Selective Catalyst Reduction(SCR)Urea Dosing System(UDS)directly affects the system accuracy and the dynamic response performance of a vehicle.However,the UDS dynamic response is hard to keep up with the changes o...Selective Catalyst Reduction(SCR)Urea Dosing System(UDS)directly affects the system accuracy and the dynamic response performance of a vehicle.However,the UDS dynamic response is hard to keep up with the changes of the engine's operating conditions.That will lead to low NO_χconversion efficiency or NH_3 slip.In order to optimize the injection accuracy and the response speed of the UDS in dynamic conditions,an advanced control strategy based on an air-assisted volumetric UDS is presented.It covers the methods of flow compensation and switching working conditions.The strategy is authenticated on an UDS and tested in different dynamic conditions.The result shows that the control strategy discussed results in higher dynamic accuracy and faster dynamic response speed of UDS.The inject deviation range is improved from being between-8%and 10%to-4%and 2%and became more stable than before,and the dynamic response time was shortened from 200 ms to 150 ms.The ETC cycle result shows that after using the new strategy the NH_3 emission is reduced by 60%,and the NO_χemission remains almost unchanged.The trade-off between NO_χconversion efficiency and NH_3 slip is mitigated.The studied flow compensation and switching working conditions can improve the dynamic performance of the UDS significantly and make the UDS dynamic response keep up with the changes of the engine's operating conditions quickly.展开更多
The principle and working process of Vacuum Resin Shot Dosing Equipment(VRSDE) are analyzed and the characteristics of IP1612-220PLC (Programmable Logical Controller) areintroduced briefly at first. Then the authors d...The principle and working process of Vacuum Resin Shot Dosing Equipment(VRSDE) are analyzed and the characteristics of IP1612-220PLC (Programmable Logical Controller) areintroduced briefly at first. Then the authors discuss the flow of program, the assignment of PLCI/O ports, the wiring diagram, and the ladder logic program of the PLC control system of VRSDE indetail. Some application issues of the system are accounted for in addition. Finally, according tothe information acquired from users, the authors draw the conclusion: this system owns a highreliability and a-vailability and greatly improves the automatic degree of VRDE.展开更多
Ultrahigh-dose-rate radiotherapy(FLASH-RT)is a revolutionary radiotherapy technology that can spare normal tissues without compromising tumor control.Although qualitative experimental results have been reported,quanti...Ultrahigh-dose-rate radiotherapy(FLASH-RT)is a revolutionary radiotherapy technology that can spare normal tissues without compromising tumor control.Although qualitative experimental results have been reported,quantitative and systematic analysis of data is necessary.Particularly,the FLASH effect response model to the dose or dose rate is still unclear.This study investigated the relationships between the FLASH effect and experimental parameters,such as dose,dose rate,and other factors by analyzing published in vivo experimental data from animal models.The data were modeled based on logistic regression analysis using the sigmoid function.The model was evaluated using prediction accuracy,receiver operating characteristic(ROC)curve,and area under the ROC curve.Results showed that the FLASH effect was closely related to the dose,mean dose rate,tissue type,and corresponding biological endpoints.The dose rate corresponding to a 50% probability of triggering cognitive protection in the brain was 45 Gy s^(-1).The dose rate corresponding to a 50% probability of triggering intestinal crypt survival and regeneration was 140 Gy s^(-1).For the skin toxicity effect,the dose corresponding to a 50% probability of triggering the FLASH effect was 24 Gy.This study helps to characterize the conditions underlying the FLASH effect and provides important information for optimizing experiments.展开更多
On the basis of the analysis of faults and their causes of vacuum resin shot dosing equipment, the fuzzy model of fault diagnosis for the equipment is constructed, and the fuzzy relationship matrix, the symptom fuzzy ...On the basis of the analysis of faults and their causes of vacuum resin shot dosing equipment, the fuzzy model of fault diagnosis for the equipment is constructed, and the fuzzy relationship matrix, the symptom fuzzy vector, the fuzzy compound arithmetic operator, and the diagnosis principle of the model are determined. Then the fault auto-diagnosis system for the equipment is designed , and the functions for real-time monitoring its operation condition and for fault auto diagosis are realized. Finally, the experiments of fault auto-diagnosis are conducted in practical production and the veracity of the system is verified.展开更多
In this editorial I comment on the article,published in the current issue of the World Journal of Clinical Oncology.Primary central nervous system lymphoma(PCNSL)is a disease of elderly and immunocompromised patients....In this editorial I comment on the article,published in the current issue of the World Journal of Clinical Oncology.Primary central nervous system lymphoma(PCNSL)is a disease of elderly and immunocompromised patients.The authors reported clinical results of 19 patients with PCNSL treated with zanubrutinib/high dose methotrexate(HD-MTX)until disease progression.They demonstrated that the combination of zanubrutinib with HD-MTX led to a marked clinical response and tolerability among these patients.They also observed that cerebrospinal fluid liquid biopsy to detect circulating tumor DNA may be a good option for evaluating treatment response and tumor burden in patients with PCNSL.PCNSL is a challenging disease for treatment as these patients present with different neurological states and comorbidities.Treatment has evolved over the years from whole brain radiotherapy to HD-MTX followed by autologous stem cell transplant.Gradually,treatment of patients with PCNSL is going to become individualized.展开更多
