Hydrogen on screw dislocation in Fe and W: existence of 3D-compound and exotic segregation profile

We present the study of hydrogen atom segregation on screw dislocation in Fe and W metals by means of rigid lattice Monte Carlo simulations using interaction energies obtained from ab initio calculations. These interaction energies are attractive or repulsive depending on direction and distance. This high interaction anisotropy leads to the formation of a 3D compound for both iron and tungsten. A second consequence is that, within a given temperature range, hydrogen enrichment is greater at the outer than at the innermost sites of the dislocation. This unusual behavior is only observed for iron. We propose a mean-field model that accounts for the ordering phenomenon to explain the results and the differences between the two metals

[Pulmonary and renal tuberculosis with cerebral tuberculoma mimicking metastatic lung cancer]

International audienc

Challenging a classic myth: pneumoperitoneum associated with acute diverticulitis is not an indication for open or laparoscopic emergency surgery in hemodynamically stable patients. A 10-year experience with a nonoperative treatment.

Background In patients presenting with acute diverticulitis (AD) and signs of acute peritonitis, the presence of extradigestive air (EDA) on a computer tomography (CT) scan is often considered to indicate the need for emergency surgery. Although the traditional management of “perforated” AD is open sigmoidectomy, more recently, laparoscopic drainage/lavage (usually followed by delayed elective sigmoidectomy) has been reported. The aim of this retrospective study is to evaluate the results of nonoperative management of emergency patients presenting with AD and EDA. Methods The outcomes of 39 consecutive hemodynamically stable patients (23 men, mean age = 54.7 years) who were admitted with AD and EDA and were managed nonoperatively (antibiotic and supportive treatment) at a tertiary-care university hospital between January 2001 and June 2010 were retrospectively collected and analyzed. These included morbidity (Clavien-Dindo) and treatment failure (need for emergency surgery or death). A univariate analysis of clinical, radiological, and laboratory criteria with respect to treatment failure was performed. Results of delayed elective laparoscopic sigmoidectomy were also analyzed. Results There was no mortality. Thirty-six of the 39 patients (92.3%) did not need surgery (7 patients required CT-guided abscess drainage). Mean hospital stay was 8.1 days. Duration of symptoms, previous antibiotic administration, severe sepsis, PCR level, WBC concentration, and the presence of abdominal collection were associated with treatment failure, whereas “distant” location of EDA and free abdominal fluid were not. Five patients had recurrence of AD and were treated medically. Seventeen patients (47.2%) underwent elective laparoscopic sigmoidectomy for which mean operative time was 246 min (range = 100–450) and the conversion rate was 11.8%. Mortality was nil and the morbidity rate was 41.2%. Mean postoperative stay was 7.1 days (range = 4–23). Conclusions Nonoperative management is a viable option in most emergency patients presenting with AD and EDA, even in the presence of symptoms of peritonitis or altered laboratory tests. Delayed laparoscopic sigmoidectomy may be useless in certain cases and its results poorer than expected

Appendiceal stump mucocele

International audienc

Hemoperitoneum caused by a ruptured GIST located in the posterior gastric wall managed by endoscopic diagnosis and laparoscopic treatment: case report and literature review.

A case of hemoperitoneum caused by a ruptured gastrointestinal stromal tumor (GIST) of the posterior gastric wall is presented. An otherwise healthy 81-year-old man presented with abdominal pain/tenderness and anemia (hemoglobin: 7.4 g/dL). Computed tomography scan showed hemoperitoneum and a gastric mass of uncertain nature. As the patient was hemodynamically stable, a mini-invasive approach was decided. Esophagogastroscopy revealed an umbilicated mass of the posterior gastric wall, therefore allowing for a correct preoperative diagnosis of GIST and its appropriate treatment by laparoscopic atypical gastrectomy. Laparoscopically, a longitudinal resection of gastric fundus including the tumor was performed in a sleeve gastrectomy fashion, 25 minutes after the induction of pneumoperitoneum. The outcome was uneventful. Pathologic examination confirmed a benign 4×3-cm gastric GIST with <1 mitosis per 50 high power field, staining positive for CD117 (C-KIT) and negative for S-100 protein and smooth muscle actin. To our knowledge, it is the first case of a successful laparoscopic resection of an endoscopically diagnosed gastric GIST in an emergency setting. Hemoperitoneum is a rare, potentially severe complication of GIST. As bleeding is rarely severe, most patients may benefit from a mini-invasive approach, even if the tumor is located in the posterior gastric wall