An easy to construct sub-micron resolution imaging system.

We report an easy to construct imaging system that can resolve particles separated by [Formula: see text] 0.68 [Formula: see text]m with minimum aberrations. Its first photon collecting lens is placed at a distance of 31.6 mm giving wide optical access. The microscope has a Numerical Aperture (NA) of 0.33, which is able to collect signal over 0.36 sr. The diffraction limited objective and magnifier recollects 77% photons into the central disc of the image with a transverse spherical aberration of 0.05 mm and magnification upto 238. The system has a depth of field of 142 [Formula: see text]m and a field of view of 56 [Formula: see text]m which images a large ensemble of atoms. The imaging system gives a diffraction limited performance over visible to near-infrared wavelengths on optimization of the working distance and the distance between the objective and magnifier.

Atomic flux distribution from a low-divergent dark wall oven.

Nearly collimated atomic beam is of interest for a variety of experiments. This article reports a simple way of modifying the atomic beam distribution using a dark wall oven and describes detailed study of outcoming atoms' spatial distribution. A simple design is obtained by employing the fact that inhomogeneous thermal distribution along a capillary results due to its partial resistive heating. Based on this phenomenon, we have designed a dark wall oven consisting of a reservoir, collimator, and cold absorber at the exit end of atoms, where all three are fabricated out of a single stainless steel capillary. The nearly collimated spatial distribution of the atoms resulting due to the absorber eliminating the atoms diverging above a certain angle is modeled and experimentally verified. A divergence as minimum as 1.2(1)° corresponding to a half angle θ1/2 = 0.9(1)° is measured at an oven temperature of 250 °C that produces an atomic flux of about 8 × 109 atoms s-1. Total flux as estimated using our measured spatial distribution of atoms matches well with the numerically simulated values of it for the dark wall oven.

MEASUREMENT OF OPERATIONAL QUANTITIES Hp(0.07) AND Hp(3) FOR INDIGENOUSLY DEVELOPED 106Ru/106Rh SOURCE USING AN EXTRAPOLATION CHAMBER.

In the present study, a prototype 106Ru/106Rh source was fabricated using high level liquid waste from reactor fuel, fixed in a stainless steel housing with a window and backing made of silver. The study involves measurement of the operational quantities Hp(0.07), Hp(3) and the percentage depth dose (PDD) using an extrapolation chamber. It also involves determination of necessary correction factors to arrive at Hp(0.07) and Hp(3) following International Organisation for Standardisation (ISO) and methods suggested in literature. The study facilitates incorporation of the 106Ru/106Rh source as a beta reference source for quality assurance programme in TLD personnel monitoring as per the guidelines of ISO.

Estimation of the ion-trap assisted electrical loads and resulting BBR shift.

Capacitive, inductive and resistive loads of an ion-trap system, which can be modelled as LCR circuits, are important to know for building a high accuracy experiment. Accurate estimation of these loads is necessary for delivering the desired radio frequency (RF) signal to an ion trap via an RF resonator. Of particular relevance to the trapped ion optical atomic clock, determination of these loads lead to accurate evaluation of the Black-Body Radiation (BBR) shift resulting from the inaccurate machining of the ion-trap itself. We have identified different sources of these loads and estimated their values using analytical and finite element analysis methods, which are found to be well in agreement with the experimentally measured values. For our trap geometry, we obtained values of the effective inductive, capacitive and resistive loads as: 3.1 µH, 3.71 (1) µH, 3.68 (6) µH; 50.4 pF, 51.4 (7) pF, 40.7 (2) pF; and 1.373 Ω, 1.273 (3) Ω, 1.183 (9) Ω by using analytical, numerical and experimental methods, respectively. The BBR shift induced by the excess capacitive load arising due to machining inaccuracy in the RF carrying parts has been accurately estimated, which results to a fractional frequency shift of 6.6 × 10-17 for an RF of 1 kV at 2π × 15 MHz and with ±10 µm machining inaccuracy. This needs to be incorporated into the total systematic uncertainty budget of a frequency standard as it is about one order of magnitude higher than the present precision of the trapped ion optical clocks.

