Purification and Characterization of Novel Antihypertensive and Antioxidative Peptides From Whey Protein Fermentate: In Vitro, In Silico, and Molecular Interactions Studies

OBJECTIVE

The goal of this research was to purify and characterize the novel angiotensin-converting enzyme (ACE)-inhibitory and antioxidant peptides from fermented whey protein concentrate produced by Lactobacillus paracasei and Saccharomyces cerevisiae in a co-fermentation system.

METHOD

Whey protein fermented with lactic acid bacteria and yeast culture was analyzed for antioxidative, ACE inhibition, as well as anti-inflammatory activity followed by SDS-PAGE, isoelectric focusing, and 2-dimensional (2D) analysis. Anti-inflammatory activity of whey protein fermentate was also studied on the RAW 264.7 cell line. The bioactive peptides were separated from the whey protein fermentate using reverse-phase high-performance liquid chromatography (RP-HPLC) and reverse-phase liquid chromatography mass spectrometry (RPLC/MS), and thus identification and characterization of purified bioactive peptide was performed.

RESULTS

Whey protein fermentate samples' bioactivity was analyzed at specific time intervals at 12, 24, 36, and 48 hours at 37 °C for M11 and at 25 °C for WBS2A. The development settings (incubation time [12, 24, 36, and 48 hours) and inoculation rates [1.5%, 2.0%, and 2.5%]) were optimized for peptide synthesis via the o-phthaldialdehyde (OPA) method (proteolytic activity). Maximum proteolytic activity was observed at 37 °C for M11 (6.50 mg/mL) and at 25 °C for WBS2A (8.59 mg/mL) for 48 hours of incubation. Protein profiling was carried out using SDS-PAGE and 2D gel electrophoresis, in which Sodium dodecyl-sulfate (SDS) exhibited protein bands in the 10- to 55-kDa range, while 2D showed protein bands varying from 10 to 70 kDa. Every spot from 2D was digested by trypsin and identified by RPLC/MS. Protein fractionations (3- and 10-kDa permeates) were carried out employing RP-HPLC. Whey protein fermentate has anti-inflammatory action in RAW 264.7 macrophages that have been exposed to lipopolysaccharide. A molecular docking system was also used to investigate the interactions of peptides (AFLDSRTR, ILGAFIQIITFR) with human myeloperoxidase enzyme.

CONCLUSIONS

The antihypertensive and antioxidative peptides discovered from whey protein fermentate may be helpful in the design of pharmacologically active healthy ingredients in the upcoming years.

Speckle-based deep learning approach for classification of orbital angular momentum modes

We present a speckle-based deep learning approach for orbital angular momentum (OAM) mode classification. In this method, we have simulated the speckle fields of the Laguerre-Gauss (LG), Hermite-Gauss (HG), and superposition modes by multiplying these modes with a random phase function and then taking the Fourier transform. The intensity images of these speckle fields are fed to a convolutional neural network (CNN) for training a classification model that classifies modes with an accuracy >99%. We have trained and tested our method against the influence of atmospheric turbulence by training the models with perturbed LG, HG, and superposition modes and found that models are still able to classify modes with an accuracy >98%. We have also trained and tested our model with experimental speckle images of LG modes generated by three different ground glasses. We have achieved a maximum accuracy of 96% for the most robust case, where the model is trained with all simulated and experimental data. The novelty of the technique is that one can do the mode classification just by using a small portion of the speckle fields because speckle grains contain the information about the original mode, thus eliminating the need for capturing the whole modal field, which is modal dependent.

Changing pattern of admissions for acute myocardial infarction in India during the COVID-19 pandemic

AIM

Studies on the changes in the presentation and management of acute myocardial infarction (AMI) during the COVID-19 pandemic from low- and middle-income countries are limited. We sought to determine the changes in the number of admissions, management practices, and outcomes of AMI during the pandemic period in India.

