Mean Maximal Pressure Research Articles

Maximum home blood pressure is a useful indicator of diabetic nephropathy in patients with type 2 diabetes mellitus: KAMOGAWA-HBP study.

Maximum home systolic blood pressure has been shown to predict target organ damage. We aimed to clarify the association between maximum home systolic blood pressure and urine albumin to creatinine ratio, an indicator of early-phase diabetic nephropathy in patients with type 2 diabetes. In 1040 patients, we assessed the relationship of mean or maximum home systolic blood pressure and urine albumin to creatinine ratio, and compared the area under the receiver operating characteristic curve of mean or maximum home systolic blood pressure for diabetic nephropathy (urine albumin to creatinine ratio ⩾30 mg/g Cr). Multivariate linear regression analyses indicated that mean morning systolic blood pressure ( β = 0.010, p < 0.001) and maximum morning systolic blood pressure ( β = 0.008, p < 0.001) were significantly associated with urine albumin to creatinine ratio. Area under the receiver operating characteristic curve (95% confidence interval) for diabetic nephropathy in mean and maximum morning systolic blood pressure was 0.667 (0.634-0.700; p < 0.001) and 0.671 (0.638-0.703; p < 0.001), respectively. Maximum home systolic blood pressure, as well as mean home systolic blood pressure, was significantly associated with diabetic nephropathy in patients with type 2 diabetes.

Effects of flexible and rigid rocker profiles on in-shoe pressure

Rocker profiles are commonly used in the prevention of diabetic foot ulcers. Rockers are mostly stiffened to restrict toe plantarflexion to ensure proper offloading. It is also described that toe dorsiflexion should be restricted. However, the difference in effect on plantar pressure between rigid rockers that restrict this motion and flexible rockers that do not is unknown. In-shoe plantar pressure data were collected for a control shoe and the same shoe with rigid and flexible rockers with the apex positioned at 50% and 60%. For 29 healthy female adults peak plantar pressure (PP), maximum mean pressure (MMP) and force-time integral (FTI) were determined for seven regions of the foot. Generalized estimate equation was used to analyse the effect of the different shoes on the outcome measures for these regions. Compared to the control shoe a significant increase of PP and FTI was found at the first toe for both rigid rockers and the flexible rocker with the apex positioned at 60%, while MMP was significantly increased in rockers with an apex position of 60% (p<0.001). PP at the first toe was significantly lower in flexible rockers when compared to rigid rockers (p<0.001). For both central and lateral forefoot PP and MMP were significantly more reduced in rigid rockers (p<0.001), while for the medial forefoot no differences were found. The use of rigid rockers results in larger reductions of forefoot plantar pressures, but in worse increase of plantar pressures at the first toe compared to rockers that allow toe dorsiflexion.

Solutions for energy recovery of animal waste from leather industry

Secondary products from food and leather industries are regarded as animal wastes. Conversion of these animal wastes into fuels represents an energy recovery solution not only because of their good combustion properties, but also from the viewpoint of supply stability. A tannery factory usually processes 60–70t/month of crude leathers, resulting in 12–15t/month of waste. Fats, which can be used as the input fuel for diesel engines (in crude state or as biodiesel), represent 10% of this animal waste, while the rest are proteins that can be used to generate biogas through anaerobic digestion. Herein, we analyse two approaches to the use of animal waste from tanneries: as fuel for diesel engines and for biogas generation for heat production. Diesel fuelling and fuelling by animal wastes are compared in terms of the engine performance and pollutant emissions. The effects of animal waste usage on the pollutant emissions level, exhaust gas temperature, indicated mean effective pressure, maximum pressure, and engine efficiency are analysed. The energy recovery technologies for animal waste, which are analysed in this work, can be easily implemented and can simultaneously solve the problem posed by animal wastes by using them as an alternative to fossil fuels. Animal fats can be considered an excellent alternative fuel for diesel engines without major constructive modifications.

Effect of Laser Energy and Tip Insertion Depth on the Pressure Generated Outside the Apical Foramen During Er:YAG Laser-Activated Root Canal Irrigation.