Unique reversibility in extraction mechanism of U compared to solvent extraction for sorption of U(VI) and Pu(IV) by a novel solvent impregnated resin containing trialkyl phosphine oxide functionalized ionic liquid.

Novel Solvent Impregnated Resin (SIR) material was prepared by impregnating a trialkyl phosphine oxide functionalized ionic liquid (IL) into an inert polymeric material XAD-7. A series of SIR materials were prepared by varying the IL quantity. Sorption of both U(VI) and Pu(IV) were found to increase with increasing IL concentration in SIR up to an optimum IL concentration of 435 mg g-1 of SIR beyond which no effect of IL concentration was observed. A change of mechanism of sorption for U(VI) by SIR was observed in comparison to solvent extraction. The dependency of U(VI) sorption with nitric acid concentration showed a reverse trend compared to solvent extraction studies while for Pu(IV) the trend remained same as observed with solvent extraction. Sorption of both the radionuclides was found to follow pseudo second order mechanism and Langmuir adsorption isotherm. Distribution co-efficient measurements on IL impregnated SIR showed highly selective sorption of U(VI) and Pu(IV) over other trivalent f-elements and fission products from nitric acid medium.

Carbon nano tubes functionalized with novel functional group- amido-amine for sorption of actinides.

The manuscript presents the results on the sorption of U(VI), Am(III) & Eu(III) from pH medium by a novel amido-amine functionalized multiwalled carbon nanotube (MWCNT). The novel functional group was introduced in the MWCNT by two step processes and characterized by various instrumental techniques like Scanning Electron Microscopy (SEM), Raman and X-ray Photoelectron Spectroscopy (XPS). The sorption process was found to be highly dependent on the pH of the solution with maximum sorption for both 233U, 241Am & 152+154Eu at pH 7.0. Kinetics of sorption was found to be fast with equilibrium reached in ∼15min and the sorption was found to be following pseudo 2nd order kinetics for the radionuclides. The sorption for both 233U and 152+154Eu followed Langmuir sorption model with maximum sorption capacity of 20.66mg/g and 16.1mg/g respectively. This has been explained by DFT calculations which shows that more negative solvation energy of U(VI) compared to Am(III) and Eu(III) and stronger U-MWCNT-AA complex is responsible for higher sorption capacity of U(VI) compared to Am(III) and Eu(III).The synthesized amido-amine functionalized MWCNT is a very promising candidate for removal of actinides and lanthanides from waste water solution with high efficiency.

Structures of riboswitch RNA reaction states by mix-and-inject XFEL serial crystallography.

Riboswitches are structural RNA elements that are generally located in the 5' untranslated region of messenger RNA. During regulation of gene expression, ligand binding to the aptamer domain of a riboswitch triggers a signal to the downstream expression platform. A complete understanding of the structural basis of this mechanism requires the ability to study structural changes over time. Here we use femtosecond X-ray free electron laser (XFEL) pulses to obtain structural measurements from crystals so small that diffusion of a ligand can be timed to initiate a reaction before diffraction. We demonstrate this approach by determining four structures of the adenine riboswitch aptamer domain during the course of a reaction, involving two unbound apo structures, one ligand-bound intermediate, and the final ligand-bound conformation. These structures support a reaction mechanism model with at least four states and illustrate the structural basis of signal transmission. The three-way junction and the P1 switch helix of the two apo conformers are notably different from those in the ligand-bound conformation. Our time-resolved crystallographic measurements with a 10-second delay captured the structure of an intermediate with changes in the binding pocket that accommodate the ligand. With at least a 10-minute delay, the RNA molecules were fully converted to the ligand-bound state, in which the substantial conformational changes resulted in conversion of the space group. Such notable changes in crystallo highlight the important opportunities that micro- and nanocrystals may offer in these and similar time-resolved diffraction studies. Together, these results demonstrate the potential of 'mix-and-inject' time-resolved serial crystallography to study biochemically important interactions between biomacromolecules and ligands, including those that involve large conformational changes.