AIM: To compare(using the Ottawa Bowel Preparation Scale) the efficacy of split-dose vs morning administration of polyethylene glycol solution for colon cleansing in patients undergoing colonoscopy, and to assess the ...AIM: To compare(using the Ottawa Bowel Preparation Scale) the efficacy of split-dose vs morning administration of polyethylene glycol solution for colon cleansing in patients undergoing colonoscopy, and to assess the optimal preparation-to-colonoscopy interval.METHODS: Single-centre, prospective, randomized, investigator-blind stud in an academic tertiarycare centre. Two hundred patients requiring elective colonoscopy were assigned to receive one of the two preparation regimens(split vs morning) prior to colonoscopy. Main outcome measurements were bowel preparation quality and patient tolerability.RESULTS: Split-dose regimen resulted in better bowel preparation compared to morning regimen [Ottawascore mean 5.52(SD 1.23) vs 6.02(1.34); P = 0.017]. On subgroup analysis, for afternoon procedures, both the preparations were equally effective(P = 0.756). There was no difference in tolerability and compliance between the two regimens.CONCLUSION: Overall, previous evening- same morning split-dosing regimen results in better bowel cleansing for colonoscopy compared to morning preparation. For afternoon procedures, both schedules are equally effective; morning preparation may be more convenient to the patient.展开更多
The paper presents a computer code system 'SRDAAR- QNPP' for the real-time dose as-sessment of an accident release for Qinshan Nuclear Power Plant. It includes three parts:thereal-time data acquisition system,...The paper presents a computer code system 'SRDAAR- QNPP' for the real-time dose as-sessment of an accident release for Qinshan Nuclear Power Plant. It includes three parts:thereal-time data acquisition system, assessment computer. and the assessment operating code system. InSRDAAR-QNPP, the wind field of the surface and the lower levels are determined hourly by using amass consistent three-dimension diasnosis model with the topographic following coordinate system.A Lagrangin Puff model under changing meteorological condition is adopted for atmosphericdispersion, the correction for dry and wet depositions. physical decay and partial plume penetrationof the top inversion and the deviation of plume axis caused by complex terrain have been taken in-to account. The calculation domain areas include three square grid areas with the sideline 10 km, 40krn and 160 km and a grid interval 0.5 km, 2.0 km, 8.0 km respectively. Three exposure pathwaysare taken into account:the external exposure from immersion cloud and passing puff, the internalexposure from inhalation and the external exposure from contaminated ground. This system is ableto provide the results of concentration and dose distributions within 10 minutes after the data havebeen inputed.展开更多
Restraining algal growth by algaecide has been studied by many researchers, but the dosing time has not yet been studied. In this study, we examined the appropriate dosing time of algaecide through a series of experim...Restraining algal growth by algaecide has been studied by many researchers, but the dosing time has not yet been studied. In this study, we examined the appropriate dosing time of algaecide through a series of experiments. In the experiments, the pH value of water is significantly affected by Microcystis aeruginosa, and the variation of the pH value is in favor of the growth of the alga. Therefore, using acid algaecide in the period with maximum pH values, i.e., the stable phase, would change the acidity-alkalinity of the water significantly, and would negatively affect algal growth. Acid algaecide does not eliminate the alga effectively if the acid algaecide is dosed in the logarithmic growth phase. Using acid algaecide in the decline phase after algal bloom not only is unfavorable for eliminating the alga, but also prolongs the decline phase, and even brings about next larger algal bloom.展开更多
Optically stimulated luminescence(OSL) reading systems are becoming smaller and capable of real-time detection. To improve real-time and multipurpose radiation dosimetry readings, we built a real-time continuous-wave(...Optically stimulated luminescence(OSL) reading systems are becoming smaller and capable of real-time detection. To improve real-time and multipurpose radiation dosimetry readings, we built a real-time continuous-wave(RCW) OSL reading system. This system is both small and lightweight, and it employs powerful laser excitation(478 mW/cm^2) at the dosimetry probe location. We investigate the possibility of using the RCW mode to read the radiation luminescence(RL) or OSL by using a singlecrystal Al_2O_3:C dosimeter in a low-dose-rate137 Cs y field.Our results indicate that the RL/OSL follows a stable and uniform distribution. The minimum detected doses associated with the RL, OSL, and RL + OSL signals are2.1 9 10^(-2), 3.17 9 10^(-1), and 5.7 9 10^(-2) l Gy, respectively. This device provides a framework for the future development of applications for practical radiation dose measurements.展开更多
AIM To determine the preventive effect and safetyof proton pump inhibitors (PPIs) in low-dose aspirin(LDA)-associated gastrointestinal (GI) ulcers andbleeding.METHODS: We searched MEDLINE, EMBASE and theCochran...AIM To determine the preventive effect and safetyof proton pump inhibitors (PPIs) in low-dose aspirin(LDA)-associated gastrointestinal (GI) ulcers andbleeding.METHODS: We searched MEDLINE, EMBASE and theCochrane Controlled Trials Register from inception toDecember 2013, and checked conference abstracts ofrandomized controlled trials (RCTs) on the effect ofPPIs in reducing adverse GI events (hemorrhage, ulcer,perforation, or obstruction) in patients taking LDA.The preventive effects of PPIs were compared with thecontrol group [taking placebo, a cytoprotective agent,or an H2 receptor antagonist (H2RA)] in LDA-associatedupper GI injuries. The meta-analysis was performedusing RevMan 5.1 software.RESULTS: We evaluated 8780 participants in 10 RCTs.The meta-analysis showed that PPIs decreased the riskof LDA-associated upper GI ulcers (OR = 0.16; 95%CI:0.12-0.23) and bleeding (OR = 0.27; 95%CI: 0.16-0.43)compared with control. For patients treated with dualanti-platelet therapy of LDA and clopidogrel, PPIs wereable to prevent the LDA-associated GI bleeding (OR =0.36; 95%CI: 0.15-0.87) without increasing the riskof major adverse cardiovascular events (MACE) (OR =1.00; 95%CI: 0.76-1.31). PPIs were superior to H2RAin prevention of LDA-associated GI ulcers (OR = 0.12;95%CI: 0.02-0.65) and bleeding (OR = 0.32; 95%CI:0.13-0.79).CONCLUSION: PPIs are effective in preventing LDAassociatedupper GI ulcers and bleeding. Concomitantuse of PPI, LDA and clopidogrel did not increase therisk of MACE.展开更多
