Six years of experience with nightly home hemodialysis access

Background: Lynchburg Nephrology Dialysis Incorporated started its nightly home hemodialysis (NHHD) program in September 1997. Purpose: The purpose of this study was to evaluate episodes of exit‐site infections, catheter sepsis, and safety and longevity of accesses for patients doing NHHD. Method: If internal jugular (IJ) catheter was chosen, the patient was started on 2 mg coumadin per day when catheter was placed. If catheter malfunctioned, it was blocked with a thrombolytic agent and coumadin was adjusted to meet a goal international normalized ratio (INR) of 1.5 to 2.25. If the problem persisted, the catheter was exchanged. For catheters, a threaded lock cannula (BD InterLink device, BD) was used to prevent air emboli and infections and a locking device was used to prevent disconnects. If arteriovenous (AV) fistula was used, four buttonholes were established using 16‐gauge needles. If AV graft was used, patients were taught the rope ladder cannulation technique using 16‐gauge needles. Results: As of September 1, 2003, 45 patients have completed training and have performed 27,063 treatments at home. Total catheter time at home was 930 months. Total AV fistula and AV graft times at home were 190 and 20 months, respectively. Upon completion of training, 34 patients were using tunneled IJ catheters, 10 were using AV fistulas, and 1 was using an AV graft. The IJ catheter exit‐site and sepsis infection rates were 0.35 and 0.52 episodes per 1000 patient‐days, respectively. Mean catheter life was 8.5 months with the longest being 66.7 months and the shortest being 0.2 months. The AV fistula and graft exit‐site and sepsis infection rates were 0.16 and 0 episodes per 1000 patient‐days, respectively. Catheter complications included one episode of disconnect due to patient's failure to use the locking device, one episode of central stenosis, and one episode of intracranial hemorrhage, due to prolonged INR, with resolution of symptoms. Conclusion: Data support the fact that tunneled IJ catheters, AV fistulas, and AV grafts are effective and safe permanent accesses for patients on NHHD.     

A simulation study of long throw sputtering for diffusion barrierdeposition into high aspect vias and contacts

Modified sputtering techniques, such as long throw sputtering, collimation, and ionized sputtering, have been proposed to improve VLSI topography bottom coverage by narrowing the angular distribution of the sputter flux at the substrate and reducing subsequent flux shadowing at the bottom of topography. This paper first investigates a number of unique aspects involved in the simulation of long throw sputter systems. In particular, time importance of inhomogeneous film density and nonunity sticking coefficients are addressed. The second part of the paper presents a simulation study of long throw sputtering, providing a comparison to collimated and standard sputtering systems. The simulations are performed using the SIMSPUD/SIMBAD ballistic deposition tool. SIMSPUD is used to study film uniformity over a 300-mm wafer and to generate angular distributions at the center and edge of the wafer. The ability of SIMBAD to simulate directed sputtering systems is verified by direct comparison to Ti films deposited into oxide trenches. The importance of modeling the film microstructure is demonstrated by comparison between cross-sectional SEM's micrograph for evaporation and modeling results, such as long throw sputtering with a variety of substrate/target spacings, typical “standard” as well as “collimated” systems. SEM's of overhang structures and simulations are also presented to demonstrate nonunity sticking during the co-sputtering of TiW     

The Effect of Nanotube Content and Orientation on the Mechanical Properties of Polymer–Nanotube Composite Fibers: Separating Intrinsic Reinforcement from Orientational Effects

We have measured the mechanical properties of coagulation‐spun polymer–nanotube composite fibers. Both the fiber modulus, Y, and strength, σ_B, scale linearly with volume fraction, V_f, up to V_f ～10%, after which these properties remain constant. We measured dY/dV_f = 254 GPa and dσ_B/dV_f = 2.8 GPa in the linear region. By drawing fibers with V_f < 10% to a draw ratio of ～60%, we can increase these values to dY/dV_f = 600 GPa and dσ_B/dV_f = 7 GPa. Raman measurements show the Herman's orientation parameter, S, to increase with drawing, indicating that significant nanotube alignment occurs. Raman spectroscopy also shows that the nanotube effective modulus, Y_Eff, also increases with drawing. We have calculated an empirical relationship between the nanotube orientation efficiency factor, η_o, and S. This allows us to fit the data for Y_Eff versus η_o, showing that the fiber modulus scales linearly with η_o, as predicted theoretically by Krenchel. From the fit, we estimate the nanotube modulus to be; Y_NT = 480 GPa. Finally, we show that the fiber strength also scales linearly with η_o, giving an effective interfacial stress transfer of τ = 40 MPa and a nanotube critical length of l_c=1250 nm. This work demonstrates the validity of the Cox‐Krenchel rule of mixtures and shows that continuum theory still applies at the near‐molecular level.     

