Graphite-oxide hybrid multi-degree of freedom resonator metamaterial for broadband sound absorption.

Low frequency broadband sound absorption for thin structures is still a great challenge. A new concept of a stackable hybrid resonator metamaterial is proposed which exhibits super broadband low-frequency sound absorption. The proposed metamaterial is based on micrometric scale thickness Graphene Oxide (GO) embedded in a stacked structure or used as external skin in a designed honeycomb (HC) structure. The stackable nature of the proposed structure allows the GO-HC cores to be embedded within micro-perforated panels (MPP) providing enhanced stiffness/strength to the structure and high absorption characteristics. We demonstrate how the exploitation of the GO elastic and mass properties result in multiple hybrid structural-acoustic resonances. These resonances are tailored to occur in a frequency range of interest by the theoretical calculation of the sound absorption coefficient. The theoretical model combines the mutual interaction between the structural dynamic of the GO foil and acoustic higher modes of the HC core cell as well as stacked MPP-HC/GO-HC cores. The result is a multi-degree of freedom hybrid resonator which provides subwavelength scale broadband sound absorption in low frequency range between 300 and 2500 Hz.

Mercury and selenium concentrations in marine shrimps of NW Mexico: health risk assessment.

We determined total Hg and Se contents of hepatopancreas, exoskeleton, and muscle, and the Se:Hg molar ratios in the muscle of shrimps Farfantepenaeus californiensis and Litopenaeus stylirostris caught in NE Pacific Mexican waters. Total Hg mean values in muscle, hepatopancreas, and exoskeleton were 0.31 ± 0.26, 0.28 ± 0.29, and 0.24 ± 0.06 µg g-1, and 0.46 ± 0.46, 0.41 ± .034, and 0.24 ± 0.06 µg g-1 for F. californiensis and L. stylirostris, respectively. In all tissues, the mean concentrations of Se tended to be close to one order of magnitude higher than the respective Hg values. In F. californiensis, the hepatopancreas of the larger commercial size had significantly (p < 0.05) higher Hg content than smaller sizes, but correlations size-Hg concentration calculated for each tissue of either species were not significant. The Hg content of the muscle of all commercial sizes of both species was lower than the permissible limit and their Se:Hg ratios in all sizes were higher than 1, indicating low risk for human consumption.

Changes in metal contents in shrimp cultured in NW Mexico (2000-2010).

This study shows the concentrations of Cd, Cu, Pb, and Zn in the muscle and hepatopancreas of Pacific white shrimps, Litopenaeus vannamei, cultured during 2010 in 26 commercial farms of the three main producer states of the Mexican NW, Sonora, Sinaloa, and Nayarit and compares the results to those obtained in 2000 using samples collected in16 farms of the same states. No significant changes were detected in Cd concentrations, but the 2010 Zn levels were significantly higher in all states in the hepatopancreas and in Sinaloa in the case of the muscle. Cu showed a tendency to higher hepatopancreas values in 2010, but differences were significant only in Sonora and for the global mean value. In contrast, Pb was one order of magnitude lower in both organs in 2010, possibly because of the almost 15 years since leaded gasoline was discontinued in Mexico.

Mediastinal parathyroid adenoma: a case report.

Ectopic parathyroid adenomas represent a diagnostic challenge, since they are quite rare in clinical practice. We present a case of a 61 years old man with symptomatic hypercalcemia due to an ectopic parathyroid adenoma in the upper-anterior mediastinum that was not localized by the scintigraphy. Ultrasonography identified a nodule on the left upper-superior lobe of the thyroid gland, consistent with a parathyroid adenoma; scintigraphy showed two focuses of abnormal tracer uptake, one on the left upper-superior lobe of the gland and the other on the right inferior lobe of the gland. Patient underwent surgery to remove the adenoma on the left side, but postoperatively PTH and serum calcium level were still elevated. CT scan showed a mass of 27 x 22 mm in the upper anterior mediastinum, in front of the right emisoma of D2. The final surgery allowed us to remove the adenoma with a laterocervical approach. The histopathology was consistent with parathyroid adenoma.

A novel approach to study oxidative stress in thyroid diseases: a preliminary study.

