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Periorbital melanosis (POM) has a significant impact on quality of life. There is a dearth of literature regarding POM, especially in Asian population. Accurate classification of POM is contributory to the choice of therapy. The aim of this study was to assess the role of dermoscopy in etiologic classification of POM.Two hundred and fifty adult patients (age 18 years) of POM were enrolled over a period of 2 years. POM was classified clinically and re-evaluated based on their dermoscopic findings (pattern of pigmentary and vascular involvement, surface changes).Pigmented, vascular, structural, and mixed types of POM represented 6.4%, 4.8%, 0.4%, and 88.4%, respectively. Dermoscopy was found to be statistically more accurate in classifying pigmentary and vascular types of POM as compared to clinical examination with the naked eyes (p- value0.05). Patchy or post-inflammatory pigmentation was the most common pigmentary pattern on dermoscopy (53.8%) followed by pseudoreticular (37.1%) and mixed pattern (9.1%). 80.4% patients had vascular involvement of which the most common vascular pattern was telangiectasia (58.8%). Wrinkling or increased skin laxity as a cause of shadow effect was found in 52% patients. Diffuse erythema and scaling suggestive of subtle inflammation was detected in 47.6% patients on dermoscopy.Dermoscopy as a diagnostic modality is more accurate in detecting pigmentary and vascular causes of POM and subtle signs of active inflammation in the form of erythema and scaling which is difficult to detect clinically. The major limitations of this study were lack of correlation of dermoscopic findings with the histological findings and the absence of any control group for comparison.

Subcutaneous zygomycosis is a rare fungal infection caused by Basidiobolus ranarum. This entity is usually endemic in South India and only limited numbers of cases have been reported from central India. We report a case of 4-year-old male child from Chhattisgarh, who presented with a painless, non-tender, large, subcutaneous swelling of 4 months duration on the right upper arm, which was initially misdiagnosed as benign spindle cell tumor and advised surgical resection. But the fungal culture of the affected tissue grown Basidiobolus ranarum and the child responded very well to itraconazole therapy only. Keywords: Basidiobolus ranarum, Subcutaneous zygomycosis, Fungal infection, Spindle cell tumor, Itraconazole therapy

Deformities and disabilities in leprosy lead to significant morbidity to the individual and financial burden to the family. As the prevalence of leprosy is higher in central India, this study was conducted to know the burden of deformity and disability among leprosy patients in central India and the factors associated with it.This was a hospital-based, cross-sectional study, conducted on 50 new or on treatment or released from treatment leprosy patients, attending the Dermatology OPD of a tertiary care institute in Central India. Disability was graded as per the WHO criteria for disability grading of hands and feet.Grade 2 disability was found among 32% of the patients with leprosy, whereas a total of 60% of our patients had either grade 1 or grade 2 disabilities. Trophic ulcer was found among 20% and claw hand among 14% of leprosy patients. We found significant associations of lepromatous leprosy with trophic ulcer (p = 0.004) and grade 2 disability (p = 0.012). All patients with claw hands and 80% of the patients with trophic ulcers presented to the healthcare facility at least 6 months after the onset of symptoms.We found very high rates of disability and deformity among leprosy patients indicating possible huge burden of morbidity among leprosy patients in central India. The significant association of lepromatous leprosy with trophic ulcer and grade 2 disability indicated delayed presentation and diagnosis of lepromatous leprosy patients. Our results underlined the need for large scale community-based studies on disability and deformity among leprosy patients in Central India. These results also call for better training of primary level healthcare workers for early detection and management of deformities and disabilities as well as better patient education for leprosy patients regarding hand and foot care.

