Source, distribution and emerging threat of micro- and nanoplastics to marine organism and human health: Socio-economic impact and management strategies.

The nature of micro- and nanoplastics and their harmful consequences has drawn significant attention in recent years in the context of environmental protection. Therefore, this paper aims to provide an overview of the existing literature related to this evolving subject, focusing on the documented human health and marine environment impacts of micro- and nanoplastics and including a discussion of the economic challenges and strategies to mitigate this waste problem. The study highlights the micro- and nanoplastics distribution across various trophic levels of the food web, and in different organs in infected animals which is possible due to their reduced size and their lightweight, multi-coloured and abundant features. Consequently, micro- and nanoplastics pose significant risks to marine organisms and human health in the form of cytotoxicity, acute reactions, and undesirable immune responses. They affect several sectors including aquaculture, agriculture, fisheries, transportation, industrial sectors, power generation, tourism, and local authorities causing considerable economic losses. This can be minimised by identifying key sources of environmental plastic contamination and educating the public, thus reducing the transfer of micro- and nanoplastics into the environment. Furthermore, the exploitation of the potential of microorganisms, particularly those from marine origins that can degrade plastics, could offer an enhanced and environmentally sound approach to mitigate micro- and nanoplastics pollution.

Antibacterial Activities of Methanolic Seeds Extract of Black pepper (Piper nigrum L.) against Gram Positive Staphylococcus aureus & Gram-Negative Escherichia coli.

Evaluation of the in vitro antibacterial activity of Methanolic extracts isolated from Black pepper seeds (Piper nigrum L.) against two infection causing pathogens, Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. Between July 2022 and June 2023, this experimental study was conducted at the Mymensingh Medical College's Department of Pharmacology and Therapeutics in conjunction with the Department of Microbiology. Using the disc diffusion and broth dilution methods, the antibacterial activity of methanolic extract of black pepper seeds (MBPE) was evaluated at various doses. The solvents Methanol and 10.0% Di Methyl Sulfoxide (DMSO) were used to make the extract. Using the broth dilution procedure, the conventional antibiotic Ciprofloxacin was utilized and the outcome was contrasted with that of Methanol extracts. Methanolic extract of black pepper seeds (MBPE) at seven distinct concentrations (100, 80, 60, 40, 20, 10 and 5 mg/ml) were utilized, then later in chosen concentrations as needed to confirm the extracts' more precise margin of antimicrobial sensitivity. At 80 mg/ml and above doses of the MBPE, it had an inhibitory impact against the aforementioned microorganisms. For Staphylococcus aureus and Escherichia coli the MIC were 60 and 75 mg/ml in MBPE respectively. As of the MIC of Ciprofloxacin was 1µg/ml against Staphylococcus aureus and Escherichia coli. In comparison to MICs of MBPE for the test organisms, the MIC of Ciprofloxacin was the lowest. This study clearly shows that Staphylococcus aureus and Escherichia coli are sensitive to the methanolic extract of black pepper seeds' antibacterial properties.

Intercalative pyrimido[4',5':4,5]thieno(2,3-b)quinolines induce apoptosis in leukemic cells: a comparative study of methoxy and morpholino substitution.

DNA intercalating molecules are promising anticancer agents. Polycyclic aromatic molecules such as ellipticine intercalate into double-stranded DNA and affect major physiological functions. In the present study, we have characterized two molecules with the same chemical backbone but different side chains, namely 8-methoxy pyrimido[4',5':4,5]thieno (2,3-b)quinoline-4(3H)-one (MPTQ) and 4-morpholino pyrimido[4',5':4,5]thieno(2,3-b)quinoline (morpho-PTQ) at the 8th and 4th position, respectively. Although both MPTQ and morpho-PTQ show similar biophysical properties with high DNA affinity, here we show that they differ in their biological activities. We find that MPTQ is many fold more potent than morpho-PTQ and is cytotoxic against different leukemic cell lines. IC(50) value of methoxy PTQ was estimated between 2-15 µM among the leukemic cells studied, while it was more than 200 µM when morpho-PTQ was used. Cell cycle analysis shows an increase in sub-G1 phase, without any particular cell cycle arrest. Annexin V staining in conjunction with comet assay and DNA fragmentation suggest that MPTQ induces cytotoxicity by activating apoptosis. Thus the observed low IC(50) value of MPTQ makes it a promising cancer chemotherapeutic agent.

