Length Of Exposure Time Research Articles

The Response of Rapeseed (Brassica napus L.) Seedlings to Silver and Gold Nanoparticles

With the advancement of nanotechnology and the increasing utilization of nanoparticles (NPs), their production and release into the environment are on the rise. Consequently, it is crucial to continuously monitor the toxicity of nanoparticles for humans, animals, and plants, as well as their impact on the environment. This is particularly significant in relation to human health and food production, given the escalating use of nanomaterials in agriculture and horticulture. The aim of the study was to investigate the response of rapeseed seedlings to silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) over different periods of exposure. This research analyzed the impact of these nanoparticles on the biochemical response of rapeseed seedlings after 7, 14, and 21 days of growth in their presence. This study assessed the activity of guaiacol peroxidase (GPOX), pyrogallol peroxidase (PPOX), superoxide dismutase (SOD), and free protein content, as well as the interactions between key elements responsible for oxidative stress and the antioxidant response. The findings demonstrated a significant effect of AgNPs and AuNPs on stimulating the response of rapeseed seedlings, with the activity of PPOX, GPOX, and SOD being dependent on the exposure time and the type and dose of nanoparticles used. Enzyme activity increased with the length of exposure time, while the content of free protein decreased over the weeks. The most intense reaction of seedlings was observed in the case of GPOX, with the lowest activity observed in PPOX and SOD. High effects of the nanoparticle type and rate were also observed in the correlation matrix. This study suggests that a comprehensive analysis of plant reactions to nanoparticles could have a significant impact on the proper and effective use of nanoparticles in agriculture and horticulture. This could lead to the environmentally friendly production of high-quality plant material.

Optimizing the post-harvest salting of cultured oysters (Crassostrea virginica) using a recirculating wet storage system by monitoring adductor hemolymph osmolality

The oyster aquaculture industry is steadily growing in the United States, principally driven by the rise of small farms. With an increasingly crowded marketplace, farmers are searching for methods to diversify their crops and remain competitive. Enhancing oyster liquor in wet storage while preserving the water's signature flavor, or ‘merroir,’ is one way to create a new product line and differentiate crops, especially with oysters grown in low-salinity environments. Previously, growers have attempted to increase the salinity of their product by ‘finishing’ their oysters in a saltier water body; however, mass mortality may accompany such a transfer. Therefore, implementing a wet storage system may be a useful intermediary step to reduce crop mortality prior to ‘finishing’ oysters in alternative waters. This project sought to understand how to effectively use recirculating aquaculture systems (RAS) as wet storage to expose harvested oysters to a chosen salinity and temperature to function as a modified wet storage system. Additionally, this experiment describes the effects of both short-term and long-term salinity and temperature stress on the survival, condition index, and shelf life of adult oysters. The shelf life and rate of osmoconformity of low-salinity adult oysters depend on ambient temperature and acute changes in salinity. While increasing ambient temperature improves the rate of hemolymph osmoconformity, we observed high mortality above 25 °C. Additionally, the shelf life of oysters was negatively affected by the length of exposure time to higher salinity and increasing temperature. These data can guide oyster growers in low-salinity regions who wish to diversify their product using recirculating tanks or better understand the potential risks associated with transferring cultured oysters across water bodies of varying salinity.

Effect of different hypoxic and hypobaric interventions on blood gas and erythrocyte-related indicators in rats.

To explore the effects of hypoxic and hypobaric conditions on blood gas and erythrocyte-related indicators in rats. SD male rats were exposed to low-pressure hypoxic conditions simulating an altitude of 6500 m in a small or a large experimental cabin. Abdominal aortic blood samples were collected and blood gas indicators, red blood cells (RBCs) count, and hemoglobin (Hb) content were measured. The effects of exposure to different hypoxia times, different hypoxia modes, normal oxygen recovery after hypoxia, and re-hypoxia after hypoxia preconditioning on blood gas indicators, RBCs count and Hb content were investigated. The effect of blood gas indicators was correlated with the length of exposure time of hypoxia and the reoxygenation after leaving the cabin. Hypoxia caused acid-base imbalance and its severity was associated with the duration of hypoxia; hypoxia also led to an increase in RBCs count and Hb content, and the increase was also related to the time exposed to hypoxia. The effects of reoxygenation on acid-base imbalance in rats caged in a small animal cabin were more severe that those in a large experimental cabin. Acetazolamide alleviated the effects of reoxygenation after leaving the cabin. Different hypoxia modes and administration of acetazolamide had little effect on RBCs count and Hb content. Normal oxygen recovery can alleviate the reoxygenation and acid-base imbalance of hypoxic rats after leaving the cabin and improve the increase in red blood cell and hemoglobin content caused by hypoxia. The improvement of hypoxia preconditioning on post hypoxia reoxygenation is not significant, but it can alleviate the acid-base imbalance caused by hypoxia in rats and to some extent improve the increase in red blood cell and hemoglobin content caused by hypoxia. Due to excessive ventilation and elevated RBCs count and Hb content after hypoxia reoxygenation, oxygen partial pressure and other oxygenation indicators in hypoxic rats are prone to become abnormal, while blood gas acid-base balance indicators are relatively stable, which are more suitable for evaluating the degree of hypoxia injury and related pharmacological effects in rats.

