Green versus sol-gel synthesis of zinc oxide nanoparticles (ZnO NPs) were carried out and antimicrobial activity was evaluated against a wide panel of bacterial and fungal pathogens. Five plants seed ...extracts were used for green synthesis from Brassicaceae family, whereas the sol-gel method was adopted in the case of chemical synthesis. The ZnO NPs were characterized using Ultraviolet-Visible (UV-Vis), Energy Dispersive X-ray (EDX), X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) techniques. The antimicrobial potential of the synthesized NPs was assessed against bacterial and fungal strains by disc diffusion method. The size of the ZnO NPs was in the range of 100–150nm. The ZnO NPs showed promising antimicrobial activity and zones of inhibition were in the range of 10–20mm, whereas Streptomycin (standard drug) showed the zone of inhibition of 25mm. The synthesized ZnO NPs furnished promising antibacterial and antifungal potential. The green route of synthesis is rather safe and eco-friendly when compared to chemical route and could be used for the fabrication of ZnO NPs as an antimicrobial agent.
In the recent past the molecular engineering of coordination metal complexes has attracted new interest in the field of nonlinear optics (NLO), which find their applications in optoelectronics and ...optical data storage technology it is the transition metal along with the organic moieties that induce the control over the optical nonlinearity these properties of the materials not only enhance the intensity but also have a drastic effect on the polarization of incident laser light. This is an important criterion for all-optical switching applications. Coordination metal complexes are a very good target to aim at because of their robustness, physical and chemical stability, and other variable degrees that lead to an increment in NLO responses, most importantly all these properties can be either manipulated or tailored or tunable according to the requirement. Apart from the metal center, these molecules acting as legend must be chromophoric with donor-acceptor nature. In these molecules, the NLO response is intrinsically based on the ‘push-pull’ mechanism of the electrons. Obviously to these molecules, when a metal is in contact, the electronic push-pull mechanism alters rendering the molecule non-symmetric. This review article mainly concentrates on small mononuclear metal complexes for NLO application.
Sustainability in power generation mainly depends on the transition from fossils to sustainable energy resources. Biomass from the crop residue has huge potential for renewable power generation, but ...it is still not utilized to its full potential. This study presents a comprehensive methodology to evaluate and forecast the current and future availability of selective crop residue to generate renewable energy. A forecast model incorporating historical trends in the crop yield has been developed in MATLAB and implemented for crop residue based biomass resource assessment of five primary crops (wheat straw, rice husk, rice straw, cotton straw, corn stover, and bagasse) in order to estimate the energy generation potential for Pakistan from 2018 till 2035. It was found that about 40 million tonnes of crop residue was available in Pakistan for power generation in the year 2018 considering a residue removal (availability) factor of 50%. This translates to an estimated potential of about 11,000 MW of electricity generation capacity using crop residue derived biomass for 2018. This capacity is predicted to gradually increase up to 16,000 MW by the year 2035 based on the trends in the growth of crop production since 2001. The suitability of a potential region for the installation of 100 MW biomass-fired power plants was also assessed by calculating crop residue density and an equivalent collection radius (Re) of 50 km (km). Punjab province of Pakistan, being an agricultural province, with relatively better road infrastructure can sustain crop residue based power plants of up to 7000 MW cumulative capacity at various locations. The challenges, such as economic, logistics, regulatory and political barriers, in generating renewable energy from biomass along with their potential solutions were also discussed. The study also provides a baseline for future research to evaluate and forecast the growth in bio-power generation potential of any biomass resource in a region based on crop yield and area of the region.
•Assessment of renewable energy potential from selected crop residue in Pakistan.•Pakistan has an estimated power generation capacity of 11,000 MW from crop residue.•Forecast model to predict crop residue availability for power generation in future.•Model also helps to define biomass-based power plant location suitability.•Challenges such as economic, logistics, regulatory and political were also discussed.
