Microfilm Research Articles

Architectural design of heterogeneous metallic nanocrystals--principles and processes.

CONSPECTUS: Heterogeneous metal nanocrystals (HMNCs) are a natural extension of simple metal nanocrystals (NCs), but as a research topic, they have been much less explored until recently. HMNCs are formed by integrating metal NCs of different compositions into a common entity, similar to the way atoms are bonded to form molecules. HMNCs can be built to exhibit an unprecedented architectural diversity and complexity by programming the arrangement of the NC building blocks ("unit NCs"). The architectural engineering of HMNCs involves the design and fabrication of the architecture-determining elements (ADEs), i.e., unit NCs with precise control of shape and size, and their relative positions in the design. Similar to molecular engineering, where structural diversity is used to create more property variations for application explorations, the architectural engineering of HMNCs can similarly increase the utility of metal NCs by offering a suite of properties to support multifunctionality in applications. The architectural engineering of HMNCs calls for processes and operations that can execute the design. Some enabling technologies already exist in the form of classical micro- and macroscale fabrication techniques, such as masking and etching. These processes, when used singly or in combination, are fully capable of fabricating nanoscopic objects. What is needed is a detailed understanding of the engineering control of ADEs and the translation of these principles into actual processes. For simplicity of execution, these processes should be integrated into a common reaction system and yet retain independence of control. The key to architectural diversity is therefore the independent controllability of each ADE in the design blueprint. The right chemical tools must be applied under the right circumstances in order to achieve the desired outcome. In this Account, after a short illustration of the infinite possibility of combining different ADEs to create HMNC design variations, we introduce the fabrication processes for each ADE, which enable shape, size, and location control of the unit NCs in a particular HMNC design. The principles of these processes are discussed and illustrated with examples. We then discuss how these processes may be integrated into a common reaction system while retaining the independence of individual processes. The principles for the independent control of each ADE are discussed in detail to lay the foundation for the selection of the chemical reaction system and its operating space.

Peculiar Role of the Metallic States on the Nano-MoS2Ceramic Particle Surface in Antimicrobial and Antifungal Activity

This study concerns the interactions of two chemically different materials hBN (covalent-ionic bonds) and MoS2 (covalent-ionic and dispersive bonds) with bacteria and fungi. The materials used in the study were in the form of micro- and nanocrystals. Countable inactivation of microorganisms (Staphylococcus aureus, Sarcina lutea, Aspergillus niger, Escherichia coli) took place only in the case of MoS2 nanosheets. The authors of the study suppose that the bioactivity of nano-MoS2 can be associated with the presence of “metallic states,” which are present only on their surface.

Potential Spark Erosion Approaches to Silicon Nanoparticles Production

This article demonstrates potential approaches to the production of Silicon Nanoparticles (SiNPs) using spark erosion in forms of Wire-EDM (WEDM), Die-sink and Micro -EDM. Utilizing the data from research work on such conventional spark erosion approaches, a novel method of nanoparticle production called high pressure flushing spark erosion has been introduced in this paper. This is an automated prototype machining system that utilizes deionized water sprayed @ 0.8 MPa through a rotating copper tool, boring on boron doped silicon ingot workpiece. SiNPs comprising an average diameter of 50nm were generated with approximate productivity of 1.5g/hr. The results demonstrate that the process holds excellent potential as an industrialized SiNPs preparation method in terms of size and productivity.

A Brief History of USNCB: Motivation and Formation

A Brief History of USNCB: Motivation and Formation

Sonochemically-induced spectral shift as a probe of green fluorescent protein release from nano capsules

Encapsulation in the form of micro and nanocapsules is an attractive route for controlling the delivery and release of active proteins and peptides. Many approaches exist to probe the morphology of such capsules as well as their mechanisms of formation. By contrast, the release of proteins from such components in a complex biological environment has been challenging to probe directly. In this paper we show that the spectral differences between green fluorescent protein (GFP) in capsules and in its free form can be used to monitor in situ the release of the protein from the confinement of capsules. These findings represent a new route towards engineering the spectral characteristics of GFP through physical rather than chemical means. We demonstrate the use of GFP protein capsules for monitoring in real time the release of protein in live cells by exposing rat L6 myotubes to protein capsules. The GFP spheres with a blue fluorescent signal dissociate inside the L6 myotubes to individual GFP molecules with a change in fluorescent signal from blue to green. These sensitive spectral characteristics enabled us to resolve the dissociation of capsules inside the cells in both time and space. We discuss the implications of our results for quantifying parameters crucial for the delivery of proteins in biological environments.