EVALUATION OF THE EFFECTIVENESS OF VARIOUS DISINFECTANTS, INCLUDING TRADITIONAL AND MODIFIED NANO TYPES, AGAINSTBRUCELLA MELITENSIS

The zoonotic illness brucellosis may spread between humans and animals in a variety of ways. The prevention and management of brucellosis depend heavily on the cleanliness of the areas around animals and the effective eradication of infection from animal housing. In our investigation, we tested a variety of disinfectants against Brucella melitensis to see how well they worked and whether they would work in various environmental settings. In addition to three different types of nano-disinfectants (Dettol with Silver-NPs, Glutaraldehyde with Silver-NPs, and Calcium oxide-NPs), our study included various conventional forms of disinfectants and antiseptics (Virkon[Formula: see text] S, Cidex, Sodium hypochlorite, Betadine, and Dettol). For estimating the effectiveness of various types of applied disinfectants, reduction rate was employed. The findings indicated that the concentration and length of exposure time of the disinfectants employed, particularly Vircon S, had an impact on their ability to kill bacteria. However, the presence of filthy circumstances and low temperatures considerably reduced the effectiveness of disinfectants, particularly Dettol. On the other hand, nano-disinfectants, particularly glutaraldehyde containing silver nanoparticles, showed better effects than conventional ones. Our research indicated that disinfectants used in everyday life had an impact on Brucella melitensis. However, the presence of filthy environments and low temperatures reduced the bactericidal effectiveness. The impact of nano-disinfectants on Brucella was better.

Effects of Electromagnetic Radiation on Neuropeptide Transcript Levels in the Synganglion of Ixodes ricinus.

Anthropogenic electromagnetic radiation is an important environmental factor affecting the functionality of biological systems. Sensitivity to various frequencies of electromagnetic radiation has been detected in ixodid ticks in the past. However, the physiological aspects of radiation effects have not yet been studied in ticks. In the presented experiment, 360 Ixodes ricinus ticks, 180 males and 180 females, were divided into 16 irradiated and 8 control groups. The irradiated groups were exposed to two different intensities of electromagnetic radiation with a frequency of 900 MHz at different lengths of exposure time. RT-PCR was utilized to determine the changes in mRNA levels in tick synganglia after irradiation. Four randomly selected neuropeptide genes were tested-allatotropin (at), FGLa-related allatostatins (fgla/ast), kinin, and arginine-vasopressin-like peptide (avpl). A significant decrease in transcript levels in all female groups exposed to higher intensity radiofrequency radiation for 1 to 3 h was found. After one hour of radiofrequency exposure, a significant downregulation in allatotropin expression in males was detected. A consistent downregulation of the at gene was detected in males irradiated with at a higher intensity. Unfortunately, the specific functions of the studied neuropeptides in ticks are not known yet, so a more comprehensive study is necessary to describe the effects of EMF on observed neuropeptides. This study represents the first report on the effects of the abiotic environment on tick neurophysiology.