The type of packaging used for food products is an essential component in the extension of their shelf life, their quality and nutritional value, and their protection from contaminants, moisture, and bacteria. Because of the emergence of drug-resistant pathogenic strains, food packaging is increasingly important in protecting consumers from diseases. Moreover, the food industry has grown exponentially overtime and has suffered huge economic losses and contributed to loss of life due to food spoilage and foodborne pathogens. Novel packaging technologies are being explored that hold the potential to develop more eco-friendly, more economic, safer, and longer storage characteristics. The research and industrial sectors are focusing strongly on ways to enhance consumer safety through sustainable and smart packaging. Silver nanoparticles (AgNPs) have opened up new areas of research and are an important factor in the evolution of the global food packaging industry, and already a wide range of AgNPs have been examined in regard to minimizing both the risk of food spoilage and the effects of emerging foodborne pathogens. This chapter reviews a broad range of AgNPs as key antimicrobial components in smart and active packaging and also highlights AgNPs’ antimicrobial mechanisms and the current status and challenges related to nano‑silver-based packaging and the related regulations.

MtrR is a negative regulator of MtrCDE efflux pump. Various N-Terminal and C-Terminal mutations have been reported in different multidrug resistant clinical isolates of Neisseria gonorrhoeae across the world. Mutations in N-terminal region of MtrR, are known to abrogate its binding with the promoter thereby providing an evidence that this region encodes for DNA binding domain. In contrast, mechanism of action of mutations in C-terminal, known to play a role in protein dimerization and has site for ligand binding, is left unexplored. In the present study, using in silico approach, we observed that H105Y mutation affects the conformation of the protein and its binding with penicillin. Purified, recombinant wild type and mutant MtrR were compared for their binding to promoter region and various antibiotics. Fluorescence spectroscopy, CD spectroscopy and dynamic light scattering assay with wild type and mutant MtrR suggested decreased binding of H105Y MtrR with its promoter without affecting protein dimerization, but due to altered conformation of mutant dimer. Our in silico results also suggest altered conformation of the mutant dimer protein leading to difference in the posture of homodimer formed and hence altered binding with DNA. Mutant protein also showed stronger binding with various antibiotics: penicillin, ceftriaxone and ofloxacin. Binding of drugs also leads to altered conformation of the protein which may lead to its decreased binding with the promoter DNA.ImportanceMutations in MtrR, a transcriptional repressor of MtrCDE efflux pump have been reported in various multi-drug resistant Neisseria gonorrhoeae across the world. We identified that a C-terminal mutation H105Y, outside the DNA binding domain of MtrR, decreases the binding of MtrR with its promoter. We identified that the mutation alters the structure of the dimer, as well as enhances the antibiotic binding. We envisage that the altered structure of MtrR affects its DNA binding thereby increasing efflux of antibiotics and increased resistance. These findings could be used as a guide to design novel drugs that should either not bind to MtrR or could surpass the conformational change and decreased DNA binding.

Emergence of antimicrobial drug-resistance amongst food-borne pathogens has led to severe deficit of available therapeutics and requires novel interventions. This study determined the activity of vitamin C (VitC), a natural antioxidant as powerful antibacterial agent against multidrug-resistant (MDR), biofilm-forming E. coli. Our findings revealed that VitC wield antibacterial action in dose-time dependent manner with minimum inhibitory concentration (MIC) of 125 mM. At these concentrations VitC impaired quorum sensing (QS) and exopolysaccharide (EPS) production and induced sugar and protein leakage from the bacterial cells by virtue of reactive oxygen species (ROS) generation. Furthermore, VitC-treated bacteria showed downregulation of genes underpinning biofilm signaling (luxS) and regulation (bssR) by up to 27-folds. Finally, this study demonstrated the promising antimicrobial application of VitC, in situ, in Indian soft cheese (paneer) when applied as a coating. Therefore, VitC can be applied as natural and safe ‘antimicrobial’ against biofilm-forming bacteria in food systems vis-a-vis other conventional antimicrobials.

The massive use of synthetic citric acid (CA) has resulted in huge burden on its disposal from the expired food and pharmaceutical products. Adsorption of CA was investigated over aminopropyl functionalized ordered mesoporous silica (SBA/APTS) by varying different parameters wherein the best optimized condition showed up to 95% CA adsorption. Electron microscopy showed the presence of CA adsorbed sites over functionalized silica, further supported by thermogravimetric and volumetric analysis. Under the best optimized condition, the mechanism of adsorption was also proposed. Separation of CA over SBA/APTS from expired lime juice showed 40% removal capacity. The adsorption measurements were best fitted on Langmuir isotherm model with maximum adsorption capacity as 133.34 mg of CA per g of adsorbate (SBA/APTS).

