On the structure, electrochemistry, and spectroscopy of the (N,N'-bis(2'-(dimethylamino)ethyl)-N,N'-dimethylpropane-1,3-diamine)copper(II) ion

The synthesis, spectroscopy, and electrochemistry of the acyclic tertiary tetraamine copper(II) complex [CuL(1)](ClO4)(2) (L(1) = N,N-bis(2'-(dimethylamino)ethyl)-N,N'-dimethylpropane-1,3-diamine) is reported. The X-ray crystal structure of [CuL(1)(OClO3)(2)] reveals a tetragonally elongated CuN4O2 coordination sphere, exhibiting relatively long Cu-N bond lengths for a Cu-II tetraamine, and a small tetrahedral distortion of the CuN4 plane. The [CuL(1)](2+) ion displays a single, reversible, one-electron reduction at -0.06 V vs Ag/AgCl. The results presented herein illustrate the inherent difficulties associated with the separation and characterization of Cu-II complexes of tertiary tetraamines, and some previously incorrect assertions and unexplained observations of other workers are discussed.

Atmospheric corrosion of copper at Heron Island

Atmospheric corrosion tests have been conducted at Heron Island, Queensland, a low SO2 marine environment. The corrosion rates for copper followed the linear bi-logarithmic law. X-ray diffraction identified atacamite (basic copper chloride) and cuprite (cuprous oxide) as the predominant corrosion products. Biogenic and anthropogenic sources of pollution did not have a measurable influence.

Chemical treatment of Escherichia coli .1. Extraction of intracellular protein from uninduced cells

Extraction of intracellular protein from Escherichia coli is traditionally achieved by mechanical disruption. A chemical treatment that destroys the integrity of the bacterial cell wall and could provide an alternative technique is examined in this study. Treatment with a combination of the chelating agent ethylenediaminetetraacetate (EDTA) (greater than 0.3 mM) and the chaotropic agent urea (6 M) is highly effective at releasing protein from uninduced E. coli. The 6 M urea in the presence of 3 mM EDTA can release cytoplasmic protein from both logarithmic-phase and stationary-phase E. coli cells at levels equivalent to mechanical disruption. The concentrations of the two chemical agents were the major variables affecting the maximum levels of protein release. Several minor variables and interactions were also identified. The kinetics of protein release is first order. For 2, 4, and 6 M urea with 3 mM EDTA, the time constant is approximately 2.5 min independent of urea concentration. Kinetics for 3 mM EDTA without urea is considerably slower, with a time constant of 12.3 min. (C) 1997 John Wiley & Sons, Inc.

Self-assembly of a tetranuclear macrocyclic copper(II) complex

A dinuclear macrocyclic complex is synthesized via the one-pot reaction of dipotassium nitroacetate, formaldehyde and a linear tetraamine copper(II) complex; the X-ray crystal structure of the product reveals an association of two dinuclear complexes to form a novel tetracopper(II) species.

Nitrogen- and carbon-based isomerism in the copper(II) complexes of 6,13-dimethyl-1,4,8,11-tetraazacyclotetradecane-6,13-diamine

A number of N- and C-based diastereomeric copper(II) complexes of the pendant-arm macrocyclic hexaamines trans- and cis-6,13-dimethyl-1,4,8,11-tetraazacyclotetradecane-6,13-diamine (L-1 and L-2) have been isolated and characterised. The crystal structures of the complexes RRSS-[CuL1(OH2)(2)][ClO4](2), SSRR-[Cu(H2L1)(OClO3)(2)]-[ClO4](2) . 2H(2)O RSRS-[CuL1(OClO3)]ClO4, RSRS-[CuL2(OClO3)]ClO4 and RRSS-[Cu(H2L2)(OClO3)(2)][ClO4](2) have been determined. Some unusual structural and spectroscopic variations are found across this series of diastereomers. The protonation constants of the pendant primary amines are dependent on the relative dispositions of the adjacent macrocyclic secondary amine H atoms, which is indicative of intramolecular hydrogen-bonding interactions.

Properties of rapidly solidified binary copper alloys

A number of binary Cu-X alloys (X = Fe, Cr, Si and Al) with alloying elements up to approximate to 12 at % for Fe and Cr, and = 20 at% for Al and Si were cast into thin ribbons (30-50 mu m thickness) by chill block melt spinning. The structural state of the as-cast ribbons was determined by X-ray diffraction (XRD) and microstructures of the quenched alloys were compared with the ingot equivalent, It was possible to achieve solid solution and fine dispersion of secondary phase beyond XRD detection up to approximate to 8 at% solute for Fe and Cr, which is beyond the expected concentration limits from equilibrium phase diagrams. The effects of alloying on resistivity and microhardness are also presented.