METHODS & RESULTS

In this two-timepoint cross-sectional study involving 187 hospitals across India, patients admitted with AMI between 15th March to 15th June in 2020 were compared with those admitted during the corresponding period of 2019. We included 41,832 consecutive adults with AMI. Admissions during the pandemic period (n = 16414) decreased by 35·4% as compared to the corresponding period in 2019 (n = 25418). We observed significant heterogeneity in this decline across India. The weekly average decrease in AMI admissions in 2020 correlated negatively with the number of COVID cases (r = -0·48; r2 = 0·2), but strongly correlated with the stringency of lockdown index (r = 0·95; r2 = 0·90). On a multi-level logistic regression, admissions were lower in 2020 with older age categories, tier 1 cities, and centers with high patient volume. Adjusted utilization rate of coronary angiography, and percutaneous coronary intervention decreased by 11·3%, and 5·9% respectively.

CONCLUSIONS

The magnitude of reduction in AMI admissions across India was not uniform. The nature, time course, and the patient demographics were different compared to reports from other countries, suggesting a significant impact due to the lockdown. These findings have important implications in managing AMI during the pandemic.

Bio-therapeutics from human milk: prospects and perspectives

Human milk is elixir for neonates and is a rich source of nutrients and beneficial microbiota required for infant growth and development. Its benefits prompted research into probing the milk components and their use as prophylactic or therapeutic agents. Culture-independent estimation of milk microbiome and high-resolution identification of milk components provide information, but a holistic purview of these research domains is lacking. Here, we review the current research on bio-therapeutic components of milk and simplified future directions for its efficient usage. Publicly available databases such as PubMed and Google scholar were searched for keywords such as probiotics and prebiotics related to human milk, microbiome and milk oligosaccharides. This was further manually curated for inclusion and exclusion criteria relevant to human milk and clinical efficacy. The literature was classified into subgroups and then discussed in detail to facilitate understanding. Although milk research is still in infancy, it is clear that human milk has many functions including protection of infants by passive immunization through secreted antibodies, and transfer of immune regulators, cytokines and bioactive peptides. Unbiased estimates show that the human milk carries a complex community of microbiota which serves as the initial inoculum for establishment of infant gut. Our search effectively screened for evidence that shows that milk also harbours many types of prebiotics such as human milk oligosaccharides which encourage growth of beneficial probiotics. The milk also trains the naive immune system of the infant by supplying immune cells and stimulatory factors, thereby strengthening mucosal and systemic immune system. Our systematic review would improve understanding of human milk and the inherent complexity and diversity of human milk. The interrelated functional role of human milk components especially the oligosaccharides and microbiome has been discussed which plays important role in human health.

Impact of the 2017 ACC/AHA guidelines on the prevalence of hypertension among Indian adults: Results from a cross-sectional survey

Background

The impact of the 2017 American College of Cardiology (ACC)/American Heart Association (AHA) guidelines for diagnosis and management of hypertension on the prevalence of hypertension in India is unknown.

Methods

We analyzed data from the Cardiac Prevent 2015 survey to estimate the change in the prevalence of hypertension. The JNC8 guidelines defined hypertension as a systolic blood pressure of ≥140 ​mmHg or diastolic blood pressure of ≥90 ​mmHg. The 2017 ACC/AHA guidelines define hypertension as a systolic blood pressure of ≥130 ​mmHg or diastolic blood pressure of ≥80 ​mmHg. We standardized the prevalence as per the 2011 census population of India. We also calculated the prevalence as per the World Health Organization (WHO) World Standard Population (2000–2025).

Results

Among 180,335 participants (33.2% women), the mean age was 40.6 ​± ​14.9 years (41.1 ​± ​15.0 and 39.7 ​± ​14.7 years in men and women, respectively). Among them, 8,898 (4.9%), 99,791 (55.3%), 35,694 (11.9%), 23,084 (12.8%), 9,989 (5.5%) and 2,878 (1.6%) participants belonged to age group 18–19, 20–44, 45–54, 55–64, 65–74 and ​≥ ​75 years respectively. The prevalence of hypertension according to the JNC8 and 2017 ACC/AHA guidelines was 29.7% and 63.8%, respectively- an increase of 115%. With the 2011 census population of India, this suggests that currently, 486 million Indian adults have hypertension according to the 2017 ACC/AHA guidelines, an addition of 260 million as compared to the JNC8 guidelines.

