Exploring emergency department 4-hour target performance and cancelled elective operations: a regression analysis of routinely collected and openly reported NHS trust data.

PubMed

Keogh, Brad; Culliford, David; Guerrero-Ludueña, Richard; Monks, Thomas

2018-05-24

To quantify the effect of intrahospital patient flow on emergency department (ED) performance targets and indicate if the expectations set by the National Health Service (NHS) England 5-year forward review are realistic in returning emergency services to previous performance levels. Linear regression analysis of routinely reported trust activity and performance data using a series of cross-sectional studies. NHS trusts in England submitting routine nationally reported measures to NHS England. 142 acute non-specialist trusts operating in England between 2012 and 2016. The primary outcome measures were proportion of 4-hour waiting time breaches and cancelled elective operations. Univariate and multivariate linear regression models were used to show relationships between the outcome measures and various measures of trust activity including empty day beds, empty night beds, day bed to night bed ratio, ED conversion ratio and delayed transfers of care. Univariate regression results using the outcome of 4-hour breaches showed clear relationships with empty night beds and ED conversion ratio between 2012 and 2016. The day bed to night bed ratio showed an increasing ability to explain variation in performance between 2015 and 2016. Delayed transfers of care showed little evidence of an association. Multivariate model results indicated that the ability of patient flow variables to explain 4-hour target performance had reduced between 2012 and 2016 (19% to 12%), and had increased in explaining cancelled elective operations (7% to 17%). The flow of patients through trusts is shown to influence ED performance; however, performance has become less explainable by intratrust patient flow between 2012 and 2016. Some commonly stated explanatory factors such as delayed transfers of care showed limited evidence of being related. The results indicate some of the measures proposed by NHS England to reduce pressure on EDs may not have the desired impact on returning services to previous performance levels. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Endoscopic submucosal dissection for early gastric cancer on the lesser curvature in upper third of the stomach is a risk factor for postoperative delayed gastric emptying.

PubMed

Yoshizaki, Tetsuya; Obata, Daisuke; Aoki, Yasuhiro; Okamoto, Norihiro; Hashimura, Hiroki; Kano, Chise; Matsushita, Megumi; Kanamori, Atsushi; Matsumoto, Kei; Tsujimae, Masahiro; Momose, Kenji; Eguchi, Takaaki; Okuyama, Shunsuke; Yamashita, Hiroshi; Fujita, Mikio; Okada, Akihiko

2018-02-07

Advances in Endoscopic submucosal dissection (ESD) technology have established ESD for early gastric cancer as a safe and stable technique. However, ESD may induce delayed gastric emptying and the cause of food residue retention in the stomach after ESD is not clear. This study aimed to clarify risk factors for delayed gastric emptying with food retention after gastric ESD. We retrospectively examined for food residue in the stomach 1 week after ESD was performed for early gastric carcinoma at Osaka Saiseikai Nakatsu Hospital from February 2008 to November 2016. Food residue was observed in 68 (6.1%) of 1114 patients who underwent gastric ESD. The percentage of lesions located on the lesser curvature of the upper third of the stomach was 45.6% (31/68) in the food residue group and 3.5% (37/1046) in the non-food residue group, which was significantly different (P < 0.01). Multivariate logistic regression analysis revealed that lesions on the lesser curvature of the upper third of the stomach (Odds ratio [OR] 23.31, 95% confidence interval [CI] 12.60-43.61, P < 0.01), post-ESD bleeding (OR 4.25, 95%CI 1.67-9.80, P < 0.01), submucosal invasion (OR 2.80, 95%CI 1.34-5.63, P < 0.01), and age over 80 years (OR 2.34, 95%CI 1.28-4.22, P < 0.01) were independent risk factors for food retention after gastric ESD. Of the 68 patients, 3 had food residue in the stomach on endoscopic examination for follow-up observation after the ESD ulcer had healed. Delayed gastric emptying with food retention after gastric ESD was associated with lesions located in the lesser curvature of the upper stomach, submucosal invasion of the lesion, age older than 80 years, and post-ESD bleeding, though it was temporary in most cases.

Performance and bacterial diversity of biotrickling filters filled with conductive packing material for the treatment of toluene.

PubMed

Wu, Hao; Guo, Chunyu; Yin, Zhenhao; Quan, Yue; Yin, Chengri

2018-06-01

Toluene has high toxicity and mutagenicity, thus, the removal of toluene from air is necessary. In this study, two biotrickling filters (BTFs) were constructed and packed with conductive packing material to treat toluene waste gas. BTF-O exhibited good toluene removal performance even under high toluene inlet concentration, and over 80% of removal efficiency was observed. The elimination capacity reached 120.1 g/m 3  h corresponding to an inlet concentration of 2.259 g/m 3 under 61.5 s of empty bed retention time. During toluene biodegradation, the output voltage was observed in BTF-O and BTF-E, moreover BTF-E also showed slight power storage capacity. The applied voltage inhibited toluene removal and affected the bacterial community. The predominant bacterial genera in BTF-O were Acidovorax, Rhodococcus, Hydrogenophaga, Brevundimonas, Arthrobacter, Pseudoxanthomonas, Devosia, Gemmobacter, Rhizobium, Dokdonella and Pseudomonas. Genera Xanthobacter and Pelomonas accounted for the main bacterial community in BTF-E. Copyright © 2018 Elsevier Ltd. All rights reserved.

Municipal-wastewater treatment using upflow-anaerobic filters.

PubMed

Manariotis, loannis D; Grigoropoulos, Sotirios G

2006-03-01

Three 12.5-L upflow-anaerobic filters (AF), with ceramic-saddle, plastic-ring, and crushed-stone packing, were used to evaluate the sustained treatment of municipal wastewater. The reactors were initially fed dogfood-fortified wastewater and then raw municipal wastewater, and operated at 25.4 degrees C (32 months) and 15.5 degrees C (2 months). During 23 months, the AF units treated municipal wastewater (mean chemical oxygen demand [COD] 442 mg/L and total suspended solids [TSS] 247 mg/L), the hydraulic retention time (HRT) ranged from 3.1 to 0.30 d (empty bed), and the organic loading rate ranged from 0.115 to 1.82 kg COD/m3d. At the higher temperature and an HRT (void volume) of 1.0 d, COD and TSS removals ranged from 74 to 79% and 95 to 96%, respectively; however, efficiencies declined substantially at HRT values less than 0.4 d. Reactor performance, under the same hydraulic and organic loadings, deteriorated with time and was adversely affected by lower temperature.

Integrated nitrogen removal biofilter system with ceramic membrane for advanced post-treatment of municipal wastewater.

PubMed

Son, Dong-Jin; Yun, Chan-Young; Kim, Woo-Yeol; Zhang, Xing-Ya; Kim, Dae-Gun; Chang, Duk; Sunwoo, Young; Hong, Ki-Ho

2016-12-01

The pre-denitrification biofilm process for nitrogen removal was combined with ceramic membrane with pore sizes of 0.05-0.1 µm as a system for advanced post-treatment of municipal wastewater. The system was operated under an empty bed hydraulic retention time of 7.8 h, recirculation ratio of 3, and transmembrane pressure of 0.47 bar. The system showed average removals of organics, total nitrogen, and solids as high as 93%, 80%, and 100%, respectively. Rapid nitrification could be achieved and denitrification was performed in the anoxic filter without external carbon supplements. The residual particulate organics and nitrogen in effluent from biofilm process could be also removed successfully through membrane filtration and the removal of total coliform was noticeably improved after membrane filtration. Thus, a system composed of the pre-denitrification biofilm process with ceramic membrane would be a compact and flexible option for advanced post-treatment of municipal wastewater.

Biofiltration of asphalt emissions: Full-scale operation treating off-gases from polymer-modified asphalt production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cook, L.L.; Gostomski, P.A.; Apel, W.A.

1999-09-30

In response to complaints from nearby residents, a biofilter was designed, installed, and tested for treating odors in one of three odorous emission streams from an asphalt plant producing polymer-modified asphalt. Hydrogen sulfide (H{sub 2}S) was determined to be the most prevalent gaseous reduced sulfur compound and was detected in the emission stream only when polymer material was being added to raw asphalt. Emission stream H{sub 2}S concentrations were quite variable, ranging from 16 to approximately 30,000 ppm (v/v) and considered the likely compound contributing most to the plant's odor complaints. The biofilter was effective in controlling odor from themore » production process and removed an overall average of 65% of the H{sub 2}S during polymer addition, and for H{sub 2}S concentrations less than 400 ppmv, removal averaged 98%. These removal efficiencies reflect data from the biofilter operating at 2.5-minute empty bed residence time in 1996 and a 6.1-minute empty bed residence time in 1997. The biofilter's bed became increasingly acidified during the plant's 1997 operating season producing a pH gradient through the bed ranging from a high of 6.6 to a low of 3.1. The bed medium moisture content remained constant at about 60% (wet weight basis), but changes were observed in the water potential: no correlation to performance was determined. Changes in the microbial community reflected the bed acidification trend, with acidophiles becoming generally more numerous in the bed's deeper portions and in the mid to late season when the bed was most acidified. Bed acidification did not impact the biofilter's H{sub 2}S removal efficiency.« less

Empty threat: Hospitals could see more vacancies as demand for outpatient care grows and financial pressure builds to curb inpatient admissions.

PubMed

Evans, Melanie

2012-03-26

Markets with too many hospital beds could see trouble as providers seek to control spending and avoid expensive hospitalizations. "You'll need a lot fewer hospitals and hospital beds" because providers will do more to keep patients healthy enough not to need them, says Frank Trembulak, of Geisinger Health System.

Specific food structures supress appetite through reduced gastric emptying rate

PubMed Central

Rafiee, Hameed; Malcolm, Paul; Salt, Louise; van Aken, George

2013-01-01

The aim of this study was to determine the extent to which gastric layering and retention of a meal could be used to reduce appetite using the same caloric load. Liquid (control) and semi-solid (active) meals were produced with the same protein, fat, carbohydrate, and mass. These were fed to 10 volunteers on separate days in a crossover study, and subjective appetite ratings, gastric contents, and plasma cholecystokinin (CCK) were assessed over a period of 3 h. The active meal showed food boluses in the stomach persisting for ∼45 min, slower emptying rates, and lower plasma CCK levels over the first hour. After the first hour, both gastric emptying rates and plasma CCK levels were similar for both systems and slightly increased compared with the unfed situation. Despite the lower plasma CCK levels for the active meal over the first hour, this meal reduced appetite more than the control meal over the 3 h of the study. For a moderately increased plasma CCK level in the fed state, appetite was correlated with the volume of gastric contents rather than gastric emptying rates or plasma CCK. This suggests that enhanced gastric retention was the key factor in decreasing appetite and was probably mediated by a combination of intestinal nutrient sensing and increased viscosity in the stomach. PMID:23578786

An Alternate, Egg-Free Radiolabeled Meal Formulation for Gastric-Emptying Scintigraphy.

PubMed

Garrigue, Philippe; Bodin-Hullin, Aurore; Gonzalez, Sandra; Sala, Quentin; Guillet, Benjamin

2017-07-01

Tc-radiolabeled scrambled eggs (SEs) are most often used as the ingested solid phase for gastric-emptying scintigraphy, leading egg-reluctant patients to avoid the examination. We formulated and validated 2 egg-free alternate meals, in the absence of any commercialized formulation: chocolate mug cake (MC) and scrambled tofu (ST). Six healthy volunteers underwent gastric-emptying scintigraphy after ingesting Tc-radiolabeled MC, ST, or SE. Gastric retention indexes did not change significantly between formulations (% of overtime variation to SE: MC 7.75% ± 7.1%, ST 7.17% ± 5.8%; P = 0.6618, not statistically significant), suggesting MC and ST as interesting egg-free alternatives.

Simple prostatectomy

MedlinePlus

... if you have: Problems emptying your bladder (urinary retention) Frequent urinary tract infections Frequent bleeding from the ... to internal organs Erection problems (impotence) Loss of sperm fertility ( infertility ) Passing semen back up into the ...

Effect of large wood retention at check dams on sediment continuity

NASA Astrophysics Data System (ADS)

Schmocker, Lukas; Schalko, Isabella; Weitbrecht, Volker

2017-04-01

Large wood transport during flood events may seriously increase the damage potential due to accumulations at river infrastructures. The large wood is therefore mostly retained upstream of populated areas using retention structures that often combine a check dam with a debris rack. One disadvantages of this structures is, that the bed-load gets retained along with the wood. Especially if large wood blocks the rack early during a flood event, sediment continuity is completely interrupted. This may lead to severe bed erosion downstream of the check dam. So far, no common design to retain large wood but maintain sediment continuity is available. One attempt to separate the large wood from the bed-load was made with the large wood retention structure at River Sihl in Zürich, Switzerland. The retention of the large wood occurs in a bypass channel located along the main river. The bypass is located at an outer river bend, where a separation of bed-load and large wood results due to the secondary currents induced by the river curvature. Large wood floats towards the outer bend due to inertia and the secondary currents whereas bed-load remains at the inner bend. The bypass is separated by a side weir from the main river to ensure that the bed-load remains in the river during bed forming discharges and flood events. New model test are currently carried out at the Laboratory of Hydraulics, Hydrology, and Glaciology (VAW) of ETH Zurich, where sediment continuity should be achieved using an inclined rack. The rack is inclined in flow direction with a degree of 45° to 20°. First results show that the large wood deposits at the upper part of the rack whereas the lower part of the rack remains free for bed-load transport. Furthermore, the backwater rise for the inclined rack due to the accumulated wood is considerably reduced compared to a vertical rack, as a large part of the rack remains clear for the flow to pass. The findings of this studies help to understand the complex interaction between sediment and large wood at a check dam retention structure. Furthermore, new retention structures and rack designs are available, where sediment continuity can partially be maintained to reduce downstream bed erosion.

Confirmation of monod model for biofiltration of styrene vapors from waste flue gas.

PubMed

Dehghanzadeh, Reza; Roshani, Babak; Asadi, Mahzar; Fahiminia, Mohammad; Aslhashemi, Ahmad

2012-01-01

The objective of this research was to investigate the kinetic behavior of the biofil¬tration process for the removal of styrene. A three stage compost based biofilter was inoculated with thickened activated sludge. The reaction order rate constants were obtained from continuous experiments and used as the specific growth rate for the Monod equation. The measured concentration profiles show a linear dependence on the bed height in the biofilter at higher loadings, such as 75 and 45 g m-3 h-1. This is the condition of reaction limitation for a reaction with zero-order kinetics. From the experimental data, maximum elimination capac¬ity (ECmax) was estimated to be 44, 40 and 26 g m-3 h-1 at empty bed retention times (EBRTs) of 120, 60 and 30 s, respectively. However, at lower loadings, the measured concentration profile of the biofilter is one of exponential increase, which is the condition of both reaction and diffusion limitations for a reaction with zero-order kinetics. Maximum elimination capacities found from the experimental results were the same as Monod model predictions. Both the experimental re¬sults and the model predictions showed the influence of EBRT on the removal rate of styrene, particularly for the highest loading rate. In terms of the practical applications of the proposed models have the advantage of being simpler than Monod kinetics and Monod kinetics requires a numerical solution.

The surgical treatment of chronic gastric atony following Roux-Y diversion for alkaline reflux gastritis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vogel, S.B.; Woodward, E.R.

1989-06-01

Symptoms of severe nausea, vomiting, abdominal pain, and frequent bezoars, as well as objective gastric retention, can occur following Roux-Y biliary diversion for alkaline reflux gastritis. Medical therapy and prokinetic drugs have proven ineffective. This review evaluates 37 patients who underwent further gastric resection from 1979 to 1987 to improve gastric emptying and resolve symptoms. Fifteen patients underwent perioperative radionuclide solid-food gastric emptying studies. Seventy-three per cent (27 of 37 patients) of the patients who underwent further gastric resection (70% to 95%) had a satisfactory postoperative response. Twenty patients were graded Visick 1 or 2 and 7 Visick-3 patients, althoughmore » much improved, still had some symptoms of gastroparesis. Twenty-seven per cent (10 of 37 patients) failed to improve and underwent completion total gastrectomy. Overall, 70% of this group had almost complete resolution of their symptoms. Three of 10 patients were considered ''failures'' due to postprandial pain in 1 and early vasomotor dumping in 2. Of the 10 patients who failed initial revisional surgery, 7 underwent a 70% to 80% subtotal gastric resection (STG) and 3 patients underwent 85% to 95% extensive resection (EXT.G.). Of the 15 patients who underwent perioperative radionuclide evaluation, a mean two-hour gastric retention of 61.4% +/- 4% (SEM) decreased to 25% +/- 4% following further gastric resection. Eight patients were in the STG group and seven patients were in the EXT.G group. Following STG, mean two-hour gastric retention of 58.2% +/- 3.5% decreased to 38% +/- 3% (p less than 0.05). In seven patients who underwent EXT.G, mean two-hour retention of 65% +/- 4% decreased to 10% +/- 2.5% (p less than 0.005). EXT.G resulted in normal gastric emptying and few late failures.« less

Cystoscopy and Ureteroscopy

MedlinePlus

... urinary urgency—the inability to delay urination urinary retention —the inability to empty the bladder completely urinary ... Coordinating Committees Strategic Plans & Reports Research Areas FAQs Jobs at NIDDK Visit Us Contact Us News News ...

Urine culture - catheterized specimen

MedlinePlus

... you may feel pressure. If you have a urinary tract infection , you may have some pain when the catheter ... on their own If you might have a urinary tract infection If you cannot empty your bladder (urinary retention) ...

Percutaneous nerve evaluation (PNE) for treatment of non-obstructive urinary retention: urodynamic changes, placebo effects, and response rates.

PubMed

Sharifiaghdas, Farzaneh; Mirzaei, Mahboubeh; Ahadi, Babak

2014-03-04

To evaluate the results of percutaneous nerve evaluation (PNE) implantation in the treatment of non-obstructive urinary retention and report the changes in the urodynamic parameters. Patients with non-obstructive urinary retention or incomplete bladder emptying were included. All patients filled a 7 days voiding diary chart and underwent PNE for one week, and the patient was asked to record the second voiding diary chart and repeat urodynamic study in this period. Then the PNE lead was removed from the S3 foramen, but the connections remained fixed in place for another 3 days to exclude the placebo effects and the third voiding diary chart was completed by the patient. The patient wasn't aware of lead removal. Success was defined as, more than 50% improvement in at least one of the urinary tract symptoms. Forty five patients with a mean age of 37.1 years (ranged 9-83 years) were treated with PNE for refractory, non-obstructive urinary retention. Of study subjects 28 complained from complete urinary retention, and 17 had incomplete emptying. Of participants, 28 (62.2%) demonstrated greater than 50% improvement in the urinary symptoms. Urodynamic data, showed a statistically significant increase in maximum flow rate (8 ± 2.2 mL/sec to 16 ± 3.6 mL/sec, P = .06) and voided volume (35 mL to 187 mL, P = .032) in the responders. Any placebo effects in PNE have not been seen. Patients with complete non obstructive urinary retention were good responders to PNE. The placebo effect in sacral nerve stimulation was negligible.

Assessment of Gastric Emptying in Patients with Autoimmune Gastritis.

PubMed

Kalkan, Çağdaş; Soykan, Irfan; Soydal, Çiğdem; Özkan, Elgin; Kalkan, Emra

2016-06-01

Symptoms of patients with autoimmune gastritis are not specific, and some patients may present symptoms suggestive of delayed gastric emptying. This study aims to investigate whether any delay in gastric emptying of solid food exists in patients with autoimmune gastritis and, if so, to identify the factors that might affect delayed gastric emptying. A total of 165 patients (106 women) diagnosed as having autoimmune gastritis were analyzed by means of a gastric emptying test. All patients underwent a standardized scintigraphic gastric emptying study. Patients with delayed gastric emptying and normal gastric emptying tests were then compared by means of factors that might affect gastric emptying. Also 65 patients with functional dyspepsia who had a gastric emptying study constituted the control group. The median gastric emptying T ½ time was 127.43 min (min-max 50-953) for patients with AIG and 81 min (min-max 21-121.6) for functional dyspepsia patients (p < 0.001), and median percent retention at 2 h was 63.8 versus 20.2 (p < 0.001). In multivariate analysis, parameters that affected gastric emptying T ½ time were found as serum gastrin level (OR 1.002, 95 % CI 1.001-1.004, p < 0.001, chronic inflammation (OR 3.689, 95 % CI 1.44-9.39, p < 0.001), and increase in the degree of the atrophy of the gastric mucosa (OR 8.96, 95 % CI 2.98-26.93, p < 0.001). In patients with autoimmune gastritis, gastric emptying is generally delayed. Autoimmune gastritis is an important etiology to explain the finding of delayed gastric emptying on a radionuclide test. This new finding is likely to be relevant to clinicians when evaluating and initiating appropriate medical treatment for patients with autoimmune gastritis manifesting upper gastrointestinal symptoms.

Confirmation of Monod Model for Biofiltration of Styrene Vapors from Waste Flue Gas

PubMed Central

Dehghanzadeh, Reza; Roshani, Babak; Asadi, Mahzar; Fahiminia, Mohammad; AslHashemi, Ahmad

2012-01-01

Background: The objective of this research was to investigate the kinetic behavior of the biofil¬tration process for the removal of styrene. Methods: A three stage compost based biofilter was inoculated with thickened activated sludge. The reaction order rate constants were obtained from continuous experiments and used as the specific growth rate for the Monod equation. Results: The measured concentration profiles show a linear dependence on the bed height in the biofilter at higher loadings, such as 75 and 45 g m-3 h-1. This is the condition of reaction limitation for a reaction with zero-order kinetics. From the experimental data, maximum elimination capac¬ity (ECmax) was estimated to be 44, 40 and 26 g m-3 h-1 at empty bed retention times (EBRTs) of 120, 60 and 30 s, respectively. However, at lower loadings, the measured concentration profile of the biofilter is one of exponential increase, which is the condition of both reaction and diffusion limitations for a reaction with zero-order kinetics. Maximum elimination capacities found from the experimental results were the same as Monod model predictions. Both the experimental re¬sults and the model predictions showed the influence of EBRT on the removal rate of styrene, particularly for the highest loading rate. Conclusion: In terms of the practical applications of the proposed models have the advantage of being simpler than Monod kinetics and Monod kinetics requires a numerical solution. PMID:24688940

Biofiltration of Asphalt Emissions: Full-scale Operation Treating Off-gases from Polymer-modified Asphalt Production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cook, Lawrence Leslie; Apel, William Arnold; Gostomski, P. A.

2004-04-01

In response to complaints from nearby residents, a biofilter was designed, installed, and tested for treating odors in one of three odorous emission streams from an asphalt plant producing polymer-modified asphalt. Hydrogen sulfide (H2S) was determined to be the most prevalent gaseous reduced sulfur compound and was detected in the emission stream only when polymer material was being added to raw asphalt. Emission stream H2S concentrations we requite variable, ranging from 16 to approximately 30,000 ppm (v/v) and considered the likely compound contributing most to the plant's odor complaints. The biofilter was effective in controlling odor from the production processmore » and removed an overall average of 65% of the H2S during polymer addition, and for H2S concentrations less than 400 ppmv, re m oval averaged 98%. These removal efficiencies reflect data from the biofilter operating at 2.5-minute empty bed residence time in 1996 and a 6.1-minute empty bed residence time in 1997. The biofilter's bed became increasingly acidified during the plant's 1997 operating season producing a pH gradient through the bed ranging from a high of 6.6 to a low of 3.1. The bed medium moisture content remained constant at about 60% (wet weight basis), but changes were observed in the water potential: no correlation to performance was determined. Changes in the microbial community reflected the bed acidification trend, with acidophiles becoming gene rally more numerous in the bed's deeper portions and in the mid to late season when the bed was most acidified. Bed acidification did not impact the biofilter's H2S removal efficiency. Nearby residents we resurveyed and roughly half of the respondents indicated that the odor conditions had improved, one-third felt odor conditions were unchanged and the remaining 15% felt odor conditions were worse despite the fact that only one of three of the plant's odorous emission streams were treated by the biofilter. Plans are to implement biofiltration for odor control at all of the facility's emission points.« less

Characterization of reactive CaCO 3 crystallization in a fluidized bed reactor as a central process of direct air capture

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burhenne, Luisa; Giacomin, Caroline; Follett, Trevor

A laboratory-scale, fluidized-bed pellet reactor (BPR) was used to investigate a CaCO 3 crystallization process for the recovery of CO 2 in a Direct Air Capture (DAC) process. The BPR performance was validated against data from a pilot-scale unit. Subsequently, the pellet growth under process-relevant conditions was studied over a period of 144 h. The experimental results with the BPR, containing a bed of pellets sized between 0.65 and 0.84 mm, have shown that a calcium retention of 80% can be achieved at a fluidization velocity of 60 m h -1 and a calcium loading rate of 3 mol hmore » -1. This result is consistent with calcium retention observed at pilot scale operation and hence, results from the BPR are considered representative for the pilot scale unit. Starting with a bed of pellets sized between 0.15 and 0.5 mm, the average pellet growth rate, G, at the reactor bottom increased from 8.1E-10 to 11E–10 m s -1 at the onset and decreased to 4.9E–10 m s -1 over the course of a 144 h test. The calcium retention over the course the test showed the same trend (initial increase and final decrease) as the pellet growth rate. A theoretical bed growth model was developed and validated against data from the pilot scale and benchtop pellet reactors. The model was used to calculate the bed porosity and total pellet surface area in each control volume. Lastly, the pellet surface area growth at the bottom of the reactor reproduced the pellet growth and retention data trends.« less

Characterization of reactive CaCO 3 crystallization in a fluidized bed reactor as a central process of direct air capture

DOE PAGES

Burhenne, Luisa; Giacomin, Caroline; Follett, Trevor; ...

2017-10-25

A laboratory-scale, fluidized-bed pellet reactor (BPR) was used to investigate a CaCO 3 crystallization process for the recovery of CO 2 in a Direct Air Capture (DAC) process. The BPR performance was validated against data from a pilot-scale unit. Subsequently, the pellet growth under process-relevant conditions was studied over a period of 144 h. The experimental results with the BPR, containing a bed of pellets sized between 0.65 and 0.84 mm, have shown that a calcium retention of 80% can be achieved at a fluidization velocity of 60 m h -1 and a calcium loading rate of 3 mol hmore » -1. This result is consistent with calcium retention observed at pilot scale operation and hence, results from the BPR are considered representative for the pilot scale unit. Starting with a bed of pellets sized between 0.15 and 0.5 mm, the average pellet growth rate, G, at the reactor bottom increased from 8.1E-10 to 11E–10 m s -1 at the onset and decreased to 4.9E–10 m s -1 over the course of a 144 h test. The calcium retention over the course the test showed the same trend (initial increase and final decrease) as the pellet growth rate. A theoretical bed growth model was developed and validated against data from the pilot scale and benchtop pellet reactors. The model was used to calculate the bed porosity and total pellet surface area in each control volume. Lastly, the pellet surface area growth at the bottom of the reactor reproduced the pellet growth and retention data trends.« less

Device and method for treatment of gases

DOEpatents

Vegge, Olaf Trygve; Brinch, Jon Christian

2007-01-30

The device and method of the present invention employs a column having a gas inlet in its lower part and a gas outlet in its upper part. Carbon particles are introduced into the column through a supply pipe. The supply pipe is movable so that by manipulating the height of the supply pipe in conjunction with discharging particulate matter through the column, the height of the bed of particulate matter in the column can be adjusted so that the retention time of the off gas in the particulate bed is constant. By maintaining a constant retention time of the off gas in the bed, complete conversion of the off gas is achieved.

Aerobic digestion of starch wastewater in a fluidized bed bioreactor with low density biomass support.

PubMed

Rajasimman, M; Karthikeyan, C

2007-05-08

A solid-liquid-gas, multiphase, fluidized bed bioreactor with low density particles was used in this study to treat the high organic content starch industry wastewater. The characteristics of starch wastewater were studied. It shows high organic content and acidic nature. The performance of a three phase fluidized bed bioreactor with low density biomass support was studied under various average initial substrate concentrations, by varying COD values (2250, 4475, 6730 and 8910 mg/L) and for various hydraulic retention times (8, 16, 24, 32 and 40 h) based on COD removal efficiency. The optimum bed height for the maximum COD reduction was found to be 80 cm. Experiments were carried out in the bioreactor at an optimized bed height, after the formation of biofilm on the surface of low-density particles (density=870 kg/m(3)). Mixed culture obtained from the sludge, taken from starch industry effluent treatment plant, was used as the source for microorganisms. From the results it was observed that increase in initial substrate concentration leads to decrease in COD reduction and COD reduction increases with increase in hydraulic retention time. The optimum COD removal of 93.8% occurs at an initial substrate concentration of 2250 mg/L and for the hydraulic retention time of 24h.

Ammoniacal nitrogen and COD removal from semi-aerobic landfill leachate using a composite adsorbent: fixed bed column adsorption performance.

PubMed

Halim, Azhar Abdul; Aziz, Hamidi Abdul; Johari, Megat Azmi Megat; Ariffin, Kamar Shah; Adlan, Mohd Nordin

2010-03-15

The performance of a carbon-mineral composite adsorbent used in a fixed bed column for the removal of ammoniacal nitrogen and aggregate organic pollutant (COD), which are commonly found in landfill leachate, was evaluated. The breakthrough capacities for ammoniacal nitrogen and COD adsorption were 4.46 and 3.23 mg/g, respectively. Additionally, the optimum empty bed contact time (EBCT) was 75 min. The column efficiency for ammoniacal nitrogen and COD adsorption using fresh adsorbent was 86.4% and 92.6%, respectively, and these values increased to 90.0% and 93.7%, respectively, after the regeneration process. (c) 2009 Elsevier B.V. All rights reserved.

Engineering empty space between Si nanoparticles for lithium-ion battery anodes.

PubMed

Wu, Hui; Zheng, Guangyuan; Liu, Nian; Carney, Thomas J; Yang, Yuan; Cui, Yi

2012-02-08

Silicon is a promising high-capacity anode material for lithium-ion batteries yet attaining long cycle life remains a significant challenge due to pulverization of the silicon and unstable solid-electrolyte interphase (SEI) formation during the electrochemical cycles. Despite significant advances in nanostructured Si electrodes, challenges including short cycle life and scalability hinder its widespread implementation. To address these challenges, we engineered an empty space between Si nanoparticles by encapsulating them in hollow carbon tubes. The synthesis process used low-cost Si nanoparticles and electrospinning methods, both of which can be easily scaled. The empty space around the Si nanoparticles allowed the electrode to successfully overcome these problems Our anode demonstrated a high gravimetric capacity (~1000 mAh/g based on the total mass) and long cycle life (200 cycles with 90% capacity retention). © 2012 American Chemical Society

Empty Beds: Indian Student Health at Sherman Institute, 1902-1922.

ERIC Educational Resources Information Center

Keller, Jean A.

As one of the last nonreservation boarding schools built for American Indian students in the United States, Sherman Institute (Riverside, California) benefited from lessons learned about student health from earlier boarding schools. Excessive student morbidity and mortality at early boarding schools had resulted in a lasting perception of these…

Branched-chain amino acid supplementation during bed rest: effect on recovery

NASA Technical Reports Server (NTRS)

Stein, T. P.; Donaldson, M. R.; Leskiw, M. J.; Schluter, M. D.; Baggett, D. W.; Boden, G.

2003-01-01

Bed rest is associated with a loss of protein from the weight-bearing muscle. The objectives of this study are to determine whether increasing dietary branched-chain amino acids (BCAAs) during bed rest improves the anabolic response after bed rest. The study consisted of a 1-day ambulatory period, 14 days of bed rest, and a 4-day recovery period. During bed rest, dietary intake was supplemented with either 30 mmol/day each of glycine, serine, and alanine (group 1) or with 30 mmol/day each of the three BCAAs (group 2). Whole body protein synthesis was determined with U-(15)N-labeled amino acids, muscle, and selected plasma protein synthesis with l-[(2)H(5)]phenylalanine. Total glucose production and gluconeogenesis from alanine were determined with l-[U-(13)C(3)]alanine and [6,6-(2)H(2)]glucose. During bed rest, nitrogen (N) retention was greater with BCAA feeding (56 +/- 6 vs. 26 +/- 12 mg N. kg(-1). day(-1), P < 0.05). There was no effect of BCAA supplementation on either whole body, muscle, or plasma protein synthesis or the rate of 3-MeH excretion. Muscle tissue free amino acid concentrations were increased during bed rest with BCAA (0.214 +/- 0.066 vs. 0.088 +/- 0.12 nmol/mg protein, P < 0.05). Total glucose production and gluconeogenesis from alanine were unchanged with bed rest but were significantly reduced (P < 0.05) with the BCAA group in the recovery phase. In conclusion, the improved N retention during bed rest is due, at least in part, to accretion of amino acids in the tissue free amino acid pools. The amount accreted is not enough to impact protein kinetics in the recovery phase but does improve N retention by providing additional essential amino acids in the early recovery phase.

Jejunal pouch with nerve preservation and interposition after total gastrectomy.

PubMed

Kobayashi, I; Ohwada, S; Ohya, T; Yokomori, T; Iesato, H; Morishita, Y

1998-01-01

In this paper, we describe operative technique details and our results with a modified technique for jejunal pouch formation and interposition after total gastrectomy, with an overall aim to achieve results superior to jejunal pouch and Roux-en-Y reconstruction, as reported in the literature. Following total gastrectomy, the jejunum was divided approximately 20 cm distal to the ligament of Treitz. Marginal vessels were not divided in order to preserve the nerves in the 50 cm of distal jejunum which would be used for pouch construction. The pouch was constructed using a linear stapler (Endo GiA, United States Surgical Corp., Norwalk, Conn). A total of 15 gastric cancer patients underwent construction of a nerve-preserving jejunal pouch and interposition following total gastrectomy. None of the patients experienced postoperative complications due to pouch construction. Additionally, discomforts such as dumping or stagnation were not observed. Mild reflux esophagitis occurred in five of the 15 patients and was resolved by oral administration of camostat mesilate. Six months after surgery, the average patient's diet volume and body weight had gradually increased to 79% and 86%, respectively, of the presurgical levels. A dual phase, dual isotope radionucleid pouch emptying study was also performed six months after surgery. The intra-pouch RI retention rate was 47% for liquid food and 53% for solid food 120 minutes after intake. The emptying rate was slower for both solid and liquid food, as compared with healthy individuals. The pouch-emptying test demonstrated a satisfactory retention capacity and an acceptable emptying time as a gastric substitute. The patients who underwent gastric reconstruction with a nerve-preserving jejunal pouch with interposition have experienced a reasonably good quality of life.

Performance of the fixed-bed of granular activated carbon for the removal of pesticides from water supply.

PubMed

Alves, Alcione Aparecida de Almeida; Ruiz, Giselle Louise de Oliveira; Nonato, Thyara Campos Martins; Müller, Laura Cecilia; Sens, Maurício Luiz

2018-02-26

The application of a fixed bed adsorption column of granular activated carbon (FBAC-GAC), in the removal of carbaryl, methomyl and carbofuran at a concentration of 25 μg L -1 for each carbamate, from the public water supply was investigated. For the determination of the presence of pesticides in the water supply, the analytical technique of high-performance liquid chromatography with post-column derivatization was used. Under conditions of constant diffusivity, the FBAC-GAC was saturated after 196 h of operation on a pilot scale. The exhaust rate of the granular activated carbon (GAC) in the FBAC-GAC until the point of saturation was 0.02 kg GAC m -3 of treated water. By comparing a rapid small-scale column test and FBAC-GAC, it was confirmed that the predominant intraparticle diffusivity in the adsorption column was constant diffusivity. Based on the results obtained on a pilot scale, it was possible to estimate the values to be applied in the FBAC-GAC (full scale) to remove the pesticides, which are particle size with an average diameter of 1.5 mm GAC; relationship between the internal diameter of the column and the average diameter of GAC ≥50 in order to avoid preferential flow near the adsorption column wall; surface application rate 240 m 3  m -2  d -1 and an empty bed contact time of 3 min. BV: bed volume; CD: constant diffusivity; EBCT: empty bed contact time; FBAC-GAC: fixed bed adsorption column of granular activated carbon; GAC: granular activated carbon; MPV: maximum permitted values; NOM: natural organic matter; PD: proportional diffusivity; pH PCZ : pH of the zero charge point; SAR: surface application rate; RSSCT: rapid small-scale column test; WTCS: water treated conventional system.

Oxidation of hydrogen sulfide in biogas using dissolved oxygen in the extreme acidic biofiltration operation.

PubMed

Charnnok, Boonya; Suksaroj, Thunwadee; Boonswang, Piyarat; Chaiprapat, Sumate

2013-03-01

This work aimed to investigate the interactive effects of empty bed retention time (EBRT), specific hydraulic loading rate (q) and initial pH (pHi) of the aerated recirculating liquid to remove H2S in extreme acidic biofiltration. Biogas containing H2S 6395±2309ppm and CH4 79.8±2.5% was fed to the biofilter as pH of the high dissolved oxygen recirculating liquid swung between pHi to 0.5. Response surface methodology was employed that gave the H2S removal relationship model with R(2) 0.882. The predicted highest H2S removal within the studied parameter ranges was 94.7% at EBRT 180.0s, q 4.0m(3)/m(2)/h and pHi 3.99. Results from separate runs at a random condition were not statistically different from the model prediction, signifying a validity of the model. Additionally, CH4 content in the exit biogas increased by 4.7±0.4%. Acidithiobacullus sp. predominance in the consortia of this extreme acidic condition was confirmed by DGGE. Copyright © 2012 Elsevier Ltd. All rights reserved.

Multiseed liposomal drug delivery system using micelle gradient as driving force to improve amphiphilic drug retention and its anti-tumor efficacy.

PubMed

Zhang, Wenli; Li, Caibin; Jin, Ya; Liu, Xinyue; Wang, Zhiyu; Shaw, John P; Baguley, Bruce C; Wu, Zimei; Liu, Jianping

2018-11-01

To improve drug retention in carriers for amphiphilic asulacrine (ASL), a novel active loading method using micelle gradient was developed to fabricate the ASL-loaded multiseed liposomes (ASL-ML). The empty ML were prepared by hydrating a thin film with empty micelles. Then the micelles in liposomal compartment acting as 'micelle pool' drove the drug to be loaded after the outer micelles were removed. Some reasoning studies including critical micelle concentration (CMC) determination, influencing factors tests on entrapment efficiency (EE), structure visualization, and drug release were carried out to explore the mechanism of active loading, ASL location, and the structure of ASL-ML. Comparisons were made between pre-loading and active loading method. Finally, the extended drug retention capacity of ML was evaluated through pharmacokinetic, drug tissue irritancy, and in vivo anti-tumor activity studies. Comprehensive results from fluorescent and transmission electron microscope (TEM) observation, encapsulation efficiency (EE) comparison, and release studies demonstrated the formation of ML-shell structure for ASL-ML without inter-carrier fusion. The location of drug mainly in inner micelles as well as the superiority of post-loading to the pre-loading method , in which drug in micelles shifted onto the bilayer membrane was an additional positive of this delivery system. It was observed that the drug amphiphilicity and interaction of micelles with drug were the two prerequisites for this active loading method. The extended retention capacity of ML has been verified through the prolonged half-life, reduced paw-lick responses in rats, and enhanced tumor inhibition in model mice. In conclusion, ASL-ML prepared by active loading method can effectively load drug into micelles with expected structure and improve drug retention.

Hydrogen sulfide removal from air by Acidithiobacillus thiooxidans in a trickle bed reactor.

PubMed

Ramirez, M; Gómez, J M; Cantero, D; Páca, J; Halecký, M; Kozliak, E I; Sobotka, M

2009-09-01

A strain of Acidithiobacillus thiooxidans immobilized in polyurethane foam was utilized for H(2)S removal in a bench-scale trickle-bed reactor, testing the limits of acidity and SO(4) (2-) accumulation. The use of this acidophilic strain resulted in remarkable stability in the performance of the system. The reactor maintained a >98-99 % H(2)S removal efficiency for c of up to 66 ppmv and empty bed residence time 98 % H(2)S was achieved under steady-state conditions, over the pH range of 0.44-7.30. Despite the accumulation of acidity and SO(4) (2-) (up to 97 g/L), the system operated without inhibition.

Gastric emptying of solids is markedly delayed when meals are fried.

PubMed

Benini, L; Brighenti, F; Castellani, G; Brentegani, M T; Casiraghi, M C; Ruzzenente, O; Sembenini, C; Pellegrini, N; Caliari, S; Porrini, M

1994-11-01

We studied the effect of heat-treated fats on gastric emptying. Eight healthy asymptomatic volunteers (five males; age 28-41 years) ate on different days and in random order two meals identical in contents (pasta, tomato, beef, olive oil, carrots, orange, water; 870 kcal males, 700 kcal females; 47% of calories from carbohydrate, 36% from fat, 17% from protein), but cooked differently (fats fried or not). Ultrasound measurement of antral diameters was used to calculate basal antral section, its maximal dilation after the meal, the time necessary for total emptying, and the percent retention at hourly intervals. No difference was found in basal and maximal antral diameters after the two meals. On the contrary, total gastric emptying was significantly delayed after the fried meal [317.1 (24.12) vs 226.7 (18.4) min, mean (1 SEM); P < 0.002]. A significantly greater percentage of maximal antral distension was still present between 120 and 240 min after the fried meal. The glycemic response and hunger feeling were the same after the two meals, whereas there was a longer persistence of satiety and epigastric fullness after the fried meal. In conclusion, gastric emptying can be influenced not only by the meal content, but also by the way it is cooked.

Caring holistically within new managerialism.

PubMed

Wong, Woon Hau

2004-03-01

This article explains the attempts of nurses to practice humanistic, holistic care in line with their professionalizing strategy. Ideally, the intention of nurses is to broaden their concerns beyond the physiological needs of patients, thereby circumventing biomedical control over their work. However, the author argues that resource constraints, and the coalescing of biomedical and managerial definitions of patients, suggest that holistic notions of care are subjected to a new form of calculus and normalizing technology. Critically, nurses are more preoccupied with the day-to-day struggle to free up resources for healthcare, in particular bed spaces, and to pre-empt the problem of bed blocking. Such work suggests that the "emptying of beds" is not just a symbol of accomplishment for nursing work. From the governmentality theory of Foucault, the administration of "beds" has become part of the managerial power/knowledge discourse and an instrument for making nurses toe the financial bottom-line.

Verbal Cues Facilitate Memory Retrieval during Infancy

ERIC Educational Resources Information Center

Hayne, Harlene; Herbert, Jane

2004-01-01

In three experiments, 18-month-olds were tested in a deferred imitation paradigm. Some infants received verbal information during the demonstration and at the time of the test (full narration), and some did not (empty narration). When tested after a 4-week delay, infants given full narration exhibited superior retention relative to infants given…

24. VIEW SHOWING WASTE GATES ON GRAND CANAL AT JUNCTION ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

24. VIEW SHOWING WASTE GATES ON GRAND CANAL AT JUNCTION WITH OLD CROSSCUT NE/4, Sec. 7, TIN, R4E; LOOKING WEST. OLD CROSSCUT CANAL ENTERS FROM RIGHT. WASTE GATE ON LEFT EMPTIES INTO SALT RIVER BED Photographer: Kevin Kreisel-Coons, May 1990 - Grand Canal, North side of Salt River, Tempe, Maricopa County, AZ

H2 production with anaerobic sludge using activated-carbon supported packed-bed bioreactors.

PubMed

Lee, Kuo-Shing; Lo, Yung-Sheng; Lo, Yung-Chung; Lin, Ping-Jei; Chang, Jo-Shu

2003-01-01

Packed-bed bioreactors containing activated carbon as support carrier were used to produce H2 anaerobically from a sucrose-limiting medium while acclimated sewage sludge was used as the H2 producer. The effects of bed porosity (epsilon(b)) and substrate loading rate on H2 fermentation were examined using packed beds with epsilon(b) of 70-90% being operated at hydraulic retention times (HRT) of 0.5-4 h. Higher epsilon(b) and lower HRT favored H2 production. With 20 g COD l(-1) of sucrose in the feed, the optimal H2 production rate (7.4 l h(-1) l(-1)) was obtained when the bed with epsilon(b) = 90% was operated at HRT = 0.5 h. Flocculation of cells enhanced the retention of sludge for stable operations of the bioreactor at low HRTs. The gas products resulting from fermentative H2 production consisted of 30-40% H2 and 60-70% CO2. Butyric acid was the primary soluble product, followed by propionic acid and valeric acid.

Atrial stretch delays gastric emptying of liquids in awake rats.

PubMed

Palheta, R C; Silva, M T B; Barbosa, H L G; Pinheiro, A D N; Cardoso, K V V; Graça, J R V; Magalhães, P J C; Oliveira, R B; Santos, A A

2013-03-21

We previously reported that mechanical atrial stretch (AS) by balloon distention increased gastric tonus in anesthetized rats. The present study evaluated the effect of AS on the gastric emptying of a liquid test meal in awake rats and its underlying neural mechanisms. Anesthetized male rats received a balloon catheter into the right atrium and a gastrostomy cannula. The next day, mean arterial pressure (MAP), heart rate (HR), central venous pressure (CVP), and cardiac output (CO) were continuously monitored. After the first 20min of monitoring (basal interval), the balloon was either distended or not (control) with 30, 50, or 70μl saline for 5min. Fifteen minutes later, the rats received the test meal (glucose solution with phenol red), and fractional gastric dye retention was determined 10, 20, or 30min later. Heart rate and CVP values were transiently increased by 50 or 70μl AS but not 30μl AS, whereas gastric emptying was slower after 30, 50, or 70μl AS than after sham distention. Subdiaphragmatic vagotomy or splanchnicotomy+celiac ganglionectomy and capsaicin, ondansetron, hexamethonium, L-NAME, and glibenclamide treatment prevented the AS-induced delay in gastric emptying, whereas atropine and guanethidine treatment failed to prevent it. Atrial stretch inhibited the gastric emptying of liquid via non-adrenergic and non-cholinergic pathways that activate nitric oxide-K(+)ATP channels. Copyright © 2013 Elsevier Inc. All rights reserved.

Removal of p-xylene from an air stream in a hybrid biofilter.

PubMed

Wu, Dan; Quan, Xie; Zhao, Yazhi; Chen, Shuo

2006-08-21

Biofiltration of an air stream containing p-xylene has been studied in a laboratory hybrid biofilter packed with a mixture of mature pig compost, forest soil and the packing material which was made of polyethylene (PE) and used in the moving bed biological reactor (MBBR) in wastewater treatment. Three flow rates, 9.17, 19.87 and 40.66 m(3)m(-2)h(-1), were investigated for p-xylene inlet concentration ranging from 0.1 to 3.3 g m(-3). A high elimination capacity of 80 g m(-3)h(-1) corresponding to removal efficiency of 96% was obtained at a flow rate of 9.17 m(3)m(-2)h(-1) (empty bed residence time of 132 s). At a flow rate of 40.66 m(3)m(-2)h(-1) (empty bed residence time of 30s), the maximum elimination capacity for p-xylene was 40 g m(-3)h(-1) and removal efficiencies were in the range of 47-100%. The production of carbon dioxide (P(CO(2))) is proportional to elimination capacity (EC) and the linear relation was formulated as P(CO(2))=1.65EC+15.58. Stable pH values ranging from 6.3 to 7.6 and low pressure drop values less than 0.2 cm H(2)O (19.6 Pa) of packing media in compost-based biofilter of hybrid biofilter were observed, which avoided acidification and compaction of packing media and sustained the activity of microorganism populations.

Capacity and Utilization in Health Care: The Effect of Empty Beds on Neonatal Intensive Care Admission

PubMed Central

Freedman, Seth

2016-01-01

Because geographic variation in medical care utilization is jointly determined by both supply and demand, it is difficult to empirically estimate whether capacity itself has a causal impact on utilization in health care. In this paper, I exploit short-term variation in Neonatal Intensive Care Unit (NICU) capacity that is unlikely to be correlated with unobserved demand determinants. I find that available NICU beds have little to no effect on NICU utilization for the sickest infants, but do increase utilization for those in the range of birth weights where admission decisions are likely to be more discretionary. PMID:27942353

Water quality and quantity investigation of green roofs in a dry climate.

PubMed

Beecham, S; Razzaghmanesh, M

2015-03-01

Low-energy pollutant removal strategies are now being sought for water sensitive urban design. This paper describes investigations into the water quality and quantity of sixteen, low-maintenance and unfertilized intensive and extensive green roof beds. The factors of Slope (1° and 25°), Depth (100 mm and 300 mm), Growing media (type A, type B and type C) and Species (P1, P2 and P3) were randomized according to a split-split plot design. This consisted of twelve vegetated green roof beds and four non-vegetated beds as controls. Stormwater runoff was collected from drainage points that were installed in each area. Samples of run-off were collected for five rainfall events and analysed for water retention capacity and the water quality parameters of NO₂, NO₃, NH₄, PO₄, pH, EC, TDS, Turbidity, Na, Ca, Mg and K. The results indicated significant differences in terms of stormwater water quality and quantity between the outflows of vegetated and non-vegetated systems. The water retention was between 51% and 96% and this range was attributed to the green roof configurations in the experiment. Comparing the quality of rainfall as inflow, and the quality of runoff from the systems showed that green roofs generally acted as a source of pollutants in this study. In the vegetated beds, the intensive green roofs performed better than the extensive beds with regard to outflow quality while in the non-vegetated beds, the extensive beds performed better than intensive systems. This highlights the importance of vegetation in improving water retention capacity as well as the role of vegetation in enhancing pollutant removal in green roof systems. In addition growing media with less organic matter had better water quality performance. Comparison of these results with national and international standards for water reuse confirmed that the green roof outflow was suitable for non-potable uses such as landscape irrigation and toilet flushing. Copyright © 2014 Elsevier Ltd. All rights reserved.

Performance study of biofilter developed to treat H2S from wastewater odour

PubMed Central

Omri, Ilhem; Aouidi, Fethia; Bouallagui, Hassib; Godon, Jean-Jacques; Hamdi, Moktar

2013-01-01

Biofiltration is an efficient biotechnological process used for waste gas abatement in various industrial processes. It offers low operating and capital costs and produces minimal secondary waste streams. The objective of this study was to evaluate the performance of a pilot scale biofilter in terms of pollutants’ removal efficiencies and the bacterial dynamics under different inlet concentrations of H2S. The treatment of odourous pollutants by biofiltration was investigated at a municipal wastewater treatment plant (WWTP) (Charguia, Tunis, Tunisia). Sampling and analyses were conducted for 150 days. Inlet H2S concentration recorded was between 200 and 1300 mg H2S.m−3. Removal efficiencies reached 99% for the majority of the running time at an empty bed retention time (EBRT) of 60 s. Heterotrophic bacteria were found to be the dominant microorganisms in the biofilter. The bacteria were identified as the members of the genus Bacillus, Pseudomonas and xanthomonadacea bacterium. The polymerase chain reaction-single stranded conformation polymorphism (PCR-SSCP) method showed that bacterial community profiles changed with the H2S inlet concentration. Our results indicated that the biofilter system, containing peat as the packing material, was proved able to remove H2S from the WWTP odourous pollutants. PMID:23961233

Partitioning of heavy metals in sub-surface flow treatment wetlands receiving high-strength wastewater.

PubMed

Wojciechowska, Ewa; Gajewska, Magdalena

2013-01-01

The retention of heavy metals at two pilot-scale treatment wetlands (TWs), consisting of two vertical flow beds (VSSF) followed by a horizontal flow bed (HSSF) was studied. The TWs received high-strength wastewater: reject waters from sewage sludge centrifugation (RW) and landfill leachate (LL). The concentrations of the metals Fe, Mn, Zn, Al, Pb, Cu, Cd, Co, and Ni were measured in treated wastewater, substrate of the beds and in plant material harvested from the beds (separately in above ground (ABG) parts and below ground (BG) parts). The TWs differed in metals retention. In the RW treating TW the metal removal efficiencies varied from 27% for Pb to over 97% for Fe and Al. In the LL treating system the concentrations of most metals decreased after VSSF-1 and VSSF-2 beds; however, in the outflow from the last (HSSF) bed, the concentrations of metals (apart from Al) increased again, probably due to the anaerobic conditions at the bed. A major removal pathway was sedimentation and adsorption onto soil substrate as well as precipitation and co-precipitation. In the LL treating facility the plants contained substantially higher metal concentrations in BG parts, while the upward movement of metals was restricted. In the RW treating facility the BG/ABG ratios were lower, indicating that metals were transported to shoots.

Comparative Study of Three Regimens of Bowel Preparation Before Transabdominal Ultrasonography of the Colon.

PubMed

Fan, Xiu-Ping; Zhu, Qiang; Zhou, Ya-Jing; Ma, Teng; Xia, Chun-Xia; Huang, Hui-Lian

2016-09-01

The objective of the study was to compare the efficacy of three bowel preparation regimens for transabdominal colon ultrasonography. A total of 192 consecutive patients were given one of three regimens (senna, magnesium sulfate or polyethylene glycol electrolyte powder) before ultrasonographic examinations. The cleaning grade (I = emptying; II = filled or filled + empty; III = I or II with some retention; and IV = retention [grades I and II were termed "qualified"]) and cleaning range (A = all seven colon sections were qualified; B = four to six sections were qualified; C = three or less sections were qualified) were evaluated retrospectively. Senna was found more effective than polyethylene glycol in terms of cleaning grade (p < 0.001), qualified rate (p < 0.001) and cleaning range (p = 0.003). Senna was better than magnesium sulfate in cleaning grade (p < 0.001). Our results suggest that senna seems to be the preferred regimen for bowel preparation before transabdominal colonic ultrasonography. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Skin penetration and retention of L-ascorbic acid 2-phosphate using multilamellar vesicles.

PubMed

Yoo, Juno; Shanmugam, Srinivasan; Song, Chung-Kil; Kim, Dae-Duk; Choi, Han-Gon; Yong, Chul-Soon; Woo, Jong-Soo; Yoo, Bong Kyu

2008-12-01

Transdermal formulation of L-ascorbic acid 2-phosphate magnesium salt (A2P) was prepared using multilamellar vesicles (MLV). A2P was either physically mixed with or entrapped into three different MLVs of neutral, cationic, and anionic liposome vesicles. For the preparation of neutral MLVs, phosphatidylcholine (PC) and cholesterol (CH) were used. For cationic and anionic MLVs, dioleoyl-trimethylammonium-propane and dimyristoyl glycerophosphate were added as surface charge inducers, respectively, in addition to PC and CH. Particle size of the three A2P-loaded MLVs was submicron, and polydispersity index revealed homogenous distribution of the prepared MLVs except neutral ones. Skin penetration study with hairless mouse skin showed that both physical mixtures of A2P with empty MLVs and A2P-loaded MLVs increased penetration of the drug compared to aqueous A2P solution. During the penetration, however, significant amount of the drug was metabolized into L-ascorbic acid, which has no beneficial effect on stimulation of hair growth. Out of the physical mixtures and A2P-loaded MLVs tested, physical mixture of A2P with empty cationic MLV resulted in the greatest skin penetration and retention in hairless mouse skin.

Hospitals' vertical integration into skilled nursing: a rational approach to controlling transaction costs.

PubMed

Lehrman, S; Shore, K K

1998-01-01

Using 1985 and 1988 American Hospital Association data, this study examines 1,523 hospitals nationwide and concludes that hospitals' ownership of skilled nursing facilities helps minimize the transaction costs associated with post-acute patient transfers while productively using empty hospital beds. Unfortunately, such ownership creates complex cost, quality, and accessibility trade-offs in terms of the skilled nursing care provided.

[Influence on glycemic control of improved diabetic gastroparesis by long-term cisapride therapy].

PubMed

Ishii, K; Tanabe, S; Mitsuhashi, T; Saigenji, K

1995-10-01

To investigate the effect on glycemic control of improving diabetic gastroparesis, we evaluated symptoms (scored), gastric motor functions (solid and liquid gastric emptying studies and electrogastrography), and glycemic control in 11 patients with diabetic gastroparesis (5 men, 6 women, 50.4 +/- 4.5 years old) before and after treatment with cisapride (15 mg/day p.o., 12 weeks). None of the patients had organic abnormalities on gastrointestinal endoscopy. The dysmotility symptom score (maximum: 18) on cisapride significantly improved from 13.1 to 4.0 (p < 0.01). Retention rates at 15 and 80 minutes after ingestion improved in a solid-food gastric emptying study using a test meal of instant noodles labeled with 37 MBq (1 mCi) technetium-99m (both p < 0.05). Liquid gastric emptying, evaluated using a sulfamethizole technique, also improved but not significantly. Electrogastrography revealed no significant changes after treatment, but the postprandial rate of normal frequency waves tended to increase. Glycemic control was assessed based on HbA1C, fructosamine and M value. There were no significant changes in glycemic control after treatment with cisapride. We conclude that long-term administration of cisapride reduced dysmotility symptoms and improved solid and liquid gastric emptying without adversely affecting glycemic control.

Scalable synthesis of NiMoO4 microspheres with numerous empty nanovoids as an advanced anode material for Li-ion batteries

NASA Astrophysics Data System (ADS)

Park, Jin-Sung; Cho, Jung Sang; Kang, Yun Chan

2018-03-01

Closely in line with advances in next-generation energy storage materials, anode materials for lithium-ion batteries (LIBs) with high capacity and long cycle life have been widely explored. As part of the current effort, nickel molybdate (NiMoO4) microspheres with empty nanovoids are synthesized via spray drying process and subsequent one-step calcination in air. Dextrin in the atomized droplet is phase segregated during the spray drying process and calcined in air atmosphere, resulting in numerous empty nanovoids well-distributed within a microsphere. The empty nanovoids alleviate volume expansion during cycling, shorten lithium-ion diffusion length, and facilitate contact between electrode and electrolyte materials. Along with the high discharge capacity of NiMoO4 material, as high as 1240 mA h g-1 for the 2nd cycle at a high current density of 1 A g-1, uniquity of the structure enables longer cycle life and higher quality performances. The discharge capacity corresponding to the 500th cycle is 1020 mA h g-1 and the capacity retention calculated from the 2nd cycle is 82%. In addition, a discharge capacity of 413 mA g-1 is obtained at an extremely high current density of 10 A g-1.

Role of hydraulic retention time and granular medium in microbial removal in tertiary treatment reed beds.

PubMed

García, Joan; Vivar, Joan; Aromir, Maria; Mujeriego, Rafael

2003-06-01

The main objective of this paper is to evaluate the role of hydraulic retention time (HRT) and granular medium in faecal coliform (FC) and somatic coliphage (SC) removal in tertiary reed beds. Experiments were carried out in a pilot plant with four parallel reed beds (horizontal subsurface flow constructed wetlands), each one containing a different type of granular medium. This pilot plant is located in a wastewater treatment plant in Montcada i Reixac, near Barcelona, in northeastern Spain. The microbial inactivation ratios obtained in the different beds are compared as a function of three selected HRTs. Secondary effluent from the wastewater treatment plant was used as the influent of the pilot system. The microbial inactivation ratio ranged between 0.1 and 2.7 log-units for FC and from 0.5 to 1.7 log-units for SC in beds with coarser granular material (5-25mm), while it ranged between 0.7 and 3.4 log-units for FC and from 0.9 to 2.6 log-units for SC in the bed with finer material (2-13mm). HRT and granular medium are both key factors in microbial removal in the tertiary reed beds. The microbial inactivation ratio rises as the HRT increases until it reaches a saturation value (in general at an HRT of 3 days). The value of the microbial inactivation ratio at the saturation level depends on the granular medium contained in the bed. The specific surface area necessary to reach 2-3 log-units of FC and SC is approximately 3m(2)/person-equivalent.

Assessing the Use of Sunken Lanes for Water Retention in a Landscape

NASA Astrophysics Data System (ADS)

Zlatuška, Karel

2012-12-01

Newly-designed structures and landscaping elements are often used for flood protection. This article assesses the use of existing sunken lanes for retaining water in a landscape and the sedimentation of washed-off soil. The article also describes ways how to preserve or, at least minimally disrupt, existing biotopes and landscape segments. Geodetic data from one specific sunken lane in South Moravia in the Czech Republic were transferred to a digital terrain model; 9 models were subsequently generated, each with a different longitudinal sunken lane bed slope. Retention dams consisting of gabions were placed in them. The number of dams, the volume of structures made of steel gabions, and the retention area volume behind the dams were determined for each model specifically. It was determined that the number of dams, as well as their total volume, increased with the average longitudinal slope of the sunken lane bed. It was also discovered that the retention volume remained almost the same, as it only very slightly decreases with an increasing longitudinal slope.

Secure Container For Discarded Hypodermic Needles

NASA Technical Reports Server (NTRS)

Lee, Angelene M.

1992-01-01

Container designed for safe retention of discarded blood-collecting hypodermic needles and similar sharp objects used in life-science experiments aboard spacecraft. Needles inserted through self-closing lid and retained magnetically. They are inserted, sharp end first, through spring-loaded flap. Long needles and needles on syringes cannot turn around in container. Can be emptied, cleaned, and reused. Used on Earth to provide unusually secure containment of sharp objects.

Emission studies from combustion of empty fruit bunch pellets in a fluidized bed combustor

NASA Astrophysics Data System (ADS)

Fazli Othaman, Muhamad; Sabudin, Sulastri; Faizal Mohideen Batcha, Mohd

2017-08-01

Malaysia is producing a very large amount of biomass annually from milling activities of oil palm. This biomass is currently being used efficiently in many ways including as fuel for boilers together with fossil fuels. This paper reports the emission characteristics from biomass combustion in a swirling fluidized bed combustor (SFBC). Pelletized empty fruit bunch (PEFB), one of largest biomass produced from oil palm industries were used as fuel in the present study. Combustion experiments were conducted with several quantitiesof excess air: 20%, 40%, 60% and 80% for a constant fuel feedrate of 30kg/hr. The effect of excess air was investigated for three major emissions gaseous namely CO, CO2 and NOx. Fly ash produced from the combustion was also analysed to find the contents of unburnt carbon and other impurities. From the results, it was found that the emission of CO decreased from 64 ppm to 40 ppm while the amount of CO2 increased slightly with the increasing of excess air from 20% to 80%. The NOx emission also increased from 290 ppm to 350 ppm because of N2 in the EA reacts with O2 due to high combustion temperature. The combustion efficiencies of about 99% obtained in the present study, showing the prospects of using SFBC in commercial scale.

Smooth muscle cell biglycan overexpression results in increased lipoprotein retention on extracellular matrix: implications for the retention of lipoproteins in atherosclerosis.

PubMed

O'Brien, Kevin D; Lewis, Katherine; Fischer, Jens W; Johnson, Pamela; Hwang, Jin-Yong; Knopp, Eleanor A; Kinsella, Michael G; Barrett, P Hugh R; Chait, Alan; Wight, Thomas N

2004-11-01

Lipoprotein retention on extracellular matrix (ECM) may play a central role in atherogenesis, and a specific extracellular matrix proteoglycan, biglycan, has been implicated in lipoprotein retention in human atherosclerosis. To test whether increased cellular biglycan expression results in increased retention of lipoproteins on ECM, rat aortic smooth muscle cells (SMCs) were transduced with a human biglycan cDNA-containing retroviral vector (LBSN) or with an empty retroviral vector (LXSN). To assess the importance of biglycan's glycosaminoglycan side chains in lipoprotein retention, ECM binding studies were also performed using RASMCs transduced with a retroviral vector encoding for a mutant, glycosaminoglycan-deficient biglycan (LBmutSN). Human biglycan mRNA and protein were confirmed in LBSN and LBmutSN RASMCs by Northern and Western blot analyses. HDL3+E binding to SMC ECM was increased significantly (as determined by 95% confidence intervals for binding curves) for LBSN as compared to either LXSN or LBmutSN cells; the increases for LBSN cell ECM were due primarily to an approximately 50% increase in binding sites (increased Bmax) versus LXSN cell ECM and of approximately 25% versus LBmutSN cell ECM. These results are consistent with the hypothesis that biglycan, through its glycosaminoglycan side chains, may mediate lipoprotein retention on atherosclerotic plaque ECM.

Char binder for fluidized beds

DOEpatents

Borio, Richard W.; Accortt, Joseph I.

1981-01-01

An arrangement that utilizes agglomerating coal as a binder to bond coal fines and recycled char into an agglomerate mass that will have suitable retention time when introduced into a fluidized bed 14 for combustion. The simultaneous use of coal for a primary fuel and as a binder effects significant savings in the elimination of non-essential materials and processing steps.

Fixed-bed column performances of azure-II and auramine-O adsorption by Pinus eldarica stalks activated carbon and its composite with zno nanoparticles: Optimization by response surface methodology based on central composite design.

PubMed

Jafari, Maryam; Rahimi, Mahmood Reza; Ghaedi, Mehrorang; Javadian, Hamedreza; Asfaram, Arash

2017-12-01

A continuous adsorption was used for removal of azure II (AZ II) and auramine O (AO) from aqueous solutions using Pinus eldarica stalks activated carbon (PES-AC) from aqueous solutions. The effects of initial dye concentration, flow rate, bed height and contact time on removal percentage of AO and AZ II were evaluated and optimized by central composite design (CCD) at optimum pH = 7.0. ZnO nanoparticles loaded on activated carbon were also used to remove AO and AZ II at pH = 7.0 and other optimum conditions. The breakthrough curves were obtained at different flow rates, initial dye concentrations and bed heights and the experimental data were fitted by Thomas, Adams-Bohart and Yoon-Nelson models. The main parameters of fixed-bed column including its adsorption capacity at breakthrough point (q b ), adsorption capacity at saturation point (q s ), mass transfer zone (MTZ), total removal percentage (R%), and empty bed contact time (EBCT) were calculated. The removal percentages calculated for AZ II and AO II were in the range of 51.6-61.1% and 40.6-61.6%, respectively. Bed adsorption capacity (N 0 ) and critical bed depth (Z 0 ) were obtained by BDST model. Copyright © 2017 Elsevier Inc. All rights reserved.

Facilitating Employee Recruitment and Retention through On-Site Child Day Care.

ERIC Educational Resources Information Center

Lombardo, Kathy A.

An early childhood educator at a 360-bed community general hospital implemented a licensed on-site child care program for children between 6 weeks and 10 years of age in order to improve employee recruitment and retention by assisting employees with appropriate child care arrangements. A parent questionnaire was used to assess the degree to which…

An Experimental Test of Factors Attracting Deer Mice into Buildings.

PubMed

Kuenzi, Amy J; Douglass, Richard

2009-09-01

Deer mice (Peromyscus maniculatus) are the principal reservoir host of Sin Nombre virus (SNV). Deer mice use a wide variety of habitats including peridomestic settings in and around human dwellings, their presence in and around homes has been implicated as a risk factor for acquiring Hantavirus Pulmonary Syndrome. Deer mice are believed to enter buildings in order to gain access to a variety of resources including food, bedding material, and better thermal microclimates. However, no one has experimentally tested which factors influence mice use of buildings. We conducted experiments using small simulated buildings to determine the effects of two factors, i.e., food and bedding material, on mouse activity in these buildings. We also examined if these effects varied with time of year. We found that deer mice entered our buildings regardless of the presence or absence of food or bedding. However, the amount of activity in buildings was affected by what they contained. We found significantly higher indices of activity in buildings containing food compared to both empty buildings (control) and buildings containing bedding material. Time of year did not affect activity in buildings.

A phenomenological retention tank model using settling velocity distributions.

PubMed

Maruejouls, T; Vanrolleghem, P A; Pelletier, G; Lessard, P

2012-12-15

Many authors have observed the influence of the settling velocity distribution on the sedimentation process in retention tanks. However, the pollutants' behaviour in such tanks is not well characterized, especially with respect to their settling velocity distribution. This paper presents a phenomenological modelling study dealing with the way by which the settling velocity distribution of particles in combined sewage changes between entering and leaving an off-line retention tank. The work starts from a previously published model (Lessard and Beck, 1991) which is first implemented in a wastewater management modelling software, to be then tested with full-scale field data for the first time. Next, its performance is improved by integrating the particle settling velocity distribution and adding a description of the resuspension due to pumping for emptying the tank. Finally, the potential of the improved model is demonstrated by comparing the results for one more rain event. Copyright © 2011 Elsevier Ltd. All rights reserved.

Removal characteristics and kinetic analysis of an aerobic vapor-phase bioreactor for hydrophobic alpha-pinene.

PubMed

Jiang, Yifeng; Li, Shanshan; Cheng, Zhuowei; Zhu, Runye; Chen, Jianmeng

2012-01-01

Biofiltration is considered an effective method to control volatile organic compounds (VOCs) pollution. This study was conducted to evaluate the potential use of a bacterial biofilter packed with wood chips and peat for the removal of hydrophobic alpha-pinene. When inoculated with two pure degraders and adapted activated sludge, a removal efficiency (RE) of more than 95% was achieved after a startup period of 11 days. The maximum elimination capacity (EC) of 50 g/(m3 x hr) with RE of 94% was obtained at empty bed retention time (EBRT) of 102 sec. When higher alpha-pinene concentrations and shorter EBRTs were applied, the REs and ECs decreased significantly due to mass-transfer and biological reaction limitations. As deduced from the experimental results, approximately 74% of alpha-pinene were completely mineralized by the consortiums and the biomass yield was 0.60 g biomass/g alpha-pinene. Sequence analysis of the selected bands excised from denaturing gradient gel electrophoresis revealed that the inoculated pure cultures could be present during the whole operation, and others were closely related to bacteria being able to degrade hydrocarbons. The kinetic results demonstrated that the whole biofiltration for alpha-pinene was diffusion-limit controlled owing to its hydrophobic characteristics. These findings indicated that this bacterial biofiltration is a promising technology for the remediation of hydrophobic industrial waste gases containing alpha-pinene.

Sequential biofiltration - A novel approach for enhanced biological removal of trace organic chemicals from wastewater treatment plant effluent.

PubMed

Müller, Johann; Drewes, Jörg E; Hübner, Uwe

2017-12-15

Recent studies revealed the benefits of oligotrophic and oxic conditions for the biological removal of many trace organic chemicals (TOrCs) during soil-aquifer treatment. These findings indicate an unused tuning potential that might also be applicable in engineered biofiltration systems with drastically reduced hydraulic retention times for an enhanced mitigation of TOrCs during wastewater treatment. This study introduces the novel approach of sequential biofiltration (SBF) for the advanced treatment of secondary effluent using two granular media filters operated in series with an intermediate aeration step aiming for oxic and oligotrophic conditions in the second filter stage. Results from the experiments conducted at pilot-scale confirm a reduced substrate availability and predominantly oxic conditions in the second filter stage of the SBF setup. An increased removal of several TOrCs was observed in an SBF system as compared to a conventional single-stage biofiltration unit operated at the same overall empty bed contact time (EBCT). Short-term tests with varying EBCTs in the first filter stage revealed a high degree of system robustness of TOrC mitigation when confronted with sudden hydraulic load variations. Higher removal of several TOrCs at increased EBCTs in the second filter stage indicates that EBCT might play a crucial role for the degradation of certain compounds. Copyright © 2017 Elsevier Ltd. All rights reserved.

The hydrological behaviour of extensive and intensive green roofs in a dry climate.

PubMed

Razzaghmanesh, M; Beecham, S

2014-11-15

This paper presents the results of a hydrological investigation of four medium scale green roofs that were set up at the University of South Australia. In this study, the potential of green roofs as a source control device was investigated over a 2 year period using four medium size green roof beds comprised of two growth media types and two media depths. During the term of this study, 226 rainfall events were recorded and these were representative of the Adelaide climate. In general, there were no statistically significant differences between the rainfall and runoff parameters for the intensive and extensive beds except for peak attenuation and peak runoff delay, for which higher values were recorded in the intensive beds. Longer dry periods generally resulted in higher retention coefficients and higher retention was also recorded in warmer seasons. The average retention coefficient for intensive systems (89%) was higher than for extensive systems (74%). It was shown that rainfall depth, intensity, duration and also average dry weather period between events can change the retention performance and runoff volume of the green roofs. Comparison of green and simulated conventional roofs indicated that the former were able to mitigate the peak of runoff and could delay the start of runoff. These characteristics are important for most source control measures. The recorded rainfall and runoff data displayed a non-linear relationship. Also, the results indicated that continuous time series modelling would be a more appropriate technique than using peak rainfall intensity methods for green roof design and simulation. Copyright © 2014 Elsevier B.V. All rights reserved.

Amino acid utilization and body composition of growing pigs fed processed soybean meal or rapeseed meal with or without amino acid supplementation.

PubMed

Hulshof, T G; van der Poel, A F B; Hendriks, W H; Bikker, P

2017-07-01

Feed ingredients used in swine diets are often processed to improve nutritional value. However, (over-)processing may result in chemical reactions with amino acids (AAs) that decrease their ileal digestibility. This study aimed to determine effects of (over-)processing of soybean meal (SBM) and rapeseed meal (RSM) on post-absorptive utilization of ileal digestible AAs for retention and on body AA composition of growing pigs. Soybean meal and RSM were processed by secondary toasting in the presence of lignosulfonate to obtain processed soybean meal (pSBM) and processed rapeseed meal (pRSM). Four diets contained SBM, pSBM, RSM or pRSM as sole protein source. Two additional diets contained pSBM or pRSM and were supplemented with crystalline AA to similar standardized ileal digestible (SID) AA level as the SBM or RSM diet. These diets were used to verify that processing affected AA retention by affecting ileal AA digestibility rather than post-absorptive AA utilization. The SID AA levels of the protein sources were determined in a previous study. In total, 59 pigs were used (initial BW of 15.6±0.7 kg) of which five were used to determine initial body composition at the start of the experiment. In total, 54 pigs were fed one of six experimental diets and were slaughtered at a BW of 40 kg. The organ fraction (i.e. empty organs plus blood) and carcass were analyzed separately for N and AA content. Post-absorptive AA utilization was calculated from AA retention and SID AA intake. An interaction between diet type, comprising effects of processing and supplementing crystalline AA, and protein source was observed for CP content in the organ fraction, carcass and empty body and for nutrient retention. Processing reduced CP content and nutrient retention more for SBM than for RSM. Moreover, processing reduced (P<0.001) the lysine content in the organ fraction for both protein sources. Supplementing crystalline AA ameliorated the effect of processing on these variables. Thus, the data indicated that processing affected retention by reducing digestibility. Correcting AA retention for SID AA intake was, therefore, expected to result in similar post-absorptive AA utilization which was observed for the RSM diets. However, post-absorptive AA utilization was lower for the pSBM diet than for the SBM diet which might be related to an imbalanced post-absorptive AA supply. In conclusion, processing negatively affected nutrient retention for both protein sources and post-absorptive utilization of SID AA for retention for SBM. Effects of processing were compensated by supplementing crystalline AA.

Fluidized bed combustor modeling

NASA Technical Reports Server (NTRS)

Horio, M.; Rengarajan, P.; Krishnan, R.; Wen, C. Y.

1977-01-01

A general mathematical model for the prediction of performance of a fluidized bed coal combustor (FBC) is developed. The basic elements of the model consist of: (1) hydrodynamics of gas and solids in the combustor; (2) description of gas and solids contacting pattern; (3) kinetics of combustion; and (4) absorption of SO2 by limestone in the bed. The model is capable of calculating the combustion efficiency, axial bed temperature profile, carbon hold-up in the bed, oxygen and SO2 concentrations in the bubble and emulsion phases, sulfur retention efficiency and particulate carry over by elutriation. The effects of bed geometry, excess air, location of heat transfer coils in the bed, calcium to sulfur ratio in the feeds, etc. are examined. The calculated results are compared with experimental data. Agreement between the calculated results and the observed data are satisfactory in most cases. Recommendations to enhance the accuracy of prediction of the model are suggested.

Coaxial EMI Sensor for UXO Detection and Discrimination

DTIC Science & Technology

2008-05-01

Raleigh, North Carolina. Geophex has a 10 m x 10 m test bed in which 21 metal pipes of various sizes, some ferrous (steel) and some nonferrous (3...spectral matching was expected to lower the FAR, but with the wide range of anticipated UXO in terms of size and metal content, the corresponding wide...warrant further investigation.” Grid squares with a response stage below the stated noise threshold are declared empty (neither UXO nor metallic

Actinidin from kiwifruit (Actinidia deliciosa cv. Hayward) increases the digestion and rate of gastric emptying of meat proteins in the growing pig.

