Ultra-high sensitive cancerous cells detection and sensing capabilities of photonic biosensor.

The ultra-high sensitive cancer cell detection capabilities of one-dimensional photonic crystal with defect have been theoretically examined in this work. The simulations of the work have been carried out with MATLAB programming and transfer matrix method. The performance of the proposed biosensor loaded separately with samples containing different cancer cells has been studied by changing the period number, defect layer thickness, and incident angle corresponding to s polarized light only to identify the parameters under which the proposed design becomes ultra-sensitive. The working principle of the proposed biosensor is to sense the minute change in the refractive index of the analytes containing different cancer cells of human. This sensing is done shifting the respective defect mode inside photonic band gap of the structure from one position to other near by position due to change in the refractive index of sample under consideration. Our structure under optimum conditions yields maximum shifting in the position of defect mode from 1538 to 1648 nm corresponding to the samples containing normal and Glioblastoma cells of refractive indices 1.350 and 1.4470 respectively which results a ultra-high sensitivity of 4270.525928 nm/RIU.

Ultra-sensitive pressure sensing capabilities of defective one-dimensional photonic crystal.

Present research work deals with the extremely sensitive pressure-sensing capabilities of defective one-dimensional photonic crystal structure (GaP/SiO2)N/Al2O3/(GaP/SiO2)N. The proposed structure is realized by putting a defective layer of material Al2O3 in the middle of a structure consisting of alternating layers of GaP and SiO2. The transfer matrix method has been employed to examine the transmission characteristics of the proposed defective one-dimensional photonic crystal in addition to MATLAB software. An external application of the hydrostatic pressure on the proposed structure is responsible for the change in the position and intensity of defect mode inside the photonic band gap of the structure due to pressure-dependent refractive index properties of the materials being used in the design of the sructure. Additionally, the dependence of the transmission properties of the structure on other parameters like incident angle and defect layer thickness has also studied. The theoretical obtained numeric values of the quality factor and sensitivity are 17,870 and 72 nm/GPa respectively. These results are enough to support our claim that the present design can be used as an ultra-sensitive pressure sensor.

MATLAB simulation based study on poliovirus sensing through one-dimensional photonic crystal with defect.

The present work, theoretically examined the poliovirus sensor model composed of one-dimensional photonic crystal with defect. The transfer matrix method with the help of MATLAB software has been used to detect poliovirus present in the water sample. The main objective of the present work is to design an efficient sensor by identifying the minute variation in the refractive index of water sample due to change in the poliovirus concentration present in the sample. The alternate layers of aluminum nitride and gallium nitride has been taken to realize Bragg reflector having defect layer of air at center of the Bragg reflector. The effect of change in thickness of defect layer region, period number and incident angle corresponding to transverse electric wave has been examined to optimize the structure which correspond maximum performance of the proposed poliovirus sensing structure. The maximum performance of the structure has been obtained with optimum value of defect layer thickness 1200 nm, period number 10 and incident angle 40°. Under optimum condition maximum sensitivity of 1189.65517 nm/RIU has been obtained when the structure is loaded with waters sample of poliovirus concentration C = 0.005 g/ml whereas figure of merit, quality factor, signal to noise ratio, dynamic range, limit of detection and resolution values become 2618.28446 per RIU, 3102.06475, 2.27791, 2090.99500, 1.91E-05 and 0.24656 respectively.

Biophotonic sensor for swift detection of malignant brain tissues by using nanocomposite YBa2Cu3O7/dielectric material as a 1D defective photonic crystal.

In the present research work we have theoretically examined the biosensing capabilities of proposed one dimensional defective photonic crystal for swift detection of malignant brain tissues. The transfer matrix formulation and MATLAB computational tool have been used to examine the transmission properties of proposed structure. The identical buffer layers of nanocomposite superconducting material have been used either side of cavity region to enhance the interaction between incident light and different brain tissue samples poured into the cavity region. All the investigations have been carried out under normal incidence to suppress the experimental liabilities involved. We have investigated the biosensing performance of the proposed design by changing the values of two internal parameters (1) the cavity layer thickness (d4) and (2) volume fraction (η) of nanocomposite buffer layers one by one to get the optimum biosensing performance from the structure. It has been found that the sensitivity of the proposed design becomes 1.42607 µm/RIU when the cavity region of thickness 15dd is loaded with lymphoma brain tissue. This value of sensitivity can be further increased to 2.66136 µm/RIU with η = 0.8. The findings of this work are very beneficial for designing of various bio-sensing structures composed of nanocomposite materials of diversified biomedical applications.

