Corn cob nanocellulose packaging for increasing the shelf life of food products

Studies were carried out to develop eco-friendly Packaging material for the extended shelf-life of food products. The current study sought to improve the coated bioactive film's hydrophobicity and antimicrobial properties by preparing active packaging based on biodegradable Poly Lactic Acid (PLA) containing 1 wt% Nanocellulose (NC) and various loadings of essential oil-prepared nanocomposites. Nanocellulose (NC) from Maize Cob was used as filler in the synthesis of nanopolymers enriched with Thyme oil, Cinnamon oil, clove oil, and Rosemary oil. Characterization of nanopolymer-coated bags and their effect on enhancing the shelf-life of food products in different temperature conditions was also studied. The fabricated nanocomposite and nanocellulose were characterized using FTIR, SEM, XRD, Contact angle, TGA, and Tensile mechanical properties. The fabricated nanocomposite-coated paper cum bag shows good hydrophobic properties as well as antimicrobial and insecticidal properties. The results showed that adding essential oils and dispersing nanocellulose to the PLA matrix strengthened its mechanical qualities as well as its efficacy for biodegradation and antimicrobial properties. The current work provides extremely promising materials for future applications in food packaging applications using sustainable nanocomposite-based biodegradable and antimicrobial coated paper cum bags.

Effect of gamma-ray irradiated reduced graphene oxide (rGO) on environmental health: An in-vitro and in-vivo studies

The unique properties of reduced graphene oxide (rGO) have drawn the attention of scientists worldwide since the last decade and it is explored for a wide range of applications. However, the rapid expansion of rGO use in various products will eventually lead to environenal exposure and rises a safety concern on the environment and humal health risk. Moreover, the utilization of toxic chemicals for the reduction of graphene oxide (GO) into rGO is not environmentally friendly, warranting the exploration of non-toxic approaches. In the present work, rGO was synthesized using a different dose of gamma-ray irradiation and characterized. The in-vitro and in-vivo analysis indicated that the gamma-irradiated rGO induced toxicity depending on its degree of reduction and dosage. In the L929 cells, rGO-30 KGy significantly induced cytotoxicity even at low concentration (1 mg L^-1) by inducing reactive oxygen species (ROS), lactate dehydrogenase (LDH) enzyme production, nuclear fragmentation and apoptosis. The change in morphology of the cells like membrane blebbing and cell rounding was also observed via FESEM. In the in-vivo model Caenorhabditis elegans, rGO-30 KGy significantly affected the functioning of primary and secondary targeted organs and also negatively influenced the nuclear accumulation of transcription factors (DAF-16/FOXO and SKN-1/Nrf2), neuronal health, and antioxidant defense mechanism of the nematodes. The real-time PCR analysis showed significant up-regulation (ced-3, ced-4, cep-1, egl-1, and hus-1) and down-regulation (ced-9) of the gene involved in germ-line and DNA damage-induced apoptosis. The detailed toxicity mechanism of gamma irradiated rGO has been elucidated. This work highlights the toxicity of rGO prepared by gamma-ray radiation and paves way for understating the toxicity mechanism.

Benthic foraminifera as an environmental proxy for pollutants along the coast of Chennai, India

Benthic foraminifera are increasingly used as an indicator of environmental disturbance. Their sensitivities to pollutants can be reflected by changes in assemblage, which can provide useful information about ecosystem health. This study aimed to investigate the impact of organic and inorganic pollutants on the benthic ecology of the Chennai coast, with a focus on the 2017 oil spill caused by the collision of two ships. Sediment samples collected from five distinct zones along the coast were analysed for pollutants such as polycyclic aromatic hydrocarbons (PAHs), total petroleum hydrocarbons (TPH), heavy metals (Cr, Cd, Pb) and total organic carbon (TOC). The maximum concentrations of Cr (137 μg/g), Cd (6.93 μg/g) and Pb (34.2 μg/g), as well as TPH (84.3 μg/g) and PAHs (227 ng/g), were observed. A total of 47 species of foraminifera were identified in this study, of which 12 were morphologically abnormal. In the low-impact zone, the species diversity index (H') was higher. TPH and PAH concentrations were positively associated with abnormal species. Pollution-resistant foraminifera species include Ammonia tepida, Elphidium discoidale, and Quinqueloculina lamarckiana, while opportunistic foraminifera include Pararotalia curryi, Nonionella stella, Rosalina globularis, and Spirillina vivipara. PAHs and heavy metals were adversely correlated with foraminiferal abundance, while TPH was positively correlated. To assess the response of the benthic ecosystem to hydrocarbon pollution, indices such as the Foraminiferal Index of Environmental Impact (FIEI), Exponential (H'_bc) index and the Foraminiferal Abnormality Index (FAI) were used as environmental health proxies. FIEI, exp(H'_bc) and FAI values show the impact of hydrocarbon pollution to an extent along the northern Chennai coast.

