Evaluation of carbon dioxide elevation on phenolic compounds and antioxidant activity of red onion (Allium cepa L.) during postharvest storage.

Carbon dioxide (CO2) is considered one of the eco-related key factors that negatively affect global climatic change. Also, CO2 can play an important role in the postharvest quality of the agri-products. In this study, the impact of CO2 on the quality of postharvest onions that were stored at 23 °C for 8 weeks was investigated. The weight loss, phenolic, flavonoid, flavanol, anthocyanin, antioxidant activity, and soluble sugar were analyzed during the study period. The results showed that 20% CO2 treatment was significantly (P > 0.05) more effective than 15% CO2 and control in inhibiting weight loss. Additionally, 20% CO2 treatment significantly retained higher antioxidant enzyme activities such as CAT, APX, and SOD than 15% CO2 and control. During storage, 20% CO2 treatment significantly (P < 0.05) improved glucose, fructose, and sucrose levels by more than 15% CO2 exposure and control groups. Besides the chlorogenic acid, kaempferol and quercetin were significantly (P < 0.05) higher in the 20% CO2 than in the 15% CO2 after 2 weeks of storage. In conclusion, this study's novelty comes from the broad prospects of using CO2 for maximizing the stored onion phytochemical functionality that is usually affected by the room temperature long storage. This will help in the onion shelf-life extension by considering the quality-related attributes.

Chemical aspects of polyphenol-protein interactions and their antibacterial activity.

The hunt for novel antibiotics has become a global public health imperative due to the rise in multidrug-resistant microorganisms, untreatable infection cases, overuse, and inefficacy of modern antibiotics. Polyphenols are getting much attention in research due to their multiple biological effects; their use as antimicrobial agents is attributed to their activity and that microbes have a hard time developing resistance to these natural compounds. Polyphenols are secondary metabolites produced in higher plants. They are known to possess various functional properties in the human body. Polyphenols also exhibit antibacterial activities against foodborne pathogens. Their antibacterial mechanism is based on inhibiting bacterial biofilm formation or inactivating enzymes. This review focused on polyphenol-protein interactions and the creation of this complex as a possible antibacterial agent. Also, different phenolic interactions on bacterial proteins, efflux pump, cell membrane, bacterial adhesion, toxins, and other bacterial proteins will be explored; these interactions can work in a synergic combination with antibiotics or act alone to assure bacterial inhibition. Additionally, our review will focus on polyphenol-protein interaction as a possible strategy to eradicate bacteria because polyphenols have shown a robust enzyme-inhibitory characteristic and a high tendency to complex with proteins, a response that neutralizes any bactericidal potential.

Phytostimulatory effect of silver nanoparticles (AgNPs) on rice seedling growth: An insight from antioxidative enzyme activities and gene expression patterns.

The knowledge on the mode of action, biocompatibility and ecological tolerance of silver nanoparticles (AgNPs) is gradually accumulating over the years with contradictory findings. Most of the studies indicated the toxic impact of AgNPs on plant growth and development, where induction of oxidative stress was considered to be one of the causal factors. The present study demonstrates the phytostimulatory effect of bio-synthesized silver nanoparticles (AgNPs) during seed germination and seedling growth of rice (Oryza sativa L., cv. Swarna) under in vitro condition. All the tested concentrations of AgNPs (10, 20, 40 ppm) promote both the shoot and root growth which was evident from the increased length and biomass of the seedlings. Exposure to AgNPs also significantly increased the chlorophyll a and carotenoid contents. The content and the pattern of distribution of phenolic metabolites among the different treatments are indicative of non-toxic impact of AgNP mimicking mild or no stress to the seedlings. Growth stimulation of rice seedlings by AgNPs was further supported by a low level of reactive oxygen species (ROS) concomitant with decreased amount of lipid peroxidation and H2O2 content, compared to control. In order to unravel the stimulatory impact of AgNPs on rice seedling growth, the present study also describes the AgNPs induced changes in antioxidative enzyme activity and related gene expression levels. Elevated levels of catalase (CAT), ascorbate peroxidase (APX) and glutathione reductase (GR) activities were recorded in all the AgNPs treated seedlings with improved growth. The activity of superoxide dismutase (SOD) was not significantly altered at low concentration of AgNPs. It appears that enzymes of ascorbate cycle, APX and GR are more active in ensuring protection against oxidative damage than SOD. There was significant up-regulation of CAT and APX gene expressions in seedlings exposed to AgNPs, whereas the expression level of CuZnSOD gene was decreased gradually with an increase in the concentration of AgNPs. The antioxidant enzyme activities and gene expression patterns coupled with the levels of H2O2 and lipid peroxidation indicates that the efficiency of redox reactions was increased in the presence of AgNPs and that accelerates the seedling growth.

