Application of terpyridyl ligands to tune the optical and electrochemical properties of a conducting polymer

We present a simple and effective way of using metal and metal–ligand modifications to tune the electrochemical and optical properties of conducting polymers. To that end, a polyterthiophene functionalized with terpyridine moieties was synthesized and then the resulting film''s surface or bulk was modified with different metal ions, namely Fe²⁺, Zn²⁺ and Cu²⁺ and terpyridine. The modification of the terpyridine functionalized polyterthiophene film by Fe²⁺ increased the absorptivity and electrochemical capacitance of the conducting polymer, and improved its conjugation. Further modification by Zn²⁺ and Cu²⁺ resulted in dramatically different spectroelectrochemical properties of the film. Moreover, the influence of the solvents (ACN and 1 : 1 ACN : H₂O) in conjunction with the metal ion applied for the modification was found crucial for the electrochemical and optical properties of the films.

We present a simple and effective way of using metal and metal–ligand modifications to tune the electrochemical and optical properties of conducting polymers.     

Tunable porous silica nanoparticles as a universal dye adsorbent

Here, we report selective adsorption of cationic dyes methylene blue (MB) and rhodamine B (RB) and anionic dyes methyl orange (MO) and bromo cresol green (BCG) by modifying the surface of cetyl trimethyl ammonium bromide (CTAB) coated porous silica nanoparticles (PSN). We used a top down approach to synthesize PSN (porous silica nanoparticles) without high temperature calcination. X-ray diffraction study confirms the formation of pure phase silica nanoparticles. SEM analysis reveals that the particle morphology is spherical and the size range lies in-between 150–200 nm. We have studied the dye adsorption properties for three cases of PSN at varying calcination temperatures of 100 °C, 250 °C and 500 °C, respectively. Thermal study has been performed in the temperature range of 50–800 °C to check the calcination temperature. In this report, we have tuned the surface properties for selective adsorption of cationic and anionic dyes in water. In the first case, 100 °C calcined PSN selectively adsorb only anionic dyes, whereas in the second case, 500 °C calcined PSN adsorb only cationic dyes and finally, an optimized calcination temperature ≈250 °C could be used for all types of dye to be adsorbed irrespective of charges on the dyes. The mode of interaction of dyes with PSN has been explained with a proper mechanism in all three cases. The adsorptions of dyes are confirmed by UV-Vis spectroscopy. Adsorption capacity and regenerable performance of adsorbents have also been studied.

Adsorption of cationic and anionic dyes (A) MO, (B) BCG, (C) RB, and (D) MB by optimized calcined porous silica nanoparticles.     

Fluorescence microspectroscopy as a tool to study mechanism of nanoparticles delivery into living cancer cells

Lack of better understanding of nanoparticles targeted delivery into cancer cells calls for advanced optical microscopy methodologies. Here we present a development of fluorescence microspectroscopy (spectral imaging) based on a white light spinning disk confocal microscope with emission wavelength selection by a liquid crystal tunable filter. Spectral contrasting of images was used to localize polymer nanoparticles and cell membranes labeled with fluorophores that have substantially overlapping spectra. In addition, fluorescence microspectroscopy enabled spatially-resolved detection of small but significant effects of local molecular environment on the properties of environment-sensitive fluorescent probe. The observed spectral shift suggests that the delivery of suitably composed cancerostatic alkylphospholipid nanoparticles into living cancer cells might rely on the fusion with plasma cell membrane.     

Determination of berberine hydrochloride using a fluorimetric method with silica nanoparticles as a probe

The interaction of silica nanoparticles (SiO₂NPs) with berberine hydrochloride (BRH) was studied in aqueous solution at pH 9.0 and room temperature by using fluorophotometry. Based on a significant enhancement of the fluorescence intensity of the SiO₂NPs–BRH aggregates, a spectrofluorimetric method which was simple, sensitive and green was developed for the determination of BRH in aqueous solution. The linear range of the method was from 2.0–50.0 μg L⁻¹ with a detection limit of 0.73 μg L⁻¹. There was no interference from the compounds normally used to formulate pharmaceutical tablets. The proposed method was applied to the determination of BRH in tablets with satisfactory results and good consistency with the results obtained by standard methods.