Sundew plant, a potential source of anti-inflammatory agents, selectively induces G2/M arrest and apoptosis in MCF-7 cells through upregulation of p53 and Bax/Bcl-2 ratio.

The worldwide cancer incidences are remarkable despite the advancement in cancer drug discovery field, highlighting the need for new therapies focusing on cancer cell and its microenvironment, including inflammation. Several species of Drosera (family: Droseraceae) are used in various traditional as well as homeopathic systems of medicine. Drosera burmannii Vahl. is also enlisted in French Pharmacopoeia in 1965 for the treatment of inflammatory diseases, including chronic bronchitis, asthma and whooping cough. The present study is designed to substantiate the potential of D. burmannii in in vitro anticancer activity and its relation with anti-inflammatory property. In vitro anticancer study revealed that DBME is inhibiting the proliferation of MCF-7 cells without affecting the viability of other malignant and non-malignant cells. DBME induced G2/M phase arrest and apoptosis in MCF-7 cells by suppressing the expression of cyclin A1, cyclin B1 and Cdk-1 and increasing the expression of p53, Bax/Bcl-2 ratio leading to activation of caspases and PARP degradation. Presence of caspase-8 (Z-IETD-fmk) and caspase-9 (Z-LEHD-fmk) inhibitors alone did prevent the apoptosis partially while apoptosis prevention was significantly observed when used in combination, suggesting vital role of caspases in DBME-induced apoptosis in MCF-7 cells. DBME also downregulated LPS-induced increased expression of iNOS, COX-2 and TNF-α along with suppression on intracellular ROS production that confirms the potential of DBME as anti-inflammatory extract. GCMS analysis revealed the presence of four major compounds hexadecanoic acid, tetradecanoic acid, hexadecen-1-ol, trans-9 and 1-tetradecanol along with some other fatty acid derivatives and carotenoids (Beta-doradecin) in DBME. These findings confirmed the anti-inflammatory activity of DBME, which is already listed in French Pharmacopeia in 1965. Here we have additionally reported the anti-breast cancer activity of DBME and its relation to the anti-inflammatory potential. Hence, an ethnopharmacological approach can be considered as useful tool for the discovery of new drug leads.

BenzoDODA grafted polymeric resin-Plutonium selective solid sorbent.

A new ligand grafted polymeric resin (BenzoDODA SDVB) was synthesized by covalently attaching plutonium selective ligand (BenzoDODA) on to styrene divinyl benzene (SDVB) polymer matrix. BenzoDODA SDVB resin was evaluated for separation and recovery of plutonium(IV) from nitric acid medium. Sorption of Pu(IV) was found to decrease with the increase in nitric acid concentration, with very small sorption above 7.0M HNO3. Sorption kinetics was fast enough to achieve the equilibrium within 60min of contact where the kinetic data fitted well to pseudo-second-order model. Sorption isotherm data fitted well to Langmuir model suggesting chemical interaction between the BenzoDODA moiety and plutonium(IV) ions. Sorption studies with some of representative radionuclides of high level waste showed that BenzoDODA SDVB is selective and therefore could be a promising solid sorbent for separation and recovery of plutonium. Further, the theoretical calculations done on BenzoDODA SDVB resin suggested Pu(NO3)4·BenzoDODA (1:1) sorbed complex conformed to generally observed square antiprism geometry of the plutonium complexes, with contributions from oxygen atoms of four nitrate ions as well as from four oxygen atoms present in BenzoDODA (two phenolic ether oxygen atoms and two carbonyl oxygen atoms of amidic moiety).

Tailor-Made Temperature-Sensitive Micelle for Targeted and On-Demand Release of Anticancer Drugs.

