Line graph eigenvalues and line energy of caterpillars

The energy of a graph G is the sum of the absolute values of the eigenvalues of the adjacency matrix of G. A caterpillar is a tree in which the removal of all pendant vertices makes it a path. Let d?3 and n?2(d-1). Let p=[p₁,p₂,…,p_d-1] with p₁?1,p₂?1,…,p_d-1?1 such that

p₁+p₂+?+p_d-1=n-d+1.     

High proton conduction in a chiral ferromagnetic metal-organic quartz-like framework

A complex-as-ligand strategy to get a multifunctional molecular material led to a metal-organic framework with the formula (NH(4))(4)[MnCr(2)(ox)(6)]·4H(2)O. Single-crystal X-ray diffraction revealed that the anionic bimetallic coordination network adopts a chiral three-dimensional quartz-like architecture. It hosts ammonium cations and water molecules in functionalized channels. In addition to ferromagnetic ordering below T(C) = 3.0 K related to the host network, the material exhibits a very high proton conductivity of 1.1 × 10(-3) S cm(-1) at room temperature due to the guest molecules.     

Intercompany Study to Evaluate the Robustness of Capillary Isoelectric Focusing Technology for the Analysis of Monoclonal Antibodies

Interlaboratory comparisons are essential to bringing emerging technologies into biopharmaceutical industry practice and regulatory acceptance. As a result, an international team including 12 laboratories from 10 independent biopharmaceutical companies in the United States and Switzerland was formed to evaluate the precision and robustness of capillary isoelectric focusing (CIEF) to assess the charge heterogeneity of monoclonal antibodies. The different laboratories determined the apparent pI and the relative distribution of the charge isoforms of a representative monoclonal antibody (rMAb) sample using the same CIEF method. Statistical evaluation of the data was performed to determine within and between-laboratory consistencies and outlying information. The apparent pI data generated for each charge variant peak showed very good precision between laboratories with percentage of RSD values of ??0.5%. Similarly, the percentage of RSD for the rMAb charge variants percent peak area values are ??4.4% across different laboratories with different analysts using different lots of ampholytes and multiple instruments. Taken together, these results validate the appropriate use of CIEF in the biopharmaceutical industry in support of regulatory submissions.     

Lanthanide(III)/pyrimidine-4,6-dicarboxylate/oxalate extended frameworks: a detailed study based on the lanthanide contraction and temperature effects

Detailed structural, magnetic, and luminescence studies of six different crystalline phases obtained in the lanthanide/pyrimidine-4,6-dicarboxylate/oxalate system have been afforded: {[Ln(μ-pmdc)(μ-ox)(0.5)(H(2)O)(2)]·3H(2)O}(n) (1-Ln), {[Ln(μ-pmdc)(μ-ox)(0.5)(H(2)O)(3)]·2H(2)O}(n) (2-Ln), {[Ln(μ(3)-pmdc)(μ-ox)(0.5)(H(2)O)(2)]·~2.33H(2)O}(n) (3-Ln), {[Ln(2)(μ(3)-pmdc)(μ(4)-pmdc)(μ-ox)(H(2)O)(3)]·5H(2)O}(n) (4-Ln), {[Ln(μ(3)-pmdc)(μ-ox)(0.5)(H(2)O)(2)]·H(2)O}(n) (5-Ln), and [Ln(pmdc)(1.5)(H(2)O)(2.5)] (6-Ln). The slow generation of the oxalate (ox) anion, obtained from the in situ partial hydrothermal decomposition of the pyrimidine-4,6-dicarboxylate (pmdc) ligand, allows us to obtain good shaped single crystals, while direct addition of potassium oxalate provides the same compounds but as polycrystalline samples. The crystal structures of all compounds are based on the double chelation established by the pmdc and ox ligands to provide distorted 2D honeycomb layers that, in some cases, are fused together, leading to 3D systems, by replacing some of the coordinated water molecules that complete the coordination sphere of the lanthanide by uncoordinated carboxylate oxygen atoms of the pmdc. The presence of channels occupied by crystallization water molecules is also a common feature with the exception of compounds 5-Ln. It is worth noting that compounds 3-Ln present a commensurate crystal structure related to the partial occupancy of the crystallization water molecules placed within the channels. Topological analyses have been carried out, showing a previously nonregistered topology for compounds 4-Ln, named as jcr1. The crystal structures are strongly dependent on the lanthanide ion size and the temperature employed during the hydrothermal synthesis. The lanthanide contraction favors crystal structures involving sterically less hindranced coordination environments for the final members of the lanthanide series. Additionally, reinforcement of the entropic effects at high temperatures directs the crystallization process toward less hydrated crystal structures. The magnetic data of these compounds indicate that the exchange coupling between the lanthanide atoms is almost negligible, so the magnetic behavior is dominated by the spin-orbit coupling and the ligand field perturbation. The luminescence properties that exhibit the compounds containing Nd(III), Eu(III), and Tb(III) have been also characterized.     

