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1.
Chemphyschem ; : e202400235, 2024 May 28.
Article in English | MEDLINE | ID: mdl-38807431

ABSTRACT

The cooperative mechanism is of paramount importance in the synthesis of supramolecular polymers with desired characteristics, including molecular mass, polydispersity, and morphology. It is primarily driven by the presence of intermolecular interactions, which encompass strong hydrogen bonding, metal-ligand interactions, and dipole-dipole interactions. In this study, we utilize density functional theory and energy decomposition analysis to investigate the cooperative behavior of perylene diimide (PDI) oligomers with alkyl chains at their imide positions, which lack the previously mentioned interactions. Our systematic examination reveals that dispersion interactions originating from the alkyl side-chain substituents play an important role in promoting cooperativity within these PDIs. This influence becomes even more pronounced for alkyl chain lengths beyond hexyl groups. The energy decomposition analysis reveals that the delicate balance between dispersion energy and Pauli repulsion energy is the key driver of cooperative behavior in PDIs. Additionally, we have developed a mathematical model capable of predicting the saturated binding energies for PDI oligomers of varying sizes and alkyl chain lengths. Overall, our findings emphasize the previously undervalued significance of dispersion forces in cooperative supramolecular polymerization, enhancing our overall understanding of the cooperative mechanism.

2.
J Appl Microbiol ; 135(3)2024 Mar 01.
Article in English | MEDLINE | ID: mdl-38467390

ABSTRACT

AIMS: To identify a marine L-asparaginase with clinically desirable attributes and characterize the shortlisted candidate through in silico tools. METHODS AND RESULTS: Marine bacterial strains (number = 105) isolated from marine crabs were evaluated through a stepwise strategy incorporating the crucial attributes for therapeutic safety. The results demonstrated the potential of eight bacterial species for extracellular L-asparaginase production. However, only one isolate (Bacillus altitudinis CMFRI/Bal-2) showed clinically desirable attributes, viz. extracellular production, type-II nature, lack of concurrent L-glutaminase and urease activities, and presence of ansZ (functional gene for clinical type). The enzyme production was 22.55 ± 0.5 µM/mg protein/min within 24 h without optimization. The enzyme also showed good activity and stability in pH 7-8 and temperature 37°C, predicting the functioning inside the human body. The Michealis-Menten constant (Km) was 14.75 µM. Detailed in silico analysis based on functional gene authenticating the results of in vitro characterization and predicted the nonallergenic characteristic of the candidate. Docking results proved the higher affinity of the shortlisted candidate to L-asparagine than L-glutamine and urea. CONCLUSION: Comprehensively, the study highlighted B. altitudinis type II asparaginase as a competent candidate for further research on clinically safe asparaginases.


Subject(s)
Asparaginase , Bacillus , Humans , Asparaginase/genetics , Bacillus/genetics , Asparagine , Temperature
3.
Curr Microbiol ; 81(7): 174, 2024 May 16.
Article in English | MEDLINE | ID: mdl-38753164

ABSTRACT

The Oscar fish (Astronotus ocellatus) is among the most commonly domesticated and exported ornamental fish species from Kerala. The ornamental fish industry faces a significant challenge with the emergence of diseases caused by multi-drug-resistant bacteria. In the present study, six isolates were resolved from the diseased Oscar fish showing haemorrhages, necrosis, and loss of pigmentation. After phenotypic and genotypic characterization, the bacteria were identified as Edwardsiella tarda, Klebsiella pneumoniae, Enterococcus faecalis, Escherichia coli, Brevibacillus borstelensis, and Staphylococcus hominis. Experimental challenge studies in healthy Oscar fish showed that E. tarda caused 100% mortality within 240 h with 6.99 × 106 CFU/fish as LD50 and histopathology revealed the typical signs of infection. The pathogen was re-recovered from the moribund fish thereby confirming Koch's postulates. E. tarda was confirmed through the positive amplification of tarda-specific gene and virulence genes viz., etfD and escB were also detected using PCR. Antibiotic susceptibility tests using disc diffusion displayed that the pathogen is multi-drug-resistant towards antibiotics belonging to aminoglycosides, tetracyclines, and quinolones categories with a MAR index of 0.32, which implicated the antibiotic pressure in the farm. Plasmid curing studies showed a paradigm shift in the resistance pattern with MAR index of 0.04, highlighting the resistance genes are plasmid-borne except for the chromosome-borne tetracycline resistance gene (tetA). This study is the first of its kind in detecting mass mortality caused by E. tarda in Oscar fish. Vigilant surveillance and strategic actions are crucial for the precise detection of pathogens and AMR in aquaculture.


