glycerol dialkyl glycerol tetraether (GDGT) membrane lipids synthesized by marine pelagic Thaumarchaeota. One of the caveats of this

  6. Catalytic glycerol steam reforming for hydrogen production

    Science.gov (United States)

    Dan, Monica; Mihet, Maria; Lazar, Mihaela D.

    2015-12-01

    Hydrogen production from glycerol by steam reforming combine two major advantages: (i) using glycerol as raw material add value to this by product of bio-diesel production which is obtained in large quantities around the world and have a very limited utilization now, and (ii) by implication of water molecules in the reaction the efficiency of hydrogen generation is increased as each mol of glycerol produces 7 mol of H2. In this work we present the results obtained in the process of steam reforming of glycerol on Ni/Al2O3. The catalyst was prepared by wet impregnation method and characterized through different methods: N2 adsorption-desorption, XRD, TPR. The catalytic study was performed in a stainless steel tubular reactor at atmospheric pressure by varying the reaction conditions: steam/carbon ratio (1-9), gas flow (35 ml/min -133 ml/min), temperature (450-650°C). The gaseous fraction of the reaction products contain: H2, CH4, CO, CO2. The optimum reaction conditions as resulted from this study are: temperature 550°C, Gly:H2O ratio 9:1 and Ar flow 133 ml/min. In these conditions the glycerol conversion to gaseous products was 43% and the hydrogen yield was 30%.

  7. Catalytic glycerol steam reforming for hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Dan, Monica, E-mail: monica.dan@itim-cj.ro; Mihet, Maria, E-mail: maria.mihet@itim-cj.ro; Lazar, Mihaela D., E-mail: diana.lazar@itim-cj.ro [National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat Street, 400293 Cluj Napoca (Romania)

    2015-12-23

    Hydrogen production from glycerol by steam reforming combine two major advantages: (i) using glycerol as raw material add value to this by product of bio-diesel production which is obtained in large quantities around the world and have a very limited utilization now, and (ii) by implication of water molecules in the reaction the efficiency of hydrogen generation is increased as each mol of glycerol produces 7 mol of H{sub 2}. In this work we present the results obtained in the process of steam reforming of glycerol on Ni/Al{sub 2}O{sub 3}. The catalyst was prepared by wet impregnation method and characterized through different methods: N{sub 2} adsorption-desorption, XRD, TPR. The catalytic study was performed in a stainless steel tubular reactor at atmospheric pressure by varying the reaction conditions: steam/carbon ratio (1-9), gas flow (35 ml/min -133 ml/min), temperature (450-650°C). The gaseous fraction of the reaction products contain: H{sub 2}, CH{sub 4}, CO, CO{sub 2}. The optimum reaction conditions as resulted from this study are: temperature 550°C, Gly:H{sub 2}O ratio 9:1 and Ar flow 133 ml/min. In these conditions the glycerol conversion to gaseous products was 43% and the hydrogen yield was 30%.

  8. The potential of glycerol in freezing preservation of turbine oil-degrading bacterial consortium and the ability of the revised consortium to degrade petroleum wastes

    OpenAIRE

    Kurachi, Kumiko; Hosokawa, Reia; Takahashi, Marina; Okuyama, Hidetoshi

    2014-01-01

    The turbine oil (TuO)-degrading bacterial consortium Tank-2 (original Tank-2) was preserved as a glycerol stock at -80 degrees C from 2009 to 2012. Storage methods have been unavailable so far for any TuO-degrading bacterial consortia or isolates. To evaluate the usefulness of glycerol stock, the original Tank-2 consortium frozen in glycerol at -80 degrees C was thawed and then revived by repeated culture in mineral salts medium (MSM) containing 0.5% (w/w) TuO (revived Tank-2). The revived Ta...

  9. Deployment Repeatability

    Science.gov (United States)

    2016-04-01

    controlled to great precision, but in a Cubesat , there may be no attitude determination at all. Such a Cubesat might treat sun angle and tumbling rates as...could be sensitive to small differences in motor controller timing. In these cases, the analyst might choose to model the entire deployment path, with...knowledge of the material damage model or motor controller timing precision. On the other hand, if many repeated and environmentally representative

  10. Tandem transformation of glycerol to esters.

    Science.gov (United States)

    Sotenko, Maria V; Rebroš, Martin; Sans, Victor S; Loponov, Konstantin N; Davidson, Matthew G; Stephens, Gill; Lapkin, Alexei A

    2012-12-31

    Tandem transformation of glycerol via microbial fermentation and enzymatic esterification is presented. The reaction can be performed with purified waste glycerol from biodiesel production in a continuous mode, combining continuous fermentation with membrane-supported enzymatic esterification. Continuous anaerobic fermentation was optimized resulting in the productivity of 2.4 g L⁻¹ h⁻¹ of 1,3-propanediol. Biphasic esterification of 1,3-propanediol was optimized to achieve ester yield of up to 75%. A hollow fibre membrane contactor with immobilized Rhizomucor miehei lipase was demonstrated for the continuous tandem fermentation-esterification process.

  11. Genetic construction of recombinant Pseudomonas chlororaphis for improved glycerol utilization

    Science.gov (United States)

    The objective of this study is to improve by genetic engineering the glycerol metabolic capability of Pseudomonas chlororaphis which is capable of producing commercially valuable biodegradable poly(hydroxyalkanoate) (PHA) and biosurfactant rhamnolipids (RLs). In the study, glycerol uptake facilitat...

  12. Glycerol hypersensitivity in a Drosophila model for glycerol kinase deficiency is affected by mutations in eye pigmentation genes.

    Directory of Open Access Journals (Sweden)

    Patrick J Wightman

    Full Text Available Glycerol kinase plays a critical role in metabolism by converting glycerol to glycerol 3-phosphate in an ATP dependent reaction. In humans, glycerol kinase deficiency results in a wide range of phenotypic variability; patients can have severe metabolic and CNS abnormalities, while others possess hyperglycerolemia and glyceroluria with no other apparent phenotype. In an effort to help understand the pathogenic mechanisms underlying the phenotypic variation, we have created a Drosophila model for glycerol kinase deficiency by RNAi targeting of dGyk (CG18374 and dGK (CG7995. As expected, RNAi flies have reduced glycerol kinase RNA expression, reduced phosphorylation activity and elevated glycerol levels. Further investigation revealed these flies to be hypersensitive to fly food supplemented with glycerol. Due to the hygroscopic nature of glycerol, we predict glycerol hypersensitivity is a result of greater susceptibility to desiccation, suggesting glycerol kinase to play an important role in desiccation resistance in insects. To evaluate a role for genetic modifier loci in determining severity of the glycerol hypersensitivity observed in knockdown flies, we performed a preliminary screen of lethal transposon insertion mutant flies using a glycerol hypersensitive survivorship assay. We demonstrate that this type of screen can identify both enhancer and suppressor genetic loci of glycerol hypersensitivity. Furthermore, we found that the glycerol hypersensitivity phenotype can be enhanced or suppressed by null mutations in eye pigmentation genes. Taken together, our data suggest proteins encoded by eye pigmentation genes play an important role in desiccation resistance and that eye pigmentation genes are strong modifiers of the glycerol hypersensitive phenotype identified in our Drosophila model for glycerol kinase deficiency.

  13. 21 CFR 172.735 - Glycerol ester of rosin.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Glycerol ester of rosin. 172.735 Section 172.735 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD... CONSUMPTION Other Specific Usage Additives § 172.735 Glycerol ester of rosin. Glycerol ester of wood...

  14. Glycerol utilization: solvent-free acetalisation over niobia catalysts

    NARCIS (Netherlands)

    Nair, G. S.; Adrijanto, E.; Alsalme, A.; Kozhevnikov, I. V.; Cooke, D. J.; Brown, D.R.; Shiju, N.R.

    2012-01-01

    With increasing biodiesel production, availability of glycerol is expected to increase. New processes are needed for converting this surplus glycerol to value-added chemicals. In this work, we used niobia catalysts for the liquid-phase acetalisation of glycerol without using any solvent. High conver

  15. 75 FR 71556 - Polyoxyalkylated Glycerol Fatty Acid Esters; Tolerance Exemption

    Science.gov (United States)

    2010-11-24

    ... AGENCY 40 CFR Part 180 Polyoxyalkylated Glycerol Fatty Acid Esters; Tolerance Exemption AGENCY... from the requirement of a tolerance for residues of polyoxyalkylated glycerol fatty acid esters; the... ethylene oxide or propylene oxide, also known as polyoxyalkylated glycerol fatty acid esters, when used as...

  16. Determining Atmospheric Pressure with a Eudiometer and Glycerol

    Science.gov (United States)

    Brody, Jed; Rohald, Kate; Sutton, Atasha

    2010-01-01

    We consider a volume of air trapped over a glycerol column in a eudiometer. We demonstrate that there is an approximately linear relationship between the volume of trapped air and the height of the glycerol column. Simply by moving the eudiometer up and down, we cause the glycerol-column height and trapped-air volume to vary. The plot of volume…

  17. METHYLENE BLUE ADSORPTION FROM GLYCEROL SOLUTION ...

    African Journals Online (AJOL)

    Preferred Customer

    The recognition of the presence of two habits of goethite was indicated by ... In order to use the above formula (equation 1), it is necessary to know the value of ... On the basis of which log of fractional coverage, W (x/m) was related with log ..... Composite isotherms for the system MB/glycerol adsorbed onto acicular habit at.

  18. Delignification of biomass using alkaline glycerol

    Energy Technology Data Exchange (ETDEWEB)

    Kucuk, M. [YYU Educational Facility, Van (Turkey)

    2005-10-15

    Ailanthus altissima and Spruce orientalis chips were delignified by using glycerol as a solvent and alkaline-gliycerol with and without catalyst at different temperatures (438, 458, 478, and 498 K) in atmospheric pressure, and results were compared with the other organic solvent systems. (Author)

  19. Conversion of glycerol to hydrogen rich gas.

    Science.gov (United States)

    Tran, Nguyen H; Kannangara, G S Kamali

    2013-12-21

    Presently there is a glut of glycerol as the by-product of biofuel production and it will grow as production increases. The conundrum is how we can consume this material and convert it into a more useful product. One potential route is to reform glycerol to hydrogen rich gas including synthesis gas (CO + H2) and hydrogen. However, there is recent literature on various reforming techniques which may have a bearing on the efficiency of such a process. Hence in this review reforming of glycerol at room temperature (normally photo-catalytic), catalysis at moderate and high temperature and a non-catalytic pyrolysis process are presented. The high temperature processes allow the generation of synthesis gas with the hydrogen to carbon monoxide ratios being suitable for synthesis of dimethyl ether, methanol and for the Fischer-Tropsch process using established catalysts. Efficient conversion of synthesis gas to hydrogen involves additional catalysts that assist the water gas shift reaction, or involves in situ capture of carbon dioxide and hydrogen. Reforming at reduced temperatures including photo-reforming offers the opportunity of producing synthesis gas or hydrogen using single catalysts. Together, these processes will assist in overcoming the worldwide glut of glycerol, increasing the competitiveness of the biofuel production and reducing our dependency on the fossil based, hydrogen rich gas.

  20. Synthesis of glycerol mono-laurate from lauric acid and glycerol for food antibacterial additive

    Science.gov (United States)

    Setianto, W. B.; Wibowo, T. Y.; Yohanes, H.; Illaningtyas, F.; Anggoro, D. D.

    2017-05-01

    Synthesis of glycerol mono-laurate (GML) has been performed using esterification reaction of glycerol and lauric acid. The reaction was performed at the condition of temperature of 120-140 °C within 7 hour, variation of molar ratio of glycerol - lauric acid, and was using heterogeneous catalyst of zeolist Y. Without catalyst dealumination the maximum acid conversion was 78%, with GML contained in the sample was 38.6%, and it was obtained at the reaction condition of 140 oC, 15wt% catalyst, and 8:1 molar ratio of glycerol - lauric acid. At the same condition, using dealuminated catalyst, the maximum acid conversion was increased up to 98%, with GML contained in the sample was 50.4%. The GML antibacterial activity was examined. It was observed that the GML has antibacterial activity against gram positive bacterial such as B. cereus and S. aureus.

  1. Competitive inhibition of AQP7-mediated glycerol transport by glycerol derivatives.

    Science.gov (United States)

    Katano, Takahiro; Ito, Yuko; Ohta, Kinya; Yasujima, Tomoya; Inoue, Katsuhisa; Yuasa, Hiroaki

    2014-01-01

    Aquaporin 7 (AQP7) is an aquaglyceroporin that has recently been found to operate as a facilitative carrier rather than a channel for glycerol, although its primary function is as a water channel. To probe into its substrate specificity, we examined the inhibitory effect of a series of acyl glycerol derivatives on glycerol transport mediated by human AQP7 stably expressed in Madin-Darby canine kidney II cells. According to kinetic analyses, AQP7-mediated glycerol transport was found to be competitively inhibited by monoacetin, monobutyrin and diacetin. Therefore, it may be possible that they all could be recognized as substrates by AQP7. The inhibition constant (Ki) of monoacetin (134 µM) was smaller than that of diacetin (420 µM), but greater than the Michaelis constant for glycerol (11.8 µM). Considering another finding that inhibition by triacetin was insignificant, it is likely that a decrease in the number of hydroxyl groups in the glycerol molecule by acetyl derivatization leads to a decrease in affinity for AQP7. The Ki of monobutyrin (80 µM) was, on the other hand, comparable with that of monoacetin, suggesting that the extension of the acyl chain by two hydrocarbon units does not have an impact on affinity for AQP7.

  2. Bioconversion technologies of crude glycerol to value added industrial products

    Directory of Open Access Journals (Sweden)

    Vijay Kumar Garlapati

    2016-03-01

    Full Text Available Crude glycerol that is produced as the by-product from biodiesel, has to be effectively utilized to contribute to the viability of biodiesel. Crude glycerol in large amounts can pose a threat to the environment. Therefore, there is a need to convert this crude glycerol into valued added products using biotechnological processes, which brings new revenue to biodiesel producers. Crude glycerol can serve as a feedstock for biopolymers, poly unsaturated fatty acids, ethanol, hydrogen and n-butanol production and as a raw material for different value added industrial products. Hence, in this review we have presented different bioconversion technologies of glycerol to value added industrial products.

  3. Glycerol from biodiesel production: the new corn for dairy cattle

    Directory of Open Access Journals (Sweden)

    Shawn S Donkin

    2008-07-01

    Full Text Available Glycerol, also known as glycerin, is a colorless, odorless, hygroscopic, and sweet-tasting viscous liquid. It is a sugar alcohol with high solubility index in water and has a wide range of applications in the food, pharmaceutical, and cosmetic industries. The use of glycerol in diets for dairy cattle is not novel; however, this interest has been renewed due to the increased availability and favorable pricing of glycerol as a consequence of recent growth in the biofuels industry. Experimental evidence supports the use of glycerol as a transition cow therapy but feeding rates are low, ranging from 5 to 8 % of the diet DM. There is a paucity of research that examines the use of glycerol as a macro-ingredient in rations for lactating dairy cows. Most reports indicate a lack of effect of addition of glycerol to the diet when it replaces corn or corn starch. Recent feeding experiments with lactating dairy cows indicate replacing corn with glycerol to a level of 15% of the ration DM does not adversely effect milk production or composition. Milk production was 37.0, 36.9, 37.3, 36.4 ± 0.6 kg/d and feed intake was 24.0, 24.5, 24.6, 24.1 ± 0.5 kg/d for 0, 5, 10 and 15% glycerol treatments respectively and did not differ (P > 0.05 except for a modest reduction in feed intake during the first 7 days for the 15% glycerol treatment. Glycerol fed to dairy cattle is fermented to volatile fatty acids in the rumen and early reports indicated that glycerol is almost entirely fermented to propionate. In vitro data indicates glycerol fermentation increases the production of propionate and butyrate at the expense of acetate. Rumen microbes appear to adapt to glycerol feeding and consequently, cows fed glycerol also require an adaptation period to glycerol inclusion. Debate exists regarding the fate of glycerol in the rumen and although most reports suggest that glycerol is largely fermented in the rumen, the extent of rumen digestion may depend on level of

  4. An improved glycerol biosensor with an Au-FeS-NAD-glycerol-dehydrogenase anode.

    Science.gov (United States)

    Mahadevan, Aishwarya; Fernando, Sandun

    2017-06-15

    An improved glycerol biosensor was developed via direct attachment of NAD(+)-glycerol dehydrogenase coenzyme-apoenzyme complex onto supporting gold electrodes, using novel inorganic iron (II) sulfide (FeS)-based single molecular wires. Sensing performance factors, i.e., sensitivity, a detection limit and response time of the FeS and conventional pyrroloquinoline quinone (PQQ)-based biosensor were evaluated by dynamic constant potential amperometry at 1.3V under non-buffered conditions. For glycerol concentrations ranging from 1 to 25mM, a 77% increase in sensitivity and a 53% decrease in detection limit were observed for the FeS-based biosensor when compared to the conventional PQQ-based counterpart. The electrochemical behavior of the FeS-based glycerol biosensor was analyzed at different concentrations of glycerol, accompanied by an investigation into the effects of applied potential and scan rate on the current response. Effects of enzyme stimulants ((NH4)2SO4 and MnCl2·4H2O) concentrations and buffers/pH (potassium phosphate buffer pH 6-8, Tris buffer pH 8-10) on the current responses generated by the FeS-based glycerol biosensor were also studied. The optimal detection conditions were 0.03M (NH4)2SO4 and 0.3µm MnCl2·4H2O in non-buffered aqueous electrolyte under stirring whereas under non-stirring, Tris buffer at pH 10 with 0.03M (NH4)2SO4 and 30µm MnCl2·4H2O were found to be optimal detection conditions. Interference by glucose, fructose, ethanol, and acetic acid in glycerol detection was studied. The observations indicated a promising enhancement in glycerol detection using the novel FeS-based glycerol sensing electrode compared to the conventional PQQ-based one. These findings support the premise that FeS-based bioanodes are capable of biosensing glycerol successfully and may be applicable for other enzymatic biosensors.

  5. Taxonomic diversity of anaerobic glycerol dissimilation in the Enterobacteriaceae.

    Science.gov (United States)

    Bouvet, O M; Lenormand, P; Ageron, E; Grimont, P A

    1995-05-01

    A total of 1,123 strains representing 128 taxa in the Enterobacteriaceae (named species or subspecies and genomic species) were screened for the presence of glycerol dehydrogenases and 1,3-propanediol dehydrogenase. Only eight taxa, Citrobacter freundii sensu stricto, C. youngae, C. braakii, C. werkmanii, Citrobacter genomospecies 10 and 11, Enterobacter gergoviae and Klebsiella pneumoniae subsp. pneumoniae could grow fermentatively on glycerol and possessed both glycerol dehydrogenase type I (induced by glycerol and dihydroxyacetone) and 1,3-propanediol dehydrogenase which are typical enzymes of the anaerobic glycerol dissimilation pathway. Six other species, C. koseri, E. aerogenes, E. intermedium, K. oxytoca, K. planticola and K. terrigena could not grow fermentatively on glycerol and possessed a glycerol dehydrogenase type I but no 1,3-propanediol dehydrogenase. Other glycerol dehydrogenases types were found: type II (induced by glycerol and hydroxyacetone), type III (induced by glycerol only) and type IV (induced by hydroxyacetone only). They were widely distributed among the Enterobacteriaceae. Classification and identification may take advantage of tests exploring the dissimilation of glycerol.

  6. Stimulation of insulin secretion in man by oral glycerol administration.

    Science.gov (United States)

    Zanoboni, A; Schwarz, D; Zanoboni-Muciaccia, W

    1976-01-01

    The effects of an orally administered glycerol load (1 g/Kg body weight) on blood glucose, plasma FFA, and plasma insulin levels have been determined in eight normal fasting or glucose loaded (1 g/Kg body weight) volunteers. Blood glucose levels were not affected by glycerol loading while glicemia followed the same pattern of a glucose tolerance test in the group treated with glucose plus glycerol. Plasma FFA were significantly lowered only 90 min after glycerol loading while they had markedly and persistently decreased by glycerol plus glucose per os. Finally, though glicemia did not change, insulinemia was markedly increased by glycereol, 90 min after loading; moreover, plasma IRI was significantly higher in the group treated with glycerol plus glucose than in the group treated with glucose alone. These data suggest that the release of insulin may be stimulated by a very small increment of blood glucose, which derives from glycerol.

  7. "Fulfilling the chief of his duties as a physician": Harvey Cushing, selective dorsal rhizotomy and elective spine surgery for quality of life.

    Science.gov (United States)

    Dasenbrock, Hormuzdiyar H; Pendleton, Courtney; McGirt, Matthew J; Sciubba, Daniel M; Gokaslan, Ziya L; Quiñones-Hinojosa, Alfredo; Bydon, Ali

    2011-03-01

    At the beginning of the 20th century, the development of safer anesthesia, antiseptic techniques, and meticulous surgical dissection led to a substantial decrease in operative risk. In turn, the scope of surgery expanded to include elective procedures performed with the intention of improving the quality of life of patients. Between 1908 and 1912, Harvey Cushing performed 3 dorsal rhizotomies to improve the quality of life of 3 patients with debilitating neuralgia: a 54-year-old man with "lightning" radicular pain from tabes dorsalis, a 12-year-old boy cutaneous hyperesthesia and spasticity in his hemiplegic arm, and a 61-year-old man with postamputation neuropathic pain. Symptomatic improvement was seen postoperatively in the first 2 cases, although the third patient continued to have severe pain. Cushing also removed a prominent spinous process from each of 2 patients with debilitating headaches; both patients, however, experienced only minimal postoperative improvement. These cases, which have not been previously published, highlight Cushing's views on the role of surgery and illustrate the broader movement that occurred in surgery at the time, whereby elective procedures for quality of life became performed and accepted.

  8. “Fulfilling the chief of his duties as a physician”: Harvey Cushing, selective dorsal rhizotomy and elective spine surgery for quality of life

    Science.gov (United States)

    Dasenbrock, Hormuzdiyar H.; Pendleton, Courtney; McGirt, Matthew J.; Sciubba, Daniel M.; Gokaslan, Ziya L.; Quiñones-Hinojosa, Alfredo; Bydon, Ali

    2015-01-01

    At the beginning of the 20th century, the development of safer anesthesia, antiseptic techniques, and meticulous surgical dissection led to a substantial decrease in operative risk. In turn, the scope of surgery expanded to include elective procedures performed with the intention of improving the quality of life of patients. Between 1908 and 1912, Harvey Cushing performed 3 dorsal rhizotomies to improve the quality of life of 3 patients with debilitating neuralgia: a 54-year-old man with “lightning” radicular pain from tabes dorsalis, a 12-year-old boy cutaneous hyperesthesia and spasticity in his hemiplegic arm, and a 61-year-old man with postamputation neuropathic pain. Symptomatic improvement was seen postoperatively in the first 2 cases, although the third patient continued to have severe pain. Cushing also removed a prominent spinous process from each of 2 patients with debilitating headaches; both patients, however, experienced only minimal postoperative improvement. These cases, which have not been previously published, highlight Cushing's views on the role of surgery and illustrate the broader movement that occurred in surgery at the time, whereby elective procedures for quality of life became performed and accepted. PMID:21250816

  9. 选择性脊神经前、后根切断与下肢Ⅱ期矫形联合治疗儿童重型脑性瘫痪%Combination of selective anterior and posterior rhizotomy with orthomorphy stage Ⅱ in treating severe cerebral palsy in children

    Institute of Scientific and Technical Information of China (English)

    彭仲双; 李树民; 尹庆水; 权日; 郑伟雄; 叶为华; 周军

    2002-01-01

    Objective To study the general design and practice instages of the treatment of severe cerebral palsy with the combination of selective anterior and posterior rhizotomy with orthomorphy stage II of the lower extremities. Method To evaluate the disability of the cases, calculate the expectant value and design rehabilitation program in stages before selective anterior and posterior rhizotomy orthomorphy, force line recovering , extremities banlancing, joints stabilization and muscle force rebuilding. Result After treatment in stages the 15 children of cerebral palsy could walk without support. Conclusion It's most important to practice the combination of the operations in order in rehabilitation of children's severe cerebral palsy.

  10. Glycerol metabolism promotes biofilm formation by Pseudomonas aeruginosa.

    Science.gov (United States)

    Scoffield, Jessica; Silo-Suh, Laura

    2016-08-01

    Pseudomonas aeruginosa causes persistent infections in the airways of cystic fibrosis (CF) patients. Airway sputum contains various host-derived nutrients that can be utilized by P. aeruginosa, including phosphotidylcholine, a major component of host cell membranes. Phosphotidylcholine can be degraded by P. aeruginosa to glycerol and fatty acids to increase the availability of glycerol in the CF lung. In this study, we explored the role that glycerol metabolism plays in biofilm formation by P. aeruginosa. We report that glycerol metabolism promotes biofilm formation by both a chronic CF isolate (FRD1) and a wound isolate (PAO1) of P. aeruginosa. Moreover, loss of the GlpR regulator, which represses the expression of genes involved in glycerol metabolism, enhances biofilm formation in FRD1 through the upregulation of Pel polysaccharide. Taken together, our results suggest that glycerol metabolism may be a key factor that contributes to P. aeruginosa persistence by promoting biofilm formation.

  11. Anaerobic digestion of pig manure and glycerol from biodiesel production

    Directory of Open Access Journals (Sweden)

    Pakamas Chetpattananondh, Sumate Chaiprapat, Chaisri Suksaroj

    2015-01-01

    Full Text Available Increasing biodiesel production causes a surplus of glycerol. This work aims to investigate the crude glycerol pretreatment method and then apply the glycerol as a co-substrate with pig manure for anaerobic digestion. The optimum crude glycerol pretreatment method was acidification with 6% of H2SO4 that highest glycerol recovery was obtained with lowest cost. Co-digestions of glycerol and pig manure enhanced biogas and methane productions compared with mono-digestions. Biogas and methane productions in semi-continuous digestions were highly effected by OLR. The optimum OLR was 3.06 kg SCOD/m3 that biogas production was maintained at 3 L/d with methane composition of 72% and SCOD removal higher than 80%.

  12. Fungal biotransformation of crude glycerol into malic acid.

    Science.gov (United States)

    West, Thomas P

    2015-01-01

    Malic acid production from the biodiesel coproduct crude glycerol by Aspergillus niger ATCC 9142, ATCC 10577 and ATCC 12846 was observed to occur with the highest malic acid level acid being produced by A. niger ATCC 12846. Fungal biomass production from crude glycerol was similar, but ATCC 10577 produced the highest biomass. Fungal biotransformation of crude glycerol into the commercially valuable organic acid malic acid appeared feasible.

  13. Ruminal fermentation of propylene glycol and glycerol.

    Science.gov (United States)

    Trabue, Steven; Scoggin, Kenwood; Tjandrakusuma, Siska; Rasmussen, Mark A; Reilly, Peter J

    2007-08-22

    Bovine rumen fluid was fermented anaerobically with 25 mM R-propylene glycol, S-propylene glycol, or glycerol added. After 24 h, all of the propylene glycol enantiomers and approximately 80% of the glycerol were metabolized. Acetate, propionate, butyrate, valerate, and caproate concentrations, in decreasing order, all increased with incubation time. Addition of any of the three substrates somewhat decreased acetate formation, while addition of either propylene glycol increased propionate formation but decreased that of butyrate. R- and S-propylene glycol did not differ significantly in either their rates of disappearance or the products formed when they were added to the fermentation medium. Fermentations of rumen fluid containing propylene glycol emitted the sulfur-containing gases 1-propanethiol, 1-(methylthio)propane, methylthiirane, 2,4-dimethylthiophene, 1-(methylthio)-1-propanethiol, dipropyl disulfide, 1-(propylthio)-1-propanethiol, dipropyl trisulfide, 3,5-diethyl-1,2,4-trithiolane, 2-ethyl-1,3-dithiane, and 2,4,6-triethyl-1,3,5-trithiane. Metabolic pathways that yield each of these gases are proposed. The sulfur-containing gases produced during propylene glycol fermentation in the rumen may contribute to the toxic effects seen in cattle when high doses are administered for therapeutic purposes.

  14. Fabrication of a glycerol from CO2 reaction system, supplement

    Science.gov (United States)

    Weiss, A. H.

    1973-01-01

    The fabrication, installation, and testing of a glycerol hydrogenation and a CO2 hydrogenation - CH4 partial oxidation units are reported. The glycerol system proved to be operational while the CO2 system was installed but not bought on operational steam.

  15. Single crystals of V Amylose complexed with glycerol

    NARCIS (Netherlands)

    Hulleman, S.H.D.; Helbert, W.; Chanzy, H.

    1996-01-01

    Lamellar single crystals of amylose V glycerol were grown at 100°C by evaporating water from solutions of amylose in aqueous glycerol. The crystals which were square, with lateral dimensions of several micrometers, gave sharp electron diffraction patterns presenting an orthorhombic symmetry with a p

  16. Thermal and Structural Properties of Silk Biomaterials Plasticized by Glycerol.

    Science.gov (United States)

    Brown, Joseph E; Davidowski, Stephen K; Xu, Dian; Cebe, Peggy; Onofrei, David; Holland, Gregory P; Kaplan, David L

    2016-12-12

    The molecular interactions of silk materials plasticized using glycerol were studied, as these materials provide options for biodegradable and flexible protein-based systems. Plasticizer interactions with silk were analyzed by thermal, spectroscopic, and solid-state NMR analyses. Spectroscopic analysis implied that glycerol was hydrogen bonded to the peptide matrix, but may be displaced with polar solvents. Solid-state NMR indicated that glycerol induced β-sheet formation in the dried silk materials, but not to the extent of methanol treatment. Fast scanning calorimetry suggested that β-sheet crystal formation in silk-glycerol films appeared to be less organized than in the methanol treated silk films. We propose that glycerol may be simultaneously inducing and interfering with β-sheet formation in silk materials, causing some improper folding that results in less-organized silk II structures even after the glycerol is removed. This difference, along with trace residual glycerol, allows glycerol extracted silk materials to retain more flexibility than methanol processed versions.

  17. Microbial community engineering for biopolymer production from glycerol

    NARCIS (Netherlands)

    Moralejo-Gárate, H.; Mar'atusalihat, E.; Kleerebezem, R.; Van Loosdrecht, M.C.M.

    2011-01-01

    In this work, the potential of using microbial community engineering for production of polyhydroxyalkanoates (PHA) from glycerol was explored. Crude glycerol is a by-product of the biofuel (biodiesel and bioethanol) industry and potentially a good substrate for bioplastic production. A PHA-producing

  18. Microbial community engineering for biopolymer production from glycerol

    NARCIS (Netherlands)

    Moralejo-Gárate, H.; Mar'atusalihat, E.; Kleerebezem, R.; Van Loosdrecht, M.C.M.

    2011-01-01

    In this work, the potential of using microbial community engineering for production of polyhydroxyalkanoates (PHA) from glycerol was explored. Crude glycerol is a by-product of the biofuel (biodiesel and bioethanol) industry and potentially a good substrate for bioplastic production. A PHA-producing

  19. Synthesis and applications of {sup 13}C glycerol

    Energy Technology Data Exchange (ETDEWEB)

    Stocking, E.; Khalsa, O.; Martinez, R.A.; Silks, L.A. III [Los Alamos National Laboratory, NM (United States)

    1994-12-01

    Due in part to the use of labeled glycerol for the {sup 13}C enrichment of biomolecules, we are currently developing new synthetic routes to various isotopomers of glycerol. Judging from our experience, traditional methods of glycerol synthesis are not easily adapted for isotopic enrichment and/or have poor overall yields (12 to 15%). Furthermore, the use of glycerol for enrichment can be prohibitively expensive and its availability is limited by the level of demand. We are presently developing a short de novo synthesis of glycerol from carbon dioxide ({approximately}53% overall yield for four steps) and are examining the feasibility of synthesizing site-specific {sup 13}C-labeled glycerol and dihydroxyacetone (DHA) from labeled methanol and carbon dioxide. One application of {sup 13}C glycerol we have examined is enzymatic conversion of glycerol to glyceraldehyde-3-monophosphate or dihydroxyacetone monophosphate (DHAP) with yields ranging from 25 to 50% (as determined by NMR spectroscopy). We are also pursuing the chemical conversion of {sup 13}C-labeled DHA to DHAP. We are especially interested in {sup 13}C-labeled DHAP because we are investigating its use as a chemo-enzymatic precursor for both labeled 2-deoxyribose and 2-deoxyribonucleic acids.

  20. Influence of glycerol on the melting of potato starch

    NARCIS (Netherlands)

    Vliegenthart, J.F.G.; Soest, J.J.G. van; Bezemer, R.C.; Wit, D. de

    1996-01-01

    The gelatinization and melting of granular and recrystallized starch have been studied in the presence of low and high levels of glycerol or water by differential scanning calorimetry. The gelatinization onset temperature is increased in the presence of glycerol, whereas the excess gelatinization

  1. Glycerol reforming in supercritical water : a short review

    NARCIS (Netherlands)

    Markocic, Elena; Kramberger, Boris; van Bennekom, Joost G.; Heeres, Hero Jan; Vos, John; Knez, Zeljko; Markočič, Elena; Knez, Željko

    2013-01-01

    Due to the rise in global biodiesel production, the amount of crude glycerol, the main byproduct, has increased steadily. Identification of high value added outlets for crude glycerol has been explored in detail to increase the overall economics of the biodiesel process. Examples are the use of glyc

  2. Influence of glycerol on the melting of potato starch

    NARCIS (Netherlands)

    Soest, van J.J.G.; Bezemer, R.C.; Wit, de D.; Viiegenthart, J.F.G.

    1996-01-01

    The gelatinization and melting of granular and recrystallized starch have been studied in the presence of low and high levels of glycerol or water by differential scanning calorimetry. The gelatinization onset temperature is increased in the presence of glycerol, whereas the excess gelantinization

  3. Investigation of glycerol assimilation and cofactor metabolism in Lactococcus lactis

    DEFF Research Database (Denmark)

    Holm, Anders Koefoed

    The production of biodiesel has been steadily increasing during the last decade, and with it crude glycerol as a byproduct. Despite being rich in glycerol, the increased supply has saturated the demand for glycerol, making purification a non-viable option. The background for this project was to i......The production of biodiesel has been steadily increasing during the last decade, and with it crude glycerol as a byproduct. Despite being rich in glycerol, the increased supply has saturated the demand for glycerol, making purification a non-viable option. The background for this project...... the technological requirements for the GLYFINERY processes. These have been included in the appendix (section A). The screening did not reveal any L. lactis strains capable of assimilating glycerol nor did it reveal any conditions favorable to glycerol dissimilation in L. lactis. The conditions evaluated were...... effects and improve the growth rate, though not completely to the level of the reference strain. The fact that this effect was predominantly observed while utilizing xylose implicates the involvement of the pentose phosphate pathway. A possible mechanism underlying the observed growth characteristics...

  4. Bioconversion of crude glycerol feedstocks into ethanol by Pachysolen tannophilus

    DEFF Research Database (Denmark)

    Liu, Xiaoying; Jensen, Peter Ruhdal; Workman, Mhairi

    2012-01-01

    Glycerol, the by-product of biodiesel production, is considered as a waste by biodiesel producers. This study demonstrated the potential of utilising the glycerol surplus through conversion to ethanol by the yeast Pachysolen tannophilus (CBS4044). This study demonstrates a robust bioprocess which...... was not sensitive to the batch variability in crude glycerol dependent on raw materials used for biodiesel production. The oxygen transfer rate (OTR) was a key factor for ethanol production, with lower OTR having a positive effect on ethanol production. The highest ethanol production was 17.5 g/L on 5% (v/v) crude...... glycerol, corresponding to 56% of the theoretical yield. A staged batch process achieved 28.1 g/L ethanol, the maximum achieved so far for conversion of glycerol to ethanol in a microbial bioprocess. The fermentation physiology has been investigated as a means to designing a competitive bioethanol...

  5. Glycerol dialkyl glycerol tetraether membrane lipids in lacustrine environments and their application as proxies for palaeoclimate reconstructions. Geologica Ultraiectina (322)

    NARCIS (Netherlands)

    Blaga, C.I.

    2010-01-01

    Lacustrine sediments often contain relatively high amounts of organic matter because of limited bottom water oxygenation and relatively high sedimentation rates. The membrane lipids of Crenarchaeota, a major group of the domain Archaea, consist of isoprenoid glycerol dialkyl glycerol tetraether (GDG

  6. Design and analysis of biorefineries based on raw glycerol: addressing the glycerol problem.

    Science.gov (United States)

    Posada, John A; Rincón, Luis E; Cardona, Carlos A

    2012-05-01

    Glycerol as a low-cost by-product of the biodiesel industry can be considered a renewable building block for biorefineries. In this work, the conversion of raw glycerol to nine added-value products obtained by chemical (syn-gas, acrolein, and 1,2-propanediol) or bio-chemical (ethanol, 1,3-propanediol, d-lactic acid, succinic acid, propionic acid, and poly-3-hydroxybutyrate) routes were considered. The technological schemes for these synthesis routes were designed, simulated, and economically assessed using Aspen Plus and Aspen Icarus Process Evaluator, respectively. The techno-economic potential of a glycerol-based biorefinery system for the production of fuels, chemicals, and plastics was analyzed using the commercial Commercial Sale Price/Production Cost ratio criteria, under different production scenarios. More income can be earned from 1,3-propanediol and 1,2-propanediol production, while less income would be obtained from hydrogen and succinic acid. This analysis may be useful mainly for biodiesel producers since several profitable alternatives are presented and discussed.

  7. The fate of glycerol entering the rumen of dairy cows and sheep.

    Science.gov (United States)

    Werner Omazic, A; Kronqvist, C; Zhongyan, L; Martens, H; Holtenius, K

    2015-04-01

    This study investigated the fate of glycerol entering the rumen, in particular whether glycerol could be absorbed across the rumen epithelium. Three non-lactating rumen-fistulated cows were used to calculate the overall disappearance rate of glycerol in vivo and evaluate the rate of ruminal glycerol absorption. Rumen epithelial tissues isolated from sheep were used to characterise glycerol transport properties. The rate of rumen microbial degradation of glycerol was then studied in an in vitro system under anaerobic and thermo-regulated conditions. The results showed that glycerol can be absorbed from the rumen in significant amounts. The fractional rate of absorption of glycerol was not affected by variations in glycerol concentration in the buffer solution in the in vivo study. The glycerol absorption apparently occurred largely by passive diffusion and was probably not facilitated by carriers. Glycerol also disappeared via microbial digestion and outflow from the rumen through the omasal orifice.

  8. Repeat-until-success quantum repeaters

    Science.gov (United States)

    Bruschi, David Edward; Barlow, Thomas M.; Razavi, Mohsen; Beige, Almut

    2014-09-01

    We propose a repeat-until-success protocol to improve the performance of probabilistic quantum repeaters. Conventionally, these rely on passive static linear-optics elements and photodetectors to perform Bell-state measurements (BSMs) with a maximum success rate of 50%. This is a strong impediment for entanglement swapping between distant quantum memories. Every time a BSM fails, entanglement needs to be redistributed between the corresponding memories in the repeater link. The key ingredients of our scheme are repeatable BSMs. Under ideal conditions, these turn probabilistic quantum repeaters into deterministic ones. Under realistic conditions, our protocol too might fail. However, using additional threshold detectors now allows us to improve the entanglement generation rate by almost orders of magnitude, at a nominal distance of 1000 km, compared to schemes that rely on conventional BSMs. This improvement is sufficient to make the performance of our scheme comparable to the expected performance of some deterministic quantum repeaters.

  9. Glycerol inhibits water permeation through Plasmodium falciparum aquaglyceroporin.

    Science.gov (United States)

    Chen, Liao Y

    2013-01-01

    Plasmodium falciparum aquaglyceroporin (PfAQP) is a multifunctional membrane protein in the plasma membrane of P. falciparum, the parasite that causes the most severe form of malaria. The current literature has established the science of PfAQP's structure, functions, and hydrogen-bonding interactions but left unanswered the following fundamental question: does glycerol modulate water permeation through aquaglyceroporin that conducts both glycerol and water? This paper provides an affirmative answer to this question of essential importance to the protein's functions. On the basis of the chemical-potential profile of glycerol from the extracellular bulk region, throughout PfAQP's conducting channel, to the cytoplasmic bulk region, this study shows the existence of a bound state of glycerol inside aquaglyceroporin's permeation pore, from which the dissociation constant is approximately 14μM. A glycerol molecule occupying the bound state occludes the conducting pore through which permeating molecules line up in single file by hydrogen-bonding with one another and with the luminal residues of aquaglyceroporin. In this way, glycerol inhibits permeation of water and other permeants through aquaglyceroporin. The biological implications of this theory are discussed and shown to agree with the existent in vitro data. It turns out that the structure of aquaglyceroporin is perfect for the van der Waals interactions between the protein and glycerol to cause the existence of the bound state deep inside the conducting pore and, thus to play an unexpected but significant role in aquaglyceroporin's functions.

  10. New recombinant bacterium comprises a heterologous gene encoding glycerol dehydrogenase and/or an up-regulated native gene encoding glycerol dehydrogenase, useful for producing ethanol

    DEFF Research Database (Denmark)

    2010-01-01

    from Geobacillus. It is selected from SEQ ID NO. 1-17. Sequences not defined here may be found at ftp://ftp.wipo.int/pub/publishedpctsequences/publication. The heterologous gene encoding glycerol dehydrogenase has been incorporated into the chromosome of the bacterium, or is inserted into a lactate...... glycerol dehydrogenase; and/or (ii) up-regulating a native gene encoding glycerol dehydrogenase; and (b) obtaining the recombinant bacterium. Preferred Bacterium: In the recombinant bacterium above, the inserted heterologous gene and/or the up-regulated native gene is encoding a glycerol dehydrogenase...... selected from glycerol dehydrogenase (E.C 1.1.1.6); glycerol dehydrogenase (NADP(+)) (E.C. 1.1.1.72); glycerol 2-dehydrogenase (NADP(+)) (E.C. 1.1.1.156); and glycerol dehydrogenase (acceptor) (E.C. 1.1.99.22). The heterologous gene encoding a glycerol dehydrogenase is derived from Thermotoga or is derived...

  11. Diphytanyl and dibiphytanyl glycerol ether lipids of methanogenic archaebacteria

    Energy Technology Data Exchange (ETDEWEB)

    Tornabene, T.G. (Colorado State Univ., Fort Collins); Langworthy, T.A.

    1979-01-05

    The lipids of nine different methanogenic bacterial strains are comprised of diphytanyl glycerol diethers, previously known only in extremely halophilic bacteria, as well as dibiphytanyl diglycerol tetraethers, known formerly only in the extremely thermoacidophilic bacteria Thermoplasma and Sulfolobus. Of the methanogens examined from four representative taxonomic groups, Methanobacterium and Methanospirillum contained both types of isopranyl ethers in nearly equal proportions, whereas the coccal forms, Methanosarcina and Methanococcus, possessed diphytanyl glycerol diethers, but with only a trace of or no dibiphytanyl diglycerol tetraethers. The occurrence of both types of isopranyl glycerol ethers in methanogenic bacteria supports the proposal that they have a close genealogical relationship to the extremely halophilic and thermoacidophilic bacteria.

  12. Adipose tissue lipolysis is increased during a repeated bout of aerobic exercise

    DEFF Research Database (Denmark)

    Stich, V; de Glisezinski, I; Berlan, M

    2000-01-01

    The goal of the study was to examine whether lipid mobilization from adipose tissue undergoes changes during repeated bouts of prolonged aerobic exercise. Microdialysis of the subcutaneous adipose tissue was used for the assessment of lipolysis; glycerol concentration was measured in the dialysate...

  13. Immunochemical properties of NAD+-linked glycerol dehydrogenases from Escherichia coli and Klebsiella pneumoniae.

    OpenAIRE

    Tang, J C; Forage, R G; Lin, E C

    1982-01-01

    An NAD+-linked glycerol dehydrogenase hyperproduced by a mutant of Escherichia coli K-12 was found to be immunochemically homologous to a minor glycerol dehydrogenase of unknown physiological function in Klebsiella pneumoniae 1033, but not to the glycerol dehydrogenase of the dha system responsible for anaerobic dissimilation of glycerol or to the 2,3-butanediol dehydrogenase of K. pneumoniae.

  14. Vibrational properties of bioprotectant mixtures of trehalose and glycerol.

    Science.gov (United States)

    Magazù, Salvatore; Migliardo, Federica; Parker, Stewart F

    2011-09-22

    In this work vibrational spectra of mixtures of two glass-forming bioprotectant systems, i.e., trehalose and glycerol, are collected at very low temperature by using the indirect geometry time-of-flight (t.o.f.) TOSCA spectrometer at the ISIS Pulse Neutron Facility (Rutherford Appleton Laboratory, Oxford, U.K.). The main aim of this work is to investigate, through inelastic neutron scattering (INS), the vibrational behavior of trehalose and its mixtures with glycerol at different concentration values in order to characterize the changes induced by glycerol on the trehalose hydrogen bonded network. The obtained experimental findings, which are discussed and interpreted in the framework of previous INS, quasi elastic neutron scattering (QENS) and molecular simulation data obtained on trehalose/glycerol mixtures at different concentration and temperature values, will be linked to the different mixtures bioprotectant effectiveness.

  15. Recent advances in glycerol polymers: chemistry and biomedical applications.

    Science.gov (United States)

    Zhang, Heng; Grinstaff, Mark W

    2014-11-01

    Glycerol polymers are attracting increased attention due to the diversity of polymer compositions and architectures available. This article provides a brief chronological review on the current status of these polymers along with representative examples of their use for biomedical applications. First, the underlying chemistry of glycerol that provides access to a range of monomers for subsequent polymerizations is described. Then, the various synthetic methodologies to prepare glycerol-based polymers including polyethers, polycarbonates, polyesters, and so forth are reviewed. Next, several biomedical applications where glycerol polymers are being investigated including carriers for drug delivery, sealants or coatings for tissue repair, and agents possessing antibacterial activity are described. Fourth, the growing market opportunity for the use of polymers in medicine is described. Finally, the findings are concluded and summarized, as well as the potential opportunities for continued research efforts are discussed.

  16. Comprehensive utilization of glycerol from sugarcane bagasse pretreatment to fermentation.

    Science.gov (United States)

    Jiang, Liqun; Zheng, Anqing; Zhao, Zengli; He, Fang; Li, Haibin

    2015-11-01

    In this study, the effects of glycerol pretreatment on subsequent glycerol fermentation and biomass fast pyrolysis were investigated. The liquid fraction from the pretreatment process was evaluated to be feasible for fermentation by Paenibacillus polymyxa and could be an economic substrate. The pretreated biomass was further utilized to obtain levoglucosan by fast pyrolysis. The pretreated sugarcane bagasse exhibited significantly higher levoglucosan yield (47.70%) than that of un-pretreated sample (11.25%). The promotion could likely be attributed to the effective removal of alkali and alkaline earth metals by glycerol pretreatment. This research developed an economically viable manufacturing paradigm to utilize glycerol comprehensively and enhance the formation of levoglucosan effectively from lignocellulose.

  17. Plasma reforming of glycerol for synthesis gas production.

    Science.gov (United States)

    Zhu, Xinli; Hoang, Trung; Lobban, Lance L; Mallinson, Richard G

    2009-05-28

    Glycerol can be effectively converted to synthesis gas (selectivity higher than 80%) with small amounts of water or no water using plasmas at low temperature and atmospheric pressure, without external heating.

  18. Renewable hydrogen and carbon nanotubes from biodiesel waste glycerol.

    Science.gov (United States)

    Wu, Chunfei; Wang, Zichun; Williams, Paul T; Huang, Jun

    2013-09-25

    In this report, we introduce a novel and commercially viable method to recover renewable hydrogen and carbon nanotubes from waste glycerol produced in the biodiesel process. Gas-phase catalytic reforming converts glycerol to clean hydrogen fuel and by replacing the problematical coke formed on the catalyst with high value carbon nanotubes, added value can be realised. Additional benefits of around 2.8 kg CNTs from the reforming of 1 tonne of glycerol and the production of 500 Nm(3) H2 could have a considerable impact on the economics of glycerol utilization. Thereby, the contribution of this research will be a significant step forward in solving a current major technical and economic challenge faced by the biofuels industry.

  19. Physicochemical characterization of oil palm mesocarp fibre treated with glycerol

    Science.gov (United States)

    Nor Hamizah M., A.; Roila, A.; Rahimi M., Y.

    2015-09-01

    Lignocellulose has been identified as another source for conversion into value added products. In the present work, physicochemical features from the oil palm mesocarp fibre treated by using pure glycerol with 2% (w/w) NaOH catalyst and crude glycerol have been studied. Treatment was conducted at temperatures 150 °C for 60 min. Fibre treated by crude glycerol resulted in high percentages of holocellulose and lower content of insoluble lignin. These results suggest that crude glycerol can be used as an alternative solvent for pretreatment process. The characterization treated fibre by means of FTIR and TGA has shown significant differences compared to untreated fibre. It was revealed that treated fibre successful eliminated hemicellulose and reduce of lignin content.

  20. Biomechanical and histological evaluation of glycerol-preserved human sclerae

    OpenAIRE

    Tarciso Schirmbeck; Antonio Augusto Velasco e Cruz

    2007-01-01

    PURPOSE: To determine the histological and biomechanical characteristics of glycerol-preserved human sclera. METHODS: A total of 114 paired human sclerae were cleaned and preserved with 98% glycerol under refrigeration at 4 to 8ºC. The samples were divided into a control group with no preservation and 5 groups of 19 sclerae in 7, 15, 30, 90 and 180 days of preservation. Each specimen was submitted to histological examination and tested for traction distensibility functions. RESULTS: Preservat...

  1. Degradation behavior of poly(glycerol sebacate).

    Science.gov (United States)

    Pomerantseva, Irina; Krebs, Nicholas; Hart, Alison; Neville, Craig M; Huang, Albert Y; Sundback, Cathryn A

    2009-12-15

    Poly(glycerol sebacate) (PGS), a promising scaffold material for soft tissue engineering applications, is a soft, tough elastomer with excellent biocompatibility. However, the rapid in vivo degradation rate of PGS limits its use as a scaffold material. To determine the impact of crosslink density on degradation rate, a family of PGS materials was synthesized by incrementally increasing the curing time from 42 to 144 h, at 120 degrees C and 10 mTorr vacuum. As expected, PGS became a stiffer, tougher, and stronger elastomer with increasing curing time. PGS disks were subcutaneously implanted into rats and periodically harvested; only mild tissue responses were observed and the biocompatibility remained excellent. Regardless of crosslink density, surface erosion degradation was observed. The sample dimensions linearly decreased with implantation time, and the mass loss rates were constant after 1-week implantation. As surface erosion degradation frequently correlates with enzymatic digestion, parallel in vitro digestion studies were conducted in lipase solutions which hydrolyze ester bonds. Enzymatic digestion played a significant role in degrading PGS, and the mass loss rates were not a function of curing time. Alternative chemistry approaches will be required to decrease the enzymatic hydrolysis rate of the ester bonds in PGS polymers.

  2. Control of mechanical properties of chitin nanofiber film using glycerol without losing its characteristics.

    Science.gov (United States)

    Ifuku, Shinsuke; Ikuta, Akiko; Izawa, Hironori; Morimoto, Minoru; Saimoto, Hiroyuki

    2014-01-30

    Surface-deacetylated chitin nanofiber films plasticized with glycerol were prepared to control mechanical properties. Nanofiber networks were able to retain excessive glycerol content up to 70% to obtain self-standing film. All films were flexible and highly transparent independent of glycerol content. Glycerol significantly decreased the Young's moduli and tensile strengths, and increased the fracture strain due to its plasticizing effect. At the same time, glycerol did not change the high transparency or the low thermal expansion of the nanofiber film.

  3. Baker's yeast catalyzed asymmetric reduction of methyl acetoacetate in glycerol containing systems

    Directory of Open Access Journals (Sweden)

    Adi Wolfson

    2008-09-01

    Full Text Available The asymmetric hydrogenation of methyl acetoacetate was successfully performed with baker's yeast in pure glycerol and mixtures of glycerol and water. Though yeast viability was very low after exposure to glycerol, the enzymatic activity in pure glycerol was preserved for some days. In addition, a mixture of glycerol and water combined the advantageous of each individual solvent and resulted in high catalytic performance and efficient product extraction yield

  4. Processes and systems for the production of propylene glycol from glycerol

    Energy Technology Data Exchange (ETDEWEB)

    Frye, John G; Oberg, Aaron A; Zacher, Alan H

    2015-01-20

    Processes and systems for converting glycerol to propylene glycol are disclosed. The glycerol feed is diluted with propylene glycol as the primary solvent, rather than water which is typically used. The diluted glycerol feed is sent to a reactor where the glycerol is converted to propylene glycol (as well as other byproducts) in the presence of a catalyst. The propylene glycol-containing product from the reactor is recycled as a solvent for the glycerol feed.

  5. Glycerol inclusion levels in corn and sunflower silages

    Directory of Open Access Journals (Sweden)

    Adriana de Souza Martins

    2014-10-01

    Full Text Available Due to the seasonal cycle of forage, the use of silage to feed animals provides nutrients throughout the year. However, its quality can be improved with the inclusion of additives and other products. Glycerol is a rich source of energy and present a high efficiency of utilization by animals. The purpose of this work was to evaluate the effect of glycerol inclusion on the chemical and fermentation characteristics of corn and sunflower silages. Two silage sources (maize and sunflower were used and four levels of glycerol inclusion (0, 15, 30 and 45% based on dry matter were carried out. The experimental design was completely randomized in a 2 x 4 factorial arrangement with five replications. The pH values and chemical composition of corn and sunflower silages were determined. In both silages there was increment of dry matter, non-fiber carbohydrates and total digestible nutrients (TDN added to a reduction of crude protein, neutral detergent fiber and acid detergent fiber due to the glycerol inclusion. The corn silage required 45% glycerol to achieve the TDN level of the sunflower silage. The glycerol addition contributed to the increase in the nutritional value, offsetting loss of quality in the ensiling process.

  6. Hydration and endocrine responses to intravenous fluid and oral glycerol.

    Science.gov (United States)

    van Rosendal, S P; Strobel, N A; Osborne, M A; Fassett, R G; Coombes, J S

    2015-06-01

    Athletes use intravenous (IV) saline in an attempt to maximize rehydration. The diuresis from IV rehydration may be circumvented through the concomitant use of oral glycerol. We examined the effects of rehydrating with differing regimes of oral and IV fluid, with or without oral glycerol, on hydration, urine, and endocrine indices. Nine endurance-trained men were dehydrated by 4% bodyweight, then rehydrated with 150% of the fluid lost via four protocols: (a) oral = oral fluid only; (b) oral glycerol = oral fluid with added glycerol (1.5 g/kg); (c) IV = 50% IV fluid, 50% oral fluid; and (d) IV with oral glycerol = 50% IV fluid, 50% oral fluid with added glycerol (1.5 g/kg), using a randomized, crossover design. They then completed a cycling performance test. Plasma volume restoration was highest in IV with oral glycerol > IV > oral glycerol  > oral. Urine volume was reduced in both IV trials compared with oral. IV and IV with oral glycerol resulted in lower aldosterone levels during rehydration and performance, and lower cortisol levels during rehydration. IV with oral glycerol resulted in the greatest fluid retention. In summary, the IV conditions resulted in greater fluid retention compared with oral and lower levels of fluid regulatory and stress hormones compared with both oral conditions.

  7. Morphological and functional alterations in glycerol preserved rat aortic allografts.

    Science.gov (United States)

    Fahner, P J; Idu, M M; Legemate, D A; Vanbavel, E; Borstlap, J; Pfaffendorf, M; van Marle, J; van Gulik, T M

    2004-11-01

    Glycerol preservation is an effective method for long-term preservation of skin allografts and has a potential use in preserving arterial allografts. We evaluated the effect of glycerol concentration and incubation period on vessel-wall integrity of rat aortic allografts. No significant differences were measured in breaking strength (2.3 +/- 0.3 N) and bursting pressure (223 +/- 32 kPa) between standard glycerolized and control segments (1.7 +/- 0.3 N, 226 +/- 17 kPa). Isometric tension measurements showed complete lack of functional contraction and relaxation capacity in allograft segments prepared according to all preservation protocols. Morphologically, thickness of the vessel-wall media diminished after preservation using low (30/50/75%) or high (70/85/98%) concentrations of glycerol, as compared to control segments (i.e. 81 +/- 2.4 microm, 95 +/- 5.6 microm and 125 +/- 3.5 microm, respectively). Confocal microscopy and Fourier analysis demonstrated that vascular collagen and elastin bundle orientation had remained unaltered. Electron microscopy showed defragmentation of luminal endothelial cells. In conclusion, glycerol preservation of rat aorta resulted in an acellular tissue matrix, which maintained biomechanical integrity and extracellular matrix characteristics. The next step in the investigation will be to test the concept of glycerol preservation of arterial allografts in a vascular transplantation model.

  8. Reverse Genetics of Escherichia coli Glycerol Kinase Allosteric Regulation and Glucose Control of Glycerol Utilization In Vivo

    OpenAIRE

    Holtman, C. Kay; Pawlyk, Aaron C.; Meadow, Norman D.; Pettigrew, Donald W.

    2001-01-01

    Reverse genetics is used to evaluate the roles in vivo of allosteric regulation of Escherichia coli glycerol kinase by the glucose-specific phosphocarrier of the phosphoenolpyruvate:glycose phosphotransferase system, IIAGlc (formerly known as IIIglc), and by fructose 1,6-bisphosphate. Roles have been postulated for these allosteric effectors in glucose control of both glycerol utilization and expression of the glpK gene. Genetics methods based on homologous recombination are used to place glp...

  9. Activation of glycerol metabolic pathway by evolutionary engineering of Rhizopus oryzae to strengthen the fumaric acid biosynthesis from crude glycerol.

    Science.gov (United States)

    Huang, Di; Wang, Ru; Du, Wenjie; Wang, Guanyi; Xia, Menglei

    2015-11-01

    Rhizopus oryzae is strictly inhibited by biodiesel-based by-product crude glycerol, which results in low fumaric acid production. In this study, evolutionary engineering was employed to activate the glycerol utilization pathway for fumaric acid production. An evolved strain G80 was selected, which could tolerate and utilize high concentrations of crude glycerol to produce 14.9g/L fumaric acid with a yield of 0.248g/g glycerol. Key enzymes activity analysis revealed that the evolved strain displayed a significant upregulation in glycerol dissimilation, pyruvate consumption and reductive tricarboxylic acid pathways, compared with the parent strain. Subsequently, intracellular metabolic profiling analysis showed that amino acid biosynthesis, tricarboxylic acid cycle, fatty acid and stress response metabolites accounted for metabolic difference between two strains. Moreover, a glycerol fed-batch strategy was optimized to obtain the highest fumaric acid production of 25.5g/L, significantly increased by 20.9-fold than that of the parent strain of 1.2g/L.

  10. The Holocene Records of Glycerol Dialkyl Glycerol Tetraethers From the Northern Chukchi Sea

    Science.gov (United States)

    Park, Y.; Yamamoto, M.; Nam, S.; Polyak, L. V.

    2013-12-01

    We analyzed glycerol dialkyl glycerol tetraethers (GDGTs) in Cores HOTRAX 05-01 JPC5 and JPC 8, and ARA02B 01-GC in the northern Chukchi Sea. All of the three cores showed a similar changing pattern in GDGT composition during the Holocene. In the beginning of early Holocene, both isoprenoid and branched GDGT concentrations were low, and BIT and CBT were relatively high. The similar composition is found in modern sediments from the western Arctic Ocean north of 75°N, suggesting that the northern Chukchi Sea was covered by perennial sea ice. GDGT concentration increased, and BIT and CBT decreased during the early Holocene and reached the same level as those in modern sediments at 8 ka. TEX86 and CBT/MBT indices showed millennial-scale variation. We interpret that these proxies did not simply indicate temperatures but were affected by the relative contribution of different sediment sources. Millennial-scale variability likely reflected changes in sediment transport in the northern Chukchi Sea.

