Strain Modulation of Si Vacancy Emission from SiC Micro- and Nanoparticles.

Single-photon emitting point defects in semiconductors have emerged as strong candidates for future quantum technology devices. In the present work, we exploit crystalline particles to investigate relevant defect localizations, emission shifting, and waveguiding. Specifically, emission from 6H-SiC micro- and nanoparticles ranging from 100 nm to 5 µm in size is collected using cathodoluminescence (CL), and we monitor signals attributed to the Si vacancy (VSi) as a function of its location. Clear shifts in the emission wavelength are found for emitters localized in the particle center and at the edges. By comparing spatial CL maps with strain analysis carried out in transmission electron microscopy, we attribute the emission shifts to compressive strain of 2-3% along the particle a-direction. Thus, embedding VSi qubit defects within SiC nanoparticles offers an interesting and versatile opportunity to tune single-photon emission energies while simultaneously ensuring ease of addressability via a self-assembled SiC nanoparticle matrix.

Silicon surface passivation by PEDOT: PSS functionalized by SnO2 and TiO2 nanoparticles.

In this paper, we present a study of silicon surface passivation based on the use of spin-coated hybrid composite layers. We investigate both undoped poly(3,4-ethylenedioxythiophene)/poly-(styrenesulfonate) (PEDOT:PSS), as well as PEDOT:PSS functionalized with semiconducting oxide nanomaterials (TiO2 and SnO2). The hybrid compound was deposited at room temperature by spin coating-a potentially lower cost, lower processing time and higher throughput alternative compared with the commonly used vacuum-based techniques. Photoluminescence imaging was used to characterize the electronic properties of the Si/PEDOT:PSS interface. Good surface passivation was achieved by PEDOT:PSS functionalized by semiconducting oxides. We show that control of the concentration of semiconducting oxide nanoparticles in the polymer is crucial in determining the passivation performance. A charge carrier lifetime of about 275 µs has been achieved when using SnO2 nanoparticles at a concentration of 0.5 wt.% as a filler in the composite film. X-ray diffraction (XRD), scanning electron microscopy, high resolution transmission electron microscopy (HRTEM), energy dispersive x-ray in an SEM, and µ-Raman spectroscopy have been used for the morphological, chemical and structural characterization. Finally, a simple model of a photovoltaic device based on PEDOT:PSS functionalized with semiconducting oxide nanoparticles has been fabricated and electrically characterized.

[Giant retroperitoneal hydatid cyst in a traveller]. / Kyste hydatique rétropéritonéal géant chez un voyageur.

INTRODUCTION: Giant hydatid cyst located in the retroperitoneal space is rare. The purpose of this report is to present a case cured by surgery in an adult traveller. CASE REPORT: In August 2009, a 67-year-old female who traveled frequently to Lebanon was admitted for assessment of a giant retroperitoneal hydatid cyst discovered coincidentally following palpation of an abdominal mass in 1997. From 1966 to 1975, the patient had undergone several surgical procedures for pulmonary and hepatic hydatidosis, complicated by vomica and anaphylactic shock. In 1997, computed tomography showed that the retroperitoneal cyst measured 100 mm at the widest point. At that time, the patient refused to undergo further surgery and was treated medically using albendazole initially in association with praziquantel. In 2009, the cyst had expanded to 180 mm at the widest point and the patient finally consented to perikystectomy. Excision was total and recovery was uneventful. Histology examination confirmed the viability of the cyst. Follow-up examination at 12 months indicated no relapse. COMMENTS: The retroperitoneal space is a rare location for hydatidosis. Occurrence in this location is generally primary. In case of discovery of a liquid-filled retroperitoneal mass, a history of travel to an endemic area for hydatid disease should be elicited. Diagnosis relies on radiological findings and positive serology. Since retroperitoneal cysts are often giant, they respond poorly to medical treatment. Similarly radiological treatment is difficult due to retroperitoneal location. Surgery, preferably perikystectomy, is the treatment of choice.

