Occurrence and ecological risk assessment of neonicotinoids and related insecticides in the Bohai Sea and its surrounding rivers, China.

Systemic insecticides like neonicotinoids and the phenylpyrazole insecticide fipronil are the most widely applied insecticides around the world. Multiple studies analyzed insecticide residues in freshwater systems, but data on seawater contamination levels are scarce. This study investigates the spatiotemporal distribution and ecological risk assessment of fipronil, neonicotinoids, sulfoxaflor and selected transformation products (TPs) in the Chinese Bohai Sea and its surrounding rivers. Well-established neonicotinoids (acetamiprid, clothianidin, imidacloprid, thiacloprid and thiamethoxam) and TPs of fipronil and imidacloprid were frequently detected (detection frequency (DF): 42-100%) in freshwater. The median total insecticide concentration in freshwater was significantly higher in summer (72.4 ng•L-1) than in fall (23.4 ng•L-1), with major contributions from neonicotinoids, suggesting that pollution originates mostly from diffuse sources. In 2018, acetamiprid, desnitro-imidacloprid, fipronil-desulfinyl and thiacloprid were abundant in seawater (DF: 47-100%), indicating a high stability of acetamiprid and thiacloprid and a rapid photodegradation of fipronil and imidacloprid in surface waters. These results indicate that the continued use of these parent compounds may lead to their accumulation and/or of their TPs in shallow coastal seas. Consequently, this may lead to their transport to open seas, increasing their potential risk to marine organisms. Similarities between contaminant fingerprints in freshwater and seawater strongly suggest riverine discharges as main pollution source of adjacent coastal areas. This is the first study to perform an ecological risk assessment of fipronil, neonicotinoids, sulfoxaflor and selected TPs on marine ecosystems. Fipronil and its TPs demonstrated to be environmentally relevant with potential high risks for aquatic species. Our study provides novel insights into the fate and ecological risk of fipronil, neonicotinoids, sulfoxaflor and their TPs to marine species in shallow coastal seas.

Evaluation of a New Workplace Protection Factor-Measuring Method for Filtering Facepiece Respirator.

BACKGROUND: This study aims to assess whether the TSI PortaCount (Model 8020) is a measuring instrument comparable with the flame photometer. This would provide an indication for the suitability of the PortaCount for determining the workplace protection factor for particulate filtering facepiece respirators. METHODS: The PortaCount (with and without the N95-Companion™) was compared with a stationary flame photometer from Moores (Wallisdown) Ltd (Type 1100), which is a measuring instrument used in the procedure for determining the total inward leakage of the particulate filtering facepiece respirator in the European Standard. Penetration levels of sodium chloride aerosol through sample respirators of two brands (A and B) were determined by the two measuring systems under laboratory conditions. For each brand, thirty-six measurements were conducted. The samples were split into groups according to their protection level, conditioning before testing, and aerosol concentration. The relationship between the gauged data from two measuring systems was determined. In addition, the particle size distribution inside the respirator and outside the respirator was documented. Linear regression analysis was used to calculate the association between the PortaCount (with and without the N95-Companion™) and the flame photometer. RESULTS: A linear relationship was found between the raw data scaled with the PortaCount (without N95-Companion™) and the data detected by the flame photometer (R2 = 0.9704) under all test conditions. The distribution of particle size was found to be the same inside and outside the respirator in almost all cases. CONCLUSION: Based on the obtained data, the PortaCount may be applicable for the determination of workplace protection factor.

Mucocutaneous blood contact: blood release behavior of safety peripheral intravenous catheters.

BACKGROUND: Protection against needlestick injuries has significantly improved in recent years thanks to so-called "safety devices." However, a potential drawback occasionally reported by users is a risk of blood splashing. If this blood comes in contact with the mucous membranes, it could lead to an infection. METHODS: Five safety peripheral intravenous catheter brands were examined in a laboratory test. To simulate the extreme situations, which may arise through human use, the introducer needle was withdrawn from the catheter at 2 different angles whereby an industrial robot was used to simulate the sequence of this movement. Each brand was tested 30 times. The experiment was carried out using radioactively labeled human whole blood. The measurements for the transmitted volume of blood was taken both from an artificial head and from a surface measuring 18.5 cm by 26.5 cm at a height of 30 cm above the catheter; scintigraphy was used to take the measurements. RESULTS: The volume of blood droplets potentially splashing into the mucous membranes was in the range of 1 nL. CONCLUSION: For normal virus concentrations in the blood of sick patients, this dose is too small to cause hepatitis C and HIV.

Gain competition in dual wavelength quantum cascade lasers.

We investigated dual wavelength mid-infrared quantum cascade lasers based on heterogeneous cascades. We found that due to gain competition laser action tends to start in higher order lateral modes. The mid-infrared mode with the lower threshold current reduces population inversion for the second laser with the higher threshold current due to stimulated emission. We developed a rate equation model to quantitatively describe mode interactions due to mutual gain depletion.

