Quantitation of Acyclovir in Pharmaceutical Dosage forms using High-Performance Liquid Chromatography

A stability-indicating high performance liquid chromatography method for the quantitation of acyclovir in pharmaceutical dosage forms (capsules, ointment and injection) has been developed. The method is accurate and precise with a percent relative standard deviation of 1.2 based on 5 readings. The excipients present in the dosage forms did not interfere with the assay method. The recovery from the synthetic mixtures was quantitative. The samples decomposed under drastic conditions showed a new peak in the chromatogram. Acyclovir appears to be more stable in the alkaline than in the acidic solution. There appears to be a distribution/decomposition problem with the ointment sample being marketed in certain types of tubes used previously and still on the market.     

An overview of 3D object grasp synthesis algorithms

This overview presents computational algorithms for generating 3D object grasps with autonomous multi-fingered robotic hands. Robotic grasping has been an active research subject for decades, and a great deal of effort has been spent on grasp synthesis algorithms. Existing papers focus on reviewing the mechanics of grasping and the finger–object contact interactions Bicchi and Kumar (2000) [12] or robot hand design and their control Al-Gallaf et al. (1993) [70]. Robot grasp synthesis algorithms have been reviewed in Shimoga (1996) [71], but since then an important progress has been made toward applying learning techniques to the grasping problem. This overview focuses on analytical as well as empirical grasp synthesis approaches.     

Decentralized control of a group of mobile robots for deployment in sweep coverage

This paper addresses a problem of sweep coverage by deploying a network of autonomous mobile robots. We propose a decentralized control algorithm for the robots to accomplish the sweep coverage. The sweep coverage is achieved by coordinating the robots to move along a given path that is unknown to the vehicles a priori. The motion coordination algorithm is developed based on simple consensus algorithms. The effectiveness of the algorithm is demonstrated via numerical simulations. The proposed algorithm would have applications to military and civilian operations.     

Extreme-value-theoretic estimation of local intrinsic dimensionality

This paper is concerned with the estimation of a local measure of intrinsic dimensionality (ID) recently proposed by Houle. The local model can be regarded as an extension of Karger and Ruhl’s expansion dimension to a statistical setting in which the distribution of distances to a query point is modeled in terms of a continuous random variable. This form of intrinsic dimensionality can be particularly useful in search, classification, outlier detection, and other contexts in machine learning, databases, and data mining, as it has been shown to be equivalent to a measure of the discriminative power of similarity functions. Several estimators of local ID are proposed and analyzed based on extreme value theory, using maximum likelihood estimation, the method of moments, probability weighted moments, and regularly varying functions. An experimental evaluation is also provided, using both real and artificial data.     

Direct conversion of highly aromatic phthalonitrile thermosetting resins into carbon nanotube containing solids

A method for the in situ synthesis of multi-walled carbon nanotubes in a bulk solid composition from the pyrolysis of a mixture formulated from Co₂(CO)₈ and various high temperature phthalonitrile resins is presented. Carbon nanotube containing compositions in various forms (solid, fiber, and film) can be readily fabricated by this method utilizing slight modifications to the standard resin processing techniques. The formation of carbon nanotubes occurs during the carbonization process at ambient pressure. X-ray diffraction, scanning electron microscopy, and transmission electron microscopy studies show the presence of a copious amount of multi-walled carbon nanotubes in the carbonaceous composition.     

Solid-phase synthesis of multi-walled carbon nanotubes from butadiynyl-ferrocene-containing compounds

Multi-walled carbon nanotubes (MWCNTs) have been synthesized from novel butadiynyl-ferrocene-containing compounds. The formation of the MWCNTs occurs in the solid phase at ambient pressure in a typical high-temperature furnace. Heat treatment of the various compounds to temperatures up to 1300 °C under atmospheric pressure resulted in the decomposition of the ferrocene units and the formation of Fe nanoparticles in the polymeric-to-carbon nanoparticle-to-carbon nanotube compositions. The Fe atoms, clusters, and/or nanoparticles are the key to the formation of the carbon nanotubes. X-ray diffraction, scanning electron microscopy, and transmission electron microscopy studies show the presence of a large quantity of MWCNTs in the carbonaceous solid residue.     

