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It is common to study the strong decay of a heavy nucleus as a tunneling phenomenon where the $��$ ($^4$He) or a light nuclear cluster tunnels through the Coulomb barrier formed by its interaction with the heavier daughter nucleus. The position and width of the Coulomb barrier are determined by the total interaction potential between the two daughter nuclei. We examine the effects of including nonlocality and deformation in the interaction potential by calculating the half-lives, $t_{1/2}$, and thereby phenomenological preformation factors of several nuclei which have the possibility of decaying by emitting either an $��$ or a light nuclear cluster. The effect of deformation manifests itself by a decrease in $t_{1/2}$ for all the decays studied. The effect of nonlocality is studied within two different models of the nuclear potential: the energy-independent but angular momentum ($l$) dependent Mumbai (M) potential and the energy-dependent Perey-Buck (PB) potential. The nonlocal nuclear interaction leads to a decrease in all half-lives studied. Though the decrease is larger due to the Perey-Buck potential, half-lives evaluated using the Mumbai potential show a strong sensitivity to the $l$ value in the decay. This feature of the $��$ and cluster decay half-lives can provide a complementary tool in addition to scattering data which are more commonly used to fix the parameters of a nonlocal potential in literature., 19 pages, 5 figures

The following thesis describes research built upon three major aims, such as investigating the evanescent field based optical detection, surface modification, characterisation and non-invasive means of detection of multi-lumen capillaries (MLC). Where the common overall direction has been to develop practical and novel (bio) analytical applications of surface modified MLC. Within the first Chapter of this thesis, the general background principles and ideas, and the supporting literature behind much of what is discussed in subsequent Chapters is presented. The use of multi-lumen capillaries (MLCs) has expanded over recent years, with numerous applications being reported across many areas of analytical chemistry. Multi-lumen capillaries possess multiple parallel micro-channels, which provide a higher surface-area-to-volume ratio when compared to their single lumen (traditional fused silica capillary) counterparts. MLCs are most well-known for their application as fused silica capillary-based optical fibres otherwise known as photonic crystal fibres (PCFs). PCFs have multiple parallel multi-µm channels within the capillary, often surrounding a solid silica core. MLCs originated within the fields of fibre lasers, fibre sensors, and optical fibre-based communications. These fibres can thus be readily used as waveguides, and have significant potential for novel applications in the fields of sensing and analytical detection. Their unique structure provides an excellent platform within which light and chemical samples can actively interact for quantitative spectroscopic analysis. Additionally, with the enhanced surface area of these capillaries, their potential for applications in areas of in-capillary extraction, reaction and chromatographic separation is also significant. In the second Chapter we present a complete literature review of the application of MLCs reported to-date, specifically in the area of the separation science. Multi-lumen capillaries of many dimensions have been fabricated and modified, for use within a wide range of applications within separation science. As mentioned above, this extends from sample preparation and sample extraction, to chromatographic separations, and detection sciences. The most commercially available range of MLCs, the so-called photonic crystal fibres (PCFs), emerged in the 1990's, and were specifically designed for optical applications, predominantly as waveguides. Since then, a range of modifications have been reported, with the fibres applied to a wide variety of analytical applications, in liquid and gas phase analysis or detection. This comprehensive review provides an up-to-date and state-of-the-art analysis of such applications of PCFs and related MLCs, detailing the chemical modifications that have been carried out, and the subsequent applications of the developed materials. This Chapter has been published in its entirety as a co-authored review within Trends in Analytical Chemistry. In the third Chapter, a novel investigation of evanescent field-based optical detection using multi-lumen capillaries (MLCs) is presented. The micro-structured capillaries provide the potential for long effective optical pathways with the additional advantage of high surface area-to-volume ratios. Their use in in-capillary evanescent field-based detection could offer several significant advantages, including on-line sensing, in-capillary reaction monitoring and integration with various chromatographic applications. The Chapter involves comparison of the effective detection pathlength of empty MLCs with MLCs that have gold nanoparticles (AuNPs) immobilised on the surface of the channel. MLCs with 126 parallel channels of either 4 µm or 8 µm inner diameter were used, connecting a light source and optical detector. Experimental measurements were carried out with different concentrations of a brilliant blue dye solution using a flow-injection analysis (FIA) approach. Calibration curves using the brilliant blue dye solution were constructed to demonstrate the potential of the approach, and were linear up to 5.12 mM, with typical R\(^2\) values of 0.998. The