Recent Progress in Cyclic Aryliodonium Chemistry: Syntheses and Applications.

Hypervalent aryliodoumiums are intensively investigated as arylating agents. They are excellent surrogates to aryl halides, and moreover they exhibit better reactivity, which allows the corresponding arylation reactions to be performed under mild conditions. In the past decades, acyclic aryliodoniums are widely explored as arylation agents. However, the unmet need for acyclic aryliodoniums is the improvement of their notoriously low reaction economy because the coproduced aryl iodides during the arylation are often wasted. Cyclic aryliodoniums have their intrinsic advantage in terms of reaction economy, and they have started to receive considerable attention due to their valuable synthetic applications to initiate cascade reactions, which can enable the construction of complex structures, including polycycles with potential pharmaceutical and functional properties. Here, we are summarizing the recent advances made in the research field of cyclic aryliodoniums, including the nascent design of aryliodonium species and their synthetic applications. First, the general preparation of typical diphenyl iodoniums is described, followed by the construction of heterocyclic iodoniums and monoaryl iodoniums. Then, the initiated arylations coupled with subsequent domino reactions are summarized to construct polycycles. Meanwhile, the advances in cyclic aryliodoniums for building biaryls including axial atropisomers are discussed in a systematic manner. Finally, a very recent advance of cyclic aryliodoniums employed as halogen-bonding organocatalysts is described.

A Multi-Omics Study of Epigenetic Changes in Type II Alveolar Cells of A/J Mice Exposed to Environmental Tobacco Smoke.

Lung cancer remains a major contributor to cancer fatalities, with cigarette smoking known to be responsible for up to 80% of cases. Based on the ability of cigarette smoke to induce inflammation in the lungs and increased lung cancer incidence in smokers with inflammatory conditions such as COPD, we hypothesized that inflammation plays an important role in the carcinogenicity of cigarette smoke. To test this hypothesis, we performed multi-omic analyses of Type II pneumocytes of A/J mice exposed to cigarette smoke for various time periods. We found that cigarette smoke exposure resulted in significant changes in DNA methylation and hydroxymethylation, gene expression patterns, and protein abundance that were partially reversible and contributed to an inflammatory and potentially oncogenic phenotype.

Removal of organic pollutants through hydroxyl radical-based advanced oxidation processes.

The use of Advance Oxidation Process (AOPs) has been extensively examined in order to eradicate organic pollutants. This review assesses the efficacy of photolysis, O3 based (O3/UV, O3/H2O2, O3/H2O2/UV, H2O2/UV, Fenton, Fenton-like, hetero-system) and sonochemical and electro-oxidative AOPs in this regard. The main purpose of this review and some suggestions for the advancement of AOPs is to facilitate the elimination of toxic organic pollutants. Initially proposed for the purification of drinking water in 1980, AOPs have since been employed for various wastewater treatments. AOPs technologies are essentially a process intensification through the use of hybrid methods for wastewater treatment, which generate large amounts of hydroxyl (•OH) and sulfate (SO4·-) radicals, the ultimate oxidants for the remediation of organic pollutants. This review covers the use of AOPs and ozone or UV treatment in combination to create a powerful method of wastewater treatment. This novel approach has been demonstrated to be highly effective, with the acceleration of the oxidation process through Fenton reaction and photocatalytic oxidation technologies. It is clear that Advance Oxidation Process are a helpful for the degradation of organic toxic compounds. Additionally, other processes such as •OH and SO4·- radical-based oxidation may also arise during AOPs treatment and contribute to the reduction of target organic pollutants. This review summarizes the current development of AOPs treatment of wastewater organic pollutants.

Co-Doped CeO2/Activated C Nanocomposite Functionalized with Ionic Liquid for Colorimetric Biosensing of H2O2 via Peroxidase Mimicking.