Bio-Alcohol Sensor Based on One-Dimensional Photonic Crystals for Detection of Organic Materials in Wastewater.

In this work, we have explored a novel application of one-dimensional (1D) photonic crystals (PCs) as a biomarker for the detection of organic materials in wastewater. The high concentration of organic materials may lead to adverse impact on human life. In order to save human life from these adverse effects, we have investigated the bio-alcohol sensing properties of a 1D multilayer periodic structure (AB)N/C/(AB)N capable of detecting organic materials in wastewater. The proposed structure works on the principle to detect a very small change in the refractive index of the wastewater sample under investigation by means of producing a shift in the position of the defect mode inside the photonic band gap (PBG) of the proposed structure. The transfer matrix method (TMM) has been used to investigate the transmission properties of the proposed design with the help of MATLAB software. We have also studied the effect of changes in the defect layer's thickness, the volume fraction of the nanocomposite material and the incident angle on the sensitivity of our proposed bio-alcohol sensing design. Our bio-alcohol sensor shows a high sensitivity value of 500 nm/RIU and a low detection limit value of 1 × 10-5 RIU. The figure of merit and quality factor values of our bio-alcohol sensor are 5 × 103 and 5.236 × 103, respectively. The damping rate of the design is ξ=95.4927×10-5.

Externally tunable multichannel filtering applications of organic material based 1D magnetic cold-plasma photonic crystals.

In the present research work, we employed the transfer matrix method (TMM) in addition to MATLAB software to examine the transmission properties of various organic-based one-dimensional (1D) magnetic cold-plasma photonic crystals (MCPPhCs). The proposed structures were found to be made up of periodic layers of organic materials and magnetic cold-plasma (MCP) at normal incidence. An external magnetic field (B) polarized in right-hand (RH) and left-hand (LH) configurations was applied on 1D MCPPhCs. In this study, four organic materials, namely pentane, hexane, heptane, and octane, were chosen to design four 1D photonic crystals (PCs), named as PC1 (pentane-MCP), PC2 (hexane-MCP), PC3 (heptane-MCP), and PC4 (octane-MCP). Our results indicated that the central frequency of the resonant peaks of unit transmission inside the photonic band-gap (PBG) of the respective organic PCs could be tuned towards the higher or lower frequency side by applying B polarized in RH and LH configurations, respectively. We also studied the effect of the period number N to produce closely spaced N-1 transmission channels of unit transmission inside the PBG of all four organic PCs. By increasing the period number N we could increase the number of transmission channels inside the PBG as per our desire. These multiple resonant peaks of unit transmission inside PBG could be easily modulated inside the PBG to accommodate new frequencies by applying B polarized in either RH or LH configurations, respectively. Moreover, our results showed that under the RH configuration, increasing B resulted in a shifting of the resonant peak towards the higher frequency side with a reduction in its full width half maximum (FWHM), whereas the findings were the opposite in the case of increasing B under the LH configuration. These findings may be beneficial for designing externally tuneable organic chemical sensors in the microwave frequency region.

Study on a one-dimensional defective photonic crystal suitable for organic compound sensing applications.

Organic-compound-based sensors have important applications, such as applications in geothermal power stations, the shoe industry, the extraction of vegetable oil, azeotropic calibration and medical science. Herein, a 1D photonic crystal (PC) with a defect has been used to develop a photonic-technology-based organic compound sensor with optimum performance. The structure of the proposed organic compound sensor consists of a water cavity sandwiched between two symmetric sub-PCs, which are composed of alternate layers of SiO2 and ZnO. The proposed air/(SiO2/ZnO)5/cavity/(SiO2/ZnO)5/glass structure with the optimized structural parameters achieves a quality factor that varies between a minimum value of 4968.2 and a maximum value of 6418.5. The FOM and sensitivity values of the proposed sensing design are on the order of 102 and 103, respectively. The LOD value of the proposed sensor is on the order of 10-5, which is very low, as is always expected for chemical sensing designs. Thus, the simple design and excellent performance make our design highly efficient and suitable for sensing applications in the industrial and biomedical fields.

Soil quality parameters vis-a-vis growth and yield attributes of sugarcane as influenced by integration of microbial consortium with NPK fertilizers.

