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Sample records for pressure sores formation

  1. Pressure Sores

    MedlinePlus

    ... night. Pressure sores also are called bedsores or pressure ulcers. The sores change appearance over 4 stages. In ... SeniorsTags: antibiotics, Dermatologic, elderly, higher, older adults, Overview, Pressure Ulcers Family Health, Seniors September 2000 Copyright © American Academy ...

  2. Pressure Sores

    MedlinePlus

    Pressure sores are areas of damaged skin caused by staying in one position for too long. They ... wheelchair, or are unable to change your position. Pressure sores can cause serious infections, some of which ...

  3. Skin (Pressure) Sores

    MedlinePlus

    ... Dry Skin Itching Skin Color Changes Pressure Sores Scars and Wounds Treatments and Side Effects Managing Cancer-related Side Effects ... Dry Skin Itching Skin Color Changes Pressure Sores Scars and Wounds More In Treatment & Support Understanding Your Diagnosis Finding and Paying for ...

  4. [Pressure sore revision surgery].

    PubMed

    Dorsche, Karin Marion

    2010-02-22

    Pressure sores are a major problem for patients as well as society in general. Immobilised patients are especially at risk. This group of patients with pressure sores should be hospitalised to perform surgical revision of the wound and reconstruction using a flap. Such surgery demands extensive postoperative relief of the flap. The University Centre for Wound Healing at Odense University Hospital has tested the effects of a reduction of the formerly recommended relief period from three to two weeks. In this article we report results covering all patients who have undergone surgery and reconstruction of pressure sores during the period from 1st October 2001 to 1st November 2008. The results are divided into two periods: the period before and the period after the introduction of the reduced relief period. A total of 80 patients were included; 34 in the first period and 46 in the second period. We achieved a considerable reduction in median length of stay from 38 to 27 days with no increase in surgical or complication frequency. Furthermore, the share of fully healed remained unchanged. We believe that there is no risk in shortening the immobile postoperative relief phase following reconstruction of pressure wounds in immobilised patients.

  5. Practical Management of Pressure Sores

    PubMed Central

    Jordan, John M.

    1992-01-01

    Pressure sores are common in the debilitated elderly. Causal factors are unrelieved pressure, shearing forces, friction, and moisture. Preventive measures should be used for all high-risk patients, defined by general condition, mental status, degree of incontinence, amount of activity, and mobility. Principles of treating ulcers include pressure relief, reducing bacterial counts, debriding necrotic tissue, and providing a moist, clean environment. Imagesp2385-ap2389-ap2392-a PMID:21221298

  6. Bedsores (Pressure Sores)

    MedlinePlus

    ... Berlowitz D. Treatment of pressure ulcers. http://www.uptodate.com/home. Accessed Nov. 12, 2013. Gestring M. Negative pressure wound therapy. http://www.uptodate.com/home. Accessed Nov. 12, 2013. AskMayoExpert. Pressure ...

  7. Bedsores (Pressure Sores)

    MedlinePlus

    ... Complications of pressure ulcers, some life-threatening, include: Cellulitis. Cellulitis is an infection of the skin and connected ... not feel pain in the area affected by cellulitis. Bone and joint infections. An infection from a ...

  8. Pressure sore prevention in acutely ill patients.

    PubMed

    James, H

    1997-03-01

    A wide range of factors affect the skin's ability to withstand pressure, friction and shear. Clinically validated pressure-relieving equipment is essential to prevent pressure sores in acutely ill patients. A successful pressure sore prevention strategy depends on sufficient resource allocation, appropriate levels and types of preventive equipment and evaluation.

  9. Evidence-based medicine: pressure sores.

    PubMed

    Cushing, Carolyn A; Phillips, Linda G

    2013-12-01

    After studying this article, the participant should be able to: 1. Cite risk factors for pressure sore development. 2. Detail the pathophysiology of pressure sores. 3. List the types and classification of pressure sores. 4. Consider the various nonsurgical conservative wound management strategies. 5. Describe the appropriate surgical interventions for each pressure sore type. 6. Understand the causes of recurrent pressure sores and methods of avoiding recurrence. Pressure sores are the result of unrelieved pressure, usually over a bony prominence. With an estimated 2.5 million pressure ulcers treated annually in the United States at a cost of $11 billion, pressure sores represent a costly and labor-intensive challenge to the health care system. A comprehensive team approach can address both prevention and treatment of these recalcitrant wounds. Consideration must be given to the patient's medical and socioeconomic condition, as these factors are significantly related to outcomes. Mechanical prophylaxis, nutritional optimization, treatment of underlying infection, and spasm control are essential in management. A variety of pressure sore patterns exist, with surgical approaches directed to maximize future coverage options. A comprehensive approach is detailed in this article to provide the reader with the range of treatment options available.

  10. Pressure sore prevention in nursing homes.

    PubMed

    Clay, M

    Staff working in nursing homes are caring for increasingly dependent residents who are consequently at great risk of developing pressure sores. Mary Clay offers a guide to the essential principles of pressure sore prevention as a teaching aid for all caring staff.

  11. Pressure sore--the problem.

    PubMed

    Brand, P W

    2006-05-01

    The problem is that when the surface of the body is denervated, it is liable to break down from a number of widely different mechanical stresses. The obvious common factor of denervation or loss of sensation has allowed many workers to assume that loss of nerves is the most significant element in the aetiology of these pressure sores. Hence, the term 'trophic' ulcer, which suggests that some trophic, or nourishing, element is missing from tissues which are not supported by intact nerves. The nature of this trophic factor is not understood and therefore its influence is difficult to measure and still more difficult to control. We have found that a more fruitful approach to the problem is to concentrate upon the biology and the mechanics of the breakdown of normal surface tissues, and then see if it is very different from the biology and mechanics of the breakdown of denervated tissues.

  12. The limits of pressure sore prevention.

    PubMed Central

    Hagisawa, S; Barbenel, J

    1999-01-01

    Pressure sore prevalence and incidence were assessed in 275 patients who were admitted to a well-staffed internal medicine ward during a 12-month study period or who were present on day 1. Pressure sore risk was assessed by use of the Braden scale and patients scoring 16 or less were provided with intensive preventive care. During the study period 5.1% (95% confidence interval 2.7-7.8) of 275 patients had pressure sores (prevalence) and 4.4% (1.9-6.9) developed sores (incidence). None of the 239 patients who were assessed as not being at risk developed a sore. 36 patients were assessed as being at risk at some time during the study and 12 of these developed sores despite receiving high-quality preventive care. The results suggest that not all pressure sores can be prevented in severely ill patients. We believe that the 4.4% incidence of sores in this study approaches the current limit of prevention. PMID:10703495

  13. The limits of pressure sore prevention.

    PubMed

    Hagisawa, S; Barbenel, J

    1999-11-01

    Pressure sore prevalence and incidence were assessed in 275 patients who were admitted to a well-staffed internal medicine ward during a 12-month study period or who were present on day 1. Pressure sore risk was assessed by use of the Braden scale and patients scoring 16 or less were provided with intensive preventive care. During the study period 5.1% (95% confidence interval 2.7-7.8) of 275 patients had pressure sores (prevalence) and 4.4% (1.9-6.9) developed sores (incidence). None of the 239 patients who were assessed as not being at risk developed a sore. 36 patients were assessed as being at risk at some time during the study and 12 of these developed sores despite receiving high-quality preventive care. The results suggest that not all pressure sores can be prevented in severely ill patients. We believe that the 4.4% incidence of sores in this study approaches the current limit of prevention.

  14. Taking Care of Pressure Sores

    MedlinePlus

    ... between dressing changes. 6. Check for signs of wound healing with each dressing change. 7. If there are ... Surgery is frequently required for this type of wound. How to know if the sore is healing The sore will get smaller. Pinkish tissue usually ...

  15. Pressure sore prevention in nursing homes.

    PubMed

    Clay, M

    Staff working in nursing homes are caring for ever more dependent residents who are consequently at great risk of developing pressure sores. Mary Clay offers a guide to the essential principles as a teaching aid for all caring staff.

  16. Free flaps for pressure sore coverage.

    PubMed

    Lemaire, Vincent; Boulanger, Kevin; Heymans, Oliver

    2008-06-01

    Management of pressure sores still represents a major challenge in plastic surgery practice due to recurrence. The surgeon may have to face multiple or recurrent pressure ulcerations without any local flap left. In this very limited indication, free flap surgery appears to be a useful adjunct in the surgical treatment. We reviewed our charts looking for patients operated for a pressure sore of the sacral, ischial, or trochanteric region. We found 88 consecutive patients representing 108 different pressure sores and 141 flap procedures. Among these patients, 6 presented large sores that could not be covered with a pedicled flap and benefited from free flap surgery (4.2% of all procedures). Stable coverage was achieved in 80% of these patients after a mean follow-up of 32 months. Comparison between pedicled and free flaps groups showed a trend in the latest concerning the presence of diabetes, incontinence, paraplegia, and male sex.

  17. Pressure sore risk assessment in palliative care.

    PubMed

    Chaplin, J

    2000-01-01

    Pressure sore prevention in palliative care is recognized as being an essential element of holistic care, with the primary goal of promoting quality of life for patient and family. Little is known about the incidence of pressure sore development and the use of pressure sore risk assessment tools in palliative care settings. The development of a risk assessment tool specifically for palliative care patients in a 41-bedded specialist palliative care unit is described. The risk assessment tool was developed as part of a tissue viability practice development initiative. The approach adopted in the validation of the Hunters Hill Marie Curie Centre pressure sore risk assessment tool was the comparative analysis of professional judgment of experienced palliative care nurses with the numerical scores achieved during the assessment of risk on 291 patients (529 risk assessment events). This comparative analysis identified the threshold for different degrees of risk for the patient group involved: low risk, medium risk, high risk and very high risk. Further work is being undertaken to evaluate the inter-rater reliability of the new tool. A number of issues are explored in this paper in relation to pressure sore prevention in palliative care: the role of risk assessment tools, the sometimes conflicting aims of trying to ensure comfort and prevent pressure sore damage, and the uncertainties faced by palliative care nurses when they are trying to maintain quality of life for the dying.

  18. The use of argon beam coagulation in pressure sore reconstruction.

    PubMed

    Buck, Donald W; Lewis, Victor L

    2009-12-01

    Pressure sores are a significant source of physical and financial burden for debilitated patients. When conservative measures fail, surgical reconstruction with myocutaneous flaps may be the last hope for cure and/or improved quality of life in these patients. Adequate haemostasis is an integral component of these reconstructive procedures, as bleeding and haematoma formation can lead to increased morbidity. This study was designed to investigate the use of argon beam coagulation in patients undergoing bony debridement and subsequent pressure sore reconstruction with myocutaneous flaps. The clinical records of 34 patients undergoing pressure sore reconstruction with the use of argon beam coagulation from 2004 to 2006 at an academic institution were reviewed and outcomes were assessed. Reconstruction was performed by a single surgeon on 34 patients (31 men, three women; mean age 41+/-15 years), with a total of 41 pressure sores. Thirteen (32.5%) patients had evidence of osteomyelitis preoperatively and five (12.5%) had previous coccygectomies secondary to infection. Twenty-six (65%) of the pressure sores were treated with hamstring V-Y musculocutaneous flaps, 10 (25%) with gluteal flaps, and four (10%) with tensor fascia lata flaps. Overall, suture line dehiscence occurred in six (15%) cases, flap failure and pressure sore recurrence occurred in six (15%) cases, an abscess developed in one (2.5%) case, and a sinus tract with a superficial wound developed in one (2.5%) case. There were no complications related to haemostasis, including excessive bleeding or haematoma formation. Argon beam coagulation is an efficacious tool for achieving adequate haemostasis during pressure sore reconstruction, particularly when significant bony debridement is involved. The use of argon beam coagulation does not result in an increased complication or recurrence rate when compared with conventional electrocautery methods.

  19. Pressure sore risk assessment in children.

    PubMed

    Waterlow, J A

    1997-07-01

    A multi-centred study was undertaken involving 300 children ranging from neonates to children aged 16 years. The purpose of the study was to investigate the possibility of designing a pressure sore risk assessment scoring system suitable for the paediatric area of care. It was found that the following conclusions can be drawn: (i) Children are at risk of developing pressure sores; (ii) A version of the adult Waterlow card was not appropriate, especially at the younger end of the scale; (iii) There are identifiable situations and treatments which do pose a risk of pressure sore development. Admission documentation and a care plan within a hospital policy is recommended as the best method of drawing nurses' attention to the risk factors involved and the measures which need to be taken to alleviate the risk of tissue damage.

  20. Silicone moulding for pressure sore debridement.

    PubMed

    Erba, P; Wettstein, R; Schumacher, R; Schwenzer-Zimmerer, K; Pierer, G; Kalbermatten, D F

    2010-03-01

    The radicality of wound debridement is an important feature of the surgical treatment of pressure sores. Several methods such as injection of methylene blue or hydrogen peroxide have been proposed to facilitate and optimise the surgical debridement technique, but none of them proved to be sufficient. We present an innovative modification of the pseudo-tumour technique consisting in the injection of fluid silicone. Vulcanization of the silicone leads to pressure-sore moulding, permitting a more radical and sterile excision. In a series of 10 paraplegic patients presenting with ischial pressure sores, silicone moulding was used to facilitate debridement. Radical en bloc debridement was achieved in all patients. After a minimal follow-up of 2 years, no complications and recurrences occurred. A three-dimensional (3D) analysis of the silicone prints objectified the pyramidal shape of ischial pressure sores. Our study showed that complete resection without capsular lesion can be easily achieved. Further, it allows the surgeon to analyse the shape and size of the resected defect, which might be helpful to select the appropriate defect coverage technique. (c) 2008 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  1. Pressure sore survey. Part 3: Locus of control.

    PubMed

    Maylor, M; Torrance, C

    1999-03-01

    This is the third in a three-part article which investigates the prevalence, knowledge and attitudes to pressure sores in one NHS trust. This study describes the methodology used in choosing and developing attitude scales to explore whether there are any relationships between the locus of control and pressure sore prevention. Factors to do with attitude and the value associated with pressure sore prevention have a central role. Attitudes and beliefs affect what we do and may contribute to pressure sore development.

  2. The principles of pressure sore prevention.

    PubMed

    Quinn, D

    In the first Practice Profile to be published in Nursing Standard, Debbie Quinn demonstrates how studying a Continuing Education reader helped to develop an area of clinical practice--the prevention of pressure sores. Continuing Education Readers are made up of between four and six CPD (previously CE) articles and Debbie based her Profile on one of these. We will be publishing further Practice Profiles related to CPD articles.

  3. The 'reading man flap' for pressure sore reconstruction.

    PubMed

    Sapountzis, Stamatis; Park, Hyoung Joon; Kim, Ji Hoon; Chantes, Achilleas; Beak, Rong Min; Heo, Chan Yeong

    2011-09-01

    The treatment of pressure sores represents a significant challenge to health care professionals. Although, pressure wound management demands a multidisciplinary approach, soft tissue defects requiring reconstruction are often considered for surgical management. Myocutaneous and fasciocutaneous flaps can provide stable coverage of pressure sores. Here, we describe our experience using a recent fasciocutaneous flap, which is named 'reading man' flap, in sacral, ischial, and trochanteric pressure sores. During a period of 1 year the authors operated 16 patients, 11 men, and 5 women, using the reading man flap. The ages of the patients ranged from 24 to 78 years. The location of pressure sores was 8 sacral, 5 ischial, and 3 trochanteric pressure sores. The mean size of pressure sores was 8 cm × 9 cm. All pressure sores covered bt the Reading Man flap healed asymptomatically. After follow-up of 2-8 months, no recurrences were encountered and no further surgical intervention was required. The reading man flap was found to be a useful technique for the closure of pressure sore in different anatomic locations. The advantage of tension-free closure and the minimal additional healthy skin excision made this flap a useful tool in pressure sore reconstructions.

  4. The ‘reading man flap’ for pressure sore reconstruction

    PubMed Central

    Sapountzis, Stamatis; Park, Hyoung Joon; Kim, Ji Hoon; Chantes, Achilleas; Beak, Rong Min; Heo, Chan Yeong

    2011-01-01

    Background: The treatment of pressure sores represents a significant challenge to health care professionals. Although, pressure wound management demands a multidisciplinary approach, soft tissue defects requiring reconstruction are often considered for surgical management. Myocutaneous and fasciocutaneous flaps can provide stable coverage of pressure sores. Purpose: Here, we describe our experience using a recent fasciocutaneous flap, which is named ‘reading man’ flap, in sacral, ischial, and trochanteric pressure sores. Materials and Methods: During a period of 1 year the authors operated 16 patients, 11 men, and 5 women, using the reading man flap. The ages of the patients ranged from 24 to 78 years. The location of pressure sores was 8 sacral, 5 ischial, and 3 trochanteric pressure sores. The mean size of pressure sores was 8 cm × 9 cm. Results: All pressure sores covered bt the Reading Man flap healed asymptomatically. After follow-up of 2-8 months, no recurrences were encountered and no further surgical intervention was required. Conclusion: The reading man flap was found to be a useful technique for the closure of pressure sore in different anatomic locations. The advantage of tension-free closure and the minimal additional healthy skin excision made this flap a useful tool in pressure sore reconstructions. PMID:22279278

  5. Trunk, abdomen, and pressure sore reconstruction.

    PubMed

    Rubayi, Salah; Chandrasekhar, Bala S

    2011-09-01

    After reading this article, the participant should be able to: 1. Describe the principles of wound closure, torso reconstruction, and pressure sore reconstruction. 2. Outline standard options to treat defects of the chest, abdomen, and back and pressure ulcers in all anatomical areas. 3. Manage and prevent pressure ulcers. Chest wall reconstruction is indicated following tumor resection, radiation wound breakdown, or intrathoracic sepsis. Principles of wound closure and chest wall stabilization, where indicated, are discussed. Principles of abdominal wall reconstruction continue to evolve with the introduction of newer bioprosthetics and the application of functional concepts for wound closure. The authors illustrate these principles using commonly encountered clinical scenarios and guidelines to achieve predictable results. Pressure ulcers continue to be devastating complications to patients' health and a functional hazard when they occur in the bedridden, in patients with spinal cord injuries, and in patients with neuromuscular disease. Management of pressure ulcers is also very expensive. The authors describe standard options to treat defects of the chest, abdomen, and back and pressure ulcers in all anatomical areas. A comprehensive understanding of principles and techniques will allow practitioners to approach difficult issues of torso reconstruction and pressure sores with a rational confidence and an expectation of generally satisfactory outcomes. With pressure ulcers, prevention remains the primary goal. Patient education and compliance coupled with a multidisciplinary team approach can reduce their occurrence significantly. Surgical management includes appropriate patient selection, adequate débridement, soft-tissue coverage, and use of flaps that will not limit future reconstructions if needed. Postoperatively, a strict protocol should be adapted to ensure the success of the flap procedure. Several myocutaneous flaps commonly used for the surgical

  6. Pressure sore prevention in hospital patients: a clinical audit.

    PubMed

    Grewal, P S; Sawant, N H; Deaney, C N; Gibson, K M; Gupta, A M; Haverty, P F; Panditaratne, H G; Samarasinghe, S R; Sharma, A; Singh, S; Turner, S A; Wilkinson, S L; Wood, S P; Glickman, S

    1999-03-01

    Pressure sores cause significant mortality and morbidity as well as being a financial burden on health-care services. Reduction of pressure sore incidence is a Department of Health priority. Pressure sores are accepted as largely preventable complications of illness and disability and the means to achieve prevention are available. The aim of this clinical audit was to identify potential contributing factors to pressure sore acquisition in an acute hospital setting. The results suggest that substantial changes in the approach to clinical management may be needed.

  7. Pressure sores and pressure sore prevention in a rehabilitation setting: building information for improving outcomes and allocating resources.

    PubMed

    Baggerly, J; DiBlasi, M

    1996-01-01

    Quantifiable information regarding pressure sore prevention and management is a prerequisite for program development, outcome evaluation, and resource allocation. In this study, all patients admitted to an acute rehabilitation setting (N = 446) during a 2-month period were assessed for the presence of a pressure sore, the risk for developing a pressure sore, the rate of agreement between "objective" (Braden scale) and "subjective" (standard nursing admission data) measures of risk and outcome, and the status of pressure sores at discharge. This article provides the details of the project and implications for rehabilitation nursing practice.

  8. New concepts in the prevention of pressure sores.

    PubMed

    Bogie, Kath; Powell, Heather L; Ho, Chester H

    2012-01-01

    Pressure sores are a serious, and costly, complication for many patients with reduced mobility and sensation. Some populations, such as those with spinal cord injury (SCI), remain at high risk throughout their lifetime. Prevention is highly preferable and while the concept is readily definable, it is much more challenging to develop valid preventative measures. Subjective and objective approaches to risk factor assessment before pressure sores develop are reviewed, including risk status scales and emerging techniques to assess deep tissue injury. Devices to prevent pressure sores have traditionally focused on pressure-relieving cushions and mattresses. Technological advances being applied in the development of new pressure sore prevention devices are presented. Clinical evidence-based practice is integral to pressure sore prevention. Comprehensive assessment must include evaluation of systemic diseases, anatomical and physiological factors, together with environmental and psychosocial factors, which can all contribute to pressure sore development. Extrinsic factors need to be considered in conjunction with intrinsic tissue health factors and are reviewed together with an evaluation of currently available clinical practice guidelines. This chapter presents the broad diversity of factors associated with pressure sore development and highlights the need for an interdisciplinary team approach in order to maximize successful prevention of pressure sores. Copyright © 2012 Elsevier B.V. All rights reserved.

  9. Tissue electrical properties monitoring for the prevention of pressure sore.

    PubMed

    Ching, Congo Tak-Shing; Chou, Mei-Yun; Jiang, Siou-Jhen; Huang, Su-Hua; Sun, Tai-Ping; Liu, Wei-Hao; Liu, Chia-Ming

    2011-12-01

    Pressure sores are a significant problem in the healthcare sector. Although they may cause considerable morbidity, they are preventable. The objectives of this study are to (1) investigate the electrical properties of a tissue close to and away from the pressure sore site, and (2) establish a new approach for objective, reliable, low-cost and noninvasive screening or detection of pressure sore in its early stage. Randomised controlled trial. Fifteen patients participated in this study. They all had stage I or stage II sacral pressure sores. Tiny surface electrodes in four-electrode configuration were used for all tissue electrical properties measurements recorded over the frequency range of 30-10 MHz. Intraclass correlation coefficient (ICC) showed that all measurements (ICC > 0.90 for all measurements) had good reliability and validity. The real part of impedance (R) and the imaginary part of impedance (X) of a tissue measured close to the pressure sore site was found to be significantly smaller (p < 0.05 in all cases) than that measured away from the pressure sore site at a specific frequency range (R: 30.00-38.55 Hz; X: 43.95-606.40 Hz). It was also found that the extracellular resistance (R(e)) and the ratio of extracellular resistance to intracellular resistance (R(e)/R(i)) of a tissue measured close to the pressure sore site were significantly smaller (p < 0.05 in all cases) than that measured away from the pressure sore site. Since the electrical properties (R, X, R(e), R(e)/R(i) ) of a tissue close to, and away from, the pressure sore site can be significantly distinguished, a potentially promising method for the screening of pressure sores at an early stage has been proposed.

  10. [Experience in the treatment of severe pressure sore].

    PubMed

    Xu, Xi-Sheng; ma, Zheng-Zheng; Zhou, Yong-Sheng; Ou, Cai-Sheng; Cheng, Yong; Chen, Kai; Li, Bo-Tong; Zhou, Hai-Yang; Hu, Yong-Cai

    2011-11-01

    To summarize the experience in the treatment of severe pressure sore. From Aug. 2007 to Jun. 2011, 21 cases of severe pressure sore with 43 III-IV degree lesions were treated with combination treatment, including vacuum sealing drainage technique, local fascia flaps, upper or lower gluteus maximus island myocutaneous flaps, lower gluteus maximus myocutaneous flap, neurocutaneous femoris posterior flaps, tensor fascia lata island myocutaneous flaps, free latissimus dorsi myocutaneous flaps, and skin graft, combined with stryker frame and nursing tracking guidance. 13 of 21 cases had multiple pressure sore. Among them, 5 III degree pressure sores were covered by skin grafting and 3 non-caudal III degree pressure sores (< 2 cm in width) were directly closed after debridement. 8 of 21 cases had single IV degree pressure sore. All the 43 wounds healed completely. 5 wounds in 3 cases had effusion under flap which healed after re-drainage. The wounds were not healed in 3 cases with flap transposition which were also healed after re-debridement. All the flaps survived completely. 16 cases were followed up for 2-26 months. Recurrence happened in 4 cases after discharge because of not following the required nursing care. Comprehensive application of vacuum sealing drainage technique, multiple myocutaneous flaps and skin grafting, combined with stryker frame and nursing tracking guidance after discharge can be used for the treatment of severe pressure sore with satisfactory results.

  11. Can electric beds aid pressure sore prevention in hospitals?

    PubMed

    Hampton, S

    The purchase, cleaning and maintenance of air mattresses can be an expensive part of pressure sore prevention and repositioning of patients can be time consuming and costly in terms of possible nursing injuries. The King's Fund bed has been a friend to the health service for many years but the time has come to look for an alternative system that will support patient comfort and independence, will assist nurses in implementation of a no-lifting policy and aid pressure sore prevention policies. This article describes a study that was undertaken in two medical wards to assess the value of electrically controlled beds in relation to the prevention of pressure sores, implementation of a no-lifting policy and quality of patient care. A total of 782 patients took part in the study over a 6-month period and 726 replies were obtained from nurses. The ward had similar profiles of patients' medical conditions and age; they were being medically managed by the same consultants. Results showed that patients experienced greater comfort on beds with the electric facility, produced less pressure sores, mobilized easily and pressure sore prevention costs could be reduced. There is a need to be proactive in prevention of pressure sores and not reactive to a pressure sore that is already developing.

  12. An unusual pressure sore of the nasal bridge.

    PubMed

    Sleilati, Fadi H; Stephan, Henri A; Nasr, Marwan W; Riachy, Moussa A

    2008-07-01

    We report an unusual pressure sore of the nasal bridge caused by a non-invasive ventilation mask. Conservative treatment was unsuccessful, and the defect had to be repaired, with a good postoperative result.

  13. [Six treatment principles of the basle pressure sore concept].

    PubMed

    Rieger, U; Scheufler, O; Schmid, D; Zweifel-Schlatter, M; Kalbermatten, D; Pierer, G

    2007-06-01

    The treatment of pressure sores has gained importance due to the increase of geriatric patients and general life expectancy as well as improved therapeutic options in patients with spinal cord injuries. The aetiology of pressure sores is multifactorial. Risk factors such as immobility, malnutrition, and other co-morbidities have to be considered. Therapy of pressure sores is time- and cost-consuming and recurrence rates are high. Successful treatment is based on the interdisciplinary cooperation between conservative and surgical disciplines, nursing, as well as on continuous patient education. The Basle pressure sore concept consists of six principles. Over a total treatment period of approximately three months usually two operative interventions are performed. For effective relief of pressure (1st principle) patients are placed on low-airloss beds. Operative debridement of pressure sores is performed early and systemic or local infection is treated (2nd principle). The wound is then conditioned with moist dressings or VAC (3rd principle). Simultaneously concomitant malnutrition is quantified clinically and chemically and treated by oral or, if necessary, parenteral nutrition. Other risk factors are optimised as well as possible (4th principle). Hereby optimal conditions for plastic-surgical coverage are provided (5th principle). Postoperatively a standardised concept of pressure relief and mobilisation is adhered to (6th principle). This multimodal treatment concept is well established at the University Hospital of Basle for many years. Combined with an effective prevention, the rate of pressure sores could be significantly reduced, wounds could be healed, and the number of recurrences diminished. In a two-year period between January 2004 and December 2005 the Basle plastic surgery team treated 170 pressure sores in 142 patients according to this concept in the Swiss paraplegic centre in Nottwil. In 2006, 78 % of these patients (111 patients) were followed up and

  14. Beds, mattresses and cushions for pressure sore prevention and treatment.

    PubMed

    Cullum, N; Deeks, J; Sheldon, T A; Song, F; Fletcher, A W

    2000-01-01

    To assess the effectiveness of pressure relieving beds, mattresses and cushions (support surfaces) in the prevention and treatment of pressure sores. Searches of 19 databases, hand searching of journals, conference proceedings, and bibliographies. Randomised controlled trials evaluating support surfaces for the prevention or treatment of pressure sores. There was no restriction on articles based on language or publication status. Data extraction and assessment of study quality was undertaken by two reviewers independently. Trials with similar patients, comparisons, and outcomes were pooled. Where pooling was inappropriate, trials are discussed in a narrative review. 29 RCTs of support surfaces for pressure sore prevention were identified. Some high specification foam mattresses were more effective than 'standard' hospital foam mattresses in moderate-high risk patients. Pressure relieving mattresses in the operating theatre reduced the incidence of pressure sores post-operatively. The relative merits of alternating and constant low pressure, and of the different alternating pressure devices are unclear. Seat cushions and simple, constant low-pressure devices have not been adequately evaluated. Limited evidence suggests that low air loss beds reduce the incidence of pressure sores in intensive care. 6 RCTs of support surfaces for pressure sore treatment were identified. There is good evidence that air-fluidised and low air loss beds improve healing rates. Seat cushions have not been adequately evaluated. 2 RCTs evaluated surfaces for both prevention and treatment in the same trial. PREVENTION - There is good evidence of the effectiveness of high specification foam over standard hospital foam, and pressure relief in the operating theatre. Treatment - There is good evidence of the effectiveness of air-fluidised and low air loss devices as treatments. Overall, however, it is impossible to determine the most effective surface for either prevention or treatment.

  15. Nursing aspects of pressure sore prevention and therapy.

    PubMed

    Culley, F

    Pressure sores remain a significant problem in hospitals and domestic settings, affecting people of all ages, social class and race. Associated complications may be life threatening, e.g. sepsis and osteomyelitis. Other less dangerous, but nevertheless compromising outcomes such as pain, discomfort and low self-esteem and body image can cause personal suffering, and may add extra demand for limited resources. The exact state of pressure sore occurrence remains difficult to determine, particularly in the community. Recent trends in pressure area management present a multidisciplinary approach, eroding traditional perceptions of pressure sores as a solely nursing problem. Written from nursing perspective, this article summarizes principles of good practice relating to pressure sore prevention and therapy, emphasizing the importance of documenting observed events, rather than assumptions or opinions, and the need for healthcare professionals to approach problems and needs from a collaborative stance. Pressure sore risk assessment and classification are discussed, and an overview of nutrition, moving a handling, selecting support surfaces, principles of wound management, and skin care are considered.

  16. Modified lumbar artery perforator flaps for gluteal pressure sore reconstruction.

    PubMed

    Yoon, Chi Sun; Yim, Ji Hong; Kim, Min Ho; Ha, Won; Kim, Kyu Nam

    2016-03-21

    Gluteal perforator flaps (GPFs) are the most useful for gluteal region pressure sore reconstruction. However, application is difficult if the surrounding area has scar tissue from previous operations or trauma, especially with recurrent sores. We describe the use of modified lumbar artery perforator flaps when GPFs cannot be used. Between May 2009 and April 2014, 51 patients underwent gluteal pressure sore reconstructions with gluteal (n = 39) or modified lumbar artery (n = 12) perforator flaps. Patients in the modified lumbar artery perforator group had scar tissue from trauma or previous surgery. In this retrospective review, we analyzed patient age and sex, defect size and location, operative time, follow-up duration, immediate postoperative issues, flap necrosis, dehiscence, re-operation, donor-site morbidity and recurrence. Complications and clinical outcomes were compared between groups. We found no significant differences in patient demographics, surgical complications or clinical outcomes. There were eight cases of temporary congestion (20.51%) and four of partial flap necrosis (10.25%) in the gluteal perforator group. In the modified lumbar artery perforator group, there were three cases of temporary congestion (25%) and one of partial flap necrosis (8.33%). No pressure sores recurred during follow-up in either group. GPFs are the gold standards for gluteal pressure sores, but modified lumbar artery perforator flaps are relatively easy and useful when GPFs cannot be used due to scar tissue. © 2016 Royal Australasian College of Surgeons.

  17. Medial circumflex femoral artery flap for ischial pressure sore

    PubMed Central

    Palanivelu, S.

    2009-01-01

    A new axial pattern flap based on the terminal branches of the medial circumflex femoral artery is described for coverage of ischial pressure sore. Based on the terminal branches of the transverse branch of medial circumflex femoral artery, which exit through the gap between the quadratus femoris muscle above and the upper border of adductor magnus muscle below, this fascio cutaneous flap is much smaller than the posterior thigh flap but extremely useful to cover ischeal pressure sores. The skin redundancy below the gluteal fold allows a primary closure of the donor defect. It can also be used in combination with biceps femoris muscle flap. PMID:19881020

  18. [Clinical typing and surgical principle of pressure sore].

    PubMed

    Liu, Yi; Zhang, Xusheng; Zhang, Cheng

    2007-09-01

    To investigate the clinical typing and their relevant surgical treatment principle and method of pressure sore. From January 1983 to April 2006, 122 patients with 179 pressure sores were treated. There were 93 males and 29 females, aging 15-68 years. The pressure sores were located at sacrococcygeus (54 lesions), petrochanteric region (37 lesions), ischial tuberosity (30 lesions), heel (17 lesions), olecranon (15 lesions), scapula (9 lesions), lateral malleolar (7 lesions), caput fibulace (4 lesions), pretibial (3 lesions), and lumbar region (3 lesims) respectivly. The disease course was from 2 months to 11 years. The areas of pressure sores were from 1.5 cm x 1.0 cm to 20.0 cm x 18.0 cm. According to the wound characteristics, the pressure sores were divided into three types: sinus type (12/179), ulcer type (74/179) and mixed type (93/179). Aimed at different types of pressure sore, skin grafting, skin flap and myocutaneous flap were employed to repair wound. The areas of flaps were from 5.0 cm x 3.5 cm to 26.0 cm x 14.5 cm. The areas of skin grafting were from 7 cm x 5 cm to 23 cm x 12 cm. All wounds of sinus type healed by first intention except one; and all flaps survived. All wounds of uler type healed by first intention; and the flaps survived completely except two which had a partial necrosis. All flaps which harvested to repair 93 pressure sores of mixed type were survived. But one or two sinus occurred in 8 cases. Two healed by operation, and the others healed by dressing exchange. The wounds healed by first intention. The donor sites healed by first intention. The routine follow-up in 73 patients after 6 months showed that the recurrence appeared in 4 mixed type. The recurrence rate was 5.5% and the other patients had good outcome. Clinical typing of pressure sore is helpful to select the suitable operation method and improve the rate of success.

  19. Pressure sores in intensive care: defining their incidence and associated factors and assessing the utility of two pressure sore risk assessment tools.

    PubMed

    Boyle, M; Green, M

    2001-02-01

    Patients in intensive care units (ICU) are at high risk of developing pressure sores and the use of pressure sore risk tools has been advocated as a means of identifying patients at risk. A prospective multi-site observational study was conducted to define the incidence of pressure sores, assess two pressure sore risk scales and to define risk factors relevant to intensive care. Patients (n = 534) were assessed for the presence of pressure sores. The Waterlow and Jackson/Cubbin risk scales were completed each day for 314 and 188 of these patients respectively. A total of 75 pressure sores were recorded. Of these, 34 were present on admission. Of the remaining 41, 16 were classified as Grade 1 and 24 as Grade 2 sores. The pressure sore (PS) incidence was 5.2 per cent. Expressed as PS/1000 patient days there were 18.48 pressure sores per 1000 patient days. The ability of the risk scores to predict pressure sores was tested using a Receiver Operating Characteristic (ROC) analysis. The association of risk score with pressure sores was analysed using a survival function (Kaplan Meier) and variables compared using a logrank test (Mantel-Cox). Factors associated with pressure sore occurrence were developed and tested using a survival regression model. Both risk scales were poor predictors of pressure sores (ROC curve area approximately 70 per cent for both). The factors, coma/unresponsiveness/paralysed & sedated and cardiovascular instability were significantly associated with pressure sores with relative risks of 4.2 and 2.5 respectively. Risk increased as a function of time such that the cumulative risk was 50 per cent at 20 days.

  20. Bed surfaces and pressure sore prevention: an abridged report.

    PubMed

    Brown, S J

    2001-01-01

    This article summarizes the results of a systematic review of randomized controlled trials testing the effectiveness of special beds, mattresses, and cushions in preventing and treating pressure sores. The review's citation is Cullum, N., Deeks, J., Sheldon, T.A., Song, F., & Fletcher, A.W. (2000). Beds, mattresses and cushions for pressure sore prevention and treatment (Cochrane Review). The Cochrane Library, 4. An integrative research review. 37 studies were included in the analysis. A broad search of databases and unpublished studies was conducted. Data were extracted from those that met the inclusion criteria. Studies were grouped in various ways but mainly by type of product evaluated. Many special products designed to prevent or treat pressure sores are more effective than standard hospital foam mattresses in preventing and treating pressure sores. Special pressure-relieving surfaces should be used for patients at risk for skin breakdown. Individual practitioners and agencies should have a systematic protocol for assessing patients' risk of skin breakdown and for taking action when patients are determined to be at risk. The findings of this review provide some guidance for choosing particular products, albeit not definitive evidence for matching risk levels to products.

  1. Pedicled fillet of leg flap for extensive pressure sore coverage.

    PubMed

    Jandali, Shareef; Low, David W

    2009-10-27

    Multiple large decubitus ulcers present a reconstructive challenge to the plastic surgeon. When stage IV pressure sores become recurrent or extensive, traditional flaps either have already been exhausted or would not be sufficient to cover the defect. A retrospective review was performed on all paraplegic patients who had chronic, extensive, and stage IV decubitus ulcers, and underwent reconstruction using a pedicled continuous musculocutaneous flap of the entire leg between 1998 and 2007. The extent and size of the debrided pressure sores, number of previous flap reconstructions, intraoperative blood loss, postoperative complications, and years of follow-up were all recorded. A description of the operative technique is also given. Four patients underwent a total leg fillet flap in the study period, with follow-up ranging from 2 to 7 years. Indications included extensive and bilateral trochanteric, sacral, and ischial pressure sores. Complications included intraoperative blood loss and postoperative heterotopic calcification. The total leg fillet flap is a very large and robust flap that offers paraplegic patients coverage of extensive stage IV pressure sores of the trochanteric, sacral, and ischial areas.

  2. [An assessment scale for the prevention of pressure sores in children].

    PubMed

    Chauvet, Corinne; Poirier, Marie-Renée; Sourisseau, Petronela Rachieru; Béduneau, Denis; Soulard, Anthony; Delacroix, Delphine

    2015-04-01

    Pressure sores in children are rare. However, when they do occur they can have significant consequences. Professionals in paediatric units realised the importance of assessing the risk of pressure sores and developed a pressure sore assessment scale specific to children. This project, carried out through a hospital-training school partnership, emphasises the importance of clinical reasoning in nursing practices.

  3. Electrical stimulation for pressure sore prevention and wound healing.

    PubMed

    Bogie, K M; Reger, S I; Levine, S P; Sahgal, V

    2000-01-01

    This paper reviews applications of therapeutic electrical stimulation (ES) specific to wound healing and pressure sore prevention. The application of ES for wound healing has been found to increase the rate of healing by more than 50%. Furthermore, the total number of wounds healed is also increased. However, optimal delivery techniques for ES therapy have not been established to date. A study of stimulation current effects on wound healing in a pig model has shown that direct current (DC) stimulation is most effective in wound area reduction and alternating current (AC) stimulation for wound volume reduction at current densities of 127 microA/cm2 and 1,125 microA/cm2, respectively. Preliminary studies have been carried out at two research centers to assess the role of ES in pressure sore prevention. Surface stimulation studies have shown that ES can produce positive short-term changes in tissue health variables such as regional blood flow and pressure distribution. The use of an implanted stimulation system consisting of intramuscular electrodes with percutaneous leads has been found to produce additional long-term changes. Specifically, gluteal muscle thickness increased by 50% with regular long-term ES application concurrent with a 20% decrease in regional interface pressures and increased tissue oxygen levels. These findings indicate that an implantable ES system may have great potential for pressure sore prevention, particularly for individuals who lack sensation or who are physically unable to perform regular independent pressure relief.

  4. Pressure-induced referred pain is expanded by persistent soreness.

    PubMed

    Doménech-García, V; Palsson, T S; Herrero, P; Graven-Nielsen, T

    2016-05-01

    Several chronic pain conditions are accompanied with enlarged referred pain areas. This study investigated a novel method for assessing referred pain. In 20 healthy subjects, pressure pain thresholds (PPTs) were recorded and pressure stimuli (120% PPT) were applied bilaterally for 5 and 60 seconds at the infraspinatus muscle to induce local and referred pain. Moreover, PPTs were measured bilaterally at the shoulder, neck, and leg before, during, and after hypertonic saline-induced referred pain in the dominant infraspinatus muscle. The pressure and saline-induced pain areas were assessed on drawings. Subsequently, delayed onset muscle soreness was induced using eccentric exercise of the dominant infraspinatus muscle. The day-1 assessments were repeated the following day (day 2). Suprathreshold pressure stimulations and saline injections into the infraspinatus muscle caused referred pain to the frontal aspect of the shoulder/arm in all subjects. The 60-second pressure stimulation caused larger referred pain areas compared with the 5-second stimulation (P < 0.01). Compared with pressure stimulation, the saline-induced referred pain area was larger (P < 0.02). After saline-induced pain, the PPTs at the infraspinatus and supraspinatus muscles were reduced (P < 0.05), and the 5-second pressure-induced referred pain area was larger than baseline. Pressure pain thresholds at the infraspinatus and supraspinatus muscles were reduced at day 2 in the delayed onset muscle soreness side (P < 0.05). Compared with day 1, larger pressure and saline-induced referred pain areas were observed on day 2 (P < 0.05). Referred pain to the shoulder/arm was consistently induced and enlarged after 1 day of muscle soreness, indicating that the referred pain area may be a sensitive biomarker for sensitization of the pain system.

  5. Perforator-based fasciocutaneous flap for pressure sore reconstruction.

    PubMed

    Lin, Chih-Hsun; Ma, Hsu

    2012-12-01

    Pressure sore reconstruction is always a challenge for plastic surgeons due to its high recurrence rate. In addition to the myocutaneous flap, the perforator-based fasciocutaneous flap has become a new entity used for pressure sore reconstruction. This study presents a series of 26 perforator-based fasciocutaneous flaps for pressure sore reconstruction, with good outcomes in 21 patients from July 2008 to April 2011. The flaps were advanced, transposed, or rotated to obliterate the defects. Twenty of 26 flaps healed uneventfully without complication. One patient had a flap that totally necrosed, one had partial flap necrosis (flap rotated 180° in the above two cases), one had infection and healed by a secondary flap, one had minor wound dehiscence, one died of pneumonia 1 week postoperatively, and recurrence developed in one patient. The perforator-based fasciocutaneous flap is a reliable method and produced good results in this series. These flaps are well vascularised, have enough soft tissue bulk, and have a high degree of mobilisation freedom.

  6. Development of a cushion to prevent ischial pressure sores.

    PubMed Central

    Bowker, P; Davidson, L M

    1979-01-01

    A study was carried out jointly by nursing staff and technologists in an attempt to develop a cushion based on scientific principles and measurement that might prevent pressure sores. At each stage in the development clinical trials were carried out, and using the results of these together with the opinions of medical staff and patients who used the cushion the design was suitably modified. Over four years a seat was evolved that was simple to construct and fulfilled the clinical requirements for a wide range of patients while providing maximum relief of high-pressure points. The design was subsequently taken up commercially. Images Fig 3 PMID:509176

  7. Prevention is better than cure. A survey of the use of Pegasus Airwave System in pressure sore treatment.

    PubMed

    Winman, G; Ashley, L

    1992-12-01

    Pressure relieving mattresses play an important role in pressure sore prevention and healing. This study describes the current use and reported effectiveness of the Pegasus Airwave System in pressure sore prevention.

  8. Nutritional status, pressure sores, and mortality in elderly patients with cancer.

    PubMed

    Waltman, N L; Bergstrom, N; Armstrong, N; Norvell, K; Braden, B

    1991-07-01

    This prospective study aimed to determine differences in nutritional status, incidence of pressure sores, and incidence of mortality between two groups, one composed of 33 elderly, institutionalized patients with cancer and the other a matched group of 33 patients without cancer. Subjects with cancer were paired with subjects without cancer based on age (mean = 78), sex, and pressure sore risk. Skin breakdown, dietary intake, and blood and serum indices of nutritional status were studied for 12 weeks. Of the subjects with cancer, 85% developed pressure sores, compared to 70% of the subjects without cancer. Hemoglobin (Hgb) (female), serum total protein, total lymphocyte count, serum albumin, serum total iron binding capacity, and serum transferrin were significantly lower in subjects with cancer with pressure sores than in subjects without cancer with pressure sores. Total lymphocyte count and serum total protein were significantly lower in subjects with cancer with pressure sores than in subjects with cancer without pressure sores. Kwashiorkor was found in 70% of the subjects with cancer, compared to 21% of the subjects without cancer. During the study, 39% of the subjects with cancer and 15% of the subjects without cancer died. All 13 of the subjects with cancer who died had kwashiorkor and pressure sores and had died an average of three weeks after developing pressure sores. These results implicate that elderly patients with cancer who have protein deficiencies should be considered to be at risk of pressure sore development. Frequent repositioning and mattress overlays that reduce pressure and increase comfort may delay development of pressure sores.(ABSTRACT TRUNCATED AT 250 WORDS)

  9. Total bed management: the way forward in pressure sore prevention.

    PubMed

    Preece, J

    King's College Hospital, London, is the first trust to implement total bed management (TBM) to assist in the reduction and prevention of pressure sores. TBM is a new concept, whereby the tissue viability, manual handling and therapy needs of the trust are met at reduced costs through a partnership with a contractor. The introduction of a large number of electric bed frames and foam mattress replacements, with the availability of dynamic pressure-relieving equipment and a service agreement, has led to an expected trust saving of 86,000 Pounds in 1998/1999 and 100,000 Pounds in 1999/2000 onwards. This article outlines the perceived benefits of this approach.

  10. [Resurfacing of an ischial and trochanteric recurrent pressure sore by a pedicled fasciocutaneous anterolateral thigh flap].

    PubMed

    Moullot, P; Philandrianos, C; Casanova, D

    2014-10-01

    Ischial pressure sores, common in paraplegic patient, are the most difficult to treat, and poor prognosis associated with a high rate of postoperative recurrence. Many surgical techniques by muscular or myocutaneous flap coverage have been described. We report an original use of a fasciocutaneous pedicled anterolateral thigh (ALTp) flap for coverage of an ischial pressure sore combined with a trochanteric pressure sore, exceeded beyond any conventional therapeutic solution. A 45-year-old paraplegic patient suffered from a trochanteric and ischial pressure sore, which had already received coverage by a muscular flap of biceps femoris and gluteus maximus. At 1 year, the result is satisfactory, with good coverage without recurrence. The fasciocutaneous ALTp flap can be a solution to cover recurrent ischial pressure sores beyond conventional methods. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  11. Risk factors for pressure sores in adult patients with myelomeningocele – a questionnaire-based study

    PubMed Central

    Plaum, Pål-Erik; Riemer, Gunnar; Frøslie, Kathrine Frey

    2006-01-01

    Background Myelomeningocele (MMC) is a part of a complex neural tube defect and a disorder of the cerebrospinal fluid system. Pressure sores are a frequent complication for patients with MMC. Little is known about the risk factors for pressure sores in adults with MMC. The aim of this study was to investigate an association between the presence of pressure sores and other patient characteristics, in order to develop an improved strategy for the management of sores. Methods A structured questionnaire regarding sores, medical condition, function and living factors was designed and sent to the 193 patients with MMC registered in the year 2003 at TRS, a National Centre for Rare Disorders in Norway. Results Out of 193 total, 87 patients participated and 71 patients (82%) reported sores; 26 (30%) at the time of the interview and 45 (52%) during the last 5 years. Sores were mostly localized on toes and feet and occurred exclusively in regions with reduced or missing sensibility. A significant association was found between sores and memory deficit (p = 0.02), Arnold Chiari malformation (p = 0.02) and a record of previous sores (p = 0.004). Sores were not significantly associated with hydrocephalus, syringomyelia, nutrition, body mass index, smoking, physical activity, employment or living together with other persons. Some patients (18, 21%) reported skin inspection by others and the remainder relied on self-inspection. Conclusion Patients with sensory deficit, memory problems, and Arnold Chiari malformation had a higher risk of having pressure sores. This patient group needs improved skin inspection routines and sore treatment. PMID:17196099

  12. [The Development of a Care Protocol for Postoperative Pressure Sore Prevention].

    PubMed

    Huang, Yu-Ling; Lin, Hui-Ling; Wang, Fang; Wu, Shu-Fang Vivienne

    2015-12-01

    Pressure sores are a common complication caused by long periods of bed rest following major surgery. These sores may increase patient postoperative pain, increase the risk of infections, lengthen the pe-riod of hospitalization, and increase the duration and costs of nursing care. Therefore, maintaining the skin integrity of surgical patients is an important responsibility for operating room nurses and an indicator of nursing care quality. While pressure-sore risk assessment tools and interoperative strategies are available and used in foreign countries, there has been little related research conducted in Taiwan. After examining the relevant literature and considering the current postoperative pressure sore situation in Taiwan, the author developed a postoperative pressure sore care protocol as a reference for clinical staff. Protocol procedures include major breakthrough developments in areas such as post-survey risk assessment for pressure ulcers, pressure ulcer prevention strategies that take surgery-related risk factors into consideration, extra care and protection measures for surgical supine patients, and post-pressure sores. The developed postoperative pressure sore protocol may be incorporated into surgical care procedures during the post-surgical care period in order to effectively prevent the occurrence of post-surgery pressure ulcers. Furthermore, the developed protocol offers the potential to improve and strengthen the quality of surgical care in terms of both healthcare and post-surgical care.

  13. Impact of laryngeal mask airway cuff pressures on the incidence of sore throat in children.

    PubMed

    Wong, Justin Gin Leong; Heaney, Mairead; Chambers, Neil A; Erb, Thomas O; von Ungern-Sternberg, Britta S

    2009-05-01

    Hyperinflation of laryngeal mask airway cuffs can cause harm to the upper airway mainly by exerting high pressures on pharyngeal and laryngeal structures thus impairing mucosal perfusion. Although cuff manometers can be used to guide the monitoring of cuff pressures, their use is not routine in many institutions. In a prospective audit, we assessed the incidence of sore throat following day-case-surgery in relation to the intracuff pressure within the laryngeal mask airway. Four hundred children (3-21 years) were consecutively included in this study. The laryngeal mask airway was inflated as deemed necessary by the attending anesthetist. Cuff pressures were measured using a calibrated cuff manometer (Portex Limited, Hythe, Kent, UK, 0-120 cm H2O, pressures exceeding the measurement range were set at 140 cm H2O for statistical purposes) at induction of anesthesia. Forty-five children (11.25%) developed sore throat, 32 (8%) sore neck and 17 (4.25%) sore jaw. Of those that developed sore throat, 56.5% had cuff pressures exceeding >100 cm H2O. In contrast, when cuff pressures were <40 cm H2O, there were no episodes of sore throat, whilst there was only a 4.6% occurrence of sore throat if cuff pressures were between 40-60 cm H2O. We have demonstrated that intra cuff pressure in laryngeal mask airways is closely related to the development of sore throat with higher pressures increasing its likelihood. Hence, cuff pressures should be measured routinely using a manometer to minimize the incidence of sore throat.

  14. Marjolin's Ulcer Complicating a Pressure Sore: The Clock is Ticking.

    PubMed

    Khan, Kamran; Giannone, Anna Lucia; Mehrabi, Erfan; Khan, Ayda; Giannone, Roberto E

    2016-02-22

    Malignant degeneration in any chronic wound is termed a Marjolin's ulcer (MU). The overall metastatic rate of MU is approximately 27.5%. However, the prognosis of MU specific to pressure sores is poor, with a reported metastatic rate of 61%. This is due to insidious, asymptomatic malignant degeneration, a lack of healthcare provider awareness, and, ultimately, delayed management. An 85-year-old white male was noted by his wound-care nurse to have a rapidly developing growth on his lower back over a period of 4 months. There was history of a non-healing, progressive pressure ulcer of the lower back for the past 10 years. On examination, there was a 4 × 4 cm pressure ulcer of the lower back, with a superimposed 1.5 × 2 cm growth in the superior region. There was an absence of palpable regional lymphadenopathy. Punch biopsy revealed squamous cell carcinoma consistent with Marjolin's ulcer. The ulcer underwent excision with wide margins, and a skin graft was placed. Due to the prompt recognition of an abnormality by the patient's wound-care nurse, metastasis was not evident on imaging. There are no signs of recurrence at 1-year follow-up. Marjolin's ulcer has a rapid progression from local disease to widespread metastasis. Therefore, it is essential that wound-care providers are aware of the clinical signs and symptoms of malignant degeneration in chronic wounds.

  15. Nutritional status and evolution of pressure sores in geriatric patients.

    PubMed

    Donini, L M; De Felice, M R; Tagliaccica, A; De Bernardini, L; Cannella, C

    2005-01-01

    The prevalence of pressure sores (PS) ranges from 1 to 18% of in-patients and from 3 to 28% of those admitted to long-term settings. The aim of our study was to verify, a posteriori, how nutritional status influenced the evolution of PS in a population of elderly subjects hospitalised in a long-term care setting. The charts of 125 patients with ulcerative or necrotic pressure ulcers were evaluated retrospectively. For each subject we took note of: PS characteristics (stage, ulcer surface, evolution), clinical characteristics (comorbidity, adverse clinical events, cognitive, functional and nutritional status). In 58 patients (46.4%) there was overall healing of the lesions while in 39 patients (31.2%) we had however an "improvement" of PS. The course of PS was not significantly influenced by the patient's physiological characteristics, by cognitive status or by initial characteristics of PS. Instead, we noticed a significant difference in the course of PS as a function of the level of autonomy and clinical status. The course of PS, and in particular the Healing Index, were influenced by the Nutritional Status and, above all, by its course during the treatment period. The development of PS is multifactorial. Whereas, it is clear that factors other than nutrition influence the risk of developing PS, an important role for nutrition in the development and resolution of PS is suggested. Our data certainly confirm the "Quality indicators for prevention and management of pressure ulcers in vulnerable elders", especially were they say "if a vulnerable elder is identified as at risk for pressure ulcer development and has malnutrition, then nutritional intervention or dietary consultation should be instituted because poor diet, particularly low dietary protein intake, is an independent predictor of pressure ulcer development".

  16. Sacral pressure sore reconstruction -- the pedicled superior gluteal artery perforator flap.

    PubMed

    Hurbungs, A; Ramkalawan, H

    2012-02-14

    To report the use of the pedicled superior gluteal artery perforator (SGAP) fasciocutaneous flap as a reliable surgical option for sacral pressure sore reconstruction. A prospective study was conducted between September 2008 and September 2010 of 10 patients with stage 3 or 4 sacral pressure sores treated with a unilateral pedicled SGAP flap. All flaps survived completely with no complications in 9 patients. One patient had a haematoma below the flap that was easily drained. No recurrence of the bedsore occurred during follow-up. We suggest that the pedicled SGAP fasciocutaneous flap is a reliable surgical option for sacral pressure sore reconstruction.

  17. An ideal method for pressure sore reconstruction: a freestyle perforator-based flap.

    PubMed

    Yang, Ching-Hsiang; Kuo, Yur-Ren; Jeng, Seng-Feng; Lin, Pao-Yuan

    2011-02-01

    Pressure sore reconstruction is quite difficult for plastic surgeons because of long-term high recurrence rates. We designed a freestyle perforator-based flap for pressure sore reconstruction considering pressure sore recurrence and further reconstruction. We used a handheld Doppler device to locate a perforator position just adjacent to the pressure ulcer. In a series of 34 patients, we used 37 perforator-based flaps to reconstruct 25 sacral, 5 ischial, and 4 trochanteric ulcers. Twenty-eight of 37 flaps healed uneventfully without complication. One patient had a flap that totally necrosed, 3 had partial flap necrosis, 3 had wound dehiscence, 1 died 3 days postoperatively, and recurrence developed in 1 patient. We used the freestyle perforator-based fasciocutaneous flap for pressure sore management with good success. These flaps are easy to design and provide good versatility for coverage. Cooperation of surgical skills and good postoperative care also contributed to the lower recurrence rates and satisfactory results.

  18. Continent urinary diversion and diverting colostomy in the therapy of non-healing pressure sores in paraplegic patients.

    PubMed

    Bejany, D E; Chao, R; Perito, P E; Politano, V A

    1993-04-01

    Immobilization and subsequent sacral decubitus or pressure sore formation is a danger faced by the paraplegic. We report on 4 patients treated with non-healing pressure sores. Three male patients had decubiti eroding into the posterior urethra and bladder neck area. One female patient had bladder neck and urethral loss secondary to Foley catheter erosion and a sacral pressure sore. All 4 had non-healing decubiti secondary to urinary contamination and, in addition, gross fecal contamination in the male patients. All patients failed previous muscular flaps and urinary diversion per suprapubic tube. In the male patients, suprapubic continent urinary diversion included bladder neck mobilization, closure of the distal urethra by oversewing and patching with bovine dura, and augmentation of the bladder with a Miami pouch. Fecal diversion was provided with a sigmoid colostomy. In the female patient, continent diversion was performed by forming a Miami pouch. Total diversion allowed healing of the pressure sores and provided a simpler method of personal hygiene. Details of the diversion and case studies will be presented.

  19. [Giant recurrent trochanteric pressure sore: A complex medico-surgical care].

    PubMed

    Pesenti, S; Ciceron, C; Toledano, E; Niddam, J; Tournebise, H

    2016-12-01

    Pressure sores are a frequent complication in spinal injured people. Their treatment is often long and complex. We report the case of a 60-year-old man affected with complete paraplegia who developed a right trochanteric pressure ulcer complicated with osteoarthritis of the coxofemoral joint. The treatment was done in three steps. First, a large excision of necrotic tissues and a femoral head-neck resection is performed. Then, the defect is partly covered with a Gluteus Maximus and a Biceps Femoris myocutaneous flaps. Finally, the residual defect is covered with a cutaneous pedicled groin flap called McGregor's flap. Later, the patient showed a right para-scrotal pressure sore on a heterotopic ossification of the ischial tuberosity. McGregor's flap is rarely employed for treating trochanteric pressure sores. It was here the only pedicled flap available. It was necessary to autonomize it in order to get enough length and to place a hip external fixation. The para-scrotal pressure sore illustrates the fact that bone resection surgery lifts the weight-bearing zones and can lead to pressure sores in unusual locations. The surgical treatment of these "giant" pressure sores requires a perfect collaboration between teams of rehabilitation and several surgical areas. Without a good adherence of the patient, the treatment is doomed to fail. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  20. Using a modified nasotracheal tube to prevent nasal ala pressure sore during prolonged nasotracheal intubation.

    PubMed

    Cherng, Chen-Hwan; Chen, Yuan-Wu

    2010-12-01

    Nasotracheal tube induced nasal ala pressure sores or necrosis during prolonged nasotracheal intubation have been reported, and it is a serious but preventable complication. Here we introduce a modified nasotracheal tube to prevent this complication. This modified nasotracheal tube is composed of two parts, an oral endotracheal tube and a proximal part of a preformed nasotracheal tube, which are linked by a connector. The use of this modified nasotracheal tube can prevent nasal ala pressure sores during prolonged nasotracheal intubation.

  1. [Indication of sclerotherapy in the treatment of ischiatic pressure sore: about 13 cases].

    PubMed

    Bahé, L; Prud'homme, A; Penaud, A; Formé, N; Zakine, G

    2012-12-01

    Ischiatic pressure sore is a common pathology of the paraplegic patient. Usually treated after medical therapy, with fasciocutaneous or musculocutaneous local flaps, despite this treatment the recurrence rate is high. Sclerotherapy, injection of pure ethanol in the cavity of the pressure sore could be an interesting solution in the armentarium of the plastic surgeon in some indications. Sclerotherapy was used for 13 patients in the plastic surgery department to treat ischiatic pressure sores with a cavity, beneath the defect. The mean length of stay was 24 days. The ischiatic pressure sore was completely healed with no skin defect or cavity for nine patients (65%). For two patients, there was a delay of healing of the skin defect but no cavity beneath. There were two early recurrences of the pressure sore. They were treated by sclerotherapy with a complete recovery in 2 months with simple hydrocolloid dressings. The mean post op follow-up was 14,6 months (4 to 24). Only one recurrence was observed after 12 months. The injection of pure ethanol in the cavity of specifics ischiatics pressure sores is a simple, fast and effective technique with a good and stable long term wound healing. The mean length of stay is shorter and the recurrence rate is equivalent to other techniques. Copyright © 2009 Elsevier Masson SAS. All rights reserved.

  2. [Prevalence and prevention and treatment modalities for pressure sores. Study of the Emilia-Romagna region].

    PubMed

    Melotti, Rita Maria; Fortuna, Daniela; Chiari, Paolo; Cavicchioli, Andrea; Mongardi, Maria; Santullo, Antonella; Grilli, Roberto

    2003-01-01

    This audit initiative aimed at assessing the prevalence of pressure sores in the public hospitals of Emilia-Romagna, and at monitoring the rate of use of specific modalities of prevention and cure. The design was cross-sectional, with information collected on three index days during 2000 by trained personnel. Overall, the prevalence of pressure sores at the regional level was 7.1%, with remarkable variation across hospitals (from 2.9% to 9.7%), also after adjustment for case mix. As for patterns of prevention and cure, 74% of patients at risk (according to the Braden scale) of developing a pressure sores received only standard low technology devices, and 50% of those in need were included in a systematic programme of postural change. Adequate (according to the available evidence) medications were used in 45% of patients with a pressure sore. The overall prevalence of pressure sore is close (or even inferior) to that observed in similar studies. However, variation between hospitals indicates that the current health services ability to deal with pressure sore is variable and often suboptimal. This evaluation is also supported by the limited adoption of adequate preventive and curative modalities.

  3. The evaluation of daily living activities, pressure sores and risk factors.

    PubMed

    Aydın, Gökçen; Mucuk, Salime

    2015-01-01

    This study was conducted to assess daily living activities, pressure sores and risk factors. This was a descriptive study. The study was conducted at a rehabilitation center with 188 individuals participating in the study. Data were collected with a questionnaire form, Activities of Daily Living Scale (ADLS), Instrumental Activities of Daily Living Scale (IADLS) and Braden Risk Assessment Scale (BRAS). Among the participants, 48.9% were dependent according to activities of daily living and 71.8% were dependent on instrumental activities of daily living. It was noted that 4.8% had pressure sores and 38.8% were at high risk. A strong and positive correlation was found among ADLS, IADLS, and BRAS scores (p < .001). Participants who had a low body mass index, had lived at the rehabilitation center for a long time, and were fed on regime 1 or 2, had a higher risk of developing pressure sores (p < .001). Individuals who were dependent according to ADLS and IADLS were at increased risk for the development of pressure sores. Individuals who are treated at rehabilitation centers should be periodically assessed in terms of risk. Pressure sore development can be prevented with appropriate nursing interventions. To reduce the risk of developing pressure sores, nurses should describe the individual's degree of dependency according to ADLS and IADLS and initiate preventive nursing care. © 2014 Association of Rehabilitation Nurses.

  4. A new postoperative management scheme for preventing sacral pressure sores in patients with spinal cord injuries.

    PubMed

    Kato, H; Inoue, T; Torii, S

    1998-01-01

    Although the reliability of pressure sore surgery has improved with the advent of many different types of flaps, it is well known that the recurrence rate of pressure sores is still remarkably high in spinal cord-injured patients. This article reports the very low relapse rate of postsurgical pressure sores using air mattresses, which also helps relieve manpower requirements for care. We measured interface pressures at the sacrum for 18 spinal cord-injured patients with a ROHO air mattress (ROHO International, Inc, Belleville, IL). Based on the results, we used this mattress immediately after surgery for 19 spinal cord-injured patients with sacral pressure sores. Minimal repositioning was performed for each patient during the hospital stay. Minimal repositioning was similarly performed at home. All pressure sores healed, regardless of the type of surgical procedure, size, and degree of sore. No relapse has been found, with an average of 33.4 months after surgery. With this management, we could achieve a very low recurrence rate, require less manpower for postoperative management, as well as minimize stress for the patients.

  5. Local flap therapy for the treatment of pressure sore wounds.

    PubMed

    Wettstein, Reto; Tremp, Mathias; Baumberger, Michael; Schaefer, Dirk J; Kalbermatten, Daniel F

    2015-10-01

    The aim of this study was to analyse the effectiveness of an interdisciplinary cooperation between conservative and surgical disciplines for the treatment of pressure sores (PS). From January 2004 to December 2005, a single-centre study was performed with paraplegic and tetraplegic patients presenting with PS grades III-V. Outcome measures were defect size, grade, method of reconstruction, complication and recurrence rate as well as average length of hospitalisation. A total of 119 patients aged 22-84 years with totally 170 PS were included. The most common PS were located in the ischial region (47%), followed by the sacral (18%), trochanteric (11%), foot (9%) and the malleolar (8%) regions. Defect sizes ranged between 4 and 255 cm(2) . Grade IV was the most common PS (68%), followed by grade III (30%) and grade V (2%) PS. For wound closure, fasciocutaneous flaps were used most frequently (71%), followed by skin grafts (10%) and myocutaneous flaps (7%). Postoperative follow-up ranged between 6 and 38 months. The overall complication and recurrence rate was 26% and 11%, respectively. If no complication occurred, the average duration of hospitalisation stay after the first debridement was 98 ± 62 days. In conclusion, our treatment concept is reliable, effective and results in a low recurrence rate. The complication rate, even though favourable when compared with the literature, still needs to be improved. © 2013 The Authors. International Wound Journal © 2013 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

  6. [Application of tensor fascia lata pedicled flap in reconstructing trochanteric pressure sore defects].

    PubMed

    Karabeg, Reuf; Dujso, Vanis; Jakirlić, Malik

    2008-01-01

    Tensor fascia lata pedicled flap is one of the most useful flaps for reconstruction pressure sore defects on trochanteric region. Debate exists on the safe dimension of the flap, as distal tip necrosis can be encountered. The aim of the current study is to report experience of Clinic for Plastic and Reconstructive Surgery, Clinical University Center of Sarajevo, with tensor fascia lata pedicled flap in reconstructing trochanteric pressure sore defects. From January 1993 to December 2007, 39 pedicled TFL flaps were used for reconstruction trochanteric pressure sore defects in 34 patients. We used 3 local flaps for reconstruction of small trochanteric defects and one direct suture. In our study we had 43 trochanteric pressure sores and in 9 patients pressure sores were bilateral. The age ranged from 9 to 65, with average age 41,2. The resulting trochanteric defects in this study were due to debridement of pressure sore. The size of the flaps used ranged from 15 x 6 cm to 30 x 15 cm. All flaps survived. Distal tip necrosis occurred in 4 cases. All 4 cases developed in a very large flap beyond the safe limits. Wound dehiscence occurs in 3 cases. There was minimal donor side morbidity in the form of partial skin loss in 1 case. The average follow up period in this study ranged from 6 months to 15 years. Tensor fascia lata flap is reliable flap. Donor site morbidity is minimal. Problem with the flap can be encountered if the flap is not harvested with the safe limits and properly designed. Proper preoperative preparations must be taken into consideration. Chronic skin ulcers, such as pressure sores, that are refractory to conventional local wound therapies, are good examples of potential beneficiaries of the TFL musculocutaneous flap.

  7. A reusable perforator-preserving gluteal artery-based rotation fasciocutaneous flap for pressure sore reconstruction.

    PubMed

    Lin, Pao-Yuan; Kuo, Yur-Ren; Tsai, Yun-Ta

    2012-03-01

    Perforator-based fasciocutaneous flaps for reconstructing pressure sores can achieve good functional results with acceptable donor site complications in the short-term. Recurrence is a difficult issue and a major concern in plastic surgery. In this study, we introduce a reusable perforator-preserving gluteal artery-based rotation flap for reconstruction of pressure sores, which can be also elevated from the same incision to accommodate pressure sore recurrence. The study included 23 men and 13 women with a mean age of 59.3 (range 24-89) years. There were 24 sacral ulcers, 11 ischial ulcers, and one trochanteric ulcer. The defects ranged in size from 4 × 3 to 12 × 10 cm(2) . Thirty-six consecutive pressure sore patients underwent gluteal artery-based rotation flap reconstruction. An inferior gluteal artery-based rotation fasciocutaneous flap was raised, and the superior gluteal artery perforator was preserved in sacral sores; alternatively, a superior gluteal artery-based rotation fasciocutaneous flap was elevated, and the inferior gluteal artery perforator was identified and dissected in ischial ulcers. The mean follow-up was 20.8 (range 0-30) months in this study. Complications included four cases of tip necrosis, three wound dehiscences, two recurrences reusing the same flap for pressure sore reconstruction, one seroma, and one patient who died on the fourth postoperative day. The complication rate was 20.8% for sacral ulcers, 54.5% for ischial wounds, and none for trochanteric ulcer. After secondary repair and reconstruction of the compromised wounds, all of the wounds healed uneventfully. The perforator-preserving gluteal artery-based rotation fasciocutaneous flap is a reliable, reusable flap that provides rich vascularity facilitating wound healing and accommodating the difficulties of pressure sore reconstruction. Copyright © 2011 Wiley Periodicals, Inc.

  8. Detection and Isolation of Digital Dermatitis Treponemes from Bovine Pressure Sores.

    PubMed

    Clegg, S R; Crosby-Durrani, H E; Bell, J; Blundell, R; Blowey, R W; Carter, S D; Evans, N J

    2016-05-01

    Pressure sores cause severe pain and discomfort in hospitalized people and in farmed cattle and are often infected with unknown bacteria. Pressure sores occur on the upper legs of 6-10% of recumbent cattle and are generally considered to be caused by constant pressure, commonly on bony areas of the limbs. This study analyzed pressure sores taken from the upper limbs of 14 cattle using isolation in culture and nested polymerase chain reaction (PCR) to detect treponemes associated with digital dermatitis (DD). A 100% association of DD treponemes with the pressure sores was demonstrated, but treponemes were shown not to be part of the normal skin microbiota. Immunohistochemistry showed an association of DD treponemes with lesions and particularly with the hair follicles in lesions, identifying the bacteria deep within wounds, thereby suggesting that they could contribute to lesion pathogenesis. The bacteria isolated from the pressure sore lesions were similar or identical on analysis of the 16S rRNA gene to those found in DD foot lesions in cattle, suggesting the same bacteria can infect multiple lesions. Indeed, the results of this study suggest that these spirochaetal bacteria may be expanding in host range and in their ability to colonize different tissues and contribute to a range of disease manifestations in farm animals.

  9. Does a foamy-block mattress system prevent pressure sores ? A prospective randomised clinical trial in 1729 patients.

    PubMed

    Berthe, J V; Bustillo, A; Mélot, C; de Fontaine, S

    2007-01-01

    Pressure ulcers are a frequent complication of bed rest. The development of an efficient and low cost pressure relieving system for the prevention of bed-sores would be of considerable hospital health and economic interest. Our study was designed to determine the effectiveness in pressure-sore prevention of an interface pressure-decreasing mattress, the Kliniplot mattress, used in our institution since 1978. In a prospective randomised controlled 7-month clinical trial we compared the Kliniplot mattress with our standard hospital mattress in 1729 patients admitted to medical and surgical departments (neurology, cardiology, oncology-haematology, neurosurgery, thoracic surgery and orthopaedic surgery). Two groups (Klinipot mattress and standard hospital mattress) were monitored for the prevention of pressure sores. The patients were evaluated on a daily basis from their admission until the eventual occurrence of a bed-sore. Patients' characteristics and pressure-sore risk factors were similar at the baseline in both groups. Patients presenting with a pressure sore at the time of admission were excluded. Forty-two of the 1729 patients (2.4%) who entered the study developed at least one pressure sore. Twenty-one of the 657 patients (3.2%) nursed on the Kliniplot mattress, and 21 of the 1072 patients (1.9%) on the standard mattress developed bed-sores (p = 0.154). The median time for the occurrence of pressure sores was 31 days (range 6-87) with the Kliniplot mattress and 18 days (range 2 to 38) with the standard mattress (p < 0.001). The risk categories for developing bed-sores using the modified Ek's scale were no different at the baseline between both groups (p = 0.764). The severity of the pressure sores was no different between both groups (p = 0.918). Our results show that the occurrence of pressure sores is not reduced but is delayed when patients are nursed on a Kliniplot pressure-decreasing mattress.

  10. [Clinical characteristics and surgical management of 17 patients with pressure sore of sinus type].

