A hydrophilic matrix for boron isolation: Monodisperse-porous poly(glycidyl methacrylate-co-ethylene dimethacrylate) particles carrying diol functionality

The novel chelating adsorbent has been synthesized by functionalization of monodisperse-porous poly(glycidyl methacrylate-co-ethylene dimethacrylate) particles with N-methylglucamine (NMDG) as a boron selective ligand. The resulting resin can adsorb boron in almost all pH range (pH 4–10) and its maximum capacity is ca. 12 mg/g. The adsorption behavior of poly(GMA-co-EDM)NMDG resin obeyed Langmuir isotherm well.     

Charged excitons, Auger recombination and optical gain in CdSe/CdS nanocrystals

CdSe/CdS colloidal nanocrystals are members of a novel class of light-emitting nanoparticles with remarkable optical properties such as suppressed fluorescence blinking and enhanced emission from multiexciton states. These properties have been linked to the suppression of non-radiative Auger recombination. In this work we employ ultrafast spectroscopy techniques to identify optical signatures of neutral and charged excitonic and multiexcitonic states. We show that Auger recombination of biexcitons is not suppressed, while we observe optical gain and amplified spontaneous emission from multiexciton states and from long-lived charged-exciton states.     

Pharmacokinetics and antiretroviral activity of lamivudine alone or when coadministered with zidovudine in human immunodeficiency virus type 1-infected pregnant women and their offspring

The safety, pharmacokinetics, and antiretroviral activity of lamivudine alone and in combination with zidovudine was studied in pregnant women infected with human immunodeficiency virus type 1 (HIV-1) and their neonates. Women received the drugs orally from week 38 of pregnancy to 1 week after delivery. Neonate therapy began 12 h after delivery and continued for 1 week. Both treatment regimens were well-tolerated in women and newborns. Lamivudine and zidovudine pharmacokinetics in pregnant women were similar to those in nonpregnant adults. Lamivudine and zidovudine freely crossed the placenta and were secreted in breast milk. Neonatal lamivudine clearance was about half that in pediatric patients; zidovudine clearance was consistent with previous reports. HIV-1 RNA could be quantified in 17 of the 20 women. At the onset of labor/delivery, mean virus load had decreased by approximately 1.5 log10 copies/mL in both treatment cohorts. Although not definitive for HIV-1 infection status, all neonates had HIV-1 RNA levels below the limit of quantification at birth and at ages 1 and 2 weeks.     

Effect of fibers treatment on dynamic mechanical and thermal properties of epoxy hybrid composites

Epoxy hybrid composites fabricated by reinforcing 2‐hydroxy ethyl acrylate (2‐HEA) treated oil palm empty fruit bunch (EFB) and jute fibers. It assume that chemical modification of jute and oil palm EFB fibers increased fiber/matrix interfacial bonding and it results in enhanced thermal properties of hybrid composites. Dynamic mechanical and thermal analysis of treated hybrid composites was carried out. Results indicated that chemical modification of oil palm EFB and jute fibers affect the dynamic mechanical and thermal properties of hybrid composites. The storage modulus values of hybrid composites increases with chemical treatment and loss modulus increased with fiber treatment in hybrid composites. Damping factor peak values of treated hybrid composites shifted toward the lower temperature compared to both untreated hybrid composites. Cole–Cole analysis was made to understand the phase behaviour of the hybrid composites. Thermogravimetric analysis indicated an increased in thermal stability of hybrid composite with the incorporation of chemically modified fibers. POLYM. COMPOS., 36:1669–1674, 2015. © 2014 Society of Plastics Engineers     

Interactive behavior of caffeine at a platinum electrode surface

Interactive behavior of caffeine at a charged platinum/solution interface was investigated in a wide temperature range, from 295 to 333 K, in a phosphate buffer solution pH 7.0. It was shown that the amount of adsorbed caffeine (surface concentration) is directly proportional to the measured adsorption surface charge density resulting from caffeine oxidation to theophilline. At low temperatures, a monolayer of caffeine molecules laying in a flat orientation on the Pt surface is adsorbed, while at higher temperatures, conformational changes occur, resulting in tilting of the adsorbed molecules to allow for higher surface concentrations to be achieved. A highly negative Gibbs energy of adsorption, ranging from −51.1 kJ mol⁻¹ at 295 K to −60.6 kJ mol⁻¹ at 333 K, demonstrated a high affinity of caffeine for the Pt surface. Although the adsorption process was found to be endothermic (ΔH_ADS = 20 kJ mol⁻¹), it was determined that a large positive change in the adsorption entropy (TΔS_ADS = 75 ± 3 kJ mol⁻¹) represents the driving force for the strong interaction of caffeine with Pt.     