Effects of heatwave events on the seagrass-dwelling crustacean Pandalus latirostris in a subarctic lagoon

Heatwaves often cause mass mortality of organisms in seagrass areas, and they eventually alter some ecological functions of seagrass ecosystems. In subarctic regions, however, the effects of heatwaves on seagrass areas are still unclear. In a subarctic lagoon of northern Japan, we examined the effects of heatwaves on the Hokkai shrimp, Pandalus latirostris, a commercially exploited species distributed in seagrass areas of northern Japan and eastern Russia. A long-term survey of the surface water temperature in the lagoon clarified a gradual increase in the frequency and intensity of heatwave events since 1999. Surveys of the water temperature at a seagrass area in the lagoon during summer have also demonstrated that the maximum water temperature had been exceeding 25 °C, unusually high for this location, regardless of water depth. These results indicate that the effects of heatwaves in seagrass areas in a subarctic region had become as severe as those in tropical and temperate regions. We also experimentally evaluated the effects of this unusually high water temperature (25 °C) on the survival of P. latirostris by changing the length of exposure time. Some individuals suffered damage to their intestinal mucosal structure after exposure for 12 h or longer, and all individuals died after exposure for 120 h. Our results suggest that heatwaves possibly cause mass mortality in P. latirostris in the following sequence: heat stress, damage to the intestinal epithelial mucosal structure, degradation of nutrient absorption and immunological function of the intestine, energy deficiency and disease infection, and finally mortality. This study, conducted in subarctic closed waters, concludes that it is essential to become familiar with not only trends in heatwaves but also the intermittent occurrence of unusually high water temperature in seagrass areas in order to better understand the process of mortality of organisms that inhabit these ecosystems.

Molluscicidal activity of Nicotiana tabacum extracts on the invasive snail Pomacea canaliculata

Botanical molluscicides for controlling the invasive snail Pomacea canaliculata have attracted worldwide attention because of their cost and environmental friendliness. Aqueous extracts from discarded tobacco leaf (Nicotiana tobacum) were evaluated for molluscicidal activity against different-sized P. canaliculata under laboratory conditions. The results showed that over 90% of the snails died in 1 g/L tobacco extract within 4 days, and the survival of P. canaliculata was inversely proportional to the snail size, tobacco extract concentration and length of exposure time. Adult males were more susceptible to tobacco extract than females. The snails had few chances to feed or mate in 0.5 g/L tobacco extract, and reproduction was greatly limited in 0.2 g/L. The growth of juvenile snails was inhibited in 0.2 g/L tobacco extract, but adults were unaffected. The antioxidant capacity of P. canaliculata in response to tobacco extract can be size- and sex-dependent, and the activities of superoxide dismutase, catalase, and acetylcholinesterase and the contents of glutathione and malondialdehyde were increased in adult males. These results suggest that discarded tobacco leaves can be useful as a molluscicide for controlling the invasive snail P. canaliculata based on its effects on survival, behaviour, food intake, growth performance and antioxidant capacity.

On strategies to help reduce contamination on public transit: a multilayer network approach

In times of a global pandemic, public transit can be crucial to spreading viruses, especially in big cities. Many works have shown that the human infection risk could be extremely high due to the length of exposure time, transmission routes, and structural characteristics during public transportation, and this can result in the rapid spread of the infection. Vaccines are often part of strategies to reduce contagion; however, they can be scarce in pandemic settings. Considering real-world and large-scale traffic data, this work proposes using time-varying multilayer networks to identify the main critical places to be prioritized in interventions, such as vaccination campaigns, to help reduce contagion on public transit. We exemplify our strategy in different vaccination scenarios. First, when considering only critical bus stops as priority vaccination points, determined by our approach, we indicate that focusing on vaccination in these locations reduces the spread of infection using fewer doses than a random vaccination. In another experiment, we demonstrate the flexibility of our approach in identifying other critical points of interest, healthcare units in this case. Vaccination in these vital health units could also be a viable strategy to curb contagion using a predetermined number of doses. The approach proposed in this study is not limited to vaccination strategies. It also applies to other problems that share similar properties, even in several different contexts, such as optimization in public transit or exploring different points of interest to gather insights from other issues of interest.

Glutamate-Evoked Ca2+ Responses in the Rat Suprachiasmatic Nucleus: Involvement of Na+/K+-ATPase and Na+/Ca2+-Exchanger.