Clinical significance of epithelial-mesenchymal transition-related markers expression in the micrometastatic sentinel lymph node of NSCLC.

OBJECTIVES: Metastatic lymph node affectation is the main prognostic factor in localised lung cancer. However, the pathological study of lymph nodes reveals tumour relapse for 20% of patients after oncological curative surgery. Recently, EMT (epithelial-mesenchymal transition) has been established as one of the main factors related to lymphatic dissemination and metastasis. This study evaluated the prognostic value of EMT-related gene expression in micrometastatic sentinel lymph nodes (SLN) of non-small cell lung cancer (NSCLC) patients. METHODS: The presence of genes CDH1, CDH2, VIM, TWIST1, SNAI1, SNAI2, ZEB1, and ZEB2 in mRNA was analysed in tumours and in the SLN of NSCLC patients for whom surgery was planned for treatment. The significant association between the expression level of EMT-related markers and patients' clinicopathological characteristics and relapse was assessed. RESULTS: Of the 96 patients, 56 (58.33%) presented molecular micrometastasis in SLN, which showed higher CDH1, CDH2, and VIM expressions than non-micrometastatic ones. An association linking a low CDH1/CDH2 ratio in SLN with molecular micrometastasis, adenocarcinoma, and non-smoking patients was found. The multivariate Cox regression analysis proved the prognostic accuracy of the CDH1/CDH2 ratio in SLN. CONCLUSIONS: The molecular EMT status of SLN could be used as an independent prognosis predictor in early stage NSLCL patients, and as a new tool to better stratify and predict patient outcomes.

Transcriptomic analysis of polyamine-related genes and polyamine levels in placenta, yolk sac and fetus during the second half of mouse pregnancy.

In mammals, polyamines are essential for the maintenance of cell growth. Although early studies reported the highest values of mammalian ornithine decarboxylase (ODC) activity, a key enzyme in polyamine biosynthesis, in rodent placenta, the role of this enzyme in the second half of rodent pregnancy is still controversial. In order to get new insights on polyamine metabolism during this period of pregnancy, we studied polyamine levels, ODC expression and activity and transcript profile of different polyamine-related genes in mouse placenta, fetus and yolk sac. Results indicated that ODC activity and protein levels were higher in placenta than in fetus and yolk sac, especially in the labyrinth, although no correlation between ODC activity and polyamine levels were observed. The half-life of placental ODC ( approximately 190 min) was also higher than the fetal one ( approximately 24 min). Messenger RNAs of all biosynthetic and retroconversion enzymes of polyamine metabolism were present in the three gestational compartments analyzed, as well as those of antizymes 1 and 2 and antizyme inhibitor 1. However, no expression of antizyme 3 and antizyme inhibitor 2 was detected. The catabolic enzyme diamine oxidase was expressed only in the maternal part of placenta but not in the fetal part or in the fetus. The expansion of polyamine pools in the fetus was markedly higher than in placenta, in spite of its lower biosynthetic activity. Our results suggest that the elevated polyamine biosynthetic activity of mouse placenta is required to satisfy the high demand of polyamines required by the growing fetus, during the later period of pregnancy.

Electrical properties of nanostructured tin oxide surfaces produced by thermal treatments.

Sintering SnO2 powder in air or under an oxygen atmosphere at different temperatures, leads to polycrystalline samples with nanostructured surface as revealed by atomic force microscopy (AFM). The thermal treatments are also responsible for the variation of the surface electrical properties, as studied by scanning spreading resistance microscopy (SSRM) and scanning tunnelling microscopy and spectroscopy (STM-STS). The surface presents a p-conductance, contrary to the n-type characteristic of the bulk, and a band gap lower than the bulk band gap (3.6 eV). The electrical behaviour at the grain boundaries and the role of oxygen are discussed. X-ray photoelectron spectroscopy (XPS) results show a higher presence of oxygen at the boundaries, which generates a shift of the Fermi level position (E(F)-E(V)) towards lower energies.

Growth and luminescence of N doped TiO2 nanowires.

