Eley-rideal reactions with N atoms at Ru(0001): formation of NO and N(2).

Forward-directed NO molecules with large translational energies are formed upon exposure of an O-covered Ru(0001) surface to a nitrogen (N+N_{2}) beam. This is an unequivocal experimental demonstration of the Eley-Rideal reaction for a "heavy" (i.e., nonhydrogenated) neutral system. The time dependence of prompt NO formation exhibits an exceptionally fast decay as a consequence of shifting reaction pathways and probabilities over the course of the exposure. Prompt production shuts down as the O coverage decreases due to competition from more favorable Eley-Rideal production of N_{2}.

Outstanding Fill Factor in Inverted Organic Solar Cells with SnO2 by Atomic Layer Deposition.

Transport layers are of outmost importance for thin-film solar cells, determining not only their efficiency but also their stability. To bring one of these thin-film technologies toward mass production, many factors besides efficiency and stability become important, including the ease of deposition in a scalable manner and the cost of the different material's layers. Herein, highly efficient organic solar cells (OSCs), in the inverted structure (n-i-p), are demonstrated by using as electron transport layer (ETL) tin oxide (SnO2 ) deposited by atomic layer deposition (ALD). ALD is an industrial grade technique which can be applied at the wafer level and also in a roll-to-roll configuration. A champion power conversion efficiency (PCE) of 17.26% and a record fill factor (FF) of 79% are shown by PM6:L8-BO OSCs when using ALD-SnO2 as ETL. These devices outperform solar cells with SnO2 nanoparticles casted from solution (PCE 16.03%, FF 74%) and also those utilizing the more common sol-gel ZnO (PCE 16.84%, FF 77%). The outstanding results are attributed to a reduced charge carrier recombination at the interface between the ALD-SnO2 film and the active layer. Furthermore, a higher stability under illumination is demonstrated for the devices with ALD-SnO2 in comparison with those utilizing ZnO.

Performance of the Standard 22G Needle for Endoscopic Ultrasound-guided Tissue Core Biopsy in Pancreatic Cancer.

BACKGROUND AND AIM: Endoscopic ultrasonography (EUS) and EUS-guided fine-needle aspiration (EUS-FNA) are considered good tools for the diagnosis of pancreatic cancer and for obtaining material for cytology or histology. The accuracy of EUS-FNA can rise to 85-95%, but it is lower in cases with a chronic pancreatitis background or with previous biliary stenting. We aimed to establish the diagnostic yield of the visible length of the core biopsy samples in pancreatic cancer by using one single type of standard 22G needle and to evaluate the factors which can influence the results. METHOD: EUS-FNA was performed by using a 22G standard needle on patients prospectively recruited with the suspicion of pancreatic masses on transabdominal ultrasound or CT scan over a period of eight months. The number of passes was limited by the length of the core obtained. The final diagnosis was based on EUS-FNA or hepatic biopsy for their metastasis or by follow up every three month by imaging methods. RESULTS: The study included 118 patients. Previous stents were present in 10 patients and chronic pancreatitis features were found in 3 patients. The procedure sensitivity was 89% and the global accuracy was 89%. The presence of biliary stents did not impede the accuracy of results. The number of passes did not influence the results. CONCLUSIONS: The diagnostic rate of core biopsy by using 22G needles had a high accuracy and it is safe when the length of core dictates the number of passes. The presence of biliary stents did not influence the results.

Gastrointestinal lymphomatous polyposis--clinical, endoscopical and evolution features. A case report.

Primary gastrointestinal non-Hodgkin lymphoma accounts for 13-18% of all malignant tumours of small bowel and only 1 % of large bowel tumours (1). Multiple lymphomatous polyposis is a rare entity, characterized by the presence of multiple lymphomatous polyps along the gut (2). Majority of cases with gastrointestinal primary lymphoma are classified histologically as "mantle cell" lymphomas. A 59 year old patient was admitted to our clinic for fatigue and rectal bleeding. Endoscopic examination of the colon revealed an infiltrative-exulcerative lesion of the terminal ileon, a polypoid mass on ileocecal valve and multiple polyps over the entire colon and rectum. Gastroscopy revealed polyps into the duodenal bulb. Histopathological and immunohistochemical studies on biopsy specimens from colon and duodenum confirmed gastrointestinal non-Hodgkin lymphoma, probably "mantle cell" lymphoma. Because she was in an advanced stage she received only cytostatic treatment. A clinical, endoscopical and histopathological follow up at 3, 6 and 12 months was performed.

