Synthesis,Characterization and Biological Evaluation of New 3,5-Disubstituted-Pyrazoline Derivatives as Potential Anti-Mycobacterium tuberculosis H37Ra Compounds

A total of fourteen pyrazoline derivatives were synthesized through cyclo-condensation reactions by chalcone derivatives with different types of semicarbazide. These compounds were characterized by IR, 1D-NMR (¹H, ¹³C and Distortionless Enhancement by Polarization Transfer - DEPT-135) and 2D-NMR (COSY, HSQC and HMBC) as well as mass spectroscopy analysis (HRMS). The synthesized compounds were tested for their antituberculosis activity against Mycobacterium tuberculosis H37Ra in vitro. Based on this activity, compound 4a showed the most potent inhibitory activity, with a minimum inhibitory concentration (MIC) value of 17 μM. In addition, six other synthesized compounds, 5a and 5c–5g, exhibited moderate activity, with MIC ranges between 60 μM to 140 μM. Compound 4a showed good bactericidal activity with a minimum bactericidal concentration (MBC) value of 34 μM against Mycobacterium tuberculosis H37Ra. Molecular docking studies for compound 4a on alpha-sterol demethylase was done to understand and explore ligand–receptor interactions, and to hypothesize potential refinements for the compound.     

Fabrication of Alginate-Based O/W Nanoemulsions for Transdermal Drug Delivery of Lidocaine: Influence of the Oil Phase and Surfactant

Transdermal drug delivery of lidocaine is a good choice for local anesthetic delivery. Microemulsions have shown great effectiveness for the transdermal transport of lidocaine. Oil-in-water nanoemulsions are particularly suitable for encapsulation of lipophilic molecules because of their ability to form stable and transparent delivery systems with good skin permeation. However, fabrication of nanoemulsions containing lidocaine to provide an extended local anesthetic effect is challenging. Hence, the aim of this study was to address this issue by employing alginate-based o/w nanocarriers using nanoemulsion template that is prepared by combined approaches of ultrasound and phase inversion temperature (PIT). In this study, the influence of system composition such as oil type, oil and surfactant concentration on the particle size, in vitro release and skin permeation of lidocaine nanoemulsions was investigated. Structural characterization of lidocaine nanoemulsions as a function of water dilution was done using DSC. Nanoemulsions with small droplet diameters (d < 150 nm) were obtained as demonstrated by dynamic light scattering (DLS) and cryo-TEM. These nanoemulsions were also able to release 90% of their content within 24-h through PDMS and pig skin and able to the drug release over a 48-h. This extended-release profile is highly favorable in transdermal drug delivery and shows the great potential of this nanoemulsion as delivery system.     

Effect of static disorder in an electron Fabry-Perot interferometer with two quantum scattering centers

In a recent paper—F. Ciccarello et al., New J. Phys. 8, 214 (2006)—we have demonstrated that the electron transmission properties of a one-dimensional (1D) wire with two identical embedded spin-1/2 impurities can be significantly affected by entanglement between the spins of the scattering centers. Such an effect is of particular interest in the control of the transmission of quantum information in nanostructures and can be used as a detection scheme of maximally entangled states of two localized spins. In this letter, we relax the constraint that the two magnetic impurities are equal and investigate how the main results presented in the above paper are affected by a static disorder in the exchange coupling constants of the impurities. Good robustness against deviation from impurity symmetry is found for both the entanglement dependent transmission and the maximally entangled states generation scheme.     

Influence of structural and chemical properties on electron transport in mesoporous ZnO-based dye-sensitized solar cell

Ionics - Two chemical bath deposition (CBD) solutions were prepared at two different temperatures of 60 and 80&nbsp;°C for dye-sensitized solar cell (DSSC) application. The deposition time...     

Stability-Indicating Densitometric High-Performance Thin-Layer Chromatographic Method for the Quantitative Analysis of Biomarker Naringin in the Leaves and Stems of Rumex vesicarius L.

JPC – Journal of Planar Chromatography – Modern TLC - A simple, sensitive, and stability-indicating high-performance thinlayer chromatography (HPTLC)-densitometric method was developed...     