Conclusion

According to the 2017 ACC/AHA guidelines, 3 in every 5 Indian adults have hypertension.

Cardiological society of India document on safety measure during echo evaluation of cardiovascular disease in the time of COVID-19

An echocardiographic investigation is one of the key modalities of diagnosis in cardiology. There has been a rising presence of cardiological comorbidities in patients positive for COVID-19. Hence, it is becoming extremely essential to look into the correct safety precautions, healthcare professionals must take while conducting an echo investigation. The decision matrix formulated for conducting an echocardiographic evaluation is based on presence or absence of cardiological comorbidity vis-à-vis positive, suspected or negative for COVID-19. The safety measures have been constructed keeping in mind the current safety precautions by WHO, CDC and MoHFW, India.

Cardiological Society of India: Document on acute MI care during COVID-19

The unprecedented and rapidly spreading Coronavirus Disease-19 (COVID-19) pandemic has challenged public health care systems globally. Based on worldwide experience, India has initiated a nationwide lockdown to prevent the exponential surge of cases. During COVID-19, management of cardiovascular emergencies like acute Myocardial Infarction (MI) may be compromised. Cardiological Society of India (CSI) has ventured in this moment of crisis to evolve a consensus document for care of acute MI. However, this care should be individualized, based on local expertise and governmental advisories.

A novel fabrication of electrospun polyacrylonitrile/NaYF4:Eu+3 light emitting nanofibers

Polyacrylonitrile/NaYF₄:Eu⁺³ nanophosphor composite nanofibers have been successfully prepared using the electrospinning technique. The electrospun nanofibers exhibited intense emission of gradient blue (X₂ = 0.254, Y₂ = 0.152 and X₃ = 0.233, Y₃ = 0.139) with different concentrations of nanophosphor under the excitation wavelength of 239 nm. The morphological and structural characterization of the nanofibers confirms the uniform dispersion of nanophosphor, while photoluminescence spectroscopy confirms tunability in luminescence properties.

Polyacrylonitrile/NaYF₄:Eu⁺³ nanophosphor composite nanofibers have been successfully prepared using the electrospinning technique.

A prospective study assessing feasibility of performing percutaneous nephrolithotomy in chronic kidney disease patients - What factors affect the outcome?

Objectives

To primarily evaluate the functional outcomes of PCNL for bilateral renal calculi/calculi in solitary functioning kidney with Chronic Kidney Disease(CKD). To identify factors affecting the renal replacement therapy following PCNL.

Materials and Methods

Patients with bilateral renal calculi/calculi in solitary kidney and CKD (eGFR<60/s.creatinine>2) and Good Performance Status [Eastern Cooperative Oncology Group (ECOG): 0–2] were included in the study.

Results

A total of 60 patients with CKD who had bilateral renal calculi/calculi in solitary functioning kidney underwent PCNL. At 6 months, eGFR improved or stabilized in 45 (75%) patients, while in 15 (25%) patients eGFR deteriorated. A total of 5 (14.28%) and 2 (25%) patients of CKD stage 4 and 5 respectively had improvement in eGFR as well as CKD stage. Fourteen (82.35%), 21 (60%), 3 (37.5%) patients of CKD stage 3, 4, 5 had improvement in eGFR but not significant enough to cause stage migration. Again 3 (17.65%) , 9 ( 40%) and 3 (37.5%) patients of CKD stage 3, 4, 5 had reduction in eGFR but not significant enough to cause stage migration. None of the patients had worsening of CKD stage. Preoperative CKD stage and eGFR were compared with measurements made at the final follow up visit (6 months).

Conclusion

Our results indicate that most patients of renal calculi with CKD show improvement or stabilization of renal function with aggressive stone removal. Improvement is more in patients who have mild to moderate CKD. Aggressive management of comorbidities, peri-operative UTI and complications may delay or avoid progression of CKD status in such patients.