Hydrogen peroxide acts as a byproduct of oxidative metabolism, and oxidative stress caused by its excess amount, causes different types of cancer. Thus, fast and cost-friendly analytical methods need to be developed for H2O2. Ionic liquid (IL)-coated cobalt (Co)-doped cerium oxide (CeO2)/activated carbon (C) nanocomposite has been used to assess the peroxidase-like activity for the colorimetric detection of H2O2. Both activated C and IL have a synergistic effect on the electrical conductivity of the nanocomposites to catalyze the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB). The Co-doped CeO2/activated C nanocomposite has been synthesized by the co-precipitation method and characterized by UV-Vis spectrophotometry, FTIR, SEM, EDX, Raman spectroscopy, and XRD. The prepared nanocomposite was functionalized with IL to avoid agglomeration. H2O2 concentration, incubation time, pH, TMB concentration, and quantity of the capped nanocomposite were tuned. The proposed sensing probe gave a limit of detection of 1.3 × 10-8 M, a limit of quantification of 1.4 × 10-8 M, and an R2 of 0.999. The sensor gave a colorimetric response within 2 min at pH 6 at room temperature. The co-existing species did not show any interference during the sensing probe. The proposed sensor showed high sensitivity and selectivity and was used to detect H2O2 in cancer patients' urine samples.

In-situ synthesized ZIF-67 graphene oxide (ZIF-67/GO) nanocomposite for efficient individual and simultaneous detection of heavy metal ions.

Heavy metals are ubiquitous in water bodies as a result of anthropogenic activities and over time they accumulate in body thus posing serious health problems. Therefore, it is essential to improve sensing performance, for determination of heavy metal ions (HMIs), of electrochemical sensors. In this work, cobalt-derived MOF (ZIF-67) was in-situ synthesized and incorporated onto the surface of graphene oxide (GO) by simple sonication method. The prepared material (ZIF-67/GO) was characterized by FTIR, XRD, SEM, and Raman spectroscopy. Afterwards, a sensing platform was made by drop-casting synthesized composite onto glassy carbon electrode for individual and simultaneous detection of heavy metal ions pollutants (Hg2+, Zn2+, Pb2+, and Cr3+) with estimated detection limits of 2 nM, 1 nM, 5 nM, and 0.6 nM, respectively, when determined simultaneously, that are below the permissible limit by World Health Organization. To the best of our knowledge, this is first report of HMIs detection by ZIF-67 incorporated GO sensor which can successfully determine the Hg+2, Zn+2, Pb+2, and Cr+3 ions simultaneously with lower detection limits.

Characterization of various acrylate based artificial teeth for denture fabrication.

Acrylic resins-based artificial teeth are frequently used for the fabrication of dentures has and contribute a very strong share in the global market. However, the scientific literature reporting the comparative analysis data of various artificial teeth is scarce. Focusing on that, the present study investigated various types of commercially available artificial teeth, composed of polymethyl methacrylate (PMMA). Artificial teeth are characterized for chemical analysis, morphological features, thermal analysis, and mechanical properties (surface hardness, compressive strength). Different types of artificial teeth showed distinct mechanical (compression strength, Vickers hardness) and thermal properties (thermal gravimetric analysis) which may be attributed to the difference in the content of PMMA and type and quantity of different fillers in their composition. Thermogravimetric analysis (TGA) results exhibited that vinyl end groups of PMMA degraded above 200 °C, whereas 340-400 °C maximum degradation temperature was measured by differential thermal analysis (DTA) for all samples. Crisma brand showed the highest compressive strength and young modulus (88.6 MPa and 1654 MPa) while the lowest value of Vickers hardness was demonstrated by Pigeon and Vital brands. Scanning electron microscope (SEM) photographs showed that Crisma, Pigeon, and Vital exhibited characteristics of a brittle fracture; however, Artis and Well bite brands contained elongated voids on their surfaces. According to the mechanical analysis and SEM data, Well bite teeth showed a significantly higher mechanical strength compared to other groups. However, no considerable difference was observed in Vickers hardness of all groups. Graphical abstract.

Spontaneous Orthogonal Protein Crosslinking via a Genetically Encoded 2-Carboxy-4-Aryl-1,2,3-Triazole.

