Photochemical Reactions of fac-[Mn(CO)(3)(phen)imidazole](+): Evidence for Long-Lived Radical Species Intermediates

The electronic absorption spectrum of fac[Mn(CO)(3)(phen)imH](+), fac-1 in CH(2)Cl(2) is characterized by a strong absorption band at 378 nm (epsilon(max) = 3200 mol(-1) L cm(-1)). On the basis of quantum mechanical calculations, the visible absorption band has been assigned to ligand-to-ligand charge-transfer (LLCT, im -> phen) and metal-to-ligand charge-transfer (MLCT, Mn -> phen) charge transfer transition. When fac-1 in CH(2)Cl(2) is irradiated with 350 nm continuous light, the absorption features are gradually shifted to represent those of the meridional complex mer-[Mn(CO)(3)(phen)imH](+), mer-1 (lambda(max) = 556 nm). The net photoreaction under these conditions is a photoisomerization, although, the presence of the long-lived radical species was also detected by (1)H NMR and FTIR spectroscopy. 355 nm continuous photolysis of fac-1 in CH(3)CN solution also gives the long-lived intermediate which is readly trapped by metylviologen (MV(2+)) giving rise to the formation of the one-electron reduced methyl viologen (MV(center dot+)). The UV-vis spectra monitored during the slow (45 min) thermal back reaction exhibited isosbestic conversion at 426 nm. On the basis of spectroscopic techniques and quantum mechanical calculations, the role of the radicals produced is analyzed.

Er(3+) doped phosphoniobate glasses and planar waveguides: structural and optical properties

Phosphoniobate glasses with composition (mol%) (100-x) NaPO(3)-xNb(2)O(5) ( x varying from 11 to 33) were prepared and characterized by means of thermal analysis, Fourier transform infrared spectroscopy, Raman scattering and (31)P nuclear magnetic resonance. The addition of Nb(2)O(5) to the polyphosphate base glass leads to depolymerization of the metaphosphate structure. Different colors were observed and assigned as indicating the presence of Nb(4+) ions, as confirmed by electron paramagnetic resonance measurements. The color was observed to depend on the glass composition and melting temperature as well. Er(3+) containing samples were also prepared. Strong emission in the 1550 nm region was observed. The Er(3+4)I(15/2) emission quantum efficiency was observed to be 90% and the quenching concentration was observed to be 1.1 mol%( 1.45 x 10(20) ions cm(-3)). Planar waveguides were prepared by Na(+)-K(+)-Ag(+) ion exchange with Er(3+) containing samples. Optical parameters of the waveguides were measured at 632.8, 543.5 and 1550 nm by the prism coupling technique as a function of the ion exchange time and Ag(+) concentration. The optimized planar waveguides show a diffusion depth of 5.9 mu m and one propagating mode at 1550 nm.

Fermentative production of hydrogen from cassava processing wastewater by Clostridium acetobutylicum

This work reports on the effect of initial substrate concentration on COD consumption, pH, and H(2) production during cassava processing wastewater fermentation by Clostridium acetobutylicum ATCC 824. Five initial COD wastewater concentrations, namely 5.0, 7.5, 10.7, 15.0, and 30.0 g/L, were used. The results showed that higher substrate concentrations (30.0 and 15.0 COD/L) led to lower H(2) yield as well as less efficient substrate conversion into H(2). On the other hand, initial COD concentrations of 10.7, 7.5 and 5 g/L furnished 1.34, 1.2 and 2.41 mol H(2)/mol glucose, with efficiency of glucose conversion into H(2) of 34, 30, and 60% (mol/mol), respectively. These results demonstrate that cassava processing wastewater, a highly polluting effluent, can be successfully employed as substrate for H(2) production by C acetobutylicum at lower COD concentrations. (C) 2011 Elsevier Ltd. All rights reserved.