Techniques for characterization and eradication of potato cyst nematode: a review

Correct identification of species and pathotypes is must for eradication of potato cyst nematodes (PCN). The identification of PCN species after completing the life cycle is very difficult because it is based on morphological and morphometrical characteristics. Genetically different populations of PCN are morphologically same and differentiated based on the host differential study. Later on these traditional techniques have been replaced by biochemical techniques viz, one and two dimensional gel electrophoresis, capillary gel electrophoresis, isozymes, dot blot hybridization and isoelectric focusing etc. to distinguish both the species. One and two dimensional gel electrophoresis has used to examine inter- and intra-specific differences in proteins of Globodera rostochiensis and G. pallida. Now application of PCR and DNA based characterization techniques like RAPD, AFLP and RFLP are the important tools for differentiating inter- and intra specific variation in PCN and has given opportunities to accurate identification of PCN. For managing the PCN, till now we are following integrated pest management (IPM) strategies, however these strategies are not effective to eradicate the PCN. Therefore to eradicate the PCN we need noval management practices like RNAi (RNA interference) or Gene silencing.

Complete mitogenome mapping of potato late blight pathogen, Phytophthora infestans A2 mating type

Complete mitochondrial genome of Phytophthora infestans, A₂ mating type (MT) with a size of ≅37,767 bp was sequenced. A total of 53 protein-coding genes are predicted on both strands, including 25 tRNA, 2 rRNA, and 18 respiratory proteins. Gene order of A₂MT was consistent with that established in A₁, despite high level of polymorphism in both coding and non-coding regions. The mtDNA of A₂MT was found to have 99.5% and 99.4% homology with Ia and Ib, whereas 94.7% and 94.3% with IIa and IIb, respectively. Study of repeats revealed a dinucleotide (AT)₉ specific to A₁ and homology of cox1 gene sequence revealed the relationship among 50 Phytophthora species.

Exciton Emission Intensity Modulation of Monolayer MoS2 via Au Plasmon Coupling

Modulation of photoluminescence of atomically thin transition metal dichalcogenide two-dimensional materials is critical for their integration in optoelectronic and photonic device applications. By coupling with different plasmonic array geometries, we have shown that the photoluminescence intensity can be enhanced and quenched in comparison with pristine monolayer MoS2. The enhanced exciton emission intensity can be further tuned by varying the angle of polarized incident excitation. Through controlled variation of the structural parameters of the plasmonic array in our experiment, we demonstrate modulation of the photoluminescence intensity from nearly fourfold quenching to approximately threefold enhancement. Our data indicates that the plasmonic resonance couples to optical fields at both, excitation and emission bands, and increases the spontaneous emission rate in a double spacing plasmonic array structure as compared with an equal spacing array structure. Furthermore our experimental results are supported by numerical as well as full electromagnetic wave simulations. This study can facilitate the incorporation of plasmon-enhanced transition metal dichalcogenide structures in photodetector, sensor and light emitter applications.

Population genetic structure of cotton pink bollworm, Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae) using mitochondrial cytochrome oxidase I (COI) gene sequences from India

Pink bollworm (PBW), Pectinophora gossypiella is one of the most destructive pest's globally inflicting huge economic losses in cotton even during later stages of crop growth. In the present investigation, the population genetic structure, distribution, and genetic diversity of P. gossypiella in cotton growing zones of India using partial mitochondrial DNA cytochrome oxidase-I (COI) gene was addressed. The overall haplotype (Hd), number of nucleotide differences (K), and nucleotide diversity (π) were 0.3028, 0.327, and 0.00047, respectively which suggest that entire population exhibited low level of genetic diversity. Zone-wise clustering of population revealed that central zone recorded low level of Hd (0.2730) as compared to north (0.3619) and south (0.3028) zones. The most common haplotype (H1) reported in all 19 locations could be proposed as ancestral/original haplotype. This haplotype with one mutational step formed star-like phylogeny connected with 11 other haplotypes. The phylogenetic relationship studies revealed that most haplotypes of populations are closely related to each other. Haplotype 5 was exclusively present in Dharwad (South zone) shared with populations of Hanumangarh and Bathinda (North zone). The result indicated that there is no isolation by distance effect among the Indian populations of PBW. The present study reports a low genetic diversity among PBW populations of India and H1, as ancestral haplotype from which other haplotypes have evolved suggests that the migration and dispersal over long distance and invasiveness are major factors.