Primary Sjögren's Syndrome Presenting as Flaccid Quadriparesis.

Primary Sjögren's syndrome is an autoimmune disease presenting classically as keratoconjunctivitis sicca. Renal involvement in Sjögrens's syndrome is less common, and the initial presentation with renal complications without any sicca symptoms is extremely rare. The renal involvement may present with symptoms arising from interstitial nephritis, mainly distal renal tubular acidosis.

Optical reflectionless potentials for broadband, omnidirectional antireflection.

Reflectionless potentials (RPs) represent a class of potentials that offer total transmission in the context of one dimensional scattering. An optical realization of RP can exhibit a truly broadband omni-directional antireflection. We report our experimental observations confirming the reflectionless behavior. Stratified media conforming to RP's are designed and fabricated using Al(2)O(3) and TiO(2) heterolayers. They showed < 0.5% reflection over the broad wavelength range of 350 nm to 2500 nm for angles of incidence 0 - 50 degrees. These RPs can be designed on substrates and are thus interesting for optical instrumentation as broadband, omni-directional antireflection coatings.

Two-photon quantum interference in plasmonics: theory and applications.

We report perfect two-photon quantum interference with near-unity visibility in a resonant tunneling plasmonic structure in folded Kretschmann geometry. This is despite absorption-induced loss of unitarity in plasmonic systems. The effect is traced to perfect destructive interference between the squares of amplitude reflection and transmission coefficients. We further highlight yet another remarkable potential of coincidence measurements as a probe with better resolution as compared to standard spectroscopic techniques. The finer features show up in both angle resolved and frequency resolved studies.

Mushroom tyrosinase inhibition activity of Aloe vera L. gel from different germplasms.

In this study, lyophilized and methanolic extracts of aloe gel from different germplasms were evaluated for their potential to inhibit mushroom tyrosinase activity. The results showed potent inhibitory effect of Aloe vera gel extracts on L-dihydroxyphenylalanine (L-DOPA) oxidation catalyzed by tyrosinase in a dose-dependent manner. Significant differences in % inhibition of tyrosinase among the extraction methods and the germplasms were observed. The relative performance of the germplasms was evaluated with the help of posthoc multicomparison test. The methanolic extract was more effective than the lyophilized crude gel in all the germplasms. The inhibitory effect of the lyophilized gel and methanolic extract tested from five germplasms followed the order: RM > TN > S24 > OR > RJN. The germplasm RM showed the highest tyrosinase inhibition, and the maximum % inhibition noted was 26.04% and 41.18%, respectively for the lyophilized and methanolic extracts at 6 mg · mL(-1) concentration. Lineweaver-Burk plots of the different concentrations of L-DOPA in the absence and presence of lyophilized gel extract showed competitive inhibition of mushroom tyrosinase in all the germplasms. This study suggests that the germplasm RM could potentially be used for the isolation and identification of the effective tyrosinase inhibitory component, and ascertains the critical role of selecting the best source of germplasm for natural product isolation and characterization.

Strong coupling of in-plane propagating plasmon modes and its control.

We show anti-crossings due to strong in-plane coupling of grating excited propagating plasmon modes in dielectric-metal-dielectric structure with 2D dielectric pattern on top. Grating coupled propagating plasmon modes along with their complete dispersion in the measurement range and all different sample orientations are calculated first. Further a coupled mode theory is presented for the specific geometry presented here. Experimentally measured anti-crossing widths are compared with those calculated by coupled mode theory. It is shown that the coupling strength of the plasmon modes and thus the anti-crossing width can be controlled by the orientation of the sample.

Follicular dendritic cell sarcoma with paraneoplatic pemphigus: Rare case and a brief review of literature.

Paraneoplastic pemphigus (PNP) is often a fatal autoimmune bullous disease characterized by severe stomatitis, polymorphous skin eruptions, and underlying neoplasms. We describe a patient with PNP associated with follicular dendritic cell sarcoma (FDCS), a rare neoplasm originating from follicular dendritic cells, which are non-lymphoid, non-phagocytic accessory cells of the lymphoid system and play an integral role in regulation of the germinal center reaction and present antigens to B-cells. The presence of rich vascularity around the tumor and few hyalanized vascular follicles found in histopathological examination gives the clue that the tumor might have developed from Castleman's disease (CD). As for the mechanisms by which CD induces PNP, it has been proposed that autoantibodies secreted from the Castleman's tumor play pivotal role. This hypothesis seems to be supported by the present case, in which CD may have triggered both the FDCS and the PNP.