One-step preparation of N-doped grapheme quantum dots with high quantum yield for bioimaging and highly sensitive electrochemical detection of isoniazid

Conventional techniques for synthesizing GQDs have a poor quantum yield (QY) that restricts their biological applications. Herein, we present a rapid, cost-effective and high quantum yield synthesis of nitrogen-doped graphene quantum dots (N-GQDs) through a scientific microwave reactor. The reaction parameters like microwave irradiation time, temperature, precursor concentration and pressure were optimized for achieving high quantum yield. The prepared N-GQDs exhibit bright blue fluorescence and excitation independent emission property with a quantum yield of 42.81%. In-vivo investigations on C. elegans revealed that the as-prepared N-GQDs are exceptionally biocompatible and maintain the normal physiological functioning of the primary and secondary targeted organs in nematodes. The synergetic effect of intestinal barrier and defecation behavior mitigates N-GQDs translocation into reproductive organs of nematode. In addition, the N-GQDs modified GCE was tested for electrochemical sensing characteristics towards the anti-tuberculosis drug isoniazid (INZ). The N-GQDs showed appreciable electrocatalytic performance towards INZ with high sensitivity (3.76 μA μM^-1 cm^-1). The differential pulse voltammetry (DPV) analysis of N-GQDs exhibit a lower detection limit of 10.91 nM for INZ. The N-GQDs modified sensor exhibits good reproducibility, excellent anti-interference ability and excellent analytical performance for INZ in real samples like human blood serum and urine samples.

Rapid one-pot synthesis of PAM-GO-Ag nanocomposite hydrogel by gamma-ray irradiation for remediation of environment pollutants and pathogen inactivation

Designing a cost-effective, high potential and recyclable catalyst remains a challenge. In the present work, a monolithic PAM-GO-Ag hydrogel is prepared by a facile, eco-friendly method using gamma-ray irradiation. The formation of GO-Ag composite by gamma radiation is also investigated and it is authenticated by XRD, FTIR, Raman, XPS and TEM analysis. The PAM-GO-Ag hydrogel exhibits excellent catalytic activity to different catalysant like methylene blue, Rhodamine-B, and pharmaceutical compound ciprofloxacin. The high catalyst carrying capacity and rapid electron shuttling ability of GO plays a significant role in the high performance of PAM-GO-Ag hydrogel. The PAM-GO-Ag hydrogel also exhibits excellent antibacterial activity. The damaged cell membrane, protein leakage, and increased ROS level contribute to the antibacterial activity of PAM-GO-Ag. The monolithic structure of PAM-GO-Ag hydrogel makes it easy to handle, recover, and reuse for several runs without significant loss of catalytic and antibacterial activity. All these results showed the possible application of PAM-GO-Ag hydrogel as a promising catalyst for the reduction of different pollutants and antibacterial agents on a large scale with good reusability.

Correction: NiCo2O4 nanoparticles inlaid on sulphur and nitrogen doped and co-doped rGO sheets as efficient electrocatalysts for the oxygen evolution and methanol oxidation reactions

[This corrects the article DOI: 10.1039/D1NA00135C.].