A simple, green and sensitive spectrofluorimetric method was proposed for the determination of berberine hydrochloride (BRH) in aqueous solution.     

Cetyltrimethylammonium chloride-loaded mesoporous silica nanoparticles as a mitochondrion-targeting agent for tumor therapy

Mitochondria play an important role in supplying cellular energy, cell signaling and governing cell death. In addition, mitochondria have also been proved to be essential for tumor generation and development. Thus, mitochondrion-targeting therapeutics and treatments have emerged as promising strategies against cancer. However, the lack of mitochondrion-targeting agents has limited their application. To this end, we report cetyltrimethylammonium chloride-loaded mesoporous silica nanoparticles conjugated with human serum albumin (CTAC@MSNs-HSA) as a mitochondrion-targeting agent for anticancer treatment. As the structure-directing agent in the synthesis of MSNs, CTAC is stored within MSNs. Due to their desirable size and HSA receptor-mediated transcytosis, CTAC@MSNs-HSA show great cellular uptake and enhanced accumulation in the cytoplasm. Positively charged CTAC could actively target mitochondria by interacting with the negatively charged mitochondria membrane, and then lead to the dysfunction of mitochondria by decreasing mitochondrial potential and intracellular ATP levels, resulting in the necrosis and apoptosis of MCF-7 cells. Therefore, significant antitumor activity is observed by in vitro studies. Moreover, in vivo studies confirm that the CTAC@MSNs-HSA are able to induce cancer cell death and efficiently inhibit tumor growth. These results demonstrate the potential of CTAC@MSNs-HSA in cancer therapeutics as well as providing insights into mitochondrion-targeting treatment.

CTAC@MSNs-HSA lead to the dysfunction of mitochondria, resulting in the necrosis and apoptosis of cancer cells.     

2-D organization of silica nanoparticles on gold surfaces: CO2 marker detection and storage

A single layer of silica nanoparticles with an average size of ∼200 nm was deposited over the surface of pristine gold wafers, aided by (3-mercaptopropyl)trimethoxysilane. The nanoparticle immobilization was driven by covalent bonding rather than a self-assembly process, leading to a cluster-assembled material which has CO₂ sensing features. Here, we show how this device can be used for CO₂ physisorption and chemisorption. We analyse the device, both spectroscopically and morphologically, before and after exposure to an atmosphere of 7 mbar of CO₂, inside a planetary atmospheres and surfaces simulation chamber, (PASC) mimiking Martian atmospheric conditions. Our studies demonstrate that these clusters are suitable for CO₂ detection and storage, under well controlled experimental Martian conditions. Their high sensitivity at a very low concentration of CO₂, 12.4 ppm, makes them ideal candidates in the nanosensor field.

A single layer of silica nanoparticles with an average size of ∼200 nm was deposited over the surface of pristine gold wafers, aided by (3-mercaptopropyl)trimethoxysilane.     

Uniform mesoporous silica coated iron oxide nanoparticles as a highly efficient,nontoxic MRI T2 contrast agent with tunable proton relaxivities

Monodisperse mesoporous silica (mSiO₂) coated superparamagnetic iron oxide (Fe₃O₄@mSiO₂) nanoparticles (NPs) have been developed as a potential magnetic resonance imaging (MRI) T₂ contrast agent. To evaluate the effect of surface coating on MRI contrast efficiency, we examined the proton relaxivities of Fe₃O₄@mSiO₂ NPs with different coating thicknesses. It was found that the mSiO₂ coating has a significant impact on the efficiency of Fe₃O₄ NPs for MRI contrast enhancement. The efficiency increases with the thickness of mSiO₂ coating and is much higher than that of the commercial contrast agents. Nuclear magnetic resonance (NMR) relaxometry of Fe₃O₄@mSiO₂ further revealed that mSiO₂ coating is partially permeable to water molecules and therefore induces the decrease of longitudinal relaxivity, r₁. Biocompatibility evaluation of various sized (ca. 35–95 nm) Fe₃O₄@mSiO₂ NPs was tested on OC‐k3 cells and the result showed that these particles have no negative impact on cell viability. The enhanced MRI efficiency of Fe₃O₄@mSiO₂ highlights these core–shell particles as highly efficient T₂ contrast agents with high biocompatibility. Copyright © 2012 John Wiley & Sons, Ltd.     