effective pathlengths of the empty MLCs range between 1.205 mm and 0.075 mm, and with AuNPs on the surface the effective pathlengths increased relatively to 1.893 mm and 0.229 mm for the 4-µm and 8-µm MLCs, respectively. In addition, a peak dispersion study was carried out using a scanning capacitively coupled contactless conductivity detector (sC\(^4\)D) and injections of a 10 mM NaCl solution. The 8-µm channel MLC showed lowest dispersion with the difference in width of the peak being 0.004 mm (23.53%) from the beginning to the end of the 12-cm capillary. In the fourth Chapter, the modification of the internal channel wall of a multi-lumen capillary (MLC) with a polymer layer was investigated. Lauryl methacrylate ethylene dimethacrylate (LMA-co-EDMA)-based monolithic porous layer open tubular (monoPLOT) MLC columns were prepared, using a UV polymerisation approach. The study aimed to rapidly produce a uniform monolith layer within each channel of the MLC using UV light (a 254 nm lamp or a 255 nm LED). The difference in monolithic growth within the MLCs, with and without the acrylate external capillary coating, was noticeable due to the initiating UV light either travelling through the core of the MLC as an evanescent wave or, in the case of the uncoated MLC, directly through the wall. The uniform wall coverage of the monolith was monitored using a scanning capacitively coupled contactless conductivity detector (sC\(^4\)D) and scanning electron microscopy (SEM), with the greatest monolith growth (up to 1000 nm) occurring in the uncoated MLC where the light was able to enter through the wall. Photo-initiation using the UV LED gave the least homogeneous coverage; some channels of the MLC were blocked and some did not show any polymerisation. The application of monolithic MLCs for the retention of series of test proteins was also briefly explored. Under optimised gradient conditions, effective retention of proteins was demonstrated on the MLC column with the greatest amount of immobilised monolith (the uncoated MLC). In the fifth Chapter of this thesis, the simultaneous homogenous modification of all channels within a multi-lumen capillary (MLC) was investigated. Capillaries were first functionalised with 3-aminopropyltriethoxysilane (APTES), followed by the attachment of gold nanoparticles (AuNPs). A gold layer thickness of ~15 nm was observed, which corresponds well with the 15 nm AuNP particle size and confirmed a mono-layer structure. These attached AuNPs were then used as seeds for a surface reduction reaction, in which a mixture of a reducing agent (hydroxylamine) and chloroauric acid (HAuCl\(^4\)) was slowly passed through the MLC. During the process, the deposited gold particles agglomerated within the capillary when they reached a certain size (100 nm) eventually forming a complete uniform gold layer within each channel. Scanning capacitively coupled contactless conductivity detection (sC\(^4\)D) measurements were applied to determine uniformity of coverage along the length of the capillaries. Under optimal conditions, an AuNP-modified 126 x 4 μm inner diameter (ID) MLC gave an average C\(^4\)D response RSD of 0.8% along the 15 cm length, indicating a uniform axial gold coverage. FE-SEM images of the capillary cross-sections also indicated uniform radial gold coverage in all 126 channels of each MLC. The obtained gold layer was then functionalised with Erythrina cristagalli lectin (ECL) via a bio-linker to demonstrate one potential in-capillary extraction application of the modified MLC. The ECL-modified MLC was applied to the selective extraction and isolation of galactosylated proteins. In the final Chapter, a novel microreactor prepared using surface modified PCF capillaries was developed. The capillary investigated contained 126 parallel channels, each of 4 μm internal diameter. The modified PCF, along with conventional fused silica capillaries of 25 μm and 50 μm internal diameter, were treated by (3-aminopropyl)triethoxysilane (APTES) and then modified with gold nanoparticles, of ∼20 nm in diameter, to ultimately provide immobilisation sites for the proteolytic enzyme, trypsin. The modified capillaries and PCFs were characterised and again profiled using non-invasive sC\(^4\)D. The sC\(^4\)D profiles confirmed a significantly higher amount of enzyme was immobilised within the PCF when compared to the fused silica capillaries, attributable to the increased surface to volume ratio. The modified PCF was used for dynamic protein digestion, where peptide fragments were collected and subjected to off-line chromatographic evaluation. The digestion was achieved with the PCF reactor, using a residence time of just 1.26 min, following which the HPLC peak associated with the intact protein decreased by >70%. The PCF reactors behaved similarly to the classical in vitro or in-solution approach but provided a reduction in digestion time, and fewer peaks associated with trypsin auto-digestion, which is common using in-solution digestion. This Chapter has been published in its entirety as a co-authored paper within the Analyst. The thesis is comprised of seven Chapters, first Chapter gives overview of the thesis, second Chapter is literature review of MLC in analytical chemistry. Chapter three to six involved major line of experimental work, with key aims described in the thesis: (i) optical detection using evanescent field-based system, (ii) synthesis of organic polymer layer and AuNPs to provide solid stationary phase for further attachments of legends (lectin and trypsin) in MLC and, (iii) the characterization of MLC using non-invasive techniques