Reverse Microemulsion Synthesis, Structure, and Luminescence of Nanosized REPO(4):Ln(3+) (RE = La, Y, Gd, or Yb, and Ln = Eu, Tm, or Er)

A surfactant-mediated solution route for the obtainment of nanosized rare-earth orthophosphates of different compositions (LaPO(4):Eu(3+), (Y,Gd)PO(4):Eu(3+),LaPO(4):Tm(3+), YPO(4):Tm(3+), and YbPO(4):Er(3+)) is presented, and the implications of the morphology control on the solids properties are discussed. The solids are prepared in water-in-heptane microemulsions, using cetyltrimethylammonium bromide and 1-butanol as the surfactant and cosurfactant; the alteration of the starting microemulsion composition allows the obtainment of similar to 30 nm thick nanorods with variable length. The morphology and the structure of the solids were evaluated through scanning electron microscopy and through powder X-ray diffractometry; dynamic light scattering and thermal analyses were also performed. The obtained materials were also characterized through vibrational (FTIR) and luminescence spectroscopy (emission/excitation, luminescence lifetimes, chromaticity, and quantum efficiency), where the red, blue, and upconversion emissions of the prepared phosphors were evaluated.

Sol-gel preparation of near-infrared broadband emitting Er(3+)-doped SiO(2)-Ta(2)O(5) nanocomposite films

This article reports a study on the preparation, densification process, and structural and optical properties of SiO(2)-Ta(2)O(5) nanocomposite films obtained by the sol-gel process. The films were doped with Er(3+) and the Si:Ta molar ratio was 90:10. Values of refractive index, thickness and vibrational modes in terms of the number of layers and thermal annealing time are described for the films. The densification process is accompanied by OH group elimination, increase in the refractive index, and changes in film thickness. Full densification of the film is acquired after 90 min of annealing at 900 degrees C. The onset of crystallization and devitrification, with the growth of Ta(2)O(5) nanocrystals occurs with film densification, evidenced by high-resolution transmission electron microscopy. The Er(3+)-doped nanocomposite annealed at 900 degrees C consists of Ta(2)O(5) nanoparticles, with sizes around 2 nm, dispersed in the SiO(2) amorphous phase. The main emission peak of the film is detected at around 1532 nm, which can be assigned to the (4)I(13/2)->(4)I(15/2) transition of the Er(3+) ions present in the nanocomposites. This band has a full width at half medium of 64 nm, and the lifetime measured for the (4)I(13/2) levels is 5.4 ms, which is broader compared to those of other silicate systems. In conclusion, the films obtained in this work are excellent candidates for use as active planar waveguide. (C) 2010 Elsevier B.V. All rights reserved.

Religions and cultures: Religious dynamics in Latin America

The author seeks to analyse the relationships between religion and culture in Latin America, especially in Brazil, highlighting the fact that the different religions enjoy diverse relationships with culture in a single location. He also addresses the fact that religions interpret culture in different ways and these interpretations help define their conversion strategies and how best to confront opposing religions. For the sake of discussion, the author considers, hypothetically, a not-so-distant future in which Latin America becomes predominantly evangelical, and asks what will happen to Latin America`s supposed Catholic culture if the evangelical religions do indeed take over.

46,XY DSD due to impaired androgen production

Disorders of androgen production can occur in all steps of testosterone biosynthesis and secretion carried out by the foetal Leydig cells as well as in the conversion of testosterone into dihydrotestosterone (DHT). The differentiation of Leydig cells from mesenchymal cells is the first walk for testosterone production. In 46,XY disorders of sex development (DSDs) due to Leydig cell hypoplasia, there is a failure in intrauterine and postnatal virilisation due to the paucity of interstitial Leydig cells to secrete testosterone. Enzymatic defects which impair the normal synthesis of testosterone from cholesterol and the conversion of testosterone to its active metabolite DHT are other causes of DSD due to impaired androgen production. Mutations in the genes that codify the enzymes acting in the steps from cholesterol to DHT have been identified in affected patients. Patients with 46,XY DSD secondary to defects in androgen production show a variable phenotype, strongly depending of the specific mutated gene. Often, these conditions are detected at birth due to the ambiguity of external genitalia but, in several patients, the extremely undervirilised genitalia postpone the diagnosis until late childhood or even adulthood. These patients should receive long-term care provided by multidisciplinary teams with experience in this clinical management. (C) 2009 Elsevier Ltd. All rights reserved.