The effects of potassium permanganate(KMnO_4)dosing position on the natural organic matter(NOM)removal as well as membrane fouling were investigated in the coagulation/ultrafiltration combined process.KMnO_4 oxidation...The effects of potassium permanganate(KMnO_4)dosing position on the natural organic matter(NOM)removal as well as membrane fouling were investigated in the coagulation/ultrafiltration combined process.KMnO_4 oxidation altered the NOM characteristics in terms of hydrophobicity and molecular weight,and destroyed humic substances originated from terraneous organisms in raw water.The optimal KMnO_4 dosage was 0.5 mg·L^(-1) in the peroxidation enhanced coagulation process with respect to the dissolved organic carbon(DOC)removal.When KMnO_4 was dosed into both upstream and downstream of coagulation,namely in the proposed twoposition dosing mode,coagulation and KMnO_4 oxidation worked individually on the apparent DOC removal.However,compared to the KMnO_4 addition prior to or after coagulation,the two-position dosing mode dramatically alleviated membrane fouling and reduced fouling irreversibility.This was attributed to the change of NOM characteristics as a result of KMnO_4 addition prior to coagulation and the presence of MnO_2 on membrane surface as a result of KMnO_4 addition prior to ultrafiltration.This work may provide useful information for the application of KMnO_4 oxidation in the coagulation/ultrafiltration combined system.展开更多
Dose in radiation therapy has been reported as the water-equivalent dose using conventional dose calculation algorithms. The Monte Carlo (MC) algorithm employs characterization of human tissues by elemental compositio...Dose in radiation therapy has been reported as the water-equivalent dose using conventional dose calculation algorithms. The Monte Carlo (MC) algorithm employs characterization of human tissues by elemental composition and mass density. It enables more accurate dose calculation for radiation therapy treatment planning and typically reports absorbed dose to medium. Whether one should use dose to medium or tissue (Dm) in place of dose to water (Dw) for MC treatment planning remains the subject of debate. The aim of the current study is to evaluate the differences between dose-volume indices for Dm and Dw MC-calculated IMRT plans. Thirty-seven spine patients were selected for this study. The IMRT optimization and MC calculations were performed using the iPlan RT DoseTM ver 4.1.2 (Brainlab, Munich, Germany) treatment planning system (TPS) with an X-ray Voxel Monte Carlo (XVMC) dose calculation engine. Dw and Dm results for target and critical structures were evaluated using the dose-volume-based indices. Systematic differences between dose-volume indices computed with Dw and Dm were up to 5.2%, 4.2%, and 4.5% for D2, D50 and D98 indices of the clinical target volume (CTV), respectively and up to 1% for the critical structure dose indices. Our study demonstrates that employing Dm in place of Dw in MC-calculated IMRT treatment plans introduces a significant systematic difference in target DVHs. We recommend that for diffused target structures (such as spine tumors), dose to water is a better quantity for dose prescription in photon beam treatment planning using existing MC TPS. While for critical structures, it would be reasonable to report Dm always. However in future with the availability of finer spatial resolution, Dm will be the most suitable variable for both target and critical structures’ dose prescription and reporting in MC treatment planning.展开更多
Background: Magnetic resonance image-guided radiation therapy (MR-IGRT) promises more precise and effective radiation treatments compared to conventional IGRT by using real-time on-board MR imaging. Under the influenc...Background: Magnetic resonance image-guided radiation therapy (MR-IGRT) promises more precise and effective radiation treatments compared to conventional IGRT by using real-time on-board MR imaging. Under the influence of a magnetic field, however, secondary electrons exiting a surface can be forced in a circular path and re-enter the medium, resulting in dose increase at a beam-exit surface, called the electron return effect (ERE). The purpose of the study is to compare the exit skin dose computed by Monte Carlo dose calculation with measurements using an adult anthropomorphic phantom and to measure the effect of skin dose reduction by adding 1 cm-thick bolus. Method: The plan was compared with measurements using an adult anthropomorphic phantom combined with radiochromic films and thermoluminescent dosimeters. We also measured the skin dose reduction by adding 1 cm-thick bolus on the frontal surface of the phantom. Results: We found that 1 cm-thick bolus reduced the skin dose by up to 20% both in measurements and calculations. The plan was found to overestimate the measured skin dose by about 10% and there was no significant difference in the bolus effect between the breast skin and the skin (without breast attachment) doses. Conclusion: In conclusion, we confirmed the ERE effect on the anthropomorphic phantom under the magnetic field and the exit skin dose reduction by adding a bolus. Skin dose measurements using anthropomorphic phantom may be helpful to evaluate more realistic skin dose and the bolus effect in the magnetic field.展开更多
Faults of vacuum resin shot dosing equipment are studied systematically and the fault tree of the system is constructed by using the fault tree analysis(FTA) method. Then the qualitative and quantitative analysis of t...Faults of vacuum resin shot dosing equipment are studied systematically and the fault tree of the system is constructed by using the fault tree analysis(FTA) method. Then the qualitative and quantitative analysis of the tree is carried out, respectively, and according to the results of the analysis, the measures to improve the system are worked out and implemented. As a result, the reliability of the equipment is enhanced greatly.展开更多
BACKGROUND:The study aimed to determine the frequency of enoxaparin dosing errors for patients who had a measured emergency department(ED)weight compared to those who did not have a measured ED weight,and to determine...BACKGROUND:The study aimed to determine the frequency of enoxaparin dosing errors for patients who had a measured emergency department(ED)weight compared to those who did not have a measured ED weight,and to determine if demographic variables(e.g.,weight,height,age,Englishspeaking,race)impact the likelihood of receiving an inappropriate dose.METHODS:This is a retrospective,electronic chart review of patients who received a dose of enoxaparin in the ED between January 1,2008 and July 1,2013.We identified all patients>18 years who received a dose of enoxaparin while in the ED,were admitted,and had at least one inpatient weight within the first four days of hospitalization.Patients were excluded if they received enoxaparin for prophylaxis or a dose of more than 1.25mg/kg.RESULTS:A total of 1,944 patients were included.Patients were more likely to experience an error if they did not have a measured ED weight.Over-doses of>10mg were more likely to occur in patients without a measured ED weight.Patients with no documented ED weight or with a staffestimated ED weight were more likely to experience a dosing error than those with a patient-stated weight.Patients were more likely to experience an error if their first inpatient weight was more than 96kg,they were more than 175-cm tall,or were English speaking.CONCLUSION:Dosing errors are more likely to occur when patients are not weighed in the ED.Modifications to current workflows to incorporate weighing those patients who receive weightdosed medications may be warranted.展开更多