Spatio-temporal variation in chemical characteristics of PM10 over Indo Gangetic Plain of India

The paper presents the spatio-temporal variation of chemical compositions (organic carbon (OC), elemental carbon (EC), and water-soluble inorganic ionic components (WSIC)) of particulate matter (PM10) over three locations (Delhi, Varanasi, and Kolkata) of Indo Gangetic Plain (IGP) of India for the year 2011. The observational sites are chosen to represent the characteristics of upper (Delhi), middle (Varanasi), and lower (Kolkata) IGP regions as converse to earlier single-station observation. Average mass concentration of PM10 was observed higher in the middle IGP (Varanasi 206.2 ± 77.4 μg m(-3)) as compared to upper IGP (Delhi 202.3 ± 74.3 μg m(-3)) and lower IGP (Kolkata 171.5 ± 38.5 μg m(-3)). Large variation in OC values from 23.57 μg m(-3) (Delhi) to 12.74 μg m(-3) (Kolkata) indicating role of formation of secondary aerosols, whereas EC have not shown much variation with maximum concentration over Delhi (10.07 μg m(-3)) and minimum over Varanasi (7.72 μg m(-3)). As expected, a strong seasonal variation was observed in the mass concentration of PM10 as well as in its chemical composition over the three locations. Principal component analysis (PCA) identifies the contribution of secondary aerosol, biomass burning, fossil fuel combustion, vehicular emission, and sea salt to PM10 mass concentration at the observational sites of IGP, India. Backward trajectory analysis indicated the influence of continental type aerosols being transported from the Bay of Bengal, Pakistan, Afghanistan, Rajasthan, Gujarat, and surrounding areas to IGP region.

Assessment of Bt trait purity in different generations of transgenic cottons

Adequate expression of Bt (Bacillus thuringiensis) toxins and purity of seeds of Bt-transgenic cottons are important for controlling bollworms, and thereby increasing the cotton productivity. Therefore, we examined the variability in expression of Bt toxin proteins in the seeds and in leaves of different cotton (Gossypium hirsutum (L.) hybrids (JKCH 226, JKCH 1947, JKCH Durga, JKCH Ishwar, JKCH Varun KDCHH 441 and KDCHH 621) expressing Bt toxins in F₁ and F₂ generations, using bioassays against the cotton bollworm, Helicoverpa armigera (Hübner), and the lateral flow strip (LFS) test. Toxicity of Bt toxin proteins in the seeds of Bt-transgenic cottons to H. armigera correlated with their toxicity in the leaves in one- toxin Bt cotton hybrids. The Bt-F₁ and Bt-F₂ seeds of JKCH 1947 were more toxic to H. armigera than those of JKCH Varun seeds. The seeds and leaves of F₁s showed greater toxicity than the F2 seeds or leaves of one-toxin (cry1Ac) Bt cotton hybrids. However, no significant differences were observed for the two-toxin (cry1Ac and cry2Ab) hybrid, KDCHH 621. Toxicity of leaves to H. armigera increased with crop age, until 112 days after seedling emergence. The Bt trait purity in F₁ seeds of four two-toxin Bt cotton hybrids ranged from 86.7 to 100%. The present study emphasizes the necessity of 95% Bt trait purity in seeds of transgenic cotton for sustainable crop production.

