Dengue is a serious global health concern especially in tropical and subtropical countries. About 2.5 billion of the world’s population is at risk for dengue infection. Early diagnosis is the key to ...prevent the deterioration of health of the patient to severe illness. Laboratory diagnosis of dengue is essential for providing appropriate supportive treatment to dengue patients with febrile illness, which is difficult to diagnose clinically. Here, we demonstrate surface enhanced Raman scattering (SERS) based diagnosis of dengue virus in clinical blood samples collected from total of 102 subjects. All of the samples were well characterized by conventional NS1 antigen and IgM antibody ELISA kits. The silver nanorods array fabricated by glancing angle deposition technique were employed as SERS substrates. A small amount of patient blood serum (5 μL) was taken for analysis and the report was prepared within a minute. SERS spectra of pure NS1 protein as well as spiked in serum was also recorded separately. Principal component analysis (PCA) was employed as the statistical tool to differentiate dengue positive, dengue negative, and healthy subjects on the basis of their respective SERS spectra. This method provides a sensitive, rapid, and field deployable diagnosis of dengue at the early stage (within 5 days of the onset of symptoms).
Here, we present a portable, selective and cost-effective fiber-optic surface plasmon resonance (SPR) based platform for early detection of Dengue virus. NS1 protein was targeted as the biomarker of ...dengue. Antibody-antigen specific binding was exploited for NS1 antigen detection. The binding of antibody was assisted by a self-assembled monolayer of alkanethiols on the surface of silver-coated unclad fiber. A wavelength interrogation mode of SPR was utilized to detect NS1 antigen in the dynamic range of 0.2–2.0 μg/ml. The 40 nm thick silver coated optical fiber exhibited resonance wavelength around 500 nm and change in resonance wavelength was monitored for each attachment step on the fiber. The sensitivity at the lowest concentration of NS1 antigen was found to be 54.7 nm/(μg/ml). The limit of detection of the sensor was found to be 0.06 μg/ml, which lies in the physiological range of NS1 protein present in the infected blood, hence the present technique may provide a very early detection advantage. Real blood serum samples were also successfully tested on the set-up, confirming compatibility with the conventional methods. The presented field-deployable platform has wide applications in mass monitoring of dengue, such as during outbreaks and epidemics.
•A portable fiber optic-SPR platform demonstrated for early stage Dengue detection.•Antibody-antigen specific binding was utilized for selective detection of NS1 antigen.•A mixed self-assembled monolayer (1-HT + 11-MUA) immobilized to bind anti-NS1 antibody.•The probe was also tested on clinical NS1 positive blood samples.•The sensitivity and limit of detection were determined to be 54.7 nm/(μg/ml) and 0.066 μg/ml respectively.
Noble metal nanostructures are known to confine photon energies to their dimensions with resonant oscillations of their conduction electrons, leading to the ultrahigh enhancement of electromagnetic ...fields in numerous spectroscopic methods. Of all the possible plasmonic nanomaterials, silver offers the most intriguing properties, such as best field enhancements and tunable resonances in visible-to-near infrared regions. This review highlights the recent developments in silver nanostructured substrates for plasmonic sensing with the main emphasis on surface plasmon resonance (SPR) and surface-enhanced Raman spectroscopy (SERS) over the past decade. The main focus is on the synthesis of silver nanostructured substrates via physical vapor deposition and chemical synthesis routes and their applications in each sensing regime. A comprehensive review of recent literature on various possible silver nanostructures prepared through these methodologies is discussed and critically reviewed for various planar and optical fiber-based substrates.
Legume crops provide significant nutrition to humans as a source of protein, omega-3 fatty acids as well as specific macro and micronutrients. Additionally, legumes improve the cropping environment ...by replenishing the soil nitrogen content. Chickpeas are the second most significant staple legume food crop worldwide behind dry bean which contains 17%–24% protein, 41%–51% carbohydrate, and other important essential minerals, vitamins, dietary fiber, folate, β-carotene, anti-oxidants, micronutrients (phosphorus, calcium, magnesium, iron, and zinc) as well as linoleic and oleic unsaturated fatty acids. Despite these advantages, legumes are far behind cereals in terms of genetic improvement mainly due to far less effort, the bottlenecks of the narrow genetic base, and several biotic and abiotic factors in the scenario of changing climatic conditions. Measures are now called for beyond conventional breeding practices to strategically broadening of narrow genetic base utilizing chickpea wild relatives and improvement of cultivars through advanced breeding approaches with a focus on high yield productivity, biotic and abiotic stresses including climate resilience, and enhanced nutritional values. Desirable donors having such multiple traits have been identified using core and mini core collections from the cultivated gene pool and wild relatives of Chickpea. Several methods have been developed to address cross-species fertilization obstacles and to aid in inter-specific hybridization and introgression of the target gene sequences from wild
Cicer
species. Additionally, recent advances in “Omics” sciences along with high-throughput and precise phenotyping tools have made it easier to identify genes that regulate traits of interest. Next-generation sequencing technologies, whole-genome sequencing, transcriptomics, and differential genes expression profiling along with a plethora of novel techniques like single nucleotide polymorphism exploiting high-density genotyping by sequencing assays, simple sequence repeat markers, diversity array technology platform, and whole-genome re-sequencing technique led to the identification and development of QTLs and high-density trait mapping of the global chickpea germplasm. These altogether have helped in broadening the narrow genetic base of chickpeas.
