QCD mini-jets contribution to the total cross-section for pions and protons and expectations at LHC

We describe our kt-resummation model for total cross-sections and show its application to pp and ¯pp scattering. The model uses mini-jets to drive the rise of the cross-section and soft gluon resummation in the infrared region to transform the violent rise of the mini-jet cross-section into a logarithmic behaviour in agreement with the Froissart bound.

An Expeditious Enantiospecific Total Synthesis of (-)-Crassalactone C

A concise and expeditious approach for the total synthesis of bioactive styryllactone (-)-crassalactone C is presented from tartaric acid. The main features of the synthesis include the desymmetrization of dimethylamide of tartaric acid and the effective use of cinnamoyl ester as a protecting group as well as a reactant in the ring-closing metathesis reaction.

Total internal reflection (TIR) Raman tribometer: a new tool for in situ study of friction-induced material transfer

The sliding history in friction-induced material transfer of dry 2H-MoS2 particles in a sheared contact was studied. Video images in contact showed fragmentation of lubricant particles and build-up of a transfer film, and were used to measure the speed of fragmented particles in the contact region. Total internal reflection (TIR) Raman spectroscopy was used to follow the build-up of the MoS2 transfer film. A combination of in situ and ex situ analysis of the mating bodies revealed the thickness of the transfer film at steady state to be of the order of 35 nm on the ball surface and 15 nm on the flat substrate. Insights into the mechanism of formation of the transfer film in the early stages of sliding contact are deduced.

Total synthesis and determination of the absolute configuration of 5,6-Dihydro-alpha-pyrone natural product synargentolide B

Enantiospecific total synthesis and determination of the absolute stereochemistry of the alpha-pyrone-containing natural product synargentolide B were accomplished. The absolute stereochemistry of the natural product was established by synthesizing the possible diastereomers and comparison of the data with those reported for the natural product. During the process, total synthesis of the putative structure of related natural product 6R-1S,2R,SR,6S-(tetraacetyloxy)-3E-heptenyl]-5,6-dihydro-2H-pyran-2-o ne was also accomplished and confirmed by X-ray crystal structure analysis. Wittig-Horner reaction of a chiral phosphonate derived from (S)-lactic acid and ring-closing metathesis were the key reactions during the course of the total synthesis.

Enantiospecific total synthesis of indole alkaloids (+)-eburnamonine, (-)-aspidospermidine and (-)-quebrachamine

An enantiospecific total synthesis of indole alkaloids eburnamonine, aspidospermidine and quebrachamine is described from lactic acid. Synthesis of all three alkaloids is accomplished from a single chiral building block. Johnson-Claisen rearrangement of a chiral allyl alcohol is the main feature for the installation of the required quaternary centre.

Total Synthesis of (+)-Pinellic Acid

A straightforward strategy for the synthesis of (+)-pinellic acid in 16% overall yield and 13 steps, starting from (1R)-1-(furan-2-yl)hexan-1-ol, is described. Key reactions in the synthesis include a Sharpless kinetic resolution, oxidation of a protected furan to reveal a but-2-ene-1,4-dione moiety, and an asymmetric reduction.

Total Synthesis of (+)-Seimatopolide A

Total synthesis of 10-membered lactone (+)-seimatopolide A is presented from furfural. Key reactions in the present strategy include the effective use of furan as a E-but-2-ene-1,4-dione surrogate, Nagao acetate aldol reaction, and Shiina lactonization.

Minimizing total weighted tardiness on heterogeneous batch processors with incompatible job families

In this paper, we address a scheduling problem for minimizing total weighted tardiness. The background for the paper is derived from the automobile gear manufacturing process. We consider the bottleneck operation of heat treatment stage of gear manufacturing. Real-life scenarios like unequal release times, incompatible job families, nonidentical job sizes, heterogeneous batch processors, and allowance for job splitting have been considered. We have developed a mathematical model which takes into account dynamic starting conditions. The problem considered in this study is NP-hard in nature, and hence heuristic algorithms have been proposed to address it. For real-life large-size problems, the performance of the proposed heuristic algorithms is evaluated using the method of estimated optimal solution available in literature. Extensive computational analyses reveal that the proposed heuristic algorithms are capable of consistently obtaining near-optimal statistically estimated solutions in very reasonable computational time.

An Approach to a Bislactone Skeleton: A Scalable Total Synthesis of (+/-)-Penifulvin A

An efficient and scalable total synthesis of the architecturally challenging sesquiterpenoid (+/-)-penifulvin A has been accomplished via a 12-step sequence with an overall yield of 16%. For the construction of this structurally complex tetracyclic molecule, the key steps used included 1,4-conjugate addition, a Pd(0) catalyzed cross-coupling reaction between an enol phosphate and trimethyl aluminum, Claisen rearrangement using the Johnson orthoester protocol, Ti(III)-mediated reductive epoxide opening-cyclization, Lewis acid catalyzed epoxy-aldehyde rearrangement, and finally a substrate controlled oxidative cascade lactonization process.

