Efficient γ-amino-proline-derived cell penetrating peptide-superparamagnetic iron oxide nanoparticle conjugates via aniline-catalyzed oxime chemistry as bimodal imaging nanoagents

Aniline-catalyzed oxime chemistry was employed to conjugate a γ-amino-proline-derived cell penetrating peptide to superparamagnetic iron oxide nanoparticles (SPIONs). Internalization of the novel nanoconjugate into HeLa cells was found to be remarkably higher compared to the analogous TAT-SPION conjugate.     

Rossinone-related meroterpenes from the Antarctic ascidian Aplidium fuegiense

The chemical analysis of the ascidian Aplidium fuegiense resulted in the isolation of three novel meroterpenoids 2–4, structurally related to the main co-occurring known rossinone B (1). The structures of the new compounds were determined by interpretation of spectroscopic data. Compounds 1–4 were found to be selectively localized in the viscera of the ascidian.     

Preparation of the Speech-LanguagePathologist Specializing in Voice: An Educational Survey

This study investigates the academic and clinical preparation a speech-language pathologist receives in the area of voice. The purpose is to determine how to structure continuing education and specialty training in vocology, defined as the science and practice of voice habilitation. Surveys were sent to the graduate programs in speech-language pathology accredited by the American Speech-Language-Hearing Association (ASHA) in 1994, and again in 1999. Results from the 1994 survey indicated that students received limited information and clinical experience in handling typical voice cases. Although most programs required a voice disorders course, fewer mandated coursework in normal voice production or clinical experience with voice patients. The follow-up survey showed that the educational environment in 1999 is similar to that in 1994. It is evident that the programs are in compliance with the Educational Training Board model developed by ASHA for basic clinical competence, but no structure for specialty training has yet emerged.     

Effect of Temperature on Shear‐Induced Anisotropic Structure in Polymer Clay Hydrogels

Summary: Shear‐induced orientation of nanoparticles in poly(ethylene oxide)/Laponite RD hydrogels has been investigated by small angle neutron scattering (SANS). As temperature is reduced, anisotropy develops at lower shear rates. The two‐correlation length Debye–Anderson–Brumberger (DAB) model provides a good fit to the experimental data. The deduced short‐range correlation length (≈5 nm) is observed to increase with shear. The long‐range correlation length (≈50 nm) shows a strong directional dependence, and decreases when shear is applied. The relative contribution of long‐range order to the SANS intensity is observed to increase with shear and decrease with temperature.

SANS anisotropy |(I_y − I_x)/(I_y + I_x)| as a function of shear rate and q at 2 °C.     

Computation Models for Parameterized Complexity

A parameterized computational problem is a set of pairs (x, k), where k is a distinguished item called “parameter”. FPT is the class of fixed-parameter tractable problems: for any fixed value of k, they are solvable in time bounded by a polynomial of degree α, where α is a constant not dependent on the parameter. In order to deal with parameterized intractability, Downey and Fellows have introduced a hierarchy of classes W[l] ? W[2] ? ? containing likely intractable parameterized problems, and they have shown that such classes have many natural, complete languages. In this paper we analyze several variations of the halting problem for nondeterministic Turing machines with parameterized time, and we show that its parameterized complexity strongly depends on some resources like the number of tapes, head and internal states, and on the size of the alphabet. Notice that classical polynomial-time complexity fails in distinguishing such features. As byproducts, we show that parameterized complexity is a useful tool for the study of the intrinsic power of some computational models, and we underline the different “computational powers” of some levels of the parameterized hierarchy.     

Straightforward α-carbamoylation of NADH-like dihydropyridines and enol ethers

The protonation of NADH-like dihydropyridines and cyclic enol ethers generates reactive cationic intermediates, which interact with isocyanides to afford α-carbamoylated heterocycles after an aqueous quenching, in Ugi and Passerini-type reactions, thus broadening the scope of these multicomponent processes.     

Rapid Quantification of 25-Hydroxyvitamin D<Subscript>3</Subscript> in Human Serum by Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry

LC-MS/MS is widely utilized today for quantification of vitamin D in biological fluids. Mass spectrometric assays for vitamin D require very careful method optimization for precise and interference-free, accurate analyses however. Here, we explore chemical derivatization and matrix-assisted laser desorption/ionization (MALDI) as a rapid alternative for quantitative measurement of 25-hydroxyvitamin D₃ in human serum, and compare it to results from LC-MS/MS. The method implemented an automated imaging step of each MALDI spot, to locate areas of high intensity, avoid sweet spot phenomena, and thus improve precision. There was no statistically significant difference in vitamin D quantification between the MALDI-MS/MS and LC-MS/MS: mean ± standard deviation for MALDI-MS—29.4?±?10.3 ng/mL—versus LC-MS/MS—30.3?±?11.2 ng/mL (P?=?0.128)—for the sum of the 25-hydroxyvitamin D epimers. The MALDI-based assay avoided time-consuming chromatographic separation steps and was thus much faster than the LC-MS/MS assay. It also consumed less sample, required no organic solvents, and was readily automated. In this proof-of-concept study, MALDI-MS readily demonstrated its potential for mass spectrometric quantification of vitamin D compounds in biological fluids.

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