The identity of the amyl branch in low-density polyethylenes

Amyl branches have been positively identified as one of the principal short short chain branches in low density polyethylenes prepared by high pressure processes.     

A method for monitoring uterine activity in induced labour

A system for the quantitative assessment of uterine activity during an oxytocin-induced labour has been developed. This has been achieved using relatively simple analogue techniques and can easily be used in the labour ward alongside existing monitoring equipment. Initial results indicate that a plateau of uterine activity can be easily recognised from the display and maintained at oxytocin dosage levels below those that might normally be used.     

Precipitation Coating of Rare-Earth Orthophosphates on Woven Ceramic Fibers—Effect of Rare-Earth Cation on Coating Morphology and Coated Fiber Strength

Monazite (La, Ce, Nd, and GdPO₄) and xenotime (Tb, Dy, and YPO₄) coatings were deposited on woven Nextel^™ 610 and 720 fibers by heterogeneous precipitation from a rare-earth citrate/phosphoric acid precursor. Coating phases and microstructure were characterized by SEM and TEM, and coated fiber strength was measured after heat treatment at 1200°C for 2 h. Coated fiber strength increased with decreasing ionic radius of the rare-earth cation in the monazite and xenotime coatings, and correlates with the high-temperature weight loss and the densification rate of the coatings. Dense coatings with trapped porosity and high weight loss at a high temperature degrade fiber strength the most. The degradation is consistent with stress corrosion driven by thermal residual stress from coating precursor decomposition products trapped in the coating at a high temperature.     

Low Voltage Electrowetting-on-Dielectric Platform using Multi-Layer Insulators

A low voltage, two-level-metal, and multi-layer insulator electrowetting-on-dielectric (EWD) platform is presented. Dispensing 300pl droplets from 140nl closed on-chip reservoirs was accomplished with as little as 11.4V solely through EWD forces, and the actuation threshold voltage was 7.2V with a 1Hz voltage switching rate between electrodes. EWD devices were fabricated with a multilayer insulator consisting of 135nm sputtered tantalum pentoxide (Ta(2)O(5)) and 180nm parylene C coated with 70nm of CYTOP. Furthermore, the minimum actuation threshold voltage followed a previously published scaling model for the threshold voltage, V(T), which is proportional to (t/ε(r))(1/2), where t and ε(r) are the insulator thickness and dielectric constant respectively. Device threshold voltages are compared for several insulator thicknesses (200nm, 500nm, and 1μm), different dielectric materials (parylene C and tantalum pentoxide), and homogeneous versus heterogeneous compositions. Additionally, we used a two-level-metal fabrication process, which enables the fabrication of smaller and denser electrodes with high interconnect routing flexibility. We also have achieved low dispensing and actuation voltages for scaled devices with 30pl droplets.     

Binding of heavy metal ions by formaldehyde-polymerized peanut skins

Peanut skin, when treated with formaldehyde to polymerize tannins, is a highly efficient substrate for removal of many heavy metal ions from aqueous waste solutions. The ions Ag¹⁺, Cd²⁺, Cr⁶⁺, Cu²⁺, Hg²⁺, Ni²⁺, Pb²⁺, Zn²⁺, as well as Ca²⁺ and Mg²⁺, were contacted with formaldehyde-treated peanut skin. Quantitative removal could be achieved with Ag¹⁺, Cd²⁺, Cu²⁺, Hg²⁺, Pb²⁺, and Zn²⁺. Capacity of the substrate for ions was promising for Pb²⁺ (2.1 meq/g substrate), Cu²⁺ (3.0 meq/g), and Cd²⁺ (1.3 meq/g). Sorption from a solution containing Cd²⁺, Cu²⁺, Hg²⁺, Ni²⁺, Pb²⁺, Zn²⁺, on a packed column of formaldehyde-treated peanut skin indicated that Hg²⁺, Pb²⁺, and Cu²⁺ were rapidly and completely bound to the packing, while Cd²⁺, Ni²⁺, and Zn²⁺ were poorly bound until the preferred ions had been removed from solution.     

Working memory capacity and go/no-go task performance: Selective effects of updating, maintenance, and inhibition.

The ability to temporarily maintain information in order to successfully perform a task is important in many daily activities. However, the ability to quickly and accurately update existing mental representations in distracting situations is also imperative in many of these same circumstances. In the current studies, individuals varying in working memory capacity (WMC) performed different varieties of go/no-go tasks that have been hypothesized to measure inhibitory ability. The results indicated that low-WMC individuals relative to high-WMC individuals showed worse performance specifically in certain conditions of the conditional go/no-go task. Further analyses showed that increasing the temporal lag/number of intervening items between the previous target and the current lure had a deleterious effect on the performance of the low-WMC group only. The results indicate a relationship between WMC and the ability to selectively update, maintain, and retrieve information, especially in interference-rich conditions. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Cigarette use among migrant and nonmigrant Mexican American youth: A socialization latent-variable model.

