Laser-driven three-stage heavy-ion acceleration from relativistic laser-plasma interaction

A three-stage heavy ion acceleration scheme for generation of high-energy quasimonoenergetic heavy ion beams is investigated using two-dimensional particle-in-cell simulation and analytical modeling. The scheme is based on the interaction of an intense linearly polarized laser pulse with a compound two-layer target (a front heavy ion layer + a second light ion layer). We identify that, under appropriate conditions, the heavy ions preaccelerated by a two-stage acceleration process in the front layer can be injected into the light ion shock wave in the second layer for a further third-stage acceleration. These injected heavy ions are not influenced by the screening effect from the light ions, and an isolated high-energy heavy ion beam with relatively low-energy spread is thus formed. Two-dimensional particle-in-cell simulations show that ∼100MeV/u quasimonoenergetic Fe24+ beams can be obtained by linearly polarized laser pulses at intensities of 1.1×1021W/cm². 

The effect of dietary nitrate on salivary, plasma, and urinary nitrate metabolism in humans

Dietary nitrate is metabolized to nitrite by bacterial flora on the posterior surface of the tongue leading to increased salivary nitrite concentrations. In the acidic environment of the stomach, nitrite forms nitrous acid, a potent nitrating/nitrosating agent. The aim of this study was to examine the pharmacokinetics of dietary nitrate in relation to the formation of salivary, plasma, and urinary nitrite and nitrate in healthy subjects. A secondary aim was to determine whether dietary nitrate increases the formation of protein-bound 3-nitrotyrosine in plasma, and if dietary nitrate improves platelet function. The pharmacokinetic profile of urinary nitrate excretion indicates total clearance of consumed nitrate in a 24 h period. While urinary, salivary, and plasma nitrate concentrations increased between 4- and 7-fold, a significant increase in nitrite was only detected in saliva (7-fold). High dietary nitrate consumption does not cause a significant acute change in plasma concentrations of 3-nitrotyrosine or in platelet function.

Plasma free fatty acids do not provide the link between obesity and insulin resistance or β-cell dysfunction: results of the Reading, Imperial, Surrey, Cambridge, Kings (RISCK) study

Aims To investigate the relationship between adiposity and plasma free fatty acid levels and the influence of total plasma free fatty acid level on insulin sensitivity and β-cell function. Methods An insulin sensitivity index, acute insulin response to glucose and a disposition index, derived from i.v. glucose tolerance minimal model analysis and total fasting plasma free fatty acid levels were available for 533 participants in the Reading, Imperial, Surrey, Cambridge, Kings study. Bivariate correlations were made between insulin sensitivity index, acute insulin response to glucose and disposition index and both adiposity measures (BMI, waist circumference and body fat mass) and total plasma free fatty acid levels. Multivariate linear regression analysis was performed, controlling for age, sex, ethnicity and adiposity. Results After adjustment, all adiposity measures were inversely associated with insulin sensitivity index (BMI: β = −0.357; waist circumference: β = −0.380; body fat mass: β = −0.375) and disposition index (BMI: β = −0.215; waist circumference: β = −0.248; body fat mass: β = −0.221) and positively associated with acute insulin response to glucose [BMI: β = 0.200; waist circumference: β = 0.195; body fat mass β = 0.209 (P values <0.001)]. Adiposity explained 13, 4 and 5% of the variation in insulin sensitivity index, acute insulin response to glucose and disposition index, respectively. After adjustment, no adiposity measure was associated with free fatty acid level, but total plasma free fatty acid level was inversely associated with insulin sensitivity index (β = −0.133), acute insulin response to glucose (β = −0.148) and disposition index [β = −0.218 (P values <0.01)]. Plasma free fatty acid concentration accounted for 1.5, 2 and 4% of the variation in insulin sensitivity index, acute insulin response to glucose and disposition index, respectively. Conclusions Plasma free fatty acid levels have a modest negative association with insulin sensitivity, β-cell secretion and disposition index but no association with adiposity measures. It is unlikely that plasma free fatty acids are the primary mediators of obesity-related insulin resistance or β-cell dysfunction.

