Two-Photon Fluorescence Lysosomal Bioimaging with a Micelle-Encapsulated Fluorescent Probe

We report two-photon fluorescence microscopy (2PFM) imaging and in vitro cell viability of a new, efficient, lysosome-selective system based on a two-photon absorbing (2PA) fluorescent probe (I) encapsulated in Pluronic® F-127 micelles. Preparation of dye I was accomplished via microwave-assisted synthesis, resulting in improved yields and reduced reaction times. Photophysical characterization revealed notable 2PA efficiency of this probe.     

Experimental Investigation of the 2D Ion Beam Profile Generated by an ESI Octopole-QMS System

In this paper, we have employed an ion imaging approach to investigate the behavior of ions exiting from a quadrupole mass spectrometer (QMS) system that employs a radio frequency octopole ion guide before the QMS. An in-vacuum active pixel detector (Timepix) is employed at the exit of the QMS to image the ion patterns. The detector assembly simultaneously records the ion impact position and number of ions per pixel in every measurement frame. The transmission characteristics of the ion beam exiting the QMS are studied using this imaging detector under different operating conditions. Experimental results confirm that the ion spatial distribution exiting the QMS is heavily influenced by ion injection conditions. Furthermore, ion images from Timepix measurements of protein standards demonstrate the capability to enhance the quality of the mass spectral information and provide a detailed insight in the spatial distribution of different charge states (and hence different m/z) ions exiting the QMS.      

Effects of oxygen doping on properties of microcrystalline silicon film grown using rapid thermal chemical vapor deposition

An oxygen doped microcrystalline silicon (μc-Si) deposition process is developed by mixing small amounts of nitrous oxide (N₂O) with silane (SiH₄) in a rapid thermal chemical vapor deposition (RTCVD) reactor. The effects of oxygen doping on the properties of RTCVD μc-Si films are studied. Experimental results show that the RTCVD process provides high deposition rates for μc-Si and polycrystalline silicon (polySi) films at elevated deposition temperatures and pressures. The surface roughness of the RTCVD μc-Si films can be significantly reduced compared to that of conventional LPCVD polySi films. Steep side walls can be realized due to the small grain size of the μc-Si films. The sheet resistance of BF₂ doped μc-Si films is slightly higher than that of BF₂ doped polySi films, whereas sheet resistances of P and As doped μc-Si films are much higher than those of the corresponding P and As doped polySi films. Measurements of the catastrophic breakdown strength of metal-oxide-semiconductor (MOS) capacitors indicate that the quality of gate electrodes fabricated using μc-Si is improved relative to that of MOS capacitors fabricated using polySi gate electrodes.     

Speciation of volatile antimony compounds in culture headspace gases of Cryptococcus humicolus using solid phase microextraction and gas chromatography–mass spectrometry

Direct analysis of the volatile antimony compounds stibine (SbH₃), monomethylantimony, dimethylantimony (Me₂Sb) and trimethylantimony (Me₃Sb) using solid phase microextraction (SPME) with polydimethylsiloxane fibres and gas chromatography–mass spectrometry (GC–MS) is described. The best analyte to background signal ratio was achieved using a 20 min extraction time. Antimony species were separated using a 3% phenylmethylsilicone capillary column operated at a column pressure of 70 kPa, a flow rate of 1.4 ml min^?1 and temperature ramping from 30 to 36 °C at 0.1 °C min^?1. Cryogenic focusing of desorbed species was required to achieve resolution of antimony species. The optimized SPME–GC–MS method was applied to the analysis of headspace gases from cultures of Cryptococcus humicolus incubated with inorganic antimony(III) and (V) substrates. The headspace gases from biphasic (aerobic–anaerobic) biomass‐concentrated culture incubations revealed the presence of SbH₃, Me₂Sb and Me₃Sb. Stibine was the major antimony species detected in cultures amended with inorganic antimony(V). Me₃Sb was the sole volatile antimony species detected when cultures were amended with antimony(III). Copyright © 2002 John Wiley & Sons, Ltd.     

Bound formula for determining the fundamental frequency

The extent of interference with various activities was studied among populations in areas exposed to noise from aircraft, road traffic, trains and tramways. When areas with differences in the extent of general annoyance were compared, similar differences in the extent of the various activity interferences were found, except for those due to vibrations. As an example of the differences in the activity interference pattern, it was found that road traffic noise interfered significantly less with speech than train noise, whereas both noise types caused roughly the same interference with rest/sleep. The results suggest that uniform weighted annoyance scores incorporating various kinds of activity interference are not valid for all types of environmental noises. Interference due to vibrations probably has to be treated separately from that due to noise.     

Spectral Mapping Theorem for Fractional Powers of Linear Relations

In this paper, we give the fractional powers version of spectral mapping theorems for various essential spectra of non-negative linear operators and non-negative linear relations.     

High field 207Pb spin-lattice relaxation in solid lead nitrate and lead molybdate

Spin-lattice relaxation rates of lead have been measured at 17.6 T (156.9 MHz) as a function of temperature in polycrystalline lead nitrate and lead molybdate. Comparing the results with relaxation rates measured at lower fields, it is found that at high fields and low temperature, chemical shift anisotropy (CSA) makes small but observable contributions to lead relaxation in both materials. At 17.6 T and 200 K, CSA accounts for about 15% of the observed relaxation rate. Above 300 K, the dominant relaxation mechanism even at 17.6 T is an indirect Raman process involving modulation of the (207)Pb spin-rotation tensor, as first proposed by Grutzner et al. [J. Am. Chem. Soc. 123, 7094 (2001)] and later treated theoretically in more detail by Vega et al. [Phys. Rev. B 74, 214420 (2006)]. The improved signal to noise ratio at high fields makes it possible to quantify relaxation time anisotropy by analyzing saturation-recovery functions for individual frequencies on the powder pattern line shape. No orientation dependence is found for the spin-lattice relaxation rate of either material. It is argued from examination of the appropriate theoretical expressions, derived here for the first time, that the lack of observable relaxation time anisotropy is probably a general feature of this indirect Raman mechanism.     