Water‐Stable Zirconium‐Based Metal–Organic Framework Material with High‐Surface Area and Gas‐Storage Capacities

We designed, synthesized, and characterized a new Zr‐based metal–organic framework material, NU‐1100 , with a pore volume of 1.53 ccg^?1 and Brunauer–Emmett–Teller (BET) surface area of 4020 m²g^?1; to our knowledge, currently the highest published for Zr‐based MOFs. CH₄/CO₂/H₂ adsorption isotherms were obtained over a broad range of pressures and temperatures and are in excellent agreement with the computational predictions. The total hydrogen adsorption at 65 bar and 77 K is 0.092 g g^?1, which corresponds to 43 g L^?1. The volumetric and gravimetric methane‐storage capacities at 65 bar and 298 K are approximately 180 v_STP/v and 0.27 g g^?1, respectively.     

Mixed solvents for cellulose derivatization under homogeneous conditions: kinetic,spectroscopic, and theoretical studies on the acetylation of the biopolymer in binary mixtures of an ionic liquid and molecular solvents

Rate constants for the acetylation of microcrystalline cellulose (MCC), by ethanoic anhydride in the presence of increasing concentrations of the ionic liquid (IL), 1-allyl-3-methylimidazolium chloride in dipolar aprotic solvents (DAS), N,N-dimethylacetamide (DMAC), and acetonitrile (MeCN), have been calculated from conductivity data. The third order rate constants showed a linear dependence on [IL]. We explain this result by assuming that the reacting cellulose is hydrogen-bonded to the IL. This is corroborated by kinetic data of the acetylation of cyclohexylmethanol, FTIR of the latter compound and of cellobiose in mixtures of IL/DAS, and conductivity of the binary solvent mixtures in absence, and presence of MCC. Cellulose acetylation is faster in IL/DMAC than in IL/MeCN; this difference is explained based on solvatochromic data (empirical polarity and basicity) and molecular dynamics simulations. Results of the latter indicate hydrogen-bond formation between the hydroxyl groups of the anhydroglucose unit of MCC, (Cl^?) of the IL, and the dipole of the DMAC. Under identical experimental conditions, acetylation in IL/DMAC is faster than that in LiCl/DMAC (2.7–8 times), due to differences in the enthalpies and entropies of activation.     

Ionizable Amphiphilic Dendrimer‐Based Nanomaterials with Alkyl‐Chain‐Substituted Amines for Tunable siRNA Delivery to the Liver Endothelium In Vivo

A library of dendrimers was synthesized and optimized for targeted small interfering RNA (siRNA) delivery to different cell subpopulations within the liver. Using a combinatorial approach, a library of these nanoparticle‐forming materials was produced wherein the free amines on multigenerational poly(amido amine) and poly(propylenimine) dendrimers were substituted with alkyl chains of increasing length, and evaluated for their ability to deliver siRNA to liver cell subpopulations. Interestingly, two lead delivery materials could be formulated in a manner to alter their tissue tropism within the liver—with formulations from the same material capable of preferentially delivering siRNA to 1) endothelial cells, 2) endothelial cells and hepatocytes, or 3) endothelial cells, hepatocytes, and tumor cells in vivo. The ability to broaden or narrow the cellular destination of siRNA within the liver may provide a useful tool to address a range of liver diseases.     

Long-Lived Charge-Transfer State Induced by Spin-Orbit Charge Transfer Intersystem Crossing (SOCT-ISC) in a Compact Spiro Electron Donor/Acceptor Dyad

We prepared conceptually novel, fully rigid, spiro compact electron donor (Rhodamine B, lactam form, RB)/acceptor (naphthalimide; NI) orthogonal dyad to attain the long-lived triplet charge-transfer (³CT) state, based on the electron spin control using spin-orbit charge transfer intersystem crossing (SOCT-ISC). Transient absorption (TA) spectra indicate the first charge separation (CS) takes place within 2.5 ps, subsequent SOCT-ISC takes 8 ns to produce the ³NI* state. Then the slow secondary CS (125 ns) gives the long-lived ³CT state (0.94 μs in deaerated n-hexane) with high energy level (ca. 2.12 eV). The cascade photophysical processes of the dyad upon photoexcitation are summarized as ¹NI*→¹CT→³NI*→³CT. With time-resolved electron paramagnetic resonance (TREPR) spectra, an EEEAAA electron-spin polarization pattern was observed for the naphthalimide-localized triplet state. Our spiro compact dyad structure and the electron spin-control approach is different to previous methods for which invoking transition-metal coordination or chromophores with intrinsic ISC ability is mandatory.