The use of the cap and underwater technique as an aid in endoscopic diagnosis and treatment of upper gastrointestinal bleeding: case series.

BACKGROUND AND AIMS: Upper GI bleeding (UGIB) is a medical emergency associated with elevated mortality and significant costs to the health care system. EGD is currently the method of choice for the diagnosis and management of these conditions. However, the location of bleeding lesions and technical difficulties in achieving endoscope stability may challenge even the most experienced endoscopists. Herein, we demonstrate the use of the cap and underwater technique as a helpful aid in these situations. METHODS: We present a case series of 4 patients with acute UGIB who underwent EGD with suboptimal endoscopic visualization or technical difficulties in identifying the source of bleeding. A transparent plastic cap was attached to the distal tip of the gastroscope, and the water immersion technique (underwater) was used for endoscopic re-evaluation of the bleeding site. RESULTS: Three patients presented with duodenal bleeding, and 1 was diagnosed with diffuse bleeding from the esophagus. The clear and accurate identification of the source of bleeding and effective hemostasis were possible after cap and underwater technique evaluation in all patients. CONCLUSION: The use of the cap and underwater technique is a simple, safe, and low-cost strategy that improves the identification and control of UGIB in locations with poor visibility and technical challenges during endoscopic evaluation.

Rare earth elements in drill cutting samples from off-shore oil and gas exploration activities in ultradeep waters.

Rare earth elements (REEs) are essential in high technology industries and have great economic value. The monitoring of REEs concentrations in rocks from oil well drill cuttings is critical to avoid environmental contamination and evaluate new sources of these elements. However, information is scarce about the REEs concentrations in drill cuttings. In this work, the concentration of REEs in drill cuttings from oil and gas exploration wells in ultradeep coastal water of Brazilian were investigated at different depths. The drill cutting samples were submitted to microwave-assisted acid digestion prior to the determination of concentration by ICP-MS, using Rh as internal standard for calibration. The limits of quantification (LoQ) ranged from 3.3 µg kg-1 for Ho to 198 µg kg-1 for Sm. The accuracy was evaluated by analyzing certified reference materials for rocks. The obtained REEs concentrations agreed with the certified values, reaching 83%-105% agreement. The drill cutting depth profile analysis indicates Ce, La, Nd, Sm, and Eu concentrations up to mg kg-1. The REEs concentrations obtained in drill cutting depth profile was analyzed by principal component analysis (PCA), and hierarchical cluster analysis (HCA) identified tendency and similarity between drill cutting samples. Three groups were formed according to the composition of the REEs. In addition, the concentration of these chemicals elements varied at different depths. The analysis of drill cuttings revealed REEs concentrations up to the mg per kg-range (ppm), potentially making this disposable material an alternative source for REEs extraction, and adding value to this material.

Recovery of lanthanides from hydrocarbon cracking spent catalyst through chemical and biotechnological strategies.

The aim of this work is to evaluate the rare earth elements (REEs) recovery from fluid catalytic cracking spent catalyst (FCC-SC) by chemical and biochemical strategies while also examining a route for the valorization of biodiesel-derived glycerin (RG), which is presently unprofitable to refine. Recovery tests for REEs were performed with no pretreatment of the FCC-SC. A chemical leaching investigation was carried out using HCl, HNO3, NaOH, CaCl2 and citric acid aqueous solutions (1 mol L-1, at 30, 50, 60 or 70 ± 1 °C). The leaching tests carried out with 1 mol L-1 citric acid at 50 °C provided the best recovery of La (27%). Subsequent bioleaching tests were carried out with four strains of Yarrowia lipolytica to evaluate their potential to produce organic acids using RG as the main carbon source. The FCC-SC contains some REEs, predominantly La. Remarkable biorecovery rates for REEs (namely, La (53%), Ce and Nd (both 99%)) were achieved using the Y. lipolytica IM-UFRJ 50678 fermented medium at 50 °C. Thus, here, a sustainable approach to recovering metals from spent cracking catalyst using RG under low-cost and non-energy-intensive processing conditions is reported.

Biosurfactant-assisted phytoremediation of multi-contaminated industrial soil using sunflower (Helianthus annuus L.).

This study evaluated the use of commercial rhamnolipid biosurfactant supplementation in the phytoremediation of a soil via sunflower (Helianthus annuus L.) cultivation. The soil, obtained from an industrial area, was co-contaminated with heavy metals and petroleum hydrocarbons. The remediation tests were monitored for 90 days. The best results for removal of contaminants were obtained from the tests in which the sunflower plants were cultivated in soil with 4 mg kg-1 of the rhamnolipid. Under these conditions, reductions of 58% and 48% were obtained in the total petroleum hydrocarbon (TPH) and polycyclic aromatic hydrocarbon (PAH) concentrations, respectively; reductions in the concentrations of the following metals were also achieved: Ni (41%), Cr (30%), Pb (29%), and Zn (20%). The PCR-DGGE analysis of soil samples collected before and after the treatments verified that the plant cultivation and biosurfactants supplementation had little effect on the structure of the dominant bacterial community in the soil. The results indicated that sunflower cultivation with the addition of a biosurfactant is a viable and efficient technology to treat soils co-contaminated with heavy metals and petroleum hydrocarbons.

Efficient removal of mercury from aqueous solutions and industrial effluent.