An efficient, mild catalyst was employed for the synthesis of dihydropyrimidinones via condensation of aldehyde, ethyl acetoacetate, and urea/thiourea in the presence of silica polymer nanocomposite functionalized with polyphosphoric acid. The present methodology offers an advantage of being mild and highly selective wherein a three-component reaction proceeds proficiently because of the synergistic role of the hydrophobic polymer and the acidic sites functionalized on silica, which allows easy removal of water molecule formed during the reaction.

Deoxycholic acid is a secondary bile acid produced in the intestine that is involved in dietary fat digestion and results in lysis of adipocytes when injected into subcutaneous tissue. ATX-101 (Kybella, Allergan, Irvine, CA) is an injectable nonanimal and nonhuman formulation of deoxycholic acid. Th

A 30 years old, strictly vegetarian male presented with generalized weakness, weight loss, and gradually progressing cutaneous hyperpigmentation. On examination, pigmentation was more pronounced on sunexposed areas, flexural folds, and palmar creases along with mucosal involvement in the form of glossitis and pallor. Laboratory investigations revealed megaloblastic anaemia and low vitamin B12 level, thereby confirming the diagnosis of vitamin B12 deficiency. The treatment consisted of vitamin B12 supplementation. Vitamin B12 deficiency may occur due to malabsorption (due to pernicious anemia or gastric resection) and rarely, due to inadequate intake (almost exclusively in strict vegetarians). Cutaneous manifestations due to vitamin B12 deficiency manifest early and have diagnostic importance, thus allowing timely diagnosis and prevention of late neurological and other systemic complications.

Mutations in PenA, PorB, MtrE and MtrR genes responsible for antimicrobial resistance were checked in 27 drug-resistant clinical isolates of Neisseria gonorrhoeae (NG). Phenotype PIB (88.88%) and mutation at G120 and A121 positions of porB were recurrent. N122K, a novel mutation, was observed in PorB in three resistant isolates. Substitution H105Y in MtrR was widespread (37% of clinical isolates). The presence of a novel mutation (L33V), along with G45D mutation in MtrR, was associated with less-resistant isolates, in contrast to isolates with G45D mutation alone. African-type penicillinase-producing NG plasmid was observed most frequently (17/27) in penicillin-resistant isolates.

The currently available nucleic acid amplification tests (NAATs) for trichomoniasis are accurate, quick and confirmative with superior sensitivity than traditional culture-based microbiology assays. However, these assays are associated with problems of carry over contamination, false positive results, requirement of technical expertise for performance and detection of end product. Hence, a diagnostic assay with easy visualization of the amplified product will be profitable. An in-house, rapid, sensitive, specific molecular-beacon-based PCR assay, using primers against pfoB gene of Trichomonas vaginalis, was developed and evaluated using dry ectocervical swabs (n=392) from symptomatic females with vaginal discharge. Total DNA was isolated and used as template for the PCR assays. The performance and reproducibility of PCR assay was evaluated by composite reference standard (CRS). For easy visualization of the amplified product, molecular-beacon was designed and amplicons were visualized directly using fluorescent handheld dark reader or by Micro-Plate Reader. Molecular-beacons are single-stranded hairpin shaped nucleic acid probes composed of a stem, with fluorophore/quencher pair and a loop region complementary to the desired DNA. The beacon-based PCR assay designed in the present study is highly specific as confirmed by competition experiments and extremely sensitive with detection limit of 20fg of genomic DNA (3-4 pathogens). The minimum infrastructure requirement and ease to perform the assay makes this method highly useful for resource poor countries for better disease management.

