Design, synthesis, conformational analysis and nucleic acid hybridisation properties of thymidyl pyrrolidine-amide oligonucleotide mimics (POM)

Pyrrolidine-amide oligonucleotide mimics (POM) 1 were designed to be stereochemically and conformationally similar to natural nucleic acids, but with an oppositely charged, cationic backbone. Molecular modelling reveals that the lowest energy conformation of a thymidyl-POM monomer is similar to the conformation adopted by ribonucleosides. An e cient solution phase synthesis of the thymidyl POM oligomers has been developed, using both N-alkylation and acylation coupling strategies. 1H NMR spectroscopy con rmed that the highly water soluble thymidyl-dimer, T2-POM, preferentially adopts both a con guration about the pyrrolidine N-atom and an overall conformation in D2O that are very similar to a typical C3 -endo nucleotide in RNA. In addition the nucleic acid hybridisation properties of a thymidyl-pentamer, T5-POM, with an N-terminal phthalimide group were evaluated using both UV spectroscopy and surface plasmon resonance (SPR). It was found that T5-POM exhibits very high a nity for complementary ssDNA and RNA, similar to that of a T5-PNA oligomer. SPR experiments also showed that T5-POM binds with high sequence delity to ssDNA under near physiological conditions. In addition, it was found possible to attenuate the binding a nity of T5-POM to ssDNA and RNA by varying both the ionic strength and pH. However, the most striking feature exhibited by T5-POM is an unprecedented kinetic binding selectivity for ssRNA over DNA

As safe as houses? Why standards for urban development matter

Standards for designing, improving, and maintaining the built environment have conceptual and practical value for health. Yet, their importance runs the risk of being subsumed in tangential discourses, including over their applicability for particular populations or in particular contexts. This paper applies an integrative systems perspective to several relevant scenarios, while broadly revisiting the health rationale for built environment standards. As with any intervention, standards can have negative unintended consequences, in some cases inducing adverse outcomes. Yet, forgoing standards is not an acceptable answer for sustainable urbanization. The systems perspective adopted here surveys some of the driving forces that underlie adverse outcomes, and suggests potential leverage points and criteria for action

A mouse model of lamellar intrastromal femtosecond laser keratotomy: ultra-structural, inflammatory, and wound healing responses

Molecular Vision173005-3012MVEP

Effect of dispase denudation on amniotic membrane

Molecular Vision151962-197

Quantum Cryptography Using Single Particle Entanglement

A quantum cryptography scheme based on entanglement between a single particle state and a vacuum state is proposed. The scheme utilizes linear optics devices to detect the superposition of the vacuum and single particle states. Existence of an eavesdropper can be detected by using a variant of Bell's inequality.Comment: 4 pages, 3figures, revte

Single-particle nonlocality and entanglement with the vacuum

We propose a single-particle experiment that is equivalent to the conventional two-particle experiment used to demonstrate a violation of Bell's inequalities. Hence, we argue that quantum mechanical nonlocality can be demonstrated by single-particle states. The validity of such a claim has been discussed in the literature, but without reaching a clear consensus. We show that the disagreement can be traced to what part of the total state of the experiment one assigns to the (macroscopic) measurement apparatus. However, with a conventional and legitimate interpretation of the measurement process one is led to the conclusion that even a single particle can show nonlocal properties.Comment: 6 pages, 5 figure

Thirty- and ninety-day outcomes after sublobar resection with and without brachytherapy for non–small cell lung cancer: Results from a multicenter phase III study