BACKGROUND AND OBJECTIVES: Recently, several Authors have emphasized the relationship between oxidative stress and thyroid tumors. Several methods have been proposed in the literature for the measurement of oxidative stress in human tissues, although the high reactivity and short half life of reactive oxygen and nitrogen species make difficult their direct determination. Here we propose a novel approach for the determination of oxidative stress in human tissues, taking into account the relationship between free radicals and thyroid diseases. MATERIALS AND METHODS: Our goal in this preliminary study, was to demonstrate the opportunity to use the coupling of the EPR-spin trapping technique with the hydroxylamine 1-hydroxy-3-carboxy-pyrrolidine, to detect oxidative stress in the human blood of patients with thyroid disease. RESULTS: Our preliminary findings confirm that this is a sensible, precise and valid method to study the oxidative stress and encourage us to continue the project. CONCLUSIONS: Our next goal will be to enroll patients affected by different thyroid diseases and to study the effect of some antioxidants in the management of the disease. This will allow to better understand the pathological path that binds the formation of reactive oxidizing species to the thyroid cancer and eventually to take into account the antioxidant therapy, as a possible additional "therapeutic weapon".

Metal contents of four commercial fish species of NW Mexico.

The metal contents in tissues of fish species: M. cephalus, Diapterus sp., Scomberomorus sierra and Oreochromis aureus, were determined in order to evaluate if their consumption might become a health risk. The liver and gills of M. cephalus and Diapterus sp. had the highest values of Cu, Fe and Pb. In the muscle, there were no interspecific differences in the Cd, Cu and Pb contents (0.27-0.32, 0.96-1.30 and 2.12-2.80 microg/g dw, respectively). Cd and Pb may be of concern, since their mean contents in the edible muscle of the four species are higher than the limits of the European Community.

Effect of desquamative gingivitis on periodontal status: a pilot study.

OBJECTIVE: Desquamative gingivitis (DG) represents the gingival manifestation associated with several mucocutaneous disorders and systemic conditions. Little is known of whether or not DG could influence the onset or progression of plaque-related periodontitis. In this study, the potential impact of DG on plaque-related attachment loss and pocket formation has been evaluated. METHODS: A cross-sectional evaluation of 12 patients with DG [eight oral lichen planus (OLP), four mucous membrane pemphigoid (MMP)], never treated for DG lesions or plaque-related periodontitis, was carried out. Probing depth (PD), clinical attachment loss (CAL), full-mouth plaque (FMPS), and bleeding (FMBS) scores were evaluated at six sites per tooth. Clinical parameters of sites with DG lesions were compared with that of DG unaffected sites. RESULTS: Median PD and CAL, as well as FMPS and FMBS, were not significantly different (P > 0.05 Mann-Whitney test) for both OLP and MMP patients. However, a negative association between DG lesions and PD < 4 mm (OLP: OR = 0.26; MMP: OR = 0.47), and a positive association with PD 4-6 mm (OLP: OR = 3.76; MMP: OR = 2.68) and with PD > 6 mm (only for OLP: OR = 3.83) were found to be significant. CONCLUSIONS: The potential interference between DG lesions and periodontitis needs further prospective investigation; nonetheless, a higher level of attention might be prudent.

Toxicity of metal mixtures to the Pacific white shrimp Litopenaeus vannamei postlarvae.

According to the literature, the safe level of a toxic substance for any given organism may be calculated from its median lethal concentration multiplied by a suitable application factor (AF: usually 0.1 and 0.01). The medial lethal concentrations for Litopenaeus vannamei postlarvae exposed to the mixtures in equitoxic proportions of Cd-Hg, Hg-Zn and Hg-Pb were close to one order of magnitude lower than the values calculated from individual toxicity tests, indicating a synergistic effect, while the mixture Cd-Zn showed an antagonistic effect. Exposure to the mixture of Cu, Fe, Mn, Zn, Cd, Hg and Pb caused 63.3% and 100% mortality after 21 and 13 days for 0.05 and 0.1 AF, showing that environmental safe concentrations of toxicants should not be calculated from individual toxicity tests.

Cadmium, copper, lead and zinc contents of the mangrove oyster, Crassostrea corteziensis, of seven coastal lagoons of NW Mexico.

The ranges of concentrations of Cd, Cu, Pb and Zn of the soft tissues of C. corteziensis collected in seven coastal lagoons of NW Mexico were 1.55-7.45, 17.50-166.36, 4.13-9.49 and 245.34-2,304.12 microg/g (dry weight), respectively. Their distributions were not consistent and there were no seasonal trends, indicating different point sources of the metals in each lagoon. The mean Cd and Pb concentrations were 5.34 and 6.30 microg/g (dry weight), which are higher than the values indicative of polluted areas. Our data indicate that only the levels of Cd are a possible health risk in six of these lagoons, and only in the case of regular local consumers. In one, Cu and Zn reach levels of concern.

Metal content of the gulf of California blue shrimp Litopenaeus stylirostris (Stimpson).