NiCo2O4 nanoparticles inlaid on sulphur and nitrogen doped and co-doped rGO sheets as efficient electrocatalysts for the oxygen evolution and methanol oxidation reactions

The present work depicts the fabrication of NiCo₂O₄ decorated on rGO, and doped and co-doped rGO and its electrocatalytic activity towards the oxygen evolution reaction and methanol oxidation reaction. The NiCo₂O₄ catalyst with S-doped rGO outperformed the other catalysts, indicating that the sulphur atoms attached on rGO possess low oxophilicity and optimum free energy. This results in facile adsorption of the intermediate products formed during the OER and a rapid release of O₂ molecules. The same catalyst requires an overpotential of 1.51 V vs. RHE to attain the benchmark current density value of 10 mA cm^-2 and shows a Tafel slope of 57 mV dec^-1. It also reveals outstanding stability during its operation for 10 h with a minimum loss in potential. On the other hand, NiCo₂O₄/S,N-rGO reveals superior activity with high efficiency and stability in catalyzing methanol oxidation. The catalyst delivered a low onset potential of 0.12 V vs. Hg/HgO and high current density of 203.4 mA cm^-2 after addition of 0.5 M methanol, revealing the outstanding performance of the electrocatalyst.

Enhanced electrochemical activities of morphologically tuned MnFe2O4 nanoneedles and nanoparticles integrated on reduced graphene oxide for highly efficient supercapacitor electrodes

The morphology of a nanoparticle strongly controls the path of electronic interaction, which directly correlates with the physicochemical properties and also the electrochemical comportment. Combining it with a two-dimensional (2D) material for a layer-by-layer approach will increase its possibilities in applications such as energy conversion and storage. Here, two different morphologies of MnFe₂O₄, nanoparticles and nanoneedles, are developed by a facile hydrothermal approach and sandwiched with reduced graphene oxide for constructing a 2D/3D sandwiched architecture. The rGO planar structure with abundant hierarchical short pores facilitates the thorough utilization of the utmost surface area to permeate the electrolyte within the structure to minimize the accumulation of rGO nanosheets laterally. The ferrite composited with rGO manifests high specific capacitance as the EDLC behaviour surpasses the faradaic pseudocapacitance boosting electrical conductivity compared to the as-synthesized MnFe₂O₄ structures. Benefiting from a 3D structure and the synergetic contribution of the MnFe₂O₄ nanoneedles and electrically conductive rGO layer, the MnFe₂O₄ nanoneedles@rGO electrode exhibits a high areal capacitance of 890 mF cm^-2 and a remarkable specific capacitance of 1327 F g^-1 at a current density of 5 mA cm^-2. 93.36% of the initial capacitance was retained after 5000 cycles in 1 mol L^-1 Na₂SO₄ indicating its high cycling stability. The synthesis route proves to be beneficial for a comprehensive yield of MnFe₂O₄@rGO nanosheets of different morphologies for use in the sophisticated design of energy-storing devices. This research strongly suggests that nanoparticle geometry, in addition to two-dimensional carbon-based materials, is a critical factor in a supercapacitor design.

Engineering the surface of graphene oxide with bovine serum albumin for improved biocompatibility in Caenorhabditis elegans

Graphene oxide (GO) has been extensively studied for its potential biomedical applications. However, its potential risk associated with the interactions of GO in a biological system hampers its biomedical applications. Therefore, there is an urgent need to enhance the biocompatibility of GO. In the present study, we decorated the surface of GO with bovine serum albumin (GO-BSA) to mitigate the in vivo toxic properties of GO. An in vivo model Caenorhabditis elegans has been used to study the potential protective effect of BSA decoration in mitigating GO induced toxicity. The BSA decoration on the surface of GO prevents the acute and prolonged toxicity induced by GO in primary and secondary organs by maintaining normal intestinal permeability, defecation behavior, development, and reproduction. Notably, GO-BSA treatment at 0.5-100 mg L^-1 does not affect the intracellular redox status and lifespan of C. elegans. Reporter gene expression analysis revealed that exposure to GO-BSA (100 mg L^-1) did not significantly influence the nuclear accumulation and expression patterns of DAF-16/FOXO and SKN-1/Nrf2 transcription factors and their downstream target genes sod-3, hsp-16.2, ctl-1,2,3, gcs-1, and gst-4 when compared to exposure to pristine GO. Also, quantitative real-time PCR results showed that GO-BSA did not alter the expression of genes involved in regulating DNA damage checkpoints (cep-1, hus-1 and egl-1) and core signaling pathways of apoptosis (ced-4, ced-3 and ced-9), in contrast to GO treatment. All these findings will have an impact on the future development of safer nanomaterial formulations of graphene and graphene-based materials for environmental and biomedical applications.

