Travel-related schistosomiasis can be detected in patients without symptoms of acute or chronic infection. A case of Schistosoma mekongi acquired in an endemic area of Laos and discovered unexpectedly from colon biopsies taken 5 years after infection is presented here. A literature review of previous cases of S. mekongi infection specifically associated with travelers is then presented.

This paper introduces a new field application for the automation of hydrogen sulfide chemical scavenger injection systems in natural gas pipelines. The automated system combines currently available technology into a cost saving tool that has proven itself reliable in maintaining the level of hydrogen sulfide needed for contract gas sales. The benefits that an automated system provides are multi-faceted. These benefits are shown in the savings of man-hours, safety, and chemical usage optimization. Eliminating the need for intermittent checks of the hydrogen sulfide level and chemical pump adjustments saves employee time. Safety is improved due to the fact that the employee does not have to manually check the hydrogen sulfide level, thus not opening valves that would release natural gas containing hydrogen sulfide. The automated system also optimizes chemical usage by continually monitoring the system and maintaining the hydrogen sulfide content at the level needed for gas sales. The content of hydrogen sulfide in a natural gas gathering system is a dynamic and continually changing system due to several factors, i.e. new wells brought online, wells being shut in for various reasons, and the changing hydrogen sulfide level in individual wells. This system will automatically adjust for these continuous variations and lead to significant savings in hydrogen sulfide scavenger chemical applications. Introduction Hydrogen sulfide gas may be present in natural gas production as a contaminant. The amount of hydrogen sulfide may vary widely with the field composition and is usually the result of bacterial digestion of sulfates present in production waters. Hydrogen sulfide (H2S) is a highly toxic, colorless gas that is heavier than air. At low concentrations, H2S has a detectable odor of rotten eggs. As concentrations of H2S increase in the atmosphere, the ability to detect the gas by sense of smell is diminished by paralysis of the Olfactory Nerve. The toxicity of H2S is related to concentration of the gas in the atmosphere and the term of the exposure. The level of hydrogen sulfide gas at which extended daily exposure may result in a health risk is 10 parts per million. At 300 ppm, the gas is considered immediately dangerous to life and health (IDLH). High levels of H2S potentially result in paralysis of the respiratory system and death. In addition, hydrogen sulfide gas is soluble in water and hydrocarbons. It can accumulate in produced water tanks and field condensate, posing a potential for exposure of field personnel. Hydrogen sulfide gas is also corrosive to metals, which may result in reduced service life of the field equipment. Natural gas gathering system operators and pipeline companies are aware of the potential for corrosion in transportation and in final use of the natural gas. As a result of these properties of H2S, sales gas is usually limited to 4 parts per million of H2S in the product. Chemical compounds are used to remove H2S in excess of this limit. Accurate monitoring of the hydrogen sulfide content of the sales gas is required. Monitoring Techniques. The level of hydrogen sulfide in natural gas can be detected by many methods. For our purposes, we needed a method that was highly reproducible, reliable for unattended operation in a field environment, and able to result in a 4–20 mA signal for monitoring and control. The easiest method for analyzing for H2S in gas pipelines involves the use of detector tubes. The detector tube is usually a glass tube containing chemical adsorbent that discolors on contact with H2S. The amount of H2S is indicated by the length of the discoloration of the media in the tube. Errors in the results occur from difficulty in accurately reading the color change, interference from other compounds in the natural gas, and expected variance in the manufacturing of the tubes. In addition, our field trials of various brands of tubes indicated significant and unacceptable differences between brands.

Purpose: Virtual reality (VR) has both a non-pharmacological analgesic and anxiolytic action that can be used as an alternative to general anesthesia for very high-risk patients. Case report: We present here the case of a patient treated for a complex endovascular thoracoabdominal aortic aneurysm exclusion using a 4-fenestrated aortic endograft using VR. The patient had no postoperative complications and was safely discharged from the hospital on postoperative day 6. Conclusion: This case demonstrates that the use of VR in addition to local anesthesia can be a safe alternative to general anesthesia