Subject(s)
Anti-Bacterial Agents , Drug Resistance, Multiple, Bacterial , Edwardsiella tarda , Enterobacteriaceae Infections , Fish Diseases , Microbial Sensitivity Tests , Animals , Fish Diseases/microbiology , Fish Diseases/mortality , Edwardsiella tarda/genetics , Edwardsiella tarda/pathogenicity , Edwardsiella tarda/isolation & purification , Edwardsiella tarda/drug effects , Enterobacteriaceae Infections/microbiology , Enterobacteriaceae Infections/veterinary , Enterobacteriaceae Infections/mortality , Drug Resistance, Multiple, Bacterial/genetics , Anti-Bacterial Agents/pharmacology , Fishes/microbiology , Virulence/genetics , Virulence Factors/genetics
4.
Fish Physiol Biochem ; 50(2): 557-574, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38193995

ABSTRACT

Research on antioxidant biomarkers can generate profound insights into the defense mechanisms of fish larvae against different stressors and can reveal manipulation strategies for improved growth and survival. However, the number of samples to process and unavailability of required infrastructure in larval-rearing facilities limit the immediate processing, requiring the preservation of specimens. Silver pompano (Trachinotus blochii), a potential marine aquaculture species, shows a low larval survival rate due to poorly developed antioxidant mechanism. In this context, 39 storage conditions, including three storage temperatures and different buffers, were scrutinized to select the most suitable preservation strategy for five important antioxidant biomarkers of fish larvae, viz. catalase activity, superoxide dismutase (SOD) activity, measurement of lipid peroxidation, reduced glutathione (GSH), and ascorbic acid contents. The paper proposes the optimum larval storage conditions for these five evaluated antioxidant biomarkers to generate similar results in preserved and non-preserved larval samples. Larval samples preserved in PBS at lower temperatures (- 20 °C and - 80 °C) are recommended for evaluating catalase activity and ascorbic acid content. Catalase activity can also be evaluated by preserving the larval samples at - 20 °C or - 80 °C without buffers. Larval samples held in PBS or without any buffers at - 20 °C and at - 80 °C were found to be suitable for SOD and GSH evaluation, respectively. Preservation in 50% glacial acetic acid at - 80 °C or - 20 °C was preferred for the lipid peroxidation assays. Apart from methodological perspectives, the paper provides insights into the dynamics of larval antioxidant profiles of T. blochii, for the first time.


Subject(s)
Antioxidants , Superoxide Dismutase , Animals , Antioxidants/metabolism , Catalase/metabolism , Larva/metabolism , Superoxide Dismutase/metabolism , Ascorbic Acid , Glutathione , Fishes/metabolism , Biomarkers/metabolism , Lipid Peroxidation , Oxidative Stress
5.
Angew Chem Int Ed Engl ; 63(27): e202403229, 2024 Jul 01.
Article in English | MEDLINE | ID: mdl-38577991

ABSTRACT

We present a catalyst-free route for the reduction of carbon dioxide integrated with the formation of a carbon-carbon bond at the air/water interface of negatively charged aqueous microdroplets, at ambient temperature. The reactions proceed through carbanion generation at the α-carbon of a ketone followed by nucleophilic addition to CO2. Online mass spectrometry reveals that the product is an α-ketoacid. Several factors, such as the concentration of the reagents, pressure of CO2 gas, and distance traveled by the droplets, control the kinetics of the reaction. Theoretical calculations suggest that water in the microdroplets facilitates this unusual chemistry. Furthermore, such a microdroplet strategy has been extended to seven different ketones. This work demonstrates a green pathway for the reduction of CO2 to useful carboxylated organic products.