Altered plasma response to zinc and iron tolerance test after Roux-en-Y gastric bypass

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Bone healing in critical-size defects treated with platelet-rich plasma: a histologic and histometric study in the calvaria of diabetic rat

Objective. The objective of this study was to histologically analyze the influence of the platelet-rich plasma (PRP) on bone healing in surgically created critical-size defects (CSD) in the calvaria of diabetic rats.Study design. A total of 20 diabetic rats were divided into 2 groups: C (control) and PRP. A 5-mm diameter CSD was created in the calvarium of each animal. In Group C, the defect was filled by blood clot only. In Group PRP, 0.35 mL of PRP was placed in the defects. All animals were humanely killed 30 days postoperatively. Histometric and histologic analyses were performed. Data were statistically analyzed (t test, P < .05).Results. No defect completely regenerated with bone. Group PRP had a statistically greater amount of bone formation than Group C (37.22% +/- 6.00% and 21.68% +/- 11.35%, respectively).Conclusion. PRP placed in the defects significantly enhanced bone healing in CSD in the calvaria of diabetic rats both qualitatively and quantitatively. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2010; 109: 72-78)

A study of histological responses from Ti-6Al-7Nb alloy dental implants with and without plasma-sprayed hydroxyapatite coating in dogs

Titanium alloys are hoped to be used much more for applications as implant materials in the medical and dental fields because of their basic properties, such as biocompatibility, corrosion resistance and specific strength compared with other metallic implant materials. Thus, the Ti-6Al-7Nb alloy that has recently been developed for biomedical use, that is, primarily developed for orthopaedic use, is to be studied in this paper, for application in dental implants. The biocompatibility test in vivo was carried out in dogs and the osseointegration was verified through histological analysis of the samples of the Ti-6Al-7Nb alloy with and without hydroxyapatite coating that were inserted in the alveoli. Within the controlled conditions the samples did not show any toxic effects on the cells. (C) 2001 Kluwer Academic Publishers.

The acid-base impact of free water removal from, and addition to, plasma

Water, compared with plasma at a pH of 7.4, is a weak acid. The addition of free water to a patient should have an acidifying effect (dilutional acidosis) and the removal of it, an alkalinizing effect (concentrational alkalosis). The specific effects of free water loss or gain in a relatively complex fluid such as plasma has, to the authors' knowledge, not been reported. This information would be useful in the interpretation of the effect of changes in free water in patients. Plasma samples from goats were either evaporated in a tonometer to 80% of baseline volume or hydrated by the addition of distilled water to 120% of baseline volume. The pH and partial pressure of carbon dioxide, sodium, potassium, ionized calcium, chloride, lactate, phosphorous, albumin, and total protein concentrations were measured. Actual base excess (ABE), standard bicarbonate, anion gap, strong ion difference, strong ion gap, unmeasured anions, and the effects of sodium, chloride, phosphate, and albumin changes on ABE were calculated. Most parameters changed 20% in proportion to the magnitude of dehydration or hydration. Bicarbonate concentration, however, increased only 11% in the evaporation trial and decreased only -2% in the dehydration trial. The evaporation trial was associated with a mild, but significant, metabolic alkalotic effect (ABE increased 3.2 mM/L), whereas the hydration trial was associated with a slight, insignificant metabolic acidotic effect (ABE decreased only 0.6 mM/L). The calculated free water ABE effect (change in sodium concentration) was offset by opposite changes in calculated chloride, lactate, phosphate, and albumin ABE effects.

Serum iron and plasma fibrinogen concentrations as indicators of systemic inflammatory diseases in horses

Background: Detection of systemic inflammation, which is important for proper diagnosis and prompt treatment, can be challenging.Hypothesis: Measurement of plasma iron concentration is a sensitive method for detecting systemic inflammation in horses compared with measurements of plasma Fibrinogen concentration, a traditional marker for inflammation in the horse.Animals: Ninety-seven horses hospitalized with diseases causing systemic inflammation, 22 horses with localized inflammation, and 12 clinically normal horses were included in this study.Methods: A retrospective study was made on hospitalized horses that had both plasma iron and fibrinogen concentrations measured on hospital admission.Results: Plasma iron concentration was lower in horses with systemic inflammation (64 +/- 45 mu g/dL) than the reference interval minimum (105 mu g/dL) and were significantly lower (P = .001) than the value in a group of horses with local inflammation (123 +/- 45 mu g/dL) and in healthy transported horses (143 +/- 29 mu g/dL). Low plasma iron and high fibrinogen concentrations were both sensitive indicators of systemic inflammation in horses with sensitivity of 90 and 82%, respectively. There was a similar correlation between either continued decreases in iron concentration (R-sp of 0.239) or increases in fibrinogen concentration (R-sp of 0.280) during hospitalization and a worse prognosis.Conclusions and Clinical Importance: Measurement of plasma iron concentration better reflected acute inflammation than did fibrinogen concentration.