Monsoon precipitation plays a crucial role in shaping the diversity of vegetation in the Himalayas, both in terms of temporal and spatial distribution. While palynology has traditionally been ...employed to reconstruct the past climate of the Himalaya, there has been limited understanding of how monsoon-related changes affect the structure and distribution of vegetation. To address this, we analysed pollen data from a 3 m deep sedimentary profile in the higher Sikkim Himalaya to reconstruct monsoon driven changes in vegetation diversity. Our results show a highly fluctuating trend of pollen and diversity parameters at late-Pleistocene-Holocene transition for which fluctuating hydroclimatic conditions and differential pollen preservation in coarser sediments is attributed. During the Early Holocene (10,438–7934 cal yrs BP) favourable hydroclimatic conditions led to a rapid expansion of mixed broad-leaved forests, marked by higher values of richness and alpha diversity. Between 7934 and 5481 cal yrs BP, the region experienced moderate hydroclimatic conditions that facilitated expansion and diversification of woody taxa, and correlated with the global Holocene Climate Optimum (HCO). Conversely, from 5481 to3949 cal yrs BP, declining total pollen count (TPC), species richness, and alpha diversity indicates significant shifts in vegetation composition under deteriorating climatic conditions, which corresponds with the 4.2 ka event worldwide. From 3949 to 2049 cal yrs BP, an increasing yet variable trend in TPC and diversity indices, suggests warm-humid conditions prevailed in the region. During the last 1086 cal yrs, an increasing trend is recorded in the palyno assemblage and diversity parameters suggesting ameliorating climate, matches well with the Mediaeval Climate Anomaly (MCA). Our inferences suggest that the palyno assemblage and diversity parameters are quiet sensitive to warm and humid conditions.
It is thought that the presence of music influences episodic memory encoding. However, no studies have isolated the influence of music liking - the hedonic value listeners attribute to a musical ...stimulus - from that of the core affect induced by the presence of that music. In an online survey, participants rated musical excerpts in terms of how much they liked them, as well as in terms of felt valence, felt arousal and familiarity. These ratings were then used to inform the stimuli presented in an online episodic memory task which, across different scenarios, involved dragging cued objects to cued locations and then recalling details of what was moved, where they were moved to and the order of movements made. Our results showed an influence of liking and music-reward sensitivity on memory for what was moved, as well as a detrimental effect of arousing musical stimuli on memory for un-cued scenario details. Taken together, our study showcases the importance of episodic memory paradigms that involve rich spatiotemporal contexts and provides insights into how different aspects of episodic memory may be influenced by the presence of music.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Background
This study assessed the feasibility of a preoperative high‐intensity interval training (HIT) programme in patients awaiting elective abdominal aortic aneurysm repair.
Methods
In this ...feasibility trial, participants were allocated by minimization to preoperative HIT or usual care. Patients in the HIT group were offered three exercise sessions per week for 4 weeks, and weekly maintenance sessions if surgery was delayed. Feasibility and acceptability outcomes were: rates of screening, eligibility, recruitment, retention, outcome completion, adverse events and adherence to exercise. Data on exercise enjoyment (Physical Activity Enjoyment Scale, PACES), cardiorespiratory fitness (anaerobic threshold and peak oxygen uptake), quality of life, postoperative morbidity and mortality, duration of hospital stay and healthcare utilization were also collected.
Results
Twenty‐seven patients were allocated to HIT and 26 to usual care (controls). Screening, eligibility, recruitment, retention and outcome completion rates were 100 per cent (556 of 556), 43·2 per cent (240 of 556), 22·1 per cent (53 of 240), 91 per cent (48 of 53) and 79–92 per cent respectively. The overall exercise session attendance rate was 75·8 per cent (276 of 364), and the mean(s.d.) PACES score after the programme was 98(19) (‘enjoyable’); however, the intensity of exercise was generally lower than intended. The mean anaerobic threshold after exercise training (adjusted for baseline score and minimization variables) was 11·7 ml per kg per min in the exercise group and 11·4 ml per kg per min in controls (difference 0·3 (95 per cent c.i. –0·4 to 1·1) ml per kg per min). There were trivial‐to‐small differences in postoperative clinical and patient‐reported outcomes between the exercise and control groups.
Conclusion
Despite the intensity of exercise being generally lower than intended, the findings support the feasibility and acceptability of both preoperative HIT and the trial procedures. A definitive trial is warranted. Registration number: ISRCTN09433624 (
https://www.isrctn.com/).