Prospective comparison between real time contrast enhanced and conventional ultrasound guidance in percutaneous biopsies of liver tumors.

AIMS: The performance of percutaneous echo-guided biopsy in the hepatic tumoral diagnosis is limited (90% sensitivity) by several factors, among which tumor characteristics (type, size, and location) play an important role. Contrast enhanced ultrasound guided percutaneous biopsy (CEUS-PLB) is a new developed technique aimed at increasing the accuracy of percutaneous biopsies. The objective of our study was to evaluate the feasibility and performance of CEUS as a guiding method in performing liver biopsy (PLB). MATERIAL AND METHODS: One hundred and seventy one patients with liver tumors referred to the ultrasound department for LB were prospectively included in the study. PLB was performed with CEUS guidance in 90 patients (46 in patients with and 44 in patients without liver cirrhosis), in the remaining 81 (37 in patients with liver cirrhosis and 44 in patients without) with conventional US guidance. The lesions in the CEUS -PLB group were larger than those in the US-LB group (mean diameter 7.73 cm vs. 6.11 cm, p>0.05). In both groups the lesions were further divided in: a) lesions on cirrhosis; b) poorly visualized tumors; c) large tumors (>6 cm); d) cystic tumors; e) recurrences after ablation; and f) portal vein thrombosis. RESULTS: Real time CEUS-PLB was technically successful in 84 of the 86 procedures (97.6% technical success rate). The rate of successful single puncture attempt in CEUS-PLB (43.02%) was higher than in the US-PLB group (23.4%) (p<0.05). The sensitivity of LB was significantly higher in the CEUS-PLB group than in the conventional US-LB group for all lesions (96.5% vs. 81.48%, p<0.05), for lesions on liver cirrhosis (95.2% vs. 75%, p<0.05), for large (> 6 cm) (97.8% vs. 82%, p<0.05), and for poorly visible lesions (100 vs. 66.6%, p=0.029). The patients with inconclusive pathological results after conventional guided LB were then biopsied with CEUS guidance. In all cases the final diagnosis could be established. One major complication occurred in each group (p>0.05). CONCLUSIONS: Percutaneous LB performed with CEUS guidance is a feasible and safe technique. It significantly improves the overall sensitivity of the procedure especially in patients with large lesions and in those poorly visualized on conventional ultrasound.

Education and management of patients with familial adenomatous polyposis. Are we making progress? A case report.

A 25-year-old male patient was admitted to our clinic for abdominal pain, diarrhea, intermittent rectal bleeding and weight loss. The family history revealed two deaths due to colorectal cancer (maternal grandmother and patient's mother). The colonoscopy showed hundreds of polyps throughout the colon, and an ulcerative rectosigmoidian tumor. The diagnosis was Familial Adenomatous Polyposis (FAP). Colectomy with ileorectal anastomosis was performed. Histopathological diagnosis revealed moderately differentiated adenocarcinoma. Adjuvant chemotherapy was carried out. The patient had three brothers, without clinical symptoms. They had a colonoscopic examination for screening. Two of them were diagnosed with adenomatous polyposis - the first with classic FAP and the other one with the attenuated type (AFAP). The diagnosis of FAP can be made on the basis of either clinical or genetic criteria. When the family history, clinical features, and pathological findings are classic, the diagnosis is straightforward. Screening and prophylactic surgery are effective to prevent colorectal cancer in patients with FAP. Lifelong regular surveillance is necessary to detect and manage extracolonic lesions.

Endoscopic mucosal resection for early esophageal cancer. A case report.

With the rapid progress of the diagnostic techniques, especially endoscopy, the discovery rate of early superficial cancer of the esophagus has increased markedly. Relatively recently introduced, endoscopic mucosal resection (EMR) is now widely used in the treatment of early stage cancer of the esophagus. We used EMR in the case of a patient who was incidentally diagnosed with a type IIa early esophageal cancer using a band-ligating device. We had no serious complications. At the histopathological examination we noticed that the carcinoma involved the upper third of the submucosal layer. For this reason the patient was given additional therapy (radiotherapy), too. A month after the EMR, at the histological examination we found no local signs of recurrent disease.

Usefulness of contrast enhanced ultrasound guidance in percutaneous biopsies of liver tumors.

