Silver Nanoparticle Films Obtained by Convective Self-Assembly for Surface-Enhanced Raman Spectroscopy Analyses of the Pesticides Thiabendazole and Endosulfan.

Pesticides pose a great threat to human health and their rapid detection has become an urgent public safety issue engaging the scientific community to search for fast and reliable detection techniques. In this context, Surface Enhanced Raman Spectroscopy (SERS) has emerged as a valuable detection and analysis tool due to its high sensitivity and selectivity, proving its suitability for the food industry and environmental monitoring applications. Here, we report on the fabrication of colloidal silver nanoparticle (AgNP) films by convective self-assembly (CSA) on solid planar substrate and their use for the SERS analyses of two types of pesticides, the fungicide thiabendazole (TBZ) and the insecticide α-endosulfan (α-ES). Electron microscopy shows that these nanoparticle films are dense, highly compact, and uniform across several mm2 areas. The SERS efficiency of the fabricated AgNP films is evaluated using a well-known Raman probe, p-aminothiophenol, for multiple excitation laser lines (532 nm, 633 nm, and 785 nm). The films exhibit the largest SERS enhancement factors for 785 nm excitation, reaching values larger than 105. Thiabendazole could be readily adsorbed on the AgNPs without any sample surface functionalization and detected down to 10-6 M, reaching the sub-ppm range. Endosulfan, a challenging analyte with poor affinity to metal surfaces, was captured near the metal surface by using self-assembled alkane thiol monolayers (hexanethiol and octanethiol), as demonstrated by the thorough vibrational band analysis, and supported by density functional theory (DFT) calculations. In addition, principal component analysis (PCA) based on SERS spectra offers significant leverage in discrimination of the molecules anchored onto the metallic nanostructured surface. This present study demonstrates the utility of self-assembled colloidal nanoparticle films as SERS substrates for a broad range of analytes (para-aminothiophenol, thiabendazole, α-endosulfan, and alkanethiols) and contributes to the development of SERS-based sensors for pesticides detection, identification and monitoring.

Characterization of the relations between morphology and physiological status of the pineal gland in connection with the somatic development level in turkeys reared in Romania / Caracterização das relações entre morfologia e estado fisiológico da glândula pineal em conexão com o nível de desenvolvimento somático em perus criados na România

This research started from the premises of the existence of some possible relationships between indole and pineal peptide hormones and the somatic development, with participation of hypothalamic-pituitary complex. Experimental factors, which were the subject of the present paper, influenced the dynamics of corporal mass and fodder consumption, leading to the occurrence of some important structural modifications at the level of pineal gland. The exposure of the individuals to continuous light (photic pinealectomy) produces increases in corporal mass, showing the involvement of the pineal gland in neuro-endocrine-metabolic reactions, which contributes to the maintenance of homeostatic balance, including somatic ones. Biological material was represented by a number of 50 individuals belonging to B.U.T. Big 6 hybrid, reared on soil, on a permanent litter, which could assure the expanding of knowledge area regarding the relation between rearing technology, modulation of some microclimate parameters and growing performances. Were also realised cytometric and hystometric muscular determinations.

A pesquisa começou a partir da premissa de que provavelmente existam relações entre indol e hormônios peptídicos pineal e o desenvolvimento somático, com a participação do complexo hipotálamo-hipófise. Fatores experimentais que foram objeto do presente trabalho influenciaram a dinâmica da massa corporal e o consumo de forragem, o que leva à ocorrência de algumas modificações estruturais importantes no nível da glândula pineal. A exposição dos indivíduos à luz contínua (Pinealectomia photic) leva ao aumento de massa corporal, mostrando o envolvimento da glândula pineal em reações neuroendócrino metabólicas, inclusive somáticas, que contribuem na manutenção do equilíbrio homeostático. O material biológico foi representado por um número de 50 indivíduos pertencentes a MAS Big híbrido 6, criados em solo, em uma ninhada permanente, o que poderia garantir a expansão da área de conhecimento a respeito da relação entre a tecnologia de criação, modulação de alguns parâmetros microclimáticos e performances de crescimento. Também foram realizadas por citometria e histometria determinações musculares.