The effects of auxiliary electric field within the electrohydrodynamic atomization encapsulation chamber on particle size, morphology and collection efficiency

Electrohydrodynamic atomization (EHDA) or electrospray has been lately applied to fabricate drug carriers in the dosage forms of polymeric micro- and nano-fibers and particles. In the current study, EHDA process was performed in a glass encapsulation chamber to facilitate the formation of solid pharmaceutical particles after solvent evaporation from the electrosprayed droplets. High voltage nozzle and ring are enclosed in the named EHDA encapsulation chamber together with a grounded collecting plate. The unique feature of the design was an additional aluminum plate located a few centimeters above the collecting plate which was positively charged using a high voltage supplier. Furthermore, a simple finite-element model was generated to investigate the efficacies of flow and electric fields. This work aimed to investigate the effect of the auxiliary electric field on particle collection efficiency, morphology and size distribution. The final results show that application of the auxiliary electric field can clearly enhance particle collection efficiency in comparison to the EHDA process without auxiliary electric field. Additionally, it was established that the particle size distribution was not considerably influenced by the auxiliary electric field. On the contrary, the smoothness of the particles can be affected by the auxiliary electric field especially when a high voltage is applied to the flat plate.

MR Reprints: Two Excerpts from Microform Review

MR Reprints: Two Excerpts from Microform Review

Erratum: Excerpts from early issues of Microform Review

Erratum: Excerpts from early issues of Microform Review

Novel akermanite-based bioceramics from preceramic polymers and oxide fillers

Akermanite (Ca2MgSi2O7) ceramics have been successfully prepared by a novel approach, consisting of the heat treatment of silicone resins embedding MgO and CaO precursors, in the form of micro- and nano-sized particles, that act as reactive fillers. Phase purity was promoted by the use of nano-sized particles or by secondary additives, such as sodium borate. The use of hydroxyapatite as additional filler allowed the fabrication of monoliths with good specific mechanical properties, although with a complex phase assemblage. Sodium borate, besides favoring the crystallization of the desired silicate, promoted a substantial and homogeneous foaming of polymer/filler mixtures, leading to akermanite foams possessing good compressive strength.

A minimally skin incision for unilateral microform cleft lip repair

Objective To introduce a surgical procedure resulting in less scars for unilateral microform cleft lip.Methods A Z-plasty incision was designed at suffered agger nasi,and then subcutaneours dissection of suffered upper lip and basis nasi was performed.Releasing suffered alar nasi base from maxillary bone by partly severing the mesculus compressor naris,an orbicularis oculi flap was formed and fixed to the hypodermis of columella base for advancing to superior medial position and overlaying orbicularis oculi.The labial frenulum extension and vermillion submucoustissue flap plicature for filling incisura were carried out to correct the deformitiy of vermillion incisura.Results After 6-18 months follow-up,the wounds of 7 cases (aged 7-19 years) healed at the first grade.The deformity of unilateral subcutaneous celft lip,such as the agger nasi and vermillion incisura,widened nostril,and deficient abial height,was significantly improved.Conclusions Unilateral subcutaneous celft lip could be satisfactorily reconstructed by the surgical technique consisting of Z-plasty incision at agger nasi,orbicularis oculi flap advancing,labial frenulum extension and vermillion submucous tissue flap plicature,with less scar formation. Key words: Unilateral microform cleft lip; Minimally invasive surgery

Excerpts from early issues of Microform Review

Excerpts from early issues of Microform Review

Parma e la cultura ebraica Archivi da scoprire In occasione nel Giorno della Memoria 2013 (Parma, Archivio di Stato, 30 gennaio 2013)

Since 1987, the history of Jewish culture in Parma has found new sources, when some fragments of Medieval Hebrew manuscripts were discovered in the State Archive ( Archivio di Stato di Parma ). In 2011, after more than twenty years, thanks to the cooperation among the Archivio di Stato di Parma , the Israel National Library-Institute of Microfilmed Hebrew Manuscripts, the Italian Association of the Friends of the Hebrew University of Jerusalem and the Ambrosiana Library, new researche projects have been established. As an outcome of this collaboration, fragments of 54 manuscripts of Bible, Bible Commentaries, Midrash, Mishnah, Talmud, Halakhah and Liturgy have been examined. The result of these studies will be soon published.