While the incidence of toddlers’ diabetes is soaring,their mainstay insulins were withdrawn,namely the weak 10% or 20% insulin mixtures (WIM),which were injected only once or twice daily.Consequently,toddlers are coe...While the incidence of toddlers’ diabetes is soaring,their mainstay insulins were withdrawn,namely the weak 10% or 20% insulin mixtures (WIM),which were injected only once or twice daily.Consequently,toddlers are coerced to use an insulin pump,multi-dose insulin regime (MuDIR),mix or dilute insulins.This paper highlights the difficulties and proposes a simple solution.While an insulin pump is the best available option,it is not readily available for everyone.Mixing insulins is not sufficiently precise in small doses.Although diluting insulin would allow precise dosing and reduce the dose variability secondary to dribbling after injections,it,like insulin mixing,deprives children from using the pen and related child-friendly accessories.In MuDIR,we inject 4-5 small doses of insulin instead of 1-2 daily larger doses of WIM.Thus,on using a half unit (unit) insulin pen,a dose of 0.5,1,1.5 and 2 units are adjusted in steps of 100%,50%,33% or 25%;unlike the advisable 5%-20%.This does not easily match the tiny erratic meals of grazing toddlers.Maternal anxiety peaks on watching yo-yoing glycemia.Carers have to accept either persistently high sugar or wild fluctuation.The risks of such poor glycemic pattern are increasingly recognized.Using insulin U20 in a unit disposable pen allows deci-unit dosing,with 5%-20% dose-tuning,greater accuracy on delivering small doses and reduction of dose variability from dribbling.Deci-unit dosing may help avoid wide glycemic swings and provide the affordable alternative to insulin pumps for toddlers.Deci-unit pen materializes the Human Rights of Children,a safer and effective treatment.展开更多
A front-end electronics of dose monitor has been developed for measuring irradiation dose to the patient in Shanghai Advanced Proton Therapy Facility.The parallel plate ionization chamber is used for the dose monitori...A front-end electronics of dose monitor has been developed for measuring irradiation dose to the patient in Shanghai Advanced Proton Therapy Facility.The parallel plate ionization chamber is used for the dose monitoring.Unlike the traditional method of recycling capacitor integration and voltage-to-frequency conversion,this dose monitor electronics uses the trans-impedance amplifier and analog-to-digital conversion method.It performs satisfactorily,with the integral nonlinearity of less than ±0.04 nA in the range of-400 to 50 nA and the resolution of about±0.6 nA.展开更多
In view of the wide use of plants as test systems theeffects of acute and chronic exposure were comparedon seeds of Pisum sativum and in meristematic cellsof Allium sativum root tips.The two salts comparedwere zirconi...In view of the wide use of plants as test systems theeffects of acute and chronic exposure were comparedon seeds of Pisum sativum and in meristematic cellsof Allium sativum root tips.The two salts comparedwere zirconium oxychloride and known to be ubiquitousin plant systems and thallium acetate known for toxiceffects in high doses.Seeds were soaked in展开更多
AIM To compare the efficacy of fixed-time split dose and split dose of an oral sodium picosulfate for bowel preparation.METHODS This is study was prospective, randomized controlled study performed at a single Institut...AIM To compare the efficacy of fixed-time split dose and split dose of an oral sodium picosulfate for bowel preparation.METHODS This is study was prospective, randomized controlled study performed at a single Institution(2013-058). A total of 204 subjects were assigned to receive one of two sodium picosulfate regimens(i.e., fixed-time split or split) prior to colonoscopy. Main outcome measurements were bowel preparation quality and subject tolerability.RESULTS There was no statistical difference between the fixedtime split dose regimen group and the split dose regimen group(Ottawa score mean 2.57 ± 1.91 vs 2.80 ± 2.51, P = 0.457). Cecal intubation time and physician's satisfaction of inspection were not significantly different between the two groups(P = 0.428, P = 0.489). On subgroup analysis, for afternoon procedures, the fixed-time split dose regimen was equally effective as compared with the split dose regimen(Ottawa score mean 2.56 ± 1.78 vs 2.59 ± 2.27, P = 0.932). There was no difference in tolerability or compliance between the two groups. Nausea was 21.2% in the fixed-time split dose group and 14.3% in the split dose group(P = 0.136). Vomiting was 7.1% and 2.9%(P = 0.164), abdominal discomfort 7.1% and 4.8%(P = 0.484), dizziness 1% and 4.8%(P = 0.113), cold sweating 1% and 0%(P = 0.302) and palpitation 0% and 1%(P = 0.330), respectively. Sleep disturbance was two(2%) patients in the fixed-time split dose group and zero(0%) patient in the split dose preparation(P = 0.143) group.CONCLUSION A fixed-time split dose regimen with sodium picosulfate is not inferior to a split dose regimen for bowel preparation and equally effective for afternoon colonoscopy.展开更多