Marker Assisted Development and Characterization of Herbicide Tolerant Near Isogenic Lines of a Mega Basmati Rice Variety, "Pusa Basmati 1121"

BACKGROUND

Direct-seeded rice (DSR) is a potential technology for sustainable rice farming as it saves water and labor. However, higher incidence of weed under DSR limits productivity. Therefore, there is a need to develop herbicide tolerant (HT) rice varieties.

RESULTS

We used marker assisted backcross breeding (MABB) to transfer a mutant allele of Acetohydroxy acid synthase (AHAS) gene, which confers tolerance to imidazolinone group of herbicides from the donor parent (DP) "Robin" into the genetic background of an elite popular Basmati rice variety, Pusa Basmati 1121 (PB 1121). Foreground selection was done using the AHAS gene linked Simple Sequence Repeat (SSR) marker RM6844 and background selection was performed using 112 genome-wide SSR markers polymorphic between PB 1121 and Robin. Phenotypic selection for agronomic, Basmati grain and cooking quality traits in each generation was carried out to improve the recovery of recurrent parent phenome (RPP). Finally, a set of 12 BC₄F₄ near isogenic lines (NILs), with recurrent parent genome (RPG) recovery ranging from 98.66 to 99.55% were developed and evaluated. PB 1121-HT NILs namely 1979-14-7-33-99-10, 1979-14-7-33-99-15 and 1979-14-7-33-99-66 were found superior to PB 1121 in yield with comparable grain and cooking quality traits and herbicide tolerance similar to Robin.

CONCLUSION

Overall, the present study reports successful development of HT NILs in the genetic background of popular Basmati rice variety, PB 1121 by introgression of mutated AHAS allele. This is the first report on the development of HT Basmati rice. Superior NILs are being evaluated in the national Basmati trials, the release of which is likely to provide a viable option for the adoption of DSR technology in Basmati rice cultivation.

A nanocomposite of NiFe2O4-PANI as a duo active electrocatalyst toward the sensitive colorimetric and electrochemical sensing of ascorbic acid

A non-enzymatic ascorbic acid sensor using a nickel ferrite/PANI (NF-PANI) nanocomposite and based on colorimetric and electrochemical sensing methods was investigated in this study. The nanocomposite was prepared by an in situ polymerization and utilized as an electrocatalyst to sense ascorbic acid (AA) through the peroxidase mimic sensing of H₂O₂ in the presence of 3,5,3,5-tetramethylbenzidine (TMB) as a coloring agent. It was also utilized to detect AA present in real samples prepared from fruit extracts, commercial beverages, and vitamin-C tablets. The limit of detection (LoD) for AA sensing by the peroxidase mimic method was found to be 232 nM. The relative standard deviation (RSD) calculated for analysis of the real samples analysis ranged from 1.7-3.2%. Similarly, the electrochemical sensing of AA by NF-PANI was examined by cyclic voltammetric, chronoamperometric, and differential pulse voltammetric analyses. The LoD for the electrochemical method applied to AA sensing was 423 nM. The nanocomposite functioned as an effective electrocatalytic sensing agent in both methods to selectively detect AA due to the combined effect of NF and PANI. Thus, it was shown that the nanocomposites could be utilized for the laboratory-based detection of AA by various methods and could give rapid results.

Mesoporous nickel oxide nanostructures: influences of crystalline defects and morphological features on mediator-free electrochemical monosaccharide sensor application

Morphological and surface features are the key tools used to tune the catalytic performance of any metal oxide. In the present study, nickel oxide nanoparticles (NiO NPs) with three different morphologies were prepared using a simple hydrothermal method. The electrocatalytic performance of the prepared NiO NPs was evaluated with regard to the detection of monosaccharide glucose. The physicochemical properties of prepared NiO nanostructures were confirmed using different conventional characterization techniques. The flower-like morphological NiO NPs with nanosized petals have a high surface area and a more defective surface, resulting in improved heterogeneous catalytic activity compared to hexagonal and spherical morphological NiO NPs in glucose oxidation. The anionic and cationic vacancies on the mesoporous surface of NiO nanopetals endorsed an enhanced charge transfer efficiency compared to other NiO morphologies. The effect of scan rate, confirmed by cyclic voltammetry analysis, ensured the diffusion-controlled quasi-reversible electrochemical reaction between surface-modified electrodes and analyte. The NiO petals showed a wide linear detection range (100 nmol L^-1-12 mmol L^-1) and a lower detection limit of 57 nmol L^-1. In addition, the anti-interference ability, repeatability, stability and real sample analysis further affirmed the enhanced catalytic features of NiO nanopetals. The results showed that defective surfaces and surface features of the NiO nanostructures could be used to tune their overall sensor performance in future applications.