  11. Glycerol decreases the volume and compressibility of protein interior.

    Science.gov (United States)

    Priev, A; Almagor, A; Yedgar, S; Gavish, B

    1996-02-20

    The addition of hydrogen-bonded cosolvents to aqueous solutions of proteins is known to modify both thermodynamic and dynamic properties of the proteins in a variety of ways. Previous studies suggest that glycerol reduces the free volume and compressibility of proteins. However, there is no directly measured evidence for that. We have measured the apparent specific volume (V) and adiabatic compressibility (K) of a number of proteins, sugars, and amino acids in water and in 30% glycerol at pH 7.4 and 30 degrees C. The values of V and K in water and their changes induced by glycerol were extrapolated to the limit of infinite solute size. The main results were the following: (a) glycerol decreases V and K of proteins, but increases it for amino acids; (b) the V and K values of the protein interior in water were found to be 0.784 +/- 0.026 mL/g and (12.8 +/- 2.5) x 10(-6) mL/g x atm, where the glycerol reduces these values by 8 and 32%, respectively; (c) the coefficient of adiabatic compressibility of the structural component of proteins affected by the glycerol is estimated to be (50 +/- 10) x 10(-6) atm(-1), which is comparable to that of water. We propose that the glycerol induces a release of the so-called "lubricant" water, which maintains conformational flexibility by keeping apart neighboring segments of the polypeptide chain. This is expected to lead to the collapsing of the voids containing the water as well as to increase intramolecular bonding, which explains the observed effect.

  12. Manganese carbonate-zinc glycerolate, synthesis, characterization and application as catalyst for transesterification of soybean oil

    Directory of Open Access Journals (Sweden)

    Zhu Xiaochan

    2016-01-01

    Full Text Available In this study, mixed system containing manganese carbonate (MnCO3 and zinc glycerolate (ZnGly was synthesized, and tested as solid catalyst for transesterification of soybean oil and biodiesel production. The samples of MnCO3/ZnGly before and after usage for transesterification process were characterized using different techniques: determination of basic strength, determination of specific surface area according to Brunauer-Emmett-Teller (BET, measuring the mass change using thermal gravimetric analysis (TGA, investigating the solid phase content and presence of different specific elements and groups by X-Ray diffraction (XRD, the Fourier transform infrared (FT-IR spectroscopy, the scanning electron microscopy (SEM with energy dispersive spectroscopy (EDS. The effects of different working parameters of transesterification were also investigated: temperature (438-458K, duration of transesterification (0-3.5h, methanol to oil molar ratio (12:1-36:1 and used amounts of catalyst (1-5 mass%. The reusability and stability of MnCO3/ZnGly were analyzed and obtained results showed that MnCO3/ZnGly exhibited a good activity with 100% TG conversion and 81.5% FAME yield with fresh catalyst, and can give 95-100% TG conversion and 62-78% FAME yield after 13 repeated use of same amount of catalyst without regeneration processes. Content of Mn and Zn in biodiesel and glycerol was analyzed by ICP-AAS after each reuse of catalyst.

  13. Biodegradable and elastomeric poly(glycerol sebacate) as a coating material for nitinol bare stent.

    Science.gov (United States)

    Kim, Min Ji; Hwang, Moon Young; Kim, JiHeung; Chung, Dong June

    2014-01-01

    We synthesized and evaluated biodegradable and elastomeric polyesters (poly(glycerol sebacate) (PGS)) using polycondensation between glycerol and sebacic acid to form a cross-linked network structure without using exogenous catalysts. Synthesized materials possess good mechanical properties, elasticity, and surface erosion biodegradation behavior. The tensile strength of the PGS was as high as 0.28 ± 0.004 MPa, and Young's modulus was 0.122 ± 0.0003 MPa. Elongation was as high as 237.8 ± 0.64%, and repeated elongation behavior was also observed to at least three times the original length without rupture. The water-in-air contact angles of the PGS surfaces were about 60°. We also analyzed the properties of an electrospray coating of biodegradable PGS on a nitinol stent for the purpose of enhancing long-term patency for the therapeutic treatment of varicose veins disease. The surface morphology and thickness of coating layer could be controlled by adjusting the electrospraying conditions and solution parameters.

  14. Enzymatic primer-extension with glycerol-nucleoside triphosphates on DNA templates.

    Directory of Open Access Journals (Sweden)

    Jesse J Chen

    Full Text Available BACKGROUND: Glycerol nucleic acid (GNA has an acyclic phosphoglycerol backbone repeat-unit, but forms stable duplexes based on Watson-Crick base-pairing. Because of its structural simplicity, GNA is of particular interest with respect to the possibility of evolving functional polymers by in vitro selection. Template-dependent GNA synthesis is essential to any GNA-based selection system. PRINCIPAL FINDINGS: In this study, we investigated the ability of various DNA polymerases to use glycerol-nucleoside triphosphates (gNTPs as substrates for GNA synthesis on DNA templates. Therminator DNA polymerase catalyzes quantitative primer-extension by the incorporation of two glyceronucleotides, with much less efficient extension up to five glyceronucleotides. Steady-state kinetic experiments suggested that GNA synthesis by Therminator was affected by both decreased catalytic rates and weakened substrate binding, especially for pyrimidines. In an attempt to improve pyrimidine incorporation by providing additional stacking interactions, we synthesized two new gNTP analogs with 5-propynyl substituted pyrimidine nucleobases. This led to more efficient incorporation of gC, but not gT. CONCLUSIONS: We suggest that directed evolution of Therminator might lead to mutants with improved substrate binding and catalytic efficiency.

  15. Biodegradable and Elastomeric Poly(glycerol sebacate as a Coating Material for Nitinol Bare Stent

    Directory of Open Access Journals (Sweden)

    Min Ji Kim

    2014-01-01

    Full Text Available We synthesized and evaluated biodegradable and elastomeric polyesters (poly(glycerol sebacate (PGS using polycondensation between glycerol and sebacic acid to form a cross-linked network structure without using exogenous catalysts. Synthesized materials possess good mechanical properties, elasticity, and surface erosion biodegradation behavior. The tensile strength of the PGS was as high as 0.28 ± 0.004 MPa, and Young's modulus was 0.122 ± 0.0003 MPa. Elongation was as high as 237.8 ± 0.64%, and repeated elongation behavior was also observed to at least three times the original length without rupture. The water-in-air contact angles of the PGS surfaces were about 60°. We also analyzed the properties of an electrospray coating of biodegradable PGS on a nitinol stent for the purpose of enhancing long-term patency for the therapeutic treatment of varicose veins disease. The surface morphology and thickness of coating layer could be controlled by adjusting the electrospraying conditions and solution parameters.

  16. 腰骶段选择性脊神经后根切断术对痉挛型脑性瘫痪患者伴随症状的影响%The effects of selective posterior rhizotomy on combined symptoms of patients with spastic cerebral palsy

    Institute of Scientific and Technical Information of China (English)

    王业华; 徐林; 龚维成

    2002-01-01

    Objective To investigate the effects of lumbar sacral selective posterior rhizotomy on spasticity of upper limbs,epilepsy, strabismus, sialorrhea and dysarthria of patients with spastic cerebral palsy.Methods 825 patients with cerebral palsy who had received SPR between 1990 and 1998 were followed up for two years at least.Results Of 328 cases with spasticity of upper limbs,67(20.4% ) had partial amelioration of spasticity of upper limbs.Of 35 cases with epilepsy, 31(88.6% ) had lower frequency of onset or needed to take lower dose drug to control than ever.Of 386 cases with strabismus,132(34.2% ) had improved.Of 73 cases with sialorrhea,49(67.1% ) had improved, 21(28.8% ) had found sialorrhea disappeararnce.Of 456 cases with dysarthria,72(15.8% ) had improved.Conclusion Selective posterior rhizotomy has curative effect on combined symptoms in some of patients with cerebral palsy.

  17. Crude glycerol-based production of amino acids and putrescine by Corynebacterium glutamicum.

    Science.gov (United States)

    Meiswinkel, Tobias M; Rittmann, Doris; Lindner, Steffen N; Wendisch, Volker F

    2013-10-01

    Corynebacterium glutamicum possesses genes for glycerol kinase and glycerol-3-phosphate dehydrogenase that were shown to support slow growth with glycerol only when overexpressed from a plasmid. Pure glycerol and crude glycerol from biodiesel factories were tested for growth of recombinant strains expressing glpF, glpK and glpD from Escherichia coli. Some, but not all crude glycerol lots served as good carbon sources. Although the inhibitory compound(s) present in these crude glycerol lots remained unknown, the addition of substoichiometric glucose concentrations (below 10% by weight) enabled the utilization of some of the inhibitory crude glycerol lots. Besides growth, production of the amino acids L-glutamate, L-lysine, L-ornithine and L-arginine as well as of the diamine putrescine based on crude glycerol qualities from biodiesel factories was demonstrated.

  18. Percutaneous radiofrequency rhizotomy and neurovascular decompression of the trigeminal nerve for the treatment of facial pain Rizotomia percutânea por radiofreqüência e a descompressão neurovascular do nervo trigêmeo no tratamento das algias faciais

    OpenAIRE

    Teixeira, Manoel J.; Siqueira,Silvia R. D. T. de; Gilberto M. de Almeida

    2006-01-01

    OBJECTIVE: To determine the outcomes of 354 radiofrequency rhizotomies and 21 neurovascular decompressions performed as treatment for 367 facial pain patients (290 idiopathic trigeminal neuralgia, 52 symptomatic trigeminal neuralgia, 16 atypical facial pain, 9 post-herpetic neuralgia). METHOD: Clinical findings and surgery success rate were considered for evaluation. A scale of success rate was determined to classify patients, which considered pain relief and functional/sensorial deficits. RE...

  19. Effect Of Solid Acids In The Conversion Of Glycerol Over Ru/Bentonite Catalyst In Glycerol Hydrogenolysis Reaction

    Directory of Open Access Journals (Sweden)

    Noraini Hamzah

    2011-09-01

    Full Text Available Glycerol known as by-product of transesterification of vegetables oil become an important materials after some chemical modification. In this study, hydrogenolysis reaction of glycerol to 1,2-propanediol was conducted using various supported ruthenium based catalyst. The support materials used in this study are bentonite ,TiO2, Al2O3 and SiO2. All experiments were carried out at reaction condition of 150°C, hydrogen pressure 20-30 bar for 7 hours and the 20%(wt glycerol content in distilled water. The result shows that activity of the catalyts increased following this order: Ru/SiO2< Ru/TiO2 ≈ Ru/Al2O3 < Ru/bentonite. High selectivity to 1,2-propanediol was obtained in hydrogenolysis glycerol over Ru/TiO2 (83.7% and Ru/bentonite (80.1% catalysts. Since Ru/bentonite catalyst performed better than other tested catalyst, we choose this catalyst system to investigate the effect of various solid acids (zeolite, ZrO2, Nb2O5 and amberlyst on conversion of glycerol in hydrogenolysis reaction. Addition of solid acid in hydrogenolysis glycerol had promote the activity of Ru/bentonite catalyst drastically. The result shows that the presence of zeolite make the conversion of glycerol increased to maximum from 62.8% to 81.6% compared the other solid acids. Interestingly, selectivity to 1,2-propanediol still was achieved over 80.0%. These catalysts system were characterized by XRD, XPS, BET, and TEM for obtaining some physicochemical properties of the catalysts.

  20. Dysferlin and myoferlin regulate transverse tubule formation and glycerol sensitivity.

    Science.gov (United States)

    Demonbreun, Alexis R; Rossi, Ann E; Alvarez, Manuel G; Swanson, Kaitlin E; Deveaux, H Kieran; Earley, Judy U; Hadhazy, Michele; Vohra, Ravneet; Walter, Glenn A; Pytel, Peter; McNally, Elizabeth M

    2014-01-01

    Dysferlin is a membrane-associated protein implicated in muscular dystrophy and vesicle movement and function in muscles. The precise role of dysferlin has been debated, partly because of the mild phenotype in dysferlin-null mice (Dysf). We bred Dysf mice to mice lacking myoferlin (MKO) to generate mice lacking both myoferlin and dysferlin (FER). FER animals displayed progressive muscle damage with myofiber necrosis, internalized nuclei, and, at older ages, chronic remodeling and increasing creatine kinase levels. These changes were most prominent in proximal limb and trunk muscles and were more severe than in Dysf mice. Consistently, FER animals had reduced ad libitum activity. Ultrastructural studies uncovered progressive dilation of the sarcoplasmic reticulum and ectopic and misaligned transverse tubules in FER skeletal muscle. FER muscle, and Dysf- and MKO-null muscle, exuded lipid, and serum glycerol levels were elevated in FER and Dysf mice. Glycerol injection into muscle is known to induce myopathy, and glycerol exposure promotes detachment of transverse tubules from the sarcoplasmic reticulum. Dysf, MKO, and FER muscles were highly susceptible to glycerol exposure in vitro, demonstrating a dysfunctional sarcotubule system, and in vivo glycerol exposure induced severe muscular dystrophy, especially in FER muscle. Together, these findings demonstrate the importance of dysferlin and myoferlin for transverse tubule function and in the genesis of muscular dystrophy.

  1. Biomechanical and histological evaluation of glycerol-preserved human sclerae.

    Science.gov (United States)

    Schirmbeck, Tarciso; Cruz, Antonio Augusto Velasco E

    2007-01-01

    To determine the histological and biomechanical characteristics of glycerol-preserved human sclera. A total of 114 paired human sclerae were cleaned and preserved with 98% glycerol under refrigeration at 4 to 8 degrees C. The samples were divided into a control group with no preservation and 5 groups of 19 sclerae in 7, 15, 30, 90 and 180 days of preservation. Each specimen was submitted to histological examination and tested for traction distensibility functions. Preservation in glycerol did not cause alterations in the histological architecture of the scleral tissue. The mean load required to break the scleral tissue increased according to preservation time as a sigmoid function. A significant increase in mechanical resistance and decrease in distension of scleral tissue occurred after 90 days of preservation. Scleral preservation in glycerol keeps tissue integrity. The preserved material is less distensible after 90 days. Surgeons who use sclera in ophthalmic procedures should be aware of the mechanical characteristics of glycerol-preserved sclera and take into account tissue preservation time.

  2. Effect of NaCl on the accumulation of glycerol by three Aspergillus species.

    Science.gov (United States)

    Zidan, M A; Abdel-Mallek, A Y

    1987-01-01

    The accumulation of glycerol was investigated in three Aspergillus species, A. niger, A. ochraceus and A. tamarii after being grown in media containing different NaCl concentrations. Intra-extracellular as well as total glycerol were markedly accumulated by the three organisms in response to increased salinity. However, at salinity levels of 10-14% NaCl, extracellular glycerol was somewhat lowered. In addition, it was found that the maximum accumulation of glycerol in A. niger and A. tamarii was reached within the first 10 hours after salinization. However, after desalinization, the extracellular glycerol was continuously increased within the first 6 hours at the expense of intracellular glycerol.

  3. Chemoselective catalytic conversion of glycerol as a biorenewable source to valuable commodity chemicals.

    Science.gov (United States)

    Zhou, Chun-Hui Clayton; Beltramini, Jorge N; Fan, Yong-Xian; Lu, G Q Max

    2008-03-01

    New opportunities for the conversion of glycerol into value-added chemicals have emerged in recent years as a result of glycerol's unique structure, properties, bioavailability, and renewability. Glycerol is currently produced in large amounts during the transesterification of fatty acids into biodiesel and as such represents a useful by-product. This paper provides a comprehensive review and critical analysis on the different reaction pathways for catalytic conversion of glycerol into commodity chemicals, including selective oxidation, selective hydrogenolysis, selective dehydration, pyrolysis and gasification, steam reforming, thermal reduction into syngas, selective transesterification, selective etherification, oligomerization and polymerization, and conversion of glycerol into glycerol carbonate.

  4. Effects of addition glycerol co-product of biodiesel in the thermophysical properties of water-glycerol solution applied as secondary coolant

    Energy Technology Data Exchange (ETDEWEB)

    Medeiros, Pedro Samuel Gomes; Barbosa, Cleiton Rubens Formiga; Fontes, Francisco de Assis Oliveira [Federal University of Rio Grande do Norte, Natal, RN (Brazil). Energy Laboratory. Thermal Systems Studies Group], e-mail: cleiton@ufrnet.br

    2010-07-01

    This paper evaluates the effects of glycerol concentration on thermophysical properties of water-glycerol solution applied as a secondary coolant in refrigeration systems by expansion-indirect. The processing of triglycerides for biodiesel production generates glycerol as co-product and there are concerns of environmental and economic order on the surplus of glycerol. The addition of glycerol in water alters the colligative and thermophysical properties (melting point, mass, specific heat, thermal conductivity and dynamic viscosity). There are studies that prove the feasibility of using glycerol as an additive and this paper has the goal to verify the changes on properties compared with pure water. This comparison was made from data obtained by the software simulation and they analyzed using graphs and tables. It was shown that glycerol increases the density and dynamic viscosity, and reduces the specific heat and thermal conductivity. This behavior of water-glycerol solution is proportional to the mass concentration of glycerol and it is justified because the glycerol has low values of specific heat, thermal conductivity and high viscosity when compared with water. Despite the losses in the thermophysical properties, glycerol shows its potential application, because of the cryoscopic effect and it is a non-toxic substance at low cost. (author)

  5. Production of technical-grade sodium citrate from glycerol-containing biodiesel waste by Yarrowia lipolytica.

    Science.gov (United States)

    Kamzolova, Svetlana V; Vinokurova, Natalia G; Lunina, Julia N; Zelenkova, Nina F; Morgunov, Igor G

    2015-10-01

    The production of technical-grade sodium citrate from the glycerol-containing biodiesel waste by Yarrowia lipolytica was studied. Batch experiments showed that citrate was actively produced within 144 h, then citrate formation decreased presumably due to inhibition of enzymes involved in this process. In contrast, when the method of repeated batch cultivation was used, the formation of citrate continued for more than 500 h. In this case, the final concentration of citrate in the culture liquid reached 79-82 g/L. Trisodium citrate was isolated from the culture liquid filtrate by the addition of a small amount of NaOH, so that the pH of the filtrate increased to 7-8. This simple and economic isolation procedure gave the yield of crude preparation containing trisodium citrate 5.5-hydrate up to 82-86%.

  6. Source, settling and degradation of branched glycerol dialkyl glycerol tetraethers in the marine water column

    Science.gov (United States)

    Yamamoto, Masanobu; Shimamoto, Akifumi; Fukuhara, Tatsuo; Tanaka, Yuichiro

    2016-10-01

    Branched glycerol dialkyl glycerol tetraethers (branched GDGTs) are commonly found in distal marine sediments. However, their presence in the water column, source and delivery process are not fully understood. In this study, we examined seasonal and depth variation in the flux of branched GDGTs in sinking particles and underlying sediment at 39°N, 147°E in the mid-latitude NW Pacific from November 1997 to August 1999. Branched GDGTs showed synchronous variation in their sinking flux at different depths, and the variation was similar to that of lithogenic material of eolian dust origin. Their degrees of cyclization and methylation were nearly constant and bear some resemblance to those of alkaline soils. This suggests that westerly winds transport branched GDGTs to the study site via the atmosphere from continental Asia. The sinking flux of branched GDGTs was higher in 1999 than in 1998, presumably reflecting changes in the migration path of Asian dust in response to the El Niño-Southern Oscillation. Synchronous variation in branched GDGT concentrations at different depths implies rapid vertical transport of branched GDGTs to deep water with a sinking velocity exceeding 260 m d-1. The sinking flux of the branched GDGTs decreased with increasing depth, but the rate of decrease was much smaller than those of other compounds. The preservation efficiency of branched GDGTs was 3.5-6.4% of surface inputs at the water-sediment interface, which is much higher than those of isoprenoid GDGTs (1.0-1.3%) and other compounds. The branched and isoprenoid tetraether (BIT) index values were extremely low (i.e. <0.0015) in comparison with any other studies so far. The BIT values in the surface sediment were five times higher than those in sinking particles, which is attributed to the preferential preservation of branched GDGTs in oxic environments.

  7. In Situ Production of Branched Glycerol Dialkyl Glycerol Tetraethers in a Great Basin Hot Spring (USA

    Directory of Open Access Journals (Sweden)

    Chuanlun eZhang

    2013-07-01

    Full Text Available Branched glycerol dialkyl glycerol tetraethers (bGDGTs are predominantly found in soils and peat bogs. In this study, we analyzed core-bGDGTs and polar (P- bGDGTs after hydrolysis of polar fractions using liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry and analyzed intact P-bGDGTs using total lipid extract (TLE without hydrolysis by liquid chromatography-electrospray ionization-multiple stage mass spectrometry. Our results show multiple lines of evidence for the production of bGDGTs in sediments and cellulolytic enrichments in a hot spring (62-86°C in the Great Basin (USA. First, in situ cellulolytic enrichment led to an increase in the relative abundance of hydrolysis-derived P-bGDGTs over their Core (C-bGDGT counterparts. Second, the hydrolysis-derived P- and C-bGDGT profiles in the hot spring were different from those of the surrounding soil samples; in particular, a monoglycosidic bGDGT Ib containing 13,16-dimethyloctacosane and one cyclopentane moiety was detected in the TLE but it was undetectable in surrounding soil samples even after sample enrichments. Third, previously published 16S rRNA gene pyrotag analysis from the same lignocellulose samples demonstrated the enrichment of thermophiles, rather than mesophiles, and total bGDGT abundance in cellulolytic enrichments correlated with the relative abundance of 16S rRNA gene pyrotags from thermophilic bacteria in the phyla Bacteroidetes, Dictyoglomi, EM3, and OP9 (Atribacteria. These observations conclusively demonstrate the production of bGDGTs in this hot spring; however, the identity of organisms that produce bGDGTs in the geothermal environment remains unclear.

  8. Water availability determines branched glycerol dialkyl glycerol tetraether distributions in soils of the Iberian Peninsula

    Directory of Open Access Journals (Sweden)

    J. Menges

    2013-06-01

    Full Text Available The MBT/CBT has recently gained significant attention as a novel paleotemperature proxy. It is based on the distribution of branched glycerol dialkyl glycerol tetraethers (GDGTs in soils. The CBT quantifies the degree of cyclisation and relates to soil pH. The MBT' quantifies the degree of methylation and relates to mean annual temperature and soil pH. Combining these two indices allows estimation of mean annual temperature (MAT. However other factors such as soil water availability or moisture conditions have been suggested to influence the MBT'. To assess the effect of moisture conditions on the MBT'/CBT a set of 23 Iberian Peninsula soil samples covering a temperature range from 10–18 °C and a wide range of soil moisture regimes (405 mm to 1455 mm mean annual precipitation per year, was analyzed. We find that CBT is significantly correlated to soil pH confirming it as a robust proxy. In contrast the MBT' index was not correlated to MAT and was weakly correlated to annual mean precipitation (MAP. Instead we found a significant correlation between MBT' and the Aridity Index (AI, a parameter related to water availability in soils. The AI can explain 70% of the residuals of MAT estimation and 50% of the actual variation of the MBT'. This suggests that in dry environments or under moisture shortage the degree of methylation of branched GDGTs is not controlled by temperature but rather by the degree of water available. Our results suggest that the MBT/CBT index is not applicable as a paleotemperature proxy in dry subhumid to hyperarid environments.

  9. Quantum repeated games revisited

    CERN Document Server

    Frackiewicz, Piotr

    2011-01-01

    We present a scheme for playing quantum repeated 2x2 games based on the Marinatto and Weber's approach to quantum games. As a potential application, we study twice repeated Prisoner's Dilemma game. We show that results not available in classical game can be obtained when the game is played in the quantum way. Before we present our idea, we comment on the previous scheme of playing quantum repeated games.

  10. Glycerol kinase activities in muscles from vertebrates and invertebrates.

    Science.gov (United States)

    Newsholme, E A; Taylor, K

    1969-05-01

    1. Glycerol kinase (EC 2.7.1.30) activity was measured in crude extracts of skeletal muscles by a radiochemical method. The properties of the enzyme from a number of different muscles are very similar to those of the enzyme from rat liver. Glycerol kinase from locust flight muscle was inhibited competitively by l-3-glycerophosphate with a K(i) of 4.0x10(-4)m. 2. The activity of glycerol kinase was measured in a variety of muscles from vertebrates and invertebrates in an attempt to explain the large variation in the activity of this enzyme in different muscles. 3. In vertebrates glycerol kinase activities were generally higher in red muscle than in white muscle; the highest activities (approx. 0.2mumole/min./g. fresh wt.) were found in the red breast muscle of some birds (e.g. pigeon, duck, blue tit) whereas the activities in the white breast muscle of the pheasant and domestic fowl were very low (approx. 0.02mumole/min./g.). 4. On the basis of glycerol kinase activities, muscles from insects can be classified into three groups: muscles that have a low enzyme activity, i.e. muscles of all insects studied and the flight muscles of cockroaches and the tsetse fly); muscles that have an intermediate enzyme activity, i.e. 0.3-1.5mumoles/min./g. (e.g. locusts, cockchafers, moths, water-bugs); and muscles that have a high enzyme activity, i.e. >1.5mumoles/min./g. (e.g. bees, wasps, some blowflies). 5. The function of glycerol kinase in vertebrate and insect muscles that possess a low or intermediate activity is considered to be the removal of glycerol that is produced from lipolysis of triglyceride or diglyceride by the muscle. Therefore in these muscles the activity of glycerol kinase is related to the metabolism of fat, which is used to support sustained muscular activity. A possible regulatory role of glycerol kinase in the initiation of triglyceride or diglyceride lipolysis is discussed. 6. The function of glycerol kinase in the insect muscles that possess a high

  11. Animal Bones Char Solubilization by Gel-Entrapped Yarrowia lipolytica on Glycerol-Based Media

    Directory of Open Access Journals (Sweden)

    Maria Vassileva

    2012-01-01

    Full Text Available Citric acid was produced with free and k-carrageenan-entrapped cells of the yeast Yarrowia lipolytica in single and repeated batch-shake-flask fermentations on glycerol-based media. Simultaneous solubilization of hydroxyapatite of animal bone origin (HABO was tested in all experiments. The highest citric acid production by free yeast cells of 20.4 g/L and 18.7 g/L was reached after 96 h of fermentation in the absence and presence of 3 g/L HABO, respectively. The maximum values for the same parameter achieved by gel-entrapped cells in conditions of single batch and repeated-batch fermentation processes were 18.7 g/L and 28.1 g/L registered after 96 h and the 3d batch cycle, respectively. The highest citric acid productivity of 0.58 g L−1 h−1 was obtained with immobilized cells in repeated batch mode of fermentation when the added hydroxyapatite of 3 g/L was solubilized to 399 mg/L whereas the maximum efficiency of 89.0% was obtained with 1 g/L of HABO.

  12. Production of 1,2-propanediol from glycerol in Saccharomyces cerevisiae.

    Science.gov (United States)

    Jung, Joon-Young; Yun, Hyun Shik; Lee, Jinwon; Oh, Min-Kyu

    2011-08-01

    Glycerol has become an attractive carbon source in the biotechnology industry owing to its low price and reduced state. However, glycerol is rarely used as a carbon source in Saccharomyces cerevisiae because of its low utilization rate. In this study, we used glycerol as a main carbon source in S. cerevisiae to produce 1,2-propanediol. Metabolically engineered S. cerevisiae strains with overexpression of glycerol dissimilation pathway genes, including glycerol kinase (GUT1), glycerol 3-phosphate dehydrogenase (GUT2), glycerol dehydrogenase (gdh), and a glycerol transporter gene (GUP1), showed increased glycerol utilization and growth rate. More significant improvement of glycerol utilization and growth rate was accomplished by introducing 1,2-propanediol pathway genes, mgs (methylglyoxal synthase) and gldA (glycerol dehydrogenase) from Escherichia coli. By engineering both glycerol dissimilation and 1,2-propanediol pathways, the glycerol utilization and growth rate were improved 141% and 77%, respectively, and a 2.19 g 1,2- propanediol/l titer was achieved in 1% (v/v) glycerolcontaining YEPD medium in engineered S. cerevisiae.

  13. 2H NMR studies of glycerol dynamics in protein matrices.

    Science.gov (United States)

    Herbers, C R; Sauer, D; Vogel, M

    2012-03-28

    We use (2)H NMR spectroscopy to investigate the rotational motion of glycerol molecules in matrices provided by the connective tissue proteins elastin and collagen. Analyzing spin-lattice relaxation, line-shape properties, and stimulated-echo decays, we determine the rates and geometries of the motion as a function of temperature and composition. It is found that embedding glycerol in an elastin matrix leads to a mild slowdown of glycerol reorientation at low temperatures and glycerol concentrations, while the effect vanishes at ambient temperatures or high solvent content. Furthermore, it is observed that the nonexponential character of the rotational correlation functions is much more prominent in the elastin matrix than in the bulk liquid. Results from spin-lattice relaxation and line shape measurements indicate that, in the mixed systems, the strong nonexponentiality is in large part due to the existence of distributions of correlation times, which are broader on the long-time flank and, hence, more symmetric than in the neat system. Stimulated-echo analysis of slow glycerol dynamics reveals that, when elastin is added, the mechanism for the reorientation crosses over from small-angle jump dynamics to large-angle jump dynamics and the geometry of the motion changes from isotropic to anisotropic. The results are discussed against the background of present and previous findings for glycerol and water dynamics in various protein matrices and compared with observations for other dynamically highly asymmetric mixtures so as to ascertain in which way the viscous freezing of a fast component in the matrix of a slow component differs from the glassy slowdown in neat supercooled liquids.

  14. 2H NMR studies of glycerol dynamics in protein matrices

    Science.gov (United States)

    Herbers, C. R.; Sauer, D.; Vogel, M.

    2012-03-01

    We use 2H NMR spectroscopy to investigate the rotational motion of glycerol molecules in matrices provided by the connective tissue proteins elastin and collagen. Analyzing spin-lattice relaxation, line-shape properties, and stimulated-echo decays, we determine the rates and geometries of the motion as a function of temperature and composition. It is found that embedding glycerol in an elastin matrix leads to a mild slowdown of glycerol reorientation at low temperatures and glycerol concentrations, while the effect vanishes at ambient temperatures or high solvent content. Furthermore, it is observed that the nonexponential character of the rotational correlation functions is much more prominent in the elastin matrix than in the bulk liquid. Results from spin-lattice relaxation and line shape measurements indicate that, in the mixed systems, the strong nonexponentiality is in large part due to the existence of distributions of correlation times, which are broader on the long-time flank and, hence, more symmetric than in the neat system. Stimulated-echo analysis of slow glycerol dynamics reveals that, when elastin is added, the mechanism for the reorientation crosses over from small-angle jump dynamics to large-angle jump dynamics and the geometry of the motion changes from isotropic to anisotropic. The results are discussed against the background of present and previous findings for glycerol and water dynamics in various protein matrices and compared with observations for other dynamically highly asymmetric mixtures so as to ascertain in which way the viscous freezing of a fast component in the matrix of a slow component differs from the glassy slowdown in neat supercooled liquids.

  15. Crude glycerol combustion: Particulate, acrolein, and other volatile organic emissions

    KAUST Repository

    Steinmetz, Scott

    2013-01-01

    Crude glycerol is an abundant by-product of biodiesel production. As volumes of this potential waste grow, there is increasing interest in developing new value added uses. One possible use, as a boiler fuel for process heating, offers added advantages of energy integration and fossil fuel substitution. However, challenges to the use of crude glycerol as a boiler fuel include its low energy density, high viscosity, and high autoignition temperature. We have previously shown that a refractory-lined, high swirl burner can overcome challenges related to flame ignition and stability. However, critical issues related to ash behavior and the possible formation of acrolein remained. The work presented here indicates that the presence of dissolved catalysts used during the esterification and transesterification processes results in extremely large amounts of inorganic species in the crude glycerol. For the fuels examined here, the result is a submicron fly ash comprised primarily of sodium carbonates, phosphates, and sulfates. These particles report to a well-developed accumulation mode (0.3-0.7 μm diameter), indicating extensive ash vaporization and particle formation via nucleation, condensation, and coagulation. Particle mass emissions were between 2 and 4 g/m3. These results indicate that glycerol containing soluble catalyst is not suitable as a boiler fuel. Fortunately, process improvements are currently addressing this issue. Additionally, acrolein is of concern due to its toxicity, and is known to be formed from the low temperature thermal decomposition of glycerol. Currently, there is no known reliable method for measuring acrolein in sources. Acrolein and emissions of other volatile organic compounds were characterized through the use of a SUMMA canister-based sampling method followed by GC-MS analysis designed for ambient measurements. Results indicate crude glycerol combustion produces relatively small amounts of acrolein (∼15 ppbv) and other volatile organic

  16. Haemodynamic and cerebrovascular responses to glycerol infusion in dogs.

    Science.gov (United States)

    Chen, J L; Wang, Y C; Wang, J Y

    1989-11-01

    1. The response of cerebral blood vessels to hyperosmolar agents in vivo remains controversial, and little is known about the effect of glycerol on cerebral vessels. In this study we investigated the cerebrovascular response to intravenous administration of glycerol (1 g/kg, infused over 25 min) in dogs under pentobarbital anaesthesia. 2. intracranial pressure, systemic arterial pressure, mean arterial blood pressure, serum osmolarity and packed cell volume were continuously monitored, and blood gases were checked frequently. Through a parietal cranial window, pial vessel diameter was measured by means of a surgical microscope and a video image-analyser. 3. Pial vessel diameter increased gradually with a maximum at 30 min after the beginning of glycerol infusion. The maximum increase in diameter in small (less than or equal to 100 microns) vessels was 14.3%, whereas that in large (greater than 100 microns) vessels was 10.3%. There was only a slight increase (less than 4%) in pial vessel diameter in vehicle-infused animals. The intracranial pressure decreased drastically after glycerol infusion, whereas the mean arterial blood pressure remained constant. There were correlations between the rise in serum osmolarity, fall in packed cell volume and vasodilatation, indicating that glycerol caused vasodilatation accompanied by plasma volume expansion. 4. Our data suggest that glycerol produces cerebral vasodilatation, which might be beneficial in cerebral ischaemia and vasospasm, in addition to its intracranial pressure-reducing effect on normal or oedematous brain. The degree of vasodilatation was not sufficient to affect the predominant intracranial pressure drop resulting from cerebral dehydration.

  17. Glycerol and bioglycerol conversion in supercritical water for hydrogen production.

    Science.gov (United States)

    Yu-Wu, Q M; Weiss-Hortala, E; Barna, R; Boucard, H; Bulza, S

    2012-01-01

    Catalytic transesterification of vegetable oils leads to biodiesel and an alkaline feed (bioglycerol and organic residues, such as esters, alcohols. . .). The conversion ofbioglycerol into valuable organic molecules represents a sustainable industrial process leading to the valorization of a renewable organic resource. The physicochemical properties in the supercritical domain (T > 374 degrees C, P > 22.1 MPa) transform water into a solvent for organics and a reactant favouring radical reactions. In this context, the conversion ofbioglycerol in supercritical water (SCW) into platform molecules and/or high energetic gases (hydrogen, hydrocarbons) could represent an interesting valorization process. The reported research results concern the conversion of bioglycerol compared to pure glycerol. The experiments have been done in batch autoclaves (5 ml and 500 ml stirred). Solutions of pure (5 or 10 wt%) and crude (3.5 wt%) glycerol have been processed with or without catalyst (K2CO3 1.5 wt%) in the range of 450-600 degrees C. The molecular formula of bioglycerol was determined as C4.3H9.7O1.8Na0.1Si0.08. Glycerol was partially decomposed in the batch systems during the heating (42% before reaching 420 degrees C) and some intermediates (propanediol, ethylene glycol . . .) were quantified, leading to a proposition of a reaction pathway. Acrolein, a valuable platform molecule, was mainly produced in the absence of catalyst. No solid phase was recovered after SCW conversion of pure and bioglycerol in batch reactors. The optimal parameters for gasification were 600 degrees C, 25 MPa for bioglycerol and 525 degrees C, 25 MPa, for pure glycerol. In these operating conditions, 1 kg of pure or bioglycerol leads to 15 and, respectively, 10 mol of hydrogen. Supercritical water gasification of crude glycerol favoured the generation of light hydrocarbons, while pure glycerol promoted H2 production. SCW conversion of glycerol (pure and crude) allows to obtain simultaneously energetic

  18. Propylene from renewable resources: catalytic conversion of glycerol into propylene.

    Science.gov (United States)

    Yu, Lei; Yuan, Jing; Zhang, Qi; Liu, Yong-Mei; He, He-Yong; Fan, Kang-Nian; Cao, Yong

    2014-03-01

    Propylene, one of the most demanded commodity chemicals, is obtained overwhelmingly from fossil resources. In view of the diminishing fossil resources and the ongoing climate change, the identification of new efficient and alternative routes for the large-scale production of propylene from biorenewable resources has become essential. Herein, a new selective route for the synthesis of propylene from bio-derived glycerol is demonstrated. The route consists of the formation of 1-propanol (a versatile bulk chemical) as intermediate through hydrogenolysis of glycerol at a high selectivity. A subsequent dehydration produces propylene. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Study of rosin glycerol esters as microencapsulating materials.

    Science.gov (United States)

    Pathak, Y V; Dorle, A K

    1985-01-01

    Rosin esters were prepared by heating rosin with glycerol and intermediate reaction products with different acid values were withdrawn. Salicylic acid granules were encapsulated using a 10 per cent solution of rosin esters in acetone. The coated microcapsules were evaluated for moisture absorption, flow properties and dissolution studies. The results showed that rosin and rosin-glycerol intermediates with acid values of 122, 105 and 55 had excellent moisture protection properties. Dissolution studies showed that these could be used for delayed release of drug.

  20. Study of abietic acid glycerol derivatives as microencapsulating materials.

    Science.gov (United States)

    Puranik, P K; Dorle, A K

    1991-01-01

    Abietic acid (85 per cent pure) was extracted from rosin N Grade and further standardized. Abietic acid derivatives were prepared by heating abietic acid with glycerol and intermediate reaction products with different acid values were collected. Salicylic acid granules were encapsulated using a 10 per cent solution of abietic acid and its derivatives by standard spray pan technique. The coated microcapsules were evaluated for moisture absorption, dissolution and flow properties. The result showed that abietic acid glycerol derivatives, AaG-54 and AaG-20 had better moisture protection properties. Dissolution studies indicate that these derivatives could be used for delayed release of drugs.

  1. Steam Reforming of Glycerol for Hydrogen Production over Catalyst

    OpenAIRE

    Sadanandam, G.; Sreelatha, N.; Phanikrishna Sharma, M. V.; Kishta Reddy, S.; B. Srinivas; K. Venkateswarlu; T. Krishnudu; Subrahmanyam, M; Durga Kumari, V.

    2012-01-01

    The performance of Ni/SiO2 catalyst for glycerol reforming has been investigated in fixed-bed reactor using careful tailoring of the operational conditions. In this paper, a commercial Engelhard catalyst has been sized and compared to gas product distribution versus catalyst size, water-to-carbon ratio, and stability of the catalyst system. Ni/SiO2 catalysts of three sizes (2×2, 2×4, and 3×5 mm) are evaluated using glycerol: water mixture at 600°C to produce 2 L H2 g−1 cat h−1. The results in...

  2. Studies on cardiolipin III. Structural identity of ox-heart cardiolipin and synthetic diphosphatidyl glycerol

    NARCIS (Netherlands)

    Haas, Gerard H. de; Bonsen, P.P.M.; Deenen, L.L.M. van

    1966-01-01

    Chemical synthesis of diphosphatidyl glycerol, a long-chain fatty acid ester of diphosphatidyl glycerol, phosphatidyl diglyceride and phosphatidyl glycerophosphate has stimulated a structural comparison with natural cardiolipin. Although in certain properties the various polyglycerol phospholipids a

  3. Studies on cardiolipin III. Structural identity of ox-heart cardiolipin and synthetic diphosphatidyl glycerol

    NARCIS (Netherlands)

    Haas, Gerard H. de; Bonsen, P.P.M.; Deenen, L.L.M. van

    1966-01-01

    Chemical synthesis of diphosphatidyl glycerol, a long-chain fatty acid ester of diphosphatidyl glycerol, phosphatidyl diglyceride and phosphatidyl glycerophosphate has stimulated a structural comparison with natural cardiolipin. Although in certain properties the various polyglycerol phospholipids a

  4. Characterization and optimization of glycerol/sebacate ratio in poly(glycerol-sebacate) elastomer for cell culture application.

    Science.gov (United States)

    Guo, Xiao-Long; Lu, Xi-Li; Dong, De-Li; Sun, Zhi-Jie

    2014-11-01

    Poly(glycerol-sebacate) (PGS) is an elastomeric biodegradable polyester. Our previous series of studies have showed that PGS has good biocompatibility. In view of the potential use of PGS in bioengineering, we attempt to characterize the PGS polymer with different ratio of glycerol and sebacic acid, and the cell adhesion and growth on these polymers. PGSs with different proportion of glycerol and sebacic acid were synthesized by polycondensation reaction. The microstructure of the series PGSs were characterized by infrared spectroscopy and X-ray diffraction analysis (XRD). Results showed that, with the increase of the ratio of sebacic acid in PGS from 1:0.8, 1:1, to 1:1.2 (ratio of glycerol to sebacic acid), the main diffraction peak in XRD, the sol content and gel swelling increased but then decreased, suggesting that the degree of crosslinking and the inherent degree of order of the series PGS increased and then decreased. With the increase of sebacic acid proportion, water absorption increased and then decreased, and the water absorption ranged from 9.62% to 10.66%. The mass loss of the series of samples in degradation experiments ranged from 24.63% to 40.06% on the 32nd day of degradation. Cell culture data suggested that the polymer with the ratio of 1:0.8 for glycerol and sebacate was suitable for cell adhesion and growth. In conclusion, PGS can be used as the cell culture matrix by modifying the composition ratio of glycerol and sebacic acid to improve the properties of cell adhesion and growth.

  5. Valorization of crude glycerol and eggshell biowaste as media components for hydrogen production: A scale-up study using co-culture system.

    Science.gov (United States)

    Pachapur, Vinayak Laxman; Das, Ratul Kumar; Brar, Satinder Kaur; Le Bihan, Yann; Buelna, Gerardo

    2017-02-01

    The properties of eggshells (EGS) as neutralizing and immobilizing agent were investigated for hydrogen (H2) production using crude glycerol (CG) by co-culture system. Eggshells of different sizes and concentrations were used during batch and repeated-batch fermentation. For batch and repeated-batch fermentation, the maximum H2 production (36.53±0.53 and 41.16±0.95mmol/L, respectively) was obtained with the EGS size of 33μmglycerol utilization was obtained.

  6. A specific receptor site for glycerol, a new sweet tastant for Drosophila: structure-taste relationship of glycerol in the labellar sugar receptor cell.

    Science.gov (United States)

    Koseki, Takaya; Koganezawa, Masayuki; Furuyama, Akira; Isono, Kunio; Shimada, Ichiro

    2004-10-01

    Glycerol, a linear triol, is a sweet tastant for mammals but it has not previously been recognized to stimulate the sense of taste in insects. Here we show by electrophysiological experimentation that it effectively stimulates the labellar sugar receptor cell of Drosophila. We also show that in accord with the electrophysiological observations, the behavioral feeding response to glycerol is dose dependent. 3-Amino-1,2-propanediol inhibited the response of the sugar receptor cell to glycerol, specifically and competitively, while it had almost no effect on responses to sucrose, D-glucose, D-fructose and trehalose. In the null Drosophila mutant for the trehalose receptor (DeltaEP19), the response to glycerol showed no change, in sharp contrast with a characteristic drastic decrease in the response to trehalose. The glycerol concentration-response curves for I-type and L-type labellar hairs were statistically indistinguishable, while those for sucrose, D-glucose, D-fructose and trehalose were clearly different. These all indicate the presence of a specific receptor site for glycerol. The glycerol site was characterized by comparing the effectiveness of various derivatives of glycerol. Based on this structure-taste relationship of glycerol, a model is proposed for the glycerol site including three subsites and two steric barriers, which cannot accommodate carbon-ring containing sugars such as D-glucose. Copyright 2004 Oxford University Press

  7. Influence of palm oil and glycerol on properties of fish skin gelatin-based films.

    Science.gov (United States)

    Nilsuwan, Krisana; Benjakul, Soottawat; Prodpran, Thummanoon

    2016-06-01

    Properties of fish skin gelatin film incorporated with palm oil at 50 and 75 % (w/w) as affected by glycerol at 0-30 % (w/w) were investigated. Increases in water vapour permeability and elongation at break along with decrease in tensile strength were noticed when levels of glycerol were increased (p glycerol levels were increased (p glycerol improved water vapour barrier property of fish skin gelatin films without drastic alteration of mechanical properties.

  8. Direct measurement of the surface dynamics of supercooled liquid-glycerol by optical scanning a film

    Institute of Scientific and Technical Information of China (English)

    Zhang Fang; Zhang Guo-Feng; Dong Shuang-Li; Sun Jian-Hu; Chen Rui-Yun; Xiao Lian-Tuan; Jia Suo-Tang

    2009-01-01

    The surface dynamics of supercooled liquid-glycerol is studied by scanning the thickness of the glycerol film with single photon detection. Measurements are performed at room temperature well above the glycerol's glass transition temperature. It is shown that the surface dynamics of the glycerol film is very sensitive to the temperature. The linear relationship between the thickness of the film and the viscosity predicted by the Vogel-Fulcher-Tammann-Hesse (VFTH) law is also presented experimentally.

  9. Synthesis and enzymic hydrolysis of an o-alanyl ester of phosphatidyl glycerol

    NARCIS (Netherlands)

    Bonsen, P.P.M.; Haas, Gerard H. de; Deenen, L.L.M. van

    1965-01-01

    A racemic 0-alanyl ester of phosphatidyl glycerol, containing one saturated and one unsaturated fatty acid, was synthesized by a reaction between silver benzyl- (γ-oleoyl-β-palmitoyl)-Dl-[alpha]-glycerol phosphate and DL-[alpha]-iodo-B-tert.-butyl-y-(N-tert.-butoxycarbonyl)-m-alanyl glycerol. The sy

  10. Synthesis and enzymic hydrolysis of an o-alanyl ester of phosphatidyl glycerol

    NARCIS (Netherlands)

    Bonsen, P.P.M.; Haas, Gerard H. de; Deenen, L.L.M. van

    1965-01-01

    A racemic 0-alanyl ester of phosphatidyl glycerol, containing one saturated and one unsaturated fatty acid, was synthesized by a reaction between silver benzyl- (γ-oleoyl-β-palmitoyl)-Dl-[alpha]-glycerol phosphate and DL-[alpha]-iodo-B-tert.-butyl-y-(N-tert.-butoxycarbonyl)-m-alanyl glycerol. The sy

  11. Efficient utilization of crude glycerol as fermentation substrate in the synthesis of poly(3-hydroxybutyrate) biopolymers

    Science.gov (United States)

    One refined and 2 crude glycerol samples were utilized to produce poly(3-hydroxybutyrate) (PHB) by Pseudomonas oleovorans NRRL B-14682. Fermentation conditions were determined to efficiently utilize glycerol while maintaining PHB yields. A batch culture protocol including 1% glycerol and an aerati...

  12. 21 CFR 172.850 - Lactylated fatty acid esters of glycerol and propylene glycol.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Lactylated fatty acid esters of glycerol and... esters of glycerol and propylene glycol. The food additive lactylated fatty acid esters of glycerol and... additive is a mixture of esters produced by the lactylation of a product obtained by reacting edible fats...

  13. Dynamical modeling of liver Aquaporin-9 expression and glycerol permeability in hepatic glucose metabolism.

    Science.gov (United States)

    Gena, Patrizia; Buono, Nicoletta Del; D'Abbicco, Marcello; Mastrodonato, Maria; Berardi, Marco; Svelto, Maria; Lopez, Luciano; Calamita, Giuseppe

    2017-01-01

    Liver is crucial in the homeostasis of glycerol, an important metabolic intermediate. Plasma glycerol is imported by hepatocytes mainly through Aquaporin-9 (AQP9), an aquaglyceroporin channel negatively regulated by insulin in rodents. AQP9 is of critical importance in glycerol metabolism since hepatic glycerol utilization is rate-limited at the hepatocyte membrane permeation step. Glycerol kinase catalyzes the initial step for the conversion of the imported glycerol into glycerol-3-phosphate, a major substrate for de novo synthesis of glucose (gluconeogenesis) and/or triacyglycerols (lipogenesis). A model addressing the glucose-insulin system to describe the hepatic glycerol import and metabolism and the correlation with the glucose homeostasis is lacking so far. Here we consider a system of first-order ordinary differential equations delineating the relevance of hepatocyte AQP9 in liver glycerol permeability. Assuming the hepatic glycerol permeability as depending on the protein levels of AQP9, a mathematical function is designed describing the time course of the involvement of AQP9 in mouse hepatic glycerol metabolism in different nutritional states. The resulting theoretical relationship is derived fitting experimental data obtained with murine models at the fed, fasted or re-fed condition. While providing useful insights into the dynamics of liver AQP9 involvement in male rodent glycerol homeostasis our model may be adapted to the human liver serving as an important module of a whole body-model of the glucose metabolism both in health and metabolic diseases. Copyright © 2016 Elsevier GmbH. All rights reserved.

  14. The Effect of Glycerol Ingestion on Performance during Simulated Multisport Activity

    Science.gov (United States)

    Knight, Christopher; Braakhuis, Andrea; Paton, Carl

    2010-01-01

    Glycerol-induced hyperhydration has been applied to endurance sport with limited success as a performance enhancement strategy. Glycerol has been used as a hyperhydrating agent, because it has been shown to be rapidly absorbed and osmotically active; therefore, the fluid intake with glycerol is distributed throughout the body. Hyperhydration with…

  15. The Effect of Glycerol Ingestion on Performance during Simulated Multisport Activity

    Science.gov (United States)

    Knight, Christopher; Braakhuis, Andrea; Paton, Carl

    2010-01-01

    Glycerol-induced hyperhydration has been applied to endurance sport with limited success as a performance enhancement strategy. Glycerol has been used as a hyperhydrating agent, because it has been shown to be rapidly absorbed and osmotically active; therefore, the fluid intake with glycerol is distributed throughout the body. Hyperhydration with…

  16. Glycerol reforming and methanol synthesis for the production of renewable methanol

    NARCIS (Netherlands)

    van Bennekom, Joost Gerardus

    2013-01-01

    De productie van biodiesel is flink toegenomen in het eerste decennium van de 21ste eeuw. Bij de productie van 100 kg biodiesel komt ongeveer 10 kg aan glycerol vrij, wat heeft geleid tot een sterk gestegen glycerol aanbod. Een mogelijkheid om wat met de glycerol te doen, is het omzetten van glycero

  17. Glycerol fermentation to hydrogen by Thermotoga maritima: Proposed pathway and bioenergetic considerations

    NARCIS (Netherlands)

    Maru, B.T.; Bielen, A.A.M.; Constanti, M.; Medina, F.; Kengen, S.W.M.

    2013-01-01

    The production of biohydrogen from glycerol, by the hyperthermophilic bacterium Thermotoga maritima DSM 3109, was investigated in batch and chemostat systems. T. maritima converted glycerol to mainly acetate, CO2 and H2. Maximal hydrogen yields of 2.84 and 2.41 hydrogen per glycerol were observed fo

  18. Investigation of glycerol polymerization in the clinker grinding process

    NARCIS (Netherlands)

    Parvulescu, A.N.; Rossi, M.; Della Pina, C.; Ciriminna, R.; Pagliaro, M.

    2011-01-01

    Concrete production is a large scale process that involves high energy consumption. In order to increase the sustainability of this process, the reduction of energy input is necessary. Bio-glycerol was demonstrated to be a highly efficient renewable-based additive in the grinding process for concret

  19. EFFECT OF GLYCEROL SEPARATION ON PALM OIL TRANSESTERIFICATION

    Directory of Open Access Journals (Sweden)

    Budy Rahmat

    2012-12-01

    Full Text Available This research was aimed to study the effect of glycerol separation on palm oil transesterification. Objectives of this study were to suppress the use of excess methanol and shorten the processing time. This research consisted of: design-build reactor, the effect of the glycerol separation on the transesterification reaction, characterization of biodiesel, and mass balance analysis. The reactor was designed by integrating circulate stirrer pump, static mixer, and sprayer that will bring out the intense reaction in the outer tank reactor. The experiment in this research was the treatment of decreasing the quantity of methanol to 5:1 molar ratio and reducing of processing time to 20 min, which was arranged in a completely randomized factorial design. The result showed that, (i the stirring system was effectively worked outside the reactor tank, and in its reactor tank occurred glycerol separation during the process; (ii the rate of glycerol during the process followed the inverse regression equation of Ŷ = 66.44-351.17 X-1; (iii the decrease in the level of methanol to 5:1 molar ratio and the reduction of processing time to 20 min in this engineering did not influence the biodiesel yield and quality that met the SNI 04-7182-2006 standard.

  20. Comment on ``Fast dynamics of glass-forming glycerol''

    Science.gov (United States)

    Ngai, K. L.; Roland, C. M.

    1997-02-01

    The coupling model predicts the existence of a prominent fast α process at times Wuttke, Petry, Coddens, and Fujara (WPCF) [Phys. Rev. E 52, 4026 (1995)], leading to the conclusion that the fast α process is indeed quite weak therein. Thus, the coupling model predictions are fully consistent with the glycerol data, notwithstanding WPCF's statement to the contrary.

  1. Reforming of methanol and glycerol in supercritical water

    NARCIS (Netherlands)

    van Bennekom, J. G.; Venderbosch, R. H.; Assink, D.; Heeres, H. J.

    2011-01-01

    Reforming of pure glycerol, crude glycerin, and methanol (pure and in the presence of Na(2)CO(3)) in supercritical water was investigated. Continuous experiments were carried out at temperatures between 450 and 650 degrees C, residence times between 6 and 173 s, and feed concentrations of 3-20 wt%.

  2. Novel inhibitors of mitochondrial sn-glycerol 3-phosphate dehydrogenase.

    Directory of Open Access Journals (Sweden)

    Adam L Orr

    Full Text Available Mitochondrial sn-glycerol 3-phosphate dehydrogenase (mGPDH is a ubiquinone-linked enzyme in the mitochondrial inner membrane best characterized as part of the glycerol phosphate shuttle that transfers reducing equivalents from cytosolic NADH into the mitochondrial electron transport chain. Despite the widespread expression of mGPDH and the availability of mGPDH-null mice, the physiological role of this enzyme remains poorly defined in many tissues, likely because of compensatory pathways for cytosolic regeneration of NAD⁺ and mechanisms for glycerol phosphate metabolism. Here we describe a novel class of cell-permeant small-molecule inhibitors of mGPDH (iGP discovered through small-molecule screening. Structure-activity analysis identified a core benzimidazole-phenyl-succinamide structure as being essential to inhibition of mGPDH while modifications to the benzimidazole ring system modulated both potency and off-target effects. Live-cell imaging provided evidence that iGPs penetrate cellular membranes. Two compounds (iGP-1 and iGP-5 were characterized further to determine potency and selectivity and found to be mixed inhibitors with IC₅₀ and K(i values between ∼1-15 µM. These novel mGPDH inhibitors are unique tools to investigate the role of glycerol 3-phosphate metabolism in both isolated and intact systems.

  3. Novel Inhibitors of Mitochondrial sn-Glycerol 3-phosphate Dehydrogenase

    Science.gov (United States)

    Orr, Adam L.; Ashok, Deepthi; Sarantos, Melissa R.; Ng, Ryan; Shi, Tong; Gerencser, Akos A.; Hughes, Robert E.; Brand, Martin D.

    2014-01-01

    Mitochondrial sn-glycerol 3-phosphate dehydrogenase (mGPDH) is a ubiquinone-linked enzyme in the mitochondrial inner membrane best characterized as part of the glycerol phosphate shuttle that transfers reducing equivalents from cytosolic NADH into the mitochondrial electron transport chain. Despite the widespread expression of mGPDH and the availability of mGPDH-null mice, the physiological role of this enzyme remains poorly defined in many tissues, likely because of compensatory pathways for cytosolic regeneration of NAD+ and mechanisms for glycerol phosphate metabolism. Here we describe a novel class of cell-permeant small-molecule inhibitors of mGPDH (iGP) discovered through small-molecule screening. Structure-activity analysis identified a core benzimidazole-phenyl-succinamide structure as being essential to inhibition of mGPDH while modifications to the benzimidazole ring system modulated both potency and off-target effects. Live-cell imaging provided evidence that iGPs penetrate cellular membranes. Two compounds (iGP-1 and iGP-5) were characterized further to determine potency and selectivity and found to be mixed inhibitors with IC50 and Ki values between ∼1–15 µM. These novel mGPDH inhibitors are unique tools to investigate the role of glycerol 3-phosphate metabolism in both isolated and intact systems. PMID:24587137

  4. Crude glycerol combustion: particulate, acrolein, and other volatile organic emissions

    Science.gov (United States)

    Crude glycerol is an abundant by-product of biodiesel production. As volumes of this potential waste grow, there is increasing interest in developing new value added uses. One possible use, as a boiler fuel for process heating, offers added advantages of energy integration and ...

  5. Reconfigurable multiport EPON repeater

    Science.gov (United States)

    Oishi, Masayuki; Inohara, Ryo; Agata, Akira; Horiuchi, Yukio

    2009-11-01

    An extended reach EPON repeater is one of the solutions to effectively expand FTTH service areas. In this paper, we propose a reconfigurable multi-port EPON repeater for effective accommodation of multiple ODNs with a single OLT line card. The proposed repeater, which has multi-ports in both OLT and ODN sides, consists of TRs, BTRs with the CDR function and a reconfigurable electrical matrix switch, can accommodate multiple ODNs to a single OLT line card by controlling the connection of the matrix switch. Although conventional EPON repeaters require full OLT line cards to accommodate subscribers from the initial installation stage, the proposed repeater can dramatically reduce the number of required line cards especially when the number of subscribers is less than a half of the maximum registerable users per OLT. Numerical calculation results show that the extended reach EPON system with the proposed EPON repeater can save 17.5% of the initial installation cost compared with a conventional repeater, and can be less expensive than conventional systems up to the maximum subscribers especially when the percentage of ODNs in lightly-populated areas is higher.

  6. Revisiting the TALE repeat.

    Science.gov (United States)

    Deng, Dong; Yan, Chuangye; Wu, Jianping; Pan, Xiaojing; Yan, Nieng

    2014-04-01

    Transcription activator-like (TAL) effectors specifically bind to double stranded (ds) DNA through a central domain of tandem repeats. Each TAL effector (TALE) repeat comprises 33-35 amino acids and recognizes one specific DNA base through a highly variable residue at a fixed position in the repeat. Structural studies have revealed the molecular basis of DNA recognition by TALE repeats. Examination of the overall structure reveals that the basic building block of TALE protein, namely a helical hairpin, is one-helix shifted from the previously defined TALE motif. Here we wish to suggest a structure-based re-demarcation of the TALE repeat which starts with the residues that bind to the DNA backbone phosphate and concludes with the base-recognition hyper-variable residue. This new numbering system is consistent with the α-solenoid superfamily to which TALE belongs, and reflects the structural integrity of TAL effectors. In addition, it confers integral number of TALE repeats that matches the number of bound DNA bases. We then present fifteen crystal structures of engineered dHax3 variants in complex with target DNA molecules, which elucidate the structural basis for the recognition of bases adenine (A) and guanine (G) by reported or uncharacterized TALE codes. Finally, we analyzed the sequence-structure correlation of the amino acid residues within a TALE repeat. The structural analyses reported here may advance the mechanistic understanding of TALE proteins and facilitate the design of TALEN with improved affinity and specificity.

  7. Glass polymorphism in glycerol-water mixtures: II. Experimental studies.

    Science.gov (United States)

    Bachler, Johannes; Fuentes-Landete, Violeta; Jahn, David A; Wong, Jessina; Giovambattista, Nicolas; Loerting, Thomas

    2016-04-28

    We report a detailed experimental study of (i) pressure-induced transformations in glycerol-water mixtures at T = 77 K and P = 0-1.8 GPa, and (ii) heating-induced transformations of glycerol-water mixtures recovered at 1 atm and T = 77 K. Our samples are prepared by cooling the solutions at ambient pressure at various cooling rates (100 K s(-1)-10 K h(-1)) and for the whole range of glycerol mole fractions, χ(g). Depending on concentration and cooling rates, cooling leads to samples containing amorphous ice (χg ≥ 0.20), ice (χ(g) ≤ 0.32), and/or "distorted ice" (0 density amorphous ice (HDA). PIA of ice domains within the glycerol-water mixtures is shown to be possible only up to χ(g) ≈ 0.32 (T = 77 K). This is rather surprising since it has been known that at χ(g) solution of χ(g) ≈ 0.38. Accordingly, in the range 0.32 density amorphous ice) transformation. At 0.15 glycerol-water domains and, finally, the melting of ice at high temperatures. Our work exemplifies the complex "phase" behavior of glassy binary mixtures due to phase-separation (ice formation) and polyamorphism, and the relevance of sample preparation, concentration as well as cooling rates. The presence of the distorted ice (called "interphase" by us) also explains the debated "drift anomaly" upon melting. These results are compatible with the high-pressure study by Suzuki and Mishima indicating disappearance of polyamorphism at P ≈ 0.03-0.05 GPa at χ(g) ≈ 0.12-0.15 [J. Chem. Phys., 2014, 141, 094505].