Effect of MnO2 on the electrical conductivity of ZrO2

Electrical conductivity of ZrO₂ doped with MnO₂ has been measured at various temperatures for different molar ratios. The conductivity increases due to hopping of oxygen into neighboring vacancies, created by doping. Increase in temperature increases the rate of hopping, which results in the rise in conductivity and after attaining a maximum the conductivity, decrease due to collapse of the fluorite framework. All compositions show phase transition in ZrO₂ from monoclinic to tetragonal at 746 K. The XRD, DTA, and FT-IR studies were carried out for confirming the doping effect and transition in ZrO₂. The text was submitted by the authors in English.     

Serum levels of interleukin 1 and tumor necrosis factor alpha correlate with peritoneal adhesion grades in humans after major abdominal surgery

Peritoneal adhesions are a leading cause of potential morbidity and mortality. We undertook this prospective study to determine the clinical relevance of interleukin 1 (IL-1) and tumor necrosis factor alpha (TNF-alpha) levels as biological markers for peritoneal adhesion formation in humans. Fifteen patients who had previous colectomies and were undergoing re-exploration for an elective vascular procedure were studied. Blood samples were collected from each patient preoperatively and 30 minutes after the abdominal incision was made. Serum levels of IL-1 and TNF-alpha were determined using enzyme-linked immunosorbent assay kits. Adhesions were graded using an adhesion scale of 0 (none), 1 (mild), 2 (moderate), and 3 (extensive, dense). Preoperative levels of IL-1 and TNF-alpha did not differ significantly among all patients (IL-1 level was 60 +/- 14 pg/mL, and TNF-alpha level was 45 +/- 11 pg/mL; mean +/- standard deviation). Significant correlation was observed between grades of adhesions and early intraoperative levels of IL-1 [101 +/- 36 pg/mL for grade 1 (n = 8) vs 298 +/- 73 pg/mL for grade 3 (n = 6); P < 0.01] and TNF-alpha (88 +/- 23 pg/mL for grade 1 vs 261 +/- 88 mL for grade 3; P < 0.02). We conclude that early elevations of IL-1 and TNF-alpha are reliable biological markers for postoperative adhesions in humans. Studies utilizing cytokines antibodies to these markers may further elucidate the efficacy of this method for prevention of peritoneal adhesions.     

Outpatient laparoscopic cholecystectomy: safe and cost effective?

OBJECTIVE: Reports on the aetiology and risk of occupational rhinitis in different occupations are scarce. METHOD: The purpose of this study was to find the occupations with an increased risk of occupational rhinitis. Age and gender differences in occupational rhinitis and occupational asthma were also compared, and the most common causes of occupational rhinitis were analysed. DESIGN: This study covered the cases of occupational rhinitis and asthma reported to the Finnish Register of Occupational Diseases during the years 1986-1991. The cases on the Register were linked to the longitudinal census data file from the Finnish censuses. RESULTS: During 1986-1991, 1244 new cases of occupational rhinitis (474 women and 497 men) and 1867 new cases of occupational asthma (916 women and 951 men) were reported to the Register. Animal dander, flours, wood dusts, textiles, phthalic acid anhydrides and storage mites were important causes of occupational rhinitis. The highest relative risk of occupational rhinitis was among furriers, the age-standardized rate ratio (SRR) was 30.0. Bakers and livestock breeders had also a markedly elevated relative risk (SRR = 22.0). Men had the highest incidence of occupational rhinitis at the age of 25-29 years and among women the incidence gradually increased and reached the peak in the group 40-44 years of age. CONCLUSION: Furriers, bakers, and livestock breeders had the most elevated relative risk of occupational rhinitis. Occupational rhinitis cases reported at a younger age than asthma, suggesting that rhinitis often precedes asthma.     

Clinical comparison of three methods to determine resting energy expenditure

An accurate and reliable method of determining resting energy expenditure in the critical care setting is crucial because inadequate caloric intake and excessive caloric intake are both associated with a number of complications. Energy requirements were determined by three different methods in a group of 25 post-cardiac surgery patients in the intensive care unit. Patients were intubated and had a thermodilution pulmonary artery catheter in place. The first method measured resting energy expenditure by indirect calorimetry. For the second method, the results of blood gases drawn at the same time that indirect calorimetry was measured were used in the Fick equation. In the third method, a registered dietitian assessed each patient by using the Harris-Benedict equation with stress factor modification. Indirect calorimetry was considered the standard with which the other two methods were compared. The results showed that, compared with calorimetry, both the Fick equation and the Harris-Benedict equation underestimated resting energy needs. Statistically, only the difference between the Fick equation method and indirect calorimetry was significant. Clinically, however, both methods seem to have applicability.