ObjectiveSublobar resection (SR) is commonly used for patients considered high risk for lobectomy. Nonoperative therapies are increasingly being reported for patients with similar risk because of perceived lower morbidity. We report 30- and 90-day adverse events (AEs) from American College of Surgeons Oncology Group Z4032, a multicenter phase III study for high-risk patients with stage I non–small cell lung cancer.MethodsData from 222 evaluable patients randomized to SR (n = 114) or SR with brachytherapy (n = 108) are reported. AEs were recorded using the Common Terminology Criteria for Adverse Events, Version 3.0, at 30 and 90 days after surgery. Risk factors (age, percent baseline carbon monoxide diffusion in the lung [DLCO%], percent forced expiratory volume in 1 second [FEV1%], upper lobe vs lower lobe resections, performance status, surgery approach, video-assisted thoracic surgery vs open and extent, and wedge vs segmentectomy) were analyzed using a multivariable logistic model for their impact on the incidence of grade 3 or higher (G3+) AEs. Respiratory AEs were also specifically analyzed.ResultsMedian age, FEV1%, and DLCO% were similar in the 2 treatment groups. There was no difference in the location of resection (upper vs lower lobe) or the use of segmental or wedge resections. There were no differences between the groups with respect to “respiratory” G3+ AEs (30 days: 14.9% vs 19.4%, P = .35; 0–90 days: 19.3% vs 25%, P = .31) and “any” G3+ AEs (30 days: 25.4% vs 30.6%, P = .37; 0–90 days: 29.8% vs 37%, P = .25). Further analysis combined the 2 groups. Mortality occurred in 3 patients (1.4%) by 30 days and in 6 patients (2.7%) by 90 days. Four of the 6 deaths were thought to be due to surgery. When considered as continuous variables, FEV1% was associated with “any” G3+ AE at days 0 to 30 (P = .03; odds ratio [OR] = 0.98) and days 0 to 90 (P = .05; OR = 0.98), and DLCO% was associated with “respiratory” G3+ AE at days 0 to 30 (P = .03; OR = 0.97) and days 0 to 90 (P = .05; OR = 0.98). Segmental resection was associated with a higher incidence of any G3+ AE compared with wedge resection at days 0 to 30 (40.3% vs 22.7%; OR = 2.56; P < .01) and days 0 to 90 (41.5% vs 29.7%; OR = 1.96; P = .04). The median FEV1% was 50%, and the median DLCO% was 46%. By using these median values as potential cutpoints, only a DLCO% of less than 46% was significantly associated with an increased risk of “respiratory” and “any” G3+ AE for days 0 to 30 and 0 to 90.ConclusionsIn a multicenter setting, SR with brachytherapy was not associated with increased morbidity compared with SR alone. SR/SR with brachytherapy can be performed safely in high-risk patients with non–small cell lung cancer with low 30- and 90-day mortality and acceptable morbidity. Segmental resection was associated with increased “any” G3+ AE, and DLCO% less than 46% was associated with “any” G3+ AE and “respiratory” G3+ AE at both 30 and 90 days

Direct measurement of optical quasidistribution functions: multimode theory and homodyne tests of Bell's inequalities

We develop a multimode theory of direct homodyne measurements of quantum optical quasidistribution functions. We demonstrate that unbalanced homodyning with appropriately shaped auxiliary coherent fields allows one to sample point-by-point different phase space representations of the electromagnetic field. Our analysis includes practical factors that are likely to affect the outcome of a realistic experiment, such as non-unit detection efficiency, imperfect mode matching, and dark counts. We apply the developed theory to discuss feasibility of observing a loophole-free violation of Bell's inequalities by measuring joint two-mode quasidistribution functions under locality conditions by photon counting. We determine the range of parameters of the experimental setup that enable violation of Bell's inequalities for two states exhibiting entanglement in the Fock basis: a one-photon Fock state divided by a 50:50 beam splitter, and a two-mode squeezed vacuum state produced in the process of non-degenerate parametric down-conversion.Comment: 18 pages, 7 figure

The First Magnetic Fields

We review current ideas on the origin of galactic and extragalactic magnetic fields. We begin by summarizing observations of magnetic fields at cosmological redshifts and on cosmological scales. These observations translate into constraints on the strength and scale magnetic fields must have during the early stages of galaxy formation in order to seed the galactic dynamo. We examine mechanisms for the generation of magnetic fields that operate prior during inflation and during subsequent phase transitions such as electroweak symmetry breaking and the quark-hadron phase transition. The implications of strong primordial magnetic fields for the reionization epoch as well as the first generation of stars is discussed in detail. The exotic, early-Universe mechanisms are contrasted with astrophysical processes that generate fields after recombination. For example, a Biermann-type battery can operate in a proto-galaxy during the early stages of structure formation. Moreover, magnetic fields in either an early generation of stars or active galactic nuclei can be dispersed into the intergalactic medium.Comment: Accepted for publication in Space Science Reviews. Pdf can be also downloaded from http://canopus.cnu.ac.kr/ryu/cosmic-mag1.pd

Measurement of qubits

We describe in detail the theory underpinning the measurement of density matrices of a pair of quantum two-level systems (qubits). Our particular emphasis is on qubits realized by the two polarization degrees of freedom of a pair of entangled photons generated in a down-conversion experiment; however, the discussion applies in general, regardless of the actual physical realization. Two techniques are discussed, namely, a tomographic reconstruction (in which the density matrix is linearly related to a set of measured quantities) and a maximum likelihood technique which requires numerical optimization (but has the advantage of producing density matrices that are always non-negative definite). In addition, a detailed error analysis is presented, allowing errors in quantities derived from the density matrix, such as the entropy or entanglement of formation, to be estimated. Examples based on down-conversion experiments are used to illustrate our results