Prosopis juliflora hydrothermal synthesis of high fluorescent carbon dots and its antibacterial and bioimaging applications.

Carbon dots have stimulated the curiosity of biomedical researchers due to their unique properties, such as less toxicity and high biocompatibility. The synthesis of carbon dots for biomedical application is a core area in research. In the current research, an eco-friendly hydrothermal technique was employed to synthesize high fluorescent, plant-derived carbon dots from Prosopis juliflora leaves extract (PJ-CDs). The synthesized PJ-CDs were investigated by physicochemical evaluation instruments such as fluorescence spectroscopy, SEM, HR-TEM, EDX, XRD, FTIR, and UV-Vis. The UV-Vis absorption peaks obtained at 270 nm due to carbonyl functional groups shifts of n→π*. In addition, a quantum yield of 7.88 % is achieved. The synthesized PJ-CDs showing the presence of carious functional groups O-H, C-H, C=O, O-H, C-N and the obtained particles in spherical shape with an average size of 8 nm. The fluorescence PJ-CDs showed stability against various environmental factors such as a broad range of ionic strength and pH gradient. The antimicrobial activity of PJ-CDs was tested against a Staphylococcus aureus, and a Escherichia coli. The results suggest that the PJ-CDs could substantially inhibit the growth of Staphylococcus aureus. The findings also indicate that PJ-CDs are effective materials for bio-imaging in Caenorhabditis elegans and they can be also used for pharmaceutical applications.

Long-term storage does not affect the infectivity of entomopathogenic nematodes on insect hosts.

Entomopathogenic nematodes (EPNs) are effective biopesticides used in insect control. There are several formulations of entomopathogenic nematodes which are commercially available, but their popularity is low because the requirement of periodic release of stored entomopathogenic nematodes in field has reduced infectivity and is a constraint in large-scale repeated application of entomopathogenic nematodes in field. So, in order to overcome this impediment, the current study focuses on storage of entomopathogenic nematodes for a longer period of time using encapsulating beads. In this study, three EPNs, namely, Steinernema carpocapsae, Steinernema monticolum, and Rhabditis blumi, were encapsulated with Arabic gum and sodium alginate gel beads at different concentrations. Bio-efficacy of stored EPNs at different concentrations (50, 100, 200, 500, and 1000 infective juveniles (IJs)) in varying time intervals of 3, 6, 9, and 12 weeks were tested against Culex quinquefasciatus larvae. The results show that, after 3 weeks of storage, these entomopathogenic nematode species showed survival up to 96%, and in 12-week storage, survival rate was 50%. The virulence of the progeny that emerged from these stored entomopathogenic nematodes was similar to the fresh infective juveniles. The results of the present study show that Arabic gum-sodium alginate combination is a promising approach toward storing entomopathogenic nematodes. Furthermore, semi-field trials showed 70-90% larval mortality at a concentration of 3000 IJs (encapsulated and stored entomopathogenic nematodes in S. monticolum, S. carpocapsae, and R. blumi) on C. quinquefasciatus larvae. KEY POINTS: • Increased survival of stored EPNs (S. carpocapsae, S. monticolum, and R. blumi) in encapsulated gel using Arabic gum, sodium alginate, and yeast cells was assessed. • The efficacy was greater in stored EPNs at different concentrations from 3 to 12 weeks. • Semi-field trials of stored encapsulated EPNs are efficient in mosquito larval control.

Bio-efficacy of Geobacillus thermodenitrificans PS41 against larvicidal, fungicidal, and plant growth-promoting activities.