(N-heterocyclic carbene)-Pd-catalyzed anaerobic oxidation of secondary alcohols and domino oxidation-arylation reactions

The use of commercially available (SIPr)Pd(cinnamyl)Cl (SIPr = 1,3-bis(2,6-diisopropylphenyl)-4,5-dihydroimidazol-2-ylidene) as a precatalyst for the anaerobic oxidation of secondary alcohols is described. The use of this complex allows for a drastic reduction in the reaction times and catalyst loading when compared to the unsaturated counterpart. This catalytic system is compatible with the use of microwave dielectric heating, decreasing even further catalyst loading and reaction times. Domino Pd-catalyzed oxidation-arylation reactions of secondary alcohols are also presented.     

Synthesis of cationic quantum dots via a two-step ligand exchange process

A new class of quaternary ammonium derivatives has been used to synthesize cationic CdSe/ZnS quantum dots with exceptional stability in water as well as in biological media.     

Radon hydrides: structure and bonding

Quantum chemical calculations, using gradient-correct density functional at the BP86 level in conjunction with TZ2P basis sets, have been carried out for the radon hydrides HRnY (with Y = F, Cl, Br, I, CCH, CN, and NC). The bonding in HRnY is studied using different bond ruptures, establishing the role of those stabilizing (and destabilizing) factors that prevent these species to be dissociated. Although all HRnY systems studied here are bound equilibrium structures, they are metastable species with respect to the HRnY → Rn + HY decomposition channel. However, the HRnY → H + Rn + Y reaction is endothermic. So, these results indicate the possibility to identify the radon hydrides in noble-gas matrices.     

Neutron interferometry: lessons in experimental quantum mechanics,wave-particle duality,and entanglement,Second edition

Production, Pollution, Protection (Wykeham Science Series No. 19). By W. B. Yapp. (Wykeham Publications (London) Ltd., 1972.) [Pp. x + 184.] Cloth £2.75; paper £2.00. Saope: Survey; Level: General reader.

Elementary Radiation Physics. By G. S. Hurst and J. E. Turner. (John Wiley &; Sons Ltd., 1970.) [Pp. xi+ 166.] £3.50. Scope: Textbook. Level: Undergraduate.

Exploring Physics. Book Five. By Tom Duncan. (John Murray, 1970.) [Pp. vi+218.] Cased £1.30; Limp £1.05. Scope: Textbook. Level: School.

Biological Effects of Radiation. By J. E. Coggle. (Wykeham Publications, 1971.) [Pp. vii+ 149.] £2.00. Scope: Undergraduate; library.

Mathematical Methoda for Phyaickta. (2nd Edn.) By George Arfken. (Academic Press, 1970.) [Pp. vii + 81r.] £6 15s. Od. Scope: Treatise/textbook. Level: Postgraduate; undergraduate.

Elementary Differential Equations. By R. L. E. Sohwarzenberger. (Chapman &; Hell, 1970.) [Pp. xii 98.] Scope: Treatise/textbook. Level: Undergraduate.

Tdlegen's Theorem and Electrical Networks. By Paulpeneield, Jr., Robert Spengeand, S. Duinker. (M. I. T. Press, 1970.) [Pp. xv +143.] £3.50 Scope: Treatise/textbook. Level : Specialist/postgraduate; undergraduate.

Lecture Notes in Physics. The Reduction of the Product of Two Irreducible Unitary Representations of the Proper Orthochronous, Quoratum-mechanical Poincare Group. By Manfbzd Schaaf. (Springer-Verlag, 1971.) [Pp. iv + 120.] £5.50. Scope : Treatise/textbook. Level: For specialists only.

The Engineering Uses of Holography. Edited by E. R. Robertson and J. M. HARVEY. (Cambridge University Press, 1970.) [Pp. xxx + 589.] £15.00. Scope: Conference proceedings. Level: Specialist/postgraduate.

