Hidden risk of terrestrial food chain contamination from organochlorine insecticides in a vegetable cultivation area of Northwest Bangladesh.

Organochlorine insecticide (OCI) exposures in terrestrial food chains from historical or current applications were studied in a vegetable production area in northwest Bangladesh. A total of 57 subsoil, 57 topsoil, and 57 vegetable samples, as well as 30 cow's milk samples, were collected from 57 farms. Multiple OCI residues were detected using GC-MS/MS with modified QuEChERS in 20 % of subsoils, 21 % of topsoils, 23 % of vegetables, and 7 % of cow's milk samples. Diversified OCI residues were detected in subsoils (17 residues with a concentration of 179.15 ± 148.61 µg kg-1) rather than in topsoils (3 DDT residues with a concentration of 25.76 ± 20.19 µg kg-1). Isomeric ratios indicate intensive historical applications of OCIs. According to Dutch and Chinese standards, the lower concentrations of individual OCI residues in the soil indicate negligible to slight soil pollution, assuming local farmers follow local pesticide use regulations. However, a maximum of 78.24 µg kg-1 ΣAldrines and 35.57 µg kg-1 ΣHCHs were detected (1-4 residues) in 60 % of brinjal, 28 % of cucumber, 29 % of sponge gourd, and 20 % of lady's finger samples, which could be a result of either historical or current OCI applications, or both. A strong positive correlation between aldrines in subsoils and cucurbit vegetables indicates greater bioaccumulation. Cow milk samples contained up to 6.96 µg kg-1 ΣDDTs, which resulted either from rationing contaminated vegetables or grazing on contaminated land. Individual OCI in both vegetables and cow's milk was below the respective maximum residue limits of US and FAO/WHO CODEX and poses little or no risk to human health. However, combined exposure to multiple pesticides could increase human health risks. A cumulative health risk assessment of multiple pesticide residues is suggested to assess the suitability of those soils for cultivation and grazing, as well as the safety of vegetables and cow's milk for human consumption.

Cardioprotection of Water Spinach (Ipomoea aquatica), Wood Apple (Limonia acidissima) and Linseed (Linum usitatissimum L.) on Doxorubicin-Induced Cardiotoxicity and Oxidative Stress in Rat Model.

Objectives: The aim of this study was to investigate the pharmacological efficacy of 3 functional foods (Water spinach, Wood apple, and Linseed) against doxorubicin-induced cardiotoxicity and oxidative stress in rat models. Methods: Twenty-five Wistar Albino rats (male and female) were equally classified into 5 groups. Except for the normal control (NC) group, the animals received 2.5 mg/kg doxorubicin (DOX) intra-peritoneal injection at 48 hours intervals to create a dose of 15 mg/kg overall for 14 days. Simply a standard diet was given to the NC and DOX groups. In the 3 treatment groups such as water spinach (DOX + WS), wood apple (DOX + WA), and linseed (DOX + LS), rats were given 14 gm/day/rat fried water spinach, mashed wood apple, roasted linseed, respectively mixed with regular rat diet at 1:1 ratio. Blood and heart samples were collected by sacrificing all the rats on the last of the experiment day (the 15th day). LDH (lactate dehydrogenase), CK-MB (creatine kinase myocardial band), MDA (malondialdehyde), and SOD (superoxide dismutase) were analyzed. Additionally, histopathological analysis was conducted for final observation. Results: The functional foods were indicated to lower the serum cardiac biomarkers (LDH and CK-MB) as well as stress marker (MDA) significantly (P < .05) and improved heart function and oxidative stress. However, the change in serum SOD level was noted as statistically insignificant (P > .05). The biochemical outcomes of the food intervention groups were supported by the histological findings found in those groups. Conclusion: Consuming the investigated foods containing antioxidant phytochemicals may combat cardiac toxicity and oxidative stress. Nonetheless, thorough investigations and clinical monitoring are required to understand these functional foods' mechanism of action and dose-response effects in treating cardiotoxicity and oxidative stress.

A simple, inexpensive and portable on-farm test for pregnancy diagnosis and ovary status in cows via chemical analysis of urine.