Here we report the design of N2 -carboxy-4-aryl-1,2,3-triazole-lysines (CATKs) and their site-specific incorporation into proteins via genetic code expansion. When introduced into the protein dimer interface, CATKs permitted spontaneous, proximity-driven, site-selective crosslinking to generate covalent protein dimers in living cells, with phenyl-bearing CATK-1 exhibiting high reactivity toward the proximal Lys and Tyr. Furthermore, when introduced into the N-terminal ß-strand of either a single-chain VHH antibody or a supercharged monobody, CATK-1 enabled site-specific, inter-strand, orthogonal crosslinking with a proximal Tyr located on the opposing ß-strand. Compared with a non-crosslinked monobody, the orthogonally crosslinked monobody displayed improved cellular uptake and enhanced proteolytic stability against an endosomal enzyme. The robust crosslinking reactivity of CATKs should facilitate the design of novel protein topologies with improved physicochemical properties.

Capacity development and safety measures for health care workers exposed to COVID-19 in Bangladesh.

BACKGROUND: The safety of health care workers (HCWs) in Bangladesh and the factors associated with getting COVID-19 have been infrequently studied. The aim of this study was to address this gap by assessing the capacity development and safety measures of HCWs in Bangladesh who have been exposed to COVID-19 and by identifying the factors associated with respondents' self-reported participation in capacity development trainings and their safety practices. METHODS: This cross-sectional study was based on an online survey of 811 HCWs working at 39 dedicated COVID-19 hospitals in Bangladesh. A pretested structured questionnaire consisting of questions related to respondents' characteristics, capacity development trainings and safety measures was administered. Binary logistic regressions were run to assess the association between explanatory and dependent variables. RESULTS: Among the respondents, 58.1% had been engaged for at least 2 months in COVID-19 care, with 56.5% of them attending capacity development training on the use of personal protective equipment (PPE), 44.1% attending training on hand hygiene, and 35% attending training on respiratory hygiene and cough etiquette. Only 18.1% reported having read COVID-19-related guidelines. Approximately 50% of the respondents claimed that there was an inadequate supply of PPE for hospitals and HCWs. Almost 60% of the respondents feared a high possibility of becoming COVID-19-positive. Compared to physicians, support staff [odds ratio (OR) 4.37, 95% confidence interval (CI) 2.25-8.51] and medical technologists (OR 8.77, 95% CI 3.14-24.47) were more exhausted from working in COVID-19 care. Respondents with longer duty rosters were more exhausted, and those who were still receiving infection prevention and control (IPC) trainings were less exhausted (OR 0.54, 95% CI 0.34-0.86). Those who read COVID-19 guidelines perceived a lower risk of being infected by COVID-19 (OR 0.44, 95% CI 0.29-0.67). Compared to the respondents who strongly agreed that hospitals had a sufficient supply of PPE, others who disagreed (OR 2.68, 95% CI 1.31-5.51) and strongly disagreed (OR 5.05, 95% CI 2.15-11.89) had a higher apprehension of infection by COVID-19. CONCLUSION: The findings indicated a need for necessary support, including continuous training, a reasonable duty roster, timely diagnosis of patients, and an adequate supply of quality PPE.

Non-enzymatic electrochemical dopamine sensing probe based on hexagonal shape zinc-doped cobalt oxide (Zn-Co2O4) nanostructure.

A non-enzymatic dopamine electrochemical sensing probe was developed. A hexagonal shape zinc-doped cobalt oxide (Zn-Co2O4) nanostructure was prepared by a facile hydrothermal approach. The combination of Zn, which has an abundance of electrons, and Co3O4 exhibited a synergistically electron-rich nanocomposite. The crystallinity of the nanostructure was investigated using X-ray diffraction. A scanning electron microscope (SEM) was used to examine the surface morphology, revealing hexagonal nanoparticles with an average particle size of 400 nm. High-resolution transmission electron microscopy (HR-TEM) was used to confirm the nanostructure of the doped material. The nanostructure's bonding and functional groups were verified using Fourier transform infrared spectroscopy (FTIR). The electrochemical characterization was conducted by using electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and amperometry. The resistivity of the electrode was confirmed through EIS and showed that the bare glassy carbon electrode (GCE) exhibited higher charge transfer resistance as compared to modified Zn-Co2O4/GCE. The sensing probe was developed by modifying the surface of GCE with Zn-Co2O4 nanostructure and tested as an electrochemical sensor for dopamine oxidation; it operated best at a working potential of 0.17 V (vs Ag/AgCl). The developed sensor exhibited a low limit of detection (0.002 µM), a high sensitivity (126 µA. µM-1 cm-2), and a wide linear range (0.2 to 185 µM). The sensor showed a short response time of < 1 s. The sensor's selectivity was investigated in the presence of coexisting species (uric acid, ascorbic acid, adrenaline, epinephrine, norepinephrine, histamine, serotonin, tyramine, phenethylamine, and glucose) with no effects on dopamine determination results. The developed sensor was also successfully used for determining dopamine concentrations in a real sample.