Band Themy of Metals. The Elements. By S. L. Altmann. (Pergamon Group Press, 1970.) [Pp. 250.] Hard cover £2.50; Flexi-cover £1.75. Scope: Textbook. Level: Undergraduate.

The Growth and Structure of Eutectica with Siliwn and Germanium. A. Hellawell. (Pergamon Press, 1970.) [Pp. 78.] £1.25. Scope: Survey. Level: Specialist/postgraduate.

Fieield-Ion Microscopy. By K. M. Bowkett and D. A. Smite. (North-Holland Publishing Co., 1970.) [Pp. x+ 257.] £6.30. Scope: Survey. Level: Specialist/postgraduate.

The Physics of Amorpbow, Materiala. (Science Research Council, 1970.) [Pp. 54.] Scope: Survey. Level: For specialists only; general reader; specialist/postgraduate.

SI Units: An Introduction for A-level. By M. Nelkon. (Chatto &; Windus, 1970) [Pp. 88.] £0.30. Scope: Textbook. Level: School.

Nuclear Physioa. By K. N. Mukhin. (MacDonald Technical and Scientific, 1970.) [Pp. xiv+ 505.] £5. Level: Undergraduate.

Glass Lasers. By K. Patek. (Butterworth Group, 1970.) [Pp. xi+217.] £6.50. Scope: Treatise/textbook; library; library (reference). Level: For specialist only; specialist/post-graduate.

Radio Astrophysics. By A. G. Pacholczyk. (W. H. Freeman &; Co., 1970.) [Pp. xxi+ 269.] £6.10. Scope: Textbook. Level :Specialist/postgraduate.

Transistors in Linear Circuits. By R. W. A. Scarr. (George G. Harrap &; Co., Ltd., 1970.) [Pp. 206.] £2.25. Scope: Textbook. Level: Undergraduate.

La Thermoélectricité By André Linder. (Presses Universitaires de France, 1970.) [Pp. 123.] Scope: Textbook. Level: Specialist/postgraduate.

Diffusion in Semiconductors. By B. L. Sharma. (Trans Tech. Publications, 1970.) [Pp. 200.] $9.80. Scope: Survey. Level: Specialist/postgraduate.

Méthods Numdriques pour la Prévision du Temps. By G. I. NARTCHUK.(Librairie Armand Colin, 1970.) [Pp. 343.] Scope: Treatise/textbook. Level: Specialist/post-graduate.

Mathematical and Theoretical Physics. Vols. I and 11. By Eqil A. Hylleraas. (John Wiley &; Sons, 1970.) [Vol. I, pp. xxii+ 485; Vol. 11, pp. xxi+ 474.] £7.00 each. Scope: Textbook. Level :Post-graduate/ undergraduate.

The Atom and the Universe. By James S. Perlman. (Wadsworth Publishing Co., Inc., 1970.) [Pp. 633.]

Understanding and Measuring vibrations. By R. H. Wallace. (Wykeham Publications Ltd. 1970.) [Pp. xii+ 148.] £1.50. Scope: Survey; library; library (reference). Level: General reader; undergraduate; school.

A Quantum Approach to the Solid State. By Philip L. TAYLOR. (Prentice-Hall, Inc., 1970.) [Pp. xii+ 322.] Scope: Treatise/textbook. Level: Specialist/postgraduate.

Elementary Atomic Structure. By G. K. WOODGATE. (McGraw-Hill Publishing Co. Ltd., 1970.) [Pp. viii + 223.] £3.40. Scope: Textbook; library. Level: undergraduate.

Progress in Quantum Electronics. Vol. 1: The Semiclosaical Theory of the Gas Laser. Edited by J. H. Sanders and K. W. H. Stevens. (Pergamon Press, 1970.) [Pp. 271.] £1.50. Scope: Treatise/textbook. Level: Specialist/postgraduate.

Chemical Kinetics. By B. Stevens. (Chapman &; Hall Ltd., 1970.) [Pp. viii + 110.] £0.60. Scope: Textbook; library. Level: Undergraduate; school.

Electromagnetic Fields and Waves. (Second Edition) By Paul Lorrain and Dale R. Corson. (W. H. Freeman &; Co., Ltd., 1970.) [Pp. xxv+ 706.] £4.00. (also available in cloth £7.00.) Scope: Textbook. Level: Undergraduate.

Theoretical Physics. (an advanced text.) By Benjamin G. Levich. (North-Holland. Pub. Co., 1971.) [Pp. xviii+ 395.] £5.50. Scope: Textbook. Level: Undergraduate.

