Distortion of Chain Conformation and Reduced Entanglement in Polymer-Graphene Oxide Nanocomposites.

We study the conformations of polymer chains in polymer-graphene oxide nanocomposites. We show that the chains have a reduced radius of gyration that is consistent with confinement at a solid interface in the melt, as is expected for well-dispersed, high aspect ratio nanoparticles that are much larger than the polymer coil size. We show that confinement of the polymer chains causes a corresponding reduction in interchain entanglements, and we calculate a contribution to the plateau modulus from the distorted polymer network via a simple scaling argument. Our results are a significant step forward in understanding how two-dimensional nanoparticles affect global material properties at low loadings.

After hospital: working with schools and families to support the long term needs of children with brain injuries.

Medical and rehabilitation systems care for children who sustain brain injuries. Their much needed services, however, are short in comparison with the long term needs of these children and their families. For the most part, it is schools and families who provide the long term supports to help children make the best outcomes and create a better quality of life. Professionals and families who develop collaborative models find that they can more effectively manage services for these children by carefully crafting Individual Education Plans (IEP's). Through the IEP process students' complex needs; the multiple transitions they experience; and their long term needs can be met.

The role of emergency medical services for children (EMSC) in the care of children with traumatic brain injuries.

This article highlights the role that Emergency Medical Services for Children (EMSC) can play in the continuum of care for children with traumatic brain injuries. Through national efforts by the EMSC, several initiatives and recommendations are proposed regarding the development of a coordinated system of care for children with special healthcare needs that includes children with traumatic brain injuries. In particular, EMSC is addressing the need for expanded emergency and trauma care services for children and methods of improving continuity among emergency, acute, rehabilitation, and community services to enhance better long-term outcomes for these children and their families. Other identified needs include: training and education of providers; resolving differences in language and philosophy that exist across disciplines; developing standards for family-centered care; and improving communication and service coordination for children with special healthcare needs.

Designing and implementing clinical pathways for children with traumatic brain injuries.

The growth of managed care, in particular, has made statements regarding the potential progress of children with traumatic brain injuries more and more necessary prior to admission. In addition, institutions and programs have been held responsible for documenting positive progress in a more systematic fashion than previously. Typically, clinical pathways are documented timetables describing progress and outcome in medical settings. This article will present rationale for the need to develop clinical pathways, what components and rehabilitation areas should be included, and how to implement such pathways. Specific aspects of pathways can be formulated to meet the needs and reflect the characteristics of children with traumatic brain injuries. Incorporating clinical pathways into school, community re-entry, and program evaluation will also be discussed. Pathways can be valuable tools in communicating with families, funders, and clinical staff, as well as tools for program evaluation.

Hand infections in the diabetic and the diabetic renal transplant recipient.

We present a series of 41 diabetic patients with severe tissue destruction and deformity secondary to hand infections. Thirty (73%) of the patients showed propagation of the infection to bone, tendons, or deep palmar spaces, and 26 of 41 (63%) required amputations. Sixty-three percent of the cultures were mixed; pure Staphylococcus aureus accounted for only 12%. Diabetics who were renal transplant recipients were at increased risk, with a 100% amputation rate and an average hospitalization of 41 days. Recommendations for management of diabetic hand infections are given to reduce the mortality and morbidity in these patients.

Elective cross-hand transfer: a case report with a five-year follow-up.

The elective free microvascular cross-hand transfer of the right hand to the left distal carpus was successfully performed in a 35-year old professional photographer. Traumatic loss of the left hand with preservation of a useful thumb and concomitant right upper extremity injury leaving the right hand with an amputated thumb, but paralyzed and insensate from a brachial plexus palsy 5 years before transfer, set the stage for such a reconstruction. Multiple immediate tendon transfers and primary nerve grafting provided for finger flexion and extension plus functional sensibility in this first reported case of an elective cross-hand microvascular transfer. Five years follow-up demonstrates useful and powerful flexion, and functional extension of digits in the reconstructed left hand and right upper extremity function has been improved with a below-elbow prosthesis.

Metacarpal fracture fixation with interosseous nylon suture in a patient with metal allergies.

