WorldWideScience

Sample records for lengthened slow titration

  1. [Titration comparative study of TOPINA Tablets in patients with localization related epilepsy: double-blind comparative study by rapid and slow titration methods].

    Science.gov (United States)

    Kaneko, Sunao; Inoue, Yushi; Sasagawa, Mutsuo; Kato, Masaaki

    2012-04-01

    To compare the tolerability and efficacy of two titration methods (rapid and slow titration) for TOPINA Tablets with different dosages and periods of escalation, a double-blind comparative study was conducted in patients with localization-related epilepsy. A total of 183 patients were randomized to either rapid titration (initial dosage 100 mg/day increased by 100-200 mg at weekly intervals) or to slow titration (initial dosage 50 mg/day increased in 50 mg/day increments at weekly intervals). TOPINA Tablets were administered for 12 weeks to the maximum dosage of 400 mg/day. The incident of adverse events leading to treatment interruptions or withdrawals was 18.9% in rapid titration and 14.8% in slow titration, with no statistical significance (p = 0.554). The incident of adverse events and adverse reactions of slow titration was slightly lower than that of rapid titration. The common adverse events and adverse reactions reported in the two titration methods were comparable and were well tolerated. On the other hand, the efficacy of slow titration, percent reduction in seizure rate and responder rate, was comparable with that of rapid titration. In conclusion, there were no significant differences of therapeutic response to TOPINA Tablets between the two titration methods.

  2. Benefit of slow titration of paroxetine to treat depression in the elderly.

    Science.gov (United States)

    Olgiati, Paolo; Bajo, Emanuele; Serretti, Alessandro

    2014-11-01

    Paroxetine is commonly used to treat depression in the elderly; however, titration issues have been raised. Rapid titration may lead to increased anxiety and early dropout. The aim of this cost-utility analysis was to compare the potential benefit of standard (10 mg the first day) versus slow titration (2.5 mg gradually increased). Clinical analysis was based on a naturalistic trial integrated with a decision-analytic model representing second treatments for those who initially did not respond and for dropout cases. Treatment setting was a public outpatient center for mental disorders in Italy. Service use data were estimated from best practice guidelines, whereas costs (Euros; 2012) were retrieved from Italian official sources. Slow titration approach produced 0.031 more quality-adjusted life years (remission rate: 57% vs 44% in standard titration group) at an incremental cost of €5.53 (generic paroxetine) and €54.54 (brand paroxetine syrup). Incremental cost-effectiveness ratio (ICER) values were €159 and €1768, respectively, in favor of slow titration approach. Cost-effectiveness threshold, defined as ICER titration of paroxetine in older depressed patients. However, these findings, in part based on simulated data, need to be replicated in clinical trials. Copyright © 2014 John Wiley & Sons, Ltd.

  3. Persistent benefits of slow titration of paroxetine in a six-month follow-up.

    Science.gov (United States)

    Olgiati, Paolo; Serretti, Alessandro

    2015-09-01

    Paroxetine titration may be difficult in older individuals as they are more sensitive to side effects. The current study extends to 6 months our previously published report in which paroxetine was started at 2.5 mg/day and slowly increased by 2.5 mg on alternate days (slow titration) or rapidly titrated to target dose from 10 mg/day (standard titration) in a naturalistic setting. Here, the follow-up period was extended to 26 weeks. We performed an intent-to-treat analysis of 47 subjects from the original sample (major depressive disorder and/or generalized anxiety disorder (GAD); >60 years of age). Missing evaluations were replaced by last observations carried forward. GAD was included as a stratification factor. Patients in whom paroxetine was slowly up-titrated were more likely to remit (84.0% vs 54.5%; p = 0.028) and had lower core depression (p = 0.0015) and psychic anxiety levels (p = 0.006) after 26 weeks. Dropout rate was 20% in the slow titration group compared with 77.3% in the standard titration arm (p titration groups in the subsample without GAD. Despite some limitations, these findings suggest that paroxetine treatment should be started at lower doses in older depressed patients and slowly up-titrated. This strategy would allow to increase antidepressant response and the likelihood of completing treatment cycle in patients with high anxiety levels and GAD comorbidity. Copyright © 2015 John Wiley & Sons, Ltd.

  4. Potential benefits of slow titration of paroxetine treatment in an elderly population: eight-week results from a naturalistic setting.

    Science.gov (United States)

    Gibiino, Sara; Mori, Elisa; De Ronchi, Diana; Serretti, Alessandro

    2013-08-01

    Late-life depression, often in association with anxiety, affects approximately 15% of individuals older than 65 years. Selective serotonin reuptake inhibitors are the first-line treatment but could be responsible of an early exacerbation of anxiety, possibly reduced by a very gradual titration of drugs. The main aim of this study is to compare gradual and rapid (standard) titration of paroxetine in an elderly population. In a naturalistic setting, 50 elderly (≥60 years old) outpatients with unipolar mood disorder or anxiety disorder were naturalistically assigned to abrupt initiation of 10 mg of paroxetine or to a gradual increase with 2.5 mg on alternate days up to 10 mg in 7 days. Then dosage could be maintained at 10 mg or increased according to clinical response. Primary outcome was efficacy as assessed by the Hamilton Depression Rating Scale (HAM-D) 21, HAM-D symptom subscales (core, psychic anxiety, somatic anxiety cluster), and Hamilton Anxiety Rating Scale changes. Secondary outcome was evaluation of overall dropouts at eighth week and evaluation of most common adverse effects through the global judgment of the Dosage Record and Treatment Emergent Symptom Scale. All data were recorded weekly for the first 8 weeks of treatment (with 1 more evaluation after 3 days from the baseline). Samples were comparable at baseline, with patients in gradual titration showing a higher level of psychic anxiety. During the first 3 days of treatment, a significant worsening in psychic anxiety was observed in patients treated abruptly with 10 mg of paroxetine (difference in HAM-D psychic anxiety subscale from baseline: 110.61% vs 89.38% with rapid and slow titration, respectively; t test P = 0.03). Overall, a significantly greater improvement in depressive and anxious symptoms favored gradual titration (HAM-D core cluster and HAM-D psychic anxiety cluster, respectively, P = 0.014 and P titration). Our results suggest that a gradual titration of paroxetine could avoid the

  5. Percutaneous Achilles Tendon Lengthening

    Science.gov (United States)

    ... All Site Content AOFAS / FootCareMD / Treatments Percutaneous Achilles Tendon Lengthening Page Content ​ Pre-operative incision markings along ... What is the goal of a percutaneous Achilles tendon lengthening? The goal of this procedure is to ...

  6. Leg lengthening - slideshow

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/presentations/100127.htm Leg lengthening - series—Indications To use the sharing features ... with lengthening procedures are the bones of the leg, the tibia and the femur. Surgical treatment may ...

  7. Leg lengthening and shortening

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/002965.htm Leg lengthening and shortening To use the sharing features on this page, please enable JavaScript. Leg lengthening and shortening are types of surgery to ...

  8. Limb lengthening in achondroplasia

    Directory of Open Access Journals (Sweden)

    Sanjay K Chilbule

    2016-01-01

    Full Text Available Background: Stature lengthening in skeletal dysplasia is a contentious issue. Specific guidelines regarding the age and sequence of surgery, methods and extent of lengthening at each stage are not uniform around the world. Despite the need for multiple surgeries, with their attendant complications, parents demanding stature lengthening are not rare, due to the social bias and psychological effects experienced by these patients. This study describes the outcome and complications of extensive stature lengthening performed at our center. Materials and Methods: Eight achondroplasic and one hypochondroplasic patient underwent bilateral transverse lengthening for tibiae, humeri and femora. Tibia lengthening was carried out using a ring fixator and bifocal corticotomy, while a monolateral pediatric limb reconstruction system with unifocal corticotomy was used for the femur and humerus. Lengthening of each bone segment, height gain, healing index and complications were assessed. Subgroup analysis was carried out to assess the effect of age and bone segment on the healing index. Results: Nine patients aged five to 25 years (mean age 10.2 years underwent limb lengthening procedures for 18 tibiae, 10 femora and 8 humeri. Four patients underwent bilateral lengthening of all three segments. The mean length gain for the tibia, femur and humerus was 15.4 cm (100.7%, 9.9 cm (52.8% and 9.6 cm (77.9%, respectively. Healing index was 25.7, 25.6 and 20.6 days/cm, respectively, for the tibia, femur and humerus. An average of 33.3% height gain was attained. Lengthening of both tibia and femur added to projected height achieved as the 3 rd percentile of standard height in three out of four patients. In all, 33 complications were encountered (0.9 complications per segment. Healing index was not affected by age or bone segment. Conclusion: Extensive limb lengthening (more than 50% over initial length carries significant risk and should be undertaken only after due

  9. Crown lengthening procedures

    Directory of Open Access Journals (Sweden)

    AA. Khoshkhonejad

    1994-06-01

    Full Text Available Nowadays, due to recent developments and researches in dental science, it is possible to preserve and restore previously extracted cases such as teeth with extensive caries, fractured or less appropriate cases for crown coverage as well as teeth with external perforation caused by restorative pins. In order to restore the teeth with preservation of periodontium, we should know thoroughly physiological aspects of periodontium and protection of Biologic Width which is formed by epithelial and supracrestal connective tissue connections. Considering biologic width is one of the principal rules of teeth restoration, otherwise we may destruct periodontal tissues. Several factors are involved in placing a restoration and one of the most important ones is where the restoration margin is terminated. Many studies have been conducted on the possible effects of restoration margin on the gingiva and due to the results of these studies it was concluded that restoration margin should be finished supragingivally. However, when we have to end the restoration under Gingival Crest, First a healthy gingival sulcus is required. Also, we should not invade the biological width. Since a normal biologic with is reported 2 mm and sound tooth tissue should be placed at least 2 mm coronal to the epithelial tissue, the distance between sound tooth tissue and crown margin should be at least 4mm. Thus, performing crown lengthening is essential to increase the clinical crown length. Basically, two objectives are considered: 1 restorative 2 esthetic (gummy smile Surgical procedure includes gingivectomy and flap procedure. Orthodontic procedure involves orthodontic extrusion or force eruption technique which is controlled vertical movements of teeth into occlusion. Besides, this procedure can also used to extrude teeth defects from the gingival tissue. By crown lengthening, tooth extraction is not required and furthermore, adjacent teeth preparation for placing a fixed

  10. Limb Lengthening in Patients with Achondroplasia.

    Science.gov (United States)

    Park, Kwang-Won; Garcia, Rey-an Niño; Rejuso, Chastity Amor; Choi, Jung-Woo; Song, Hae-Ryong

    2015-11-01

    Although bilateral lower-limb lengthening has been performed on patients with achondroplasia, the outcomes for the tibia and femur in terms of radiographic parameters, clinical results, and complications have not been compared with each other. We proposed 1) to compare the radiological outcomes of femoral and tibial lengthening and 2) to investigate the differences of complications related to lengthening. We retrospectively reviewed 28 patients (average age, 14 years 4 months) with achondroplasia who underwent bilateral limb lengthening between 2004 and 2012. All patients first underwent bilateral tibial lengthening, and at 9-48 months (average, 17.8 months) after this procedure, bilateral femoral lengthening was performed. We analyzed the pixel value ratio (PVR) and characteristics of the callus of the lengthened area on serial radiographs. The external fixation index (EFI) and healing index (HI) were computed to compare tibial and femoral lengthening. The complications related to lengthening were assessed. The average gain in length was 8.4 cm for the femur and 9.8 cm for the tibia. The PVR, EFI, and HI of the tibia were significantly better than those of the femur. Fewer complications were found during the lengthening of the tibia than during the lengthening of the femur. Tibial lengthening had a significantly lower complication rate and a higher callus formation rate than femoral lengthening. Our findings suggest that bilateral limb lengthening (tibia, followed by femur) remains a reasonable option; however, we should be more cautious when performing femoral lengthening in selected patients.

  11. base titration

    African Journals Online (AJOL)

    The pH and temperature in the titration cell were monitored using single junction electrodes and platinum resistance thermometers, respectively. A constant supply of nitrogen gas in the cell was used to maintain inert conditions. The whole set up was interfaced with a computer for easy data acquisition. It was observed that ...

  12. Radiographic imaging for Ilizarov limb lengthening in children

    International Nuclear Information System (INIS)

    Blane, C.E.; DiPietro, M.A.; Herzenberg, J.E.

    1991-01-01

    The Ilizarov method for limb lengthening is rapidly gaining popularity in North America. Use of this new technique has necessitated modifications in radiographic protocol. Initial imaging problems gained from our experience with twenty children are detailed including accurate centering for the plain films, correcting for magnification to accurately measure the distraction gap and the expected radiographic appearance of the regenerate bone. Ultrasonography has potential value in accurately measuring the distraction gap and in imaging the new bone prior to radiographic appearance. Since overly fast distraction inhibits bone formation and overly slow distraction leads to premature consolidation, ultrasound may serve a useful role in the qualitative evaluation of new bone formation in Ilizarov limb lengthening, enabling the orthopedic surgeon to tailor the distraction rate to the particular child. (orig.)

  13. Risks and Benefits of Rapid Clozapine Titration.

    Science.gov (United States)

    Lochhead, Jeannie D; Nelson, Michele A; Schneider, Alan L

    2016-05-18

    Clozapine is often considered the gold standard for the treatment of schizophrenia. Clinical guidelines suggest a gradual titration over 2 weeks to reduce the risks of adverse events such as seizures, hypotension, agranulocytosis, and myocarditis. The slow titration often delays time to therapeutic response. This raises the question of whether, in some patients, it may be safe to use a more rapid clozapine titration. The following case illustrates the potential risks associated with the use of multiple antipsychotics and rapid clozapine titration. We present the case of a young man with schizophrenia who developed life threatening neuroleptic malignant syndrome (NMS) during rapid clozapine titration and treatment with multiple antipsychotics. We were unable to find another case in the literature of NMS associated with rapid clozapine titration. This case is meant to urge clinicians to carefully evaluate the risks and benefits of rapid clozapine titration, and to encourage researchers to further evaluate the safety of rapid clozapine titration. Rapid clozapine titration has implications for decreasing health care costs associated with prolonged hospitalizations, and decreasing the emotional suffering associated with uncontrolled symptoms of psychosis. Clozapine is considered the most effective antipsychotic available thus efforts should focus on developing strategies that would allow for safest and most efficient use of clozapine to encourage its utilization for treatment resistance schizophrenia.

  14. Risks and benefits of rapid clozapine titration

    Directory of Open Access Journals (Sweden)

    Jeannie D. Lochhead

    2016-05-01

    Full Text Available Clozapine is often considered the gold standard for the treatment of schizophrenia. Clinical guidelines suggest a gradual titration over 2 weeks to reduce the risks of adverse events such as seizures, hypotension, agranulocytosis, and myocarditis. The slow titration often delays time to therapeutic response. This raises the question of whether, in some patients, it may be safe to use a more rapid clozapine titration. The following case illustrates the potential risks associated with the use of multiple antipsychotics and rapid clozapine titration. We present the case of a young man with schizophrenia who developed life threatening neuroleptic malignant syndrome (NMS during rapid clozapine titration and treatment with multiple antipsychotics. We were unable to find another case in the literature of NMS associated with rapid clozapine titration. This case is meant to urge clinicians to carefully evaluate the risks and benefits of rapid clozapine titration, and to encourage researchers to further evaluate the safety of rapid clozapine titration. Rapid clozapine titration has implications for decreasing health care costs associated with prolonged hospitalizations, and decreasing the emotional suffering associated with uncontrolled symptoms of psychosis. Clozapine is considered the most effective antipsychotic available thus efforts should focus on developing strategies that would allow for safest and most efficient use of clozapine to encourage its utilization for treatment resistance schizophrenia.

  15. [Lengthening temporalis myoplasty: Technical refinements].

    Science.gov (United States)

    Guerreschi, P; Labbé, D

    2015-10-01

    First described by Labbé in 1997, the lengthening temporalis myoplasty (LTM) ensures the transfer of the entire temporal muscle from the coronoid process to the upper half of the lip without interposition of aponeurotic tissue. Thanks to brain plasticity, the temporal muscle is able to change its function because it is entirely mobilized towards another effector: the labial commissure. After 6 months of speech rehabilitation, the muscle loses its chewing function and it acquires its new smiling function. We describe as far as possible all the technical points to guide surgeons who would like to perform this powerful surgical procedure. We show the coronoid process approaches both through an upper temporal fossa approach and a lower nasolabial fold approach. Rehabilitation starts 3 weeks after the surgery following a standardized protocol to move from a mandibular smile to a voluntary smile, and then a spontaneous smile in 3 steps. The LTM is the main part of a one-stage global treatment of the paralyzed face. It constitutes a dynamic palliative treatment usually started at the sequelae stage, 18 months after the outcome of a peripheral facial paralysis. This one-stage procedure is a reproducible and relevant surgical technique in the difficult treatment of peripheral facial paralysis. An active muscle is transferred to reanimate the labial commissure and to recreate a mobile nasolabial fold. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  16. Intestinal lengthening: an experimental and clinical review.

    Science.gov (United States)

    Bianchi, A

    1984-01-01

    Small intestinal lengthening by the Bianchi procedure has now had successful clinical application in children and neonates with the short-bowel syndrome. This paper reviews the background experimental work and clinical cases so far treated. A personal case of intestinal lengthening in a 7-week-old baby with 35 cm jejunum is described in detail. Intestinal lengthening appears to reduce dependence on parenteral nutrition, thus allowing earlier establishment of total enteral alimentation. The procedure may therefore have a useful place in the overall management of the short-bowel syndrome. Images Figure 3. A Figure 3. B Figure 3. C Figure 3. D PMID:6471060

  17. Cosmetic lengthening: what are the limits?

    Science.gov (United States)

    Guerreschi, F; Tsibidakis, H

    2016-12-01

    In the last decades, limb lengthening has not been limited to the treatment of patients with dwarfism and deformities resulting from congenital anomalies, trauma, tumor and infections, but, has also been used for aesthetic reasons. Cosmetic lengthening by the Ilizarov method with circular external fixation has been applied to individuals with constitutional short stature who wish to be taller. From January 1985 to December 2010, the medical records of 63 patients with constitutional short stature (36 M, 27F; 126 legs) who underwent cosmetic bilateral leg lengthening using a hybrid advanced fixator according to the Ilizarov method, were reviewed, retrospectively. The mean age was 24.8 years, while the mean preoperative height was 152.6 cm. Paley's criteria were used to evaluate problems, obstacles, and complications from the time of surgery until 1 year after frame's removal. The mean lengthening achieved in all patients was 7.2 cm (range: 5-11 cm), with a mean duration of treatment of 9 months and 15 days (range: 7-18 months). The mean follow-up time was 6.14 years (range 1-10). The cosmetic leg lengthening was helpful to all patients, improving their social capabilities and self-confidence. All patients considered their stature as normal and they reported satisfaction and gratification with important changes in their professional and personal life. Cosmetic leg lengthening may raise some ethical objections and for that reason patients should be well informed about all the risks and complications related to this type of surgery.

  18. Indications & predisposing factors of crown lengthening surgery

    Directory of Open Access Journals (Sweden)

    Arghavan Amini-Behbahani

    2014-09-01

    Full Text Available Introduction: Since crown lengthening surgery could be accompanied by stress, pain and discomfort, knowledge about its predisposing factors could reduce the demands for such surgery.The aim of this study was to identify the most important indications of crown lengthening surgery in order to present new ideas to clinicians on how to reduce the need for this surgery. Methods: This cross-sectional study was done on 470 patients (aged 12-89 years referred for crown lengthening surgery. The patients' demographic data and their reasons for surgery, the teeth restoration condition and its type, condition of the opposite tooth, type of fractured cusp (posterior teeth, root canal therapy condition and quality, and size of existing intracanal posts were recorded in a data sheet. Data were analyzed by using SPSS software.The chi-square and fisher exact test were used for statistical analysis. The significant difference was p<0.05. Results: The most frequent indication in men and women was dental caries followed by tooth fracture.The second upper premolars and first lower molars needed crown lengthening surgery more often, respectively. Conclusions: Since dental caries and fracture are the most important factors that predispose teeth to crown lengthening surgery, controlling caries with a regular recall sequence can reduce the need for such surgery, especially in the elderly.

  19. A Brief History of Limb Lengthening.

    Science.gov (United States)

    Birch, John G

    2017-09-01

    In the last 35 years, orthopaedic surgeons have witnessed 3 major advances in the technique of limb lengthening: "distraction osteogenesis" facilitated by Gavriil Ilizarov method and infinitely-adaptable circular fixator with fine-wire bone fragment fixation; the introduction of the "6-strut" computer program-assisted circular fixators to effect complex deformity correction simultaneously; and the development of motorized intramedullary lengthening nails. However, the principles and associated complications of these techniques are on the basis of observations by Codivilla, Putti, and Abbott from as much as 110 years ago. This review notes the contribution of these pioneers in limb lengthening, and the contribution of Thor Heyerdahl principles of tolerance and diversity to the dissemination of Ilizarov principles to the Western world.

  20. Repeated mechanical lengthening of intestinal segments in a novel model.

    Science.gov (United States)

    Scott, Andrew; Sullins, Veronica F; Steinberger, Doug; Rouch, Joshua D; Wagner, Justin P; Chiang, Elvin; Lee, Steven L; Wu, Benjamin M; Dunn, James C Y

    2015-06-01

    Currently, animal models used for mechanical intestinal lengthening utilize a single lengthening procedure prior to analysis or restoration back into continuity. Here we developed a novel surgical model to examine the feasibility of repeated lengthening of intestinal segments. A Roux-en-Y jejunojejunostomy with a blind Roux limb was created in rats. An encapsulated polycaprolactone spring was placed into a 1cm segment of the Roux limb. After 4 weeks, a second encapsulated PCL spring was inserted into a 1cm portion of the lengthened segment. After another 4 weeks, the repeatedly lengthened segments were retrieved for histological analyses. Jejunal segments of the Roux limb were successfully lengthened from 1.0 cm to 2.6 ± 0.7 cm. Four weeks after the second PCL spring placement, 1.0 cm of the previously lengthened segment increased to 2.7 ± 0.8 cm. Stronger mechanical force was required to achieve subsequent re-lengthening. Lengthened and re-lengthened segments had increased smooth muscle thickness and crypt depth when compared to normal jejunal mucosa. Using the Roux-en-Y model, previously lengthened segments of intestine can be successfully re-lengthened. Intestinal segments may be subjected to multiple lengthening procedures to achieve clinically significant length for the treatment of short bowel syndrome. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Automated uranium titration system

    International Nuclear Information System (INIS)

    Takahashi, M.; Kato, Y.

    1983-01-01

    An automated titration system based on the Davies-Gray method has been developed for accurate determination of uranium. The system consists of a potentiometric titrator with precise burettes, a sample changer, an electronic balance and a desk-top computer with a printer. Fifty-five titration vessels are loaded in the sample changer. The first three contain the standard solution for standardizing potassium dichromate titrant, and the next two and the last two contain the control samples for data quality assurance. The other forty-eight measurements are carried out for sixteen unknown samples. Sample solution containing about 100 mg uranium is taken in a titration vessel. At the pretreatment position, uranium (VI) is reduced to uranium (IV) by iron (II). After the valency adjustment, the vessel is transferred to the titration position. The rate of titrant addition is automatically controlled to be slower near the end-point. The last figure (0.01 mL) of the equivalent titrant volume for uranium is calculated from the potential change. The results obtained with this system on 100 mg uranium gave a precision of 0.2% (RSD,n=3) and an accuracy of better than 0.1%. Fifty-five titrations are accomplished in 10 hours. (author)

  2. Hip stability during lengthening in children with congenital femoral deficiency.

    Science.gov (United States)

    Eidelman, Mark; Jauregui, Julio J; Standard, Shawn C; Paley, Dror; Herzenberg, John E

    2016-12-01

    Congenital femoral deficiency (CFD) is one of the most challenging and complex conditions for limb lengthening. We focused on the problem of hip instability during femoral lengthening because subluxation and dislocation are potentially catastrophic for hip function. We assessed for hip stability in 69 children (91 femoral lengthenings) who had CFD Paley type 1a (43 children) and 1b (26 children). The mean age at first lengthening was 6.4 years. Hip subluxation/dislocation occurred during 14 (15 %) of 91 lengthenings. Thirty-three pelvic osteotomies were performed before lengthening in an attempt to stabilize hips. Thirteen patients (type 1a, eight; type 1b, five) had acetabular dysplasia at initiation of lengthening. One of the eight with type 1a experienced mild femoral head subluxation; four of the five with type 1b experienced three dislocations and one subluxation. Eight patients (type 1b) experienced hip instability although they had pelvic osteotomies. Proximal femoral lengthening was a significant factor for hip subluxation. Patients with hip subluxation more likely underwent monolateral fixation and the original superhip procedure. Age ±six years was not a contributing factor for hip instability. Important risk factors for hip instability during femoral lengthening are severity of CFD, residual acetabular dysplasia, and proximal femoral lengthening. We recommend routine performance of pelvic osteotomy for patients with Paley type 1b CFD and distal lengthening. Therapeutic Level IV.

  3. The telomere lengthening conundrum - artifact or biology?

    DEFF Research Database (Denmark)

    Steenstrup, Troels; Hjelmborg, Jacob V B; Kark, Jeremy D

    2013-01-01

    . Based on empirical data and theoretical considerations, we show that regardless of the method used to measure telomere length (Southern blot or quantitative polymerase chain reaction-based methods), measurement error of telomere length and duration of follow-up explain almost entirely the absence of age......-dependent LTL attrition in longitudinal studies. We find that LTL lengthening is far less frequent in studies with long follow-up periods and those that used a high-precision Southern blot method (as compared with quantitative polymerase chain reaction determination, which is associated with larger laboratory...

  4. Oral Crest Lengthening for Increasing Removable Denture Retention by Means of CO2 Laser

    Directory of Open Access Journals (Sweden)

    Samir Nammour

    2014-01-01

    Full Text Available The loss of teeth and their replacement by artificial denture is associated with many problems. The denture needs a certain amount of ridge height to give it retention and a long-term function. Crest lengthening procedures are performed to provide a better anatomic environment and to create proper supporting structures for more stability and retention of the denture. The purpose of our study is to describe and evaluate the effectiveness of CO2 laser-assisted surgery in patients treated for crest lengthening (vestibular deepening. There have been various surgical techniques described in order to restore alveolar ridge height by pushing muscles attaching of the jaws. Most of these techniques cause postoperative complications such as edemas, hemorrhage, pain, infection, slow healing, and rebound to initial position. Our clinical study describes the treatment planning and clinical steps for the crest lengthening with the use of CO2 laser beam (6–15 Watts in noncontact, energy density range: 84.92–212.31 J/cm2, focus, and continuous mode with a focal point diameter of 0.3 mm. At the end of each surgery, dentures were temporarily relined with a soft material. Patients were asked to mandatorily wear their relined denture for a minimum of 4–6 weeks and to remove it for hygienic purposes. At the end of each surgery, the deepest length of the vestibule was measured by the operator. No sutures were made and bloodless wounds healed in second intention without grafts. Results pointed out the efficiency of the procedure using CO2 laser. At 8 weeks of post-op, the mean of crest lengthening was stable without rebound. Only a loss of 15% was noticed. To conclude, the use of CO2 laser is an effective option for crest lengthening.

  5. Filtrates & Residues: Olfactory Titration.

    Science.gov (United States)

    Wood, John T.; Eddy, Roberta M.

    1996-01-01

    Presents an experiment that uses a unique acid-base indicator--the odor of raw onion--to indicate the end point of the titration of sodium hydroxide with hydrochloric acid. Allows the student to detect the completion of the neutralization reaction by olfaction rather than sight. (JRH)

  6. ''Titration'' polymerization of monovinylacetylene

    NARCIS (Netherlands)

    Mavinkurve, A; Visser, S; vandenBroek, W; Pennings, AJ

    1996-01-01

    A polymer consisting of a saturated carbon backbone with pendent acetylenic groups was prepared from monovinylacetylene. A titration was performed between the monomer and tertiary butyllithium, its lithiating agent. The charge transfer complex formed between the solvent THF and the tertiary

  7. The influence of muscular lengthening on cramps.

    Science.gov (United States)

    Bertolasi, L; De Grandis, D; Bongiovanni, L G; Zanette, G P; Gasperini, M

    1993-02-01

    Muscle cramps induced by voluntary contraction and by electrical stimulation of the peripheral nerve were studied electrophysiologically in 10 healthy subjects. The aim was to verify that cramps can be evoked by electrical stimulation of peripheral nerve and to clarify the physiological mechanism responsible by analyzing the effect of muscular stretching on cramps. Our results showed: (1) Cramps can be induced even after peripheral nerve block by electrical stimulation distal to the block. (2) No cramps were recorded during or following maximal voluntary contraction without muscular shortening, while 7 of 10 subjects showed a true cramp following maximal effort with shortening of the muscle. (3) Muscle stretching caused a sudden interruption of cramps induced by either voluntary contraction or electrical stimulation of the peripheral nerve, even after the induction of nerve block. (4) The lengthening state of the muscle can strongly influence the possibility of evoking cramps by electrical stimulation of nerve. Our study verifies the experimental model proposed by Lambert in 1969, emphasizing the relevance of frequency of stimulation and confirming the hypothesis that cramps are of peripheral origin. The effects of muscle stretch and lengthening on cramp interruption and development also have a peripheral mechanism.

  8. Titration Curves: Fact and Fiction.

    Science.gov (United States)

    Chamberlain, John

    1997-01-01

    Discusses ways in which datalogging equipment can enable titration curves to be measured accurately and how computing power can be used to predict the shape of curves. Highlights include sources of error, use of spreadsheets to generate titration curves, titration of a weak acid with a strong alkali, dibasic acids, weak acid and weak base, and…

  9. Coulometric titration of niobium in EDTA complexing solution

    International Nuclear Information System (INIS)

    Pannu, S.S.

    1976-01-01

    Constant current coulometry of Nb in EDTA was studied employing both potentiometric and amperometric end-point techniques. The titrations were based on the oxidation of Nb(IV)-EDTA with electrogenerated Fe(III) at a graphite anode. The rate of disproportionation of Nb(IV)-EDTA was found to be slow enough not to effect the accuracy sought for the titration. The coulometric titration of Nb in EDTA was found to be more accurate than in 1F sulfuric acid. The mean error in the titrations of 4.76 to 19.65 of Nb in a volume of about 100 ml of 0.02 to 0.04F EDTA was 0.13%. It was found that Ta may be tolerated to a ratio of 1:4, Ta:Nb, in a solution containing 13 mg of Nb. (author)

  10. Physeal growth arrest after tibial lengthening in achondroplasia

    Science.gov (United States)

    2012-01-01

    Background and purpose Bilateral tibial lengthening has become one of the standard treatments for upper segment-lower segment disproportion and to improve quality of life in achondroplasia. We determined the effect of tibial lengthening on the tibial physis and compared tibial growth that occurred at the physis with that in non-operated patients with acondroplasia. Methods We performed a retrospective analysis of serial radiographs until skeletal maturity in 23 achondroplasia patients who underwent bilateral tibial lengthening before skeletal maturity (lengthening group L) and 12 achondroplasia patients of similar height and age who did not undergo tibial lengthening (control group C). The mean amount of lengthening of tibia in group L was 9.2 cm (lengthening percentage: 60%) and the mean age at the time of lengthening was 8.2 years. The mean duration of follow-up was 9.8 years. Results Skeletal maturity (fusion of physis) occurred at 15.2 years in group L and at 16.0 years in group C. The actual length of tibia (without distraction) at skeletal maturity was 238 mm in group L and 277 mm in group C (p = 0.03). The mean growth rates showed a decrease in group L relative to group C from about 2 years after surgery. Physeal closure was most pronounced on the anterolateral proximal tibial physis, with relative preservation of the distal physis. Interpretation Our findings indicate that physeal growth rate can be disturbed after tibial lengthening in achondroplasia, and a close watch should be kept for such an occurrence—especially when lengthening of more than 50% is attempted. PMID:22489887

  11. Early and late fracture following extensive limb lengthening in patients with achondroplasia and hypochondroplasia.

    Science.gov (United States)

    Kitoh, H; Mishima, K; Matsushita, M; Nishida, Y; Ishiguro, N

    2014-09-01

    Two types of fracture, early and late, have been reported following limb lengthening in patients with achondroplasia (ACH) and hypochondroplasia (HCH). We reviewed 25 patients with these conditions who underwent 72 segmental limb lengthening procedures involving the femur and/or tibia, between 2003 and 2011. Gender, age at surgery, lengthened segment, body mass index, the shape of the callus, the amount and percentage of lengthening and the healing index were evaluated to determine predictive factors for the occurrence of early (within three weeks after removal of the fixation pins) and late fracture (> three weeks after removal of the pins). The Mann‑Whitney U test and Pearson's chi-squared test for univariate analysis and stepwise regression model for multivariate analysis were used to identify the predictive factor for each fracture. Only one patient (two tibiae) was excluded from the analysis due to excessively slow formation of the regenerate, which required supplementary measures. A total of 24 patients with 70 limbs were included in the study. There were 11 early fractures in eight patients. The shape of the callus (lateral or central callus) was the only statistical variable related to the occurrence of early fracture in univariate and multivariate analyses. Late fracture was observed in six limbs and the mean time between removal of the fixation pins and fracture was 18.3 weeks (3.3 to 38.4). Lengthening of the tibia, larger healing index, and lateral or central callus were related to the occurrence of a late fracture in univariate analysis. A multivariate analysis demonstrated that the shape of the callus was the strongest predictor for late fracture (odds ratio: 19.3, 95% confidence interval: 2.91 to 128). Lateral or central callus had a significantly larger risk of fracture than fusiform, cylindrical, or concave callus. Radiological monitoring of the shape of the callus during distraction is important to prevent early and late fracture of lengthened

  12. Potentiometric titration with polarized electrodes

    International Nuclear Information System (INIS)

    Chikryzova, E.G.

    1977-01-01

    Based on the analysis of the works carried out during 1911-75 consideration is given to the present state of the method of potentiometric titration with polarized electrodes. The material is generalized in the tabular form indicating the elments of interest, titration conditions and the objects to be analyzed. The list and classification of the potentiometric titration methods intended for determining organic and inorganic substances are presented

  13. Limb lengthening in Africa: tibial lengthening indicated for limb length discrepancy and postosteomyelitis pseudarthrosis

    Directory of Open Access Journals (Sweden)

    Ibrahima F

    2014-05-01

    Full Text Available Farikou Ibrahima,1,2 Pius Fokam,2 Félicien Faustin Mouafo Tambo11Department of Surgery and Specialties, Faculty of Medicine and Biomedical Sciences, University of Yaoundé I, Yaoundé, 2Department of Surgery, Douala General Hospital, Douala, CameroonBackground: We present a case of lengthening of a tibia to treat postosteomyelitis pseudarthrosis and limb length discrepancy by the Ilizarov device.Objective: The objective was to treat the pseudarthrosis and correct the consequent limb length discrepancy of 50 mm.Materials and methods: The patient was a 5-year-old boy. Osteotomy of the tibia, excision of fibrosis, and decortications were carried out. After a latency period of 5 days, the lengthening started at a rate of 1 mm per day.Results: The pseudarthrosis healed and the gained correction was 21.73%. The index consolidation was 49 days/cm. Minor complications were reported.Discussion: Osteomyelitis of long bones is a common poverty-related disease in Africa. The disease usually is diagnosed at an advanced stage with complications. In these conditions, treatment is much more difficult. Most surgical procedures treating this condition use the Ilizarov device. The most common reported surgical complications are refractures and recurrence of infection.Conclusion: This technique should be popularized in countries with limited resources because it would be an attractive alternative to the amputations that are sometimes performed.Keywords: Limb length discrepancy (LLD, bone gap, Ilizarov device

  14. Surgical crown lengthening: a periodontal and restorative interdisciplinary approach.

    Science.gov (United States)

    Parwani, Simran R; Parwani, Rajkumar N

    2014-01-01

    Surgical crown lengthening helps to provide an adequate retention form for proper tooth preparation, thus enabling dentists to create esthetically pleasing and healthy restorations. Long-term stability requires accurate diagnosis and development of a comprehensive treatment plan in each case. This sequence of events stresses the importance of communication between the restorative dentist and the periodontist. This article presents 2 cases that involve surgical crown lengthening (including mucoperiosteal flap and ostectomy) for the restoration of teeth.

  15. Compensatory lengthening and structure preservation revisited yet again

    OpenAIRE

    Kavitskaya, Darya

    2017-01-01

    In their seminal paper, deChene (1979) make a strong claim that pre-existing vowel length contrast is a necessary condition for the phonologization of vowel length through compensatory lengthening. Compensatory lengthening is thus predicted to be always a structure-preserving change. Since that time, the claim has been challenged in numerous works (Gess 1998, Hock1986, Morin 1992), among others). A closer examination of the cited counterexamples to de Chene and Anderson's claim reveals certa...

  16. Mechanical lengthening in multiple intestinal segments in-series.

    Science.gov (United States)

    Scott, Andrew; Rouch, Joshua D; Huynh, Nhan; Chiang, Elvin; Shekherdimian, Shant; Lee, Steven L; Wu, Benjamin M; Dunn, James C Y

    2016-06-01

    Current models of mechanical intestinal lengthening employ a single device in an isolated segment. Here we demonstrate that polycaprolactone (PCL) springs can be deployed in-series to lengthen multiple intestinal segments simultaneously to further increase overall intestinal length. A Roux-en-y jejunojejunostomy with a blind Roux limb was created in the proximal jejunum of rats. Two encapsulated 10-mm PCL springs were placed in-series into the Roux limb and were secured with clips. After 4weeks, the lengthened segments were retrieved for histological analyses. Lengthening two intestinal segments simultaneously was achieved by placing two PCL springs in-series. The total combined length of the lengthened segments in-series was 45±4mm. The two jejunal segments with PCL springs (25±2 and 20±2mm) were significantly longer than control segments without the spring (14±1mm, p<0.05). Spring-mediated lengthening can be achieved using multiple springs placed sequentially. The use of the Roux-en-y surgical model allowed easy insertion of springs in a blind Roux limb and arrange them in-series. Combined with relengthening techniques, we can use these methods to increase the length of small intestine to reach clinical significance. 1 Experimental. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Tracer-monitored flow titrations.

    Science.gov (United States)

    Sasaki, Milton K; Rocha, Diogo L; Rocha, Fábio R P; Zagatto, Elias A G

    2016-01-01

    The feasibility of implementing tracer-monitored titrations in a flow system is demonstrated. A dye tracer is used to estimate the instant sample and titrant volumetric fractions without the need for volume, mass or peak width measurements. The approach was applied to spectrophotometric flow titrations involving variations of sample and titrant flow-rates (i.e. triangle programmed technique) or concentration gradients established along the sample zone (i.e. flow injection system). Both strategies required simultaneous monitoring of two absorbing species, namely the titration indicator and the dye tracer. Mixing conditions were improved by placing a chamber with mechanical stirring in the analytical path aiming at to minimize diffusional effects. Unlike most of flow-based titrations, the innovation is considered as a true titration, as it does not require a calibration curve thus complying with IUPAC definition. As an application, acidity evaluation in vinegars involving titration with sodium hydroxide was selected. Phenolphthalein and brilliant blue FCF were used as indicator and dye tracer, respectively. Effects of sample volume, titrand/titrant concentrations and flow rates were investigated aiming at improved accuracy and precision. Results were reliable and in agreement with those obtained by a reference titration procedure. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Determination of tungsten by amperometric redox titration with dichromate

    Energy Technology Data Exchange (ETDEWEB)

    Wuensch, G.; Aupers, R.; Kranich, R.

    1985-11-01

    Tungsten is reduced by an excess of Cr(II) in about 10 M HCl. This is technically simpler than the use of reductor columns or liquid amalgams. Titration with Fe(III) or Cr(VI) first consumes the excess of Cr(II) and then oxidizes W(V) to W(VI). The potentiometric response of metal electrodes to W(V) is slow but biamperometric indication at Esub(pol) = 0.2 V applies well. A mixture of W, Fe and Mo can be analyzed in a consecutive titration. Only Ti interferes. As compared to the reductometric titration of W(VI) with Cr(II) the method uses a stable titrant and avoids deairating of the sample solution. Sample preparations for ferrotungsten, steel and wolframite ore are described. (orig.).

  19. Iodine losses during Winkler titrations

    Science.gov (United States)

    Knapp, George P.; Stalcup, Marvel C.; Stanley, Robert J.

    1991-01-01

    An experiment designed to measure iodine loss during the aliquot version of the Winkler titration for dissolved oxygen in seawater shows that 0.01-0.03 ml l -1 equivalent oxygen is lost at typical oceanic concentrations in the method presently used. A standardization technique, which mimics that employed during the titration of seawater samples, compensates for this iodine loss throughout the oceanic range. This result, contradicting an earlier report by GREEN and CARRITT (1966, Analyst, 91, 207-208), demonstrates that the whole-bottle method of oxygen titration is not to be preferred over the aliquot method.

  20. Amperometric, Bipotentiometric, and Coulometric Titration.

    Science.gov (United States)

    Stock, John T.

    1980-01-01

    Discusses recent review articles in various kinds of titration. Also discusses new research in apparatus and methodology, acid-base reactions, precipitation and complexing reactions, oxidation-reduction reactions, and nomenclature. Cites 338 references. (CS)

  1. Rapid clozapine titration in treatment-refractory bipolar disorder.

    Science.gov (United States)

    Ifteni, Petru; Correll, Christoph U; Nielsen, Jimmi; Burtea, Victoria; Kane, John M; Manu, Peter

    2014-09-01

    Clozapine is effective in treatment-refractory bipolar disorder (BD). Guidelines recommend slow titration to prevent seizures, hypotension and myocarditis, but this stance is not supported by comparative data. To evaluate the safety and effectiveness of rapid clozapine titration in BD. Analysis of a consecutive cohort of treatment-refractory BD patients with mixed/manic episode admitted on alternate days to one of two units of a psychiatric hospital. On one unit, clozapine was started at 25mg followed by 25-50mg as needed every 6h (maximum=100mg/day) on day 1, followed by increases of 25-100mg/day. On the other unit, clozapine was initiated with 25mg in day 1, followed by increases of 25-50mg/day. The primary outcome was the number of days from starting clozapine until readiness for discharge, adjusted in logistic regression for the number of antipsychotics tried during the hospitalization, psychotropic co-treatments and presence of psychotic features. Patients subject to rapid (N=44) and standard (N=23) titration were similar in age, gender, smoking status, body mass index, illness severity at baseline and discharge, and highest clozapine dose. Clozapine was discontinued due to hypotension (N=1) and pneumonia (N=1) during rapid titration, and for excessive sedation (N=1) in each titration group. The number of hospital days from starting clozapine until readiness for discharge was 3.8 days shorter in the rapid titration group (12.7±6.3 vs. 16.5±5.8, p=0.0077). Rapid clozapine titration appeared safe and effective for treatment-refractory BD. The potential for shorter hospital stays justifies prospective trials of this method. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. [Intestinal lengthening techniques: an experimental model in dogs].

    Science.gov (United States)

    Garibay González, Francisco; Díaz Martínez, Daniel Alberto; Valencia Flores, Alejandro; González Hernández, Miguel Angel

    2005-01-01

    To compare two intestinal lengthening procedures in an experimental dog model. Intestinal lengthening is one of the methods for gastrointestinal reconstruction used for treatment of short bowel syndrome. The modification to the Bianchi's technique is an alternative. The modified technique decreases the number of anastomoses to a single one, thus reducing the risk of leaks and strictures. To our knowledge there is not any clinical or experimental report that studied both techniques, so we realized the present report. Twelve creole dogs were operated with the Bianchi technique for intestinal lengthening (group A) and other 12 creole dogs from the same race and weight were operated by the modified technique (Group B). Both groups were compared in relation to operating time, difficulties in technique, cost, intestinal lengthening and anastomoses diameter. There were no statistical difference in the anastomoses diameter (A = 9.0 mm vs. B = 8.5 mm, p = 0.3846). Operating time (142 min vs. 63 min) cost and technique difficulties were lower in group B (p anastomoses (of Group B) and intestinal segments had good blood supply and were patent along their full length. Bianchi technique and the modified technique offer two good reliable alternatives for the treatment of short bowel syndrome. The modified technique improved operating time, cost and technical issues.

  3. Influence of hamstring lengthening on muscle activation timing during gait

    NARCIS (Netherlands)

    Buurke, Jaap; Hermens, Hermanus J.; Roetenberg, D.; Harlaar, J.; Rosenbaum, D.; Kleissen, R.F.M.

    2004-01-01

    The purpose of this study was to describe the changes in muscle activation patterns using surface electromyography (sEMG) during walking in patients with cerebral palsy (CP), before and after hamstring lengthening. In the current clinical use of sEMG during walking in CP for pre-operative planning,

  4. Function of mechanically lengthened jejunum after restoration into continuity.

    Science.gov (United States)

    Sullins, Veronica F; Wagner, Justin P; Walthers, Christopher M; Chiang, Elvin K; Lee, Steven L; Wu, Benjamin M; Dunn, James C Y

    2014-06-01

    Distraction enterogenesis is a potential treatment for patients with short bowel syndrome. We previously demonstrated successful lengthening of jejunum using a degradable spring device in rats. Absorptive function of the lengthened jejunum after restoration into intestinal continuity needs to be determined. Encapsulated polycaprolactone springs were placed into isolated jejunal segments in rats for four weeks. Lengthened segments of jejunum were subsequently restored into intestinal continuity. Absorption studies were performed by placing a mixture of a non-absorbable substrate and glucose into the lumen of the restored jejunum. Restored jejunal segments demonstrated visible peristalsis at specimen retrieval. Compared to normal jejunal controls, restored segments demonstrated equal water absorption and greater glucose absorption. Restored segments had thicker smooth muscle, increased villus height, increased crypt depth, and decreased sucrase activity compared to normal jejunum. The density of enteric ganglia increased after restoration to near normal levels in the submucosa and to normal levels in the myenteric plexus. Jejunum lengthened with a degradable device demonstrates peristaltic and enzymatic activity as well as glucose and water absorption after restoration into intestinal continuity. Our findings further demonstrate the therapeutic potential of a degradable device. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Chitin Lengthens Power Production in a Sedimentary Microbial Fuel Cell

    Science.gov (United States)

    2014-01-01

    presented at the conference. DNA extraction, PCR-DGGE (denaturant gradient gel electrophoresis ) of 16 S ribosomal RNA gene, band excision and...are able to directly produce electrical energy by bacteria consuming biodegradable compounds in marine sediments. In sediments with low organic...organic carbon sediments demonstrate that chitin enhances and lengthens power production. Keywords—chitin; MFC; microbiology; iron-reducing bacteria

  6. On the JWKB solution of the uniformly lengthening pendulum via ...

    Indian Academy of Sciences (India)

    Common recipe for the lengthening pendulum (LP) involves some change of variables to give a relationship with the Bessel's equation. In this work, conventional semiclassical JWKB solution (named after Jeffreys, Wentzel, Kramers and Brillouin) of the LP is being obtained by first transforming the related Bessel's equation ...

  7. TAPIR: a device for automatic titration with incremental weighing of the titration reagent

    International Nuclear Information System (INIS)

    Ganivet, Michel

    TAPIR is a titration device enabling automatic analyses with weighting of the titration reagent. The titration method used can be based on potentiometry, amperometry, color indicator change... The reproducibility is about 3.10 -4 [fr

  8. Slow Meteors

    Science.gov (United States)

    Dubs, Martin; Sposetti, Stefano; Spinner, Roger; Booz, Beat

    2017-04-01

    Slow meteors are studied with video observations and spectroscopy. A comparison of their orbits and spectra points to a common origin. Although they do not belong to some meteor stream, they deserve to be studied in more detail. The present paper tries to make a first attempt to characterize the common properties of this class of meteors.

  9. Stretching skeletal muscle: chronic muscle lengthening through sarcomerogenesis.

    Directory of Open Access Journals (Sweden)

    Alexander M Zöllner

    Full Text Available Skeletal muscle responds to passive overstretch through sarcomerogenesis, the creation and serial deposition of new sarcomere units. Sarcomerogenesis is critical to muscle function: It gradually re-positions the muscle back into its optimal operating regime. Animal models of immobilization, limb lengthening, and tendon transfer have provided significant insight into muscle adaptation in vivo. Yet, to date, there is no mathematical model that allows us to predict how skeletal muscle adapts to mechanical stretch in silico. Here we propose a novel mechanistic model for chronic longitudinal muscle growth in response to passive mechanical stretch. We characterize growth through a single scalar-valued internal variable, the serial sarcomere number. Sarcomerogenesis, the evolution of this variable, is driven by the elastic mechanical stretch. To analyze realistic three-dimensional muscle geometries, we embed our model into a nonlinear finite element framework. In a chronic limb lengthening study with a muscle stretch of 1.14, the model predicts an acute sarcomere lengthening from 3.09[Formula: see text]m to 3.51[Formula: see text]m, and a chronic gradual return to the initial sarcomere length within two weeks. Compared to the experiment, the acute model error was 0.00% by design of the model; the chronic model error was 2.13%, which lies within the rage of the experimental standard deviation. Our model explains, from a mechanistic point of view, why gradual multi-step muscle lengthening is less invasive than single-step lengthening. It also explains regional variations in sarcomere length, shorter close to and longer away from the muscle-tendon interface. Once calibrated with a richer data set, our model may help surgeons to prevent muscle overstretch and make informed decisions about optimal stretch increments, stretch timing, and stretch amplitudes. We anticipate our study to open new avenues in orthopedic and reconstructive surgery and enhance

  10. Safety and tolerability of different titration rates of retigabine (ezogabine) in patients with partial-onset seizures.

    Science.gov (United States)

    Biton, Victor; Gil-Nagel, Antonio; Brodie, Martin J; Derossett, Sarah E; Nohria, Virinder

    2013-11-01

    Retigabine (RTG; international nonproprietary name)/ezogabine (EZG; US adopted name) is an antiepileptic drug (AED) that prolongs neuronal voltage-gated potassium-channel KCNQ2-5 (Kv 7.2-7.5) opening. This double-blind study evaluated different RTG/EZG dose-titration rates. Patients (N=73) with partial-onset seizures receiving concomitant AEDs were randomized to one of three titration groups, all of which were initiated at RTG/EZG 300mg/day divided into three equal doses. Fast-, medium-, and slow-titration groups received dose increments of 150mg/day every 2, 4, and 7 days, respectively, achieving the target dose of 1200mg/day after 13, 25, and 43 days, respectively. Safety assessments were performed throughout. Discontinuation rates due to treatment-emergent adverse events (TEAEs) were numerically higher in the fast- (10/23) and medium- (7/22) titration groups than in the slow-titration group (3/23) but statistical significance was achieved only for the high-titration group compared with the low-titration group (p=0.024). Stratified analysis, with concomitant AEDs divided into enzyme inducers (carbamazepine, phenytoin, oxcarbazepine) or noninducers, showed that the risk of discontinuation due primarily to TEAEs was significantly higher in the fast- (p=0.010) but not in the medium-titration group (p=0.078) when compared with the slow-titration group. Overall, the slow-titration rate appeared to be best tolerated and was used in further efficacy and safety studies with RTG/EZG. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. Proximal hamstring lengthening in the sitting cerebral palsy patient.

    Science.gov (United States)

    Elmer, E B; Wenger, D R; Mubarak, S J; Sutherland, D H

    1992-01-01

    We retrospectively studied 62 nonambulatory children with spastic quadriplegic cerebral palsy who underwent proximal hamstring lengthening to improve hip and spine positioning. Preoperatively, all had hamstring contracture, with difficulty sitting due to hip extensor thrust and increased kyphosis. Thirty-five patients with follow-up greater than or equal to 2 years were studied using a modified Reimer scale to assess sitting ability. Sitting ability improved significantly (p less than 0.01) postoperatively, along with popliteal angle (p less than 0.001) and straight leg raising (p less than 0.001). Proximal hamstring lengthening is effective in treating severe hamstring contractures in the wheelchair-bound child with cerebral palsy.

  12. Clubfoot posteromedial release: advantages of tibialis anterior tendon lengthening.

    Science.gov (United States)

    Wicart, Philippe R; Barthes, Xavier; Ghanem, Ismat; Seringe, Raphaël

    2002-01-01

    The aim of this study is to evaluate the eventual advantages of tibialis anterior (TA) tendon lengthening during clubfoot posteromedial release. A continuous series of 60 idiopathic clubfeet has been retrospectively studied. Tibialis anterior lengthening (TAL) began to be performed in 1984. Two groups of 30 feet have been distinguished: without TAL (before 1984) and with TAL (after 1984). There was no significant difference between the 2 groups concerning mean age at surgery, preoperative clinical and radiologic data. Mean postoperative follow-up was 10 years and minimal follow-up required was 5 years. TAL decreased Triceps surae relative insufficiency and improved monopodal jump. TAL balanced TA and peroneus longus, decreased dynamic supination and balanced forefoot pronation and supination. The feet without TAL presented lack of anteromedial support (20% without TAL, 0% with TAL) and medial arch cavus with dorsal talo-navicular subluxation (20% without TAL, 3,3% with TAL). TAL decreased the rate of recurrence and surgical revision.

  13. Calcaneal lengthening for planovalgus deformity in children with cerebral palsy.

    Science.gov (United States)

    Ettl, Volker; Wollmerstedt, Nicole; Kirschner, Stephan; Morrison, Robert; Pasold, Eva; Raab, Peter

    2009-05-01

    In children with cerebral palsy, planovalgus deformity of the foot is common. The aim of this study was to evaluate the outcome of calcaneal lengthening for the treatment of planovalgus foot deformity in children with cerebral palsy. We reviewed 19 children (28 feet) treated between 1996 and 2004 in our institution. There were 14 ambulating (19 feet) and 5 nonambulating children (9 feet). The average age of the children at time of surgery was 8.6 years. Followup averaged 4.3 years. We found satisfactory results in 75% of the feet clinically and in 79% radiologically according to Mosca's criteria. We saw no overcorrection but a relapse of the deformity in seven cases. There were six unsatisfactory radiological results, two (out of 19) in the ambulating and four (out of nine) in the nonambulating group. Ambulating children had a significantly better clinical and radiological outcome than nonambulating children (p = 0.042). A significant correlation was found between Ankle-hindfoot Score and clinical result according to Mosca's criteria (p = 0.001). In ambulatory children with cerebral palsy calcaneal lengthening is an effective procedure for the correction of mild to moderate planovalgus foot deformities. In nonambulatory children with severe plano-valgus deformities of the foot, calcaneal lengthening cannot be recommended because of the high relapse rate in these patients.

  14. Bunch lengthening in the SLC [Stanford Linear Collider] damping rings

    International Nuclear Information System (INIS)

    Bane, K.L.F.

    1990-02-01

    A high level of current dependent bunch lengthening has been observed on the North damping ring of the Stanford Linear Collider (SLC). At currents of 3 x 10 10 this behavior does not appear to degrade the machine's performance significantly. However, at the higher currents that are envisioned for the future one fears that its performance could be greatly degraded due to the phenomenon of bunch lengthening. This was the motivation for the work described in this paper. In this paper we calculate the longitudinal impedance of the damping ring vacuum chamber. More specifically, in this paper we find the response function of the ring to a short Gaussian bunch, which we call the Green function wake. In addition, we try to estimate the relative importance of the different vacuum chamber objects, in order to see how we might reduce the ring impedance. This paper also describes bunch length measurements performed on the North damping ring. We use the Green function wake, discussed above, to compute the bunch lengthening. Then we compare these results with those obtained from the measurements. In addition, we calculate the current dependence of the tune distribution

  15. Surgical crown lengthening: a 12-month study - radiographic results

    Directory of Open Access Journals (Sweden)

    Daniela Eleutério Diniz

    2007-08-01

    Full Text Available OBJECTIVE: The purpose of this study was to perform a radiographic follow-up evaluation after a 12-month healing period, following crown lengthening surgery. MATERIAL AND METHODS: Twenty-three periodontally healthy subjects (mean age 32.5 years that required crown lengthening surgery in premolars were recruited. In a total of 30 premolars, full thickness flaps, osseous resection, and flap suturing were performed. The restorative margin was defined in the pre-surgical phase and maintained unaltered during the healing period, serving as a reference point. Standardized bitewing radiographs were taken before and after osseous reduction, and at 2, 3, 6, and 12-month healing periods. RESULTS: Intact lamina dura was observed at both mesial and distal alveolar crests only from the 3rd month. At 12-months, all alveolar crests presented lamina dura. The overall mean distance from the restorative margin to the alveolar crest achieved after osseous resection was 3.28±0.87 mm at mesial and 2.81±0.51 mm at distal sites. No significant radiographic changes in the bone crest were observed during a 12-month healing period. CONCLUSION: The findings of this study suggest that the radiographic proximal bone level observed on bitewing radiographs following crown lengthening surgery can be used as a reference to predict the future level of the healed alveolar crest.

  16. Colorblindness and Titrations with Visual Indicators.

    Science.gov (United States)

    Diehl, Harvey; And Others

    1985-01-01

    Discusses various issues related to colorblind students performing titrations with visual indicators. Includes tables showing precisions in the titration of a weak acid by colorblind students using phenolphthalein and thymolphthalein and in the titration of a weak base by colorblind persons using methyl red and bromcresol green. (JN)

  17. EXPERIMENTAL APPROVAL OF COMBINED FIXATION FOR FEMUR LENGTHENING

    Directory of Open Access Journals (Sweden)

    M. A. Stepanov

    2017-01-01

    Full Text Available Elimination of congenital shortening of lower limb still remains a complex and unsolved orthopaedic task which requires an improved fixation technique as well as adjusted tactics of treatment and rehabilitation procedures.Purpose of the study — experimental approval of femur lengthening technique by external fixation with Ilizarov apparatus and internal fixation by plate.Materials and methods. Femur lengthening was performed in 6 mongrel dogs. Average animal age was 1,5±0,3 years, average weight — 20±5 kg, femur length — 22±2 sm. External apparatus with two supports and a titanium plate of an original design were applied under general anesthesia on the right femur of animals. Lengthening was performed manually at a rate of1 mm per day in 4 stages at a distance of 10% from initial segment length. External apparatus was removed on the last day of distraction after locking the plate. X-ray examination was done on the day of surgery, in 7, 14 and 25 days from the onset of distraction as well as in 14, 30, 60 and 90 days after completion of distraction and removal of external apparatus. Three animals were taken out of experiment in 30 days of fixation, remaining three animals — in 90 days. After euthanasia the authors performed autopsy of the organic femur complex and tissues contacting the plate.Results. The use of operated limb was not restricted during the whole distraction period. The authors observed first roentgenological signs of distraction osteogenesis on 7th day of lengthening. By the end of distraction period, at 25th day, shadows of regenerates demonstrated longitudinal striated structures in all cases. Median lucency area of 1–5 mm was located diagonally and across the regenerate or was intermittent. In 60 days of fixation X-rays demonstrated homogeneous regenerate. External fixation index was 13,9±1,5 days/sm (p≤0,05. The authors observed no cases of implants fracture or deformity during the experiment

  18. Rapid Inpatient Titration of Intravenous Treprostinil for Pulmonary Arterial Hypertension: Safe and Tolerable.

    Science.gov (United States)

    El-Kersh, Karim; Ruf, Kathryn M; Smith, J Shaun

    There is no standard protocol for intravenous treprostinil dose escalation. In most cases, slow up-titration is performed in the outpatient setting. However, rapid up-titration in an inpatient setting is an alternative that provides opportunity for aggressive treatment of common side effects experienced during dose escalation. In this study, we describe our experience with inpatient rapid up-titration of intravenous treprostinil. This was a single-center, retrospective study in which we reviewed the data of subjects with pulmonary arterial hypertension treated at our center who underwent inpatient rapid up-titration of intravenous treprostinil. Our treprostinil dose escalation protocol included initiation at 2 ng·kg·min with subsequent up-titration by 1 ng·kg·min every 6 to 8 hours as tolerated by side effects. A total of 16 subjects were identified. Thirteen subjects were treprostinil naive (naive group), and 3 subjects were receiving subcutaneous treprostinil but were hospitalized for further intravenous up-titration of treprostinil dose (nonnaive group). In the naive group, the median maximum dose achieved was 20 ng·kg·min with an interquartile range (IQR) of 20-23 ng·kg·min. The median up-titration interval was 6 days (IQR: 4-9). In the nonnaive group, the median maximum dose achieved was 20 ng·kg·min (range: 17-30). The median up-titration interval was 8.5 days (range: 1.5-11). Overall, the median maximum dose achieved was 20 ng·kg·min (IQR: 20-23.5), and the median up-titration interval was 6 days (IQR: 4.6-9.25), with no reported significant adverse hemodynamic events. In patients with pulmonary arterial hypertension, rapid inpatient titration of intravenous treprostinil is safe and tolerable.

  19. Automated back titration method to measure phosphate

    International Nuclear Information System (INIS)

    Comer, J.; Tehrani, M.; Avdeef, A.; Ross, J. Jr.

    1987-01-01

    Phosphate was measured in soda drinks and as an additive in flour, by a back titration method in which phosphate was precipitated with lanthanum, and the excess lanthanum was titrated with fluoride. All measurements were performed using the Orion fluoride electrode and the Orion 960 Autochemistry System. In most commercial automatic titrators, the inflection point of the titration curve, calculated from the first derivative of the curve, is used to find the equivalence polar of the titration. The inflection technique is compared with a technique based on Gran functions, which uses data collected after the end point and predicts the equivalence point accordingly

  20. Evaluation of an automatic uranium titration system

    International Nuclear Information System (INIS)

    Lewis, K.

    1980-01-01

    The titration system utilizes the constant current coulometric titration of Goldbeck and Lerner. U(VI) is reduced to U(IV) by Fe(II). V(V) is generated to titrate the U(IV), and the titration is followed potentiometrically. The evaluation shows that the recovery of uranium is 100% at the 40-mg level. The accuracy is generally +-0.10% or better. The smallest sample weight at which reliable results were obtained was 40 mg of uranium. Time for one analysis is 15 minutes. Advantages and disadvantages of the automated titrator are listed

  1. Automatic titrator for high precision plutonium assay

    International Nuclear Information System (INIS)

    Jackson, D.D.; Hollen, R.M.