Tuning size and magnetic thermal hysteresis in a new near room temperature spin crossover compound

A mononuclear spin crossover compound Fe(AP-Mesal)2, which exhibits spin transitions near room temperature and light induced excited spin state trapping (LIESST) effects at low temperature, was synthesized and substructured in the form of micro- and nanoscaled particles. A thermal hysteresis loop was detected with particle size reduction to microscale and nanoscale.

Analysis of Procedures for Correction of Microform Cleft Lip through Strategic Approaches

www.e-acfs.org pISSN 2287-1152 eISSN 2287-5603 16 Copyright © 2013 The Korean Cleft Palate-Craniofacial Association This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/ licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. 전략적 접근을 통한 미세형 구순열의 수술에서 실제 사용된 술기의 분석

English

Most industries are sited with little or no consideration for environmental and social consequences, especially in developing countries. This has led to the discharge of genotoxic chemicals used for many purposes in the manufacturing processes into environmental compartments such as air, water, soil and sediments. Results of the cytotoxic and genotoxic assays of these wastewaters on Allium cepa root tip meristem showed significant reduction of mitotic indices and diverse forms of chromosomal aberrations, cytokinetic failures, micro and multiple nuclei. In Nigeria, the results of diverse assessments of industrial effluents have shown that they are environmental risks and potential mutagenic agents, problems still exist in the enforcement of on ground sound legislative by Federal Ministry of Environment and Federal Environmental Protection Agency. Failure in implementation of sound policies has been identified to be caused by weakness and poor enforcement by the necessary arms of the government, public awareness of international, national and local environmental laws. Legislation and standards that apply to existing and proposed projects are grossly lacking, the absence of mandatory disclosure of information by industries hinders monitoring which is a major problem to compliance and enforcement. Furthermore, there is absence of a legal framework which would ensure that industries comply with the requirement of standing environmental legislation. Any development that does not respect the environment cannot be said to be sustainable. There is therefore the need to integrate the environmental legislatives and environmental impact assessment (EIA) reports in the establishment and consequent monitoring of industries and industrial activities for the establishment and promotion of sustainable development and sound technologies.   Key words: Genotoxic, Allium test, industry, legislation, wastewater.

The Influence of Stational Factors over Indicator Species

In this paper, the direct links between the herbaceous vegetation and soil pH has beenanalyzed, also taking in consideration other stational elements. For a more relevant result, the studywas conducted in a secular forest because the natural balance and processes are way superior to theones of a small planted forest. In order to achieve the proposed objectives, 136 circular samplesurfaces, with a radius of 12,62 m, were created after a grid reference, 50 m apart, on the entire 35B,LIP VIII, SlAƒtioara, Stulpicani forestry, Forestry Department Suceava, landscape surface. Otherwise,on this surface, the bonds between the information provided by the indicator species and soil pH,altitude and climate factors are not the usual ones. They are the ones from the North East side of thestudied terrain, on a cone shaped micro-form of landscape where according to the relative low altitudethe reactions should have been registered as having a more reduced acid pH. An importantphenomenon that was observed in this place is cavitation. The influences of the phenomenons such ascavitation must be studied more extensive in the future, because they could have a direct effect,unknown yet, over the local vegetation.

Thermal Polymerization of Styrene, Part 1 – Bulk Polymerization

AbstractThe thermal bulk polymerization of styrene is critically reviewed. There is still no generally accepted kinetic model for the thermal radical formation process, but ideal second‐ or third‐order models are widely used for modeling bulk systems. Since initiation and chain transfer reactions cannot be treated independently from one another as long as the same species is considered to be involved, it is concluded that non‐ideal kinetics, possibly in form of a (micro‐)viscosity dependency of the Mayo mechanism, are likely to be present. A mathematical model is presented that keeps the predictive capabilities of the Hui‐Hamielec model, but allows facile implementation of reaction specific modifications. Part 2 of this paper will focus on the effect of compartmentalization on the thermal polymerization of styrene. magnified image

Superfinishing polish of diamond substrates for epitaxial technology

The regimes of superfinishing vibropolish of single-crystal synthetic diamond substrates have been optimized. It has been established that after polishing for 100 h the surface roughness was 0.43 nm. A method for controlling the structural perfection of the near-surface layers of diamond substrates upon their grinding and polishing has been proposed and substantiated. X-ray diffraction studies point to the possibility of using the given method in selecting suitable substrates for the technology of growing diamond films in micro- and nanoelectronics.