PubMed

Montoya, Carlos A; Rutherfurd, Shane M; Olson, Trent D; Purba, Ajitpal S; Drummond, Lynley N; Boland, Mike J; Moughan, Paul J

2014-03-28

The present study aimed to investigate the effect of dietary actinidin on the kinetics of gastric digestion of beef muscle proteins and on the rate of stomach emptying in growing pigs. For this purpose, 120 pigs (mean body weight 28 (sd 2·9) kg) were fed beef muscle protein-based diets containing either actinidin (fresh green kiwifruit pulp or gold kiwifruit pulp supplemented with purified actinidin) or no actinidin (fresh gold kiwifruit pulp or green kiwifruit pulp with inactivated actinidin). Additionally, fifteen pigs were fed with a protein-free diet to determine the endogenous protein flow. Pigs were euthanised at exactly 0·5, 1, 3, 5 and 7 h postprandially (n 6 per time point for each kiwifruit diet and n 3 for protein-free diet). Stomach chyme was collected for measuring gastric retention, actinidin activity, individual beef muscle protein digestion based on SDS-PAGE and the degree of hydrolysis based on the appearance of free amino groups. The stomach emptying of DM and N was faster when actinidin was present in the diet (P< 0·05): the half gastric emptying time of DM was 137 v. 172 min ( ± 7·4 min pooled standard error) for the diets with and without actinidin, respectively. The presence of dietary actinidin in the stomach chyme increased the digestion of beef muscle protein (P< 0·05) and, more specifically, those proteins with a high molecular weight (>34 kDa; P< 0·05). In conclusion, dietary actinidin fed in the form of fresh green kiwifruit increased the rate of gastric emptying and the digestion of several beef muscle proteins.

The Baptist Health Nurse Retention Questionnaire: A Methodological Study, Part 1.

PubMed

Lengerich, Alexander; Bugajski, Andrew; Marchese, Matthew; Hall, Brittany; Yackzan, Susan; Davies, Claire; Brockopp, Dorothy

2017-05-01

The purposes of this study were to develop and test the Baptist Health Nurse Retention Questionnaire (BHNRQ) and examine the importance of nurse retention factors. Multiple factors, including increasing patient acuity levels, have led to concerns regarding nurse retention. An understanding of current factors related to retention is limited. To establish the psychometric properties of the BHNRQ, data were collected from 279 bedside nurses at a 391-bed, Magnet® redesignated community hospital. A principal component analysis was conducted to determine the subscale structure of the BHNRQ. Additional analyses were conducted related to content validity and test-retest reliability. The results of the principal components analysis revealed 3 subscales: nursing practice, management, and staffing. Analyses demonstrate that the BHNRQ is a reliable and valid instrument for measuring nurse retention factors. The BHNRQ was found to be a clinically useful instrument for measuring important factors related to nurse retention.

Comparison of PPCPs removal on a parallel-operated MBR and AS system and evaluation of effluent post-treatment on vertical flow reed beds.

PubMed

Reif, R; Besancon, A; Le Corre, K; Jefferson, B; Lema, J M; Omil, F

2011-01-01

The presence in the aquatic environment of xenobiotics such as Pharmaceutical and Personal Care Products (PPCPs) has emerged as an issue of concern. Upgrading sewage treatment quality with modern technologies such as Membrane Bioreactors (MBRs) and/or implementing a further posttreatment might mitigate the release of xenobiotics into surface waters. The performance of two processes treating municipal sewage, a MBR and an Activated Sludge (AS) unit, have been compared in terms of PPCPs removal. Moreover, their effluents were treated using vertical flow reed beds. Both systems were operated under similar conditions, more specifically Hydraulic Retention Time (HRT), maintained at 8 hours, and Sludge Retention Time (SRT) set at 6 and 20 days. Pharmaceuticals belong to therapeutic groups such as antiepileptics (carbamazepine) and analgesics (ibuprofen, naproxen, diclofenac), whereas the personal care products are musk fragrances (galaxolide and tonalide). Xenobiotics removals achieved in the MBR showed better results, particularly for the acidic drugs ibuprofen (87% vs. 50%) and naproxen (56% vs. 6%) operating at low SRT. After filtration through vertical flow reed-beds, PPCPs content in effluents was decreased, below 1 ppb in most cases, improving the effluent quality and confirming reed-beds as an interesting low cost alternative in order to attenuate xenobiotics contamination.

The ghrelin agonist RM-131 accelerates gastric emptying of solids and reduces symptoms in patients with type 1 diabetes mellitus.

PubMed

Shin, Andrea; Camilleri, Michael; Busciglio, Irene; Burton, Duane; Smith, Steven A; Vella, Adrian; Ryks, Michael; Rhoten, Deborah; Zinsmeister, Alan R

2013-11-01

RM-131, a synthetic ghrelin agonist, greatly accelerates gastric emptying of solids in patients with type 2 diabetes and delayed gastric emptying (DGE). We investigated the safety and effects of a single dose of RM-131 on gastric emptying and upper gastrointestinal (GI) symptoms in patients with type 1 diabetes and previously documented DGE. In a double-blind cross-over study, 10 patients with type 1 diabetes (age, 45.7 ± 4.4 y; body mass index, 24.1 ± 1.1 kg/m(2)) and previously documented DGE were assigned in random order to receive a single dose of RM-131 (100 μg, subcutaneously) or placebo. Thirty minutes later, they ate a radiolabeled solid-liquid meal containing EggBeaters (ConAgra Foods, Omaha, NE), and then underwent 4 hours of gastric emptying and 6 hours of colonic filling analyses by scintigraphy. Upper GI symptoms were assessed using a daily diary, gastroparesis cardinal symptom index (total GCSI-DD) and a combination of nausea, vomiting, fullness, and pain (NVFP) scores (each rated on a 0-5 scale). At screening, participants' mean level of hemoglobin A1c was 9.1% ± 0.5%; their total GCSI-DD score was 1.66 ± 0.38 (median, 1.71), and their total NVFP score was 1.73 ± 0.39 (median, 1.9). The t1/2 of solid gastric emptying was 84.9 ± 31.6 minutes when subjects were given RM-131 and 118.7 ± 26.7 when they were given a placebo. The median difference (Δ)was 33.9 minutes (interquartile range [IQR] -12, -49), or -54.7% (IQR, -21%,-110%). RM-131 decreased gastric retention of solids at 1 hour (P = .005) and 2 hours (P = .019). Numeric differences in t1/2 for gastric emptying of liquids, solid gastric emptying lag time, and colonic filling at 6 hours were not significant. Total GCSI-DD scores were 0.79 on placebo (IQR, 0.75, 2.08) and 0.17 on RM-131 (IQR, 0.00, 0.67; P = .026); NVFP scores were lower on RM-131 (P = .041). There were no significant adverse effects. RM-131 significantly accelerates gastric emptying of solids and reduces upper GI symptoms in patients with type 1 diabetes and documented DGE. Copyright © 2013 AGA Institute. Published by Elsevier Inc. All rights reserved.

Installation Restoration Program. Phase 1. Records Search Andrews AFB. Maryland

DTIC Science & Technology

1985-06-01

red to silvery-qrey, functions ma a conf ining bed. Formation. ~Va plastics thin lonses of pole gray silt. Ann"a Formation. ye (0-210 sand, qrsenieh...the Nanjemoy Formation (a clayey glauconi- tic sand, two to thirty feet thick) and the Marlboro Clay (a plastic clay with silt partings, two to... plastics , empty 55-gallon drums, waste lumber, tires, pipes, and hospital wastes such as unused needles and chemical reagents. In the past, Site D-4 was

[External sphincterotomy using bipolar vaporisation in saline. First results].

PubMed

Even, L; Guillotreau, J; Mingat, N; Castel-Lacanal, E; Braley, E; Malavaud, B; Marque, P; Rischmann, P; Gamé, X

2012-07-01

The aim of this study was to assess the feasibility, efficacy and tolerance of external urethral sphincter vaporization in saline for treating detrusor-sphincter dyssynergia. Between 2009 and 2011 a monocentric prospective study of ten men mean age 58±9 years with neurogenic detrusor-sphincter dyssynergia was carried out. Preoperative evaluation included kidney ultrasound scan, 24-hour creatinine clearance, urodynamics, retrograde and voiding urethrocystography and an at least 6 months temporary stent sphincterotomy. Postoperative assessment was composed of an ultrasound scan post-void residual volume measurement when the urethral catheter were removed and 1 year after the procedure, a retrograde and voiding urethrocystography at 3 months and a flexible cystoscopy at 1 year. At the catheter removal, eight patients emptied their bladder at completion, a supra-pubic catheter was temporary left in one case and a patient had a permanent urinary retention. For a mean follow-up of 22±11 months, eight patients emptied their bladder at completion and two had a complete urinary retention related to a detrusor underactivity. An orchitis occurred in one case 1 month after the procedure and an urethral stricture in four cases in 12.75±5.68 months on average. External urethral sphincter vaporisation saline was feasible and efficient for treating detrusor-sphincter dyssynergia but was associated with a high risk of urethral stricture. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Long-term micturition problems of asymptomatic postpartum urinary retention: a prospective case-control study.

PubMed

Mulder, Femke E M; Hakvoort, Robert A; de Bruin, Jan-Peter; Janszen, Erica W; van der Post, Joris A M; Roovers, Jan-Paul W R

2018-04-01

Covert (asymptomatic) postpartum urinary retention (PUR) is defined as post-void residual volume (PVRV) ≥150 mL. Although often supposed to be a common and harmless phenomenon, no data are available on the potential long-term micturition problems of increased PVRV after vaginal delivery. After the first spontaneous void post-vaginal delivery, PVRV was measured using a portable scanning device. Micturition symptoms were compared using validated questionnaires between women with PVRV < 150 mL and those with PVRV ≥150 mL until 1 year after delivery. Women with PVRV ≥ 150 mL were followed until complete bladder emptying was achieved. Data of 105 patients with PVRV < 150 mL and 119 with PVRV ≥ 150 mL were available for analysis. 75% of all patients included had PVRV ≥ 250 mL. More primiparous patients had PVRV ≥ 150 mL (p < 0.02). 92% of women with PVRV ≥ 150 mL after delivery were able to adequately empty their bladder within 4 days. One year after delivery, no statistically significant differences were found. Covert PUR according to the definition of PVRV ≥ 150 mL, is a common and transient phenomenon that does not result in more lower urinary tract symptoms 1 year after delivery. Although the current definition is not useful in identifying postpartum women with a pathological condition, we suggest that the definition of covert PUR should be change to: "PVRV≥500 mL after the first spontaneous void after (vaginal) delivery." This cut-off value is the value at which some women do need more time to normalise emptying of the bladder. The exact clinical implications of covert PUR need to be further studied in this subcategory of women.

A modified biotrickling filter for nitrification-denitrification in the treatment of an ammonia-contaminated air stream.

PubMed

Raboni, Massimo; Torretta, Vincenzo

2016-12-01

A conventional biotrickling filter for airborne ammonia nitrification has been modified, by converting the liquid sump into a biological denitrifying reactor. The biotrickling filter achieves an average ammonia removal efficiency of 92.4 %, with an empty bed retention time (EBRT) equal to 36 s and an average ammonia concentration of 54.7 mg Nm -3 in the raw air stream. The denitrification reactor converts ammonia into inert gas N 2 , in addition to other important advantages connected to the alkaline character of the biochemical pathway of the denitrifying bacteria. Firstly, the trickling water crossing the denitrification reactor underwent a notable pH increase from 7.3 to 8.0 which prevented the acidic inhibition of the nitrifying bacteria due to the buildup of nitric and nitrous acids. Secondly, the pH increase created the ideal conditions for the autotrophic nitrifying bacteria. The tests proved that an ammonia removal efficiency of above 90 % can be achieved with an EBRT greater than 30 s and a volumetric load lower than 200 g NH 3  m -3  day -1 . The results of the biofilm observation by using a scanning confocal laser microscope are reported together with the identification of degrading bacteria genera in the biotrickling filter. The efficiency of the plant and its excellent operational stability highlight the effectiveness of the synergistic action between the denitrification reactor and the biotrickling filter in removing airborne ammonia.

Removal of dichloromethane from waste gas streams using a hybrid bubble column/biofilter bioreactor

PubMed Central

2014-01-01

The performance of a hybrid bubble column/biofilter (HBCB) bioreactor for the removal of dichloromethane (DCM) from waste gas streams was studied in continuous mode for several months. The HBCB bioreactor consisted of two compartments: bubble column bioreactor removing DCM from liquid phase and biofilter removing DCM from gas phase. Effect of inlet DCM concentration on the elimination capacity was examined in the DCM concentration range of 34–359 ppm with loading rates ranged from 2.2 to 22.8 g/m3.h and constant total empty bed retention time (EBRT) of 200 s. In the equal loading rates, the elimination capacity and removal efficiency of the biofilter were higher than the corresponding values of the bubble column bioreactor. The maximum elimination capacity of the HBCB bioreactor was determined to be 15.7 g/m3.h occurred in the highest loading rate of 22.8 g/m3.h with removal efficiency of 69%. The overall mineralization portion of the HBCB bioreactor was in the range of 72-79%. The mixed liquor acidic pH especially below 5.5 inhibited microbial activity and decreased the elimination capacity. Inhibitory effect of high ionic strength was initiated in the mixed liquor electrical conductivity of 12.2 mS/cm. This study indicated that the HBCB bioreactor could benefit from advantages of both bubble column and biofilter reactors and could remove DCM from waste gas streams in a better manner. PMID:24406056

A demonstration of biofiltration for VOC removal in petrochemical industries.

PubMed

Zhao, Lan; Huang, Shaobin; Wei, Zongmin

2014-05-01

A biotrickling filter demo has been set up in a petrochemical factory in Sinopec Group for about 10 months with a maximum inlet gas flow rate of 3000 m3 h(-1). The purpose of this project is to assess the ability of the biotrickling filter to remove hardly biodegradable VOCs such as benzene, toluene and xylene which are recalcitrant and poorly water soluble and commonly found in petrochemical factories. Light-weight hollow ceramic balls (Φ 5-8 cm) were used as the packing media treated with large amounts of circulating water (2.4 m3 m(-2) h(-1)) added with bacterial species. The controlled empty bed retention time (EBRT) of 240 s is a key parameter for reaching a removal efficiency of 95% for benzene, toluene, xylene, and 90% for total hydrocarbons. The demo has been successfully adopted and practically applied in waste air treatments in many petrochemical industries for about two years. The net inlet concentrations of benzene, toluene and xylene were varied from 0.5 to 3 g m(-3). The biofiltration process is highly efficient for the removal of hydrophobic and recalcitrant VOCs with various concentrations from the petrochemical factories. The SEM analysis of the bacterial community in the BTF during VOC removal showed that Pseudomonas putida and Klebsiella sp. phylum were dominant and shutdown periods could play a role in forming the community structural differences and leading to the changes of removal efficiencies.

Biofiltration of gasoline and ethanol-amended gasoline vapors.

PubMed

Soares, Marlene; Woiciechowski, Adenise L; Kozliak, Evguenii I; Paca, Jan; Soccol, Carlos R

2012-01-01

Assuming the projected increase in use of ethanol as a biofuel, the current study was conducted to compare the biofiltration efficiencies for plain and 25% ethanol-containing gasoline. Two biofilters were operated in a downflow mode for 7 months, one of them being compost-based whereas the other using a synthetic packing material, granulated tire rubber, inoculated with gasoline-degrading microorganisms. Inlet concentrations measured as total hydrocarbon (TH) ranged from 1.9 to 5.8 g m(-3) at a constant empty bed retention time of 6.84 min. Contrary to the expectations based on microbiological considerations, ethanol-amended gasoline was more readily biodegraded than plain hydrocarbons, with the respective steady state elimination capacities of 26-43 and 14-18 gTH m(-3) h(-1) for the compost biofilter. The efficiency of both biofilters significantly declined upon the application of higher loads of plain gasoline, yet immediately recovering when switched back to ethanol-blended gasoline. The unexpected effect of ethanol in promoting gasoline biodegradation was explained by increasing hydrocarbon partitioning into the aqueous phase, with mass transfer being rate limiting for the bulk of components. The tire rubber biofilter, after a long acclimation, surpassed the compost biofilter in performance, presumably due to the 'buffering' effect of this packing material increasing the accessibility of gasoline hydrocarbons to the biofilm. With improved substrate mass transfer, biodegradable hydrocarbons were removed in the tire rubber biofilter's first reactor stage, with most of the remaining poorly degradable smaller-size hydrocarbons being degraded in the second stage.

Assessment of the bacteriological activity associated with granular activated carbon treatment of drinking water.

PubMed Central

Stewart, M H; Wolfe, R L; Means, E G

1990-01-01

Bacteriological analyses were performed on the effluent from a conventional water treatment pilot plant in which granular activated carbon (GAC) had been used as the final process to assess the impact of GAC on the microbial quality of the water produced. Samples were collected twice weekly for 160 days from the effluents of six GAC columns, each of which used one of four different empty-bed contact times (7.5, 15, 30, and 60 min). The samples were analyzed for heterotrophic plate counts and total coliforms. Effluent samples were also exposed to chloramines and free chlorine for 60 min (pH 8.2, 23 degrees C). Bacterial identifications were performed on the disinfected and nondisinfected effluents. Additional studies were conducted to assess the bacteriological activity associated with released GAC particles. The results indicated that heterotrophic plate counts in the effluents from all columns increased to 10(5) CFU/ml within 5 days and subsequently stabilized at 10(4) CFU/ml. The heterotrophic plate counts did not differ at different empty-bed contact times. Coliforms (identified as Enterobacter spp.) were recovered from the nondisinfected effluent on only two occasions. The disinfection results indicated that 1.5 mg of chloramines per liter inactivated approximately 50% more bacteria than did 1.0 mg of free chlorine per liter after 1 h of contact time. Chloramines and chlorine selected for the development of different bacterial species--Pseudomonas spp. and Flavobacterium spp., respectively.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2082828

Removal of persistent organic pollutants from micro-polluted drinking water by triolein embedded absorbent.

PubMed

Liu, Huijuan; Ru, Jia; Qu, Jiuhui; Dai, Ruihua; Wang, Zijian; Hu, Chun

2009-06-01

A new biomimetic absorbent, cellulose acetate (CA) embedded with triolein (CA-triolein), was prepared and applied for the removal of persistent organic pollutants (POPs) from micro-polluted aqueous solution. The comparison of CA-triolein, CA and granular activated carbon (GAC) for dieldrin removal was investigated. Results showed that CA-triolein absorbent gave a lowest residual concentration after 24 h although GAC had high removal rate in the first 4 h adsorption. Then the removal efficiency of mixed POPs (e.g. aldrin, dieldrin, endrin and heptachlor epoxide), absorption isotherm, absorbent regeneration and initial column experiments of CA-triolein were studied in detail. The linear absorption isotherm and the independent absorption in binary isotherm indicated that the selected POPs are mainly absorbed onto CA-triolein absorbent by a partition mechanism. The absorption constant, K, was closely related to the hydrophobic property of the compound. Thermodynamic calculations showed that the absorption was spontaneous, with a high affinity and the absorption was an endothermic reaction. Rinsing with hexane the CA-triolein absorbent can be regenerated after absorption of POPs. No significant decrease in the dieldrin removal efficiency was observed even when the absorption-regeneration process was repeated for five times. The results of initial column experiments showed that the CA-triolein absorbent did not reach the breakthrough point at a breakthrough empty-bed volume (BV) of 3200 when the influent concentration was 1-1.5 microg/L and the empty-bed contact time (EBCT) was 20 min.

Behavioral and Psychological Issues in Long Duration Head-down Bed Rest

NASA Technical Reports Server (NTRS)

Seaton, Kimberly A.; Bowie, Kendra; Sipes, Walter A.

2008-01-01

Behavioral health services, similar to those offered to the U.S. astronauts who complete six-month missions on board the International Space Station, were provided to 13 long-duration head-down bed rest participants. Issues in psychological screening, selection, and support are discussed as they relate to other isolated and confined environments. Psychological services offered to participants are described, and challenges in subject selection and retention are discussed. Psychological support and training provided to both subjects and study personnel have successfully improved the well-being of study participants. Behavioral health services are indispensable to long-duration head-down tilt bed rest studies.

Three-dimensional reconstruction of the angioarchitecture of the ciliary body of the West Indian manatee (Trichechus manatus).

PubMed

Natiello, Michelle; Samuelson, Don

2005-01-01

To examine the angioarchitecture of the ciliary body in the West Indian manatee (Trichechus manatus), through the use of three-dimensional reconstruction. Specimens from West Indian manatee were preserved in 10% buffered formalin, embedded in paraffin, serial sectioned and stained by Masson trichrome for light microscopic three-dimensional reconstruction and evaluation. The network of blood vessels in the ciliary processes of the West Indian manatee is fed by the major arterial circle that lies mostly near the base of the iris. The branching arterioles give rise to a capillary-sinusoidal bed that extends internally along each process, emptying into two sets of veins, one being elevated. The elevated and nonelevated veins join posteriorly before emptying into the choroidal venous system. The angioarchitecture of the ciliary body of the West Indian manatee is clearly unique when compared to those previously examined in land mammals. Three-dimensional reconstruction of paraffin sections is an effective means to evaluate vascular patterns in ocular specimens, especially those unavailable for corrosion casting.

Biological treatment of toxic petroleum spent caustic in fluidized bed bioreactor using immobilized cells of Thiobacillus RAI01.

PubMed

Potumarthi, Ravichandra; Mugeraya, Gopal; Jetty, Annapurna

2008-12-01

In the present studies, newly isolated Thiobacillus sp was used for the treatment of synthetic spent sulfide caustic in a laboratory-scale fluidized bed bioreactor. The sulfide oxidation was tested using Ca-alginate immobilized Thiobacillus sp. Initially, response surface methodology was applied for the optimization of four parameters to check the sulfide oxidation efficiency in batch mode. Further, reactor was operated in continuous mode for 51 days at different sulfide loading rates and retention times to test the sulfide oxidation and sulfate and thiosulfate formation. Sulfide conversions in the range of 90-98% were obtained at almost all sulfide loading rates and hydraulic retention times. However, increased loading rates resulted in lower sulfide oxidation capacity. All the experiments were conducted at constant pH of around 6 and temperature of 30 +/- 5 degrees C.

Altiplano of the Central Andes as seen from STS-66 shuttle Atlantis

NASA Image and Video Library

1994-11-14

This photograph captures the exotic volcanic terrain of the Altiplano of the Central Andes. Some of the remarkable details include the west-pointing wind streaks, resulting from fine dust being transported across the Andes by high winds; paleto (old) shorelines along the margins of the salars (or dry lake beds), recording the changes in water levels on the high Altiplano; beautiful alluvial fans emptying onto some of the salars; and the hundreds of volcanic land forms which can be mapped and interpreted to help decipher the volcanic history of the region.

A model stomach system to investigate disintegration kinetics of solid foods during gastric digestion.

PubMed

Kong, F; Singh, R P

2008-06-01

Knowledge of the disintegration kinetics of food particulates in the human stomach is essential for assessing the bioaccessibility of nutrients in solid foods and understanding stomach emptying. The objective of this study was to develop a model stomach system and to investigate the kinetics of food disintegration. Our system consisted mainly of a turntable and a jacketed glass chamber containing simulated gastric juice in which plastic beads were added to simulate food particulates as well as provide a suitable mechanical destructive force on food samples. The mechanical force on the samples was simultaneously measured using the load cell of a TA-XT2 texture analyzer. Cylindrical carrots and ham samples were used as representative foods. The system is capable of simulating the in vivo stomach in terms of providing a wide range of continuous and periodic forces comparable to those measured in vivo. The modified power exponential function of the form y(t)= 1 - (1 -e(-kt))(beta), where y(t) is the mass retention ratio at time t, provided a reasonable description for the disintegration performance of tested foods. The mass retention curve can be either a sigmoidal decay with an initial delay or an exponential decay, which are decided largely by the hardness of the foods during digestion and the extent of physical force acting on the foods. A good match was observed between the kinetics of food disintegration and in vivo stomach emptying.

The Importance of Factors Related to Nurse Retention: Using the Baptist Health Nurse Retention Questionnaire, Part 2.

PubMed

Bugajski, Andrew; Lengerich, Alex; Marchese, Matthew; Hall, Brittany; Yackzan, Susan; Davies, Claire; Brockopp, Dorothy

2017-06-01

The purpose of this study was to examine the importance of factors related to nurse retention. Retaining nurses within the healthcare system is a challenge for hospital administrators. Understanding factors important to nurse retention is essential. Responses of nurses (n = 279) to the Baptist Health Nurse Retention Questionnaire (BHNRQ) at a 391-bed Magnet® redesignated community hospital were analyzed to explore differences in importance scores of bedside nurses. The results demonstrate that each of the 12 items on the BHNRQ was moderately to highly important. A multivariate analysis of variance based on generation, degree, unit, and experience revealed no significant differences on subscale scores (nursing practice, management, and staffing). Themes derived from the comment section on the BHNRQ were consistent with quantitative findings. Clinical and managerial competence, engagement with their employees, and presence on the unit are keys to retaining a satisfied nursing workforce.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ermanoski, Ivan; Orozco, Adrian

In this report we present the development of a packed particle bed recirculator and heat exchanger. The device is intended to create countercurrent flows of packed particle beds and exchange heat between the flows. The project focused on the design, fabrication, demonstration, and modifications of a simple prototype, in order to attain high levels of heat exchange between particle flows while maintaining an effective particle conveying rate in a scalable package. Despite heat losses in a package not optimized for heat retention, 50% heat recovery was achieved, at a particle conveying efficiency of 40%.

Fluidized bed reaction towards crystalline embedded amorphous Si anode with much enhanced cycling stability.

PubMed

Zhou, Yu; Guo, Huajun; Yan, Guochun; Wang, Zhixing; Li, Xinhai; Yang, Zhewei; Zheng, Anxiong; Wang, Jiexi

2018-04-10

A facile and large-scale fluidized bed reaction route was introduced for the first time to prepare crystalline embedded amorphous silicon nanoparticles with an average size of 50 nm as anode materials for lithium-ion batteries. By increasing the operating potential to control the electrochemically active degree, the resulting sample showed excellent cycle stability with a high capacity retention of 94.7% after 200 cycles at 1 A g-1 in the voltage range of 0.12-2.00 V.

Biofiltration of waste gases containing a mixture of formaldehyde and methanol.

PubMed

Prado, Oscar J; Veiga, María C; Kennes, Christian

2004-08-01

Several biofilters and biotrickling filters were used for the treatment of a mixture of formaldehyde and methanol; and their efficiencies were compared. Results obtained with three different inert filter bed materials (lava rock, perlite, activated carbon) suggested that the packing material had only little influence on the performance. The best results were obtained in a biotrickling filter packed with lava rock and fed a nutrient solution that was renewed weekly. A maximum formaldehyde elimination capacity of 180 g m(-3) h(-1) was reached, while the methanol elimination capacity rose occasionally to more than 600 g m(-3) h(-1). Formaldehyde degradation was affected by the inlet methanol concentration. Several combinations of load vs empty bed residence time (EBRTs of 71.9, 46.5, 30.0, 20.7 s) were studied, reaching a formaldehyde elimination capacity of 112 g m(-3) h(-1) with about 80% removal efficiency at the lowest EBRT (20.7 s).

Ignition of a granular propellant bed

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wildegger-Gaissmaier, A.E.; Johnston, I.R.

1996-08-01

An experimental and theoretical study is reported on the ignition process of a low vulnerability ammunition (LOVA) propellant bed in a 127-mm (5-in) bore gun charge. The theoretical investigation was with a two-phase flow interior ballistics code and the model predictions showed the marked influence the igniter system can have on pressure wave development, flame spreading, and the overall interior ballistics performance. A number of different igniter systems were investigated in an empty and propellant-filled gun simulator. Pressure, flame spreading, and high-speed film records were used to analyze the ignition/combustion event. The model predictions for flame spreading were confirmed qualitativelymore » by the experimental data. Full-scale instrumented gun firings were conducted with the optimized igniter design. Pressure waves were not detected in the charge during the firings. Model predictions on overall interior ballistics performance agreed well with the firing data.« less

Dust Storm, Aral Sea

NASA Technical Reports Server (NTRS)

2002-01-01

The Aral Sea has shrunk to less than half its size since 1985. The Aral Sea receives little water (sometimes no water) from the two major rivers that empty into it-the Syr Darya and Amu Darya. Instead, the river water is diverted to support irrigation for the region's extensive cotton fields. Recently, water scarcity has increased due to a prolonged drought in Central Asia. As the Aral Sea recedes, its former sea bed is exposed. The Aral's sea bed is composed of fine sediments-including fertilizers and other agricultural chemicals-that are easily picked up by the region's strong winds, creating thick dust storms. The International Space Station crew observed and recorded a large dust storm blowing eastward from the Aral Sea in late June 2001. This image illustrates the strong coupling between human activities (water diversions and irrigation), and rapidly changing land, sea and atmospheric processes-the winds blow across the

Biofiltration of methanol in an organic biofilter using peanut shells as medium.

PubMed

Ramirez-Lopez, E M; Corona-Hernandez, J; Avelar-Gonzalez, F J; Omil, F; Thalasso, F

2010-01-01

Biofiltration consists of a filter-bed of organic matter serving both as carrier for the active biomass and as nutrient supply, through which the polluted gas passes. The selection of a suitable medium material is of major importance to ensure optimum biofilter efficiency. Peanut shells are an agricultural byproduct locally available in large quantities at a low price in most tropical and sub-tropical countries. A previous study showed that peanut shells are physically and chemically suitable for biofiltration. This paper presents the results obtained during a six month biofiltration experiment using peanut shells as medium and methanol as air pollutant. It is shown that peanut shells are potentially suitable as biofiltration medium, since degradation rates of up to 30 kg MeOH/m(3)d with an empty bed residence time of 19s was obtained. The biofilter showed a good resistance to shock load and no operational problems were observed.

Herpes zoster-associated acute urinary retention: a case report.

PubMed

Julia, Jimmy J; Cholhan, Hilary J

2007-01-01

An 87-year-old woman presents with a 4-week history of urinary incontinence during which she had been treated for disseminated herpes zoster virus (HZV). On physical exam painful vesicles involving the entire vulvar region with mainly right sacral distribution were found. A catheterized volume exceeded 600 ml of retained urine after the patient failed to void spontaneously. Multichannel voiding-pressure urodynamic studies revealed an acontractile neurogenic bladder with overflow incontinence. The patient was discharged on a conservative regimen with arrangement for visiting nurse services to perform intermittent self-catheterization twice daily. Urodynamic testing was repeated 10 weeks after initial symptoms. During voiding cystometry a biphasic increase in detrusor pressure of 15 cm H2O was observed with no increase in abdominal pressure. The patient emptied 400 ml with a postvoid residual of 300 ml. Recovery from HZV-associated bladder emptying dysfunction can be achieved usually through conservative management, including intermittent self-catheterization. Complete recovery time ranges from 4 to 10 weeks.

Features of the recovery process of the Kolka glacier after the disaster of 2002

NASA Astrophysics Data System (ADS)

Nosenko, G.; Rototaeva, O.; Nikitin, S.

2017-12-01

There were events that attracted attention by the grand scale of the glacial catastrophe and its consequences in the North Ossetia (Caucasus Mountains) in 2002. The Kolka Glacier was completely thrown out of its bed and formed a giant water-ice-stone flow, caused destruction and human deaths along the valley of the Genaldon River. The volcanic impact of Mount Kazbek was one of the key factors in this process. The recovery of a new glacier in the empty circus of the Kolka glacier began almost immediately. Currently, three streams of ice have closed in the rear zone of the circus, forming a joint ice massif on the bed. The dimensions of the glacier vary under the influence of both new conditions for the accumulation and melting of ice, and the features of the dynamics of the ice masses filling the vacated bed. This report describes the next stage of the state of the new Kolka glacier - relative stabilization - and analyzes the features of the process of its recovery based on the field observations data, modern space images and the data of changes in summer air temperatures and winter precipitation on the glacier area at the beginning of the 21st century. In recent years, the rate of increase in the area of the glacier does not exceed 0.015 km2 per year. By September 2016, its area reached 1.11 km2, the volume - about 0.044 km3. The conditions for the formation of a new glacier on the empty bottom of the circus differ significantly from the previous ones - when Kolka was restored in after a pulsation on the 1970s. In addition to increase in the summer air temperatures, the thermal balance in the circus has changed due to the increase of the open surface area of the bed and the lateral moraine. At the same time, the growth of the debris cover on the glacier restrains the melting process. Rockfalls and avalanches supply moraine material to the surface of the glacier more intensively than in the 1970s. The conditions of accumulation also changed - the volume of food supplied from the hanging glaciers decreased from the previous 31% to 17%. Fumarolic activity in the crown area of the starboard side of the circus is preserved and this circumstance the restoration of the Kolka glacier.

Optimization of the pyrolysis process of empty fruit bunch (EFB) in a fixed-bed reactor through a central composite design (CCD)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mohamed, Alina Rahayu; Hamzah, Zainab; Daud, Mohamed Zulkali Mohamed

2014-07-10

The production of crude palm oil from the processing of palm fresh fruit bunches in the palm oil mills in Malaysia hs resulted in a huge quantity of empty fruit bunch (EFB) accumulated. The EFB was used as a feedstock in the pyrolysis process using a fixed-bed reactor in the present study. The optimization of process parameters such as pyrolysis temperature (factor A), biomass particle size (factor B) and holding time (factor C) were investigated through Central Composite Design (CCD) using Stat-Ease Design Expert software version 7 with bio-oil yield considered as the response. Twenty experimental runs were conducted. Themore » results were completely analyzed by Analysis of Variance (ANOVA). The model was statistically significant. All factors studied were significant with p-values < 0.05. The pyrolysis temperature (factor A) was considered as the most significant parameter because its F-value of 116.29 was the highest. The value of R{sup 2} was 0.9564 which indicated that the selected factors and its levels showed high correlation to the production of bio-oil from EFB pyrolysis process. A quadratic model equation was developed and employed to predict the highest theoretical bio-oil yield. The maximum bio-oil yield of 46.2 % was achieved at pyrolysis temperature of 442.15 °C using the EFB particle size of 866 μm which corresponded to the EFB particle size in the range of 710–1000 μm and holding time of 483 seconds.« less

Coal-Packed Methane Biofilter for Mitigation of Green House Gas Emissions from Coal Mine Ventilation Air

PubMed Central

Limbri, Hendy; Gunawan, Cindy; Thomas, Torsten; Smith, Andrew; Scott, Jason; Rosche, Bettina

2014-01-01

Methane emitted by coal mine ventilation air (MVA) is a significant greenhouse gas. A mitigation strategy is the oxidation of methane to carbon dioxide, which is approximately twenty-one times less effective at global warming than methane on a mass-basis. The low non-combustible methane concentrations at high MVA flow rates call for a catalytic strategy of oxidation. A laboratory-scale coal-packed biofilter was designed and partially removed methane from humidified air at flow rates between 0.2 and 2.4 L min−1 at 30°C with nutrient solution added every three days. Methane oxidation was catalysed by a complex community of naturally-occurring microorganisms, with the most abundant member being identified by 16S rRNA gene sequence as belonging to the methanotrophic genus Methylocystis. Additional inoculation with a laboratory-grown culture of Methylosinus sporium, as investigated in a parallel run, only enhanced methane consumption during the initial 12 weeks. The greatest level of methane removal of 27.2±0.66 g methane m−3 empty bed h−1 was attained for the non-inoculated system, which was equivalent to removing 19.7±2.9% methane from an inlet concentration of 1% v/v at an inlet gas flow rate of 1.6 L min−1 (2.4 min empty bed residence time). These results show that low-cost coal packing holds promising potential as a suitable growth surface and contains methanotrophic microorganisms for the catalytic oxidative removal of methane. PMID:24743729

Optimization of the pyrolysis process of empty fruit bunch (EFB) in a fixed-bed reactor through a central composite design (CCD)

NASA Astrophysics Data System (ADS)

Mohamed, Alina Rahayu; Hamzah, Zainab; Daud, Mohamed Zulkali Mohamed

2014-07-01

The production of crude palm oil from the processing of palm fresh fruit bunches in the palm oil mills in Malaysia hs resulted in a huge quantity of empty fruit bunch (EFB) accumulated. The EFB was used as a feedstock in the pyrolysis process using a fixed-bed reactor in the present study. The optimization of process parameters such as pyrolysis temperature (factor A), biomass particle size (factor B) and holding time (factor C) were investigated through Central Composite Design (CCD) using Stat-Ease Design Expert software version 7 with bio-oil yield considered as the response. Twenty experimental runs were conducted. The results were completely analyzed by Analysis of Variance (ANOVA). The model was statistically significant. All factors studied were significant with p-values < 0.05. The pyrolysis temperature (factor A) was considered as the most significant parameter because its F-value of 116.29 was the highest. The value of R2 was 0.9564 which indicated that the selected factors and its levels showed high correlation to the production of bio-oil from EFB pyrolysis process. A quadratic model equation was developed and employed to predict the highest theoretical bio-oil yield. The maximum bio-oil yield of 46.2 % was achieved at pyrolysis temperature of 442.15 °C using the EFB particle size of 866 μm which corresponded to the EFB particle size in the range of 710-1000 μm and holding time of 483 seconds.

Combustion characteristics and arsenic retention during co-combustion of agricultural biomass and bituminous coal.

PubMed

Zhou, Chuncai; Liu, Guijian; Wang, Xudong; Qi, Cuicui; Hu, Yunhu

2016-08-01

A combination of thermogravimetric analysis (TG) and laboratory-scale circulated fluidized bed combustion experiment was conducted to investigate the thermochemical, kinetic and arsenic retention behavior during co-combustion bituminous coal with typical agricultural biomass. Results shown that ignition performance and thermal reactivity of coal could be enhanced by adding biomass in suitable proportion. Arsenic was enriched in fly ash and associated with fine particles during combustion of coal/biomass blends. The emission of arsenic decreased with increasing proportion of biomass in blends. The retention of arsenic may be attributed to the interaction between arsenic and fly ash components. The positive correlation between calcium content and arsenic concentration in ash suggesting that the arsenic-calcium interaction may be regarded as the primary mechanism for arsenic retention. Copyright © 2016 Elsevier Ltd. All rights reserved.

Enhancing Drug Court Success

ERIC Educational Resources Information Center

Deschenes, Elizabeth Piper; Ireland, Connie; Kleinpeter, Christine B.

2009-01-01

This study evaluates the impact of enhanced drug court services in a large county in Southern California. These enhanced services, including specialty counseling groups, educational/employment resources, and increased Residential Treatment (RT) beds, were designed to increase program retention and successful completion (graduation) of drug court.…

An Analysis of First Duty Station Placement and New Graduate Transition Education on Retention in the Navy Nurse Corps

DTIC Science & Technology

2010-03-01

coronary by-pass (CABG) surgery patients would stay in the Coronary Care Step-Down Unit for at least a week while not getting out of bed for most of that...time. Whereas today, those same patients are out of the bed, sitting up in a chair within hours of surgery and sent home 48 hours post surgery ...hospital, flat on their backs, for a week and spend months at home recovering. Today, the surgery is done as a same-day surgery procedure and patients

Race/Ethnicity, Education, and Treatment Parameters as Moderators and Predictors of Outcome in Binge Eating Disorder

PubMed Central

Thompson-Brenner, Heather; Franko, Debra L.; Thompson, Douglas R.; Grilo, Carlos M.; Boisseau, Christina L.; Roehrig, James P.; Richards, Lauren K.; Bryson, Susan W.; Bulik, Cynthia M.; Crow, Scott J.; Devlin, Michael J.; Gorin, Amy A.; Kristeller, Jean L.; Masheb, Robin; Mitchell, James E.; Peterson, Carol B.; Safer, Debra L.; Striegel, Ruth H.; Wilfley, Denise E.; Wilson, G. Terence

2014-01-01

Objective Binge eating disorder (BED) is prevalent among individuals from minority racial/ethnic groups and among individuals with lower levels of education, yet the efficacy of psychosocial treatments for these groups has not been examined in adequately powered analyses. This study investigated the relative variance in treatment retention and post-treatment symptom levels accounted for by demographic, clinical, and treatment variables as moderators and predictors of outcome. Method Data were aggregated from eleven randomized, controlled trials of psychosocial treatments for BED conducted at treatment sites across the United States. Participants were N = 1,073 individuals meeting criteria for BED including n = 946 Caucasian, n = 79 African American, and n = 48 Hispanic/Latino participants. Approximately 86% had some higher education; 85% were female. Multi-level regression analyses examined moderators and predictors of treatment retention, Eating Disorder Examination (EDE) global score, frequency of objective bulimic episodes (OBEs), and OBE remission. Results Moderator analyses of race/ethnicity and education were non-significant. Predictor analyses revealed African Americans were more likely to drop out of treatment than Caucasians, and lower level of education predicted greater post-treatment OBEs. African Americans showed a small but significantly greater reduction in EDE global score relative to Caucasians. Self-help treatment administered in a group showed negative outcomes relative to other treatment types, and longer treatment was associated with better outcome. Conclusions Observed lower treatment retention among African Americans and lesser treatment effects for individuals with lower levels of educational attainment are serious issues requiring attention. Reduced benefit was observed for shorter treatment length and self-help administered in groups. PMID:23647283

The effect of nitrate on ethylene biofiltration.

PubMed

Lee, Sang-Hun; Li, Congna; Heber, Albert J

2012-11-30

This study investigated the effects of filter media types and nitrate (NO(3)(-)) concentrations in nutrient solutions on C(2)H(4) biofiltration. A new nutrient solution with zero NO(3)(-) concentration was supplied to two perlite-bed biotrickling filters, two perlite-bed biofilters, and two GAC (Granular Activated Carbon)-bed biofilters, while the other with 2 g L(-1) of NO(3)(-) was used for the other two GAC biofilters. All reactors underwent a total test duration of over 175 days with an EBRT (Empty Bed Residence Time) of 30 s, inlet gas flow rate of 7 L min(-1), and inlet C(2)H(4) concentrations of 20-30 mg m(-3). NO(3)(-) concentration and media type significantly affected the C(2)H(4) removal efficiencies in all types of biofiltration. The perlite media with no NO(3)(-) achieved C(2)H(4) removal efficiencies 10-50% higher than the others. A NO(3)(-) concentration as high as 2 g L(-1) in the original nutrient solution may act as an inhibitor that suppresses the growth or activity of C(2)H(4) degraders. In addition, the perlite media resulted in higher C(2)H(4) removal efficiencies than GAC media, because the hydrophilic surface of the perlite leads to a higher moisture content and thus to favorable microbial growth. Copyright © 2012 Elsevier B.V. All rights reserved.

History of the 4th Battalion, 37th Armored Regiment in Operation Desert Shield/Storm. Volume 2

DTIC Science & Technology

1992-04-15

model white Toyota truck pulled into the LOGPAC area. An Arab jumped out of the driver’s side of the vehicle and grabbed a five gallon can out of the...truck bed. He looked at SGT Stephen I. Lee, the D Co supply sergeant, and asked, "Gauss? Gauss?" The Toyota truck was parked one hundred meters away...from the Toyota truck and began to happily roll an empty fifty-five gallon drum off the truck. Seeing as how I did not suffer from the same hearing

Increasing Registered Nurse Retention Using Mentors in Critical Care Services.

PubMed

Schroyer, Coreena C; Zellers, Rebecca; Abraham, Sam

2016-01-01

Recruiting and training 1 newly hired registered nurse can cost thousands of dollars. With a high percentage of these newly hired nurses leaving their first place of employment within their first year, the financial implications may be enormous. It is imperative that health care facilities invest in recruiting and retention programs that retain high-quality nurses. Mentorship programs in retaining and easing the transition to practice for new graduate nurses, re-entry nurses, and nurses new to a specialty area are critical in nurse retention. Discussion in this study includes the effect of implementing a mentor program into the critical care services area of a 325-bed not-for-profit community hospital in northern Indiana. Based on this study, nurses with a mentor were retained at a 25% higher rate than those not mentored. Implementation of a mentor program reduced the training cost to the facility and increased retention and morale.

Contactor/filter improvements

DOEpatents

Stelman, D.

1988-06-30

A contactor/filter arrangement for removing particulate contaminants from a gaseous stream is described. The filter includes a housing having a substantially vertically oriented granular material retention member with upstream and downstream faces, a substantially vertically oriented microporous gas filter element, wherein the retention member and the filter element are spaced apart to provide a zone for the passage of granular material therethrough. A gaseous stream containing particulate contaminants passes through the gas inlet means as well as through the upstream face of the granular material retention member, passing through the retention member, the body of granular material, the microporous gas filter element, exiting out of the gas outlet means. A cover screen isolates the filter element from contact with the moving granular bed. In one embodiment, the granular material is comprised of porous alumina impregnated with CuO, with the cover screen cleaned by the action of the moving granular material as well as by backflow pressure pulses. 6 figs.

Postural Instability Caused by Extended Bed Rest Is Alleviated by Brief Daily Exposure to Low Magnitude Mechanical Signals

PubMed Central

Muir, Jesse; Judex, Stefan; Qin, Yi-Xian; Rubin, Clinton

2011-01-01

Loss of postural stability, as exacerbated by chronic bed rest, aging, neuromuscular injury or disease, results in a marked increase in the risk of falls, potentiating severe injury and even death. To investigate the capacity of low magnitude mechanical signals (LMMS) to retain postural stability under conditions conducive to its decline, twenty-nine healthy adult subjects underwent 90 days of 6-degree head down tilt bed-rest. Treated subjects underwent a daily 10 minute regimen of 30 Hz LMMS at either a 0.3g-force (n=12) or 0.5g force (n=5). Control subjects (n=13) received no LMMS treatment. Postural stability, quantified by dispersions of the plantar-based center of pressure, deteriorated significantly from baseline in control subjects, with displacement and velocity at 60d increasing 98.7% and 193% respectively, while the LMMS group increased only 26.7% and 6.4%, reflecting a 73% and 97% relative retention in stability as compared to control. Increasing LMMS magnitude from 0.3 to 0.5g had no significant influence on outcomes. LMMS failed to spare loss of muscle extension strength, but helped to retain flexion strength (e.g., 46.2% improved retention of baseline concentric flexion strength vs. untreated controls; p=0.01). These data suggest the potential of extremely small mechanical signals as a non-invasive means of preserving postural control under the challenge of chronic bed rest, and may ultimately represent non-pharmacologic means of reducing the risk of debilitating falls in elderly and infirm. PMID:21273076

Temporal variations in the potential hydrological performance of extensive green roof systems

NASA Astrophysics Data System (ADS)

De-Ville, Simon; Menon, Manoj; Stovin, Virginia

2018-03-01

Existing literature provides contradictory information about variation in potential green roof hydrological performance over time. This study has evaluated a long-term hydrological monitoring record from a series of extensive green roof test beds to identify long-term evolutions and sub-annual (seasonal) variations in potential hydrological performance. Monitoring of nine differently-configured extensive green roof test beds took place over a period of 6 years in Sheffield, UK. Long-term evolutions and sub-annual trends in maximum potential retention performance were identified through physical monitoring of substrate field capacity over time. An independent evaluation of temporal variations in detention performance was undertaken through the fitting of reservoir-routing model parameters. Aggregation of the resulting retention and detention variations permitted the prediction of extensive green roof hydrological performance in response to a 1-in-30-year 1-h summer design storm for Sheffield, UK, which facilitated the comparison of multi and sub-annual hydrological performance variations. Sub-annual (seasonal) variation was found to be significantly greater than long-term evolution. Potential retention performance increased by up to 12% after 5-years, whilst the maximum sub-annual variation in potential retention was 27%. For vegetated roof configurations, a 4% long-term improvement was observed for detention performance, compared to a maximum 63% sub-annual variation. Consistent long-term reductions in detention performance were observed in unvegetated roof configurations, with a non-standard expanded-clay substrate experiencing a 45% reduction in peak attenuation over 5-years. Conventional roof configurations exhibit stable long-term hydrological performance, but are nonetheless subject to sub-annual variation.

Biofiltration of methane using hybrid mixtures of biochar, lava rock and compost.

PubMed

La, Helen; Hettiaratchi, J Patrick A; Achari, Gopal; Verbeke, Tobin J; Dunfield, Peter F

2018-05-21

Using hybrid packing materials in biofiltration systems takes advantage of both the inorganic and organic properties offered by the medium including structural stability and a source of available nutrients, respectively. In this study, hybrid mixtures of compost with either lava rock or biochar in four different mixture ratios were compared against 100% compost in a methane biofilter with active aeration at two ports along the height of the biofilter. Biochar outperformed lava rock as a packing material by providing the added benefit of participating in sorption reactions with CH 4 . This study provides evidence that a 7:1 volumetric mixture of biochar and compost can successfully remove up to 877 g CH 4 /m 3 ·d with empty-bed residence times of 82.8 min. Low-affinity methanotrophs were responsible for the CH 4 removal in these systems (K M(app) ranging from 5.7 to 42.7 µM CH 4 ). Sequencing of 16S rRNA gene amplicons indicated that Gammaproteobacteria methanotrophs, especially members of the genus Methylobacter, were responsible for most of the CH 4 removal. However, as the compost medium was replaced with more inert medium, there was a decline in CH 4 removal efficiency coinciding with an increased dominance of Alphaproteobacteria methanotrophs like Methylocystis and Methylocella. As a biologically-active material, compost served as the sole source of nutrients and inoculum for the biofilters which greatly simplified the operation of the system. Higher elimination capacities may be possible with higher compost content such as a 1:1 ratio of either biochar or lava rock, while maintaining the empty-bed residence time at 82.8 min. Copyright © 2018 Elsevier Ltd. All rights reserved.

Long-term fuel retention and release in JET ITER-Like Wall at ITER-relevant baking temperatures

NASA Astrophysics Data System (ADS)

Heinola, K.; Likonen, J.; Ahlgren, T.; Brezinsek, S.; De Temmerman, G.; Jepu, I.; Matthews, G. F.; Pitts, R. A.; Widdowson, A.; Contributors, JET

2017-08-01

The fuel outgassing efficiency from plasma-facing components exposed in JET-ILW has been studied at ITER-relevant baking temperatures. Samples retrieved from the W divertor and Be main chamber were annealed at 350 and 240 °C, respectively. Annealing was performed with thermal desoprtion spectrometry (TDS) for 0, 5 and 15 h to study the deuterium removal effectiveness at the nominal baking temperatures. The remained fraction was determined by emptying the samples fully of deuterium by heating W and Be samples up to 1000 and 775 °C,respectively. Results showed the deposits in the divertor having an increasing effect to the remaining retention at temperatures above baking. Highest remaining fractions 54 and 87 % were observed with deposit thicknesses of 10 and 40 μm, respectively. Substantially high fractions were obtained in the main chamber samples from the deposit-free erosion zone of the limiter midplane, in which the dominant fuel retention mechanism is via implantation: 15 h annealing resulted in retained deuterium higher than 90 % . TDS results from the divertor were simulated with TMAP7 calculations. The spectra were modelled with three deuterium activation energies resulting in good agreement with the experiments.

Pyrolysis of Date palm waste in a fixed-bed reactor: Characterization of pyrolytic products.

PubMed

Bensidhom, Gmar; Ben Hassen-Trabelsi, Aïda; Alper, Koray; Sghairoun, Maher; Zaafouri, Kaouther; Trabelsi, Ismail

2018-01-01

The pyrolysis of several Tunisian Date Palm Wastes (DPW): Date Palm Rachis (DPR), Date Palm Leaflets (DPL), Empty Fruit Bunches (EFB) and Date Palm Glaich (DPG) was run using a fixed-bed reactor, from room temperature to 500°C, with 15°C/min as heating rate and -5°C as condensation temperature, in order to produce bio-oil, biochar and syngas. In these conditions, the bio-oil yield ranges from 17.03wt% for DPL to 25.99wt% for EFB. For the biochar, the highest yield (36.66wt%) was obtained for DPL and the lowest one (31.66wt%) was obtained from DPG while the syngas production varies from 39.10wt% for DPR to 46.31wt% DPL. The raw material and pyrolysis products have been characterized using elemental analysis thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM). The syngas composition has been characterized using gas analyzer. Copyright © 2017 Elsevier Ltd. All rights reserved.

Neural mechanisms and delayed gastric emptying of liquid induced through acute myocardial infarction in rats.

PubMed

Nunez, Wilson Ranu Ramirez; Ozaki, Michiko Regina; Vinagre, Adriana Mendes; Collares, Edgard Ferro; Almeida, Eros Antonio de

2015-02-01

In pathological situations, such as acute myocardial infarction, disorders of motility of the proximal gut can trigger symptoms like nausea and vomiting. Acute myocardial infarction delays gastric emptying (GE) of liquid in rats. Investigate the involvement of the vagus nerve, α 1-adrenoceptors, central nervous system GABAB receptors and also participation of paraventricular nucleus (PVN) of the hypothalamus in GE and gastric compliance (GC) in infarcted rats. Wistar rats, N = 8-15 in each group, were divided as INF group and sham (SH) group and subdivided. The infarction was performed through ligation of the left anterior descending coronary artery. GC was estimated with pressure-volume curves. Vagotomy was performed by sectioning the dorsal and ventral branches. To verify the action of GABAB receptors, baclofen was injected via icv (intracerebroventricular). Intravenous prazosin was used to produce chemical sympathectomy. The lesion in the PVN of the hypothalamus was performed using a 1 mA/10 s electrical current and GE was determined by measuring the percentage of gastric retention (% GR) of a saline meal. No significant differences were observed regarding GC between groups; vagotomy significantly reduced % GR in INF group; icv treatment with baclofen significantly reduced %GR. GABAB receptors were not conclusively involved in delaying GE; intravenous treatment with prazosin significantly reduced GR% in INF group. PVN lesion abolished the effect of myocardial infarction on GE. Gastric emptying of liquids induced through acute myocardial infarction in rats showed the involvement of the vagus nerve, alpha1- adrenergic receptors and PVN.

[Scintigraphic study of gastric emptying of rehydration drinks in athletes].

PubMed

Martínez Gonzálvez, A B; Nuño de la Rosa Y Pozuelo, J A; Sánchez Gascón, F; Villegas García, J A; Mulero Aniorte, F; Contreras Gutiérrez, J C

2005-01-01

This study aims to evaluate how rehydration beverage ingestion influences gastric emptying rate (in cycle ergometer) at rest and during exercise at 70 % of maximal oxygen consumption (VO2max). 26 well-trained cyclists performed a preliminary maximal test until exhaustion to evaluate their VO2max, and two submaximal exercise tests at 70 % of their mode-specific VO2max. Each test was separated by one week. During the two submaximal tests, cyclists consumed 200 ml of a 99mTc-DTPA labeled rehydration beverage (A or B) and scintigraphy determinations were performed at rest. After, exercise was initiated for 60 minutes with an intake rate of 200 ml every 15 minutes, making gastric serial scintigraphy determinations. The difference regarding chemical composition between A and B drinks resides in the fact that drink A contains a smaller load in carbohydrates (10.3 g/100 ml versus 15.2 g/100 ml of B), proteins in form of serum milk and antioxidants in form of fruit juice. Both contain ions and vitamins. at rest, gastric count number was significantly reduced (p > 0.000) from 0 to 25 minutes for both A and B beverage. At the end of exercise (60 min), there was greater gastric retention for B beverage than for A, this difference being statistically significant (p < 0.031). The A beverage, a rehydration drink on the market with protein and antioxidants with fruit juice content, has a faster gastric emptying rate than the B sport beverage.

Media arrangement impacts cell growth in anaerobic fixed-bed reactors treating sugarcane vinasse: Structured vs. randomic biomass immobilization.

PubMed

de Aquino, Samuel; Fuess, Lucas Tadeu; Pires, Eduardo Cleto

2017-07-01

This study reports on the application of an innovative structured-bed reactor (FVR) as an alternative to conventional packed-bed reactors (PBRs) to treat high-strength solid-rich wastewaters. Using the FVR prevents solids from accumulating within the fixed-bed, while maintaining the advantages of the biomass immobilization. The long-term operation (330days) of a FVR and a PBR applied to sugarcane vinasse under increasing organic loads (2.4-18.0kgCODm -3 day -1 ) was assessed, focusing on the impacts of the different media arrangements over the production and retention of biomass. Much higher organic matter degradation rates, as well as long-term operational stability and high conversion efficiencies (>80%) confirmed that the FVR performed better than the PBR. Despite the equivalent operating conditions, the biomass growth yield was different in both reactors, i.e., 0.095gVSSg -1 COD (FVR) and 0.066gVSSg -1 COD (PBR), indicating a clear control of the media arrangement over the biomass production in fixed-bed reactors. Copyright © 2017 Elsevier Ltd. All rights reserved.

Percolation behavior of tritiated water into a soil packed bed

DOE Office of Scientific and Technical Information (OSTI.GOV)

Honda, T.; Katayama, K.; Uehara, K.

2015-03-15

A large amount of cooling water is used in a D-T fusion reactor. The cooling water will contain tritium with high concentration because tritium can permeate metal walls at high temperature easily. A development of tritium handling technology for confining tritiated water in the fusion facility is an important issue. In addition, it is also important to understand tritium behavior in environment assuming severe accidents. In this study, percolation experiments of tritiated water in soil packed bed were carried out and tritium behavior in soil was discussed. Six soil samples were collected in Hakozaki campus of Kyushu University. These particlemore » densities were of the same degree as that of general soils and moisture contents were related to BET surface area. For two soil samples used in the percolation experiment of tritiated water, saturated hydraulic conductivity agreed well with the estimating value by Creager. Tritium retention ratio in the soil packed bed was larger than water retention. This is considered to be due to an effect of tritium sorption on the surface of soil particles. The isotope exchange capacity estimated by assuming that H/T ratio of supplied tritiated water and H/T ratio of surface water of soil particle was equal was comparable to that on cement paste and mortar which were obtained by exposure of tritiated water vapor. (authors)« less

Oral and intravenous l-[1-13 C]phenylalanine delivery measure similar rates of elimination when gastric emptying and splanchnic extraction are accounted for in adult mixed hounds.

PubMed

Gooding, M A; Cant, J P; Pencharz, P B; Davenport, G M; Atkinson, J L; Shoveller, A K

2013-02-01

There are few reported estimates of amino acid (AA) kinetics in adult mammals and none exist in adult dogs. The study objectives were to evaluate the use of oral isotope delivery in contrast to the more commonly used intravenous (IV) delivery to estimate AA kinetics in adult dogs and to estimate splanchnic extraction and gastric emptying using a commonly accepted mathematical model. Dogs received 25 × 1/2-hourly meals (13 g/kg BW/day) and either an oral or IV bolus of l-[1-(13) C]Phe (12 mg/kg BW). Blood samples were taken immediately before each feeding. Concentrations of plasma Phe were measured using liquid chromatography-tandem mass spectrometry. There were no differences in baseline plasma Phe concentrations (34 μm ± 0.61), Phe distribution volume, Phe pool size and rate constants between dogs when the tracer was administered IV or orally (p > 0.25). Decay curve for plasma l-[1-(13) C]Phe differed between IV and oral dosing protocols with IV dosing fit best using a two-compartment model. Phe disappeared from plasma at a mean rate of 2.8%/min. Estimates of gastric emptying and splanchnic extraction did not differ based on oral or IV tracer dosing when the decay curves were fit with the two-compartment model (p > 0.40). The half-life for gastric emptying was 18 min, and first-pass Phe extraction by the splanchnic bed was 24% of the dietary Phe. These results suggest that oral isotope dosing can be used as an alternative to IV isotope dosing in studies that utilize a primed, constant dosing approach to measure protein and amino acid kinetics. © 2011 Blackwell Verlag GmbH.

Transport and retention of phosphorus in surface water in an urban slum area

NASA Astrophysics Data System (ADS)

Nyenje, P. M.; Meijer, L. M. G.; Foppen, J. W.; Kulabako, R.; Uhlenbrook, S.

2013-08-01

The transport of excessive phosphorus (P) discharged from unsewered informal settlements (slums) due to poor on-site sanitation is largely unknown. Hence, we investigated the processes governing P transport in a 28 km2 slum-dominated catchment in Kampala, Uganda. During high runoff events and a period of base flow, we collected hourly water samples (over 24 h) from a primary channel draining the catchment and from a small size tertiary channel draining one of the contributing slum areas (0.5 km2). Samples were analyzed for orthophosphate (PO4-P), particulate P (PP), total P (TP) and selected hydro-chemical parameters. Channel bed and suspended sediments were collected to determine their sorption potential, geo-available metals and dominant P forms. We found that P inputs in the catchment originated mainly from domestic wastewater as evidenced by high concentrations of Cl (36-144 mg L-1), HCO3 and other cations in the channels. Most P discharged during low flow conditions was particulate implying that much of it was retained in bed sediments. Retained P was mostly bound to Ca and Fe/Al oxides. Hence, we inferred that mineral precipitation and adsorption to Ca-minerals were the dominant P retention processes. Bed sediments were P-saturated and showed a tendency to release P to discharging waters. P released was likely due to Ca-bound P because of the strong correlation between Ca and total P in sediments (r2 = 0.9). High flows exhibited a strong flush of PP and SS implying that part of P retained was frequently flushed out of the catchment by surface erosion and resuspension of bed sediment. Our findings suggest that P accumulated in the channel bed during low flows and then was slowly released into surface water. Hence, it will likely take some time, even with improved wastewater management practices, before P loads to downstream areas can be significantly reduced.

Coupling Solute and Fine Particle Transport with Sand Bed Morphodynamics within a Field Experiment

NASA Astrophysics Data System (ADS)

Phillips, C. B.; Ortiz, C. P.; Schumer, R.; Jerolmack, D. J.; Packman, A. I.

2017-12-01

Fine suspended particles are typically considered to pass through streams and rivers as wash load without interacting with the bed, however experiments have demonstrated that hyporheic flow causes advective exchange of fine particles with the stream bed, yielding accumulation of fine particle deposits within the bed. Ultimately, understanding river morphodynamics and ecosystem dynamics requires coupling both fine particle and solute transport with bed morphodynamics. To better understand the coupling between these processes we analyze a novel dataset from a controlled field experiment conducted on Clear Run, a 2nd order sand bed stream located within the North Carolina coastal plain. Data include concentrations of continuously injected conservative solutes and fine particulate tracers measured at various depths within the stream bed, overhead time lapse images of bed forms, stream discharge, and geomorphological surveys of the stream. We use image analysis of bed morphodynamics to assess exchange, retention, and remobilization of solutes and fine particles during constant discharge and a short duration experimental flood. From the images, we extract a time series of bedform elevations and scour depths for the duration of the experiment. The high-resolution timeseries of bed elevation enables us to assess coupling of bed morphodynamics with both the solute and fine particle flux during steady state mobile bedforms prior to the flood and to changing bedforms during the flood. These data allow the application of a stochastic modeling framework relating bed elevation fluctuations to fine particle residence times. This combined experimental and modeling approach ultimately informs our ability to predict not only the fate of fine particulate matter but also associated nutrient and carbon dynamics within streams and rivers.

Synthesis optimization of oil palm empty fruit bunch and rice husk biochars for removal of imazapic and imazapyr herbicides.

PubMed

Yavari, Saba; Malakahmad, Amirhossein; Sapari, Nasiman B; Yavari, Sara

2017-05-15

Imidazolinones are a family of herbicides that are used to control a broad range of weeds. Their high persistence and leaching potential make them probable risk to the ecosystems. In this study, biochar, the biomass-derived solid material, was produced from oil palm empty fruit bunches (EFB) and rice husk (RH) through pyrolysis process. Feedstock and pyrolysis variables can control biochar sorption capacity. Therefore, the present study attempts to evaluate effects of three pyrolysis variables (temperature, heating rate and retention time) on abilities of biochars for removal of imazapic and imazapyr herbicides from soil. Response surface methodology (RSM) was used for optimizing the variables to achieve maximum sorption performance of the biochars. Experimental data were interpreted accurately by quadratic models. Based on the results, sorption capacities of both biochars raised when temperature decreased to 300 °C, mainly because of increased biochars effective functionality in sorption of polar molecules. Heating rate of 3°C/min provided optimum conditions to maximize the sorption capacities of both biochars. Retention time of about 1 h and 3 h were found to be the best for EFB and RH biochars, respectively. EFB biochar was more efficient in removal of the herbicides, especially imazapyr due to its chemical composition and higher polarity index (0.42) rather than RH biochar (0.39). Besides, higher cation exchange capacity (CEC) values of EFB biochar (83.90 cmol c /kg) in comparison with RH biochar (70.73 cmol c /kg) represented its higher surface polarity effective in sorption of the polar herbicides. Copyright © 2017 Elsevier Ltd. All rights reserved.

An interpolated activity during the knowledge-of-results delay interval eliminates the learning advantages of self-controlled feedback schedules.

PubMed

Carter, Michael J; Ste-Marie, Diane M

2017-03-01

The learning advantages of self-controlled knowledge-of-results (KR) schedules compared to yoked schedules have been linked to the optimization of the informational value of the KR received for the enhancement of one's error-detection capabilities. This suggests that information-processing activities that occur after motor execution, but prior to receiving KR (i.e., the KR-delay interval) may underlie self-controlled KR learning advantages. The present experiment investigated whether self-controlled KR learning benefits would be eliminated if an interpolated activity was performed during the KR-delay interval. Participants practiced a waveform matching task that required two rapid elbow extension-flexion reversals in one of four groups using a factorial combination of choice (self-controlled, yoked) and KR-delay interval (empty, interpolated). The waveform had specific spatial and temporal constraints, and an overall movement time goal. The results indicated that the self-controlled + empty group had superior retention and transfer scores compared to all other groups. Moreover, the self-controlled + interpolated and yoked + interpolated groups did not differ significantly in retention and transfer; thus, the interpolated activity eliminated the typically found learning benefits of self-controlled KR. No significant differences were found between the two yoked groups. We suggest the interpolated activity interfered with information-processing activities specific to self-controlled KR conditions that occur during the KR-delay interval and that these activities are vital for reaping the associated learning benefits. These findings add to the growing evidence that challenge the motivational account of self-controlled KR learning advantages and instead highlights informational factors associated with the KR-delay interval as an important variable for motor learning under self-controlled KR schedules.

Biodegradation of toluene vapor in coir based upflow packed bed reactor by Trichoderma asperellum isolate.

PubMed

Gopinath, M; Mohanapriya, C; Sivakumar, K; Baskar, G; Muthukumaran, C; Dhanasekar, R

2016-03-01

In the present study, a new biofiltration system involving a selective microbial strain isolated from aerated municipal sewage water attached with coir as packing material was developed for toluene degradation. The selected fungal isolate was identified as Trichoderma asperellum by 16S ribosomal RNA (16S rRNA) sequencing method, and pylogenetic tree was constructed using BLASTn search. Effect of various factors on growth and toluene degradation by newly isolated T. asperellum was studied in batch studies, and the optimum conditions were found to be pH 7.0, temperature 30 °C, and initial toluene concentration 1.5 (v/v)%. Continuous removal of gaseous toluene was monitored in upflow packed bed reactor (UFPBR) using T. asperellum. Effect of various parameters like column height, flow rate, and the inlet toluene concentration were studied to evaluate the performance of the biofilter. The maximum elimination capacity (257 g m(-3) h(-1)) was obtained with the packing height of 100 cm with the empty bed residence time of 5 min. Under these optimum conditions, the T. asperellum showed better toluene removal efficiency. Kinetic models have been developed for toluene degradation by T. asperellum using macrokinetic approach of the plug flow model incorporated with Monod model.

Mechanical model testing of rebreathing potential in infant bedding materials

PubMed Central

Carleton, J.; Donoghue, A.; Porter, W.

1998-01-01

Rebreathing of expired air may be a lethal hazard for prone sleeping infants. This paper describes a mechanical model to simulate infant breathing, and examines the effects of bedding on exhaled air retention. Under simulated rebreathing conditions, the model allows the monitoring of raised carbon dioxide (CO2) inside an artificial lung-trachea system. Resulting levels of CO2 (although probably exaggerated in the mechanical model compared with an infant, due to the model's fixed breathing rate and volume) suggest that common bedding materials vary widely in inherent rebreathing potential. In face down tests, maximum airway CO2 ranged from less than 5% on sheets and waterproof mattresses to over 25% on sheepskins, bean bag cushions, and some pillows and comforters. Concentrations of CO2 decreased with increasing head angle of the doll, away from the face down position. Recreations of 29infant death scenes also showed large CO2 increases on some bedding materials, suggesting these infants could have died while rebreathing.

 PMID:9623394

Arsenic and selenium capture by fly ashes at low temperature

DOE Office of Scientific and Technical Information (OSTI.GOV)

M. Antonia Lopez-Anton; Mercedes Diaz-Somoano; D. Alan Spears

2006-06-15

Arsenic and selenium compounds may be emitted to the environment during coal conversion processes, although some compounds are retained in the fly ashes, in different proportions depending on the characteristics of the ashes and process conditions. The possibility of optimizing the conditions to achieve better trace element retention appears to be an attractive, economical option for reducing toxic emissions. This approach requires a good knowledge of fly ash characteristics and a thorough understanding of the capture mechanism involved in the retention. In this work the ability of two fly ashes, one produced in pulverized coal combustion and the other inmore » fluidized bed combustion, to retain arsenic and selenium compounds from the gas phase in coal combustion and coal gasification atmospheres was investigated. To explore the possible simultaneous retention of mercury, the influence of the unburned coal particle content was also evaluated. Retention capacities between 2 and 22 mg g{sup -1} were obtained under different conditions. The unburned coal particle content in the fly ash samples does not significantly modify retention capacities. 21 refs., 6 figs., 5 tabs.« less

Investigating waste rock, tailings, slag and coal ash clinker as adsorbents for heavy metals: Batch and column studies

NASA Astrophysics Data System (ADS)

Letina, D.; Letshwenyo, W. M.

2018-06-01

Wastewater from the mining industry is a concern because most of the time it contains heavy metals with concentrations above permissible levels, posing a threat to terrestrial and aquatic life. The study was conducted to evaluate the effectiveness of locally available waste materials (waste rock, tailings, coal ash clinker, and slag) generated by BCL (Ltd) mine, a copper and nickel mining and smelting company in Botswana, for removal of nickel and copper from the real mining wastewater. Batch adsorption studies were conducted to establish the adsorptive efficiency and kinetics of each media with respect to nickel and copper ions. The best media was further evaluated through fixed bed column studies at 24 and 48 h empty bed contact time. The results indicate that the percentage removal for coal ash clinker, waste rock, smelter slag and tailings was 98%, 15%, 3% and -3% with respect to copper ions, and 46%, 9%, 7% and 2% with respect to nickel ions for each media respectively. Coal ash clinker followed pseudo first order kinetic model and Langmuir isotherm model with respect to nickel ions indicating the dominance of physisorption and mono layer coverage respectively. The Langmuir separation factor (RL) was 0.37 suggesting favourable adsorption onto the media. Fixed bed column studies revealed that copper was completely retained in the bed at both 24 and 48 h contact times. In the case of nickel, removal efficiency ranged between 83% and 99% when contact time was 48 h and between 68% and 99% when the contact time was reduced to 24 h. Breakthrough was not reached after 19 bed volumes. It can be concluded that coal ash clinker is a better candidate for the removal of copper and nickel ions from mining wastewater.

Mathematical modeling of the adsorption/desorption characteristics of anthocyanins from muscadine (Vitis rotundifolia cv. Noble) juice pomace on Amberlite FPX66 resin in a fixed bed column.

PubMed

Uzdevenes, Chad G; Gao, Chi; Sandhu, Amandeep K; Yagiz, Yavuz; Gu, Liwei

2018-03-24

Muscadine grape pomace, a by-product of juicing and wine-making, contains significant amounts of anthocyanin 3,5-diglucosides, known to be beneficial to human health. The objective of this research was to use mathematical modeling to investigate the adsorption/desorption characteristics of these anthocyanins from muscadine grape pomace on Amberlite FPX66 resin in a fixed bed column. Anthocyanins were extracted using hot water and ultrasound, and the extracts were loaded onto a resin column at five bed depths (5, 6, 8, 10 and 12 cm) using three flow rates (4, 6 and 8 mL min -1 ). It was found that adsorption on the column fitted the bed depth service time (BDST) model and the empty bed residence time (EBRT) model. Desorption was achieved by eluting the column using ethanol at four concentrations (25, 40, 55 and 70% v/v) and could be described with an empirical sigmoid model. The breakthrough curves of anthocyanins fitted the BDST model for all three flow rates with R 2 values of 0.983, 0.992 and 0.984 respectively. The EBRT model was successfully employed to find the operating lines, which allow for column scale-up while still achieving similar results to those found in a laboratory operation. Desorption with 40% (v/v) ethanol achieved the highest recovery rate of anthocyanins at 79.6%. The mathematical models established in this study can be used in designing a pilot/industrial- scale column for the separation and concentration of anthocyanins from muscadine juice pomace. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

Control of dissolved CH4 in a municipal UASB reactor effluent by means of a desorption - Biofiltration arrangement.

PubMed

Huete, A; de Los Cobos-Vasconcelos, D; Gómez-Borraz, T; Morgan-Sagastume, J M; Noyola, A

2018-06-15

The direct anaerobic treatment of municipal wastewater represents an adapted technology to the conditions of developing countries. In order to get an increased acceptance of this technology, a proper control of dissolved methane in the anaerobic effluents should be considered, as methane is a potent greenhouse gas. In this study, a pilot-scale system was operated for 168 days to recover dissolved methane from an effluent of an upflow anaerobic sludge blanket reactor and then oxidize it in a compost biofilter. The system operated at a constant air (0.9 m 3 /h ±0.09) and two air-to anaerobic effluent ratio (1:1 and 1:2). In both conditions (CH 4 concentration of 2.7 ± 0.87 and 4.3% ± 1.14, respectively) the desorption column recovered 99% of the dissolved CH 4 and approximately 30% ± 8.5 of H 2 S, whose desorption was limited due to the high pH (>8) of the effluent. The biofilter removed 70% ± 8 of the average CH 4 load (60 gCH 4 /m 3 h ± 13) and 100% of the H 2 S load at an empty bed retention time of 23 min. The average temperature inside the biofilter was 42 ± 9 °C due to the CH 4 oxidation reaction, indicating that temperature and moisture control is particularly important for CH 4 removal in compost biofilters. The system may achieve a 54% reduction of greenhouse gas emissions from dissolved CH 4 in this particular case. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of Residence Time on Net Nitrate Retention in Flow-Regulated Backwaters of the Upper Mississippi River

DTIC Science & Technology

2006-02-01

include Ceratophyllum demersum, Myriophyllum spicatum, and Nymphaea odorata . METHODS: In late April 2004, vertical slide gates were adjusted to...due to a shallow water column and dense N. odorata beds. Flows into Schmokers Lake could not be directly measured because it was not connected to the

An Evaluation of a Shared Leadership Training Program

ERIC Educational Resources Information Center

Allen, Lavonda Ann

2010-01-01

The purpose of the quantitative quasi-experimental equivalent time series study was to evaluate the effectiveness of a work based shared leadership training program in a less than 200 bed hospital in rural, south-central United States. Nursing shortages and the current emphasis on quality are factors that make recruitment and retention of nurses…

Treatment of screened dairy manure by upflow anaerobic fixed bed reactors packed with waste tyre rubber and a combination of waste tyre rubber and zeolite: effect of the hydraulic retention time.

PubMed

Umaña, Oscar; Nikolaeva, Svetlana; Sánchez, Enrique; Borja, Rafael; Raposo, Francisco

2008-10-01

Two laboratory-scale anaerobic fixed bed reactors were evaluated while treating dairy manure at upflow mode and semicontinuous feeding. One reactor was packed with a combination of waste tyre rubber and zeolite (R1) while the other had only waste tyre rubber as a microorganism immobilization support (R2). Effluent quality improved when the hydraulic retention time (HRT) increased from 1.0 to 5.5 days. Higher COD, BOD5, total and volatile solids removal efficiencies were always achieved in the reactor R1. No clogging was observed during the operation period. Methane yield was also a function of the HRT and of the type of support used, and was 12.5% and 40% higher in reactor R1 than in R2 for HRTs of 5.5 and 1.0 days, respectively. The results obtained demonstrated that this type of reactor is capable of operating with dairy manure at a HRT 5 times lower than that used in a conventional reactor.