    PubMed

    Liu, Yi; Zhang, Xianying; Xiao, Bin; Song, Mei; Liu, Ping; Jiang, Jiang; Zhang, Cheng; Zhang, Xusheng; Chen, Liming

    2014-08-01

    To sum up the clinical characteristics, surgical management, and effectiveness of pressure sore of sinus type. Between January 2009 and April 2013, 17 patients with 19 pressure sores of sinus type after traumatic paraplegia were treated, and the clinical data were analyzed retrospectively. There were 11 males and 6 females with an average age of 27.4 years (range, 17-49 years). The median disease duration was 1.5 years (range, 6 months to 7 years). Of 17 cases, there were 14 primary cases and 3 recurrent cases; 10 focuses of 8 cases were classified as simple sinus type, and 9 focuses of 9 cases as complex sinus type, which had a false synovial sheath complicated with one to four "second sinus". The pressure sore of sinus type majorly located at the ischial tuberosity. The size of pressure sore ranged from 1.5 cm x 1.0 cm to 3.0 cm X 2.0 cm, and the length of "second sinus" ranged from 8 to 32 cm with an average of 17 cm. After the false synovial sheath was totally excised, the wound was repaired by local sliding or rhombus flaps at the first or second stage in patients with simple sinus type pressure sore. On the basis of excising the false synovial sheath, the "second sinus" was totally removed in the patients with complex sinus type pressure sore. Wound dehiscence occurred in 1 case of simple sinus type pressure sore at 4 days, which was cured after it was sutured again. Wound infection occurred at 9, 17, and 23 days respectively in 3 cases of complex sinus type pressure sore, which was cured after second debridement and necrosis tissues removal. The other wounds healed by first intention, and the flaps totally survived. All patients were followed up 6-12 months (mean, 9.3 months). No recurrence was observed. According to the clinical characteristics, pressure sore of sinus type could be divided into simple sinus type and complex sinus type. The key of successful treatment is to thoroughly excise false synovial sheath and "second sinus".

  11. [Resurfacing of a trochanteric pressure sore by a pedicled fasciocutaneous anterolateral thigh flap: a case report].

    PubMed

    Zeitoun, J; Faghahati, S; Burin Des Roziers, B; Daoud, G; Cartier, S

    2013-06-01

    The anterolateral thigh flap is usually used as a free flap for various kinds of reconstruction and resurfacing of distant areas. Cover of a deep trochanteric pressure sore is commonly made by muscular or musculocutaneous flaps such as tensor of fascia lata or vastus lateralis. We report the case of a trochanteric pressure sore covered by a fasciocutaneous pedicled anterolateral thigh flap after negative pressure therapy in a 58-year-old paraplegic patient. After 6 months, a good quality of coverage was obtained with minimal morbidity of donor site. The pedicled fasciocutaneous anterolateral flap appears as a reliable option for the treatment of trochanteric pressure sore. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

  12. A new flap alternative for trochanteric pressure sore coverage: distal gluteus maximus musculocutaneous advancement flap.

    PubMed

    Nisanci, Mustafa; Sahin, Ismail; Eski, Muhitdin; Alhan, Dogan

    2015-02-01

    Management of long-term bedridden patients experiencing pressure sores still represents a surgical challenge due to limited flap alternatives and high recurrence rates after the treatment. Fasciocutaneous, musculocutaneous, local perforator-based flaps, and free flaps have all been used for treatment of trochanteric pressure sores. This study presents a new use of distal gluteus maximus (GM) muscle as an advancement musculocutaneous flap for coverage of trochanteric pressure sores in 7 patients. The technique involves design of a long V-shaped skin island over the distal fibers of the GM muscle, beginning from the inferoposterior wound edge and extending inferomedially, almost parallel to the gluteal crease. After its harvest as an island flap on the distal fibers of the GM muscle, the skin paddle can be advanced onto the trochanteric defect, whereas the muscle itself is rotated after severing its insertion to femur. If a second triangular skin island is designed on the proximal fibers of GM muscle to cover an associated sacral defect, 2 coexisting pressure sores can be reconstructed concomitantly with 2 skin paddles on a single muscle belly at 1 surgical setting. Of the 7 patients, 3 had 3 (bilateral trochanteric and sacral), 2 had 2 (sacral and trochanteric), and 2 had 1 (only trochanteric) pressure sores. All ulcers were closed successfully and all of the flaps survived totally without any complication except the one in which we experienced minimal wound dehiscence in the early postoperative period. Conclusively, our current surgical method provided a reliable coverage for trochanteric pressure sores although it was technically straightforward and fast. Additionally, it offers simultaneous closure of 2 pressure ulcers with 2 skin islands on a single muscle flap.

  13. [Encircling needling combined with physical factor therapy for severe pressure sore].

    PubMed

    Jia, Chengjie; Su, Bin; Gong, Lili; Wang, Wenying; Zhang, Xiuhua

    2015-11-01

    To compare the clinical efficacy difference between encircling needling combined with physical factor therapy and simple physical factor therapy for severe pressure sore, and to explore the optimal method for severe pressure sores. Thirty-four patients with IV-grade pressure sore were randomly divided into an observation group and a control group, 17 cases in each one. Patients in the control group were treated with conventional nursing, ultrasonic wave and short-wave ultraviolet therapy; additionally, the encircling needling was applied in the observation group. All the treatment was given once a day, 5 times a week, and 4-week treatment constituted one session. Totally, two sessions of treatment were performed. Three indices, including the area of pressure sore, 24-h volume of exudates and wound-bed tissue type, were compared between the two groups before and after treatment; the clinical efficacy was evaluated in the two groups. After treatment of one session and two sessions, the area of pressure sore, 24-h volume of exudates and wound-bed tissue type were significantly reduced in the two groups (P < 0.01, P < 0.05), which was more obvious in the observation group (all P < 0.05). The total effective rate in the observation group was 76.5% (13/17) after 1 session and 94.1% (16/17) after 2 sessions, which were superior to 35.3% (6/17) after 1 session and 64.7% (11/17) after 2 sessions in the control group (both P < 0.05). Encircling needling combined with physical factor therapy can obviously reduce the pressure sore area and 24-h volume of exudates and improve wound-bed tissue type, which is superior to simple physical factor therapy.

  14. Management of Marjolin's ulcer in a chronic pressure sore secondary to paraplegia: a radical surgical solution.

    PubMed

    Fairbairn, Neil G; Hamilton, Stuart A

    2011-10-01

    Marjolin's ulcer refers to malignant degeneration in a chronic wound. Although originally described in an area of burns scar, many other chronic wounds such as osteomyelitis sinus tracts, venous stasis ulcers and chronic pressure sores have the potential to undergo malignant transformation. We present an interesting case of malignant degeneration in a male paraplegic patient with chronic sacral and ischial pressure sores. By discussing our radical surgical solution to this problem, we aim to highlight the importance of prompt diagnosis. © 2011 The Authors. © 2011 Blackwell Publishing Ltd and Medicalhelplines.com Inc.

  15. Pressure sore and skin tear prevention and treatment during a 10-month program.

    PubMed

    Brillhart, Barbara

    2005-01-01

    This article reports the results of a 10-month skin care program for 30 clients on a residential Alzheimer's disease unit. The majority (n = 26) of the clients were free of pressure sores and skin tears through preventive care during this study. Four clients with Stage I pressure sores and/or skin tears were successfully identified by consistent assessment and healed quickly due to rapidly initiated treatments. This skin care program's success was attributed to consistent education, preventive care, assessment, documentation, and treatment executed by the entire care team under the leadership of nurse practitioners, one of whom was certified as a rehabilitation nurse.

  16. Comparison of outcomes of pressure sore reconstructions among perforator flaps, perforator-based rotation fasciocutaneous flaps, and musculocutaneous flaps.

    PubMed

    Kuo, Pao-Jen; Chew, Khong-Yik; Kuo, Yur-Ren; Lin, Pao-Yuan

    2014-10-01

    Pressure sore reconstruction remains a significant challenge for plastic surgeons due to its high postoperative complication and recurrence rates. Free-style perforator flap, fasciocutaeous flap, and musculocutaneous flap are the most common options in pressure sore reconstructions. Our study compared the postoperative complications among these three flaps at Kaohsiung Chang Gung Memorial Hospital. From 2003 to 2012, 99 patients (54 men and 45 women) with grade III or IV pressure sores received regional flap reconstruction, consisting of three cohorts: group A, 35 free-style perforator-based flaps; group B, 37 gluteal rotation fasciocutaneous flaps; and group C, 27 musculocutaneous or muscle combined with fasciocutaneous flap. Wound complications such as wound infection, dehiscence, seroma formation of the donor site, partial or complete flap loss, and recurrence were reviewed. The mean follow-up period for group A was 24.2 months, 20.8 months in group B, and 19.0 months for group C. The overall complication rate was 22.9%, 32.4%, and 22.2% in groups A, B, and C, respectively. The flap necrosis rate was 11.4%, 13.5%, and 0% in groups A, B, and C, respectively. There was no statistical significance regarding complication rate and flap necrosis rate among different groups. In our study, the differences of complication rates and flap necrosis rate between these groups were not statistically significant. Further investigations should be conducted. © 2014 Wiley Periodicals, Inc.

  17. Treatment of Ischial Pressure Sores with Both Profunda Femoris Artery Perforator Flaps and Muscle Flaps

    PubMed Central

    Kim, Chae Min; Yun, In Sik; Lee, Dong Won; Lew, Dae Hyun; Rah, Dong Kyun

    2014-01-01

    Background Reconstruction of ischial pressure sore defects is challenging due to extensive bursas and high recurrence rates. In this study, we simultaneously applied a muscle flap that covered the exposed ischium and large bursa with sufficient muscular volume and a profunda femoris artery perforator fasciocutaneous flap for the management of ischial pressure sores. Methods We retrospectively analyzed data from 14 patients (16 ischial sores) whose ischial defects had been reconstructed using both a profunda femoris artery perforator flap and a muscle flap between January 2006 and February 2014. We compared patient characteristics, operative procedure, and clinical course. Results All flaps survived the entire follow-up period. Seven patients (50%) had a history of surgery at the site of the ischial pressure sore. The mean age of the patients included was 52.8 years (range, 18-85 years). The mean follow-up period was 27.9 months (range, 3-57 months). In two patients, a biceps femoris muscle flap was used, while a gracilis muscle flap was used in the remaining patients. In four cases (25%), wound dehiscence occurred, but healed without further complication after resuturing. Additionally, congestion occurred in one case (6%), but resolved with conservative treatment. Among 16 cases, there was only one (6%) recurrence at 34 months. Conclusions The combination of a profunda femoris artery perforator fasciocutaneous flap and muscle flap for the treatment of ischial pressure sores provided pliability, adequate bulkiness and few long-term complications. Therefore, this may be used as an alternative treatment method for ischial pressure sores. PMID:25075362

  18. Using planned change to implement a pressure sore program.

    PubMed

    Walsh, K C

    1989-08-01

    The establishment of a hospital-wide wound care program is a monumental endeavor requiring mobilization of all available resources. The clinical nurse specialist in a community hospital acted as a change agent to facilitate the formation of a wound care task force, development of wound care protocols and the purchase of wound care products to address the problem of pressure ulcers. With the theory of planned change as a framework, the driving and resisting forces at work are depicted and unanticipated events that speeded and impeded the change process are revealed. Collaboration between nursing and other disciplines is discussed with recommendations offered to other practitioners considering implementation of a wound care program.

  19. [Randomized controlled trial on the effectiveness of Corpitolinol 60 in the prevention of pressure sores in patients undergoing surgery].

    PubMed

    Chiari, Paolo; Giorgi, Sabina; Ugolini, Daniela; Montanari, Morena; Giudanella, Pietro; Gramantieri, Antonella; Collesi, Franca; Pau, Michelina; Smaldone, Maddalena; Matarasso, Maddalena; Mazzini, Cinzia; Russo, Francesca; Gazineo, Domenica; Fontana, Mirella; Taddia, Patrizia

    2012-01-01

    Randomized controlled trial on the effectiveness of Corpitolinol 60 in the prevention of pressure sores in surgical patients. The risk of pressure sores in surgical patients is widely recognised. The Corpitolinol 60 (Sanyréne®) applied on compressed areas seems to reduce the risk of pressure sores. To assess the efficacy of Corpitolinol 60 in preventing pressure sores in the operatory theatre. The open label randomized clinical trial was conducted in 5 operating theatres of Northen Italy. Patients were randomized to receive Corpitolinol 60 in areas undergoing compression. Experimental group and controls were treated with usual measures for preventing pressure sores. The lesions were staged according to NPUAP up to 24 hours after surgery. Three-hundred-one patients were randomized (155 in the Sanyréne® group and 143 controls). The main variables predictive of pressure sores risk (ASA class, sex, age, duration of the surgery, and BMI) were comparable across groups. At the end of the surgery 71 patients (23.8%) in the experimental group and 47 controls (30.8%) had a pressure sore (p 0.006; RR 1.81 IC95% 1.17-2.79). Twelve and 24 hours after surgery the differences between groups were not significant. The aim of reducing pressure sores was not reached for patients treated with Corpitolinol 60.

  20. [Reducing patient pressure sore incidence density in the pediatric surgical intensive care unit].

    PubMed

    Huang, Wei-Chen; Chang, Shiow-Ru; Tang, Chi-Min

    2014-04-01

    Our unit recorded 21 cases of pressure sores from January 2011 to June 2011. The resulting pressure-sore incidence density of 0.74% exceeded the Taiwan Clinical Performance Indicator (TCPI) for medical centers (0.62%) as well as the mean incidence density for our unit (0.55%) during the same period in 2010. We developed this project to decrease the incidence density of pressure sores at our pediatric-surgical-intensive-care unit from 0.74% to 0.31%. Strategies implemented included: 1. providing on-the-job education; 2. providing bedside teaching; 3. developing a series of pictures to illustrate proper sitting, lying, and changing positions and the proper fixation of catheters; 4. implementing a reminder mechanism; 5. introducing pressure-preventing devices; 6. and establishing an audit team. Incidence density decreased from 0.74% (Jan. to Jun. 2011) to 0.18% (Mar. to Jul. 2012). We demonstrated that the developed improvement program effectively reduced the incidence density of pressure sores and increased the quality of nursing care.

  1. An audit of pressure sores caused by intermittent compression devices used to prevent venous thromboembolism.

    PubMed

    Skillman, Joanna; Thomas, Sunil

    2011-12-01

    When intermittent compression devices (ICDs) are used to prevent venous thromboembolism (VTE) they can cause pressure sores in a selected group of women, undergoing long operations. A prospective audit pre and post intervention showed a reduced risk with an alternative device, without increasing the risk of VTE.

  2. Evaluating the effects of pentoxifylline administration on experimental pressure sores in rats by biomechanical examinations

    PubMed Central

    Velaei, Kobra; Torkman, Giti; Rezaie, Fatemealsadat; Amini, Abdollah; Noruzian, Mohsen; Tavassol, Azaedh; Bayat, Mehernoush

    2012-01-01

    This study used a biomechanical test to evaluate the effects of pentoxifylline administration on the wound healing process of an experimental pressure sore induced in rats. Under general anesthesia and sterile conditions, experimental pressure sores generated by no. 25 Halsted mosquito forceps were inflicted on 12 adult male rats. Pentoxifylline was injected intraperitoneally at a dose of 50 mg/kg daily from the day the pressure sore was generated, for a period of 20 days. At the end of 20 days, rats were sacrificed and skin samples extracted. Samples were biomechanically examined by a material testing instrument for maximum stress (N mm2), work up to maximum force (N), and elastic stiffness (N/mm). In the experimental group, maximum stress (2.05±0.15) and work up to maximum force (N/mm) (63.75±4.97) were significantly higher than the control group (1.3±0.27 and 43.3±14.96, P=0.002 and P=0.035, respectively). Pentoxifylline administration significantly accelerated the wound healing process in experimental rats with pressure sores, compared to that of the control group. PMID:23091522

  3. Construct validity of the moisture subscale of the Braden Scale for Predicting Pressure Sore Risk.

    PubMed

    Omolayo, Tolulope; Brown, Kilty; Rapp, Mary Pat; Li, Jing; Barrett, Ryan; Horn, Susan; Bergstrom, Nancy

    2013-03-01

    In this study, the construct validity of the moisture subscale of the Braden Scale for Predicting Pressure Sore Risk is partially supported by the significant inverse relationships between moisture subscale scores, the number of wet observations and soiled observations, brief changes, and differences among the moisture subscale score groups.

  4. In vivo pressure sore-healing efficacy of β-cyclodextrin/polyethyleneimine/silk fibroin xerogel.

    PubMed

    Seo, Seung Ree; Lee, Mi Sun; So, Byung Pil; Kim, Jin-Chul

    2012-08-01

    β-Cyclodextrin (βCD) xerogel containing silk fibroin (SF) was prepared, and the efficacy of the xerogel for a pressure sore developed on the back of an ICR mouse was investigated. Tosyl βCD was conjugated to polyethyleneimine (PEI), and the βCD residues were cross-linked in an aqueous phase using epichlorohydrin as a cross-linker in the presence of SF. The xerogel composed of βCD, PEI, and SF (βCD/PEI/SF xerogel) was prepared by freeze drying the hydrogel. The in vivo pressure sore-healing efficacy of the xerogel was estimated through the skin appearance, skin thickness, hyperplasia of the epidermis, and number of neutrophils in the skin tissue. The animal group treated with βCD/PEI/SF xerogels showed a better sore-healing efficacy than the group without treatment and the group treated with over-the-counter products through the determination of the reduction of hyperplasia of the epidermis and the number of neutrophils in skin tissue. We also got the same result by macroscopic evaluation. βCD/PEI/SF xerogel exhibited a high wound-healing efficacy for pressure sores developed on the back of an ICR mouse and left no scar. © 2012 The International Society of Dermatology.

  5. Multidisciplinary Approach to an Extended Pressure Sore at the Lumbosacral Area

    PubMed Central

    Yoon, Sehoon; Lázaro, Hudson Alex

    2016-01-01

    A pressure sore wound is often extensive or complicated by local infection involving adjacent soft tissue and bone. In this case, a regional flap after simple debridement is not adequate. Here, we present a case of an extensive pressure sore in the sacral area with deep tissue infection. A 43-year-old female patient with a complicated sore with deep tissue infection had a presacral abscess, an iliopsoas abscess, and an epidural abscess in the lumbar spine. After a multidisciplinary approach performed in stages, the infection had subsided and removal of the devitalized tissue was possible. The large soft tissue defect with significant depth was reconstructed with a free latissimus dorsi musculocutaneous flap, which was expected to act as a local barrier from vertical infection and provide tensionless skin coverage upon hip flexion. The extensive sacral sore was treated effectively without complication, and the deep tissue infection completely resolved. There was no evidence of donor site morbidity, and wheelchair ambulation was possible by a month after surgery. PMID:27896193

  6. Multidisciplinary Approach to an Extended Pressure Sore at the Lumbosacral Area.

    PubMed

    Yoon, Sehoon; Jeong, Euicheol; Lázaro, Hudson Alex

    2016-11-01

    A pressure sore wound is often extensive or complicated by local infection involving adjacent soft tissue and bone. In this case, a regional flap after simple debridement is not adequate. Here, we present a case of an extensive pressure sore in the sacral area with deep tissue infection. A 43-year-old female patient with a complicated sore with deep tissue infection had a presacral abscess, an iliopsoas abscess, and an epidural abscess in the lumbar spine. After a multidisciplinary approach performed in stages, the infection had subsided and removal of the devitalized tissue was possible. The large soft tissue defect with significant depth was reconstructed with a free latissimus dorsi musculocutaneous flap, which was expected to act as a local barrier from vertical infection and provide tensionless skin coverage upon hip flexion. The extensive sacral sore was treated effectively without complication, and the deep tissue infection completely resolved. There was no evidence of donor site morbidity, and wheelchair ambulation was possible by a month after surgery.

  7. [High-grade pressure sores in frail older high-risk persons. A retrospective postmortem case-control-study].

    PubMed

    Von Renteln-Kruse, W; Krause, T; Anders, J; Kühl, M; Heinemann, A; Püschel, K

    2004-04-01

    Some old persons at risk do develop, but others, at comparable risk, do not develop high-grade pressure sores. To evaluate potentially different risk factors, we performed a post mortem case-control study in old persons who developed high-grade pressure sores within six months until 14 days before death. Consecutive cases with pressure sores grade >/=3 and potential controls at comparably high risk for pressure sores were examined before cremation. After written informed consent had been obtained by the next relatives, all available nursing and medical records of the deceased were thoroughly evaluated. Cases and controls were matched according to age, gender, immobility, and cachexia.A total of 100 cases with 71 pressure sores grade 3 and 29 pressure sores grade 4 were compared to 100 controls with 27 pressure sores grade pressure sores in frail older high-risk persons. Sedative drug effects and impaired patient compliance with preventive and therapeutic measures may also be associated with the development of high-grade pressure sores in old persons at high risk.

  8. Giant trochanteric pressure sore: Use of a pedicled chimeric perforator flap for cover

    PubMed Central

    Mehrotra, Sandeep

    2009-01-01

    Pressure sores are increasing in frequency commensurate with an ageing population with multi-system disorders and trauma. Numerous classic options are described for providing stable wound cover. With the burgeoning knowledge on perforator anatomy, recent approaches focus on the use of perforator-based flaps in bedsore surgery. A giant neglected trochanteric pressure sore in a paraplegic is presented. Since conventional options of reconstruction appeared remote, the massive ulcer was successfully managed by a chimeric perforator-based flap. The combined muscle and fasciocutaneous flaps were raised as separate paddles based on the anterolateral thigh perforator branches and provided stable cover without complications. Perforators allow versatility in managing complex wounds without compromising on established principles. PMID:19881035

  9. The safety and effect of topically applied recombinant basic fibroblast growth factor on the healing of chronic pressure sores.

    PubMed Central

    Robson, M C; Phillips, L G; Lawrence, W T; Bishop, J B; Youngerman, J S; Hayward, P G; Broemeling, L D; Heggers, J P

    1992-01-01

    The first randomized, blinded, placebo-controlled human trials of recombinant basic fibroblast growth factor (bFGF) for pressure sore treatment were performed. Three different concentrations of bFGF in five dosing schedules were tested for safety using hematology, serum chemistries, urinalysis, absorption, antibody formation, and signs of toxicity. Efficacy was evaluated by wound volumes, histology, and photography. No toxicity, significant serum absorption, or antibody formation occurred. In six of eight subgroups, there was a trend toward efficacy with bFGF treatment. When all subgroups were combined, comparison of the slopes of the regression curves of volume decrease over initial pressure sore volume demonstrated a greater healing effect for the bFGF-treated patients (p < 0.05). Histologically, bFGF-treated wound sections demonstrated increased fibroblasts and capillaries. More patients treated with bFGF achieved > 70% wound closure (p < 0.05). Blinded observers were able to distinguish differences in visual wound improvement between bFGF and placebo groups. These data suggest that bFGF may be effective in the treatment of chronic wounds. PMID:1417189

  10. The effect of endotracheal tube cuff pressure change during gynecological laparoscopic surgery on postoperative sore throat: a control study.

    PubMed

    Geng, Guiqi; Hu, Jingyi; Huang, Shaoqiang

    2015-02-01

    Postoperative respiratory complications related to endotracheal intubation usually present as cough, sore throat, hoarseness. The aim of the study was to examine the effects of endotracheal tube cuff pressure changes during gynecological laparoscopic surgery on postoperative sore throat rates. Thirty patients who underwent gynecological laparoscopic surgery and 30 patients who underwent laparotomy under general anesthesia with endotracheal intubation were included. After induction of general anesthesia and endotracheal intubation, the cuff was inflated to 25 mmHg. At 5, 15, 30, 45 and 60 min after endotracheal intubation, cuff pressure and peak airway pressure were recorded. At 2 and 24 h after surgery, the patients were assessed for complaints of a sore throat. In patients who underwent laparotomy, cuff pressure and peak airway pressure did not change significantly at different time points after intubation. In patients who received laparoscopic surgery, cuff pressure and peak airway pressure were significantly increased compared to initial pressure at all examined time points. In both groups, the endotracheal tube cuff pressure and peak airway pressure were significantly correlated (R=0.9431, P<0.01; R=0.8468, P<0.01). Compared to patients who had undergone laparotomy, patients who had undergone laparoscopic surgery showed significantly higher sore throat scores at both 2 and 24 h after surgery (P<0.01). Pneumoperitoneum and Trendelenburg position may increase airway pressure and cuff pressure, resulting in increased incidence of postoperative sore throat.

  11. Cushions and specialist chairs for pressure sore management.

    PubMed

    Cooper, P

    Many patients spend more time sitting out of bed than being cared for in bed. Consequently, the demand for specialist support surfaces for chairs to reduce the risk of pressure damage while the patient is up sitting is rising. This product focus examines a number of seating support surfaces produced by Karomed.

  12. Design and research on reliability-validity for 3S intraoperative risk assessment scale of pressure sore.

    PubMed

    Gao, Xing-lian; Hu, Juan-juan; Ma, Qiong; Wu, He-yu; Wang, Zeng-yan; Li, Ting-ting; Shen, Jian-hui; Yang, Ying

    2015-04-01

    The reliability and validity of risk assessment scale (RAS) of pressure sore during 3S surgery were investigated. RAS of pressure sore was designed independently during 3S surgery. Five operating room nursing experts were selected to consult and detect face validity. Convenient and purposive sampling of 707 samples was conducted. Cronbach's alpha was used to measure content reliability and evaluate the internal consistence of RAS. The structural reliability was investigated by exploratory factor analysis method. The results showed that the content validity index was 0.92, and Cronbach's alpha of content reliability was 0.71. Structural validity, detected by Bartlett sphericity test, was 135.3 for 707 samples with the difference being statistically significant (P<0.01). KMO value was 0.729. The accumulative variance contribution ratio of common factor was 64.63%. The exploratory factor analysis showed the factor load of every clause was larger than 0.596. It was concluded that RAS of pressure sore for 3S surgery has better validity and reliability, and it could be used for evaluating and screening the high risk patients with pressure sores during surgery in order to efficiently reduce the occurrence of pressure sore during surgery. RAS of pressure sore for 3S surgery is worth to be popularized.

  13. Computer-based testing of the Braden Scale for Predicting Pressure Sore Risk.

    PubMed

    Maklebust, JoAnn; Sieggreen, Mary Y; Sidor, Deborah; Gerlach, Mary A; Bauer, Carole; Anderson, Carol

    2005-04-01

    The Detroit Medical Center nursing documentation system requires all staff nurses to complete the Braden Scale for Predicting Pressure Sore Risk on an Acute Care Flow Record or Critical Care Flow Sheet on every patient, every day. An audit of these records raised concern as to whether staff nurses accurately used the Braden Scale to calculate pressure sore risk. Advanced Practice and ET Nurses noted that staff nurses were rating patients at lower levels of pressure sore risk than was warranted by the patient condition. In response, a computer-based learning module with case study examples was developed and tested to teach nursing staff to accurately evaluate pressure ulcer risk by using the Braden Scale and its subscales and to identify preventive interventions based on the patient's Braden subscale scores. Following revisions of those case study example narratives that were found to be problematic, the learning/assessment module was instituted in 2002. More than 2,500 nurses at the facility were tested regarding their knowledge of pressure ulcer risk assessment and prevention using this program. On average, nurses correctly rated the Braden Scale level of risk 75.6% of the time. The percentage of correct responses was highest for very high (92%) and very low (78%) levels of risk. This finding is consistent with the observation that most nosocomial pressure ulcers in this facility occur in patients who are rated in the "mild risk" level on the Braden scale. Subscales with the lowest percentage of correct answers were moisture and sensory perception. Correct clinical identification of a Stage I pressure ulcer as it was described in writing occurred only 53% of the time. These results indicate that training and practice are needed to use an assessment scale accurately. The Detroit Medical Center plans to include the Braden Scale in annual nursing education and competency testing.

  14. The contribution made by an armchair with integral pressure-reducing cushion in the prevention of pressure sore incidence in the elderly, acutely ill patient.

    PubMed

    Collins, F

    1999-10-01

    The paper describes a clinical controlled trial of an armchair with integral pressure-reducing cushion, which took place on two elderly acute medical wards in a district general hospital. The aim of the study was to evaluate whether the armchair would have an impact on reducing the occurrence of pressure sores. All patients were provided with a mattress or overlay in accordance with the hospital policy on mattress provision following a Waterlow risk assessment. Patients on ward A were provided with an armchair with integral pressure-reducing cushion, whilst patients on ward B continued to use their existing bedside armchair. Nominal data were collected on all pressure sores in patients who were not bedridden. Ward A had a significantly lower incidence of hospital-acquired pressure sores compared to ward B, and non-hospital-acquired pressure sores on this ward showed more improvement than those on ward B.

  15. The effect of cuff pressure on postoperative sore throat after Cobra perilaryngeal airway.

    PubMed

    Joe, Han Bum; Kim, Dae Hee; Chae, Yun Jeong; Kim, Jong Yeop; Kang, Min; Park, Kwan Sik

    2012-04-01

    The cuff volume of the Cobra perilaryngeal airway (CobraPLA) is larger than that of other alternative airway devices and makes it difficult to predict the effect of cuff pressure on the perilaryngeal mucosa. We tested the hypothesis that adjustment of the cuff pressure of the CobraPLA could reduce the incidence of postoperative sore throat (POST). After induction of general anesthesia and insertion of the CobraPLA by standardized method, the cuff pressure was set to 60 cmH(2)O (group C, n = 87) or adjusted to minimal seal-up pressure +5 cmH(2)O (group A, n = 87). The frequency and severity (0, none; 1, mild; 2, moderate; 3, severe) of throat soreness, pain, discomfort, and adverse effects were evaluated 1 and 24 h after removal of the CobraPLA. Incidence of moderate POST in group C was higher than that in group A (11% vs. 2%, P = 0.021) whereas the overall POST incidence was not different between the two groups (31% vs. 20%, P = 0.092). The inflated air volume of group A was different from that of group C (41 vs. 50 ml, P = 0.009). Adjustment of cuff pressure reduces the incidence of moderate POST after use of the CobraPLA.

  16. Dual-dermal-barrier fashion flaps for the treatment of sacral pressure sores.

    PubMed

    Hsiao, Yen-Chang; Chuang, Shiow-Shuh

    2015-02-01

    The sacral region is one of the most vulnerable sites for the development of pressure sores. Even when surgical reconstruction is performed, there is a high chance of recurrence. Therefore, the concept of dual-dermal-barrier fashion flaps for sacral pressure sore reconstruction was proposed. From September 2007 to June 2010, nine patients with grade IV sacral pressures were enrolled. Four patients received bilateral myocutaneous V-Y flaps, four patients received bilateral fasciocutaneous V-Y flaps, and one patient received bilateral rotation-advanced flaps for sacral pressure reconstruction. The flaps were designed based on the perforators of the superior gluteal artery in one patient's reconstructive procedure. All flaps' designs were based on dual-dermal-barrier fashion. The mean follow-up time was 16 months (range = 12-25). No recurrence was noted. Only one patient had a complication of mild dehiscence at the middle suture line, occurring 2 weeks after the reconstructive surgery. The dual-dermal fashion flaps are easily duplicated and versatile. The study has shown minimal morbidity and a reasonable outcome.

  17. Application of skin traction for surgical treatment of grade IV pressure sore: a clinical report of 160 cases.

    PubMed

    Chen, X; Jiang, Z; Chen, Z; Wang, D

    2011-01-01

    Retrospective clinical study. To assess the method of primary surgical closure of pressure sores developed by the Ruixin Hospital for burns. Nanjing, China. The study included 235 grade IV pressure sores of 160 patients, M:F = 119:41. Their age ranged from 19 to 93 years (mean = 47.4, s.d. ± 15.7). The primary disease was spinal cord injury in 141 patients (88.1%). The location of sore spread over ischial, sacrococcygeal and trochanteric regions. The largest pressure sore measured 15 × 25 cm(2). The time from onset of sore to admission ranged from 3 months to 22 years (mean = 35.5 months, s.d. ± 55.8). Local preoperative preparation included external skin traction using adhesive tapes, wound cleaning and change of dressing. General condition was checked and improved by supportive measures. Operation procedures included thorough debridement, excision of hidden minor scars, mobilizing opposing skin flaps and meticulous haemostasis before closure. Skin traction continued after the operation until the wound was healed. All but 10 sores healed primarily. These 10 sores healed after a revision. The length of stay in hospital ranged from 20 to 140 days (mean = 45.1 days, s.d. ± 21.1). Follow-up period was 2-51 months (mean = 22 months, s.d. ± 12.5). Two ischial sores recurred owing to long sitting. They were cured with the same method. Three illustrative cases are presented. The method is simple and enjoys a high success rate with a short stay in hospital and hence is cost effective. The recurrence is rare.

  18. Pressure sore prevention pads as an infective source in orthopaedic theatres.

    PubMed

    Ranawat, V S; Dowell, J K; Teare, E L

    2004-04-01

    Current theatre practice and protocol involves the use of pressure sore prevention pads in the positioning and support of all patients undergoing orthopaedic surgery. Microbiological swabs were taken from those pads placed adjacent to the operative field immediately before implant surgery. Eleven out of the 13 pads sampled yielded bacterial growth capable of causing deep-seated infection. The transfer of these pads between the designated orthopaedic theatres and the rest of the theatre complex was also noted. We recommend that the use of these pads should be closely reviewed. They should either be used with stricter guidelines for decontamination between use or disposable 'clean' alternatives sought.

  19. [Gluteal artery based perforator flaps for sacral pressure sore reconstruction in children].

    PubMed

    Berenguer, B; Simal, I; Marín, M C; E de Tomás; Riquelme, O; García Martín, A; González, J L

    2014-10-01

    Children have much lower incidence of pressure sores (PS) than adults and furthermore, they are diagnosed in earlier stages. Therefore, the reported experience with surgical treatment of advanced pediatric PS is scarce. We present the surgical treatment of 2 chronic PS stage IV in children aged 11 and 14 years, by means of perforator flaps based on the gluteal arteries: in the first case we used a free-style flap based on a left medial gluteal perforator and in the second a large reusable rotation-advancement flap based on both right superior and inferior gluteal artery perforators. In both patients we achieved a rapid cure with 100% survival of the flaps and a stable cover over a 6 month and 1 year follow-up respectively. Gluteal artery perforator flaps can produce excellent and durable results in the reconstructive treatment of sacral pressure sores in children. These flaps carry lower morbidity than musculocutaneous flaps and are more reliable than traditional fasciocutaneous flaps. Furthermore they preserve more reconstructive options in case of recurrence during the children's lifetime.

  20. At-Home Application of Autologous Platelet Rich Plasma as Treatment for Pressure Sore and Related Anemia.

    PubMed

    Tendas, Andrea; Niscola, Pasquale; Giovannini, Marco; Costa, Adriana; Venditti, Daniela; Volta, Laura; Malandruccolo, Luigi; Sabbadini, Stefania; Lasorella, Rosa; Fabritiis, Paolo de; Cassetta, Rita; Perrotti, Alessio P

    2017-01-01

    Pressure sores are a major complication in the bed-ridden older patient. In this report, we present the case of platelet rich plasma (PRP) application for the treatment of a pressure sore in an 88-year-old female affected by transfusion-dependent chronic inflammatory disease anemia associated with the congenital and inherited condition of thalassemic trait carrier. A weekly application schedule was planned athome, given the patient's debilitation and her decreased performance status as well as personal and family difficulties to go as outpatients at our treatment center. After 9 PRP applications, a remarkable sore improvement was achieved so that PRP was discontinued; nevertheless, sore rapidly improved until the full resolution and the complete closing after 4 months from the start of PRP treatment. Noteworthy, transfusion support was interrupted and a significant recovery and a sustained stabilization of hemoglobin (Hb) level at 1 year after ulcer healing were observed. The present case suggests that PRP application, performed athome in our case, is a feasible and effective treatment for pressure sores and related complications. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  1. Pressure-time cell death threshold for albino rat skeletal muscles as related to pressure sore biomechanics.

    PubMed

    Linder-Ganz, Eran; Engelberg, Santiego; Scheinowitz, Mickey; Gefen, Amit

    2006-01-01

    Deep pressure sores (DPS) are associated with inadequate soft tissue perfusion and excessive tissue deformation over critical time durations, as well as with ischemia-reperfusion cycles and deficiency of the lymphatic system. Muscle tissue shows the lowest tolerance to pressure injuries, compared with more superficial tissues. In this communication, we present new histopathology data for muscle tissue of albino (Sprague-Dawley) rats exposed to pressures for 15 or 30 min. These data are superimposed with an extensive literature review of all previous histopathology reported for albino rat skeletal muscles subjected to pressure. The pooled data enabled a new mathematical characterization of the pressure-time threshold for cell death in striated muscle of rats, in the form of a sigmoid pressure-time relation, which extends the previous pressure-time relation to the shorter exposure periods. We found that for pressure exposures shorter than 1 h, the magnitude of pressure is the important factor for causing cell death and the exposure time has little or no effect: even relatively short exposures (15 min - 1 h) to pressures greater than 32 kPa (240 mmHg) cause cell death in rat muscle tissue. For exposures of 2 h or over, again the magnitude of pressure is the important factor for causing cell death: pressures greater than 9 kPa (67 mmHg) applied for over 2 h consistently cause muscle cell death. For the intermediate exposures (between 1 and 2 h), the magnitude of cell-death-causing pressure strongly depends on the time of exposure, i.e., critical pressure levels drop from 32 to 9 kPa. The present sigmoidal pressure-time cell death threshold is useful for design of studies in albino rat models of DPS, and may also be helpful in numerical simulations of DPS development, where there is often a need to extrapolate from tissue pressures to biological damage.

  2. Relationship between saddle pressure measurements and clinical signs of saddle soreness at the withers.

    PubMed

    von Peinen, K; Wiestner, T; von Rechenberg, B; Weishaupt, M A

    2010-11-01

    Similar to human decubitus ulcers, local high pressure points from ill-fitting saddles induce perfusion disturbances of different degrees resulting in tissue hypoxia and alteration in sweat production. To relate the different clinical manifestations of saddle sores to the magnitude of saddle pressures at the location of the withers. Sixteen horses with dry spots after exercise (Group A) and 7 cases presented with acute clinical signs of saddle pressure in the withers area (Group B) were compared with a control group of 16 sound horses with well fitting saddles (Group C). All horses underwent a saddle pressure measurement at walk, trot and canter. Mean and maximal pressures in the area of interest were compared between groups within each gait. Mean pressures differed significantly between groups in all 3 gaits. Maximal pressure differed between groups at trot; at walk and canter, however, the only significant difference was between Group C and Groups A and B, respectively, (P > 0.05). Mean and maximal pressures at walk in Group A were 15.3 and 30.6 kPa, in Group B 24.0 and 38.9 kPa and in Group C 7.8 and 13.4 kPa, respectively; at trot in Group A 18.1 and 43.4 kPa, in Group B 29.7 and 53.3 kPa and in Group C 9.8 and 21.0 kPa, respectively; and at canter in Group A 21.4 and 48.9 kPa, in Group B 28.6 and 56.0 kPa and in Group C 10.9 and 24.7 kPa, respectively. The study shows that there is a distinguishable difference between the 3 groups regarding the mean pressure value, in all gaits. © 2010 EVJ Ltd.

  3. [Improving seating comfort in wheelchairs for the prevention of pressure sores].

    PubMed

    Diebschlag, W; Hörmann, M

    1987-11-01

    The risk factors for occurrence of pressure sores--pressure, temperature and humidity--were measured in extensive tests on commercially available wheelchair designs. The effects of different chair positions on the strain and pressure distribution on the backrest, seat surface and foot rests were recorded on a universally adjustable experimental chair. In order to appraise the influence of various types of handicaps, the experiments were conducted with paraplegic, spastic and hemiplegic subjects. It became evident from the results obtained that the currently used suspension belt chairs display serious deficiencies, inherent in their construction principle. Above all, they do not offer an adequately large support area to handicapped persons with severe atrophy of the gluteal muscle. Also, a backrest shape with lumbar pad, as requested by physiologists and orthopaedic surgeons, is technically difficult to realize. Considerable improvements with respect to pressure distribution and orthopaedically correct support of the seated patient can be achieved by using a shell seat construction. In order to enable the handicapped person to use various sitting postures, the backrest should be provided with a rotary joint to the sitting surface.

  4. Quantitative assessment of pressure sore generation and healing through numerical analysis of high-frequency ultrasound images.

    PubMed

    Moghimi, Sahar; Miran Baygi, Mohammad Hossein; Torkaman, Giti; Mahloojifar, Ali

    2010-01-01

    Abstract-This article focuses on the development of a method to quantitatively assess the healing process of artificially induced pressure sores using high-frequency (20 MHz) ultrasound images. We induced sores in guinea pigs and monitored predefined regions on days 3, 7, 14, and 21 after sore generation. We extracted relevant parameters regarding the tissue echographic structure and attenuation properties. We examined tissue healing by defining a healing function that used the extracted parameters. We verified the significance of the extracted features by using analysis of variance and multiple comparison tests. The features displayed ascending/descending behavior during wound generation and reverse behavior during healing. We optimized the parameters of our healing function by using a pattern search method. We tested the efficiency of the optimized values by calculating the healing function value on assessment days and then comparing these results with the expected pattern of changes in the tissue conditions after removing the applied pressure. The results of this study suggest that the methodology developed may be a viable tool for quantitative assessment of pressure sores during their early generation as well as during healing stages.

  5. Post-exercise muscle soreness after eccentric exercise: psychophysical effects and implications on mean arterial pressure.

    PubMed

    Bajaj, P; Graven-Nielsen, T; Arendt-Nielsen, L

    2001-10-01

    The aim of the study was to examine the time course of changes in pressure pain threshold (PPT), visual analogue scale (VAS) pain and tenderness scores, McGill Pain Questionnaire (MPQ) descriptors, pain areas, skin temperature and mean arterial pressure (MAP) following intensive eccentric exercise. In 11 healthy male subjects, eccentric exercise of the first dorsal interosseous muscle (FDI) of the right hand with 114% maximum voluntary contraction weight (MVC) was used to induce post-exercise muscle soreness (PEMS) in the right hand, while the left hand served as a control. At 24 h to 48 h all the pain profiles indicated the presence of PEMS in the right hand when compared to before exercise (P<0.05). MPQ and pain area assessments also indicated PEMS immediately after the exercise, while the pain assessment by PPT and tenderness VAS showed insignificant pain immediately after the exercise. Skin temperature measured in the first web space of the hand did not change at any time. MAP was significantly reduced at 48 h. It is concluded that eccentric exercise of a small hand muscle is followed by PEMS and a reduced MAP after 48 h that may suggest a role of central mechanisms in the PEMS, thereby giving further insight into clinical aspects of muscle pain.

  6. [Postoperative sore throat and intracuff pressure: comparison among endotracheal intubation, laryngeal mask airway and cuffed oropharyngeal airway].

    PubMed

    Saeki, H; Morimoto, Y; Yamashita, A; Nagusa, Y; Shimizu, K; Oka, H; Miyauchi, Y

    1999-12-01

    We studied which device is most useful to reduce postoperative sore-throat. We investigated the relationship between intracuff pressure and postoperative sore-throat in using endotracheal intubation (ET), the laryngeal mask airway (LMA) and the cuffed oropharyngeal airway (COPA) in adult patients. We classified sore-throat into categories; pain at rest, hoarseness and dysphasia. We evaluated pain at rest by the score (0: no pain, 1: mild discomfort, 2: mild pain, 3: severe pain). Pain at rest (scores 1, 2, 3) was complained by 10 patients in ET group, 3 in LMA group, 5 in COPA group on the day of operation, showing significantly lower incidence of pain at rest in LMA group than in ET group. Hoarseness was complained by 15 patients in ET group, 2 in LMA group and 4 in COPA group, showing significantly lower incidence of hoarseness in LMA and COPA groups than in ET group. Dysphasia was complained by 3 in ET group, 1 in LMA group and 2 in COPA group, showing no significant difference. These results suggest that LMA is most appropriate to reduce postoperative sore-throat.

  7. The Norton, Waterlow, Braden, and Care Dependency Scales: comparing their validity when identifying patients' pressure sore risk.

    PubMed

    Balzer, Katrin; Pohl, Claudia; Dassen, Theo; Halfens, Rudd

    2007-01-01

    We compared the sensitivity and specificity of the Norton, Waterlow, and Braden Scales in identifying patients at pressure sore risk. An additional goal was to determine whether or not the Care Dependency Scale (CDS) is able to detect patients at risk for pressure sore development. The investigation was part of a prevalence study involving 754 patients in 3 Berlin hospitals. A questionnaire was used containing the subscales of the 3 risk calculators (Norton, Waterlow, and Braden), and the CDS. On the specified day nurses filled in the questionnaire using data obtained from the patients' charts and direct visualization of the patients' skin. Thirty-four out of 754 patients had at least 1 pressure ulcer. Comparing the 3 risk assessment tools, the Waterlow scale demonstrated the highest sensitivity (0.86) and the Norton scale demonstrated the highest specificity (0.75). Individuals with pressure sores were more likely to be care dependent (t-test: P< .01); 27 of them had a CDS score lower than 55. Using the score of 55 as the cut-off point, the CDS demonstrated a sensitivity of 0.74 and a specificity of 0.83. This study demonstrated remarkable differences among the 3 commonly used risk assessment tools, in regards to sensitivity and specificity. Moreover, the CDS seems to have a diagnostic value similar to the 3 commonly used risk assessment calculators.

  8. Intraoperative indocyanine green fluorescent angiography-assisted modified superior gluteal artery perforator flap for reconstruction of sacral pressure sores.

    PubMed

    Chang, Chun-Kai; Wu, Chien-Ju; Chen, Chun-Yu; Wang, Chi-Yu; Chu, Tzi-Shiang; Hsu, Kuo-Feng; Chiu, Han-Ting; Liu, Hung-Hui; Chou, Chang-Yi; Wang, Chih-Hsin; Lin, Chin-Ta; Dai, Niann-Tzyy; Tzeng, Yuan-Sheng

    2017-07-23

    Pressure sores are often observed in patients who are bedridden. They can be a severe problem not only for patients and their caregivers but also for plastic surgeons. Here, we describe a new method of superior gluteal artery perforator flap harvesting and anchoring with the assistance of intraoperative indocyanine green fluorescent angiography. In this report, we describe the procedure and outcomes for 19 patients with grades III and IV sacral pressure sores who underwent the operation between September 2015 and November 2016. All flaps survived, and two experienced wound-edge partial dehiscence. With the assistance of this imaging device, we were able to acquire a reliable superior gluteal artery perforator flap and perform modified operations with it that are safe, easy to learn and associated with fewer complications than are traditional. © 2017 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

  9. Design of a Novel Two-Component Hybrid Dermal Scaffold for the Treatment of Pressure Sores.

    PubMed

    Sharma, Vaibhav; Kohli, Nupur; Moulding, Dale; Afolabi, Halimat; Hook, Lilian; Mason, Chris; García-Gareta, Elena

    2017-09-12

    The aim of this study is to design a novel two-component hybrid scaffold using the fibrin/alginate porous hydrogel Smart Matrix combined to a backing layer of plasma polymerized polydimethylsiloxane (Sil) membrane to make the fibrin-based dermal scaffold more robust for the treatment of the clinically challenging pressure sores. A design criteria are established, according to which the Sil membranes are punched to avoid collection of fluid underneath. Manual peel test shows that native silicone does not attach to the fibrin/alginate component while the plasma polymerized silicone membranes are firmly bound to fibrin/alginate. Structural characterization shows that the fibrin/alginate matrix is intact after the addition of the Sil membrane. By adding a Sil membrane to the original fibrin/alginate scaffold, the resulting two-component scaffolds have a significantly higher shear or storage modulus G'. In vitro cell studies show that dermal fibroblasts remain viable, proliferate, and infiltrate the two-component hybrid scaffolds during the culture period. These results show that the design of a novel two-component hybrid dermal scaffold is successful according to the proposed design criteria. To the best of the authors' knowledge, this is the first study that reports the combination of a fibrin-based scaffold with a plasma-polymerized silicone membrane. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Validation of the mobility subscale of the Braden Scale for predicting pressure sore risk.

    PubMed

    Powers, Geralyn C; Zentner, Tana; Nelson, Francine; Bergstrom, Nancy

    2004-01-01

    The Braden Scale for Predicting Pressure Sore Risk has been tested extensively for reliability and validity, but the validity of each subscale has not been evaluated. Because subscale scores are intended to guide patient care decisions, validity is an important issue. : To establish the convergent construct validity of the mobility subscale of the Braden Scale. The study evaluated 16 members at a veterans' home (4 members representing each score on the mobility subscale). Movement, as recorded by a Motionlogger Actigraph, a wristwatch-sized accelerometer and microprocessor that measures physical movement (activity), was measured continuously. Each person wore an Actigraph on the nondominant ankle for 72 hours. The mean activity for each of the four subscale score groups was plotted, producing a histogram in which higher scores were associated with greater activity (F[3, 15] = 31.69;p <.001, one-way analysis of variance), as expected. Pair wise multiple comparisons between groups showed that only the subgroup with a score of 4 was significantly different in mean activity (p <.001) from the other three score groups. Convergent construct validity for the Braden mobility subscale was supported. A larger sample and establishment of a threshold to eliminate minor, ineffective movements from Motionlogger Actigraph measures may distinguish between significant and nonsignificant movement.

  11. [Efficacy of photodynamic antimicrobial therapy for wound flora and wound healing of pressure sore with pathogen infection].

    PubMed

    Wang, Chaoliang; Huang, Sufang; Zhu, Tao; Sun, Xuesheng; Zou, Yong; Wang, Yingzhen

    2014-08-19

    To explore the efficacy of photodynamic antimicrobial therapy in the treatment of pressure sore with pathogen infection. A total of 42 pressure sore patients with pathogen infection were divided randomly into experimental and control groups (n = 21 each). Fufanghuangbai liquid was used for external application with control group. In the experimental group, wound was treated with Fufanghuangbai liquid wet dressing and irradiated by semiconductor laser 30 min late. The distance from semiconductor laser probe to wound site was 10-15 cm, 20 min twice daily, continuous exposure to 7 days for 1 course. The results of bacterial culture and epidermal growth factor (EGF) expression of wound granulation tissue were observed before and after treatment. And the changes of healing rate of pressure sore were measured at post-treatment in each group. The positive rates of bacterial culture, rates of change around wound inflammation, healing rate of days 7 and 14, the high expression of EGF on healing wound granulation tissue was 9.75%, (32.2% ± 5.8%), (89.1% ± 5.6%), (12.4% ± 2.9%), (34.7% ± 3.6%), 14/21 in the treatment group versus 51.2%, (17.8% ± 2.0%), (57.3% ± 2.6%), (5.1% ± 1.1%), (10.5% ± 2.4%), 2/21 in the control group respectively. The inter-group differences were statistically significant (P < 0.05). Photodynamic antimicrobial therapy is an effective method for pressure sore with pathogen infection. Wound healing is promoted through an up-regulation of EGF.

  12. Automatic evaluation of pressure sore status by combining information obtained from high-frequency ultrasound and digital photography.

    PubMed

    Moghimi, Sahar; Baygi, Mohammad Hossein Miran; Torkaman, Giti

    2011-07-01

    In this study, the different phases of pressure sore generation and healing are investigated through a combined analysis of high-frequency ultrasound (20 MHz) images and digital color photographs. Pressure sores were artificially induced in guinea pigs, and the injured regions were monitored for 21 days (data were obtained on days 3, 7, 14, and 21). Several statistical features of the images were extracted, relating to both the altering pattern of tissue and its superficial appearance. The features were grouped into five independent categories, and each category was used to train a neural network whose outputs were the four days. The outputs of the five classifiers were then fused using a fuzzy integral to provide the final decision. We demonstrate that the suggested method provides a better decision regarding tissue status than using either imaging technique separately. This new approach may be a viable tool for detecting the phases of pressure sore generation and healing in clinical settings. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

  13. [Thigh and leg musculo-cutaneous island flap for giant bilateral trochanteric and perineal pressure sores coverage: Extreme treatment in spinal cord injury].

    PubMed

    André, A; Crouzet, C; De Boissezon, X; Grolleau, J-L

    2015-06-01

    Surgical treatment of perineal pressure sores could be done with various fascio-cutaneous or musculo-cutaneous flaps, which provide cover and filling of most of pressure sores after spinal cord injuries. In rare cases, classical solutions are overtaken, then it is necessary to use more complex techniques. We report a case of a made-to-measure lower limb flap for coverage of confluent perineal pressure sores. A 49-year-old paraplegic patient developed multiple pressure sores on left and right ischial tuberosity, inferior pubic bone and bilateral trochanters with hips dislocation. Surgical treatment involved a whole right thigh flap to cover and fill right side lesions, associated to a posterior right leg musculo-cutaneous island flap to cover and fill the left trochanteric pressure sore. The surgical procedure lasted 6.5 hours and required massive blood transfusion. Antibiotics were adapted to bacteriological samples. There were no postoperative complications; complete wound healing occurred after three weeks. A lower limb sacrifice for coverage of a giant perineal pressure sores is an extreme surgical solution, reserved to patients understanding the issues of this last chance procedure. A good knowledge of vascular anatomy is an essential prerequisite, and allows to shape made-to-measure flaps. The success of such a procedure is closely linked to the collaboration with the rehabilitation team (appropriate therapeutic education concerning transfers and positioning). Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  14. Cold Sore

    MedlinePlus

    ... genitals. Most people who are infected with the virus that causes cold sores never develop signs and symptoms. Cold sores ... an infection — test positive for evidence of the virus that causes cold sores. People who have weakened immune systems are ...

  15. Mouth sores

    MedlinePlus

    ... like acetaminophen. For canker sores: Apply a thin paste of baking soda and water to the sore. Mix 1 part hydrogen peroxide with 1 part water and apply this mixture to the sores using a ... (Aphthasol), or chlorhexidine gluconate (Peridex) mouthwash. Over-the- ...

  16. Adipose Tissue Drives Response to Ischemia-Reperfusion Injury in a Murine Pressure Sore Model.

    PubMed

    Gust, Madeleine J; Hong, Seok Jong; Fang, Robert C; Lanier, Steven T; Buck, Donald W; Nuñez, Jennifer M; Jia, Shengxian; Park, Eugene D; Galiano, Robert D; Mustoe, Thomas A

    2017-05-01

    Ischemia-reperfusion injury contributes significantly to the pathogenesis of chronic wounds such as pressure sores and diabetic foot ulcers. The authors' laboratory has previously developed a cyclical murine ischemia-reperfusion injury model. The authors here use this model to determine factors underlying tissue response to ischemia-reperfusion injury. C57BL/6 mice were subjected to cycles of ischemia-reperfusion that varied in number (one to four cycles) and duration of ischemia (1 to 2 hours). For each ischemia-reperfusion condition, the following variables were analyzed: (1) digital photographs for area of necrosis; (2) hematoxylin and eosin staining and immunohistochemistry for inflammatory infiltrate; and (3) expression of inflammatory markers by quantitative polymerase chain reaction. In addition, human adipocytes and fibroblasts were cultured in vitro under conditions of hypoxia and reoxygenation, and expression of inflammatory markers was analyzed by quantitative polymerase chain reaction. Increases in both ischemia-reperfusion cycle number and ischemia duration correlated with increased areas of epithelial necrosis both grossly and histologically, and with an increase in cellularity and neutrophil density. This increased inflammatory infiltrate and a significant increase in the expression of proinflammatory markers (Hmox1, interleukin-6, interleukin-1, and monocyte chemoattractant protein-1) was observed in adipose tissue subjected to ischemia-reperfusion injury, but not in dermis. These results were mirrored in human adipose tissue. The authors further characterize a novel, reproducible murine model of ischemia-reperfusion injury. The results of their study indicate that adipose tissue is less tolerant of ischemia-reperfusion than dermal tissue. Rather than being an "innocent bystander," adipose tissue plays an active role in driving the inflammatory response to ischemia-reperfusion injury.

  17. [Changes in intracuff pressure of endotracheal tubes permeable or resistant to nitrous oxide and incidence of postoperative sore throat].

    PubMed

    Sato, Koji; Tanaka, Makoto; Nishikawa, Toshiaki

    2004-07-01

    We assessed the nitrous oxide (N2O) gas-barrier properties of a new endotracheal tube cuff, the Profile Soft-Seal Cuff (Resistant: R) (Sims Portex, Kent, UK). The tracheas of randomly selected patients were intubated with the Profile Cuff (Permeable: P) (Sims Portex) tuble or with Portex Soft-Seal Cuff (R) (n=20 each) endotracheal tube. Cuffs were inflated with air, and intracuff pressure was measured during anesthesia using 67% N2O. Postoperative sore throat was assessed. In addition, the volume-pressure relationship of the cuff was determined in vitro. Cuff pressure increased gradually during anesthesia in both groups. The mean cuff pressure of the group R was significantly lower than that of the group P from 10 minutes to 230 minutes. The inflated gas and the deflated gas were not significantly different in both groups. The incidence of postoperative sore throat was not significantly different between the two groups. In vitro, the mean cuff pressure of the group R was significantly lower than that of the group P. The difference of cuff pressure is considered due to the difference in cuff compliance.

  18. Management of recurrent ischial pressure sore with gracilis muscle flap and V-Y profunda femoris artery perforator-based flap.

    PubMed

    Lee, Su-Shin; Huang, Shu-Hung; Chen, Meng-Chum; Chang, Kao-Ping; Lai, Chung-Sheng; Lin, Sin-Daw

    2009-10-01

    Inappropriate seating has been implicated as a major contributing factor in ischial pressure-sore recurrence. During their lifetime, paraplegic patients may require several flaps for closure of the same or some other adjacent pressure sore. Despite a wide variety of flap reconstruction options being described, the ischium remains the most difficult pressure-sore site to treat. From June 1998 to July 2006, there were 253 pressure-sore patients operated upon at Kaohsiung Medical University Hospital. Ten patients (eight men and two women) suffered from recurrent ischial pressure sores, and all of them received more than one flap reconstruction for the ischial defect. For the treatment of the recurrent ischial pressure sore, gracilis muscle flap and readvancement of the V-Y profunda femoris artery perforator-based flap were used to fill the dead space as well as cover the defect. Among these 10 recurrent ischial pressure-sore patients, six of them had suffered bilateral ischial ulcers. Eight of them had previous sacral pressure sores. In all, 32 flap reconstruction procedures were performed on these 10 patients. Unfortunately, one patient had recurrent grade II bilateral ischial pressure sores after 11 months of ulcer-free period. The other nine patients had no recurrence noted, and enjoyed their lives with an average 27.2 months ulcer-free period (range 9-53 months). The fasciocutaneous flap provides a higher mechanical resistance than the detached and transposed muscle. However, for the recurrent ischial ulcer patients, readvancement of the perforator-based fasciocutaneous flap alone cannot provide adequate bulk to obliterate the 'dead space' after debridement of the bursa and the surrounding necrotic tissue. By combining the readvancement of V-Y profunda femoris artery perforator-based fasciocutaneous flap and gracilis muscle flap, these recurrent ischial ulcers will heal without complication. Recurrence of ulceration often develops despite successful flap closure

  19. Using a case-mix-adjusted pressure sore incidence study in a surgical directorate to improve patient outcomes in pressure ulcer prevention.

    PubMed

    Watret, L

    1999-10-01

    The Glasgow Acute Clinical Audit Sub-Committee on Pressure Sores has previously carried out studies of incidence of pressure ulcers in the medical directorates and case-mix-adjusted the figures for length of hospital stay and risk assessment score. Case-mix classification is 'classification of people or treatment placed into groups using characteristics associated with condition, treatment or outcome that can be used to predict need, resource, use of outcomes'. In this instance, crude pressure ulcer incidence figures may be adjusted for length of hospital stay and pressure sore risk assessment score, and stratified into groups, which allows like to be compared with like. The value in case-mix-adjusted figures lies in repeating the exercise, thus determining the trend for individual areas and assessing whether improvement in the quality of care is being achieved. This is more positive than creation of 'league tables' comparing simultaneous studies in a number of areas. The figures showed that there was no statistically significant difference between surgical directorates in trusts with regard to risk assessment scores and length of hospital stay. Gathering data on the incidence of pressure ulcer development allows us to identify where new sores are occurring, but does not critically analyse the nursing intervention taken in individual cases, which identifies preventive strategies. The Glasgow group's primary aim was to gather data on case-mix-adjusted incidence of pressure damage; the secondary objectives were to scrutinize the data to gather more general information on intrinsic and extrinsic factors which may predispose to pressure ulcer development. The study was carried out in the surgical directorate. Findings showed that incidence was low (1.1%), with the majority of sores being superficial. There was a correlation between pressure ulcer development and incontinence, evidence of under-utilization of moving and handling aids for prevention of pressure ulcers

  20. Economic assessment of pressure sore prevention using a computerized mattress system in patients with spinal cord injury.

    PubMed

    Catz, Amiram; Zifroni, Avi; Philo, Ora

    2005-11-15

    To assess the economic profitability of a new computerized mattress system in patients with spinal cord injuries (SCI) by comparison with two other alternatives, as an example of the use of a quantitative approach for decision-making in choosing between alternatives for sore prevention. The cost of achieving one day without signs of impending pressure sore was compared between the alternative options using cost minimization analysis. Savings in nursing costs for the three options were calculated for cost-benefit analysis. A foam mattress system is significantly cheaper than the other examined alternatives, and if the nursing manpower cost is constant and the nursing staff is capable of performing sufficient repositioning, this system would achieve the desired medical outcome at a minimal cost. However, if the nursing staff cannot perform sufficient repositioning, or if the use of nursing manpower can be adjusted to the actual need, then it is the computerized mattress system that achieves the desired outcome at the minimal cost. In this case, less than 20 New Israeli Shekels (NIS) per day spent on the equipment save NIS 45 per day in labor costs. The economic evaluation indicates that the computerized mattress system is advisable for patients with SCI who require assistance for repositioning, but its profitability depends on the employment terms of the nursing manpower. In addition, other possible alternative pressure management systems should be examined, and additional research may be needed to determine the optimal combination of such systems for a spinal cord rehabilitation department.

  1. Canker Sores

    MedlinePlus

    Canker sores are small, round sores in your mouth. They can be on the inside of your cheek, under your tongue, or in the back of your throat. They usually have a red edge and a gray center. They can be quite painful. They are ...

  2. Predictive power of the Braden scale for pressure sore risk in adult critical care patients: a comprehensive review.

    PubMed

    Cox, Jill

    2012-01-01

    Critical care is designed for managing the sickest patients within our healthcare system. Multiple factors associated with an increased likelihood of pressure ulcer development have been investigated in the critical care population. Nevertheless, there is a lack of consensus regarding which of these factors poses the greatest risk for pressure ulceration. While the Braden scale for pressure sore risk is the most commonly used tool for measuring pressure ulcer risk in the United States, research focusing on the cumulative Braden Scale score and subscale scores is lacking in the critical care population. This author conducted a literature review on pressure ulcer risk assessment in the critical care population, to include the predictive value of both the total score and the subscale scores. In this review, the subscales sensory perception, mobility, moisture, and friction/shear were found to be associated with an increased likelihood of pressure ulcer development; in contrast, the Activity and Nutrition subscales were not found to predict pressure ulcer development in this population. In order to more precisely quantify risk in the critically ill population, modification of the Braden scale or development of a critical care specific risk assessment tool may be indicated.

  3. Old age, malnutrition, and pressure sores: an ill-fated alliance.

    PubMed

    Mathus-Vliegen, Elisabeth M H

    2004-04-01

    Wound healing is a complex, tightly regulated process, consisting of three distinct phases. In each phase of wound healing, energy and macronutrients are required. Moreover, animal studies have established a specific role for certain nutrients such as the amino acid arginine, the vitamins A, B, and C, and the elements selenium, manganese, zinc, and copper. Chronic wounds such as pressure ulcers have extensively been investigated as to the risk of development, prevention, and cure. Here, the combination of old age, malnutrition, and pressure ulcers is highly unfortunate. Energy and nutrients, such as proteins and vitamins B and C, being deficient at old age are needed in pressure ulcer healing. Malnutrition is associated with skin anergy and with immobility because of mental apathy and muscle wasting. Severe malnutrition, impaired oral intake, and the risk of pressure ulcer formation appear to be interrelated. Adequate nutrition may reverse the underfed state unless an underlying wasting disease was present and appeared to reduce the prevalence and incidence in cross-sectional and prospective observational studies. However, attempts to prevent pressure ulcers by nutritional intervention were divergent in outcome, reflecting the difficulties to meet the daily requirements in elderly persons and the lack of knowledge about true nutritional needs in wound healing. The consumption of a diet high in protein and energy may promote pressure ulcer healing. When considering nutritional support, oral supplementation should be weighted against tube feeding, as the associated morbidity of tube feeding, i.e., diarrhea, fecal incontinence, and restricted mobility being in themselves risk factors for pressure ulcers, might obscure the favorable effects of adequate nutrition. Despite the evidence in animal studies, none of the above-mentioned specific nutrients promoted the healing of pressure ulcers in humans. Therefore, the attention should be focused on early recognition of a

  4. Increased technetium uptake is not equivalent to muscle necrosis: scintigraphic, morphological and intramuscular pressure analyses of sore muscles after exercise

    NASA Technical Reports Server (NTRS)

    Crenshaw, A. G.; Friden, J.; Hargens, A. R.; Lang, G. H.; Thornell, L. E.

    1993-01-01

    A scintigraphic technique employing technetium pyrophosphate uptake was used to identify the area of skeletal muscle damage in the lower leg of four runners 24 h after an ultramarathon footrace (160 km). Most of the race had been run downhill which incorporated an extensive amount of eccentric work. Soreness was diffuse throughout the posterior region of the lower leg. In order to interpret what increased technetium uptake reflects and to express extreme endurance related damages, a biopsy was taken from the 3-D position of abnormal uptake. In addition, intramuscular pressures were determined in the deep posterior compartment. Scintigraphs revealed increased technetium pyrophosphate uptake in the medial portion of the gastrocnemius muscle. For 3698 fibres analysed, 33 fibres (1%) were necrotic, while a few other fibres were either atrophic or irregular shaped. A cluster of necrotic fibres occurred at the fascicular periphery for one subject and fibre type grouping occurred for another. Ultrastructural analysis revealed Z-line streaming near many capillaries and variously altered subsarcolemmal mitochondria including some with paracrystalline inclusions. The majority of the capillaries included thickened and irregular shaped endothelial cells. Intramuscular pressures of the deep posterior compartment were slightly elevated (12-15 mmHg) for three of the four subjects. Increased technetium uptake following extreme endurance running does not just reflect muscle necrosis but also subtle fibre abnormalities. Collectively, these pathological findings are attributed to relative ischaemia occurring during the race and during pre-race training, whereas, intramuscular pressure elevations associated with muscle soreness are attributed to mechanical stress caused by extensive eccentric work during the race.

  5. Perforator flaps in late-stage pressure sore treatment: outcome analysis of 11-year-long experience with 143 patients.

    PubMed

    Grassetti, Luca; Scalise, Alessandro; Lazzeri, Davide; Carle, Flavia; Agostini, Tommaso; Gesuita, Rosaria; Di Benedetto, Giovanni

    2014-12-01

    In the last decade, perforator flaps have been introduced for the treatment of pressure ulcers as alternative to the more popular myocutaneous local flaps. We reviewed our single-team 11-year experience in order to define whether real advantages could be achieved. We analyzed 143 patients undergoing perforator flap surgery for a single late-stage pressure sore. All patients underwent the same protocol treatment. Data regarding associated pathologies, demographics, complications, healing, and hospitalization times were collected. Ninety-three percent of 143 patients were white Caucasian, and 61% were men, with median age of 51 years. Of 143 stage 4 ulcers, 46.2% were ischial, 42.7% sacral, and 11.2% trochanteric. The most common diagnosis was traumatic paraplegia/tetraplegia (74.9%); no significant difference was found in diagnosis distribution and in ulcer location between recurrent and nonrecurrent patients. We performed 44 S-GAP, 78 I-GAP, 3 PFAP-am, and 18 PFAP-1 flaps. At 2 years' follow-up, the overall recurrence was 22.4% and new ulcer occurrence was 4.2%. Mean hospital stay was 16 days. The overall complication percentage was 22.4%, mostly due to suture-line dehiscence (14%) and distal flap necrosis (6.3%). PFAP flaps had a significant higher risk of developing recurrence than I-GAP flaps. The recurrence risk was significantly higher for subjects suffering from coronary artery disease. Late-stage pressure sore treatment with local perforator flaps can achieve reliable long-term outcomes in terms of recurrences and complications. When compared to previously published data, perforator flaps surgery decreased postoperative hospital stay (by an average of nearly 1 week), reoperations (5.6%), and occurrences.

  6. Increased technetium uptake is not equivalent to muscle necrosis: scintigraphic, morphological and intramuscular pressure analyses of sore muscles after exercise

    NASA Technical Reports Server (NTRS)

    Crenshaw, A. G.; Friden, J.; Hargens, A. R.; Lang, G. H.; Thornell, L. E.

    1993-01-01

    A scintigraphic technique employing technetium pyrophosphate uptake was used to identify the area of skeletal muscle damage in the lower leg of four runners 24 h after an ultramarathon footrace (160 km). Most of the race had been run downhill which incorporated an extensive amount of eccentric work. Soreness was diffuse throughout the posterior region of the lower leg. In order to interpret what increased technetium uptake reflects and to express extreme endurance related damages, a biopsy was taken from the 3-D position of abnormal uptake. In addition, intramuscular pressures were determined in the deep posterior compartment. Scintigraphs revealed increased technetium pyrophosphate uptake in the medial portion of the gastrocnemius muscle. For 3698 fibres analysed, 33 fibres (1%) were necrotic, while a few other fibres were either atrophic or irregular shaped. A cluster of necrotic fibres occurred at the fascicular periphery for one subject and fibre type grouping occurred for another. Ultrastructural analysis revealed Z-line streaming near many capillaries and variously altered subsarcolemmal mitochondria including some with paracrystalline inclusions. The majority of the capillaries included thickened and irregular shaped endothelial cells. Intramuscular pressures of the deep posterior compartment were slightly elevated (12-15 mmHg) for three of the four subjects. Increased technetium uptake following extreme endurance running does not just reflect muscle necrosis but also subtle fibre abnormalities. Collectively, these pathological findings are attributed to relative ischaemia occurring during the race and during pre-race training, whereas, intramuscular pressure elevations associated with muscle soreness are attributed to mechanical stress caused by extensive eccentric work during the race.

  7. Canker Sores

    MedlinePlus

    ... them is to keep an ulcer diary. By writing down when you have outbreaks of canker sores, ... of Canker Sores” Prepared by the AAOM Web Writing Group Updated 31 December 2007 Japanese Translation - 日本語訳 ...

  8. Comparison of fasciocutaneous V-Y and rotational flaps for defect coverage of sacral pressure sores: a critical single-centre appraisal.

    PubMed

    Djedovic, Gabriel; Metzler, Julia; Morandi, Evi M; Wachter, Tanja; Kühn, Shafreena; Pierer, Gerhard; Rieger, Ulrich M

    2017-03-06

    Pressure sore rates remain high in both nursing homes as well as in hospitals. Numerous surgical options are available for defect coverage in the sacral region. However, objective data is scarce as to whether a specific flap design is superior to another. Here, we aim to compare two fasciocutaneous flap designs for sacral defect coverage: the gluteal rotation flap and the gluteal V-Y flap. All primary sacral pressure sores of grades III-IV that were being covered with gluteal fasciocutaneous rotational or V-Y flaps between January 2008 and December 2014 at our institution were analysed. A total of 41 patients received a total of 52 flaps. Of these, 18 patients received 20 gluteal rotational flaps, and 23 patients received 32 V-Y flaps. Both groups were comparable with regards to demographics, comorbidities and complications. Significantly more V-Y flaps were needed to cover smaller defects. Mean length of hospital stay was significantly prolonged when surgical revision had to be carried out. Both flap designs have proven safe and reliable for defect coverage after sacral pressure sores. Gluteal rotational flaps appear to be more useful for larger defects. Both flap designs facilitate their reuse in case of pressure sore recurrence. Complication rates appear to be comparable in both designs and to the current literature.

  9. Progenitor cell therapy for sacral pressure sore: a pilot study with a novel human chronic wound model.

    PubMed

    Wettstein, Reto; Savic, Miodrag; Pierer, Gerhard; Scheufler, Oliver; Haug, Martin; Halter, Jörg; Gratwohl, Alois; Baumberger, Michael; Schaefer, Dirk Johannes; Kalbermatten, Daniel Felix

    2014-01-29

    Chronic wounds are a major health-care issue, but research is limited by the complexity and heterogeneity in terms of wound etiology as well as patient-related factors. A suitable animal model that replicates the situation in humans is not available. Therefore, the aim of the present work is to present a standardized human wound model and the data of a pilot study of topically applied progenitor cells in a sacral pressure sore. Three patients underwent cell harvest from the iliac crest at the time of the initial debridement. Forty-eight hours after bone marrow harvest and debridement, the CD34+ selected cell suspension was injected into the wound. With the aid of a laser scanner, three-dimensional analyses of wound morphometry were performed until the defect was reconstructed with a local flap 3 weeks after debridement. Decreases in volume to 60%±6% of baseline on the sham side and to 52%±3% of baseline on the cell side were measured. Histologic work-up revealed no signs of metaplastic, dysplastic, or neoplastic proliferation/differentiation after progenitor cell treatment. CD34+ cells were detected in the biopsies of day 0. The pressure sore wound model allows investigation of the initial 3 weeks after cell-based therapy. Objective outcome analysis in terms of wound volume and histology can be performed without, or with, minimal additional morbidity, and the anatomy of the sacral area allows a control and study side in the same patient. Therefore, this model can serve as a standard for wound-healing studies. ClinicalTrials.gov NCT00535548.