Precursor to a bigger trial
A procedure based on QuEChERS extraction and a simultaneous liquid–liquid partition clean-up was developed. The procedure involved extraction of hydrated soil samples using acetonitrile and clean-up ...by liquid–liquid partition into n-hexane. The hexane extracts produced were clean and suitable for determination using gas chromatography–tandem mass spectrometry (GC–MS/MS). The method was validated by analysis of soil samples, spiked at five levels between 1 and 200
μg
kg
−1. The recovery values were generally between 70 and 100% and the relative standard deviation values (%RSDs) were at or below 20%. The procedure was validated for determination of 19 organochlorine (OC) pesticides. These were hexachlorobenzene (HCB), α-HCH, β-HCH, γ-HCH, heptachlor, heptachlor epoxide (
trans), aldrin, dieldrin, chlordane (
trans), chlordane (
cis), oxychlordane, α-endosulfan, β-endosulfan, endosulfan sulfate, endrin,
p,
p′-DDT,
o,
p′-DDT,
p,
p′-DDD and
p,
p′-DDE. The method achieved low limits of detection (LOD; typically 0.3
μg
kg
−1) and low limits of quantification (LOQ; typically 1.0
μg
kg
−1). The method performance was also assessed using five fortified soil samples with different physico-chemical properties and the method performance was consistent for the different types of soil samples. The proposed method was compared with an established procedure based on Soxtec extraction. This comparison was carried out using six soil samples collected from regions of Pakistan with a history of intensive pesticide use. The results of this comparison showed that the two procedures produced results with good agreement. The proposed method produced cleaner extracts and therefore led to lower limits of quantification. The proposed method was less time consuming and safer to use. The six samples tested during this comparison showed that soils from cotton growing regions contained a number of persistent OC residues at relatively low levels (<10
μg
kg
−1). These residues were α-HCH, γ-HCH, heptachlor, chlordane (
trans),
p,
p′-DDT,
o,
p′-DDT,
p,
p′-DDD,
p,
p′-DDE, β-endosulfan and endosulfan sulfate.
Current work presents a unique material for nonlinear optical applications. Two Ni-complexes: Nickel-Chloride-Curcumin NiCl2(Cur).2H2O (NiClCur) and Nickel-Acetate-Curcumin Ni(C2H2O3)2·2H2O (NiAcCur) ...were synthesized using curcumin (Cur) as a base ligand. Various spectroscopic techniques like UV–Vis, FT-IR, 1H NMR, 13C NMR, Mass spectrometry, and Elemental analysis have been used to determine both complexes’ structural characteristics. 1H NMR study discloses the complexation between metal and ligand. Theoretical analysis of NiClCur and NiAcCur is accomplished by using Conceptual-Density-Functional-Theory (CDFT) methodology. CDFT-based descriptors such as HOMO-LUMO energy gap, dipole moment, molecular hardness, softness, electronegativity, and electrophilicity index of both species are calculated. HOMO-LUMO energy gap of NiClCur and NiAcCur are found as 2.699 eV and 2.400 eV respectively. The Ni-complexes were studied for nonlinear optics (NLO) and transmission measurements were performed using a Z-scan method with nanosecond laser pulses at 532 nm. Along with transmission measurements, the optical limiting (OL) behavior of Ni-complexes was calculated. Quantitative analysis of the two-photon absorption coefficients for NiClCur and NiAcCur was determined to be 5 × 10−11 m/W and 9 × 10−12 m/W, respectively. The normalized transmittance (NT) dropped from 100% to 60% in both NiClCur and NiAcCur. This work opens up a new insight into the field of NLO, where Cur-based metal novel complexes are implemented.
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•Successfully synthesized two Curcumin-based Nickel complexes.•Structure optimizations using Computational study.•High optical nonlinearity in the complexes due to excellent charge transfer.•Molecules show superior optical limiting properties due to large nonlinear absorption.
This may be the first research to our knowledge that details the NLO characteristics of two zinc complexes with curcumin acting as a base ligand in solution form (viz. Zinc acetate-Curcumin (ZnAcCur) ...and Zinc acetate-Thiolene-Curcumin (ZnThCur)). The structural features of both complexes have been derived from various characterization techniques like UV–Vis, FT-IR, 1H NMR, 13C NMR, Elemental analysis and Mass spectrometry. The nature of ligand-to-metal interaction was validated by 1H NMR spectral studies along with DFT calculations. The result shows that the molecular system ZnAcCur is more stable with a HOMO-LUMO energy gap of 3.334 eV. The addition of an extra moiety in the form of thiolene decreased the stability and in turn the NLO properties. The computational study was extended to calculate various DFT-based descriptors. Nonlinear optical transmission was measured by a Z-scan technique with the implementation of nanosecond laser pulses at 532 nm, showed that both complexes can be prominently applied for optical limiting (OL) properties.
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•A first time report on NLO applications of Curcumin based metal complexes.•Physicochemical characterization of complexes supported by DFT calculations.•Computational study, extended to calculate various DFT-based descriptors.•Studies suggest that the molecules can be prominently applied for optical limiting (OL) properties.
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