Glutamate mediates photic entrainment of the central clock in the suprachiasmatic nucleus (SCN) by evoking intracellular Ca2+ signaling mechanisms. However, the detailed mechanisms of glutamate-evoked Ca2+ signals are not entirely clear. Here, we used a ratiometric Ca2+ and Na+ imaging technique to investigate glutamate-evoked Ca2+ responses. The comparison of Ca2+ responses to glutamate (100 μM) and high (20 mM) K+ solution indicated slower Ca2+ clearance, along with rebound Ca2+ suppression for glutamate-evoked Ca2+ transients. Increasing the length of exposure time in glutamate, but not in 20 mM K+, slowed Ca2+ clearance and increased rebound Ca2+ suppression, a result correlated with glutamate-induced Na+ loads. The rebound Ca2+ suppression was abolished by ouabain, monensin, Na+-free solution, or nimodipine, suggesting an origin of activated Na+/K+-ATPase (NKA) by glutamate-induced Na+ loads. Ouabain or Na+-free solution also slowed Ca2+ clearance, apparently by retarding Na+/Ca2+-exchanger (NCX)-mediated Ca2+ extrusion. Together, our results indicated the involvement of glutamate-induced Na+ loads, NKA, and NCX in shaping the Ca2+ response to glutamate. Nevertheless, in the absence of external Na+ (NMDG substituted), Ca2+ clearance was still slower for the Ca2+ response to glutamate than for 20 mM K+, suggesting participation of additional Ca2+ handlers to the slower Ca2+ clearance under this condition.

Analysis of Noise Levels in the Engine Room & St. Kernel Using the National Institute for Occupational Safety and Health (NIOSH) Method in PT. Karya Tanah Subur

Industry in Indonesia began to show progress and improvement marked by the use of sophisticated machines, almost all production processes in the industry caused noise. Noise can cause damage to hearing devices and cause psychological, physiological disorders that have the potential to cause disruption to work so as to reduce work productivity. PT. Karya Tanah Subur (KTS) is a company engaged in the business of plantation and processing of palm oil, the products produced in the form of crude palm oil (CPO) and kernels. The purpose of this study was to measure the level of noise that occurred in several PT operator rooms. The work of Fertile Land (KTS) which is directly adjacent to the machines that make noise. Then conduct a maximum time analysis of workers exposed to the noise generated based on the NIOSH calculation method. Selected noise sampling is the Engine Room Station (Turbine, Genset) and Kernel Station using the Sound level meter tool. From the results of this study, it shows that both points exceed the Threshold Value (NAB). The longest exposure time is at point 2 with a length of exposure time of 9 hours, while the shortest exposure time is at point 1 with a length of exposure time of 1.2 hours per day. In locations that have a risky noise intensity level, you should use earplugs/earmuffs to minimize the level of noise intensity and other supporting PPE for worker health and safety.

Pharmaceutical Sorption to Lab Materials May Overestimate Rates of Removal in Lab-Scale Bioreactors.

Environmental contamination from pharmaceuticals has received increased attention from researchers in the past 20 years. As such, numerous lab-scale studies have sought to characterize the effects of these contaminants on various targets, as well as determine improved removal methods. Many studies have used lab-scale bioreactors to investigate pharmaceutical effects on wastewater bacteria, as wastewater treatment plants often act as reservoirs for pharmaceuticals. However, few-if any-of these studies report the specific lab materials used during testing, such as tubing or pipette tip type. In this study, the pharmaceuticals erythromycin, diclofenac, and gemfibrozil were exposed to different micropipette tips, syringe filters, and tubing types, and losses over time were evaluated. Losses to tubing and syringe filters were particularly significant and neared 100%, depending on the pharmaceutical compound and length of exposure time. Results discussed herein indicate that pharmaceutical sorption to various lab supplies results in decreases to both dosed and quantified pharmaceutical concentrations. Studies that fail to consider this source of loss may therefore draw inaccurate conclusions about pharmaceutical effects or removal efficiencies.

Food quality and exposure time affect induced defences in Daphnia: Based on key morphology, life history traits, and expression of related genes