Onion being a semi-perishable horticultural bulb crop gets subjected to deterioration during the storage, which ultimately leads to huge monetary losses every year. Specific detection tools for onion spoilage will be an asset in relieving losses during post-harvest storage. In this context silver based yellow colored colloidal nanoparticle (AgY-NPs) solution was synthesized and evaluated as a visual sensor for the organo-sulfur compound released during the spoilage of onions. The visual changes during the spoilage was monitored for ten days wherein the yellow color of the AgY colloidal solution changed to orange, pink and finally turned transparent. Simultaneous analysis carried out by UV–Vis spectroscopy and colorimeteric analysis corroborates our investigation of AgY-NPs as a visual sensor displaying selectivity and specificity for volatile sulphur compound responsible for spoilage of onions. Furthermore, analysis of AgY-NPs in presence of healthy onions showed distinct visual results which were complemented by probable mechanism. Besides this the structural changes in AgY-NPs due to incorporation of sulphur compounds were supported by Powder X-ray diffraction (PXRD), Raman Analysis, Fourier Transform-Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) which clearly indicated the capacity of these AgY-NPs as a powerful detection tool for onion spoilage.

Escherichia coli are commensal gastrointestinal microflora of humans, but few strains may cause food-borne diseases. Present study aimed to identify antimicrobial resistant (AMR), biofilm-forming E. coli from Indian dairy and meat products. A total of 32 E. coli isolates were identified and evaluated for biofilm-formation. EMC17, an E. coli isolate was established as a powerful biofilm-former that attained maximum biofilm-formation within 96 h on glass and stainless-steel surfaces. Presence and expression of virulence-associated genes (adhesins, invasins and polysaccharides) and ability to adhere and invade human liver carcinoma HepG2 cell lines implicates EMC17 to be pathotype belonging to Extra-intestinal Pathogenic E. coli (ExPEC). Antibiotic profiling of EMC17 identified it as multi-drug resistant (MDR) strain, possessing extended spectrum β-lactamases (ESBL's) and biofilm phenotype. Early production of quorum sensing molecules (AHLs) alongside EPS production facilitated early onset of biofilm formation by EMC17. Furthermore, the biofilm-forming genes of EMC17 were significantly upregulated 3–27 folds in the biofilm-state. This study showed prevalence of MDR, biofilm-forming, pathogenic E. coli in Indian dairy and meat products that potentially serve as reservoirs for transmission of antimicrobial-resistant (AMR) genes of bacteria from food to humans and pose serious food safety threat.

In the current scenario, nanotechnological applications in the agriculture sector showing potential impacts on the improvement of plant growth in terms of protection and safety are at a very nascent stage. The present study deals with the synergistic role of zinc (Zn) and multiwalled carbon nanotubes (MWCNTs) synthesized as a zinc oxide (ZnO)/MWCNT nanocomposite, a prospective applicant to modulate the micronutrient supply and enhance the growth of onion seeds, thereby replacing harmful, unsafe chemical fertilizers. To the best of our knowledge, this is the first report wherein MWCNTs have been envisaged as a micronutrient distributor and a nutrient stabilizer enhancing the growth of onion plant under arid conditions. The growth trend of onion seeds was evaluated in an aqueous medium with varied concentrations of (i) MWCNTs, (ii) zinc oxide nanoparticles, and (iii) ZnO/MWCNT nanocomposites. ZnO/MWCNT nanocomposites with 15 μg/mL concentration displayed the best seedling growth with the maximum number of cells in telophase. A significant growth trend with increased concentration of ZnO/MWCNTs displayed no negative impact on plant growth in contrast to that with the use of MWCNTs. The synergistic impact of Zn nanoparticles and MWCNTs in ZnO/MWCNT nanocomposites on the rate of germination was explained via a mechanism supported by scanning transmission electron microscopy.