Solid-Phase Synthesis of Hybrid 2,5-Diketopiperazines Using Acylhydrazide, Carbazate, Semicarbazide, Amino Acid, and Primary Amine Submonomers.

We report the solid-phase synthesis of N,N'-di(acylamino)-2,5-diketopiperazine, an acylhydrazide-based conformationally rigid 2,5-DKP scaffold having exocyclic N-N bonds. We also show that different combinations of acylhydrazides, carbazates, semicarbazides, amino acids, and primary amines can be used to synthesize a highly diverse collection of hybrid DKP molecules via the solid-phase submonomer synthesis route. Finally, we show incorporation of a methyl substituent in one of the carbon atoms of the DKP ring to generate chiral daa- and hybrid-DKPs without compromising the synthetic efficiency.

Microwave-assisted synthesis of carbon dots as reductant and stabilizer for silver nanoparticles with enhanced-peroxidase like activity for colorimetric determination of hydrogen peroxide and glucose.

A carbon silver nano-assembly was prepared from silver nanoparticles and carbon dots (AgNP@CD). It was used to quantify hydrogen peroxide and glucose by UV-visible spectroscopy. Banana peels were used to prepare the CDs by a microwave-assisted method. The CDs can be prepared within 5 min at 700 W. They act as (a) substrate, (b) stabilizer, and (c) reductant to convert silver ions to AgNPs. The nano-assembly was characterized by UV-visible spectroscopy, Fourier-transform infrared spectroscopy, atomic force microscopy, and transmission electron microscopy. The CDs have a particle size of 1.4 nm. Photoexcitation of the CDs with a UV lamp of 365 nm results in blue fluorescence. The absorption spectra of the CDs show a peak at 205 nm along the wide shoulder absorption band. On incorporation of the Ag nanoparticles into the CDs matrix, the color of the CDs turns into yellow and an additional absorbance peak at 408 nm appears. FTIR spectroscopy shows that different functional groups are present on the CDs. They are responsible for the stabilization of the AgNPs. On exposure to H2O2, the color of the nano-assembly disappears gradually. Hence, the assembly can be used as a colorimetric indicator probe for H2O2 with a linear response in the 0.1-100 µM concentration range. It can also be applied to the determination of glucose by using glucose oxidase which causes the formation of H2O2 from glucose. The linear response ranges from 1- 600 µM. The detection limits for H2O2 and glucose are 9 nM and 10 nM, respectively. In our perception, this is the lowest detection limit reported so far. The AgNP@CD nano-assembly does not respond to saccharides, maltose, fructose, and lactose. It can be used to quantify glucose in diluted blood plasma. Graphical abstractSchematic representation of microwave-assisted synthesis of AgNP@CDs with enhanced-peroxidase like activity for colorimetric determination of hydrogen peroxide and glucose.

Voltammetric determination of nitrite by using a multiwalled carbon nanotube paste electrode modified with chitosan-functionalized silver nanoparticles.

