Optimization of the Coupled Cluster Implementation in NWChem on Petascale Parallel Architectures.

The coupled cluster singles and doubles (CCSD) algorithm in the NWChem software package has been optimized to alleviate the communication bottleneck. This optimization provided a 2-fold to 5-fold speedup in the CCSD iteration time depending on the problem size and available memory, and improved the CCSD scaling to 20 000 nodes of the NCSA Blue Waters supercomputer. On 20 000 XE6 nodes of Blue Waters, a complete conventional CCSD(T) calculation of a system encountering 1042 basis functions and 103 occupied correlated orbitals obtained a performance of 0.32 petaflop/s and took 5 h and 24 min to complete. The reported time and performance included all stages of the calculation from initialization to termination for iterative single and double excitations as well as perturbative triples correction. In perturbative triples alone, the computation sustained a rate of 1.18 petaflop/s. The CCSD and (T) phases took approximately (3)/4 and (1)/4 of the total time to solution, respectively, showing that CCSD is the most time-consuming part at the large scale. The MP2, CCSD, and CCSD(T) computations in 6-311++G** basis set performed on guanine-cytosine deoxydinucleotide monophosphate probed the conformational energy difference between the A- and B-conformations of single stranded DNA. Good agreement between MP2 and coupled cluster methods has been obtained, suggesting the utility of MP2 for conformational analysis in these systems. The study revealed a significant discrepancy between the quantum mechanical and classical force field predictions, suggesting a need to improve the dihedral parameters.

Randomized clinical study of Hydrofiber dressing with silver or silver sulfadiazine in the management of partial-thickness burns.

This prospective, randomized study compared protocols of care using either AQUACEL Ag Hydrofiber (ConvaTec, a Bristol-Myers Squibb company, Skillman, NJ) dressing with silver (n = 42) or silver sulfadiazine (n = 42) for up to 21 days in the management of partial-thickness burns covering 5% to 40% body surface area (BSA). AQUACEL Ag dressing was associated with less pain and anxiety during dressing changes, less burning and stinging during wear, fewer dressing changes, less nursing time, and fewer procedural medications. Silver sulfadiazine was associated with greater flexibility and ease of movement. Adverse events, including infection, were comparable between treatment groups. The AQUACEL Ag dressing protocol tended to have lower total treatment costs (Dollars 1040 vs. Dollars 1180) and a greater rate of re-epithelialization (73.8% vs 60.0%), resulting in cost-effectiveness per burn healed of Dollars 1,409.06 for AQUACEL Ag dressing and Dollars 1,967.95 for silver sulfadiazine. A protocol of care with AQUACEL(R) Ag provided clinical and economic benefits compared with silver sulfadiazine in patients with partial-thickness burns.

Long-term intravenous sodium thiosulfate in the treatment of a patient with calciphylaxis.

Calciphylaxis is a disabling and life-threatening complication that primarily affects patients who are dialysis dependent. This disease entity is characterized by calcification, intimal hypertrophy, and thrombosis of small vessels, which results in necrotizing, nonhealing ulcers. The development of these lesions portends a grim prognosis, as they are often accompanied by severe and sometimes fatal infectious complications. Although several strategies aimed at treating and preventing this affliction have been reported in the literature, the outcome for most patients with calciphylaxis remains quite poor. We describe an anuric hemodialysis patient who developed severe calciphylaxis that proved refractory to conventional treatment. Following extensive debridement of several wounds, intravenous sodium thiosulfate was utilized as an adjunctive therapy four times a week. Within 6 months, excellent wound healing ensued as well as a dramatic improvement in the lesions that were not previously resected. Aside from occasional nausea, these treatments were well tolerated, despite the development of an anion gap metabolic acidosis. After 34 months of continued treatment the patient remains free from disease recurrence and has demonstrated no untoward effect of prolonged therapy. In an effort to delineate the pharmacokinetics of this drug in a hemodialysis patient, serum thiosulfate levels were obtained 15 minutes after infusion as well as before and after subsequent dialysis treatments. Consistent with prior studies in anuric canines, we found measurable quantities of the drug more than 50 hours after treatment, in addition to a markedly elevated half life of 478 minutes. However, given the lack of significant toxicity, as well as a dramatic clinical improvement, we feel that sodium thiosulfate may have an important adjunctive role in the treatment of calciphylaxis in dialysis patients.

