Quantitative Nanoscale Absorption Mapping: A Novel Technique To Probe Optical Absorption of Two-Dimensional Materials.

Two-dimensional semiconductors, in particular transition metal dichalcogenides and related heterostructures, have gained increasing interest as they constitute potential new building blocks for the next generation of electronic and optoelectronic applications. In this work, we develop a novel nondestructive and noncontact technique for mapping the absorption properties of 2D materials, by taking advantage of the underlying substrate cathodoluminescence emission. We map the quantitative absorption of MoS2 and MoSe2 monolayers, obtained on sapphire and oxidized silicon, with nanoscale resolution. We extend our technique to the characterization of the absorption properties of MoS2/MoSe2 van der Waals heterostructures. We demonstrate that interlayer excitonic phenomena enhance the absorption in the UV range. Our technique also highlights the presence of defects such as grain boundaries and ad-layers. We provide measurements on the absorption of grain boundaries in monolayer MoS2 at different merging angles. We observe a higher absorption yield of randomly oriented monolayers with respect to 60° rotated monolayers. This work opens up a new possibility for characterizing the functional properties two-dimensional semiconductors at the nanoscale.

Eco-efficiency assessment of farm-scaled biogas plants.

The aim of this study was to analyse the eco-efficiency of 15 agricultural biogas plants located in Northern Italy. For this, the combination of life cycle assessment (LCA) and data envelopment analysis (DEA) methodologies was considered with the purpose of identifying efficient operational plants and proposing improvement measures for the inefficient ones. The environmental profile of both the original and the virtual plants (obtained after the improvement measures) were compared in order to identify the net environmental gains linked with the inputs reduction. As a result of improvement measures, the production of electricity from biogas in all plants would imply environmental benefits compared with the average electricity production in the Italian grid. In light of the results obtained, special attention should be paid to the feedstock selection since it has a key role in the overall eco-efficiency of the plant, due to their different origin and composition.

Fournier's gangrene: Clinical case and review of the literature.

Fournier's gangrene is a life-threatening acute necrotizing fasciitis of perianal,genitourinary and perineal areas. Nowadays, is well known that Fournier gangrene is almost never an idiopathic disease. In this article we report a case of a 70-year-old patient that initially was not treated properly. The gold standard therapy of the Fournier's gangrene remains today a complete, early and extended surgical debridement.

Role of the JP45-Calsequestrin Complex on Calcium Entry in Slow Twitch Skeletal Muscles.

We exploited a variety of mouse models to assess the roles of JP45-CASQ1 (CASQ, calsequestrin) and JP45-CASQ2 on calcium entry in slow twitch muscles. In flexor digitorum brevis (FDB) fibers isolated from JP45-CASQ1-CASQ2 triple KO mice, calcium transients induced by tetanic stimulation rely on calcium entry via La(3+)- and nifedipine-sensitive calcium channels. The comparison of excitation-coupled calcium entry (ECCE) between FDB fibers from WT, JP45KO, CASQ1KO, CASQ2KO, JP45-CASQ1 double KO, JP45-CASQ2 double KO, and JP45-CASQ1-CASQ2 triple KO shows that ECCE enhancement requires ablation of both CASQs and JP45. Calcium entry activated by ablation of both JP45-CASQ1 and JP45-CASQ2 complexes supports tetanic force development in slow twitch soleus muscles. In addition, we show that CASQs interact with JP45 at Ca(2+) concentrations similar to those present in the lumen of the sarcoplasmic reticulum at rest, whereas Ca(2+) concentrations similar to those present in the SR lumen after depolarization-induced calcium release cause the dissociation of JP45 from CASQs. Our results show that the complex JP45-CASQs is a negative regulator of ECCE and that tetanic force development in slow twitch muscles is supported by the dynamic interaction between JP45 and CASQs.

Evaluation of anaerobic degradation, biogas and digestate production of cereal silages using nylon-bags.

In this study, the degradation efficiency and the biogas and digestate production during anaerobic digestion were evaluated for the cereal silages most used to feed biogas plants. To this purpose, silages of: maize from the whole plant, maize from the ear, triticale and wheat were digested, inside of nylon bags, in laboratory scale digesters, for 75days. Overall, the test involved 288 nylon bags. After 75days of digestion, the maize ear silage shows the highest degradation efficiency (about 98%) while wheat silage the lowest (about 83%). The biogas production ranges from 438 to 852Nm(3)/t of dry matter for wheat and ear maize silage, respectively. For all the cereal silages, the degradation as well as the biogas production are faster at the beginning of the digestion time. Digestate mass, expressed as percentage of the fresh matter, ranges from 38% to 84% for wheat and maize ear silage, respectively.