A cyclic voltammetric method is described for the determination of nitrite by using a multiwalled carbon nanotube paste electrode (MWCNT) that was modified with chitosan-functionalized silver nanoparticles (Chit-AgNPs). The AgNPs were prepared by one step procedure using chitosan as stabilizing agent. The resulting modified AgNPs were drop-coated onto the electrode. By combining the advantages of chitosan, AgNPs (in the form of Chit-AgNPs) and MWCNT, the assay exhibits a remarkable improvement in the cyclic voltammetric response towards the oxidation of nitrite at a typical peak potential of 0.81 V (vs. SCE) in buffer of pH 4.0. The accumulation of nitrite on the electrode also was achieved, and this further enhances the analytical sensitivity. Under optimized conditions, the oxidation peak current increases linearly in the 100 nM to 50 µM nitrite concentration range, and the detection limit is 30 nM. The method has high selectivity for nitrite even in the presence of other potentially interfering ions. Graphical abstract Schematic illustration of the prepared chitosan functionalized silver nanoparticles (transmission electron microscope image) and modification of multi-walled carbon nanotube paste electrode with chitosan functionalized silver nanoparticles for the electrochemical oxidation of nitrite to nitrate.

Nonenzymatic amperometric dopamine sensor based on a carbon ceramic electrode of type SiO2/C modified with Co3O4 nanoparticles.

An amperometric nonenzymatic dopamine sensor has been developed. Cobalt oxide (Co3O4) nanoparticles were uniformly dispersed inside mesoporous SiO2/C. A sol-gel process was used for the preparation of this mesoporous composite material (SiO2/C). This mesoporous composite has a pore size of around 13-14 nm, a large surface area (SBET 421 m2·g-1) and large pore volume (0.98 cm3·g-1) as determined by the BET technique. The material compactness was confirmed by SEM images which showing that there is no phase segregation at the magnification applied. The chemical homogeneity of the materials was confirmed by EDX mapping. The SiO2/C/Co3O4 nanomaterial was pressed in desk format to fabricate a working electrode for nonenzymatic amperometric sensing of dopamine at a pH value of 7.0 and at a typical working potential of 0.25 V vs SCE. The detection limit, linear response range and sensitivity are 0.018 µmol L-1, 10-240 µmol L-1, and 80 µA·µmol L-1 cm-2, respectively. The response timé of the electrode is less than 1 s in the presence of 60 µmol L-1 of dopamine. The sensor showed chemically stability, high sensitivity and is not interfered by other electroactive molecules present in blood. The repeatability of this sensor was evaluated as 1.9% (RSD; for n = 10 at a 40 µmol L-1 dopamine level. Graphical abstract Schematic presentation of the preparation of a nanostructured composite of type SiO2/C/Co3O4 for electrooxidative sensing of dopamine.

Phytochemical and antimicrobial study of Alstonia scholaris leaf extracts against multidrug resistant bacterial and fungal strains.

In the present study, Alstonia scholaris leaves were explored for phytochemical constituents, antibacterial and antifungal potentials. Phytochemical screening of the extracts established the presence of glycosides, alkaloids, saponins, terpenoids, anthraquinones, reducing sugars and steroids which later on confirmed through fourier transform infrared spectroscopic analysis. The extract was applied against eight multidrug resistant bacterial and five fungal strains using standard protocols. Methanol and ethyl acetate extracts of the leaves showed highest diameter of inhibition zone (DIZ) of 28mm and 26mm respectively against Enterobacter. Ethanolic extract exhibited prominent DIZ of 26.33mm and 23.67mm against Enterobacter and Pseudomonas respectively. The n-Hexane extract showed DIZ of 23.67mm against Enterobacter. Aqueous extract showed 19.33mm DIZ against methicillin resistant Staphylococcus aureus. Similarly, the n-hexane extract showed highest DIZ of 20.33mm against Aspergillus fumigatus and this activity was highly effective than the control. Ethyl acetate extract showed 18.67mm DIZ against Aspergillus niger whereas methanolic extract showed marked inhibition against Rhizopus and Acremonium with a DIZ of 20mm and 17.03mm respectively. The current study on A. scholaris unveils about the presence of valuable phytochemicals in it having significant antimicrobial properties and further suggests to investigate for the minimum inhibitory concentration (MIC) value of the extracts in prospective research.