The objective of this study was to examine the ability of a solid waste produced during beneficiation of ornamental rocks to remove mercury (Hg) from an industrial effluent and aqueous solutions under various conditions. Batch studies have been carried out by observing the effects of pH, concentration of the adsorbate, contact time, and so on. Various sorption isotherm models such as Langmuir, Freundlich, and Tóth have been applied for the adsorbent. Film and intraparticle diffusion were both found to be rate-limiting steps. Adsorption was properly described by the Freundlich model (capacity constant of 0.3090 (mg g(-1))(mg L(-1))(-1/n) and adsorption intensity indicator of 2.2939), which indicated a favorable sorption and encouraged subsequent studies for treatment of Hg-containing industrial effluent. Industrial effluent treatment efficiency reached Hg removals greater than 90% by using ornamental rock solid waste (ORSW). Besides, desorption studies indicated that the maximum recovery of mercury was 100 ± 2% for 1 mol L(-1) HNO3 and 74 ± 8% for 0.1 mol L(-1) HNO3. The ORSW could be reused thrice without significant difference on the Hg removal rate from industrial effluent. These findings place ORSW as a promising efficient and low-cost adsorbent for the removal of Hg from aqueous solutions and industrial effluent.

Bioremediation of marine sediments impacted by petroleum.

The aim of this work was to optimize the bioremediation of crude oil-contaminated sand sediment through the biostimulation technique. The soil was obtained in the mid-tide zone of Guanabara Bay, Rio de Janeiro, Brazil and was artificially contaminated with crude oil at 14 g kg(-1). Bioremediation optimization was performed using an experimental design and statistical analysis of the following factors: supplementation with commercial biosurfactant Jeneil IBR 425 and commercial mineral NPK fertilizer. The response variable used was the biodegradation of the heavy oil fraction, HOF. The analysis of the studied factors and their interactions was executed using contour plots, Pareto diagram and ANOVA table. Experimental design results indicated that the supplementation with fertilizer at 100:25:25 C/N/P ratio and biosurfactant at 2 g kg(-1) yielded biodegradation of HOF at about 30% during 30 days of process. Some experiments were carried out using the experimental design results, yielding 65% of biodegradation of HOF and 100% of n- alkanes between C15 and C30 during 60 process days. Intrinsic biodegradation test was carried out, yielding 85% of biodegradation of n-alkanes between C15 and C30 during 30 days of process.

Biosurfactants production by Pseudomonas aeruginosa FR using palm oil.

Biosurfactants production by a strain of Pseudomonas aeruginosa using palm oil as a sole carbon source was investigated. The experiments were carried out in 500-mL conical flasks containing 100 mL of mineral media supplemented with palm oil as the sole carbon source. The P. aeruginosa FR strain was able to reduce surface tension of three tested inorganic media. Rotation velocities from 100 to 150 rpm provided free-cell fermented media with the lowest surface tension of approx 33 mN/m. Emulsification index results of even 100% were achieved when diesel was used as oil phase. Eight surface-active compounds produced by the bacterium were identified by mass spectrometry.

Biosurfactants production by Pseudomonas aeruginosa FR using palm oil.

Biosurfactants production by a strain of Pseudomonas aeruginosa using palm oil as a sole carbon source was investigated. The experiments were carried out in 500-mL conical flasks containing 100 mL of mineral media supplemented with palm oil as the sole carbon source. The P. aeruginosa FR strain was able to reduce surface tension of three tested inorganic media. Rotation velocities from 100 to 150 rpm provided free-cell fermented media with the lowest surface tension of approx 33 mN/m. Emulsification index results of even 100% were achieved when diesel was used as oil phase. Eight surface-active compounds produced by the bacterium were identified by mass spectrometry.

Performance of an internal-loop airlift bioreactor for treatment of hexane-contaminated air.

Hexane is a toxic volatile organic compound that is quite abundant in gas emissions from chemical industries and printing press and painting centers, and it is necessary to treat these airstreams before they discharge into the atmosphere. This article presents a treatment for hexane-contaminated air in steady-state conditions using an internal-loop airlift bioreactor inoculated with a Pseudomonas aeruginosa strain. Bioprocesses were conducted at 20-mL/min, a load of 1.26 gm3 of C6H14, and a temperature of 28 degrees C. The results of hexane removal efficiencies were presented as a function of the inoculum size (approx 0.07 and 0.2 g/L) and cell reuse. Bioprocess monitoring comprises quantification of the biomass, the surface tension of the medium, and the hexane concentration in the fermentation medium as well as in the inlet and outlet airstreams. The steady-state results suggest that the variation in inoculum size from 0.07 to 0.2 g/L promotes hexane abatement from the influent from 65 to 85%, respectively. Total hydrocarbon removal from the waste gas was achieved during experiments conducted using reused cells at an initial microbial concentration of 0.2 g/L.

Increase in removal of polycyclic aromatic hydrocarbons during bioremediation of crude oil-contaminated sandy soil.

A 23 full factorial experimental design was adopted to estimate the effects of three variables on the biodegradation of oil during soil bioremediation: bioaugmentation seeding a mixed culture, addition of fertilizer or mineral media, and correction of initial pH of the soil to 7.0. The tests were carried out in polyvinyl chloride reactors with 5.0 kg of crude oil-contaminated soil at 14 g/kg. After screening the variables, soil bioremediation tests were conduced with varied C:N ratios, yielding an increase in biodegradation of the oil heavy fraction from 24 to 65%, consumption of total n-paraffins, and a remarkable decrease in the concentration of residual polycyclic aromatic hydrocarbons of the soil.