Ecological versatility and biotechnological promise: Comprehensive characterization of the isolated thermophilic Bacillus strains.

This study focuses on isolated thermophilic Bacillus species' adaptability and physiological diversity, highlighting their ecological roles and potential industrial applications. We specifically investigated their capacity to thrive in extreme conditions by examining their environmental tolerances and adaptations at the metabolic and genetic levels. The primary objective is to evaluate the suitability of these species for biotechnological applications, considering their resilience in harsh environments. We conducted a comparative analysis of the environmental adaptability parameters for various Bacillus species. This included examining growth temperature ranges, pH tolerance, oxygen requirements, carbohydrate fermentation patterns, colony morphology, enzymatic activities, and genetic properties. Controlled laboratory experiments provided the data, which were then analyzed to determine patterns of adaptability and diversity. The research revealed that Bacillus species could endure temperatures as high as 73°C, with a generally lower growth limit at 43°C. However, strains TBS35 and TBS40 were exceptions, growing at 37°C. Most strains preferred slightly alkaline conditions (optimal pH 8), but TBS34, TBS35, and TBS40 exhibited adaptations to highly alkaline environments (pH 11). Oxygen requirement tests classified the species into aerobic, anaerobic, and facultative aerobic categories. Genetic analysis highlighted variations in DNA concentrations, 16s rRNA gene lengths, and G+C content across species. Although glucose was the primary substrate for carbohydrate fermentation, exceptions indicated metabolic flexibility. The enzymatic profiles varied, with a universal absence of urease and differences in catalase and oxidase production. Our findings underscore thermophilic Bacillus species' significant adaptability and diversity under various environmental conditions. Their resilience to extreme temperatures, pH levels, varied oxygen conditions, and diverse metabolic and genetic features emphasize their potential for biotechnological applications. These insights deepen our understanding of these species' ecological roles and highlight their potential industrial and environmental applications.

Magnetic iron oxide-based nanozymes: from synthesis to application.

Iron oxide nanozymes (IONzymes) are a class of magnetic nanoparticles that mimic the enzymatic activity of natural enzymes. These particles have received significant attention in recent years due to their unique properties, such as high stability, tunable magnetic responsiveness, and ability to act as biocatalysts for various chemical reactions. In this review, we aim to provide an overview of the production methods of magnetic nanozymes, including chemical, physical, and biological synthesis. The structure and design of magnetic nanozymes are also discussed in detail, as well as their applications in various fields such as biomedicine and environmental science. The results of various studies and the latest advances in the field of magnetic nanozymes are also discussed. This review provides valuable insights into the current state of magnetic nanozymes and highlights their potential for further development and application in various fields.

Anti­angiogenic and cytotoxic evaluation of green­synthesized Fe2ZnO4 nanoparticles against MCF­7 cell line.

The use of plants for nanoparticle (NP) synthesis, grounded in green chemistry principles, is an environmentally friendly and economically viable approach. In the present study, the leaf extract of Elaeagnus angustifolia L. was used as a biosynthetic agent to generate bimetallic zinc oxide NPs. The present study investigated the effect of ZnO NPs on anti-angiogenesis and cell migration. Various bimetallic NPs, including zinc-iron oxide and nickel-zinc oxide, underwent characterization through Fourier-transform infrared spectroscopy and X-ray Diffraction within the 25-65˚ range. Confirmation of NP formation was determined by identifying the surface plasmon resonance peak. MTT assay was used to determine the cytotoxic properties of E. angustifolia L. extracts, ZnO NPs and associated metals in MCF-7 breast cancer cells. The plant extract demonstrated antiproliferative effects at 200 µg/ml, whereas E. ang-Fe2ZnO4 NPs showed varying cytotoxic effects based on concentration. The rat aortic ring and cell migration assays illuminated anti-angiogenic attributes, with the E. ang-Fe2ZnO4 NPs blocking blood vessel development entirely at 100 µg/ml, implying profound anti-angiogenic efficacy. Therefore, E. ang-Fe2ZnO4 NPs may serve a role in antiangiogenic therapy.