    1986-01-01

    Highly precise assay of plutonium metal is required for accountability measurements. We have developed an automatic titrator for this determination which eliminates analyst bias and requires much less analyst time. The analyst is only required to enter sample data and start the titration. The automated instrument titrates the sample, locates the end point, and outputs the results as a paper tape printout. Precision of the titration is less than 0.03% relative standard deviation for a single determination at the 250-mg plutonium level. The titration time is less than 5 min

  2. Clozapine Titration for People in Early Psychosis: A Chart Review and Treatment Guideline.

    Science.gov (United States)

    Ballon, Jacob S; Ashfaq, Hera; Noordsy, Douglas L

    2018-06-01

    The use of clozapine, particularly in young people, is often limited by early treatment-emergent adverse effects including drowsiness and lethargy. Concerns about adverse effects, medication adherence, and the need for blood monitoring often impede the use of clozapine in this population, leading to repeated trials of less effective medications. Current clozapine dosing recommendations are based on people further in the course of their illness and thus reflect different responsiveness and sensitivities to antipsychotic medication. As such, there is a need for evidence-based guidelines for titration and dosing of clozapine among people in early psychosis. We performed a chart review of 14 people treated with clozapine within our early psychosis team. Data regarding dose titration, response, time to discontinuation, symptom severity, weight gain, and other adverse effects were gathered at clozapine initiation, 3 months, and last available visit on clozapine. People treated with slow titration within their first year of psychosis onset achieved sustained response at very low maintenance doses (mean dose = 81 mg/d, mean duration of treatment = 200 weeks) compared with slow titration with longer duration of illness (mean dose = 350 mg/d, mean duration of treatment = 68 weeks) or standard dose titration in early psychosis (mean dose = 112 mg/d, mean duration of treatment = 38 weeks). The most common adverse effects in all groups were weight gain and sedation, with the groups requiring higher mean doses reporting a broader range of adverse effects. There was no apparent difference in the clinical global impression for severity or improvement between the slow titration and standard titration groups in people with early psychosis. These observations are synthesized into a proposed treatment guideline for use of clozapine among people in early psychosis. We describe development of a slow titration approach to initiating clozapine among people in early psychosis. This

  3. Growth of the ulna after repeated bone lengthening in radial longitudinal deficiency.

    Science.gov (United States)

    Yoshida, Kiyoshi; Kawabata, Hidehiko; Wada, Mayuko

    2011-09-01

    Shortening of the ulna is one of the characteristic features of the radial longitudinal deficiency, which could be treated with repeated bone lengthening. The purpose of this study is to assess the changes in growth rate of the ulna after repeated bone lengthening in radial longitudinal deficiency. Five children (3 boys, 2 girls) who underwent twice bone lengthening of the ulna were reviewed. All patients had unilateral Bayne type IV radial longitudinal deficiency and had received centralization of the ulna previously. Ulnar length was measured on radiographs. Percent length against the normal side was used to measure differences between individuals. Ulnar growth rate was calculated as change in length over time. Ulnar length was 57.4% of the normal side on average at first visit to our hospitals. Percent length against the normal side became 88.9% immediately after the first lengthening. Then percent length decreased to 70.1% just before the second lengthening and became 101.7% after the second lengthening. Finally, it decreased to 82.9% at the last follow-up. Annual bone growth rate decreased after the first and second lengthening. Especially after the second lengthening, bone growth remarkably decreased. There were no complications except for pin-site infections at the first lengthening, whereas contracture of the elbow joint and callus fracture occurred at the second lengthening. Our study showed growth retardation occurred after bone lengthening and that the second lengthening resulted in remarkable growth retardation. We recommend delaying the second lengthening until the skeletal growth stops. Our series is small in number and we must investigate the influence of other factors (age, effect of the previous centralization, the amount of length, etc.). Further investigation will be needed to get firm conclusion. Level IV.

  4. Flexible lengthening-shortening arm mechanism for fishery resource management

    Directory of Open Access Journals (Sweden)

    Yoshiki Iwamochi

    2017-12-01

    Full Text Available The goal of this study was to use underwater robots instead of a diver’s observations to monitor and record the condition of an obstructed seabed in a shallow area. It is difficult to investigate marine resources that exist in deep water shaded by rock due to large and/or small rocks on the seabed. To solve these problems, we newly constructed a flexible lengthening-shortening arm with a small camera unit for an underwater robot to assist in the management of fishery resources. In this paper, we describe the concept and configuration of the newly developed arm mechanism using a sliding screw mechanism to overcome obstacles by changing arm posture in a two-dimensional plane, and we demonstrate the experimental results of a path-tracing controller for the rear links. The results were that the maximum deviations between the target path and the tracing path were less than 4.0% of the total width of the arm mechanism. These results suggest that the newly developed path-tracing algorithm is effective for our flexible lengthening-shortening arm mechanism.

  5. [Distraction Osteogenesis is an Effective Method to Lengthen Digits in Congenital Malformations].

    Science.gov (United States)

    Mann, M; Hülsemann, W; Winkler, F; Habenicht, R

    2016-02-01

    The aim of this study was to investigate the feasible amount of lengthening by distraction osteogenesis in congenital hand deficiencies. A total of 60 patients (1.6-17.8 years) underwent lengthening of 71 bones between 1994 and 2014. Bone lengthening was performed on 46 metacarpals and 25 phalanges. Mostly the first (n=30) and the fifth (n=21) rays were lengthened. Bone lengthening was performed to treat primarily symbrachydactyly (b=32) and amniotic band syndrome (n=10). To analyze the amount of lengthening preoperative radiographs and radiographs taken while removing the external fixator were compared. The charts were reviewed regarding age at surgery, duration of lengthening, duration of bony consolidation, complication, etc. The average of metacarpal distraction was 18.4 mm=73% lengthening with respect to the preoperative length; the average of phalange distraction was 14.0 mm=77% of the preoperative length. In both, metacarpals and phalanges, a lengthening of > 100% of the preoperative bone length was possible. In target length was reached in 89% of the procedures. The average time for consolidation was 6.1 (1-20) days/mm lengthening. The external fixator was in use on average for 140 (50-346) days. After removing of the external fixator an axial K-wire was used to stabilize the callus in 9 procedure, and an iliac bone craft plus axial K-wire in 11 procedures. The rate of complications was 30% (early consolidation, deviation, joint dislocation, pin infection, tendon dislocation). All complications could be treated without with acceptable results. Metacarpal and phalangeal distraction lengthening is an effective but demanding technique for ray reconstruction in congenital malformations of the hand. It is possible to lengthen a bone by more than 100%. Complications are common, but in most cases easy to handle. © Georg Thieme Verlag KG Stuttgart · New York.

  6. Brachymetatarsia of the fourth metatarsal, lengthening scarf osteotomy with bone graft

    Directory of Open Access Journals (Sweden)

    Ankit Desai

    2013-09-01

    Full Text Available A 16-year-old girl presented with left fourth metatarsal shortening causing significant psychological distress. She underwent lengthening scarf osteotomy held with an Omnitech® screw (Biotech International, France with the addition of two 1 cm cancellous cubes (RTI Biologics, United States. A lengthening z-plasty of the extensor tendons and skin were also performed. At 6 weeks the patient was fully weight bearing and at one-year follow up, the patient was satisfied and discharged. A modified technique of lengthening scarf osteotomy is described for congenital brachymatatarsia. This technique allows one stage lengthening through a single incision with graft incorporation by 6 weeks.

  7. Contributions to the theory of catalytic titrations-III Neutralization catalytic titrations.

    Science.gov (United States)

    Gaál, F F; Abramović, B F

    1985-07-01

    Neutralization catalytic titrations of weak monoprotic adds and bases with both volumetric and coulometric addition of the titrant (strong base/acid) have been simulated by taking into account the equilibrium concentration of the catalyst during the titration. The influence of several factors on the shape of the simulated catalytic titration curve has been investigated and is discussed.

  8. Nap-titration : An effective alternative for continuous positive airway pressure titration

    NARCIS (Netherlands)

    Hoekema, A; Stegenga, B; Meinesz, AF; van der Hoeven, JH; Wijkstra, PJ

    When treating Obstructive Steep Apnea-Hypopnea Syndrome (OSAHS) several alternatives for standard (manual) continuous positive airway pressure (CPAP) titration are feasible. A practical alternative is titration without polysomnography during an afternoon nap (Nap-titration). The aim of the present

  9. Lengthening of the storage life of cooled chicken through radurization

    International Nuclear Information System (INIS)

    Bok, H.E.; Holzapfel, W.H.

    1984-01-01

    Radurization is a particularly suitable method to lengthen the shelf life of chicken carcasses. A study was undertaken to determine the influence of four different dose rates and three storage temperatures, namely 3, 4, 5 and 7 kGy and 2, 4 and 8 degrees Celsius respectively. A total bacteria population of 10 6 per gramme was used as cut-off point for shelf life. Accordingly the untreated samples had a shelf life of 3 days at 4 degrees Celsius in comparison with 13 and 29 days for 3 and 5 kGy respectively. This study showed that low gamma radiation doses is not only an economical preservation method for chicken carcasses, but also destroys typical food pathogens such as Salmonella spp. The method also produces an organoleptic acceptable product

  10. Melorheostosis: complications of a tibial lengthening with the Ilizarov apparatus.

    Science.gov (United States)

    Griffet, J; el Hayek, T; Giboin, P

    1998-06-01

    Melorheostosis is a rare bone dysplasia, exceptionally described in childhood. It has been discovered in a 12-year-old boy who had a hemimelic affection associated with straw-berry skin marks. A 25 mm inequality of length of the lower limbs and a valgus deformation of the ankle resulting in a claudication and gonalgia requiring surgical correction. A reaxation and a progressive lengthening with the Ilizarov apparatus has been performed. Non-consolidation and a secondary bone infection led to the necessity of formation of a soleus flap. Consolidation and healing were finally obtained. In addition to vascular complications to be feared in this disease during surgical treatment, we have to take into consideration the absence of consolidation when the osteotomy is not performed on a safe bone.

  11. Green chemistry volumetric titration kit for pharmaceutical ...

    African Journals Online (AJOL)

    Stopcock SC and Spring Sp models of Econoburette (Calibrated, RTC (NR), Ministry of Small Scale Industries, Government of India), developed for semimicro volumetric titration of pharmaceutical formulations are reported. These are economized and risk free titration where pipette is replaced by an inbuilt pipette and ...

  12. A Tabular Approach to Titration Calculations

    Science.gov (United States)

    Lim, Kieran F.

    2012-01-01

    Titrations are common laboratory exercises in high school and university chemistry courses, because they are easy, relatively inexpensive, and they illustrate a number of fundamental chemical principles. While students have little difficulty with calculations involving a single titration step, there is a significant leap in conceptual difficulty…

  13. Tibial lengthening for unilateral Crowe type-IV developmental dysplasia of the hip

    Directory of Open Access Journals (Sweden)

    Jun Wan

    2014-01-01

    Conclusions: Tibial lengthening may effectively correct gait and satisfactorily improve body image in young patients with unilateral Crowe type-IV DDH. Mono-lateral external fixator allows for accelerated postoperative rehabilitation and optimal preservation of ankle movements. Lengthening along with intramedullary nails may significantly reduce the external fixation time and the risk of fixator-related complications.

  14. Effects of lengthening contraction on calcium kinetics and skeletal muscle contractility in humans

    DEFF Research Database (Denmark)

    Nielsen, J S; Madsen, K; Jørgensen, L V

    2005-01-01

    We have tested the hypothesis that the altered muscle contractility after lengthening contractions (LC) is caused by altered calcium (Ca2+) kinetics.......We have tested the hypothesis that the altered muscle contractility after lengthening contractions (LC) is caused by altered calcium (Ca2+) kinetics....

  15. Potentiometric Titration Method for Quantitative Determination of Hydrogen Peroxide

    National Research Council Canada - National Science Library

    Bessette, Russell R

    2005-01-01

    An electrochemical potentiometric titration method that entails titration of a known volume of a catholyte containing an unknown amount of hydrogen peroxide in a titration cell having two electrodes...

  16. Physeal growth arrest after tibial lengthening in achondroplasia: 23 children followed to skeletal maturity.

    Science.gov (United States)

    Song, Sang-Heon; Agashe, Mandar Vikas; Huh, Young-Jae; Hwang, Soon-Young; Song, Hae-Ryong

    2012-06-01

    Bilateral tibial lengthening has become one of the standard treatments for upper segment-lower segment disproportion and to improve quality of life in achondroplasia. We determined the effect of tibial lengthening on the tibial physis and compared tibial growth that occurred at the physis with that in non-operated patients with achondroplasia. We performed a retrospective analysis of serial radiographs until skeletal maturity in 23 achondroplasia patients who underwent bilateral tibial lengthening before skeletal maturity (lengthening group L) and 12 achondroplasia patients of similar height and age who did not undergo tibial lengthening (control group C). The mean amount of lengthening of tibia in group L was 9.2 cm (lengthening percentage: 60%) and the mean age at the time of lengthening was 8.2 years. The mean duration of follow-up was 9.8 years. Skeletal maturity (fusion of physis) occurred at 15.2 years in group L and at 16.0 years in group C. The actual length of tibia (without distraction) at skeletal maturity was 238 mm in group L and 277 mm in group C (p = 0.03). The mean growth rates showed a decrease in group L relative to group C from about 2 years after surgery. Physeal closure was most pronounced on the anterolateral proximal tibial physis, with relative preservation of the distal physis. Our findings indicate that physeal growth rate can be disturbed after tibial lengthening in achondroplasia, and a close watch should be kept for such an occurrence-especially when lengthening of more than 50% is attempted.

  17. FROM SLOW FOOD TO SLOW TOURISM

    Directory of Open Access Journals (Sweden)

    Bac Dorin Paul

    2014-12-01

    Full Text Available One of the effects of globalization is the faster pace of our lives. This rhythm can be noticed in all aspects of life: travel, work, shopping, etc. and it has serious negative effects. It has become common knowledge that stress and speed generate serious medical issues. Food and eating habits in the modern world have taken their toll on our health. However, some people took a stand and argued for a new kind of lifestyle. It all started in the field of gastronomy, where a new movement emerged – Slow Food, based on the ideas and philosophy of Carlo Petrini. Slow Food represents an important adversary to the concept of fast food, and is promoting local products, enjoyable meals and healthy food. The philosophy of the Slow Food movement developed in several directions: Cittaslow, slow travel and tourism, slow religion and slow money etc. The present paper will account the evolution of the concept and its development during the most recent years. We will present how the philosophy of slow food was applied in all the other fields it reached and some critical points of view. Also we will focus on the presence of the slow movement in Romania, although it is in a very early stage of development. The main objectives of the present paper are: to present the chronological and ideological evolution of the slow movement; to establish a clear separation of slow travel and slow tourism, as many mistake on for the other; to review the presence of the slow movement in Romania. Regarding the research methodology, information was gathered from relevant academic papers and books and also from interviews and discussions with local entrepreneurs. The research is mostly theoretical and empirical, as slow food and slow tourism are emerging research themes in academic circles.

  18. Non-aqueous titration of hydroxamic acids.

    Science.gov (United States)

    Stamey, T W; Christian, R

    1966-01-01

    Benzohydroxamic acid is titrated with 0.1M tetrabutyl-anunonium hydroxide in nine non-aqueous solvents with three different indicating electrodes. The best results are obtained using dimethylformamide as solvent and platinum-platinum electrodes. Four monoprotic and three diprotic hydroxamie acids and iron(III) benzohydroxamate have been successfully titrated with this system. The effect of quantitative additions of carbon dioxide to the titrant on its apparent molarity are found to be dependent on the amount added, the strength and sample size of acid titrated and the solvent used.

  19. Lengthening Temporalis Myoplasty for Single-Stage Smile Reconstruction in Children with Facial Paralysis.

    Science.gov (United States)

    Panossian, Andre

    2016-04-01

    Free muscle transfer for dynamic smile reanimation in facial paralysis is not always predictable with regard to cosmesis. Hospital stays range from 5 to 7 days. Prolonged operative times, longer hospital stays, and excessive cheek bulk are associated with free flap options. Lengthening temporalis myoplasty offers single-stage smile reanimation with theoretical advantages over free tissue transfer. From 2012 to 2014, 18 lengthening temporalis myoplasties were performed in 14 children for smile reconstruction. A retrospective chart review was completed for demographics, operative times, length of hospital stay, and perioperative complications. Fourteen consecutive patients with complete facial paralysis were included. Four patients underwent single-stage bilateral reconstruction, and 10 underwent unilateral procedures. Diagnoses included Möbius syndrome (n = 5), posterior cranial fossa tumors (n = 4), posttraumatic (n = 2), hemifacial microsomia (n = 1), and idiopathic (n = 2). Average patient age was 10.1 years. Average operative time was 410 minutes (499 minutes for bilateral lengthening temporalis myoplasty and 373 for unilateral lengthening temporalis myoplasty). Average length of stay was 3.3 days (4.75 days for bilateral lengthening temporalis myoplasty and 2.8 for unilateral lengthening temporalis myoplasty). Nine patients required minor revisions. Lengthening temporalis myoplasty is a safe alternative to free tissue transfer for dynamic smile reconstruction in children with facial paralysis. Limited donor-site morbidity, shorter operative times, and shorter hospital stays are some benefits over free flap options. However, revisions are required frequently secondary to tendon avulsions and adhesions. Therapeutic, IV.

  20. Radial forcing and Edgar Allan Poe's lengthening pendulum

    Science.gov (United States)

    McMillan, Matthew; Blasing, David; Whitney, Heather M.

    2013-09-01

    Inspired by Edgar Allan Poe's The Pit and the Pendulum, we investigate a radially driven, lengthening pendulum. We first show that increasing the length of an undriven pendulum at a uniform rate does not amplify the oscillations in a manner consistent with the behavior of the scythe in Poe's story. We discuss parametric amplification and the transfer of energy (through the parameter of the pendulum's length) to the oscillating part of the system. In this manner, radial driving can easily and intuitively be understood, and the fundamental concept applied in many other areas. We propose and show by a numerical model that appropriately timed radial forcing can increase the oscillation amplitude in a manner consistent with Poe's story. Our analysis contributes a computational exploration of the complex harmonic motion that can result from radially driving a pendulum and sheds light on a mechanism by which oscillations can be amplified parametrically. These insights should prove especially valuable in the undergraduate physics classroom, where investigations into pendulums and oscillations are commonplace.

  1. Complexometric titration of lanthanides and yttrium

    International Nuclear Information System (INIS)

    Ionashiro, M.; Graner, C.A.F.; Zuanon Netto, J.

    1983-01-01

    The pH variation of the solution and the ammonium acetate buffering were studied when different quantities of lanthanides and yttrium were titrated with EDTA, and xylenol orange as indicator. (Author) [pt

  2. Impact of leg lengthening on viscoelastic properties of the deep fascia

    Science.gov (United States)

    Wang, Hai-Qiang; Wei, Yi-Yong; Wu, Zi-Xiang; Luo, Zhuo-Jing

    2009-01-01

    Background Despite the morphological alterations of the deep fascia subjected to leg lengthening have been investigated in cellular and extracellular aspects, the impact of leg lengthening on viscoelastic properties of the deep fascia remains largely unknown. This study aimed to address the changes of viscoelastic properties of the deep fascia during leg lengthening using uniaxial tensile test. Methods Animal model of leg lengthening was established in New Zealand white rabbits. Distraction was initiated at a rate of 1 mm/day and 2 mm/day in two steps, and preceded until increases of 10% and 20% in the initial length of tibia had been achieved. The deep fascia specimens of 30 mm × 10 mm were clamped with the Instron 1122 tensile tester at room temperature with a constant tensile rate of 5 mm/min. After 5 load-download tensile tests had been performed, the specimens were elongated until rupture. The load-displacement curves were automatically generated. Results The normal deep fascia showed typical viscoelastic rule of collagenous tissues. Each experimental group of the deep fascia after leg lengthening kept the properties. The curves of the deep fascia at a rate of 1 mm/day with 20% increase in tibia length were the closest to those of normal deep fascia. The ultimate tension strength and the strain at rupture on average of normal deep fascia were 2.69 N (8.97 mN/mm2) and 14.11%, respectively. The increases in ultimate tension strength and strain at rupture of the deep fascia after leg lengthening were statistically significant. Conclusion The deep fascia subjected to leg lengthening exhibits viscoelastic properties as collagenous tissues without lengthening other than increased strain and strength. Notwithstanding different lengthening schemes result in varied viscoelastic properties changes, the most comparable viscoelastic properties to be demonstrated are under the scheme of a distraction rate of 1 mm/day and 20% increase in tibia length. PMID:19698092

  3. Theory of titration curves-VII The properties of derivative titration curves for strong acid-strong base and other isovalent ion-combination titrations.

    Science.gov (United States)

    Meites, T; Meites, L

    1970-06-01

    This paper deals with isovalent ion-combination titrations based on reactions that can be represented by the equation M(n+) + X(n-) --> MX, where the activity of the product MX is invariant throughout a titration, and with the derivative titration curves obtained by plotting d[M(+)]/dfversus f for such titrations. It describes some of the ways in which such curves can be obtained; it compares and contrasts them both with potentiometric titration curves, which resemble them in shape, and with segmented titration curves, from which they are derived; and it discusses their properties in detail.

  4. Lengthened cold stratification improves bulk whitebark pine germination

    Science.gov (United States)

    Nathan Robertson; Kent Eggleston; Emily Overton; Marie McLaughlin

    2013-01-01

    Crucial to the restoration of whitebark pine (Pinus albicaulis) ecosystems is the ability of forest managers to locate, propagate, and reintroduce viable, disease-resistant populations to these jeopardized systems. Currently, one of the most limiting steps in this process is the slow, labor-in - tensive, and expensive process of producing whitebark seedlings at forest...

  5. Bunch lengthening calculations for the SLC [Stanford Linear Collider] damping rings

    International Nuclear Information System (INIS)

    Bane, K.L.F.; Ruth, R.D.

    1989-03-01

    The problem of bunch lengthening in electron storage rings has been treated by many people, and there have been many experiments. In the typical experiment, the theory is used to determine the impedance of the ring. What has been lacking thus far, however, is a calculation of bunch lengthening that uses a carefully calculated ring impedance (or wakefield). In this paper we begin by finding the potential well distortion due to some very simple impedance models, in order to illustrate different types of bunch lengthening behavior. We then give a prescription for extending potential well calculations into the turbulent regime once the threshold is known. Then finally, using the wakefield calculated for the SLC damping rings, combined with the measured value of the threshold, we calculate bunch lengthening for the damping rings, and compare the results with the measurements. 9 refs., 6 figs

  6. Plutonium titration by controlled potential coulometry

    International Nuclear Information System (INIS)

    Leguay, N.

    2011-01-01

    The LAMMAN (Nuclear Materials Metrology Laboratory) is the support laboratory of the CETAMA (Analytical Method Committee), whose two main activities are developing analytic methods, and making and characterizing reference materials. The LAMMAN chose to develop the controlled potential coulometry because it is a very accurate analytical technique which allows the connection between the quantity of element electrolysed to the quantity of electricity measured thanks to the Faraday's law: it does not require the use of a chemical standard. This method was first used for the plutonium titration and was developed in the Materials Analysis and Metrology Laboratory (LAMM), for upgrading its performances and developing it to the titration of other actinides. The equipment and the material used were developed to allow the work in confined atmosphere (in a glove box), with all the restrictions involved. Plutonium standard solutions are used to qualify the method, and in particular to do titrations with an uncertainty better than 0.1 %. The present study allowed making a bibliographic research about controlled potential coulometry applied to the actinides (plutonium, uranium, neptunium, americium and curium). A full procedure was written to set all the steps of plutonium titration, from the preparation of samples to equipments storage. A method validation was done to check the full procedure, and the experimental conditions: working range, uncertainty, performance... Coulometric titration of the plutonium from pure solution (without interfering elements) was developed to the coulometric titration of the plutonium in presence of uranium, which allows to do accurate analyses for the analyses of some parts of the reprocessing of the spent nuclear fuel. The possibility of developing this method to other actinides than plutonium was highlighted thanks to voltammetric studies, like the coulometric titration of uranium with a working carbon electrode in sulphuric medium. (author)

  7. Coulometric titration at low temperatures-nonstoichiometric silver selenide

    OpenAIRE

    Beck, Gesa K.; Janek, Jürgen

    2003-01-01

    A modified coulometric titration technique is described for the investigation of nonstoichiometric phases at low temperatures. It allows to obtain titration curves at temperatures where the conventional coulometric titration technique fails because of too small chemical diffusion coefficients of the mobile component. This method for indirect coulometric titration is applied to silver selenide between -100 and 100 °C. The titration curves are analyzed on the basis of a defect chemical model an...

  8. Elimination of a "Gummy Smile" With Crown Lengthening and Lip Repositioning.

    Science.gov (United States)

    Mahn, Douglas H

    2016-01-01

    Excessive gingival display is considered unattractive by many patients. A combination of surgical approaches may be required to correct this problem. Clinical crown lengthening involves recontouring crestal bone levels and moving the gingival margin in an apical direction. Lip repositioning reduces gingival display by limiting upper lip movement when smiling. This article describes a case in which a combination of clinical crown lengthening and lip repositioning was used to correct excessive gingival display when smiling.

  9. Does arm lengthening affect the functional outcome in onlay reverse shoulder arthroplasty?

    Science.gov (United States)

    Werner, Birgit S; Ascione, Francesco; Bugelli, Giulia; Walch, Gilles

    2017-12-01

    The concept of onlay design reverse shoulder arthroplasty has been introduced to overcome complications observed with the traditional Grammont-type prosthesis. The aim of this study was to determine the influence of arm lengthening on the short-term clinical outcome in onlay reverse shoulder arthroplasty and investigate the effect of humeral tray offset positioning on arm lengthening and range of motion. We retrospectively evaluated 56 patients undergoing reverse shoulder arthroplasty with the Aequalis Ascend Flex prosthesis (Tornier, Bloomington, MN, USA) at a minimum 2 years' follow-up. Arm lengthening was determined using bilateral scaled radiographs of the entire humerus. The Constant score and active range of motion were documented preoperatively and postoperatively. The relationship between arm lengthening, humeral tray offset position, and functional outcome was analyzed. The Constant score improved from 25.5 ± 9.5 points to 71.5 ± 13.8 points at a mean follow-up of 30.1 ± 5.2 months. Mean postoperative anterior elevation was 145.2° ± 21.1°, and external rotation was 30.7° ± 20.3°. Arm lengthening exceeding 2.5 cm was related to a decrease in anterior elevation. We found a relationship between arm lengthening averaging 2.2 ± 1.7 cm and increased Constant score values. Humeral tray positioning demonstrated no influence on the functional outcome. There was a trend toward increased arm lengthening in lateral offset positioning. Onlay reverse shoulder arthroplasty yields good short-term clinical results. In our population, arm lengthening averaging 1 to 2.5 cm was found to be the best compromise on postoperative range of motion. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  10. Clinical Results and Complications of Lower Limb Lengthening for Fibular Hemimelia

    OpenAIRE

    Mishima, Kenichi; Kitoh, Hiroshi; Iwata, Koji; Matsushita, Masaki; Nishida, Yoshihiro; Hattori, Tadashi; Ishiguro, Naoki

    2016-01-01

    Abstract Fibular hemimelia is a rare but the most common congenital long bone deficiency, encompassing a broad range of anomalies from isolated fibular hypoplasia up to substantial femoral and tibial shortening with ankle deformity and foot deficiency. Most cases of fibular hemimelia manifest clinically significant leg length discrepancy (LLD) with time that requires adequate correction by bone lengthening for stable walking. Bone lengthening procedures, especially those for pathological bone...

  11. Clinical Results and Complications of Lower Limb Lengthening for Fibular Hemimelia: A Report of Eight Cases.

    Science.gov (United States)

    Mishima, Kenichi; Kitoh, Hiroshi; Iwata, Koji; Matsushita, Masaki; Nishida, Yoshihiro; Hattori, Tadashi; Ishiguro, Naoki

    2016-05-01

    Fibular hemimelia is a rare but the most common congenital long bone deficiency, encompassing a broad range of anomalies from isolated fibular hypoplasia up to substantial femoral and tibial shortening with ankle deformity and foot deficiency. Most cases of fibular hemimelia manifest clinically significant leg length discrepancy (LLD) with time that requires adequate correction by bone lengthening for stable walking. Bone lengthening procedures, especially those for pathological bones, are sometimes associated with severe complications, such as delayed consolidation, fractures, and deformities of the lengthened bones, leading to prolonged healing time and residual LLD at skeletal maturity. The purpose of this study was to review our clinical results of lower limb lengthening for fibular hemimelia.This study included 8 Japanese patients who diagnosed with fibular hemimelia from physical and radiological findings characteristic of fibular hemimelia and underwent single or staged femoral and/or tibial lengthening during growth or after skeletal maturity. LLD, state of the lengthened callus, and bone alignment were evaluated with full-length radiographs of the lower limb. Previous interventions, associated congenital anomalies, regenerate fractures were recorded with reference to medical charts and confirmed on appropriate radiographs. Successful lengthening was defined as the healing index <50 days/cm without regenerate fractures.A significant difference was observed in age at surgery between successful and unsuccessful lengthening. The incidence of regenerate fractures was significantly correlated with callus maturity before frame removal. LLD was corrected within 11 mm, whereas mechanical axis deviated laterally.Particular attention should be paid to the status of callus maturation and the mechanical axis deviation during the treatment period in fibular hemimelia.

  12. End-point construction and systematic titration error in linear titration curves-complexation reactions

    NARCIS (Netherlands)

    Coenegracht, P.M.J.; Duisenberg, A.J.M.

    The systematic titration error which is introduced by the intersection of tangents to hyperbolic titration curves is discussed. The effects of the apparent (conditional) formation constant, of the concentration of the unknown component and of the ranges used for the end-point construction are

  13. ASSESSMENT OF ATTENTION THRESHOLD IN RATS BY TITRATION OF VISUAL CUE DURATION DURING THE FIVE CHOICE SERIAL REACTION TIME TASK

    Science.gov (United States)

    Martin, Thomas J.; Grigg, Amanda; Kim, Susy A.; Ririe, Douglas G.; Eisenach, James C.

    2014-01-01

    Background The 5 choice serial reaction time task (5CSRTT) is commonly used to assess attention in rodents. We sought to develop a variant of the 5CSRTT that would speed training to objective success criteria, and to test whether this variant could determine attention capability in each subject. New Method Fisher 344 rats were trained to perform a variant of the 5CSRTT in which the duration of visual cue presentation (cue duration) was titrated between trials based upon performance. The cue duration was decreased when the subject made a correct response, or increased with incorrect responses or omissions. Additionally, test day challenges were provided consisting of lengthening the intertrial interval and inclusion of a visual distracting stimulus. Results Rats readily titrated the cue duration to less than 1 sec in 25 training sessions or less (mean ± SEM, 22.9 ± 0.7), and the median cue duration (MCD) was calculated as a measure of attention threshold. Increasing the intertrial interval increased premature responses, decreased the number of trials completed, and increased the MCD. Decreasing the intertrial interval and time allotted for consuming the food reward demonstrated that a minimum of 3.5 sec is required for rats to consume two food pellets and successfully attend to the next trial. Visual distraction in the form of a 3 Hz flashing light increased the MCD and both premature and time out responses. Comparison with existing method The titration variant of the 5CSRTT is a useful method that dynamically measures attention threshold across a wide range of subject performance, and significantly decreases the time required for training. Task challenges produce similar effects in the titration method as reported for the classical procedure. Conclusions The titration 5CSRTT method is an efficient training procedure for assessing attention and can be utilized to assess the limit in performance ability across subjects and various schedule manipulations. PMID

  14. An accurate potentiometric titration of 5-25 mg uranium

    International Nuclear Information System (INIS)

    Slanina, J.; Bakker, F.; Lingerak, W.A.

    1976-01-01

    A potentiometric titration of 5 to 25 mg uranium is described. Sulphamic and phosphoric acid are added to the sample (volume 1 ml), U VI is reduced to U IV by Fe 2+ and the excess of Fe 2+ is oxidized by a mixture of nitric acid, sulphamic acid and ammonium molybdate; vanadyl sulphate is added to ensure a sharp end-point of the titration. The resultant U IV is titrated automatically with 0.02500N potassiumdichromate using a platinum indicator electrode. The automatic titration is performed both with a commercial titrator (Mettler) and with an R.C.N. titrator which waits after each addition until the equilibrium is reached. Using the Mettler titrator an accuracy of 0.05% relative was reached. The R.C.N. setpoint titrator gave results with an accuracy of 0.04% relative at the 20-mg U level. Each titration takes 5 to 7 min. (author)

  15. AUTOMATION OF POTENTIOMETRIC TITRATION WITH A ...

    African Journals Online (AJOL)

    An IBM compatible interface card system with infrared source-detector data sampling was designed and tested for automation of potentiometric titrations with personal computers without continuous measurement of the volume of the titrant. The device with other appropriate apparatus and setup was tested for determination ...

  16. Titrated Misoprostol Versus Dinoprostone for Labor Induction

    African Journals Online (AJOL)

    . Studied women were randomized into; Group I: 104 women included and received oral 200 µg misoprostol in 200 ml water titrated over 12 h and Group II: 108 women included and received vaginal dinoprostone tablet (3 mg) maximum two ...

  17. Isothermal Titration Calorimetry in the Student Laboratory

    Science.gov (United States)

    Wadso, Lars; Li, Yujing; Li, Xi

    2011-01-01

    Isothermal titration calorimetry (ITC) is the measurement of the heat produced by the stepwise addition of one substance to another. It is a common experimental technique, for example, in pharmaceutical science, to measure equilibrium constants and reaction enthalpies. We describe a stirring device and an injection pump that can be used with a…

  18. Titration Calculations with Computer Algebra Software

    Science.gov (United States)

    Lachance, Russ; Biaglow, Andrew

    2012-01-01

    This article examines the symbolic algebraic solution of the titration equations for a diprotic acid, as obtained using "Mathematica," "Maple," and "Mathcad." The equilibrium and conservation equations are solved symbolically by the programs to eliminate the approximations that normally would be performed by the student. Of the three programs,…

  19. NBL-Davies-Gray weight titration method

    International Nuclear Information System (INIS)

    Hassell, C.

    1981-01-01

    The titration method for uranium consists of the following basic steps: reduction of U +6 to U +4 by Fe +2 ; selective oxidation of excess Fe +2 by HNO 3 with Mo +6 catalyst, all in strong phosphoric acid solution; and titration of the U +4 with standard dichromate after dilution. In this paper, detailed procedure of the NBL method, its modification to a gravimetric system or weight titration technique, and miniaturization of the NBL titrimetric method are discussed. Improved precisions and accuracy (2 to 3 times), of the gravimetric titrant delivery has made it possible to reduce the amount of uranium taken for each analysis. At present, using gravimetric delivery, most samples are titrated in the 30 to 50 mg range. Improved precision has led to investigating the possibility of a scaled-down version of the basic method so as to reduce the volume of phosphoric acid waste generated. Because all reactions are carried out in the same vessel, this method can be automated. Analysts at NBL have been able to restrict error to 0.05% or better in the 30 to 100 mg range using the basic procedure

  20. Coulometric titration of ketotifen in tablets.

    Science.gov (United States)

    Ciesielski, W; Zakrzewski, R; Złobińska, U

    2005-03-01

    A method for the determination of ketotifen involving its reaction with iodine in an alkaline medium is presented. In coulometric titration using biamperometric end-point detection 0.25-2 micromol (77-618 microg) of ketotifen was successfully determined. The elaborated method was applied to the determination of ketotifen in drugs.

  1. Force generation examined by laser temperature-jumps in shortening and lengthening mammalian (rabbit psoas) muscle fibres.

    Science.gov (United States)

    Ranatunga, K W; Coupland, M E; Pinniger, G J; Roots, H; Offer, G W

    2007-11-15

    We examined the tension change induced by a rapid temperature jump (T-jump) in shortening and lengthening active muscle fibres. Experiments were done on segments of permeabilized single fibres (length (L0) approximately 2 mm, sarcomere length 2.5 microm) from rabbit psoas muscle; [MgATP] was 4.6 mm, pH 7.1, ionic strength 200 mm and temperature approximately 9 degrees C. A fibre was maximally Ca2+-activated in the isometric state and a approximately 3 degrees C, rapid ( 0.05 L0 s(-1), whereas the tension decreased to about < 0.5 x P0 during shortening at 0.1-0.2 L0 s(-1); the unloaded shortening velocity was approximately 1 L0 s(-1) and the curvature of the force-shortening velocity relation was high (a/P0 ratio from Hill's equation of approximately 0.05). In isometric state, a T-jump induced a tension rise of 15-20% to a new steady state; by curve fitting, the tension rise could be resolved into a fast (phase 2b, 40-50 s(-1)) and a slow (phase 3, 5-10 s(-1)) exponential component (as previously reported). During steady lengthening, a T-jump induced a small instantaneous drop in tension, followed by recovery, so that the final tension recorded with and without a T-jump was not significantly different; thus, a T-jump did not lead to a net increase of tension. During steady shortening, the T-jump induced a pronounced tension rise and both its amplitude and the rate (from a single exponential fit) increased with shortening velocity; at 0.1-0.2 L0 s(-1), the extent of fibre shortening during the T-jump tension rise was estimated to be approximately 1.2% L(0) and it was shorter at lower velocities. At a given shortening velocity and over the temperature range of 8-30 degrees C, the rate of T-jump tension rise increased with warming (Q10 approximately 2.7), similar to phase 2b (endothermic force generation) in isometric muscle. Results are discussed in relation to the previous findings in isometric muscle fibres which showed that a T-jump promotes an early step in the

  2. An Olfactory Indicator for Acid-Base Titrations.

    Science.gov (United States)

    Flair, Mark N.; Setzer, William N.

    1990-01-01

    The use of an olfactory acid-base indicator in titrations for visually impaired students is discussed. Potential olfactory indicators include eugenol, thymol, vanillin, and thiophenol. Titrations performed with each indicator with eugenol proved to be successful. (KR)

  3. Microculture virus titration--a simple colourimetric assay for influenza virus titration.

    Science.gov (United States)

    Levi, R; Beeor-Tzahar, T; Arnon, R

    1995-03-01

    Influenza antigens can be detected by several well established methods. However, when it is important to determine the titre of infective virions, a bioassay should be employed. The standard and the most widely used tests for influenza infectivity are titration carried out in embryonated hen eggs, or the plaque assay employing tissue culture techniques. A simple colourimetric assay for influenza virus detection and titration is described. Samples of allantoic fluid or mice lung homogenates were used to infect MDCK cultures in microplate wells. After an incubation period, the tetrazolium (MTT) colourimetric assay was used to determine cell viability, and when compared to untreated culture control enabled the detection and titration of several influenza strains. When samples were assayed simultaneously in embryonated eggs and by the MCVT method, good correlation in determined titres was obtained. The availability of an additional method for influenza titration allows more flexibility in the choice of titration method according to the specific needs of the study. Furthermore, this method lends itself to full automatization. Similar procedures should also be applicable to titration of other cytopathic viruses.

  4. Ion-selective electrodes in potentiometric titrations; a new method for processing and evaluating titration data.

    Science.gov (United States)

    Granholm, Kim; Sokalski, Tomasz; Lewenstam, Andrzej; Ivaska, Ari

    2015-08-12

    A new method to convert the potential of an ion-selective electrode to concentration or activity in potentiometric titration is proposed. The advantage of this method is that the electrode standard potential and the slope of the calibration curve do not have to be known. Instead two activities on the titration curve have to be estimated e.g. the starting activity before the titration begins and the activity at the end of the titration in the presence of large excess of titrant. This new method is beneficial when the analyte is in a complexed matrix or in a harsh environment which affects the properties of the electrode and the traditional calibration procedure with standard solutions cannot be used. The new method was implemented both in a method of linearization based on the Grans's plot and in determination of the stability constant of a complex and the concentration of the complexing ligand in the sample. The new method gave accurate results when using titrations data from experiments with samples of known composition and with real industrial harsh black liquor sample. A complexometric titration model was also developed. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Potentiometric determination of milligram amounts of uranium by semiautomatic titrator

    International Nuclear Information System (INIS)

    Ryzhinskij, M.V.; Stepanov, A.V.; Preobrazhenskaya, L.D.; Solntseva, L.F.; Gromova, E.A.

    1978-01-01

    A semiautomatic titrator is described which allows gravimetriotentiometricc-p titrat mg amounts of substances. Milligram amounts of uranium (absolute contents and oxygen/uranium ratio) in U 3 O 8 were determined as an example of the titrator action. The relative standard deviation was less than 0.001

  6. Simple and Automated Coulometric Titration of Acid Using Nonisolated Electrodes

    Science.gov (United States)

    Kuntzleman, Thomas S.; Kenney, Joshua B.; Hasbrouck, Scott; Collins, Michael J.; Amend, John R.

    2011-01-01

    Coulometric titrations involve the quantification of analyte by measurements of current and time. In most coulometric titrations, the anode and cathode are placed in isolated cells that are connected by a salt bridge. By contrast, the experiments described here involve coulometric titrations (of acidic protons in solution) using a silver anode and…

  7. Safe Cosmetic Leg Lengthening for Short Stature: Long-term Outcomes.

    Science.gov (United States)

    Elbatrawy, Yasser; Ragab, Ibrahim Mohammed A

    2015-07-01

    It is well known that limb lengthening is performed to treat limb-length discrepancies resulting from congenital anomalies and developmental problems. However, few studies discuss lengthening for cosmetic purposes. The current authors conducted a prospective study with long-term follow-up. From July 2002 through June 2007, 133 patients requested that their height be increased. Fifty-two were approved to undergo limb-lengthening surgery. Two were lost to final follow-up, leaving 50 in the study group. For all patients, the Ilizarov ring external fixator was applied with a maximum-stability technique that achieved frame stability and allowed patients to ambulate with a walker from the first week postoperatively. The method requires close follow-up for early detection of problems. Physiotherapy improved ankle function and prevented plantar flexion deformity, which can occur during lengthening. Excellent final outcomes were achieved in all patients except one, who required additional surgery. The Ilizarov device is a safe tool for limb lengthening in individuals of short stature when applied with the authors' maximum stability technique. To the authors' knowledge, this is the first article on this topic to report long-term results (minimum 5-year follow-up for all patients). Many factors influence the outcome of lengthening surgery performed with Ilizarov devices: the material of the rings, the use of a hybrid technique combining pins and wires, the diameter and number of pins over each bone segment, the size of the rings around the limb, the surgical technique for pin insertion, and the use of hydroxyapatite-coated pins or regular stainless pins. Copyright 2015, SLACK Incorporated.

  8. Limb lengthening in children with Russell-Silver syndrome: a comparison to other etiologies.

    Science.gov (United States)

    Goldman, V; McCoy, T H; Harbison, M D; Fragomen, A T; Rozbruch, S R

    2013-03-01

    Russell-Silver syndrome (RSS) is the combination of intrauterine growth retardation, difficulty feeding, and postnatal growth retardation. Leg length discrepancy (LLD) is one of four major diagnostic criteria of RSS and is present in most cases. We aimed to ascertain whether pediatric RSS patients will adequately consolidate bony regenerate following leg lengthening. We retrospectively reviewed pediatric RSS patients who underwent limb lengthening and compared them to a similar group of patients with LLD resulting from tumor, trauma, or congenital etiology. The primary outcome measurement was the bone healing index (BHI). The RSS group included seven lengthened segments in five patients; the comparison group included 21 segments in 19 patients. The groups had similar lengthening amounts (3.3 vs. 3.9 cm, p = 0.507). The RSS group healed significantly faster (lower BHI) than the control group (BHI 29 vs. 43 days/cm, p = 0.028). Secondary analysis showed no difference between RSS and trauma patients in terms of the BHI (29 vs. 31); however, the BHI of the RSS group was significantly lower than both of the other congenital etiologies (29 vs. 41, p = 0.032) and tumor patients (29 vs. 66, p = 0.019). The RSS patients had fewer and less significant complications than the controls. The limb lengthening regenerate healing of RSS patients is faster than the healing of patients with other congenital etiologies and tumor patients, and is as fast as the regenerate healing of patients with posttraumatic LLD. Although all RSS patients were treated with human growth hormone (hGH), we are unable to isolate the hGH contribution to the regenerate bone healing. We conclude that RSS patients can have safe limb lengthening.

  9. Slow Wave Sleep and Long Duration Spaceflight

    Science.gov (United States)

    Whitmire, Alexandra; Orr, Martin; Arias, Diana; Rueger, Melanie; Johnston, Smith; Leveton, Lauren

    2012-01-01

    While ground research has clearly shown that preserving adequate quantities of sleep is essential for optimal health and performance, changes in the progression, order and /or duration of specific stages of sleep is also associated with deleterious outcomes. As seen in Figure 1, in healthy individuals, REM and Non-REM sleep alternate cyclically, with stages of Non-REM sleep structured chronologically. In the early parts of the night, for instance, Non-REM stages 3 and 4 (Slow Wave Sleep, or SWS) last longer while REM sleep spans shorter; as night progresses, the length of SWS is reduced as REM sleep lengthens. This process allows for SWS to establish precedence , with increases in SWS seen when recovering from sleep deprivation. SWS is indeed regarded as the most restorative portion of sleep. During SWS, physiological activities such as hormone secretion, muscle recovery, and immune responses are underway, while neurological processes required for long term learning and memory consolidation, also occur. The structure and duration of specific sleep stages may vary independent of total sleep duration, and changes in the structure and duration have been shown to be associated with deleterious outcomes. Individuals with narcolepsy enter sleep through REM as opposed to stage 1 of NREM. Disrupting slow wave sleep for several consecutive nights without reducing total sleep duration or sleep efficiency is associated with decreased pain threshold, increased discomfort, fatigue, and the inflammatory flare response in skin. Depression has been shown to be associated with a reduction of slow wave sleep and increased REM sleep. Given research that shows deleterious outcomes are associated with changes in sleep structure, it is essential to characterize and mitigate not only total sleep duration, but also changes in sleep stages.

  10. Determining a Solubility Product Constant by Potentiometric Titration to Increase Students' Conceptual Understanding of Potentiometry and Titrations

    Science.gov (United States)

    Grabowski, Lauren E.; Goode, Scott R.

    2017-01-01

    Potentiometric titrations are widely taught in first-year undergraduate courses to connect electrochemistry, stoichiometry, and equilibria and to reinforce acid-base titrations. Students perform a potentiometric titration that is then analyzed to determine analyte concentrations and the solubility product constant of the solid species.

  11. Optimal level of continuous positive airway pressure: auto-adjusting titration versus titration with a predictive equation.

    Science.gov (United States)

    Choi, Ji Ho; Jun, Young Joon; Oh, Jeong In; Jung, Jong Yoon; Hwang, Gyu Ho; Kwon, Soon Young; Lee, Heung Man; Kim, Tae Hoon; Lee, Sang Hag; Lee, Seung Hoon

    2013-05-01

    The aims of the present study were twofold. We sought to compare two methods of titrating the level of continuous positive airway pressure (CPAP) - auto-adjusting titration and titration using a predictive equation - with full-night manual titration used as the benchmark. We also investigated the reliability of the two methods in patients with obstructive sleep apnea syndrome (OSAS). Twenty consecutive adult patients with OSAS who had successful, full-night manual and auto-adjusting CPAP titration participated in this study. The titration pressure level was calculated with a previously developed predictive equation based on body mass index and apnea-hypopnea index. The mean titration pressure levels obtained with the manual, auto-adjusting, and predictive equation methods were 9.0 +/- 3.6, 9.4 +/- 3.0, and 8.1 +/- 1.6 cm H2O,respectively. There was a significant difference in the concordance within the range of +/- 2 cm H2O (p = 0.019) between both the auto-adjusting titration and the titration using the predictive equation compared to the full-night manual titration. However, there was no significant difference in the concordance within the range of +/- 1 cm H2O (p > 0.999). When compared to full-night manual titration as the standard method, auto-adjusting titration appears to be more reliable than using a predictive equation for determining the optimal CPAP level in patients with OSAS.

  12. Kinetic Titration Series with Biolayer Interferometry

    Science.gov (United States)

    Frenzel, Daniel; Willbold, Dieter

    2014-01-01

    Biolayer interferometry is a method to analyze protein interactions in real-time. In this study, we illustrate the usefulness to quantitatively analyze high affinity protein ligand interactions employing a kinetic titration series for characterizing the interactions between two pairs of interaction patterns, in particular immunoglobulin G and protein G B1 as well as scFv IC16 and amyloid beta (1–42). Kinetic titration series are commonly used in surface plasmon resonance and involve sequential injections of analyte over a desired concentration range on a single ligand coated sensor chip without waiting for complete dissociation between the injections. We show that applying this method to biolayer interferometry is straightforward and i) circumvents problems in data evaluation caused by unavoidable sensor differences, ii) saves resources and iii) increases throughput if screening a multitude of different analyte/ligand combinations. PMID:25229647

  13. Coulometrische titration von hypochloriten und chloraten.

    Science.gov (United States)

    Gründler, P; Holzapfel, H

    1970-03-01

    Hypochlorite was determined by direct coulometric titration with iron(II) in an acetate buffered solution. Chlorate was titrated with titanium(III) in 2M hydrochloric acid. Amperometric indication with one and two electrodes, respectively, was used. Mixtures of hypochlorites and chlorates, e.g., in industrial electrolytes, may be analysed. On a déterminé l'hypochlorite par titrage coulométrique direct avec le fer(II) dans une solution tamponnée à l'acétate. On a titré le chlorate avec le titane(III) en acide chlorhydrique 2M. On a utilisé l'indication ampérométrique une et deux électrodes respectivement. On peut analyser des mélanges d'hypochlorites et de chlorates, par exemple dans des électrolytes industriels.

  14. Spectrophotometric titration of zirconium in siliceous materials

    International Nuclear Information System (INIS)

    Sugawara, K.F.; Su, Y.-S.; Strzegowski, W.R.

    1978-01-01

    An accurate and selective complexometric titration procedure based upon a spectrophotometrically detected end-point has been developed for the determination of zirconium in glasses, glass-ceramics and refractories. A p-bromomandelic acid separation step for zirconium imparts excellent selectivity to the procedure. The method is particularly important for the 1 to 5% concentration range where a simple, accurate and selective method for the determination of zirconium has been lacking. (author)

  15. Determination of milligram amounts of neptunium by potentiometric titration

    International Nuclear Information System (INIS)

    Ryzhinskij, M.V.; Solntseva, L.F.

    1981-01-01

    Two procedures of potentiometric titration of about 1 mg Np are reported which are based on its oxidation to neptunium (6) with silver (2) oxide followed by titration with iron (2) to neptunium (5) in one case and to neptunium (4) in the alternative one. The error is not greater than 0.2% rel. Ten-fold uranium excess does not interfere. Up to 1% of plutonium relative to neptunium does not interfere in the case of the titration to neptunium (5). In the titration to neptunium (4), plutonium is titrated stoichiometrically [ru

  16. Histone titration against the genome sets the DNA-to-cytoplasm threshold for the Xenopus midblastula transition

    Science.gov (United States)

    Amodeo, Amanda A.; Jukam, David; Straight, Aaron F.; Skotheim, Jan M.

    2015-01-01

    During early development, animal embryos depend on maternally deposited RNA until zygotic genes become transcriptionally active. Before this maternal-to-zygotic transition, many species execute rapid and synchronous cell divisions without growth phases or cell cycle checkpoints. The coordinated onset of transcription, cell cycle lengthening, and cell cycle checkpoints comprise the midblastula transition (MBT). A long-standing model in the frog, Xenopus laevis, posits that MBT timing is controlled by a maternally loaded inhibitory factor that is titrated against the exponentially increasing amount of DNA. To identify MBT regulators, we developed an assay using Xenopus egg extract that recapitulates the activation of transcription only above the DNA-to-cytoplasm ratio found in embryos at the MBT. We used this system to biochemically purify factors responsible for inhibiting transcription below the threshold DNA-to-cytoplasm ratio. This unbiased approach identified histones H3 and H4 as concentration-dependent inhibitory factors. Addition or depletion of H3/H4 from the extract quantitatively shifted the amount of DNA required for transcriptional activation in vitro. Moreover, reduction of H3 protein in embryos induced premature transcriptional activation and cell cycle lengthening, and the addition of H3/H4 shortened post-MBT cell cycles. Our observations support a model for MBT regulation by DNA-based titration and suggest that depletion of free histones regulates the MBT. More broadly, our work shows how a constant concentration DNA binding molecule can effectively measure the amount of cytoplasm per genome to coordinate division, growth, and development. PMID:25713373

  17. A new sensor for thermometric titrations.

    Science.gov (United States)

    Najib, Fadhil M; Zewar, Sardir; Abdulla, Ahmad M

    2007-01-15

    A new thermometric sensor, which is a transistor (OC71), has been introduced to follow thermometric titrations successfully to clear end points. The sensor was suitable in both normal and differential modes of titration. It is possible to titrate down to 1.32micromol of HCl and 26.4micromol of H(3)BO(3)in a final 20ml solution with accuracy and precision of 1%, 2.2% and 1.4%, 2.2%, respectively. The sensor, in association with a pH glass electrode, was used for the determination of pK values of some well established weak acids such as, acetic acid (4.77), phosphoric acid (pK(1)=2.18, pK(2)=7.20 and pK(3)=12.32) as well as for a very weak acid of uncertain pK values H(3)BO(3) (pK(1)=9.20, pK(2)=12.7 and pK(3)=13.80). The sensor was also examined for kinetic catalytic determination of iron(III) in water, milk and pharmaceuticals.

  18. A monosegmented-flow Karl Fischer titrator.

    Science.gov (United States)

    de Aquino, Emerson Vidal; Rohwedder, Jarbas José Rodrigues; Pasquini, Celio

    2007-02-28

    A monosegmented volumetric Karl Fischer titrator is described to mechanize the determination of water content in organic solvents. The system is based on the flow-batch characteristics of the monosegmented analysis concept and employs biamperometry to monitor the progress of the titration. The system shows accuracy and precision that are highly independent of the flow rate, does not require calibration, and is carried out in a closed system capable of minimizing contact of the sample and reagents with ambient moisture. Sample volumes in the range of 40-300muL are employed, depending on the water concentration. An automatic dilution is provided to deal with concentrated samples. The consumption of Karl Fischer reagent depends on the water content of the sample but is not larger than 100muL. The system was evaluated for determination of water in ethanol and methanol in the range 0.02-0.5% (w/w). The average relative precision estimated in that range (9-3%) is comparable to that obtained with a larger volume commercial system and no significant difference was observed between the results obtained for the two systems at the 95% confidence level. A complete titration can be performed in less than 5min employing the proposed system.

  19. Potentiometric titrations in anhydrous acetic acid

    International Nuclear Information System (INIS)

    Le Port, L.

    1966-03-01

    The method used for studying anhydrous acetic acid is potentiometry with a glass electrode. We have in this way studied the titration of common inorganic acids (HClO 4 - HBr - H 2 SO 4 - HCl - HNO 3 - H 3 PO 4 ) and of some metallic salts. Furthermore we have shown that complex acids are formed between HCl and some metallic chlorides. An analysis of the titration curves for the inorganic acids against pyridinium chloride has made it possible to calculate a certain number of values for the dissociation pK of these acids and of the corresponding pyridinium salts. The titration of metallic perchlorates constitutes a method of studying the stability of acetates; we have thus been able to draw up a classification for some of these acetates. The metallic chlorides studied fall into two groups according to their behaviour in weak or strong acids. The differences have been explained on the basis of the role played by solvolysis. In the third part we have studied the acidic properties of mixtures of HCl with certain metallic chlorides. This work has demonstrated the existence, in certain cases, of acid complexes of the type (HCl) m MCl n . (author) [fr

  20. Is automatic CPAP titration as effective as manual CPAP titration in OSAHS patients? A meta-analysis.

    Science.gov (United States)

    Gao, Weijie; Jin, Yinghui; Wang, Yan; Sun, Mei; Chen, Baoyuan; Zhou, Ning; Deng, Yuan

    2012-06-01

    It is costly and time-consuming to conduct the standard manual titration to identify an effective pressure before continuous positive airway pressure (CPAP) treatment for obstructive sleep apnea (OSA) patients. Automatic titration is cheaper and more easily available than manual titration. The purpose of this systematic review was to evaluate the effect of automatic titration in identifying a pressure and on the improvement of apnea/hyponea index (AHI) and somnolence, the change of sleep quality, and the acceptance and compliance of CPAP treatment, compared with the manual titration. A systematic search was made of the PubMed, EMBASE, Cochrane Library, SCI, China Academic Journals Full-text Databases, Chinese Biomedical Literature Database, Chinese Scientific Journals Databases and Chinese Medical Association Journals. Randomized controlled trials comparing automatic titration and manual titration were reviewed. Studies were pooled to yield odds ratios (OR) or mean differences (MD) with 95% confidence intervals (CI). Ten trials involving 849 patients met the inclusion criteria. It is hard to identify a trend in the pressures determined by either automatic or manual titration. Automatic titration can improve the AHI (MD = 0.03/h, 95% CI = -4.48 to 4.53) and Epworth sleepiness scale (SMD = -0.02, 95% CI = -0.34 to 0.31,) as effectively as the manual titration. There is no difference between sleep architecture under automatic titration or manual titration. The acceptance of CPAP treatment (OR = 0.96, 95% CI = 0.60 to 1.55) and the compliance with treatment (MD = -0.04, 95% CI = -0.17 to 0.10) after automatic titration is not different from manual titration. Automatic titration is as effective as standard manual titration in improving AHI, somnolence while maintaining sleep quality similar to the standard method. In addition, automatic titration has the same effect on the acceptance and compliance of CPAP treatment as manual titration. With the potential advantage

  1. Recovery time of motor evoked potentials following lengthening and shortening muscle action in the tibialis anterior

    NARCIS (Netherlands)

    Tallent, J.; Goodall, S.; Hortobagyi, T.; Gibson, A. St Clair; French, D. N.; Howatson, G.

    Motor evoked potentials (MEP) at rest remain facilitated following an isometric muscle contraction. Because the pre-synaptic and post-synaptic control of shortening (SHO) and lengthening (LEN) contractions differs, the possibility exists that the recovery of the MEP is also task specific. The time

  2. Reduction in primary genu recurvatum gait after aponeurotic calf muscle lengthening during multilevel surgery.

    Science.gov (United States)

    Klotz, M C M; Wolf, S I; Heitzmann, D; Krautwurst, B; Braatz, F; Dreher, T

    2013-11-01

    Knee hyperextension (genu recurvatum, GR) is often seen in children with bilateral spastic cerebral palsy (CP). Primary GR appears essential without previous treatment. As equinus deformity is suspected to be one of the main factors evoking primary GR, the purpose of this study was to determine whether lengthening the calf muscles to decrease equinus would decrease coexisting GR in children with bilateral spastic CP. In a retrospective study, 19 CP patients with primary GR (mean age: 9.4 years, 13 male, 6 female, 26 involved limbs) in whom an aponeurotic calf muscle lengthening procedure was performed during single-event multilevel surgery were included and investigated using three-dimensional gait analysis before and at a mean follow-up of 14 months after the procedure according to a standardized protocol. After calf muscle lengthening, a significant improvement in ankle dorsiflexion (9.5°) and a significant reduction (10.5°) in knee hyperextension (pcalf muscle lengthening can effectively reduce GR in patients with CP. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Three-dimensional virtual model and animation of penile lengthening surgery.

    Science.gov (United States)

    Wang, Ruiheng; Yang, Dongyun; Li, Shirong

    2012-10-01

    Three-dimensional digital models, animations, and simulations have been used in the plastic surgical field for surgical education and training and patient education. In penile lengthening surgery, proper patient selection and well-designed surgical interventions are necessary; however, no such surgical or patient education tool exists. Using magnetic resonance images as references, a preliminary three-dimensional digital model of the penis with its adjacent structures was constructed using Amira 5. This preliminary model was imported into Maya 2009, a computer modeling and animation software program, for processing to correct many defects. The refined model was used to create digital animation of penile lengthening surgery, including ordered steps of the procedure, using Maya 2009 and Adobe After Effects CS4. A three-dimensional digital animation was created to illustrate penile lengthening surgery. All major surgical steps were demonstrated, including exposure, transversal incision of the fundiform ligament, partial division and release of the suspensory ligament. Three-dimensional digital models and animations of penile lengthening surgery may serve as resources for patient education to facilitate patient selection and resident education outside the operating room. Copyright © 2012 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  4. Outcome of medial hamstring lengthening in children with spastic paresis: A biomechanical and morphological observational study

    NARCIS (Netherlands)

    Haberfehlner, Helga; Jaspers, Richard T.; Rutz, Erich; Harlaar, J.; Harlaar, Jaap; Van Der Sluijs, Johannes A.; Witbreuk, Melinda; van Hutten, Kim; Romkes, Jacqueline; Freslier, Marie; Brunner, Reinald; Becher, Jules G.; Maas, H.; Buizer, Annemieke I.

    2018-01-01

    To improve gait in children with spastic paresis due to cerebral palsy or hereditary spastic paresis, the semitendinosus muscle is frequently lengthened amongst other medial hamstring muscles by orthopaedic surgery. Side effects on gait due to weakening of the hamstring muscles and overcorrections

  5. Outcome of medial hamstring lengthening in children with spastic paresis : A biomechanical and morphological observational study

    NARCIS (Netherlands)

    Haberfehlner, Helga; Jaspers, Richard T.; Rutz, Erich; Harlaar, Jaap; Van Der Sluijs, Johannes A.; Witbreuk, Melinda M.; van Hutten, Kim; Romkes, Jacqueline; Freslier, Marie; Brunner, Reinald; Becher, Jules G.; Maas, Huub; Buizer, Annemieke I.

    2018-01-01

    To improve gait in children with spastic paresis due to cerebral palsy or hereditary spastic paresis, the semitendinosus muscle is frequently lengthened amongst other medial hamstring muscles by orthopaedic surgery. Side effects on gait due to weakening of the hamstring muscles and overcorrections

  6. Foot lengthening and shortening during gait: a parameter to investigate foot function?

    NARCIS (Netherlands)

    Stolwijk, N.M.; Koenraadt, K.L.M.; Louwerens, J.W.; Grim, D.; Duysens, J.E.J.; Keijsers, N.L.W.

    2014-01-01

    INTRODUCTION: Based on the windlass mechanism theory of Hicks, the medial longitudinal arch (MLA) flattens during weight bearing. Simultaneously, foot lengthening is expected. However, changes in foot length during gait and the influence of walking speed has not been investigated yet. METHODS: The

  7. Intraoral distraction osteogenesis to lengthen the ascending ramus - Experience with seven patients

    NARCIS (Netherlands)

    Jansma, J; Bierman, MWJ; Becking, AG

    2004-01-01

    Seven children with facial asymmetry, mean age 12 years (range 11-14.5) were treated by intraoral distraction osteogenesis to lengthen the hypoplastic ramus. We achieved a mean increase in length of the ramus of 13 mm (range 10-16). In only one patient did we achieve a posterior open bite on the

  8. Intraoral distraction osteogenesis to lengthen the ascending ramus. Experience with seven patients

    NARCIS (Netherlands)

    Jansma, Johan; Bierman, Michiel W. J.; Becking, Alfred G.

    2004-01-01

    Seven children with facial asymmetry, mean age 12 years (range 11-14.5) were treated by intraoral distraction osteogenesis to lengthen the hypoplastic ramus. We achieved a mean increase in length of the ramus of 13mm (range 10-16). In only one patient did we achieve a posterior open bite on the

  9. Leg Lengthening as a Means of Improving Ambulation Following an Internal Hemipelvectomy

    Directory of Open Access Journals (Sweden)

    Wakyo Sato

    2016-01-01

    Full Text Available Reconstructive surgery following an internal hemipelvectomy for a malignant pelvic tumor is difficult due to the structural complexity of the pelvis and the massive extension of the tumor. While high complication rates have been encountered in various types of reconstructive surgery, resection without reconstruction reportedly involved fewer complications. However, this method often results in limb shortening with resultant instability during walking. We reported herein leg lengthening performed to correct lower limb shortening after an internal hemipelvectomy, which improved ambulatory stability and overall QOL. An 18-year-old male patient came to our hospital to correct a lower limb discrepancy resulting from a left internal hemipelvectomy. His left pelvis and proximal femur had been resected, and the femur remained without an acetabular roof. His left lower limb was about 8 centimeters shorter. The left tibia was lengthened 8 centimeters with an external fixator. After the lengthening, the patient was able to walk without support and his gait remarkably improved. Additionally he no longer required placing a wallet in his back pocket as a pad as a means of raising the left side of his torso while sitting. Leg lengthening was a useful method of improving ambulation after an internal hemipelvectomy.

