ABSTRACT
Sulfidation is a major transformation product for manufactured silver nanoparticles (Ag-MNPs) in the wastewater treatment process.We studied the dissolution, uptake, and toxicity of Ag-MNP and sulfidized Ag-MNPs (sAg-MNPs) to a model soil organism, Caenorhabditis elegans. Our results show that reproduction was the most sensitive endpoint tested for both Ag-MNPs and sAg-MNPs. We also demonstrate that sulfidation not only decreases solubility of Ag-MNP, but also reduces the bioavailability of intact sAg-MNP. The relative contribution of released Ag(+) compared to intact particles to toxicity was concentration dependent. At lower total Ag concentration, a greater proportion of the toxicity could be explained by dissolved Ag, whereas at higher total Ag concentration, the toxicity appeared to be dominated by particle specific effects.
Subject(s)
Caenorhabditis elegans/drug effects , Metal Nanoparticles/toxicity , Silver/toxicity , Water Pollutants, Chemical/toxicity , Animals , Biological Availability , Caenorhabditis elegans/metabolism , Metal Nanoparticles/analysis , Nanoparticles , Silver/analysis , Silver/metabolism , Soil , Solubility , Waste Disposal, Fluid , Wastewater , Water Pollutants, Chemical/analysisABSTRACT
In-Water Recompression (IWR) is defined as a treatment of decompression sickness by immediate underwater recompression after the onset of symptoms in remote areas where hyperbaric chambers are not available. At least three methods of IWR have been published. They used pure oxygen breathing for prolonged periods of time at a depth of 9 m. IWR effectiveness in comparison with standard recompression techniques has not been assessed. IWR should be used in remote localities as an immediate measure to stop the evolution of decompression illness before evacuating the victim for subsequent treatment to the nearest hyperbaric facility. Resulting from environmental conditions, the risks of drowning and hypothermia are the most often quoted, pure oxygen breathing at 9 m can also expose to acute oxygen toxicity. The objectives of this work are: first, to examine existing published methods of IWR; second, to propose a new method of IWR. All published methods of IWR involve victim returning underwater for a long period of time. But dehydration due to a long period of immersion can worsen symptoms of decompression illness and acute oxygen toxicity is also related to the duration of the exposition. In response to these considerations we developed a shorter method of conducting IWR specifically targeted for a diving mission at Clipperton atoll in the Northern Pacific Ocean.
Subject(s)
Decompression Sickness/therapy , Animals , Clinical Protocols , Clinical Trials as Topic , Decompression Sickness/physiopathology , Dehydration/etiology , Diving/physiology , Humans , Oxygen/administration & dosage , Oxygen/adverse effects , Oxygen/therapeutic useABSTRACT
OBJECTIVE: To evaluate the incidence of the hemidiaphragmatic paresis after inter Sterno-Cleido-Mastoid (inter-SCM) block. STUDY DESIGN: Prospective, comparative, single blind study. PATIENTS: 16 patients ASA I-II. METHODS: The diaphragmatic paresis was measured by a radiologist unaware of the technique used and operated side. It was determined by the diaphragmatic excursion (DE) on double-exposure chest radiography, obtained preoperatively and postoperatively (DE-pre, DE-post) for the ipsilateral and controlateral side of the inter-SCM block. All the patients were given 20 mL 0.5% bupivacaine plus 20 mL 2% lidocaine both with epinephrine. These anesthetics were injected via the stimuling needle or via the catheter after opacified radiological control of the catheter position. The patients were divided into 2 groups. Group 1: injection via the needle after eliciting flexion of fingers, or via a catheter into infraclavicular position; group 2: injection via the needle after eliciting contraction of deltoid, or elbow flexion, or via a supraclavicular catheter. RESULTS: All the patients had satisfactory block. The ipsilateral DE was decreased after injection of anesthetics in group 2 (P < 0.001) while it remained unchanged in group 1. CONCLUSION: The diaphragmatic paresis is avoidable with the inter-SCM block if and only if the anesthetic solution is injected via the needle after stimulating flexion of fingers or via a catheter into infraclavicular position.
Subject(s)
Anesthetics, Local/adverse effects , Injections, Intramuscular/methods , Neck Muscles , Nerve Block/adverse effects , Phrenic Nerve/injuries , Respiratory Paralysis/etiology , Adult , Brachial Plexus , Bupivacaine/adverse effects , Female , Fingers , Humans , Injections, Intramuscular/adverse effects , Lidocaine/adverse effects , Male , Middle Aged , Posture , Prospective Studies , Respiratory Paralysis/prevention & control , Single-Blind MethodABSTRACT
OBJECTIVE: To describe a new midfemoral lateral approach for the sciatic nerve block. Its combination with the "3 in 1" block was tested for postoperative analgesia following major surgery of the knee. STUDY DESIGN: Descriptive, anatomical and clinical study prospective. PATIENTS: After testing in four unembalmed corpses the new approach was applied to 42 ASA 1-2 patients, in combination with a continuous "3 in 1" block. METHODS: The new approach was analysed for reliability of the surface landmarks (a line drawn from the posterior margin of the greater trochanter towards the knee and parallel to the femur) and block extent assessed on the foot. Its combination with the "3 in 1" block was evaluated with a visual analogue scale (VAS) scoring, for postoperative analgesia after total knee arthroplasty. RESULTS: The sciatic nerve was located in less than 10 min. A block of the sciatic nerve was fully achieved in all patients. Its median duration was 16 h. The median VAS score at rest was 0 mm (sciatic bloc + continuous block "3 in 1"), but increased to 40 mm (block "3 in 1" alone). CONCLUSION: The new lateral midfemoral sciatic block is easy to master. Combined with a continuous "3 in 1" block, it provides excellent analgesia during the early postoperative period after major surgery of the knee.
Subject(s)
Knee Joint/surgery , Nerve Block/methods , Sciatic Nerve , Adult , Aged , Analgesia/methods , Anesthetics, Local/administration & dosage , Arthroplasty, Replacement, Knee , Bupivacaine/administration & dosage , Cadaver , Female , Femoral Nerve/anatomy & histology , Femoral Nerve/drug effects , Foot/innervation , Humans , Leg/innervation , Lidocaine/administration & dosage , Male , Pain Measurement , Pain, Postoperative/prevention & control , Prospective Studies , Reproducibility of Results , Sciatic Nerve/anatomy & histology , Sciatic Nerve/drug effects , Tibial Nerve/drug effectsABSTRACT
This article raises questions about the ways culture affects the nature of health care services. By examining the life story of Alma, a Central American woman who has a daughter with disabilities; her interactions with health care providers; and my own assumptions about cultural differences, I note the impact of cultural differences on coping and adaptation in Alma and in the health care system when working with poor, non-English-speaking clients.