Abstract Kairomone‐induced anti‐predation defences in zooplankton mediate trophic interactions in aquatic ecosystems. Changes in food quality greatly affect induced defences because of the potential influence on resource allocation. Understanding how zooplankton respond to predation risk under poor nutrition conditions is critical for predicting ecosystem function. The present study focused on the fish kairomone‐induced defences in Daphnia pulex fed unicellular non‐toxic Microcystis aeruginosa. Transcriptions of key genes were detected to interpret changes in morphological and life history traits. Additionally, the degree of responsiveness of traits to increasing proportions of M. aeruginosa in the diet was compared at different endpoints with varied exposure duration. Daphnia pulex decreased body size but showed an elongated tail spine as morphological adaptations to the presence of fish kairomones, supported by enhanced transcriptions of chitin deacetylase and cuticle protein genes. However, with suppressed expression of the related genes, tail spine length was linearly reduced by increasing proportions of M. aeruginosa in the diet, accompanied by decreased somatic growth and reproduction. Presence of fish kairomones interactively affected the inhibitive effects of increasing proportions of M. aeruginosa in the diet on Daphnia growth, reproduction, and tail spine defence but not body size. In addition, the magnitude of effects of M. aeruginosa on Daphnia growth and morphological responses under fish kairomone exposure was increased with the increasing length of exposure time from 3–7 days (reaching maturity) to 14 days (by the end of tests), indicating an aggravated inhibitive effect of M. aeruginosa on induced defences over time. The present study provides references for evaluating zooplankton‐fish interactions under poor nutrition conditions. Since a cyanobacterial bloom may last from a few weeks to several months, experiments involving the whole life span of zooplankton are thought to fully reveal the actual impact of cyanobacteria on interspecific interactions related to zooplankton. In addition, unifying the exposure time to cyanobacteria for comparative studies is recommended in future research.

Phytoestrogens: A Review of Their Impacts on Reproductive Physiology and Other Effects upon Grazing Livestock.

Simple SummaryPhytoestrogens are secondary plant metabolites that play a role in plant defense, and when ingested by livestock have numerous functions related to reproduction, metabolism, immunological functions and livestock growth and performance. Phytoestrogens are found across various plant species, with the most biologically active of these, isoflavones and coumestans, abundant in legume species. Understanding the overall potential health and reproductive effects that may occur in livestock grazing phytoestrogenic pastures is essential to mitigate any potential risks attributed to fertility loss or to introduce proactive management strategies to aid in improving growth and development. A review of their interactions with livestock systems will provide updated information for the agricultural and veterinary industries.Legume crops and pastures have a high economic value in Australia. However, legume species commonly used for grazing enterprises have been identified to produce high concentrations of phytoestrogens. These compounds are heterocyclic phenolic, and are similar in structure to the mammalian estrogen, 17β-estradiol. The biological activity of the various phytoestrogen types; isoflavones, lignans and coumestans, are species-specific, although at concentrations of 25 mg/kg of dry matter each of the phytoestrogen types affect reproductive functions in grazing livestock. The impacts upon fertility in grazing livestock such as cattle and sheep, vary greatly over length of exposure time, age and health of animal and the stress stimuli the plant is exposed to. More recently, research into the other effects that phytoestrogens may have upon metabolism, immune capacity and growth and performance of grazing livestock has been conducted. Potential new benefits for using these phytoestrogens, such as daidzein and genistein, have been identified by observing the stimulation of production in lymphocytes and other antibody cells. Numerous isoflavones have also been recognized to promote protein synthesis, increase the lean meat ratio, and increase weight gain in cattle and sheep. In Australia, the high economic value of legumes as pasture crops in sheep and cattle production enterprises requires proactive management strategies to mitigate risk associated with potential loss of fertility associated with inclusion of pasture legumes as forages for grazing livestock.

Mantle and Its Protective Role of the Slipper-shaped Oyster (Crassostrea Iredalei) in Response to Crude Oil

The mantle plays important role in the mechanism of oyster protection caused by environmental pollutants. This study aims to analyze the effect of water accommodated fraction of crude oil on the mantle of Slipper-Shaped Oyster (Crassostrea iredalei) at different doses and time exposure. The ventral and posterior segments of the mantle were fixed, and tissue sections were stained with hematoxylin-eosin, PAS-Periodic acid–Schiff, and TEM-transmission electron microscopy techniques. HE-hematoxylin and eosin, PAS-alcian, and TEM-transmission electron microscopy were used to characterize the different mucosubstances and to describe the ultrastructure-related response on a certain part of the mantle after exposure. The tissues of epithelium, connective tissue, mucus cells, pigmented cells, numerous hemolymph sinuses, shell formation, and blood sinus were recognized under a light microscope. The mucous cell was excreted in all the concentrations (control, 12.5, 25, 50, and 100% Water Acomodate Fraction) and also in the time exposure (24, 48, 72, and 96 hours). A large number of mucous cells was produced in the inner mantle cavity (IMC) and outer mantle cavity (OMC). Mucous cells increased in number with increasing WAF concentration as well as the length of exposure time. The highest number of mucus cells was observed at 100% Water Accommodate Fraction (WAF) concentration and 96 hours of exposure. The structure and function of the mantle, the shell formation, the edge of the mantle, mucous cell, muscle bundles, nerve fibers, and epithelium layer of the Slipper-Shaped Oyster (Crassostrea iredalei) were documented in this study.