Integrated water quality dynamics in Wadi Hanifah: Physical, chemical, and biological perspectives.

The Wadi Hanifah, a crucial aquatic ecosystem, has unfavorable consequences from natural occurrences and human activities. Recognizing the critical need for sustainable water management, this study provides an in-depth evaluation of wadi water quality. A comprehensive assessment was conducted, analyzing physical properties (temperature, pH, electrical conductivity, turbidity, color, and odor), chemical constituents (nitrogen compounds, ion concentrations, heavy metals), and bacterial diversity. The study found significant temperature fluctuations, particularly in sun-exposed or stagnant water areas. The water exhibited slight alkalinity and variable electrical conductivity and turbidity, indicating differing pollution levels. High ammonia and heavy metal concentrations suggested organic and industrial contamination, respectively. In addition, the prevalent fecal-indicator bacteria pointed to possible sewage or agricultural runoff. The research highlights the complex interplay of natural and anthropogenic factors affecting Wadi Hanifah's water quality. It emphasizes the need for location-specific environmental management strategies focusing on pollution control and conservation to safeguard the wadi's ecological health. This study provides vital insights for effective water resource management in Wadi Hanifah, serving as a model for similar ecosystems.

Anti-Inflammatory and Antioxidant Effects of Rosmarinic Acid Trimetallic (Cu0.5Zn0.5Fe2O4) Nanoparticles.

Newly, green metallic-nanoparticles (NPs) have received scientists' interest due to their wide variable medicinal applications owned to their economical synthesis and biologically compatible nature. In this study, we used rosmarinic acid (RosA) to prepare Cu0.5Zn0.5FeO4 NPs and later encapsulated them using PEG polymer. Characterization of NPs was done using the XRD method and SEM imaging. Further, we explored the encapsulated NPs for anti-inflammatory properties by downregulating the expression of pro-inflammatory cytokines mRNA in LPS-stimulated Raw 264.7 cells. Besides, employing DPPH, NO and ABTS radical scavenging assays to examine the antioxidant activity of the synthesized Cu0.5Zn0.5FeO4 NPs. Cu0.5Zn0.5FeO4 NPs revealed moderate antioxidant activity by scavenging DPPH and nitric oxide. We demonstrated that the NPs showed high potential anti-inflammatory activity by suppressing the mRNA and protein levels of pro-inflammatory cytokines in a dose-dependent manner, in LPS-induced Raw 264.7 cells. To our best knowledge, this is the first report where RosA was found to be a suitable phyto source for the green synthesis of Cu0.5Zn0.5FeO4 NPs and their in vitro anti-inflammatory and antioxidant effects. Taken together, our findings suggest that the RosA is a green resource for the eco-friendly synthesis of Cu0.5Zn0.5FeO4/PEG NPs, which further can be employed as a novel anti-inflammatory therapeutic agent.

Enzyme Production and Inhibitory Potential of Pseudomonas aeruginosa: Contrasting Clinical and Environmental Isolates.

(1) Background: This study summarizes the findings of two studies investigating the inhibitory effects of Pseudomonas aeruginosa strains from clinical and environmental sources against gram-positive and gram-negative bacteria and fungi. The studies also analyzed the correlation between enzyme production and inhibitory effects to gain insights into the antimicrobial capabilities of P. aeruginosa strains; (2) Methods: Both studies employed similar methodologies, including the use of disk diffusion and well diffusion methods to assess the inhibitory effects of P. aeruginosa strains against target pathogens. Enzyme production was analyzed through various biochemical assays to determine the diversity and frequencies of enzyme secretion among the strains; (3) Results: A comparative analysis of enzyme production in P. aeruginosa strains from clinical sources revealed significant variations in enzyme production, with hemolysin and protease being the most commonly produced enzymes. Gelatinase production showed lower rates, whereas chondroitinase and hyaluronidase were absent or occurred less frequently. In contrast, a comparative analysis of enzyme production in environmental isolates showed different patterns, indicating adaptation to environmental conditions. Pyocyanin production was absent in all environmental isolates. The inhibitory effects against gram-positive and gram-negative bacteria varied among different P. aeruginosa strains, with strain-specific variations observed. Limited inhibitory effects were observed against fungi, primarily toward gram-positive bacteria; (4) Conclusions: The findings highlight the strain-specific nature of inhibitory effects and enzyme production in P. aeruginosa strains. The correlation between enzyme production and inhibitory effects against gram-positive bacteria suggest a potential role of specific enzymes, such as hemolysin and protease, in the antimicrobial activity. The complexity of the relationship between enzyme production and the inhibition of different pathogens requires further investigation. The results emphasize the potential of P. aeruginosa strains as sources for antimicrobial strategies, particularly against gram-positive bacteria. Future research should focus on understanding the mechanisms underlying these inhibitory effects and exploring their therapeutic applications.