  8. Recursive quantum repeater networks

    CERN Document Server

    Van Meter, Rodney; Horsman, Clare

    2011-01-01

    Internet-scale quantum repeater networks will be heterogeneous in physical technology, repeater functionality, and management. The classical control necessary to use the network will therefore face similar issues as Internet data transmission. Many scalability and management problems that arose during the development of the Internet might have been solved in a more uniform fashion, improving flexibility and reducing redundant engineering effort. Quantum repeater network development is currently at the stage where we risk similar duplication when separate systems are combined. We propose a unifying framework that can be used with all existing repeater designs. We introduce the notion of a Quantum Recursive Network Architecture, developed from the emerging classical concept of 'recursive networks', extending recursive mechanisms from a focus on data forwarding to a more general distributed computing request framework. Recursion abstracts independent transit networks as single relay nodes, unifies software layer...

  9. Comparison and Combination of Solvent Extraction and Adsorption for Crude Glycerol Enrichment

    OpenAIRE

    Hunsom, Mali; Saila, Payia; Chaiyakam, Penpisuth; Kositnan, Winata

    2016-01-01

    A comparative study of enrichment of crude glycerol via solvent extraction and adsorption was performed at a laboratory scale at ambient temperature (30 oC). Effect of various parameters on the properties of the obtained glycerol including glycerol-, ash- and contaminant contents and color, was explored. The results showed that the enrichment of glycerol by solvent extraction was significantly affected by the solvent type and ratio of solvent to pre-treated crude glycerol. The use of n-C3H7OH...

  10. Value-added uses for crude glycerol--a byproduct of biodiesel production

    Directory of Open Access Journals (Sweden)

    Yang Fangxia

    2012-03-01

    Full Text Available Abstract Biodiesel is a promising alternative, and renewable, fuel. As its production increases, so does production of the principle co-product, crude glycerol. The effective utilization of crude glycerol will contribute to the viability of biodiesel. In this review, composition and quality factors of crude glycerol are discussed. The value-added utilization opportunities of crude glycerol are reviewed. The majority of crude glycerol is used as feedstock for production of other value-added chemicals, followed by animal feeds.

  11. Effects of Glycerol in the Refolding and Unfolding of Creatine Kinase

    Institute of Scientific and Technical Information of China (English)

    欧文斌; 朴龙斗; 孟凡国; 周海梦

    2002-01-01

    The effects of glycerol in the refolding, reactivation, unfolding, and inactivation of guanidine- denatured creatine kinase were studied by observing the fluorescence emission spectra and the circular dichroism spectra, and by recovery and inactivation of enzymatic activity and aggregation. The results show that low concentrations of glycerol (<25%) improve the refolding yields of creatine kinase, but high glycerol concentrations decrease its recovery. Glycerol favors the secondary structural formation and inhibits aggregation of creatine kinase as proline does. These systematic observations further support the suggestion that low concentrations of glycerol possibly play a chaperone role in the refolding of creatine kinase. In addition, glycerol reduces the inactivation and unfolding rate of creatine kinase, increases the change in transition free energy of unfolding (ΔΔGu) and stabilizes its active conformation relative to the partially unfolded state with no glycerol. In the presence of glycerol, the inactivation and unfolding dynamics of creatine kinase are related to glycerol concentrations. Glycerol blocks the exposure of hydrophobic areas and the dissociation of dimers, and protects creatine kinase against guanidine denaturation in a concentration-dependent manner. This study suggests that glycerol as an energy substrate for metabolism and organic components in vivo, assists correct protein folding, maintains adequate rates of enzymatic catalysis and stabilizes the protein secondary and tertiary conformations.

  12. Selective lumbosacral posterior and anterior rhizotomy for mixed cerebral palsy%选择性腰骶脊神经后根+前根切断术治疗混合型脑瘫

    Institute of Scientific and Technical Information of China (English)

    王逢贤; 徐林; 曹旭; 俞兴; 穆晓红; 吴坤懂

    2012-01-01

    Objectives: To investigate the efficacy of selective posterior rhizotomy(SPR) with selective anterior rhizotomy (SAR) for the treatment of mixed cerebral palsy. Methods: 48 patients with an average age of 8.8 years old(3-22 years) were reviewed retrospectively from January 2004 to January 2010. There were 36 males and 12 females. All cases had mixed cerebral palsy, and all patients presented with spasm compliacted with lower limb athetosis, the muscular tension according to Ashworth spasticity scale was grade 3. Preopera-tive lower limb dysfunction included: walking independently in 36 cases, walking with assistance in 8 cases and standing with assistance in 4 cases. SPR with SAR was applied in all cases. The L5 and SI posterior roots in 38 cases and L4, L5 and SI posterior roots in 10 cases were cut off partly in accordance with the degree of lower limb spasticity by preoperativc physical exam. 30-50 percent of the posterior nerve roots were cut off. The L5 anterior roots in 28 cases and S1 anterior roots in 20 cases were cut off partly in accordance with the degree of athetosis. 30 percent of the anterior nerve roots were cut off. Laminae were maintained as far as possible so as not to violate the stability of spine. Results: Postoperative leg or foot numbness were noted in 2 cases, lower limb weakness in 3 cases, low back pain in 2 cases, lower back weakness in 5 cases, urine dysfunction in 1 case, all these were resolved by the corresponding intervention in six months. The average follow-up was 18 months, 48 cases with muscle tension at 1 week, 6 months, 18 months after operation improved significantly compared with preopeiation, and the spasm relief rate reached 100%. As for the lower limb athctosis: after 1 week, deterioration was noted in 1 case, which was controlled satisfactively after administration of sedative drugs and baclofen; unchanged in 4, and excellent in 43 cases; after 6 months, unchanged in 5 cases and excellent in 43 cases, no case was noted

  13. Endoscopic dorsal rhizotomy for chronic lumbar zygapophyseal joint originated pain%内窥镜下脊神经背内侧支切断术治疗腰椎关节突关节源性慢性腰痛

    Institute of Scientific and Technical Information of China (English)

    李振宙; 侯树勋; 商卫林; 宋科冉; 吴闻文

    2013-01-01

    Objectives: To prospectively investigate the clinical outcome of endoscopic dorsal rhizotomy (endoscopic lumbar medial branch neurotomy) for chronic lumbar zygapophyseal joint originated pain. Methods: From April 2011 to October 2011, 58 patients with chronic low back pain were determined as chronic lumbar zygapophyseal joint originated pain by more than 80% pain relief after controlled differential(double) medial branch block (MBB) with lidocaine and bupivacaine respectively. 45 cases underwent endoscopic dorsal rhizotomy(operation group), while 13 cases underwent conservative treatment, including NSAIDs, physical therapy and recognition therapy (conservative group). The VAS scores of low back pain and referred pain were recorded at each time point, including VAS scores before MBB, after MBB, Id, 3 months, 6 months and 12 months postoperatively. MacNab scores were evaluated at 12 month follow-up. The clinical outcomes of endoscopic dorsal rhizotomy and conservative treatment were analyzed and compared. Results: In operation group, postoperative VAS scores of low back pain and referred pain significantly decreased compared with those before MBB (P0.05). In conservative group, VAS scores of low back pain and referred pain after treatment decreased significantly compared with that before MBB(P<0.05) and were significantly higher than those after MBB(P<0.05). The rate of pain relief in operation group was significantly higher than that in conservative group(P<0.01). MacNab scores of 1 year follow-up included 27 excellent, 17 good, 1 fair in operation group and 6 fair, 7 poor in conservative group respectively. Conclusions: Endoscopic dorsal rhizotomy is safe and effective for chronic lumbar zygapophyseal joint originated pain, which is superior over conservative treatment.%目的:探讨内窥镜下脊神经背内侧支切断术治疗腰椎关节突关节源性慢性腰痛的效果.方法:2011年4月~2011年10月,收治58例分别使用利多卡因和布比卡因行

  14. Adipose tissue lipolysis is increased during a repeated bout of aerobic exercise.

    Science.gov (United States)

    Stich, V; de Glisezinski, I; Berlan, M; Bulow, J; Galitzky, J; Harant, I; Suljkovicova, H; Lafontan, M; Rivière, D; Crampes, F

    2000-04-01

    The goal of the study was to examine whether lipid mobilization from adipose tissue undergoes changes during repeated bouts of prolonged aerobic exercise. Microdialysis of the subcutaneous adipose tissue was used for the assessment of lipolysis; glycerol concentration was measured in the dialysate leaving the adipose tissue. Seven male subjects performed two repeated bouts of 60-min exercise at 50% of their maximal aerobic power, separated by a 60-min recovery period. The exercise-induced increases in extracellular glycerol concentrations in adipose tissue and in plasma glycerol concentrations were significantly higher during the second exercise bout compared with the first (P < 0.05). The responses of plasma nonesterified fatty acids and plasma epinephrine were higher during the second exercise bout, whereas the response of norepinephrine was unchanged and that of growth hormone lower. Plasma insulin levels were lower during the second exercise bout. The results suggest that adipose tissue lipolysis during aerobic exercise of moderate intensity is enhanced when an exercise bout is preceded by exercise of the same intensity and duration performed 1 h before. This response pattern is associated with an increase in the exercise-induced rise of epinephrine and with lower plasma insulin values during the repeated exercise bout.

  15. Comparison of Different Strategies for Selection/Adaptation of Mixed Microbial Cultures Able to Ferment Crude Glycerol Derived from Second-Generation Biodiesel

    DEFF Research Database (Denmark)

    Varrone, Cristiano; Heggeset, T. M. B.; Le, S. B.

    2015-01-01

    Objective of this study was the selection and adaptation of mixed microbial cultures (MMCs), able to ferment crude glycerol generated from animal fat-based biodiesel and produce building-blocks and green chemicals. Various adaptation strategies have been investigated for the enrichment of suitable...... and stable MMC, trying to overcome inhibition problems and enhance substrate degradation efficiency, as well as generation of soluble fermentation products. Repeated transfers in small batches and fed-batch conditions have been applied, comparing the use of different inoculum, growth media, and Kinetic...... Control. The adaptation of activated sludge inoculum was performed successfully and continued unhindered for several months. The best results showed a substrate degradation efficiency of almost 100% (about 10 g/L glycerol in 21 h) and different dominant metabolic products were obtained, depending...

  16. Biomass Pretreatment using Ionic Liquid and Glycerol Mixtures

    Science.gov (United States)

    Lynam, Joan Goerss

    Lignocellulosic biomass is a renewable, sustainable resource that can replace or supplement fossil fuels use for liquid fuels and chemicals. However, its recalcitrant structure including interwoven cellulose, hemicelluloses, and lignin biomacromolecules is challenging to deconstruct. Pretreating biomass so that it can be converted to useful liquids dominates process economics. Many pretreatment methods exist, but most require hazardous chemicals or processing conditions. Many ionic liquids (ILs), salts molten below 100°C, can be used to deconstruct lignocellulosic biomass and are less hazardous than the volatile organic compounds typically used. While effective, relatively safe, and recyclable, ILs are expensive. To reduce costs, dilution with other safe compounds is desirable, if there is no impact on deconstruction efficiency. Glycerol, a food additive, is inexpensive and becoming even more so since it is a by-product of the burgeoning biodiesel industry. Use of glycerol as an additive or diluent for ILs is extensively evaluated in this work. Rice hulls are an abundant biomass, with over 100 million tons produced per year, but with little practical use. The IL 1-ethyl-3-methylimidazolium formate ([C2mim][O2CH] or EMIM Form) when mixed with an equal amount of glycerol has been shown to be effective in pretreating rice hulls. Ambient pressure, a pretreatment temperature of 110°C, and a reaction time of three hours produced rice hulls that could be enzymatically hydrolyzed to give reasonably good glucose and xylose yields considering the recalcitrance of this silica-armored biomass. The IL [C2mim][O2CH] was also effective when mixed with an equal amount of glycerol to pretreat loblolly pine, a fast-growing softwood. Loblolly pine was pretreated at 140°C for three hours to produce a solid rich in cellulose and hemicelluloses, while a lignin-rich product could be precipitated from the IL. Similar products were obtained from pretreatment with a mixture of 75% 1

  17. Modified silica-based heterogeneous catalysts for etherification of glycerol

    Energy Technology Data Exchange (ETDEWEB)

    Gholami, Zahra, E-mail: zahra.gholami@petronas.com.my [Centralized Analytical Laboratory, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750 Tronoh, Perak (Malaysia); Abdullah, Ahmad Zuhairi, E-mail: chzuhairi@usm.my; Gholami, Fatemeh, E-mail: fgholami59@gmail.com [School of Chemical Engineering, Universiti Sains Malaysia, Engineering Campus,14300 Nibong Tebal, Penang (Malaysia); Vakili, Mohammadtaghi, E-mail: farshid3601@gmail.com [School of Industrial Technology, Universiti Sains Malaysia, 11800 Penang (Malaysia)

    2015-07-22

    The advent of mesoporous silicas such as MCM-41 has provided new opportunities for research into supported metal catalysis. The loading of metals into framework structures and particularly into the pores of porous molecular sieves, has long been of interest because of their potential catalytic activity. Stable heterogeneous mesoporous basic catalysts were synthesized by wet impregnation of MCM-41 with calcium nitrate and lanthanum nitrate. The surface and structural properties of the prepared catalysts were characterized using BET surface analysis, SEM and TEM. MCM-41 and modified MCM-41 were used in the solventless etherification of glycerol to produce diglycerol as the desired product. The reaction was performed at 250 °C for 8 h, and catalyst activity was evaluated. Catalytic etherification over the 20%Ca{sub 1.6}La{sub 0.6}/MCM-41 catalyst resulted in the highest glycerol conversion of 91% and diglycerol yield of 43%.

  18. PROPERTIES OF THERMO-MOLDED GLUTEN/GLYCEROL/SILICA COMPOSITES

    Institute of Scientific and Technical Information of China (English)

    Yi-hu Song; Qiang Zheng; Zheng-zheng Lai

    2008-01-01

    Environmentally friendly thermosetting composites were successfully prepared by conventional blending wheat gluten as matrix.glycerol as plasticizer and silica as filler followed by thermo-molding of the mixture at 120℃.The strong interfacial interaction between silica particles and gluten proteins leaded to an increase in storage modulus and a decrease in loss factor as revealed by dynamic mechanical analysis.The moisture absorption and elongation at break decrease while Young's modulus and tensile strength increase with increasing silica content from 0 to 10 wt%.However,the moisture absorption and mechanical properties show discontinuous changes at a silica content of 6 wt%.The glycerol content also has a marked influence on the moisture absorption and mechanical properties of the composites with a constant gluten-to-silica ratio.

  19. Sodahvede og glycerol til malkekøer

    DEFF Research Database (Denmark)

    Hvelplund, Torben; Weisbjerg, Martin Riis

    2011-01-01

    Et fodringsforsøg på Kvægbrugets Forsøgscenter har vist, at glycerol kan anvendes som et alternativt fodermiddel til højtydende malkekøer. De anvendte mængder gav dog en lavere EKM ydelse end sodahvede, men øgede samtidigt mælkens proteinindhold.......Et fodringsforsøg på Kvægbrugets Forsøgscenter har vist, at glycerol kan anvendes som et alternativt fodermiddel til højtydende malkekøer. De anvendte mængder gav dog en lavere EKM ydelse end sodahvede, men øgede samtidigt mælkens proteinindhold....

  20. The Pentapeptide Repeat Proteins

    Energy Technology Data Exchange (ETDEWEB)

    Vetting,M.; Hegde, S.; Fajardo, J.; Fiser, A.; Roderick, S.; Takiff, H.; Blanchard, J.

    2006-01-01

    The Pentapeptide Repeat Protein (PRP) family has over 500 members in the prokaryotic and eukaryotic kingdoms. These proteins are composed of, or contain domains composed of, tandemly repeated amino acid sequences with a consensus sequence of [S, T,A, V][D, N][L, F]-[S, T,R][G]. The biochemical function of the vast majority of PRP family members is unknown. The three-dimensional structure of the first member of the PRP family was determined for the fluoroquinolone resistance protein (MfpA) from Mycobacterium tuberculosis. The structure revealed that the pentapeptide repeats encode the folding of a novel right-handed quadrilateral {beta}-helix. MfpA binds to DNA gyrase and inhibits its activity. The rod-shaped, dimeric protein exhibits remarkable size, shape and electrostatic similarity to DNA.

  1. MACROSCOPIC KINETIC MODELS OF GLYCEROL BATCH FERMENTATION WITH OSMOTOLERANT YEAST

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    l introductionGlycerol production by fermentation has beenwidely investigated to meet the great commercialdemand in last decades and osmotolerant yeast wasthe microorganism studied most. To analyze thefermentation process more efficiently, a kinetic modelshould be established but little works about it werereported because of its complicated metabolism ofglycerol [1-3]. Batch fermentation experiment showedthat low glucose concentration in the latterfermentation stage resulted in decrease in both glucoseconsu...

  2. Adjuvant properties of a simplified C32 monomycolyl glycerol analogue.

    Science.gov (United States)

    Bhowruth, Veemal; Minnikin, David E; Agger, Else Marie; Andersen, Peter; Bramwell, Vincent W; Perrie, Yvonne; Besra, Gurdyal S

    2009-04-01

    A simplified C(32) monomycolyl glycerol (MMG) analogue demonstrated enhanced immunostimulatory activity in a dioctadecyl ammonium bromide (DDA)/Ag85B-ESAT-6 formulation. Elevated levels of IFN-gamma and IL-6 were produced in spleen cells from mice immunised with a C(32) MMG analogue comparable activity to the potent Th1 adjuvant, trehalose 6,6'-di-behenate (TDB).

  3. Study of shellac glycerol esters as microencapsulating materials.

    Science.gov (United States)

    Labhasetwar, V D; Puranik, P K; Dorle, A K

    1989-01-01

    Shellac esters were prepared by heating shellac with glycerol and intermediate reaction products were withdrawn. Salicyclic acid granules were encapsulated using a 20 per cent w/v alcoholic solution of shellac and shellac esters. The coated microcapsules were evaluated for moisture absorption, flow properties, and dissolution studies. The drug release from coated granules was seen to depend upon the acid value of the esters. Results indicate that shellac esters could be better encapsulating material than shellac in sustained release formulation.

  4. Repeating the Past

    Science.gov (United States)

    Moore, John W.

    1998-05-01

    As part of the celebration of the Journal 's 75th year, we are scanning each Journal issue from 25, 50, and 74 years ago. Many of the ideas and practices described are so similar to present-day "innovations" that George Santayana's adage (1) "Those who cannot remember the past are condemned to repeat it" comes to mind. But perhaps "condemned" is too strong - sometimes it may be valuable to repeat something that was done long ago. One example comes from the earliest days of the Division of Chemical Education and of the Journal.

  5. Bio-Propane from glycerol for biogas addition

    Energy Technology Data Exchange (ETDEWEB)

    Brandin, Jan; Hulteberg, Christian; Liljegren Nilsson, Andreas (Biofuel-Solution AB, Malmoe (Sweden))

    2008-11-15

    In this report, the technical and economical feasibility to produce higher alkanes from bioglycerol has been investigated. The main purpose of producing this kind of chemicals would be to replace the fossil LPG used in upgraded biogas production. When producing biogas and exporting it to the natural gas grid, the Wobbe index and heating value does not match the existing natural gas. Therefore, the upgraded biogas that is put into the natural gas grid in Sweden today contains 8-10 vol-% of LPG. The experimental work performed in association to this report has shown that it is possible to produce propane from glycerol. However, the production of ethane from glycerol may be even more advantageous. The experimental work has included developing and testing catalysts for several intermediate reactions. The work was performed using different micro-scale reactors with a liquid feed rate of 18 g/h. The first reaction, independent on if propane or ethane is to be produced, is dehydration of glycerol to acrolein. This was showed during 60 h on an acidic catalyst with a yield of 90%. The production of propanol, the second intermediate to producing propane, was shown as well. Propanol was produced both using acrolein as the starting material as well as glycerol (combining the first and second step) with yields of 70-80% in the first case and 65-70% in the second case. The propanol produced was investigated for its dehydration to propene, with a yield of 70-75%. By using a proprietary, purposely developed catalyst the propene was hydrogenated to propane, with a yield of 85% from propanol. The formation of propane from glycerol was finally investigated, with an overall yield of 55%. The second part of the experimental work performed investigated the possibilities of decarbonylating acrolein to form ethane. This was made possible by the development of a proprietary catalyst which combines decarbonylation and water-gas shift functionality. By combining these two functionalities, no

  6. Enhanced succinate production from glycerol by engineered Escherichia coli strains.

    Science.gov (United States)

    Li, Qing; Wu, Hui; Li, Zhimin; Ye, Qin

    2016-10-01

    In this study, an engineered strain Escherichia coli MLB (ldhA(-)pflB(-)) was constructed for production of succinate from glycerol. The succinate yield was 0.37mol/mol in anaerobic culture, however, the growth and glycerol consumption rates were very slow, resulting in a low succinate level. Two-stage fermentation was performed in flasks, and the succinate yield reached 0.93mol/mol, but the succinate titer was still low. Hence, overexpression of malate dehydrogenase, malic enzyme, phosphoenolpyruvate (PEP) carboxylase and PEP carboxykinase (PCK) from E. coli, and pyruvate carboxylase from Corynebacterium glutamicum in MLB was investigated for improving succinate production. Overexpression of PCK resulted in remarkable enhancement of glycerol consumption and succinate production. In flask experiments, the succinate concentration reached 118.1mM, and in a 1.5-L bioreactor the succinate concentration further increased to 360.2mM. The highest succinate yield achieved 0.93mol/mol, which was 93% of the theoretical yield, in the anaerobic stage.

  7. Metabolic Flexibility of Yarrowia lipolytica Growing on Glycerol

    Science.gov (United States)

    Egermeier, Michael; Russmayer, Hannes; Sauer, Michael; Marx, Hans

    2017-01-01

    The yeast Yarrowia lipolytica is a fascinating microorganism with an amazing metabolic flexibility. This yeast grows very well on a wide variety of carbon sources from alkanes over lipids, to sugars and glycerol. Y. lipolytica accumulates a wide array of industrially relevant metabolites. It is very tolerant to many environmental factors, above all the pH value. It grows perfectly well over a wide pH range, but it has been described, that the pH has a decisive influence on the metabolite pattern accumulated by this yeast. Here, we set out to characterize the metabolism of different Y. lipolytica strains, isolated from various environments, growing on glycerol at different pH values. The conditions applied for strain characterization are of utmost importance. Shake flask cultures lead to very different results, when compared to controlled conditions in bioreactors regarding pH and aeration. Only one of the tested strains was able to accumulate high amounts of citric acid in shake flask experiments, whereas a group of six strains turned out to accumulate citric acid efficiently under controlled conditions. The present study shows that strains isolated from dairy products predominantly accumulate sugar alcohols at any given pH, when grown on glycerol under nitrogen-limitation. PMID:28174563

  8. Studies on Freezing RAM Semen in Absence of Glycerol.

    Science.gov (United States)

    Abdelnaby, Abdelhady Abdelhakeam

    1988-12-01

    Glycerol is widely used as a major cryoprotective agent for freezing spermatozoa of almost all species. However, it reduces fertility of sheep inseminated cervically compared with intrauterine insemination. Studies were conducted to develop a method and procedure for freezing ram semen in the absence of glycerol. Post -thaw survival of ram spermatozoa frozen in the absence of glycerol was affected by time and temperature after collection and before dilution and time after dilution and before freezing. Increase in time at 5^ circC before or after dilution and before freezing increased both post-thaw motility and number of cells passing through Sephadex filter. A cold dilution method was developed. Slow cooling of fresh ram semen and diluting at 5^circ C 2-3 hr. after collection, then freezing 1 hr. after dilution improved both post-thaw motility and number of cells passing through Sephadex filter compared with immediate dilution at 30-37^circC after collection and freezing 3-4 hr. later (P synchronization during breeding season resulted in higher heat response and lambing rate than two injections given 10 days apart.

  9. Impact of riverine suspended particulate matter on the branched glycerol dialkyl glycerol tetraether composition of lakes: The outflow of the Selenga River in Lake Baikal (Russia)

    NARCIS (Netherlands)

    De Jonge, C.; Stadnitskaia, A.; Fedotov, A.; Sinninghe Damsté, J.S.

    2015-01-01

    Branched glycerol dialkyl glycerol tetraethers (brGDGTs) are bacterial membrane lipids found in several environments, including soils, rivers and lakes, whose distribution varies with temperature and pH, although this dependence is apparently not the same for the different environments. Mixing of

  10. Impact of riverine suspended particulate matter on the branched glycerol dialkyl glycerol tetraether composition of lakes : The outflow of the Selenga River in Lake Baikal (Russia)

    NARCIS (Netherlands)

    De Jonge, C.|info:eu-repo/dai/nl/371751187; Stadnitskaia, A.N.; Fedotov, Andrey; Sinninghe Damste, J.S.|info:eu-repo/dai/nl/07401370X

    Branched glycerol dialkyl glycerol tetraethers (brGDGTs) are bacterial membrane lipids found in several environments, including soils, rivers and lakes, whose distribution varies with temperature and pH, although this dependence is apparently not the same for the different environments. Mixing of

  11. A thermodynamic study of 1-propanol-glycerol-H2O at 25 degrees C: Effect of glycerol on molecular organization of H2O

    DEFF Research Database (Denmark)

    Parsons, M.T.; Westh, Peter; Davies, J.V.

    2001-01-01

    The excess chemical potential, partial molar enthalpy, and volume of 1-propanol were determined in ternary mixtures of 1-propanol-glycerol-H2O at 25degreesC. The mole fraction dependence of all these thermodynamic functions was used to elucidate the effect of glycerol on the molecular organization...

  12. Regulation of glycerol metabolism in Enterobacter aerogenes NBRC12010 under electrochemical conditions.

    Science.gov (United States)

    Hatayama, Kouta; Yagishita, Tatsuo

    2009-06-01

    Enterobacter aerogenes NBRC12010 was able to ferment glycerol to ethanol and hydrogen gas. Fermentation of glycerol ceased in the stationary phase of growth, and it was activated by electrochemical reactions using thionine as an electron transfer mediator from bacterial cells to an electrode. Using resting cells of E. aerogenes NBRC12010 in only citrate buffer solution, the cells did not consume glycerol at all, but they could metabolize glucose. These results suggest that the regulation of glycerol metabolism occurred at enzymatic steps before glycolysis. In E. aerogenes NBRC12010, glycerol was metabolized via glycerol dehydrogenase (GDH) and then dehydroxyacetone kinase. The GDH-catalyzed reaction mainly depended on the ratio of NAD(+)/NADH. At a NAD(+)/NADH ratio of nearly 1 or less, it was substantially suppressed and glycerol metabolism stopped. When the ratio was higher than 1, GDH was activated and glycerol was metabolized. Thus, the reaction of glycerol metabolism depended on the balance of cellular NAD(+)/NADH. Exogenous NADH was oxidized to NAD(+) by electrochemical reactions with thionine. We proposed the activation mechanism of glycerol metabolism under electrochemical conditions.

  13. Enhanced hydrogen and 1,3-propanediol production from glycerol by fermentation using mixed cultures

    KAUST Repository

    Selembo, Priscilla A.

    2009-12-15

    The conversion of glycerol into high value products, such as hydrogen gas and 1,3-propanediol (PD), was examined using anaerobic fermentation with heat-treated mixed cultures. Glycerol fermentation produced 0.28 mol-H 2/mol-glycerol (72 mL-H2/g-COD) and 0.69 mol-PD/mol-glycerol. Glucose fermentation using the same mixed cultures produced more hydrogen gas (1.06 mol-H2/mol-glucose) but no PD. Changing the source of inoculum affected gas production likely due to prior acclimation of bacteria to this type of substrate. Fermentation of the glycerol produced from biodiesel fuel production (70% glycerol content) produced 0.31 mol-H 2/mol-glycerol (43 mL H2/g-COD) and 0.59 mol-PD/mol-glycerol. These are the highest yields yet reported for both hydrogen and 1,3-propanediol production from pure glycerol and the glycerol byproduct from biodiesel fuel production by fermentation using mixed cultures. These results demonstrate that production of biodiesel can be combined with production of hydrogen and 1,3-propanediol for maximum utilization of resources and minimization of waste. © 2009 Wiley Periodicals, Inc.

  14. Enhancement of glycerol utilization ability of Ralstonia eutropha H16 for production of polyhydroxyalkanoates.

    Science.gov (United States)

    Fukui, Toshiaki; Mukoyama, Masaharu; Orita, Izumi; Nakamura, Satoshi

    2014-09-01

    Ralstonia eutropha H16 is a well-studied bacterium with respect to biosynthesis of polyhydroxyalkanoates (PHAs), which has attracted attentions as biodegradable bio-based plastics. However, this strain shows quite poor growth on glycerol of which bulk supply has been increasing as a major by-product of biodiesel industries. This study examined enhancement of glycerol assimilation ability of R. eutropha H16 by introduction of the genes of aquaglyceroporin (glpF) and glycerol kinase (glpK) from Escherichia coli. Although introduction of glpFK Ec into the strain H16 using a multi-copy vector was not successful, a recombinant strain possessing glpFK Ec within the chromosome showed much faster growth on glycerol than H16. Further analyses clarified that weak expression of glpK Ec alone allowed to establish efficient glycerol assimilation pathway, indicating that the poor growth of H16 on glycerol was caused by insufficient kination activity to glycerol, as well as this strain had a potential ability for uptake of extracellular glycerol. The engineered strains expressing glpFK Ec or glpK Ec produced large amounts of poly[(R)-3-hydroxybutyrate] [P(3HB)] from glycerol with much higher productivity than H16. Unlike other glycerol-utilizable wild strains of R. eutropha, the H16-derived engineered strains accumulated P(3HB) with no significant decrease in molecular weights on glycerol, and the polydispersity index of the glycerol-based P(3HB) synthesized by the strains expressing glpFK Ec was lower than those by the parent strains. The present study demonstrated possibility of R. eutropha H16-based platform for production of useful compounds from inexpensive glycerol.

  15. Research note: investigation on the metabolism of glycerol in the rumen of bulls.

    Science.gov (United States)

    Kijora, C; Bergner, H; Götz, K P; Bartelt, J; Szakács, J; Sommer, A

    1998-01-01

    Two bulls, each fitted with rumen and duodenal cannulas, received (in addition to a hay-grain diet) twice daily an infusion of 200 g glycerol into the rumen over a period of six days. During this preliminary in vivo investigation, the influence of a glycerol application on the rumen environment over a six-day adaptation period was examined. Samples of rumen fluid were collected daily, two hours after glycerol infusion. An additional 15N-urea application into the rumen was given on days 1 (without glycerol infusion), 3 and 7 (with glycerol infusion). Extra samples of rumen fluid and blood plasma (from puncture of vena jungularis) were taken through the 12th hour following urea application. Rumen fluid pH was reduced due to glycerol intake from 6.3 (day 1, without glycerol) to 5.4 by day 7. Molar proportion of acetic acid to propionic acid decreased from 3.5 (day 1) to 2.1 (days 6 and 7). Average glycerol disappearance rate from the rumen was 4.7 gl-1 h-1 for the first hour. Only small amounts of glycerol could be detected in the duodenal digesta. Blood plasma glycerol content was significantly higher after glycerol application (0.061 mmol l-1 vs. 0.019 mmol l-1). The incorporation of 15N into the rumen bacteria and the proportion of bacterial N (as percent of TCA-precipitable N in the rumen fluid) were lower after glycerol influsion. These results, coupled with the lower concentration of iso-acids (isobutyric and isovaleric acids) in the rumen fluid, indicate that the high amount of glycerol infusion (10% of DMI) reduced protein metabolism of rumen bacteria throughout the experimental period.

  16. Possibility of analytical finding of glycerol caused by self-catheterization in doping control.

    Science.gov (United States)

    Okano, Masato; Nishitani, Yasunori; Kageyama, Shinji

    2014-01-01

    Glycerol is listed on the World Anti-Doping Agency (WADA) prohibited list as a masking agent principally because the administration of glycerol increases plasma volume and decreases the concentration of haemoglobin and the value of haematocrit in blood. Glycerol is a naturally occurring substance; therefore, the threshold is set as 1.0 mg/mL in the WADA technical document (WADA TD2013DL). In a WADA-accredited doping control laboratory, three doping control urine specimens collected from impaired athletes were determined to contain a high concentration of glycerol (>1.0 mg/mL); two of these specimens were considered adverse analytical findings (AAFs). Self-catheterization is necessary for athletes with neurological disorders such as neurogenic bladder dysfunction. We conducted a simple simulation of self-catheterization as an experimental test using urethral catheters with an antiseptic agent containing glycerol to confirm the influence of this antiseptic agent on the quantitative value of glycerol in doping control analysis. Some users employ a catheter with glycerol solution (ca. 1 mL) to avoid pain during use. The urine sample passed through such a catheter exhibited a glycerol concentration (4.94 mg/mL) greater than the threshold level. In September 2014, the threshold for glycerol will change from 1.0 to 4.3 mg/mL (WADA TD2014DL); however, a possibility exists for the quantitative value of glycerol in doping control analysis to exceed the threshold because of the use of an antiseptic agent containing glycerol for self-catheterization. The AAF for glycerol for impaired athletes, particularly those who participate in Paralympic sports, should account for the use of a catheter with glycerol.

  17. All-optical repeater.

    Science.gov (United States)

    Silberberg, Y

    1986-06-01

    An all-optical device containing saturable gain, saturable loss, and unsaturable loss is shown to transform weak, distorted optical pulses into uniform standard-shape pulses. The proposed device performs thresholding, amplification, and pulse shaping as required from an optical repeater. It is shown that such a device could be realized by existing semiconductor technology.

  18. Bidirectional Manchester repeater

    Science.gov (United States)

    Ferguson, J.

    1980-01-01

    Bidirectional Manchester repeater is inserted at periodic intervals along single bidirectional twisted pair transmission line to detect, amplify, and transmit bidirectional Manchester 11 code signals. Requiring only 18 TTL 7400 series IC's, some line receivers and drivers, and handful of passive components, circuit is simple and relatively inexpensive to build.

  19. The anesthesia for selective posterior rhizotomy at lumbar and sacral regions on juvenile cerebral palsy patients%小儿脑性瘫痪患者腰骶段选择性后根神经切断术的麻醉处理

    Institute of Scientific and Technical Information of China (English)

    王强; 王增春

    2002-01-01

    Objective To summarize the anesthesia techniques performed in the selective posterior rhizotomy(SPR) at lumbar and sacral regions( L& R) on juvenile cerebral palsy(CP) patients. Method 144 CP patients below 10 years were successfully erformed SPR at L& R under combined intravenous and inhalation anesthesia (CIIA) in prone position with threshold values of each nerve root being measured by means of nerve root electric stimulus (NRES). Result All patients were performed SPR and NRES successfully although blood pressure and heart rate increased significantly while NRES. Conclusion CIIA is safe and effective for juvenile CP patients to be performed SPR at L& R.

  20. Influence of heat shock-treated cells on the production of glycerol and other metabolites in alcoholic fermentation

    Directory of Open Access Journals (Sweden)

    Sofoklis Petropoulos

    2010-11-01

    Full Text Available Sofoklis Petropoulos1,2, Paul R Grbin2, Vladimir Jiranek21SEMELI SA, Stamata Attica, Greece; 1,2School of Agriculture, Food and Wine, The University of Adelaide, South Australia, AustraliaAbstract: The impact of heat shock on the formation of sensorily important fermentation metabolites was investigated. Initially the heat tolerance of six commercial Saccharomyces cerevisiae yeast strains was evaluated under various conditions of time and temperature (heat shock at 40°C, 50°C, and 60°C for a duration of 20, 40, and 60 minutes, respectively. A chemically defined grape juice medium was inoculated from the surviving colonies, and microferments were conducted. Two strains were selected for further evaluation due to their heat shock tolerance and enhanced glycerol production. The experiment was repeated in standard laboratory scale fermentations under aerobic and anaerobic conditions, and the medium was inoculated directly after the heat shock treatment and after recovery from the heat shock on yeast peptone dextrose plates. All fermentations were further analyzed for higher alcohol, organic acid, and ethyl ester content using gas chromatography mass spectrometry. Elevated glycerol production (increase of 17% under aerobic conditions and 8% under anaerobic conditions was reported only in one strain and only after direct inoculation of the fermentation medium. With both strains, direct inoculation of the heated cells caused a 2-day delay in the commencement of the fermentation, but after recovery, the fermentation progress was increased. Volatile analysis showed that apart from changes in organic acids, all other volatile compounds analyzed exhibited an alteration mainly due to strain differences and the presence of oxygen.Keywords: heat shock, glycerol, higher alcohols, wine, Saccharomyces

  1. Dielectric and specific heat relaxations in vapor deposited glycerol

    Energy Technology Data Exchange (ETDEWEB)

    Kasina, A., E-mail: angeline.kasina@fys.kuleuven.be, E-mail: wubbenhorst@fys.kuleuven.be; Putzeys, T.; Wübbenhorst, M., E-mail: angeline.kasina@fys.kuleuven.be, E-mail: wubbenhorst@fys.kuleuven.be [Department of Physics and Astronomy, Soft Matter and Biophysics Section, KU Leuven, Leuven (Belgium)

    2015-12-28

    Recently [S. Capponi, S. Napolitano, and M. Wübbenhorst, Nat. Commun. 3, 1233 (2012)], vapor deposited glasses of glycerol have been found to recover their super-cooled liquid state via a metastable, ordered liquid (MROL) state characterized by a tremendously enhanced dielectric strength along with a slow-down of the relaxation rate of the structural relaxation. To study the calorimetric signature of this phenomenon, we have implemented a chip-based, differential AC calorimeter in an organic molecular beam deposition setup, which allows the simultaneous measurement of dielectric relaxations via interdigitated comb electrodes and specific heat relaxation spectra during deposition and as function of the temperature. Heating of the as-deposited glass just above the bulk T{sub g} and subsequent cooling/reheating revealed a step-wise increase in c{sub p} by in total 9%, indicating unambiguously that glycerol, through slow vapour deposition, forms a thermodynamically stable glass, which has a specific heat as low as that of crystalline glycerol. Moreover, these glasses were found to show excellent kinetic stability as well as evidenced by both a high onset-temperature and quasi-isothermal recovery measurements at −75 °C. The second goal of the study was to elucidate the impact of the MROL state on the specific heat and its relaxation to the super-cooled state. Conversion of “MROL glycerol” to its “normal” (ordinary liquid, OL) state revealed a second, small (∼2%) increase of the glassy c{sub p}, a little gain (<10%) in the relaxed specific heat, and no signs of deviations of τ{sub cal} from that of normal “bulk” glycerol. These findings altogether suggest that the MROL state in glycerol comprises largely bulk-type glycerol that coexist with a minor volume fraction (<10%) of PVD-induced structural anomalies with a crystal-like calorimetric signature. Based on the new calorimetric findings, we have proposed a new physical picture that assumes the

  2. Electron beam irradiation of maltodextrin and cinnamyl alcohol mixtures: influence of glycerol on cross-linking.

    Science.gov (United States)

    Khandal, Dhriti; Aggarwal, Manjeet; Suri, Gunjan; Coqueret, Xavier

    2015-03-06

    The influence of glycerol on the electron beam-induced changes in maltodextrins-cinnamyl alcohol (CA) blends is examined with respect to its influence on the degree of chain scission, grafting, and cross-linking. The study is relevant to radiation-induced polysaccharide modification, specifically in the perspective of using blended starch as a thermoplastic material, where glycerol is commonly used as a plasticizer. In the absence of CA, glycerol protects maltodextrin from chromophore formation onto the main chain, but also induces more chain scission. The presence of CA provides efficient radiation-protection against scission. Glycerol is shown to affect the interaction between maltodextrin and CA, most likely in the form of an inclusion complex when glycerol is absent. The global behavior under radiation is therefore governed by the physical interactions between the blend constituents rather than on the role of glycerol role as a plasticizer, or as an OH˙ radical scavenger.

  3. Human skeletal muscle fatty acid and glycerol metabolism during rest, exercise and recovery

    DEFF Research Database (Denmark)

    Van Hall, Gerrit; Sacchetti, M; Rådegran, G

    2002-01-01

    This study was conducted to investigate skeletal muscle fatty acid (FA) and glycerol kinetics and to determine the contribution of skeletal muscle to whole body FA and glycerol turnover during rest, 2 h of one-leg knee-extensor exercise at 65 % of maximal leg power output, and 3 h of recovery....... To this aim, the leg femoral arterial-venous difference technique was used in combination with a continuous infusion of [U-(13)C]palmitate and [(2)H(5)]glycerol in five post-absorptive healthy volunteers (22 +/- 3 years). The influence of contamination from non-skeletal muscle tissues, skin and subcutaneous...... glycerol uptake was observed, which was substantially higher during exercise. Total body skeletal muscle FA and glycerol uptake/release was estimated to account for 18-25 % of whole body R(d) or R(a). In conclusion: (1) skeletal muscle FA and glycerol metabolism, using the leg arterial-venous difference...

  4. Bioconversion of glycerol for bioethanol production using isolated Escherichia coli SS1

    Directory of Open Access Journals (Sweden)

    Sheril Norliana Suhaimi

    2012-06-01

    Full Text Available Bioconverting glycerol into various valuable products is one of glycerol's promising applications due to its high availability at low cost and the existence of many glycerol-utilizing microorganisms. Bioethanol and biohydrogen, which are types of renewable fuels, are two examples of bioconverted products. The objectives of this study were to evaluate ethanol production from different media by local microorganism isolates and compare the ethanol fermentation profile of the selected strains to use of glucose or glycerol as sole carbon sources. The ethanol fermentations by six isolates were evaluated after a preliminary screening process. Strain named SS1 produced the highest ethanol yield of 1.0 mol: 1.0 mol glycerol and was identified as Escherichia coli SS1 Also, this isolated strain showed a higher affinity to glycerol than glucose for bioethanol production.

  5. Engineering an Obligate Photoautotrophic Cyanobacterium to Utilize Glycerol for Growth and Chemical Production.

    Science.gov (United States)

    Kanno, Masahiro; Atsumi, Shota

    2017-01-20

    Cyanobacteria have attracted much attention as a means to directly recycle carbon dioxide into valuable chemicals that are currently produced from petroleum. However, the titers and productivities achieved are still far below the level required in industry. To make a more industrially applicable production scheme, glycerol, a byproduct of biodiesel production, can be used as an additional carbon source for photomixotrophic chemical production. Glycerol is an ideal candidate due to its availability and low cost. In this study, we found that a heterologous glycerol respiratory pathway enabled Synechococcus elongatus PCC 7942 to utilize extracellular glycerol. The engineered strain produced 761 mg/L of 2,3-butanediol in 48 h with a 290% increase over the control strain under continuous light conditions. Glycerol supplementation also allowed for continuous cell growth and 2,3-butanediol production in diurnal light conditions. These results highlight the potential of glycerol as an additional carbon source for photomixotrophic chemical production in cyanobacteria.

  6. Enhancing Effect of Glycerol on the Tensile Properties of Bombyx mori Cocoon Sericin Films

    OpenAIRE

    Liangjun Zhu; Lei Yang; Sijia Min; Haiping Zhang; Lianxia Deng; Mingying Yang

    2011-01-01

    An environmental physical method described herein was developed to improve the tensile properties of Bombyx mori cocoon sericin films, by using the plasticizer of glycerol, which has a nontoxic effect compared with other chemical crosslinkers. The changes in the tensile characteristics and the structure of glycerolated (0–40 wt% of glycerol) sericin films were investigated. Sericin films, both in dry and wet states, showed enhanced tensile properties, which might be regulated by the addition ...

  7. Quantitative analysis of glycerol in dicarboxylic acid-rich cutins provides insights into Arabidopsis cutin structure.

    Science.gov (United States)

    Yang, Weili; Pollard, Mike; Li-Beisson, Yonghua; Ohlrogge, John

    2016-10-01

    Cutin is an extracellular lipid polymer that contributes to protective cuticle barrier functions against biotic and abiotic stresses in land plants. Glycerol has been reported as a component of cutin, contributing up to 14% by weight of total released monomers. Previous studies using partial hydrolysis of cuticle-enriched preparations established the presence of oligomers with glycerol-aliphatic ester links. Furthermore, glycerol-3-phosphate 2-O-acyltransferases (sn-2-GPATs) are essential for cutin biosynthesis. However, precise roles of glycerol in cutin assembly and structure remain uncertain. Here, a stable isotope-dilution assay was developed for the quantitative analysis of glycerol by GC/MS of triacetin with simultaneous determination of aliphatic monomers. To provide clues about the role of glycerol in dicarboxylic acid (DCA)-rich cutins, this methodology was applied to compare wild-type (WT) Arabidopsis cutin with a series of mutants that are defective in cutin synthesis. The molar ratio of glycerol to total DCAs in WT cutins was 2:1. Even when allowing for a small additional contribution from hydroxy fatty acids, this is a substantially higher glycerol to aliphatic monomer ratio than previously reported for any cutin. Glycerol content was strongly reduced in both stem and leaf cutin from all Arabidopsis mutants analyzed (gpat4/gpat8, att1-2 and lacs2-3). In addition, the molar reduction of glycerol was proportional to the molar reduction of total DCAs. These results suggest "glycerol-DCA-glycerol" may be the dominant motif in DCA-rich cutins. The ramifications and caveats for this hypothesis are presented.

  8. Effects of sorbitol and glycerol on the structure, dynamics, and stability of Mycobacterium tuberculosis pyrazinamidase

    Directory of Open Access Journals (Sweden)

    Mehrnoosh Khajehzadeh

    2016-01-01

    Conclusion: It can be concluded that the native conformation of the enzyme was stabilized in the sorbitol and glycerol and tend to exclude from the PZase surface, forcing the enzyme to keep it in the compactly folded conformation. The glycerol molecules stabilized PZase by decreasing the loops flexibility and then compacting the enzyme structure. It appears that more stability of PZase in glycerol solution correlates with its amphiphilic orientation, which decreases the unfavorable interactions of hydrophobic regions.

  9. Quantitative analysis of glycerol accumulation, glycolysis and growth under hyper osmotic stress.

    Directory of Open Access Journals (Sweden)

    Elzbieta Petelenz-Kurdziel

    Full Text Available We provide an integrated dynamic view on a eukaryotic osmolyte system, linking signaling with regulation of gene expression, metabolic control and growth. Adaptation to osmotic changes enables cells to adjust cellular activity and turgor pressure to an altered environment. The yeast Saccharomyces cerevisiae adapts to hyperosmotic stress by activating the HOG signaling cascade, which controls glycerol accumulation. The Hog1 kinase stimulates transcription of genes encoding enzymes required for glycerol production (Gpd1, Gpp2 and glycerol import (Stl1 and activates a regulatory enzyme in glycolysis (Pfk26/27. In addition, glycerol outflow is prevented by closure of the Fps1 glycerol facilitator. In order to better understand the contributions to glycerol accumulation of these different mechanisms and how redox and energy metabolism as well as biomass production are maintained under such conditions we collected an extensive dataset. Over a period of 180 min after hyperosmotic shock we monitored in wild type and different mutant cells the concentrations of key metabolites and proteins relevant for osmoadaptation. The dataset was used to parameterize an ODE model that reproduces the generated data very well. A detailed computational analysis using time-dependent response coefficients showed that Pfk26/27 contributes to rerouting glycolytic flux towards lower glycolysis. The transient growth arrest following hyperosmotic shock further adds to redirecting almost all glycolytic flux from biomass towards glycerol production. Osmoadaptation is robust to loss of individual adaptation pathways because of the existence and upregulation of alternative routes of glycerol accumulation. For instance, the Stl1 glycerol importer contributes to glycerol accumulation in a mutant with diminished glycerol production capacity. In addition, our observations suggest a role for trehalose accumulation in osmoadaptation and that Hog1 probably directly contributes to the

  10. Duct Leakage Repeatability Testing

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Iain [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sherman, Max [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2014-01-01

    Duct leakage often needs to be measured to demonstrate compliance with requirements or to determine energy or Indoor Air Quality (IAQ) impacts. Testing is often done using standards such as ASTM E1554 (ASTM 2013) or California Title 24 (California Energy Commission 2013 & 2013b), but there are several choices of methods available within the accepted standards. Determining which method to use or not use requires an evaluation of those methods in the context of the particular needs. Three factors that are important considerations are the cost of the measurement, the accuracy of the measurement and the repeatability of the measurement. The purpose of this report is to evaluate the repeatability of the three most significant measurement techniques using data from the literature and recently obtained field data. We will also briefly discuss the first two factors. The main question to be answered by this study is to determine if differences in the repeatability of these tests methods is sufficient to indicate that any of these methods is so poor that it should be excluded from consideration as an allowed procedure in codes and standards.

  11. Effects of deletion of glycerol-3-phosphate dehydrogenase and glutamate dehydrogenase genes on glycerol and ethanol metabolism in recombinant Saccharomyces cerevisiae.

    Science.gov (United States)

    Kim, Jin-Woo; Chin, Young-Wook; Park, Yong-Cheol; Seo, Jin-Ho

    2012-01-01

    Bioethanol is currently used as an alternative fuel for gasoline worldwide. For economic production of bioethanol by Saccharomyces cerevisiae, formation of a main by-product, glycerol, should be prevented or minimized in order to reduce a separation cost of ethanol from fermentation broth. In this study, S. cerevisiae was engineered to investigate the effects of the sole and double disruption of NADH-dependent glycerol-3-phosphate dehydrogenase 1 (GPD1) and NADPH-requiring glutamate dehydrogenase 1 (GDH1) on the production of glycerol and ethanol from glucose. Even though sole deletion of GPD1 or GDH1 reduced glycerol production, double deletion of GPD1 and GDH1 resulted in the lowest glycerol concentration of 2.31 g/L, which was 46.4% lower than the wild-type strain. Interestingly, the recombinant S. cerevisiae ∆GPD1∆GDH1 strain showed a slight improvement in ethanol yield (0.414 g/g) compared with the wild-type strain (0.406 g/g). Genetic engineering of the glycerol and glutamate metabolic pathways modified NAD(P)H-requiring metabolic pathways and exerted a positive effect on glycerol reduction without affecting ethanol production.

  12. Microbial synthesis of polyhydroxybutyrate from glycerol: gluconeogenesis, molecular weight and material properties of biopolyester.

    Science.gov (United States)

    Tanadchangsaeng, Nuttapol; Yu, Jian

    2012-11-01

    Glycerol is considered as an ideal feedstock for producing bioplastics via bacterial fermentation due to its ubiquity, low price, and high degree of reduction substrate. In this work, we study the yield and cause of limitation in poly(3-hydroxybutyrate) (PHB) production from glycerol. Compared to glucose-based PHB production, PHB produced by Cupriavidus necator grown on glycerol has a low productivity (0.92 g PHB/L/h) with a comparably low maximum specific growth rate of 0.11 h(-1) . We found that C. necator can synthesize glucose from glycerol and that the lithotrophical utilization of glycerol (non-fermentative substrate) or gluconeogenesis is an essential metabolic pathway for biosynthesis of cellular components. Here, we show that gluconeogenesis affects the reduction of cell mass, the productivity of biopolymer product, and the molecular chain size of intracellular PHB synthesized from glycerol by C. necator. We use NMR spectroscopy to show that the isolated PHB is capped by glycerol. We then characterized the physical properties of the isolated glycerol-based PHB with differential scanning calorimetry and tensile tests. We found that although the final molecular weight of the glycerol-based PHB is lower than those of glucose-based and commercial PHB, the thermal and mechanical properties of the biopolymers are similar.

  13. Engineering of the glycerol decomposition pathway and cofactor regulation in an industrial yeast improves ethanol production.

    Science.gov (United States)

    Zhang, Liang; Tang, Yan; Guo, Zhongpeng; Shi, Guiyang

    2013-10-01

    Glycerol is a major by-product of industrial ethanol production and its formation consumes up to 4 % of the sugar substrate. This study modified the glycerol decomposition pathway of an industrial strain of Saccharomyces cerevisiae to optimize the consumption of substrate and yield of ethanol. This study is the first to couple glycerol degradation with ethanol formation, to the best of our knowledge. The recombinant strain overexpressing GCY1 and DAK1, encoding glycerol dehydrogenase and dihydroxyacetone kinase, respectively, in glycerol degradation pathway, exhibited a moderate increase in ethanol yield (2.9 %) and decrease in glycerol yield (24.9 %) compared to the wild type with the initial glucose concentration of 15 % under anaerobic conditions. However, when the mhpF gene, encoding acetylating NAD⁺-dependent acetaldehyde dehydrogenase from Escherichia coli, was co-expressed in the aforementioned recombinant strain, a further increase in ethanol yield by 5.5 % and decrease in glycerol yield by 48 % were observed for the resultant recombinant strain GDMS1 when acetic acid was added into the medium prior to inoculation compared to the wild type. The process outlined in this study which enhances glycerol consumption and cofactor regulation in an industrial yeast is a promising metabolic engineering strategy to increase ethanol production by reducing the formation of glycerol.

  14. Dietary Tools To Modulate Glycogen Storage in Gilthead Seabream Muscle: Glycerol Supplementation

    DEFF Research Database (Denmark)

    Silva, Tomé S.; Matos, Elisabete; Cordeiro, Odete D.

    2012-01-01

    The quality and shelf life of fish meat products depend on the skeletal muscle’s energetic state at slaughter, as meat decomposition processes can be exacerbated by energy depletion. In this study, we tested dietary glycerol as a way of replenishing muscle glycogen reserves of farmed gilthead......, and organoleptic properties (aroma and color). Proteomic analysis showed a low impact of glycerol-supplementation on muscle metabolism, with most changes probably reflecting increased stress coping capacity in glycerol-fed fish. This suggests inclusion of crude glycerol in gilthead seabream diets (particularly...

  15. Dynamics of pure tone audiometry and DPOAE changes induced by glycerol in Meniere's disease.

    Science.gov (United States)

    Jablonka-Strom, Agnieszka; Pospiech, Lucyna; Zatonski, Maciej; Bochnia, Marek

    2013-05-01

    The purpose of this study is to follow up the dynamics of pure tone threshold and DPOAE amplitude changes induced by glycerol with reference to its activity in the inner ear. Selection was made among 38 patients with Meniere's disease for those having positive glycerol test. Pure-tone audiometry and DP-gram were performed in four series: as an initial examination before glycerol intake, 1, 2 and 3 h after. Audiometric changes formed distinct biphasal pattern at all frequencies between 250 and 4,000 Hz. The most dynamic pure tone threshold decrease occurred during the first hour. Between the first and second hour after glycerol ingestion there was a phase of no significant hearing changes. Further pure tone threshold decrease went on within the third hour reaching its top. Observing DPOAE changes, the highest DP amplitude growth occurred after the second and the third hour at DP-gram frequencies 2, 3 and 4 kHz. The fastest DP-amplitude increase was registered as well during the first hour after glycerol ingestion. In 11 persons with both audiometry and DPOAE positive glycerol test, parallel dynamics in the course of the glycerol test was observed. Biphasal glycerol test dynamics suggests the possibility of two mechanisms of glycerol activity in the inner ear.

  16. Photocatalytic hydrogen generation using glycerol wastewater over Pt/TiO2

    Institute of Scientific and Technical Information of China (English)

    Min LI; Yuexiang LI; Shaoqin PENG; Gongxuan LU; Shuben LI

    2009-01-01

    Using glycerol as electron donor, photocataly-tic hydrogen generation over Pt/TiO2 was investigated.The results show that glycerol can not only improve the efficiency of photocatalytic hydrogen generation but can also be decomposed effectively. The factors which affect photocatalytic hydrogen generation, such as irradiation time, initial concentration of the glycerol solution, pH-value of the suspensions and the coexisting substances were studied. The final oxidation products of glycerol were H2O and CO2. Glyceraldhyde, glycoladehyde, glycolic acid and formaldehyde were identified as the intermedi-ates. A possible reaction mechanism was discussed.

  17. In situ visualization and effect of glycerol in lipase-catalyzed ethanolysis of rapeseed oil

    DEFF Research Database (Denmark)

    Xu, Yuan; Nordblad, Mathias; Nielsen, Per M.;

    2011-01-01

    Immobilized lipases can be used in biodiesel production to overcome many disadvantages of the conventional base-catalyzed process. However, the glycerol by-product poses a potential problem for the biocatalytic process as it is known to inhibit immobilized lipases, most likely by clogging...... to illustrate the interaction of glycerol with immobilized lipases and thus provided an aid for screening supports for lipase immobilization according to their interaction with glycerol. Glycerol was found to have great affinity for silica, less for polystyrene and no affinity for supports made from...

  18. Effect of crude glycerol-derived inhibitors on ethanol production by Enterobacter aerogenes.

    Science.gov (United States)

    Lee, Sang Jun; Kim, Sung Bong; Kang, Seong Woo; Han, Sung Ok; Park, Chulhwan; Kim, Seung Wook

    2012-01-01

    In this study, ethanol production from pure and crude glycerol using Enterobacter aerogenes ATCC 29007 was evaluated under anaerobic culture conditions. Inhibitory effects of substrate concentrations, pH, and salt concentrations were investigated based on crude glycerol components. Ethanol production was performed with pure glycerol concentrations ranging from 5 to 30 g/L to evaluate the effects of substrate concentration and osmotic pressure. The consumed glycerol was 5-14.33 g/L, and the yield of ethanol was higher than 0.75 mol ethanol/mol glycerol after 24 h of cultivation. To evaluate the inhibitory effects of salts (NaCl and KCl), experiments were performed with 0-20 g/L of each salt. Inhibitory effects of salts were strongest at high salt concentrations. The inhibitory effect of pH was performed in the pH range 4-10, and cell growth and ethanol production were highest at pH 5-6. Also, ethanol production was slightly inhibited at low concentration of crude glycerol comparison with pure glycerol. However, significant inhibitory effects were not observed at 1.5 and 2% crude glycerol which showed higher ethanol production compared to pure glycerol.

  19. Glycerol-Preserved Arterial Allografts Evaluated in the Infrarenal Rat Aorta

    National Research Council Canada - National Science Library

    Fahner, P.J; Idu, M.M; van Gulik, T.M; van Wijk, B; van der Wal, A.C; Legemate, D.A

    2009-01-01

    .... Since glycerol preservation proved effective for the storage of skin allografts, this preservation method was investigated for vascular allografts using a rat aortic transplantation model. Methods...

  20. Scattering of water from the glycerol liquid-vacuum interface

    Science.gov (United States)

    Benjamin, I.; Wilson, M. A.; Pohorille, A.; Nathanson, G. M.

    1995-01-01

    Molecular dynamics calculations of the scattering of D2O from the glycerol surface at different collision energies are reported. The results for the trapping probabilities and energy transfer are in good agreement with experiments. The calculations demonstrate that the strong attractive forces between these two strongly hydrogen bonding molecules have only a minor effect on the initial collision dynamics. The trapping probability is influenced to a significant extent by the repulsive hard sphere-like initial encounter with the corrugated surface and, only at a later stage, by the efficiency of energy flow in the multiple interactions between the water and the surface molecules.

  1. Comparison of Different Strategies for Selection/Adaptation of Mixed Microbial Cultures Able to Ferment Crude Glycerol Derived from Second-Generation Biodiesel

    Directory of Open Access Journals (Sweden)

    C. Varrone

    2015-01-01

    Full Text Available Objective of this study was the selection and adaptation of mixed microbial cultures (MMCs, able to ferment crude glycerol generated from animal fat-based biodiesel and produce building-blocks and green chemicals. Various adaptation strategies have been investigated for the enrichment of suitable and stable MMC, trying to overcome inhibition problems and enhance substrate degradation efficiency, as well as generation of soluble fermentation products. Repeated transfers in small batches and fed-batch conditions have been applied, comparing the use of different inoculum, growth media, and Kinetic Control. The adaptation of activated sludge inoculum was performed successfully and continued unhindered for several months. The best results showed a substrate degradation efficiency of almost 100% (about 10 g/L glycerol in 21 h and different dominant metabolic products were obtained, depending on the selection strategy (mainly 1,3-propanediol, ethanol, or butyrate. On the other hand, anaerobic sludge exhibited inactivation after a few transfers. To circumvent this problem, fed-batch mode was used as an alternative adaptation strategy, which led to effective substrate degradation and high 1,3-propanediol and butyrate production. Changes in microbial composition were monitored by means of Next Generation Sequencing, revealing a dominance of glycerol consuming species, such as Clostridium, Klebsiella, and Escherichia.