  10. Extent of palatal lengthening after cleft palate repair as a contributing factor to the speech outcome.

    Science.gov (United States)

    Bae, Yong-Chan; Choi, Soo-Jong; Lee, Jae-Woo; Seo, Hyoung-Joon

    2015-03-01

    Operative techniques in performing cleft palate repair have gradually evolved to achieve better speech ability with its main focus on palatal lengthening and accurate approximation of the velar musculature. The authors doubted whether the extent of palatal lengthening would be directly proportional to the speech outcome. Patients with incomplete cleft palates who went into surgery before 18 months of age were intended for this study. Cases with associated syndromes, mental retardation, hearing loss, or presence of postoperative complications were excluded from the analysis. Palatal length was measured by the authors' devised method before and immediately after the cleft palate repair. Postoperative speech outcome was evaluated around 4 years by a definite pronunciation scoring system. Statistical analysis was carried out between the extent of palatal lengthening and the postoperative pronunciation score by Spearman correlation coefficient method. However, the authors could not find any significant correlation. Although the need for additional research on other variables affecting speech outcome is unequivocal, we carefully conclude that other intraoperative constituents such as accurate reapproximation of the velar musculature should be emphasized more in cleft palate repair rather than palatal lengthening itself.

  11. The role of prominence in determining the scope of boundary-related lengthening in Greek.

    Science.gov (United States)

    Katsika, Argyro

    2016-03-01

    This study aims at examining and accounting for the scope of the temporal effect of phrase boundaries. Previous research has indicated that there is an interaction between boundary-related lengthening and prominence such that the former extends towards the nearby prominent syllable. However, it is unclear whether this interaction is due to lexical stress and/or phrasal prominence (marked by pitch accent) and how far towards the prominent syllable the effect extends. Here, we use an electromagnetic articulography (EMA) study of Greek to examine the scope of boundary-related lengthening as a function of lexical stress and pitch accent separately. Boundaries are elicited by the means of a variety of syntactic constructions.. The results show an effect of lexical stress. Phrase-final lengthening affects the articulatory gestures of the phrase-final syllable that are immediately adjacent to the boundary in words with final stress, but is initiated earlier within phrase-final words with non-final stress. Similarly, the articulatory configurations during inter-phrasal pauses reach their point of achievement later in words with final stress than in words with non-final stress. These effects of stress hold regardless of whether the phrase-final word is accented or de-accented. Phrase-initial lengthening, on the other hand, is consistently detected on the phrase-initial constriction, independently of where the stress is within the preceding, phrase-final, word. These results indicate that the lexical aspect of prominence plays a role in determining the scope of boundary-related lengthening in Greek. Based on these results, a gestural account of prosodic boundaries in Greek is proposed in which lexical and phrasal prosody interact in a systematic and coordinated fashion. The cross-linguistic dimensions of this account and its implications for prosodic structure are discussed.

  12. Callus features of regenerate fracture cases in femoral lengthening in achondroplasia

    Energy Technology Data Exchange (ETDEWEB)

    Devmurari, Kamlesh N.; Song, Hae Ryong; Modi, Hitesh N.; Venkatesh, K.P.; Ju, Kim Seung; Song, Sang Heon [Korea University Medical College, Institute for Rare Diseases and Department of Orthopedic Surgery, Seoul (Korea)

    2010-09-15

    We studied the callus features seen in cases of regenerate fracture in femoral lengthening using a monolateral fixator in achondroplasia to determine whether callus types and shapes can predict the probability of callus fracture. The radiographs of 28 cases of femoral lengthening in 14 patients, 14 cases of callus fracture, and 14 cases without callus fracture were retrospectively analyzed by four observers and classified into different shapes and types in concordance with the Ru Li classification. The average lengthening of 9.4 cm (range 7.5-11.8 cm) was achieved, which was 41% (range 30-55%) of the original length and the average timing of callus fracture was 470 days (range 440-545 days) after surgery in the callus fracture group. While the average lengthening of 9.1 cm (range 8-9.7 cm) was achieved, this was 30% (range 28-32%) of the original length in the group of patients without callus fracture. The callus was atypically shaped, there was a 48% average (range 30-72%) reduction of the callus width compared with the natural width of the femur, and a lucent pathway was present in all cases of regenerate fracture. A lucent pathway was seen in all fracture cases with concave, lateral, and atypical shapes, and there was more than 30% lengthening and 30% reduction of the callus width compared with the natural width of the femur, which are the warning signs for regenerate fractures. These signs help the surgeon to predict the outcome and guide him in planning for any additional interventions. The Ru Li classification is an effective method for the evaluation of the chance of callus fracture. (orig.)

  13. A Comparative Evaluation for Biologic Width following Surgical Crown Lengthening Using Gingivectomy and Ostectomy Procedure

    Directory of Open Access Journals (Sweden)

    Kiran Kumar Ganji

    2012-01-01

    Full Text Available Surgical crown lengthening has been proposed as a means of facilitating restorative procedures and preventing injuries in teeth with structurally inadequate clinical crown or exposing tooth structure in the presence of deep, subgingival pathologies which may hamper the access for proper restorative measures. Histological studies utilizing animal models have shown that postoperative crestal resorption allowed reestablishment of the biologic width. However, very little has been done in humans. Aims. The purpose of the study was to evaluate the potential changes in the periodontal tissues, particularly the biologic width, following surgical crown lengthening by two surgical procedures before and after crown placement. Methods and Material. Twenty (20 patients who needed surgical crown lengthening to gain retention necessary for prosthetic treatment and/or to access caries, tooth fracture, or previous prosthetic margins entered the study. The following parameters were obtained from line angles of treated teeth (teeth requiring surgical crown lengthening and adjacent sites: Plaque and Gingival Indices (PI & (GI, Position of Gingival Margin from reference Stent (PGMRS, Probing depth (PD, and Biologic Width (BW. Statistical Analysis Used. Student “t” Test. Results. Initial baseline values of biologic width were 2.55 mm (Gingivectomy procedure B1 Group and 1.95 mm (Ostectomy procedure B2 Group and after surgical procedure the values were 1.15 mm and 1.25 mm. Conclusions. Within the limitations of the study the biologic width, at treated sites, was re-established to its original vertical dimension by 3 months. Ostectomy with apically positioned flap can be considered as a more effective procedure than Gingivectomy for Surgical Crown Lengthening.

  14. Lengthening of the congenital short femur using the Ilizarov technique: a single-surgeon series.

    Science.gov (United States)

    Aston, W J S; Calder, P R; Baker, D; Hartley, J; Hill, R A

    2009-07-01

    We present a retrospective review of a single-surgeon series of 30 consecutive lengthenings in 27 patients with congenital short femur using the Ilizarov technique performed between 1994 and 2005. The mean increase in length was 5.8 cm/18.65% (3.3 to 10.4, 9.7% to 48.8%), with a mean time in the frame of 223 days (75 to 363). By changing from a distal to a proximal osteotomy for lengthening, the mean range of knee movement was significantly increased from 98.1 degrees to 124.2 degrees (p = 0.041) and there was a trend towards a reduced requirement for quadricepsplasty, although this was not statistically significant (p = 0.07). The overall incidence of regenerate deformation or fracture requiring open reduction and internal fixation was similar in the distal and proximal osteotomy groups (56.7% and 53.8%, respectively). However, in the proximal osteotomy group, pre-placement of a Rush nail reduced this rate from 100% without a nail to 0% with a nail (p < 0.001). When comparing a distal osteotomy with a proximal one over a Rush nail for lengthening, there was a significant decrease in fracture rate from 58.8% to 0% (p = 0.043). We recommend that in this group of patients lengthening of the femur with an Ilizarov construct be carried out through a proximal osteotomy over a Rush nail. Lengthening should also be limited to a maximum of 6 cm during one treatment, or 20% of the original length of the femur, in order to reduce the risk of complications.

  15. Distraction lengthening by callotasis of traumatically shortened bones of the hand.

    Science.gov (United States)

    Hosny, Gamal Ahmad; Kandel, Wael Abdelaziz

    2012-06-01

    Callotasis of the hand has several advantages: it is less invasive than other techniques as bone grafting is unnecessary, gradual distraction is possible, joint mobilization can be performed during treatment, and sensation is maintained. Disadvantages include longer period of treatment and perhaps the need for complicated and bulky instrumentation. We reported results of the lengthening of eight traumatically shortened metacarpals or phalanges (in six patients). There were two men and four women, with a mean age of 17.5 years. There were one thumb and seven fingers. There were three proximal phalanges and five metacarpals. Unilateral external fixator was applied to all cases. Osteotomy was performed at the proximal metaphysis in three cases, middle diaphysis in two cases, and the distal metaphysis in three cases. Lengthening was begun after 10 days to 14 days at a rate of 0.25 mm two times or three times daily. We modified the rate of distraction according to the development of pain, sensory disturbance, and contracture of the digit during lengthening. In former cases, the rate was 0.25 mm three times daily. The proposed length was achieved in all digits and no bone graft was required. The mean length increase was 18.9 mm (53.5% of the original length of 35.25 mm). Age was positively correlated with the healing index and consolidation time as younger patients healed faster than older patients. Conversely, the faster the distraction rate, the slower were the healing index and consolidation time. There were few complications which did not affect the final results. We preferred metacarpal lengthening in cases with very short proximal phalangeal traumatic amputation stump (<1 cm). Distraction lengthening is a valid option with minor complications rate. Therapeutic study, level V. Copyright © 2012 by Lippincott Williams & Wilkins.

  16. A biomechanical analysis of the effect of lateral column lengthening calcaneal osteotomy on the flat foot.

    Science.gov (United States)

    Arangio, George A; Chopra, Vikram; Voloshin, Arkady; Salathe, Eric P

    2007-05-01

    Biomechanical models have been used to study the plantar aponeurosis, medial arch height, subtalar motion, medial displacement calcaneal osteotomy, subtalar arthroereisis and the distribution of forces in the normal and flat foot. The objective was to examine the hypothesis that increased load on the medial arch in the adult flat foot can be reduced through a 10mm lateral column lengthening calcaneal osteotomy 10 mm proximal from the calcaneal cuboid joint. A three dimensional multisegment biomechanical model was used with anatomical data from a normal foot, a flat foot and a foot corrected with a 10mm lateral column lengthening calcaneal osteotomy. The response of a normal foot, a flat foot and a flat foot with a 10mm lateral column lengthening calcaneal osteotomy to an applied load of 683 N was analyzed using the biomechanical model. Data for the biomechanical model was obtained from a cadaver foot using the direct linear transformation method. Direct linear transformation uses multiple cameras to determine the spatial location of anatomical landmarks. Load on the first metatarsal increases to 37% body weight in the flat foot compared to 12% for the normal foot and the moment about the talo-navicular joint increases from 5.6 N m to 21.6 N m. Lateral column lengthening shifts the load toward the lateral column, decreasing load on the first metatarsal to 10% and decreasing the moment about the talo-navicular joint to 8.1 N m. The analysis shows that a 10mm lateral column lengthening calcaneal osteotomy reduces the excess force on the medial arch in an adult flat foot and adds biomechanical rationale to this clinical procedure.

  17. [Long-term treatment outcome and influencing factors of teeth receiving modified crown lengthening].

    Science.gov (United States)

    Wang, C; Jia, X T; Hu, W J; Zhen, M; Zhang, H

    2017-03-09

    Objective: To observe the long-term clinical treatment outcome and the influencing factors of the outcome for the teeth receiving modified crown lengthening surgery combined with root canal treatment and post-core crown restoration. To summarize the clinical guidelines of modified crown lengthening surgery in selection of indications and for mulation of treatment planning. Methods: Fifty-seven patients with a total of 67 teeth receiving modified crown lengthening surgery combined with root canal treatment and post-core crown restoration for at least a 6 months' follow-up period between July 2004 and July 2013 were recruited in this retrospective study by phone call interviews. The patients' clinical outcomes were evaluated by the combination of clinical examination, radiograph and questionnaire regarding patient-reported outcome of the last follow up (≥9 months post modified crown lengthening surgery and ≥6 months after definite crown restorations). All of the treated teeth were classified into two groups, group A (teeth with good clinical treatment outcome) and group B (teeth with poor clinical treatment outcome), based on the defined criteria including patients' satisfaction with the function and esthetics of the teeth and absence of periodontal, endodontic and prosthodontic complications. The potential influencing factors of clinical treatment outcome were also determined by Logistic regression analysis. Results: Vertical root fracture in 1 tooth was found on its periapical film and the tooth was deemed hopeless. Thus, the survival rate is 99% (66/67) for the multidisciplinary treatment approach. Seventy-two percent (48/67) of the teeth achieved good clinical treatment outcome and 28% (19/67) of the teeth developed one or several complications. In group B (teeth with poor clinical treatment), 16 out of teeth exhibited periodontal complications with bleeding on probing (BOP) positive mostly found. Logistic regression analysis demonstrated that plaque control

  18. Improving medication titration in heart failure by embedding a structured medication titration plan.

    Science.gov (United States)

    Hickey, Annabel; Suna, Jessica; Marquart, Louise; Denaro, Charles; Javorsky, George; Munns, Andrew; Mudge, Alison; Atherton, John J

    2016-12-01

    To improve up-titration of medications to target dose in heart failure patients by improving communication from hospital to primary care. This quality improvement project was undertaken within three heart failure disease management (HFDM) services in Queensland, Australia. A structured medication plan was collaboratively designed and implemented in an iterative manner, using methods including awareness raising and education, audit and feedback, integration into existing work practice, and incentive payments. Evaluation was undertaken using sequential audits, and included process measures (use of the titration plan, assignment of responsibility) and outcome measures (proportion of patients achieving target dose) in HFDM service patients with reduced left ventricular ejection fraction. Comparison of the three patient cohorts (pre-intervention cohort A n=96, intervention cohort B n=95, intervention cohort C n=89) showed increase use of the titration plan, a shift to greater primary care responsibility for titration, and an increase in the proportion of patients achieving target doses of angiotensin converting enzyme inhibitors/angiotensin receptor blockers (ACEI/ARB) (A 37% vs B 48% vs C 55%, p=0.051) and beta-blockers (A 38% vs B 33% vs C 51%, p=0.045). Combining all three cohorts, patients not on target doses when discharged from hospital were more likely to achieve target doses of ACEI/ARB (pplan. A medication titration plan was successfully implemented in three HFDM services and improved transitional communication and achievement of target doses of evidence-based therapies within six months of hospital discharge. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  19. Up-titration of allopurinol in patients with gout.

    Science.gov (United States)

    Jennings, Claudine G; Mackenzie, Isla S; Flynn, Rob; Ford, Ian; Nuki, George; De Caterina, Raffaele; Riches, Philip L; Ralston, Stuart H; MacDonald, Thomas M

    2014-08-01

    European League against Rheumatism (EULAR) gout management guidelines recommend achieving a target urate level titration in achieving the EULAR target levels. The Febuxostat versus Allopurinol Streamlined Trial (FAST) is an ongoing multi-centre study comparing the cardiovascular safety of febuxostat and allopurinol (target recruitment: 5706 patients). Recruited patients were already taking allopurinol and the protocol required up-titration of daily allopurinol dose, in 100 mg increments, to achieve the EULAR urate target level prior to randomisation. We reviewed pre-randomisation data from the first 400 recruited and subsequently randomised FAST patients. Of 400 patients, 144 (36%) had urate levels ≥357 µmol/L at screening and required allopurinol up-titration. Higher urate levels were significantly associated with lower allopurinol dose, male sex, increased BMI, increased alcohol intake and diuretic use. Mean fall in urate levels after a single 100-mg dose increase was 71 µmol/L. The number of up-titrations required ranged from one to five (median = 1) with 65% of patients controlled after one 100-mg up-titration. Overall, 97% of up-titrated patients achieved target urate levels with median final allopurinol dose of 300 mg daily. Side effects and complications of up-titration were minimal. Overall, 36% of FAST patients were not at target urate levels and required up-titration. Allopurinol up-titration was effective in achieving urate target levels and was generally well tolerated by patients. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Laboratory Automatic Titration of Chromium Plating and Electropolishing Solutions

    National Research Council Canada - National Science Library

    Sopok, Samuel

    2001-01-01

    .... The analytical chemistry literature lacks an adequate automatic titration method for the monitoring of chromic acid in chromium plating solutions and the monitoring of phosphoric and sulfuric acids...

  1. Automated titration method for use on blended asphalts

    Science.gov (United States)

    Pauli, Adam T [Cheyenne, WY; Robertson, Raymond E [Laramie, WY; Branthaver, Jan F [Chatham, IL; Schabron, John F [Laramie, WY

    2012-08-07

    A system for determining parameters and compatibility of a substance such as an asphalt or other petroleum substance uses titration to highly accurately determine one or more flocculation occurrences and is especially applicable to the determination or use of Heithaus parameters and optimal mixing of various asphalt stocks. In a preferred embodiment, automated titration in an oxygen gas exclusive system and further using spectrophotometric analysis (2-8) of solution turbidity is presented. A reversible titration technique enabling in-situ titration measurement of various solution concentrations is also presented.

  2. A computer controlled potentiometric titrator for quantitative determination of uranium

    International Nuclear Information System (INIS)

    Verdingh, V.; Michiels, A.

    1988-01-01

    The modified Davies and Gray methods is frequently used for the potentiometric titration of uranium. It is based upon the reduction of U(VI) to U(IV) with a reductant (e.g. Fe ++ ) followed by a selective oxidation of the excess of reductant and subsequent titration of U(IV) with potassium dichromate (K 2 Cr 2 O 7 ). Interference from other elements is low, but the method is rather cumbersome due to the number of reactants to be added before the titration is started. The timing of these additions also plays a role. In order to render the titration less dependent on human factors and with the aim of reaching high reproducibility, a computer controlled system has been designed and set-up. Reagents are added by five computer controlled burettes. A program allows the choice of volumes and waiting times, and commands the start of the final titration which is followed by the microprocessor of the automatic potentiometric titrator. In this way a routine uranium titration can be completed in about twelve minutes. Reproducibilities of the order of ±15% are achievable in routine operation. For high precision work, the titrator is used as an end-point detector. Titrant is added manually by mass, so as to react with > 99% of the uranium. The residual uranium is then titrated automatically by colume with diluted titrant. The precision can be improved by a factor of approximately ten. (orig.)

  3. The opening base wedge osteotomy and subsequent lengthening of the first metatarsal: an in vitro study.

    Science.gov (United States)

    Budny, Adam M; Masadeh, Suhail B; Lyons, Michael C; Frania, Stephen J

    2009-01-01

    Traditionally, the opening base wedge osteotomy has been indicated in a moderate to severe hallux abducto valgus deformity with a short first metatarsal. This in vitro study aimed to address the question of how much lengthening is inherent to the geometric design of an opening wedge in the first metatarsal. The preosteotomy length of a first metatarsal segment was compared with postosteotomy length after performing transverse and oblique basilar osteotomies while maintaining the opening wedge with a prefabricated spacer. In the current bench study, it was found that the opening base wedge osteotomy does indeed lengthen the first metatarsal, albeit a small percentage of the total length (1%-2.8%), and there was no significant difference between the lengths achieved through a transverse or oblique osteotomy based on a confidence interval of 95%. 5.

  4. A guide to minimally invasive crown lengthening and tooth preparation for rehabilitating pink and white aesthetics.

    Science.gov (United States)

    Al-Harbi, F; Ahmad, I

    2018-02-23

    The rehabilitation of anterior dental aesthetics involves a multitude of disciplines, each with its own methodologies for achieving a predefined goal. The literature is awash with different techniques for a given predicament, based on both scientific credence, as well as empirical clinical judgements. An example is crown lengthening for correcting uneven gingival zeniths, increasing clinical crown lengths, and therefore, reducing the amount of maxillary gingival display that detracts from pleasing pink aesthetics. Many procedures have been advocated for rectifying gingival anomalies depending on prevailing clinical scenarios and aetiology. This paper presents a minimally invasive technique for crown lengthening for short clinical crowns concurrent with excessive maxillary gingival display, which is expedient, maintaining the inter-proximal papilla, mitigating morbidity, reducing post-operative inflammation, and increasing patient comfort. In addition, with a similar ethos, a minimally invasive tooth preparation approach is presented for achieving optimal white aesthetics.

  5. Effect of V-Y plasty on lip lengthening and treatment of gummy smile.

    Science.gov (United States)

    Dilaver, E; Uckan, S

    2018-02-01

    The aim of this study was to assess the effect of isolated V-Y plasty on lip lengthening and the treatment of gummy smile. An isolated V-Y plasty was performed on 14 patients with a gummy smile. In each case, measurements of upper lip length and gingival display were recorded from posed-smile photographs taken preoperatively and at 1, 3, and 6 months postoperatively. Gingival display decreased significantly and lip length increased significantly over all intervals investigated. Applying this technique after Le Fort I surgery may be beneficial; however, as with other injection or surgical lip lengthening methods, its stand-alone application should be questioned. Copyright © 2017 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  6. Outcome of medial hamstring lengthening in children with spastic paresis: A biomechanical and morphological observational study.

    Directory of Open Access Journals (Sweden)

    Helga Haberfehlner

    Full Text Available To improve gait in children with spastic paresis due to cerebral palsy or hereditary spastic paresis, the semitendinosus muscle is frequently lengthened amongst other medial hamstring muscles by orthopaedic surgery. Side effects on gait due to weakening of the hamstring muscles and overcorrections have been reported. How these side effects relate to semitendinosus morphology is unknown. This study assessed the effects of bilateral medial hamstring lengthening as part of single-event multilevel surgery (SEMLS on (1 knee joint mechanics (2 semitendinosus muscle morphology and (3 gait kinematics. All variables were assessed for the right side only. Six children with spastic paresis selected for surgery to counteract limited knee range of motion were measured before and about a year after surgery. After surgery, in most subjects popliteal angle decreased and knee moment-angle curves were shifted towards a more extended knee joint, semitendinosus muscle belly length was approximately 30% decreased, while at all assessed knee angles tendon length was increased by about 80%. In the majority of children muscle volume of the semitendinosus muscle decreased substantially suggesting a reduction of physiological cross-sectional area. Gait kinematics showed more knee extension during stance (mean change ± standard deviation: 34±13°, but also increased pelvic anterior tilt (mean change ± standard deviation: 23±5°. In most subjects, surgical lengthening of semitendinosus tendon contributed to more extended knee joint angle during static measurements as well as during gait, whereas extensibility of semitendinosus muscle belly was decreased. Post-surgical treatment to maintain muscle belly length and physiological cross-sectional area may improve treatment outcome of medial hamstring lengthening.

  7. Role of alternative telomere lengthening unmasked in telomerase knock-out mutant plants

    Czech Academy of Sciences Publication Activity Database

    Růčková, Eva; Friml, J.; Procházková Schrumpfová, Petra; Fajkus, Jiří

    2008-01-01

    Roč. 66, č. 6 (2008), s. 637-646 ISSN 0167-4412 R&D Projects: GA MŠk(CZ) LC06004; GA ČR(CZ) GA521/05/0055; GA AV ČR(CZ) IAA600040505 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : alternative telomere lengthening * plant * replicative telomere shortening Subject RIV: BO - Biophysics Impact factor: 3.541, year: 2008

  8. Outcome of medial hamstring lengthening in children with spastic paresis: A biomechanical and morphological observational study

    Science.gov (United States)

    Jaspers, Richard T.; Rutz, Erich; Harlaar, Jaap; van der Sluijs, Johannes A.; Witbreuk, Melinda M.; van Hutten, Kim; Romkes, Jacqueline; Freslier, Marie; Brunner, Reinald; Becher, Jules G.

    2018-01-01

    To improve gait in children with spastic paresis due to cerebral palsy or hereditary spastic paresis, the semitendinosus muscle is frequently lengthened amongst other medial hamstring muscles by orthopaedic surgery. Side effects on gait due to weakening of the hamstring muscles and overcorrections have been reported. How these side effects relate to semitendinosus morphology is unknown. This study assessed the effects of bilateral medial hamstring lengthening as part of single-event multilevel surgery (SEMLS) on (1) knee joint mechanics (2) semitendinosus muscle morphology and (3) gait kinematics. All variables were assessed for the right side only. Six children with spastic paresis selected for surgery to counteract limited knee range of motion were measured before and about a year after surgery. After surgery, in most subjects popliteal angle decreased and knee moment-angle curves were shifted towards a more extended knee joint, semitendinosus muscle belly length was approximately 30% decreased, while at all assessed knee angles tendon length was increased by about 80%. In the majority of children muscle volume of the semitendinosus muscle decreased substantially suggesting a reduction of physiological cross-sectional area. Gait kinematics showed more knee extension during stance (mean change ± standard deviation: 34±13°), but also increased pelvic anterior tilt (mean change ± standard deviation: 23±5°). In most subjects, surgical lengthening of semitendinosus tendon contributed to more extended knee joint angle during static measurements as well as during gait, whereas extensibility of semitendinosus muscle belly was decreased. Post-surgical treatment to maintain muscle belly length and physiological cross-sectional area may improve treatment outcome of medial hamstring lengthening. PMID:29408925

  9. Apple-peel intestinal atresia: enteroplasty for intestinal lengthening and primary anastomosis.

    Science.gov (United States)

    Onofre, Luciano Silveira; Maranhão, Renato Frota de Albuquerque; Martins, Elaine Cristina Soares; Fachin, Camila Girardi; Martins, Jose Luiz

    2013-06-01

    Apple-peel atresia (or Type-IIIb intestinal atresia) is an unusual type of jejunoileal atresia. They present with jejunal atresia near the ligament of Treitz and a foreshortened small bowel. Many surgical options have been used, but the optimal method of repair remains unclear. We present a case of a newborn with apple-peel intestinal atresia managed by enteroplasty for intestinal lengthening and primary anastomosis. Copyright © 2013 Elsevier Inc. All rights reserved.

  10. SPS slow extraction septa

    CERN Multimedia

    CERN PhotoLab

    1979-01-01

    SPS long straight section (LSS) with a series of 5 septum tanks for slow extraction (view in the direction of the proton beam). There are 2 of these: in LSS2, towards the N-Area; in LSS6 towards the W-Area. See also Annual Report 1975, p.175.

  11. Peak power is reduced following lengthening contractions despite a maintenance of shortening velocity.

    Science.gov (United States)

    Power, Geoffrey A; Dalton, Brian H; Rice, Charles L; Vandervoort, Anthony A

    2013-12-01

    Following repetitive lengthening contractions, power (the product of torque and velocity) is impaired during shortening contractions. However, the relative contribution of each component to power loss and the underlying factors are unclear. We investigated neuromuscular properties of the dorsiflexors in 8 males (27 ± 3 years) and 8 females (26 ± 4 years) for a potential sex-related difference before, during, and after 150 unaccustomed maximal lengthening actions. Velocity-dependent power was determined from shortening contractions at 8 levels (1 N · m to 70% of maximum voluntary isometric contraction (MVC)) before, after, and throughout recovery assessed at 0-30 min, 24 h, and 48 h. Immediately following task termination, both sexes displayed similar impairments of 30%, 4%, and 10% in MVC torque, shortening velocity, and overall peak power, respectively (P reduced by 10% in males, but females exhibited a 35% reduction (P reduced preferentially at higher loads (i.e., 60% MVC), with a greater loss in females (65%) than males (45%). For lower loads (velocity persisted until 30 min of recovery, and peak power did not recover until 24 h for both sexes. Unaccustomed lengthening contractions decreased power preferentially at higher loads, whereas peak power was reduced minimally owing to maintenance of maximal shortening velocity.

  12. Active finite element analysis of skeletal muscle-tendon complex during isometric, shortening and lengthening contraction.

    Science.gov (United States)

    Tsui, C P; Tang, C Y; Leung, C P; Cheng, K W; Ng, Y F; Chow, D H K; Li, C K

    2004-01-01

    An active finite element model was developed to predict the mechanical behaviors of skeletal muscle-tendon complex during isometric, shortening and lengthening contraction. The active finite element was created through incorporation of a user-defined material property into ABAQUS finite element code. The active finite element is controlled by a motor element that is activated by a mathematical function. The nonlinear passive behavior of the muscle was defined by the viscoelastic elements and can be easily altered to other properties by using other elements in the material library without the need of re-defining the constitutive relation of the muscle. The isometric force-length relationship, force-strain relations of the muscle-tendon complex during both shortening and lengthening contraction and muscle relaxation response were predicted using the proposed finite element model. The predicted results were found to be in good agreement with available experimental data. In addition, the stress distribution in the muscle-tendon complex during isometric, shortening and lengthening contractions was simulated. The location of the maximum stress may provide useful information for studying muscle damage and fatigue in the future.

  13. Utilization and efficacy of computational gait analysis for hamstring lengthening surgery.

    Science.gov (United States)

    MacWilliams, Bruce A; Stotts, Alan K; Carroll, Kristen L; D'Astous, Jacques L

    2016-09-01

    A retrospective analysis of computational gait studies performed in a single lab over a 12 year period was undertaken to characterize how recommendations to perform or not to perform hamstring lengthenings were utilized by physicians and the effect on outcomes. 131 Subjects were identified as either having hamstring lengthening considered by the referring surgeon, recommended by gait analysis data, or performed. A subset of this data meeting inclusion criteria for pre- and post-surgical timeframes, and bilateral diagnosis was further analyzed to assess the efficacy of the recommendations. There was initial agreement between planned procedures and recommended procedures in just 41% of the cases. Including the cases where there was agreement, gait analysis altered the initial procedure in 54%. In the cases where the initial plan was not supported by gait data, surgeons followed gait recommendations in 77%. In subjects who underwent hamstring lengthening, when surgeons followed or agreed with gait recommendations, patients were 3.6 times more likely to experience a positive outcome. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. The acid-base titration of montmorillonite

    Science.gov (United States)

    Bourg, I. C.; Sposito, G.; Bourg, A. C.

    2003-12-01

    Proton binding to clay minerals plays an important role in the chemical reactivity of soils (e.g., acidification, retention of nutrients or pollutants). If should also affect the performance of clay barriers for waste disposal. The surface acidity of clay minerals is commonly modelled empirically by assuming generic amphoteric surface sites (>SOH) on a flat surface, with fitted site densities and acidity constant. Current advances in experimental methods (notably spectroscopy) are rapidly improving our understanding of the structure and reactivity of the surface of clay minerals (arrangement of the particles, nature of the reactive surface sites, adsorption mechanisms). These developments are motivated by the difficulty of modelling the surface chemistry of mineral surfaces at the macro-scale (e.g., adsorption or titration) without a detailed (molecular-scale) picture of the mechanisms, and should be progressively incorporated into surface complexation models. In this view, we have combined recent estimates of montmorillonite surface properties (surface site density and structure, edge surface area, surface electrostatic potential) with surface site acidities obtained from the titration of alpha-Al2O3 and SiO2, and a novel method of accounting for the unknown initial net proton surface charge of the solid. The model predictions were compared to experimental titrations of SWy-1 montmorillonite and purified MX-80 bentonite in 0.1-0.5 mol/L NaClO4 and 0.005-0.5 mol/L NaNO3 background electrolytes, respectively. Most of the experimental data were appropriately described by the model after we adjusted a single parameter (silanol sites on the surface of montmorillonite were made to be slightly more acidic than those of silica). At low ionic strength and acidic pH the model underestimated the buffering capacity of the montmorillonite, perhaps due to clay swelling or to the interlayer adsorption of dissolved aluminum. The agreement between our model and the experimental

  15. CT Measurement of Range of Motion of Ankle and Subtalar Joints Following Two Lateral Column Lengthening Procedures

    NARCIS (Netherlands)

    Beimers, Lijkele; Louwerens, Jan W. K.; Tuijthof, Gabrielle Josephine Maria; Jonges, Remmet; van Dijk, C. N. Niek; Blankevoort, Leendert

    2012-01-01

    Background: Lateral column lengthening (LCL) has become an accepted procedure for the operative treatment of the flexible flatfoot deformity. Hindfoot arthrodesis via a calcaneocuboid distraction arthrodesis (CCDA) has been considered a less favourable surgical option than the anterior open wedge

  16. Limits of Calcaneal Lengthening for Treating Planovalgus Foot Deformity in Children With Cerebral Palsy.

    Science.gov (United States)

    Luo, Chi-An; Kao, Hsuan-Kai; Lee, Wei-Chun; Yang, Wen-E; Chang, Chia-Hsieh

    2017-08-01

    Calcaneal lengthening is used to correct symptomatic planovalgus foot deformity, but outcomes have been less satisfactory in children with cerebral palsy. This study aimed to define limits of calcaneal lengthening by analyzing the risk factors for undercorrection of deformity. We retrospectively reviewed 20 cases of children with cerebral palsy who underwent calcaneal lengthening of 30 planovalgus feet at a mean age of 11.9 years. Foot deformities were evaluated by the anteroposterior talo-first metatarsal angle (normal, 10 ± 7.0 degrees), lateral talo-first metatarsal angle (normal, 13 ± 7.5 degrees), and lateral calcaneal pitch angle (normal, 17 ± 6.0 degrees) on standing foot radiographs. Among these parameters, a corrected foot was defined as 2 or 3 parameters being corrected to within a normal range, and an undercorrected foot was only 1 or no parameter being corrected to within a normal range. Factors were compared between the corrected group and undercorrected group for significant predictors, and cutoff values of predictors were calculated for use as a clinical guideline. Seventeen planovalgus feet were corrected satisfactorily by calcaneal lengthening, while the other 13 feet were undercorrected. Undercorrected feet had a greater preoperative anteroposterior talonavicular angle (33.7 vs 22.8 degrees, P = .001) and a smaller lateral calcaneal pitch (-1.7 vs 5.6 degrees, P = .03). A talonavicular angle of more than 24 degrees and calcaneal pitch less than -5 degrees were identified as cutoff values using a receiver operating characteristic curve. The predicted probability of undercorrection was 100% (9/9 feet) for 2 positive predictors, 50% (8/16 feet) for 1 positive predictor, and 0 (0/5 feet) for zero predictors. A talonavicular lateral subluxation of more than 24 degrees on the anteroposterior radiograph and a calcaneal pitch angle less than -5 degrees on the lateral radiograph were 2 independent predictors that could be used to identify a planovalgus

  17. A Closer Look at Acid-Base Olfactory Titrations

    Science.gov (United States)

    Neppel, Kerry; Oliver-Hoyo, Maria T.; Queen, Connie; Reed, Nicole

    2005-01-01

    Olfactory titrations using raw onions and eugenol as acid-base indicators are reported. An in-depth investigation on olfactory titrations is presented to include requirements for potential olfactory indicators and protocols for using garlic, onions, and vanillin as acid-base olfactory indicators are tested.

  18. Differential Binding Models for Direct and Reverse Isothermal Titration Calorimetry.

    Science.gov (United States)

    Herrera, Isaac; Winnik, Mitchell A

    2016-03-10

    Isothermal titration calorimetry (ITC) is a technique to measure the stoichiometry and thermodynamics from binding experiments. Identifying an appropriate mathematical model to evaluate titration curves of receptors with multiple sites is challenging, particularly when the stoichiometry or binding mechanism is not available. In a recent theoretical study, we presented a differential binding model (DBM) to study calorimetry titrations independently of the interaction among the binding sites (Herrera, I.; Winnik, M. A. J. Phys. Chem. B 2013, 117, 8659-8672). Here, we build upon our DBM and show its practical application to evaluate calorimetry titrations of receptors with multiple sites independently of the titration direction. Specifically, we present a set of ordinary differential equations (ODEs) with the general form d[S]/dV that can be integrated numerically to calculate the equilibrium concentrations of free and bound species S at every injection step and, subsequently, to evaluate the volume-normalized heat signal (δQ(V) = δq/dV) of direct and reverse calorimetry titrations. Additionally, we identify factors that influence the shape of the titration curve and can be used to optimize the initial concentrations of titrant and analyte. We demonstrate the flexibility of our updated DBM by applying these differentials and a global regression analysis to direct and reverse calorimetric titrations of gadolinium ions with multidentate ligands of increasing denticity, namely, diglycolic acid (DGA), citric acid (CIT), and nitrilotriacetic acid (NTA), and use statistical tests to validate the stoichiometries for the metal-ligand pairs studied.

  19. Titrated oral misoprostol solution- a new method of labour induction ...

    African Journals Online (AJOL)

    Titrated oral misoprostol solution- a new method of labour induction. ... To develop a new method of misoprostol use for labour induction using very small, frequent, titrated oral dosages, and to pilot effectiveness. Study design. Open clinical pilot ... A multicentre randomised trial of this method is underway. We emphasise the ...

  20. Automated proton titrations of pancreatic phospholipase A2

    NARCIS (Netherlands)

    Donné-Op den Kelder, G.M.; Haas, G.H. de; Egmond, M.R.

    1982-01-01

    A computer-controlled titration system has been developed, tested, and used for analysis of the proton-titration behavior of pancreatic phospholipase A2 from ox, horse, and pig. The results revealed an error in the reported amino acid composition of the equine enzyme. A simple interface for the

  1. a randomised trial comparing Foley catheter plus titrated oral ...

    African Journals Online (AJOL)

    Labour induction at term - a randomised trial comparing. Foley catheter plus titrated oral misoprostol solution, titrated oral misoprostol solution alone, and dinoprostone. Baron B Matonhodze, G Justus Hofmeyr, Jonathan Levin. Objectives. To compare three methods of labour induction. Design. Randomised controlled trial.

  2. New applications of corrosion measurements by titration (CMT)

    DEFF Research Database (Denmark)

    Bech-Nielsen, Gregers

    1998-01-01

    . It is shown that when aluminium dissolves in alkali, CMT measurements can also be applied, but in this case requiring titration with alkali. Titration with alkali is also required in a special situation, where corrosion of nickel in an acid solution and subsequent formation of a nickel complex results...

  3. The coulometric titration of acids and bases in dimethylsulfoxide media

    NARCIS (Netherlands)

    Bos, M.; IJpma, S.T.; Dahmen, E.A.M.F.

    1976-01-01

    The coulometric titration of 20–200 μeq of acids and bases in DMSO media is described. In the titration of bases, the electro-oxidation of hydrogen at a platinized platinum electrode is used as the source of protons. The conditions for 100 % current efficiency at this electrode are low current

  4. Is bilateral lower limb lengthening appropriate for achondroplasia?: midterm analysis of the complications and quality of life.

    Science.gov (United States)

    Kim, Seung-Ju; Balce, Gracia Cielo; Agashe, Mandar Vikas; Song, Sang-Heon; Song, Hae-Ryong

    2012-02-01

    Use of the Ilizarov technique for limb lengthening in patients with achondroplasia is controversial, with a high risk of complications balancing cosmetic gains. Although several articles have described the complications of this procedure and satisfaction of patients after surgery, it remains unclear whether lengthening improves the quality of life (QOL) of these patients. We asked whether bilateral lower limb lengthenings with deformity correction in patients with achondroplasia would improve QOL and investigated the correlation between complication rate and QOL. We retrospectively reviewed 22 patients (average age, 12.7 years) diagnosed with achondroplasia who underwent bilateral lower limb lengthenings between 2002 and 2005. These patients were compared with 22 patients with achondroplasia for whom limb lengthening was not performed. The two groups were assessed using the American Academy of Orthopaedic Surgeons (AAOS) lower limb, SF-36, and Rosenberg self-esteem scores. Minimum followup was 4.5 years (range, 4.5-6.9 years). Among the lengthening group, the average gain in length was 10.21 ± 2.39 cm for the femur and 9.13 ± 2.12 cm for the tibia. A total of 123 complications occurred in these 88 segments. The surgical group had higher Rosenberg self-esteem scores than the nonsurgical group although there were no differences in the AAOS and the SF-36 scores. The self-esteem scores decreased with the increase in the number of complications. Our data suggest that despite frequent complications, bilateral lower limb lengthening increases patients' QOL. We believe lengthening is a reasonable option in selected patients. Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

  5. Slow-transit Constipation.

    Science.gov (United States)

    Bharucha, Adil E.; Philips, Sidney F.

    2001-08-01

    Idiopathic slow-transit constipation is a clinical syndrome predominantly affecting women, characterized by intractable constipation and delayed colonic transit. This syndrome is attributed to disordered colonic motor function. The disorder spans a spectrum of variable severity, ranging from patients who have relatively mild delays in transit but are otherwise indistinguishable from irritable bowel syndrome to patients with colonic inertia or chronic megacolon. The diagnosis is made after excluding colonic obstruction, metabolic disorders (hypothyroidism, hypercalcemia), drug-induced constipation, and pelvic floor dysfunction (as discussed by Wald ). Most patients are treated with one or more pharmacologic agents, including dietary fiber supplementation, saline laxatives (milk of magnesia), osmotic agents (lactulose, sorbitol, and polyethylene glycol 3350), and stimulant laxatives (bisacodyl and glycerol). A subtotal colectomy is effective and occasionally is indicated for patients with medically refractory, severe slow-transit constipation, provided pelvic floor dysfunction has been excluded or treated.

  6. Slowing Military Change

    Science.gov (United States)

    2008-10-01

    subjective. More objective measurements, such as statistics on youth crime, teenage pregnancy , drug use, literacy, and educational achievement...SLOWING MILITARY CHANGE Zhivan J. Alach October 2008 This publication is a work of the U.S. Government as defined in Title 17, United States Code...those of the author and do not necessarily reflect the official policy or position of the New Zealand Defence Force, the New Zealand Government , the

  7. Contribution of medications and risk factors to QTc interval lengthening in the atherosclerosis risk in communities (ARIC) study.

    Science.gov (United States)

    Alburikan, Khalid A; Aldemerdash, Ahmed; Savitz, Samuel T; Tisdale, James E; Whitsel, Eric A; Soliman, Elsayed Z; Thudium, Emily M; Sueta, Carla A; Kucharska-Newton, Anna M; Stearns, Sally C; Rodgers, Jo E

    2017-12-01

    Prolongation of the corrected QT (QTc) interval is associated with increased morbidity and mortality. The association between QTc interval-prolonging medications (QTPMs) and risk factors with magnitude of QTc interval lengthening is unknown. We examined the contribution of risk factors alone and in combination with QTPMs to QTc interval lengthening. The Atherosclerosis Risk in Communities study assessed 15 792 participants with a resting, standard 12-lead electrocardiogram and ≥1 measure of QTc interval over 4 examinations at 3-year intervals (1987-1998). From 54 638 person-visits, we excluded participants with QRS ≥ 120 milliseconds (n = 2333 person-visits). We corrected the QT interval using the Bazett and Framingham formulas. We examined QTc lengthening using linear regression for 36 602 person-visit observations for 14 160 cohort members controlling for age ≥ 65 years, female sex, left ventricular hypertrophy, QTc > 500 milliseconds at the prior visit, and CredibleMeds categorized QTPMs (Known, Possible, or Conditional risk). We corrected standard errors for repeat observations per person. Eighty percent of person-visits had at least one risk factor for QTc lengthening. Use of QTPMs increased over the 4 visits from 8% to 17%. Among persons not using QTPMs, history of prolonged QTc interval and female sex were associated with the greatest QTc lengthening, 39 and 12 milliseconds, respectively. In the absence of risk factors, Known QTPMs and ≥2 QTPMs were associated with modest but greater QTc lengthening than Possible or Conditional QTPMs. In the presence of risk factors, ≥2 QTPM further increased QTc lengthening. In combination with risk factors, the association of all QTPM categories with QTc lengthening was greater than QTPMs alone. Risk factors, particularly female sex and history of prolonged QTc interval, have stronger associations with QTc interval lengthening than any QTPM category alone. All QTPM categories augmented QTc interval

  8. Slow Food arjessa : Case Slow Food ruokakurssi Kristiinankaupungin Kansalaisopistossa

    OpenAIRE

    Mäenpää, Minna-Maria

    2015-01-01

    Opinnäytetyössäni esittelen Slow Food -järjestön toimintaa kansainvälisesti ja Slow Food -henkistä toimintaa Kristiinankaupungissa. Yhdistin teoriaosuuteen yhdessä Kristiinankaupungin kansalaisopiston ja Perunaelinkeinoalan kehittämishankkeen kanssa Kristiinankaupungissa järjestämäni Slow Food arjessa -kurssin. Tutkimuksen ongelmana oli luoda kurssikonsepti, jossa Slow Food -henkinen tiedottaminen esimerkiksi alueemme ruoantuottajista yhdistettiin varsinaiseen ruoan valmistamiseen. Keräsin tä...

  9. Sausage instabilities on top of kinking lengthening current-carrying magnetic flux tubes

    Science.gov (United States)

    von der Linden, Jens; You, Setthivoine

    2017-05-01

    We theoretically explore the possibility of sausage instabilities developing on top of a kink instability in lengthening current-carrying magnetic flux tubes. Observations indicate that the dynamics of magnetic flux tubes in our cosmos and terrestrial experiments can involve topological changes faster than time scales predicted by resistive magnetohydrodynamics. Recent laboratory experiments suggest that hierarchies of instabilities, such as kink and Rayleigh-Taylor, could be responsible for initiating fast topological changes by locally accessing two-fluid and kinetic regimes. Sausage instabilities can also provide this coupling mechanism between disparate scales. Flux tube experiments can be classified by the flux tube's evolution in a configuration space described by a normalized inverse aspect-ratio k ¯ and current-to-magnetic flux ratio λ ¯ . A lengthening current-carrying magnetic flux tube traverses this k ¯ - λ ¯ space and crosses stability boundaries. We derive a single general criterion for the onset of the sausage and kink instabilities in idealized magnetic flux tubes with core and skin currents. The criterion indicates a dependence of the stability boundaries on current profiles and shows overlapping kink and sausage unstable regions in the k ¯ - λ ¯ space with two free parameters. Numerical investigation of the stability criterion reduces the number of free parameters to a single one that describes the current profile and confirms the overlapping sausage and kink unstable regions in k ¯ - λ ¯ space. A lengthening, ideal current-carrying magnetic flux tube can therefore become sausage unstable after it becomes kink unstable.

  10. Go, Slow, and Whoa Foods

    Science.gov (United States)

    ... tips for seasonal health, safety and fun Go, Slow, and Whoa Foods Past Issues / Summer 2007 Table of Contents For ... Inc. 2002 Food Group GO Almost anytime foods SLOW Sometimes foods WHOA Once in a while foods Vegetables Almost ...

  11. Titration and hysteresis in epigenetic chromatin silencing

    Science.gov (United States)

    Dayarian, Adel; Sengupta, Anirvan M.

    2013-06-01

    Epigenetic mechanisms of silencing via heritable chromatin modifications play a major role in gene regulation and cell fate specification. We consider a model of epigenetic chromatin silencing in budding yeast and study the bifurcation diagram and characterize the bistable and the monostable regimes. The main focus of this paper is to examine how the perturbations altering the activity of histone modifying enzymes affect the epigenetic states. We analyze the implications of having the total number of silencing proteins, given by the sum of proteins bound to the nucleosomes and the ones available in the ambient, to be constant. This constraint couples different regions of chromatin through the shared reservoir of ambient silencing proteins. We show that the response of the system to perturbations depends dramatically on the titration effect caused by the above constraint. In particular, for a certain range of overall abundance of silencing proteins, the hysteresis loop changes qualitatively with certain jump replaced by continuous merger of different states. In addition, we find a nonmonotonic dependence of gene expression on the rate of histone deacetylation activity of Sir2. We discuss how these qualitative predictions of our model could be compared with experimental studies of the yeast system under anti-silencing drugs.

  12. Titration and hysteresis in epigenetic chromatin silencing

    International Nuclear Information System (INIS)

    Dayarian, Adel; Sengupta, Anirvan M

    2013-01-01

    Epigenetic mechanisms of silencing via heritable chromatin modifications play a major role in gene regulation and cell fate specification. We consider a model of epigenetic chromatin silencing in budding yeast and study the bifurcation diagram and characterize the bistable and the monostable regimes. The main focus of this paper is to examine how the perturbations altering the activity of histone modifying enzymes affect the epigenetic states. We analyze the implications of having the total number of silencing proteins, given by the sum of proteins bound to the nucleosomes and the ones available in the ambient, to be constant. This constraint couples different regions of chromatin through the shared reservoir of ambient silencing proteins. We show that the response of the system to perturbations depends dramatically on the titration effect caused by the above constraint. In particular, for a certain range of overall abundance of silencing proteins, the hysteresis loop changes qualitatively with certain jump replaced by continuous merger of different states. In addition, we find a nonmonotonic dependence of gene expression on the rate of histone deacetylation activity of Sir2. We discuss how these qualitative predictions of our model could be compared with experimental studies of the yeast system under anti-silencing drugs. (paper)

  13. The effect of plantar flexor lengthening on foot pressure in ambulatory children with cerebral palsy.

    Science.gov (United States)

    Abousamra, Oussama; Schwartz, Joshua; Church, Chris; Lennon, Nancy; Henley, John; Niiler, Tim; Miller, Freeman

    2018-05-01

    This study aimed to assess the effects of plantar flexor lengthening (PFL) on dynamic foot pressures of children with cerebral palsy using pedobarographs. Of 97 enrolled, 13 children with 18 legs had PFL. Age at surgery was 4.7 (2.8-8.8) years. A significant increase in ankle dorsiflexion and heel impulse was achieved postoperatively and was maintained at 5 years. The coronal plane pressure index increased postoperatively, but reverted to preoperative levels at the 5-year follow-up. Children tend to have more valgus after PFL. In young children, there caution should be exercised to avoid over treating varus at the time of equinus correction to avoid overcorrection.

  14. Fixator-Assisted Lengthening and Deformity Correction Over an Intramedullary Nail in a Patient with Achondroplasia

    Directory of Open Access Journals (Sweden)

    Erdal Uzun

    2014-12-01

    Full Text Available Achondroplasia is the most frequently encountered form of nonlethal skeletal dysplasia and a type of rhizomelic dwarfism. It results in considerable physical and psychologic handicaps owing to the disproportionate stature of the body and difficulty in performing routine activities of daily living. They also have major musculoskeletal problems including symptomatic malalignment of the lower limbs. Limb lengthening has been used in patients with achondroplasia by different techniques (Intramedullar nailing, monolateral or circular external fixator. We report our treatment of a patient 17 years of age with achondroplasia for bilateral lower limb length discrepancy and bilateral tibial varus deformity.

  15. Rf stability, control and bunch lengthening in electron synchrotron storage rings

    International Nuclear Information System (INIS)

    Wachtel, J.M.

    1989-09-01

    A self-consistent theory for nonlinear longitudinal particle motion and rf cavity excitation in a high energy electron storage ring is developed. Coupled first order equations for the motion of an arbitrary number of particles and for the field in several rf cavities are given in the form used in control system theory. Stochastic quantum excitation of synchrotron motion is included, as are the effects of rf control system corrections. Results of computations for double cavity bunch lengthening are given. 11 refs., 4 figs., 1 tab

  16. An analysis on forced eruption in crown lengthening of un-restorable teeth

    Directory of Open Access Journals (Sweden)

    Vahid A

    2004-07-01

    Full Text Available Cervical third root defects, like perforations (due to resoption or iatrogeic, fractures or invasive decays make great difficulties for appropriate restoration making. In these circumstances crown lengthening is needed, especially for anterior teeth. Forced eruption also could be a beneficial treatment. By this therapy, cervical third root defects will be available to receive a good restoration. without gum and biologic width problems. In this article tried to introduce this method of therapy by reviewing litraure and with regard to personal research.

  17. How does passive lengthening change the architecture of the human medial gastrocnemius muscle?

    Science.gov (United States)

    Bolsterlee, Bart; D'Souza, Arkiev; Gandevia, Simon C; Herbert, Robert D

    2017-04-01

    There are few comprehensive investigations of the changes in muscle architecture that accompany muscle contraction or change in muscle length in vivo. For this study, we measured changes in the three-dimensional architecture of the human medial gastrocnemius at the whole muscle level, the fascicle level and the fiber level using anatomical MRI and diffusion tensor imaging (DTI). Data were obtained from eight subjects under relaxed conditions at three muscle lengths. At the whole muscle level, a 5.1% increase in muscle belly length resulted in a reduction in both muscle width (mean change -2.5%) and depth (-4.8%). At the fascicle level, muscle architecture measurements obtained at 3,000 locations per muscle showed that for every millimeter increase in muscle-tendon length above the slack length, average fascicle length increased by 0.46 mm, pennation angle decreased by 0.27° (0.17° in the superficial part and 0.37° in the deep part), and fascicle curvature decreased by 0.18 m -1 There was no evidence of systematic variation in architecture along the muscle's long axis at any muscle length. At the fiber level, analysis of the diffusion signal showed that passive lengthening of the muscle increased diffusion along fibers and decreased diffusion across fibers. Using these measurements across scales, we show that the complex shape changes that muscle fibers, whole muscles, and aponeuroses of the medial gastrocnemius undergo in vivo cannot be captured by simple geometrical models. This justifies the need for more complex models that link microstructural changes in muscle fibers to macroscopic changes in architecture. NEW & NOTEWORTHY Novel MRI and DTI techniques revealed changes in three-dimensional architecture of the human medial gastrocnemius during passive lengthening. Whole muscle belly width and depth decreased when the muscle lengthened. Fascicle length, pennation, and curvature changed uniformly or near uniformly along the muscle during passive lengthening

  18. A dipstick sensor for coulometric acid-base titrations

    OpenAIRE

    Olthuis, Wouter; van der Schoot, B.H.; Chavez, F.; Bergveld, Piet

    1989-01-01

    By performing an acid-base titration by coulometric generation of OH− or H+ ions at an inert electrode in close proximity to the pH-sensitive gate of an ISFET, it is possible to determine the acid or base concentration of a solution using the ISFET as an indicator device for the equivalence point in the titration curve. Typical values for the titration time are 0.1 to 10 s for acid or base concentrations ranging from 0.5 × 10−3 to 10 × 10−3 mol/l. By placing the counter electrode for the supp...

  19. The fluorimetric titration of zirconium in the ppm-range

    International Nuclear Information System (INIS)

    Linden, W.E. von der; Boef, G. den; Ozinga, W.

    1976-01-01

    A fluorimetric titration of zirconium(IV) with EDTA is proposed. The fluorescence intensity of the zirconium-morin complex is used to indicate the end-point. More than twenty other cations were investigated and it was found that they did not interfere, neither did common anions. Mercury(II) can only be tolerated in amount not exceeding that of zirconium. Bismuth(III) interferes and hafnium(IV0 is titrated together with zirconium. The relative standard deviation of the titration of 10ml of a solution containing 1 ppm of zirconium does not exceed 1.5%

  20. Determination of boron as boric acid by automatic potentiometric titration

    International Nuclear Information System (INIS)

    Midgley, D.

    1988-06-01

    Boron in PWR primary coolant and related waters may be determined as boric acid by titration with sodium hydroxide, using a glass electrode as a pH indicator. With a modern automatic titrator, the analysis is quick, convenient, accurate and precise. In the titration of 8 mg B (e.g. 4 ml of 2000 mg 1 -1 solution), no significant bias was observed and relative standard deviations were about 0.25%. With 0.8 g B, a bias of about 2% appears, although this could be reduced by restandardizing the titrant, but the relative standard deviation was still -1 B, depending on the stage of the fuel cycle. (author)

  1. Green chemistry volumetric titration kit for pharmaceutical formulations: Econoburette

    Directory of Open Access Journals (Sweden)

    Man Singh

    2009-08-01

    Full Text Available Stopcock SC and Spring Sp models of Econoburette (Calibrated, RTC (NR, Ministry of Small Scale Industries, Government of India, developed for semimicro volumetric titration of pharmaceutical formulations are reported. These are economized and risk free titration where pipette is replaced by an inbuilt pipette and conical flask by inbuilt bulb. A step of pipetting of stock solution by mouth is deleted. It is used to allow solution exposure to user’s body. This risk is removed and even volatile and toxic solutions are titrated with full proof safety. Econoburette minimizes use of materials and time by 90 % and prevent discharge of polluting effluent to environment. Few acid and base samples are titrated and an analysis of experimental expenditure is described in the papers.

  2. Spectrophotometric titration of sulfates in the presence of zirconium

    International Nuclear Information System (INIS)

    Kuznetsov, V.V.; Kotova, S.S.; Molokanova, L.G.; Chekmarev, A.M.; Yagodin, G.A.

    1978-01-01

    The procedure has been proposed for express determination of sulphate ions in the presence of zirconium by spectrophotometric titration with the use of barium chloride and nitrochromazo as an indicator. The procedure is based on bonding zirconium into a more stable complex with EDTA (ethylenediaminotetraacetic acid). The presence of excess of EDTA and zirconium (4) complexonate in the solution being titrated does not affect the titration curve shape and the character of break on the curve in the equivalence point. A complete demasking of SO 4 2- is observed in the case of 1O-fold excess of EDTA with respect to zirconium (4). Statistic evaluation of the method has shown that the results of titration can be distorted by chance errors only

  3. Coulometric titration of niobium in 1F sulfuric acid

    International Nuclear Information System (INIS)

    Pannu, S.S.

    1975-01-01

    A coulometric titration at constant current has been devised for Nb in 1F sulfuric acid. The titration was based on the oxidation of Nb(III) to Nb(V) by Fe(III) electrogenerated at a graphite anode. Both potentiometric and amperometric end points were used. The Nb(V) was prior reduced at a mercury cathode by exhaustive electrolysis at a current density of 15 ma/mc 2 for at least 10 hr. Ta,V,Ti and a working platinum anode interfered, but the separation of the potentials of Nb(V)/Nb(III) and Ti(IV)/Ti(III) permitted the titration of first Nb and then Ti. The average error for the titration of 0.30 to 13.00 mg of niobium in 100 ml of 1F sulfuric acid was + 0.57%. (author)

  4. Potentiometric titration of free acid in uranium solutions

    Energy Technology Data Exchange (ETDEWEB)

    Suh, M. Y.; Kim, W. H.; Kim, J. S.; Sohn, S. C.; Eom, T. Y.; Lee, C. H.; Jeon, Y. S.; Han, S. H.

    1998-02-01

    Hydrolysis properties of metal cations and fundamental principles of the potentiometric titration of free acid in aqueous solutions containing metal cations were described. The published papers and reports for the alkalimetric and acidimetric titration of free acid were surveyed, and the applicability of these titration methods to the uranium and/or plutonium solutions were discussed. This technical report also includes the various results obtained from the authors` researches to establish the alkalimetric and acidimetric titration methods for the determination of free acid in nitric acid solutions containing uranium and/or oxalic acid, and aluminum. The procedure manuals used in chemical processes and the newly prepared manuals based on the authors` researches are appended. (author). 26 refs., 54 figs.

  5. Microscope Titration and Extraction of DNA from Liver.

    Science.gov (United States)

    Mayo, Lois T.; And Others

    1993-01-01

    Describes a simple and inexpensive, one-period activity to extract DNA to make the study of DNA less abstract. A microscope titration is used to determine when cells are ready for DNA extraction. (PR)

  6. A microcomputer-controlled system for titration analysis

    NARCIS (Netherlands)

    Boelema, Gerrit Jan

    1982-01-01

    This thesis deals with the results of the implementation of microprocessor technology in automatic titration equipment to obtain a versatile system for pharmaceutical, chemical analytical and optimization research purposes. ... Zie: Summary

  7. Analysis of the Purity of Cetrimide by Titrations

    DEFF Research Database (Denmark)

    Andersen, Jens Enevold Thaulov; Rasmussen, Claus/Dallerup; Nielsen, Hans/Boye

    2006-01-01

    The purity of cetrimide, trimethyl tetradecyl ammonium bromide (TTAB), that is an important preservative of many cosmetic and pharmaceutical products, was determined by three independent methods of titration. Traditionally, cetrimide was analysed by an assay method of the European Pharmacopoeia (Ph....... Eur.), which showed consistently a low purity of cetrimide with large standard deviations associated, however. A systematic 3% bias of the Ph. Eur. assay method was identified by comparing the result with results of two alternative methods of titration that exhibited high precision and high accuracy....... Titration by perchloric acid showed a 99.69 ± 0.05 % purity of cetrimide and titration by silver nitrate showed a 99.85% ± 0.05 % purity while the traditional assay method predicted a purity of only 97.1 ± 0.4. It was found that the discrepancy could be identified as differences in selectivity during...

  8. Plutonium volumetric titration after reduction on a Jones' column

    International Nuclear Information System (INIS)

    Description of a plutonium analysis method, in hydrochloric or sulfuric solution, for plutonium content over 2 mg, by reduction from plutonium IV to plutonium III in a Jones' column. Volumetic titration by ceric sulfate with ferrous orthophenanthroline [fr

  9. Double plication for spring-mediated intestinal lengthening of a defunctionalized Roux limb.

    Science.gov (United States)

    Dubrovsky, Genia; Huynh, Nhan; Thomas, Anne-Laure; Shekherdimian, Shant; Dunn, James C Y

    2017-12-26

    Spring-mediated distraction enterogenesis has been shown to increase the length of an intestinal segment. The goal of this study is to use suture plication to confine a spring within an intestinal segment while maintaining luminal patency to the rest of the intestine. Juvenile mini-Yucatan pigs underwent placement of nitinol springs within a defunctionalized Roux limb of jejunum. A 20 French catheter was passed temporarily, and sutures were used to plicate the intestinal wall around the catheter at both ends of the encapsulated spring. Uncompressed springs placed in plicated segments and springs placed in nonplicated segments served as controls. The intestine was examined approximately 3 weeks after spring placement. In the absence of plication, springs passed through the intestine within a week. Double plication allowed the spring to stay within the Roux limb for 3 weeks. Compared to uncompressed springs that showed no change in the length of plicated segments, compressed springs caused a significant 1.7-fold increase in the length of plicated segments. Intestinal plication is an effective method to confine endoluminal springs. The confined springs could lengthen intestine that maintains luminal patency. This approach may be useful to lengthen intestine in patients with short bowel syndrome. Level I Experimental Study. Copyright © 2018. Published by Elsevier Inc.

  10. Effect of distraction frequency on bone formation during bone lengthening: a study in chickens.

    Science.gov (United States)

    Mizuta, Hiroshi; Nakamura, Eiichi; Mizumoto, Yoshihiko; Kudo, Satoshi; Takagi, Katsumasa

    2003-12-01

    We compared the effects of two distraction frequencies on bone formation during tibial lengthening by evaluating radiographs, bone mineral density, and histological findings. In 15 mature White Leghorn chickens, both tibiae were distracted at a rate of 0.75 mm/day for 10 days. The distraction frequency was 2 steps (0.375 mm/12 hour) by hand on the right side and 120 steps (0.00625 mm/12 min) by autodistractor on the left. Serial radiographs showed faster bone formation on the 120-step side than on the 2-step side. Bone mineral density on the 120-step side was also higher than that on the 2-step side at all times. On the 2-step side, endochondral ossification was marked in the early stage of distraction; then intramembranous ossification became the main mechanism of bone formation. On the 120-step side, however, intramembranous bone formation predominated throughout the study. Our findings support the contention that, at least in skeletally mature chickens, an increase in the distraction frequency improves osteogenesis during bone lengthening.