The performance of percutaneous echoguided biopsy in hepatic tumor diagnosis is limited by several factors, among which tumor characteristics such as tumor type, size and location play an important role. With all the advantages offered by ultrasound guidance, the overall sensitivity of this method in the tumor diagnosis has remained around 90%. Contrast enhanced ultrasound (CEUS) guided percutaneous biopsy is a new developed technique aimed at increasing the accuracy of percutaneous biopsies. With new ultrasound devices comprising the split-screen mode, which displays both the CEUS and background B-mode US image simultaneously on a single monitor, the procedure is now technically feasible. CEUS guided percutaneous liver biopsy should be applied in large tumors with consistent necrosis, in hypovascular tumors or in those invisible or poorly visible to conventional ultrasound. An increased accuracy was demonstrated in poorly visible or invisible hepatic lesions and when CEUS was used before biopsy.

Contrast enhanced ultrasound guidance: a new tool to improve accuracy in percutaneous biopsies.

The performance of percutaneous echoguided biopsy in the tumoral diagnosis is limited by several factors, among which tumor characteristics such as tumor type, size and location play an important role. With all the advantages offered by the ultrasound guidance, the overall sensitivity of this method in the tumoral diagnosis of tumor has remained around 90%. Contrast enhanced ultrasound guided percutaneous biopsy is a new developed technique aimed to increase the acurracy of percutaneous biopsies. With new ultrasound devices with split-screen mode, which displays both the CEUS and background B-mode US image simultaneously, on a single monitor, the procedure is technically feasible. CEUS guided percutaneous biopsy should be applied in large tumors with consistent necrosis, in hypovascular tumors or in those invisible or poorly visible to conventional ultrasound. The increased accuracy was demonstrated in liver tumors and in prostate adenocarcinoma.

B-mode and contrast enhanced ultrasound guided biopsy of portal vein thrombosis. Value in the diagnosis of occult hepatocellular carcinoma in liver cirrhosis.

AIM: The ultrasonographic (US) detection of hepatocellular carcinoma (HCC) in patients with liver cirrhosis is based on the visualization of focal lesions. However, in some cases HCC cannot be clearly identified at US, the only sign being a portal vein thrombosis (PVT). Contrast enhanced ultrasound (CEUS) is an excellent method to characterise focal lesions and portal thrombosis in patients with liver cirrhosis. The aim of the study was to assess the value of US and CEUS -guided PVT core biopsy in the diagnosis of an occult HCC in patients with cirrhosis. MATERIAL AND METHODS: Twenty patients with cirrhosis, PVT and no focal lesion on high-resolution US were studied. In 17 cases the thrombus was interpreted as malignant at US. All patients had normal coagulation parameters. The biopsies of an intrahepatic PVT were performed using an 18G Bard needle coupled on "Biopty Gun".US and CEUS guidance was used in16 respectively 4 patients. In 10 cases with a very inhomogeneous hepatic echostructure near the PVT (coarse echo pattern) a liver biopsy from that area was performed. RESULTS: Adequate histological specimens were obtained in all cases, requiring 1 to 2 passes (mean 1.5 per patient). Only 1 patient had severe pain. No major complications were detected. The overall sensitivity of core biopsy in the diagnosis of malignant PVT was 94.4 % (17/18). The sensitivities of US and CEUS guided PVT biopsy were 92.8% (13/14) and 100% (4/4) respectively. In 6 of 10 cases with coarse echo pattern the same type of HCC was found in the surrounding parenchyma. No false positive results were noted. CONCLUSIONS: US-guided core biopsy of PVT is a safe and useful technique in the diagnosis of occult HCC in cirrhosis and should be performed in all cases with PVT with malignant US features and no evidence of focal lesions. The "coarse echo pattern" found in the vicinity of a malignant thrombus is frequently the expression of an inapparent, occult HCC. CEUS guided PVT biopsy is a new, promising method with excellent results in establishing the nature of a portal thrombus.

Gastric stromal tumor: a rare cause of upper gastrointestinal bleeding.

Gastrointestinal stromal tumors (GISTs) are a subset of gastrointestinal mesenchymal tumors, though relatively rare in absolute terms. They are characterized by a remarkable cellular variability and their malignant potential is sometimes difficult to predict. We report a case of gastric stromal tumor in a 66 year old patient with a long history of anemia and intermitent upper gastrointestinal bleeding. We performed upper gastro-intestinal endoscopy, biopsy of gastric mucosa and abdominal ultrasonography to establish the diagnosis. The gastric tumor was successfully resected with a postoperative favourable outcome.