Background: Health worker shortages remain a significant challenge to delivery of health care services globally. Moving tasks, where appropriate, to less specialized health workers is recommended by the World Health O...Background: Health worker shortages remain a significant challenge to delivery of health care services globally. Moving tasks, where appropriate, to less specialized health workers is recommended by the World Health Organization as a strategy to address this challenge. However, this concept is feared to raise specific quality concerns. This research aimed at assessing the performance of health workers to correctly prescribe (target) appropriate antimalarial treatment. Methods: We conducted a cross sectional study at three public health centre IVs in Uganda, with varying malaria transmission intensities (Kihihi-low, Kasambya-medium and Nagongera-high). We categorized prescribers into two groups: specialized prescribers (doctors and clinical officers) and less specialized prescribers (nurses and midwives). At each site, 100 records of patients seen between September and November 2011 and prescribed an antimalarial were retrieved for each group of prescribers. Correctness of the antimalarial drug prescribed and dose given were assessed for each group and compared to the 2005 Uganda national malaria treatment guidelines which recommend Artemether Lumefantrine (AL) for treatment of uncomplicated malaria and Quinine for complicated malaria. Results: Findings of the study showed that specialized health workers were more likely to target correctly as compared to the less specialized health workers [OR = 1.49 (1.00 - 2.22), p = 0.046]. Appropriateness of dosing was higher among specialized prescribers compared to less specialized prescribers however this was not significant [OR = 1.58 (0.77 - 3.25), p = 0.206]. Age of the participants, history of fever, diagnosis of malaria and prescription experience were not associated with correct targeting. Conclusion: This study shows that task shifting at the targeting level is not suitable;however, there is inadequate evidence to show that this also applies to anti-malarial dosing. Task shifting for the treatment of Malaria in Uganda should be investigated further using larger studies if it is to be considered as an option for solving the health worker shortages especially in regions with few specialized health workers but high malaria burden.展开更多
基金Supported by National Hi-tech Research and Development Program of China(863 Program,Grant No.2012AA111708)
文摘Selective Catalyst Reduction(SCR)Urea Dosing System(UDS)directly affects the system accuracy and the dynamic response performance of a vehicle.However,the UDS dynamic response is hard to keep up with the changes of the engine's operating conditions.That will lead to low NO_χconversion efficiency or NH_3 slip.In order to optimize the injection accuracy and the response speed of the UDS in dynamic conditions,an advanced control strategy based on an air-assisted volumetric UDS is presented.It covers the methods of flow compensation and switching working conditions.The strategy is authenticated on an UDS and tested in different dynamic conditions.The result shows that the control strategy discussed results in higher dynamic accuracy and faster dynamic response speed of UDS.The inject deviation range is improved from being between-8%and 10%to-4%and 2%and became more stable than before,and the dynamic response time was shortened from 200 ms to 150 ms.The ETC cycle result shows that after using the new strategy the NH_3 emission is reduced by 60%,and the NO_χemission remains almost unchanged.The trade-off between NO_χconversion efficiency and NH_3 slip is mitigated.The studied flow compensation and switching working conditions can improve the dynamic performance of the UDS significantly and make the UDS dynamic response keep up with the changes of the engine's operating conditions quickly.
文摘The principle and working process of Vacuum Resin Shot Dosing Equipment(VRSDE) are analyzed and the characteristics of IP1612-220PLC (Programmable Logical Controller) areintroduced briefly at first. Then the authors discuss the flow of program, the assignment of PLCI/O ports, the wiring diagram, and the ladder logic program of the PLC control system of VRSDE indetail. Some application issues of the system are accounted for in addition. Finally, according tothe information acquired from users, the authors draw the conclusion: this system owns a highreliability and a-vailability and greatly improves the automatic degree of VRDE.
基金supported by the National Key R&D Program of China(No.2022YFC2402300)National Natural Science Foundation of China(No.12075330)。
文摘Ultrahigh-dose-rate radiotherapy(FLASH-RT)is a revolutionary radiotherapy technology that can spare normal tissues without compromising tumor control.Although qualitative experimental results have been reported,quantitative and systematic analysis of data is necessary.Particularly,the FLASH effect response model to the dose or dose rate is still unclear.This study investigated the relationships between the FLASH effect and experimental parameters,such as dose,dose rate,and other factors by analyzing published in vivo experimental data from animal models.The data were modeled based on logistic regression analysis using the sigmoid function.The model was evaluated using prediction accuracy,receiver operating characteristic(ROC)curve,and area under the ROC curve.Results showed that the FLASH effect was closely related to the dose,mean dose rate,tissue type,and corresponding biological endpoints.The dose rate corresponding to a 50% probability of triggering cognitive protection in the brain was 45 Gy s^(-1).The dose rate corresponding to a 50% probability of triggering intestinal crypt survival and regeneration was 140 Gy s^(-1).For the skin toxicity effect,the dose corresponding to a 50% probability of triggering the FLASH effect was 24 Gy.This study helps to characterize the conditions underlying the FLASH effect and provides important information for optimizing experiments.
文摘On the basis of the analysis of faults and their causes of vacuum resin shot dosing equipment, the fuzzy model of fault diagnosis for the equipment is constructed, and the fuzzy relationship matrix, the symptom fuzzy vector, the fuzzy compound arithmetic operator, and the diagnosis principle of the model are determined. Then the fault auto-diagnosis system for the equipment is designed , and the functions for real-time monitoring its operation condition and for fault auto diagosis are realized. Finally, the experiments of fault auto-diagnosis are conducted in practical production and the veracity of the system is verified.
文摘In this editorial I comment on the article,published in the current issue of the World Journal of Clinical Oncology.Primary central nervous system lymphoma(PCNSL)is a disease of elderly and immunocompromised patients.The authors reported clinical results of 19 patients with PCNSL treated with zanubrutinib/high dose methotrexate(HD-MTX)until disease progression.They demonstrated that the combination of zanubrutinib with HD-MTX led to a marked clinical response and tolerability among these patients.They also observed that cerebrospinal fluid liquid biopsy to detect circulating tumor DNA may be a good option for evaluating treatment response and tumor burden in patients with PCNSL.PCNSL is a challenging disease for treatment as these patients present with different neurological states and comorbidities.Treatment has evolved over the years from whole brain radiotherapy to HD-MTX followed by autologous stem cell transplant.Gradually,treatment of patients with PCNSL is going to become individualized.