Pancreaticojejunostomy Versus Pancreaticogastrostomy After Pancreaticoduodenectomy: An Up-to-date Meta-Analysis.

BACKGROUND: The reconstruction of the pancreas after pancreaticoduodenectomy (PD) is a crucial factor in preventing postoperative complications as pancreatic anastomosis failure is associated with a high morbidity rate and contributes to prolonged hospitalization and mortality. Several techniques have been described for the reconstruction of pancreatic digestive continuity in the attempt to minimize the risk of a pancreatic fistula. The aim of this study was to compare the results of pancreaticogastrostomy and pancreaticojejunostomy after PD. METHODS: A systematic review and meta-analysis were conducted of randomized controlled trials (RCTs) published up to January 2015 comparing patients with pancreaticogastrostomy (PG group) versus pancreaticojejunostomy (PJ group). Two reviewers independently assessed the eligibility and quality of the studies. The meta-analysis was conducted using either the fixed-effect or the random-effect model. RESULTS: Eight RCTs describing 1,211 patients were identified for inclusion in the study. The meta-analysis shows that the PG group had a significantly lower incidence rate of postoperative pancreatic fistulas [OR 0.64 (95% confidence interval 0.46-0.86), p = .003], intra-abdominal abscesses [OR 0.53 (95% CI, 0.33-0.85), p = .009] and length of hospital stay [MD -1.62; (95% CI 2.63-0.61), p = .002] than the PJ group, while biliary fistula, mortality, morbidity, rate of delayed gastric emptying, reoperation, and bleeding did not differ between the two groups. CONCLUSION: This meta-analysis suggests that the most effective treatment for reconstruction of pancreatic continuity after pancreatoduodenectomy is pancreaticogastrostomy. However, the advantage of the latter could potentially be demonstrated through further RCTs, including only patients at high risk of developing pancreatic fistulas.

Assessment of the influence of energy density and feedstock transport distance on the environmental performance of methane from maize silages.

In Europe, thanks to public subsidy, the production of electricity from anaerobic digestion (AD) of agricultural feedstock has considerably grown and several AD plants were built. When AD plants are concentrated in specific areas (e.g., Northern Italy), increases of feedstock' prices and transport distances can be observed. In this context, as regards low-energy density feedstock, the present research was designed to estimate the influence of the related long-distance transport on the environmental performances of the biogas-to-electricity process. For this purpose the following transport systems were considered: farm trailers and trucks. For small distances (<5 km), the whole plant silage shows the lowest impact; however, when distances increase, silages with higher energy density (even though characterised by lower methane production per hectare) become more environmentally sustainable. The transport by trucks achieves better environmental performances especially for distances greater than 25 km.

Mitigation strategies in the agro-food sector: The anaerobic digestion of tomato purée by-products. An Italian case study.

Tomato processing involves a significant production of residues, mainly constituted by discarded tomatoes, skins, seeds and pulp. Often, these residues are not valorized and represent an added cost for manufacturing companies because of disposal processes, with environmental issues due to the difficult management. The exploitation of these residual materials results complex as their availability is mainly concentrated in few months. A possible solution is the production of biogas employed in a Combine Heat and Power engine for energy production, in line with the 2020 targets of European Union in terms of promotion of energy from renewable resources and greenhouse gas emission reduction. The tomato by-product utilization for energy production as a strategy to reduce the environmental load of tomato purée was evaluated by means of Life Cycle Assessment. Two scenarios were considered: Baseline Scenario - tomato by-products are sent back to the tomato fields as organic fertilizers; Alternative Scenario - tomato by-products are employed in a nearby biogas plant for energy production. Methane production of tomato by-products was assessed by means of specific laboratory tests. The comparison between the two scenarios highlighted reductions for all the impact categories with the Alternative Scenario. The most important reductions are related to particulate matter (-5.3%), climate change (-6.4%) and ozone depletion (-13.4%). Although small, the reduction of the environmental impact cannot be neglected; for example for climate change, the anaerobic digestion of by-products allows a saving of GHG emissions that, over the whole year, is equal to 1.567 tons of CO2 eq. The results of this study could be up-scaled to the food industries with high heat demand producing considerable amounts of fermentable by-products employable as feedstock for biogas production.

Environmental assessment of farm-scaled anaerobic co-digestion for bioenergy production.