6.
Phys Chem Chem Phys ; 25(16): 11789-11804, 2023 Apr 26.
Article in English | MEDLINE | ID: mdl-37067357

ABSTRACT

There is continuous demand for energy storage devices with high energy densities in consumer electronics, electric vehicles, and the grid energy market. Although commercial lithium-ion batteries (LIBs) satisfy the current needs, the limited availability of their raw materials and the moderate specific charge capacities (SCCs) of LIBS have motivated scientists to search for alternate anode materials for LIBs and create technologies beyond LIBs. In this work, we studied the potential of six cobalt anti-MXenes (CoAs, CoB, CoP, CoS, CoSe, and CoSi), a class of newly discovered 2D materials, as anode materials for lithium, sodium, and potassium ion batteries (LIBs, NIBs, and KIBs). We found that these materials are good electrical conductors and have high adsorption stability for alkali metal ions, which helps to prevent the formation of dendrites and increase the cycle life of the battery. They also show moderate to low migration energy barriers (MEBs), indicating the potential for faster charge-discharge kinetics. We also explain the slightly counter-intuitive result of observing low MEBs along with high adsorption stability. Furthermore, Co-anti-MXenes can adsorb multiple alkali atoms per formula unit, resulting in high specific charge capacities and low average anodic voltages. For example, as anode materials for lithium-ion batteries, CoP and CoSi have SCC values of 1075.4 mA h g-1 and 934 mA h g-1, and anodic voltages as low as 0.28 V and 0.43 V, respectively. Moreover, even the maximally metalated Co-anti-MXenes did not show agglomeration tendency at room temperature. Furthermore, the volume expansion of these materials is minimum for both Li and Na adsorption. As a whole, we find that Co-anti-MXenes are promising as anode materials for alkali metal ion batteries.

7.
Fish Physiol Biochem ; 49(2): 307-320, 2023 Apr.
Article in English | MEDLINE | ID: mdl-36949263

ABSTRACT

The present study reports the comparative pharmacokinetic profiles of florfenicol and its metabolite (florfenicol amine, FFA) in Trachinotus blochii under tropical marine conditions (salinity: 35 ± 1.4‰; temperature: 28.8 ± 0.54 °C) following a single in-feed oral administration of the recommended dose (15 mg/Kg). Furthermore, the study investigated the distribution of these two compounds in nine different tissues. The maximum florfenicol concentrations (Cmax) in plasma and tissues were observed within five hours (Tmax), except for bile. The Cmax ranged from 572 to 1954 ng/g or ml and was in the intestine > bile > muscle + skin > liver > gill = heart > plasma > kidney = spleen. The elimination half-life of FFC was significantly slower in the bile (38.25 ± 4.46 h). The AUC tissue/plasma was highest for bile (3.77 ± 0.22), followed by intestine > muscle + skin > heart > liver > kidney = gill = spleen. Tmax and t1/2ß were slower, and Cmax was lower for FFA than florfenicol in all tissues except Cmax of the kidney and bile. FFA t1/2ß was exceptionally slower in the kidney (46.01 ± 8.2 h). Interestingly, reaching an apparent distribution rate of > 0.5 was comparatively faster in the kidney, liver, and gills than in other tissues. The highest apparent metabolic rate was in the kidney (0.95 ± 0.01) and the lowest in plasma (0.41 ± 0.01). The generated data can be applied for formulating efficient therapeutic protocols in T. blochii, a promising mariculture species.


Subject(s)
Anti-Bacterial Agents , Fishes , Animals , Tissue Distribution , Administration, Oral , Half-Life
8.
Environ Sci Technol ; 56(12): 8167-8175, 2022 06 21.
Article in English | MEDLINE | ID: mdl-35481774

ABSTRACT

Per- and polyfluoroalkyl substances (PFASs) are synthetic contaminants found in drinking groundwater sources and a wide variety of consumer products. Because of their adverse environmental and human health effects, remediation of these persistent compounds has attracted significant recent attention. To gain mechanistic insight into their remediation, we present the first ab initio study of PFAS degradation via hydrated electrons─a configuration that has not been correctly considered in previous computational studies up to this point. To capture these complex dynamical effects, we harness ab initio molecular dynamics (AIMD) simulations to probe the reactivities of perfluorooctanoic (PFOA) and perfluorooctane sulfonic acid (PFOS) with hydrated electrons in explicit water. We complement our AIMD calculations with advanced metadynamics sampling techniques to compute free energy profiles and detailed statistical analyses of PFOA/PFOS dynamics. Although our calculations show that the activation barrier for C-F bond dissociation in PFOS is three times larger than that in PFOA, all the computed free energy barriers are still relatively low, resulting in a diffusion-limited process. We discuss our results in the context of recent studies on PFAS degradation with hydrated electrons to give insight into the most efficient remediation strategies for these contaminants. Most importantly, we show that the degradation of PFASs with hydrated electrons is markedly different from that with excess electrons/charges, a common (but largely incomplete) approach used in several earlier computational studies.