  11. Distal fascia lata lengthening: an alternative surgical technique for recalcitrant trochanteric bursitis

    Science.gov (United States)

    Ortega, Javier; García-Rayo, Ramón; Resines, Carlos

    2009-01-01

    This article presents a simple technique for fascia lata lengthening that is less aggressive, can be performed under local anaesthetic with little morbidity and disability, and has excellent results. Eleven patients (13 hips) were enrolled in this study. Mean age was 54.6 years, there was one man and ten women. Outcomes were assessed by using a visual analog pain scale, Harris hip score and Lickert scale (satisfaction). There was a mean follow-up time of 43 months (range 15–84). All patients were scored by the Harris hip scale with a mean improvement from 61 (range 48–77) to 91 (range 76–95) after surgery. The mean visual analogue scale (VAS) score improved from 83 (range 60–99) to 13 (range 0–70). We had 12 of 13 patients reporting a good result. Mean surgical time was 15 min, and only one seroma was reported as a complication. No inpatient management was needed. In conclusion, distal “Z” lengthening of the fascia lata appears to be a good alternative for treatment of this condition. PMID:19214507

  12. Outcome of Low-Invasive Local Split-Thickness Lengthening for Iliotibial Band Friction Syndrome.

    Science.gov (United States)

    Inoue, Hiroaki; Hara, Kunio; Arai, Yuji; Nakagawa, Shuji; Kan, Hiroyuki; Hino, Manabu; Fujiwara, Hiroyoshi; Kubo, Toshikazu

    2018-02-01

    Conventional surgical methods for iliotibial band friction syndrome (ITBFS) may affect the iliotibial band (ITB), delaying return to sports activities or impeding performance. We have developed a minimally invasive method. This study retrospectively analyzed the outcomes of this procedure in individuals with ITBFS. This study included 34 knees of 31 individuals. Surgery involved lengthening the central part of the ITB by splitting it into a superficial and a deep layer, maintaining the anterior and posterior fibers immediately above the lateral epicondyle. Outcomes included time to resume sports activity, personal best times to run a 5000-m race before and after surgery, and 2-month post-surgery muscle strengths. The mean postoperative time to return to competition was 5.8 weeks. Personal best times of 5000-m race improved in 13 of 17 runners. Two months post-surgery, the mean extensor muscle strengths on the healthy and affected sides did not significantly differ nor did the flexor muscle strengths. In ITBFS, the ITB itself is normal. Lengthening the limited region of the ITB immediately above the lateral femoral epicondyle removes the cause of ITBFS, with a reduction in inflammation. This technique resulted in early return to competition without degrading performance. © Georg Thieme Verlag KG Stuttgart · New York.

  13. Y-duplication of the male urethra: use of anterior anorectal wall for posterior urethral lengthening.

    Science.gov (United States)

    Sinha, S; Sen, S; Chacko, J; Thomas, G; Karl, S; Mathai, J

    2006-06-01

    We have approached two patients with Y-duplication of the male urethra by a new two-staged technique to provide better results. A strip of anterior anorectal wall in continuity with the posterior urethra was used for posterior urethral lengthening and a tubed pedicled prepucial flap was used to reconstruct the anterior urethra without using the native urethra. This was done under a covering colostomy. After a gap of 6 months to allow for healing of the anorectum and to ensure adequate functioning of the perineal neourethra, second stage reconstruction was done using buried scrotal tube for the mid urethra along with colostomy closure. On follow-up at 8 and 12 months, respectively, both children were well with no stricture or fistula. There was normal anal continence and no stenosis. This technique tackles the problem in Y-duplication of the male urethra of lengthening the posterior urethral channel, which is often difficult to bring to the anterior half of the perineum especially if the opening is high up in the anorectum (case 2).

  14. Long term self esteem assessment after height increase by lengthening and then nailing.

    Science.gov (United States)

    Emara, K; Al Kersh, M A; Emara, A K

    2017-03-01

    The purpose of the study is to assess the long term psychosocial functioning after height increase, using the external fixation then nailing method. Rosenberg Self-esteem scale and a questionnaire to assess social functioning were completed by 28 patients both preoperatively and at a mean follow-up of 7 years. The mean total score of RSE self-esteem for the 28 patients before lengthening was 21.5 (SD 1.03) (20-24). The mean total score of RSE for the patients 1 year after lengthening was 22 (SD 1.17) (20-24) with highly significant difference (p = 0.002).The mean total RSE self-esteem score after 7 years was 21.7 (SD 1.12) (21-25) with no significant difference (p = 0.11) Improvement was an evident in the short term self esteem after 1 year of follow up of the patients with height increase. On the other hand, there was an evident deterioration in the long term psychosocial evaluation during follow up after 7 years of height increase, returning to near pre-operative levels of self esteem.

  15. Combined tibial lengthening and ankle arthrodesis for patients with certain type of sequelae of poliomyelitis.

    Science.gov (United States)

    Wu, Chi-Chuan

    2017-01-01

    Following far advancement of modern medicine and technology, functional disability in a certain type of sequelae of poliomyelitis may be effectively improved. Eight consecutive adult patients with unilateral sequelae of poliomyelitis were treated. These patients had shortened lower extremity of an average of 4.8 cm (range, 4.0-5.5 cm) in the lesion side. Muscle power of the ipsilateral knee was nearly intact (grade 4 or 5) but the ankle extension was completely flaccid. The tibia was osteotomized and lengthened with external fixation. Consequently, all external fixators were converted to plates supplemented with autogenous corticocancellous bone graft and bone graft substitute. Ankle arthrodesis was performed concomitantly. Seven patients were followed up for an average of 3.7 years (range, 2.2-5.4 years). All seven lengthened sites healed with an average union time of 3.9 months (range, 3.5-4.5 months) after plating. One ankle infection occurred. Gait function significantly improved by modified Mazur scoring evaluation ( p = 0.02). At the latest follow-up, all patients had a minimal or unnoticed limp in level walking. The described combined techniques may be an excellent alternate for treating selected patients with sequelae of poliomyelitis. The procedure is not complex but the efficiency is extremely prominent.

  16. Dissociation of weak acids during Gran plot free acidity titrations

    OpenAIRE

    Lindberg, Steven E:; Cole, Jan M.

    2011-01-01

    A comparison of weak and free acid concentrations measured by base titration and hydrogen ionactivities determined by direct pH measurement is described for several of our data sets for raincollected above and below a forest canopy in the eastern United States. These data illustrate theinfluence of weak acid dissociation during titration and the possible effect of activity coefficientson calculated free acid concentrations.DOI: 10.1111/j.1600-0889.1984.tb00240.x

  17. Amperometric titration of indium with edta solution in propanol

    International Nuclear Information System (INIS)

    Gevorgyan, A.M.; Talipov, Sh.T.; Khadeev, V.A.; Kostylev, V.S.; Khadeeva, L.A.

    1980-01-01

    Optimum conditions have been chosen for titration of indium with EDTA solution in anhydrous propanol and its mixtures with some aprotic solvents using amperometric and point detection. A procedure is suggested of determining indium microcontents in the presence of large amounts of other elements. The procedure is based on its extraction preseparation followed by direct titration in the extract with a standard EDTA solution [ru

  18. Carbon dioxide titration method for soil respiration measurements

    OpenAIRE

    Martín Rubio, Luis

    2017-01-01

    This thesis was commissioned by Tampere University of Applied Sciences, which was interested in studying and developing a titration measurement method for soil respiration and biodegradability. Some experiments were carried out measuring soil respiration for testing the method and others adding some biodegradable material like polylactic acid compressed material and 100% biodegradable plastic bags to test its biodegradability and the possibility to measure it via titration. The thesi...

  19. Potentiometric and coulometric titration of 2-thiobarbituric acid.

    Science.gov (United States)

    Ciesielski, W; Kowalska, J; Zakrzewski, R

    1995-05-01

    A new method for the determination of 2-thiobarbituric acid, using its reaction with iodine in an alkaline medium is presented. In the volumetric titration with potentiometric end-point detection, the determinability range is 10-400 micromol (1.4-58 mg). In coulometric titration using the biamperometric end-point detection, 0.1-20 micromol (1.4 x 10(-2)-2.9 mg) of 2-thiobarbituric acid was successfully determined.

  20. Non-damaging laser therapy of the macula: Titration algorithm and tissue response

    Science.gov (United States)

    Palanker, Daniel; Lavinsky, Daniel; Dalal, Roopa; Huie, Philip

    2014-02-01

    Retinal photocoagulation typically results in permanent scarring and scotomata, which limit its applicability to the macula, preclude treatments in the fovea, and restrict the retreatments. Non-damaging approaches to laser therapy have been tested in the past, but the lack of reliable titration and slow treatment paradigms limited their clinical use. We developed and tested a titration algorithm for sub-visible and non-damaging treatments of the retina with pulses sufficiently short to be used with pattern laser scanning. The algorithm based on Arrhenius model of tissue damage optimizes the power and duration for every energy level, relative to the threshold of lesion visibility established during titration (and defined as 100%). Experiments with pigmented rabbits established that lesions in the 50-75% energy range were invisible ophthalmoscopically, but detectable with Fluorescein Angiography and OCT, while at 30% energy there was only very minor damage to the RPE, which recovered within a few days. Patients with Diabetic Macular Edema (DME) and Central Serous Retinopathy (CSR) have been treated over the edematous areas at 30% energy, using 200μm spots with 0.25 diameter spacing. No signs of laser damage have been detected with any imaging modality. In CSR patients, subretinal fluid resolved within 45 days. In DME patients the edema decreased by approximately 150μm over 60 days. After 3-4 months some patients presented with recurrence of edema, and they responded well to retreatment with the same parameters, without any clinically visible damage. This pilot data indicates a possibility of effective and repeatable macular laser therapy below the tissue damage threshold.

  1. Gran method for end point anticipation in monosegmented flow titration

    Directory of Open Access Journals (Sweden)

    Aquino Emerson V

    2004-01-01

    Full Text Available An automatic potentiometric monosegmented flow titration procedure based on Gran linearisation approach has been developed. The controlling program can estimate the end point of the titration after the addition of three or four aliquots of titrant. Alternatively, the end point can be determined by the second derivative procedure. In this case, additional volumes of titrant are added until the vicinity of the end point and three points before and after the stoichiometric point are used for end point calculation. The performance of the system was assessed by the determination of chloride in isotonic beverages and parenteral solutions. The system employs a tubular Ag2S/AgCl indicator electrode. A typical titration, performed according to the IUPAC definition, requires only 60 mL of sample and about the same volume of titrant (AgNO3 solution. A complete titration can be carried out in 1 - 5 min. The accuracy and precision (relative standard deviation of ten replicates are 2% and 1% for the Gran and 1% and 0.5% for the Gran/derivative end point determination procedures, respectively. The proposed system reduces the time to perform a titration, ensuring low sample and reagent consumption, and full automatic sampling and titrant addition in a calibration-free titration protocol.

  2. Measurement of nucleotide exchange rate constants in single rabbit soleus myofibrils during shortening and lengthening using a fluorescent ATP analog.

    Science.gov (United States)

    Shirakawa, I; Chaen, S; Bagshaw, C R; Sugi, H

    2000-02-01

    The kinetics of displacement of a fluorescent nucleotide, 2'(3')-O-[N[2-[[Cy3]amido]ethyl]carbamoyl]-adenosine 5'-triphosphate (Cy3-EDA-ATP), bound to rabbit soleus muscle myofibrils were studied using flash photolysis of caged ATP. Use of myofibrils from this slow twitch muscle allowed better resolution of the kinetics of nucleotide exchange than previous studies with psoas muscle myofibrils (, Biophys. J. 73:2033-2042). Soleus myofibrils in the presence of Cy3-EDA-nucleotides (Cy3-EDA-ATP or Cy3-EDA-ADP) showed selective fluorescence staining of the A-band. The K(m) for Cy3-EDA-ATP and the K(d) for Cy3-EDA-ADP binding to the myofibril A-band were 1.9 microM and 3.8 microM, respectively, indicating stronger binding of nucleotide to soleus cross-bridges compared to psoas cross-bridges (2.6 microM and 50 microM, respectively). After flash photolysis of caged ATP, the A-band fluorescence of the myofibril in the Cy3-EDA-ATP solution under isometric conditions decayed exponentially with a rate constant of 0.045 +/- 0.007 s(-1) (n = 32) at 10 degrees C, which was about seven times slower than that for psoas myofibrils. When a myofibril was allowed to shorten with a constant velocity, the nucleotide displacement rate constant increased from 0.066 s(-1) (isometric) to 0.14 s(-1) at 20 degrees C with increasing shortening velocity up to 0.1 myofibril length/s (V(max), the shortening velocity under no load was approximately 0. 2 myofibril lengths/s). The rate constant was not significantly affected by an isovelocity stretch of up to 0.1 myofibril lengths/s. These results suggest that the cross-bridge kinetics are not significantly affected at higher strain during lengthening but depend on the lower strain during shortening. These data also indicate that the interaction distance between a cross-bridge and the actin filament is at least 16 nm for a single cycle of the ATPase.

  3. Tissue expander stimulated lengthening of arteries (TESLA) induces early endothelial cell proliferation in a novel rodent model.

    Science.gov (United States)

    Potanos, Kristina; Fullington, Nora; Cauley, Ryan; Purcell, Patricia; Zurakowski, David; Fishman, Steven; Vakili, Khashayar; Kim, Heung Bae

    2016-04-01

    We examine the mechanism of aortic lengthening in a novel rodent model of tissue expander stimulated lengthening of arteries (TESLA). A rat model of TESLA was examined with a single stretch stimulus applied at the time of tissue expander insertion with evaluation of the aorta at 2, 4 and 7day time points. Measurements as well as histology and proliferation assays were performed and compared to sham controls. The aortic length was increased at all time points without histologic signs of tissue injury. Nuclear density remained unchanged despite the increase in length suggesting cellular hyperplasia. Cellular proliferation was confirmed in endothelial cell layer by Ki-67 stain. Aortic lengthening may be achieved using TESLA. The increase in aortic length can be achieved without tissue injury and results at least partially from cellular hyperplasia. Further studies are required to define the mechanisms involved in the growth of arteries under increased longitudinal stress. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Bilateral humeral lengthening in achondroplasia with unilateral external fixators: is it safe and does it improve daily life?

    Science.gov (United States)

    Balci, H I; Kocaoglu, M; Sen, C; Eralp, L; Batibay, S G; Bilsel, K

    2015-11-01

    A retrospective study was performed in 18 patients with achondroplasia, who underwent bilateral humeral lengthening between 2001 and 2013, using monorail external fixators. The mean age was ten years (six to 15) and the mean follow-up was 40 months (12 to 104). The mean disabilities of the arm, shoulder and hand (DASH) score fell from 32.3 (20 to 40) pre-operatively to 9.4 (6 to 14) post-operatively (p = 0.037). A mean lengthening of 60% (40% to 95%) was required to reach the goal of independent perineal hygiene. One patient developed early consolidation, and fractures occurred in the regenerate bone of four humeri in three patients. There were three transient radial nerve palsies. Humeral lengthening increases the independence of people with achondroplasia and is not just a cosmetic procedure. ©2015 The British Editorial Society of Bone & Joint Surgery.

  5. Lengthening z-osteotomy of the fibula to correct persistent talar shift following open reduction internal fixation of ankle fractures.

    Science.gov (United States)

    Thangarajah, Tanujan; Lakdawala, Ayaz; Battaloglu, Emir; Malik, Atul; Tillu, Abhay

    2012-04-01

    In cases where ankle fracture union has been compromised by persistent syndesmotic diastasis following open reduction internal fixation, both external rotation and shortening of the fibula have been identified as prominent features. This study reports a technique that uses a z-osteotomy to achieve both lengthening and internal rotation of the fibula to correct persistent talar shift following ankle fracture fixation. Four patients with persistent talar shift following open reduction internal fixation for an ankle fracture received z-osteotomy of the fibula to achieve both lengthening and internal rotation. At the latest clinic review, all 4 ankles exhibited satisfactory clinical and radiological union. All patients have returned to full mobility and are satisfied with the outcome. This study demonstrates the effectiveness of lengthening z-osteotomy of the fibula in correcting persistent talar shift following internal fixation of ankle fractures. Therapeutic Level V.

  6. Humeral lengthening in patients with achondroplasia and in patients with post-septic shortening: comparison of procedure efficiency and safety.

    Science.gov (United States)

    Shadi, Milud; Musielak, Bartosz; Koczewski, Paweł; Janusz, Piotr

    2018-02-01

    Although humeral lengthening in patients with achondroplasia is an accepted procedure for improving functional status, there is still a paucity of information about the effectiveness of the method. Therefore, the aim of this study was to evaluate the efficacy and safety of humeral lengthening using monolateral fixators in patients with achondroplasia and unilateral shortening. Twenty-one patients (31 humeri) were included in this study. The study group consisted of eight patients with achondroplasia (16 segments). The control group consisted of 13 patients with post-septic shortening of the humerus (15 segments). All subjects underwent distraction osteogenesis with the use of a monolateral fixator. The mean lengthening in the patients with achondroplasia was 8.29 cm, whereas in the control group it was 7.34 cm (p = 0.1677). The mean lengthening percentage in the patients with achondroplasia (50% of the initial length of the humerus) was significantly greater than in the control group (33% of the initial length of the humerus) (p = 0.0007). The mean healing index was 24.8 days/cm in the patients with achondroplasia and 28.56 days/cm in the control group (p = 0.1832). The overall complication rates for the achondroplastic and post-septic patients were, respectively, 175% and 160% (p = 0.1420). Humeral lengthening with use of monolateral fixators in patients with achondroplasia is an efficient method. Although the segment lengthening percentage is significantly greater in patients with achondroplasia than in patients with post-septic shortening of the humerus, the safety of this procedure is comparable.

  7. Scintigraphic evaluation of bone lengthening by Ilizarov technique; Avaliacao cintigrafica do alongamento osseo pela tecnica de Ilizarov

    Energy Technology Data Exchange (ETDEWEB)

    Wolosker, Sara; Knackfuss, Irocy; Marchiori, Edson

    1996-07-01

    One of the main problems in limb lengthening is the difficulty on the assessment of the regenerated bone healing, since there are no reliable methods for its in vitro evaluation of restoration and mechanical integrity. New bone formation depends on the interaction between blood supply and mechanical distraction. The uptake of 99m-Tc-MDP has been shown to be a function of both regional blood flow and bone formation. Therefore, we propose the use of sequential three phase bone scans as another method in monitoring the regenerated bone formation in the Ilizarov technique of limb lengthening. Our preliminary results are shown in this paper. (author)

  8. Impact of Uniform Methods on Interlaboratory Antibody Titration Variability: Antibody Titration and Uniform Methods.

    Science.gov (United States)

    Bachegowda, Lohith S; Cheng, Yan H; Long, Thomas; Shaz, Beth H

    2017-01-01

    -Substantial variability between different antibody titration methods prompted development and introduction of uniform methods in 2008. -To determine whether uniform methods consistently decrease interlaboratory variation in proficiency testing. -Proficiency testing data for antibody titration between 2009 and 2013 were obtained from the College of American Pathologists. Each laboratory was supplied plasma and red cells to determine anti-A and anti-D antibody titers by their standard method: gel or tube by uniform or other methods at different testing phases (immediate spin and/or room temperature [anti-A], and/or anti-human globulin [AHG: anti-A and anti-D]) with different additives. Interlaboratory variations were compared by analyzing the distribution of titer results by method and phase. -A median of 574 and 1100 responses were reported for anti-A and anti-D antibody titers, respectively, during a 5-year period. The 3 most frequent (median) methods performed for anti-A antibody were uniform tube room temperature (147.5; range, 119-159), uniform tube AHG (143.5; range, 134-150), and other tube AHG (97; range, 82-116); for anti-D antibody, the methods were other tube (451; range, 431-465), uniform tube (404; range, 382-462), and uniform gel (137; range, 121-153). Of the larger reported methods, uniform gel AHG phase for anti-A and anti-D antibodies had the most participants with the same result (mode). For anti-A antibody, 0 of 8 (uniform versus other tube room temperature) and 1 of 8 (uniform versus other tube AHG), and for anti-D antibody, 0 of 8 (uniform versus other tube) and 0 of 8 (uniform versus other gel) proficiency tests showed significant titer variability reduction. -Uniform methods harmonize laboratory techniques but rarely reduce interlaboratory titer variance in comparison with other methods.

  9. The Role of ATRX in the Alternative Lengthening of Telomeres (ALT) Phenotype.

    Science.gov (United States)

    Amorim, João P; Santos, Gustavo; Vinagre, João; Soares, Paula

    2016-09-19

    Telomeres are responsible for protecting chromosome ends in order to prevent the loss of coding DNA. Their maintenance is required for achieving immortality by neoplastic cells and can occur by upregulation of the telomerase enzyme or through a homologous recombination-associated process, the alternative lengthening of telomeres (ALT). The precise mechanisms that govern the activation of ALT or telomerase in tumor cells are not fully understood, although cellular origin may favor one of the other mechanisms that have been found thus far in mutual exclusivity. Specific mutational events influence ALT activation and maintenance: a unifying frequent feature of tumors that acquire this phenotype are the recurrent mutations of the Alpha Thalassemia/Mental Retardation Syndrome X-Linked (ATRX) or Death-Domain Associated Protein (DAXX) genes. This review summarizes the established criteria about this phenotype: its prevalence, theoretical molecular mechanisms and relation with ATRX, DAXX and other proteins (directly or indirectly interacting and resulting in the ALT phenotype).

  10. [Treatment of facial paralysis with temporalis lengthening myoplasty and dysarthria improvement].

    Science.gov (United States)

    Laure, B; Fritz, A-H; Dufour, J; Goga, D

    2013-04-01

    The dysfunctions engendered by the peripheral facial paralysis (PFP) induce modifications of the verbal and para-verbal functions. The purpose of our study was to observe if the temporalis lengthening myoplasty (TLM) allowed to decrease dysarthria observed on the operated patients. We followed-up seven patients affected by a peripheral facial paralysis with various etiologies. Due to specifics needs of this study, we created an evaluation grid of the articulation, which allowed us to measure evolutions after the operation by a tri-phase evaluation: before surgery, at 3 and 6months after it. Results show a definite improvement of dysarthria in the whole test group. TLM operation, in addition to be very efficient for the recovering of the paralyzed side, can also treat dysarthria on these patients. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  11. Foot lengthening and shortening during gait: a parameter to investigate foot function?

    Science.gov (United States)

    Stolwijk, N M; Koenraadt, K L M; Louwerens, J W K; Grim, D; Duysens, J; Keijsers, N L W

    2014-02-01

    Based on the windlass mechanism theory of Hicks, the medial longitudinal arch (MLA) flattens during weight bearing. Simultaneously, foot lengthening is expected. However, changes in foot length during gait and the influence of walking speed has not been investigated yet. The foot length and MLA angle of 34 healthy subjects (18 males, 16 females) at 3 velocities (preferred, low (preferred -0.4 m/s) and fast (preferred +0.4 m/s) speed were investigated with a 3D motion analysis system (VICON(®)). The MLA angle was calculated as the angle between the second metatarsal head, the navicular tuberculum and the heel in the local sagittal plane. Foot length was calculated as the distance between the marker at the heel and the 2nd metatarsal head. A General Linear Model for repeated measures was used to indicate significant differences in MLA angle and foot length between different walking speeds. The foot lengthened during the weight acceptance phase of gait and shortened during propulsion. With increased walking speed, the foot elongated less after heel strike and shortened more during push off. The MLA angle and foot length curve were similar, except between 50% and 80% of the stance phase in which the MLA increases whereas the foot length showed a slight decrease. Foot length seems to represent the Hicks mechanism in the foot and the ability of the foot to bear weight. At higher speeds, the foot becomes relatively stiffer, presumably to act as a lever arm to provide extra propulsion. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. Characteristics of myogenic response and ankle torque recovery after lengthening contraction-induced rat gastrocnemius injury

    Directory of Open Access Journals (Sweden)

    Song Hongsun

    2012-10-01

    Full Text Available Abstract Background Although muscle dysfunction caused by unfamiliar lengthening contraction is one of most important issues in sports medicine, there is little known about the molecular events on regeneration process. The purpose of this study was to investigate the temporal and spatial expression patterns of myogenin, myoD, pax7, and myostatin after acute lengthening contraction (LC-induced injury in the rat hindlimb. Methods We employed our originally developed device with LC in rat gastrocnemius muscle (n = 24. Male Wistar rats were anesthetized with isoflurane (aspiration rate, 450 ml/min, concentration, 2.0%. The triceps surae muscle of the right hindlimb was then electrically stimulated with forced isokinetic dorsi-flexion (180°/sec and from 0 to 45°. Tissue contents of myoD, myogenin, pax7, myostatin were measured by western blotting and localizations of myoD and pax7 was measured by immunohistochemistry. After measuring isometric tetanic torque, a single bout of LC was performed in vivo. Results The torque was significantly decreased on days 2 and 5 as compared to the pre-treatment value, and recovered by day 7. The content of myoD and pax7 showed significant increases on day 2. Myogenin showed an increase from day 2 to 5. Myostatin on days 5 and 7 were significantly increased. Immunohistochemical analysis showed that myoD-positive/pax7-positive cells increased on day 2, suggesting that activated satellite cells play a role in the destruction and the early recovery phases. Conclusion We, thus, conclude that myogenic events associate with torque recovery after LC-induced injury.

  13. Coaxial slow source

    International Nuclear Information System (INIS)

    Brooks, R.D.; Jarboe, T.R.

    1990-01-01

    Field reversed configurations (FRCs) are a class of compact toroid with not toroidal field. The field reversed theta pinch technique has been successfully used for formation of FRCs since their inception in 1958. In this method an initial bias field is produced. After ionization of the fill gas, the current in the coil is rapidly reversed producing the radial implosion of a current sheath. At the ends of the coil the reversed field lines rapidly tear and reconnect with the bias field lines until no more bias flux remains. At this point, vacuum reversed field accumulates around the configuration which contracts axially until an equilibrium is reached. When extrapolating the use of such a technique to reactor size plasmas two main shortcomings are found. First, the initial bias field, and hence flux in a given device, which can be reconnected to form the configuration is limited from above by destructive axial dynamics. Second, the voltages required to produce rapid current reversal in the coil are very large. Clearly, a low voltage formation technique without limitations on flux addition is desirable. The Coaxial Slow Source (CSS) device was designed to meet this need. It has two coaxial theta pinch coils. Coaxial coil geometry allows for the addition of as much magnetic flux to the annular plasma between them as can be generated inside the inner coil. Furthermore the device can be operated at charging voltages less than 10 kV and on resistive diffusion, rather than implosive time scales. The inner coil is a novel, concentric, helical design so as to allow it to be cantilevered on one end to permit translation of the plasma. Following translation off the inner coil the Annular Field Reversed Configuration would be re-formed as a true FRC. In this paper we investigate the formation process in the new parallel configuration., CSSP, in which the inner and outer coils are connected in parallel to the main capacitor bank

  14. Potentiometric titration and equivalent weight of humic acid

    Science.gov (United States)

    Pommer, A.M.; Breger, I.A.

    1960-01-01

    The "acid nature" of humic acid has been controversial for many years. Some investigators claim that humic acid is a true weak acid, while others feel that its behaviour during potentiometric titration can be accounted for by colloidal adsorption of hydrogen ions. The acid character of humic acid has been reinvestigated using newly-derived relationships for the titration of weak acids with strong base. Re-interpreting the potentiometric titration data published by Thiele and Kettner in 1953, it was found that Merck humic acid behaves as a weak polyelectrolytic acid having an equivalent weight of 150, a pKa of 6.8 to 7.0, and a titration exponent of about 4.8. Interdretation of similar data pertaining to the titration of phenol-formaldehyde and pyrogallol-formaldehyde resins, considered to be analogs for humic acid by Thiele and Kettner, leads to the conclusion that it is not possible to differentiate between adsorption and acid-base reaction for these substances. ?? 1960.

  15. Myofascial force transmisison between antagonistic rat lower limb muscles: effects of single muscle or muscle group lengthening

    NARCIS (Netherlands)

    Meijer, Hanneke J.M; Rijkelijkhuizen, Josina M.; Huijing, P.A.J.B.M.

    2007-01-01

    Effects of lengthening of the whole group of anterior crural muscles (tibialis anterior and extensor hallucis longus muscles (TA + EHL) and extensor digitorum longus (EDL)) on myofascial interaction between synergistic EDL and TA + EHL muscles, and on myofascial force transmission between anterior

  16. Enhanced Corticospinal Excitability and Volitional Drive in Response to Shortening and Lengthening Strength Training and Changes Following Detraining

    NARCIS (Netherlands)

    Tallent, Jamie; Goodall, Stuart; Gibbon, Karl C.; Hortobagyi, Tibor; Howatson, Glyn

    2017-01-01

    There is a limited understanding of the neurological adaptations responsible for changes in strength following shortening and lengthening resistance training and subsequent detraining. The aim of the study was to investigate differences in corticospinal and spinal responses to resistance training of

  17. The effect of walking speed on hamstrings length and lengthening velocity in children with spastic cerebral palsy

    NARCIS (Netherlands)

    Krogt, van der M.M.; Doorenbosch, C.A.M.; Harlaar, J.

    2009-01-01

    0.001). These data are important as a reference for valid interpretation of hamstrings length and velocity data in gait analyses at different walking speeds. The results indicate that the presence of spasticity is associated with reduced hamstrings length and lengthening velocity during gait, even

  18. Myofascial force transmission between antagonistic rat lower limb muscles: Effects of single muscle or muscle group lengthening.

    NARCIS (Netherlands)

    Meijer, H.J.M.; Rijkelijkhuizen, J.M.; Huijing, P.A.J.B.M.

    2007-01-01

    Effects of lengthening of the whole group of anterior crural muscles (tibialis anterior and extensor hallucis longus muscles (TA + EHL) and extensor digitorum longus (EDL)) on myofascial interaction between synergistic EDL and TA + EHL muscles, and on myofascial force transmission between anterior

  19. Anterior ankle impingement after tendo-Achilles lengthening for long-standing equinus deformity in residual poliomyelitis.

    Science.gov (United States)

    Sung, Ki Hyuk; Chung, Chin Youb; Lee, Kyoung Min; Lee, Seung Yeol; Park, Moon Seok

    2013-09-01

    This study was performed to investigate anterior ankle impingement after tendo-Achilles lengthening for long-standing equinus deformity in patients with residual poliomyelitis and to investigate whether the severity of preoperative equinus deformity affected the occurrence of symptomatic anterior impingement. Twenty-seven consecutive patients (mean age, 43.8 ± 9.4 years) with residual poliomyelitis who underwent tendo-Achilles lengthening for equinus foot deformity were included. On lateral foot-ankle weight-bearing radiographs, the tibiocalcaneal angle, plantigrade angle, and McDermott grade were measured and the presence of anterior blocking spur was evaluated. Eleven patients (40.7%) had anterior ankle impingement on radiographic findings preoperatively and 24 patients (88.9%) at latest follow-up. There was a significant difference in McDermott grade between preoperative and latest follow-up (P poliomyelitis had anterior ankle impingement after tendo-Achilles lengthening for long-standing equinus deformity, and the presence of symptomatic anterior ankle impingement was significantly associated with the severity of the equinus deformity. Therefore, for residual poliomyelitis patients with severe long-standing equinus deformity, surgeons should consider the possibility of a subsequent anterior procedure for anterior impingement after tendo-Achilles lengthening. Level IV, retrospective case series.

  20. Growth disturbance after lengthening of the lower limb and quantitative assessment of physeal closure in skeletally immature patients with achondroplasia.

    Science.gov (United States)

    Song, S H; Kim, S E; Agashe, M V; Lee, H; Refai, M A; Park, Y E; Choi, H J; Park, J H; Song, H R

    2012-04-01

    This study evaluated the effect of limb lengthening on longitudinal growth in patients with achondroplasia. Growth of the lower extremity was assessed retrospectively by serial radiographs in 35 skeletally immature patients with achondroplasia who underwent bilateral limb lengthening (Group 1), and in 12 skeletally immature patients with achondroplasia who did not (Group 2). In Group 1, 23 patients underwent only tibial lengthening (Group 1a) and 12 patients underwent tibial and femoral lengthening sequentially (Group 1b). The mean lengthening in the tibia was 9.2 cm (59.5%) in Group 1a, and 9.0 cm (58.2%) in the tibia and 10.2 cm (54.3%) in the femur in Group 1b. The mean follow-up was 9.3 years (8.6 to 10.3). The final mean total length of lower extremity in Group 1a was 526.6 mm (501.3 to 552.9) at the time of skeletal maturity and 610.1 mm (577.6 to 638.6) in Group 1b, compared with 457.0 mm (411.7 to 502.3) in Group 2. However, the mean actual length, representing the length solely grown from the physis without the length of distraction, showed that there was a significant disturbance of growth after limb lengthening. In Group 1a, a mean decrease of 22.4 mm (21.3 to 23.1) (4.9%) was observed in the actual limb length when compared with Group 2, and a greater mean decrease of 38.9 mm (37.2 to 40.8) (8.5%) was observed in Group 1b when compared with Group 2 at skeletal maturity. In Group 1, the mean actual limb length was 16.5 mm (15.8 to 17.2) (3.6%) shorter in Group 1b when compared with Group 1a at the time of skeletal maturity. Premature physeal closure was seen mostly in the proximal tibia and the distal femur with relative preservation of proximal femur and distal tibia. We suggest that significant disturbance of growth can occur after extensive limb lengthening in patients with achondroplasia, and therefore, this should be included in pre-operative counselling of these patients and their parents.

  1. Determination of uranium by direct titration with dipicolinic acid

    International Nuclear Information System (INIS)

    Baumann, E.W.

    1984-01-01

    Direct titration of uranium with dipicolinic acid, in the presence of Arsenazo I, is a simple, precise, and accurate method for uranium determination. The method is particularly attractive because it can be totally automated. Detecting the end point (color change from blue to pink) depends on the concentration range. For the Micro Method (1 to 20 ppM U in the solution titrated), the gradual color change is monitored spectrophotometrically. For the Macro Method (20 to 300 ppM), the end point is determined either visually or spectrophotometrically. The spectrophotometric end point is computed by fitting the titration curve. The relative standard deviation is +-1 to 3% for the Micro Method and +-0.3% for the Macro Method

  2. Coulometric titration of D(+)-glucose using its enzymatic oxidation.

    Science.gov (United States)

    Tanaka, T; Shutto, E; Mizoguchi, T; Fukushima, K

    2001-02-01

    A definitive method is described for the indirect assay of milligram quantities of D(+)-glucose by coulometric titration. D(+)-Glucose was aerobically oxidized by glucose oxidase in an acetate buffer solution (pH 5.1). Subsequently, the enzymatically formed hydrogen peroxide was titrated coulometrically with electrogenerated hypobromite in sodium bromide-sodium tetraborate medium of pH 8.6, with biamperometric end-point detection. Parameters affecting the enzymatically catalyzed oxidation and coulometric titration were evaluated. The optimized conditions for the oxidation of up to 20 mg of D(+)-glucose include the addition of 4500 U of glucose oxidase and stirring over a 10-min interval at 25 degrees C. Under proposed conditions, the assay values of several commercial D(+)-glucose reagents were somewhat lower than the guaranteed minimum values, with RSDs (n = 5) of 0.071 - 0.106%.

  3. Error assessment in recombinant baculovirus titration: evaluation of different methods.

    Science.gov (United States)

    Roldão, António; Oliveira, Rui; Carrondo, Manuel J T; Alves, Paula M

    2009-07-01

    The success of baculovirus/insect cells system in heterologous protein expression depends on the robustness and efficiency of the production workflow. It is essential that process parameters are controlled and include as little variability as possible. The multiplicity of infection (MOI) is the most critical factor since irreproducible MOIs caused by inaccurate estimation of viral titers hinder batch consistency and process optimization. This lack of accuracy is related to intrinsic characteristics of the method such as the inability to distinguish between infectious and non-infectious baculovirus. In this study, several methods for baculovirus titration were compared. The most critical issues identified were the incubation time and cell concentration at the time of infection. These variables influence strongly the accuracy of titers and must be defined for optimal performance of the titration method. Although the standard errors of the methods varied significantly (7-36%), titers were within the same order of magnitude; thus, viral titers can be considered independent of the method of titration. A cost analysis of the baculovirus titration methods used in this study showed that the alamarblue, real time Q-PCR and plaque assays were the most expensive techniques. The remaining methods cost on average 75% less than the former methods. Based on the cost, time and error analysis undertaken in this study, the end-point dilution assay, microculture tetrazolium assay and flow cytometric assay were found to be the techniques that combine all these three main factors better. Nevertheless, it is always recommended to confirm the accuracy of the titration either by comparison with a well characterized baculovirus reference stock or by titration using two different methods and verification of the variability of results.

  4. Cortical and spinal excitability during and after lengthening contractions of the human plantar flexor muscles performed with maximal voluntary effort.

    Directory of Open Access Journals (Sweden)

    Daniel Hahn

    Full Text Available This study was designed to investigate the sites of potential specific modulations in the neural control of lengthening and subsequent isometric maximal voluntary contractions (MVCs versus purely isometric MVCs of the plantar flexor muscles, when there is enhanced torque during and following stretch. Ankle joint torque during maximum voluntary plantar flexion was measured by a dynamometer when subjects (n = 10 lay prone on a bench with the right ankle tightly strapped to a foot-plate. Neural control was analysed by comparing soleus motor responses to electrical nerve stimulation (M-wave, V-wave, electrical stimulation of the cervicomedullary junction (CMEP and transcranial magnetic stimulation of the motor cortex (MEP. Enhanced torque of 17 ± 8% and 9 ± 8% was found during and 2.5-3 s after lengthening MVCs, respectively. Cortical and spinal responsiveness was similar to that in isometric conditions during the lengthening MVCs, as shown by unchanged MEPs, CMEPs and V-waves, suggesting that the major voluntary motor pathways are not subject to substantial inhibition. Following the lengthening MVCs, enhanced torque was accompanied by larger MEPs (p ≤ 0.05 and a trend to greater V-waves (p ≤ 0.1. In combination with stable CMEPs, increased MEPs suggest an increase in cortical excitability, and enlarged V-waves indicate greater motoneuronal output or increased stretch reflex excitability. The new results illustrate that neuromotor pathways are altered after lengthening MVCs suggesting that the underlying mechanisms of the enhanced torque are not purely mechanical in nature.

  5. Distal femoral flexion deformity from growth disturbance treated with a two-level osteotomy and internal lengthening nail

    Directory of Open Access Journals (Sweden)

    Austin T. Fragomen

    2017-10-01

    Full Text Available Abstract Salter Harris fractures of the distal femur can lead to growth disturbance with resulting leg length inequality and knee deformity. We have looked at a case series (3 of patients who presented with a distal femur flexion malunion and shortening treated with a distal femoral osteotomy and plating and a proximal femoral osteotomy with a magnetic internal lengthening nail. Does a two-level osteotomy and internal fixation approach provide a reliable result both radiographically and functionally? The average knee extension loss was 12°, LLD 47 mm, PDFA 65°, MAD 2 mm. The patients were treated with an acute, posterior, opening wedge osteotomy of the distal femur stabilized with a lateral plate and screws and grafted with cancellous chips and putty. A second osteotomy was made proximally in the femur percutaneously, and the internal lengthening nail was inserted. Lengthening was done at approximately 1 mm/day. The average extension gain was 12°; amount of lengthening at the proximal site was 40 mm, LLD was 3 mm. The average PDFA was 81°, and MAD 3 mm. There were no complications. Functional results were excellent. Bone healing index was 24 days/cm. The average distance from the distal osteotomy to the joint line was 57 mm. The technique of two-level femur osteotomy stabilized with a plate and lengthening nail yielded excellent results with acceptable correction of deformity, full knee extension, and improved function. There were no complications including implant failure, infection, need for blood transfusion, knee stiffness, nonunion, compartment syndrome, or malunion.

  6. Potentiometric titration curves of aluminium salt solutions and its species conversion in the hydrolysis-polymerization course

    Directory of Open Access Journals (Sweden)

    Chenyi Wang

    2008-12-01

    Full Text Available A new concept of critical point is expounded by analysing the potentiometric titration curves of aluminium salt solutions under the moderate slow rate of base injection. The critical point is defined as the characteristic spot of the Al3+ salt solutions potentiometric titration curve, which is related to the experiment conditions. In addition, the changes of critical points reflect the influence of experiment conditions on the course of the hydrolysis-polymerization and the conversion of hydroxyl polynuclear aluminum species. According to the OH/Al mole ratio, the Al species can be divided into four regions quantitatively by three characteristic points on the titration curves: Part I, Al3+/Ala region, consist chiefly of Al3+ and mononuclear Al; Part II, the small/middle polynuclear Al region, including Al2-Al12; Part III, the large-size polynuclear aluminum region, consistent with predominantly Al13-Al54 and a little sol/gel Al(OH3; Part IV, the dissolving region of sol/gel Alc, only Al(OH 3 (aq or am and Al(OH4- species, which set up a base to study on the hydrolysis-polymerization of Al3+. At the same time, significant effects of total aluminum concentration, temperature, halide ion, silicate radical, and organic acid radical on the titration curves and its critical points were observed. Given the three critical points which demarcating the aluminum forms, we carry out a through investigation into the fundamental regulations of these factors’ influence, and offer a fresh train of thought to study the hydrolysis-polymerization of Al3+ in soil solutions.

  7. Potentiometric and coulometric titration of 6-propyl-2-thiouracil.

    Science.gov (United States)

    Ciesielski, W; Zakrzewski, R

    1997-05-01

    A method for the determination of 6-propyl-2-thiouracil involving its reaction with iodine in an alkaline medium is presented. In volumetric titration with potentiometric end-point detection, the range of determination is 125-500 mumol (21-85 mg). In coulometric titration using biamperometric end-point detection, 0.5-5.0 mumol (0.085-0.85 mg) of 6-propyl-2-thiouracil was successfully determined. The RSD in all applied techniques was < 1%. The methods developed were applied to the determination of 6-propyl-2-thiouracil in tablets.

  8. Construction and use of an optical semi-automatic titrator employing the technique of reflectance photometry

    International Nuclear Information System (INIS)

    Hwang, Hoon

    2001-01-01

    An optical semi-automatic titrator was constructed employing the technique of the reflectance spectrometry and was tested for the determination of the end points of the acid-base, precipitation, and EDTA titrations. And since the current optical semi-automatic titrator built on the principle of the reflectance spectrometry could be successfully used even for the determination of the end of the end point in the precipitation titration where the solid particles are formed during the titration process, it was found to be feasible that a completely automated optical titrator would be designed and built based on the current findings

  9. [Finite element analysis of the maxillary central incisor with traditional and modified crown lengthening surgery and post-core restoration in management of crown-root fracture].

    Science.gov (United States)

    Zhen, M; Wei, Y P; Hu, W J; Rong, Q G; Zhang, H

    2016-06-01

    To construct three-dimensional finite element models with modified crown lengthening surgery and post-core restoration in management of various crown-root fracture types, to investigate the intensity and distribution of stressin models mentioned above, and to compare and analyze the indications of traditional and modified crown lengthening surgeries from the mechanic point of view. Nine three-dimensional finite element models with modified crown lengthening surgery and post-core restoration were established and analyzed by micro-CT scanning technique, dental impression scanner, Mimics 10.0, Geomagic studio 9.0 and ANSYS 14.0 software. The von Mises stress of dentin, periodontal ligament, alveolar bone, post and core, as well as the periodontal ligament area and threshold limit value were calculated and compared with the findings of traditional crown lengthening models which had been published earlierby our research group. The von Mises stress intensity of modified crown lengthening models were: dentin>post>core>alveolar bone>periodontal ligament. The maximum von Mises stress of dentin(44.37-80.58 MPa)distributed in lingual central shoulder. The periodontal ligament area of the modified crown lengthening surgery was reduced by 6% to 28%, under the same crown-root fracture conditions, the periodontal ligament area of modified crown lengthening models was larger than that of the traditional crown lengthening models. In modified crown lengthening surgery models, the von Mises stress of periodontal ligament of B3L1m, B3L2m, B3L3m models exceeded their limit values, however, the von Mises stress of periodontal ligament of the B2L2c, B2L3c, B3L1c, B3L2c, B3L3c models exceeded their limit values in traditional crown lengthening surgery models. The modified crown lengthening surgery conserves more periodontal supporting tissues, which facilitates the long-term survival of teeth. The indication of modified crown lengthening surgery is wider than traditional method. The

  10. potentiometric titration curves of aluminium salt solutions and its

    African Journals Online (AJOL)

    a

    species, which set up a base to study on the hydrolysis-polymerization of Al3+. At the same time, significant effects of total aluminum concentration, temperature, halide ion, silicate radical, and organic acid radical on the titration curves and its critical points were observed. Given the three critical points which demarcating the ...

  11. Potentiometric titration curves of aluminium salt solutions and its ...

    African Journals Online (AJOL)

    At the same time, significant effects of total aluminum concentration, temperature, halide ion, silicate radical, and organic acid radical on the titration curves and its critical points were observed. Given the three critical points which demarcating the aluminum forms, we carry out a through investigation into the fundamental ...

  12. Acid/base titrations of simulated PWR crevice environments

    International Nuclear Information System (INIS)

    Pang, J.; Macdonald, D.D.; Millett, P.J.

    1993-01-01

    The construction and operation of a titration system that is capable of exploring the acid/base properties of aqueous systems at temperatures solution is measured using YSZ sensors of the type Hg/HgO/ZrO 2 (Y 2 O 3 )/Solution in conjunction with a suitable reference electrode. The use of the system for measuring the pH of the titrated solutions (NaOH/H 2 SO 4 ) is discussed, and we show that the YSZ pH sensor is capable of consistent and precise pH measurements at elevated temperature (275-325 degrees C) and pressures (100-150 bars). However, the accuracy of the measured pH depends critically on the performance of the reference electrode. In the present work, we ensure the viability of the reference electrode. In the present work, we ensure the viability of the reference electrode by periodically calibrating it in situ using the pH sensor and a standard solution of known pH versus temperature characteristics. The titration data obtained in this study are compared with predictions from EPRI's MULTEQ code, and are found to be in satisfactory agreement in the alkaline pH region. Observed discrepancies in the acidic pH region between the two sets of data are attributed to corrosion of the alloys used to fabricate the titration system

  13. A dipstick sensor for coulometric acid-base titrations

    NARCIS (Netherlands)

    Olthuis, Wouter; van der Schoot, B.H.; Chavez, F.; Bergveld, Piet

    1989-01-01

    By performing an acid-base titration by coulometric generation of OH− or H+ ions at an inert electrode in close proximity to the pH-sensitive gate of an ISFET, it is possible to determine the acid or base concentration of a solution using the ISFET as an indicator device for the equivalence point in

  14. Using Spreadsheets to Produce Acid-Base Titration Curves.

    Science.gov (United States)

    Cawley, Martin James; Parkinson, John

    1995-01-01

    Describes two spreadsheets for producing acid-base titration curves, one uses relatively simple cell formulae that can be written into the spreadsheet by inexperienced students and the second uses more complex formulae that are best written by the teacher. (JRH)

  15. Determination of Acidity Constants by Gradient Flow-Injection Titration

    Science.gov (United States)

    Conceicao, Antonio C. L.; Minas da Piedade, Manuel E.

    2006-01-01

    A three-hour laboratory experiment, designed for an advanced undergraduate course in instrumental analysis that illustrates the application of the gradient chamber flow-injection titration (GCFIT) method with spectrophotometric detection to determine acidity constants is presented. The procedure involves the use of an acid-base indicator to obtain…

  16. A General Simulator for Acid-Base Titrations

    Science.gov (United States)

    de Levie, Robert

    1999-07-01

    General formal expressions are provided to facilitate the automatic computer calculation of acid-base titration curves of arbitrary mixtures of acids, bases, and salts, without and with activity corrections based on the Davies equation. Explicit relations are also given for the buffer strength of mixtures of acids, bases, and salts.

  17. Developing and Demonstrating an Augmented Reality Colorimetric Titration Tool

    Science.gov (United States)

    Tee, Nicholas Yee Kwang; Gan, Hong Seng; Li, Jonathan; Cheong, Brandon Huey-Ping; Tan, Han Yen; Liew, Oi Wah; Ng, Tuck Wah

    2018-01-01

    The handling of chemicals in the laboratory presents a challenge in instructing large class sizes and when students are relatively new to the laboratory environment. In this work, we describe and demonstrate an augmented reality colorimetric titration tool that operates out of the smartphone or tablet of students. It allows multiple students to…

  18. Isothermal Titration Calorimetry Can Provide Critical Thinking Opportunities

    Science.gov (United States)

    Moore, Dale E.; Goode, David R.; Seney, Caryn S.; Boatwright, Jennifer M.

    2016-01-01

    College chemistry faculties might not have considered including isothermal titration calorimetry (ITC) in their majors' curriculum because experimental data from this instrumental method are often analyzed via automation (software). However, the software-based data analysis can be replaced with a spreadsheet-based analysis that is readily…

  19. Electroconvulsive therapy stimulus titration: Not all it seems.

    Science.gov (United States)

    Rosenman, Stephen J

    2018-05-01

    To examine the provenance and implications of seizure threshold titration in electroconvulsive therapy. Titration of seizure threshold has become a virtual standard for electroconvulsive therapy. It is justified as individualisation and optimisation of the balance between efficacy and unwanted effects. Present day threshold estimation is significantly different from the 1960 studies of Cronholm and Ottosson that are its usual justification. The present form of threshold estimation is unstable and too uncertain for valid optimisation or individualisation of dose. Threshold stimulation (lowest dose that produces a seizure) has proven therapeutically ineffective, and the multiples applied to threshold to attain efficacy have never been properly investigated or standardised. The therapeutic outcomes of threshold estimation (or its multiples) have not been separated from simple dose effects. Threshold estimation does not optimise dose due to its own uncertainties and the different short-term and long-term cognitive and memory effects. Potential harms of titration have not been examined. Seizure threshold titration in electroconvulsive therapy is not a proven technique of dose optimisation. It is widely held and practiced; its benefit and harmlessness assumed but unproven. It is a prematurely settled answer to an unsettled question that discourages further enquiry. It is an example of how practices, assumed scientific, enter medicine by obscure paths.

  20. Birth control - slow release methods

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/007555.htm Birth control - slow release methods To use the sharing features on this page, please enable JavaScript. Certain birth control methods contain man-made forms of hormones. ...

  1. Evaluation of modified boehm titration methods for use with biochars.

    Science.gov (United States)

    Fidel, Rivka B; Laird, David A; Thompson, Michael L

    2013-11-01

    The Boehm titration, originally developed to quantify organic functional groups of carbon blacks and activated carbons in discrete pK ranges, has received growing attention for analyzing biochar. However, properties that distinguish biochar from carbon black and activated carbon, including greater carbon solubility and higher ash content, may render the original Boehm titration method unreliable for use with biochars. Here we use seven biochars and one reference carbon black to evaluate three Boehm titration methods that use (i) acidification followed by sparging (sparge method), (ii) centrifugation after treatment with BaCl (barium method), and (iii) a solid-phase extraction cartridge followed by acidification and sparging (cartridge method) to remove carbonates and dissolved organic compounds (DOC) from the Boehm extracts before titration. Our results for the various combinations of Boehm reactants and methods indicate that no one method was free of bias for all three Boehm reactants and that the cartridge method showed evidence of bias for all pK ranges. By process of elimination, we found that a combination of the sparge method for quantifying functional groups in the lowest pK range (∼5 to 6.4), and the barium method for quantifying functional groups in the higher pK ranges (∼6.4 to 10.3 and ∼10.3 to 13) to be free of evidence for bias. We caution, however, that further testing is needed and that all Boehm titration results for biochars should be considered suspect unless efforts were undertaken to remove ash and prevent interference from DOC. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  2. Glycogen synthase kinase-3β haploinsufficiency lengthens the circadian locomotor activity period in mice.

    Science.gov (United States)

    Lavoie, Joëlle; Hébert, Marc; Beaulieu, Jean-Martin

    2013-09-15

    The mood stabiliser drug lithium has been reported to impact circadian rhythms in vertebrates. Among several putative therapeutic molecular targets, direct inhibition of glycogen synthase kinase-3 beta (GSK3β) by lithium has been proposed to underlie its effects on circadian physiology. Here we study the effect of GSK3β haploinsufficiency on the circadian locomotor activity in mice during a free-running period in comparison to wildtype littermates (WT). Mice were housed individually to record their circadian wheel running activity and were entrained to a 12h light/12h dark cycle for 14 days and then placed under constant darkness for 14 days to allow free-running. During the free-running phase, the circadian locomotor activity period of GSK3β(+/-) was significantly lengthened (23.83±0.05h) when compared to the WT mice (23.54±0.10h; p=0.0374). No significant difference in locomotor activity was observed. Knowing that GSK3β interacts with most of the core clock components, these data suggest that GSK3β acts as a critical intrinsic regulator of the circadian clock and plays an important role in regulating its period in response to lithium treatment. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. Alternative Lengthening of Telomeres: Recurrent Cytogenetic Aberrations and Chromosome Stability under Extreme Telomere Dysfunction

    Directory of Open Access Journals (Sweden)

    Despoina Sakellariou

    2013-11-01

    Full Text Available Human tumors using the alternative lengthening of telomeres (ALT exert high rates of telomere dysfunction. Numerical chromosomal aberrations are very frequent, and structural rearrangements are widely scattered among the genome. This challenging context allows the study of telomere dysfunction-driven chromosomal instability in neoplasia (CIN in a massive scale. We used molecular cytogenetics to achieve detailed karyotyping in 10 human ALT neoplastic cell lines.We identified 518 clonal recombinant chromosomes affected by 649 structural rearrangements. While all human chromosomes were involved in random or clonal, terminal, or pericentromeric rearrangements and were capable to undergo telomere healing at broken ends, a differential recombinatorial propensity of specific genomic regions was noted.We show that ALT cells undergo epigenetic modifications rendering polycentric chromosomes functionally monocentric, and because of increased terminal recombinogenicity, they generate clonal recombinant chromosomes with interstitial telomeric repeats. Losses of chromosomes 13, X, and 22, gains of 2, 3, 5, and 20, and translocation/deletion events involving several common chromosomal fragile sites (CFSs were recurrent. Long-term reconstitution of telomerase activity in ALT cells reduced significantly the rates of random ongoing telomeric and pericentromeric CIN. However, the contribution of CFS in overall CIN remained unaffected, suggesting that in ALT cells whole-genome replication stress is not suppressed by telomerase activation. Our results provide novel insights into ALT-driven CIN, unveiling in parallel specific genomic sites that may harbor genes critical for ALT cancerous cell growth.

  4. Case reports: the influence of selective voluntary motor control on gait after hamstring lengthening surgery.

    Science.gov (United States)

    Goldberg, Evan J; Fowler, Eileen G; Oppenheim, William L

    2012-05-01

    Preliminary evidence suggests selective voluntary motor control (SVMC), defined as performance of isolated voluntary joint movement on request, may be an important factor affecting functional movement tasks. Individuals with poor SVMC are unable to dissociate hip and knee synergistic movement during the swing phase of gait and have difficulty extending their knee while the hip is flexing during terminal swing regardless of hamstring length. This pattern may limit their ability to take advantage of hamstring-lengthening surgery (HLS) and may explain a lack of improved stride length postoperatively. Provide a preliminary clinical and conceptual framework for using SVMC to predict swing phase parameters of gait after HLS. We contrasted two patients with spastic diplegia of similar age, gross motor function, and spasticity but with different SVMC scores using the Selective Control Assessment of the Lower Extremity (SCALE). The patients underwent bilateral HLS. Popliteal angles, joint kinematics, step length, stride length, and walking velocity were assessed pre- and postoperatively. Popliteal angles, terminal knee extension, and knee range of motion improved for both patients. However, only the patient with higher SCALE scores improved stride length postoperatively. Although preliminary, the data suggest that SVMC, as measured by SCALE, may be a prognostic factor for improved stride length after HLS in patients with spastic diplegia. Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

  5. Lengthening of the growing season in wheat and maize producing regions

    Directory of Open Access Journals (Sweden)

    Brigitte Mueller

    2015-09-01

    Full Text Available Human-induced increases in atmospheric greenhouse gas concentrations have led to rising global temperatures. Here we investigate changes in an annual temperature-based index, the growing season length, defined as the number of days with temperature above 5 °C. We show that over extratropical regions where wheat and maize are harvested, the increase in growing season length from 1956 to 2005 can be attributed to increasing greenhouse gas concentrations. Our analyses also show that climate change has increased the probability of extremely long growing seasons by a factor of 25, and decreased the probability of extremely short growing seasons. A lengthening of the growing season in regions with these mostly rain-fed crops could improve yields, provided that water availability does not become an issue. An expansion of areas with more than 150 days of growing season into the northern latitudes makes more land potentially available for planting wheat and maize. Furthermore, double-cropping can become an alternative to current practices in areas with very long growing seasons which are also shown to increase with a warming climate. These results suggest that there is a strong impact of anthropogenic climate change on growing season length. However, in some regions and with further exacerbated climate change, high temperatures may already be or may become a limiting factor for plant productivity.

  6. Molecular and Morphologic Correlates of the Alternative Lengthening of Telomeres Phenotype in High Grade Astrocytomas

    Science.gov (United States)

    Nguyen, Doreen N.; Heaphy, Christopher M.; de Wilde, Roeland F.; Orr, Brent A.; Odia, Yazmin; Eberhart, Charles G.; Meeker, Alan K.; Rodriguez, Fausto J.

    2013-01-01

    Recent studies suggest that the telomere maintenance mechanism known as Alternative Lengthening of Telomeres (ALT) is relatively more common in specific glioma subsets and strongly associated with ATRX mutations. We retrospectively examined 116 high grade astrocytomas (32 pediatric glioblastomas, 65 adult glioblastomas,19 anaplastic astrocytomas) with known ALT status using tissue microarrays to identify associations with molecular and phenotypic features. Immunohistochemistry was performed using antibodies against ATRX, DAXX, p53 and IDH1R132H mutant protein. EGFR amplification was evaluated by FISH. When focusing on histologic subtypes, almost half of fibrillary and gemistocytic astrocytomas (44%) demonstrated ALT. Conversely all gliosarcomas (n=4), epithelioid (n=2), giant cell (n=2) and adult small cell astrocytomas (n=7) were ALT negative. The ALT phenotype was positively correlated with the presence of round cells (p=0.002), microcysts (p<0.0002), IDH1 mutant protein (p<0.0001), ATRX protein loss (p<0.0001), strong P53 expression (p<0.0001), and absence of EGFR amplification (p=0.004). There was no significant correlation with DAXX expression. We conclude that ALT represents a specific phenotype in high grade astrocytomas with distinctive pathologic and molecular features. Future studies are required to clarify the clinical and biological significance of ALT in high grade astrocytomas, and its possible utility as a diagnostic and/or therapeutic target. PMID:22928601

  7. Molecular and morphologic correlates of the alternative lengthening of telomeres phenotype in high-grade astrocytomas.

    Science.gov (United States)

    Nguyen, Doreen N; Heaphy, Christopher M; de Wilde, Roeland F; Orr, Brent A; Odia, Yazmin; Eberhart, Charles G; Meeker, Alan K; Rodriguez, Fausto J

    2013-05-01

    Recent studies suggest that the telomere maintenance mechanism known as alternative lengthening of telomeres (ALT) is relatively more common in specific glioma subsets and strongly associated with ATRX mutations. We retrospectively examined 116 high-grade astrocytomas (32 pediatric glioblastomas, 65 adult glioblastomas, 19 anaplastic astrocytomas) with known ALT status using tissue microarrays to identify associations with molecular and phenotypic features. Immunohistochemistry was performed using antibodies against ATRX, DAXX, p53 and IDH1(R132H) mutant protein. EGFR amplification was evaluated by fluorescence in situ hybridization (FISH). Almost half of fibrillary and gemistocytic astrocytomas (44%) demonstrated ALT. Conversely all gliosarcomas (n = 4), epithelioid (n = 2), giant cell (n = 2) and adult small cell astrocytomas (n = 7) were ALT negative. The ALT phenotype was positively correlated with the presence of round cells (P = 0.002), microcysts (P < 0.0002), IDH1 mutant protein (P < 0.0001), ATRX protein loss (P < 0.0001), strong P53 immunostaining (P < 0.0001) and absence of EGFR amplification (P = 0.004). There was no significant correlation with DAXX expression. We conclude that ALT represents a specific phenotype in high-grade astrocytomas with distinctive pathologic and molecular features. Future studies are required to clarify the clinical and biological significance of ALT in high-grade astrocytomas. © 2012 The Authors; Brain Pathology © 2012 International Society of Neuropathology.

  8. Significantly lengthened telomere in granulosa cells from women with polycystic ovarian syndrome (PCOS).

    Science.gov (United States)

    Wei, Duo; Xie, Juanke; Yin, Baoli; Hao, Haoying; Song, Xiaobing; Liu, Qi; Zhang, Cuilian; Sun, Yingpu

    2017-07-01

    Polycystic ovary syndrome (PCOS) is the most common endocrinopathy among women at reproductive age. However, its etiology remains poorly understood. Recent studies indicated that telomere length was related to PCOS. However, the association between telomere length and PCOS has only been shown in leucocytes and remained controversial across different studies. To clarify the association between telomere length and PCOS, the current study interrogated telomere length not only in leucocytes, but also in follicular granulosa cells, which is essential for folliculogenesis and steroidogenesis. Seventy-five patients with PCOS and 81 controls with mechanical infertility undergoing their first in vitro fertilization cycle were enrolled. Their peripheral blood and granulosa cells were collected on the oocyte retrieval day. Telomere length of both leucocytes in the blood and granulosa cells was assayed by quantitative polymerase chain reaction. No significant difference was found in the leucocyte telomere length between controls and PCOS patients (0.99 ± 0.44 vs. 1.00 ± 0.38, p = 0.93). Interestingly, when comparing telomere length in granulosa cells between controls and PCOS subjects, significantly lengthened telomere length was found in PCOS subjects (1.00 ± 0.37 vs. 1.57±0.67, p PCOS. Given the importance of telomere length in cellular proliferation, our findings provided novel insights into the pathophysiology of PCOS that abnormalities in telomere length possibly disturb folliculogenesis and subsequently result in PCOS.

  9. Anthraquinones quinizarin and danthron unwind negatively supercoiled DNA and lengthen linear DNA

    International Nuclear Information System (INIS)

    Verebová, Valéria; Adamcik, Jozef; Danko, Patrik; Podhradský, Dušan; Miškovský, Pavol; Staničová, Jana

    2014-01-01

    Highlights: • Anthraquinones quinizarin and danthron unwind negatively supercoiled DNA. • Anthraquinones quinizarin and danthron lengthen linear DNA. • Anthraquinones quinizarin and danthron possess middle binding affinity to DNA. • Anthraquinones quinizarin and danthron interact with DNA by intercalating mode. - Abstract: The intercalating drugs possess a planar aromatic chromophore unit by which they insert between DNA bases causing the distortion of classical B-DNA form. The planar tricyclic structure of anthraquinones belongs to the group of chromophore units and enables anthraquinones to bind to DNA by intercalating mode. The interactions of simple derivatives of anthraquinone, quinizarin (1,4-dihydroxyanthraquinone) and danthron (1,8-dihydroxyanthraquinone), with negatively supercoiled and linear DNA were investigated using a combination of the electrophoretic methods, fluorescence spectrophotometry and single molecule technique an atomic force microscopy. The detection of the topological change of negatively supercoiled plasmid DNA, unwinding of negatively supercoiled DNA, corresponding to appearance of DNA topoisomers with the low superhelicity and an increase of the contour length of linear DNA in the presence of quinizarin and danthron indicate the binding of both anthraquinones to DNA by intercalating mode

  10. Anthraquinones quinizarin and danthron unwind negatively supercoiled DNA and lengthen linear DNA

    Energy Technology Data Exchange (ETDEWEB)

    Verebová, Valéria [Institute of Biophysics, University of Veterinary Medicine and Pharmacy, Komenského 73, 041 81 Košice (Slovakia); Adamcik, Jozef [Food and Soft Materials Science, Institute of Food, Nutrition and Health, ETH Zurich, Schmelzbergstrasse 9, CH-8092 Zürich (Switzerland); Danko, Patrik; Podhradský, Dušan [Department of Biochemistry, Institute of Chemistry, Faculty of Sciences, P.J. Šafárik University, Moyzesova 11, 041 54 Košice (Slovakia); Miškovský, Pavol [Department of Biophysics, Faculty of Sciences, P.J. Šafárik University, Jesenná 5, 041 54 Košice (Slovakia); Center for Interdisciplinary Biosciences, Faculty of Sciences, P.J. Šafárik University, Jesenná 5, 041 54 Košice (Slovakia); Staničová, Jana, E-mail: jana.stanicova@uvlf.sk [Institute of Biophysics, University of Veterinary Medicine and Pharmacy, Komenského 73, 041 81 Košice (Slovakia)

    2014-01-31

    Highlights: • Anthraquinones quinizarin and danthron unwind negatively supercoiled DNA. • Anthraquinones quinizarin and danthron lengthen linear DNA. • Anthraquinones quinizarin and danthron possess middle binding affinity to DNA. • Anthraquinones quinizarin and danthron interact with DNA by intercalating mode. - Abstract: The intercalating drugs possess a planar aromatic chromophore unit by which they insert between DNA bases causing the distortion of classical B-DNA form. The planar tricyclic structure of anthraquinones belongs to the group of chromophore units and enables anthraquinones to bind to DNA by intercalating mode. The interactions of simple derivatives of anthraquinone, quinizarin (1,4-dihydroxyanthraquinone) and danthron (1,8-dihydroxyanthraquinone), with negatively supercoiled and linear DNA were investigated using a combination of the electrophoretic methods, fluorescence spectrophotometry and single molecule technique an atomic force microscopy. The detection of the topological change of negatively supercoiled plasmid DNA, unwinding of negatively supercoiled DNA, corresponding to appearance of DNA topoisomers with the low superhelicity and an increase of the contour length of linear DNA in the presence of quinizarin and danthron indicate the binding of both anthraquinones to DNA by intercalating mode.