Efficacy of Mandibular 2-implant Overdenture: An Updated Meta-analysis on Patient-based Outcomes

The extent of heterogeneity regarding the efficacy of the mandibular 2-implant overdenture is still in question. The aim of this meta-analysis is to provide an update on the existing evidence from randomized controlled trials assessing the efficacy of the mandibular 2-implant overdenture in regard to patient-based outcomes. Electronic searches were carried out to September 2015 through MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, and the Cochrane Systematic Reviews. Only randomized controlled trials that compared conventional dentures with mandibular 2-implant overdentures were included. Patient-based outcomes were assessed, including patient satisfaction and oral health- and general health-related quality of life. Random effects models were used to pool the effect sizes of all included studies. Further stratified analyses and heterogeneity analyses were tested, as was publication bias. In addition to the 7 randomized controlled trials that were included in the previous meta-analysis, 4 new trials were identified and included in this update. A random effects model showed that, when compared with conventional dentures, mandibular 2-implant overdentures significantly improved patient satisfaction (pooled effect size = 0.87, z = 5.31, 95% confidence interval: 0.55 to 1.19, P < 0.0001, χ² = 41.82, df = 8, P < 0.0001, I² = 81%) and oral health-related quality of life (pooled effect size = -0.66, z = 2.72, 95% confidence interval: -1.13 to -0.18, P = 0.007, χ² = 21.26, df = 4, P = 0.0003, I² = 81%). The differences in participant recruitment and their pretreatment condition were important sources of heterogeneity among the studies. Only 1 study investigated the impact of mandibular implant overdentures on perceived general health, and it revealed no between-treatment differences. The 2-implant mandibular overdenture improves patient satisfaction and quality of life for the general edentate population. Health status, poor oral condition, and patient characteristics may effect patient-based outcomes and should be considered by clinicians in treatment planning. Knowledge Transfer Statement: This meta-analysis shows that mandibular 2-implant overdentures are significantly more satisfactory to the general edentate populations than new conventional dentures. The results also show that mandibular 2-implant overdentures provide significantly better oral health-related quality of life than do new conventional dentures. These results should be shared with edentate patients in planning their treatment.

Excellent mechanical properties of carbon fiber semi-aligned electrospun carbon nanofiber hybrid polymer composites

The excellent mechanical properties of carbon fiber fabric hybrid polymer composites is achieved by integrating continuous semi-aligned carbon nanofiber layers in the interlaminar region between carbon fiber fabric plies.

Variation of Stable Carbon and Nitrogen Isotopic Composition of PM10 at Urban Sites of Indo Gangetic Plain (IGP) of India

This paper presents the variation of elemental concentrations of total carbon (TC), total nitrogen (TN) and isotopic ratios of δ13C and δ15N along with δ13OC and OC of PM10 mass over Delhi, Varanasi and Kolkata of the Indo Gangetic Plain (IGP), India. For Delhi, the average concentrations of TC and TN of PM10 were 53.0±33.6 and 14.9±10.8 µg m(-3), whereas δ13C and δ15N of PM10 were -25.5±0.5 and 9.6±2.8‰, respectively. For Varanasi, the average values of δ13C and δ15N of PM10 were -25.4±0.8 and 6.8±2.4‰, respectively. For Kolkata, TC and TN values for PM10 ranged from 9.1-98.2 to 1.4-25.9 µg m(-3), respectively with average values of 32.6±24.9 and 9.3±8.2 µg m(-3), respectively. The average concentrations of δ13C and δ15N were -26.0±0.4 and 7.4±2.7‰, respectively over Kolkata with ranges of -26.6 to -24.9‰ and 2.8±11.5‰, respectively. The isotopic analysis revealed that biomass burning, vehicular emission and secondary inorganic aerosols were likely sources of PM10 mass over IGP, India.