The successful repair of two oblique metacarpal shaft fractures with interosseous nylon sutures is reported. The technique was devised for the treatment of a 54-year-old woman with severe asthma and metal allergies that precluded the use of more conventional methods. Allergic reactions to mental implants and alternative stabilization techniques are discussed. The method is suggested not as a routine procedure, but rather as an option to standard means of fracture fixation in similar unusual circumstances.

Carbohydrate (CHO) oxidation in patients with type B insulin resistance.

Total body carbohydrate (CHO) and fat oxidation rates, plasma glucose, free fatty acid, and insulin concentrations were determined in two patients with the type B syndrome of severe insulin resistance and in normal controls in response to insulin infusions (1-100 mU/kg/min) and to a test meal. In addition, insulin was infused at higher rates (10-1000 mU/kg/min) in one of the two patients while plasma glucose concentrations were clamped first at 195 and later at 244 mg/dl. During the postabsorptive state, resting metabolic rates (RMR) were 914 and 979 cal/min/1.73 m2 in the two patients (controls: 1018 +/- 85 cal/min/1.73 m2). Patients met 85% and 83% of their caloric requirements by oxidizing fat (controls: 63 +/- 7%). Protein oxidation accounted for 15% and 13% (controls: 14 +/- 3%) of energy requirements and CHO oxidation for 0% and 0%, respectively, in both patients (controls: 23 +/- 5%). Infusion of insulin at a rate of 10 mU/kg/min raised plasma insulin concentrations from 1400 and 440 microU/ml to 6000 and 2500 microU/ml, respectively, in patients 1 and 2 (controls: from 4 +/- 0.3 to 1288 +/- 50 microU/ml), but had no effects on rates of CHO, fat, or protein oxidation in either patient. By comparison, the rate of CHO oxidation in controls rose about sixfold from 40 +/- 8 to 234 +/- 12 mg/min/1.73 m2. Infusion of 1000 mU/kg/min in combination with an increase in plasma glucose from 195 +/- 1.1 to 244 +/- 1.9 mg/dl in patient 1, however, raised CHO oxidation from 0 to 36 mg/min/1.73 m2 and lowered fat oxidation from 105 to 69 mg/min/1.73 m2.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of anti-insulin receptor antibodies on in vivo insulin metabolism.

The effects of anti-insulin receptor antibodies (AIRA) on receptor binding and insulin metabolism were studied in two patients with the type B, severe insulin resistance syndrome. Insulin binding was determined using rat hepatocytes in primary culture and the patient's own red blood cells. Plasma and urinary insulin concentrations and metabolic clearance rates (MCR) were determined in the two patients and in four normal controls in response to infusions of insulin for 60-120 min at rates ranging from 1 to 925 mU/kg/min. In patient 1, basal insulin concentration was 1400 microU/ml. After infusion of 1, 10, and 925 mU/kg/min of insulin it rose to 3800, 5500, and 225,000 microU/ml, respectively. Respective MCRs were 19, 110, and 186 ml/min. In patient 2, basal insulin concentration was 440 microU/ml. After infusion of 1, 10, and 100 mU/kg/min of insulin it rose to 720, 2500, and 18,800 microU/ml, respectively. Respective MCRs were 193, 262, and 294 ml/min. In controls, basal insulin concentration was 4 +/- 0.3 microU/ml. After infusion of 1 and 10 mU/kg/min of insulin, it rose to 82 +/- 17 and 1288 +/- 50 microU/ml. Respective MCRs were 950 and 630 ml/min. These data showed that, in patients with AIRA: (1) insulin metabolism took place at the same rate but at higher insulin concentrations than in normal controls, and (2) MCR increased with rising insulin concentration but remained subnormal even at the highest insulin concentrations. In contrast, MCR in normal controls decreased with increasing insulin concentrations. The data suggest that prevention of insulin binding prevents insulin metabolism at physiologic insulin concentrations and that supraphysiologically elevated insulin concentrations are needed to activate nonreceptor mechanisms.

The surgical management of lymphedema.

The treatment of lymphedema remains a formidable task for the patient and physician. However, most patients with both primary and secondary lymphedema can be managed satisfactorily by conservative means. Surgical intervention for lymphedema should be considered only after a serious trial of medical management. Although no present surgical technique offers cure, significant improvement is possible by a variety of methods. The staged excision of skin and subcutaneous tissue, the Charles procedure and the dermal flap by Thompson are still the most popular techniques in the United States. Axial and myocutaneous flaps and microsurgical bypass procedures are currently under investigation and may hold promise after additional study. Future experimental and clinical studies should concentrate on long term follow-up study with objective clinical and roentgenographic documentation of improvement.