Magnetic graphene/chitosan nanocomposite: A promising nano-adsorbent for the removal of 2-naphthol from aqueous solution and their kinetic studies

In this study, magnetic/graphene/chitosan nanocomposite (MGCH) is prepared through facile solvothermal process and employed as an adsorbent for the removal of 2-naphthol from aqueous solution. The physico-chemical characteristic results of FESEM, Raman, FTIR, XRD and VSM confirms that the MGCH nanocomposite is effectively prepared. The FESEM and EDS analysis reveals that the high density of spherical-like Fe₃O₄ nanoparticles and chitosan are successfully assembled on the surfaces of the graphene sheets. VSM result of MGCH composite exhibited higher saturation magnetization of 46.5 emu g^-1 and lower coercivity (H_c) of 50 O_e. This result discloses that MGCH possesses enough response required for the separation from aqueous solution. The batch mode adsorption studies demonstrates that MGCH based adsorbent showed almost 99.8% adsorption of 2-naphthol with a maximum adsorption capacity of 169.49 mg g^-1 at pH 2. Moreover, the kinetic studies of the samples are performed by fitting adsorption models to ensure the nature of the adsorption system. This work proves that MGCH nanocomposite can be used as high-performance adsorbent for removing of phenolic pollutants from contaminated wastewater.

α-MoO3 nanostructure on carbon cloth substrate for dopamine detection

Orthorhombic molybdenum oxide (α-MoO₃) nanostructures were deposited on the surface of carbon cloth (CC) as a flexible and high conductive scaffold by reactive RF magnetron sputtering technique. Structure and morphology of the as prepared molybdenum coated carbon cloth (MoO₃CC) were thoroughly characterized with field emission scanning electron microscopy, x-ray diffraction, energy dispersive x-ray and Raman spectroscopy. Benefiting from high surface area and superior conductivity of CC as well as electrocatalytic activity of α-MoO₃ nanostructures, an electrochemical sensor was fabricated. The electrochemical behavior of this new sensor toward determination of dopamine was studied in detail by cyclic voltammetry, amperometry (AM) and square wave voltammetry (SWV). Results reported here reveal that using SWV not only enhances the sensitivity of sensors to dopamine by more than 14 times compared to AM, but also offers higher linear dynamic range (1-700 μM compared to 5-550 μM). Limit of detection, for signal to noise ratio 3, was calculated to be 0.48 μM. Applicability of the proposed sensor for measurement of dopamine in real samples, like urine and pharmaceutical formulation, was also evaluated that concluded to satisfactory results.

The natural diet of the mud crab Scylla olivacea (Herbst, 1896) in Pichavaram mangroves, India

Food and feeding habits of mud crab Scylla olivacea (Herbst, 1896) in Pichavaram mangroves was investigated quantitatively and qualitatively for a period of two years from June 2010 to May 2012. Gut contents from 1737 specimens comprising 843 males and 894 females in the size range between 45 mm and 148 mm were examined. Crustaceans form the predominant food item in a majority of size groups in terms of percentage wet weight and frequency of occurrence, while molluscs showed a preference in few size groups. The other dietary items includes fishes, detritus, mud and sand and miscellaneous. Gut content analysis revealed no significant variation between the quantities of food consumed by both sexes. Feeding intensity was higher in juveniles and subadults of both sexes than that of adults, revealing a greater preference to feed on fast moving prey such as crustaceans and fishes. The results of the present study indicate that S. olivacea in Pichavaram mangroves exhibited a clear preference for crustaceans.

Primary vaginal cancer: role of MRI in diagnosis, staging and treatment

Primary carcinoma of the vagina is rare, accounting for 1-3% of all gynaecological malignancies. MRI has an increasing role in diagnosis, staging, treatment and assessment of complications in gynaecologic malignancy. In this review, we illustrate the utility of MRI in patients with primary vaginal cancer and highlight key aspects of staging, treatment, recurrence and complications.