The risk of extrusion of irritative irrigants into the extraradicular tissue should be minimized during root canal irrigation. This study aimed to examine the pressure generated outside the apex during Er:YAG laser-activated irrigation (LAI) in comparison with passive ultrasonic irrigation (PUI) and conventional syringe irrigation (SI). LAI is reported to be efficient for root canal debridement, whereas the apical pressure generated during LAI has not been investigated in detail. Plastic root canal models (apical diameter = 0.40 mm, taper = 6%, and length = 20 mm) were irrigated with water using either LAI with an Er:YAG laser (Erwin AdvEr; 30, 50, or 70 mJ, 10 pps), PUI, or SI. The tip insertion depth was set at 2, 5, or 10 mm from the apex. The pressure generated outside the apical foramen was measured with a pressure sensor connected to the apex of the model. When the tip was positioned at 2 mm and the power setting was changed, the mean maximum pressure values were LAI (30 mJ) = PUI < LAI (70 mJ) < SI (p < 0.05). When LAI was performed at 70 mJ and the tip was positioned at 5 or 10 mm, the pressure values were PUI < LAI = SI (p < 0.05). LAI generated similar or lower pressure outside the apical foramen compared with SI, irrespective of the laser energy and tip insertion depth examined. However, LAI generated higher pressure compared with PUI.

An Improved Rate of Heat Release Model for Modern High-Speed Diesel Engines

To meet the increasingly stringent emissions standards, diesel engines need to include more active technologies with their associated control systems. Hardware-in-the-loop (HiL) approaches are becoming popular where the engine system is represented as a real-time capable model to allow development of the controller hardware and software without the need for the real engine system. This paper focusses on the engine model required in such approaches. A number of semi-physical, zero-dimensional combustion modeling techniques are enhanced and combined into a complete model, these include—ignition delay, premixed and diffusion combustion and wall impingement. In addition, a fuel injection model was used to provide fuel injection rate from solenoid energizing signals. The model was parameterized using a small set of experimental data from an engine dynamometer test facility and validated against a complete data set covering the full engine speed and torque range. The model was shown to characterize the rate of heat release (RoHR) well over the engine speed and load range. Critically, the wall impingement model improved R2 value for maximum RoHR from 0.89 to 0.96. This was reflected in the model's ability to match both pilot and main combustion phasing, and peak heat release rates derived from measured data. The model predicted indicated mean effective pressure and maximum pressure with R2 values of 0.99 across the engine map. The worst prediction was for the angle of maximum pressure which had an R2 of 0.74. The results demonstrate the predictive ability of the model, with only a small set of empirical data for training—this is a key advantage over conventional methods. The fuel injection model yielded good results for predicted injection quantity (R2 = 0.99) and enabled the use of the RoHR model without the need for measured rate of injection.

Comparison of compressive forces caused by various cannulated cancellous screws used in arthroscopic ankle arthrodesis

BackgroundWhen performing arthroscopic ankle arthrodesis for end-stage ankle arthritis, internal fixation is performed using bone screws after appropriate preparation.However, optimal characteristics of bone screws have not been examined in terms of pressure force. Objective comparisons of bone-screw performance may provide information on procedures for arthroscopic ankle arthrodesis. The study objectives were to determine whether it was possible to measure compressive force changes using the newly developed device and to infer all screw characteristics from measurement results when used in actual surgeries. In addition, we performed experiments on cadavers to verify whether the experimental results could be applied to the joints of living subjects.MethodsThree types of screws (S1, S2, and S3) were inserted into the unique measurement device, and the changes in pressure were measured for each 45° turn. Changes in pressure and maximum pressure force were recorded after the application of the screws. After reaching the maximum pressure in the simulated bone, further screw rotations were accompanied by a gradual pressure decrease to 0 MPa. We also measured pressure changes in a similar manner by inserting a miniature pressure sensor into the talocrural joints of cadavers.ResultsThe mean maximum pressure ± standard deviation for S1, S2, and S3 were 0.832 ± 0.164 MPa, 0.434 ± 0.116 MPa, and 0.414 ± 0.127 MPa, respectively. Pressure slopes to the maximum did not significantly differ between the screws in the simulated bone, and a subsequent pressure decrease to 0 MPa was significantly more rapid for S1 than for S2 and S3. Although pressure failure after the overtightening of screws was only observed in the simulated bone, patterns of pressure vs. rotation angle were similar in simulated and cadaveric bones. The pressure profile characteristics of three different screw types were determined.ConclusionsWe were able to measure the compressive force changes using the newly developed device when the screws were inserted. On the basis of the measurement results, we were able to infer the characteristics of all screws when used in actual surgery.