Catalytic behaviour of the Cu(i)/L/TEMPO system for aerobic oxidation of alcohols - a kinetic and predictive model.

Here, we disclose a new copper(i)-Schiff base complex series for selective oxidation of primary alcohols to aldehydes under benign conditions. The catalytic protocol involves 2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO), N-methylimidazole (NMI), ambient air, acetonitrile, and room temperature. This system provides a straightforward and rapid pathway to a series of Schiff bases, particularly, the copper(i) complexes bearing the substituted (furan-2-yl)imine bases N-(4-fluorophenyl)-1-(furan-2-yl)methanimine (L2) and N-(2-fluoro-4-nitrophenyl)-1-(furan-2-yl)methanimine (L4) have shown excellent yields. Both benzylic and aliphatic alcohols were converted to aldehydes selectively with 99% yield (in 1-2 h) and 96% yield (in 16 h). The mechanistic studies via kinetic analysis of all components demonstrate that the ligand type plays a key role in reaction rate. The basicity of the ligand increases the electron density of the metal center, which leads to higher oxidation reactivity. The Hammett plot shows that the key step does not involve H-abstraction. Additionally, a generalized additive model (GAM, including random effect) showed that it was possible to correlate reaction composition with catalytic activity, ligand structure, and substrate behavior. This can be developed in the form of a predictive model bearing in mind numerous reactions to be performed or in order to produce a massive data-set of this type of oxidation reaction. The predictive model will act as a useful tool towards understanding the key steps in catalytic oxidation through dimensional optimization while reducing the screening of statistically poor active catalysis.

A di­iron(III) µ-oxido complex as catalyst precursor in the oxidation of alkanes and alkenes.

The oxido-bridged diiron(III) complex [Fe2(µ-O)(µ-OAc)(DPEAMP)2](OCH3) (1), based on a new unsymmetrical ligand with an N4O donor set, viz. [2-((bis(pyridin-2-ylmethyl)amino)methyl)-6-((ethylamino)methyl)-4-methylphenol (HDPEAMP)], has been prepared and characterized by spectroscopic methods and X-ray crystallography. The crystal structure of the complex reveals that each Fe(III) ion is coordinated by three nitrogen and three oxygen donors, two of which are the bridging oxido and acetate ligands. Employing H2O2 as a terminal oxidant, 1 is capable of oxidizing a number of alkanes and alkenes with high activity. The catalytic oxidation of 1,2-dimethylcyclohexane results in excellent retention of configuration. Monitoring of the reaction of 1 with H2O2 and acetic acid in the absence of substrate, using low-temperature UV-Vis spectroscopy, suggests the in situ formation of a transient Fe(III)2-peroxido species. While the selectivity and nature of oxidation products implicate a high-valent iron-oxido complex as a key intermediate, the low alcohol/ketone ratios suggest a simultaneous radical-based process.

Nano-Magnetic NiFe2O4 and Its Photocatalytic Oxidation of Vanillyl Alcohol-Synthesis, Characterization, and Application in the Valorization of Lignin.