Intensive agriculture involving high crop intensity, unavailability of organics, and higher use of straight fertilizers causes imbalanced use and deficiencies of several other macro and micronutrients. Nutrients supply through the integration of microbial consortium containing Gluconacetobater diazotrophicus, Trichoderma harzianum, and Pseudomonas fluorescens can reduce the requirements on the one hand and can also increase the response of chemical fertilizers. Thus we had planned the present experiment with the objectives (i) to determine the effect of integrated application of microbial consortium (MC) and NPK fertilizer on soil quality parameters and crop growth and yield attributes and (ii) to assess the effect of integration on agronomic efficiency of N, P and K and find out the possibilities for reduction in applied doses of NPK, if any. Five treatments viz., T1; N0P0K0; T2: N75P13K25; T3: N150P26K50; T4: N75P13K25 + microbial consortium and T5: N150P26K50 + microbial consortium containing new strains of Trichoderma harzianum, Gluconcetobacter diazotrophicus, and Pseudomonas fluorescens (CFU 109-10 per ml liquid culture) were evaluated under four replications in a randomized block design (RBD). Experimental results indicated that integrating microbial consortium and NPK fertilizers' application proved effective in improving soil organic carbon, soil microbial population, microbial biomass carbon, microbial biomass nitrogen, and soil respiration. Integrated use of microbial consortium with NPK also improved the cation exchange capacity of soil and roots. However, the growth and yield attributes, nutrients uptake, sugarcane, and sugar yields also revealed a positive effect of microbial consortium's integrated application with NPK. The integration of MC and NPK also improved the agronomic efficiency of applied nutrients (NPK). Reduction of 50% NPK with these microbial consortia (Trichoderma harzianum, Gluconcetobacter diazotrophicus, and Pseudomonas fluorescens) was found better than the application of full NPK through chemical fertilizers. Thus application of N150P26K50 with microbial consortium can sustain soil fertility besides improving sugarcane and sugar yields in subtropical Indian conditions.

Antidyslipidemic and antioxidant activity of an unusual amino acid (2-amino-5-hydroxyhexanoic acid) isolated from the seeds of Crotalaria juncea.

In continuation of our drug discovery programme on Indian medicinal plants, we isolated an unusual amino acid, i.e. 2-amino-5-hydroxyhexanoic acid (1) from the seeds of Crotalaria juncea. The 2-amino-5-hydroxyhexanoic acid (1) showed dose dependent lipid lowering activity in the in vivo experiments and also showed good in vitro antioxidant activity. The cyclized compound, 3-amino-6-methyltetrahydro-2H-pyran-2-one (2) showed better lipid lowering and antioxidant profile than the parent compound 1.

Antidyslipidemic and antioxidant activity of the constituents isolated from the leaves of Calophyllum inophyllum.

In continuation of our drug discovery program on Indian medicinal plants, we isolated bioactive compounds (1-5) from the leaves of Calophyllum inophyllum and evaluated their antidyslipidemic activity in triton induced hyperlipidemia model. The calophyllic acid (1A) and isocalophyllic acid (1B) mixture, canophyllic acid (4) and amentoflavone (5) showed dose dependent lipid lowering activity in in vivo experiments. The compounds 1A+1B mixture and 3 also showed good in vitro antioxidant activity.

Cervical sympathetic chain schwannoma: a case report.

Tumors originating in the parapharyngeal space are rare and are fascinating to the surgeon in view of the anatomical complexity of the area, varied histological type of tumors encountered and the impressive size which some of these tumors attain before becoming clinically evident. We report a rare case of schwannoma arising from the cervical sympathetic chain presenting as a mass in the parapharyngeal space.

Effect of chromium on the level of IL-12 and IFN-gamma in occupationally exposed workers.