A novel structural derivative of natural alkaloid ellipticine, MDPSQ, induces necrosis in leukemic cells.

DNA intercalating molecules are promising chemotherapeutic agents. In the present study, a novel DNA intercalating compound of pyrimido[4',5':4,5]selenolo(2,3-b)quinoline series having 8-methyl-4-(3 diethylaminopropylamino) side chain is studied for its chemotherapeutic properties. Our results showed that 8-methyl-4-(3 diethylaminopropylamino) pyrimido [4',5':4,5] selenolo(2,3-b)quinoline (MDPSQ) induces cytotoxicity in a time- and concentration-dependent manner on leukemic cell lines. Both cell cycle analysis and tritiated thymidine assays revealed that MDPSQ affects DNA replication. Treatment with MDPSQ resulted in both elevated levels of DNA strand breaks and repair proteins, further indicating its cytotoxic effects. Besides, Annexin V/PI staining revealed that MDPSQ induces cell death by triggering necrosis rather than apoptosis.

A novel DNA intercalator, butylamino-pyrimido[4',5':4,5]selenolo(2,3-b)quinoline, induces cell cycle arrest and apoptosis in leukemic cells.

DNA intercalators are one of the most commonly used chemotherapeutic agents. Novel intercalating compounds of pyrimido[4',5':4,5]selenolo(2,3-b)quinoline series having a butylamino or piperazino group at fourth position (BPSQ and PPSQ, respectively) are studied. Our results showed that BPSQ induced cytotoxicity whereas PPSQ was cytostatic. The cytotoxicity induced by BPSQ was concentration- and time-dependent. Cell cycle analysis and tritiated thymidine assay revealed that BPSQ affects the cell cycle progression by arresting at S phase. The absence of p-histone H3 and reduction in the levels of PCNA in the cells treated with BPSQ further confirmed the cell cycle arrest. Further, annexin V staining, DNA fragmentation, nuclear condensation and changes in the expression levels of BCL2/BAD confirmed the activation of apoptosis. Activation of caspase 8 and lack of cleavage of caspase 9, caspase 3 and PARP suggest the possibility of BPSQ triggering extrinsic pathway for induction of apoptosis, which is discussed. Hence, we have identified a novel compound which would have clinical relevance in cancer chemotherapeutics.

Advances in the thermo-chemical production of hydrogen from biomass and residual wastes: Summary of recent techno-economic analyses.

This article outlines the prospects and challenges of hydrogen production from biomass and residual wastes, such as municipal solid waste. Recent advances in gasification and pyrolysis followed by reforming are discussed. The review finds that the thermal efficiency of hydrogen from gasification is ~50%. The levelized cost of hydrogen (LCOH) from biomass varies from ~2.3-5.2 USD/kg at feedstock processing scales of 10 MWth to ~2.8-3.4 USD/kg at scales above 250 MWth. Preliminary estimates are that the LCOH from residual wastes could be in the range of ~1.4-4.8 USD/kg, depending upon the waste gate fee and project scale. The main barriers to development of waste to hydrogen projects include: waste pre-treatment, technology maturity, syngas conditioning, the market for clean hydrogen, policies to incentivize pioneer projects and technology competitiveness. The main opportunity is to produce low cost clean hydrogen, which is competitive with alternative production routes.

Fine needle aspiration cytology of epididymal nodules and its corroboration with ultrasonographic-histological findings.