Edge-carboxylated graphene anchoring magnetite-hydroxyapatite nanocomposite for an efficient 4-nitrophenol sensor

Surface chemistry and electrochemical properties of ball milled edge-carboxylated graphene anchored with magnetite-hydroxyapatite nanocomposites were studied through the sensitive and selective detection of 4-NP by cyclic voltammetry and differential pulsed voltammetry.

Highly monodispersed Ag embedded SiO2 nanostructured thin film for sensitive SERS substrate: growth, characterization and detection of dye molecules

Highly monodispersed Ag embedded SiO₂ nanostructured thin films have been synthesized and their sensitivity towards SERS investigated.

Enzymatic electrochemical glucose biosensors by mesoporous 1D hydroxyapatite-on-2D reduced graphene oxide

A hydrothermally synthesized mesoporous 1D HAp-on-2D RGO sheets exhibiting direct electrochemistry of glucose biosensing.

Core–shell hydroxyapatite/Mg nanostructures: surfactant free facile synthesis, characterization and their in vitro cell viability studies against leukaemia cancer cells (K562)

Hydroxyapatite/magnesium core–shell nanostructures were synthesized by a simple and cost effective precipitation method without a surfactant or ligand/chelating agent.

Synthesis of hierarchical WO3 nanostructured thin films with enhanced electrochromic performance for switchable smart windows

Graphical representation of synthesis of hierarchical WO₃ nanostructured thin films via electrodeposition method.

Quercetin conjugated superparamagnetic magnetite nanoparticles for in-vitro analysis of breast cancer cell lines for chemotherapy applications

The magnetic nanoparticles attract increasing interest due to their opportunities in cancer therapy and used as drug carriers for several other diseases. The present study investigates the quercetin conjugated superparamagnetic Fe3O4 nanoparticles for in-vitro analysis of breast cancer cell lines for chemotherapy. A simple precipitation method was used to prepare the dextran coated Fe3O4 nanoparticles and the anticancer flavonoid quercetin was conjugated on the surface via carboxylic/amine group using nanoprecipitation method. The structural, morphological and the magnetic properties of the prepared materials were studied by using X-ray diffractometer (XRD), Fourier transformed infer-red spectrometer (FTIR), transmission electron microscope (TEM) and vibrating sample magnetometer (VSM). The MTT (3-(4,5-dimethylthiahiazol-2-yl)-2,5-diphenyl tetrazolium) assay of dextran coated Fe3O4 nanoparticles did not exhibit notable toxicity against MCF7 cells, whereas the cytotoxicity of quercetin conjugated Fe3O4 nanoparticles increased significantly in comparison with pure quercetin. The incubation of MCF-7 cells with quercetin conjugated Fe3O4 nanoparticles (QCMNPs) shows significant changes in cellular morphology observed through fluorescent microscopy. The results validate the prepared quercetin conjugated Fe3O4 nanoparticles are promising anticancer agents for targeted drug delivery.

Infestation of parasitic barnacle Sacculina spp. in commercial marine crabs

Commercial crab species infected of rhizocephalan cirripedes are reported from the coast of Parangipettai. Sacculina spp. were collected from brachyuran hosts Portunus sanquinolentus, Portunus hastatoides, Chaybdis feriatus, Charybdis variegate, Charybdis natator, Charybdis miles, Charybdis lucifera, Charybdis hoplites, Charybdis hellerii, Charybdis granulate, Charybdis amboinensis and Thalamita coeruleipes respectively.

Shape evolution and size controlled synthesis of mesoporous hydroxyapatite nanostructures and their morphology dependent Pb(ii) removal from waste water

Nanostructured hydroxyapatite with tunable morphologies was prepared by suitably adjusting the surfactants and used as an adsorbent for Pb(ii) from wastewater.

Facile in situ growth of Fe3O4 nanoparticles on hydroxyapatite nanorods for pH dependent adsorption and controlled release of proteins

The magnetic hydroxyapatite nanostructures were prepared by hydrothermal technique and studied their protein adsorption and in vitro cytotoxicity in humen MGC-803 cell.