[Cardiac arrest outside hospital: initial and subsequent cardiological management]. / Arrêt cardiaque extrahospitalier: prise en charge initiale puis en milieu cardiologique.

UNLABELLED: The prognosis of cardiac arrest outside hospital is directly related to the initial management. The aim of this work was to evaluate the characteristics of the initial and subsequent cardiological management of victims of cardiac arrest outside hospital with a retrospective analysis of data from the SAMU 35 (Emergency Medical Service, IIIe et Vilaine region) in the period April 1998 - April 2002. RESULTS: 533 non-traumatic cardiac arrests outside hospital were reported in 532 patients (average age 63 +/- 17, 73% male). The cardiac arrest occurred at home in 77% of cases. The initial cardiac rhythm documented was asystole in 63% of cases, ventricular fibrillation (VF) in 30% ventricular tachycardia (VT) in 1% and electromechanical dissociation in 6%. A cardiac aetiology was presumed in 294 (69%) of the 424 resuscitated patients. Among these, 22% (66/294) were admitted to coronary care units, 11% (31) left hospital alive, 8% (24) with no neurological sequelae. The survival rate for patients with cardiac arrest outside hospital in the presence of a witness and for whom the initial rhythm was VF or VT was 21%. The patient's age (<60 years)[OR: 1.05; CI 95%: 1.02-1.07; p < 0.001], rapid arrival of the SAMU (<10 min) [OR: 5.68; CI 95%: 1.42-22.7; p = 0.01] and resuscitation by the witness (OR: 8.26; CI 95%: 3.28-20.83; p < 0.001) were factors predictive of survival in a multivariate analysis. Coronary heart disease remains the principal cause of cardiac arrest in patients admitted to cardiology units (68%), with a recent coronary thrombosis shown in 40% of patients undergoing angiography (16/40). CONCLUSION: the prognosis of cardiac arrest outside hospital remains bleak, with a mortality of 90%. The survival rate is higher if the initial management is optimal, associated with bystander resuscitation and an immediate emergency service response allowing rapid defibrillation. Diagnosis and management of acute coronary syndrome in a cardiological setting must be integrated into the strategy.

[Intracerebral haematoma during a stress test]. / Hématome intracérébral au cours d'une épreuve d'effort intérêt médico-légal.

We report the case of a 64 year-old moderately hypertensive patient investigated for dyspnoea on exertion with no chest pain. After informing the patient, an ergometric test following a gentle protocol was performed, according to the French Society of Cardiology guidelines. At the peak of effort the patient developed a sudden left hemiplegia with a right capsulo-thalamic haematoma on cranial CT. No other case has been described and a literature search showed no relationship between physical effort and cerebral haematoma. Following an administrative tribunal enquiry, no medical fault was attributed regarding the indication and performing the test; no failure to inform could be established for a risk that was unknown at the time of the test.

[Sudden death disclosing abnormal origin of the left coronary vessel from the pulmonary artery trunk]. / Mort subite révélant une naissance anormale de la coronaire gauche à partir du tronc de l'artère pulmonaire.

Anomalous origin of the left coronary artery from the pulmonary artery is a rare congenital abnormality with a poor prognosis in the newborn. Adult forms are, therefore, very rare, presenting with angina, cardiac failure or sudden death. The authors report the case of a 41 year old woman who was asymptomatic until admitted as an emergency after ventricular fibrillation. Coronary angiography established the diagnosis. Despite the absence of reversible ischaemia on exercise myocardial scintigraphy, the patient underwent coronary bypass surgery of the left anterior descending artery with a pediculated internal mammary artery graft and closure of the left coronary ostium on the pulmonary artery. The echocardiographic abnormalities regressed within a few weeks. An automatic defibrillator was not implanted. The physiopathology of this rare cardiac lesion, the mechanisms of sudden death and the different techniques of surgical repair are discussed.

Numerical simulations of Raman spectra of guanine-cytosine Watson-Crick and protonated Hoogsteen base pairs.