  2. Comparison of Different Strategies for Selection/Adaptation of Mixed Microbial Cultures Able to Ferment Crude Glycerol Derived from Second-Generation Biodiesel

    Science.gov (United States)

    Varrone, C.; Heggeset, T. M. B.; Le, S. B.; Haugen, T.; Markussen, S.; Skiadas, I. V.; Gavala, H. N.

    2015-01-01

    Objective of this study was the selection and adaptation of mixed microbial cultures (MMCs), able to ferment crude glycerol generated from animal fat-based biodiesel and produce building-blocks and green chemicals. Various adaptation strategies have been investigated for the enrichment of suitable and stable MMC, trying to overcome inhibition problems and enhance substrate degradation efficiency, as well as generation of soluble fermentation products. Repeated transfers in small batches and fed-batch conditions have been applied, comparing the use of different inoculum, growth media, and Kinetic Control. The adaptation of activated sludge inoculum was performed successfully and continued unhindered for several months. The best results showed a substrate degradation efficiency of almost 100% (about 10 g/L glycerol in 21 h) and different dominant metabolic products were obtained, depending on the selection strategy (mainly 1,3-propanediol, ethanol, or butyrate). On the other hand, anaerobic sludge exhibited inactivation after a few transfers. To circumvent this problem, fed-batch mode was used as an alternative adaptation strategy, which led to effective substrate degradation and high 1,3-propanediol and butyrate production. Changes in microbial composition were monitored by means of Next Generation Sequencing, revealing a dominance of glycerol consuming species, such as Clostridium, Klebsiella, and Escherichia. PMID:26509171

  3. Repeatability of Cryogenic Multilayer Insulation

    Science.gov (United States)

    Johnson, W. L.; Vanderlaan, M.; Wood, J. J.; Rhys, N. O.; Guo, W.; Van Sciver, S.; Chato, D. J.

    2017-01-01

    Due to the variety of requirements across aerospace platforms, and one off projects, the repeatability of cryogenic multilayer insulation has never been fully established. The objective of this test program is to provide a more basic understanding of the thermal performance repeatability of MLI systems that are applicable to large scale tanks. There are several different types of repeatability that can be accounted for: these include repeatability between multiple identical blankets, repeatability of installation of the same blanket, and repeatability of a test apparatus. The focus of the work in this report is on the first two types of repeatability. Statistically, repeatability can mean many different things. In simplest form, it refers to the range of performance that a population exhibits and the average of the population. However, as more and more identical components are made (i.e. the population of concern grows), the simple range morphs into a standard deviation from an average performance. Initial repeatability testing on MLI blankets has been completed at Florida State University. Repeatability of five GRC provided coupons with 25 layers was shown to be +/- 8.4 whereas repeatability of repeatedly installing a single coupon was shown to be +/- 8.0. A second group of 10 coupons have been fabricated by Yetispace and tested by Florida State University, through the first 4 tests, the repeatability has been shown to be +/- 16. Based on detailed statistical analysis, the data has been shown to be statistically significant.

  4. Sustaining Biodiesel Production via Value-Added Applications of Glycerol

    Directory of Open Access Journals (Sweden)

    Omotola Babajide

    2013-01-01

    Full Text Available The production of biofuels worldwide has been significant lately due to the shift from obtaining energy from nonrenewable energy (fossil fuels to renewable sources (biofuels. This energy shift arose as a result of the disturbing crude petroleum price fluctuations, uncertainties about fossil fuel reserves, and greenhouse gas (GHG concerns. With the production of biofuels increasing considerably and the current global biodiesel production from different feedstock, reaching about 6 billion liters per year, biodiesel production costs have been highly dependent on feedstock prices, ranging from 70 to 25; of total production costs, and in comparison with the conventional diesel fuel, the biodiesel is currently noncompetitive. An efficient production process is, therefore, crucial to lowering biodiesel production costs. The question of sustainability, however, arises, taking into account the African diverse conditions and how vital concerns need to be addressed. The major concern about biodiesel production costs can be reduced by finding value-added applications for its glycerol byproduct. This paper, thus, provides an overview of current research trends that could overcome the major hurdles towards profitable commercialization of biodiesel and also proposes areas of opportunity probable to capitalize the surplus glycerol obtained, for numerous applications.

  5. Polyhydroxyalkanoate production from crude glycerol by newly isolated Pandoraea sp.

    Directory of Open Access Journals (Sweden)

    Fabrício Coutinho de Paula

    2017-04-01

    Full Text Available A new bacterial strain was isolated from Atlantic rainforest in Brazil for polyhydroxyalkanoate (PHA production utilizing crude glycerol from biodiesel industry (CG and it was identified as Pandoraea sp. MA03. Shake flask experiments were performed at 10–50 g L−1 carbon source and showed the best values of poly(3-hydroxybutyrate (P3HB production from CG cultivations compared to pure glycerol, with a polymer accumulation ranging from 49.0% to 63.6% cell dry weight (CDW. The results obtained from this study showed a positive effect of contaminant NaCl on P3HB synthesis up to 30 g L−1 CG. Poly(3-hydroxybutyrate-co-3-hydroxyvalerate [P(3HB-co-3HV] production was obtained from CG plus propionic acid with up to 25.9 mol% 3HV. Since it is interesting the utilization of CG for obtaining added-value products along with biodiesel, this study reported a novel and promising PHA-producing bacterial strain as an additional effort to enhance the viability of a sustainable industry based on biofuels and biopolymers.

  6. Green tea catechins: inhibitors of glycerol-3-phosphate dehydrogenase.

    Science.gov (United States)

    Kao, Chung-Cheng; Wu, Bo-Tsung; Tsuei, Yi-Wei; Shih, Li-Jane; Kuo, Yu-Liang; Kao, Yung-Hsi

    2010-05-01

    Green tea catechins, especially (-)-epigallocatechin-3-gallate (EGCG), are known to regulate obesity and fat accumulation. We performed a kinetic analysis in a cell-free system to determine the mode of inhibition of glycerol-3-phosphate dehydrogenase (GPDH; EC 1.1.1.8) by EGCG. GPDH catalyzes the beta-nicotinamide adenine dinucleotide (NADH)-dependent reduction of dihydroxyacetone phosphate (DHAP) to yield glycerol-3-phosphate, which serves as one of the major precursors of triacylglycerols. We found that EGCG dose-dependently inhibited GPDH activity at a concentration of approximately 20 muM for 50 % inhibition. The IC (50) values of other green tea catechins, such as (-)-epicatechin, (-)-epicatechin-3-gallate, and (-)-epigallocatechin, were all above 100 microM. This suggests a catechin type-dependent effect. Based on double-reciprocal plots of the kinetic data, EGCG was a noncompetitive inhibitor of the GPDH substrates, NADH and DHAP, with respective inhibition constants (Ki) of 18 and 31 microM. Results of this study possibly support previous studies that EGCG mediates fat content. Georg Thieme Verlag KG Stuttgart. New York.

  7. Stability conditions and mechanism of cream soaps: role of glycerol.

    Science.gov (United States)

    Sagitani, Hiromichi

    2014-01-01

    Fatty acids, fatty acid potassium soaps, glycerol and water are essential ingredients in the production of stable cream soaps. In this study, the behavior of these components in solution was investigated to elucidate the stability conditions and mechanism of cream soaps. It was determined that the cream soaps were a dispersion of 1:1 acid soap (1:1 molar ratio of potassium soap/fatty acid) crystals in the lamellar gel phase, which has confirmed from the phase behavior diagrams and small angle X-ray scattering data. Glycerol was crucial ingredient in the formation of the lamellar gel phase. The cleansing process of the cream soaps was also evaluated using the same diagrams. The structure of the continuous phase in cream soaps changed from lamellar gel to a micellar aqueous solution upon the addition of water. This structural change during the washing process is important in producing the foaming activity of acid soaps to wash away dirt or excess fats from the skin surface.

  8. Hydrogen production by sorption-enhanced steam reforming of glycerol.

    Science.gov (United States)

    Dou, Binlin; Dupont, Valerie; Rickett, Gavin; Blakeman, Neil; Williams, Paul T; Chen, Haisheng; Ding, Yulong; Ghadiri, Mojtaba

    2009-07-01

    Catalytic steam reforming of glycerol for H(2) production has been evaluated experimentally in a continuous flow fixed-bed reactor. The experiments were carried out under atmospheric pressure within a temperature range of 400-700 degrees C. A commercial Ni-based catalyst and a dolomite sorbent were used for the steam reforming reactions and in situ CO(2) removal. The product gases were measured by on-line gas analysers. The results show that H(2) productivity is greatly increased with increasing temperature and the formation of methane by-product becomes negligible above 500 degrees C. The results suggest an optimal temperature of approximately 500 degrees C for the glycerol steam reforming with in situ CO(2) removal using calcined dolomite as the sorbent, at which the CO(2) breakthrough time is longest and the H(2) purity is highest. The shrinking core model and the 1D-diffusion model describe well the CO(2) removal under the conditions of this work.

  9. Glycerol Production and Transformation: A Critical Review with Particular Emphasis on Glycerol Reforming Reaction for Producing Hydrogen in Conventional and Membrane Reactors

    Science.gov (United States)

    Bagnato, Giuseppe; Iulianelli, Adolfo; Sanna, Aimaro; Basile, Angelo

    2017-01-01

    Glycerol represents an emerging renewable bio-derived feedstock, which could be used as a source for producing hydrogen through steam reforming reaction. In this review, the state-of-the-art about glycerol production processes is reviewed, with particular focus on glycerol reforming reactions and on the main catalysts under development. Furthermore, the use of membrane catalytic reactors instead of conventional reactors for steam reforming is discussed. Finally, the review describes the utilization of the Pd-based membrane reactor technology, pointing out the ability of these alternative fuel processors to simultaneously extract high purity hydrogen and enhance the whole performances of the reaction system in terms of glycerol conversion and hydrogen yield. PMID:28333121

  10. Glycerol Production and Transformation: A Critical Review with Particular Emphasis on Glycerol Reforming Reaction for Producing Hydrogen in Conventional and Membrane Reactors.

    Science.gov (United States)

    Bagnato, Giuseppe; Iulianelli, Adolfo; Sanna, Aimaro; Basile, Angelo

    2017-03-23

    Glycerol represents an emerging renewable bio-derived feedstock, which could be used as a source for producing hydrogen through steam reforming reaction. In this review, the state-of-the-art about glycerol production processes is reviewed, with particular focus on glycerol reforming reactions and on the main catalysts under development. Furthermore, the use of membrane catalytic reactors instead of conventional reactors for steam reforming is discussed. Finally, the review describes the utilization of the Pd-based membrane reactor technology, pointing out the ability of these alternative fuel processors to simultaneously extract high purity hydrogen and enhance the whole performances of the reaction system in terms of glycerol conversion and hydrogen yield.

  11. Enhancing effect of glycerol on the tensile properties of Bombyx mori cocoon sericin films.

    Science.gov (United States)

    Zhang, Haiping; Deng, Lianxia; Yang, Mingying; Min, Sijia; Yang, Lei; Zhu, Liangjun

    2011-01-01

    An environmental physical method described herein was developed to improve the tensile properties of Bombyx mori cocoon sericin films, by using the plasticizer of glycerol, which has a nontoxic effect compared with other chemical crosslinkers. The changes in the tensile characteristics and the structure of glycerolated (0-40 wt% of glycerol) sericin films were investigated. Sericin films, both in dry and wet states, showed enhanced tensile properties, which might be regulated by the addition of different concentrations of glycerol. The introduction of glycerol results in the higher amorphous structure in sericin films as evidenced by analysis of attenuated total reflection Fourier transform infrared (ATR-FTIR) spectra, thermogravimetry (TGA) and differential scanning calorimetry (DSC) curves. Scanning Electron Microscopy (SEM) observation revealed that glycerol was homogeneously blended with sericin molecules when its content was 10 wt%, while a small amount of redundant glycerol emerged on the surface of sericin films when its content was increased to 20 wt% or higher. Our results suggest that the introduction of glycerol is a novel nontoxic strategy which can improve the mechanical features of sericin-based materials and subsequently promote the feasibility of its application in tissue engineering.

  12. Effects of glycerol on the molecular mobility and hydrogen bond network in starch matrix.

    Science.gov (United States)

    Liang, Jun; Ludescher, Richard D

    2015-01-22

    The effects of glycerol on molecular mobility and hydrogen bonding network in an amorphous glassy starch matrix were studied using phosphorescence and IR spectroscopy. Amorphous potato starch films containing varying amounts of glycerol (0, 5, 10, 20 and 30 wt.%) were formulated by rapidly dehydrating aqueous potato starch gel (5%, w/v) with a corresponding content of glycerol; X-ray diffraction data confirm that the films contained negligible content of crystalline starch. Erythrosin B (Ery B) phosphorescence was used to monitor the molecular mobility of these matrices over the temperature range from 0 to 100°C. Analysis of Ery B emission peak frequency, band width and intensity decay provided information about thermally-activated modes of molecular mobility in the matrix. Dipolar relaxation around the triplet state of Ery B was enhanced by addition of glycerol and the extent of relaxation increased at low and intermediate but decreased at higher temperature. The glycerol content-dependent onset temperature for this transition was 70°C for pure starch and decreased to 40°C for a matrix with 30% glycerol. Measurements of the rate of non-radiative decay from the Ery B triplet state indicated that glycerol plasticized the starch matrix above ∼10 wt.% while acting as an antiplastizer to increase the matrix molecular mobility at lower content. These matrix properties were related to glycerol-dependent increases in hydrogen bond strength as measured by IR.

  13. Bench scale demonstration of the Supermethanol concept : The synthesis of methanol from glycerol derived syngas

    NARCIS (Netherlands)

    van Bennekom, J. G.; Venderbosch, R. H.; Assink, D.; Lemmens, K. P. J.; Heeres, H. J.

    2012-01-01

    An integrated process for the synthesis of methanol from aqueous glycerol involving reforming of the feed to syngas followed by methanol synthesis is successfully demonstrated in a continuous bench scale unit. Glycerol reforming was carried out at pressures of 24-27 MPa and temperatures of 948-998 K

  14. Effect of glycerol on the morphology of starch-sunflower oil composites

    NARCIS (Netherlands)

    Yilmaz, G.; Jongboom, R.O.J.; Soest, van J.J.G.; Feil, H.

    1999-01-01

    The presented study involves the encapsulation of sunflower oil in starch by casting emulsions of oil in aqueous starch solutions. Glycerol was used as a plasticizer and lecithin was used as an emulsifier, to improve the emulsion stability. Increasing glycerol concentration in the samples resulted

  15. Model studies on acrylamide generation from glucose/asparagine in aqueous glycerol

    DEFF Research Database (Denmark)

    Hedegaard, Rikke Susanne Vingborg; Frandsen, Henrik Lauritz; Granby, Kit

    2007-01-01

    Acrylamide formation from asparagine and glucose in different ratios in neutral glycerol/water mixtures was found to increase with decreasing water activity (0.33......Acrylamide formation from asparagine and glucose in different ratios in neutral glycerol/water mixtures was found to increase with decreasing water activity (0.33...

  16. The Lewis-acid-catalyzed synthesis of hyperbranched poly(glycerol-diacid)s in toluene

    Science.gov (United States)

    The first examples of monomeric glycerol-derived hyperbranched polyesters produced in a non-polar solvent system are reported here. The polymers were made by the Lewis acid (dibutyltin(IV)oxide)-catalyzed polycondensation of glycerol with either succinic acid (n (aliphatic chain length)=2), glutari...

  17. Techno-economic risk analysis of glycerol biorefinery concepts against market price fluctuation

    DEFF Research Database (Denmark)

    Gargalo, Carina L.; Cheali, Peam; Gernaey, Krist

    , certain algae species also accumulate large amounts of glycerol and could become another possible source due to the recent development of algae biomass as feedstock for biofuel production [10]. In this contribution, we study and critically analyze a number of glycerol biorefinery concepts developed...

  18. Biodegradable Composites Based on Starch/EVOH/Glycerol Blends and Coconut Fibers

    Science.gov (United States)

    Unripe coconut fibers were used as fillers in a biodegradable polymer matrix of starch/Ethylene vinyl alcohol (EVOH)/glycerol. The effects of fiber content on the mechanical, thermal and structural properties were evaluated. The addition of coconut fiber into starch/EVOH/glycerol blends reduced the ...

  19. Effect of glycerol on the morphology of starch-sunflower oil composites

    NARCIS (Netherlands)

    Yilmaz, G.; Jongboom, R.O.J.; Soest, van J.J.G.; Feil, H.

    1999-01-01

    The presented study involves the encapsulation of sunflower oil in starch by casting emulsions of oil in aqueous starch solutions. Glycerol was used as a plasticizer and lecithin was used as an emulsifier, to improve the emulsion stability. Increasing glycerol concentration in the samples resulted i

  20. Continuous production of glycerol by catalytic high pressure hydrogenolysis of sucrose

    NARCIS (Netherlands)

    van Ling, Gerrit; Driessen, Alfons J.; Piet, Arie C.; Vlugter, Jozef C.

    1970-01-01

    Several continuous reactor systems have been discussed for the catalytic high pressure hydrogenolysis of sucrose to glycerol. Theoretically and actually, continuous reactors lead to lower glycerol yields than in a batch process. Two continuous stirred tank reactors in cascade constitute a reasonable

  1. Continuous production of glycerol by catalytic high pressure hydrogenolysis of sucrose

    NARCIS (Netherlands)

    Ling, van Gerrit; Driessen, Alfons J.; Piet, Arie C.; Vlugter, Jozef C.

    1970-01-01

    Several continuous reactor systems have been discussed for the catalytic high pressure hydrogenolysis of sucrose to glycerol. Theoretically and actually, continuous reactors lead to lower glycerol yields than in a batch process. Two continuous stirred tank reactors in cascade constitute a reasonable

  2. Synthesis of biodiesel fuel additives from glycerol using green chemistry and supercritical fluids

    Science.gov (United States)

    For every 3 moles of fatty acid esters produced, 1 mole of glycerol remains, ~11% of the biodiesel volume. One new method of glycerol use could be as a biodiesel fuel additive/extender using eco-friendly heterogeneous catalysts and supercritical fluids (SFs). SFs have advantages such as greater diff...

  3. Enhancing Effect of Glycerol on the Tensile Properties of Bombyx mori Cocoon Sericin Films

    Directory of Open Access Journals (Sweden)

    Liangjun Zhu

    2011-05-01

    Full Text Available An environmental physical method described herein was developed to improve the tensile properties of Bombyx mori cocoon sericin films, by using the plasticizer of glycerol, which has a nontoxic effect compared with other chemical crosslinkers. The changes in the tensile characteristics and the structure of glycerolated (0–40 wt% of glycerol sericin films were investigated. Sericin films, both in dry and wet states, showed enhanced tensile properties, which might be regulated by the addition of different concentrations of glycerol. The introduction of glycerol results in the higher amorphous structure in sericin films as evidenced by analysis of attenuated total reflection Fourier transform infrared (ATR-FTIR spectra, thermogravimetry (TGA and differential scanning calorimetry (DSC curves. Scanning Electron Microscopy (SEM observation revealed that glycerol was homogeneously blended with sericin molecules when its content was 10 wt%, while a small amount of redundant glycerol emerged on the surface of sericin films when its content was increased to 20 wt% or higher. Our results suggest that the introduction of glycerol is a novel nontoxic strategy which can improve the mechanical features of sericin-based materials and subsequently promote the feasibility of its application in tissue engineering.

  4. Chemoselective Oxidation of Bio-Glycerol with Nano-Sized Metal Catalysts

    DEFF Research Database (Denmark)

    Li, Hu; Kotni, Ramakrishna; Zhang, Qiuyun

    2015-01-01

    to selectively oxidize glycerol and yield products with good selectivity is the use of nano-sized metal particles as heterogeneous catalysts. In this short review, recent developments in chemoselective oxidation of glycerol to specific products over nano-sized metal catalysts are described. Attention is drawn...

  5. Preliminary assessment of synthesis gas production via hybrid steam reforming of methane and glycerol

    NARCIS (Netherlands)

    Balegedde Ramachandran, P.; Rossum, van G.; Kersten, S.R.A.; Swaaij, van W.P.M.

    2012-01-01

    In this article, hybrid steam reforming (HSR) of desulphurized methane, together with crude glycerol, in existing commercial steam reformers to produce synthesis gas is proposed. The proposed concept consists of a gasifier to produce vapors, gases, and char from crude glycerol, which is coupled with

  6. Conversion of Glycerol to 3-Hydroxypropanoic Acid by Genetically Engineered Bacillus subtilis

    DEFF Research Database (Denmark)

    Kalantari, Aida; Chen, Tao; Ji, Boyang

    2017-01-01

    of glycerol into 3-HP. Our recombinant B. subtilis strains overexpress the two-step heterologous pathway containing glycerol dehydratase and aldehyde dehydrogenase from K. pneumoniae. Genetic engineering, driven by in silico optimization, and optimization of cultivation conditions resulted in a 3-HP titer...

  7. Effects of a physiological GH pulse on interstitial glycerol in abdominal and femoral adipose tissue

    DEFF Research Database (Denmark)

    Gravhølt, C H; Schmitz, Ole; Simonsen, L

    1999-01-01

    Physiologically, growth hormone (GH) is secreted in pulses with episodic bursts shortly after the onset of sleep and postprandially. Such pulses increase circulating levels of free fatty acid and glycerol. We tested whether small GH pulses have detectable effects on intercellular glycerol...

  8. Sequential spectrofluorimetric determination of free and total glycerol in biodiesel in a multicommuted flow system

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Sidnei G. [Universidade de Sao Paulo, Instituto de Quimica, Sao Paulo (Brazil); Morales-Rubio, Angel; Guardia, Miguel de la [Universidad de Valencia, Department of Analytical Chemistry, Burjassot, Valencia (Spain); Rocha, Fabio R.P. [Universidade de Sao Paulo, Centro de Energia Nuclear na Agricultura, Piracicaba (Brazil)

    2011-07-15

    A new procedure for spectrofluorimetric determination of free and total glycerol in biodiesel samples is presented. It is based on the oxidation of glycerol by periodate, forming formaldehyde, which reacts with acetylacetone, producing the luminescent 3,5-diacetyl-1,4-dihydrolutidine. A flow system with solenoid micro-pumps is proposed for solution handling. Free glycerol was extracted off-line from biodiesel samples with water, and total glycerol was converted to free glycerol by saponification with sodium ethylate under sonication. For free glycerol, a linear response was observed from 5 to 70 mg L{sup -1} with a detection limit of 0.5 mg L{sup -1}, which corresponds to 2 mg kg{sup -1} in biodiesel. The coefficient of variation was 0.9% (20 mg L{sup -1}, n = 10). For total glycerol, samples were diluted on-line, and the linear response range was 25 to 300 mg L{sup -1}. The detection limit was 1.4 mg L{sup -1} (2.8 mg kg{sup -1} in biodiesel) with a coefficient of variation of 1.4% (200 mg L{sup -1}, n = 10). The sampling rate was ca. 35 samples h{sup -1} and the procedure was applied to determination of free and total glycerol in biodiesel samples from soybean, cottonseed, and castor beans. (orig.)

  9. Sequential spectrofluorimetric determination of free and total glycerol in biodiesel in a multicommuted flow system.

    Science.gov (United States)

    Silva, Sidnei G; Morales-Rubio, Angel; de La Guardia, Miguel; Rocha, Fábio R P

    2011-07-01

    A new procedure for spectrofluorimetric determination of free and total glycerol in biodiesel samples is presented. It is based on the oxidation of glycerol by periodate, forming formaldehyde, which reacts with acetylacetone, producing the luminescent 3,5-diacetyl-1,4-dihydrolutidine. A flow system with solenoid micro-pumps is proposed for solution handling. Free glycerol was extracted off-line from biodiesel samples with water, and total glycerol was converted to free glycerol by saponification with sodium ethylate under sonication. For free glycerol, a linear response was observed from 5 to 70 mg L(-1) with a detection limit of 0.5 mg L(-1), which corresponds to 2 mg kg(-1) in biodiesel. The coefficient of variation was 0.9% (20 mg L(-1), n = 10). For total glycerol, samples were diluted on-line, and the linear response range was 25 to 300 mg L(-1). The detection limit was 1.4 mg L(-1) (2.8 mg kg(-1) in biodiesel) with a coefficient of variation of 1.4% (200 mg L(-1), n = 10). The sampling rate was ca. 35 samples h(-1) and the procedure was applied to determination of free and total glycerol in biodiesel samples from soybean, cottonseed, and castor beans.

  10. Preliminary assessment of synthesis gas production via hybrid steam reforming of methane and glycerol

    NARCIS (Netherlands)

    Balegedde Ramachandran, P.; van Rossum, G.; Kersten, Sascha R.A.; van Swaaij, Willibrordus Petrus Maria

    2012-01-01

    In this article, hybrid steam reforming (HSR) of desulphurized methane, together with crude glycerol, in existing commercial steam reformers to produce synthesis gas is proposed. The proposed concept consists of a gasifier to produce vapors, gases, and char from crude glycerol, which is coupled with

  11. Palatability, digestibility, and metabolizable energy of dietary glycerol in adult cats.

    Science.gov (United States)

    Machado, G S; Pezzali, J G; Marx, F R; Kessler, A M; Trevizan, L

    2017-02-01

    Glycerol is a humectant, which reduces water activity when added to the diet. This property seems to offer dietary benefits, specifically in high-moisture diets for cats, where some humectants cannot be used. According to the U.S. Food and Drug Administration, glycerol is generally recognized as sustenance safe (GRAS). It is suggested that cats are able to metabolize glycerol and use it as an energy source without compromising health. Three experiments were conducted to evaluate the following characteristics of glycerol in the diet for cats: 1) a preference test, 2) digestibility, ME, and fecal and urinary characteristics, and 3) postprandial plasma glycemia. Twelve healthy adult female cats were randomly distributed among 4 treatments consisting of a basal diet (4,090 kcal ME/kg DM, 32% CP, 11% fat, 2.3% crude fiber, and 7.0% ash) and 3 diets with varying percentages of glycerol, made by replacing the basal diet with 2.5, 5.0, and 10.0% purified glycerol (99.5%). The inclusion of glycerol proportionally reduced ( Cats did not show a preference for any diet in particular ( > 0.05). The digestibility assays showed that increasing dietary glycerol levels did not affect food intake or the apparent total tract digestibility of macronutrients and energy ( > 0.05). The inclusion of glycerol in the diets did not alter the stool moisture, fecal score, or urine volume. However, glycerol was detected in urine when it was incorporated into the diet at 10%. Glycemia increased up to 900 min following the first meal after the fasting period with no difference between treatments, even when the means were adjusted for food intake. The blood glucose area under the curve also showed no significant difference between treatments ( > 0.05). Cats accepted glycerol under the conditions of the study, and its nutritional value was determined as it has been done for other species. The ME of glycerol for adult cats was estimated to be 3,185 kcal/kg DM. Supplementing the diets of the cats

  12. Rational design of glycerol dehydratase: Swapping the genes encoding the subunits of glycerol dehydratase to improve enzymatic properties

    Institute of Scientific and Technical Information of China (English)

    QI Xianghui; SUN Liang; LUO Zhaofei; WU Jiequn; MENG Xiaolei; TANG Yue; WEI Yutuo; HUANG Ribo

    2006-01-01

    1,3-propanediol (1,3-PD) is an important material for chemical industry, and there has been always much interest in the production of 1,3-PD using all possible routes. The genes encoding glycerol dehydratase (GDHt) from Citrobacter freundii,Klebsiella pneumoniae and metagenome were cloned and expressed in E. coli. All glycerol dehydratases but the one from metagenome could be detected to show enzyme activities. In order to improve the enzymatic properties of GDHts, the genes encoding α and β-γ subunits were cloned, and the enzyme characteristics were evolved by rational design based on their 3D structures which were constructed by homology modeling. Six heteroenzymes were obtained by swapping the α subunit genes of these three different-source-derived GDHts. The pH,thermal stability and Vmax of some heteroenzymes were dramatically improved by 2-5 times compared with the wild one (GDHtKP). The GDHt cloned from metagenome, originally proved to be with no enzyme activity, was converted into active enzyme by swapping its subunits with other different GDHts. In addition, the effect of subtle 3D structural changes on the properties of the enzyme was also observed.

  13. Glycerol Jelly (GJ) mount: a new and simple method for routine stool examination using a modified glycerol jelly reagent.

    Science.gov (United States)

    Abdel-Hamid, M Y

    2001-08-01

    Wet mount is the basic primary technique for stool examination in laboratories, allowing only the use of X10 and X40 objectives which do not sometimes reveal relevant details to make an exact identification of certain protozoa. In a modification of the Glycerol Jelly (GJ) reagent, which is used in permanent preparation of helminths, five concentrations were prepared and tested for fixing the cover glass instantly while maintaining the high translucency of the fecal films. GJ reagent (7 gm gelatine dissolved in 50 ml boiling water added to 10 ml glycerol) gave satisfactory results especially with iodine and alkaline Methylene blue mounts which stained the cytological structures of protozoa while the GJ reagent enabled the examiner to use X100 oil immersion objective immediately and consequently identify protozoa with certainty and make an accurate identification. Identification of Cryptosporidium parvum oocysts by GJ wet mount, inspite of its small size, was the most impressive. GJ fecal films were examined up to 8 weeks of preparation and they were valid and reliable. GJ mount is an easy, fast and cheap technique for examining the fecal direct smear with the oil-immersion lense.

  14. Distribution of Glycerol Diakyl Glycerol Tetraethers in Surface Soil and Crater Lake Sediments from Mount Kenya, East Africa

    Science.gov (United States)

    Omuombo, C.; Huguet, A.; Olago, D.; Williamson, D.

    2013-12-01

    Glycerol diakyl glycerol tetraethers (GDGTs), a palaeoclimate proxy based on the relative abundance of lipids produced by archaea and bacteria, is gaining wide acceptance for the determination of past temperature and pH conditions. This study looks at the spatial distribution and abundance of GDGTs in soil and sediment samples along an altitudinal transect from 3 crater lakes of Mt. Kenya (Lake Nkunga, Sacred Lake and Lake Rutundu) ranging in elevation from 1700m - 3080m above sea level. GDGTs were extracted with solvents and then analysed using high performance liquid chromatography/atmospheric pressure chemical ionization-mass spectrometry (HPLC/APCI-MS). Mean annual air temperature and pH were estimated based on the relative abundance of the different branched GDGTs, i.e. on the MBT (Methylation index of Branched Tetraethers) and CBT (Cyclization ratio of Branched Tetraethers) indices. Substantial amount of GDGTs were detected in both soil and sediment samples. In addition, branched GDGT distribution was observed to vary with altitude. These results highlight the importance of quantifying the branched GDGTs to understand the environmental parameters controlling the distribution of these lipids. The MBT/CBT proxy is a promising tool to infer palaeotemperatures and characterize the climate events of the past millennia in equatorial east Africa.

  15. Using glycerol produced from biodiesel as a plasticiser in extruded biodegradable films

    Directory of Open Access Journals (Sweden)

    Ana Paula Bilck

    2015-08-01

    Full Text Available AbstractThe demand for renewably sourced biodegradable materials has increased the need to produce materials that combine appropriate functional properties at competitive costs. Thermoplastic starch and polyester blends are an interesting alternative to current materials due to the low cost of starch and the functional properties and processability of the resulting blends. Producing thermoplastic starch (TPS requires using a plasticiser at concentrations between 20 and 30%wt (in relation to starch. Glycerol is the most common plasticiser due to its high plasticising capacity and thermal stability at processing temperatures. The objective of this study was to evaluate glycerol waste from the biodiesel industry, with different degrees of purification, as plasticisers for TPS / poly (butylene adipate-co-terephthalate (PBAT blends. Different purities of glycerol produced films with similar mechanical, optical and barrier properties to those made with purified glycerol (99.7%. Therefore, crude glycerol is a renewable alternative plasticiser that reduces the cost of plasticisation by 6-fold.

  16. Dietary tools to modulate glycogen storage in gilthead seabream muscle: glycerol supplementation.

    Science.gov (United States)

    Silva, Tomé S; Matos, Elisabete; Cordeiro, Odete D; Colen, Rita; Wulff, Tune; Sampaio, Eduardo; Sousa, Vera; Valente, Luisa M P; Gonçalves, Amparo; Silva, Joana M G; Bandarra, Narcisa; Nunes, Maria Leonor; Dinis, Maria Teresa; Dias, Jorge; Jessen, Flemming; Rodrigues, Pedro M

    2012-10-24

    The quality and shelf life of fish meat products depend on the skeletal muscle's energetic state at slaughter, as meat decomposition processes can be exacerbated by energy depletion. In this study, we tested dietary glycerol as a way of replenishing muscle glycogen reserves of farmed gilthead seabream. Two diets were tested in duplicate (n = 42/tank). Results show 5% inclusion of crude glycerol in gilthead seabream diets induces increased muscle glycogen, ATP levels and firmness, with no deleterious effects in terms of growth, proximate composition, fatty acid profile, oxidative state, and organoleptic properties (aroma and color). Proteomic analysis showed a low impact of glycerol-supplementation on muscle metabolism, with most changes probably reflecting increased stress coping capacity in glycerol-fed fish. This suggests inclusion of crude glycerol in gilthead seabream diets (particularly in the finishing phase) seems like a viable strategy to increase glycogen deposition in muscle without negatively impacting fish welfare and quality.

  17. Green silicone elastomer obtained from a counterintuitively stable mixture of glycerol and PDMS

    DEFF Research Database (Denmark)

    Mazurek, P.; Hvilsted, S.; Skov, A. L.

    2016-01-01

    for obtaining elastomeric composites with uniformly distributed glycerol droplets. Various compositions, containing from 0 to 140 parts of glycerol per 100 parts of PDMS by weight, were prepared and investigated in terms of ATR-FTIR, broadband dielectric spectroscopy, mechanical properties as well as optical......A green and cheap silicone-based elastomer has been developed. Through the simple mixing-in of biodiesel-originating glycerol into commercially available polydimethylsiloxane (PDMS) pre-polymer, a glycerol-in-PDMS emulsion was produced. This counterintuitively stable mixture became a basis...... and scanning electron microscopy. The materials were proven additionally to exhibit a strong affinity to water, which was investigated by simple water absorption tests. Incorporating glycerol into PDMS decreased the Young's modulus of the composites yet the ultimate strain of the elastomer was not compromised...

  18. Salty glycerol versus salty water surface organization: bromide and iodide surface propensities.

    Science.gov (United States)

    Huang, Zishuai; Hua, Wei; Verreault, Dominique; Allen, Heather C

    2013-07-25

    Salty NaBr and NaI glycerol solution interfaces are examined in the OH stretching region using broadband vibrational sum frequency generation (VSFG) spectroscopy. Raman and infrared (IR) spectroscopy are used to further understand the VSFG spectroscopic signature. The VSFG spectra of salty glycerol solutions reveal that bromide and iodide anions perturb the interfacial glycerol organization in a manner similar as that found in aqueous halide salt solutions, thus confirming the presence of bromide and iodide anions at the glycerol surface. Surface tension measurements are consistent with the surface propensity suggested by the VSFG data and also show that the surface excess increases with increasing salt concentration, similar to that of water. In addition, iodide is shown to have more surface prevalence than bromide, as has also been determined from aqueous solutions. These results suggest that glycerol behaves similarly to water with respect to surface activity and solvation of halide anions at its air/liquid interface.

  19. Lipase-catalyzed simultaneous biosynthesis of biodiesel and glycerol carbonate from corn oil in dimethyl carbonate.

    Science.gov (United States)

    Min, Ji Young; Lee, Eun Yeol

    2011-09-01

    Biodiesel [fatty acid methyl esters (FAMEs)] and glycerol carbonate were synthesized from corn oil and dimethyl carbonate (DMC) via transesterification using lipase (Novozyme 435) in solvent-free reaction in which excess DMC was used as the substrate and reaction medium. Glycerol carbonate was also simultaneously formed from DMC and glycerol. Conversions of FAMEs and glycerol carbonate were examined in batch reactions. The FAMEs and glycerol carbonate reached 94 and 62.5% from oil and DMC (molar ratio of 1:10) with 0.2% (v/v) water and 10% (w/w) Novozyme 435 (based on oil weight) at 60 °C. When Novozyme 435 was washed with acetone after each reaction, more than 80% activity still remained after seven recycling.

  20. Performance of a direct glycerol fuel cell using KOH doped polybenzimidazole as electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Nascimento, Ana P.; Linares, Jose J., E-mail: joselinares@unb.br [Universidade de Brasilia (UnB), Brasilia, DF (Brazil). Instituto de Quimica

    2014-03-15

    This paper studies the influence of the operating variables (glycerol concentration, temperature and feed rate) for a direct glycerol fuel cell fed with glycerol using polybenzimidazole (PBI) impregnated with KOH as electrolyte and Pt/C as catalyst. Temperature displays a beneficial effect up to 75 °C due to the enhanced conductivity and kinetics of the electrochemical reactions. The optimum cell feed corresponds to 1 mol L{sup -1} glycerol and 4 mol L{sup -1} KOH, supplying sufficient quantities of fuel and electrolyte without massive crossover nor mass transfer limitations. The feed rate increases the performance up to a limit of 2 mL min{sup -1}, high enough to guarantee the access of the glycerol and the exit of the products. Finally, the use of binary catalysts (PtRu/C and Pt{sub 3}Sn/C) is beneficial for increasing the cell performance. (author)

  1. Modeling, Simulation and Optimization of Hydrogen Production Process from Glycerol using Steam Reforming

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jeongpil; Cho, Sunghyun; Kim, Tae-Ok; Shin, Dongil [Myongji University, Yongin (Korea, Republic of); Lee, Seunghwan [JNK Heaters, Seoul (Korea, Republic of); Moon, Dong Ju [Korea Institute of Science and Technology, Seoul (Korea, Republic of)

    2014-12-15

    For improved sustainability of the biorefinery industry, biorefinery-byproduct glycerol is being investigated as an alternate source for hydrogen production. This research designs and optimizes a hydrogen-production process for small hydrogen stations using steam reforming of purified glycerol as the main reaction, replacing existing processes relying on steam methane reforming. Modeling, simulation and optimization using a commercial process simulator are performed for the proposed hydrogen production process from glycerol. The mixture of glycerol and steam are used for making syngas in the reforming process. Then hydrogen are produced from carbon monoxide and steam through the water-gas shift reaction. Finally, hydrogen is separated from carbon dioxide using PSA. This study shows higher yield than former U.S.. DOE and Linde studies. Economic evaluations are performed for optimal planning of constructing domestic hydrogen energy infrastructure based on the proposed glycerol-based hydrogen station.

  2. Dietary glycerol for quail: association between productive performance and COX III mRNA expression.

    Science.gov (United States)

    Silva, S C C; Gasparino, E; Batista, E; Tanamati, F; Vesco, A P D; Lala, B; de Oliveira, D P

    2016-05-25

    This study was carry out to evaluate mRNA expression of mitochondrial cytochrome c oxidase III in the Pectoralis superficialis muscle of 28-day-old quails fed diets containing 0, 8, and 12% glycerol. Total RNA was extracted (N = 10) and cDNA was amplified using specifics primers for qRT-PCR. Feed efficiency and feed intake were evaluated. COX III mRNA expression in breast muscle was higher in the group fed with 12% glycerol (0.863 AU); no differences were observed in the expression of this gene between the muscle of animals fed diets without glycerol (0.357 AU) and 8% glycerol (0.415 AU). Quails that showed greater COX III mRNA expression also showed the lowest feed efficiency. These results show that there is a difference in COX III mRNA expression in breast muscle of 28-day-old quail fed diets different concentrations of glycerol.

  3. An effective method for improving the fertility of glycerol-exposed poultry semen.

    Science.gov (United States)

    Long, J A; Kulkarni, G

    2004-09-01

    Semen cryopreservation is necessary for banking germplasm from critical poultry stocks. To date, glycerol is the most effective cryoprotectant for poultry sperm; however, the contraceptive effects of glycerol require a significant reduction of the cryoprotectant from thawed semen before artificial insemination (AI). The effectiveness of glycerol reduction by dialysis, Percoll density gradient centrifugation, or washing through 12% (wt/vol) Accudenz was evaluated by fertility trials with highly inbred chicken research lines and commercial turkey lines. Semen was extended 1:1 and then diluted with glycerolized extender to yield a final 11% (vol/vol) glycerol concentration. Glycerolized rooster semen was aliquoted for control, Accudenz centrifugation, and dialysis treatments. A total of 90 pure line and 85 F1 hybrid chicken hens were each inseminated with 100 x 10(6) sperm at 7-d intervals for 4 to 6 wk. All eggs from the glycerolized control semen treatments were infertile, and fertility rates from dialyzed semen decreased steadily from 26.4 to 0% within the first 4 wk for the pure lines. In contrast, fertility rates for Accudenz-processed semen increased from 17.9 to 37.17% during the first 4 wk. Similar fertility rates occurred with the F1 hybrid cross lines. For turkey fertility trials, the dialysis treatment was not used; glycerolized turkey semen was processed by Accudenz or Percoll centrifugation to reduce glycerol. A total of 36 hens were inseminated with 150 x 10(6) sperm at 7-d intervals for 6 wk. Similar to the chicken trials, fertility rates of Accudenz-processed semen steadily increased to 49.4% by the sixth week of insemination. The average fertility of Percoll-processed semen was only 19.1%. These data demonstrate that Accudenz centrifugation is an acceptable glycerol reduction method for nonfrozen poultry semen.

  4. The metabolic costs of improving ethanol yield by reducing glycerol formation capacity under anaerobic conditions in Saccharomyces cerevisiae

    NARCIS (Netherlands)

    Pagliardini, Julien; Hubmann, Georg; Alfenore, Sandrine; Nevoigt, Elke; Bideaux, Carine; Guillouet, Stephane E.

    2013-01-01

    Background: Finely regulating the carbon flux through the glycerol pathway by regulating the expression of the rate controlling enzyme, glycerol-3-phosphate dehydrogenase (GPDH), has been a promising approach to redirect carbon from glycerol to ethanol and thereby increasing the ethanol yield in eth

  5. Palladium-based telomerization of1,3-buta diene with glycerol using methoxy-functionalized triphenylphosphine ligands

    NARCIS (Netherlands)

    Palkovits, R.; Nieddu, I.; Kruithof, C.A.; Klein Gebbink, R.J.M.; Weckhuysen, B.M.

    2008-01-01

    Glycerol is considered a potential renewable building block for the synthesis of existing as well as new chemicals. A promising route is the telomerization of 1,3-butadiene with glycerol leading to C8 chain ethers of glycerol with applications in, for example, surfactant chemistry. Recently, we repo

  6. Molecular dynamics simulations of glycerol glass-forming liquid

    Energy Technology Data Exchange (ETDEWEB)

    Blieck, J. [Laboratoire de Dynamique et Structure des Materiaux Moleculaires, CNRS UMR 8024, BAT P5-Cite Scientifique, Universite Lille I, 59655 Villeneuve d' Ascq Cedex (France); Affouard, F. [Laboratoire de Dynamique et Structure des Materiaux Moleculaires, CNRS UMR 8024, BAT P5-Cite Scientifique, Universite Lille I, 59655 Villeneuve d' Ascq Cedex (France)], E-mail: frederic.affouard@univ-lille1.fr; Bordat, P. [Laboratoire de Dynamique et Structure des Materiaux Moleculaires, CNRS UMR 8024, BAT P5-Cite Scientifique, Universite Lille I, 59655 Villeneuve d' Ascq Cedex (France); Lerbret, A. [Laboratoire de Dynamique et Structure des Materiaux Moleculaires, CNRS UMR 8024, BAT P5-Cite Scientifique, Universite Lille I, 59655 Villeneuve d' Ascq Cedex (France); Descamps, M. [Laboratoire de Dynamique et Structure des Materiaux Moleculaires, CNRS UMR 8024, BAT P5-Cite Scientifique, Universite Lille I, 59655 Villeneuve d' Ascq Cedex (France)

    2005-10-31

    Structural and dynamical properties of liquid glycerol have been investigated by Molecular Dynamics simulations. An improved model based on a slight reparametrisation of the all-atoms AMBER force field used in [R. Chelli, P. Procacci, G. Cardini, R.G.D. Valle, S. Califano, Phys. Chem. Chem. Phys. 1 (1999) 871] is presented. The structure remains satisfactory, qualitatively similar to that obtained from the original model. This new model is also found to reproduce significantly better the diffusion coefficient and the correlations times as they can be deduced from neutron spin echo (NSE) experiments. Structural heterogeneities revealed as a pre-peak of the static structure factor S(Q) close to Q {approx} 0.6 A{sup -1} are observed. Our results are also found compatible with predictions of the Mode Coupling Theory.

  7. Kinetic mechanism of indole-3-glycerol phosphate synthase.

    Science.gov (United States)

    Schlee, Sandra; Dietrich, Susanne; Kurćon, Tomasz; Delaney, Pamela; Goodey, Nina M; Sterner, Reinhard

    2013-01-08

    The (βα)(8)-barrel enzyme indole-3-glycerol phosphate synthase (IGPS) catalyzes the multistep transformation of 1-(o-carboxyphenylamino)-1-deoxyribulose 5-phosphate (CdRP) into indole-3-glycerol phosphate (IGP) in tryptophan biosynthesis. Mutagenesis data and crystal structure analysis of IGPS from Sulfolobus solfataricus (sIGPS) allowed for the formulation of a plausible chemical mechanism of the reaction, and molecular dynamics simulations suggested that flexibility of active site loops might be important for catalysis. Here we developed a method that uses extrinsic fluorophores attached to active site loops to connect the kinetic mechanism of sIGPS to structure and conformational motions. Specifically, we elucidated the kinetic mechanism of sIGPS and correlated individual steps in the mechanism to conformational motions of flexible loops. Pre-steady-state kinetic measurements of CdRP to IGP conversion monitoring changes in intrinsic tryptophan and IGP fluorescence provided a minimal three-step kinetic model in which fast substrate binding and chemical transformation are followed by slow product release. The role of sIGPS loop conformational motion during substrate binding and catalysis was examined via variants that were covalently labeled with fluorescent dyes at the N-terminal extension of the enzyme and mobile active site loop β1α1. Analysis of kinetic data monitoring dye fluorescence revealed a conformational change that follows substrate binding, suggesting an induced-fit-type binding mechanism for the substrate CdRP. Global fitting of all kinetic results obtained with wild-type sIGPS and the labeled variants was best accommodated by a four-step kinetic model. In this model, both the binding of CdRP and its on-enzyme conversion to IGP are accompanied by conformational transitions. The liberation of the product from the active site is the rate-limiting step of the overall reaction. Our results confirm the importance of flexible active loops for substrate

  8. Rizotomia trigeminal por radiofrequência para tratamento da neuralgia do trigêmeo: resultados e modificação técnica Trigeminal radiofrequency rhizotomy for the treatment of trigeminal neuralgia: results and technical modification

    Directory of Open Access Journals (Sweden)

    Sebastião Gusmão

    2003-06-01

    Full Text Available O objetivo deste estudo é avaliar a eficácia da rizotomia trigeminal por radiofrequência no tratamento da neuralgia essencial do trigêmeo em 135 pacientes e propor modificação da técnica para guiar a punção do forame oval. Cento e um (74,8% pacientes foram tratados com apenas um procedimento cirúrgico e os 34 (25,2% restantes necessitaram dois procedimentos. O tempo de avaliação pós-operatória variou de 6 meses a 15 anos. O alívio das crises de dor no pós-operatório imediato ocorreu em 131 (97,0% pacientes. Após a realização do primeiro procedimento, houve recorrência em 33 (24,5% pacientes. As complicações incluíram diminuição do reflexo corneano (4,4%, paresia do masseter (2,2%, disestesia dolorosa (1,5% e anestesia dolorosa (0,7%. A rizotomia trigeminal por radiofrequência constitui procedimento minimamente invasivo, de baixo risco e com alta eficácia. O uso da fluoroscopia por tomografia computadorizada torna a punção do forame oval mais fácil, rápida e precisa.The purpose of this study was to evaluate the efficacy of radiofrequency trigeminal rhizotomy in treating 135 patients harboring trigeminal neuralgia, and to introduce a technical modification to guide the puncture of the foramen ovale. A hundred and one (74.8% patients were treated with a single surgical procedure whereas the 34 (25.2% remaining patients required two procedures. Follow-up ranges from 6 months to 15 years. Pain relief in the immediate postoperative was achieved in 131 (97.0% patients. After the initial procedure, recurrence happened in 33 (24.5% patients. The complications included decrease corneal reflex (4.4%, masseter paresis (2.2%, painful dysesthesia (1.5% and anesthesia dolorosa (0.7%. The radiofrequency trigeminal rizhotomy is a low risk, highly effective and minimally invasive procedure. The use of the computerized tomography guided fluoroscopy turns foramen ovale's puncture easier, fast and precise.

  9. Metabolism of Glycerol, Glucose, and Lactate in the Citric Acid Cycle Prior to Incorporation into Hepatic Acylglycerols*

    Science.gov (United States)

    Jin, Eunsook S.; Sherry, A. Dean; Malloy, Craig R.

    2013-01-01

    During hepatic lipogenesis, the glycerol backbone of acylglycerols originates from one of three sources: glucose, glycerol, or substrates passing through the citric acid cycle via glyceroneogenesis. The relative contribution of each substrate source to glycerol in rat liver acylglycerols was determined using 13C-enriched substrates and NMR. Animals received a fixed mixture of glucose, glycerol, and lactate; one group received [U-13C6]glucose, another received [U-13C3]glycerol, and the third received [U-13C3]lactate. After 3 h, the livers were harvested to extract fats, and the glycerol moiety from hydrolyzed acylglycerols was analyzed by 13C NMR. In either fed or fasted animals, glucose and glycerol provided the majority of the glycerol backbone carbons, whereas the contribution of lactate was small. In fed animals, glucose contributed >50% of the total newly synthesized glycerol backbone, and 35% of this contribution occurred after glucose had passed through the citric acid cycle. By comparison, the glycerol contribution was ∼40%, and of this, 17% of the exogenous glycerol passed first through the cycle. In fasted animals, exogenous glycerol became the major contributor to acylglycerols. The contribution from exogenous lactate did increase in fasted animals, but its overall contribution remained small. The contributions of glucose and glycerol that had passed through the citric acid cycle first increased in fasted animals from 35 to 71% for glucose and from 17 to 24% for glycerol. Thus, a substantial fraction from both substrate sources passed through the cycle prior to incorporation into the glycerol moiety of acylglycerols in the liver. PMID:23572519

  10. Metabolism of glycerol, glucose, and lactate in the citric acid cycle prior to incorporation into hepatic acylglycerols.

    Science.gov (United States)

    Jin, Eunsook S; Sherry, A Dean; Malloy, Craig R

    2013-05-17

    During hepatic lipogenesis, the glycerol backbone of acylglycerols originates from one of three sources: glucose, glycerol, or substrates passing through the citric acid cycle via glyceroneogenesis. The relative contribution of each substrate source to glycerol in rat liver acylglycerols was determined using (13)C-enriched substrates and NMR. Animals received a fixed mixture of glucose, glycerol, and lactate; one group received [U-(13)C6]glucose, another received [U-(13)C3]glycerol, and the third received [U-(13)C3]lactate. After 3 h, the livers were harvested to extract fats, and the glycerol moiety from hydrolyzed acylglycerols was analyzed by (13)C NMR. In either fed or fasted animals, glucose and glycerol provided the majority of the glycerol backbone carbons, whereas the contribution of lactate was small. In fed animals, glucose contributed >50% of the total newly synthesized glycerol backbone, and 35% of this contribution occurred after glucose had passed through the citric acid cycle. By comparison, the glycerol contribution was ~40%, and of this, 17% of the exogenous glycerol passed first through the cycle. In fasted animals, exogenous glycerol became the major contributor to acylglycerols. The contribution from exogenous lactate did increase in fasted animals, but its overall contribution remained small. The contributions of glucose and glycerol that had passed through the citric acid cycle first increased in fasted animals from 35 to 71% for glucose and from 17 to 24% for glycerol. Thus, a substantial fraction from both substrate sources passed through the cycle prior to incorporation into the glycerol moiety of acylglycerols in the liver.

  11. Systematic Engineering of Escherichia coli for d-Lactate Production from Crude Glycerol.

    Science.gov (United States)

    Wang, Zei Wen; Saini, Mukesh; Lin, Li-Jen; Chiang, Chung-Jen; Chao, Yun-Peng

    2015-11-04

    Crude glycerol resulting from biodiesel production is an abundant and renewable resource. However, the impurities in crude glycerol usually make microbial fermentation problematic. This issue was addressed by systematic engineering of Escherichia coli for the production of d-lactate from crude glycerol. First, mgsA and the synthetic pathways of undesired products were eliminated in E. coli, rendering the strain capable of homofermentative production of optically pure d-lactate. To direct carbon flux toward d-lactate, the resulting strain was endowed with an enhanced expression of glpD-glpK in the glycerol catabolism and of a heterologous gene encoding d-lactate dehydrogenase. Moreover, the strain was evolved to improve its utilization of cruder glycerol and subsequently equipped with the FocA channel to export intracellular d-lactate. Finally, the fed-batch fermentation with two-phase culturing was carried out with a bioreactor. As a result, the engineered strain enabled production of 105 g/L d-lactate (99.9% optical purity) from 121 g/L crude glycerol at 40 h. The result indicates the feasibility of our approach to engineering E. coli for the crude glycerol-based fermentation.

  12. Hydrogenolysis of Glycerol to 1,2-Propanediol Over Clay Based Catalysts.

    Science.gov (United States)

    Lee, Sang-Yong; Jung, Jae-Sun; Yang, Eun-Hyeok; Lee, Kwan-Young; Moon, Dong Ju

    2015-11-01

    1,2-propanediol (1,2-PDO) is one of the promising product among the valuable products derived from glycerol and it can be obtained by the catalytic hydrogenolysis of glycerol. Copper-supported clay-based catalysts were prepared with different pore sizes using various ratios of kaolin, Mg, and Al by coprecipitation and applied in the selective hydrogenolysis of glycerol to 1,2-PDO. In recent research, variations of pore volume and pore size could affect the diffusion of reagents within the catalyst due to the collision between reagents or pore wall and reagents. It changes selectivities of each product in hydrogenolysis of glycerol reaction. The physico-chemical properties of the catalysts were analyzed by XRD, N2 physisorption, TPR, CO2-TPD, SEM, and a mercury porosimeter. The Cu/TALCITE 4 catalyst showed 98% 1,2-PDO selectivity with 65% glycerol conversion under the optimized condition of 190 degrees C, 25 bar, and 20 wt% glycerol aqueous solution. It was found that the basic strength and meso-macro pore structure of the catalysts play an important role in glycerol conversion and 1,2-PDO selectivity.

  13. Metabolic engineering of the ethanol fermentation by Saccharomyces cerevisiae away from glycerol formation towards alternative products

    Energy Technology Data Exchange (ETDEWEB)

    Kumar Jain, V.; Divol, B.; Prior, B.; Franz Bauer, F. [Stellenbosch Univ., (South Africa). Inst. for Wine Biotechnology

    2009-07-01

    This study investigated the commercial advantage of eliminating glycerol from the ethanol fermentation process and possible replacement with other value products. Under fermentative conditions yeast re-oxidizes excess NADH through glycerol production which involves NADH-dependent glycerol-3-phosphate dehydrogenase. Deletion of these two genes renders the cells incapable of maintaining fermentative activity under anaerobic conditions due to accumulation of NADH. This study examined the feasibility of converting this excess NADH to Nad by transforming a glycerol synthesizing double mutant with genes that could restore the redox balance in the yeast. The study showed that although glycerol formation can be eliminated during fermentation, no alternative redox balancing pathway is as efficient at the glycerol pathway in maintaining fermentation. Alternative products such as sorbitol and 1,2propanediol can be produced instead of glycerol, but these genetic manipulations were shown to have negative effects on fermentative ability. Ethanol yields, but not concentrations, were improved in mutants. Significant amounts of acetate were also produced. This paper discussed the metabolic and biotechnological implications of these findings. tabs., figs.

  14. PURIFICATION OF CRUDE GLYCEROL FROM INDUSTRIAL WASTE: EXPERIMENTAL AND SIMULATION STUDIES

    Directory of Open Access Journals (Sweden)

    WAN NOR ROSLAM WAN ISAHAK

    2016-08-01

    Full Text Available In this study, the purification of crude glycerol as a by-product of transesterification reaction was investigated. The first purification stage of the crude glycerol was achieved by employing the neutralization method, followed by microfiltration using 0.45µm filter membrane. Only glycerol peak could be detected by high performance liquid chromatography analysis which indicating that the neutralization step enabled to removal of excess homogeneous catalyst as well as the unreacted free fatty acids from crude glycerol samples. However, the free ions from salt and catalyst were then eliminated through an ion exchange process using two types of Amberlite resins to produce higher glycerol purity up to 99.4%. The purity of glycerol was confirmed by the other analysis such as the Fourier transform infrared, United States Pharmacopoeia and American society for testing and materials methods. The simulation studies were applied using Super-Pro-Designer 7.0 software which can provide the data for scale up to industrial scale. The P2 and P5 simulation process gives a higher purity of pure glycerol of 98.35 wt.% and 99.27 wt%, respectively were generated after through several combinatorial purification steps. The combination between the experimental and simulation process showed a good way to investigate the laboratory experiment input for possible industry scale in future.

  15. Application of Glycerol for Induced Powdery Mildew Resistance in Triticum aestivum L.

    Science.gov (United States)

    Li, Yinghui; Song, Na; Zhao, Chuanzhi; Li, Feng; Geng, Miaomiao; Wang, Yuhui; Liu, Wanhui; Xie, Chaojie; Sun, Qixin

    2016-01-01

    Previous work has demonstrated that glycerol-3-phosphate (G3P) and oleic acid (18:1) are two important signal molecules associated with plant resistance to fungi. In this article, we provide evidence that a 3% glycerol spray application 1-2 days before powdery mildew infection and subsequent applications once every 4 days was sufficient to stimulate the plant defense responses without causing any significant damage to wheat leaves. We found that G3P and oleic acid levels were markedly induced by powdery mildew infection. In addition, TaGLI1 (encoding a glycerol kinase) and TaSSI2 (encoding a stearoylacyl carrier protein fatty acid desaturase), two genes associated with the glycerol and fatty acid (FA) pathways, respectively, were induced by powdery mildew infection, and their promoter regions contain some fungal response elements. Moreover, exogenous application of glycerol increased the G3P level and decreased the level of oleic acid (18:1). Glycerol application induced the expression of pathogenesis-related (PR) genes (TaPR-1, TaPR-2, TaPR-3, TaPR-4, and TaPR-5), induced the generation of reactive oxygen species (ROS) before powdery mildew infection, and induced salicylic acid (SA) accumulation in wheat leaves. Further, we sprayed glycerol in a wheat field and found that it significantly (p powdery mildew disease and lessened disease-associated kernel weight loss, all without causing any noticeable degradation in wheat seed quality.