FITOREMEDIASI MENGGUNAKAN KAYU APU (Pistia stratiotes) UNTUK MENURUNKAN KADAR COD LIMBAH CAIR TEKSTIL

Waste water treatment is needed to avoid the impact of pollution to the aquatic environment. Techniques for treating waste water, among others, are through phytoremediation using the help of water lettuce (Pistia stratiotes).This research aims to determine the effect of the percent covering area of water lettuce, the length of exposure time, and interaction of both in reducing levels COD, and to determine the percent of covering area, the length of exposure time, and interaction of both that is the most efficient in reducing The result of this research showed that the percent covering area, and the length of exposure time  had a very significant effect of decreasing levels of COD. The most efficient percent covering area in reducing COD was in treatment of 75%. The most efficient length of exposure time in reducing COD was in treatment 9 days.  The most efficient interaction of both in reducing COD levels was at treatment of 100% coverage area with exposure time of 9 days.

Corrosion Behavior of Low Carbon Steel Pipe in Condensate Environment

Low carbon steel pipe is widely used in various pipeline applications because it has good mechanical properties. The application of low carbon steel developed generally does not involve corrosion resistance. To find out the behavior of low carbon steel pipe in condensate fluids, the immersion test was carried out. The method for the immersion test is the planned-interval test. The corrosion rate of this steel was determined by weight loss, whereas the corrosivity of the condensate fluids was measured by a multimeter Hach HQ40d. The morphology of corrosion products is characterized by using scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), and x-ray diffraction (XRD). The result of immersion of low carbon steel pipe in the condensate fluids shows that the liquid corrosivity and corrodibility of low carbon steel pipe tend to decreases with the length of exposure time. The decrease of metal corrodibility is identical to the lower corrosion rate at a longer exposure time due to the layer a corrosion product formed. The corrosion products during immersion tests are uniform with iron oxide in the form of FeO(OH) and Fe2O3.H2O.
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Are women always better able to recognize faces? The unveiling role of exposure time.

A longer exposure time generally improves individuals’ ability to recognize faces. The current research investigates whether this effect varies between genders and whether it is influenced by the gender of the exposed faces. Based on a set of four experimental studies, we advance our knowledge of face recognition, gender, gender distribution of exposed faces, and exposure time in three main ways. First, the results reveal that women are more likely than men to suffer from a decrease in face recognition ability due to a lower exposure time. Second, the findings show that when exposure time is short (vs. long) women recognize a larger proportion of same gender faces and also recognize a larger proportion of same gender faces as compared with the proportion of same gender faces recognized by men. Third, findings reveal that when individuals are only exposed to same gender faces, women recognize more faces than men regardless whether exposure time is short, or long. In short, the findings of this research suggest that insight into the interplay between gender and exposure time length is critical to appropriately determine human beings’ ability to recognize faces.

Ultraviolet light accelerates the degradation of polyethylene plastics.

Polyethylene plastics are widely used in daily life in the packaging of foodstuffs, pharmaceuticals, cosmetics, detergents, and chemicals. In this study, low-density polyethylene (LDPE) was exposed to an ultraviolet (UV) fluorescence lamp in simulated aging and degradation experiments. Ultraviolet degradation mechanisms were investigated on the surface after sunlight and UV lamp exposure. The plastic surfaces' molecular and surface degradation results were compared with their Fourier Transform Infrared-Attenuated Total Reflectance (FTIR-ATR) and ultraviolet visible (UV-Vis) spectra. By growing the length of exposure time increased stages of degradation were observed. After UV lamp and sunlight exposure, changing degradation levels were also determined with spectroscopic evaluations and the results were compared. LDPE was selected since it has a simple structure and a number of branched polymer structures that facilitate easily disruption of the chemical bond. Breaks in the polymer chain were easily seen in the plastics at the end of degradation and a fragile structure was formed throughout the polymer chain after accelerating UV light aging. The FTIR spectrum clarified the changed and fractured molecular bond structures of UV-exposed polyethylene. The change in the molecular structure of the plastic caused small changes in its color and small variations in this color change were detected by recording the Ultraviolet-Visible (UV-Vis) spectrum. The Philips UV lamp's light intensity and the wavelength spectrum range were measured. The UV lamp and sun UV light doses were calculated and compared.