Here, we report on a phyto-mediated bimetallic (NiFe2O4) preparation using a Boswellia carterii extract, which was characterized by XRD, FT-IR, TGA, electron microscopy, magnetic spectroscopy, and Mössbauer spectroscopy measurements. The prepared nano-catalysts were tested for oxidation of lignin monomer molecules-vanillyl alcohol and cinnamyl alcohol. In comparison with previously reported methods, the nano NiFe2O4 catalysts showed high photocatalytic activity and selectivity, under visible light irradiation with a nitroxy radical initiator (2,2,6,6-tetramethylpiperidinyloxy or 2,2,6,6-tetramethylpiperidine 1-oxyl; TEMPO) at room temperature and aerobic conditions. The multifold advantages of the catalyst both in terms of reduced catalyst loading and ambient temperature conditions were manifested by higher conversion of the starting material.

Indoor Model Simulation for COVID-19 Transport and Exposure.

Transmission of respiratory viruses is a complex process involving emission, deposition in the airways, and infection. Inhalation is often the most relevant transmission mode in indoor environments. For severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the risk of inhalation transmission is not yet fully understood. Here, we used an indoor aerosol model combined with a regional inhaled deposited dose model to examine the indoor transport of aerosols from an infected person with novel coronavirus disease (COVID-19) to a susceptible person and assess the potential inhaled dose rate of particles. Two scenarios with different ventilation rates were compared, as well as adult female versus male recipients. Assuming a source strength of 10 viruses/s, in a tightly closed room with poor ventilation (0.5 h-1), the respiratory tract deposited dose rate was 140-350 and 100-260 inhaled viruses/hour for males and females; respectively. With ventilation at 3 h-1 the dose rate was only 30-90 viruses/hour. Correcting for the half-life of SARS-CoV-2 in air, these numbers are reduced by a factor of 1.2-2.2 for poorly ventilated rooms and 1.1-1.4 for well-ventilated rooms. Combined with future determinations of virus emission rates, the size distribution of aerosols containing the virus, and the infectious dose, these results could play an important role in understanding the full picture of potential inhalation transmission in indoor environments.

In vitro anti-inflammatory and antioxidant activities of ZnFe2 O4 and CrFe2 O4 nanoparticles synthesized using Boswellia carteri resin.

The development of plant-based nano-materials is considered an eco-friendly technology because it does not involve hazardous chemicals. In this study, bimetallic ZnFe2 O4 and CrFe2 O4 nanoparticles were synthesized using an aqueous extract of Boswellia carteri resin. Synthesized ZnFe2 O4 and CrFe2 O4 nanoparticles were characterized by UV-Vis spectroscopy, FTIR, XRD, and HR-TEM. The anti-inflammatory activity was investigated in LPS-stimulated RAW 264.7 macrophages, whereas antioxidant activity was examined using a Hydrogen Peroxide Scavenging Activity Assay, Nitric Oxide Scavenging Activity Assay, and ABTS Radical Scavenging Assay. ZnFe2 O4 and CrFe2 O4 nanoparticles demonstrated a moderate scavenger of H2 O2 with IC50 values; 87.528 ± 8 µg/ml and 146.4468 ± 12 µg/ml, respectively. While they exhibited a strong scavenger of NO with IC50 values; 4.01 ± 0.7 µg/ml and 4.01 ± 0.7µg/ml, respectively. Interestingly, ZnFe2 O4 and CrFe2 O4 nanoparticles revealed an excellent anti-inflammatory activity by dose-dependently suppressing mRNA expressions of IL-1b, IL-6, and TNF-α. Also, ZnFe2 O4 and CrFe2 O4 nanoparticles suppress the protein expression of TNF-α. Together, our results proved that phyto-mediated ZnFe2 O4 and CrFe2 O4 nanoparticles using Boswellia carteri resin have great potential in biomedical applications such as anti-inflammatory and antioxidant. PRACTICAL APPLICATIONS: Our phyto-synthesized chromium iron oxide bimetallic nanoparticles (NPs) have shown a novel and potent anti-inflammatory activity, with remarkable biosafety toward tested macrophages. Zinc iron oxide bimetallic NPs exhibited anti-inflammatory effect with a lesser extent compared to the former, with moderate cytotoxicity against tested macrophages. Both zinc and chromium iron oxide NPs exhibited an equivalent antioxidant activity. Our resin-capped chromium iron oxide NPs are suggested to be a competing nonsteroidal anti-inflammatory agent; it is further recommended to establish advanced animal studies to confirm their biosafety, stability, and anti-inflammatory activity accompanied with the antioxidant activity.

