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The Science of the Total Environment Sep 2023Green infrastructure drainage systems are innovative treatment units that capture and treat stormwater. Unfortunately, highly polar contaminants remain challenging to...
Green infrastructure drainage systems are innovative treatment units that capture and treat stormwater. Unfortunately, highly polar contaminants remain challenging to remove in conventional biofilters. To overcome treatment limitations, we assessed the transport and removal of stormwater vehicle-related organic contaminants with persistent, mobile, and toxic (in short: PMTs) properties, such as 1H-benzotriazole, NN'-diphenylguanidine, and hexamethoxymethylmelamine (PMT precursor), using batch experiments and continuous-flow sand columns amended with pyrogenic carbonaceous materials, like granulated activated carbon (GAC) or wheat-straw derived biochar. Our results indicated that all investigated contaminants were subjected to nonequilibrium interactions in sand-only and geomedia-amended columns, with kinetic effects upon transport. Experimental breakthrough curves could be well described by a one-site kinetic transport model assuming saturation of sorption sites, which we inferred could occur due to dissolved organic matter fouling. Furthermore, from both batch and column experiments, we found that GAC could remove contaminants significantly better than biochar with higher sorption capacity and faster sorption kinetics. Hexamethoxymethylmelamine, with the lowest organic carbon-water partition coefficient (K) and largest molecular volume among target chemicals, exhibited the lowest affinity in both carbonaceous adsorbents based on estimated sorption parameters. Results suggest that sorption of investigated PMTs was likely driven by steric and hydrophobic effects, and coulombic and other weak intermolecular forces (e.g., London-van der Waals, H-bonding). Results from extrapolating our data to a 1-m depth geomedia-amended sand filter suggested that GAC and biochar could enhance the removal of organic contaminants in biofilters and last for more than one decade. Overall, our work is the first to study treatment alternatives for NN'-diphenylguanidine and hexamethoxymethylmelamine, and contributes to better PMT contaminant removal strategies in environmental applications.
Topics: Charcoal; Guanidines; Adsorption
PubMed: 37209730
DOI: 10.1016/j.scitotenv.2023.164264 -
Environmental Science & Technology Dec 2023The occurrence of continuously released polycyclic aromatic hydrocarbons (PAHs) in marginal seas is regulated by hydrological and biogeochemical processes; however,...
The occurrence of continuously released polycyclic aromatic hydrocarbons (PAHs) in marginal seas is regulated by hydrological and biogeochemical processes; however, scarce knowledge is about their derivatives in marine environments. In this study, the dissolved and particulate PAHs and their alkylated/nitrated derivatives (A-PAHs/N-PAHs) in surface seawater of the southwestern Yellow Sea (YS) and northwestern East China Sea (ECS) during September 2022 were comprehensively discussed. Results confirm higher levels of ΣPAHs (9.3-70 ng/L) and ΣA-PAHs (13-76 ng/L) than ΣN-PAHs (0.80-6.6 ng/L). The spatial heterogeneity of contaminants was regulated by substantial riverine runoff and ocean currents. Lagrangian Coherent Structure analysis further revealed the existence of a transport barrier at the shelf break of the southwestern YS where contaminants hardly crossed and tended to accumulate. The relationship between dissolved compounds and chlorophyll indicated both biodegradation and the biological pump contributed to the depletion of PAHs and A-PAHs from surface seawater while the biological pump was the major driver for N-PAHs, despite their complicated water-particle partition behavior due to variations in physicochemical properties in the presence of nitro groups. Source identification demonstrated that pyrogenic and petrogenic sources dominated the YS and ECS, respectively, while photochemical transformations appeared more active in the YS.
Topics: Water Pollutants, Chemical; Nitrates; Polycyclic Aromatic Hydrocarbons; Chlorophyll A; Environmental Monitoring; Oceans and Seas; China; Membrane Transport Proteins
PubMed: 37867381
DOI: 10.1021/acs.est.3c07476 -
Nature Ecology & Evolution Dec 2023Remote islands in the Pacific Ocean (Oceania) experienced dramatic environmental transformations after initial human settlement in the past 3,000 yr. Here, human...