Regioselectivity and regiospecificity of benzoxazinone (2-isopropyl-4H-3,1-benzoxazinone) derivatives toward nitrogen nucleophiles and evaluation of antimicrobial activity

A novel group of 6-iodoquinazolin-4(3H)-one derivatives was prepared. The reaction of the benzoxazinone 3 with various nitrogen nucleophiles such as formamide and hydrazine hydrate and also the reaction of the isopropylquinazolinone 4 with hydrazonyl chloride have been shown to proceed with a high degree of regioselectivity at C(2). Spiro heterocycles have been found to play fundamental roles in biological processes and have exhibited diversified biological activity and pharmacological and therapeutical properties; thus reaction of acetohydrazides 10a–c afforded the spiro compounds 11a–c. The acetohydrazide derivative 7 reacted with carbon electrophiles such as acetylacetone, ethyl acetoacetate, acid chlorides, and benzaldehyde to give some interesting heterocyclic compounds 12–16, respectively. The structures of all the synthesized compounds were inferred by infrared, ¹H NMR, and mass spectra as well as elemental analyses. The antimicrobial activities of some of the synthesized products were preliminarily evaluated.     

6-Iodo-2-isopropyl-4H-3,1-benzoxazin-4-one as building block in heterocyclic synthesis

As a part of ongoing studies in the synthesis of a variety of heterocycles of biological importance, we report here an efficient and convenient method for the synthesis of novel compounds from 6-iodo-2-isopropyl-4H-3,1-benzoxazin-4-one 1 as building block. The reaction of benzoxazinone 1 with various reagents such as diethylmalonate, sodium azide, and phosphorus pentasulfide yielded the compounds 2–5. The behavior of benzothiazin-4-thione 5 toward formamide and hydrazine hydrate was investigated, forming the compounds 6 and 7. The reaction of quinazolinone derivative 8 with β-D-glucose pentaacetate, ethyl 2-methyl-5-((1S,2R,3R)-1,2,3,4-tetrahydroxybutyl)furan-3-carboxylate, epichlorohydrin and benzenesulphonyl chloride afforded quinazolinone derivatives 9, 10, 12, and 13 respectively. The reaction of quinazolinone derivative 10 with acetic anhydride resulted in formation of the acylated compound 11. The behavior of quinazolinylacetohydrazide derivative 14 toward carbon electrophiles^[16 El-Hashash, M. A.; El-Naggar, A. M.; El-Bordany, E. A.; Marzouk, M. I.; Nawar, T. M. S. Regioselectivity and regiospecificity of benzoxazinone (2-isopropyl4H-3,1-benzoxazinone) derivatives toward nitrogen nucleophiles and evaluation of antimicrobial activity. Synth. Commun. 2016, 46(14), 1230–1241.[Taylor & Francis Online], [Web of Science ®] , [Google Scholar]^] has been investigated by its reaction with ethyl benzoylacetate, potassium thiocyanate, and phenyl isothiocyanate, affording the quinazolinone derivatives 15, 16, and 18, respectively. Treatment of compound 16 with sodium hydroxide followed by hydrochloric acid yielded the mercapto-triazole derivative 17. The structures of the newly synthesized compounds were confirmed by elemental analysis, infrared (IR), ¹H NMR, ¹³C NMR, and mass spectra. The antimicrobial activities of some of the synthesized compounds were preliminarily evaluated.     

Tin(IV) cyanoximates: synthesis, characterization, and cytotoxicity

In recent years, numerous organotin(IV) derivatives have exhibited remarkable cytotoxicity against several types of cancer. However, the properties of the cyanoxime-containing organotin(IV) complexes are unknown. Previously, it has been shown that cyanoximes displayed an interesting spectrum of biological activity ranging from growth-regulation to antimicrobial and pesticide detoxification actions. The work presented here attempts to combine the useful properties of both groups of compounds and investigate the likely antiproliferating activity of the new substances. A series of 19 organotin(IV) complexes, with nine different cyanoxime ligands, were anaerobically prepared by means of the heterogeneous metathesis reaction between the respective organotin(IV) halides (Cl, Br) and ML (M=Ag, Tl; L=cyanoximate anion), using an ultrasound in the CH3CN at room temperature. The compounds were characterized using spectroscopic methods (UV-visible, IR, 1H,13C NMR, 119Sn M?ssbauer) and X-ray analysis. The crystal structures of the complexes revealed the formation of two types of tin(IV) cyanoximates: mononuclear five-coordinated compounds of R4-xSnLx composition (R=Me, Et, n-Bu, Ph; x=1, 2; L=cyanoximate anion), and the tetranuclear R8Sn4(OH)2O2L2 species (R=n-Bu, Ph). The latter complex contains a planar [Sn4(OH)2O2]2- core, consisting of three adjacent rhombs with bridging oxo and hydroxo groups. The tin(IV) atoms are five-coordinated and have distorted trigonal-pyramidal surrounding. This is the first instance when the organic anions were found to act as monodentate O-bound planar oxime ligands. All of the compounds were studied in vitro for antiproliferating activity, using human cervical cancer HeLa and WiDR colon cancer cell lines; cisplatin was used as a positive control substance. The two dibutyltin(IV) cyanoximates showed cytotoxicity similar and greater to that of cisplatin.