In wheat, a major yield QTL (
Qyld.csdh.7AL
) contributing ~ 20% to the variation for grain yield under drought was introgressed into each of the four Indian wheat cultivars (HUW234, HUW468, K307 and ...DBW17) with an objective to develop high yielding drought tolerant genotypes. The marker
Xwmc273.3
linked to the yield QTL was used for marker assisted foreground selection, which was followed by phenotypic selection leading to the development of 55 advanced lines. These lines were evaluated during the crop seasons 2015–2016 and 2016–2017 under irrigated and rainfed conditions at two locations (Meerut and Niphad), which differed for agro-climatic conditions. Under irrigated condition at Niphad, three lines gave 14.9–25.7% higher yield relative to the corresponding genotypes HUW234 and DWB17 that were used for introgression. Similarly, under rainfed condition at Meerut, one line gave 25.5% higher yield relative to the corresponding genotype HUW234. The high yield in the selected lines was attributed to number of grains per ear, grain weight, tiller number, biomass and lower canopy temperature. The line giving higher yield under rainfed condition also had low stress sensitivity index suggesting its ability to tolerate water-stress. The high yielding lines may be used for testing in a variety development programme. The study is yet another example of the successful use of MAS in combination with phenotypic selection for development of high yielding wheat genotypes for rainfed and irrigated conditions.
In this study, a low‐melting organic‐inorganic crystalline ionic liquid compound, N‐butyl pyridinium tetrachlorido ferrate (III) is described. The material can easily be synthesized using a one‐pot ...approach in an ionic liquid medium. Single‐crystal X‐ray diffraction confirms that the basic inorganic block is FeCl4−, which is counterbalanced by an N‐butyl pyridinium cation. The compound exhibits a melting point of 37.6 °C by differential scanning calorimetry, which is among the lowest values for a pyridinium‐based metal‐containing ionic liquid. The material shows promising electrochemical behavior at room temperature in both aqueous and nonaqueous solvents, and at elevated temperatures in its pure liquid state. Given its appreciable solubility in both water and acetonitrile, the compound can act as a redox‐active species in a supporting electrolyte for redox flow battery applications. These classes of low‐melting ionic solids with long‐range order and interesting electrochemical applications are potential candidates for a range of green energy storage and harvesting systems.
A low‐melting organic‐inorganic crystalline solid C4PyFeCl4 is synthesized and a detailed structural, thermal, and optical analysis is performed. The relatively simple inorganic building block of FeCl4‐ provides interesting electrochemical properties in both water and acetonitrile. In a proof‐of‐concept study C4PyFeCl4 is shown to act as a redox‐active species as a negolyte for redox flow battery applications.
Abiotic stresses in wheat, particularly drought (DR), hamper wheat production and causes up to 86% yield losses. Therefore, developing stress-tolerant genotypes is a major challenge in wheat ...breeding. In this study, we evaluated 72 diverse wheat genotypes for DR tolerance over two consecutive years, examining 12 morpho-physiological traits under irrigated (IR) and DR conditions. Under DR, grain yield (GY) was significantly associated with biomass and phenological traits. The principal component analysis accounted for 82.79% and 80.08% of the overall variation during IR and DR stress conditions, respectively. Based on GY component traits and drought susceptible index, two tolerant (IC36761A and IC128335) and two susceptible (IC138852 and IC335732) genotypes were selected for physio-biochemical analysis. In these genotypes, the membrane stability index (MSI) ranged from 57 to 74% and 35 to 64% under IR and DR conditions. Genotype IC128335 showed 78.10% relative water content (RWC), 2.97 mg/g tannin, and 3.67 mg/g fresh weight reducing sugar (RS) content under DR conditions. Abscisic acid (ABA) content ranged from 0.81 to 4.03 ppm/g dry weight (DW) and 0.92–4.23 ppm/g DW under IR and DR stress conditions, respectively. There was a significant genotype × environment interaction observed for the physio-biochemical traits. The genotypes IC36761A and IC128335 suffered less reduction in MSI and RWC. RS and flavonoid content significantly increased in all four genotypes, but the tannin and ABA levels increased especially in IC128335 and IC36761A under DR conditions. The physio-biochemical findings support the DR tolerance of genotypes IC128335 and IC36761A, indicating their potential for inclusion in breeding programs aimed at enhancing DR tolerance in bread wheat.
A
bstract
The cross section for coherent photonuclear production of J/
ψ
is presented as a function of the electromagnetic dissociation (EMD) of Pb. The measurement is performed with the ALICE ...detector in ultra-peripheral Pb-Pb collisions at a centre-of-mass energy per nucleon pair of
s
NN
= 5.02 TeV. Cross sections are presented in five different J/
ψ
rapidity ranges within |
y
| < 4, with the J/
ψ
reconstructed via its dilepton decay channels. In some events the J/
ψ
is not accompanied by EMD, while other events do produce neutrons from EMD at beam rapidities either in one or the other beam direction, or in both. The cross sections in a given rapidity range and for different configurations of neutrons from EMD allow for the extraction of the energy dependence of this process in the range 17 <
W
γ
Pb
,
n
< 920 GeV, where
W
γ
Pb
,
n
is the centre-of-mass energy per nucleon of the
γ
Pb system. This range corresponds to a Bjorken-
x
interval spanning about three orders of magnitude: 1.1 × 10
−
5
<
x
< 3.3 × 10
−
2
. In addition to the ultra-peripheral and photonuclear cross sections, the nuclear suppression factor is obtained. These measurements point to a strong depletion of the gluon distribution in Pb nuclei over a broad, previously unexplored, energy range. These results, together with previous ALICE measurements, provide unprecedented information to probe quantum chromodynamics at high energies.
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