STUDY OF SEGREGATING NATURE IN LIQUID Al-Ga ALLOYS

We report energetic of mixing behavior of liquid Al-Ga alloys, using simple statistical theory through concentration dependence thermodynamic, structural, transport and surface properties at 1023K. The concentration dependent thermodynamic functions (free energy of mixing, enthalpy of mixing, entropy of mixing and activity coefficient of the component), structural functions (concentration fluctuation in the long wavelength limit and chemical short range order parameter), transport properties (diffusivity and viscosity) and surface properties (surface segregation and surface tension) have got special attention to show a tendency of homo-coordination of atom in the mixture. The theoretical analysis reveals that input parameter, order energy is temperature dependent and Al-Ga alloys is of weakly interacting system.Scientific World, Vol. 12, No. 12, September 2014, page 14-20    

Host-mediated gene silencing of a single effector gene from the potato pathogen Phytophthora infestans imparts partial resistance to late blight disease

RNA interference (RNAi) has proved a powerful genetic tool for silencing genes in plants. Host-induced gene silencing of pathogen genes has provided a gene knockout strategy for a wide range of biotechnological applications. The RXLR effector Avr3a gene is largely responsible for virulence of oomycete plant pathogen Phytophthora infestans. In this study, we attempted to silence the Avr3a gene of P. infestans through RNAi technology. The P. infestans inoculation resulted in lower disease progression and a reduction in pathogen load, as demonstrated by disease scoring and quantification of pathogen biomass in terms of Pi08 repetitive elements, respectively. Transgenic plants induced moderate silencing of Avr3a, and the presence and/or expression of small interfering RNAs, as determined through Northern hybridization, indicated siRNA targeted against Avr3a conferred moderate resistance to P. infestans. The single effector gene did not provide complete resistance against P. infestans. Although the Avr3a effector gene could confer moderate resistance, for complete resistance, the cumulative effect of effector genes in addition to Avr3a needs to be considered. In this study, we demonstrated that host-induced RNAi is an effective strategy for functional genomics in oomycetes.

Enhanced up-conversion and temperature-sensing behaviour of Er(3+) and Yb(3+) co-doped Y2Ti2O7 by incorporation of Li(+) ions

Y2Ti2O7:Er(3+)/Yb(3+) (EYYTO) phosphors co-doped with Li(+) ions were synthesized by a conventional solid-state ceramic method. X-ray diffraction studies show that all the Li(+) co-doped EYYTO samples are highly crystalline in nature with pyrochlore face centred cubic structure. X-ray photon spectroscopy studies reveal that the incorporation of Li(+) ions creates the defects and/or vacancies associated with the sample surface. The effect of Li(+) ions on the photoluminescence up-conversion intensity of EYYTO was studied in detail. The up-conversion study under ∼976 nm excitation for different concentrations of Li(+) ions showed that the green and red band intensities were significantly enhanced. The 2 at% Li(+) ion co-doped EYYTO samples showed nearly 15- and 8-fold enhancements in green and red band up-converted intensities compared to Li(+) ion free EYYTO. The process involved in the up-conversion emission was evaluated in detail by pump power dependence, the energy level diagram, and decay analysis. The incorporation of Li(+) ions modified the crystal field around the Er(3+) ions, thus improving the up-conversion intensity. To investigate the sensing application of the synthesized phosphor materials, temperature-sensing performance was evaluated using the fluorescence intensity ratio technique. Appreciable temperature sensitivity was obtained using the synthesized phosphor material, indicating its applicability as a high-temperature-sensing probe. The maximum sensitivity was found to be 0.0067 K(-1) at 363 K.

Growth of dense CNT on the multilayer graphene film by the microwave plasma enhanced chemical vapor deposition technique and their field emission properties

Catalyst assisted carbon nanotubes (CNTs) were grown on multilayer graphene (MLG) on copper and silicon substrates by the microwave plasma enhanced chemical vapor deposition technique.

Color tuning in thermally stable Sm3+-activated CaWO4nanophosphors

Sm³⁺(Sm³⁺= 2, 5, 7 and 10 at%) doped CaWO₄nanophosphors exhibit a wide range emission in blue, green and red regions of the visible spectrum.

Retraction Note to: Pathogen virulence of Phytophthora infestans: from gene to functional genomics

[This retracts the article DOI: 10.1007/s12298-012-0157-z.].

Electroforming free high resistance resistive switching of graphene oxide modified polar-PVDF

A new model is proposed for high resistance resistive switching in polar beta-polyvinylidene fluoride and graphene oxide composites. The device achieved high resistance resistive switching in the range of 10–100 μA current without electroforming.