The blue shrimp Litopenaeus stylirostris is the main target species of the Gulf of California shrimping fleet, and its heavy metal content might be of concern for human health because of the increasing contamination of the Gulf. The Cd content of shrimp caught by commercial trawlers ranged from 0.38 to 1.05 microg/g and the mean value was significantly lower in the northern fishing grounds. Pb ranged from 3.19 to 9.59 microg/g and was significantly higher in the northern area. There were no significant geographic difference in the case of Cu and Zn (respective means = 25.4 and 57.8 microg/g). The mean values of all metals show that none is of particular concern for human health.

Uso de infliximab en pacientes de un centro reumatologico / Use of infliximab in patients of a rheumatologic center

The objective of this study was to obtain post-marketing information about the use of infliximab in an ambulatory setting. We studied--retrospectively and prospectively--the case records of patients with rheumatoid arthritis (n=37), psoriatic arthritis (n=5), mixed connective tissue disease (n=1), and ankylosing spondylitis (n=2) who received infliximab (3 mg/kg) from August 2000 to January 2003. Descriptive values were given as percentage, mean or median, and standard deviation or interquartile range. Wilcoxon test was used for paired analysis of pre/post doses of corticosteroids, non-steroidal anti-inflammatory drugs, and methotrexate therapy. A p value < or = 0.05 was considered significant. Forty-five patients were included. A total of 207 infusions were administered. In 4 patients the treatment was permanently discontinued due to severe back pain during the infusion (2 cases) and serious anaphylactic reactions (2 cases). Other adverse reactions occurring during infusions were mild and successfully managed with standard treatment. A case of staphylococcal septic arthritis resolved with standard antibiotic treatment. No patient had evidence of active tuberculosis. One patient with rheumatoid arthritis and chronic renal insufficiency, received treatment with infliximab 1.9 mg/kg, every 30 days, with no changes in renal function. Due to improvement of symptoms, 14/39 (35.9%) patients could decrease the doses of corticosteroids, 15/43 (34.8%) decreased the doses of antiinflammatory drugs and 12/34 (35.3%) decreased methotrexate dosage. Although some questions remain to be elucidated, this case series shows the drug safety profile, the possibility to reduce concomitant drug doses, as well as individual approaches for situations where there are not yet guidelines available, so that rheumatologists have to make decisions based on clinical needs.

El objetivo de este estudio fue obtener informacion postmarketing sobre el uso de infliximab en un centro reumatologico de atencion ambulatoria. Se realizo un analisis retrospectivo y prospectivo de las historias clinicas de pacientes con diagnostico de artritis reumatoidea (n=37), artritis psoriasica (n=5),enfermedad mixta del tejido conectivo (n=1) y espondilitis anquilosante (n=2) que recibieron infliximab (3 mg/kg) desde agosto de 2000 a junio de 2003. El analisis descriptivo se realizo con porcentajes, media o medianay desviacion estandar o intervalo intercuartilo. La prueba de Wilcoxon se utilizo para el analisis apareado dedosis de antiinflamatorios no esteroideos y metotrexato, anterior y posterior a la administracion de infliximab. Se consideraron significativos valores de p < o = 0.05. Se incluyeron 45 pacientes a los que se les administraron un total de 207 infusiones. En 2 pacientes el infliximab se discontinuó debido a lumbalgia severa durante la infusion y en otros 2 por anafilaxia intrainfusional. Otras reacciones adversas ocurridas durante las infusiones fueron moderadas y respondieron adecuadamente al tratamiento estandar. Se presento un caso de artritis septica de rodilla por estafilococos. Un caso de artritis reumatoidea con insuficiencia renal compensada recibio infliximab en dosis de 1.9 mg/kg cada 30 dias, sin cambios en la funcion renal. Al momento, ningun paciente ha desarrollado tuberculosis activa. Debido a la mejoria clinica, se redujo la dosis de corticoides en 14/39 (35.9%) pacientes, de antiinflamatorios no esteroideos en 15/43 (34.8%) y de metotrexato en 12/34 (35.3%). En estaserie de casos se muestra el perfil de seguridad de infliximab, la posibilidad de reducir la dosis de drogas concomitantes,asi como algunos enfoques individuales sobre situaciones para las cuales no disponemos de guias basadas en la evidencia medica, y en las que los reumatologos debemos tomar decisiones segun las necesidades clinicas.