Titanium oxide nanowires have been grown by thermal treatment of pressed TiN powder under argon or N2 flow. It has been found that two-step treatments at two different temperatures, 400 degrees C and 800 degrees C, lead to the growth of nanowires all over the sample surface. The nanowires are of single crystalline rutile structure. Energy dispersive X-ray spectroscopy and photoelectron spectroscopy measurements show that the oxide nanostructures contain N from the starting nitride. The mechanism of N incorporation into the oxide and its possible effect on the luminescence are discussed.

Cathodoluminescence study of semiconductor oxide micro- and nanostructures grown by vapor deposition.

Nano- and microstructures of SnO(2), In(2)O(3) and ZnO have been grown during thermal treatment of compacted powders under argon flow. Indium-doped SnO(2) tube-shaped structures with rectangular cross-section are obtained by adding a fraction of In(2)O(3) to the starting SnO(2) powder. In-rich nanoislands were found to grow on some edges of the tubes. ZnO nanostructures doped with Sn or Eu were grown by adding SnO(2) and Eu(2)O(3) powder, respectively, to the ZnO precursor powder. All the samples have been characterized by the emissive and cathodoluminescence (CL) modes of scanning electron microscopy. CL images from SnO(2):In and In(2)O(3):Sn tubes and islands show a higher emission from the Sn-rich structures related to oxygen deficiency. CL of doped ZnO enables to detect the presence of dopant in specific regions or structures. CL appears to be a useful technique to study optical and electronic properties of semiconductor oxide nanostructures.

[Late mediastinal metastasis of Ewing's sarcoma of tibia]. / Métastase médiastinale tardive d'un sarcome d'Ewing du tibia.

Peripheral neuroectodermal tumors constitute a large spectrum of small round cell tumors among which Ewing's sarcoma is the most undifferentiated type. They are rare tumors which often concern young people and generally occur in bone tissue. Their metastatic potential is high, generally early, and rarely after five years. We report the case of a 45-year-old woman who presented a mediastinal metastasis eight years after the primitive tumor of tibia. The diagnosis was made on small core biopsies obtained by CT punction, and was based on morphologic analysis, immunohistochemistry, and confirmed by molecular biology. The presence of metastasis is the main prognostic factor. Despite therapeutic progress, the global survival rate of metastatic patients is still poor.

Hypereosinophilia and epigastralgia after visiting Tunisia: a rare differential diagnosis of helminthiases.

Causes of hypereosinophilia among travelers returning from North Africa are dominated by helminth infections, especially when associated with gastrointestinal signs. Non-infectious causes must nonetheless be investigated after negative microbiological assessment and failure of a broad empiric antiparasite treatment. We report the case of a young man with epigastralgia and major weight loss since a stay in Tunisia. Empiric treatment with albendazole was not successful. Eosinophilic gastroenteritis was diagnosed and resolved under corticosteroid treatment.

Topography of the sentinel node according to the affected lobe in lung cancer.

PURPOSE: The objective of this study is to describe the anatomic location of the sentinel lymph node (SLN) of patients with lung carcinoma and to analyze its relationship with the characteristics of the tumor. PATIENTS AND METHODS: 98 Stage I lung cancer patients were included in the study. SLN was marked just after performing the thoracotomy by injecting peritumorally 0.25 mCi of nanocolloid of albumin (Nanocol1) labeled with Tc-99 m in 0.3 ml, and later, it was resected. For SLN micrometastasis analysis, CEACAM5, BPIFA1, and CK7 gene expression at mRNA level was studied. Possible relation between tumor characteristics and SLN location was analyzed. RESULTS: While most of the SLN were located in hilar area, we find a significantly higher number of SLN located in mediastinal stations when the lesion is in the left upper lobe (LUL). This difference disappears in the group of SLN with a positive result in the micrometastasis study. Regarding tumor size, squamous tumors and tumors located in the left lower lobe (LLL) were found significantly larger. CONCLUSION: The location of the SLN in patients with stage I lung cancer is predominantly hilar, being less consistent in the left hemithorax. The tumor size or histological type is not variables that affect this distribution. The distribution of SLNs with a positive result in the analysis of micrometastasis suggests further spread to the hilar areas when the lesion is in the LUL and to the mediastinal zones when it is in the LLL.