Objective. The development of an accurate, sensitive, specific, rapid, reproducible, stable-at-room-temperature and cost-effective diagnostic kit, and a low-cost portable fluorescence detector to fulfil the requirements of diagnostic facilities in developing countries. Methods. We developed the ‘Chlamy and Ness CT/NG kit’ based on molecular beacons for the detection of Chlamydia trachomatis (CT) and Neisseriagonorrhoeae (NG). Multi-centric evaluation of the CT/NG kit was performed using the commercially available nucleic acid amplification test (NAAT)-based FTD Urethritis basic kit for comparison from December 2014 to November 2016. The stability of the kit reagents at 4 and 37 ˚C and the inter-day reproducibility of results were also analysed. Results. The sensitivity and specificity of the kit were found to be 95.83 and 100.00 % for the detection of C. trachomatis and 93.24 and 99.75 % for N. gonorrhoeae, respectively, when tested against the commercial kit. The positive predictive value (PPV) was 100.00 and 98.57 %, whereas the negative predictive value (NPV) was 99.54 and 98.79 % for C. trachomatis and N. gonorrhoeae, respectively. Analysis of the kappa statistics enhanced the ‘inter-rater’ κ=0.976 for Chlamydia and κ=0.943 for Neisseria. Conclusion. Our kit was found to be as sensitive and specific as commercially available kits. Its low cost and ease of use will make it suitable for the routine diagnosis of C. trachomatis and N. gonorrhoeae in the resource-limited settings of developing countries.

High performance in PEM fuel cells has been achieved using purified CNTs as catalyst support. Pt/CNT nanocomposites were synthesized by reducing Pt salt on CNTs in the presence of ethylene glycol as solvent and in inert atmosphere. The reactions were carried out using both pristine and purified MWCNTs under different pH and atmospheric conditions. The detailed physical and electrochemical characterization revealed that a highly active catalytic surface could be achieved on reducing Pt on defect-free, purified MWCNTs. A further elaborated mechanism is discussed, which illustrates that reduced Pt nanoparticles form a chelate in the presence of nitrogen at neutral pH. This results in increased stability and enhanced catalytic activity. The I–V performance of a unit PEM fuel cell using the synthesized catalyst (with purified CNTs as catalyst support) showed a peak power density of 818 mW cm−2. The performance repeated in triplicate was found to be consistent and exceptionally high (>80%) in comparison with 448 mW cm−2, the value obtained while employing pristine CNTs as support and tested under similar conditions. Moreover, a novel experimental support was given to confirm the number of electrons involved in the oxygen reduction reaction (ORR) on these highly purified CNT supported catalysts.

Ferulic acid (FA) functionalized ordered mesoporous silica (SBA/FA) nanocomposites were synthesized via in situ radical polymerization of vinyl monomers for the adsorption of Cr(VI) toxic ions. Powder X-ray diffraction and N2 adsorption isotherms showed the presence of mesoporous nature of the nanocomposites after functionalization with FA. Different adsorption parameters such as adsorption weight, adsorption time, pH etc. were optimized for adsorption of Cr(VI) ions under environmental friendly conditions. The adsorption studies results showed high adsorption of functionalized nanocomposites (100–172 mg/g) compared to SBA-15 (60 mg/g) materials.

Ordered mesoporous silica SBA-15 functionalized with piperazine (SBA/Pip) was synthesized via grafting method. Incorporation of piperazine inside the mesopores without affecting the stability of the ordered mesoporous silica could be viewed from different characterization techniques such as Powder X-ray diffraction, N2 sorption studies, Fourier-Transform Infrared spectroscopy, Scanning Electron microscopy, Transmission Electron Microscopy. The SBA/Pip nanocomposite was employed as an electrochemical sensor to detect the presence of ascorbic acid ranging from millimolar to nanomolar range via differential pulse voltammetry (DPV) in the potential window of −1.5 to +1.5 V wherein the scan rate was maintained at 4 mV/s. Further SBA/Pip displayed selective detection of ascorbic acid in packed and fresh orange juice without any interference from other acids like citric acid commonly present in packed juice.