Remote islands in the Pacific Ocean (Oceania) experienced dramatic environmental transformations after initial human settlement in the past 3,000 yr. Here, human causality of this environmental degradation has been unquestioned and viewed as evidence of the inherent destructive tendencies of human societies in both archaeological and popular discourse. We use charcoal and stable carbon isotopes from deep soil cores to reconstruct the dynamics of fire activity and deforestation across the Sigatoka River valley on the leeward (dry) side of Viti Levu, Fiji. Fires and pyrogenic patches of grassland predated human settlement by millennia, but the magnitude of fire activity and landscape transformation accelerated with the establishment and expansion of swidden agriculture. Regional comparisons with previous studies in Fiji and elsewhere in Remote Oceania settled between 3,200 and 2,900 yr BP reveal a similar pattern of pre- and post-settlement fire activity and landscape change. Pre-settlement fires generally corresponded to droughts, probably driven by El Niño, often correlating with drought-driven wildfires elsewhere in the region. Post-settlement, charcoal and C grasses increased dramatically, but nearly all major peaks in charcoal and grasses corresponded to increased El Niño activity. This indicates that fire activity and deforestation were a product of the interaction between swidden agriculture and climate rather than land use alone.
Topics: Humans; Ecosystem; Conservation of Natural Resources; Charcoal; Fires; Climate
PubMed: 37783826
DOI: 10.1038/s41559-023-02212-8 -
Environmental Science and Ecotechnology Mar 2024Contaminants, such as polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), heavy metals, and per and polyfluoroalkyl substances (PFASs), primarily...
Contaminants, such as polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), heavy metals, and per and polyfluoroalkyl substances (PFASs), primarily reach the Arctic through long-range atmospheric and oceanic transport. However, local sources within the Arctic also contribute to the levels observed in the environment, including legacy sources and new sources that arise from activities associated with increasing commercial and industrial development. The City of Iqaluit in Frobisher Bay, Nunavut (Canada), has seen rapid population growth and associated development during recent decades yet remains a site of interest for ocean protection, where Inuit continue to harvest country food. In the present study, seven dated marine sediment cores collected in Koojesse Inlet near Iqaluit, and from sites in inner and outer Frobisher Bay, respectively, were analyzed for total mercury (THg), major and trace elements, PAHs, PCBs, and PFASs. The sedimentary record in Koojesse Inlet shows a period of Aroclor 1260-like PCB input concurrent with military site presence in the 1950-60s, followed by decades of input of pyrogenic PAHs, averaging about ten times background levels. Near-surface sediments in Koojesse Inlet also show evidence of transient local-source inputs of THg and PFASs, and recycling or continued slow release of PCBs from legacy land-based sources. Differences in PFAS congener composition clearly distinguish the local sources from long-range transport. Outside Koojesse Inlet but still in inner Frobisher Bay, 9.2 km from Iqaluit, sediments showed evidence of both local source (PCB) and long-range transport. In outer Frobisher Bay, an up-core increase in THg and PFASs in sediments may be explained by ongoing inputs of these contaminants from long-range transport. The context for ocean protection and country food harvesting in this region of the Arctic clearly involves both local sources and long-range transport, with past human activities leaving a long legacy insofar as levels of persistent organic pollutants are concerned.
PubMed: 37860827
DOI: 10.1016/j.ese.2023.100313 -
Archives of Microbiology Dec 2023Vibrio parahaemolyticus is a significant cause of seafood-associated gastroenteritis and pestilence in aquaculture worldwide. Despite extensive research, strategies for...
Vibrio parahaemolyticus is a significant cause of seafood-associated gastroenteritis and pestilence in aquaculture worldwide. Despite extensive research, strategies for protein depletion in this pathogen remain limited. Herein, we constructed a new CRISPR interference (CRISPRi) system for gene repression based on the combination of a shuttle vector pVv3 and the nuclease-null Cas9 variant (dead Cas9, or dCas9) from Streptococcus pyrogens. This CRISPRi is induced by adding both IPTG and arabinose. We showed that gene repression is scalable via the use of multiple sgRNAs. We also demonstrated that this gene repression can be precisely tuned by adjusting the amount of two different inducers and can be reversed by removing the inducers. This system provides a simple approach for selective gene repression on a genome-wide scale in V. parahaemolyticus. Application of this system will dramatically accelerate investigations of this bacterium, including studies of physiology, pathogenesis, and drug target discovery.