Controllable coherent perfect absorption in a composite film.

We exploit the versatility provided by metal-dielectric composites to demonstrate controllable coherent perfect absorption (CPA) or anti-lasing in a slab of heterogeneous medium. The slab is illuminated by coherent light from both sides, at the same angle of incidence and the conditions required for CPA are investigated as a function of the different system parameters. Our calculations clearly elucidate the role of absorption as a necessary prerequisite for CPA. We further demonstrate the controllability of the CPA frequency to the extent of having the same at two distinct frequencies even in presence of dispersion, rendering the realization of anti-lasers more flexible.

Matrix supported liquid culture and machine vision analysis of regenerated shoots of gladiolus.

Enhancement of efficiency and efficacy of plant regeneration are primary goals of micropropagation. An efficient method with rapid and improved shoot regeneration of gladiolus based upon matrix supported liquid culture technique has been demonstrated. This technique in addition ensured the quality of the regenerated shoots by effectively alleviating the phenomenon of hyperhydricity. Efficacy in plant regeneration can be brought about by the ability to sort and objectively select plants or group of plants with a desired feature. A reliable, noninvasive, machine vision-neural network based sorting method for clustering photometric variants of regenerated shoots of gladiolus has also been described.

HIV-1 genome-encoded hiv1-mir-H1 impairs cellular responses to infection.

The recent discovery of HIV-1 genome-encoded novel microRNA (miRNA; designated as hiv1-mir-H1) having ability to target selectively and specifically human cellular AATF gene, prompted us to explore the role of this miRNA in the regulation of genes involved in cellular apoptosis, proliferation and nucleic acid-based immune mechanism governed by miRNAs. Such a study revealed that this miRNA-induced knockdown of AATF gene, within normal human blood mononuclear cells, was responsible for the suppression of genes coding for Bcl-2, c-myc, Par-4 and Dicer. Further, hiv1-mir-H1 had the capacity to downregulate expression of cellular miR149 gene recognized to target Vpr gene encoded by HIV-1. Based upon these findings, we propose an "Epigenomic Pathway" through which hiv1-mir-H1 induced AATF gene knockdown within human mononuclear cells initiates their apoptosis.

Strong-interaction-mediated critical coupling at two distinct frequencies.

I study a multilayered medium consisting of a metal-dielectric composite film, a spacer layer, and a dielectric Bragg reflector. I demonstrate a greater flexibility over the critical coupling phenomenon [Tischler et al., Opt. Lett. 31, 2045 (2006)], whereby nearly all the incident light energy is absorbed by the composite film through suppression of both transmission and reflection from the structure. For a larger volume fraction of the metal inclusions, strong light-matter coupling is shown to lead to almost total absorption at two distinct frequencies.

Transrectal ultrasound-guided biopsy of prostate voxels identified as suspicious of malignancy on three-dimensional (1)H MR spectroscopic imaging in patients with abnormal digital rectal examination or raised prostate specific antigen level of 4-10 ng/ml.

Results of the evaluation of transrectal ultrasound (TRUS) guided needle biopsy of voxels identified as suspicious of malignancy on magnetic resonance spectroscopic imaging (MRSI) in a large cohort of men (n = 83) with abnormal digital rectal examination (DRE) [prostate specific antigen (PSA) 0-4 ng/ml] or PSA less than 10 ng/ml, are reported. Three-dimensional (1)H MRSI was carried out at 1.5 T using a pelvic-phased array coil in combination with an endorectal surface coil. Voxels were classified as suspicious of malignancy based on Cit/(Cho + Cr) metabolite ratio. TRUS-guided biopsy of suspicious voxels was performed using the z- and x-coordinates obtained from MR images and two to three cores were taken from the suspected site. A systematic sextant biopsy was also carried out. MRSI showed voxels suspicious of malignancy in 44 patients while biopsy revealed cancer in 11 patients (25%). Patients who were negative for malignancy on MRSI were also negative on biopsy. An overall sensitivity of 100%, specificity of 54%, negative predictive value of 100% and accuracy of 60% were obtained. The site of biopsy was confirmed (n = 20) as a hypo-intense area on repeat MRI while repeat MRSI revealed high choline and low citrate. The overall success rate of MRI-directed TRUS-guided biopsy of 25% was higher compared with a 9% success rate achieved without MR guidance in another group of 120 patients. Our results indicate that TRUS-guided biopsy of suspicious area identified as malignant from MRSI can be performed using the coordinates of the voxel derived from MR images. This increases the detection rate of prostate cancer in men with PSA level <10 ng/ml or abnormal DRE and also demonstrates the potential of MR in routine clinical practice.