Biomass characteristics and simultaneous nitrification-denitrification under long sludge retention time in an integrated reactor treating rural domestic sewage.

PubMed

Gong, Lingxiao; Jun, Li; Yang, Qing; Wang, Shuying; Ma, Bin; Peng, Yongzhen

2012-09-01

In this work, a novel integrated reactor incorporating anoxic fixed bed biofilm reactor (FBBR), oxic moving bed biofilm reactor (MBBR) and settler sequentially was proposed for nitrogen removal from rural domestic sewage. For purposes of achieving high efficiency, low costs and easy maintenance, biomass characteristics and simultaneous nitrification-denitrification (SND) were investigated under long sludge retention time during a 149-day period. The results showed that enhanced SND with proportions of 37.7-42.2% tapped the reactor potentials of efficiency and economy both, despite of C/N ratio of 2.5-4.0 in influent. TN was removed averagely by 69.3% at least, even under internal recycling ratio of 200% and less proportions of biomass assimilation (<3%). Consequently, lower internal recycle and intermittent wasted sludge discharge were feasible to save costs, together with cancellations of sludge return and anoxic stir. Furthermore, biomass with low observed heterotrophic yields (0.053 ± 0.035 g VSS/g COD) and VSS/TSS ratio (<0.55) in MBBR, simplified wasted sludge disposal. Copyright © 2012 Elsevier Ltd. All rights reserved.

Influence of porosity and composition of supports on the methanogenic biofilm characteristics developed in a fixed bed anaerobic reactor.

PubMed

Picanço, A P; Vallero, M V; Gianotti, E P; Zaiat, M; Blundi, C E

2001-01-01

This paper reports on the influence of the material porosity on the anaerobic biomass adhesion on four different inert matrices: polyurethane foam, PVC, refractory brick and special ceramic. The biofilm development was performed in a fixed-bed anaerobic reactor containing all the support materials and fed with a synthetic wastewater containing protein, lipids and carbohydrates. The data obtained from microscopic analysis and kinetic assays indicated that the material porosity has a crucial importance in the retention of the anaerobic biomass. The polyurethane foam particles and the special ceramic were found to present better retentive properties than the PVC and the refractory brick. The large specific surface area, directly related to material porosity, is fundamental to provide a large amount of attached biomass. However, different supports can provide specific conditions for the adherence of distinct microorganism types. The microbiological exams revealed a distinction in the support colonization. A predominance of methanogenic archaeas resembling Methanosaeta was observed both in the refractory brick and the special ceramic. Methanosarcina-like microorganisms were predominant in the PVC and the polyurethane foam matrices.

Effect of bioparticle size on dispersion and retention in monolithic and perfusive beds

PubMed Central

Trilisky, Egor I.; Lenhoff, Abraham M.

2010-01-01

Single-component pulse response studies were used to compare the retention and transport behavior of small molecules, proteins, and a virus on commercially available monolithic and perfusive ion-exchangers. Temporal distortion and extra-column effects were corrected for using a simple algorithm based on the method of moments. It was found that temporal distortion is inversely related to the number of theoretical plates. With increasing bioparticle size, retention increased and the transition from a non-eluting to a non-adsorbing state with increasing ionic strength became more abrupt. Both of these observations are qualitatively explained by calculations of particle-surface electrostatic attractive energy. Calculations also show that, for sufficiently large bioparticles, such as viruses or cells, hydrodynamic drag can promote elution. Under non-adsorbing conditions, plate height increased only weakly with flow rate and the skew remained unchanged. With increasing retention, plate height increased dramatically for proteins. Plate height was scaled by permeability rather than bead diameter to enable comparison among different stationary phases. PMID:20951383

Combustion characteristics and retention-emission of selenium during co-firing of torrefied biomass and its blends with high ash coal.

PubMed

Ullah, Habib; Liu, Guijian; Yousaf, Balal; Ali, Muhammad Ubaid; Abbas, Qumber; Zhou, Chuncai

2017-12-01

The combustion characteristics, kinetic analysis and selenium retention-emission behavior during co-combustion of high ash coal (HAC) with pine wood (PW) biomass and torrefied pine wood (TPW) were investigated through a combination of thermogravimetric analysis (TGA) and laboratory-based circulating fluidized bed combustion experiment. Improved ignition behavior and thermal reactivity of HAC were observed through the addition of a suitable proportion of biomass and torrefied. During combustion of blends, higher values of relative enrichment factors in fly ash revealed the maximum content of condensing volatile selenium on fly ash particles, and depleted level in bottom ash. Selenium emission in blends decreased by the increasing ratio of both PW and TPW. Higher reductions in the total Se volatilization were found for HAC/TPW than individual HAC sample, recommending that TPW have the best potential of selenium retention. The interaction amongst selenium and fly ash particles may cause the retention of selenium. Copyright © 2017 Elsevier Ltd. All rights reserved.

Comparison of H2S adsorption by two hydrogel composite (HBC) derived by Empty Fruit Bunch (EFB) biochar and Coal Fly Ash (CFA)

NASA Astrophysics Data System (ADS)

Meri, N. H.; Alias, A. B.; Talib, N.; Rashid, Z. A.; Ghani, W. A. W. A. K.

2018-03-01

This study are covered the adsorption performance of two adsorbent Empty Fruit Bunch Hydrogel Biochar Composite (EFB-HBC) and Coal Fly Ash Hydrogel Composite (CFA-HC) on hydrogen sulphide. The EFB biochar were produce by pyrolysed and heated from room temperature to 550˚C at 10˚C/min under the Nitrogen flow. Meanwhile, coal fly ash collected from a power plant located in Selangor, Malaysia. Both of the materials is a waste from different industries and became the precursor to our adsorbents. EFB biochar and coal fly ash has been synthesized to become hydrogel by polymerization process with acrylamide (AAm) as monomer, N,N’-methylene bisacry lamide (MBA) as cross linker and ammonium persulfate (APS) as initiator. In addition, because of the speciality of hydrogel itself, which is has high ability in storing water, the effect of H2O wetness on EFB-HBC and CFA-HC were investigate in adsorption of H2S. EFB-HBC gave a longest breakthrough time and highest adsorption capacity compared with CFA-HC in both condition (dry/wet). The result also indicated that, the increased the bed height, increased the adsorption capacity.

Phytoremediation of selenium by two helophyte species in subsurface flow constructed wetland.

PubMed

Shardendu; Salhani, N; Boulyga, S F; Stengel, E

2003-03-01

The phytoremediation of selenium by two different wetland species was investigated. Selenium (20.4 microg/l) was supplied continuously to subsurface flow constructed wetlands, one vegetated with Typha latifolia L. and the other with Phragmites australis (Cav.) Trin. ex Steud. The beds of both species had same hydraulic loading rate (0.079 m(3)/m(2)/d) and water retention time (24 h). However, the mass loading rate was 1.27 mg Se/m(2)/d for Phragmites and 1.35 mg Se/m(2)/d for Typha. In the Typha bed Se migrated faster than in the Phragmites bed. After 25 d of Se supplementation in the Typha bed about 54% of the Se inlet concentration remained in the outlet water. In the Phragmites bed Se was removed completely from the water after passing through 3/4 of the bed length. After 65 d of Se supplementation the highest amount of Se (2.8 microg/g dry matter) was determined in the organic material of the Typha bed. Roots and rhizomes accumulated 2.2 and 1.8 microg/g dry matter respectively. Phragmites accumulated Se in the leaves and stems, but not in the rhizomes. The accumulation in the leaves (1.8 microg Se/g dry matter) was three times higher than in the stems (0.6 microg Se/g dry matter). Copyright 2002 Elsevier Science Ltd.

Experimental and Analytical Investigation of Pressure Differentials for Clean and Loaded Wire Meshes Used in Zeolite Retention

NASA Technical Reports Server (NTRS)

Knox, James C.

2004-01-01

Following failure of the carbon dioxide removal assembly (CDRA) on the ISS, a CDRA teardown, test, and evaluation (TT&E) effort found that the sorbent material was not retained as intended by the packed beds and that presence of the sorbent in the check valve and selector valve was the cause of the failure of these components. This paper documents the development of design data for an in-line filter element. The purpose of the in-line filter is to provide temporary protection for on-orbit CDRA hardware until the bed retainment system can be redesigned and replaced.

Column study of chromium(VI) adsorption from electroplating industry by coconut coir pith.

PubMed

Suksabye, Parinda; Thiravetyan, Paitip; Nakbanpote, Woranan

2008-12-15

The removal of Cr(VI) from electroplating wastewater by coir pith was investigated in a fixed-bed column. The experiments were conducted to study the effect of important parameters such as bed depth (40-60cm) and flow rate (10-30ml min(-1)). At 0.05 C(t)/C(0), the breakthrough volume increased as flow rate decreased or a bed depth increased due to an increase in empty bed contact time (EBCT). The bed depth service time model (BDST) fit well with the experimental data in the initial region of the breakthrough curve, while the simulation of the whole curve using non-linear regression analysis was effective using the Thomas model. The adsorption capacity estimated from the BDST model was reduced with increasing flow rate, which was 16.40mg cm(-3) or 137.91mg Cr(VI)g(-1) coir pith for the flow rates of 10ml min(-1) and 14.05mg cm(-3) or 118.20mg Cr(VI)g(-1) coir pith for the flow rates of 30ml min(-1). At the highest bed depth (60cm) and the lowest flow rate (10mlmin(-1)), the maximum adsorption reached 201.47mg Cr(VI)g(-1) adsorbent according to the Thomas model. The column was regenerated by eluting chromium using 2M HNO(3) after adsorption studies. The desorption of Cr(III) in each of three cycles was about 67-70%. The desorption of Cr(III) in each cycle did not reach 100% due to the fact that Cr(V) was present through the reduction of Cr(VI), and was still in coir pith, possibly bound to glucose in the cellulose part of coir pith. Therefore, the Cr(V) complex cannot be desorbed in solution. The evidence of Cr(V) signal was observed in coir pith, alpha-cellulose and holocellulose extracted from coir pith using electron spin resonance (ESR).

Exceptional arsenic (III,V) removal performance of highly porous, nanostructured ZrO2 spheres for fixed bed reactors and the full-scale system modeling.

PubMed

Cui, Hang; Su, Yu; Li, Qi; Gao, Shian; Shang, Jian Ku

2013-10-15

Highly porous, nanostructured zirconium oxide spheres were fabricated from ZrO2 nanoparticles with the assistance of agar powder to form spheres with size at millimeter level followed with a heat treatment at 450 °C to remove agar network, which provided a simple, low-cost, and safe process for the synthesis of ZrO2 spheres. These ZrO2 spheres had a dual-pore structure, in which interconnected macropores were beneficial for liquid transport and the mesopores could largely increase their surface area (about 98 m(2)/g) for effective contact with arsenic species in water. These ZrO2 spheres demonstrated an even better arsenic removal performance on both As(III) and As(V) than ZrO2 nanoparticles, and could be readily applied to commonly used fixed-bed adsorption reactors in the industry. A short bed adsorbent test was conducted to validate the calculated external mass transport coefficient and the pore diffusion coefficient. The performance of full-scale fixed bed systems with these ZrO2 spheres as the adsorber was estimated by the validated pore surface diffusion modeling. With the empty bed contact time (EBCT) at 10 min and the initial arsenic concentration at 30 ppb, the number of bed volumes that could be treated by these dry ZrO2 spheres reached ~255,000 BVs and ~271,000 BVs for As(III) and As(V), respectively, until the maximum contaminant level of 10 ppb was reached. These ZrO2 spheres are non-toxic, highly stable, and resistant to acid and alkali, have a high arsenic adsorption capacity, and could be easily adapted for various arsenic removal apparatus. Thus, these ZrO2 spheres may have a promising potential for their application in water treatment practice. Copyright © 2013 Elsevier Ltd. All rights reserved.

Sacral root neuromodulation in idiopathic nonobstructive chronic urinary retention.

PubMed

Shaker, H S; Hassouna, M

1998-05-01

Sacral root neuromodulation is becoming a superior alternative to the standard treatment of idiopathic nonobstructive urinary retention. We report results in 20 successive patients who underwent sacral foramen implantation to restore bladder function. After an initial, thorough baseline assessment 20 patients 19.43 to 55.66 years old with idiopathic nonobstructive urinary retention underwent percutaneous nerve evaluation. Response was assessed by a detailed voiding diary. Responders underwent implantation with an S3 foramen implant, and were followed 1, 3 and 6 months postoperatively, and every 6 months thereafter. Sacral root neuromodulation restored voiding capability in these patients. Bladders were emptied with minimal post-void residual urine, which decreased from 78.3 to 5.5 to 10.2% of the total voided volume from baseline to postoperative followup. These results were reflected in uroflowmetry and pressure-flow studies, which were almost normal after implantation. Furthermore, the urinary tract infection rate decreased significantly and associated pelvic pain improved substantially. The Beck depression inventory and SF-36 quality of life questionnaire indicated some improvement but reached significance in only 1 item. In addition, cystometrography showed no significant difference after 6 months of implantation compared with baseline values. Complications were minimal and within expectations. Sacral root neuromodulation is an appealing, successful modality for nonobstructive urinary retention. Only patients who have a good response to percutaneous nerve evaluation are candidates for implantation. The high efficacy in patients who undergo implantation, relative simplicity of the procedure and low complication rate make this a treatment breakthrough in this difficult group.

Separation of hemicellulose-derived saccharides from wood hydrolysate by lime and ion exchange resin.

PubMed

Wang, Xiaojun; Zhuang, Jingshun; Fu, Yingjuan; Tian, Guoyu; Wang, Zhaojiang; Qin, Menghua

2016-04-01

A combined process of lime treatment and mixed bed ion exchange was proposed to separate hemicellulose-derived saccharides (HDS) from prehydrolysis liquor (PHL) of lignocellulose as value added products. The optimization of lime treatment achieved up to 44.2% removal of non-saccharide organic compounds (NSOC), mainly colloidal substances, with negligible HDS degradation at 0.5% lime level and subsequent neutralization by phosphoric acid. The residual NSOC and calcium ions in lime-treated PHL were eliminated by mixed bed ion exchange. The breakthrough curves of HDS and NSOC showed selective retention toward NSOC, leading to 75% HDS recovery with 95% purity at 17 bed volumes of exchange capacity. In addition, macroporous resin showed higher exchange capacity than gel resin as indicated by the triple processing volume. The remarkable selectivity of the combined process suggested the feasibility for HDS separation from PHL. Copyright © 2016 Elsevier Ltd. All rights reserved.

Treatment of synthetic refinery wastewater in anoxic-aerobic sequential moving bed reactors and sulphur recovery.

PubMed

Mallick, Subrat Kumar; Chakraborty, Saswati

2017-11-10

Objective of the present study was to simultaneously biodegrade synthetic petroleum refinery wastewater containing phenol (750 mg/L), sulphide (750 mg/L), hydrocarbon (as emulsified diesel of 300 mg/L), ammonia-nitrogen (350 mg/L) at pH >9 in anoxic-aerobic sequential moving bed reactors. The optimum mixing speed of anoxic reactor was observed at 20 rpm and beyond that, removal rate remained constant. In anoxic reactor the minimum hydraulic retention time was observed to be 2 days for complete removal of sulphide, 40-50% removal of phenol and total hydrocarbons and 52% of sulphur recovery. The optimum HRT of aerobic moving bed reactor was observed as 16 h (total HRT of 64 h for anoxic and aerobic reactors) for complete removals of phenol, total hydrocarbons, COD (chemical oxygen demand) and ammonia-nitrogen with nitrification.

Continuous nasogastric tube feeding: monitoring by combined use of refractometry and traditional gastric residual volumes.

PubMed

Chang, W-K; McClave, S-A; Chao, Y-C

2004-02-01

Traditional use of gastric residual volumes (GRVs) is insensitive and cannot distinguish retained enteral formula from the large volume of endogenous secretions. We designed this prospective study to determine whether refractometry and Brix value (BV) measurements could be used to monitor gastric emptying and tolerance in patients receiving continuous enteral feeding. Thirty-six patients on continuous nasogastric tube feeding were divided into two groups; patients with lower GRVs (<75 ml) in Group 1, patients with higher GRVs (>75 ml) in Group 2. Upon entry, all gastric contents were aspirated, the volume was recorded (Asp GRV), BV measurements were made by refractometry, and then the contents were reinstilled but diluted with 30 ml additional water. Finally, a small amount was reaspirated and repeat BV measurements were made. Three hours later, the entire procedure was repeated a second time. The BV ratio, calculated (Cal) GRV, and volume of formula remaining were calculated by derived equations. Mean BV ratios were significantly higher for those patients in Group 2 compared to those in Group 1. All but one of the 22 patients (95%) in Group 1 had a volume of formula remaining in the stomach estimated on both measurements to be less than the hourly infusion rate (all these patients had BV ratios <70%). In contrast, six of the 14 patients in Group 2 (43%) on both measurements were estimated to have volumes of formula remaining that were greater than the hourly infusion rate (all these patients had BV ratios >70%). Three of the Group 2 patients (21%) whose initial measurement showed evidence for retention of formula, improved on repeat follow-up measurement assuring adequate gastric emptying. The remaining five patients from Group 2 (35%) had a volume of formula remaining that was less than the hourly infusion rate on both measurements. The pattern of Asp GRVs and serial pre- and post-dilution BVs failed to differentiate these patients in Group 2 with potential emptying problems from those with sufficient gastric emptying. Refractometry and measurement of the BV may improve the clinical utilization of GRVs, by its ability to identify the component of formula within gastric contents and track changes in that component related to gastric emptying.

Fluid flow through a high cell density fluidized-bed during centrifugal bioreactor culture.

PubMed

Detzel, Christopher J; Van Wie, Bernard J; Ivory, Cornelius F

2010-01-01

An increasing demand for products such as tissues, proteins, and antibodies from mammalian cell suspension cultures is driving interest in increasing production through high-cell density bioreactors. The centrifugal bioreactor (CCBR) retains cells by balancing settling forces with surface drag forces due to medium throughput and is capable of maintaining cell densities above 10(8) cells/mL. This article builds on a previous study where the fluid mechanics of an empty CCBR were investigated showing fluid flow is nonuniform and dominated by Coriolis forces, raising concerns about nutrient and cell distribution. In this article, we demonstrate that the previously reported Coriolis forces are still present in the CCBR, but masked by the presence of cells. Experimental dye injection observations during culture of 15 microm hybridoma cells show a continual uniform darkening of the cell bed, indicating the region of the reactor containing cells is well mixed. Simulation results also indicate the cell bed is well mixed during culture of mammalian cells ranging in size from 10 to 20 microm. However, simulations also allow for a slight concentration gradient to be identified and attributed to Coriolis forces. Experimental results show cell density increases from 0.16 to 0.26 when centrifugal force is doubled by increasing RPM from 650 to 920 at a constant inlet velocity of 6.5 cm/s; an effect also observed in the simulation. Results presented in this article indicate cells maintained in the CCBR behave as a high-density fluidized bed of cells providing a homogeneous environment to ensure optimal growth conditions. (c) 2010 American Institute of Chemical Engineers

Fluid Flow through a High Cell Density Fluidized-Bed during Centrifugal Bioreactor Culture

PubMed Central

Detzel, Christopher J.; Van Wie, Bernard J.; Ivory, Cornelius F.

2010-01-01

An increasing demand for products such as tissues, proteins, and antibodies from mammalian cell suspension cultures is driving interest in increasing production through high-cell density bioreactors. The centrifugal bioreactor (CCBR) retains cells by balancing settling forces with surface drag forces due to medium throughput and is capable of maintaining cell densities above 108 cells/mL. This article builds on a previous study where the fluid mechanics of an empty CCBR were investigated showing fluid flow is nonuniform and dominated by Coriolis forces, raising concerns about nutrient and cell distribution. In this article, we demonstrate that the previously reported Coriolis forces are still present in the CCBR, but masked by the presence of cells. Experimental dye injection observations during culture of 15 μm hybridoma cells show a continual uniform darkening of the cell bed, indicating the region of the reactor containing cells is well mixed. Simulation results also indicate the cell bed is well mixed during culture of mammalian cells ranging in size from 10 to 20 μm. However, simulations also allow for a slight concentration gradient to be identified and attributed to Coriolis forces. Experimental results show cell density increases from 0.16 to 0.26 when centrifugal force is doubled by increasing RPM from 650 to 920 at a constant inlet velocity of 6.5 cm/s; an effect also observed in the simulation. Results presented in this article indicate cells maintained in the CCBR behave as a high-density fluidized bed of cells providing a homogeneous environment to ensure optimal growth conditions. PMID:20205172

Sludge sampler

DOEpatents

Ward, Ralph C.

1983-01-01

The disclosure relates to a sludge sampler comprising an elongated generally cylindrical housing containing a baffle containing an aperture. Connected to the aperture is a flexible tubing having a valve for maintaining and releasing pressure in the lower end of the housing and exiting the upper end of the housing. The lower end of the housing contains a ball check valve maintained in closed position by pressure. When the lower end of the device contacts the sludge bed, the pressure valve is opened, enabling sludge to enter the lower end of the housing. After the sample is collected the valve is closed. An upsetting pin opens the valve to empty a sludge sample after the sample is removed from the fluid.

Biofiltration: Fundamentals, design and operations principles and applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Swanson, W.J.; Loehr, R.C.

1997-06-01

Biofiltration is a biological air pollution control technology for volatile organic compounds (VOCs). This paper summarizes the fundamentals, design and operation, and application of the process. Biofiltration has been demonstrated to be an effective technology for VOCs from many industries. Large and full-scale systems are in use in Europe and the US. With proper design and operation, VOC removal efficiencies of 95--99% have been achieved. Important parameters for design and performance are empty-bed contact time, gas surface loading, mass loading, elimination capacity, and removal efficiency. Key design and operation factors include chemical and media properties, moisture, pH, temperature, nutrient availability,more » gas pretreatment, and variations in loading.« less

Effect of saponins on n-hexane removal in biotrickling filters.

PubMed

Tu, Yanhong; Yang, Chunping; Cheng, Yan; Zeng, Guangming; Lu, Li; Wang, Lu

2015-01-01

Saponins was applied to enhance the removal of n-hexane in a biotrickling filter (BTF) in this study. Comparison experiments were carried out to examine the effect of saponins on n-hexane removal in two BTFs at various saponins concentrations, n-hexane loading rates (LRs) and gas empty bed contact times (EBCTs). Results show that the optimum concentration of saponins in nutrient feed was 50.0mgL(-1). When organic LR of n-hexane increased from 47.8 to 120.0gm(-3)h(-1), the removal efficiency (RE) for BTF1 (with saponins) and BTF2 (without saponins) decreased from 91.3% to 83.3% and from 62.8% to 56.8%, respectively. As gas EBCT decreased from 30.0 to 7.5s, the RE declined from 88.4% to 64.5% for BTF1 and from 61.4% to 38.3% for BTF2. Saponins could also decrease the biomass accumulation rate within the medium bed. These results could be referred in the design and operation of BTFs for hydrophobic VOC removal. Copyright © 2014 Elsevier Ltd. All rights reserved.

Chronic urinary retention in men: how we define it, and how does it affect treatment outcome.

PubMed

Negro, Carlo L A; Muir, Gordon H

2012-12-01

What's known on the subject? and What does the study add? Chronic urinary retention (CUR) is a poorly defined entity, as the key element of definition, significant postvoid residual urine volume (PVR), has not a worldwide and moreover evidenced-based definition. There is no agreement on which is the threshold value to define a significant PVR and different society produced guidelines with different thresholds ranging from 300 mL to 1000 mL. Diagnosis is difficult, and management has not been defined yet. There is a lack of studies on the best management of these patients, as this group of patients has always been considered at high risk of failure. Only one study compares conservative with the surgical management but it is not a randomised controlled trail. This review offers a systematic appraisal of the most recent publications on CUR. It indicates the absence of a real worldwide agreed definition, as the two keys element of it are not satisfactorily defined yet: significant PVR, is suffering from a lack of evidenced-based definition, and percussable or palpable bladder is a very nebulous concept as it is not a criteria of certainty as different individual variables affect it. This has an important effect on management which is not structured. Most of the trials involving benign prostatic hyperplasia treatments (either medical or surgical) tend to exclude this group of patients, which is a clinically important group, comprising up to a quarter of men undergoing TURP in the UK. Urinary retention describes a bladder that does not empty completely or does not empty at all. Historically, urinary retention has been classified as either acute or chronic the latter is generally classified as high pressure or low pressure according to the bladder filling pressure on urodynamic. A MEDLINE® search for articles written in English and published before January 2010 was done using a list of terms related to urinary retention: 'urinary retention', 'chronic urinary retention' and 'PVR'. Chronic urinary retention (CUR) is defined by the International Continence Society as 'a non-painful bladder, which remains palpable or percussable after the patient has passed urine'. Abrams was the first to choose a residual urine volume >300 mL to define CUR as he considered it the minimum volume at which the bladder becomes palpable suprapubically. The UK National Institute for Health and Clinical Excellence lower urinary tract symptoms (LUTS) guidelines define CUR as a postvoid residual urine volume (PVR) of >1000 mL. No studies have specifically addressed the problem of quantifying the minimum amount of urine present in the bladder to define CUR. Nor did we find any publications objectively assessing at what amount of urine a bladder can be palpable. The ability to feel a bladder may rely on variables (i.e. medical skills and patient habitus). There is a marked variability of PVR, so the test should be repeated to improve precision. As defining CUR is difficult, structured management is challenging. Nearly all prospective trials exclude men with CUR from analysis, possibly anticipating a poor outcome and a high risk of complications. However, men with CUR are a clinically important group, comprising up to 25% of men undergoing transurethral resection of the prostate. Definition of CUR is imprecise and arbitrary. Most studies seem to describe the condition as either a PVR of >300 mL in men who are voiding, or >1000 mL in men who are unable to void. This confusion leads to an inability to design and interpret studies; indeed most prospective trials simply exclude these patients. There is a clear need for internationally accepted definitions of retention to allow both treatment and reporting of outcomes in men with LUTS, and for such definitions to be used by all investigators in future trials. © 2012 BJU INTERNATIONAL.

Retention and transport of nutrients in a third-order stream in northwestern California; hyporheic processes

USGS Publications Warehouse

Triska, F.J.; Kennedy, V.C.; Avanzino, R.J.; Zellweger, G.W.; Bencala, K.E.

1989-01-01

Chloride and nitrate were coinjected into the surface waters of a third-order stream for 20 d to exmaine solute retention, and the fate of nitrate during subsurface transport. A series of wells (shallow pits) 0.5-10 m from the adjacent channel were sampled to estimate the lateral interflow of water. Two subsurface return flows beneath the wetted channel were also examined. Results indicated that the capacity of the hyporheic zone for transient solute storage and as potential biological habitat varies with channel morphology, bed roughness, and permeability. A conceptual model that considers the groundwater-stream water interface as the fluvial boundary is proposed. -from Authors

Pharmaceutical removal in tropical subsurface flow constructed wetlands at varying hydraulic loading rates.

PubMed

Zhang, Dong Qing; Gersberg, Richard M; Hua, Tao; Zhu, Junfei; Tuan, Nguyen Anh; Tan, Soon Keat

2012-04-01

Determining the fate of emerging organic contaminants in an aquatic ecosystem is important for developing constructed wetlands (CWs) treatment technology. Experiments were carried out in subsurface flow CWs in Singapore to evaluate the fate and transport of eight pharmaceutical compounds. The CW system included three parallel horizontal subsurface flow CWs and three parallel unplanted beds fed continuously with synthetic wastewater at different hydraulic retention times (HRTs). The findings of the tests at 2-6 d HRTs showed that the pharmaceuticals could be categorized as (i) efficiently removed compounds with removal higher than 85% (ketoprofen and salicylic acid); (ii) moderately removed compounds with removal efficiencies between 50% and 85% (naproxen, ibuprofen and caffeine); and (iii) poorly removed compounds with efficiency rate lower than 50% (carbamazepine, diclofenac, and clofibric acid). Except for carbamazepine and salicylic acid, removal efficiencies of the selected pharmaceuticals showed significant (p<0.05) enhancement in planted beds as compared to the unplanted beds. Removal of caffeine, ketoprofen and clofibric acid were found to follow first order decay kinetics with decay constants higher in the planted beds than the unplanted beds. Correlations between pharmaceutical removal efficiencies and log K(ow) were not significant (p>0.05), implying that their removal is not well related to the compound's hydrophobicity. Copyright © 2011 Elsevier Ltd. All rights reserved.

Comparison on pore development of activated carbon produced by chemical and physical activation from palm empty fruit bunch

NASA Astrophysics Data System (ADS)

Hidayat, A.; Sutrisno, B.

2016-11-01

It is well-known that activated carbon is considered to be the general adsorbent due to the large range of applications. Numerous works are being continuously published concerning its use as adsorbent for: treatment of potable water; purification of air; retention of toxins by respirators; removal of organic and inorganic pollutants from flue gases and industrial waste gases and water; recuperation of solvents and hydrocarbons volatilized from petroleum derivatives; catalysis; separation of gas mixtures (molecularsieve activated carbons); storage of natural gas and hydrogen; energy storage in supercapacitors; recovery of gold, silver and othernoble metals; etc. This work presents producing activated carbons from palm empty fruit bunch using both physical activation with CO2 and chemical activation with KOH. The resultant activated carbons were characterized by measuring their porosities and pore size distributions. A comparison of the textural characteristics and surface chemistry of the activated carbon from palm empty fruit bunch by the CO2 and the KOH activation leads to the following findings: An activated carbon by the CO2 activation under the optimum conditions has a BET surface area of 717 m2/g, while that by the KOH activation has a BET surface area of 613 m2/g. The CO2 activation generated a highly microporous carbon (92%) with a Type-I isotherm, while the KOH activation generated a mesoporous one (70%) with a type-IV isotherm, the pore volumes are 0.2135 and 0.7426 cm3.g-1 respectively. The average pore size of the activated carbons is 2.72 and 2.56 nm for KOH activation and CO2 activation, respectively. The FT-IR spectra indicated significant variation in the surface functional groups are quite different for the KOH activated and CO2 activated carbons.

Relating gastric scintigraphy and symptoms to motility capsule transit and pressure findings in suspected gastroparesis

PubMed Central

Hasler, W. L.; May, K. P.; Wilson, L. A.; Van Natta, M.; Parkman, H. P.; Pasricha, P. J.; Koch, K. L.; Abell, T. L.; McCallum, R. W.; Nguyen, L. A.; Snape, W. J.; Sarosiek, I.; Clarke, J. O.; Farrugia, G.; Calles-Escandon, J.; Grover, M.; Tonascia, J.; Lee, L. A.; Miriel, L.; Hamilton, F. A.

2018-01-01

Background Wireless motility capsule (WMC) findings are incompletely defined in suspected gastroparesis. We aimed to characterize regional WMC transit and contractility in relation to scintigraphy, etiology, and symptoms in patients undergoing gastric emptying testing. Methods A total of 209 patients with gastroparesis symptoms at NIDDK Gastroparesis Consortium centers underwent gastric scintigraphy and WMCs on separate days to measure regional transit and contractility. Validated questionnaires quantified symptoms. Key Results Solid scintigraphy and liquid scintigraphy were delayed in 68.8% and 34.8% of patients; WMC gastric emptying times (GET) were delayed in 40.3% and showed 52.8% agreement with scintigraphy; 15.5% and 33.5% had delayed small bowel (SBTT) and colon transit (CTT) times. Transit was delayed in ≥2 regions in 23.3%. Rapid transit was rarely observed. Diabetics had slower GET but more rapid SBTT versus idiopathics (P ≤ .02). GET delays related to greater scintigraphic retention, slower SBTT, and fewer gastric contractions (P ≤ .04). Overall gastroparesis symptoms and nausea/vomiting, early satiety/fullness, bloating/distention, and upper abdominal pain subscores showed no relation to WMC transit. Upper and lower abdominal pain scores (P ≤ .03) were greater with increased colon contractions. Constipation correlated with slower CTT and higher colon contractions (P = .03). Diarrhea scores were higher with delayed SBTT and CTT (P ≤ .04). Conclusions & Inferences Wireless motility capsules define gastric emptying delays similar but not identical to scintigraphy that are more severe in diabetics and relate to reduced gastric contractility. Extragastric transit delays occur in >40% with suspected gastroparesis. Gastroparesis symptoms show little association with WMC profiles, although lower symptoms relate to small bowel or colon abnormalities. PMID:28872760

Liposomalization of oxaliplatin induces skin accumulation of it, but negligible skin toxicity.

PubMed

Nishida, Kentaro; Kashiwagi, Misaki; Shiba, Shunsuke; Muroki, Kiwamu; Ohishi, Akihiro; Doi, Yusuke; Ando, Hidenori; Ishida, Tatsuhiro; Nagasawa, Kazuki

2017-12-15

Liposomalization causes alteration of the pharmacokinetics of encapsulated drugs, and allows delivery to tumor tissues through passive targeting via an enhanced permeation and retention (EPR) effect. PEGylated liposomal doxorubicin (Doxil ® , Lipo-DXR), a representative liposomal drug, is well-known to reduce cardiotoxicity and increase the anti-tumor activity of DXR, but to induce the hand-foot syndrome (HFS) as a result of skin DXR accumulation, which is one of its severe adverse effects. We have developed a new liposomal preparation of oxaliplatin (l-OHP), an important anti-tumor drug for treatment of colorectal cancer, using PEGylated liposomes (Lipo-l-OHP), and showed that Lipo-l-OHP exhibits increased anti-tumor activity in tumor-bearing mice compared to the original preparation of l-OHP. However, whether Lipo-l-OHP causes HFS-like skin toxicity similar to Lipo-DXR remains to be determined. Administration of Lipo-l-OHP promoted accumulation of platinum in rat hind paws, however, it caused negligible morphological and histological alterations on the plantar surface of the paws. Administration of DiI-labeled empty PEGylated liposomes gave almost the same distribution profile of dyes into the dermis of hind paws with DXR as in the case of Lipo-DXR. Treatment with Lipo-l-OHP, Lipo-DXR, DiI-labeled empty PEGylated liposomes or empty PEGylated liposomes caused migration of CD68 + macrophages into the dermis of hind paws. These findings suggest that the skin toxicity on administration of liposomalized drugs is reflected in the proinflammatory characteristics of encapsulated drugs, and indicate that Lipo-l-OHP with a higher anti-cancer effect and no HFS may be an outstanding l-OHP preparation leading to an improved quality of life of cancer patients. Copyright © 2017 Elsevier Inc. All rights reserved.

Activation of the cholinergic anti-inflammatory pathway ameliorates postoperative ileus in mice.

PubMed

The, Frans O; Boeckxstaens, Guy E; Snoek, Susanne A; Cash, Jenna L; Bennink, Roel; Larosa, Gregory J; van den Wijngaard, Rene M; Greaves, David R; de Jonge, Wouter J

2007-10-01

We previously showed that intestinal inflammation is reduced by electrical stimulation of the efferent vagus nerve, which prevents postoperative ileus in mice. We propose that this cholinergic anti-inflammatory pathway is mediated via alpha7 nicotinic acetylcholine receptors expressed on macrophages. The aim of this study was to evaluate pharmacologic activation of the cholinergic anti-inflammatory pathway in a mouse model for postoperative ileus using the alpha7 nicotinic acetylcholine receptor-agonist AR-R17779. Mice were pretreated with vehicle, nicotine, or AR-R17779 20 minutes before a laparotomy (L) or intestinal manipulation (IM). Twenty-four hours thereafter gastric emptying was determined using scintigraphy and intestinal muscle inflammation was quantified. Nuclear factor-kappaB transcriptional activity and cytokine production was assayed in peritoneal macrophages. Twenty-four hours after surgery IM led to a delayed gastric emptying compared with L (gastric retention: L(saline) 14% +/- 4% vs IM(saline) 38% +/- 10%, P = .04). Pretreatment with AR-R17779 prevented delayed gastric emptying (IM(AR-R17779) 15% +/- 4%, P = .03). IM elicited inflammatory cell recruitment (L(saline) 50 +/- 8 vs IM(saline) 434 +/- 71 cells/mm(2), P = .001) which was reduced by AR-R17779 pretreatment (IM(AR-R17779) 231 +/- 32 cells/mm(2), P = .04). An equimolar dose of nicotine was not tolerated. Subdiaphragmal vagotomy did not affect the anti-inflammatory properties of AR-R17779. In peritoneal macrophages, both nicotinic agonists reduced nuclear factor kappaB transcriptional activity and proinflammatory cytokine production, with nicotine being more effective than AR-R17779. AR-R17779 treatment potently prevents postoperative ileus, whereas toxicity limits nicotine administration to ineffective doses. Our data further imply that nicotinic inhibition of macrophage activation may involve other receptors in addition to alpha7 nicotinic acetylcholine receptor.

Deep Sludge Gas Release Event Analytical Evaluation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sams, Terry L.

2013-08-15

Long Abstract. Full Text. The purpose of the Deep Sludge Gas Release Event Analytical Evaluation (DSGRE-AE) is to evaluate the postulated hypothesis that a hydrogen GRE may occur in Hanford tanks containing waste sludges at levels greater than previously experienced. There is a need to understand gas retention and release hazards in sludge beds which are 200 -300 inches deep. These sludge beds are deeper than historical Hanford sludge waste beds, and are created when waste is retrieved from older single-shell tanks (SST) and transferred to newer double-shell tanks (DST).Retrieval of waste from SSTs reduces the risk to the environmentmore » from leakage or potential leakage of waste into the ground from these tanks. However, the possibility of an energetic event (flammable gas accident) in the retrieval receiver DST is worse than slow leakage. Lines of inquiry, therefore, are (1) can sludge waste be stored safely in deep beds; (2) can gas release events (GRE) be prevented by periodically degassing the sludge (e.g., mixer pump); or (3) does the retrieval strategy need to be altered to limit sludge bed height by retrieving into additional DSTs? The scope of this effort is to provide expert advice on whether or not to move forward with the generation of deep beds of sludge through retrieval of C-Farm tanks. Evaluation of possible mitigation methods (e.g., using mixer pumps to release gas, retrieving into an additional DST) are being evaluated by a second team and are not discussed in this report. While available data and engineering judgment indicate that increased gas retention (retained gas fraction) in DST sludge at depths resulting from the completion of SST 241-C Tank Farm retrievals is not expected and, even if gas releases were to occur, they would be small and local, a positive USQ was declared (Occurrence Report EM-RP--WRPS-TANKFARM-2012-0014, "Potential Exists for a Large Spontaneous Gas Release Event in Deep Settled Waste Sludge"). The purpose of this technical report is to (1) present and discuss current understandings of gas retention and release mechanisms for deep sludge in U.S. Department of Energy (DOE) complex waste storage tanks; and (2) to identify viable methods/criteria for demonstrating safety relative to deep sludge gas release events (DSGRE) in the near term to support the Hanford C-Farm retrieval mission. A secondary purpose is to identify viable methods/criteria for demonstrating safety relative to DSGREs in the longer term to support the mission to retrieve waste from the Hanford Tank Farms and deliver it to the Waste Treatment and Immobilization Plant (WTP). The potential DSGRE issue resulted in the declaration of a positive Unreviewed Safety Question (USQ). C-Farm retrievals are currently proceeding under a Justification for Continued Operation (JCO) that only allows tanks 241-AN-101 and 241-AN-106 sludge levels of 192 inches and 195 inches, respectively. C-Farm retrievals need deeper sludge levels (approximately 310 inches in 241-AN-101 and approximately 250 inches in 241-AN-106). This effort is to provide analytical data and justification to continue retrievals in a safe and efficient manner.« less

Surficial geology and distribution of post-impoundment sediment of the western part of Lake Mead based on a sidescan sonar and high-resolution seismic-reflection survey

USGS Publications Warehouse

Twichell, David C.; Cross, VeeAnn A.; Rudin, Mark J.; Parolski, Kenneth F.

1999-01-01

Sidescan sonar imagery and high-resolution seismic-reflection profiles were collected in Las Vegas Bay and Boulder Basin of Lake Mead to determine the surficial geology as well as the distribution and thickness of sediment that has accumulated in these areas of the lake since the completion of Hoover Dam in 1935 (Gould, 1951). Results indicate that the accumulation of post-impoundment sediment is restricted to the original Colorado River bed which runs down the axis of Boulder Basin from Boulder Canyon to Hoover Dam, and the old Las Vegas Creek bed that bisects Las Vegas Bay. The sediment cover along the original Colorado River bed is continuous and is typically greater than 10-m thick throughout much of its length with the thickness in some areas exceeding 35 meters. The flat-lying nature of the deposits suggests that they are the result of turbidity currents that flow the length of the lake. The sediment cover in Las Vegas Bay is much thinner (rarely exceeding 2 m in thickness) and more discontinuous. The source for these sediments presumably is Las Vegas Wash and a series of other ephemeral washes that empty into this part of the lake. The presence of sediments along the entire length of the Las Vegas Creek bed suggests that turbidity currents probably are active here as well, and that sediment has been transported from these streams at least 10 km down the axis of this valley to where it enters Boulder Basin. Alluvial deposits and rock outcrops are still exposed on large parts of the lake floor.

Human skeletal muscle protein breakdown during spaceflight

NASA Technical Reports Server (NTRS)

Stein, T. P.; Schluter, M. D.

1997-01-01

Human spaceflight is associated with a loss of body protein. Excretion of 3-methylhistidine (3-MH) in the urine is a useful measurement of myofibrillar protein breakdown. Bed rest, particularly with 6 degrees head-down tilt, is an accepted ground-based model for human spaceflight. The objectives of this report were to compare 3-MH excretion from two Life Sciences shuttle missions (duration 9.5 and 15 days, n = 9) and from 17 days of bed rest (n = 7) with 6 degrees head-down tilt. The bed rest study was designed to mimic an actual Life Sciences spaceflight and so incorporated an extensive battery of physiological tests focused on the musculoskeletal system. Results showed that nitrogen retention, based on excretion of nitrogen in the urine, was reduced during both bed rest [from 22 +/- 1 to 1 +/- 5 mg N x kg(-1) x day(-1) (n = 7; P < 0.05)] and spaceflight [from 57 +/- 9 to 19 +/- 3 mg N x kg(-1) x day(-1) (n = 9; P < 0.05)]. 3-MH excretion was unchanged with either bed rest [pre-bed rest 5.30 +/- 0.29 vs. bed rest 5.71 +/- 0.30 micromol 3-MH x kg(-1) x day(-1), n = 7; P = not significant (NS)] or spaceflight [preflight 4.98 +/- 0.37 vs. 4.59 +/- 0.39 micromol 3-MH x kg(-1) x day(-1) in-flight, n = 9; P = NS]. We conclude that 1) 3-MH excretion was unaffected by spaceflight on the shuttle or with bed rest plus exercise, and 2) because protein breakdown (elevated 3-MH) was increased on Skylab but not on the shuttle, it follows that muscle protein breakdown is not an inevitable consequence of spaceflight.

Cardiovascular consequences of bed rest: effect on maximal oxygen uptake

NASA Technical Reports Server (NTRS)

Convertino, V. A.

1997-01-01

Maximal oxygen uptake (VO2max) is reduced in healthy individuals confined to bed rest, suggesting it is independent of any disease state. The magnitude of reduction in VO2max is dependent on duration of bed rest and the initial level of aerobic fitness (VO2max), but it appears to be independent of age or gender. Bed rest induces an elevated maximal heart rate which, in turn, is associated with decreased cardiac vagal tone, increased sympathetic catecholamine secretion, and greater cardiac beta-receptor sensitivity. Despite the elevation in heart rate, VO2max is reduced primarily from decreased maximal stroke volume and cardiac output. An elevated ejection fraction during exercise following bed rest suggests that the lower stroke volume is not caused by ventricular dysfunction but is primarily the result of decreased venous return associated with lower circulating blood volume, reduced central venous pressure, and higher venous compliance in the lower extremities. VO2max, stroke volume, and cardiac output are further compromised by exercise in the upright posture. The contribution of hypovolemia to reduced cardiac output during exercise following bed rest is supported by the close relationship between the relative magnitude (% delta) and time course of change in blood volume and VO2max during bed rest, and also by the fact that retention of plasma volume is associated with maintenance of VO2max after bed rest. Arteriovenous oxygen difference during maximal exercise is not altered by bed rest, suggesting that peripheral mechanisms may not contribute significantly to the decreased VO2max. However reduction in baseline and maximal muscle blood flow, red blood cell volume, and capillarization in working muscles represent peripheral mechanisms that may contribute to limited oxygen delivery and, subsequently, lowered VO2max. Thus, alterations in cardiac and vascular functions induced by prolonged confinement to bed rest contribute to diminution of maximal oxygen uptake and reserve capacity to perform physical work.

Control of methanol vapours in a biotrickling filter: performance analysis and experimental determination of partition coefficient.

PubMed

Avalos Ramirez, Antonio; Peter Jones, J; Heitz, Michéle

2009-02-01

Methanol vapours were treated in a biotrickling filter (BTF) packed with inert polypropylene spheres. The effects of the nitrogen concentration in the nutrient solution, the empty bed residence time (EBRT) and the methanol inlet concentration, on the BTF performance, were all examined. The elimination capacity (EC), the biomass and the carbon dioxide production rates were all increased with the rising of the nitrogen concentration and the EBRT. The EC also rose with increasing methanol inlet load (IL) when the methanol inlet concentration and the EBRT were varied, from 0.3 to 37.0 g m(-3), and from 20 to 65 s, respectively. The BTF reached its maximum EC level of 2160 g m(-3) h(-1) when it was operated at an IL level of 3700 g m(-3) h(-1). The input methanol was removed through two mechanisms: biodegradation and absorption in the liquid phase. The partition coefficient for the methanol in the BTF was determined at five EBRTs and along the packed bed. It generally followed the Henry model, having an average value of 2.64 x 10(-4)[mol L(-1)](gas)/[mol L(-1)](liquid).

Remediation of Organic and Inorganic Arsenic Contaminated Groundwater using a Nonocrystalline TiO2 Based Adsorbent

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jing, C.; Meng, X; Calvache, E

2009-01-01

A nanocrystalline TiO2-based adsorbent was evaluated for the simultaneous removal of As(V), As(III), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA) in contaminated groundwater. Batch experimental results show that As adsorption followed pseudo-second order rate kinetics. The competitive adsorption was described with the charge distribution multi-site surface complexation model (CD-MUSIC). The groundwater containing an average of 329 ?g L-1 As(III), 246 ?g L-1 As(V), 151 ?g L-1 MMA, and 202 ?g L-1 DMA was continuously passed through a TiO2 filter at an empty bed contact time of 6 min for 4 months. Approximately 11 000, 14 000, and 9900 bed volumesmore » of water had been treated before the As(III), As(V), and MMA concentration in the effluent increased to 10 ?g L-1. However, very little DMA was removed. The EXAFS results demonstrate the existence of a bidentate binuclear As(V) surface complex on spent adsorbent, indicating the oxidation of adsorbed As(III). A nanocrystalline TiO2-based adsorbent could be used for the simultaneous removal of As(V), As(III), MMA, and DMA in contaminated groundwater.« less

Super enhanced permeability and retention (SUPR) effects in tumors following near infrared photoimmunotherapy

NASA Astrophysics Data System (ADS)

Kobayashi, Hisataka; Choyke, Peter L.

2016-06-01

To date, the delivery of nano-sized therapeutic agents to cancers largely relies on enhanced permeability and retention (EPR) effects that are caused by the leaky nature of cancer vasculature. However, nano-sized agents delivered in this way have demonstrated limited success in oncology due to the relatively small magnitude of the EPR effect. For achieving superior delivery of nano-sized agents, super-enhanced permeability and retention (SUPR) effects are needed. Near infrared photo-immunotherapy (NIR-PIT) is a recently reported therapy that treats tumors with light therapy and subsequently causes an increase in nano-drug delivery up to 24-fold compared with untreated tumors in which only the EPR effect is present. SUPR effects could enhance delivery into tumor beds of a wide variety of nano-sized agents including particles, antibodies, and protein binding small molecular agents. Therefore, taking advantage of the SUPR effects after NIR-PIT may be a promising avenue to utilize a wide variety of nano-drugs in a highly effective manner.

Mixed-culture H2 fermentation performance and the relation between microbial community composition and hydraulic retention times for a fixed bed reactor fed with galactose/glucose mixtures.

PubMed

Anburajan, Parthiban; Park, Jong-Hun; Sivagurunathan, Periyasamy; Pugazhendhi, Arivalagan; Kumar, Gopalakrishnan; Choi, Chang-Su; Kim, Sang-Hyoun

2017-09-01

This study examined the mesophilic continuous biohydrogen fermentation from galactose and glucose mixture with an initial substrate concentration of 15 g/L (galactose 12 g/L and glucose 3 g/L) as a resembling carbon source of pretreated red algal hydrolyzate. A fixed bed reactor was fed with the sugar mixture at various hydraulic retention times (HRTs) ranging 12 to 1.5 h. The maximum hydrogen production rate of 52.6 L/L-d was found at 2 h HRT, while the maximum hydrogen yield of 2.3±0.1 mol/mol hexose added, was achieved at 3 h HRT. Microbial communities and species distribution were analyzed via quantitative polymerase chain reaction (qPCR) and the dominant bacterial population was found as Clostridia followed by Lactobacillus sp. Packing material retained higher 16S rRNA gene copy numbers of total bacteria and Clostridium butyricum fraction compared to fermentation liquor. The finding of the study has demonstrated that H 2 production from galactose and glucose mixture could be a viable approach for hydrogen production. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Dynamics of Archaeal and Bacterial Communities in Response to Variations of Hydraulic Retention Time in an Integrated Anaerobic Fluidized-Bed Membrane Bioreactor Treating Benzothiazole Wastewater

PubMed Central

Li, Yue; Hu, Qi

2018-01-01

An integrated anaerobic fluidized-bed membrane bioreactor (IAFMBR) was investigated to treat synthetic high-strength benzothiazole wastewater (50 mg/L) at a hydraulic retention time (HRT) of 24, 18, and 12 h. The chemical oxygen demand (COD) removal efficiency (from 93.6% to 90.9%), the methane percentage (from 70.9% to 69.27%), and the methane yield (from 0.309 m3 CH4/kg·CODremoved to 0.316 m3 CH4/kg·CODremoved) were not affected by decreasing HRTs. However, it had an adverse effect on membrane fouling (decreasing service period from 5.3 d to 3.2 d) and benzothiazole removal efficiency (reducing it from 97.5% to 82.3%). Three sludge samples that were collected on day 185, day 240, and day 297 were analyzed using an Illumina® MiSeq platform. It is striking that the dominant genus of archaea was always Methanosaeta despite of HRTs. The proportions of Methanosaeta were 80.6% (HRT 24), 91.9% (HRT 18), and 91.2% (HRT 12). The dominant bacterial genera were Clostridium in proportions of 23.9% (HRT 24), 16.4% (HRT 18), and 15.3% (HRT 12), respectively. PMID:29853797

Increased Water Storage at Ice-stream Onsets: A Critical Mechanism?

NASA Technical Reports Server (NTRS)

Bindschadler, Robert; Choi, Hyeungu

2007-01-01

The interdependence of rapid ice flow, surface topography and the spatial distribution of subglacial water are examined by linking existing theories. The motivation is to investigate whether the acceleration of an ice-stream tributary contains a positive feedback that encourages the retention of subglacial water that leads to faster flow. Periodically varying surface and bed topographies are related through a linear ice-flow perturbation theory for various values of mean surface slope, perturbation amplitude and basal sliding speeds. The topographic variations lead to a periodic variation in hydraulic potential that is used to infer the tendency for subglacial water to be retained in local hydraulic potential minima. If water retention leads to enhanced basal sliding, a positive feedback loop is closed that could explain the transition from slower tributary flow to faster-streaming flow and the sustained downstream acceleration along the tributary-ice-stream system. A sensitivity study illustrates that the same range of topographic wavelengths most effectively transmitted from the bed to the surface also strongly influences the behavior of subglacial water. A lubrication index is defined to qualitatively measure the heterogeneity of the subglacial hydrologic system. Application of this index to field data shows that the transition from tributary to ice stream closely agrees with the location where subglacial water may be first stored.

Seasonal nutrient dynamics in a chalk stream: the River Frome, Dorset, UK.

PubMed

Bowes, M J; Leach, D V; House, W A

2005-01-05

Chalk streams provide unique, environmentally important habitats, but are particularly susceptible to human activities, such as water abstraction, fish farming and intensive agricultural activity on their fertile flood-meadows, resulting in increased nutrient concentrations. Weekly phosphorus, nitrate, dissolved silicon, chloride and flow measurements were made at nine sites along a 32 km stretch of the River Frome and its tributaries, over a 15 month period. The stretch was divided into two sections (termed the middle and lower reach) and mass balances were calculated for each determinand by totalling the inputs from upstream, tributaries, sewage treatment works and an estimate of groundwater input, and subtracting this from the load exported from each reach. Phosphorus and nitrate were retained within the river channel during the summer months, due to bioaccumulation into river biota and adsorption of phosphorus to bed sediments. During the autumn to spring periods, there was a net export, attributed to increased diffuse inputs from the catchment during storms, decomposition of channel biomass and remobilisation of phosphorus from the bed sediment. This seasonality of retention and remobilisation was higher in the lower reach than the middle reach, which was attributed to downstream changes in land use and fine sediment availability. Silicon showed much less seasonality, but did have periods of rapid retention in spring, due to diatom uptake within the river channel, and a subsequent release from the bed sediments during storm events. Chloride did not produce a seasonal pattern, indicating that the observed phosphorus and nitrate seasonality was a product of annual variation in diffuse inputs and internal riverine processes, rather than an artefact of sampling, flow gauging and analytical errors.

Chemohypersensitivity and autonomic modulation of venous capacitance in the pathophysiology of acute decompensated heart failure.

PubMed

Burchell, Amy E; Sobotka, Paul A; Hart, Emma C; Nightingale, Angus K; Dunlap, Mark E

2013-06-01

Heart failure is increasing in prevalence around the world, with hospitalization and re-hospitalization as a result of acute decompensated heart failure (ADHF) presenting a huge social and economic burden. The mechanism for this decompensation is not clear. Whilst in some cases it is due to volume expansion, over half of patients with an acute admission for ADHF did not experience an increase in total body weight. This calls into question the current treatment strategy of targeting salt and water retention in ADHF. An alternative hypothesis proposed by Fallick et al. is that an endogenous fluid shift from the splanchnic bed is implicated in ADHF, rather than an exogenous fluid gain. The hypothesis states further that this shift is triggered by an increase in sympathetic tone causing vasoconstriction in the splanchnic bed, a mechanism that can translocate blood rapidly into the effective circulating volume, generating the raised venous pressure and congestion seen in ADHF. This hypothesis encourages a new clinical paradigm which focuses on the underlying mechanisms of congestion, and highlights the importance of fluid redistribution and neurohormonal activation in its pathophysiology. In this article, we consider the concept that ADHF is attributable to episodic sympathetic hyperactivity, resulting in fluid shifts from the splanchnic bed. Chemosensitivity is a pathologic autonomic mechanism associated with mortality in patients with systolic heart failure. Tonic and episodic activity of the peripheral chemoreceptors may underlie the syndrome of acute decompensation without total body salt and water expansion. We suggest in this manuscript that chemosensitivity in response to intermittent hypoxia, such as experienced in sleep disordered breathing, may explain the intermittent sympathetic hyperactivity underlying renal sodium retention and acute volume redistribution from venous storage sites. This hypothesis provides an alternative structure to guide novel diagnostic and treatment strategies for ADHF.

Retention of elemental mercury in fly ashes in different atmospheres

DOE Office of Scientific and Technical Information (OSTI.GOV)

M.A. Lopez-Anton; M. Diaz-Somoano; M.R. Martinez-Tarazona

2007-01-15

Mercury is an extremely volatile element, which is emitted from coal combustion to the environment mostly in the vapor phase. To avoid the environmental problems that the toxic species of this element may cause, control technologies for the removal of mercury are necessary. Recent research has shown that certain fly ash materials have an affinity for mercury. Moreover, it has been observed that fly ashes may catalyze the oxidation of elemental mercury and facilitate its capture. However, the exact nature of Hg-fly ash interactions is still unknown, and mercury oxidation through fly ash needs to be investigated more thoroughly. Inmore » this work, the influence of a gas atmosphere on the retention of elemental mercury on fly ashes of different characteristics was evaluated. The retention capacity was estimated comparatively in inert and two gas atmospheres containing species present in coal gasification and coal combustion. Fly ashes produced in two pulverized coal combustion (PCC) plants, produced from coals of different rank (CTA and CTSR), and a fly ash (CTP) produced in a fluidized bed combustion (FBC) plant were used as raw materials. The mercury retention capacity of these fly ashes was compared to the retention obtained in different activated carbons. Although the capture of mercury is very similar in the gasification atmosphere and N{sub 2}, it is much more efficient in a coal combustion retention, being greater in fly ashes from PCC than those from FBC plants. 22 refs., 6 figs., 3 tabs.« less

Assessing the effect, on animal model, of mixture of food additives, on the water balance.

PubMed

Friedrich, Mariola; Kuchlewska, Magdalena

2013-01-01

The purpose of this study was to determine, on the animal model, the effect of modification of diet composition and administration of selected food additives on water balance in the body. The study was conducted with 48 males and 48 females (separately for each sex) of Wistar strain rats divided into four groups. For drinking, the animals from groups I and III were receiving water, whereas the animals from groups II and IV were administered 5 ml of a solution of selected food additives (potassium nitrate - E 252, sodium nitrite - E 250, benzoic acid - E 210, sorbic acid - E 200, and monosodium glutamate - E 621). Doses of the administered food additives were computed taking into account the average intake by men, expressed per body mass unit. Having drunk the solution, the animals were provided water for drinking. The mixture of selected food additives applied in the experiment was found to facilitate water retention in the body both in the case of both male and female rats, and differences observed between the volume of ingested fluids and the volume of excreted urine were statistically significant in the animals fed the basal diet. The type of feed mixture provided to the animals affected the site of water retention - in the case of animals receiving the basal diet analyses demonstrated a significant increase in water content in the liver tissue, whereas in the animals fed the modified diet water was observed to accumulate in the vascular bed. Taking into account the fact of water retention in the vascular bed, the effects of food additives intake may be more adverse in the case of females.

Coalbed methane resources of the Appalachian Basin, eastern USA

USGS Publications Warehouse

Milici, Robert C.; Hatch, Joseph R.; Pawlewicz, Mark J.

2010-01-01

In 2002, the U.S. Geological Survey (USGS) assessed the technically recoverable, undiscovered coalbed-gas resources in the Appalachian basin and Black Warrior basin Assessment Provinces as about 15.5 trillion cubic feet. Although these resources are almost equally divided between the two areas, most of the production occurs within relatively small areas within these Provinces, where local geological and geochemical attributes have resulted in the generation and retention of large amounts of methane within the coal beds and have enhanced the producibility of the gas from the coal. In the Appalachian basin, coalbed methane (CBM) tests are commonly commercial where the cumulative coal thickness completed in wells is greater than three meters (10 ft), the depth of burial of the coal beds is greater than 100 m (350 ft), and the coal is in the thermogenic gas window. In addition to the ubiquitous cleating within the coal beds, commercial production may be enhanced by secondary fracture porosity related to supplemental fracture systems within the coal beds. In order to release the methane from microporus coal matrix, most wells are dewatered prior to commercial production of gas. Two Total Petroleum Systems (TPS) were defined by the USGS during the assessment: the Pottsville Coal-bed gas TPS in Alabama, and the Carboniferous Coal-bed Gas TPS in Pennsylvania, Ohio, West Virginia, eastern Kentucky, Virginia, Tennessee, and Alabama. These were divided into seven assessment units, of which three had sufficient data to be assessed. Production rates are higher in most horizontal wells drilled into relatively thick coal beds, than in vertical wells; recovery per unit area is greater, and potential adverse environmental impact is decreased.

Stellar Wind Retention and Expulsion in Massive Star Clusters

NASA Astrophysics Data System (ADS)

Naiman, J. P.; Ramirez-Ruiz, E.; Lin, D. N. C.

2018-05-01

Mass and energy injection throughout the lifetime of a star cluster contributes to the gas reservoir available for subsequent episodes of star formation and the feedback energy budget responsible for ejecting material from the cluster. In addition, mass processed in stellar interiors and ejected as winds has the potential to augment the abundance ratios of currently forming stars, or stars which form at a later time from a retained gas reservoir. Here we present hydrodynamical simulations that explore a wide range of cluster masses, compactnesses, metallicities and stellar population age combinations in order to determine the range of parameter space conducive to stellar wind retention or wind powered gas expulsion in star clusters. We discuss the effects of the stellar wind prescription on retention and expulsion effectiveness, using MESA stellar evolutionary models as a test bed for exploring how the amounts of wind retention/expulsion depend upon the amount of mixing between the winds from stars of different masses and ages. We conclude by summarizing some implications for gas retention and expulsion in a variety of compact (σv ≳ 20 kms-1) star clusters including young massive star clusters (105 ≲ M/M⊙ ≲ 107, age ≲ 500 Myrs), intermediate age clusters (105 ≲ M/M⊙ ≲ 107, age ≈ 1 - 4 Gyrs), and globular clusters (105 ≲ M/M⊙ ≲ 107, age ≳ 10 Gyrs).

A new procedure for the determination of distillation temperature distribution of high-boiling petroleum products and fractions.

PubMed

Boczkaj, Grzegorz; Przyjazny, Andrzej; Kamiński, Marian

2011-03-01

The distribution of distillation temperatures of liquid and semi-fluid products, including petroleum fractions and products, is an important process and practical parameter. It provides information on properties of crude oil and content of particular fractions, classified on the basis of their boiling points, as well as the optimum conditions of atmospheric or vacuum distillation. At present, the distribution of distillation temperatures is often investigated by simulated distillation (SIMDIS) using capillary gas chromatography (CGC) with a short capillary column with polydimethylsiloxane as the stationary phase. This paper presents the results of investigations on the possibility of replacing currently used CGC columns for SIMDIS with a deactivated fused silica capillary tube without any stationary phase. The SIMDIS technique making use of such an empty fused silica column allows a considerable lowering of elution temperature of the analytes, which results in a decrease of the final oven temperature while ensuring a complete separation of the mixture. This eliminates the possibility of decomposition of less thermally stable mixture components and bleeding of the stationary phase which would result in an increase of the detector signal. It also improves the stability of the baseline, which is especially important in the determination of the end point of elution, which is the basis for finding the final temperature of distillation. This is the key parameter for the safety process of hydrocracking, where an excessively high final temperature of distillation of a batch can result in serious damage to an expensive catalyst bed. This paper compares the distribution of distillation temperatures of the fraction from vacuum distillation of petroleum obtained using SIMDIS with that obtained by the proposed procedure. A good agreement between the two procedures was observed. In addition, typical values of elution temperatures of n-paraffin standards obtained by the two procedures were compared. Finally, the agreement between boiling points of polar compounds determined from their retention times and actual boiling points was investigated.

[Acute urinary retention secondary to giant prolapsed ureterocele in a young adult woman. Case report].

PubMed

Villagómez-Camargo, Roberto; Chopin-Gazga, Marco; Saucedo-Bravo, Jonathan; García-Cano, Eugenio; Montiel-Jarquín, Álvaro

2016-01-01

Ureterocele is a cystic dilation of the distal ureteral segment. The incidence in women ranges from 1/5,000 to 1/12,000. In adults, they are poorly diagnosed and are asymptomatic. Prolapse through the urethra is uncommon, and involves acute urine retention and a reducible vulvar tumour. Woman of 24 years old, two previous caesarean and two abortions. She had incomplete bladder emptying, intermittent voiding, bladder straining and tenesmus, three months before admission. After the voiding effort she presented with acute urine retention with sudden onset of tumour in the vulva. The tumour was manually reduced under regional anaesthesia. A cystoscopy was performed, finding an ischaemic de-roofing of the anterior wall of the ureterocele, causing vesicoureteral reflux grade IV. Surgical correction was performed with Cohen re-implantation and insertion of a double-J catheter. The catheter was removed 30 days later, with a successful post-operative course. Its aetiology is unclear, and most are diagnosed by ultrasound in the prenatal period. The clinical presentation is variable, from urinary tract infection to prolapse. Despite its size, it may cause complications such as ischaemic de-roofing, which if diagnosed soon may be resolved successfully, as with this patient. The results and treatment may be favourable when no renal impact or concomitant anatomical changes are present, as is the case of this patient. Copyright © 2015 Academia Mexicana de Cirugía A.C. Published by Masson Doyma México S.A. All rights reserved.

Accumulation of heavy metals and trace elements in fluvial sediments received effluents from traditional and semiconductor industries

PubMed Central

Hsu, Liang-Ching; Huang, Ching-Yi; Chuang, Yen-Hsun; Chen, Ho-Wen; Chan, Ya-Ting; Teah, Heng Yi; Chen, Tsan-Yao; Chang, Chiung-Fen; Liu, Yu-Ting; Tzou, Yu-Min

2016-01-01

Metal accumulation in sediments threatens adjacent ecosystems due to the potential of metal mobilization and the subsequent uptake into food webs. Here, contents of heavy metals (Cd, Cr, Cu, Ni, Pb, and Zn) and trace elements (Ga, In, Mo, and Se) were determined for river waters and bed sediments that received sewage discharged from traditional and semiconductor industries. We used principal component analysis (PCA) to determine the metal distribution in relation to environmental factors such as pH, EC, and organic matter (OM) contents in the river basin. While water PCA categorized discharged metals into three groups that implied potential origins of contamination, sediment PCA only indicated a correlation between metal accumulation and OM contents. Such discrepancy in metal distribution between river water and bed sediment highlighted the significance of physical-chemical properties of sediment, especially OM, in metal retention. Moreover, we used Se XANES as an example to test the species transformation during metal transportation from effluent outlets to bed sediments and found a portion of Se inventory shifted from less soluble elemental Se to the high soluble and toxic selenite and selenate. The consideration of environmental factors is required to develop pollution managements and assess environmental risks for bed sediments. PMID:27681994

Accumulation of heavy metals and trace elements in fluvial sediments received effluents from traditional and semiconductor industries.

PubMed

Hsu, Liang-Ching; Huang, Ching-Yi; Chuang, Yen-Hsun; Chen, Ho-Wen; Chan, Ya-Ting; Teah, Heng Yi; Chen, Tsan-Yao; Chang, Chiung-Fen; Liu, Yu-Ting; Tzou, Yu-Min

2016-09-29

Metal accumulation in sediments threatens adjacent ecosystems due to the potential of metal mobilization and the subsequent uptake into food webs. Here, contents of heavy metals (Cd, Cr, Cu, Ni, Pb, and Zn) and trace elements (Ga, In, Mo, and Se) were determined for river waters and bed sediments that received sewage discharged from traditional and semiconductor industries. We used principal component analysis (PCA) to determine the metal distribution in relation to environmental factors such as pH, EC, and organic matter (OM) contents in the river basin. While water PCA categorized discharged metals into three groups that implied potential origins of contamination, sediment PCA only indicated a correlation between metal accumulation and OM contents. Such discrepancy in metal distribution between river water and bed sediment highlighted the significance of physical-chemical properties of sediment, especially OM, in metal retention. Moreover, we used Se XANES as an example to test the species transformation during metal transportation from effluent outlets to bed sediments and found a portion of Se inventory shifted from less soluble elemental Se to the high soluble and toxic selenite and selenate. The consideration of environmental factors is required to develop pollution managements and assess environmental risks for bed sediments.

Accumulation of heavy metals and trace elements in fluvial sediments received effluents from traditional and semiconductor industries

NASA Astrophysics Data System (ADS)

Hsu, Liang-Ching; Huang, Ching-Yi; Chuang, Yen-Hsun; Chen, Ho-Wen; Chan, Ya-Ting; Teah, Heng Yi; Chen, Tsan-Yao; Chang, Chiung-Fen; Liu, Yu-Ting; Tzou, Yu-Min

2016-09-01

Metal accumulation in sediments threatens adjacent ecosystems due to the potential of metal mobilization and the subsequent uptake into food webs. Here, contents of heavy metals (Cd, Cr, Cu, Ni, Pb, and Zn) and trace elements (Ga, In, Mo, and Se) were determined for river waters and bed sediments that received sewage discharged from traditional and semiconductor industries. We used principal component analysis (PCA) to determine the metal distribution in relation to environmental factors such as pH, EC, and organic matter (OM) contents in the river basin. While water PCA categorized discharged metals into three groups that implied potential origins of contamination, sediment PCA only indicated a correlation between metal accumulation and OM contents. Such discrepancy in metal distribution between river water and bed sediment highlighted the significance of physical-chemical properties of sediment, especially OM, in metal retention. Moreover, we used Se XANES as an example to test the species transformation during metal transportation from effluent outlets to bed sediments and found a portion of Se inventory shifted from less soluble elemental Se to the high soluble and toxic selenite and selenate. The consideration of environmental factors is required to develop pollution managements and assess environmental risks for bed sediments.

Anaerobic treatment of winery wastewater in fixed bed reactors.

PubMed

Ganesh, Rangaraj; Rajinikanth, Rajagopal; Thanikal, Joseph V; Ramanujam, Ramamoorty Alwar; Torrijos, Michel

2010-06-01

The treatment of winery wastewater in three upflow anaerobic fixed-bed reactors (S9, S30 and S40) with low density floating supports of varying size and specific surface area was investigated. A maximum OLR of 42 g/l day with 80 +/- 0.5% removal efficiency was attained in S9, which had supports with the highest specific surface area. It was found that the efficiency of the reactors increased with decrease in size and increase in specific surface area of the support media. Total biomass accumulation in the reactors was also found to vary as a function of specific surface area and size of the support medium. The Stover-Kincannon kinetic model predicted satisfactorily the performance of the reactors. The maximum removal rate constant (U(max)) was 161.3, 99.0 and 77.5 g/l day and the saturation value constant (K(B)) was 162.0, 99.5 and 78.0 g/l day for S9, S30 and S40, respectively. Due to their higher biomass retention potential, the supports used in this study offer great promise as media in anaerobic fixed bed reactors. Anaerobic fixed-bed reactors with these supports can be applied as high-rate systems for the treatment of large volumes of wastewaters typically containing readily biodegradable organics, such as the winery wastewater.

Effects of intermittent aeration periods on a structured-bed reactor continuously fed on the post-treatment of sewage anaerobic effluent.

PubMed

Silva, Bruno Garcia; Damianovic, Márcia Helena Rissato Zamariolli; Foresti, Eugenio

2018-04-20

This study assessed the simultaneous nitrification and denitrification processes and remaining organic matter removal from anaerobic reactor effluent treating wastewater in a single reactor. A structured-bed reactor, with polyurethane foam as support media, was subjected to intermittent aeration and effluent recirculation. Aerated/non-aerated periods varied in the range of 2/1-1/3 h. The chemical oxygen demand (COD) in the effluent remained between 26 and 42 mg L -1 throughout all the aeration conditions. Aeration periods of 1/2 h removed 80 and 26% of Total Kjeldahl Nitrogen and Total Nitrogen, respectively. A low solid production was observed during the 300 days of operation, resulting in a solid retention time of 139 days. The results indicate that the non-aerated periods generated alkalinity that favored nitrification, maintaining low COD concentrations in the effluent. The structured bed reactor presented a low solid production and effluent loss below 20 mgSSV L -1 , similar to concentrations obtained in secondary decanters.

Use of laterite for the removal of fluoride from contaminated drinking water.

PubMed

Sarkar, Mitali; Banerjee, Aparna; Pramanick, Partha Pratim; Sarkar, Asit R

2006-10-15

The effects of different operational variables on the mechanistic function of laterite in removal of fluoride have been investigated. Thermodynamic parameters such as free energy change, enthalpy, and entropy of the process, as well as the sorption isotherm, were evaluated. The extent of solute removal is determined by initial solute concentration, operational conditions, laterite dose, and solution pH. For a fixed set of experimental conditions, a model equation is developed from which the percent removal corresponding to each load of fluoride is determined. The mechanism of fluoride adsorption is governed by the zero point charge of laterite and follows a first-order rate equation. pH has a vital role influencing the surface characteristics of laterite. To simulate the flow dynamics, fluoride solution was run through a fixed bed column. The pattern of breakthrough curves for different influent fluoride concentration, pH, and column bed height was characterized. The column efficiency was tested from the bed depth-service time model. The elution of the retained fluoride was studied and the effectiveness of column operation was determined by the retention-elution cycles.

Full scale fluidized bed anaerobic reactor for domestic wastewater treatment: performance, sludge production and biofilm.

PubMed

Mendonça, N M; Niciura, C L; Gianotti, E P; Campos, J R

2004-01-01

This paper describes the performance, sludge production and biofilm characteristics of a full scale fluidized bed anaerobic reactor (32 m3) for domestic wastewater treatment. The reactor was operated with 10.5 m x h(-1) upflow velocity, 3.2 h hydraulic retention time, and recirculation ratio of 0.85 and it presented removal efficiencies of 71+/-8% of COD and 77+/-14% of TSS. During the apparent steady-state period, specific sludge production and sludge age in the reactor were (0.116+/-0.033) kgVSS. kgCOD(-1) and (12+/-5)d, respectively. Biofilm formed in the reactor presented two different patterns: one of them at the beginning of the colonization and the other of mature biofilm. These different colonization patterns are due to bed stratification in the reactor, caused by the difference in local-energy dissipation rates along the reactor's height, and density, shape, etc. of the bioparticles. The biofilm population is formed mainly of syntrophic consortia among sulfate reducing bacteria, methanogenic archaea such as Methanobacterium and Methanosaeta-like cells.

Proximal and Overall Gastric Emptying of Solids in Patients with Reduced Gastric Volume Accommodation Compared to Matched Controls

PubMed Central

Camilleri, Michael; Breen, Mary; Ryks, Michael; Burton, Duane

2011-01-01

Background Interventions such as gastric surgery and erythromycin result in displacement of solids to the distal stomach and acceleration of overall and proximal gastric emptying. The effect of non-surgical impairment of gastric accommodation on gastric emptying is unclear. Non-surgical impairment of gastric accommodation is associated with accelerated gastric emptying. Aim To compare measurements of proximal and overall gastric emptying in patients with reduced postprandial gastric volume accommodation with the emptying rates in age- and gender-matched controls with normal postprandial gastric volume accommodation. Methods We evaluated overall and proximal gastric emptying in 9 patients with impaired gastric accommodation and age-equivalent and gender-matched controls. Gastric volumes and emptying were measured using validated SPECT and dual gamma camera scintigraphy respectively. We compared group differences in overall and proximal gastric emptying t1/2 by t test. Results Patients with impaired postprandial gastric volume accommodation had greater fasting gastric volume. The proportion of food emptied from the proximal stomach immediately after meal ingestion was lower and t1/2of proximal gastric emptying correspondingly longer in the group with reduced postprandial gastric accommodation. In contrast, differences were not detected in overall gastric emptying in the two groups, and the ratio of overall to proximal gastric emptying t1/2was greater in the group with impaired volume accommodation. Conclusions Proximal stomach emptying is reduced in patients with impaired postprandial volume accommodation; this difference occurs predominantly during the time of meal ingestion. Compensatory mechanisms that result in normal overall gastric emptying require further elucidation. PMID:21327917

The role of mesopores in MTBE removal with granular activated carbon.

PubMed

Redding, Adam M; Cannon, Fred S

2014-06-01

This activated carbon research appraised how pore size and empty-bed contact time influenced the removal of methyl tert-butyl ether (MTBE) at part-per-billion (ppb) concentrations when MTBE was the sole organic impurity. The study compared six granular activated carbons (GACs) from three parent sources; these GACs contained a range of pore volume distributions and had uniform slurry pHs of 9.7-10.4 (i.e. the carbons' bulk surface chemistries were basic). Several of these activated carbons had been specifically tailored for enhanced sorption of trace organic compounds. In these tests, MTBE was spiked into deionized-distilled water (∼pH 7); MTBE loading was measured by isotherms and by rapid small-scale column tests (RSSCTs) that simulated full-scale empty-bed contact times of 7, 14, and 28 min. The results showed that both ultra-fine micropores and small-diameter mesopores were important for MTBE adsorption. Specifically, full MTBE loading during RSSCTs bore a strong correlation (R(2) = 0.94) to the product (mL/g × mL/g) of pore volume ≤4.06 Å wide and pore volume between ∼22 Å and ∼59 Å wide. This correlation was greater than for the product of any other pore volume combinations. Also, this product exhibited a stronger correlation than for just one or the other of these two pore ranges. This multiplicative relationship implied that both of these pore sizes were important for the optimum GAC performance of these six carbons (i.e. favorable mass transfer coupled with favorable sorption). The authors also compared MTBE mass loading during RSSCTs (μg MTBE/g GAC) to isotherm capacity (μg MTBE/g GAC). This RSSCT loading "efficiency" ranged from 28% to 96% for the six GACs; this efficiency correlated most strongly to pores that were 14-200 Å wide (R(2) = 0.94). This correlation indicated that only those carbons with a sufficient volume of 14-200 Å pores could adsorb MTBE to the extent that would be predicted from isotherm data. Copyright © 2014 Elsevier Ltd. All rights reserved.