The microbial interactions with plant hosts were known to establish plant growth and beneficial productivity. Some bacteria, fungi, actinomycetes, yeast, and algae have proven as potential effective microbes in agricultural field. In this study, the insecticidal effect of Geobacillus thermodenitrificans PS41 secondary metabolites was tested against third instar larvae of Spodoptera litura, with mortality rate 60.26 ± 1.5% which might influence the agropest management. The test bacterial metabolites were subjected to GC-MS analysis. Totally, 17 different compounds were identified from the ethyl acetate extract metabolites of PS41 strain. The highest peak was obtained with behenic alcohol compound followed by 1-octadecene and penta erythrityl tetrachloride. The Geobacillus thermodenitrificans PS41 secondary metabolites showed potential antifungal activity against plant pathogenic fungi. The highest inhibit was attained against Cladosporium sp., (25 mm) followed by Rhizoctonia solani and Alternaria brassicola (23 mm). However, no toxic effect was exerted upon earthworm (Perionyx excavatus) when treated with PS41 bacterial metabolites. The potential PS41 strain was also found supporting the plant growth. The potential bacterial strain PS41 did not show antagonistic activity against soil bacteria such as Rhizobium sp., Azotobacter sp., Azospirullum brasilense, Pseudomonas fluorescens and Bacillus megaterium. The potential test organism, Geobacillus thermodenitrificans PS41, possessing biopesticide and biofertilizer properties can be a suitable ecofriendly organic applicant in agricultural field for enhancing crop production.

Biosynthesis and characterization of silver nanoparticles from symbiotic bacteria Xenorhabdus nematophila and testing its insecticidal efficacy on Spodoptera litura larvae.

Spodoptera litura, one of the polyphagous pests, causes huge economical lose and use of chemical pesticide causes impact to the environmental. The present study deals with the use of cell- free supernatant of bacteria Xenorhabdus nematophila NP-1 strain for synthesizing silver nanoparticles and analyzing its larvicidal ability against Spodoptera litura. Color change from yellow to dark brown specifies the synthesis of AgNPs. UV-Vis spec indicates the presences of AgNPs at 440 nm λmax and functional groups; alcohols, carboxylic acids, aromatics, alkylhalides, ethers and phenols were confirmed by FTIR. SEM revealed the synthesized AgNPs is in spherical shape, EDaX confirms the elemental composition and the crystalline nature were observed using XRD. GC-MS analysis showed presence of Benzencepropanoic acid, 1, 3, 5 Trichloropent-2-ene, 1,1-Dichloro-2,3- dicmethycycloprone and 1,2-benzenedicarboxylic acid bioactive compounds some of which may be responsible for insecticidal and antibacterial activity. The antibacterial activity against S. aureus, B. subtilis and K. pneumoniae showed maximum zone of inhibition at 100 µL/mL. Larvicidal activity of S. litura shows highest mortality at 48 h. In potted plant experiment, AgNPs treated plants showed less damage, with less leaf consumption by S. litura larvae. Further, the synthesis of AgNPs were targeted to zebrafish embryos (non- target organism) and it didn't exhibit any toxic effect even at higher concentration. Our experiment concludes that, AgNPs synthesized using NP-1 strain has highest antimicrobial and insecticidal activity, which can be used in biomedical and biopesticides.

Biogenic synthesis of ZnO nanoparticles mediated from Borassus flabellifer (Linn): antioxidant, antimicrobial activity against clinical pathogens, and photocatalytic degradation activity with molecular modeling.

Borassus flabellifer leaf extract has been used for rapid biogenic synthesis of zinc oxide nanoparticles (ZnO-NPs) due to rich source of bioactive compounds. The synthesized ZnO-NPs were preliminarily confirmed by UV-visible spectroscopy adsorption peak range at 365 nm. The XRD (X-ray diffraction) confirms purity of ZnO-NPs that were crystalline in nature. The analysis of FT-IR (Fourier-transform infrared spectroscopy) confirms the presence of the following functional group such as alcohol, phenols, carboxylic acids, primary amides, secondary amides, and alkyl halide. The Field Emission Scanning Electron Microscope (FE-SEM) analysis indicated that ZnO-NPs were in spherical shape, followed by EDX analysis which confirmed the presence of Zn-element. Antimicrobial effect of ZnO-NPs was investigated using different clinical pathogens like bacteria Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Klebsiella Pneumonia, and Pseudomonas aeruginosa and fungi Aspergillus flavus, Candida albicans, and Penicillium expansum which confirmed ZnO-NPs efficiency as an antimicrobial agent. ZnO-NP antimicrobial efficiency was observed in higher zone of inhibition at 50 µg/mL concentrations. Antioxidant activity was ascertained to be used for several biomedical applications. The ZnO-NPs efficiently degraded the environmental toxic dyes (methylene blue and crystal violet) under sunlight, and up to 95% higher degradation was achieved in both dyes. In support of photo light degradation, the study was progressed to understand the ZnO-dye interaction stability using molecular mechanism, and it shows efficient bonding features in the NPs environment. Overall, this investigation has great potential for being an effective and eco-friendly material used in environmental applications.