Social support correlates with survival in patients with massive burn injury.

Large burn size, inhalation injury, age, and associated trauma increase the rate of mortality after burns. However, not all patients with large burns and significant risk factors die. In this study, we wanted to determine other presenting factors that might indicate a survival benefit for burn patients with large burns. We reviewed charts of 36 patients with burns > or =60% TBSA that were aggressively resuscitated at the University of Washington Burn Center from 1990 to 2000 to determine whether survivors of large burns exhibit presenting variables that predict survival. Patients who had comfort care measures initiated at admission were excluded from this analysis. Survivors (n = 16) and nonsurvivors (n = 20) had no significant differences in age, total burn size, inhalation injury, or need for escharotomy. Full-thickness burn size was significantly smaller for survivors (58%) than for nonsurvivors (73%; P = .02). Survivors (81%) were more likely than nonsurvivors to have social support (35%; P = .007). A full-thickness burn > or =80 % TBSA was the only variable uniformly associated with mortality, suggesting that patients who survive large burns have a partial-thickness component that heals without surgery. The difference in degree of social support was one unique distinction that may impact patient survival and is worth further investigation.

A regional burn center's response to a disaster: September 11, 2001, and the days beyond.

This report reviews the response of a regional burn center to the disaster that occurred in New York City at the World Trade Center on September 11, 2001. In addition, it assesses that response in the context of other medical institutions in the region. There were facilities in the region that had 120 burn care beds; only two-thirds of the burn-injured patients who required hospital admission were admitted to designated burn centers, and only 28% of burn-injured victims initially were triaged to regional burn centers. The care rendered at this center was made possible by a "disaster-ready" facility and supplementation of personnel from the resources provided by The National Disaster Medical System. The patient outcomes at this center exceeded that as predicted by logistic regression analysis.

Firefighter burn injuries: a 10-year longitudinal study.

Our metropolitan area employs approximately 11,000 firefighters who respond to more than 435,000 fire-related incidents per year. It is inevitable that some of these firefighters will suffer burn injuries. This 10-year retrospective review describes the epidemiology of firefighters with burn injuries who were treated at our burn center. From 1992 to 2002, 987 firefighters were treated at our burn center. The total number of firefighters treated for burn injuries and the number of firefighters who were treated for burn injuries to the lower extremities occurred in a bimodal distribution. Injury prevention efforts will continue to further reduce the incidence of burn injuries in the firefighters of our community.

Fixation for the millennium: the shoulder.

Charles Neer designed his original prosthesis in 1951. It was made of cast cobalt chrome alloy and was only press-fit. There was not any significant loosening in his original series, but patients complained of easy fatigability. This finding was attributed to glenoid issues and a cemented glenoid replacement was introduced in 1973. High rates of lucencies were reported and raised issues regarding fixation. Cementless glenoid components have been found to have fewer lucencies but require metal backing. Higher failure rates have been reported for the cementless design versus the cemented glenoids. With humeral fixation, symptomatic loosening is not a problem with cement or coated press-fit fixation. Long-term outcome studies with cemented and uncemented stems have shown the incidence of humeral loosening to be low. Fixation of humeral components should be based on bone quality, patient age, prosthetic design, and surgeon preference.

Postoperative pain control following arthroscopic release of adhesive capsulitis: a short-term retrospective review study of the use of an intra-articular pain catheter.