  11. [The Temporal Smile. Speech therapy for facial palsy patients after temporal lengthening myoplasty].

    Science.gov (United States)

    Lambert-Prou, M-P

    2003-10-01

    We present our approach to speech therapy developed for patients with definitive peripheral facial palsy treated by temporal lengthening myoplasty. The main goal is to rehabilitate smiling function, a major component in social communication codes, by transferring labial and jugal functions to the transferred temporal muscle. Several phases are involved. The first phase, termed the Mandibular Smile involves mobilization of the mandible (original function of the temporal) by contraction of the transferred temporal and inducing an elevation of the commissura labiorum. The second phase, the Voluntary Temporal Smile is obtained by contraction of the temporal independently of mandibular movement which remains under voluntary control. The smile produces should become as symmetrical as possible. Finally, the last phase is designed to achieve a spontaneous smile independent of mandibular movement Spontaneous Temporal Smile. Temporal contraction should produce both a "real" expressive smile and good quality articulate speech, saliva evacuation, prehension, and labial junction. Acquisition of the Temporal Smile involves cerebral plasticity implying rehabilitation processes both on the peripheral and central levels.

  12. Technique tip: Simultaneous first metatarsal lengthening and metatarsophalangeal joint fusion for failed hallux valgus surgery with transfer metatarsalgia.

    Science.gov (United States)

    Chowdhary, Ashwin; Drittenbass, Lisca; Stern, Richard; Assal, Mathieu

    2017-03-01

    Failed hallux valgus surgery may result in residual or recurrent hallux valgus, and as well transfer metatarsalgia. The present technical tip concerns the combination of fusion of the first metatarsophalangeal (MTP) joint and lengthening of the first metatarsal (MT) through a scarf osteotomy. Six patients underwent the presented technique, all for the indication of failed hallux valgus surgery with shortening of the first MT and degenerative changes in the 1st MTP joint. Follow-up at six months revealed all patients had complete healing of the osteotomy and arthrodesis sites. They were all asymptomatic and fully active, completely satisfied with the outcome. Combined fusion of the first MTP joint and lengthening of the first MT through a scarf osteotomy results in an excellent outcome in patients with failed hallux valgus surgery with shortening of the first MT and degenerative changes in the 1st MTP joint. Copyright © 2016 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.

  13. Management of large class II lesions in molars: how to restore and when to perform surgical crown lengthening?

    Directory of Open Access Journals (Sweden)

    Ana Belén Dablanca-Blanco

    2017-08-01

    Full Text Available The restoration of endodontic tooth is always a challenge for the clinician, not only due to excessive loss of tooth structure but also invasion of the biological width due to large decayed lesions. In this paper, the 7 most common clinical scenarios in molars with class II lesions ever deeper were examined. This includes both the type of restoration (direct or indirect and the management of the cavity margin, such as the need for deep margin elevation (DME or crown lengthening. It is necessary to have the DME when the healthy tooth remnant is in the sulcus or at the epithelium level. For caries that reaches the connective tissue or the bone crest, crown lengthening is required. Endocrowns are a good treatment option in the endodontically treated tooth when the loss of structure is advanced.

  14. The Potential of/for 'Slow': Slow Tourists and Slow Destinations

    Directory of Open Access Journals (Sweden)

    J. Guiver

    2016-05-01

    Full Text Available Slow tourism practices are nothing new; in fact, they were once the norm and still are for millions of people whose annual holiday is spent camping, staying in caravans, rented accommodation, with friends and relations or perhaps in a second home, who immerse themselves in their holiday environment, eat local food, drink local wine and walk or cycle around the area. So why a special edition about slow tourism? Like many aspects of life once considered normal (such as organic farming or free-range eggs, the emergence of new practices has highlighted differences and prompted a re-evaluation of once accepted practices and values. In this way, the concept of ‘slow tourism’ has recently appeared as a type of tourism that contrasts with many contemporary mainstream tourism practices. It has also been associated with similar trends already ‘branded’ slow: slow food and cittaslow (slow towns and concepts such as mindfulness, savouring and well-being.

  15. Novel application of HA-TCP biomaterials in distraction osteogenesis shortened the lengthening time and promoted bone consolidation.

    Science.gov (United States)

    Wang, Yan; Ni, Ming; Tang, Pei-Fu; Li, Gang

    2009-04-01

    This study tested the hypothesis that use of biomaterials in distraction osteogenesis (DO) would reduce the treatment time and enhance bone formation quality. A 1.0-cm tibial shaft was removed in the left tibia of 36 rabbits. Rabbits were randomly divided into three groups: group A, the defect gap was reduced with the tibia shortened for 1.0-cm; group B, the defect gap was filled with 1.0-cm restorable porous hydroxyapatite and Tri-calcium phosphates cylindrical block (HA/TCP block, diameter is 0.5-cm); group C, The 1.0-cm defect gap was reduced 0.5 cm and the remaining 0.5-cm defect gap was filled with the 0.5-cm HA/TCP block. The tibia was then fixed with unilateral lengthener; for groups A and C; lengthening started 7 days after surgery at a rate of 1.0 mm/day, in two steps. Group A received lengthening for 10 days and group C for 5 days, there was no lengthening for group B. All animals were terminated at day 37 following surgery. The excised bone specimens were subject to microcomputed tomography (micro-CT), mechanical testing, and histological examinations. Bone mineral density and content and tissue mineral density and content, as well as the mechanical properties of the regenerates were significantly higher in group C compared to groups A and B. Micro-CT and histological examinations also confirmed that the regenerates in Group C had most advanced bone formation, consolidation, and remodeling compared to other groups. In conclusion, the combined use of biomaterials and DO technique can reduce the treatment time and enhance bone consolidation in bone defect management.

  16. Treatment of infected non union tibia: A novel technique - lengthening using limb reconstruction system over intramedullary nail

    Directory of Open Access Journals (Sweden)

    Mahantesh Y Patil

    2013-01-01

    Full Text Available Background: To assess combination of an intramedullary interlocking (IMIL nail with limb reconstruction system (LRS in cases of infected nonunion tibia and to show influence of nail in predicting good outcome. Materials and Methods: From 2009 to 2011, records of 20 patients (17 men and three women aged 18 to 65 years (mean, 38.4 years with infected nonunion of the tibia treated with the LRS over IMIL Nail technique were prospectively reviewed. According to Jain et al., patients were classified into five cases of A1, five cases of type A2, seven cases of type B1, and three cases of type B2. All cases underwent LRS and IMIL. Mean amount of target lengthening was 54.65 mm. The mean follow-up was 14 months. Results: Mean amount of tibia lengthening was 51.70 mm. Leg length equalization was achieved in 19 cases (±5. According to modified scoring by Paley et al., 12 patients had excellent results, three patients had good, four patients had fair outcome, and one patient had poor outcome. Mean distraction index was 0.97. Mean maturation index was 2.43. Mean consolidation index was 3.47. Mean healing index was 1.40. One case had proximal locking screw failure. One case developed pre mature consolidation as distraction was started at delayed period due to non-compliance. Two cases developed decreased dorsi flexion of ankle. Two cases required flap surgeries for cover of bone. One case had pin breakage, which had to be exchanged. One case developed re-infection. Conclusion: The advantages of this technique include complete eradication of infective foci, reduced risk of deformity during lengthening, decrease risk of fractures post external fixator removal and reduction of time required for external fixator use thus decreasing healing index: Number of days of external fixation required per centimetre of lengthening.

  17. Union Rates and Complications of Lateral Column Lengthening Using the Interposition Plating Technique: A Radiographic and Medical Record Review.

    Science.gov (United States)

    Foster, James R; McAlister, Jeffrey E; Peterson, Kyle S; Hyer, Christopher F

    Lateral column lengthening is a common procedure for correction of pes planovalgus. A tricortical bone graft has been a standard among foot and ankle surgeons. The purpose of the present study was to compare the union rates and complications between the 2 forms of fixation for lateral column lengthening. The present study was a retrospective medical record and radiograph review of 52 patients divided into 2 equal groups, allograft (group A) and opening wedge plate (group B). The radiographic analyses compared the preoperative, postoperative and long-term measurements of cuboid abduction and talonavicular angles. The outcome measures included nonunion, hardware removal, and infection. The median follow-up duration for each group was 34.5 (range 6.3 to 89.5) months and 12.6 (range 6.5 to 56.8) months for groups A and B, respectively. Group A had 4 nonunions (15.4%) and group B had 2 nonunions (7.7%). The mean radiographic measurements of cuboid abduction and talonavicular articulation for each group improved significantly. The incidence of hardware removal was greater for group A than for group B (30.8% versus 15.4%), although the difference was not statistically significant. The median time to osseous healing for group A was 12.0 (range 8.0 to 80.0) weeks and for group B was 10.0 (range 6.0 to 36.0) weeks. The interposition plating techniques for lateral column lengthening procedures had a lower nonunion rate and incidence of hardware removal compared with the traditional use of tricortical bone grafting. The findings from the present study will aid surgeons in alternative fixation for lateral column lengthening procedures. Copyright © 2016 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  18. Colloid Titration--A Rapid Method for the Determination of Charged Colloid.

    Science.gov (United States)

    Ueno, Keihei; Kina, Ken'yu

    1985-01-01

    "Colloid titration" is a volumetric method for determining charged polyelectrolytes in aqueous solutions. The principle of colloid titration, reagents used in the procedure, methods of endpoint detection, preparation of reagent solutions, general procedure used, results obtained, and pH profile of colloid titration are considered. (JN)

  19. The Acid-Base Titration of a Very Weak Acid: Boric Acid

    Science.gov (United States)

    Celeste, M.; Azevedo, C.; Cavaleiro, Ana M. V.

    2012-01-01

    A laboratory experiment based on the titration of boric acid with strong base in the presence of d-mannitol is described. Boric acid is a very weak acid and direct titration with NaOH is not possible. An auxiliary reagent that contributes to the release of protons in a known stoichiometry facilitates the acid-base titration. Students obtain the…

  20. Acidity titration curves - a versatile tool for the characterisation of acidic mine waste water

    International Nuclear Information System (INIS)

    Fyson, A.

    2000-01-01

    Acidity titrations with NaOH are valuable tools for characterisation of acidic mine waters. - Titrations can be used to estimate metal concentrations. - Titrations can be carried out in the field, minimising changes in water chemistry due to sample handling time and procedure. (orig.)

  1. Slow rupture of frictional interfaces

    Science.gov (United States)

    Bar Sinai, Yohai; Brener, Efim A.; Bouchbinder, Eran

    2012-02-01

    The failure of frictional interfaces and the spatiotemporal structures that accompany it are central to a wide range of geophysical, physical and engineering systems. Recent geophysical and laboratory observations indicated that interfacial failure can be mediated by slow slip rupture phenomena which are distinct from ordinary, earthquake-like, fast rupture. These discoveries have influenced the way we think about frictional motion, yet the nature and properties of slow rupture are not completely understood. We show that slow rupture is an intrinsic and robust property of simple non-monotonic rate-and-state friction laws. It is associated with a new velocity scale cmin, determined by the friction law, below which steady state rupture cannot propagate. We further show that rupture can occur in a continuum of states, spanning a wide range of velocities from cmin to elastic wave-speeds, and predict different properties for slow rupture and ordinary fast rupture. Our results are qualitatively consistent with recent high-resolution laboratory experiments and may provide a theoretical framework for understanding slow rupture phenomena along frictional interfaces.

  2. Effects of lengthening the speech signal on auditory word discrimination in kindergartners with SLI

    NARCIS (Netherlands)

    Segers, P.C.J.; Verhoeven, L.T.W.

    2005-01-01

    In the present study, it was investigated whether kindergartners with specific language impairment (SLI) and normallanguage achieving (NLA) kindergartners can benefit from slowing down the entire speech signal or part of the speech signal in a synthetic speech discrimination task. Subjects were 19

  3. Making Time for Nature: Visual Exposure to Natural Environments Lengthens Subjective Time Perception and Reduces Impulsivity.

    Directory of Open Access Journals (Sweden)

    Meredith S Berry

    opposed to built environments may be related to lengthened time perception.

  4. Alternative mechanisms of telomere lengthening: Permissive mutations, DNA repair proteins and tumorigenic progression

    Energy Technology Data Exchange (ETDEWEB)

    Gocha, April Renee Sandy; Harris, Julia [Department of Molecular Virology, Immunology and Medical Genetics, The Ohio State University College of Medicine, Columbus, OH 43210 (United States); Groden, Joanna, E-mail: joanna.groden@osumc.edu [Department of Molecular Virology, Immunology and Medical Genetics, The Ohio State University College of Medicine, Columbus, OH 43210 (United States)

    2013-03-15

    Highlights: ► Neoplastic cells maintain telomeres by telomerase or ALT. ► Genetic mutations in p53, ATRX, DAXX or H3F3A may activate ALT. ► Many DNA repair proteins are involved in ALT. ► Tumor progression is favored by telomerase expression. - Abstract: Telomeres protect chromosome termini to maintain genomic stability and regulate cellular lifespan. Maintenance of telomere length is required for neoplastic cells after the acquisition of mutations that deregulate cell cycle control and increase cellular proliferation, and can occur through expression of the enzyme telomerase or in a telomerase-independent manner termed alternative lengthening of telomeres (ALT). The precise mechanisms that govern the activation of ALT or telomerase in tumor cells are unknown, although cellular origin may favor one or the other mechanisms. ALT pathways are incompletely understood to date; however, recent publications have increasingly broadened our understanding of how ALT is activated, how it proceeds, and how it influences tumor growth. Specific mutational events influence ALT activation, as mutations in genes that suppress recombination and/or alterations in the regulation of telomerase expression are associated with ALT. Once engaged, ALT uses DNA repair proteins to maintain telomeres in the absence of telomerase; experiments that manipulate the expression of specific proteins in cells using ALT are illuminating some of its mechanisms. Furthermore, ALT may influence tumor growth, as experimental and clinical data suggest that telomerase expression may favor tumor progression. This review summarizes recent findings in mammalian cells and models, as well as clinical data, that identify the genetic mutations permissive to ALT, the DNA repair proteins involved in ALT mechanisms and the importance of telomere maintenance mechanisms for tumor progression. A comprehensive understanding of the mechanisms that permit tumor cell immortalization will be important for identifying

  5. Levator lengthening technique using cartilage or fascia graft for paralytic lagophthalmos in facial paralysis.

    Science.gov (United States)

    Hayashi, Ayato; Yoshizawa, Hidekazu; Natori, Yuhei; Senda, Daiki; Tanaka, Rica; Mizuno, Hiroshi

    2016-05-01

    Lid loading using gold weights has been commonly used to treat paralytic lagophthalmos (PL); however, the procedure has a relatively high complication rate and the availability of these plates varies among social circumstances. We used a levator lengthening (LL) technique, which originally elongated the levator aponeurosis by inserting a fascia graft between the edge of the levator aponeurosis and the tarsal plate. However, because this procedure tends to result in a wide residual lagophthalmos, we changed the graft material from fascia to conchal cartilage. In this study, we describe in detail our experience with LL using the cartilage graft. LL was performed in 18 patients with PL. Fascia grafts were used in seven patients and cartilage grafts in 11. Static reconstructions of the lower eyelid and eyebrow were also performed in most patients. Efficacy was evaluated from patient reports of ocular symptoms and by measuring the palpebral fissure width at opening and closing for both eyes. All patients experienced improved ophthalmological symptoms, which were more apparent in cartilage cases. The average palpebral fissure at eyelid closure was 1.8 mm in cartilage cases and 4.0 mm in fascia cases. In cases where an eyebrow lift was concurrently performed, the residual lagophthalmos became wider in fascia grafting but remained acceptable in cartilage grafting. LL is a simple and useful procedure for treating PL with higher efficacy when a cartilage graft is used. However, the level of the upper eyelid can be easily adjusted by changing the fixation position of the cartilage. Additional experience is required to obtain more consistent outcomes. Copyright © 2016 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  6. Making Time for Nature: Visual Exposure to Natural Environments Lengthens Subjective Time Perception and Reduces Impulsivity.

    Science.gov (United States)

    Berry, Meredith S; Repke, Meredith A; Nickerson, Norma P; Conway, Lucian G; Odum, Amy L; Jordan, Kerry E

    2015-01-01

    environments may be related to lengthened time perception.

  7. Telomere Length Maintenance in Cancer: At the Crossroad between Telomerase and Alternative Lengthening of Telomeres (ALT).

    Science.gov (United States)

    De Vitis, Marco; Berardinelli, Francesco; Sgura, Antonella

    2018-02-18

    Eukaryotic cells undergo continuous telomere shortening as a consequence of multiple rounds of replications. During tumorigenesis, cells have to acquire telomere DNA maintenance mechanisms (TMMs) in order to counteract telomere shortening, to preserve telomeres from DNA damage repair systems and to avoid telomere-mediated senescence and/or apoptosis. For this reason, telomere maintenance is an essential step in cancer progression. Most human tumors maintain their telomeres expressing telomerase, whereas a lower but significant proportion activates the alternative lengthening of telomeres (ALT) pathway. However, evidence about the coexistence of ALT and telomerase has been found both in vivo in the same cancer populations and in vitro in engineered cellular models, making the distinction between telomerase- and ALT-positive tumors elusive. Indeed, after the development of drugs able to target telomerase, the capability for some cancer cells to escape death, switching from telomerase to ALT, was highlighted. Unfortunately, to date, the mechanism underlying the possible switching or the coexistence of telomerase and ALT within the same cell or populations is not completely understood and different factors could be involved. In recent years, different studies have tried to shed light on the complex regulation network that controls the transition between the two TMMs, suggesting a role for embryonic cancer origin, epigenetic modifications, and specific genes activation-both in vivo and in vitro. In this review, we examine recent findings about the cancer-associated differential activation of the two known TMMs and the possible factors implicated in this process. Furthermore, some studies on cancers are also described that did not display any TMM.

  8. [Lengthening temporalis myoplasty: A new approach to facial rehabilitation with the "mirror-effect" method].

    Science.gov (United States)

    Blanchin, T; Martin, F; Labbe, D

    2013-12-01

    Peripheral facial paralysis often reveals two conditions that are hard to control: labial occlusion and palpebral closure. Today, there are efforts to go beyond the sole use of muscle stimulation techniques, and attention is being given to cerebral plasticity stimulation? This implies using the facial nerves' efferent pathway as the afferent pathway in rehabilitation. This technique could further help limit the two recalcitrant problems, above. We matched two groups of patients who underwent surgery for peripheral facial paralysis by lengthening the temporalis myoplasty (LTM). LTM is one of the best ways to examine cerebral plasticity. The trigeminal nerve is a mixed nerve and is both motor and sensory. After a LTM, patients have to use the trigeminal nerve differently, as it now has a direct role in generating the smile. The LTM approach, using the efferent pathway, therefore, creates a challenge for the brain. The two groups followed separate therapies called "classical" and "mirror-effect". The "mirror-effect" method gave a more precise orientation of the patient's cerebral plasticity than did the classical rehabilitation. The method develops two axes: voluntary movements patients need to control their temporal smile; and spontaneous movements needed for facial expressions. Work on voluntary movements is done before a "digital mirror", using an identical doubled hemiface, providing the patient with a fake copy of his face and, thus, a 7 "mirror-effect". The spontaneous movements work is based on what we call the "Therapy of Motor Emotions". The method presented here is used to treat facial paralysis (Bell's Palsies type), whether requiring surgery or not. Importantly, the facial nerve, like the trigeminal nerve above, is also a mixed nerve and is stimulated through the efferent pathway in the same manner. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  9. Pulsar slow-down epochs

    International Nuclear Information System (INIS)

    Heintzmann, H.; Novello, M.

    1981-01-01

    The relative importance of magnetospheric currents and low frequency waves for pulsar braking is assessed and a model is developed which tries to account for the available pulsar timing data under the unifying aspect that all pulsars have equal masses and magnetic moments and are born as rapid rotators. Four epochs of slow-down are distinguished which are dominated by different braking mechanisms. According to the model no direct relationship exists between 'slow-down age' and true age of a pulsar and leads to a pulsar birth-rate of one event per hundred years. (Author) [pt

  10. Determination of uranium by a gravimetric-volumetric titration method

    International Nuclear Information System (INIS)

    Krtil, J.

    1998-01-01

    A volumetric-gravimetric modification of a method for the determination of uranium based on the reduction of uranium to U (IV) in a phosphoric acid medium and titration with a standard potassium dichromate solution is described. More than 99% of the stoichiometric amount of the titrating solution is weighed and the remainder is added volumetrically by using the Mettler DL 40 RC Memotitrator. Computer interconnected with analytical balances collects continually the data on the analyzed samples and evaluates the results of determination. The method allows to determine uranium in samples of uranium metal, alloys, oxides, and ammonium diuranate by using aliquot portions containing 30 - 100 mg of uranium with the error of determination, expressed as the relative standard deviation, of 0.02 - 0.05%. (author)

  11. Slow pseudoperiodic lateralized epileptiform discharges in nonconvulsive status epilepticus in a patient with cerebral palsy and a large central meningioma

    Directory of Open Access Journals (Sweden)

    Y.Z. Imam

    2014-01-01

    Full Text Available The presence of cerebral palsy and that of slow growing brain tumors are risk factors for convulsive and nonconvulsive status epilepticus. Nonconvulsive status epilepticus (NCSE needs electroencephalographic (EEG monitoring to be confirmed as it may be clinically subtle. Furthermore, it may present with a variety of ictal EEG morphologies. We report a case of a patient with cerebral palsy and a large central meningioma. Electroencephalogram showed a slow pattern of periodic lateralized epileptiform discharges (PLEDs (a pattern considered as being situated in the ictal–interictal continuum on an alpha background. The patient was treated for NCSE successfully with benzodiazepines followed by up-titration of his antiepileptic drug doses.

  12. Association of interleukin-6 signalling with the muscle stem cell response following muscle-lengthening contractions in humans.

    Directory of Open Access Journals (Sweden)

    Bryon R McKay

    Full Text Available BACKGROUND: The regulation of muscle stem cells in humans in response to muscle injury remains largely undefined. Recently, interleukin-6 (IL-6 has been implicated in muscle stem cell (satellite cell-mediated muscle hypertrophy in animals; however, the role of IL-6 in the satellite cell (SC response following muscle-lengthening contractions in humans has not been studied. METHODOLOGY/PRINCIPAL FINDINGS: Eight subjects (age 22+/-1 y; 79+/-8 kg performed 300 maximal unilateral lengthening contractions (3.14 rad.s(-1 of the knee extensors. Blood and muscle samples were collected before and at 4, 24, 72, and 120 hours post intervention. IL-6, IL-6 receptor, IL-6R(alpha, cyclin D1, suppressor of cytokine signling-3 (SOCS3 mRNA were measured using quantitative RT-PCR and serum IL-6 protein was measured using an ELISA kit. JAK2 and STAT3 phosphorylated and total protein was measured using western blotting techniques. Immunohistochemical analysis of muscle cross-sections was performed for the quantification of SCs (Pax7(+ cells as well as the expression of phosphorylated STAT3, IL-6, IL-6R(alpha, and PCNA across all time-points. The SC response, as defined by an amplification of Pax7(+ cells, was rapid, increasing by 24 h and peaking 72 h following the intervention. Muscle IL-6 mRNA increased following the intervention, which correlated strongly (R(2 = 0.89, p<0.002 with an increase in serum IL-6 concentration. SC IL-6R(alpha protein was expressed on the fiber, but was also localized to the SC, and IL-6(+ SC increased rapidly following muscle-lengthening contractions and returned to basal levels by 72 h post-intervention, demonstrating an acute temporal expression of IL-6 with SC. Phosphorylated STAT3 was evident in SCs 4 h after lengthening contraction, and the downstream genes, cyclin D1 and SOCS3 were significantly elevated 24 hours after the intervention. CONCLUSIONS/SIGNIFICANCE: The increased expression of STAT3 responsive genes and expression of

  13. Analysis of the Purity of Cetrimide by Titrations

    DEFF Research Database (Denmark)

    Andersen, Jens Enevold Thaulov; Rasmussen, Claus/Dallerup; Nielsen, Hans/Boye

    2006-01-01

    The purity of cetrimide, trimethyl tetradecyl ammonium bromide (TTAB), that is an important preservative of many cosmetic and pharmaceutical products, was determined by three independent methods of titration. Traditionally, cetrimide was analysed by an assay method of the European Pharmacopoeia (Ph...... the extraction step of the Ph. Eur.-assay method. The distribution coefficients between chloroform and water of cetrimide and the corresponding iodide species (TTAI) were thus determined as 2150 ± 50 M-1 and 68000 ± 4000 M-1, respectively....

  14. Interaction of molybdenum (6) with potassium benzyldithiocarbaminate during amperometric titration

    International Nuclear Information System (INIS)

    Galushko, S.V.; Usatenko, Yu.I.

    1975-01-01

    The paper is an amperometric study of the mechanism of interaction between molybdenum (VI) and potassium benzyl dithiocarbamate [BDTC] which was based on the use of voltamperometry, electron paramagnetic resonance, infrared spectroscopy, potentiometry and elemental analysis. In amperometric titration Mo(VI) with BDTC (pH 4-2) forms a red compound of low solubility. In more acidic media the intensity of coloration is increased and a violet hue develops. On the basis of the data obtained it is concluded that in the amperometric titration of Mo(VI) with potassium BDTC there is first formation of a Mo(VI) compound, which subsequently acquires a red colour as a result of the reduction of Mo(VI) to Mo(V). It was also established that the degree of reduction is small where titration is carried out in the range pH 4.8-0.1. Quantitative determination of Mo is performed most effectively in slightly acidic media. Mo reacts with potassium BDTC in a ratio of 1:2. (E.P.)

  15. Cell titration assay for measuring blastogenesis of bovine lymphocytes.

    Science.gov (United States)

    Baldwin, C L; Antczak, D F; Winter, A J

    1985-08-01

    The blastogenic response of bovine peripheral blood lymphocytes to phytohemagglutinin (PHA) and to microbial antigens was measured using a lymphocyte titration assay. Culture conditions, including lymphocyte concentrations, incubation periods and medium formulation, were established which produced linear or nearly linear responses over a range of cell concentrations. These conditions were established by testing lymphocytes from unimmunized cattle and from heifers infected with Brucella abortus with PHA and a B. abortus extract. Four cell concentrations in 2-fold increments were selected for measuring responses to PHA (3.125 X 10(3) to 2.5 X 10(4) cells/well) and to antigens (5.0 X 10(4) to 4.0 X 10(5) cells/well). The strength of response varied among animals and also over time for individual animals, but the titration assay allowed exponential proliferation to be distinguished from decline, which may have been due to overcrowding of microtiter wells, exhaustion of nutrients or induction of regulatory events. This assay provided a more reliable and discriminating method of evaluating lymphocyte proliferation responses than that achieved by single point assays. The displacement of the titration curves could be used to estimate the relative frequency of lymphocytes responding to antigens or mitogens.

  16. Titratable acidity of beverages influences salivary pH recovery.

    Science.gov (United States)

    Tenuta, Livia Maria Andaló; Fernández, Constanza Estefany; Brandão, Ana Carolina Siqueira; Cury, Jaime Aparecido

    2015-01-01

    A low pH and a high titratable acidity of juices and cola-based beverages are relevant factors that contribute to dental erosion, but the relative importance of these properties to maintain salivary pH at demineralizing levels for long periods of time after drinking is unknown. In this crossover study conducted in vivo, orange juice, a cola-based soft drink, and a 10% sucrose solution (negative control) were tested. These drinks differ in terms of their pH (3.5 ± 0.04, 2.5 ± 0.05, and 5.9 ± 0.1, respectively) and titratable acidity (3.17 ± 0.06, 0.57 ± 0.04 and buffering capacity kept 15 mL of each beverage in their mouth for 10 s, expectorated it, and their saliva was collected after 15, 30, 45, 60, 90, and 120 s. The salivary pH, determined using a mini pH electrode, returned to the baseline value at 30 s after expectoration of the cola-based soft drink, but only at 90 s after expectoration of the orange juice. The salivary pH increased to greater than 5.5 at 15 s after expectoration of the cola drink and at 30 s after expectoration of the orange juice. These findings suggest that the titratable acidity of a beverage influences salivary pH values after drinking acidic beverages more than the beverage pH.

  17. A rapid method for titration of ascovirus infectivity.

    Science.gov (United States)

    Han, Ningning; Chen, Zishu; Wan, Hu; Huang, Guohua; Li, Jianhong; Jin, Byung Rae

    2018-05-01

    Ascoviruses are a recently described family and the traditional plaque assay and end-point PCR assay have been used for their titration. However, these two methods are time-consuming and inaccurate to titrate ascoviruses. In the present study, a quick method for the determination of the titer of ascovirus stocks was developed based on ascovirus-induced apoptosis in infected insect cells. Briefly, cells infected with serial dilutions of virus (10 -2 -10 -10 ) for 24 h were stained with trypan blue. The stained cells were counted, and the percentage of nonviable cells was calculated. The stained cell rate was compared between virus-infected and control cells. The minimum-dilution group that had a significant difference compared with control and the maximum-dilution group that had no significant difference were selected and then compared each well of the two groups with the average stained cell rate of control. The well was marked as positive well if the stained cell rate was higher than the average stained cell rate of control wells; otherwise, the well was marked as negative wells. The percentage of positive wells were calculated according to the number of positive. Subsequently, the virus titer was calculated through the method of Reed and Muench. This novel method is rapid, simple, reproducible, accurate, and less material-consuming and eliminates the subjectivity of the other procedures for titrating ascoviruses. Copyright © 2018 Elsevier B.V. All rights reserved.

  18. The dynamics of slow manifolds

    NARCIS (Netherlands)

    Verhulst, F.; Bakri, T.

    2006-01-01

    Invited lecture at Konferensi Nasional Matematika XIII, Semarang, 24-27 juli, 2006; to be publ. in J. Indones. Math. Soc. (2007) After reviewing a number of results from geometric singular perturbation theory, we discuss several approaches to obtain periodic solutions in a slow manifold.

  19. The unappreciated slowness of conventional tourism

    Directory of Open Access Journals (Sweden)

    G.R. Larsen

    2016-05-01

    Full Text Available Most tourists are not consciously engaging in ‘slow travel’, but a number of travel behaviours displayed by conventional tourists can be interpreted as slow travel behaviour. Based on Danish tourists’ engagement with the distances they travel across to reach their holiday destination, this paper explores unintended slow travel behaviours displayed by these tourists. None of the tourists participating in this research were consciously doing ‘slow travel’, and yet some of their most valued holiday memories are linked to slow travel behaviours. Based on the analysis of these unintended slow travel behaviours, this paper will discuss the potential this insight might hold for promotion of slow travel. If unappreciated and unintentional slow travel behaviours could be utilised in the deliberate effort of encouraging more people to travel slow, ‘slow travel’ will be in a better position to become integrated into conventional travel behaviour.

  20. A new approach to flow-batch titration. A monosegmented flow titrator with coulometric reagent generation and potentiometric or biamperometric detection.

    Science.gov (United States)

    de Aquino, Emerson Vidal; Rohwedder, Jarbas José Rodrigues; Pasquini, Celio

    2006-11-01

    Monosegmented flow analysis (MSFA) has been used as a flow-batch system to produce a simple, robust, and mechanized titrator that enables true titrations to be performed without the use of standards. This paper also introduces the use of coulometry with monosegmented titration by proposing a versatile flow cell. Coulometric generation of the titrand is attractive for titrations performed in monosegmented systems, because the reagent can be added without increasing the volume of sample injected. Also, biamperomeric and potentiometric detection of titration end-points can increase the versatility of the monosegmented titrator. The cell integrates coulometric generation of the titrand with detection of end-point by potentiometry or biamperometry. The resulting titrator is a flow-batch system in which the liquid monosegment, constrained by the interfaces of the gaseous carrier stream, plays the role of a sample of known volume to be titrated. The system has been used for determination of ascorbic acid, by coulometric generation of I2 with biamperometric detection, and for determination of Fe(II), by coulometric generation of Ce(IV) with potentiometric detection of the end-point, both in feed supplements.

  1. Charge characteristics of humic and fulvic acids: comparative analysis by colloid titration and potentiometric titration with continuous pK-distribution function model.

    Science.gov (United States)

    Bratskaya, S; Golikov, A; Lutsenko, T; Nesterova, O; Dudarchik, V

    2008-09-01

    Charge characteristics of humic and fulvic acids of a different origin (inshore soils, peat, marine sediments, and soil (lysimetric) waters) were evaluated by means of two alternative methods - colloid titration and potentiometric titration. In order to elucidate possible limitations of the colloid titration as an express method of analysis of low content of humic substances we monitored changes in acid-base properties and charge densities of humic substances with soil depth, fractionation, and origin. We have shown that both factors - strength of acidic groups and molecular weight distribution in humic and fulvic acids - can affect the reliability of colloid titration. Due to deviations from 1:1 stoichiometry in interactions of humic substances with polymeric cationic titrant, the colloid titration can underestimate total acidity (charge density) of humic substances with domination of weak acidic functional groups (pK>6) and high content of the fractions with molecular weight below 1kDa.

  2. Logarithmically slow onset of synchronization

    Energy Technology Data Exchange (ETDEWEB)

    Benkoe, Gil; Jensen, Henrik Jeldtoft [Institute for Mathematical Sciences, Imperial College London, 53 Prince' s Gate, South Kensington Campus, SW7 2PG, London (United Kingdom)], E-mail: g.benkoe@imperial.ac.uk, E-mail: h.jensen@imperial.ac.uk

    2010-04-23

    The transient of a synchronizing system is investigated, considering synchronization as a relaxation phenomenon. The stepwise establishment of synchronization is studied in the system of dynamically coupled maps introduced by Ito and Kaneko (2001 Phys. Rev. Lett. 88 028701, 2003 Phys. Rev. E 67 046226), where the plasticity of dynamical couplings might be relevant in the context of neuroscience. Logarithmically slow dynamics in the transient of a fully deterministic dynamical system are shown to occur.

  3. Slow extraction at the SSC

    International Nuclear Information System (INIS)

    Colton, E.P.

    1985-01-01

    Resonant slow extraction at the SSC will permit fixed-target operation. Stochastic extraction appears to be a promising technique for achieving spill times of the order of 1000 s. However, systematic sextupole error fields in the SSC dipoles must be reduced a factor of twenty from the design values; otherwise the extraction process will be perturbed or suppressed. In addition, good regulation of the SSC power supplies is essential for smooth extraction over the spill period. 10 refs., 1 fig

  4. [Treatment of juvenile scoliosis: Increasing the lengthening interval with the growing rod technique should not necessarily compromise thoracic growth].

    Science.gov (United States)

    Pizones, J; Rodríguez-López, T; Zúñiga, L; Sánchez-Mariscal, F; Álvarez-González, P; Izquierdo, E

    2014-01-01

    Serial lengthening with growing rods is recommended every six months for the treatment of early onset scoliosis. The objective of this study was to evaluate the longitudinal growth of the thorax and control of the deformity in a series of patients with juvenile scoliosis when time intervals were increased between lengthenings. Retrospective study of eight patients. The following variables were measured: the Cobb angle, the apical vertebral translation, the coronal balance, thoracic T1-L1 length, thoracic T5-T12 kyphosis, the proximal junctional kyphosis (PJK) angle, and the lumbar lordosis. Complications were recorded. Five idiopathic and three syndromic scoliosis cases (mean age 9.4 ± 1.5 years) were evaluated. The initial surgery was followed by with an average of two distractions per patient. The mean time between distractions was 15.7 months. The final coronal main curve correction was 58%. Apical translation and coronal balance were improved and maintained after the surgeries. The thoracic (T1-L1) preoperative length was 20.8 cm, the postoperative length was 24.4 cm, and the final length was 26 cm. At the end of follow-up, the average growth of the thorax was 5.2 cm. The preoperative (T5-T12) kyphosis was 33.5°, and final 32.1°. The change in the PJK angle was 2.5° at the end of follow-up. Most complications were related to instrumentation. Two superficial wound infections were encountered. For less severe juvenile scoliosis patients treated with growing rods, spacing out lengthenings over more than a year can decrease the number of surgeries, while still controlling the deformity and allowing longitudinal thoracic growth. Copyright © 2014 SECOT. Published by Elsevier Espana. All rights reserved.

  5. [Insertion of gluteus maximus tendo-chilles lengthening with Z-shaped for the treatment of severe gluteal muscle contracture].

    Science.gov (United States)

    Chen, Huan-shi; Yang, Xiao-long

    2015-06-01

    To investigate clinical curative effects of gluteal muscle contracture release combined with insertion of gluteus maximus tendo-chilles lengthening with Z-shaped in treating severe gluteal muscles contracture. From 2006 May to 2011 May, 20 patients (35 sides) with severe gluteal muscle contracture were collected, including 12 males and 8 females, aged from 8 to 34 years old with an average of 13 years old; the courses of disease ranged from 3 to 21 years. All patients manifested abnormal gait at different degree, knees close together cannot squat,positive syndrome of Ober, positive test of alice leg. Gluteus contracture fascia release were performed firstly in operation, then insertion of tendo-chilles lengthening with Z-shaped were carried out. Preoperative and postoperative gait, and knee flexion hip extensor squat test, cross leg test, adduction and internal rotary activity of hip joint, stretch strength and motor ability after hip abduction were observed and compared. Twenty patients were followed up for 1 to 5 years. Gluteus maximus were released thoroughly, and snapping hip was disappeared, Ober syndrome were negative. There was significant differences in knee flexion hip extensor squat test, adduction and internal rotary activity of hip joint,stretch before and after operation (Pmuscle strength was protected,stretch strength and motor ability of hip joint were recovered well. Among them,31 cases got excellent results and 4 good. For severe gluteal muscles contracture,insertion of gluteus maximus tendo-chilles lengthening with Z-shaped performed after gluteus contracture fascia release could release gluteal muscle contracture to the greatest extent and obtain postoperative curative effect without resection of normal hip muscle fibers and destroy joint capsule.

  6. Knee Moment-Angle Characteristics and Semitendinosus Muscle Morphology in Children with Spastic Paresis Selected for Medial Hamstring Lengthening.

    Directory of Open Access Journals (Sweden)

    Helga Haberfehlner

    Full Text Available To increase knee range of motion and improve gait in children with spastic paresis (SP, the semitendinosus muscle (ST amongst other hamstring muscles is frequently lengthened by surgery, but with variable success. Little is known about how the pre-surgical mechanical and morphological characteristics of ST muscle differ between children with SP and typically developing children (TD. The aims of this study were to assess (1 how knee moment-angle characteristics and ST morphology in children with SP selected for medial hamstring lengthening differ from TD children, as well as (2 how knee moment-angle characteristics and ST morphology are related. In nine SP and nine TD children, passive knee moment-angle characteristics and morphology of ST (i.e. fascicle length, muscle belly length, tendon length, physiological cross-sectional area, and volume were assessed by hand-held dynamometry and freehand 3D ultrasound, respectively. At net knee flexion moments above 0.5 Nm, more flexed knee angles were found for SP compared to TD children. The measured knee angle range between 0 and 4 Nm was 30% smaller in children with SP. Muscle volume, physiological cross-sectional area, and fascicle length normalized to femur length were smaller in SP compared to TD children (62%, 48%, and 18%, respectively. Sixty percent of the variation in knee angles at 4 Nm net knee moment was explained by ST fascicle length. Altered knee moment-angle characteristics indicate an increased ST stiffness in SP children. Morphological observations indicate that in SP children planned for medial hamstring lengthening, the longitudinal and cross-sectional growth of ST muscle fibers is reduced. The reduced fascicle length can partly explain the increased ST stiffness and, hence, a more flexed knee joint in these SP children.

  7. Vangl2-regulated polarisation of second heart field-derived cells is required for outflow tract lengthening during cardiac development.

    Directory of Open Access Journals (Sweden)

    Simon A Ramsbottom

    2014-12-01

    Full Text Available Planar cell polarity (PCP is the mechanism by which cells orient themselves in the plane of an epithelium or during directed cell migration, and is regulated by a highly conserved signalling pathway. Mutations in the PCP gene Vangl2, as well as in other key components of the pathway, cause a spectrum of cardiac outflow tract defects. However, it is unclear why cells within the mesodermal heart tissue require PCP signalling. Using a new conditionally floxed allele we show that Vangl2 is required solely within the second heart field (SHF to direct normal outflow tract lengthening, a process that is required for septation and normal alignment of the aorta and pulmonary trunk with the ventricular chambers. Analysis of a range of markers of polarised epithelial tissues showed that in the normal heart, undifferentiated SHF cells move from the dorsal pericardial wall into the distal outflow tract where they acquire an epithelial phenotype, before moving proximally where they differentiate into cardiomyocytes. Thus there is a transition zone in the distal outflow tract where SHF cells become more polarised, turn off progenitor markers and start to differentiate to cardiomyocytes. Membrane-bound Vangl2 marks the proximal extent of this transition zone and in the absence of Vangl2, the SHF-derived cells are abnormally polarised and disorganised. The consequent thickening, rather than lengthening, of the outflow wall leads to a shortened outflow tract. Premature down regulation of the SHF-progenitor marker Isl1 in the mutants, and accompanied premature differentiation to cardiomyocytes, suggests that the organisation of the cells within the transition zone is important for maintaining the undifferentiated phenotype. Thus, Vangl2-regulated polarisation and subsequent acquisition of an epithelial phenotype is essential to lengthen the tubular outflow vessel, a process that is essential for on-going cardiac morphogenesis.

  8. Knee Moment-Angle Characteristics and Semitendinosus Muscle Morphology in Children with Spastic Paresis Selected for Medial Hamstring Lengthening.

    Science.gov (United States)

    Haberfehlner, Helga; Jaspers, Richard T; Rutz, Erich; Becher, Jules G; Harlaar, Jaap; van der Sluijs, Johannes A; Witbreuk, Melinda M; Romkes, Jacqueline; Freslier, Marie; Brunner, Reinald; Maas, Huub; Buizer, Annemieke I

    2016-01-01

    To increase knee range of motion and improve gait in children with spastic paresis (SP), the semitendinosus muscle (ST) amongst other hamstring muscles is frequently lengthened by surgery, but with variable success. Little is known about how the pre-surgical mechanical and morphological characteristics of ST muscle differ between children with SP and typically developing children (TD). The aims of this study were to assess (1) how knee moment-angle characteristics and ST morphology in children with SP selected for medial hamstring lengthening differ from TD children, as well as (2) how knee moment-angle characteristics and ST morphology are related. In nine SP and nine TD children, passive knee moment-angle characteristics and morphology of ST (i.e. fascicle length, muscle belly length, tendon length, physiological cross-sectional area, and volume) were assessed by hand-held dynamometry and freehand 3D ultrasound, respectively. At net knee flexion moments above 0.5 Nm, more flexed knee angles were found for SP compared to TD children. The measured knee angle range between 0 and 4 Nm was 30% smaller in children with SP. Muscle volume, physiological cross-sectional area, and fascicle length normalized to femur length were smaller in SP compared to TD children (62%, 48%, and 18%, respectively). Sixty percent of the variation in knee angles at 4 Nm net knee moment was explained by ST fascicle length. Altered knee moment-angle characteristics indicate an increased ST stiffness in SP children. Morphological observations indicate that in SP children planned for medial hamstring lengthening, the longitudinal and cross-sectional growth of ST muscle fibers is reduced. The reduced fascicle length can partly explain the increased ST stiffness and, hence, a more flexed knee joint in these SP children.

  9. Characterization of Sea Lettuce Surface Functional Groups by Potentiometric Titrations

    Science.gov (United States)

    Ebling, A. M.; Schijf, J.

    2008-12-01

    In pursuit of our ultimate goal to better understand the prodigious capacity of the marine macroalga Ulva lactuca (sea lettuce) for adsorbing a broad range of dissolved trace metals from seawater, we performed an initial characterization of its surface functional groups. Specifically, the number of distinct functional groups as well as their individual bulk concentrations and acid dissociation constants (pKas) were determined by potentiometric titrations in NaCl solutions of various ionic strengths (I = 0.01-5.0 M), under inert nitrogen atmosphere at 25°C. Depending on the ionic strength, Ulva samples were manually titrated down to pH 2 or 3 with 1 N HCl and then up to pH 10 with 1 N NaOH in steps of 0.1-0.2 units, continuously monitoring pH with a glass combination electrode. Titrations of a dehydrated Ulva standard reference material (BCR-279) were compared with fresh Ulva tissue cultured in our laboratory. A titration in filtered natural seawater was also compared with one in an NaCl solution of equal ionic strength. Equilibrium constants for the ionization of water in NaCl solutions as a function of ionic strength were obtained from the literature. Fits to the titration data ([H]T vs. pH) were performed with the FITEQL4.0 computer code using non-electrostatic 3-, 4-, and 5-site models, either by fixing ionic strength at its experimental value or by allowing it to be extrapolated to zero, while considering all functional group pKas and bulk concentrations as adjustable parameters. Since pKas and bulk concentrations were found to be strongly correlated, the latter were also fixed in some cases to further constrain the pKas. Whereas these calculations are currently ongoing, preliminary results point to three, possibly four, functional groups with pKas of about 4.1, 6.3, and 9.5 at I = 0. Bulk concentrations of the three groups are very similar, about 5-6×10-4 mol/g based on dry weight, which suggests that all are homogeneously distributed over the surface and

  10. Tendon lengthening and fascia release for healing and preventing diabetic foot ulcers: a systematic review and meta-analysis.

    Science.gov (United States)

    Dallimore, Sarah M; Kaminski, Michelle R

    2015-01-01

    Diabetic foot ulcers have a devastating impact on an individual's health-related quality of life and functional status. Additionally, diabetic foot ulcers impose a significant economic burden on our health care systems as a result of complications such as infection, hospitalisation and amputation. The current gold standard treatment for diabetic foot ulcers is total contact casting. However, the rate of ulcer recurrence is high, indicating the need for more effective long-term treatment options. Therefore, the aim of this study was to systematically identify, critique and evaluate all literature investigating the effectiveness of Achilles tendon lengthening, gastrocnemius recession and selective plantar fascia release in healing and preventing diabetic foot ulcers. Searches were conducted in MEDLINE, CINAHL, AMED, EMBASE and The Cochrane Library from the earliest available date to November 2014. Methodological quality of included studies was assessed using the Downs and Black checklist. Data from randomised-controlled trials were analysed using random effects meta-analysis. For all other studies, data were analysed descriptively. Eleven studies (614 participants) were included in the review, with a median sample size of 29 participants. Meta-analysis of two randomised-controlled trials found that there was no statistically significant difference between Achilles tendon lengthening or gastrocnemius recession and total contact casting for time to healing of diabetic foot ulcers (mean difference, MD, 8.22 days; 95 % CI, -18.99 to 35.43; P = 0.55; I (2)  = 34 %) and the rate of ulcers healed (risk ratio, RR, 1.06; 95 % CI, 0.94 to 1.20; P = 0.34; I (2)  = 41 %). The rate of ulcer recurrence was significantly lower following Achilles tendon lengthening or gastrocnemius recession than total contact casting (RR, 0.45; 95 % CI, 0.28 to 0.72; P diabetic foot ulcers. The rate of ulcer recurrence was lower following Achilles tendon lengthening or

  11. Digital Smile Design concept delineates the final potential result of crown lengthening and porcelain veneers to correct a gummy smile.

    Science.gov (United States)

    Trushkowsky, Richard; Arias, David Montalvo; David, Steven

    Prior to initiating any treatment, it is necessary to visualize the desired outcomes. It then becomes possible to formulate the steps required to achieve this result. Digital Smile Design (DSD) utilizes patient input and information gathered through diagnostic procedures to create an esthetic treatment scheme. In the case presented here, the NYUCD Esthetic Evaluation Form, intraoral and extraoral photographs, mounted diagnostic casts, physical examination, and radiographs were the diagnostic modalities. The gathered information served as a starting point for a wax-up and intraoral mock-up. This case report demonstrates how the DSD served as a template for crown lengthening procedures and design of the final porcelain veneer restorations.

  12. Titratable acidity of beverages influences salivary pH recovery

    Directory of Open Access Journals (Sweden)

    Livia Maria Andaló TENUTA

    2015-01-01

    Full Text Available A low pH and a high titratable acidity of juices and cola-based beverages are relevant factors that contribute to dental erosion, but the relative importance of these properties to maintain salivary pH at demineralizing levels for long periods of time after drinking is unknown. In this crossover study conducted in vivo, orange juice, a cola-based soft drink, and a 10% sucrose solution (negative control were tested. These drinks differ in terms of their pH (3.5 ± 0.04, 2.5 ± 0.05, and 5.9 ± 0.1, respectively and titratable acidity (3.17 ± 0.06, 0.57 ± 0.04 and < 0.005 mmols OH- to reach pH 5.5, respectively. Eight volunteers with a normal salivary flow rate and buffering capacity kept 15 mL of each beverage in their mouth for 10 s, expectorated it, and their saliva was collected after 15, 30, 45, 60, 90, and 120 s. The salivary pH, determined using a mini pH electrode, returned to the baseline value at 30 s after expectoration of the cola-based soft drink, but only at 90 s after expectoration of the orange juice. The salivary pH increased to greater than 5.5 at 15 s after expectoration of the cola drink and at 30 s after expectoration of the orange juice. These findings suggest that the titratable acidity of a beverage influences salivary pH values after drinking acidic beverages more than the beverage pH.

  13. A titration model for evaluating calcium hydroxide removal techniques

    Directory of Open Access Journals (Sweden)

    Mark PHILLIPS

    2015-02-01

    Full Text Available Objective Calcium hydroxide (Ca(OH2 has been used in endodontics as an intracanal medicament due to its antimicrobial effects and its ability to inactivate bacterial endotoxin. The inability to totally remove this intracanal medicament from the root canal system, however, may interfere with the setting of eugenol-based sealers or inhibit bonding of resin to dentin, thus presenting clinical challenges with endodontic treatment. This study used a chemical titration method to measure residual Ca(OH2 left after different endodontic irrigation methods. Material and Methods Eighty-six human canine roots were prepared for obturation. Thirty teeth were filled with known but different amounts of Ca(OH2 for 7 days, which were dissolved out and titrated to quantitate the residual Ca(OH2 recovered from each root to produce a standard curve. Forty-eight of the remaining teeth were filled with equal amounts of Ca(OH2 followed by gross Ca(OH2 removal using hand files and randomized treatment of either: 1 Syringe irrigation; 2 Syringe irrigation with use of an apical file; 3 Syringe irrigation with added 30 s of passive ultrasonic irrigation (PUI, or 4 Syringe irrigation with apical file and PUI (n=12/group. Residual Ca(OH2 was dissolved with glycerin and titrated to measure residual Ca(OH2 left in the root. Results No method completely removed all residual Ca(OH2. The addition of 30 s PUI with or without apical file use removed Ca(OH2 significantly better than irrigation alone. Conclusions This technique allowed quantification of residual Ca(OH2. The use of PUI (with or without apical file resulted in significantly lower Ca(OH2 residue compared to irrigation alone.

  14. Modelling of acid-base titration curves of mineral assemblages

    Directory of Open Access Journals (Sweden)

    Stamberg Karel

    2016-01-01

    Full Text Available The modelling of acid-base titration curves of mineral assemblages was studied with respect to basic parameters of their surface sites to be obtained. The known modelling approaches, component additivity (CA and generalized composite (GC, and three types of different assemblages (fucoidic sandstones, sedimentary rock-clay and bentonite-magnetite samples were used. In contrary to GC-approach, application of which was without difficulties, the problem of CA-one consisted in the credibility and accessibility of the parameters characterizing the individual mineralogical components.

  15. Sequential hypothesis of sleep function. V. Lengthening of post-trial SS episodes in reminiscent rats.

    Science.gov (United States)

    Ambrosini, M V; Mariucci, G; Bruschelli, G; Colarieti, L; Giuditta, A

    1995-11-01

    Rats failing to learn a two-way active avoidance task during the training session were tested for performance the following day. One group of rats maintained its low level of avoidances (non improving or NI rats), while the remaining rats dramatically improved their avoidance score (improving or I rats). EEG recording during the posttrial period demonstrated significant variations in the sleep structure of I rats, in comparison with NI rats. The main change consisted in an increase in the average duration of the episodes of slow wave sleep followed by wakefulness or by paradoxical sleep. These variations occurred in the third hour of the posttrial period, while an increment in the amount of PS was observed in the sixth hour. In I rats, but not in NI rats, comparable variations emerged from the comparison of baseline sleep (determined the day before training) with posttrial sleep. The data are in agreement with the main postulate of the sequential hypothesis of sleep function which attributes a primary role to slow wave sleep in the processing of newly acquired memories.

  16. Free Software Development. 3. Numerical Description of Soft Acid with Soft Base Titration

    Directory of Open Access Journals (Sweden)

    Lorentz JÄNTSCHI

    2002-12-01

    Full Text Available The analytical methods of qualitative and quantitative determination of ions in solutions are very flexible to automation. The present work is focus on modeling the process of titration and presents a numerical simulation of acid-base titration. A PHP program to compute all iterations in titration process that solves a 3th rank equation to find value of pH for was built and is available through http internet protocol at the address: http://vl.academicdirect.org/molecular_dynamics/ab_titrations/v1.1/ The method allows expressing the value of pH in any point of titration process and permits to observe the equivalence point of titration.

  17. Comparison of VFA titration procedures used for monitoring the biogas process

    DEFF Research Database (Denmark)

    Lützhøft, Hans-Christian Holten; Boe, Kanokwan; Fang, Cheng

    2014-01-01

    titration procedures. Currently, no standardized procedure is used and it is therefore difficult to compare the performance among plants. The aim of this study was to evaluate four titration procedures (for determination of VFA-levels of digested manure samples) and compare results with gas chromatographic...... (GC) analysis. Two of the procedures are commonly used in biogas plants and two are discussed in literature. The results showed that the optimal titration results were obtained when 40mL of four times diluted digested manure was gently stirred (200rpm). Results from samples with different VFA...... concentrations (1-11g/L) showed linear correlation between titration results and GC measurements. However, determination of VFA by titration generally overestimated the VFA contents compared with GC measurements when samples had low VFA concentrations, i.e. around 1g/L. The accuracy of titration increased when...

  18. [A double antibody sandwich ELISA based assay for titration of severe fever with thrombocytopenia syndrome virus].

    Science.gov (United States)

    Liu, Lin; Zhang, Quan-Fu; Li, Chuan; Li, Jian-Dong; Jiang, Xiao-Lin; Zhang, Fu-Shun; Wu, Wei; Liang, Mi-Fang; Li, De-Xin

    2013-06-01

    To develop an assay for titration of severe fever with thrombocytopenia syndrome virus (SFTSV) based on double antibody sandwich ELISA. A double antibody sandwich ELISA was developed for detection of SFTSV based on SFTSV nucleocapsid (N) protein specific poly- and monoclonal antibodies, procedures were optimized and evaluated. This ELISA based titration assay was compared with fluorescence assasy and plaque assay based titration method. The results suggested that the titers obtained by ELISA based method are consistent with those obtained by IFA based method (R = 0.999) and the plaque assay titration method (R = 0.949). The novel ELISA based titration method with high sensitivity and specificity is easy to manage and perform, and can overcome the subjectivity associated with result determination of the fluorescence assay and plaque assay based methods. The novel ELISA based titration method can also be applied to high throughput detection.

  19. SPECIAL CONSIDERATIONS REGARDING WARFARIN DOSE TITRATION IN PATIENTS WITH ATRIAL FIBRILLATION DEPENDING ON CLINICAL FACTORS

    OpenAIRE

    E. L. Artanova; E. V. Saleeva; I. M. Sokolov; Y. G. Shvarts

    2011-01-01

    Aim. To study the relations of clinical characteristics and individual warfarin dose titration in patients with atrial fibrillation. Material and methods. Period of warfarin dose titration was analyzed in 68 patients with atrial fibrillation due to ischemic heart disease. Adjusted warfarin dose in milligram, duration of dose titration in days and maximal international normalized ratio (INR) were taken into account. Sex, age, history of myocardial infarction and stroke, concomitant diseases, a...

  20. Potentiometric titration of molybdenum (6) with a cathode-polarized solid electrode

    International Nuclear Information System (INIS)

    Boeva, L.V.; Kimstach, V.A.; Bagdasarov, K.N.

    1980-01-01

    The possibility has been studied of using solid electrodes for potentiometric precipitation titration of molybdenum (6). A cathode-polarized electrode, electrochemically covered with a molybdenum blue layer, can be used as indicator electrode. The best results were obtained during deposition of molybdenum blue on a tungsten electrode. The mechanism of electrode work during titration has been investigated. A procedure has been developed of titration of molybdenum (6) in acid solutions using hydroxylamine N-aryl derivatives as titrants

  1. Thermometric Titration for Rapid Determination of Trace Water in Jet Fuel

    OpenAIRE

    Jian-Qiang Hu; Jian-Jian Zhang; Shi-Zhao Yang; Yong-Liang Xin; Li Guo; Ting Yao

    2017-01-01

    Water content in jet fuels is detected by thermometric titration (TMT), and the optimal detected system is 2,2-dimethoxypropane as titrant, cyclohexane and isopropanol as titration solvents, and methanesulfonic acid as catalyst in this method. The amounts of oil, concentration and delivery rate of titrant, volumes, and the reliability and accuracy of thermometric titration were emphasized. The results show that the accuracy, validity, and reliability of TMT are excellent by different indicate...

  2. Simple Modification of Karl-Fischer Titration Method for Determination of Water Content in Colored Samples

    OpenAIRE

    Eva Tavčar; Erika Turk; Samo Kreft

    2012-01-01

    The most commonly used technique for water content determination is Karl-Fischer titration with electrometric detection, requiring specialized equipment. When appropriate equipment is not available, the method can be performed through visual detection of a titration endpoint, which does not enable an analysis of colored samples. Here, we developed a method with spectrophotometric detection of a titration endpoint, appropriate for moisture determination of colored samples. The reaction takes p...

  3. Fast Proton Titration Scheme for Multiscale Modeling of Protein Solutions.

    Science.gov (United States)

    Teixeira, Andre Azevedo Reis; Lund, Mikael; da Silva, Fernando Luís Barroso

    2010-10-12

    Proton exchange between titratable amino acid residues and the surrounding solution gives rise to exciting electric processes in proteins. We present a proton titration scheme for studying acid-base equilibria in Metropolis Monte Carlo simulations where salt is treated at the Debye-Hückel level. The method, rooted in the Kirkwood model of impenetrable spheres, is applied on the three milk proteins α-lactalbumin, β-lactoglobulin, and lactoferrin, for which we investigate the net-charge, molecular dipole moment, and charge capacitance. Over a wide range of pH and salt conditions, excellent agreement is found with more elaborate simulations where salt is explicitly included. The implicit salt scheme is orders of magnitude faster than the explicit analog and allows for transparent interpretation of physical mechanisms. It is shown how the method can be expanded to multiscale modeling of aqueous salt solutions of many biomolecules with nonstatic charge distributions. Important examples are protein-protein aggregation, protein-polyelectrolyte complexation, and protein-membrane association.

  4. Semi-automated potentiometric titration method for uranium characterization

    Energy Technology Data Exchange (ETDEWEB)

    Cristiano, B.F.G., E-mail: barbara@ird.gov.br [Comissao Nacional de Energia Nuclear (CNEN), Instituto de Radioprotecao e Dosimetria (IRD), Avenida Salvador Allende s/n Recreio dos Bandeirantes, PO Box 37750, Rio de Janeiro, 22780-160 RJ (Brazil); Delgado, J.U.; Silva, J.W.S. da; Barros, P.D. de; Araujo, R.M.S. de [Comissao Nacional de Energia Nuclear (CNEN), Instituto de Radioprotecao e Dosimetria (IRD), Avenida Salvador Allende s/n Recreio dos Bandeirantes, PO Box 37750, Rio de Janeiro, 22780-160 RJ (Brazil); Lopes, R.T. [Programa de Engenharia Nuclear (PEN/COPPE), Universidade Federal do Rio de Janeiro (UFRJ), Ilha do Fundao, PO Box 68509, Rio de Janeiro, 21945-970 RJ (Brazil)

    2012-07-15

    The manual version of the potentiometric titration method has been used for certification and characterization of uranium compounds. In order to reduce the analysis time and the influence of the analyst, a semi-automatic version of the method was developed in the Brazilian Nuclear Energy Commission. The method was applied with traceability assured by using a potassium dichromate primary standard. The combined standard uncertainty in determining the total concentration of uranium was around 0.01%, which is suitable for uranium characterization. - Highlights: Black-Right-Pointing-Pointer We developed a semi-automatic version of potentiometric titration method. Black-Right-Pointing-Pointer The method is used for certification and characterization of uranium compounds. Black-Right-Pointing-Pointer The traceability of the method was assured by a K{sub 2}Cr{sub 2}O{sub 7} primary standard. Black-Right-Pointing-Pointer The results of U{sub 3}O{sub 8} reference material analyzed was consistent with certified value. Black-Right-Pointing-Pointer The uncertainty obtained, near 0.01%, is useful for characterization purposes.

  5. Common Standards of Basal Insulin Titration in T2DM

    Science.gov (United States)

    Arnolds, Sabine; Heise, Tim; Flacke, Frank; Sieber, Jochen

    2013-01-01

    Type 2 diabetes mellitus has become a worldwide major health problem, and the number of people affected is steadily increasing. Thus, not all patients suffering from the disease can be treated by specialized diabetes centers or outpatient clinics, but by primary care physicians. The latter, however, might have time constraints and have to deal with many kinds of diseases or with multimorbid patients, so their focus is not so much on lowering high blood glucose values. Thus, the physicians, as well as the patients themselves, are often reluctant to initiate and adjust insulin therapy, although basal insulin therapy is considered the appropriate strategy after oral antidiabetic drug failure, according to the latest international guidelines. A substantial number of clinical studies have shown that insulin initiation and optimization can be managed successfully by using titration algorithms—even in cases where patients themselves are the drivers of insulin titration. Nevertheless, tools and strategies are needed to facilitate this process in the daily life of both primary health care professionals and patients with diabetes. PMID:23759411

  6. Radiometric titration of thallium(III) with EDTA

    International Nuclear Information System (INIS)

    Rao, V.R.S.; Pulla Rao, Ch.; Tataiah, G.