The aim of this study was to assess the environmental profile of a bioenergy system based on a co-digestion plant using maize silage and pig slurry as substrates. All the processes involved in the production of bioenergy as well as the avoided processes accrued from the biogas production system were evaluated. The results evidenced the environmental importance of the cultivation step and the environmental credits associated to the avoided processes. In addition, this plant was compared with two different plants that digest both substrates separately. The results revealed the environmental benefits of the utilisation of pig slurry due to the absence of environmental burdens associated with its production as well as credits provided when avoiding its conventional management. The results also presented the environmental drawbacks of the utilisation of maize silage due to the environmental burdens related with its production. Accordingly, the anaerobic mono-digestion of maize silage achieved the worst results. The co-digestion of both substrates was ranked in an intermediate position. Additionally, three possible digestate management options were assessed. The results showed the beneficial effect of digestate application as an organic fertiliser, principally on account of environmental credits due to avoided mineral fertilisation. However, digestate application involves important acidifying and eutrophicating emissions.

Abdominal wall desmoid tumors: A proposal for US-guided resection.

BACKGROUND: Desmoid tumors (DTs) is a benign tumor with high tendency to infiltrative evolution and recurrence. Nowadays, in abdominal localization, the standard approach is surgery with R0 condition. The need to repair post-surgical wide wall defect requires conservative technique to decrease the incidence of incisional hernia and to obtain better quality of life (QoL). METHODS: We perform an abdominal wall desmoid resection using ultrasound guide. This technique ensures to spare a wide wall area and to obtain a multilayer reconstruction minimizing postoperative risk. This approach allows good oncological results and better managing abdominal wall post-resection defect. RESULTS: We use US guided surgery to get radical approach and wall tissue spare that allows us a multilayer reconstruction minimizing post-operative complications. No recurrences were observed in one year follow up period. CONCLUSION: Our experience represents first step to consider ultrasound mediated technique usefull to optimize wall resection surgery and to minimize following complications.

Carbon-doped SiO(x) nanowires with a large yield of white emission.

The growth of SiOx nanowires (NWs) with intense white emission is reported. Due to carbon monoxide gas being used as a dopant precursor, carbon-doped under-stoichiometric silicon dioxide NWs are obtained. The doping of the NWs is studied by means of x-ray photoelectron spectroscopy, which allows to assess the presence of carbon atoms in the silicon oxide amorphous structure. The light emission properties are studied by means of cathodoluminescence spectroscopy, which shows three main emission bands set at 2.7 eV (blue), 2.3 eV (green) and 1.9 eV (red), resulting in the white emission.

Environmental assessment of two different crop systems in terms of biomethane potential production.

The interest in renewable energy sources has gained great importance in Europe due to the need to reduce fossil energy consumption and greenhouse gas emissions, as required by the Renewable Energy Directive (RED) of the European Parliament. The production of energy from energy crops appears to be consistent with RED. The environmental impact related to this kind of energy primarily originates from crop cultivation. This research aimed to evaluate the environmental impact of different crop systems for biomass production: single and double crop. The environmental performances of maize and maize plus wheat were assessed from a life cycle perspective. Two alternative scenarios considering different yields, crop management, and climatic conditions, were also addressed. One normal cubic metre of potential methane was chosen as a functional unit. Methane potential production data were obtained through lab experimental tests. For both of the crop systems, the factors that have the greatest influence on the overall environmental burden are: fertilizer emissions, diesel fuel emissions, diesel fuel production, and pesticide production. Notwithstanding the greater level of methane potential production, the double crop system appears to have the worse environmental performance with respect to its single crop counterpart. This result is due to the bigger quantity of inputs needed for the double crop system. Therefore, the greater amount of biomass (silage) obtained through the double crop system is less than proportional to the environmental burden that results from the bigger quantity of inputs requested for double crop.

Sanitation ability of anaerobic digestion performed at different temperature on sewage sludge.

A small amount of ammonia is used in full-scale plants to partially sanitize sewage sludge, thereby allowing successive biological processes to enable the high biological stability of the organic matter. Nevertheless, ammonia and methane are both produced during the anaerobic digestion (AD) of sludge. This paper describes the evaluation of a lab-scale study on the ability of anaerobic process to sanitize sewage sludge and produce biogas, thus avoiding the addition of ammonia to sanitize sludge. According to both previous work and a state of the art full-scale plant, ammonia was added to a mixture of sewage sludge at a rate so that the pH values after stirring were 8.5, 9 and 9.5. This procedure determined an ammonia addition lower than that generally indicated in the literature. The same sludge was also subjected to an AD process for 60 days under psychrophilic, mesophilic and thermophilic conditions. The levels of fecal coliform, Salmonella spp. helmints ova, pH, total N, ammonia fractions and biogas production were measured at different times during each process. The results obtained suggested that sludge sanitation can be achieved using an AD process; however, the addition of a small amount of ammonia was not effective in sludge sanitation because the buffer ability of the sludge reduced the pH and thus caused ammonia toxicity. Mesophilic and thermophilic AD sanitized better than psychrophilic AD did, but the total free ammonia concentration under the thermophilic condition inhibited biogas production. The mesophilic condition, however, allowed for both sludge sanitation and significant biogas production.