Extraction of electrical characteristics from pixels of multifrequency EIT images

Computer modelling has shown that electrical characteristics of individual pixels may be extracted from within multiple-frequency electrical impedance tomography (MFEIT) images formed using a reference data set obtained from a purely resistive, homogeneous medium. In some applications it is desirable to extract the electrical characteristics of individual pixels from images where a purely resistive, homogeneous reference data set is not available. One such application of the technique of MFEIT is to allow the acquisition of in vivo images using reference data sets obtained from a non-homogeneous medium with a reactive component. However, the reactive component of the reference data set introduces difficulties with the extraction of the true electrical characteristics from the image pixels. This study was a preliminary investigation of a technique to extract electrical parameters from multifrequency images when the reference data set has a reactive component. Unlike the situation in which a homogenous, resistive data set is available, it is not possible to obtain the impedance and phase information directly from the image pixel values of the MFEIT images data set, as the phase of the reactive reference is not known. The method reported here to extract the electrical characteristics (the Cole-Cole plot) initially assumes that this phase angle is zero. With this assumption, an impedance spectrum can be directly extracted from the image set. To obtain the true Cole-Cole plot a correction must be applied to account for the inherent rotation of the extracted impedance spectrum about the origin, which is a result of the assumption. This work shows that the angle of rotation associated with the reactive component of the reference data set may be determined using a priori knowledge of the distribution of frequencies of the Cole-Cole plot. Using this angle of rotation, the true Cole-Cole plot can be obtained from the impedance spectrum extracted from the MFEIT image data set. The method was investigated using simulated data, both with and without noise, and also for image data obtained in vitro. The in vitro studies involved 32 logarithmically spaced frequencies from 4 kHz up to 1 MHz and demonstrated that differences between the true characteristics and those of the impedance spectrum were reduced significantly after application of the correction technique. The differences between the extracted parameters and the true values prior to correction were in the range from 16% to 70%. Following application of the correction technique the differences were reduced to less than 5%. The parameters obtained from the Cole-Cole plot may be useful as a characterization of the nature and health of the imaged tissues.

Evaluating SVM and MLDA in the extraction of discriminant regions for mental state prediction

Pattern recognition methods have been successfully applied in several functional neuroimaging studies. These methods can be used to infer cognitive states, so-called brain decoding. Using such approaches, it is possible to predict the mental state of a subject or a stimulus class by analyzing the spatial distribution of neural responses. In addition it is possible to identify the regions of the brain containing the information that underlies the classification. The Support Vector Machine (SVM) is one of the most popular methods used to carry out this type of analysis. The aim of the current study is the evaluation of SVM and Maximum uncertainty Linear Discrimination Analysis (MLDA) in extracting the voxels containing discriminative information for the prediction of mental states. The comparison has been carried out using fMRI data from 41 healthy control subjects who participated in two experiments, one involving visual-auditory stimulation and the other based on bimanual fingertapping sequences. The results suggest that MLDA uses significantly more voxels containing discriminative information (related to different experimental conditions) to classify the data. On the other hand, SVM is more parsimonious and uses less voxels to achieve similar classification accuracies. In conclusion, MLDA is mostly focused on extracting all discriminative information available, while SVM extracts the information which is sufficient for classification. (C) 2009 Elsevier Inc. All rights reserved.

Organ-Sparing Microsurgical Resection of Incidental Testicular Tumors Plus Microdissection for Sperm Extraction and Cryopreservation in Azoospermic Patients: Surgical Aspects and Technical Refinements

INTRODUCTION The management of nonpalpable testicular masses is a challenging task, and coexisting infertility can further complicate the treatment decisions. We present our technique for microsurgical organ-sparing resection of incidental nonpalpable testicular nodules combined with microdissection for testicular sperm extraction and tissue cryopreservation in azoospermic patients. TECHNICAL CONSIDERATIONS Five infertile patients with azoospermia presented with nonpalpable hypoechoic testicular masses that were detected by Ultrasonography and underwent organ-sparing surgery. The testis was delivered through an inguinal incision, and the blood circulation was interrupted with a vascular clamp placed on the spermatic cord. Sludged ice was used to prevent warm ischemia, and a temperature probe was used to control the temperature at 12 degrees-15 degrees C. Real-time reflex ultrasonography was used to locate the tumor, and a stereotaxic hook-shaped needle was inserted under ultrasound guidance. The needle was placed adjacent to the tumor to guide the microsurgical resection. The tunica albuginea was incised over the tumor, which was dissected and removed, along with the adjoining parenchymal tissue. Frozen section studies were performed and, if malignancy was confirmed, biopsies of the tumor cavity margins and remaining parenchyma were obtained to ensure the absence of residual tumor. Microdissection was performed for excision of selected enlarged tubules that were processed and cryopreserved. CONCLUSIONS We present a technique for microsurgical organ-sparing resection of testicular tumor and sperm extraction that can be used in selected infertile patients with azoospermia in whom incidental masses have been diagnosed by ultrasonography. This conservative approach should be especially considered for patients with a solitary testis or bilateral tumors. UROLOGY 73: 887-892, 2009. (C) 2009 Elsevier Inc.