Large changes in the Raman spectra of calf thymus DNA are observed upon lowering the pH. In order to gain a better insight into these effects, several simulations of the Raman spectra of the guanine-cytosine (GC) Watson-Crick and Hoogsteen base pairs are performed. By comparing the Raman bands of GC base pairs in calf thymus DNA at high and low pH with the theoretical simulations of GC base pairs, it is found that the intensity changes in the theoretical bands located between 400 and 1000 cm(-1) are small compared to the experimental ones. The behavior of the cytosine band at 1257 cm(-1) upon lowering the pH is not reproduced in the GC theoretical spectra. The bands located above 1300 cm(-1) in the theoretical spectra display intensity changes that are similar to those found for GC base pairs in calf thymus DNA spectra.

Raman microspectroscopic study of effects of Na(I) and Mg(II) ions on low pH induced DNA structural changes.

In this work a confocal Raman microspectrometer is used to investigate the influence of Na(+) and Mg(2+) ions on the DNA structural changes induced by low pH. Measurements are carried out on calf thymus DNA at neutral pH (7) and pH 3 in the presence of low and high concentrations of Na(+) and Mg(2+) ions, respectively. It is found that low concentrations of Na(+) ions do not protect DNA against binding of H(+). High concentrations of monovalent ions can prevent protonation of the DNA double helix. Our Raman spectra show that low concentrations of Mg(2+) ions partly protect DNA against protonation of cytosine (line at 1262 cm(-1)) but do not protect adenine and guanine N(7) against binding of H(+) (characteristic lines at 1304 and 1488 cm(-1), respectively). High concentrations of Mg(2+) can prevent protonation of cytosine and protonation of adenine (disruption of AT pairs). By analyzing the line at 1488 cm(-1), which obtains most of its intensity from a guanine vibration, high magnesium salt protect the N(7) of guanine against protonation. A high salt concentration can prevent protonation of guanine, cytosine, and adenine in DNA. Higher salt concentrations cause less DNA protonation than lower salt concentrations. Magnesium ions are found to be more effective in protecting DNA against binding of H(+) as compared with calcium ions presented in a previous study. Divalent metal cations (Mg(2+), Ca(2+)) are more effective in protecting DNA against protonation than monovalent ions (Na(+)).

Influence of Ca2+ cations on low pH-induced DNA structural transitions.

A confocal Raman microspectrometer was used to investigate the influence of Ca2+ cations on low pH-induced DNA structural changes. The effects of Ca2+ cations on the protonation mechanism of opening AT and changing the protonation of GC base pairs in DNA are discussed. Based on the observation that the midpoint of the transition of Watson-Crick GC base pairs to protonated GC base pairs lies at around pH 3 (analyzing the 681 cm(-1) line), measurements were carried out on calf thymus DNA at neutral pH and pH 3 in the presence of low and high concentrations of Ca2+ cations. Raman spectra show that low concentrations of Ca2+ cations partially protect DNA against protonation of cytosine (characteristic line at 1262 cm(-1)) and do not protect adenine (characteristic line at 1304 cm(-1)) and the N(7) of guanine (line at 1488 cm(-1)) against binding of H+. High Ca2+ concentrations can prevent protonation of cytosine and protonation of adenine (little disruption of AT pairs). Analyzing the line at 1488 cm(-1), which obtains most of its intensity from a guanine vibration, high salt was also found to protect the N(7) of guanine against protonation.

The expression of p53 protein in salivary gland carcinomas.

The p53 suppressor gene is the most frequently altered gene in solid human malignancies. It is located on the short arm of chromosome 17 in the region 17p13 and encodes a 53kD nuclear phosphoprotein containing 393 amino acids with specific DNA binding properties and a short life span. The wild p53 protein has been classified as a tumoral suppression gene with a determining role in controlling cellular proliferation and differentiation and can be inactivated through mutation in the protein sequence encoding the gene, leading to neoplastic transformation. In this study we analyzed the expression of p53 protein in a variety of salivary gland malignant tumors fixed in formalin and included in paraffin, using the method of immunohistochemical coloring with the anti-p53 DO-7 antibody. The evaluation of the immunoreactivity with p53 proved a significantly more intense coloring in salivary gland high-grade malignant tumors and the observed immunomarking of over 50% of the tumoral cells is correlated with the weak differentiation of the tumors, giving a predictive factor for the evolution of the disease.