  10. Progenitor cell therapy for sacral pressure sore: a pilot study with a novel human chronic wound model

    PubMed Central

    2014-01-01

    Introduction Chronic wounds are a major health-care issue, but research is limited by the complexity and heterogeneity in terms of wound etiology as well as patient-related factors. A suitable animal model that replicates the situation in humans is not available. Therefore, the aim of the present work is to present a standardized human wound model and the data of a pilot study of topically applied progenitor cells in a sacral pressure sore. Methods Three patients underwent cell harvest from the iliac crest at the time of the initial debridement. Forty-eight hours after bone marrow harvest and debridement, the CD34+ selected cell suspension was injected into the wound. With the aid of a laser scanner, three-dimensional analyses of wound morphometry were performed until the defect was reconstructed with a local flap 3 weeks after debridement. Results Decreases in volume to 60% ± 6% of baseline on the sham side and to 52% ± 3% of baseline on the cell side were measured. Histologic work-up revealed no signs of metaplastic, dysplastic, or neoplastic proliferation/differentiation after progenitor cell treatment. CD34+ cells were detected in the biopsies of day 0. Conclusions The pressure sore wound model allows investigation of the initial 3 weeks after cell-based therapy. Objective outcome analysis in terms of wound volume and histology can be performed without, or with, minimal additional morbidity, and the anatomy of the sacral area allows a control and study side in the same patient. Therefore, this model can serve as a standard for wound-healing studies. Trial registration ClinicalTrials.gov NCT00535548. PMID:24476740

  11. Some practical issues in the design, monitoring and analysis of a sequential randomized trial in pressure sore prevention.

    PubMed

    Brown, J; McElvenny, D; Nixon, J; Bainbridge, J; Mason, S

    2000-12-30

    A sequential double blind (assessor and patient) triangular design was used to compare the incidence of pressure sores following elective major surgery among patients lying on a standard foam mattress with those on a dry visco-elastic polymer pad during their operation. A total of 446 patients were recruited into the trial between 1994 and 1996. Interim analyses were carried out after 181 patients were entered into the trial and then subsequently after approximately every 100 patients recruited. The trial unexpectedly reached a stopping boundary at the first interim analysis, however the Independent Data Monitoring Committee recommended continuation of the trial. They were concerned that there was a need for a larger definitive trial and about an apparent treatment by centre interaction. They required a substudy to be undertaken to further validate the subjective endpoint, and that further sensitivity analyses of the main trail endpoint should be carried out in the second interim analysis. The trial was stopped at the third interim analysis when again a stopping boundary was crossed indicating that the gel pad was associated with significantly fewer pressure sores than the standard mattress (log odds ratio -0.7, (95 per cent confidence interval (CI), -1.28, -0.11), p=0.02) (estimate CI, p-value adjusted for group sequential conduct). The design, monitoring and analysis of this trial will be presented as an example of the practical problems or non-problems encountered for the local hospitals, for the trials unit, for the data monitoring committee and for the funding committee. Copyright 2000 John Wiley & Sons, Ltd.

  12. [Reducing patient pressure sore incidence in the surgical intensive care unit].

    PubMed

    Chung, Hui-Ting; Shu, Ling-Hui; Pan, Chao-Chun; Yang, Shu-Yen; Chen, Wan-I

    2011-06-01

    Pressure ulcers were an increasingly significant problem among patients in the authors' ward. The eight patients diagnosed with pressure ulcers (0.42% of all inpatients) during the first half of 2009 represented a 140% increase over the first half of 2008 (0.28% of all inpatients). This project was designed to reduce pressure ulcer incidence in the surgical intensive care unit (ICU) to 0.05%. Intervention measures included: 1) holding professional training on preventing pressure ulcers; 2) specifying appropriate patient turnover tools; 3) creating and distributing to nurses a proper turnover technique and positioning manual; 4) creating and distributing to nurses a comprehensive patient skin inspection checklist; and 5) organizing a permanent pressure ulcer care quality and audit committee. Pressure ulcer incidence fell from 0.42% to 0.04% following implementation of the methods. Results demonstrate the effectiveness of using the proposed methods to reduce pressure ulcer incidence and enhance nursing care quality.

  13. Translation and testing of the Risk Assessment Pressure Ulcer Sore scale used among residents in Norwegian nursing homes

    PubMed Central

    Fossum, Mariann; Söderhamn, Olle; Cliffordson, Christina; Söderhamn, Ulrika

    2012-01-01

    Objective The purpose of this study was to translate and test the psychometric properties of the Norwegian-language version of the Risk Assessment Pressure Sore (RAPS) scale. Background Risk assessment scales for pressure ulcer (PU) prevention have become an aspect of quality improvement in healthcare, but their effectiveness depends on the reliability and validity of the scale. Methods  A convenience sample of 481 residents in 15 nursing homes in rural Norway was included between January and June 2007. The English-language version of the RAPS scale was translated into Norwegian, and this scale was used to collect the data, including a skin examination. The number of PUs and grades were documented. Reliability was assessed in a small group of 26 residents and construct validity in the total study group. Results Equivalence between two assessments regarding total scores of the RAPS scale was reflected in an intraclass correlation coefficient (ICC) of 0.95. Construct validity was supported, and the RAPS scale could define groups with expected low and high scores. Further evidence of construct validity was shown in a confirmatory factor analysis. Conclusion The Norwegian version of the RAPS scale has shown sufficient psychometric properties to be considered a reliable and valid scale for identifying risk of PUs among nursing home residents. However, further testing is needed. PMID:23100445

  14. Translation and testing of the Risk Assessment Pressure Ulcer Sore scale used among residents in Norwegian nursing homes.

    PubMed

    Fossum, Mariann; Söderhamn, Olle; Cliffordson, Christina; Söderhamn, Ulrika

    2012-01-01

    The purpose of this study was to translate and test the psychometric properties of the Norwegian-language version of the Risk Assessment Pressure Sore (RAPS) scale. Risk assessment scales for pressure ulcer (PU) prevention have become an aspect of quality improvement in healthcare, but their effectiveness depends on the reliability and validity of the scale.  A convenience sample of 481 residents in 15 nursing homes in rural Norway was included between January and June 2007. The English-language version of the RAPS scale was translated into Norwegian, and this scale was used to collect the data, including a skin examination. The number of PUs and grades were documented. Reliability was assessed in a small group of 26 residents and construct validity in the total study group. Equivalence between two assessments regarding total scores of the RAPS scale was reflected in an intraclass correlation coefficient (ICC) of 0.95. Construct validity was supported, and the RAPS scale could define groups with expected low and high scores. Further evidence of construct validity was shown in a confirmatory factor analysis. The Norwegian version of the RAPS scale has shown sufficient psychometric properties to be considered a reliable and valid scale for identifying risk of PUs among nursing home residents. However, further testing is needed.

  15. Cold Sores

    MedlinePlus

    ... causes oral herpes, or cold sores. Type 1 herpes virus infects more than half of the U.S. population by the time they reach their 20s. Type 2 usually affects the genital area Some people have no symptoms from the ...

  16. Canker Sore

    MedlinePlus

    ... or baking soda rinse (dissolve 1 teaspoon of baking soda in 1/2 cup warm water). Dab a small amount of milk of magnesia on your canker sore a few times a day. Avoid abrasive, acidic or spicy foods that can cause further ...

  17. Doreen Norton OBE, MSc, SRN, FRCN (1922-2007): Pioneer who revolutionised pressure sore management and geriatric nursing to international acclaim.

    PubMed

    Denham, Michael J

    2016-05-01

    Doreen Norton was a delightful, widely respected nurse who devoted her life to improving the care of elderly people. She researched the neglected problem of pressure sores, revolutionised their nursing care, and thus achieved international fame. Her Pressure Sore Scale was established as a management tool and is still used today. She was a key member of the design team that produced the 'King's Fund Bed', researched equipment required on geriatric wards, assessed all geriatric long stay units in Scotland and established research as a valuable nursing tool within her profession and health authorities. She lectured extensively and her publications attracted worldwide acclamation. After her retirement, she was subsequently appointed to the world's first Chair of Gerontological Nursing in Cleveland, Ohio.

  18. Sepsis of the hip due to pressure sore in spinal cord injured patients: advocacy for a one-stage surgical procedure.

    PubMed

    Le Fort, M; Rome-Saulnier, J; Lejeune, F; Bellier-Waast, F; Touchais, S; Kieny, P; Duteille, F; Perrouin-Verbe, B

    2014-11-04

    Study design:Retrospective study reporting characteristics and management of septic arthritis of the hip due to pressure sores in spinal cord-injured patients.Objectives:To describe clinical and biological data of septic arthritis of the hip and its treating management.Setting:The database of the regional SCI referral center, Nantes, France.Methods:We retrospectively collected data from 33 cases of septic arthritis of the hip in the medical files of 26 patients.Results:We analyzed 33 cases of septic arthritis of the hip treated in one French referent center for spinal cord-injured patients from January 1988 to December 2009. Most patients had a thoracic complete paraplegia and nearly two-third (17 out of 26) had no systematic follow-up. In 25 out of 33 cases, the septic arthritis of the hip was due to a trochanteric pressure sore. The causal pressure sore was most frequently associated with a persistent drainage. The standard radiological examination led to the diagnosis in 30 cases and, in 7 questionable cases, magnetic resonance imaging was more contributory. Surgery always consisted of a wide carcinological-like excision and of a subtrochanteric proximal femoral resection including both greater and lesser trochanters. A musculocutaneous flap was realized for all cases and the choice of the muscle depended on the localization of the causal pressure sore but also of the remaining choices, as most of the patients had already undergone a prior surgery. An antibiotic treatment was adapted to multiple samples during surgery.Conclusion:We do advocate for a one-stage procedure including a subtrochanteric proximal femoral resection and a musculocutaneous flap.Spinal Cord advance online publication, 4 November 2014; doi:10.1038/sc.2014.170.

  19. Which medical device and/or which local treatment for prevention in patients with risk factors for pressure sores in 2012? Developing French guidelines for clinical practice.

    PubMed

    Nicolas, B; Moiziard, A S; Barrois, B; Colin, D; Michel, J M; Passadori, Y; Ribinik, P

    2012-10-01

    Implementation of a prevention strategy after the identification of risk factors is essential at the entrance in a care unit or in a medical-social unit. Determine which medical devices and which treatments may be used in order to prevent pressure sore in 2012. Systematic review of the literature using databases: Pascal, Biomed, PubMed, and Cochrane library between 2000 and 2010. Nursing care including use of soft product, non-irritating for the cleaning, hydration of the skin with emollients, protection of fragile skin in case of incontinence by applying a skin protector and application of dressings in front of bony prominences to reduce shear forces, remain valid (level C). Nursing cares and use of dressing in patients with high risks of pressure sores are the responsibility of the nurses. The engagement of health care teams involves screening of risk factors and the knowledge of treatments and local devices. Local preventive treatment in a patient with risk factors of pressure sore is of great interest at entrance in a care unit or in a medical-social unit. Copyright © 2012. Published by Elsevier Masson SAS.

  20. Multisite Web-based training in using the Braden Scale to predict pressure sore risk.

    PubMed

    Magnan, Morris A; Maklebust, JoAnn

    2008-03-01

    To evaluate the effect of a Web-based Braden Scale training module on nurses' knowledge of pressure-ulcer risk assessment and prevention. Pre-experimental, posttest-only design. Web-based learning environment. Registered nurses (N=1391) working at 3 medical centers in the Midwest. Primary outcomes of interest were reliability and competence associated with using the Braden Scale for pressure-ulcer risk assessment. Secondary outcomes of interest focused on program evaluation, specifically nurses' perceptions of program adequacy and ease of use. After training, nurses correctly rated Braden Scale level of risk 82.6% of the time. Numeric ratings for Braden subscales were generally more reliable when case-study data indicated extreme risk levels (generally not at-risk level, high-risk level, and very high level) than when data indicated midlevels of risk (mild-risk level and moderate-risk level). Nurses' knowledge of appropriate risk-based preventive interventions was high, but correlated poorly with the ability to correctly assign numeric ratings to Braden subscales. Web-based training alone may not ensure reliable, competent estimates of pressure-ulcer risk for patients at all risk levels. Other strategies, such as clinical practice with expert supervision, should be considered. Further research is needed to clarify the links between scoring Braden subscales correctly and selecting appropriate risk-based preventive interventions.

  1. Use of Perforator-Based Fasciocutaneous Flaps for Pressure Sore Reconstruction: Single-Perforator-Based Versus Multiple-Perforator-Based Flaps.

    PubMed

    Chih-Hsun, Lin; Ma, Hsu

    2016-08-01

    A perforator-based fasciocutaneous flap is an alternative type of flap for pressure sore reconstruction. The aim of the present study was to determine whether a single-perforator-based flap or a multiple-perforator-based flap is better for pressure sore reconstruction. We reviewed the general data and postoperative complications in patients who received single-perforator-based or multiple-perforator-based fasciocutaneous flaps for pressure sore reconstruction between July 2009 and July 2012. No differences in general data, comorbidities, wound locations, flap sizes (73.9 vs. 67.0 cm(2), P = 0.455), and operative times were noted between the single-perforator-based and multiple-perforator-based flap groups. The flap rotation arc was larger in the single-perforator-based flap group than in the multiple-perforator-based flap group; however, the difference in the rotation arc was not significant (99.2° vs. 55.5°, respectively; P = 0.199). Two patients had total flap necrosis and one had partial flap necrosis in the single-perforator-based flap group. None of flap necrosis was noted in the multiple-perforator-based flap group; however, no significant differences in major complications were noted between the two groups. All donor sites underwent primary closure. This is the first clinical patient-matched research that considered the number of perforators and the rotation arc in applying perforator-based fasciocutaneous flaps in wound reconstruction. The results showed that the number of perforators is not the determinant factor of surgical outcome of the use of perforator-based fasciocutaneous flaps in pressure sore reconstruction. Thus, whether a single- or a multiple-perforator-based fasciocutaneous flap is used for flap perfusion does not jeopardize the operation. These results emphasize the reliability and convenience of using freestyle design of perforator-based flaps for pressure sore reconstruction. The design and clinical utility of the flaps have the

  2. Inter- and intrarater reliability of the Waterlow pressure sore risk scale: a systematic review.

    PubMed

    Kottner, Jan; Dassen, Theo; Tannen, Antje

    2009-03-01

    The Waterlow scale is one of the pressure ulcer risk assessment scales which are frequently criticised for their low reliability. It is widely used in the United Kingdom, Europe and all over the world. The study objectives were to systematically review and evaluate inter- and intrarater reliability and/or agreement of the whole Waterlow scale and its single items. The overall aim was to find out if the Waterlow scale is applicable to daily clinical practice. Systematic review. MEDLINE (1985-June 2008), EMBASE (1985-June 2008), CINAHL (1985-June 2008) and World Wide Web. Selections of relevant studies, data extractions, recalculations of reliability and agreement coefficients, and study quality assessments were independently conducted by two researchers. Designs, methods and results of relevant studies were systematically described, compared and interpreted. Eight research reports were identified containing the results of nine inter- and intrarater reliability and agreement studies. Only three studies were considered as high quality studies. The Waterlow scale in clinical practice was examined in four studies. Interrater agreement for the total score varied between 0% and 57%. Taking into account any differences of up to two points the total score agreement increased to up to 86%. Median ranges of differences among raters scoring single items were high for 'poor nutrition', 'skin type', and 'mobility'. Recalculated intrarater reliability for one researcher was ICC(2,1)=0.97 (95% C.I. 0.94-0.98). Empirical evidence is rare regarding reliability and agreement among nurses when using the Waterlow scale in clinical practice. Interrater agreement for the total score is comparable to other pressure ulcer risk assessment scales. The interrater reliability has never been examined. Therefore, evaluation of reliability and agreement and evaluation of the applicability of the Waterlow scale to clinical practice are limited. It is very likely that the items 'poor nutrition

  3. Pressure induced polymerization of Formates

    NASA Astrophysics Data System (ADS)

    Tschauner, Oliver

    2004-03-01

    The discovery of pressure induced polymerization of CO2 inspired us to search for C-O based chain structures forming at high pressure. We used salts of carboxylic acids as starting materials and exposed them to pressures between 10 and 30 GPa. Upon heating to temperatures above 1800 K we observed deprotonation and significant changes in the Raman shifts of C-O streching modes. Structure analysis based on powder diffraction patterns collected at sector 16 of the APS showed formation of extended C-O chain structures with the cations of the salts residing in the interchain spaces. These new high pressure polymers are interesting by their mechanical strength and provide basic molecular patterns of organic metallic conductors.

  4. Prospective and randomised evaluation of the protease-modulating effect of oxidised regenerated cellulose/collagen matrix treatment in pressure sore ulcers.

    PubMed

    Kloeters, Oliver; Unglaub, Frank; de Laat, Erik; van Abeelen, Marjolijn; Ulrich, Dietmar

    2016-12-01

    In chronic wounds, excess levels and activity of proteases such as elastase and plasmin have been detected. Oxidised regenerated cellulose/collagen matrix (ORC/collagen matrix) has been reported to ameliorate the wound microenvironment by binding and inactivating excess proteases in wound exudates. In this study, the levels and activity of elastase and plasmin in wound exudates of pressure sore ulcers were measured to determine the beneficial effect of ORC/collagen matrix treatment compared with control treatment with a foam dressing. A total of 33 patients with pressure sores were enrolled in the study and were followed up for 12 weeks after treatment. Ten control patients were treated with a foam hydropolymer dressing (TIELLE(®) , Systagenix), and the remaining 23 patients were treated with ORC/collagen matrix plus the foam dressing (TIELLE(®) , Systagenix) on top. Wound assessments were carried out over 12 weeks on a weekly basis, with dressing changes twice a week. Ulcers were photographed and wound exudates were collected on admission and at days 5, 14 and then every 14 days to provide a visual record of any changes in appearance of the ulcer and healing rate and for biochemical analysis of the wound. The levels and activity of elastase and plasmin were measured in wound exudates. Statistical analysis was performed using ANOVA and Bonferroni's post hoc test with P-values <0·05 considered to be significant. Compared with controls, ORC/collagen matrix-treated pressure sore wounds showed a significant faster healing rate, which positively correlated with a decreased activity of elastase and plasmin in wound exudates. No signs of infection or intolerance to the ORC/collagen matrix were observed. © 2015 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

  5. Preventing Pressure Sores

    MedlinePlus Videos and Cool Tools

    ... Question Videos by Family Relationship Videos by Experts Resources The Short List Government Programs Family and Caregiver ... by Family Relationship Videos by Spinal Cord Experts Resources Forums Peer Counseling Blog About Us Contact Donate ...

  6. [Prevention of heel pressure sores with a foam body-support device. A randomized controlled trial in a medical intensive care unit].

    PubMed

    Cadue, Jean-François; Karolewicz, Stéphane; Tardy, Catherine; Barrault, Claudie; Robert, René; Pourrat, Olivier

    2008-01-01

    To assess in a prospective controlled study the efficacy and safety of a specific foam body-support device designed as to prevent heel pressure ulcers. A randomization table was used to allocate 70 patients into 2 groups. The control group was treated with our standard pressure sore prevention protocol (half-seated position, water-mattress and preventive massages 6 times a day); the experimental group was treated with the same standard protocol as well as with the foam body-support device being evaluated. Patients were included if their Waterlow score was >10, indicating a high risk of developing pressure ulcers and if they had no skin lesion on the heels. Foam devices, covered with jersey, were constructed for the legs and allowed the heels to be free of any contact with the bed; another foam block was arranged perpendicularly to the first, in contact with the soles, to prevent ankles from assuming an equinus position (to prevent a dropfoot condition). The principal criterion for efficacy was the number of irreversible skin lesions on the heel (that is, beyond the stage of blanching hyperemia, reversible after finger pressure); these lesions were assessed every day until the end of the study (up to 30 days). The number of irreversible heel pressure ulcers was lower in the experimental (3 patients, 8.6%) than in the control group (19 patients, 55.4%) (p<0.0001). Mean time without any pressure ulcer was higher in the experimental group (5.6 days, compared with 2.8 days, p=0.01). The groups did not differ in the number of pressure sores on the sacrum and leg. An anatomical foam body-support is effective in preventing heel pressure ulcers in patients on a medical intensive care unit and is well tolerated.

  7. Which medical device and/or which local treatment are to be used, as of 2012, in patients with infected pressure sore? Developing French guidelines for clinical practice.

    PubMed

    Arzt, H; Fromantin, I; Ribinik, P; Barrois, B; Colin, D; Michel, J-M; Passadori, Y

    2012-10-01

    Taking care of a patient with an infected pressure sore necessitates a diagnosis allowing for a suitable treatment strategy. To choose the dressings and topical antimicrobial agents that can be used as of 2012 in treatment of an infected pressure sore. A systematic review of the literature with queries to the databases Pascal Biomed, PubMed and Cochrane Library from 2000 through 2010. Diagnosis of local infection is essentially clinical. It is subsequently difficult to destroy and/or permeabilize biofilm by means of mechanical wound debridement. Application of an antimicrobial product and a disinfectant solution are of utmost importance in this respect. The studies do not demonstrate that one topical product is better than another in wound cleaning. The papers recommending antimicrobial topics lead to the conclusion that they may be interesting, but show little clinical evidence of their beneficial effects. Dressings including silver, iodine, polyhexamethylene biguanide (PHMB) and negative pressure wound therapy could likewise be of interest, but once again, existing studies present only a low level of evidence (Grade C). Local antimicrobial treatment can be used when there are signs of local infection (Grade C). Systemic antibiotic treatment is to be used when there are general medical signs of infection (Grade B). Copyright © 2012. Published by Elsevier Masson SAS.

  8. Pressure sore prevention in the critically ill: what you don't know, what you should know and why it's important.

    PubMed

    Theaker, C

    2003-06-01

    The critically ill are particularly vulnerable to pressure sore development. These expensive and often painful complications have been largely ignored for many years and the entire problem has been managed by nursing staff. Current methods for identifying patients at risk are inadequate and subjective. Scoring systems have been known to over-predict those at risk and this maybe because they frequently originate from elderly care settings. Additionally, their relevance to the critically ill has not yet been established. The use of pressure-relieving devices has become commonplace; however, there is a paucity of data from controlled clinical studies. No uniform approach in measuring the effectiveness of these devices exists. What is certain, though, is that a voluminous amount of work needs to be conducted in order to verify their continued use. It is increasingly apparent that the complex nature of pressure sore development means that it is unrealistic to expect a single discipline to manage the problem effectively. A multidisciplinary team approach is the most appropriate way to improve management in this vital area.

  9. Evaluation of lung infiltration score to predict postural hypoxemia in ventilated acute respiratory distress syndrome patients and the lateralization of skin pressure sore.

    PubMed

    Tripathi, Mukesh; Pandey, Mamta; Nepal, Bharat; Rai, Hari; Bhattarai, Balkrishna

    2009-09-01

    Mechanical ventilation with positive end expiratory pressure (PEEP) is associated with unequal aeration of lungs in acute respiratory distress syndrome (ARDS) patients. Therefore, patients may develop asymmetric atelectasis and postural hypoxemia during lateral positioning. To validate proposed lung infiltration score (LIS) based on chest x-ray to predict postural hypoxemia and lateralization of skin sores in ARDS patients. University hospital ICU. Prospective, observational study of consecutive patients. Sixteen adult patients of both genders on mechanical ventilation with PEEP for 24 to <48 hours. On chest x-ray, 6 segments were identified on each lung. The proposed LIS points (0- normal; 1- patchy infiltrates; 2- white infiltrates matching heart shadow) were assigned to each segment. Without changing ventilation parameters, supine, left and right lateral positions at 45 degrees tilt were randomly changed. At the end of 20 minutes of ventilation in each position, we observed arterial oxygen saturation, hemodynamic and arterial blood gases. Later, position change protocol (4 hourly) was practiced in ICU, and skin pressure sore grading was noted within a week of ICU stay. Nonparametric Bland and Altman correlation analysis, ANOVA and Student t test. Arterial oxygenation (PaO2/FiO2 = 313 +/- 145.6) was significantly (P<0.01) higher in better lung (lower LIS)-down position than supine (PaO2/FiO2 = 199 +/- 70.2) or a better lung-up position (PaO2/FiO2 = 165 +/- 64.8). The positioning-related arterial oxygenation was significant (P<0.05) at LIS asymmetry > or =3 between two lungs. The LIS mapping on chest x-ray was useful to differentiate between asymmetric lung disease and postural hypoxemia in ICU patients, which predisposed patients to early skin sore changes on higher LIS side.

  10. Finite element analysis of effect of softness of cushion pads on stress concentration due to an oblique load on pressure sores.

    PubMed

    Akimoto, Masataka; Oka, Toshiyuki; Oki, Koichiro; Hyakusoku, Hiko

    2007-06-01

    The concentration of mechanical stress in soft tissue can cause or worsen pressure sores. We have previously reported the results of analysis of stress concentration in soft tissue using a finite element model. In the present study, we hypothesized that even if a cushion pad was thin, it would effectively reduce horizontal loads that can increase stress concentration in soft tissue. To our knowledge, there have been no previous reports describing stress distribution in soft tissue attached to a thin cushion pad with a horizontal load. In the present study, we performed mechanical analysis of a model of a human seated on a thin cushion pad with a range of hardness values (i.e., Young's module). Two-dimensional finite element models were used to perform this analysis. Loads were applied at the upper edge of the model as oblique compulsory displacement. In all of the cushion pad models, the peak value of effective stress was less than that of the control model without a cushion pad. Also, the peak value of effective stress decreased as Young's module of the cushion pad decreased. These results suggest that use of a thin cushion pad is an effective way to prevent the development of pressure sores.

  11. Heating tar sands formations while controlling pressure

    DOEpatents

    Stegemeier, George Leo [Houston, TX; Beer, Gary Lee [Houston, TX; Zhang, Etuan [Houston, TX

    2010-01-12

    Methods for treating a tar sands formation are described herein. Methods may include heating at least a section of a hydrocarbon layer in the formation from a plurality of heaters located in the formation. A pressure in the majority of the section may be maintained below a fracture pressure of the formation. The pressure in the majority of the section may be reduced to a selected pressure after the average temperature reaches a temperature that is above 240.degree. C. and is at or below pyrolysis temperatures of hydrocarbons in the section. At least some hydrocarbon fluids may be produced from the formation.

  12. Genital sores - male

    MedlinePlus

    ... within a day of its appearance) Syphilis (small, painless open sore or ulcer [called a chancre] on ... genitals or around the anus) Lymphogranuloma venereum (small painless sore on the male genitals) Other types of ...

  13. Sore Throat (For Parents)

    MedlinePlus

    ... also can avoid sore throats by: not sharing food utensils and glasses with others avoiding contact with people who have sore ... Test: Throat Culture Flu Center What Is "PANS"? Tonsillitis Tonsils and ...

  14. Sore Throat (For Parents)

    MedlinePlus

    ... 1- to 2-Year-Old First Aid: Sore Throat KidsHealth > For Parents > First Aid: Sore Throat A A A Sore throats are common at any age and can be ... They also can be caused by a strep throat infection, although this is rare in children younger ...

  15. Coping with Cold Sores

    MedlinePlus

    ... found inside the mouth.) What Causes Cold Sores? Cold sores are caused by a virus called herpes (say: HUR-peez). Herpes is one ... the world. The medical name for the specific virus that causes cold sores is herpes simplex. There are two types ...

  16. Which medical technology and/or local treatment is most conducive, as of 2012, to pressure sore debridement ? Developing French guidelines for clinical practice.

    PubMed

    Trial, C; Pineau, J; Barrois, B; Colin, D; Michel, J-M; Passadori, Y; Ribinik, P

    2012-10-01

    Implementation of a curative strategy at the debridement stage associates systemic therapy with local therapy. To determine which medical devices and technology other than support surfaces and what kinds of drugs to use in order to cleanse a pressure ulcer in 2012. A systematic review of the literature querying the databases PASCAL Biomed, Cochrane Library and PubMed from 2000 to 2010 along with a compendium of prevailing professional practices. Pressure sore debridement is based on local care and on the use of alginates, hydrogels and hydrocolloids. The analyzed articles do not take into account any specific stage of pressure ulcer debridement. Data that might favor some kinds of dressings show a low level of evidence. Were it possible to decide on the dressing to be used for a given indication, professionals would be better able to orient and narrow down their choices. Use of alginates and hydrogels in pressure ulcer debridement is of real interest. According to expert opinion, other dressings (irrigo-absorbents, for instance) seem promising, but have yet to receive adequate scientific validation. Copyright © 2012. Published by Elsevier Masson SAS.

  17. Evaluation of the dynamic cutaneous post-ischaemic hyperaemia and thermal response in elderly subjects and in an area at risk for pressure sores.

    PubMed

    Schubert, V; Fagrell, B

    1991-03-01

    The response of skin blood cell flux (SBF) to locally applied pressure was evaluated with the laser-Doppler technique in the areas of the sacrum and the gluteus maximus muscle of geriatric patients and healthy young and elderly subjects. The SBF over the sacrum stopped at a lower external skin pressure than over the gluteus muscle in all groups studied (P less than 0.05-0.001). The SBF at rest was lower among geriatric patients and over the sacrum, with men showing the lowest value (P less than 0.001). The initial slope of the SBF curve and the peak SBF during the post-occlusive reactive hyperaemia (PRH) were lower among geriatric patients compared to younger healthy subjects (P less than 0.05-0.01) over both areas studied. During the last part of the PRH response rhythmic oscillations started, known as vasomotion. The mean skin temperature at rest was higher over the sacrum (P less than 0.001) than over the gluteus area, but no difference was found between the groups. The temperature increase during the PRH was larger over the gluteus muscle (P less than 0.01) than over the sacrum area in the healthy subjects. Among the patients the temperature increase was larger over the gluteus only during the first half of the PRH, after which the temperature increased most over the sacrum. It is concluded that SBF and skin temperature show different responses in microvascular reactivity to external pressure in elderly vs. younger subjects and also between sexes. The described technique may be useful in clinical practice for predicting the risk of pressure sores in different areas and subjects.

  18. Cold Sores (HSV-1)

    MedlinePlus

    ... A Week of Healthy Breakfasts Shyness Cold Sores (HSV-1) KidsHealth > For Teens > Cold Sores (HSV-1) A A A What's in this article? ... or around a person's lips, are caused by herpes simplex virus-1 (HSV-1) . But they don't ...

  19. Con: Ambulatory blood pressure measurement in patients receiving haemodialysis: a sore arm and a waste of time?

    PubMed

    Jardine, Alan G

    2015-09-01

    Ambulatory blood pressure monitoring (ABPM) has become popular in the investigation and management of patients with essential hypertension. In patients receiving haemodialysis, ABPM identifies patients who may fare worse in the long term. However, the available studies are small, and when conventional risk factors are included, there is no added value to ABPM over conventional BP measurements. In haemodialysis, ABPM remains an experimental investigation, and in the absence of specific, evidence-based targets for blood pressure in this population, it would be better to invest in large-scale trials to provide specific blood pressure targets and strategies, rather than concentrating on an alternative technique for blood pressure measurement. © The Author 2015. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

  20. What is the best support surface in prevention and treatment, as of 2012, for a patient at risk and/or suffering from pressure ulcer sore? Developing French guidelines for clinical practice.

    PubMed

    Colin, D; Rochet, J-M; Ribinik, P; Barrois, B; Passadori, Y; Michel, J-M

    2012-10-01

    The use of support surfaces in the prevention and treatment of pressure ulcers prevention is an important part of care for a patient at risk and/or suffering from sore(s). Define which support surfaces to use in prevention and treatment of at-risk and/or pressure sore patients. A systematic review of the literature querying the several Pascal Biomed, PubMed and Cochrane Library databases from 2000 through 2010. RESULTS (GRADE A): In prevention, a structured foam mattress is more efficient than a standard hospital mattress. An alternating pressure mattress is more effective than a visco-elastic mattress limiting the occurrence heel pressure ulcers, but those that do occur are more serious. A low-air-loss bed is more efficient than a mixed pulsating air mattress in prevention of heel pressure ulcers. Some types of sheepskin can reduce sacral pressure ulcer incidence in orthopedic patients. Use of an overlay on an operating table limits the occurrence of peroperative and postoperative pressure ulcers. An air-fluidized bed improves pressure ulcer healing. The data in the literature are not always relevant and do not suffice to dictate a clinician's choices. We are compelled to recognize the methodological limitations of many studies, the lack of corporate interest in conducting such studies and the relatively small number of available trials. However, the effectiveness of some support surfaces reaches a sufficient level of evidence, especially when they are associated with postural, hydration and nutritional measures. Support surfaces are recommended in prevention and treatment of patients at risk and/or already suffering from pressure ulcer, and their use should constitute part of an overall preventive or curative strategy. Copyright © 2012. Published by Elsevier Masson SAS.

  1. Predictive validity and reliability of the Turkish version of the risk assessment pressure sore scale in intensive care patients: results of a prospective study.

    PubMed

    Günes, Ülkü Yapucu; Efteli, Elçin

    2015-04-01

    Multiple pressure ulcer (PU) risk assessment instruments have been developed and tested, but there is no general consensus on which instrument to use for specific patient populations and care settings. The purpose of this study was to determine the reliability and predictive validity of the Turkish version of the Risk Assessment Pressure Sore (RAPS) instrument, which includes 12 variables--5 from the modified Norton Scale, 3 from the Braden Scale, and 3 from other research results--for use in intensive care unit (ICU) patients. The English version of the RAPS instrument was translated into Turkish and tested for internal consistency and predictive validity (sensitivity, specificity, positive predictive value, and negative predictive value) using a convenience sample of 122 patients consecutively admitted to an ICU unit in Turkey. The patients were assessed within 24 hours of admission, and after that, once a week until the development of a PU or discharge from the unit. The incidence of PUs in this population was 23%. The majority of ulcers that developed were Stage I. Internal consistency of the RAPS tool was adequate (Cronbach's α = 0.81). The best balance between sensitivity and specificity for ICU patients was reached at a cut-off point of ≤ 27 (ie, sensitivity = 74.2%, specificity = 31.8%, positive predictive value = 38.7%, and negative predictive value 91.3%). This is lower than the cut-off point reported in other studies of the RAPS scale. In this population of ICU patients, the RAPS scale was found to have acceptable reliability and poor validity. Additional studies to evaluate the predictive validity and reliability of the RAPS scale in other patient populations and care settings are needed.

  2. Sore throat and hoarseness after total intravenous anaesthesia.

    PubMed

    Maruyama, K; Sakai, H; Miyazawa, H; Toda, N; Iinuma, Y; Mochizuki, N; Hara, K; Otagiri, T

    2004-04-01

    Sore throat and hoarseness are common complications, but these have not been studied after total i.v. anaesthesia. We prospectively studied 418 surgical patients, aged 15-92 yr, after total i.v. anaesthesia with propofol, fentanyl and ketamine to assess possible factors associated with sore throat and hoarseness. We found sore throat in 50% and hoarseness in 55% of patients immediately after surgery. This decreased to 25% for sore throat and 24% for hoarseness on the day after surgery. Both sore throat and hoarseness were more common in females and when lidocaine spray had been used. Cricoid pressure during laryngoscopy was inversely associated with the risk of sore throat. Knowledge of these factors may reduce postoperative throat complications, and improve patient satisfaction.

  3. Lidocaine for preventing postoperative sore throat.

    PubMed

    Tanaka, Yuu; Nakayama, Takeo; Nishimori, Mina; Sato, Yuki; Furuya, Hitoshi

    2009-07-08

    Sore throat is a common side effect of general anaesthesia and is reported by between 30% and 70% of patients after tracheal intubation. The likelihood of a sore throat varies with the type, diameter, and cuff pressure of the endotracheal tube used. If intubation is essential, it may be helpful to give drugs prophylactically to alleviate postoperative sore throat. Local anaesthetics and steroids have been used for this purpose. The objective of this review was to evaluate the effectiveness and any harms of topical and systematic lidocaine for the prevention of postoperative sore throat in adults undergoing endotracheal intubation as part of general anaesthesia. We searched CENTRAL (The Cochrane Library 2007, Issue 3), MEDLINE (January 1966 to June 2007), and EMBASE (1980 to June 2007). We also contacted manufacturers and researchers in the field. We included randomized controlled trials of topical and systemic prophylactic lidocaine therapy versus control (using air or saline) that reported on the risk and severity of postoperative sore throat as an outcome. Two authors independently assessed trial quality and extracted data. We contacted study authors for additional information, such as the risk of adverse effects. We included 1232 patients from 15 studies; 672 patients received topical or systemic lidocaine therapy and 560 patients were allocated to the control group. Both the topical and systemic lidocaine therapy significantly reduced the risk of postoperative sore throat (risk ratio (RR) 0.58; 95% confidence interval (CI) 0.41 to 0.82). To evaluate the severity of sore throat on a visual analogue scale (VAS), 219 patients received topical or systemic lidocaine therapy and 152 patients were allocated to the control groups. The severity of sore throat was reduced (mean difference (MD) -11.9; 95% CI -16.44 to -7.32), an effect that neared statistical significance. The adverse effects of lidocaine were not reported in these studies. Our systematic review

  4. Pharyngitis - sore throat

    MedlinePlus

    ... antibiotics if: A strep test or culture is positive. Your provider cannot diagnose strep throat by symptoms ... alone. A culture for chlamydia or gonorrhea is positive. Sore throat caused by the flu (influenza) may ...

  5. Genital sores - female

    MedlinePlus

    ... painless sores. Less common infections such as chancroid , granuloma inguinale , molluscum contagiosum , and syphilis may also cause ... Elsevier; 2016:chap 16. Read More Chancroid Donovanosis (granuloma inguinale) Genital herpes Genital warts Melanoma Molluscum contagiosum ...

  6. Sore Throat: Treatment

    MedlinePlus

    ... include: Slippery elm Licorice root Marshmallow root Honeysuckle flower and other Chinese medicine herbs Preparing for your appointment If you or your child has a sore throat, make an appointment with your family doctor or your ...

  7. Abnormally high formation pressures, Potwar Plateau, Pakistan

    USGS Publications Warehouse

    Law, B.E.; Shah, S.H.A.; Malik, M.A.

    1998-01-01

    Abnormally high formation pressures in the Potwar Plateau of north-central Pakistan are major obstacles to oil and gas exploration. Severe drilling problems associated with high pressures have, in some cases, prevented adequate evaluation of reservoirs and significantly increased drilling costs. Previous investigations of abnormal pressure in the Potwar Plateau have only identified abnormal pressures in Neogene rocks. We have identified two distinct pressure regimes in this Himalayan foreland fold and thrust belt basin: one in Neogene rocks and another in pre-Neogene rocks. Pore pressures in Neogene rocks are as high as lithostatic and are interpreted to be due to tectonic compression and compaction disequilibrium associated with high rates of sedimentation. Pore pressure gradients in pre-Neogene rocks are generally less than those in Neogene rocks, commonly ranging from 0.5 to 0.7 psi/ft (11.3 to 15.8 kPa/m) and are most likely due to a combination of tectonic compression and hydrocarbon generation. The top of abnormally high pressure is highly variable and doesn't appear to be related to any specific lithologic seal. Consequently, attempts to predict the depth to the top of overpressure prior to drilling are precluded.

  8. Multi-disciplinary management of complex pressure sore reconstruction: 5-year review of experience in a spinal injuries centre.

    PubMed

    Thomson, C H; Choudry, M; White, C; Mecci, M; Siddiqui, H

    2017-02-01

    INTRODUCTION In our regional spinal injuries unit, complex pressure ulcer reconstruction is facilitated by a monthly multidisciplinary team clinic. This study reviews a series of the more complex of these patients who underwent surgery as a joint case between plastics and other surgical specialties, aiming to provide descriptive data as well as share the experience of treating these complex wounds. MATERIALS AND METHODS Patients operated on as a joint case from 2010 to 2014 were identified through a locally held database and hospital records were then retrospectively reviewed for perioperative variables. Descriptive statistics were collected. RESULTS 12 patients underwent 15 procedures as a joint collaboration between plastic surgery and other surgical specialties: one with spinal surgery, 12 with orthopaedic and two with both orthopaedic and urology involvement. Ischial and trochanteric wounds accounted for 88% of cases with five Girdlestone procedures being performed and 12 requiring soft-tissue flap reconstruction. Mean operative time was 3.8hours. Four patients required high-dependency care and 13 patients received long-term antibiotics. Only three minor complications (20%) were seen with postoperative wound dehiscence. DISCUSSION The multidisciplinary team clinic allows careful assessment and selection of patients appropriate for surgical reconstruction and to help match expectations and limitations imposed by surgery, which are likely to influence their current lifestyle in this largely independent patient group. Collaboration with other specialties gives the best surgical outcome both for the present episode as well as leaving avenues open for potential future reconstruction.

  9. Sore Throat: Symptoms and Causes

    MedlinePlus

    ... more than two weeks Viruses that cause the common cold and flu (influenza) also cause most sore throats. ... Viral illnesses that cause a sore throat include: Common cold Flu (influenza) Mononucleosis (mono) Measles Chickenpox Croup — a ...

  10. Postoperative sore throat: a systematic review.

    PubMed

    El-Boghdadly, K; Bailey, C R; Wiles, M D

    2016-06-01

    Postoperative sore throat has a reported incidence of up to 62% following general anaesthesia. In adults undergoing tracheal intubation, female sex, younger age, pre-existing lung disease, prolonged duration of anaesthesia and the presence of a blood-stained tracheal tube on extubation are associated with the greatest risk. Tracheal intubation without neuromuscular blockade, use of double-lumen tubes, as well as high tracheal tube cuff pressures may also increase the risk of postoperative sore throat. The expertise of the anaesthetist performing tracheal intubation appears to have no influence on the incidence in adults, although it may in children. In adults, the i-gel(™) supraglottic airway device results in a lower incidence of postoperative sore throat. Cuffed supraglottic airway devices should be inflated sufficiently to obtain an adequate seal and intracuff pressure should be monitored. Children with respiratory tract disease are at increased risk. The use of supraglottic airway devices, oral, rather than nasal, tracheal intubation and cuffed, rather than uncuffed, tracheal tubes have benefit in reducing the incidence of postoperative sore throat in children. Limiting both tracheal tube and supraglottic airway device cuff pressure may also reduce the incidence. © 2016 The Association of Anaesthetists of Great Britain and Ireland.

  11. A quantitative analysis of microcirculation in sore-prone pressure areas on conventional and pressure relief hospital mattresses using laser Doppler flowmetry and tissue spectrophotometry.

    PubMed

    Rothenberger, Jens; Krauss, Sabrina; Held, Manuel; Bender, Dominik; Schaller, Hans-Eberhard; Rahmanian-Schwarz, Afshin; Constantinescu, Mihai Adrian; Jaminet, Patrick

    2014-11-01

    Pressure ulcers are associated with severe impairment for the patients and high economic load. With this study we wanted to gain more insight to the skin perfusion dynamics due to external loading. Furthermore, we evaluated the effect of different types of pressure relief mattresses. A total of 25 healthy volunteers were enrolled in the study. Perfusion dynamics of the sacral and the heel area were assessed using the O2C-device, which combines a laser light, to determine blood flow, and white light to determine the relative amount of hemoglobin. Three mattresses were evaluated compared to a hard surface: a standard hospital foam mattress bed, a visco-elastic foam mattress, and an air-fluidized bed. In the heel area, only the air-fluidized bed was able to maintain the blood circulation (mean blood flow of 13.6 ± 6 versus 3.9 ± 3 AU and mean relative amount of hemoglobin of 44.0 ± 14 versus 32.7 ± 12 AU.) In the sacral area, all used mattresses revealed an improvement of blood circulation compared to the hard surface. The results of this study form a more precise pattern of perfusion changes due to external loading on various pressure relief mattresses. This knowledge may reduce the incidence of pressure ulcers and may be an influencing factor in pressure relief mattress selection. Copyright © 2014 Tissue Viability Society. Published by Elsevier Ltd. All rights reserved.

  12. Canker Sores (For Parents)

    MedlinePlus

    ... open sores that have a white or yellowish coating and a red "halo" around them. They tend ... take you to a site outside of KidsHealth's control. About KidsHealth Nemours.org Reading BrightStart! Contact Us ...

  13. Factors in delayed onset muscular soreness of man.

    PubMed

    Bobbert, M F; Hollander, A P; Huijing, P A

    1986-02-01

    In this study 11 subjects performed exercise resulting in delayed onset muscular soreness in m. gastrocnemius with one leg, the experimental leg. The other leg served as control. Pre-exercise and 24, 48 and 72 h postexercise, soreness perception, resting EMG level of m. gastrocnemius, and volume and skin temperature of both legs were measured, and a leukocyte count was performed. Perception of soreness in m. gastrocnemius reported 24, 48, and 72 h postexercise was not accompanied by an increase in resting EMG level. This result indicates that soreness perception is not related to a tonic localized spasm in sore muscles. A rise in volume of the experimental leg relative to volume of the control leg was found 24, 48, and 72 h postexercise (P less than 0.05). It is suggested that the volume rise is due to edema formation in the experimental leg and that this edema formation is responsible for soreness perception. Since granulocytosis was not found, the hypothesis that edema formation reflects muscle inflammation is not substantiated.

  14. Tracheal intubation and sore throat: a mechanical explanation.

    PubMed

    Chandler, M

    2002-02-01

    Although tracheal intubation remains a valuable tool, it may result in pressure trauma and sore throat. The evidence for an association between these sequelae is not conclusive and sore throat may be caused at the time of intubation. This hypothesis was tested in a mechanical model and the results from tracheal intubation compared with those from insertion of a laryngeal mask airway, which is associated with a lower incidence of sore throat. Use of the model suggests that the tracheal tube and laryngeal mask airway impinge on the pharyngeal wall in different manners and involve different mechanisms for their conformation to the upper airway, but that in a static situation, the forces exerted on the pharyngeal wall are low with both devices. It also suggests that the incidence of sore throat should be lower for softer and smaller tracheal tubes and that the standard 'Magill' curve (radius of curvature 140 +/- 20 mm) is about optimum for the average airway.

  15. Sore Throat: Self-Management

    MedlinePlus

    Sore throat Self-management By Mayo Clinic Staff Regardless of the cause of your sore throat, these at-home care strategies can help you ... rest your voice. Drink fluids. Fluids keep the throat moist and prevent dehydration. Avoid caffeine and alcohol, ...

  16. Factors in delayed muscle soreness.

    PubMed

    Abraham, W M

    1977-01-01

    The possible causes of delayed muscle soreness which occur 24 to 48 hr after exercise were examined from three different approaches, each designed to test an existing hypothesis. Surface electromyograms were used to evaluate the muscle spasm theory; the possibility of actual muscle cell damage was monitored by the presence of myoglobinuria, while the ratio of hydroxyproline/creatinine (OHP/Cr) in 24 hr urine collection was used as a marker for connective tissue involvement. In the first study, although all volunteers developed muscle soreness 24 and 48 hr after exercise, no change in the EMG activity of the sore muscles was observed. Myoglobin excretion was found in 88% of the subjects who developed soreness. However, in a second study, 92% of the subject who performed both moderate and heavy exercise but did not develop muscle soreness had myoglobinuria. In contrast, during a third experiment subjects on gelatin-free diets showed an increase (P less than .1) in the OHP/Cr between control (.020+/-.001) and 48 hr post-exercise (.002+/-.001, X+/-SE). Soreness resulted in all cases. When the OHP/Cr value is taken for the day of maximal soreness, the post-exercise mean increases to .024+/-.001 and the level of significance rises (P less than .005). These observations support the concept that exercise induced soreness may be related to disruption of the connective tissue elements in the muscle and/or their attachments.

  17. Location-dependent depth and undermining formation of pressure ulcers.

    PubMed

    Takahashi, Yoshiko; Isogai, Zenzo; Mizokami, Fumihiro; Furuta, Katsunori; Nemoto, Tetsuya; Kanoh, Hiroyuki; Yoneda, Masahiko

    2013-08-01

    We examined the location-specific properties of pressure ulcers, focusing on depth and undermining formation, which are often unfavorable factors for ulcer healing. We conducted a retrospective observational study of 2 independent databases on pressure ulcers. Databases from a 200-bed hospital (database A) and a 300-bed hospital (database B) were collected during different time periods. Relationships between ulcer location, ulcer depth, and undermining formation were analyzed. All pressure ulcers were accurately diagnosed and classified according to their locations. A total of 282 pressure ulcers in 189 patients from database A and 232 pressure ulcers in 154 patients from database B were analyzed. It was found that pressure ulcers primarily developed over the sacrum. Ratio of stages III and IV pressure ulcers was high in pressure ulcers of the foot, ankle, and crus on the lower leg. Among the deep pressure ulcers, undermining formation was frequently observed on the greater trochanter, ilium, and sacrum. In contrast, pressure ulcers of the foot, ankle, and crus did not exhibit undermining formation. Our results revealed marked differences in pressure ulcer properties depending on their location. Factors affecting depth and undermining of pressure ulcers appear to be related to anatomical and physical properties of the bone and subcutaneous tissue. Copyright © 2013 Tissue Viability Society. Published by Elsevier Ltd. All rights reserved.

  18. Herpes Simplex Virus (Cold Sores)

    MedlinePlus

    ... not always necessary. In these tests, a tissue scraping of the sores may be examined under the ... Academy of Pediatrics) The information contained on this Web site should not be used as a substitute ...

  19. Design of mechanical interface to re-distribute excess pressure to prevent the formation of decubitus ulcers in bed ridden patients.

    PubMed

    Nageswaran, Sharmila; Vijayakumar, Rekha; Sivarasu, Sudesh

    2015-08-01

    Pressure ulcers are the major problem in the stroke management and rehabilitation. Prevention of pressure ulcer is of keen interest and is achieved by frequently changing the position of patient on the mattress. However, the care needs to be intensive to address this issue; else it would lead to pressure ulcer or bed sores formation. Skin surface over the bony prominences provide comparatively more pressure than the other regions. Therefore they are called as pressure vulnerable regions. Skin over these regions is more susceptible for formation of ulcers. An engineering approach is needed to shift the accumulating pressure from the pressure vulnerable regions. Although pressure sensed in these region would be more than that of which sensed in other regions, shifting protocol has to be designed to channelize or to grade the pressure shift in order to avoid any injuries to the non pressure vulnerable region. This paper aims at devising one such protocol using MATLab and thereby designing the layout of mattress using Pro/Engineer: the number of partitions needed to cover the entire surface of the skin that is in contact with the mattress.

  20. Causes of sore throat after intubation: a prospective observational study of multiple anesthesia variables.

    PubMed

    Levin, Phillip D; Chrysostomos, Chrysostomou; Ibarra, Carlos A; Ledot, Stephan; Naito, Daigo; Weissman, Charles; Avidan, Alexander

    2017-06-01

    Sore throat is common after intubation for surgery. This observational study investigated cuff pressure and a large range of clinical covariates to explore the etiology of sore throat. Approximately 24 hours after surgery six questions relating to pain, upper airway symptoms and sore throat were delivered to patients who had undergone intubation. Sore throat was correlated with demographics, anesthesia variables and cuff pressure (measured for a subset of patients). Sore throat was reported by 270/518 (52%) patients with VAS Score 45.9±25.1 (range 0-100). Sore throat patients were significantly younger, had a lower ASA status, were more frequently female, had shorter surgeries and lower nitrous oxide exposure, had a higher proportion of smaller tracheal tubes (7.5 mm internal diameter vs. 8 mm), had a higher incidence of nasogastric drainage, higher propofol doses and a higher usage of ketorolac. Decreasing age (odds ratio 0.976, 95% confidence intervals 0.961-0.992, P=0.003) and the presence of a nasogastric tube when the questionnaire was delivered (OR 1.83, 95% CI: 1.06-3.14, P=0.03) remained significant predictors of sore throat on multivariate analysis. Mean cuff pressure (measured for 160 patients) was 56.8±41.9 mmHg. Cuff pressure was similar amongst patients with and without sore throat (57±46 vs. 53±38 mmHg, P=0.58). There was no correlation between cuff pressure and severity of sore throat (r=0.004, P=0.37). Only age and the presence of a nasogastric tube after surgery were significant predictors for sore throat. This result contradicts most other studies of cuff pressure where fewer covariates were measured.

  1. Lidocaine for preventing postoperative sore throat.

    PubMed

    Tanaka, Yuu; Nakayama, Takeo; Nishimori, Mina; Tsujimura, Yuka; Kawaguchi, Masahiko; Sato, Yuki

    2015-07-14

    Sore throat is a common side-effect of general anaesthesia and is reported by between 30% and 70% of patients after tracheal intubation. The likelihood of a sore throat varies with the type, diameter, and cuff pressure of the endotracheal tube used. If intubation is essential, it may be helpful to give drugs prophylactically to alleviate postoperative sore throat. Local anaesthetics and steroids have been used for this purpose. This review was originally published in 2009 and was updated in 2015. The objective of this review was to evaluate the efficacy and any harm caused by topical and systemic lidocaine used prophylactically to prevent postoperative sore throat in adults undergoing general anaesthesia with endotracheal intubation. We searched CENTRAL (The Cochrane Library 2013, Issue 9), MEDLINE (January 1966 to October 2013), and EMBASE (1980 to October 2013). We also contacted manufacturers and researchers in the field. The original search was undertaken in June 2007. We reran the search in February 2015 and found four studies of interest. We will deal with those studies when we next update the review. We included randomized controlled trials (RCTs) of topical and systemic prophylactic lidocaine therapy versus control (using air or saline) that reported on the risk and severity of postoperative sore throat as an outcome. Two authors independently assessed trial quality and extracted data. We contacted study authors for additional information, such as the risk of any adverse effects. We included 19 studies involving 1940 participants in this updated review. Of those 1940 participants, 952 received topical or systemic lidocaine therapy and 795 were allocated to the control groups. Topical and systemic lidocaine therapy appeared to reduce the risk of postoperative sore throat (16 studies, 1774 participants, risk ratio (RR) was 0.64 (95% confidence interval (CI) 0.48 to 0.85), the quality of the evidence was low), although when only high-quality trials were

  2. Basaltic Pressure Ridges: Formation and Relationship to Flow Emplacement

    NASA Technical Reports Server (NTRS)

    Theilig, E.

    1985-01-01

    Pressure ridges and pressure plateau are common but not ubiquitous surface features on terrestrial basaltic lava flows and may reflect a specific flow emplacement mechanism. Many of the ridges are large enough to be detected on high-resolution orbital images; therefore, understanding these features could provide a means for interpreting volcanic flows on the mechanism of pressure ridge formation and how their formation relates to flow emplacement. Results from detailed field studies indicate that pressure ridges and plateaus: (1) are emplaced as individual flow lobes, (2) can be composed of primary or secondary material, (3) are dependent on duration and volume of activity within the flow unit, (4) are penecontemporaneous in formation, and (5) are indicative of slowly advancing flows with numerous flow lobes continuously forming and overriding each other.

  3. Ozone formation in pulsed SDBD in a wide pressure range

    NASA Astrophysics Data System (ADS)

    Starikovskiy, Andrey; Nudnova, Maryia; mipt Team

    2011-10-01

    Ozone concentration in surface anode-directed DBD for wide pressure range (150 - 1300 torr) was experimentally measured. Voltage and pressure effect were investigated. Reduced electric field was measured for anode-directed and cathode-directed SDBD. E/n values in cathode-directed SDBD is higher than in cathode-directed on 50 percent at atmospheric pressure. E/n value increase leads to decrease the rate of oxygen dissociation and Ozone formation at lower pressures. Radiating region thickness of sliding discharge was measured. Typical thickness of radiating zone is 0.4-1.0 mm within pressure range 220-740 torr. It was shown that high-voltage pulsed nanosecond discharge due to high E/n value produces less Ozone with compare to other discharges. Kinetic model was proposed to describe Ozone formation in the pulsed nanosecond SDBD.

  4. Magnetically Orchestrated Formation of Diamond at Lower Temperatures and Pressures

    NASA Astrophysics Data System (ADS)

    Little, Reginald B.; Lochner, Eric; Goddard, Robert

    2005-01-01

    Man's curiosity and fascination with diamonds date back to ancient times. The knowledge of the many properties of diamond is recorded during Biblical times. Antoine Lavoisier determined the composition of diamond by burning in O2 to form CO2. With the then existing awareness of graphite as carbon, the race began to convert graphite to diamond. The selective chemical synthesis of diamond has been pursued by Cagniard, Hannay, Moisson and Parson. On the basis of the thermodynamically predicted equilibrium line of diamond and graphite, P W Bridgman attempted extraordinary conditions of high temperature (>2200°C) and pressure (>100,000 atm) for the allotropic conversion of graphite to diamond. H T Hall was the first to successfully form bulk diamond by realizing the kinetic restrictions to Bridgman's (thermodynamic) high pressure high temperature direct allotropic conversion. Moreover, Hall identified catalysts for the faster kinetics of diamond formation. H M Strong determined the import of the liquid catalyst during Hall's catalytic synthesis. W G Eversole discovered the slow metastable low pressure diamond formation by pyrolytic chemical vapor deposition with the molecular hydrogen etching of the rapidly forming stable graphitic carbon. J C Angus determined the import of atomic hydrogen for faster etching for faster diamond growth at low pressure. S Matsumoto has developed plasma and hot filament technology for faster hydrogen and carbon radical generations at low pressure for faster diamond formation. However the metastable low pressure chemical vapor depositions by plasma and hot filament are prone to polycrystalline films. From Bridgman to Hall to Eversole, Angus and Matsumoto, much knowledge has developed of the importance of pressure, temperature, transition metal catalyst, liquid state of metal (metal radicals atoms) and the carbon radical intermediates for diamond synthesis. Here we advance this understanding of diamond formation by demonstrating the external

  5. Pressure effect on soot formation in turbulent diffusion flames.

    PubMed

    Roditcheva, O V; Bai, X S

    2001-01-01

    Soot formation in a methane air turbulent jet diffusion flame is investigated numerically using a semi-empirical model. The temperature, density and species (the soot precursor C2H2) fields are calculated using detailed chemical kinetic mechanism based on the flamelet library approach. The influence of pressure on the soot formation and the behavior of the semi-empirical model in different flame situations are investigated. It is found that the flame shape and the flame temperature can be well predicted by the flamelet library approach. The calculated soot yield is mostly sensitive to the soot surface growth rate and the increase of pressure. The increase of pressure leads to the increase of soot surface growth rate and therefore to the increase of soot volume fraction. By adjusting a model constant in the soot surface growth rate, the soot emissions in both pressure p = 1 atm and p = 3 atm are properly simulated by the current semi-empirical soot model.

  6. Fluid pressures in overpressured Forbes Formation, Sacramento Valley, California

    SciTech Connect

    Price, C.A.

    1988-03-01

    Initial shut-in pressures obtained from drill-stem tests, mud weights, and shale-compaction data were used to determine the formation fluid-pressure distribution in the southern Grimes gas field. Initial shut-in pressures in overpressured gas-bearing Forbes sandstones range from 3252 to 6660 psi. Pressure gradients range from 0.446 to 0.745 psi/ft. Regional initial shut-in pressure data suggest that (1) pressures appear to increase dramatically at approximately 7700 ft (2339 m) below sea level, (2) pressures generally increase with depth above 8200 ft (2491 m), but are highly variable below 8200 ft, and (3) the approximate depth to the top of geopressures is 5500 ft (1671 m) below sea level. Fluid pressures generally decrease from northeast to southwest through the region and from north to south within the westernmost fault block. Mud-weight data give maximum pressures for any depth. The maximum possible pressure gradient in the southern Grimes gas field is 0.847 psi/ft. The relationship between initial shut-in pressure and the amount of gas tested during drill-stem tests was also examined. More than 3000 MCFGD was tested only where the fluid pressure gradient was between 0.510 and 0.700 psi/ft. Twice as many drill-stem tests showed little or no gas when the fluid-pressure gradient exceeded 0.700 psi/ft than when it was less than 0.700 psi/ft. Fluid-pressure gradients greater than 0.700 psi/ft were encountered only below 8000 ft (2430 m); therefore, the probability of testing, and possibly producing, 3000 MCFGD decreases below 8000 ft.

  7. Staphylococcus aureus and sore nipples.

    PubMed Central

    Livingstone, V. H.; Willis, C. E.; Berkowitz, J.

    1996-01-01

    OBJECTIVE: To correlate clinical symptoms and signs of sore nipples with the presence of Staphylococcus aureus and to determine the probability of mothers having S aureus-infected nipples when these local symptoms and signs are found. DESIGN: Two cohorts of consecutive patients were enrolled regardless of presenting complaint. A questionnaire was administered to determine the presence and severity of sore nipples. Objective findings on breast examination were documented. A nipple swab was taken for culture and sensitivity. SETTING: Breastfeeding clinic serving patients referred by family physicians, pediatricians, and community health nurses. PATIENTS: A sample of 227 breastfeeding mothers was collected in two cohorts. MAIN OUTCOME MEASURES: Answers to questions about sore nipples, objective findings from physical examination, and results from nipple swabs. RESULTS: Most subjects (51%) had sore nipples, and 45% of subjects had objective findings on examination; 23% of subjects had a positive nipple swab culture; 15% grew S aureus on culture. The risk of having S aureus colonization was 4.8 times greater if nipple pain was moderate or severe rather than mild. A break in nipple integument associated with cracks, fissures, ulcers, or pus gave a 35% chance of having S aureus colonization, five times greater than when the integument was intact. CONCLUSIONS: The study showed that mothers with infants younger than 1 month who complained of moderate to severe nipple pain and who had cracks, fissures, ulcers, or exudates had a 64% chance of having positive skin cultures and a 54% chance of having S aureus colonization. PMID:8653033

  8. Sore shoulder in physical practice.

    PubMed

    Pecar, Dzemal; Mujić, Muzafer; Pecar, Muris

    2005-05-01

    Sore shoulder or shoulder region is frequently encountered in general population. According to reference data prevalence ranges between 15 and 20% in 40-45 age group. A weak bone support enables extensive excursions of this joint and simultaneously reduces its stability. We analyzed successfulness of sore shoulder treatment in a sample of 1115 patients treated in the Center for physical medicine and rehabilitation between 1996 and 2004. All the patients reported to the Center either in acute phase or in the phase of chronic state exacerbation, with limited function that was graded on the scale 0 to 5. Type and kind of sore shoulder cause was determined by clinical examination and, where needed, by X-ray. Of the total number of cases, 33 patients did not report for follow up examination, 166 patients were forwarded to other physical therapy centers for treatment so the final analysis included 916 patients (82%) whose treatment success was evaluated on the scale 0 to 5. In 659 (58%) patients the inflammation of musculus biceps long tendon was identified as a cause of sore shoulder. The least frequent cause was the blow syndrome (impingement)--20 (2%). In 666 patients (73%) the problem was resolved by local instillation of depo corticosteroids (Betamethason 7 mg) so the physical treatment was not required.

  9. Giant planet formation at the pressure maxima of protoplanetary disks

    NASA Astrophysics Data System (ADS)

    Guilera, O. M.; Sándor, Zs.

    2017-07-01

    Context. In the classical core-accretion planet-formation scenario, rapid inward migration and accretion timescales of kilometer size planetesimals may not favor the formation of massive cores of giant planets before the dissipation of protoplanetary disks. On the other hand, the existence of pressure maxima in the disk could act as migration traps and locations for solid material accumulation, favoring the formation of massive cores. Aims: We aim to study the radial drift of pebbles and planetesimals and planet migration at pressure maxima in a protoplanetary disk and their implications for the formation of massive cores as triggering a gaseous runaway accretion phase. Methods: The time evolution of a viscosity driven accretion disk is solved numerically introducing a a dead zone as a low-viscosity region in the protoplanetary disk. A population of pebbles and planetesimals evolving by radial drift and accretion by the planets is also considered. Finally, the embryos embedded in the disk grow by the simultaneous accretion of pebbles, planetesimals, and the surrounding gas. Results: Our simulations show that the pressure maxima generated at the edges of the low-viscosity region of the disk act as planet migration traps, and that the pebble and planetesimal surface densities are significantly increased due to the radial drift towards pressure maxima locations. However, our simulations also show that migration-trap locations and solid-material-accumulation locations are not exactly at the same positions. Thus, a planet's semi-major axis oscillations around zero torque locations predicted by MHD and HD simulations are needed for the planet to accrete all the available material accumulated at the pressure maxima. Conclusions: Pressure maxima generated at the edges of a low-viscosity region of a protoplanetary disk seem to be preferential locations for the formation and trap of massive cores.

  10. Magnesium and Ketamine Gargle and Postoperative Sore Throat

    PubMed Central

    Teymourian, Houman; Mohajerani, Seyed Amir; Farahbod, Alireza

    2015-01-01

    Background: Postoperative sore throat is one of the most common complications after endotracheal intubation. Both Ketamine and magnesium can block N-methyl-D-aspartic acid (NMDA) receptors and provide central and local analgesia. Objectives: To compare the effect of magnesium sulfate and ketamine gargle on the incidence and severity of postoperative sore throat. Patients and Methods: A total of 100 patients candidate for emergency acute appendicitis surgery were enrolled in the study. Patients in ketamine group received ketamine gargle (0.5 mg/kg) and magnesium group received magnesium sulfate gargle (20 mg/kg up to 30 mL dextrose water 20%) 15 minutes before the operation. Patient complaint of postoperative sore throat, and its severity measured by visual analogue scale (VAS) were recorded at baseline in recovery room, and then 2, 4, and 24 hours after operation. Results: There were no significant differences between age, sex, and body mass index (BMI) between two groups of patients. Hemodynamics of patients, including blood pressure, respiratory rate, oxygen saturation %, and conscious state were not significantly different (P > 0.05). Number of patients with sore throat were significantly lower in magnesium group compared to ketamine group at 2 (P = 0.032), 4 (P = 0.02), and 24 hours (P = 0.01) after the operation. Sore throat pain score (VAS) was significantly lower in magnesium group compared to ketamine group at 2 (P = 0.019), 4 (P = 0.028), and 24 hours (P = 0.014) after the operation. Conclusions: Magnesium at low dose decreases sore throat and pain severity more effectively compared to ketamine gargle. PMID:26161316

  11. Magnesium and Ketamine Gargle and Postoperative Sore Throat.

    PubMed

    Teymourian, Houman; Mohajerani, Seyed Amir; Farahbod, Alireza

    2015-06-01

    Postoperative sore throat is one of the most common complications after endotracheal intubation. Both Ketamine and magnesium can block N-methyl-D-aspartic acid (NMDA) receptors and provide central and local analgesia. To compare the effect of magnesium sulfate and ketamine gargle on the incidence and severity of postoperative sore throat. A total of 100 patients candidate for emergency acute appendicitis surgery were enrolled in the study. Patients in ketamine group received ketamine gargle (0.5 mg/kg) and magnesium group received magnesium sulfate gargle (20 mg/kg up to 30 mL dextrose water 20%) 15 minutes before the operation. Patient complaint of postoperative sore throat, and its severity measured by visual analogue scale (VAS) were recorded at baseline in recovery room, and then 2, 4, and 24 hours after operation. There were no significant differences between age, sex, and body mass index (BMI) between two groups of patients. Hemodynamics of patients, including blood pressure, respiratory rate, oxygen saturation %, and conscious state were not significantly different (P > 0.05). Number of patients with sore throat were significantly lower in magnesium group compared to ketamine group at 2 (P = 0.032), 4 (P = 0.02), and 24 hours (P = 0.01) after the operation. Sore throat pain score (VAS) was significantly lower in magnesium group compared to ketamine group at 2 (P = 0.019), 4 (P = 0.028), and 24 hours (P = 0.014) after the operation. Magnesium at low dose decreases sore throat and pain severity more effectively compared to ketamine gargle.

  12. Predictors of postoperative sore throat in intubated children.

    PubMed

    Calder, Alyson; Hegarty, Mary; Erb, Thomas O; von Ungern-Sternberg, Britta S

    2012-03-01

    The incidence of postoperative sore throat (POST) following intubation is not well defined in the pediatric population. The etiology is multifactorial and includes impairment of subglottic mucosal perfusion and edema as a result of the pressures exerted by cuffed or uncuffed tubes. To determine the incidence of, and risk factors for, POST in intubated children undergoing elective day-case surgery. Five hundred patients aged 3-16 years were studied prospectively. Endotracheal tube (ETT) choice (cuffed or uncuffed) was left to the anesthetist. The cuff was inflated either until loss of audible leak or to a determined pressure using a cuff manometer. The research team then measured the cuff pressure (CP). POST incidence and intensity was determined by interviewing patients prior to discharge from the same day procedure unit. Chi-square testing and stepwise logistic regression were used to determine the predictors of POST. Of the 111 (22%) children developed a sore throat, 19 (3.8%) a sore neck, and 5 (1%) a sore jaw. 19% of patients with cuffed ETTs complained of sore throat compared with 37% of those intubated with an uncuffed ETT. The incidence of POST increased with CP; 0-10% at 0 cmH(2)O, 4% at 11-20 cmH(2)O, 20% at 21-30 cmH(2)O, 68% at CP 31-40 cmH(2)O, and 96% at CP >40 cmH(2)O. The ETT CP and use of uncuffed ETTs were univariate predictors of POST. Children intubated with uncuffed ETTs are more likely to have POST. ETT CP is positively correlated with the incidence of POST. When using cuffed ETTs, CP should be routinely measured intraoperatively. © 2011 Blackwell Publishing Ltd.

  13. Fluid Pressure Anomalies in Shallow Intraplate Argillaceous Formations

    NASA Astrophysics Data System (ADS)

    Neuzil, C.

    2015-12-01

    Fluid transport in shales and other argillaceous formations is difficult to study because these materials often have extremely low permeability. However, recent investigations have revealed a number of instances of apparently isolated highs or lows in pore fluid potential in shallow (< ~ 1 km depth) argillaceous formations in intraplate settings. The presence (or absence) of such pressure anomalies may provide clues to fluid flow. Formations with the pressure anomalies are distinguished by (1) smaller ratios of hydraulic conductivity to formation thickness and (2) smaller hydraulic (or pressure) diffusivities than those without anomalies. This is consistent with water-saturated transient Darcian flow caused by strain at rates of ~ 10-17 to 10-16 s-1, by significant perturbing events in the past 104 to 106 years or by some combination of the two. Plausible causes include erosional downwasting, tectonic strain, and glaciation. In this conceptualization the anomalies constrain formation-scale flow properties, flow history, and local geological forcing in the last 106 years and in particular indicate zones of low permeability (10-19 - 10-22 m2) that could be useful for isolation of nuclear waste.

  14. Pressure regimes and core formation in the accreting earth

    NASA Technical Reports Server (NTRS)

    Newsom, H. E.

    1992-01-01

    Recent work suggests that a large degree of melting is required to segregate metal from silicates, suggesting a connection with the formation of magma oceans. At low pressures metallic liquids do not wet silicate minerals, preventing the metal from aggregating into large masses that can sink. At high pressures, above 25 GPa, the dihedral angles of grains in contact with oxygen-rich metallic liquids may be reduced enough to allow percolation of metal, but this has not been confirmed. Physical models of core formation and accretion may therefore involve the formation of magma oceans and the segregation of metal at both high and low pressures. Models of core formation involving different pressure regimes are discussed as well as chemical evidence bearing on the models. Available geophysical data is ambiguous. The nature of the 670 km boundary (chemical difference or strictly phase change) between the upper and lower mantle is in doubt. There is some evidence that plumes are derived from the lower mantle, and seismic tomography strongly indicates that penetration of subducting oceanic crust into the lower mantle, but the tomography data also indicates that the 670 km discontinuity is a significant barrier to general mantle convection. The presence of the D' layer at the base of the lower mantle could be a reaction zone between the mantle and core indicating core-mantle disequilibrium, or D' layer could be subducted material. The abundance of the siderophile elements in the mantle could provide clues to the importance of high pressure processes in Earth, but partition coefficients at high pressures are only beginning to be measured.

  15. Pressure regimes and core formation in the accreting earth

    NASA Technical Reports Server (NTRS)

    Newsom, H. E.

    1992-01-01

    Recent work suggests that a large degree of melting is required to segregate metal from silicates, suggesting a connection with the formation of magma oceans. At low pressures metallic liquids do not wet silicate minerals, preventing the metal from aggregating into large masses that can sink. At high pressures, above 25 GPa, the dihedral angles of grains in contact with oxygen-rich metallic liquids may be reduced enough to allow percolation of metal, but this has not been confirmed. Physical models of core formation and accretion may therefore involve the formation of magma oceans and the segregation of metal at both high and low pressures. Models of core formation involving different pressure regimes are discussed as well as chemical evidence bearing on the models. Available geophysical data is ambiguous. The nature of the 670 km boundary (chemical difference or strictly phase change) between the upper and lower mantle is in doubt. There is some evidence that plumes are derived from the lower mantle, and seismic tomography strongly indicates that penetration of subducting oceanic crust into the lower mantle, but the tomography data also indicates that the 670 km discontinuity is a significant barrier to general mantle convection. The presence of the D' layer at the base of the lower mantle could be a reaction zone between the mantle and core indicating core-mantle disequilibrium, or D' layer could be subducted material. The abundance of the siderophile elements in the mantle could provide clues to the importance of high pressure processes in Earth, but partition coefficients at high pressures are only beginning to be measured.