Agentes hemostáticos tópicos de uso quirúrgico / Topical hemostatic agents for surgical use

Introducción: La morbilidad, mortalidad y costes tras la cirugía se hallan influenciados en gran medida por la pérdida hemática o hemorragia y las consecuencias derivadas de la misma. Para controlar la hemorragia, es frecuente el uso de agentes hemostáticos tópicos en combinación o en adyuvancia a otras técnicas hemostáticas, cuando éstas resultan ineficaces o impracticables. Material y métodos: Se realizó una revisión sistemática en Cochrane y MEDLINE desde el año 2000 a 2017 para identificar las publicaciones relacionadas con el uso de hemostáticos pasivos, activos y sellantes en comparación con otros agentes hemostáticos en todos los tipos de intervenciones quirúrgicas. Resultados: Se seleccionaron 20 ensayos clínicos. La variable principal de eficacia en el 95% fue el tiempo hasta la hemostasia y en el 5% la disminución del sangrado. Las intervenciones quirúrgicas más frecuentes fueron; cirugía hepática (30%), vascular (20%), cardíaca (10%), espinal (10%), general (5%), plástica (5%), y otros tipos de cirugía (20%).Los estudios se dividieron en 7 grupos, en función del tipo de agente hemostático a estudio y el comparador: a) hemostáticos mixtos versus pasivos (10%), b) sellantes de fibrina versus hemostáticos activos (5%), c) sellantes de fibrina versus hemostáticos pasivos (50%), d) hemostáticos mixtos entre sí (15%), e) sellantes de fibrina entre sí (5%), f) hemostáticos pasivos entre sí (5%), g) hemostáticos activos entre sí (10%).Conclusiones: Los hemostáticos activos, mixtos y sellantes de fibrina demuestran superioridad frente a los pasivos en términos de eficacia clínica, con un coste superior y un perfil de efectos adversos similar. (AU)

Introduction: Morbidity, mortality, and costs after surgery are greatly influenced by blood loss or bleeding and the consequences of it.To control bleeding, the use of topical hemostatic agents in combination or adjuvant to other hemostatic techniques is frequent, when these are ineffective or impractical.Method: A systematic review was conducted in Cochrane and PubMed from 2000 to 2017 to identify publications related to the use of passive, active and sealant hemostatics compared to other hemostatic agents in all types of surgical interventions.Results: Twenty clinical trials were selected. The main variable of efficacy in 95% was the time to hemostasis and in 5% the decrease in bleeding.The most frequent surgical interventions were; liver surgery (30%), vascular (20%), cardiac (10%), spinal (10%), general (5%), plastic (5%), and other types of surgery (20%).The studies were divided into 7 groups, depending on the type of hemostatic agent under study and the comparator: a) mixed hemostatic versus passive (10%), b) fibrin sealants versus active hemostatic agents (5%), c) fibrin sealants versus passive hemostatic (50%), d) mixed hemostatic with each other (15%), e) fibrin sealants with each other (5%), f) passive hemostatic with each other (5%), g) active hemostatic with each other (10%).Conclusions: Active and mixed hemostatics and fibrin sealants showed superiority over the passive hemostatics in terms of clinical efficacy, with a higher cost and a similar profile of side effects. (AU)

Prognostic value of ERCC1, RRM1, BRCA1 and SETDB1 in early stage of non-small cell lung cancer.