BACKGROUND: Fine needle aspiration cytology (FNAC) assisted with scrotal ultrasonography is the best preoperative diagnostic modality for palpable epididymal nodules. It also aids in their successive remedial approach as well as serves semi-therapeutically in cystic lesions. The objectives of this study are to recognize the spectrum of pathological conditions giving rise to epididymal nodules, then to compare them with corresponding ultrasound images, and to evaluate the histological features wherever practicable. METHODS: Total 62 patients underwent FNAC as well as sonographic evaluation for their epididymal nodules. Histopathology was performed in only 20 cases. RESULTS: Epididymitis either caused by tuberculosis (30.6%), or in its acute (11.3%) and chronic (8.1%) forms remained the commonest cytological diagnosis. Neoplastic lesions included mostly adenomatoid tumors (8.1%), and another case of seminomatous spread from ipsilateral testicular primary. Nineteen of the excised masses corroborated with their respective cytodiagnoses. The discrepant lesion was actually a papillary cystadenoma, which was cytologically misinterpreted as adenomatoid tumor. CONCLUSIONS: FNAC becomes the first-hand investigative measure for epididymal nodules, by virtue of its early, easy and highly accurate diagnostic implications. It segregates the patients into proper therapeutic protocol and thereby estranges those who really need operative management. When deployed together with ultrasound, the diagnostic accuracy of FNAC improves further.

A study on the performance of coke resistive cerium modified zeolite Y catalyst for the pyrolysis of scrap tyres in a two-stage fixed bed reactor.

Catalytic pyrolysis is a useful technique for the conversion of scrap tyres into liquid fuels. Zeolite catalysts were employed in the pyrolysis of scrap tyres for the production of aromatic rich fuel. Deactivation of zeolite catalysts during pyrolysis reaction was investigated which played an important role in the product quality and composition. Herein, the performance of microporous zeolite catalysts and mesoporous MCM-41 catalyst was evaluated in a two-stage fixed bed reactor for the pyrolysis of scrap tyres. Comparative studies showed the increase in the production of aromatic compounds up to 23.7% over zeolite catalyst as compared to 18.7% over MCM-41 catalyst. However, Zeolite Y catalyst exhibited higher coke formation led to the rapid deactivation. The stability of zeolite catalysts is addressed by the incorporation of Cerium metal within the framework of two zeolite catalysts namely Zeolite Y and ZSM-5 through the ion-exchange technique. Parent and spent catalysts were characterised using synchrotron FT-IR spectroscopy, temperature-programmed desorption of ammonia (NH3-TPD), N2 Physisorption, scanning electron microscopy (SEM), inductively coupled plasma-optical emission spectrometry (ICP-OES), energy-dispersive X-ray spectroscopy (EDX), and hydrogen temperature-programmed reduction (H2-TPD). A higher percentage of aromatics were produced over the large pore Zeolite Y. Cerium ion-exchange decreased the formation of coke from 8.1% to 5.7% over submicron and large pore Zeolite Y catalyst. Moreover, naphthalene production decreased over both Ce-Zeolite Y and Ce-ZSM-5.

A review on the production of renewable aviation fuels from the gasification of biomass and residual wastes.

This article reviews the production of renewable aviation fuels from biomass and residual wastes using gasification followed by syngas conditioning and Fischer-Tropsch catalytic synthesis. The challenges involved with gasifying wastes are discussed along with a summary of conventional and emerging gasification technologies. The techniques for conditioning syngas including removal of particulate matter, tars, sulphur, carbon dioxide, compounds of nitrogen, chlorine and alkali metals are reported. Recent developments in Fischer-Tropsch synthesis, such as new catalyst formulations are described alongside reactor technologies for producing renewable aviation fuels. The energy efficiency and capital cost of converting biomass and residual wastes to aviation fuels are major barriers to widespread adoption. Therefore, further development of advanced technologies will be critical for the aviation industry to achieve their stated greenhouse gas reduction targets by 2050.

Bandgap Tuning and Blue-Green Band Emissions of Sol-Gel Synthesized ZnO Films by High Cu Doping.

The present research focuses on the preparation of ZnO thin films both undoped and doped with varying Cu concentrations (0.0%, 0.8%, 3.0%, 5.0%, 10.0% and 20.0%) using sol-gel spin coating technique. The optical bandgap (Eg) for undoped films is recorded as 3.239 eV and shows a little increase to 3.248 eV when it is doped with 0.8% Cu concentration whereas further increase of Cu doping concentration, it is decreased from 3.248 eV to 3.107 eV for 20% Cu. The EU (Urbach Energy) is improved with the enhancement of Cu doping concentration. Ultraviolet (UV) and bluegreen band emissions are noticed from PL (photoluminescence) spectra. The UV peak intensities are diminished with increasing Cu doping concentration while the blue peaks intensities are amplified. These results illustrate that ZnO films doped with Cu meet the requirement for applications in different blue emission devices.