The design of nanomedicines from the tuned architecture polymer is a leading object of immense research in recent years. Here, smart thermoresponsive micelles were prepared from novel architecture four-arm star block copolymers, namely, pentaerythritol polycaprolactone-b-poly(N-isopropylacrylamide) and pentaerythritol polycaprolactone-b-poly(N-vinylcaprolactam). The polymers were synthesized and tagged with folic acid (FA) to render them as efficient cancer cell targeting cargos. FA-conjugated block copolymers were self-assembled to a nearly spherical (ranging from 15 to 170 nm) polymeric micelle (FA-PM) with a sufficiently lower range of critical micelle concentration (0.59 × 10(-2) to 1.52 × 10(-2) mg/mL) suitable for performing as an efficient drug carrier. The blocks show lower critical solution temperature (LCST) ranging from 30 to 39 °C with high DOX-loading content (24.3%, w/w) as compared to that reported for a linear polymer in the contemporary literature. The temperature-induced reduction in size (57%) of the FA-PM enables a high rate of DOX release (78.57% after 24 h) at a temperature above LCST. The DOX release rate has also been tuned by on-demand administration of temperature. The in vitro biocompatibilities of the blank and DOX-loaded FA-PMs have been studied by the MTT assay. The cellular uptake study proves selective internalization of the FA-PM into cancerous cells (C6 glioma) compared that into normal cells (HaCaT). In vivo administration of the DOX-loaded FA-PMs into the C6 glioma rat tumor model resulted in significant accumulation in tumor sites, which drastically inhibited the tumor volume by ∼83.9% with respect to control without any significant systemic toxicity.

Efficient transport of Am(III) from nitric acid medium using a new conformationally constrained (N,N,N',N'-tetra-2-ethylhexyl)7-oxabicyclo[2.2.1]heptane-2,3-dicarboxamide across a supported liquid membrane.

Am(III) is one of the most hazardous radionuclide present in nuclear fuel cycle. A new conformationally constrained diamide, (N,N,N',N'-tetra-2-ethylhexyl)7-oxabicyclo[2.2.1]heptane-2,3-dicarboxamide (OBDA) was studied for Am(III) transport from HNO3 medium across a Supported Liquid Membrane. Transport rate was observed to be significantly fast with ∼95% transport of Am(III) within 1h using 0.1M OBDA in the presence of 15% isodecyl alcohol (IDA)/n-dodecane as carrier. The mechanism of transport was investigated by studying various parameters like feed HNO3/NaNO3 concentration, OBDA concentration in the membrane, membrane pore size, membrane thickness etc. From these studies, the mechanism of transport was found to be diffusion controlled with diffusion co-efficient value of 5.1×10(-6)cm(2)/s. The membrane was found to be highly selective for tri- and tetra-valent actinides, and trivalent lanthanides. OBDA based membrane was found to be stable for at least for ten consecutive cycles of operation.

Note: Measuring capacitance and inductance of a helical resonator and improving its quality factor by mutual inductance alteration.

Narrow bandwidth and high voltage radio frequency (RF) is an essential requirement for stable confinement of ions within a RF trap and helical resonators are commonly used for that purpose. Effective capacitance and inductance of a helical resonator are estimated by measuring resonant frequencies for different external loads. Load capacitance of an ion trap can be estimated from this method and a resonator can be constructed for desired resonant frequency. We demonstrate a very simple method to achieve higher Q-factor of a resonator by optimizing mutual separation between the primary antenna and helical coil. We also formulate a set of analytical equations for calculating overall inductance, resistance, and Q-factor of a loaded helical resonator.

Phytochemical profile of a microalgae Euglena tuba and its hepatoprotective effect against iron-induced liver damage in Swiss albino mice.

