Self-doping of ultrathin insulating films by transition metal atoms.

Single magnetic Co atoms are deposited on atomically thin NaCl films on Au(111). Two different adsorption sites are revealed by high-resolution scanning tunneling microscopy (STM), i.e., at Na and at Cl locations. Using density functional based simulations of the STM images, we show that the Co atoms substitute with either a Na or Cl atom of the NaCl surface, resulting in cationic and anionic Co dopants with a high thermal stability. The dependence of the magnetic coupling between neighboring Co atoms on their separation is investigated via spatially resolved measurement of the local density of states.

An indigestion or a viral gastritis, or not?

Case report: An 18 mth old boy was sent to the Emergency Room of the Jessa Hospital (Hasselt, Belgium) because of persistent vomiting. The clinical examination was without particularities, except for a runny nose. The diagnosis of indigestion or (viral) gastritis was made. Patient was sent home. He was represented at the ER five days later. He stopped vomiting for 3 consecutive days after his first hospital visit, but started to vomit again the last 2 days, the last night even two times with bilious vomiting. His appetite was decreased since one week. The infant was not comfortable during abdominal palpation. This finding led to the decision for further investigations. An abdominal ultrasound showed air superposition in the epi- and mesogastrium. There were no signs of intussusception. An abdominal X-ray was performed (fig 1). Answer and discussion: The abdominal X-ray showed a corpus alienum, presumably magnets, in the mesogastrium and free air under the right diaphragm (fig. 1). An abdominal CT-scan could not visualise whether the magnets were situated in- or outside the intestinal lumen. At laparoscopy, clitted small intestinal loops with multiple perforation sites were detected as well as a purulent peritonitis in the left fossa iliaca (fig. 2). Magnets were removed. Perforations were sutured. Postoperatively augmentin was given. Patient recovered completly. can attract each other through the intestinal wall, get stuck and pinch the digestive tract causing major and sometimes life-threatening intestinal perforation (1). Endoscopical or surgical removal can be performed, based on location and complications (2,3).

Structural identification of caged vanadium doped silicon clusters.

The geometry of cationic silicon clusters doped with vanadium, Si(n)V(+) (n=12-16), is investigated by using infrared multiple photon dissociation of the corresponding rare gas complexes in combination with ab initio calculations. It is shown that the clusters are endohedral cages, and evidence is provided that Si(16)V(+) is a fluxional system with a symmetric Frank-Kasper geometry.

Long-term stability of isolated advancement genioplasty, and influence of associated risk factors: A systematic review.

The aim of this review was to investigate the skeletal and soft tissue stability of isolated advancement genioplasty after more than 1 year, and to observe the influence of associated risk factors. A literature search was performed on PubMed, Web of Science, Embase, ScienceDirect, and Cochrane. Only studies with at least 10 patients who underwent an isolated advancement genioplasty, and with a follow-up period of at least 1 year, were included. Of the 2224 records initially identified, eight articles met the eligibility criteria. The mean age of the total study population was 23 years and ranged from 19.1 to 26.5 years in the individual studies. The average surgical advancement at pogonion was 8.2 mm and ranged from 6.2 to 11.7 mm in the individual studies. After 1 year, the horizontal hard tissue relapse at the level of pogonion varied from 0.1 to 2.1 mm. In two studies, this was reported as statistically significant. Regarding the soft tissue, the horizontal relapse varied from 0.3 to 2.9 mm, which was also considered statistically significant in two studies. Isolated advancement genioplasty was found to be a predictable and stable orthognathic procedure in the sagittal plane at both soft and hard tissue levels. The amount of relapse was not associated with the fixation method or with the amount of surgical advancement.

Probing Magnetism in 2D Molecular Networks after in Situ Metalation by Transition Metal Atoms.

Metalated molecules are the ideal building blocks for the bottom-up fabrication of, e.g., two-dimensional arrays of magnetic particles for spintronics applications. Compared to chemical synthesis, metalation after network formation by an atom beam can yield a higher degree of control and flexibility and allows for mixing of different types of magnetic atoms. We report on successful metalation of tetrapyridyl-porphyrins (TPyP) by Co and Cr atoms, as demonstrated by scanning tunneling microscopy experiments. For the metalation, large periodic networks formed by the TPyP molecules on a Ag(111) substrate are exposed in situ to an atom beam. Voltage-induced dehydrogenation experiments support the conclusion that the porphyrin macrocycle of the TPyP molecule incorporates one transition metal atom. The newly synthesized Co-TPyP and Cr-TPyP complexes exhibit striking differences in their electronic behavior, leading to a magnetic character for Cr-TPyP only as evidenced by Kondo resonance measurements.