Topics: Vibrio parahaemolyticus; RNA, Guide, CRISPR-Cas Systems; Aquaculture; Arabinose; Drug Discovery
PubMed: 38147133
DOI: 10.1007/s00203-023-03770-y -
Microbial Genomics Dec 2023The standalone regulator RofA is a positive regulator of the pilus locus in . Found in only certain genotypes, RofA has been reported to regulate other virulence...
The standalone regulator RofA is a positive regulator of the pilus locus in . Found in only certain genotypes, RofA has been reported to regulate other virulence factors, although its role in the globally dominant 1 is unclear. Given the recent emergence of a new 1 (M1) toxigenic lineage that is distinguished by three non-synonymous SNPs in , we characterized the regulon in six 1 strains that are representative of the two contemporary major 1 lineages (M1 and M1) using RNAseq analysis, and then determined the specific role of the M1-specific SNPs. Deletion of in three M1 strains led to altered expression of 14 genes, including six non-pilus locus genes. In M1 strains, deletion of led to altered expression of 16 genes, including nine genes that were unique to M1. Only the pilus locus genes were common to the RofA regulons of both lineages, while transcriptomic changes varied between strains even within the same lineage. Although introduction of the three SNPs into did not impact gene expression in an M1 strain, reversal of three SNPs in an M1 strain led to an unexpected number of transcriptomic changes that in part recapitulated transcriptomic changes seen when deleting RofA in the same strain. Computational analysis predicted that interactions with a key histidine residue in the PRD domain of RofA would differ between M1 and M1. RofA is a positive regulator of the pilus locus in all 1 strains but effects on other genes are strain- and lineage-specific, with no clear, common DNA binding motif. The SNPs in that characterize M1 may impact regulation of RofA; whether they alter phosphorylation of the RofA PRD domain requires further investigation.
Topics: Streptococcus pyogenes; Regulon; Bacterial Proteins; Pandemics; United Kingdom
PubMed: 38117674
DOI: 10.1099/mgen.0.001159 -
Journal of Long-term Effects of Medical... 2024Implants play a very crucial role in modern era of medicine and address several needs in all the medical specialties. Both essential and nonessential metals released...
Implants play a very crucial role in modern era of medicine and address several needs in all the medical specialties. Both essential and nonessential metals released from implants at high concentrations can impair biological functions and result in toxicity involving multiple systems of the body. Furthermore, the toxicity information is typically based on exposure through dietary intake and/or occupational/environmental exposure but, since the in vivo implant environment and its composition is different or unknown, individual implants toxic effects needs to be elaborated. Several clinical and nonclinical assessment tools are advised by FDA to evaluate biocompatibility issues, such as risk of immunological response, tissue destruction or overgrowth, and other adverse reactions. The Center for Devices and Radiological Health (CDRH) Biocompatibility Guidelines state that biocompatibility end points caused by metallic implants includes cytotoxicity, sensitization, acute and chronic systemic toxicity, pyrogenicity, genotoxicity, carcinogenicity, implantation, hemocompatibility, reproductive abnormalities, developmental toxicity and biodegradation. Exposure to metal ions which acts as haptens can lead to both local and systemic hypersensitivity reactions which are generally believed to be a Type IV (delayed hypersensitivity) response. Currently, most assessment tools of implant associated hypersensitivity are based on skin sensitization which provides further scopes for research in understanding patient specific immune response causing systemic hypersensitivity.
Topics: Humans; Hypersensitivity; Prostheses and Implants; Skin
PubMed: 37938209
DOI: 10.1615/JLongTermEffMedImplants.2023046417 -
Current Radiopharmaceuticals 2024Arthritis is an inflammatory disorder that affects one or more joints of the body for various reasons, including autoimmune disorders, trauma, or infection. In many...
INTRODUCTION
Arthritis is an inflammatory disorder that affects one or more joints of the body for various reasons, including autoimmune disorders, trauma, or infection. In many cases, traditional long-term treatment with various drug combinations (NSAIDs, diseasemodifying antirheumatic drugs, systemic corticosteroids, etc.) can provide relief, but many joints require additional local treatment. Radiosynovectomy (RSV) is an alternative method to current treatment options. Both the global supply shortage of Y in recent years and the increasing use of Lu-labeled radiopharmaceuticals in the field of nuclear medicine have made it possible to develop Lu-labeled microparticles and test them in small groups as RSV agents. This study aimed to develop the Lu labeled tin colloid formulation and demonstrate its invivo characterization.