AIMS: This study was aimed to evaluate different phytochemical constituents and the ameliorating effect of 70% methanol extract of Euglena tuba (ETME) on iron overload-induced liver injury, along with its in vitro iron-chelating and DNA protection effects. METHODS AND RESULTS: Phytochemicals of ETME were identified by GC-MS analysis. Iron chelation and protection of Fenton reaction-induced DNA damage was conducted in vitro. Post oral administration of ETME to iron-overloaded mice, the levels of serum parameters, antioxidant enzymes, liver iron, lipid peroxidation, protein carbonyl and hydroxyproline contents were measured. ETME showed inhibition of lipid peroxidation, protein oxidation and liver fibrosis. The serum markers and liver iron were lessened, whereas enhanced levels of liver antioxidant enzymes were detected in ETME-treated group. Furthermore, the histopathological observations also substantiated the protective effects of the extract. CONCLUSIONS: Several bioactive compounds identified by GC-MS may be the basis of hepatoprotective as well as antioxidant and iron-chelating effect of ETME. SIGNIFICANCE AND IMPACT OF THE STUDY: Currently available iron-chelating agents show several side effects and limitations which may be overcome by ETME, which suggest its benefit against pathology of iron overload-linked diseases. Hence, ETME can be used as a promising hepatoprotective agent.

Supported liquid membrane transport studies on Am(III), Pu(IV), U(VI) and Sr(II) using irradiated TODGA.

Transport behaviour of actinides viz. Am(3+), Pu(4+) and UO(2)(2+) was investigated from nitric acid feed conditions using PTFE (polytetrafluoroethylene) flat sheet supported liquid membranes (SLM) containing an irradiated solvent system comprising of N,N,N',N'-tetra-n-octyldiglycolamide (TODGA) as the carrier extractant and N,N-di-n-hexyloctanamide (DHOA) as the phase modifier. The present studies were carried out in order to understand the effect of irradiation on the long term reusability of the SLM and the decontamination behaviour in the absorbed dose range of 0-100 MRad. The studies using irradiated carrier included those with irradiated TODGA without any phase modifier and with 0.1M as well as 0.5M DHOA as the phase modifier. Transport behaviour of all the metal ions were found to be seriously affected with increasing radiation dose which was reflected in the decreasing percentage transport (%T) as well as permeability co-efficient (P) values. Though Sr(II) transport was quite significant with all the three unirradiated solvent systems, it was surprisingly low (<5%) when solvents exposed to 100 MRad dose were used in the SLM. Separation factors (S.F.) of the actinides over Sr(II) were calculated and were found to increase at higher radiation doses suggesting possibility of getting better decontamination on prolonged use of the supported liquid membrane system.

Facilitated transport of Pd(II) through a supported liquid membrane (SLM) containing N,N,N',N'-tetra-(2-ethylhexyl) thiodiglycolamide T(2EH)TDGA: a novel carrier.

A novel carrier, N,N,N',N'-tetra-(2-ethylhexyl) thiodiglycolamide, T(2EH)TDGA has been studied for transport of Pd(II) from nitric acid medium across a supported liquid membrane (SLM). Pd(II) was found to be almost quantitatively transported (≈ 99.9%) within 2h from 3.0M HNO(3) medium using 0.05 M T(2EH)TDGA in n-dodecane as carrier and 0.01 M thiourea in 0.2M HNO(3) as strippant. Pd(II) transport was also studied against various parameters like feed acidity, carrier concentration, membrane pore size, etc. Palladium transport was found to be diffusion controlled and the diffusion co-efficient value was found to be 3.56 × 10(-5)cm(2)/s. Selectivity of T(2EH)TDGA for palladium over other fission products was found to be quite high, with the separation factors for Pd, with respect to different fission products being >10(3). With respect to leaching out of carrier from the membrane support, the membrane was found to be stable for six consecutive cycles. Thus, T(2EH)TDGA can be used as an efficient carrier of Pd(II) from nitric acid medium.

Facilitated transport of uranium(VI) across supported liquid membranes containing T2EHDGA as the carrier extractant.