Selection of peripheral intravenous catheters with 24-gauge side-holes versus those with 22-gauge end-hole for MDCT: A prospective randomized study

PurposeTo compare the 24-gauge side-holes catheter and conventional 22-gauge end-hole catheter in terms of safety, injection pressure, and contrast enhancement on multi-detector computed tomography (MDCT). Materials & methodsIn a randomized single-center study, 180 patients were randomized to either the 24-gauge side-holes catheter or the 22-gauge end-hole catheter groups. The primary endpoint was safety during intravenous administration of contrast material for MDCT, using a non-inferiority analysis (lower limit 95% CI greater than −10% non-inferiority margin for the group difference). The secondary endpoints were injection pressure and contrast enhancement. ResultsA total of 174 patients were analyzed for safety during intravenous contrast material administration for MDCT. The overall extravasation rate was 1.1% (2/174 patients); 1 (1.2%) minor episode occurred in the 24-gauge side-holes catheter group and 1 (1.1%) in the 22-gauge end-hole catheter group (difference: 0.1%, 95% CI: −3.17% to 3.28%, non-inferiority P=1). The mean maximum pressure was higher with the 24-gauge side-holes catheter than with the 22-gauge end-hole catheter (8.16±0.95kg/cm2 vs. 4.79±0.63kg/cm2, P<0.001). The mean contrast enhancement of the abdominal aorta, celiac artery, superior mesenteric artery, and pancreatic parenchyma in the two groups were not significantly different. ConclusionIn conclusion, our study showed that the 24-gauge side-holes catheter is safe and suitable for delivering iodine with a concentration of 300mg/mL at a flow-rate of 3mL/s, and it may contribute to the care of some patients, such as patients who have fragile and small veins. (Trial registration: UMIN000023727)

Different clinical outcomes in patients with asymptomatic severe aortic stenosis according to the stage classification: Does the aortic valve area matter?

BackgroundThe ACC/AHA guidelines introduced a new classification of severe aortic stenosis (AS) mainly based on maximum jet velocity (Vmax) and mean pressure gradient (mPG), but not on aortic valve area (AVA). However, prognostic value of this new classification has not yet been fully evaluated. Methods and resultsWe studied 1512 patients with asymptomatic severe AS enrolled in the CURRENT AS registry in whom surgery was not initially planned. Patients were divided into 2 groups: Group 1 (N=122) comprised patients who met the recommendation for surgery; high-gradient (HG)-AS (Vmax≥4.0m/s or mPG≥40mmHg) with ejection fraction (EF)<50%, or very HG-AS (Vmax≥5.0m/s or mPG≥60mmHg), and Group 2 (N=1390) comprised patients who did not meet this recommendation. Group 2 was further subdivided into HG-AS with preserved EF (HGpEF-AS, N=498) and low-gradient (LG)-AS, but AVA<1.0cm2 (N=892). The excess risk of Group 1 relative to Group 2 for the primary outcome measure (a composite of aortic valve-related death or heart failure hospitalization) was significant (adjusted HR: 1.92, 95%CI: 1.37–2.68, P<0.001). The excess risk of HGpEF-AS relative to LG-AS for the primary outcome measure was also significant (adjusted HR: 1.45, 95%CI: 1.11–1.89, P=0.006). Among LG-AS patients, patients with reduced EF (<50%) (LGrEF-AS, N=103) had extremely high cumulative 5-year incidence of all-cause death (85.5%). ConclusionTrans-aortic valve gradient in combination with EF was a good prognostic marker in patients with asymptomatic AS. However, patients with LGrEF-AS had extremely poor prognosis when managed conservatively.

Comparison of actual height and height estimated by using tibial length in an individual

Since 1987, 30 patients with bladder cancer underwent cystoprostatectomy with bladder replacement via ileocecourethrostomy. Multiple transverse teniamyotomies were made in the cecum to assure a large capacity reservoir with low pressures. The particular anatomy and physiology of the cecum, short length of the intestinal segment needed and teniamyotomies are the 3 factors that have allowed for good functional and metabolic results. All patients achieved daytime continence. After 3 years of followup 67% of the patients were continent at night if they voided every 3 or 4 hours and 22% if they voided every 2 or 3 hours, while 11% experienced enuresis. Urodynamic data after 1 year showed a mean capacity of 396 ml. for the new bladder, a mean full filling pressure of 28 cm. water and a mean maximum pressure of 55 cm. water. Post-micturition residual urine volume was consistently less than 55 ml. These results indicate that the ileocecal segment can be enlarged with myotomies through the tenia to produce an adequate capacity and a low pressure bladder replacement without the need for formal detubularization.