Sources of Plcrema Physics (I). By H. S. Green and R. B. Leipnik. (Wolters-Noordhoff Publishing, 1971.) [Pp. 630.] scope: Treatise. Level: Specialist/postgraduate.

Molecular Acowrtiw. By A. J. Matoeson. (John Wiley, 1971.) [Pp. xv+290.] £5.50.

Fourier Methods in Crystallography. By G. N. Ramachandran and R. Srinivasan. (John Wiley Ltd, 1971.) [Pp. xiii+ 259.] £7.50 Scope: Treatise/textbook. Level: Specialist/ postgraduate.

Carl Friedrich Gauss. A Biography by Tord Hall, Translated by Albert Froderbero (The M.I.T. Press, 1971.) [Pp.175.] £3.75. Scope: Treatise. Level: Specialist/postgraduate; undergraduate.

Elements of Hamiltonian Mechanics. By D. Ter Haar. (Pergamon Press Ltd., 1971.) [Pp. viii+ 201.] £2.50; $6.75. Scope: Textbook. Level: Postgraduate; undergraduate.

Collection of Problems in Classical Mechanics. By G. L. Kotein and V. G. Serbo. (Pergamon Press Ltd., 1971.) [Pp. viii+ 278.] £3.00. Level: Postgraduate; undergraduate.

Relativistic Quantum Theory. (Part 1.) By V. B. Berestetskii, E. M. Lifshitz and L. P. Pitaevskii. (Pergamon Press, 1971.) [Pp. xv+ 375.] £6.00. Scope: Treatiseltextbook. Level: Specialist/postgraduate.

Direct Nuclear Reaction Theories. By Norman Austern. (John Wiley &; Sons Ltd., 1970.) [Pp. ix+ 390.] £9.50. Scope: Treatise/textbook; survey; library. Level: Specialist/postgraduate.

The Seientific Papers of G. I. Taylor. Vol. 4. Edited by G. K. Batchelor. (Cambridge University Press, 1971.) [Pp. ix+ 579.] £12.00.

Qwznlum Physica. Berkeley Physics Course-Vol. 4. By Ewind H. Wiohmann. (McGraw-Hill, 1971.) [Pp. xvii + 421.] £3.35. Scope Textbook. Level Undergraduate.

Spin Fomrmlisms. By Sue Urk Chunq. (CERN, Geneva, 1971.) [Pp. v+81.] Scope: Survey. Level: Specialist/postgraduate.

Applications of Holography. Edited by E. S. Barreeette et al. (Proceedings of the U.S.—Japan Seminar at Washington D.C., 1969, 1971.) [Pp. viii+ 395.] $16.50. Scope: Conference proceedings. Level: For specialists only; General reader.

High-Energy Physics and Nuclear Structure. Edited by S. Devons. (Plenum Press, 1971.) [Pp. xli+ 859.] $37.50. Scope: Conference proceedings; library (reference). Level: For specialist only; specialist/postgrduate.     

Tribochemical nanolithography: selective mechanochemical removal of photocleavable nitrophenyl protecting groups with 23 nm resolution at speeds of up to 1 mm s−1

We describe the mechanochemical regulation of a reaction that would otherwise be considered to be photochemical, via a simple process that yields nm spatial resolution. An atomic force microscope (AFM) probe is used to remove photocleavable nitrophenyl protecting groups from alkylsilane films at loads too small for mechanical wear, thus enabling nanoscale differentiation of chemical reactivity. Feature sizes of 20–50 nm are achieved repeatably and controllably at writing rates up to 1 mm s⁻¹. Line widths vary monotonically with the load up to 2000 nN. To demonstrate the capacity for sophisticated surface functionalisation provided by this strategy, we show that functionalization of nanolines with nitrilo triacetic acid enables site-specific immobilization of histidine-tagged green fluorescent protein. Density functional theory (DFT) calculations reveal that the key energetic barrier in the photo-deprotection reaction of the nitrophenyl protecting group is excitation of a π–π* transition (3.1 eV) via an intramolecular charge-transfer mechanism. Under modest loading, compression of the adsorbate layer causes a decrease in the N–N separation, with the effect that this energy barrier can be reduced to as little as 1.2 eV. Thus, deprotection becomes possible via either absorption of visible photons or phononic excitation transfer, facilitating fast nanolithography with a very small feature size.

Photolithography without optics: compression of nitrophenyl protecting groups under an atomic force microscope probe modifies their electronic structure and reduces the energy barrier to deprotection, enabling nanolithography without UV light.