文摘AIM: To compare(using the Ottawa Bowel Preparation Scale) the efficacy of split-dose vs morning administration of polyethylene glycol solution for colon cleansing in patients undergoing colonoscopy, and to assess the optimal preparation-to-colonoscopy interval.METHODS: Single-centre, prospective, randomized, investigator-blind stud in an academic tertiarycare centre. Two hundred patients requiring elective colonoscopy were assigned to receive one of the two preparation regimens(split vs morning) prior to colonoscopy. Main outcome measurements were bowel preparation quality and patient tolerability.RESULTS: Split-dose regimen resulted in better bowel preparation compared to morning regimen [Ottawascore mean 5.52(SD 1.23) vs 6.02(1.34); P = 0.017]. On subgroup analysis, for afternoon procedures, both the preparations were equally effective(P = 0.756). There was no difference in tolerability and compliance between the two regimens.CONCLUSION: Overall, previous evening- same morning split-dosing regimen results in better bowel cleansing for colonoscopy compared to morning preparation. For afternoon procedures, both schedules are equally effective; morning preparation may be more convenient to the patient.
文摘The paper presents a computer code system 'SRDAAR- QNPP' for the real-time dose as-sessment of an accident release for Qinshan Nuclear Power Plant. It includes three parts:thereal-time data acquisition system, assessment computer. and the assessment operating code system. InSRDAAR-QNPP, the wind field of the surface and the lower levels are determined hourly by using amass consistent three-dimension diasnosis model with the topographic following coordinate system.A Lagrangin Puff model under changing meteorological condition is adopted for atmosphericdispersion, the correction for dry and wet depositions. physical decay and partial plume penetrationof the top inversion and the deviation of plume axis caused by complex terrain have been taken in-to account. The calculation domain areas include three square grid areas with the sideline 10 km, 40krn and 160 km and a grid interval 0.5 km, 2.0 km, 8.0 km respectively. Three exposure pathwaysare taken into account:the external exposure from immersion cloud and passing puff, the internalexposure from inhalation and the external exposure from contaminated ground. This system is ableto provide the results of concentration and dose distributions within 10 minutes after the data havebeen inputed.
基金supported by the Special Fund for Public Welfare Industry of Ministry of Water Resources of China(Grant No.200801001)National Science and Technology Major Projects of China(Grant No.2012ZX07506003-4)Central Public-interest Scientific Institution Basal Research Fund(Grants No.Y110002 and Y110005)
文摘Restraining algal growth by algaecide has been studied by many researchers, but the dosing time has not yet been studied. In this study, we examined the appropriate dosing time of algaecide through a series of experiments. In the experiments, the pH value of water is significantly affected by Microcystis aeruginosa, and the variation of the pH value is in favor of the growth of the alga. Therefore, using acid algaecide in the period with maximum pH values, i.e., the stable phase, would change the acidity-alkalinity of the water significantly, and would negatively affect algal growth. Acid algaecide does not eliminate the alga effectively if the acid algaecide is dosed in the logarithmic growth phase. Using acid algaecide in the decline phase after algal bloom not only is unfavorable for eliminating the alga, but also prolongs the decline phase, and even brings about next larger algal bloom.
基金supported by the International Fusion Reactor Experiment Program(No.2014GB112004)
文摘Optically stimulated luminescence(OSL) reading systems are becoming smaller and capable of real-time detection. To improve real-time and multipurpose radiation dosimetry readings, we built a real-time continuous-wave(RCW) OSL reading system. This system is both small and lightweight, and it employs powerful laser excitation(478 mW/cm^2) at the dosimetry probe location. We investigate the possibility of using the RCW mode to read the radiation luminescence(RL) or OSL by using a singlecrystal Al_2O_3:C dosimeter in a low-dose-rate137 Cs y field.Our results indicate that the RL/OSL follows a stable and uniform distribution. The minimum detected doses associated with the RL, OSL, and RL + OSL signals are2.1 9 10^(-2), 3.17 9 10^(-1), and 5.7 9 10^(-2) l Gy, respectively. This device provides a framework for the future development of applications for practical radiation dose measurements.
文摘AIM To determine the preventive effect and safetyof proton pump inhibitors (PPIs) in low-dose aspirin(LDA)-associated gastrointestinal (GI) ulcers andbleeding.METHODS: We searched MEDLINE, EMBASE and theCochrane Controlled Trials Register from inception toDecember 2013, and checked conference abstracts ofrandomized controlled trials (RCTs) on the effect ofPPIs in reducing adverse GI events (hemorrhage, ulcer,perforation, or obstruction) in patients taking LDA.The preventive effects of PPIs were compared with thecontrol group [taking placebo, a cytoprotective agent,or an H2 receptor antagonist (H2RA)] in LDA-associatedupper GI injuries. The meta-analysis was performedusing RevMan 5.1 software.RESULTS: We evaluated 8780 participants in 10 RCTs.The meta-analysis showed that PPIs decreased the riskof LDA-associated upper GI ulcers (OR = 0.16; 95%CI:0.12-0.23) and bleeding (OR = 0.27; 95%CI: 0.16-0.43)compared with control. For patients treated with dualanti-platelet therapy of LDA and clopidogrel, PPIs wereable to prevent the LDA-associated GI bleeding (OR =0.36; 95%CI: 0.15-0.87) without increasing the riskof major adverse cardiovascular events (MACE) (OR =1.00; 95%CI: 0.76-1.31). PPIs were superior to H2RAin prevention of LDA-associated GI ulcers (OR = 0.12;95%CI: 0.02-0.65) and bleeding (OR = 0.32; 95%CI:0.13-0.79).CONCLUSION: PPIs are effective in preventing LDAassociatedupper GI ulcers and bleeding. Concomitantuse of PPI, LDA and clopidogrel did not increase therisk of MACE.