The common p450 oxidoreductase variant A503V is not a modifier gene for 21-hydroxylase deficiency

Context: 21-hydroxylase deficiency (21OHD) is a common genetic disorder caused by mutations in the CYP21A2 gene, which encodes the adrenal 21-hydroxylase, microsomal P450c21. CYP21A2 gene mutations generally correlate well with impaired P450c21 enzymatic activity and the clinical findings in 21OHD, but occasional discrepancies between genotype and phenotype suggest the effects of modifier genes. Mutations in P450 oxidoreductase (POR), the protein that transfers electrons from reduced nicotinamide adenine dinucleotide phosphate to all microsomal P450s, can ameliorate the 21OHD phenotype and, therefore, could be a modifier gene. Objectives: We sought to identify POR variants in patients with 21OHD having discordant phenotype and genotype, and to evaluate their effect on 21-hydroxylase activity. Patients and Methods: We determined the CYP21A2 genotypes of 313 Brazilian patients with 21OHD and correlated the genotype and phenotype. The POR gene was sequenced in 17 patients with discordant genotype and phenotype. Wild-type and A503V POR, and P450c21 were expressed in bacteria and reconstituted in vitro. Activities were assayed by conversion of [C-14] progesterone to deoxycorticosterone and [H-3]17-hydroxyprogesterone to 11-deoxycortisol, and assessed by thin layer chromatography and phosphorimaging. Results: The A503V POR variant was found in 10 of 30 alleles, the same ratio as in the normal population. There were no significant differences in Michaelis constant, maximum velocity and maximum velocity/Michaelis constant of 21-hydroxylase activity supported by wild-type and A503V POR. Conclusion: The only POR missense polymorphism found in atypical 21OHD patients was A503V. Although A503V reduces P450c17 enzymatic activity, it does not influence P450c21 activity, indicating that POR A503V does not modify the 21OHD phenotype.

Surgical Treatment of Morbid Obesity: Mid-term Outcomes of the Laparoscopic Ileal Interposition Associated to a Sleeve Gastrectomy in 120 Patients

The aim of this study was to evaluate the mid-term outcomes of the laparoscopic ileal interposition associated to a sleeve gastrectomy (LII-SG) for the treatment of morbid obesity. The procedure was performed in 120 patients: 71 women and 49 men with mean age of 41.4 years. Mean body mass index (BMI) was 43.4 +/- 4.2 kg/m(2). Patients had to meet requirements of the 1991 NIH conference criteria for bariatric operations. Associated comorbidities were observed in all patients, including dyslipidemia in 51.7%, hypertension in 35.8%, type 2 diabetes in 15.8%, degenerative joint disease in 55%, gastroesophageal reflux disease in 36.7%, sleep apnea in 10%, and cardiovascular problems in 5.8%. Mean follow-up was 38.4 +/- 10.2 months, range 25.2-61.1. There was no conversion to open surgery nor operative mortality. Early major complications were diagnosed in five patients (4.2%). Postoperatively, 118 patients were evaluated. Late major complications were observed in seven patients (5.9%). Reoperations were performed in six (5.1%). Mean postoperative BMI was 25.7 +/- 3.17 kg/m(2), and 86.4% were no longer obese. Mean %EWL was 84.5 +/- 19.5%. Hypertension was resolved in 88.4% of the patients, dyslipidemia in 82.3%, and T2DM in 84.2%. The LII-SG provided an adequate weight loss and resolution of associated diseases during mid-term outcomes evaluation. There was an acceptable morbidity with no operative mortality. It seems that chronic ileal brake activation determined sustained reduced food intake and increased satiety over time. LII-SG could be regularly used as a surgical alternative for the treatment of morbid obesity.