    1978-01-01

    Radioactive solutions containing very small amounts of thallium(III) can be determined by radiometric titration using ammonia as hydrolysing agent. Aqueous solution of thallium(I) (both inactive and radioactive) is treated with bromine water till the appearance of the brown colour of bromine, and the solution is warmed to 80 deg C to expel the excess bromine. By this procedure all thallium(I) is quantitatively oxidised to thallium(III). An aqueous solution of ammonia is added to precipitate thallium(III) as thallic oxide. It is then filtered, washed with water to free it from bromide and then dissolved in 2N HCl and the solution is then standardised. 2 ml of this solution is transferred to a 20 ml volumetric flask, 1 ml of radioactive thallium(III) solution to be standardised is added as well as incremental amounts of EDTA solution and mixed thoroughly. Uncomplexed thallium(III) is then precipitated by the addition of an ammonia solution and diluted to 20 ml. Required amount of this mixture is centrifuged. The beta activity of the supernatant aliquot is measured using a GM counter. Quantitative determination of Tl(III) in the range of 1-10 μM can be carried out. The interference of cations such as Au(III), iron(III), Ga(III) can be eliminated by pretreatment of the Tl(III) solution before carrying out radiometric titration. The results obtained are reproducible and accurate to +-3%. (T.I.)

  7. Sciatic Nerve Palsy following Total Hip Replacement: Are Patients Personal Characteristics More Important than Limb Lengthening? A Systematic Review

    Directory of Open Access Journals (Sweden)

    Marcello De Fine

    2017-01-01

    Full Text Available Sciatic nerve palsies are rare but potentially devastating complications, accounting for more than 90% of neurologic injuries following total hip replacement. A systematic literature screening was carried out searching papers evaluating an exclusive population of postarthroplasty sciatic nerve palsies to ascertain (1 the influence of limb lengthening itself on sciatic nerve palsy, (2 the most important risk factors, (3 the long-term prognosis, and (4 the outcomes of different treatments. Fourteen manuscripts were finally included. The wide prevalence of retrospective case series decreased the global methodological quality of the retrieved papers. A hazardous lengthening threshold cannot be surely identified. Developmental dysplasia of the hip and previous hip surgeries are the most frequently recognized risk factors. Rate of full nerve function restoration approximates two-thirds of the cases, independently of the extent of initial neural damage. Poor evidences are available about the best treatment strategy. Well-structured multicentric prospective comparative studies are needed to substantiate or contrast the finding of this review. Anyway, since the onset of palsies is probably due to a combination of individual factors, risk of nerve damage and potential for nerve recovery should be evaluated on an individual basis.

  8. Hip flexion deformity improves without psoas-lengthening after surgical correction of fixed knee flexion deformity in spastic diplegia.

    Science.gov (United States)

    Rutz, Erich; Gaston, Mark S; Tirosh, Oren; Brunner, Reinald

    2012-01-01

    It is unclear if psoas lengthening surgery is required in the treatment of patients with cerebral palsy (CP) with hip flexion deformity and previous studies show equivocal results with regard to functional outcome. This study retrospectively assessed 12 patients with a diagnosis of spastic diplegia who underwent single event multilevel surgery in order to correct deformities in the sagittal plane distal to the hip. Both clinical and instrument gait analysis results were recorded preoperatively, at one year (short term) and at five years (mid term) postoperatively. Clinically measured hip and knee movement improved at both short and mid term follow up. Correlations of clinically measured maximum hip and knee extension were significant at all three time points. Angles at terminal stance/toe off for hip and knee from kinematic data also showed significant correlations at all three time points. Our study demonstrates that the hip flexion deformities encountered in these patients will improve spontaneously when the distal fixed knee flexion deformity is surgically corrected. Therefore correction at the knee allows the ground reaction force to assume a more normal position resulting in correction at the hip over time. This then removes the need for surgery at the hip level. This fact is especially important when applied to psoas lengthening as this procedure can cause significant reduction in propulsion power.

  9. The CUORE slow monitoring systems

    Science.gov (United States)

    Gladstone, L.; Biare, D.; Cappelli, L.; Cushman, J. S.; Del Corso, F.; Fujikawa, B. K.; Hickerson, K. P.; Moggi, N.; Pagliarone, C. E.; Schmidt, B.; Wagaarachchi, S. L.; Welliver, B.; Winslow, L. A.

    2017-09-01

    CUORE is a cryogenic experiment searching primarily for neutrinoless double decay in 130Te. It will begin data-taking operations in 2016. To monitor the cryostat and detector during commissioning and data taking, we have designed and developed Slow Monitoring systems. In addition to real-time systems using LabVIEW, we have an alarm, analysis, and archiving website that uses MongoDB, AngularJS, and Bootstrap software. These modern, state of the art software packages make the monitoring system transparent, easily maintainable, and accessible on many platforms including mobile devices.

  10. Corpuscular slow-roll inflation

    Science.gov (United States)

    Casadio, Roberto; Giugno, Andrea; Giusti, Andrea

    2018-01-01

    We show that a corpuscular description of gravity can lead to an inflationary scenario similar to Starobinsky's model without requiring the introduction of the inflaton field. All relevant properties are determined by the number of gravitons in the cosmological condensate or, equivalently, by their Compton length. In particular, the relation between the Hubble parameter H and its time derivative H ˙ required by cosmic microwave background observations at the end of inflation, as well as the (minimum) initial value of the slow-roll parameter, are naturally obtained from the Compton size of the condensate.

  11. Blowup for flat slow manifolds

    DEFF Research Database (Denmark)

    Kristiansen, Kristian Uldall

    2017-01-01

    In this paper, we present a way of extending the blowup method, in the formulation of Krupa and Szmolyan, to flat slow manifolds that lose hyperbolicity beyond any algebraic order. Although these manifolds have infinite co-dimensions, they do appear naturally in certain settings; for example, in (a......) the regularization of piecewise smooth systems by tanh, (b) a particular aircraft landing dynamics model, and finally (c) in a model of earthquake faulting. We demonstrate the approach using a simple model system and the examples (a) and (b)....

  12. Blowup for flat slow manifolds

    Science.gov (United States)

    Kristiansen, K. U.

    2017-05-01

    In this paper, we present a way of extending the blowup method, in the formulation of Krupa and Szmolyan, to flat slow manifolds that lose hyperbolicity beyond any algebraic order. Although these manifolds have infinite co-dimensions, they do appear naturally in certain settings; for example, in (a) the regularization of piecewise smooth systems by \\tanh , (b) a particular aircraft landing dynamics model, and finally (c) in a model of earthquake faulting. We demonstrate the approach using a simple model system and the examples (a) and (b).

  13. Slow electrons kill the ozone

    International Nuclear Information System (INIS)

    Maerk, T.

    2001-01-01

    A new method and apparatus (Trochoidal electron monochromator) to study the interactions of electrons with atoms, molecules and clusters was developed. Two applications are briefly reported: a) the ozone destruction in the atmosphere is caused by different reasons, a new mechanism is proposed, that slow thermal electrons are self added to the ozone molecule (O 3 ) with a high frequency, then O 3 is destroyed ( O 3 + e - → O - + O 2 ); b) another application is the study of the binding energy of the football molecule C60. (nevyjel)

  14. Ruthenium determination in new composite materials by coulometric titration with generated iron(2)

    International Nuclear Information System (INIS)

    Butakova, N.A.; Oganesyan, L.B.

    1983-01-01

    A coulometric technique is developed for ruthenium (4) titration with generated iron (2) in a mixture of hydrochloric-, sulfuric- and phosphoric acids with potentiometric and biammetric indication of the final titration point. Bi (3), Pd (2), Nb (5), Pt (4) Pb (2), Rh (3) do not interfere with the titration. Together with Ru (4) titrated are Ir (4), V (5), Au (3). The method is applied to analyze commercial samples of ruthenium dioxides, lead- and bismuth ruthenites, ruthenium pentafluorides containing 30-80% of ruthenium. The Ssub(r) values do not exceed 0.002

  15. The role of titration schedule of topiramate for the development of depression in patients with epilepsy.

    Science.gov (United States)

    Mula, Marco; Hesdorffer, Dale C; Trimble, Michael; Sander, Josemir W

    2009-05-01

    To determine whether a fast titration schedule of topiramate (TPM) has different effects on the occurrence of depression, in relation to other risk factors for TPM-induced depression, including history of depression (HxDEP), febrile seizures (FS), and hippocampal sclerosis (HS). Using data from a large case registry of patients prescribed TPM, two models were constructed: Model 1 examined the independent effect of rapid TPM titration after separate adjustment for FS, HxDEP, and HS. Model 2 examined effect of the cooccurrence of rapid titration on the development of depression with each of these risk factors. A total of 423 patients were included (51.8% females), mean age (SD) 35.5 (11.8) years, mean duration of epilepsy of 22.2 (11.5) years. Forty-four patients (10.4%) developed depression during TPM therapy. A rapid TPM titration was associated with 5-fold increased risk of depression that increased to 12.7-fold in the presence of both FS and rapid TPM titration, 23.3-fold in the presence of both HxDEP and rapid TPM titration, and 7.6-fold in the presence of both HS and rapid TPM titration schedule. Our study suggests that a rapid titration schedule is associated with an increased risk of developing depression during TPM therapy. HxDEP and FS are major contraindications to the use of a rapid titration, with a 23.3-fold and 12.7 fold increased risk, respectively.

  16. Method for linearizing the potentiometric curves of precipitation titration in nonaqueous and aqueous-organic solutions

    International Nuclear Information System (INIS)

    Bykova, L.N.; Chesnokova, O.Ya.; Orlova, M.V.

    1995-01-01

    The method for linearizing the potentiometric curves of precipitation titration is studied for its application in the determination of halide ions (Cl - , Br - , I - ) in dimethylacetamide, dimethylformamide, in which titration is complicated by additional equilibrium processes. It is found that the method of linearization permits the determination of the titrant volume at the end point of titration to high accuracy in the case of titration curves without a potential jump in the proximity of the equivalent point (5 x 10 -5 M). 3 refs., 2 figs., 3 tabs

  17. Application of »Mass Titration« to Determination of Surface Charge of Metal Oxides

    OpenAIRE

    1998-01-01

    The mass titration method, used for the point of zero charge determination, was extended to the measurement of the surface charge density. The results agree with the common method, which is the acid-base titration of the colloidal suspension. The advantage of mass titration is that one does not need to perform blank titration, instead one simply adds metal oxide powder to the electrolyte aqueous solution of known pH. To cover the pH range above and below the point of zero charge, two experime...

  18. [Comparison of different continuous positive airway pressure titration methods for obstructive sleep apnea hypopnea syndrome].

    Science.gov (United States)

    Li, Jingjing; Ye, Jingying; Zhang, Peng; Kang, Dan; Cao, Xin; Zhang, Yuhuan; Ding, Xiu; Zheng, Li; Li, Hongguang; Bian, Qiuli

    2014-10-01

    To explore whether there were differences between the results of automatic titration and the results of manual titration for positive airway pressure treatment in patients with obstructive sleep apnea hypopnea syndrome (OSAHS) and its influencing factors, the results might provide a theoretical basis for the rational use of two pressure titration methods. Sixty one patients with OSAHS were included in this study. All patients underwent a manual titration and an automatic titration within one week. The clinical informations, polysomnography data, and the results of both two titration of all patients were obtained for analysis. The overall apnea/hypopnea index was (63.1 ± 17.7)/h, with a range of 14.9/h to 110.4/h. The treatment pressure of manual titration was (8.4 ± 2.1) cmH(2)O, which was significantly lower than the treatment pressure of automatic titration, (11.5 ± 2.7) cmH(2)O (t = -9.797, P titration and manual titration), it was found that the pressure of automatic titration was significantly higher in patients with a ΔP > 3 cmH(2)O than in patients with a ΔP ≤ 3 cmH(2)O, which was (13.3 ± 2.3) cmH(2)O vs (10.0 ± 2.0) cmH(2)O (t = -6.159, P titration between these two groups, which was (8.6 ± 2.4) cmH(2)O vs (8.3 ± 2.0)cmH(2)O (P > 0.05). There was no significant difference in age, body mass index, neck circumference, abdomen circumference, apnea hypopnea index, and arterial oxygen saturation between these two groups. The treatment pressure of automatic titration is usually higher than that of manual titration. For patients with a high treatment pressure which is derived from automatic titration, a suggestion about manual titration could be given to decrease the potential treatment pressure of continuous positive airway pressure, which may be helpful in improving the comfortableness and the compliance of this treatment.

  19. Connecting slow earthquakes to huge earthquakes

    OpenAIRE

    Obara, Kazushige; Kato, Aitaro

    2016-01-01

    Slow earthquakes are characterized by a wide spectrum of fault slip behaviors and seismic radiation patterns that differ from those of traditional earthquakes. However, slow earthquakes and huge megathrust earthquakes can have common slip mechanisms and are located in neighboring regions of the seismogenic zone. The frequent occurrence of slow earthquakes may help to reveal the physics underlying megathrust events as useful analogs. Slow earthquakes may function as stress meters because of th...

  20. Integrated Photonics Enabled by Slow Light

    DEFF Research Database (Denmark)

    Mørk, Jesper; Chen, Yuntian; Ek, Sara

    2012-01-01

    In this talk we will discuss the physics of slow light in semiconductor materials and in particular the possibilities offered for integrated photonics. This includes ultra-compact slow light enabled optical amplifiers, lasers and pulse sources.......In this talk we will discuss the physics of slow light in semiconductor materials and in particular the possibilities offered for integrated photonics. This includes ultra-compact slow light enabled optical amplifiers, lasers and pulse sources....

  1. Don't Forget the Slow Learner.

    Science.gov (United States)

    Watson, Daniel L.; Rangel, Lyle

    1989-01-01

    Advocates cooperative learning as an effective tool for reaching slow learners, by bridging the gaps between the learning styles of slow learners and the teaching requirements of the classroom, resulting in improved academic performance for both slow learners and high achievers. (SR)

  2. The role of variable muscle adaptation to limb lengthening in the development of joint contractures: an experimental study in the goat.

    Science.gov (United States)

    Makarov, Marina; Birch, John; Samchukov, Mikhail

    2009-03-01

    Muscle stiffness and joint contractures are currently regarded as the most common complications of limb lengthening. To better understand the mechanisms of joint contractures, architectural changes of all involved muscles were analyzed in 9 goats after 20% tibial lengthening with standard distraction protocol.All 13 muscles of the goat's tibia were found to be organized into an anterior compartment with 2 longitudinal and 4 pennate muscles and a posterior compartment with 1 longitudinal and 6 pennate muscles. Longitudinal muscles showed better compliance to distraction than pinnate muscles. Although muscle-to-bone lengthening ratio ranged widely (0-1.2), most of the muscles and especially those located in the posterior compartment showed much less lengthening than the bone. Muscular portions of the muscles lengthened more substantially (average, 17%) than their associated tendons (average, 7%). Muscle fiber length changes varied greatly between muscles (range, 0%-88%). Normalization of muscle fiber length revealed considerable elongation of anterior muscles fibers (25%) that was associated with an addition of new sarcomeres in series. Fiber length increase of all posterior muscles but one occurred by stretching of existing sarcomeres, with little addition or even dissolution of sarcomeres in series. This correlated with muscle mass changes showing significant muscle atrophy in the posterior compartment and better mass preservation in the anterior compartment.The study revealed striking difference in response to limb lengthening between individual muscles and muscles from antagonistic compartments in particular. Poor sarcomerogenesis in the posterior muscles leading to their insufficient length increase seems to play major role in the development of joint contractures.

  3. Titration curves: a useful instrument for assessing the buffer systems of acidic mining waters.

    Science.gov (United States)

    Totsche, Oliver; Fyson, Andrew; Kalin, Margarete; Steinberg, Christian E W

    2006-07-01

    The acidification of mine waters is generally caused by metal sulfide oxidation, related to mining activities. These waters are characterized by low pH and high acidity due to strong buffering systems. The standard acidity parameter, the Base Neutralization Capacity (BNC), is determined by endpoint titration, and reflects a cumulative parameter of both hydrogen ions and all buffering systems, but does not give information on the individual buffer systems. We demonstrate that a detailed interpretation of titration curves can provide information about the strength of the buffering systems. The buffering systems are of importance for environmental studies and treatment of acidic mining waters. Titrations were carried out by means of an automatic titrator using acidic mining waters from Germany and Canada. The curves were interpreted, compared with each other, to endpoint titration results and to elemental concentrations contained therein. The titration curves were highly reproducible, and contained information about the strength of the buffer systems present. Interpretations are given, and the classification and comparison of acidic mining waters, by the nature and strength of their buffering systems derived from titration curves are discussed. The BNC-values calculated from the curves were more precise than the ones determined by the standard endpoint titration method. Due to the complex buffer mechanisms in acidic mining waters, the calculation of major metal concentrations from the shape of the titration curve resulted in estimates, which should not be confused with precise elemental analysis results. Titration curves provide an inexpensive, valuable and versatile tool, by which to obtain sophisticated information of the acidity in acidic water. The information about the strength of the present buffer systems can help to understand and document the complex nature of acidic mining water buffer systems. Finally, the interpretation of titration curves could help to

  4. Insights into optimal basal insulin titration in type 2 diabetes: Results of a quantitative survey.

    Science.gov (United States)

    Berard, Lori; Bonnemaire, Mireille; Mical, Marie; Edelman, Steve

    2018-02-01

    Basal insulin (BI) treatment initiation and dose titration in type 2 diabetes (T2DM) are often delayed. Such "clinical inertia" results in poor glycaemic control and high risk of long-term complications. This survey aimed to determine healthcare professional (HCP) and patient attitudes to BI initiation and titration. An online survey (July-August 2015) including HCPs and patients with T2DM in the USA, France and Germany. Patients were ≥18 years old and had been on BI for 6 to 36 months, or discontinued BI within the previous 12 months. Participants comprised 386 HCPs and 318 people with T2DM. While >75% of HCPs reported discussing titration at the initiation visit, only 16% to 28% of patients remembered such discussions, many (32%-42%) were unaware of the need to titrate BI, and only 28% to 39% recalled mention of the time needed to reach glycaemic goals. Most HCPs and patients agreed that more effective support tools to assist BI initiation/titration are needed; patients indicated that provision of such tools would increase confidence in self-titration. HCPs identified fear of hypoglycaemia, failure to titrate in the absence of symptoms, and low patient motivation as important titration barriers. In contrast, patients identified weight gain, the perception that titration meant worsening disease, frustration over the time to reach HbA1c goals and fear of hypoglycaemia as major factors. A disconnect exists between HCP- and patient-perceived barriers to effective BI titration. To optimize titration, strategies should be targeted to improve HCP-patient communication, and provide support and educational tools. © 2017 The Authors. Diabetes, Obesity and Metabolism published by John Wiley & Sons Ltd.

  5. All Internal Segmental Bone Transport and Optional Lengthening With a Newly Developed Universal Cylinder-Kombi-Tube Module for Motorized Nails-Description of a Surgical Technique.

    Science.gov (United States)

    Krettek, Christian; El Naga, Ashraf

    2017-10-01

    Segmental transport is an effective method of treatment for segmental defects, but the need for external fixation during the transport phase is a disadvantage. To avoid external fixation, we have developed a Cylinder-Kombi-Tube Segmental Transport (CKTST) module for combination with a commercially available motorized lengthening nail. This CKTST module allows for an all-internal segmental bone transport and also allows for optional lengthening if needed. The concept and surgical technique of CKTST are described and illustrated with a clinical case.

  6. The TTI slowness surface approximation

    KAUST Repository

    Stovas, A.

    2011-01-01

    The relation between the vertical and horizontal slownesses, better known as the dispersion relation, for a transversely isotropic media with titled symmetry axis {left parenthesis, less than bracket}TTI{right parenthesis, greater than bracket} requires solving a quartic polynomial, which does not admit a practical explicit solution to be used, for example, in downward continuation. Using a combination of perturbation theory with respect to the anelliptic parameter and Shanks transform to improve the accuracy of the expansion, we develop an explicit formula for the dispersion relation that is highly accurate for all practical purposes. It also reveals some insights into the anisotropy parameter dependency of the dispersion relation including the low impact that the anelliptic parameter has on the vertical placement of reflectors for small tilt in the symmetry angle. © 2011 Society of Exploration Geophysicists.

  7. Rapamycin slows aging in mice.

    Science.gov (United States)

    Wilkinson, John E; Burmeister, Lisa; Brooks, Susan V; Chan, Chi-Chao; Friedline, Sabrina; Harrison, David E; Hejtmancik, James F; Nadon, Nancy; Strong, Randy; Wood, Lauren K; Woodward, Maria A; Miller, Richard A

    2012-08-01

    Rapamycin increases lifespan in mice, but whether this represents merely inhibition of lethal neoplastic diseases, or an overall slowing in multiple aspects of aging is currently unclear. We report here that many forms of age-dependent change, including alterations in heart, liver, adrenal glands, endometrium, and tendon, as well as age-dependent decline in spontaneous activity, occur more slowly in rapamycin-treated mice, suggesting strongly that rapamycin retards multiple aspects of aging in mice, in addition to any beneficial effects it may have on neoplastic disease. We also note, however, that mice treated with rapamycin starting at 9 months of age have significantly higher incidence of testicular degeneration and cataracts; harmful effects of this kind will guide further studies on timing, dosage, and tissue-specific actions of rapamycin relevant to the development of clinically useful inhibitors of TOR action. © 2012 The Authors. Aging Cell © 2012 Blackwell Publishing Ltd/Anatomical Society of Great Britain and Ireland.

  8. Slow molecular recognition by RNA.

    Science.gov (United States)

    Gleitsman, Kristin R; Sengupta, Raghuvir N; Herschlag, Daniel

    2017-12-01

    Molecular recognition is central to biological processes, function, and specificity. Proteins associate with ligands with a wide range of association rate constants, with maximal values matching the theoretical limit set by the rate of diffusional collision. As less is known about RNA association, we compiled association rate constants for all RNA/ligand complexes that we could find in the literature. Like proteins, RNAs exhibit a wide range of association rate constants. However, the fastest RNA association rates are considerably slower than those of the fastest protein associations and fall well below the diffusional limit. The apparently general observation of slow association with RNAs has implications for evolution and for modern-day biology. Our compilation highlights a quantitative molecular property that can contribute to biological understanding and underscores our need to develop a deeper physical understanding of molecular recognition events. © 2017 Gleitsman et al.; Published by Cold Spring Harbor Laboratory Press for the RNA Society.

  9. Traditional Procurement is too Slow

    Directory of Open Access Journals (Sweden)

    Ann Kong

    2012-11-01

    Full Text Available This paper reports on an exploratory interview survey of construction project participants aimed at identifying the reasons for the decrease in use of the traditional, lump-sum, procurement system in Malaysia. The results show that most people believe it is too slow. This appears to be in part due to the contiguous nature of the various phase and stages of the process and especially the separation of the design and construction phases. The delays caused by disputes between the various parties are also seen as a contributory factor - the most prominent cause being the frequency of variations, with design and scope changes being a particular source of discontent. It is concluded that an up scaling of the whole of the time related reward/penalty system may be the most appropriate measure for the practice in future.

  10. Ultrasonic and densimetric titration applied for acid-base reactions.

    Science.gov (United States)

    Burakowski, Andrzej; Gliński, Jacek

    2014-01-01

    Classical acoustic acid-base titration was monitored using sound speed and density measurements. Plots of these parameters, as well as of the adiabatic compressibility coefficient calculated from them, exhibit changes with the volume of added titrant. Compressibility changes can be explained and quantitatively predicted theoretically in terms of Pasynski theory of non-compressible hydrates combined with that of the additivity of the hydration numbers with the amount and type of ions and molecules present in solution. It also seems that this development could be applied in chemical engineering for monitoring the course of chemical processes, since the applied experimental methods can be carried out almost independently on the medium under test (harmful, aggressive, etc.).

  11. Biophysical characterization of antibodies with isothermal titration calorimetry

    Directory of Open Access Journals (Sweden)

    Verna Frasca

    2016-07-01

    Full Text Available Antibodies play a key role in the immune response. Since antibodies bind antigens with high specificity and tight affinity, antibodies are an important reagent in experimental biology, assay development, biomedical research and diagnostics. Monoclonal antibodies are therapeutic drugs and used for vaccine development. Antibody engineering, biophysical characterization, and structural data have provided a deeper understanding of how antibodies function, and how to make better drugs. Isothermal titration calorimetry (ITC is a label-free binding assay, which measures affinity, stoichiometry, and binding thermodynamics for biomolecular interactions. When thermodynamic data are used together with structural and kinetic data from other assays, a complete structure-activity-thermodynamics profile can be constructed. This review article describes ITC, and discusses several applications on how data from ITC provides insights into how antibodies function, guide antibody engineering, and aid design of new therapeutic drugs.

  12. IMPEDANCE METHOD OF MEASURING OF THE TITRATABLE ACIDITY OF YOGURT

    Directory of Open Access Journals (Sweden)

    Miroslav Vasilev

    2016-10-01

    Full Text Available In the present work are analyzed studies related to changes in the active impedance component of the dairy environment caused by the flow of lactic fermentation and coagulation of casein in milk. The aim of this work was to determine the relationship between the relative change of titratable acidity and the relative change of active impedance component of the dairy environment with lactic fermentation, causing coagulation of the casein in milk. . The data were interpolated with cubic spline, visualizing how when the fat content increases, the electrical resistance increases too. All data, collected during the tests would complement and be used for solving the optimization problem to determine the time of completion of the coagulation in future work.

  13. Oxygen titration strategies in chronic neonatal lung disease.

    Science.gov (United States)

    Primhak, Robert

    2010-09-01

    The history of oxygen therapy in neonatology has been littered with error. Controversies remain in a number of areas of oxygen therapy, including targets and strategies in supplemental oxygen therapy in Chronic Neonatal Lung Disease (CNLD). This article reviews some of these controversies, and makes some recommendations based on the available evidence. In graduates of neonatal units who are left with CNLD, oxygen saturation should be kept above 93-95%, with levels below 90% being avoided as far as possible. Titration of oxygen should be done using oximetry recordings which include periods of different activities. Weaning of oxygen supplementation should only be done based on satisfactory recordings during a trial of a lower flow. There is insufficient evidence to say whether weaning for increasing hours a day or stepwise weaning to a continuous lower flow is a better method. Copyright 2010 Elsevier Ltd. All rights reserved.

  14. Sailing on the "C": A Vitamin Titration with a Twist

    Science.gov (United States)

    Sowa, S.; Kondo, A. E.

    2003-05-01

    The experiment takes the traditional redox titration of vitamin C using iodine with starch as an indicator, and presents it to the student as a challenge in guided-inquiry format. Two versions, with different levels of difficulty, are provided, to accommodate students with varying levels of problem-solving skills. The "challenge" is both quantitative and qualitative: if you were an eighteenth-century sea captain packing for a voyage to the New World, would you take oranges, lemons, limes, or grapefruits to prevent your crew from getting scurvy? The challenge ties in history, nutrition, and health with chemistry, and provides students an opportunity to work with familiar food products in the laboratory.

  15. The ion-sensitive field effect transistor in rapid acid-base titrations

    NARCIS (Netherlands)

    Bos, M.; Bergveld, Piet; van Veen-Blaauw, A.M.W.

    1979-01-01

    Ion-sensitive field effect transistors (ISFETs) are used as the pH sensor in rapid acid—base titrations. Titration speeds at least five times greater than those with glass electrodes are possible for accuracies better than ±1%.

  16. Quick titration of pergolide in cotreatment with domperidone is safe and effective

    NARCIS (Netherlands)

    Jansen, PAF; Herings, RMC; Samson, MM; Schuurmans-Daemen, LMPJ; Hovestadt, A; Verhaar, HJJ; Van Laar, T; de Vreede, P.

    2001-01-01

    The purpose of the study was to analyze efficacy and safety of quick pergolide titration combined with domperidone. In an open-label prospective study, pergolide was titrated in 16 days to a maximum of 3 mg/d doses as adjunctive treatment to L-Dopa in 10 elderly patients with Parkinson's disease.

  17. Efficacy of daytime continuous positive airway pressure titration in severe obstructive sleep apnoea.

    Science.gov (United States)

    Rudkowski, J C; Verschelden, P; Kimoff, R J

    2001-09-01

    The aim of this study was to evaluate manual nasal continuous positive airway pressure (nCPAP) titration during daytime polysomnography compared with conventional overnight titration for patients with severe obstructive sleep apnoea. Thirty-two patients who underwent daytime titration were retrospectively matched (for age, sex, body mass index and apnoea/hypopnoea index (AHI)) to a group titrated overnight during the same period. Successful titration was defined as the identification of the nCPAP level (effective nCPAP (Peff)) required to eliminate respiratory events during all sleep stages. After 3 months of therapy on nCPAP at Peff, nCPAP utilization history was obtained and a group of patients underwent a repeat polysomnogram (PSG) and completed a follow-up Epworth Sleepiness Scale (ESS) score. Initial titration was successful in 91% of daytime patients and 91% of overnight patients. The success of daytime titration was not related to diagnostic AHI or ESS score. Subjective nCPAP utilization was statistically similar in both groups. On the follow-up PSG, there were no significant differences between daytime (n=11) and overnight (n=11) patients in measures of sleep quality or respiratory disturbance. Both groups demonstrated similar and significant improvements in ESS score. These findings suggest that the effective nasal continuous positive airway pressure can be accurately established during daytime titration in a substantial proportion of severe, symptomatic obstructive sleep apnoea patients.

  18. The predictive value of drug-induced sleep endoscopy for CPAP titration in OSA patients.

    Science.gov (United States)

    Lan, Ming-Chin; Hsu, Yen-Bin; Lan, Ming-Ying; Huang, Yun-Chen; Kao, Ming-Chang; Huang, Tung-Tsun; Chiu, Tsan-Jen; Yang, Mei-Chen

    2017-12-15

    The aim of this study was to identify possible upper airway obstructions causing a higher continuous positive airway pressure (CPAP) titration level, utilizing drug-induced sleep endoscopy (DISE). A total of 76 patients with obstructive sleep apnea (OSA) underwent CPAP titration and DISE. DISE findings were recorded using the VOTE classification system. Polysomnographic (PSG) data, anthropometric variables, and patterns of airway collapse during DISE were analyzed with CPAP titration levels. A significant association was found between the CPAP titration level and BMI, oxygen desaturation index (ODI), apnea-hypopnea index (AHI), and neck circumference (NC) (P titration level (P titration level and any other collapse at the tongue base or epiglottis. By analyzing PSG data, anthropometric variables, and DISE results with CPAP titration levels, we can better understand possible mechanisms resulting in a higher CPAP titration level. We believe that the role of DISE can be expanded as a tool to identify the possible anatomical structures that may be corrected by oral appliance therapy or surgical intervention to improve CPAP compliance.

  19. Determination of Titratable Acidity in Wine Using Potentiometric, Conductometric, and Photometric Methods

    Science.gov (United States)

    Volmer, Dietrich A.; Curbani, Luana; Parker, Timothy A.; Garcia, Jennifer; Schultz, Linda D.; Borges, Endler Marcel

    2017-01-01

    This experiment describes a simple protocol for teaching acid-base titrations using potentiometry, conductivity, and/or photometry to determine end points without an added indicator. The chosen example examines the titratable acidity of a red wine with NaOH. Wines contain anthocyanins, the colors of which change with pH. Importantly, at the…

  20. flower extract as an improvised indicator in acid – base titration

    African Journals Online (AJOL)

    USER

    laboratory practical with an instructional material that is useful, economical, simple and accurate for the said titration. Therefore, it is recommended for integrated science and chemistry instructions. Keywords: Flower, acid, base, indicator, titration. INTRODUCTION. In Nigeria, factors militating against science education.

  1. Rapid and simple determination of oxyphenbutazone in dosage forms by biamperometric titration.

    Science.gov (United States)

    Sebková, D; Safarík, L

    1986-01-01

    Oxyphenbutazone was determined in the presence of glacial acetic acid, hydrochloric acid, and potassium bromide by bromometric titration with biamperometric end point indication. The course of the titration was followed with double platinum electrode with 100 mV of polarizing voltage.

  2. Lengthening of the normal tibia in a patient with hemihypertrophy caused by Klippel- Trenaunay-Weber syndrome: a case report.

    Science.gov (United States)

    Takata, Munetomo; Watanabe, Koji; Matsubara, Hidenori; Takato, Kei; Nomura, Issei; Tsuchiya, Hiroyuki

    2011-12-01

    We report a case of Klippel-Trenaunay-Weber syndrome in a 31-year-old woman who presented with hypertrophy of the left leg. She had severe osteoarthritic changes in the left hip joint secondary to the lack of acetabular coverage of the femoral head as the result of lateral inclination of the pelvis owing to leg-length discrepancy of 4 cm. The centre-edge angle (coverage ratio of the acetabulum to the femoral head) was improved from 15º to 33º after a foot lift. She underwent osteotomy and lengthening of the normal contralateral tibia using a Taylor spatial frame. Hip arthroplasty could be avoided as osteoarthritic changes of the hip joint had improved.

  3. SPECIAL CONSIDERATIONS REGARDING WARFARIN DOSE TITRATION IN PATIENTS WITH ATRIAL FIBRILLATION DEPENDING ON CLINICAL FACTORS

    Directory of Open Access Journals (Sweden)

    E. L. Artanova

    2011-01-01

    Full Text Available Aim. To study the relations of clinical characteristics and individual warfarin dose titration in patients with atrial fibrillation. Material and methods. Period of warfarin dose titration was analyzed in 68 patients with atrial fibrillation due to ischemic heart disease. Adjusted warfarin dose in milligram, duration of dose titration in days and maximal international normalized ratio (INR were taken into account. Sex, age, history of myocardial infarction and stroke, concomitant diseases, amiodarone therapy were considered among clinical characteristics. Results. Adjusted warfarin dose was significantly higher in obesity , and it was lower in case of experienced myocardial infarction. The INR highest levels and maximal amplitudes of its fluctuations were observed in patients with thyroid gland nodes and smokers. Period of warfarin dose titration was longer in patients treated with amiodarone. Conclusion. Warfarin dose titration in patients with atrial fibrillation depends on the presence of myocardial infarction, obesity , thyroid nodular changes, smoking and amiodarone treatment.

  4. Simple Modification of Karl-Fischer Titration Method for Determination of Water Content in Colored Samples

    Science.gov (United States)

    Tavčar, Eva; Turk, Erika; Kreft, Samo

    2012-01-01

    The most commonly used technique for water content determination is Karl-Fischer titration with electrometric detection, requiring specialized equipment. When appropriate equipment is not available, the method can be performed through visual detection of a titration endpoint, which does not enable an analysis of colored samples. Here, we developed a method with spectrophotometric detection of a titration endpoint, appropriate for moisture determination of colored samples. The reaction takes place in a sealed 4 ml cuvette. Detection is performed at 520 nm. Titration endpoint is determined from the graph of absorbance plotted against titration volume. The method has appropriate reproducibility (RSD = 4.3%), accuracy, and linearity (R 2 = 0.997). PMID:22567558

  5. Molybdenum (6) determination by the method of high-frequency and pH titration

    International Nuclear Information System (INIS)

    Lukianets, I.G.; Kulish, N.G.

    1981-01-01

    A possibility to determine Mo(6) using the method of high frequency and pH-metric titration is investigated. By means of the high frequency contact R-cell Mo(6) titration is performed using different precipitators: 8-oxiquinoline, lead nitrate and acetate and silver nitrate. It is established that the best conditions are achieved during titration of 67.2-1343 mg/10 ml Mo(6) with lead acetate (pH 4.5-6.5). Relative standard deviation Ssub(r) constitutes 0.005 pH-metric titration of Mo(6) with complexone 3 is studied. The range of Mo(6) concentrations determined constitutes 13.43-134.3 mg at pH initial value of 3.5-5.5. Relative standard deviation Ssub(r) constitutes 0.003. Techniques of molybdenum determination in ferromolybdenum using the method of high frequency and pH-metric titration are developed [ru

  6. Integration and global analysis of isothermal titration calorimetry data for studying macromolecular interactions.

    Science.gov (United States)

    Brautigam, Chad A; Zhao, Huaying; Vargas, Carolyn; Keller, Sandro; Schuck, Peter

    2016-05-01

    Isothermal titration calorimetry (ITC) is a powerful and widely used method to measure the energetics of macromolecular interactions by recording a thermogram of differential heating power during a titration. However, traditional ITC analysis is limited by stochastic thermogram noise and by the limited information content of a single titration experiment. Here we present a protocol for bias-free thermogram integration based on automated shape analysis of the injection peaks, followed by combination of isotherms from different calorimetric titration experiments into a global analysis, statistical analysis of binding parameters and graphical presentation of the results. This is performed using the integrated public-domain software packages NITPIC, SEDPHAT and GUSSI. The recently developed low-noise thermogram integration approach and global analysis allow for more precise parameter estimates and more reliable quantification of multisite and multicomponent cooperative and competitive interactions. Titration experiments typically take 1-2.5 h each, and global analysis usually takes 10-20 min.

  7. Simple Modification of Karl-Fischer Titration Method for Determination of Water Content in Colored Samples

    Directory of Open Access Journals (Sweden)

    Eva Tavčar

    2012-01-01

    Full Text Available The most commonly used technique for water content determination is Karl-Fischer titration with electrometric detection, requiring specialized equipment. When appropriate equipment is not available, the method can be performed through visual detection of a titration endpoint, which does not enable an analysis of colored samples. Here, we developed a method with spectrophotometric detection of a titration endpoint, appropriate for moisture determination of colored samples. The reaction takes place in a sealed 4 ml cuvette. Detection is performed at 520 nm. Titration endpoint is determined from the graph of absorbance plotted against titration volume. The method has appropriate reproducibility (RSD=4.3%, accuracy, and linearity (2=0.997.

  8. Simple modification of karl-Fischer titration method for determination of water content in colored samples.

    Science.gov (United States)

    Tavčar, Eva; Turk, Erika; Kreft, Samo

    2012-01-01

    The most commonly used technique for water content determination is Karl-Fischer titration with electrometric detection, requiring specialized equipment. When appropriate equipment is not available, the method can be performed through visual detection of a titration endpoint, which does not enable an analysis of colored samples. Here, we developed a method with spectrophotometric detection of a titration endpoint, appropriate for moisture determination of colored samples. The reaction takes place in a sealed 4 ml cuvette. Detection is performed at 520 nm. Titration endpoint is determined from the graph of absorbance plotted against titration volume. The method has appropriate reproducibility (RSD = 4.3%), accuracy, and linearity (R(2) = 0.997).

  9. Analysis of callus pattern of tibia lengthening in achondroplasia and a novel method of regeneration assessment using pixel values

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Suryaudai; Song, Hae-Ryong; Venkatesh, K.P.; Modi, Hitesh N.; Jang, Ki-Mo; Kim, Seung J. [Korea University Guro Hospital, Rare Diseases Institute, Department of Orthopedic Surgery, Seoul (Korea); Park, Man Sik [Korea University, Department of Biostatistics, College of Medicine, Seoul (Korea)

    2010-03-15

    To relate morphology of new bone formation to outcome after tibial lengthening performed in patients with achondroplasia. A retrospective analysis of 60 tibial segments in 30 achondroplasia patients was performed. There were 22 female patients and eight male patients, with a mean age of 9.8 years. New bone formation was classified by shape, homogeneity and density. Pixel values in relation to original bone were measured using a picture-archiving communication system (PACS). Clinical outcome was described by the external fixator and maturation indices. Mean lengthening was 9.2 cm (range 3-12.7 cm). The mean external fixator index was 23.4 (range 15.1-50). The mean maturation index was 12.3 days/cm (range 6-40 days/cm). Homogeneous pathways were associated with the best clinical results (fixator index 20.4, maturation index 10.8), followed by heterogeneous pathway (external fixator index 26.5, maturation index 16.8) and radiolucent pathway (fixator index 31.2, maturation index 21.4). Both cylindrical (external fixator index 25.2, maturation index 14.5) and concave (external fixator index 26.6, maturation index 16.3) callus shapes were favourable. Mineralization of new bone became equal to that of normal bone within 16 weeks (mean) for homogeneous pathway, 12 weeks for heterogeneous pathway and 32 weeks for lucent pathway. The type of new bone formation seen on radiographs is related to clinical outcome, with homogeneous pathways being the most favourable ones. (orig.)

  10. A novel method of lengthening the accessory nerve for direct coaptation during nerve repair and nerve transfer procedures.

    Science.gov (United States)

    Tubbs, R Shane; Maldonado, Andrés A; Stoves, Yolanda; Fries, Fabian N; Li, Rong; Loukas, Marios; Oskouian, Rod J; Spinner, Robert J

    2018-01-01

    OBJECTIVE The accessory nerve is frequently repaired or used for nerve transfer. The length of accessory nerve available is often insufficient or marginal (under tension) for allowing direct coaptation during nerve repair or nerve transfer (neurotization), necessitating an interpositional graft. An attractive maneuver would facilitate lengthening of the accessory nerve for direct coaptation. The aim of the present study was to identify an anatomical method for such lengthening. METHODS In 20 adult cadavers, the C-2 or C-3 connections to the accessory nerve were identified medial to the sternocleidomastoid (SCM) muscle and the anatomy of the accessory nerve/cervical nerve fibers within the SCM was documented. The cervical nerve connections were cut. Lengths of the accessory nerve were measured. Samples of the cut C-2 and C-3 nerves were examined using immunohistochemistry. RESULTS The anatomy and adjacent neural connections within the SCM are complicated. However, after the accessory nerve was "detethered" from within the SCM and following transection, the additional length of the accessory nerve increased from a mean of 6 cm to a mean of 10.5 cm (increase of 4.5 cm) after cutting the C-2 connections, and from a mean of 6 cm to a mean length of 9 cm (increase of 3.5 cm) after cutting the C-3 connections. The additional length of accessory nerve even allowed direct repair of an infraclavicular target (i.e., the proximal musculocutaneous nerve). The cervical nerve connections were shown not to contain motor fibers. CONCLUSIONS An additional length of the accessory nerve made available in the posterior cervical triangle can facilitate direct repair or neurotization procedures, thus eliminating the need for an interpositional nerve graft, decreasing the time/distance for regeneration and potentially improving clinical outcomes.

  11. Acid-base titrations by stepwise addition of equal volumes of titrant with special reference to automatic titrations-III Presentation of a fully automatic titration apparatus and of results supporting the theories given in the preceding parts.

    Science.gov (United States)

    Pehrsson, L; Ingman, F

    1977-02-01

    This paper forms Part III of a series in which the first two parts describe methods for evaluating titrations performed by stepwise addition of equal volumes of titrant. The great advantage of these methods is that they do not require an accurate calibration of the electrode system. This property makes the methods very suitable for routine work. e.g., in automatic analysis. An apparatus for performing such titrations automatically is presented. Further, results of titrations of monoprotic acids, a diprotic acid, an ampholyte, a mixture of an acid with its conjugate base, and mixtures of two acids with a small difference between the stability constants are given. Most of these titrations cannot be evaluated by the Gran or Hofstee methods but yield results having errors of the order of 0.1% if the methods proposed in Parts I and II of this series are employed. The advantages of the method of stepwise addition of equal volumes of titrant combined with the proposed evaluation methods, in comparison with common methods such as titration to a preset pH, are that all the data are used in the evaluation, permitting a statistical treatment and giving better possibilities for tracing systematic errors.

  12. Initial Evaluation of a Titration Appliance for Temporary Treatment of Obstructive Sleep Apnea.

    Science.gov (United States)

    Levendowski, Daniel J; Morgan, Todd; Westbrook, Philip

    2012-01-01

    Custom oral appliances that adjustably advance the mandible provide superior outcomes when treating patients with moderate or severe sleep apnea. Custom appliances, however, are expensive, must be fitted by a dentist, and the likelihood of successful outcomes are difficult to predict. An inexpensive trial appliance, if proven efficacious, might be used to predict custom appliance outcomes or to provide temporary therapeutic benefit. The aim of this initial study was to assess the treatment efficacy of a novel titration oral appliance with that of an optimized custom appliance. Seventeen patients, treated with a custom oral appliance for at least one year, successfully completed a three-night home sleep test. The baseline obstructive sleep apnea severity was established on Night 1 with seven patients exhibiting severe, six moderate and four mild apnea/hypopnea indexes. Patients were randomly assigned to wear their custom appliance or the titration appliance on Nights 2 and 3. Significant reductions in the mean overall and supine apnea indexes (p titration and custom appliances. The proportion of patients who exhibited at least a 50% reduction in the overall apnea index and supine apnea/hypopnea were similar for the titration and custom appliance (~60%). The custom appliance reduced the overall apnea/hypopnea index by 50% in a greater proportion of the patients compared to the titration appliance (77% vs. 53%). The titration appliance significantly reduced the degree of hypoxic exposure across sleep disordered breathing events overall (p titration appliance, but preferred the titration appliance to no therapy. The titration appliance may be useful in assessing oral appliance treatment efficacy. When set to 70% of maximum protrusion, the titration appliance may provide immediate, temporary therapeutic benefit.

  13. Dose titration of BAF312 attenuates the initial heart rate reducing effect in healthy subjects.

    Science.gov (United States)

    Legangneux, Eric; Gardin, Anne; Johns, Donald

    2013-03-01

    Previous studies have shown transient decreases in heart rate (HR) following administration of sphingosine 1-phosphate (S1P) receptor modulators including BAF312. This study was conducted to determine whether dose titration of BAF312 reduces or eliminates these effects. Fifty-six healthy subjects were randomized 1:1:1:1 to receive BAF312 in one of two dose titration (DT) regimens (DT1 and DT2: 0.25-10 mg over 9-10 days), no titration (10 mg starting dose) or placebo. Pharmacodynamic and pharmacokinetic parameters were assessed. Neither DT1 nor DT2 resulted in clinically significant bradycardia or atrioventricular conduction effects. Both titration regimens showed a favourable difference on each of days 1-12 vs. the non-titration regimen on day 1 for HR effects (P titration was 1.18 (95% confidence interval [CI] 1.13, 1.23) and 1.14 (95% CI 1.09, 1.18) for DT2 (both P titration HRs showed considerable separation from placebo throughout the study. There was no statistically significant reduction in HR vs. placebo on day 1 in either titration regimen. On days 3-7 subjects in DT1 and DT2 experienced minor reductions in HR vs. placebo (approximately 5 beats min⁻¹; P ≤ 0.0001). From days 9-12, HRs in both titration regimens were comparable with placebo. Both titration regimens effectively attenuated the initial bradyarrhythmia observed on day 1 of treatment with BAF312 10 mg. © 2012 Novartis Institutes for BioMedical Research (NIBIR). British Journal of Clinical Pharmacology © 2012 The British Pharmacological Society.

  14. Potentiometric titrations of molybdenum and vanadium in aqueous and mixed so lvents

    International Nuclear Information System (INIS)

    Das, S.K.; Dhaneshwar, R.G.

    1990-01-01

    Potentiometric titration method was developed for molybdenum, employing different electrode systems. Molybdenum(VI) is reduced to molybdenum(V) by ferrous solution in presence of phosphoric acid and then titrated with potassium dichromate. It was found that ferrous concentration should be five times more than molybdenum and phosphoric acid should be 1.0 ml for 0.1N titration and 0.5 ml for lower concentration titrations. The method is also applicable to vanadium titrations. Employing Au/SCE and Pt/SCE systems, it was observed that generally curve heights obtained for platinum electrode are higher than those for gold electrode. Also for both the electrode systems, the curve heights for vanadium titrations were found to be more than those for molybdenum. Lower limits of titrations for Au/SCE system are 0.01N for molybdenum and 0.0001N for vanadium, whereas for Pt/SCE system, the lower limits obtained were 0.01N for both molybdenum and vanadium titrations. In order to improve the sensitivities of the method, the bimetallic electrode systems Au/Pt and Pt/Au were employed. Au/Pt system was found to give better results than Pt/Au systems. Addition of organic solvent was found to have beneficial effects for titrations of 0.001N and below. Methanol was found to be a better solvent than ethanol. Molybdenum titrations, at 0.0001N level could be performed in methanol with Au/Pt system, which is to b e generally preferred than Pt/Au system. (author). 7 refs., 3 tabs

  15. Macromolecular competition titration method accessing thermodynamics of the unmodified macromolecule-ligand interactions through spectroscopic titrations of fluorescent analogs.

    Science.gov (United States)

    Bujalowski, Wlodzimierz; Jezewska, Maria J

    2011-01-01

    Analysis of thermodynamically rigorous binding isotherms provides fundamental information about the energetics of the ligand-macromolecule interactions and often an invaluable insight about the structure of the formed complexes. The Macromolecular Competition Titration (MCT) method enables one to quantitatively obtain interaction parameters of protein-nucleic acid interactions, which may not be available by other methods, particularly for the unmodified long polymer lattices and specific nucleic acid substrates, if the binding is not accompanied by adequate spectroscopic signal changes. The method can be applied using different fluorescent nucleic acids or fluorophores, although the etheno-derivatives of nucleic acid are especially suitable as they are relatively easy to prepare, have significant blue fluorescence, their excitation band lies far from the protein absorption spectrum, and the modification eliminates the possibility of base pairing with other nucleic acids. The MCT method is not limited to the specific size of the reference nucleic acid. Particularly, a simple analysis of the competition titration experiments is described in which the fluorescent, short fragment of nucleic acid, spanning the exact site-size of the protein-nucleic acid complex, and binding with only a 1:1 stoichiometry to the protein, is used as a reference macromolecule. Although the MCT method is predominantly discussed as applied to studying protein-nucleic acid interactions, it can generally be applied to any ligand-macromolecule system by monitoring the association reaction using the spectroscopic signal originating from the reference macromolecule in the presence of the competing macromolecule, whose interaction parameters with the ligand are to be determined. Copyright © 2011 Elsevier Inc. All rights reserved.

  16. Macromolecular Competition Titration Method: Accessing Thermodynamics of the Unmodified Macromolecule–Ligand Interactions Through Spectroscopic Titrations of Fluorescent Analogs

    Science.gov (United States)

    Bujalowski, Wlodzimierz; Jezewska, Maria J.

    2011-01-01

    Analysis of thermodynamically rigorous binding isotherms provides fundamental information about the energetics of the ligand–macromolecule interactions and often an invaluable insight about the structure of the formed complexes. The Macromolecular Competition Titration (MCT) method enables one to quantitatively obtain interaction parameters of protein–nucleic acid interactions, which may not be available by other methods, particularly for the unmodified long polymer lattices and specific nucleic acid substrates, if the binding is not accompanied by adequate spectroscopic signal changes. The method can be applied using different fluorescent nucleic acids or fluorophores, although the etheno-derivatives of nucleic acid are especially suitable as they are relatively easy to prepare, have significant blue fluorescence, their excitation band lies far from the protein absorption spectrum, and the modification eliminates the possibility of base pairing with other nucleic acids. The MCT method is not limited to the specific size of the reference nucleic acid. Particularly, a simple analysis of the competition titration experiments is described in which the fluorescent, short fragment of nucleic acid, spanning the exact site-size of the protein–nucleic acid complex, and binding with only a 1:1 stoichiometry to the protein, is used as a reference macromolecule. Although the MCT method is predominantly discussed as applied to studying protein–nucleic acid interactions, it can generally be applied to any ligand–macromolecule system by monitoring the association reaction using the spectroscopic signal originating from the reference macromolecule in the presence of the competing macromolecule, whose interaction parameters with the ligand are to be determined. PMID:21195223

  17. Device for lengthening of a musculotendinous unit by direct continuous traction in the sheep

    Directory of Open Access Journals (Sweden)

    Zumstein Matthias A

    2012-05-01

    Full Text Available Abstract Background Retraction, atrophy and fatty infiltration are signs subsequent to chronic rotator cuff tendon tears. They are associated with an increased pennation angle and a shortening of the muscle fibers in series. These deleterious changes of the muscular architecture are not reversible with current repair techniques and are the main factors for failed rotator cuff tendon repair. Whereas fast stretching of the retracted musculotendinous unit results in proliferation of non-contractile fibrous tissue, slow stretching may lead to muscle regeneration in terms of sarcomerogenesis. To slowly stretch the retracted musculotendinous unit in a sheep model, two here described tensioning devices have been developed and mounted on the scapular spine of the sheep using an expandable threaded rod, which has been interposed between the retracted tendon end and the original insertion site at the humeral head. Traction is transmitted in line with the musculotendinous unit by sutures knotted on the expandable threaded rod. The threaded rod of the tensioner is driven within the body through a rotating axis, which enters the body on the opposite side. The tendon end, which was previously released (16 weeks prior from its insertion site with a bone chip, was elongated with a velocity of 1 mm/day. Results After several steps of technical improvements, the tensioner proved to be capable of actively stretching the retracted and degenerated muscle back to the original length and to withstand the external forces acting on it. Conclusion This technical report describes the experimental technique for continuous elongation of the musculotendinous unit and reversion of the length of chronically shortened muscle.

  18. The effects of surgical lengthening of hamstring muscles in children with cerebral palsy--the consequences of pre-operative muscle length measurement.

    Science.gov (United States)

    Laracca, Ettore; Stewart, Caroline; Postans, Neil; Roberts, Andrew

    2014-03-01

    Children with cerebral palsy often undergo multiple orthopaedic surgical procedures in a single episode. Evidence of the effectiveness of individual components within the overall package is sparse. The introduction of musculoskeletal modelling in Oswestry has led to a more conservative management approach being taken with hamstring muscles for children walking in a degree of crouch. Muscles which were shown to be of at least normal length at initial contact were not surgically lengthened, as would have been the case previously. A retrospective review of 30 such patients was therefore possible, comparing 15 patients treated before the policy change who had their hamstrings lengthened with 15 treated after who did not. All patients had pre and post operative gait assessments and significant changes were observed for each group separately and for the two groups when compared. The comparison revealed that preserving the hamstrings does tend to reduce, and therefore normalize, the dynamic muscle length. Examination of the two patient groups separately, however, reveals a more complex picture with more global gait improvements seen when the hamstrings were lengthened. No absolute recommendation can be made to inform the clinical management of all children with normal to long hamstring muscles during gait. The final decision of whether to include a hamstring lengthening will need to take into account the characteristics of the individual child. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Good clinical practice guide for opioids in pain management: the three Ts - titration (trial, tweaking (tailoring, transition (tapering

    Directory of Open Access Journals (Sweden)

    Flaminia Coluzzi

    2016-06-01

    Full Text Available ABSTRACT BACKGROUND AND OBJECTIVES: Achieving good clinical practice in the use of opioids as part of a comprehensive pain management regimen can face significant challenges. Despite guidelines from governmental and pain society/organization sources, there are still significant hurdles. A review of some basic tenets of opioid analgesia based on current published knowledge and experiences about this important healthcare imperative is warranted. CONTENT: Consistent with guidelines, the literature supports using the lowest total opioid dose that provides adequate pain control with the fewest adverse effects. Titration (or trial during opioid initiation is a way of starting low and going slow (and assessing the appropriateness of a specific opioid and formulation. Recognizing that multiple factors contribute to an individual's personal experience of pain, the physical, psychological, social, cultural, spiritual, pharmacogenomic, and behavioral factors of the individual patient should be taken into account (tweaking, or tailoring. Finally, for those patients for whom transition (tapering from opioid is desired, doing so too rapidly can have negative consequences and minimization of problems during this step can be achieved by proper tapering. CONCLUSION: We conclude that a simultaneously aggressive, yet conservative, approach is advocated in the literature in which opioid therapy is divided into three key steps (the 3 T's: titration (or trial, tweaking (or tailoring, and transition (or tapering. Establishment of the 3 T's along with the application of other appropriate good medical practice and clinical experience/judgment, including non-pharmacologic approaches, can assist healthcare providers in the effort to achieve optimal management of pain.

  20. Off-resonance slow light

    Science.gov (United States)

    Shakhmuratov, R. N.; Odeurs, J.

    2008-12-01

    We consider the propagation of a light pulse in a medium with a single resonance. If the frequency of the pulse is tuned far from resonance and the pulse duration is much shorter than the lifetime of the excited state of the resonant particles in the medium (atoms in a gas, impurity ions in a solid, etc.), the group velocity of the pulse is appreciably reduced. It is shown that the slowing down of the group velocity of the pulse is accompanied with a pulse chirp, which produces a pulse broadening in time. It is proposed to use two samples in sequence with opposite chirps (up chirp and down chirp or vice versa) compensating the pulse broadening. Then the pulse can be delayed with almost no losses, distortion, and broadening. However, there is a maximum distance, beyond which the pulse experiences corruption. Pumping with an auxiliary laser beam can control the delay time of the light pulse in the medium. Conditions to eliminate the contribution of the dephasing processes in the pulse propagation are considered.

  1. Plant domestication slows pest evolution.

    Science.gov (United States)

    Turcotte, Martin M; Lochab, Amaneet K; Turley, Nash E; Johnson, Marc T J

    2015-09-01

    Agricultural practices such as breeding resistant varieties and pesticide use can cause rapid evolution of pest species, but it remains unknown how plant domestication itself impacts pest contemporary evolution. Using experimental evolution on a comparative phylogenetic scale, we compared the evolutionary dynamics of a globally important economic pest - the green peach aphid (Myzus persicae) - growing on 34 plant taxa, represented by 17 crop species and their wild relatives. Domestication slowed aphid evolution by 13.5%, maintained 10.4% greater aphid genotypic diversity and 5.6% higher genotypic richness. The direction of evolution (i.e. which genotypes increased in frequency) differed among independent domestication events but was correlated with specific plant traits. Individual-based simulation models suggested that domestication affects aphid evolution directly by reducing the strength of selection and indirectly by increasing aphid density and thus weakening genetic drift. Our results suggest that phenotypic changes during domestication can alter pest evolutionary dynamics. © 2015 John Wiley & Sons Ltd/CNRS.

  2. Applications of Slow Light in Telecommunications

    National Research Council Canada - National Science Library

    Boyd, Robert W; Gauthier, Daniel J; Gaeta, Alexander L

    2006-01-01

    .... Now, optical scientists are turning their attention toward developing useful applications of slow light, including controllable optical delay lines, optical buffers and true time delay methods...

  3. Electroencephalographic slow waves prior to sleepwalking episodes.

    Science.gov (United States)

    Perrault, Rosemarie; Carrier, Julie; Desautels, Alex; Montplaisir, Jacques; Zadra, Antonio

    2014-12-01

    Recent studies have suggested that the onset of sleepwalking episodes may be preceded by fluctuations in slow-wave sleep electroencephalographic characteristics. However, whether or not such fluctuations are specific to sleepwalking episodes or generalized to all sleep-wake transitions in sleepwalkers remains unknown. The goal of this study was to compare spectral power for delta (1-4 Hz) and slow delta (0.5-1 Hz) as well as slow oscillation density before the onset of somnambulistic episodes versus non-behavioral awakenings recorded from the same group of sleepwalkers. A secondary aim was to describe the time course of observed changes in slow-wave activity and slow oscillations during the 3 min immediately preceding the occurrence of somnambulistic episodes. Twelve adult sleepwalkers were investigated polysomnographically during the course of one night. Slow-wave activity and slow oscillation density were significantly greater prior to patients' somnambulistic episodes as compared with non-behavioral awakenings. However, there was no evidence for a gradual increase over the 3 min preceding the episodes. Increased slow-wave activity and slow oscillation density appear to be specific to sleepwalking episodes rather than generalized to all sleep-wake transitions in sleepwalkers. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Acid-base titrations by stepwise addition of equal volumes of titrant with special reference to automatic titrations-II Theory of titration of mixtures of acids, polyprotic acids, acids in mixture with weak bases, and ampholytes.

    Science.gov (United States)

    Pehrsson, L; Ingman, F; Johansson, S

    A general method for evaluating titration data for mixtures of acids and for acids in mixture with weak bases is presented. Procedures are given that do not require absolute [H]-data, i.e., relative [H]-data may be used. In most cases a very rough calibration of the electrode system is enough. Further, for simple systems, very approximate values of the stability constants are sufficient. As examples, the titration of the following are treated in some detail: a mixture of two acids, a diprotic acid, an acid in presence of its conjugate base, and an ampholyte.

  5. Monitoring Acid–Base Titrations on Wax Printed Paper Microzones Using a Smartphone

    Directory of Open Access Journals (Sweden)

    Sandro A. Nogueira

    2017-05-01

    Full Text Available This study describes the use of a smartphone for monitoring acid–base titrations on wax printed paper microzones. An array of twelve microzones of 5 mm diameter each was wax printed on filter paper. The analytical performance of the proposed devices was explored with acid–base titrations examples, where jaboticaba peel extract was used as a natural pH indicator. The color intensity was captured using a smartphone and analyzed through a free App named Photometrix®. Before titrations, color intensity versus pH was calibrated to be used as a reference in titrations as (i strong acid versus strong base; (ii strong base versus strong acid; and (iii weak acid versus strong base. In all examples, images were obtained after the addition of each aliquot of titrant solutions. The obtained titration curves showed the same behavior as the conventional titration curves. After evaluating the feasibility of the proposed methodology, the concentration level of acetic acid was obtained in three vinegar samples. Although the obtained values ranged from 5% to 8% compared to the concentrations on the conventional method, the proposed methodology presented high analytical reliability. The calculated concentrations of acetic acid in three samples ranged from 3.87% to 3.93%, and the proposed methodology did not significantly differ from classic acid–base titration at a confidence level of 95%. The acid–base titration on paper-based devices is outstanding, since any titration can be completed within 5 min using 20 µL volumes. Besides, the use of a smartphone to capture images followed by analysis in a free app offers simplicity to all users. The proposed methodology arises as a new strand to be exploited in the diffusion of the analytical chemistry education field as well as an alternative for quantitative analysis with extremely simplified instrumentation.

  6. Simultaneous determination of equivalence volumes and acid dissociation constants from potentiometric titration data.

    Science.gov (United States)

    Papanastasiou, G; Ziogas, I

    1995-06-01

    New iterative methods for analysis of potentiometric titration data of (a) mixtures of weak monoprotic acids with their conjugate bases, (b) solutions of polyprotic (di- and triprotic) acids, and (c) mixtures of two diprotic acids are presented. These methods, using data exclusively resulting from the acidic region of the titration curve permits the accurate determination of the analytical concentration of one or more acids even if the titration is stopped well before the end point of the titration. For the titration of a solution containing a conjugate acid/base pair, the proposed procedure enables the extraction of the initial composition of the mixture, as well as the dissociation constant of the concerned acid. Thus, it is possible by this type of analysis to distinguish whether a weak acid has been contaminated by a strong base and define the extent of the contamination. On the other hand, for the titration of polyprotic acids, the proposed approach enables the extraction of the accurate values of the equivalence volume and the dissociation constants K(i) even when the ionization stages overlap. Finally, for the titration of a mixture of two diprotic acids the proposed procedure enables the determination of the composition of the mixture even if the sum of the concentrations of the acids is not known. This method can be used in the analysis of solutions containing two diastereoisomeric forms of a weak diprotic acid. The test of the proposed procedures by means of ideal and Monte Carlo simulated data revealed that these methods are fairly applicable even when the titration data are considerably obscured by 'noise' or contain an important systematic error. The proposed procedures were also successfully applied to experimental titration data.