基金Supported by the National Natural Science Foundation of China(51478314,51638011)the National Key Project for Research and Development Program of China(2016YFC0400503)+1 种基金the Natural Science Foundation of Tianjin(14JCQNJC09000)Science and Technology Research Projects of Colleges and Universities of Hebei Province(QN2015122)
文摘The effects of potassium permanganate(KMnO_4)dosing position on the natural organic matter(NOM)removal as well as membrane fouling were investigated in the coagulation/ultrafiltration combined process.KMnO_4 oxidation altered the NOM characteristics in terms of hydrophobicity and molecular weight,and destroyed humic substances originated from terraneous organisms in raw water.The optimal KMnO_4 dosage was 0.5 mg·L^(-1) in the peroxidation enhanced coagulation process with respect to the dissolved organic carbon(DOC)removal.When KMnO_4 was dosed into both upstream and downstream of coagulation,namely in the proposed twoposition dosing mode,coagulation and KMnO_4 oxidation worked individually on the apparent DOC removal.However,compared to the KMnO_4 addition prior to or after coagulation,the two-position dosing mode dramatically alleviated membrane fouling and reduced fouling irreversibility.This was attributed to the change of NOM characteristics as a result of KMnO_4 addition prior to coagulation and the presence of MnO_2 on membrane surface as a result of KMnO_4 addition prior to ultrafiltration.This work may provide useful information for the application of KMnO_4 oxidation in the coagulation/ultrafiltration combined system.
文摘Dose in radiation therapy has been reported as the water-equivalent dose using conventional dose calculation algorithms. The Monte Carlo (MC) algorithm employs characterization of human tissues by elemental composition and mass density. It enables more accurate dose calculation for radiation therapy treatment planning and typically reports absorbed dose to medium. Whether one should use dose to medium or tissue (Dm) in place of dose to water (Dw) for MC treatment planning remains the subject of debate. The aim of the current study is to evaluate the differences between dose-volume indices for Dm and Dw MC-calculated IMRT plans. Thirty-seven spine patients were selected for this study. The IMRT optimization and MC calculations were performed using the iPlan RT DoseTM ver 4.1.2 (Brainlab, Munich, Germany) treatment planning system (TPS) with an X-ray Voxel Monte Carlo (XVMC) dose calculation engine. Dw and Dm results for target and critical structures were evaluated using the dose-volume-based indices. Systematic differences between dose-volume indices computed with Dw and Dm were up to 5.2%, 4.2%, and 4.5% for D2, D50 and D98 indices of the clinical target volume (CTV), respectively and up to 1% for the critical structure dose indices. Our study demonstrates that employing Dm in place of Dw in MC-calculated IMRT treatment plans introduces a significant systematic difference in target DVHs. We recommend that for diffused target structures (such as spine tumors), dose to water is a better quantity for dose prescription in photon beam treatment planning using existing MC TPS. While for critical structures, it would be reasonable to report Dm always. However in future with the availability of finer spatial resolution, Dm will be the most suitable variable for both target and critical structures’ dose prescription and reporting in MC treatment planning.
文摘Background: Magnetic resonance image-guided radiation therapy (MR-IGRT) promises more precise and effective radiation treatments compared to conventional IGRT by using real-time on-board MR imaging. Under the influence of a magnetic field, however, secondary electrons exiting a surface can be forced in a circular path and re-enter the medium, resulting in dose increase at a beam-exit surface, called the electron return effect (ERE). The purpose of the study is to compare the exit skin dose computed by Monte Carlo dose calculation with measurements using an adult anthropomorphic phantom and to measure the effect of skin dose reduction by adding 1 cm-thick bolus. Method: The plan was compared with measurements using an adult anthropomorphic phantom combined with radiochromic films and thermoluminescent dosimeters. We also measured the skin dose reduction by adding 1 cm-thick bolus on the frontal surface of the phantom. Results: We found that 1 cm-thick bolus reduced the skin dose by up to 20% both in measurements and calculations. The plan was found to overestimate the measured skin dose by about 10% and there was no significant difference in the bolus effect between the breast skin and the skin (without breast attachment) doses. Conclusion: In conclusion, we confirmed the ERE effect on the anthropomorphic phantom under the magnetic field and the exit skin dose reduction by adding a bolus. Skin dose measurements using anthropomorphic phantom may be helpful to evaluate more realistic skin dose and the bolus effect in the magnetic field.
文摘Faults of vacuum resin shot dosing equipment are studied systematically and the fault tree of the system is constructed by using the fault tree analysis(FTA) method. Then the qualitative and quantitative analysis of the tree is carried out, respectively, and according to the results of the analysis, the measures to improve the system are worked out and implemented. As a result, the reliability of the equipment is enhanced greatly.
文摘BACKGROUND:The study aimed to determine the frequency of enoxaparin dosing errors for patients who had a measured emergency department(ED)weight compared to those who did not have a measured ED weight,and to determine if demographic variables(e.g.,weight,height,age,Englishspeaking,race)impact the likelihood of receiving an inappropriate dose.METHODS:This is a retrospective,electronic chart review of patients who received a dose of enoxaparin in the ED between January 1,2008 and July 1,2013.We identified all patients>18 years who received a dose of enoxaparin while in the ED,were admitted,and had at least one inpatient weight within the first four days of hospitalization.Patients were excluded if they received enoxaparin for prophylaxis or a dose of more than 1.25mg/kg.RESULTS:A total of 1,944 patients were included.Patients were more likely to experience an error if they did not have a measured ED weight.Over-doses of>10mg were more likely to occur in patients without a measured ED weight.Patients with no documented ED weight or with a staffestimated ED weight were more likely to experience a dosing error than those with a patient-stated weight.Patients were more likely to experience an error if their first inpatient weight was more than 96kg,they were more than 175-cm tall,or were English speaking.CONCLUSION:Dosing errors are more likely to occur when patients are not weighed in the ED.Modifications to current workflows to incorporate weighing those patients who receive weightdosed medications may be warranted.