Phyto-Facilitated Bimetallic ZnFe2O4 Nanoparticles via Boswellia carteri: Synthesis, Characterization, and Anti-Cancer Activity.

BACKGROUND: The growing dissatisfaction with the available traditional chemotherapeutic agents has enhanced the need to develop new methods for obtaining materials with more effective and safe anti-cancer properties. Over the past few years, the usage of metallic nanoparticles has been a target for researchers of different scientific and commercial fields due to their tiny sizes, environment-friendly properties, and a wide range of applications. To overcome the obstacles of traditional physical and chemical methods for the synthesis of such nanoparticles, a new, less expensive, and eco-friendly method has been adopted using natural existing organisms as a reducing agent to mediate the synthesis of the desired metallic nanoparticles from their precursors, a process called green biosynthesis of nanoparticles. OBJECTIVE: In the present study, zinc-iron bimetallic nanoparticles (ZnFe2O4) were synthesized via an aqueous extract of Boswellia carteri resin mixed with zinc acetate and iron chloride precursors, and they were tested for their anticancer activity. METHODS: Various analytic methods were applied for the characterization of the phyto synthesized ZnFe2O4, and they were tested for their anticancer activity against MDA-MB-231, K562, MCF-7 cancer cell lines, and normal fibroblasts. RESULTS: Our results demonstrate the synthesis of cubic structured bimetallic nanoparticles ZnFe2O4 with an average diameter of 10.54 nm. MTT cytotoxicity assay demonstrates that our phyto-synthesized ZnFe2O4 nanoparticles exhibited a selective and potent anticancer activity against K562 and MDA-MB-231 cell lines with IC50 values 4.53 µM and 4.19 µM, respectively. CONCLUSION: In conclusion, our biosynthesized ZnFe2O4 nanoparticles show a promising, environmentally friendly, and low coast chemotherapeutic approach against selective cancers with a predicted low adverse side effect toward normal cells. Further, in vivo, advanced animal research should be done to execute their applicability in living organisms.

Elemental Contamination in Indoor Floor Dust and Its Correlation with PAHs, Fungi, and Gram+/- Bacteria.

In this study, we performed elemental analysis for floor dust samples collected in Jordanian microenvironments (dwellings and educational building). We performed intercorrelation and cluster analysis between the elemental, polyaromatic hydrocarbon (PAH), and microorganism concentrations. In general, the educational building workshops had the highest elemental contamination. The age of the dwelling and its occupancy played a role on the elemental contamination level: older and more occupied dwellingshad greater contamination. The elemental contamination at a dwelling entrance was observed to be higher than in the living room. We found exceptionally high concentrations for Fe and Mn in the educational workshop and additionally, Hg, Cr, and Pb concentrations exceeded the limits set by the Canadian Council of Ministers of the Environment. According to the cluster analysis, we found three major groups based on location and contamination. According to the enrichment factor (EF) assessment, Al, Co, Mn, Ti, and Ba had EF < 2 (i.e., minimal enrichment) whereas P, S, Pb, Sb, Mo, Zn, Hg, and Cu had EF > 40 (i.e., extremely enriched). In contrast, Ca and P were geogenically enriched. Furthermore, significant Spearman correlations indicated nine subgroups of elemental contamination combined with PAHs and microbes.

Di- and Tetrairon(III) µ-Oxido Complexes of an N3S-Donor Ligand: Catalyst Precursors for Alkene Oxidations.