Insulin leakage value in relation to pen needle length and administered dose after subcutaneous injection.

OBJECTIVE: During a subcutaneous injection with commonly used pen needles, the safety of drug administration plays an essential role. Today short needles with a length of 5.0 mm are increasingly being used. However, so far it is unresolved whether short needles of <5.0 mm affect the safety of insulin injections because of an increased backflow to the skin surface. We examined the influence of needle length and administered insulin dosage on the insulin backflow and the distribution of human insulin in the tissue by a quantitative determination of the amount of backflow of insulin to the skin surface. For the first time a new 4.5-mm pen needle was examined for its administration safety. RESEARCH DESIGN: Human insulin was radioactively marked. By means of an insulin pen different insulin dosages with pen needles of different lengths into fresh pork rind (ex vivo model) were administered. The amount of the marked insulin leaking from the tissues at the injection site was covered and absorbed immediately into a cotton swab. The amount of leakage was calculated by means of the radioactivity taken up by the swab. RESULTS: The amount of leakage for each measurement was less than 1% of the total dosage administered. The amount of leakage increased with increased dosage administered in absolute terms, but expressed as a percentage of the increased dosage administered the leakage decreased. CONCLUSION: The needle length (between 12 mm and 4.5 mm) did not have a meaningful influence on the amount of leakage; however, significant differences with different needle lengths could be observed.

Comparison of 4 different types of surgical gloves used for preventing blood contact.

BACKGROUND: Needlestick injuries are always associated with a risk of infection, because these types of punctures may expose healthcare workers to a patient's blood and/or body fluids. OBJECTIVE: To compare the efficacy of 4 different types of surgical gloves for preventing exposure to blood as a result of needlestick injury. METHODS: For simulation of needlestick injury, a circular sample of pork skin was tightened onto a bracket, and a single finger from a medical glove was stretched over the sample. First, a powder-free surgical glove with a gel coating was used to test blood contact. Second, a glove with a patented puncture indication system was used to test blood contact with a double-gloved hand. Third, 2 powder-free latex medical gloves of the same size and hand were combined for double gloving, again to test blood contact. Finally, we tested a glove with an integrated disinfectant on the inside. The punctures were carried out using diverse sharp surgical devices that were contaminated with (99)Tc-marked blood. The amount of blood contact was determined from the transmitted radioactivity. RESULTS: For the powder-free surgical glove with a gel coating, a mean volume of 0.048 microL of blood (standard error of the mean [SEM], 0.077 microL) was transferred in punctures with an automated lancet at a depth of 2.4 mm through 1 layer of latex. For the glove with an integrated disinfectant on the inside, the mean volume of blood transferred was 0.030 microL (SEM, 0.0056 microL) with a single glove and was 0.024 microL (SEM, 0.003 microL) with 2 gloves. For the glove with the patented puncture indication system, a mean volume of 0.024 microL (SEM, 0.003 microL) of blood was transferred. CONCLUSIONS: Double gloving or the use of a glove with disinfectant can result in a decrease in the volume of blood transferred. Therefore, the use of either of these gloving systems could help to minimize the risk of bloodborne infections for medical staff.

Study of blood contact in simulated surgical needlestick injuries with single or double latex gloving.

OBJECTIVE: Needlestick injuries are the most common injuries that occur among operation room personnel in the health care service. The risk of infection after a needlestick injury during surgery greatly depends on the quantity of pathogenic germs transferred at the point of injury. The aim of this study was to measure the quantity of blood transferred at the point of a percutaneous injury by using radioactively labeled blood. DESIGN: This study was conducted to evaluate the risk of infection through blood contact by simulating surgical needlestick injuries ex vivo. The tests were conducted by puncturing single and double latex gloves with diverse sharp devices and objects that were contaminated with Technetium solution-labeled blood. RESULTS: A mean volume of 0.064 microL of blood was transferred in punctures with the an automatic lancet at a depth of 2.4 mm through 1 layer of latex. When the double-gloving indicator technique was used, a mean volume of only 0.011 microL of blood was transferred (median, 0.007 microL); thus, by wearing 2 pairs of gloves, the transferred volume of blood was reduced by a factor of 5.8. CONCLUSIONS: The results revealed that double gloving leads to a significant reduction in the quantity of blood transferred during needlestick injury.

Room-temperature continuous-wave operation of an external-cavity quantum cascade laser.

Room-temperature, continuous-wave operation of an external-cavity quantum cascade laser (EC-QCL) is reported. Single-mode tuning range of 120 cm(-1) was achieved, from 7.96 to 8.84 microm. The gain chips utilized are based on the bound to continuum design and were fabricated as buried heterostructure lasers. Gap-free tuning (mode hops only on the external-cavity modes) is demonstrated for an antireflection-coated laser, just by grating rotation. The EC-QCL was implemented in a Littrow setup and an average power of 1.5 mW was obtained at 20 degrees C, while a peak power of 20 mW was obtained for a modified Littrow setup with the back extraction of light.