Subject(s)
Alkanesulfonic Acids , Fluorocarbons , Groundwater , Water Pollutants, Chemical , Electrons , Fluorocarbons/analysis , Humans , Water , Water Pollutants, Chemical/analysis
9.
Appl Microbiol Biotechnol ; 106(12): 4719-4735, 2022 Jun.
Article in English | MEDLINE | ID: mdl-35739345

ABSTRACT

Applications of microbiome research through metagenomics promise to generate microbiome manipulation strategies for improved larval survival in aquaculture. However, existing lacunae on the effects of sample preservation methods in metagenome profiles hinder the successful application of this technique. In this context, four preservation methods were scrutinized to identify reliable methods for fish larval microbiome research. The results showed that a total of ten metagenomics metrics, including DNA yield, taxonomic and functional microbiome profiles, and diversity measures, were significantly (P < 0.05) influenced by the preservation method. Activity ranking based on the performance and reproducibility showed that three methods, namely immediate direct freezing, room temperature preservation in absolute ethanol, and preservation at - 20 °C in lysis, storage, and transportation buffer, could be recommended for larval microbiome research. Furthermore, as there was an apparent deviation of the microbiome profiles of ethanol preserved samples at room temperature, the other methods are preferred. Detailed analysis showed that this deviation was due to the bias towards Vibrionales and Rhodobacterales. The microbial taxa responsible for the dissimilarity across different methods were identified. Altogether, the paper sheds light on the preservation protocols of fish larval microbiome research for the first time. The results can help in cross-comparison of future and past larval microbiome studies. Furthermore, this is the first report on the activity ranking of preservation methods based on metagenomics metrics. Apart from methodological perspectives, the paper provides for the first time certain insights into larval microbial profiles of Rachycentron canadum, a potential marine aquaculture species. KEY POINTS: • First report on effects of preservation methods on fish larval microbiome profiles. • First report on activity ranking of preservation methods based on metagenomics metrics. • Storage methods influenced DNA yield, taxonomic and functional microbiome profiles.


Subject(s)
Metagenomics , Microbiota , Animals , Ethanol , Fishes , Larva , Metagenome , Metagenomics/methods , Microbiota/genetics , Reproducibility of Results
10.
J Phys Chem A ; 125(2): 628-635, 2021 Jan 21.
Article in English | MEDLINE | ID: mdl-33432807

ABSTRACT

We apply direct nonadiabatic dynamics simulations to investigate photoinduced charge transfer reactions. Our approach is based on the mixed quantum-classical fewest switches surface hopping (FSSH) method that treats the transferring electron through time-dependent density functional theory and the nuclei classically. The photoinduced excited state is modeled as a transferring single-electron that initially occupies the LUMO of the donor molecule/moiety. This single-particle electronic wave function is then propagated quantum mechanically by solving the time-dependent Schrödinger equation in the basis of the instantaneous molecular orbitals (MOs) of the entire system. The nonadiabatic transitions among electronic states are modeled using the FSSH approach within the classical-path approximation. We apply this approach to simulate the photoinduced charge transfer dynamics in a few well-characterized molecular systems. Our results are in excellent agreement with both the experimental measurements and high-level (yet expensive) theoretical results.

11.
Parasitol Res ; 120(7): 2505-2521, 2021 Jul.
Article in English | MEDLINE | ID: mdl-34170388

ABSTRACT

The present paper describes Filisoma argusum n. sp. (Cavisomatidae), an acanthocephalan parasite infecting the intestine of the spotted scat, Scatophagus argus (Linnaeus, 1766), in the south-west coast of India. The prevalence is 18% (mean intensity: 1.61 and abundance: 1-4 worms/host). Filisoma argusum n. sp. is morphologically characterized by a creamy-white, cylindrical, elongate, aspinose, and robust trunk; a collar-like neck; and a cylindrical proboscis with 18-20 longitudinal rows of hooks, with 19-22 hooks/row. Proboscis receptacle long, double-walled. Lemnisci digitiform, equal, longer than proboscis receptacle. Females 79.14 ± 33.69 × 0.593 ± 0.19 mm; males 32.62 ± 2.98 × 0.46 ± 0.071 mm. Males with four cement glands; bulbous muscular copulatory bursa with six digitiform rays. SEM studies revealed smooth hooks, sensory pits, and epidermal micropores. Histopathological changes at the site of parasite attachment included inflammation, hemorrhage, sloughing of epithelium, and detachment of mucosal layer of the intestine. In molecular and phylogenetic analyses, the parasite occupied an independent position within the Cavisomatidae clade with high bootstrap values for both ITS1-5.8S and ITS2, and mt-CO1 regions. Considering the morphologic and morphometric differences with previously described species of Filisoma along with its phylogenetic positioning, the present acanthocephalan is treated as a new species and the name Filisoma argusum n. sp. is proposed.