  16. RELIABILITY AND APPLICABILITY OF DSTS AND BOTTOMHOLE PRESSURE MEASUREMENTS IN TEXAS GULF TERTIARY FORMATIONS

    EPA Science Inventory

    Pressure data gathered from drillstem tests (DSTs) and bottomhole pressure measurements provide critical information toward formation and can be used for an assessment of prevailing pressure regimes and their influence on the migration potential of formation fluids. Reliability o...

  17. Small Spacecraft Formation Flying Using Solar Radiation Pressure

    NASA Astrophysics Data System (ADS)

    Li, Junquan

    Solar sails have long been considered as a viable mechanism for interplanetary travel by using light from the Sun to accelerate a spacecraft without propellant. They can be used for missions studying astrophysics, heliophysics and planetary science. A formation flying system using solar radiation pressure is presented in this paper. The proposed formation flying mission uses sails due to the limited volume and power of small spacecraft. Station keeping, pitch attitude slew and yaw attitude slew are accomplished using reflectivity control devices. A nonlinear non-affine controller that provides smooth control performance is applied for formation flying of small spinning spacecraft while considering gravity gradient torques for the attitude dynamics. The performance of the formation flying is numerically demonstrated.

  18. Pressure regulates osteoclast formation and MCSF expression in marrow culture.

    PubMed

    Rubin, J; Biskobing, D; Fan, X; Rubin, C; McLeod, K; Taylor, W R

    1997-01-01

    One of the forces generated during skeletal loading is hydrostatic pressure. In the work presented here, the ability of increased pressure to influence recruitment of osteoclasts was evaluated. Murine marrow cultures, with pO2 and pCO2 kept constant, were subjected to either control (1.0 atm) or elevated (1.37 or 2.0 atm) hydrostatic pressure. As compared to control, cultures pressurized for 6 days at 1.37 atm formed less osteoclast-like cells (OCLC) (71 +/- 6% of control, P < 0.0001). A similar degree of inhibition occurred in cultures exposed to pressure during days 2-4 only (62 +/- 6%), while treatment during days 5-7 failed to inhibit the OCLC number relative to control (99 +/- 5%). Delivery of 2.0 atm pressure on days 2-4 generated 52 +/- 4% OCLC compared to control. Since macrophage colony stimulating factor (MCSF)-dependent proliferation of osteoclast precursors occurs during the pressure-sensitive period, semiquantitative RT-PCR for MCSF mRNA was performed after 3 days in 1.37 atm (days 2-4). As compared to controls, pressure caused a decrease in mRNA coding for the membrane bound form of MCSF (71.2 +/- 4% (n = 25, P < or = 0.05), while the MCSF RT-PCR product representing the secreted form showed no consistent change. This lack of response of the soluble MCSF RT-PCR product was expected, as levels of bioassayable MCSF were not altered by pressure. Extrapolating these data to in vivo conditions suggests that load-bearing will inhibit the formation of osteoclasts.

  19. Pressures in Tumuli: A Study of Tumuli Formation

    NASA Technical Reports Server (NTRS)

    Hansen, James E.

    2005-01-01

    Tumuli form via localized inflation in surface lava flows. These domed features have widths of 10-20 m, lengths of 10-150 m, and heights of 1-9 m. The axial fracture exposes a brittle crust overlying a ductilely deformed layer. The total crustal thickness is typically less than lm. Tumuli are observed on both terrestrial and martian lava flow surfaces, and provide insight on the flow formation processes and rates. Past studies have estimated the inflation pressure using a bending model for a circular, thin elastic plate, assuming small deflection (Rossi and Gudmundson, 1996). This formulation results in unrealistic pressures for some tumuli. We thus examine alternative models, including those with different shapes, bending of the ductile crust, large deflection, plastic deformation, and thick plate bending. Using the thickness of the ductile crust in the equations for thin, circular plates reduces most pressures to reasonable values. Alternative plate shapes do not cause a significant reduction in inflation pressure. Although the large deflection equations should be applicable based on the plate thickness to tumuli height ratios, they give even less realistic pressures. Tumuli with unrealistic pressures appear to have exceeded the critical bending moment, and have relatively thick crusts, requiring thick plate bending models.

  20. Pressures in Tumuli: A Study of Tumuli Formation

    NASA Technical Reports Server (NTRS)

    Hansen, James E.

    2005-01-01

    Tumuli form via localized inflation in surface lava flows. These domed features have widths of 10-20 m, lengths of 10-150 m, and heights of 1-9 m. The axial fracture exposes a brittle crust overlying a ductilely deformed layer. The total crustal thickness is typically less than lm. Tumuli are observed on both terrestrial and martian lava flow surfaces, and provide insight on the flow formation processes and rates. Past studies have estimated the inflation pressure using a bending model for a circular, thin elastic plate, assuming small deflection (Rossi and Gudmundson, 1996). This formulation results in unrealistic pressures for some tumuli. We thus examine alternative models, including those with different shapes, bending of the ductile crust, large deflection, plastic deformation, and thick plate bending. Using the thickness of the ductile crust in the equations for thin, circular plates reduces most pressures to reasonable values. Alternative plate shapes do not cause a significant reduction in inflation pressure. Although the large deflection equations should be applicable based on the plate thickness to tumuli height ratios, they give even less realistic pressures. Tumuli with unrealistic pressures appear to have exceeded the critical bending moment, and have relatively thick crusts, requiring thick plate bending models.

  1. Raman evidence for pressure-induced formation of diamondene.

    PubMed

    Martins, Luiz Gustavo Pimenta; Matos, Matheus J S; Paschoal, Alexandre R; Freire, Paulo T C; Andrade, Nadia F; Aguiar, Acrísio L; Kong, Jing; Neves, Bernardo R A; de Oliveira, Alan B; Mazzoni, Mário S C; Filho, Antonio G Souza; Cançado, Luiz Gustavo

    2017-07-21

    Despite the advanced stage of diamond thin-film technology, with applications ranging from superconductivity to biosensing, the realization of a stable and atomically thick two-dimensional diamond material, named here as diamondene, is still forthcoming. Adding to the outstanding properties of its bulk and thin-film counterparts, diamondene is predicted to be a ferromagnetic semiconductor with spin polarized bands. Here, we provide spectroscopic evidence for the formation of diamondene by performing Raman spectroscopy of double-layer graphene under high pressure. The results are explained in terms of a breakdown in the Kohn anomaly associated with the finite size of the remaining graphene sites surrounded by the diamondene matrix. Ab initio calculations and molecular dynamics simulations are employed to clarify the mechanism of diamondene formation, which requires two or more layers of graphene subjected to high pressures in the presence of specific chemical groups such as hydroxyl groups or hydrogens.The synthesis of two-dimensional diamond is the ultimate goal of diamond thin-film technology. Here, the authors perform Raman spectroscopy of bilayer graphene under pressure, and obtain spectroscopic evidence of formation of diamondene, an atomically thin form of diamond.

  2. How to care for pressure sores

    MedlinePlus

    ... blood flow, including diabetes or vascular disease Have Alzheimer disease or another condition that affects your mental state Have fragile skin Cannot control your bladder or bowels Do not get enough nutrition

  3. Interpreting fluid pressure anomalies in shallow intraplate argillaceous formations

    USGS Publications Warehouse

    Neuzil, Christopher E.

    2015-01-01

    Investigations have revealed several instances of apparently isolated highs or lows in pore fluid potential in shallow (< ~ 1 km depth) argillaceous formations in intraplate settings. Formations with the pressure anomalies are distinguished by (1) smaller ratios of hydraulic conductivity to formation thickness and (2) smaller hydraulic (or pressure) diffusivities than those without anomalies. This is consistent with transient Darcian flow caused by strain at rates of ~ 10−17 to 10-16 s-1, by significant perturbing events in the past 104 to 106 annum or by some combination of the two. Plausible causes include erosional downwasting, tectonic strain, and glaciation. In this conceptualization the anomalies provide constraints on formation-scale flow properties, flow history, and local geological forcing in the last 106 annum and in particular indicate zones of low permeability (10−19–10−22 m2) that could be useful for isolation of nuclear waste.

  4. Assessment of postexercise muscle soreness by electromyography and mechanomyography.

    PubMed

    Bajaj, Prem; Madeleine, Pascal; Sjøgaard, Gisela; Arendt-Nielsen, Lars

    2002-04-01

    Mechanomyography (MMG) and electromyography (EMG) recordings from the first dorsal interosseous muscle of the hand were compared for pre-exercise and immediately after, 24-hour, and 48-hour postexercise muscle soreness. Thirteen healthy male subjects performed progressively increasing number of eccentric contractions from bout 1 (10.34 +/- 1.96) to bout 6 (27.46 +/- 5.01) (P < .03) with 116% maximum voluntary contraction (MVC) for provocation of postexercise muscle soreness. Increased areas of pain, reduced pressure pain threshold, reduced MVC, and reduced range of motion were present immediately after as compared with pre-exercise (P < .05). During intense eccentric exercise, root mean squared amplitude values of MMG increased progressively from bout 1 to bout 6, but EMG root mean squared amplitude decreased as the muscle fatigued (P < .05). Time course changes of MMG and EMG root mean squared amplitude values during single concentric, isometric, and eccentric contractions at 0%, 25%, 50%, 75%, and 100% MVC weights were measured in relation to postexercise muscle soreness. The EMG root mean squared amplitude values showed insignificant changes for concentric, isometric, and eccentric contractions between pre-exercise, immediately after, 24 hours, and 48 hours. MMG root mean squared amplitude values increased during concentric, isometric, and eccentric contractions at immediately after as compared to pre-exercise, 24 hours, and 48 hours. At immediately after, 24 hours, and 48 hours the maximum EMG root mean squared amplitude values were achieved at lower MVC levels as compared with pre-exercise (P < .05). MMG root mean squared amplitude findings suggest changes in viscoelastic properties resulting in significant mechanical muscle vibrations after intense eccentric exercise. This may suggest a role of stimulation of mechanosensitive nociceptors in relation to postexercise muscle soreness. It is concluded that simultaneous recordings of MMG and EMG may serve as an

  5. Neon-Bearing Ammonium Metal Formates: Formation and Behaviour under Pressure.

    PubMed

    Collings, Ines E; Bykova, Elena; Bykov, Maxim; Petitgirard, Sylvain; Hanfland, Michael; Paliwoda, Damian; Dubrovinsky, Leonid; Dubrovinskaia, Natalia

    2016-11-04

    The incorporation of noble gas atoms, in particular neon, into the pores of network structures is very challenging due to the weak interactions they experience with the network solid. Using high-pressure single-crystal X-ray diffraction, we demonstrate that neon atoms enter into the extended network of ammonium metal formates, thus forming compounds Nex [NH4 ][M(HCOO)3 ]. This phenomenon modifies the compressional and structural behaviours of the ammonium metal formates under pressure. The neon atoms can be clearly localised within the centre of [M(HCOO)3 ]5 cages and the total saturation of this site is achieved after ∼1.5 GPa. We find that by using argon as the pressure-transmitting medium, the inclusion inside [NH4 ][M(HCOO)3 ] is inhibited due to the larger size of the argon. This study illustrates the size selectivity of [NH4 ][M(HCOO)3 ] compounds between neon and argon insertion under pressure, and the effect of inclusion on the high-pressure behaviour of neon-bearing ammonium metal formates.

  6. Formation of silicon nanoparticles by a pressure induced nucleation mechanism

    NASA Astrophysics Data System (ADS)

    Kang, Myung-Koo; Kim, Si Joon; Kim, Hyun Jae

    2013-03-01

    Formation of silicon nanoparticles (SiNPs) was achieved using excimer laser crystallization of an amorphous Si (a-Si) thin film using a SiO2 capping layer (C/L) with improved thin-film transistor (TFT) performance due to the enlarged grain size of polycrystalline Si (poly-Si). After laser irradiation of an a-Si thin film covered with C/L, fluctuation in the surface morphology of the C/L was observed above the critical laser energy density (Ecr) with the formation of SiNPs. The grain size of the poly-Si layer after crystallization increased abruptly at the same time. A non-uniform pressure distribution beneath the SiO2 C/L was proposed for the initiation of nucleation, which is named pressure induced nucleation (PIN) mechanism. Following nucleation, the release of latent heat made it difficult for the remnant liquid Si to solidify and the volume increased due to the density difference between the liquid and solid Si. Consequently, the pressure on the liquid Si caused SiNPs to sprout through the SiO2 C/L as grains grew from the low temperature to high temperature point. This study offers not only a simple method to fabricate SiNPs with controllable size/density but also larger grain size with lower laser energy density, which leads to higher TFT performance.

  7. FILAMENT FORMATION BY ESCHERICHIA COLI AT INCREASED HYDROSTATIC PRESSURES1

    PubMed Central

    Zobell, Claude E.; Cobet, Andre B.

    1964-01-01

    ZoBell, Claude E. (University of California, La Jolla), and Andre B. Cobet. Filament formation by Escherichia coli at increased hydrostatic pressures. J. Bacteriol. 87:710–719. 1964.—The reproduction as well as the growth of Escherichia coli is retarded by hydrostatic pressures ranging from 200 to 500 atm. Reproduction was indicated by an increase in the number of cells determined by plating on EMB Agar as well as by direct microscopic counts. Growth, which is not necessarily synonymous with reproduction, was indicated by increase in dry weight and protein content of the bacterial biomass. At increased pressures, cells of three different strains of E. coli tended to form long filaments. Whereas most normal cells of E. coli that developed at 1 atm were only about 2 μ long, the mean length of those that developed at 475 atm was 2.93 μ for strain R4, 3.99 μ for strain S, and 5.82 μ for strain B cells. Nearly 90% of the bacterial biomass produced at 475 atm by strain B was found in filaments exceeding 5 μ in length; 74.7 and 16.4% of the biomass produced at 475 atm by strains S and R4, respectively, occurred in such filaments. Strain R4 formed fewer and shorter (5 to 35 μ) filaments than did the other two strains, whose filaments ranged in length from 5 to >100 μ. The bacterial biomass produced at all pressures had approximately the same content of protein and nucleic acids. But at increased pressures appreciably more ribonucleic acid (RNA) and proportionately less deoxyribonucleic acid (DNA) was found per unit of biomass. Whereas the RNA content per cell increased with cell length, the amount of DNA was nearly the same in long filaments formed at increased pressure as in cells of normal length formed at 1 atm. The inverse relationship between the concentration of DNA and cell length in all three strains of E. coli suggests that the failure of DNA to replicate at increased pressure may be responsible for a repression of cell division and consequent filament

  8. Fluid pressure and reaction zone formation at a lithological interface

    NASA Astrophysics Data System (ADS)

    Malvoisin, Benjamin; Podladchikov, Yuri

    2014-05-01

    Chemical composition variations in reaction zones between two distinct lithologies are generally interpreted in terms of chemical potential gradients and diffusion process. Concentration profiles can then be used to quantify the species diffusion coefficients or the time scale of geological events. However, chemical potential gradients are also functions of temperature and pressure and local variations of these parameters can thus potentially modify the diffusion process. In northern Corsica, a centimeter scale reaction zone formed under blueschist conditions at a serpentinite - marble contact of sedimentary origin. Three sub-zones having chemical compositions evolving from one rock end-member to another divide the reaction zone along sharp interfaces. At the reaction zone - marble interface, marble decarbonation occurs to form wollastonite and carbonaceous matter. Thermodynamic calculations for this reaction and the respective increase in density of 25 % and 7 % in the bulk rock and in the garnet minerals are interpreted as records of a pressure gradient during reaction zone formation. Moreover, the formation of a volatile-free sub-zone in the reaction zone from reaction between the H2O-bearing serpentinite and the CO2-bearing marble released fluids at the contact. The impact of such a release on the fluid pressure was modelled by considering the effects of both the rock compaction and the transport of fluid by hydraulic diffusion. Modelling results indicates that > 0.5 GPa fluid overpressure can be generated at the contact if devolatilization rates are of the order of the one experimentally measured (> 10-5 kg of fluid/m3 of rock/s). The resulting pressure gradient is of the order of magnitude of the one necessary to counter-balance the effect on chemical potential of the chemical composition variations across the contact. Finally, after the reaction has run to completion, the model predicts that fluid rapidly diffuses away from the interface which thus stops

  9. Factors Associated with Shin Soreness in Athletes.

    ERIC Educational Resources Information Center

    Myburgh, Kathryn H.; And Others

    1988-01-01

    To identify factors which cause shin soreness in athletes, 25 injured exercisers and a control group of 25 uninjured exercisers were studied. Methodology and results are presented and analyzed. Differences in calcium intake between the two groups is cited as a key factor in causing shin soreness. (JL)

  10. Electrical characteristics and formation mechanism of atmospheric pressure plasma jet

    SciTech Connect

    Liu, Lijuan; Zhang, Yu; Tian, Weijing; Meng, Ying; Ouyang, Jiting

    2014-06-16

    The behavior of atmospheric pressure plasma jet produced by a coplanar dielectric barrier discharge in helium in external electrostatic and magnetic field is investigated. Net negative charges in the plasma jet outside the tube were detected. The deflection of the plume in the external field was observed. The plasma jet is suggested to be formed by the electron beam from the temporal cathode which is accelerated by a longitudinal field induced by the surface charges on the dielectric tube or interface between the helium and ambient air. The helium flow is necessary for the jet formation in the surrounding air.

  11. Carbon onions as nanoscopic pressure cells for diamond formation

    NASA Astrophysics Data System (ADS)

    Banhart, F.; Ajayan, P. M.

    1996-08-01

    SPHERICAL particles of carbon consisting of concentric graphite-like shells ('carbon onions') can be formed by electron irradiation of graphitic carbon materials1,2. Here we report that, when such particles are heated to ~700 °C and irradiated with electrons, their cores can be transformed to diamond. Under these conditions the spacing between layers in the carbon onions decreases from 0.31 in the outer shells (slightly less than the 0.34-nm layer spacing of graphite) to about 0.22 nm in the core, indicating considerable compression towards the particle centres. We find that this compression allows diamond to nucleate-in effect the carbon onions act as nanoscopic pressure cells for diamond formation.

  12. The Role of Pressure in GMC Formation II: The H2-Pressure Relation

    NASA Astrophysics Data System (ADS)

    Blitz, Leo; Rosolowsky, Erik

    2006-10-01

    We show that the ratio of molecular to atomic gas in galaxies is determined by hydrostatic pressure and that the relation between the two is nearly linear. The pressure relation is shown to be good over 3 orders of magnitude for 14 galaxies, including dwarfs, H I-rich, and H2-rich galaxies, as well as the Milky Way. The sample spans a factor of 5 in mean metallicity. The rms scatter of individual points of the relation is only about a factor of 2 for all the galaxies, although some show much more scatter than others. Using these results, we propose a modified star formation prescription based on pressure determining the degree to which the ISM is molecular. The formulation is different in high- and low-pressure regimes, defined by whether the gas is primarily atomic or primarily molecular. This formulation can be implemented in simulations and provides a more appropriate treatment of the outer regions of spiral galaxies and molecule-poor systems, such as dwarf irregulars and damped Lyα systems.

  13. Controlling and assessing pressure conditions during treatment of tar sands formations

    DOEpatents

    Zhang, Etuan; Beer, Gary Lee

    2015-11-10

    A method for treating a tar sands formation includes providing heat to at least part of a hydrocarbon layer in the tar sands formation from a plurality of heaters located in the formation. Heat is allowed to transfer from the heaters to at least a portion of the formation. A pressure in the portion of the formation is controlled such that the pressure remains below a fracture pressure of the formation overburden while allowing the portion of the formation to heat to a selected average temperature of at least about 280.degree. C. and at most about 300.degree. C. The pressure in the portion of the formation is reduced to a selected pressure after the portion of the formation reaches the selected average temperature.

  14. Carbonate formation in Wyoming montmorillonite under high pressure carbon dioxide

    SciTech Connect

    Hur, Tae-Bong; Baltrus, John P.; Howard, Bret H.; Harbert, William P.; Romanov, Vyacheslav N.

    2013-03-01

    Carbonation reaction with silicate minerals that are common components of the host rock and cap rock within geological storage reservoirs and the associated structural deformation were investigated for better understanding of the geochemical reactions associated with geologic CO2 storage. Exposure of a model expanding clay, Wyoming montmorillonite, SWy-2, to high-pressure CO2 resulted in the formation of a mineral carbonate phase via dry CO2–clay mineral interactions at two different temperatures. The experimental evidence suggests that the properties of CO2 fluid at 70 °C provide more favorable conditions for carbonate formation at the clay surface less accessible to CO2 at 22 °C. The carbonation reaction occurred predominantly within the first couple of days of exposure to the fluid and then proceeded slower with continuing exposure. As compared to the as-received clay under the same ambient conditions, the (0 0 1) basal spacing of the clay bearing carbonates (after the CO2 exposure) was slightly expanded at a relative humidity (RH) level of 12% but it was slightly collapsed at the RH level of 40%. Finally, experimental observations suggest that the carbonation reaction occurs at the external surface as well as internal surface (interlayer) of the clay particles.

  15. Nitrite formation during low pressure ultraviolet lamp irradiation of nitrate.

    PubMed

    Lu, Ning; Gao, Nai-Yun; Deng, Yang; Li, Qing-Song

    2009-01-01

    During ultraviolet light (UV) disinfection, nitrate (NO3-) present in raw water may transform to nitrite (NO2-) that can cause serious human diseases. In this study, the formation of NO2- from NO3- was studied at different experimental conditions under the irradiation of a low-pressure ultraviolet (LPUV) lamp at 253.9 nm. The investigated experimental variables included initial NO3- concentration, solution pH (6.2-9.5), and hydrogen peroxide (H2O2) dose (0-25 mg L(-1)). Moreover, the effect of titanium dioxide (TiO2) was determined. Results showed that the formation of NO2- was enhanced at a high initial NO3- concentration and a high pH, but was inhibited, to some different degrees, by introduction of H2O2 or photocatalyst TiO2. The effect of pH on NO2- formation was probably due to the impact of hydrogen ion on the stability of several intermediates such as peroxynitrite (ONOO-), N2O3, and N2O4. And the inhibiting effects of H2O2 and TiO2 were attributable to production of additional hydroxyl radical (OH) that scavenged NO2-. At pH 9.5 and an initial NO3- concentration of 10 mg L(-1) NO3--N, the concentration of NO2- produced was above 0.1 mg L(-1) NO2--N, the Germany drinking water standard. When 25 mg L(-1) H2O2 was added, the NO2- level was decreased below the standard.

  16. [Effect of two types of intermittent pressure on formation of pressure ulcer in rabbit hind limbs].

    PubMed

    Liu, Jianghui; Wang, Weiping; Wang, Keke; Chen, Xilin; Li, Qiang; Dai, Qiangsheng; Wang, Yongqian; Ji, Zhongliang

    2009-08-01

    To compare the effect of two types of intermittent pressure on formation of pressure ulcer in rabbit hind limbs and to investigate the mechanism of gradually changed intermittent pressure produced by waves bed in the prevention of pressure ulcer. Gracilis (3 cm2) in both hind limbs of 12 adult Japanese white rabbits were randomly loaded with gradually changed intermittent pressure (50-160 mm Hg, 1 mm Hg = 0.133 kPa) and sustained pressure (100 mmHg) serving as the experimental group and the control group, respectively. The experiment was terminated after 4 cycles, and a single cycle included 2 hours of compression and 30 minutes of compression-release. Blood velocity of hind limbs and blood perfusion of wound were detected by bidirectional Doppler blood flow detector and laser Doppler perfusion imaging detection system before compression and at every 10 minutes in compression-release period of each cycle (0, 10, 20 and 30 minutes). After the termination, gross observation of the wound was conducted, pathomorphological changes of tissues from compressed area were observed by HE staining, and contents of NO, malondialdehyde (MDA), and superoxide dismutase (SOD) in muscle tissue were measured using colorimetry method. No significant difference was evident between two groups in terms of blood flow velocity before compression (P > 0.05); the blood flow velocity of two groups decreased significantly at 0 minute in every compression-release period of each cycle, and no significant differences were noted between two groups (P > 0.05); the blood flow velocity of the experimental group was higher than that of the control group at 10, 20 and 30 minutes (P < 0.05). No significant difference was noted between two groups in terms of wound blood perfusion before compression (P > 0.05); the wound blood perfusion of two groups decreased significantly at 0 minute in every compression-release period of each cycle, and no significant differences were noted between two groups (P > 0

  17. A ram-pressure threshold for star formation

    NASA Astrophysics Data System (ADS)

    Whitworth, A. P.

    2016-05-01

    In turbulent fragmentation, star formation occurs in condensations created by converging flows. The condensations must be sufficiently massive, dense and cool to be gravitationally unstable, so that they start to contract; and they must then radiate away thermal energy fast enough for self-gravity to remain dominant, so that they continue to contract. For the metallicities and temperatures in local star-forming clouds, this second requirement is only met robustly when the gas couples thermally to the dust, because this delivers the capacity to radiate across the full bandwidth of the continuum, rather than just in a few discrete spectral lines. This translates into a threshold for vigorous star formation, which can be written as a minimum ram pressure PCRIT ˜ 4 × 10-11 dyne. PCRIT is independent of temperature, and corresponds to flows with molecular hydrogen number density n_{{H_2.FLOW}} and velocity vFLOW satisfying n_{{H_2.FLOW}} v_{FLOW}^2≳ 800 cm^{-3} (km s^{-1})^2. This in turn corresponds to a minimum molecular hydrogen column density for vigorous star formation, N_{{H_2.CRIT}} ˜ 4 × 10^{21} cm^{-2} (ΣCRIT ˜ 100 M⊙ pc-2), and a minimum visual extinction AV, CRIT ˜ 9 mag. The characteristic diameter and line density for a star-forming filament when this threshold is just exceeded - a sweet spot for local star formation regions - are 2RFIL ˜ 0.1 pc and μFIL ˜ 13 M⊙ pc-2. The characteristic diameter and mass for a prestellar core condensing out of such a filament are 2RCORE ˜ 0.1 pc and MCORE ˜ 1 M⊙. We also show that fragmentation of a shock-compressed layer is likely to commence while the convergent flows creating the layer are still ongoing, and we stress that, under this circumstance, the phenomenology and characteristic scales for fragmentation of the layer are fundamentally different from those derived traditionally for pre-existing layers.

  18. Does benzydamine hydrochloride applied preemptively reduce sore throat due to laryngeal mask airway?

    PubMed

    Kati, Ismail; Tekin, Murat; Silay, Emin; Huseyinoglu, Urfettin A; Yildiz, Huseyin

    2004-09-01

    Sore throat is a common postoperative complaint. We investigated whether preemptive benzydamine hydrochloride (BH) treatment could prevent sore throat due to a laryngeal mask airway (LMA) cuff inflated with air. One-hundred ASA status I-II patients who underwent general anesthesia were randomly divided into two groups. In the first group, four puffs of BH were applied to the pharynx 30 min before the operation and 5 min before the induction of anesthesia. Distilled water with a similar bottle was applied with the same protocol in the second group. Anesthetic induction was provided with propofol and fentanyl. The pressure of the LMA cuff inflated with room air was measured after the first adjustment and after 30, 60, and 90 min of inflation in both groups. At the end of operation, the LMA was removed after the recovery of spontaneous breathing. After the operation, patients were asked about sore throat symptoms at the first, second, and fourth hours. There were no significant differences between groups for cuff pressures, cuff volumes, analgesic doses, or operation times. However, sore throat symptoms were significantly less severe for the BH group during both resting and swallowing. In conclusion, preemptive topical BH may decrease the incidence of sore throat due to LMA use.

  19. [Delayed post effort muscle soreness].

    PubMed

    Coudreuse, J M; Dupont, P; Nicol, C

    2004-08-01

    Muscle intolerance to exercise may result from different processes. Diagnosis involves confirming first the source of pain, then potential pathological myalgia. Delayed-onset muscle soreness (DOMS), commonly referred as tiredness, occurs frequently in sport. DOMS usually develops 12-48 h after intensive and/or unusual eccentric muscle action. Symptoms usually involve the quadriceps muscle group but may also affect the hamstring and triceps surae groups. The muscles are sensitive to palpation, contraction and passive stretch. Acidosis, muscle spasm and microlesions in both connective and muscle tissues may explain the symptoms. However, inflammation appears to be the most common explanation. Interestingly, there is strong evidence that the progression of the exercise-induced muscle injury proceeds no further in the absence of inflammation. Even though unpleasant, DOMS should not be considered as an indicator of muscle damage but, rather, a sign of the regenerative process, which is well known to contribute to the increased muscle mass. DOMS can be associated with decreased proprioception and range of motion, as well as maximal force and activation. DOMS disappears 2-10 days before complete functional recovery. This painless period is ripe for additional joint injuries. Similarly, if some treatments are well known to attenuate DOMS, none has been demonstrated to accelerate either structural or functional recovery. In terms of the role of the inflammatory process, these treatments might even delay overall recovery.

  20. Formation of xenon-nitrogen compounds at high pressure

    PubMed Central

    Howie, Ross T.; Turnbull, Robin; Binns, Jack; Frost, Mungo; Dalladay-Simpson, Philip; Gregoryanz, Eugene

    2016-01-01

    Molecular nitrogen exhibits one of the strongest known interatomic bonds, while xenon possesses a closed-shell electronic structure: a direct consequence of which renders both chemically unreactive. Through a series of optical spectroscopy and x-ray diffraction experiments, we demonstrate the formation of a novel van der Waals compound formed from binary Xe-N2 mixtures at pressures as low as 5 GPa. At 300 K and 5 GPa Xe(N2)2-I is synthesised, and if further compressed, undergoes a transition to a tetragonal Xe(N2)2-II phase at 14 GPa; this phase appears to be unexpectedly stable at least up to 180 GPa even after heating to above 2000 K. Raman spectroscopy measurements indicate a distinct weakening of the intramolecular bond of the nitrogen molecule above 60 GPa, while transmission measurements in the visible and mid-infrared regime suggest the metallisation of the compound at ~100 GPa. PMID:27748357

  1. SPECIFIC AND CROSS OVER EFFECTS OF MASSAGE FOR MUSCLE SORENESS: RANDOMIZED CONTROLLED TRIAL

    PubMed Central

    Sundstrup, Emil; Søndergaard, Stine D.; Behm, David; Brandt, Mikkel; Særvoll, Charlotte A.; Jakobsen, Markus D.; Andersen, Lars L.

    2014-01-01

    Purpose/Background: Muscle soreness can negatively interfere with the activities of daily living as well as sports performance. In the working environment, a common problem is muscle tenderness, soreness and pain, especially for workers frequently exposed to unilateral high repetitive movements tasks. The aim of the study is therefore to investigate the acute effect of massage applied using a simple device Thera‐band roller Massager on laboratory induced hamstring muscle soreness, and the potential cross over effect to the non‐massaged limb. Methods: 22 healthy untrained men (Mean age 34 +/− 7 years; mean height 181.7 +/− 6.9 cm; mean weight 80.6 +/− 6.4 kg; BMI: 24.5 +/− 1.3) with no prior history of knee, low back or neck injury or other adverse health issues were recruited. Participants visited the researchers on two separate occasions, separated by 48 hours, each time providing a soreness rating (modified visual analog scale 0‐10), and being tested for pressure pain threshold (PPT) and active range of motion (ROM) of the hamstring muscles. During the first visit, delayed onset muscular soreness of the hamstring muscles was induced by 10 x 10 repetitions of the stiff‐legged dead‐lift. On the second visit participants received either 1) 10 minutes of roller massage on one leg, while the contralateral leg served as a cross over control, or 2) Resting for 10 minutes with no massage at all. Measurement of soreness, PPT and ROM were taken immediately before and at 0, 10, 30 and 60 min. after treatment. Results: There was a significant group by time interaction for soreness (p < 0.0001) and PPT (p = 0.0007), with the massage group experiencing reduced soreness and increasing PPT compared with the control group. There was no group by time interaction for ROM (p = 0.18). At 10 min. post massage there was a significant reduction in soreness of the non‐massaged limb in the cross over control group compared to controls but this effect was lost 30

  2. Rare complication after VAC-therapy in the treatment of deep sore ulcers in a paraplegic patient.

    PubMed

    Citak, Mustafa; Backhaus, Manuel; Meindl, Renate; Muhr, Gert; Fehmer, Tobias

    2010-12-01

    The VAC-therapy is a safe, easy, and effective therapy for the management of chronic wounds. Known advantages of the VAC technique are the quicker wound healing by stimulating the blood flow, the formation of granulation tissue, angiogenesis, and cell proliferation. The use of negative pressure treatment can decrease the number of dressing changes and length of hospital stay. However, some related complications after and during VAC therapy have been described. We here describe a rare complication during the treatment of severe os ischium sore with VAC therapy, which has not been reported in the literature yet. We report about a 43-year-old paraplegic patient, referred to our clinic from a regional hospital where he had been admitted 2 months earlier, presenting with a necrotizing fasciitis after VAC therapy during the treatment of fourth grade os ischium sore. After operative debridement and long-term antibiotics with Ciprofloxacin soft tissue closure was performed using a myocutaneous tensor fascia lata flap. Temporary stabilization was achieved by a triangle external fixateur attached to the right femur and the pelvis. After 1 week the tapping point of the muscle flap could be covered with local skin mesh-graft from the right calf as a donor site. The patient was mobilized in a wheelchair and was discharged home 3 months after admission. The VAC technique is a safe, easy, and effective means in chronic wound care management. However, the described rare complication should be kept in mind. The clinical management of VAC therapy requires a distinct indication and close clinical monitoring by experienced medical professionals. The use of VAC therapy in fourth grade sores may have deleterious consequences for the patient.

  3. Perceived Muscle Soreness in Recreational Female Runners.

    PubMed

    Burnett, D; Smith, K; Smeltzer, C; Young, K; Burns, S

    The purpose of this study was to determine if rating of perceived exertion correlated with perceived muscle soreness during delayed onset muscle soreness (DOMS) in female runners. This study examined the pre and post running economy measures and perceived muscle soreness before and after a 30-min downhill run (DHR) at -15% grade and 70% of the subjects predetermined maximum oxygen uptake (VO2 peak). Six female recreational runners (mean age = 24.5) performed level running at 65%, 75%, and 85% of their VO2 peak prior to DHR (baseline economy runs), as well as, immediately following and 4 successive days after the DHR. Subjective response related to perceived muscle soreness increased significantly from a mean of 2 (pre DHR) to 62 (2 days post DHR) on a scale of 1-100. Creatine kinase levels and oxygen consumption increased post DHR compared to pre DHR. Rating of perceived exertion did not change between the economy runs performed prior to or at any point after the DHR. Perceived muscle soreness is a better tool than the RPE scale to monitor exercise intensity for recreational female runners during periods of DOMS and running economy is adversely affected by DOMS.

  4. Perceived Muscle Soreness in Recreational Female Runners

    PubMed Central

    Burnett, D.; Smith, K.; Smeltzer, C.; Young, K.; Burns, S.

    2010-01-01

    The purpose of this study was to determine if rating of perceived exertion correlated with perceived muscle soreness during delayed onset muscle soreness (DOMS) in female runners. This study examined the pre and post running economy measures and perceived muscle soreness before and after a 30-min downhill run (DHR) at −15% grade and 70% of the subjects predetermined maximum oxygen uptake (VO2 peak). Six female recreational runners (mean age = 24.5) performed level running at 65%, 75%, and 85% of their VO2 peak prior to DHR (baseline economy runs), as well as, immediately following and 4 successive days after the DHR. Results: Subjective response related to perceived muscle soreness increased significantly from a mean of 2 (pre DHR) to 62 (2 days post DHR) on a scale of 1–100. Creatine kinase levels and oxygen consumption increased post DHR compared to pre DHR. Rating of perceived exertion did not change between the economy runs performed prior to or at any point after the DHR. Conclusion: Perceived muscle soreness is a better tool than the RPE scale to monitor exercise intensity for recreational female runners during periods of DOMS and running economy is adversely affected by DOMS. PMID:27182336

  5. Risk factors for development of postoperative sore throat and hoarseness after endotracheal intubation in women: a secondary analysis.

    PubMed

    Jaensson, Maria; Gupta, Anil; Nilsson, Ulrica G

    2012-08-01

    Postoperative sore throat and hoarseness are common and disturbing complications following endotracheal intubation, and women are more frequently affected by these symptoms. This study explores risk factors associated with postoperative sore throat and hoarseness in women following intubation. In this prospective cross-sectional study, 97 patients undergoing elective ear, nose, and throat surgery or plastic surgery were included. Eight different variables were analyzed to detect possible associations for the development of postoperative sore throat or hoarseness. For data analysis, the chi2 test and the odds ratio were used. Three variables were found to be significant risk factors for postoperative sore throat: age greater than 60 years (P = .01), the use of a throat pack (P = .04), and endotracheal tube No. 7.0 (size 7 mm; P = .02). The only risk factor found to be significantly associated with developing hoarseness was an endotracheal cuff pressure below 20 centimeters of water (P = .04). Larger studies are needed to confirm these risk factors.

  6. The effect of intracuff alkalinized 2% lidocaine on emergence coughing, sore throat, and hoarseness in smokers.

    PubMed

    Navarro, Laís Helena Camacho; Lima, Rodrigo Moreira e; Aguiar, Andressa Simões; Braz, José Reinaldo Cerqueira; Carness, Jeffrey M; Módolo, Norma Sueli Pinheiro

    2012-01-01

    We evaluated whether endotracheal tube (ETT) intracuff alkalinized lidocaine was superior to saline in blunting emergence coughing, postoperative sore throat, and hoarseness in smokers. In our prospective, double-blind trial, we enrolled 50 smoking patients undergoing surgery under general anesthesia including nitrous oxide (N2O). Patients were randomly allocated to receive either ETT intracuff 2% lidocaine plus 8.4% sodium bicarbonate (L group), or ETT intracuff 0.9% saline (S group). The ETT cuff was inflated to achieve a cuff pressure that prevented air leak during positive pressure ventilation. Incidence of emergence coughing, sore throat, and hoarseness were analyzed. The volume of inflation solution, the intracuff pressure, the duration of anesthesia, the time elapsed to extubation after discontinuation of anesthesia, and the volume of the inflation solution and the air withdrawn from the ETT cuff were also recorded. Intracuff alkalinized 2% lidocaine was superior to saline in blunting emergence coughing (p < 0.001). The incidence of sore throat was significantly lower in the L group at the post-anesthesia care unit (PACU) (p = 0.02). However, at 24 hours after extubation, sore throat incidence was similar in both groups (p = 0.07). Incidence of hoarseness was similar in both groups. Intracuff pressure in the saline group increased with time while the intracuff pressure in the lidocaine group remained constant. The present study demonstrated that the intracuff alkalinized 2% lidocaine was superior to saline in decreasing the incidence of emergence coughing and sore throat during the postoperative period in smokers.

  7. HEADCO: a program for converting observed water levels and pressure measurements to formation pressure and standard hydraulic head

    SciTech Connect

    Spane, F.A. Jr.; Mercer, R.B.

    1985-10-01

    Static water-level and fluid pressure measurements are commonly converted in hydrologic studies to formation pressure and hydraulic head, which are used to determine groundwater flow characteristics of aquifer systems. While the direct use of field measurements is usually adequate for determining formation pressure and hydraulic head for shallow flow systems (i.e., <1000 ft), corrections and conversion parameters must be used to properly account for fluid-column density effects, which commonly occur with deep systems. This report presents a program, HEADCO, for converting static water-level and pressure measurements to formation pressure and standard hydraulic head. The HEADCO program corrects field measurements for the effects of fluid-density variation and selected external stresses. Factors that affect density of the fluid column, in which field measurements are made, include temperature, pressure, salinity, suspended solids, and multiphase conditions. External stresses examined in HEADCO include barometric and earth tide fluctuations, and gravitational acceleration variation. A program description and procedures for converting field measurements obtained using field test arrangements commonly employed in the Basalt Waste Isolation Project field program are provided in this report. The report includes user instructions and an illustrative test example. Results of a field example comparison are also provided. This comparison examines observed and HEADCO-calculated pressures for 30 pressure probes recently calibrated in a laboratory and tested under field conditions at borehole DC-8. The test case and field example comparisons indicate that HEADCO provides accurate estimates of formation pressure and standard hydraulic head that are well within the accuracy range of downhole pressure-measuring instrumentation. 44 refs., 14 figs., 8 tabs.

  8. Incidence of sore throat in children following use of flexible laryngeal mask airways - impact of an introducer device.

    PubMed

    William, Anthea; Chambers, Neil A; Erb, Thomas O; von Ungern-Sternberg, Britta S

    2010-09-01

    Insertion of a flexible laryngeal mask airway (FLMA) is more difficult and therefore might result in a higher risk for trauma to the upper airway. To facilitate the insertion of FLMA, the use of an introducer device (Portex Limited, Hythe, Kent, UK) was promoted. However, the impact of the use of this device on the occurrence of postoperative sore throat is unknown. Four hundred children (3-21 years) undergoing elective ambulatory surgery were consecutively included in this study. In 196 cases, the FLMA was inserted using an introducer device. The FLMA cuff was then inflated and the pressure adjusted to below 60 cmH(2)O (according to manufacturers guidelines) using a calibrated cuff manometer (Portex Limited). Three types of FLMA were available: FLMA classic, FLMA unique (both FLMA PacMed, Richmond, Victoria, Australia) and FLMA ProBreathe (Well Lead Medical Co Ltd., Hualong, Guangzhou, China). Prior to discharge, patients' pain was assessed using an age appropriate scale. Thirteen children (3.3%) developed sore throat, two (0.5%) sore neck and three (0.75%) sore jaw. Of those that developed sore throat, seven had a FLMA inserted with an introducer, six without an introducer. Using a laryngeal mask airways (LMA) with a polyvinyl chloride (PVC), surface was associated with a higher risk for sore throat compared with an LMA with a silicone surface (P = 0.0002). In this study with controlled low cuff pressures, the incidence of sore throat was low. The use of an introducer device did not affect the rate of sore throat.

  9. Acute effects of massage or active exercise in relieving muscle soreness: randomized controlled trial.

    PubMed

    Andersen, Lars L; Jay, Kenneth; Andersen, Christoffer H; Jakobsen, Markus D; Sundstrup, Emil; Topp, Robert; Behm, David G

    2013-12-01

    Massage is commonly believed to be the best modality for relieving muscle soreness. However, actively warming up the muscles with exercise may be an effective alternative. The purpose of this study was to compare the acute effect of massage with active exercise for relieving muscle soreness. Twenty healthy female volunteers (mean age 32 years) participated in this examiner-blind randomized controlled trial (ClinicalTrials.gov NCT01478451). The participants performed eccentric contractions for the upper trapezius muscle on a Biodex dynamometer. Delayed onset muscle soreness (DOMS) presented 48 hours later, at which the participants (a) received 10 minutes of massage of the trapezius muscle or (b) performed 10 minutes of active exercise (shoulder shrugs 10 × 10 reps) with increasing elastic resistance (Thera-Band). First, 1 treatment was randomly applied to 1 shoulder while the contralateral shoulder served as a passive control. Two hours later, the contralateral resting shoulder received the other treatment. The participants rated the intensity of soreness (scale 0-10), and a blinded examiner took measures of pressure pain threshold (PPT) of the upper trapezius immediately before treatment and 0, 10, 20, and 60 minutes after treatment 48 hours posteccentric exercise. Immediately before treatment, the intensity of soreness was 5.0 (SD 2.2) and PPT was 138 (SD 78) kPa. In response to treatment, a significant treatment by time interaction was found for the intensity of soreness (p < 0.001) and PPT (p < 0.05). Compared with control, both active exercise and massage significantly reduced the intensity of soreness and increased PPT (i.e., reduced pain sensitivity). For both types of treatment, the greatest effect on perceived soreness occurred immediately after treatment, whereas the effect on PPT peaked 20 minutes after treatment. In conclusion, active exercise using elastic resistance provides similar acute relief of muscle soreness as compared with that using massage

  10. Delayed Onset Muscle Soreness After Inspiratory Threshold Loading in Healthy Adults

    PubMed Central

    Mathur, Sunita; Sheel, A. William; Road, Jeremy D.; Reid, W. Darlene

    2010-01-01

    Purpose: Skeletal muscle damage occurs following high-intensity or unaccustomed exercise; however, it is difficult to monitor damage to the respiratory muscles, particularly in humans. The aim of this study was to use clinical measures to investigate the presence of skeletal muscle damage in the inspiratory muscles. Methods: Ten healthy subjects underwent 60 minutes of voluntary inspiratory threshold loading (ITL) at 70% of maximal inspiratory pressure. Maximal inspiratory and expiratory mouth pressures, delayed onset muscle soreness on a visual analogue scale and plasma creatine kinase were measured prior to ITL, and at repeated time points after ITL (4, 24 and 48 hours post-ITL). Results: Delayed onset muscle soreness was present in all subjects 24 hours following ITL (intensity = 22 ± 6 mm; significantly higher than baseline p = 0.02). Muscle soreness was reported primarily in the anterior neck region, and was correlated to the amount of work done by the inspiratory muscles during ITL (r = 0.72, p = 0.02). However, no significant change was observed in maximal inspiratory or expiratory pressures or creatine kinase. Conclusions: These findings suggest that an intense bout of ITL results in muscle soreness primarily in the accessory muscles of inspiration, however, may be insufficient to cause significant muscle damage in healthy adults. PMID:20467514

  11. A pressure-induced, magnetic transition in pyrrhotite: Implications for the formation pressure of meteorites and diamonds

    NASA Astrophysics Data System (ADS)

    Gilder, S. A.; Egli, R.; Hochleitner, R.; Roud, S. C.; Volk, M. W. R.; Le Goff, M.; de Wit, M.

    2012-04-01

    Meteorites and diamonds encounter high pressures during their formation or subsequent evolution. These materials sometimes contain magnetic inclusions of pyrrhotite. Because magnetic properties are sensitive to strain, pyrrhotite can potentially record the shock or formation pressures of its host. Moreover, pyrrhotite undergoes a pressure-induced phase transition between 1.6 and 6.2 GPa, but the magnetic signature of this transition is poorly known. Here we report room temperature magnetic measurements on multi- and single domain pyrrhotite under non-hydrostatic pressure up to 4.5 GPa. We find that the ratio of magnetic coercivity and remanence follows a logarithmic law with respect to pressure, which can potentially be used as a geobarometer. Due to the greater thermal expansion of pyrrhotite with respect to diamond, pyrrhotite inclusions in diamond experience a confining pressure at the Earth's surface. Applying our experimentally derived magnetic geobarometer to pyrrhotite-bearing diamonds from Botswana and the Central African Republic suggests the pressures of the pyrrhotite inclusions in the diamonds range from 1.3 to 2.1 GPa. These overpressures constrain the mantle source pressures from 5.4 to 9.5 GPa, depending on which bulk modulus and thermal expansion coefficients of the two phases are used. We are now trying to develop magnetic barometers on other magnetic phases to apply to meteorites, ultimately to constrain the minimum pressure in which the meteorite formed and, hence, information regarding the planetesmal's size, and/or depth, in which the meteorite was derived.

  12. Vibration Therapy in Management of Delayed Onset Muscle Soreness (DOMS)

    PubMed Central

    Imtiyaz, Shagufta

    2014-01-01

    Both athletic and nonathletic population when subjected to any unaccustomed or unfamiliar exercise will experience pain 24-72 hours postexercise. This exercise especially eccentric in nature caused primarily by muscle damage is known as delayed-onset muscle soreness (DOMS). This damage is characterized by muscular pain, decreased muscle force production, reduce range of motion and discomfort experienced. DOMS is due to microscopic muscle fiber tears. The presence of DOMS increases risk of injury. A reduced range of motion may lead to the incapability to efficiently absorb the shock that affect physical activity. Alterations to mechanical motion may increase strain placed on soft tissue structures. Reduced force output may signal compensatory recruitment of muscles, thus leading to unaccustomed stress on musculature. Differences in strength ratios may also cause excessive strain on unaccustomed musculature. A range of interventions aimed at decreasing symptoms of DOMS have been proposed. Although voluminous research has been done in this regard, there is little consensus among the practitioners regarding the most effective way of treating DOMS. Mechanical oscillatory motion provided by vibration therapy. Vibration could represent an effective exercise intervention for enhancing neuromuscular performance in athletes. Vibration has shown effectiveness in flexibility and explosive power. Vibration can apply either local area or whole body vibration. Vibration therapy improves muscular strength, power development, kinesthetic awareness, decreased muscle sore, increased range of motion, and increased blood flow under the skin. VT was effective for reduction of DOMS and regaining full ROM. Application of whole body vibration therapy in postexercise demonstrates less pressure pain threshold, muscle soreness along with less reduction maximal isometric and isokinetic voluntary strength and lower creatine kinase levels in the blood. PMID:25121012

  13. Vibration Therapy in Management of Delayed Onset Muscle Soreness (DOMS).

    PubMed

    Veqar, Zubia; Imtiyaz, Shagufta

    2014-06-01

    Both athletic and nonathletic population when subjected to any unaccustomed or unfamiliar exercise will experience pain 24-72 hours postexercise. This exercise especially eccentric in nature caused primarily by muscle damage is known as delayed-onset muscle soreness (DOMS). This damage is characterized by muscular pain, decreased muscle force production, reduce range of motion and discomfort experienced. DOMS is due to microscopic muscle fiber tears. The presence of DOMS increases risk of injury. A reduced range of motion may lead to the incapability to efficiently absorb the shock that affect physical activity. Alterations to mechanical motion may increase strain placed on soft tissue structures. Reduced force output may signal compensatory recruitment of muscles, thus leading to unaccustomed stress on musculature. Differences in strength ratios may also cause excessive strain on unaccustomed musculature. A range of interventions aimed at decreasing symptoms of DOMS have been proposed. Although voluminous research has been done in this regard, there is little consensus among the practitioners regarding the most effective way of treating DOMS. Mechanical oscillatory motion provided by vibration therapy. Vibration could represent an effective exercise intervention for enhancing neuromuscular performance in athletes. Vibration has shown effectiveness in flexibility and explosive power. Vibration can apply either local area or whole body vibration. Vibration therapy improves muscular strength, power development, kinesthetic awareness, decreased muscle sore, increased range of motion, and increased blood flow under the skin. VT was effective for reduction of DOMS and regaining full ROM. Application of whole body vibration therapy in postexercise demonstrates less pressure pain threshold, muscle soreness along with less reduction maximal isometric and isokinetic voluntary strength and lower creatine kinase levels in the blood.

  14. Fuel Structure and Pressure Effects on the Formation of Soot Particles in Diffusion Flames

    DTIC Science & Technology

    1990-05-01

    higher values of the pressure power dependence appear to be related to fuel structure effects , the direct nature of which remains to be understood...61102F 2308 A2 11. TITLE (Include Security Classification) "Fuel Structure and Pressure Effects on the Formation of Soot Particlesin Diffusion Flames...block number) Studies emphasizing the effects of fuel concentration and operating pressure on the formation of soot particles have been conducted in a

  15. Postneedling soreness after deep dry needling of a latent myofascial trigger point in the upper trapezius muscle: Characteristics, sex differences and associated factors.

    PubMed

    Martín-Pintado-Zugasti, Aitor; Rodríguez-Fernández, Ángel Luis; Fernandez-Carnero, Josue

    2016-04-27

    Postneedling soreness is considered the most frequent secondary effect associated to dry needling. A detailed description of postneedling soreness characteristics has not been previously reported. (1) to assess the intensity and duration of postneedling soreness and tenderness after deep dry needling of a trapezius latent myofascial trigger point (MTrP), (2) to evaluate the possible differences in postneedling soreness between sexes and (3) to analyze the influence on postneedling soreness of factors involved in the dry needling process. Sixty healthy subjects (30 men, 30 women) with latent MTrPs in the upper trapezius muscle received a dry needling intervention in the MTrP. Pain and pressure pain threshold (PPT) were assessed during a 72 hours follow-up period. Repeated measures analysis of covariance showed a significant effect for time in pain and in PPT. An interaction between sex and time in pain was obtained: women exhibited higher intensity in postneedling pain than men. The pain during needling and the number of needle insertions significantly correlated with postneedling soreness. Soreness and hyperalgesia are present in all subjects after dry needling of a latent MTrP in the upper trapezius muscle. Women exhibited higher intensity of postneedling soreness than men.

  16. Theoretical assessment of bonaccordite formation in pressurized water reactors

    DOE PAGES

    Rak, Zsolt; O'Brien, Chris; Shin, Dongwon; ...

    2016-03-04

    The free energy of formation of bonaccordite (Ni2FeBO5) as a function of temperature has been calculated using a technique that combines first principles calculations with experimental free energies of formation of aqueous species. The results suggest that bonaccordite formation from aqueous metal ions (Ni2+ andFe3+) and boric acid is thermodynamically favorable at elevated temperature and pH that have been predicted to exist at the CRUD-clad interface in deposits thicker than 60 μm.

  17. Theoretical assessment of bonaccordite formation in pressurized water reactors

    SciTech Connect

    Rak, Zsolt; O'Brien, Chris; Shin, Dongwon; Andersson, Anders David; Stanek, Christopher; Brenner, Donald

    2016-03-04

    The free energy of formation of bonaccordite (Ni2FeBO5) as a function of temperature has been calculated using a technique that combines first principles calculations with experimental free energies of formation of aqueous species. The results suggest that bonaccordite formation from aqueous metal ions (Ni2+ andFe3+) and boric acid is thermodynamically favorable at elevated temperature and pH that have been predicted to exist at the CRUD-clad interface in deposits thicker than 60 μm.

  18. Theoretical assessment of bonaccordite formation in pressurized water reactors

    NASA Astrophysics Data System (ADS)

    Rak, Zs; O'Brien, C. J.; Shin, D.; Andersson, A. D.; Stanek, C. R.; Brenner, D. W.

    2016-06-01

    The free energy of formation of bonaccordite (Ni2FeBO5) as a function of temperature has been calculated using a technique that combines first principles calculations with experimental free energies of formation of aqueous species. The results suggest that bonaccordite formation from aqueous metal ions (Ni2+ andFe3+) and boric acid is thermodynamically favorable at elevated temperature and pH that have been predicted to exist at the CRUD-clad interface in deposits thicker than 60 μm.

  19. Carbon Onions as Nanoscopic Pressure Cells for Diamond Formation

    NASA Astrophysics Data System (ADS)

    Banhart, Florian

    1997-03-01

    Concentric-shell carbon onions form under electron irradiation of different carbon precursors in an electron microscope. Carbon onions under irradiation at high temperature are in a state of high compression with a considerable decrease of the c-plane spacing towards the centre. Under prolonged irradiation at temperatures around 900 K the cores of the graphitic onions transform into diamond crystals (F. Banhart and P.M. Ajayan, Nature 382), 433 (1996). Hence, carbon onions can be thought of as nanoscopic pressure cells for the directly observable nucleation and growth of diamond from graphitic material. The diamond crystals grow under further irradiation until the whole graphitic particles have transformed to diamond. Apparently the conversion of the graphitic structure to diamond starts at high pressure and proceeds at decreasing, possibly even at zero pressure. The experiment is carried out in a transmission electron microscope which enables us to monitor this phase transformation in-situ on an atomic scale.

  20. Pressure-driven formation and stabilization of superconductive chromium hydrides

    PubMed Central

    Yu, Shuyin; Jia, Xiaojing; Frapper, Gilles; Li, Duan; Oganov, Artem R.; Zeng, Qingfeng; Zhang, Litong

    2015-01-01

    Chromium hydride is a prototype stoichiometric transition metal hydride. The phase diagram of Cr-H system at high pressures remains largely unexplored due to the challenges in dealing with the high activation barriers and complications in handing hydrogen under pressure. We have performed an extensive structural study on Cr-H system at pressure range 0 ∼ 300 GPa using an unbiased structure prediction method based on evolutionary algorithm. Upon compression, a number of hydrides are predicted to become stable in the excess hydrogen environment and these have compositions of Cr2Hn (n = 2–4, 6, 8, 16). Cr2H3, CrH2 and Cr2H5 structures are versions of the perfect anti-NiAs-type CrH with ordered tetrahedral interstitial sites filled by H atoms. CrH3 and CrH4 exhibit host-guest structural characteristics. In CrH8, H2 units are also identified. Our study unravels that CrH is a superconductor at atmospheric pressure with an estimated transition temperature (T c) of 10.6 K, and superconductivity in CrH3 is enhanced by the metallic hydrogen sublattice with T c of 37.1 K at 81 GPa, very similar to the extensively studied MgB2. PMID:26626579

  1. Pressure-driven formation and stabilization of superconductive chromium hydrides

    NASA Astrophysics Data System (ADS)

    Yu, Shuyin; Jia, Xiaojing; Frapper, Gilles; Li, Duan; Oganov, Artem R.; Zeng, Qingfeng; Zhang, Litong

    2015-12-01

    Chromium hydride is a prototype stoichiometric transition metal hydride. The phase diagram of Cr-H system at high pressures remains largely unexplored due to the challenges in dealing with the high activation barriers and complications in handing hydrogen under pressure. We have performed an extensive structural study on Cr-H system at pressure range 0 ˜ 300 GPa using an unbiased structure prediction method based on evolutionary algorithm. Upon compression, a number of hydrides are predicted to become stable in the excess hydrogen environment and these have compositions of Cr2Hn (n = 2-4, 6, 8, 16). Cr2H3, CrH2 and Cr2H5 structures are versions of the perfect anti-NiAs-type CrH with ordered tetrahedral interstitial sites filled by H atoms. CrH3 and CrH4 exhibit host-guest structural characteristics. In CrH8, H2 units are also identified. Our study unravels that CrH is a superconductor at atmospheric pressure with an estimated transition temperature (T c) of 10.6 K, and superconductivity in CrH3 is enhanced by the metallic hydrogen sublattice with T c of 37.1 K at 81 GPa, very similar to the extensively studied MgB2.

  2. Nimbus 3 alternating-pressure replacement mattress.

    PubMed

    Young, T

    Alternating-pressure surfaces have been shown to reduce the incidence of pressure sores compared with standard hospital mattresses and pressure-reducing (constant low-pressure) surfaces. Huntleigh Healthcare has recently introduced the Nimbus 3 to its range of alternating-pressure mattress replacement systems. This product has been developed according to new medical device regulations and is indicated for the treatment of patients with all grades of pressure sores and for prevention in patients who are at very high risk of developing pressure sores.

  3. Anatomy of a pressure-induced, ferromagnetic-to-paramagnetic transition in pyrrhotite: Implications for the formation pressure of diamonds

    NASA Astrophysics Data System (ADS)

    Gilder, Stuart A.; Egli, Ramon; Hochleitner, Rupert; Roud, Sophie C.; Volk, Michael W. R.; Le Goff, Maxime; de Wit, Maarten

    2011-10-01

    Meteorites and diamonds encounter high pressures during their formation or subsequent evolution. These materials commonly contain magnetic inclusions of pyrrhotite. Because magnetic properties are sensitive to strain, pyrrhotite can potentially record the shock or formation pressures of its host. Moreover, pyrrhotite undergoes a pressure-induced phase transition between 1.6 and 6.2 GPa, but the magnetic signature of this transition is poorly known. Here we report room temperature magnetic measurements on multidomain and single-domain pyrrhotite under nonhydrostatic pressure. Magnetic remanence in single-domain pyrrhotite is largely insensitive to pressure until 2 GPa, whereas the remanence of multidomain pyrrhotite increases 50% over that of initial conditions by 2 GPa, and then decreases until only 33% of the original remanence remains by 4.5 GPa. In contrast, magnetic coercivity increases with increasing pressure to 4.5 GPa. Below ˜1.5 GPa, multidomain pyrrhotite obeys Néel theory with a positive correlation between coercivity and remanence; above ˜1.5 GPa, it behaves single domain-like yet distinctly different from uncompressed single-domain pyrrhotite. The ratio of magnetic coercivity and remanence follows a logarithmic law with respect to pressure, which can potentially be used as a geobarometer. Owing to the greater thermal expansion of pyrrhotite with respect to diamond, pyrrhotite inclusions in diamonds experience a confining pressure at Earth's surface. Applying our experimentally derived magnetic geobarometer to pyrrhotite-bearing diamonds from Botswana and the Central African Republic suggests the pressures of the pyrrhotite inclusions in the diamonds range from 1.3 to 2.1 GPa. These overpressures constrain the mantle source pressures from 5.4 to 9.5 GPa, depending on which bulk modulus and thermal expansion coefficients of the two phases are used.

  4. Delayed onset muscle soreness: is massage effective?

    PubMed

    Nelson, Nicole

    2013-10-01

    Despite the widespread occurrence of delayed onset muscle soreness (DOMS), there is little consensus as to the exact cause or which treatments may be most effective at alleviating symptoms. Greater understanding of DOMS can give sports medicine and fitness professionals an opportunity to help prevent or speed recovery of this performance limiting condition. This article will review the DOMS literature, including the potential role of psychosocial factors and explore studies which involve massage therapy as a treatment modality. Articles from PubMed, MEDLINE, Google Scholar, and references from articles are included in this review. Search words and phrases included delayed onset muscle soreness, repeated bout effect, massage effectiveness, exercise induced muscle damage, and eccentric exercise.

  5. Managing Sore Throat: Theory Versus Practice

    PubMed Central

    Wong, Thomas; Tiessen, Esther

    1989-01-01

    The authors address the reliability of clinical impression in the management of sore throat. Five primary care family physicians in rural Ontario examined 222 patients with sore throats. The clinical impression of either Group A β-hemolytic streptococcal (GABHS) or non-GABHS pharyngitis was recorded and throat cultures were ordered in each case. The physicians predicted that 50% of the cultures would be positive for GABHS, whereas only 13.5% actually had positive results. The initial clinical diagnosis of “strep throat” was correct only one in five times. Without cultures, at least 112 patients would have been treated with antibiotics, 87 unnecessarily. The authors conclude that the clinical prediction of GABHS is inaccurate and can lead to unnecessary use of antibiotics. PMID:21249054

  6. Delayed onset muscle soreness: mechanisms and management.

    PubMed

    Cleak, M J; Eston, R G

    1992-08-01

    This review describes the phenomenon of delayed onset muscle soreness (DOMS), concentrating upon the types of muscle contraction most likely to produce DOMS and the theories underlying the physiological mechanisms of DOMS. Ways of attempting to reduce the effects of DOMS are also summarized, including the application of physical and pharmacological therapies to reduce the effects of DOMS and training for reduction or prevention of DOMS.

  7. A pressure-induced, magnetic transition in pyrrhotite: Implications for the formation pressure of meteorites and diamonds

    NASA Astrophysics Data System (ADS)

    Gilder, S. A.; Egli, R.; Hochleitner, R.; Roud, S. C.; Volk, M.; Le Goff, M.; de Wit, M.

    2010-12-01

    Meteorites and diamonds encounter high-pressures during their geologic histories. These materials commonly contain magnetic inclusions of pyrrhotite, and because magnetic properties are sensitive to strain, pyrrhotite can potentially record the shock or formation pressures of its host. Moreover, pyrrhotite undergoes a pressure-induced phase transition between 1.6 and 6.2 GPa, but the magnetic signature of this transition is poorly known. Here we report magnetic measurements performed at high-pressures on single and multi-domain pyrrhotite. A magnetic hysteresis model based on our observations suggests that multidomain pyrrhotite transforms into single domain-like material, and once in the single domain state, hysteresis loops become progressively squarer and then squatter with increasing pressure, until they ultimately collapse approaching the paramagnetic state at the transition. The ratio of the bulk magnetic coercive force to magnetic remanence for pure pyrrhotite is reversible with pressure and follows a logarithmic law as a function of pressure, which can be used as a magnetic barometer for natural systems.

  8. Effect of plasticity and atmospheric pressure on the formation of donut- and croissantlike buckles.

    PubMed

    Hamade, S; Durinck, J; Parry, G; Coupeau, C; Cimetière, A; Grilhé, J; Colin, J

    2015-01-01

    The formation of donut- and croissantlike buckles has been observed onto the free surface of gold thin films deposited on silicon substrates. Numerical simulations clearly evidence that the coupling effect between the atmospheric pressure acting on the free surface and the plastic folding of the ductile film is responsible for the circular blister destabilization and the formation of the donut- and croissantlike buckling patterns.

  9. Predicted formation of superconducting platinum-hydride crystals under pressure in the presence of molecular hydrogen.

    PubMed

    Kim, Duck Young; Scheicher, Ralph H; Pickard, Chris J; Needs, R J; Ahuja, R

    2011-09-09

    Noble metals adopt close-packed structures at ambient pressure and rarely undergo structural transformation at high pressures. Platinum (Pt) is normally considered to be unreactive and is therefore not expected to form hydrides under pressure. We predict that platinum hydride (PtH) has a lower enthalpy than its constituents solid Pt and molecular hydrogen at pressures above 21.5 GPa. PtH transforms to a hexagonal close-packed or face-centered cubic (fcc) structure between 70 and 80 GPa. Linear response calculations indicate that PtH is a superconductor at these pressures with a critical temperature of about 10-25 K. These findings help to shed light on recent observations of pressure-induced metallization and superconductivity in hydrogen-rich materials. We show that the formation of fcc noble metal hydrides under pressure is common and examine the possibility of superconductivity in these materials.

  10. Formation of an Apokampic Discharge Under Atmospheric Pressure Conditions

    NASA Astrophysics Data System (ADS)

    Skakun, V. S.; Panarin, V. A.; Pechenitsyn, D. S.; Sosnin, É. A.; Tarasenko, V. F.

    2016-09-01

    A new phenomenon is observed in a spark discharge developing under normal conditions in air in a discharge circuit with a capacitive decoupling. It consists in the current channel bending becoming a source of a 4-6 cm long plasma jet directed across the channel. The phenomenon is termed an apokampic discharge or an apokamp. Its emission spectrum contains the bands of electron-vibration transitions from the second positive group of molecular nitrogen. The conditions of formation of an apokamp are experimentally determined. A conclusion is drawn that in order construct a physical model of an apokamp, one has to take into account: 1) the presence of a local gas overheating in the site of the current channel bending, 2) the similarity of the current and voltage time dependences in the corona discharge and in the current channel (becoming a source of an apokamp), and 3) the length of the apokamp plasma jet.

  11. Prediction of subsidence: Relationship between lowering of formation pressure and subsidence due to fluid withdrawal

    SciTech Connect

    Serebryakov, V.A.; Chilingar, G.V.

    2000-06-01

    Abnormally low formation pressures develop in petroleum reservoirs during intensive oil and gas production or in aquifers as a result of water extraction. A simple method is presented for calculating (predicting) the amount of compaction (and resulting subsidence) from the pressure drop in formation due to production, i.e., the increase in the effective pressure p{sub e} (p{sub e} = p{sub t} {minus} p{sub p}, where p{sub t} is the total overburden pressure and p{sub p} is the fluid or pore pressure). This work is based on extensive data collected in Russia. For example, large petroliferous areas in Western Siberia became marshlands as a result of fluid withdrawal. One should remember that sophisticated methods, such as FSMT (direct measurement of rock compaction by wireline tools in situ) and GPS (measurement of surface subsidence by satellite microwave Doppler techniques), are not yet available in many areas of the world.

  12. Blood pressure changes in spontaneously hypertensive rats correlate with aortic prostacyclin formation.

    PubMed Central

    Fahr, A.; Förster, W.; Taube, C.

    1983-01-01

    1 The relationship between the blood pressure fall, induced by antihypertensive drugs or bleeding, and the formation of prostacyclin (PGI2)-like activity in the thoracic aorta of spontaneously hypertensive rats has been investigated. Inhibition of ADP-induced platelet aggregation was used to assess PGI2-like activity. 2 The decreases in blood pressure produced by clonidine, dihydralazine and prazosin were associated with increases of PGI2-like activity of 50-80%. The increase in PGI2-like activity correlated well with the blood pressure decrease, independently of the mechanism of the fall in blood pressure. PMID:6347301

  13. JET FORMATION FROM MASSIVE YOUNG STARS: MAGNETOHYDRODYNAMICS VERSUS RADIATION PRESSURE

    SciTech Connect

    Vaidya, Bhargav; Porth, Oliver; Fendt, Christian; Beuther, Henrik E-mail: fendt@mpia.de

    2011-11-20

    Observations indicate that outflows from massive young stars are more collimated during their early evolution compared to later stages. Our paper investigates various physical processes that impact the outflow dynamics, i.e., its acceleration and collimation. We perform axisymmetric magnetohydrodynamic (MHD) simulations particularly considering the radiation pressure exerted by the star and the disk. We have modified the PLUTO code to include radiative forces in the line-driving approximation. We launch the outflow from the innermost disk region (r < 50 AU) by magnetocentrifugal acceleration. In order to disentangle MHD effects from radiative forces, we start the simulation in pure MHD and later switch on the radiation force. We perform a parameter study considering different stellar masses (thus luminosity), magnetic flux, and line-force strength. For our reference simulation-assuming a 30 M{sub Sun} star-we find substantial de-collimation of 35% due to radiation forces. The opening angle increases from 20 Degree-Sign to 32 Degree-Sign for stellar masses from 20 M{sub Sun} to 60 M{sub Sun }. A small change in the line-force parameter {alpha} from 0.60 to 0.55 changes the opening angle by {approx}8 Degree-Sign . We find that it is mainly the stellar radiation that affects the jet dynamics. Unless the disk extends very close to the star, its force is too small to have much impact. Essentially, our parameter runs with different stellar masses can be understood as a proxy for the time evolution of the star-outflow system. Thus, we have shown that when the stellar mass (thus luminosity) increases with age, the outflows become less collimated.

  14. Jet Formation from Massive Young Stars: Magnetohydrodynamics versus Radiation Pressure

    NASA Astrophysics Data System (ADS)

    Vaidya, Bhargav; Fendt, Christian; Beuther, Henrik; Porth, Oliver

    2011-11-01

    Observations indicate that outflows from massive young stars are more collimated during their early evolution compared to later stages. Our paper investigates various physical processes that impact the outflow dynamics, i.e., its acceleration and collimation. We perform axisymmetric magnetohydrodynamic (MHD) simulations particularly considering the radiation pressure exerted by the star and the disk. We have modified the PLUTO code to include radiative forces in the line-driving approximation. We launch the outflow from the innermost disk region (r < 50 AU) by magnetocentrifugal acceleration. In order to disentangle MHD effects from radiative forces, we start the simulation in pure MHD and later switch on the radiation force. We perform a parameter study considering different stellar masses (thus luminosity), magnetic flux, and line-force strength. For our reference simulation—assuming a 30 M ⊙ star—we find substantial de-collimation of 35% due to radiation forces. The opening angle increases from 20° to 32° for stellar masses from 20 M ⊙ to 60 M ⊙. A small change in the line-force parameter α from 0.60 to 0.55 changes the opening angle by ~8°. We find that it is mainly the stellar radiation that affects the jet dynamics. Unless the disk extends very close to the star, its force is too small to have much impact. Essentially, our parameter runs with different stellar masses can be understood as a proxy for the time evolution of the star-outflow system. Thus, we have shown that when the stellar mass (thus luminosity) increases with age, the outflows become less collimated.

  15. The effects of ice massage on delayed muscle soreness.

    PubMed

    Yackzan, L; Adams, C; Francis, K T

    1984-01-01

    The following hypotheses were tested in the present study: (1) cryotherapy would reduce delayed muscle soreness (DMS) in eccentrically exercised muscles; (2) early cold treatment would reduce this soreness more than later postexercise treatment times; and (3) joint range of motion (ROM) would be inversely related to the subjective soreness ratings. Subjective sensations of muscular soreness and changes in elbow joint ROM were assessed in 30 subjects at 0, 24, 48, and 72 hours following eccentric-biased exercise in the elbow flexors. Cold treatments were applied immediately, 24 or 48 hours following a single exercise session. In response to the eccentric exercise, significant muscle soreness increases and elbow ROM decreases were observed in all exercised muscles from 24 to 48 hours postexercise. No differences in muscle soreness or elbow ROM changes were observed between treated and untreated arms except for one. Subjects treated at 24 hours postexercise reported greater soreness in their arms compared to untreated arms just prior to treatment (24 hour postexercise). The results do not support the efficacy of cold in reducing DMS. A negative correlation between muscle soreness and elbow ROM at 48 and 72 hours postexercise indicated that an increase in soreness was associated with a decrease in ROM.

  16. Reducing sore throat following laryngeal mask airway insertion: comparing lidocaine gel, saline, and washing mouth with the control group.

    PubMed

    Taghavi Gilani, Mehryar; Miri Soleimani, Iman; Razavi, Majid; Salehi, Maryam

    2015-01-01

    Laryngeal mask airway is still accompanied by complications such as sore throat. In this study, effects of three methods of reducing postoperative sore throat were compared with the control group. 240 patients with ASA I, II candidates for cataract surgery were randomly divided into four same groups. No supplementary method was used in the control group. In the second, third and fourth groups, lidocaine gel, washing cuff before insertion, and washing mouth before removing laryngeal mask airway were applied, respectively. Anesthesia induction was done with fentanyl, atracurium, and propofol and maintained with propofol infusion. The incidence of sore throat was evaluated during the recovery, 3-4h later and after 24h using verbal analog scale. The data were analyzed by t-test, analysis of variance and chi-square using SPSS V11.5. Age, gender, duration of surgery and cuff pressure were the same in all the four groups. Incidence of sore throat at recovery room was highest in the control group (43.3%) and lowest in the washing mouth group (25%). However, no significant statistical difference was observed between these four groups (recovery, p=0.30; discharge, p=0.31; examination, p=0.52). In this study, increased duration of operation had a significant relationship with the incidence of sore throat (p=0.041). Sore throat is a common postoperative problem, but no special method has been found completely efficient yet. In this study, cuff washing, lidocaine gel, and mouth washing before removing laryngeal mask airway were not helpful for sore throat. Copyright © 2013 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.