Mesoporous silica–polymer nanocomposites (SBA/PS) synthesized via wet impregnation method were functionalized by mild polyphosphoric acid (PPA) for catalytic applications. The catalysts were characterized and analysed by powder X-ray diffraction (PXRD), solid state nuclear magnetic resonance (31P-SSNMR), N2-adsorption–desorption isotherm, Fourier transform-infrared (FT-IR), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HR-TEM) and thermogravimetric analysis (TGA/DTA). The catalytic studies of a multicomponent Mannich reaction was conducted wherein the hydrophobic nature of these nanocomposites showed an enhancement in the product activity and selectivity of β-amino carbonyl (Mannich base) compounds. The probable reaction mechanism elucidates the role of well-distributed active sites on the hydrophobic surface and the stability of the catalyst for good catalytic activity.

Neisseria gonorrhoeaeis an important sexually transmitted diseases (STD) causing pathogen worldwide. Due to absence of an affordable diagnostic assay, routine screening of gonococcal infection becomes impossible in developing countries where infection rates are maximum. Treatment is given on the basis of symptoms alone which leads to spread of infection. Thus, development of a rapid, sensitive, specific, and PCR based visual diagnostic assay suitable for developing countries, required for better disease management, is aimed at in present study. Endocervical swabs were collected from patients visiting gynecology department of various hospitals in Delhi. In-house PCR based assay was developed and modified to visual assay using molecular beacon for end-point detection. It was evaluated against Roche AMPLICOR NG kit andrmpgene. Specificity of beacon was confirmed by competition experiments. Diagnostic test was 98.21% specific and 99.59% sensitive whereas negative and positive predicted value were 99.40% and 98.78%, respectively. We also observed that twice the concentration (2X) of premix was stable at 4°C for 4 months and dry swab samples gave concordant results with that of wet swabs. These features make the test best suitable for routine diagnosis of genital infections in developing countries.

The sperm DNA integrity post cryopreservation of human semen samples is one of the serious concerns in human infertility treatment. In the present study, the beneficial effects of zinc oxide nanoparticles in preserving the functional ability of spermatozoa was explored. Ejaculates of normozoospermic men cryopreserved along with Zinc oxide nanoparticles (ZnONPs) exhibited non-significantly higher percentage of total and progressive motility in frozen-thawed samples compared to control. The sperm chromatin damage and malondialdehyde (MDA) level was significantly lower in ZnONPs group (P < 0.01 and P < 0.05 respectively) and the spermatozoa's ability to undergo acrosome reaction was also unaltered. Fluorescence microscopy and High resolution transmission electron microscopy analysis demonstrated that the ZnONPs do not penetrate the membrane of spermatozoa but stay around the spermatozoa. In conclusion, the presence of ZnONPs during cryopreservation appears to be beneficial to the spermatozoa as they withstand freeze-thaw process competently better than control, without any adverse effect shown.

Mutations in PenA, PorB, MtrE and MtrR genes responsible for antimicrobial resistance were checked in 27 drug-resistant clinical isolates of Neisseria gonorrhoeae (NG). Phenotype PIB (88.88%) and mutation at G120 and A121 positions of porB were recurrent. N122K, a novel mutation, was observed in PorB in three resistant isolates. Substitution H105Y in MtrR was widespread (37% of clinical isolates). The presence of a novel mutation (L33V), along with G45D mutation in MtrR, was associated with less-resistant isolates, in contrast to isolates with G45D mutation alone. African-type penicillinase-producing NG plasmid was observed most frequently (17/27) in penicillin-resistant isolates.

Silica polymer nanocomposites were synthesized via in situ free radical polymerization of vinyl monomers inside mesoporous silica frame work for their potential use in adsorption of bovine serum albumin (BSA). Powder X-ray diffraction studies and adsorption isotherm studies confirmed the mesoporous nature of the nanocomposites. Very high adsorption (6.5–14.2 mg/g) of BSA was observed for functionalized ordered silica nanocomposites (SBA/x). Various adsorption parameters such as adsorbent weight, adsorption time and pH etc. were optimized and possible synergism of hydrophilic/hydrophobic interactions was also discussed.

