1,219 research outputs found
Numerical Simulations of the Impact and Spreading of a Particulate Drop on a Solid Substrate
We present two-dimensional numerical simulations of the impact and spreading of a droplet containing a number of small particles on a flat solid surface, just after hitting the solid surface, to understand particle effects on spreading dynamics of a particle-laden droplet for the application to the industrial inkjet printing process. The Navier-Stokes equation is solved by a finite-element-based computational scheme that employs the level-set method for the accurate interface description between the drop fluid and air and a fictitious domain method for suspended particles to account for full hydrodynamic interaction. Focusing on the particle effect on droplet spreading and recoil behaviors, we report that suspended particles suppress the droplet oscillation and deformation, by investigating the drop deformations for various Reynolds numbers. This suppressed oscillatory behavior of the particulate droplet has been interpreted with the enhanced energy dissipation due to the presence of particles
Correlation between thigh skinfold thickness and physical fitness factors in Korean adults and older individuals
Background: This cross-sectional epidemiological study aimed to compare
the differences in physical fitness variables according to the skinfold thickness
in the thigh area in adults and Korean older individuals. Methods: We analyzed data from the 2015 National Fitness Survey. A
total of 4034 healthy adults (2442 men, 1592 women) with an average age of 38.19
± 12.41 years and 880 healthy older subjects (369 men, 511 women) with an
average age of 72.32 ± 5.49 years participated in this study. The skinfold
thickness of the thigh was measured using a skinfold caliper (Dynatron,
Dynatronics, USA). The participants underwent physical fitness tests, including
the hand squeeze strength test, abdominal curl ups, standing double-leg long
jump, 50 m shuttle run, sit and reach, and 20 m shuttle run for adult men and
women. Older men and women performed the following tests: hand squeeze strength,
abdominal curl ups, sit to stand test, single leg balance (open eyes), sit and
reach, Apley scratch test for shoulder mobility, and 6-minute walk test.
Independent t-tests and Pearson correlation analyses were used for the
analysis. Results: Among the older men, significant differences were found in
thigh skinfold thickness (t = –21.122, p < 0.001), abdominal
curl ups (t = 2.165, p = 0.031), and sit and reach in men
(t = 2.609, p = 0.009), and thigh skinfold (t =
–29.611, p < 0.001), and Apley scratch test for shoulder mobility in
women (t = –2.120, p = 0.034). There was a significant
correlation between thigh skinfold thickness and physical activity (thigh
skinfold thickness) in adult men (t = –54.202, p < 0.001),
nondominant hand squeeze strength (t = 2.632, p = 0.009),
abdominal curl ups (t = 4.292, p < 0.001), sit and reach
(t = 3.063, p = 0.002), twenty meters shuttle run (t =
4.657, p < 0.001).
However, no significant differences were found in
dominant hand squeeze strength, standing double leg long jump, or 50 m shuttle
run in men (p < 0.05). In adult women, there was a significant
correlation between thigh skinfold thickness and physical activity (thigh
skinfold thickness (t = –49.405, p < 0.001), dominant hand
squeeze strength (t = 7.789, p < 0.001), nondominant hand
squeeze strength (t = 6.944, p < 0.001), abdominal curl ups
(t = 5.347, p < 0.001), standing double leg long jump
(t = 5.890, p < 0.001), sit and reach (t = 5.384,
p < 0.001), twenty meter shuttle run (t = 5.223, p < 0.001).
However, no significant differences were found in fifty meter shuttle
run in women (p < 0.05). Among older men, only single leg balance and
sit and reach were correlated with thigh skinfold (single leg balance r
= 0.169, p = 0.01; sit and reach r = –0.201, p =
0.001). In women, only abdominal curl ups, sit and reach, and Apley scratch test
correlated with thigh skinfold (abdominal curl ups r = –0.088,
p = 0.002; sit and reach r = –0.137, p = 0.002; Apley
scratch test r = 0.090, p = 0.041). Conclusions: The effect of thigh skinfold thickness on the level of
physical activity was more pronounced in adults than in older subjects. Our
findings show that muscle strength and body fat in the lower extremities can
affect overall muscle strength, endurance, and balance
Helical tomotherapy with concurrent capecitabine for the treatment of inoperable pancreatic cancer
<p>Abstract</p> <p>Background</p> <p>Helical tomotherapy, an advanced intensity-modulated radiation therapy with integrated CT imaging, permits highly conformal irradiation with sparing of normal tissue. Capecitabine, a pro-drug of 5-FU that induces thymidine phosphorylase can achieve higher levels of intracellular 5-FU when administered concurrently with radiation. We evaluated the feasibility as well as the clinical outcome of concurrent administration of capecitabine with tomotherapy in patients with advanced pancreatic cancer.</p> <p>Methods</p> <p>Nineteen patients with advanced pancreatic cancer including primarily unresectable disease and recurrence after curative surgery were included in the study. Two planning target volumes (PTV) were entered: PTV1 is gross tumor volume; and PTV2, the volume of the draining lymph nodes. The total doses to target 1 and target 2 were 55 and 50 Gy, respectively. Capecitabine at 1600 mg/m<sup>2</sup>/day was administered on each day of irradiation.</p> <p>Results</p> <p>Twenty six measurable lesions were evaluated. Overall in-field response rate was 42.3%; partial responses were achieved in 53.3% of the pancreatic masses, 28.6% of distant metastatic lesions and 25.0% of regional lymph nodes. The median duration of follow-up after tomotherapy was 6.5 months. None of the lesions showed in-field progression. Treatment was well tolerated with only minor toxicities such as grade 1 nausea (one patient), grade 1 hand-foot syndrome (one patient) and grade 1/2 fatigue (three patients).</p> <p>Conclusions</p> <p>Helical tomotherapy with concurrent capecitabine is a feasible option without significant toxicities in patients with advanced pancreatic cancer. We achieved excellent conformal distribution of radiation doses and minimal treatment-related toxicities with promising target volume responses.</p