Small subcortical infarcts and primary subcortical haemorrhages may have different risk factors.

Primary subcortical haemorrhages (SCH) and small subcortical infarcts (SSI) arise from changes in penetrating perforating arteries. The aim of this study was to compare cerebrovascular risk factors between patients with SCH and patients with SSI. Of 396 patients with a first-ever stroke (226 males; 170 females; median-age: 63), 108 had SSI, and 64 SCH, with or without subcortical infarcts co-existing. Patients with SCH were less likely to have current atrial fibrillation or associated non-lacunar infarcts, but they were more likely to have arterial hypertension (except after exclusion of patients with co-existence of SSI and SCH) and alcoholism, and they were significantly younger and had lower leukoaraiosis scores. The independent factors for SCH were alcoholism, arterial hypertension and lack of significant internal carotid artery stenosis. The only independent factor for SSI was leukoaraiosis score. Hypertension was the most important risk factor in both groups, but its prevalence was higher in the SCH group. Whether patients will develop SSI or SCH probably depends on associated risk factors such as alcohol consumption. Further studies should also take into account the characteristics of arterial hypertension.

Pravastatin in diabetes-associated hypercholesterolemia.

Patients with diabetes mellitus (DM), type 1 and type 2, have an increased risk of coronary heart disease as a result of accelerated atherosclerosis. Dyslipidemia, often found in these patients, plays an important role in this process. This study investigates the efficacy and safety of lipid-lowering therapy with pravastatin, a 3-HMG-Coenzym A reductase inhibitor in hypercholesterolemic type-1 and type-2 diabetic patients. Of 49 patients (22 type-1 DM and 27 type-2 DM), 24 patients were treated with pravastatin, 20 mg/day, and 25 patients with placebo. After 24 weeks, total cholesterol (TC) was decreased by 22.2%, low-density lipoprotein (LDL) cholesterol by 25.8% and triglycerides (TG) by 13.6%. Pravastatin treatment did not induce a significant change in high-density (HDL) cholesterol levels. No differences in effects of pravastatin treatment on serum lipids and lipoproteins were found with respect to the diabetes type. No serious side effects occurred and pravastatin treatment did not cause any deterioration in glycemia control. The data suggest that pravastatin is effective and safe in the treatment of dyslipidemia in both type-1 and type-2 diabetic patients.

Ventricular fibrillation in hypercalcaemic crisis due to primary hyperparathyroidism.

We report the case of a 64-year-old man who presented with severe hypercalcaemia secondary to primary hyperparathyroidism. Soon after admission he developed ventricular fibrillation with no other cause than this severe hypercalcaemia. Although the occurrence of cardiac arrhythmias in hypercalcaemia is widely known, ventricular fibrillation has never been described before.

Effect of BMI, insulin dose and number of injections on glycaemic control in insulin-using diabetic patients. Studygroup Diabetes Rijnmond (SDR).

BACKGROUND: Strict glucose control is essential to the prevention of diabetic complications. The level of glycaemic control in insulin-treated patients with diabetes mellitus (DM) in a routine clinical setting is not known. METHODS: In a cross-sectional survey comprising 8 hospitals in the Rijnmond area, The Netherlands, age, body mass index (BMI), insulin dose, number of injections, and HbA1c were scored in 712 patients with insulin-dependent DM (IDDM) and 462 patients with non-insulin-dependent DM (NIDDM). RESULTS: In IDDM and NIDDM patients, respectively, age (mean +/- SD) was 40 +/- 17 and 65 +/- 12 years, BMI was 24.1 +/- 3.5 and 27.3 +/- 4.1 kg/m2, daily insulin dose was 49 +/- 18 and 44 +/- 18 U (P < 0.001). Intensive therapy (> or = 4 injections or continuous subcutaneous insulin infusion) was used in 59% of IDDM and 13% of NIDDM patients. HbA1c below the upper normal limit was achieved in 11% of the patients, and within 20% above the upper normal limit in 37%. Obesity was positively associated with HbA1c in NIDDM patients (P < 0.01). A higher insulin dose was associated with higher HbA1c in both IDDM and NIDDM patients (P < 0.01). CONCLUSIONS: Good glycaemic control was established in 37% of our patients. Intensive insulin treatment and higher insulin dose did not improve glucose regulation. Obesity is a risk factor for poor glycaemic control.