Thirty-Day Morbidity and Mortality of the Laparoscopic Ileal Interposition Associated with Sleeve Gastrectomy for the Treatment of Type 2 Diabetic Patients with BMI < 35: An Analysis of 454 Consecutive Patients

Background The objective of this study was to evaluate the early results of the laparoscopic interposition of a segment of ileum associated with a sleeve gastrectomy (LII-SG) in order to treat patients with type 2 diabetes mellitus (T2DM) and BMI <35. Data regarding morbidly obese diabetic patients subjected to surgery has consistently been validated. To date, there is scarce information about morbidity and mortality related to the surgical treatment of a ""true"" typical diabetic population with BMI <35. Methods The procedures were performed in 454 patients (322 male, 132 female). Mean age was 53.6 +/- 8 years (range = 27-75). Mean BMI was 29.7 +/- 3.6 kg/m(2) (range = 19-34.8). All patients had the diagnosis of T2DM for at least 3 years. Insulin therapy was used by 45.6% of patients. Mean duration of T2DM was 10.8 +/- 5.9 years (range = 3-35). Mean hemoglobin A(1c) was 8.8 +/- 1.9%. Dyslipidemia was observed in 78.4%, hypertension in 64.8%, nephropathy in 28.6%, retinopathy in 32.6%, neuropathy in 34.6%, and coronary heart disease in 13%. Results There was no conversion to open surgery. All patients were evaluated postoperatively. Mortality was 0.4%. There were 29 major complications (6.4%) in 22 patients (4.8%) and 51 minor complications (11.2%). Reoperations were performed on 8 patients (1.7%). Twenty patients (4.4%) were readmitted to the hospital. Mean postoperative BMI was 25.8 +/- 3.5 kg/m(2). Mean fasting plasma glucose decreased from 198 +/- 69 to 128 +/- 67 mg/dl and mean postprandial plasma glucose decreased from 262 +/- 101 to 136 +/- 43 mg/dl. Conclusions The laparoscopic ileal interposition associated with a sleeve gastrectomy was considered a safe operation with low rates of morbidity and mortality in a diabetic population with BMI < 35. An early control of postprandial glycemia was observed.

Processing of mutated human proinsulin to mature insulin in the non-endocrine cell line, CHO

Heterologous genes encoding proproteins, including proinsulin, generally produce mature protein when expressed in endocrine cells while unprocessed or partially processed protein is produced in non-endocrine cells. Proproteins, which are normally processed in the regulated pathway restricted to endocrine cells, do not always contain the recognition sequence for cleavage by furin, the endoprotease specific to the constitutive pathway, the principal protein processing pathway in non-endocrine cells. Human proinsulin consists of B-Chain-C-peptide-A-Chain and cleavage at the B/C and C/A junctions is required for processing. The B/C, but not the C/A junction, is recognised and cleaved in the constitutive pathway. We expressed a human proinsulin and a mutated proinsulin gene with an engineered furin recognition sequence at the C/A junction and compared the processing efficiency of the mutant and native proinsulin in Chinese Hamster Ovary cells. The processing efficiency of the mutant proinsulin was 56% relative to 0.7% for native proinsulin. However, despite similar levels of mRNA being expressed in both cell lines, the absolute levels of immunoreactive insulin, normalized against mRNA levels, were 18-fold lower in the mutant proinsulin-expressing cells. As a result, there was only a marginal increase in absolute levels of insulin produced by these cells. This unexpected finding may result from preferential degradation of insulin in non-endocrine cells which lack the protection offered by the secretory granules found in endocrine cells.

Laparoscopic extended cardiomyotomy in children: an effective procedure for the treatment of esophageal achalasia

Purpose: Achalasia of the esophagus is characterized by aperistalsis and incomplete relaxation of the lower esophageal sphincter in response to swallowing. The objective of the present study is to present the experience of a modified Heller myotomy via a laparoscopic approach for the treatment of children who had this condition. Methods: A retrospective review of medical records of all patients who underwent this procedure from 2000 to 2009 was performed. The procedure consisted of an extended esophagomyotomy beginning on the lower part of the lower esophageal sphincter and continuing 5 to 6 cm above on the lower third of the esophagus, and then extended 3 to 4 cm below to the stomach, associated with an anterior 180-degree hemi-fundoplication according to Dor`s technique. Results: Fifteen patients were included in the study. There were 8 female and 7 male patients. Mean operating time was 190 minutes with no intraoperative complications and 1 conversion to open surgery because of difficulty in dissecting an inflamed distal esophagus. In a mean follow-up period of 32.3 months, 2 patients had recurrence of mild dysphagia that disappeared spontaneously, and 1 required a single botulinum toxin injection with complete resolution of symptoms. Conclusion: We conclude that the laparoscopic extended Heller myotomy with Dor fundoplication is a safe and effective method for the treatment for achalasia in the pediatric population even in advanced cases. (C) 2010 Elsevier Inc. All rights reserved.