文摘While the incidence of toddlers’ diabetes is soaring,their mainstay insulins were withdrawn,namely the weak 10% or 20% insulin mixtures (WIM),which were injected only once or twice daily.Consequently,toddlers are coerced to use an insulin pump,multi-dose insulin regime (MuDIR),mix or dilute insulins.This paper highlights the difficulties and proposes a simple solution.While an insulin pump is the best available option,it is not readily available for everyone.Mixing insulins is not sufficiently precise in small doses.Although diluting insulin would allow precise dosing and reduce the dose variability secondary to dribbling after injections,it,like insulin mixing,deprives children from using the pen and related child-friendly accessories.In MuDIR,we inject 4-5 small doses of insulin instead of 1-2 daily larger doses of WIM.Thus,on using a half unit (unit) insulin pen,a dose of 0.5,1,1.5 and 2 units are adjusted in steps of 100%,50%,33% or 25%;unlike the advisable 5%-20%.This does not easily match the tiny erratic meals of grazing toddlers.Maternal anxiety peaks on watching yo-yoing glycemia.Carers have to accept either persistently high sugar or wild fluctuation.The risks of such poor glycemic pattern are increasingly recognized.Using insulin U20 in a unit disposable pen allows deci-unit dosing,with 5%-20% dose-tuning,greater accuracy on delivering small doses and reduction of dose variability from dribbling.Deci-unit dosing may help avoid wide glycemic swings and provide the affordable alternative to insulin pumps for toddlers.Deci-unit pen materializes the Human Rights of Children,a safer and effective treatment.
文摘A front-end electronics of dose monitor has been developed for measuring irradiation dose to the patient in Shanghai Advanced Proton Therapy Facility.The parallel plate ionization chamber is used for the dose monitoring.Unlike the traditional method of recycling capacitor integration and voltage-to-frequency conversion,this dose monitor electronics uses the trans-impedance amplifier and analog-to-digital conversion method.It performs satisfactorily,with the integral nonlinearity of less than ±0.04 nA in the range of-400 to 50 nA and the resolution of about±0.6 nA.
文摘In view of the wide use of plants as test systems theeffects of acute and chronic exposure were comparedon seeds of Pisum sativum and in meristematic cellsof Allium sativum root tips.The two salts comparedwere zirconium oxychloride and known to be ubiquitousin plant systems and thallium acetate known for toxiceffects in high doses.Seeds were soaked in
文摘AIM To compare the efficacy of fixed-time split dose and split dose of an oral sodium picosulfate for bowel preparation.METHODS This is study was prospective, randomized controlled study performed at a single Institution(2013-058). A total of 204 subjects were assigned to receive one of two sodium picosulfate regimens(i.e., fixed-time split or split) prior to colonoscopy. Main outcome measurements were bowel preparation quality and subject tolerability.RESULTS There was no statistical difference between the fixedtime split dose regimen group and the split dose regimen group(Ottawa score mean 2.57 ± 1.91 vs 2.80 ± 2.51, P = 0.457). Cecal intubation time and physician's satisfaction of inspection were not significantly different between the two groups(P = 0.428, P = 0.489). On subgroup analysis, for afternoon procedures, the fixed-time split dose regimen was equally effective as compared with the split dose regimen(Ottawa score mean 2.56 ± 1.78 vs 2.59 ± 2.27, P = 0.932). There was no difference in tolerability or compliance between the two groups. Nausea was 21.2% in the fixed-time split dose group and 14.3% in the split dose group(P = 0.136). Vomiting was 7.1% and 2.9%(P = 0.164), abdominal discomfort 7.1% and 4.8%(P = 0.484), dizziness 1% and 4.8%(P = 0.113), cold sweating 1% and 0%(P = 0.302) and palpitation 0% and 1%(P = 0.330), respectively. Sleep disturbance was two(2%) patients in the fixed-time split dose group and zero(0%) patient in the split dose preparation(P = 0.143) group.CONCLUSION A fixed-time split dose regimen with sodium picosulfate is not inferior to a split dose regimen for bowel preparation and equally effective for afternoon colonoscopy.
文摘Background: Health worker shortages remain a significant challenge to delivery of health care services globally. Moving tasks, where appropriate, to less specialized health workers is recommended by the World Health Organization as a strategy to address this challenge. However, this concept is feared to raise specific quality concerns. This research aimed at assessing the performance of health workers to correctly prescribe (target) appropriate antimalarial treatment. Methods: We conducted a cross sectional study at three public health centre IVs in Uganda, with varying malaria transmission intensities (Kihihi-low, Kasambya-medium and Nagongera-high). We categorized prescribers into two groups: specialized prescribers (doctors and clinical officers) and less specialized prescribers (nurses and midwives). At each site, 100 records of patients seen between September and November 2011 and prescribed an antimalarial were retrieved for each group of prescribers. Correctness of the antimalarial drug prescribed and dose given were assessed for each group and compared to the 2005 Uganda national malaria treatment guidelines which recommend Artemether Lumefantrine (AL) for treatment of uncomplicated malaria and Quinine for complicated malaria. Results: Findings of the study showed that specialized health workers were more likely to target correctly as compared to the less specialized health workers [OR = 1.49 (1.00 - 2.22), p = 0.046]. Appropriateness of dosing was higher among specialized prescribers compared to less specialized prescribers however this was not significant [OR = 1.58 (0.77 - 3.25), p = 0.206]. Age of the participants, history of fever, diagnosis of malaria and prescription experience were not associated with correct targeting. Conclusion: This study shows that task shifting at the targeting level is not suitable;however, there is inadequate evidence to show that this also applies to anti-malarial dosing. Task shifting for the treatment of Malaria in Uganda should be investigated further using larger studies if it is to be considered as an option for solving the health worker shortages especially in regions with few specialized health workers but high malaria burden.