  17. [Reducing sore throat following laryngeal mask airway insertion: comparing lidocaine gel, saline, and washing mouth with the control group].

    PubMed

    Taghavi Gilani, Mehryar; Miri Soleimani, Iman; Razavi, Majid; Salehi, Maryam

    2015-01-01

    Laryngeal mask airway is still accompanied by complications such as sore throat. In this study, effects of three methods of reducing postoperative sore throat were compared with the control group. 240 patients with ASA I, II candidates for cataract surgery were randomly divided into four same groups. No supplementary method was used in the control group. In the second, third and fourth groups, lidocaine gel, washing cuff before insertion, and washing mouth before removing laryngeal mask airway were applied, respectively. Anesthesia induction was done with fentanyl, atracurium, and propofol and maintained with propofol infusion. The incidence of sore throat was evaluated during the recovery, 3-4h later and after 24h using verbal analog scale. The data were analyzed by t-test, analysis of variance and chi-square using SPSS V11.5. Age, gender, duration of surgery and cuff pressure were the same in all the four groups. Incidence of sore throat at recovery room was highest in the control group (43.3%) and lowest in the washing mouth group (25%). However, no significant statistical difference was observed between these four groups (recovery, p=0.30; discharge, p=0.31; examination, p=0.52). In this study, increased duration of operation had a significant relationship with the incidence of sore throat (p=0.041). Sore throat is a common postoperative problem, but no special method has been found completely efficient yet. In this study, cuff washing, lidocaine gel, and mouth washing before removing laryngeal mask airway were not helpful for sore throat. Copyright © 2013 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

  18. A New Mechanism for Mass Accretion Under Radiation Pressure in Massive Star Formation

    NASA Astrophysics Data System (ADS)

    Tanaka, Kei E. I.; Nakamoto, Taishi

    2010-05-01

    During the formation of a massive star, strong radiation pressure from the central star acts on the dust sublimation front and tends to halt the accretion flow. To overcome this strong radiation pressure, it has been considered that a strong ram pressure produced by a high-mass accretion rate of 10-3 M sun yr-1 or more is needed. We reinvestigated the necessary condition to overcome the radiation pressure and found a new mechanism for overcoming it. Accumulated mass in a stagnant flow near the dust sublimation front helps the mass accretion by its weight. This mechanism relaxes the condition for the massive star formation. We call this mechanism the "OMOSHI effect," where OMOSHI is an acronym for "One Mechanism for Overcoming Stellar High radiation pressure by weIght." Additionally, in Japanese, OMOSHI is a noun meaning a weight that is put on something to prevent it from moving. We investigate the generation of the OMOSHI effect using local one-dimensional radiation hydrodynamics simulations. The radiation pressure and the gravitational force are connected through the gas pressure, and to sum up, the radiation pressure is balanced or overcome by the gravitational force. We also discuss the global structure and temporal variation of the accretion flow.

  19. Influence of ambient pressure on the hole formation process in ultrashort pulse laser deep drilling

    NASA Astrophysics Data System (ADS)

    Döring, Sven; Richter, Sören; Ullsperger, Tobias; Tünnermann, Andreas; Nolte, Stefan

    2013-03-01

    We investigate the influence of the ambient pressure on the hole formation process during percussion drilling of silicon by applying an in-situ imaging technique. In this study the pressure is varied from atmospheric conditions down to medium vacuum of 10 !bar. Drilling was performed using an ultrashort pulse system providing 8 ps pulses with up to 125 μJ at 1030 nm. At this wavelength, the ablation behavior of silicon is comparable to metals. At the beginning of the drilling process, we observe an increased drilling efficiency by 40% already for a moderate pressure decrease to 100 mbar. The formation of an ideally shaped hole lasts for approximately 200 pulses instead of only 100 as for atmospheric conditions and therefore leads to 3 times the depth at this point. The effect can be enhanced by increasing the pulse energy, but not by decreasing pressure further. However, the number of pulses till the end of the drilling process is extended by decreasing the pressure further. For a low ambient pressure of 10 μbar, this is accompanied by an increase of the maximum achievable depth of more than 100%. Simultaneously the hole shape changes from a few ends and bulges at atmospheric conditions to numerous branches over the complete lower part of the hole at low pressure. This drilling behavior can be attributed to a better removal of ablated particles from the hole capillary with decreasing pressure, which leads to lower scattering losses for the pulse propagation inside the hole.

  20. A NEW MECHANISM FOR MASS ACCRETION UNDER RADIATION PRESSURE IN MASSIVE STAR FORMATION

    SciTech Connect

    Tanaka, Kei E. I.; Nakamoto, Taishi

    2010-05-01

    During the formation of a massive star, strong radiation pressure from the central star acts on the dust sublimation front and tends to halt the accretion flow. To overcome this strong radiation pressure, it has been considered that a strong ram pressure produced by a high-mass accretion rate of 10{sup -3} M{sub sun} yr{sup -1} or more is needed. We reinvestigated the necessary condition to overcome the radiation pressure and found a new mechanism for overcoming it. Accumulated mass in a stagnant flow near the dust sublimation front helps the mass accretion by its weight. This mechanism relaxes the condition for the massive star formation. We call this mechanism the 'OMOSHI effect', where OMOSHI is an acronym for 'One Mechanism for Overcoming Stellar High radiation pressure by weIght'. Additionally, in Japanese, OMOSHI is a noun meaning a weight that is put on something to prevent it from moving. We investigate the generation of the OMOSHI effect using local one-dimensional radiation hydrodynamics simulations. The radiation pressure and the gravitational force are connected through the gas pressure, and to sum up, the radiation pressure is balanced or overcome by the gravitational force. We also discuss the global structure and temporal variation of the accretion flow.

  1. Self-regulating galaxy formation. I - H II disk and Lyman-alpha pressure

    NASA Technical Reports Server (NTRS)

    Cox, D. P.

    1985-01-01

    The nascent interstellar medium and star formation model are incorporated into a scenario for the formation epoch of spiral galaxies. The structure, star formation time scale, and luminosity of a self-gravitating isothermal disk are evaluated as functions of the disk surface density. The importance of radiation pressure, particularly that of Lyman-alpha, in maintaining an inflated disk and halting infall is discussed. The Lyman-alpha pressure also supports a considerable halo of material in the vicinity of the disk. A first-order infall scenario and the time-dependent properties of the system it constructs are presented. Disk properties are evaluated at the epoch at which further material is supportable against infall by Lyman-alpha pressure. The two-dimensional family of disk galaxies whose scales and surface density are expressible in terms of fundamental constants and which arise from the three parameter sets of perturbations in the Hubble flow are determined.

  2. Sore Throat - Multiple Languages: MedlinePlus

    MedlinePlus

    ... gov/languages/sorethroat.html Other topics A-Z A B C D E F G H I J K L M N O P Q R S T U V W XYZ List of All Topics All Sore Throat - Multiple Languages To use the sharing features on this page, please enable JavaScript. Chinese - Traditional (繁體中文) French (français) Hindi (हिन्दी) Japanese (日本語) Korean (한국어) ...

  3. Sore throat in primary care project: a clinical score to diagnose viral sore throat.

    PubMed

    Mistik, Selcuk; Gokahmetoglu, Selma; Balci, Elcin; Onuk, Fahri A

    2015-06-01

    Viral agents cause the majority of sore throats. However, there is not currently a score to diagnose viral sore throat. The aims of this study were (i) to find the rate of bacterial and viral causes, (ii) to show the seasonal variations and (iii) to form a new scoring system to diagnose viral sore throat. A throat culture for group A beta haemolytic streptococci (GABHS) and a nasopharyngeal swab to detect 16 respiratory viruses were obtained from each patient. Over a period of 52 weeks, a total of 624 throat cultures and polymerase chain reaction analyses were performed. Logistic regression analysis was performed to find the clinical score. Viral infection was found in 277 patients (44.3%), and GABHS infection was found in 116 patients (18.5%). An infectious cause was found in 356 patients (57.1%). Rhinovirus was the most commonly detected infectious agent overall (highest in November, 34.5%), and the highest GABHS rate was in November (32.7%). Analysis of data provided a scoring system, called the Mistik Score, to diagnose viral sore throat. The predictive model for positive viral analysis included the following variables: absence of headache, stuffy nose, sneezing, temperature of ≥37.5°C on physical examination, and the absence of tonsillar exudate and/or swelling. The probability of a positive viral analysis for a score of 5 was 82.1%. The Mistik Score may be useful to diagnose viral sore throat. We suggest its use either alone or in combination with the Modified Centor Score. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  4. Kinetics of the formation of radicals in meat during high pressure processing.

    PubMed

    Bolumar, Tomas; Skibsted, Leif H; Orlien, Vibeke

    2012-10-15

    The kinetics of the formation of radicals in meat by high pressure processing (HPP) has been described for the first time. A threshold for the radicals to form at 400 MPa at 25 °C and at 500 MPa at 5 °C has been found. Above this threshold, an increased formation of radicals was observed with increasing pressure (400-800 MPa), temperature (5-40 °C) and time (0-60 min). The volume of activation (ΔV(#)) was found to have the value -17 ml mol(-1). The energy of activation (E(a)) was calculated to be 25-29 kJ mol(-1) within the pressure range (500-800 MPa) indicating high independence on the temperature at high pressures whereas the reaction was strongly dependent at atmospheric pressure (E(a)=181 kJ mol(-1)). According to the effect of the processing conditions on the reaction rate, three groups of increasing order of radical formation were established: (1) 55 °C at 0.1 MPa, (2) 500 and 600 MPa at 25 °C and 65 °C at 0.1 MPa, and (3) 700 MPa at 25 °C and 75 °C at 0.1 MPa. The implication of the formation of radicals as initiators of lipid oxidation under HPP is discussed. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. High pressure rheometer for in situ formation and characterization of methane hydrates

    NASA Astrophysics Data System (ADS)

    Webb, Eric B.; Rensing, Patrick J.; Koh, Carolyn A.; Dendy Sloan, E.; Sum, Amadeu K.; Liberatore, Matthew W.

    2012-01-01

    We present a novel setup for a high pressure rheometer operating with concentric cylinders geometry for in situ studies of hydrate formation and rheological characterization. The apparatus uses an external high pressure mixing cell to saturate water-in-oil emulsions with methane gas. The capability of mixing combined with a true rheometer design make this apparatus unique in terms of setup and sample formation. We have used the apparatus to form gas hydrates in situ from water-in-oil emulsions and characterize suspension rheological properties such as yield stress and shear-thinning behavior.

  6. Pore pressure prediction and well bore stability analysis in Lower Paleozoic shale formation, N Poland

    NASA Astrophysics Data System (ADS)

    Słota-Valim, Małgorzata

    2017-04-01

    Pore pressure and wellbore stability sometimes pose a serious challenge while drilling, especially through rock formations of reduced strength or through intervals where abnormally high pore pressure was formed. Lack of prediction of pore pressure and lack of wellbore stability analysis introduce an element of uncertainty in selection of drilling fluid density. Too low density of drilling fluid can lead to uncontrolled flow of the reservoir fluid to the wellbore (kicks), washouts and occurrence of cavern like structures called breakouts. On the other hand too high density can lead to formation fracturing and further fluid loss. Therefore wellbore stability loss frequently prolongs the operating time, rising the costs of the drilling and in severe cases may end up well abandons loss. The above mentioned complications can be avoided or greatly reduced by reliable analysis of drilling conditions with the aspects to geomechanical characteristics of drilled rock formations. This study presents the results of analysis of pore pressure performed with the use of commonly used in oil industry methods. The analysis of pore pressure was carried out in almost entire profile of four boreholes drilled through lower Paleozoic shales, deposited in the southern part of the Baltic Basin. In addition wellbore stability analysis was performed in the well with most complete geomechanical input data base. Obtained results helped identifying intervals with elevated pore pressure could pose a risk during drilling operation. Elaborated 1D geomechanical model provides safe mud weight window helping to reduce the instabilities risk and constitute a great tool for geomechanical model validation.

  7. Control of tetrahedron satellite formation flying in the geosynchronous orbit using solar radiation pressure

    NASA Astrophysics Data System (ADS)

    Hou, Yong-Gang; Zhang, Ming-Jiang; Zhao, Chang-Yin; Sun, Rong-Yu

    2016-04-01

    In this paper, the control of tetrahedron satellite formation flying in the geosynchronous orbit (GEO) using solar radiation pressure is investigated. The long term disturbing effect of the main zonal and tesseral harmonics J2 and J_{22} of the geopotential are eliminated by adjusting the initial orbital elements, and a tetrahedron satellite formation flying in the GEO is designed. Then a control system using solar radiation pressure is further proposed to maintain the tetrahedron satellite formation, in which a sliding mode control (SMC) is developed to determine the control force. The control force is acquired from the solar sails equipped on the satellites, and the final control law and strategy using solar radiation pressure are presented. Moreover, three kinds of numerical simulations are especially given to verify the validity of the control system using solar radiation. It shows that Laplace precession of the GEO satellite can be avoided effectively, and the in-plane and out-of-plane errors of the formation can be eliminated easily. And hence the control of tetrahedron satellite formation flying in the GEO using solar radiation pressure is proved to be feasible.

  8. Does Postexercise Static Stretching Alleviate Delayed Muscle Soreness?

    ERIC Educational Resources Information Center

    Buroker, Katherine C.; Schwane, James A.

    1989-01-01

    Because many experts recommend stretching after exercise to relieve muscle soreness, 23 subjects performed a 30-minute step test to induce delayed muscle soreness. There was neither temporary relief of pain immediately after stretching nor a reduction in pain during the 3-day postexercise period. (Author/SM)

  9. Laser homeostatics on delayed onset muscle soreness

    NASA Astrophysics Data System (ADS)

    Liu, T. C. Y.; Fu, D. R.; Liu, X. G.; Tian, Z. X.

    2011-01-01

    Delayed onset muscle soreness (DOMS) and its photobiomodulation were reviewed from the viewpoint of function-specific homeostasis (FSH) in this paper. FSH is a negative-feedback response of a biosystem to maintain the function-specific fluctuations inside the biosystem so that the function is perfectly performed. A stressor may destroy a FSH. A stress is a response of a biosystem to a stressor and may also be in stress-specific homeostasis (StSH). A low level light (LLL) is so defined that it has no effects on a function in its FSH or a stress in its StSH, but it modulate a function far from its FSH or a stress far from its StSH. For DOMS recovery, protein metabolism in the Z-line streaming muscular cell is the essential process, but the inflammation, pain and soreness are non-essential processes. For many DOMS phenomena, protein metabolism in the Z-line streaming muscular cell is in protein metabolism-specific homeostasis (PmSH) so that there are no effects of LLL although the inflammation can be inhibited and the pain can be relieved. An athlete or animal in the dysfunctional conditions such as blood flow restriction and exercise exhaustion is far from PmSH and the protein metabolism can be improved with LLL.

  10. Glass formation and cluster evolution in the rapidly solidified monatomic metallic liquid Ta under high pressure

    NASA Astrophysics Data System (ADS)

    Jiang, Dejun; Wen, Dadong; Tian, Zean; Liu, Rangsu

    2016-12-01

    Molecular dynamics (MD) simulations have been performed to examine the glass formation and cluster evolution during the rapid solidification of monatomic metallic liquid Ta under high pressure. The atomic structures in the systems are characterized by the radical distribution function (RDF), Honeycutt-Anderson (H-A) bond-type index method and cluster-type index method (CTIM). It is observed that the defective icosahedra play the critical role in the formation of Ta monatomic metallic glasses (MGs) rather than (12 0 12 0) perfect icosahedra, which have been identified as the basic local atomic units in many multi-component MGs. With the increase of pressure P, the fraction of icosahedral type clusters decreases remarkably in Ta MGs, while the fraction of bcc type clusters rises evidently. The evolution of vitrification degree (DSRO or DMRO) of the rapidly cooled metal Ta system further reveals that a higher pressure P is disadvantageous to the formation of Ta monatomic MGs. The weaker glass forming ability (GFA) of liquid metal Ta obtained under higher pressure P can be contributed to the decrease of DSRO or DMRO which is induced by increasing high pressure P to some extent.

  11. Tracking CO2 Plume in Deep Saline Formations Utilizing a Time-lapse Pressure Tomography Approach

    NASA Astrophysics Data System (ADS)

    Hu, L.; Bayer, P.; Brauchler, R.

    2015-12-01

    CO2 storage in deep saline formations is considered as an attractive option to cut down greenhouse gas emissions. Among the major challenges is the development of efficient technologies for controlling and monitoring the evolution of CO2 plumes during and after injection in the underground. As an alternative to the most commonly used geophysical approaches for subsurface characterization, we propose a pressure-based tomographical approach to track CO2 plume history. By taking into account the direct relationship between saturation and flow properties, pressure tomography has the potential not only to detect a plume but also to estimate the saturation of CO2. The experimental set-up of pressure tomography involves injection of brine or CO2 at variable depths (sources). We use a time-lapse approach, considering first the CO2-free formation, and then the multi-phase CO2-brine system. By applying a rapid eikonal-based inversion technique, pressure fluctuations at observation locations (receivers) are utilized to reconstruct the spatial distribution of the apparent single-phase and mixed-phase diffusivity. Evolution of the plume shape is then delineated by comparison of diffusivity tomograms derived from different times. Finally, an integrated value of CO2 saturation within the plume is obtained by means of a single-phase proxy. Applicability of this novel approach is evaluated in different virtual formations. The time-lapse pressure tomographic investigation revealed that knowledge about the spatial heterogeneity of permeability has a remarkable impact on proper characterization of plume shape.

  12. Experimental modeling of pressurized subglacial water flow: Implications for tunnel valley formation

    NASA Astrophysics Data System (ADS)

    Lelandais, Thomas; Mourgues, Régis; Ravier, Édouard; Pochat, Stéphane; Strzerzynski, Pierre; Bourgeois, Olivier

    2016-11-01

    Tunnel valleys are elongated hollows commonly found in formerly glaciated areas and interpreted as resulting from subglacial meltwater erosion beneath ice sheets. Over the past two decades, the number of studies of terrestrial tunnel valleys has continuously increased, and their existence has been hypothesized also on Mars, but their formation mechanisms remain poorly understood. We introduce here an innovative experimental approach to examine erosion by circulation of pressurized meltwater within the substratum and at the ice/substratum interface. We used a permeable substratum (sand) partially covered by a viscous, impermeable, and transparent cap (silicon putty), below which we applied a central injection of pure water. Low water pressures led to groundwater circulation in the substratum only, while water pressures exceeding a threshold that is larger than the sum of the glaciostatic and lithostatic pressures led to additional water circulation and formation of drainage landforms at the cap/substratum interface. The formation of these drainage landforms was monitored through time, and their shapes were analyzed from digital elevation models obtained by stereo-photogrammetry. The experimental landforms include valleys that are similar to natural tunnel valleys in their spatial organization and in a number of diagnostic morphological criteria, such as undulating longitudinal profiles and "tunnel" shapes. These results are consistent with the hypothesis that overpressurized subglacial water circulation controls the formation of tunnel valleys.

  13. OMOSHI Effect: A New Mechanism for Mass Accretion under the Radiation Pressure in Massive Star Formation

    NASA Astrophysics Data System (ADS)

    Tanaka, Kei; Nakamoto, Taishi

    2009-08-01

    In a massive-star formation process, a high-mass accretion rate is considered to be needed to overcome the strong radiation pressure at the dust sublimation front. We examined the accretion structure near the dust sublimation front and found a new mechanism to overcome this radiation pressure. The weight of the accumulated mass in a stagnant flow near the dust sublimation front helps with the mass accretion. We call this mechanism the ``OMOSHI effect,'' where OMOSHI is an acronym for ``One Mechanism for Overcoming Stellar High radiation pressure by weight.'' OMOSHI is also a Japanese noun meaning a weight that is put on something to prevent it from moving. This mechanism relaxes the condition for the massive star formation.

  14. Rogue wave formation under the action of quasi-stationary pressure

    NASA Astrophysics Data System (ADS)

    Abrashkin, A. A.; Oshmarina, O. E.

    2016-05-01

    The process of rogue wave formation on deep water is considered. A wave of extreme amplitude is born against the background of uniform waves (Gerstner waves) under the action of external pressure on free surface. The pressure distribution has a form of a quasi-stationary "pit". The fluid motion is supposed to be a vortex one and is described by an exact solution of equations of 2D hydrodynamics for an ideal fluid in Lagrangian coordinates. Liquid particles are moving around circumferences of different radii in the absence of drift flow. Values of amplitude and wave steepness optimal for rogue wave formation are found numerically. The influence of vorticity distribution and pressure drop on parameters of the fluid is investigated.

  15. Pressure-dependent formation of i-motif and G-quadruplex DNA structures.

    PubMed

    Takahashi, S; Sugimoto, N

    2015-12-14

    Pressure is an important physical stimulus that can influence the fate of cells by causing structural changes in biomolecules such as DNA. We investigated the effect of high pressure on the folding of duplex, DNA i-motif, and G-quadruplex (G4) structures; the non-canonical structures may be modulators of expression of genes involved in cancer progression. The i-motif structure was stabilized by high pressure, whereas the G4 structure was destabilized. The melting temperature of an intramolecular i-motif formed by 5'-dCGG(CCT)10CGG-3' increased from 38.8 °C at atmospheric pressure to 61.5 °C at 400 MPa. This effect was also observed in the presence of 40 wt% ethylene glycol, a crowding agent. In the presence of 40 wt% ethylene glycol, the G4 structure was less destabilized than in the absence of the crowding agent. P-T stability diagrams of duplex DNA with a telomeric sequence indicated that the duplex is more stable than G4 and i-motif structures under low pressure, but the i-motif dominates the structural composition under high pressure. Under crowding conditions, the P-T diagrams indicated that the duplex does not form under high pressure, and i-motif and G4 structures dominate. Our findings imply that temperature regulates the formation of the duplex structure, whereas pressure triggers the formation of non-canonical DNA structures like i-motif and G4. These results suggest that pressure impacts the function of nucleic acids by stabilizing non-canonical structures; this may be relevant to deep sea organisms and during evolution under prebiotic conditions.

  16. Feasibility study of a novel approach to sore prevention in patients with spinal cord lesions: the computerized dynamic control Matrix 200 system.

    PubMed

    Catz, A; Philo, O; Gilad, N; Barel, O; Geva, T

    1999-02-01

    To evaluate the feasibility of a computerized mattress system based on a novel concept in sore prevention: continuous monitoring and adjustment of the interface pressure in small segments of contact between the skin and the supporting surface. A preliminary observational study. The Spinal Department, Loewenstein Rehabilitation Hospital, Raanana, Israel. Twelve patients with spinal cord lesions. Patients were examined for signs of impending sores after lying on the mattress for up to 4 successive hours. The pressure within each of the mattress's air cells was continuously measured and adjusted. No evidence of redness or excessive perspiration was found in any of the areas considered to be high risk for bed sores. Maximal interface pressure was 22-30 mm Hg in most of the examinations. Most of the patients felt comfortable on the mattress and the staff adapted easily to its operation. The system is apparently safe, and at least as efficient as other existing means for preventing sores. In addition, it may allow for increased intervals between bed positionings. We conclude that this approach of pressure control has the potential to improve bed sore prevention in a rehabilitation hospital setting.

  17. Scintigraphy can be used to compare delivery of sore throat formulations.

    PubMed

    Limb, M; Connor, A; Pickford, M; Church, A; Mamman, R; Reader, S; Shephard, A; Aspley, S; Goulder, M A

    2009-04-01

    Sore throat (pharyngitis) is commonly treated with over-the-counter lozenges, tablets, sprays and gargles. While the efficacy of the active ingredients has been examined, less is known about the comparative efficacy of the different delivery formats. A pilot study was initially performed, followed by an open-label, four-way crossover study in healthy volunteers to quantitatively assess the delivery efficacy of a lozenge, tablet, spray and gargle, using technetium-99m and scintigraphy as a marker of deposition and clearance of the active ingredients. Initial deposition in the mouth and throat combined was significantly greater for the solid dose forms (lozenge and tablet) than for the spray or gargle. Rates of clearance were initially similar for the tablet and lozenge with low levels of radioactivity present at up to 2 h. At 10 and 20 min, significantly more of the dose remained for the lozenge than for the tablet. The mouth appeared to act as a reservoir for continued clearance to the throat. Scintigraphy is an effective means of quantifying the delivery efficiency, and hence availability, of sore throat medications. The results presented here suggest that both lozenges and tablets offer considerable advantages over sprays or gargles, both in terms of proportion of the dose delivered to the mouth and throat, combined, and clearance from these regions. These delivery formats provide fast, effective and prolonged delivery of active ingredients, highlighting their potential benefits for sore throat medication.

  18. Effects of hydrogen partial pressure on autotrophic growth and product formation of Acetobacterium woodii.

    PubMed

    Kantzow, Christina; Weuster-Botz, Dirk

    2016-08-01

    Low aqueous solubility of the gases for autotrophic fermentations (e.g., hydrogen gas) results in low productivities in bioreactors. A frequently suggested approach to overcome mass transfer limitation is to increase the solubility of the limiting gas in the reaction medium by increasing the partial pressure in the gas phase. An increased inlet hydrogen partial pressure of up to 2.1 bar (total pressure of 3.5 bar) was applied for the autotrophic conversion of hydrogen and carbon dioxide with Acetobacterium woodii in a batch-operated stirred-tank bioreactor with continuous gas supply. Compared to the autotrophic batch process with an inlet hydrogen partial pressure of 0.4 bar (total pressure of 1.0 bar) the final acetate concentration after 3.1 days was reduced to 50 % (29.2 g L(-1) compared to 59.3 g L(-1)), but the final formate concentration was increased by a factor of 18 (7.3 g L(-1) compared to 0.4 g L(-1)). Applying recombinant A. woodii strains overexpressing either genes for enzymes in the methyl branch of the Wood-Ljungdahl pathway or the genes phosphotransacetylase and acetate kinase at an inlet hydrogen partial pressure of 1.4 bar reduced the final formate concentration by up to 40 % and increased the final dry cell mass and acetate concentrations compared to the wild type strain. Solely the overexpression of the two genes for ATP regeneration at the end of the Wood-Ljungdahl pathway resulted in an initial switch off of formate production at increased hydrogen partial pressure until the maximum of the hydrogen uptake rate was reached.

  19. Effect of Processing Pressure on Isolated Pore Formation during Controlled Directional Solidification in Small Channels

    NASA Technical Reports Server (NTRS)

    Cox, Matthew C.; Anilkumar, Amrutur V.; Grugel, RIchard N.; Lee, Chun P.

    2008-01-01

    Directional solidification experiments were performed, using succinonitrile saturated with nitrogen gas, to examine the effects of in-situ processing pressure changes on the formation growth, and evolution of an isolated, cylindrical gaseous pore. A novel solidification facility, capable of processing thin cylindrical samples (I.D. < 1.0 mm), under controlled pressure conditions, was used for the experiments. A new experimental method for growing the isolated pore from a seed bubble is introduced. The experimental results indicate that an in-situ processing pressure change will result in either a transient change in pore diameter or a complete termination of pore growth, indicating that pressure changes can be used as a control parameter to terminate bubble growth. A simple analytical model has been introduced to explain the experimental observations.

  20. Silicon nitride-aluminum oxide solid solution (SiAION) formation and densification by pressure sintering

    NASA Technical Reports Server (NTRS)

    Yeh, H. C.; Sanders, W. A.; Fiyalko, J. L.

    1975-01-01

    Stirred-ball-mill-blended Si3N4 and Al2O3 powders were pressure sintered in order to investigate the mechanism of solid solution formation and densification in the Si3N4-Al2O3 system. Powder blends with Si3N4:Al2O3 mole ratios of 4:1, 3:2, and 2:3 were pressure sintered at 27.6-MN/sq m pressure at temperatures to 17000 C (3090 F). The compaction behavior of the powder blends during pressure sintering was determined by observing the density of the powder compact as a function of temperature and time starting from room temperature. This information, combined with the results of X-ray diffraction and metallographic analyses regarding solutioning and phase transformation phenomena in the Si3N4-Al2O3 system, was used to describe the densification behavior.

  1. Pregame Sore Throat, Postgame Intensive Care Unit.

    PubMed

    Stork, Natalie C; Smoot, M Kyle

    2016-05-01

    A collegiate football athlete presented, on game day, with an acute onset of sore throat. He was afebrile, speaking in full sentences, without signs of respiratory distress. His examination was negative for lymphadenopathy or tonsillar enlargement or exudate. Twelve hours after initial presentation, he developed acute epiglottitis. He underwent urgent fiberoptic intubation and was empirically treated with broad-spectrum antibiotics and corticosteroids. Currently, there are no published reports of acute epiglottitis in athletes. Consequently, there is no evidence to guide return to play decisions. Return to play, following acute epiglottitis, should include resolution of symptoms and a graded return to play, taking into consideration the level of deconditioning the athlete experienced from hospitalization.

  2. Application of solar radiation pressure to formation control near libration points

    NASA Astrophysics Data System (ADS)

    Li, Hongming

    In this dissertation, the use of solar radiation pressure (SRP) for spacecraft formation control near one of the collinear Sun-Earth or Earth-Moon libration points is investigated. Specifically, we consider whether formation spacecraft that are equipped with Sun-facing reflective surfaces (solar sail or sun shield) can exploit the solar radiation force that acts on them to perform gradual relative maneuvering. The relative motion between formation spacecraft with solar sail or sun shield near libration point is analyzed. A set of linearized equations of relative motion for libration point formations under differential solar radiation forcing is derived, with the sun shield or solar sail off-pointing angle taken as the control input variable. These equations are firstly used to study the formation reconfiguration problem. With this model, we study the existence and properties of solution trajectories that take the spacecraft from a given initial formation geometry to a desired final one in the Sun-Earth system. The existence of time-optimal transfer trajectories is also investigated. The problem of formation keeping using solar radiation pressure in the Sun-Earth system is then discussed. Since the amplitude of the SRP force is constrained by the area of sun shield and the permissible maximum off-pointing angle, the theory of regulator with constrained control is applied to design the formation-keeping controller in order to use the capacity of on-board sun shield more efficiently. A subtopic of adaption of frequency of out-of-plane relative motion using SRP is also presented. Finally, we extend the investigation to the Earth-Moon system. The modeling of relative motion with SRP in the vicinity of the translunar libration point is examined. A formation-keeping controller based on a set of equations of relative motion is developed.

  3. Pressure ulcer prevention in intensive care - a randomised control trial of two pressure-relieving devices.

    PubMed

    Theaker, C; Kuper, M; Soni, N

    2005-04-01

    Pressure sores are a potential complication of intensive care. Modern methods of pressure sore prevention centre around the use of pressure-relieving devices. Few studies exist that confirm the effectiveness of these devices. This study evaluates the effectiveness of two devices, the Hill-Rom Duo mattress and the KCI TheraPulse. High-risk patients were randomly assigned to receive one of two devices. We excluded those patients who had pressure sores upon admission. Those patients that did develop a pressure sore had their wound digitally photographed and graded by two independent tissue viability nurses. Sixty-two patients were included (30 TheraPulse, 32 Duo. Nine developed a pressure sore (6 Duo, 3 TheraPulse). No statistical differences between the two devices could be found. The longer a patient was nursed on a device, the greater the risk of pressure sore development. Despite the use of these devices, pressure sores can still develop in the Intensive Care patient population.

  4. Time course of muscle soreness following different types of exercise

    PubMed Central

    Vickers, Andrew J

    2001-01-01

    Background Post-exercise muscle soreness is a dull, aching sensation that follows unaccustomed muscular exertion. Primarily on the basis of previous laboratory-based research on eccentric exercise, soreness is usually said to follow an inverted U-shaped curve over time, peaking 24 – 48 hours after exercise. As such, it is often described as "delayed-onset" muscle soreness. In a study of long-distance runners, soreness seemed to peak immediately and then reduce gradually over time. The study is a secondary analysis of clinical trial data that aims to determine whether the time course of soreness following a natural exercise, long-distance running, is different from that following a laboratory-based exercise, bench-stepping. Methods This is a reanalysis of data from three previous clinical trials. The trials included 400 runners taking part in long-distance races and 82 untrained volunteers performing a bench-stepping test. Subjects completed a Likert scale of muscle soreness every morning and evening for the five days following their exercise. Results Interaction between trial and time is highly significant, suggesting a different time course of soreness following running and bench-stepping. 45% of subjects in the bench-stepping trial experienced peak soreness at the third or fourth follow-up (approximately 36 – 48 hours after exercise) compared to only 14% of those in the running trial. The difference between groups is robust to multivariate analysis incorporating possible confounding variables. Conclusion Soreness in runners following long-distance running follows a different time course to that in untrained individuals undertaking bench-stepping. Research on exercise taking place in the laboratory context does not necessarily generalize to exercise undertaken by trained athletes when engaged in their chosen sport. PMID:11701094

  5. Antibiotic prescribing in patients with self-reported sore throat

    PubMed Central

    Schilder, Anne; Fragaszy, Ellen; E. R. Evans, Hannah; Dukes, Oliver; Manikam, Logan; Little, Paul; Smith, Sarah C.; Hayward, Andrew

    2017-01-01

    Objectives: To investigate the predictors of general practitioner (GP) consultation and antibiotic use in those developing sore throat. Methods: We conducted a prospective population-based cohort study on 4461 participants in two rounds (2010–11) from 1897 households. Results: Participants reported 2193 sore throat illnesses, giving a community sore throat incidence of 1.57/ person-year. 13% of sore throat illnesses led to a GP consultation and 56% of these consultations led to antibiotic use. Participants most likely to have sore throats included women and children (e.g. school compared with retirement age); adjusted incidence rate ratio (aIRR) of 1.33 and 1.52, respectively. Participants with sore throat were more likely to consult their GP if they were preschool compared with retirement age [adjusted OR (aOR) 3.22], had more days of sore throat (aOR 1.11), reported more severe pain (aOR 4.24) or reported fever (aOR 3.82). Antibiotics were more often used by chronically ill individuals (aOR 1.78), those reporting severe pain (aOR 4.14), those reporting fever (aOR 2.58) or children with earache (aOR 1.85). Among those who consulted, males and adults who reported feeling anxious were more likely to use antibiotics; aOR 1.87 and 5.36, respectively. Conclusions: Only 1 in 10 people who have a sore throat see a doctor and more than half of those attending get antibiotics. Further efforts to curb antibiotic use should focus on reducing initial GP consultations through public information promoting safe self-management, targeted at groups identified above as most likely to attend with sore throats. PMID:27999063

  6. Effect of negative pressure on growth, secretion and biofilm formation of Staphylococcus aureus.

    PubMed

    Li, Tongtong; Wang, Guoqi; Yin, Peng; Li, Zhirui; Zhang, Licheng; Liu, Jianheng; Li, Ming; Zhang, Lihai; Han, Li; Tang, Peifu

    2015-10-01

    Negative pressure wound therapy (NPWT) has gained popularity in the management of contaminated wounds as an effective physical therapy, although its influence on the bacteria in the wounds remains unclear. In this study, we attempted to explore the effect of negative pressure conditions on Staphylococcus aureus, the most frequently isolated pathogen during wound infection. S. aureus was cultured in Luria-Bertani medium at subatmospheric pressure of -125 mmHg for 24 h, with the bacteria grown at ambient pressure as the control. The application of negative pressure was found to slow down the growth rate and inhibit biofilm development of S. aureus, which was confirmed by static biofilm assays. Furthermore, decreases in the total amount of virulence factors and biofilm components were observed, including α-hemolysin, extracellular adherence protein, polysaccharide intercellular adhesin and extracellular DNA. With quantitative RT-PCR analysis, we also revealed a significant inhibition in the transcription of virulence and regulatory genes related to wound infections and bacterial biofilms. Together, these findings indicated that negative pressure could inhibit the growth, virulence and biofilm formation of S. aureus. A topical subatmospheric pressure condition, such as NPWT, may be a potential antivirulence and antibiofilm strategy in the field of wound care.

  7. Formation mechanisms of rapid pressure recovery around a laminar separation bubble

    NASA Astrophysics Data System (ADS)

    Lee, Donghwi; Nonomura, Taku; Oyama, Akira; Fujii, Kozo

    2016-11-01

    Large-eddy simulations around 5 % thickness flat plate are conducted at Rec = 5 , 000 , 8 , 000 and 20 , 000 and formation mechanisms of rapid pressure recovery in the surface pressure distribution around laminar separation bubbles are analyzed. Three analyses are applied to investigate the mechanisms of rapid pressure recovery. First, by using the Reynolds averaged streamwise pressure gradient equation, it is confirmed that the "overall Reynolds stress diffusion (ORSD)" is an important factor for inducing rapid pressure recovery. Second, we decompose the ORSD into the "normal Reynolds stress diffusion in the streamwise direction" and the "tangential Reynolds stress diffusion (TRSD) in the wall-normal direction". We show that the TRSD in the wall-normal direction, which corresponds to the momentum transfer in the same direction, is the main contributor to the ORSD. Third, the TRSD in the wall-normal direction is decomposed into two- and three-dimensional components. The results indicate that the rapid pressure recovery is strongly affected by the presence of Reynolds stress rather than by the type of physical phenomena that creates the Reynolds stress. In other words, the three-dimensional turbulent structures are not a necessary condition for the rapid pressure recovery. Grain-in-Aid for JSPS Fellows.

  8. Does Pressure Accentuate General Relativistic Gravitational Collapse and Formation of Trapped Surfaces?

    NASA Astrophysics Data System (ADS)

    Mitra, Abhas

    2013-04-01

    It is widely believed that though pressure resists gravitational collapse in Newtonian gravity, it aids the same in general relativity (GR) so that GR collapse should eventually be similar to the monotonous free fall case. But we show that, even in the context of radiationless adiabatic collapse of a perfect fluid, pressure tends to resist GR collapse in a manner which is more pronounced than the corresponding Newtonian case and formation of trapped surfaces is inhibited. In fact there are many works which show such collapse to rebound or become oscillatory implying a tug of war between attractive gravity and repulsive pressure gradient. Furthermore, for an imperfect fluid, the resistive effect of pressure could be significant due to likely dramatic increase of tangential pressure beyond the "photon sphere." Indeed, with inclusion of tangential pressure, in principle, there can be static objects with surface gravitational redshift z → ∞. Therefore, pressure can certainly oppose gravitational contraction in GR in a significant manner in contradiction to the idea of Roger Penrose that GR continued collapse must be unstoppable.

  9. Formation of chemical bonds and morphological studies of a-CNx : Effects of PECVD deposition pressure

    NASA Astrophysics Data System (ADS)

    Purhanudin, Noorain; Awang, Rozidawati

    2016-11-01

    We report the structural difference and film properties of amorphous carbon nitride (a-CNx) thin films as a function of PECVD deposition pressure using precursor gases of ethane (C2H6) and nitrogen (N2). The Fourier transform infra-red (FTIR) spectra reveal peaks of single C-N (1100 cm-1), double C=C (1500 cm-1), double C=N (1670 cm-1) and triple C≡N (2340 cm-1). A systematic change in the preferential peaks correspond to the C=N and C≡N triple bonds were found to increase as deposition pressure increased. Field emission scanning electron microscopy (FESEM) provides morphological structure of the film. From the samples prepare at low deposition pressure, the particles tend to agglomerate into clusters with non-homogenous grains distributed over the surface. Higher deposition pressure results in coalescence process of the film, reflecting the formation of grains evenly distributed on the film. The film morphology is increased in voids structure with increase in deposition pressure. Finally, the samples were successfully prepared by PECVD technique with deposition pressure in varied, and the effect of deposition pressure on the chemical bonding and the morphology of the films had been studied.

  10. TURBULENCE SETS THE INITIAL CONDITIONS FOR STAR FORMATION IN HIGH-PRESSURE ENVIRONMENTS

    SciTech Connect

    Rathborne, J. M.; Contreras, Y.; Longmore, S. N.; Bastian, N.; Jackson, J. M.; Kruijssen, J. M. D.; Alves, J. F.; Bally, J.; Foster, J. B.; Garay, G.; Testi, L.; Walsh, A. J.

    2014-11-10

    Despite the simplicity of theoretical models of supersonically turbulent, isothermal media, their predictions successfully match the observed gas structure and star formation activity within low-pressure (P/k < 10{sup 5} K cm{sup –3}) molecular clouds in the solar neighborhood. However, it is unknown whether or not these theories extend to clouds in high-pressure (P/k > 10{sup 7} K cm{sup –3}) environments, like those in the Galaxy's inner 200 pc central molecular zone (CMZ) and in the early universe. Here, we present Atacama Large Millimeter/submillimeter Array 3 mm dust continuum emission within a cloud, G0.253+0.016, which is immersed in the high-pressure environment of the CMZ. While the log-normal shape and dispersion of its column density probability distribution function (PDF) are strikingly similar to those of solar neighborhood clouds, there is one important quantitative difference: its mean column density is one to two orders of magnitude higher. Both the similarity and difference in the PDF compared to those derived from solar neighborhood clouds match predictions of turbulent cloud models given the high-pressure environment of the CMZ. The PDF shows a small deviation from log-normal at high column densities confirming the youth of G0.253+0.016. Its lack of star formation is consistent with the theoretically predicted, environmentally dependent volume density threshold for star formation which is orders of magnitude higher than that derived for solar neighborhood clouds. Our results provide the first empirical evidence that the current theoretical understanding of molecular cloud structure derived from the solar neighborhood also holds in high-pressure environments. We therefore suggest that these theories may be applicable to understand star formation in the early universe.

  11. Turbulence Sets the Initial Conditions for Star Formation in High-pressure Environments

    NASA Astrophysics Data System (ADS)

    Rathborne, J. M.; Longmore, S. N.; Jackson, J. M.; Kruijssen, J. M. D.; Alves, J. F.; Bally, J.; Bastian, N.; Contreras, Y.; Foster, J. B.; Garay, G.; Testi, L.; Walsh, A. J.

    2014-11-01

    Despite the simplicity of theoretical models of supersonically turbulent, isothermal media, their predictions successfully match the observed gas structure and star formation activity within low-pressure (P/k < 105 K cm-3) molecular clouds in the solar neighborhood. However, it is unknown whether or not these theories extend to clouds in high-pressure (P/k > 107 K cm-3) environments, like those in the Galaxy's inner 200 pc central molecular zone (CMZ) and in the early universe. Here, we present Atacama Large Millimeter/submillimeter Array 3 mm dust continuum emission within a cloud, G0.253+0.016, which is immersed in the high-pressure environment of the CMZ. While the log-normal shape and dispersion of its column density probability distribution function (PDF) are strikingly similar to those of solar neighborhood clouds, there is one important quantitative difference: its mean column density is one to two orders of magnitude higher. Both the similarity and difference in the PDF compared to those derived from solar neighborhood clouds match predictions of turbulent cloud models given the high-pressure environment of the CMZ. The PDF shows a small deviation from log-normal at high column densities confirming the youth of G0.253+0.016. Its lack of star formation is consistent with the theoretically predicted, environmentally dependent volume density threshold for star formation which is orders of magnitude higher than that derived for solar neighborhood clouds. Our results provide the first empirical evidence that the current theoretical understanding of molecular cloud structure derived from the solar neighborhood also holds in high-pressure environments. We therefore suggest that these theories may be applicable to understand star formation in the early universe.

  12. Pressure Propagation and Brine Displacement in CO2 Storage Formations: The Role of Sealing Units

    NASA Astrophysics Data System (ADS)

    Tsang, C.; Birkholzer, J. T.; Zhou, Q.

    2007-12-01

    If carbon dioxide capture and storage technologies are implemented on a large scale, enormous amounts of CO2 will be injected and sequestered underground, which means that large volumes of native brines will be displaced. Provided that there is hydraulic communication to shallow formations, such brine displacement from deep storage reservoirs may impact the hydrologic conditions in fresh-water aquifers, for example affecting groundwater table levels or discharge and recharge zones. In some cases, brines or brackish water may also be displaced into the capture zone of fresh-water wells. To explore the conditions important for pressure propagation and brine displacement, we conduct a simulation study investigating the multiphase processes resulting from CO2 injection into a large multi-layer geologic system comprising of a storage formation and the confining low- permeability sealing units. The pressure changes and transport patterns within the storage formation are evaluated as a function of time and distance from the injection point. We are particularly interested in the role of pressure mitigation and vertical brine flow through the upper and lower sealing units. Several sensitivity cases are therefore considered varying the permeability of the upper and lower sealing units within reasonable ranges. Our results suggest that seal conductivities on the order of 0.1 to 0.001 millidarcy may allow for considerable pressure attenuation in the storage formation by interlayer brine migration, while still providing an effective barrier to CO2 leakage (since they serve as capillary and permeability seals). It is thus important to fully understand the multi-layer characteristics of a storage site if the possible environmental impacts of CO2 injection on fresh-water aquifers are to be investigated. In addition to conducting detailed simulations of the multi-phase processes, we also investigate whether existing analytical solutions for well drawdown in leaky aquifers can

  13. Operational design and pressure response of large-scale compressed air energy storage in porous formations

    NASA Astrophysics Data System (ADS)

    Wang, Bo; Bauer, Sebastian

    2017-04-01

    With the rapid growth of energy production from intermittent renewable sources like wind and solar power plants, large-scale energy storage options are required to compensate for fluctuating power generation on different time scales. Compressed air energy storage (CAES) in porous formations is seen as a promising option for balancing short-term diurnal fluctuations. CAES is a power-to-power energy storage, which converts electricity to mechanical energy, i.e. highly pressurized air, and stores it in the subsurface. This study aims at designing the storage setup and quantifying the pressure response of a large-scale CAES operation in a porous sandstone formation, thus assessing the feasibility of this storage option. For this, numerical modelling of a synthetic site and a synthetic operational cycle is applied. A hypothetic CAES scenario using a typical anticline structure in northern Germany was investigated. The top of the storage formation is at 700 m depth and the thickness is 20 m. The porosity and permeability were assumed to have a homogenous distribution with a value of 0.35 and 500 mD, respectively. According to the specifications of the Huntorf CAES power plant, a gas turbine producing 321 MW power with a minimum inlet pressure of 43 bars at an air mass flowrate of 417 kg/s was assumed. Pressure loss in the gas wells was accounted for using an analytical solution, which defines a minimum bottom hole pressure of 47 bars. Two daily extraction cycles of 6 hours each were set to the early morning and the late afternoon in order to bypass the massive solar energy production around noon. A two-year initial filling of the reservoir with air and ten years of daily cyclic operation were numerically simulated using the Eclipse E300 reservoir simulator. The simulation results show that using 12 wells the storage formation with a permeability of 500 mD can support the required 6-hour continuous power output of 321MW, which corresponds an energy output of 3852 MWh per

  14. Pressure-temperature evolution of Neoproterozoic metamorphism in the Welayati Formation (Kabul Block), Afghanistan

    NASA Astrophysics Data System (ADS)

    Collett, Stephen; Faryad, Shah Wali

    2015-11-01

    The Welayati Formation, consisting of alternating layers of mica-schist and quartzite with lenses of amphibolite, unconformably overlies the Neoarchean Sherdarwaza Formation of the Kabul Block that underwent Paleoproterozoic granulite-facies and Neoproterozoic amphibolite-facies metamorphic events. To analyze metamorphic history of the Welayati Formation and its relations to the underlying Sherdarwaza Formation, petrographic study and pressure-temperature (P-T) pseudosection modeling were applied to staurolite- and kyanite-bearing mica-schists, which crop out to the south of Kabul City. Prograde metamorphism, identified by inclusion trails and chemical zonation in garnet from the micaschists indicates that the rocks underwent burial from around 6.2 kbar at 525 °C to maximum pressure conditions of around 9.5 kbar at temperatures of around 650 °C. Decompression from peak pressures under isothermal or moderate heating conditions are indicated by formation of biotite and plagioclase porphyroblasts which cross-cut and overgrow the dominant foliation. The lack of sillimanite and/or andalusite suggests that cooling and further decompression occurred in the kyanite stability field. The results of this study indicate a single amphibolite-facies metamorphism that based on P-T conditions and age dating correlates well with the Neoproterozoic metamorphism in the underlying Sherdarwaza Formation. The rocks lack any paragenetic evidence for a preceding granulite-facies overprint or subsequent Paleozoic metamorphism. Owing to the position of the Kabul Block, within the India-Eurasia collision zone, partial replacement of the amphibolite-facies minerals in the micaschist could, in addition to retrogression of the Neoproterozoic metamorphism, relate to deformation associated with the Alpine orogeny.

  15. The formation of chondrules at high gas pressures in the solar nebula.

    PubMed

    Galy, A; Young, E D; Ash, R D; O'Nions, R K

    2000-12-01

    High-precision magnesium isotope measurements of whole chondrules from the Allende carbonaceous chondrite meteorite show that some aluminum-rich Allende chondrules formed at or near the time of formation of calcium-aluminum-rich inclusions and that some others formed later and incorporated precursors previously enriched in magnesium-26. Chondrule magnesium-25/magnesium-24 correlates with [magnesium]/[aluminum] and size, the aluminum-rich, smaller chondrules being the most enriched in the heavy isotopes of magnesium. These relations imply that high gas pressures prevailed during chondrule formation in the solar nebula.

  16. Formation processes of nanometer sized particles in low pressure Ar/CH{sub 4} rf plasmas

    SciTech Connect

    Beckers, J.; Vacaresse, G. D. G. J.; Stoffels, W. W.

    2008-09-07

    In this paper, formation and growth processes of nanometer and micrometer sized dust particles in low pressure Ar/CH{sub 4} rf (13.56 MHz) plasmas are investigated as function of temperature in the range 25-100 deg. C. During experiments the pressure was typically 0.8 mbar and the forward power to the plasma was {approx}70 Watt. Measuring the fundamental voltage, current and phase angle together with their harmonics (up to the fourth) gives a good method to monitor the creation and growth of these dust particles in time. Furthermore, laser light scattering measurements are performed to give information about the dust particle density. It has been shown that dust particle formation in these conditions depends greatly on temperature.

  17. Pressure dependence of the compressibility of a micelle and a protein: insights from cavity formation analysis

    NASA Astrophysics Data System (ADS)

    Pereira, Brian; Jain, Sandeep; Sarupria, Sapna; Yang, Lu; Garde, Shekhar

    We present results from molecular dynamics simulations of a spherical micelle comprising 80 non-ionic C8E5 surfactants in water, a protein staphylococcal nuclease in water, and bulk n-hexane and water liquids over a range of hydrostatic pressures. We focus specifically on the pressure dependence of the volumetric properties - the partial molar volume and partial molar compressibility - of the micelle, the protein, and bulk liquids. We find that the micelle interior displays properties similar to liquid alkanes over a range of pressures and has a compressibility of ˜100-110×10-6 bar-1 under ambient conditions, which is more than twice that of liquid water. In contrast, the pressure dependence of the protein interior resembles that of solid organic polymeric materials and has a compressibility of ˜ 5-10×10-6 bar-1. We performed extensive analysis of cavity formation in all systems. Interestingly, it is not the average cavity size but the width of the cavity size distribution in a given medium that correlates with the compressibility of that medium over a broad range of pressures up to several kilobars. Correspondingly, the cavity size distribution is most sharply defined in protein interiors and is broadest in the micelle interior and in n-hexane. To explore the correlation between cavity formation and compressibility, we present preliminary calculations using the information theory approach in the bulk water phase. Analysis of cavity formation and, especially, the nature of the cavity size distribution may provide a sensitive probe of the compressibility and flexibility of local molecular environments in inhomogeneous condensed media.

  18. Prediction of Fracture Initiation Pressure and Fracture Geometries in Elastic Isotropic and Anisotropic Formations

    NASA Astrophysics Data System (ADS)

    Li, H.; Zou, Y. S.; Liu, S.; Liu, G. Q.; Jing, Y. Z.; Ehlig-Economides, C. A.

    2017-03-01

    Laminated formation structures in shale formations may have elastic anisotropic properties, including Young's modulus and Poisson's ratio, that impact hydraulic fracturing treatment execution. Fracture initiation pressures and geometries are affected by these properties, especially in cased and in perforated horizontal wells. After initiation, stress concentration around the wellbore may cause the creation of longitudinal fractures (LFs) in the near-wellbore zone that reorient to transverse fractures (TFs) beyond this region. In this case, severe fracture kinking may occur that may hinder the transport of proppants and reduce well productivity. We developed an analytical model based on linear fracture mechanics theory to study the effect of perforation geometries on the initiation fracture pattern. Elastic anisotropy and well deviations were incorporated into simulations. Our simulation results show that when the perforation depth is in a specific range under normal fault regime, the initiation pressures for LFs can be smaller than the maximum horizontal stress σH. This behavior is significant for a smaller σH /σv ratio, but it vanishes for a larger σH /σv ratio. With increasing formation elastic anisotropy (K_{aniso}), the initiation pressures for both LFs and TFs increase, and the critical perforation depth is decreased. Considering the well deviation, the well azimuth and inclination angles affect initiation pressures for both longitudinal and transverse fractures. Results show how perforation depth, shale elastic anisotropy, and well orientation affect fracture initiation patterns. This paper provides a framework for well completion designs and well orientation designs to minimize the fracture kinking in the near-wellbore region in shale formations.

  19. Can You Get Genital Herpes from a Cold Sore?

    MedlinePlus

    ... Lucy* Yes — it is possible to get genital herpes from oral sex. Genital herpes is caused by the herpes ... Genital herpes is usually caused by HSV-2; oral herpes (cold sores) is usually caused by HSV-1. ...

  20. When a Sore Throat Is a More Serious Infection

    MedlinePlus

    ... Head Neck & Nervous System Heart Infections Learning Disabilities Obesity Orthopedic Prevention Sexually Transmitted Skin Tobacco Treatments Injuries & ... sore throat, because strep infections are treated with antibiotics. Diagnosis and Treatment If your child has a ...

  1. Effect of Saturation Pressure Difference on Metal–Silicide Nanopowder Formation in Thermal Plasma Fabrication

    PubMed Central

    Shigeta, Masaya; Watanabe, Takayuki

    2016-01-01

    A computational investigation using a unique model and a solution algorithm was conducted, changing only the saturation pressure of one material artificially during nanopowder formation in thermal plasma fabrication, to highlight the effects of the saturation pressure difference between a metal and silicon. The model can not only express any profile of particle size–composition distribution for a metal–silicide nanopowder even with widely ranging sizes from sub-nanometers to a few hundred nanometers, but it can also simulate the entire growth process involving binary homogeneous nucleation, binary heterogeneous co-condensation, and coagulation among nanoparticles with different compositions. Greater differences in saturation pressures cause a greater time lag for co-condensation of two material vapors during the collective growth of the metal–silicide nanopowder. The greater time lag for co-condensation results in a wider range of composition of the mature nanopowder.

  2. Polymorphism and Formation Mechanism of Nanobipods in Manganese Sulfide Nanocrystals Induced by Temperature or Pressure

    SciTech Connect

    Yang, Xinyi; Wang, Yingnan; Wang, Kai; Sui, Yongming; Zhang, Meiguang; Li, Bing; Ma, Yanming; Liu, Bingbing; Zou, Guangtian; Zou, Bo

    2012-03-15

    Manganese sulfide (MnS) nanocrystals (NCs) with three different phases were synthesized by one-pot solvent thermal approach. The crystal structures and morphologies were investigated using powder X-ray diffraction, transmission electron microscopy, and high-resolution transmission electron microscopy. We found that the crystal structure and morphology of MnS NCs could be controlled by simply varying the reaction temperature. The detailed growth process of MnS nanobipods, including the zinc blende (ZB)-core formation and wurtzite (WZ)-arms growth, provides direct experimental evidence for the polymorphism model. Furthermore, we have studied the stability of metastable ZB- and WZ-MnS NCs under high pressure and found that ZB-nanoparticles and ZB/WZ-nanobipods are stable below their critical pressure, 5.3 and 2.9 GPa, respectively. When pressures exceed the critical point, all these metastable MnS NCs directly convert to the stable rock salt MnS.

  3. Explicit modelling of SOA formation from α-pinene photooxidation: sensitivity to vapour pressure estimation

    NASA Astrophysics Data System (ADS)

    Valorso, R.; Aumont, B.; Camredon, M.; Raventos-Duran, T.; Mouchel-Vallon, C.; Ng, N. L.; Seinfeld, J. H.; Lee-Taylor, J.; Madronich, S.

    2011-07-01

    The sensitivity of the formation of secondary organic aerosol (SOA) to the estimated vapour pressures of the condensable oxidation products is explored. A highly detailed reaction scheme was generated for α-pinene photooxidation using the Generator for Explicit Chemistry and Kinetics of Organics in the Atmosphere (GECKO-A). Vapour pressures (Pvap) were estimated with three commonly used structure activity relationships. The values of Pvap were compared for the set of secondary species generated by GECKO-A to describe α-pinene oxidation. Discrepancies in the predicted vapour pressures were found to increase with the number of functional groups borne by the species. For semi-volatile organic compounds (i.e. organic species of interest for SOA formation), differences in the predicted Pvap range between a factor of 5 to 200 on average. The simulated SOA concentrations were compared to SOA observations in the Caltech chamber during three experiments performed under a range of NOx conditions. While the model captures the qualitative features of SOA formation for the chamber experiments, SOA concentrations are systematically overestimated. For the conditions simulated, the modelled SOA speciation appears to be rather insensitive to the Pvap estimation method.

  4. Explicit modelling of SOA formation from α-pinene photooxidation: sensitivity to vapour pressure estimation

    NASA Astrophysics Data System (ADS)

    Valorso, R.; Aumont, B.; Camredon, M.; Raventos-Duran, T.; Mouchel-Vallon, C.; Ng, N. L.; Seinfeld, J. H.; Lee-Taylor, J.; Madronich, S.

    2011-03-01

    The sensitivity of the formation of secondary organic aerosol (SOA) to the estimated vapour pressures of the condensable oxidation products is explored. A highly detailed reaction scheme was generated for α-pinene photooxidation using the Generator for Explicit Chemistry and Kinetics of Organics in the Atmosphere (GECKO-A). Vapour pressures (Pvap) were estimated with three commonly used structure activity relationships. The values of Pvap were compared for the set of secondary species generated by GECKO-A to describe α-pinene oxidation. Discrepancies in the predicted vapour pressures were found to increase with the number of functional groups borne by the species. For semi-volatile organic compounds (i.e. organic species of interest for SOA formation), differences in the predicted Pvap range between a factor of 5 to 200 in average. The simulated SOA concentrations were compared to SOA observations in the Caltech chamber during three experiments performed under a range of NOx conditions. While the model captures the qualitative features of SOA formation for the chamber experiments, SOA concentrations are systematically overestimated. For the conditions simulated, the modelled SOA speciation appears to be rather insensitive to the Pvap estimation method.

  5. Guideline for the management of acute sore throat.

    PubMed

    Pelucchi, C; Grigoryan, L; Galeone, C; Esposito, S; Huovinen, P; Little, P; Verheij, T

    2012-04-01

    The European Society for Clinical Microbiology and Infectious Diseases established the Sore Throat Guideline Group to write an updated guideline to diagnose and treat patients with acute sore throat. In diagnosis, Centor clinical scoring system or rapid antigen test can be helpful in targeting antibiotic use. The Centor scoring system can help to identify those patients who have higher likelihood of group A streptococcal infection. In patients with high likelihood of streptococcal infections (e.g. 3-4 Centor criteria) physicians can consider the use of rapid antigen test (RAT). If RAT is performed, throat culture is not necessary after a negative RAT for the diagnosis of group A streptococci. To treat sore throat, either ibuprofen or paracetamol are recommended for relief of acute sore throat symptoms. Zinc gluconate is not recommended to be used in sore throat. There is inconsistent evidence of herbal treatments and acupuncture as treatments for sore throat. Antibiotics should not be used in patients with less severe presentation of sore throat, e.g. 0-2 Centor criteria to relieve symptoms. Modest benefits of antibiotics, which have been observed in patients with 3-4 Centor criteria, have to be weighed against side effects, the effect of antibiotics on microbiota, increased antibacterial resistance, medicalisation and costs. The prevention of suppurative complications is not a specific indication for antibiotic therapy in sore throat. If antibiotics are indicated, penicillin V, twice or three times daily for 10 days is recommended. At the present, there is no evidence enough that indicates shorter treatment length. © 2012 The Authors. Clinical Microbiology and Infection © 2012 European Society of Clinical Microbiology and Infectious Diseases.

  6. Design and Development of Portable Support Surface and Multilayered Fabric Cover for Bed Sore Prevention.

    PubMed

    Kandha Vadivu, P

    2015-12-01

    Pressure ulcers are serious and common health concern affecting about 1.5-3 million adults and is a serious health concern for elders. Pressure ulcers or bed sores seem to be one of the most challenging inflicts to the doctors and may result in significant morbidity and mortality and are associated with high cost in terms of human sufferings, cost of treatment, and possible litigation. Though modern medical science has launched a variety of treatment methods, prevention is the best way to get rid of it. Pressure sores are best prevented by using support surfaces that are volatile in nature-like water mattress, variable pressure mattress, etc. In this research work, a portable support surface has been designed and developed for preventing bedsore. It consists of four individual components for the body part such as bodice back, hip, elbow, and heel which are likely to be affected by bedsores. Each component has volatile surface provisions in them with refilling and cleaning facility. The portable support surface is easy to wear and remove and also cheaper. Above all, the kit is user-friendly with no side effects and preferred and guaranteed by the doctors.

  7. Effects of Fish Oil Supplementation on Postresistance Exercise Muscle Soreness.

    PubMed

    Tinsley, Grant M; Gann, Joshua J; Huber, Stefan R; Andre, Thomas L; La Bounty, Paul M; Bowden, Rodney G; Gordon, Paul M; Grandjean, Peter W

    2016-07-21

    The aim of this study was to examine the effects of fish oil supplementation on the magnitude and time-course of postresistance exercise muscle soreness. This study was a randomized, placebo-controlled, double-blind trial. Nonresistance trained females were randomized into one of two groups: fish oil supplementation (6 g/day; 5:1 eicosapentaenoic acid to docosahexaenoic acid (EPA:DHA)) or placebo (6 g/day corn/soy oil). After consuming the supplements for one week, participants underwent a single bout of resistance exercise consisting of 10 sets to failure of elbow flexion and leg extension machines. Muscle soreness was measured daily over the next week via grounded visual analog scale while participants continued to consume their assigned supplement. At 48 hours and one week postexercise, soreness during functional movements and limb circumferences were measured. The fish oil group perceived less static and functional muscle soreness than placebo, although the differences were not statistically significant. Effect sizes for resistance exercise-induced static and functional soreness responses were 33 to 42% lower in fish oil versus placebo without changes in upper arm and thigh circumferences. Supplementing the diet with 6 g per day of fish oil may alleviate muscle soreness experienced after resistance training in young untrained females.

  8. Star formation in a high-pressure environment: An SMA view of the dust ridge

    NASA Astrophysics Data System (ADS)

    Walker, Daniel L.

    2017-01-01

    The star formation rate in the Central Molecular Zone is an order of magnitude lower than in the disk of the Galaxy, given the amount of dense gas there. Understanding why star formation is different in this region is crucial if we are to understand the environmental dependence of star formation. Here, we present the detection of high-mass cores in the CMZ's `dust ridge' that have been discovered with the Submillimeter Array. These cores range in mass from ~ 50 - 1800 M⊙ within radii of 0.1 - 0.25 pc. All are young (pre-UCHII), meaning that they are prime candidates for representing the initial conditions of high-mass stars and sub-clusters. We compare these with high-mass cores and clouds in the Galactic disk and find that they are very similar in terms of their masses and sizes, despite being subjected to external pressures that are several magnitudes greater (~ 108 K cm-3). The fact that > 80% of these cores do not show any signs of star-forming activity in such a high-pressure environment leads us to conclude that this is further evidence of the critical density for star formation being heightened in the CMZ due to turbulence.

  9. Simulation of non-ionic surfactant micelle formation across a range of temperature and pressure

    NASA Astrophysics Data System (ADS)

    Custer, Gregory; Das, Payel; Matysiak, Silvina

    Non-ionic surfactants can, at certain concentrations and thermodynamic conditions, aggregate into micelles due to their amphiphilic nature. Our work looks at the formation and behavior of micelles at extremes of temperature and pressure. Due to the large system size and simulation time required to study micelle formation, we have developed a coarse-grained (CG) model of our system. This CG model represents each heavy atom with a single CG bead. We use the multibody Stillinger-Weber potential, which adds a three-body angular penalty to a two-body potential, to emulate hydrogen bonds in the system. We simulate the linear surfactant C12E5 , which has a nonpolar domain of 12 carbons and a polar domain of 5 ethers. Our CG model has been parameterized to match structural properties from all-atom simulations of single and dimer surfactant systems. Simulations were performed using a concentration above the experimental critical micelle concentration at 300K and 1atm. We observe an expected region of stable micelle formation at intermediate temperature, with a breakdown at high and low temperature, as well as at high pressure. The driving forces behind the destabilization of micelles and the mechanism of micelle formation at different thermodynamic conditions will be discussed.

  10. Kinetic criteria of glass formation and the pressure dependence of the glass transition temperature.

    PubMed

    Schmelzer, Jürn W P

    2012-02-21

    An overview on different attempts of formulation of kinetic criteria of glass formation is given. It is analyzed which of the characteristic time scales-time of observation, time of relaxation, and time of change of external parameters-have to be employed to appropriately develop such criteria. Based on this analysis, a general model-independent kinetic criterion for glass formation is formulated. As a first consequence, it is shown that it is not-as often claimed-the Deborah number which governs glass formation. Based on this general kinetic criterion for glass formation, general expressions for the dependence of the glass transition temperature on pressure (and vice versa) are obtained being essentially ratios of the partial derivatives of the appropriate relaxation times with respect to pressure and temperature, respectively. Employing, as examples, further two different (free volume and entropy based) models for the description of viscous flow and relaxation, respectively, relations similar but, in general, not identical to the classical Ehrenfest relations describing second-order equilibrium phase transitions are obtained. In this way, it can be explained why one of the Ehrenfest's relations is usually fulfilled in glass transition and the other not and why the Prigogine-Defay ratio in glass transition is not equal to one as this is the case with Ehrenfest's ratio in second-order equilibrium phase transitions. © 2012 American Institute of Physics

  11. Ionized gas pressure correlates with star formation intensity in nearby starbursts

    NASA Astrophysics Data System (ADS)

    Jiang, Tianxing; Malhotra, Sangeeta; Yang, Huan

    2016-06-01

    We estimate the electron density of the ionized gas and thus the thermal pressure in HII regions; and compare that to the SFR (star formation rate) surface density for a combined sample of about 40 green peas and Lyman Break Analogs at z < 0.30. The electron density of the ionized gas is measured from sulfur line ratio ([SII] 6716 / 6731). We find that the SFR surface density is correlated with the electron density and the thermal pressure in HII regions for the star-forming galaxies with SFR surface density above a certain threshold. This work shows quantitatively the correlation between SFR surface density and electron density and that between SFR surface density and the thermal pressure in HII regions for the nearby starburst galaxies. This is consistent with theoretical models of disks (e.g. Kim et al. (2011) if we assume that the thermal pressure in HII regions is comparable to the total diffuse gas pressure at the midplane of the diffuse neutral gas. It is also in agreement with the results from star-forming galaxies at z ~ 2.5. We might infer that the starburst galaxies at low-redshift (z < 0.3) share similar physical properties to the galaxies at high redshift (z ~ 2.5).

  12. Study the formation mechanism of silicon carbide polytype by silicon carbide nanobelts sintered under high pressure.

    PubMed

    Wei, Guodong; Zhang, Guangqian; Gao, Fenmei; Zheng, Jinju; Qin, Yanfen; Han, Wei; Qin, Weiping; Yang, Weiyou

    2011-11-01

    In this paper, in order to reveal the formation mechanism of SiC polytype, four SiC specimens sintered under high pressure has been investigated, after being prepared from SiC nanobelts as initial powders. The structure and morphology variation dependence of SiC specimens with temperature and pressure was studied based on experimental data obtained by XRD, SEM, and Raman. The results show that SiC lattice structure and the crystallite size are greatly affected by pressure between 2 and 4 GPa under different sintering temperatures of 800 and 1200 degrees C. At the largest applied pressure and temperature, 4 GPa and 1200 degrees C, 3C-SiC crystal structure can be changed into to R-SiC due to the stress resulted in dislocations instead of planar defects. Based on our results, the multiquantum-well structure based a single one-dimensional nanostructure can be achieved by applying high pressure at certain sintered temperature.

  13. Ketamine gargle for attenuating postoperative sore throat.

    PubMed

    Canbay, O; Celebi, N; Sahin, A; Celiker, V; Ozgen, S; Aypar, U

    2008-04-01

    Tracheal intubation is a foremost cause of trauma to the airway mucosa, resulting in postoperative sore throat (POST) with reported incidences of 21-65%. We compared the effectiveness of ketamine gargles with placebo in preventing POST after endotracheal intubation. Forty-six, ASA I-II, patients undergoing elective surgery for septorhinoplasty under general anaesthesia were enrolled in this prospective, randomized, placebo-controlled, single-blind study. Patients were randomly allocated into two groups of 23 subjects each: Group C, saline 30 ml; Group K, ketamine 40 mg in saline 30 ml. Patients were asked to gargle this mixture for 30 s, 5 min before induction of anaesthesia. POST was graded at 0, 2, 4, and 24 h after operation on a four-point scale (0-3). POST occurred more frequently in Group C, when compared with Group K, at 0, 2, and 24 h and significantly more patients suffered severe POST in Group C at 4 and 24 h compared with Group K (P<0.05). Ketamine gargle significantly reduced the incidence and severity of POST.

  14. Pressure dependence of stabilized Criegee intermediate formation from a sequence of alkenes.

    PubMed

    Drozd, Greg T; Donahue, Neil M

    2011-05-05

    Ozonolysis is a key reaction in atmospheric chemistry, although important details of the behavior of the ozonolysis intermediates are not known. The key intermediate in ozonolysis, the Criegee intermeiate (CI), is known to quickly isomerize, with the favored unimolecular pathway depending on the relative barriers to isomerization. Stabilized Criegee intermediates (SCI), those with energy below any barriers to isomerization, may result from initial formation with low energy or collisional stabilization of high energy CI. Bimolecular reactions of SCI have been proposed to play a role in OH formation and nucleation of new particles, but unimolecular reactions of SCI may well be too fast for these to be significant. We present measurements of the pressure dependence of SCI formation for a set of alkenes utilizing a hexafluoroacetone scavenger. We studied four alkenes (2,3-dimethyl-2-butene (TME), trans-5-decene, cyclohexene, α-pinene) to characterize how size and cyclization (endo vs exo) affect the stability of Criegee intermediates formed in ozonolysis. SCI yields in ozonolysis were measured in a high pressure flow reactor within a range of 30-750 Torr. The linear alkenes show considerable stabilization with trans-5-decene showing 100% stabilization at ∼400 Torr and TME having 65% stabilization at 710 Torr. Extrapolation of the yields for linear alkenes to 0 Torr shows yields significantly above zero, indicating that a fraction of their CI are formed below the barrier to isomerization. CI from endocyclic alkenes show little to no stabilization and appear to have neglible stabilization at 0 Torr. Cyclohexene derived CI showed no stabilization even at 650 Torr, while α-pinene CI had ∼15% stabilization at 740 Torr. Our results show a strong dependence of SCI formation on carbon number; adding just 2 to 3 CI carbons in linear alkenes increases stabilization by a factor of 10. Stabilization for endocyclic alkenes, at atmospheric pressure, begins to occur at a carbon

  15. Direct measurement of the differential pressure during drop formation in a co-flow microfluidic device.

    PubMed

    Xu, Ke; Tostado, Chris P; Xu, Jian-Hong; Lu, Yang-Cheng; Luo, Guang-Sheng

    2014-04-07

    In this study, we developed a new method for the direct measurement of differential pressures in a co-flow junction microfluidic device using a Capillary Laplace Gauge (CLG). The CLG - used inside the microchannel device--was designed using a tapered glass-capillary set up in co-flow junction architecture with a three-phase liquid-liquid-gas system with two flowing liquid phases and an entrained gas phase. By taking advantage of the Laplace equation, basic geometric relations and an integrated image analysis program, the movement of the entrained gas phase with the flow of the liquid-phases is tracked and monitored, allowing the gauge to function as an ultra-sensitive, integrated, differential pressure sensor measuring fluctuations in the liquid-dispersed phase channel pressure as small as tens of Pascals caused by droplet formation. The gauge was used to monitor the drop formation and breakup process in a co-flow junction microfluidic device under different flow conditions across a large range (1 × 10(-3) to 2.0 × 10(-1)) of capillary numbers. In addition to being able to monitor short and long term dispersed phase pressure fluctuation trends for both single drop and large droplet populations, the gauge was also used to clearly identify a transition between the dripping and jetting flow regimes. Overall, the combination of a unique, integrated image analysis program with this new type of sensor serves as a powerful tool with great potential for a variety of different research and industrial applications requiring sensitive microchannel pressure measurements.