Macrofaunal involvement in the sublittoral decay of kelp debris: The sea urchin Psammechinus miliaris (Gmelin) (Echinodermata: Echinoidea)

NASA Astrophysics Data System (ADS)

Bedford, A. P.; Moore, P. G.

1985-01-01

Psammechinus miliaris occurs in the Clyde Sea area in large numbers (<18 individuals per 100 g -1 weed dry wt) on sublittoral beds of detached Laminaria saccharina. Its rôle in weed decomposition has been examined by comparing its responses (behavioural choice, growth rate, absorption efficiencies of both carbon and protein, gut retention times and rate of faecal output) to fresh and rotting weed. Younger urchins grew faster than older individuals on a diet of rotting weed but not on fresh weed. Large seasonal variation existed, however, with fast growth occurring in June-August and little, or no, growth in December-February, irrespective of diet. Starved controls did not grow. Correcting for seasonality, rotting kelp still promoted faster growth of young urchins than did fresh weed. Larger (older) individuals showed no difference. Urchins fed fresh weed had significantly longer gut retention times. Protein absorption efficiency was higher on fresh than rotting weed, varying with weed protein content and size of urchin. Very young individuals can only digest high protein weed efficiently, eg. material derived from near the frond meristem. Organic carbon content of rotting weed was significantly lower than fresh weed. Carbon absorption efficiencies were significantly higher on fresh weed which related to organic carbon content. Standard-sized urchins fed rotting weed produced larger dry weights of faeces per day, reflecting increased ingestion rate. In closed-system choice experiments urchins preferred rotting weed kinetically. Size-frequency analysis of field populations suggested that weed beds are principally colonized by larval settlement from the plankton. Mature Psammechinus have evolved different 'strategies' for exploiting fresh and rotting weed. Fresh weed is relatively difficult to digest and long gut retention times allow high protein absorption efficiencies to be attained. Rotting weed has microbial protein in quantities and a lower organic carbon fraction. Some bacterial protein is seemingly unavailable though and lower protein absorption efficiencies result. Thus gut retention time is shortened and more food passed through the gut. Growth remains equivalent. Substratum digestion is of paramount importance for Psammechinus feeding on either fresh or rotting weed, cf. the 'classical' microbe-stripping detritivore of Fenchel.

Effect of guar gum added to the diet of patients with duodenal ulcer.

PubMed

Harju, E J; Larmi, T K

1985-01-01

In a randomized, double-blind, controlled clinical study, the effects of 5 g of guar gum, a dietary fiber composed of galactose and mannose, or placebo added to the diet of 20 patients with duodenal ulcer for 1 wk each were examined. Ten patients derived evident benefit and five some help from guar gum, on comparing symptoms during administration of guar gum with those experienced earlier or during the placebo week, whereas four patients found that neither guar gum nor placebo had any effect (p less than 0.001). The beneficial effect was associated with increased feelings of repletion after meals. Patients with fewest symptoms benefited only slightly, or not at all, from guar gum. In one patient, guar gum abolished pain felt earlier and on placebo, but also caused severe gastric retention after meals. This patient had pyloric stenosis. In patients who were intolerant to berries, fruits, sugar, sweet rolls, and pizza these foodstuffs were better tolerated during guar gum administration. The diarrhea which occurs in some patients ingesting guar gum was avoided by giving low initial doses. In three patients unpalatability of guar gum was a minor complaint. It is concluded that guar gum is helpful to many patients with uncomplicated duodenal ulcer, but that it is harmful to those having increased gastric emptying, eg, pyloric stenosis patients, and that guar gum may exert its effects by increasing gastric emptying time.

Human-facilitated metapopulation dynamics in an emerging pest species, Cimex lectularius

PubMed Central

FOUNTAIN, TOBY; DUVAUX, LUDOVIC; HORSBURGH, GAVIN; REINHARDT, KLAUS; BUTLIN, ROGER K

2014-01-01

The number and demographic history of colonists can have dramatic consequences for the way in which genetic diversity is distributed and maintained in a metapopulation. The bed bug (Cimex lectularius) is a re-emerging pest species whose close association with humans has led to frequent local extinction and colonization, that is, to metapopulation dynamics. Pest control limits the lifespan of subpopulations, causing frequent local extinctions, and human-facilitated dispersal allows the colonization of empty patches. Founder events often result in drastic reductions in diversity and an increased influence of genetic drift. Coupled with restricted migration, this can lead to rapid population differentiation. We therefore predicted strong population structuring. Here, using 21 newly characterized microsatellite markers and approximate Bayesian computation (ABC), we investigate simplified versions of two classical models of metapopulation dynamics, in a coalescent framework, to estimate the number and genetic composition of founders in the common bed bug. We found very limited diversity within infestations but high degrees of structuring across the city of London, with extreme levels of genetic differentiation between infestations (FST = 0.59). ABC results suggest a common origin of all founders of a given subpopulation and that the numbers of colonists were low, implying that even a single mated female is enough to found a new infestation successfully. These patterns of colonization are close to the predictions of the propagule pool model, where all founders originate from the same parental infestation. These results show that aspects of metapopulation dynamics can be captured in simple models and provide insights that are valuable for the future targeted control of bed bug infestations. PMID:24446663

Effect of colectomy on gastric emptying in idiopathic slow-transit constipation.

PubMed

Hemingway, D M; Finlay, I G

2000-09-01

Gastric emptying is delayed in patients with idiopathic slow-transit constipation (ISTC). Gastric emptying was measured before and after colectomy and ileorectal anastomosis in patients with ISTC to determine whether the abnormality persists after operation. Twelve patients undergoing colectomy for severe ISTC had solid-phase gastric emptying measured after an overnight fast. All 12 had an uncomplicated subtotal colectomy and ileorectal anastomosis; 11 had an excellent functional outcome. In ten of these patients gastric emptying was repeated within 3 months of operation. Seven patients (including the remaining two) had the study performed at 1 year. All 12 patients had severely delayed gastric emptying before operation. Gastric emptying remained delayed in the ten patients who underwent an early postoperative gastric emptying study. Six of seven patients assessed at 1 year had improved gastric emptying, of whom four had returned to normal. Functional outcome did not relate to gastric emptying. Patients with ISTC have delayed gastric emptying. In some patients this returns to normal after colectomy, but is persistent in others. This may have implications for our understanding of ISTC.

Contactor/filter improvements

DOEpatents

Stelman, David

1989-01-01

A contactor/filter arrangement for removing particulate contaminants from a gaseous stream includes a housing having a substantially vertically oriented granular material retention member with upstream and downstream faces, a substantially vertically oriented microporous gas filter element, wherein the retention member and the filter element are spaced apart to provide a zone for the passage of granular material therethrough. The housing further includes a gas inlet means, a gas outlet means, and means for moving a body of granular material through the zone. A gaseous stream containing particulate contaminants passes through the gas inlet means as well as through the upstream face of the granular material retention member, passing through the retention member, the body of granular material, the microporous gas filter element, exiting out of the gas outlet means. Disposed on the upstream face of the filter element is a cover screen which isolates the filter element from contact with the moving granular bed and collects a portion of the particulates so as to form a dust cake having openings small enough to exclude the granular material, yet large enough to receive the dust particles. In one embodiment, the granular material is comprised of prous alumina impregnated with CuO, with the cover screen cleaned by the action of the moving granular material as well as by backflow pressure pulses.

Measurement of gastric emptying during and between meal intake in free-feeding Lewis rats.

PubMed

van der Velde, P; Koslowsky, I; Koopmans, H S

1999-02-01

A new scintigraphic measurement technique is described that allows accurate assessment of gastric emptying in between as well as during a number of successive meals. Measurements were made every minute of food intake, gastric nutrient filling, and gastric emptying over a 6 h, 40 min period in conscious, free-feeding, loosely restrained rats. Before receiving access to the food, the animals had been deprived for a period of 31 h. Over the full duration of the experiment, an average rate of gastric emptying of 2.46 +/- 0.18 (SE) kcal/h was established. During most meals, however, the gastric emptying rate was increased so that an average of 26.9 +/- 2.7% of the ingested calories was emptied while the animals were feeding, with an average emptying rate of 0.15 +/- 0.014 kcal/min or 8.88 +/- 0.84 kcal/h. This transient increase in the rate of gastric emptying was followed by a subsequent slowing of gastric emptying after meal termination; in the 10-min postmeal interval, an average emptying rate of 0.96 +/- 0.12 kcal/h was found. Despite these fluctuations during and immediately after meals, a relatively constant rate of caloric emptying is maintained over longer periods. There were no differences between the emptying rate during the first meal when the gastrointestinal tract was still empty, compared with later meals when the gastrointestinal tract had been filled with food. The emptying rate during the 10-min postmeal interval, however, was significantly reduced during later meals. The results suggest that gastric emptying is controlled by different mechanisms during and after the ingestion of food and that these mechanisms remain in effect at various degrees of gastrointestinal filling.

Thermal-Hydraulic Transient Analysis of a Packed Particle Bed Reactor Fuel Element

DTIC Science & Technology

1990-06-01

long fuel elements, arranged to form a core , were analyzed for an up-power transient from 0 MWt to approximately 18 MWt. The simple model significantly...VARIATIONS IN FUEL ELEMENT GEOMETRY ............. 60 4.4 VARIATIONS IN THE MANNER OF TRANSIENT CONTROL ..... 62 4.5 CORE REPRESENTATION BY MULTIPLE FUEL ...the HTGR , however, the PBR packs small fuel particles between inner and outer retention elements, designated as frits. The PBR is appropriate for a

The Importance of Fine-Scale Flow Processes and Food Availability in the Maintenance of Soft-Sediment Communities

DTIC Science & Technology

1993-02-01

of the bottom sediments at a given site. From long time -series measurements of the flow and sediment-transport environment on Georges Bank...significantly affect flows and sediment transport depends, in part, on timing . Biological effects on seafloor stability may be more pronounced, for example...potentially can enhance particle retention time within the tube bed via skimming flow (described earlier), although it is unclear if natural populations of

[Study on the calcium-based sorbent for removal fluorine during coal combustion].

PubMed

Li, Shu-ling; Qi, Qing-jie; Liu, Jian-zhong; Cao, Xin-yu; Zhou, Jun-hu; Cen, Ke-fa

2004-03-01

In the paper, the reaction of CaO-HF and fluorine removal mechanics at high temperature by blending calcium-based sorbents with coal during coal combustion were discussed, and test results about fluorine retention during coal combustion in fluidized bed and chain-grate furnace were reported. The results identified that lime and calcium-based sorbets developed can restratin the emission of fluorine during coal combustion. The efficiency of fluorine removal can reach 66.7%-70.0% at Ca/F 60-70 by blending lime with coal in fluidized bed combustion, and the efficiency of fluorine removal are between 57.32% and 75.19% by blending calcium-based sorbets with coal in chain-grate furnace combustion. Blending CaO or lime with coal during coal combustion can remove SO2 and HF simultaneously.

Difficulties in maintaining long-term partial nitritation of ammonium-rich sludge digester liquids in a moving-bed biofilm reactor (MBBR).

PubMed

Fux, C; Huang, D; Monti, A; Siegrist, H

2004-01-01

Nitrogen can be eliminated effectively from sludge digester effluents by anaerobic ammonium oxidation (anammox), but 55-60% of the ammonium must first be oxidized to nitrite. Although a continuous flow stirred tank reactor (CSTR) with suspended biomass could be used, its hydraulic dilution rate is limited to 0.8-1 d(-1) (30 degrees C). Higher specific nitrite production rates can be achieved by sludge retention, as shown here for a moving-bed biofilm reactor (MBBR) with Kaldnes carriers on laboratory and pilot scales. The maximum nitrite production rate amounted to 2.7 gNO2-Nm(-2)d(-1) (3 gO2m(-3)d(-1), 30.5 degrees C), thus doubling the dilution rate compared to CSTR operation with suspended biomass for a supernatant with 700 gNH4-Nm(-3). Whenever the available alkalinity was fully consumed, an optimal amount of nitrite was produced. However, a significant amount of nitrate was produced after 11 months of operation, making the effluent unsuitable for anaerobic ammonium oxidation. Because the sludge retention time (SRT) is relatively long in biofilm systems, slow growth of nitrite oxidizers occurs. None of the selection criteria applied - a high ammonium loading rate, high free ammonia or low oxygen concentration - led to selective suppression of nitrite oxidation. A CSTR or SBR with suspended biomass is consequently recommended for full-scale operation.

Alkali activation of recovered fuel-biofuel fly ash from fluidised-bed combustion: Stabilisation/solidification of heavy metals.

PubMed

Yliniemi, Juho; Pesonen, Janne; Tiainen, Minna; Illikainen, Mirja

2015-09-01

Recovered fuel-biofuel fly ash from a fluidized bed boiler was alkali-activated and granulated with a sodium-silicate solution in order to immobilise the heavy metals it contains. The effect of blast-furnace slag and metakaolin as co-binders were studied. Leaching standard EN 12457-3 was applied to evaluate the immobilisation potential. The results showed that Ba, Pb and Zn were effectively immobilised. However, there was increased leaching after alkali activation for As, Cu, Mo, Sb and V. The co-binders had minimal or even negative effect on the immobilisation. One exception was found for Cr, in which the slag decreased leaching, and one was found for Cu, in which the slag increased leaching. A sequential leaching procedure was utilized to gain a deeper understanding of the immobilisation mechanism. By using a sequential leaching procedure it is possible fractionate elements into watersoluble, acid-soluble, easily-reduced and oxidisable fractions, yielding a total 'bioavailable' amount that is potentially hazardous for the environment. It was found that the total bioavailable amount was lower following alkali activation for all heavy metals, although the water-soluble fraction was higher for some metals. Evidence from leaching tests suggests the immobilisation mechanism was chemical retention, or trapping inside the alkali activation reaction products, rather than physical retention, adsorption or precipitation as hydroxides. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effects of magnolol and honokiol derived from traditional Chinese herbal remedies on gastrointestinal movement

PubMed Central

Zhang, Wei-Wei; Li, Yan; Wang, Xue-Qing; Tian, Feng; Cao, Hong; Wang, Min-Wei; Sun, Qi-Shi

2005-01-01

AIM: To study the effects of magnolol and honokiol on isolated smooth muscle of gastrointestinal tract and their relationship with Ca2+, and on the gastric emptying and the intestinal propulsive activity in mice. METHODS: Routine experimental methods using isolated gastric fundus strips of rats and isolated ileum segments of guinea pigs were adopted to measure the smooth muscle tension. The effects of magnolol 10-3, 10-4, 10-5 mol/L, and honokiol 10-4, 10-5, 10-6 mol/L on the contractility of gastric fundus strips of rats and ileum of guinea pigs induced by acetylcholine (Ach) and 5-hydroxytryptamine (5-HT) was assessed respectively. The method using nuclein and pigment methylene blue was adopted to measure the gastric retention rate of nuclein and the intestinal propulsive ratio of a nutritional semi-solid meal for assessing the effect of magnolol and honokiol (0.5, 2, 20 mg/kg) on gastric emptying and intestinal propulsion. RESULTS: Magnolol and honokiol significantly inhibited the contractility of isolated gastric fundus strips of rats treated with Ach or 5-HT and isolated ileum guinea pigs treated with Ach or CaCl2, and both of them behaved as non-competitive muscarinic antagonists. Magnolol and honokiol inhibited the contraction induced by Ach in Ca2+-free medium and extracellular Ca2+-dependent contraction induced by Ach. Each group of magnolol and honokiol experiments significantly decreased the residual rate of nuclein in the stomach and increased the intestinal propulsive ratio in mice. CONCLUSION: The inhibitory effect of magnolol and honokiol on contractility of the smooth muscles of isolated gastric fundus strips of rats and isolated ileum of guinea pigs is associated with a calcium-antagonistic effect. Magnolol and honokiol can improve the gastric emptying of a semi-solid meal and intestinal propulsive activity in mice. PMID:16038044

Chlordecone disappearance in tissues of growing goats after a one month decontamination period--effect of body fatness on chlordecone retention.

PubMed

Lastel, Marie-Laure; Lerch, Sylvain; Fournier, Agnès; Jurjanz, Stefan; Mahieu, Maurice; Archimède, Harry; Feidt, Cyril; Rychen, Guido

2016-02-01

Chlordecone (CLD) is an organochlorine pesticide whose extended use led to the contamination of at least 20% of agricultural soils from the French West Indies. Livestock reared on polluted areas are involuntary contaminated by CLD and their level of contamination may exceed the threshold values set by the European Union. Thus, characterizing the CLD behaviour in farm animals appear as a real issue in terms of food safety for local populations. The aim of this experiment was (i) to characterize the CLD disappearance in various tissues after exposure cessation and (ii) to evaluate the potential effect of body fatness on this process. Two groups of eight growing goats were submitted to either a basal diet or a high energy diet for 50 days before being intravenously contaminated with 1 mg CLD kg(-1) body weight. Two days after CLD contamination, half of the kids of each experimental group were slaughtered in order to determine pollutant levels in the serum, liver, adipose tissues, and empty carcass. The remaining animals were submitted to a 30-day decontamination period before slaughtering and measurements as described above. The implemented nutritional plan resulted in both groups of kids with significant differences in terms of body fatness. CLD was mainly concentrated in the liver of animals as described in the literature. It was found also in kids' empty carcass and adipose tissues; however its levels in the empty carcass (muscles and bones) were unexpected since they were higher than in fat. These results indicate that the lipophilic pollutant CLD is found mainly in liver but also in muscles and fat. Concerning the animals' depuration, a 30-d decontamination period was sufficient to observe a decrease of CLD levels by more than 75% in both experimental groups and neither CLD concentrations nor CLD amounts were significantly affected by kids' body fatness.

Reduction of the hydraulic retention time at constant high organic loading rate to reach the microbial limits of anaerobic digestion in various reactor systems.

PubMed

Ziganshin, Ayrat M; Schmidt, Thomas; Lv, Zuopeng; Liebetrau, Jan; Richnow, Hans Hermann; Kleinsteuber, Sabine; Nikolausz, Marcell

2016-10-01

The effects of hydraulic retention time (HRT) reduction at constant high organic loading rate on the activity of hydrogen-producing bacteria and methanogens were investigated in reactors digesting thin stillage. Stable isotope fingerprinting was additionally applied to assess methanogenic pathways. Based on hydA gene transcripts, Clostridiales was the most active hydrogen-producing order in continuous stirred tank reactor (CSTR), fixed-bed reactor (FBR) and anaerobic sequencing batch reactor (ASBR), but shorter HRT stimulated the activity of Spirochaetales. Further decreasing HRT diminished Spirochaetales activity in systems with biomass retention. Based on mcrA gene transcripts, Methanoculleus and Methanosarcina were the predominantly active in CSTR and ASBR, whereas Methanosaeta and Methanospirillum activity was more significant in stably performing FBR. Isotope values indicated the predominance of aceticlastic pathway in FBR. Interestingly, an increased activity of Methanosaeta was observed during shortening HRT in CSTR and ASBR despite high organic acids concentrations, what was supported by stable isotope data. Copyright © 2016 Elsevier Ltd. All rights reserved.

Performance of a system with full- and pilot-scale sludge drying reed bed units treating septic tank sludge in Brazil.

PubMed

Calderón-Vallejo, Luisa Fernanda; Andrade, Cynthia Franco; Manjate, Elias Sete; Madera-Parra, Carlos Arturo; von Sperling, Marcos

2015-01-01

This study investigated the performance of sludge drying reed beds (SDRB) at full- and pilot-scale treating sludge from septic tanks in the city of Belo Horizonte, Brazil. The treatment units, planted with Cynodon spp., were based on an adaptation of the first-stage of the French vertical-flow constructed wetland, originally developed for treating sewage. Two different operational phases were investigated; in the first one, the full-scale unit was used together with six pilot-scale columns in order to test different feeding strategies. For the second phase, only the full-scale unit was used, including a recirculation of the filtered effluent (percolate) to one of the units of the French vertical wetland. Sludge application was done once a week emptying a full truck, during 25 weeks. The sludge was predominantly diluted, leading to low solids loading rates (median values of 18 kgTS m(-2) year(-1)). Chemical oxygen demand removal efficiency in the full-scale unit was reasonable (median of 71%), but the total solids removal was only moderate (median of 44%) in the full-scale unit without recirculation. Recirculation did not bring substantial improvements in the overall performance. The other loading conditions implemented in the pilot columns also did not show statistically different performances.

Methane biofiltration in the presence of ethanol vapor under steady and transient state conditions: an experimental study.

PubMed

Ferdowsi, Milad; Ramirez, Antonio Avalos; Jones, Joseph Peter; Heitz, Michèle

2017-09-01

Methane (CH 4 ) removal in the presence of ethanol vapors was performed by a stone-based bed and a hybrid packing biofilter in parallel. In the absence of ethanol, a methane removal efficiency of 55 ± 1% was obtained for both biofilters under similar CH 4 inlet load (IL) of 13 ± 0.5 g CH4  m -3  h -1 and an empty bed residence time (EBRT) of 6 min. The results proved the key role of the bottom section in both biofilters for simultaneous removal of CH 4 and ethanol. Ethanol vapor was completely eliminated in the bottom sections for an ethanol IL variation between 1 and 11 g ethanol  m -3  h -1 . Ethanol absorption and accumulation in the biofilm phase as well as ethanol conversion to CO 2 contributed to ethanol removal efficiency of 100%. In the presence of ethanol vapor, CO 2 productions in the bottom section increased almost fourfold in both biofilters. The ethanol concentration in the leachate of the biofilter exceeding 2200 g ethanol  m -3 leachate in both biofilters demonstrated the excess accumulation of ethanol in the biofilm phase. The biofilters responded quickly to an ethanol shock load followed by a starvation with 20% decrease of their performance. The return to normal operations in both biofilters after the transient conditions took less than 5 days. Unlike the hybrid packing biofilter, excess pressure drop (up to 1.9 cmH 2 O m -1 ) was an important concern for the stone bed biofilter. The biomass accumulation in the bottom section of the stone bed biofilter contributed to 80% of the total pressure drop. However, the 14-day starvation reduced the pressure drop to 0.25 cmH 2 O m -1 .

Investigation of Anaerobic Fluidized Bed Reactor/ Aerobic Moving Bed Bio Reactor (AFBR/MMBR) System for Treatment of Currant Wastewater

PubMed Central

JAFARI, Jalil; MESDAGHINIA, Alireza; NABIZADEH, Ramin; FARROKHI, Mehrdad; MAHVI, Amir Hossein

2013-01-01

Background: Anaerobic treatment methods are more suitable for the treatment of concentrated wastewater streams, offer lower operating costs, the production of usable biogas product. The aim of this study was to investigate the performance of an Anaerobic Fluidized Bed Reactor (AFBR)-Aerobic Moving Bed Bio Reactor (MBBR) in series arrangement to treat Currant wastewater. Methods: The bed materials of AFBR were cylindrical particles made of PVC with a diameter of 2–2.3 mm, particle density of 1250 kg/m3. The volume of all bed materials was 1.7 liter which expanded to 2.46 liters in fluidized situation. In MBBR, support media was composed of 1.5 liters Bee-Cell 2000 having porosity of 87% and specific surface area of 650m2/m3. Results: When system operated at 35 ºC, chemical oxygen demand (COD) removal efficiencies were achieved to 98% and 81.6% for organic loading rates (OLR) of 9.4 and 24.2 g COD/l.d, and hydraulic retention times (HRT) of 48 and 18 h, in average COD concentration feeding of 18.4 g/l, respectively. Conclusion: The contribution of AFBR in total COD removal efficiency at an organic loading rate (OLR) of 9.4 g COD/l.d was 95%, and gradually decreased to 76.5% in OLR of 24.2 g COD/l.d. Also with increasing in organic loading rate the contribution of aerobic reactor in removing COD gradually decreased. In this system, the anaerobic reactor played the most important role in the removal of COD, and the aerobic MBBR was actually needed to polish the anaerobic treated wastewater. PMID:26056640

Empty sella associated with growth hormone deficiency and polydactyly.

PubMed

Jurcă, Maria Claudia; Bembea, Marius; Kozma, Kinga; Şandor, Mircea Ioan; Negrean, Rodica Anamaria; Dobjanschi, Luciana; Cuc, Emilia Albiniţa; Petcheşi, Codruţa Diana; Jurcă, Alexandru Daniel

2018-01-01

Empty sella means the absence of the pituitary gland on cranial computed tomography or magnetic resonance imaging. Empty sella syndrome is the pathological variant of the imaging-described empty sella. We present the case of a male Caucasian child, aged four years and two months, for short stature and diagnosed by imaging procedures as empty sella. The cause of short stature was isolated growth hormone (GH) deficiency. Associated he presented left hand postaxial polydactyly. In connection with this particular case, we propose a review of current knowledge in empty sella syndrome. The particularity of reported case consists of association empty sella with GH deficiency and polydactyly. The association of empty sella with polydactyly is not reported yet in the medical literature and is probably coincidental.

Stomach emptiness in fishes: Sources of variation and study design implications

USGS Publications Warehouse

Vinson, M.R.; Angradi, T.R.

2011-01-01

This study summarizes fish stomach content data from 369,000 fish from 402 species in 1,096 collections and reports on the percentage of individuals with empty stomachs. The mean percentage of individuals with empty stomachs among all species, locations, habitats, seasons, regions, and collection methods was 26.4%. Mean percentage of individuals with empty stomachs varied significantly among fish collection gear types, taxonomic orders, trophic groups, feeding behaviors, and habitats, and with species length at maturity. Most of the variation in percentage of individuals with empty stomachs was explained by species length at maturity, fish collection gear type, and two autecological factors: trophic group (piscivore percentage of individuals with empty stomachs > non-piscivore percentage of individuals with empty stomachs) and feeding habitat (water column feeder percentage of individuals with empty stomachs > benthic feeder percentage of individuals with empty stomachs). After accounting for variation with fish length, the percentage of individuals with empty stomachs did not vary with the stomach removal collection method (dissection vs. gastric lavage), feeding time (diurnal or nocturnal), or time of collection (day or night). The percentage of individuals with empty stomachs was similar between fresh and saltwater fish, but differed within finer habitat classifications and appeared to follow a general prey availability or productivity gradient: percentage of individuals with empty stomachs of open ocean collections > estuary collections, lentic > lotic, and pelagic > littoral. Gear type (active or passive) was the most influential factor affecting the occurrence of empty stomachs that can be readily controlled by researchers.

DIN retention-transport through four hydrologically connected zones in a headwater catchment of the Upper Mississippi River

USGS Publications Warehouse

Triska, F.J.; Duff, J.H.; Sheibley, R.W.; Jackman, A.P.; Avanzino, R.J.

2007-01-01

Dissolved inorganic nitrogen (DIN) retention-transport through a headwater catchment was synthesized from studies encompassing four distinct hydrologic zones of the Shingobee River Headwaters near the origin of the Mississippi River. The hydrologic zones included: (1) hillslope ground water (ridge to bankside riparian); (2) alluvial riparian ground water; (3) ground water discharged through subchannel sediments (hyporheic zone); and (4) channel surface water. During subsurface hillslope transport through Zone 1, DIN, primarily nitrate, decreased from ???3 mg-N/l to <0.1 mg-N/l. Ambient seasonal nitrate:chloride ratios in hillslope flow paths indicated both dilution and biotic processing caused nitrate loss. Biologically available organic carbon controlled biotic nitrate retention during hillslope transport. In the alluvial riparian zone (Zone 2) biologically available organic carbon controlled nitrate depletion although processing of both ambient and amended nitrate was faster during the summer than winter. In the hyporheic zone (Zone 3) and stream surface water (Zone 4) DIN retention was primarily controlled by temperature. Perfusion core studies using hyporheic sediment indicated sufficient organic carbon in bed sediments to retain ground water DIN via coupled nitrification-denitrification. Numerical simulations of seasonal hyporheic sediment nitrification-denitrification rates from perfusion cores adequately predicted surface water ammonium but not nitrate when compared to 5 years of monthly field data (1989-93). Mass balance studies in stream surface water indicated proportionally higher summer than winter N retention. Watershed DIN retention was effective during summer under the current land use of intermittently grazed pasture. However, more intensive land use such as row crop agriculture would decrease nitrate retention efficiency and increase loads to surface water. Understanding DIN retention capacity throughout the system, including special channel features such as sloughs, wetlands and floodplains that provide surface water-ground water connectivity, will be required to develop effective nitrate management strategies. ?? 2007 American Water Resources Association.

Aligning quality and payment for heart failure care: defining the challenges.

PubMed

Havranek, Edward P; Krumholz, Harlan M; Dudley, R Adams; Adams, Kirkwood; Gregory, Douglas; Lampert, Steven; Lindenfeld, Joann; Massie, Barry M; Pina, Ileana; Restaino, Susan; Rich, Michael W; Konstam, Marvin A

2003-08-01

Hospitals may not support programs that improve the quality of care delivered to heart failure patients because these programs lower readmission rates and empty beds, and therefore further diminish already-declining revenues. A conflict between the highest quality of care and financial solvency does not serve the interests of patients, physicians, hospitals, or payers. In principle, resolution of this conflict is simple: reimbursement systems should reward higher quality care. In practice, resolving the conflict is not simple. A recent roundtable discussion sponsored by the Heart Failure Society of America identified 4 major challenges to the design and implementation of reimbursement schemes that promote higher quality care for heart failure: defining quality, accounting for differences in disease severity, crafting novel payment mechanisms, and overcoming professional parochialism. This article describes each of these challenges in turn.

A biofilter for treating toluene vapors: performance evaluation and microbial counts behavior

PubMed Central

Zhu, Yazhong; Luo, Yimeng; Ma, Hongye; Wang, Yan

2016-01-01

A lab-scale biofilter packed with mixed packing materials was used for degradation of toluene. Different empty bed residence times, 148.3, 74.2 and 49.4 s, were tested for inlet concentration ranging from 0.2 to 1.2 g/m3. The maximum elimination capacity of 36.0 g/(m3 h) occurred at an inlet loading rate of 45.9 g/(m3 h). The contribution of the lower layer was higher than other layers and always had the highest elimination capacity. The carbon dioxide production rate and distribution of micro-organisms followed toluene elimination capacities. The results of this study indicated that mixed packing materials could be considered as a potential biofilter carrier, with low pressure drop (less than 84.9 Pa/m), for treating air streams containing VOCs. PMID:27231662

Special report. Twin Cities hospital breaks down ambulatory care, overcomes fears of outpatient care.

PubMed

1995-01-06

With payers pushing for shorter hospital stays and outpatient services generating growing shares of hospitals' revenues, experts everywhere are projecting the end of the traditional inpatient-oriented hospital. Those predictions have triggered a scramble by many hospital managers to adapt their organizations and empty beds to the expected predominance of same-day services. One Minnesota facility that surveyed the outpatient trend, however, found that its strategic options weren't limited to becoming a jumbo-sized outpatient clinic, explain David Allen, a partner with The Chancellor Group, Bloomington, Minn., and Daniel Weber, vice president of Fairview Southdale Hospital, Edina, Minn., in this special report. By understanding the multidimensional nature of ambulatory services and focusing its efforts on becoming a regional hub of healthcare services, Fairview Southdale has carved its own niche in a changing provider market.

Removal of traces of toluene and p-xylene in indoor air using biofiltration and a hybrid system (biofiltration + adsorption).

PubMed

Luengas, Angela Tatiana; Hort, Cécile; Platel, Vincent; Elias, Ana; Barona, Astrid; Moynault, Laurent

2017-04-01

Biofiltration technology and the hybrid system combining biofiltration and adsorption (onto activated carbon) were compared as possible methods to toluene and p-xylene at parts per million concentration levels (2-45 and 1-33 ppb, respectively). An organic material was used as packing material for the biofiltration process. Even at low empty bed residence times (EBRTs) and concentrations, toluene removal efficiency reached 100% and p-xylene showed an increasing trend on their removal efficiency over the time using biofiltration. The assessment of by-products and particle generation by the biofilter and the hybrid system were taken into account. Acetone and acetic acid were identified as by-products of the biofilter. Particle emissions in the range of 0.03 to 10 μm were recorded for both systems.

The fluidized bed separator

NASA Astrophysics Data System (ADS)

Sharapov, R. R.; Kharlamov, E. V.; Yadykina, V. V.

2018-03-01

In the production of building materials produces a large amount of harmful substances, poisoning atmosphere and adjacent to the building materials site. One of the biggest polluting the ecology of cities adjacent to industry, is metallurgical industry. One of the most important technological processes is the enrichment, in which the rocks are extracted empty components. In the enrichment of iron ore in the production an increasing proportion consist the anthropogenic waste industries, which pollute the air basin and the huge territory around the factories that dumped these same wastes. This reduces as a space for human life and for the functioning and development of cities. These materials can be applied as construction materials, for example, in the preparation of fine-grained concrete as a mineral powder, and these materials can be applied in the construction of roads, housing, for receiving paint etc.

Absorption and retention of nickel from drinking water in relation to food intake and nickel sensitivity.

PubMed

Nielsen, G D; Søderberg, U; Jørgensen, P J; Templeton, D M; Rasmussen, S N; Andersen, K E; Grandjean, P

1999-01-01

Two studies were performed to examine the influence of fasting and food intake on the absorption and retention of nickel added to drinking water and to determine if nickel sensitization played any role in this regard. First, eight nonallergic male volunteers fasted overnight before being given nickel in drinking water (12 micrograms Ni/kg) and, at different time intervals, standardized 1400-kJ portions of scrambled eggs. When nickel was ingested in water 30 min or 1 h prior to the meal, peak nickel concentrations in serum occurred 1 h after the water intake, and the peak was 13-fold higher than the one seen 1 h after simultaneous intake of nickel-containing water and scrambled eggs. In the latter case, a smaller, delayed peak occurred 3 h after the meal. Median urinary nickel excretion half-times varied between 19.9 and 26.7 h. Within 3 days, the amount of nickel excreted corresponded to 2.5% of the nickel ingested when it was mixed into the scrambled eggs. Increasing amounts were excreted as the interval between the water and the meal increased, with 25.8% of the administered dose being excreted when the eggs were served 4 h prior to the nickel-containing drinking water. In the second experiment, a stable nickel isotope, 61Ni, was given in drinking water to 20 nickel-sensitized women and 20 age-matched controls, both groups having vesicular hand eczema of the pompholyx type. Nine of 20 nickel allergic eczema patients experienced aggravation of hand eczema after nickel administration, and three also developed a maculopapular exanthema. No exacerbation was seen in the control group. The course of nickel absorption and excretion in the allergic groups did not differ and was similar to the pattern seen in the first study, although the absorption in the women was less. A sex-related difference in gastric emptying rates may play a role. Thus, food intake and gastric emptying are of substantial significance for the bioavailability of nickel from aqueous solutions. Copyright 1999 Academic Press.

What is emptiness? Clarifying the 7th criterion for borderline personality disorder.

PubMed

Klonsky, E David

2008-08-01

The present study aims to clarify the 7th DSM-IV criterion for Borderline Personality Disorder: "chronic feelings of emptiness." Emptiness has been the subject of little empirical investigation. The relationship of emptiness to boredom and other affect-states is uncertain, and patients and clinicians can find it difficult to generate verbal descriptions of emptiness. In the present study, two sets of analyses address the meaning and clinical implications of feeling empty. First, affect-states that co-occur with emptiness are identified in 45 young adults who exhibit a prominent feature of Borderline Personality Disorder (i.e., self-injury). Second, the relationship of chronic emptiness to key psychiatric variables is examined in a large nonclinical sample (n = 274). Results indicate that emptiness is negligibly related to boredom, is closely related to feeling hopeless, lonely, and isolated, and is a robust predictor of depression and suicidal ideation (but not anxiety or suicide attempts). Findings are consistent with DSM-IV revisions regarding the 7th criterion for Borderline Personality Disorder. In addition, findings suggest that emptiness reflects pathologically low positive affect and significant psychiatric distress.

Nothing to it: Precursors to a Zero Concept in Preschoolers

PubMed Central

Merritt, Dustin J.; Brannon, Elizabeth M.

2013-01-01

Do young children understand the numerical value of empty sets prior to developing a concept of symbolic zero? Are empty sets represented as mental magnitudes? In order to investigate these questions, we tested 4-year old children and adults with a numerical ordering task in which the goal was to select two stimuli in ascending numerical order with occasional empty set stimuli. Both children and adults showed distance effects for empty sets.. Children who were unable to order the symbol zero (e.g., 0 < 1), but who successfully ordered countable integers (e.g., 2 < 4) nevertheless showed distance effects with empty sets. These results suggest that empty sets are represented on the same numerical continuum as non-empty sets and that children represent empty sets numerically prior to understanding symbolic zero. PMID:23219980

Gastric emptying abnormal in duodenal ulcer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Holt, S.; Heading, R.C.; Taylor, T.V.

1986-07-01

To investigate the possibility that an abnormality of gastric emptying exists in duodenal ulcer and to determine if such an abnormality persists after ulcer healing, scintigraphic gastric emptying measurements were undertaken in 16 duodenal ulcer patients before, during, and after therapy with cimetidine; in 12 patients with pernicious anemia, and in 12 control subjects. No difference was detected in the rate or pattern of gastric emptying in duodenal ulcer patients before and after ulcer healing with cimetidine compared with controls, but emptying of the solid component of the test meal was more rapid during treatment with the drug. Comparison ofmore » emptying patterns obtained in duodenal ulcer subjects during and after cimetidine treatment with those obtained in pernicious anemia patients and controls revealed a similar relationship that was characterized by a tendency for reduction in the normal differentiation between the emptying of solid and liquid from the stomach. The similarity in emptying patterns in these groups of subjects suggests that gastric emptying of solids may be influenced by changes in the volume of gastric secretion. The failure to detect an abnormality of gastric emptying in duodenal ulcer subjects before and after ulcer healing calls into question the widespread belief that abnormally rapid gastric emptying is a feature with pathogenetic significance in duodenal ulcer disease.« less

Physical characteristics of indigestible solids affect emptying from the fasting human stomach.

PubMed Central

Meyer, B; Beglinger, C; Neumayer, M; Stalder, G A

1989-01-01

Gastric emptying of indigestible solids depends on their size. It is not clear whether physical characteristics other than particle size affect emptying of indigestible solids from the fasting human stomach. We studied gastric emptying of three differently shaped particles, (cubes, spheres, rods) of either hard or soft consistency during the fasting state in human volunteers. The shape of indigestible particles did not affect their emptying. The area under the gastric emptying curve (AUC: particles x hour) was for hard cubes 24.7 (2.2), for hard spheres 27.9 (1.6), for hard rods 26.9 (2.7). All soft particles emptied faster than their identically shaped hard counterparts, but there was no difference among the three shapes (AUC for soft cubes: 29.2 (3.0), for soft spheres 32.0 (1.8), for soft rods 34.1 (1.2). If gastric emptying of hard and soft particles was compared independently of their shape, soft particles emptied significantly faster than hard ones: AUC 31.8 (1.2) v 26.5 (1.3) (p less than 0.01). In conclusion, the consistency but not the shape significantly affects gastric emptying. Specific physical characteristics other than size and shape may affect gastric emptying of indigestible particles which may be of importance in the design of drugs. PMID:2599438

Gastric emptying of solid radiopaque markers: studies in healthy subjects and diabetic patients.

PubMed

Feldman, M; Smith, H J; Simon, T R

1984-10-01

The purpose of these studies was to develop a radiologic method for assessing gastric emptying of an indigestible solid in humans and to apply this technique to the evaluation of patients with diabetes mellitus. Thirty healthy subjects ingested 10 solid radiopaque markers (small pieces of nasogastric tubing) together with a standard meal (donuts and 7-Up). Radiographs of the upper abdomen were obtained hourly for up to 6 h until all markers had emptied from the stomach. Although most of the liquid component of the meal, labeled with 111In, emptied during the first hour (as assessed simultaneously by radionuclide scintigraphy), few radiopaque markers emptied from the stomach during the first 2 h after the meal. Most markers emptied during the fourth postprandial hour, and all 10 markers had emptied by 6 h in 45 of 46 experiments. In contrast, not all of the solid radiopaque markers emptied from the stomach by 6 h in 16 of 26 experiments in patients with diabetes mellitus (p less than 0.001 vs. healthy controls). In some experiments, 99mTc-labeled scrambled eggs were added to the meal so that emptying of this digestible solid, assessed by scintigraphy, could be compared with emptying of liquids and solid radiopaque markers. In healthy subjects, the digestible solid emptied more slowly than the liquid (t 1/2 = 154 +/- 11 min vs. 30 +/- 3 min, p less than 0.001), but emptying of digestible solid was significantly faster than the emptying of the indigestible solid radiopaque markers. In diabetics, emptying rates for the digestible solid and liquid were close to normal (t 1/2 = 178 +/- 5 min and 40 +/- 3 min, respectively), whereas indigestible solid markers were retained in the stomach 6 h after the meal in 50% of the patients. Radiopaque markers proved to be a simple method for measuring gastric emptying of indigestible solids in humans. Using this technique, patients with insulin-dependent diabetes mellitus had a high incidence of abnormally slow gastric emptying of indigestible solids; the method may be a more sensitive indicator of gastric motor dysfunction than radionuclide scintigraphy.

Flow-through pretreatment of lignocellulosic biomass with inorganic nanoporous membranes

DOEpatents

Bhave, Ramesh R.; Lynd, Lee; Shao, Xiongjun

2018-04-03

A process for the pretreatment of lignocellulosic biomass is provided. The process generally includes flowing water through a pretreatment reactor containing a bed of particulate ligno-cellulosic biomass to produce a pressurized, high-temperature hydrolyzate exit stream, separating solubilized compounds from the hydrolyzate exit stream using an inorganic nanoporous membrane element, fractionating the retentate enriched in solubilized organic components and recycling the permeate to the pretreatment reactor. The pretreatment process provides solubilized organics in concentrated form for the subsequent conversion into biofuels and other chemicals.

A review of methods for assessment of the rate of gastric emptying in the dog and cat: 1898-2002.

PubMed

Wyse, C A; McLellan, J; Dickie, A M; Sutton, D G M; Preston, T; Yam, P S

2003-01-01

Gastric emptying is the process by which food is delivered to the small intestine at a rate and in a form that optimizes intestinal absorption of nutrients. The rate of gastric emptying is subject to alteration by physiological, pharmacological, and pathological conditions. Gastric emptying of solids is of greater clinical significance because disordered gastric emptying rarely is detectable in the liquid phase. Imaging techniques have the disadvantage of requiring restraint of the animal and access to expensive equipment. Radiographic methods require administration of test meals that are not similar to food. Scintigraphy is the gold standard method for assessment of gastric emptying but requires administration of a radioisotope. Magnetic resonance imaging has not yet been applied for assessment of gastric emptying in small animals. Ultrasonography is a potentially useful, but subjective, method for assessment of gastric emptying in dogs. Gastric tracer methods require insertion of gastric or intestinal cannulae and are rarely applied outside of the research laboratory. The paracetamol absorption test has been applied for assessment of liquid phase gastric emptying in the dog, but requires IV cannulation. The gastric emptying breath test is a noninvasive method for assessment of gastric emptying that has been applied in dogs and cats. This method can be carried out away from the veterinary hospital, but the effects of physiological and pathological abnormalities on the test are not known. Advances in technology will facilitate the development of reliable methods for assessment of gastric emptying in small animals.

Community point distribution of insecticide-treated bed nets and community health worker hang-up visits in rural Zambia: a decision-focused evaluation.

PubMed

Wang, Paul; Connor, Alison L; Joudeh, Ammar S; Steinberg, Jeffrey; Ndhlovu, Ketty; Siyolwe, Musanda; Ntebeka, Bristol; Chibuye, Benjamin; Hamainza, Busiku

2016-03-03

In 2013, the Zambian Ministry of Health through its National Malaria Control Programme distributed over two million insecticide-treated bed nets (ITNs) in four provinces using a door-to-door distribution strategy, and more than 6 million ITNs were allocated to be distributed in 2014. This study was commissioned to measure attendance rates at a community point distribution and to examine the impact of follow-up community health worker (CHW) hang-up visits on short and medium-term ITN retention and usage with a view of informing optimal ITN distribution strategy in Zambia. Households received ITNs at community point distributions conducted in three rural communities in Rufunsa District, Zambia. Households were then randomly allocated into five groups to receive CHW visits to hang any unhung ITNs at different intervals: 1-3, 5-7, 10-12, 15-17 days, and no hang-up visit. Follow-up surveys were conducted among all households at 7-11 weeks after distribution and at 5-6 months after distribution to measure short- and medium-term household retention and usage of ITNs. Of the 560 pre-registered households, 540 (96.4 %) attended the community point distribution. Self-installation of ITNs by households increased over the first 10 days after the community point distribution. Retention levels remained high over time with 90.2 % of distributed ITNs still in the household at 7-11 weeks and 85.7 % at 5-6 months. Retention did not differ between households that received a CHW visit and those that did not. At 7-11 weeks, households had an average of 73.8 % of sleeping spaces covered compared to 80.3 % at 5-6 months. On average, 65.6 % of distributed ITNs were hanging at 7-11 weeks compared to 63.1 % at 5-6 months. While a CHW hang-up visit was associated with increased usage at 7-11 weeks, this difference was no longer apparent at 5-6 months. This evaluation revealed that (1) the community point distributions achieved high attendance rates followed by acceptable rates of short-term and medium-term ITN retention and usage, as compared to reported rates achieved by door-to-door distributions in the recent past, (2) CHW hang-up visits had a modest short-term impact on ITN usage but no medium-term effect, and (3) community point distributions can yield sizeable time savings compared to door-to-door distributions.

Application of a combined process of moving-bed biofilm reactor (MBBR) and chemical coagulation for dyeing wastewater treatment.

PubMed

Shin, D H; Shin, W S; Kim, Y H; Han, Myung Ho; Choi, S J

2006-01-01

A combined process consisted of a Moving-Bed Biofilm Reactor (MBBR) and chemical coagulation was investigated for textile wastewater treatment. The pilot scale MBBR system is composed of three MBBRs (anaerobic, aerobic-1 and aerobic-2 in series), each reactor was filled with 20% (v/v) of polyurethane-activated carbon (PU-AC) carrier for biological treatment followed by chemical coagulation with FeCl2. ln the MBBR process, 85% of COD and 70% of color (influent COD = 807.5 mg/L and color = 3,400 PtCo unit) were removed using relatively low MLSS concentration and short hydraulic retention time (HRT = 44 hr). The biologically treated dyeing wastewater was subjected to chemical coagulation. After coagulation with FeCl2, 95% of COD and 97% of color were removed overall. The combined process of MBBR and chemical coagulation has promising potential for dyeing wastewater treatment.

Optimization of an integrated sponge--granular activated carbon fluidized bed bioreactor as pretreatment to microfiltration in wastewater reuse.

PubMed

Xing, W; Ngo, H H; Guo, W S; Listowski, A; Cullum, P

2012-06-01

A specific integrated fluidized bed bioreactor (iFBBR) was optimized in terms of organic loading rate (OLR), hydraulic retention time (HRT) and frequency of new sustainable flocculant (NSBF) addition for primary treated sewage effluent (PTSE) treatment. It was observed that iFBBR achieved the best performance with the operating conditions of 4 times/day NSBF addition, HRT of 90 min and OLR of 8.64 kg COD/day m(3). The removal efficiencies were found to be more than 93% of dissolved organic carbon (DOC), 61% of total nitrogen (T-N) and 60% of total phosphorus (T-P). iFBBR as pretreatment of submerged microfiltration (SMF) is successful in increasing the critical flux and reducing the membrane fouling. NSBF-iFBBR-SMF hybrid system led to very high organic removal efficiency with an average DOC removal of 97% from synthetic PTSE. Copyright © 2012 Elsevier Ltd. All rights reserved.

Physicochemical characteristics and microbial community evolution of biofilms during the start-up period in a moving bed biofilm reactor.

PubMed

Zhu, Yan; Zhang, Yan; Ren, Hong-Qiang; Geng, Jin-Ju; Xu, Ke; Huang, Hui; Ding, Li-Li

2015-03-01

This study aimed to investigate biofilm properties evolution coupled with different ages during the start-up period in a moving bed biofilm reactor system. Physicochemical characteristics including adhesion force, extracellular polymeric substances (EPS), morphology as well as volatile solid and microbial community were studied. Results showed that the formation and development of biofilms exhibited four stages, including (I) initial attachment and young biofilm formation, (II) biofilms accumulation, (III) biofilm sloughing and updating, and (IV) biofilm maturation. During the whole start-up period, adhesion force was positively and significantly correlated with the contents of EPS, especially the content of polysaccharide. In addition, increased adhesion force and EPS were beneficial for biofilm retention. Gram-negative bacteria mainly including Sphaerotilus, Zoogloea and Haliscomenobacter were predominant in the initial stage. Actinobacteria was beneficial to resist sloughing. Furthermore, filamentous bacteria were dominant in maturation biofilm. Copyright © 2015 Elsevier Ltd. All rights reserved.

Influence of nitrate, sulfate and operational parameters on the bioreduction of perchlorate using an up-flow packed bed reactor at high salinity.

PubMed

Chung, J; Shin, S; Oh, J

2010-05-01

In this study we have investigated whether electron acceptors, such as nitrate or sulphate ions, competitively inhibit the reduction of perchlorate in brine in continuous up-flow packed bed bioreactors. The effect of pH and hydraulic retention time (HRT) on the reduction of perchlorate at high salinity has also been examined. Reduction of perchlorate was found to be only moderately influenced by nitrate (under 163 mg N L-'), implying that there was no significant microbial competition for electron acceptors. As a result of microbial diversity, there were few differences between microbial communities fed with a variety of media, suggesting that most nitrate-reducing bacteria are able to reduce perchlorate at high salinity. Reduction of perchlorate was almost complete at relatively high sulfate levels (1000 mg L(-1)), neutral pH (6-8) and relatively long HRTs (> 10 h).

Synthesis of Biodiesel in Batch and Packed-Bed Reactors Using Powdered and Granular Sugar Catalyst

NASA Astrophysics Data System (ADS)

Janaun, J.; Lim, P. M.; Balan, W. S.; Yaser, A. Z.; Chong, K. P.

2017-06-01

Increasing world production of palm oil warrants effective utilization of its waste. In particular, conversion of waste cooking oil into biodiesel has obtained global interest because of renewable energy need and reduction of CO2 emission. In this study, oleic acid used as a model compound for waste cooking oil conversion using esterification reaction catalysed by sugar catalyst (SC) in powdered (P-SC) and granular (G-SC) forms. The catalysts were synthesized via incomplete carbonization of D-glucose followed by functionalization with concentrated sulphuric acid. Catalysts characterizations were done for their physical and chemical properties using modern tools. Batch and packed-bed reactor systems were used to evaluate the reactivity of the catalysts. The results showed that G-SC had slightly higher total acidity and more porous than P-SC. The experimental conditions for batch reaction were temperature of 60°C, molar ratio of 1:20 (Oleic Acid:Methanol) and 2 wt. catalyst with respect to oleic acid. The results showed the maximum oleic acid conversion using G-SC and P-SC were 52 and 48, respectively. Whereas, the continuous reaction with varying feed flow rate as a function of retention time was studied by using 3 g of P-SC in 60 °C and 1:20 molar ratio in a packed-bed reactor. The results showed that a longer retention time which was 6.48 min and feed flow rate 1.38 ml/min, achieved higher average conversion of 9.9 and decreased with further increasing flow rate. G-SC showed a better average conversion of 10.8 at lowest feed flow rate of 1.38 ml/min in continuous reaction experiments. In a broader perspective, large scale continuous biodiesel production is feasible using granular over powdered catalyst mainly due to it lower pressure drop.

RELATIONSHIP BETWEEN GLYCEMIC CONTROL AND GASTRIC EMPTYING IN POORLY CONTROLLED TYPE 2 DIABETES

PubMed Central

Bharucha, Adil E.; Kudva, Yogish; Basu, Ananda; Camilleri, Michael; Low, Phillip A.; Vella, Adrian; Zinsmeister, Alan R.

2014-01-01

Background & Aims Acute hyperglycemia delays gastric emptying in patients with diabetes. However, it is not clear whether improved control of glycemia affects gastric emptying in these patients. We investigated whether overnight and short-term (6 months) improvements in control of glycemia affect gastric emptying. Methods We studied 30 patients with poorly controlled type 2 diabetes (levels of glycated hemoglobin >9%). We measured gastric emptying using the [13C]-spirulina platensis breath test on the patients’ first visit (visit 1), after overnight administration of insulin or saline, 1 week later (visit 2), and 6 months after intensive therapy for diabetes. We also measured fasting and post-prandial plasma levels of C-peptide, GLP1, and amylin, as well as autonomic functions. Results At visit 1, gastric emptying was normal in 10 patients, delayed in 14, and accelerated in 6; 6 patients had gastrointestinal symptoms; vagal dysfunction was associated with delayed gastric emptying (P<.05). Higher fasting blood levels of glucose were associated with shorter half-times of gastric emptying (thalf) at visits 1 (r= −0.46, P=.01) and 2 (r= −0.43, P=.02). Although blood levels of glucose were lower after administration of insulin (132±7 mg/dl) than saline (211±15 mg/dl; P=0.0002), gastric emptying thalf was not lower after administration of insulin, compared with saline. After 6 months of intensive therapy, levels of glycated hemoglobin decreased from 10.6%±0.3% to 9%±0.4% (P=.0003), but gastric emptying thalf did not change (92±8 min before, 92±7 min after). Gastric emptying did not correlate with plasma levels of GLP1 and amylin. Conclusions Two-thirds of patients with poorly-controlled type 2 diabetes have mostly asymptomatic yet abnormal gastric emptying. Higher fasting blood levels of glucose are associated with faster gastric emptying. Overnight and sustained (6 months) improvements in glycemic control do not affect gastric emptying. PMID:25041866

Controlled dexamethasone delivery via double-walled microspheres to enhance long-term adipose tissue retention

PubMed Central

Kelmendi-Doko, Arta; Rubin, J Peter; Klett, Katarina; Mahoney, Christopher; Wang, Sheri; Marra, Kacey G

2017-01-01

Current materials used for adipose tissue reconstruction have critical shortcomings such as suboptimal volume retention, donor-site morbidity, and poor biocompatibility. The aim of this study was to examine a controlled delivery system of dexamethasone to generate stable adipose tissue when mixed with disaggregated human fat in an athymic mouse model for 6 months. The hypothesis that the continued release of dexamethasone from polymeric microspheres would enhance both adipogenesis and angiogenesis more significantly when compared to the single-walled microsphere model, resulting in long-term adipose volume retention, was tested. Dexamethasone was encapsulated within single-walled poly(lactic-co-glycolic acid) microspheres (Dex SW MS) and compared to dexamethasone encapsulated in a poly(lactic-co-glycolic acid) core surrounded by a shell of poly-l-lactide. The double-walled polymer microsphere system in the second model was developed to create a more sustainable drug delivery process. Dexamethasone-loaded poly(lactic-co-glycolic acid) microspheres (Dex SW MS) and dexamethasone-loaded poly(lactic-co-glycolic acid)/poly-l-lactide double-walled microspheres (Dex DW MS) were prepared using single and double emulsion/solvent techniques. In vitro release kinetics were determined. Two doses of each type of microsphere were examined; 50 and 27 mg of Dex MS and Dex DW MS were mixed with 0.3 mL of human lipoaspirate. Additionally, 50 mg of empty MS and lipoaspirate-only controls were examined. Samples were analyzed grossly and histologically after 6 months in vivo. Mass and volume were measured; dexamethasone microsphere-containing samples demonstrated greater adipose tissue retention compared to the control group. Histological analysis, including hematoxylin and eosin and CD31 staining, indicated increased vascularization (p < 0.05) within the Dex MS-containing samples. Controlled delivery of adipogenic factors, such as dexamethasone via polymer microspheres, significantly affects adipose tissue retention by maintaining healthy tissue formation and vascularization. Dex DW MS provide an improved model to former Dex SW MS, resulting in notably longer release time and, consequently, larger volumes of adipose retained in vivo. The use of microspheres, specifically double-walled, as vehicles for controlled drug delivery of adipogenic factors therefore present a clinically relevant model of adipose retention that has the potential to greatly improve soft tissue repair. PMID:29051810

Influence of bone marrow-derived mesenchymal stem cells pre-implantation differentiation approach on periodontal regeneration in vivo.

PubMed

Cai, Xinjie; Yang, Fang; Yan, Xiangzhen; Yang, Wanxun; Yu, Na; Oortgiesen, Daniel A W; Wang, Yining; Jansen, John A; Walboomers, X Frank

2015-04-01

The implantation of bone marrow-derived mesenchymal stem cells (MSCs) has previously been shown successful to achieve periodontal regeneration. However, the preferred pre-implantation differentiation strategy (e.g. maintenance of stemness, osteogenic or chondrogenic induction) to obtain optimal periodontal regeneration is still unknown. This in vivo study explored which differentiation approach is most suitable for periodontal regeneration. Mesenchymal stem cells were obtained from Fischer rats and seeded onto poly(lactic-co-glycolic acid)/poly(ɛ-caprolactone) electrospun scaffolds, and then pre-cultured under different in vitro conditions: (i) retention of multilineage differentiation potential; (ii) osteogenic differentiation approach; and (iii) chondrogenic differentiation approach. Subsequently, the cell-scaffold constructs were implanted into experimental periodontal defects of Fischer rats, with empty scaffolds as controls. After 6 weeks of implantation, histomorphometrical analyses were applied to evaluate the regenerated periodontal tissues. The chondrogenic differentiation approach showed regeneration of alveolar bone and ligament tissues. The retention of multilineage differentiation potential supported only ligament regeneration, while the osteogenic differentiation approach boosted alveolar bone regeneration. Chondrogenic differentiation of MSCs before implantation is a useful strategy for regeneration of alveolar bone and periodontal ligament, in the currently used rat model. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Evaluation of an Innovative Over-the-Counter Treatment for Symptoms of Reflux Disease: Quick-Dissolving Alginate Granules

PubMed Central

Strugala, Vicki; Dettmar, Peter W.; Thomas, Edward C. M.

2012-01-01

Traditional antacids and alginate-based reflux suppressants are OTC products commonly used to treat reflux symptoms. There has been a lack of innovation of new formulations in this therapy area despite consumers finding established products unpalatable. Here we evaluate a novel product formulation which takes the form of quick-dissolving alginate granules in single-dose sachets (Gaviscon Direct Powder (GDP)). Market research and taste evaluation confirmed that reflux sufferers considered GDP to have good flavour and taste, no chalky aftertaste and dissolved rapidly in the mouth with 68% noting so within 10 seconds. GDP was considered convenient and easy to use. The consumer-driven product development was also shown to form a strong alginate raft in standardised in vitro conditions that met the specifications of the BP monograph (raft strength > 7.5 g). Gastric retention of GDP and a test meal was investigated in healthy volunteers using gamma scintigraphy in comparison to Liquid Gaviscon. Both products formed an alginate raft in the stomach above the test meal and emptied after the meal. The gastric retention of the GDP product was found to be noninferior to Liquid Gaviscon. In conclusion, the innovative GDP product formed an effective raft and was well liked by consumers. PMID:23320198

Effect of proximal vagotomy and Roux-en-Y diversion on gastric emptying kinetics in asymptomatic patients.

PubMed

Urbain, J L; Penninckx, F; Siegel, J A; Vandenborre, P; Van Cutsem, E; Vandenmaegdenbergh, V; De Roo, M

1990-10-01

The role of the distal stomach in gastric emptying was studied. Ten patients with proximal gastric vagotomy (PV) and 10 age-matched patients with Roux-en-Y gastro-jejunostomy (R-Y) were compared with 10 healthy controls. Gastric emptying of solids and liquids was determined by the use of Tc-99m SC scrambled eggs and In-111 DTPA. In PV, gastric emptying of both solids and liquids was delayed; the prolongation with solids was mainly accounted for by an abnormal lag phase. In R-Y patients, no lag phase was observed, and the solid emptying curve pattern was characterized by early rapid emptying followed by very slow emptying. Both the solid and liquid phases were prolonged. The lag phase is affected by proximal vagotomy and is mainly determined by the distal stomach, which appears to be essential for normal emptying.

Gastric pouch emptying of solid food in patients with successful and unsuccessful weight loss after Roux-en-Y gastric bypass surgery.

PubMed

Deden, Laura N; Cooiman, Mellody I; Aarts, Edo O; Janssen, Ignace M C; Gotthardt, Martin; Hendrickx, Baudewijn W; Berends, Frits J

2017-11-01

After Roux-en-Y gastric bypass (RYGB), approximately 10% of patients have insufficient weight loss (excess body mass index loss<50%). Gastric pouch emptying may have a role in weight loss. To compare pouch emptying of patients with poor weight loss and patients with successful weight loss after RYGB. A research-intensive nonacademic hospital and center of expertise in bariatric surgery in the Netherlands METHODS: Female patients were included from among patients with the least (poor weight loss group [P-WL]) and the most weight loss (successful weight loss group [S-WL]) in our center 2 years after RYGB. Pouch emptying scintigraphy was performed after ingestion of a radiolabeled solid meal. Emptying curves, intestinal content (IC) at meal completion and after 15, 30, 45, and 60 minutes, half emptying time, and maximal pouch emptying rate were compared. Five individuals were included in P-WL and 5 in S-WL, on average 2.5 ± .3 years after RYGB. Total weight loss was 18 ± 4.1% in P-WL and 44 ± 5.7% in S-WL (P<.001). In P-WL, a fast initial pouch emptying and exponential emptying curve was observed, compared with a slower initial emptying and more linear curve in S-WL. Faster emptying in P-WL was also shown by a larger IC meal (42 ± 18% versus 4.0 ± 3.3%,), IC 15 (76 ± 15% versus 35 ± 22%), and IC 30 (85 ± 12% versus 54 ± 25%), and a greater maximal pouch emptying rate (17 ± 4.7 versus 5.6 ± 3.4%/min) compared with S-WL (P<.05). A linear correlation was found between total weight loss and maximal pouch emptying rate (Pearson R = .82, P = .004). Pouch emptying for solid food was faster in patients with the least weight loss compared with patients with the most weight loss after RYGB. If pouch emptying is an important mechanism in weight loss, altering the pouch outlet may improve poor weight loss management. Copyright © 2017 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.

Integrating retention soil filters into urban hydrologic models - Relevant processes and important parameters

NASA Astrophysics Data System (ADS)

Bachmann-Machnik, Anna; Meyer, Daniel; Waldhoff, Axel; Fuchs, Stephan; Dittmer, Ulrich

2018-04-01

Retention Soil Filters (RSFs), a form of vertical flow constructed wetlands specifically designed for combined sewer overflow (CSO) treatment, have proven to be an effective tool to mitigate negative impacts of CSOs on receiving water bodies. Long-term hydrologic simulations are used to predict the emissions from urban drainage systems during planning of stormwater management measures. So far no universally accepted model for RSF simulation exists. When simulating hydraulics and water quality in RSFs, an appropriate level of detail must be chosen for reasonable balancing between model complexity and model handling, considering the model input's level of uncertainty. The most crucial parameters determining the resultant uncertainties of the integrated sewer system and filter bed model were identified by evaluating a virtual drainage system with a Retention Soil Filter for CSO treatment. To determine reasonable parameter ranges for RSF simulations, data of 207 events from six full-scale RSF plants in Germany were analyzed. Data evaluation shows that even though different plants with varying loading and operation modes were examined, a simple model is sufficient to assess relevant suspended solids (SS), chemical oxygen demand (COD) and NH4 emissions from RSFs. Two conceptual RSF models with different degrees of complexity were assessed. These models were developed based on evaluation of data from full scale RSF plants and column experiments. Incorporated model processes are ammonium adsorption in the filter layer and degradation during subsequent dry weather period, filtration of SS and particulate COD (XCOD) to a constant background concentration and removal of solute COD (SCOD) by a constant removal rate during filter passage as well as sedimentation of SS and XCOD in the filter overflow. XCOD, SS and ammonium loads as well as ammonium concentration peaks are discharged primarily via RSF overflow not passing through the filter bed. Uncertainties of the integrated simulation of the sewer system and RSF model mainly originate from the model parameters of the hydrologic sewer system model.

Differences in flooding tolerance between species from two wetland habitats with contrasting hydrology: implications for vegetation development in future floodwater retention areas.

PubMed

Banach, Katarzyna; Banach, Artur M; Lamers, Leon P M; De Kroon, Hans; Bennicelli, Riccardo P; Smits, Antoine J M; Visser, Eric J W

2009-01-01

Plants need different survival strategies in habitats differing in hydrological regimes. This probably has consequences for vegetation development when former floodplain areas that are currently confronted with soil flooding only, will be reconnected to the highly dynamical river bed. Such changes in river management are increasingly important, especially at locations where increased water retention can prevent flooding events in developed areas. It is therefore crucial to determine the responses of plant species from relatively low-dynamic wetlands to complete submergence, and to compare these with those of species from river forelands, in order to find out what the effects of such landscape-scale changes on vegetation would be. To compare the species' tolerance to complete submergence and their acclimation patterns, a greenhouse experiment was designed with a selection of 19 species from two contrasting sites: permanently wet meadows in a former river foreland, and frequently submerged grasslands in a current river foreland. The plants were treated with short (3 weeks) and long (6 weeks) periods of complete submergence, to evaluate if survival, morphological responses, and changes in biomass differed between species of the two habitats. All tested species inhabiting river forelands were classified as tolerant to complete submergence, whereas species from wet meadows showed either relatively intolerant, intermediate or tolerant responses. Species from floodplains showed in all treatments stronger shoot elongation, as well as higher production of biomass of leaves, stems, fine roots and taproots, compared with meadow species. There is a strong need for the creation of temporary water retention basins during high levels of river discharge. However, based on the data presented, it is concluded that such reconnection of former wetlands (currently serving as meadows) to the main river bed will strongly influence plant species composition and abundance.

Evaluation of mixed valent iron oxides as reactive adsorbents for arsenic removal.

PubMed

Mishra, Dhananjay; Farrell, James

2005-12-15

The objective of this research was to determine if Fe(II)-bearing iron oxides generate ferric hydroxides at sufficient rates for removing low levels of arsenic in packed-bed reactors, while at the same time avoiding excessive oxide production that contributes to bed clogging in oxygenated waters. Column experiments were performed to determine the effectiveness of three media for arsenic removal over a range in empty bed contact times, influent arsenic concentrations, dissolved oxygen (DO) levels, and solution pH values. Corrosion rates of the media as a function of the water composition were determined using batch and electrochemical methods. Rates of arsenic removal were first order in the As(V) concentration and were greater for media with higher corrosion rates. As(V) removal increased with increasing DO levels primarily due to faster oxidation of the Fe2+ released by media corrosion. To obtain measurable amounts of arsenic removal in 15 mM NaCl electrolyte solutions containing 50 microg/L As(V), the rate of Fe2+ released by the media needed to be at least 15 times greater than the As(V) feed rate into the column. In waters containing 30 mg/L of silica and 50 microg/L of As(V), measurable amounts of arsenic removal were obtained only for Fe2+ release rates that were at least 200 times greater than the As(V) feed rate. Although all columns showed losses in hydraulic conductivity overthe course of 90 days of operation, the conductivity values remained high, and the losses could be reversed by backwashing the media. The reaction products produced by the media in domestic tap water had average As-to-Fe ratios that were approximately 25% higher than those for a commercially available adsorbent.

Impact on mortality of prompt admission to critical care for deteriorating ward patients: an instrumental variable analysis using critical care bed strain.

PubMed

Harris, Steve; Singer, Mervyn; Sanderson, Colin; Grieve, Richard; Harrison, David; Rowan, Kathryn

2018-05-07

To estimate the effect of prompt admission to critical care on mortality for deteriorating ward patients. We performed a prospective cohort study of consecutive ward patients assessed for critical care. Prompt admissions (within 4 h of assessment) were compared to a 'watchful waiting' cohort. We used critical care strain (bed occupancy) as a natural randomisation event that would predict prompt transfer to critical care. Strain was classified as low, medium or high (2+, 1 or 0 empty beds). This instrumental variable (IV) analysis was repeated for the subgroup of referrals with a recommendation for critical care once assessed. Risk-adjusted 90-day survival models were also constructed. A total of 12,380 patients from 48 hospitals were available for analysis. There were 2411 (19%) prompt admissions (median delay 1 h, IQR 1-2) and 9969 (81%) controls; 1990 (20%) controls were admitted later (median delay 11 h, IQR 6-26). Prompt admissions were less frequent (p < 0.0001) as strain increased from low (22%), to medium (15%) to high (9%); the median delay to admission was 3, 4 and 5 h respectively. In the IV analysis, prompt admission reduced 90-day mortality by 7.4% (95% CI 1.7-18.5%, p = 0.117) overall, and 16.2% (95% CI 1.1-31.3%, p = 0.036) for those recommended for critical care. In the risk-adjust survival model, 90-day mortality was similar. After allowing for unobserved prognostic differences between the groups, we find that prompt admission to critical care leads to lower 90-day mortality for patients assessed and recommended to critical care.

Agoraphobia and Melancholia: Thoughts on Milrod's "Emptiness in Agoraphobia Patients".

PubMed

Yates, Sheena

2015-08-01

Milrod (2007) identifies persistent emptiness in agoraphobic patients whose symptoms of anxiety and avoidance have remitted. To this important identification, a number of critical considerations may be raised regarding the meanings of emptiness in the psychoanalytic clinic. Milrod's admonishment to distinguish between an emptiness that indicates a deficit in the structure and stability of self-representation, and an emptiness that is strictly defensive, is a case in point. While much of the literature supports an interpretation of emptiness as a defense against overwhelming rage, these patients' assertions and experiences of emptiness can be better explained by the presence of traumatic, unmourned losses. Several explanations are offered as to why agoraphobic patients, in particular, defend unconsciously against mourning. © 2015 by the American Psychoanalytic Association.

Current Development in Treatment and Hydrogen Energy Conversion of Organic Solid Waste

NASA Astrophysics Data System (ADS)

Shin, Hang-Sik

2008-02-01

This manuscript summarized current developments on continuous hydrogen production technologies researched in Korea advanced institute of science and technology (KAIST). Long-term continuous pilot-scale operation of hydrogen producing processes fed with non-sterile food waste exhibited successful results. Experimental findings obtained by the optimization processes of growth environments for hydrogen producing bacteria, the development of high-rate hydrogen producing strategies, and the feasibility tests for real field application could contribute to the progress of fermentative hydrogen production technologies. Three major technologies such as controlling dilution rate depending on the progress of acidogenesis, maintaining solid retention time independently from hydraulic retention time, and decreasing hydrogen partial pressure by carbon dioxide sparging could enhance hydrogen production using anaerobic leaching beds reactors and anaerobic sequencing batch reactors. These findings could contribute to stable, reliable and effective performances of pilot-scale reactors treating organic wastes.

Neural fuzzy modelization of copper removal from water by biosorption in fixed-bed columns using olive stone and pinion shell.

PubMed

Calero, M; Iáñez-Rodríguez, I; Pérez, A; Martín-Lara, M A; Blázquez, G

2018-03-01

Continuous copper biosorption in fixed-bed column by olive stone and pinion shell was studied. The effect of three operational parameters was analyzed: feed flow rate (2-6 ml/min), inlet copper concentration (40-100 mg/L) and bed-height (4.4-13.4 cm). Artificial Neural-Fuzzy Inference System (ANFIS) was used in order to optimize the percentage of copper removal and the retention capacity in the column. The highest percentage of copper retained was achieved at 2 ml/min, 40 mg/L and 4.4 cm. However, the optimum biosorption capacity was obtained at 6 ml/min, 100 mg/L and 13.4 cm. Finally, breakthrough curves were simulated with mathematical traditional models and ANFIS model. The calculated results obtained with each model were compared with experimental data. The best results were given by ANFIS modelling that predicted copper biosorption with high accuracy. Breakthrough curves surfaces, which enable the visualization of the behavior of the system in different process conditions, were represented. Copyright © 2017 Elsevier Ltd. All rights reserved.

Hydrogeomorphology of the hyporheic zone: stream solute and fine particle interactions with a dynamic streambed

USGS Publications Warehouse

Harvey, J.W.; Drummond, J.D.; Martin, R.L.; McPhillips, L.E.; Packman, A.I.; Jerolmack, D.J.; Stonedahl, S.H.; Aubeneau, A.F.; Sawyer, A.H.; Larsen, L.G.; Tobias, C.R.

2012-01-01

Hyporheic flow in streams has typically been studied separately from geomorphic processes. We investigated interactions between bed mobility and dynamic hyporheic storage of solutes and fine particles in a sand-bed stream before, during, and after a flood. A conservatively transported solute tracer (bromide) and a fine particles tracer (5 μm latex particles), a surrogate for fine particulate organic matter, were co-injected during base flow. The tracers were differentially stored, with fine particles penetrating more shallowly in hyporheic flow and retained more efficiently due to the high rate of particle filtration in bed sediment compared to solute. Tracer injections lasted 3.5 h after which we released a small flood from an upstream dam one hour later. Due to shallower storage in the bed, fine particles were rapidly entrained during the rising limb of the flood hydrograph. Rather than being flushed by the flood, we observed that solutes were stored longer due to expansion of hyporheic flow paths beneath the temporarily enlarged bedforms. Three important timescales determined the fate of solutes and fine particles: (1) flood duration, (2) relaxation time of flood-enlarged bedforms back to base flow dimensions, and (3) resulting adjustments and lag times of hyporheic flow. Recurrent transitions between these timescales explain why we observed a peak accumulation of natural particulate organic matter between 2 and 4 cm deep in the bed, i.e., below the scour layer of mobile bedforms but above the maximum depth of particle filtration in hyporheic flow paths. Thus, physical interactions between bed mobility and hyporheic transport influence how organic matter is stored in the bed and how long it is retained, which affects decomposition rate and metabolism of this southeastern Coastal Plain stream. In summary we found that dynamic interactions between hyporheic flow, bed mobility, and flow variation had strong but differential influences on base flow retention and flood mobilization of solutes and fine particulates. These hydrogeomorphic relationships have implications for microbial respiration of organic matter, carbon and nutrient cycling, and fate of contaminants in streams.

Measurement of gastric emptying by intragastric gamma scintigraphy.

PubMed

Malbert, C H; Mathis, C; Bobillier, E; Laplace, J P; Horowitz, M

1997-09-01

Gastric emptying is usually measured in animals and humans by dilution/sampling or external scintigraphy. These methods are either time consuming or require expensive equipment. The capacity of a miniature gamma counter positioned in the stomach to measure emptying of liquid and solid meals was evaluated. In eight conscious pigs fitted with gastric and duodenal cannulae, gastric emptying of saline (500 mL), dextrose (20%, 500 mL), porridge (300 g) and scrambled eggs (300 g), all labelled with 3.5 MBq 99mTC, was evaluated. When positioned in the antrum the probe was unable to quantify gastric emptying. In contrast, measurements of the fractional emptying of saline over 4-min periods by the probe positioned in the corpus and quantification of radioactivity in the duodenal effluent correlated closely (r = 0.88, P < 0.05). Gastric emptying (50% emptying time) of saline and both solid meals measured by the probe was not significantly different from quantification of the duodenal effluent volume. No difference was observed also for the dextrose meal but only while gastric acid secretion was suppressed by omeprazole. We conclude that an intragastric gamma counter permits measurement of gastric emptying of homogeneous meals provided meal stimulation of gastric secretion was not extensive. This was possible probably by monitoring emptying from the proximal stomach.