A self-report survey of cigarette use among 10th- and 12th-grade Mexican American students found no differences in rates of use by migrant status. Male students reported higher levels of lifetime, experimental, and daily smoking than female students, and 12th-grade students reported higher levels of daily smoking than 10th-grade students. A socialization model of cigarette use based on peer cluster theory was evaluated using structural equation methods, examining the effects of family strength, family tobacco use, school adjustment, religious identification, and peer tobacco associations. The basic latent-structure socialization model was supported in all groups, but final models including specific effects identified both unique and common relationships by gender and migrant status. Common patterns across groups suggest that completely different prevention programs may not be necessary for these youth. However, program elements based on subtle group differences may serve to tailor prevention efforts and make them more effective. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Intermediate-grade lymphomas treated with cyclophosphamide-doxorubicin- vincristine-prednisone-bleomycin alternated with cyclophosphamide-methotrexate-etoposide-dexamethasone. Application of prognostic models to data analysis

BACKGROUND: Numerous treatment strategies have been tried with the aim of improving results for patients with intermediate-grade lymphomas (IGL) over those achieved with cyclophosphamide, doxorubicin, vincristine, prednisone, and bleomycin (CHOP-Bleo), and numerous prognostic models have been developed to identify and separate risk groups. This study reports on a new protocol for Ann Arbor Stages II-IV IGL that consists of CHOP-Bleo alternated with a new regimen of cyclophosphamide, methotrexate, etoposide, and dexamethasone (CMED) and radiation therapy and demonstrates the usefulness of prognostic models for identifying risk groups and comparing treatment programs. METHODS: One hundred seventy patients with Ann Arbor Stages II-IV IGL were treated with alternating cycles of CHOP-Bleo and CMED for a total of 12 cycles. Involved field radiation therapy was interspersed with courses of chemotherapy for patients with Stage II and Stage III disease. Results were analyzed and compared with those of the authors' previous study of CHOP-Bleo and radiation therapy using the Ann Arbor staging system, their earlier prognostic model, and the recently published International Index. RESULTS: A complete remission occurred in 78% of the patients. The overall 5-year survival rate was 67%. Survival was better for patients with Ann Arbor Stage II disease (80%) than for those with Stage III or Stage IV (67% and 58%, respectively). High tumor burden, above-normal levels of serum lactic dehydrogenase, serum beta 2-microglobulin, and Ann Arbor Stage IV disease were adverse factors. The International Index and the authors' earlier prognostic model separated four prognostic groups. CHOP-Bleo/CMED was generally well tolerated. Neutropenic fever was the major complication that occurred in 25 patients during treatment. Six of these patients died of sepsis. CONCLUSIONS: This study demonstrated that CHOP-Bleo/CMED is a well-tolerated regimen that produced better results than those reported for a former study that used CHOP-Bleo alone. Further, results for CHOP-Bleo/CMED compared favorably with those of other second- and third-generation regimens. The study also validated the usefulness of prognostic models and, in particular, the new International Index for identifying risk groups.     

The limit of viability--neonatal outcome of infants born at 22 to 25 weeks' gestation

BACKGROUND: With improved survival of preterm infants, questions have been raised about the limit of viability. To provide better information and counseling for parents of infants about to be delivered after 22 to 25 weeks' gestation, we evaluated the mortality and neonatal morbidity of preterm infants born at these gestational ages. METHODS: We studied retrospectively all 142 infants born at 22 to 25 weeks' gestation (as judged by best obstetrical estimate) from May 1988 through September 1991 in a single hospital. Mortality in the first six months, including stillbirths, and neonatal morbidity (i.e., the presence of intracranial pathologic conditions, chronic lung disease, and retinopathy of prematurity) were analyzed. RESULTS: Fifty-six infants (39 percent) survived for six months. Survival improved with increasing gestational age; none of 29 infants born at 22 weeks' gestation survived, as compared with 6 of 40 (15 percent) born at 23 weeks, 19 of 34 (56 percent) born at 24 weeks, and 31 of 39 (79 percent) born at 25 weeks. There were seven stillbirths at 22 weeks' gestation and four stillbirths at 23 weeks. The more immature the infant, the higher the incidence of neonatal complications as determined by the number of days of mechanical ventilation, the length of the hospital stay, and the presence of retinopathy of prematurity, periventricular or intraventricular hemorrhage, or periventricular leukomalacia. Only 2 percent of infants born at 23 weeks' gestation survived without severe abnormalities on cranial ultrasonography, as compared with 21 percent of those born at 24 weeks and 69 percent of those born at 25 weeks. CONCLUSIONS: We believe that aggressive resuscitation of infants born at 25 weeks' gestation is indicated, but not of those born at 22 weeks. Whether the occasional child who is born at 23 or 24 weeks' gestation and does well justifies the considerable mortality and morbidity of the majority is a question that should be discussed by parents, health care providers, and society.