  7. Implementation of a pharmacist-managed heart failure medication titration clinic.

    Science.gov (United States)

    Martinez, Amanda S; Saef, Jerold; Paszczuk, Anna; Bhatt-Chugani, Hetal

    2013-06-15

    The development, implementation, and initial results of a pharmacist-managed heart failure (HF) medication titration clinic are described. In a quality-improvement initiative at a Veterans Affairs health care system, clinical pharmacists were incorporated into the hospital system's interprofessional outpatient HF clinic. In addition, a separate pharmacist-managed HF medication titration clinic was established, in which pharmacists were granted an advanced scope of practice and prescribing privileges, enabling them to initiate and adjust medication dosages under specific protocols jointly established by cardiology and pharmacy staff. Pharmacists involved in the titration clinic tracked patients' daily body weight, vital signs, and volume status using telephone-monitoring technology and via patient interviews. A retrospective chart review comparing achievement of target doses of angiotensin-converting enzyme inhibitor (ACEI), angiotensin-receptor blocker (ARB), and β-blocker therapies in a group of patients (n = 28) whose dosage titrations were carried out by nurses or physicians prior to implementation of the pharmacist-managed HF medication titration clinic and a group of patients (n = 27) enrolled in the medication titration clinic during its first six months of operation indicated that target ACEI and ARB doses were achieved in a significantly higher percentage of pharmacist-managed titration clinic enrollees (52.9% versus 31%, p = 0.007). Patients enrolled in the pharmacist-managed HF medication titration clinic also had a significantly higher rate of attainment of optimal β-blocker doses (49% versus 24.7%, p = 0.012). Implementation of a pharmacist-managed HF medication titration clinic increased the percentage of patients achieving optimal ACEI, ARB, and β-blocker dosages.

  8. Predicting proton titration in cationic micelle and bilayer environments

    Science.gov (United States)

    Morrow, Brian H.; Eike, David M.; Murch, Bruce P.; Koenig, Peter H.; Shen, Jana K.

    2014-08-01

    Knowledge of the protonation behavior of pH-sensitive molecules in micelles and bilayers has significant implications in consumer product development and biomedical applications. However, the calculation of pKa's in such environments proves challenging using traditional structure-based calculations. Here we apply all-atom constant pH molecular dynamics with explicit ions and titratable water to calculate the pKa of a fatty acid molecule in a micelle of dodecyl trimethylammonium chloride and liquid as well as gel-phase bilayers of diethyl ester dimethylammonium chloride. Interestingly, the pKa of the fatty acid in the gel bilayer is 5.4, 0.4 units lower than that in the analogous liquid bilayer or micelle, despite the fact that the protonated carboxylic group is significantly more desolvated in the gel bilayer. This work illustrates the capability of all-atom constant pH molecular dynamics in capturing the delicate balance in the free energies of desolvation and Coulombic interactions. It also shows the importance of the explicit treatment of ions in sampling the protonation states. The ability to model dynamics of pH-responsive substrates in a bilayer environment is useful for improving fabric care products as well as our understanding of the side effects of anti-inflammatory drugs.

  9. Effect of a stirring process in an isothermal titration microcalorimeter

    Energy Technology Data Exchange (ETDEWEB)

    Socorro, F.; Nuez, I. de la; Alvarez, L.; Rodriguez de Rivera, M

    2004-10-01

    In this paper, it is analysed the way in which the thermodynamic results obtained in an isothermal titration microcalorimeter, with continuous injection of a liquid and a variable mass are affected. Two aspects are presented, the first one refers to a variation in the baseline that takes place when the liquid mass is increased in the laboratory cell, this variation is due to the change in the thermal coupling between the stirrer and its contact with the thermostat. The second aspect is the analysis of the effect of the stirring process and the injection velocity on the homogenization of the remaining mixture in the laboratory cell. The aim of the study of these two previous aspects is to increase the accuracy of the thermodynamic measures carried out. The variation of the baseline affects in a percentage from 1 to 2% of the total energy developed. It is also shown the necessity of a stirring process according to the injection velocity in order to obtain a homogeneous mixture at every instant. This fact allows to carry out a deconvolution of the calorimetric signal and to obtain directly the power developed in the mixture process in terms of the amount of mixed substance [Meas. Sci. Technol. 1 (1990) pp. 1285-1290; J. Thermal Analysis 41 (1994) pp. 1385-1392].

  10. Monitoring Acid–Base Titrations on Wax Printed Paper Microzones Using a Smartphone

    OpenAIRE

    Sandro A. Nogueira; Lucas R. Sousa; Nathália K. L. Silva; Pedro H. F. Rodrigues; Wendell K. T. Coltro

    2017-01-01

    This study describes the use of a smartphone for monitoring acid–base titrations on wax printed paper microzones. An array of twelve microzones of 5 mm diameter each was wax printed on filter paper. The analytical performance of the proposed devices was explored with acid–base titrations examples, where jaboticaba peel extract was used as a natural pH indicator. The color intensity was captured using a smartphone and analyzed through a free App named Photometrix®. Before titrations, color int...

  11. Amperometric titration of thorium and some lanthanoids in acetic-acid medium using two indicator electrodes

    International Nuclear Information System (INIS)

    Khadeev, V.A.; Gevorgyan, A.M.; Talipov, Sh.T.; Kostylev, V.S.

    1979-01-01

    The votammetric behaviour of nitriletrimethylphosphonic acid (NTMP) in the medium of anhydrous acetic acid with different backgrounds in the anode region of polarization of a platinum microdisk electrode, is studied. The optimal conditions are found for the amperometric titration with two indicator electrodes of thorium and same lanthanides by a NTMP solution in anhydrous acetic medium. The influence of foreign anions and cations on the results of titration by the NTPM solution in anhydrous acetic acid is studied. The selectivity of titration in anhydrous medium is higher than in aqueous

  12. Free Software Development. 3. Numerical Description of Soft Acid with Soft Base Titration

    OpenAIRE

    Lorentz JÄNTSCHI; Horea Iustin NAŞCU

    2002-01-01

    The analytical methods of qualitative and quantitative determination of ions in solutions are very flexible to automation. The present work is focus on modeling the process of titration and presents a numerical simulation of acid-base titration. A PHP program to compute all iterations in titration process that solves a 3th rank equation to find value of pH for was built and is available through http internet protocol at the address: http://vl.academicdirect.org/molecular_dynamics/ab_titra...

  13. On the Physical Meaning of the Isothermal Titration Calorimetry Measurements in Calorimeters with Full Cells

    Science.gov (United States)

    Grolier, Jean-Pierre E.; del Río, Jose Manuel

    2009-01-01

    We have performed a detailed study of the thermodynamics of the titration process in an isothermal titration calorimeter with full cells. We show that the relationship between the enthalpy and the heat measured is better described in terms of the equation Δ H = Winj + Q (where Winj is the work necessary to carry out the titration) than in terms of ΔH = Q. Moreover, we show that the heat of interaction between two components is related to the partial enthalpy of interaction at infinite dilution of the titrant component, as well as to its partial volume of interaction at infinite dilution. PMID:20054472

  14. Characterization of antibody-chelator conjugates: Determination of chelator content by terbium fluorescence titration

    Energy Technology Data Exchange (ETDEWEB)

    Brandt, K.D.; Schnobrich, K.E.; Johnson, D.K. (Abbott Laboratories, Department 90M, Abbott Park, IL (United States))

    1991-01-01

    Fluorescence titrations were performed by adding varying mole ratios of terbium(III) to antibody conjugates formed by benzyl isothiocyanate derivatives of three different polyaminopolycarboxylate chelators (NTA, EDTA, and DTPA) and the results compared to values for average chelator content obtained by cobalt-57 binding assays. For two different murine monoclonal antibodies, the average chelator content obtained by terbium fluorescence titration correlated closely with that measured by the cobalt-57 binding assay. It is concluded that lanthanide fluorescence titrations provide a useful alternative to radiometal binding assays for the determination of chelator content in protein-chelator conjugates.

  15. Resonant absorption of the slow sausage wave in the slow continuum

    Science.gov (United States)

    Yu, D. J.; Van Doorsselaere, T.; Goossens, M.

    2017-06-01

    Aims: General analytical formulas for the damping rate by resonant absorption of slow sausage modes in the slow (cusp) continuum are derived and the resonant damping of the slow surface mode under photospheric conditions is investigated. Methods: The connection formula across the resonant layer is used to derive the damping rate for the slow sausage mode in the slow continuum by assuming a thin boundary. Results: It is shown that the effect of the resonant damping on the slow surface sausage mode in the slow continuum, which has been underestimated in previous interpretations, could be efficient under magnetic pore conditions. A simplified analytical formula for the damping rate of slow surface mode in the long wavelength limit is derived. This formula can be useful for a rough estimation of the damping rate due to resonant absorption for observational wave damping.

  16. Slow Movement/Slow University: Critical Engagements. Introduction to the Thematic Section

    Directory of Open Access Journals (Sweden)

    Maggie O'Neill

    2014-09-01

    Full Text Available This thematic section emerged from two seminars that took place at Durham University in England in November 2013 and March 2014 on the possibilities for thinking through what a change movement towards slow might mean for the University. Slow movements have emerged in relation to a number of topics: Slow food, Citta slow and more recently, slow science. What motivated us in the seminars was to explore how far these movements could help us address the acceleration and intensification of work within our own and other universities, and indeed, what new learning, research, philosophies, practices, structures and governance might emerge. This editorial introduction presents the concept of the "slow university" and introduces our critical engagements with slow. The articles presented here interrogate the potentialities, challenges, problems and pitfalls of the slow university in an era of corporate culture and management rationality. URN: http://nbn-resolving.de/urn:nbn:de:0114-fqs1403166

  17. Slow-light vortices in periodic waveguides

    DEFF Research Database (Denmark)

    Sukhorukov, Andrey A.; Ha, Sangwoo; Desyatnikov, Anton S.

    2009-01-01

    We reveal that the reduction of the group velocity of light in periodic waveguides is generically associated with the presence of vortex energy flows. We show that the energy flows are gradually frozen for slow-light at the Brillouin zone edge, whereas vortices persist for slow-light states having...

  18. 49 CFR 236.813 - Speed, slow.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Speed, slow. 236.813 Section 236.813 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Speed, slow. A speed not exceeding 20 miles per hour. ...

  19. Response of electret dosemeter to slow neutrons

    International Nuclear Information System (INIS)

    Ghilardi, A.J.P.; Pela, C.A.; Zimmerman, R.L.

    1987-01-01

    The response of electret dosemeter to slow neutrons exposure is cited, mentioning the preparation and the irradiation of dosemeter with Am-Be source. Some theory considerations about the response of electret dosemeter to slow and fast neutrons are also presented. (C.G.C.) [pt

  20. VERY SLOW SPEED AXIAL MOTION RELUCTANCE MOTOR

    African Journals Online (AJOL)

    Dr Obe

    1984-09-01

    Sep 1, 1984 ... VERY SLOW SPEED AXIAL MOTION RELUCTANCE MOTOR by. L. A. Agu. Electrical Engineering Department. University of Nigeria, Nsukka. ABSTRACT. This paper presents the scheme for a very slow speed linear machine which uses conventional laminations and with which speeds of the same low.

  1. Can fast and slow intelligence be differentiated?

    NARCIS (Netherlands)

    Partchev, I.; de Boeck, P.

    2012-01-01

    Responses to items from an intelligence test may be fast or slow. The research issue dealt with in this paper is whether the intelligence involved in fast correct responses differs in nature from the intelligence involved in slow correct responses. There are two questions related to this issue: 1.

  2. Tandem queue with server slow-down

    NARCIS (Netherlands)

    Miretskiy, D.I.; Scheinhardt, W.R.W.; Mandjes, M.R.H.

    2007-01-01

    We study how rare events happen in the standard two-node tandem Jackson queue and in a generalization, the socalled slow-down network, see [2]. In the latter model the service rate of the first server depends on the number of jobs in the second queue: the first server slows down if the amount of

  3. Connecting slow earthquakes to huge earthquakes.

    Science.gov (United States)

    Obara, Kazushige; Kato, Aitaro

    2016-07-15

    Slow earthquakes are characterized by a wide spectrum of fault slip behaviors and seismic radiation patterns that differ from those of traditional earthquakes. However, slow earthquakes and huge megathrust earthquakes can have common slip mechanisms and are located in neighboring regions of the seismogenic zone. The frequent occurrence of slow earthquakes may help to reveal the physics underlying megathrust events as useful analogs. Slow earthquakes may function as stress meters because of their high sensitivity to stress changes in the seismogenic zone. Episodic stress transfer to megathrust source faults leads to an increased probability of triggering huge earthquakes if the adjacent locked region is critically loaded. Careful and precise monitoring of slow earthquakes may provide new information on the likelihood of impending huge earthquakes. Copyright © 2016, American Association for the Advancement of Science.

  4. Impact of lengthening open water season on food security in Alaska coastal communities: Global impacts may outweigh local "frontline" effects

    Science.gov (United States)

    Rolph, R.; Mahoney, A. R.

    2015-12-01

    Using ice concentration data from the Alaska Sea Ice Atlas from 1953-2013 for selected communities in Alaska, we find a consistent trend toward later freeze up and earlier breakup, leading a lengthened open water period. Such changes are often considered to bring a variety of "frontline" local impacts to Arctic coastal communities such as increased rates of coastal erosion. However, direct consequences of these changes to local food security (e.g. through impacts on subsistence activities and marine transport of goods) may be outweighed at least in the short term by the effects of large scale Arctic sea ice change coupled with global oil markets. For example, a later freeze-up might delay local hunters' transition from boats to snow-machines, but whether this trend will affect hunting success, especially in the next few years, is uncertain. Likewise, the magnitude of change in open water season length is unlikely to be sufficient to increase the frequency with which communities are served by barges. However, an expanding open water season throughout the Arctic has implications for the global economy, which can have indirect effects on local communities. In the Chukchi and Beaufort Seas, where rapid sea ice change has been accompanied by increased interest in oil and gas development, the U.S. Bureau of Ocean Energy Management currently requires drilling operations to cease 38 days prior to freeze up. Taking this into account, the lengthening open water season has effectively extended the drilling season for oil companies by 184% since the 1950s. If oil development goes ahead, local communities will likely experience a range of indirect impacts on food security due to increased vessel traffic and demand on infrastructure coupled with changes in local economies and employment opportunities. Increased likelihood of an oil spill in coastal waters also poses a significant threat to local food security. Thus, while Arctic coastal communities are already experiencing

  5. Accurate and precise determination of 2-25mg amounts of uranium by means of a special automatic potentiometric titration

    International Nuclear Information System (INIS)

    Slanina, J.; Bakker, F.; Groen, A.J.P.; Lingerak, W.A.

    1978-01-01

    A precise and accurate potentiometric titration of 2-25 mg of uranium is described. The uranium is reduced to U(IV) according to the method of Eberle et al. [3], and titrated with 0.05 N potassium dichromate, using a platinum indicator electrode. During the sample preparation the walls of the titration vessel are cleaned by centrifugation. To avoid overshoot of the set point a special differentiator is described, that interrupts the titration until equilibrium is reached. The precision of the method is 0.02%, the accuracy is better than 0.04% rel. Each titration takes 5 min. (orig.) [de

  6. A Computer-Based Simulation of an Acid-Base Titration

    Science.gov (United States)

    Boblick, John M.

    1971-01-01

    Reviews the advantages of computer simulated environments for experiments, referring in particular to acid-base titrations. Includes pre-lab instructions and a sample computer printout of a student's use of an acid-base simulation. Ten references. (PR)

  7. Going Beyond, Going Further: The Preparation of Acid-Base Titration Curves.

    Science.gov (United States)

    McClendon, Michael

    1984-01-01

    Background information, list of materials needed, and procedures used are provided for a simple technique for generating mechanically plotted acid-base titration curves. The method is suitable for second-year high school chemistry students. (JN)

  8. Titration of Alanine Monitored by NMR Spectroscopy: A Biochemistry Laboratory Experiment

    Science.gov (United States)

    Waller, Francis J.; And Others

    1977-01-01

    The experiment described here involves simultaneous monitoring of pH and NMR chemical shifts during an aqueous titration of alpha- and beta-alanine. This experiment is designed for use in an undergraduate biochemistry course. (MR)

  9. Antiepileptic Drug Titration and Related Health Care Resource Use and Costs.

    Science.gov (United States)

    Fishman, Jesse; Kalilani, Linda; Song, Yan; Swallow, Elyse; Wild, Imane

    2018-02-27

    Unexpected breakthrough seizures resulting from suboptimal antiepileptic drug (AED) dosing during the titration period, as well as adverse events resulting from rapid AED titration, may influence the titration schedule and significantly increase health care resource use (HRU) and health care costs. To assess the relationship between AEDs, HRU, and costs during AED titration and maintenance. Practicing neurologists were recruited from a nationwide panel to provide up to 3 patient records each for this retrospective medical chart review. Patients with epilepsy who were aged ≥ 18 years and had initiated an AED between January 1, 2014, and January 1, 2016, were followed for 6 months from AED initiation. Titration duration was the time from AED initiation to the beginning of treatment maintenance as determined by the physician. Outcomes were epilepsy-specific HRU (hospitalizations, emergency department visits, outpatient visits, physician referral, laboratory testing/diagnostic imaging, and phone calls) and related costs that occurred during the titration or maintenance treatment periods. Of 811 patients, 156, 128, 125, 120, 114, 107, and 61 initiated the following AEDs: levetiracetam, lamotrigine, lacosamide, valproate, topiramate, carbamazepine, and phenytoin, respectively. Most patients (619/803 [77.1%] with complete AED data) received monotherapy. Baseline characteristics were similar across AEDs (mean [SD] age, 36.6 [14.4] years; 59.0% male). Kaplan-Meier estimates of titration duration ranged from 3.3 weeks (phenytoin) to 8.1 weeks (lamotrigine). From titration to maintenance, the overall incidence of HRU per person-month decreased 54.5%-89.3% for each HRU measure except outpatient visits (24.6% decrease). Total epilepsy-related costs decreased from $80.48 to $42.77 per person-month, or 46.9% from titration to maintenance. AED titration periods had higher HRU rates and costs than AED maintenance, suggesting that use of AEDs with shorter titration requirements

  10. Comparison of VFA titration procedures used for monitoring the biogas process.

    Science.gov (United States)

    Lützhøft, Hans-Christian Holten; Boe, Kanokwan; Fang, Cheng; Angelidaki, Irini

    2014-05-01

    Titrimetric determination of volatile fatty acids (VFAs) contents is a common way to monitor a biogas process. However, digested manure from co-digestion biogas plants has a complex matrix with high concentrations of interfering components, resulting in varying results when using different titration procedures. Currently, no standardized procedure is used and it is therefore difficult to compare the performance among plants. The aim of this study was to evaluate four titration procedures (for determination of VFA-levels of digested manure samples) and compare results with gas chromatographic (GC) analysis. Two of the procedures are commonly used in biogas plants and two are discussed in literature. The results showed that the optimal titration results were obtained when 40 mL of four times diluted digested manure was gently stirred (200 rpm). Results from samples with different VFA concentrations (1-11 g/L) showed linear correlation between titration results and GC measurements. However, determination of VFA by titration generally overestimated the VFA contents compared with GC measurements when samples had low VFA concentrations, i.e. around 1 g/L. The accuracy of titration increased when samples had high VFA concentrations, i.e. around 5 g/L. It was further found that the studied ionisable interfering components had lowest effect on titration when the sample had high VFA concentration. In contrast, bicarbonate, phosphate and lactate had significant effect on titration accuracy at low VFA concentration. An extended 5-point titration procedure with pH correction was best to handle interferences from bicarbonate, phosphate and lactate at low VFA concentrations. Contrary, the simplest titration procedure with only two pH end-points showed the highest accuracy among all titration procedures at high VFA concentrations. All in all, if the composition of the digested manure sample is not known, the procedure with only two pH end-points should be the procedure of

  11. Microchemical analysis of materials based on Y-Ba-Cu by spectrophotometric titration

    International Nuclear Information System (INIS)

    Kuznetsov, V.V.; Samorukova, O.L.; Zakharov, Eh.K.

    1990-01-01

    A complex method for analysis of superconductor and similar materials on Y-Ba-Cu basis has been developed, which comprises yttrium and copper determination by their indicator spectrophotometric titration by EDTA and/or complexone 4 in the presence of arsenazo 3. The use of complexone 4 is more favourable. Titration is carried out at λ=650 nm. The method has a sufficient accuracy, provides for rapid determination and does not reguire preliminary separation of components

  12. Determination of opium and strychnos alkaloids by radiometric titrations with potassium thallium(I) iodide reagent

    International Nuclear Information System (INIS)

    Rama Rao, V.V.; Singh, N.J.; Tandon, S.N.

    1980-01-01

    The titrations were carried out by the batch method in test tubes, using 204 Tl-labelled potassium thallium(I) iodide as precipitant for alkaloids such as codeine, morphine, narcotine, papaverine, thebaine, strychnine and brucine. Direct and reverse titrations were investigated including sensitivity and accuracy. Codeine and narcotine were determined in some pharmaceutical preparations such as codeine sulfate tablets, codopyrin tablets and coscopin syrup

  13. Pulmonary acute respiratory distress syndrome: positive end-expiratory pressure titration needs stress index.

    Science.gov (United States)

    Huang, Yingzi; Yang, Yi; Chen, Qiuhua; Liu, Songqiao; Liu, Ling; Pan, Chun; Yang, Congshan; Qiu, Haibo

    2013-11-01

    The heterogeneity of lung injury in pulmonary acute respiratory distress syndrome (ARDS) may have contributed to the greater response of hyperinflated area with positive end-expiratory pressure (PEEP). PEEP titrated by stress index can reduce the risk of alveolar hyperinflation in patients with pulmonary ARDS. The authors sought to investigate the effects of PEEP titrated by stress index on lung recruitment and protection after recruitment maneuver (RM) in pulmonary ARDS patients. Thirty patients with pulmonary ARDS were enrolled. After RM, PEEP was randomly set according to stress index, oxygenation, static pulmonary compliance (Cst), or lower inflection point (LIP) + 2 cmH2O strategies. Recruitment volume, gas exchange, respiratory mechanics, and hemodynamic parameters were collected. PEEP titrated by stress index (15.1 ± 1.8 cmH2O) was similar to the levels titrated by oxygenation (14.5 ± 2.9 cmH2O), higher than that titrated by Cst (11.3 ± 2.5 cmH2O) and LIP (12.9 ± 1.6 cmH2O) (P stress index and oxygenation but higher than that titrated by Cst and LIP. Compared with baseline, lung compliance increased significantly when PEEP determined by Cst, but there was no difference of Cst in these four strategies. There was no influence of PEEP titration with the four strategies on hemodynamic parameters. PEEP titration by stress index might be more beneficial for pulmonary ARDS patients after RM. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. Value of routine investigations to predict loop diuretic down-titration success in stable heart failure.

    Science.gov (United States)

    Martens, Pieter; Verbrugge, Frederik H; Boonen, Levinia; Nijst, Petra; Dupont, Matthias; Mullens, Wilfried

    2018-01-01

    Guidelines advocate down-titration of loop diuretics in chronic heart failure (CHF) when patients have no signs of volume overload. Limited data are available on the expected success rate of this practice or how routine diagnostic tests might help steering this process. Fifty ambulatory CHF-patients on stable neurohumoral blocker/diuretic therapy for at least 3months without any clinical sign of volume overload were prospectively included to undergo loop diuretic down-titration. All patients underwent a similar pre-down-titration evaluation consisting of a dyspnea scoring, physical examination, transthoracic echocardiography (diastolic function, right ventricular function, cardiac filling pressures and valvular disease), blood sample (serum creatinine, plasma NT-pro-BNP and neurohormones). Loop diuretic maintenance dose was subsequently reduced by 50% or stopped if dose was ≤40mg furosemide equivalents. Successful down-titration was defined as a persistent dose reduction after 30days without weight increase >1.5kg or new-onset symptoms of worsening heart failure. At 30-day follow-up, down-titration was successful in 62% (n=31). In 12/19 patients exhibiting down-titration failure, this occurred within the first week. Physical examination, transthoracic echocardiography and laboratory analysis had limited predictive capability to detect patients with down-titration success/failure (positive likelihood-ratios below 1.5, or area under the curve [AUC] non-statically different from AUC=0.5). Loop diuretic down-titration is feasible in a majority of stable CHF patients in which the treating clinician felt continuation of loops was unnecessary to sustain euvolemia. Importantly, routine diagnostics which suggest euvolemia, have limited diagnostic impact on the post-test probability. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Determination of the aggregation number for micelles by isothermal titration calorimetry

    DEFF Research Database (Denmark)

    Olesen, Niels Erik; Holm, Rene; Westh, Peter

    2014-01-01

    Isothermal titration calorimetry (ITC) has previously been applied to estimate the aggregation number (n), Gibbs free energy (ΔG), enthalpy (ΔH) and entropy (ΔS) of micellization. However, some difficulties of micelle characterization by ITC still remain; most micelles have aggregation numbers...... insight into optimal design of titration protocols for micelle characterization. By applying the new method, the aggregation number of sodium dodecyl sulphate and glycochenodeoxycholate was determined at concentrations around their critical micelle concentration (CMC)...

  16. Potentiometric titration of zinc and cadmium in electrolytes of in galvanic baths

    International Nuclear Information System (INIS)

    Kosyuga, E.A.; Kalugin, A.A.; Gur'ev, I.A.

    1979-01-01

    The method of potentiometric titration of zinc and cadmium by complexone 3 in electrolytes of galvanic baths using sulphide - silver electrode for determining the finite point of titration is suggested. Copper (2) ions are proposed as indicator ions. The potentiometric determination should be performed at pH=10. The method is verified on model electrolyte solutions and on the electrolyte solutions of operating baths.The technique can be used for automatic control. The time for analysis is 10 minutes

  17. KEK-IMSS Slow Positron Facility

    Science.gov (United States)

    Hyodo, T.; Wada, K.; Yagishita, A.; Kosuge, T.; Saito, Y.; Kurihara, T.; Kikuchi, T.; Shirakawa, A.; Sanami, T.; Ikeda, M.; Ohsawa, S.; Kakihara, K.; Shidara, T.

    2011-12-01

    The Slow Positron Facility at the Institute of Material Structure Science (IMSS) of High Energy Accelerator Research Organization (KEK) is a user dedicated facility with an energy tunable (0.1 - 35 keV) slow positron beam produced by a dedicated 55MeV linac. The present beam line branches have been used for the positronium time-of-flight (Ps-TOF) measurements, the transmission positron microscope (TPM) and the photo-detachment of Ps negative ions (Ps-). During the year 2010, a reflection high-energy positron diffraction (RHEPD) measurement station is going to be installed. The slow positron generator (converter/ moderator) system will be modified to get a higher slow positron intensity, and a new user-friendly beam line power-supply control and vacuum monitoring system is being developed. Another plan for this year is the transfer of a 22Na-based slow positron beam from RIKEN. This machine will be used for the continuous slow positron beam applications and for the orientation training of those who are interested in beginning researches with a slow positron beam.

  18. An aggressive chondroblastoma of the knee treated with resection arthrodesis and limb lengthening using the Ilizarov technique

    Directory of Open Access Journals (Sweden)

    Rakočević Zoran

    2010-07-01

    Full Text Available Abstract This case report describes the management of a 15 year old male with a biologically aggressive chondroblastoma of the knee. Following CT, bone scan, angiography and an open biopsy, the diagnosis was confirmed histologically and immunohistochemically. The patient underwent a 13 cm en-bloc excision of the knee, and knee arthrodesis with simultaneous bone transport using an Ilizarov ring fixator. Following 136 days of bone transport, the patient achieved radiological and clinical bony union after a total frame time of 372 days. He then commenced 50% partial weight-bear in a protective knee brace and gradually worked up to full weight-bearing by 4 months. The patient developed superficial pin tract infections around the k-wires on 2 occasions; these settled with a cephalosporin antibiotic spray and local dressings. At 13 years follow-up there are no signs of disease recurrence or failure at the fusion site. The patient is able to fully weight bear and stand independently on the operated leg. Knee arthrodesis with simultaneous limb-lengthening is an effective treatment modality following en-bloc resection of an aggressive chondroblastoma. The case is discussed with reference to the literature.

  19. HDAC9 regulates the alternative lengthening of telomere (ALT) pathway via the formation of ALT-associated PML bodies.

    Science.gov (United States)

    Jamiruddin, Mohd Raeed; Kaitsuka, Taku; Hakim, Farzana; Fujimura, Atsushi; Wei, Fan-Yan; Saitoh, Hisato; Tomizawa, Kazuhito

    2016-12-02

    Cancer cells overcome cellular senescence by activating the telomere maintenance mechanism, which can be either through telomerase or the alternative lengthening of telomeres (ALT). Being exclusive to cancer cells, targeting ALT is a more promising route for the development of drugs against cancer. The histone deacetylase (HDAC) family plays significant roles in various cellular processes. In addition to the regulation of gene expression, HDACs are also known to directly interact with many proteins. We focused on this family, and found that HDAC9 was up-regulated in ALT-positive cells. In ALT-positive cells treated with HDAC9 siRNA, there was a decrease in the telomere replicative capacity, which was evident from the C-circles assay. Furthermore, the formation of ALT-associated promyelocytic leukemia (PML) nuclear bodies (APBs) was inhibited by HDAC9 knockdown. Based on this study, it is suggested that HDAC9 regulates the formation of APBs and could be a candidate for the target of ALT-cancer therapy. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Children's acquisition of speech timing in English: a comparative study of voice onset time and final syllable vowel lengthening.

    Science.gov (United States)

    Snow, D

    1997-02-01

    This study describes English-speaking children's acquisition of voice onset time (VOT), a segmental feature that specifies the timing of word-initial stop consonants, and final-syllable vowel lengthening (FSVL), a suprasegmental feature that influences the timing of vowels. The purpose of this study was to evaluate two hypotheses about the acquisition of speech timing contrasts; a 'motoric' hypothesis predicting that children would control the vowel duration contrast earlier than the consonantal one (FSVL before VOT), and a 'representation' hypothesis predicting that children would control the contrast represented on the segmental level of linguistic description earlier than the contrast represented on the suprasegmental level (VOT before FSVL). Longitudinal acquisition patterns for both contrasts were compared in ten children between the mean ages of 1;6 and 2;0. The results, indicating that English-speaking children usually acquired VOT before FSVL, are discussed in light of evidence that French-speaking children acquire analogous contrasts in the opposite sequence. The crosslanguage comparisons support limited forms of both the motoric and representation hypotheses. As promising topics for further study, the results also suggested the importance of individual differences, and the variability of timing features in the input.

  1. A model for oxygen conservation associated with titration during pediatric oxygen therapy.

    Directory of Open Access Journals (Sweden)

    Grace Wu

    Full Text Available Continuous oxygen treatment is essential for managing children with hypoxemia, but access to oxygen in low-resource countries remains problematic. Given the high burden of pneumonia in these countries and the fact that flow can be gradually reduced as therapy progresses, oxygen conservation through routine titration warrants exploration.To determine the amount of oxygen saved via titration during oxygen therapy for children with hypoxemic pneumonia.Based on published clinical data, we developed a model of oxygen flow rates needed to manage hypoxemia, assuming recommended flow rate at start of therapy, and comparing total oxygen used with routine titration every 3 minutes or once every 24 hours versus no titration.Titration every 3 minutes or every 24 hours provided oxygen savings estimated at 11.7% ± 5.1% and 8.1% ± 5.1% (average ± standard error of the mean, n = 3, respectively. For every 100 patients, 44 or 30 kiloliters would be saved-equivalent to 733 or 500 hours at 1 liter per minute.Ongoing titration can conserve oxygen, even performed once-daily. While clinical validation is necessary, these findings could provide incentive for the routine use of pulse oximeters for patient management, as well as further development of automated systems.

  2. Titration of strong and weak acids by sequential injection analysis technique.

    Science.gov (United States)

    Maskula, S; Nyman, J; Ivaska, A

    2000-05-31

    A sequential injection analysis (SIA) titration method has been developed for acid-base titrations. Strong and weak acids in different concentration ranges have been titrated with a strong base. The method is based on sequential aspiration of an acidic sample zone and only one zone of the base into a carrier stream of distilled water. On their way to the detector, the sample and the reagent zones are partially mixed due to the dispersion and thereby the base is partially neutralised by the acid. The base zone contains the indicator. An LED-spectrophotometer is used as detector. It senses the colour of the unneutralised base and the signal is recorded as a typical SIA peak. The peak area of the unreacted base was found to be proportional to the logarithm of the acid concentration. Calibration curves with good linearity were obtained for a strong acid in the concentration ranges of 10(-4)-10(-2) and 0.1-3 M. Automatic sample dilution was implemented when sulphuric acid at concentration of 6-13 M was titrated. For a weak acid, i.e. acetic acid, a linear calibration curve was obtained in the range of 3x10(-4)-8x10(-2) M. By changing the volumes of the injected sample and the reagent, different acids as well as different concentration ranges of the acids can be titrated without any other adjustments in the SIA manifold or the titration protocol.

  3. Process monitored spectrophotometric titration coupled with chemometrics for simultaneous determination of mixtures of weak acids.

    Science.gov (United States)

    Liao, Lifu; Yang, Jing; Yuan, Jintao

    2007-05-15

    A new spectrophotometric titration method coupled with chemometrics for the simultaneous determination of mixtures of weak acids has been developed. In this method, the titrant is a mixture of sodium hydroxide and an acid-base indicator, and the indicator is used to monitor the titration process. In a process of titration, both the added volume of titrant and the solution acidity at each titration point can be obtained simultaneously from an absorption spectrum by least square algorithm, and then the concentration of each component in the mixture can be obtained from the titration curves by principal component regression. The method only needs the information of absorbance spectra to obtain the analytical results, and is free of volumetric measurements. The analyses are independent of titration end point and do not need the accurate values of dissociation constants of the indicator and the acids. The method has been applied to the simultaneous determination of the mixtures of benzoic acid and salicylic acid, and the mixtures of phenol, o-chlorophenol and p-chlorophenol with satisfactory results.

  4. Titration of fatty acids solubilized in cationic and anionic micelles. Calorimetry and thermodynamic modeling.

    Science.gov (United States)

    Söderman, Olle; Jönsson, Bengt; Olofsson, Gerd

    2006-02-23

    The electrostatic properties of charged surfactant micelles are investigated through titrations of fatty acid probes solubilized in the micelles. The titration process is followed by means of calorimetric measurements and by determining the pH values as a function of added base. This approach yields a complete thermodynamic description of the titration process. In particular, we find that the process is endothermic at 298 K. This is contrary to the titration of carboxylic acids in water, where DeltaH is approximately 0. To identify the main effect underlying the difference in DeltaH between titration in a micelle and water, a thermodynamic model has been developed which focuses on the transfer properties of charged and uncharged species from bulk water to the surface of a micelle and which incorporates a dielectric discontinuity at the micellar surface. The model relies on the use of the Poisson-Boltzmann equation which is solved using a finite element method. Experimental results and the model calculations imply that the dielectric discontinuity at (or near) the micellar surface plays a major role and hence must be included when analyzing the titration behavior of an acid functionality at the surface of a charged micelle.

  5. Clinical, polysomnographic, and CPAP titration features of obstructive sleep apnea: Mixed versus purely obstructive type.

    Science.gov (United States)

    Lee, Sang-Ahm; Lee, Gha-Hyun; Chung, Yoo-Sam; Kim, Woo Sung

    2015-08-15

    To determine whether obstructive sleep apnea syndrome (OSAS) patients with mixed sleep apnea (MSA) have different clinical, polysomnographic, and continuous positive airway pressure (CPAP) titration findings compared to OSAS patients without MSA. We retrospectively reviewed the records of OSAS patients who had undergone CPAP titration and categorized them into pure-OSA and mixed-OSA groups. Demographic features, daytime sleepiness, and apnea severity were compared between the two groups using univariate and multivariate analyses. CPAP titration findings were also compared between the two groups. One hundred and ninety-five subjects (n=126 pure-OSA; n=69 mixed-OSA) were included in the analysis. Compared to the pure-OSA group, the mixed-OSA group had a higher percentage of males (p=0.003) and a higher body mass index (p=0.044), Epworth Sleepiness Scale score (p=0.028), and apnea-hypopnea index (AHI) (ptitration, and a higher titrated pressure than the pure-OSA group. Severe OSA, older age, male sex, obesity, and daytime sleepiness were related to mixed-OSA. Complex sleep apnea, less optimal titration, and a higher titrated CPAP were also associated with MSA in OSAS patients. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Non-Aqueous Titration Method for Determining Suppressor Concentration in the MCU Next Generation Solvent (NGS)

    International Nuclear Information System (INIS)

    Taylor-Pashow, Kathryn M. L.; Jones, Daniel H.

    2017-01-01

    A non-aqueous titration method has been used for quantifying the suppressor concentration in the MCU solvent hold tank (SHT) monthly samples since the Next Generation Solvent (NGS) was implemented in 2013. The titration method measures the concentration of the NGS suppressor (TiDG) as well as the residual tri-n-octylamine (TOA) that is a carryover from the previous solvent. As the TOA concentration has decreased over time, it has become difficult to resolve the TiDG equivalence point as the TOA equivalence point has moved closer. In recent samples, the TiDG equivalence point could not be resolved, and therefore, the TiDG concentration was determined by subtracting the TOA concentration as measured by semi-volatile organic analysis (SVOA) from the total base concentration as measured by titration. In order to improve the titration method so that the TiDG concentration can be measured directly, without the need for the SVOA data, a new method has been developed that involves spiking of the sample with additional TOA to further separate the two equivalence points in the titration. This method has been demonstrated on four recent SHT samples and comparison to results obtained using the SVOA TOA subtraction method shows good agreement. Therefore, it is recommended that the titration procedure be revised to include the TOA spike addition, and this to become the primary method for quantifying the TiDG.

  7. Home blood pressure monitoring and self-titration of antihypertensive medications: Proposed patient selection criteria.

    Science.gov (United States)

    Hill, James R

    2016-05-01

    Recent studies have demonstrated that home blood pressure monitoring (HBPM), coupled with self-titration of medications is a viable intervention to control hypertension. There are currently no established criteria to evaluate patients for inclusion in such a program. The purpose of this discussion is to propose criteria for determining if a patient is appropriate to participate in a program of HBPM and self-titration. Inclusion criteria for two self-titration trials were examined, and additional factors in clinical practice were identified and discussed. Additional selection criteria were proposed to support the decision to enroll a patient in an antihypertensive self-titration program. Inclusion criteria from self-titration trials provide a reasonable starting point for choosing appropriate patients in clinical practice, but additional research is necessary. Adaptation of these criteria and consideration of the identified factors can be used to develop decision support instruments. Such instruments should be evaluated for effectiveness and reliability prior to use in clinical practice. HBPM combined with self-titration is an effective patient-centered approach for hypertension management. Decision support instruments to determine appropriate patients are necessary for safe and effective use in clinical practice. ©2015 American Association of Nurse Practitioners.

  8. Determination of free acid in U(VI)-Al(III) solution by Gran plot titration

    International Nuclear Information System (INIS)

    Suh, Moo Yul; Lee, Chang Heon; Sohn, Se Chul; Kim, Jung Suk; Kim, Won Ho; Eom, Tae Yoon

    1999-01-01

    The determination method of free acid in spent U-Al nuclear fuel solutions by Gran plot titration was described. Effect of U(VI) and Al(III) on the alkalimetric titration of nitric acid was investigation in oxalate complexing media as well as in noncomplexing media. Positive biases were observed in both titration media when the end-point was estimated by the Gran plot method. It was found that the cause of the bias was U(VI) in the oxalate complexing media, but Al(III) in the noncomplexing media. The relative error was less than 1% in the titration of 0.1 M HNO 3 at a U(VI):Al(III):H + mole ratio of up to 2:12:1 as long as the pH of the oxalate titration media was sustained to be below 5.0 at the beginning of titration. The method was successfully applied to the determination of nitric acid in a solution of HANARO reactor fuel with U:Al mole ratio of 1:6

  9. Non-Aqueous Titration Method for Determining Suppressor Concentration in the MCU Next Generation Solvent (NGS)

    Energy Technology Data Exchange (ETDEWEB)

    Taylor-Pashow, Kathryn M. L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Jones, Daniel H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-10-23

    A non-aqueous titration method has been used for quantifying the suppressor concentration in the MCU solvent hold tank (SHT) monthly samples since the Next Generation Solvent (NGS) was implemented in 2013. The titration method measures the concentration of the NGS suppressor (TiDG) as well as the residual tri-n-octylamine (TOA) that is a carryover from the previous solvent. As the TOA concentration has decreased over time, it has become difficult to resolve the TiDG equivalence point as the TOA equivalence point has moved closer. In recent samples, the TiDG equivalence point could not be resolved, and therefore, the TiDG concentration was determined by subtracting the TOA concentration as measured by semi-volatile organic analysis (SVOA) from the total base concentration as measured by titration. In order to improve the titration method so that the TiDG concentration can be measured directly, without the need for the SVOA data, a new method has been developed that involves spiking of the sample with additional TOA to further separate the two equivalence points in the titration. This method has been demonstrated on four recent SHT samples and comparison to results obtained using the SVOA TOA subtraction method shows good agreement. Therefore, it is recommended that the titration procedure be revised to include the TOA spike addition, and this to become the primary method for quantifying the TiDG.

  10. Investigation of iodine liberation process in redox titration of potassium iodate with sodium thiosulfate

    International Nuclear Information System (INIS)

    Asakai, Toshiaki; Hioki, Akiharu

    2011-01-01

    Potassium iodate is often used as a reference material to standardize a sodium thiosulfate solution which is a familiar titrant for redox titrations. In the standardization, iodine (triiodide) liberated by potassium iodate in an acidic potassium iodide solution is titrated with a sodium thiosulfate solution. The iodine liberation process is significantly affected by the amount of acid, that of potassium iodide added, the waiting time for the liberation, and light; therefore, the process plays a key role for the accuracy of the titration results. Constant-voltage biamperometry with a modified dual platinum-chip electrode was utilized to monitor the amount of liberated iodine under several liberation conditions. Coulometric titration was utilized to determine the concentration of a sodium thiosulfate solution on an absolute basis. Potassium iodate was assayed by gravimetric titration with the sodium thiosulfate solution under several iodine liberation conditions. The liberation process was discussed from the changes in the apparent assay of potassium iodate. The information of the appropriate titration procedure obtained in the present study is useful for any analysts utilizing potassium iodate to standardize a thiosulfate solution.

  11. Spectrophotometric titrations: Application to the determination of some elements in uranium solutions

    International Nuclear Information System (INIS)

    L'Her, M.

    1967-01-01

    The aim of this work is the application of spectrophotometric titrations to the analysis of uranium-containing solutions. We have been led to examine the general principles involved in these titrations, and we give a brief outline of these principles. In the first part we deal therefore with spectrophotometric titrations from a general point of view, examining their fundamental principle, their practical execution as well as the various possibilities of the method. The advantage of the titration are examined, in particular that of lending itself simultaneous determination of two species. The possibility of applying these spectrophotometric titrations to the analysis of uranium-containing solutions is the subject of the second part of this report: the dosage of a few species in uranium (VI) solutions is described. To this second part is added an experimental appendix consisting of a description of the apparatus, as well as of the operational techniques used for certain titrations, in particular those involving solutions containing uranium. (author) [fr

  12. A model for oxygen conservation associated with titration during pediatric oxygen therapy.

    Science.gov (United States)

    Wu, Grace; Wollen, Alec; Himley, Stephen; Austin, Glenn; Delarosa, Jaclyn; Izadnegahdar, Rasa; Ginsburg, Amy Sarah; Zehrung, Darin

    2017-01-01

    Continuous oxygen treatment is essential for managing children with hypoxemia, but access to oxygen in low-resource countries remains problematic. Given the high burden of pneumonia in these countries and the fact that flow can be gradually reduced as therapy progresses, oxygen conservation through routine titration warrants exploration. To determine the amount of oxygen saved via titration during oxygen therapy for children with hypoxemic pneumonia. Based on published clinical data, we developed a model of oxygen flow rates needed to manage hypoxemia, assuming recommended flow rate at start of therapy, and comparing total oxygen used with routine titration every 3 minutes or once every 24 hours versus no titration. Titration every 3 minutes or every 24 hours provided oxygen savings estimated at 11.7% ± 5.1% and 8.1% ± 5.1% (average ± standard error of the mean, n = 3), respectively. For every 100 patients, 44 or 30 kiloliters would be saved-equivalent to 733 or 500 hours at 1 liter per minute. Ongoing titration can conserve oxygen, even performed once-daily. While clinical validation is necessary, these findings could provide incentive for the routine use of pulse oximeters for patient management, as well as further development of automated systems.

  13. The cryogenic source of slow monochromatic positrons

    International Nuclear Information System (INIS)

    Meshkov, I.N.; Pavlov, V.N.; Sidorin, A.O.; Yakovenko, S.L.

    2008-01-01

    The cryogenic source of slow monochromatic positrons based on the 22 Na isotope has been designed and constructed at JINR. Positrons emitted from radioactive source 22 Na have a very broad energy spectrum up to 0.5 MeV. To generate monochromatic beam of slow positrons the solid neon is used as a moderator. The solid neon allows forming slow positron beam of the energy of 1.2 eV at the spectrum width of 1 eV. The efficiency of moderation is 1 % of total positron flux

  14. Slow light vortices in periodic waveguides

    DEFF Research Database (Denmark)

    Sukhorukov, Andrey A.; Ha, Sangwoo; Desyatnikov, Anton S.

    2009-01-01

    We reveal that the reduction of the group velocity of light in periodic waveguides is generically associated with the presence of vortex energy flows. We show that the energy flows are gradually frozen for slow-light at the Brillouin zone edge, whereas vortices persist for slow-light states having...... non-vanishing phase velocity inside the Brillouin zone. We also demonstrate that presence of vortices can be linked to the absence of slow-light at the zone edge, and present calculations illustrating these general results....

  15. Systematic Design of Slow Light Waveguides

    DEFF Research Database (Denmark)

    Wang, Fengwen

    Light can propagate much slower in photonic crystal waveguides and plasmonic waveguides than in vacuum. Slow light propagation in waveguides shows broad prospects in the terabit communication systems. However, it causes severe signal distortions and displays large propagation loss. Moreover...... the same bandwidth. The first optimization formulation is further employed to design slow light metal- dielectric-metal plasmonic waveguides. It is shown that dispersionless slow light propagation is achieved in the optimized plasmonic waveguide. Further study reveals that the loss in metal can...

  16. Dystonia Associated with Idiopathic Slow Orthostatic Tremor

    Directory of Open Access Journals (Sweden)

    Christopher Kobylecki

    2016-02-01

    Full Text Available Background: We aimed to characterize the clinical and electrophysiological features of patients with slow orthostatic tremor.Case Report: The clinical and neurophysiological data of patients referred for lower limb tremor on standing were reviewed. Patients with symptomatic or primary orthostatic tremor were excluded. Eight patients were identified with idiopathic slow 4–8 Hz orthostatic tremor, which was associated with tremor and dystonia in cervical and upper limb musculature. Coherence analysis in two patients showed findings different to those seen in primary orthostatic tremor.Discussion: Slow orthostatic tremor may be associated with dystonia and dystonic tremor.

  17. Use of modified lip repositioning technique associated with esthetic crown lengthening for treatment of excessive gingival display: A case report of multiple etiologies

    Directory of Open Access Journals (Sweden)

    Matheus Bortoluzzi Mantovani

    2016-01-01

    Full Text Available Excessive gingival display during smile can result in compromised esthetics. This study aims to report a case of excessive gingival display with multiple etiologies treated by means of modified lip repositioning technique associated with esthetic crown lengthening. A 23-year-old female patient, with 5-mm gingival display during smile caused by altered passive eruption and hypermobility of the upper lip, underwent the modified lip repositioning technique associated with gingivectomy followed by flap elevation and ostectomy/osteoplasty. Seven months after the second procedure, the patient had her esthetic complaint solved appearing stable in the observation period. The modified lip repositioning technique is an effective procedure employed to reduce gingival display and when associated with esthetic clinical crown lengthening, can appropriately treat cases of gummy smile.

  18. Use of modified lip repositioning technique associated with esthetic crown lengthening for treatment of excessive gingival display: A case report of multiple etiologies

    Science.gov (United States)

    Mantovani, Matheus Bortoluzzi; Souza, Eduardo Clemente; Marson, Fabiano Carlos; Corrêa, Giovani Oliveira; Progiante, Patrícia Saram; Silva, Cléverson Oliveira

    2016-01-01

    Excessive gingival display during smile can result in compromised esthetics. This study aims to report a case of excessive gingival display with multiple etiologies treated by means of modified lip repositioning technique associated with esthetic crown lengthening. A 23-year-old female patient, with 5-mm gingival display during smile caused by altered passive eruption and hypermobility of the upper lip, underwent the modified lip repositioning technique associated with gingivectomy followed by flap elevation and ostectomy/osteoplasty. Seven months after the second procedure, the patient had her esthetic complaint solved appearing stable in the observation period. The modified lip repositioning technique is an effective procedure employed to reduce gingival display and when associated with esthetic clinical crown lengthening, can appropriately treat cases of gummy smile. PMID:27041845

  19. Deletion lengthening at chromosomes 6q and 16q targets multiple tumor suppressor genes and is associated with an increasingly poor prognosis in prostate cancer

    DEFF Research Database (Denmark)

    Kluth, Martina; Jung, Simon; Habib, Omar

    2017-01-01

    317 patients for 6q and 16q deletion length heterogeneity and found that the deletion expanded within 50-60% of 6q and 16q deleted cancers. Taken together, these data suggest continuous "deletion lengthening" as a key mechanism for prostate cancer progression leading to parallel down regulation......Prostate cancer is characterized by recurrent deletions that can considerably vary in size. We hypothesized that large deletions develop from small deletions and that this "deletion lengthening" might have a "per se" carcinogenic role through a combinatorial effect of multiple down regulated genes.......In vitroknockdown of 37 genes located inside the 6q12-q22 deletion region identified 4 genes with additive tumor suppressive effects, further supporting a role of the deletion size for cancer aggressiveness. Employing fluorescencein-situhybridization analysis on prostate cancer tissue microarrays, we determined...

  20. Slow and Fast Light, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — In response to the NASA Small Business Innovation Research (SBIR) Program 2015 Phase I Solicitation S3.08: Slow and Fast Light, Torch Technologies in partnership...

  1. Experimental demonstration of spinor slow light

    Science.gov (United States)

    Lee, Meng-Jung; Ruseckas, Julius; Lee, Chin-Yuan; Kudriašov, Viačeslav; Chang, Kao-Fang; Cho, Hung-Wen; JuzeliÅ«nas, Gediminas; Yu, Ite A.

    2016-03-01

    Over the last decade there has been a continuing interest in slow and stored light based on the electromagnetically induced transparency (EIT) effect, because of their potential applications in quantum information manipulation. However, previous experimental works all dealt with the single-component slow light which cannot be employed as a qubit. In this work, we report the first experimental demonstration of two-component or spinor slow light (SSL) using a double tripod (DT) atom-light coupling scheme. The oscillations between the two components, similar to the Rabi oscillation of a two-level system or a qubit, were observed. Single-photon SSL can be considered as two-color qubits. We experimentally demonstrated a possible application of the DT scheme as quantum memory and quantum rotator for the two-color qubits. This work opens up a new direction in the slow light research.

  2. Slow and fast light in semiconductor waveguides

    DEFF Research Database (Denmark)

    Mørk, Jesper; Hansen, Per Lunnemann; Xue, Weiqi

    2010-01-01

    transparency and coherent population oscillations. While electromagnetically induced transparency has been the most important effect in realizing slowdown effects in atomic gasses, progress has been comparatively slow in semiconductors due to inherent problems of fast dephasing times and inhomogeneous...

  3. Elastic scattering of slow positrons by helium

    International Nuclear Information System (INIS)

    Amusia, M.Ya.; Cherepkov, N.A.; Chernysheva, L.V.; Shapiro, S.G.

    1976-01-01

    The s-, p-, d- and f-wave phaseshifts for elastic scattering of slow positrons by He are calculated using a simplified version of the random phase approximation with exchange, with virtual positronium formation effect taken into account. (author)

  4. Safety and efficacy of botox injection in alleviating post-operative pain and improving quality of life in lower extremity limb lengthening and deformity correction

    Directory of Open Access Journals (Sweden)

    Finley Allen

    2007-09-01

    Full Text Available Abstract Background Distraction osteogenesis is the standard treatment for the management of lower limb length discrepancy of more than 3 cm and bone loss secondary to congenital anomalies, trauma or infection. This technique consists of an osteotomy of the bone to be lengthened, application of an external fixator, followed by gradual and controlled distraction of the bone ends. Although limb lengthening using the Ilizarov distraction osteogenesis principle yields excellent results in most cases, the technique has numerous problems and is not well tolerated by many children. The objective of the current study is to determine if Botulinum Toxin A (BTX-A, which is known to possess both analgesic and paralytic actions, can be used to alleviate post-operative pain and improve the functional outcome of children undergoing distraction osteogenesis. Methods/Design The study design consists of a multi centre, randomized, double-blinded, placebo-controlled trial. Patients between ages 5–21 years requiring limb lengthening or deformity correction using distraction will be recruited from 6 different sites (Shriners Hospital for Children in Montreal, Honolulu, Philadelphia and Portland as well as DuPont Hospital for Children in Wilmington, Delaware and Hospital for Sick Children in Toronto, Ont. Approximately 150 subjects will be recruited over 2 years and will be randomized to either receive 10 units per Kg of BTX-A or normal saline (control group intraoperatively following the surgery. Functional outcome effects will be assessed using pain scores, medication dosages, range of motion, flexibility, strength, mobility function and quality of life of the patient. IRB approval was obtained from all sites and adverse reactions will be monitored vigorously and reported to IRB, FDA and Health Canada. Discussion BTX-A injection has been widely used world wide with no major side effects reported. However, to the best of our knowledge, this is the first time BTX

  5. On the MAF solution of the uniformly lengthening pendulum via change of independent variable in the Bessel’s equation

    Directory of Open Access Journals (Sweden)

    Coşkun Deniz

    Full Text Available Common recipe for the Lengthening Pendulum (LP involves some change of variables to give a relationship with the Bessel’s equation. In this work, semiclassical MAF (Modified Airy Function solution of the LP is being obtained by first transforming the related Bessel’s equation into the normal form via the suggested change of independent variable just as one of our recent work regarding the JWKB solution of the LP in (Deniz, 2017. MAF approximation of the first order Bessel Functions (ν = 1 of both type along with their zeros are being obtained analytically with a very good accuracy as a result of the appropriately chosen associated initial values and they are extended to the neighbouring orders (ν = 0 and 2 by the recursion relations. Although common numerical methods given in the literature require adiabatic LP systems where the lengthening rate is small, MAF solution presented here can safely be used for higher lengthening rates and a criterion for its validity is determined via the use of MAF applicability criterion given in the literature. As a result, the semiclassical MAF method which is normally used for the quantum mechanical and optical waveguide systems is applied to the classical LP system successfully just as our previous work regarding the JWKB solution of the LP. Interestingly, we have very accurate results in the entire domain except for x≈0. PACS: 02.30.Hq, 02.30.Mv, 03.65.Sq, 03.65.-w, 45.05.+x, 45.10.-b, Keywords: Method of Modified Airy Function (MAF, Semiclassical approximation, Linear differential equations, Initial value problems, The lengthening pendulum

  6. Dystrophin restoration therapy improves both the reduced excitability and the force drop induced by lengthening contractions in dystrophic mdx skeletal muscle.

    Science.gov (United States)

    Roy, Pauline; Rau, Fredérique; Ochala, Julien; Messéant, Julien; Fraysse, Bodvael; Lainé, Jeanne; Agbulut, Onnik; Butler-Browne, Gillian; Furling, Denis; Ferry, Arnaud

    2016-01-01

    The greater susceptibility to contraction-induced skeletal muscle injury (fragility) is an important dystrophic feature and tool for testing preclinic dystrophin-based therapies for Duchenne muscular dystrophy. However, how these therapies reduce the muscle fragility is not clear. To address this question, we first determined the event(s) of the excitation-contraction cycle which is/are altered following lengthening (eccentric) contractions in the mdx muscle. We found that the immediate force drop following lengthening contractions, a widely used measure of muscle fragility, was associated with reduced muscle excitability. Moreover, the force drop can be mimicked by an experimental reduction in muscle excitation of uninjured muscle. Furthermore, the force drop was not related to major neuromuscular transmission failure, excitation-contraction uncoupling, and myofibrillar impairment. Secondly, and importantly, the re-expression of functional truncated dystrophin in the muscle of mdx mice using an exon skipping strategy partially prevented the reductions in both force drop and muscle excitability following lengthening contractions. We demonstrated for the first time that (i) the increased susceptibility to contraction-induced muscle injury in mdx mice is mainly attributable to reduced muscle excitability; (ii) dystrophin-based therapy improves fragility of the dystrophic skeletal muscle by preventing reduction in muscle excitability.

  7. Titrated flow versus fixed flow Bubble Nasal CPAP for respiratory distress in preterm neonates.

    Directory of Open Access Journals (Sweden)

    Srinivas eMurki

    2015-10-01

    Full Text Available Background: The clinical effects of a pre-fixed flow of air-oxygen versus a flow titrated according to visible bubbling are not well understood.Objective: To compare the effects of a fixed flow (5 L/min and titrated flow ( flow just enough to ensure bubbling at different set pressures on delivered intra-prong pressure, gas exchange and clinical parameters in preterm infants on bubble CPAP for respiratory distress.Methods: Preterm infants less than 35 weeks gestation on bubble CPAP and less than 96 h of age, were enrolled in this cross over study. They were subjected to 30 minute periods of titrated flow and fixed flow. At the end of both epochs, gas flow rate, set pressure, FiO2, SpO2, Silverman retraction score, respiratory rate , abdominal girth, and blood gases were recorded. The delivered intra-prong pressure was measured by an electronic manometer. Results: Sixty nine recordings were made in 54 infants. For each of the set CPAP pressures (4, 5 and 6 cm H2O, the mean delivered pressure with a fixed flow of 5 L/min was higher than that delivered by the titrated flow. During the fixed flow epoch, the delivered pressure was closer to and higher than the set pressure resulting in higher PaO2 and lower PaCO2 as compared to titrated flow epoch. In the titrated flow period, the delivered pressure was consistently lower than the set pressure. Conclusion: In preterm infants on bubble CPAP with set pressures of 4 to 6 cm H2O, a fixed flow of 5 L/min is more effective than a flow titrated to ensure adequate visible bubbling. It achieves higher delivered pressures, better oxygenation and ventilation.

  8. Titration ELISA as a Method to Determine the Dissociation Constant of Receptor Ligand Interaction.

    Science.gov (United States)

    Eble, Johannes A

    2018-02-15

    The dissociation constant describes the interaction between two partners in the binding equilibrium and is a measure of their affinity. It is a crucial parameter to compare different ligands, e.g., competitive inhibitors, protein isoforms and mutants, for their binding strength to a binding partner. Dissociation constants are determined by plotting concentrations of bound versus free ligand as binding curves. In contrast, titration curves, in which a signal that is proportional to the concentration of bound ligand is plotted against the total concentration of added ligand, are much easier to record. The signal can be detected spectroscopically and by enzyme-linked immunosorbent assay (ELISA). This is exemplified in a protocol for a titration ELISA that measures the binding of the snake venom-derived rhodocetin to its immobilized target domain of α2β1 integrin. Titration ELISAs are versatile and widely used. Any pair of interacting proteins can be used as immobilized receptor and soluble ligand, provided that both proteins are pure, and their concentrations are known. The difficulty so far has been to determine the dissociation constant from a titration curve. In this study, a mathematical function underlying titration curves is introduced. Without any error-prone graphical estimation of a saturation yield, this algorithm allows processing of the raw data (signal intensities at different concentrations of added ligand) directly by mathematical evaluation via non-linear regression. Thus, several titration curves can be recorded simultaneously and transformed into a set of characteristic parameters, among them the dissociation constant and the concentration of binding-active receptor, and they can be evaluated statistically. When combined with this algorithm, titration ELISAs gain the advantage of directly presenting the dissociation constant. Therefore, they may be used more efficiently in the future.

  9. Long-term effects after conversion of biarticular to monoarticular muscles compared with musculotendinous lengthening in children with spastic diplegia.

    Science.gov (United States)

    Dreher, Thomas; Vegvári, Dóra; Wolf, Sebastian L; Klotz, Matthias; Müller, Sebastian; Metaxiotis, Dimitrios; Wenz, Wolfram; Döderlein, Leonhard; Braatz, Frank

    2013-03-01

    Adverse effects such as increased anterior pelvic tilt (APT) are reported after muscle-tendon lengthening (MTL) for the correction of flexed knee gait in cerebral palsy. The conversion of biarticular muscles (CBM) to monoarticular muscles represents an alternative treatment, but only few short-term results have been published, without comparison with MTL. The long-term outcome of 21 diplegic patients treated with CBM in a prospective study was compared with the results in MTL patients in a matched-pair analysis. Standardized clinical examination and three-dimensional gait analysis were done before surgery, 1 year thereafter, and at long-term follow-up a mean of 9.2 years postoperatively. Mean APT increased one year after surgery in both groups. This increase was higher in MTL patients and statistically significant only for this group. Knee flexion at initial contact and minimum knee flexion in stance were significantly decreased in both groups, while in swing the CBM group tended to show more of a decrease in knee flexion but at the cost of reduced peak flexion. Both groups showed deterioration of kinematic knee parameters through to long-term follow-up; the favourable effects of CBM disappeared, and the two groups displayed comparable average pelvic and knee kinematics. Considering individual patterns the prevalence of increased APT was lower in the CBM group 1 year after surgery, indicating that sparing the semitendinosus may have a positive effect on pelvic stability. However, after 9 years 30% of the patients in both groups showed increased APT indicative of persistent hamstring insufficiency. These results demonstrate that CBM, a significantly more extensive procedure, has no long-term advantage over MTL. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. HP1-mediated formation of alternative lengthening of telomeres-associated PML bodies requires HIRA but not ASF1a.

    Directory of Open Access Journals (Sweden)

    Wei-Qin Jiang

    Full Text Available Approximately 10% of cancers use recombination-mediated Alternative Lengthening of Telomeres (ALT instead of telomerase to prevent telomere shortening. A characteristic of cells that utilize ALT is the presence of ALT-associated PML nuclear bodies (APBs containing (TTAGGGn DNA, telomere binding proteins, DNA recombination proteins, and heterochromatin protein 1 (HP1. The function of APBs is unknown and it is possible that they are functionally heterogeneous. Most ALT cells lack functional p53, and restoration of the p53/p21 pathway in these cells results in growth arrest/senescence and a substantial increase in the number of large APBs that is dependent on two HP1 isoforms, HP1α and HP1γ. Here we investigated the mechanism of HP1-mediated APB formation, and found that histone chaperones, HIRA and ASF1a, are present in APBs following activation of the p53/p21 pathway in ALT cells. HIRA and ASF1a were also found to colocalize inside PML bodies in normal fibroblasts approaching senescence, providing evidence for the existence of a senescence-associated ASF1a/HIRA complex inside PML bodies, consistent with a role for these proteins in induction of senescence in both normal and ALT cells. Moreover, knockdown of HIRA but not ASF1a significantly reduced p53-mediated induction of large APBs, with a concomitant reduction of large HP1 foci. We conclude that HIRA, in addition to its physical and functional association with ASF1a, plays a unique, ASF1a-independent role, which is required for the localization of HP1 to PML bodies and thus for APB formation.