The new di- and tetranuclear Fe(III) µ-oxido complexes [Fe4(µ-O)4(PTEBIA)4](CF3SO3)4(CH3CN)2] (1a), [Fe2(µ-O)Cl2(PTEBIA)2](CF3SO3)2 (1b), and [Fe2(µ-O)(HCOO)2(PTEBIA)2](ClO4)2 (MeOH) (2) were prepared from the sulfur-containing ligand (2-((2,4-dimethylphenyl)thio)-N,N-bis ((1-methyl-benzimidazol-2-yl)methyl)ethanamine (PTEBIA). The tetrairon complex 1a features four µ-oxido bridges, while in dinuclear 1b, the sulfur moiety of the ligand occupies one of the six coordination sites of each Fe(III) ion with a long Fe-S distance of 2.814(6) Å. In 2, two Fe(III) centers are bridged by one oxido and two formate units, the latter likely formed by methanol oxidation. Complexes 1a and 1b show broad sulfur-to-iron charge transfer bands around 400-430 nm at room temperature, consistent with mononuclear structures featuring Fe-S interactions. In contrast, acetonitrile solutions of 2 display a sulfur-to-iron charge transfer band only at low temperature (228 K) upon addition of H2O2/CH3COOH, with an absorption maximum at 410 nm. Homogeneous oxidative catalytic activity was observed for 1a and 1b using H2O2 as oxidant, but with low product selectivity. High valent iron-oxo intermediates could not be detected by UV-vis spectroscopy or ESI mass spectrometry. Rather, evidence suggest preferential ligand oxidation, in line with the relatively low selectivity and catalytic activity observed in the reactions.

A Predictive Model for Steady State Ozone Concentration at an Urban-Coastal Site.

Ground level ozone (O3) plays an important role in controlling the oxidation budget in the boundary layer and thus affects the environment and causes severe health disorders. Ozone gas, being one of the well-known greenhouse gases, although present in small quantities, contributes to global warming. In this study, we present a predictive model for the steady-state ozone concentrations during daytime (13:00⁻17:00) and nighttime (01:00⁻05:00) at an urban coastal site. The model is based on a modified approach of the null cycle of O3 and NOx and was evaluated against a one-year data-base of O3 and nitrogen oxides (NO and NO2) measured at an urban coastal site in Jeddah, on the west coast of Saudi Arabia. The model for daytime concentrations was found to be linearly dependent on the concentration ratio of NO2 to NO whereas that for the nighttime period was suggested to be inversely proportional to NO2 concentrations. Knowing that reactions involved in tropospheric O3 formation are very complex, this proposed model provides reasonable predictions for the daytime and nighttime concentrations. Since the current description of the model is solely based on the null cycle of O3 and NOx, other precursors could be considered in future development of this model. This study will serve as basis for future studies that might introduce informing strategies to control ground level O3 concentrations, as well as its precursors' emissions.

Floor dust bacteria and fungi and their coexistence with PAHs in Jordanian indoor environments.

Floor dust samples were collected from Jordanian indoor environments (eight dwellings and an educational building) in Amman. Quantitative PCR (qPCR) analyses of selected fungal and bacterial groups were performed. The bacterial and fungal concentrations were also correlated with PAHs concentrations, which were previously measured in the same samples by using GC-MS. The bacterial and fungal concentrations varied significantly among and within the tested indoor environments. Based on the collected samples in the entrance area of the dwellings, the largest variation was found in Gram-negative bacteria and total fungi concentration. The lowest bacterial and fungal concentrations were found in the dwelling that was least occupied and the most recently built. At the educational building, the Gram-positive bacteria concentrations were lower than those observed in the dwellings. Unlike for bacteria, we observed significant negative correlation with some polycyclic aromatic hydrocarbons (PAHs). This calls for further studies investigating biodegradation of PAHs in house dust and presence of potentially health hazardous PAH metabolites. Since biocontamination in floor dust has been given relatively little to no attention in the MENA region we recommend that more extensive measurements be conducted in the future with chemical and biological analysis of floor dust contaminants and their exposure indoors.