  16. High Pressure Metal-Silicate Partitioning of Molybdenum and Constraints on Core Formation

    NASA Astrophysics Data System (ADS)

    Burkemper, L. K.; Agee, C. B.; Garcia, K. A.

    2011-12-01

    Over 12 new high pressure Mo metal-silicate partitioning experiments were performed in the pressure (P) and temperature (T) range of 3-8 GPa and 2173-2373 K. Parameterization of our data and literature data, limited to experiments with an Fe-rich metal phase and no light elements, produces a PT solution set that is compatible with the magma ocean hypothesis, and can be used to further constrain core formation models. The goal of these models is to reproduce the siderophile element abundances observed in Earth's mantle. The mantle is depleted in siderophile elements relative to chondrites as a result of their affinity for the metal phase during core formation. Metal-silicate partitioning experiments on the siderophile elements Ni and Co have provided valuable constraints on the PT conditions of core formation. Li and Agee (1996) showed that at 2273 K and pressures above 28 GPa, equilibrium core formation, such as in a magma ocean, can explain the observed mantle depletion of Ni and Co. Compared to Ni and Co, there is a paucity of data on the siderophile element Mo, especially at high pressure. Only 15 partitioning experiments have been performed at pressures above 1.5 GPa, which leads to large errors when the results are extrapolated to the higher pressure conditions of core formation. Consequentially, Mo has been left out of most core formation models such as those proposed by Rubie et al. (2011) and Wade and Wood (2005). Increasing the number of Mo partitioning data points will provide much needed additional constraints on core formation. All of our experiments were performed on a Walker-type multi-anvil press at the Institute of Meteoritics. Run products were analyzed by EPMA with a 20 μm broad beam. Crushable MgO capsules were used in all experiments. With this capsule material there is significant MgO infiltration into the silicate; however, MgO is already part of the system so it is more ideal than graphite capsules which impart a significant carbon component

  17. Analysis of Pore Pressure and Stress Distribution around a Wellbore Drilled in Chemically Active Elastoplastic Formations

    NASA Astrophysics Data System (ADS)

    Roshan, Hamid; Rahman, S. S.

    2011-09-01

    Drilling in low-permeable reactive shale formations with water-based drilling mud presents significant challenges, particularly in high-pressure and high-temperature environments. In previous studies, several models were proposed to describe the thermodynamic behaviour of shale. Most shale formations under high pressure are expected to undergo plastic deformation. An innovative algorithm including work hardening is proposed in the framework of thermo-chemo-poroelasticity to investigate the effect of plasticity on stresses around the wellbore. For this purpose a finite-element model of coupled thermo-chemo-poro-elastoplasticity is developed. The governing equations are based on the concept of thermodynamics of irreversible processes in discontinuous systems. In order to solve the plastic problem, a single-step backward Euler algorithm containing a yield surface-correction scheme is used to integrate the plastic stress-strain relation. An initial stress method is employed to solve the non-linearity of the plastic equation. In addition, super convergent patch recovery is used to accurately evaluate the time-dependent stress tensor from nodal displacement. The results of this study reveal that thermal and chemical osmosis can significantly affect the fluid flow in low-permeable shale formations. When the salinity of drilling mud is higher than that of pore fluid, fluid is pulled out of the formation by chemical osmotic back flow. Similar results are observed when the temperature of drilling mud is lower than that of the formation fluid. It is found that linear elastic approaches to wellbore stability analysis appear to overestimate the tangential stress around the wellbore and produce more conservative stresses compared to the results of field observation. Therefore, the drilling mud properties obtained from the elastoplastic wellbore stability in shales provide a safer mud weight window and reduce drilling cost.

  18. Effects of pressure on the mechanisms of soot formation and oxidation in laminar diffusion flames

    NASA Astrophysics Data System (ADS)

    Kim, Chul Han

    Soot processes within flames fueled with hydrocarbons are important because they affect the durability and performance of propulsion systems, the danger associated with unwanted fires, the pollutant and particulate emissions of combustion processes, local and global environments and the potential for developing computational combustion. The objective of the current work was to improve understanding of the processes controlling soot formation in combustion systems over a broad range of pressure conditions. The flame and soot structure, including primary soot particle nucleation, soot particle surface growth and oxidation properties, of round laminar diffusion flames were studied experimentally at pressures of 0.1-8.0 atm. Acetylene-nitrogen mixtures were used at pressures from 0.1 to 1.0 atm (in air coflow). Ethylene-helium mixtures were used at pressures from 1.0 to 8.0 atm (in oxygen/helium coflow). Soot concentrations, soot temperatures, soot structure, concentrations of major stable gas species, concentrations of radical species (H, OH, O), and flow velocities were measured along the axis of each flame studied. The data were analyzed to determine local soot surface growth, oxidation and nucleation rates, as well as local flame properties that are thought to affect these rates. The measurements of soot surface growth rates were consistent with earlier measurements in laminar premixed and diffusion flames involving a variety of hydrocarbons at atmospheric pressure. In addition, the growth rates from all the available flames were in good agreement with each other and with existing hydrogen-abstraction/carbon-addition (HACA) soot surface growth mechanisms available in the literature. Measurements of soot surface oxidation rates were consistent with earlier measurements, and the oxidation rates from all available flame data could be explained by reaction with OH; supplemented to only a minor degree by direct soot surface oxidation by O2. A simplified method to

  19. Nipple care, sore nipples, and breastfeeding: a randomized trial.

    PubMed

    Centuori, S; Burmaz, T; Ronfani, L; Fragiacomo, M; Quintero, S; Pavan, C; Davanzo, R; Cattaneo, A

    1999-06-01

    Sore and cracked nipples are common and may represent an obstacle to successful breastfeeding. In Italy, it is customary for health professionals to prescribe some type of ointment to prevent or treat sore and cracked nipples. The efficacy of these ointments is insufficiently documented. The incidence of sore and cracked nipples was compared between mothers given routine nipple care, including an ointment (control group), and mothers instructed to avoid the use of nipple creams and other products (intervention group). Breastfeeding duration was also compared between the two groups. Eligible mothers were randomly assigned, after informed consent, to one of the two groups. No difference was found between the control (n = 96) and the intervention group (n = 123) in the incidence of sore and cracked nipples and in breastfeeding duration. However, several factors were associated with sore nipples and with breastfeeding duration. The use of a pacifier and of a feeding bottle in the hospital were both associated with sore nipples at discharge (p = 0.02 and p = 0.03, respectively). Full breastfeeding up to 4 months postpartum was significantly associated with the following early practices: breastfeeding on demand, rooming-in at least 20 hours/day, non-use of formula and pacifier, no test-weighing at each breastfeed. The incidence of sore and cracked nipples and the duration of breastfeeding were not influenced by the use of a nipple ointment. Other interventions, such as providing the mother with guidance and support on positioning and latching, and modifications of hospital practices may be more effective in reducing nipple problems.

  20. The effect of caffeine ingestion on delayed onset muscle soreness.

    PubMed

    Hurley, Caitlin F; Hatfield, Disa L; Riebe, Deborah A

    2013-11-01

    The beneficial effects of caffeine on aerobic activity and resistance training performance are well documented. However, less is known concerning caffeine's potential role in reducing perception of pain and soreness during exercise. In addition, there is no information regarding the effects of caffeine on delayed onset muscle soreness (DOMS). The primary purpose of this study was to examine the effect of caffeine ingestion on muscle soreness, blood enzyme activity, and performance after a bout of elbow flexion/extension exercise. Nine low-caffeine-consuming males (body mass: 76.68 ± 8.13 kg; height: 179.18 ± 9.35 cm; age: 20 ± 1 year) were randomly assigned to ingest either caffeine or placebo 1 hour before completing 4 sets of 10 bicep curls on a preacher bench, followed by a fifth set in which subjects completed as many repetitions as possible. Soreness and soreness on palpation intensity were measured using three 0-10 visual analog scales before exercise, and 24, 48, 72, 96, and 120 hours after exercise. After a washout period, subjects crossed over to the other treatment group. Caffeine ingestion resulted in significantly (p ≤ 0.05) lower levels of soreness on day 2 and day 3 compared with placebo. Total repetitions in the final set of exercise increased with caffeine ingestion compared with placebo. This study demonstrates that caffeine ingestion immediately before an upper-body resistance training out enhances performance. A further beneficial effect of sustained caffeine ingestion in the days after the exercise bout is an attenuation of DOMS. This decreased perception of soreness in the days after a strenuous resistance training workout may allow individuals to increase the number of training sessions in a given time period.

  1. High-pressure soot formation and diffusion flame extinction characteristics of gaseous and liquid fuels

    NASA Astrophysics Data System (ADS)

    Karatas, Ahmet Emre

    High-pressure soot formation and flame stability characteristics were studied experimentally in laminar diffusion flames. For the former, radially resolved soot volume fraction and temperature profiles were measured in axisymmetric co-flow laminar diffusion flames of pre-vaporized n-heptane-air, undiluted ethylene-air, and nitrogen and carbon dioxide diluted ethylene-air at elevated pressures. Abel inversion was used to re-construct radially resolved data from the line-of-sight spectral soot emission measurements. For the latter, flame extinction strain rate was measured in counterflow laminar diffusion flames of C1-4 alcohols and hydrocarbon fuels of n-heptane, n-octane, iso-octane, toluene, Jet-A, and biodiesel. The luminous flame height, as marked by visible soot radiation, of the nitrogen- and helium-diluted n-heptane and nitrogen- and carbon dioxide-diluted ethylene flames stayed constant at all pressures. In pure ethylene flames, flame heights initially increased with pressure, but changed little above 5 atm. The maximum soot yield as a function of pressure in nitrogen-diluted n-heptane diffusion flames indicate that n-heptane flames are slightly more sensitive to pressure than gaseous alkane hydrocarbon flames at least up to 7 atm. Ethylene's maximum soot volume fractions were much higher than those of ethane and n-heptane diluted with nitrogen (fuel to nitrogen mass flow ratio is about 0.5). Pressure dependence of the peak carbon conversion to soot, defined as the percentage of fuel's carbon content converted to soot, was assessed and compared to previous measurements with other gaseous fuels. Maximum soot volume fractions were consistently lower in carbon dioxide-diluted flames between 5 and 15 atm but approached similar values to those in nitrogen-diluted flames at 20 atm. This observation implies that the chemical soot suppression effect of carbon dioxide, previously demonstrated at atmospheric pressure, is also present at elevated pressures up to 15 atm

  2. Soot Formation in Laminar Acetylene/Air Diffusion Flames at Atmospheric Pressure. Appendix H

    NASA Technical Reports Server (NTRS)

    Xu, F.; Faeth, G. M.; Yuan, Z.-G. (Technical Monitor); Urban, D. L. (Technical Monitor); Yuan, Z.-G. (Technical Monitor)

    2001-01-01

    The flame structure and soot-formation (soot nucleation and growth) properties of axisymmetric laminar coflowing jet diffusion flames were studied experimentally. Test conditions involved acetylene-nitrogen jets burning in coflowing air at atmospheric pressure. Measurements were limited to the axes of the flames and included soot concentrations, soot temperatures, soot structure, major gas species concentrations, radical species (H, OH, and O) concentrations, and gas velocities. The results show that as distance increases along the axes of the flames, detectable soot formation begins when significant H concentrations are present, and ends when acetylene concentrations become small. Species potentially associated with soot oxidation-O2, CO2, H2O, O, and OH-are present throughout the soot-formation region so that soot formation and oxidation proceed at the same time. Strong rates of soot growth compared to soot nucleation early in the soot-formation process, combined with increased rates of soot nucleation and oxidation as soot formation proceeds, causes primary soot particle diameters to reach a maximum relatively early in the soot-formation process. Aggregation of primary soot particles proceeds, however, until the final stages of soot oxidation. Present measurements of soot growth (corrected for soot oxidation) in laminar diffusion flames were consistent with earlier measurements of soot growth in laminar premixed flames and exhibited encouraging agreement with existing hydrogen-abstraction/carbon-addition (HACA) soot growth mechanisms in the literature that were developed based on measurements within laminar premixed flames. Measured primary soot particle nucleation rates in the present laminar diffusion flames also were consistent with corresponding rates measured in laminar premixed flames and yielded a crude correlation in terms of acetylene and H concentrations and the temperature.

  3. Soot Formation in Laminar Acetylene/Air Diffusion Flames at Atmospheric Pressure. Appendix J

    NASA Technical Reports Server (NTRS)

    Xu, F.; Faeth, G. M.; Urban, D. L. (Technical Monitor); Yuan, Z.-G. (Technical Monitor)

    2001-01-01

    The flame structure and soot-formation (soot nucleation and growth) properties of axisymmetric laminar coflowing jet diffusion flames were studied experimentally. Test conditions involved acetylene-nitrogen jets burning in coflowing air at atmospheric pressure. Measurements were limited to the axes of the flames and included soot concentrations, soot temperatures, soot structure, major gas species concentrations, radical species (H, OH, and O) concentrations, and gas velocities. The results show that as distance increases along the axes of the flames, detectable soot formation begins when significant H concentrations are present, and ends when acetylene concentrations become small. Species potentially associated with soot oxidation--O2, CO2, H2O, O, and OH-are present throughout the soot-formation region so that soot formation and oxidation proceed at the same time. Strong rates of soot growth compared to soot nucleation early in the soot-formation process, combined with increased rates of soot nucleation and oxidation as soot formation proceeds, causes primary soot particle diameters to reach a maximum relatively early in the soot-formation process. Aggregation of primary soot particles proceeds, however, until the final stages of soot oxidation. Present measurements of soot growth (corrected for soot oxidation) in laminar diffusion flames were consistent with earlier measurements of soot growth in laminar premixed flames and exhibited encouraging agreement with existing hydrogen-abstraction/carbon-addition (HACA) soot growth mechanisms in the literature that were developed based on measurements within laminar premixed flames. Measured primary soot particle nucleation rates in the present laminar diffusion flames also were consistent with corresponding rates measured in laminar premixed flames and yielded a crude correlation in terms of acetylene and H concentrations and the temperature.

  4. Soot Formation in Laminar Acetylene/Air Diffusion Flames at Atmospheric Pressure. Appendix C

    NASA Technical Reports Server (NTRS)

    Xu, F.; Faeth, G. M.; Urban, D. L. (Technical Monitor); Yuan, Z.-G. (Technical Monitor)

    2000-01-01

    The flame structure and soot-formation (soot nucleation and growth) properties of axisymmetric laminar coflowing jet diffusion flames were studied experimentally. Test conditions involved acetylene-nitrogen jets burning in coflowing air at atmospheric pressure. Measurements were limited to the axes of the flames and included soot concentrations, soot temperatures, soot structure, major gas species concentrations, radical species (H, OH, and O) concentrations, and gas velocities. The results show that as distance increases along the axes of the flames, detectable soot formation begins when significant H concentrations are present, and ends when acetylene concentrations become small. Species potentially associated with soot oxidation-O2, CO2, H2O, O, and OH-are present throughout the soot-formation region so that soot formation and oxidation proceed at the same time. Strong rates of soot growth compared to soot nucleation early in the soot-formation process, combined with increased rates of soot nucleation and oxidation as soot formation proceeds, causes primary soot particle diameters to reach a maximum relatively early in the soot-formation process. Aggregation of primary soot particles proceeds, however, until the final stages of soot oxidation. Present measurements of soot growth (corrected for soot oxidation) in laminar diffusion flames were consistent with earlier measurements of soot growth in laminar premixed flames and exhibited encouraging agreement with existing hydrogen-abstraction/carbon-addition (HACA) soot growth mechanisms in the literature that were developed based on measurements within laminar premixed flames. Measured primary soot particle nucleation rates in the present laminar diffusion flames also were consistent with corresponding rates measured in laminar premixed flames and yielded a crude correlation in terms of acetylene and H concentrations and the temperature.

  5. Sore throat following three adult supraglottic airway devices: A randomised controlled trial.

    PubMed

    L'Hermite, Joël; Dubout, Elisabeth; Bouvet, Sophie; Bracoud, Laure-Hélène; Cuvillon, Philippe; Coussaye, Jean-Emmanuel de La; Ripart, Jacques

    2017-07-01

    Sore throat is a common complaint after surgery. It affects patient satisfaction and can affect activity after discharge. The supraglottic airway device (SAD) offers an alternative to traditional tracheal intubation with potential benefit in preventing sore throat. The aim of this study was to compare the incidence of sore throat following three different SADs, the laryngeal mask airway Unique (LMA-U) and the more recent LMA Supreme (LMA-S) and the I-gel. A randomised single-blind controlled three parallel-group trial. University Hospital of Nîmes, Division of Anaesthesia Intensive Care Pain and Emergency, Nîmes, France, from April 2009 to September 2012. A total of 546 patients scheduled to undergo elective surgery of less than 2 h under general anaesthesia were randomly allocated to receive the LMA-U, the LMA-S or the I-gel. Anaesthesia was induced with propofol and sufentanil and maintained with propofol or with sevoflurane in air-oxygen. After airway device insertion, intra-cuff pressure was adjusted to less than 60 mmHg (LMA-U, LMA-S) and pressure-controlled ventilation initiated. The primary study endpoint was to compare incidence of sore throat 24 h postoperatively (H+24) following placement of the LMA-U, LMA-S and the I-gel. Secondary endpoints were clinical performance (airway leak pressure, dynamic airway compliance, complications during maintenance), ease of use (device insertion time, success on first attempt, ease of insertion and removal) and other adverse events (neck or jaw pain, dysphonia, dysphagia, nausea and vomiting). The authors analysed 177, 174 and 173 patients who received LMA-U, the LMA-S and the I-gel, respectively. The primary endpoint was assessed in 436 patients. In total, 104 patients (23.9%) patients reported a H+24 sore throat, with no difference between groups (P = 0.34). H+24 dysphagia with liquids was higher (P = 0.0065) with the LMA-S (12.1%) compared with LMA-U (5.3%) and I-gel (2.9%). Airway leak pressure (cmH2

  6. Formation and properties of water from quartz and hydrogen at high pressure and temperature

    NASA Astrophysics Data System (ADS)

    Futera, Zdenek; Yong, Xue; Pan, Yuanming; Tse, John S.; English, Niall J.

    2017-03-01

    Quartz, as the most stable low-pressure polymorph of silica (SiO2), is widely abundant in Earth's crust and mantle, exhibiting relatively high chemical stability. Although silica is only slightly soluble in water at ambient conditions, producing silicon-based weakly acidic compounds, Shinozaki et al. (2014) have shown recently that water itself can be formed by dissolution of SiO2 in H2 fluid under high- temperature and pressure conditions. Here, we have simulated this process via molecular-dynamics techniques based on a reactive force-field description of the Si O2 /H2 interface. Diffusion of the H2 fluid into the quartz crystal lattice was observed upon increasing temperature and pressure, followed by interaction of dissociated, atomic hydrogen with oxygen atoms in the SiO2 lattice, disrupting the lattice and leading to the formation of water. Interestingly, water is evolved in the subsurface region of the silica, and it remains confined there, isolated from the hydrogen fluid, which corresponds precisely to the ice-like spectroscopic patterns observed experimentally. The over-pressured water formed from quartz and H2 is a possible trigger for nucleating enigmatic deep earthquakes in the continental mantle lithosphere.

  7. Formation of self-consistent pressure profiles in simulation of turbulent convection in tokamak plasmas

    SciTech Connect

    Pastukhov, V. P. Smirnov, D. V.

    2016-04-15

    The formation of pressure profiles in turbulent tokamak plasmas in ohmic heating regimes and transient regimes induced by turning-on of electron-cyclotron resonance (ECR) heating is investigated. The study is based on self-consistent modeling of low-frequency turbulent plasma convection described by an adiabatically reduced set of hydrodynamic-type equations. The simulations show that, in the ohmic heating stage, turbulence forms and maintains profiles of the total plasma pressure corresponding to turbulent relaxed states. These profiles are close to self-consistent profiles of the total plasma pressure experimentally observed on the T-10 tokamak in ohmic regimes with different values of the safety factor q{sub L} at the limiter. Simulations of nonstationary regimes induced by turning-on of on- and off-axis ECR heating show that the total plasma pressure profiles in the transient regimes remain close to those in the turbulent-relaxed state, as well as to the profiles experimentally observed on T-10.

  8. Formation risk of toxic and other unwanted compounds in pressure-assisted thermally processed foods.

    PubMed

    Bravo, K Segovia; Ramírez, R; Durst, R; Escobedo-Avellaneda, Z J; Welti-Chanes, J; Sanz, P D; Torres, J A

    2012-01-01

    Consumers demand, in addition to excellent eating quality, high standards of microbial and chemical safety in shelf-stable foods. This requires improving conventional processing technologies and developing new alternatives such as pressure-assisted thermal processing (PATP). Studies in PATP foods on the kinetics of chemical reactions at temperatures (approximately 100 to 120 °C) inactivating bacterial spores in low-acid foods are severely lacking. This review focuses on a specific chemical safety risk in PATP foods: models predicting if the activation volume value (V(a) ) of a chemical reaction is positive or negative, and indicating if the reaction rate constant will decrease or increase with pressure, respectively, are not available. Therefore, the pressure effect on reactions producing toxic compounds must be determined experimentally. A recent model solution study showed that acrylamide formation, a potential risk in PATP foods, is actually inhibited by pressure (that is, its V(a) value must be positive). This favorable finding was not predictable and still needs to be confirmed in food systems. Similar studies are required for other reactions producing toxic compounds including polycyclic aromatic hydrocarbons, heterocyclic amines, N-nitroso compounds, and hormone like-peptides. Studies on PATP inactivation of prions, and screening methods to detect the presence of other toxicity risks of PATP foods, are also reviewed.

  9. Mixing unmixables: Unexpected formation of Li-Cs alloys at low pressure.

    PubMed

    Desgreniers, Serge; Tse, John S; Matsuoka, Takahiro; Ohishi, Yasuo; Tse, Justin J

    2015-10-01

    Contrary to the empirical Miedema and Hume-Rothery rules and a recent theoretical prediction, we report experimental evidence on the formation of Li-Cs alloys at very low pressure (>0.1 GPa). We also succeeded in synthesizing a pure nonstoichiometric and ordered crystalline phase from an approximately equimolar mixture and resolved its structure using the maximum entropy method. The new alloy has a primitive cubic cell with the Li atom situated in the center and the Cs at the corners. This structure is stable to at least 10 GPa and has an anomalously high coefficient of thermal expansion at low pressure. Analysis of the valence charge density shows that electrons are donated from Cs to the Li "p"-orbitals, resulting in a rare formal oxidation state of -1 for Li. The observation indicates the diversity in the bonding of the seeming simple group I Li element.

  10. Laser-assisted formation of micropores and nanobubbles in sclera promote stable normalization of intraocular pressure

    NASA Astrophysics Data System (ADS)

    Baum, Olga; Wachsmann-Hogiu, Sebastian; Milner, Thomas; Sobol, Emil

    2017-06-01

    Pores in sclera enhance uveoscleral water outflow and can normalize intraocular pressure in glaucomatous eyes. The aims of this study are to demonstrate laser-induced formation of pores with a dendritic structure and to answer the questions: How is a pore system stable and can laser treatment provide a long-lasting pressure stabilization effect? Effect of 1.56 µm laser radiation on porcine eye sclera was studied using atomic force microscopy and super resolution structured irradiation microscopy with fluorescent markers. Results suggest that the pores with a complex spatial configuration can arise as a result of laser irradiation and that laser-generated stable gas nanobubbles coated with calcium ions allow pore stabilization in the sclera. Our results support a laser based approach for treatment of glaucoma.

  11. Formation of carbon nanoparticle using Ar+CH4 high pressure nanosecond discharges

    NASA Astrophysics Data System (ADS)

    Koga, K.; Dong, X.; Iwashita, S.; Czarnetzki, U.; Shiratani, M.

    2014-06-01

    We have studied formation of carbon nanoparticles using Ar+CH4 high pressure nanosecond discharge non-thermal plasmas. Transition pressure from uniform glow discharges to filamentary ones was clarified to obtain conditions under which uniform glow discharges are sustained. We have produced nanoparticles using the glow discharges, and then we have collected nanoparticles on the grounded electrode by the filtered vacuum collection method. Size distribution analysis reveals that the CH4 concentration is an important parameter in controlling nanoparticle growth. We have also studied film deposition on the powered electrode and the grounded electrode. The deposition rate on the powered electrode is 7 times higher than that on the grounded electrode. Optical emission observations suggest that radical generation rate near the powered electrode is twice higher than that near the grounded electrode, leading to high deposition rate on the powered electrode.

  12. Asteroid entry in Venusian atmosphere: Pressure and density fields effect on crater formation

    NASA Technical Reports Server (NTRS)

    Schmidt, Robert

    1995-01-01

    The objectives are to look at time scales of overpressure compared to cratering and to determine: what are the transient pressure and density due to atmospheric entry; do shock waves evacuate ambient gas; do transient atmospheric disturbances 'settle down' during cratering; can the pressure/density field be approximated as quasi-static; how does disturbance scale with impactor size; and what is the role of atmospheric thickness. The general approach is to perform inexpensive exploratory calculations, perform experiments to validate code and observe crater growth, and to follow up with more realistic coupling calculations. This viewgraph presentation presents progress made with the objective to obtain useful scaling relationships for crater formation when atmospheric effects are important.

  13. Formation of the Yakuno ophiolite; accretionary subduction under medium-pressure-type metamorphic conditions

    NASA Astrophysics Data System (ADS)

    Osozawa, Soichi; Takeuchi, Hiroshi; Koitabashi, Toru

    2004-11-01

    The notion that the Yakuno ophiolite and overlying Maizuru Group represents an accretionary prism formed during the Permian evolution of Japan on the Yakuno eruptive sequence, association of hemipelagic mudstone with silicic tuff, exotic fossiliferous limestones derived from previously accreted sea-mounts, upward coarsening of sequences terrigenous sandstone and conglomerate, and mildly deformed Permian and Triassic forearc basin formations. The most important indicator, however, is the seaward imbrication and repetition observed in both the Maizuru Group and the ophiolite itself. D1 deformation structures include axial-planar foliations (pressure-solution cleavage for the Maizuru Group and granulite-amphibolite metamorphic layering in the ophiolite), flattening type strain, symmetric pressure shadows and fringes, and isoclinal folds showing axial-planar foliations and thrust faulting at their overturned limb. The exceptional asymmetry observed indicates seaward-directed shearing near the thrust, while D1 structures in the Maizuru zone are explained by off-scraping, above the basal decollement. The later Jurassic D2 kink fold structure includes a first-order asymmetric kink with a brittle thrust at its overturned limb, more-or-less coeval with M2 retrograde metamorphism. Medium-pressure M1 prograde metamorphism in the Yakuno ophiolite produced layering of granulite and amphibolite, and in the Maizuru Group, formation of illite along pressure-solution cleavage of mudstones. The metamorphic grade is controlled by the stratigraphic relationships and appears typical of that in ocean floor regions. However, there was only one episode of M1 prograde metamorphism which occurred contemporaneously with D1 off-scraping. Given that subduction zones are normally characterized by high P/ T metamorphic regimes, the observed P/ T history appears to reflect relatively unusual conditions. Such high thermal gradients may plausibly reflect the approach of a young, hot oceanic plate

  14. Analog modeling of pressurized subglacial water flow: Implications for tunnel valley formation and ice flow dynamics

    NASA Astrophysics Data System (ADS)

    Lelandais, Thomas; Ravier, Edouard; Mourgues, Régis; Pochat, Stéphane; Strzerzynski, Pierre; Bourgeois, Olivier

    2017-04-01

    Tunnel valleys are elongated and overdeepened depressions up to hundreds of kilometers long, several kilometers wide and hundreds of meters deep, found in formerly glaciated areas. These drainage features are interpreted as the result of subglacial meltwater erosion beneath ice sheets and constitute a major component of the subglacial drainage system. Although tunnel valleys have been described worldwide in the past decades, their formation is still a matter of debate. Here, we present an innovative experimental approach simulating pressurized water flow in a subglacial environment in order to study the erosional processes occurring at the ice-bed interface. We use a sandbox partially covered by a circular, viscous and transparent lid (silicon putty), simulating an impermeable ice cap. Punctual injection of pressurized water in the substratum at the center of the lid simulates meltwater production beneath the ice cap. Surface images collected by six synchronized cameras allow to monitor the evolution of the experiment through time, using photogrammetry methods and DEM generation. UV markers placed in the silicon are used to follow the silicon flow during the drainage of water at the substratum-lid interface, and give the unique opportunity to simultaneously follow the formation of tunnel valleys and the evolution of ice dynamics. When the water pressure is low, groundwater circulates within the substratum only and no drainage landforms appear at the lid-substratum interface. By contrast, when the water pressure exceeds a threshold that is larger than the sum of glaciostatic and lithostatic pressures, additional water circulation occurs at the lid-substratum interface and drainage landforms develop from the lid margin. These landforms share numerous morphological criteria with tunnel valleys such as undulating longitudinal profiles, U-shaped cross-sectional profiles with flat floors, constant widths and abrupt flanks. Continuous generation of DEMs and flow velocity

  15. Equatorial disk formation around rotating stars due to ram pressure confinement by the stellar wind

    NASA Technical Reports Server (NTRS)

    Bjorkman, J. E.; Cassinelli, J. P.

    1993-01-01

    The axisymmetric 2D supersonic solution of a rotating, radiation-driven stellar wind presently obtained by a simple approximation predicts the formation of a dense equatorial disk, when the star's rotation rate lies above a threshold value that depends on the ratio of the wind's terminal speed to the escape speed of the star. The disk is formed because the trajectories of the wind leaving the stellar surface at high latitudes carry it down to the equatorial plane; there, the material passes through a standing oblique shock atop the disk; it is therefore the ram pressure of the polar wind that compresses and confines the disk.

  16. Subnanosecond processes in the stage of breakdown formation in gas at a high pressure

    NASA Astrophysics Data System (ADS)

    Korolev, Yu. D.; Bykov, N. M.; Ivanov, S. N.

    2008-12-01

    Results are presented from experimental studies of the prebreakdown stage of a discharge in nitrogen at pressures of a few tens of atmospheres, gap voltages higher than 140 kV, and a voltage rise time of about 1 ns. Breakdown occurs at the front of the voltage pulse; i.e., the time of breakdown formation is shorter than the front duration. It is shown that, in gaps with a nonuniform electric field, the breakdown formation time is mainly determined by the time of avalanche development to the critical number of charge carriers. The subsequent stages of breakdown (the development of the ionization wave and the buildup of the conductivity in the weakly conducting channel bridging the gap) turn out to be shorter than this time or comparable to it.

  17. The integrated method to select drilling muds for abnormally high pressure formations

    NASA Astrophysics Data System (ADS)

    Khorev, V. S.; Dmitriev, A. Yu; Boyko, I. A.; Kayumova, N. S.; Rakhimov, T. R.

    2016-03-01

    The article describes the method for choosing a drilling mud for drilling abnormally high pressure formations. A carefully selected drilling mud formulation would not only enhance an array of interrelated fluid properties, but also minimize the impact on the pay zones when the drill bit first penetrates the pay. To ensure a better assessment of drilling mud impact on the pay zone, it is reasonable to carry out the study focused on the analysis of technological parameters, involving filtration, acid and drilling mud tests, as well as formation damage analysis. This would enable evaluating the degree of mudding off, reservoirs acid fracturing effect and the risks of pipe sticking at significant depth. The article presents the results of the above-described study with regard to the currently used drilling mud and new experimental formulations developed at National Research Tomsk Polytechnic University (Drilling Mud and Cement Slurry Laboratory).

  18. Self-regulating galaxy formation. Part 1: HII disk and Lyman alpha pressure

    NASA Technical Reports Server (NTRS)

    Cox, D. P.

    1983-01-01

    Assuming a simple but physically based prototype for behavior of interstellar material during formation of a disk galaxy, coupled with the lowest order description of infall, a scenario is developed for self-regulated disk galaxy formation. Radiation pressure, particularly that of Lyman depha (from fluorescence conversion Lyman continuum), is an essential component, maintaining an inflated disk and stopping infall when only a small fraction of the overall perturbation has joined the disk. The resulting galaxies consist of a two dimensional family whose typical scales and surface density are expressable in terms of fundamental constants. The model leads naturally to galaxies with a rich circumgalactic environment and flat rotation curves (but is weak in its analysis of the subsequent evolution of halo material).

  19. Periodic seepage face formation and water pressure distribution along a vertical boundary of an aquifer

    NASA Astrophysics Data System (ADS)

    Jazayeri Shoushtari, Seyed Mohammad Hossein; Nielsen, Peter; Cartwright, Nick; Perrochet, Pierre

    2015-04-01

    Detailed measurements of the piezometric head from sand flume experiments of an idealised coastal aquifer forced by a simple harmonic boundary condition across a vertical boundary are presented. The measurements focus on the pore pressures very close to the interface (x = 0.01m) and throw light on the details of the boundary condition, particularly with respect to meniscus suction and seepage face formation during the falling tide. Between the low and the mean water level, the response is consistent with meniscus suction free models in terms of both the vertical mean head and oscillation amplitude profiles and is consistent with the observation that this area of the interface was generally within the seepage face. Above the mean water level, the influence of meniscus formation is significant with the mean pressure head being less than that predicted by capillary free theory and oscillation amplitudes decaying faster than predicted by suction free models. The reduced hydraulic conductivity in this area due to partial drainage of pores on the falling tide also causes a delay in the response to the rising tide. The combined influence of seepage face formation, meniscus suction and reduced hydraulic conductivity generate higher harmonics with amplitudes of up to 26% of the local main harmonic. To model the influence of seepage face formation and meniscus suction a numerical solution of the Richards' equation was developed and evaluated against the data. The model-data comparison shows a good agreement with the behaviour high above the water table sensitive to the choice of moisture retention parameters.

  20. The effects of massage on delayed onset muscle soreness

    PubMed Central

    Hilbert, J; Sforzo, G; Swensen, T

    2003-01-01

    Objectives: The purpose of this study was to investigate the physiological and psychological effects of massage on delayed onset muscle soreness (DOMS). Methods: Eighteen volunteers were randomly assigned to either a massage or control group. DOMS was induced with six sets of eight maximal eccentric contractions of the right hamstring, which were followed 2 h later by 20 min of massage or sham massage (control). Peak torque and mood were assessed at 2, 6, 24, and 48 h postexercise. Range of motion (ROM) and intensity and unpleasantness of soreness were assessed at 6, 24, and 48 h postexercise. Neutrophil count was assessed at 6 and 24 h postexercise. Results: A two factor ANOVA (treatment v time) with repeated measures on the second factor showed no significant treatment differences for peak torque, ROM, neutrophils, unpleasantness of soreness, and mood (p > 0.05). The intensity of soreness, however, was significantly lower in the massage group relative to the control group at 48 h postexercise (p < 0.05). Conclusions: Massage administered 2 h after exercise induced muscle injury did not improve hamstring function but did reduce the intensity of soreness 48 h after muscle insult. PMID:12547748

  1. Significant Enhancement of H2 Formation in Disk Galaxies under Strong Ram Pressure

    NASA Astrophysics Data System (ADS)

    Henderson, Benjamin; Bekki, Kenji

    2016-05-01

    We show for the first time that H2 formation on dust grains can be enhanced in disk galaxies under strong ram pressure (RP). We numerically investigate how the time evolution of H i and H2 components in disk galaxies orbiting a group/cluster of galaxies can be influenced by the hydrodynamical interaction between the gaseous components of the galaxies and the hot intracluster medium. We find that compression of H i caused by RP increases H2 formation in disk galaxies before RP rapidly strips H i, cutting off the fuel supply and causing a drop in H2 density. We also find that the level of this H2 formation enhancement in a disk galaxy under RP depends on the mass of its host cluster dark matter halo, the initial positions and velocities of the disk galaxy, and the disk inclination angle with respect to the orbital plane. We demonstrate that dust growth is a key factor in the evolution of the H i and H2 mass in disk galaxies under strong RP. We discuss how the correlation between H2 fractions and surface gas densities of disk galaxies evolves with time in the galaxies under RP. We also discuss whether galaxy-wide star formation rates (SFRs) in cluster disk galaxies can be enhanced by RP if the SFRs depend on H2 densities.

  2. The significance of vortex ring formation and nozzle exit over-pressure to pulsatile jet propulsion

    NASA Astrophysics Data System (ADS)

    Krueger, Paul Samuel

    Pulsatile jet propulsion can be accomplished using a fully-pulsed jet (i.e., a periodic series of starting jets or pulses), the unsteady nature of which engenders vortex ring formation. The propulsive significance of vortex ring formation in this setting is studied experimentally using a piston-cylinder mechanism to generate starting and fully-pulsed, round jets of water into water. Starting jets are considered separately since they are the limiting case of a fully-pulsed jet at zero pulsing frequency. Measurements of the total impulse per pulse (starting jets) and time-averaged thrust (fully-pulsed jets) are made using a force balance. Digital particle image velocimetry (DPIV) measurements provide information about the resulting jet flow. Piston stroke to diameter ratios (L/D) between 2 and 8 are used to generate the pulses for both types of jets. This range brackets the transition between pulses that generate isolated vortex rings (small L/D) and pulses that yield a leading vortex ring that has pinched off from the generating jet, producing a trailing jet (large L/D). Impulse measurements for the starting jets as a function of L/D indicate the leading vortex ring adds proportionately more impulse per pulse than a trailing jet. This leads to a maximum in the average thrust during a pulse at an L/D just before vortex ring pinch off is observed. The propulsive advantage of vortex ring formation over trailing-jet ejection is due to nozzle exit over-pressure. This over-pressure can be related to the acceleration of ambient fluid in the form of added and entrained mass during ring formation. A simple model is proposed to describe these effects at the initiation of an impulsive pulse. The thrust measurements for fully-pulsed jets show a propulsive benefit from vortex ring formation (i.e., non-dimensional thrust, FIJ , > 1) for all non-dimensional pulsing frequencies, StL, accessible by a fully-pulsed jet. As with starting jets (StL = 0), vortex ring pinch off reduces

  3. A Computational, Tissue-Realistic Model of Pressure Ulcer Formation in Individuals with Spinal Cord Injury

    PubMed Central

    Ziraldo, Cordelia; Solovyev, Alexey; Allegretti, Ana; Krishnan, Shilpa; Henzel, M. Kristi; Sowa, Gwendolyn A.; Brienza, David; An, Gary; Mi, Qi; Vodovotz, Yoram

    2015-01-01

    People with spinal cord injury (SCI) are predisposed to pressure ulcers (PU). PU remain a significant burden in cost of care and quality of life despite improved mechanistic understanding and advanced interventions. An agent-based model (ABM) of ischemia/reperfusion-induced inflammation and PU (the PUABM) was created, calibrated to serial images of post-SCI PU, and used to investigate potential treatments in silico. Tissue-level features of the PUABM recapitulated visual patterns of ulcer formation in individuals with SCI. These morphological features, along with simulated cell counts and mediator concentrations, suggested that the influence of inflammatory dynamics caused simulations to be committed to “better” vs. “worse” outcomes by 4 days of simulated time and prior to ulcer formation. Sensitivity analysis of model parameters suggested that increasing oxygen availability would reduce PU incidence. Using the PUABM, in silico trials of anti-inflammatory treatments such as corticosteroids and a neutralizing antibody targeted at Damage-Associated Molecular Pattern molecules (DAMPs) suggested that, at best, early application at a sufficiently high dose could attenuate local inflammation and reduce pressure-associated tissue damage, but could not reduce PU incidence. The PUABM thus shows promise as an adjunct for mechanistic understanding, diagnosis, and design of therapies in the setting of PU. PMID:26111346

  4. A Computational, Tissue-Realistic Model of Pressure Ulcer Formation in Individuals with Spinal Cord Injury.

    PubMed

    Ziraldo, Cordelia; Solovyev, Alexey; Allegretti, Ana; Krishnan, Shilpa; Henzel, M Kristi; Sowa, Gwendolyn A; Brienza, David; An, Gary; Mi, Qi; Vodovotz, Yoram

    2015-06-01

    People with spinal cord injury (SCI) are predisposed to pressure ulcers (PU). PU remain a significant burden in cost of care and quality of life despite improved mechanistic understanding and advanced interventions. An agent-based model (ABM) of ischemia/reperfusion-induced inflammation and PU (the PUABM) was created, calibrated to serial images of post-SCI PU, and used to investigate potential treatments in silico. Tissue-level features of the PUABM recapitulated visual patterns of ulcer formation in individuals with SCI. These morphological features, along with simulated cell counts and mediator concentrations, suggested that the influence of inflammatory dynamics caused simulations to be committed to "better" vs. "worse" outcomes by 4 days of simulated time and prior to ulcer formation. Sensitivity analysis of model parameters suggested that increasing oxygen availability would reduce PU incidence. Using the PUABM, in silico trials of anti-inflammatory treatments such as corticosteroids and a neutralizing antibody targeted at Damage-Associated Molecular Pattern molecules (DAMPs) suggested that, at best, early application at a sufficiently high dose could attenuate local inflammation and reduce pressure-associated tissue damage, but could not reduce PU incidence. The PUABM thus shows promise as an adjunct for mechanistic understanding, diagnosis, and design of therapies in the setting of PU.

  5. Preparation of monodisperse microspheres from the Laplace pressure induced droplet formation in micromolds

    NASA Astrophysics Data System (ADS)

    Choi, Chang-Hyung; Kim, Jongmin; Kang, Sung-Min; Lee, Jinkee; Lee, Chang-Soo

    2013-03-01

    Monodisperse microspheres play critical roles in many applications such as micro-electromechanical systems (MEMS), chemical release systems, optical materials and various biological applications. Although microfluidic systems have been developed for producing monodisperse microspheres, it still definitely requires pressure driven flow for continuous fluid injection as well as use of surfactant to achieve their uniformity. Here, we present a novel molding method that generates monodisperse microspheres through surface-tension-induced flow. Two immiscible fluids that consist of photocurable monomer and hydrophobic oil are sequentially applied onto the mold. The mold geometry results in Laplace pressure induced droplet formation, and these droplets formed are individually localized into each micromold. Photopolymerization of the droplets allow for the formation of polymer microspheres with narrow size distribution (CV =1.9%). We obtain the microspheres with diameter ranging from 20 to 300 μm by modulating mold dimensions. We provide a synthesis method to produce microspheres in micromolds for various reaction schemes: UV-polymerization, sol-gel reactions and colloidal assemblies.

  6. High Pressure and Temperature Core Formation as an Alternative to the "Late Veneer" Hypothesis

    NASA Technical Reports Server (NTRS)

    Righter, Kevin; Pando, K.; Humayun, M.; Danielson, L.

    2011-01-01

    The highly siderophile elements (HSE; Re, Au and the Platinum Group Elements - Pd Pt, Rh, Ru, Ir, Os) are commonly utilized to constrain accretion processes in terrestrial differentiated bodies due to their affinity for FeNi metal [1]. These eight elements exhibit highly siderophile behavior, but nonetheless have highly diverse metal-silicate partition coefficients [2]. Therefore the near chondritic relative concentrations of HSEs in the terrestrial and lunar mantles, as well as some other bodies, are attributed to late accretion rather than core formation [1]. Evaluation of competing theories, such as high pressure metal-silicate partitioning or magma ocean hypotheses has been hindered by a lack of relevant partitioning data for this group of eight elements. In particular, systematic studies isolating the effect of one variable (e.g. temperature or melt compositions) are lacking. Here we undertake new experiments on all eight elements, using Fe metal and FeO-bearing silicate melts at fixed pressure, but variable temperatures. These experiments, as well as some additional planned experiments should allow partition coefficients to be more accurately calculated or estimated at the PT conditions and compositions at which core formation is thought to have occurred.

  7. Low-pressure clathrate-hydrate formation in amorphous astrophysical ice analogs

    NASA Technical Reports Server (NTRS)

    Blake, D. F.; Allamandola, L. J.; Sandford, S.; Hudgins, D.; Freund, F.

    1991-01-01

    In modeling cometary ice, the properties of clathrate hydrates were used to explain anomalous gas release at large radial distances from the Sun, and the retention of particular gas inventories at elevated temperatures. Clathrates may also have been important early in solar system history. However, there has never been a reasonable mechanism proposed for clathrate formation under the low pressures typical of these environments. For the first time, it was shown that clathrate hydrates can be formed by warming and annealing amorphous mixed molecular ices at low pressures. The complex microstructures which occur as a result of clathrate formation from the solid state may provide an explanation for a variety of unexplained phenomena. The vacuum and imaging systems of an Hitachi H-500H Analytical Electron Microscope was modified to study mixed molecular ices at temperatures between 12 and 373 K. The resulting ices are characterized by low-electron dose Transmission Electron Microscopy (TEM) and Selected Area Electron Diffraction (SAED). The implications of these results for the mechanical and gas release properties of comets are discussed. Laboratory IR data from similar ices are presented which suggest the possibility of remotely observing and identifying clathrates in astrophysical objects.

  8. Delayed onset muscle soreness and perceived exertion following blood flow restriction exercise.

    PubMed

    Brandner, Christopher R; Warmington, Stuart A

    2017-01-11

    The purpose of this study was to determine the perceptual responses to resistance exercise with either heavy-loads (80% 1 repetition maximum [1-RM]), light-loads (20% 1-RM), or light-loads in combination with blood flow restriction (BFR). Despite the use of light-loads, it has been suggested that the adoption of BFR resistance exercise may be limited due to increases in delayed onset muscle soreness (DOMS) and perceived exertion. Seventeen healthy untrained males participated in this balanced, randomized cross-over study. Following four sets of elbow-flexion exercise, participants reported ratings of perceived exertion (RPE), with DOMS also recorded for seven days following each trial. DOMS was significantly greater for low-pressure continuous BFR (until 48 h post-exercise) and high-pressure intermittent BFR (until 72 h post-exercise) compared with traditional heavy-load and light-load resistance exercise. In addition, RPE was higher for heavy-load resistance exercise and high-pressure intermittent BFR compared with low-pressure continuous BFR, with all trials greater than light-load resistance exercise. For practitioners working with untrained participants, this study provides evidence to suggest that in order to minimize the perception of effort and post-exercise muscle soreness associated with BFR resistance exercise, continuous low-pressure application may be more preferential compared with intermittent high-pressure application. Importantly, these perceptual responses are relatively short-lived (∼2 days) and have previously been shown to subside after a few exercise sessions. Combined with smaller initial training volumes (set x repetitions) this may limit RPE and DOMS to strengthen uptake and adherence, and assist in program progression for muscle hypertrophy and gains in strength.

  9. Coke formation on HFAU and HEMT zeolites. Influence of the reaction temperature and propene pressure

    NASA Astrophysics Data System (ADS)

    Doka Nassionou, G. A.; Magnoux, P.; Guisnet, M.

    1999-02-01

    The formation of coke from propene (Pp = 1.3 kPa and 13 kPa) was investigated on HFAU and HEMT zeolites in a microbalance for temperatures ranging from 120 °C to 450 °C. For both zeolites, the greater the propene pressure and the lower the temperature the faster the initial coke formation. However for high propene pressure, initial coke formation is faster with HEMT zeolite. This can be related to the stronger acidity of the HEMT sample. For low propene pressure and after 420 minutes of coking, a minimum in coke is observed for T = 350 ^circC, which can be related to the difference between the rate of formation and the rate of retention of coke molecules. At low temperature, due to their low volatility, oligomers are easily formed and retained in the zeolite pores. These molecules can be totally eliminated by an adequate thermal treatment in vacuum. At higher temperature, only aromatic or polyaromatic compounds which present a size larger than the pore apertures can be retained in the cavities of the zeolites. The greater the reaction time, the faster the retention. Whatever the reaction temperature, coke molecules are more homogeneously distributed in the HEMT crystallites than in those of HFAU samples. For this latter zeolite coke molecules are preferentially formed in the cavities located near the outer surface of the crystallites (shell coking). La formation de coke à partir du propène (Pp = 1,3 et 13 kPa) a été étudiée en microbalance sur zéolithes HFAU et HEMT dans une gamme de température variant de 120 à 450°C. La vitesse initiale de formation de coke dépend de la pression du propène, de la température et également de la zéolithe. Ainsi, pour une forte pression en propène, la vitesse initiale de formation de coke est toujours plus importante sur HEMT que sur HFAU. Ceci est à relier à la plus grande acidité et à la présence de sites acides plus forts sur HEMT. Après 420 minutes de réaction, et pour une faible pression en propène le

  10. [The contribution of telemedicine in the management of pressure ulcers in palliative care].

    PubMed

    Barateau, Martine; Salles, Nathaue

    2015-01-01

    The use of telemedicine in the treatment of pressure sores in palliative care. The benefit of telemedicine in nursing homes has been demonstrated notably in the case of pressure sores. It gives health professionals the possibility to establish valuable exchanges. A real support and trainingtool, it enables them to improve their skills and share good practices across geriatrics.

  11. The collaborative effect of ram pressure and merging on star formation and stripping fraction

    NASA Astrophysics Data System (ADS)

    Bischko, J. C.; Steinhauser, D.; Schindler, S.

    2015-04-01

    Aims: We investigate the effect of ram pressure stripping (RPS) on several simulations of merging pairs of gas-rich spiral galaxies. We are concerned with the changes in stripping efficiency and the time evolution of the star formation rate. Our goal is to provide an estimate of the combined effect of merging and RPS compared to the influence of the individual processes. Methods: We make use of the combined N-body/hydrodynamic code GADGET-2. The code features a threshold-based statistical recipe for star formation, as well as radiative cooling and modeling of galactic winds. In our simulations, we vary mass ratios between 1:4 and 1:8 in a binary merger. We sample different geometric configurations of the merging systems (edge-on and face-on mergers, different impact parameters). Furthermore, we vary the properties of the intracluster medium (ICM) in rough steps: the speed of the merging system relative to the ICM between 500 and 1000 km s-1, the ICM density between 10-29 and 10-27 g cm-3, and the ICM direction relative to the mergers' orbital plane. Ram pressure is kept constant within a simulation time period, as is the ICM temperature of 107 K. Each simulation in the ICM is compared to simulations of the merger in vacuum and the non-merging galaxies with acting ram pressure. Results: Averaged over the simulation time (1 Gyr) the merging pairs show a negligible 5% enhancement in SFR, when compared to single galaxies under the same environmental conditions. The SFRs peak at the time of the galaxies first fly-through. There, our simulations show SFRs of up to 20 M⊙ yr-1 (compared to 3 M⊙ yr-1 of the non-merging galaxies in vacuum). In the most extreme case, this constitutes a short-term (<50 Myr) SFR increase of 50 % over the non-merging galaxies experiencing ram pressure. The wake of merging galaxies in the ICM typically has a third to half the star mass seen in the non-merging galaxies and 5% to 10% less gas mass. The joint effect of RPS and merging, according

  12. Effect of thermal shrinkage during thermoforming on the thickness of fabricated mouthguards: Part 2 pressure formation.

    PubMed

    Takahashi, Mutsumi; Satoh, Yoshihide; Iwasaki, Shin-Ichi

    2017-04-01

    The aim of this study was to examine the effect of thermal shrinkage, which occurs during thermoforming of ethylene vinyl acetate (EVA) sheets on the thickness of mouthguards fabricated by pressure formation. Mouthguards were fabricated from 4.0-mm-thick EVA sheets by utilizing a pressure-forming machine. Two molding conditions were compared: The sheets were placed in the thermoforming machine with the sheet extrusion direction either vertical or parallel to the model's center line. The working model was trimmed to the height of 20 mm at the cutting edge of the maxillary central incisor and 15 mm at the mesiobuccal cusp of the maxillary first molar. The sheet was pressed against the working model for 2 min where the center of the softened sheet sagged 15 mm lower than the clamp. After fabrication, the thickness of mouthguard sheets was determined for the incisal (incisal edge and labial surface) and molar (cusp and buccal surface) portions, and dimensional measurements were made. Differences in molded mouthguard thickness with the sheet orientation of extruded sheets were analyzed by Mann-Whitney U-test. In comparison with the parallel axis orientation, the sheets in vertical orientation with the model's centerline yielded significantly higher thickness measurements at the incisal edge, labial surface, and the cusp (P < 0.01, respectively). The results suggest that the EVA sheet produced by extrusion molding in vertical axis orientation with the model's centerline can effectively reduce loss of thickness in mouthguards after pressure formation. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. The Pegasus Overture alternating-pressure mattress overlay.

    PubMed

    Fox, C

    Pressure sores affect approximately 10% of the adult population and occur in various hospitals and community settings (Department of Health, 1992). It is therefore essential to adopt a logical approach when selecting the optimum piece of equipment for patients at risk of pressure sore development. Alternating-pressure mattresses have been used for many years in both hospitals and community environments to prevent and treat pressure sores. In September 1995, Pegasus Airwave Limited launched a new alternating-pressure mattress overlay, the Overture. It is designed for use with patients who have mobility problems and are at low to medium risk of developing pressure sores or have superficial tissue damage. This article describes the features of the Overture and its suitability for use in different care settings.

  14. Post-Intubation Sore Throat and Menstruation Cycles

    PubMed Central

    Orandi, Amirali; Orandi, Amirhossein; Najafi, Atabak; Hajimohammadi, Fatemeh; Soleimani, Sara; Zahabi, Somayeh

    2013-01-01

    Background Postoperative sore throat is one of the most common complications of general anesthesia and intubation with prevalence of 18%-65% in different studies. Several risk factors including female gender, postoperative nausea and vomiting and so on have been mentioned. Objectives The aim of this study was to evaluate the incidence of postoperative sore throat in females and its association with menstrual cycles. Patients and Methods One hundred females between 18-45 years old with ASA class I or II without predicted difficult airway that were candidate for operation in supine position were enrolled in study. Patients who had pulmonary disease, smoking, common cold within two weeks prior to the operation, previous traumatic intubation history, removable dentures, any congenital or acquired deformity in face, neck, mouth and airway, any known pathology in mouth like aphthous and mouth ulcer,pregnant women, and patients with irregular cycles, and those taking oral contraceptive pills were excluded. By the same protocol general anesthesia was provided and the patients were asked to fill out a three-point scale questionnaire (Low, High, None) 1,6 and 24 hours following intubation to study and record the incidence and severity of sore throat, dysphagia and hoarseness. The date of last menstrual period had been recorded as well. Results Of 100 patients, in the first six hours, 51 patients had sore throat and 49 had no pain. During the first 6 hours, 33 patients (33%) had dysphagia and 13 patients had hoarseness at 6th postoperative hour. Age, weight, LMP, intubation time, operation and extubation time and coughing were compared to sore throat, dysphagia and hoarseness. The association between the incidence of coughing and bucking and sore throat was significant (P = 0.03). None of the parameters had a statistically meaningful association with dysphagia. Conclusions According to our results, by omitting probable risk factors of incidence of sore throat and evaluation

  15. Salt stress induces the formation of a novel type of 'pressure wood' in two Populus species.

    PubMed

    Janz, Dennis; Lautner, Silke; Wildhagen, Henning; Behnke, Katja; Schnitzler, Jörg-Peter; Rennenberg, Heinz; Fromm, Jörg; Polle, Andrea

    2012-04-01

    • Salinity causes osmotic stress and limits biomass production of plants. The goal of this study was to investigate mechanisms underlying hydraulic adaptation to salinity. • Anatomical, ecophysiological and transcriptional responses to salinity were investigated in the xylem of a salt-sensitive (Populus × canescens) and a salt-tolerant species (Populus euphratica). • Moderate salt stress, which suppressed but did not abolish photosynthesis and radial growth in P. × canescens, resulted in hydraulic adaptation by increased vessel frequencies and decreased vessel lumina. Transcript abundances of a suite of genes (FLA, COB-like, BAM, XET, etc.) previously shown to be activated during tension wood formation, were collectively suppressed in developing xylem, whereas those for stress and defense-related genes increased. A subset of cell wall-related genes was also suppressed in salt-exposed P. euphratica, although this species largely excluded sodium and showed no anatomical alterations. Salt exposure influenced cell wall composition involving increases in the lignin : carbohydrate ratio in both species. • In conclusion, hydraulic stress adaptation involves cell wall modifications reciprocal to tension wood formation that result in the formation of a novel type of reaction wood in upright stems named 'pressure wood'. Our data suggest that transcriptional co-regulation of a core set of genes determines reaction wood composition.

  16. Ozone kinetics in low-pressure discharges: vibrationally excited ozone and molecule formation on surfaces

    NASA Astrophysics Data System (ADS)

    Marinov, Daniil; Guerra, Vasco; Guaitella, Olivier; Booth, Jean-Paul; Rousseau, Antoine

    2013-10-01

    A combined experimental and modeling investigation of the ozone kinetics in the afterglow of pulsed direct current discharges in oxygen is carried out. The discharge is generated in a cylindrical silica tube of radius 1 cm, with short pulse durations between 0.5 and 2 ms, pressures in the range 1-5 Torr and discharge currents ˜40-120 mA. Time-resolved absolute concentrations of ground-state atoms and ozone molecules were measured simultaneously in situ, by two-photon absorption laser-induced fluorescence and ultraviolet absorption, respectively. The experiments were complemented by a self-consistent model developed to interpret the results and, in particular, to evaluate the roles of vibrationally excited ozone and of ozone formation on surfaces. It is found that vibrationally excited ozone, O_3^{*} , plays an important role in the ozone kinetics, leading to a decrease in the ozone concentration and an increase in its formation time. In turn, the kinetics of O_3^{*} is strongly coupled with those of atomic oxygen and O2(a 1Δg) metastables. Ozone formation at the wall does not contribute significantly to the total ozone production under the present conditions. Upper limits for the effective heterogeneous recombination probability of O atoms into ozone are established.

  17. Volume and expansivity changes of micelle formation measured by pressure perturbation calorimetry.

    PubMed

    Fan, Helen Y; Nazari, Mozhgan; Chowdhury, Saria; Heerklotz, Heiko

    2011-03-01

    We present the application of pressure perturbation calorimetry (PPC) as a new method for the volumetric characterization of the micelle formation of surfactants. The evaluation is realized by a global fit of PPC curves at different surfactant concentration ranging, if possible, from below to far above the CMC. It is based on the knowledge of the temperature dependence of the CMC, which can for example be characterized by isothermal titration calorimetry. We demonstrate the new approach for decyl-β-maltopyranoside (DM). It shows a strong volume increase upon micelle formation of 16 ± 2.5 mL/mol (+4%) at 25 °C, and changes with temperature by -0.1 mL/(mol K). The apparent molar expansivity (E(S)) decreases upon micelle formation from 0.44 to 0.31 mL/(mol K) at 25 °C. Surprisingly, the temperature dependence of the expansivity of DM in solution (as compared with that of maltose) does not agree with the principal behavior described for polar (E(S)(T) decreasing) and hydrophobic (E(S)(T) increasing) solutes or moieties before. The results are discussed in terms of changes in hydration of the molecules and internal packing of the micelles and compared with the volumetric effects of transitions of proteins, DNA, lipids, and polymers.

  18. Isotope mass balances in deep formations: How to consider the influence of pressure, temperature and salinity

    NASA Astrophysics Data System (ADS)

    Becker, Veith; Myrttinen, Anssi; Barth, Johannes A. C.

    2010-05-01

    Stable carbon isotopes are a sensitive tool to trace migration and to quantify mixing of CO2 from different sources. This technique is well described for application at the surface and under close-to-surface conditions. However, in order to use isotope mass balances when monitoring the fate of CO2 at carbon storage sites, some distinctive characteristics of deep formations have to be considered. High pressures (from 30 to 200 bar), temperatures (up to over 120 ° C) and salinities (approx. 100 to 400 g/L) influence the carbonate equilibrium as activities, fugacities and the stoichiometric equilibrium constants (fCO2, Kcalcite*, K1*, K2*) change with these parameters. Furthermore, isotopic fractionation is also affected by these parameters. Various relations are published, describing these dependencies with approaches of different complexity and exactness. In this field of application, available sampling data is usually limited, so that averaging and interpolation of input data may lead to noticeable error ranges. Under these conditions, the most elaborated algorithms do not necessarily perform better than more simple ones with respect to the overall error of the calculations. This work therefore compares the available approaches to describe temperature, pressure and salinity dependence in carbonate equilibrium calculations, as well as carbon isotope fractionation in this process with respect to the best ratio of accuracy in carbon storage site monitoring applications. It stands out that the fugacity and the stoichiometric constants involved in DIC-speciation are heavily influenced by pressure, temperature and salinity in general, whereas the individual composition of the solution may be simplified, at least for NaCl-type brines. With respect to fractionation, temperature plays a key role; pressure and salinity variations contribute to the species distribution only to a small amount. This study was conducted as a part of the R&D programme CLEAN, which is funded by

  19. Sphingosine kinase functionally links elevated transmural pressure and increased reactive oxygen species formation in resistance arteries.

    PubMed

    Keller, Matthias; Lidington, Darcy; Vogel, Lukas; Peter, Bernhard Friedrich; Sohn, Hae-Young; Pagano, Patrick J; Pitson, Stuart; Spiegel, Sarah; Pohl, Ulrich; Bolz, Steffen-Sebastian

    2006-04-01

    Myogenic vasoconstriction, an intrinsic response to elevated transmural pressure (TMP), requires the activation of sphingosine kinase (Sk1) and the generation of reactive oxygen species (ROS). We hypothesized that pressure-induced Sk1 signaling and ROS generation are functionally linked. Using a model of cannulated resistance arteries isolated from the hamster gracilis muscle, we monitored vessel diameter and smooth muscle cell (SMC) Ca2+i (Fura-2) or ROS production (dichlorodihydrofluorescein). Elevation of TMP stimulated the translocation of a GFP-tagged Sk1 fusion protein from the cytosol to the plasma membrane, indicative of enzymatic activation. Concurrently, elevation of TMP initiated a rapid and transient production of ROS, which was enhanced by expression of wild-type Sk1 (hSk(wt)) and inhibited by its dominant-negative mutant (hSk(G82D)). Exogenous sphingosine-1-phosphate (S1P) also stimulated ROS generation is isolated vessels. Chemical (1 micromol/L DPI), peptide (gp91ds-tat/gp91ds), and genetic (N17Rac) inhibition strategies indicated that NADPH oxidase was the source of the pressure-induced ROS. NADPH oxidase inhibition attenuated myogenic vasoconstriction and reduced the apparent Ca2+ sensitivity of the SMC contractile apparatus, without affecting Ca2+-independent, RhoA-mediated vasoconstriction in response to exogenous S1P. Our results indicate a mandatory role for Sk1/S1P in mediating pressure-induced, NADPH oxidase-derived ROS formation. In turn, ROS generation appears to increase Ca2+ sensitivity, necessary for full myogenic vasoconstriction.

  20. School Nurses on the Front Lines of Medicine: A Student With Fever and Sore Throat.

    PubMed

    Olympia, Robert P

    2016-05-01

    Fever and sore throat are common chief complaints encountered by school nurses. This article explains the etiology of both fever and sore throat in children, describes the office assessment, and delineates life-threatening complications associated with fever and sore throat that may prompt the school nurse to transfer the child to a local emergency department. © 2016 The Author(s).

  1. THE RELATION OF EXERCISE TO BUBBLE FORMATION IN ANIMALS DECOMPRESSED TO SEA LEVEL FROM HIGH BAROMETRIC PRESSURES.

    PubMed

    Harris, M; Berg, W E; Whitaker, D M; Twitty, V C

    1945-01-20

    1. Bullfrogs (Rana catesbiana) and rats have been subjected to high barometric pressures and studied for bubble formation on subsequent decompression to sea level. Pressures varying from 3 to 60 pounds per square inch, in excess of atmospheric pressure, were used. 2. Muscular activity after decompression is necessary for bubble formation in bullfrogs after pressure treatment throughout the above range. Anesthetized frogs remained bubble-free following decompression. Rats compressed at 15 to 45 pounds per square inch likewise did not contain bubbles unless exercised on return to sea level. 3. Bubbles form without voluntary muscular activity in anesthetized rats previously subjected to pressure of 60 pounds per square inch. Small movements involved in breathing and other vital activities are believed sufficient to initiate bubbles in the presence of very high supersaturations of N(2). 4. Bubbles appear (with exercise) in rats previously compressed at 15 pounds per square inch, and in bullfrogs subjected to pressure at levels as low as 3 pounds per square inch above atmospheric pressure. The percentage drop in pressure necessary for bubble formation is less in compressed animals than in those decompressed from sea level to simulated altitudes. 5. The action of exercise on bubble formation in compressed frogs and rats is attributed to mechanical factors associated with muscular activity, combined with the high supersaturation of N(2). CO(2) probably is not greatly involved, since its concentration does not reach supersatuation, as it does at high altitude. 6. Anoxia following decompression from high barometric pressures has no observable facilitating effect on bubble formation.

  2. Topical negative pressure therapy: current concepts and practice.

    PubMed

    Malahias, M; Hindocha, S; Saedi, F; McArthur, P

    2012-10-01

    Research into topical negative pressure therapy (TNPT) started in 1989 with Dr Louis Argenta and Prof Michael Morykwas of Wake Forest University School of Medicine in North Carolina, USA. In 1997, Morykwas and Argenta concluded that TNPT both enhanced granulation tissue formation and helped bacterial clearance, through the actions of negative pressure Armstrong and Lavery confirmed this in 2005, concluding that TNPT therapy was promoting the development of granulation tissue. Numerous other studies have proved that TNPT is beneficial for a myriad of other wounds including: sternotomy wounds, extensive de-gloving injuries, various soft tissue injuries prior to surgical closure, skin grafting, pressure sores, leg ulcers, sacral pressure ulcers, acute traumatic soft tissue defects, and soft tissue defects following rigid stabilisation of lower extremity fractures. This review aims to summarise the clinical and scientific concepts of TNPT and its future applications.

  3. Bromate formation from the oxidation of bromide in the UV/chlorine process with low pressure and medium pressure UV lamps.

    PubMed

    Fang, Jingyun; Zhao, Quan; Fan, Chihhao; Shang, Chii; Fu, Yun; Zhang, Xiangru

    2017-09-01

    When a bromide-containing water is treated by the ultraviolet (UV)/chlorine process, hydroxyl radicals (HO) and halogen radicals such as Cl or Br are formed due to the UV photolysis of free halogens. These reactive species may induce the formation of bromate, which is a probable human carcinogen. Bromate formation in the UV/chlorine process using low pressure (LP) and medium pressure (MP) lamps in the presence of bromide was investigated in the present study. The UV/chlorine process significantly enhanced bromate formation as compared to dark chlorination. The bromate formation was elevated with increasing UV fluence, bromide concentration, and pH values under both LP and MP UV irradiations. It was significantly enhanced at pH 9 compared to those at pH 6 and 7 with MP UV irradiation, while it was slightly enhanced at pH 9 with LP UV. The formation by UV/chlorine process started with the formation of free bromine (HOBr/OBr(-)) through the reaction of chlorine and bromide, followed by a subsequent oxidation of free bromine and formation of BrO and bromate by reacting with radicals. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Exploring old and new benzene formation pathways in low-pressure premixed flames of aliphatic fuels

    SciTech Connect

    Christopher J. Pope; James A. Miller

    2000-12-13

    A modeling study of benzene and phenyl radical formation is performed for three low-pressure premixed laminar flat flames having an unsaturated C{sub 2} or C{sub 3} hydrocarbon fuel (acetylene, ethylene, and propene). Predictions using three published detailed elementary-step chemical kinetics mechanisms are tested against MBMS species profile data for all three flames. The differences between the three mechanisms predictive capabilities are explored, with an emphasis on benzene formation pathways. A new chemical kinetics mechanism is created combining features of all three published mechanisms. Included in the mechanism are several novel benzene formation reactions involving combinations of radicals such as C{sub 2}H+C{sub 4}H{sub 5}, and C{sub 5}H{sub 3}+CH{sub 3}. Reactions forming fulvene (a benzene isomer) are included, such as C{sub 3}H{sub 3}+C{sub 3}H{sub 5},as well as fulvene-to-benzene reactions. Predictions using the new mechanism show virtually all of the benzene and phenyl radical to be formed by reactions of either C{sub 3}H{sub 3}+C{sub 3}H{sub 3} or C{sub 3}H{sub 3}+C{sub 3}H{sub 5}, with the relative importance being strongly dependent upon the fuel. C{sub 5}H{sub 3}+CH{sub 3} plays a minor role in fulvene formation in the acetylene flame. The C{sub 2}H{sub x}+C{sub 4}H{sub 4} reactions do not contribute noticeably to benzene or phenyl radical formation in these flames, sometimes being a major decomposition channel for either fulvene or phenyl radical. The formation pathways for C{sub 3}H{sub 3} and C{sub 3}H{sub 5}are delineated for the three flames; while the key reactions differ from flame to flame, CH{sub 2}+C{sub 2}H{sub 2} {Longleftrightarrow} C{sub 3}H{sub 3}+H is important for all three flames.

  5. Effect of pressure on structure and NO sub X formation in CO-air diffusion flames

    NASA Technical Reports Server (NTRS)

    Maahs, H. G.; Miller, I. M.

    1979-01-01

    A study was made of nitric oxide formation in a laminar CO-air diffusion flame over a pressure range from 1 to 50 atm. The carbon monoxide (CO) issued from a 3.06 mm diameter port coaxially into a coflowing stream of air confined within a 20.5 mm diameter chimney. Nitric oxide concentrations from the flame were measured at two carbon monoxide (fuel) flow rates: 73 standard cubic/min and 146 sccm. Comparison of the present data with data in the literature for a methane-air diffusion flame shows that for flames of comparable flame height (8 to 10 mm) and pseudoequivalence ratio (0.162), the molar emission index of a CO-air flame is significantly greater than that of a methane-air flame.

  6. Hemispheric Asymmetry and Pun Comprehension: When Cowboys Have Sore Calves

    ERIC Educational Resources Information Center

    Coulson, Seana; Severens, Els

    2007-01-01

    Event-related potentials (ERPs) were recorded as healthy participants listened to puns such as ''During branding, cowboys have sore calves.'' To assess hemispheric differences in pun comprehension, visually presented probes that were either highly related (COW), moderately related (LEG), or unrelated, were presented in either the left or right…

  7. Recommendations for the Avoidance of Delayed-Onset Muscle Soreness.

    ERIC Educational Resources Information Center

    Szymanski, David J.

    2001-01-01

    Describes the possible causes of delayed-onset muscle soreness (DOMS), which include buildup of lactic acid in muscle, increased intracellular calcium concentration, increased intramuscular inflammation, and muscle fiber and connective tissue damage. Proposed methods to reduce DOMS include warming up before exercise and performing repeated bouts…

  8. Recommendations for the Avoidance of Delayed-Onset Muscle Soreness.

    ERIC Educational Resources Information Center

    Szymanski, David J.

    2001-01-01

    Describes the possible causes of delayed-onset muscle soreness (DOMS), which include buildup of lactic acid in muscle, increased intracellular calcium concentration, increased intramuscular inflammation, and muscle fiber and connective tissue damage. Proposed methods to reduce DOMS include warming up before exercise and performing repeated bouts…

  9. Hemispheric Asymmetry and Pun Comprehension: When Cowboys Have Sore Calves

    ERIC Educational Resources Information Center

    Coulson, Seana; Severens, Els

    2007-01-01

    Event-related potentials (ERPs) were recorded as healthy participants listened to puns such as ''During branding, cowboys have sore calves.'' To assess hemispheric differences in pun comprehension, visually presented probes that were either highly related (COW), moderately related (LEG), or unrelated, were presented in either the left or right…

  10. The effects of three modalities on delayed onset muscle soreness.

    PubMed

    Weber, M D; Servedio, F J; Woodall, W R

    1994-11-01

    Delayed onset muscle soreness is a common problem that can interfere with rehabilitation as well as activities of daily living. The purpose of this study was to test the impact of therapeutic massage, upper body ergometry, or microcurrent electrical stimulation on muscle soreness and force deficits evident following a high-intensity eccentric exercise bout. Forty untrained, volunteer female subjects were randomly assigned to one of three treatment groups or to a control group. Exercise consisted of high-intensity eccentric contractions of the elbow flexors. Resistance was reduced as subjects fatigued, until they reached exhaustion. Soreness rating was determined using a visual analog scale. Force deficits were determined by measures of maximal voluntary isometric contraction at 90 degrees of elbow flexion and peak torque for elbow flexion at 60 degrees/sec on a Cybex II isokinetic dynamometer. Maximal voluntary isometric contraction and peak torque were determined at the 0 hour (before exercise) and again at 24 and 48 hours postexercise. Treatments were applied immediately following exercise and again at 24 hours after exercise. The control group subjects rested following their exercise bout. Statistical analysis showed significant increases in soreness rating and significant decreases in force generated when the 0 hour was compared with 24- and 48-hour measures. Further analysis indicated no statistically significant differences between massage, microcurrent electrical stimulation, upper body ergometry, and control groups.