Chromium may affect humoral and cellular immunity, acting on T lymphocytes as well as on granulocytes and monocytes cells. Cytokines play an important role in the immune balance. In this study, the level of IL-12 and IFN-gamma were evaluated in the sera and PHA/LPS stimulated culture supernatant of human PBMCs of healthy volunteers and occupationally exposed chromium workers. All the workers were highly exposed to chromium having mean of 104.65+/-77.21 microg/dL (range 23.7-316.8 microg/dL). A suspension of exposed and unexposed human PBMC (0.5x10(6) cells/ml) prepared and cultured in RPMI-1640 supplemented with 10% FCS for 18 h in the presence or absence of LPS (10 ng/ml) which used for stimulation of IL-12 and IFN-gamma. The level of IL-12 and IFN-gamma were evaluated in the sera samples as well as LPS stimulated and unstimulated culture supernatant of h-PBMCs of chromium exposed workers. In these chromium exposed workers the level of IL-12 was 433.66+/-197.49 pg/ml and 983.45+/-330.99 pg/ml in LPS stimulated culture supernatant of normal individuals and highly chromium exposed workers, which was significant (P<0.05). Although the level of IL-12 was (78.61+/-61.03 pg/ml to 146.52+/-46.37 pg/ml) elevated in unstimulated culture supernatant of h-PBMCs of chromium exposed individuals as compared to control, but it was not significant. This observation also suggests that a significant increase in IFN-gamma production in LPS stimulated and unstimulated culture supernatant of h-PBMCs of chromium exposed workers as compared to control. However, IFN-gamma level have a significant positive correlation between blood chromium level (r=0.833, t=6.3872, P 0.05) and exposure time (in years) (r=0.8916, t=8.3540, P 0.05) of the occupationally exposed workers.

Dissection of relationship between small heat shock proteins and mycobacterial diseases.

Mycobacteria belong to a genus which has membership ranging from saprophytes to deadly pathogens that cause several infectious diseases affecting a large population of the world. Among them, tuberculosis and leprosy are the major granulomatous mycobacterial diseases. While there are successes and failures in the fight against these infections, mechanisms of pathogenesis continue to be a challenge to clinicians and biologists alike. Though it is known that both host and bacterial factors are important in the pathogenicity versus protection, all the triggers and responses are not known. Among various bacterial factors, small heat shock proteins (sSHPs) could be important targets for drug development, immunomodulation and serodiagnosis. sSHPs are the molecular chaperones that are believed to act as mantle for the mycobacteria against host's immune attack and facilitate the survival of pathogen in host body. Best studied small heat shock proteins in M. tuberculosis are sSHP16.3 and Acr2 while in M. leprae, it is 18 kD protein antigen. In this review, works on various aspects of small heat shock proteins which fall in 10 to 19 kD range have been summarized and some thoughts about future road-map have been put into.

Suppression of IL-6 level in human peripheral blood mononuclear cells stimulated with PHA/LPS after occupational exposure to chromium.

The toxic metals alter the immune response of animals as well as humans. In addition to the well documented and numerous toxic effect of chromium on various target organs, number of studies shown that acute and chronic exposure to inorganic chromium may result in impairment of immune functions in the experimental systems. Immunosuppression appears to be more subtle effect of exposure to heavy metals. Therefore, we have taken two different groups of chromium exposed individuals. These were leather tanning workers and chromeplaters. These groups of individuals were regularly exposed to chromium. All the leather tanning workers were highly exposed to chromium having a mean of 96.60+/-113.95 mg/dl (range 12.4-417.21 mg/dl). A suspension of exposed and unexposed human PBMC (0.5x10(6) cells/ml) prepared and cultured in RPMI-1640 supplemented with 10% FCS for 18 h in the presence or absence of PHA (5 microg/ml) and LPS (10 ng/ml) which used for stimulation of IL-2, IL-4, TNF-alpha, IL-10 and IL-6, respectively. The levels of Th1/Th2 cytokine: IL-2, IL-4, TNF-alpha, IL-10 and IL-6 were evaluated in the sera and PHA/LPS stimulated culture supernatant of human PBMCs of chromium exposed workers. In these workers the level of IL-6 was 543.95+/-123.75 pg/ml and 388.40+/-61.24 pg/ml in PHA/LPS stimulated culture supernatant of normal individuals and highly chromium exposed workers, which was significant (P<0.05). This observation suggests that IL-6 levels were suppressed in chromium exposed groups as compared to unexposed healthy volunteers. Although the level of IL-2 in PHA stimulated culture supernatant of PBMCs was suppressed in chromium exposed individuals but it was not significant, IL-4 and IL-10 could not be detected. However, there was no difference in TNF-alpha levels in sera samples as well as unstimulated culture supernatant of h-PBMCs of chromium exposed individuals as compared to control.

Anticoagulant therapy induced haematoma presenting as acute dysphagia.

Oropharyngeal haematoma secondary to bleeding from anticoagulant therapy is uncommon and difficult to manage. We report a case of Oropharyngeal haematoma secondary to anticoagulant Acitrom (Nicoumalone) which was treated successfully with Inj Vit K.

A case of post traumatic retropharyngeal abscess.

Retropharyngeal abscess following blunt trauma neck is rare. We report one such unusual case which was drained surgically.

A bullet in the maxillary sinus.