Anaerobic digestion of different feedstocks: impact on energetic and environmental balances of biogas process.

The possibility of limiting the global warming is strictly linked to the reduction of GHG emissions. Renewable energy both allows reducing emissions and permits to delay fossil fuel depletion. The anaerobic digestion of animal manure and energy crops is a promising way of reducing GHG emissions. In Italy agricultural biogas production was considerably increased; nowadays there are about 520 agricultural biogas plants. The increasing number of biogas plants, especially of those larger than 500 kW(e) (electrical power), involves a high consumption of energy crops, large transport distances of biomass and digestate and difficulties on thermal energy valorization. In this study the energetic (CED) and environmental (GHG emissions) profiles associated with the production of electricity derived from biogas have been identified. Three biogas plants located in Northern Italy have been analyzed. The study has been carried out considering a cradle-to-grave perspective and thus, special attention has been paid on the feedstock production and biogas production process. The influences on the results taking into account different plant sizes and feeding rate has been assessed in detail. Energy analysis was performed using the Cumulative Energy Demand method (CED). The climate change was calculated for a 100-year time frame based on GHG emissions indicated as CO2 equivalents (eq) and defined by the IPCC (2006). In comparison to the fossil reference system, the electricity production using biogas saves GHG emissions from 0.188 to 1.193 kg CO2eq per kWh(e). Electricity supply from biogas can also contribute to a considerable reduction of the use of fossil energy carriers (from -3.97 to 10.08 MJ(fossil) per kWh(e)). The electricity production from biogas has a big potential for energy savings and reduction of GHG emissions. Efficient utilization of the cogenerated heat can substantially improve the GHG balance of electricity production from biogas.

Choledocholithiasis and endo-laparoscopic rendezvous. Analysis of 59 consecutive cases.

BACKGROUND: Choledocholithiasis is a real problem of major clinical importance. The incidence of cholelithiasis is 10-20%. MATERIALS: We have examined 2907 patients treated with videolaparoscopic cholecystectomy (VLC) between January 2001 and September 2009. 214 cases (7.4%) were affected by choledocolithiasis; among these, 59 consecutive cases were treated by rendezvous, 151 cases by sequential treatment (ERCP-ES before VLC), 3 cases by extraction with Dormia's basket, and 1 case by ERCP-ES after VLC. RESULTS: The complications were one biliary fistula and three hemorrhages (one from the cystic artery, one from the hepatic area and one from trocar's site). The mean hospital stay was 1.38 +/- 0.83 days for the rendezvous group vs 4 53 +/- 0.74 days in the sequential treatment group (p<0.004). The satisfaction scores were 6.6 +/- 1.39 versus 5.7 +/- 0.96 (p<0.004). CONCLUSIONS: The rendezvous procedure reduces hospital stay and has a greater compliance (only one treatment). We can use this option in the management of cases where preoperative ERCP-ES has failed.

Groundwater remediation by an in situ biobarrier: a bench scale feasibility test for methyl tert-butyl ether and other gasoline compounds.

Most gasoline contains high percentages of methyl tert-butyl ether (MTBE) as an additive. The physico-chemical properties of this substance (high water solubility, low sorption in soil) result in high mobility and dissolved concentrations in soil. In situ permeable biological barriers (biobarriers, BBs) can remediate MTBE polluted groundwater by allowing pure cultures or microbial consortia to degrade MTBE when aerobic conditions are present, either by direct metabolism or cometabolism. Lab-scale batch and column tests were carried out to assess a selected microbial consortium in biodegrading MTBE and other gasoline compounds (benzene B, toluene T, ethylbenzene E, xylenes X) and to measure the parameters affecting the efficacy of a BB treatment of polluted groundwater. During the aerobic phase of the batch tests, the simultaneous biodegradation of MTBE, tert-butyl alcohol (TBA), B, T, E and o-X was observed. The rapid biodegradation of BTEXs resulted in decreased oxygen availability, but MTBE degradation was nevertheless measured in the presence of BTEXs. Stationary concentrations of MTBE and TBA were measured when anoxic conditions occurred in the systems. Values for a first order kinetic removal process were obtained for MTBE (0.031+/-0.001 d(-1)), B (0.045+/-0.002 d(-1)) and T (0.080+/-0.004 d(-1)) in the inoculated column tests. The estimate of the BB design parameters suggested that inoculation could significantly modify (double) the longitudinal dispersivity value of the biomass support medium. No effect was observed in the retardation factors for MTBE, B and T.