  11. Detection of carbon dioxide leakage during injection in deep saline formations by pressure tomography

    NASA Astrophysics Data System (ADS)

    Hu, Linwei; Bayer, Peter; Brauchler, Ralf

    2016-07-01

    CO2 injected into storage formations may escape to the overlying permeable layers. Mixed-phase diffusivity, namely the ratio of hydraulic conductivity and specific storage of the phase mixture, declines with increasing CO2 saturation. Thus, it can be an indicator of CO2 leakage. In this study, we perform interference brine or CO2 injection tests in a synthetic model, including a storage reservoir, an above aquifer, and a caprock. Pressure transients derived from an observation well are utilized for a travel-time based inversion technique. Variations of diffusivity are resolved by inverting early travel time diagnostics, providing an insight of plume development. Results demonstrate that the evolution of CO2 leakage in the above aquifer can be inferred by interpreting and comparing the pressure observations, travel times, and diffusivity tomograms from different times. The extent of the plume in reservoir and upper aquifer are reconstructed by clustering the time-lapse data sets of the mixed-phase diffusivity, as the diffusivity cannot be exactly reproduced by the inversion. Furthermore, this approach can be used to address different leaky cases, especially for leakage occurring during the injection.

  12. The Relative Importance of Aqueous vs. Vapor-Pressure Dependent Pathways for Particulate Organic Nitrate Formation

    NASA Astrophysics Data System (ADS)

    Zare, A.; Pye, H. O. T.; Cohen, R. C.

    2016-12-01

    Formation of biogenic derived organic nitrates is known as an important immediate sink of atmospheric nitrogen oxides. Although, subsequent oxidation and photolysis of organic nitrates can return a part of the sequestered NOx to the atmosphere, other removal pathways in combination with wet and dry deposition and hydrolysis of particulate organic nitrates is of central importance in irreversible NOx removal from the atmosphere. The aim of this work is to understand how and to what degree the particle phase participates in removal of NOx. We implement a new BVOC oxidation gas phase mechanism (including a detailed representation of OH- and NO3-initiated organic nitrates) and an explicit representation of organic nitrate aerosols formation, including irreversible aqueous-phase uptake and reversible partitioning onto pre-existing organic aerosol, into the CMAQ model. Using these mechanisms, we simulate observations from the SOAS field campaigns over the southeast US in summer 2013 and examine the relative role of water-mediated vs vapor pressure processes in determining aerosol from organic nitrates.

  13. Soot Formation in Laminar Premixed Methane/Oxygen Flames at Atmospheric Pressure. Appendix H

    NASA Technical Reports Server (NTRS)

    Xu, F.; Lin, K.-C.; Faeth, G. M.; Urban, D. L. (Technical Monitor); Yuan, Z.-G. (Technical Monitor)

    2001-01-01

    Flame structure and soot formation were studied within soot-containing laminar premixed methanefoxygen flames at atmospheric pressure. The following measurements were made: soot volume fractions by laser extinction, soot temperatures by multiline emission, gas temperatures (where soot was absent) by corrected fine-wire thermocouples, soot structure by thermophoretic sampling and transmission electron microscope (TEM), major gas species concentrations by sampling and gas chromatography, and gas velocities by laser velocimetry. Present measurements of gas species concentrations were in reasonably good agreement with earlier measurements due to Ramer et al. as well as predictions based on the detailed mechanisms of Frenklach and co-workers and Leung and Lindstedt; the predictions also suggest that H atom concentrations are in local thermodynamic equilibrium throughout the soot formation region. Using this information, it was found that measured soot surface growth rates could be correlated successfully by predictions based on the hydrogenabstraction/carbon-addition (HACA) mechanisms of both Frenklach and co-workers and Colket and Hall, extending an earlier assessment of these mechanisms for premixed ethylene/air flames to conditions having larger H/C ratios and acetylene concentrations. Measured primary soot particle nucleation rates were somewhat lower than the earlier observations for laminar premixed ethylene/air flames and were significantly lower than corresponding rates in laminar diffusion flames, for reasons that still must be explained.

  14. Soot Formation in Laminar Premixed Methane/Oxygen Flames at Atmospheric Pressure

    NASA Technical Reports Server (NTRS)

    Xu, F.; Lin, K.-C.; Faeth, G. M.

    1998-01-01

    Flame structure and soot formation were studied within soot-containing laminar premixed mc1hane/oxygen flames at atmospheric pressure. The following measurements were made: soot volume fractions by laser extinction, soot temperatures by multiline emission, gas temperatures (where soot was absent) by corrected fine-wire thermocouples, soot structure by thermophoretic sampling and transmission electron microscope (TEM), major gas species concentrations by sampling and gas chromatography, and gas velocities by laser velocimetry. Present measurements of gas species concentrations were in reasonably good agreement with earlier measurements due to Ramer et al. as well as predictions based on the detailed mechanisms of Frenklach and co-workers and Leung and Lindstedt: the predictions also suggest that H atom concentrations are in local thermodynamic equilibrium throughout the soot formation region. Using this information, it was found that measured soot surface growth rates could be correlated successfully by predictions based on the hydrogen-abstraction/carbon-addition (HACA) mechanisms of both Frenklach and co-workers and Colket and Hall, extending an earlier assessment of these mechanisms for premixed ethylene/air flames to conditions having larger H/C ratios and acetylene concentrations. Measured primary soot particle nucleation rates were somewhat lower than the earlier observations for laminar premixed ethylene/air flames and were significantly lower than corresponding rates in laminar diffusion flames. for reasons that still must be explained.

  15. Soot formation and temperature structure in small methane-oxygen diffusion flames at subcritical and supercritical pressures

    SciTech Connect

    Joo, Hyun I.; Guelder, Oemer L.

    2010-06-15

    An experimental study was conducted to examine the characteristics of laminar methane-oxygen diffusion flames up to 100 atmospheres. The influence of pressure on soot formation and on the structure of the temperature field was investigated over the pressure range of 10-90 atmospheres in a high-pressure combustion chamber using a non-intrusive, line-of-sight spectral soot emission diagnostic technique. Two distinct zones characterized the appearance of a methane and pure oxygen diffusion flame: an inner luminous zone similar to the methane-air diffusion flames, and an outer diffusion flame zone which is mostly blue. The flame height, marked by the visible soot radiation emission, was reduced by over 50% over the pressure range of 10-100 atmospheres. Between 10 and 40 atmospheres, the soot levels increased with increasing pressure; however, above 40 atmospheres the soot concentrations decreased with increasing pressure. (author)

  16. Reducing Mechanical Formation Damage by Minimizing Interfacial Tension and Capillary Pressure in Tight Gas

    NASA Astrophysics Data System (ADS)

    Ahmed, Arshad; Talib Shuker, Muhannad; Rehman, Khalil; Bahrami, Hassan; Memon, Muhammad Khan

    2013-12-01

    Tight gas reservoirs incur problems and significant damage caused by low permeability during drilling, completion, stimulation and production. They require advanced improvement techniques to achieve flow gas at optimum rates. Water blocking damage (phase Trapping/retention of fluids) is a form of mechanical formation damage mechanism, which is caused by filtrate invasion in drilling operations mostly in fracturing. Water blocking has a noticeable impact on formation damage in gas reservoirs which tends to decrease relative permeability near the wellbore. Proper evaluation of damage and the factors which influence its severity is essential to optimize well productivity. Reliable data regarding interfacial tension between gas and water is required in order to minimize mechanical formation damage potential and to optimize gas production. This study was based on the laboratory experiments of interfacial tension by rising drop method between gas-brine, gas-condensate and gas-brine. The results showed gas condensate has low interfacial tension value 6 - 11 dynes/cm when compared to gas-brine and gas- diesel which were 44 - 58 dynes/cm and 14 - 19 dynes/cm respectively. In this way, the capillary pressure of brine-gas system was estimated as 0.488 psi, therefore diesel-gas system was noticed about 0.164 psi and 0.098 psi for condensate-gas system. A forecast model was used by using IFT values to predict the phase trapping which shows less severe phase trapping damage in case of condensate than diesel and brine. A reservoir simulation study was also carried out in order to better understand the effect of hysteresis on well productivity and flow efficiency affected due to water blocking damage in tight gas reservoirs.

  17. Heterogeneous Earth Accretion and Incomplete Metal-Silicate Reequilibration at High Pressure During Core Formation

    NASA Astrophysics Data System (ADS)

    Rubie, D. C.; Mann, U.; Frost, D. J.; Kegler, P.; Holzheid, A.; Palme, H.

    2007-12-01

    We present a new model of core formation, based on the partitioning of siderophile elements, that involves accreting the Earth through a series of collisions with smaller bodies that had already differentiated at low pressure. Each impact results in a magma ocean in which the core of the impactor reequilibrates with silicate liquid at high pressure before merging with the Earth's protocore. The oxygen contents of the chondritic compositions of the proto-Earth and impactors can be varied. The compositions of coexisting metal and silicate are determined through mass balance combined with partitioning equations for Ni, FeO, Si and other siderophile elements. The oxygen fugacity is fixed by the partitioning of FeO and is a function of P, T and bulk oxygen content. An important constraint for core formation is that core-mantle partition coefficients for Ni and Co must both converge to values of 23-28. Based on a recent study of the partitioning of Ni and Co over a wide P-T range (Kegler et al., EPSL, submitted) together with other published data, this constraint is not satisfied by a single- stage core formation model at any conditions because the partition coefficients converge at values that are much too low. In the present multi-stage model, the correct values can be reached if only part of each impactor core reequilibrates with silicate liquid in the magma ocean (as proposed by previous models based on Hf-W isotope studies). Physically, this would mean that impactor cores fail to emulsify completely as they sink through the magma ocean. Incorporating other elements (e.g. V and Cr) in the model requires, in addition, that the bulk composition of the impactors changes during accretion from reduced (FeO-poor) to oxidised FeO-rich). Then, with the resulting increase in fO2, incomplete reequilibration of the cores during the final 20-30% of Earth accretion is required to satisfy the Ni-Co constraint. In addition, this model enables the concentrations of O and Si in the

  18. Combined V-Y Fasciocutaneous Advancement and Gluteus Maximus Muscle Rotational Flaps for Treating Sacral Sores

    PubMed Central

    Choi, Eun Jeong; Moon, Suk Ho; Lee, Yoon Jae

    2016-01-01

    The sacral area is the most common site of pressure sore in bed-ridden patients. Though many treatment methods have been proposed, a musculocutaneous flap using the gluteus muscles or a fasciocutaneous flap is the most popular surgical option. Here, we propose a new method that combines the benefits of these 2 methods: combined V-Y fasciocutaneous advancement and gluteus maximus muscle rotational flaps. A retrospective review was performed for 13 patients who underwent this new procedure from March 2011 to December 2013. Patients' age, sex, accompanying diseases, follow-up duration, surgical details, complications, and recurrence were documented. Computed tomography was performed postoperatively at 2 to 4 weeks and again at 4 to 6 months to identify the thickness and volume of the rotational muscle portion. After surgery, all patients healed within 1 month; 3 patients experienced minor complications. The average follow-up period was 13.6 months, during which time 1 patient had a recurrence (recurrence rate, 7.7%). Average thickness of the rotated muscle was 9.43 mm at 2 to 4 weeks postoperatively and 9.22 mm at 4 to 6 months postoperatively (p = 0.087). Muscle thickness had not decreased, and muscle volume was relatively maintained. This modified method is relatively simple and easy for reconstructing sacral sores, provides sufficient padding, and has little muscle donor-site morbidity. PMID:27366755

  19. Heating methods for reducing unevenness softening of mouthguard sheets in vacuum-pressure formation.

    PubMed

    Takahashi, Mutsumi; Koide, Kaoru; Satoh, Yoshihide; Iwasaki, Shin-Ichi

    2016-08-01

    Unevenness in softening of the plastic sheet leads to a decrease in the mouthguard thickness during thermoforming. In this study, we examined the heating methods for reducing unevenness when softening mouthguard sheets during vacuum-pressure formation. Ethylene vinyl acetate mouthguard sheets and olefin copolymer sheets (thickness: 4.0 mm) were used. The following three heating conditions were compared: condition A-the sheet was molded when it sagged 15 mm from the sheet frame (under normal condition); condition B-the heater was turned off when the sheet sagged by 10 mm from the frame, followed by the sheet molding when the sagging reached 15 mm below the frame; and condition C-the sheet was inverted after heating when the sheet sagged 10 mm and was molded when the sagging reached 15 mm below the frame. The sheet was heated and pressed over the model using a vacuum-pressure machine; then, 10 s of vacuum forming and 2 min of pressure molding were applied. The sheet temperatures were measured using a radiation thermometer. Thickness of the fabricated sheets was determined for the incisal and the molar portion using a measuring device. Thickness data for each condition were analyzed by one-way anova followed by Bonferroni's multiple comparison tests. On both sheets, condition B was smallest for temperature difference between the heated and the non-heated surface, and thicknesses after molding were greatest at all measuring portions. By comparing changes in sheet temperatures at molding and variation in thicknesses when applying the heating method using a vacuum-pressure molding machine, we found that reduced unevenness in sheet softening occurred when the heater was turned off when the sag distance of the sheet was 5 mm less than the conventional molding, and then, the sheet was pressed when the conventional sag distance was reached. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. Possible mechanism underlying high-pressure unfolding of proteins: formation of a short-period high-density hydration shell.

    PubMed

    Sumi, Tomonari; Sekino, Hideo

    2011-09-21

    Hydration effects on high-pressure unfolding of a hydrophobic polymer chain are investigated through a multiscale simulation based on density-functional theory. The results strongly suggest the following: a thermodynamic origin for high-pressure denaturation, i.e., the decrease in volume due to the unfolding can be explained by the formation of a short-period high-density hydration shell.

  1. Sore throat: effective communication delivers improved diagnosis, enhanced self-care and more rational use of antibiotics.

    PubMed

    van der Velden, A W; Bell, J; Sessa, A; Duerden, M; Altiner, A

    2013-11-01

    The majority of throat infections are of viral origin and resolve without antibiotic treatment. Despite this, antibiotic use for sore throat infections remains high, partly because it is difficult to determine when antibiotics may be useful, on the basis of physical findings alone. Antibiotics may be beneficial in bacterial throat infections under certain clinical and epidemiological circumstances; however, even many of those infections in which bacteria play a role do resolve just as quickly without antibiotics. Furthermore, non-medical factors such as patient expectations and patient pressure are also important drivers of antibiotic use. To address these issues, a behavioural change is required that can be facilitated by improved communication between primary healthcare providers and patients. In this article, we provide doctors, nurses and pharmacy staff, working in primary care or in the community, with a structured approach to sore throat management, with the aim of educating and empowering patients to self-manage their condition. The first component of this approach involves identifying and addressing patients' expectations and concerns with regard to their sore throat and eliciting their opinion on antibiotics. The second part is dedicated to a pragmatic assessment of the severity of the condition, with attention to red-flag symptoms and risk factors for serious complications. Rather than just focusing on the cause (bacterial or viral) of the upper respiratory tract infections as a rationale for antibiotic use, healthcare providers should instead consider the severity of the patient's condition and whether they are at high risk of complications. The third part involves counselling patients on effective self-management options and providing information on the expected clinical course. Such a structured approach to sore throat management, using empathetic, non-paternalistic language, combined with written patient information, will help to drive patient

  2. Implications for Core Formation of the Earth from High Pressure-Temperature Au Partitioning Experiments

    NASA Technical Reports Server (NTRS)

    Danielson, L. R.; Sharp, T. G.; Hervig, R. L.

    2005-01-01

    Siderophile elements in the Earth.s mantle are depleted relative to chondrites. This is most pronounced for the highly siderophile elements (HSEs), which are approximately 400x lower than chondrites. Also remarkable is the relative chondritic abundances of the HSEs. This signature has been interpreted as representing their sequestration into an iron-rich core during the separation of metal from silicate liquids early in the Earth's history, followed by a late addition of chondritic material. Alternative efforts to explain this trace element signature have centered on element partitioning experiments at varying pressures, temperatures, and compositions (P-T-X). However, first results from experiments conducted at 1 bar did not match the observed mantle abundances, which motivated the model described above, a "late veneer" of chondritic material deposited on the earth and mixed into the upper mantle. Alternatively, the mantle trace element signature could be the result of equilibrium partitioning between metal and silicate in the deep mantle, under P-T-X conditions which are not yet completely identified. An earlier model determined that equilibrium between metal and silicate liquids could occur at a depth of approximately 700 km, 27(plus or minus 6) GPa and approximately 2000 (plus or minus 200) C, based on an extrapolation of partitioning data for a variety of moderately siderophile elements obtained at lower pressures and temperatures. Based on Ni-Co partitioning, the magma ocean may have been as deep as 1450 km. At present, only a small range of possible P-T-X trace element partitioning conditions has been explored, necessitating large extrapolations from experimental to mantle conditions for tests of equilibrium models. Our primary objective was to reduce or remove the additional uncertainty introduced by extrapolation by testing the equilibrium core formation hypothesis at P-T-X conditions appropriate to the mantle.

  3. Estimating Hydraulic Conductivities in a Fractured Shale Formation from Pressure Pulse Testing and 3d Modeling

    NASA Astrophysics Data System (ADS)

    Courbet, C.; DICK, P.; Lefevre, M.; Wittebroodt, C.; Matray, J.; Barnichon, J.

    2013-12-01

    In the framework of its research on the deep disposal of radioactive waste in shale formations, the French Institute for Radiological Protection and Nuclear Safety (IRSN) has developed a large array of in situ programs concerning the confining properties of shales in their underground research laboratory at Tournemire (SW France). One of its aims is to evaluate the occurrence and processes controlling radionuclide migration through the host rock, from the disposal system to the biosphere. Past research programs carried out at Tournemire covered mechanical, hydro-mechanical and physico-chemical properties of the Tournemire shale as well as water chemistry and long-term behaviour of the host rock. Studies show that fluid circulations in the undisturbed matrix are very slow (hydraulic conductivity of 10-14 to 10-15 m.s-1). However, recent work related to the occurrence of small scale fractures and clay-rich fault gouges indicate that fluid circulations may have been significantly modified in the vicinity of such features. To assess the transport properties associated with such faults, IRSN designed a series of in situ and laboratory experiments to evaluate the contribution of both diffusive and advective process on water and solute flux through a clay-rich fault zone (fault core and damaged zone) and in an undisturbed shale formation. As part of these studies, Modular Mini-Packer System (MMPS) hydraulic testing was conducted in multiple boreholes to characterize hydraulic conductivities within the formation. Pressure data collected during the hydraulic tests were analyzed using the nSIGHTS (n-dimensional Statistical Inverse Graphical Hydraulic Test Simulator) code to estimate hydraulic conductivity and formation pressures of the tested intervals. Preliminary results indicate hydraulic conductivities of 5.10-12 m.s-1 in the fault core and damaged zone and 10-14 m.s-1 in the adjacent undisturbed shale. Furthermore, when compared with neutron porosity data from borehole

  4. Prospective surveillance of streptococcal sore throat in a tropical country.

    PubMed

    Steer, Andrew C; Jenney, Adam W J; Kado, Joseph; Good, Michael F; Batzloff, Michael; Magor, Graham; Ritika, Roselyn; Mulholland, Kim E; Carapetis, Jonathan R

    2009-06-01

    Acute rheumatic fever and rheumatic heart disease cause a high burden of disease in Fiji and surrounding Pacific Island countries, but little is known about the epidemiology of group A streptococcal (GAS) pharyngitis in the region. We designed a study to estimate the prevalence of carriage of beta-hemolytic streptococci (BHS) and the incidence of BHS culture-positive sore throat in school aged children in Fiji. We conducted twice-weekly prospective surveillance of school children aged 5 to 14 years in 4 schools in Fiji during a 9-month period in 2006, after an initial phase of pharyngeal swabbing to determine the prevalence of BHS carriage. We enrolled 685 children. The prevalence of GAS carriage was 6.0%, while the prevalence of group C streptococcal (GCS) and group G streptococcal (GGS) carriage was 6.9% and 12%, respectively. There were 61 episodes of GAS culture-positive sore throat during the study period equating to an incidence of 14.7 cases per 100 child-years (95% CI, 11.2-18.8). The incidence of GCS/GGS culture-positive sore throat was 28.8 cases per 100 child-years (95% CI, 23.9-34.5). The clinical nature of GAS culture-positive sore throat was more severe than culture-negative sore throat, but overall was mild compared with that found in previous studies. Of the 101 GAS isolates that emm sequence typed there were 45 emm types with no dominant types. There were very few emm types commonly encountered in industrialized nations and only 9 of the 45 emm types found in this study are emm types included in the 26-valent GAS vaccine undergoing clinical trials. GAS culture-positive sore throat was more common than expected. Group C and group G streptococci were frequently isolated in throat cultures, although their contribution to pharyngeal infection is not clear. The molecular epidemiology of pharyngeal GAS in our study differed greatly from that in industrialized nations and this has implications for GAS vaccine clinical research in Fiji and other tropical

  5. The anatomy of a star-forming galaxy: pressure-driven regulation of star formation in simulated galaxies

    NASA Astrophysics Data System (ADS)

    Benincasa, S. M.; Wadsley, J.; Couchman, H. M. P.; Keller, B. W.

    2016-11-01

    We explore the regulation of star formation in star-forming galaxies through a suite of high-resolution isolated galaxy simulations. We use the smoothed particle hydrodynamics code GASOLINE, including photoelectric heating and metal cooling, which produces a multi-phase interstellar medium (ISM). We show that representative star formation and feedback sub-grid models naturally lead to a weak, sub-linear dependence between the amount of star formation and changes to star formation parameters. We incorporate these sub-grid models into an equilibrium pressure-driven regulation framework. We show that the sub-linear scaling arises as a consequence of the non-linear relationship between scaleheight and the effective pressure generated by stellar feedback. Thus, simulated star formation regulation is sensitive to how well vertical structure in the ISM is resolved. Full galaxy discs experience density waves which drive locally time-dependent star formation. We develop a simple time-dependent, pressure-driven model that reproduces the response extremely well.

  6. Mechanisms for negative reactant ion formation in an atmospheric pressure corona discharge

    SciTech Connect

    Ewing, Robert G.; Waltman, Melanie J.

    2009-06-02

    In an effort to better understand the formation of negative reactant ions in air produced by an atmospheric pressure corona discharge source, the neutral vapors generated by the corona were introduced in varying amounts into the ionization region of an ion mobility spectrometer/mass spectrometer containing a 63Ni ionization source. With no discharge gas the predominant ions were O2- , however, upon the introduction of low levels of discharge gas the NO2- ion quickly became the dominant species. As the amount of discharge gas increased the appearance of CO3- was observed followed by the appearance of NO3-. At very high levels, NO3- species became effectively the only ion present and appeared as two peaks in the IMS spectrum, NO3- and the NO3-•HNO3 adduct, with separate mobilities. Since explosive compounds typically ionize in the presence of negative reactant ions, the ionization of an explosive, RDX, was examined in order to investigate the ionization properties with these three primary ions. It was found that RDX forms a strong adduct with both NO2- and NO3- with reduced mobility values of 1.49 and 1.44 cm2V-1s-1, respectively. No adduct was observed for RDX with CO3- although this adduct has been observed with a corona discharge mass spectrometer. It is believed that this adduct, although formed, does not have a sufficiently long lifetime (greater than 10 ms) to be observed in an ion mobility spectrometer.

  7. Laser-driven formation of a high-pressure phase in amorphous silica.

    PubMed

    Salleo, Alberto; Taylor, Seth T; Martin, Michael C; Panero, Wendy R; Jeanloz, Raymond; Sands, Timothy; Génin, François Y

    2003-12-01

    Because of its simple composition, vast availability in pure form and ease of processing, vitreous silica is often used as a model to study the physics of amorphous solids. Research in amorphous silica is also motivated by its ubiquity in modern technology, a prominent example being as bulk material in transmissive and diffractive optics for high-power laser applications such as inertial confinement fusion (ICF). In these applications, stability under high-fluence laser irradiation is a key requirement, with optical breakdown occurring when the fluence of the beam is higher than the laser-induced damage threshold (LIDT) of the material. The optical strength of polished fused silica transmissive optics is limited by their surface LIDT. Surface optical breakdown is accompanied by densification, formation of point defects, cratering, material ejection, melting and cracking. Through a combination of electron diffraction and infrared reflectance measurements we show here that synthetic vitreous silica transforms partially into a defective form of the high-pressure stishovite phase under high-intensity (GW cm(-2)) laser irradiation. This phase transformation offers one suitable mechanism by which laser-induced damage grows catastrophically once initiated, thereby dramatically shortening the service lifetime of optics used for high-power photonics.

  8. Electrohydrodynamic pressure enhanced by free space charge for electrically induced structure formation with high aspect ratio.

    PubMed

    Tian, Hongmiao; Wang, Chunhui; Shao, Jinyou; Ding, Yucheng; Li, Xiangming

    2014-10-28

    Electrically induced structure formation (EISF) is an interesting and unique approach for generating a microstructured duplicate from a rheological polymer by a spatially modulated electric field induced by a patterned template. Most of the research on EISF have so far used various dielectric polymers (with an electrical conductivity smaller than 10(-10) S/m that can be considered a perfect dielectric), on which the electric field induces a Maxwell stress only due to the dipoles (or bounded charges) in the polymer molecules, leading to a structure with a small aspect ratio. This paper presents a different approach for improving the aspect ratio allowed in EISF by doping organic salt into the perfect dielectric polymer, i.e., turning the perfect dielectric into a leaky dielectric, considering the fact that the free space charges enriched in the leaky dielectric polymer can make an additional contribution to the Maxwell stress, i.e., electrohydrodynamic pressure, which is desirable for high aspect ratio structuring. Our numerical simulations and experimental tests have shown that a leaky dielectric polymer, with a small conductivity comparable to that of deionized water, can be much more effective at being electrohydrodynamically deformed into a high aspect ratio in comparison with a perfect dielectric polymer when both of them have roughly the same dielectric constant.

  9. Formation and characteristics of patterns in atmospheric-pressure radio-frequency dielectric barrier discharge plasma

    NASA Astrophysics Data System (ADS)

    Yang, Lizhen; Liu, Zhongwei; Mao, Zhiguo; Li, Sen; Chen, Qiang

    2017-01-01

    The patterns in radio-frequency dielectric barrier discharge (RF DBD) are studied at atmospheric pressure of argon (Ar) or helium (He) mixed with nitrogen (N2) gas. When a small amount of N2 is mixed with He or Ar gas, discharge patterns are formed. In a N2/He gas mixture, besides the filament discharge that forms patterns, a glow background discharge is also observed, whereas only the filament discharge forms patterns in a N2/Ar gas mixture. The resolution of the hexagonal pattern as a function of applied power and gas flow rate is then explored. On the basis of spatial-temporal images taken using an intensified charge-coupled device (ICCD), we find that there is no interleaving of two transient hexagon sublattices in N2/Ar or N2/He plasma in RF DBD patterns, which are totally different from those in which surface charges dominated in the mid-frequency DBD plasma. This supports our hypothesis that the bulk charges dominate the pattern formation in RF DBD.

  10. Isomekes: A fundamental tool to determine the formation pressure for diamond-inclusion pairs

    NASA Astrophysics Data System (ADS)

    Alvaro, Matteo; Angel, Ross; Mazzucchelli, Mattia; Nestola, Fabrizio; Domeneghetti, Chiara

    2014-05-01

    Because diamond is almost chemically pure carbon and extremely chemically inert, the structure and chemistry of diamond reveals very little about its conditions of formation. Much of what is believed about the genesis and distribution of diamond in the Earth's mantle has therefore been deduced indirectly from the characterisation of its mineral inclusions. The possible depths of entrapment of an inclusion within a host phase (and hence the depth of growth of the host diamond) can be determined if (1) the final pressure of the inclusion can be measured, (2) the Equations of State (EoS) of the host and inclusion phases are known, and (3) the elastic interaction between the host and inclusion can be calculated without gross assumptions. Given knowledge of all three, an isomeke line in P-T space (from the Greek "equal" and "length", Adams et al. 1975) can be calculated. The isomeke defines the conditions at which the host and inclusion would have had the same P, T and volume, and thus represents possible entrapment conditions. The recent application (Nestola et al. 2011; Howell et al. 2012) of in-situ diffraction techniques to the measurement of entrapped inclusions provides accurate final inclusion pressures. We have reformulated the elasticity problem so that, unlike previous work, these calculations can be performed with any form of equation of state and thermal expansion, and are not restricted to linear elasticity or just invertible EoS. This alone has significant advantages in the precision of the calculated depths of formation. Numerical calculations have been performed with a new module of EoS routines (Angel et al. 2014) that has been added to the publicly-available CrysFML library. The question remains as to what uncertainties in calculated depths of formation arise from uncertainties in experimentally-determined EoS. We will present two geologically-relevant examples, for olivine and garnet in diamond. Our calculations show that there is still a clear need

  11. Diagenesis, compaction, and fluid chemistry modeling of a sandstone near a pressure seal: Lower Tuscaloosa Formation, Gulf Coast

    USGS Publications Warehouse

    Weedman, S.D.; Brantley, S.L.; Shiraki, R.; Poulson, S.R.

    1996-01-01

    Petrographic, isotopic, and fluid-inclusion evidence from normally and overpressured sandstones of the lower Tuscaloosa Formation (Upper Cretaceous) in the Gulf Coast documents quartz-overgrowth precipitation at 90??C or less, calcite cement precipitation at approximately 100?? and 135??C, and prismatic quartz cement precipitation at about 125??C. Textural evidence suggests that carbonate cement dissolution occurred before the second phases of calcite and quartz precipitation, and was followed by precipitation of grain-rimming chlorite and pore-filling kaolinite. Geochemical calculations demonstrate that present-day lower Tuscaloosa Formation water from 5500 m depth could either dissolve or precipitate calcite cements in model simulations of upward water flow. Calcite dissolution or precipitation depends on PCO2 variability with depth (i.e., whether there is one or two-phase flow) or on the rate of generation of CO2 with depth. Calculations suggest that 105-106 rock volumes of water are required to flow through the section to precipitate 1-10% calcite cement. Compaction analysis suggests that late-stage compaction occurred in normally pressured sandstones after dissolution of carbonate cements, but was hindered in overpressured sandstones despite the presence of high porosity. These results document the inhibition of compaction by overpressured fluids and constrain the timing of pressure seal formation. Modeling results demonstrate that the proposed paragenesis used to constrain timing of pressure seal formation is feasible, and that most of the cement diagenesis occurred before the pressure seal became effective as a permeability barrier.

  12. Ear Acupuncture for Acute Sore Throat: A Randomized Controlled Trial

    DTIC Science & Technology

    2014-09-26

    SEP 2014 2. REPORT TYPE Final 3. DATES COVERED 4. TITLE AND SUBTITLE Ear acupuncture for acute sore throat. A randomized controlled trial...Auncular Acupuncture is a low risk option for acute pain control •Battlefield acupuncture (BFA) IS a specific auncular acupuncture technique •BFA IS...Strengths: Prospect1ve RCT •Weaknesses Small sample stze. no sham acupuncture performed, patients not blinded to treatment •Th1s study represents an

  13. Whole-Body Vibration and the Prevention and Treatment of Delayed-Onset Muscle Soreness

    PubMed Central

    Aminian-Far, Atefeh; Hadian, Mohammad-Reza; Olyaei, Gholamreza; Talebian, Saeed; Bakhtiary, Amir Hoshang

    2011-01-01

    Abstract Context: Numerous recovery strategies have been used in an attempt to minimize the symptoms of delayed-onset muscle soreness (DOMS). Whole-body vibration (WBV) has been suggested as a viable warm-up for athletes. However, scientific evidence to support the protective effects of WBV training (WBVT) on muscle damage is lacking. Objective: To investigate the acute effect of WBVT applied before eccentric exercise in the prevention of DOMS. Design: Randomized controlled trial. Setting: University laboratory. Patients or Other Participants: A total of 32 healthy, untrained volunteers were randomly assigned to either the WBVT (n  =  15) or control (n  =  17) group. Intervention(s): Volunteers performed 6 sets of 10 maximal isokinetic (60°/s) eccentric contractions of the dominant-limb knee extensors on a dynamometer. In the WBVT group, the training was applied using a vibratory platform (35 Hz, 5 mm peak to peak) with 100° of knee flexion for 60 seconds before eccentric exercise. No vibration was applied in the control group. Main Outcome Measure(s): Muscle soreness, thigh circumference, and pressure pain threshold were recorded at baseline and at 1, 2, 3, 4, 7, and 14 days postexercise. Maximal voluntary isometric and isokinetic knee extensor strength were assessed at baseline, immediately after exercise, and at 1, 2, 7, and 14 days postexercise. Serum creatine kinase was measured at baseline and at 1, 2, and 7 days postexercise. Results: The WBVT group showed a reduction in DOMS symptoms in the form of less maximal isometric and isokinetic voluntary strength loss, lower creatine kinase levels, and less pressure pain threshold and muscle soreness (P < .05) compared with the control group. However, no effect on thigh circumference was evident (P < .05). Conclusions: Administered before eccentric exercise, WBVT may reduce DOMS via muscle function improvement. Further investigation should be undertaken to ascertain the effectiveness of WBVT in

  14. Modulation in voluntary neural drive in relation to muscle soreness

    PubMed Central

    Bringard, A.; Puchaux, K.; Noakes, T. D.; Perrey, S.

    2007-01-01

    The aim of this study was to investigate whether (1) spinal modulation would change after non-exhausting eccentric exercise of the plantar flexor muscles that produced muscle soreness and (2) central modulation of the motor command would be linked to the development of muscle soreness. Ten healthy subjects volunteered to perform a single bout of backward downhill walking exercise (duration 30 min, velocity 1 ms−1, negative grade −25%, load 12% of body weight). Neuromuscular test sessions [H-reflex, M-wave, maximal voluntary torque (MVT)] were performed before, immediately after, as well as 1–3 days after the exercise bout. Immediately after exercise there was a −15% decrease in MVT of the plantar flexors partly attributable to an alteration in contractile properties (−23% in electrically evoked mechanical twitch). However, MVT failed to recover before the third day whereas the contractile properties had significantly recovered within the first day. This delayed recovery of MVT was likely related to a decrement in voluntary muscle drive. The decrease in voluntary activation occurred in the absence of any variation in spinal modulation estimated from the H-reflex. Our findings suggest the development of a supraspinal modulation perhaps linked to the presence of muscle soreness. PMID:17978834

  15. Pressure-driven assembly of spherical nanoparticles and formation of 1D nanostructure arrays.

    SciTech Connect

    Wu, Huimeng

    2010-08-01

    External pressure was used to engineer nanoparticle assembly. Reversible manipulation of the unit-cell dimensions of a 3D ordered nanoparticle array under a hydrostatic pressure field enabled the fine-tuning of the interparticle distance. Under a uniaxial pressure field, nanoparticles were forced to contact and coalesce into nanorods or nanowires and ordered ultrahigh-density arrays (see picture; small arrows denote pressure).

  16. Formation Process of High-Pressure Silica Polymorphs in Lunar Meteorites of the NWA 773 Clan

    NASA Astrophysics Data System (ADS)

    Kayama, M.; Tomioka, N.; Seto, Y.; Ohtani, E.; Nagaoka, H.; Fagan, T. J.; Ozawa, S.; Sekine, T.; Miyahara, M.; Miyake, A.; Tomeoka, K.

    2016-08-01

    Recent studies of lunar samples discovered high-pressure phases of silica in Asuka-881757, NWA 4734 and Apollo 15299. Here, we first discovered high-pressure silica from lunar meteorite NWA 773 clan, constraining the shock-pressure and temperature.

  17. Foam Rolling for Delayed-Onset Muscle Soreness and Recovery of Dynamic Performance Measures

    PubMed Central

    Pearcey, Gregory E. P.; Bradbury-Squires, David J.; Kawamoto, Jon-Erik; Drinkwater, Eric J.; Behm, David G.; Button, Duane C.

    2015-01-01

    Context: After an intense bout of exercise, foam rolling is thought to alleviate muscle fatigue and soreness (ie, delayed-onset muscle soreness [DOMS]) and improve muscular performance. Potentially, foam rolling may be an effective therapeutic modality to reduce DOMS while enhancing the recovery of muscular performance. Objective: To examine the effects of foam rolling as a recovery tool after an intense exercise protocol through assessment of pressure-pain threshold, sprint time, change-of-direction speed, power, and dynamic strength-endurance. Design: Controlled laboratory study. Setting: University laboratory. Patients or Other Participants: A total of 8 healthy, physically active males (age = 22.1 ± 2.5 years, height = 177.0 ± 7.5 cm, mass = 88.4 ± 11.4 kg) participated. Intervention(s): Participants performed 2 conditions, separated by 4 weeks, involving 10 sets of 10 repetitions of back squats at 60% of their 1-repetition maximum, followed by either no foam rolling or 20 minutes of foam rolling immediately, 24, and 48 hours postexercise. Main Outcome Measure(s): Pressure-pain threshold, sprint speed (30-m sprint time), power (broad-jump distance), change-of-direction speed (T-test), and dynamic strength-endurance. Results: Foam rolling substantially improved quadriceps muscle tenderness by a moderate to large amount in the days after fatigue (Cohen d range, 0.59 to 0.84). Substantial effects ranged from small to large in sprint time (Cohen d range, 0.68 to 0.77), power (Cohen d range, 0.48 to 0.87), and dynamic strength-endurance (Cohen d = 0.54). Conclusions: Foam rolling effectively reduced DOMS and associated decrements in most dynamic performance measures. PMID:25415413

  18. Synergistic and additive effects of hydrostatic pressure and growth factors on tissue formation.

    PubMed

    Elder, Benjamin D; Athanasiou, Kyriacos A

    2008-06-04

    Hydrostatic pressure (HP) is a significant factor in the function of many tissues, including cartilage, knee meniscus, temporomandibular joint disc, intervertebral disc, bone, bladder, and vasculature. Though studies have been performed in assessing the role of HP in tissue biochemistry, to the best of our knowledge, no studies have demonstrated enhanced mechanical properties from HP application in any tissue. The objective of this study was to determine the effects of hydrostatic pressure (HP), with and without growth factors, on the biomechanical and biochemical properties of engineered articular cartilage constructs, using a two-phased approach. In phase I, a 3x3 full-factorial design of HP magnitude (1, 5, 10 MPa) and frequency (0, 0.1, 1 Hz) was used, and the best two treatments were selected for use in phase II. Static HP at 5 MPa and 10 MPa resulted in significant 95% and 96% increases, respectively, in aggregate modulus (H(A)), with corresponding increases in GAG content. These regimens also resulted in significant 101% and 92% increases in Young's modulus (E(Y)), with corresponding increases in collagen content. Phase II employed a 3x3 full-factorial design of HP (no HP, 5 MPa static, 10 MPa static) and growth factor application (no GF, BMP-2+IGF-I, TGF-beta1). The combination of 10 MPa static HP and TGF-beta1 treatment had an additive effect on both H(A) and E(Y), as well as a synergistic effect on collagen content. This group demonstrated a 164% increase in H(A), a 231% increase in E(Y), an 85% increase in GAG/wet weight (WW), and a 173% increase in collagen/WW, relative to control. To our knowledge, this is the first study to demonstrate increases in the biomechanical properties of tissue from pure HP application, using a cartilage model. Furthermore, it is the only study to demonstrate additive or synergistic effects between HP and growth factors on tissue functional properties. These findings are exciting as coupling HP stimulation with growth factor

  19. Soot volume fraction measurement in low-pressure methane flames by combining laser-induced incandescence and cavity ring-down spectroscopy: Effect of pressure on soot formation

    SciTech Connect

    Desgroux, P.; Mercier, X.; Lefort, B.; Lemaire, R.; Therssen, E.; Pauwels, J.F.

    2008-10-15

    Soot volume fraction (f{sub v}) profiles are recorded in low-pressure methane/oxygen/nitrogen flat flames using laser-induced incandescence (LII). Experiments are performed from 20 to 28 kPa in flames having the same equivalence ratio (2.32). Calibration is performed by cavity ring-down spectroscopy (CRDS) and indicates a very weak soot volume fraction (0.066 ppb at 21.33 kPa and 0.8 ppb at 26.66 kPa in the burnt gases). Soot volume fraction is found to increase continuously after a given distance above the burner (HAB) and tends to level off in the burnt gases. The reaction time resolution available in low-pressure flames makes it possible to examine the early steps of soot formation. The variation of the LII signal with laser energy before the LII ''plateau'' region is much weaker at the beginning of soot formation than after a given reaction time. The LII time decays are nearly constant within the first millimetres, whereas an increase in the decay, correlated with the growth of the primary soot particle, is observed later. The growth of soot volume fraction is then analysed by considering the variation of the derivative function df{sub v}/dt with f{sub v}. Three regimes having respectively a positive slope, a constant slope, and a negative slope are observed and are interpreted with respect to the soot inception process. Finally, a very important sensitivity of f{sub v} with pressure P (at 30 mm HAB) is observed, leading to a power law, f{sub v}=KP{sup 11}, confirmed by extinction measurements (by CRDS). The observed dependence of f{sub v} with pressure could be a result of the prominence of the early soot inception process in the investigated low-pressure flames. (author)

  20. Soot Formation in Laminar Premixed Ethylene/Air Flames at Atmospheric Pressure. Appendix G

    NASA Technical Reports Server (NTRS)

    Xu, F.; Sunderland, P. B.; Faeth, G. M.; Urban, D. L. (Technical Monitor)

    2001-01-01

    Soot formation was studied within laminar premixed ethylene/air flames (C/O ratios of 0.78-0.98) stabilized on a flat-flame burner operating at atmospheric pressure. Measurements included soot volume fractions by both laser extinction and gravimetric methods, temperatures by multiline emission, soot structure by thermophoretic sampling and transmission electron microscopy, major gas species concentrations by sampling and gas chromatography, concentrations of condensable hydrocarbons by gravimetric sampling. and velocities by laser velocimetry. These data were used to find soot surface growth rates and primary soot particle nucleation rates along the axes of the flames. Present measurements of soot surface growth rates were correlated successfully by predictions based on typical hydrogen-abstraction/carbon-addition (HACA) mechanisms of Frenklach and co-workers and Colket and Hall. These results suavest that reduced soot surface growth rates with increasing residence time seen in the present and other similar flames were mainly caused by reduced rates of surface activation due to reduced H atom concentrations as temperatures decrease as a result of radiative heat losses. Primary soot particle nucleation rates exhibited variations with temperature and acetylene concentrations that were similar to recent observations for diffusion flames; however, nucleation rates in the premixed flames were significantly lower than in, the diffusion flames for reasons that still must be explained. Finally, predictions of yields of major gas species based on mechanisms from both Frenklach and co-workers and Leung and Lindstedt were in good agreement with present measurements and suggest that H atom concentrations (relevant to HACA mechanisms) approximate estimates based on local thermodynamic equilibrium in the present flames.

  1. High positive end-expiratory pressure: only a dam against oedema formation?

    PubMed Central

    2013-01-01

    Introduction Healthy piglets ventilated with no positive end-expiratory pressure (PEEP) and with tidal volume (VT) close to inspiratory capacity (IC) develop fatal pulmonary oedema within 36 h. In contrast, those ventilated with high PEEP and low VT, resulting in the same volume of gas inflated (close to IC), do not. If the real threat to the blood-gas barrier is lung overinflation, then a similar damage will occur with the two settings. If PEEP only hydrostatically counteracts fluid filtration, then its removal will lead to oedema formation, thus revealing the deleterious effects of overinflation. Methods Following baseline lung computed tomography (CT), five healthy piglets were ventilated with high PEEP (volume of gas around 75% of IC) and low VT (25% of IC) for 36 h. PEEP was then suddenly zeroed and low VT was maintained for 18 h. Oedema was diagnosed if final lung weight (measured on a balance following autopsy) exceeded the initial one (CT). Results Animals were ventilated with PEEP 18 ± 1 cmH2O (volume of gas 875 ± 178 ml, 89 ± 7% of IC) and VT 213 ± 10 ml (22 ± 5% of IC) for the first 36 h, and with no PEEP and VT 213 ± 10 ml for the last 18 h. On average, final lung weight was not higher, and actually it was even lower, than the initial one (284 ± 62 vs. 347 ± 36 g; P = 0.01). Conclusions High PEEP (and low VT) do not merely impede fluid extravasation but rather preserve the integrity of the blood-gas barrier in healthy lungs. PMID:23844622

  2. Methane hydrate synthesis from ice: Influence of pressurization and ethanol on optimizing formation rates and hydrate yield

    USGS Publications Warehouse

    Chen, Po-Chun.; Huang, Wuu-Liang; Stern, Laura A.

    2010-01-01

    Polycrystalline methane gas hydrate (MGH) was synthesized using an ice-seeding method to investigate the influence of pressurization and ethanol on the hydrate formation rate and gas yield of the resulting samples. When the reactor is pressurized with CH4 gas without external heating, methane hydrate can be formed from ice grains with yields up to 25% under otherwise static conditions. The rapid temperature rise caused by pressurization partially melts the granular ice, which reacts with methane to form hydrate rinds around the ice grains. The heat generated by the exothermic reaction of methane hydrate formation buffers the sample temperature near the melting point of ice for enough time to allow for continuous hydrate growth at high rates. Surprisingly, faster rates and higher yields of methane hydrate were found in runs with lower initial temperatures, slower rates of pressurization, higher porosity of the granular ice samples, or mixtures with sediments. The addition of ethanol also dramatically enhanced the formation of polycrystalline MGH. This study demonstrates that polycrystalline MGH with varied physical properties suitable for different laboratory tests can be manufactured by controlling synthesis procedures or parameters. Subsequent dissociation experiments using a gas collection apparatus and flowmeter confirmed high methane saturation (CH 4·2O, with n = 5.82 ± 0.03) in the MGH. Dissociation rates of the various samples synthesized at diverse conditions may be fitted to different rate laws, including zero and first order.

  3. In Situ Formation and Evolution of Gas Hydrates in Water-in-Oil Emulsions Using Pressure Rheometry

    NASA Astrophysics Data System (ADS)

    Rensing, P. J.; Liberatore, M. W.; Tonmukayakul, N.; Koh, C. A.; Sloan, E. D.

    2008-07-01

    In oil and gas production and transportation a major concern is the formation of gas hydrates (crystalline gas-water inclusion compounds that are stable at high pressures and low temperatures). Gas hydrates have a tenacious ability to plug pipelines, and may lead to unscheduled shut downs. The successful operation of pipeline transport with gas hydrates particles will depend on the ability to control gas hydrate agglomerations and depositions. Gas hydrates can be thermodynamically inhibited but this is proving cost ineffective and environmentally unfriendly. For this reason the oil/gas industry is moving to hydrate management rather than traditional methods of thermodynamic inhibition. One intriguing possibility would be to convert the water in the pipelines to non-agglomerating gas hydrates and then flow the slurry. However, this cannot be reliably achieved until basic understanding of hydrate slurry rheology is gained. To develop this fundamental understanding, in situ pressurized gas hydrate formation and rheological measurements from a water-in-oil emulsion have been conducted. In this work, small amplitude oscillatory and steady shear techniques have been used to characterize the rheological properties of these systems. The results demonstrate that hydrate formation can be detected in steady shear and oscillatory measurements, where a large viscosity (and elastic modulus) increase coincides with hydrate formation. Since temperature and pressure affect the thermodynamic stability of hydrates these are particular key variables that need to be tuned for this system.

  4. Determination of the heat of hydride formation/decomposition by high-pressure differential scanning calorimetry (HP-DSC).

    PubMed

    Rongeat, Carine; Llamas-Jansa, Isabel; Doppiu, Stefania; Deledda, Stefano; Borgschulte, Andreas; Schultz, Ludwig; Gutfleisch, Oliver

    2007-11-22

    Among the thermodynamic properties of novel materials for solid-state hydrogen storage, the heat of formation/decomposition of hydrides is the most important parameter to evaluate the stability of the compound and its temperature and pressure of operation. In this work, the desorption and absorption behaviors of three different classes of hydrides are investigated under different hydrogen pressures using high-pressure differential scanning calorimetry (HP-DSC). The HP-DSC technique is used to estimate the equilibrium pressures as a function of temperature, from which the heat of formation is derived. The relevance of this procedure is demonstrated for (i) magnesium-based compounds (Ni-doped MgH2), (ii) Mg-Co-based ternary hydrides (Mg-CoHx) and (iii) Alanate complex hydrides (Ti-doped NaAlH4). From these results, it can be concluded that HP-DSC is a powerful tool to obtain a good approximation of the thermodynamic properties of hydride compounds by a simple and fast study of desorption and absorption properties under different pressures.

  5. Incidence and risk factors of postoperative sore throat after endotracheal intubation in Korean patients.

    PubMed

    Lee, Jin Young; Sim, Woo Seog; Kim, Eun Sung; Lee, Sangmin M; Kim, Duk Kyung; Na, Yu Ri; Park, Dahye; Park, Hue Jung

    2017-04-01

    Objective To investigate the incidence of postoperative sore throat (POST) in Korean patients undergoing general anaesthesia with endotracheal intubation and to assess potential risk factors. Methods This prospective study enrolled patients who underwent all types of elective surgical procedures with endotracheal intubation and general anaesthesia. The patients were categorized into group S (those with a POST) or group N (those without a POST). The demographic, clinical and anaesthetic characteristics of each group were compared. Results This study enrolled 207 patients and the overall incidence of POST was 57.5% ( n = 119). Univariate analysis revealed that significantly more patients in group S had a cough at emergence and hoarseness in the postanaesthetic care unit compared with group N. Receiver operating characteristic curve analysis showed that an intracuff pressure ≥17 cmH2O was associated with POST. Multivariate analysis identified an intracuff pressure ≥17 cmH2O and cough at emergence as risk factors for POST. At emergence, as the intracuff pressure over ≥17 cmH2O increased, the incidence of hoarseness increased. Conclusions An intracuff pressure ≥17 cmH2O and a cough at emergence were risk factors for POST in Korean patients. Intracuff monitoring during anaesthesia and a smooth emergence are needed to prevent POST.

  6. Influence of the Gas Pressure on Single-wall Carbon Nanotubes Formation

    NASA Technical Reports Server (NTRS)

    Hinkov, I.; Farhat, S.; Scott, C. D.

    2005-01-01

    Experiments and modeling have been performed to predict the effect of gas pressure on species distribution and nanotube growth rate under specific conditions of synthesis of singlewall carbon nanotubes (SWCNTs) by arc discharge. Numerical results were compared with experiments in order to find a consistent correlation between the nanotube growth and the pressure. We used argon and helium as buffer gases with a total pressure varied between 0.1 and 1 bar. We experimentally observed that both the anode erosion rate and the Brunauer-Emmett-Teller (BET) surface area of the as produced nanotube soot material are very sensitive to the total gas pressure in the reactor

  7. Cenosphere formation from heavy fuel oil: a numerical analysis accounting for the balance between porous shells and internal pressure

    NASA Astrophysics Data System (ADS)

    Reddy, Vanteru M.; Rahman, Mustafa M.; Gandi, Appala N.; Elbaz, Ayman M.; Schrecengost, Robert A.; Roberts, William L.

    2016-01-01

    Heavy fuel oil (HFO) as a fuel in industrial and power generation plants ensures the availability of energy at economy. Coke and cenosphere emissions from HFO combustion need to be controlled by particulate control equipment such as electrostatic precipitators, and collection effectiveness is impacted by the properties of these particulates. The cenosphere formation is a function of HFO composition, which varies depending on the source of the HFO. Numerical modelling of the cenosphere formation mechanism presented in this paper is an economical method of characterising cenosphere formation potential for HFO in comparison to experimental analysis of individual HFO samples, leading to better control and collection. In the present work, a novel numerical model is developed for understanding the global cenosphere formation mechanism. The critical diameter of the cenosphere is modelled based on the balance between two pressures developed in an HFO droplet. First is the pressure (Prpf) developed at the interface of the liquid surface and the inner surface of the accumulated coke due to the flow restriction of volatile components from the interior of the droplet. Second is the pressure due to the outer shell strength (PrC) gained from van der Walls energy of the coke layers and surface energy. In this present study it is considered that when PrC ≥ Prpf the outer shell starts to harden. The internal motion in the shell layer ceases and the outer diameter (DSOut) of the shell is then fixed. The entire process of cenosphere formation in this study is analysed in three phases: regression, shell formation and hardening, and post shell hardening. Variations in pressures during shell formation are analysed. Shell (cenosphere) dimensions are evaluated at the completion of droplet evaporation. The rate of fuel evaporation, rate of coke formation and coke accumulation are analysed. The model predicts shell outer diameters of 650, 860 and 1040 µm, and inner diameters are 360, 410

  8. "Real-time" core formation experiments using X-ray tomography at high pressure and temperature

    NASA Astrophysics Data System (ADS)

    Watson, H. C.; Anzures, B.; Yu, T.; Wang, Y.

    2015-12-01

    The process of differentiation is a defining moment in a planet's history. Direct observation of this process at work is impossible in our solar system because it was complete within the first few tens of millions of years. Geochemical and geophysical evidence points to magma ocean scenarios to explain differentiation of large planets such as Earth. Smaller planets and planetesimals likely never achieved the high temperatures necessary for wide scale melting. In these smaller bodies, silicates may have only partially melted, or not melted at all. Furthermore, isotopic signatures in meteorites suggest that some planetesimals differentiated within just a few million years. Achieving efficient core segregation on this rapid timescale is difficult, particularly in a solid or semi-solid silicate matrix. Direct measurements of metallic melt migration velocities have been difficult due to experimental limitations and most previous work has relied on geometric models based on 2-D observations in quenched samples. We have employed a relatively new technique of in-situ, high pressure, high temperature, X-ray micro-tomography coupled with 3-D numerical simulations to evaluate the efficiency of melt percolation in metal/silicate systems. From this, we can place constraints on the timing of core formation in early solar system bodies. Mixtures of olivine and KLB-1 peridotite and up to 12 vol% FeS were pre-synthesized to achieve an initial equilibrium microstructure of silicate and sulfide. The samples were then were then pressed again to ~2GPa, and heated to ~1300°C to collect X-ray tomography images as the partially molten samples were undergoing shear deformation. The reconstructed 3-D images of melt distribution were used as the input for lattice Boltzmann simulations of fluid flow through the melt network and calculations of permeability and melt migration velocity. Our in-situ x-ray tomography results are complemented by traditional 2-D image analysis and high

  9. Biogenic amine formation and nitrite reactions in meat batter as affected by high-pressure processing and chilled storage.

    PubMed

    Ruiz-Capillas, C; Aller-Guiote, P; Carballo, J; Colmenero, F Jiménez

    2006-12-27

    Changes in biogenic amine formation and nitrite depletion in meat batters as affected by pressure-temperature combinations (300 MPa/30 min/7, 20, and 40 degrees C), cooking process (70 degrees C/30 min), and storage (54 days/2 degrees C) were studied. Changes in residual nitrite concentration in raw meat batters were conditioned by the temperature and not by the pressure applied. Cooking process decreased (P < 0.05) the residual nitrite concentration in all samples. High-pressure processing and cooking treatment increased (P < 0.05) the nitrate content. Whereas protein-bound nitrite concentration decreased with pressure processing, no effect was observed with the heating process of meat batters. High-pressure processing conditions had no effect on the rate of residual nitrite loss throughout the storage. The application of high pressure decreased (P < 0.05) the concentration of some biogenic amines (tyramine, agmatine, and spermine). Irrespective of the high processing conditions, generally, throughout storage biogenic amine levels did not change or increased, although quantitatively this effect was not very important.

  10. Interpretation of in-situ pressure and flow measurements of the Salado Formation at the Waste Isolation Pilot Plant

    SciTech Connect

    Howarth, S.M.; Peterson, E.W.; Lagus, P.L.; Lie, K.; Finley, S.J.; Nowak, E.J.

    1991-01-01

    This paper describes preliminary interpretation of in-situ pressure and flow measurements of the Salado Formation at the Waste Isolation Pilot Plant (WIPP). The WIPP facility is located 660 m underground in the Salado, a bedded salt deposit. Shut-in pressure tests were conducted prior to, and subsequent to, the mining of a circular drift in order to evaluate excavation effects on pore pressure, permeability, and host rock heterogeneity. Borehole deformation was measured during these tests and used to correct for changes in the test region volume due to salt creep effects. Preliminary pre-excavation results indicate that the flow properties of this layered host rock are heterogeneous. Resulting pore pressures range from 1 to 14 MPa and permeabilities range from below measurable to about 1 nanodarcy. Normalized borehole diameter change rates were between {minus}4 and 63 microstrains/day. Shut-in pressures and borehole diameters in all test boreholes were affected by the excavation of Room Q coincident with the advances of the boring machine. Preliminary results from post-excavation test results show decreased pore pressures compared to pre-excavation values.

  11. Biogenic amines formation in high-pressure processed pike flesh (Esox lucius) during storage.

    PubMed

    Křížek, Martin; Matějková, Kateřina; Vácha, František; Dadáková, Eva

    2014-05-15

    The effects of vacuum packaging followed by high pressure processing on the shelf-life of fillets of pike (Esox lucius) were examined. Samples were pressure-treated at 300 and 500 MPa and stored at 3.5 and 12 °C for up to 70 days. The content of eight biogenic amines (putrescine, cadaverine, spermidine, spermine, histamine, tyramine, tryptamine and phenylethylamine) were determined. Putrescine showed very good correspondence with the level of applied pressure and organoleptic properties. Polyamines spermidine and spermine did not show statistically significant changes with the level of applied pressure and the time of storage. Increased cadaverine and tyramine contents were found in samples with good sensory signs, stored for longer time and/or kept at 12 °C, thus indicating the loss of freshness. Tryptamine and phenylethylamine were not detected in pressure-treated samples kept at 3.5 °C. Histamine was not detected in samples of good quality.

  12. On Porosity Formation in Metal Matrix Composites Made with Dual-Scale Fiber Reinforcements Using Pressure Infiltration Process

    NASA Astrophysics Data System (ADS)

    Etemadi, Reihaneh; Pillai, Krishna M.; Rohatgi, Pradeep K.; Hamidi, Sajad Ahmad

    2015-05-01

    This is the first such study on porosity formation phenomena observed in dual-scale fiber preforms during the synthesis of metal matrix composites (MMCs) using the gas pressure infiltration process. In this paper, different mechanisms of porosity formation during pressure infiltration of Al-Si alloys into Nextel™ 3D-woven ceramic fabric reinforcements (a dual-porosity or dual-scale porous medium) are studied. The effect of processing conditions on porosity content of the ceramic fabric infiltrated by the alloys through the gas PIP (PIP stands for "Pressure Infiltration Process" in which liquid metal is injected under pressure into a mold packed with reinforcing fibers.) is investigated. Relative density (RD), defined as the ratio of the actual MMC density and the density obtained at ideal 100 pct saturation of the preform, was used to quantify the overall porosity. Increasing the infiltration temperature led to an increase in RD due to reduced viscosity of liquid metal and enhanced wettability leading to improved feedability of the liquid metal. Similarly, increasing the infiltration pressure led to enhanced penetration of fiber tows and resulted in higher RD and reduced porosity. For the first time, the modified Capillary number ( Ca*), which is found to predict formation of porosity in polymer matrix composites quite well, is employed to study porosity in MMCs made using PIP. It is observed that in the high Ca* regime which is common in PIP, the overall porosity shows a strong downward trend with increasing Ca*. In addition, the effect of matrix shrinkage on porosity content of the samples is studied through using a zero-shrinkage Al-Si alloy as the matrix; usage of this alloy as the matrix led to a reduction in porosity content.

  13. Effect of Microcurrent Stimulation on Delayed-Onset Muscle Soreness: A Double-Blind Comparison

    PubMed Central

    Allen, Jennifer D.; Mattacola, Carl G.; Perrin, David H.

    1999-01-01

    Objective: To examine the efficacy of microcurrent electrical neuromuscular stimulation (MENS) treatment on pain and loss of range of motion (ROM) associated with delayed-onset muscle soreness (DOMS). Design and Setting: We assigned subjects to 1 of 2 groups. Group 1 received treatment with microcurrent stimulation (200 μA, 30 Hz, for 10 minutes, then 100 μA, 0.3 Hz, for 10 minutes) 24, 48, and 72 hours after DOMS induction. Group 2 served as a sham group and was treated using a machine altered by the manufacturer so that no current could flow through the electrodes. Subjects: DOMS was induced in the biceps brachii of the nondominant arm of 18 subjects (3 males, 15 females: age = 20.33 ± 2.3 years, ht = 170.81 ± 7.3 cm, wt = 69.61 ± 13.1 kg). Dominance was defined as the arm used by the subject to throw a ball. Measurements: Subjective pain and active elbow extension ROM were evaluated before and after treatment each day. Two methods were used to assess pain: constant pressure using a weighted Orthoplast sphere and full elbow extension to the limit of pain tolerance. Subjective pain was measured with a graphic rating scale and active elbow extension ROM using a standard, plastic, double-armed goniometer. Three repeated-measures ANOVAs (between-subjects variable was group, within- subjects variables were day and test) were used to assess ROM and pain scores for the 2 groups. Results: We found no significant difference in the measurement of subjective pain scores or elbow extension ROM when the MENS group was compared with the sham group. Conclusions: Our results indicate that the MENS treatment, within the parameters used for this experiment, was not effective in reducing the pain or loss of ROM associated with delayed-onset muscle soreness. PMID:16558582

  14. The nursing rounds system: effect of patient's call light use, bed sores, fall and satisfaction level.

    PubMed

    Saleh, Bassem S; Nusair, Hussam; Al Zubadi, Nariman; Al Shloul, Shams; Saleh, Usama

    2011-06-01

    The nursing round system (NRS) means checking patients on an hourly basis during the A (0700-2200 h) shift and once every 2 h during the B (2200-0700 h) by the assigned nursing staff. The overall goal of this prospective study is to implement an NRS in a major rehabilitation centre-Sultan Bin Abdulaziz Humanitarian City-in the Riyadh area of the Kingdom of Saudi Arabia. The purposes of this study are to measure the effect of the NRS on: (i) the use of patient call light; (ii) the number of incidences of patients' fall; (iii) the number of incidences of hospital-acquired bed sores; and (iv) the level of patients' satisfaction. All patients hospitalized in the male stroke unit will be involved in this study. For the period of 8 weeks (17 December 2009-17 February 2010) All Nursing staff on the unit will record each call light and the patient's need. Implementation of the NRS would start on 18 February 2010 and last for 8 weeks, until 18 April 2010. Data collected throughout this period will be compared with data collected during the 8 weeks period immediately preceding the implementation of the NRS (17 December 2009-17 February 2010) in order to measure the impact of the call light use. The following information were collected on all subjects involved in the study: (i) the Demographic Information Form; (ii) authors' developed NRS Audit Form; (iii) Patient Call Light Audit Form; (iv) Patient Fall Audit Record; (v) Hospital-Acquired Bed Sores Audit Form; and (vi) hospital developed Patient Satisfaction Records. The findings suggested that a significant reduction on the use of call bell (P < 0.001), a significant reduction of fall incidence (P < 0.01) while pressure ulcer reduced by 50% before and after the implementation of NRS. Also, the implementation of NRS increased patient satisfaction by 7/5 (P < 0.05).

  15. Effect of microcurrent stimulation on delayed-onset muscle soreness: a double-blind comparison.

    PubMed

    Allen, J D; Mattacola, C G; Perrin, D H

    1999-10-01

    To examine the efficacy of microcurrent electrical neuromuscular stimulation (MENS) treatment on pain and loss of range of motion (ROM) associated with delayed-onset muscle soreness (DOMS). We assigned subjects to 1 of 2 groups. Group 1 received treatment with microcurrent stimulation (200 muA, 30 Hz, for 10 minutes, then 100 muA, 0.3 Hz, for 10 minutes) 24, 48, and 72 hours after DOMS induction. Group 2 served as a sham group and was treated using a machine altered by the manufacturer so that no current could flow through the electrodes. DOMS was induced in the biceps brachii of the nondominant arm of 18 subjects (3 males, 15 females: age = 20.33 +/- 2.3 years, ht = 170.81 +/- 7.3 cm, wt = 69.61 +/- 13.1 kg). Dominance was defined as the arm used by the subject to throw a ball. Subjective pain and active elbow extension ROM were evaluated before and after treatment each day. Two methods were used to assess pain: constant pressure using a weighted Orthoplast sphere and full elbow extension to the limit of pain tolerance. Subjective pain was measured with a graphic rating scale and active elbow extension ROM using a standard, plastic, double-armed goniometer. Three repeated-measures ANOVAs (between-subjects variable was group, within- subjects variables were day and test) were used to assess ROM and pain scores for the 2 groups. We found no significant difference in the measurement of subjective pain scores or elbow extension ROM when the MENS group was compared with the sham group. Our results indicate that the MENS treatment, within the parameters used for this experiment, was not effective in reducing the pain or loss of ROM associated with delayed-onset muscle soreness.

  16. New insights in the formation of silanol defects in silicalite-1 by water intrusion under high pressure.

    PubMed

    Karbowiak, Thomas; Saada, Mohamed-Ali; Rigolet, Séverinne; Ballandras, Anthony; Weber, Guy; Bezverkhyy, Igor; Soulard, Michel; Patarin, Joël; Bellat, Jean-Pierre

    2010-10-07

    The "water-silicalite-1" system is known to act as a molecular spring. The successive intrusion-extrusion cycles of liquid water in small crystallites (6 × 3 × 0.5 μm(3)) of hydrophobic silicalite-1 were studied by volumetric and calorimetric techniques. The experiments displayed a decrease of the intrusion pressure between the first intrusion-extrusion cycle and the consecutive ones, whereas the extrusion pressures remained unchanged. However, neither XRD studies nor SEM observations revealed any structural and morphological modifications of silicalite-1 at the long-range order. Such a shift in the value of the intrusion pressure after the first water intrusion-extrusion cycle is attributed to the creation of silanol groups during the first water intrusion. Detailed FTIR and solid-state NMR spectroscopic characterizations provided a molecular evidence of chemical modification of zeolite framework with the formation of local silanol defects created by the breaking of siloxane bonds.

  17. Pain reduction and treatment of sore nipples in nursing mothers.

    PubMed

    Cadwell, Karin; Turner-Maffei, Cynthia; Blair, Anna; Brimdyr, Kajsa; Maja McInerney, Zoë

    2004-01-01

    Health-promotion goals include increasing the duration of breastfeeding because of its irrefutable advantages to the mother and baby, society, and the environment. However, many mothers experience painful, sore nipples during breastfeeding and stop nursing before they intended (Livingstone & Stringer, 1999). The experimental trial described in this paper randomized 94 breastfeeding women with sore nipples into three treatment groups. Midwives practicing in hospitals in Latvia assessed the participants' breastfeeding practices, then gave the mothers individualized education and corrective interventions using a guided documentation form, the Lactation Assessment Tool (LATtrade mark). In addition, two groups were instructed to use commercial products on their breasts and nipples: breast shells and lanolin cream for one group, and glycerin gel therapy for the other. Nipple pain during breastfeeding was rated by the mothers on a 5-point verbal descriptor scale at each visit, and pain at the start of treatment was compared to pain at the last visit. Analysis of variance (using Fisher's Exact Test) determined that no significant differences existed between the groups: F(2, 86) = 1.34, p > .05. Almost all of the mothers experienced nipple healing, as assessed by the midwife. Mothers in the glycerin gel group were more satisfied with their treatment method, but this finding was not statistically significant. The results of this study indicate that effective care and perinatal education for nursing mothers with sore nipples should include assessment of breastfeeding positioning and latch-on, as well as education and corrective interventions using a guidance tool, whether or not commercial preparations are used.

  18. Pain Reduction and Treatment of Sore Nipples in Nursing Mothers

    PubMed Central

    Cadwell, Karin; Turner-Maffei, Cynthia; Blair, Anna; Brimdyr, Kajsa; Maja McInerney, Zoë

    2004-01-01

    Health-promotion goals include increasing the duration of breastfeeding because of its irrefutable advantages to the mother and baby, society, and the environment. However, many mothers experience painful, sore nipples during breastfeeding and stop nursing before they intended (Livingstone & Stringer, 1999). The experimental trial described in this paper randomized 94 breastfeeding women with sore nipples into three treatment groups. Midwives practicing in hospitals in Latvia assessed the participants' breastfeeding practices, then gave the mothers individualized education and corrective interventions using a guided documentation form, the Lactation Assessment Tool (LAT™). In addition, two groups were instructed to use commercial products on their breasts and nipples: breast shells and lanolin cream for one group, and glycerin gel therapy for the other. Nipple pain during breastfeeding was rated by the mothers on a 5-point verbal descriptor scale at each visit, and pain at the start of treatment was compared to pain at the last visit. Analysis of variance (using Fisher's Exact Test) determined that no significant differences existed between the groups: F(2, 86) = 1.34, p > .05. Almost all of the mothers experienced nipple healing, as assessed by the midwife. Mothers in the glycerin gel group were more satisfied with their treatment method, but this finding was not statistically significant. The results of this study indicate that effective care and perinatal education for nursing mothers with sore nipples should include assessment of breastfeeding positioning and latch-on, as well as education and corrective interventions using a guidance tool, whether or not commercial preparations are used. PMID:17273373

  19. Oxygen partial pressure dependence of surface space charge formation in donor-doped SrTiO3

    NASA Astrophysics Data System (ADS)

    Andrä, Michael; Dvořák, Filip; Vorokhta, Mykhailo; Nemšák, Slavomír; Matolín, Vladimír; Schneider, Claus M.; Dittmann, Regina; Gunkel, Felix; Mueller, David N.; Waser, Rainer

    2017-05-01

    In this study, we investigated the electronic surface structure of donor-doped strontium titanate. Homoepitaxial 0.5 wt. % donor-doped SrTiO3 thin films were analyzed by in situ near ambient pressure X-ray photoelectron spectroscopy at a temperature of 770 K and oxygen pressures up to 5 mbar. Upon exposure to an oxygen atmosphere at elevated temperatures, we observed a rigid binding energy shift of up to 0.6 eV towards lower binding energies with respect to vacuum conditions for all SrTiO3 core level peaks and the valence band maximum with increasing oxygen pressure. The rigid shift is attributed to a relative shift of the Fermi energy towards the valence band concomitant with a negative charge accumulation at the surface, resulting in a compensating electron depletion layer in the near surface region. Charge trapping effects solely based on carbon contaminants are unlikely due to their irreversible desorption under the given experimental conditions. In addition, simple reoxygenation of oxygen vacancies can be ruled out as the high niobium dopant concentration dominates the electronic properties of the material. Instead, the negative surface charge may be provided by the formation of cation vacancies or the formation of charged oxygen adsorbates at the surface. Our results clearly indicate a pO2-dependent surface space charge formation in donor-doped SrTiO3 in oxidizing conditions.

  20. Influence of ambient pressure on the hole formation in laser deep drilling

    NASA Astrophysics Data System (ADS)

    Döring, S.; Richter, S.; Heisler, F.; Ullsperger, T.; Tünnermann, A.; Nolte, S.

    2013-09-01

    We investigate the temporal evolution of the hole depth and shape for percussion drilling at different ambient pressure conditions. Deep drilling is performed in silicon as target material by ultrashort laser pulses at 1030 nm and a duration of 8 ps. Simultaneously, the backlit silhouette of the hole is imaged perpendicular to the drilling direction. While typical process phases like depth development and shape evolution are very similar for atmospheric pressure down to vacuum conditions (10-2 mbar), the ablation rate in the initial process phase is significantly increased for reduced pressure. The number of pulses till the stop of the drilling process also increases by a pressure reduction and exceeds drilling at atmospheric conditions by two orders of magnitude for a pressure of ca. 10-2 mbar. Accordingly, the maximum achievable hole depth is more than doubled. We attribute this behavior to an enlarged mean free path for ablation products at reduced pressure and therefore lower or no deposition of particles inside the hole capillary under vacuum conditions while debris fills the hole already after a few thousand pulses at atmospheric pressure. This is supported by scanning electron cross section images of the holes.

  1. The effect of ram-pressure stripping and starvation on the star formation properties of cluster galaxies

    NASA Astrophysics Data System (ADS)

    Boselli, A.; Boissier, S.; Cortese, L.; Gavazzi, G.

    2009-12-01

    We have combined UV to radio centimetric observations of resolved galaxies in the Virgo cluster with multizone, chemo-spectrophotometric models of galaxy evolution especially tailored to take into account the effects of the cluster environment (ram pressure stripping and starvation). This exercise has shown that anemic spirals with truncated radial profiles of the gas component and of the young stellar populations, typical in rich clusters of galaxies, have been perturbed by a recent (˜100 Myr) ram pressure stripping event induced by their interaction with the cluster intergalactic medium. Starvation is not able to reproduce the observed truncated radial profiles. Both ram pressure and starvation induce a decrease of the stellar surface brightness of the perturbed disc, and thus can hardly be invoked to explain the formation of lenticular galaxies inhabiting rich clusters, which are characterised by higher surface brightnesses than early type spirals of similar luminosity. In dwarfs the ram pressure stripping event is so efficient to totally remove their gas thus stopping on short time scales (<2 Gyr) their star formation activity. Low luminosity star forming discs can be transformed in dE galaxies.

  2. Acute sinusitis and sore throat in primary care.

    PubMed

    Del Mar, Chris

    2016-08-01

    Sore throat and acute sinusitis are not straightforward diagnoses. Trying to guess the responsible pathogen may not be the best approach. Being guided by empirical evidence may be more useful. It suggests some, but very few, benefits for antibiotics. This has to be balanced with some, but few, harms from antibiotics, including diarrhoea, rash and thrush. Prescribers should also be aware of the risk of antibiotic resistance for the individual, as well as for the population as a whole. GPs should explain the evidence for the benefits and the harms of antibiotics to patients within a shared decision-making framework.