Ovary dysfunction causes an aberrant endocrine surge at various reproductive cycle stages, negatively impacting fertility and economic profit. Optimizing dairy cow performance requires determining ovarian status and detecting early pregnancy. Still, little to no information is available about the diagnosis of the ovarian condition using urine chemical analysis at the field level in Bangladesh. This study aimed to develop a simple, inexpensive and portable on-farm technique for pregnancy diagnosis and ovary status determination in cows via chemical urine analysis. Fifty reproductively healthy cows were recruited from different donor farms. Prior to artificial insemination (AI), all selected cows were placed in a single ovsynch program. TAI (timed artificial insemination) was carried out. Urine was routinely collected from Day 0-55 days at estrus cycle stages for routine chemical analysis using barium chloride (BaCl2), followed by commercially available protein strip tests. The developed techniques for pregnancy and ovary status diagnosis in cows were validated with rectal palpation (RP). Barium chloride (BaCl2) analysis of urine revealed white precipitation corresponding to a mature follicle in the ovary during estrus and colorless precipitation corresponding to the corpus luteum during the diestrus period. Positive pregnancy was indicated by the presence of a colorless precipitate in the BaCl2 test, and a protein value of less than 100 mg/dl was found in the protein strip test. The maximum accuracy (42/50, 84%) was observed between 25 and 35 days, as confirmed by RP. Perplexing results were seen 45-55 days after AI, between pregnancies and luteal cystic disease. In both cases, we discovered that the BaCl2 precipitation was colorless. However, the protein value in the context of luteal cystic disease was found to be higher than 100 mg/dl. The barium chloride test, followed by protein strip tests, is a simple and portable way to diagnose pregnancy and determine ovarian status in cows at the field level.

Hydrophilic ionic liquid assisted hydrothermal synthesis of ZnO nanostructures with controllable morphology.

Nanostructured ZnO with controllable morphology was prepared by a hydrothermal method in the presence of three different hydrophilic ionic liquids (ILs), 1-ethyl-3-methylimidazolium methylsulfate, ([C2mim]CH3SO4), 1-butyl-3-methylimidazolium methylsulfate, ([C4mim]CH3SO4) and 1-ethyl-3-methylimidazolium ethylsulfate, ([C2mim]C2H5SO4) as soft templates. The formation of ZnO nanoparticles (NPs) with and without IL was verified using FT-IR and UV-visible spectroscopy. X-ray diffraction (XRD) and selected area electron diffraction (SAED) patterns indicated the formation of pure crystalline ZnO with a hexagonal wurtzite phase. Field emission scanning electron microscopic (FESEM) and high-resolution transmission electron microscopic (HRTEM) images confirmed the formation of rod-shaped ZnO nanostructures without using IL, whereas the morphology varied widely following addition of ILs. With increasing concentrations of [C2mim]CH3SO4, the rod-shaped ZnO nanostructures transformed into flower-shaped nanostructures whereas with rising concentrations of [C4mim]CH3SO4 and [C2mim]C2H5SO4 the morphology changed into petal- and flake-like nanostructures, respectively. The selective adsorption effect of the ILs could protect certain facets during the formation of ZnO rods and promote the growth in directions other than [0001] to yield petal- or flake-like architectures. The morphology of ZnO nanostructures was, therefore, tunable by the controlled addition of hydrophilic ILs of different structures. The size of the nanostructures was widely distributed and the Z-average diameter, evaluated from dynamic light scattering measurements, increased as the concentration of the IL increased and passed through a maximum before decreasing again. The optical band gap energy of the ZnO nanostructures decreased when IL was added during the synthesis which is consistent with the morphology of the ZnO nanostructures. Thus, the hydrophilic ILs serve as self-directing agents and soft templates for the synthesis of ZnO nanostructures and the morphology and optical properties of ZnO nanostructures are tunable by changing the structure of the ILs as well as systematic variation of the concentration of ILs during synthesis.

Purification of Tubulin from Porcine Brain and its Fluorescence Dye Modification.

Filamentous microtubules, polymers of the heterodimeric protein tubulins play one of the major roles in the emergent nano-biotechnological devices. To develop the feature of those devices, it is important to understand the function of microtubule in in vitro, hence, the availability of purified αß-tubulin is required. Additionally, fluorescently labeled tubulin has become a powerful approach for extensively studying the dynamics of these components. In this chapter, the process of purifying the heterodimeric αß-tubulin from porcine brain will be described, as well as the process of labeling of the purified tubulin with fluorescence dye.