Decision making in patients with acute abdominal pain at a university and at a rural hospital: does the value of abdominal sonography differ?

INTRODUCTION AND OBJECTIVES: Abdominal sonography is regarded as a quick and effective diagnostic tool for acute abdominal pain in emergency medicine. However, final diagnosis is usually based on a combination of various clinical examinations and radiography. The role of sonography in the decision making process at a hospital with advanced imaging capabilities versus a hospital with limited imaging capabilities but more experienced clinicians is unclear.The aim of this pilot study was to assess the relative importance of sonography and its influence on the clinical management of acute abdominal pain, at two Swiss hospitals, a university hospital (UH) and a rural hospital (RH). METHODS: 161 patients were prospectively examined clinically. Blood tests and sonography were performed in all patients. Patients younger than 18 years and patients with trauma were excluded. In both hospitals, the diagnosis before and after ultrasonography was registered in a protocol. Certainty of the diagnosis was expressed on a scale from 0% to 100%.The decision processes used to manage patients before and after they underwent sonography were compared. The diagnosis at discharge was compared to the diagnosis 2 - 6 weeks thereafter. RESULTS: Sensitivity, specificity and accuracy of sonography were high: 94%, 88% and 91%, respectively.At the UH, management after sonography changed in only 14% of cases, compared to 27% at the RH. Additional tests were more frequently added at the UH (30%) than at the RH (18%), but had no influence on the decision making process-whether to operate or not. At the UH, the diagnosis was missed in one (1%) patient, but in three (5%) patients at the RH. No significant difference was found between the two hospitals in frequency of management changes due to sonography or in the correctness of the diagnosis. CONCLUSION: Knowing that sonography has high sensitivity, specificity and accuracy in the diagnosis of acute abdominal pain, one would assume it would be an important diagnostic tool, particularly at the RH, where tests/imaging studies are rare.However, our pilot study indicates that sonography provides important diagnostic information in only a minority of patients with acute abdominal pain.Sonography was more important at the rural hospital than at the university hospital. Further costly examinations are generally ordered for verification, but these additional tests change the final treatment plan in very few patients.

Resecting the great saphenous stump with endothelial inversion decreases neither neovascularization nor thigh varicosity recurrence.

BACKGROUND: Neovascularization at the saphenofemoral junction is one of the principal causes of recurrent varicose veins after great saphenous vein surgery. Because angiogenic stimulation from the exposed endothelium of the great saphenous vein stump is considered an important trigger for this process, we hypothesized that complete resection of the stump with endothelial inversion might lessen grade 2 groin neovascularization and thereby decrease recurrence of thigh varicosities. METHODS: Two groups of consecutive patients with primary varicose veins of the great saphenous vein were studied. Group A was a historical control group of 70 limbs (48 patients) in which conventional flush ligation was performed at the level of the saphenofemoral junction. Group B was a prospectively studied clinical trial cohort of 65 limbs (45 patients), wherein the great saphenous vein stump was completely resected using a side-biting clamp to isolate the saphenofemoral junction, and the resulting common femoral vein venotomy was closed with a running inverting suture. Early postoperative follow-up was performed at 6 weeks. Clinical examinations and duplex ultrasound scans were performed after 2 years of follow-up. Grade 2 groin neovascularization was defined by the presence of >3 mm tortuous new refluxing veins, typically communicating with recurrent varicosities in the thigh. RESULTS: After 2 years, recurrent varicose veins were present in the thighs of 13 of 65 limbs (20%) in group A and in 22 of 61 limbs (36%) of group B (P = .049). Grade 2 neovascularization was present at the saphenofemoral junction in six of 65 limbs (9%) of group A and in 12 of 61 limbs (20%) of group B (P = .127). CONCLUSION: Complete resection of the great saphenous vein stump and inversion suturing of the common femoral vein venotomy, instead of simple flush ligation at the level of the saphenofemoral junction, do not appear to decrease grade 2 neovascularization and related thigh varicosity recurrence after great saphenous vein stripping for primary varicose veins.

Acute abdomen caused by a perforated inflammatory myofibroblastic tumor of the jejunum.

Inflammatory myofibroblastic tumors are rare pseudosarcomatous tumors found in virtually all anatomic sites. Our case report describes an elderly female patient with an inflammatory myofibroblastic tumor in the proximal jejunum, accidentally discovered at laparotomy for an acute abdomen. The localization in the jejunum is a very rare finding, and perforation has not been described before.