Standard Examination System for Laparoscopy in Penetrating Abdominal Trauma

Background: The high missed occult small bowel injuries (SBI) associated with laparoscopy in trauma (LIT) is a major reason why some surgeons still preclude LIT today. No standardized laparoscopic examination for evaluation of the peritoneal cavity is described for trauma. The objective of this article is to verify if a systematic standardized laparoscopic approach could correctly identify SBI in the peritoneal cavity for penetrating abdominal trauma (PAT). Methods: Victims with PAT were evaluated in a prospective, nonrandomized study. A total of 75 hemodynamically stable patients with suspected abdominal injuries were operated by LIT and converted to laparotomy if criteria were met: SBI and lesions to blind spot zones-retroperitoneal hematoma, injuries to segments VI or VII of the liver, or injuries to the posterior area of the spleen. Inclusion criteria were equivocal evidence of abdominal injuries or peritonea] penetration; systolic blood pressure >90 mm Hg and <3 L of IV fluids in the first hour of admission; Glasgow Coma Scale score >12; and age >12 years. Exclusion criteria were back injuries; pregnancy; previous laparotomy; and chronic cardiorespiratory disease. Results: Sixty patients were males and there were 38 stab wounds and 37 gunshot wounds. No SBI was missed, but a pancreatic lesion was undiagnosed due to a retroperitoneal hematoma. Twenty patients (26.6%) were converted. Unnecessary laparotomies were avoided in 73.33%. Therapeutic LIT was possible in 22.7%. Accuracy was 98.66% with 97.61% sensitivity and 100% specificity. Conclusions: Standard systematic laparoscopic exploration was 100% effective to detect SBI in the peritoneal cavity. Conversion from LIT to laparotomy should be done if injuries to blind spot zones are found which are poorly evaluated by LIT. Therapeutic LIT is feasible in PAT.

Studies on the gelation of photocatalysed dicyanate ester resins

The gel point of a dicyanate ester resin (Arocy B-10 (4-4'-dicyanato-2,2'-diphenylpropane)) heated following irradiation in the presence of the catalyst tricarbonyl cyclopentadienyl manganese (CpMn(CO)(3)) was studied using differential scanning calorimetry (d.s.c.) and dynamic rheological techniques over the temperature range 110-140 degrees C. The gel times of another commercial cyanate ester (RTX366) were also studied using independent rheological techniques, and the results agreed within experimental error. Gel times decreased linearly with increasing catalyst level and with increasing temperature according to an Arrhenius relation with activation energy of 68 +/- 6 kJmol(-1). The gel conversion was calculated by correlation of the rheological gel data to d.s.c. data to be 0.57 +/- 0.02, and differences between techniques, and between theoretical predictions, are discussed. Evidence is produced that the photocatalysed polymerization results in a greater rate of cyclotrimerization, less intramolecular cyclization and a more rigid network than the uncatalysed or metal salt-catalysed high-temperature polymerization. (C) 1997 Elsevier Science Ltd.

Classical and quantum signatures of competing chi((2)) nonlinearities

We report the observation of the quantum effects of competing chi((2)) nonlinearities. We also report classical signatures of competition, namely, clamping of the second-harmonic power and production of nondegenerate frequencies in the visible. Theory is presented that describes the observations as resulting from competition between various chi((2)) up-conversion and down-conversion processes. We show that competition imposes hitherto unsuspected limits to both power generation and squeezing. The observed signatures are expected to be significant effects in practical systems.