Maxillary Sinus is an unusual site for lodgment of foreign bodies. We present a rare case of impacted bullel in the right maxillary sinus which entered through the orbital floor which could be removed after using a nasal endoscope through a Caldwell luc approach.

Bactericidal antisense effects of peptide-PNA conjugates.

Antisense peptide nucleic acids (PNAs) can specifically inhibit Escherichia coli gene expression and growth and hold promise as anti-infective agents and as tools for microbial functional genomics. Here we demonstrate that chemical modification improves the potency of standard PNAs. We show that 9- to 12-mer PNAs, especially when attached to the cell wall/membrane-active peptide KFFKFFKFFK, provide improvements in antisense potency in E. coli amounting to two orders of magnitude while retaining target specificity. Peptide-PNA conjugates targeted to ribosomal RNA (rRNA) and to messenger RNA (mRNA) encoding the essential fatty acid biosynthesis protein Acp prevented cell growth. The anti-acpP PNA at 2 microM concentration cured HeLa cell cultures noninvasively infected with E. coli K12 without any apparent toxicity to the human cells. These results indicate that peptides can be used to carry antisense PNA agents into bacteria. Such peptide-PNA conjugates open exciting possibilities for anti-infective drug development and provide new tools for microbial genetics.

Solvent-induced beta-hairpin to helix conformational transition in a designed peptide.

An octapeptide containing a central -Aib-Gly- segment capable of adopting beta-turn conformations compatible with both hairpin (beta(II') or beta(I')) and helical (beta(I)) structures has been designed. The effect of solvent on the conformation of the peptide Boc-Leu-Val-Val-Aib-Gly-Leu-Val-Val-OMe (VIII; Boc: t-butyloxycarbonyl; OMe: methyl ester) has been investigated by NMR and CD spectroscopy. Peptide VIII adopts a well-defined beta-hairpin conformation in solvents capable of hydrogen bonding like (CD(3))(2)SO and CD(3)OH. In solvents that have a lower tendency to interact with backbone peptide groups, like CDCl(3) and CD(3)CN, helical conformations predominate. Nuclear Overhauser effects between the backbone protons and solvent shielding of NH groups involved in cross-strand hydrogen bonding, backbone chemical shifts, and vicinal coupling constants provide further support for the conformational assignments in different solvents. Truncated peptides Boc-Val-Val-Aib-Gly-Leu-Val-Val-OMe (VII), Boc-Val-Val-Aib-Gly-Leu-Val-OMe (VI), and Boc-Val-Aib-Gly-Leu-OMe (IV) were studied in CDCl(3) and (CD(3))(2)SO by 500 MHz (1)H-NMR spectroscopy. Peptides IV and VI show no evidence for hairpin conformation in both the solvents. The three truncated peptides show a well-defined helical conformation in CDCl(3). In (CD(3))(2)SO, peptide VII adopts a beta-hairpin conformation. The results establish that peptides may be designed, which are poised to undergo a dramatic conformational transition.

Structural and thermodynamic consequences of introducing alpha-aminoisobutyric acid in the S peptide of ribonuclease S.

The S protein-S peptide interaction is a model system to study binding thermodynamics in proteins. We substituted alanine at position 4 in S peptide by alpha-aminoisobutyric acid (Aib) to investigate the effect of this substitution on the conformation of free S peptide and on its binding to S protein. The thermodynamic consequences of this replacement were studied using isothermal titration calorimetry. The structures of the free and complexed peptides were studied using circular dichroic spectroscopy and X-ray crystallography, respectively. The alanine4Aib replacement stabilizes the free S peptide helix and does not perturb the tertiary structure of RNase S. Surprisingly, and in contrast to the wild-type S peptide, the DeltaG degrees of binding of peptide to S pro, over the temperature range 5-30 degrees C, is virtually independent of temperature. At 25 degrees C, the DeltaDeltaG degrees, DeltaDeltaH degrees, DeltaDeltaS and DeltaDeltaCp of binding are 0.7 kcal/mol, 2.8 kcal/mol, 6 kcal/mol x K and -60 kcal/mol x K, respectively. The positive value of DeltaDeltaS is probably due to a decrease in the entropy of uncomplexed alanine4Aib relative to the wild-type peptide. The positive value of DeltaDeltaH: degrees is unexpected and is probably due to favorable interactions formed in uncomplexed alanine4Aib. This study addresses the thermodynamic and structural consequences of a replacement of alanine by Aib both in the unfolded and complexed states in proteins.