$p\,��$ emission in coincidence following $K^-$ absorption at rest in nuclei is studied using quantum mechanical scattering theory and nuclear wave functions. $K^-$ absorption is assumed to occur on two protons in the nucleus. In the formalism, emphasis is put on the study of the final state interaction (FSI) effects of $p$ and $��$ with the recoiling nucleus. We include elastic scattering and single nucleon knock-out (KO) channels in the FSI. Calculations are presented for the $^{12}$C nucleus, using shell model wave functions, and without any extra mass modification of the $K^-\,pp$ system in the nucleus. Calculated results are presented for the angular correlation distribution between $p$ and $��$, their invariant mass distribution and the momentum spectra of $p$ and $��$. These results are compared with the corresponding experimental measurements \cite{agnello}. With only elastic scattering FSI included, the angular correlation distribution and the momentum spectra are found to be in good accord with the corresponding measurements. With full FSI the calculated $p\,��$ invariant mass distribution is found to have two peaks, one corresponding to the elastic scattering FSI and another to single nucleon KO FSI. The KO peak agrees fully, in position and shape, with the peak observed in Ref. \cite{agnello}. The peak corresponding to elastic scattering FSI does not seem to exist in the measured distribution. Considering that such a two peak structure is always seen in the inclusive ($p$, $p^\prime $) and ($e$, $e^\prime $) reactions in nuclei at intermediate energies, absence of the elastic scattering peak in the $p\,��$ reaction is intriguing., 33 pages, 9 figures To appear in Phys. Rev. C

A model for the p d --> p d eta reaction published earlier, including the final state interaction (FSI) of all particles, is revisited to investigate the low energy data on this reaction. The three body problem of p-d-eta scattering in the final state is approximated in terms of pairwise interactions between the three particles in the final state. Apart from a comparison with some preliminary data, two new findings relevant to the near threshold data analysis are reported. The first one points toward the limitations of an FSI factor used conventionally to extract the eta-deuteron scattering length and infer subsequently on the existence of eta-mesic states. The second result emphasizes the role of the $p-d$ FSI and the strong Coulomb repulsion near threshold. Finally, a comparison of the above model calculation with low energy data, excludes very large eta-nucleon scattering lengths., 11 pages, 4 figures Accepted for publication in Mod. Phys. Lett. A

We present a calculation for $��$ production in the $p-^6Li$ fusion near threshold including the $��-^7Be$ final state interaction (FSI). We consider the $^6Li$ and $^7Be$ nuclei as $��-d$ and $��-^3He$ clusters respectively. The calculations are done for the lowest states of $^7Be$ with $J = ({3\over2}^-, {1\over2}^-)$ resulting from the $L = $1 radial wave function. The $��-^7Be$ interaction is incorporated through the $��-^7Be$ $T-$matrix, constructed from the medium modified matrices for the $��-^3He$ and $��-��$ systems. These medium modified matrices are obtained by solving few body equations, where the scattering in nuclear medium is taken into account., To appear in the proceedings of IVth DAE-BRNS Workshop on HADRON PHYSICS, Aligarh Muslim University, Aligarh, 18-23 Feb. 2008

A study of the $p d \to p d ��$ reaction in the energy range where the recent data from Uppsala are available, is done in the two-step model of $��$ production including the final state interaction. The $��-d$ final state interaction is incorporated through the solution of the Lippmann Schwinger equation using an elastic scattering matrix element, $T_{��d \to ��d}$, which is required to be half off-shell. It is written in a factorized form, with an off-shell form factor multiplying an on-shell part given by an effective range expansion up to the fourth power in momentum. The parameters of this expansion have been taken from an existing recent relativistic Faddeev equation solution for the $��NN$ system corresponding to different $��-N$ scattering amplitudes. Calculations have also been done using few body equations within a finite rank approximation (FRA) to generate $T_{��d \to ��d}$. The $p-d$ final state interaction is included in the spirit of the Watson-Migdal prescription by multiplying the matrix element by the inverse of the Jost function. The $��-d$ interaction is found to be dominant in the region of small invariant $��-d$ mass, $M_{��d}$. The $p-d$ interaction enhances the cross section in the whole region of $M_{��d}$, but is larger for large $M_{��d}$. We find nearly isotropic angular distributions of the proton and the deuteron in the final state. All the above observations are in agreement with data. The production mechanism for the entire range of the existing data on the $p d \to p d ��$ reaction seems to be dominated by the two-step model of $��$ production., 22 pages, 12 figures, accepted for publication in Phys. Rev. C