Novel strategy for biodegradation of 4-nitrophenol by the immobilized cells of Pseudomonas sp. YPS3 with Acacia gum.

The mass organic compound 4-nitrophenol with low molecular is involved in many chemicals processes and most common organic pollutants. 4-Nitrophenol (4-NP) existing in soils and water bodies, thereby causing severe environmental impact and health risk. Even low concentrations are harmful to health and potential mutagenic and carcinogenic. Though the existing methods of biodegradation though effective, their popularity is hindered due to high cost. Hence, in the present study a less expensive method involving the use of Pseudomonas sp. with gum arabic (PAA) was tested. The biodegradation of 4-NP was thoroughly investigated by progressive characterization methods. The promising Pseudomonas sp. YPS 3 was identified with biochemical and molecular identification process. The average particle sizes of stable crystalline PAA was 8-20 nm. The experiments were conducted with optimized parameters viz., pH (7.0), concentration (30 ppm), temperature (37 °C) and time (6 h). The study was tested as adsorbent particle size on 4-NP concurrent adsorption-biodegradation. In addition, these Pseudomonas sp. YPS3 and its PAA are used as an eco-friendly for removal of toxic organic 4-NP pollutant from the ecosystems.

Identification and characterization of Pseudomonas aeruginosa derived bacteriocin for industrial applications.

Drug resistance has become a major threat due to the frequent use of commercial antibiotics and there is an urgent need to combat this problem. Having this in mind, the present research was aimed at developing a novel P. aeruginosa puBac bacteriocin molecule. The bacteriocin was purified by ammonium sulfate precipitation followed by Sepharose FF and Sephadex G15 column purification and the purified bacteriocin has been reported to have the molar mass of 43 kDa. The findings of the optimization showed that 3500 AU/mL of bacteriocin was obtained at 37 °C, 3410 AU/mL of bacteriocin at 6.5 pH and 3780 AU/mL of bacteriocin at 48 h of incubation time. In addition, 3863 AU/mL of bacteriocin activity was obtained with Tween-80 followed by 3789 AU/mL with a concentration of 2% NaCl and 4200 AU/mL for Fe2+. PuBac bacteriocin has been shown to have a significant effect on test pathogens. For example, E. coli was found to have 3.6 µM of MIC, followed by Staphylococcus sp. with 6.15 µM of MIC and Bacillus sp. with a 7.5 µM of MIC. The remarkable properties of bacteriocin suggest that it could be used in various pharmaceutical and food industries.

Novel preparation of fungal conidiophores biomass as adsorbent for removal of phosphorus from aqueous solution.

The present study focused on phosphorus adsorption by novel fungal conidiophores biomass in aqueous solution. Fungal Conidiophores biomass was prepared from the fungal strains Aspergillus oryzae (YFK) and Fusarium oxysporum (YVS2). The functional groups and morphology of Conidiophores Biomass (CB) from these strains were characterized by FTIR and SEM. FTIR confirms the presence of alcohol, carboxylic acid, carbon dioxide, cyclic alkene, amine, alkene, fluoro compound, and halo compound groups. Batch mode study was carried out with two CB's such as Aspergillus oryzae CB (ACB) and Fusarium oxysporum CB (FCB) with initial concentration of phosphorus ranging from 20 to 100 mg L-1. Based on the batch experiments, the adsorption kinetics (pseudo first order and pseudo second order), isotherms (Freundlich and Langmuir models), and thermodynamic (standard entropy, energy, and enthalpy) parameters were calculated. The adsorption kinetics and isotherm studies showed that the adsorption data well fitted with PSO kinetic model. From the isotherm results, it was found that ACB and FCB exhibited highest adsorption capacity 25.64 mg g-1 and 26.32 mg g-1 of phosphorus respectively at the optimal condition of pH (7), time (90 min), dose (250 mg), and room temperature (35 °C). Thermodynamics values were found to be endothermic and spontaneous in nature for phosphorus adsorption. Finally, the results suggested that the ACB and FCB are economically feasible cost-effective adsorbent for removal of phosphorus in wastewater treatment. Graphical abstract.