The surgical management of lymphedema.

The treatment of lymphedema remains a formidable task for the patient and physician. However, most patients with both primary and secondary lymphedema can be managed satisfactorily by conservative means. Surgical intervention for lymphedema should be considered only after a serious trial of medical management. Although no present surgical technique offers cure, significant improvement is possible by a variety of methods. The staged excision of skin and subcutaneous tissue, the Charles procedure and the dermal flap by Thompson are still the most popular techniques in the United States. Axial and myocutaneous flaps and microsurgical bypass procedures are currently under investigation and may hold promise after additional study. Future experimental and clinical studies should concentrate on long term follow-up study with objective clinical and roentgenographic documentation of improvement.

Giant cell tumor of tendon sheath (localized nodular tenosynovitis).

Giant cell tumor of tendon sheath (localized nodular tenosynovitis) remains a disease of unknown origin. Thirty-five giant cell tumors of tendon sheath are reviewed in this study. High recurrence rates can be minimized with attention to accurate preoperative diagnosis and aggressive local excision. The removal of portions of tendon sheath, volar plate, periosteum, or joint capsule may be necessary in selected cases.

Free latissimus dorsi muscle flap with skin graft for treatment of traumatic chronic bony wounds.

Based on this review of 35 cases of chronic bony wounds, it would appear that the free-muscle flap method of wound closure and nourishment after thorough dead bone debridement is an attractive and successful alternative to local skin flaps, staged skin flaps, or extend skin-muscle flaps in areas where reliable muscle flaps are not available. It would also seem that the latissimus dorsi muscle flap with skin graft is an ideal donor-muscle transfer with features allowing a favorable and contoured surface in the recipient site and minimal aesthetic and functional deformity in the donor site.

Orbital exenteration and reconstruction for massive basal cell and squamous cell carcinoma of cutaneous origin.

Eleven patients with basal cell or squamous cell carcinomas of skin origin requiring orbital exenteration over a ten-year period were reviewed. The patient population was characterized by old age, treatment delay, massive tumor size, and inadequate primary therapy. Following orbital exenteration, a 60% recurrence rate and 56% five-year survival were found. Combined craniofacial resection should be considered more frequently in hopes of improving prognosis. Split-thickness skin grafting was the mainstay of reconstruction, especially in elderly patients with smaller lesions. However, most of the operations were performed prior to the popularization of musculocutaneous flaps and free tissue transfers. Temporalis, forehead, and cheek flaps are dependable local alternatives when additional bulk or improved contour is desired. Latissimus dorsi and pectoralis major musculocutaneous flaps and microsurgical tissue transfer allow for coverage of defects of virtually unlimited size and may be superior in cases in which infectious or postradiation complications are anticipated.

Abdominoplasty following gastrointestinal bypass surgery.

An increasing number of postgastrointestinal bypass patients are being referred for secondary plastic surgical procedures. Thirteen patients at this institution have undergone abdominoplasty after surgery for morbid obesity in the past 5 years. The characteristic abdominal deformity includes a draping apron of panniculus frequently associated with previous surgical scars and/or ventral hernia. An abdominoplasty of the low, transverse type with wide undermining is appropriate for most patients. However, vertical or mixed-type abdominoplasties and simple panniculectomies are occasionally indicated owing to residual adiposity and scar location. After bypass surgery, self-image and health-related complaints are markedly improved, but psychological gains can be inhibited by persistent body-contour concerns. Gastrointestinal bypass patients have a high incidence of associated medical problems. Preoperative laboratory evaluations must, therefore, be comprehensive. A variety of early and late complications following gastric and jejunoileal bypass are summarized. In spite of an expected higher complication rate following abdominoplasty, no major complications and three minor complications were discovered in these 13 patients.

Auroral photography from a satellite.

Photographs taken from satellites show the form, location, and intensity of the aurora from a new perspective. They provide an effective way of monitoring auroral activity on a worldwide basis and are likely to become one of the major tools in the effort to understand this phenomenon.