  16. Trehalose in glycerol-free freezing extender enhances post-thaw survival of boar spermatozoa.

    Science.gov (United States)

    Athurupana, Rukmali; Takahashi, Daisen; Ioki, Sumire; Funahashi, Hiroaki

    2015-01-01

    Cryopreservation of boar semen is still considered suboptimal due to lower fertility as compared with fresh samples when glycerol, a permeating cryoprotectant, is used. Trehalose is a non-permeable cryoprotectant and nonreducing disaccharide known to stabilize proteins and biologic membranes. The aim of this study was to evaluate the cryosurvival and in vitro penetrability of boar spermatozoa when glycerol was replaced with trehalose in a freezing extender. Ejaculated Berkshire semen samples were diluted in egg yolk-based freezing extender containing glycerol (100 mM) or trehalose (0, 50, 100, 150, 200 and 250 mM) and cryopreserved using a straw freezing procedure. Thawed samples were analyzed for motility, viability, mitochondrial membrane potential (MMP), and acrosome integrity. In experiment 2, penetrability of spermatozoa cryopreserved with 100 mM glycerol or trehalose was examined. Replacement of cryoprotectant glycerol (100 mM) with trehalose had no effect on sperm viability, but replacing it with 100 mM trehalose improved motility, MMP and acrosome integrity significantly. Sperm motility and MMP were considerably higher in 100 mM trehalose, whereas the acrosome integrity was substantially higher in 100-250 mM trehalose. The in vitro penetration rate was also significantly higher in spermatozoa cryopreserved with trehalose (61.3%) than in those cryopreserved with glycerol (43.6%). In conclusion, 100 mM non-permeable trehalose can be used to replace glycerol, a permeating cryoprotectant, for maintenance of better post-thaw quality of boar spermatozoa.

  17. Effect of water polyamorphism on the molecular vibrations of glycerol in its glassy aqueous solutions.

    Science.gov (United States)

    Suzuki, Yoshiharu; Mishima, Osamu

    2016-07-14

    A glassy dilute glycerol-water solution undergoes a mutual polyamorphic transition relating to the transition between high- and low-density amorphous ices of solvent water. The polyamorphic transition behavior depends on the glycerol concentration, indicating that the glycerol affects the water polyamorphism. Here, we used the glassy dilute glycerol-water solution of the solute molar fraction of 0.07 and examined the effect of the polyamorphic change in solvent water on the molecular vibrations of glycerol via Raman spectroscopy. It is found that the molecular vibration of glycerol in high-density liquid like solvent water is different from that in the low-density liquid like solvent water and that the change in the molecular vibration of glycerol is synchronized with the polyamorphic transition of solvent water. The dynamical change of the solute molecule relates to the polyamorphic state of solvent water. This result suggests that the polyamorphic fluctuation of water structure emanated from the presumed liquid-liquid critical point plays an important role for the function of aqueous solution under an ambient condition such as the conformational stability of solute, the functional expression of solute, and so on.

  18. Bio-hydrogen production from glycerol by a strain of Enterobacter aerogenes

    Energy Technology Data Exchange (ETDEWEB)

    Marques, P.A.S.S; Bartolomeu, M.L.; Tome, M.M.; Rosa, M.F. [INETI, Unit of Biomass/Renewable Energy Department, Estrada do Paco do Lumiar, 22, 1649-038 Lisboa (Portugal)

    2008-07-01

    The goal of this work was to evaluate the H2 production from glycerol-containing byproducts obtained from biodiesel industrial production, using Enterobacter aerogenes ATCC 13048 Sputum. H2 production using as substrate pure glycerol and glycerol-containing biodiesel byproducts was compared. The effect of parameters such as initial substrate concentration and sodium chloride addition on the bio-hydrogen production efficiency was also investigated. The results showed that using 10 g/L of pure glycerol or biodiesel residues, containing the same concentration of glycerol as substrate, lead to similar bio-hydrogen productions (3.46 LH2/L and 3.28 LH2/L fermentation medium, respectively). This indicates that the performance of the E. aerogenes strain used was not influenced by the presence of other components than glycerol in biodiesel residues, at least for the tested waste concentration range. When sodium chloride was added to the fermentation medium with pure 10 g/L glycerol, H2 production was not affected (3.34 LH2/L fermentation medium), showing that metabolism of the E. aerogenes strain was not inhibited by this biodiesel waste component up to 4 g/L chloride concentration. Biodiesel residues used without sterilization provided a higher H2 production (1.03 L) than the ones submitted to previous sterilization in autoclave (0.89 L).

  19. Fermentation of glycerol into ethanol in a microbial electrolysis cell driven by a customized consortium.

    Science.gov (United States)

    Speers, Allison M; Young, Jenna M; Reguera, Gemma

    2014-06-03

    The in situ generation of ethanol from glycerol-containing wastewater shows promise to improve the economics of the biodiesel industry. Consequently, we developed a microbial electrolysis cell (MEC) driven by the synergistic metabolisms of the exoelectrogen Geobacter sulfurreducens and the bacterium Clostridium cellobioparum, which fermented glycerol into ethanol in high yields (90%) and produced fermentative byproducts that served as electron donors for G. sulfurreducens. Syntrophic cooperation stimulated glycerol consumption, ethanol production, and the conversion of fermentation byproducts into cathodic H2 in the MEC. The platform was further improved by adaptively evolving glycerol-tolerant strains with robust growth at glycerol loadings typical of biodiesel wastewater and by increasing the buffering capacity of the anode medium. This resulted in additional increases in glycerol consumption (up to 50 g/L) and ethanol production (up to 10 g/L) at rates that greatly exceeded the capacity of the anode biofilms to concomitantly remove the fermentation byproducts. As a result, 1,3-propanediol was generated as a metabolic sink for electrons not converted into electricity syntrophically. The results highlight the potential of consortia to process glycerol in MECs and provide insights into genetic engineering and system design approaches that can be implemented to further improve MEC performance to satisfy industrial needs.

  20. Effect of water polyamorphism on the molecular vibrations of glycerol in its glassy aqueous solutions

    Science.gov (United States)

    Suzuki, Yoshiharu; Mishima, Osamu

    2016-07-01

    A glassy dilute glycerol-water solution undergoes a mutual polyamorphic transition relating to the transition between high- and low-density amorphous ices of solvent water. The polyamorphic transition behavior depends on the glycerol concentration, indicating that the glycerol affects the water polyamorphism. Here, we used the glassy dilute glycerol-water solution of the solute molar fraction of 0.07 and examined the effect of the polyamorphic change in solvent water on the molecular vibrations of glycerol via Raman spectroscopy. It is found that the molecular vibration of glycerol in high-density liquid like solvent water is different from that in the low-density liquid like solvent water and that the change in the molecular vibration of glycerol is synchronized with the polyamorphic transition of solvent water. The dynamical change of the solute molecule relates to the polyamorphic state of solvent water. This result suggests that the polyamorphic fluctuation of water structure emanated from the presumed liquid-liquid critical point plays an important role for the function of aqueous solution under an ambient condition such as the conformational stability of solute, the functional expression of solute, and so on.

  1. Production of fumaric acid from biodiesel-derived crude glycerol by Rhizopus arrhizus.

    Science.gov (United States)

    Zhou, Yuqing; Nie, Kaili; Zhang, Xin; Liu, Shihong; Wang, Meng; Deng, Li; Wang, Fang; Tan, Tianwei

    2014-07-01

    This work investigated the capability of Rhizopus arrhizus to assimilate biodiesel-derived crude glycerol and convert it into fumaric acid. After optimizing the initial glycerol concentration, spore inoculum and yeast extract concentration, smaller pellets (0.7 mm) and higher biomass (3.11 g/L) were obtained when R. arrhizus grew on crude glycerol. It was found that crude glycerol was more suitable than glucose for smaller R. arrhizus pellet forming. When 80 g/L crude glycerol was used as carbon source, the fumaric acid production of 4.37 g/L was obtained at 192 h. With a highest concentration of 22.81 g/L achieved in the co-fermentation of crude glycerol (40 g/L) and glucose (40 g/L) at 144 h, the fumaric acid production was enhanced by 553.6%, compared to the fermentation using glycerol (80 g/L) as sole carbon source. Moreover, the production cost of fumaric acid in co-fermentation was reduced by approximately 14% compared to glucose fermentation.

  2. Atrial natriuretic peptide stimulates lipid mobilization during repeated bouts of endurance exercise.

    Science.gov (United States)

    Moro, Cédric; Polak, Jan; Hejnova, Jindra; Klimcakova, Eva; Crampes, François; Stich, Vladimir; Lafontan, Max; Berlan, Michel

    2006-05-01

    Atrial natriuretic peptide (ANP) controls lipolysis in human adipocytes. Lipid mobilization is increased during repeated bouts of exercise, but the underlying mechanisms involved in this process have not yet been delineated. The relative involvement of catecholamine- and ANP-dependent pathways in the control of lipid mobilization during repeated bouts of exercise was thus investigated in subcutaneous adipose tissue (SCAT) by microdialysis. The study was performed in healthy males. Subjects performed two 45-min exercise bouts (E1 and E2) at 50% of their maximal oxygen uptake separated by a 60-min rest period. Extracellular glycerol concentration (EGC), reflecting SCAT lipolysis, was measured in a control probe perfused with Ringer solution and in two other probes perfused with either Ringer plus phentolamine (alpha(1/2)-AR antagonist) or Ringer plus both phentolamine and propranolol (beta-AR antagonist). Plasma epinephrine, plasma glycerol, and EGC were 1.7-, 1.6-, and 1.2-fold higher in E2 than in E1, respectively. Phentolamine potentiated exercise-induced EGC increase during E2 only. Propranolol reduced the lipolytic rate during both E1 and E2 compared with the probe with phentolamine. Plasma ANP concentration increased more during E2 than during E1 and was correlated with the increase in EGC in the probe containing phentolamine plus propranolol. The results suggest that ANP is involved in the control of lipolysis during exercise and that it contributes to stimulation of lipolysis during repeated bouts of exercise.

  3. Concentrations and abundance ratios of long-chain alkenones and glycerol dialkyl glycerol tetraethers in sinking particles south of Java

    Science.gov (United States)

    Chen, Wenwen; Mohtadi, Mahyar; Schefuß, Enno; Mollenhauer, Gesine

    2016-06-01

    In this study, we obtained concentrations and abundance ratios of long-chain alkenones and glycerol dialkyl glycerol tetraethers (GDGTs) in a one-year time-series of sinking particles collected with a sediment trap moored from December 2001 to November 2002 at 2200 m water depth south of Java in the eastern Indian Ocean. We investigate the seasonality of alkenone and GDGT fluxes as well as the potential habitat depth of the Thaumarchaeota producing the GDGTs entrained in sinking particles. The alkenone flux shows a pronounced seasonality and ranges from 1 μg m-2 d-1 to 35 μg m-2 d-1. The highest alkenone flux is observed in late September during the Southeast monsoon, coincident with high total organic carbon fluxes as well as high net primary productivity. Flux-weighted mean temperature for the high flux period using the alkenone-based sea-surface temperature (SST) index U37K‧ is 26.7 °C, which is similar to satellite-derived Southeast (SE) monsoon SST (26.4 °C). The GDGT flux displays a weaker seasonality than that of the alkenones. It is elevated during the SE monsoon period compared to the Northwest (NW) monsoon and intermonsoon periods (approximately 2.5 times), which is probably related to seasonal variation of the abundance of Thaumarchaeota, or to enhanced export of GDGTs by aggregation with sinking phytoplankton detritus. Flux-weighted mean temperature inferred from the GDGT-based TEX86H index is 26.2 °C, which is 1.8 °C lower than mean annual (ma) SST but similar to SE monsoon SST. As the time series of TEX86H temperature estimates, however, does not record a strong seasonal amplitude, we infer that TEX86H reflects ma upper thermocline temperature at approximately 50 m water depth.

  4. Reaction pathways for catalytic gas-phase oxidation of glycerol over mixed metal oxides

    Energy Technology Data Exchange (ETDEWEB)

    Suprun, W.; Glaeser, R.; Papp, H. [Leipzig Univ. (Germany). Inst. of Chemical Technology

    2011-07-01

    Glycerol as a main by-product from bio-diesel manufacture is a cheap raw material with large potential for chemical or biochemical transformations to value-added C3-chemicals. One possible way of glycerol utilization involves its catalytic oxidation to acrylic acid as an alternative to petrochemical routes. However, this catalytic conversion exhibits various problems such as harsh reaction conditions, severe catalyst coking and large amounts of undesired by-products. In this study, the reaction pathways for gas-phase conversion of glycerol over transition metal oxides (Mo, V und W) supported on TiO{sub 2} and SiO{sub 2} were investigated by two methods: (i) steady state experiments of glycerol oxidation and possible reactions intermediates, i.e., acrolein, 3-hydroxy propionaldehyde and acetaldehyde, and (ii) temperature-programmed surface reaction (TPSR) studies of glycerol conversion in the presence and in the absence of gas-phase oxygen. It is shown that the supported W-, V and Mo-oxides possess an ability to catalyze the oxidation of glycerol to acrylic acid. These investigations allowed us to gain a deeper insight into the reaction mechanism. Thus, based on the obtained results, three possible reactions pathways for the selective oxidation of glycerol to acrylic acid on the transition metal-containing catalysts are proposed. The major pathways in presence of molecular oxygen are a fast successive destructive oxidation of glycerol to CO{sub x} and the dehydration of glycerol to acrolein which is a rate-limiting step. (orig.)

  5. Optimal Conditions for Biomass and Recombinant Glycerol Kinase Production Using the Yeast Pichia pastoris

    Directory of Open Access Journals (Sweden)

    Sandro R. Valentini

    2011-01-01

    Full Text Available The extracellular glycerol kinase gene from Saccharomyces cerevisiae (GUT1 was cloned into the expression vector pPICZα A and integrated into the genome of the methylotrophic yeast Pichia pastoris X-33. The presence of the GUT1 insert was confirmed by PCR analysis. Four clones were selected and the functionality of the recombinant enzyme was assayed. Among the tested clones, one exhibited glycerol kinase activity of 0.32 U/mL, with specific activity of 0.025 U/mg of protein. A medium optimized for maximum biomass production by recombinant Pichia pastoris in shaker cultures was initially explored, using 2.31 % (by volume glycerol as the carbon source. Optimization was carried out by response surface methodology (RSM. In preliminary experiments, following a Plackett-Burman design, glycerol volume fraction (φ(Gly and growth time (t were selected as the most important factors in biomass production. Therefore, subsequent experiments, carried out to optimize biomass production, followed a central composite rotatable design as a function of φ(Gly and time. Glycerol volume fraction proved to have a significant positive linear effect on biomass production. Also, time was a significant factor (at linear positive and quadratic levels in biomass production. Experimental data were well fitted by a convex surface representing a second order polynomial model, in which biomass is a function of both factors (R²=0.946. Yield and specific activity of glycerol kinase were mainly affected by the additions of glycerol and methanol to the medium. The optimized medium composition for enzyme production was: 1 % yeast extract, 1 % peptone, 100 mM potassium phosphate buffer, pH=6.0, 1.34 % yeast nitrogen base (YNB, 4·10^–5 % biotin, 1 % methanol and 1 % glycerol, reaching 0.89 U/mL of glycerol kinase activity and 14.55 g/L of total protein in the medium after 48 h of growth.

  6. Energy recovery from waste glycerol by utilizing thermal water vapor plasma.

    Science.gov (United States)

    Tamošiūnas, Andrius; Valatkevičius, Pranas; Gimžauskaitė, Dovilė; Jeguirim, Mejdi; Mėčius, Vladas; Aikas, Mindaugas

    2017-04-01

    Glycerol, considered as a waste feedstock resulting from biodiesel production, has received much attention in recent years due to its properties, which offer to recover energy. The aim of this study was to investigate the use of a thermal water vapor plasma for waste (crude) glycerol conversion to synthesis gas, or syngas (H2 + CO). In parallel of crude glycerol, a pure glycerol (99.5%) was used as a reference material in order to compare the concentrations of the formed product gas. A direct current (DC) arc plasma torch stabilized by a mixture of argon/water vapor was utilized for the effective glycerol conversion to hydrogen-rich synthesis gas. It was found that after waste glycerol treatment, the main reaction products were gases with corresponding concentrations of H2 50.7%, CO 23.53%, CO2 11.45%, and CH4 3.82%, and traces of C2H2 and C2H6, which concentrations were below 0.5%. The comparable concentrations of the formed gas products were obtained after pure glycerol conversion-H2 46.4%, CO 26.25%, CO2 11.3%, and CH4 4.7%. The use of thermal water vapor plasma producing synthesis gas is an effective method to recover energy from both crude and pure glycerol. The performance of the glycerol conversion system was defined in terms of the produced gas yield, the carbon conversion efficiency, the cold gas efficiency, and the specific energy requirements.

  7. Expansion of protein domain repeats.

    Directory of Open Access Journals (Sweden)

    Asa K Björklund

    2006-08-01

    Full Text Available Many proteins, especially in eukaryotes, contain tandem repeats of several domains from the same family. These repeats have a variety of binding properties and are involved in protein-protein interactions as well as binding to other ligands such as DNA and RNA. The rapid expansion of protein domain repeats is assumed to have evolved through internal tandem duplications. However, the exact mechanisms behind these tandem duplications are not well-understood. Here, we have studied the evolution, function, protein structure, gene structure, and phylogenetic distribution of domain repeats. For this purpose we have assigned Pfam-A domain families to 24 proteomes with more sensitive domain assignments in the repeat regions. These assignments confirmed previous findings that eukaryotes, and in particular vertebrates, contain a much higher fraction of proteins with repeats compared with prokaryotes. The internal sequence similarity in each protein revealed that the domain repeats are often expanded through duplications of several domains at a time, while the duplication of one domain is less common. Many of the repeats appear to have been duplicated in the middle of the repeat region. This is in strong contrast to the evolution of other proteins that mainly works through additions of single domains at either terminus. Further, we found that some domain families show distinct duplication patterns, e.g., nebulin domains have mainly been expanded with a unit of seven domains at a time, while duplications of other domain families involve varying numbers of domains. Finally, no common mechanism for the expansion of all repeats could be detected. We found that the duplication patterns show no dependence on the size of the domains. Further, repeat expansion in some families can possibly be explained by shuffling of exons. However, exon shuffling could not have created all repeats.

  8. DWI Repeaters and Non-Repeaters: A Comparison.

    Science.gov (United States)

    Weeber, Stan

    1981-01-01

    Discussed how driving-while-intoxicated (DWI) repeaters differed signigicantly from nonrepeaters on 4 of 23 variables tested. Repeaters were more likely to have zero or two dependent children, attend church frequently, drink occasionally and have one or more arrests for public intoxication. (Author)

  9. To Repeat or Not to Repeat a Course

    Science.gov (United States)

    Armstrong, Michael J.; Biktimirov, Ernest N.

    2013-01-01

    The difficult transition from high school to university means that many students need to repeat (retake) 1 or more of their university courses. The authors examine the performance of students repeating first-year core courses in an undergraduate business program. They used data from university records for 116 students who took a total of 232…

  10. Glycerol metabolism in Lactobacillus collinoides: production of 3-hydroxypropionaldehyde, a precursor of acrolein.

    Science.gov (United States)

    Sauvageot, N; Gouffi, K; Laplace, J M; Auffray, Y

    2000-04-10

    Lactobacillus collinoides is a lactic acid bacterium commonly found in fermenting apple juice. Although this bacterium is not particularly involved in malolactic conversion, the presence of L. collinoides in cider may have serious consequences on the product. L. collinoides is indeed considered to be responsible for the transformation of glycerol to 3-hydroxypropionaldehyde (3-HPA), a precursor of acrolein that spoils the product quality by generating bitter tastes. The purpose of our work was to evaluate the influence of environmental and culture conditions on the conversion of glycerol to 3-HPA in L. collinoides, and to obtain a DNA probe of the gene coding for glycerol dehydratase, the enzyme responsible for this conversion.

  11. Synthesis and characterization of polyesters derived from glycerol and phthalic acid

    Directory of Open Access Journals (Sweden)

    Danilo Hansen Guimarães

    2007-09-01

    Full Text Available The production of polyester via polycondensation between glycerol and phthalic acid using dibutyltin dilaurate is reported. Three glycerol:phthalic acid molar ratio used for the bulk polymerization were: 2:2; 2:3 and 2:4. FTIR confirmed the esterification of glycerol by the acid for all the polymers. DSC indicated no crystallinity, although the XRD plots indicate a very incipient crystallinity for the polymers containing higher amounts of phthalic anhydride. Scanning electron microscopy results indicates high homogeneity for all the polymers prepared.

  12. Anaerobic and aerobic batch cultivations of Saccharomyces cerevisiae mutants impaired in glycerol synthesis

    DEFF Research Database (Denmark)

    Nissen, Torben Lauesgaard; Hamann, Claus Wendelboe; Kielland-Brandt, M. C.;

    2000-01-01

    Glycerol is formed as a by-product in production of ethanol and baker's yeast during fermentation of Saccharomyces cerevisiae under anaerobic and aerobic growth conditions, respectively. One physiological role of glycerol formation by yeast is to reoxidize NADH, formed in synthesis of biomass....... The modest effect of the GPD1 deletion under anaerobic conditions on the maximum specific growth rate and product yields clearly showed that Gdh2p is the important factor in glycerol formation during anaerobic growth. Strain TN6 (gpd1-Delta 1 gpd2-Delta 1) was unable to grow under anaerobic conditions due...

  13. Influence of Glycerol Content on Properties of Wheat Gluten/Hydroxyethyl Cellulose Biocomposites

    Institute of Scientific and Technical Information of China (English)

    SONG Yi-hu; ZHENG Qiang; LIU Cheng

    2008-01-01

    Environmentally friendly biocomposites were prepared by blending wheat gluten(WG) as a matrix,hydroxyethyl cellulose(HEC) as a filler,and glycerol as a plasticizer,followed by thermo-molding of the mixture at 120 ℃ for crosslinking the matrix.Moisture absorption,tensile properties,dynamic mechanical analysis,and dynamic theology were evaluated in relation to the glycerol content.Tensile strength and modulus drop dramatically with increasing glycerol content,which is accompanied by significant depression in the glass transition temperature and improvement in the extensibility of the biocomposites.

  14. A comparative evaluation of plasma glycerol and free fatty acids in patients with ischaemic heart disease

    Directory of Open Access Journals (Sweden)

    Singh V

    1979-01-01

    Full Text Available Plasma glycerol concentration was determined in 158 patients admitted to the hospital with acute chest pain. The patients were retrospectively divided into five groups according to their diagnosis, taking into account the presence or absence of myocardial infarc-tion and complicating arrythmias, The plasma glycerol concentra-tion was significantly higher in the group with complicating arrhythmias, irrespective of whether infarction was present or not. Therefore it is proposed that elevation of plasma glycerol may provide an important clue to determine those myocardial ischaemia cases who may develop cardiac arrythmias at a later stage.

  15. Microbial Conversion of Waste Glycerol from Biodiesel Production into Value-Added Products

    Directory of Open Access Journals (Sweden)

    Hong Liu

    2013-09-01

    Full Text Available Biodiesel has gained a significant amount of attention over the past decade as an environmentally friendly fuel that is capable of being utilized by a conventional diesel engine. However, the biodiesel production process generates glycerol-containing waste streams which have become a disposal issue for biodiesel plants and generated a surplus of glycerol. A value-added opportunity is needed in order to compensate for disposal-associated costs. Microbial conversions from glycerol to valuable chemicals performed by various bacteria, yeast, fungi, and microalgae are discussed in this review paper, as well as the possibility of extending these conversions to microbial electrochemical technologies.

  16. (NH4)2SO4 heterogeneous nucleation and glycerol evaporation of (NH4)2SO4-glycerol system in its dynamic efflorescence process

    Science.gov (United States)

    Cai, Chen; Luan, Ye-mei; Shi, Xiao-min; Zhang, Yun-hong

    2017-02-01

    Using the FTIR-ATR technique, we investigated the heterogeneous nucleation process of aqueous (NH4)2SO4 binary droplets and (NH4)2SO4/glycerol ternary droplets. From the red shift of δ-NH4+ with a linearly declining relative humidity (RH), the ERHs of pure (NH4)2SO4 droplets and mixed (NH4)2SO4/glycerol droplets with different organic-inorganic ratio (OIR) of 1:4, 1:2 and 1:1 ranges from ∼51.9 to ∼34.9%, ∼49.8 to ∼33.0%, ∼48.0 to ∼30.6% and ∼43.7 to ∼25.2%, respectively. From the changing absorbance of δ-NH4+ band, we determined the heterogeneous nucleation rates of crystalline (NH4)2SO4 in the pure and mixed droplets. The interfacial tension between an (NH4)2SO4 critical nucleus and surrounding (NH4)2SO4 solution was determined using classical nucleation theory and experimental data to be 0.031 ± 0.002 J m-2. Evaporation of glycerol in (NH4)2SO4/glycerol ternary droplets are also studied to be restrained by participation of (NH4)2SO4. Determined vapour pressure of glycerol is on the same magnitude with results from previous studies.

  17. Crude glycerol as feedstock for the sustainable production of p-hydroxybenzoate by Pseudomonas putida S12.

    Science.gov (United States)

    Verhoef, Suzanne; Gao, Nisi; Ruijssenaars, Harald J; de Winde, Johannes H

    2014-01-25

    Crude glycerol is a promising renewable feedstock in bioconversion processes for the production of fuels and chemicals. Impurities present in crude glycerol can however, negatively impact the fermentation process. Successful crude glycerol utilization requires robust microbial production hosts that tolerate and preferably, can utilize such impurities. We investigated utilization of crude, unpurified glycerol as a substrate for the production of aromatic compounds by solvent tolerant Pseudomonas putida S12. In high-cell density fed-batch fermentations, P. putida S12 surprisingly performed better on crude glycerol than on purified glycerol. By contrast, growth of Escherichia coli was severely compromised under these high cell density cultivation conditions on crude glycerol. For P. putida S12 the biomass-to-substrate yield, maximum biomass production rate and substrate uptake rate were consistently higher on crude glycerol. Moreover, production of p-hydroxybenzoate by engineered P. putida S12palB5 on crude glycerol showed a 10% yield improvement over production on purified glycerol. P. putida S12 is a favorable host for bioconversion processes utilizing crude glycerol as a substrate. Its intrinsic stress-tolerance properties provide the robustness required for efficient growth and metabolism on this renewable substrate.

  18. Application of intraoperative electrophysiological monitoring in lumbosacral selective posterior rhizotomy for spastic cerebral palsy%选择性腰骶神经后根切断术中肌电监测的应用研究

    Institute of Scientific and Technical Information of China (English)

    徐峰; 曹旭; 赵子义; 张鹏; 许世刚; 徐林

    2009-01-01

    目的 研究在痉挛型脑瘫患者选择性脊神经后根切断术(SPR)中的肌电监测技术与标准.方法 在89例痉挛型脑瘫患者SPR中,采用50 Hz方波电脉冲,分别刺激L3-S1神经后根小束,分别于双侧三角肌、长收肌、股直肌、股二头肌、胫骨前肌和腓肠肌内、外侧头记录自由肌电反应及触发肌电反应,同时观察下肢肌肉痉挛性收缩活动.对肌电反应向对侧、乃至远隔神经支配节段明显扩散的3+级和4+级神经后根小束,及引起下肢或足趾肌肉收缩活动的相对低阈值的神经后根小束进行选择性切断.术后观察下肢肌张力的改善程度,并对下肢感觉、运动及排便功能进行评估.结果 触发肌电反应的出现明显滞后于自由肌电反应,观察自由肌电反应更能及时的判断"异常的"神经小束.89例患儿的372根神经后根被选择性切断,其中324根(83.5%)腰神经后根的出现3+~4+级肌电反应的神经小束被选择性切断;48根(12.9%)神经后根的神经小束根据"相对低阈值"被选择性切断.所有患儿术后下肢肌张力明显降低,未出现明显的下肢感觉、运动及排便功能障碍.结论 SPR中,肌电监测所出现的向对侧和(或)远隔节段扩散的持续的肌肉动作电位反应,是判定"异常"神经后根小束并进行选择性切断的有效并可重复的客观标准.%Objective To evaluate the clinical application of intraoperative electrophysiological monitoring in lumbosacral selective posterior rhizotomy for spastic cerebral palsy. Methods Total 372 dorsal roots of 89 patients underwent selective posterior rhizotomy at a single medical center. The dorsal roots from L3 to S1 were divided into rootlets and stimulated with a 1-second 50 Hz train. Motor responses were recorded by electomyography. Rootlets were assigned according to the extent of abnormal electrophysiological propagation, and grades of 3 + to 4 + were cut. If no electrical response was

  19. 40 CFR 180.1250 - C8, C10, and C12 fatty acid monoesters of glycerol and propylene glycol; exemption from the...

    Science.gov (United States)

    2010-07-01

    ... of glycerol and propylene glycol; exemption from the requirement of a tolerance. 180.1250 Section 180..., C10, and C12 fatty acid monoesters of glycerol and propylene glycol; exemption from the requirement of... monocaprylate, glycerol monocaprate, and glycerol monolaurate) and propylene glycol (propylene...

  20. Nifty Nines and Repeating Decimals

    Science.gov (United States)

    Brown, Scott A.

    2016-01-01

    The traditional technique for converting repeating decimals to common fractions can be found in nearly every algebra textbook that has been published, as well as in many precalculus texts. However, students generally encounter repeating decimal numerals earlier than high school when they study rational numbers in prealgebra classes. Therefore, how…

  1. Nifty Nines and Repeating Decimals

    Science.gov (United States)

    Brown, Scott A.

    2016-01-01

    The traditional technique for converting repeating decimals to common fractions can be found in nearly every algebra textbook that has been published, as well as in many precalculus texts. However, students generally encounter repeating decimal numerals earlier than high school when they study rational numbers in prealgebra classes. Therefore, how…

  2. Effect of glycerol on retention time and electrical properties of polymer bistable memory devices based on glycerol-modified PEDOT:PSS.

    Science.gov (United States)

    Park, Boongik; Lee, Junhwan; Kim, Ohyun

    2012-01-01

    The addition of glycerol to Poly(3,4-ethylenedioxythiophene):Poly(styrene sulfonate) (PEDOT:PSS) films affected the bipolar switching characteristics of nonvolatile polymer memory devices (PMDs). Increasing the glycerol/PEDOT:PSS ratio caused increase in the OFF-current of the PMDs, but did not affect the ON-current levels. This result demonstrates that highly-conductive current paths occur in the ON-state. The write-read-erase-read cycle test was operated > 10(5) times. And, the ON-retention time is largely dependent on the glycerol to PEDOT:PSS ratio and annealing temperature. In addition, AFM analysis on the G-PEDOT:PSS films to see how the surface morphology of G-PEDOT:PSS layer influences the retention time properties was carried out.

  3. All-photonic quantum repeaters

    Science.gov (United States)

    Azuma, Koji; Tamaki, Kiyoshi; Lo, Hoi-Kwong

    2015-01-01

    Quantum communication holds promise for unconditionally secure transmission of secret messages and faithful transfer of unknown quantum states. Photons appear to be the medium of choice for quantum communication. Owing to photon losses, robust quantum communication over long lossy channels requires quantum repeaters. It is widely believed that a necessary and highly demanding requirement for quantum repeaters is the existence of matter quantum memories. Here we show that such a requirement is, in fact, unnecessary by introducing the concept of all-photonic quantum repeaters based on flying qubits. In particular, we present a protocol based on photonic cluster-state machine guns and a loss-tolerant measurement equipped with local high-speed active feedforwards. We show that, with such all-photonic quantum repeaters, the communication efficiency scales polynomially with the channel distance. Our result paves a new route towards quantum repeaters with efficient single-photon sources rather than matter quantum memories. PMID:25873153

  4. Synthesis of high purity monoglycerides from crude glycerol and palm stearin

    Directory of Open Access Journals (Sweden)

    Pakamas Chetpattananondh

    2008-07-01

    Full Text Available The optimum conditions for the glycerolysis of palm stearin and crude glycerol derived from biodiesel process werefound to be a reaction temperature of 200oC with a molar ratio of crude glycerol to palm stearin of 2.5:1, and a reaction timeof 20 minutes. The yield and purity of monoglycerides obtained under these conditions was satisfactory as compared withthe glycerolysis of pure glycerol. To increase the purity of monoglycerides a two-step process, removal of residual glyceroland crystallization, was proposed instead of either vacuum or molecular distillation. Residual glycerol was removed byadding hydrochloric acid followed by washing with hot water. Optimum conditions for crystallization were achieved byusing isooctane as a solvent and a turbine impeller speed of 200 rpm at a crystallization temperature of 35oC. A purity notexceeding 99 percent of monoglycerides was obtained with monopalmitin as the major product.

  5. Synthesis of the Fatty Esters of Solketal and Glycerol-Formal: Biobased Specialty Chemicals.

    Science.gov (United States)

    Perosa, Alvise; Moraschini, Andrea; Selva, Maurizio; Noè, Marco

    2016-01-30

    The caprylic, lauric, palmitic and stearic esters of solketal and glycerol formal were synthesized with high selectivity and in good yields by a solvent-free acid catalyzed procedure. No acetal hydrolysis was observed, notwithstanding the acidic reaction conditions.

  6. Engineering E. coli-E. coli cocultures for production of muconic acid from glycerol

    National Research Council Canada - National Science Library

    Zhang, Haoran; Li, Zhengjun; Pereira, Brian; Stephanopoulos, Gregory

    2015-01-01

    .... In this study, we aim to explore the potential of the E. coli-E. coli coculture system to use a single renewable carbon source, glycerol, for the production of value-added product cis, cis-muconic acid...

  7. A rapid method for an offline glycerol determination during microbial fermentation

    Directory of Open Access Journals (Sweden)

    Jennifer Kuhn

    2015-05-01

    Conclusions: With this rapid assay, glycerol could be detected easily in microbial fermentation broth. It is reliable over a wide concentration range including advantages such as an easy assay set-up, a short assay time and no sample pretreatment.

  8. Glycerol conversion into value added chemicals over bimetallic catalysts in supercritical carbon dioxide

    Science.gov (United States)

    Hidayati, Luthfiana N.; Sudiyarmanto, Adilina, Indri B.

    2017-01-01

    Development of alternative energy from biomass encourage the experiments and production of biodiesel lately. Biodiesel industries widely expand because biodiesel as substitute of fossil fuel recognized as promising renewable energy. Glycerol is a byproduct of biodiesel production, which is resulted 10% wt average every production. Meanwhile, carbon dioxide is a gas that is very abundant amount in the atmosphere. Glycerol and carbon dioxide can be regarded as waste, possibly will produce value-added chemical compounds through chemically treated. In this preliminary study, conversion of glycerol and carbon dioxide using bimetallic catalyst Ni-Sn with various catalyst supports : MgO, γ-Al2O3, and hydrotalcite. Catalysts which have been prepared, then physically characterized by XRD, surface area and porosity analysis, and thermal gravity analysis. Catalytic test performance using supercritical carbon dioxide conditions. Furthermore, the products were analyzed by GC. The final product mostly contained of propylene glycol and glycerol carbonate.

  9. Ultrafine ferromagnetic iron oxide nanoparticles: Facile synthesis by low temperature decomposition of iron glycerolate

    Energy Technology Data Exchange (ETDEWEB)

    Bartůněk, Vilém, E-mail: vilem.bartunek@vscht.cz [Department of Inorganic Chemistry, Faculty of Chemical Technology, University of Chemistry and Technology, Technická 5, 166 28 Prague 6 (Czech Republic); Průcha, David [Department of Inorganic Chemistry, Faculty of Chemical Technology, University of Chemistry and Technology, Technická 5, 166 28 Prague 6 (Czech Republic); Švecová, Marie [Department of Analytical Chemistry, Faculty of Chemical Engineering, University of Chemistry and Technology, Technická 5, 166 28 Prague 6 (Czech Republic); Ulbrich, Pavel [Department of Biochemistry and Microbiology, Faculty of Food and Biochemical Technology, University of Chemistry and Technology, Technická 3, 166 28 Prague 6 (Czech Republic); Huber, Štěpán; Sedmidubský, David; Jankovský, Ondřej [Department of Inorganic Chemistry, Faculty of Chemical Technology, University of Chemistry and Technology, Technická 5, 166 28 Prague 6 (Czech Republic)

    2016-09-01

    We synthesized dark colored ultrafine – sub 10 nm iron oxide nanoparticles by a facile and low temperature process based on thermal decomposition of an affordable precursor – iron glycerolate. Simultaneous thermal analysis (STA) was used to study the thermal behaviour during the decomposition. The iron glycerolate was thoroughly analysed by various methods. The size of the iron nanoparticles was determined from XRD patterns and by transmission electron microscopy (TEM) and their composition has been confirmed by XPS. Magnetic properties of the nanoparticles were studied by vibrating sample magnetometry. The prepared single phase material exhibiting ferromagnetic properties is usable in a wide range of applications and may be suitable even for large scale industrial applications. - Highlights: • Iron glycerolate prepared and characterised. • Iron oxide nanoparticles prepared by thermal decomposition of iron glycerolate. • STA used to study the decomposition. • Products characterised by XRD, XPS, FT-IR, SEM and TEM. • Magnetic behaviour of monophasic samples determined.

  10. Biodiesel biorefinery: opportunities and challenges for microbial production of fuels and chemicals from glycerol waste

    National Research Council Canada - National Science Library

    Almeida, João R M; Fávaro, Léia C L; Quirino, Betania F

    2012-01-01

    ... and coproducts, and reduce industrial waste disposal. In this sense, several alternatives aimed at the use of crude glycerol to produce fuels and chemicals by microbial fermentation have been evaluated...

  11. Steam reforming of crude glycerol with in situ CO(2) sorption.

    Science.gov (United States)

    Dou, Binlin; Rickett, Gavin L; Dupont, Valerie; Williams, Paul T; Chen, Haisheng; Ding, Yulong; Ghadiri, Mojtaba

    2010-04-01

    Steam reforming of the crude glycerol by-product of a biodiesel production plant has been evaluated experimentally at atmospheric pressure, with and without in situ CO(2) sorption, in a continuous flow fixed-bed reactor between 400 degrees C and 700 degrees C. The process outputs were compared to those using pure glycerol. Thermodynamic equilibrium calculations were used to assess the effect on the steam reforming process of the main crude impurities (methanol and four fatty acid methyl esters). The crude glycerol and steam conversions and the H(2) purity reached 100%, 11% and 68%, respectively at 600 degrees C. No CH(4) was found at and above 600 degrees C. Steam reforming of crude glycerol with in situ CO(2) removal is shown to be an effective means of achieving hydrogen purity above 88% in pre-CO(2) breakthrough conditions.

  12. Biotransformation of glycerol to D-glyceric acid by Acetobacter tropicalis.

    Science.gov (United States)

    Habe, Hiroshi; Fukuoka, Tokuma; Kitamoto, Dai; Sakaki, Keiji

    2009-01-01

    Bacterial strains capable of converting glycerol to glyceric acid (GA) were screened among the genera Acetobacter and Gluconacetobacter. Most of the tested Acetobacter and Gluconacetobacter strains could produce 1.8 to 9.3 g/l GA from 10% (v/v) glycerol when intact cells were used as the enzyme source. Acetobacter tropicalis NBRC16470 was the best GA producer and was therefore further investigated. Based on the results of high-performance liquid chromatography analysis and specific rotation, the enantiomeric composition of the produced GA was D-glyceric acid (D-GA). The productivity of D-GA was enhanced with the addition of both 15% (v/v) glycerol and 20 g/l yeast extract. Under these optimized conditions, A. tropicalis NBRC16470 produced 22.7 g/l D-GA from 200 g/l glycerol during 4 days of incubation in a jar fermentor.

  13. AN ALTERNATIVE METHODOLOGY OF DETERMINING FEED SORTING IN TRANSITION DAIRY COWS FED GLYCEROL

    Directory of Open Access Journals (Sweden)

    Eduardo Rodrigues de Carvalho

    2010-12-01

    Full Text Available The objective of this study was to compare the standard methodologywith an alternative method to determine feed sorting in dairy cows during the transition period. Twenty-six Holstein multiparous cows were paired by expected calving date and fed diets containing either glycerol or high moisture corn from -28 through +56 days relative to calving (DRTC. Feed sorting was determined on -16, -9, +9, +15 and +51 DRTC in two different ways. Firstly, it was determinedas the actual intake of each screen of the Penn State Particle Separator (PSPS consumed between 0-4, 4-8, 8-12 and 12-24 hours post feeding, and expressed as a percentage of the predicted intake of that correspondent screen. Secondly, by measuring the particle size distribution of feed consumed between 0-4, 4-8, 8-12 and 12-24 hours post feeding. The total mixed ration (TMR at feeding and at each time post feeding was separated by size using the 3-screen (19, 8, and 1.18 mm Penn State Particle Separator (PSPS to yield long (>19 mm, medium (8 mm, short (1.18 mm, and fine particles (19 mm and reduced (P1.18 mm and fine particles (0.05 the proportion of DM% retained as medium particles (8 mm. Cows fed prepartum glycerol increased (P19 mm according to the standard methodology (77.2 vs. 101.5%, control vs. glycerol and also in the alternative methodology (9.2 vs. 17.8%, control vs. glycerol. Cows fed prepartum glycerol discriminated against (P1.18 mm in the standard methodology (102.6 vs. 94.2%, control vs. glycerol as well as in the alternative methodology (42 vs. 37.3%, control vs. glycerol. There was no response (P>0.05 of diet on feed sorting of fine particles (8 mm according to the standard methodology (108.6 vs. 116.5%, control vs. glycerol, but did not (P>0.05 according to the alternative methodology. Cows fed postpartum glycerol discriminated against (P1.18 mm according to the standard methodology (100.6 vs. 96.6%, control vs. glycerol, but did not (P>0.05 according to the alternative

  14. Metabolic engineering of Escherichia coli to enhance hydrogen production from glycerol.

    Science.gov (United States)

    Tran, Kien Trung; Maeda, Toshinari; Wood, Thomas K

    2014-05-01

    Glycerol is an attractive carbon source for biofuel production since it is cheap and abundant due to the increasing demand for renewable and clean energy sources, which includes production of biodiesel. This research aims to enhance hydrogen production by Escherichia coli from glycerol by manipulating its metabolic pathways via targeted deletions. Since our past strain, which had been engineered for producing hydrogen from glucose, was not suitable for producing hydrogen from glycerol, we rescreened 14 genes related to hydrogen production and glycerol metabolism. We found that 10 single knockouts are beneficial for enhanced hydrogen production from glycerol, namely, frdC (encoding for furmarate reductase), ldhA (lactate dehydrogenase), fdnG (formate dehydrogenase), ppc (phosphoenolpyruvate carboxylase), narG (nitrate reductase), focA (formate transporter), hyaB (the large subunit of hydrogenase 1), aceE (pyruvate dehydrogenase), mgsA (methylglyoxal synthase), and hycA (a regulator of the transcriptional regulator FhlA). On that basis, we created multiple knockout strains via successive P1 transductions. Simultaneous knockouts of frdC, ldhA, fdnG, ppc, narG, mgsA, and hycA created the best strain that produced 5-fold higher hydrogen and had a 5-fold higher hydrogen yield than the parent strain. The engineered strain also reached the theoretical maximum yield of 1 mol H2/mol glycerol after 48 h. Under low partial pressure fermentation, the strain grew over 2-fold faster, indicating faster utilization of glycerol and production of hydrogen. By combining metabolic engineering and low partial pressure fermentation, hydrogen production from glycerol was enhanced significantly.

  15. OPTIMAL FEED STRATEGY FOR FED-BATCH GLYCEROL FERMENTATION DETERMINED BY MAXIMUM PRINCIPLE

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    1 IntroductionGlycerol fed-batch fermentation is attractive tocommercial application since it can control theglucose concentration by changing the feed rate andget a high glycerol yield, therefore it is essential todevelop an optimal glucose feed strategy. For mostof fed-batch fermentation, optimization of feed ratewas based on Pontryagin's maximum principle [if.Since the term of feed rate appears linearly in theHamiltonian, the optimal feed rate profile usuallyconsists of ba,lg-bang intervals and singular ...

  16. Enhanced enzymatic activity of glycerol-3-phosphate dehydrogenase from the cryophilic Saccharomyces kudriavzevii.

    Science.gov (United States)

    Oliveira, Bruno M; Barrio, Eladio; Querol, Amparo; Pérez-Torrado, Roberto

    2014-01-01

    During the evolution of the different species classified within the Saccharomyces genus, each one has adapted to live in different environments. One of the most important parameters that have influenced the evolution of Saccharomyces species is the temperature. Here we have focused on the study of the ability of certain species as Saccharomyces kudriavzevii to grow at low temperatures, in contrast to Saccharomyces cerevisiae. We observed that S. kudriavzevii strains isolated from several regions are able to synthesize higher amounts of glycerol, a molecule that has been shown to accumulate in response to freeze and cold stress. To explain this observation at the molecular level we studied the expression of glycerol biosynthetic pathway genes and we observed a higher expression of GPD1 gene in S. kudriavzevii compared to S. cerevisiae in micro-vinification conditions. We observed higher enzymatic activity of Gpd1p in S. kudriavzevii in response to osmotic and cold stress. Also, we determined that S. kudriavzevii Gpd1p enzyme presents increased catalytic properties that will contribute to increase glycerol production. Finally, we evaluated the glycerol production with S. cerevisiae, S. kudriavzevii or a recombinant Gpd1p variant in the same background and observed that the S. kudriavzevii enzyme produced increased glycerol levels at 12 or 28°C. This suggests that glycerol is increased in S. kudriavzevii mainly due to increased V max of the Gpd1p enzyme. All these differences indicate that S. kudriavzevii has changed the metabolism to promote the branch of the glycolytic pathway involved in glycerol production to adapt to low temperature environments and maintain the NAD(+)/NADH ratio in alcoholic fermentations. This knowledge is industrially relevant due to the potential use, for example, of S. cerevisiae-S. kudriavzevii hybrids in the wine industry where glycerol content is an important quality parameter.

  17. Communication: Contrasting effects of glycerol and DMSO on lipid membrane surface hydration dynamics and forces

    OpenAIRE

    Schrader, Alex M.; Cheng, Chi-Yuan; Israelachvili, Jacob N.; Han, Songi

    2016-01-01

    Glycerol and dimethyl sulfoxide (DMSO) are commonly used cryoprotectants in cellular systems, but due to the challenges of measuring the properties of surface-bound solvent, fundamental questions remain regarding the concentration, interactions, and conformation of these solutes at lipid membrane surfaces. We measured the surface water diffusivity at gel-phase dipalmitoylphosphatidylcholine (DPPC) bilayer surfaces in aqueous solutions containing ≤7.5 mol. % of DMSO or glycerol using Overhause...

  18. Glycerol-based carbon materials for the catalytic wet peroxide oxidation process

    OpenAIRE

    Ribeiro, Rui S.; Silva, Adrián; Pinho, Maria; Figueiredo,José; Faria, Joaquim; Gomes, Helder

    2013-01-01

    It is known that metal-free carbon materials can act as catalysts for the catalytic wet peroxide oxidation (CWPO) process to treat organic pollutants in aqueous solutions [I]. On the other hand, crude glycerol, such as resulting from biodiesel production, is being offered as an abundant and low cost feedstock [2]. In the present work, glycerol-based carbon materials (OBCMs) with distinct properties were produced and tested as catalysts for CWPO, using 2-nitrophenol (2-NP) as a ...

  19. Glycerol: major contributor to the short term protein sparing effect of fat emulsions in normal man.

    Science.gov (United States)

    Brennan, M F; Fitzpatrick, G F; Cohen, K H; Moore, F D

    1975-10-01

    Intravenous fat emulsions have been advocated as acceptable alternatives to hyperosmolar glucose solutions in parenteral nutrition. The ability of a fat emulsion (soy bean oil suspended in glycerol) to produce nitrogen sparing in the absence of nitrogen intake was examined in normal man. The protein conservation obtained by the fat emulsion can be duplicated by the infusion of glycerol alone in the same amount as that available from the fat emulsion.

  20. Getting lipids from glycerol: new perspectives on biotechnological exploitation of Candida freyschussii

    OpenAIRE

    Stefano, Raimondi; Maddalena, Rossi; Alan, Leonardi; Michele, Bianchi; Teresa, Rinaldi; Alberto, Amaretti

    2014-01-01

    Background Microbial lipids represent a valuable alternative feedstock for biodiesel production when oleaginous microbes are cultured with inexpensive substrates in processes exhibiting high yield and productivity. In this perspective, crude glycerol is among the most promising raw materials for lipid production, because it is the costless residual of biodiesel production. Thus, cultivation of oleaginous yeasts in glycerol-based media is attracting great interest and natural biodiversity is i...

  1. Glycerol as a cryoprotectant agent to the entomopathogenic nematodes Heterorhabditis spp. and Steinernema spp.

    Directory of Open Access Journals (Sweden)

    Bruna Aparecida Guide

    2016-10-01

    Full Text Available The difficulty of storage and conservation of entomopathogenic nematodes (ENPs is one of the major obstacles for the expansion of its use in the control of biological pest and in the maintenance of collections of these organisms. The objective of this study was to evaluate cryopreservation as a storage and conservation method for ENPs, using glycerol as cryoprotectant. Infective juveniles (IJs of the species Heterorhabditis amazonensis (RSC 05, H. bacteriophora (HP88, Steinernema feltiae (Sn and S. carpocapse (IBCB-n02 were subjected to the following treatments: (A immersion in glycerol at different concentrations (10, 13 and 15%; (B different exposure times of the isolates to glycerol (24 and 48 hours; and (C two freezing times in liquid nitrogen (LN at –196 ºC (24 and 168 hours. Each treatment was replicated four times, and the design was completely randomized in a factorial 3x2x2 (glycerol concentrations x glycerol exposure time x freezing time in LN. IJs survival was evaluated after each exposure time to glycerol and freezing time in LN. Data were subjected to analysis of variance, and means were compared by the Tukey test. S. feltiae and S. carpocapse survived when exposed to glycerol at 10, 13 and 15% for 24 and 48 hours. After storage in LN for 24 and 168 hours, only S. feltiae survived when exposed to glycerol for 48 hours at concentrations of 10, 13 and 15%, with 40.5; 58.2; and 57.7% survival, respectively. S. feltiae was able to infect Galleria mellonella larvae after freezing. However, for the freezing time of 168 hours, 90% reduction in infectivity was observed.

  2. Aqueous-phase reforming of crude glycerol : effect of impurities on hydrogen production

    NARCIS (Netherlands)

    Boga, Dilek A.; Liu, Fang; Bruijnincx, Pieter C. A.; Weckhuysen, Bert M.

    2016-01-01

    The aqueous-phase reforming (APR) of a crude glycerol that originates from an industrial process and the effect of the individual components of crude glycerol on APR activity have been studied over 1 wt% Pt/Mg-Al) O, 1 wt% Pt/Al2O3, 5 wt% Pt/Al2O3 and 5 wt% Pt/C catalysts at 29 bar and 225 degrees C

  3. Lipid and citric acid production by wild yeasts grown in glycerol.

    Science.gov (United States)

    Souza, Karla Silva Teixeira; Schwan, Rosane Freitas; Dias, Disney Ribeiro

    2014-04-01

    In this study, crude glycerol was used as a carbon source in the cultivation of wild yeasts, aiming for the production of microbial lipids and citric acid. Forty yeasts of different sources were tested concerning their growth in crude and commercial glycerol. Four yeasts (Lidnera saturnus UFLA CES-Y677, Yarrowia lipolytica UFLA CM-Y9.4, Rhodotorula glutinis NCYC 2439, and Cryptococcus curvatus NCYC 476) were then selected owing to their ability to grow in pure (OD600 2.133, 1.633, 2.055, and 2.049, respectively) and crude (OD600 2.354, 1.753, 2.316, and 2.281, respectively) glycerol (10%, 20%, and 30%). Y. lipolytica UFLA CM-Y9.4 was selected for its ability to maintain cell viability in concentrations of 30% of crude glycerol, and high glycerol intake (18.907 g/l). This yeast was submitted to lipid production in 30 g/l of crude glycerol, and therefore obtained 63.4% of microbial lipids. In the fatty acid profile, there was a predominance of stearic (C18:0) and palmitic (C16:0) acids in the concentrations of 87.64% and 74.67%, respectively. We also performed optimization of the parameters for the production of citric acid, which yielded a production of 0.19 g/l of citric acid in optimum conditions (38.4 g/l of crude glycerol, agitation of 184 rpm, and temperature of 30°C). Yarrowia lipolytica UFLA CM-Y9.4 presented good lipid production when in the concentration of 30 g/l of glycerol. These data may be used for production in large quantities for the application of industrial biodiesel.

  4. The study of glycerol-based fermentation and broth downstream by nanofiltration

    Directory of Open Access Journals (Sweden)

    Gryta Marek

    2014-12-01

    Full Text Available In this work, the glycerol fermentation was carried out using Citrobacter freundii bacteria. The influence of glycerol and metabolites concentrations, and the pH changes on the efficiency of 1,3-propanediol production, during batch and fed-batch processes, was presented. The nanofiltration was used for the separation of obtained post-fermentation solutions. The resulted 1,3-PD solutions were significantly desalted, which may facilitate further downstream processes during 1,3-PD production.

  5. [Effects of glycerol on the spectral properties of sodium caseinate].

    Science.gov (United States)

    Li, Yan; Chang, Fen-fen; Gao, Huan-yuan; Cao, Qing; Jin, Li-e

    2015-01-01

    Although the immigration of water molecule, and diffusion and traversing of oxygen can be prevented by the edible film prepared through sodium caseinate, which plays a good protection role for the food, the strong hydrophilicity makes its watertightness and mechanical properties become inferior. Because the toughness and water resistance of SC films can be enhanced by glycerol (G) as an additive, it is necessary to elucidate the interaction between G and SC through the spectral characteristics such as fluorescence spectra, infrared spectra and UV spectra. The results show that the fluorescence intensity of SC decreases due to the addition of G. The binding constant obtained by the double logarithmic regression curve analysis is 1. 127 x 10(3) L . mol-1 and the number of binding sites reaches 1. 161. It indicates that the weak chemical bond is primary between G and SC molecules; From IR the absorption peaks of SC are almost the same before and after adding G. However, there is a certain difference among their absorption intensities. It reveals that the secondary structure of SC is affected, β folding length decreases, α helix, random coil structure, β angle structure increases, and the intermolecular hydrogen bond is strengthened; From UV the peptide bond structure of SC is not changed after the addition of G, but the polymer with larger molecular weight, which is formed by non-covalent bond, makes the peak intensity decrease. The research gives the mode of G and SC from the molecular level.

  6. Mutations and phenotype in isolated glycerol kinase deficiency

    Energy Technology Data Exchange (ETDEWEB)

    Walker, A.P.; Muscatelli, F.; Stafford, A.N.; Monaco, A.P. [Inst. of Molecular Medicine, Oxford (United Kingdom)] [and others

    1996-06-01

    We demonstrate that isolated glycerol kinase (GK) deficiency in three families results from mutation of the Xp21 GK gene. GK mutations were detected in four patients with widely differing phenotypes. Patient 1 had a splice-site mutation causing premature termination. His general health was good despite absent GK activity, indicating that isolated GK deficiency can be silent. Patient 2 had GK deficiency and a severe phenotype involving psychomotor retardation and growth delay, bone dysplasia, and seizures, similar to the severe phenotype of one of the first described cases of GK deficiency. His younger brother, patient 3, also had GK deficiency, but so far his development has been normal. GK exon 17 was deleted in both brothers, implicating additional factors in causation of the severe phenotype of patient 2. Patient 4 had both GK deficiency with mental retardation and a GK missense mutation (D440V). Possible explanations for the phenotypic variation of these four patients include ascertainment bias; metabolic or environmental stress as a precipitating factor in revealing GK-related changes, as has previously been described in juvenile GK deficiency; and interactions with functional polymorphisms in other genes that alter the effect of GK deficiency on normal development. 36 refs., 4 figs., 1 tab.

  7. Thermal Behavior and Thermal Safety of Nitrate Glycerol Ether Cellulose

    Institute of Scientific and Technical Information of China (English)

    XU Si-yu; ZHAO Feng-qi; YI Jian-hua; GAO Hong-xu; SHAO Zi-qiang; HAO Hai-xia; HU Rong-zu; PEI Qing

    2012-01-01

    The thermal behavior,nonisothermal decomposition reaction kinetics and specific heat capacity of nitrate glycerol ether cellulose(NGEC) were determined by thermogravimetric analysis(TGA),differential scanning calorimetry(DSC) and microealorimetry.The apparent activity energy(Ea),reaction mechanism function,quadratic equation of specific heat capacity(Cp) with temperature were obtained.The kinetic parameters of the decomposition reaction are Ea=170.2 kJ/mol and lg(A/s-1)=16.3.The kinetic equation isf(a)=(4/3)(l-a)[-In(l-a)]1/4.The specific heat capacity equation is Cp=1.285-6.276× 10-3T+1.581 × 10-5T2(283 K<T<353 K).With these parameters,the thermal safety properties of NGEC were studied,such as the self-accelerating decomposition temperature(TsADT),critical temperature of thermal explosion(Tb) and adiabatic time-to-explosion(tTlad).The results of the thermal safety evaluation of NGEC are:TSADT=459.6 K,Tb=492.8 K,tTlad=0.8 s.

  8. Acoustic properties in glycerol glass-former: Molecular dynamics simulation

    Science.gov (United States)

    Busselez, Remi; Pezeril, Thomas; Institut des Materiaux et Molecules du Mans Team

    2013-03-01

    Study of high-frequency collective dynamics around TeraHertz region in glass former has been a subject of intense investigations and debates over the past decade. In particular, the presence of the Boson peak characteristic of glassy material and its relation to other glass anomalies. Recently, experiments and simulations have underlined possible relation between Boson peak and transverse acoustic modes in glassy materials. In particular, simulations of simple Lennard Jones glass former have shown a relation between Ioffe-Regel criterion in transverse modes and Boson peak. We present here molecular dynamics simulation on high frequency dynamics of glycerol. In order to study mesoscopic order (0.5-5nm-1), we made use of large simulation box containing 80000 atoms. Analysis of collective longitudinal and transverse acoustic modes shows striking similarities in comparison with simulation of Lennard-Jones particles. In particular, it seems that a connection may exist between Ioffe-Regel criterion for transverse modes and Bose Peak frequency. However,in our case we show that this connection may be related with structural correlation arising from molecular clusters.

  9. Metabolic engineering of Escherichia coli for efficient free fatty acid production from glycerol.

    Science.gov (United States)

    Wu, Hui; Karanjikar, Mukund; San, Ka-Yiu

    2014-09-01

    Crude glycerol, generated as waste by-product in biodiesel production process, has been considered as an important carbon source for converting to value-added bioproducts recently. Free fatty acids (FFAs) can be used as precursors for the production of biofuels or biochemicals. Microbial biosynthesis of FFAs can be achieved by introducing an acyl-acyl carrier protein thioesterase into Escherichia coli. In this study, the effect of metabolic manipulation of FFAs synthesis cycle, host genetic background and cofactor engineering on FFAs production using glycerol as feed stocks was investigated. The highest concentration of FFAs produced by the engineered stain reached 4.82g/L with the yield of 29.55% (g FFAs/g glycerol), about 83% of the maximum theoretical pathway value by the type II fatty acid synthesis pathway. In addition, crude glycerol from biodiesel plant was also used as feedstock in this study. The FFA production was 3.53g/L with a yield of 24.13%. The yield dropped slightly when crude glycerol was used as a carbon source instead of pure glycerol, while it still can reach about 68% of the maximum theoretical pathway yield.

  10. Alternative Glycerol Balance Strategies among Saccharomyces Species in Response to Winemaking Stress

    Science.gov (United States)

    Pérez-Torrado, Roberto; Oliveira, Bruno M.; Zemančíková, Jana; Sychrová, Hana; Querol, Amparo

    2016-01-01

    Production and balance of glycerol is essential for the survival of yeast cells in certain stressful conditions as hyperosmotic or cold shock that occur during industrial processes as winemaking. These stress responses are well-known in S. cerevisiae, however, little is known in other phylogenetically close related Saccharomyces species associated with natural or fermentation environments such as S. uvarum, S. paradoxus or S. kudriavzevii. In this work we have investigated the expression of four genes (GPD1, GPD2, STL1, and FPS1) crucial in the glycerol pool balance in the four species with a biotechnological potential (S. cerevisiae; S. paradoxus; S. uvarum; and S. kudriavzevii), and the ability of strains to grow under osmotic and cold stresses. The results show different pattern and level of expression among the different species, especially for STL1. We also studied the function of Stl1 glycerol symporter in the survival to osmotic changes and cell growth capacity in winemaking environments. These experiments also revealed a different functionality of the glycerol transporters among the different species studied. All these data point to different strategies to handle glycerol accumulation in response to winemaking stresses as hyperosmotic or cold-hyperosmotic stress in the different species, with variable emphasis in the production, influx, or efflux of glycerol. PMID:27064588

  11. Communication: Contrasting effects of glycerol and DMSO on lipid membrane surface hydration dynamics and forces

    Science.gov (United States)

    Schrader, Alex M.; Cheng, Chi-Yuan; Israelachvili, Jacob N.; Han, Songi

    2016-07-01

    Glycerol and dimethyl sulfoxide (DMSO) are commonly used cryoprotectants in cellular systems, but due to the challenges of measuring the properties of surface-bound solvent, fundamental questions remain regarding the concentration, interactions, and conformation of these solutes at lipid membrane surfaces. We measured the surface water diffusivity at gel-phase dipalmitoylphosphatidylcholine (DPPC) bilayer surfaces in aqueous solutions containing ≤7.5 mol. % of DMSO or glycerol using Overhauser dynamic nuclear polarization. We found that glycerol similarly affects the diffusivity of water near the bilayer surface and that in the bulk solution (within 20%), while DMSO substantially increases the diffusivity of surface water relative to bulk water. We compare these measurements of water dynamics with those of equilibrium forces between DPPC bilayers in the same solvent mixtures. DMSO greatly decreases the range and magnitude of the repulsive forces between the bilayers, whereas glycerol increases it. We propose that the differences in hydrogen bonding capability of the two solutes leads DMSO to dehydrate the lipid head groups, while glycerol affects surface hydration only as much as it affects the bulk water properties. The results suggest that the mechanism of the two most common cryoprotectants must be fundamentally different: in the case of DMSO by decoupling the solvent from the lipid surface, and in the case of glycerol by altering the hydrogen bond structure and intermolecular cohesion of the global solvent, as manifested by increased solvent viscosity.