Total internal reflection Raman spectroscopy of poly(alpha-olefin) oils in a lubricated contact

The rheology of a poly(alpha-olefin) base oil (PAO) in a sliding point contact has been investigated by total internal reflection (TIR) Raman spectroscopy. TIR Raman has the sensitivity to analyse nanometer-thick lubricant films in a tribological contact. The Raman signal generated from the sliding contact was used to determine the lubricant film thickness. The experimentally obtained film thicknesses were compared with theoretical calculations and a transition from Newtonian to non-Newtonian behaviour was observed at high shear rates. The Raman spectra showed no significant changes in the conformation of the PAO chains under the applied conditions of pressure and shear, but the polarisation dependence of the spectra revealed a preferred orientation of the hydrocarbon side chains in the shear-thinned region. Monolayers formed by a boundary lubricant, arachidic acid, dissolved in the PAO could be detected on the surfaces in the elastohydrodynamic regime.

Total synthesis of the indole alkaloids henrycinol A and B

The total synthesis of new indole alkaloids henrycinol A and B were accomplished starting from L-tryptophan methyl ester. The key step is a stereochemically flexible Pictet-Spengler reaction governed by the presence or absence of an N-allyl group in the tryptophan precursor. The natural products henrycinol A and B were synthesized in good overall yield in eight and nine steps, respectively. (C) 2014 Elsevier Ltd. All rights reserved.

Total synthesis of (+)-anamarine

An enantiospecific total synthesis of polyhydroxy delta-pyrone natural product (+)-anamarine is accomplished. The main features of the synthesis include the stereoselective reduction of the ketone obtained by the desymmetrization of the bis-dimethyl amide of tartaric acid and further elaboration involving asymmetric Brown's allylation and ring closing metathesis. (C) 2014 Elsevier Ltd. All rights reserved.

Toward the total synthesis of a lagunamide B analogue

Lagunamides, isolated from a marine cyanobacterium Lyngbya majuscule found in Singapore, showed very potent activities against Plasmodium falciparum and murine leukemia cell line (P388). Herein, a concise synthetic approach toward the total synthesis of a lagunamide B analogue is discussed. Macrolactonization, HWE-olefination, and modified Crimmin's aldol are some of the key reactions featured in this synthesis. (C) 2014 Elsevier Ltd. All rights reserved.

Enantiospecific Total Synthesis of Macrolactone Sch 725674

The enantiospecific total synthesis of 14-membered macrolactone Sch 725674 was accomplished from tartaric acid. Key reactions in the synthesis include the Ley's dithiaketalization of an alkynone derived from the bis-Weinreb amide of tartaric acid, Boord olefination, and ring-closing metathesis of an acrylate ester.

Hydrogen bonding, halogen bonding and lithium bonding: an atoms in molecules and natural bond orbital perspective towards conservation of total bond order, inter- and intra-molecular bonding

One hundred complexes have been investigated exhibiting D-X center dot center dot center dot A interactions, where X = H, Cl or Li and DX is the `X bond' donor and A is the acceptor. The optimized structures of all these complexes have been used to propose a generalized `Legon-Millen rule' for the angular geometry in all these interactions. A detailed Atoms in Molecules (AIM) theoretical analysis confirms an important conclusion, known in the literature: there is a strong correlation between the electron density at the X center dot center dot center dot A bond critical point (BCP) and the interaction energy for all these interactions. In addition, we show that extrapolation of the fitted line leads to the ionic bond for Li-bonding (electrostatic) while for hydrogen and chlorine bonding, it leads to the covalent bond. Further, we observe a strong correlation between the change in electron density at the D-X BCP and that at the X center dot center dot center dot A BCP, suggesting conservation of the bond order. The correlation found between penetration and electron density at BCP can be very useful for crystal structure analysis, which relies on arbitrary van der Waals radii for estimating penetration. Various criteria proposed for shared-and closed-shell interactions based on electron density topology have been tested for H/Cl/Li bonded complexes. Finally, using the natural bond orbital (NBO) analysis it is shown that the D-X bond weakens upon X bond formation, whether it is ionic (DLi) or covalent (DH/DCl) and the respective indices such as ionicity or covalent bond order decrease. Clearly, one can think of conservation of bond order that includes ionic and covalent contributions to both D-X and X center dot center dot center dot A bonds, for not only X = H/Cl/Li investigated here but also any atom involved in intermolecular bonding.