Functionalization of Tubulin: Approaches to Modify Tubulin with Biotin and DNA.

The filamentous cytoskeletal protein microtubule, a polymer of α and ß heterodimers of tubulin, plays major roles in intracellular transport as well as in vitro molecular actuation and transportation. Functionalization of tubulin dimers through covalent linkage facilitates utilization of microtubule in the nanobioengineering. Here we present a detailed description of the methodologies used to modify tubulin dimers with DNA strand and biotin through covalent interaction.

Dynamic Pattern Formation of Active Matters Triggered by Mechanical Stimuli.

In vitro gliding assay of the filamentous protein microtubule (MT) on a kinesin motor protein coated surface has appeared as a classic platform for studying active matters. At high densities, the gliding MTs spontaneously align and self-organize into fascinating large-scale patterns. Application of mechanical stimuli e.g., stretching stimuli to the MTs gliding on a kinesin-coated surface can modulate their self-organization and patterns according to the boundary conditions. Depending on the mode of stretching, MT at high densities change their moving direction and exhibit various kinds of patterns such as stream, zigzag and vortex pattern. In this chapter, we discuss detail procedures on how to apply mechanical stimuli to the moving MTs on a kinesin coated substrate.

Fabrication of Artificial Muscle from Microtubules, Kinesins, and DNA Origami Nanostructures.

Fabrication of molecular devices using biomolecules through biomimetic approaches has witnessed a surge in interest in recent years. DNA a versatile programmable material offers an opportunity to realize complicated operations through the designing of various nanostructures such as DNA origami. Here we describe the methods to use DNA origami for the self-assembly of the biomolecular motor system, microtubule (MT)-kinesin. A rodlike DNA origami motif facilitates the self-assembly of MTs into asters. A smooth muscle like molecular contraction system could be realized following the method where DNA mediated self-assembly of MTs permits dynamic contraction in the presence of kinesins through an energy dissipative process.

Construction of Molecular Robots from Microtubules for Programmable Swarming.

Swarm robotics has been attracting much attention in recent years in the field of robotics. This chapter describes a methodology for the construction of molecular swarm robots through precise control of active self-assembly of microtubules (MTs). Detailed protocols are presented for the construction of molecular robots through conjugation of DNA to MTs and demonstration of swarming of the MTs. The swarming is mediated by DNA-based interaction and photoirradiation which act as processors and sensors respectively for the robots. Furthermore, the required protocols to utilize the swarming of MTs for molecular computation is also described.

Photo-regulated trajectories of gliding microtubules conjugated with DNA.

We regulate the persistency in motion of kinesin-driven microtubules (MTs) simply using a photoresponsive DNA (pDNA) and ultraviolet (UV)-visible light. The path persistence length of MTs, which is a measure of the persistency in their motion, increases and decreases upon illuminating the MTs with UV and visible light respectively. Moreover, pDNA is found to work as a shield for MTs against damage under UV irradiation.

Role of MicroRNA Genes miR-1000 and miR-375 in Forming Olfactory Conditional Memory in Drosophila melanogaster.

BACKGROUND: Learning and memory are basic aspects of neurogenetics as most of the neurological disorders start with dementia or memory loss. Several genes associated with memory formation have been discovered. MicroRNA genes, miR-1000 and miR-375, were reported to be associated with neural integration and glucose homeostasis in some insects and vertebrates. However, the neuronal function of these genes is yet to be established in D. melanogaster. OBJECTIVE: The possible role of miR-1000 and miR-375 in learning and memory formation in this fly has been explored in the present study. METHODS: Both types of appetitive and aversive olfactory conditional learning were tested in the miR- 1000 and miR-375 knockout (KO) strains and compared with the wild one. Five days old third instar larvae were trained by allowing them to be associated with an odor with reward (fructose) or punishment (salt). Then, the larvae were tested to calculate their preferences to the odor they were trained with. Learning Index (LI) values and larval locomotion speed were calculated for all strains. RESULTS: Knockout strain of miR-1000 showed significant deficiency in both appetitive and aversive memory formation whereas miR-375 KO strain showed a significantly lower response only in appetitive one. CONCLUSION: The results of the present study indicate an important role of miR-1000 and miR-375 genes in forming short-term memory in D. melanogaster.