  12. Fermentation of residual glycerol by Clostridium acetobutylicum ATCC 824 in pure and mixed cultures.

    Science.gov (United States)

    Dams, Rosemeri I; Guilherme, Alexandre A; Vale, Maria S; Nunes, Vanja F; Leitão, Renato C; Santaella, Sandra T

    2016-12-01

    The aim of this research was to estimate the production of hydrogen, organic acids and alcohols by the strain of Clostridium acetobutylicum ATCC 824 using residual glycerol as a carbon source. The experiments were carried out in pure and mixed cultures in batch experiments. Three different sources of inocula for mixed culture were used. Ruminal liquid from goats and sludge collected from two upflow anaerobic sludge blanket reactors treating municipal wastewater and brewery effluent were tested for hydrogen, organic acids and alcohols production with or without C. acetobutylicum ATCC 824. The main detected end-products from the glycerol fermentation were hydrogen, organic acids (acetic, propionic, butyric and caproic) and alcohol (ethanol and 1,3-propanediol - 1,3PD). High hydrogen (0.44 mol H2/mol glycerol consumed) and 1,3PD (0.32 mol 1,3PD/mol glycerol consumed) yields were obtained when the strain C. acetobutylicum ATCC 824 was bioaugmented into the sludge from municipal wastewater using 5 g/L of glycerol. Significant concentrations of n-caproic acid were detected in the ruminal liquid when amended with C. acetobutylicum ATCC 824. The results suggest that glycerol can be used for the generation of H2, 1,3PD and n-caproic acid using C. acetobutylicum ATCC 824 as agent in pure or mixed cultures.

  13. Consolidating biofuel platforms through the fermentative bioconversion of crude glycerol to butanol.

    Science.gov (United States)

    Johnson, Erin; Sarchami, Tahereh; Kießlich, Sascha; Munch, Garret; Rehmann, Lars

    2016-06-01

    Economic realities for the rising industrial biofuel production have changed substantially during the low oil price period starting in the mid 2010's. Increased competition requires the sector to increase productivity through the reduction of low-value by-products and full utilization of all value and energy stored in their respective feedstock. Biodiesel is produced commercially from substrates such as animal fat and vegetable oil, generating approximately 10 wt% crude glycerol as its main, currently underutilized, by-product. This crude glycerol is contaminated with catalyst, soap, free fatty acids, glycerides and methyl esters; hence only a small fraction enters the existing glycerol markets, while the purification costs for the majority of crude glycerol are simply too high. However, this presents a unique opportunity to generate additional value. One technical possibility is to use crude glycerol as a carbon source for butanol production, a compound of higher value and energy, a potential additive for gasoline and diesel fuels and bulk chemical commodity. Conversion facilities could be co-located with biodiesel plants, utilizing established infrastructure and adding significant value and productivity to the existing biodiesel industry. This review focuses on the current activities geared towards the bioconversion of crude glycerol to butanol.

  14. Swelling and tensile properties of starch glycerol system with various crosslinking agents

    Science.gov (United States)

    Mohamed, R.; Mohd, N.; Nurazzi, N.; Siti Aisyah, M. I.; Fauzi, F. Mohd

    2017-07-01

    Brittle properties of starch had been overcome by the modification process. In this work, sago starch is being modified with variable amount of plasticiser, namely glycerol at 20 and 40% and crosslinking agent had been added to the system. The film of the modification and characterizations of the starch glycerol system with various crosslinking systems were produced by casting method. The film properties of the starch glycerol system were then characterized by tensile strength (mechanical properties) and swelling (physical properties). The modification of the starch glycerol had improved that system by increasing the tensile strength, modulus however lowering its elongation. The increasing in percentage of the water absorption and also swelling are due to the intrinsic hydroxyl groups presence from the starch and glycerol itself that can attract more water to the system. Upon crosslinking, films casted with chemicals namely, glyoxal, malonic acid, borax, PEG were characterised. It was found that, all the film of sago starch crosslinked and undergoing easy film formation. From this modification, borax and malonic acid crosslinking agent had been determined as the best crosslinking agent to the starch glycerol system.

  15. Integral process of obtaining glycerol as a by-product of biodiesel production from castor oil

    Directory of Open Access Journals (Sweden)

    Leonel Romero

    2012-12-01

    Full Text Available The biodiesel is obtained from about 10 years ago in Europe, and now that it has taken hold as fuel for diesel engines, it is expected a clear increase in the production of this class of fuels in a the near future. The biodiesel is derived from the transesterification reaction of castor oil with methanol, which is the main by-product the glycerol with an approximate content of 10%. Besides catalyst residuals, soaps, methanol traces, mono and diglycerides in small percentages are presented. This study proposes the separation, purification and characterization of the glycerol obtained from the transesterificación reaction of the castor oil, in order to be able to market it in the national or international market, so that it fulfills the standards of quality, which means getting a pure glycerol and the appropriate physico-chemical characteristics and techniques. The glycerin-methyl esters separation is carried out by decantation being obtained a percentage of around 70% glycerol. This percentage is subsequently increased through the purification process, using hydrochloric acid. Glycerol characterization was carried out by physicochemical and organoleptic tests. The purification process allowed us to obtain a glycerol with a percentage of purity close to 98%. It was also tested by comparison with theoretical data that remnants influenced in the physiochemical properties

  16. Gas-phase dehydration of glycerol over commercial Pt/γ-Al2O3 catalysts

    Institute of Scientific and Technical Information of China (English)

    Sergey Danov; Anton Esipovich; Artem Belousov; Anton Rogozhin

    2015-01-01

    Gas-phase dehydration of glycerol to produce acrolein was investigated over commercial catalysts based onγ-Al2O3, viz. A-64, A-56, I-62, AP-10, AP-56, AP-64 and KR-104. To understand the effect of Cl−anions, HCl-impregnated sup-ports have been investigated in the dehydration reaction of glycerol at 375 °C. For comparison, various H-zeolites were also examined. It was found that the glycerol conversion over the solid acid catalysts was strongly dependent on their acidity and surface area. And the relationship between the catalytic activity and the acidity of the catalysts was discussed. The outstanding properties of Pt/γ-Al2O3 catalyst systems for the dehydration of glycerol were revealed. Pt/γ-Al2O3 catalyst (AP-64) showed the highest catalytic activity after 50 h of reaction with an acrolein selectivity of 65%at a conversion of glycerol of 90%. Based on these results, catalysts based onγ-Al2O3 appear to be most promising for gas phase dehydration of glycerol.

  17. Chronic metabolic responses of postpartal dairy cows to subcutaneous glucagon injections, oral glycerol, or both.

    Science.gov (United States)

    Osman, M A; Allen, P S; Bobe, G; Coetzee, J F; Abuzaid, A; Koehler, K; Beitz, D C

    2010-08-01

    We examined the long-term effects of daily subcutaneous injections of 15 mg of glucagon during the first 14 d postpartum with or without coadministration of 400 mL of pure glycerol orally on blood metabolites and hormones and liver composition of Holstein dairy cows during early lactation. Fourteen multiparous cows with body condition score of >or=3.5 points (1-5 point scale) were assigned randomly to one of 4 treatment groups-saline, glucagon, glycerol, or glucagon plus glycerol. Fatty liver syndrome was induced by feeding cows a dry-cow ration supplemented with 6 kg of cracked corn daily during the last 6 wk of the dry period. Compared with saline treatment (n=3), coadministration of glucagon and glycerol (n=4) increased plasma glucose and insulin and decreased plasma nonesterified fatty acid concentrations in both treatment weeks, whereas glucagon alone (n=3) produced similar changes plus a decrease in plasma beta-hydroxybutyrate in the second week only. No significant changes were observed for the glycerol alone treatment (n=4). We conclude that a single daily dose of glycerol for the first 14 d postpartum may potentiate the action of glucagon in the first treatment days to alleviate some symptoms of fatty liver syndrome, such as the increase in plasma nonesterified fatty acids and the decrease in plasma glucose and insulin, in Holstein dairy cows after parturition.

  18. Identification of positive regulators of the yeast fps1 glycerol channel.

    Directory of Open Access Journals (Sweden)

    Sara E Beese

    2009-11-01

    Full Text Available The yeast Fps1 protein is an aquaglyceroporin that functions as the major facilitator of glycerol transport in response to changes in extracellular osmolarity. Although the High Osmolarity Glycerol pathway is thought to have a function in at least basal control of Fps1 activity, its mode of regulation is not understood. We describe the identification of a pair of positive regulators of the Fps1 glycerol channel, Rgc1 (Ypr115w and Rgc2 (Ask10. An rgc1/2Delta mutant experiences cell wall stress that results from osmotic pressure associated with hyper-accumulation of glycerol. Accumulation of glycerol in the rgc1/2Delta mutant results from a defect in Fps1 activity as evidenced by suppression of the defect through Fps1 overexpression, failure to release glycerol upon hypo-osmotic shock, and resistance to arsenite, a toxic metalloid that enters the cell through Fps1. Regulation of Fps1 by Rgc1/2 appears to be indirect; however, evidence is presented supporting the view that Rgc1/2 regulate Fps1 channel activity, rather than its expression, folding, or localization. Rgc2 was phosphorylated in response to stresses that lead to regulation of Fps1. This stress-induced phosphorylation was partially dependent on the Hog1 MAPK. Hog1 was also required for basal phosphorylation of Rgc2, suggesting a mechanism by which Hog1 may regulate Fps1 indirectly.

  19. Microbial utilization of crude glycerol for the production of value-added products.

    Science.gov (United States)

    Dobson, Rosemary; Gray, Vincent; Rumbold, Karl

    2012-02-01

    Energy fuels for transportation and electricity generation are mainly derived from finite and declining reserves of fossil hydrocarbons. Fossil hydrocarbons are also used to produce a wide range of organic carbon-based chemical products. The current global dependency on fossil hydrocarbons will not be environmentally or economically sustainable in the long term. Given the future pessimistic prospects regarding the complete dependency on fossil fuels, political and economic incentives to develop carbon neutral and sustainable alternatives to fossil fuels have been increasing throughout the world. For example, interest in biodiesel has undergone a revival in recent times. However, the disposal of crude glycerol contaminated with methanol, salts, and free fatty acids as a by-product of biodiesel production presents an environmental and economic challenge. Although pure glycerol can be utilized in the cosmetics, tobacco, pharmaceutical, and food industries (among others), the industrial purification of crude glycerol is not economically viable. However, crude glycerol could be used as an organic carbon substrate for the production of high-value chemicals such as 1,3-propanediol, organic acids, or polyols. Microorganisms have been employed to produce such high-value chemicals and the objective of this article is to provide an overview of studies on the utilization of crude glycerol by microorganisms for the production of economically valuable products. Glycerol as a by-product of biodiesel production could be used a feedstock for the manufacture of many products that are currently produced by the petroleum-based chemical industry.

  20. Contribution of glycerol on production of poly(gamma-Glutamic Acid) in Bacillus subtilis NX-2.

    Science.gov (United States)

    Wu, Qun; Xu, Hong; Liang, Jinfeng; Yao, Jun

    2010-01-01

    Glycerol would stimulate the production of poly(gamma-glutamic acid) (gamma-PGA) and decrease its molecular weight in Bacillus subtilis NX-2. When 20 g/l glycerol was added in the medium, the yield of gamma-PGA increased from 26.7 +/- 1.0 to 31.7 +/- 1.3 g/l, and molecular weight of gamma-PGA decreased from 2.43 +/- 0.07 x 10(6) to 1.86 +/- 0.06 x 10(6) Da. In addition, it was found that the decrease of gamma-PGA chain length by glycerol would lead to the decrease of broth viscosity during the fermentation and enhanced the uptake of substrates, which could not only improve cell growth but also stimulate gamma-PGA production. Moreover, it was also found that glycerol could effectively regulate molecular weight between 2.43 +/- 0.07 x 10(6) and 1.42 +/- 0.05 x 10(6) Da with the concentration ranging from 0 to 60 g/l. This was the first time to discover such contribution of glycerol on gamma-PGA production in Bacillus genus. And the effects of glycerol on molecular weight of gamma-PGA would be developed to be an approach for the regulation of microbial gamma-PGA chain length, which is of practical importance for future commercial development of this polymer.

  1. Role of CgHOG1 in Stress Responses and Glycerol Overproduction of Candida glycerinogenes.

    Science.gov (United States)

    Ji, Hao; Zhuge, Bin; Zong, Hong; Lu, Xinyao; Fang, Huiying; Zhuge, Jian

    2016-12-01

    Candida glycerinogenes, the glycerol producer with excellent multi-stress tolerances, is considered to be a potential biotechnological host used in the production of glycerol and its derivatives under extreme fermentation conditions. In this study, to evaluate the multiple roles of mitogen-activated protein kinase CgHOG1, we constructed a gene disruption system in the diploid C. glycerinogenes to obtain CgHOG1 null mutant. Pseudohyphae generation of the CgHOG1 mutant under non-inducing condition indicated a repressor role in morphological transitions. Disruption of CgHOG1 resulted in increased sensitivities to osmotic, acetic acid, and oxidative stress but not involved in thermotolerance. In the CgHOG1 mutant, NaCl shock failed to stimulate the accumulation of intracellular glycerol and was fatal. In addition, the CgHOG1 mutant displayed a significant prolonged growth lag phase in YPD medium with no decrease in glycerol production, whereas the mutant cannot grow under hyperosmotic condition with no detectable glycerol in broth. These results suggested that CgHOG1 plays important roles in morphogenesis and multi-stress tolerance. The growth and glycerol overproduction under osmotic stress are heavily dependent on CgHOG1 kinase.

  2. High hydrogen production from glycerol or glucose by electrohydrogenesis using microbial electrolysis cells

    KAUST Repository

    Selembo, Priscilla A.

    2009-07-01

    The use of glycerol for hydrogen gas production was examined via electrohydrogenesis using microbial electrolysis cells (MECs). A hydrogen yield of 3.9 mol-H2/mol was obtained using glycerol, which is higher than that possible by fermentation, at relatively high rates of 2.0 ± 0.4 m3/m3 d (Eap = 0.9 V). Under the same conditions, hydrogen was produced from glucose at a yield of 7.2 mol-H2/mol and a rate of 1.9 ± 0.3 m3/m3 d. Glycerol was completely removed within 6 h, with 56% of the electrons in intermediates (primarily 1,3-propanediol), with the balance converted to current, intracellular storage products or biomass. Glucose was removed within 5 h, but intermediates (mainly propionate) accounted for only 19% of the electrons. Hydrogen was also produced using the glycerol byproduct of biodiesel fuel production at a rate of 0.41 ± 0.1 m3/m3 d. These results demonstrate that electrohydrogenesis is an effective method for producing hydrogen from either pure glycerol or glycerol byproducts of biodiesel fuel production. © 2009 International Association for Hydrogen Energy.

  3. Biohydrogen production by dark fermentation of glycerol using Enterobacter and Citrobacter Sp.

    Science.gov (United States)

    Maru, Biniam T; Constanti, Magda; Stchigel, Alberto M; Medina, Francesc; Sueiras, Jesus E

    2013-01-01

    Glycerol is an attractive substrate for biohydrogen production because, in theory, it can produce 3 mol of hydrogen per mol of glycerol. Moreover, glycerol is produced in substantial amounts as a byproduct of producing biodiesel, the demand for which has increased in recent years. Therefore, hydrogen production from glycerol was studied by dark fermentation using three strains of bacteria: namely, Enterobacter spH1, Enterobacter spH2, and Citrobacter freundii H3 and a mixture thereof (1:1:1). It was found that, when an initial concentration of 20 g/L of glycerol was used, all three strains and their mixture produced substantial amounts of hydrogen ranging from 2400 to 3500 mL/L, being highest for C. freundii H3 (3547 mL/L) and Enterobacter spH1 (3506 mL/L). The main nongaseous fermentation products were ethanol and acetate, albeit in different ratios. For Enterobacter spH1, Enterobacter spH2, C. freundii H3, and the mixture (1:1:1), the ethanol yields (in mol EtOH/mol glycerol consumed) were 0.96, 0.67, 0.31, and 0.66, respectively. Compared to the individual strains, the mixture (1:1:1) did not show a significantly higher hydrogen level, indicating that there was no synergistic effect. Enterobacter spH1 was selected for further investigation because of its higher yield of hydrogen and ethanol.

  4. Glycerol assimilation and production of 1,3-propanediol by Citrobacter amalonaticus Y19.

    Science.gov (United States)

    Ainala, Satish Kumar; Ashok, Somasundar; Ko, Yeounjoo; Park, Sunghoon

    2013-06-01

    Citrobacter amalonaticus Y19 (Y19) was isolated because of its ability for carbon monoxide-dependent hydrogen production (water-gas shift reaction). This paper reports the assimilation of glycerol and the production of 1,3-propanediol (1,3-PDO) by Y19. Genome sequencing revealed that Y19 contained the genes for the utilization of glycerol and 1,2-propanediol (pdu operon) along with those for the synthesis of coenzyme B12 (cob operon). On the other hand, it did not possess the genes for the fermentative metabolism of glycerol of Klebsiella pneumoniae, which consists of both the oxidative (dhaD and dhaK) and reductive (dhaB and dhaT) pathways. In shake-flask cultivation under aerobic conditions, Y19 could grow well with glycerol as the sole carbon source and produced 1,3-PDO. The level of 1,3-PDO production was improved when vitamin B12 was added to the culture medium under aerobic conditions. Under anaerobic conditions, cell growth and 1,3-PDO production on glycerol was also possible, but only when an exogenous electron acceptor, such as nitrate or fumarate, was added. This is the first report of the glycerol metabolism and 1,3-PDO production by C. amalonaticus Y19.

  5. Glycerol production by fermenting yeast cells is essential for optimal bread dough fermentation.

    Science.gov (United States)

    Aslankoohi, Elham; Rezaei, Mohammad Naser; Vervoort, Yannick; Courtin, Christophe M; Verstrepen, Kevin J

    2015-01-01

    Glycerol is the main compatible solute in yeast Saccharomyces cerevisiae. When faced with osmotic stress, for example during semi-solid state bread dough fermentation, yeast cells produce and accumulate glycerol in order to prevent dehydration by balancing the intracellular osmolarity with that of the environment. However, increased glycerol production also results in decreased CO2 production, which may reduce dough leavening. We investigated the effect of yeast glycerol production level on bread dough fermentation capacity of a commercial bakery strain and a laboratory strain. We find that Δgpd1 mutants that show decreased glycerol production show impaired dough fermentation. In contrast, overexpression of GPD1 in the laboratory strain results in increased fermentation rates in high-sugar dough and improved gas retention in the fermenting bread dough. Together, our results reveal the crucial role of glycerol production level by fermenting yeast cells in dough fermentation efficiency as well as gas retention in dough, thereby opening up new routes for the selection of improved commercial bakery yeasts.

  6. Effect of the initial glycerol concentration in the medium on the xanthan biosynthesis

    Directory of Open Access Journals (Sweden)

    Rončević Zorana Z.

    2014-01-01

    Full Text Available This study is concerned with the effect of different initial glycerol concentrations in the medium on xanthan production by Xanthomonas campestris ATCC 13951. Xanthan biosynthesis was carried out in batch mode under aerobic conditions at a temperature of 30oC and agitation rate of 150 rpm for 7 days. The process efficiency was estimated based on the values of raw xanthan yield, average molecular weight of the polymer and residual content of glycerol, total nitrogen and phosphorus. Based on these results, the initial concentration of glycerol as a carbon source in the production medium was suggested. In the applied experimental conditions, high raw xanthan yield (12.15 g/l of good quality (Mw = 2.86•105 g/mol and the lowest amount of residual nutrients (glycerol 2.75 g/l, nitrogen 0.46 g/l and phosphorus 0.67 g/l was achieved in the medium with the initial glycerol content of 20 g/l. The obtained results are the basis for optimization of xanthan production on glycerol containing media in order to increase the product yield and quality.

  7. Production of biohydrogen from crude glycerol in an upflow column bioreactor.

    Science.gov (United States)

    Dounavis, Athanasios S; Ntaikou, Ioanna; Lyberatos, Gerasimos

    2015-12-01

    A continuous attached growth process for the production of biohydrogen from crude glycerol was developed. The process consisted of an anaerobic up-flow column bioreactor (UFCB), packed with cylindrical ceramic beads, which constituted the support matrix for the attachment of bacterial cells. The effect of crude glycerol concentration, pH and hydraulic retention time on glycerol conversion, hydrogen yield and metabolite distribution was investigated. It was shown that the most critical parameter for the efficient bioconversion was the pH of the influent, whereas the hydrogen yield increased with an increase in feed glycerol concentration and a decrease in the hydraulic retention time. The main soluble metabolite detected was 1,3-propanediol in all cases, followed by butyric and hexanoic acids. The latter is reported to be produced from glycerol for the first time. Acidification of the waste reached 38.5%, and the maximum H2 productivity was 107.3 ± 0.7 L/kg waste glycerol at optimal conditions.

  8. The citric acid production from raw glycerol by Yarrowia lipolytica yeast and its regulation.

    Science.gov (United States)

    Morgunov, Igor G; Kamzolova, Svetlana V; Lunina, Julia N

    2013-08-01

    The optimal cultivation conditions ensuring the maximal rate of citric acid (CA) biosynthesis by glycerol-grown mutant Yarrowia lipolytica NG40/UV7 were found to be as follows: growth limitation by inorganic nutrients (nitrogen, phosphorus, or sulfur), 28 °C, pH 5.0, dissolved oxygen concentration (pO₂) of 50 % (of air saturation), and pulsed addition of glycerol from 20 to 80 g L⁻¹ depending on the rate of medium titration. Under optimal conditions of fed-batch cultivation, in the medium with pure glycerol, strain Y. lipolytica NG40/UV7 produced 115 g L⁻¹ of CA with the mass yield coefficient of 0.64 g g⁻¹ and isocitric acid (ICA) amounted to 4.6 g L⁻¹; in the medium with raw glycerol, CA production was 112 g L⁻¹ with the mass yield coefficient of 0.90 g g⁻¹ and ICA amounted to 5.3 g L⁻¹. Based on the activities of enzymes involved in the initial stages of raw glycerol assimilation, the tricarboxylic acid cycle and the glyoxylate cycle, the mechanism of increased CA yield from glycerol-containing substrates in Y. lipolytica yeast was explained.

  9. Wide distribution of autochthonous branched glycerol dialkyl glycerol tetraethers (bGDGTs) in U.S. Great Basin hot springs.

    Science.gov (United States)

    Hedlund, Brian P; Paraiso, Julienne J; Williams, Amanda J; Huang, Qiuyuan; Wei, Yuli; Dijkstra, Paul; Hungate, Bruce A; Dong, Hailiang; Zhang, Chuanlun L

    2013-01-01

    Branched glycerol dialkyl glycerol tetraethers (bGDGTs) are membrane-spanning lipids that likely stabilize membranes of some bacteria. Although bGDGTs have been reported previously in certain geothermal environments, it has been suggested that they may derive from surrounding soils since bGDGTs are known to be produced by soil bacteria. To test the hypothesis that bGDGTs can be produced by thermophiles in geothermal environments, we examined the distribution and abundance of bGDGTs, along with extensive geochemical data, in 40 sediment and mat samples collected from geothermal systems in the U.S. Great Basin (temperature: 31-95°C; pH: 6.8-10.7). bGDGTs were found in 38 out of 40 samples at concentrations up to 824 ng/g sample dry mass and comprised up to 99.5% of total GDGTs (branched plus isoprenoidal). The wide distribution of bGDGTs in hot springs, strong correlation between core and polar lipid abundances, distinctness of bGDGT profiles compared to nearby soils, and higher concentration of bGDGTs in hot springs compared to nearby soils provided evidence of in situ production, particularly for the minimally methylated bGDGTs I, Ib, and Ic. Polar bGDGTs were found almost exclusively in samples ≤70°C and the absolute abundance of polar bGDGTs correlated negatively with properties of chemically reduced, high temperature spring sources (temperature, H2S/HS(-)) and positively with properties of oxygenated, low temperature sites (O2, NO(-) 3). Two-way cluster analysis and nonmetric multidimensional scaling based on relative abundance of polar bGDGTs supported these relationships and showed a negative relationship between the degree of methylation and temperature, suggesting a higher abundance for minimally methylated bGDGTs at high temperature. This study presents evidence of the widespread production of bGDGTs in mats and sediments of natural geothermal springs in the U.S. Great Basin, especially in oxygenated, low-temperature sites (≤70°C).

  10. Wide distribution of autochthonous branched glycerol dialkyl glycerol tetraethers (bGDGTs in U.S. Great Basin hot springs

    Directory of Open Access Journals (Sweden)

    Brian P. Hedlund

    2013-08-01

    Full Text Available Branched glycerol dialkyl glycerol tetraethers (bGDGTs are membrane-spanning lipids that likely stabilize membranes of some bacteria. Although bGDGTs have been reported previously in certain geothermal environments, it has been suggested that they may derive from surrounding soils since bGDGTs are known to be produced by soil bacteria. To test the hypothesis that bGDGTs can be produced by thermophiles in geothermal environments, we examined the distribution and abundance of bGDGTs, along with extensive geochemical data, in 40 sediment and mat samples collected from geothermal systems in the U.S. Great Basin (temperature: 31-95°C; pH: 6.8-10.7. bGDGTs were found in 38 out of 40 samples at concentrations up to 824 ng/g sample dry mass and comprised up to 99.5% of total GDGTs (branched plus isoprenoidal. The wide distribution of bGDGTs in hot springs, strong correlation between core and polar lipid abundances, distinctness of bGDGT profiles compared to nearby soils, and higher concentration of bGDGTs in hot springs compared to nearby soils provided evidence of in situ production, particularly for the minimally methylated bGDGTs I, Ib, and Ic. Polar bGDGTs were found almost exclusively in samples ≤ 70°C and the absolute abundance of polar bGDGTs correlated negatively with properties of chemically reduced, high temperature spring sources (temperature, H2S/HS- and positively with properties of oxygenated, low temperature sites (O2, NO3-. Two-way cluster analysis and nonmetric multidimensional scaling based on relative abundance of polar bGDGTs supported these relationships and showed a negative relationship between the degree of methylation and temperature, suggesting a higher abundance for minimally methylated bGDGTs at high temperature. This study presents evidence of the widespread production of bGDGTs in mats and sediments of natural geothermal springs in the U.S. Great Basin, especially in oxygenated, low-temperature sites (≤ 70°C.

  11. The effect of glycerol from biodiesel production waste as a plasticizer on physical character edible film of chitosan

    Science.gov (United States)

    Rosyid, Fajar Abdul; Triastuti, Rr. Juni; Andriyono, Sapto

    2017-02-01

    Chitosan edible film is a thin layer of clear packaging made from chitosan edible and biodegradable. Edible chitosan films are stiffer and less elastic, so it should be added plasticizer glycerol. One source of glycerol is inexpensive and easily obtained is crude glycerol from biodiesel production. The purpose of this study was to determine the effect of various concentrations of crude glycerol plasticizer on the physical characteristics of chitosan edible film and determine the best concentration of crude glycerol plasticizer. This study used a completely randomized design (CRD) with five treatments and four replications. The Edible film using the g chitosan and some plasticizers concentration of crude glycerol (0.2, 0.4, 0.8, and 1 mL) and a control treatment that used 0.4 mL of pure glycerol was made. The results showed that the use of crude glycerol plasticizer had effect to the physical character of chitosan edible film. Increasing concentrations of crude glycerol plasticizer exhibits the lowers value of the thickness and tensile strength, however, can increase the value of percent elongation. The best concentration of this research is the treatment of B (0.2 ml crude glycerol) which resulted in 0.55 mm thickness, the tensile strength of 95.38 kgf/cm2 and a percent elongation of 2.13%.

  12. Individualized surgical treatment of cerebral palsy with hip adduction deformity after selective posterior rhizotomy%脑瘫SPR术后遗留髋内收畸形的个体化手术治疗

    Institute of Scientific and Technical Information of China (English)

    王逢贤; 曹旭; 俞兴; 曲弋; 穆晓红; 徐林

    2014-01-01

    Objective To evaluate the surgical options and clinical effects of treatment of spastic cerebral palsy with hip adduction deformity after selective posterior rhizotomy (SPR). Methods From August 2008 to August 2012, 126 patients with hip adduction deformity who had performed SPR for spastic cerebral palsy were treated in Dongzhimen Hospital affiliated to Beijing University of Chinese Medicine. According to the range of muscle contracture and the degree of deformity, different surgical methods were chosen including tenotomy of long adductor muscle, short adductor muscle, gracilis, iliopsoas, as well as transection of anterior branch of obturator nerve etc. Results All cases were followed up with the average time of 22 months (14-38 months). Postoperative hip adduction deformity improved significantly, among them, the angle of hip abduction more than 30° was in 118 cases, while 20° to 30° in 8 cases, with the rate of remission 100% (126/126), and the satisfaction rate 93.6% (118/126). No limb sensory disturbance, hip abduction or external rotation deformity were found after the surgery. Conclusion For cerebral palsy patients with hip adduction deformity after SPR, individualized surgical treatment including muscle tenotomy and transection of anterior branch of obturator nerve could bring into satisfactory clinical efficacy according to different patients' individual situations.%目的:评价痉挛型脑瘫患者腰骶段选择性脊神经后根切断术(SPR)后遗留髋内收畸形的手术方案选择及临床疗效。方法回顾性分析2008年8月至2012年8月北京中医药大学东直门医院收治的126例脑瘫SPR术后遗留髋内收畸形患者的临床资料,根据肌肉挛缩的范围和畸形程度采取不同的手术方式,包括长收肌、短收肌、股薄肌、髂腰肌、闭孔神经前支切断术等。观察患者术后髋外展角度及畸形矫正情况。结果126例患者随访14~38个月(平均22个月)。术后髋内

  13. Analysis of repeated measures data

    CERN Document Server

    Islam, M Ataharul

    2017-01-01

    This book presents a broad range of statistical techniques to address emerging needs in the field of repeated measures. It also provides a comprehensive overview of extensions of generalized linear models for the bivariate exponential family of distributions, which represent a new development in analysing repeated measures data. The demand for statistical models for correlated outcomes has grown rapidly recently, mainly due to presence of two types of underlying associations: associations between outcomes, and associations between explanatory variables and outcomes. The book systematically addresses key problems arising in the modelling of repeated measures data, bearing in mind those factors that play a major role in estimating the underlying relationships between covariates and outcome variables for correlated outcome data. In addition, it presents new approaches to addressing current challenges in the field of repeated measures and models based on conditional and joint probabilities. Markov models of first...

  14. Erythritol production by Moniliella megachiliensis using nonrefined glycerol waste as carbon source.

    Science.gov (United States)

    Kobayashi, Y; Iwata, H; Mizushima, D; Ogihara, J; Kasumi, T

    2015-05-01

    The number of naphtha plants is being reduced due to a worldwide shift in energy sources. Consequently, a shortage of chemical materials heavily dependent on naphtha-oil, especially C4 compounds such as butene and butane-diol, is an urgent issue in chemical manufacturing. Erythritol is a rare C4 compound produced by fermentation processes using glucose as the carbon source. Since erythritol is considerably more expensive than hydrocarbons derived from naphtha-oil, a reduction in its cost is critical. We found that Moniliella megachiliensis, a highly osmotolerant yeast strain, can utilize nonrefined glycerol waste derived from palm oil or beef tallow and convert it to erythritol. Cell growth on glycerol was almost the same as on glucose, and the cells could grow in up to 300 mg ml(-1) glycerol. When 200 mg ml(-1) nonrefined glycerol was supplied, the yield of erythritol from the glycerol was approx. 60%, which is slightly higher than that obtained using glucose. The cost of glycerol waste is considerably lower than that of glucose. Thus, the conversion of glycerol waste into valuable erythritol, proposed here, is attractive and promising from the viewpoint of ensuring a supply of C4 hydrocarbons and utilizing a waste natural resource. A shortage of C4 hydrocarbon depending much on naptha-oil has become urgent problem due to rapid reduction of naphtha plants together with global energy revolution. Erythritol, obtained by fermentation, is a rare C4 polyol that can be converted to C4 hydrocarbons. Erythritol is considerably expensive than hydrocarbons, a reduction in cost is critical issue. To meet this, we proposed to utilize low-cost glycerol waste from bio-diesel fuel as a carbon source. Moniliella megachiliensis successfully converted glycerol waste to erythritol. This proposal is promising to obtain C4 hydrocarbon substitute, and concomitantly to dispose a large amount of glycerol waste discharged. © 2015 The Authors published by John Wiley & Sons Ltd on

  15. On the role of the activation procedure of supported hydrotalcites for base catalyzed reactions: Glycerol to glycerol carbonate and self-condensation of acetone

    NARCIS (Netherlands)

    Álvarez, M.G.; Frey, A.M.; Bitter, J.H.; Segarra, A.M.; de Jong, K.P.; Medina, F.

    2013-01-01

    Bulk and carbon nanofiber supported MgAl hydrotalcites have been investigated as solid base catalysts for the synthesis of glycerol carbonate and dicarbonate and for the self-condensation of acetone. The supported materials exhibited a 300 times higher activity compared to bulk activated hydrotalcit

  16. EFFECT OF CORN STEEP LIQUOR CONCENTRATION ON GLYCEROL PRODUCTION AND KINETIC ANALYSIS OF GLYCEROL FERMENTATION%玉米浆浓度对甘油发酵的影响及动力学

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In batch cultures of Candida krusei, the effect of corn steep liquor (CSL) concentration was investigated. The result showed that glycerol yield was greatly affected by CSL concentration. Higher glycerol yield was attained when the initial CSL concentration in the medium was 9 g.L-1. The fermentation kinetics were studied and the parameters for cell growth, maintenance, and glycerol production were obtained. Material balance revealed by product formation during the growth phase and suggested a fed-batch culture strategy.

  17. Use of glycerol-preserved corneas for corneal transplants

    Directory of Open Access Journals (Sweden)

    Neeti Gupta

    2017-01-01

    Full Text Available Purpose: This study was carried out to see the results of glycerol-preserved cornea (GPC in emergency situation when fresh corneal tissue was not available. The aim was to study the outcome of corneal transplantation using GPC. Methods: This was a retrospective study. The medical records of all the patients were reviewed, who underwent keratoplasty using “GPC” during the period from October 2011 to December 2015. The indication of keratoplasty, duration of preservation of the GPC, and its outcome were analyzed. Descriptive statistics were applied. Results: Out of the 222 penetrating keratoplasty (PKP performed over the study period, the GPC was used in 34 patients (males = 31, 91.2% aged 15–74 years. Therapeutic keratoplasty was performed in all cases in this cohort except one in which tectonic keratoplasty was done. The primary indication of PKP (91.2% was infectious keratitis. Of these, 20 (64.5% patients presented with perforated corneal ulcers. Post-PKP, ocular anatomy was preserved in 91.2%, and visual acuity of perception of light positive and accurate projection of rays in all the quadrants was obtained in 76.5% cases. Complications included glaucoma (n = 12, 35.1%, phthisis bulbi (n = 2, 5.9%, and graft reinfection and endophthalmitis after PKP (n = 1, 2.9%. The secondary procedure post-GPC and PKP were trabeculectomy with mitomycin C (n = 7, 58.3% in patients not controlled on topical antiglaucoma medication. Optical keratoplasty was performed in (n = 3 8.8% patients and triple procedure in (n = 2 5.8% patients with good visual acuity postprocedure. Conclusions: Acellular GPCs are useful in emergency keratoplasty to avoid loss of vision and can save the eye.

  18. Protective effect of sulfated chitosan of C3 sulfation on glycerol-induced acute renal failure in rat kidney.

    Science.gov (United States)

    Xing, Ronge; Liu, Song; Yu, Huahua; Qin, Yukun; Chen, Xiaolin; Li, Kecheng; Li, Pengcheng

    2014-04-01

    The purpose of this study was to investigate the protective effects of sulfated chitosan of C3 sulfation (TCTS) on the glycerol-induced acute renal failure. Compared with the normal group, rats from model group exhibited collecting duct and medullary ascending limb dilation and casts by glycerol treating. TCTS, which was injected to pretreat rats by glycerol, exerted a protective effect. The results showed that serum creatinine and blood urea nitrogen were markedly increased in glycerol-treated rats. It is proved that TCTS reduced their levels significantly. Ions level in plasma and urine were significantly changed in glycerol-treated rats, whereas TCTS almost recovered their levels back to normal. For female rats, administration of TCTS reduced their mortality. This study showed a noticeable renal morphologic and functional protection by TCTS in glycerol-induced acute renal failure.

  19. [Effects of ggpS over-expression on glycosylglycerol and glycerol biosynthesis of Synechocystis sp. PCC 6803].

    Science.gov (United States)

    Ma, Peizhen; Tan, Xiaoming; Lü, Xuefeng; Tian, Jiyuan

    2016-03-01

    To study the roles of glucosylglycerol phosphate synthase (Ggps) in glucosylglycerol (GG) and glycerol biosynthesis, we over-expressed Ggps from either Synechocystis sp. PCC 6803 or Synechococcus sp. PCC 7002 in a Synechocystis strain with a high GG titer, and determined the GG and glycerol accumulation in the resultant mutants grown under different NaCl-stress conditions. Ion chromatography results revealed that GG yield was not improved, but glycerol production was significantly enhanced by over-expression of Ggps from Synechocystis sp. PCC 6803 (6803ggpS). In addition, increasing the NaCl concentration of medium from 600 to 900 mmol/L led to a further 75% increase of glycerol accumulation in the mutant strain with 6803ggpS over-expression. These findings show the role of ggpS in driving the carbon flux to the glycerol biosynthesis pathway, and will be helpful for further improvement of GG and glycerol production in Synechocystis.

  20. Metabolic parameters in rats receiving different levels of oral glycerol supplementation.

    Science.gov (United States)

    Lisenko, K G; Andrade, E F; Lobato, R V; Orlando, D R; Damin, D H C; Costa, A C; Lima, R R; Alvarenga, R R; Zangeronimo, M G; Sousa, R V; Pereira, L J

    2015-04-01

    The use of glycerol in the diets for animals is of interest because it is a residue of biodiesel production and rich in energy. Thus, this study aimed to evaluate metabolic and physiological parameters of rats receiving supplemental pure glycerol by gavage. We used 30 Wistar rats (initial weight 202.7 ± 29.98 g) receiving 0 (control/saline), 200, 400, 800 and 1600 mg glycerol/kg of body weight (bidistilled glycerine, 99.85% glycerol) beside food and water ad libitum for 28 days. We used a completely randomised design with five treatments and six replicates. At the end of the experiment, the animals were killed, and the results showed that there was no change (p > 0.05) in the intake and excretion of water, the average daily weight gain, dry matter, ash and crude protein in the carcass or plasma triacylglycerols. There was a beneficial effect (p < 0.05) up to a dose of 800 mg/kg glycerol on feed intake, percentage of carcass fat, plasma levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), high-density lipoprotein (HDLc) and low-/very low-density lipoprotein (LDLc + VLDLc). The levels of total cholesterol and glucose were increased with up to a dose of 800 mg/kg glycerol (but remained within the normal range); they were reduced with the dose of 1600 mg/kg. The total leucocyte count tended to be reduced, although it was within the reference values for rats. There were no renal or pancreatic lesions. In conclusion, glycerol presented as a safe supplement at the studied doses, even having some beneficial effects in a dose-dependent manner in rats.

  1. Structural Characterizations of Glycerol Kinase: Unraveling Phosphorylation-Induced Long-Range Activation

    Energy Technology Data Exchange (ETDEWEB)

    Yeh, Joanne I.; Kettering, Regina; Saxl, Ruth; Bourand, Alexa; Darbon, Emmanuelle; Joly, Nathalie; Briozzo, Pierre; Deutscher, Josef; (Pitt); (CNRS-CRMD)

    2009-09-11

    Glycerol metabolism provides a central link between sugar and fatty acid catabolism. In most bacteria, glycerol kinase plays a crucial role in regulating channel/facilitator-dependent uptake of glycerol into the cell. In the firmicute Enterococcus casseliflavus, this enzyme's activity is enhanced by phosphorylation of the histidine residue (His232) located in its activation loop, approximately 25 A from its catalytic cleft. We reported earlier that some mutations of His232 altered enzyme activities; we present here the crystal structures of these mutant GlpK enzymes. The structure of a mutant enzyme with enhanced enzymatic activity, His232Arg, reveals that residues at the catalytic cleft are more optimally aligned to bind ATP and mediate phosphoryl transfer. Specifically, the position of Arg18 in His232Arg shifts by approximately 1 A when compared to its position in wild-type (WT), His232Ala, and His232Glu enzymes. This new conformation of Arg18 is more optimally positioned at the presumed gamma-phosphate location of ATP, close to the glycerol substrate. In addition to structural changes exhibited at the active site, the conformational stability of the activation loop is decreased, as reflected by an approximately 35% increase in B factors ('thermal factors') in a mutant enzyme displaying diminished activity, His232Glu. Correlating conformational changes to alteration of enzymatic activities in the mutant enzymes identifies distinct localized regions that can have profound effects on intramolecular signal transduction. Alterations in pairwise interactions across the dimer interface can communicate phosphorylation states over 25 A from the activation loop to the catalytic cleft, positioning Arg18 to form favorable interactions at the beta,gamma-bridging position with ATP. This would offset loss of the hydrogen bonds at the gamma-phosphate of ATP during phosphoryl transfer to glycerol, suggesting that appropriate alignment of the second substrate of

  2. Effects of glycerol on human skin damaged by acute sodium lauryl sulphate treatment.

    Science.gov (United States)

    Atrux-Tallau, Nicolas; Romagny, Céline; Padois, Karine; Denis, Alain; Haftek, Marek; Falson, Françoise; Pirot, Fabrice; Maibach, Howard I

    2010-08-01

    Glycerol, widely used as humectant, is known to protect against irritants and to accelerate recovery of irritated skin. However, most studies were done with topical formulations (i.e. emulsions) containing glycerol in relatively high amounts, preventing drawing conclusions from direct effects. In this study, acute chemical irritations were performed on the forearm with application of a 10% sodium lauryl sulphate (SLS) aqueous solution under occlusion for 3 h. Then, glycerol aqueous solutions from 1 to 10% were applied under occlusion for 3 h. After elimination of moist excess consecutive to occlusive condition, in ambient air for 15 and 30 min, skin barrier function was investigated by dual measurement of skin hydration and transepidermal water loss (TEWL). Treatments with SLS solution under occlusion significantly increased TEWL and decreased skin hydration as assessed by capacitance measurements. The SLS irritant property was raised by the occlusion and the water barrier function as well as water content appeared impaired. Recovery with glycerol at low doses was remarkable through a mechanism that implies its hygroscopic properties and which is saturable. This precocious effect acts through skin rehydration by enhancing water-holding capacity of stratum corneum that would facilitate the late physiological repair of impaired skin barrier. Thus, glycerol appears to substitute for natural moisturizing factors that have been washed out by the detergent action of SLS, enhancing skin hydration but without restoring skin barrier function as depicted by TEWL values that remained high. Thus, irritant contact dermatitis treated with glycerol application compensate for skin dehydration, favouring physiological process to restore water barrier function of the impaired skin. Empirical use of glycerol added topical formulations onto detergent altered skin was substantiated in the present physicochemical approach.

  3. Glycerol effects on the formation and rheology of hexagonal phase and related gel emulsion.

    Science.gov (United States)

    Alam, Mohammad Mydul; Aramaki, Kenji

    2009-08-15

    We have investigated the effects of glycerol on the formation and rheology of hexagonal phase (H(1)) and related O/H(1) gel emulsion in the water/C(12)EO(8)/dodecane system at 25 degrees C. It has been found that the aqueous solution of C(12)EO(8) forms H(1) phase, which could solubilize some amounts of dodecane. Beyond the solubilization limit, oil is separated and a two-phase region or H(1)+O phase appeared. Due to high viscosity of the H(1) phase, allows forming O/H(1) gel emulsion at the H(1)+O region. Rheological measurements (without glycerol) have shown that the rheogram of the H(1) phase does not change drastically with the addition of oil but the system is shifted to longer relaxation time. Simultaneously, the values of the absolute value(eta(*)) are found to increase with the addition of oil, which has been described with the neighboring micellar interaction. The rheogram of the O/H(1) gel emulsion shows gel type nature (G'>G'') but the viscosity monotonically decreases with increasing oil content, which could be due to the lower volume fraction of the continuous phase (H(1) phase). Addition of glycerol has brought an order-order transition or the microstructural transition from H(1)-lamellar (L(alpha)) phase, which is manifested from rheology and SAXS measurements. Viscosity of the O/H(1) gel emulsion also decreases with increasing glycerol content. Digital images show the physical appearance of the gel emulsion changes from turbid to transparent, which is depended on the glycerol concentration (since glycerol matches the refractive index of the H(1) phase and dodecane). Structural parameters of the H(1) phase have been evaluated with the help of Bohlin's model and found that the coordination number of the H(1) phase depends not only the oil and glycerol concentrations but also temperature.

  4. DIRECT ETHOXYLATION OF GLYCEROL MONO OLEATE FROM PALM OIL DERIVATE AS A NOVEL NON-IONIC POLYMERIC SURFACTANT

    OpenAIRE

    2012-01-01

    The work investigates ethoxylation of glycerol mono oleate (GMO) performed in the presence of an alkaline catalyst. Glycerol mono oleate applied was derivated from Indonesian palm oil. The reaction was conducted with variation of Glycerol mono oleate : ethylene oxide ratio, temperature, and catalyst concentration. Forier Transform Infra Red (FTIR) and Nuclear Magnetic Resonance (NMR) analysis showed products with degrees of ethoxylation n=2 and n=3. FTIR analysis of products gave a new peak a...

  5. Glycerol as a reference material for fecal fat quantitation using low-resolution time domain ¹H NMR spectroscopy.

    Science.gov (United States)

    Corsetti, James P; Sterry, Judy; Sakpal, Manisha; Lefevre, Brian H; Ryan, Dan

    2011-11-01

    To assess glycerol as reference material for low-resolution time-domain (1)H NMR analysis of fecal fat. NMR analysis of fecal fat in stool samples with added glycerol was used to assess linearity, recovery, and relationship with NMR lipid signal. The study revealed for added glycerol excellent linearity (r=0.9998), recovery (101-104%), and linear relationship with simulated fecal fat content. Glycerol is an effective reference material for NMR fecal fat analysis. Copyright © 2011 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  6. Gpd1 and Gpd2 Fine-Tuning for Sustainable Reduction of Glycerol Formation in Saccharomyces cerevisiae▿

    OpenAIRE

    Hubmann, Georg; Guillouet, Stephane; Nevoigt, Elke

    2011-01-01

    Gpd1 and Gpd2 are the two isoforms of glycerol 3-phosphate dehydrogenase (GPDH), which is the rate-controlling enzyme of glycerol formation in Saccharomyces cerevisiae. The two isoenzymes play crucial roles in osmoregulation and redox balancing. Past approaches to increase ethanol yield at the cost of reduced glycerol yield have most often been based on deletion of either one or two isogenes (GPD1 and GPD2). While single deletions of GPD1 or GPD2 reduced glycerol formation only slightly, the ...

  7. A low-cost synthesis of biodiesel at room temperature and purification of by-product glycerol for reuse

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Yogesh C.; Singh, Bhaskar; Agrawal, Shweta [Banaras Hindu University, Department of Applied Chemistry, Institute of Technology, Varanasi (India)

    2012-03-15

    Biodiesel has been synthesized from used frying oil at room temperature (35 C) using NaOH and CH{sub 3}ONa as homogeneous catalyst and methanol as reactant. Glycerol has been obtained as a by-product which comprised of impurities such as unreacted methanol, inorganic metals, and traces of triglycerides. The inorganic materials present in glycerol were adsorbed on the surface of activated carbon derived from rice husk. Glycerol is then acidified with 1.2 M H{sub 2}SO{sub 4} to form two layers. The upper layer comprised of free fatty acids, and the bottom layer comprised of a glycerol-rich layer. The bottom layer was decanted and neutralized with an aqueous solution of 10 M NaOH and heated at 110 C for 2.5 h to remove the residual water in the glycerol. Further extraction of glycerol with ethanol gives glycerol of high purity. For removal of ethanol from the glycerol, the solution was heated up to 80 C for 30 min. The purity of glycerol was verified by analysis on {sup 13}C-NMR. The upper free fatty acid layer is confirmed with the help of the treatment of this layer with base solution (NaOH) to give soap. Formation of soap is confirmed with the help of Fourier transform infrared spectroscopy. (orig.)

  8. Biophysical assessment of aquaporin-9 as principal facilitative pathway in mouse liver import of glucogenetic glycerol.

    Science.gov (United States)

    Calamita, Giuseppe; Gena, Patrizia; Ferri, Domenico; Rosito, Anna; Rojek, Aleksandra; Nielsen, Søren; Marinelli, Raúl A; Frühbeck, Gema; Svelto, Maria

    2012-06-01

    Lipolytic glycerol, released from adipocytes, flows through the bloodstream to the liver, where its utilisation in supplying hepatocyte gluconeogenesis is rate-limited by the permeation step. An aquaglyceroporin expressed in hepatocytes, aquaporin-9 (AQP9), has been often linked to liver uptake of glycerol. However, the truthfulness of this postulation and the potential existence of additional pathways of glycerol import by hepatocytes have never been assessed directly. Here, we define the identity and extent of liver glycerol transport and evaluate the correlation between hepatic AQP9 expression and glycerol permeability (P(gly) ) in AQP9(+/+) wild-type mice in different nutritional states and circulating insulin levels. The liver P(gly) of AQP9 null mice is also assessed. By stopped-flow light scattering, facilitated diffusion of glycerol into hepatocytes was indicated by the low Arrhenius activation energy (3.5 kcal/mol) and strong inhibition by phloretin, an AQP9 blocker, that characterised the transport. Although fasting markedly increased hepatic AQP9, a straight parallelism was seen both in quantitative and time-space terms between P(gly) and AQP9 protein in AQP9(+/+) mice kept in fed or fasted/refed states. In line with these findings, the highest P(gly) (P(gly) ≈ 14.0 × 10(-6) cm/s at 20°C) at 18-h fasting coincided with the highest percent of phloretin inhibition (63%). Besides being markedly lower than that in AQP9(+/+) mice, the liver P(gly) of the AQP9 null mice did not increase during fasting. Reverse-transcription PCR analysis showed lack of compensation by AQP3 and AQP7, the other known murine glycerol facilitators, in AQP9 null mice. Overall, these results experimentally prove major functional significance for AQP9 in maximising liver glycerol import during states requiring increased glucose production. If any, alternative facilitated pathways would be of minor importance in transporting glucogenetic glycerol into hepatocytes during starvation

  9. Acute metabolic responses of postpartal dairy cows to subcutaneous glucagon injections, oral glycerol, or both.

    Science.gov (United States)

    Osman, M A; Allen, P S; Mehyar, N A; Bobe, G; Coetzee, J F; Koehler, K J; Beitz, D C

    2008-09-01

    This study examined the effects of multiple subcutaneous glucagon injections with or without co-administration of oral glycerol on energy status-related blood metabolites and hormones of Holstein dairy cows in the first 2 wk postpartum. Twenty multiparous cows were fed a dry cow ration supplemented with 6 kg of cracked corn during the dry period to increase the likelihood of developing postpartal fatty liver syndrome. Cows with a body condition score of >or=3.5 points (1- to 5-point scale) were assigned randomly to 1 of 4 treatment groups: saline, glucagon, glycerol, or glucagon plus glycerol. Following treatment, serial blood samples were collected over an 8-h period to determine the effects of glucagon and glycerol on blood metabolites and hormones. Treatment effects were determined by comparing the concentrations of metabolites and hormones during the first 4-h period and the entire 8-h period after treatment administration (time 0) with the concentration of the same compounds at time 0 on d 1, 7, and 13 postpartum. Administration of glucagon alone increased concentrations of plasma glucagon and insulin on d 1, 7, and 13 and increased plasma glucose and decreased plasma nonesterified fatty acids (NEFA) on d 7 and 13 postpartum relative to the saline group. Administration of glycerol alone increased plasma glucose on d 7 and plasma triacylglycerols on d 1 postpartum. Glycerol administration also decreased plasma glucagon and NEFA on d 1, 7, and 13 and plasma beta-hydroxybutyrate (BHBA) on d 1 postpartum relative to the saline group. Administration of glucagon plus glycerol increased and sustained concentrations of plasma glucagon, glucose, and insulin on d 1, 7, and 13 and decreased plasma NEFA on d 1, 7, and 13 and BHBA on d 1 and 7. Early postpartal treatment of dairy cows with glucagon plus glycerol increased plasma glucose and insulin, decreased plasma NEFA and BHBA, and increased secretion of liver NEFA as plasma triacylglycerols. This suggests that glucagon

  10. How does glycerol enhance the bioprotective properties of trehalose? Insight from protein-solvent dynamics.

    Science.gov (United States)

    Bellavia, Giuseppe; Paccou, Laurent; Guinet, Yannick; Hédoux, Alain

    2014-07-31

    We present Raman investigations on lysozyme/trehalose/glycerol solutions at low water content, from room temperature up to the occurrence of the protein thermal denaturation. We studied the Amide I band and the low-frequency spectrum as a function of the glycerol content. The former allows us to monitor the protein unfolding; the latter probes the protein and solvent dynamics in anharmonic and quasi-harmonic regimes. It was shown that adding a small amount of glycerol to trehalose stiffens the dry matrix in which proteins are embedded, thus improving their stability. The analysis of the Amide I band reveals that glycerol enhances the stabilization effect of trehalose on proteins for low water content, but still liquid, systems. Data show that the protein unfolding temperature has a maximum value around 5% Glyc/TRE g/g. The overlapping low-frequency contributions, corresponding to fast anharmonic and quasi-harmonic motions, respectively, related to the mean square displacement ⟨u(2)⟩ and the vibrational density of states (VDOS) usually determined by neutron scattering experiments, have been carefully analyzed to understand the effect of glycerol. The intensity of the quasi-elastic scattering (QES) peak reveals a dynamical-like transition at high temperatures, close to the denaturation temperature. This one, as well as the low-frequency vibrational modes, reflects the same enhanced trend of the Amide I band with respect to the glycerol concentration, but at lower temperatures. A linear correlation is found among the transition temperatures of both the dynamical-like transition and the low-frequency modes, as well as the temperature dependent change of the Amide I frequency. This confirms the solvent dynamics as a necessary precursor to promote protein unfolding. Glycerol anti-plasticizes the matrix with respect to the trehalose by enhancing the stability of the protein in a more rigid trehalose/water/glycerol matrix. As expected from the analysis of the Amide I

  11. Pharmacological investigations of Punica granatum in glycerol-induced acute renal failure in rats

    Directory of Open Access Journals (Sweden)

    Amrit Pal Singh

    2011-01-01

    Full Text Available Objective : The present study was designed to investigate the ameliorative potential and possible mechanism of hydroalcoholic extract of flowers of P. granatum in glycerol-induced acute renal failure (ARF in rats. Materials and Methods : The rats were subjected to rhabdomyolytic ARF by single intramuscular injection of hypertonic glycerol (50% v/v; 8 ml/kg and the animals were sacrificed after 24 hours of glycerol injection. The plasma creatinine, blood urea nitrogen, creatinine clearance, and histopathological studies were performed to assess the degree of renal injury. Results : Pretreatment with hydroalcoholic extract of flowers of P. granatum (125 and 250 mg/kg p.o. twice daily for 3 days significantly attenuated hypertonic glycerol-induced renal dysfunction in a dose-dependent manner. BADGE (Bisphenol-A-diglycidyl ether (30 mg/kg, a peroxisome proliferator-activated receptor (PPAR-γ antagonist, and N(omega-nitro-l-arginine-methyl ester (L-NAME (10, 20, and 40 mg/kg, nitric oxide synthase inhibitor, were employed to explore the mechanism of renoprotective effects of Punica granatum. Administration of BADGE (30 mg/kg and L-NAME (40 mg/kg abolished the beneficial effects of P. granatum in glycerol-induced renal dysfunction. Conclusion : Hydroalcoholic extract of flowers of P. granatum has ameliorative potential in attenuating myoglobinuric renal failure and its renoprotective effects involve activation of PPAR-γ and nitric oxide-dependent signaling pathway.

  12. Interruption of glycerol pathway in industrial alcoholic yeasts to improve the ethanol production

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Zhong-peng; Zhang, Liang; Ding, Zhong-yang; Shi, Gui-Yang [Jiangnan Univ., Wuxi (China). Key Lab. of Industrial Biotechnology, Ministry of Education; Jiangnan Univ., Wuxi (China). Lab. of Biomass Refinery and Processing, School of Biotechnology; Wang, Zheng-Xiang [Jiangnan Univ., Wuxi (China). Key Lab. of Industrial Biotechnology, Ministry of Education

    2009-02-15

    The two homologous genes GPD1 and GPD2, encoding two isoenzymes of NAD{sup +}-dependent glycerol-3-phosphate dehydrogenase in industrial yeast Saccharomyces cerevisiae CICIMY0086, had been deleted. The obtained two kinds of mutants gpd1{delta} and gpd2{delta} were studied under alcoholic fermentation conditions. gpd1{delta} mutants exhibited a 4.29% (relative to the amount of substrate consumed) decrease in glycerol production and 6.83% (relative to the amount of substrate consumed) increased ethanol yield while gpd2{delta} mutants exhibited a 7.95% (relative to the amount of substrate consumed) decrease in glycerol production and 7.41% (relative to the amount of substrate consumed) increased ethanol yield compared with the parental strain. The growth rate of the two mutants were slightly lower than that of the wild type under the exponential phase whereas ANG1 (gpd1{delta}) and the decrease in glycerol production was not accompanied by any decline in the protein content of the strain ANG1 (gpd1{delta}) but a slight decrease in the strain ANG2 (gpd2{delta}). Meanwhile, dramatic decrease of acetate acid formation was observed in strain ANG1 (gpd1{delta}) and ANG2 (gpd2{delta}) compared to the parental strain. Therefore, it is possible to improve the ethanol yield by interruption of glycerol pathway in industrial alcoholic yeast. (orig.)

  13. Glycerol and urea can be used to increase skin permeability in reduced hydration conditions.

    Science.gov (United States)

    Björklund, Sebastian; Engblom, Johan; Thuresson, Krister; Sparr, Emma

    2013-12-18

    The natural moisturizing factor (NMF) is a group of hygroscopic molecules that is naturally present in skin and protects from severe drying. Glycerol and urea are two examples of NMF components that are also used in skin care applications. In the present study, we investigate the influence of glycerol and urea on the permeability of a model drug (metronidazole, Mz) across excised pig skin membranes at different hydrating conditions. The degree of skin hydration is regulated by the gradient in water activity across the membrane, which in turn depends on the water activity of the formulation in contact with the skin membrane. Here, we determine the water activity of all formulations employed using an isothermal calorimetric method. Thus, the gradient in water activity is controlled by a novel experimental set-up with well-defined boundary conditions on both sides of the skin membrane. The results demonstrate that glycerol and urea can retain high steady state flux of Mz across skin membranes at dehydrating conditions, which otherwise would decrease the permeability due to dehydration. X-ray diffraction measurements are performed to give insight into the effects of glycerol and urea on SC molecular organization. The novel steady state flux results can be related to the observation that water, glycerol, and urea all affect the structural features of the SC molecular components in a similar manner.