Utilizing DPPC Liposomes to Capture Persistent Organic Pollutants

Polychlorinated biphenyls (PCBs) are a class of man-made persistent organic pollutants that saw wide-spread use in commercial and industrial infrastructure as both an insulator and coolant in electrical transformers and capacitors. 2,2’,3,3′,4,4’-hexachlorobiphenyl (HCBP) was one of the most widely produced PCBs. As these mechanical structures failed or are discarded, PCBs are released into the soil, migrate to the water table, and eventually spread to nearby ecosystems by rain and wind. The remarkable chemical stability of PCBs leave few options for environmental waste and water removal, yet they are becoming increasingly concerning as they pose potential health risks to individuals who become exposed to them. Conventionally, liposomes have been used for their promising drug delivery capabilities. Here, we investigated their potential for the entrapment and removal of HCBP. Liposomes are small, nonpolar lipid bi-layered aggregates capable of capturing a wide variety of both polar and nonpolar compounds. Dipalmitoylphosphatidylcholine (DPPC) is a well-characterized lipid that can be derived from natural sources. It is a phospholipid typically found as a major component of pulmonary surfactant mixtures. To assess the utility of liposomes prepared with pure DPPC in capturing PCBs, they were prepared using probe-tip sonication for both direct and passive incorporation of HCBP. Incorporation was assessed using a combination of differential scanning calorimetry and UV-Vis spectroscopy. For direct incorporation liposome stability generally decreased compared to pure DPPC liposomes based on a corresponding decrease in the phase transition temperature, Tm, from 40.8 °C to 37.4 °C. An analysis of passive incorporation using UV-Vis spectroscopy showed an increase in the incorporation of HCBP proportionate to the length of exposure time up to 24 hours. Together our calorimetry and spectroscopic measurements are indicative of HCBP incorporation into liposomes and shows promising potential for use in sustainable environmental cleanup and water treatment technologies. Future studies aim to further explore their technological capabilities by optimizing their thermal and mechanical stability.

Investigating DPPC Liposomes and Their Capacity to Assimilate 2,2’,3,3’,4,4’-Hexachlorobiphenyl, an Emerging Environmental Pollutant

Persistent organic pollutants (POPs) are organic compounds that bioaccumulate in a wide variety of biological and ecological environments due to their resistive nature to chemical, thermal and photodegradation. The stability of POPs and specifically PCBs (a subclass of POPs) leave few options for environmental waste and water removal. Conventionally, liposomes have been used for their drug delivery capabilities, but here we investigated their potential for the entrapment and removal of this class of emerging environmental pollutants. Liposomes are small, nonpolar lipid bi-layered aggregates capable of capturing a wide variety of both polar and nonpolar compounds. Dipalmitoylphosphatidylcholine (DPPC)is a well-characterized lipid that can be derived from natural sources. It is a phospholipid typically found as a major component of pulmonary surfactant mixtures. To assess the utility of liposomes prepared with pure DPPC in capturing PCBs, they were prepared using probe-tip sonication for both direct and passive incorporation of a representative PCB compound, 2,2’,3,3’,4,4’-hexachlorobiphenyl (HCBP). Incorporation of HCBP was assessed using a combination of differential scanning calorimetry and UV-Vis spectroscopy. For direct incorporation in the presence of HCBP, it was apparent that liposome stability generally decreased compared to pure DPPC liposomes based on a corresponding decrease in the phase transition temperature, Tm, from 40.8 °C to 37.4 °C. Additionally, an analysis of passive incorporation by UV-Vis spectroscopy showed an increase in the incorporation of HCBP proportionate to the length of exposure time up to 24 hours. Both the decrease in Tm and substantial UV absorbance signal produced after the compound was extracted from DPPC liposomes are indicative of its incorporation and demonstrates the potential for the use of liposomes in sustainable environmental cleanup and water treatment technologies.