Subject(s)
Acanthocephala/classification , Fishes/parasitology , Acanthocephala/anatomy & histology , Acanthocephala/genetics , Animals , DNA, Mitochondrial/genetics , DNA, Ribosomal/genetics , Female , Fish Diseases/epidemiology , Fish Diseases/parasitology , Helminthiasis, Animal/epidemiology , Helminthiasis, Animal/parasitology , India , Intestines/parasitology , Male , Phylogeny , Species Specificity
12.
Phys Chem Chem Phys ; 22(13): 6804-6808, 2020 Apr 07.
Article in English | MEDLINE | ID: mdl-31989122

ABSTRACT

Per- and polyfluoroalkyl substances (PFASs) are synthetic chemicals that are harmful to both the environment and human health. Using self-interaction-corrected Born-Oppenheimer molecular dynamics simulations, we provide the first real-time assessment of PFAS degradation in the presence of excess electrons. In particular, we show that the initial phase of the degradation involves the transformation of an alkane-type C-C bond into an alkene-type C[double bond, length as m-dash]C bond in the PFAS molecule, which is initiated by the trans elimination of fluorine atoms bonded to these adjacent carbon atoms.

13.
Dis Aquat Organ ; 139: 1-13, 2020 Apr 30.
Article in English | MEDLINE | ID: mdl-32270765

ABSTRACT

Epizootic ulcerative syndrome (EUS), primarily caused by the water mold Aphanomyces invadans, is an OIE-notifiable disease, having potential impacts on fisheries. We report EUS epizootics among estuarine fishes of Kerala, India, during 2018, under post-flood conditions 3 decades after its primary outbreak. Six fish species (Mugil cephalus, Platycephalus sp., Scatophagus argus, Arius sp., Planiliza macrolepis and Epinephelus malabaricus) were infected, including the first confirmed natural case in E. malabaricus and P. macrolepis. Salinity, surface temperature, dissolved oxygen and pH of resident water during the epizootic were <2 ppt, 25°C, 4.1 ppm and 7.0. The presence of zoonotic bacterial pathogens (Aeromonas veronii, Shewanella putrefaciens, Vibrio vulnificus and V. parahaemolyticus) in tissues of affected fish indicates that EUS-infected fish may pose a public health hazard if not handled properly. Lack of clinical evidence in the region during the last 3 decades, a high number of affected fishes, including 2 new fish species, the severity of skin lesions and very low water salinity (<2 ppt) during the outbreak in contrast to historical water salinity records suggest relatively recent invasion by A. invadans. Phylogenetic analysis based on the internal transcribed spacer region of the rRNA gene showed that the same clone of pathogen has spread across different continents regardless of fish species and ecotypes (fresh/estuarine environments). Altogether, the present study provides baseline data which can be applied in EUS management strategies within brackish-water ecosystems. We recommend strict surveillance and development of sound biosecurity measures against the disease.


Subject(s)
Floods , Animals , Ecosystem , Fish Diseases , Fishes , India , Phylogeny
14.
J Food Sci Technol ; 57(7): 2534-2544, 2020 Jul.
Article in English | MEDLINE | ID: mdl-32549604