Pretreatment of aqueous ammonia on oil palm empty fruit fiber (OPEFB) in production of sugar

NASA Astrophysics Data System (ADS)

Zulkiple, Nursyafiqah; Maskat, Mohamad Yusof; Hassan, Osman

2015-09-01

Oil Palm Empty Fruit Bunch (OPEFB) is an agricultural residue that has the potential to become a good source for renewable feedstock for production of sugar. This work evaluated the effectiveness of aqueous ammonia as pretreatment at low (soaking, SAA) and elevated temperature (pressurized chamber) to deconstruct the lignocellulosic feedstock, prior to enzymatic hydrolysis. The ammonia pretreatments were compared against the standard NaOH method. The best tested pressurized chamber method conditions were at 100°C with 3 hour retention time, 12.5% ammonium hydroxide and 1:30 solid loading. The digestibility of the feedstock is determined with enzymatic hydrolysis using Cellic Ctech2 and Cellic Htech2. The sugars produced by pressurized chamber method within 24 hour of enzyme hydrolysis are similar to that produced by NaOH method which is 439.90 mg/ml and 351.61 mg/ml, respectively. Compared with optimum SAA method (24 hour, 6.25% of ammonium hydroxide at room temperature), pressurized chamber method was capable of producing enhanced delignification and higher production of sugar upon hydrolysis. These findings were supported by the disappearance peak at 1732, 1512 and 1243 on Fourier Transform Infrared (FTIR spectrum) of treated OPEFB by pressurized chamber method. XRD determination showed reduced crystallinity of OPEFB (37.23%) after treatment by pressurized chamber, suggesting higher accessibility toward enzyme hydrolysis. The data obtained suggest that the pressurized chamber pre-treatment method are suitable for OPEFB deconstruction to produce high yield of sugar.

Urinary catheters: history, current status, adverse events and research agenda

PubMed Central

Feneley, Roger C. L.; Hopley, Ian B.; Wells, Peter N. T.

2015-01-01

Abstract For more than 3500 years, urinary catheters have been used to drain the bladder when it fails to empty. For people with impaired bladder function and for whom the method is feasible, clean intermittent self-catheterization is the optimal procedure. For those who require an indwelling catheter, whether short- or long-term, the self-retaining Foley catheter is invariably used, as it has been since its introduction nearly 80 years ago, despite the fact that this catheter can cause bacterial colonization, recurrent and chronic infections, bladder stones and septicaemia, damage to the kidneys, the bladder and the urethra, and contribute to the development of antibiotic resistance. In terms of medical, social and economic resources, the burden of urinary retention and incontinence, aggravated by the use of the Foley catheter, is huge. In the UK, the harm resulting from the use of the Foley catheter costs the National Health Service between £1.0–2.5 billion and accounts for ∼2100 deaths per year. Therefore, there is an urgent need for the development of an alternative indwelling catheter system. The research agenda is for the new catheter to be easy and safe to insert, either urethrally or suprapubically, to be retained reliably in the bladder and to be withdrawn easily and safely when necessary, to mimic natural physiology by filling at low pressure and emptying completely without damage to the bladder, and to have control mechanisms appropriate for all users. PMID:26383168

Performance Study of Chromium (VI) Removal in Presence of Phenol in a Continuous Packed Bed Reactor by Escherichia coli Isolated from East Calcutta Wetlands

PubMed Central

Chakraborty, Bhaswati; Indra, Suvendu; Hazra, Ditipriya; Betai, Rupal; Ray, Lalitagauri; Basu, Srabanti

2013-01-01

Organic pollutants, like phenol, along with heavy metals, like chromium, are present in various industrial effluents that pose serious health hazard to humans. The present study looked at removal of chromium (VI) in presence of phenol in a counter-current continuous packed bed reactor packed with E. coli cells immobilized on clay chips. The cells removed 85% of 500 mg/L of chromium (VI) from MS media containing glucose. Glucose was then replaced by 500 mg/L phenol. Temperature and pH of the MS media prior to addition of phenol were 30°C and 7, respectively. Hydraulic retention times of phenol- and chromium (VI)-containing synthetic media and air flow rates were varied to study the removal efficiency of the reactor system. Then temperature conditions of the reactor system were varied from 10°C to 50°C, the optimum being 30°C. The pH of the media was varied from pH 1 to pH 12, and the optimum pH was found to be 7. The maximum removal efficiency of 77.7% was achieved for synthetic media containing phenol and chromium (VI) in the continuous reactor system at optimized conditions, namely, hydraulic retention time at 4.44 hr, air flow rate at 2.5 lpm, temperature at 30°C, and pH at 7. PMID:24073400

Endoscopic Evaluation of Gastric Emptying and Effect of Mosapride Citrate on Gastric Emptying

PubMed Central

Jung, In Su; Kim, Jie-Hyun; Lee, Hwal Youn; Lee, Sang In

2010-01-01

Purpose Gastric emptying has been evaluated by scintigraphy in spite of its limitations of time consumption, cost, and danger of radioisotope. Endoscopy is a simple technique, however, its validation for gastric emptying and quantification of food has not yet been investigated. The aim of our study was to assess endoscopic gastric emptying compared with scintigraphy and radiopaque markers (ROMs) studies. We also investigated the effect of a single dose of mosapride on gastric emptying. Materials and Methods Fifteen healthy volunteers underwent scintigraphy. Next day, subjects received a standard solid meal with ROMs and underwent endoscopy and simple abdomen X-ray after 3 hrs. After one week, the same procedure was repeated after ingestion of mosapride (5 mg for group 1, n = 8; 10 mg for group 2, n = 7) 15 min before the meal. Quantification of gastric residue by endoscopy was scored from 0 to 3, and the scores were added up. Results All subjects completed the study without any complication. The gastric emptying rate [T1/2 (min)] was in normal range (65.6 ± 12.6 min). Endoscopic gastric emptying was correlated significantly with gastric clearance of ROMs (r = 0.627, p = 0.012). Endoscopic gastric emptying and gastric clearance of ROMs after administration of mosapride showed significant differences in the 10 mg group (p < 0.05). Conclusion Endoscopy can evaluate gastric emptying safely and simply on an outpatient basis. A 10 mg dose of mosapride enhanced gastric emptying, assessed by both endoscopy and ROMs. PMID:20046511

Seasonal variations of nitrogen and phosphorus retention in an agricultural drainage river in East China.

PubMed

Chen, Dingjiang; Lu, Jun; Wang, Hailong; Shen, Yena; Kimberley, Mark O

2010-02-01

Riverine retention decreases loads of nitrogen (N) and phosphorus (P) in running water. It is an important process in nutrient cycling in watersheds. However, temporal riverine nutrient retention capacity varies due to changes in hydrological, ecological, and nutrient inputs into the watershed. Quantitative information of seasonal riverine N and P retention is critical for developing strategies to combat diffuse source pollution and eutrophication in riverine and coastal systems. This study examined seasonal variation of riverine total N (TN) and total P (TP) retention in the ChangLe River, an agricultural drainage river in east China. Water quality, hydrological parameters, and hydrophyte coverage were monitored along the ChangLe River monthly during 2004-2006. Nutrient export loads (including chemical fertilizer, livestock, and domestic sources) entering the river from the catchment area were computed using an export coefficient model based on estimated nutrient sources. Riverine TN and TP retention loads (RNRL and RPRL) were estimated using mass balance calculations. Temporal variations in riverine nutrient retention were analyzed statistically. Estimated annual riverine retention loads ranged from 1,538 to 2,127 t year(-1) for RNRL and from 79.4 to 90.4 t year(-1) for RPRL. Monthly retention loads varied from 6.4 to 300.8 t month(-1) for RNRL and from 1.4 to 15.3 t month(-1) for RPRL. Both RNRL and RPRL increased with river flow, water temperature, hydrophyte coverage, monthly sunshine hours, and total TN and TP inputs. Dissolved oxygen concentration and the pH level of the river water decreased with RNRL and RPRL. Riverine nutrient retention ratios (retention as a percentage of total input) were only related to hydrophyte coverage and monthly sunshine hours. Monthly variations in RNRL and RPRL were functions of TN and TP loads. Riverine nutrient retention capacity varied with environmental conditions. Annual RNRL and RPRL accounted for 30.3-48.3% and 52.5-71.2%, respectively, of total input TN and TP loads in the ChangLe River. Monthly riverine retention ratios were 3.5-88.7% for TN and 20.5-92.6% for TP. Hydrophyte growth and coverage on the river bed is the main cause for seasonal variation in riverine nutrient retention capacity. The total input TN and TP loads were the best indicators of RNRL and RPRL, respectively. High riverine nutrient retention capacity during summer due to hydrophytic growth is favorable to the avoidance of algal bloom in both river systems and coastal water in southeast China. Policies should be developed to strictly control nutrient applications on agricultural lands. Strategies for promoting hydrophyte growth in rivers are desirable for water quality management.

Catastrophic health expenditure: a comparative analysis of empty-nest and non-empty-nest households with seniors in Shandong, China.

PubMed

Yang, Tingting; Chu, Jie; Zhou, Chengchao; Medina, Alexis; Li, Cuicui; Jiang, Shan; Zheng, Wengui; Sun, Liyuan; Liu, Jing

2016-07-05

The aim of this study was to compare the catastrophic health expenditure (CHE) prevalence and its determinants between empty-nest and non-empty-nest elderly households. Shandong province of China. A total of 2761 elderly households are included in the analysis. CHE incidence among elderly households was 44.9%. The CHE incidence of empty-nest singles (59.3%, p=0.000, OR=3.19) and empty-nest couples (52.9%, p=0.000, OR=2.45) are both statistically higher than that of non-empty-nest elderly households (31.4%). An inverse association was observed between CHE incidence and income level in all elderly household types. Factors including 1 or more household elderly members with non-communicable chronic diseases in the past 6 months, 1 or more elderly household members being hospitalised in the past year and lower household income, are significant risk factors for CHE in all 3 household types (p<0.05). Health insurance status was found to be a significant determinant of CHE among empty-nest singles and non-empty-nest households (p<0.05). CHE incidence among elderly households is high in China. Empty-nest households are at higher risk for CHE than non-empty-nest households. Based on these findings, we suggest that special insurance be developed to broaden the coverage of health services and heighten the reimbursement rate for empty-nest elderly in the existing health insurance schemes. Financial and social protection interventions are also essential for identified at-risk subgroups among different types of elderly households. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Catastrophic health expenditure: a comparative analysis of empty-nest and non-empty-nest households with seniors in Shandong, China

PubMed Central

Yang, Tingting; Chu, Jie; Zhou, Chengchao; Medina, Alexis; Li, Cuicui; Jiang, Shan; Zheng, Wengui; Sun, Liyuan; Liu, Jing

2016-01-01

Objective The aim of this study was to compare the catastrophic health expenditure (CHE) prevalence and its determinants between empty-nest and non-empty-nest elderly households. Setting Shandong province of China. Participants A total of 2761 elderly households are included in the analysis. Results CHE incidence among elderly households was 44.9%. The CHE incidence of empty-nest singles (59.3%, p=0.000, OR=3.19) and empty-nest couples (52.9%, p=0.000, OR=2.45) are both statistically higher than that of non-empty-nest elderly households (31.4%). An inverse association was observed between CHE incidence and income level in all elderly household types. Factors including 1 or more household elderly members with non-communicable chronic diseases in the past 6 months, 1 or more elderly household members being hospitalised in the past year and lower household income, are significant risk factors for CHE in all 3 household types (p<0.05). Health insurance status was found to be a significant determinant of CHE among empty-nest singles and non-empty-nest households (p<0.05). Conclusions CHE incidence among elderly households is high in China. Empty-nest households are at higher risk for CHE than non-empty-nest households. Based on these findings, we suggest that special insurance be developed to broaden the coverage of health services and heighten the reimbursement rate for empty-nest elderly in the existing health insurance schemes. Financial and social protection interventions are also essential for identified at-risk subgroups among different types of elderly households. PMID:27381206

Exploring the potential of fungi for methane abatement: Performance evaluation of a fungal-bacterial biofilter.

PubMed

Lebrero, Raquel; López, Juan Carlos; Lehtinen, Iiro; Pérez, Rebeca; Quijano, Guillermo; Muñoz, Raúl

2016-02-01

Despite several fungal strains have been retrieved from methane-containing environments, the actual capacity and role of fungi on methane abatement is still unclear. The batch biodegradation tests here performed demonstrated the capacity of Graphium sp. to co-metabolically biodegrade methane and methanol. Moreover, the performance and microbiology of a fungal-bacterial compost biofilter treating methane at concentrations of ∼2% was evaluated at empty bed residence times of 40 and 20 min under different irrigation rates. The daily addition of 200 mL of mineral medium resulted in elimination capacities of 36.6 ± 0.7 g m(-3) h(-1) and removal efficiencies of ≈90% at the lowest residence time. The indigenous fungal community of the compost was predominant in the final microbial population and outcompeted the inoculated Graphium sp. during biofilter operation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Performances of two biotrickling filters in treating H₂S-containing waste gases and analysis of corresponding bacterial communities by pyrosequencing.

PubMed

Li, Jianjun; Ye, Guangyun; Sun, Duanfang; Sun, Guoping; Zeng, Xiaowei; Xu, Jian; Liang, Shizhong

2012-09-01

Two identical biotrickling filters named BTFa and BTFb were run in parallel to examine their performances in removing hydrogen sulfide. BTFa was filled with ceramic granules, and BTFb was filled with volcanic rocks. The results showed that BTFb was more robust than BTFa under acidic conditions. At empty bed residence times (EBRTs) of 20 and 15 s, the removal efficiency of BTFa was close to 100%. At EBRTs of 10 and 5 s, the removal efficiency of BTFa slightly decreased. The removal efficiencies of BTFa decreased by different degrees at the end of each stage, dropping to 94%, 81%, 60%, and 71%, respectively. However, the H(2)S removal efficiency in BTFb consistently reached 99% throughout the experiment. Pyrosequencing analyses indicated that members of Thiomonas dominated in both BTFs, but the relative abundance of Acidithiobacillus was higher in BTFb than in BTFa.

The enuretic episode--a complete micturition from a bladder with normal capacity? A critical reappraisal of the definition.

PubMed

Rasmussen, P V; Kirk, J; Rittig, S; Djurhuus, J C

1997-01-01

Fifty-five normal children, aged between 7 and 12 years, were hospitalised for four consecutive nights. On three of these nights, the subjects received 25 ml/kg body weight of fluid prior to bedtime. Such fluid-loading provoked 28 enuresis-like episodes in 17 children, most of which occurred during the first few hours of sleep. The incidence of these enuretic events decreased with increasing age, more boys than girls were affected, there was a statistically significant correlation between total enuresis volume and nocturia volume, and the micturition was frequently incomplete, leaving large volumes of residual urine in the bladder. It was concluded that if nocturnal urine production exceeds bladder capacity, enuresis may be provoked, even in children who do not normally wet the bed. Furthermore, the definition of nocturnal enuresis as a complete emptying of the bladder during sleep may need revision.

Analysis of change of retention capacity of a small water reservoir

NASA Astrophysics Data System (ADS)

Výleta, R.; Danáčová, M.; Valent, P.

2017-10-01

This study is focused on the analysis of the changes of retention capacity of a small water reservoir induced by intensive erosion and sedimentation processes. The water reservoir is situated near the village of Vrbovce in the Western part of Slovakia, and the analysis is carried out for a period 2008-2017. The data used to build a digital elevation model (DEM) of the reservoir’s bed came from a terrain measurement, utilizing an acoustic Doppler current profiler (ADCP) to measure the water depth in the reservoir. The DEM was used to quantify the soil loss from agricultural land situated within the basin of the reservoir. The ability of the water reservoir to transform a design flood with a return period of 100 years is evaluated for both design (2008) and current conditions (2017). The results show that the small water reservoir is a subject to siltation, with sediments comprised of fine soil particles transported from nearby agricultural land. The ability of the water reservoir to transform a 100-year flood has not changed significantly. The reduction of the reservoir’s retention capacity should be systematically and regularly monitored in order to adjust its operational manual and improve its efficiency.

Effect of sludge retention time on the biological performance of anaerobic membrane bioreactors treating corn-to-ethanol thin stillage with high lipid content.

PubMed

Dereli, Recep Kaan; van der Zee, Frank P; Heffernan, Barry; Grelot, Aurelie; van Lier, Jules B

2014-02-01

The potential of anaerobic membrane bioreactors (AnMBRs) for the treatment of lipid rich corn-to-ethanol thin stillage was investigated at three different sludge retention times (SRT), i.e. 20, 30 and 50 days. The membrane assisted biomass retention in AnMBRs provided an excellent solution to sludge washout problems reported for the treatment of lipid rich wastewaters by granular sludge bed reactors. The AnMBRs achieved high COD removal efficiencies up to 99% and excellent effluent quality. Although higher organic loading rates (OLRs) up to 8.0 kg COD m(-3) d(-1) could be applied to the reactors operated at shorter SRTs, better biological degradation efficiencies, i.e. up to 83%, was achieved at increased SRTs. Severe long chain fatty acid (LCFA) inhibition was observed at 50 days SRT, possibly caused by the extensive dissolution of LCFA in the reactor broth, inhibiting the methanogenic biomass. Physicochemical mechanisms such as precipitation with divalent cations and adsorption on the sludge played an important role in the occurrence of LCFA removal, conversion, and inhibition. Copyright © 2013 Elsevier Ltd. All rights reserved.

Delayed gastric emptying of both the liquid and solid components of a meal in chronic liver disease.

PubMed

Galati, J S; Holdeman, K P; Dalrymple, G V; Harrison, K A; Quigley, E M

1994-05-01

To evaluate gastric emptying in patients with chronic liver disease and portal hypertension. We measured gastric emptying of both the liquid and solid components of a meal in 10 consecutive patients with chronic liver disease and portal hypertension, but free of ascites, and 14 age- and sex-matched healthy controls. In the patients with liver disease, relationships between emptying and liver function were examined. To measure gastric emptying, subjects consumed a test meal that consisted of scrambled eggs labeled with 99mTc-sulfur colloid and 4 oz of water labeled with 111In-diethylene triamine pentacetic acid (DTPA). Patients with liver disease and portal hypertension demonstrated delayed emptying of both the liquid (t1/2, min, mean +/- SE, patients vs. 69.4 +/- 19.4 vs. 31.4 +/- 1.8, p < 0.01) and solid (post-lag phase solid emptying: 141 +/- 32.9 vs. 69.8 +/- 4.6, p < 0.006) components of the meal. We could not identify any correlation between gastric emptying and tests of liver function. Gastric emptying is delayed in patients with liver disease and portal hypertension; this abnormal gastric motor function may contribute to the pathophysiology of foregut complaints in this patient population.

Canine gastric emptying of fiber meals: influence of meal viscosity and antroduodenal motility.

PubMed

Russell, J; Bass, P

1985-12-01

Dietary fibers such as psyllium and guar gum have been shown to delay the gastric emptying of liquids and solids, presumably due to an increase in meal viscosity. For liquid test meals containing fats, delayed gastric emptying is associated with a reversal of the usual antral-to-duodenal contractile gradient. The present studies were performed to determine whether the gastric emptying of increasingly viscous psyllium and guar gum meals was associated with antroduodenal motility changes. Dogs were surgically fitted with mid-duodenal cannulas for the measurement of gastric emptying. Strain-gauge force transducers were used to monitor antral and duodenal contractile responses to the test meals. Low-viscosity fiber meals emptied from the stomach rapidly (E 1/2 approximately 10 min) compared with the high-viscosity meals (E 1/2 approximately 40 min). None of the test meals stimulated antral or duodenal motility despite differences in gastric emptying time. Other motor parameters such as the time of reappearance and the duration of the burst interval were also unchanged. We conclude a) as test meals' fiber content and viscosity increase, gastric emptying is slowed; and b) viscosity-related delays in gastric emptying are not due to an effect on postprandial antroduodenal motility.

49 CFR 173.29 - Empty packagings.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Empty packagings. 173.29 Section 173.29... SHIPMENTS AND PACKAGINGS Preparation of Hazardous Materials for Transportation § 173.29 Empty packagings. (a) General. Except as otherwise provided in this section, an empty packaging containing only the residue of a...

Comprehensive Comparison between Empty Nest and Non-Empty Nest Elderly: A Cross-Sectional Study among Rural Populations in Northeast China

PubMed Central

Chang, Ye; Guo, Xiaofan; Guo, Liang; Li, Zhao; Yang, Hongmei; Yu, Shasha; Sun, Guozhe; Sun, Yingxian

2016-01-01

This study aimed to comprehensively compare the general characteristics, lifestyles, serum parameters, ultrasonic cardiogram (UCG) parameters, depression, quality of life, and various comorbidities between empty nest and non-empty nest elderly among rural populations in northeast China. This analysis was based on our previous study which was conducted from January 2012 to August 2013, using a multistage, stratified, random cluster sampling scheme. The final analyzed sample consisted of 3208 participants aged no less than 60 years, which was further classified into three groups: non-empty nest group, empty nest group (living as a couple), and empty nest group (living alone). More than half of the participants were empty nest elderly (60.5%). There were no significant statistical differences for serum parameters, UCG parameters, lifestyles, dietary pattern, and scores of Patient Health Questionnaire-9 (PHQ-9) and World Health Organization Quality of Life questionnaire, abbreviated version (WHOQOL-BREF) among the three groups. Empty nest elderly showed no more risk for comorbidities such as general obesity, abdominal obesity, hyperuricemia, hyperhomocysteinemia, diabetes, dyslipidemia, left atrial enlargement (LAE), and stroke. Our study indicated that empty nest elderly showed no more risk for depression, low quality of life and comorbidities such as general obesity, abdominal obesity, hyperuricemia, hyperhomocysteinemia, diabetes, dyslipidemia, LAE, and stroke among rural populations in northeast China. PMID:27618905

Comprehensive Comparison between Empty Nest and Non-Empty Nest Elderly: A Cross-Sectional Study among Rural Populations in Northeast China.

PubMed

Chang, Ye; Guo, Xiaofan; Guo, Liang; Li, Zhao; Yang, Hongmei; Yu, Shasha; Sun, Guozhe; Sun, Yingxian

2016-08-27

This study aimed to comprehensively compare the general characteristics, lifestyles, serum parameters, ultrasonic cardiogram (UCG) parameters, depression, quality of life, and various comorbidities between empty nest and non-empty nest elderly among rural populations in northeast China. This analysis was based on our previous study which was conducted from January 2012 to August 2013, using a multistage, stratified, random cluster sampling scheme. The final analyzed sample consisted of 3208 participants aged no less than 60 years, which was further classified into three groups: non-empty nest group, empty nest group (living as a couple), and empty nest group (living alone). More than half of the participants were empty nest elderly (60.5%). There were no significant statistical differences for serum parameters, UCG parameters, lifestyles, dietary pattern, and scores of Patient Health Questionnaire-9 (PHQ-9) and World Health Organization Quality of Life questionnaire, abbreviated version (WHOQOL-BREF) among the three groups. Empty nest elderly showed no more risk for comorbidities such as general obesity, abdominal obesity, hyperuricemia, hyperhomocysteinemia, diabetes, dyslipidemia, left atrial enlargement (LAE), and stroke. Our study indicated that empty nest elderly showed no more risk for depression, low quality of life and comorbidities such as general obesity, abdominal obesity, hyperuricemia, hyperhomocysteinemia, diabetes, dyslipidemia, LAE, and stroke among rural populations in northeast China.

The use of a paper/wood/plastics mixing as a model waste to study the incineration of municipal solid waste in fluidized beds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Desroches-Ducarne, E.; Marty, E.; Martin, G.

1997-12-31

Municipal Solid Waste (MSW) incineration in fluidized beds has recently become the subject of intense research. In this paper, the authors chose to elaborate a simple model waste prepared with 4 of the main MSW components (paper, wood, PE, and PVC). The behaviors of typical French MSW and model waste during their combustion in a fluidized bed incinerator were studied. To establish the comparison, the emissions of NO, N{sub 2}O, SO{sub 2} and HCl were investigated. Moreover, experiments were performed according to statistical experimental designs to examine the effect of various operating parameters including bed temperature, excess air, limestone feedingmore » rate and waste moisture. On a qualitative point of view, the impact of the combustion conditions on the pollutants emissions was found to be the same for the two wastes. Bed temperature and excess air have, in both cases, an important impact on NO and N{sub 2}O emissions. Nitrogen oxides production was also directly related to limestone feed content. Very high sulphur and chlorine retention was obtained when limestone was added at much larger excess to the feed. N{sub 2}O emissions are less important during the model waste combustion. The nitrogen functionality seems to give rise to such a phenomenon. In MSW, nitrogen is included in high molecules which is released for a great part as HCN or remains in char, which are the main sources of N{sub 2}O. To confirm this assumption, tests for measuring the HCN/NH{sub 3} ratio for each fuel were performed.« less

Field trial of a pulsed limestone diversion well

USGS Publications Warehouse

Sibrell, Philip L.; Denholm, C.; Dunn, Margaret

2013-01-01

The use of limestone diversion wells to treat acid mine drainage (AMD) is well-known, but in many cases, acid neutralization is not as complete as would be desired. Reasons for this include channeling of the water through the limestone bed, and the slow reaction rate of the limestone gravel. A new approach to improve the performance of the diversion well was tested in the field at the Jennings Environmental Education Center, near Slippery Rock, PA. In this approach, a finer size distribution of limestone was used so as to allow fluidization of the limestone bed, thus eliminating channeling and increasing particle surface area for faster reaction rates. Also, water flow was regulated through the use of a dosing siphon, so that consistent fluidization of the limestone sand could be achieved. Testing began late in the summer of 2010, and continued through November of 2011. Initial system performance during the 2010 field season was good, with the production of net alkaline water, but hydraulic problems involving air release and limestone sand retention were observed. In the summer of 2011, a finer size of limestone sand was procured for use in the system. This material fluidized more readily, but acid neutralization tapered off after several days. Subsequent observations indicated that the hydraulics of the system was compromised by the formation of iron oxides in the pipe leading to the limestone bed, which affected water distribution and flow through the bed. Although results from the field trial were mixed, it is believed that without the formation of iron oxides and plugging of the pipe, better acid neutralization and treatment would have occurred. Further tests are being considered using a different hydraulic configuration for the limestone sand fluidized bed.

A New Fluidized Bed Bioreactor Based on Diversion-Type Microcapsule Suspension for Bioartificial Liver Systems

PubMed Central

Li, Jianzhou; Yu, Liang; Chen, Ermei; Zhu, Danhua; Zhang, Yimin; Li, LanJuan

2016-01-01

A fluidized bed bioreactor containing encapsulated hepatocytes may be a valuable alternative to a hollow fiber bioreactor for achieving the improved mass transfer and scale-up potential necessary for clinical use. However, a conventional fluidized bed bioreactor (FBB) operating under high perfusion velocity is incapable of providing the desired performance due to the resulting damage to cell-containing microcapsules and large void volume. In this study, we developed a novel diversion-type microcapsule-suspension fluidized bed bioreactor (DMFBB). The void volume in the bioreactor and stability of alginate/chitosan microcapsules were investigated under different flow rates. Cell viability, synthesis and metabolism functions, and expression of metabolizing enzymes at transcriptional levels in an encapsulated hepatocyte line (C3A cells) were determined. The void volume was significantly less in the novel bioreactor than in the conventional FBB. In addition, the microcapsules were less damaged in the DMFBB during the fluidization process as reflected by the results for microcapsule retention rates, swelling, and breakage. Encapsulated C3A cells exhibited greater viability and CYP1A2 and CYP3A4 activity in the DMFBB than in the FBB, although the increases in albumin and urea synthesis were less prominent. The transcription levels of several CYP450-related genes and an albumin-related gene were dramatically greater in cells in the DMFBB than in those in the FBB. Taken together, our results suggest that the DMFBB is a promising alternative for the design of a bioartificial liver system based on a fluidized bed bioreactor with encapsulated hepatocytes for treating patients with acute hepatic failure or other severe liver diseases. PMID:26840840

Implementation of a salaried compensation program for registered nurses.

PubMed

Sills, L R

1993-01-01

Compensation is a key variable in recruitment and retention of registered nurses. A 6-month trial of an exempt/salaried wage program for registered nurses, based on normative change theory, was implemented in the adult critical care division of a 491-bed community hospital. A total of 58 registered nurses participated in the trial. At the end of 6 months on salary, 94% (53) of the nurses voted to remain salaried. The staff perceived that the new wage program increased flexibility in work schedules and promoted teamwork and professional autonomy.

Safety at The William Quarrier Scottish Epilepsy Centre.

PubMed

Anderson, James; Grant, Victoria; Elgammal, Mariam; Campbell, Alison; Hampshire, Julia; Hansen, Stig; Russell, Aline J C

2017-12-01

We examined the yield from EMFIT bed alarms and staff response time to generalised seizure in a medium term residential assessment unit for epilepsy. The Scottish Epilpesy Centre (SEC) has a Video Observation System (VOS) that provides continuous recording of all patient spaces (external and internal) and allows retention of clinically relevant events. A retrospective audit of daily EMFIT test records, nursing seizure record sheets (seizure type and EMFIT alert status), clinical incident reporting systems and the VOS database of retained clinical events was conducted for an 9 month period from April 1st 2016 till December 31st 2016. All generalized tonic clonic seizures (GTCS) were noted by patient, time and location and staff response time to GTCS was calculated. There were 85 people admitted during the audit period who had 61 GTCS. 50 events were in bed and EMFIT alert status was recorded. On 8 occasions the EMFIT did not alert: 5 events were not of sufficient duration or frequency, in 2 the patient fell from the bed early and 1 event the alarm did not trigger. The average response time to GTCS was 23s. The longest response time was 69s (range, 0-69s, sd 15.76.). The EMFIT bed alarm appears to be a valuable adjunct to safety systems. Within the novel environment of the SEC it is possible to maintain a response time to GTCS that is comparable to hospital based UK video telemetry units. Copyright © 2017 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

Characterization of coals for circulating fluidized bed combustion by pilot scale tests

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lopez, L.A.; Cabanillas, A.C.; Becerra, J.O. de

1995-12-31

The major part of the Spanish coal supply is low range coal with both high ash (20--40%) and sulfur (1--8%) content. The use of this coal, by conventional combustion processes in power and industrial plants, implies a very high environmental impact. The Circulating Fluidized Bed Combustion process enables an efficient use of this coal. The Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas is carrying out a program with the intention of assisting companies in evaluating fuel quality impact, using atmospheric fluidized bed combustion. This paper reviews the major results of the fuel program in order to determine the fluidized bedmore » combustion performance of four fuels. Two lignites, a bituminous coal and an anthracite. The two lignites have very high sulfur content (7% and 8%) but the sulfur is organic in one case and pyritic in the other. The bituminous coal and the anthracite have 1% and 2% sulfur content respectively and the sulfur is pyritic in these cases. In order to reduce the sulfur in the flue gases, a high calcium content limestone has been used as sorbent. The combustion trials have been done in a circulating fluidized bed pilot plant with a 200 mm inside diameter and a height of 6.5 m. The influence of temperature, fluidization velocity, oxygen excess, Ca/S ratio and coal properties have been studied in relation to the combustion efficiency, sulfur retention, CO and NO{sub x} emissions.« less

14 CFR 223.24 - Transportation of empty mail bags.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Transportation of empty mail bags. Any carrier authorized to engage in foreign air transportation may transport in foreign air transportation empty air mail bags from any country to the country of origin of such... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Transportation of empty mail bags. 223.24...

14 CFR 223.24 - Transportation of empty mail bags.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Transportation of empty mail bags. Any carrier authorized to engage in foreign air transportation may transport in foreign air transportation empty air mail bags from any country to the country of origin of such... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Transportation of empty mail bags. 223.24...

14 CFR 223.24 - Transportation of empty mail bags.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Transportation of empty mail bags. Any carrier authorized to engage in foreign air transportation may transport in foreign air transportation empty air mail bags from any country to the country of origin of such... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Transportation of empty mail bags. 223.24...

The stomach, cholecystokinin, and satiety.

PubMed

McHugh, P R; Moran, T H

1986-04-01

The stomach of the rhesus monkey empties liquids in a fashion that varies with the character of the solutions. Physiological saline empties exponentially. Glucose solutions empty biphasically--rapidly for the first minutes, then slowly and proportionately to glucose concentration to deliver glucose calories through the pylorus at a regulated rate (0.4 kcal/min). This prolonged and regulated second phase of gastric emptying depends on intestinal inhibition of the stomach. Cholecystokinin (CCK), a hormone released by food in the intestine, is an inhibitor of gastric emptying. In vitro receptor autoradiography demonstrates CCK receptors to be clustered on the circular muscle of the pylorus. Exogenous CCK, in doses that inhibit gastric emptying, will reduce food intake only if combined with an infusion of saline in the stomach. These observations indicate how gastric distension can be a means for provoking satiety. The variably sustained distension produced by the stomach's slow, calorically regulated emptying could prolong intermeal intervals and thus permit high-calorie meals to inhibit further caloric intake over time. CCK, by directly inhibiting gastric emptying during a meal, could promote gastric distension and so restrict the duration and size of individual meals.

Effect of parenteral administration of erythromycin, tilmicosin, and tylosin on abomasal emptying rate in suckling calves.

PubMed

Nouri, Mohammad; Constable, Peter D

2007-12-01

To determine the effect of parenteral administration of erythromycin, tilmicosin, and tylosin on abomasal emptying rate in suckling calves. 8 male Holstein-Friesian calves < 35 days old. Calves received each of 4 treatments in random order (2 mL of saline [0.9% NaCl] solution, IM [control treatment]; erythromycin, 8.8 mg/kg, IM; tilmicosin, 10 mg/kg, SC; and tylosin, 17.6 mg/kg, IM). Calves were fed 2 L of milk replacer containing acetaminophen (50 mg/kg) 30 minutes later. Jugular venous blood samples and transabdominal ultrasonographic abomasal dimensions were obtained periodically after suckling. Abomasal emptying rate was assessed on the basis of the time to maximal plasma acetaminophen concentration and ultrasonographic determination of the halftime of abomasal emptying. One-tailed Dunnett post tests were conducted whenever the F value for group was significant. Emptying rate was faster for erythromycin, tilimicosin, and tylosin than for the control treatment, as determined on the basis of time to maximal plasma acetaminophen concentration. Ultrasonography indicated that the half-time of abomasal emptying was significantly shorter for erythromycin than for the control treatment. Tylosin and tilmicosin accelerated the abomasal emptying rate, but not significantly, relative to the emptying rate for the control treatment. Administration of erythromycin, tilmicosin, and tylosin at the label dosage increased abomasal emptying rate in calves. The clinical importance of an increase in abomasal emptying rate in cattle remains to be determined.

Relation between gastric emptying rate and energy intake in children compared with adults.

PubMed Central

Maes, B D; Ghoos, Y F; Geypens, B J; Hiele, M I; Rutgeerts, P J

1995-01-01

Measurement of gastric emptying rate of solids in children is difficult because the available methods are either invasive or induce a substantial radiation burden. In this study the newly developed 13C octanoic acid breath test was used to examine the gastric emptying rate of solids and milk in healthy children and to compare gastric emptying in children and adults. Fifteen healthy children and three groups of nine healthy adults were studied, using three different test meals labelled with 50 mg of 13C octanoic acid: a low caloric pancake (150 kcal), a high caloric pancake (250 kcal), and 210 ml of milk (134 kcal). Breath samples were taken before and at regular intervals after ingestion of the test meal, and analysed by isotope ratio mass spectrometry. The gastric emptying parameters were derived from the 13CO2 excretion curves by non-linear regression analysis. No significant difference was found between children and adults in the emptying rate of the low caloric solid test meal. In children as well as in adults, increasing the energy content of the solid meal resulted in a significantly slower emptying rate. The milk test meal, however, was emptied at a faster rate in adults and at slower rate in children compared with the low caloric solid test meal. Moreover, the emptying rate of milk in children was significantly slower than in adults. In conclusion, a similar gastric emptying rate of solids but a slower emptying of full cream milk was shown in children of school age compared with adults, using the non-radioactive 13C octanoic acid breath test. PMID:7883214

Efficient Capsid Antigen Presentation From Adeno-Associated Virus Empty Virions In Vivo.

PubMed

Pei, Xiaolei; Earley, Lauriel Freya; He, Yi; Chen, Xiaojing; Hall, Nikita Elexa; Samulski, Richard Jude; Li, Chengwen

2018-01-01

Adeno-associated virus (AAV) vectors have been successfully applied in clinical trials for hemophilic patients. Although promising, the clinical results suggest that the capsid-specific CD8+T cell response has a negative effect on therapeutic success. In an in vitro analysis using an engineered AAV virus carrying immune-dominant SIINFEKL peptide in the capsid backbone, we have previously demonstrated that capsid antigen presentation from full (genome containing) AAV capsids requires endosome escape and is proteasome dependent and that no capsid antigen presentation is induced from empty virions. In the present study, we examined capsid antigen presentation from administration of empty virions in animal models. In wild-type mice, similar to AAV full particles, capsid antigen presentation from AAV empty virion infection was dose dependent, and the kinetics studies showed that antigen presentation was detected from 2 to 40 days after AAV empty virion administration. In the transporter associated with antigen processing 1 deficient (TAP-/-) mice, capsid antigen presentation was inhibited from both AAV full and empty virions, but higher inhibition was achieved from AAV full particle administration than that from empty virions. This indicates that the pathway of capsid antigen presentation from AAV transduction is dependent on proteasome-mediated degradation of AAV capsids (mainly for full particles) and that the endosomal pathway may also play a role in antigen presentation from empty particles but not full virions. The capsid antigen presentation efficiency from AAV preparations was positively correlated with the amount of empty virions contaminated with full particles. Collectively, the results indicate that contamination of AAV empty virions induces efficient antigen presentation in vivo and the mechanism of capsid antigen presentation from empty virions involves both endosomal and proteasomal pathways. The elucidation of capsid antigen presentation from AAV empty virions may allow us to rationally design effective strategies to prevent elimination of AAV transduced target cells by capsid specific CD8+ T cells.

Efficient Capsid Antigen Presentation From Adeno-Associated Virus Empty Virions In Vivo

PubMed Central

Pei, Xiaolei; Earley, Lauriel Freya; He, Yi; Chen, Xiaojing; Hall, Nikita Elexa; Samulski, Richard Jude; Li, Chengwen

2018-01-01

Adeno-associated virus (AAV) vectors have been successfully applied in clinical trials for hemophilic patients. Although promising, the clinical results suggest that the capsid-specific CD8+T cell response has a negative effect on therapeutic success. In an in vitro analysis using an engineered AAV virus carrying immune-dominant SIINFEKL peptide in the capsid backbone, we have previously demonstrated that capsid antigen presentation from full (genome containing) AAV capsids requires endosome escape and is proteasome dependent and that no capsid antigen presentation is induced from empty virions. In the present study, we examined capsid antigen presentation from administration of empty virions in animal models. In wild-type mice, similar to AAV full particles, capsid antigen presentation from AAV empty virion infection was dose dependent, and the kinetics studies showed that antigen presentation was detected from 2 to 40 days after AAV empty virion administration. In the transporter associated with antigen processing 1 deficient (TAP−/−) mice, capsid antigen presentation was inhibited from both AAV full and empty virions, but higher inhibition was achieved from AAV full particle administration than that from empty virions. This indicates that the pathway of capsid antigen presentation from AAV transduction is dependent on proteasome-mediated degradation of AAV capsids (mainly for full particles) and that the endosomal pathway may also play a role in antigen presentation from empty particles but not full virions. The capsid antigen presentation efficiency from AAV preparations was positively correlated with the amount of empty virions contaminated with full particles. Collectively, the results indicate that contamination of AAV empty virions induces efficient antigen presentation in vivo and the mechanism of capsid antigen presentation from empty virions involves both endosomal and proteasomal pathways. The elucidation of capsid antigen presentation from AAV empty virions may allow us to rationally design effective strategies to prevent elimination of AAV transduced target cells by capsid specific CD8+ T cells. PMID:29725339

Gender Difference of Gastric Emptying in Healthy Volunteers and Patients with Functional Dyspepsia.

PubMed

Mori, Hideki; Suzuki, Hidekazu; Matsuzaki, Juntaro; Taniguchi, Kanami; Shimizu, Toshiyuki; Yamane, Tsuyoshi; Masaoka, Tatsuhiro; Kanai, Takanori

2017-01-01

Delayed gastric emptying is one of the reasons why functional dyspepsia (FD) occurs. The 13C-acetate breath test is widely used to evaluate gastric emptying. Nevertheless, the standard value of 13C-acetate breath test has not taken into account the gender difference of gastric emptying among healthy individuals. The main aim of this study was to readjust the standard value of 13C-acetate breath test in the light of gender differences. In addition, we clarified the prevalence and clinical characteristics of delayed gastric emptying in patients with FD using the modified standard values of 13C-acetate breath test. Fifty-two healthy individuals and 126 patients with patients with FD were enrolled. Gastric emptying was evaluated by the 13C-acetate breath test. The cut-off points of Tmax for the diagnosis of delayed gastric emptying were determined on the basis of results from healthy individuals making a distinction of genders. Gastroesophageal reflux symptoms, dyspeptic symptoms, scores of anxiety and depression, age, body mass index (BMI), smoking and alcohol consumption were compared between the delayed gastric emptying group and the non-delayed gastric emptying group. Since gastric emptying was delayed in healthy women compared with that in healthy men (Tmax, 53.6 ± 19.3 vs. 42.7 ± 16.9 min, p = 0.04), we set the cut-off points of Tmax at 60 min in men and at 75 min in women. In patients with FD, the prevalence of delayed gastric emptying was not different between men and women with the modified standard values of 13C-acetate breath test. (31.0 vs. 27.4%, p = 0.68). BMI was lower in the delayed gastric emptying group than in the non-delayed group among the male patients. Reflux symptoms were more severe in delayed gastric emptying group than in the non-delayed group among the female patients. The standard values of 13C-acetate breath test should be modified bearing the gender difference in mind. It provides us more appropriate information to understand the mechanisms of FD. © 2016 S. Karger AG, Basel.

Effect of selective β-adrenoceptor blockade and surgical resection of the celiac-superior mesenteric ganglion complex on delayed liquid gastric emptying induced by dipyrone, 4-aminoantipyrine, and antipyrine in rats

PubMed Central

Vinagre, A.M.; Collares, E.F.

2016-01-01

There is evidence for participation of peripheral β-adrenoceptors in delayed liquid gastric emptying (GE) induced in rats by dipyrone (Dp), 4-aminoantipyrine (AA), and antipyrine (At). The present study aimed to determine whether β-adrenoceptors are involved in delayed GE induced by phenylpyrazole derivatives and the role of the prevertebral sympathetic nervous system in this condition. Male Wistar rats weighing 220-280 g were used in the study. In the first experiment rats were intravenously pretreated with vehicle (V), atenolol 30 mg/kg (ATE, β1-adrenergic antagonist), or butoxamine 25 mg/kg (BUT, β2-adrenergic antagonist). In the second experiment, rats were pretreated with V or SR59230A 2 mg/kg (SRA, β3-adrenergic antagonist). In the third experiment, rats were subjected to surgical resection of the celiac-superior mesenteric ganglion complex or to sham surgery. The groups were intravenously treated with saline (S), 240 µmol/kg Dp, AA, or At, 15 min after pretreatment with the antagonists or V and nine days after surgery. GE was determined 10 min later by measuring the percentage of gastric retention (%GR) of saline labeled with phenol red 10 min after gavage. The %GR (means±SE, n=6) values indicated that BUT abolished the effect of Dp (BUT+Dp vs V+Dp: 35.0%±5.1% vs 56.4%±2.7%) and At (BUT+At vs V+At: 33.5%±4.7% vs 52.9%±2.6%) on GE, and significantly reduced (P<0.05) the effect of AA (BUT+AA vs V+AA: 48.0%±5.0% vs 65.2%±3.8%). ATE, SRA, and sympathectomy did not modify the effects of treatments. These results suggest that β2-adrenoceptor activation occurred in delayed liquid gastric emptying induced by the phenylpyrazole derivatives dipyrone, 4-aminoantipyrine, and antipyrine. Additionally, the released neurotransmitter did not originate in the celiac-superior mesenteric ganglion complex. PMID:26840714

Energy expenditure and balance during spaceflight on the space shuttle

NASA Technical Reports Server (NTRS)

Stein, T. P.; Leskiw, M. J.; Schluter, M. D.; Hoyt, R. W.; Lane, H. W.; Gretebeck, R. E.; LeBlanc, A. D.

1999-01-01

The objectives of this study were as follows: 1) to measure human energy expenditure (EE) during spaceflight on a shuttle mission by using the doubly labeled water (DLW) method; 2) to determine whether the astronauts were in negative energy balance during spaceflight; 3) to use the comparison of change in body fat as measured by the intake DLW EE, 18O dilution, and dual energy X-ray absorptiometry (DEXA) to validate the DLW method for spaceflight; and 4) to compare EE during spaceflight against that found with bed rest. Two experiments were conducted: a flight experiment (n = 4) on the 16-day 1996 life and microgravity sciences shuttle mission and a 6 degrees head-down tilt bed rest study with controlled dietary intake (n = 8). The bed rest study was designed to simulate the flight experiment and included exercise. Two EE determinations were done before flight (bed rest), during flight (bed rest), and after flight (recovery). Energy intake and N balance were monitored for the entire period. Results were that body weight, water, fat, and energy balance were unchanged with bed rest. For the flight experiment, decreases in weight (2.6 +/- 0.4 kg, P < 0.05) and N retention (-2. 37 +/- 0.45 g N/day, P < 0.05) were found. Dietary intake for the four astronauts was reduced in flight (3,025 +/- 180 vs. 1,943 +/- 179 kcal/day, P < 0.05). EE in flight was 3,320 +/- 155 kcal/day, resulting in a negative energy balance of 1,355 +/- 80 kcal/day (-15. 7 +/- 1.0 kcal. kg-1. day-1, P < 0.05). This corresponded to a loss of 2.1 +/- 0.4 kg body fat, which was within experimental error of the fat loss determined by 18O dilution (-1.4 +/- 0.5 kg) and DEXA (-2.4 +/- 0.4 kg). All three methods showed no change in body fat with bed rest. In conclusion, 1) the DLW method for measuring EE during spaceflight is valid, 2) the astronauts were in severe negative energy balance and oxidized body fat, and 3) in-flight energy (E) requirements can be predicted from the equation: E = 1.40 x resting metabolic rate + exercise.

Kinetic Study of Methyl Acetate Oxidation in a Pt/Al2O3 Fixed-Bed Reactor

NASA Technical Reports Server (NTRS)

Hoy, Michael; Li, K. Y.; Li, Jeffrey S.; Chen, S. M.; Yaws, C. L.; Chu, H. W.; Simon, W. E.

1994-01-01

To support technology development for future long-term missions, a metabolic simulator will be used in a closed chamber to test the functions of a Controlled Ecological Life Support System (CELSS). Methyl acetate (MA) was selected as the fuel because its metabolic respiratory quotient is near that of humans. A kinetic study of the catalytic oxidation of MA over Pt/Al203 was then conducted to support the design and operation of the simulator. Kinetic data were obtained as a conversion percentage of MA versus retention time. The reaction was studied at one atmosphere and temperatures from 220 to 340 deg. C. The inlet MA concentration was varied from 100 to 2000 ppm with retention times from 0.01 to 10 sec. A first-order rate law and a Langmuir-Hinshelwood rate equation were tested by nonlinear regression of the kinetic data to estimate rate constants in the rate law. Regression results of the L-H equation explain the kinetic data better than the results of the first-order rate law. A Taguchi experimental design was used to study the effects of temperature, retention time, and concentrations of MA, CO2, and O2 on the conversion of MA. Results indicate that temperature has greatest effect, followed by retention time, and finally MA concentration. It was further determined that the effects of CO2 and O2 concentrations, and the cross effects, are negligible.

Tritium retention in S-65 beryllium after 100 eV plasma exposure

NASA Astrophysics Data System (ADS)

Causey, Rion A.; Longhurst, Glen R.; Harbin, Wally

1997-02-01

The tritium plasma experiment (TPE) has been used to measure the retention of tritium in S-65 beryllium under conditions similar to that expected for the international thermonuclear experimental reactor (ITER). Beryllium samples 2 mm thick and 50 mm in diameter were exposed to a plasma of tritium and deuterium. The particle flux striking the samples was varied from approximately 1 × 10 17 ( D + T)/ cm2s up to about 3 × 10 18 ( D + T)/ cm2s. The beryllium samples were negatively biased to elevate the energy of the impinging ions to 100 eV. The temperature of the samples was varied from 373 K to 973 K. Exposure times of 1 h were used. Subsequent to the plasma exposure, the samples were outgassed in a separate system where 99% He and 1% H 2 gas was swept over the samples during heating. The sweep gas along with the released tritium was sent through an ionization chamber, through a copper oxide catalyst bed, and into a series of glycol bubblers. The amount of released tritium was determined both by the ionization chamber and by liquid scintillation counting of the glycol. Tritium retention in the beryllium disks varied from a high of 2.4 × 10 17 ( D + T)/ cm2 at 373 K to a low of 1 × 10 16 ( D + T)/ cm2 at 573 K. For almost every case, the tritium retention in the beryllium was less than that calculated using the C = 0 boundary condition at the plasma facing surface. It is believed that this lower than expected retention is due to rapid release of tritium from the large specific surface area created in the implant zone due to the production of voids, bubbles, and blisters.

Modeling Quantum Dot Nanoparticle Fate and Transport in Saturated Porous Media under Varying Flow Conditions

NASA Astrophysics Data System (ADS)

Becker, M. D.; Wang, Y.; Englehart, J.; Pennell, K. D.; Abriola, L. M.

2010-12-01

As manufactured nanomaterials become more prevalent in commercial and industrial applications, the development of mathematical models capable of predicting nanomaterial transport and retention in subsurface systems is crucial to assessing their fate and distribution in the environment. A systematic modeling approach based on a modification of clean-bed filtration theory was undertaken to elucidate mechanisms governing the transport and deposition behavior of quantum dots in saturated quartz sand as a function of grain size and flow velocity. The traditional deposition governing equation, which assumes irreversible attachment by a first-order rate (katt), was modified to include a maximum or limiting retention capacity (Smax) and first-order detachment of particles from the solid phase (kdet). Quantum dot mobility experiments were performed in columns packed with three size fractions of Ottawa sand (d50 = 125, 165, and 335 μm) at two different pore-water velocities (0.8 m/d and 7.6 m/d). The CdSe quantum dots in a CdZnS shell and polyacrylic acid coating were negatively charged (zeta potential measured ca. -35 mV) with a hydrodynamic diameter of approximately 30 nm. Fitted values of katt, Smax, and kdet were obtained for each transport and deposition experiment through the implementation of a nonlinear least-squares routine developed to fit the model to experimental breakthrough and retention data via multivariate optimization. Fitted attachment rates and retention capacities increased exponentially with decreasing grain size at both flow rates, while no discernable trend was apparent for the fitted detachment rates. Maximum retention capacity values were plotted against a normalized mass flux expression, which accounts for flow conditions and grain size. A power function fit to the data yielded a dependence that was consistent with a previous study undertaken with fullerene nanoparticles.

Practical implications of theoretical consideration of capsule filling by the dosator nozzle system.

PubMed

Jolliffe, I G; Newton, J M

1982-05-01

Eight lactose size fractions with mean particle sizes ranging from 15.6 to 155.2 micrometers were characterized by their failure properties using a Jenike shear cell. The effective angle of internal friction was found to be constant for all size fractions, with a mean value of 36.2 degrees. Jenike flow factors could only be obtained for the two most cohesive size fractions presumably due to limitations of the shear cell. Angles of wall friction, phi, were determined for all size fractions on face ground and turned stainless steel surfaces. These decreased with increasing particle size up to around 40 micrometers, above which they became effectively constant for both surfaces. The rougher turned plate gave consistently higher values of phi for each particle size. Simple retention experiments with a dosator nozzle and a range of powder bed bulk densities showed good retention was possible only up to a particle size of around 40 micrometers. Retention was difficult or impossible above this size. Values of phi were applied to equations derived in the theoretical approach described previously (Jolliffe et al 1980). This showed that the strength required within a powder to ensure arching increases with increasing particle size up to around 40 micrometers. Above this size, this strength requirement becomes constant. This is related to the powder retention observations. Finally, the failure data was used to calculate the minimum compressive stresses required to ensure powder retention within the dosator nozzle, by employing the equations described by Jolliffe et al (1980). This suggested that, as powders became more free flowing, a larger compressive stress is necessary and that the angle of wall friction should be lower to ensure stress is transmitted to the arching zone.

Effect of solid-meal caloric content on gastric emptying kinetics of solids and liquids.

PubMed

Urbain, J L; Siegel, J A; Mortelmans, L; van Cutsem, E; van den Maegdenbergh, V; de Roo, M

1989-08-01

In this study, we have evaluated the effect of the caloric content of a physiological test meal on the gastric emptying kinetics of solids and liquids. 22 healthy male volunteers were studied in two groups matched for age. After an overnight fast, each volunteer underwent the same test procedure; in the first group (G I), 10 volunteers received a meal consisting of bread, 111In-DTPA water and 1 scrambled egg labeled with 99mTc-labelled sulphur colloid; in the second group (G II) 12 volunteers were given the same meal but with 2 labeled eggs in order to increase the caloric content of the solid phase meal. Simultaneous anterior and posterior images were recorded using a dual-headed gamma camera. Solid and liquid geometric mean data were analyzed to determine the lag phase, the emptying rate and the half-emptying time for both solids and liquids. Solid and liquid gastric half-emptying times were significantly prolonged in G II compared to G I volunteers. For the solid phased, the delay was accounted for by a longer lag phase and a decrease in the equilibrium emptying rate. The emptying rate of the liquid phase was significantly decreased in G II compared to G I. Within each group, no statistically significant difference was observed between solid and liquid emptying rates. We conclude that the caloric content of the solid portion of a meal not only alters the emptying of the solid phase but also affects the emptying of the liquid component of the meal.

Gastric emptying after artificial ulceration in rats: differences due to the site of the ulcer and the effects of prokinetic drugs.

PubMed

Uchida, Masayuki; Kobayashi, Orie; Shimizu, Kimiko

2017-01-01

Background This study aimed to evaluate the effects of the position of an acetic acid-induced gastric ulcer and the effects of prokinetic drugs on gastric emptying. Materials and Methods Male Sprague-Dawley rats were used in this study. Acetic acid ulcers were induced either in the region between the fundus and pylorus on the anterior wall of the stomach or in the glandular region on the greater curvature of the stomach to determine whether there were regional differences in the effect of the ulcers. Gastric emptying was evaluated with a breath test using [1- 13 C] acetic acid. In addition, the effects of the prokinetic drugs, metoclopramide and mosapride, on gastric emptying were also evaluated. Results Acetic acid induced ulcers in the region between the fundus and pylorus on the anterior wall of the stomach significantly delayed gastric emptying as compared with control rats, but not the acetic acid induced ulcers in the glandular region on the greater curvature of the stomach. Metoclopramide and mosapride did not improve the delayed gastric emptying even at doses that enhanced gastric emptying in normal rats. Conclusion These findings show that gastric emptying is influenced by the position of the ulcer and the region between the fundus and pylorus on the anterior wall plays an important role in gastric emptying. Moreover, it was found that metoclopramide and mosapride do not improve the delayed gastric emptying caused by acetic acid ulcers induced on the anterior wall in the region between the fundus and pylorus.

Gastric emptying after artificial ulceration in rats: differences due to the site of the ulcer and the effects of prokinetic drugs

PubMed Central

Uchida, Masayuki; Kobayashi, Orie; Shimizu, Kimiko

2017-01-01

Abstract Background This study aimed to evaluate the effects of the position of an acetic acid-induced gastric ulcer and the effects of prokinetic drugs on gastric emptying. Materials and Methods Male Sprague-Dawley rats were used in this study. Acetic acid ulcers were induced either in the region between the fundus and pylorus on the anterior wall of the stomach or in the glandular region on the greater curvature of the stomach to determine whether there were regional differences in the effect of the ulcers. Gastric emptying was evaluated with a breath test using [1-13C] acetic acid. In addition, the effects of the prokinetic drugs, metoclopramide and mosapride, on gastric emptying were also evaluated. Results Acetic acid induced ulcers in the region between the fundus and pylorus on the anterior wall of the stomach significantly delayed gastric emptying as compared with control rats, but not the acetic acid induced ulcers in the glandular region on the greater curvature of the stomach. Metoclopramide and mosapride did not improve the delayed gastric emptying even at doses that enhanced gastric emptying in normal rats. Conclusion These findings show that gastric emptying is influenced by the position of the ulcer and the region between the fundus and pylorus on the anterior wall plays an important role in gastric emptying. Moreover, it was found that metoclopramide and mosapride do not improve the delayed gastric emptying caused by acetic acid ulcers induced on the anterior wall in the region between the fundus and pylorus. PMID:28652516

Novel method to assess gastric emptying in humans: the Pellet Gastric Emptying Test

NASA Technical Reports Server (NTRS)

Choe, S. Y.; Neudeck, B. L.; Welage, L. S.; Amidon, G. E.; Barnett, J. L.; Amidon, G. L.

2001-01-01

To further validate the Pellet Gastric Emptying Test (PGET) as a marker of gastric emptying, a randomized, four-way crossover study was conducted with 12 healthy subjects. The study consisted of oral co-administration of enteric coated caffeine (CAFF) and acetaminophen (APAP) pellets in four treatment phases: Same Size (100 kcal), Fasted, Small Liquid Meal (100 kcal), and Standard Meal (847 kcal). The time of first appearance of measurable drug marker in plasma, t(initial), was taken as the emptying time for the markers. Co-administration of same size enteric coated pellets of CAFF and APAP (0.7 mm in diameter) revealed no statistically significant differences in t(initial) values indicating that emptying was dependent only on size and not on chemical make-up of the pellets. Co-administration of different size pellets indicated that the smaller 0.7-mm diameter (CAFF) pellets were emptied and absorbed significantly earlier than the larger 3.6-mm diameter (APAP) pellets with both the Small Liquid Meal (by 35 min) and the Standard Meal (by 33 min) (P<0.05). The differences in emptying of the pellets were not significant in the Fasted Phase. The results suggest that the pellet gastric emptying test could prove useful in monitoring changes in transit times in the fasted and fed states and their impact on drug absorption.

Calories and gastric emptying: a regulatory capacity with implications for feeding.

PubMed

McHugh, P R; Moran, T H

1979-05-01

Gastric emptying in four unanesthetized male Macaca mulatta was studied with the serial test meal method of Hunt and Spurrell. Liquid meals were infused into the stomach through a chronic indwelling Silastic cannula. Saline meals empty rapidly and exponentially. Doubling the volume of saline from 150 to 300 ml increased the emptying rate so that the half-life remained unchanged (15 min). The 150-ml glucose meals (0.05, 0.125, and 0.25 g/ml) emptied more slowly than saline, progressively more slowly with increasing concentrations (0.05--1.8, 0.125--0.78, and 0.25--0.37 ml/min) and linearly through most of their course. Doubling the volume of 0.125 g/ml-glucose meal did not change the rate of emptying. Converting grams of glucose to their caloric content, the emptying rate in kcal/min becomes constant (approx 0.4 kcal/min) in this range of concentrations. Isocaloric casein hydrolysate and medium-chain triglyceride oil meals at 0.5 kcal/ml empty at the same rate as glucose. The precision of this regulation is sufficient to give it a role in preabsorptive satiety and the control of caloric intake.

Spatial games with cyclic interactions: the response of empty sites

NASA Astrophysics Data System (ADS)

Brown, Bart; Pleimling, Michel

2015-03-01

Predator-prey models of the May-Leonard family employ empty sites in a spatial setting as an intermediate step in the reproduction process. This requirement makes the number and arrangement of empty sites important to the formation of space-time patterns. We study the density of empty sites in a stochastic predator-prey model in which the species compete in a cyclic way in two dimensions. In some cases systems of this type quickly form domains of neutral species after which all predation, and therefore, reproduction occur near the interface of competing domains. Using Monte Carlo simulations we investigate the relationship of this density of empty sites to the time-dependent domain length. We further explore the dynamics by introducing perturbations to the interaction rates of the system after which we measure the perturbed density, i.e. the response of empty sites, as the system relaxes. A dynamical scaling behavior is observed in the response of empty sites. This work is supported by the US National Science Foundation through Grant DMR-1205309.

Aldioxa improves delayed gastric emptying and impaired gastric compliance, pathophysiologic mechanisms of functional dyspepsia

PubMed Central

Asano, Teita; Aida, Shuji; Suemasu, Shintaro; Tahara, Kayoko; Tanaka, Ken-ichiro; Mizushima, Tohru

2015-01-01

Delayed gastric emptying and impaired gastric accommodation (decreased gastric compliance) play important roles in functional dyspepsia (FD). Here we screen for a clinically used drug with an ability to improve delayed gastric emptying in rats. Oral administration of aldioxa (dihydroxyaluminum allantoinate) partially improved clonidine- or restraint stress-induced delayed gastric emptying. Administration of allantoin, but not aluminium hydroxide, restored the gastric emptying. Both aldioxa and allantoin inhibited clonidine binding to the α-2 adrenergic receptor, suggesting that antagonistic activity of the allantoin moiety of aldioxa on this receptor is involved in the restoration of gastric emptying activity. Aldioxa or aluminium hydroxide but not allantoin restored gastric compliance with restraint stress, suggesting that aluminium hydroxide moiety is involved in this restoration. We propose that aldioxa is a candidate drug for FD, because its safety in humans has already been confirmed and its ameliorating effect on both of delayed gastric emptying and impaired gastric compliance are confirmed here. PMID:26620883

How often do fishes "run on empty"?

USGS Publications Warehouse

Arrington, D.A.; Winemiller, K.O.; Loftus, W.F.; Akin, S.

2002-01-01

We used a large data set of African, Neotropical, and North American fishes to examine the frequency with which fishes have empty stomachs (nspecies = 254; nindividuals = 36875). Mean percentage of empty stomachs was low across all fishes (16.2 ?? 1.2%) but varied from 0% to 79.4% among individual species. Nocturnal fishes had empty stomachs more frequently than diurnal fishes. Trophic classification was strongly associated with the percentage of empty stomachs, a pattern also revealed from an intraspecific analysis. Fishes appear to adjust their feeding intervals relative to the energy density, conversion efficiency, and particle size of their food. Piscivorous fishes seem to be the only trophic group that regularly experience long periods of empty stomachs, with species that consume prey whole and those that provide extended parental care having the highest proportions of empty stomachs. Activity patterns and life histories of some piscivorous species probably have evolved in partial response to energetic benefits of large, energy-rich food resources.

Effect of guar gum on hunger and satiety after meals of differing fat content: relationship with gastric emptying.

PubMed

French, S J; Read, N W

1994-01-01

To determine whether the satiating effects of fiber are due to delaying gastric emptying or slowing absorption of meals, 3% guar gum was added to high- and low-fat soups and gastric emptying rate, hunger, and satiety were measured in eight male volunteers. Guar gum delayed the emptying of the low-fat soup but the small delays in the return of hunger and decline of fullness were significantly correlated with the gastric emptying, suggesting mediation by gastric mechanoreceptors. The high-fat soup also emptied more slowly but this had no effect on the return of hunger or the decline in fullness. The delays in the return of hunger and decline of fullness were far greater when guar gum was added to the fatty soup; these delays were not correlated with the small additional delay in gastric emptying. This is more compatible with slowed absorption and prolonged contact of nutrients with intestinal chemoreceptors.

Principles of an enhanced MBR-process with mechanical cleaning.

PubMed

Rosenberger, S; Helmus, F P; Krause, S; Bareth, A; Meyer-Blumenroth, U

2011-01-01

Up to date, different physical and chemical cleaning protocols are necessary to limit membrane fouling in membrane bioreactors. This paper deals with a mechanical cleaning process, which aims at the avoidance of hypochlorite and other critical chemicals in MBR with submerged flat sheet modules. The process basically consists of the addition of plastic particles into the loop circulation within submerged membrane modules. Investigations of two pilot plants are presented: Pilot plant 1 is equipped with a 10 m(2) membrane module and operated with a translucent model suspension; pilot plant 2 is equipped with four 50 m(2) membrane modules and operated with pretreated sewage. Results of pilot plant 1 show that the establishment of a fluidised bed with regular particle distribution is possible for a variety of particles. Particles with maximum densities of 1.05 g/cm(3) and between 3 and 5 mm diameter form a stable fluidised bed almost regardless of activated sludge concentration, viscosity and reactor geometry. Particles with densities between 1.05 g/cm(3) and 1.2 g/cm(3) form a stable fluidised bed, if the velocity at the reactor bottom is sufficiently high. Activities within pilot plant 2 focused on plant optimisation and the development of an adequate particle retention system.

The effects of cholelithiasis and cholecystectomy on gastric emptying.

PubMed

Köksoy, F N; Bulut, T; Köse, H; Soybir, G; Yalçin, O; Aker, Y

In this clinical study, four groups, each consisting of 12 patients are established to determine how gastric emptying is influenced in cholelithiasis with accompanied flatulent dyspepsia and the relationship of symptoms and gastric emptying after cholecystectomy. 1. group: healthy people, 2. group: patients with dyspeptic cholelithiasis, 3. group: patients who have no dyspepsia after cholecystectomy, 4. group: patients whose dyspepsia is continued after cholecystectomy. Groups are compared according to solid phase gastric emptying scintigraphies performed with Tc 99m sulfur colloid bound with scrambled eggs. Gastric emptying delayed in second (p < 0.001) and fourth (p < 0.005) groups postprandially and not differed in the third group (p > 0.005). These results demonstrate that dyspepsia, in cholelithiasis and persisting after cholecystectomy have a close relation with delay in gastric emptying.

Effects of cholelithiasis and cholecystectomy on gastric emptying.

PubMed

Köksoy, F N; Bulut, T; Köse, H; Soybir, G; Yalçin, O; Aker, Y

1994-06-01

In this prospective, clinical study, four groups, each consisting of 12 patients were established to determine how gastric emptying is influenced in cholelithiasis with accompanied flatulent dyspepsia and the relationship of symptoms and gastric emptying after cholecystectomy: group 1--healthy people; group 2--patients with dyspeptic cholelithiasis; group 3--patients with no dyspepsia after cholecystectomy; group 4--patients with dyspepsia after cholecystectomy. Groups are compared according to solid phase gastric emptying scintigraphies performed with Tc 99m sulphur colloid bound with scrambled eggs. Gastric emptying delayed in groups 2 (P < 0.001) and 4 (P < 0.005) postprandially and did not differ in the group 3 (P > 0.005). These results demonstrate that dyspepsia, in cholelithiasis and persisting after cholecystectomy, has a close relation with delay in gastric emptying.

Transport and abatement of fluorescent silica nanoparticle (SiO2 NP) in granular filtration: effect of porous media and ionic strength

NASA Astrophysics Data System (ADS)

Zeng, Chao; Shadman, Farhang; Sierra-Alvarez, Reyes

2017-03-01

The extensive production and application of engineered silica nanoparticles (SiO2 NPs) will inevitably lead to their release into the environment. Granular media filtration, a widely used process in water and wastewater treatment plants, has the potential for NP abatement. In this work, laboratory-scale column experiments were performed to study the transport and retention of SiO2 NPs on three widely used porous materials, i.e., sand, anthracite, and granular activated carbon (GAC). Synthetic fluorescent core-shell SiO2 NPs (83 nm) were used to facilitate NP detection. Sand showed very low capacity for SiO2 filtration as this material had a surface with limited surface area and a high concentration of negative charge. Also, we found that the stability and transport of SiO2 NP were strongly dependent on the ionic strength of the solution. Increasing ionic strength led to NP agglomeration and facilitated SiO2 NP retention, while low ionic strength resulted in release of captured NPs from the sand bed. Compared to sand, anthracite and GAC showed higher affinity for SiO2 NP capture. The superior capacity of GAC was primarily due to its porous structure and high surface area. A process model was developed to simulate NP capture in the packed bed columns and determine fundamental filtration parameters. This model provided an excellent fit to the experimental data. Taken together, the results obtained indicate that GAC is an interesting material for SiO2 NP filtration.

Intraperitoneal delivery of platinum with in-situ crosslinkable hyaluronic acid gel for local therapy of ovarian cancer

PubMed Central

Cho, Eun Jung; Sun, Bo; Doh, Kyung-Oh; Wilson, Erin M.; Torregrosa-Allen, Sandra; Elzey, Bennett D.; Yeo, Yoon

2014-01-01

Intraperitoneal (IP) chemotherapy is a promising post-surgical therapy of solid carcinomas confined within the peritoneal cavity, with potential benefits in locoregional and systemic management of residual tumors. In this study, we intended to increase local retention of platinum in the peritoneal cavity over a prolonged period of time using a nanoparticle form of platinum and an in-situ crosslinkable hyaluronic acid gel. Hyaluronic acid was chosen as a carrier due to the biocompatibility and biodegradability. We confirmed a sustained release of platinum from the nanoparticles (PtNPs) and nanoparticle/gel hybrid (PtNP/gel), receptor-mediated endocytosis of PtNPs, and retention of the gel in the peritoneal cavity over 4 weeks--conditions desirable for a prolonged local delivery of platinum. However, PtNPs and PtNP/gel did not show a greater anti-tumor efficacy than CDDP solution administered at the same dose but rather caused a slight increase in tumor burdens at later time points, which suggests a potential involvement of empty carriers and degradation products in the growth of residual tumors. This study alerts that although several materials considered biocompatible and safe are used as drug carriers, they may have unwanted biological effects on the residual targets once the drug is exhausted; therefore, more attention should be paid to the selection of the drug carriers. PMID:25453960

Local behavioral rules sustain the cell allocation pattern in the combs of honey bee colonies (Apis mellifera).

PubMed

Montovan, Kathryn J; Karst, Nathaniel; Jones, Laura E; Seeley, Thomas D

2013-11-07

In the beeswax combs of honey bees, the cells of brood, pollen, and honey have a consistent spatial pattern that is sustained throughout the life of a colony. This spatial pattern is believed to emerge from simple behavioral rules that specify how the queen moves, where foragers deposit honey/pollen and how honey/pollen is consumed from cells. Prior work has shown that a set of such rules can explain the formation of the allocation pattern starting from an empty comb. We show that these rules cannot maintain the pattern once the brood start to vacate their cells, and we propose new, biologically realistic rules that better sustain the observed allocation pattern. We analyze the three resulting models by performing hundreds of simulation runs over many gestational periods and a wide range of parameter values. We develop new metrics for pattern assessment and employ them in analyzing pattern retention over each simulation run. Applied to our simulation results, these metrics show alteration of an accepted model for honey/pollen consumption based on local information can stabilize the cell allocation pattern over time. We also show that adding global information, by biasing the queen's movements towards the center of the comb, expands the parameter regime over which pattern retention occurs. © 2013 Published by Elsevier Ltd. All rights reserved.

Intraperitoneal delivery of platinum with in-situ crosslinkable hyaluronic acid gel for local therapy of ovarian cancer.

PubMed

Cho, Eun Jung; Sun, Bo; Doh, Kyung-Oh; Wilson, Erin M; Torregrosa-Allen, Sandra; Elzey, Bennett D; Yeo, Yoon

2015-01-01

Intraperitoneal (IP) chemotherapy is a promising post-surgical therapy of solid carcinomas confined within the peritoneal cavity, with potential benefits in locoregional and systemic management of residual tumors. In this study, we intended to increase local retention of platinum in the peritoneal cavity over a prolonged period of time using a nanoparticle form of platinum and an in-situ crosslinkable hyaluronic acid gel. Hyaluronic acid was chosen as a carrier due to the biocompatibility and biodegradability. We confirmed a sustained release of platinum from the nanoparticles (PtNPs) and nanoparticle/gel hybrid (PtNP/gel), receptor-mediated endocytosis of PtNPs, and retention of the gel in the peritoneal cavity over 4 weeks: conditions desirable for a prolonged local delivery of platinum. However, PtNPs and PtNP/gel did not show a greater anti-tumor efficacy than CDDP solution administered at the same dose but rather caused a slight increase in tumor burdens at later time points, which suggests a potential involvement of empty carriers and degradation products in the growth of residual tumors. This study alerts that although several materials considered biocompatible and safe are used as drug carriers, they may have unwanted biological effects on the residual targets once the drug is exhausted; therefore, more attention should be paid to the selection of drug carriers. Copyright © 2014 Elsevier Ltd. All rights reserved.

Water retention curves and thermal insulating properties of Thermosand

NASA Astrophysics Data System (ADS)

Leibniz, Otto; Winkler, Gerfried; Birk, Steffen

2010-05-01

The heat loss and the efficiency of isolating material surrounding heat supply pipes are essential issues for the energy budget of heat supply pipe lines. Until now heat loss from the pipe is minimized by enlarging the polyurethane (PU) - insulation thickness around the pipe. As a new approach to minimize the heat loss a thermally insulating bedding material was developed and investigated. Conventional bedding sands cover all necessary soil mechanical properties, but have a high thermal conductivity from λ =1,5 to 1,7 W/(m K). A newly developed embedding material 'Thermosand' shows thermal properties from λ=0,18 W/(m K) (dry) up to 0,88 W/(m K) (wet). The raw material originates from the waste rock stockpiles of a coal mine near Fohnsdorf, Austria. With high temperatures up to nearly 1000 ° C and a special mineral mixture, a natural burned reddish material resembling clinker arises. The soilmechanical properties of Thermosand has been thoroughly investigated with laboratory testing and in situ investigations to determine compaction-, permeability- and shear-behaviour, stiffness and corresponding physical parameters. Test trenches along operational heat pipes with temperature-measurement along several cross-sections were constructed to compare conventional embedding materials with 'Thermosand'. To investigate the influence of varying moisture content on thermal conductivity a 1:1 large scale model test in the laboratory to simulate real insitu-conditions was established. Based on this model it is planned to develop numerical simulations concerning varying moisture contents and unsaturated soil mechanics with heat propagation, including the drying out of the soil during heat input. These simulations require the knowledge about the water retention properties of the material. Thus, water retention curves were measured using both steady-state tension and pressure techniques and the simplified evaporation method. The steady-state method employs a tension table (sand box) at tensions below 100 hPa and a pressure extractor at tensions between 300 hPa and 15,000 hPa; the water content is measured by weighing after the sample has equilibrated at the tension value set on the table or plate. In the transient evaporation method two tensiometers with a measurement range between 0 and 850 hPa are installed at a depth of 1.25 cm and 3.75 cm in a sample of 5 cm in height; the mean values of the two tensiometers and the water contents measured by weighting are used to obtain the water retention curve. First results of both methods show that the Thermosand samples release water over the entire tension range measured above 10 hPa. Because of the limited measurement range of the tensiometers used for the evaporation method, the measured curve must be extrapolated between 850 hPa and 15,000 hPa, to allow comparison with the steady-state method. To this end, it was attempted to match the Van-Genuchten and a bimodal Van-Genuchten retention function to the data from the evaporation experiments. This involves a simultaneous fit of both the water-retention and the hydraulic-conductivity function. As one first result only the Van-Genuchten model was found to be able to produce satisfactorily fits to the data. The extrapolated water retention curves (above 850 hPa) however do not match the data from the steady-state method. This suggests that alternative soil hydraulic functions are needed to provide an adequate representation of the water retention characteristics of the Thermosand. It has to be considered that especially for the heat flow simulation water retention and hydraulic conductivity functions above 15,000 hPa have to be determined.

Influence of carrier filling ratio on the performance of moving bed biofilm reactor in treating coking wastewater.

PubMed

Gu, Qiyuan; Sun, Tichang; Wu, Gen; Li, Mingyue; Qiu, Wei

2014-08-01

This study aims to evaluate the effect of carrier filling ratio on the performance of a moving bed biofilm reactor in degrading chemical oxygen demand, phenol, thiocyanate, and ammonia from coking wastewater at 20h of hydraulic retention time. The operational experiments under different carrier filling ratios ranging from 20% to 60% were investigated. The maximum removal efficiency of 89%, 99% and 99% for COD, phenol and thiocyanate, and minimum sensitivity to the increasing contaminants concentration in the influent were achieved at 50% carrier filling ratio. The Haldane competitive substrate inhibition kinetics model was used to describe the relationship between the oxygen uptake rate of ammonium oxidizers and the concentration of free ammonium. The highest biofilm microbial community functional diversity (Shannon's diversity index, H') and evenness (Shannon's evenness index, E') were obtained at 50% carrier filling ratio in all runs using a Biolog ECO microplate. Copyright © 2014 Elsevier Ltd. All rights reserved.