We present a first report on the use of Langmuir Blodgett (LB) technique for the synthesis of edge decorated graphene oxide gold (GO–Au) nanostructures by simple manipulation of electrostatic interactions. The GO–Au nanostructures when characterized using spectroscopy, surface, chemical and micro structural techniques, displayed unique physical and structural properties. The results re-established the theoretical corroboration that the carboxyl groups are primarily located at the edges of the 2D sheets of GO. The exploitation of air–water interface platform makes this process novel and fundamentally different from existing protocols for synthesis of GO–metal composites. These GO–Au hybrid materials favoured visible-light driven plasmonic photo catalysis together with enhanced charge separation and transportation properties, resulting in the augmentation of photocatalytic activity and conductivity with high transmittance. A plausible reaction mechanism for the degradation of pollutant dye and the role of gold nanoparticles (NPs) on GO has been established.

Cellular neurothekeoma is a rare cutaneous tumor that occurs more frequently in women. A 68-year-old female with a history of left nasal alar basal cell carcinoma and Guillain-Barré syndrome presented to the clinic with a 3-mm firm skin-colored papule with scattered telangiectasias. Histopathologic examination with immunochemistry of the lesion was consistent with cellular neurothekeoma. It stained positive for microphthalmia transcription factor and NKI-C3 and negative for HMB-45 and S-100. The lesion was excised with 3-mm margins, and no recurrence was noted within 1 year of follow-up. We present a case of cellular neurothekeoma in a patient with a history of Guillain-Barré syndrome as well as a review of the literature. Our case report is unique in that no prior association has been found in the literature between cellular neurothekeoma and Guillain-Barré syndrome. © 2014 S. Karger AG, Basel

We present a pioneer study depicting a significant improvement in the photoluminescence (PL) intensity and display of an expeditious electro-optic response of ferroelectric liquid crystal (FLC) when doped with graphene quantum dots (GQDs). Significant threefold enhancement in PL intensity of GQDs/FLC composite material can be ascribed to the additive combination of emissions from GQDs and FLCs. Furthermore, promptness in electro-optical response by a factor of 34% can be attributed to the lowering of rotational viscosity of the FLC material due to the incorporation of GQDs. These results would certainly be helpful in realisation of highly luminescent and faster generation of LC systems.

Sulfosuccinic acid functionalized mesoporous silica (SBA/SSA) was synthesized and characterized for debenzylation of vanillic acid in liquid phase for the first time. The catalytic activity studies showed high activity (82%) and selectivity (96%) for the desired product vanillic acid over SBA/SSA compared to 74% selectivity over silica/SSA. Synergistic effects of acidic/basic groups responsible for higher activity and selectivity were explained with plausible mechanism.

Chlamydia trachomatis(CT) is an important cause of sexually transmitted genital tract infections (STIs) and trachoma. Despite major research into chlamydial pathogenesis and host immune responses, immunoprotection has been hampered by the incomplete understanding of protective immunity in the genital tract. Characterized vaccine candidates have shown variable efficacy ranging from no protection to partial protectionin vivo. It is therefore a research priority to identify novel chlamydial antigens that may elicit protective immune responses against CT infection. In the present study we assessed the seroprevalence of antibodies against protein kinase1 (Pkn1), DNA ligaseA (LigA), and major outer membrane protein A (OmpA) following natural CT infection in humans and in experimentally induced CT infection inMacaca nemestrina. Antigenic stretches of Pkn1, LigA, and OmpA were identified using bioinformatic tools.Pkn1,LigA, andOmpAgenes were cloned in bacterial expression vector and purified by affinity chromatography. Our results demonstrate significantly high seroprevalence of antibodies against purified Pkn1 and OmpA in sera obtained from the macaque animal model and human patients infected with CT. In contrast no significant seroreactivity was observed for LigA. The seroprevalence of antibodies against Pkn1 suggest that nonsurface chlamydial proteins could also be important for developing vaccines forC. trachomatis.

Silica-polyphosphoric acid nanocomposites (SBA/PPA) were synthesized via direct and post-functionalization of ordered mesoporous SBA-15 materials with PPA. The catalytic studies for acylation of naphthalene in the liquid phase showed very high selectivity of 2-acylated product (A) over direct functionalized SBA/PPA nanocomposites.