The effect of heavy metal exposure on egg size, eggshell thickness and the number of spermatozoa in blue tit Parus caeruleus eggs.

In this study we compared the egg size, the eggshell thickness and the number of spermatozoa trapped on the perivitelline layer of the eggs in three blue tit (Parus caeruleus) populations across a heavy metal pollution gradient. No significant differences were observed in egg characteristics among study sites. Eggs from the two most polluted sites however, had significantly less spermatozoa on the perivitelline layer than eggs from the least polluted site. Our results suggest a significant effect of pollution on blue tit sperm concentrations in the infundibulum. Determining the number of spermatozoa on the egg membranes is relatively cheap and straightforward, which renders this technique a new and useful tool in biomonitoring.

Heavy metals and selenium in feathers of great tits (Parus major) along a pollution gradient.

We evaluated the use of great tit (Parus major) feathers as biomonitors for heavy-metal pollution and tested whether there were differences in metal levels in feathers as a function of location, age (first year or older), or gender. In 1998 and 1999, we collected the outermost tail feathers of 185 great tits from four sites along a presumed pollution gradient and one reference site in Antwerp (Belgium) and analyzed them for calcium, selenium, and 13 heavy metals (silver, aluminum, arsenic, cadmium, cobalt, chromium, copper, iron, mercury, manganese, nickel, lead, and zinc). Silver, arsenic, cadmium, cobalt, copper, mercury, nickel, lead, selenium, and zinc concentrations were significantly higher closest to the pollution source (UM site) compared with the other four sites. Heavy-metal and selenium levels were on average 2 to 40 times higher at the UM site compared with the reference site. Aluminum, calcium, and iron levels were not significantly different among sites. We found no general age- or gender-related differences in metal levels except for arsenic and iron, where a significant interaction between site and gender was observed. Our results suggest that feathers of great tits might be useful biomonitoring tools because they reflect the environmental contamination by heavy metals well.

[Cerebral venous thromboses: study of the course]. / Thromboses veineuses cérébrales: étude de l'évolution.

The management of patients with presumed cerebral venous thrombosis has been recently modified by magnetic resonance imaging and evidence that heparin decreases mortality and morbidity. No large consecutive series of patients with cerebral venous thrombosis has been reported since then. The aim of our study was to determine the prognosis factors of patients with cerebral venous thrombosis. Demographic, clinical and radiological characteristics were recorded in a homogeneous series of 18 consecutive patients with cerebral venous thrombosis collected over a 31-month period. All patients were treated by heparin at the acute stage. We found no difference in demographic, clinical and radiological characteristics of the patients according to the 1-month and 6-month outcome. We only found a tendency towards a better 1-month outcome in younger patients (p = 0.06) and in patients with an isolated intracranial hypertension (2p = 0.06). A long therapeutic delay might be a factor of poor prognosis which might be hidden by a better spontaneous outcome in patients with isolated intracranial hypertension in whom the diagnostic delay is longer. A multicentric study allowing a multivariate analysis may therefore be useful to identify prognosis factors in patients with cerebral venous thrombosis.

[Supra-aortic arteries angioplasty and stenting: an ultrasonographic follow up]. / Surveillance ultrasonographique de l'angioplastie des troncs supra-aortiques.

PURPOSE: Ultrasonographic follow up of patients with supra-aortic arteries angioplasty and stenting was performed to determine the normal characteristics and to detect restenosis or thrombosis at the repair site. MATERIAL AND METHODS: Twenty-eight patients were followed. The delay between the procedure and the ultrasonographic examination was 1 to 5 years. There were 32 procedures: 7 carotid angioplasties with stenting; 32 vertebral angioplasties (2 stentings), 2 brachiocephalic artery angioplasties (1 stenting); 1 subclavian artery angioplasty. The ultrasonographic examination included morphological and bilateral flow analysis. The usual criteria were measured. Special attention has been given to the morphological aspect of the stents. RESULTS: All of the carotid stents were patent. No restenosis appeared during the follow up. A parietal thickening was observed in one patient without significant reduction of the arterial lumen. There were one vertebral and one brachiocephalic stent thrombosis. The results of the ultrasonographic examinations correlated well with magnetic resonance imaging. CONCLUSION: The ultrasonographic follow up of supra aortic arteries angioplasty and stenting is feasible. An early examination is recommended after the vascular procedure to control the efficacy of the repair and to detect and quantify the residual lesions. This phase is compulsory for an optimal long term follow up.