Patient-Derived Tumor Organoids for Guidance of Personalized Drug Therapies in Recurrent Glioblastoma

An obstacle to effective uniform treatment of glioblastoma, especially at recurrence, is genetic and cellular intertumoral heterogeneity. Hence, personalized strategies are necessary, as are means to stratify potential targeted therapies in a clinically relevant timeframe. Functional profiling of drug candidates against patient-derived glioblastoma organoids (PD-GBO) holds promise as an empirical method to preclinically discover potentially effective treatments of individual tumors. Here, we describe our establishment of a PD-GBO-based functional profiling platform and the results of its application to four patient tumors. We show that our PD-GBO model system preserves key features of individual patient glioblastomas in vivo. As proof of concept, we tested a panel of 41 FDA-approved drugs and were able to identify potential treatment options for three out of four patients; the turnaround from tumor resection to discovery of treatment option was 13, 14, and 15 days, respectively. These results demonstrate that this approach is a complement and, potentially, an alternative to current molecular profiling efforts in the pursuit of effective personalized treatment discovery in a clinically relevant time period. Furthermore, these results warrant the use of PD-GBO platforms for preclinical identification of new drugs against defined morphological glioblastoma features.     

Phase-pure two-dimensional FexGeTe2 magnets with near-room-temperature Tc

Two-dimensional(2D)ferromagnets with out-of-plane(OOP)magnetic anisotropy are potential candidates for realizing the next-generation memory devices with ultra-low power consumption and high storage density.However,a scalable approach to synthesize 2D magnets with OOP anisotropy directly on the complimentary metal-oxide semiconductor(CMOS)compatible substrates has not yet been mainly explored,which hinders the practical application of 2D magnets.This work demonstrates a cascaded space confined chemical vapor deposition(CS-CVD)technique to synthesize 2D FexGeTe₂ ferromagnets.The weight fraction of iron(Fe)in the precursor controls the phase purity of the as-grown FexGeTe2.As a result,high-quality Fe₃GeTe₂ and Fe₅GeTe₂ flakes have been grown selectively using the CS-CVD technique.Curie temperature(Tc)of the as-grown FexGeTe2 can be up to-280 K,nearly room temperature.The thickness and temperature-dependent magnetic studies on the Fe₅GeTe₂ reveal a 2D Ising to 3D XY behavior.Also,Terahertz spectroscopy experiments on Fe₅GeTe₂ display the highest conductivity among other FexGeTe₂ 2D magnets.The results of this work indicate a scalable pathway for the direct growth and integration of 2D ternary magnets on CMOS-based substrates to develop spintronic memory devices.     

The need for continuing education in ethics as reported by rural and urban mental health care providers.

Continuing professional education (CPE) sponsors planning events for mental health care licensees can assure better attendance if they can successfully address the needs of their target audience. Offering topics of interest is particularly crucial when CPE events need to draw large numbers of attendees to be financially viable. A survey of nearly 400 health licensees regarding CPE needs, especially as related to ethics, revealed that the greatest interest in such CPE was reported by master's-level mental health care providers. Topic areas with the greatest draw were the management of clients who present with special issues (e.g., substance abuse, medical illness, or cultural diversity) and competent management of colleague misconduct and impairment, rather than more traditional ethics issues. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Ionic-Liquid Induced Morphology Tuning of PEDOT:PSS for High-Performance Organic Electrochemical Transistors

The ability to operate in aqueous environments makes poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate), PEDOT:PSS, based organic electrochemical transistors (OECTs) excellent candidates for a variety of biological applications. Current research in PEDOT:PSS based OECTs is primarily focused on improving the conductivity of PEDOT:PSS film to achieve high transconductance (g_m). The improved conductivity and electronic transport are attributed to the formation of enlarged PEDOT-rich domains and shorter PEDOT stacking, but such a change in morphology sacrifices the ionic transport and, therefore, the doping/de-doping process. Additionally, little is known about the effect of such morphology changes on the gate bias that makes the maximum g_m ($V_G^{Peak}$), threshold voltage (V_T), and transient behavior of PEDOT:PSS based OECTs. Here, the molecular packing and nanostructure of PEDOT:PSS films are tuned using ionic liquids as additives, namely, 1-Ethyl-3-methylimidazolium (EMIM) as cation and anions of chloride (Cl), trifluoromethanesulfonate (OTF), bis(trifluoromethylsulfonyl)imide (TFSI), and tricyanomethanide (TCM). It is demonstrated that an optimal morphology is realized using EMIM OTF ionic liquids that generate smaller fibril-like PEDOT-rich domains with relatively loose structures. Such optimal morphology improves ion accessibility, lowering the gate bias required to completely de-dope the channel, and thus enabling to achieve high transconductance, fast transient response, and at lower gate bias window simultaneously.