ABSTRACT

Different doses of gamma Irradiation (0 Gy, 10 Gy, 60 Gy, 100 Gy and 200 Gy) were evaluated as potential treatment to extend the storage period and maintain the quality attributes of onion bulbs (cv. Punjab Noraya) at ambient temperature for a period of 144 days. It was observed that storage parameters such as physiological loss in weight, sprouting percentage, rotting percentage and quality traits like total soluble solids, firmness, color parameters, ascorbic acid and pyruvic acid varied significantly (p < 0.05) during storage period with respect to doses of irradiation. No rotting and sprouting were observed upto 24 days and 84 days, respectively in both gamma irradiated and un-irradiated bulbs. At 5 months of storage, the physiological loss in weight varied from 28.5 to 63.6% in all treatments. Physiological weight loss and rotting percentage were higher in the untreated (control) as well as bulbs radiated @ 10 Gy and 200 Gy. Firmness was better retained in the bulbs irradiated with gamma rays @ 120 Gy bulbs upto 84 days of storage. However, no clear-cut pattern for colour changes (L, a, b values) was observed with respect to the irradiation doses. TSS in bulbs decreased upto 36 days of storage and thereafter increased upto 48th day of storage irrespective of the dose of gamma irradiation. Ascorbic acid content of bulbs decreases significantly in all the irradiation treatments during storage but pyruvic acid initially increased, then decreased and again increased at the end of the storage period in un-irradiated and irradiated treatments. It is concluded that onion bulbs irradiated with gamma rays @ 120 Gy resulted in minimum loss in weight, rotting and sprouting while maintained best quality for 3 months of storage at ambient storage conditions.

15.
Small ; 11(32): 3916-20, 2015 Aug 26.
Article in English | MEDLINE | ID: mdl-25996308

ABSTRACT

The preparation of 1D WS(2) and MoS(2) flexible nanoribbons by laser-induced unzipping of the nanotubes is reported. The nanoribbons are of high quality, uniform width, and devoid of surface contamination. The zig-zag edges in WS(2) nanoribbons give rise to ferromagnetism at room temperature.

16.
Fish Physiol Biochem ; 40(4): 1105-13, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24482095

ABSTRACT

Stocking density is an important factor in cage aquaculture of finfish. Effects of high stocking density (35 fish cubic m(-1)) on a range of biochemical and immunological parameters in Asian seabass reared in open sea floating net cages were compared to fish held in relatively low density (15 fish cubic m(-1)). The results revealed that chronic stress due to high stocking density induced variations in most of the parameters studied as evidenced by increased cortisol and glucose levels and decreased activity of lysozyme, myeloperoxidase and complement. Production of reactive oxygen species, total leucocyte count and total serum protein were also decreased, whereas anti-protease, alkaline phosphatase and acid phosphatase activities were increased in high stocking-density group when compared to low stocking-density group. Effects of chronic stress due to high stocking density were discussed in relation to variations in these parameters.


Subject(s)
Aquaculture/methods , Bass/immunology , Bass/physiology , Crowding , Stress, Physiological/immunology , Animals , Bass/metabolism , Blood Glucose/analysis , Blood Proteins/analysis , Complement System Proteins/immunology , Hydrocortisone/blood , Leukocyte Count/veterinary , Muramidase/metabolism , Nephelometry and Turbidimetry/veterinary , Peroxidase/metabolism , Reactive Oxygen Species/metabolism , Seawater , Spectrophotometry/veterinary
17.
J Food Sci Technol ; 51(8): 1622-5, 2014 Aug.
Article in English | MEDLINE | ID: mdl-25114358

ABSTRACT

The study was carried out on the harvesting and handling methods of okra with the objective to maintain the best quality of pods from harvesting to end consumer especially for export marketing. For that purpose okra cv. 'Punjab-8' pods were harvested with minimum handling (least injuries to the pubescence on the ridges of pod) and normal handling (no safety taken to prevent injuries on pods). Pods were precooled at 15 ± 1ºC, 90-95% RH; jumble packed in the CFB boxes of 2.0 Kg capacity and than stored at 8 ± 1ºC, 90-95% RH. The quality parameters of okra namely texture, chlorophyll content, physiological loss in weight, rotting percentage and general appearance were studied. The pods harvested with minimum handling and field packaging can retain their green colour, crisp texture (maximum force to puncture pod = 500.2 g) with minimum rotting (3.0%) and physiological loss in weight (15.8%) and good appearance upto 13 days of cold storage whereas normal handled pods can be stored upto 5 days at 8 ± 1ºC, 90-95% RH and thereafter lost their general appearance on the 7th day of storage and were discarded. Therefore, in order to maintain high quality of okra from harvesting to the final destination (consumer), the okra pods should be harvested with minimum handling followed by field packaging in CFB boxes.