Mechanical Risk Factors for Stress Fracture in Elite Runners

Objectives:Bone stress injuries (BSI) are responsible for significant missed competition and training in distance runners. A recent review of our institution’s injury database revealed that one-fifth of NCAA-level runners sustained one or more BSI over a three-year period. While much is known about certain risk factors for stress injury such as the Female Athlete Triad, little is known about biomechanical risk factors including dynamic loading of the foot during running differs between athletes with history of BSI and those without. The aims of this study were: 1) characterize the dynamic loading patterns of elite distance runners during athletic movement, 2) determine the difference in dynamic loading magnitude and location in runners who have history of a BSI compared to non-injured runners and 3) establish a database to be used for follow-up evaluation. We hypothesized that athletes with a history of BSI in the lower extremity apply greater dynamic loads during athletic movements compared to uninjured athletes.Methods:We recruited 40 healthy varsity distance runners (16 females, 24 males) from our institution to participate in the study. Dynamic foot loading data was collected on all athletes using a validated wireless insole pressure measurement system during a series of athletic movements (e.g., walking, running and lateral cutting). Data was collected for contact area, maximum force, peak pressure, maximum mean pressure and force-time integral at each of eleven foot regions during each athletic movement. All force and pressure data were normalized to body weight. Injury history and other potential risk factors of interest were collected by self-report questionnaire and chart review. All BSI occurred as a result of participation of running, diagnosed by a physician and confirmed with advanced imaging. Mean values were calculated for each variable and foot region in each athlete and paired t-tests were performed for injury history comparisons.Results:A total of 23 runners with a history of 1 or more lower extremity BSI (11 females, 12 males), and 17 athletes with no history of BSI (5 females, 12 males) participated. Runners with a history of BSI trended toward greater peak pressures during running activities (p = .13) compared to uninjured controls, and displayed significantly greater peak pressures in the forefoot during cutting movements (p < .05). Further, those with history of BSI in the foot and ankle displayed greater force-time integral in the forefoot during running (p = .06). In the medial forefoot, athletes with history of BSI displayed significantly greater maximum mean pressures during jump takeoff (p < .05), running (p = .05) and cutting (p < .05). We did not observe a difference in foot strike patterns or FAAM Sport scores between injured and uninjured runners. Menstrual irregularities were seen in a majority of female athletes and were not associated with BSI.Conclusion:Our findings suggest that elite runners with a history of BSI exert greater pressures and force-time integral in the forefoot and medial midfoot during running and cutting compared to uninjured athletes. The greater loads in the forefoot and medial midfoot may play a role in the incidence and recurrence of BSI in running athletes. Further study of our athlete cohort will allow elucidation of specific high pressure points in the foot that may place athletes at risk for specific BSI, and allow us to investigate the utility of preventive measures.

Utility of balloon expulsion test in patients with constipation: Preliminary results in a single center

Summary Background Pelvic floor dyssynergia can be a cause of idiopathic constipation. Although pelvic floor dyssynergia can be diagnosed by rectal balloon expulsion (BE) and anorectal manometry, the utility of BE in the evaluation of constipation in clinical practice remains to be determined. To this end, we examined the role of BE among different body positions in Taiwanese people with constipation. Methods Fourteen Taiwanese adults (age range, 19–61 years), including six healthy volunteers (4 male, 2 female) and eight patients with chronic constipation (1 male, 7 female) underwent solid-state anorectal manometry and BE. The demographic data of all individuals were recorded at enrollment. Results Compared to healthy volunteers, patients with chronic constipation had a numerically lower threshold for mean resting pressure (p = 0.052), squeeze pressure, maximal squeeze pressure, and lower threshold volumes for urge, but higher threshold pressures for compliance. Successful BE seemed to be associated with lower mean resting pressure (p = 0.061), lower mean threshold volumes for urge, and higher mean maximal squeeze pressure for compliance. Although patients with chronic constipation had a numerically lower successful rate of rectal BE than healthy controls, the differences did not reach statistical significance. Conclusion In Taiwanese individuals, results of BE seems consistent with anorectal manometry parameters, and patients with chronic constipation have a trend of lower successful rate of rectal BE than healthy controls. However, future work to confirm the use of BE in differentiating subtypes of chronic constipation is needed.

DOPPLER ECHOCARDIOGRAPHIC FINDINGS IN TISSUE ENGINEERED AORTIC VALVE IN A SHEEP MODEL

Background: Heart valve diseases are considered a common disease in human and animals, and valve replacement is an option for treatment of valvular diseases. Objectives: In this study efficacy of a tissue engineered valve in thoracic aorta was evaluated with transthoracic echocardiography. Methods: This study was undertaken on 6 male sheep. Echocardiography was performed on all sheep 24 hours before surgery and repeated 24 hours (D1), 2 weeks (W2) and 4 weeks (W4) after surgery. Right parasternal long axis view of left ventricular outflow tract (LVOT) was used to assess hemodynamic across new valve. Results: Velocity time integral (VTI) significantly decreased from 18.98±2.88 before surgery to 12.55±2.48 one day after surgery (D1) (p<0.05). Mean Velocity (Vmean) decreased significantly from 52.56±12.01 to 39.72±12.30 at D1 (p<0.05). But maximum velocity (Vmax) was constant during study. There was not any statistical difference between mean Pressure gradient (Pgmean) or maximum pressure gradient (Pgmax) in comparison with pre-surgery and D1, W2 and W4. At D1, W2 and W4, time to peak (TTP) differed significantly from previous time. Conclusions: Our results demonstrated that this tissue engineered aortic valve (TEAV) could change some hemodynamic parameters, but heart could compensate some of them. Valve movement remained normal but the major complication was aneurism which seems to be the result of poor scaffold.