  3. Buffer arrangement with back flushing of a quartz pressure transducer in a formation testing device

    SciTech Connect

    Gilbert, G.J.

    1993-08-03

    For use with a pressure sensor located in a sensor chamber in a sonde wherein the pressure sensor forms measurements of ambient pressure, an apparatus is described which comprises an elongate flow path from said sensor chamber to a source of fluid to be measured and wherein said fluid flow path comprises a passage within the threads of first and second threaded sonde components threaded together to define a helical flow path, wherein said helical flow path comprises first and second helical flow path segments serially connected.

  4. Active CO2 Reservoir Management: A Strategy for Controlling Pressure, CO2 and Brine Migration in Saline-Formation CCS

    NASA Astrophysics Data System (ADS)

    Buscheck, T. A.; Sun, Y.; Hao, Y.; Court, B.; Celia, M. A.; Wolery, T.; Tompson, A. F.; Aines, R. D.; Friedmann, J.

    2010-12-01

    CO2 capture and sequestration (CCS) in deep geological formations is regarded as a promising means of lowering the amount of CO2 emitted to the atmosphere and thereby mitigate global warming. The most promising systems for CCS are depleted oil reservoirs, particularly those suited to CO2-based Enhanced Oil Recovery (CCS-EOR), and deep saline formations, both of which are well separated from the atmosphere. For conventional, industrial-scale, saline-formation CCS, pressure buildup can have a limiting effect on CO2 storage capacity. To address this concern, we analyze Active CO2 Reservoir Management (ACRM), which combines brine extraction and residual-brine reinjection with CO2 injection, comparing it with conventional saline-formation CCS. We investigate the influence of brine extraction on pressure response and CO2 and brine migration using the NUFT code. By extracting brine from the lower portion of the storage formation, from locations progressively further from the center of injection, we can counteract buoyancy that drives CO2 to the top of the formation, which is useful in dipping formations. Using “push-pull” manipulation of the CO2 plume, we expose less of the caprock seal to CO2 and more of the storage formation to CO2, with more of the formation utilized for trapping mechanisms. Plume manipulation can also counteract the influence of heterogeneity. We consider the impact of extraction ratio, defined as net extracted brine volume (extraction minus reinjection) divided by injected CO2 volume. Pressure buildup is reduced with increasing extraction ratio, which reduces CO2 and brine migration, increases CO2 storage capacity, and reduces other risks, such as leakage up abandoned wells, caprock fracturing, fault activation, and induced seismicity. For a 100-yr injection period, a 10-yr delay in brine extraction does not diminish the magnitude of pressure reduction. Moreover, it is possible to achieve pressure management with just a few brine-extraction wells

  5. Durability of SRP Waste Glass - Effects of Pressure and Formation of Surface Layers

    SciTech Connect

    Wicks, G.G.

    2001-10-17

    This report discusses results of an assessment of pressure at anticipated storage temperature on the chemical durability of Savannah River Plant waste glass. Surface interactions were also examined and corrosion mechanisms discussed.

  6. Barometric pressure transient testing applications at the Nevada Test Site: formation permeability analysis. Final report

    SciTech Connect

    Hanson, J.M.

    1984-12-01

    The report evaluates previous investigations of the gas permeability of the rock surrounding emplacement holes at the Nevada Test Site. The discussion sets the framework from which the present uncertainty in gas permeability can be overcome. The usefulness of the barometric pressure testing method has been established. Flow models were used to evaluate barometric pressure transients taken at NTS holes U2fe, U19ac and U20ai. 31 refs., 103 figs., 18 tabs. (ACR)

  7. Abiotic Formation of Valine Peptides Under Conditions of High Temperature and High Pressure

    NASA Astrophysics Data System (ADS)

    Furukawa, Yoshihiro; Otake, Tsubasa; Ishiguro, Takato; Nakazawa, Hiromoto; Kakegawa, Takeshi

    2012-12-01

    We investigated the oligomerization of solid valine and the stabilities of valine and valine peptides under conditions of high temperature (150-200 °C) and high pressure (50-150 MPa). Experiments were performed under non-aqueous condition in order to promote dehydration reaction. After prolonged exposure of monomeric valine to elevated temperatures and pressures, the products were analyzed by liquid chromatography mass spectrometry comparing their retention times and masses. We identified linear peptides that ranged in size from dimer to hexamer, as well as a cyclic dimer. Previous studies that attempted abiotic oligomerization of valine in the absence of a catalyst have never reported valine peptides larger than a dimer. Increased reaction temperature increased the dissociative decomposition of valine and valine peptides to products such as glycine, β-alanine, ammonia, and amines by processes such as deamination, decarboxylation, and cracking. The amount of residual valine and peptide yields was greater at higher pressures at a given temperature, pressure, and reaction time. This suggests that dissociative decomposition of valine and valine peptides is reduced by pressure. Our findings are relevant to the investigation of diagenetic processes in prebiotic marine sediments where similar pressures occur under water-poor conditions. These findings also suggest that amino acids, such as valine, could have been polymerized to peptides in deep prebiotic marine sediments within a few hundred million years.

  8. Polymerization of cyanoacetylene under pressure: Formation of carbon nitride polymers and bulk structures

    NASA Astrophysics Data System (ADS)

    Khazaei, Mohammad; Liang, Yunye; Venkataramanan, Natarajan S.; Kawazoe, Yoshiyuki

    2012-02-01

    High-pressure phase transitions of polar and nonpolar molecular structures of cyanoacetylene (HC3N) are studied by using first-principles simulations at constant pressure. In both polar and nonpolar crystals, at pressure ˜20 GPa, the cyanoacetylene molecules are interconnected together and form polyacrylonitrile (PA) polymers. At pressure ˜30 GPa, PA polymers are transformed to polymers with fused pyridine rings (FPR's). The individual geometrical structures of PA and FPR polymers obtained from polar and nonpolar molecular crystals of cyanoacetylene are identical, but their stacking is different. At pressures above 40 GPa, the FPR polymers are interconnected together and new three-dimensional (3D) carbon nitride systems are formed. At ambient pressure, the long-length PA and FPR polymers are metallic, and the created 3D structures are an insulator with energy band gaps around 2.85 eV. The electron transport characteristics of FPR polymers with different lengths are investigated at finite biases by using the nonequilibrium Green's function technique combined with density functional theory (DFT) by connecting the polymers to gold electrodes. The results show that FPR polymers have negative differential resistance behavior. Our time-dependent DFT calculations reveal that FPR polymers can absorb light in the visible region. From our results, it is expected that the FPR polymers will be a good material for optoelectronic applications.

  9. Cold sore susceptibility gene-1 genotypes affect the expression of herpes labialis in unrelated human subjects.

    PubMed

    Kriesel, John D; Bhatia, Amiteshwar; Thomas, Alun

    2014-01-01

    Our group has recently described a gene on human chromosome 21, the Cold Sore Susceptibility Gene-1 (CSSG-1, also known as C21orf91), which may confer susceptibility to frequent cold sores in humans. We present here a genotype-phenotype analysis of CSSG-1 in a new, unrelated human population. Seven hundred fifty-eight human subjects were enrolled in a case/control Cold Sore Study. CSSG-1 genotyping, herpes simplex virus 1 (HSV1) serotyping, demographic and phenotypic data was available from 622 analyzed subjects. Six major alleles (H1-H6) were tested for associations with each of the self-reported phenotypes. The statistical analysis was adjusted for age, sex and ethnicity. Genotype-phenotype associations were analyzed from 388 HSV1-seropositive subjects. There were significant CSSG-1 haplotype effects on annual cold sore outbreaks (P=0.006), lifetime cold sores (P=0.012) and perceived cold sore severity (P=0.012). There were relatively consistent trends toward protection from frequent and severe cold sores among those with the H3 or H5/6 haplotypes, whereas those with H1, H2, and H4 haplotypes tended to have more frequent and more severe episodes. Different alleles of the newly described gene CSSG-1 affect the expression of cold sore phenotypes in this new, unrelated human population, confirming the findings of the previous family-based study.

  10. 21 CFR 201.315 - Over-the-counter drugs for minor sore throats; suggested warning.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 4 2011-04-01 2011-04-01 false Over-the-counter drugs for minor sore throats... AND HUMAN SERVICES (CONTINUED) DRUGS: GENERAL LABELING Specific Labeling Requirements for Specific Drug Products § 201.315 Over-the-counter drugs for minor sore throats; suggested warning. The Food and...

  11. An unusual case of a sore throat and otalgia in a 4-year-old boy.

    PubMed

    Siupšinskienė, Nora; Padervinskis, Evaldas; Poškienė, Lina; Endeley, Nganjo; Vaitkus, Saulius

    2012-01-01

    A sore throat, otalgia, and snoring are the common symptoms seen in children presenting to an otorhinolaryngological clinic. Sometimes, however, these symptoms may be suggestive of an aggressive malignancy. We present a rare case of Burkitt's lymphoma of the tonsil in a young child, which initially manifested as a sore throat and otalgia.

  12. Convergent evidence for construct validity of a 7-point likert scale of lower limb muscle soreness.

    PubMed

    Impellizzeri, Franco M; Maffiuletti, Nicola A

    2007-11-01

    The aim of this study was to examine the construct validity of the 7-point Likert scale of muscle soreness, assessing its relationship with Visual Analogue Scale (VAS). An additional aim was to examine its sensitivity as measure of symptom of eccentric-contraction muscle damage. Correlational study. Self-administered questionnaires collected in field setting. Twenty-six soccer players. 4-week preseason training camp, which included high-intensity plyometric training sessions. Players self-reported the perceived muscle soreness of the lower limbs using the VAS (criterion measure) and the 7-point Likert scale of muscle soreness. Significant individual correlations were found between the 2 muscle soreness scales (mean r=0.80+/-0.07; range, 0.65 to 0.94). The correlation using the pooled data was 0.81. No significant muscle soreness scale x time interaction was found for standardized measures of muscle soreness (P=0.98). The main factor for time (24, 48, 72, and 96 hours after the first plyometric training session) was significant (P=0.0001). Effect sizes for the changes in the Likert and VAS absolute scores during the first 96 hours were similar (partial eta=0.13). The results of this study provide further convergent evidence for the construct validity of the 7-point Likert scale of muscle soreness. The 2 scales showed similar sensitivity to muscle soreness caused by eccentric contractions during the first 96 hours after plyometric exercises.

  13. Homoeopathy for delayed onset muscle soreness: a randomised double blind placebo controlled trial.

    PubMed Central

    Vickers, A J; Fisher, P; Smith, C; Wyllie, S E; Lewith, G T

    1997-01-01

    OBJECTIVE: To pilot a model for determining whether a homoeopathic medicine is superior to placebo for delayed onset muscle soreness (DOMS). DESIGN: Randomised double blind placebo controlled trial. SETTING: Physiotherapy department of a homoeopathic hospital. SUBJECTS: Sixty eight healthy volunteers (average age 30; 41% men) undertook a 10 minute period of bench stepping carrying a small weight and were randomised to a homoeopathic medicine or placebo. OUTCOME MEASURES: Mean muscle soreness in the five day period after the exercise test, symptom free days, maximum soreness score, days to no soreness, days on medication. RESULTS: The difference between group means was 0.17 in favour of placebo with 95% confidence intervals +/- 0.50. Similar results were found for other outcome measures. CONCLUSION: The study did not find benefit of the homoeopathic remedy in DOMS. Bench stepping may not be an appropriate model to evaluate the effects of a treatment on DOMS because of wide variation between subject soreness scores. PMID:9429007

  14. Hybrid Equation/Agent-Based Model of Ischemia-Induced Hyperemia and Pressure Ulcer Formation Predicts Greater Propensity to Ulcerate in Subjects with Spinal Cord Injury

    PubMed Central

    Solovyev, Alexey; Mi, Qi; Tzen, Yi-Ting; Brienza, David; Vodovotz, Yoram

    2013-01-01

    Pressure ulcers are costly and life-threatening complications for people with spinal cord injury (SCI). People with SCI also exhibit differential blood flow properties in non-ulcerated skin. We hypothesized that a computer simulation of the pressure ulcer formation process, informed by data regarding skin blood flow and reactive hyperemia in response to pressure, could provide insights into the pathogenesis and effective treatment of post-SCI pressure ulcers. Agent-Based Models (ABM) are useful in settings such as pressure ulcers, in which spatial realism is important. Ordinary Differential Equation-based (ODE) models are useful when modeling physiological phenomena such as reactive hyperemia. Accordingly, we constructed a hybrid model that combines ODEs related to blood flow along with an ABM of skin injury, inflammation, and ulcer formation. The relationship between pressure and the course of ulcer formation, as well as several other important characteristic patterns of pressure ulcer formation, was demonstrated in this model. The ODE portion of this model was calibrated to data related to blood flow following experimental pressure responses in non-injured human subjects or to data from people with SCI. This model predicted a higher propensity to form ulcers in response to pressure in people with SCI vs. non-injured control subjects, and thus may serve as novel diagnostic platform for post-SCI ulcer formation. PMID:23696726

  15. Hybrid equation/agent-based model of ischemia-induced hyperemia and pressure ulcer formation predicts greater propensity to ulcerate in subjects with spinal cord injury.

    PubMed

    Solovyev, Alexey; Mi, Qi; Tzen, Yi-Ting; Brienza, David; Vodovotz, Yoram

    2013-01-01

    Pressure ulcers are costly and life-threatening complications for people with spinal cord injury (SCI). People with SCI also exhibit differential blood flow properties in non-ulcerated skin. We hypothesized that a computer simulation of the pressure ulcer formation process, informed by data regarding skin blood flow and reactive hyperemia in response to pressure, could provide insights into the pathogenesis and effective treatment of post-SCI pressure ulcers. Agent-Based Models (ABM) are useful in settings such as pressure ulcers, in which spatial realism is important. Ordinary Differential Equation-based (ODE) models are useful when modeling physiological phenomena such as reactive hyperemia. Accordingly, we constructed a hybrid model that combines ODEs related to blood flow along with an ABM of skin injury, inflammation, and ulcer formation. The relationship between pressure and the course of ulcer formation, as well as several other important characteristic patterns of pressure ulcer formation, was demonstrated in this model. The ODE portion of this model was calibrated to data related to blood flow following experimental pressure responses in non-injured human subjects or to data from people with SCI. This model predicted a higher propensity to form ulcers in response to pressure in people with SCI vs. non-injured control subjects, and thus may serve as novel diagnostic platform for post-SCI ulcer formation.

  16. Investigation Of Adhesion Formation In New Stainless Steel Trim Spring Operated Pressure Relief Valves

    SciTech Connect

    Gross, Robert E.; Bukowski, Julia V.; Goble, William M.

    2013-04-16

    Examination of proof test data for new (not previously installed) stainless steel (SS) trim spring operated pressure relief valves (SOPRV) reveals that adhesions form between the seat and disc in about 46% of all such SOPRV. The forces needed to overcome these adhesions can be sufficiently large to cause the SOPRV to fail its proof test (FPT) prior to installation. Furthermore, a significant percentage of SOPRV which are found to FPT are also found to ''fail to open'' (FTO) meaning they would not relief excess pressure in the event of an overpressure event. The cases where adhesions result in FTO or FPT appear to be confined to SOPRV with diameters < 1 in and set pressures < 150 psig and the FTO are estimated to occur in 0.31% to 2.00% of this subpopulation of SS trim SOPRV. The reliability and safety implications of these finding for end-users who do not perform pre-installation testing of SOPRV are discussed.

  17. The effects of game and training loads on perceptual responses of muscle soreness in Australian football.

    PubMed

    Montgomery, Paul G; Hopkins, Will G

    2013-05-01

    Australian Football is an intense team sport played over ~120 min on a weekly basis. To determine the effects of game and training load on muscle soreness and the time frame of soreness dissipation, 64 elite Australian Football players (age 23.8 ± 1.8 y, height 183.9 ± 3.8 cm, weight 83.2 ± 5.0 kg; mean ± SD) recorded perceptions of muscle soreness, game intensity, and training intensity on scales of 1-10 on most mornings for up to 3 competition seasons. Playing and training times were also recorded in minutes. Data were analyzed with a mixed linear model, and magnitudes of effects on soreness were evaluated by standardization. All effects had acceptably low uncertainty. Game and training-session loads were 790 ± 182 and 229 ± 98 intensity-minutes (mean ± SD), respectively. General muscle soreness was 4.6 ± 1.1 units on d 1 postgame and fell to 1.9 ± 1.0 by d 6. There was a small increase in general muscle soreness (0.22 ± 0.07-0.50 ± 0.13 units) in the 3 d after high-load games relative to low-load games. Other soreness responses showed similar timelines and magnitudes of change. Training sessions made only small contributions to soreness over the 3 d after each session. Practitioners should be aware of these responses when planning weekly training and recovery programs, as it appears that game-related soreness dissipates after 3 d regardless of game load and increased training loads in the following week produce only small increases in soreness.

  18. Flurbiprofen microgranules for relief of sore throat: a randomised, double-blind trial

    PubMed Central

    Russo, Marc; Bloch, Mark; de Looze, Fred; Morris, Christopher; Shephard, Adrian

    2013-01-01

    Background Many people with sore throat seek, and are often inappropriately prescribed, antibiotics. Aim The objective of this study was to determine the analgesic efficacy of flurbiprofen 8.75 mg microgranules versus placebo. These microgranules are a possible alternative treatment for patients with sore throat due to upper respiratory tract infection (URTI). Design and setting Randomised, double-blind, placebo-controlled, multiple-dose study conducted at eight primary care sites in Australia. Method Participants with sore throat of onset within the past 4 days received either flurbiprofen 8.75 mg microgranules or non-medicated placebo microgranules. Throat soreness, difficulty in swallowing, sore throat pain intensity, sore throat relief, oral temperature, and treatment benefits were all assessed at regular intervals. Result Of 373 patients from eight centres, 186 received flurbiprofen 8.75 mg microgranules and 187 received placebo microgranules (intent-to-treat population). Throat soreness was significantly reduced over the first 2 hours after the first dose. Reductions in difficulty in swallowing were observed at all time points from 5 to 360 minutes after the first dose, after taking flurbiprofen microgranules versus placebo. Sore throat relief was also evident at 1 minute and lasted for at least 6 hours. The multiple-dose efficacy results showed reduction of difficulty in swallowing at the end of days 1–3 and sore throat relief at the end of day 1. Conclusion Microgranules containing flurbiprofen 8.75 mg provided fast and effective relief from sore throat due to URTI and represent an alternative treatment option to antibiotic therapy. PMID:23561694

  19. Dissociation of CH4 at high pressures and temperatures: diamond formation in giant planet interiors?

    PubMed

    Benedetti, L R; Nguyen, J H; Caldwell, W A; Liu, H; Kruger, M; Jeanloz, R

    1999-10-01

    Experiments using laser-heated diamond anvil cells show that methane (CH4) breaks down to form diamond at pressures between 10 and 50 gigapascals and temperatures of about 2000 to 3000 kelvin. Infrared absorption and Raman spectroscopy, along with x-ray diffraction, indicate the presence of polymeric hydrocarbons in addition to the diamond, which is in agreement with theoretical predictions. Dissociation of CH4 at high pressures and temperatures can influence the energy budgets of planets containing substantial amounts of CH4, water, and ammonia, such as Uranus and Neptune.

  20. Enhancing Magnesite Formation at Low Temperature and High CO2 Pressure: The Impact of Seed Crystals and Minor Components

    SciTech Connect

    Felmy, Andrew R.; Qafoku, Odeta; Arey, Bruce W.; Kovarik, Libor; Liu, Jia; Perea, Daniel E.; Ilton, Eugene S.

    2015-02-24

    The formation of magnesite was followed in aqueous solution containing initially added Mg(OH)2 equilibrated with supercritical carbon dioxide (90 atm pressure, 50°C) in the presence of introduced magnesite particles and minor components, Co(II). As expected, the introduction of magnesite particles accelerated the formation of magnesite from solution. However, the formation rate of magnesite was even greater when small concentrations of Co(II) were introduced, indicating that the increased rate of magnesite formation in the presence of Co(II) was not solely due to the addition of a growth promoting surface. Detailed analysis of the magnesite particles by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), and atom probe tomography (APT) revealed that the originally added Co(II) was concentrated in the center but also present throughout the growing magnesite particles. Addition of the Co(II) in different chemical forms (i.e. as solid phase CoCO3 or Co(OH)2) could alter the growth rate of magnesite depending upon the addition of bicarbonate to the starting solution. Geochemical modeling calculations indicate that this difference is related to the thermodynamic stability of these different phases in the initial solutions. More broadly, these results indicate that the presence of even small concentrations of foreign ions that form carbonate compounds with a similar structure as magnesite can be incorporated into the magnesite lattice, accelerating the formation of anhydrous carbonates in natural environments.

  1. A custom-made silicon mold for pressure therapy to ear keloids.

    PubMed

    Yigit, B; Yazar, M; Alyanak, A; Guven, E

    2009-11-01

    Keloids are raised reddish nodules that develop at the site of an injury. They are characterized histologically by an abundance of fibroblasts, thick collagen bundles, and ground substance. Auricular keloid formation is a known complication of ear piercing. Many types of treatments have been described for auricular keloids.Pressure therapy in combination with surgery, corticosteroid injection, or both is widely used to manage and prevent hypertrophic scarring. Many pressure devices and procedures have been developed. However, all of them are designed for the earlobe region. If a keloid grows in the posterior auricular region, none of the devices described in the literature will be effective. The authors developed a custom-made silicon ear mold that covers whole ear. With this mold, pressure can be applied homogeneously to the lobule and cartilaginous region, which the other devices described in the literature cannot affect. The preparation technique includes making the negative cast mold of the patient's ear, creating the positive cast mold from the negative cast mold, and forming the negative silicon mold from the positive cast. After all the processes, a silicon sheet has been designed according to the region needing to be pressurized. The designed silicon sheet is applied to the region, followed by placement of the silicon mold. A simple tennis head band can be used to stabilize the silicon cast. If the keloid extends to the posterior auricular region, pressurizing with clips or other devices described previously will be difficult. Application of pressure to the cartilaginous auricle needs custom-made devices. At this point, a pressure sore caused by a device applied to the ear is the most important problem. To prevent the ear from developing a pressure sore, the device should press to whole area homogeneously. For this reason, the device applied for pressure therapy to the ear must be custom made.

  2. High-temperature- and high-pressure-induced formation of the Laves-phase compound XeS2

    NASA Astrophysics Data System (ADS)

    Yan, Xiaozhen; Chen, Yangmei; Xiang, Shikai; Kuang, Xiaoyu; Bi, Yan; Chen, Haiyan

    2016-06-01

    We explore the reactivity of xenon with sulfur under high pressure, using unbiased structure searching techniques combined with first-principles calculations, which identify a stable XeS2 compound crystallized in a Laves phase with hypercoordinated (16-fold) Xe at 191 GPa and 0 K. Taking the thermal effects into account, we find that increasing the temperature could further stabilize it. The formation of XeS2 is a consequence of pressure-induced charge transfer from Xe to S atoms and the delocalization of Xe 5 p and S 3 p electrons. Meanwhile, the stabilization into a Laves phase of XeS2 is the result of delocalized chemical bonding and the need for optimum structure packing. The present discussion of the formation mechanism in XeS2 is general, and conclusions can be used to understand the formation of other Laves-phase compounds and the Xe chemistry that allows closed-shell Xe to participate in chemical reactions.

  3. First Evidence of Rh Nano-Hydride Formation at Low Pressure.

    PubMed

    Zlotea, Claudia; Oumellal, Yassine; Msakni, Mariem; Bourgon, Julie; Bastide, Stéphane; Cachet-Vivier, Christine; Latroche, Michel

    2015-07-08

    Rh-based nanoparticles supported on a porous carbon host were prepared with tunable average sizes ranging from 1.3 to 3.0 nm. Depending on the vacuum or hydrogen environment during thermal treatment, either Rh metal or hydride is formed at nanoscale, respectively. In contrast to bulk Rh that can form a hydride phase under 4 GPa pressure, the metallic Rh nanoparticles (∼2.3 nm) absorb hydrogen and form a hydride phase at pressure below 0.1 MPa, as evidenced by the presence of a plateau pressure in the pressure-composition isotherm curves at room temperature. Larger metal nanoparticles (∼3.0 nm) form only a solid solution with hydrogen under similar conditions. This suggests a nanoscale effect that drastically changes the Rh-H thermodynamics. The nanosized Rh hydride phase is stable at room temperature and only desorbs hydrogen above 175 °C. Within the present hydride particle size range (1.3-2.3 nm), the hydrogen desorption is size-dependent, as proven by different thermal analysis techniques.

  4. 21 CFR 880.5550 - Alternating pressure air flotation mattress.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... body pressure. The device is used to prevent and treat decubitus ulcers (bed sores). (b) Classification... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Alternating pressure air flotation mattress. 880... Personal Use Therapeutic Devices § 880.5550 Alternating pressure air flotation mattress. (a)...

  5. Double negative pressure for seroma treatment in trocanteric area.

    PubMed

    Calderon, Wilfredo L; Llanos, Sergio; Leniz, Patricio; Danilla, Stefan; Vielma, Rodrigo; Calderon, Daniel

    2009-12-01

    We report the use of topic negative pressure for seromas resulting from mobilization of tensor fascia lata miocutaneous flap in the trochanteric areas for pressure sores. In 5 consecutive patients we successfully treated seroma with the use of external and internal topic subatmospheric pressure.

  6. Magnesite formation from MgO and CO2 at the pressures and temperatures of Earth's mantle

    SciTech Connect

    Scott, Henry P.; Doczy, Vincent M.; Frank, Mark R.; Hasan, Maggie; Lin, Jung-Fu; Yang, Jing

    2013-08-02

    Magnesite (MgCO3) is an important phase for the carbon cycle in and out of the Earth’s mantle. Its comparably large P-T stability has been inferred for several years based on the absence of its decomposition in experiments. Here we report the first experimental evidence for synthesis of magnesite out of its oxide components (MgO and CO2) at P-T conditions relevant to the Earth’s mantle. Magnesite formation was observed in situ using synchrotron X-ray diffraction, coupled with laser-heated diamond-anvil cells (DACs), at pressures and temperatures of Earth’s mantle. Despite the existence of multiple high-pressure CO2 polymorphs, the magnesite-forming reaction was observed to proceed at pressures ranging from 5 to 40 GPa and temperatures between 1400 and 1800 K. No other pressure-quenchable materials were observed to form via the MgO + CO2 = MgCO3 reaction. This work further strengthens the notion that magnesite may indeed be the primary host phase for oxidized carbon in the deep Earth.

  7. Comparison of total body tissue interface pressure of specialized pressure-relieving mattresses.

    PubMed

    Hickerson, William L; Slugocki, George M; Thaker, Reuben L; Dunkan, Robert; Bishop, John F; Parks, Judy K

    2004-01-01

    The pressure-relieving ability of three specialized support surface mattresses was investigated and compared to a standard hospital mattress by measuring total body tissue interface pressure in a laboratory experiment designed to simulate clinical conditions predisposing to formation of pressure ulcers. Pressure ulcers are commonly seen in the elderly; in patients with trauma, burns, spinal cord injury, neurological deficits, peripheral vascular disease, and stroke; and in other patient groups with debilitating or emaciating illness. They represent from 4 to 29% of all hospital admissions. This study was undertaken to compare three different types of specialty beds to a standard hospital mattress in order to find a mattress that prevents the occurrence of pressure ulcers. The tested beds and mattresses were the Orthoderm Convertible II (Bio-Clinic Inc., Ontario, Canada) low air-loss mattress on a Stryker PMS (Stryker Inc., Kalamazoo, Michigan, USA) bed; the FluidAir Elite (KCI Inc., San Antonio, Texas, USA) air-fluidized bed; the Pegasus Airwave mattress (Pegasus Airwave Inc., Boca Raton, Florida, USA) on a Stryker PMS bed; and a standard hospital mattress on a Stryker PMS bed. The nineteen test subjects were all healthy with exclusion criteria of spinal cord injury, immobility, or other neurological or physical impairment. The Force Management System (Numotech Inc., Northridge, California, USA) was used to measure tissue interface pressure. The study data show that the Pegasus Airwave mattress total surface pressure values of the anatomical regions (total body, torso, hips) of the body are lower than those of the other three tested mattresses. The total body and hip pressure resulting from pressure maturation is significantly less on the Pegasus Airwave mattress than on to the hospital bed, the air-fluidized bed, and the low air-loss bed. The Pegasus Airwave mattress outperforms the other tested support surfaces by decreasing overall pressure. Therefore, the

  8. Effectiveness of using wearable vibration therapy to alleviate muscle soreness.

    PubMed

    Cochrane, Darryl J

    2017-03-01

    To examine the acute and short-term effect of a wearable vibration device following strenuous eccentric exercise of the elbow flexors. Physically active males (n = 13) performed vibration therapy (VT) and control following eccentric exercise. The arms were randomised and counterbalanced, separated by 14 days. 15 min of VT (120 Hz) was applied immediately and 24, 48, and 72 h after eccentric exercise while the contralateral arm performed no VT (control). Muscle (isometric and concentric) strength, range of motion, electromyography (EMG), muscle soreness and creatine kinase were taken pre-exercise, immediately and 24, 48, and 72 h post-eccentric exercise. Additionally, the acute effect of VT of muscle strength, range of motion, EMG, muscle soreness was also investigated immediately after VT. In the short-term VT was able to significantly reduce the level of biceps brachii pain at 24 h (p < 0.05) and 72 h (p < 0.01), enhance pain threshold at 48 h (p < 0.01) and 72 h (p < 0.01), improve range of motion at 24 h (p < 0.05), 48 h (p < 0.01) and 72 h (p < 0.01) and significantly (p < 0.05) reduced creatine kinase at 72 h compared to control. Acutely, following VT treatment muscle pain and range of motion significantly improved (p < 0.05) at 24 h post, 48 h post, and 72 h post but no significant changes in muscle strength and EMG were reported acutely or short-term. Acute and short-term VT attenuated muscle soreness, creatine kinase and improved range of motion; however, there was no improvement of muscle strength recovery compared to control following eccentric exercise of the elbow flexors.

  9. Delayed onset muscle soreness : treatment strategies and performance factors.

    PubMed

    Cheung, Karoline; Hume, Patria; Maxwell, Linda

    2003-01-01

    Delayed onset muscle soreness (DOMS) is a familiar experience for the elite or novice athlete. Symptoms can range from muscle tenderness to severe debilitating pain. The mechanisms, treatment strategies, and impact on athletic performance remain uncertain, despite the high incidence of DOMS. DOMS is most prevalent at the beginning of the sporting season when athletes are returning to training following a period of reduced activity. DOMS is also common when athletes are first introduced to certain types of activities regardless of the time of year. Eccentric activities induce micro-injury at a greater frequency and severity than other types of muscle actions. The intensity and duration of exercise are also important factors in DOMS onset. Up to six hypothesised theories have been proposed for the mechanism of DOMS, namely: lactic acid, muscle spasm, connective tissue damage, muscle damage, inflammation and the enzyme efflux theories. However, an integration of two or more theories is likely to explain muscle soreness. DOMS can affect athletic performance by causing a reduction in joint range of motion, shock attenuation and peak torque. Alterations in muscle sequencing and recruitment patterns may also occur, causing unaccustomed stress to be placed on muscle ligaments and tendons. These compensatory mechanisms may increase the risk of further injury if a premature return to sport is attempted.A number of treatment strategies have been introduced to help alleviate the severity of DOMS and to restore the maximal function of the muscles as rapidly as possible. Nonsteroidal anti-inflammatory drugs have demonstrated dosage-dependent effects that may also be influenced by the time of administration. Similarly, massage has shown varying results that may be attributed to the time of massage application and the type of massage technique used. Cryotherapy, stretching, homeopathy, ultrasound and electrical current modalities have demonstrated no effect on the alleviation of

  10. Influence of flowing helium gas on plasma plume formation in atmospheric pressure plasma

    SciTech Connect

    Yambe, Kiyoyuki; Konda, Kohmei; Ogura, Kazuo

    2015-05-15

    We have studied atmospheric pressure plasma generated using a quartz tube, helium gas, and a foil electrode by applying RF high voltage. The atmospheric pressure plasma in the form of a bullet is released as a plume into the atmosphere. The helium gas flowing out of quartz tube mixes with air, and the flow channel is composed of the regions of flowing helium gas and air. The plasma plume length is equivalent to the reachable distance of flowing helium gas. Although the amount of helium gas on the flow channel increases by increasing the inner diameter of quartz tube at the same gas flow velocity, the plasma plume length peaks at around 8 m/s of gas flow velocity, which is the result that a flow of helium gas is balanced with the amount of gas. The plasma plume is formed at the boundary region where the flow of helium gas is kept to the wall of the air.

  11. Kinetics of microstructure formation of high-pressure induced gel from a whey protein isolate

    NASA Astrophysics Data System (ADS)

    He, Jin-Song; Yang, Hongwei; Zhu, Wanpeng; Mu, Tai-Hua

    2010-03-01

    The kinetic process of pressure-induced gelation of whey protein isolate (WPI) solutions was studied using in situ light scattering. The relationship of the logarithm of scattered light intensity (I) versus time (t) was linear after the induced time and could be described by the Cahn-Hilliard linear theory. With increasing time, the scattered intensity deviated from the exponential relationship, and the time evolution of the scattered light intensity maximum Im and the corresponding wavenumber qm could be described in terms of the power-law relationship as Im~fβ and qm~f-α, respectively. These results indicated that phase separation occurred during the gelation of WPI solutions under high pressure.

  12. Experimental study of fractal clusters formation from nanoparticles synthesized by atmospheric pressure plasma-enhanced chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Mishin, Maxim V.; Protopopova, Vera S.; Alexandrov, Sergey E.

    2014-11-01

    This paper presents the experimental results from the fractal structures formation from nanoparticles of silicone dioxide deposited on the silicon substrate surface. Nanoparticles are synthesized by atmospheric pressure plasma-enhanced chemical vapor deposition with the use of capacitively coupled radio frequency (13.56 MHz) discharge sustained in helium atmosphere. Tetraethoxysilane is chosen as the test precursor. Correlation between the morphology of obtained deposits and the process parameters is found. The capability of nanoparticles movement along the deposit surface in local near-surface electric field is demonstrated. The empirical model that satisfactorily explained the mechanism of fractal clusters formation from nanoparticles on the substrate surface is developed. The model indicates that the dynamics of deposit morphology variations is determined by two competing processes: electrical charge transfer by nanoparticles to the deposit surface and electrical charge running off over the surface under conditions of changeable conductivity of the deposit surface.

  13. Selective Formation of Trimethylene Carbonate (TMC): Atmospheric Pressure Carbon Dioxide Utilization

    PubMed Central

    Buckley, Benjamin R; Patel, Anish P; Wijayantha, K G Upul

    2015-01-01

    Carbon dioxide utilisation (CDU) is currently gaining increased interest due to the abundance of CO2 and its possible application as a C1 building block. We herein report the first example of atmospheric pressure carbon dioxide incorporation into oxetane to selectively form trimethylene carbonate (TMC), which is a significant challenge as TMC is thermodynamically less favoured than its corresponding co-polymer. PMID:26213485

  14. Rapid Association Reactions at Low Pressure: Impact on the Formation of Hydrocarbons on Titan

    NASA Astrophysics Data System (ADS)

    Vuitton, V.; Yelle, R. V.; Lavvas, P.; Klippenstein, S. J.

    2012-01-01

    Photochemical models of Titan's atmosphere predict that three-body association reactions are the main production route for several major hydrocarbons. The kinetic rate constants of these reactions strongly depend on density and are therefore only important in Titan's lower atmosphere. However, radiative association reactions do not depend on pressure. The possible existence of large rates at low density suggests that association reactions could significantly affect the chemistry of Titan's upper atmosphere and better constraints for them are required. The kinetic parameters of these reactions are extremely difficult to constrain by experimental measurements as the low pressure of Titan's upper atmosphere cannot be reproduced in the laboratory. However, in the recent years, theoretical calculations of kinetics parameters have become more and more reliable. We therefore calculated several radical-radical and radical-molecule association reaction rates using transition state theory. The calculations indicate that association reactions are fast even at low pressure for adducts having as few as four C atoms. These drastic changes have however only moderate consequences for Titan's composition. Locally, mole fractions can vary by as much as one order of magnitude but the column-integrated production and condensation rates of hydrocarbons change only by a factor of a few. We discuss the impact of these results for the organic chemistry. It would be very interesting to check the impact of these new rate constants on other environments, such as giant and extrasolar planets as well as the interstellar medium.

  15. RAPID ASSOCIATION REACTIONS AT LOW PRESSURE: IMPACT ON THE FORMATION OF HYDROCARBONS ON TITAN

    SciTech Connect

    Vuitton, V.; Klippenstein, S. J. E-mail: yelle@lpl.arizona.edu E-mail: sjk@anl.gov

    2012-01-01

    Photochemical models of Titan's atmosphere predict that three-body association reactions are the main production route for several major hydrocarbons. The kinetic rate constants of these reactions strongly depend on density and are therefore only important in Titan's lower atmosphere. However, radiative association reactions do not depend on pressure. The possible existence of large rates at low density suggests that association reactions could significantly affect the chemistry of Titan's upper atmosphere and better constraints for them are required. The kinetic parameters of these reactions are extremely difficult to constrain by experimental measurements as the low pressure of Titan's upper atmosphere cannot be reproduced in the laboratory. However, in the recent years, theoretical calculations of kinetics parameters have become more and more reliable. We therefore calculated several radical-radical and radical-molecule association reaction rates using transition state theory. The calculations indicate that association reactions are fast even at low pressure for adducts having as few as four C atoms. These drastic changes have however only moderate consequences for Titan's composition. Locally, mole fractions can vary by as much as one order of magnitude but the column-integrated production and condensation rates of hydrocarbons change only by a factor of a few. We discuss the impact of these results for the organic chemistry. It would be very interesting to check the impact of these new rate constants on other environments, such as giant and extrasolar planets as well as the interstellar medium.

  16. High-pressure processing decelerates lipolysis and formation of volatile compounds in ovine milk blue-veined cheese.

    PubMed

    Calzada, J; Del Olmo, A; Picon, A; Gaya, P; Nuñez, M

    2013-01-01

    Enzyme-rich cheeses are prone to over-ripening during refrigerated storage. Blue-veined cheeses fall within this category because of the profuse growth of Penicillium roqueforti in their interior, which results in the production of highly active proteinases, lipases, and other enzymes responsible for the formation of a great number of flavor compounds. To control the excessive formation of free fatty acids (FFA) and volatile compounds, blue-veined cheeses were submitted to high-pressure processing (HPP) at 400 or 600 MPa on d 21, 42, or 63 after manufacture. Cheeses were ripened for 30d at 10°C and 93% relative humidity, followed by 60 d at 5°C, and then held at 3°C until d 360. High-pressure processing influenced the concentrations of acetic acid and short-chain, medium-chain, and long-chain FFA. The effect was dependent on treatment conditions (pressure level and cheese age at the time of treatment). The lowest concentrations of acetic acid and FFA were recorded for cheeses treated at 600 MPa on d 21; these cheeses showed the lowest esterase activity values. Acetic acid and all FFA groups increased during ripening and refrigerated storage. The 102 volatile compounds detected in cheese belonged to 10 chemical groups (5 aldehydes, 12 ketones, 17 alcohols, 12 acids, 35 esters, 9 hydrocarbons, 5 aromatic compounds, 3 nitrogen compounds, 3 terpenes, and 1 sulfur compound). High-pressure processing influenced the levels of 97 individual compounds, whereas 68 individual compounds varied during refrigerated storage. Total concentrations of all groups of volatile compounds were influenced by HPP, but only ketones, acids, esters, and sulfur compounds varied during refrigerated storage. The lowest total concentrations for most groups of volatile compounds were recorded for the cheese pressurized at 600 MPa on d 21. A principal component analysis combining total concentrations of groups of FFA and volatile compounds discriminated cheeses by age and by the pressure level

  17. Galaxies undergoing ram-pressure stripping: the influence of the bulge on morphology and star formation rate

    NASA Astrophysics Data System (ADS)

    Steinhauser, D.; Haider, M.; Kapferer, W.; Schindler, S.

    2012-08-01

    Aims: We investigate the influence of stellar bulges on the star formation and morphology of disc galaxies that suffer from ram pressure. Several tree-SPH (smoothed particle hydrodynamics) simulations have been carried out to study the dependence of the star formation rate on the mass and size of a stellar bulge. In addition, different strengths of ram pressure and different alignments of the disc with respect to the intra-cluster medium (ICM) are applied. Methods: The simulations were carried out with the combined N-body/hydrodynamic code GADGET-2 with radiative cooling and a recipe for star formation. The same galaxy with different bulge sizes was used to accomplish 31 simulations with varying inclination angles and surrounding gas densities of 10-27g cm-3 and 10-28g cm-3. For all the simulations a relative velocity of 1000 km s-1 for the galaxies and an initial gas temperature for the ICM of 107K were applied. Besides galaxies flying edge-on and face-on through the surrounding gas, various disc tilt angles in between were used. To allow a comparison, the galaxies with the different bulges were also evolved in isolation to contrast the star formation rates. Furthermore, the influence of different disc gas mass fractions has been investigated. Results: As claimed in previous works, when ram pressure is acting on a galaxy, the star formation rate (SFR) is enhanced and rises up to four times with increasing ICM density compared to galaxies that evolve in isolation. However, a bulge suppresses the SFR when the same ram pressure is applied. Consequently, fewer new stars are formed because the SFR can be lowered by up to 2M⊙ yr-1. Furthermore, the denser the surrounding gas, the more interstellar medium (ISM) is stripped. While at an ICM density of 10-28g cm-3 about 30% of the ISM is stripped, the galaxy is almost completely (more than 90%) stripped when an ICM density of 10-27g cm-3 is applied. But again, a bulge prevents the stripping of the ISM and reduces the

  18. Surface pressure affects B-hordein network formation at the air-water interface in relation to gastric digestibility.

    PubMed

    Yang, Jingqi; Huang, Jun; Zeng, Hongbo; Chen, Lingyun

    2015-11-01

    Protein interfacial network formation under mechanical pressure and its influence on degradation was investigated at molecular level using Langmuir-Blodgett B-hordein monolayer as a 2D model. Surface properties, such as surface pressure, dilatational and shear rheology and the surface pressure--area (π-A) isotherm, of B-hordein at air-water interface were analyzed by tensiometer, rheometer and a Langmuir-Blodgett trough respectively. B-Hordein conformation and orientation under different surface pressures were determined by polarization modulation-infrared reflection absorption spectroscopy (PM-IRRAS). The interfacial network morphology was observed by atomic force microscopy (AFM). B-Hordein could reduce the air-water surface tension rapidly to ∼ 45 mN/m and form a solid-like network with high rheological elasticity and compressibility at interface, which could be a result of interactions developed by intermolecular β-sheets. The results also revealed that B-hordein interfacial network switched from an expanded liquid phase to a solid-like film with increasing compression pressure. The orientation of B-hordein was parallel to the surface when in expended liquid phase, whereas upon compression, the hydrophobic repetitive region tilted away from water phase. When compressed to 30 mN/m, a strong elastic network was formed at the interface, and it was resistant to a harsh gastric-like environment of low pH and pepsin. This work generated fundamental knowledge, which suggested the potential to design B-hordein stabilized emulsions and encapsulations with controllable digestibility for small intestine targeted delivery of bioactive compounds. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Ultrasound Findings of Delayed-Onset Muscle Soreness.

    PubMed

    Longo, Victor; Jacobson, Jon A; Fessell, David P; Mautner, Kenneth

    2016-11-01

    The purpose of this series was to retrospectively characterize the ultrasound findings of delayed-onset muscle soreness (DOMS). The Institutional Review Board approved our study, and informed consent was waived. A retrospective search of radiology reports using the key phrase "delayed-onset muscle soreness" and key word "DOMS" from 2001 to 2015 and teaching files was completed to identify cases. The sonograms were reviewed by 3 fellowship-trained musculoskeletal radiologists by consensus. Sonograms were retrospectively characterized with respect to echogenicity (hypoechoic, isoechoic, or hyperechoic), distribution of muscle involvement, and intramuscular pattern (focal versus diffuse and well defined versus poorly defined). Images were also reviewed for muscle enlargement, fluid collection, muscle fiber disruption, and increased flow on color or power Doppler imaging. There were a total of 6 patients identified (5 male and 1 female). The average age was 22 years (range, 7-44 years). Of the 6 patients, there were a total of 11 affected muscles in 7 extremities (1 bilateral case). The involved muscles were in the upper extremity: triceps brachii in 27% (3 of 11), biceps brachii in 18% (2 of 11), brachialis in 18% (2 of 11), brachioradialis in 18% (2 of 11), infraspinatus in 9% (1 of 11), and deltoid in 9% (1 of 11). On ultrasound imaging, the abnormal muscle was hyperechoic in 100% (11 of 11), well defined in 73% (8 of 11), poorly defined in 27% (3 of 11), diffuse in 73% (8 of 11), and focal in 27% (3 of 11). Increased muscle size was found in 82% (9 of 11) and minimal hyperemia in 87.5% (7 of 8). The ultrasound findings of DOMS include hyperechoic involvement of an upper extremity muscle, most commonly appearing well defined and diffuse with increased muscle size and minimal hyperemia.

  20. Moist Heat or Dry Heat for Delayed Onset Muscle Soreness

    PubMed Central

    Petrofsky, Jerrold; Berk, Lee; Bains, Gurinder; Khowailed, Iman Akef; Hui, Timothy; Granado, Michael; Laymon, Mike; Lee, Haneul

    2013-01-01

    Background Heat is commonly used in physical therapy following exercise induced delayed onset muscle soreness (DOMS). Most heat modalities used in a clinical setting for DOMS are only applied for 5 to 20 minutes. This minimal heat exposure causes little, if any, change in deep tissue temperature. For this reason, long duration dry chemical heat packs are used at home to slowly and safely warm tissue and reduce potential heat damage while reducing pain associated from DOMS. Clinically, it has been shown that moist heat penetrates deep tissue faster than dry heat. Therefore, in home use chemical moist heat may be more efficacious than dry heat to provide pain relief and reduce tissue damage following exercise DOMS. However, chemical moist heat only lasts for 2 hours compared to the 8 hours duration of chemical dry heat packs. The purpose of this study was to compare the beneficial effect of dry heat versus moist heat on 100 young subjects after exercise induce DOMS. Methods One hundred subjects exercised for 15 minutes accomplishing squats. Before and for 3 days after, strength, muscle soreness, tissue resistance, and the force to passively move the knee were recorded. Heat and moist heat were applied in different groups either immediately after exercise or 24 hours later. Results The research results of this study showed that immediate application of heat, either dry (8 hours application) or moist (2 hours application), had a similar preservation of quadriceps muscle strength and muscle activity. Results also revealed that the greatest pain reduction was shown after immediate application of moist heat. Never the less, immediate application of dry heat had a similar effect but to a lesser extent. Conclusion It should be noted that moist heat had not only similar benefits of dry heat but in some cases enhanced benefits, and with only 25% of the time of application of the dry heat. PMID:24171053

  1. Surface-induced pressure-gradient formation in a gas mixture

    NASA Astrophysics Data System (ADS)

    Vaksman, Michael A.

    1993-07-01

    We predict a previously unidentified phenomenon, the drift of a gas mixture arising from the difference in masses of resonant and buffer molecules scattered by a cell-wall surface at velocity-selective excitation. The transverse profile of the mixture flux and pressure drop along the cell with closed ends are calculated. Recent experimental results [R. W. M. Hoogeveen, R. J. van der Oord, and L. J. F. Hermans, in 2 Proceedings of the 15th International Symposium on Rarefied Gas Dynamics, Grado, Italy (Teubner, Stuttgart, 1986), Vol. 1, p. 321] are discussed in connection with the phenomenon.

  2. Formation and stability of D-limonene organogel-based nanoemulsion prepared by a high-pressure homogenizer.

    PubMed

    Zahi, Mohamed Reda; Wan, Pingyu; Liang, Hao; Yuan, Qipeng

    2014-12-31

    D-limonene organogel-based nanoemulsion was prepared by high-pressure homogenization technology. The organogelator type had a major role on the formation of the formulations, in which stearic acid has given nanoemulsions with the smallest droplet size. The surfactant type and concentration also had an appreciable effect on droplet formation, with Tween 80 giving a mean droplet diameter (d ≈ 112 nm) among a range of non-ionic surfactants (Tween 20, 40, 60, 80, and 85). In addition, high-pressure homogenization conditions played a key role in the nanoemulsion preparation. The stability of d-limonene organogel-based nanoemulsion was also investigated under two different temperatures (4 and 28 °C) through 2 weeks of storage. Results showed a good stability of the formulations, which is maybe due to the incorporation of D-limonene into the organogel prior to homogenization. This study may have a valuable contribution for the design and use of organogel-based nanoemulsion as a delivery system in food.

  3. Carbon dioxide storage in marine sediments - dissolution, transport and hydrate formation kinetics from high-pressure experiments

    NASA Astrophysics Data System (ADS)

    Bigalke, N. K.; Savy, J. P.; Pansegrau, M.; Aloisi, G.; Kossel, E.; Haeckel, M.

    2009-12-01

    By satisfying thermodynamic framework conditions for CO2 hydrate formation, pressures and temperatures of the deep marine environment are unique assets for sequestering CO2 in clathrates below the seabed. However, feasibility and safety of this storage option require an accurate knowledge of the rate constants governing the speed of physicochemical reactions following the injection of the liquefied gas into the sediments. High-pressure experiments designed to simulate the deep marine environment open the possibility to obtain the required parameters for a wide range of oceanic conditions. In an effort to constrain mass transfer coefficients and transport rates of CO2 in(to) the pore water of marine sediments first experiments were targeted at quantifying the rate of CO2 uptake by de-ionized water and seawater across a two-phase interface. The nature of the interface was controlled by selecting p and T to conditions within and outside the hydrate stability field (HSF) while considering both liquid and gaseous CO2. Concentration increase and hydrate growth were monitored by Raman spectroscopy. The experiments revealed anomalously fast transport rates of dissolved CO2 at conditions both inside and outside the HSF. While future experiments will further elucidate kinetics of CO2 transport and hydrate formation, these first results could have major significance to safety-related issues in the discussion of carbon storage in the marine environment.

  4. Microfluidic EDGE emulsification: the importance of interface interactions on droplet formation and pressure stability

    NASA Astrophysics Data System (ADS)

    Sahin, Sami; Bliznyuk, Olesya; Rovalino Cordova, Ana; Schroën, Karin

    2016-05-01

    The fact that interactions of components with interfaces can influence processes is well-known; e.g. deposit accumulation on heat exchangers and membrane fouling lead to additional resistances against heat and mass transfer, respectively. In microfluidic emulsification, the situation is even more complex. Component accumulation at the liquid/liquid interface is necessary for emulsion stability, while undesired at the solid/liquid interface where it may change wettability. For successful emulsification both aspects need to be controlled, and that is investigated in this paper for o/w emulsification with microfluidic EDGE devices. These devices were characterised previously, and can be used to detect small wettability changes through e.g. the pressure stability of the device. We used various oil/emulsifier combinations (alkanes, vegetable oil, surfactants and proteins) and related droplet size and operational pressure stability to component interactions with the solid surface and liquid interface. Surfactants with a strong interaction with glass always favour emulsification, while surfactants that have week interactions with the surface can be replaced by vegetable oil that interacts strongly with glass, resulting in loss of emulsification. Our findings clearly show that an appropriate combination of construction material and emulsion components is needed to achieve successful emulsification in microfluidic EDGE devices.

  5. Formation and characterization of hydrophobic glass surface treated by atmospheric pressure He/CH4 plasma

    NASA Astrophysics Data System (ADS)

    Noh, Sooryun; Youn Moon, Se

    2014-01-01

    Atmospheric pressure helium plasmas, generated in the open air by 13.56 MHz rf power, were applied for the glass surface wettability modification. The plasma gas temperature, measured by the spectroscopic method, was under 400 K which is low enough to treat the samples without thermal damages. The hydrophobicity of the samples determined by the water droplet contact angle method was dependent on the methane gas content and the plasma exposure time. Adding the methane gas by a small amount of 0.25%, the contact angle was remarkably increased from 10° to 83° after the 10 s plasma treatment. From the analysis of the treated surface and the plasma, it was shown that the deposition of alkane functional groups such as C-H stretch, CH2 bend, and CH3 bend was one of the contributing factors for the hydrophobicity development. In addition, the hydrophobic properties lasted over 2 months even after the single treatment. From the results, the atmospheric pressure plasma treatment promises the fast and low-cost method for the thermally-weak surface modification.

  6. Microfluidic EDGE emulsification: the importance of interface interactions on droplet formation and pressure stability

    PubMed Central

    Sahin, Sami; Bliznyuk, Olesya; Rovalino Cordova, Ana; Schroën, Karin

    2016-01-01

    The fact that interactions of components with interfaces can influence processes is well-known; e.g. deposit accumulation on heat exchangers and membrane fouling lead to additional resistances against heat and mass transfer, respectively. In microfluidic emulsification, the situation is even more complex. Component accumulation at the liquid/liquid interface is necessary for emulsion stability, while undesired at the solid/liquid interface where it may change wettability. For successful emulsification both aspects need to be controlled, and that is investigated in this paper for o/w emulsification with microfluidic EDGE devices. These devices were characterised previously, and can be used to detect small wettability changes through e.g. the pressure stability of the device. We used various oil/emulsifier combinations (alkanes, vegetable oil, surfactants and proteins) and related droplet size and operational pressure stability to component interactions with the solid surface and liquid interface. Surfactants with a strong interaction with glass always favour emulsification, while surfactants that have week interactions with the surface can be replaced by vegetable oil that interacts strongly with glass, resulting in loss of emulsification. Our findings clearly show that an appropriate combination of construction material and emulsion components is needed to achieve successful emulsification in microfluidic EDGE devices. PMID:27230981

  7. Stakeholders' views of recurrent sore throat, tonsillitis and their management: a qualitative interview study for the NAtional Trial of Tonsillectomy IN Adults (NATTINA Part 1).

    PubMed

    McSweeney, L A; Rousseau, N S; Wilson, J A; Wilkes, S; Haighton, C A

    2017-04-01

    To determine the impact of recurrent sore throats and tonsillitis in adults and stakeholder views of treatment pathways. Qualitative semistructured interview design reporting novel data from a feasibility study for a UK national trial of tonsillectomy in adults. Nine study sites linked to ear, nose and throat departments in National Health Service hospitals located across the United Kingdom. Fifteen patients, 11 general practitioners and 22 ear, nose and throat staff consented to in-depth interviews, which were analysed using a framework analysis approach. Views of stakeholder groups. Recurrent sore throats were reported to severely impact patients' family, work and social life. Ear, nose and throat staff stated that patients faced increasing barriers to secondary care service access. General practitioners were under pressure to reduce 'limited clinical value' surgical procedures. The findings from this study suggest that there is a disconnect between the attitudes of the stakeholders and the reality of recurrent sore throat, tonsillectomy procedures and service provision. More evidence for the role of tonsillectomy is needed from randomised controlled trials to determine whether it should continue to be ranked as a procedure of limited clinical effectiveness. © 2016 John Wiley & Sons Ltd.

  8. Biological CO2 conversion to acetate in subsurface coal-sand formation using a high-pressure reactor system

    PubMed Central

    Ohtomo, Yoko; Ijiri, Akira; Ikegawa, Yojiro; Tsutsumi, Masazumi; Imachi, Hiroyuki; Uramoto, Go-Ichiro; Hoshino, Tatsuhiko; Morono, Yuki; Sakai, Sanae; Saito, Yumi; Tanikawa, Wataru; Hirose, Takehiro; Inagaki, Fumio

    2013-01-01

    Geological CO2 sequestration in unmineable subsurface oil/gas fields and coal formations has been proposed as a means of reducing anthropogenic greenhouse gasses in the atmosphere. However, the feasibility of injecting CO2 into subsurface depends upon a variety of geological and economic conditions, and the ecological consequences are largely unpredictable. In this study, we developed a new flow-through-type reactor system to examine potential geophysical, geochemical and microbiological impacts associated with CO2 injection by simulating in-situ pressure (0–100 MPa) and temperature (0–70°C) conditions. Using the reactor system, anaerobic artificial fluid and CO2 (flow rate: 0.002 and 0.00001 ml/min, respectively) were continuously supplemented into a column comprised of bituminous coal and sand under a pore pressure of 40 MPa (confined pressure: 41 MPa) at 40°C for 56 days. 16S rRNA gene analysis of the bacterial components showed distinct spatial separation of the predominant taxa in the coal and sand over the course of the experiment. Cultivation experiments using sub-sampled fluids revealed that some microbes survived, or were metabolically active, under CO2-rich conditions. However, no methanogens were activated during the experiment, even though hydrogenotrophic and methylotrophic methanogens were obtained from conventional batch-type cultivation at 20°C. During the reactor experiment, the acetate and methanol concentration in the fluids increased while the δ13Cacetate, H2 and CO2 concentrations decreased, indicating the occurrence of homo-acetogenesis. 16S rRNA genes of homo-acetogenic spore-forming bacteria related to the genus Sporomusa were consistently detected from the sandstone after the reactor experiment. Our results suggest that the injection of CO2 into a natural coal-sand formation preferentially stimulates homo-acetogenesis rather than methanogenesis, and that this process is accompanied by biogenic CO2 conversion to acetate. PMID

  9. Biological CO2 conversion to acetate in subsurface coal-sand formation using a high-pressure reactor system.

    PubMed

    Ohtomo, Yoko; Ijiri, Akira; Ikegawa, Yojiro; Tsutsumi, Masazumi; Imachi, Hiroyuki; Uramoto, Go-Ichiro; Hoshino, Tatsuhiko; Morono, Yuki; Sakai, Sanae; Saito, Yumi; Tanikawa, Wataru; Hirose, Takehiro; Inagaki, Fumio

    2013-01-01

    Geological CO2 sequestration in unmineable subsurface oil/gas fields and coal formations has been proposed as a means of reducing anthropogenic greenhouse gasses in the atmosphere. However, the feasibility of injecting CO2 into subsurface depends upon a variety of geological and economic conditions, and the ecological consequences are largely unpredictable. In this study, we developed a new flow-through-type reactor system to examine potential geophysical, geochemical and microbiological impacts associated with CO2 injection by simulating in-situ pressure (0-100 MPa) and temperature (0-70°C) conditions. Using the reactor system, anaerobic artificial fluid and CO2 (flow rate: 0.002 and 0.00001 ml/min, respectively) were continuously supplemented into a column comprised of bituminous coal and sand under a pore pressure of 40 MPa (confined pressure: 41 MPa) at 40°C for 56 days. 16S rRNA gene analysis of the bacterial components showed distinct spatial separation of the predominant taxa in the coal and sand over the course of the experiment. Cultivation experiments using sub-sampled fluids revealed that some microbes survived, or were metabolically active, under CO2-rich conditions. However, no methanogens were activated during the experiment, even though hydrogenotrophic and methylotrophic methanogens were obtained from conventional batch-type cultivation at 20°C. During the reactor experiment, the acetate and methanol concentration in the fluids increased while the δ(13)Cacetate, H2 and CO2 concentrations decreased, indicating the occurrence of homo-acetogenesis. 16S rRNA genes of homo-acetogenic spore-forming bacteria related to the genus Sporomusa were consistently detected from the sandstone after the reactor experiment. Our results suggest that the injection of CO2 into a natural coal-sand formation preferentially stimulates homo-acetogenesis rather than methanogenesis, and that this process is accompanied by biogenic CO2 conversion to acetate.

  10. Diagnostics and active species formation in an atmospheric pressure helium sterilization plasma source

    NASA Astrophysics Data System (ADS)

    Simon, A.; Anghel, S. D.; Papiu, M.; Dinu, O.

    2009-01-01

    Systematic spectroscopic studies and diagnostics of an atmospheric pressure radiofrequency (13.56 MHz) He plasma is presented. The discharge is an intrinsic part of the resonant circuit of the radiofrequency oscillator and was obtained using a monoelectrode type torch, at various gas flow-rates (0.1-6.0 l/min) and power levels (0-2 W). As function of He flow-rate and power the discharge has three developing stages: point-like plasma, spherical plasma and ellipsoidal plasma. The emission spectra of the plasma were recorded and investigated as function of developing stages, flow-rates and plasma power. The most important atomic and molecular components were identified and their evolution was studied as function of He flow-rate and plasma power towards understanding basic mechanisms occurring in this type of plasma. The characteristic temperatures (vibrational Tvibr, rotational Trot and excitation Texc) and the electron number density (ne) were determined.

  11. Star Formation in High Pressure, High Energy Density Environments: Laboratory Experiments of ISM Dust Analogs

    SciTech Connect

    van Breugel, W; Bajt, S; Bradley, J; Bringa, E; Dai, Z; Felter, T; Graham, G; Kucheyev, S; Torres, D; Tielens, A; Baragiola, R; Dukes, C; Loeffler, M

    2005-01-05

    Dust grains control the chemistry and cooling, and thus the gravitational collapse of interstellar clouds. Energetic particles, shocks and ionizing radiation can have a profound influence on the structure, lifetime and chemical reactivity of the dust, and therefore on the star formation efficiency. This would be especially important in forming galaxies, which exhibit powerful starburst (supernovae) and AGN (active galactic nucleus) activity. How dust properties are affected in such environments may be crucial for a proper understanding of galaxy formation and evolution. The authors present the results of experiments at LLNL which show that irradiation of the interstellar medium (ISM) dust analog forsterite (Mg{sub 2}SiO{sub 4}) with swift heavy ions (10 MeV Xe) and a large electronic energy deposition amorphizes its crystalline structure, without changing its chemical composition. From the data they predict that silicate grains in the ISM, even in dense and cold giant molecular clouds, can be amorphized by heavy cosmic rays (CR's). This might provide an explanation for the observed absence of crystalline dust in the ISM clouds of the Milky Way galaxy. This processing of dust by CR's would be even more important in forming galaxies and galaxies with active black holes.

  12. Formation of hydrocarbons on Titan: Impact of rapid association reactions at low pressure

    NASA Astrophysics Data System (ADS)

    Vuitton, V.; Yelle, R. V.; Lavvas, P.; Klippenstein, S. J.

    2011-10-01

    In the 1980's, Voyager revealed that complex organic molecules were present in Titan's atmosphere but the actual mechanisms leading to this rich chemistry were largely unknown. The recent Cassini results indicate that the chemistry ocurring in Titan's upper atmosphere is far more complex than anticipated. The detection of heavy positive and negative ions [13] reveals that much of the molecular growth occurs in the upper atmosphere rather than at lower altitudes [5, 12]. Photochemical models predict that three-body association reactions (A + B + M!AB + M) are the main production route for several hydrocarbons, including alkanes [2, 3]. The kinetic parameters of these reactions strongly depend on density and are therefore extremely difficult to constrain by experimental measurements as the low pressure of Titan's upper atmosphere cannot be reproduced in the laboratory. As a consequence, they have to be extrapolated outside the range of measurements, leading to high uncertainties. According to these extrapolations, three-body association reactions are only efficient in Titan's lower atmosphere. However, radiative association reactions (A + B ! AB + h) do not depend on pressure and can therefore still be efficient in the upper atmosphere. Unfortunately, they are largely uncharacterized and have consequently been neglected in photochemical models so far. Because of their potential importance at higher altitude, association reactions can have an important contribution to our understanding of molecular growth and better constraints for them are required. In the recent years, theoretical calculations of kinetics parameters have become more and more reliable [7]. We therefore performed ab initio transition state theory based master equation calculations for several radical-radical and radical-molecule association reactions. The computed kinetics parameters were included in our photochemical model of Titan. We present here the main results and discuss their impact for the

  13. Pilot study on the effect of grounding on delayed-onset muscle soreness.

    PubMed

    Brown, Dick; Chevalier, Gaétan; Hill, Michael

    2010-03-01

    The purpose of this pilot study was to determine whether there are markers that can be used to study the effects of grounding on delayed-onset muscle soreness (DOMS). Eight (8) healthy subjects were exposed to an eccentric exercise that caused DOMS in gastrocnemius muscles of both legs. Four (4) subjects were grounded with electrode patches and patented conductive sheets connected to the earth. Four (4) control subjects were treated identically, except that the grounding systems were not connected to the earth. Complete blood counts, blood chemistry, enzyme chemistry, serum and saliva cortisols, magnetic resonance imaging and spectroscopy and pain levels were taken at the same time of day before the eccentric exercise and 24, 48, and 72 hours afterwards. Parameters consistently differing by 10% or more, normalized to baseline, were considered worthy of further study. Parameters that differed by these criteria included white blood cell counts, bilirubin, creatine kinase, phosphocreatine/inorganic phosphate ratios, glycerolphosphorylcholine, phosphorylcholine, the visual analogue pain scale, and pressure measurements on the right gastrocnemius. In a pilot study, grounding the body to the earth alters measures of immune system activity and pain. Since this is the first intervention that appears to speed recovery from DOMS, the pilot provides a basis for a larger study.

  14. Pilot Study on the Effect of Grounding on Delayed-Onset Muscle Soreness

    PubMed Central

    Brown, Dick; Hill, Michael

    2010-01-01

    Abstract Objectives The purpose of this pilot study was to determine whether there are markers that can be used to study the effects of grounding on delayed-onset muscle soreness (DOMS). Design and subjects Eight (8) healthy subjects were exposed to an eccentric exercise that caused DOMS in gastrocnemius muscles of both legs. Four (4) subjects were grounded with electrode patches and patented conductive sheets connected to the earth. Four (4) control subjects were treated identically, except that the grounding systems were not connected to the earth. Outcome measures Complete blood counts, blood chemistry, enzyme chemistry, serum and saliva cortisols, magnetic resonance imaging and spectroscopy and pain levels were taken at the same time of day before the eccentric exercise and 24, 48, and 72 hours afterwards. Parameters consistently differing by 10% or more, normalized to baseline, were considered worthy of further study. Results Parameters that differed by these criteria included white blood cell counts, bilirubin, creatine kinase, phosphocreatine/inorganic phosphate ratios, glycerolphosphorylcholine, phosphorylcholine, the visual analogue pain scale, and pressure measurements on the right gastrocnemius. Conclusions In a pilot study, grounding the body to the earth alters measures of immune system activity and pain. Since this is the first intervention that appears to speed recovery from DOMS, the pilot provides a basis for a larger study. PMID:20192911

  15. Three dimensional simulations of pattern formation during high-pressure, freely localized microwave breakdown in air

    SciTech Connect

    Kourtzanidis, K. Boeuf, J. P.; Rogier, F.

    2014-12-15

    Recent experiments have demonstrated that a freely localized 100 GHz microwave discharge can propagate towards the microwave source with high speed, forming a complex pattern of self-organized filaments. We present three-dimensional simulations of the formation and propagation of such patterns that reveal more information on their nature and interaction with the electromagnetic waves. The developed three-dimensional Maxwell-plasma solver permits the study of different forms of incident field polarization. Results for linear and circular polarization of the wave are presented and comparisons with recent experiments show a good overall agreement. The three dimensional simulations provide a quantitative analysis of the parameters controlling the time and length scales of the strongly non-linear plasma dynamics and could be useful for potential microwave plasma applications such as aerodynamic flow and combustion control.

  16. Laser-driven formation of a high-pressure phase in amorphous silica

    SciTech Connect

    Salleo, Alberto; Taylor, Seth T.; Martin, Michael C.; Panero, Wendy R.; Jeanloz, Raymond; Genin, Francois Y.; Sands, Timothy

    2002-05-31

    A combination of electron diffraction and infrared reflectance measurements shows that synthetic silica transforms partially into stishovite under high-intensity (GW/cm2) laser irradiation, probably by the formation of a dense ionized plasma above the silica surface. During the transformation the silicon coordination changes from four-fold to six-fold and the silicon-oxygen bond changes from mostly covalent to mostly ionic, such that optical properties of the transformed material differ significantly from those of the original glass. This phase transformation offers one suitable mechanism by which laser-induced damage grows catastrophically once initiated, thereby dramatically shortening the service lifetime of optics used for high-power photonics applications such as inertial confinement fusion.

  17. Whole-Body Vibration While Squatting and Delayed-Onset Muscle Soreness in Women.

    PubMed

    Dabbs, Nicole C; Black, Christopher D; Garner, John

    2015-12-01

    Research into alleviating muscle pain and symptoms in individuals after delayed-onset muscle soreness (DOMS) has been inconsistent and unsuccessful in demonstrating a useful recovery modality. To investigate the effects of short-term whole-body vibration (WBV) on DOMS over a 72-hour period after a high-intensity exercise protocol. Randomized controlled clinical trial. University laboratory. Thirty women volunteered to participate in 4 testing sessions and were assigned randomly to a WBV group (n = 16; age = 21.0 ± 1.9 years, height = 164.86 ± 6.73 cm, mass = 58.58 ± 9.32 kg) or a control group (n = 14; age = 22.00 ± 1.97 years, height = 166.65 ± 8.04 cm, mass = 58.69 ± 12.92 kg). Participants performed 4 sets to failure of single-legged split squats with 40% of their body weight to induce muscle soreness in the quadriceps. The WBV or control treatment was administered each day after DOMS. Unilateral pressure-pain threshold (PPT), range of motion (ROM), thigh circumference, and muscle-pain ratings of the quadriceps were collected before and for 3 days after high-intensity exercise. Each day, we collected 3 sets of measures, consisting of 1 measure before the WBV or control treatment protocol (pretreatment) and 2 sets of posttreatment measures. We observed no interactions for PPT, thigh circumference, and muscle pain (P > .05). An interaction was found for active ROM (P = .01), with the baseline pretreatment measure greater than the measures at baseline posttreatment 1 through 48 hours posttreatment 2 in the WBV group. For PPT, a main effect for time was revealed (P < .05), with the measure at baseline pretreatment greater than at 24 hours pretreatment and all other time points for the vastus medialis, greater than 24 hours pretreatment through 48 hours posttreatment 2 for the vastus lateralis, and greater than 24 hours pretreatment and 48 hours pretreatment for the rectus femoris. For dynamic muscle pain, we observed a main effect for time (P < .001), with the

  18. Whole-Body Vibration While Squatting and Delayed-Onset Muscle Soreness in Women

    PubMed Central

    Dabbs, Nicole C.; Black, Christopher D.; Garner, John

    2015-01-01

    Context  Research into alleviating muscle pain and symptoms in individuals after delayed-onset muscle soreness (DOMS) has been inconsistent and unsuccessful in demonstrating a useful recovery modality. Objective  To investigate the effects of short-term whole-body vibration (WBV) on DOMS over a 72-hour period after a high-intensity exercise protocol. Design  Randomized controlled clinical trial. Setting  University laboratory. Patients or Other Participants  Thirty women volunteered to participate in 4 testing sessions and were assigned randomly to a WBV group (n = 16; age = 21.0 ± 1.9 years, height = 164.86 ± 6.73 cm, mass = 58.58 ± 9.32 kg) or a control group (n = 14; age = 22.00 ± 1.97 years, height = 166.65 ± 8.04 cm, mass = 58.69 ± 12.92 kg). Intervention(s)  Participants performed 4 sets to failure of single-legged split squats with 40% of their body weight to induce muscle soreness in the quadriceps. The WBV or control treatment was administered each day after DOMS. Main Outcome Measure(s)  Unilateral pressure-pain threshold (PPT), range of motion (ROM), thigh circumference, and muscle-pain ratings of the quadriceps were collected before and for 3 days after high-intensity exercise. Each day, we collected 3 sets of measures, consisting of 1 measure before the WBV or control treatment protocol (pretreatment) and 2 sets of posttreatment measures. Results  We observed no interactions for PPT, thigh circumference, and muscle pain (P > .05). An interaction was found for active ROM (P = .01), with the baseline pretreatment measure greater than the measures at baseline posttreatment 1 through 48 hours posttreatment 2 in the WBV group. For PPT, a main effect for time was revealed (P < .05), with the measure at baseline pretreatment greater than at 24 hours pretreatment and all other time points for the vastus medialis, greater than 24 hours pretreatment through 48 hours posttreatment 2 for the vastus lateralis, and greater than 24 hours

  19. Effects of ibuprofen on exercise-induced muscle soreness and indices of muscle damage.

    PubMed Central

    Donnelly, A E; Maughan, R J; Whiting, P H

    1990-01-01

    Thirty-two volunteers participated in a two-period crossover study in which ibuprofen was tested against an identical placebo for its effectiveness in reducing muscle soreness and damage after two bouts of downhill running. Subjective soreness, quadriceps isometric strength and isometric endurance time at 50 percent of maximum strength, serum activities of creatine kinase, lactate dehydrogenase and aspartate transaminase and serum levels of creatinine and urea were recorded at intervals up to 72 hours after exercise. Each downhill run produced muscle soreness, and a decline in muscle strength and 50 percent endurance time, although these parameters were unaffected by ibuprofen treatment. All serum parameters measured increased after both runs, but for the three enzymes this increase was smaller after the second run. Serum creatine kinase and urea levels were higher in the ibuprofen group after both runs. These results indicate that ibuprofen is not an appropriate treatment for delayed onset muscle soreness and damage. PMID:2078806