INTRODUCTION: Nowadays, 40 % of early-stage NSCLC patients relapse in the 2 years following resection, suggesting a mis-staging in this group of patients who are not receiving adjuvant chemotherapy. Although different biomarkers, such as ERCC1, RRM1 and BRCA1 have been found to present prognostic value in advanced NSCLC patients, in early-stage NSCLC patients its relevance remains unclear. Moreover, SETDB1 has been recently proposed as a bona fide oncogene in lung tumourigenesis and related with metastasis. The aim of the present study was to analyze the prognostic value of ERCC1, RRM1, BRCA1 and SETDB1 expression levels in NSCLC patients at stage I. PATIENTS AND METHODS: ERCC1, RRM1, BRCA1 and SETDB1 expression at mRNA level was analyzed by real-time quantitative RT-PCR in fresh-frozen tumor and normal adjacent lung tissue samples from 64 stage I NSCLC patients. Later, significant association between gene expression levels, clinicopathological characteristics and patient's disease-free survival was assessed. RESULTS: We did not find any statistically significant correlation between gene expression and gender, age, histological type or smoking status. Univariate followed by multivariate Cox analysis showed that higher levels of BRCA1 and SETDB1 expression were significantly associated with shorter disease-free survival in stage I NSCLC patients. CONCLUSION: Our study finds that ERCC1 and RRM1 are not independent prognostic factors of recurrence in stage I NSCLC patients. By contrast, BRCA1 and SETDB1 stand out as the most significant prognostic markers in this group of patients, appearing as promising tools to predict tumor recurrence in early-stage NSCLC patients.

Antiandrogenic effect of RU-486 in the mouse kidney.

RU-486 (mifepristone) is a synthetic steroid with potent antiprogesterone and antiglucocorticoid activity, that is currently used as a contraceptive agent. In the present work we have evaluated the antiandrogenic effect of this compound on mouse kidney, a very well known extragenital model of androgen action by studying the effect of RU-486 on renal parameters that depend on androgens, such as renal ornithine decarboxylase (ODC) activity and kidney hypertrophy, as well as the inhibitory action of mifepristone on the induction of renal ODC and kidney hypertrophy elicited by testosterone treatment in female mice and in castrated male. The results showed that: (1) 48 hr after treatment of male mice with of RU-486 (50 mg/kg, four injections) renal ODC activity decreased from 3.381 +/- 490 nmol CO2/h.g to 605 +/- 163 (SD, n = 5); (2) in female mice or orchidectomized male mice, RU-486 also inhibited the renal ODC induction elicited by exogenous administration of testosterone propionate (TP), the magnitude of the inhibition was dependent on the doses of TP and RU-486 used. While RU-486 at a dose of 25 mg/kg inhibited more than 80% ODC induction produced by treatment with 5 mg/kg TP, the same dose did not significantly affect ODC when the dose of TP was increased up to 100 mg/kg. Higher concentration of RU-486 (200 mg/kg) clearly inhibited the increase in ODC produced by treatment with TP 100 mg/kg; (3) RU-486 was more effective in blocking the anabolic effects produced by stanozolol, a steroidal anabolizing agent, than those produced by testosterone; and (4) RU-486 was less effective than the nonsteroidal antiandrogen flutamide in inhibiting renal ODC activity in male mice. Our results clearly indicate that RU-486 possesses moderate antiandrogenic activity in mouse kidney. The possibility that RU-486 may have similar effects in man should be considered when using this drug.

Hypokalemia decreases testosterone production in male mice by altering luteinizing hormone secretion.

Potassium deficiency produced by feeding mice a low potassium diet caused a marked decrease in plasma and testicular testosterone concentrations and a concomitant fall in the weight of seminal vesicles and in renal ornithine decarboxylase activity. All of these parameters were rapidly restored when potassium supply was normalized. Immunocytochemical analysis of gonadotropes and plasma LH values suggested that the pulsatile liberation of LH by the pituitary was impaired in the potassium-deficient male mice. Because the synthesis of testosterone in the potassium-deficient mice was stimulated by exogenous LH, hCG, or GnRH, one can conclude that alteration of the transcellular potassium gradient could affect the regulation of the hypothalamo-hypophyseal-testicular axis by affecting the pulsatile release of GnRH. Our results showing that the stimulation of LH secretion after castration was similar in control and potassium-deficient male mice suggest that a testicular factor(s) different from testosterone could be implicated in the abnormal regulation of LH secretion in potassium-deficient mice. We conclude that plasma potassium concentration is an important factor in the regulation of gonadotropin secretion and testicular functions.