Novel synthesis of silver nanoparticles using 2,3,5,6-tetrakis-(morpholinomethyl) hydroquinone as reducing agent

2,3,5,6-Tetrakis-(morpholinomethyl) hydroquinone (TMMH) was used as a reducing agent to synthesize spherical shaped silver nanoparticles in water-ethanol medium without using any stabilizing and capping agents. The reducing agent TMMH is prepared by Mannich-type reaction method and (1)H NMR, (13)C NMR and FT-IR spectroscopy techniques were used to characterize the compound (TMMH). The nature of bonding, structural and optical properties of the final product were analyzed using different techniques such as UV-Vis spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR). The interaction between silver and reducing agent was confirmed by using FTIR analysis. The final product obtained showed higher crystallinity with cubic structure and an average crystalline size of about 20 nm. The results revealed that it is possible to synthesize crystalline Ag nanoparticles using organic compound as reducing agent.

The reversed halo sign: update and differential diagnosis

The reversed halo sign is characterised by a central ground-glass opacity surrounded by denser air-space consolidation in the shape of a crescent or a ring. It was first described on high-resolution CT as being specific for cryptogenic organising pneumonia. Since then, the reversed halo sign has been reported in association with a wide range of pulmonary diseases, including invasive pulmonary fungal infections, paracoccidioidomycosis, pneumocystis pneumonia, tuberculosis, community-acquired pneumonia, lymphomatoid granulomatosis, Wegener granulomatosis, lipoid pneumonia and sarcoidosis. It is also seen in pulmonary neoplasms and infarction, and following radiation therapy and radiofrequency ablation of pulmonary malignancies. In this article, we present the spectrum of neoplastic and non-neoplastic diseases that may show the reversed halo sign and offer helpful clues for assisting in the differential diagnosis. By integrating the patient's clinical history with the presence of the reversed halo sign and other accompanying radiological findings, the radiologist should be able to narrow the differential diagnosis substantially, and may be able to provide a presumptive final diagnosis, which may obviate the need for biopsy in selected cases, especially in the immunosuppressed population.

Survival advantage associated with palliative oophorectomy in patients with metastatic colorectal cancer (CRC) to the ovaries (mCRC-O): A single institution retrospective analysis

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Background: The ovaries are an uncommon site for secondary spread from metastatic CRC. We hypothesize that palliative oophorectomy improves survival among patients with mCRC-O.

Methods: We undertook a single institution IRB-approved (DR-09-623) retrospective evaluation of women with mCRC-O from 2001-2008; 110 pts with ovarian metastases and follow-up information for survival analysis were identified out of 3,776 female pts with CRC (2.9%). Survival data was calculated from the date of diagnosis of ovarian metastases (by pathology or radiology) to date of death.

Results: Median age of patients was 49 years (range 19-82); median duration of follow-up was 49 months. Twenty patients were identified from 1,758 female patients with CRC seen at our institution from 2001-2004 (1.1%) and ninety patients identified from 2,018 female CRC patients from 2005-2008 (4.5%). KRAS mutation was present in the primary tumor in 23 of 43 (54%). Sixteen evaluable patients who received systemic chemotherapy with mCRC-O and other sites of metastatic disease were identified; five (31%) had a mixed radiographic response (progression in the ovarian metastases with disease response in other sites of metastases). Seventy-one (64.5%) patients had metastatic disease at the time of initial presentation; 39 (35.5%) had completely resected stage II or III CRC with mCRC-O occurring at a later date. 86 (78.2%) underwent unilateral or bilateral oophorectomy for treatment of their disease. Patients who had metastatic disease at presentation and underwent oophorectomy had a median survival of 39.4 months versus 18.2 months for those with ovarian metastases left in situ (p < 0.0001); patients who developed ovarian relapse after prior colectomy and subsequently underwent oophorectomy had a median survival of 50 months versus 12 months for those patients who did not (p = 0.001). Patients with mCRC-O and peritoneal metastases had a significantly worse survival (p = 0.003).

Conclusions: This single institution retrospective data analysis suggests that women with colorectal cancer metastatic to the ovaries may derive a survival benefit from palliative oophorectomy.

No significant financial relationships to disclose.