Analysing the relationship between polysomnographic measures of sleep with measures of physical and cognitive fatigue in people with multiple sclerosis.

OBJECTIVES: We aimed to determine whether there was a relationship between objective measures of sleep measured by polysomnography and measures of physical and cognitive fatigue in patients with Multiple Sclerosis (MS). METHODS: People with MS of age 18-50 years of any subtype attending the OPD satisfying the revised 2010 McDonald criteria were recruited. Modified Fatigue Impact Scale (MFIS) and the Fatigue Severity Scale (FSS) were used to assess physical fatigue. Cognitive fatigue was measured with modified versions of the Stroop test, modified Symbol Digit Modalities Test, Serial Addition Test, and with latency and amplitude of the P300 evoked potential. Percentage of N1, N2, N3 and REM sleep stages, Sleep onset latency, Sleep efficiency, Wake after sleep onset, Respiratory event index, Periodic limb movement index were the measures recorded with polysomnography. RESULTS: Among 113 patients, 43 (38.05%) complained of disturbed sleep and 88 (77.88%) complained of increased fatigability and tiredness. Mean MFIS score of the sample was 42.34 ±â€¯9.09. Mean FSS score was 19.12 ±â€¯9.42. Polysomnographic measures of sleep showed a significant correlation with objective measures of cognitive fatigue and did not show any significant correlation with measures of physical fatigue. CONCLUSIONS: Sleep impairment is a very common problem in people with MS justifying routine polysomnographic evaluation. We have found evidence that though sleep impairment is not related to physical fatigue, it is strongly related to cognitive fatigue.

A comparison of estimates of doses to radiotherapy patients obtained with the dicentric chromosome analysis and the γ-H2AX assay: Relevance to radiation triage.

The γ-H2AX assay was investigated as an alternative to the time-consuming dicentric chromosome assay (DCA). Radiation doses to 25 radiotherapy patients were estimated in parallel by DCA and the γ-H2AX assay. The γ-H2AX assay yielded doses in line with the calculated equivalent whole body doses in 92% of the patients, whereas the success rate of DCA was only 76%. The result shows that the γ-H2AX assay can be effectively used as a rapid and more precise alternative to DCA.

Environmentally benign antifouling activity and toxic properties of bioactive metabolites from mangrove Excoecaria agallocha L.

This study was aimed to investigate the antifouling (AF) potentials and toxic properties of methanol extract from leaves of mangrove Excoecaria agallocha. Antimicrofouling activity results inferred that this extract strongly inhibited fouling bacterial and microalgal growth. This extract had also inhibited the settlement of brown mussel Perna indica and larvae of barnacle Balanus amphitrite. Further, EC50 < LC50 and therapeutic ratio > 1 together propagated non-toxic nature of the extract. Mollusk foot adherence assay result showed complete inhibition of foot spreading and loss of attachment of common rocky fouler Patella vulgata to the substrata. Field assay results affirmed that this extract effectively deterred settlement of biofoulers. Purification and GC-MS analysis of bioassay-guided active spot evidenced presence of three major compounds (> 85%) responsible for the promising AF activity. The identified lead compounds subjected to an estimation (BIOWIN™) program developed by United States Environmental Protection Agency (USEPA) predicts that they are biodegradable in nature. Graphical abstract.

Cancer Therapeutic Proficiency of Dual-Targeted Mesoporous Silica Nanocomposite Endorses Combination Drug Delivery.