Nanofibers, also known as solid fibers, consist of several remarkable nanoscale features. These are basically porous structures, with unlimited length, having a large surface area to mass ratio, essentially exhibiting high mechanical performance and flexibility as compared to other materials. Research in the arena of nanofiber composites has shown a considerable advancement since the turn of year 20th century because of its consistent use in biomedical and biotechnological applications. Nanofiber composites fit in as a distinctive class of materials in the biomedical field since they offers a biomimetic environment on the nanometer scale wherein a three-dimensional architecture with the desired surface properties on the micrometer scale combines with mechanical strength and physiological acceptability on the macro scale. For any biological applications, nanofiber serves as an ideal biomaterial that possesses biocompatibility, biodegradability, nontoxicity, hydrophilicity and proper strength. Unambiguously, their ability to imitate the fibrillar elements of a natural extra cellular matrix in a most realistic way is central to their application. A better understanding of nanofibers’ interaction with cells, especially understanding the cell’s response to chemical and physical perturbations caused by nanofibers, and most importantly understanding their behavior in biological systems across time, will play a vital role in enhancing their potential. Thus the characterization in all aspects is of prime significance in improving the interaction properties of nanofibers with the environment. The characterization of nanofiber composites can be split inclusively on the basis of the crux material, its interactions, and applications. The nanofiber interactions in the biotic environment for biological applications will govern the properties. This book chapter reviews the surface characterization using microscopy (in vivo and in vitro), chemical characterization (using fluorescence imaging), cellular responses to the nanofiber composites (biocompatibility), and application based characterization, as some of the major highlights of the chapter.

In order to develop the mild acidic nanocatalyst, ordered mesoporous silica, SBA -15 was functionalized with chloroacetic acid (SBA/CA) via post synthetic grafting technique for useful acidic conversions such as Knoveneganel condensation, Biginelli synthesis and Mannich reaction. The nanocomposites were characterized by Powder X-ray Diffraction method, N2 adsorptiondesorption isotherm, 13 C CP-MAS NMR, FT-IR, TPD and EDXRF. Very high activity and selectivity was observed for all the conversions under milder reaction conditions. Finally, the mechanism of the reaction is proposed and discussed. Copyright © 2013 VBRI press.

In order to compare the activity and selectivity for the synthesis of β-nitro alcohols, piperazine was functionalized directly and after surface modification into the ordered mesoporous SBA-15 framework. The materials were characterized by powder X-ray diffraction, N2-adsorption–desorption isotherm, FT-IR, SS-NMR and scanning electron microscopy. The catalyst synthesized via surface modification under solvent free conditions showed very high activity and selectivity of β-nitro alcohols compared to the one synthesized by direct functionalization of SBA-15. Finally the possible reaction pathways were explained mechanistically. Surface modification of SBA-15 was achieved by radical polymerization of monomers followed by functionalization with piperazine to achieve the selective nitro alcohols in nitroaldol condensation

The comparative catalytic activity studies of biologically and industrially important compounds such as Xanthenes and bis (indolyl) methanes were evaluated over propylsulfonic acid functionalized SBA-15/SO 3 H. The material was characterized via standard characterization techniques such as Powder X-ray diffraction, FTIR, Temperature programmed desorption studies of NH 3 . The catalytic performance of SBA/SO 3 H under environmentally benign conditions results in high yield of xanthenes compared to bis (indolyl) methanes and finally the mechanism for both the reactions were proposed.

Heterogeneous liquid phase synthesis of phenytoin (5,5-diphenylhydantoin) was carried out over MgAl calcined hydrotalcites for the first time under environmental friendly conditions. The catalytic activity results showed very high conversion (80–95%) and selectivity (90–95%) of the desired product phenytoin over MgAl calcined hydrotalcites. The calcined hydrotalcites can be recycled without further loss in the activity and the possible mechanism of the reaction is also proposed.