Prediction of moving bed biofilm reactor (MBBR) performance for the treatment of aniline using artificial neural networks (ANN).

PubMed

Delnavaz, M; Ayati, B; Ganjidoust, H

2010-07-15

In this study, the results of 1-year efficiency forecasting using artificial neural networks (ANN) models of a moving bed biofilm reactor (MBBR) for a toxic and hard biodegradable aniline removal were investigated. The reactor was operated in an aerobic batch and continuous condition with 50% by volume which was filled with light expanded clay aggregate (LECA) as carrier. Efficiency evaluation of the reactors was obtained at different retention time (RT) of 8, 24, 48 and 72 h with an influent COD from 100 to 4000 mg/L. Exploratory data analysis was used to detect relationships between the data and dependent evaluated one. The appropriate architecture of the neural network models was determined using several steps of training and testing of the models. The ANN-based models were found to provide an efficient and a robust tool in predicting MBBR performance for treating aromatic amine compounds. 2010 Elsevier B.V. All rights reserved.

Comparative analysis of the bacterial diversity in a lab-scale moving bed biofilm reactor (MBBR) applied to treat urban wastewater under different operational conditions.

PubMed

Calderón, Kadiya; Martín-Pascual, Jaime; Poyatos, José Manuel; Rodelas, Belén; González-Martínez, Alejandro; González-López, Jesús

2012-10-01

Different types of carriers were tested as support material in a lab-scale moving bed biofilm reactor (MBBR) used to treat urban wastewater under three different conditions of hydraulic retention time (HRT) and carrier filling ratios (FR). The bacterial diversity developed on the biofilms responsible of the treatment was studied using a cultivation-independent approach based on the polymerase chain reaction-temperature gradient gel electrophoresis technique (PCR-TGGE). Cluster analysis of TGGE fingerprints showed significant differences of community structure dependent upon the different operational conditions applied. Redundancy analysis (RDA) was used to determine the relationship between the operational conditions (type of carrier, HRT, FR) and bacterial biofilm diversity, demonstrating a significant effect of FR=50%. Phylogenetic analysis of PCR-reamplified and sequenced TGGE bands revealed that the prevalent Bacteria populations in the biofilm were related to Betaproteobacteria (46%), Firmicutes (34%),Alphaproteobacteria (14%) and Gammaproteobacteria (9%). Copyright © 2012 Elsevier Ltd. All rights reserved.

Utilization of moving bed biofilm reactor for industrial wastewater treatment containing ethylene glycol: kinetic and performance study.

PubMed

Hassani, Amir Hessam; Borghei, Seyed Mehdi; Samadyar, Hassan; Ghanbari, Bastam

2014-01-01

One of the requirements for environmental engineering, which is currently being considered, is the removal of ethylene glycol (EG) as a hazardous environmental pollutant from industrial wastewater. Therefore, in a recent study, a moving bed biofilm reactor (MBBR) was applied at pilot scale to treat industrial effluents containing different concentrations of EG (600, 800, 1200, and 1800 mg L-1 ). The removal efficiency and kinetic analysis of the system were examined at different hydraulic retention times of 6, 8, 10, and 12 h as well as influent chemical oxygen demand (COD) ranged between values of 1000 and 3000mg L-1. In minimum and maximum COD Loadings, the MBBR showed 95.1% and 60.7% removal efficiencies, while 95.9% and 66.2% EG removal efficiencies were achieved in the lowest and highest EG concentrations. The results of the reactor modelling suggested compliance of the well-known modified Stover-Kincannon model with the system.

Treatment of oilfield wastewater in moving bed biofilm reactors using a novel suspended ceramic biocarrier.

PubMed

Dong, Zhiyong; Lu, Mang; Huang, Wenhui; Xu, Xiaochun

2011-11-30

In this study, a novel suspended ceramic carrier was prepared, which has high strength, optimum density (close to water), and high porosity. Two different carriers, unmodified and sepiolite-modified suspended ceramic carriers were used to feed two moving bed biofilm reactors (MBBRs) with a filling fraction of 50% to treat oilfield produced water. The hydraulic retention time (HRT) was varied from 36 to 10h. The results, during a monitoring period of 190 days, showed that removal efficiency of chemical oxygen demand was the highest in reactor 3 filled with the sepiolite-modified carriers, followed by reactor 2 filled with the unmodified carriers, with the lowest in reactor 1 (activated sludge reactor), at an HRT of 10h. Similar trends were found in the removal efficiencies of ammonia nitrogen and polycyclic aromatic hydrocarbons. Reactor 3 was more shock resistant than reactors 2 and 1. The results indicate that the suspended ceramic carrier is an excellent MBBR carrier. Copyright © 2011 Elsevier B.V. All rights reserved.

Fungal solid state fermentation on agro-industrial wastes for acid wastewater decolorization in a continuous flow packed-bed bioreactor.

PubMed

Iandolo, Donata; Amore, Antonella; Birolo, Leila; Leo, Gabriella; Olivieri, Giuseppe; Faraco, Vincenza

2011-08-01

This study was aimed at developing a process of solid state fermentation (SSF) with the fungi Pleurotus ostreatus and Trametes versicolor on apple processing residues for wastewater decolorization. Both fungi were able to colonize apple residues without any addition of nutrients, material support or water. P. ostreatus produced the highest levels of laccases (up to 9U g(-1) of dry matter) and xylanases (up to 80U g(-1) of dry matter). A repeated batch decolorization experiment was set up with apple residues colonized by P. ostreatus, achieving 50% decolorization and 100% detoxification after 24h, and, adding fresh wastewater every 24h, a constant decolorization of 50% was measured for at least 1 month. A continuous decolorization experiment was set up by a packed-bed reactor based on colonized apple residues achieving a performance of 100mg dye L(-1)day(-1) at a retention time of 50h. Copyright © 2011 Elsevier Ltd. All rights reserved.

High-efficiency treatment of PTA wastewater using a biogas jet assisted anaerobic fluidized bed reactor.

PubMed

Zhang, Wei; Feng, Yangyang; Chen, Yingwen; Li, Peiwen; Zhu, Shemin; Shen, Shubao

2018-02-05

In this paper, a new type of biogas jet assisted anaerobic fluidized bed reactor loaded with a polypropylene carrier has been proposed. There was a clear improvement in the fluidized state due to the biogas assisted input when the gas/water ratio was set at 1:3 with a suitable carrier loading of 60%. When the circulating water flow is 30 L/min assisted with biogas 10 L/min, the mixing time shortens from 26 to 18 s. The performance of anaerobic biodegradation on wastewater treatment was improved largely. The chemical oxygen demand (COD) and terepthallic acid removal efficiencies were at 85.4% and 84%, respectively, at hydraulic retention time of 20 h, even when the influent COD concentration was as high as 4224 mg/L. In addition, plenty of microorganisms, attached to the carriers and assumed to be the reason behind the organic biodegradation efficiency of the proposed system, were observed using scanning electron microscopy.

A novel fast mass transfer anaerobic inner loop fluidized bed biofilm reactor for PTA wastewater treatment.

PubMed

Chen, Yingwen; Zhao, Jinlong; Li, Kai; Xie, Shitao

In this paper, a fast mass transfer anaerobic inner loop fluidized bed biofilm reactor (ILFBBR) was developed to improve purified terephthalic acid (PTA) wastewater treatment. The emphasis of this study was on the start-up mode of the anaerobic ILFBBR, the hydraulic loadings and the operation stability. The biological morphology of the anaerobic biofilm in the reactors was also analyzed. The anaerobic column could operate successfully for 46 days due to the pre-aerating process. The anaerobic column had the capacity to resist shock loadings and maintained a high stable chemical oxygen demand (COD) and terephthalic acid removal rates at a hydraulic retention time of 5-10 h, even under conditions of organic volumetric loadings as high as 28.8 kg COD·m(-3).d(-1). The scanning electron microscope analysis of the anaerobic carrier demonstrated that clusters of prokaryotes grew inside of pores and that the filaments generated by pre-aeration contributed to the anaerobic biofilm formation and stability.

Treating exhaust gas from a pressurized fluidized bed reaction system

DOEpatents

Isaksson, J.; Koskinen, J.

1995-08-22

Hot gases from a pressurized fluidized bed reactor system are purified. Under super atmospheric pressure conditions hot exhaust gases are passed through a particle separator, forming a filtrate cake on the surface of the separator, and a reducing agent--such as an NO{sub x} reducing agent (like ammonia)--is introduced into the exhaust gases just prior to or just after particle separation. The retention time of the introduced reducing agent is enhanced by providing a low gas velocity (e.g. about 1--20 cm/s) during passage of the gas through the filtrate cake while at super atmospheric pressure. Separation takes place within a distinct pressure vessel, the interior of which is at a pressure of about 2--100 bar, and introduction of reducing agent can take place at multiple locations (one associated with each filter element in the pressure vessel), or at one or more locations just prior to passage of clean gas out of the pressure vessel (typically passed to a turbine). 8 figs.

Treating exhaust gas from a pressurized fluidized bed reaction system

DOEpatents

Isaksson, Juhani; Koskinen, Jari

1995-01-01

Hot gases from a pressurized fluidized bed reactor system are purified. Under superatmospheric pressure conditions hot exhaust gases are passed through a particle separator, forming a flitrate cake on the surface of the separator, and a reducing agent--such as an NO.sub.x reducing agent (like ammonia), is introduced into the exhaust gases just prior to or just after particle separation. The retention time of the introduced reducing agent is enhanced by providing a low gas velocity (e.g. about 1-20 cm/s) during passage of the gas through the filtrate cake while at superatmospheric pressure. Separation takes place within a distinct pressure vessel the interior of which is at a pressure of about 2-100 bar, and-introduction of reducing agent can take place at multiple locations (one associated with each filter element in the pressure vessel), or at one or more locations just prior to passage of clean gas out of the pressure vessel (typically passed to a turbine).

Biotransformation of ferulic acid to vanillin in the packed bed-stirred fermentors

PubMed Central

Yan, Lei; Chen, Peng; Zhang, Shuang; Li, Suyue; Yan, Xiaojuan; Wang, Ningbo; Liang, Ning; Li, Hongyu

2016-01-01

We performed the biotransformation of ferulic acid to vanillin using Bacillus subtilis (B. subtilis) in the stirring packed-bed reactors filled with carbon fiber textiles (CFT). Scanning electron microscope (SEM), HPLC, qRT-PCR and ATP assay indicated that vanillin biotransformation is tightly related to cell growth, cellar activity and the extent of biofilm formation. The biotransformation was affected by hydraulic retention time (HRT), temperature, initial pH, stirring speed and ferulic acid concentration, and the maximum vanillin production was obtained at 20 h, 35 °C, 9.0, 200 rpm, 1.5 g/L, respectively. Repeated batch biotransformation performed under this optimized condition showed that the maximum productivity (0.047 g/L/h) and molar yield (60.43%) achieved in immobilized cell system were 1.84 and 3.61 folds higher than those achieved in free cell system. Therefore, the stirring reactor packed with CFT carrier biofilm formed by B. subtilis represented a valid biocatalytic system for the production of vanillin. PMID:27708366

The role of mast cell stabilization in treatment of postoperative ileus: a pilot study.

PubMed

The, Frans O; Buist, Marrije R; Lei, Aaltje; Bennink, Roelof J; Hofland, Jan; van den Wijngaard, René M; de Jonge, Wouter J; Boeckxstaens, Guy E

2009-09-01

Although postoperative ileus (POI) is considered multifactorial, intestinal inflammation resulting from manipulation-induced mast cell activation is recognized as an important pathophysiological mechanism. Therefore, mast cell stabilization may represent a new therapeutic approach to shortening POI. The aim of this paper was to study the effect of ketotifen, a mast cell stabilizer, on postoperative gastrointestinal transit in patients who underwent abdominal surgery. In this pilot study, 60 patients undergoing major abdominal surgery for gynecological malignancy with standardized anesthesia were randomized to treatment with ketotifen (4 or 12 mg) or placebo. Patients were treated for 6 days, starting 3 days before surgery. Gastric emptying of liquids, selected as a primary outcome parameter, was measured 24 h after surgery using scintigraphy. Secondary end points were (scintigraphically assessed) colonic transit, represented as geometrical center of activity (segment 1(cecum) to 7(stool)) and clinical parameters. Gastric retention 1 h after liquid intake was significantly reduced by 12 mg (median 3% (1-7), P=0.01), but not by 4 mg ketotifen (18% (3-45), P=0.6) compared with placebo (16% (5-75)). Twenty-four hour colonic transit in placebo was 0.8 (0.0-1.1) vs. 1.2 (0.2-1.4) colon segments in the 12 mg ketotifen group (P=0.07). Abdominal cramps were significantly relieved in patients treated with 12 mg ketotifen, whereas other clinical parameters were not affected. Ketotifen significantly improves gastric emptying after abdominal surgery and warrants further exploration of mast cell stabilizers as putative therapy for POI.

The path of placement of a removable partial denture: a microscope based approach to survey and design

PubMed Central

2015-01-01

This article reviews the topic of how to identify and develop a removable partial denture (RPD) path of placement, and provides a literature review of the concept of the RPD path of placement, also known as the path of insertion. An optimal RPD path of placement, guided by mutually parallel guide planes, ensures that the RPD flanges fit intimately over edentulous ridge structures and that the framework fits intimately with guide plane surfaces, which prevents food collecting empty spaces between the intaglio surface of the framework and intraoral surfaces, and ensures that RPD clasps engage adequate numbers of tooth undercuts to ensure RPD retention. The article covers topics such as the causes of obstructions to RPD intra-oral seating, the causes of food collecting empty spaces that may exist around an RPD, and how to identify if a guide plane is parallel with the projected RPD path of placement. The article presents a method of using a surgical operating microscope, or high magnification (6-8x or greater) binocular surgical loupes telescopes, combined with co-axial illumination, to identify a preliminary path of placement for an arch. This preliminary path of placement concept may help to guide a dentist or a dental laboratory technician when surveying a master cast of the arch to develop an RPD path of placement, or in verifying that intra-oral contouring has aligned teeth surfaces optimally with the RPD path of placement. In dentistry, a well-fitting RPD reduces long-term periodontal or structural damage to abutment teeth. PMID:25722842

Isosorbide dinitrate and nifedipine treatment of achalasia: a clinical, manometric and radionuclide evaluation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gelfond, M.; Rozen, P.; Gilat, T.

1982-11-01

The effects of sublingual isosorbide dinitrate (5 mg) and nifedipine (20 mg) were compared in 15 patients with achalasia. The parameters examined included the manometric measurement of the lower esophageal sphincter pressure, the radionuclide assessment of esophageal emptying and the clinical response. The mean basal lower esophageal sphincter pressure fell significantly after both drugs (p less than 0.01), with a maximum fall of 63.5% 10 min after receiving isosorbide dinitrate, but by only 46.7% 30 min after nifedipine. The esophageal radionuclide test meal retention was significantly less (p less than 0.01) only after receiving isosorbide dinitrate. The drug improved initialmore » esophageal emptying by its effect on the lower esophageal sphincter and by relieving the test meal hold-up noted to occur at the junction of the upper and midesophagus. Eight patients cleared their test meal within 10 min after isosorbide dinitrate administration while only two did so after nifedipine. Subjectively, 13 patients had their dysphagia relieved by isosorbide dinitrate and 8 by nifedipine. However, this relief was not confirmed in 4 patients by the radionuclide study and they, as well as the other 3 patients who did not respond to therapy, were referred to pneumatic dilatation. Side effects were more prominent after nitrates. Three of the patients are currently receiving nifedipine and 5 patients received isosorbide dinitrate therapy for 8-14 mo. The radionuclide test meal is currently the best way of objectively evaluating drug therapy in patients with achalasia. Isosorbide dinitrate is more effective than nifedipine in relieving their symptoms.« less

Adsorption of (99m)Tc-radiopharmaceuticals onto injection vials and syringes.

PubMed

Mushtaq, Ahmad; Ur Rehman, Taj; Safdar Mansur, Muhammad; Jehangir, Mustanser

2008-06-01

Many groups have reported the adsorption or retention of (99m)Tc-radiopharmaceuticals on injection vials and disposable plastic syringes. Such an enormously high loss of radioactivity would result in poor images, radiation exposure, waste, and economic burdens. We therefore decided to investigate the extent of adsorption or retention of several (99m)Tc-radiopharmaceuticals on injection vials, rubber stoppers, and plastic syringes. These radiopharmaceuticals are produced as lyophilized kits in our department and supplied to various hospitals practicing nuclear medicine in Pakistan. A vial containing lyophilized material was reconstituted with 3 mL of freshly eluted Na(99m)TcO(4). A 1-mL aliquot of the resulting solution was withdrawn into a syringe at 0.25, 0.5, 1, 3, and 5 h after preparation. All preparations were stored at room temperature ( approximately 22 degrees C). After each withdrawal, the vial was reweighed and the activity remaining in the vial was measured using a radioisotope calibrator. The sample was reinjected into the vial. From the original weight and activity of solution in the vial, the initial activity per gram was calculated. From the weight and activity remaining in the vial after withdrawal of the sample, the activity per gram of the sample was calculated. From the difference between the initial activity per gram and the activity per gram of the sample, the percentage of (99m)Tc adsorbed on the vial was calculated. All preparations were kept in the syringe for 15 min, and the activity was measured before and after the syringe was emptied. The needle and plunger of the syringe were separated, and activity in the needle and plunger was also measured. The labeling efficiency of all radiopharmaceuticals used during these studies was more than 95%. In most cases, the activity of (99m)Tc found on the rubber stopper was less than 1%. Adsorption of (99m)Tc onto vials increased gradually with storage time. Adsorption was minimal at the initial stages, whereas maximum retention was noted after 5 h. Nearly 5% adsorption of activity was observed after 5 h of storage time on vials of sestamibi, mercaptoacetyltriglycine, dextran, ciprofloxacin, and dimercaptosuccinic acid (III and V). Retention of activity on needles ranged from 1% to 2% for all preparations studied. Plungers did not show any significant retention of radioactivity; in most cases, retention was less than 0.5%. The maximum retention of radioactivity on plastic syringe bodies was more than 3% for sestamibi, dimercaptosuccinic acid, dextran, pyrophosphate, and phytate. The results revealed that losses of radioactivity from (99m)Tc-radiopharmaceuticals in these objects (glass vial, rubber stopper, plastic syringes, plungers, and needles) are not alarming in our setup.

Do calories or osmolality determine gastric emptying

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shafer, R.B.; Levine, A.S.; Marlette, J.M.

1984-01-01

Recent animal studies suggest that gastric emptying is dependent on the caloric and osmotic content of the ingested food. These studies have involved intubation with infusion of liquid meals into the stomach. Scintigraphic methods, which are non-invasive and do not alter normal physiology, are now available for precise quantitation of gastric emptying. To study the role of calories and osmolality on gastric emptying, the authors employed a standardized /sup 99m/Tc-scrambled egg meal washed with 50 cc tap water in 10 normal human volunteers. A variety of simple and complex sugars, non-absorbable complex carbohydrate (polycose), medium chain fatty acid (MCFA) andmore » gluten were dissolved in water and ingested with the test meal. Each subject acted as his own control. Coefficient of variation in control tests in each subject 12 weeks apart was 9.9%. Results showed that incremental glucose (25-66 gm) produced a linear increase in gastric emptying (T/2 control 50 +- 3, 25 gm 60 +- 3, 50 gm 79 +- 3 and 66 gm 102 +- 3 minutes). 25 gm fructose (T/2 59 +- 3 minutes) and 25 gm polycose (T/2 59 +- 3 minutes) had similar effects to glucose. 25 gm sucrose and 25 gm gluten did not significantly differ from controls. MCFA had an effect similar to 50 gm glucose - suggesting that calories are important in gastric emptying. However, 25 gm xylose markedly prolonged gastric emptying to 80 +- 5 minutes. The rank order for osmolality for substances tested MCFA = gluten < polycose < polycose < fructose < sucrose = glucose < xylose defined no relationship to gastric emptying. The authors' results suggest that neither calories nor osmolality alone determine gastric emptying. A specific food does not necessarily have the same effect on gastric emptying in different individuals.« less

Association of empty nest with depressive symptom in a Chinese elderly population: A cross-sectional study.

PubMed

Zhai, Yujia; Yi, Huaiming; Shen, Wei; Xiao, Yuanyuan; Fan, Haixiao; He, Fan; Li, Fudong; Wang, Xinyi; Shang, Xiaopeng; Lin, Junfen

2015-11-15

Empty nest has been becoming the main family pattern among old people, and influencing the traditional family providing for the aged in China. This study aimed to investigate the association of empty nest with depressive symptom in a Chinese elderly population. Our study was based on the baseline investigation of Zhejiang Major Public Health Surveillance which was conducted in 2014. The final analyzed sample consisted of 9215 participants aged no less than 60 years. Subjects completed a questionnaire including demographic characteristics, living arrangements, behavioral risk factors, health status, subjective assessments, and Patient Health Questionnaire-9 scale. More than half of the participants were empty nest elders (57.4%). The overall prevalence of depressive symptom was 10.3%, while it was higher in empty nest group than in non-empty nest group (11.6% vs. 8.6%, P<0.001). A positive association was found between empty nest and depressive symptom, the OR (95%CI) was 1.223(1.045, 1.431). After stratified by gender/age/education level/employment status, this association was just prominent in participants of male, 70 years old and above, primary school education, and retirees. No matter living with spouse or living alone, empty nesters were more likely to have depressive symptoms than non-empty nesters. Cross-sectional study could not make a causation conclusion. The social supports of participants were not been investigated in detail. Empty nest elders, especially those who are male, 70 years old and above, primary school education, and retired, are more vulnerable to depressive symptom. Copyright © 2015 Elsevier B.V. All rights reserved.

Loneliness and depression among rural empty-nest elderly adults in Liuyang, China: a cross-sectional study

PubMed Central

Wang, Guojun; Hu, Mi; Xiao, Shui-yuan; Zhou, Liang

2017-01-01

Objective To compare loneliness, depressive symptoms and major depressive episodes between empty-nest and not-empty-nest older adults in rural areas of Liuyang city, Hunan, China. Methods A cross-sectional multi-stage random cluster survey was conducted from November 2011 to April 2012 in Liuyang, China. A total of 839 rural older residents aged 60 or above completed the survey (response rate 97.6%). In line with the definition of empty nest, 25 participants who had no children were excluded from the study, while the remaining 814 elderly adults with at least one child were included for analysis. Loneliness and depressive symptoms in rural elderly parents were assessed using the short-form UCLA Loneliness Scale (ULS-6) and the Geriatric Depression Scale (GDS). Major depressive episodes were diagnosed using the Structured Clinical Interview for DSM-IV (SCID-I). Results Significant differences were found between empty-nest and not-empty-nest older adults regarding loneliness (16.19±3.90 vs. 12.87±3.02, Cohen’s d=0.97), depressive symptoms (8.50±6.26 vs. 6.92±5.19, Cohen’s d=0.28) and the prevalence of major depressive episodes (10.1% vs. 4.6%) (all p<0.05). After controlling for demographic characteristics and physical disease, the differences in loneliness, depressive symptoms and major depressive episodes remained significant. Path analysis showed that loneliness mediated the relationship between empty-nest syndrome and depressive symptoms and major depressive episodes. Conclusion Loneliness and depression are more severe among empty-nest than not-empty-nest rural elderly adults. Loneliness was a mediating variable between empty-nest syndrome and depression. PMID:28988166

Gastric emptying of solids and liquids in obesity.

PubMed

Glasbrenner, B; Pieramico, O; Brecht-Krauss, D; Baur, M; Malfertheiner, P

1993-07-01

The purpose of this study was to determine whether obese patients have different rates of solid and liquid gastric emptying compared to healthy controls. Twenty-four obese patients (7 males, 17 females) were investigated prior to dietary restriction. The patients had a weight excess above ideal weight ranging from 25% to 216% (mean weight 118.1 +/- 6.5 kg). The control group consisted of 8 healthy subjects (4 males, 4 females), within 10% of the ideal weight. The solid phase of the test meal consisted of 40 g bread, 30 g ham, 10 g margarine, and two scrambled eggs labeled with 99mTc. For the liquid phase, 200 ml orange juice was labeled with 201Tl. Three-minute counts of both tracers were taken for 106 min using a large field-of-view gamma camera. In obese patients, a significantly shortened lag phase for the emptying of solids was observed (27.0 +/- 3.3 versus 38.4 +/- 4.1 min; P < 0.05). Half-emptying time (105.9 +/- 6.7 versus 100.7 +/- 5.7 min), emptying rate (0.60 +/- 0.04 versus 0.71 +/- 0.07%/min), and total emptying of solids (49.4 +/- 3.6 versus 50.5 +/- 5.0%) were not different from controls. Obese subjects had a trend to slowed liquid emptying (half-time 82.7 +/- 4.8 versus 69.9 +/- 6.9 min; emptying rate 0.59 +/- 0.03 versus 0.65 +/- 0.03%/min; total emptying 59.8 +/- 2.9 versus 66.0 +/- 3.3%), but this was not statistically significant. There was no correlation between weight or body surface area and rate of solid or liquid gastric emptying.(ABSTRACT TRUNCATED AT 250 WORDS)

Risk factors associated with delayed gastric emptying after subtotal gastrectomy with Billroth-I anastomosis using circular stapler for early gastric cancer patients.

PubMed

Kim, Ki Han; Kim, Min Chan; Jung, Ghap Joong

2012-11-01

Gastric surgery may potentiate delayed gastric emptying. Billroth I gastroduodenostomy using a circular stapler is the most preferable reconstruction method. The purpose of this study is to analyze the risk factors associated with delayed gastric emptying after radical subtotal gastrectomy with Billroth I anastomosis using a stapler for early gastric cancer. Three hundred and seventy-eight patients who underwent circular stapled Billroth I gastroduodenostomy after subtotal gastrectomy due to early gastric cancer were analyzed retrospectively. One hundred and eighty-two patients had Billroth I anastomosis using a 25 mm diameter circular stapler, and 196 patients had anastomosis with a 28 or 29 mm diameter circular stapler. Clinicopathological features and postoperative outcomes were evaluated and compared between the two groups. Delayed gastric emptying was diagnosed by symptoms and simple abdomen X-ray with or without upper gastrointestinal series or endoscopy. Postoperative delayed gastric emptying was found in 12 (3.2%) of the 378 patients. Among all the variables, distal margin and circular stapler diameter were significantly different between the cases with delayed gastric emptying and no delayed gastric emptying. There were statistically significant differences in sex, body mass index, comorbidity, complication, and operation type according to circular stapler diameter. In both univariate and multivariate logistic regression analyses, only the stapler diameter was found to be a significant factor affecting delayed gastric emptying (P = 0.040). In this study, the circular stapler diameter was one of the most significant predictable factors of delayed gastric emptying for Billroth I gastroduodenostomy. The use of a 28 or 29 mm diameter circular stapler rather than a 25 mm diameter stapler in stapled gastroduodenostomy for early gastric cancer can reduce postoperative delayed gastric emptying associated with anastomosic stenosis or edema with relative safety.

Where are kids getting their empty calories? Stores, schools, and fast food restaurants each play an important role in empty calorie intake among US children in 2009-2010

PubMed Central

Poti, Jennifer M.; Slining, Meghan M.; Popkin, Barry M.; Kenan, W.R.

2013-01-01

Consumption of empty calories, the sum of energy from added sugar and solid fat, exceeds recommendations, but little is known about where US children obtain these empty calories. The objectives of this study were to compare children's empty calorie consumption from retail food stores, schools, and fast food restaurants; to identify food groups that were top contributors of empty calories from each location; and to determine the location providing the majority of calories for these key food groups. This cross-sectional analysis used data from 3,077 US children aged 2-18 years participating in the 2009-2010 National Health and Nutrition Examination Survey. The empty calorie content of children's intake from stores (33%), schools (32%), and fast food restaurants (35%) was not significantly different in 2009-2010. In absolute terms, stores provided the majority of empty calorie intake (436 kcal). The top contributors of added sugar and solid fat from each location were similar: sugar sweetened beverages (SSBs), grain desserts, and high-fat milk from stores; high-fat milk, grain desserts, and pizza from schools; and SSBs, dairy desserts, french fries, and pizza from fast food restaurants. Schools contributed about 20% of children's intake of high-fat milk and pizza. In conclusion, these findings support the need for continued efforts to reduce empty calorie intake among US children aimed not just at fast food restaurants, but also at stores and schools. The importance of reformed school nutrition standards was suggested, as prior to their implementation, schools resembled fast food restaurants in their contributions to empty calorie intake. PMID:24200654

Where are kids getting their empty calories? Stores, schools, and fast-food restaurants each played an important role in empty calorie intake among US children during 2009-2010.

PubMed

Poti, Jennifer M; Slining, Meghan M; Popkin, Barry M

2014-06-01

Consumption of empty calories, the sum of energy from added sugar and solid fat, exceeds recommendations, but little is known about where US children obtain these empty calories. The objectives of this study were to compare children's empty calorie consumption from retail food stores, schools, and fast-food restaurants; to identify food groups that were top contributors of empty calories from each location; and to determine the location providing the majority of calories for these key food groups. This cross-sectional analysis used data from 3,077 US children aged 2 to 18 years participating in the 2009-2010 National Health and Nutrition Examination Survey. The empty calorie content of children's intake from stores (33%), schools (32%), and fast-food restaurants (35%) was not significantly different in 2009-2010. In absolute terms, stores provided the majority of empty calorie intake (436 kcal). The top contributors of added sugar and solid fat from each location were similar: sugar-sweetened beverages, grain desserts, and high-fat milk∗ from stores; high-fat milk, grain desserts, and pizza from schools; and sugar-sweetened beverages, dairy desserts, french fries, and pizza from fast-food restaurants. Schools contributed about 20% of children's intake of high-fat milk and pizza. These findings support the need for continued efforts to reduce empty calorie intake among US children aimed not just at fast-food restaurants, but also at stores and schools. The importance of reformed school nutrition standards was suggested, as prior to implementation of these changes, schools resembled fast-food restaurants in their contributions to empty calorie intake. Copyright © 2014 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.

Research on strategy and optimization method of PRT empty vehicles resource allocation based on traffic demand forecast

NASA Astrophysics Data System (ADS)

Xiang, Yu; Tao, Cheng

2018-05-01

During the operation of the personal rapid transit system(PRT), the empty vehicle resources is distributed unevenly because of different passenger demand. In order to maintain the balance between supply and demand, and to meet the passenger needs of the ride, PRT empty vehicle resource allocation model is constructed based on the future demand forecasted by historical demand in this paper. The improved genetic algorithm is implied in distribution of the empty vehicle which can reduce the customers waiting time and improve the operation efficiency of the PRT system so that all passengers can take the PRT vehicles in the shortest time. The experimental result shows that the improved genetic algorithm can allocate the empty vehicle from the system level optimally, and realize the distribution of the empty vehicle resources reasonably in the system.

Analysis of empty ATLAS pilot jobs

NASA Astrophysics Data System (ADS)

Love, P. A.; Alef, M.; Dal Pra, S.; Di Girolamo, A.; Forti, A.; Templon, J.; Vamvakopoulos, E.; ATLAS Collaboration

2017-10-01

In this analysis we quantify the wallclock time used by short empty pilot jobs on a number of WLCG compute resources. Pilot factory logs and site batch logs are used to provide independent accounts of the usage. Results show a wide variation of wallclock time used by short jobs depending on the site and queue, and changing with time. For a reference dataset of all jobs in August 2016, the fraction of wallclock time used by empty jobs per studied site ranged from 0.1% to 0.8%. Aside from the wall time used by empty pilots, we also looked at how many pilots were empty as a fraction of all pilots sent. Binning the August dataset into days, empty fractions between 2% and 90% were observed. The higher fractions correlate well with periods of few actual payloads being sent to the site.

Involvement of endogenous opiates in regulation of gastric emptying of fat test meals in mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fioramonti, J.; Fargeas, M.J.; Bueno, L.

1988-08-01

The role of endogenous opioids and cholecystokinin (CCK) in gastric emptying was investigated in mice killed 30 min after gavage with /sup 51/Cr-radiolabeled liquid meals. The meals consisted of 0.5 ml of milk or one of five synthetic meals containing arabic gum, glucose and/or arachis oil and/or casein. Naloxone (0.1 mg/kg sc) significantly (P less than 0.01) accelerated gastric emptying of milk and meals containing fat but did not modify gastric emptying of nonfat meals. The CCK antagonist asperlicin (0.1 mg/kg ip) increased by 25% gastric emptying of milk. The gastric emptying of meals containing glucose and casein but notmore » fat was reduced after administration of the COOH-terminal octapeptide of cholecystokinin (CCK-8, 4 micrograms/kg ip). This decrease was antagonized by both asperlicin (10 mg/kg ip) and naloxone (0.1 mg/kg sc). Intracerebroventricular (icv) administration of an opiate antagonist that poorly crosses the blood-brain barrier, methyl levallorphan (10 micrograms/kg), did not modify gastric emptying of milk but accelerated it when peripherally administered (0.1 mg/kg sc). Similarly, asperlicin (icv) administered at a dose of 1 mg/kg did not affect milk emptying. These results indicate that endogenous opiates are involved at peripheral levels in the regulation of gastric emptying of fat meals only and that such regulation involves release of CCK.« less

Characterization of complete particles (VSV-G/SIN-GFP) and empty particles (VSV-G/EMPTY) in human immunodeficiency virus type 1-based lentiviral products for gene therapy: potential applications for improvement of product quality and safety.

PubMed

Zhao, Yuan; Keating, Kenneth; Dolman, Carl; Thorpe, Robin

2008-05-01

Lentiviral vectors persist in the host and are therefore ideally suited for long-term gene therapy. To advance the use of lentiviral vectors in humans, improvement of their production, purification, and characterization has become increasingly important and challenging. In addition to cellular contaminants derived from packaging cells, empty particles without therapeutic function are the major impurities that compromise product safety and efficacy. Removal of empty particles is difficult because of their innate similarity in particle size and protein composition to the complete particles. We propose that comparison of the properties of lentiviral products with those of purposely expressed empty particles may reveal potential differences between empty and complete particles. For this, three forms of recombinant lentiviral samples, that is, recombinant vesicular stomatitis virus glycoprotein (VSV-G) proteins, empty particles (VSV-G/Empty), and complete particles (VSV-G/SIN-GFP) carrying viral RNA, were purified by size-exclusion chromatography (SEC). The SEC-purified samples were further analyzed by immunoblotting with six antibodies to examine viral and cellular proteins associated with the particles. This study has demonstrated, for the first time, important differences between VSV-G/Empty particles and complete VSV-G/SIN-GFP particles. Differences include the processing of Gag protein and the inclusion of cellular proteins in the particles. Our findings support the development of improved production, purification, and characterization methods for lentiviral products.

Skin permeation and retention of topical bead formulation containing tranexamic acid.

PubMed

Vijayakumar, Ajay; Baskaran, Rengarajan; Yoo, Bong Kyu

2017-02-01

The objective of this study is to develop a topical bead formulation of tranexamic acid (TA) which can be used concomitantly with laser treatment. The bead formulation of TA (TAB) was successfully prepared by fluidized bed drying method. Physicochemical properties of the TAB were evaluated in terms of chemical stability of TA and differential scanning calorimetry. TA in the bead was stable up to six months at 25°C and existed as amorphous state. In vitro skin permeation and in vivo skin retention of TA in the beads were significantly higher compared to a commercial product. When the bead was dissolved into distilled water and applied concomitantly with laser treatment, the amount of TA retained in the skin in the in vivo study was inversely proportional to the energy levels of laser treatment, indicating absorption into subcutaneous tissue and drainage to systemic circulation. Therefore, when laser treatment is used concomitantly with TAB, energy level should be very carefully monitored to avoid possible adverse events associated with systemic side effects of TA.

Automatic high throughput empty ISO container verification

NASA Astrophysics Data System (ADS)

Chalmers, Alex

2007-04-01

Encouraging results are presented for the automatic analysis of radiographic images of a continuous stream of ISO containers to confirm they are truly empty. A series of image processing algorithms are described that process real-time data acquired during the actual inspection of each container and assigns each to one of the classes "empty", "not empty" or "suspect threat". This research is one step towards achieving fully automated analysis of cargo containers.

Comparative study of gastric emptying and nutritional status after pylorus-preserving vs. subtotal stomach-preserving pancreaticoduodenectomy.

PubMed

Hiyoshi, Masahide; Chijiiwa, Kazuo; Ohuchida, Jiro; Imamura, Naoya; Nagano, Motoaki

2012-06-01

Delayed gastric emptying (DGE) is a specific, worrisome complication after pancreaticoduodenectomy (PPPD), whereas subtotal stomach-preserving pancreaticoduodenectomy (SSPPD) that excises the pylorus ring seems to be effective in reducing DGE. This study compared gastric emptying and nutritional status between PPPD and SSPPD over 1 year. From June 2003 to December 2007, 41 patients (PPPD: 33, SSPPD: 8) were enrolled in this study to evaluate differences in gastric emptying and nutritional status at 1, 3, 6, 9 and 12 months after pancreaticoduodenectomy. Gastric emptying was evaluated by 13C-acetate breath test. Nutritional status (body weight, serum levels of total protein, albumin and total cholesterol) was similarly assessed. At 1 month, gastric emptying evaluated at T1/2 (half-emptying time) was significantly prolonged in the PPPD but not in the SSPPD compared to the preoperative level. Thereafter, T1/2 was decreased and showed function significantly better preserved at 3, 6 and 12 months after PPPD than after SSPPD. Body weight recovery was significantly better at 6 and 12 months after PPPD than after SSPPD. Other nutritional parameters were better preserved in the PPPD during 1-year follow-up. PPPD seems to be a more suitable surgical procedure than SSPPD in regard to gastric emptying and nutritional status.

Poly(iohexol) nanoparticles as contrast agents for in vivo X-ray computed tomography imaging.

PubMed

Yin, Qian; Yap, Felix Y; Yin, Lichen; Ma, Liang; Zhou, Qin; Dobrucki, Lawrence W; Fan, Timothy M; Gaba, Ron C; Cheng, Jianjun

2013-09-18

Biocompatible poly(iohexol) nanoparticles, prepared through cross-linking of iohexol and hexamethylene diisocyanate followed by coprecipitation of the resulting cross-linked polymer with mPEG-polylactide, were utilized as contrast agents for in vivo X-ray computed tomography (CT) imaging. Compared to conventional small-molecule contrast agents, poly(iohexol) nanoparticles exhibited substantially protracted retention within the tumor bed and a 36-fold increase in CT contrast 4 h post injection, which makes it possible to acquire CT images with improved diagnosis accuracy over a broad time frame without multiple administrations.

Common and Distinct Capsid and Surface Protein Requirements for Secretion of Complete and Genome-free Hepatitis B Virions.

PubMed

Ning, Xiaojun; Luckenbaugh, Laurie; Liu, Kuancheng; Bruss, Volker; Sureau, Camille; Hu, Jianming

2018-05-09

During the morphogenesis of hepatitis B virus (HBV), an enveloped virus, two types of virions are secreted: (1) a minor population of complete virions containing a mature nucleocapsid with the characteristic, partially double-stranded, relaxed circular DNA genome and (2) a major population containing an empty capsid with no DNA or RNA (empty virions). Secretion of both types of virions requires interactions between the HBV capsid or core protein (HBc) and the viral surface or envelope proteins. We have studied the requirements from both HBc and envelope proteins for empty virion secretion, in comparison with those for secretion of complete virions. Substitutions within the N-terminal domain of HBc that block secretion of DNA-containing virions reduced but did not prevent secretion of empty virions. The HBc C-terminal domain was not essential for empty virion secretion. Among the three viral envelope proteins, the smallest, S, alone was sufficient for empty virion secretion at a basal level. The largest protein, L, essential for complete virion secretion, was not required for, but could stimulate empty virion secretion. Also, substitutions in L that eliminate secretion of complete virions reduced but did not eliminate empty virion secretion. S mutations that block secretion of the hepatitis D virus (HDV), an HBV satellite, did not block secretion of either empty or complete HBV virions. Together, these results indicate that both common and distinct signals on empty capsids vs. mature nucleocapsids interact with the S and L proteins during the formation of complete vs. empty virions. IMPORTANCE Hepatitis B virus (HBV) is a major cause of severe liver diseases including cirrhosis and cancer. In addition to the complete infectious virion particle, which contains an outer envelope layer and an interior capsid that, in turn, encloses a DNA genome, HBV infected cells also secrete non-infectious, incomplete viral particles in large excess over the complete virions. In particular, the empty (or genome-free) virion share with the complete virion the outer envelope and interior capsid but contain no genome. We have carried out a comparative study on the capsid and envelope requirements for the secretion of these two types of virion particles and uncovered both shared and distinct determinants on the capsid and envelope for their secretion. These results provide new information on HBV morphogenesis, and have implications for efforts to develop empty HBV virions as a novel biomarker and a new generation of HBV vaccine. Copyright © 2018 American Society for Microbiology.

Performance evaluation of poly-urethane foam packed-bed chemical scrubber for the oxidative absorption of NH3 and H2S gases.

PubMed

Nisola, Grace M; Valdehuesa, Kris Niño G; Anonas, Alex V; Ramos, Kristine Rose M; Lee, Won-Keun; Chung, Wook-Jin

2018-01-02

The feasibility of open-pore polyurethane (PU) foam as packing material for wet chemical scrubber was tested for NH 3 and H 2 S removals. The foam is inexpensive, light-weight, highly porous (low pressure drop) and provides large surface area per unit volume, which are desirable properties for enhanced gas/liquid mass transfer. Conventional HCl/HOCl (for NH 3 ) and NaOH/NaOCl (for H 2 S) scrubbing solutions were used to absorb and oxidize the gases. Assessment of the wet chemical scrubbers reveals that pH and ORP levels are important to maintain the gas removal efficiencies >95%. A higher re-circulation rate of scrubbing solutions also proved to enhance the performance of the NH 3 and H 2 S columns. Accumulation of salts was confirmed by the gradual increase in total dissolved solids and conductivity values of scrubbing solutions. The critical elimination capacities at >95% gas removals were found to be 5.24 g NH 3 -N/m 3 -h and 17.2 g H 2 S-S/m 3 -h at an empty bed gas residence time of 23.6 s. Negligible pressure drops (< 4 mm H 2 O) after continuous operation demonstrate the suitability of PU as a practical packing material in wet chemical scrubbers for NH 3 and H 2 S removals from high-volume dilute emissions.

Biological activation of carbon filters.

PubMed

Seredyńska-Sobecka, Bozena; Tomaszewska, Maria; Janus, Magdalena; Morawski, Antoni W

2006-01-01

To prepare biological activated carbon (BAC), raw surface water was circulated through granular activated carbon (GAC) beds. Biological activity of carbon filters was initiated after about 6 months of filter operation and was confirmed by two methods: measurement of the amount of biomass attached to the carbon and by the fluorescein diacetate (FDA) test. The effect of carbon pre-washing on WG-12 carbon properties was also studied. For this purpose, the nitrogen adsorption isotherms at 77K and Fourier transform-infrared (FT-IR) spectra analyses were performed. Moreover, iodine number, decolorizing power and adsorption properties of carbon in relation to phenol were studied. Analysis of the results revealed that after WG-12 carbon pre-washing its BET surface increased a little, the pH value of the carbon water extract decreased from 11.0 to 9.4, decolorizing power remained at the same level, and the iodine number and phenol adsorption rate increased. In preliminary studies of the ozonation-biofiltration process, a model phenol solution with concentration of approximately 10mg/l was applied. During the ozonation process a dose of 1.64 mg O(3)/mg TOC (total organic carbon) was employed and the contact time was 5 min. Four empty bed contact times (EBCTs) in the range of 2.4-24.0 min were used in the biofiltration experiment. The effectiveness of purification was measured by the following parameters: chemical oxygen demand (COD(Mn)), TOC, phenol concentration and UV(254)-absorbance. The parameters were found to decrease with EBCT.

Differential Diagnosis and Treatment of Impaired Bladder Emptying

PubMed Central

Yoshimura, Naoki; Chancellor, Michael B

2004-01-01

Although much attention is paid to urinary incontinence, the condition of incomplete bladder emptying is becoming more common with the aging of the US population and the widespread use of anticholinergic drugs to treat overactive bladder. This disorder can often be silent until end-stage presentation of overflow incontinence. In this article, we review the pathophysiologic conditions of the bladder and urethra that can cause impaired bladder emptying and discuss how to evaluate and screen the patient with a bladder that does not empty. In addition, we provide an overview of treatment options available for impaired bladder emptying and consider the research that is under way to find the best therapies for the failing bladder. PMID:16985851

Treatment of Perchlorate-Contaminated Groundwater Using Highly-Selective, Regenerable Anion-Exchange Resins at Edwards Air Force Base

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gu, B.

2003-05-30

Selective ion exchange is one of the most effective treatment technologies for removing low levels of perchlorate (ClO{sub 4}{sup -}) from contaminated water because of its high efficiency without adverse impacts on the water quality caused by adding or removing any chemicals or nutrients. This report summarizes both the laboratory and a field pilot-scale studies to determine the ability and efficiency of the bifunctional synthetic resins to remove ClO{sub 4}{sup -} from the contaminated groundwater at the Edwards Air Force Base in California. Regeneration of the resins after groundwater treatment was also evaluated using the FeCl{sub 3}-HCl regeneration technique recentlymore » developed at Oak Ridge National Laboratory. On the basis of this study, the bifunctional resin, D-3696 was found to be highly selective toward ClO{sub 4}{sup -} and performed much better than one of the best commercial nitrate-selective resins (Purolite A-520E) and more than an order of magnitude better than the Purolite A-500 resin (with a relatively low selectivity). At an influent concentration of {approx} 450 {micro}g/L ClO{sub 4}{sup -} in groundwater, the bifunctional resin bed treated {approx} 40,000 empty bed volumes of groundwater before a significant breakthrough of ClO{sub 4}{sup -} occurred. The presence of relatively high concentrations of chloride and sulfate in site groundwater did not appear to affect the ability of the bifunctional resin to remove ClO{sub 4}{sup -}. However, the presence of high iron or iron oxyhydroxides and/or biomass in groundwater caused a significant fouling of the resin beds and greatly influenced the effectiveness in regenerating the resins sorbed with ClO{sub 4}{sup -}. Under such circumstances, a prefilter ({approx} 0.5-1 {micro}m) was found to be necessary to remove these particulates and to reduce the risk of fouling of the resin beds. Without significant fouling, the resin bed could be effectively regenerated by the FeCl{sub 3} displacement technique. Nearly 100% of the sorbed ClO{sub 4}{sup -} was displaced or recovered after elution with only {approx} 2-5 bed volumes of the FeCl{sub 3}-HCl regenerant solution. On the basis of both the laboratory and field pilot-scale studies, they therefore anticipate that a combination of the selective ion exchange and the FeCl{sub 3}-regeneration technologies may offer a cost-effective means to remove ClO{sub 4}{sup -} from contaminated groundwater with significantly reduced waste generation and operational cost.« less

Increase of transient lower esophageal sphincter relaxation associated with cascade stomach

PubMed Central

Kawada, Akiyo; Kusano, Motoyasu; Hosaka, Hiroko; Kuribayashi, Shiko; Shimoyama, Yasuyuki; Kawamura, Osamu; Akiyama, Junichi; Yamada, Masanobu; Akuzawa, Masako

2017-01-01

We previously reported that cascade stomach was associated with reflux symptoms and esophagitis. Delayed gastric emptying has been believed to initiate transient lower esophageal sphincter relaxation (TLESR). We hypothesized that cascade stomach may be associated with frequent TLESR with delayed gastric emptying. Eleven subjects with cascade stomach and 11 subjects without cascade stomach were enrolled. Postprandial gastroesophageal manometry and gastric emptying using a continuous 13C breath system were measured simultaneously after a liquid test meal. TLESR events were counted in early period (0–60 min), late period (60–120 min), and total monitoring period. Three parameters of gastric emptying were calculated: the half emptying time, lag time, and gastric emptying coefficient. The median frequency of TLESR events in the cascade stomach and non-cascade stomach groups was 6.0 (median), 4.6 (interquartile range) vs 5.0, 3.0 in the early period, 5.0, 3.2 vs 3.0, 1.8 in the late period, and 10.0, 6.2 vs 8.0, 5.0 in the total monitoring period. TLESR events were significantly more frequent in the cascade stomach group during the late and total monitoring periods. In contrast, gastric emptying parameters showed no significant differences between the two groups. We concluded that TLESR events were significantly more frequent in persons with cascade stomach without delayed gastric emptying. PMID:28584403

Disturbed gastric emptying in the short bowel syndrome. Evidence for a 'colonic brake'.

PubMed Central

Nightingale, J M; Kamm, M A; van der Sijp, J R; Morris, G P; Walker, E R; Mather, S J; Britton, K E; Lennard-Jones, J E

1993-01-01

Gastric emptying of liquid (orange juice containing technetium-99m (99mTc) labelled antimony sulphide colloid) and solid (570 kcal pancake containing 0.5 mm resin microspheres labelled with Indium-111 (111-In)) was measured in seven patients with jejunum and no colon (jejunal lengths 30-160 cm), six patients with jejunum in continuity with the colon (jejunal length 25-75 cm), and in 12 normal subjects. In patients with no colon early emptying of liquid was rapid (median 25% emptying: 7 v 25 min, no colon v normal, p < 0.05); early gastric emptying of solid was rapid in two (each with less than 100 cm jejunum) and normal in the other five. Gastric emptying of liquid and solid for patients with jejunum in continuity with the colon was normal for the first three hours. There was increased liquid and solid retained in the stomach at six hours in both groups of patients (p < 0.01). Small bowel transit time was faster than in normal subjects for liquid in both groups of patients (p < 0.05) and for solid in those with no colon (p < 0.05). Rapid gastric emptying of liquid may contribute to the large stomal output in patients with a high jejunostomy. Preservation of the colon after a major small intestinal resection exerts a braking effect on the rate of early gastric emptying of liquid. PMID:8406148

Performance of Eleocharis macrostachya and its importance for arsenic retention in constructed wetlands.

PubMed

Olmos-Márquez, Mario Alberto; Alarcón-Herrera, Maria Teresa; Martín-Domínguez, Ignacio Ramiro

2012-03-01

Arsenic (As) can be removed from water via rhizofiltration using phytostabilizing plants. The aim of this study was to investigate the performance of Eleocharis macrostachya in constructed wetland prototypes, as well as the plant's arsenic mass retention and the distribution of As along the wetland flow gradient and the soil in the wetland mesocosmos. Experiments were carried out in laboratory-scale wetland prototypes, two planted with E. macrostachya and one without plants. Samples of water were taken at the inlet and outlet of the wetlands during the 33-week test period. At the end of the experiment, plants and soil (silty-sand) from each prototype were divided in three equal segments (entrance, middle and exit) and analyzed for their arsenic content. Results revealed that the planted wetlands have a higher As-mass retention capacity (87-90% of the total As inflow) than prototypes without plants (27%). As mass balance in the planted wetlands revealed that 78% of the total inflowing As was retained in the soil bed. Nearly 2% was absorbed in the plant roots, 11% was flushed as outflow, and the fate of the remaining 9% is unknown. In the prototype without plants, the soil retained 16% of As mass, 72% of the arsenic was accounted for in the outflow, and 12% was considered unknown. Although E. macrostachya retained only 2% of the total arsenic mass in their roots, its presence was a determining factor for arsenic retention in the wetland soil medium. Hence, planted wetlands might be a suitable option for treating As-contaminated water.

New element for optimizing the functioning of sediment traps

NASA Astrophysics Data System (ADS)

Schwindt, Sebastian; Franca, Mário; Schleiss, Anton

2017-04-01

Sediment traps protect urban areas against excessive sediment transport during hazardous floods and consist typically of a retention basin with an open sediment check dam at the downstream end. The design, as well as the morphological processes within the retention basin, were analyzed by several authors. With regard to open sediment check dams two types of triggering mechanisms for the initiation of sediment retention can be distinguished: (1) mechanical and (2) hydraulic clogging of the structure. Recent studies have shown that outlet structures combining both clogging principles may be considered to avoid undesired self-flushing. Further elements of check dams are conceivable, e.g. for retaining or conveying driftwood. This study analyses experimentally working principles and design criteria of standard elements of sediment traps. Furthermore, it introduces a new structural element to the sediment trap design with a guiding channel in the retention reservoir. Taking into account the natural shape of mountain rivers, the guiding channel has a trapezoidal cross-section shape and a rough but fixed bed. The effect of the guiding channel on sediment deposition pattern and re-mobilization are studied by means of physical model experiments with a standardized hydrograph and variable sediment supply. The results are evaluated by means of zenithal pictures and bedload transport rate, measured at the downstream end of the model. Major advantages of the combined use of both clogging principles include an improved control of the initiation of sediment deposition in order to allow for sediment transfer for small floods and a reduction of hazards related to self-flushing.

Modeling the effects of surfactant, hardness, and natural organic matter on deposition and mobility of silver nanoparticles in saturated porous media.

PubMed

Park, Chang Min; Heo, Jiyong; Her, Namguk; Chu, Kyoung Hoon; Jang, Min; Yoon, Yeomin

2016-10-15

This study aims to provide insights into the mechanisms governing the deposition and retention of silver nanoparticles (AgNPs) in saturated porous media. Column experiments were conducted with quartz sand under saturated conditions to investigate the deposition kinetics of AgNPs, their mobility at different groundwater hardnesses (10-400 mg/L as CaCO3), and humic acid (HA, 0-50 mg/L as dissolved organic carbon [DOC]). An anionic surfactant, sodium dodecyl sulfate (SDS), was used as a dispersing agent to prepare a SDS-AgNPs suspension. The deposition kinetics of AgNPs were highly sensitive to the surfactant concentration, ionic strength, and cation type in solution. The breakthrough curves (BTCs) of SDS-AgNPs suggested that the transport and retention were influenced by groundwater hardness and HA. At low water hardness and high HA, high mobility of SDS-AgNPs was observed in saturated conditions. However, the retention of SDS-AgNPs increased substantially in very hard water with a low concentration of HA, because of a decreased primary energy barrier and the straining effect during the course of transport experiments. A modified clean-bed filtration theory and a two-site kinetic attachment model showed good fits with the BTCs of SDS-AgNPs. The fitted model parameters (katt and kstr) could be used successfully to describe that the retention behaviors were dominated by electrostatic and electrosteric repulsion, based on extended Derjaguin-Landau-Vaerwey-Overbeek calculations. Copyright © 2016 Elsevier Ltd. All rights reserved.

Direct comparison of solid-phase gastric emptying times assessed by means of a carbon isotope-labeled sodium acetate breath test and technetium Tc 99m albumin colloid radioscintigraphy in healthy cats.

PubMed

Schmitz, Silke; Götte, Birte; Borsch, Christian; Kunz, Clemens; Failing, Klaus; Neiger, Reto

2014-07-01

To directly compare solid-phase gastric emptying times assessed by means of a [(13)C]sodium acetate breath test ([(13)C]-SABT) and technetium Tc 99m albumin colloid radioscintigraphy ((99m)Tc-ACR) in healthy cats. 12 healthy cats. After ingestion of a test meal containing 50 mg of [(13)C]sodium acetate and 250 MBq of (99m)Tc-albumin colloid, each cat underwent simultaneous [(13)C]-SABT and (99m)Tc-ACR on 2 consecutive days. Breath samples and scintigrams were acquired at 30, 60, 90, 120, 150, 180, 210, 240, 300, 360, 480, and 600 minutes after meal ingestion. Quartiles of gastric emptying (25%, 50%, and 75%) were calculated for breath test analysis by use of the area under the curve of the (13)C:(12)C ratio. Quartiles of gastric emptying times were extrapolated from the scintigraphic findings by beans of nonlinear curve regression analysis. Mean ± SD gastric half-emptying (50%) times obtained with [(13)C]-SABT and (99m)Tc-ACR, were 239 ± 28 minutes and 276 ± 59 minutes, respectively. A 2-way repeated-measures ANOVA revealed that mean gastric emptying times determined with [(13)C]-SABT and (99m)Tc-ACR differed significantly. For the stages of gastric emptying, Pearson correlation between the 2 methods was good at 25% (r = 0.655) and weak at 50% (r = 0.588) and 75% (r = 0.566)of gastric emptying. Results indicated that the [(13)C]-SABT can be a valid alternative to (99m)Tc-ACR in healthy cats; it was easy to perform, was tolerated well by the cats, and had acceptable correlation to scintigraphic findings at gastric emptying of 25%, 50% and 75%. Studies in cats with delayed gastric emptying will be needed to verify the validity of the [(13)C]-SABT.

Risk factors associated with delayed gastric emptying after subtotal gastrectomy with Billroth-I anastomosis using circular stapler for early gastric cancer patients

PubMed Central

Kim, Ki Han; Jung, Ghap Joong

2012-01-01

Purpose Gastric surgery may potentiate delayed gastric emptying. Billroth I gastroduodenostomy using a circular stapler is the most preferable reconstruction method. The purpose of this study is to analyze the risk factors associated with delayed gastric emptying after radical subtotal gastrectomy with Billroth I anastomosis using a stapler for early gastric cancer. Methods Three hundred and seventy-eight patients who underwent circular stapled Billroth I gastroduodenostomy after subtotal gastrectomy due to early gastric cancer were analyzed retrospectively. One hundred and eighty-two patients had Billroth I anastomosis using a 25 mm diameter circular stapler, and 196 patients had anastomosis with a 28 or 29 mm diameter circular stapler. Clinicopathological features and postoperative outcomes were evaluated and compared between the two groups. Delayed gastric emptying was diagnosed by symptoms and simple abdomen X-ray with or without upper gastrointestinal series or endoscopy. Results Postoperative delayed gastric emptying was found in 12 (3.2%) of the 378 patients. Among all the variables, distal margin and circular stapler diameter were significantly different between the cases with delayed gastric emptying and no delayed gastric emptying. There were statistically significant differences in sex, body mass index, comorbidity, complication, and operation type according to circular stapler diameter. In both univariate and multivariate logistic regression analyses, only the stapler diameter was found to be a significant factor affecting delayed gastric emptying (P = 0.040). Conclusion In this study, the circular stapler diameter was one of the most significant predictable factors of delayed gastric emptying for Billroth I gastroduodenostomy. The use of a 28 or 29 mm diameter circular stapler rather than a 25 mm diameter stapler in stapled gastroduodenostomy for early gastric cancer can reduce postoperative delayed gastric emptying associated with anastomosic stenosis or edema with relative safety. PMID:23166886

[Effect of erythromycin on electrical activity and gastric emptying of the intrathoracic stomach after esophagectomy for esophageal cancer].

PubMed

Liu, Jun-feng; Liu, Cheng-jun; Shi, Zhi-hua; Liu, Xin-bo; Jiang, Tao; Wang, Fu-shun; Cao, Fu-min; Li, Bao-qing

2013-09-01

To investigate the effect of erythromycin on electrical activity and emptying of the intrathoracic stomach after esophagectomy for esophageal cancer. Thirty patients undergoing esophagectomy for cancer and esophagogastrostomy above the aortic arch were divided into the study group (n=15) and the control group (n=15). Electrogastrography and radionuclide gastric emptying were examined for these patients before and 1, 3, 6, 12 months after surgery. Patients in the study group received erythromycin (0.25 g tid po) for 1 week before examination. The wave amplitude (Uv), dominant frequency (CPM) and percentage of normal slow wave (%) of electrogastrogram decreased after surgery and returned to normal at the first postoperative month in the study group and the 12th postoperative month in the control group (P>0.05). Gastric emptying was significantly delayed after esophagectomy, and returned to normal one year after operation in the study group (P>0.05). However, gastric emptying remained abnormal in the control group (P<0.01). Erythromycin improves electrical activity and emptying of the stomach after esophagectomy for cancer. Gastric emptying recovery later than the recovery of electrical activity, which may be related to gastric ischemia and edema.

Modelling of percolation rate of stormwater from underground infiltration systems.

PubMed

Burszta-Adamiak, Ewa; Lomotowski, Janusz

2013-01-01

Underground or surface stormwater storage tank systems that enable the infiltration of water into the ground are basic elements used in Sustainable Urban Drainage Systems (SUDS). So far, the design methods for such facilities have not taken into account the phenomenon of ground clogging during stormwater infiltration. Top layer sealing of the filter bed influences the infiltration rate of water into the ground. This study presents an original mathematical model describing changes in the infiltration rate variability in the phases of filling and emptying the storage and infiltration tank systems, which enables the determination of the degree of top ground layer clogging. The input data for modelling were obtained from studies conducted on experimental sites on objects constructed on a semi-technological scale. The experiment conducted has proven that the application of the model developed for the phase of water infiltration enables us to estimate the degree of module clogging. However, this method is more suitable for reservoirs embedded in more permeable soils than for those located in cohesive soils.

Microbial Community in a Biofilter for Removal of Low Load Nitrobenzene Waste Gas

PubMed Central

Zhai, Jian; Wang, Zhu; Shi, Peng; Long, Chao

2017-01-01

To improve biofilter performance, the microbial community of a biofilter must be clearly defined. In this study, the performance of a lab-scale polyurethane biofilter for treating waste gas with low loads of nitrobenzene (NB) (< 20 g m-3 h-1) was investigated when using different empty bed residence times (EBRT) (64, 55.4 and 34 s, respectively). In addition, the variations of the bacterial community in the biofilm on the longitudinal distribution of the biofilters were analysed by using Illumina MiSeq high-throughput sequencing. The results showed that NB waste gas was successfully degraded in the biofilter. High-throughput sequencing data suggested that the phylum Actinobacteria and genus Rhodococcus played important roles in the degradation of NB. The variations of the microbial community were attributed to the different intermediate degradation products of NB in each layer. The strains identified in this study were potential candidates for purifying waste gas effluents containing NB. PMID:28114416

Potential application of an Aspergillus strain in a pilot biofilter for benzene biodegradation

PubMed Central

Sun, Da; Zhang, Kun; Duan, Chuanren; Wu, Wei; Deng, Daiyong; Yu, Donghong; Shahzad, M. Babar; Xu, Dake; Tang, Ju; Luo, Li; Chen, Jia; Wang, Jinxuan; Chen, Yidan; Xie, Xiang; Wang, Guixue

2017-01-01

A biofilter with fungus was developed for efficient degradation of benzene, which can overcome the potential risk of leakage commonly found in such services. Results indicated that the optimum parameter values were temperature 40 °C, pH 6, and 500 mg L−1 of the initial benzene concentration. Besides, the empty bed residence time and inlet load range of biofilter were set to 20 s and 21.23–169.84 g m−3 h−1 respectively. Under these conditions, this biofilter can obtain the maximum removal efficiency of more than 90%, the eliminating capacity could be up to 151.67 g m−3 h−1. Furthermore, scanning electron microscopy was used to investigate three filler materials for packing fungus biofilm. This is the first study introducing an Aspergillus strain for benzene removal and these results highlight that the development of this biofilter has the potential scaling-up application as gas-processing of industrial wastes. PMID:28383064

Transient Characterization of Type B Particles in a Transport Riser

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shadle, L.J.; Monazam, E.R.; Mei, J.S.

2007-01-01

Simple and rapid dynamic tests were used to evaluate fluid dynamic behavior of granular materials in the transport regime. Particles with densities ranging from 189 to 2,500 kg/m3 and Sauter mean size from 61 to 812 μm were tested in a 0.305 m diameter, 15.5 m height circulating fluidized bed (CFB) riser. The transient tests involved the abrupt stoppage of solids flow for each granular material over a wide range gas flow rates. The riser emptying time was linearly related to the Froude number in each of three different operating regimes. The flow structure along the height of the risermore » followed a distinct pattern as tracked through incremental pressures. These results are discussed to better understand the transformations that take place when operating over various regimes. During the transients the particle size distribution was measured. The effects of pressure, particle size, and density on test performance are also presented.« less

Potential application of an Aspergillus strain in a pilot biofilter for benzene biodegradation

NASA Astrophysics Data System (ADS)

Sun, Da; Zhang, Kun; Duan, Chuanren; Wu, Wei; Deng, Daiyong; Yu, Donghong; Shahzad, M. Babar; Xu, Dake; Tang, Ju; Luo, Li; Chen, Jia; Wang, Jinxuan; Chen, Yidan; Xie, Xiang; Wang, Guixue

2017-04-01

A biofilter with fungus was developed for efficient degradation of benzene, which can overcome the potential risk of leakage commonly found in such services. Results indicated that the optimum parameter values were temperature 40 °C, pH 6, and 500 mg L-1 of the initial benzene concentration. Besides, the empty bed residence time and inlet load range of biofilter were set to 20 s and 21.23-169.84 g m-3 h-1 respectively. Under these conditions, this biofilter can obtain the maximum removal efficiency of more than 90%, the eliminating capacity could be up to 151.67 g m-3 h-1. Furthermore, scanning electron microscopy was used to investigate three filler materials for packing fungus biofilm. This is the first study introducing an Aspergillus strain for benzene removal and these results highlight that the development of this biofilter has the potential scaling-up application as gas-processing of industrial wastes.

Effect of temperature on pyrolysis product of empty fruit bunches

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rahman, Aizuddin Abdul; Sulaiman, Fauziah; Abdullah, Nurhayati

2015-04-24

Pyrolysis of empty fruit bunches (EFB) was performed in a fixed bed reactor equipped with liquid collecting system. Pyrolysis process was conducted by varying the terminal pyrolysis temperature from 300 to 500°C under heating rate of 10°C/min for at least 2 hours. Char yield was obtained highest at 300°C around 55.88 wt%, and started to decrease as temperature increase. The maximum yield of pyrolysis liquid was obtained around 54.75 wt% as pyrolysis temperature reach 450°C. For gas yield percentage, the yield gained as temperature was increased from 300 to 500°C, within the range between 8.44 to 19.32 wt%. The charmore » obtained at 400°C has great potential as an alternative solid fuel, due to its high heating value of 23.37 MJ/kg, low in volatile matter and ash content which are approximately around 40.32 and 11.12 wt%, respectively. The collected pyrolysis liquid within this temperature range found to have high water content of around 16.15 to 18.20 wt%. The high aqueous fraction seemed to cause the pyrolysis liquid to have low HHV which only ranging from 10.81 to 12.94 MJ/kg. These trends of results showed that necessary enhancement should be employ either on the raw biomass or pyrolysis products in order to approach at least the minimum quality of common hydrocarbon solid or liquid fuel. For energy production, both produced bio-char and pyrolysis liquid are considered as sustainable sources of bio-energy since they contained low amounts of nitrogen and sulphur, which are considered as environmental friendly solid and liquid fuel.« less

Specific esophagogram to assess functional outcomes after Heller's myotomy and Dor's fundoplication for esophageal achalasia.

PubMed

Tsoukali, E; Gouvas, N; Tsiaoussis, J; Pechlivanides, G; Zervakis, N; Mantides, A; Xynos, E

2011-09-01

Esophageal emptying assessed at the 'timed barium' esophagogram correlates well with symptomatic outcomes after pneumatic dilation for esophageal achalasia, although 30% of patients with satisfactory outcome exhibit partial improvement in emptying. The aim of the study was to investigate any correlation of esophageal emptying to symptomatic response after laparoscopic Heller's myotomy and Dor's fundoplication. 'Bread and barium' (transit time of a barium opaque bread bolus) and 'timed barium' (height of esophageal barium column 5 minutes after ingestion of 200-250 mL of barium suspension) esophagogram was used to assess esophageal emptying in 73 patients with esophageal achalasia before 1 and 5 years (31 cases) after laparoscopic myotomy and anterior fundoplication. Symptoms assessment was based to a specific score. At 1-year follow-up, excellent and good symptomatic results were obtained in 95% of the cases. Esophageal maximum diameter, esophageal transit time, and esophageal barium column were significantly correlated to each other and to symptom score postoperatively (P < 0.001). Complete and partial (<90% and 50-90% postoperative reduction in barium column, respectively) emptying was seen in 55% and 31% of patients with excellent result. Patients with a pseudodiverticulum postoperatively had a more delayed esophageal emptying than those without. Symptomatic outcome and esophageal emptying did not deteriorate at 5-year follow-up. Esophageal emptying assessed by 'barium and bread' and 'timed barium' esophagogram correlated well with symptomatic outcome after laparoscopic myotomy for esophageal achalasia. Complete symptomatic relief does not necessarily reflect complete esophageal emptying. Outcomes do not deteriorate by time. Because of wide availability, esophagogram can be applied in follow-up of postmyotomy patients in conjunction with symptomatic evaluation. © 2011 Copyright the Authors. Journal compilation © 2011, Wiley Periodicals, Inc. and the International Society for Diseases of the Esophagus.

Effects of rehabilitation management on gastric emptying function in older adults with diabetes.

PubMed

Shao, Z M; Yao, J F; Chen, J; Yu, Z W; Yu, X F; Zheng, J J; Tang, X

2014-01-24

The relationship between gastric emptying dysfunction and blood glucose concentration in elderly with type 2 diabetes mellitus was investigated, and the effect of rehabilitation exercise prescription training on gastric emptying in the geriatric diabetic patients was evaluated. A total of 160 older type 2 diabetic adults and 30 cases of non-diabetic patients were studied with regard to the gastric half emptying time (GET1/2) of solid meals radiolabelled with 99mTc. Eighty delayed gastric emptying diabetic patients were randomly divided into 4 four groups: rehabilitation exercise + mosapride group (N = 20), rehabilitation exercise group (N = 20), mosapride group (N = 20), and control group (N = 20). The level of blood glucose was measured every six months in a two-year follow-up. The solid GET1/2 of regulated blood glycemic control patients showed no statistically significant differences from non-diabetic patients (P > 0.05). However, the value for poor blood glycemic control patients exhibited significant statistical differences compared with both non-diabetic (P < 0.01) and regulated blood glycemic control group patients (P < 0.01). It showed that the gastric emptying time improved in the rehabilitation exercise group, mosapride group and rehabilitation exercise group + mosapride group after two years of treatment (P < 0.05). Fasting blood glucose in both rehabilitation exercise group and rehabilitation exercise + mosapride group was significantly decreased. Postprandial blood glucose in the rehabilitation exercise group, mosapride group, rehabilitation exercise group + mosapride group was significantly decreased. High blood glucose level can delay gastric emptying in older type 2 diabetic patients. Gastric emptying and blood glucose control affect each other. It was shown that appropriate rehabilitation exercise combined with prokinetic agent may improve gastric emptying in some geriatric type 2 diabetic patients and help control their blood glucose.

Gastric emptying, postprandial blood pressure, glycaemia and splanchnic flow in Parkinson's disease.

PubMed

Trahair, Laurence G; Kimber, Thomas E; Flabouris, Katerina; Horowitz, Michael; Jones, Karen L

2016-05-28

To determine gastric emptying, blood pressure, mesenteric artery blood flow, and blood glucose responses to oral glucose in Parkinson's disease. Twenty-one subjects (13 M, 8 F; age 64.2 ± 1.6 years) with mild to moderate Parkinson's disease (Hoehn and Yahr score 1.4 ± 0.1, duration of known disease 6.3 ± 0.9 years) consumed a 75 g glucose drink, labelled with 20 MBq (99m)Tc-calcium phytate. Gastric emptying was quantified with scintigraphy, blood pressure and heart rate with an automated device, superior mesenteric artery blood flow by Doppler ultrasonography and blood glucose by glucometer for 180 min. Autonomic nerve function was evaluated with cardiovascular reflex tests and upper gastrointestinal symptoms by questionnaire. The mean gastric half-emptying time was 106 ± 9.1 min, gastric emptying was abnormally delayed in 3 subjects (14%). Systolic and diastolic blood pressure fell (P < 0.001) and mesenteric blood flow and blood glucose (P < 0.001 for both) increased, following the drink. Three subjects (14%) had definite autonomic neuropathy and 8 (38%) had postprandial hypotension. There were no significant relationships between changes in blood pressure, heart rate or mesenteric artery blood flow with gastric emptying. Gastric emptying was related to the score for autonomic nerve function (R = 0.55, P < 0.01). There was an inverse relationship between the blood glucose at t = 30 min (R = -0.52, P < 0.05), while the blood glucose at t = 180 min was related directly (R = 0.49, P < 0.05), with gastric emptying. In mild to moderate Parkinson's disease, gastric emptying is related to autonomic dysfunction and a determinant of the glycaemic response to oral glucose.

Mosapride Accelerates the Delayed Gastric Emptying of High-Viscosity Liquids: A Crossover Study Using Continuous Real-Time 13C Breath Test (BreathID System)

PubMed Central

Sakamoto, Yasunari; Sekino, Yusuke; Yamada, Eiji; Ohkubo, Hidenori; Higurashi, Takuma; Sakai, Eiji; Iida, Hiroshi; Hosono, Kunihiro; Endo, Hiroki; Nonaka, Takashi; Ikeda, Tamon; Fujita, Koji; Yoneda, Masato; Koide, Tomoko; Takahashi, Hirokazu; Goto, Ayumu; Abe, Yasunobu; Gotoh, Eiji; Maeda, Shin; Nakajima, Atsushi

2011-01-01

Background/Aims The administration of liquid nutrients to patients is often accompanied by complications such as gastroesophageal reflux. To prevent gastroesophageal reflux, high-viscosity liquid meals are used widely, however, it still remains controversial whether high-viscosity liquid meals have any effect on the rate of gastric emptying. The present study was conducted with the aim of determining whether high-viscosity liquid meals had any effect on the rate of gastric emptying and mosapride might accelerate the rate of gastric emptying of high-viscosity liquid meals. Methods Six healthy male volunteers underwent 3 tests at intervals of > 1 week. After fasting for > 8 hours, each subject received one of three test meals (liquid meal only, high-viscosity liquid meal [liquid meal plus pectin] only, or high-viscosity liquid meal 30 minutes after intake of mosapride). A 13C-acetic acid breath test was performed, which monitored the rate of gastric emptying for 4 hours. Using the Oridion Research Software (β version), breath test parameters were calculated. The study parameters were examined for all the 3 test conditions and compared using the Freidman test. Results Gastric emptying was significantly delayed following intake of a high-viscosity liquid meal alone as compared with a liquid meal alone; however, intake of mosapride prior to a high-viscosity liquid meal was associated with a significantly accelerated rate of gastric emptying as compared with a high-viscosity liquid meal alone. Conclusions This study showed that high-viscosity liquid meals delayed gastric emptying: however, mosapride recovered the delayed rate of gastric emptying by high-viscosity liquid meals. PMID:22148109

[*C]octanoic acid breath test to measure gastric emptying rate of solids.

PubMed

Maes, B D; Ghoos, Y F; Rutgeerts, P J; Hiele, M I; Geypens, B; Vantrappen, G

1994-12-01

We have developed a breath test to measure solid gastric emptying using a standardized scrambled egg test meal (250 kcal) labeled with [14C]octanoic acid or [13C]octanoic acid. In vitro incubation studies showed that octanoic acid is a reliable marker of the solid phase. The breath test was validated in 36 subjects by simultaneous radioscintigraphic and breath test measurements. Nine healthy volunteers were studied after intravenous administration of 200 mg erythromycin and peroral administration of 30 mg propantheline, respectively. Erythromycin significantly enhanced gastric emptying, while propantheline significantly reduced gastric emptying rates. We conclude that the [*C]octanoic breath test is a promising and reliable test for measuring the gastric emptying rate of solids.