18.
J Hazard Mater ; 468: 133804, 2024 Apr 15.
Article in English | MEDLINE | ID: mdl-38377911

ABSTRACT

Understanding the bond dissociation energies (BDEs) of per- and polyfluoroalkyl substances (PFAS) helps in devising their efficient degradation pathways. However, there is only limited experimental data on the PFAS BDEs, and there are uncertainties associated with the BDEs computed using density functional theory. Although quantum chemical methods like the G4 composite method can provide highly accurate BDEs (< 1 kcal mol-1), they are limited to small system sizes. To address DFT's accuracy limitations and G4's system size constraints, we examined the connectivity-based hierarchy (CBH) scheme and found that it can provide BDEs that are reasonably close to the G4 accuracy while retaining the computational efficiency of DFT. To further improve the accuracy, we modified the CBH scheme and demonstrated that BDEs calculated using it have a mean-absolute deviation of 0.7 kcal mol-1 from G4 BDEs. To validate the reliability of this new scheme, we computed the ground state free energies of seven PFAS compounds and BDEs for 44 C-C and C-F bonds at the G4 level of theory. Our results suggest that the modified CBH scheme can accurately compute the BDEs of both small and large PFAS at near G4 level accuracy, offering promise for more effective PFAS degradation strategies.

19.
Front Microbiol ; 15: 1356828, 2024.
Article in English | MEDLINE | ID: mdl-38694807

ABSTRACT

Introduction: Deep investigations of host-associated microbiota can illuminate microbe-based solutions to improve production in an unprecedented manner. The poor larval survival represents the critical bottleneck in sustainable marine aquaculture practices. However, little is known about the microbiota profiles and their governing eco-evolutionary processes of the early life stages of marine teleost, impeding the development of suitable beneficial microbial management strategies. The study provides first-hand mechanistic insights into microbiota and its governing eco-evolutionary processes in early life stages of a tropical marine teleost model, Trachinotus blochii. Methods: The microbiota profiles and their dynamics from the first day of hatching till the end of metamorphosis and that of fingerling's gut during the routine hatchery production were studied using 16S rRNA amplicon-based high-throughput sequencing. Further, the relative contributions of various external factors (rearing water, live feed, microalgae, and formulated feed) to the microbiota profiles at different ontogenies was also analyzed. Results: A less diverse but abundant core microbial community (~58% and 54% in the whole microbiota and gut microbiota, respectively) was observed throughout the early life stages, supporting 'core microbiota' hypothesis. Surprisingly, there were two well-differentiated clusters in the whole microbiota profiles, ≤10 DPH (days post-hatching) and > 10 DPH samples. The levels of microbial taxonomic signatures of stress indicated increased stress in the early stages, a possible explanation for increased mortality during early life stages. Further, the results suggested an adaptive mechanism for establishing beneficial strains along the ontogenetic progression. Moreover, the highly transient microbiota in the early life stages became stable along the ontogenetic progression, hypothesizing that the earlier life stages will be the best window to influence the microbiota. The egg microbiota also crucially affected the microbial community. Noteworthily, both water and the feed microbiota significantly contributed to the early microbiota, with the feed microbiota having a more significant contribution to fish microbiota. The results illustrated that rotifer enrichment would be the optimal medium for the early larval microbiota manipulations. Conclusion: The present study highlighted the crucial foundations for the microbial ecology of T. blochii during early life stages with implications to develop suitable beneficial microbial management strategies for sustainable mariculture production.

20.
Phys Chem Chem Phys ; 15(33): 13881-7, 2013 Sep 07.
Article in English | MEDLINE | ID: mdl-23842737

ABSTRACT

Spin-polarized first-principles calculations have been performed to tune the electronic and optical properties of graphene (G) and boron-nitride (BN) quantum dots (QDs) through molecular charge-transfer using tetracyanoquinodimethane (TCNQ) and tetrathiafulvalene (TTF) as dopants. From our results, based on the formation energy and the distance between QDs and dopants, we infer that both the dopants are physisorbed on the QDs. Also, we find that GQDs interact strongly with the dopants compared to the BNQDs. Interestingly, although the dopants are physisorbed on QDs, their interactions lead to a decrement in the HOMO-LUMO gap of QDs by more than half of their original value. We have found a spin-polarized HOMO-LUMO gap in certain QD-dopant complexes. Mülliken population analysis, generation of density of states (DOS) and projected DOS (pDOS) plots, and optical conductivity calculations have been performed to support and understand the reasons behind our findings.

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