Uso de infliximab en pacientes de un centro reumatologico / Use of infliximab in patients of a rheumatologic center

The objective of this study was to obtain post-marketing information about the use of infliximab in an ambulatory setting. We studied--retrospectively and prospectively--the case records of patients with rheumatoid arthritis (n=37), psoriatic arthritis (n=5), mixed connective tissue disease (n=1), and ankylosing spondylitis (n=2) who received infliximab (3 mg/kg) from August 2000 to January 2003. Descriptive values were given as percentage, mean or median, and standard deviation or interquartile range. Wilcoxon test was used for paired analysis of pre/post doses of corticosteroids, non-steroidal anti-inflammatory drugs, and methotrexate therapy. A p value < or = 0.05 was considered significant. Forty-five patients were included. A total of 207 infusions were administered. In 4 patients the treatment was permanently discontinued due to severe back pain during the infusion (2 cases) and serious anaphylactic reactions (2 cases). Other adverse reactions occurring during infusions were mild and successfully managed with standard treatment. A case of staphylococcal septic arthritis resolved with standard antibiotic treatment. No patient had evidence of active tuberculosis. One patient with rheumatoid arthritis and chronic renal insufficiency, received treatment with infliximab 1.9 mg/kg, every 30 days, with no changes in renal function. Due to improvement of symptoms, 14/39 (35.9%) patients could decrease the doses of corticosteroids, 15/43 (34.8%) decreased the doses of antiinflammatory drugs and 12/34 (35.3%) decreased methotrexate dosage. Although some questions remain to be elucidated, this case series shows the drug safety profile, the possibility to reduce concomitant drug doses, as well as individual approaches for situations where there are not yet guidelines available, so that rheumatologists have to make decisions based on clinical needs.(AU)

El objetivo de este estudio fue obtener informacion postmarketing sobre el uso de infliximab en un centro reumatologico de atencion ambulatoria. Se realizo un analisis retrospectivo y prospectivo de las historias clinicas de pacientes con diagnostico de artritis reumatoidea (n=37), artritis psoriasica (n=5),enfermedad mixta del tejido conectivo (n=1) y espondilitis anquilosante (n=2) que recibieron infliximab (3 mg/kg) desde agosto de 2000 a junio de 2003. El analisis descriptivo se realizo con porcentajes, media o medianay desviacion estandar o intervalo intercuartilo. La prueba de Wilcoxon se utilizo para el analisis apareado dedosis de antiinflamatorios no esteroideos y metotrexato, anterior y posterior a la administracion de infliximab. Se consideraron significativos valores de p < o = 0.05. Se incluyeron 45 pacientes a los que se les administraron un total de 207 infusiones. En 2 pacientes el infliximab se discontinuó debido a lumbalgia severa durante la infusion y en otros 2 por anafilaxia intrainfusional. Otras reacciones adversas ocurridas durante las infusiones fueron moderadas y respondieron adecuadamente al tratamiento estandar. Se presento un caso de artritis septica de rodilla por estafilococos. Un caso de artritis reumatoidea con insuficiencia renal compensada recibio infliximab en dosis de 1.9 mg/kg cada 30 dias, sin cambios en la funcion renal. Al momento, ningun paciente ha desarrollado tuberculosis activa. Debido a la mejoria clinica, se redujo la dosis de corticoides en 14/39 (35.9%) pacientes, de antiinflamatorios no esteroideos en 15/43 (34.8%) y de metotrexato en 12/34 (35.3%). En estaserie de casos se muestra el perfil de seguridad de infliximab, la posibilidad de reducir la dosis de drogas concomitantes,asi como algunos enfoques individuales sobre situaciones para las cuales no disponemos de guias basadas en la evidencia medica, y en las que los reumatologos debemos tomar decisiones segun las necesidades clinicas.(AU)

The benefits of angiotensin II receptor blockers in patients with renal insufficiency or failure.

Hypertension occurs frequently in patients with renal disease and contributes to the development of end-stage renal disease. Because the renin angiotensin system (RAS) influences hypertension and renal disease, angiotensin-converting enzyme (ACE) inhibitors have been used successfully to treat and reduce renal consequences of hypertension. This review assesses how angiotensin II (A-II) influences renal disease and explores the effectiveness of losartan, a selective A-II receptor blocker, in patients with renal disease. Clinical trials have demonstrated that losartan is a safe and effective treatment for hypertension in renally impaired patients and produces renal hemodynamic effects akin to those seen with ACE inhibitors. However, losartan demonstrates a greater uricosuric effect than ACE inhibitors and does not produce cough, a significant side effect frequently associated with ACE inhibitors. Further studies will determine whether combination therapy with an ACE inhibitor and A-II receptor blocker will provide additional RAS blockade and synergistic benefits in patients with renal disease.