Hepaotoprotective and nephroprotective activities of Pistacia integerrima fruit extract in paracetamol intoxicated male rabbits with effect on blood cells count.

The beneficial effects of Pistacia integerrima (PI) fruit methanol extract on some liver and kidney related parameters and blood cells count of paracetamol (PCM) intoxicated male rabbits were studied. Paracetamol intoxication caused remarkable increase in the serum ALT, AST and ALP levels. The PCM intoxicated rabbits that received PI extract orally at doses of 200 mg and 400 mg/kg b.w. /oral/day for 16 days showed significant reduction in serum ALT, AST and ALP levels (P<0.05). Liver microsections from PCM intoxicated rabbits treated with PI fruit methanol extract showed improvement in the liver histoarchitecture. The urine output of PCM intoxicated control rabbits group was significantly lower (P<0.05). The PCM intoxicated rabbits that received PI extract showed significant increase in urine output (P<0.05). The PCM intoxicated rabbits treated with PI extract also showed significant reduction in the levels of serum urea and creatinine (P<0.05). The renal creatinine clearance of PCM rabbits treated with PI extract improved significantly (P<0.05). Microsections of kidneys from PCM intoxicated rabbits treated with PI fruit methanol extract showed improvement in renal histoarchitecture. During this study, PI extract caused no improvement in the RBC count of PCM intoxicated rabbits. However, the extract caused significant increase in WBC and platelets count (P < 0.05) of PCM intoxicated rabbits. From the findings of the present research, it was concluded that oral administration of P. integerrima fruit methanol extract is beneficial for the liver and kidney related biochemical parameters and blood cells count of paracetamol intoxicated male rabbits.

Ionic liquid coated iron nanoparticles are promising peroxidase mimics for optical determination of H2O2.

Ionic liquid coated nanoparticles (IL-NPs) consisting of zero-valent iron are shown to display intrinsic peroxidase-like activity with enhanced potential to catalyze the oxidation of the chromogenic substrate 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of hydrogen peroxide. This results in the formation of a blue green colored product that can be detected with bare eyes and quantified by photometry at 652 nm. The IL-NPs were further doped with bismuth to enhance its catalytic properties. The Bi-doped IL-NPs were characterized by FTIR, X-ray diffraction and scanning electron microscopy. A colorimetric assay was worked out for hydrogen peroxide that is simple, sensitive and selective. Response is linear in the 30-300 µM H2O2 concentration range, and the detection limit is 0.15 µM. Graphical abstract Schematic of ionic liquid coated iron nanoparticles that display intrinsic peroxidase-like activity. They are capable of oxidizing the chromogenic substrate 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of hydrogen peroxide. This catalytic oxidation generated blue-green color can be measured by colorimetry. Response is linear in the range of 30-300 µM H2O2 concentration, and the detection limit is 0.15 µM.

An Overview on Recent Progress in Electrochemical Biosensors for Antimicrobial Drug Residues in Animal-Derived Food.

Anti-microbial drugs are widely employed for the treatment and cure of diseases in animals, promotion of animal growth, and feed efficiency. However, the scientific literature has indicated the possible presence of antimicrobial drug residues in animal-derived food, making it one of the key public concerns for food safety. Therefore, it is highly desirable to design fast and accurate methodologies to monitor antimicrobial drug residues in animal-derived food. Legislation is in place in many countries to ensure antimicrobial drug residue quantities are less than the maximum residue limits (MRL) defined on the basis of food safety. In this context, the recent years have witnessed a special interest in the field of electrochemical biosensors for food safety, based on their unique analytical features. This review article is focused on the recent progress in the domain of electrochemical biosensors to monitor antimicrobial drug residues in animal-derived food.

In vitro antibacterial activity of selected medicinal plants from lower Himalayas.