Highly sensitive label-free bio-interfacial colorimetric sensor based on silk fibroin-gold nanocomposite for facile detection of chlorpyrifos pesticide.

Herein, the preparation of gold nanoparticles-silk fibroin (SF-AuNPs) dispersion and its label-free colorimetric detection of the organophosphate pesticide, namely chlorpyrifos, at ppb level are reported. The silk fibroin solution was extracted from B. mori silk after performing degumming, dissolving and dialysis steps. This fibroin solution was used for synthesis of gold nanoparticles in-situ without using any external reducing and capping agent. X-ray Diffractometry (XRD), Field Emission Transmission Electron Microscopy (FETEM) along with Surface Plasmon Resonance based optical evaluation confirmed generation of gold nanoparticles within SF matrix. The resultant SF-AuNPs dispersion exhibited rapid and excellent colorimetric pesticide sensing response even at 10 ppb concentration. Effect of additional parameters viz. pH, ionic concentration and interference from other pesticide samples was also studied. Notably, SF-AuNPs dispersion exhibited selective colorimetric pesticide sensing response which can be calibrated. Furthermore, this method was extended to various simulated real life samples such as tap water, soil and agricultural products including plant residues to successfully detect the presence of chlorpyrifos pesticide. The proposed colorimetric sensor system is facile yet effective and can be employed by novice rural population and expert researchers alike. It can be exploited as preliminary tool for label-free colorimetric chlorpyrifos pesticide sensing in water and agricultural products.

Malaria parasite development in a Drosophila model.

Malaria is a devastating public health menace, killing over one million people every year and infecting about half a billion. Here it is shown that the protozoan Plasmodium gallinaceum, a close relative of the human malaria parasite Plasmodium falciparum, can develop in the fruit fly Drosophila melanogaster. Plasmodium gallinaceum ookinetes injected into the fly developed into sporozoites infectious to the vertebrate host with similar kinetics as seen in the mosquito host Aedes aegypti. In the fly, a component of the insect's innate immune system, the macrophage, can destroy Plasmodia. These experiments suggest that Drosophila can be used as a surrogate mosquito for defining the genetic pathways involved in both vector competence and part of the parasite sexual cycle.

Synthesis of 2-(5-((5-(4-chlorophenyl)furan-2-yl)methylene)-4-oxo-2-thioxothiazolidin-3-yl)acetic acid derivatives and evaluation of their cytotoxicity and induction of apoptosis in human leukemia cells.

In order to explore the anticancer effect associated with the thiazolidinone framework, several 2-(5-((5-(4-chlorophenyl)furan-2-yl)methylene)-4-oxo-2-thioxothiazolidin-3-yl)acetic acid derivatives 5(a-l) were synthesized. Variation in the functional group at C-terminal of the thiazolidinone led to set of compounds bearing amide moiety. Their chemical structures were confirmed by (1)H NMR, IR and Mass Spectra analysis. These thiazolidinone compounds containing furan moiety exhibits moderate to strong antiproliferative activity in a cell cycle stage-dependent and dose dependent manner in two different human leukemia cell lines. The importance of the electron donating groups on thiazolidinone moiety was confirmed by MTT and Trypan blue assays and it was concluded that the 4th position of the substituted aryl ring plays a dominant role for its anticancer property. Among the synthesized compounds, 5e and 5f have shown potent anticancer activity on both the cell lines tested. To rationalize the role of electron donating group in the induction of cytotoxicity we have chosen two molecules (5e and 5k) having different electron donating group at different positions. LDH assay, Flow cytometric analysis and DNA fragmentation suggest that 5e is more cytotoxic and able to induce the apoptosis.

Intercalating, cytotoxic, antitumour activity of 8-chloro and 4-morpholinopyrimido [4',5':4,5]thieno(2,3-b)quinolines.