9 pages, 10 figures.-- PACS nrs.: 25.10.+s; 25.40.Ve; 24.10.Eq.-- ISI Article Identifier: 000246891100009.-- ArXiv pre-print available at: http://arxiv.org/abs/0704.1530, A study of the pd -> pdη reaction in the energy range where the recent data from Uppsala are available is done in the two-step model of eta production including the final state interaction. The η-d final state interaction is incorporated through the solution of the Lippmann Schwinger equation using an elastic scattering matrix element, T-ηd->ηd, which is required to be half off-shell. It is written in a factorized form, with an off-shell form factor multiplying an on-shell part given by an effective range expansion up to the fourth power in momentum. The parameters of this expansion have been taken from an existing recent relativistic Faddeev equation solution for the ηNN system corresponding to different η-N scattering amplitudes. Calculations have also been done using few body equations within a finite rank approximation to generate T-ηd->ηd. The p-d final state interaction is included in the spirit of the Watson-Migdal prescription by multiplying the matrix element by the inverse of the Jost function. The η-d interaction is found to be dominant in the region of small invariant η-d mass, M-ηd. The p-d interaction enhances the cross section in the whole region of M-ηd, but is larger for large M-ηd. We find nearly isotropic angular distributions of the proton and the deuteron in the final state. All the above observations are in agreement with the data. The production mechanism for the entire range of the existing data on the pd -> pdη reaction seems to be dominated by the two-step model of η production., This work was done under a research grant by the Department of Science and Technology, Government of India. The authors (N.J.U., K.P.K., and B.K.J.) gratefully acknowledge the same.

Thiazolidinedione (TZD) containing derivatives have been proved to be promising anticancer agents in preclinical and clinical evaluation phases. Hybrid molecules not just offer the benefits such as enhanced therapeutic effects and improved specificity, but in addition could beat drug resistance, so hybridization of thiazolidinedione scaffold with other anticancer pharmacophoric scaffolds may constitute a hopeful strategy to develop newer and more efficacious anticancer agents. Based on this approach, in past decade, several such hybrids containing TZD scaffold have been reported and evaluated for their antitumor activity, and some of them revealed excellent in vitro potency, indicating their potential as presumed anticancer drugs. This review summarizes the recent advances of TZD hybrids as potential anticancer agents, highlighting their antitumor activity and possible mechanism of action. Structure‐activity relationship (SAR) studies will also be discussed to direct the rational molecular hybridization of TZD scaffolds to design more effective candidates.

In search for new and safer anti-cancer agents, a structurally guided pharmacophore hybridization strategy of two privileged scaffolds, namely diaryl pyrazolines and imidazolidine-2,4-dione (hydantoin), was adopted resulting in a newfangled series of compounds (H1-H22). Herein, a bio-isosteric replacement of “pyrrolidine-2,5-dione” moiety of our recently reported antitumor hybrid incorporating diaryl pyrazoline and pyrrolidine-2,5-dione scaffolds with “imidazoline-2,4-dione” moiety has been incorporated. Complete biological studies revealed the most potent analog among all i.e. compound H13, which was at-least 10-fold more potent compared to the corresponding pyrrolidine-2,5-dione, in colon and breast cancer cells. In-vitro studies showed activation of caspases, arrest of G0/G1 phase of cell cycle, decrease in the expression of anti-apoptotic protein (Bcl-2) and increased DNA damage. In-vivo assay on HT-29 (human colorectal adenocarcinoma) animal xenograft model unveiled the significant anti-tumor efficacy along with oral bioavailability with maximum TGI 36% (i.p.) and 44% (per os) at 50 mg/kg dose. These findings confirm the suitability of hybridized pyrazoline and imidazolidine-2,4-dione analog H13 for its anti-cancer potential and starting-point for the development of more efficacious analogs.