Apparent diffusion coefficient of the prostate in men prior to biopsy: determination of a cut-off value to predict malignancy of the peripheral zone.

Determination of the apparent diffusion coefficient (ADC) of the prostate in men (n = 60) with raised prostate-specific antigen (PSA) or an abnormal digital rectal examination (DRE) prior to transrectal ultrasound (TRUS) guided biopsy using endorectal DWI is reported. Patients were categorized into different groups based on their PSA levels. The mean ADC was calculated from a number of regions of interest (ROIs) for the whole of the peripheral zone (PZ) and the central gland (CG). A total of 1108 ROIs were analyzed from 60 patients. The mean ADC value of the PZ was higher than that of the CG in controls. A total of 23 out of 60 patients were positive for malignancy on biopsy, and the mean ADC of the PZ was lower in these patients compared with those who were negative. Moreover, the mean ADC obtained for the whole of the PZ of the prostate in different groups of patients and controls showed a decreasing trend. A plot between PSA and mean ADC for the PZ showed non-linear association with logarithmic decrease in ADC. The mean ADC of the CG was not significantly different in patients who were positive or negative for malignancy in biopsy. In addition, a cut-off value of 1.17 x 10(-3) mm2/s (sensitivity = 73% and specificity = 74%, area under the curve = 0.83) for the mean ADC for the whole of the PZ of patients was determined by using the receiver operating characteristic curve (ROC) to predict malignancy of the PZ.

Arsenic-induced cell death in liver and brain of experimental rats.

Arsenic is a well established human carcinogen and is ubiquitous in the environment. The present study demonstrates the effect of acute arsenic administration at three different doses in liver and brain of Wistar rats. Sodium arsenite was administered orally at doses of 6.3 mg/kg, 10.5 mg/kg and 12.6 mg/kg of body weight on the basis of a lethal dose 50% (LD50) for 24 hr. After administration of arsenites, liver and brain were analyzed for various parameters of oxidative stress, histopathological changes and caspase-3 activity. Glutathione levels were decreased significantly in the liver at all doses. In liver the following biochemical changes were observed, a significant lipid peroxidation and cytochrome-P450 induction along with significant decrease in catalase and superoxide dismutase was observed at 10.5 mg/kg and 12.6 mg/kg. The activity of glutathione peroxidase was increased significantly at all doses. In brain, no significant change was observed at 6.3 mg/kg. However, a significant increase in lipid peroxidation and glutathione peroxidase activity along with significant decrease in the activity of glutathione, catalase and superoxide dismutase was observed at 10.5 mg/kg and 12.6 mg/kg. The activity of glutathione-S-transferase was decreased significantly in both liver and brain at 10.5 and 12.6 mg/kg. No significant alteration in the activity of glucose-6-phosphate dehydrogenase and glutathione reductase was observed in either liver or brain at any dose. Dose-dependent histopathological changes, observed in both liver and brain are also described. A significant increase in caspase-3 activity was observed at all doses in liver and at 10.5 and 12.6 mg/kg in brain. Sodium arsenite caused DNA cleavage into fragments and manifested as "DNA laddering", a hallmark of apoptosis.

Multiple extranodal sites at presentation in non-Hodgkin's lymphoma.

About one-third of NHL patients present lymphomas at extranodal sites. Involvement of multiple noncontiguous extranodal sites at presentation without lymph node involvement is unknown. Herein we present two such cases. The first patient had sinonasal tract and urinary bladder NHL at presentation, while the other patient presented with bilateral adrenal involvement in addition to sinonasal tract NHL. Clinical presentation and pathophysiology are discussed, and a brief review of literature is included.

Reciprocity relations for reflected amplitudes.

We derive general reciprocity relations that are applicable to a large class of one-dimensional stratified systems. These results reveal clearly the role of absorption and spatial symmetry in the nonreciprocity of reflection observed in a recent experiment by Armitage et al. [Phys. Rev. B 58, 15, 376 (1998)]. We also present examples of structures for which such nonreciprocal effects can be significant.