Delayed Gastric Emptying after Living Donor Hepatectomy for Liver Transplantation

PubMed Central

Griesemer, Adam D.; Parsons, Ronald F.; Graham, Jay A.; Emond, Jean C.; Samstein, Benjamin

2014-01-01

Delayed gastric emptying is a significant postoperative complication of living donor hepatectomy for liver transplantation and may require endoscopic or surgical intervention in severe cases. Although the mechanism of posthepatectomy delayed gastric emptying remains unknown, vagal nerve injury during intraoperative dissection and adhesion formation postoperatively between the stomach and cut liver surface are possible explanations. Here, we present the first reported case of delayed gastric emptying following fully laparoscopic hepatectomy for living donor liver transplantation. Additionally, we also present a case in which symptoms developed after open right hepatectomy, but for which dissection for left hepatectomy was first performed. Through our experience and these two specific cases, we favor a neurovascular etiology for delayed gastric emptying after hepatectomy. PMID:25610698

Simulation of empty container logistic management at depot

NASA Astrophysics Data System (ADS)

Sze, San-Nah; Sek, Siaw-Ying Doreen; Chiew, Kang-Leng; Tiong, Wei-King

2017-07-01

This study focuses on the empty container management problem in a deficit regional area. Deficit area is the area having more export activities than the import activities, which always have a shortage of empty container. This environment has challenged the trading companies in the decision making in distributing the empty containers. A simulation model that fit to the environment is developed. Besides, a simple heuristic algorithm with some hard and soft constraints consideration are proposed to plan the logistic of empty container supply. Then, the feasible route with the minimum cost will be determined by applying the proposed heuristic algorithm. The heuristic algorithm can be divided into three main phases which are data sorting, data assigning and time window updating.

Effects of Swertia japonica extract and its main compound swertiamarin on gastric emptying and gastrointestinal motility in mice.

PubMed

Kimura, Yoshiyuki; Sumiyoshi, Maho

2011-09-01

The Swertia japonica is used clinically as a remedy for gastrointestinal symptoms in Japan. We examined the effects of a S. japonica and swertiamarin on gastric emptying and gastrointestinal motility in atropine-, dopamine-, and 5-hydroxytryptamine (5-HT)-treated mice. All three preparations inhibited reductions in gastric emptying and gastrointestinal motility induced by dopamine (1mg/kg, intraperitoneal injection, ip). Neither the powder, swertiamarin, nor itopride had any effect on the reductions in gastric emptying and gastrointestinal motility caused by 5-HT (4 mg/kg, ip). These findings suggest that the powder and swertiamarin stimulate gastric emptying and gastrointestinal motility by inhibiting the dopamine D(2) receptor. Copyright © 2011 Elsevier B.V. All rights reserved.

Reach Out and Eat: Food and Beverages Depicted in Books for Preschoolers.

PubMed

England, Jessica L; Linchey, Jennifer; Madsen, Kristine A; Patel, Anisha I

2015-11-01

To examine food and beverage depictions in books for preschoolers. Books for preschoolers from Reach Out and Read (ROR; n = 42), public library (n = 27), and Publisher's Weekly booklists (n = 31) were examined for nutritive and empty-calorie food and beverage depictions. It was found that 66% of books depicted at least 1 food or beverage. More books depicted nutritive items than empty-calorie items (87.5% vs 54.7%, P < .001). There was a trend toward fewer empty-calorie depictions in ROR books than in other booklists. Yet nearly half of ROR books depicted at least 1 empty-calorie item. ROR books also accounted for 5 of 10 books with the most empty-calorie item depictions and 3 of 4 books with branding. With regard to messaging, approximately a third of books with the most empty-calorie depictions promoted unhealthy foods. When selecting books for ROR, it may be important to consider food and beverage depictions and messages. © The Author(s) 2015.

Reach Out and Eat: Food and Beverages Depicted in Books for Preschoolers

PubMed Central

England, Jessica L.; Linchey, Jennifer; Madsen, Kristine A.; Patel, Anisha I.

2015-01-01

Objective To examine food and beverage depictions in books for preschoolers. Methods Books for preschoolers from Reach Out and Read (ROR; n = 42), public library (n = 27), and Publisher's Weekly booklists (n = 31) were examined for nutritive and empty-calorie food and beverage depictions. Results It was found that 66% of books depicted at least I food or beverage. More books depicted nutritive items than empty-calorie items (87.5% vs 54.7%, P < .001). There was a trend toward fewer empty-calorie depictions in ROR books than in other booklists. Yet nearly half of ROR books depicted at least I empty-calorie item. ROR books also accounted for 5 of 10 books with the most empty-calorie item depictions and 3 of 4 books with branding. With regard to messaging, approximately a third of books with the most empty-calorie depictions promoted unhealthy foods. Conclusions When selecting books for ROR, it may be important to consider food and beverage depictions and messages. PMID:25715825

Postpyloric regulation of gastric emptying in rhesus monkeys.

PubMed

McHugh, P R; Moran, T H; Wirth, J B

1982-09-01

Saline (0.9% NaCl) empties rapidly and exponentially from the stomach of the rhesus monkey, but glucose solutions empty at a calorie-constant rate of 0.4 kcal/min. By means of indwelling intragastric and intraduodenal cannulae we can demonstrate an inhibition on the delivery of saline from the stomach provoked by glucose placed beyond the pylorus. The inhibition varies directly with the glucose calories in the intestine and averages 2.5 min/kcal. That these two results (0.4 kcal/min and 2.5 min/kcal) are reciprocals suggests a feedback inhibition on the gastric emptying of nutrients arising from beyond the pylorus and adequate to explain the rate of glucose delivery to the intestine. A control theory description of gastric emptying that includes such feedback regulation can be derived from these data to explain the different gastric emptying patterns of nutrients and nonnutrient solutions. These patterns give this visceral system a precision in its management of nutrients that can provide information crucial to preabsorptive satiety.

Retention and mitigation of metals in sediment, soil, water, and plant of a newly constructed root-channel wetland (China) from slightly polluted source water.

PubMed

Wang, Baoling; Wang, Yu; Wang, Weidong

2014-01-01

Constructed root-channel wetland (CRCW) is a term for pre-pond/wetland/post-pond complexes, where the wetland includes plant-bed/ditch landscape and root-channel structure. Source water out of pre-ponds flows through alternate small ditches and plant beds with root-channels via a big ditch under hydraulic regulation. Then source water flows into post-ponds to finish final polishing. This article aims to explore the potential of components of a pilot CRCW in China on mitigating metals in micro-polluted source water during its initial operation stage. We investigated six heavy metals (Cd, Cr, Cu, Ni, Zn, and Pb) in surface sediment, plant-bed subsurface soil, water, and aquatic plants during 2012-2013. Monitoring results showed that pond/ditch sediments and plant-bed soil retained a significant amount of Cr, Ni, and Zn with 93.1%, 72.4%, and 57.5% samples showing contamination factor above limit 1 respectively. Remarkably the high values of metal enrichment factor (EF) occurred in root-channel zones. Water monitoring results indicated that Ni, Zn, and Pb were removed by 78.5% (66.7%), 57.6% (59.6%), and 26.0% (7.5%) in east (west) wetland respectively. Mass balance estimation revealed that heavy metal mass in the pond/ditch sediments accounted for 63.30% and that in plant-bed soil 36.67%, while plant uptake occupied only 0.03%. The heavy metal accretion flux in sediments was 0.41 - 211.08 μg · cm(-2) · a(-1), less than that in plant-bed soil (0.73 - 543.94 μg · cm(-2) · a(-1)). The 1.83 ha wetland has retained about 86.18 kg total heavy metals within 494 days after operation. This pilot case study proves that constructed root-channel wetland can reduce the potential ecological risk of purified raw water and provide a new and effective method for the removal of heavy metals from drinking water sources.

A super high-rate sulfidogenic system for saline sewage treatment.

PubMed

Tsui, To-Hung; Chen, Lin; Hao, Tianwei; Chen, Guang-Hao

2016-11-01

This study proposes a novel approach to resolve the challenging issue of sludge bed clogging in a granular sulfate-reducing upflow sludge bed (GSRUSB) reactor by means of introducing intermittent gas sparging to advance it into a super high-rate anaerobic bioreactor. Over a 196-day lab-scale trial, the GSRUSB system was operated from nominal hydraulic retention time of 4-hr to 40-min and achieved the highest organic loading rate of 13.31 kg COD/m 3 ·day which is substantially greater than the typical loading of 2.0-3.5 kg COD/m 3 ·day in a conventional upflow anaerobic sludge bed reactor treating dilute organic strength wastewater. The average organic removal efficiency and total dissolved sulfide of this system were 90 ± 4.2% and 158 ± 28 mg S/L, while organics residual in the effluent was 34 ± 14 mg COD/L. The control stage (without gas sparging) revealed that the sludge bed clogging happened concomitantly with the significant drop in extracellular polymeric substance content of granular sludge, through relevant chemical measurements and confocal laser scanning microscopy analyses. On the other hand, compared with increasing the effluent recirculation ratio (from 1.4 to 5), the three-dimensional computational fluid dynamics modeling in combination with energy dissipation analysis demonstrated that the gas sparging (at a superficial gas velocity of 0.8 m s -1 ) can create a 23 times higher liquid shear as well as enhanced particle attrition. Overall, this study not only developed a super high-rate anaerobic bioreactor for saline sewage treatment, but also shed light on the role of intermittent gas sparging in control of sludge bed clogging for anaerobic bioreactors. Copyright © 2016 Elsevier Ltd. All rights reserved.

Hydrologic characteristics and possible effects of surface mining in the northwestern part of West Branch Antelope Creek basin, Mercer County, North Dakota

USGS Publications Warehouse

Crawley, Mark E.; Emerson, Douglas G.

1981-01-01

Lignite beds and abundant discontinuous sandstone beds of the Paleocene Sentinel Butte Member of the Fort Union Formation and sand and gravel beds in the Quarternary glaciofluvial deposits (Antelope Creek aquifer) are the most important aquifers for domestic and livestock water supplies in the West Branch Antelope Creek basin. In the Beulah-Zap lignite, ground water moves from highland area in the west toward the Antelope Creek aquifer. Water levels in the basal Sentinel Butte sandstone appear to be controlled by the level of Lake Sakakawea. In the glaciofluvial deposits of the Antelope Creek aquifer water moves from a ground-water divide northwestward to Lake Sakakawea and southeastward toward the Knife River. Large water-level declines in wells completed in the lignite and shallower aquifers could be expected with mining. The effects probably would be limited to within 1 to 2 miles of an active mine. Surface-runoff duration could be altered by increased infiltration and retention in the reclaimed are and possible temporal extension of base flow could occur. Shallow ground water beneath mine sites would be expected to increase in dissolved solids and locally to contain large sodium and sulfate concentrations. In some locations movement of poor quality water toward the Antelope Creek aquifer would be expected. (USGS)

Application of an adsorptive-thermocatalytic process for BTX removal from polluted air flow

PubMed Central

2014-01-01

Background Zero valent iron and copper oxide nanoparticles (30-60 nm) were coated on a bed of natural zeolite (Clinoptilolite) with 1-2 mm grains and arranged as a dual filter in a stainless steel cylindrical reactor (I.D 4.5 cm and L = 30 cm) to investigating the coated bed removal efficiency for BTX. The experiments were conducted in three steps. First, with an air flow of 1.5 L/min and temperature range of 38 (ambient temperature) to 600°C the BTX removal and mineralization was surveyed. Then, in an optimized temperature the effect of flow rate and pollution loading rate were surveyed on BTX removal. Results The BTX removal at 300 and 400°C were respectively up to 87.47% and 94.03%. Also in these temperatures respectively 37.21% and 90.42% of BTX mineralization were achieved. In the retention times of 14.1 s and 7.05 s, respectively 96.18% and 78.42% of BTX was removed. Conclusions According to the results, this adsorptive-thermocatalytic process with using Clinoptilolite as an adsorbent bed and combined Fe0 and Cu2O nanoparticles as catalysts can be an efficient and competitive process in the condition of high flow rate and high pollution loading rate with an adequate process temperature of 350°C. PMID:24955244

Performance of a pilot-scale constructed wetland for stormwater runoff and domestic sewage treatment on the banks of a polluted urban river.

PubMed

Guo, Weijie; Li, Zhu; Cheng, Shuiping; Liang, Wei; He, Feng; Wu, Zhenbin

2014-01-01

To examine the performance of a constructed wetland system on stormwater runoff and domestic sewage (SRS) treatment in central east China, two parallel pilot-scale integrated constructed wetland (ICW) systems were operated for one year. Each ICW consisted of a down-flow bed, an up-flow bed and a horizontal subsurface flow bed. The average removal rates of chemical oxygen demand (CODCr), total suspended solids (TSS), ammonia (NH4(+)-N), total nitrogen (TN) and total phosphorus (TP) were 63.6, 91.9, 38.7, 43.0 and 70.0%, respectively, and the corresponding amounts of pollutant retention were approximately 368.3, 284.9, 23.2, 44.6 and 5.9 g m(-2) yr(-1), respectively. High hydraulic loading rate (HLR) of 200 mm/d and low water temperatures (<15 °C) resulted in significant decrease in removals for TP and NH4(+)-N, but had no significant effects on removals of COD and TSS. These results indicated that the operation of this ICW at higher HLR (200 mm/d) might be effective and feasible for TSS and COD removal, but for acceptable removal efficiencies of nitrogen and phosphorus it should be operated at lower HLR (100 mm/d). This kind of ICW could be employed as an effective technique for SRS treatment.

Assessment of gastric emptying in non-obese diabetic mice using a [13C]-octanoic acid breath test.

PubMed

Creedon, Christopher T; Verhulst, Pieter-Jan; Choi, Kyoung M; Mason, Jessica E; Linden, David R; Szurszewski, Joseph H; Gibbons, Simon J; Farrugia, Gianrico

2013-03-23

Gastric emptying studies in mice have been limited by the inability to follow gastric emptying changes in the same animal since the most commonly used techniques require killing of the animals and postmortem recovery of the meal(1,2). This approach prevents longitudinal studies to determine changes in gastric emptying with age and progression of disease. The commonly used [(13)C]-octanoic acid breath test for humans(3) has been modified for use in mice(4-6) and rats(7) and we previously showed that this test is reliable and responsive to changes in gastric emptying in response to drugs and during diabetic disease progression(8). In this video presentation the principle and practical implementation of this modified test is explained. As in the previous study, NOD LtJ mice are used, a model of type 1 diabetes(9). A proportion of these mice develop the symptoms of gastroparesis, a complication of diabetes characterized by delayed gastric emptying without mechanical obstruction of the stomach(10). This paper demonstrates how to train the mice for testing, how to prepare the test meal and obtain 4 hr gastric emptying data and how to analyze the obtained data. The carbon isotope analyzer used in the present study is suitable for the automatic sampling of the air samples from up to 12 mice at the same time. This technique allows the longitudinal follow-up of gastric emptying from larger groups of mice with diabetes or other long-standing diseases.

Pit Latrine Fecal Sludge Resistance Using a Dynamic Cone Penetrometer in Low Income Areas in Mzuzu City, Malawi

PubMed Central

Chirwa, Charles F. C.; Hall, Ralph P.; Krometis, Leigh-Anne H.; Vance, Eric A.; Edwards, Adam; Guan, Ting; Holm, Rochelle H.

2017-01-01

Pit latrines can provide improved household sanitation, but without effective and inexpensive emptying options, they are often abandoned once full and may pose a public health threat. Emptying techniques can be difficult, as the sludge contents of each pit latrine are different. The design of effective emptying techniques (e.g., pumps) is limited by a lack of data characterizing typical in situ latrine sludge resistance. This investigation aimed to better understand the community education and technical engineering needs necessary to improve pit latrine management. In low income areas within Mzuzu city, Malawi, 300 pit latrines from three distinct areas were assessed using a dynamic cone penetrometer to quantify fecal sludge strength, and household members were surveyed to determine their knowledge of desludging procedures and practices likely to impact fecal sludge characteristics. The results demonstrate that there is a significant difference in sludge strength between lined and unlined pits within a defined area, though sludge hardened with depth, regardless of the pit type or region. There was only limited association between cone penetration depth and household survey data. To promote the adoption of pit emptying, it is recommended that households be provided with information that supports pit emptying, such as latrine construction designs, local pit emptying options, and cost. This study indicates that the use of a penetrometer test in the field prior to pit latrine emptying may facilitate the selection of appropriate pit emptying technology. PMID:28165378

Delayed gastric emptying does not normalize after gluten withdrawal in adult celiac disease.

PubMed

Usai-Satta, Paolo; Oppia, Francesco; Scarpa, Mariella; Giannetti, Cristiana; Cabras, Francesco

2016-08-01

Objective Delayed gastric emptying has been frequently detected in patients with untreated celiac disease. According to several studies, gluten withdrawal showed to be effective in normalizing the gastric emptying rate. The aim of this study was to evaluate the gastric emptying rate of solids in patients with celiac disease before and after a gluten-free diet. Methods Twelve adult patients with celiac disease (age range 20-57 years) and 30 healthy controls (age range 30-54 years) underwent a (13)C-octanoic acid breath test to measure gastric emptying. Half emptying time (t1/2) and lag phase (tlag) were calculated. After at least 12 months of a gluten-free diet, celiac patients underwent a new (13)C-octanoic acid breath test. A symptom score was utilized to detect dyspeptic and malabsorption symptoms in all the patients. Results The gastric motility parameters, t1/2 and tlag, were significantly longer in patients than in controls. On a gluten-free diet, surprisingly, the gastric emptying did not normalize despite an improvement of symptom score. No significant correlation between abnormal gastric emptying and specific symptom patterns, anthropometric parameters or severity of histological damage was found. Conclusions This finding supports the hypothesis that gluten-driven mucosal inflammation might determine motor abnormalities by affecting smooth muscle contractility or impairing gut hormone function. The persistence of these abnormalities on a gluten free diet suggests the presence of a persistent low-grade mucosal inflammation with a permanent perturbation of the neuro-immunomodulatory regulation.

Validation of 13C-acetic acid breath test by measuring effects of loperamide, morphine, mosapride, and itopride on gastric emptying in mice.

PubMed

Matsumoto, Kenjiro; Kimura, Hiroshi; Tashima, Kimihito; Uchida, Masayuki; Horie, Syunji

2008-10-01

Several methods are used to evaluate gastric motility in rodents, but they all have technical limitations. Recent technical developments enable a convenient method to evaluate gastric motility. The (13)C-acetic acid breath test in rodents is a non-invasive and repeatable method that can be used without physical restraints. The present study aimed to validate the (13)C-acetic acid breath test by measuring the effects of loperamide, morphine, mosapride, and itopride on gastric emptying in mice. Loperamide (1-10 mg/kg) and morphine (1.25-10 mg/kg) slowed gastric emptying and decreased the maximum concentration (C(max)) and area under the curve (AUC(90 min)) value in a dose-dependent manner. Mosapride (0.2-5 mg/kg) accelerated gastric emptying and increased C(max) value. Mosapride (20 mg/kg) did not accelerate gastric emptying on the (13)C-breath test. Itopride (30 mg/kg, per os) significantly accelerated gastric emptying compared with the vehicle group. In a comparison with the conventional phenol red test, there was a correlation between the C(max) value of breath test and gastric emptying (%) of phenol red tests in treatment with loperamide or mosapride. These results indicate that the (13)C-acetic acid breath test is an accurate, noninvasive, and simple method for monitoring gastric emptying in mice. This method is useful to assess the effect of drugs and gut function pharmacologically.

The Wagner-Nelson method can generate an accurate gastric emptying flow curve from CO2 data obtained by a 13C-labeled substrate breath test.

PubMed

Sanaka, Masaki; Yamamoto, Takatsugu; Ishii, Tarou; Kuyama, Yasushi

2004-01-01

In pharmacokinetics, the Wagner-Nelson (W-N) method can accurately estimate the rate of drug absorption from its urinary elimination rate. A stable isotope (13C) breath test attempts to estimate the rate of absorption of 13C, as an index of gastric emptying rate, from the rate of pulmonary elimination of 13CO2. The time-gastric emptying curve determined by the breath test is quite different from that determined by scintigraphy or ultrasonography. In this report, we have shown that the W-N method can adjust the difference. The W-N equation to estimate gastric emptying from breath data is as follows: the fractional cumulative amount of gastric contents emptied by time t = Abreath (t)/Abreath (infinity) + (1/0.65).d[Abreath (t)/Abreath (infinity) ]/dt, where Abreath (t) = the cumulative recovery of 13CO2 in breath by time t and Abreath ( infinity ) = the ultimate cumulative 13CO2 recovery. The emptying flow curve generated by ultrasonography was compared with that generated by the W-N method-adjusted breath test in 6 volunteers. The emptying curves by the W-N method were almost identical to those by ultrasound. The W-N method can generate an accurate emptying flow curve from 13CO2 data, and it can adjust the difference between ultrasonography and the breath test. Copyright 2004 S. Karger AG, Basel

49 CFR 173.428 - Empty Class 7 (radioactive) materials packaging.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Empty Class 7 (radioactive) materials packaging... SHIPPERS-GENERAL REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS Class 7 (Radioactive) Materials § 173.428 Empty Class 7 (radioactive) materials packaging. A packaging which previously contained Class 7 (radioactive...

27 CFR 25.36 - Empty container storage.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Empty container storage. 25.36 Section 25.36 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL BEER Construction and Equipment Equipment § 25.36 Empty container storage...

27 CFR 25.36 - Empty container storage.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Empty container storage. 25.36 Section 25.36 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS BEER Construction and Equipment Equipment § 25.36 Empty container storage...

27 CFR 25.36 - Empty container storage.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Empty container storage. 25.36 Section 25.36 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS BEER Construction and Equipment Equipment § 25.36 Empty container storage...

27 CFR 25.36 - Empty container storage.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Empty container storage. 25.36 Section 25.36 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS BEER Construction and Equipment Equipment § 25.36 Empty container storage...

14 CFR 29.29 - Empty weight and corresponding center of gravity.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Empty weight and corresponding center of gravity. 29.29 Section 29.29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... weight and corresponding center of gravity. (a) The empty weight and corresponding center of gravity must...

14 CFR 27.29 - Empty weight and corresponding center of gravity.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Empty weight and corresponding center of gravity. 27.29 Section 27.29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... and corresponding center of gravity. (a) The empty weight and corresponding center of gravity must be...

14 CFR 27.29 - Empty weight and corresponding center of gravity.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Empty weight and corresponding center of gravity. 27.29 Section 27.29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... and corresponding center of gravity. (a) The empty weight and corresponding center of gravity must be...

14 CFR 23.29 - Empty weight and corresponding center of gravity.

Code of Federal Regulations, 2013 CFR

2013-01-01

... gravity. 23.29 Section 23.29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Flight General § 23.29 Empty weight and corresponding center of gravity. (a) The empty weight and corresponding center of gravity must be determined by weighing the airplane with— (1) Fixed ballast; (2...

14 CFR 27.29 - Empty weight and corresponding center of gravity.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Empty weight and corresponding center of gravity. 27.29 Section 27.29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... and corresponding center of gravity. (a) The empty weight and corresponding center of gravity must be...

14 CFR 25.29 - Empty weight and corresponding center of gravity.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Empty weight and corresponding center of gravity. 25.29 Section 25.29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... and corresponding center of gravity. (a) The empty weight and corresponding center of gravity must be...

14 CFR 25.29 - Empty weight and corresponding center of gravity.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Empty weight and corresponding center of gravity. 25.29 Section 25.29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... and corresponding center of gravity. (a) The empty weight and corresponding center of gravity must be...

14 CFR 29.29 - Empty weight and corresponding center of gravity.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Empty weight and corresponding center of gravity. 29.29 Section 29.29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... weight and corresponding center of gravity. (a) The empty weight and corresponding center of gravity must...

14 CFR 23.29 - Empty weight and corresponding center of gravity.

Code of Federal Regulations, 2010 CFR

2010-01-01

... gravity. 23.29 Section 23.29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Flight General § 23.29 Empty weight and corresponding center of gravity. (a) The empty weight and corresponding center of gravity must be determined by weighing the airplane with— (1) Fixed ballast; (2...

14 CFR 29.29 - Empty weight and corresponding center of gravity.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Empty weight and corresponding center of gravity. 29.29 Section 29.29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... weight and corresponding center of gravity. (a) The empty weight and corresponding center of gravity must...

14 CFR 25.29 - Empty weight and corresponding center of gravity.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Empty weight and corresponding center of gravity. 25.29 Section 25.29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... and corresponding center of gravity. (a) The empty weight and corresponding center of gravity must be...

14 CFR 27.29 - Empty weight and corresponding center of gravity.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Empty weight and corresponding center of gravity. 27.29 Section 27.29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... and corresponding center of gravity. (a) The empty weight and corresponding center of gravity must be...

14 CFR 29.29 - Empty weight and corresponding center of gravity.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Empty weight and corresponding center of gravity. 29.29 Section 29.29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... weight and corresponding center of gravity. (a) The empty weight and corresponding center of gravity must...

14 CFR 27.29 - Empty weight and corresponding center of gravity.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Empty weight and corresponding center of gravity. 27.29 Section 27.29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... and corresponding center of gravity. (a) The empty weight and corresponding center of gravity must be...

14 CFR 29.29 - Empty weight and corresponding center of gravity.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Empty weight and corresponding center of gravity. 29.29 Section 29.29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... weight and corresponding center of gravity. (a) The empty weight and corresponding center of gravity must...

14 CFR 25.29 - Empty weight and corresponding center of gravity.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Empty weight and corresponding center of gravity. 25.29 Section 25.29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... and corresponding center of gravity. (a) The empty weight and corresponding center of gravity must be...

14 CFR 23.29 - Empty weight and corresponding center of gravity.

Code of Federal Regulations, 2011 CFR

2011-01-01

... gravity. 23.29 Section 23.29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Flight General § 23.29 Empty weight and corresponding center of gravity. (a) The empty weight and corresponding center of gravity must be determined by weighing the airplane with— (1) Fixed ballast; (2...

14 CFR 23.29 - Empty weight and corresponding center of gravity.

Code of Federal Regulations, 2014 CFR

2014-01-01

... gravity. 23.29 Section 23.29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Flight General § 23.29 Empty weight and corresponding center of gravity. (a) The empty weight and corresponding center of gravity must be determined by weighing the airplane with— (1) Fixed ballast; (2...

14 CFR 25.29 - Empty weight and corresponding center of gravity.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Empty weight and corresponding center of gravity. 25.29 Section 25.29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... and corresponding center of gravity. (a) The empty weight and corresponding center of gravity must be...

14 CFR 23.29 - Empty weight and corresponding center of gravity.

Code of Federal Regulations, 2012 CFR

2012-01-01

... gravity. 23.29 Section 23.29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Flight General § 23.29 Empty weight and corresponding center of gravity. (a) The empty weight and corresponding center of gravity must be determined by weighing the airplane with— (1) Fixed ballast; (2...

Spherical nanocrystalline cellulose (NCC) from oil palm empty fruit bunch pulp via ultrasound assisted hydrolysis.

PubMed

Zianor Azrina, Z A; Beg, M Dalour H; Rosli, M Y; Ramli, Ridzuan; Junadi, Norhafzan; Alam, A K M Moshiul

2017-04-15

Nanocrystalline cellulose (NCC) was isolated from oil palm empty fruit bunch pulp (EFBP) using ultrasound assisted acid hydrolysis. The obtained NCC was analysed using FESEM, XRD, FTIR, and TGA, and compared with raw empty fruit bunch fibre (REFB), empty fruit bunch pulp (EFBP), and treated empty fruit bunch pulp (TEFBP). Based on FESEM analysis, it was found that NCC has a spherical shaped after acid hydrolysis with the assistance of ultrasound. This situation was different compared to previous studies that obtained rod-like shaped of NCC. Furthermore, the crystallinity of NCC is higher compared to REFB and EFBP. According to thermal stability, the NCC obtained shows remarkable sign of high thermal stability compared to REFB and EFBP. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of Jiangzhi tablet on gastrointestinal propulsive function in mice

NASA Astrophysics Data System (ADS)

Wang, Xiangrong; Geng, Xiuli; Zhao, Jingsheng; Fan, Lili; Zhang, Zhengchen

2018-04-01

This paper aims to study the effect of lipid-lowering tablets on gastric emptying and small intestinal propulsion in mice. Mice were randomly divided into control group, Digestant Pill group, Jiangzhi tablet group, middle dose and small dose, the mice gastric emptying phenolsulfonphthalein, gastric residual rate of phenol red indicator to evaluate the gastric emptying rate, residual rate of detection in mouse stomach; small intestine propulsion and selection of carbon ink as the experimental index. Effects were observed to promote the function of normal mice gastric emptying and intestine. The gastric emptying and small intestinal motor function of normal mice were all promoted by each administration group, and the effect was most obvious in small dose group. The effect of reducing blood lipid on gastrointestinal motility of mice ware obviously enhanced.

Effects of empty bins on image upscaling in capsule endoscopy

NASA Astrophysics Data System (ADS)

Rukundo, Olivier

2017-07-01

This paper presents a preliminary study of the effect of empty bins on image upscaling in capsule endoscopy. The presented study was conducted based on results of existing contrast enhancement and interpolation methods. A low contrast enhancement method based on pixels consecutiveness and modified bilinear weighting scheme has been developed to distinguish between necessary empty bins and unnecessary empty bins in the effort to minimize the number of empty bins in the input image, before further processing. Linear interpolation methods have been used for upscaling input images with stretched histograms. Upscaling error differences and similarity indices between pairs of interpolation methods have been quantified using the mean squared error and feature similarity index techniques. Simulation results demonstrated more promising effects using the developed method than other contrast enhancement methods mentioned.

Pit Latrine Emptying Behavior and Demand for Sanitation Services in Dar Es Salaam, Tanzania

PubMed Central

Jenkins, Marion W.; Cumming, Oliver; Cairncross, Sandy

2015-01-01

Pit latrines are the main form of sanitation in unplanned areas in many rapidly growing developing cities. Understanding demand for pit latrine fecal sludge management (FSM) services in these communities is important for designing demand-responsive sanitation services and policies to improve public health. We examine latrine emptying knowledge, attitudes, behavior, trends and rates of safe/unsafe emptying, and measure demand for a new hygienic latrine emptying service in unplanned communities in Dar Es Salaam (Dar), Tanzania, using data from a cross-sectional survey at 662 residential properties in 35 unplanned sub-wards across Dar, where 97% had pit latrines. A picture emerges of expensive and poor FSM service options for latrine owners, resulting in widespread fecal sludge exposure that is likely to increase unless addressed. Households delay emptying as long as possible, use full pits beyond what is safe, face high costs even for unhygienic emptying, and resort to unsafe practices like ‘flooding out’. We measured strong interest in and willingness to pay (WTP) for the new pit emptying service at 96% of residences; 57% were WTP ≥U.S. $17 to remove ≥200 L of sludge. Emerging policy recommendations for safe FSM in unplanned urban communities in Dar and elsewhere are discussed. PMID:25734790

A gamma variate model that includes stretched exponential is a better fit for gastric emptying data from mice

PubMed Central

Bajzer, Željko; Gibbons, Simon J.; Coleman, Heidi D.; Linden, David R.

2015-01-01

Noninvasive breath tests for gastric emptying are important techniques for understanding the changes in gastric motility that occur in disease or in response to drugs. Mice are often used as an animal model; however, the gamma variate model currently used for data analysis does not always fit the data appropriately. The aim of this study was to determine appropriate mathematical models to better fit mouse gastric emptying data including when two peaks are present in the gastric emptying curve. We fitted 175 gastric emptying data sets with two standard models (gamma variate and power exponential), with a gamma variate model that includes stretched exponential and with a proposed two-component model. The appropriateness of the fit was assessed by the Akaike Information Criterion. We found that extension of the gamma variate model to include a stretched exponential improves the fit, which allows for a better estimation of T1/2 and Tlag. When two distinct peaks in gastric emptying are present, a two-component model is required for the most appropriate fit. We conclude that use of a stretched exponential gamma variate model and when appropriate a two-component model will result in a better estimate of physiologically relevant parameters when analyzing mouse gastric emptying data. PMID:26045615

Exploring gastric emptying rate in minipigs: Effect of food type and pre-dosing of metoclopramide.

PubMed

Henze, Laura J; Griffin, Brendan T; Christiansen, Martin; Bundgaard, Christoffer; Langguth, Peter; Holm, René

2018-06-15

The present study investigated the gastric emptying rate in Göttingen minipigs pre- and post-prandial and evaluated the effect of metoclopramide on the same parameter, using paracetamol as an absorption marker. The pharmacokinetic evaluation of the obtained plasma concentration data for paracetamol demonstrated that the fastest gastric emptying rate was observed in the animals that were allowed access to normal pig food. There was no significant difference in the stomach emptying rate observed between fasted and fed minipigs, when fed either with a FDA standard breakfast or a nutritional energy drink. Pre-dosing minipigs with metoclopramide (0.2 or 0.4 mg/kg) did not demonstrate any effect on gastric emptying in either the fasted or fed state. The data in the present study demonstrated a relatively prolonged gastric emptying rate in mini-pigs both in the fasted and fed state, hence when conducting pharmacokinetic studies using minipigs, this should be taken into account when planning the plasma sampling time points. Further, as no difference could be observed in gastric emptying rate as a function of food, the data also suggest that the Göttingen mini-pigs seems less suited to predict for food effect studies than other species. Copyright © 2018 Elsevier B.V. All rights reserved.

The effects of consuming carbohydrate-electrolyte beverages on gastric emptying and fluid absorption during and following exercise.

PubMed

Murray, R

1987-01-01

A variety of beverages formulated to provide fluid, carbohydrates, and electrolytes during and following exercise are commercially available. Such 'sport drinks' commonly contain 4 to 8% carbohydrate (as glucose, fructose, sucrose or maltodextrins) and small amounts of electrolytes (most often sodium, potassium, and chloride). The efficacy of consuming such beverages has been questioned primarily because of concern that beverage carbohydrate content may inhibit gastric emptying rate and fluid absorption during exercise, thereby jeopardizing physiological homeostasis and impairing exercise performance. Gastric motor activity, and consequently gastric emptying rate, is governed by neural and humoral feedback provided by receptors found in the gastric musculature and proximal small intestine. Gastric emptying rate may be influenced by a variety of factors including, but not limited to, the caloric content, volume, osmolality, temperature, and pH of the ingested fluid, diurnal and interindividual variation, metabolic state (rest/exercise), and the ambient temperature. The caloric content of the ingested fluid appears to be the most important variable governing gastric emptying rate, providing a mean caloric efflux from the stomach of 2.0 to 2.5 kcal/min for ingested fluid volumes less than 400 ml. At rest, gastric emptying is inhibited by solutions containing calories in a manner independent of the nutrient source (i.e. carbohydrate, fat or protein). Consequently, plain water is known to empty from the stomachs of resting subjects at rates faster than solutions containing calories. Gastric emptying is increasingly inhibited as the caloric content of the ingested fluid increases. During moderate exercise (less than 75% VO2max), gastric emptying occurs at a rate similar to that during rest; more intense exercise appears to inhibit gastric emptying. When fluids are consumed at regular intervals throughout prolonged exercise (greater than 2 hours), postexercise aspiration of stomach contents reveals that solutions containing up to 10% carbohydrate empty at rates similar to plain water. There is ample physiological justification for the addition of glucose, fructose, sodium, potassium and chloride to fluid replacement beverages. Fluid absorption in the small intestine is stimulated by glucose and sodium (and to a lesser extent by fructose and other electrolytes). Glucose and sodium are absorbed via a common membrane carrier in the mucosal epithelium of the proximal small intestine. The potentiation of sodium uptake by glucose establishes an osmotic gradient for fluid absorption.(ABSTRACT TRUNCATED AT 400 WORDS)

Poor predictive value of breath hydrogen response for probiotic effects in IBS.

PubMed

Yao, Chu K; Barrett, Jacqueline S; Philpott, Hamish; Chung, Alvin R T; van Langenberg, Daniel; Garg, Mayur; Gibson, Peter R

2015-12-01

Previous observations suggested that an early rise in breath hydrogen after lactulose (ERBHAL) may identify patients with irritable bowel syndrome (IBS) likely to respond to probiotics. Therefore, we aimed to (i) investigate whether treatment with a probiotic changes breath hydrogen response in patients with ERBHAL and (ii) whether these changes identify patients who may benefit symptomatically from probiotics. In a randomized, double-blind, placebo-controlled trial, patients with IBS (Rome III) were randomized to either 65 mL/day fermented milk product containing probiotic (FMPP) or placebo for 6 weeks, followed by 6 weeks' open-label treatment and 6 weeks' withdrawal. Breath hydrogen responses to lactulose (15 g) and liquid-gastric emptying time were evaluated before and at the end of each treatment period. Symptoms were measured using a 100-mm visual analog scale. Loss of ERBHAL occurred in 36% of 23 patients receiving FMPP and 41% of 22 receiving placebo (P = 1.00). Amongst 40 patients who completed open-label FMPP treatment, ERBHAL was lost in a further 38%, continued in 25%, and regained in 10%. Similar variability occurred in the withdrawal phase. Variability was unrelated to changes in gastric emptying. No differences in symptom response were seen between treatment groups nor in relation to the loss or retention of ERBHAL. Breath hydrogen patterns after lactulose are poorly reproducible. No FMPP-specific effects on fermentation patterns or symptoms were observed. The presence of ERBHAL is not useful to predict symptomatic response to probiotic therapy in patients with IBS. © 2015 Journal of Gastroenterology and Hepatology Foundation and Wiley Publishing Asia Pty Ltd.

Outcomes of intradetrusor onabotulinum toxin A injection in patients with Parkinson's disease.

PubMed

Vurture, Gregory; Peyronnet, Benoit; Feigin, Andrew; Biagioni, Milton C; Gilbert, Rebecca; Rosenblum, Nirit; Frucht, Steven; Di Rocco, Alessandro; Nitti, Victor W; Brucker, Benjamin M

2018-05-16

To assess the safety and efficacy of intradetrusor onabotulinum toxin A injections for the treatment of overactive bladder (OAB) in patients with Parkinson's disease (PD). All PD patients who underwent intradetrusor injections of onabotulinum toxin A (BoNT-A) for storage symptoms between 2010 and 2017 were included in a retrospective study. A 100 U dose of BoNT-A (Botox®, Allergan Irvine, CA) was used for the first injection in all patients. The primary endpoint was clinical success defined as any subjective improvement in OAB symptoms self-assessed by the patients 4 weeks after the injections. Out of 24 patients analyzed, 19 reported improvement of their OAB symptoms 4 weeks after the first injection (79.2%) with complete resolution of urgency urinary incontinence in seven patients (29.1%; P < 0.001). The average post-void residual (PVR) increased significantly after the first injection from 17.6 to 125.3 mL (P < 0.001). Three of the patients had to start clean intermittent catheterization (CIC) after the first injection (12.5%). Out of 49 injections in total, only five caused incomplete bladder emptying requiring the use of CIC (10.2%). Higher pre-injection PVR was significantly associated with both a lower chance of symptomatic improvement (P = 0.04) and a higher risk of incomplete bladder emptying with institution of CIC (P = 0.047). Intradetrusor injections of BoNT-A 100 U appeared as a safe and effective option in PD patients with OAB symptoms and a low PVR before the injection. Higher preoperative PVR was the strongest predictor of both treatment failure and postoperative urinary retention requiring CIC. © 2018 Wiley Periodicals, Inc.

Pyloric sphincter characteristics using EndoFLIP® in gastroparesis.

PubMed

Saadi, M; Yu, D; Malik, Z; Parkman, H P; Schey, R

2018-04-27

Pyloric sphincter abnormalities may be detected in gastroparesis. Botulinum toxin A (BoNT/A) injection into the pylorus has been used to treat gastroparesis with varying results. The aim of the present article was to assess whether pyloric sphincter characteristics using the endoscopic functional lumen imaging probe (EndoFLIP ® ) with impedance planimetry in patients with gastroparesis correlated with symptoms, gastric emptying, and therapeutic response to pyloric sphincter BoNT/A injection. EndoFLIP ® study was performed on patients undergoing gastroparesis treatment with BoNT/A. The gastroparesis cardinal symptom index (GCSI) was applied prior to treatment and at post-treatment weeks 2, 4, 8, and 12. Forty-four patients were enrolled (30 with idiopathic gastroparesis, 14 with diabetic gastroparesis). Smaller pyloric diameter, cross-sectional area (CSA), and distensibility correlated with worse vomiting and retching severity at baseline. Greater gastric retention tended to correlate with decreased CSA and pyloric distensibility. BoNT/A treatment resulted in a significant decrease in the GCSI score at 2 and 4 weeks after treatment, but not at post-treatment weeks 8 or 12. Nausea, early satiety, postprandial fullness, and upper abdominal pain improved up to 12 weeks, whereas loss of appetite, stomach fullness, and stomach visibly larger improved only up to 4 weeks. Retching and vomiting failed to improve. Greater pyloric compliance at baseline correlated with greater improvement in early satiety and náusea at 8 weeks and greater pyloric distensibility correlated with improvement in upper abdominal pain. EndoFLIP ® characteristics of the pylorus provided important pathophysiologic information in patients with gastroparesis, in relation to symptoms, gastric emptying, and predicting the response to treatment directed at the pylorus. Copyright © 2018 Asociación Mexicana de Gastroenterología. Publicado por Masson Doyma México S.A. All rights reserved.

Contrast-Enhanced Magnetic Resonance Imaging of Gastric Emptying and Motility in Rats.

PubMed

Lu, Kun-Han; Cao, Jiayue; Oleson, Steven Thomas; Powley, Terry L; Liu, Zhongming

2017-11-01

The assessment of gastric emptying and motility in humans and animals typically requires radioactive imaging or invasive measurements. Here, we developed a robust strategy to image and characterize gastric emptying and motility in rats based on contrast-enhanced magnetic resonance imaging (MRI) and computer-assisted image processing. The animals were trained to naturally consume a gadolinium-labeled dietgel while bypassing any need for oral gavage. Following this test meal, the animals were scanned under low-dose anesthesia for high-resolution T1-weighted MRI in 7 Tesla, visualizing the time-varying distribution of the meal with greatly enhanced contrast against non-gastrointestinal (GI) tissues. Such contrast-enhanced images not only depicted the gastric anatomy, but also captured and quantified stomach emptying, intestinal filling, antral contraction, and intestinal absorption with fully automated image processing. Over four postingestion hours, the stomach emptied by 27%, largely attributed to the emptying of the forestomach rather than the corpus and the antrum, and most notable during the first 30 min. Stomach emptying was accompanied by intestinal filling for the first 2 h, whereas afterward intestinal absorption was observable as cumulative contrast enhancement in the renal medulla. The antral contraction was captured as a peristaltic wave propagating from the proximal to distal antrum. The frequency, velocity, and amplitude of the antral contraction were on average 6.34 ± 0.07 contractions per minute, 0.67 ± 0.01 mm/s, and 30.58 ± 1.03%, respectively. These results demonstrate an optimized MRI-based strategy to assess gastric emptying and motility in healthy rats, paving the way for using this technique to understand GI diseases, or test new therapeutics in rat models.The assessment of gastric emptying and motility in humans and animals typically requires radioactive imaging or invasive measurements. Here, we developed a robust strategy to image and characterize gastric emptying and motility in rats based on contrast-enhanced magnetic resonance imaging (MRI) and computer-assisted image processing. The animals were trained to naturally consume a gadolinium-labeled dietgel while bypassing any need for oral gavage. Following this test meal, the animals were scanned under low-dose anesthesia for high-resolution T1-weighted MRI in 7 Tesla, visualizing the time-varying distribution of the meal with greatly enhanced contrast against non-gastrointestinal (GI) tissues. Such contrast-enhanced images not only depicted the gastric anatomy, but also captured and quantified stomach emptying, intestinal filling, antral contraction, and intestinal absorption with fully automated image processing. Over four postingestion hours, the stomach emptied by 27%, largely attributed to the emptying of the forestomach rather than the corpus and the antrum, and most notable during the first 30 min. Stomach emptying was accompanied by intestinal filling for the first 2 h, whereas afterward intestinal absorption was observable as cumulative contrast enhancement in the renal medulla. The antral contraction was captured as a peristaltic wave propagating from the proximal to distal antrum. The frequency, velocity, and amplitude of the antral contraction were on average 6.34 ± 0.07 contractions per minute, 0.67 ± 0.01 mm/s, and 30.58 ± 1.03%, respectively. These results demonstrate an optimized MRI-based strategy to assess gastric emptying and motility in healthy rats, paving the way for using this technique to understand GI diseases, or test new therapeutics in rat models.

Evaluation of an anaerobic digestion system for processing CELSS crop residues for resource recovery

NASA Astrophysics Data System (ADS)

Strayer, R. F.; Finger, B. W.; Alazraki, M. P.

1997-01-01

Three bioreactors, connected in series, were used to process CELSS potato residues for recovery of resources. The first stage was an anaerobic digestor (8 L working volume; cow rumen contents inoculum; fed-batch; 8 day retention time; feed rate 25 gdw day^-1) that converted 33% of feed (dry weight loss) to CO_2 and ``volatile fatty acids'' (vfa, 83:8:8 mmolar ratio acetic:propionic:butyric). High nitrate-N in the potato residue feed was absent in the anaerobic effluent, with a high portion converted to NH_4^+-N and the remainder unaccounted and probably lost to denitrification and NH_4^+ volatilization. Liquid anaerobic effluent was fed to an aerobic, yeast biomass production vessel (2 L volume; Candida ingens inoculum; batch [pellicle] growth; 2 day retention time) where the VFAs and some NH_4^+-N were converted into yeast biomass. Yeast yields accounted for up to 8% of potato residue fed into the anaerobic bioreactor. The third bioreactor (0.5 L liquid working volume; commercial nitrifier inoculum; packed-bed biofilm; continuous yeast effluent feed; recirculating; constant volume; 2 day hydraulic retention time) was used to convert successfully the remaining NH_4^+-N into nitrate-N (preferred form of N for CELSS crop production) and to remove the remaining degradable soluble organic carbon. Effluents from the last two stages were used for partial replenishment of minerals for hydroponic potato production.

Evaluation of an Anaerobic Digestion System for Processing CELSS Crop Residues for Resource Recovery

NASA Technical Reports Server (NTRS)

Strayer, R. F.; Finger, B. W.; Alazraki, M. P.

1997-01-01

Three bioreactors, connected in series, were used to process CELSS potato residues for recovery of resources. The first stage was an anaerobic digestor (8 L working volume; cow rumen contents inoculum; fed-batch; 8 day retention time; feed rate 25 gdw/day) that converted 33% of feed (dry weight loss) to CO2 and "volatile fatty acids" (vfa, 83:8:8 mmolar ratio acetic:propionic:butyric). High nitrate-N in the potato residue feed was absent in the anaerobic effluent, with a high portion converted to NH4(+)-N and the remainder unaccounted and probably lost to denitrification and NH4(+) volatilization. Liquid anaerobic effluent was fed to an aerobic, yeast biomass production vessel (2 L volume; Candida ingens inoculum; batch [pellicle] growth; 2 day retention time) where the VFAs and some NH4(+)-N were converted into yeast biomass. Yeast yields accounted for up to 8% of potato residue fed into the anaerobic bioreactor. The third bioreactor (0.5 L liquid working volume; commercial nitrifier inoculum; packed-bed biofilm; continuous yeast effluent feed; recirculating; constant volume; 2 day hydraulic retention time) was used to convert successfully the remaining NH4(+)-N into nitrate-N (preferred form of N for CELSS crop production) and to remove the remaining degradable soluble organic carbon. Effluents from the last two stages were used for partial replenishment of minerals for hydroponic potato production.

3D inverse-opal structured Li4Ti5O12 Anode for fast Li-Ion storage capabilities

NASA Astrophysics Data System (ADS)

Kim, Dahye; Quang, Nguyen Duc; Hien, Truong Thi; Chinh, Nguyen Duc; Kim, Chunjoong; Kim, Dojin

2017-11-01

Since the demand for high power Li-ion batteries (LIBs) is increasing, spinel-structured lithium titanate, Li4Ti5O12 (LTO), as the anode material has attracted great attention because of its excellent cycle retention, good thermal stability, high rate capability, and so on. However, LTO shows relatively low conductivity due to empty 3 d orbital of Ti4+ state. Nanoscale architectures can shorten electron conduction path, thus such low electronic conductivity can be overcome while Li+ can be easily accessed due to large surface area. Herein, three dimensional bicontinuous LTO electrodes were prepared via close-packed self-assembly with polystyrene (PS) spheres followed by removal of them, which leads to no blockage of Li+ ion transportation pathways as well as fast electron conduction. 3D bicontinuous LTO electrodes showed high-rate lithium storage capability (103 mAh/g at 20 C), which is promising as the power sources that require rapid electrochemical response.[Figure not available: see fulltext.

The effect of high energy ion beam analysis on D trapping in W

NASA Astrophysics Data System (ADS)

Finlay, T. J.; Davis, J. W.; Schwarz-Selinger, T.; Haasz, A. A.

2017-12-01

High energy ion beam analyses (IBA) are invaluable for measuring concentration depth profiles of light elements in solid materials, and important in the study of fusion fuel retention in tokamaks. Polycrystalline W specimens were implanted at 300 and 500 K, 5-10 × 1023 D m-2 fluence, with deuterium-only and simultaneous D-3%He ion beams. Selected specimens were analysed by elastic recoil detection analysis (ERDA) and/or nuclear reaction analysis (NRA). All specimens were measured by thermal desorption spectroscopy (TDS). The D TDS spectra show an extra peak at 900-1000 K following ERDA and/or NRA measurements. The peak height appears to correlate with the amount of D initially trapped beyond the calculated IBA probe beam peak damage depth. Similar to pre-implantation damage scenarios, the IBA probe beam creates empty high energy traps which later retrap D atoms during TDS heating, which is supported by modelling experimental results using the Tritium Migration Analysis Program.

The addition of locust bean gum but not water delayed the gastric emptying rate of a nutrient semisolid meal in healthy subjects

PubMed Central

Darwiche, Gassan; Björgell, Ola; Almér, Lars-olof

2003-01-01

Background Most of the previous studies regarding the effects of gel-forming fibres have considered the gastric emptying of liquid or solid meals after the addition of pectin or guar gum. The influence of locust bean gum, on gastric emptying of nutrient semisolid meals in humans has been less well studied, despite its common occurrence in foods. Using a standardised ultrasound method, this study was aimed at investigating if the gastric emptying in healthy subjects could be influenced by adding locust been gum, a widely used thickening agent, or water directly into a nutrient semisolid test meal. Methods The viscosity of a basic test meal (300 g rice pudding, 330 kcal) was increased by adding Nestargel (6 g, 2.4 kcal), containing viscous dietary fibres (96.5%) provided as seed flour of locust bean gum, and decreased by adding 100 ml of water. Gastric emptying of these three test meals were evaluated in fifteen healthy non-smoking volunteers, using ultrasound measurements of the gastric antral area to estimate the gastric emptying rate (GER). Results The median value of GER with the basic test meal (rice pudding) was estimated at 63 %, (range 47 to 84 %), (the first quartile = 61 %, the third quartile = 69 %). Increasing the viscosity of the rice pudding by adding Nestargel, resulted in significantly lower gastric emptying rates (p < 0.01), median GER 54 %, (range 7 to 71 %), (the first quartile = 48 %, the third quartile = 60 %). When the viscosity of the rice pudding was decreased (basic test meal added with water), the difference in median GER 65 %, (range 38 to 79 %), (the first quartile = 56 %, the third quartile = 71 %) was not significantly different (p = 0.28) compared to the GER of the basic test meal. Conclusions We conclude that the addition of locust bean gum to a nutrient semisolid meal has a major impact on gastric emptying by delaying the emptying rate, but that the addition of water to this test meal has no influence on gastric emptying in healthy subjects. PMID:12793910

The addition of locust bean gum but not water delayed the gastric emptying rate of a nutrient semisolid meal in healthy subjects.

PubMed

Darwiche, Gassan; Björgell, Ola; Almér, Lars-Olof

2003-06-06

Most of the previous studies regarding the effects of gel-forming fibres have considered the gastric emptying of liquid or solid meals after the addition of pectin or guar gum. The influence of locust bean gum, on gastric emptying of nutrient semisolid meals in humans has been less well studied, despite its common occurrence in foods. Using a standardised ultrasound method, this study was aimed at investigating if the gastric emptying in healthy subjects could be influenced by adding locust been gum, a widely used thickening agent, or water directly into a nutrient semisolid test meal. The viscosity of a basic test meal (300 g rice pudding, 330 kcal) was increased by adding Nestargel (6 g, 2.4 kcal), containing viscous dietary fibres (96.5%) provided as seed flour of locust bean gum, and decreased by adding 100 ml of water. Gastric emptying of these three test meals were evaluated in fifteen healthy non-smoking volunteers, using ultrasound measurements of the gastric antral area to estimate the gastric emptying rate (GER). The median value of GER with the basic test meal (rice pudding) was estimated at 63%, (range 47 to 84%), (the first quartile = 61%, the third quartile = 69%). Increasing the viscosity of the rice pudding by adding Nestargel, resulted in significantly lower gastric emptying rates (p < 0.01), median GER 54%, (range 7 to 71%), (the first quartile = 48%, the third quartile = 60%). When the viscosity of the rice pudding was decreased (basic test meal added with water), the difference in median GER 65%, (range 38 to 79%), (the first quartile = 56%, the third quartile = 71%) was not significantly different (p = 0.28) compared to the GER of the basic test meal. We conclude that the addition of locust bean gum to a nutrient semisolid meal has a major impact on gastric emptying by delaying the emptying rate, but that the addition of water to this test meal has no influence on gastric emptying in healthy subjects.

Determination of solid- and liquid-phase gastric emptying half times in cats by use of nuclear scintigraphy.

PubMed

Costello, M; Papasouliotis, K; Barr, F J; Gruffydd-Jones, T J; Caney, S M

1999-10-01

To use nuclear scintigraphy to establish a range of gastric emptying half times (t1/2) following a liquid or solid meal in nonsedated cats. 12 clinically normal 3-year-old domestic shorthair cats. A test meal of 75 g of scrambled eggs labeled with technetium Tc 99m tin colloid was fed to 10 of the cats, and solid-phase gastric emptying t1/2 were determined by use of nuclear scintigraphy. In a separate experiment, 8 of these cats plus an additional 2 cats were fed 18 ml (n = 5) or 36 ml (n = 5) of a nutrient liquid meal labeled with technetium Tc 99m pentetate. Liquid-phase gastric emptying t1/2 then were determined by use of scintigraphy. Solid-phase gastric emptying t1/2 were between 210 and 769 minutes (median, 330 minutes). Median liquid-phase gastric emptying t1/2 after ingestion of 18 or 36 ml of the test meal were 67 minutes (range, 60 to 96 minutes) and 117 minutes (range, 101 to 170 minutes), respectively. The median t1/2 determined for cats receiving 18 ml of the radiolabeled liquid was significantly less than that determined for cats receiving 36 ml of the test meal. The protocol was tolerated by nonsedated cats. Solid-phase gastric emptying t1/2 were prolonged, compared with liquid-phase t1/2, and a major factor governing the emptying rate of liquids was the volume consumed. Nuclear scintigraphy may prove useful in assessing gastric motility disorders in cats.

Correlation Between Gastric Emptying and Gastric Adaptive Relaxation Influenced by Amino Acids

PubMed Central

Uchida, Masayuki; Kobayashi, Orie; Saito, Chizuru

2017-01-01

Background/Aims Amino acids have many physiological activities. We report the correlation between gastric emptying and gastric adaptive relaxation using tryptophan and amino acids with a straight alkyl chain, hydroxylated chain, and branched chain. Here we sought to further clarify the correlation between gastric emptying and gastric adaptive relaxation by using other amino acids. Methods In Sprague-Dawley rats, gastric emptying was evaluated by a breath test using [1-13C] acetic acid. The expired 13CO2 pattern, Tmax, Cmax, and AUC120min values were used as evaluation items. Gastric adaptive relaxation was evaluated in a barostat experiment. Individual amino acids (1 g/kg) were administered orally 30 minutes before each breath test or barostat test. Results L-phenylalanine and L-tyrosine did not influence gastric emptying. All other amino acids, ie, L-proline, L-histidine, L-cysteine, L-methionine, L-aspartic acid, L-glutamic acid, L-asparagine, L-arginine, L-glutamine, and L-lysine significantly delayed and inhibited gastric emptying. L-Cysteine and L-aspartic acid significantly enhanced and L-methionine and L-glutamine significantly inhibited gastric adaptive relaxation. L-Phenylalanine moved the balloon toward the antrum, suggesting strong contraction of the fundus. Tmax showed a significant positive correlation (r = 0.709), and Cmax and AUC120min each showed negative correlations (r = 0.613 and 0.667, respectively) with gastric adaptive relaxation. Conclusion From the above findings, it was found that a close correlation exists between gastric emptying and adaptive relaxation, suggesting that enhanced gastric adaptive relaxation inhibits gastric emptying. PMID:28335103

Production of biohythane from food waste via an integrated system of continuously stirred tank and anaerobic fixed bed reactors.

PubMed

Yeshanew, Martha M; Frunzo, Luigi; Pirozzi, Francesco; Lens, Piet N L; Esposito, Giovanni

2016-11-01

The continuous production of biohythane (mixture of biohydrogen and methane) from food waste using an integrated system of a continuously stirred tank reactor (CSTR) and anaerobic fixed bed reactor (AFBR) was carried out in this study. The system performance was evaluated for an operation period of 200days, by stepwise shortening the hydraulic retention time (HRT). An increasing trend of biohydrogen in the CSTR and methane production rate in the AFBR was observed regardless of the HRT shortening. The highest biohydrogen yield in the CSTR and methane yield in the AFBR were 115.2 (±5.3)L H2/kgVSadded and 334.7 (±18.6)L CH4/kgCODadded, respectively. The AFBR presented a stable operation and excellent performance, indicated by the increased methane production rate at each shortened HRT. Besides, recirculation of the AFBR effluent to the CSTR was effective in providing alkalinity, maintaining the pH in optimal ranges (5.0-5.3) for the hydrogen producing bacteria. Copyright © 2016 Elsevier Ltd. All rights reserved.

Treatment of petroleum refinery wastewater using a sequential anaerobic-aerobic moving-bed biofilm reactor system based on suspended ceramsite.

PubMed

Lu, Mang; Gu, Li-Peng; Xu, Wen-Hao

2013-01-01

In this study, a novel suspended ceramsite was prepared, which has high strength, optimum density (close to water), and high porosity. The ceramsite was used to feed a moving-bed biofilm reactor (MBBR) system with an anaerobic-aerobic (A/O) arrangement to treat petroleum refinery wastewater for simultaneous removal of chemical oxygen demand (COD) and ammonium. The hydraulic retention time (HRT) of the anaerobic-aerobic MBBR system was varied from 72 to 18 h. The anaerobic-aerobic system had a strong tolerance to shock loading. Compared with the professional emission standard of China, the effluent concentrations of COD and NH3-N in the system could satisfy grade I at HRTs of 72 and 36 h, and grade II at HRT of 18 h. The average sludge yield of the anaerobic reactor was estimated to be 0.0575 g suspended solid/g CODremoved. This work demonstrated that the anaerobic-aerobic MBBR system using the suspended ceramsite as bio-carrier could be applied to achieving high wastewater treatment efficiency.

Enzymatic production of biodiesel from waste cooking oil in a packed-bed reactor: an engineering approach to separation of hydrophilic impurities.

PubMed

Hama, Shinji; Yoshida, Ayumi; Tamadani, Naoki; Noda, Hideo; Kondo, Akihiko

2013-05-01

An engineering approach was applied to an efficient biodiesel production from waste cooking oil. In this work, an enzymatic packed-bed reactor (PBR) was integrated with a glycerol-separating system and used successfully for methanolysis, yielding a methyl ester content of 94.3% and glycerol removal of 99.7%. In the glycerol-separating system with enhanced retention time, the effluent contained lesser amounts of glycerol and methanol than those in the unmodified system, suggesting its promising ability to remove hydrophilic impurities from the oil layer. The PBR system was also applied to oils with high acid values, in which fatty acids could be esterified and the large amount of water was extracted using the glycerol-separating system. The long-term operation demonstrated the high lipase stability affording less than 0.2% residual triglyceride in 22 batches. Therefore, the PBR system, which facilitates the separation of hydrophilic impurities, is applicable to the enzymatic biodiesel production from waste cooking oil. Copyright © 2012 Elsevier Ltd. All rights reserved.

Anaerobic digestion of municipal wastewater sludges using anaerobic fluidized bed bioreactor.

PubMed

Mustafa, Nizar; Elbeshbishy, Elsayed; Nakhla, George; Zhu, Jesse

2014-11-01

The anaerobic digestion of primary sludge (PS) and thickened waste activated sludge (TWAS) using an anaerobic fluidized bed bioreactor (AnFBR) employing zeolite particles as the carrier media was investigated at different organic loading rates (OLRs). PS was tested at OLRs from 4.2 to 39kgCOD/m(3)-d corresponding to hydraulic retention times (HRTs) from 1.0 to 8.9days. The highest COD removal and VSS destruction efficiencies for primary sludge of 85% and 88%, respectively, were achieved at an HRT of 8.9days and OLR of 4.2kgCOD/m(3)-d. For TWAS, VSS destruction efficiencies varied from 42% at an HRT of 2.6days and OLR of 13.1kgCOD/m(3)-d to 69% at an HRT of 8.8days and an OLR of 4.2kgCOD/m(3)-d. The first-order COD biodegradation rates in the AnFBR for PS and TWAS were 0.4d(-1) and 0.1d(-1), respectively, almost double the rates in conventional high-rate digesters. Copyright © 2014 Elsevier Ltd. All rights reserved.

Evaluation of an integrated sponge--granular activated carbon fluidized bed bioreactor for treating primary treated sewage effluent.

PubMed

Xing, W; Ngo, H H; Guo, W S; Listowski, A; Cullum, P

2011-05-01

An integrated fluidized bed bioreactor (iFBBR) was designed to incorporate an aerobic sponge FBBR (ASB-FBBR) into an anoxic granular activated carbon FBBR (GAC-FBBR). This iFBBR was operated with and without adding a new starch based flocculant (NSBF) to treat synthetic primary treated sewage effluent (PTSE). The NSBF contains starch based cationic flocculants and trace nutrients. The results indicate that the iFBBR with NSBF addition could remove more than 93% dissolved organic carbon (DOC), 61% total nitrogen (T-N) and 60% total phosphorus (T-P) at just a very short hydraulic retention time of 50 min. The optimum frequency of adding NSBF to the iFFBR is four times per day. As a pretreatment to microfiltration, the iFFBR could increase 5L/m(2)h of critical flux thus reducing the membrane fouling. In addition, better microbial activity was also observed with high DO consumption (>66%) and specific oxygen uptake rate (>35 mg O(2)/g VSS h). Copyright © 2010 Elsevier Ltd. All rights reserved.

Treatment of thin stillage in a high-rate anaerobic fluidized bed bioreactor (AFBR).

PubMed

Andalib, Mehran; Hafez, Hisham; Elbeshbishy, Elsayed; Nakhla, George; Zhu, Jesse

2012-10-01

The primary objective of this work was to investigate the treatability of thin stillage as a by-product of bioethanol production plants using an anaerobic fluidized bed bioreactor (AFBR) employing zeolite with average diameter of (d(m)) of 425-610 μm and specific surface area (SSA) of 26.5m(2)/g as the carrier media. Despite the very high strength of thin stillage with chemical oxygen demand of 130,000 mg TCOD/L and suspended solids of 47,000 mg TSS/L, the AFBR showed up to 88% TCOD and 78% TSS removal at very high organic and solids loading rates (OLR and SLR) of 29 kg COD/m(3)d and 10.5 kg TSS/m(3)d respectively and hydraulic retention time (HRT) of 3.5 days. Methane production rates of up to 160 L/d at the steady state equivalent to 40 L(CH4)/L(thin stillage)d and biogas production rate per reactor volume of 15.8L(gas)/L(reactor)d were achieved. Copyright © 2012 Elsevier Ltd. All rights reserved.

Organic loading rate impact on biohydrogen production and microbial communities at anaerobic fluidized thermophilic bed reactors treating sugarcane stillage.

PubMed

Santos, Samantha Christine; Rosa, Paula Rúbia Ferreira; Sakamoto, Isabel Kimiko; Varesche, Maria Bernadete Amâncio; Silva, Edson Luiz

2014-05-01

This study aimed to evaluate the effect of high organic loading rates (OLR) (60.0-480.00 kg COD m(-3)d(-1)) on biohydrogen production at 55°C, from sugarcane stillage for 15,000 and 20,000 mg CODL(-1), in two anaerobic fluidized bed reactors (AFBR1 and AFBR2). It was obtained, for H2 yield and content, a decreasing trend by increasing the OLR. The maximum H2 yield was observed in AFBR1 (2.23 mmol g COD added(-1)). The volumetric H2 production was proportionally related to the applied hydraulic retention time (HRT) of 6, 4, 2 and 1h and verified in AFBR1 the highest value (1.49 L H2 h(-1)L(-1)). Among the organic acids obtained, there was a predominance of lactic acid (7.5-22.5%) and butyric acid (9.4-23.8%). The microbial population was set with hydrogen-producing fermenters (Megasphaera sp.) and other organisms (Lactobacillus sp.). Copyright © 2014 Elsevier Ltd. All rights reserved.

Ceramic breeder research and development: progress and focus

NASA Astrophysics Data System (ADS)

van der Laan, J. G.; Kawamura, H.; Roux, N.; Yamaki, D.

2000-12-01

The world-wide efforts on ceramic breeder materials in the last two years concerned Li2O, Li4SiO4, Li2TiO3 and Li2ZrO3, with a clear emphasis on the development of Li2TiO3. Pebble-manufacturing processes have been developed up to a 10 kg scale. Characterisation of materials has advanced. A jump-wise progress is observed in the characterisation of pebble-beds, in particular of their thermo-mechanical behaviour. Thermal property data are still limited. A number of breeder materials have been or are being irradiated in material test reactors like HFR and JMTR. The EXOTIC-8 series of in-pile experiments is a major source of tritium release data. This paper discusses the technical advancements and proposes a focus for further research and development (R&D) : pebble-bed mechanical and thermal behaviour and its interactions with the blanket structure as a function of temperature, burn-up, irradiation dose and time; tritium release and retention properties; determination of the key factors limiting blanket life.

Performance evaluation and phylogenetic characterization of anaerobic fluidized bed reactors using ground tire and pet as support materials for biohydrogen production.

PubMed

Barros, Aruana Rocha; Adorno, Maria Angela Tallarico; Sakamoto, Isabel Kimiko; Maintinguer, Sandra Imaculada; Varesche, Maria Bernadete Amâncio; Silva, Edson Luiz

2011-02-01

This study evaluated two different support materials (ground tire and polyethylene terephthalate [PET]) for biohydrogen production in an anaerobic fluidized bed reactor (AFBR) treating synthetic wastewater containing glucose (4000 mg L(-1)). The AFBR, which contained either ground tire (R1) or PET (R2) as support materials, were inoculated with thermally pretreated anaerobic sludge and operated at a temperature of 30°C. The AFBR were operated with a range of hydraulic retention times (HRT) between 1 and 8h. The reactor R1 operating with a HRT of 2h showed better performance than reactor R2, reaching a maximum hydrogen yield of 2.25 mol H(2)mol(-1) glucose with 1.3mg of biomass (as the total volatile solids) attached to each gram of ground tire. Subsequent 16S rRNA gene sequencing and phylogenetic analysis of particle samples revealed that reactor R1 favored the presence of hydrogen-producing bacteria such as Clostridium, Bacillus, and Enterobacter. Copyright © 2010 Elsevier Ltd. All rights reserved.

Low energy single-staged anaerobic fluidized bed ceramic membrane bioreactor (AFCMBR) for wastewater treatment.

PubMed

Aslam, Muhammad; McCarty, Perry L; Shin, Chungheon; Bae, Jaeho; Kim, Jeonghwan

2017-09-01

An aluminum dioxide (Al 2 O 3 ) ceramic membrane was used in a single-stage anaerobic fluidized bed ceramic membrane bioreactor (AFCMBR) for low-strength wastewater treatment. The AFCMBR was operated continuously for 395days at 25°C using a synthetic wastewater having a chemical oxygen demand (COD) averaging 260mg/L. A membrane net flux as high as 14.5-17L/m 2 h was achieved with only periodic maintenance cleaning, obtained by adding 25mg/L of sodium hypochlorite solution. No adverse effect of the maintenance cleaning on organic removal was observed. An average SCOD in the membrane permeate of 23mg/L was achieved with a 1h hydraulic retention time (HRT). Biosolids production averaged 0.014±0.007gVSS/gCOD removed. The estimated electrical energy required to operate the AFCMBR system was 0.039kWh/m 3 , which is only about 17% of the electrical energy that could be generated with the methane produced. Copyright © 2017 Elsevier Ltd. All rights reserved.

Efficient Removal of Retained Intracardiac Air Utilizing Buoyancy.

PubMed

Orihashi, Kazumasa

2016-12-01

Retained intracardiac air has been an important issue in cardiac surgery. Although echo visualization has allowed detection of air and guided deairing procedures, adequate air removal is not always attained. Actually it has been attempted in each surgeon's manner without solid standard or evidence. Basically buoyancy is responsible for air retention as well as difficult deairing. This paper is aimed to present the author's current measures of deairing, which turn this property of air into efficient removal, as test bed for discussion on this long-standing but pending issue. Copyright © 2016 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

14 CFR 135.185 - Empty weight and center of gravity: Currency requirement.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Empty weight and center of gravity... ON BOARD SUCH AIRCRAFT Aircraft and Equipment § 135.185 Empty weight and center of gravity: Currency... gravity are calculated from values established by actual weighing of the aircraft within the preceding 36...

14 CFR 135.185 - Empty weight and center of gravity: Currency requirement.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Empty weight and center of gravity... ON BOARD SUCH AIRCRAFT Aircraft and Equipment § 135.185 Empty weight and center of gravity: Currency... gravity are calculated from values established by actual weighing of the aircraft within the preceding 36...

14 CFR 135.185 - Empty weight and center of gravity: Currency requirement.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Empty weight and center of gravity... ON BOARD SUCH AIRCRAFT Aircraft and Equipment § 135.185 Empty weight and center of gravity: Currency... gravity are calculated from values established by actual weighing of the aircraft within the preceding 36...

14 CFR 135.185 - Empty weight and center of gravity: Currency requirement.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Empty weight and center of gravity... ON BOARD SUCH AIRCRAFT Aircraft and Equipment § 135.185 Empty weight and center of gravity: Currency... gravity are calculated from values established by actual weighing of the aircraft within the preceding 36...

14 CFR 135.185 - Empty weight and center of gravity: Currency requirement.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Empty weight and center of gravity... ON BOARD SUCH AIRCRAFT Aircraft and Equipment § 135.185 Empty weight and center of gravity: Currency... gravity are calculated from values established by actual weighing of the aircraft within the preceding 36...

Why the self is empty. Toward a historically situated psychology.

PubMed

Cushman, P

1990-05-01

This article presents a contextualized treatment of the current configuration of self, some of the pathologies that plague it, and the technologies that attempt to heal it. Of particular interest is the historical shift from the Victorian, sexually restricted self to the post-World War II empty self. The empty self is soothed and made cohesive by becoming "filled up" with food, consumer products, and celebrities. Its historical antecedents, economic constituents, and political consequences are the focus of this article. The two professions most responsible for healing the empty self, advertising and psychotherapy, find themselves in a bind: They must treat a psychological symptom without being able to address its historical causes. Both circumvent the bind by employing the life-style solution, a strategy that attempts to heal by covertly filling the empty self with the accoutrements, values, and mannerisms of idealized figures. This strategy solves an old problem but creates new ones, including an opportunity for abuse by exploitive therapists, cult leaders, and politicians. Psychology's role in constructing the empty self, and thus reproducing the current hierarchy of power and privilege, is examined.

A Model for Hydraulic Properties Based on Angular Pores with Lognormal Size Distribution

NASA Astrophysics Data System (ADS)

Durner, W.; Diamantopoulos, E.

2014-12-01

Soil water retention and unsaturated hydraulic conductivity curves are mandatory for modeling water flow in soils. It is a common approach to measure few points of the water retention curve and to calculate the hydraulic conductivity curve by assuming that the soil can be represented as a bundle of capillary tubes. Both curves are then used to predict water flow at larger spatial scales. However, the predictive power of these curves is often very limited. This can be very easily illustrated if we measure the soil hydraulic properties (SHPs) for a drainage experiment and then use these properties to predict the water flow in the case of imbibition. Further complications arise from the incomplete wetting of water at the solid matrix which results in finite values of the contact angles between the solid-water-air interfaces. To address these problems we present a physically-based model for hysteretic SHPs. This model is based on bundles of angular pores. Hysteresis for individual pores is caused by (i) different snap-off pressures during filling and emptying of single angular pores and (ii) by different advancing and receding contact angles for fluids that are not perfectly wettable. We derive a model of hydraulic conductivity as a function of contact angle by assuming flow perpendicular to pore cross sections and present closed-form expressions for both the sample scale water retention and hydraulic conductivity function by assuming a log-normal statistical distribution of pore size. We tested the new model against drainage and imbibition experiments for various sandy materials which were conducted with various liquids of differing wettability. The model described both imbibition and drainage experiments very well by assuming a unique pore size distribution of the sample and a zero contact angle for the perfectly wetting liquid. Eventually, we see the possibility to relate the particle size distribution with a model which describes the SHPs.

Solid Test Meal to Measure the Gastric Emptying with Magnetogastrography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reynaga-Ornelas, M. G.; Roca-Chiapas, J. M. de ls; Cordova-Fraga, T.

2008-08-11

The gastric emptying is the time of evacuating the food ingested from the stomach to the duodenum in a controlled rate. Diverse studies express the results of the gastric emptying in form of half-time (t{sub 1/2}). The Magnetogastrography (MGG) is a biomagnetic technique that has the advantage of not being invasive, radiation free and does not interfere with the privacy of the subject. The objective was to analyze the magnetic signal of magnetic tracers mixed in a solid food to measure gastric emptying using Magnetogastrography. The ingested test meal displayed a magnetic signal, which served to obtain the signal registeredmore » by the fluxgate and the peristaltic contractions could be calculated while the stomach was emptying. The solid food product developed results to work satisfactorily in magnetogastrography.« less

Effect of synthetic prostaglandin E1 analog on gastric emptying of meals in man.

PubMed

Moore, J G; Alazraki, N; Clay, G D

1986-01-01

Forty-five subjects with healed duodenal ulcer were administered either a placebo or a low-dose or high-dose regimen of misoprostol, a synthetic PGE1 analog, in a double-blind, random, parallel-group design to assess the effect of this prostaglandin compound on the gastric emptying of liquid-solid meals. A dual-radionuclide technique to measure liquid- and solid-phase gastric emptying rates of physiological meals by external gamma camera imaging was used. All subjects had a pretreatment control (baseline) evaluation, followed one week later by a treatment-influenced emptying study. The results demonstrated that misoprostol did not significantly alter gastric emptying of either liquids or solids; however, these results cannot be extrapolated to other prostaglandin compounds because of the diverse and sometimes paradoxical effects of different prostaglandins on gastric motility.

Does postprandial itopride intake affect the rate of gastric emptying? A crossover study using the continuous real time 13C breath test (BreathID system).

PubMed

Nonaka, Takashi; Kessoku, Takaomi; Ogawa, Yuji; Yanagisawa, Shogo; Shiba, Tadahiko; Sahaguchi, Takashi; Atsukawa, Kazuhiro; Takahashi, Hisao; Sekino, Yusuke; Iida, Hiroshi; Hosono, Kunihiro; Endo, Hiroki; Sakamoto, Yasunari; Koide, Tomoko; Takahashi, Hirokazu; Tokoro, Chikako; Abe, Yasunobu; Maeda, Shin; Nakajima, Atsushi; Inamori, Masahiko

2011-01-01

The aim of this study was to determine whether oral Itopride hydrochloride (itopride) intake might have any effect on the rate of gastric emptying, using a novel non-invasive technique for measuring the rate of gastric emptying, namely, the continuous real time 13C breath test (BreathID system: Exalenz Bioscience Ltd., Israel). Eight healthy male volunteers participated in this randomized, two-way crossover study. The subjects fasted overnight and were randomly assigned to receive 50mg itopride following a test meal (200 kcal per 200mL, containing 100mg 13C acetate), or the test meal alone. Under both conditions, gastric emptying was monitored for 4 hours after administration of the test meal by the 13C-acetic acid breath test performed continually using the BreathID system. Using Oridion Research Software (beta version), the time required for emptying of 50% of the labeled meal (T 1/2), the analog to the scintigraphy lag time for 10% emptying of the labeled meal (T lag), the gastric emptying coefficient (GEC), and the regression-estimated constants (beta and kappa) were calculated. The parameters measured under the two conditions were compared using the Wilcoxon's signed-rank test. No significant differences in the calculated parameters, namely, the T 1/2, T lag, GEC, beta or kappa, were observed between the two test conditions, namely, administration of a test meal+itopride and administration of the test meal alone. The present study revealed that postprandial itopride intake had no significant influence on the rate of gastric emptying. Recently, several studies have shown that itopride may be effective in the treatment of patients with functional dyspepsia. Our results suggest that the efficacy of itopride in patients with functional dyspepsia may be based on its effect of improving functions other than the rate of gastric emptying, such as the activities at neuronal sites, brain-gut correlation, visceral hypersensitivity, gastric accommodation and distension-induced adaptation.