Potassium regulates plasma testosterone and renal ornithine decarboxylase in mice.

Potassium deficiency produced different effects in the kidney of male or female mice. While in female, potassium deficiency caused a marked renal hypertrophy with no significant changes in testosterone-regulated enzymes, such as ornithine decarboxylase and beta-glucuronidase, in the male the same treatment provoked a marked fall of these enzymes owing to a dramatic decrease in plasma testosterone. Potassium replenishment restored plasma testosterone and renal enzymatic activities. These results show for the first time, that potassium modulates circulating testosterone and suggest that this cation could exert an important regulatory role in controlling androgen actions.

Influence of dietary arginine on the anabolic effects of androgens.

Feeding mice an arginine-deficient diet decreased plasma concentrations of arginine, citrulline and ornithine in the females and arginine in the males, abolishing the sexual dimorphic pattern of these amino acids found in mice fed the standard diet. In addition, the restriction of dietary arginine produced a marked decrease in body and renal weights as well as in the activity of renal ornithine decarboxylase, decreases that were gender dependent since they were observed exclusively in males. The fact that these changes were not associated with the decrease in the circulating levels of testosterone and that the dietary arginine restriction prevented the body weight gain induced by testosterone treatment of female mice fed the standard diet indicates that dietary arginine is required for the anabolic action of androgens. Moreover, under certain conditions that could compromise the renal synthesis of arginine, as in the compensatory renal hypertrophy that follows unilateral nephrectomy, the myotrophic effect of testosterone was transiently impaired. The results also revealed that arginine deficiency produced an opposite effect in the expression of IGF-I and IGF-binding protein 1 in the liver and kidney. Taken together, our results indicate that dietary arginine may be relevant to the anabolic action of testosterone, and suggest that this effect may be mediated by changes in the insulin-like growth factor system.

The effect of hyperthermia on ornithine decarboxylase activity in different rat tissues.

Hyperthermia produced a decrease of ornithine decarboxylase activity in different tissues of adult rats. The fall in ornithine decarboxylase was dependent on time of exposure and temperature. The decay of ornithine decarboxylase activity in liver, brain, kidney, heart, spleen and testes was rather similar. The t1/2 for liver ornithine decarboxylase determined by the hyperthermic treatment (40 degrees ambient temperature) was 20 min. Ornithine decarboxylase activity was recovered in all tissues exposed to the hyperthermic shock after a period of 4 hours, although the degree of recovery was dependent on the type of tissue. The effect that hyperthermia produces on ornithine decarboxylase activity in rats could be related to an inhibition in the synthesis of active enzyme rather than to a specific degradation or inactivation of ornithine decarboxylase molecule.

Thermotherapy for Harding-Passey melanoma: light and electron microscopic study.

The changes of implanted Harding-Passey melanoma in C57Bl/6J mice following treatment with wholebody hyperthermia were studied. The treated tumours showed a progressive growth delay, cellular and architectural irregularities as well as cell injury characteristics. The presence of distended and irregular blood vessels, the peripheral localization of the melanosomes and the melanosome complexes were constant.

Hyperthermia and the neurotoxicity of exogenous glutamate in infant rats.

A substantial elevation of the excitatory neurotransmitter glutamate can be produced in the brain of 3-day old rats, either after subcutaneous injection of monosodium glutamate (4 mg/g), or by hyperthermic treatment (40 degrees C, 3 h). In the glutamate-treated animals a large increase in the GABA levels has also been observed while the elevation of this amino acid in the hyperthermic animals is insignificant. Although the magnitude of the increase of glutamate in both cases is rather similar, in the hyperthermic animals no cerebral lesions such as those produced in the glutamate-treated animals could be observed. Therefore, high extracellular levels of glutamate seem to be required to produce the variety of neurotoxic effects related to this excitatory amino acid.