  14. Purification and properties of two different dihydroxyacetone reductases in Gluconobacter suboxydans grown on glycerol.

    Science.gov (United States)

    Adachi, Osao; Ano, Yoshitaka; Shinagawa, Emiko; Matsushita, Kazunobu

    2008-08-01

    It is well known that in oxidative fermentation microbial growth is improved by the addition of glycerol. In a wild strain, glycerol was converted rapidly to dihydroxyacetone (DHA) quantitatively in the early growth phase by the action of quinoprotein glycerol dehydrogenase (GLDH), and then DHA was incorporated into the cells by the early stationary phase. Two DHA reductases (DHARs), NADH-dependent (NADH-DHAR) (EC 1.1.1.6) and NADPH-dependent (NADPH-DHAR) (EC 1.1.1.156), were detected in the same cytoplasm of Gluconobacter suboxydans IFO 3255. The former appeared to be inducible and labile in nature while the latter was constitutive and stable. The two DHARs were separated each other and were finally purified to crystalline enzymes. This report might be the first one dealing with NADPH-DHAR that has been crystallized. The two DHARs were specific only to DHA reduction to glycerol and thus contributed to cytoplasmic DHA metabolism, resulting in an improved biomass yield with the addition of glycerol.

  15. Crystallization of Ice in Aqueous Solutions of Glycerol and Dimethyl Sulfoxide. 1. A Comparison of Mechanisms

    Science.gov (United States)

    Hey; Macfarlane

    1996-04-01

    The crystallization of ice from aqueous solutions of glycerol and dimethyl sulfoxide (Me2SO) has been studied using differential scanning calorimetry. In particular, the ice crystallization behavior of glycerol and Me2SO solutions containing approximately the same mole percent solute concentration (i.e., approximately 16 mol%) has been compared. These solutions (45 w/w% Me2SO (15.9 mol%) and 50 w/w% glycerol (16.4 mol%)) were shown to exhibit markedly different ice crystallization properties. For example, the peak homogeneous nucleation temperature of the Me2SO solution was observed to be 3°C above Tg, whereas the peak homogeneous nucleation temperature of the glycerol solution was shown to be 20°C above Tg. Further, the 50 w/w% glycerol solution was shown to devitrify at temperatures close to those of the peak nucleation rate, whereas the Me2SO solution was found to devitrify at temperatures much higher than the peak nucleation temperature. This, along with evidence from emulsion-based calorimetry experiments, indicates that the nucleation leading to devitrification in 45 w/w% Me2SO solutions is largely heterogeneous in nature.

  16. Energy balance of biofuel production from biological conversion of crude glycerol.

    Science.gov (United States)

    Zhang, Xiaolei; Yan, Song; Tyagi, Rajeshwar D; Surampalli, Rao Y; Valéro, Jose R

    2016-04-01

    Crude glycerol, a by-product of biodiesel production, has gained significant attention as a carbon source for biofuel production. This study evaluated the energy balance of biodiesel, hydrogen, biogas, and ethanol production from 3.48 million L of crude glycerol (80% w/v). The conversion efficiency (energy output divided by energy invested) was 1.16, 0.22, 0.27, and 0.40 for the production of biodiesel, hydrogen, biogas, and ethanol respectively. It was found that the use of crude glycerol for biodiesel production was an energy gain process, with a positive energy balance and conversion efficiency of greater than 1. The energy balance revealed a net energy gain of 5226 GJ per 1 million kg biodiesel produced. Production of hydrogen, biogas and ethanol from crude glycerol were energy loss processes. Therefore, the conversion of crude glycerol to lipids and subsequently to biodiesel is suggested to be a better option compared to hydrogen, biogas, or ethanol production with respect to energy balance.

  17. Synergetic hydrothermal co-liquefaction of crude glycerol and aspen wood

    DEFF Research Database (Denmark)

    Pedersen, Thomas Helmer; Jasiunas, Lukas; Casamassima, Luca

    2015-01-01

    Crude glycerol-assisted hydrothermal co-liquefaction of aspen wood was studied in batch micro-reactors. An experimental matrix of 14 experiments was defined to investigate the effects of three different process parameters on the yields of biocrude and char, and on biocrude quality. Co-processing ......Crude glycerol-assisted hydrothermal co-liquefaction of aspen wood was studied in batch micro-reactors. An experimental matrix of 14 experiments was defined to investigate the effects of three different process parameters on the yields of biocrude and char, and on biocrude quality. Co......-processing aspen wood and neat glycerol led to a significant reduction in the char yield, and glycerol is hypothesized to act as a radical scavenger, alleviating re-polymerization of especially lignin-derived fragments. In the temperature range of 380–420 °C, it was found that biocrude and char yield, and biocrude...... quality were all invariant to the reaction temperature. By increasing the crude glycerol to aspen wood mass ratio from 0:1 to 3:1, char yield was decreased from 18.3% (only aspen wood) to 3.4%. Furthermore, the biocrude quality in terms of the effective hydrogen-to-carbon ratio (H/Ceff) was significantly...

  18. Improved tensile strength of glycerol-plasticized gluten bioplastic containing hydrophobic liquids.

    Science.gov (United States)

    Song, Yihu; Zheng, Qiang

    2008-11-01

    The aim of the present work has been to study the influence of hydrophobic liquids on the morphology and the properties of thermo-molded plastics based on glycerol-plasticized wheat gluten (WG). While the total amount of castor oil and glycerol was remained constant at 30 wt%, castor oil with various proportions with respect to glycerol was incorporated with WG by mixing at room temperature and the resultant mixtures were thermo-molded at 120 degrees C to prepare sheet samples. Moisture absorption, morphology, dynamic mechanical properties, and tensile properties (Young's modulus, tensile strength and elongation at break) of the plastics were evaluated. Experimental results showed that the physical properties of WG plastic were closely related to glycerol to castor oil ratio. Increasing in castor oil content reduces the moisture absorption markedly, which is accompanied with a significant improvement in tensile strength and Young's modulus. These observations were further confirmed in 24 wt% glycerol-plasticized WG plastics containing 6 wt% silicone oil or polydimethylsiloxane (PDMS) liquid rubber.

  19. Effect of Glycerol, as Cryoprotectant in the Encapsulation and Freeze Drying of Microspheres Containing Probiotic Cells

    Directory of Open Access Journals (Sweden)

    Oana Lelia Pop

    2015-05-01

    Full Text Available It is reported that probiotics provide several health benefits as they help in maintaining a good balance and composition of intestinal flora, and increase the resistance against invasion of pathogens. Ensuring adequate dosages of probiotics at the time of consumption is a challenge, because several factors during processing and storage affect the viability of probiotic organisms. Major emphasis has been given to protect the microorganisms with the help of encapsulation technique, by addition of different protectants. In this study, probiotic cells (Bifidobacterium lactis 300B were entrapped in alginate/pullulan microspheres. In the encapsulation formula glycerol was used as cryoprotectant in the freeze drying process for long time storage. It was observed that the survival of Bifidobacterium lactis 300B when encapsulated without cryoprotectant was higher than the formula with glycerol in the fresh obtained microspheres. The addition of glycerol was in order to reduce the deep freezing and freeze drying damages. In the chosen formulations, glycerol did not proved protection for the entrapped probiotic cells in the freeze drying process, for which the use of glycerol as cryoprotectant for alginate/pullulan Bifidobacterium lactis 300B entrapment is not recommended.

  20. Glycerol-plasticised silk membranes made using formic acid are ductile, transparent and degradation-resistant.

    Science.gov (United States)

    Allardyce, Benjamin J; Rajkhowa, Rangam; Dilley, Rodney J; Redmond, Sharon L; Atlas, Marcus D; Wang, Xungai

    2017-11-01

    Regenerated silk fibroin membranes tend to be brittle when dry. The use of plasticisers such as glycerol improve membrane ductility, but, when combined with aqueous processing, can lead to a higher degradation rate than solvent-annealed membranes. This study investigated the use of formic acid as the solvent with glycerol to make deformable yet degradation-resistant silk membranes. Here we show that membranes cast using formic acid had low light scattering, with a diffuse transmittance of less than 5% over the visible wavelengths, significantly lower than the 20% transmittance of aqueous derived silk/glycerol membranes. They had 64% β-sheet content and lost just 30% of the initial silk weight over 6h when tested with an accelerated enzymatic degradation assay, in comparison the aqueous membranes completely degraded within this timeframe. The addition of glycerol also improved the maximum elongation of formic acid derived membranes from under 3% to over 100%. They also showed good cytocompatibility and supported the adhesion and migration of human tympanic membrane keratinocytes. Formic acid based, silk/glycerol membranes may be of great use in medical applications such as repair of tympanic membrane perforation or ocular applications where transparency and resistance to enzymatic degradation are important. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Gelatinization and retrogradation phenomena in starch/montmorillonite nanocomposites plasticized with different glycerol/water ratios.

    Science.gov (United States)

    Lara, Sandra Camila; Salcedo, Felipe

    2016-10-20

    This study aims to gain insights into the intermolecular interactions present in thermoplastic starch (TPS)/montmorillonite (MMT) nanocomposites prepared using water and/or glycerol as plasticizers. Specifically, the impact of using different glycerol/water proportions on the nature of gelatinization and retrogradation processes is studied. Nanocomposites were characterized by rheometry, scanning electron microscopy (SEM) and X-rays diffraction (XRD). It is shown that clay tactoids preferentially interact with glycerol molecules rather than starch macromolecules. Consequently, the effects of MMT incorporation strongly depend on the glycerol/water ratio; when a ratio of 0.5 is used minor variations were observed on the starch gelatinization process-although stronger clays-starch interactions were evident-whereas at higher ratios the addition of clays significantly increased the gelatinization temperature, up to values over 100°C. In the gelatinization process of starch in TPS samples having only glycerol as a plasticizer, the leaching of amylose and the melting of amylopectin crystalline domains seem to occur simultaneously. This different gelatinization mechanism produces a TPS having a substantially different morphology, which exhibited reduced retrogradation characteristics.

  2. γ-decalactone production by Yarrowia lipolytica and Lindnera saturnus in crude glycerol.

    Science.gov (United States)

    Soares, Géssyca P A; Souza, Karla S T; Vilela, Leonardo F; Schwan, Rosane F; Dias, Disney R

    2017-07-03

    Flavor compounds are commonly obtained from chemical synthesis or extracted from plants. These sources have disadvantages, such as racemic mixture generation, more steps to yield the final product, low yield, and high cost, making the microbial fermentation an alternative and potential way to obtain flavor compounds. The most important lactone for flavor application is γ-decalactone, which has an aroma of peach and can be obtained by ricinoleic acid biotransformation through yeast peroxisomal β-oxidation. The aim of this work was to use crude glycerol, a residual biodiesel industry, for the production of bioaroma from two different yeasts. Yarrowia lipolytica CCMA 0357 and Lindnera saturnus CCMA 0243 were grown at different concentrations (10, 20, and 30% w/v) of substrates (castor oil and crude glycerol) for γ-decalactone production. L. saturnus CCMA 0243 produced higher concentration of y-decalactone (5.8 g/L) in crude glycerol, whereas Y. lipolytica CCMA 0357 showed a maximum production in castor oil (3.5 g/L). Crude glycerol showed better results for γ-decalactone production when compared to castor oil. L. saturnus CCMA 0243 has been shown to have a high potential for γ-decalactone production from crude glycerol.

  3. Physical, Physicochemical, Mechanical, and Structural Characterization of Films Based on Gelatin/Glycerol and Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Israel Sifuentes-Nieves

    2015-01-01

    Full Text Available A new method to prepare glycerol/gelatin based films, by doping the film with carbon nanotubes (CNTs and sodium dodecyl sulfate (SDS, was proposed. SDS was used to disperse CNTs in gelatin/glycerol films as follows: gelatin/glycerol (GG incubated with equal concentrations of CNT and SDS; GG with 0.001% w/w CNT/SDS; GG with 0.002% CNT/SDS and GG with 0.004% CNT/SDS. Diffractograms of CNT/SDS /glycerol films showed an amorphous structure, being consistent with thermograms involving temperature and fusion enthalpy. Mechanical tests showed 30% increase in elongation at break of GG with 0.004% CNT/SDS, with respect to gelatin/glycerol/SDS control. Samples with CNT had increased water vapor permeability (WVP. The film fractal dimension indicated that, with the addition of the highest concentration of CNT, films with a homogeneous surface were obtained, with probable nanotube inclusion in the protein matrix. According to the results, the easy method used to prepare gelatin composite materials gave place to films with better physical, mechanical, and thermal properties.

  4. Effect of glycerol on sustained insulin release from PVA hydrogels and its application in diabetes therapy.

    Science.gov (United States)

    Cai, Yunpeng; Che, Junyi; Yuan, Minglu; Shi, Xiaohong; Chen, Wei; Yuan, Wei-En

    2016-10-01

    The present study aimed to investigate the effects of glycerol on the physical properties and release of an insulin-loaded polyvinyl alcohol (PVA) hydrogel film. The insulin-loaded hydrogel composite film was produced using the freeze-thawing method, after which the in vitro swelling ratio, transmittance and insulin release, and the in vivo pharmacodynamics, of hydrogels containing various volumes of glycerol were investigated. The results demonstrated that the addition of glycerol reduced the swelling ratio and increased the softness of the PVA hydrogel film. An analysis of insulin release in vitro and of the hypoglycemic effects in rats demonstrated that the PVA hydrogel film had a sustained release of insulin and long-acting effect over 10 days. The results of the present study suggested that, as a hydrophilic plasticizer, glycerol was able to enhance the release of insulin in the early stage of release profile by enhancing the formation of water channels, although the total swelling ratio was decreased. Therefore, the insulin-loaded glycerol/PVA hydrogel film may be a promising sustained-release preparation for the treatment of diabetes.

  5. Investigation of glycerol concentration on corn starch morphologies and gelatinization behaviours during heat treatment.

    Science.gov (United States)

    Chen, Xu; Guo, Li; Du, Xianfeng; Chen, Peirong; Ji, Yishun; Hao, Huili; Xu, Xiaonan

    2017-11-15

    The effects of various glycerol concentrations (0%, 5%, 10%, 20%, and 50%, w/w) on the morphologies and gelatinization behaviours of corn starch were evaluated by confocal laser scanning microscopy (CLSM), scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and rapid visco-analyzer (RVA). When corn starch granules with no added glycerol were treated at 65°C, the granules of corn starch were almost completely broken and tightly connected, and the characteristic birefringence of the starch granules disappeared. Various microscopic techniques revealed that starch gelatinization was delayed to higher temperatures as the glycerol concentration increased. In the presence of glycerol-water systems (5%, 10%, 20%, and 50%, w/w), the peak temperatures of corn starch increased by 1.6°C, 7.4°C, 10.7°C, and 19.7°C, respectively, compared to corn starch in water. The RVA pasting profiles showed that the gelatinization temperature increased as the glycerol concentration increased, which was consistent with polarized light microscope observations and DSC tests. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Liquid phase conversion of Glycerol to Propanediol over highly active Copper/Magnesia catalysts

    Indian Academy of Sciences (India)

    Satyanarayana Murty Pudi; Abdul Zoeb; Prakash Biswas; Shashi Kumar

    2015-05-01

    In this work, a series of Cu/MgO catalysts with different copper metal loading were prepared by the precipitation-deposition method. Their catalytic behaviour was investigated for glycerol hydrogenolysis to 1,2-propanediol (1,2-PDO). The physico-chemical properties of the catalysts were characterized by various techniques such as BET surface area, X-ray diffraction (XRD), temperature programmed reduction (TPR), NH3-temperature programmed desorption (NH3-TPD) and scanning electron microscopy (SEM) methods. The characterization results showed that the copper metal was well-dispersed over MgO support and a new phase Cu-MgO was also identified from XRD results after calcination. The 25Cu/MgO (Cu:25 wt%) catalyst exhibited the highest glycerol conversion of 88.7% and 1,2-PDO selectivity of 91.7% at 210°C, 4.5MPa of hydrogen pressure after 12 h. The high glycerol conversion was mainly due to the Cu dispersion on MgO support and high acidic strength. Further, the effects of temperature, hydrogen pressure, catalyst loading and glycerol concentration were studied over 25Cu/MgO catalyst for optimization of reaction parameters. Kinetic study over highly active 25Cu/MgO catalyst showed that the reaction followed the pseudo second order rate with respect to glycerol and the apparent activation energy was found to be 28.7 ± 0.8 kcal/mol.

  7. Glycerol electro-oxidation on a carbon-supported platinum catalyst at intermediate temperatures

    Science.gov (United States)

    Ishiyama, Keisuke; Kosaka, Fumihiko; Shimada, Iori; Oshima, Yoshito; Otomo, Junichiro

    2013-03-01

    The electro-oxidation of glycerol on a carbon-supported platinum catalyst (Pt/C) in combination with a reaction products analysis was investigated at intermediate temperatures (235-260 °C) using a single cell with a CsH2PO4 proton conducting solid electrolyte. A high current density was achieved. The main products were H2, CO2 and CO but the formation of C2 compounds, such as glycolic acid and ethane, was also observed. In addition, several C3 compounds were detected as minor products. A reaction products analysis revealed that the C-C bond dissociation ratio of glycerol was 70-80% at both low and high potentials (>200 mV vs. reversible hydrogen electrode) at 250 °C, suggesting that rapid dissociation occurs on Pt/C. The reaction products analysis also suggested that hydrogen production via thermal decomposition and/or steam reforming of glycerol (indirect path) and direct electro-oxidation of glycerol (direct path) proceed in parallel. More detailed reaction paths involving C1, C2 and C3 reaction products are discussed as well as the possible rate-determining step in glycerol electro-oxidation at intermediate temperatures.

  8. [BIOCONVERSION OF CRUDE GLYCEROL AND MOLASSES MIXTURE IN BIOSURFACTANTS OF NOCARDIA VACCINII IMB B-7405].

    Science.gov (United States)

    Pirog, T P; Kudrya, N V; Shevchuk, T A; Beregova, K A; Iutynska, G O

    2015-01-01

    The possibility of replacing glucose and pure glycerol in mixed substrates for surtace-active substances (SAS, biosurfactants) biosynthesis of Nocardia vaccinii IMB B-7405 on molasses (sugar production waste) and crude glycerol (by-product of biodiesel production) was established. It was established that the increasing concentration of crude glycerol to 6% in mixture with 1.0% molasses was accompanied by increase of amount of SAS synthesized more than twice, and the increasing content of molasses to 3.0% in mixture with 1.0% crude glycerol--by some decrease in the level of surfactant as compared to that in a medium containing 1.0% monosubstrates. It was shown that the increasing concentration of sodium nitrate to 2-fold in medium cultivation of N. vaccinii IMB B-7405 allowed to increase to 7.0% content of grude glycerol in mixture with 1.0% molasses. Under such conditions of cultivation concentration of exocellular SAS synthesized was 7,5 g/l, that to 1,3 fold higher than in basic medium with a lower content of nitrogen source.

  9. Limitations on quantum key repeaters.

    Science.gov (United States)

    Bäuml, Stefan; Christandl, Matthias; Horodecki, Karol; Winter, Andreas

    2015-04-23

    A major application of quantum communication is the distribution of entangled particles for use in quantum key distribution. Owing to noise in the communication line, quantum key distribution is, in practice, limited to a distance of a few hundred kilometres, and can only be extended to longer distances by use of a quantum repeater, a device that performs entanglement distillation and quantum teleportation. The existence of noisy entangled states that are undistillable but nevertheless useful for quantum key distribution raises the question of the feasibility of a quantum key repeater, which would work beyond the limits of entanglement distillation, hence possibly tolerating higher noise levels than existing protocols. Here we exhibit fundamental limits on such a device in the form of bounds on the rate at which it may extract secure key. As a consequence, we give examples of states suitable for quantum key distribution but unsuitable for the most general quantum key repeater protocol.

  10. EXPERIMENTAL STUDY ON COMBINING SELECTIVE RHIZOTOMY OF DIFFERENT ANTERIOR AND POSTERIOR SACRAL ROOTS FOR RESTORATION OF BLADDER FUNCTION AFTER SPINAL CORD INJURY%选择性骶神经前后根组合切断恢复脊髓损伤后膀胱功能的实验研究

    Institute of Scientific and Technical Information of China (English)

    张世民; 侯春林; 徐瑞生; 傅晓辉

    2001-01-01

    Objective To investigate an alternative procedure for completedenervation of bladder in the supre-cone cord injury to restore the bladder function. Methods Sixteen dogs were included in this study after their spinal cords were transected above the cone. They were divided into 6 groups and performed the rhizotomy of L7 to S3 root in different combination respectively. The bladder and urethra pressure change by electrostimulation during operation and cystometrogram change after operation were tested. Results ①Electrostimulation study: for bladder innervation, S2 was the most important and S1 was secondary. While for urethra invervation, S1 was more important than S2. When the anterior and posterior roots of S1 and S2 were intact with rhizotomy of posterior roots of L7 and S3, stimulated the common or posterior root of S1 and S2, the change of pressure in bladder and urethra was the same. When the anterior roots of S1 and S2 were resected with rhizotomy of posterior roots of L7 and S3, the pressure in bladder and urethra was significant decreased compared to stimulating the corresponding posterior roots. ②Cystometrogram (CMG) study: in the complete deafferented group, resecting the posterior roots of L7 to S3, the bladder became flaccid. While resecting the posterior root of S2 and anterior root of S1 or, resecting the posterior root of S1 and anterior root of S2, combining with rhizotomy of posterior roots of L7 and S3, the CMG curve was similar to the complete deafferented group. In the S1 and S2 intact group, the bladder became spastic. Comclusion Combining rhizotomy of anterior and posterior sacral root in different level has the same effects on bladder as complete deafferentation.%目的 探讨内脊髓损伤后膀胱完全性去神经传入手术的替代方法。方法 健康杂种犬16只经T10平面截瘫后,按L2~S3神经根切断程度的不同,从完全保留到完全切断分成六组,比较术中神经根(总根和后根)电刺激时的

  11. Hysteresis of magnetostructural transitions: Repeatable and non-repeatable processes

    Energy Technology Data Exchange (ETDEWEB)

    Provenzano, Virgil [National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States); Della Torre, Edward; Bennett, Lawrence H. [Department of Electrical and Computer Engineering, The George Washington University, Washington, DC 20052 (United States); ElBidweihy, Hatem, E-mail: Hatem@gwmail.gwu.edu [Department of Electrical and Computer Engineering, The George Washington University, Washington, DC 20052 (United States)

    2014-02-15

    The Gd{sub 5}Ge{sub 2}Si{sub 2} alloy and the off-stoichiometric Ni{sub 50}Mn{sub 35}In{sub 15} Heusler alloy belong to a special class of metallic materials that exhibit first-order magnetostructural transitions near room temperature. The magnetic properties of this class of materials have been extensively studied due to their interesting magnetic behavior and their potential for a number of technological applications such as refrigerants for near-room-temperature magnetic refrigeration. The thermally driven first-order transitions in these materials can be field-induced in the reverse order by applying a strong enough field. The field-induced transitions are typically accompanied by the presence of large magnetic hysteresis, the characteristics of which are a complicated function of temperature, field, and magneto-thermal history. In this study we show that the virgin curve, the major loop, and sequentially measured MH loops are the results of both repeatable and non-repeatable processes, in which the starting magnetostructural state, prior to the cycling of field, plays a major role. Using the Gd{sub 5}Ge{sub 2}Si{sub 2} and Ni{sub 50}Mn{sub 35}In{sub 15} alloys, as model materials, we show that a starting single phase state results in fully repeatable processes and large magnetic hysteresis, whereas a mixed phase starting state results in non-repeatable processes and smaller hysteresis.

  12. L-Lactic acid production from glycerol coupled with acetic acid metabolism by Enterococcus faecalis without carbon loss.

    Science.gov (United States)

    Murakami, Nao; Oba, Mana; Iwamoto, Mariko; Tashiro, Yukihiro; Noguchi, Takuya; Bonkohara, Kaori; Abdel-Rahman, Mohamed Ali; Zendo, Takeshi; Shimoda, Mitsuya; Sakai, Kenji; Sonomoto, Kenji

    2016-01-01

    Glycerol is a by-product in the biodiesel production process and considered as one of the prospective carbon sources for microbial fermentation including lactic acid fermentation, which has received considerable interest due to its potential application. Enterococcus faecalis isolated in our laboratory produced optically pure L-lactic acid from glycerol in the presence of acetic acid. Gas chromatography-mass spectrometry analysis using [1, 2-(13)C2] acetic acid proved that the E. faecalis strain QU 11 was capable of converting acetic acid to ethanol during lactic acid fermentation of glycerol. This indicated that strain QU 11 restored the redox balance by oxidizing excess NADH though acetic acid metabolism, during ethanol production, which resulted in lactic acid production from glycerol. The effects of pH control and substrate concentration on lactic acid fermentation were also investigated. Glycerol and acetic acid concentrations of 30 g/L and 10 g/L, respectively, were expected to be appropriate for lactic acid fermentation of glycerol by strain QU 11 at a pH of 6.5. Furthermore, fed-batch fermentation with 30 g/L glycerol and 10 g/L acetic acid wholly exhibited the best performance including lactic acid production (55.3 g/L), lactic acid yield (0.991 mol-lactic acid/mol-glycerol), total yield [1.08 mol-(lactic acid and ethanol)]/mol-(glycerol and acetic acid)], and total carbon yield [1.06 C-mol-(lactic acid and ethanol)/C-mol-(glycerol and acetic acid)] of lactic acid and ethanol. In summary, the strain QU 11 successfully produced lactic acid from glycerol with acetic acid metabolism, and an efficient fermentation system was established without carbon loss.

  13. Uptake and translocation of arsenite by Pteris vittata L.: effects of glycerol, antimonite and silver.

    Science.gov (United States)

    Mathews, Shiny; Rathinasabapathi, Bala; Ma, Lena Q

    2011-12-01

    AsIII uptake in living cells is through aquaglyceroporin transporters, but it is unknown in arsenic-hyperaccumulator Pteris vittata. We investigated the effects of AsIII analogs glycerol and antimonite (SbIII) at 0-100 mM and aquaporin inhibitor AgNO(3) at 0-0.1 mM on the uptake of 0.1 mM AsIII or AsV by P. vittata over 1-2 h. Glycerol or SbIII didn't impact AsIII or AsV uptake by P. vittata (p aquaporin transporter different from glycerol and SbIII transporters. Further as AsIII analogs and aquaporin inhibitor had no impact on AsV uptake, AsIII and AsV were likely taken up by different transporters in P. vittata. Our results imply a different AsIII transporter in P. vittata from other plants.

  14. Production of filmable medium-chain-length polyhydroxyalkanoates produced from glycerol by Pseudomonas mediterranea.

    Science.gov (United States)

    Pappalardo, Francesco; Fragalà, Manuela; Mineo, Placido G; Damigella, Arcangelo; Catara, Antonino F; Palmeri, Rosa; Rescifina, Antonio

    2014-04-01

    Glycerol is an effective carbon source for the production of scl- and mcl-polyhydroxyalkanoates (PHAs) by Pseudomonas spp. P. mediterranea 9.1 (CFBP 5447) synthesizes an amorphous mcl-PHA when grown on crude glycerol, whereas on both reagent grade (RG) and partially refined (PR) glycerol, it produces two very similar distinctive mcl-PHAs with the unusual property of producing, with the appropriate treatment, a transparent film. Mcl-PHAs recovered after biomass extraction have an average molecular weight of approximately 56,000/63,000 Da. The monomer composition and physicochemical properties of such mcl-PHAs suggest their potential application as a softener of biopolymeric blends for food packaging and medical devices.

  15. Potential of Diverse Prokaryotic Organisms for Glycerol-based Polyhydroxyalkanoate Production

    Directory of Open Access Journals (Sweden)

    Martin Koller

    2015-06-01

    Full Text Available The potential and performance of various Gram-negative, Gram-positive and archaeal wild type microorganisms, and bacterial mixed cultures, as well as the application of genetically engineered strains as whole-cell biocatalysts for glycerol-based polyhydroxyalkanoate production are analyzed and assessed. This encompasses the comparison of growth and polyhydroxyalkanoate accumulation kinetics, thermo-mechanical properties of isolated glycerol-based polyhydroxyalkanoate of different composition on the monomeric level, and the presentation of mathematical models developed to describe glycerol-based polyhydroxyalkanoate production processes. For all these aspects, the article provides a detailed compilation of the contemporary state of knowledge, and gives an outlook to expected future developments.

  16. Development of glycerol-utilizing Escherichia coli strain for the production of bioethanol.

    Science.gov (United States)

    Thapa, Laxmi Prasad; Lee, Sang Jun; Yoo, Hah Young; Choi, Han Suk; Park, Chulhwan; Kim, Seung Wook

    2013-08-15

    The production of bioethanol was studied using recombinant Escherichia coli with glycerol as a carbon source. Glycerol is an attractive feedstock for biofuels production since it is generated as a major byproduct in biodiesel industry; therefore, we investigated the conversion of glycerol to bioethanol using E. coli BL21 (DE3) which harbors several genes in ethanol production pathway of Enterobacter aerogenes KCTC 2190. Fermentation was carried out at 34°C for 42h, pH 7.6, using defined production medium. Under optimal conditions, bioethanol production by the recombinant E. coli BL21 (DE3), strain pEB, was two-fold (3.01g/L) greater than that (1.45g/L) by the wild-type counterpart. The results obtained in this study will provide valuable guidelines for engineering bioethanol producers.

  17. Optimization for microwave-assisted direct liquefaction of bamboo residue in glycerol/methanol mixtures

    Institute of Scientific and Technical Information of China (English)

    Jiulong Xie; Jinqiu Qi; Chungyun Hse; Todd F. Shupe

    2015-01-01

    Bamboo residues were liquefied in a mixture of glycerol and methanol in the presence of sulfuric acid using microwave energy. We investigated the effects of lique-faction conditions, including glycerol/methanol ratio, liq-uefaction temperature, and reaction time on the conversion yield. The optimal liquefaction conditions were under the temperature of 120 °C, the reaction time of 7 min, the glycerol–methanol–bamboo ratio of 8/0/2 (W/W), and the microwave power of 300 W. Maximum conversion yield was 96.7%. The liquid products were separated into two contents (water soluble part and precipitate part) by addi-tion of a sufficient amount of water. By Fourier transform infrared (FT-IR), the water soluble content mainly con-tained glycerol and its derivate and carbohydrate degra-dation products, and the precipitate content was mainly lignin derivatives.

  18. An isocratic HPLC method for the determination of sorbitol and glycerol in pharmaceutical formulations.

    Science.gov (United States)

    Simonzadeh, Ninus; Ronsen, Bruce

    2012-08-01

    Sorbitol and glycerol, along with other inactive ingredients such as preservatives and dyes, are commonly used in various pharmaceutical and personal care products. To accurately assess the effectiveness of various formulations containing sorbitol and/or glycerol, their quantitative determination is essential. In the current study, two types of detectors (a Varian evaporative light scattering detector and an Agilent ultraviolet-visible detector) are evaluated for the assay of working sample solutions. The two detection techniques are complimentary, and a comparison of the results obtained using the two detectors is presented here. The current method is shown to be stability-indicating and free from interference from any of the formulation excipients and potential degradation products. The method is reproducible, accurate, sensitive and selective. It provides enhanced detection sensitivity for sorbitol and comparable sensitivity for glycerol versus similar methods reported in the literature that utilize a refractive index detector for the analysis of either of the two polyols.

  19. Biodiesel Reactor Design with Glycerol Separation to Increase Biodiesel Production Yield

    Directory of Open Access Journals (Sweden)

    Budy Rahmat

    2013-09-01

    Full Text Available The study consisted of reactor design used for transesterification process, effect of glycerol separation ontransesterification reaction, determination of biodiesel quality, and mass balance analysis. The reactor was designed byintegrating circulated pump/stirrer, static mixer, and sprayer that intensify the reaction in the outer tank reactor. The objective was to reduce the use of methanol in excess and to shorten the processing time. The results showed that thereactor that applied the glycerol separation was able to compensate for the decreased use of the reactant methanol from 6:1 to 5:1 molar ratio, and changed the mass balance in the product, including: (i the increase of biodiesel productionfrom 42.37% to 49.34%, and (ii the reduction of methanol in excess from 42.37% to 32.89%. The results suggested that the efficiency of biodiesel production could be increased with the glycerol separation engineering.

  20. Supply Chain Optimization of Integrated Glycerol Biorefinery: GlyThink Model Development and Application

    DEFF Research Database (Denmark)

    Loureiro da Costa Lira Gargalo, Carina; Carvalho, Ana; Gernaey, Krist

    2017-01-01

    for the integrated biorefinery; (iii) government incentives might play a decisive role in the growth of a glycerol-based economy showing improved economic feasibility; and, last, (iv) the optimal product portfolio suggested is based on the production of succinic acid and lactic acid, followed by epichlorohydrin....... To address the optimal design and planning of the glycerol-based biorefinery supply chain, in this work, we propose a multiperiod, multistage, and multiproduct Mixed Integer Linear Programming optimization model, called GlyThink, based upon the maximization of the net present value (NPV). The proposed model...... is able to identify operational decisions, including locations, capacity levels, technologies, and product portfolio, as well as strategic decisions such as inventory levels, production amounts, and transportation to the final markets. Several technologies are considered for the glycerol valorization...

  1. Bioprocessing of glycerol into glyceric Acid for use in bioplastic monomer.

    Science.gov (United States)

    Fukuoka, Tokuma; Habe, Hiroshi; Kitamoto, Dai; Sakaki, Keiji

    2011-01-01

    Utilization of excess glycerol supplies derived from the burgeoning biodiesel industry has recently become very important. Glyceric acid (GA) is one of the most promising glycerol derivatives, and it is abundantly obtained from glycerol by a bioprocess using acetic acid bacteria. In this study, a novel branched-type poly(lactic acid) (PLA) was synthesized by polycondensation of lactide in the presence of GA. The resulting branched PLA had lower crystallinity and glass transition temperatures than the conventional linear PLA, and the peak associated with the melting point of the branched PLA disappeared. Moreover, in a blend of the branched polymer, the crystallization of the linear PLA occurred at a lower temperature. Thus, the branched PLA containing GA synthesized in this study could potentially be used as a novel bio-based modifier for PLA.

  2. Modelling of pyrolysis and combustion of gluten-glycerol-based bioplastics.

    Science.gov (United States)

    Gómez-Martínez, D; Barneto, A G; Martínez, I; Partal, P

    2011-05-01

    Non-isothermal thermogravimetric analysis, under nitrogen and air atmospheres, has been applied to study the thermal degradation of wheat gluten and gluten-glycerol-based bioplastics. In order to explain experimental data, thermal degradation has been simulated using the so-called pseudo-components, which are related to protein fraction (mainly gliadin and glutenin), residual starch and plasticiser. Thus, the proposed models have been used to shed some light on the thermal decomposition of these materials, which have been found affected by their compositions and microstructures. Modelling confirms the experimental bioplastic and gluten isolate compositions, e.g. bioplastic moisture content, starch concentration and the expected gliadin/glutenin ratio. According to the simulation, the glycerol volatilisation is affected by bioplastic moisture content and hindered by the protein matrix. A fact pointing out that glycerol/water blend plays relevant plasticizing roles in the protein matrix through diverse physicochemical interactions.

  3. Growth of Burkholderia sacchari LFM 101 cultivated in glucose, sucrose and glycerol at different temperatures

    Directory of Open Access Journals (Sweden)

    Valkirea Matos Nascimento

    Full Text Available ABSTRACT Polyhydroxyalkanoates (PHAs have attracted major industrial interest as alternatives to conventional plastics. They are produced by several bacteria as cytoplasmic inclusions when nutrients are in limited supply. Among the many factors influencing bacterial growth, the effect of temperature on both specific growth rates and growth yields in terms of carbon source intake is of considerable interest. This study aimed to evaluate the influence of the bacterium Burkholderia sacchari LFM 101 on growth and PHA production, using glucose, sucrose or glycerol as a carbon source, at 30 and 35 °C. The results showed that B. sacchari cultured with glucose at 35 °C presented both higher productivity and polymer yield in dried cell mass. There were no differences in growth rates (μmax in sucrose and glucose. The growth conditions studied were not favorable to glycerol consumption due to limitations in the energy supply from glycerol.

  4. Effects of oxyethylated glycerol cryoprotectants on phase transitions of DPPC model membranes

    Directory of Open Access Journals (Sweden)

    Kasian N. A.

    2015-04-01

    Full Text Available Aim. To determine the effect of the oxyethylated glycerol cryoprotectants (OEGn with polymerization degrees n = 5, 25, 30 on the phase states and phase transitions of dipalmitoylphosphatidylcholine (DPPC-based model membranes. Methods. Differential scanning calorimetry. Results. Model lipid membranes on water/OEGn and water/glycerol subphases with varying cryoprotectant concentrations from 0 to ~ 100 % w/w were studied. A significant raise in the pre-transition and main phase transition temperatures with increasing OEGn concentration was noted whereas the membrane melting peak persist to 100 % w/w OEGn. A sharp increase in the melting enthalpy was observed for OEGn = 5. Conclusions. The solvating ability of the subphase in DPPC membranes decreases in the order water > glycerol > OEGn = 5 > OEGn = 25 > OEGn = 30, which correlates with the relative number of groups effectively contributing to the solvation process.

  5. Production of 2-butanol from crude glycerol by a genetically-engineered Klebsiella pneumoniae strain.

    Science.gov (United States)

    Oh, Baek-Rock; Heo, Sun-Yeon; Lee, Sung-Mok; Hong, Won-Kyung; Park, Jang Min; Jung, You Ree; Kim, Dae-Hyuk; Sohn, Jung-Hoon; Seo, Jeong-Woo; Kim, Chul Ho

    2014-01-01

    Klebsiella pneumoniae was engineered to produce 2-butanol from crude glycerol as a sole carbon source by expressing acetolactate synthase (ilvIH), keto-acid reducto-isomerase (ilvC) and dihydroxy-acid dehydratase (ilvD) from K. pneumoniae, and α-ketoisovalerate decarboxylase (kivd) and alcohol dehydrogenase (adhA) from Lactococcus lactis. Engineered K. pneumonia, ∆ldhA/pBR-iBO (ilvIH–ilvC–ilvD–kivd–adhA), produced 2-butanol (160 mg l−1) from crude glycerol. To increase the yield of 2-butanol, we eliminated the 2,3-butanediol pathway from the recombinant strain by inactivating α-acetolactate decarboxylase (adc). This further engineering step improved the yield of 2-butanol from 160 to 320 mg l−1. This represents the first successful attempt to produce 2-butanol from crude glycerol.

  6. Potential of glycerol and soybean oil for bioremediation of weathered oily-sludge contaminated soil

    Energy Technology Data Exchange (ETDEWEB)

    Nascimento, T.C.F.; Franca, F.P. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Escola de Quimica], E-mail: fpfranca@eq.ufrj.br; Oliveira, F.J.S. [Petroleo Brasileiro S.A. (PETROBRAS), Rio de Janeiro, RJ (Brazil)

    2012-04-15

    The bioremediation of petroleum-contaminated soil was investigated on laboratory scale. This work evaluated the effect of co-substrate addition in tropical climate soil highly contaminated with oily residue. Glycerol and soybean oil were used as auxiliary co-substrates for contaminant degradation. Three different concentrations of co-substrate were tested, and the experiments were carried out over 60 days. The following parameters were monitored: humidity, pH, total heterotrophic bacteria, total fungi, total petroleum hydrocarbons (TPH), and the concentrations of benzo[a]pyrene and chrysene. The soil supplementation with renewable co-substrates improved the efficiency of the biodegradation TPH, with removals of 85% and 83% for glycerol and soybean oil, respectively, compared to a 55% removal yielded by the biodegradation process without supplementation. The use of glycerol increased Chrysene and Benzo[a]pyrene biodegradation by 50%, while soybean oil supplementation increased their removal by 36%. (author)

  7. Glycerol and derived solvents: new sustainable reaction media for organic synthesis.

    Science.gov (United States)

    Díaz-Álvarez, Alba E; Francos, Javier; Lastra-Barreira, Beatriz; Crochet, Pascale; Cadierno, Victorio

    2011-06-14

    The rapid growth of the biodiesel industry has led to a large surplus of its major byproduct, i.e. glycerol, for which new applications need to be found. Research efforts in this area have focused mainly on the development of processes for converting glycerol into value-added chemicals and its reforming for hydrogen production, but recently, in line with the increasing interest in the use of alternative greener solvents, an innovative way to revalorize glycerol and some of its derivatives has seen the light, i.e. their use as environmentally friendly reaction media for synthetic organic chemistry. The aim of the present Feature Article is to provide a comprehensive overview on the developments reached in this field.

  8. Aqueous phase reforming of glycerol over Ni-based catalysts for hydrogen production.

    Science.gov (United States)

    Cho, Su Hyun; Moon, Dong Ju

    2011-08-01

    Aqueous phase reforming of glycerol over Ni-based catalysts for hydrogen production was carried out at 225 degrees C, 23 bar and LHSV = 4 h(-1). The Ni-based catalyst was prepared by an incipient wetness impregnation method. The catalysts before and after the reaction were characterized by N2 physisorption, CO chemisorption, XRD, TPR, SEM and TEM techniques. It was found that Ni(20 wt%)-Co(3 wt%)/gamma-Al2O3 catalyst showed higher glycerol conversion and hydrogen selectivity than Ni(20 wt%)/gamma-Al2O3 catalyst. There are no major changes in Ni particles after the reaction over Ni-Co/gamma-Al2O3 catalyst. The results suggest that the Ni-Co/gamma-Al2O3 catalyst can be applied to the hydrogen production system using APR of glycerol.

  9. High-pressure cloud point data for the system glycerol + olive oil + n-butane + AOT

    Directory of Open Access Journals (Sweden)

    J. P. Bender

    2008-09-01

    Full Text Available This work reports high-pressure cloud point data for the quaternary system glycerol + olive oil + n-butane + AOT surfactant. The static synthetic method, using a variable-volume view cell, was employed for obtaining the experimental data at pressures up to 27 MPa. The effects of glycerol/olive oil concentration and surfactant addition on the pressure transition values were evaluated in the temperature range from 303 K to 343 K. For the system investigated, vapor-liquid (VLE, liquid-liquid (LLE and vapor-liquid-liquid (VLLE equilibrium were recorded. It was experimentally observed that, at a given temperature and surfactant content, an increase in the concentration of glycerol/oil ratio led to a pronounced increase in the slope of the liquid-liquid coexistence curve. A comparison with results reported for the same system but using propane as solvent showed that much lower pressure transition values are obtained when using n-butane.

  10. The effects of peroral glycerol on plasma osmolarity in diabetic patients and healthy individuals

    DEFF Research Database (Denmark)

    Thornit, Dorte Nellemann; Sander, Birgit; la Cour, Morten

    2009-01-01

    Glycerol is used as a peroral treatment of increased intraocular and intracranial pressure due to its osmotic effect despite the potential increase in blood pressure and blood glucose. We examined the effects of peroral glycerol in diabetic patients and healthy individuals on blood pressure......, non-significant increase occurred in blood pressure. Maximal DeltaCG was approximately 1 mM irrespective of the dose and presence of diabetes (p > 0.1). The pOSM response was analysed with a kinetic model and found independent of the presence of diabetes (p = 0.6). The maximal fitted DeltapOSM was 12......, capillary glucose, and plasma osmolarity. On two separate days, 15 diabetic patients ingested glycerol in doses of 855 and 1710 mg/kg body weight in a randomised, unmasked sequence. Five healthy individuals ingested a dose of 1710 mg/kg body weight. Mean arterial blood pressure (MAP), capillary glucose (CG...

  11. Differences in ( sup 14 C)glycerol utilization in normal and familial hypercholesterolemic fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Shireman, R.B.; Durieux, J. (Univ. of Florida Gainesville (USA))

    1991-01-01

    It is known that cultured fibroblasts from familial hypercholesterolemia (FH) patients lack the normal cell receptor for low density lipoprotein (LDL) and that the absence of receptor-mediated transport of LDL cholesterol into these cells results in increased cellular synthesis of cholesterol. After 20 h perincubation in lipid-free medium, cultured FH fibroblasts incorporated significantly greater amounts of ({sup 14}C)glycerol into cellular lipids than did normal fibroblasts. Relative to the control medium which contained only bovine serum albumin (BSA), preincubation with 5% fetal bovine serum or 50 micrograms LDL/ml decreased ({sup 14}C)glycerol incorporation by both cell types. FH cells utilized more ({sup 14}C)glycerol for phospholipid synthesis and less for triglyceride synthesis than normal cells. This study indicates that LDL may be important in the transport of glycerides, as well as cholesterol, to cells.

  12. Cryoprotective effect of glycine betaine and glycerol is not based on a single mechanism.

    Science.gov (United States)

    Popova, A V; Busheva, M R

    2001-01-01

    The mechanism of action of the osmoregulatory substances glycine betaine and glycerol in the course of the freeze-thaw cycle was studied. Photochemical activity of isolated thylakoid membranes was effectively protected during freezing by both solutes by preventing dissociation of the peripheral cold labile proteins - the water splitting system and plastocyanin. It is suggested that the cryoprotective effect of glycine betaine and glycerol is based on a mechanism similar to the well documented stabilization of complex enzymes against dissociation into subunits at high salt concentrations. Specific solute-membrane interactions additionally contribute to the observed cryoprotective effect. The binding of the molecules of glycine betaine and glycerol is limited to the water lipid interface of thylakoid membranes.

  13. Feeding behaviors of transition dairy cows fed glycerol as a replacement for corn.

    Science.gov (United States)

    Carvalho, E R; Schmelz-Roberts, N S; White, H M; Wilcox, C S; Eicher, S D; Donkin, S S

    2012-12-01

    Feed sorting is a natural behavior of dairy cows that can result in inconsistencies in the nutritive value of a total mixed ration (TMR). The objective of this study was to determine the effects of replacing high-moisture corn with glycerol on feed sorting and the feed intake pattern of transition dairy cows. Multiparous Holstein cows (n=26) were paired by expected calving date, housed in individual tie stalls, and fed diets containing either glycerol or high-moisture corn once daily from d -28 to +56 relative to calving. Glycerol was included at 11.5 and 10.8% of the ration dry matter for the pre- and postpartum diets, respectively. The feed consumption pattern was determined by measuring TMR disappearance during the intervals from 0 to 4 h, 4 to 8 h, 8 to 12 h, and 12 to 24 h relative to feed delivery. Feed sorting was determined on d -16, -9, 9, 16, and 51 relative to calving at 4, 8, 12 and 24 h after feeding. The TMR particle size profile was determined at feed delivery and at 4, 8, 12, and 24 after feed delivery by using the Penn State Particle Separator (Nasco, Fort Atkinson, WI) to yield long (>19 mm), medium (8 mm), short (1.18 mm), and fine (consumption pattern were observed after calving. During the prepartum period, cows fed the control diet sorted against long particles, whereas cows fed glycerol did not sort against long particles (77.2 vs. 101.5±3.50% of expected intake for control vs. glycerol; significant treatment effect). The data indicate that addition of glycerol to the TMR alters the feed consumption pattern to increase feed consumption late in the day at the expense of feed consumed immediately after feeding, and it reduces sorting behavior against long particles. Together, these may reduce diurnal variations in the rumen environment to promote greater rumen health in transition cows.

  14. Nonlinear Mathematical Simulation and Analysis of Dha Regulon for Glycerol Metabolism in Klebsiella pneumoniae

    Institute of Scientific and Technical Information of China (English)

    孙亚琴; 叶剑雄; 牟晓佳; 滕虎; 冯恩民; 曾安平; 修志龙

    2012-01-01

    Glycerol may be converted to 1,3-propanediol (1,3-PD) by Klebsiella pneumoniae under anaerobic conditions and glycerol dismutation involves two parallel pathways controlled by the dha regulon. In this study, a fourteen-dimensional nonlinear dynamic system is presented to describe the continuous culture and multiplicity analysis, in which two regulated negative-feedback mechanisms of repression and enzyme inhibition are investigated. The model describing the expression of gene-mRNA-enzyme-product was established according to the repression of the dha regulon by 3-hydroxypropionaldehy (3-HPA). Comparisons between simulated and experimental results indicate that the model can be used to describe the production of 1,3-PD under continuous fermentation. The new model is translated into the corresponding S-system version. The robustness of this model is discussed by using the S-system model and the sensitivity analysis shows that the model is sufficiently robust. The influences of initial glycerol concentration and dilution rate on the biosynthesis of 1,3-PD and the stability of the dha regulon model are investigated. The intracellular concentrations of glycerol, 1,3-PD, 3-HPA, repressor mRNA, repressor, mRNA and protein levels of glycerol dehydratase (GDHt) and 1,3-PD oxydoreductase (PDOR) can be predicted for continuous cultivation. The results of simulation and analysis indicate that 3-HPA accumulation will repress the expression of the dha regulon at the transcriptional level. This model gives new insights into the regulation of glycerol metabolism in K. pneumoniae and explain some of the experimental observations.

  15. Biodiesel biorefinery: opportunities and challenges for microbial production of fuels and chemicals from glycerol waste

    Directory of Open Access Journals (Sweden)

    Almeida João R M

    2012-07-01

    Full Text Available Abstract The considerable increase in biodiesel production worldwide in the last 5 years resulted in a stoichiometric increased coproduction of crude glycerol. As an excess of crude glycerol has been produced, its value on market was reduced and it is becoming a “waste-stream” instead of a valuable “coproduct”. The development of biorefineries, i.e. production of chemicals and power integrated with conversion processes of biomass into biofuels, has been singled out as a way to achieve economically viable production chains, valorize residues and coproducts, and reduce industrial waste disposal. In this sense, several alternatives aimed at the use of crude glycerol to produce fuels and chemicals by microbial fermentation have been evaluated. This review summarizes different strategies employed to produce biofuels and chemicals (1,3-propanediol, 2,3-butanediol, ethanol, n-butanol, organic acids, polyols and others by microbial fermentation of glycerol. Initially, the industrial use of each chemical is briefly presented; then we systematically summarize and discuss the different strategies to produce each chemical, including selection and genetic engineering of producers, and optimization of process conditions to improve yield and productivity. Finally, the impact of the developments obtained until now are placed in perspective and opportunities and challenges for using crude glycerol to the development of biodiesel-based biorefineries are considered. In conclusion, the microbial fermentation of glycerol represents a remarkable alternative to add value to the biodiesel production chain helping the development of biorefineries, which will allow this biofuel to be more competitive.

  16. Aquaporin-10 represents an alternative pathway for glycerol efflux from human adipocytes.

    Directory of Open Access Journals (Sweden)

    Umberto Laforenza

    Full Text Available BACKGROUND: Glycerol outflow from adipocytes has been considered for a decade to be mediated by aquaporin-7, an aquaglyceroporin highly expressed in the adipose tissue. Its involvement in glycerol metabolism has been widely studied also in humans. Recent studies in different aquaporin-7 KO mice models pose two different questions 1 the exact localization of aquaporin-7 in human white adipose tissue; 2 the existence of other aquaglyceroporins that work with aquaporin-7 to guarantee glycerol efflux and thus a normal adiposity in humans. To this purpose we investigated the expression, the localization and the functioning of aquaglyceroporin-10 in subcutaneous white adipose tissue, in isolated and cultured differentiated adipocytes. METHODOLOGY/PRINCIPAL FINDINGS: Aquaporin-7 and -10 were expressed in the white adipose tissue both at mRNA and at protein level. Immunofluorescence revealed aquaporin-7 and -10 labelling in the human adipose tissue both to the plasma membrane and to a thin rim of cytoplasm of adipocytes. Aquaporin-7, but not aquaporin-10, colocalized with the endothelial marker CD34. Human cultured differentiated adipocytes showed an aquaporin-7 and -10 labelling mainly in the cytoplasm and in the lipid droplets with insulin reinforcing the lipid droplets staining and isoproterenol inducing its translocation to the plasma membrane compartment. Water and glycerol permeability measurements using adipocytes and adipose membrane vesicles confirmed the presence of functioning aquaglyceroporins. Aquaporin-10 silencing in human differentiated adipocytes resulted in a 50% decrease of glycerol and osmotic water permeability. CONCLUSIONS/SIGNIFICANCE: The results indicate that aquaporin-7, differently from mice, is present in both adipocyte and capillary plasma membranes of human adipose tissue. Aquaporin-10, on the contrary, is expressed exclusively in the adipocytes. The expression of two aquaglyceroporins in human adipose tissue is

  17. Effect of glycerol on mechanical and physical properties of silver-chitosan nanocomposite films

    Science.gov (United States)

    Susilowati, E.; Kartini, I.; Santosa, S. J.; Triyono

    2016-02-01

    The effect of using glycerol as plasticizer on mechanical and physical properties of silver-chitosan nanocomposite films have been studied. The nanocomposite films were prepared via three steps consisting of silver-chitosan colloidal nanocomposites preparation, adding of glycerol to colloids and silver-chitosan nanocomposites films formation. During the first step, silver ions were reduced by glucose and accelerated by sodium hydroxide (NaOH). Chitosan of 1% (v/v) act as stabilizing agent. Glycerol with volume variation of 0.2, 0.4, 0.6, 8 and 1.0 mL was added colloidal nanocomposites of 60 mL on the second step. On the third step, colloidal nanocomposites were cast on the polypropylene plate and dried at room temperature. The as-prepared films were then neutralized by NaOH and rinsed with distilled water until the filtrate reached the pH of 7. The colloidal nanocomposites were characterized by UV-Vis spectroscopy and transmission electron microscopy (TEM). The film were characterized by X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The mechanical properties, swelling capacity, water vapor permeability (WVP) of the films were also studied. The results indicated that the addition of different amounts of glycerol on colloidal nanocomposites effects on mechanical and physical properties of the resulted nanocomposite films. The elongation and tensile strength were gradually increased as the glycerol amount. Meanwhile, the swelling capacity, WVP, and crystallinity of the film also showed enhancement at increasing glycerol amount. However, the thermal stability decreased.

  18. Glycerol Salicylate-based Pulp-Capping Material Containing Portland Cement.

    Science.gov (United States)

    Portella, Fernando Freitas; Collares, Fabrício Mezzomo; Santos, Paula Dapper; Sartori, Cláudia; Wegner, Everton; Leitune, Vicente Castelo Branco; Samuel, Susana Maria Werner

    2015-01-01

    The purpose of this study was to evaluate the water sorption, solubility, pH and ability to diffuse into dentin of a glycerol salicylate-based, pulp-capping cement in comparison to a conventional calcium hydroxide-based pulp capping material (Hydcal). An experimental cement was developed containing 60% glycerol salicylate resin, 10% methyl salicylate, 25% calcium hydroxide and 5% Portland cement. Water sorption and solubility were determined based on mass changes in the samples before and after the immersion in distilled water for 7 days. Material discs were stored in distilled water for 24 h, 7 days and 28 days, and a digital pHmeter was used to measure the pH of water. The cement's ability to diffuse into bovine dentin was assessed by Raman spectroscopy. The glycerol salicylate-based cement presented higher water sorption and lower solubility than Hydcal. The pH of water used to store the samples increased for both cements, reaching 12.59 ± 0.06 and 12.54 ± 0.05 after 7 days, for Hydcal and glycerol salicylate-based cements, respectively. Both cements were able to turn alkaline the medium at 24 h and sustain its alkalinity after 28 days. Hydcal exhibited an intense diffusion into dentin up to 40 µm deep, and the glycerol salicylate-based cement penetrated 20 µm. The experimental glycerol salicylate-based cement presents good sorption, solubility, ability to alkalize the surrounding tissues and diffusion into dentin to be used as pulp capping material.

  19. Ultraviolet stimulated melanogenesis by human melanocytes is augmented by di-acyl glycerol but not TPA

    Energy Technology Data Exchange (ETDEWEB)

    Friedmann, P.S.; Wren, F.E.; Matthews, J.N. (Univ. of Newcastle upon Tyne (England))

    1990-02-01

    Epidermal melanocytes (MC) synthesize melanin in response to ultraviolet radiation (UVR). The mechanisms mediating the UV-induced activation of melanogenesis are unknown but since UVR induces turnover of membrane phospholipids generating prostaglandins (PGs) and other products, it is possible that one of these might provide the activating signal. We have examined the effects of prostaglandins (PGs) E1, E2, D2, F2 alpha, and di-acyl glycerol upon the UV-induced responses of cultured human MC and the Cloudman S91 melanoma cell line. The PGs had little effect on unirradiated cells and did not alter the response to UVR in either human MC or S91 melanoma cells. However, a synthetic analogue of di-acyl glycerol, 1-oleyl 2-acetyl glycerol (OAG), caused a significant (P less than 0.0001), dose-related augmentation of melanin content both in human MC (seven-fold) and S91 cells (three-fold). UVR caused a significant augmentation of the OAG-induced melanogenesis of both human MC and S91 cells. Since OAG is known to activate protein kinase C, it was possible that the observed modulation of the UVR signal could be via that pathway. Di-octanoyl glycerol, another di-acyl glycerol, which activates kinase C, caused a small (70%) increase in melanogenesis in MC which was not altered by UVR. However, 12-0 tetradecanoyl phorbol 13-acetate (TPA), a potent activator of protein kinase C, had no significant effect on either basal or UV-induced melanin synthesis in either cell type. These data suggest that the UV-induced signal activating melanogenesis could be mediated by di-acyl glycerol. Furthermore, they imply that the signal is transduced via an alternative, pathway that might be independent of protein kinase C.

  20. EAMJ Dec. Repeatability.indd

    African Journals Online (AJOL)

    2008-12-12

    Dec 12, 2008 ... Results:Kappa values for four-week repeatability for the wheeze and asthma questions were 0.61 ... for logistic, cultural and ethical reasons, to use ... individual with baseline forced expiratory volume in .... period is likely to also include the effects of true ... data, the writing of the manuscript or the decision.