The effects of increased police enforcement along a route in London

There have been many studies of the link between the level of policing in an area and the behaviour of local drivers, but those that have been conducted in the United Kingdom were either small scale or were conducted many years ago. Consequently, a practical trial was carried out in London in May 2008 to investigate the effects of increasing the level of traffic policing in a busy urban area under modern conditions. Operation Radar ran for four weeks and increased the visible presence of police on a six mile stretch of the A23 in South London. Two teams of six officers and one sergeant were deployed in two shifts per weekday on the six mile route, using both static and mobile policing methods in a mixture of vehicles.This paper summarises the effects achieved, both in terms of the number of offences detected by the police and the effects on driver behaviour observed by a series of roadside surveys. These surveys measured vehicle speeds and drivers’ use of mobile phones and seatbelts. Vehicle speeds reduced systematically during the operation along the route and in surrounding areas, and some effects remained at least two weeks after the operation had finished. The survey data do not, however, show any positive effect of enforcement on the use of mobile phones or seatbelts.     

A lead isotopic study of the human bioaccessibility of lead in urban soils from Glasgow, Scotland

The human bioaccessibility of lead (Pb) in Pb-contaminated soils from the Glasgow area was determined by the Unified Bioaccessibility Research Group of Europe (BARGE) Method (UBM), an in vitro physiologically based extraction scheme that mimics the chemical environment of the human gastrointestinal system and contains both stomach and intestine compartments. For 27 soils ranging in total Pb concentration from 126 to 2160 mg kg^− 1 (median 539 mg kg^− 1), bioaccessibility as determined by the ‘stomach’ simulation (pH ~ 1.5) was 46-1580 mg kg^− 1, equivalent to 23-77% (mean 52%) of soil total Pb concentration. The corresponding bioaccessibility data for the ‘stomach + intestine’ simulation (pH ~ 6.3) were 6-623 mg kg^− 1 and 2-42% (mean 22%) of soil Pb concentration. The soil ²⁰⁶Pb/²⁰⁷Pb ratios ranged from 1.057 to 1.175. Three-isotope plots of ²⁰⁸Pb/²⁰⁶Pb against ²⁰⁶Pb/²⁰⁷Pb demonstrated that ²⁰⁶Pb/²⁰⁷Pb ratios were intermediate between values for source end-member extremes of imported Australian Pb ore (1.04) - used in the manufacture of alkyl Pb compounds (1.06-1.10) formerly added to petrol - and indigenous Pb ores/coal (1.17-1.19). The ²⁰⁶Pb/²⁰⁷Pb ratios of the UBM ‘stomach’ extracts were similar (< 0.01 difference) to those of the soil for 26 of the 27 samples (r = 0.993, p < 0.001) and lower in 24 of them. A slight preference for lower ²⁰⁶Pb/²⁰⁷Pb ratio was discernible in the UBM. However, the source of Pb appeared to be less important in determining the extent of UBM-bioaccessible Pb than the overall soil total Pb concentration and the soil phases with which the Pb was associated. The significant phases identified in a subset of samples were carbonates, manganese oxides, iron-aluminium oxyhydroxides and clays.     

Carfilzomib Promotes the Unfolded Protein Response and Apoptosis in Cetuximab-Resistant Colorectal Cancer

Cetuximab is a common treatment option for patients with wild-type K-Ras colorectal carcinoma. However, patients often display intrinsic resistance or acquire resistance to cetuximab following treatment. Here we generate two human CRC cells with acquired resistance to cetuximab that are derived from cetuximab-sensitive parental cell lines. These cetuximab-resistant cells display greater in vitro proliferation, colony formation and migration, and in vivo tumour growth compared with their parental counterparts. To evaluate potential alternative therapeutics to cetuximab-acquired-resistant cells, we tested the efficacy of 38 current FDA-approved agents against our cetuximab-acquired-resistant clones. We identified carfilzomib, a selective proteosome inhibitor to be most effective against our cell lines. Carfilzomib displayed potent antiproliferative effects, induced the unfolded protein response as determined by enhanced CHOP expression and ATF6 activity, and enhanced apoptosis as determined by enhanced caspase-3/7 activity. Overall, our results indicate a potentially novel indication for carfilzomib: that of a potential alternative agent to treat cetuximab-resistant colorectal cancer.     

Large-scale simulations of crack–void and void–void plasticity in metallic fcc crystals under high strain rates

We have simulated the failure of three-dimensional fcc solids containing voids under mode one tension using molecular dynamics, simple interatomic potentials and a system comprising 15 million atoms. When a linear brittle crack front approaches a void, the void acts to impede the progress of the front by causing dislocation emission, thereby rendering the system ductile. When two voids are alone in the system, failure is via ductility with, first, dislocation loops being emitted from the void surfaces and, then, these loops interacting with one another to form.     

A prototype strategy for construction of personality scales.

Examined the predictive validity of different strategies for constructing personality scales. The Adjective Check List (ACL) was used as a common item pool to construct sets of 8 scales by each of 6 strategies. A prototype strategy was introduced as a proposed improvement on rational scale construction methodology. Its validity was compared with 4 traditional strategies (empirical, factor analytic, rational, and internal consistency) and 1 random strategy in predicting 8 criterion measures. Ss were 234 paid fraternity males (aged 18–26 yrs) who supplied ACL responses and 8 criterion measures in the form of peer ratings. Included in the 8 criteria were peer ratings on the traits of achievement, dominance, nurturance, affiliation, exhibition, autonomy, aggression, and deference. Zero-order correlational analyses were followed by multiple-regression procedures used in a double cross-validation design. The prototype strategy was statistically superior to all of the other strategies, and further research on this methodology is urged. (43 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)