  11. Slow force response and auto-regulation of contractility in heterogeneous myocardium.

    Science.gov (United States)

    Markhasin, Vladimir S; Balakin, Alexander A; Katsnelson, Leonid B; Konovalov, Pavel; Lookin, Oleg N; Protsenko, Yuri; Solovyova, Olga

    2012-01-01

    Classically, the slow force response (SFR) of myocardium refers to slowly developing changes in cardiac muscle contractility induced by external mechanical stimuli, e.g. sustained stretch. We present evidence for an intra-myocardial SFR (SFR(IM)), caused by the internal mechanical interactions of muscle segments in heterogeneous myocardium. Here we study isometric contractions of a pair of end-to-end connected functionally heterogeneous cardiac muscles (an in-series muscle duplex). Duplex elements can be either biological muscles (BM), virtual muscles (VM), or a hybrid combination of BM and VM. The VM implements an Ekaterinburg-Oxford mathematical model accounting for the ionic and myofilament mechanisms of excitation-contraction coupling in cardiomyocytes. SFR(IM) is expressed in gradual changes in the overall duplex force and in the individual contractility of each muscle, induced by cyclic auxotonic deformations of coupled muscles. The muscle that undergoes predominant cyclic shortening shows force enhancement upon return to its isometric state in isolation, whereas average cyclic lengthening may decrease the individual muscle contractility. The mechanical responses are accompanied with slow and opposite changes in the shape and duration of both the action potential and Ca²⁺ transient in the cardiomyocytes of interacting muscles. Using the mathematical model we found that the contractility changes in interacting muscles follow the alterations in the sarcoplasmic reticulum loading in cardiomyocytes which result from the length-dependent Ca²⁺ activation of myofilaments and intracellular mechano-electrical feedback. The SFR(IM) phenomena unravel an important mechanism of cardiac functional auto-regulation applicable to the heart in norm and pathology, especially to hearts with severe electrical and/or mechanical dyssynchrony. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. A stable and convenient protein electrophoresis titration device with bubble removing system.

    Science.gov (United States)

    Zhang, Qiang; Fan, Liu-Yin; Li, Wen-Lin; Cong, Feng-Song; Zhong, Ran; Chen, Jing-Jing; He, Yu-Chen; Xiao, Hua; Cao, Cheng-Xi

    2017-07-01

    Moving reaction boundary titration (MRBT) has a potential application to immunoassay and protein content analysis with high selectivity. However, air bubbles often impair the accuracy of MRBT, and the leakage of electrolyte greatly decreases the safety and convenience of electrophoretic titration. Addressing these two issues a reliable MRBT device with modified electrolyte chamber of protein titration was designed. Multiphysics computer simulation was conducted for optimization according to two-phase flow. The single chamber was made of two perpendicular cylinders with different diameters. After placing electrophoretic tube, the resident air in the junction next to the gel could be eliminated by a simple fast electrolyte flow. Removing the electrophoretic tube automatically prevented electrolyte leakage at the junction due to the gravity-induced negative pressure within the chamber. Moreover, the numerical simulation and experiments showed that the improved MRBT device has following advantages: (i) easy and rapid setup of electrophoretic tube within 20 s; (ii) simple and quick bubble dissipates from the chamber of titration within 2 s; (iii) no electrolyte leakage from the two chambers: and (iv) accurate protein titration and safe instrumental operation. The developed technique and apparatus greatly improves the performance of the previous MRBT device, and providing a new route toward practical application. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Using Spectrophotometric Titrations To Characterize Humic Acid Reactivity at Environmental Concentrations

    International Nuclear Information System (INIS)

    Janot, N.; Benedetti, M. F.; Janot, N.; Reiller, P. E.; Korshin, G. V.

    2010-01-01

    Potentiometric titration is a common method to characterize dissolved organic matter (DOM) reactivity. Because of the sensitivity of pH electrodes, it is necessary to work with very high DOM (≥1 g/L) concentrations that are unrealistic compared to those found in natural waters (0. 1 to 100 mg/L). To obtain proton binding data for concentrations closer to environmental values, spectroscopic titration methodology is a viable alternative to traditional potentiometric titrations. Spectrophotometric titrations and UV visible spectra of a diluted solution of purified Aldrich humic acid (5 mg(DOC)/L) are used to estimate changes in proton binding moieties as function of pH and ionic strength after calculation of differential absorbance spectra variations. After electrostatic correction of spectrophotometric data, there is a linear operational correlation between spectrophotometric and potentiometric data which can be used as a transfer function between the two properties. Spectrophotometric titrations are then used to determine the changes of humic acid protonation after adsorption onto alpha-alumina. (authors)

  14. The Mobile Insulin Titration Intervention (MITI) for Insulin Glargine Titration in an Urban, Low-Income Population: Randomized Controlled Trial Protocol.

    Science.gov (United States)

    Levy, Natalie; Moynihan, Victoria; Nilo, Annielyn; Singer, Karyn; Bernik, Lidia S; Etiebet, Mary-Ann; Fang, Yixin; Cho, James; Natarajan, Sundar

    2015-03-13

    Patients on insulin glargine typically visit a clinician to obtain advice on how to adjust their insulin dose. These multiple clinic visits can be costly and time-consuming, particularly for low-income patients. It may be feasible to achieve insulin titration through text messages and phone calls with patients instead of face-to-face clinic visits. The objectives of this study are to (1) evaluate if the Mobile Insulin Titration Intervention (MITI) is clinically effective by helping patients reach their optimal dose of insulin glargine, (2) determine if the intervention is feasible within the setting and population, (3) assess patient satisfaction with the intervention, and (4) measure the costs associated with this intervention. This is a pilot study evaluating an approach to insulin titration using text messages and phone calls among patients with insulin-dependent type 2 diabetes in the outpatient medical clinic of Bellevue Hospital Center, a safety-net hospital in New York City. Patients will be randomized in a 1:1 ratio to either the MITI arm (texting/phone call intervention) or the usual-care arm (in-person clinic visits). Using a Web-based platform, weekday text messages will be sent to patients in the MITI arm, asking them to text back their fasting blood glucose values. In addition to daily reviews for alarm values, a clinician will rereview the texted values weekly, consult our physician-approved titration algorithm, and call the patients with advice on how to adjust their insulin dose. The primary outcome will be whether or not a patient reaches his/her optimal dose of insulin glargine within 12 weeks. Recruitment for this study occurred between June 2013 and December 2014. We are continuing to collect intervention and follow-up data from our patients who are currently enrolled. The results of our data analysis are expected to be available in 2015. This study explores the use of widely-available text messaging and voice technologies for insulin titration

  15. Kinetics of bacterial potentiometric titrations : the effect of equilibration time on buffering capacity of Pantoea agglomerans suspensions

    OpenAIRE

    Kapetas, Leon; Ngwenya, Bryne T.; MacDonald, Alan M.; Elphick, Stephen C.

    2011-01-01

    Several recent studies have made use of continuous acid–base titration data to describe the surface chemistry of bacterial cells as a basis for accurately modelling metal adsorption to bacteria and other biomaterials of potential industrial importance. These studies do not share a common protocol; rather they titrate in different pH ranges and they use different stability criteria to define equilibration time during titration. In the present study we investigate the kinetics of bacterial titr...

  16. Human gamma oscillations during slow wave sleep.

    Directory of Open Access Journals (Sweden)

    Mario Valderrama

    Full Text Available Neocortical local field potentials have shown that gamma oscillations occur spontaneously during slow-wave sleep (SWS. At the macroscopic EEG level in the human brain, no evidences were reported so far. In this study, by using simultaneous scalp and intracranial EEG recordings in 20 epileptic subjects, we examined gamma oscillations in cerebral cortex during SWS. We report that gamma oscillations in low (30-50 Hz and high (60-120 Hz frequency bands recurrently emerged in all investigated regions and their amplitudes coincided with specific phases of the cortical slow wave. In most of the cases, multiple oscillatory bursts in different frequency bands from 30 to 120 Hz were correlated with positive peaks of scalp slow waves ("IN-phase" pattern, confirming previous animal findings. In addition, we report another gamma pattern that appears preferentially during the negative phase of the slow wave ("ANTI-phase" pattern. This new pattern presented dominant peaks in the high gamma range and was preferentially expressed in the temporal cortex. Finally, we found that the spatial coherence between cortical sites exhibiting gamma activities was local and fell off quickly when computed between distant sites. Overall, these results provide the first human evidences that gamma oscillations can be observed in macroscopic EEG recordings during sleep. They support the concept that these high-frequency activities might be associated with phasic increases of neural activity during slow oscillations. Such patterned activity in the sleeping brain could play a role in off-line processing of cortical networks.

  17. Magnon Inflation: Slow Roll with Steep Potentials

    CERN Document Server

    Adshead, Peter; Burgess, C P; Hayman, Peter; Patil, Subodh P

    2016-01-01

    We find multi-scalar effective field theories (EFTs) that can achieve a slow inflationary roll despite having a scalar potential that does not satisfy the usual slow-roll condition (d V)^2 << V^2/Mp^2. They evade the usual slow-roll conditions on $V$ because their kinetic energies are dominated by single-derivative terms rather than the usual two-derivative terms. Single derivatives dominate during slow roll and so do not require a breakdown of the usual derivative expansion that underpins calculational control in much of cosmology. The presence of such terms requires some sort of UV Lorentz-symmetry breaking during inflation (besides the usual cosmological breaking). Chromo-natural inflation provides an example of a UV theory that can generate the multi-field single-derivative terms we consider, and we argue that the EFT we find indeed captures the slow-roll conditions for the background evolution for Chromo-natural inflation. We also show that our EFT can be understood as a multi-field generalization ...

  18. Effect of Intensive Atropine Doses (Rapid Incremental Loading and Titration for Management of Organophosphorus Pesticide Poisoning: a Case Series

    Directory of Open Access Journals (Sweden)

    Abu Saleh Ahmed

    2014-03-01

    Full Text Available Background:Acute poisoning with organophosphorus (OP pesticides is a common method of suicide and entails considerable mortality in Bangladesh. The objective of this study was to evaluate the effects and outcomes of a protocol for treatment of OP poisoning that included titrated incremental atropine as loading dose and slow infusion for maintenance.  Methods:In this prospective descriptive case series, definitive OP poisoned patients were enrolled in an adult medicine unit of Dhaka Medical College Hospital from April 2006 to April 2007. Clinical examinations were done as soon as the patient entered the ward. Patient’s demographics, comorbid conditions and the occurrence of specific clinical outcomes including death, need for assisted ventilation and clinical complications were recorded. The patients were treated according to the protocol. Results: A total of 56 patients were enrolled over the study period. The median age of the study population was 22.5 years. Most patients were men (67.8%. The most common clinical presentation was miosis (58.9%. In total, 11 patients died (19.6%. Intermediate syndrome developed in 12 patients (21.4% and 6 of them died. Assisted ventilation was required in 16 cases (28.5. Patients with diastolic blood pressure ≤ 70 mmHg and/or GCS ≤ 10 were significantly less likely to survive (P = 0.02, 0.006, respectively. Moreover, early respiratory failure (P < 0.001 and the need for assisted ventilation (P < 0.001 were significantly higher among deceased cases. The mortality rate in this study was similar to previous studies. The frequency of atropine toxicity in the present study (1.8% was considerably lower than conventional regimen used in previous studies. Conclusion:Using the new protocol, lower rate of atropine toxicity developed in victims. Hence, the new protocol appears to be safer and its effectiveness should be further evaluated in case control studies in Bangladesh.    How to cite this article: Ahmed AS

  19. Online Automatic Titration of Chromic Acid in Chromium Plating Solutions and Phosphoric and Sulfuric Acids in Electropolishing Solutions

    National Research Council Canada - National Science Library

    Sopok, Samuel

    1991-01-01

    .... The analytical chemistry literature lacks an adequate online automatic titration method for the monitoring of chromic acid in chromium plating solutions and the monitoring of phosphoric and sulfuric...

  20. Linear titration plot for the determination of boron in the primary coolant of a pressurized water reactor

    International Nuclear Information System (INIS)

    Midgley, D.; Gatford, C.

    1992-01-01

    A linear titration plot method has been devised for the determination of boron as boric acid in partly neutralized solution, such as occurs in the primary coolant of pressurized water reactors. The total boron and the alkali in the sample are determined simultaneously. Although it is not essential to add mannitol in this method, it is more accurate when the solution is saturated with mannitol. Comparisons are made with other modes of titration: Gran plots, first and second differential potentiometric titrations and indicator titrations. None of these gives the total boron directly in partly neutralized solutions. (author)

  1. Belief Propagation for Probabilistic Slow Feature Analysis

    Science.gov (United States)

    Omori, Toshiaki; Sekiguchi, Tomoki; Okada, Masato

    2017-08-01

    Slow feature analysis (SFA) is a time-series analysis method for extracting slowly-varying latent features from multi-dimensional data. A recent study proposed a probabilistic framework of SFA using the Bayesian statistical framework. However, the conventional probabilistic framework of SFA can not accurately extract the slow feature in noisy environments since its marginal likelihood function was approximately derived under the assumption that there exists no observation noise. In this paper, we propose a probabilistic framework of SFA with rigorously derived marginal likelihood function. Here, we rigorously derive the marginal likelihood function of the probabilistic framework of SFA by using belief propagation. We show using numerical data that the proposed probabilistic framework of SFA can accurately extract the slow feature and underlying parameters for the latent dynamics simultaneously even under noisy environments.

  2. Kinetic slow mode-type solitons

    Directory of Open Access Journals (Sweden)

    K. Baumgärtel

    2005-01-01

    Full Text Available One-dimensional hybrid code simulations are presented, carried out in order both to study solitary waves of the slow mode branch in an isotropic, collisionless, medium-β plasma (βi=0.25 and to test the fluid based soliton interpretation of Cluster observed strong magnetic depressions (Stasiewicz et al., 2003; Stasiewicz, 2004 against kinetic theory. In the simulations, a variety of strongly oblique, large amplitude, solitons are seen, including solitons with Alfvenic polarization, similar to those predicted by the Hall-MHD theory, and robust, almost non-propagating, solitary structures of slow magnetosonic type with strong magnetic field depressions and perpendicular ion heating, which have no counterpart in fluid theory. The results support the soliton-based interpretation of the Cluster observations, but reveal substantial deficiencies of Hall-MHD theory in describing slow mode-type solitons in a plasma of moderate beta.

  3. Potentiometric Measurement of Transition Ranges and Titration Errors for Acid/Base Indicators

    Science.gov (United States)

    Flowers, Paul A.

    1997-07-01

    Sophomore analytical chemistry courses typically devote a substantial amount of lecture time to acid/base equilibrium theory, and usually include at least one laboratory project employing potentiometric titrations. In an effort to provide students a laboratory experience that more directly supports their classroom discussions on this important topic, an experiment involving potentiometric measurement of transition ranges and titration errors for common acid/base indicators has been developed. The pH and visually-assessed color of a millimolar strong acid/base system are monitored as a function of added titrant volume, and the resultant data plotted to permit determination of the indicator's transition range and associated titration error. Student response is typically quite positive, and the measured quantities correlate reasonably well to literature values.

  4. An on-line potentiometric sequential injection titration process analyser for the determination of acetic acid.

    Science.gov (United States)

    van Staden, J F; Mashamba, Mulalo G; Stefan, Raluca I

    2002-09-01

    An on-line potentiometric sequential injection titration process analyser for the determination of acetic acid is proposed. A solution of 0.1 mol L(-1) sodium chloride is used as carrier. Titration is achieved by aspirating acetic acid samples between two strong base-zone volumes into a holding coil and by channelling the stack of well-defined zones with flow reversal through a reaction coil to a potentiometric sensor where the peak widths were measured. A linear relationship between peak width and logarithm of the acid concentration was obtained in the range 1-9 g/100 mL. Vinegar samples were analysed without any sample pre-treatment. The method has a relative standard deviation of 0.4% with a sample frequency of 28 samples per hour. The results revealed good agreement between the proposed sequential injection and an automated batch titration method.

  5. Comparing the Titrations of Mixed-Acid Solutions Using Dropwise and Constant-Flow Techniques

    Science.gov (United States)

    Charlesworth, Paul; Seguin, Matthew J.; Chesney, David J.

    2003-11-01

    A mixed-acid solution containing hydrochloric and phosphoric acids was used to determine the error associated with performing a real-time titration. The results were compared against those obtained by performing the titration in a more traditional dropwise addition of titrant near the equivalence points. It was found that the real-time techniques resulted in significantly decreased analysis times while maintaining a low experimental error. The constant-flow techniques were implemented into two different levels of chemistry. It was found that students could successfully utilize the modified experiments. Problems associated with the techniques, major sources of error, and their solutions are discussed. In both cases, the use of the constant-flow setup has increased student recollection of key concepts, such as pKa determination, proper indicator choice, and recognizing the shape of specific titration curves by increasing student interest in the experiment.

  6. Titration of intravenous synthetic oxytocin post vaginal birth following induction or augmentation.

    Science.gov (United States)

    Lewis, Lucy; Hauck, Yvonne L; Pemberton, Alissa; Crichton, Caroline; Conwell, Marion

    2016-10-01

    Evidence exists for titration of intravenous oxytocin during induction and augmentation, whereas no evidence was identified for titration of intravenous oxytocin following vaginal birth, where management excluded oxytocin for postpartum haemorrhage (PPH). This retrospective cohort study explored this issue through patient case notes and computerised perinatal data. Analysis included 335 women comparing induction (n = 226, 67%) to augmentation (n = 109, 33%). The two groups differed in terms of: parity; oxytocin dosage; length of time on intravenous oxytocin; and the length of first and second stage labour. They had similar rates of PPH and titration of intravenous oxytocin following birth was rarely recorded. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Potentiometric titration of Co(II) in presence of Co(III).

    Science.gov (United States)

    Norkus, E

    1998-12-01

    A potentiometric titration for cobalt(II) determination in the presence of Co(III) based on the oxidation of Co(II) with Na(2)CrO(4) in ethylenediamine medium and back-titration of the oxidant excess with (NH(4))(2)Fe(SO(4))(2) in acid medium is described. The titration is monitored with a Pt indicator electrode and carried out until the greatest jump of potential from one drop of titrant appears. A RSD smaller than 1.5% has been obtained for 50-300 mumol Co(II). The method proposed was applied in the analysis of a new type electroless copper plating solutions containing Co(II)-ethylenediamine complex compounds as reducing agents. Cu(II), Co(III) and Cr(III) do not interfere in the determination of Co(II).

  8. Thermometric titration of a free acid and of uranyl in spent fuel element solutions

    International Nuclear Information System (INIS)

    Zamek, M.; Strafelda, F.

    1975-01-01

    A method was elaborated of determining nitric acid in the presence of uranyl nitrate in both aqueous and non-aqueous solutions using a pyridine aqueous solution as a titration agent, and of determining excess uranyl after a hydrogen peroxide addition by a further titration using the same agent. Even a hundred-fold excess of magnesium did not disturb the titration. The method is used in operating solution analyses in the extraction fuel reprocessing in the presence of a small amount of plutonium and of fission products. The reproducibility and accuracy of the method varied in the order of tens to units per cent depending on the concentration of components to be determined. The procedure is applicable for test volumes ranging between 0.1 and 10 ml in concentrations of 1 to 10 -3 M. (author)

  9. [Research on determination of chemical purity of andrographolide by coulometric titration method].

    Science.gov (United States)

    Yang, Ning; Yang, Dezhi; Xu, Lishen; Lv, Yang

    2010-04-01

    The determination of chemical purity of andrographolide by coulometric titration method is studied in this paper. The coulometric titration was carried out in a mixture composed of 4 mol x L(-1) hydrochloric acid and 1 mol x L(-1) potassium bromide solution and 1 mol x L(-1) potassium nitrate solution (1:1). Bromine is electrogenerated at the anode and reacts with the andrographolide. The number of electrons involved in the eleatrode reaction is 2. Purity of andrographolide is 99.76% compared with 99.77% utilizing area normalization method by HPLC. The RSD are 0.33% and 0.02% respectively. The results from two methods are consistent, so the determination of chemical purity of andrographolide by coulometric titration method is scientific and feasible. The method is rapid, simple, convenient, sensitive and accurate. The reference material is not essential in the method. The method is suitable for determination of chemical purity of andrographolide.

  10. Potentiometric titrations of para and nitro substituted aromatic acids and their mixtures in methylethyl ketone

    International Nuclear Information System (INIS)

    Ozeroglu, C.; Karahan, M.

    2011-01-01

    In this study, it was the purpose to examine the potentiometric titrations of para and nitro substituted aromatic acids in methylethyl ketone (MEK) as a non-aqueous solvent. Good analytical results were obtained in determining the amount of each acid and the amounts of acids in their ternary mixtures by using 0.0964 N tetrabuthylammoniumhydroxyde (TBAH) as a standard titrant. Methylethyl ketone (MEK) which is a good solvent for many organic compounds and has a convenient liquid range of -86 to 80 deg. C was used for titration of the para and nitro substituted aromatic acids. A linear relationship has been found between pKa values of the para and nitro substituted aromatic acids in water and the half neutralization potential (HNP) values determined by potentiometric titration curves of the same acids in MEK. (author)

  11. Oxygen titration in sodium. The mercury method and its use for very low values

    International Nuclear Information System (INIS)

    Champeix, L.; Darras, R.; Duflo, J.

    1958-01-01

    The mercury method for the oxygen titration in sodium has now been known for ten years and is probably the more frequently used. In this text, precision are given to what extent it is valuable when used in microanalysis. Details are given on the apparatus, its manipulation and its calibration. After testing, we have decided to use flame spectroscopy to titrate the sodium hydroxide formed. Discussions are exposed on the errors due to the presence of sodium chloride and calcium. Results are examined from the point of view of their reproducibility and accuracy. If great care is taken, this method allows oxygen titration in sodium even for values below 10 ppm with satisfactory precision. (author) [fr

  12. High frequency titration in non-aqueous solvents. Application to HF and UF6

    International Nuclear Information System (INIS)

    Neveu, Claude

    1965-01-01

    In this research thesis, the author first presents the main theoretical notions regarding high frequency titration, notably by studying characteristic curves, i.e. the titration meter indication with respect to conductibility. He reports the use of this method for the study of various reactions in non-aqueous medium: reaction of AlCl 3 with pyridine in acetonitrile, of AlCl 3 with HCl in tetrachloroethane and in nitromethane. He also reports the attempt of application of this method to the titration of HF in presence of UF 6 in CCl 4 as solvent, or by using F acceptors like BF 3 , PF 5 or ClF 3 as reactants [fr

  13. Transplanckian energy production and slow roll inflation

    International Nuclear Information System (INIS)

    Danielsson, Ulf H.

    2005-01-01

    In this paper we investigate how the energy density due to a nonstandard choice of initial vacuum affects the expansion of the universe during inflation. To do this we introduce source terms in the Friedmann equations making sure that we respect the relation between gravity and thermodynamics. We find that the energy production automatically implies a slow rolling cosmological constant. Hence we also conclude that there is no well defined value for the cosmological constant in the presence of sources. We speculate that a nonstandard vacuum can provide slow roll inflation on its own

  14. Clinical Outcomes of Continuation of Metformin Titration Instructions with Electronic Prescribing.

    Science.gov (United States)

    Delate, Thomas; Rader, Nathan; Rawlings, Julia E; Smith, Karen; Herner, Sheryl J

    2015-06-01

    Anecdotal evidence suggests that metformin titration instructions are not being updated and refill requests are approved without modification of the titration instructions such that the titration instructions is continued for patients newly initiated on metformin. This was a retrospective cohort analysis of adult patients who received newly initiated metformin pharmacotherapy. Patients were followed from their initial metformin purchase through two subsequent metformin refill purchases. Outcomes, including the 3-year incidence rate of patients with at least one set of continued titration instructions and proportions of patients with at least one gastrointestinal adverse effect (AE) and those with an elevated glucose measurement at follow-up, were assessed during the time period between patients' second and third metformin purchases. Analyses were performed comparing the exposure (i.e., patients with continued instructions) group to the control (i.e., patients without continued instructions) group. The exposure group had a higher mean age and chronic disease score but lower metformin starting dose than the control group (all p titration instructions was 60.3 % (95 % CI 58.3-62.3). Gastrointestinal AEs were rare with equivalent proportions of patients in each group experiencing an event (p > 0.05). Control patients (48.7 % of patients with a measurement) were more likely to have had poorly controlled glucose than exposure patients (35.7 % of patients with a measurement) (p titration instructions for patients newly initiated on metformin was observed; however, such continuation did not negatively affect clinical outcomes.

  15. Determination of the protonation enthalpy of humic acid by calorimetric titration technique

    International Nuclear Information System (INIS)

    Kimuro, Shingo; Kirishima, Akira; Sato, Nobuaki

    2015-01-01

    Graphical abstract: The thermodynamic quantities of protonation of humic acid were determined by the combination of potentiometric titration and calorimetric titration. It was observed that the protonation enthalpy and Gibbs free energy had been affected by pH of solution. As a result, the thermodynamics of the protonation reaction of humic acid is influenced by the polyelectrolyte effect and the heterogeneity. - Highlights: • We applied calorimetric titration technique to the protonation of humic acid. • The thermodynamic quantities of protonation of humic acid were determined. • The protonation enthalpy of humic acid is affected by the heterogeneity. • Gibbs free energy of the protonation is affected by the polyelectrolyte effect. - Abstract: In this study, the calorimetric titration technique was used to determine the protonation enthalpy of two reference humic acids and polyacrylic acid. First, we obtained the apparent protonation constant of two kinds of humic acid purchased from IHSS (International Humic Substances Society) and polyacrylic acid by potentiometric titration. Second, we obtained the protonation enthalpy of them by calorimetric titration. The protonation enthalpy of humic acid was affected by pH and the ionic strength of bulk solution. From the comparison of ΔH between humic acid and polyacrylic acid, it was concluded that the pH dependence of ΔH is attributed to the heterogeneity of humic acid. And ΔH of phenolic hydroxyl group in humic acid is strongly influenced by the electric double layer of humic acid’s surface. This is considered to be a reason of the ionic strength dependence of ΔH. On the other hand, Gibbs free energy of the protonation of humic acid is affected by the electrostatic attraction with the progress of dissociation of functional groups such as carboxyl group and phenolic hydroxyl group. Consequently, the thermodynamics of the protonation of humic acid is affected by the polyelectrolyte effect and the

  16. Down-titration of biologics for the treatment of rheumatoid arthritis: a systematic literature review.

    Science.gov (United States)

    Lau, Chak Sing; Gibofsky, Allan; Damjanov, Nemanja; Lula, Sadiq; Marshall, Lisa; Jones, Heather; Emery, Paul

    2017-11-01

    Biologic therapies have improved the management of rheumatoid arthritis (RA) and the treat-to-target approach has resulted in many patients achieving remission. In the current treatment landscape, clinicians have begun considering dose reduction/tapering for their patients. Rheumatology guidelines in Asia, Europe, and the United States include down-titration of biologics but admit that the level of evidence is moderate. We conducted a systematic literature review to assess the published studies that evaluate down-titration of biologics in RA. The published literature was searched for studies that down-titrated the following biologics: abatacept, adalimumab, certolizumab, etanercept, golimumab, infliximab, rituximab, and tocilizumab. Eligible studies included randomized controlled trials (RCTs), non-RCTs, observational, and pharmacoeconomic studies. The outcomes of interest were (1) efficacy and health-related quality of life, (2) disease flares, and (3) impact on cost. Eleven full-text publications were identified; only three were RCTs. Study results suggest that dosing down may be an option in many patients who have achieved remission or low disease activity. However, some patients are likely to experience a disease flare. Across the studies, the definition of disease flare and the down-titration criteria were inconsistent, making it difficult to conclude which patients may be appropriate and when to attempt down-titration. Studies have evaluated the practice of dosing down biologic therapy in patients with RA; however, a relatively small number of RCTs have been published. Although down-titration may be an option for some patients in LDA or remission, additional RCTs are needed to provide guidance on this practice.

  17. Determination of acid–base properties of HCl acid activated palygorskite by Potentiometrie titration

    OpenAIRE

    N. FriniSrasra; E.Srasra

    2008-01-01

    The surface acidity of raw and acid activated palygorskite clay were studied by acid-base potentiometric titration. The Gran plot method was applied for the hydroxide titration and the total surface site (Hs) and the average number of protons reacted per surface site (Z) of palygorskite samples at a given ionic strength were calculated. Acid treatment increases the clay acidity and modifies its surface charge. The point of zero charge value, determined by the common crossing point of Z vs pH ...

  18. Lacosamide and sodium channel-blocking antiepileptic drug cross-titration against levetiracetam background therapy.

    Science.gov (United States)

    Baulac, M; Byrnes, W; Williams, P; Borghs, S; Webster, E; De Backer, M; Dedeken, P

    2017-04-01

    To assess prospectively the effectiveness of lacosamide (LCM) added to levetiracetam (LEV) after down-titration of a concomitant sodium channel blocker (SCB) among patients with focal epilepsy not adequately controlled on LEV and SCB. In this open-label trial, LCM was initiated at 100 mg/day and up-titrated to 200-600 mg/day over 9 weeks; SCB down-titration started when LCM dose reached 200 mg/day. Patients remained on stable LCM/LEV doses for 12 weeks' maintenance (21-week treatment period). The primary outcome was retention rate on LCM. Due to recruitment challenges, fewer than the planned 300 patients participated in the trial, resulting in the trial being underpowered. Overall, 120 patients (mean age 39.7 years) started and 93 completed the trial. The most frequently used SCBs were lamotrigine (39.2%), carbamazepine (30.8%) and oxcarbazepine (27.5%). Eighty-four patients adhered to protocol and discontinued their SCB after cross-titration, but there was insufficient evidence for 36 patients. Retention rate was 73.3% (88/120) for all patients and 83.3% (70/84) for those with evidence of SCB discontinuation. Seizure freedom for patients completing maintenance was 14.0% (13/93). Discontinuation due to adverse events (6.7%) and lack of efficacy (3.3%) occurred primarily during cross-titration. Most frequently reported adverse events during treatment were dizziness (23.3%), headache (15.0%) and fatigue (8.3%). In patients with uncontrolled seizures on LEV/SCB, the LCM/LEV combination appeared to be effective and well tolerated. A cross-titration schedule-flexible LCM up-titration, concomitant SCB down-titration and stable background LEV-could present a feasible and practical approach to initiating LCM while minimizing pharmacodynamic interactions with a SCB. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. Selective two-step titration of thorium by sulfate displacement of the diethylenetriaminepentaacetic acid complex

    International Nuclear Information System (INIS)

    Kiefer, P.

    1980-07-01

    Thorium and other metals are complexed with excess diethylenetriaminepentaacetic acid (DTPA) at pH 1.4, the excess DTPA is titrated with Bi(III) to a xylenol orange end point, sulfate is added to complex Th(IV), and the displaced DTPA again is titrated with Bi(III). Of 61 metal ions and nonmetal anions tested, only Ga(III), Sc(III), tungstate, citrate, oxalate, and thiosulfate interfere seriously. Lesser interferences are In(III), Zr(IV), V(IV), and permanganate. The standard deviation is 2 μg for 56 to 840 μg Th

  20. Higher Order Inclusion Complexes and Secondary Interactions Studied by Global Analysis of Calorimetric Titrations

    DEFF Research Database (Denmark)

    Schönbeck, Jens Christian Sidney; Holm, René; Westh, Peter

    2012-01-01

    This paper investigates the use of isothermal titration calorimetry (ITC) as a tool for studying molecular systems in which weaker secondary interactions are present in addition to a dominant primary interaction. Such systems are challenging since the signal pertaining to the stronger primary......). The results are validated by a 13C NMR titration and negative controls with a bile salt with no secondary binding site (glycocholate) (K = 2.96 ± 0.01 × 103 M–1). The method proved useful for detailed analysis of ITC data and may strengthen its use as a tool for studying molecular systems by advanced binding...

  1. Complexometric consequent titration of bismuth-titanium mixtures in the μg-region

    International Nuclear Information System (INIS)

    Schaefer, H.

    1975-01-01

    A quantitative method is described for the determination of microquantities of bismuth and titanium. Both metals are determined complexometrically with EDTA and potentiometric equivalence point indication using a Cu-ion sensitive electrode in a consequent titration. The analysis is conducted as back-titration with standard Cu-solution. The relative error of the determination is 0.8% for bismuth (50-100 μg) and for titanium (10-30 μg) at 1.0%. Under the chosen conditions, it is possible to determine as little as 15 μg bismuth and 5 μg titanium by means of this procedure. (author)

  2. Comparison of Titration ICP and XRF Spectrometry Methods in Determination of Cerium in Lens Polishing Powder

    International Nuclear Information System (INIS)

    Ninlaphruk, Sumalee; Pichestapong, Pipat; Mungpayabal, Harinate; Jiyavaranant, Thitima; Srisukho, Supapan; Chaisai, Prapassurn

    2004-10-01

    Three analytical methods in determination of cerium in cerium oxide separated from monazite ore for producing lens polishing powder were compared. These methods are titration ICP and XRF spectrometry techniques. The cerium oxide sample with estimated 45% cerium content needed to be digested and converted into solution before the analysis. The analytical results shown significantly no difference between each method. However, the titration method was found to be more convenient and suitable for quality control in the production of cerium oxide as it does not require standard cerium and the complicated analytical instruments

  3. Determination of fluoride ions in water by condutometric titration with lanthanum nitrates

    International Nuclear Information System (INIS)

    Alves, J.C.

    1986-01-01

    An alternative method for determining fluoride ions in drinking water by condutometric titration using La(NO 3 ) 3 as titrant is presented. The method is based on previous separation of fluoride from sample by distillation at 135 0 C. The pH of the distillated is adjusted between 5,5 - 6,0; ethanol is adicioned in 50% titrating the resultant solution with La(NO 3 ) 3 . In these conditions, fluoride ions are determined with accuracy respectively, 5% and 4%. Natural samples of drinking water were analysed by this method and by the ion selective method, with agreement among the results. (author) [pt

  4. Response of electret dosemeter to slow neutrons

    International Nuclear Information System (INIS)

    Ghilardi, A.J.P.; Pela, C.A.; Zimmerman, R.L.

    1987-01-01

    The response of the electret dosemeter to exposition of slow neutrons is studied. Different external coatings are used on the dosemeter (polyethylene, alminium, polyethylene + boron, aluminium + boron) and exposure curves (with and without water) are compared. (M.A.C.) [pt

  5. Slowed ageing, welfare, and population problems.

    Science.gov (United States)

    Wareham, Christopher

    2015-10-01

    Biological studies have demonstrated that it is possible to slow the ageing process and extend lifespan in a wide variety of organisms, perhaps including humans. Making use of the findings of these studies, this article examines two problems concerning the effect of life extension on population size and welfare. The first--the problem of overpopulation--is that as a result of life extension too many people will co-exist at the same time, resulting in decreases in average welfare. The second--the problem of underpopulation--is that life extension will result in too few people existing across time, resulting in decreases in total welfare. I argue that overpopulation is highly unlikely to result from technologies that slow ageing. Moreover, I claim that the problem of underpopulation relies on claims about life extension that are false in the case of life extension by slowed ageing. The upshot of these arguments is that the population problems discussed provide scant reason to oppose life extension by slowed ageing.

  6. Analysis of the neutron slowing down equation

    International Nuclear Information System (INIS)

    Sengupta, A.; Karnick, H.

    1978-01-01

    The infinite series solution of the elementary neutron slowing down equation is studied using the theory of entire functions of exponential type and nonharmonic Fourier series. It is shown from Muntz--Szasz and Paley--Wiener theorems, that the set of exponentials ]exp(ilambda/sub n/u) ]/sup infinity//sub n/=-infinity, where ]lambda/sub n/]/sup infinity//sub n/=-infinity are the roots of the transcendental equation in slowing down theory, is complete and forms a basis in a lethargy interval epsilon. This distinctive role of the maximum lethargy change per collision is due to the Fredholm character of the slowing down operator which need not be quasinilpotent. The discontinuities in the derivatives of the collision density are examined by treating the slowing down equation in its differential-difference form. The solution (Hilbert) space is the union of a countable number of subspaces L 2 (-epsilon/2, epsilon/2) over each of which the exponential functions are complete

  7. Holographic Gratings for Slow-Neutron Optics

    Science.gov (United States)

    Klepp, Juergen; Pruner, Christian; Tomita, Yasuo; Geltenbort, Peter; Drevenšek-Olenik, Irena; Gyergyek, Saso; Kohlbrecher, Joachim; Fally, Martin

    2012-01-01

    Recent progress in the development of holographic gratings for neutron-optics applications is reviewed. We summarize the properties of gratings recorded in deuterated (poly)methylmethacrylate, holographic polymer-dispersed liquid crystals and nanoparticle-polymer composites revealed by diffraction experiments with slow neutrons. Existing and anticipated neutron-optical instrumentations based on holographic gratings are discussed.

  8. Preliminary characterization of slow growing rhizobial strains ...

    African Journals Online (AJOL)

    In this paper, we did some preliminary characterization of six slow growing rhizobial strains, isolated from Retama monosperma (L.) Boiss. root nodules sampled from 3 sites along the coast of Oran (CapeFalcon, Bousfer and MersElHadjadj) in Northwestern Algeria. Results of this study showed that all strains had a very ...

  9. Probabilistic Slow Features for Behavior Analysis

    NARCIS (Netherlands)

    Zafeiriou, Lazaros; Nicolaou, Mihalis A.; Zafeiriou, Stefanos; Nikitidis, Symeon; Pantic, Maja

    A recently introduced latent feature learning technique for time-varying dynamic phenomena analysis is the so-called slow feature analysis (SFA). SFA is a deterministic component analysis technique for multidimensional sequences that, by minimizing the variance of the first-order time derivative

  10. Learning slow features for behavior analysis

    NARCIS (Netherlands)

    Zafeiriou, Lazaros; Nicolaou, Mihalis A.; Zafeiriou, Stefanos; Nikitids, Symeon; Pantic, Maja

    2013-01-01

    A recently introduced latent feature learning technique for time varying dynamic phenomena analysis is the socalled Slow Feature Analysis (SFA). SFA is a deterministic component analysis technique for multi-dimensional sequences that by minimizing the variance of the first order time derivative

  11. A slow component of classic Stroop interference

    NARCIS (Netherlands)

    Phaf, R. Hans; Horsman, Hark H.; van der Moolen, Bas; Roos, Yvo B. W. E. M.; Schmand, Ben

    2010-01-01

    The interference in colour naming may extend beyond critical Stroop trials. This "slow'' effect was first discovered in emotional Stroop tasks, but is extended here to classical Stroop. In two experiments, meaningless coloured letter strings followed a colour word or neutral word. Student

  12. Slow evaporation method and enhancement in photoluminescence ...

    Indian Academy of Sciences (India)

    MS received 31 May 2015; accepted 1 February 2016. Abstract. The series of Bi3+ co-doped YPO4 : Eu3+ nanophosphors were successfully synthesized by the slow evaporation method. Bi3+-doped and un-doped YPO4 : Eu3+ phosphors were characterized by using powder X-ray diffraction, Fourier transform infrared ...

  13. A randomised controlled trial of a lengthened and multi-disciplinary consultation model in a socially deprived community: a study protocol.

    LENUS (Irish Health Repository)

    Whitford, David L

    2007-01-01

    BACKGROUND: There has been little development of the general practice consultation over the years, and many aspects of the present consultation do not serve communities with multiple health and social problems well. Many of the problems presenting to general practitioners in socio-economically disadvantaged areas are not amenable to a purely medical solution, and would particularly benefit from a multidisciplinary approach. Socio-economic deprivation is also associated with those very factors (more psychosocial problems, greater need for health promotion, more chronic diseases, more need for patient enablement) that longer consultations have been shown to address. This paper describes our study protocol, which aims to evaluate whether a lengthened multidisciplinary primary care team consultation with families in a socially deprived area can improve the psychological health of mothers in the families. METHODS\\/DESIGN: In a randomised controlled trial, families with a history of social problems, substance misuse or depression are randomly allocated to an intervention or control group. The study is based in three general practices in a highly deprived area of North Dublin. Primary health care teams will be trained in conducting a multidisciplinary lengthened consultation. Families in the intervention group will participate in the new style multidisciplinary consultation. Outcomes of families receiving the intervention will be compared to the control group who will receive only usual general practitioner care. The primary outcome is the psychological health of mothers of the families and secondary outcomes include general health status, quality of life measures and health service usage. DISCUSSION: The main aim of this study is to evaluate the effectiveness of a lengthened multidisciplinary team consultation in primary care. The embedded nature of this study in general practices in a highly deprived area ensures generalisability to other deprived communities, but more

  14. Measuring titratable alkalinity by single versus double endpoint titration: An evaluation in two cyprinodont species and implications for characterizing net H+ flux in aquatic organisms.

    Science.gov (United States)

    Brix, Kevin V; Wood, Chris M; Grosell, Martin

    2013-01-01

    In this study, Na(+) uptake and acid-base balance in the euryhaline pupfish Cyprinodon variegatus variegatus were characterized when fish were exposed to pH 4.5 freshwater (7mM Na(+)). Similar to the related cyprinodont, Fundulus heteroclitus, Na(+) uptake was significantly inhibited when exposed to low pH water. However, it initially appeared that C. v. variegatus increased apparent net acid excretion at low pH relative to circumneutral pH. This result is opposite to previous observations for F. heteroclitus under similar conditions where fish were observed to switch from apparent net H(+) excretion at circumneutral pH to apparent net H(+) uptake at low pH. Further investigation revealed disparate observations between these studies were the result of using double endpoint titrations to measure titratable alkalinity fluxes in the current study, while the earlier study utilized single endpoint titrations to measure these fluxes (i.e.,. Cyprinodon acid-base transport is qualitatively similar to Fundulus when characterized using single endpoint titrations). This led to a comparative investigation of these two methods. We hypothesized that either the single endpoint methodology was being influenced by a change in the buffer capacity of the water (e.g., mucus being released by the fish) at low pH, or the double endpoint methodology was not properly accounting for ammonia flux by the fish. A series of follow-up experiments indicated that buffer capacity of the water did not change significantly, that excretion of protein (a surrogate for mucus) was actually reduced at low pH, and that the double endpoint methodology does not properly account for NH(3) excretion by fish under low pH conditions. As a result, it overestimates net H(+) excretion during low pH exposure. After applying the maximum possible correction for this error (i.e., assuming that all ammonia is excreted as NH(3)), the double endpoint methodology indicates that net H(+) transport was reduced to

  15. The SimpleMix study with biphasic insulin aspart 30: a randomized controlled trial investigating patient-driven titration versus investigator-driven titration.

    Science.gov (United States)

    Gao, Yan; Luquez, Cecilia; Lynggaard, Helle; Andersen, Henning; Saboo, Banshi

    2014-12-01

    The study aimed to confirm the efficacy, through non-inferiority, of patient-driven versus investigator-driven titration of biphasic insulin aspart 30 (BIAsp 30) in terms of glycemic control assessed by HbA1c change. SimpleMix was a 20 week, open-label, randomized, two-armed, parallel-group, multicenter study in five countries (Argentina, China, India, Poland, and the UK). Patients with type 2 diabetes were randomized into either patient-driven or investigator-driven BIAsp 30 titration groups. Non-inferiority of patient-driven vs. investigator-driven titration based on change in HbA1c from baseline to week 20 could not be demonstrated. Mean (SE) estimated change from baseline to week 20 was -0.72 (0.08)% in the patient-driven group and -0.97 (0.08)% in the investigator-driven group; estimated difference 0.25% (95% CI: 0.04; 0.46). Estimated mean change (SE) in fasting plasma glucose from baseline to week 20 was similar between groups: -0.94 (0.21) mmol/L for patient-driven and -1.07 (0.22) mmol/L for investigator-driven (difference non-significant). Both treatment arms were well tolerated, and hypoglycemic episode rates were similar between groups, with a rate ratio of 0.77 (95% CI: 0.54; 1.09; p = 0.143) for all hypoglycemic episodes and 0.78 (95% CI: 0.42; 1.43; p = 0.417) for nocturnal hypoglycemic episodes. Non-inferiority of patient-driven versus investigator-driven titration with regard to change from baseline to end-of-treatment HbA1c could not be confirmed. It is possible that a clinic visit 12 weeks after intensification of treatment with BIAsp 30 in patients with type 2 diabetes inadequately treated with basal insulin may benefit patient-driven titration of BIAsp 30. A limitation of the study was the relatively small number of patients recruited in each country, which does not allow country-specific analyses to be performed. Overall, treatment with BIAsp 30 was well tolerated in both treatment groups.

  16. Analysis of slow-wave activity and slow-wave oscillations prior to somnambulism.

    Science.gov (United States)

    Jaar, Olivier; Pilon, Mathieu; Carrier, Julie; Montplaisir, Jacques; Zadra, Antonio

    2010-11-01

    STUDY OBJECTIVIES: several studies have investigated slow wave sleep EEG parameters, including slow-wave activity (SWA) in relation to somnambulism, but results have been both inconsistent and contradictory. The first goal of the present study was to conduct a quantitative analysis of sleepwalkers' sleep EEG by studying fluctuations in spectral power for delta (1-4 Hz) and slow delta (0.5-1 Hz) before the onset of somnambulistic episodes. A secondary aim was to detect slow-wave oscillations to examine changes in their amplitude and density prior to behavioral episodes. twenty-two adult sleepwalkers were investigated polysomnographically following 25 h of sleep deprivation. analysis of patients' sleep EEG over the 200 sec prior to the episodes' onset revealed that the episodes were not preceded by a gradual increase in spectral power for either delta or slow delta over frontal, central, or parietal leads. However, time course comparisons revealed significant changes in the density of slow-wave oscillations as well as in very slow oscillations with significant increases occurring during the final 20 sec immediately preceding episode onset. the specificity of these sleep EEG parameters for the occurrence and diagnosis of NREM parasomnias remains to be determined.

  17. Acid-base titrations for polyacids: Significance of the pK sub a and parameters in the Kern equation

    Science.gov (United States)

    Meites, L.

    1978-01-01

    A new method is suggested for calculating the dissociation constants of polyvalent acids, especially polymeric acids. In qualitative form the most significant characteristics of the titration curves are demonstrated and identified which are obtained when titrating the solutions of such acids with a standard base potentiometrically.

  18. On the virtue of acid–base titrations for the determination of basic sites in nitrogen doped carbon nanotubes

    NARCIS (Netherlands)

    Bitter, J.H.; van Dommele, S.; de Jong, K.P.

    2013-01-01

    The basicity and nature of basic species in nitrogen containing carbon nanotubes (NCNT) prepared under different conditions were investigated by acid–base titrations. Proton uptake curves were derived from the titration data and were used to establish the basicity (pKa) ranges of nitrogen species

  19. The Quantitative Resolution of a Mixture of Group II Metal Ions by Thermometric Titration with EDTA. An Analytical Chemistry Experiment.

    Science.gov (United States)

    Smith, Robert L.; Popham, Ronald E.

    1983-01-01

    Presents an experiment in thermometric titration used in an analytic chemistry-chemical instrumentation course, consisting of two titrations, one a mixture of calcium and magnesium, the other of calcium, magnesium, and barium ions. Provides equipment and solutions list/specifications, graphs, and discussion of results. (JM)

  20. Determination of the point-of-zero, charge of manganese oxides with different methods including an improved salt titration method

    NARCIS (Netherlands)

    Tan, W.F.; Lu, S.J.; Liu, F.; Feng, X.H.; He, J.Z.; Koopal, L.K.

    2008-01-01

    Manganese (Mn) oxides are important components in soils and sediments. Points-of-zero charge (PZC) of three synthetic Mn oxides (birnessite, cryptomelane, and todorokite) were determined by using three classical techniques (potentiometric titration or PT, rapid PT or R-PT, and salt titration or ST)

  1. Safety of a web-based insulin titration system for patients with type 2 diabetes mellitus - pilot study

    NARCIS (Netherlands)

    Simon, A. C. R.; Holleman, F.; Gude, W. T.; Hoekstra, J. B. L.; Peek, N.

    2012-01-01

    The treatment of type 2 diabetes patients with insulin requires active dose titration to obtain optimal glycemic control. We developed a web-based decision support system to guide patients in performing the titration task autonomously, at their homes. The system is based on a clinically validated

  2. Slow and fast light in semiconductors

    Science.gov (United States)

    Sedgwick, Forrest Grant

    Slow and fast light are the propagation of optical signals at group velocities below and above the speed of light in a given medium. There has been great interest in the use of nonlinear optics to engineer slow and fast light dispersion for applications in optical communications and radio-frequency or microwave photonics. Early results in this field were primarily confined to dilute atomic systems. While these results were impressive, they had two major barriers to practical application. First, the wavelengths were not compatible with fiber optic telecommunications. More importantly, the bandwidth obtainable in these experiments was inherently low; 100 kHz or less. Within the last five years slow and fast light effects have been observed and engineered in a much wider variety of systems. In this work, we detail our efforts to realize slow and fast light in semiconductor systems. There are three primary advantages of semiconductor systems: fiber-compatible wavelengths, larger bandwidth, and simplification of integration with other optical components. In this work we will explore three different types of physical mechanisms for implementing slow and fast light. The first is electromagnetically induced transparency (EIT). In transporting this process to semiconductors, we initially turn our attention to quantum dots or "artificial atoms". We present simulations of a quantum dot EIT-based device within the context of an optical communications link and we derive results which are generally applicable to a broad class of slow light devices. We then present experimental results realizing EIT in quantum wells by using long-lived electron spin coherence. The second mechanism we will explore is coherent population oscillations (CPO), also known as carrier density pulsations (CDP). We examine for the first time how both slow and fast light may be achieved in a quantum well semiconductor optical amplifier (SOA) while operating in the gain regime. Again, we simulate the device

  3. Classification of calorimetric titration plots for alkyltrimethylammonium and alkylpyridinium cationic surfactants in aqueous solutions

    NARCIS (Netherlands)

    Bijma, K; Engberts, J.B.F.N.; Blandamer, M.J; Cullis, P.M.; Last, P.M.; Irlam, K.D.; Soldi, L.G.

    1997-01-01

    Calorimetric titration plots for deaggregation of micelles formed by alkylpyridinium and alkyltrimethylammonium surfactants are classified into three types, A, B and C, depending on the shape of the plot of the enthalpy of dilution as a function of surfactant concentration. For Type A plots the

  4. An open-label Optional Titration Trial to Evaluate the Efficacy ...

    African Journals Online (AJOL)

    An open-label Optional Titration Trial to Evaluate the Efficacy, Tolerability and Safety of Valsartan in Patients with Mild to Moderate Essential Hypertension Treated for 8 Weeks in the Lagos University Teaching Hospita. ... Only 5(8%) developed self limiting side effects known to be associated with the use of Valsartan. 3(5%) ...

  5. Evaluation of the number of ionogenic groups of inulinase by acid-base titration.

    Science.gov (United States)

    Kovaleva, T A; Holyavka, M G; Rezvan, S G; Kozhedub, S V

    2008-06-01

    Acid base titration showed that Aspergillus awamori inulinase includes 178 asparaginic and glutamic acid residues, 20 histidine, 10 serine, and 34 lysine and tyrosine residues. Denaturation temperature for this enzyme was calculated using analysis of the proportion of stabilizing and destabilizing amino acids in the molecule.

  6. Trace analysis of acids and bases by conductometric titration with multiparametric non-linear regression.

    Science.gov (United States)

    Coelho, Lúcia H G; Gutz, Ivano G R

    2006-03-15

    A chemometric method for analysis of conductometric titration data was introduced to extend its applicability to lower concentrations and more complex acid-base systems. Auxiliary pH measurements were made during the titration to assist the calculation of the distribution of protonable species on base of known or guessed equilibrium constants. Conductivity values of each ionized or ionizable species possibly present in the sample were introduced in a general equation where the only unknown parameters were the total concentrations of (conjugated) bases and of strong electrolytes not involved in acid-base equilibria. All these concentrations were adjusted by a multiparametric nonlinear regression (NLR) method, based on the Levenberg-Marquardt algorithm. This first conductometric titration method with NLR analysis (CT-NLR) was successfully applied to simulated conductometric titration data and to synthetic samples with multiple components at concentrations as low as those found in rainwater (approximately 10 micromol L(-1)). It was possible to resolve and quantify mixtures containing a strong acid, formic acid, acetic acid, ammonium ion, bicarbonate and inert electrolyte with accuracy of 5% or better.

  7. Developing a multipoint titration method with a variable dose implementation for anaerobic digestion monitoring.

    Science.gov (United States)

    Salonen, K; Leisola, M; Eerikäinen, T

    2009-01-01

    Determination of metabolites from an anaerobic digester with an acid base titration is considered as superior method for many reasons. This paper describes a practical at line compatible multipoint titration method. The titration procedure was improved by speed and data quality. A simple and novel control algorithm for estimating a variable titrant dose was derived for this purpose. This non-linear PI-controller like algorithm does not require any preliminary information from sample. Performance of this controller is superior compared to traditional linear PI-controllers. In addition, simplification for presenting polyprotic acids as a sum of multiple monoprotic acids is introduced along with a mathematical error examination. A method for inclusion of the ionic strength effect with stepwise iteration is shown. The titration model is presented with matrix notations enabling simple computation of all concentration estimates. All methods and algorithms are illustrated in the experimental part. A linear correlation better than 0.999 was obtained for both acetate and phosphate used as model compounds with slopes of 0.98 and 1.00 and average standard deviations of 0.6% and 0.8%, respectively. Furthermore, insensitivity of the presented method for overlapping buffer capacity curves was shown.

  8. Automation of potentiometric titration for the determination of uranium in nuclear fuel materials

    International Nuclear Information System (INIS)

    Kelkar, Anoop; Pandey, Ashish; Kapoor, Y.S.; Kumar, Manish; Singh, Mamta; Fulzele, Ajeet; Prakash, Amrit; Afzal, Mohd; Panakkal, J.P.

    2010-01-01

    Advanced Fuel Fabrication Facility is fabricating various types of mixed oxide fuels, namely for PHWR, BWR, FBTR and PFBR. Precise determination of uranium in MOX fuel sample is important to get desired burn up in the reactor. The modified Davies and Gray method is routinely used for the potentiometric titration of uranium

  9. Tested Demonstrations: Comparison of Strong Acid and Weak Acid Titration Curves.

    Science.gov (United States)

    Gilbert, George L., Ed.

    1979-01-01

    A lecture demonstration is presented for comparing titration curves. A plot of pH vs volume of strong base is produced by connecting the external output of a pH meter to a strip recorder. Thus, pH is recorded as a function of time. (BB)

  10. Thermometric titration of some monoprotic and diprotic acids in aqueous and non-aqueous media.

    Science.gov (United States)

    Harries, R J

    1968-12-01

    Some mono- and diprotic acids have been titrated thermometrically with strong alkalis in aqueous and non-aqueous media. Thermograms with sharp arrest points were obtained, from which heats of neutralization were measured. Heats of neutralization in the media used were compared and an effect attributable to hydrogen bonding was found.

  11. Determination of oxygen nonstoichiometry and diffusivity in mixed conducting oxides by oxygen Coulometric titration

    NARCIS (Netherlands)

    Lankhorst, M.H.R.; Lankhorst, Martijn H.R.; Bouwmeester, Henricus J.M.

    1997-01-01

    Oxygen coulometric titration has been applied to measure chemical diffusion in La0.8Sr0.2CoO3-δ between 700 and 1000°C. The transient current response to a potentiostatic step has been transformed from the time domain to the frequency domain. The equivalent circuit used to fit the resulting

  12. DETERMINATION OF WATER CONTENT IN PYROLYTIC TARS USING COULOMETRIC KARL-FISHER TITRATION

    Directory of Open Access Journals (Sweden)

    Lenka Jílková

    2017-02-01

    Full Text Available The liquid organic fraction of pyrolytic tar has a high energy value which makes possible its utilization as an energy source. However, before utilization, it is crucial to remove water from the liquid fraction. The presence of water reduces the energy value of pyrolytic tars. Water separation from the organic tar fraction is a complex process, since an emulsion can be readily formed. Therefore, after phase separation, it is important to know the residual water content in the organic phase and whether it is necessary to further dry it. The results presented in this manuscript focus on a water determination in liquid products from coal and biomass pyrolysis by a coulometric Karl‑Fischer titration. The Coulometric Karl‑Fischer titration is often used for a water content determination in gaseous, liquid and solid samples. However, to date, this titration method has not been used for a water determination in tars. A new water determination method, which has been tested on different types of tar, has been developed. The Coulometric Karl‑Fischer titration is suitable for tar samples with a water content not greater than 5 wt. %. The obtained experimental results indicate that the new introduced method can be used with a very good repeatability for a water content determination in tars.

  13. Single-experiment displacement assay for quantifying high-affinity binding by isothermal titration calorimetry.

    Science.gov (United States)

    Krainer, Georg; Keller, Sandro

    2015-04-01

    Isothermal titration calorimetry (ITC) is the gold standard for dissecting the thermodynamics of a biomolecular binding process within a single experiment. However, reliable determination of the dissociation constant (KD) from a single titration is typically limited to the range 100 μM>KD>1 nM. Interactions characterized by a lower KD can be assessed indirectly by so-called competition or displacement assays, provided that a suitable competitive ligand is available whose KD falls within the directly accessible window. However, this protocol is limited by the fact that it necessitates at least two titrations to characterize one high-affinity inhibitor, resulting in considerable consumption of both sample material and time. Here, we introduce a fast and efficient ITC displacement assay that allows for the simultaneous characterization of both a high-affinity ligand and a moderate-affinity ligand competing for the same binding site on a receptor within a single experiment. The protocol is based on a titration of the high-affinity ligand into a solution containing the moderate-affinity ligand bound to the receptor present in excess. The resulting biphasic binding isotherm enables accurate and precise determination of KD values and binding enthalpies (ΔH) of both ligands. We discuss the theoretical background underlying the approach, demonstrate its practical application to metal ion chelation, explore its potential and limitations with the aid of simulations and statistical analyses, and elaborate on potential applications to protein-inhibitor interactions. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Improving manual oxygen titration in preterm infants by training and guideline implementation

    NARCIS (Netherlands)

    van Zanten, Henriëtte A; Pauws, Steffen C; Beks, Evelien C; Stenson, Ben J; Lopriore, Enrico; Te Pas, Arjan B

    To study oxygen saturation (SpO2) targeting before and after training and guideline implementation of manual oxygen titration, two cohorts of preterm infants <30 weeks of gestation needing respiratory support and oxygen therapy were compared. The percentage of the time spent with SpO2 within the

  15. An Exact Method to Determine the Conductivity of Aqueous Solutions in Acid-Base Titrations

    Directory of Open Access Journals (Sweden)

    Norma Rodríguez-Laguna

    2015-01-01

    Full Text Available Several works in the literature show that it is possible to establish the analytic equations to estimate the volume V of a strong base or a strong acid (Vb and Va, resp. being added to a solution of a substance or a mix of substances during an acid-base titration, as well as the equations to estimate the first derivative of the titration plot dpH/dV, and algebraic expressions to determine the buffer β capacity with dilution βdil. This treatment allows establishing the conditions of thermodynamic equilibria for all species within a system containing a mix of species from one or from various polyacid systems. The present work shows that it is possible to determine exactly the electric conductivity of aqueous solutions for these Brønsted acid-base titrations, because the functional relation between this property and the composition of the system in equilibrium is well known; this is achieved using the equivalent conductivity λi values of each of the ions present in a given system. The model employed for the present work confirms the experimental outcomes with the H2SO4, B(OH3, CH3COOH, and H3PO4 aqueous solutions’ titration.

  16. pH and Titratable Acidity of different Cough Syrups in Nigeria ...

    African Journals Online (AJOL)

    Background: Cough linctuses are liquid oral medicines widely used in children to treat cough and related conditions. Some of their constituents are acidic and dental erosive. Objectives: This in vitro study aimed to evaluate the endogenous pH and titratable acidity of Nigerian cough syrups and also determine their erosive ...

  17. Development and validation of a simplified titration method for monitoring volatile fatty acids in anaerobic digestion.

    Science.gov (United States)

    Sun, Hao; Guo, Jianbin; Wu, Shubiao; Liu, Fang; Dong, Renjie

    2017-09-01

    The volatile fatty acids (VFAs) concentration has been considered as one of the most sensitive process performance indicators in anaerobic digestion (AD) process. However, the accurate determination of VFAs concentration in AD processes normally requires advanced equipment and complex pretreatment procedures. A simplified method with fewer sample pretreatment procedures and improved accuracy is greatly needed, particularly for on-site application. This report outlines improvements to the Nordmann method, one of the most popular titrations used for VFA monitoring. The influence of ion and solid interfering subsystems in titrated samples on results accuracy was discussed. The total solid content in titrated samples was the main factor affecting accuracy in VFA monitoring. Moreover, a high linear correlation was established between the total solids contents and VFA measurement differences between the traditional Nordmann equation and gas chromatography (GC). Accordingly, a simplified titration method was developed and validated using a semi-continuous experiment of chicken manure anaerobic digestion with various organic loading rates. The good fitting of the results obtained by this method in comparison with GC results strongly supported the potential application of this method to VFA monitoring. Copyright © 2017. Published by Elsevier Ltd.

  18. Statistical evaluation of an interlaboratory comparison for the determination of uranium by potentiometric titration

    International Nuclear Information System (INIS)

    Ketema, D.J.; Harry, R.J.S.; Zijp, W.L.

    1990-09-01

    Upon request of the ESARDA working group 'Low enriched uranium conversion - and fuel fabrication plants' an interlaboratory comparison was organized, to assess the precision and accuracy concerning the determination of uranium by the potentiometric titration method. This report presents the results of a statistical evaluation on the data of the first phase of this exercise. (author). 9 refs.; 5 figs.; 24 tabs

  19. Prescribing and up-titration in recently hospitalized heart failure patients attending a disease management program.

    Science.gov (United States)

    Carroll, Robert; Mudge, Alison; Suna, Jessica; Denaro, Charles; Atherton, John

    2016-08-01

    Heart failure (HF) medications improve clinical outcomes, with optimal doses defined in clinical trials. Patient, provider and system barriers may limit achievement of optimal doses in real life settings, although disease management programs (HF-DMPs) can facilitate up-titration. Secondary analysis of a prospective cohort of 216 participants recently hospitalized with systolic HF, attending 5 HF-DMPs in Queensland, Australia. Medication history at baseline (6weeks after discharge) and 6months provided data to describe prescription rates, dosage and optimal titration of HF medications, and associations with patient and system factors were explored. At baseline, 94% were on an angiotensin converting enzyme inhibitor/angiotensin II receptor blocker (ACEI/ARB), 94% on a beta-blocker (BB) and 42% on a mineralocorticoid receptor antagonist (MRA). The proportion of participants on optimal doses of ACEI/ARB increased from 38% (baseline) to 52% (6months, p=0.001) and on optimal BB dose from 23% to 49% (ptitration were body mass index (BMI)titration were BMItitration in HF DMPs is influenced by patient, disease and service factors. Better understanding of barriers to effective up-titration in women, normal weight, and established HF patients may help provide targeted strategies for improving outcomes in these groups. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Isothermal Titration Calorimetry and Macromolecular Visualization for the Interaction of Lysozyme and Its Inhibitors

    Science.gov (United States)

    Wei, Chin-Chuan; Jensen, Drake; Boyle, Tiffany; O'Brien, Leah C.; De Meo, Cristina; Shabestary, Nahid; Eder, Douglas J.

    2015-01-01

    To provide a research-like experience to upper-division undergraduate students in a biochemistry teaching laboratory, isothermal titration calorimetry (ITC) is employed to determine the binding constants of lysozyme and its inhibitors, N-acetyl glucosamine trimer (NAG[subscript 3]) and monomer (NAG). The extremely weak binding of lysozyme/NAG is…