Lung ultrasound as a tool to guide respiratory physiotherapy

Lung ultrasound (LUS) is becoming an invaluable tool in the management of critically ill patients. We report two cases showing the importance of LUS as a guide to optimize respiratory physiotherapy in the intensive care unit, allowing a successful lung donation process and to redirect the physiotherapist's approach. The use of LUS requires an adequate training but it is becoming an important tool in management algorithms for critically ill patients.     

Fe2O3 and Gd2O3 nanoparticles loaded in mesoporous silica: insights into influence of NPs concentration and silica dimensionality

Fine Fe₂O₃ and Gd₂O₃ magnetic nanoparticles (NPs) with sizes 7 nm and 10 nm embedded into mesoporous silica have been prepared using a wet-impregnation method. A comparative study of the reactant concentration along with the hosting matrix symmetry on mesostructuring and the magnetic properties of the nanocomposites have been investigated. Reactants with four different concentrations of Fe³⁺ and Gd³⁺ ions and silica matrices with two different kinds of symmetry (hexagonal and cubic) have been utilized for the study. The structural characterization of the samples has been carried out by the N₂ adsorption/desorption method, high-energy X-ray diffraction (HE-XRD), TG/DTA, and high resolution transmission electron microscopy (HRTEM). The magnetic properties of the nanocomposites have been examined by means of SQUID magnetometry. It has been found that a range of different magnetic states (diamagnetic, paramagnetic, ferromagnetic, superparamagnetic) can be induced by the feasible tailoring of the particle concentration, the porous matrix symmetry and the composition. Furthermore, the existence of a “critical concentration limit” for embedding the particles within the body of the matrix has been confirmed. Exceeding the limit results in the expulsion of nanoparticles on the outer surface of the mesoporous matrix. Revelation of the relationships between particle concentration, matrix symmetry and magnetic properties of the particular composite reported in this study may facilitate the design and construction of advanced intelligent nanodevices.

The concentration of nanoparticles inside the pores and the symmetry of the porous matrix significantly affected the magnetic properties.     

Structure and characterisation of hydroxyethylcellulose–silica nanoparticles

Functionalising nanoparticles with polymers has gained much interest in recent years, as it aids colloidal stability and manipulation of surface properties. Here, polymer-coated thiolated silica nanoparticles were synthesised by self-condensation of 3-mercaptopropyltrimethoxysilane in the presence of hydroxyethylcellulose. These nanoparticles were characterised by dynamic light scattering, small angle neutron scattering, Nanoparticle Tracking Analysis, Raman spectroscopy, FT-IR spectroscopy, thermogravimetric analysis, Ellman''s assay, transmission electron microscopy and cryo-transmission electron microscopy. It was found that increasing the amount of hydroxyethylcellulose in the reaction mixture increased the nanoparticle size and reduced the number of thiol groups on their surface. Additionally, by utilising small angle neutron scattering and dynamic light scattering, it was demonstrated that higher concentrations of polymer in the reaction mixture (0.5–2% w/v) resulted in the formation of aggregates, whereby several silica nanoparticles are bridged together with macromolecules of hydroxyethylcellulose. A correlation was identified between the aggregate size and number of particles per aggregate based on size discrepancies observed between DLS and SANS measurements. This information makes it possible to control the size of aggregates during a simple one-pot synthesis; a prospect highly desirable in the design of potential drug delivery systems.

Polymer-coated thiolated silica nanoparticles were synthesised by self-condensation of 3-mercaptopropyltrimethoxysilane in the presence of hydroxyethylcellulose.     