  1. 改良选择性腰骶段脊神经后根部分切断术治疗痉挛性截瘫的初步疗效报告%The preliminary report of modified selective posterior rhizotomy of lumbosacral region for relief of spasticity of lower limbs of spasmodic paraplegia

    Institute of Scientific and Technical Information of China (English)

    于炎冰; 张黎; 徐晓利; 许骏; 任鸿翔; 刘江; 李放

    2009-01-01

    Objective To study the preliminary effectiveness of modified seleetive posterior rhizotomy of lumbosacral region for relief of spasticity of lower limbs of spasmodic paraplegia. Method 21 cases of spasmodic paraplegia patients with spastieity of lower limbs were treated by modified selective posterior rhizotomy of lumbosaeral region from July 2002 to March 2008. Results At follow up evaluation (mean duration :26. 3 months), this study showed that 91% (19/21) eases experienced disappearance or notable regression of spasticity in follow-up duration. The improved motor capacities were found in 71% (15/21) cases. 95% (20/21) eases had better quality of life by follow-up studying. Postoperative complication included dysaesthesias of lower limbs(24% ,5/21), muscle weakness (14% ,3/21), transient uroschesis(5% ,1/21) ,and recurrence of spasticity(24% ,5/21). Conclusions The preliminary study showed that modified selective posterior rhizotomy of lumbosaeral region is an effective and safe microsurgical method for treatment of spastieity of lower limbs in spasmodic paraplegia patients. But its further effectiveness should be evaluated for a longer time.%目的 探讨改良选择性腰骶段脊神经后根部分切断术治疗痉挛性截瘫的初步疗效.方法 回顾分析2002年7月至2008年3月显微手术治疗的21例痉挛性截瘫患者下肢痉挛状态,全部采用改良选择性腰骶部脊神经后根部分切断术.结果 平均随访26.3个月.术后即刻痉挛状态缓解率为100%,随访期间痉挛状态缓解率为91%(19/21),步态功能改善率为71%(15/21),生活质量提高率为95%(20/21).24%(5/21)患者存在随访期间未完全缓解的下肢感觉障碍或异常,肌无力者占14%(3/21),术后发生一过性尿潴留1例(5%).随访期间无永久性二便障碍发生.术后下肢痉挛状态不同程度复发5例(24%),其中2例(10%)回复到术前的严重程度.结论 改良选择性腰骶部脊神经后根部分切断术治疗痉挛性截瘫

  2. Percutaneous radiofrequency rhizotomy and neurovascular decompression of the trigeminal nerve for the treatment of facial pain Rizotomia percutânea por radiofreqüência e a descompressão neurovascular do nervo trigêmeo no tratamento das algias faciais

    Directory of Open Access Journals (Sweden)

    Manoel J. Teixeira

    2006-12-01

    Full Text Available OBJECTIVE: To determine the outcomes of 354 radiofrequency rhizotomies and 21 neurovascular decompressions performed as treatment for 367 facial pain patients (290 idiopathic trigeminal neuralgia, 52 symptomatic trigeminal neuralgia, 16 atypical facial pain, 9 post-herpetic neuralgia. METHOD: Clinical findings and surgery success rate were considered for evaluation. A scale of success rate was determined to classify patients, which considered pain relief and functional/sensorial deficits. RESULTS: Radiofrequency rhizotomy was performed in 273 patients with idiopathic trigeminal neuralgia and in all other patients, except for trigeminal neuropathy; neurovascular decompression was performed in 18 idiopathic trigeminal neuralgia patients; 100% idiopathic trigeminal neuralgia, 96.2% symptomatic trigeminal neuralgia, 37.5% atypical facial pain and 88.9% post-herpetic neuralgia had pain relief. CONCLUSION: Both techniques for idiopathic trigeminal neuralgia are usefull. Radiofrequency rhizotomy was also efficient to treat symptomatic facial pain, and post-herpetic facial pain, but is not a good technique for atypical facial pain.OBJETIVO: Determinar eficácia e achados pós-operatórios após 354 rizotomias por radiofreqüência e 21 descompressões neurovasculares como tratamento de 367 pacientes com dor facial (290 neuralgia idiopática do trigêmeo, 52 neuralgia sintomática do trigêmeo, 16 dor facial atípica, 9 neuralgia pós-herpética. MÉTODO: Achados clínicos e taxa de sucesso das cirurgias foram considerados para a avaliação. Uma escala avaliando alívio da dor e complicações sensoriais e funcionais foi utilizada para classificar os pacientes. RESULTADOS: A rizotomia por radiofreqüência foi realizada em 273 pacientes com neuralgia idiopática do trigêmeo e em todos os outros pacientes, exceto neuropatia trigeminal; descompressão neurovascular foi realizada em 18 pacientes com neuralgia idiopática do trigêmeo; 100% dos pacientes

  3. Blood-retinal barrier glycerol permeability in diabetic macular edema and healthy eyes: estimations from macular volume changes after peroral glycerol

    DEFF Research Database (Denmark)

    Thornit, Dorte Nellemann; Vinten, Carl Martin; Sander, Birgit

    2010-01-01

    PURPOSE: To compare the changes in macular volume (MV) between healthy subjects and patients with diabetic macular edema (DME) after an osmotic load and to determine the glycerol permeability (P(gly)) of the blood-retinal barrier (BRB). METHODS: In this unmasked study, 13 patients with DME and 5...... model of glycerol and osmotic water movements across the BRB was constructed to estimate P(gly). RESULTS: Median MV decreased from 7.30 mm(3) (range, 6.68-7.35) to the maximum median DeltaMV of -0.30 mm(3) (25%-75% quartile: -0.34 to -0.25) in the healthy volunteers and from 7.97 mm(3) (range, 6...

  4. A Simple and Efficient Process for Large Scale Glycerol Oligomerization by Microwave Irradiation

    Directory of Open Access Journals (Sweden)

    Rémi Nguyen

    2017-04-01

    Full Text Available Herein, an optimized method for 100 g scale synthesis of glycerol oligomers using a microwave multimode source and the low priced K2CO3 as catalyst is reported. This method allows the complete conversion of glycerol to its oligomers in only 30 min, yielding molecular weights up to 1000 g mol−1. Furthermore, a simple iterative purification process, involving the precipitation of the crude product in acetone and methanol, affords a final product composed of larger oligomers with a narrow dispersity (D < 1.5.

  5. Some considerations on the transport properties of water-glycerol suspensions

    Science.gov (United States)

    Mallamace, Francesco; Corsaro, Carmelo; Mallamace, Domenico; Vasi, Sebastiano; Vasi, Cirino; Stanley, H. Eugene

    2016-01-01

    We study the self-diffusion coefficient and viscosity of a water-glycerol mixture for several glycerol molar fractions as a function of temperature well inside the metastable supercooled regime. We perform NMR experiments and verify that the system has at different concentration a fragile-to-strong crossover accompanied by the violation of the Stokes-Einstein relation. We observe that the crossover temperature depends on the water amount. Studying the fractional representation of the Stokes-Einstein relation, we find that in these systems dynamical arrest does not exhibit criticality and the transport parameters have a universal behavior.

  6. High-pressure acoustic properties of glycerol studied by Brillouin spectroscopy

    Science.gov (United States)

    Jeong, Min-Seok; Ko, Jae-Hyeon; Ko, Young Ho; Kim, Kwang Joo

    2015-12-01

    Acoustic properties of glycerol was investigated in a wide pressure range from ambient pressure to 30.9 GPa by using a multi-pass Fabry-Perot interferometer and a diamond anvil cell. Pressure dependences of the sound velocity and the Brillouin linewidth showed substantial changes at low pressures below ~4 GPa. This was attributed to the coupling between the main structural relaxation process and the longitudinal acoustic waves. The pressure dependence of the refractive index and the density of glycerol could be obtained by using two scattering geometries and the Lorentz-Lorenz relation.

  7. High-pressure acoustic properties of glycerol studied by Brillouin spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Min-Seok [Department of Physics, Hallym University, Chuncheon, Gangwondo 200-702 (Korea, Republic of); Ko, Jae-Hyeon, E-mail: hwangko@hallym.ac.kr [Department of Physics, Hallym University, Chuncheon, Gangwondo 200-702 (Korea, Republic of); Ko, Young Ho; Kim, Kwang Joo [Agency for Defense Development, 4-2-2, P.O. Box 35, Yuseong, Daejeon 305-600 (Korea, Republic of)

    2015-12-01

    Acoustic properties of glycerol was investigated in a wide pressure range from ambient pressure to 30.9 GPa by using a multi-pass Fabry–Perot interferometer and a diamond anvil cell. Pressure dependences of the sound velocity and the Brillouin linewidth showed substantial changes at low pressures below ~4 GPa. This was attributed to the coupling between the main structural relaxation process and the longitudinal acoustic waves. The pressure dependence of the refractive index and the density of glycerol could be obtained by using two scattering geometries and the Lorentz–Lorenz relation.

  8. A physicochemical study of sugar palm (Arenga Pinnata) starch films plasticized by glycerol and sorbitol

    Science.gov (United States)

    Poeloengasih, Crescentiana D.; Pranoto, Yudi; Hayati, Septi Nur; Hernawan, Rosyida, Vita T.; Prasetyo, Dwi J.; Jatmiko, Tri H.; Apriyana, Wuri; Suwanto, Andri

    2016-02-01

    The present work explores the physicochemical characteristics of sugar palm starch film for a potential hard capsule purpose. Sugar palm (Arenga pinnata) starch films were plasticized with glycerol or sorbitol in various concentrations (30% up to 50% w/w starch). Their effects on physicochemical properties of the films were investigated. The results showed that sugar palm starch was successfully developed as the main material of film using casting method. Incorporation of both glycerol or sorbitol affected the properties of films in different ways. It was found that thickness and solubility increased as plasticizer concentration increased, whereas retraction ratio, swelling degree and swelling thickness decreased with the increased plasticizer concentration.

  9. Glycerol Containing Triacetylborate Mediated Syntheses of Novel 2-Heterostyryl Benzimidazole Derivatives: A Green Approach

    Directory of Open Access Journals (Sweden)

    Ashok Kumar Taduri

    2014-01-01

    Full Text Available A very simple, mild, efficient, and novel green methodology has been developed for the syntheses of some 2-hetero/styryl-benzimidazoles. Title compounds were synthesized by the condensation of o-phenylenediamine with cinnamic acids at 150–180°C for 5-6 h using glycerol containing triacetylborate (10–20 mol% as the reaction medium. In an alternative approach, condensation of 2-methylbenzimidazole derivatives with aromatic aldehydes was done using glycerol containing triacetylborate (10–20 mol% as the reaction medium.

  10. 1,3-Propanediol production from crude glycerol from Jatropha biodiesel process.

    Science.gov (United States)

    Hiremath, Anand; Kannabiran, Mithra; Rangaswamy, Vidhya

    2011-01-31

    The present report describes production of 1,3-propanediol by Klebsiella pneumoniae ATCC 15380 from crude glycerol from jatropha biodiesel process. Optimization resulted in a yield of up to 56g/L of 1,3-propanediol. A conversion rate of 0.85mol 1,3-propanediol/mol of glycerol has been obtained. Downstream processing to isolate 1,3-propanediol from the fermentation broth resulted in 99.7% pure product with a recovery of 34%. The pure 1,3-propanediol was polymerized with terephthalic acid successfully to yield polytrimethylene terephthalate.

  11. The direct effect of incretin hormones on glucose and glycerol metabolism and hemodynamics

    DEFF Research Database (Denmark)

    Karstoft, Kristian; Mortensen, Stefan; Knudsen, Sine H;

    2015-01-01

    The objective of this study was to assess the insulin-independent effects of incretin hormones on glucose and glycerol metabolism and hemodynamics under eu- and hyperglycemic conditions. Young, healthy males (n=10) underwent three trials in a randomized, controlled, cross-over study. Each trial...... consisted of a 2-stage (eu- and hyperglycemia) pancreatic clamp (using somatostatin to prevent endogenous insulin secretion). Glucose and lipid metabolism were measured via infusion of stable glucose and glycerol isotopic tracers. Hemodynamic variables (femoral, brachial and common carotid artery blood flow...... a higher femoral blood flow during hyperglycemia in GIP (vs. CON and GLP-1, Pmetabolism or hemodynamics during euglycemia. On contrary, during...

  12. Selective Oxidation of Raw Glycerol Using Supported AuPd Nanoparticles

    Directory of Open Access Journals (Sweden)

    Carine E. Chan-Thaw

    2015-02-01

    Full Text Available Bimetallic AuPd supported on different carbonaceous materials and TiO2 was tested in the liquid phase oxidation of commercial grade and raw glycerol. The latter was directly obtained from the base-catalyzed transesterification of edible rapeseed oil using KOH. The best catalytic results were obtained using activated carbon and nitrogen-functionalized carbon nanofibers as supports. In fact, the catalysts were more active using pure glycerol instead of the one obtained from rapeseed, where strong deactivation phenomena were present. Fourier transform infrared (FT-IR and TEM were utilized to investigate the possible reasons for the observed loss of activity.

  13. Techno-economic risk analysis of glycerol biorefinery concepts against market price fluctuation

    DEFF Research Database (Denmark)

    Gargalo, Carina L.; Cheali, Peam; Gernaey, Krist

    . The high-value added bio-products boost profitability, the high-volume fuel helps meet national energy targets, and the power production cuts costs and dodges greenhouse-gas emissions [1] [2] [3]. The increasing amount of biodiesel production worldwide (e.g. from vegetable oils, palm oil, animal fats......, certain algae species also accumulate large amounts of glycerol and could become another possible source due to the recent development of algae biomass as feedstock for biofuel production [10]. In this contribution, we study and critically analyze a number of glycerol biorefinery concepts developed...

  14. Utilization of molasses and akalona hydrolyzate for continuous glycerol production in a packed bed bioreactor

    Energy Technology Data Exchange (ETDEWEB)

    Mostafa, N.A.; Magdy, Yehia H. [El-Minia Univ., Chemical Engineering Dept., El-Minia (Egypt)

    1998-12-31

    Continuous glycerol fermentation of a by-product cane sugar molasses and wheat milling residues (akalona) was studied using sulfite as a combining agent with the aldehyde. Thus, a local yeast Saccharomyces cerevisiae could be used under anaerobic conditions instead of glycerol production microorganisms (osmophilic yeast`s) which need essentially aerobic conditions. The processes were performed in a vertical packed-bed reactor with yeast cells immobilized in agar gel. The influence of the dilution rate on the performance of the bioreactor was studied. The substrate and product concentration profiles along the column height are presented. A kinetic study has been used to identify the rate controlling step(s). (Author)

  15. Comparative study of cryopreserved bone tissue and tissue preserved in a 98% glycerol solution

    OpenAIRE

    GIOVANI, Arlete Mazzini Miranda; Croci, Alberto Tesconi; Oliveira,Cláudia Regina GCM; Filippi,Renée Zon; Santos, Luiz Augusto U.; Maragni,Graziela G; Albhy,Thays Moreira

    2006-01-01

    OBJECTIVE: To compare the bone graft cryopreservation method (at -80ºC) with a preservation method using a 98% glycerol solution at room temperature (10ºC-35ºC), by testing the antibacterial and fungal effects of 98% glycerol and comparatively analyzing the observed histological changes resulting from the use of both methods. METHOD: This study was of 30 samples of trabecular bone tissue from 10 patients undergoing total hip arthroplasty. Each femoral head provided 3 samples that were randomi...

  16. Caffeic acid and glycerol are constituents of the suberin layers in green cotton fibres.

    Science.gov (United States)

    Schmutz, A; Jenny, T; Amrhein, N; Ryser, U

    1993-03-01

    The fibres of the green-lint mutant (Lg) of cotton (Gossypium hirsutum L.) are suberized and contain a large proportion of wax. The unidentified components of the wax were separated into a colourless fluorescent fraction and a yellow pigmented fraction. Using ultraviolet spectroscopy and nuclear-magneticresonance ((1)H-NMR) spectroscopy, esterified trans-caffeic acid was identified as the only phenolic component in the colourless fraction. This fraction was further purified and was shown to contain caffeic acid esterified to fatty acids (mainly ω-hydroxy fatty acids), and glycerol in molar ratios of 4∶5∶5. When 2-aminoindan-2-phosphonic acid (AIP), an inhibitor of phenylalanine ammonia-lyase (EC 4. 3. 1. 5.) was added to ovules cultured in vitro, at the beginning of secondary wall formation, the fibres remained white and the colourless caffeic-acid derivative and the yellow compounds could no longer be detected by ultraviolet spectroscopy. Fibres grown in the presence of AIP were also examined in the electron microscope. Secondary cell walls were present in the treated fibres, but the electron-opaque suberin layers were replaced by apparently empty spaces. This result indicates that cinnamic-acid derivatives are covalently linked to suberin and have a structural role within the polymer or are involved in anchoring the polymer to the cellulosic secondary wall. Purified cell walls of green cotton fibres contained about 1% (of the dry weight) of bound glycerol, 0.9% of the glycerol being extractable with the wax fraction and 0.1% remaining in the cell-wall residue. The corresponding values for white fibres were 0.03% (total), 0.02% (wax), and 0.01% (cell-wall residue). Fibres synthesizing their secondary walls in the presence of AIP contained about normal amounts of bound glycerol in the wax fraction, but glycerol accumulation in the cell-wall residue was inhibited by about 95%. These observations indicate that glycerol is an important constituent of cotton

  17. One-step selective synthesis of branched 1-O-alkyl-glycerol/diglycerol monoethers by catalytic reductive alkylation of ketones

    Institute of Scientific and Technical Information of China (English)

    DAYOUB; Wissam; LEMAIRE; Marc

    2010-01-01

    Branched 1-O-alkyl glycerol and diglycerol monoethers were obtained in good yields and high selectivity by a straightforward catalytic reductive alkylation of glycerol with relevant ketones in the presence of 0.5 mol% of Pd/C under 10 bar of hydrogen pressure using a Brφnsted acid as the co-catalyst.

  18. Synthesis of bio-additives: transesterification of ethyl acetate with glycerol using homogeneous or heterogeneous acid catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Meireles, Bruno A.; Pereira, Vera Lucia P., E-mail: patrocinio@nppn.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Centro de Ciencias da Saude. Nucleo de Pesquisas de Produtos Naturais

    2013-01-15

    A new catalytic route with potential practical interest to sustainable production of bioadditives from glycerol is described. Ethyl acetate was transesterified with glycerol, in the ratio glycerol:EtOAc 1:10, at 25 or 90 deg C using 0.1 equiv.of H{sub 2}SO{sub 4} or TsOH, as homogeneous catalysts. H{sub 2}SO{sub 4} led to the total glycerol consumption in 2 h. In the equilibrium, attained in 9 h, 100% yield of a diacetin:triacetin (55:45) mixture was formed. Using Amberlyst Registered-Sign 15 dry and Amberlyst Registered-Sign 16 wet in 1:30 glycerol:EtOAc ratio and reflux at 90 Degree-Sign C the total glycerol consumption was achieved in 2 and 10h, respectively. The lower reactivity of Amberlyst-16 wet was explained in terms of deactivation of acid sites and decrease in glycerol diffusion to the inner resin pores, both factors caused by adsorbed water. The kinetics of glycerol transformation and product distribution in the equilibrium in relation to the H{sub 2}SO{sub 4}, Amberlyst-15 (dry) and Amberlyst-16 (wet) catalyzed reactions were measured. (author)

  19. CHANGES OF GLYCEROL CONTENT IN DIAPAUSE LARVAEOF THE ORANGE WHEAT BLOSSOM MIDGE, SITODIPLOSIS MOSELLANA (GEHIN) IN VARIOUS SEASONS

    Institute of Scientific and Technical Information of China (English)

    Jun-xiangWu; FengYuan

    2004-01-01

    The glycerol contents in diapause larvae of the orange wheat blossom midge, Sitodiplosis mosellana (Gehin), collected from various seasons, were measured. The results showed that there was less glycerol content in larvae during living on the wheat head. Content of glycerol began to increase significantly when the larvae left the wheat head and entered the soil. A change trend of upper- lower- upper- lower in larvae glycerol contents during diapause in soil was observed from June to April of next year. More glycerol could be examined in larvae collected in summer and winter than in spring and autumn. There was not more glycerol in cocooned larvae than that in non-cocooned larvae during various seasons from the point of statistics. Comparing the glycerol content of larvae being diapause in the first year with that of larvae in the second year, there was yet no obvious difference when larvae were collected in the same season belonged to different years. Therefore, it is shown that the content of glycerol in larvae of the wheat midge in diapause is affected mainly by the seasons or diapause intensity.

  20. Gpd1 and Gpd2 fine-tuning for sustainable reduction of glycerol formation in Saccharomyces cerevisiae

    NARCIS (Netherlands)

    Hubmann, Georg; Guillouet, Stephane; Nevoigt, Elke

    2011-01-01

    Gpd1 and Gpd2 are the two isoforms of glycerol 3-phosphate dehydrogenase (GPDH), which is the rate-controlling enzyme of glycerol formation in Saccharomyces cerevisiae. The two isoenzymes play crucial roles in osmoregulation and redox balancing. Past approaches to increase ethanol yield at the cost

  1. Application of glycerol as a foliar spray activates the defence response and enhances disease resistance of Theobroma cacao.

    Science.gov (United States)

    Zhang, Yufan; Smith, Philip; Maximova, Siela N; Guiltinan, Mark J

    2015-01-01

    Previous work has implicated glycerol-3-phosphate (G3P) as a mobile inducer of systemic immunity in plants. We tested the hypothesis that the exogenous application of glycerol as a foliar spray might enhance the disease resistance of Theobroma cacao through the modulation of endogenous G3P levels. We found that exogenous application of glycerol to cacao leaves over a period of 4 days increased the endogenous level of G3P and decreased the level of oleic acid (18:1). Reactive oxygen species (ROS) were produced (a marker of defence activation) and the expression of many pathogenesis-related genes was induced. Notably, the effects of glycerol application on G3P and 18:1 fatty acid content, and gene expression levels, in cacao leaves were dosage dependent. A 100 mm glycerol spray application was sufficient to stimulate the defence response without causing any observable damage, and resulted in a significantly decreased lesion formation by the cacao pathogen Phytophthora capsici; however, a 500 mm glycerol treatment led to chlorosis and cell death. The effects of glycerol treatment on the level of 18:1 and ROS were constrained to the locally treated leaves without affecting distal tissues. The mechanism of the glycerol-mediated defence response in cacao and its potential use as part of a sustainable farming system are discussed. © 2014 BSPP AND JOHN WILEY & SONS LTD.

  2. Lumbar laminoplasty for selective posterior rhizotomy in children%腰椎管成形在儿童选择性脊神经后根切断术中的应用及临床转归

    Institute of Scientific and Technical Information of China (English)

    白金柱; 洪毅; 王一昕; 张军卫; 唐和虎; 姜树东; 李想; 王方永

    2012-01-01

    [Objective] To explore the application and clinical outcome of lumbar laminoplasty for selective posterior rhizotomy (SPR) in children. [Methods] Sixty - eight vertebra of cerebral pulsy in 36 cases of SRR were analyzed retrospectively from July 2007 to December 2009 , with male 23 cases, female 13 cases. Mean age wa9 6.5 years at the operation. Lumbar laminoplasty methods were spinous process, lamina and supraspinal ligament complex were taken out as whole piece and widen by split, and were replanted in situ , fixed with silk, reconstructed for supraspinal ligament continuity after SPR. All patients were followed up with symptoms, lumbar X - ray, CT or MRI, and were evaluated for the spinal canal morphology, lumbar spinal stability, replanted lamina bone fusion and outcome. [ Results ] The average follow -up period was 32 months. Postoperative patients showed no back pain. The muscle tone of lower extremity decreased postopratively, the difference was statistically significant (P<0.05) . The lumbar X-ray in 19 cases showed no obvious abnormity, in 16 cases showed good spinal alignment, but visible lumbar postoperative change. Twelve cases of lumbar X - ray of flexion and extention phase showed no change between preoperalion and follow - up. Lumbar CT in all cases showed the spinal canal morphologymainly integrity, with no stenosis and compression. Fusion rate was 85. 3% , absorption rate was 61. 8% , the relationship between the two index showed negative correlation statistically. Lumbar MRI in 2 cases showed lamina partial absent at local section of surgery, no dural compression , and continuous supraspinal ligament [ Conclusion ] Lumbar laminoplasty with replantation of spinous process, lamina and supraspinal ligament complex could reconstruct the lumbar spinal stability in SPR. Replanted lamina absorbing phenomenon were observed after 2 years of follow - up, but there was no significantly influence to the development of the lumbar spine. Residual lamina and

  3. Observation of therapeutic efficacy of lumbar selective posterior rhizotomy for cerebral palsy-associated lower limb spasm%腰段选择性脊神经后根切断术治疗脑瘫性下肢痉挛99例疗效观察

    Institute of Scientific and Technical Information of China (English)

    王健; 尹靖宇; 郑炳铃; 徐涛; 陈熙慧

    2012-01-01

    目的 探讨腰段选择性脊神经后根切断术(lumbar selective posterior rhizotomy,L-SPR)治疗脑瘫性下肢痉挛的临床疗效.方法 回顾性分析99例脑瘫性下肢痉挛病人的临床资料,均施行L-SPR手术,通过观察下肢肌张力和Holden步行功能分级的变化评估临床疗效.结果 随访99例,时间3~88个月.术后肌张力及Holden步行功能分级同术前相比,差异具有统计学意义(均P <0.05).术后畸形完全消失26例,症状减轻49例,不变24例.近期并发症为一过性头痛23例,切口愈合不良5例,一过性痉挛加重20例,锥体外系症状加重6例;远期并发症为腰部乏力2例,痉挛复发3例,均治疗后改善.结论 L-SPR手术能有效解除脑瘫性下肢痉挛,改善运动功能.%Objective To explore the clinical efficacy of lumbar selective posterior rhizotomy (L-SPR) for cerebral palsy patients with spasticity of lower limbs. Methods Clinical data of 99 cerebral palsy patients with spasticity of lower limbs were analyzed retrospectively, who were treated by L-SPR. The clinical efficacy was evaluated by observing the changes of muscle tension of low limbs and Holden functional ambulation classification. Results All the patients were followed up for 3 to 88 months, there were significantly differences in muscle tension and Holden functional ambulation classification between before and after surgery (all P < 0.05). Deformity disappeared in 26 patients, alleviation of symptom in 49 and no alleviation in 24. Recent complications such as transient headache occurred in 23 patients, poor incision healing in 5, transient spasm aggravation in 20 and aggravation of extrapyramidal symptoms in 6. Long-term complications such as waist weakness occurred in 2 patients and relapse of spasm in 3. All the symptoms were improved after treatment. Conclusions L-SPR is effective to relieve spasticity of lower limbs and improve motor function in patients with cerebral palsy.

  4. 脑瘫儿童选择性脊神经后根切断术术前爬行能力与术后下肢功能改善的关联分析%Predictive value of crawling ability for prognostication of the functional amelioration of children with cerebral palsy after selective posterior rhizotomy

    Institute of Scientific and Technical Information of China (English)

    易斌; 徐林; 洪毅; 俞兴; 王兵; 郑大滨

    2001-01-01

    Objective: To investigate functional changes of lower extremities after selective posterior rhizotomy, and to evaluate the value of crawling ability as a predictor of walking postoperatively. Method: To observe the function of lower limbs with quantitative functional measurement, and analyze the relation between walk ability after SPR and preoperative crawling stage. Result: (1)Muscle tone was significantly decreased, and the development of function of lower limbs was obvious. (2) The achievement was progressing in 1-year and 2-year follow-up groups. ( 3 ) The ability of crawling was closely related with walk ability after SPR. Conclusion:SPR decreases spasticity and increases lower extremity range of motion in children with cerebral palsy and appears to be associated with functional improvements. The ability of crawling is a predictive reference of ability to walk after selective posterior rhizotomy.%目的:分析术前爬行能力与术后下肢功能,特别是独立行走能力的关系。方法:以量化功能的方式评估选择性脊神经后根切断术(SPR)后下肢功能,将爬行功能分为A-D 4个等级,同时将下肢功能分别量化,观察各级患儿手术前、后的功能变化,并统计分析手术前、后功能差异。结果:脑瘫患者SPR术后肌张力明显降低,下肢各项功能显著改善;术前爬行能力良好的患儿术后下肢各项功能及独立行走与爬行能力差的患者有显著性差异。结论:术前评估爬行能力对判断手术预后具有参考价值。

  5. Efetividade da rizotomia facetária por radiofrequência na lombalgia mecânica crônica Efectividad de la rizotomía facetaria en lumbago mecánico Effectiveness of radiofrequency facet rhizotomy in the treatment of mechanical back pain

    Directory of Open Access Journals (Sweden)

    Lourimar Octaviano de Tolêdo

    2011-01-01

    Full Text Available OBJETIVO: Avaliar a efetividade da rizotomia facetária lombar por radiofreqüência no tratamento da dor lombar mecânica. MÉTODOS: Estudo prospectivo de 23 pacientes tratados com rizotomia por radiofrequência devido à dor lombar mecânica. O registro da intensidade da dor foi medido através de pontuação pela escala visual analógica (EVA e o número de analgésicos administrado a cada paciente no pré-operatório e nos controles de 3, 6 e 12 meses de pós-operatórios. RESULTADOS: Foi observado um declínio significativo da intensidade da dor (p OBJETIVO: Evaluar la efectividad de la rizotomía por radiofrecuencia facetaria lumbar en el tratamiento del lumbago mecánico. MÉTODOS: Estudio prospectivo de 23 pacientes tratados con rizotomía por radiofrecuencia en lumbago mecánico. El registro de la intensidad del dolor se midió por la puntuación de la escala analógica visual (VAS y el número de analgésicos administrados a cada paciente antes de la operación, y 3, 6 y 12 meses después de la intervención. RESULTADOS: Se observó una disminución significativa en la intensidad del dolor (p OBJECTIVE: To evaluate the effectiveness of radiofrequency lumbar facet rhizotomy in the treatment of mechanical low back pain. METHODS: Prospective study of 23 patients treated with radiofrequency rhizotomy in mechanical low back pain. The pain intensity was measured by the visual analog scale (VAS and the number of analgesics administered for each patient preoperatively and 3, 6 and 12 months postoperatively. RESULTS: We observed a significant decline in pain intensity (p<0.0001 in patients. CONCLUSIONS: In the series of patients assessed the treatment was effective in relieving symptoms of mechanical low back pain and the use of analgesics after the procedure was lower.

  6. Directionality switchable gain stabilized linear repeater

    Science.gov (United States)

    Ota, Takayuki; Ohmachi, Tadashi; Aida, Kazuo

    2004-10-01

    We propose a new approach to realize a bidirectional linear repeater suitable for future optical internet networks and fault location in repeater chain with OTDR. The proposed approach is the linear repeater of simple configuration whose directionality is rearranged dynamically by electrical control signal. The repeater is composed of a magneto-optical switch, a circulator, a dynamically gain stabilized unidirectional EDFA, and control circuits. The repeater directionality is rearranged as fast as 0.1ms by an electrical control pulse. It is experimentally confirmed that OTDR with the directionality switchable repeater is feasible for repeater chain. The detailed design and performance of the repeater are also discussed, including the multi-pass interference (MPI) which may arise in the proposed repeater, the effect of the MPI on SNR degradation of the repeater chain and the feed-forward EDFA gain control circuit.

  7. Evaluation of glycerol as an osmotic agent for continuous ambulatory peritoneal dialysis in end-stage renal failure.

    Science.gov (United States)

    Heaton, A; Ward, M K; Johnston, D G; Alberti, K G; Kerr, D N

    1986-01-01

    Six patients established on continuous ambulatory peritoneal dialysis entered a trial of treatment with dialysis fluid containing glycerol instead of glucose as the osmotic agent in an attempt to decrease the energy load. They were observed for a further 6 months after reconversion to glucose-based dialysis. During the 6 month control period fluid balance was achieved mainly with a solution containing 76 mmol of glucose/1. Fluid balance was maintained during the 6 month period of treatment with glycerol only by the increased use of solutions containing a high concentration of glycerol (152 mmol/l and 272 mmol/l). Thus the energy value of the absorbed osmotic agent did not differ at a mean of 1607 kJ (384 kcal)/day using glycerol and 1669 kJ (399 kcal)/day using glucose as the osmotic agent. In five subjects, fasting and peak blood glycerol levels did not change over the 6 months, but one subject, who accumulated glycerol, developed symptoms of hyperosmolality after 2 months and glycerol therapy was discontinued. In a further subject glycerol-based dialysis was terminated at 3 months when increasing angina was reported. Mean fasting plasma triglyceride concentrations were 50% higher during the 6 months on glycerol (3.12 +/- 1.12 mmol/l) than on glucose (2.19 +/- 0.97 mmol/l) (P less than 0.05). There was a small rise in very low density lipoprotein-cholesterol concentrations with glycerol dialysis but total cholesterol levels were unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)

  8. Effect of water structure on gelation of agar in glycerol solutions and phase diagram of agar organogels.

    Science.gov (United States)

    Boral, Shilpi; Bohidar, H B

    2012-06-21

    A comprehensive study of hydration of polyanionic agar molecules in its solution and gel phase in glycerol-water binary solvent is reported. Raman spectroscopy results predict differential water structure arrangement for glycerol-water binary solvent, 0.02% (w/v) agar in glycerol solution and 0.3% (w/v) agar organogel. The 3200 cm(-1) Raman band pertaining to ice-like structure of water was found to increase in gel phase alike in glycerol-water solvent while it decreased in agar solutions with increase in glycerol concentration. In contrast, the partially structured water corresponding to the component 3310 cm(-1) of Raman spectra increased in agar solution, and decreased in gel phase similar to glycerol-water solvent case. We have explained these observations based on a simple model where the available oxygen to hydrogen atom ratio in a given solvent-polymer system uniquely defines hydration in solution and gel phases. The gelation concentration was found to increase from 0.18 (for water) to 0.22% (w/v) (50% v/v glycerol solution) as the glycerol concentration was raised. Correspondingly, the gelation temperature, T(g), showed a decline from 40 to 20 °C, and the gel melting temperature, T(m), revealed a reduction from 81 to 65 °C in the same glycerol concentration regime. Two distinctive features are evident here: (i) presence of glycerol as a cosolvent does not favor the gelation of agar as compared to water and (ii) agar organogels are softer than their hydrogels. A unique 3D phase diagram for the agar organogel is proposed. Circular dichroism data confirmed that the agar molecules retained their biological activity in these solvents. Thus, it is shown that thermo-mechanical properties of these organogels could be systematically tuned and adapted as per application requirement.

  9. Measurement-based quantum repeaters

    CERN Document Server

    Zwerger, M; Briegel, H J

    2012-01-01

    We introduce measurement-based quantum repeaters, where small-scale measurement-based quantum processors are used to perform entanglement purification and entanglement swapping in a long-range quantum communication protocol. In the scheme, pre-prepared entangled states stored at intermediate repeater stations are coupled with incoming photons by simple Bell-measurements, without the need of performing additional quantum gates or measurements. We show how to construct the required resource states, and how to minimize their size. We analyze the performance of the scheme under noise and imperfections, with focus on small-scale implementations involving entangled states of few qubits. We find measurement-based purification protocols with significantly improved noise thresholds. Furthermore we show that already resource states of small size suffice to significantly increase the maximal communication distance. We also discuss possible advantages of our scheme for different set-ups.

  10. A Repeating Fast Radio Burst

    CERN Document Server

    Spitler, L G; Hessels, J W T; Bogdanov, S; Brazier, A; Camilo, F; Chatterjee, S; Cordes, J M; Crawford, F; Deneva, J; Ferdman, R D; Freire, P C C; Kaspi, V M; Lazarus, P; Lynch, R; Madsen, E C; McLaughlin, M A; Patel, C; Ransom, S M; Seymour, A; Stairs, I H; Stappers, B W; van Leeuwen, J; Zhu, W W

    2016-01-01

    Fast Radio Bursts are millisecond-duration astronomical radio pulses of unknown physical origin that appear to come from extragalactic distances. Previous follow-up observations have failed to find additional bursts at the same dispersion measures (i.e. integrated column density of free electrons between source and telescope) and sky position as the original detections. The apparent non-repeating nature of the fast radio bursts has led several authors to hypothesise that they originate in cataclysmic astrophysical events. Here we report the detection of ten additional bursts from the direction of FRB121102, using the 305-m Arecibo telescope. These new bursts have dispersion measures and sky positions consistent with the original burst. This unambiguously identifies FRB121102 as repeating and demonstrates that its source survives the energetic events that cause the bursts. Additionally, the bursts from FRB121102 show a wide range of spectral shapes that appear to be predominantly intrinsic to the source and wh...

  11. Repeatability of Harris Corner Detector

    Institute of Scientific and Technical Information of China (English)

    HU Lili

    2003-01-01

    Interest point detectors are commonly employed to reduce the amount of data to be processed. The ideal interest point detector would robustly select those features which are most appropriate or salient for the application and data at hand. This paper shows that interest points are geometrically stable under different transformations.This property makes interest points very successful in the context of image matching. To measure this property quantatively, we introduce a evaluation criterion: repeatability rate.

  12. Theoretical study on the role of surface basicity and Lewis acidity on the etherification of glycerol over alkaline earth metal oxides

    NARCIS (Netherlands)

    Calatayud, M.; Ruppert, A.M.|info:eu-repo/dai/nl/314003398; Weckhuysen, B.M.|info:eu-repo/dai/nl/285484397

    2009-01-01

    Alkaline earth metal oxides (MO) are catalytically active in the etherification of glycerol. Density Functional Theory (DFT) calculations have been used to examine the reactivity of glycerol with MO surfaces with M=Mg, Ca, Sr or Ba. More specifically, the optimum glycerol adsorption mode and the str

  13. The effect of sterol structure on the permeability of lipomes to glucose, glycerol and Rb+

    NARCIS (Netherlands)

    Demel, R.A.; Bruckdorfer, K.R.; Deenen, L.L.M. van

    1972-01-01

    1. 1. The effect of 3β-, 3α-hydroxysterol and ketosteroids on the permeability properties of (egg lecithin) liposomes towards glucose, glycerol and Rb+ has been studied. 2. 2. The 3β-hydroxysterols, cholesterol, cholestanol, lathosterol, 7-dehydrocholesterol and B-norcholesterol affect the most pro

  14. Regulation of the metabolism of methanol, dihydroxyacetone and glycerol in the yeast Hansenula polymorpha.

    NARCIS (Netherlands)

    Koning, Willem de

    1989-01-01

    ln recent years there has been an increasing interest in the possible application of microorganisms for the production of fine chemicals. [...] This thesis reports the results of studies in which various physiological and biochemical aspects of dihydroryacetone (DHA) and glycerol synthesis and utili

  15. Effect of inulin and glycerol supplementation on physicochemical properties of probiotic frozen yogurt.

    Science.gov (United States)

    Muzammil, Hafiz Shehzad; Rasco, Barbara; Sablani, Shyam

    2017-01-01

    The present study was designed to investigate the effects of inulin and glycerol supplementation on physicochemical properties of probiotic frozen yogurt. Frozen yogurt was prepared with different types of probiotic (Lactobacillus acidophilus and Bifidobacterium lactis) along with yogurt starter culture (Streptococcus thermophilus and Lactobacillus bulgaricus). The frozen yogurt mixture was supplemented with inulin (2%, 4%, and 6%) and glycerol (1%, 2%, 3%, and 4%). The results showed that inulin 4% and 6% supplementation increased the overrun by 3% and 5% and the glass transition temperature by 3.3% and 2.8%, and decreased the hardness by 7% and 11%, respectively. Inulin supplementation did not have a significant effect on ice crystal size (p > 0.05). Glycerol supplementation increased the stickiness from 2.4% to 18.7%, and decreased the hardness from 8.0% to 14.5% and the glass transition temperature from 2.4% to 34.5%, respectively. Glycerol supplementation did not have a significant effect on overrun or melting rate (p > 0.05).

  16. Glycerol production by Oenococcus oeni during sequential and simultaneous cultures with wine yeast strains.

    Science.gov (United States)

    Ale, Cesar E; Farías, Marta E; Strasser de Saad, Ana M; Pasteris, Sergio E

    2014-07-01

    Growth and fermentation patterns of Saccharomyces cerevisiae, Kloeckera apiculata, and Oenococcus oeni strains cultured in grape juice medium were studied. In pure, sequential and simultaneous cultures, the strains reached the stationary growth phase between 2 and 3 days. Pure and mixed K. apiculata and S. cerevisiae cultures used mainly glucose, producing ethanol, organic acids, and 4.0 and 0.1 mM glycerol, respectively. In sequential cultures, O. oeni achieved about 1 log unit at 3 days using mainly fructose and L-malic acid. Highest sugars consumption was detected in K. apiculata supernatants, lactic acid being the major end-product. 8.0 mM glycerol was found in 6-day culture supernatants. In simultaneous cultures, total sugars and L-malic acid were used at 3 days and 98% of ethanol and glycerol were detected. This study represents the first report of the population dynamics and metabolic behavior of yeasts and O. oeni in sequential and simultaneous cultures and contributes to the selection of indigenous strains to design starter cultures for winemaking, also considering the inclusion of K. apiculata. The sequential inoculation of yeasts and O. oeni would enhance glycerol production, which confers desirable organoleptic characteristics to wines, while organic acids levels would not affect their sensory profile.

  17. Optimizing the Acid Catalyzed Synthesis of Hyperbranched Poly(Glycerol-diacids) Oligomers

    Science.gov (United States)

    Oligomeric pre-polymers were synthesized by the acid-catalyzed condensation of glycerol with succinic acid, glutaric acid and azelaic acid in dimethylsulfoxide (DMSO) or dimethylformamide (DMF). The prepolymers were obtained, on average in 84% yield, and were characterized by proton NMR, MALDI-TOF ...

  18. Controlling sulfidic tailings oxidation with surface application of crude glycerol : column experiments

    Energy Technology Data Exchange (ETDEWEB)

    Behrooz, M.; Borden, R.C. [North Carolina State Univ., Raleigh, NC (United States). Dept. of Civil, Construction and Environmental Engineering

    2010-07-01

    In this study, crude glycerol was used to control acid mine drainage (AMD) production in sulfidic tailings samples obtained from the Ore Knob tailings pile in Ash County, North Carolina (NC). AMD is produced when mining activities expose sulfidic materials to a moist, oxidative environment. The tailings release high sulfate heavy metal-laden effluents into the New River basin. Four experimental columns were installed in the field for a 15-month period. The glycerol was applied to the surface of unweathered sulfidic tailings. The columns were left exposed to the atmosphere at the surface and buried within the existing tailings pile to simulate naturally occurring variations in temperature and rainfall. Platinum redox electrodes and porous cup lysimeters were installed to monitor redox and geochemical conditions within the unsaturated tailings. Water samples were collected throughout the experimental period and monitored for dissolved oxygen (DO), hydrogen sulfide (H{sub 2}S), and pH. Major cations and metals were analyzed using inductively coupled plasma spectroscopy. Results of the pilot tests demonstrated that the glycerol additions resulted in large and statistically significant decreases in Fe, sulfate (SO{sub 4}), and hot acidity. Changes in sodium (Na) and potassium (K) were limited. The glycerol additions reduced the rate of AMD production and treated the AMD after it was formed through H{sub 2}S production. Results of the study will be used to create a geochemical model for characterizing AMD production in the vadose zone of the tailing pile. 10 refs., 1 tab., 2 figs.

  19. Small molecule ice recrystallization inhibitors enable freezing of human red blood cells with reduced glycerol concentrations.

    Science.gov (United States)

    Capicciotti, Chantelle J; Kurach, Jayme D R; Turner, Tracey R; Mancini, Ross S; Acker, Jason P; Ben, Robert N

    2015-04-08

    In North America, red blood cells (RBCs) are cryopreserved in a clinical setting using high glycerol concentrations (40% w/v) with slow cooling rates (~1°C/min) prior to storage at -80°C, while European protocols use reduced glycerol concentrations with rapid freezing rates. After thawing and prior to transfusion, glycerol must be removed to avoid intravascular hemolysis. This is a time consuming process requiring specialized equipment. Small molecule ice recrystallization inhibitors (IRIs) such as β-PMP-Glc and β-pBrPh-Glc have the ability to prevent ice recrystallization, a process that contributes to cellular injury and decreased cell viability after cryopreservation. Herein, we report that addition of 110 mM β-PMP-Glc or 30 mM β-pBrPh-Glc to a 15% glycerol solution increases post-thaw RBC integrity by 30-50% using slow cooling rates and emphasize the potential of small molecule IRIs for the preservation of cells.

  20. Microbial production of succinic acid using crude and purified glycerol from a Crotalaria juncea based biorefinery

    Directory of Open Access Journals (Sweden)

    Suvra Sadhukhan

    2016-06-01

    Full Text Available Microbial conversion of crude and purified glycerol obtained in the process of biorefining Crotalaria juncea is carried out to produce succinic acid using Escherichia coli. Batch tests are performed for nine different substrate concentrations of commercial, purified and crude glycerol, in order to observe cell growth and substrate utilization rate. Inhibitory (Halden-Andrew, Aiba-Edward, Tessier type and Andrews as well as non-inhibitory (Monod, Moser and Tessier models are fitted to the relationship between specific growth rate and substrate concentration obtained from the growth curves. Considering the inhibition effect, Aiba-Edward model ranked 1 out of 7 in case of two samples and Haldane-Andrew model ranked 1 in case of one sample. Aiba-Edward model gave the best fitment for a large range of concentrations of all the three types of glycerol, crude, purified and laboratory grade. Maximum production of succinic acid is obtained from commercial glycerol at pH 7 and 37.5 °C.

  1. Glycerol derivatives of cutin and suberin monomers: synthesis and self-assembly.

    Science.gov (United States)

    Douliez, Jean-Paul; Barrault, Joël; Jerome, François; Heredia, Antonio; Navailles, Laurence; Nallet, Frédéric

    2005-01-01

    Glycerol derivatives of cutin and suberin monomers were synthesized by acid catalysis. Their dispersion in an aqueous solution was examined by phase contrast microscopy, neutron scattering, and solid state NMR. It is shown that the phase behavior strongly depends on the nature of the derivatives forming either lumps of aggregated membranes or well dispersed membranes.

  2. Synthesis of the Fatty Esters of Solketal and Glycerol-Formal: Biobased Specialty Chemicals

    Directory of Open Access Journals (Sweden)

    Alvise Perosa

    2016-01-01

    Full Text Available The caprylic, lauric, palmitic and stearic esters of solketal and glycerol formal were synthesized with high selectivity and in good yields by a solvent-free acid catalyzed procedure. No acetal hydrolysis was observed, notwithstanding the acidic reaction conditions.

  3. Evolution of structural relaxation spectra of glycerol within the gigahertz band

    Science.gov (United States)

    Franosch, T.; Göauttze, W.; Mayr, M. R.; Singh, A. P.

    1997-03-01

    The structural relaxation spectra and the crossover from relaxation to oscillation dynamics, as measured by Wuttke et al. [Phys. Rev. Lett. 72, 3052 (1994)] for glycerol within the GHz band by depolarized light scattering, are described by the solutions of a schematic mode coupling theory model. The applicability of scaling laws for the discussion of the model solutions is considered.

  4. Oxidation of Glycerol and Propanediols in Methanol over Heterogeneous Gold Catalysts

    DEFF Research Database (Denmark)

    Taarning, Esben; Madsen, Anders Theilgaard; Marchetti, Jorge

    2008-01-01

    Aerobic oxidation of glycerol over metal oxide supported gold nanoparticles in methanol results in the formation of dimethyl mesoxalate in selectivities up to 89% at full conversion. The oxidative esterification takes place in methanol, acting both as solvent and reactant, and in the presence...

  5. Enhanced cellulase production by Trichoderma harzianum by cultivation on glycerol followed by induction on cellulosic substrates.

    Science.gov (United States)

    Delabona, Priscila da Silva; Lima, Deise Juliana; Robl, Diogo; Rabelo, Sarita Cândida; Farinas, Cristiane Sanchez; Pradella, José Geraldo da Cruz

    2016-05-01

    The use of glycerol obtained as an intermediate of the biodiesel manufacturing process as carbon source for microbial growth is a potential alternative strategy for the production of enzymes and other high-value bioproducts. This work evaluates the production of cellulase enzymes using glycerol for high cell density growth of Trichoderma harzianum followed by induction with a cellulosic material. Firstly, the influence of the carbon source used in the pre-culture step was investigated in terms of total protein secretion and fungal morphology. Enzymatic productivity was then determined for cultivation strategies using different types and concentrations of carbon source, as well as different feeding procedures (batch and fed-batch). The best strategy for cellulase production was then further studied on a larger scale using a stirred tank bioreactor. The proposed strategy for cellulase production, using glycerol to achieve high cell density growth followed by induction with pretreated sugarcane bagasse, achieved enzymatic activities up to 2.27 ± 0.37 FPU/mL, 106.40 ± 8.87 IU/mL, and 9.04 ± 0.39 IU/mL of cellulase, xylanase, and β-glucosidase, respectively. These values were 2 times higher when compared to the control experiments using glucose instead of glycerol. This novel strategy proved to be a promising approach for improving cellulolytic enzymes production, and could potentially contribute to adding value to biomass within the biofuels sector.

  6. Chiral gas chromatography for the determination of 1,2-O-isopropylidene-sn-glycerol stereoisomers

    NARCIS (Netherlands)

    Dröge, M.J; Bos, R.; Woerdenbag, H.J.; Quax, Wim; Droge, MJ

    2003-01-01

    A stereospecific gas chromatography (GC) method using a (6-O-tButyldimethylsilyl-2,3-di-O-methyl)-beta-cyclodextrin as the chiral stationary phase has been developed and validated for the determination of the enantiomers of 1,2-O-isopropylidene-sn-glycerol (IPG), an important chiral synthon, in kine

  7. Poly(glycerol adipate)-fatty acid esters as versatile nanocarriers

    DEFF Research Database (Denmark)

    Weiss, Verena M; Naolou, Toufik; Hause, Gerd

    2012-01-01

    Poly(glycerol adipate) (PGA) is a biodegradable polymer with promising features for nanoparticulate drug carrier systems. By acylation of PGA with fatty acids, composite systems with amphiphilic properties can be obtained. Variation of the fatty acid (laurate, stearate and behenate) and their sub...

  8. Effect of Coconut, Sisal and Jute Fibers on the Properties of Starch/Gluten/Glycerol Matrix

    Science.gov (United States)

    Coconut, sisal and jute fibers were added as reinforcement materials in a biodegradable polymer matrix comprised of starch/gluten/glycerol. The content of fibers used in the composites varied from 5% to 30% by weight of the total polymers (starch and gluten). Materials were processed in a Haake torq...

  9. Microbial production of succinic acid using crude and purified glycerol from a Crotalaria juncea based biorefinery.

    Science.gov (United States)

    Sadhukhan, Suvra; Villa, Raffaella; Sarkar, Ujjaini

    2016-06-01

    Microbial conversion of crude and purified glycerol obtained in the process of biorefining Crotalaria juncea is carried out to produce succinic acid using Escherichia coli. Batch tests are performed for nine different substrate concentrations of commercial, purified and crude glycerol, in order to observe cell growth and substrate utilization rate. Inhibitory (Halden-Andrew, Aiba-Edward, Tessier type and Andrews) as well as non-inhibitory (Monod, Moser and Tessier) models are fitted to the relationship between specific growth rate and substrate concentration obtained from the growth curves. Considering the inhibition effect, Aiba-Edward model ranked 1 out of 7 in case of two samples and Haldane-Andrew model ranked 1 in case of one sample. Aiba-Edward model gave the best fitment for a large range of concentrations of all the three types of glycerol, crude, purified and laboratory grade. Maximum production of succinic acid is obtained from commercial glycerol at pH 7 and 37.5 °C.

  10. Glycerol enhances fungal germination at the water-activity limit for life

    NARCIS (Netherlands)

    Stevenson, Andrew; Hamill, Philip G; Medina, Ángel; Kminek, Gerhard; Rummel, John D; Dijksterhuis, Jan; Timson, David J; Magan, Naresh; Leong, Su-Lin L; Hallsworth, John E

    2016-01-01

    For the most-extreme fungal xerophiles, metabolic activity and cell division typically halts between 0.700 and 0.640 water activity (approximately 70.0-64.0% relative humidity). Here, we investigate whether glycerol can enhance xerophile germination under acute water-activity regimes, using an

  11. Wet oxidation of glycerol into fine organic acids: catalyst selection and kinetic evaluation

    Directory of Open Access Journals (Sweden)

    J. E. N. Brainer

    2014-12-01

    Full Text Available The liquid phase oxidation of glycerol was performed producing fine organic acids. Catalysts based on Pt, Pd and Bi supported on activated carbon were employed to perform the conversion of glycerol into organic acids at 313 K, 323 K and 333 K, under atmospheric pressure (1.0 bar, in a mechanically agitated slurry reactor (MASR. The experimental results indicated glycerol conversions of 98% with production of glyceric, tartronic and glycolic acids, and dihydroxyacetone. A yield of glyceric acid of 69.8%, and a selectivity of this compound of 70.6% were reached after 4 h of operation. Surface mechanisms were proposed and rate equations were formulated to represent the kinetic behavior of the process. Selective formation of glyceric acid was observed, and the kinetic parameter values indicated the lowest activation energy (38.5 kJ/mol for its production reaction step, and the highest value of the adsorption equilibrium constant of the reactant glycerol (10-4 dm³/mol.

  12. ETHANOL DEHYDRATION IN PACKED DISTILLATION COLUMN USING GLYCEROL AS ENTRAINER: EXPERIMENTS AND HETP EVALUATION

    Directory of Open Access Journals (Sweden)

    W. L. R. Souza

    Full Text Available Abstract The ethanol-water separation is very important because ethanol is widely applied in the chemical industry and its use as a fuel can reduce the pollution emitted to the air. However, anhydrous ethanol production using conventional distillation is impossible, at atmospheric pressure, due to the presence of an azeotrope. In the present work, experimental tests were carried out in order to evaluate the use of glycerol as an entrainer, in substitution of ethylene glycol in an extractive distillation. The use of glycerol is motivated by the biodiesel production units, due to the fact that it is the main byproduct and a new market is necessary to consume its overproduction. The experiments were carried out in a distillation column packed with Raschig rings, varying the glycerol/feed (ethanol and water ratio, S/F, from 0.5 to 0.9. The samples were analyzed using a digital densimeter. The results showed that glycerol was effective to promote ethanol dehydration and the presence of an azeotrope was not observed using a solvent to feed ratio (S/F equal to 0.9. Some empirical correlations were investigated to evaluate the HETP (Height Equivalent to a Theoretical Plate, and the results provided a useful tool for designing a packed bed column for ethanol-water separation.

  13. Milk supplements in a glycerol free trehalose freezing extender enhanced cryosurvival of boar spermatozoa

    Directory of Open Access Journals (Sweden)

    Rukmali Athurupana

    2016-03-01

    Conclusion: 2% skim milk can be used as supplements for a glycerol-free trehalose and egg yolk-based extender to improve post-thaw survival of boar spermatozoa, whereas 2% coconut milk has an effect to protect boar spermatozoa from acrosome damage.

  14. Synthesis of Acrolein from Glycerol Using FePO4 Catalyst in Liquid Phase Dehydration

    Directory of Open Access Journals (Sweden)

    Akhmad Zainal Abidin

    2016-02-01

    Full Text Available Acrolein is currently produced using propylene from crude oil while its price and scarcity are increasing. A renewable material such as glycerol is an attractive alternative for acrolein production. It can be obtained from crude palm oil (CPO and is a byproduct of biodiesel production. Besides being able to compete economically, glycerol is an environmentally friendly material. The purpose of this study is to synthesize acrolein from glycerol using FePO4 catalyst in liquid phase dehydration. The catalyst was prepared by three different methods: hydrothermal (catalyst A, deposition at Fe/P = 1.15 (catalyst B, and deposition at Fe/P = 1.20 (catalyst C. The experimental reaction temperature was varied at 220, 240 and 260 °C under constant atmospheric pressure. The results showed that catalyst C provided the best yield (91%, followed by catalyst A (90% and catalyst B (82%. The increasing reaction temperature showed a tendency to increase the yield of acrolein, while the presence of oxygen reduced the yield of acrolein and allowed the reaction to produce more side products such as glycerol propanal, acetaldehyde, and propionate. Catalyst reuse without any regeneration resulted in a yield profile of acrolein that continued to decline.

  15. Glycerol valorization: dehydration to acrolein over silica-supported niobia catalysts

    NARCIS (Netherlands)

    Shiju, N.R.; Brown, D.R.; Wilson, K.; Rothenberg, G.

    2010-01-01

    The catalytic dehydration of glycerol to acrolein is investigated over silica-supported niobia catalysts in a continuous fixed-bed gas-phase reactor. Various supported niobia catalysts are prepared and characterized using surface analysis and spectroscopic methods (XRD, UV-Vis, XPS, N2 adsorption),

  16. Bacterial Cellulose From Rice Waste Water With Addition Chitosan, Glycerol, And Silver Nanoparticle

    Directory of Open Access Journals (Sweden)

    Eli Rohaeti

    2016-05-01

    Full Text Available This study aimed to prepare silver nanoparticles chemically, deposite silver nanoparticles on bacterial cellulose-chitosan-glycerol composite based rice waste water, as well as test the antibacterial activity of bacterial cellulose and its composite. Preparation of silver nanoparticles was conducted by chemical reduction of silver nitrate solution, as well as trisodium citrate as the reductor. Bacterial cellulose from rice waste water is fermented by the bacteria Acetobacter xylinum for 7 days. The dried bacterial cellulose was composited with chitosan and glycerol by immersion method on 2% of chitosan solution and 0.5% of glycerol solution. UV-Vis spectroscopy is used to determine the formation of silvernanoparticles and Particle Size Analyzer to test the size and particle size distribution. Characterization was conducted to bacterial cellulose and its composite included functional groups by FTIR, the mechanical properties by Tensile Tester, crystallinity by XRD, surface photograph by SEM, and antibacterial test against S. aureus and E. coli by the shake flask turbidimetry method. Silver nanoparticle characterization indicated that silver nanoparticles are formed at a wavelength of 421.80 nm, yellow, diameter particle size of 61.8 nm. SEM images showed that the surface of bacterial cellulose had deposited silver nanoparticles and antibacterial test showed an inhibitory effect of bacterial cellulose, bacterial cellulose-chitosan composite, and bacterial cellulose-chitosan-glycerol composite which are deposited silver nanoparticles against the growth of S. aureus and E. coli bacteria.

  17. Development of poly(glycerol adipate) nanoparticles loaded with non-steroidal anti-inflammatory drugs.

    NARCIS (Netherlands)

    Wahab, A.; Favretto, M.E.; Onyeagor, N.D.; Khan, G.M.; Douroumis, D.; Casely-Hayford, M.A.; Kallinteri, P.

    2012-01-01

    The aim of this study was to assess acylated and non-acylated poly(glycerol adipate) polymers (PGA) as suitable nanoparticulate systems for encapsulation and release of ibuprofen, ibuprofen sodium salt (IBU-Na) and ketoprofen as model drugs. Drug encapsulated nanoparticles were prepared using the in

  18. Hydrogen production from glycerol on Ni/Al{sub 2}O{sub 3} catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, Esteban A.; D' Angelo, Miguel A.; Comelli, Raul A. [Instituto de Investigaciones en Catalisis y Petroquimica - INCAPE (F.I.Q.-U.N.L., CONICET), Santiago del Estero 2654, S3000AOJ - Santa Fe (Argentina)

    2010-06-15

    The growing demand of hydrogen needs renewable sources of raw materials to produce it. Glycerol, by-product of biodiesel synthesis, could be a bio-renewable substrate to obtain hydrogen. A Ni(5.8%)-alumina catalyst was evaluated in the steam reforming of glycerol at 600-700 C, atmospheric pressure, 16:1 water:glycerol molar ratio, and 3.4-10.0 h{sup -1} WHSV. A glycerol aqueous solution was fed, while a nitrogen stream was co-fed. After 4 h-on-stream, conversion was 96.8% at 600 C increasing to 99.4% at 700 C, reaching the largest hydrogen selectivity (99.7%) at 650 C. After 8 h, conversion decreases more significantly at 600 C, while the hydrogen selectivity does not significantly change with temperature and increases by decreasing WHSV. After 4 h, the main by-product was methane (76-97%), increasing at higher temperature, followed by ethene, ethane, propene, and propane. At 700 C and 10.0 h{sup -1} WHSV, the main by-products were ethene (47%) and methane (37%); it could be associated to catalyst deactivation. (author)

  19. Comparison of the effects of glycerol, mannitol, and urea on ischemic hippocampal damage in gerbils.

    Science.gov (United States)

    Otsubo, K; Katayama, Y; Kashiwagi, F; Muramatsu, H; Terashi, A

    1994-01-01

    The effects of glycerol and mannitol, as well as urea, on delayed neuronal death (DND) in the gerbil hippocampus were investigated. 20% solution of glycerol, mannitol and urea were prepared, and 6.5 ml/kg of each agent, or saline, was administered to male Mongolian gerbils intraperitoneally 30 min before ischemia. The animals were subjected to transient forebrain ischemia for 5 min. Seven days after the ischemic insult, the brains were fixed and stained for histopathological analysis. The number of normal neurons (neuronal density, ND) in a 1 mm linear length of hippocampal CA1 region was counted. ND of sham-operated group (n = 6) was 275.3 +/- 16.7 (mean +/- SD). ND in the saline-treated group (n = 6) was 14.8 +/- 5.0. ND of groups treated with glycerol (n = 6), mannitol (n = 6) and urea (n = 4) was 68.2 +/- 56.7 (p glycerol and mannitol have some protective effects against DND in the gerbil hippocampus, whereas urea has no effect.

  20. Effect of glycerol concentration on edible film production from cress seed carbohydrate gum.

    Science.gov (United States)

    Jouki, Mohammad; Khazaei, Naimeh; Ghasemlou, Mehran; Hadinezhad, Mehri

    2013-07-01

    In this study an edible film plasticized with glycerol was successfully prepared from cress seed gum (CSG). The physical, optical, water vapor permeability (WVP) and mechanical properties of CSG films incorporated with three levels of glycerol (25%, 35%, and 50% w/w) as plasticizer were determined. Dynamic mechanical thermal analysis was used to determine the glass transition temperature. WVP of the films was found to increase as the glycerol content increased from 25% to 50% w/w in the formulation, resulted in improvement of films flexibility and significantly lower tensile strength and higher elongation at break. The color measurement values showed that increasing the glycerol concentration in polymer matrix caused the b and L values increased while ΔE value decreased. The electron scanning micrograph indicated smooth and uniform surface morphology without signs of phase separation between the film components. The results of the present study demonstrated that CSG can promisingly be used in producing edible films with improved quality characteristics.