Circular dichroism, hydrodynamic methods, absorbance and fluorescence titration's were employed to study the interaction of 8-chloropyrimido[4',5':4,5]thieno(2,3-b)quinolin-4(3H)-one (chloro-PTQ) and 4-morpholinopyrimido[4',5':4,5]thieno(2,3-b)quinoline (morpholino-PTQ) with DNA. The association constant of chloro-PTQ and morpholino-PTQ were of the order of 10(5) and 10(6) M(-1). The fluorescence properties at ionic strength of 10mM are best fit by the neighbor exclusion model, with Ki of 0.3 x 10(4) M(-1) to 3.2 x 10(6) M(-1). CD spectra indicate that stacking of these compounds with DNA induces strong helicity in the usually disordered structure of the double strand. Viscosity experiments with sonicated rod like DNA fragments, produced a calculated length of 2.4A/bound of chloro/morpholino-PTQ molecule. The binding of chloro/morpholino-PTQ to DNA increased the melting temperature by about 1.5-7.0 degrees C. The cytotoxicity of these compounds on K-562, HL-60, Colo-205 and B16F10 melanoma are quite similar and IC(50) was in the range of 1.1-8muM. The anticancer efficacy against B16F10 melanoma has provided evidence of major anticancer activity for morpholino-PTQ. Single or multiple i.p. doses of compounds showed high level of activity against the subcutaneous (s.c.) grafted B16 melanoma with a significant increase in life span (161% and 272%). The aim of this study was to analyze the physicochemical properties of the chloro/morpholino-PTQ in an attempt to understand their superior biological activity. This research offers a new intercalation functional group to DNA targeted drug design.

Antibacterial Activities of Clove (Syzygium aromaticum) Extracts Against Three Food Borne Pathogens: Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa.

Evaluation of the in vitro antibacterial activity of aqueous and ethanolic extracts isolated from Clove (Syzygium aromaticum) buds against three food borne pathogens, gram-positive Staphylococcus aureus and gram-negative Escherichia coli & Pseudomonas aeruginosa. This interventional study was carried out during the period of July 2018 to June 2019 in the Department of Pharmacology and Therapeutics with the collaboration of Department of Microbiology, Mymensingh Medical College, Mymensingh, Bangladesh. The antibacterial activity was tested at different concentrations of both extracts of spice by using disc diffusion & broth dilution method. The extracts were prepared by using solvents aqueous & ethanol. The test microorganisms were also tested for their activity against a standard antibiotic Gentamicin (80mg) by broth dilution method and the result was compared with that of Aqueous and Ethanolic extracts. Aqueous and ethanolic extracts of clove had inhibitory activity against the test bacteria. Among different concentrations of the ACE, 500µg/ml & above concentration showed inhibitory effect against Staphylococcus aureus & Escherichia coli and 700µg/ml & above concentration showed inhibitory effect against Pseudomonas aeruginosa. In case of ECE, 500µg/ml & above concentration showed inhibitory effect against aforesaid bacteria. In disc diffusion method, S. aureus was found to be most susceptible to ACE (30.5mm) & Pseudomonas aeruginosa was found to be most susceptible to ECE (38mm). Minimum inhibitory concentrations (MIC) of ECE were lower than ACE for the test bacteria except Staphylococcus aureus where MICs of ACE & ECE were the same. This result was also compared against a standard antibiotic Gentamicin where the MICs of Gentamicin were lower in comparison to MICs of ACE & ECE. The present study showed that aqueous and ethanolic extracts of Clove demonstrated antibacterial effects against food borne pathogens.

Genotoxicity of DNA Intercalating Anticancer Drugs: Pyrimido[4(I),5(I):4,5] thieno(2,3-b)quinolines on Somatic and Germinal Cells.

