Grand canonical Monte Carlo molecular simulations have been carried out for adsorption of nitrogen at 77 K on square arrays of open and closed single-wall carbon nanotubes with diameters of 6-30 Å and nanotube separations of 4-30 Å. Exohedral spaces for arrays of closed nanotubes with small tube separations are microporous. For large separations, two-stage adsorption occurs, corresponding to monolayer formation followed by a condensation step. Filling of the exohedral space is dominated by geometrical factors that allow the calculation of adsorbate molecular packing factors, which are close to that for liquid nitrogen. The amounts adsorbed in arrays of open nanotubes are higher than for closed tube arrays, as expected. The highest increase is for arrays with small tube separations and large tube diameters, where endohedral adsorption dominates; for wider tube separations the increase in amount adsorbed is less because exohedral adsorption becomes important. Arrays of single-wall carbon nanotubes have the potential to develop very high adsorptive capacities, to which the interstitial spaces between the nanotubes make significant contributions. The adsorptive capacity can be optimized when exohedral adsorption dominates, that is, with arrays of narrow single-wall nanotubes with wide spacings between them.

CT angiography is an accurate, cost-effective tool in the diagnosis of acute GI bleeding and can show the precise location of bleeding, thereby directing further management.

Grand canonical ensemble Monte Carlo (GCEMC) molecular simulations of hydrogen storage at 298 and 77 K in triangular arrays of single wall carbon nanotubes (SWCNT) and in slit pores (modeling activated carbons) were performed. At 298 K the US DOE target gravimetric hydrogen storage capacity (6.5 wt %) is reached at 160 bar for optimally configured arrays of open SWCNT of wide diameter, but the equivalent volumetric capacity is ∼40% of the DOE target [695 (STP) v/v]. For slit pores at 298 K the optimal volumetric capacity is ∼20% of the target. Simulations for 77 K and 70 bar indicate that triangular arrays of open and closed SWCNT of various diameters in a wide range of configurations exceed the DOE gravimetric target. A capacity of 33 wt % is found for arrays of narrow, open, or closed SWCNT that are widely spaced.Here, adsorption occurs entirely in the interstitial space between the nanotubes. Volumetric capacities close to the DOE target are found for arrays of narrow, open or closed SWCNT with a range of interstitial spacings. The maximum volumetric capacities for simulations with slit pores at 77 K and 70 bar are ∼73% of the DOE target for a range of pore widths. Capacities from simulations for nanotubes and slit pores at 298 and 77 K are in reasonable agreement with experimentally measured capacities. It is concluded that the potential of carbon nanotubes for storage of hydrogen is superior to that of activated carbons.

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BackgroundTo provide an overview of phantom limb pain (PLP) in China. This includes the prevalence of PLP and possible risk factors.MethodsIn a retrospective study, telephone interviews were conducted with 391 amputation patients who underwent extremity amputations at a tertiary hospital in China.ResultsPLP was found in 29% of the amputees. Pre-amputation pain (OR = 10.4, P = 0.002) and postoperative analgesia (OR = 4.9, P = 0.008) were identified as high-risk factors for PLP. 82.1% of PLP patients experienced pre-amputation pain. The average pain intensity of PLP was 5.1 ± 2.2, with 31.9% having severe intensity. The effects of PLP on the quality of the PLP patients were as follows: 7.8% of the patients had to limit their daily life and 29.0% of the patients had to limit their social activities. 17.3 and 25.7% of patients experienced depression and sleeping disorder respectively, while 18.9% had loss of interest and even 16.1% of PLP patients had attempted suicide. No effective treatments were found in 78.9% of these patients.ConclusionsPLP has markedly affected the lives of patients. Pre-amputation pain and postoperative epidural analgesia might be risk factors for the phantom limb pain after amputation. Prevention of pre-amputation pain and sudden post-amputation deafferentation should be recommended to the amputees.

Many outpatients who inadequately prepared for the procedure were cancelled on the day of the examination for various reasons. The aim of study was to investigate whether short message service (SMS) can improve patients' compliance and reduce cancellation rates. Outpatients scheduled for sedation gastrointestinal endoscopy were randomly assigned to mobile phone SMS group or control group. Patients in the control group received a leaflet on preparation instructions, while patients in the SMS group received SMS reminders after making an appointment. A total of 1786 patients were analyzed. There was a significant reduction in the rate of cancellations for patients in the SMS group (4.8%) compared with patients in the control group (8.0%) (P<0.001). Patients in the SMS group were 40% less likely to be cancelled by medical staff than patients in the control group. The compliance score of the two groups based on demographic and clinic characteristic distribution showed that for both male and female patients, the compliance score was higher in the SMS group than that in the control group (P=0.023, P<0.001, respectively). Additionally, the compliance score was also significantly higher in the SMS group among patients who were under 50 years old, less than an undergraduate education level, experiencing their first time for procedure, or whose procedures were gastroscopy, waiting time was between 4 and 15 days, and schedules were in morning (P≤0.032). SMS reminders can be considered a complement to conventional preparation instructions, which could help improve the compliance of outpatients and reduce the rate of cancellations.

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