The cargo-loaded mesoporous silica nanoparticles (MSNs) with convenient surface modification can facilitate the development of the innovative nanodrug system. Herein, the present investigation described the electrostatically self-assembled MSNs as a nanosized drug carrier to realize potent synergistic chemotherapy based on the specificity in targeting cytoplasm and nucleus of tumor cells. In this context, the primarily constructed MSNs were subjected with anticancer drug topotecan (TPT) into its large pores. Then, the selective TAT peptide (a nuclear localization signal peptide) was anchored onto TPT-loaded MSNs (TPT-MSN). Subsequently, the positive surface of TPT-MSN-TAT was capped with negatively charged components, poly(acrylic acid) (PAA)-cRGD peptide and citraconic anhydride (CAH)-metformin (MT), and acted as a smart gatekeeper. Comparatively, PAA-cRGD attached onto MSNs serving as the targeted molecules could upsurge by invasion into cancer cells. Interestingly, the acidic pH of the lysosomal compartment in tumor cells triggers the conjugated CAH from the polymer decorated mesoporous silica (PMS) nanocomposite and could efficiently release MT into the cytoplasm. Consequently, the remaining TPT-MSN-TAT efficiently targets the nucleus and delivers the TPT to improve synergistic chemotherapeutic effects. The precisely released drugs were individually enhanced in the in vitro and in vivo cell killing efficiencies. Thus, the study provides a potential drug delivery podium through combined drugs to realize cancer cell targeting approach.

A study of cognitive fatigue in Multiple Sclerosis with novel clinical and electrophysiological parameters utilizing the event related potential P300.

BACKGROUND: Although cognitive fatigue plays a significant part in Multiple Sclerosis (MS) related impairment, knowledge regarding it is largely lacking. Until now, not many tools are available to a clinician to detect cognitive fatigue. The subjective tools of fatigue have never been reliable.tabl OBJECTIVES: To assess the prevalence and clinical/ demographic profile of cognitive fatigue in MS using novel clinical and electrophysiological measures and to find their accuracy. We also aimed to test the three leading hypotheses - the temporal fatigue, cognitive load and cognitive domain hypotheses of cognitive fatigue in MS. METHODS: 50 consecutive MS patients attending the Neurology OPD in Madras Medical College, Chennai from May 2015 to February 2016 satisfying the 2010 revised McDonald criteria for MS with an equal number of matched controls were recruited. Modified versions (a shorter version, and longer and more demanding versions) of the Stroop test, symbol digit modalities test, and serial addition tests were used in addition to modified tests of P300 latency and amplitude each specifically tailored to reveal cognitive fatigue. RESULTS: Out of the seven measures of cognitive fatigue used, 46% (n=23) of MS patients had impairment in two or more of the scores compared to that of 8% (n=4) in the healthy control group. The Expanded disability status scale (EDSS) scores were significantly higher for MS patients with cognitive fatigue compared to those without. All the clinical and electrophysiological measures used in this study had a relatively high sensitivity and specificity. In addition, all the clinical measures correlated with the electrophysiological measures of cognitive fatigue in this study. Our data also supported all three hypotheses implying that cognitive fatigue in MS may be a multifaceted entity. CONCLUSION: Cognitive fatigue is widely prevalent in MS and can be detected with specific tools. The tools developed and described in this study may be used as an effective means of detecting cognitive fatigue in MS patients and thus allowing patients to realise their limitations. Institution of appropriate remedial measures like advising such patients to break up a more cognitively demanding task into smaller subtasks may help to improve their quality of life.

Altered oral sensory perception in tongue thrusters with an anterior open bite.

The aim of this study was to evaluate oral sensory perception in patients with an anterior open bite (AOB) and associated tongue thrusting activity. This study was performed in the Department of Orthodontics, Government Dental Hospital, Chennai, on 30 subjects (16 females and 14 males) aged from 12 to 17 years with an AOB associated with a tongue thrust and in a control group of 100 subjects (53 females and 47 males aged from 12 to 17 years) with a normal occlusion and no oral habits. Stereognosis and two-point discrimination (2PD) were employed for evaluation of oral sensory perception. Statistical comparison was undertaken using a Student's t-test. Stereognostic ability was altered in children with an AOB associated with a tongue thrust (t = 15.2, probability of occurrence P < 0.01). The mean oral stereognostic score in the control group was 31.8 and in tongue thrusters 25.3. The AOB group also showed a diminished 2PD threshold at the tip of the tongue [control group 1.08 mm, tongue thrusters with an AOB 1.64 mm (t = 7.3, P < 0.01)]. This finding highlights the fact that the tongue plays a vital role in oral sensory perception. Oral stereognostic tests and 2PD as diagnostic tools are valuable in the evaluation of oral sensory perception.