MR enterography in children with Crohn disease: results from the Belgian pediatric Crohn registry (Belcro).

INTRODUCTION: Magnetic Resonance enterography (MRE) is an imaging modality avoiding ionizing radiation and the discomfort associated with enteroclysis. The results of MRE at diagnosis in the patients of the Belgian pediatric Crohn registry (Belcro) are compared to endoscopical and histological results. METHODS: Results of MRE, endoscopy and histology were obtained from the medical charts and assigned to one of the following segments: jejunum, ileum, ascending colon, transverse colon, descending colon or rectosigmoid. MRE images were reviewed in a blinded way by 4 radiologists with specific interest in pediatric MRE. RESULTS: From the Belcro registry, twenty-two patients underwent a MRE during their work-up for Crohn disease. The results of endoscopy, histology and MRE were concordant (either all negative or positive) in the ileum in 16/18 patients and in the rectosigmoid, descending colon, transverse colon and ascending colon in resp 9, 8, 8 and 8/22 patients. In the non-concordant cases (MRE colon negative but endoscopy and/or histology positive), MRE could not reflect the subtle endoscopic or histologic lesions such as erosions that were described.In 4 cases where ileocaecal valve intubation was impossible ileal MRE findings were abnormal. MRE detected ileal stenosis, jejunal lesions and fistula in resp 4/22, 3/22 en 2/22 patients. The 100% and 75% interobserver agreement was resp 50-82% and 773-100% according to the different intestinal segments. CONCLUSIONS: MRE is a promising imaging modality avoiding radiation in Crohn disease. It should probably become the technique of first choice for the evaluation of extensive small bowel disease in children with Crohn disease.

Takotsubo cardiomyopathy or apical ballooning: a case report and a short literature study.

Takotsubo cardiomyopathy is an important differential diagnosis in patients with an acute coronary syndrome. This syndrome is typically characterized by a reversible contractile dysfunction of the left ventricular myocardium without any obstructive etiological coronary disease. This is not a rare entity in acute settings and a better knowledge of the syndrome could result in a heightened alertness and a higher detection. We present a case of takotsubo showing the importance of cardiac MRI in the differential diagnosis and reviewed the present literature concerning this syndrome and the usefulness of MRI in the detection.

Combining tiotropium and salmeterol in COPD: Effects on airflow obstruction and symptoms.

BACKGROUND: Clinical information on 24-h spirometric efficacy of combining tiotropium and salmeterol compared to single-agent therapy is lacking in patients with COPD. METHODS: A randomized, double-blind, four-way crossover study of 6-week treatment periods comparing combination therapy of tiotropium 18 microg plus qd or bid salmeterol 50 microg versus single-agent therapy. Serial 24-h spirometry (FEV(1), FVC), effects on dyspnea (TDI focal score) and rescue salbutamol use were evaluated in 95 patients. RESULTS: Tiotropium plus qd salmeterol was superior to tiotropium or salmeterol alone in average FEV(1) (0-24h) by 72 mL and 97 mL (p<0.0001), respectively. Compared to this qd regimen, combination therapy including bid salmeterol provided comparable daytime (0-12h: 12 mL, p=0.38) bronchodilator effects, but significantly more bronchodilation during the night-time (12-24h: 73 mL, p<0.0001). Clinically relevant improvements in TDI focal score were achieved with bronchodilator combinations including salmeterol qd or bid (2.56 and 2.71; p<0.005 versus components). Symptom benefit of combination therapies was also reflected in less need for reliever medication. All treatments were well tolerated. CONCLUSION: Compared to single-agent therapy, combination therapy of tiotropium plus salmeterol in COPD provided clinically meaningful improvements in airflow obstruction and dyspnea as well as a reduction in reliever medication.