Internal evaluation of a physically-based distributed model using data from a Mediterranean mountain catchment
An evaluation of the performance of a physically-based distributed model of a small Mediterennean mountain catchment is presented. This was carried out using hydrological response data, including measurements of runoff, soil moisture, phreactic surface level and actual evapotranspiration. A-priori model parameterisation was based as far as possible on property data measured in the catchment. Limited model calibration was required to identify an appropriate value for terms controlling water loss to a deeper regional aquifer. The model provided good results for an initial calibration period, when judge in terms of catchment discharge. However, model performance for runoff declined substantially when evaluated againts a consecutive, rather drier, period of data. Evaluation against other catchment responses allowed identification of the problems responsible for the observed lack of model robustness in flow simulation. In particular, it was shown that an incorrect parameterisation of the soil water was preventing adequate representation of drainage from soils during hydrogeraph recessions. This excess moisture was then being removed via an overestimation of evapotranspiration. It also appeared that the model underestimated canopy interception. The results presented here suggest that model evaluation against catchment scale variables summarising its water balance can be of great use in identifying problems with model parameterisation, even for distributed models. Evaluation using spatially distributed data yielded less useful information on model performance, owing to the relative sparseness of data points, and problems of mismatch of scale between the measurement and the model grid.This work was carried out as part of project VAHMPIRE (Validating Hydrological Models using Process Studies and Internal Data from Research Basins: tools for assessing the hydrological impacts of environmental change), which was funded by the European Commission Framework IV Environment and Climate Program (Contract No. ENV4- CT95-0134). Simulations were carried out on a UNIX workstation funded jointly by UK Nirex Ltd. and NERC grant GR3/ E0009.Peer Reviewe
Risk Factors for Additional Surgery after Iatrogenic Perforations due to Endoscopic Submucosal Dissection
Objectives. Endoscopic resection (ER) is commonly performed to treat gastric epithelial neoplasms and subepithelial tumors. The aim of this study was to predict the risk factors for surgery after ER-induced perforation. Methods. We retrospectively reviewed the data on patients who received gastric endoscopic submucosal dissection (ESD) or endoscopic mucosal resection (EMR) between January 2010 and March 2015. Patients who were confirmed to have perforation were classified into surgery and nonsurgery groups. We aimed to determine the risk factors for surgery in patients who developed iatrogenic gastric perforations. Results. A total of 1183 patients underwent ER. Perforation occurred in 69 (5.8%) patients, and 9 patients (0.8%) required surgery to manage the perforation. In univariate analysis, anterior location of the lesion, a subepithelial lesion, two or more postprocedure pain killers within 24 hrs, and increased heart rate within 24 hrs after the procedure were the factors related to surgery. In logistic regression analysis, the location of the lesion at the anterior wall and using two or more postprocedure pain killers within 24 hrs were risk factors for surgery. Conclusion. Most cases of perforations after ER can be managed conservatively. When a patient requires two or more postprocedure pain killers within 24 hrs and the lesion is located on the anterior wall, early surgery should be considered instead of conservative management
N-doped graphitic self-encapsulation for high performance silicon anodes in lithium-ion batteries
N-doped sites at CNT and graphene trigger spontaneous encapsulation of Si particles by simple pH control at room temperature. Significantly, N-doped CNT encapsulated Si composite electrode materials show remarkable cycle life and rate performance in battery operations. Superior capacity retention of 79.4% is obtained after 200 cycles and excellent rate capability of 914 mA h g -1 is observed at a 10 C rate.close13
Removal of Rectal Foreign Bodies Using Tenaculum Forceps Under Endoscopic Assistance
The incidence of rectal foreign bodies is increasing by the day, though not as common as that of upper gastrointestinal foreign bodies. Various methods for removal of foreign bodies have been reported. Removal during endoscopy using endoscopic devices is simple and safe, but if the foreign body is too large to be removed by this method, other methods are required. We report two cases of rectal foreign body removal by a relatively simple and inexpensive technique. A 42-year-old man with a vibrator in the rectum was admitted due to inability to remove it by himself and various endoscopic methods failed. Finally, the vibrator was removed successfully by using tenaculum forceps under endoscopic assistance. Similarly, a 59-year-old man with a carrot in the rectum was admitted. The carrot was removed easily by using the same method as that in the previous case. The use of tenaculum forceps under endoscopic guidance may be a useful method for removal of rectal foreign bodies
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