Facilitated transport of uranyl ion from nitric acid feed solutions was investigated across PTFE supported liquid membranes using N,N,N',N'-tetra-2-ethylhexyl-3-pentane-diamide (T2EHDGA) in n-dodecane as the carrier extractant containing 30% iso-decanol as the phase modifier. Solvent extraction studies indicated extraction of species of the type, UO(2)(NO(3))(2)·T2EHDGA. The distribution coefficients increased in the presence of NaNO(3) as compared to equivalent concentration of HNO(3) which was exactly the opposite of what was reported for Am(III)-TODGA extraction system. Supported liquid membrane studies indicated about 11h were required for quantitative transport of U(VI) from a feed of 3M HNO(3) using 0.2M T2EHDGA in n-dodecane containing 30% iso-decanol as the carrier extractant. Effect of various parameters such as feed acidity, T2EHDGA concentration, and nature of the strippant on the transport rate was investigated. The transport was found to be diffusion controlled in the membrane phase and the permeability coefficient was calculated to be (3.20 ± 0.13)× 10(-4)cm/s for the feed composition of 3M HNO(3), receiver phase composition of 0.01 M HNO(3) and membrane carrier phase of 0.2M T2EHDGA in n-dodecane containing 30% iso-decanol. The present results may be useful for the separation of U from lean solutions or radioactive wastes considered hazardous due to the presence of alpha-particle emitting radionuclides.

Near-infrared photoabsorption by C60 dianions in a storage ring.

We present a detailed study of the electronic structure and the stability of C(60) dianions in the gas phase. Monoanions were extracted from a plasma source and converted to dianions by electron transfer in a Na vapor cell. The dianions were then stored in an electrostatic ring, and their near-infrared absorption spectrum was measured by observation of laser induced electron detachment. From the time dependence of the detachment after photon absorption, we conclude that the reaction has contributions from both direct electron tunneling to the continuum and vibrationally assisted tunneling after internal conversion. This implies that the height of the Coulomb barrier confining the attached electrons is at least approximately 1.5 eV. For C(60)(2-) ions in solution electron spin resonance measurements have indicated a singlet ground state, and from the similarity of the absorption spectra we conclude that also the ground state of isolated C(60)(2-) ions is singlet. The observed spectrum corresponds to an electronic transition from a t(1u) lowest unoccupied molecular orbital (LUMO) of C(60) to the t(1g) LUMO+1 level. The electronic levels of the dianion are split due to Jahn-Teller coupling to quadrupole deformations of the molecule, and a main absorption band at 10,723 cm(-1) corresponds to a transition between the Jahn-Teller ground states. Also transitions from pseudorotational states with 200 cm(-1) and (probably) 420 cm(-1) excitation are observed. We argue that a very broad absorption band from about 11,500 cm(-1) to 13,500 cm(-1) consists of transitions to so-called cone states, which are Jahn-Teller states on a higher potential-energy surface, stabilized by a pseudorotational angular momentum barrier. A previously observed, high-lying absorption band for C(60)(-) may also be a transition to a cone state.

Heat capacities of freely evaporating charged water clusters.

We report on evaporation studies on positively charged water clusters (H(+)(H(2)O)(N)) and negatively charged mixed clusters (X(-)(H(2)O)(N)) with a small core ion X (X=O(2), CO(3), or NO(3)), in the size range N=5-300. The clusters were produced by corona discharge in ambient air, accelerated to 50 keV and mass selected by an electromagnet. The loss of monomers during the subsequent 3.4 m free flight was recorded. The average losses are proportional to the clusters' heat capacities and this allowed the determination of size-dependent heat capacities. The values are found to increase almost linearly with clusters size for both species, with a rate of 6k(B)-8k(B) per added molecule. For clusters with N<21 the heat capacities per molecule are lower but the incremental increase higher. For N>21 the values are intermediate between the bulk liquid and the solid water 0 degrees C values.