Chemical investigation and quality of urban dew collections with dust precipitates.

The quality and chemical composition of urban dew collections with dust precipitates without pre-cleaning of the collecting surface WSF (white standard foil) were investigated for 16 out of 20 collected samples with collected volumes ranging from 22 to 230 ml. The collection period was from March to July 2015 at an urban area, Jubaiha, which is located in the northern part of the capital city Amman, Jordan. The obtained results indicated the predominance of Ca2+ and SO42- ions (ratio 2.2:1) that originated from Saharan soil dust; where the collected samples were alkaline (mean pH = 7.35) with high mineralization (429.22 mg/L) exceeding the previously reported dew values in Amman-Jordan. A relocation of NaCl and to a less extent Mg2+ from sea to land by Saharan wind is indicated by the percent sea-salt fraction calculations (over 100 and 52, respectively). The collected samples exhibited high total organic carbon (TOC) values ranging from 11.86 to 74.60 mg/L, presence of particulate settled material with turbidity ranging from 20.10 to 520.00 NTU, and presence of undesired elements like boron (mean = 1.48 mg/L) that made it different in properties from other dew water collections at clean surfaces, and exceeding the standard limits for drinking water for these parameters set by Jordanian Drinking Water standards (JS286/2015)/WHO standard. The quality of this water is more close to that for raw or agricultural water but if it is meant to be used as potable source of water, at least sand and activated charcoal filters are needed to purify it.

Occupational health risk assessment and exposure to floor dust PAHs inside an educational building.

Polycyclic aromatic hydrocarbons (PAHs) settled in floor dust play an important role in human health. Although many studies investigated occupational exposure to PAHs, no attempts have been made to report PAHs concentrations as well as their health risk assessment inside an educational building in Jordan. Therefore, the main objective of this study is to report the PAHs concentrations in floor dust and evaluate their exposure and health risk inside the Department of Physics of the University of Jordan. The total PAHs concentrations ranged from 714 to 5246ng/g. The high concentrations were observed inside some offices, where tobacco smoking took place. One of those offices was previously renovated and some petrochemical liquids were used to remove the remaining glue from a previous carpet. Interestingly, the PAHs inside these offices were higher than those reported inside lecture rooms and the workshop area, where extensive activates of heavy machinery and use of petroleum products (such as lubricating oils). This implies that the health effects of exposure to tobacco smoking inside small micro-environmental places that are poorly ventilated can be very harmful. We also made a simple exposure and health risk assessment for the ingested dust (hand-to-mouth) by calculating the Estimated Daily Intake (EDI) and benzo(a)pyrene equivalent carcinogenic power (BaPE). The total EDI was less than 3.75ng/kg-bw/day whereas the BaPE was less than 385ng/g. These values are lower than what was reported in some previous studies in Europe and Asia.

From DNA to catalysis: a thymine-acetate ligated non-heme iron(III) catalyst for oxidative activation of aliphatic C-H bonds.

A non-heme, iron(III)/THA(thymine-1-acetate) catalyst together with H2O2 as an oxidant is efficient in oxidative C-H activation of alkanes. Although having a higher preference for tertiary C-H bonds, the catalyst also oxidizes aliphatic secondary C-H bonds into carbonyl compounds with good to excellent conversions. Based on the site selectivity of the catalyst and our mechanistic studies the reaction proceeds via an Fe-oxo species without long lived carbon centered radicals.

Solvent free oxidation of primary alcohols and diols using thymine iron(III) catalyst.

In this study, we developed an efficient and selective iron-based catalyst system for the synthesis of ketones from secondary alcohols and carboxylic acids from primary alcohol. In situ generated iron catalyst of thymine-1-acetate (THA) and FeCl(3) under solvent-free condition exhibits high activity. As an example, 1-octanol and 2-octanol were oxidized to 1-octanoic acid and 2-octanone with 89% and 98% yields respectively.