PURPOSE: The purpose of this study was to examine the effectiveness of an arthroscopically placed intra-articular pain catheter for controlling postoperative pain and also review the results following arthroscopic release of refractor adhesive capsulitis. TYPE OF STUDY: Retrospective clinical trial. METHODS: Twenty-three consecutive cases (20 patients) of arthroscopic adhesive capsulitis release in which an intra-articular pain catheter was used were reviewed. Follow-up ranged from 12 to 37 months (average, 22.4 months). An intra-articular catheter was placed under direct arthroscopic visualization from a superior approach into the glenohumeral joint. Postoperatively, patients were injected with 10 mL of 0.5% bupivacaine every 6 hours as needed. Preoperatively, all patients had filled out a questionnaire based on the American Shoulder and Elbow Surgeons (ASES) outcome guidelines and examined for range of motion. Postoperatively, patients were asked for their precatheter and postcatheter injection pain level based on the visual analog scale (1 to 10 points, 1 = no pain). Patients were then examined for range of motion and retested with the outcome questionnaire. An ASES Shoulder Score Index was calculated for each patient before and after the procedure. RESULTS: The average forward elevation preoperatively was 102 degrees and external rotation at the side was 4.5 degrees. At most recent follow-up, average forward elevation was 169 degrees with external rotation at the side 47 degrees. The Shoulder Score Index increased from an average of 37.1 out of 100 to 90.9 (P <.001). Before being injected with anesthetic through the catheter, patients had an average visual analog scale score of 8.1. Postinjection average pain level was 1.2 (P <.001) and all patients indicated that the pain catheter significantly reduced postoperative pain. Nineteen of 20 patients were satisfied with the procedure. CONCLUSIONS: Placement of an intra-articular pain catheter for delivery of bupivacaine was highly effective in controlling postoperative pain. In all cases, postoperative pain was essentially eliminated and this substantially assisted with range of motion exercises. Near complete restoration of range of motion without pain was achieved in 95% of the patients.

The actin cytoskeleton: an essential component for enhanced TNFalpha production by adherent monocytes.

Monocyte adherence induces the formation of focal adhesions, the interaction sites of intracellular signaling molecules and cytoskeletal proteins such as actin. We previously demonstrated that adherence potentiates human monocyte LPS-induced TNFalpha production. Hence, we hypothesized that the actin cytoskeleton is integral to adherence-induced priming for enhanced LPS-induced TNFalpha production. In contrast to nonadherent cells, LPS induced significant transcription of TNFalpha mRNA and production of TNFalpha in adherent monocytes. Disrupting the actin cytoskeleton with cytochalasin D (CD) in adherent monocytes inhibited LPS-induced TNFalpha production by 55%, thereby abrogating adherence-induced priming. Moreover, CD pretreatment abrogated adherence-induced activation of Pyk2, a major focal adhesion kinase, and ERK 1/2, a component of the mitogen-activated protein kinase (MAPK) signaling pathway, and it completely inhibited LPS-induced ERK 1/2 activation. However, CD treatment of nonadherent monocytes failed to inhibit cytokine production. In conclusion, the actin cytoskeleton is integral in the reprogramming of the monocyte for enhanced cytokine production and in maintaining this "primed" state.

Arthroscopic release of the rotator interval and coracohumeral ligament: An anatomic study in cadavers.

PURPOSE: The purpose of this cadaveric study was to examine the anatomy of the normal glenohumeral joint relevant to an arthroscopic rotator interval release and define both the endpoints of a complete release of the coracohumeral ligament and the relationship to surrounding tendons and nerves. TYPE OF STUDY: An anatomic cadaveric study. METHODS: Fifteen fresh-frozen cadaveric specimens were studied with 5 specimens in group I and 10 specimens in group II. Group I specimens were used to examine the relevant anatomy, including the structures at risk, the dimensions of the rotator interval, and potential endpoints for release of the coracohumeral ligament. Measurements included (1) the supraspinatus to the subscapularis distance, (2) the distance from the rotator interval to the deep surface of the coracoid process, and (3) the distance from the rotator interval to the coracoacromial ligament at the level of the glenoid. Group II specimens underwent arthroscopic release of the rotator interval using the appearance of the coracoacromial ligament as the superficial endpoint. Dissection was then performed to examine for complete release of the coracohumeral ligament and to assess the structures at risk of injury. RESULTS: The distance from the anterior edge of supraspinatus to the superior edge of subscapularis at the glenoid rim was 21.6 mm, which increased to 27.8 mm with joint distention. The minimum distance from the rotator interval to the deep surface of the coracoid process was 11.4 mm. Before distention, the coracoacromial ligament was an average of 6.2 mm from the rotator interval capsule. Arthroscopic release from the supraspinatus to the subscapularis resulted in complete resection of the coracohumeral ligament in all 15 specimens. There were no specimens with evidence of injury to the biceps tendon, supraspinatus, subscapularis, or the conjoint tendon. CONCLUSIONS: This study confirms that intra-articularly directed arthroscopic release of the rotator interval can safely lead to complete release of the coracohumeral ligament if dissection is taken superficially to the level of the coracoacromial ligament.