A double-blind comparison of clebopride and placebo in dyspepsia secondary to delayed gastric emptying.

PubMed

Bavestrello, L; Caimi, L; Barbera, A

1985-01-01

Seventy-six patients suffering from dyspeptic symptoms secondary to roentgenologically demonstrated delayed gastric emptying were treated with clebopride (0.5 mg TID) or with placebo during a three-month double-blind trial. Clebopride was more effective (P less than or equal to 0.001) than placebo in reducing or relieving symptoms and roentgenological findings associated with delayed gastric emptying. No interactions of clebopride with concomitant drugs or coexisting disorders were observed, and the incidence of side effects was low. We conclude that clebopride will be beneficial in the management of patients with delayed gastric emptying.

Gastric emptying and intragastric distribution of lipids in man. A new scintigraphic method of study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jian, R.; Vigneron, N.; Najean, Y.

1982-08-01

We measured gastric emptying of fat and water from a solid-liquid meal in healthy volunteers using a tubeless scintigraphic method. /sup 75/Se glycerol triether, incorporated in butter, was the lipid-phase marker, and /sup 99m/Tcm, ingested with 250 ml water, the non-lipid phase marker. In seven of these subjects we also measured the gastric emptying of solids and liquids with /sup 99m/Tc bound to cooked egg whites as the solid-phase marker and /sup 111/In ingested with 250 ml water as the marker of the solid and aqueous phases. Emptying and intragastric repartition of each marker were measured by detection of radioactivitymore » changes over the abdominal area using a gamma-camera. The stability and the specificity of the labeling was checked for each marker. Mean gastric emptying rate (expressed as percentage ingested marker emptied per hr) of lipids (17.4 +/- 2.4) was much lower than that of the rest of the meal (34.2 +/- 1.8) and slightly, but significantly, lower than that of solids (22.8 +/- 1.8). An intragastric layering of fat above nonlipids was observed only after the first postprandial hour and remained moderate. Thus, lipids are emptied more slowly than any other component of an ordinary meal, and this is not due only to layering of fat above water.« less

Mucoadhesive microparticles for local treatment of gastrointestinal diseases.

PubMed

Preisig, Daniel; Roth, Roger; Tognola, Sandy; Varum, Felipe J O; Bravo, Roberto; Cetinkaya, Yalcin; Huwyler, Jörg; Puchkov, Maxim

2016-08-01

Mucoadhesive microparticles formulated in a capsule and delivered to the gastrointestinal tract might be useful for local drug delivery. However, swelling and agglomeration of hydrophilic polymers in the gastrointestinal milieu can have a negative influence on particle retention of mucoadhesive microparticles. In this work, we investigated the impact of dry-coating with nano-sized hydrophilic fumed silica on dispersibility and particle retention of mucoadhesive microparticles. As a model for local treatment of gastrointestinal diseases, antibiotic therapy of Clostridium difficile infections with metronidazole was selected. For particle preparation, we used a two-step fluidized-bed method based on drug loading of porous microcarriers and subsequent outer coating with the mucoadhesive polymer chitosan. The prepared microparticles were analysed for drug content, and further characterized by thermal analysis, X-ray diffraction, and scanning electron microscopy. The optimal molecular weight and content of chitosan were selected by measuring particle retention on porcine colonic mucosa under dynamic flow conditions. Mucoadhesive microparticles coated with 5% (weight of chitosan coating/total weight of particles) of low molecular weight chitosan showed good in vitro particle retention, and were used for the investigation of dispersibility enhancement. By increasing the amount of silica, the dissolution rate measured in the USPIV apparatus was increased, which was an indirect indication for improved dispersibility due to increased surface area. Importantly, mucoadhesion was not impaired up to a silica concentration of 5% (w/w). In summary, mucoadhesive microparticles with sustained-release characteristics over several hours were manufactured at pilot scale, and dry-coating with silica nanoparticles has shown to improve the dispersibility, which is essential for better particle distribution along the intestinal mucosa in humans. Therefore, this advanced drug delivery concept bears great potential, in particular for local treatment of gastrointestinal diseases. Copyright © 2016 Elsevier B.V. All rights reserved.

A diet and physical activity intervention for preventing weight retention among Taiwanese childbearing women: a randomised controlled trial.

PubMed

Huang, Tzu-ting; Yeh, Chieh-Ying; Tsai, Yc-Chen

2011-04-01

to examine the effect of individual counselling on diet and physical activity from pregnancy to six months post partum, or from birth to six months post partum, on weight retention among Taiwanese women. a randomised controlled trial assigned participants to two experimental groups [from pregnancy to six months post partum (EP) and from birth to six months post partum (EPP)] and one comparison group. a 3900-bed medical centre in northern Taiwan with around 3000 births annually. a sample of 189 women who had regular check-ups during pregnancy and gave birth at the medical centre. the comparison group received the routine outpatient department obstetric educational programme. The EP group attended regularly scheduled clinic visits with individualised dietary and physical activity education plans from 16 gestational weeks to six months post partum, and received on brochure. The EPP group received the same educational intervention as the EP group from 24-48 hours after birth to six months post partum. body weight, body mass index, health-promoting behaviour and psycho-social variables (self-efficacy, body image, depression and social support). average gestational weight gain was 14.02, 15.27 and 16.22 kg in the three EP, EPP and comparison groups respectively, and average weight retention at six months post partum was 2.34, 4.06 and 5.08 kg in the three groups, respectively. a diet and physical activity intervention from pregnancy is effective for reducing post-pregnancy weight retention. the findings of the present study should be taken into consideration when incorporating significant others and weight-loss maintenance strategies with interventions for a healthier family lifestyle. Copyright © 2009 Elsevier Ltd. All rights reserved.

Fine particle retention within stream storage areas at base flow and in response to a storm event

NASA Astrophysics Data System (ADS)

Drummond, J. D.; Larsen, L. G.; González-Pinzón, R.; Packman, A. I.; Harvey, J. W.

2017-07-01

Fine particles (1-100 µm), including particulate organic carbon (POC) and fine sediment, influence stream ecological functioning because they may contain or have a high affinity to sorb nitrogen and phosphorus. These particles are immobilized within stream storage areas, especially hyporheic sediments and benthic biofilms. However, fine particles are also known to remobilize under all flow conditions. This combination of downstream transport and transient retention, influenced by stream geomorphology, controls the distribution of residence times over which fine particles influence stream ecosystems. The main objective of this study was to quantify immobilization and remobilization rates of fine particles in a third-order sand-and-gravel bed stream (Difficult Run, Virginia, USA) within different geomorphic units of the stream (i.e., pool, lateral cavity, and thalweg). During our field injection experiment, a thunderstorm-driven spate allowed us to observe fine particle dynamics during both base flow and in response to increased flow. Solute and fine particles were measured within stream surface waters, pore waters, sediment cores, and biofilms on cobbles. Measurements were taken at four different subsurface locations with varying geomorphology and at multiple depths. Approximately 68% of injected fine particles were retained during base flow until the onset of the spate. Retention was evident even after the spate, with 15.4% of the fine particles deposited during base flow still retained within benthic biofilms on cobbles and 14.9% within hyporheic sediment after the spate. Thus, through the combination of short-term remobilization and long-term retention, fine particles can serve as sources of carbon and nutrients to downstream ecosystems over a range of time scales.

The potential of hybrid forward osmosis membrane bioreactor (FOMBR) processes in achieving high throughput treatment of municipal wastewater with enhanced phosphorus recovery.

PubMed

Qiu, Guanglei; Zhang, Sui; Srinivasa Raghavan, Divya Shankari; Das, Subhabrata; Ting, Yen-Peng

2016-11-15

Extensive research in recent years has explored numerous new features in the forward osmosis membrane bioreactor (FOMBR) process. However, there is an aspect, which is revolutionary but not yet been investigated. In FOMBR, FO membrane shows high rejection for a wide range of soluble contaminants. As a result, hydraulic retention time (HRT) does not correctly reflect the nominal retention of these dissolved contaminants in the bioreactor. This decoupling of contaminants retention time (CRT, i.e. the nominal retention of the dissolved contaminants) from HRT endows FOMBR a potential in significantly reducing the HRT for wastewater treatment. In this work, we report our results in this unexplored treatment potential. Using real municipal wastewater as feed, both a hybrid microfiltration-forward osmosis membrane bioreactor (MF-FOMBR) and a newly developed hybrid biofilm-forward osmosis membrane bioreactor (BF-FOMBR) achieved high removal of organic matter and nitrogen under HRT of down to 2.0 h, with significantly enhanced phosphorus recovery capacities. In the BF-FOMBR, the used of fixed bed biofilm not only obviated the need of additional solid/liquid separation (e.g. MF) to extract the side-stream for salt accumulation control and phosphorus recovery, but effectively quarantined the biomass from the FO membrane. The absence of MF in the side-stream further allowed suspended growth to be continuously removed from the system, which produced a selection pressure for the predominance of attached growth. As a result, a significant reduction in FO membrane fouling (by 24.7-54.5%) was achieved in the BF-FOMBR due to substantially reduced bacteria deposition and colonization. Copyright © 2016 Elsevier Ltd. All rights reserved.

Fine particle retention within stream storage areas at base flow and in response to a storm event

USGS Publications Warehouse

Drummond, J. D.; Larsen, L. G.; González-Pinzón, R.; Packman, A. I.; Harvey, Judson

2017-01-01

Fine particles (1–100 µm), including particulate organic carbon (POC) and fine sediment, influence stream ecological functioning because they may contain or have a high affinity to sorb nitrogen and phosphorus. These particles are immobilized within stream storage areas, especially hyporheic sediments and benthic biofilms. However, fine particles are also known to remobilize under all flow conditions. This combination of downstream transport and transient retention, influenced by stream geomorphology, controls the distribution of residence times over which fine particles influence stream ecosystems. The main objective of this study was to quantify immobilization and remobilization rates of fine particles in a third-order sand-and-gravel bed stream (Difficult Run, Virginia, USA) within different geomorphic units of the stream (i.e., pool, lateral cavity, and thalweg). During our field injection experiment, a thunderstorm-driven spate allowed us to observe fine particle dynamics during both base flow and in response to increased flow. Solute and fine particles were measured within stream surface waters, pore waters, sediment cores, and biofilms on cobbles. Measurements were taken at four different subsurface locations with varying geomorphology and at multiple depths. Approximately 68% of injected fine particles were retained during base flow until the onset of the spate. Retention was evident even after the spate, with 15.4% of the fine particles deposited during base flow still retained within benthic biofilms on cobbles and 14.9% within hyporheic sediment after the spate. Thus, through the combination of short-term remobilization and long-term retention, fine particles can serve as sources of carbon and nutrients to downstream ecosystems over a range of time scales.

Empty Tissue Boxes: Considering Poverty in Diversity Discourse

ERIC Educational Resources Information Center

Cuthrell, Kristen; Ledford, Carolyn; Stapleton, Joy

2007-01-01

A preservice teacher doing her internship overhears some of her students asking a classmate why he regularly takes home empty tissue boxes. The boy replies that he builds cities and bridges with his empty boxes. His classmates then ask why he does not just build a city with Legos or building blocks. The preservice teacher listens intently as the…

Affordable Housing and the Empty Nester Boom.

ERIC Educational Resources Information Center

Hare, Patrick H.

One of the best ways to produce affordable housing is to address the needs of a group that has too much housing. A baby boom generation generates an empty nester boom. An empty nester boom means dramatic underutilization of the housing stock. If a small percentage of homeowners were to install an accessory apartment, they would have a significant…

21 CFR 864.9100 - Empty container for the collection and processing of blood and blood components.

Code of Federal Regulations, 2010 CFR

2010-04-01

... of blood and blood components. 864.9100 Section 864.9100 Food and Drugs FOOD AND DRUG ADMINISTRATION... Used In Establishments That Manufacture Blood and Blood Products § 864.9100 Empty container for the collection and processing of blood and blood components. (a) Identification. An empty container for the...

21 CFR 864.9100 - Empty container for the collection and processing of blood and blood components.

Code of Federal Regulations, 2012 CFR

2012-04-01

... of blood and blood components. 864.9100 Section 864.9100 Food and Drugs FOOD AND DRUG ADMINISTRATION... Used In Establishments That Manufacture Blood and Blood Products § 864.9100 Empty container for the collection and processing of blood and blood components. (a) Identification. An empty container for the...

21 CFR 864.9100 - Empty container for the collection and processing of blood and blood components.

Code of Federal Regulations, 2011 CFR

2011-04-01

... of blood and blood components. 864.9100 Section 864.9100 Food and Drugs FOOD AND DRUG ADMINISTRATION... Used In Establishments That Manufacture Blood and Blood Products § 864.9100 Empty container for the collection and processing of blood and blood components. (a) Identification. An empty container for the...

21 CFR 864.9100 - Empty container for the collection and processing of blood and blood components.

Code of Federal Regulations, 2014 CFR

2014-04-01

... of blood and blood components. 864.9100 Section 864.9100 Food and Drugs FOOD AND DRUG ADMINISTRATION... Used In Establishments That Manufacture Blood and Blood Products § 864.9100 Empty container for the collection and processing of blood and blood components. (a) Identification. An empty container for the...

21 CFR 864.9100 - Empty container for the collection and processing of blood and blood components.

Code of Federal Regulations, 2013 CFR

2013-04-01

... of blood and blood components. 864.9100 Section 864.9100 Food and Drugs FOOD AND DRUG ADMINISTRATION... Used In Establishments That Manufacture Blood and Blood Products § 864.9100 Empty container for the collection and processing of blood and blood components. (a) Identification. An empty container for the...

Impaired Performance of Right-Brain-Damaged Patients on a Sentence Anagram Task

ERIC Educational Resources Information Center

Murasugi, K.; Schneiderman, E.

2005-01-01

A sentence anagram task was used to examine the right cerebral hemispheres's role in core grammatical functioning at the syntactic level. The test consisted of two subsets of stimuli involving empty categories: (a) those that required the empty category to be filled, and (b) those that allowed the category to remain empty. Three hypotheses were…

Energy efficiency of growing ram lambs fed concentrate-based diets with different roughage sources.

PubMed

Galvani, D B; Pires, A V; Susin, I; Gouvêa, V N; Berndt, A; Chagas, L J; Dórea, J R R; Abdalla, A L; Tedeschi, L O

2014-01-01

Poor-quality roughages are widely used as fiber sources in concentrate-based diets for ruminants. Because roughage quality is associated with the efficiency of energy use in forage-based diets, the objective of this study was to determine whether differing the roughage source in concentrate-based diets could change the energy requirements of growing lambs. Eighty-four 1/2 Dorper × 1/2 Santa Inês ram lambs (18.0 ± 3.3 kg BW) were individually penned and divided into 2 groups according to primary source of dietary roughage: low-quality roughage (LQR; sugarcane bagasse) or medium-quality roughage (MQR; coastcross hay). Diets were formulated to be isonitrogenous (2.6% N) and to meet 20% of physically effective NDF. After a 10-d ad libitum adaptation period, 7 lambs from each group were randomly selected and slaughtered (baseline). Twenty-one lambs in each diet group were fed ad libitum and slaughtered at 25, 35, or 45 kg BW. The remaining 28 lambs (14 from each diet group) were submitted to 1 of 2 levels of feed restriction: 70% or 50% of the ad libitum intake. Retentions of body fat, N, and energy were determined. Additionally, 6 ram lambs (44.3 ± 5.6 kg BW) were kept in metabolic cages and used in a 6 × 6 Latin square experiment designed to establish the ME content of the 2 diets at the 3 levels of DM intake. There was no effect of intake level on diet ME content, but it was greater in the diet with LQR than in the diet with MQR (3.18 vs. 2.94 Mcal/kg, respectively; P < 0.01). Lambs fed the diet with LQR had greater body fat (g/kg of empty BW) and energy concentrations (kcal/kg of empty BW) because of a larger visceral fat deposition (P < 0.05). Using a low-quality roughage as a primary source of forage in a concentrate-based diet for growing lambs did not change NEm and the efficiency of ME use for maintenance, which averaged 71.6 kcal/kg(0.75) of shrunk BW and 0.63, respectively. On the other hand, the greater nonfibrous carbohydrate content of the diet with LQR resulted in a 17% better efficiency of ME use for gain (P < 0.01), which was associated with a greater partial efficiency of energy retention as fat (P < 0.01). This increased nutritional efficiency, however, should be viewed with caution because it is related to visceral fat deposition, a nonedible tissue.

Mineral requirements for growth and maintenance of F1 Boer × Saanen male kids.

PubMed

Teixeira, I A M A; Härter, C J; Pereira Filho, J M; Sobrinho, A G da Silva; Resende, K T

2015-05-01

The objective of this study was to determine the net requirements of minerals for the growth and maintenance of intact male F1 Boer × Saanen goat kids in the initial phase of growth. The following 2 experiments were performed: Exp. 1 was performed to determine the net growth requirements for Ca, P, Mg, Na, and K by F1 Boer × Saanen goat kids from 5 to 25 kg of BW and Exp. 2 was performed to determine the maintenance requirements of F1 Boer × Saanen goats from 15 to 25 kg BW. In Exp. 1, 32 intact male goat kids were distributed in a completely randomized design and mineral body composition was fit to an allometric equation in the form of a nonlinear model. To determine the mineral requirements for maintenance in Exp. 2, 21 intact male goat kids were distributed in a randomized block design, where the goat kids were subjected to 3 levels of feed restriction (0, 30, and 60% feed restriction). At the onset of Exp. 2, 7 goat kids were harvested and used to estimate the initial body composition (15 kg BW). Initial body composition was used to calculate the retention of minerals. The maintenance requirements were estimated by regressions obtained from the retention of minerals in the empty body and the intake of the mineral. The concentration of Ca, P, Na, and K in the empty BW decreased by 11, 13, 26, and 23% with the increase in BW from 5 to 25 kg (P < 0.01). As a consequence, our results showed that net requirements of Ca, P, Mg, Na, and K for weight gain decreased by 27.5, 27.8, 4.25, 43.2, and 39.7%, respectively, with the increase in BW from 5 to 25 kg (P < 0.01). The net requirements (g/kg of ADG) decreased from 9.7 to 7.0 for Ca, 6.5 to 4.7 for P, 0.38 to 0.36 for Mg, 0.88 to 0.50 for Na, and 1.9 to 1.2 for K when BW increased from 5 to 25 kg. The daily net requirements for maintenance per kilogram of BW were 38 mg of Ca, 42 mg of P, 1.6 mg of Mg, 5.0 mg of Na, and 19 mg of K. These results for the nutritional requirements of minerals may help to formulate more balanced diets for F1 Boer × Saanen goat kids in the initial growth phase.

Relationships of the early insulin secretory response and oral disposition index with gastric emptying in subjects with normal glucose tolerance.

PubMed

Marathe, Chinmay S; Rayner, Christopher K; Lange, Kylie; Bound, Michelle; Wishart, Judith; Jones, Karen L; Kahn, Steven E; Horowitz, Michael

2017-02-01

The oral disposition index, the product of the early insulin secretory response during an oral glucose tolerance test and insulin sensitivity, is used widely for both the prediction of, and evaluation of the response to interventions, in type 2 diabetes. Gastric emptying, which determines small intestinal exposure of nutrients, modulates postprandial glycemia. The aim of this study was to determine whether the insulin secretory response and the disposition index (DI) related to gastric emptying in subjects with normal glucose tolerance. Thirty-nine subjects consumed a 350 mL drink containing 75 g glucose labeled with 99m Tc-sulfur colloid. Gastric emptying (by scintigraphy), blood glucose (G) and plasma insulin (I) were measured between t  = 0-120 min. The rate of gastric emptying was derived from the time taken for 50% emptying ( T 50 ) and expressed as kcal/min. The early insulin secretory response was estimated by the ratio of the change in insulin (∆I 0-30 ) to that of glucose at 30 min (∆G 0-30 ) represented as ∆I 0-30 /∆G 0-30 Insulin sensitivity was estimated as 1/fasting insulin and the DI was then calculated as ∆I 0-30 /∆G 0-30  × 1/fasting insulin. There was a direct relationship between ∆G 0-30 and gastric emptying ( r  = 0.47, P  = 0.003). While there was no association of either ∆I 0-30 ( r  = -0.16, P  = 0.34) or fasting insulin ( r  = 0.21, P  = 0.20), there were inverse relationships between the early insulin secretory response ( r  = -0.45, P  = 0.004) and the DI ( r  = -0.33, P  = 0.041), with gastric emptying. We conclude that gastric emptying is associated with both insulin secretion and the disposition index in subjects with normal glucose tolerance, such that when gastric emptying is relatively more rapid, both the early insulin secretory response and the disposition index are less. These findings should be interpreted as "hypothesis generating" and provide the rationale for longitudinal studies to examine the impact of baseline rate of gastric emptying on the prospective risk of type 2 diabetes. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

Inhibitory effect of ramosetron on corticotropin releasing factor- and soybean oil-induced delays in gastric emptying in rats.

PubMed

Hirata, Takuya; Keto, Yoshihiro; Yamano, Mayumi; Yokoyama, Toshihide; Sengoku, Takanori; Seki, Nobuo

2012-09-01

Symptoms of functional dyspepsia (FD) are highly prevalent in patients with irritable bowel syndrome (IBS). However, the effects of therapeutic agents for IBS on the pathophysiology of FD are unclear. In this study, therefore, we examined the effects of ramosetron, a serotonin 5-HT(3) receptor antagonist, on corticotropin releasing factor (CRF)- and soybean oil-induced delays in gastric emptying of rats, in comparison with anti-diarrheal agent and spasmolytics. The involvement of 5-HT and the 5-HT(3) receptor in delayed gastric emptying was also evaluated. Corticotropin releasing factor was administered intravenously to rats 10min before oral administration of 0.05% phenol red solution, and the amount remaining in the stomach was measured after 30min. Soybean oil was administered orally with glass beads, and the number of residual beads in the stomach was counted 1h later. Both CRF and soybean oil inhibited gastric emptying dose-dependently. Ramosetron and itopride, a gastro-prokinetic agent, significantly reduced both CRF- and soybean oil-induced delays in gastric emptying, while an anti-diarrheal agent and spasmolytics aggravated them. Pretreatment with p-chlorophenylalanine for 2days to reduced the synthesis of endogenous 5-HT diminished the effects of both CRF and soybean oil on gastric emptying. A 5-HT(3) receptor agonist m-chlorophenylbiguanide suppressed gastric emptying of both phenol red and glass beads, and those effects were reversed by ramosetron. These results suggest that CRF and soybean oil suppress gastric emptying in rats by activating 5-HT(3) receptors, and that by antagonizing these receptors, ramosetron may ameliorate symptoms of FD in clinical settings. © 2012 Journal of Gastroenterology and Hepatology Foundation and Blackwell Publishing Asia Pty Ltd.

A central site of action for benzamide facilitation of gastric emptying.

PubMed

Costall, B; Gunning, S J; Naylor, R J; Simpson, K H

1983-07-22

Gastric emptying of the fed guinea-pig was measured using a non-invasive X-ray fluoroscopic technique to determine passage from the stomach of polystyrene-coated barium sulphate spheroids. Peripherally administered metoclopramide (0.1-10 mg/kg i.p.), clebopride (1-10 mg/kg i.p.), (-)-sulpiride (40 mg/kg i.p.), haloperidol (1 mg/kg i.p.) and domperidone (1-10 mg/kg i.p.) failed to modify gastric emptying. Stress inhibited emptying, and this was considered to explain the effects of eserine and high dose metoclopramide. Gastric emptying was decreased by peripherally administered atropine (0.5 mg/kg i.p.) and apomorphine (0.1-0.5 mg/kg s.c.); the apomorphine response was antagonised by pretreatment with haloperidol, domperidone, (-)-sulpiride, metoclopramide and clebopride but not by prazosin + propranolol. Gastric emptying was facilitated by intracerebroventricular (i.c.v.) administrations of metoclopramide and clebopride (40, 100 and 200 micrograms) but not by i.c.v. domperidone, haloperidol, fluphenazine or (-)-sulpiride (100, 200 micrograms) and was inhibited by i.c.v. apomorphine (100, 200 micrograms); the response to i.c.v. apomorphine was antagonised by i.c.v. pretreatments with haloperidol, domperidone, (-)-sulpiride, metoclopramide and clebopride (40-50 micrograms). Facilitation of emptying by i.c.v. metoclopramide was prevented by peripheral pretreatment with atropine (0.5 mg/kg i.p.). It is concluded that the actions of apomorphine and metoclopramide/clebopride to respectively inhibit and facilitate gastric emptying may be mediated, at least in part, via central mechanisms. Whilst apomorphine's action may be mediated via dopamine receptor mechanisms, metoclopramide and clebopride act at additional unspecified sites, metoclopramide's action being expressed via cholinergic mechanisms.

Preload of slowly digestible carbohydrate microspheres decreases gastric emptying rate of subsequent meal in humans.

PubMed

Cisse, Fatimata; Pletsch, Elizabeth A; Erickson, Daniel P; Chegeni, Mohammad; Hayes, Anna M R; Hamaker, Bruce R

2017-09-01

Gastric emptying rate influences how fast the nutrients of a meal are delivered to the body, and when slow, it moderates glycemic response and may impact satiety. Carbohydrates are one of the macronutrients that trigger the ileal brake, and we hypothesized that slowly digestible carbohydrate (SDC) administered in a premeal load would delay gastric emptying. A crossover design study was conducted with 10 healthy adults using fabricated SDC-microspheres (cooked) that were given 20 minutes before a non-nutritive viscous paste meal. There were 4 treatment arms, each separated by a 1-week washout period, consisting of (1) the paste alone, (2) a rapidly digesting maltodextrin (Polycose) preload followed by the paste 20 minutes later, (3) an SDC-microsphere preload followed by the paste, and (4) a comparably slower SDC-microsphere preload followed by the paste. A 13 C-labeled octanoic acid breath test method was used to measure gastric emptying, with the label incorporated into the non-nutritive paste. The microspheres were less than 1 mm in diameter (a size that does not require breakdown in the stomach before emptying) and, after cooking, were of the same density value. Compared with the paste alone, both of the SDC-microsphere preloads (slow and comparably slower digesting) decreased gastric emptying rate of the paste, with the latter having the most effect (half-emptying times of 1.7, 2.3, and 2.8 hours, respectively [each different at P<.05]). In conclusion, SDCs decreased gastric emptying rate, and this was suggested to be due to a triggering of the ileal brake. Copyright © 2017 Elsevier Inc. All rights reserved.

Exercise and training effects on gastric emptying of carbohydrate beverages.

PubMed

Rehrer, N J; Beckers, E; Brouns, F; Hoor ten, F; Saris, W H

1989-10-01

Carbohydrate containing drinks are commonly consumed as an ergogenic aid during endurance sports activities. The efficacy of a given drink is limited by the rate of absorption, which is in turn limited by gastric emptying. A myriad of factors influence gastric emptying. The influence of several of these factors (training status, exercise intensity, and carbohydrate composition) was investigated by repeated experiments using a nasogastric tube and a modification of the technique of George. A group of well-trained bicyclists and a group of untrained subjects performed similar experiments. Three different carbohydrate containing drinks (15 g.100 ml-1 glucose (G), 15 g.100 ml-1 maltodextrin plus 3 g.100 ml-1 fructose (MD), 7 g.100 ml-1 sucrose (I] and artificially sweetened water were compared during rest and 50 and 70% Wmax bicycling. Experimental design was crossover. There was a trend for the carbohydrate drinks to empty initially more slowly under the influence of exercise. Differences in drink volume remaining in the stomach were significant (P less than 0.05), with I at 10 min (70%, mean = 48.9%; rest, mean = 30.5%) and at 20 min (70%, mean = 28.9%; rest, mean = 23.8%) and with MD at 10 min (70%, mean = 71.1%; rest, mean = 55.9%). A similar trend was also seen with 50% Wmax exercise; however, this trend was only significant with MD at 10 min (50%, mean = 72.1%; rest, mean = 55.9%). Drink composition was a much stronger inhibitor of gastric emptying. However, all drinks emptied exponentially with fast-phase initial emptying rates. No differences in gastric emptying or secretion were observed between trained and untrained subjects.

Influence of 5 Different Caging Types and the Use of Cage-Changing Stations on Mouse Allergen Exposure

PubMed Central

Feistenauer, Susan; Sander, Ingrid; Schmidt, Jörg; Zahradnik, Eva; Raulf, Monika; Brielmeier, Markus

2014-01-01

Animal allergens constitute a serious health risk in laboratory animal facilities. To assess possibilities for allergen reduction by technical and organizational measures, we studied personnel exposure to mouse urinary aeroallergens in an animal facility with a holding capacity of 30,000 cages. Short-term (2 h) and intermediate-term (12 h) stationary samples (n = 107) and short-term (2 h) personnel samples (n = 119) were collected on polytetrafluorethylene filters by using air pumps. Long-term (14 d) stationary dust samples containing airborne allergens (n = 165) were collected with electrostatic dust fall collectors (EDC). Mouse allergens were quantified by ELISA. Personnel samples were collected during bedding disposal and refilling of clean cages as well as during cage changing with and without use of cage-changing station. Animal rooms were equipped with either open cages, cages with a soft filter top, cages with a rigid filter top (static microisolation caging), or with individually ventilated cages (IVC) with either a sealed or nonsealed lid, each in positive- or negative-pressure mode. Highest personnel allergen exposure was detected during cage change and emptying of soiled cages. Allergen concentrations were lowest in rooms with sealed IVC under positive or negative pressure, with unsealed IVC under negative pressure, and with static microisolation caging. The use of cage-changing stations and a vacuum bedding-disposal system reduced median personnel exposures 14- to 25-fold, respectively. Using sealed IVC and changing stations minimized allergen exposure, indicating that state-of-the-art equipment reduces exposure to mouse allergens and decreases health risks among animal facility personnel. PMID:25199090

Optimization of arsenic removal water treatment system through characterization of terminal electron accepting processes.

PubMed

Upadhyaya, Giridhar; Clancy, Tara M; Brown, Jess; Hayes, Kim F; Raskin, Lutgarde

2012-11-06

Terminal electron accepting process (TEAP) zones developed when a simulated groundwater containing dissolved oxygen (DO), nitrate, arsenate, and sulfate was treated in a fixed-bed bioreactor system consisting of two reactors (reactors A and B) in series. When the reactors were operated with an empty bed contact time (EBCT) of 20 min each, DO-, nitrate-, sulfate-, and arsenate-reducing TEAP zones were located within reactor A. As a consequence, sulfate reduction and subsequent arsenic removal through arsenic sulfide precipitation and/or arsenic adsorption on or coprecipitation with iron sulfides occurred in reactor A. This resulted in the removal of arsenic-laden solids during backwashing of reactor A. To minimize this by shifting the sulfate-reducing zone to reactor B, the EBCT of reactor A was sequentially lowered from 20 min to 15, 10, and 7 min. While 50 mg/L (0.81 mM) nitrate was completely removed at all EBCTs, more than 90% of 300 μg/L (4 μM) arsenic was removed with the total EBCT as low as 27 min. Sulfate- and arsenate-reducing bacteria were identified throughout the system through clone libraries and quantitative PCR targeting the 16S rRNA, dissimilatory (bi)sulfite reductase (dsrAB), and dissimilatory arsenate reductase (arrA) genes. Results of reverse transcriptase (RT) qPCR of partial dsrAB (i.e., dsrA) and arrA transcripts corresponded with system performance. The RT qPCR results indicated colocation of sulfate- and arsenate-reducing activities, in the presence of iron(II), suggesting their importance in arsenic removal.

Gastric emptying of enteric-coated tablets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, H.M.; Chernish, S.M.; Rosenek, B.D.

1984-03-01

To evaluate the gastric emptying time of pharmaceutical dosage forms in a clinical setting, a relatively simple dual-radionuclide technique was developed. Placebo tablets of six different combinations of shape and size were labeled with indium-111 DTPA and enteric coated. Six volunteers participated in a single-blind and crossover study. Tablets were given in the morning of a fasting stomach with 6 oz of water containing /sup 99m/Tc pertechnetate and continuously observed with a gamma camera. A scintigraph was obtained each minute. The results suggested that the size, shape, or volume of the tablet used in this study had no significant effectmore » in the rate of gastric emptying. The tablets emptied erratically and unpredictably, depending upon their time of arrival in the stomach in relation to the occurrence of interdigestive myoelectric contractions. The method described is a relatively simple and accurate technique to allow one to follow the gastric emptying of tablets.« less

Empty tracks optimization based on Z-Map model

NASA Astrophysics Data System (ADS)

Liu, Le; Yan, Guangrong; Wang, Zaijun; Zang, Genao

2017-12-01

For parts with many features, there are more empty tracks during machining. If these tracks are not optimized, the machining efficiency will be seriously affected. In this paper, the characteristics of the empty tracks are studied in detail. Combining with the existing optimization algorithm, a new tracks optimization method based on Z-Map model is proposed. In this method, the tool tracks are divided into the unit processing section, and then the Z-Map model simulation technique is used to analyze the order constraint between the unit segments. The empty stroke optimization problem is transformed into the TSP with sequential constraints, and then through the genetic algorithm solves the established TSP problem. This kind of optimization method can not only optimize the simple structural parts, but also optimize the complex structural parts, so as to effectively plan the empty tracks and greatly improve the processing efficiency.

Geomorphic Effects of Boulder Placement on Gravel Capture and Retention in a Regulated Reach of the North Umpqua River, OR.

NASA Astrophysics Data System (ADS)

Stallman, J.; Braudrick, C.; Pedersen, D.; Cui, Y.; Sklar, L.; Dietrich, B.; Real de Asua, R.

2004-12-01

Hydroelectric projects in the mountainous western Cascades often occur in steep, confined channels where salmonid spawning habitat is limited to gravel deposits forced by planform curvature, channel width changes, and flow separation associated with large bedrock and boulder obstructions. The paucity of gravel deposition in steepland channels may be exacerbated in regulated rivers where sediment trapping by impoundments reduces coarse sediment supply to downstream reaches. Placing boulders to capture and retain gravel may be an effective approach to enhancing spawning habitat in these settings. To better understand the potential use of boulders as a tool for enhancing spawning habitat, three experimental designs were tested in a 0.6-mile bypass reach of the North Umpqua River, OR. The bedrock-confined study reach has an average slope of 0.013 and plane-bed morphology with coarse cobble substrate, abundant marginal boulders, and small associated patches of sand and gravel. Experiments involved (1) placement of boulder clusters, (2) gravel augmentation and placement of boulder clusters, and (3) gravel augmentation alone. Boulder clusters were designed to promote scour and deposition during floods with a 5-10 year recurrence interval. Boulders were typically placed obliquely upstream at locations where existing hydraulics favored gravel deposition. Monitoring from 2002 to 2004 occurred prior to implementation, immediately following implementation, and following winter high flows. Sites were monitored using high-density topographic surveys, low-altitude aerial photography, facies mapping, pebble counts, scour cores and chains, and marked rocks. Stage heights were monitored using pressure transducers at the upstream and downstream ends of the study reach, and flood recurrence interval was assessed using a nearby USGS gauge. The arrangement of boulder clusters was modified after the first year of monitoring to improve gravel capture and retention. Peak flow during the two-year monitoring period had a recurrence interval of less than 1.5 years. Flows were insufficient to mobilize the bed as a whole, but did adjust bed surface texture and topography adjacent to boulder accumulations. Select sites captured and retained modest amounts of gravel even at the relatively low peaks experienced during 2003 and 2004. The effects of increasing coarse sediment supply will be tested in 2005 through the introduction of a large gravel pulse at the upstream end of the study reach.

Differing Interpretations of Empty Categories in English and Japanese VP Ellipsis Contexts

ERIC Educational Resources Information Center

Matsuo, Ayumi

2007-01-01

This article describes how English and Japanese children interpret empty categories in Verb Phrase Ellipsis contexts as in (1):(1) The penguin [sat on his chair] and the robot did [delta], too. To obtain an adultlike interpretation of (1), English children have to do two things. First, they need to find a suitable antecedent for the empty verb…

Method for the quantitation of gastric emptying time of gel test meals.

PubMed

Russell, J; Bass, P

1984-09-01

Isotopic markers were developed to allow measurement of the gastric emptying times of homogeneous and nonhomogeneous gel meals. Meals containing the dietary fibers psyllium and guar gum presented as homogeneous, viscous gels while meals containing the synthetic polymer polycarbophil presented as discrete gel particle-water mixtures. Fiber meals were labeled differently than polycarbophil meals. Fiber meals were labeled with 51Cr-CM-Sephadex. The marker was uniformly suspended in meals containing at least 1% guar or 2% psyllium. In contrast, polycarbophil particles were labeled by hydrating the dried granules with saline in which Na2(51)CrO4 had been dissolved. Use of the markers to measure gastric emptying was demonstrated in dogs fitted with duodenal cannulas. Half of the fiber meals emptied from the stomach in about 40 min without significant dilution by secretions. In contrast, only 8% of the polycarbophil particles emptied by 90 min. Particle-specific labeling of polycarbophil was important because the meal effluent was diluted extensively by secretions. We conclude that 51Cr-CM-Sephadex and soluble Cr-51 may be used as meal markers for estimation of the gastric emptying times of certain homogeneous and nonhomogeneous gel-type meals, respectively.

Gallbladder emptying to endogenous and exogenous stimulation in chronic pancreatitis patients.

PubMed

Meguro, T; Shimosegawa, T; Kashimura, J; Kikuchi, Y; Koizumi, M; Toyota, T

1994-02-01

The present study was designed to analyze the underlying mechanism of gallbladder motor disturbance in chronic pancreatitis patients. Gallbladder emptying to endogenous (oral test meal, Daiyan 13 g) and exogenous stimulation (iv cerulein, 30 ng/kg for 5 min) was examined by real-time ultrasonography in 12 patients with chronic pancreatitis and 10 normal subjects (controls). Plasma cholecystokinin levels during the endogenous stimulation were measured by bioassay. In chronic pancreatitis patients compared with controls, the fasting gallbladder volume was significantly increased (29.5 +/- 2.2 vs. 21.5 +/- 2.8 ml), whereas the gallbladder emptying (percent change of the basal volume) to oral test meal was significantly decreased. Neither cholecystokinin secretion induced by the test meal, nor the gallbladder emptying response to intravenous cerulein, differed significantly between the two groups. However, when chronic pancreatitis patients were divided according to pathogenesis, it became clear that gallbladder emptying to intravenous cerulein was significantly greater in patients with alcoholic chronic pancreatitis than in patients with idiopathic pancreatitis. Gallbladder emptying during the intestinal phase is generally reduced in patients with chronic pancreatitis, but gallbladder responsiveness to exogenous stimulation might be heterogeneous according to the pathogenesis.

PILOT PEAT-BED TREATMENT SYSTEM FOR NPDES OUTFALL H-12

DOE Office of Scientific and Technical Information (OSTI.GOV)

Halverson, N; Ralph Nichols, R; Topher Berry, T

2007-10-22

A National Pollutant Discharge Elimination System (NPDES) Permit was issued to the Savannah River Site (SRS) by the South Carolina Department of Health and Environmental Control (SCDHEC) and became effective on December 1, 2003. The new permit contained revised limits for copper and zinc derived by adjusting the South Carolina aquatic life water quality standards in accordance with dissolved metals criteria. The new copper and zinc limits are very low and may not be met consistently at Outfall H-12. The outfall has periodically exceeded the new 6 {micro}g/l (0.006 mg/L) monthly average limit and the 8 {micro}g/l (0.008 mg/L) maximummore » limit for copper and recently has begun exceeding the 100 {micro}g/l (0.100 mg/L) limit for zinc. The compliance date for Outfall H-12 is November 1, 2008. A study was conducted on this outfall and other outfalls to evaluate possible alternatives for meeting the new permit limits (Shipman and Bugher 2004). The study team recommended construction of a peat bed for treatment of the Outfall H-12 effluent. This recommendation was repeated by a second alternatives study team in 2007 (WSRC 2007). A bench-scale laboratory study demonstrated the feasibility of peat-bed treatment for Outfall H-12 effluent, with the peat demonstrating excellent removal of copper (Nelson and Specht 2005). An additional study was performed in 2006 and early 2007 using vertical-flow peat columns to investigate the influence of water retention time (contact time) on the removal of copper and zinc from the water (Nelson 2007c). Analytical results indicated that copper removal was very high at each of the three retention times tested, ranging from 99.6% removal at five and three hours to 98.8% removal at one hour. Effluent copper levels from these studies were much lower than the new compliance limit for the outfall. Most divalent metals, including zinc, were removed to below their normal reporting detection limit. The H-Area Material Disposition organization requested a larger-scale study to investigate key design and operation parameters/issues, such as the possibility of rapid plugging of the piping or clogging of the peat bed, the effectiveness of the treatment, hydraulic conductivity, etc. The resulting pilot-scale facility was constructed adjacent to Outfall H-12 with SCDHEC approval (Mullinax 2007). The pilot-scale study was performed by the Savannah River National Laboratory's (SRNL) Environmental Science and Biotechnology Directorate personnel. Since the construction and operation of the pilot-scale peat bed facility, however, a new strategy for achieving compliance of Outfall H-12 effluent with the new permit limits has been selected. This new strategy incorporates a variety of efforts including source reduction, recalculation of limits using an aquatic species that is indigenous to the area instead of a standard species, and dissolved organic carbon addition to reduce copper toxicity. This report documents the construction and operation of the pilot-scale treatment system, the results obtained, and recommendations on the usefulness of this technology for Outfall H-12 or other outfalls at SRS.« less

Traditional Malian Solid Foods Made from Sorghum and Millet Have Markedly Slower Gastric Emptying than Rice, Potato, or Pasta.

PubMed

Cisse, Fatimata; Erickson, Daniel P; Hayes, Anna M R; Opekun, Antone R; Nichols, Buford L; Hamaker, Bruce R

2018-01-26

From anecdotal evidence that traditional African sorghum and millet foods are filling and provide sustained energy, we hypothesized that gastric emptying rates of sorghum and millet foods are slow, particularly compared to non-traditional starchy foods (white rice, potato, wheat pasta). A human trial to study gastric emptying of staple foods eaten in Bamako, Mali was conducted using a carbon-13 ( 13 C)-labelled octanoic acid breath test for gastric emptying, and subjective pre-test and satiety response questionnaires. Fourteen healthy volunteers in Bamako participated in a crossover design to test eight starchy staples. A second validation study was done one year later in Bamako with six volunteers to correct for endogenous 13 C differences in the starches from different sources. In both trials, traditional sorghum and millet foods (thick porridges and millet couscous) had gastric half-emptying times about twice as long as rice, potato, or pasta ( p < 0.0001). There were only minor changes due to the 13 C correction. Pre-test assessment of millet couscous and rice ranked them as more filling and aligned well with postprandial hunger rankings, suggesting that a preconceived idea of rice being highly satiating may have influenced subjective satiety scoring. Traditional African sorghum and millet foods, whether viscous in the form of a thick porridge or as non-viscous couscous, had distinctly slow gastric emptying, in contrast to the faster emptying of non-traditional starchy foods, which are popular among West African urban consumers.

Traditional Malian Solid Foods Made from Sorghum and Millet Have Markedly Slower Gastric Emptying than Rice, Potato, or Pasta

PubMed Central

Cisse, Fatimata; Erickson, Daniel P.; Hayes, Anna M. R.; Opekun, Antone R.; Nichols, Buford L.; Hamaker, Bruce R.

2018-01-01

From anecdotal evidence that traditional African sorghum and millet foods are filling and provide sustained energy, we hypothesized that gastric emptying rates of sorghum and millet foods are slow, particularly compared to non-traditional starchy foods (white rice, potato, wheat pasta). A human trial to study gastric emptying of staple foods eaten in Bamako, Mali was conducted using a carbon-13 (13C)-labelled octanoic acid breath test for gastric emptying, and subjective pre-test and satiety response questionnaires. Fourteen healthy volunteers in Bamako participated in a crossover design to test eight starchy staples. A second validation study was done one year later in Bamako with six volunteers to correct for endogenous 13C differences in the starches from different sources. In both trials, traditional sorghum and millet foods (thick porridges and millet couscous) had gastric half-emptying times about twice as long as rice, potato, or pasta (p < 0.0001). There were only minor changes due to the 13C correction. Pre-test assessment of millet couscous and rice ranked them as more filling and aligned well with postprandial hunger rankings, suggesting that a preconceived idea of rice being highly satiating may have influenced subjective satiety scoring. Traditional African sorghum and millet foods, whether viscous in the form of a thick porridge or as non-viscous couscous, had distinctly slow gastric emptying, in contrast to the faster emptying of non-traditional starchy foods, which are popular among West African urban consumers. PMID:29373493

Gastric emptying 16 to 26 years after treatment of infantile hypertrophic pyloric stenosis.

PubMed

Lüdtke, F E; Bertus, M; Voth, E; Michalski, S; Lepsien, G

1994-04-01

Long-term follow-up was performed 16 to 26 years after conservative (group I, n = 18) and operative (group II, n = 38) treatment of 56 patients who had infantile hypertrophic pyloric stenosis (IHPS). The study encompassed the scintigraphic determination of gastric emptying rates for solids and liquids, an interview to obtain medical history and ascertain whether a current disorder of the upper gastrointestinal tract was present, and a clinical examination. Gastric emptying rates were measured on two different days for solids and liquids. The standard solid meal consisted of two scrambled eggs, two slices of toast, and 20 g of margarine. The gastric emptying rate for liquids was measured using 300 mL of apple juice. The scrambled eggs and apple juice were each marked with 2.2 MBq technetium 99m-sulphur-colloid. Two control collectives were used in this study; one group (physicians) served to create a reference curve for gastric emptying, and the other group, with the same age and gender distributions as those of the patients, served to evaluate the frequency of gastrointestinal complaints, by means of a questionnaire. There was no significant rate difference for gastric emptying between the patients treated conservatively or surgically and the controls. No association could be construed between the frequency of gastrointestinal symptoms or disorders and the gastric emptying rates for solids and liquids. The results presented here substantiate that clinically relevant disturbances of stomach motility after IHPS appear to be rare.

Brown rice compared to white rice slows gastric emptying in humans.

PubMed

Pletsch, Elizabeth A; Hamaker, Bruce R

2018-03-01

Consumption of whole vs. refined grain foods is recommended by nutrition or dietary guideline authorities of many countries, yet specific aspects of whole grains leading to health benefits are not well understood. Gastric emptying rate is an important consideration, as it is tied to nutrient delivery rate and influences glycemic response. Our objective was to explore two aspects of cooked rice related to gastric emptying, (1) whole grain brown vs. white rice and (2) potential effect of elevated levels of slowly digestible starch (SDS) and resistant starch (RS) from high-amylose rice. Ten healthy adult participants were recruited for a crossover design study involving acute feeding and testing of 6 rice samples (50 g available carbohydrate). Gastric emptying rate was measured using a 13 C-labeled octanoic acid breath test. A rice variety (Cocodrie) with high-amylose content was temperature-cycled to increase SDS and RS fractions. In vitro starch digestibility results showed incremental increase in RS in Cocodrie after two temperature cycles. For low-amylose varieties, SDS was higher in the brown rice form. In human subjects, low-amylose and high-amylose brown rice delayed gastric emptying compared to white rices regardless of amylose content or temperature-cycling (p < 0.05). Whole grain brown rice had slower gastric emptying rate, which appears to be related to the physical presence of the bran layer. Extended gastric emptying of brown rice explains in part comparably low glycemic response observed for brown rice.

Stimulating ammonia oxidizing bacteria (AOB) activity drives the ammonium oxidation rate in a constructed wetland (CW).

PubMed

Su, Yu; Wang, Weidong; Wu, Di; Huang, Wei; Wang, Mengzi; Zhu, Guibing

2018-05-15

An integrated approach to document high ammonium oxidation rate in Guanjinggang constructed wetland (GJG-CW) was performed and the results showed that the substantial ammonium oxidation rate could be obtained by enhancing Ammonia Oxidizing Bacteria (AOB) activity rather than Ammonia Oxidizing Archaea (AOA) activity. In the plant-bed/ditch system, ditch center and plant-bed fringe were two active zones for NH 4 + -N removal with ammonium oxidation rate peaking at 2.98±0.04 and 2.15±0.02mgNkg -1 d -1 , respectively. The enhanced AOB activity were achieved by increasing water level fluctuations, extending hydraulic retention time (HRT) and stimulating substrate availability, which subsequently enhanced NH 4 + -N removal by 34.06% in GJG-CW. However, the high AOB activity was not correlated with high AOB abundance, but was instead mostly determined by specific AOB taxa, particularly Nitrosomonas, which dominated in the active AOB. The increased cell-specific AOA activity and high AOA diversity were also achieved using those engineering measures. Although the AOA activity decreased overall with extended HRT and increased NH 4 + -N contents in GJG-CW, AOA still played a major role on ammonium oxidation in plant-bed soil. The study illustrated that artificially enhancing AOB activity and certain species in anthropogenically polluted water ecosystems would be an effective strategy to improve NH 4 + -N removal. Copyright © 2017 Elsevier B.V. All rights reserved.

Liftable Bedload Trap for Large Alpine Gravel-Bed Rivers - Experiences and Goals

NASA Astrophysics Data System (ADS)

Seitz, Hugo; Strahlhofer, Lukas; Habersack, Helmut

2010-05-01

The aim of the work is to figure out the bedload transport processes for the free flowing reach of the Drau River in Dellach, Drau Valley, amongst other measurement techniques also under the use of a recently invented liftable bedload trap. In general, there are some techniques for measuring transported debris in natural streams; we use collecting moving particles (Birkbeck-type traps, Large Helley Smith sampler) and indirectly determining transport intensity (geophones) at the study sites in Austria. In addition hydrological, geological, meteorological and other related data are collected. Two further almost fully equipped measurement stations in Lienz at the Drau River and its most important tributary Isel River, both large Alpine gravel-bed rivers, situated in the south western part of Austria are completing the integrative and innovative bedload measurement system. Former measurements in the study reach were performed also using mobile bedload samplers and fixed bedload samplers. Individually they all are adequate bedload measurement instruments - used in combination they are complementing one another, whereas each applied separately leads to specific deficits. In general the investigation pays special attention on results out of the geophone installations. The spatio-temporal distribution of the transported bedload material, its amount and the transport processes itself could be figured out. But for calibration purposes direct moving particle sampling is essential. Compared to Large Helley-Smith sampling fixed bedload traps are flood protected and robust to withstand the strain during flood conditions and so are capable to take bedload samples of e.g. a flood peak. The disadvantage of this type of direct bedload measurement is that in perennial alpine rivers the only chance to empty them and analyze their content is during the wintertime at very low water stages. Therefore a liftable bedload trap was installed direct downstream the geophone installation into the river bed of the Drau River in Dellach, Drau Valley, in 2008 as an enlargement of the since 2006 built bedload measurement system. The 1.6 m long and 0.5 m wide slot opening is held close in between measurements while the trap remains in zero position even with the river bed. During a flood event the slot can be opened unlocking the closure hydraulically. Transported bedload material is now able to enter the inner trap positioned on a balance to measure the increase of mass. The detected data is stored automatically in a computer device. Between flood events the water stage lowers and the bedload movement decreases; now it is possible to empty the trap for several times in a summer period. The trap is elevated over the water level, the cover will be dismounted and the inner trap removed with a crane for analyzing the traps content. After this the trap is inserted again and lowered ready for the next measurement. As a result it could be shown that the counted number of geophone impulses per unit time and its associated flow discharge is proportional to the trapped sediment volume. Measurements take place during the rainfall and snow melting season from May to August, and sometimes due to heavy rainfall in November. Furthermore, the assumed spatial and temporal variability of the bedload movement could now be proven. In addition it could be shown, that commonly used bedload predictors underestimate the measured bedload transport. In conclusion the results of the investigation are showing new aspects for understanding bedload transport processes, the installed traps will help to clarify the transport processes during flood events. The installed bedload measurement system will be improved and enlarged year by year. For further investigations there is a chance to test new measurement techniques under well known boundary conditions at the fully equipped gauging stations.

[Panhypopituitarism and dwarfism in a man with a primary empty sella turcica (author's transl)].

PubMed

Turpin, G; Jambart, S; de Gennes, J L

1979-03-10

Endocrine features associated with the primary empty sella turcica syndrom are rare; they are usually related to a pituitary microadenoma and more rarely to an idiopathic panhypop ituitarism. A pituitary dwarfism with an idiopathic panhypopituitarism of hypothalamic origin, associated with an "empty" sella turcica containing functional and stimulable pituitary tissue, is reported in a 27 year old male Moraccan.

[Gastric emptying of a solid-liquid meal in gastroesophageal reflux in adults].

PubMed

Bost, R; Hostein, J; Gignoux, C; Busquet, G; Lachet, B; Fournet, J

1986-04-01

Several studies concerning the relationships between gastroesophageal reflux (GOR), gastric emptying and esophageal motility are available. So far, results have been contradictory. The purpose of this work was to study gastric emptying in patients with GOR; to search for simultaneous esophageal motility disorders and to specify their type and frequency; to establish a potential relationship between motor disorders of the esophagus and the stomach in these patients. Thirty-two consecutive patients were selected according to clinical criteria, i.e. presence of at least two of the three characteristic symptoms of GOR, and the data of a three-hour post-prandial pH-metry. Gastric stasis related clinical manifestations (nausea, post-prandial vomiting, sensation of abdominal distension or of post-prandial epigastric fullness) were also searched for in all patients. A gastroscopy allowed to score esophagitis in each case. All patients, including adult controls underwent an esophageal manometry as well as a radionuclide determination of gastric emptying, after isotopic labelling of the solid (S) and liquid (L) phases of a test meal. The results showed that there was no significant modification of gastric emptying of the S and L phases of the meal in the group of patients with GOR whatever the intensity of the reflux, judged on the pH-metry results and the endoscopic data. Thus the average time of gastric half-emptying of S and L was respectively 115 and 52 min for the patients vs 111 and 51 min for the control group. As well, no correlation was found between the gastric emptying parameters and the presence or absence of clinical signs of gastric stasis or the amplitude of esophageal contraction waves. On an individual basis, two patients showed a significant decrease in gastric emptying of either the S or L phases without any attendant modification in the kinetics of the other. These results suggest that, in the adult, gastric emptying cannot be considered to be a determining factor of GOR and there are no diffuse motility disorders of the upper digestive tract during this illness.

HIV-Positive Mothers With Late Adolescent/Early Adult Children: “Empty Nest” Concerns

PubMed Central

Murphy, Debra A.; Roberts, Kathleen Johnston; Herbeck, Diane M.

2012-01-01

In-depth interviews about the “empty nest” were conducted with 57 HIV-positive mothers of late adolescent/early adult children. Empty nest worries included: (1) identity loss, (2) loss of social support, (3) financial insecurity, (4) worsening of physical health, and (5) death/dying. Hopes included: (1) self-improvement, (2) change of life focus, (3) travel, (4) romantic partners, and (5) familial ties. Respondents’ HIV/AIDS status colored their thoughts/feelings about the empty nest; some worries were specific to being HIV-positive, and would not occur for non-ill mothers. Midlife HIV positive women need healthcare/social service resources as they navigate health and social-psychological challenges to successful aging. PMID:22420679

Raman-based Oxygen and Nitrogen Sensor for Monitoring Empty Airplane Fuel Tanks

NASA Technical Reports Server (NTRS)

Chen, Peter C.

2004-01-01

The purpose of this project was to develop a Raman-based method for detecting oxygen and nitrogen in empty fuel tanks. The need for such a method comes from the potential danger of allowing explosive oxygen-fuel mixtures to accumulate in empty airplane fuel tanks. An explosion resulting from such a mixture is believed to have caused the Flight TWA 800 disaster in 1996. Recently, (e.g., February 17,2004 press release) the FAA announced its intentions to make fuel tank inerting mandatory. One potential solution to this problem is to use an inert gas such as nitrogen to flood the empty fue1 tanks in order to reduce the concentration of oxygen.

Ranitidine: forgotten drug of delayed gastric emptying.

PubMed

Veevers, Abbie E; Oxberry, Stephen G

2017-09-01

Delayed gastric emptying in the presence or absence of mechanical bowel obstruction can cause distressing symptoms in palliative care patients. We present two patients, both with vomiting due to delayed gastric emptying and gastric outlet obstruction secondary to pancreatic cancer, treated with subcutaneous ranitidine resulting in a symptomatic response. We hypothesise that ranitidine is a useful adjunct to standard treatment with prokinetic agents or octreotide in such patients and potentially those with proximal mechanical bowel obstruction from other malignancies with associated delayed gastric emptying. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

HIV-positive mothers with late adolescent/early adult children: "empty nest" concerns.

PubMed

Murphy, Debra A; Roberts, Kathleen Johnston; Herbeck, Diane M

2012-01-01

In-depth interviews about the "empty nest" were conducted with 57 HIV-positive mothers of late adolescent/early adult children. Empty nest worries included the following: (a) identity loss, (b) loss of social support, (c) financial insecurity, (d) worsening of physical health, and (e) death/dying. Hopes included the following: (a) self-improvement, (a) change of life focus, (c) travel, (d) romantic partners, and (e) familial ties. Respondents' HIV/AIDS status colored their thoughts/feelings about the empty nest; some worries were specific to being HIV positive and would not occur for nonill mothers. Midlife HIV-positive women need health care/social service resources as they navigate health and social-psychological challenges to successful aging.

Radionuclide Retention Mechanisms in Secondary Waste-Form Testing: Phase II

DOE Office of Scientific and Technical Information (OSTI.GOV)

Um, Wooyong; Valenta, Michelle M.; Chung, Chul-Woo

2011-09-26

This report describes the results from laboratory tests performed at Pacific Northwest National Laboratory (PNNL) for Washington River Protection Solutions (WRPS) to evaluate candidate stabilization technologies that have the potential to successfully treat liquid secondary waste stream effluents produced by the Hanford Tank Waste Treatment and Immobilization Plant (WTP). WRPS is considering the design and construction of a Solidification Treatment Unit (STU) for the Effluent Treatment Facility (ETF) at Hanford. The ETF, a multi-waste, treatment-and-storage unit that has been permitted under the Resource Conservation and Recovery Act (RCRA), can accept dangerous, low-level, and mixed wastewaters for treatment. The STU needsmore » to be operational by 2018 to receive secondary liquid waste generated during operation of the WTP. The STU will provide the additional capacity needed for ETF to process the increased volume of secondary waste expected to be produced by WTP. This report on radionuclide retention mechanisms describes the testing and characterization results that improve understanding of radionuclide retention mechanisms, especially for pertechnetate, {sup 99}TcO{sub 4}{sup -} in four different waste forms: Cast Stone, DuraLith alkali aluminosilicate geopolymer, encapsulated fluidized bed steam reforming (FBSR) product, and Ceramicrete phosphate bonded ceramic. These data and results will be used to fill existing data gaps on the candidate technologies to support a decision-making process that will identify a subset of the candidate waste forms that are most promising and should undergo further performance testing.« less

Mesothalamic discharge in a chronic pain, allergy and fluid retention syndrome (case report).

PubMed

Andy, O J; Nicholas, W; Dearman, C

1995-01-01

A 32-year-old woman was bedridden for a year because of chronic pain and headaches. She had insomnia, depression, suicidal thoughts and a severe chemical allergy. She had been on steroid therapy for two years and became Cushingoid with striae in the arm pits, groins and abdomen. However, she had no hypertension, nor the buffalo fat and hirsutism. She was very edematous, with a weight gain from 112 to 180 lbs. The fluid retention did not conform to the syndrome of inappropriate antidiuretic hormone. Studies revealed abnormal scalp EEG discharges and high-voltage seizure discharges in the posterior thalamus. Electrothalamic stimulation suppressed the thalamic discharges and relieved the patient's pelvic pain and headaches. After one month of several thalamic stimulations per day, she was able to get out of bed and ambulate. In addition, the patient no longer was edematous and was tolerating perfumes and floor detergents. Steroids were progressively reduced without complications of withdrawal. She went from a completely steroid dependent state to independent during the first 1-1/2 yrs of thalamic stimulation. With continued thalamic stimulation she has done well for 8-1/2 yrs, weighs 112 lbs, keeps house and drives a car. It's speculated the illness is a chronic pain multiple syndrome predominantly due to mesothalamic discharges and body infirmities. The mesothalamic discharge implicated neural networks, which represent biologic systems, i.e. pain, sleep, fluid retention, etc. Therapeutic stimulation attenuates the discharges and the neural networks return to their normal set points of homeostasis.

Determination of the Biological Efficiency and Antioxidant Potential of Lingzhi or Reishi Medicinal Mushroom, Ganoderma lucidum (Agaricomycetes), Cultivated Using Different Agro-Wastes in Malaysia.

PubMed

Sudheer, Surya; Alzorqi, Ibrahim; Ali, Asgar; Cheng, Poh Guat; Siddiqui, Yasmeen; Manickam, Sivakumar

2018-01-01

This study investigates the cultivation of Ganoderma lucidum using different agricultural biomasses from Malaysia. Five different combinations of rubber wood sawdust, empty fruit bunch fiber, and mesocarp fiber from oil palm, alone and in combination, were used to cultivate G. lucidum. Although all the substrate combinations worked well to grow the mushroom, the highest biological efficiency was obtained from the combination of empty fruit bunch fiber with sawdust. A total yield of 27% was obtained from empty fruit bunch fiber with sawdust, followed by sawdust (26%), empty fruit bunch fiber (19%), mesocarp fiber with sawdust (19%), and mesocarp fiber (16%). The quality of mushrooms was proved by proximate analysis and detection of phenolic compounds and flavonoids. The antioxidant activity verified by DPPH, ferric-reducing ability of plasma, and ABTS analyses revealed that the empty fruit bunch fiber with sawdust had higher activity than the other substrates.

SPECT/CT demonstrating 131I retention in Warthin tumor on thyroid cancer survey scan.

PubMed

Zhang, Yuyang; Minoshima, Satoshi

2013-09-01

A 48-year-old male patient of papillary thyroid cancer, status post-thyroidectomy and node dissection, was referred to (131)I scan prior to radioiodine treatment. The images showed 1 additional focus of (131)I uptake in the right upper neck outside of the thyroid bed. SPECT/CT demonstrated 2 separate foci of radioiodine uptake in the right parotid gland, instead of neck lymph nodes. Diagnostic CT showed 2 corresponding soft tissue nodules in the right parotid gland which were confirmed latter by fine-needle aspiration to be Warthin tumors. This case illustrates a pivotal role of SPECT/CT in differential diagnosis of abnormal neck uptake on (131)I thyroid cancer scan.

Anaerobic biodegradation of cyanide under methanogenic conditions.

PubMed Central

Fallon, R D; Cooper, D A; Speece, R; Henson, M

1991-01-01

Upflow, anaerobic, fixed-bed, activated charcoal biotreatment columns capable of operating at free cyanide concentrations of greater than 100 mg liter-1 with a hydraulic retention time of less than 48 h were developed. Methanogenesis was maintained under a variety of feed medium conditions which included ethanol, phenol, or methanol as the primary reduced carbon source. Under optimal conditions, greater than 70% of the inflow free cyanide was removed in the first 30% of the column height. Strongly complexed cyanides were resistant to removal. Ammonia was the nitrogen end product of cyanide transformation. In cell material removed from the charcoal columns, [14C]bicarbonate was the major carbon end product of [14C]cyanide transformation. PMID:1872600

Effect of cisapride on gastric emptying in dyspeptic patients.

PubMed

Urbain, J L; Siegel, J A; Debie, N C; Pauwels, S P

1988-07-01

The effect of the new gastrokinetic agent cisapride on gastric emptying was evaluated in 17 dyspeptic patients using the dual radionuclide technique. Eight patients with idiopathic dyspepsia and nine postsurgical dyspeptic patients were studied and compared to a control group. Gastric emptying of solids and liquids was determined after ingestion of a standardized meal using 99mTc-sulfur colloid scrambled eggs as the solid phase and [111In]DTPA-labeled water as the liquid phase. Following a basal study and on a separate occasion, each patient received an intravenous bolus of 10 mg of cisapride after ingestion of the test meal; 10 of the patients were restudied after a two-week period of chronic oral administration of the drug (10 mg four times a day). Baseline gastric emptying of solids was significantly delayed in idiopathic and postsurgical patients; liquid emptying was only delayed in the postsurgical group. Intravenous and oral administration of cisapride significantly shortened gastric emptying in both groups. In all but one patient, the clinical improvement was confirmed by the test. Cisapride appears to be a good alternative to metoclopramide and domperiodone in the treatment of dyspeptic patients. The dual radionuclide technique appears to be a useful physiologic tool for evaluating and predicting the efficacy of a gastric prokinetic therapy in man.

Gastric emptying of multi-particulate dosage forms.

PubMed

Newton, J Michael

2010-08-16

The evidence in the literature for the concept that multi-particulate dosage forms below a specific size empty from the stomach as if they were liquids and hence have the potential to provide the best solution to the formulation of controlled release oral dosage forms, has been considered. There is some evidence that particles less than 1.0mm provide a more rapid response than larger size particles but there is also evidence that this is not always the case and that rapid and reproducible gastric emptying of small particles does not always occur when they are administered. There is strong evidence that food can delay the gastric emptying of multi-particulate systems. Some of the misconception for gastric emptying performance of multi-particulate system is shown to be related to the limitation of the study design and limitation of the way the data is processed. Nevertheless, there is clear evidence that multi-particulate systems can provide effective oral controlled release dosage forms. There is still some way to go with experimental techniques which would allow a definitive answer to the issue of how the variability of the gastric emptying of multi-particulate systems of less than 2.0mm arises. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Steady- and transient-state H2S biofiltration using expanded schist as packing material.

PubMed

Romero Hernandez, A C; Rodríguez Susa, M S; Andrès, Y; Dumont, E

2013-01-25

The performances of three laboratory-scale biofilters (BF1, BF2, BF3) packed with expanded schist for H(2)S removal were studied at different empty bed residence times (EBRT=35, 24 and 16s) in terms of elimination capacity (EC) and removal efficiency (RE). BF1 and BF2 were filled with expanded schist while BF3 was filled with both expanded schist and a nutritional material (UP20; 12% vol). BF1 and BF3 were inoculated with activated sludge, whereas BF2 was not inoculated. A maximum EC of 42 g m(-3) h(-1) was recorded for BF3 at EBRT=35 s demonstrating the ability of schist to treat high H(2)S loading rates, and the ability of UP20 to improve H(2)S removal. Michaelis-Menten and Haldane models were fitted to the experimental elimination capacities while biofilter responses to transient-state conditions in terms of removal efficiency during shock load events were also evaluated for BF1 and BF3. Copyright © 2012 Elsevier B.V. All rights reserved.

Gas phase bio-filter for the removal of triethylamine (TEA) from air: microbial diversity analysis with reference to design parameters.

PubMed

Gandu, Bharath; Sandhya, K; Gangagni Rao, A; Swamy, Y V

2013-07-01

Biotic (packed bio-filter; PBF) and abiotic (packed filter; PF) studies were carried out on two similar 2L gas phase filters for the removal of triethylamine (TEA) at inlet concentration in the range of 250-280 ppmV. Removal efficiency (RE) of PBF remained in the range of 90-99% during the stable period of operation (170 days) whereas RE of PF dropped gradually to 10% in a span of 90 days. Five different bacterial species viz; Aeromonas sp., Alcaligenes sp., Arthrobacter sp., Klebsiella sp., and Pseudomonas sp., were identified in PBF. It was observed that diethyl amine, ethylamine and nitrate were formed as metabolites during the degradation pathway. Empty bed residence time of 20s, mass loading rate of 202.26 g/m(3)/h, space velocity of 178.82 m(3)/m(3)/h and elimination capacity of 201.52 g/m(3)/h were found to be optimum design parameters for PBF to get RE in the range of 90-99%. Copyright © 2013 Elsevier Ltd. All rights reserved.

Performance of a pilot-scale biotrickling filter in controlling the volatile organic compound emissions in a furniture manufacturing facility.

PubMed

Martínez-Soria, Vicente; Gabaldón, Carmen; Penya-Roja, Josep M; Palau, Jordi; Alvarez-Hornos, F Javier; Sempere, Feliu; Soriano, Carlos

2009-08-01

A 0.75-m3 pilot-scale biotrickling filter was run for over 1 yr in a Spanish furniture company to evaluate its performance in the removal of volatile organic compounds (VOCs) contained in the emission of two different paint spray booths. The first one was an open front booth used to manually paint furniture, and the second focus was an automatically operated closed booth operated to paint pieces of furniture. In both cases, the VOC emissions were very irregular, with rapid and extreme fluctuations. The pilot plant was operated at an empty bed residence time (EBRT) ranging from 10 to 40 sec, and good removal efficiencies of VOCs were usually obtained. When a buffering activated carbon prefilter was installed, the system performance was improved considerably, so a much better compliance with legal constraints was reached. After different shutdowns in the factory, the period to recover the previous performance of the biotrickling reactor was minimal. A weekend dehydration strategy was developed and implemented to control the pressure drop associated with excessive biomass accumulation.

Effect of ozone on biopolymers in biofiltration and ultrafiltration processes.

PubMed

Siembida-Lösch, Barbara; Anderson, William B; Wang, Yulang Michael; Bonsteel, Jane; Huck, Peter M

2015-03-01

The focus of this full-scale study was to determine the effect of ozone on biopolymer concentrations in biofiltration and ultrafiltration (UF) processes treating surface water from Lake Ontario. Ozonation was out of service for maintenance for 9 months, hence, it was possible to investigate ozone's action on biologically active carbon contactors (BACCs) and UF, in terms of biopolymer removal. Given the importance of biopolymers for fouling, this fraction was quantified using a chromatographic technique. Ozone pre-treatment was observed to positively impact the active biomass in biofilters. However, since an increase of the active biomass did not result in higher biopolymer removal, active biomass concentration cannot be a surrogate for biofiltration performance. It was evident that increasing empty bed contact time (EBCT) from 4 to 19 min only had a positive effect on biopolymer removal through BACCs when ozone was out of service. However, as a mass balance experiment showed, ozone-free operation resulted in higher deposition of biopolymers on a UF membrane and slight deterioration in its performance. Copyright © 2014 Elsevier Ltd. All rights reserved.

Ethics of re-hearsing procedures on a corpse.

PubMed

Jones, James W; McCullough, Laurence B

2011-09-01

You are the attending surgeon of a homeless pedestrian who sustained multiple injuries when struck by a car. He died soon after being brought to the emergency department. It is late in the evening. A first-year resident and a medical student have been helping with the failed attempt at resuscitation. The emergency department is empty, except for your case. A central line kit lies on the bed, opened but not used. The junior resident asks your permission for herself and the student to practice the technique of subclavian cauterization and tracheal intubation on the fresh cadaver to get a "feel" for the procedures. There is no medical simulation for these procedures at your medical center. The best ethical response is: A. Tell them to go ahead and practice. B. They can only practice intubation because it leaves no external wounds. C. You should supervise them yourself to assure educational benefit. D. They should wait until you get permission from the medical examiner. E. The present case is not appropriate for educational purposes. Copyright © 2011 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.

Removal of bromide and bromate from drinking water using granular activated carbon.

PubMed

Zhang, Yong-Qing; Wu, Qing-Ping; Zhang, Ju-Mei; Yang, Xiu-Hua

2015-03-01

Granular activated carbon (GAC) was used to remove bromide (Br⁻) and bromate (BrO(3)(-)) from drinking water in both bench- and pilot-scale experiments. The present study aims to minimize BrO(3)(-) formation and eliminate BrO(3)(-) generated during the ozonation of drinking water, particularly in packaged drinking water. Results show that the Br⁻ and BrO(3)(-) levels in GAC-treated water decreased in both bench- and pilot-scale experiments. In the bench-scale experiments, when the empty bed contact time (EBCT) was 5 min, the highest reduction rates of Br(-) in the mineral and ultrapure water were found to be 74.9% and 91.2%, respectively, and those of BrO(3)(-) were 94.4% and 98.8%, respectively. The GAC capacity for Br⁻ and BrO(3)(-) removal increased with the increase in EBCT. Reduction efficiency was better in ultrapure water than in mineral water. In the pilot-scale experiments, the minimum reduction rates of Br⁻ and BrO(3)(-) were 38.5% and 73.2%, respectively.

Rapid small-scale column testing of granular activated carbon for organic micro-pollutant removal in treated domestic wastewater.

PubMed

Zietzschmann, F; Müller, J; Sperlich, A; Ruhl, A S; Meinel, F; Altmann, J; Jekel, M

2014-01-01

This study investigates the applicability of the rapid small-scale column test (RSSCT) concept for testing of granular activated carbon (GAC) for organic micro-pollutants (OMPs) removal from wastewater treatment plant (WWTP) effluent. The chosen experimental setup was checked using pure water, WWTP effluent, different GAC products, and variable hydrodynamic conditions with different flow velocities and differently sized GAC, as well as different empty bed contact times (EBCTs). The setup results in satisfying reproducibility and robustness. RSSCTs in combination with WWTP effluent are effective when comparing the OMP removal potentials of different GAC products and are a useful tool for the estimation of larger filters. Due to the potentially high competition between OMPs and bulk organics, breakthrough curves are likely to have unfavorable shapes when treating WWTP effluent. This effect can be counteracted by extending the EBCT. With respect to the strong competition observed in GAC treatment of WWTP effluent, the small organic acid and neutral substances are retained longer in the RSSCT filters and are likely to cause the majority of the observed adsorption competition with OMPs.

Air pollution control through biotrickling filters: a review considering operational aspects and expected performance.

PubMed

Schiavon, Marco; Ragazzi, Marco; Rada, Elena Cristina; Torretta, Vincenzo

2016-12-01

The biological removal of pollutants, especially through biotrickling filters (BTFs), has recently become attractive for the low investment and operational costs and the low secondary pollution. This paper is intended to investigate the state of the art on BTF applications. After an overview on the biodegradation process and the typical parameters involved, this paper presents the analysis of a group of 16 literature studies chosen as the references for this sector. The reference studies differ from one another by the pollutants treated (volatile organic compounds [VOC], hydrogen sulphide, nitrogen oxides and trimethylamine), the geometry and size of the BTFs, and the procedures of the tests. The reference studies are analyzed and discussed in terms of the operational conditions and the results obtained, especially with respect to the removal efficiencies (REs) and the elimination capacities (ECs) of the pollutants considered. Empty bed residence time (EBRT), pollutant loading rate, temperature, pH, oxygen availability, trickling liquid flow rate, inoculum selection and biomass control strategies revealed to be the most important operational factors influencing the removal performance of a BTF.

Effects of anionic surfactant on n-hexane removal in biofilters.

PubMed

Cheng, Yan; He, Huijun; Yang, Chunping; Yan, Zhou; Zeng, Guangming; Qian, Hui

2016-05-01

The biodegradability of three anion surfactants by biofilm microorganisms and the toxicity of the most readily biodegradable surfactant to biofilm microorganisms were examined using batch experiments, and the optimal concentration of SDS for enhanced removal of hexane was investigated using two biotrickling filters (BTFs) for comparison. Results showed that SDS could be biodegraded by microorganisms, and its toxicity to microorganisms within the experimental range was negligible. The best concentration of SDS in biofiltration of n-hexane was 0.1 CMC and the elimination capacity (EC) of 50.4 g m(-3) h(-1) was achieved at a fixed loading rate (LR) of 72 g m(-3) h(-1). When an inlet concentration of n-hexane increased from 600 to 850 mg m(-3), the removal efficiency (RE) decreased from 67% to 41% by BTF2 (with SDS) and from 52% to 42% by BTF1 (without SDS). SDS could enhance hexane removal from 43% (BTF1) to 60% (BTF2) at gas empty-bed residence time (EBRT) of 7.5 s and an inlet concentration of 200 mg m(-3). Copyright © 2016. Published by Elsevier Ltd.