| 2 | A classical equation that accounts for observations of non-Arrhenius and cryogenic grain boundary migration显示文摘Observations of microstructural coarsening at cryogenic temperatures,as well as numerous simulations of grain boundary motion that show faster migration at low temperature than at high temperature,have been troubling because they do not follow the expected Arrhenius behavior.This work demonstrates that classical equations,that are not simplified,account for all these oddities and demonstrate that non-Arrhenius behavior can emerge from thermally activated processes.According to this classical model,this occurs when the intrinsic barrier energies of the processes become small,allowing activation at cryogenic temperatures.Additional thermal energy then allows the low energy process to proceed in reverse,so increasing temperature only serves to frustrate the forward motion.This classical form is shown to reconcile and describe a variety of diverse grain boundary migration observations. | Eric R.Homer Oliver K.Johnson Darcey Britton James E.Patterson Eric T.Sevy Gregory B.Thompson | 2022 | npj Computational Materials2022，，1： | 0 |
| 3 | An NSQIP evaluation of practice patterns and outcomes following surgery for anorectal abscess and fistula in patients with and without Crohn’s disease显示文摘Background:Patients with Crohn’s disease(CD)are believed to have more aggressive anorectal abscess and fistula disease.We assessed the types of procedures performed and perioperative complications associated with the surgical management of anorectal abscess and fistula disease in patients with and without CD.Methods:The American College of Surgeons National Surgical Quality Improvement Program database(ACS-NSQIP,2005-2010)was used to calculate 30-day outcomes using regression modeling,accounting for demographics,comorbidities and surgical procedures.ICD-9 codes for anorectal abscess or fistula were used for initial selection.Patients were then stratified,based on the presence or absence of underlying CD.Local procedures included incision and drainage of abscesses,fistulotomy and seton placement.Cutaneous fistulas were considered simple,while all others were classified as complex(-vaginal,-urethral and-vesical).Results:A total of 7,218 patients(mean age 45 years;64%male)met inclusion criteria,with underlying CD in 345(4.8%).CD patients were more likely to have a seton placed(9.9 vs 8.2%,P<0.001)and be on steroids(15.4 vs 4.3%,P<0.001).Thirty-seven percent of CD patients underwent local procedures,while 46%had a proctectomy and8%underwent diversion.Fistulotomy was more common in those without underlying CD(16 vs 11%,P<0.001).The overall complication rate after local treatment was 4.9%,with no difference between patients with and without CD(7.7 vs 4.9%,P=0.144).This was not affected by fistula type-simple(7.9 vs 3.9%,P=0.194)vs complex(33 vs 7.1%,P=0.21)—or when stratified by wound(3.8 vs 2.4%;P=0.26)or systemic complications(3.8 vs 2.5%;P=0.53).Yet,complications following emergency procedures were higher in patients with CD(21.4 vs 5.9%,P=0.047).Factors significantly associated with increased complications were Crohn’s disease(OR=8.2),lack of functional independence(OR=2.0),pre-operative weight loss(OR=2.6)and pre-operative acute renal failure(OR=5.6).Steroids were also associated with a 1.7-fold increase in complications,independent from CD.Conclusions:While most patients with anorectal abscess/fistula are treated with local procedures,proctectomy and diversion use is fairly common in those with underlying CD.Although complication rates following elective local procedures for anorectal abscess/fistula are similar in patients with and without CD,they are higher in patients on steroids and in CD patients undergoing emergent procedures. | Marlin Wayne Causey Daniel Nelson Eric K.Johnson Justin Maykel Brad Davis David E.Rivadeneira Brad Champagne Scott R.Steele | 2013 | Gastroenterology Report2013，1，1： | 0 |
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