The present studies cover antibacterial activity of the crude methanolic extracts of 11 medicinal plants viz. Adhatoda vasica, Bauhenia variegate, Bombax ceiba, Carrisa opaca, Caryopteris grata, Debregeasia salicifolia, Lantana camara, Melia azedarach, Phyllanthus emblica, Pinus roxburghii and Olea ferruginea collected from lower Himalayas against two Gram positive (Staphylococcus aureus, Micrococcus luteus) and two Gram negative (Escherichia coli, Pseudomonas aureginosa) bacterial strains. The extracts were applied at four different concentrations (120 mg/mL, 90mg/mL, 60mg/mL and 30mg/mL) in dimethyl sulfoxide (DMSO) by using agar well diffusion method. Antibacterial activities against Staphylococcus aureus and Micrococcus luteus were observed formethanolic extracts of all the above mentioned plants. Greater antibacterial activity against Pseudomonas aeruginosa was only exhibited by Phyllanthus emblica, Pinus roxburghii, Debregeasia salicifolia and Lantana camara. Escherichia coli was highly resistant to all the plant extracts at all concentrations. It is inferred that methanolic crude extracts of the above mentioned plantsexhibitantibacterial activities against pathogenic bacteria, which proved the ethnobotanical importance of the selected plants that indigenous people use for cure against various diseases.

Evaluation of lead exposure effects on tissue accumulation, behavior, morphological and hemato-biochemical changes in common carp, Cyprinus carpio.

BACKGROUND: Heavy metal pollution, particularly lead (Pb), poses a significant threat to aquatic ecosystems and their inhabitants, threatening their delicate balance and long-term viability. This study highlights the urgent need to mitigate heavy metal pollution in aquatic ecosystems. OBJECTIVE: This study investigates Pb(NO3)2 exposure effects on tissue accumulation, behavioral abnormalities, and hemato-biochemical parameters in common carp (Cyprinus carpio), a widely distributed freshwater fish species. METHODOLOGY: Fish (115 ± 5.23 g) were exposed to various Pb(NO3)2 concentrations for 10 and 20 days, representing control (0 %), 25 %, 50 %, and 75 % of the LC50 equivalent to 19.33, 38.66, and 58.0 mg/l, respectively. The standard manual procedure was used for blood sampling. The lead concentration in fish tissue was determined using an atomic absorption spectrophotometer. RESULTS: Results revealed that fish gills showed significant (P < 0.05) increase in Pb(NO3)2 after 10 days, further rising after 20 days. Liver concentrations also rose significantly (P < 0.05) with prolonged exposure and increasing Pb levels. Muscle had lower concentrations. Hematological parameters (RBC, WBC, HB, HCT) decreased with higher Pb(NO3)2 levels. Behavioral and morphological changes were significantly more pronounced in the exposure groups when compared to the control group. Hepatic enzyme activities (AST, ALT), glucose, and lipid levels increased, while total protein decreased. CONCLUSIONS: The study highlights Pb(NO3)2 harmful effects on common carp, impacting tissue accumulation, hematological parameters, and biochemical disruptions. It emphasizes the need to monitor and mitigate heavy metal pollution in aquatic environments to safeguard freshwater organisms and ecosystems, and to further increase our understanding of Pb toxicity in freshwater ecosystems.

Surface crafting and entrapment of CsPbBr3 perovskite QDs in ZIF-8 for ammonia recognition.

The substantial optical features of perovskite quantum dots (PQD) lead to rapid growth in the investigation of their surface and lattice doping for optoelectronic and biochemical sensor advancements. Herein, we have used the surface ligand crafting model of PQD by ammonia and its optimum response to recognise ammonia in the sensing cellulose paper. The PQD with acetyl amine and octanoic acid capped were synthesized and entrapped in zeolites imidazole framework to delay the instant quenching and envisaged response to ammonia with high sensitivity. The hybrid perovskite quantum dots and Zeolite imidazolate framework-8 (PQD@ZIF-8) materials were further immersed in cellulose paper for solid-state sensor fabrication for the detection of ammonia by naked-eye and a Xiaomi Note-5 mobile camera. The ammonia was measured with high sensitivity at ambient conditions, with a detection limit of 16 ppm and a linear detection range of 1 to 500 ppm. This research provides a new platform for designing sensor selectivity and sensitivity, which could be used to further develop fluorescent nanomaterials-based sensors for small molecule detection.