Macrocycle formation through carbon acid-formaldehyde condensation reactions of bis(propane-1,2-diamine)- and bis (2-methylpropane-1,2-diamine)-copper(II) ions

The reaction of the bis(1,2-diamine) copper(II) complexes of racemic propane-1,2-diamine (pn) and 2-methylpropane-1,2-diamine (dmen) with formaldehyde and nitroethane in methanol under basic conditions yields minor macrocyclic condensation products in addition to the major acyclic products. Where C-pendant methyl groups on the pair of coordinated diamines are in cis dispositions, the first -NH-CH2-C(CH3)(NO2)-CH2-NH- ring formation occurs at amine pairs distant from these C-methyl substituents, and further reaction to yield a macrocycle is not observed. However, where the C-methyl substituents are in trans dispositions, the chemistry proceeds to yield the macrocycle. Commencing with pn, trans-(6,13-diammonio-2,6,9,13-tetramethyl-1,4,7,10-tetraazacyclotetradecane)copper(II) perchlorate formed and crystallized in the space group P2(1)/n, with a 9.782(2), b 9.2794(6), c 17.017(4) Angstrom, beta 103.24(1)degrees. The copper ion is found in a square-planar environment, with the two methyl groups of the pn residues and the pairs of introduced pendant groups all in trans arrangements.

Geometric and electronic information from the spectroscopy of six-coordinate copper(II) compounds

The ground and excited state geometry of the six-coordinate copper(II) ion is examined in detail using the CuF64- and Cu(H2O)(6)(2+) complexes as examples. A variety of spectroscopic techniques are used to illustrate the relations between the geometric and electronic properties of these complexes through the characterization of their potential energy surfaces.

An easy method for handling the genus Phoneutria (Araneae, Ctenidae) for venom extraction

This paper describes an easy, cheap, and safe method of capturing and handling the medically important spider Phoneutria for venom extraction. The method does not injure or kill the spider and allows the extraction of pure venom.

Histological and histomorphometrical alterations of the periodontal ligament in gerbils submitted to teeth extraction

This study verified the effect of unilateral teeth extraction on the periodontal ligament in gerbils (Meriones unguiculatus). Ten adult male gerbils weighing about 50 g had induced occlusal alterations by upper left molar extractions while the other ten animals, only submitted to surgical stress, were considered as controls. The periodontal ligament was characterized by qualitative and quantitative analysis, histological description and histomorphometric quantification. Significant alterations were observed on the left side of the experimental group (P < 0.05), the hypofunctional region, when it was compared with the contralateral side and the corresponding region of the control group. Two months after occlusal alterations induced by unilateral teeth extraction, atrophic histological alterations and a decrease in the periodontal space on the ipsilateral side characterized the periodontal ligament. In this study it was possible to conclude that the gerbil can be used in experimental models attempting to correlate the periodontium`s biological response to various mechanical stresses, as the periodontal ligament was shown to be highly sensitive to occlusal alterations.

Hepatogenous photosensitization associated with liver copper accumulation in buffalos

Four 1.5-year-old, male, Murrah buffalos were maintained during eight months without direct solar exposure during a study of copper toxicosis. Four days after solar exposure, all buffalos presented clinical manifestations consistent with acute photosensitization, including anorexia, apathy, loss of body weight, and generalized cutaneous lesions. Gross lesions were characterized by severe erythema, localized edema, fissures, tissue necrosis, gangrene and crust formation with h serous exudation. Liver copper concentration was evaluated, and cutaneous biopsies were taken when clinical signs were evident. The liver copper concentration before solar exposure was increased in all animals. Histopathologic examination of the skin revealed hepatogenous photosensitization characterized by parakeratotic hyperkeratosis, acantholysis, degeneration of squamous epithelial cells, epidermal necrosis with atrophy of sweat glands, and multifocal superficial and deep dermal edema. These findings suggest that asymptomatic accumulation of copper within the liver might have induced hepatic insufficiency thereby resulting in secondary photosensitization when these buffalos were exposed to sunlight. (C) 2009 Elsevier Ltd. All rights reserved.