Bedside waveforms interpretation as a tool to identify patient-ventilator asynchronies

Objective During assisted modes of ventilatory support the ventilatory output is the final expression of the interaction between the ventilator and the patients controller of breathing. This interaction may lead to patient-ventilator asynchrony, preventing the ventilator from achieving its goals, and may cause patient harm. Flow, volume, and airway pressure signals are significantly affected by patient-ventilator interaction and may serve as a tool to guide the physician to take the appropriate action to improve the synchrony between patient and ventilator. This review discusses the basic waveforms during assisted mechanical ventilation and how their interpretation may influence the management of ventilated patients. The discussion is limited on waveform eye interpretation of the signals without using any intervention which may interrupt the process of mechanical ventilation.Discussion Flow, volume, and airway pressure may be used to (a) identify the mode of ventilator assistance, triggering delay, ineffective efforts, and autotriggering, (b) estimate qualitatively patients respiratory efforts, and (c) recognize delayed and premature opening of exhalation valve. These signals may also serve as a tool for gross estimation of respiratory system mechanics and monitor the effects of disease progression and various therapeutic interventions.Conclusions Flow, volume, and airway pressure waveforms are valuable real-time tools in identifying various aspects of patient-ventilator interactionElectronic Supplementary Material Electronic supplementary material to this paper can be obtained by using the Springer Link server located at     

Decision analysis as a tool to support an analytical pattern-of-reasoning

Abstract Decision analysis is offered as a tool to aid nurses' decision-making in complex and troublesome situations where there are mutually exclusive actions and time is available for deliberation. Decision analysis can be formal or informal. Formal decision analysis provides a structure for representing the decision situation and a mathematical procedure for prescribing the alternative action that is most consistent with what is known and what one values. Informal decision analysis uses the concepts and sometimes the structure of decision analysis, but usually does not include the mathematical calculations. In the present paper, the authors illustrate how formal and informal decision analysis might be used by nurses to: (i) enhance their own decision-making; (ii) assist patients or family caregivers with decision-making and; (iii) promote informed health care policy development. Finally, the advantages and limitations of decision analysis are discussed.     

Lipidomics as a tool of predicting progression from non-alcoholic fatty pancreas disease to type 2 diabetes mellitus

The lipid metabolism relationship between non-alcoholic fatty pancreas disease (NAFPD) and type 2 diabetes mellitus (T2DM) is poorly defined. We aim to identify novel T2DM-related lipid biomarkers in addition to previous studies and provide the evidence for elucidating the relationship between NAFPD and T2DM in a lipid perspective. In this study, multi-dimensional mass spectrometry-based shotgun lipidomics (MDMS-SL) was used to investigate the potential discriminating lipid profile of the fasting plasma of 105 Chinese individuals (39 NAFPD patients, 38 T2DM patients and 30 healthy controls). Then multivariate statistical analysis combined with pathway analysis was performed to identify the lipid biomarker and explore the potential relationship of these two important diseases. The results described a marked reduction of plasmalogen and a significant 4-hydroxynonenal increase in the two diagnostic group, which indicated increased oxidative stress and peroxisomal dysfunction in patients. 60 discriminating metabolites were identified by multivariate statistical analysis of the lipidomics data. In addition, ingenuity pathway analysis (IPA) and a metabolic network constructed by prediction of IPA indicated that lipid metabolism, molecular transport, carbohydrate metabolism and small molecule biochemistry were correlated with disease progression. Our results revealed that the profile of plasma lipid alteration characteristic of NAFPD was similar to that of T2DM, especially during the period prior to the onset of T2DM.

There are three subclasses of PC (phosphatidylcholine, dPC; pPC; and plasmanylcholine, aPC). Several species of pPC decreased significantly in NDM and DM patients and especially in DM patients, while dPC and aPC showed no significant change.     

Synthesis of size-controlled and highly monodispersed silica nanoparticles using a short alkyl-chain fluorinated surfactant

Highly monodispersed silica nanoparticles (SiNPs) were synthesised using a fluorinated surfactant, HOCH₂CH(CF₃)CO₂H, and its efficiency was compared with efficiencies of five other surfactants. The size of the SiNPs (∼50–200 nm) was controlled by controlling the surfactant amount. The short alkyl-chain fluoro surfactant was found to be more efficient at producing monodispersed SiNPs than its long alkyl-chain fluoro or non-fluorinated surfactant counterparts.

Shape, size, and morphology controlled synthesis of monodispersed silica nanoparticles using 3-hydroxy-2-(trifluoromethyl)-propanoic acid (MAF-OH) surfactant.