MATERIALS AND METHODS
Particle size, shape, and labelling efficiency of the four formulations developed were determined. The formula with the highest labelling efficiency was selected for further studies. The quality of the formulation was evaluated based on radionuclidic, radiochemical, and microbial purity. stability was evaluated by determining the labelling efficiency. stability was tested in PBS and synovial fluid. The biological characterization was assessed using SPECT/CT after injecting the formulation into the normal knee joints of the rabbits.
RESULTS
Aggregated colloidal particles were spherical with a particle size of <5 μm. Labelling efficiency and radiochemical purity were >95 and 97.65% (Rf=0.2), respectively. The formulation was stable for up to 72 hours, both in PBS and synovial fluid. The formulation was homogeneously distributed in the joint at 0 and 1 hour after injection, and radioactivity- related involvement and inguinal lymph node involvement due to possible leakage were not detected in the late period. No pyrogenic/allergic side effects were observed during this period.
CONCLUSION
Lu-tin-colloid was successfully prepared under optimized reaction conditions with high binding efficiency and radiochemical purity. The radiolabeled colloid was found to be stable both in PBS and synovial fluid at room temperature. Serial PCET/CT images revealed that the activity was completely retained within the synovial cavity, with no activity leakage out of the joint until 48 hours after the injection. With the support of the results from further clinical studies, it may be possible for the formulation to enter clinical use.
Topics: Animals; Lutetium; Rabbits; Radiopharmaceuticals; Colloids; Radioisotopes; Tin; Synovectomy; Particle Size; Tissue Distribution; Arthritis
PubMed: 37937551
DOI: 10.2174/0118744710252994231024064842 -
Frontiers in Bioengineering and... 2024Clinical grade magnetic bead implants have important applications in interfacing with the human body, providing contactless mechanical attachment or wireless...
Clinical grade magnetic bead implants have important applications in interfacing with the human body, providing contactless mechanical attachment or wireless communication through human tissue. We recently developed a new strategy, magnetomicrometry, that uses magnetic bead implants as passive communication devices to wirelessly sense muscle tissue lengths. We manufactured clinical-grade magnetic bead implants and verified their biocompatibility via intramuscular implantation, cytotoxicity, sensitization, and intracutaneous irritation testing. In this work, we test the pyrogenicity of the magnetic bead implants via a lagomorph model, and we test the biocompatibility of the magnetic bead implants via a full chemical characterization and toxicological risk assessment. Further, we test the cleaning, sterilization, and dry time of the devices that are used to deploy these magnetic bead implants. We find that the magnetic bead implants are non-pyrogenic and biocompatible, with the insertion device determined to be safe to clean, sterilize, and dry in a healthcare setting. These results provide confidence for the safe use of these magnetic bead implants in humans.
PubMed: 38444650
DOI: 10.3389/fbioe.2024.1290453 -
Environmental Science & Technology Dec 2023Methane (CH) is the second most important greenhouse gas, 27 times as potent as CO and responsible for >30% of the current anthropogenic warming. Globally, more than...
Methane (CH) is the second most important greenhouse gas, 27 times as potent as CO and responsible for >30% of the current anthropogenic warming. Globally, more than half of CH is produced microbially through methanogenesis. Pyrogenic black carbon possesses a considerable electron storage capacity (ESC) and can be an electron donor or acceptor for abiotic and microbial redox transformation. Using wood-derived biochar as a model black carbon, we demonstrated that air-oxidized black carbon served as an electron acceptor to support anaerobic oxidation of organic substrates, thereby suppressing CH production. Black carbon-respiring bacteria were immediately active and outcompeted methanogens. Significant CH did not form until the bioavailable electron-accepting capacity of the biochar was exhausted. An experiment with labeled acetate (CHCOO) yielded 1:1 CH and CO without biochar and predominantly CO with biochar, indicating that biochar enabled anaerobic acetate oxidation at the expense of methanogenesis. Methanogens were enriched following acetate fermentation but only in the absence of biochar. The electron balance shows that approximately half (∼2.4 mmol/g) of biochar's ESC was utilized by the culture, corresponding to the portion of the ESC > +0.173 V (vs SHE). These results provide a mechanistic basis for quantifying the climate impact of black carbon and developing ESC-based applications to reduce CH emissions from biogenic sources.
Topics: Electrons; Carbon Dioxide; Charcoal; Oxidants; Methane; Acetates; Soil
PubMed: 38038997
DOI: 10.1021/acs.est.3c05830