Mitochondria-targeted ubiquinone (MitoQ) decreases ethanol-dependent micro and macro hepatosteatosis

Chronic alcohol-induced liver disease results in inflammation, steatosis, and increased oxidative and nitrosative damage to the mitochondrion. We hypothesized that targeting an antioxidant to the mitochondria would prevent oxidative damage and attenuate the steatosis associated with alcoholic liver disease. To test this we investigated the effects of mitochondria-targeted ubiquinone (MitoQ) (5 and 25 mg/kg/day for 4 weeks) in male Sprague-Dawley rats consuming ethanol using the Lieber-DeCarli diet with pair-fed controls. Hepatic steatosis, 3-nitrotyrosine (3-NT), 4-hydroxynonenal (4-HNE), hypoxia inducible factor α (HIF1α), and the activity of the mitochondrial respiratory chain complexes were assessed. As reported previously, ethanol consumption resulted in hepatocyte ballooning, increased lipid accumulation in the form of micro and macrovesicular steatosis, and induction of cytochrome P450 2E1 (CYP2E1). MitoQ had a minor effect on the ethanol-dependent decrease in mitochondrial respiratory chain proteins and their activities; however, it did decrease hepatic steatosis in ethanol-consuming animals and prevented the ethanol-induced formation of 3-NT and 4-HNE. Interestingly, MitoQ completely blocked the increase in HIF1α in all ethanol-fed groups, which has previously been demonstrated in cell culture models and shown to be essential in ethanol-dependent hepatosteatosis. These results demonstrate the antioxidant capacity of MitoQ in alleviating alcohol-associated mitochondrial reactive oxygen species (ROS) and several downstream effects of ROS/RNS (reactive nitrogen species) production such as inhibiting protein nitration and protein aldehyde formation and specifically ROS-dependent HIF1α stabilization.

DSETHVASAN: A NOVEL NANODRUG AGAINST SLEEPING SICKNESS

Sleeping sickness (causal agent, Trypanosoma sp. parasite) causes huge morbidity and mortality in Africa (both human and livestock) in particular and zoo animals worldwide. Three of the four currently approved drugs (Pentamidine, Melarsoprol, Eflornithine, and Nifurtimox) were developed over 50 years ago. Current therapies are unsatisfactory due to unacceptable level of side effects. Pentamidine, an aromatic diamidine, safest so far, inhibits mitochondrial enzymes. Furthermore, it is effective only in early stages of infections and not on the later stage. Melarsoprol, practically insoluble in water, is very toxic and it is given intravenously (i.v.) for later stage infections only. Other drugs like eflornithine and nitfurtimox are also unsatisfactory for various reasons. Human serum derived high-density lipoprotein (HDL; not mouse or any other mammalian HDL) shows trypanolytic effect in vitro and in vivo on T. brucei. But the mechanism of action of human HDL is far from clear. In the absence of novel drug leads, nanodrugs might be valid options as nanoparticles show better accessibility to cells, supramolecular interactions due to enormous increase in surface area to volume ratio, altered partition coefficient, etc. Surface-modified hydrophobic microsilica (FS), mixture of micro- and nanosilica (Dsethvasan) and nanosilica (AL) were characterized by UV–Vis, DLS, SEM, EDAX, AFM, and XRD. Trypanosoma evansi collected from infected horses were injected in mice. Control infected mouse (n = 30) showed 100% mortality within 72±24 h of injection. Dsethvasan-treated mice (n = 30) survived for 192±24 h. FS-treated mice (n = 30) survived for 120±24 h but the AL-treated mice (n = 30) died within 72±24 h of inoculation like infected control. Hydrophobic Dsethvasan which consists of pure amorphous forms of micro- and nanosilica works better than FS (AL is not at all effective). Therefore, micro- and nanomixture of amorphous silica is best suited for treating Trypanosoma infection in mice. The possible role of ratio of higher to lower size class has been discussed.