Molecular genetic analysis of cold-regulated gene transcription

Chilling and freezing temperatures adversely affect the productivity and quality of crops. Hence improving the cold hardiness of crop plants is an important goal in agriculture, which demands a clear understanding of cold stress signal perception and transduction. Pharmacological and biochemical evidence shows that membrane rigidification followed by cytoskeleton rearrangement, Ca(2+) influx and Ca(2+)-dependent phosphorylation are involved in cold stress signal transduction. Cold-responsive genes are regulated through C-repeat/dehydration-responsive elements (CRT/DRE) and abscisic acid (ABA)-responsive element cis elements by transacting factors C-repeat binding factors/dehydration-responsive element binding proteins (CBFs/DREBs) and basic leucine zippers (bZIPs) (SGBF1), respectively. We have carried out a forward genetic analysis using chemically mutagenized Arabidopsis plants expressing cold-responsive RD29A promoter-driven luciferase to dissect cold signal transduction. We have isolated the fiery1 (fry1) mutant and cloned the FRY1 gene, which encodes an inositol polyphosphate 1-phosphatase. The fry1 plants showed enhanced induction of stress genes in response to cold, ABA, salt and dehydration due to higher accumulation of the second messenger, inositol (1,4,5)- triphosphate (IP(3)). Thus our study provides genetic evidence suggesting that cold signal is transduced through changes in IP(3) levels. We have also identified the hos1 mutation, which showed super induction of cold-responsive genes and their transcriptional activators. Molecular cloning and characterization revealed that HOS1 encodes a ring finger protein, which has been implicated as an E3 ubiquitin conjugating enzyme. HOS1 is present in the cytoplasm at normal growth temperatures but accumulates in the nucleus upon cold stress. HOS1 appears to regulate temperature sensing by the cell as cold-responsive gene expression occurs in the hos1 mutant at relatively warm temperatures. Thus HOS1 is a negative regulator, which may be functionally linked to cellular thermosensors to modulate cold-responsive gene transcription.

Are our donors safe?

Blood is defined as a 'drug' under the Drugs and Cosmetics Act. The Standard of drugs is laid down in the Indian Pharmacopoeia. The first step towards blood safety is to encourage blood donations, which are voluntary, non-remunerated and obtained from low-risk and regular donors. A regular donor is one who donates blood two to three times a year and continues to donate at least once a year. Over the last 8 years, the Drug Control Authority has been taken up many steps to improve the quality of blood in circulation. As a result, blood centres are now equipped with minimum modern tests for making blood safer. The inspectors are also emphasising the need to employ uniform procedures for donor selection, donor deferral, validation of equipment, and so on. Over the last 5 years, quality control of diagnostic kits prior to their registration and marketing have been streamlined to ensure that blood centres use highly sensitive kits while testing for blood transmissible diseases. Therefore, current methods of donor screening and testing of donated blood have led to a remarkable decrease in the incidence of transfusion-transmitted infection and a blood supply that is very safe. The greatest threat to blood safety is donation by seronegative individuals during the infectious window period when they are undergoing seroconversion and infection cannot be detected by available laboratory tests. Look-backs is the process whereby blood collection facilities attempt to indentify prior recipients of blood donated by individuals who subsequently test positive TTD. This alone can assure safety.

Long-term assessment of efficacy and safety of L1, an oral iron chelator, in transfusion dependent thalassaemia: Indian trial

From August 1989 to May 1991, 52 patients with transfusion dependent thalassaemia major received L1 (1,2-dimethyl-3- hydroxypyrid-4-one), the oral iron chelator, for a period of 3-21 months (mean +/- SD: 14.2 +/- 6.8). Mean (+/- SD) urinary iron excretion varied from 6.2 +/- 4.6 mg/d on 25 mg/kg/d of L1 to 42.3 +/- 37.1 mg/d on 100 mg/kg/d of L1. Mean (+/- SD) drop in S ferritin was 1465 +/- 990 micrograms/l after 5.0 +/- 0.8 months to 3641.2 +/- 2299.3 micrograms/l after 20.1 +/- 0.9 months of therapy. There was no evidence of neutropenia, thrombocytopenia, ear or eye toxicity. L1-related arthralgia, which was reversible on dose reduction or stoppage, was seen in 20 patients (38.5%), while minor gastrointestinal (GI) tract symptoms occurred in seven (3.5%) cases. We conclude that although L1 is an effective iron chelator, further studies are required to understand the mechanism of L1 related arthralgia and also to find a safer but effective dose on which incidence of L1 related arthralgia is minimal.