ABSTRACT The genotoxic effect of the anticancer drugs Oxo-PTQ, Morpholino-PTQ, and Chloro-PTQ were studied in mice bone marrow by means of chromosome aberrations and micronucleus assay. These drugs, at dose levels of 21.42, 28.57, and 35.71 mg/kg b.w., respectively, were given to mice in a single application via the intraperitoneal route. Marrow was collected at 24, 48, and 72 h after the application. The chromosome aberrations and micronucleus assay were done according to standard procedures. These compounds gave rise to an increase in the number of micronuclei in a dose-dependent manner. The number of micronucleated polychromatic erythrocytes showed a maximum at 24 h, and there was partial recovery at 72 h. Chromosome aberrations increased significantly as compared to normal controls when treated with Oxo-PTQ followed by Morpholino-PTQ at 21.42 mg/kg b.w. (48 h). Statistically significant sperm abnormalities also revealed the genotoxic potency of these drugs. Our results suggest that the Pyrimido[4(I),5(I):4,5]thieno(2,3-b)quinoline drugs owe at least some of their cytotoxicity to their genotoxic effects, which seem to be mediated through interaction with topoisomerase II.

A novel glucose-6-phosphate dehydrogenase in Plasmodium falciparum: cDNA and primary protein structure.

The structure of the parasite-encoded G6PD (PfG6PD) may provide clues about the relative protection against malaria in humans with glucose-6-phosphate dehydrogenase (G6PD) deficiency. We have cloned Pfg6pd cDNA encoding a predicted 856 amino acid residues polypeptide with a calculated molecular mass of > 94 kDa. The predicted amino acid sequence is highly homologous to G6PD from other organisms. Pfg6pd maps as a single or low copy number gene to chromosome 14. The unusually large N-terminus and the distance between the NADP-binding site and G6PD-binding site is novel for the parasite G6PD. The differences between parasite and human G6PD proteins could potentially be exploited for designing new chemotherapeutic agents.

Uniform detection of HIV-1 in alveolar macrophages of pediatric but not adult AIDS patients.

Manifestations of pulmonary disease in pediatric AIDS patients differ from those in adults. To evaluate whether differences in the frequency of alveolar macrophage (AM) infection with human immunodeficiency virus type 1 (HIV-1) could account for these clinical distinctions, we undertook a comparative analysis of HIV-1 DNA in AMs from pediatric and adult AIDS patients by enzymatic amplification. A higher frequency of viral DNA detection in pediatric cases (100%) compared with adults (67%) was observed. The sensitivity of detection was 1 viral DNA copy per 4000 AMs; matched peripheral blood mononuclear cells from six of seven pediatric and eight of nine adult patients tested HIV-1 DNA positive. Adult but not pediatric patients exhibited a marked alveolar lymphocytosis, 32% mean lymphocyte count compared with 7.0%, respectively. These results suggest that the burden of HIV-1 in the lungs of pediatric AIDS patients is greater than that in adults.

Laser induced infrared spectral shift of the MgB2:Cr superconductor films.

During illumination of the MgB2:Cr2O3 films it was established substantial spectral shift of the infrared spectra in the vicinity of 20-50cm(-1). The excitations were performed by nanosecond Er:glass laser operating at 1.54µm and by microsecond 10.6µm CO2 laser. The spectral shifts of the IR maxima were in opposite spectral directions for the two types of lasers. This one observed difference correlates well with spectral shift of their critical temperatures. The possible explanation is given by performance of DFT calculations of the charge density redistribution and the time kinetics of the photovoltaic response. To understand the kinetics of the photoinduced processes the time kinetics of photoresponse was done for the particular laser wavelengths.

The gene for hypoxanthine phosphoribosyl transferase of Plasmodium falciparum complements a bacterial HPT mutation.

The enzyme hypoxanthine phosphoribosyl transferase of Plasmodium falciparum has been overexpressed in Escherichia coli. The protein was found to be active enzymatically. When the recombinant expression vector (pPfPRT2) was transformed and expressed in a Salmonella typhimurium mutant KP1684 (purE deoD hpt gpt), the active expressed protein complemented the hpt mutation in the bacteria. We discuss the practical value of this strain. Assays of the expressed protein in the mutant extract showed that the enzyme is able to use hypoxanthine, guanine and xanthine as substrates. A specificity study using the competitive inhibitor, 6-thioguanine, showed that of these hypoxanthine is the most favourable substrate. The biological significance of xanthine utilisation by the enzyme is discussed.