Effect of dilution strategies and direct injection ratios on stratified flame ignition (SFI) hybrid combustion in a PFI/DI gasoline engine

Three-dimensional (3-D) computational fluid dynamics (CFD) simulations were used to investigate and obtain a fundamental understanding of the effect of dilution strategies and direct injection ratios on the stratified flame ignition (SFI) hybrid combustion. The combination of port fuel injection (PFI) and direct injection (DI) was used to form the homogeneous lean/diluted mixture and stratified charge respectively. Studies were carried out on effects of dilution strategies with different combinations of fuel/air equivalence ratio (ϕair) and fuel/dilution equivalence ratio (ϕdilution) with negative valve overlap (NVO). Compared to the stoichiometric SFI hybrid combustion, the air-diluted SFI hybrid combustion optimizes the early flame propagation process because of the avoidance of over-rich mixture around spark plug. In order to explore the potential of SFI hybrid combustion under a high compression ratio (14:1) operation, the lean boosted dilution strategy with additional intake air and internal residual gas was proposed to address the trade-off between indicated mean effective pressure (IMEP) and maximum pressure rise rate (PRRmax) in air-diluted SFI hybrid combustion. Furthermore, the effect of direct injection ratio (rDI) was investigated as a means to optimize the fuel/air equivalence ratio distribution as well as the air-diluted SFI hybrid combustion performance. It is found that the optimal SFI hybrid combustion with rDI of 0.16 can be used to both achieve higher IMEP for a given amount of fuel and moderate the rate of heat release. Finally, three different combustion regimes, including pure flame propagation zone, hybrid combustion zone and pure auto-ignition zone, are proposed to understand the effect of typical fuel/air equivalence ratio distribution patterns on the air-diluted SFI hybrid combustion characteristics and performances. In order to obtain optimal hybrid combustion with high IMEP and low PRRmax, the in-cylinder stratified mixture should avoid over-rich condition around spark plug and over-lean condition at outer region. In addition, the internal residual gas in the dilution strategy should be carefully controlled to maintain sufficient thermal condition and ensure the stable auto-ignition of the lean mixture at outer region.

Analysis of Pulmonary Function Test in Korean Patients With Duchenne Muscular Dystrophy: Comparison of Foreign and Korean Reference Data.

ObjectiveTo determine the abnormal pulmonary function value in Korean Duchenne muscular dystrophy (DMD) patients, we performed a comparative analysis of the patients' pulmonary function value expressed as % of the overseas reference data and Korean healthy children and adolescent reference data.MethodsWe performed pulmonary function test (PFT) in a total of 27 DMD patients. We compared the patients' FVC% and FEV1% of the overseas reference data with those of the Korean children and adolescent reference data. Also, we compared the patients' MIP% and MEP% of the prediction equation data with those of the Korean children and adolescent reference data.ResultsAge of the subjects ranged from 8 to 16 years (12.03±2.27 years). The mean maximal expiratory pressure (MEP), maximal inspiratory pressure (MIP), vital capacity (VC), forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), and peak cough flow (PCF) were 36.93±9.5 cmH2O, 45.79±17.46 cmH2O, 1.4±0.43 L, 1.45±0.45 L, 1.40±0.41 L, and 206.25±61.21 L/min, respectively. The MIP%, MEP%, and FVC% of the Korean children and adolescent reference data showed statistically significant higher values than those of the prediction equation data.ConclusionWe observed a clear numeric difference between Korean DMD patients' pulmonary function value expressed as % of the overseas data and inland data. To perform a precise assessment of respiratory function and to determine appropriate respiratory therapy, pulmonary function values of Korean DMD patients should be interpreted taking into account the inland normal pulmonary function test data.

Investigation on combustion parameters of palm biodiesel operating with a diesel engine

Biodiesel is a renewable and decomposable fuel which is derived from edible and non-edible oils. It has different properties compared to conventional diesel but can be used directly in diesel engines. Different fuel properties characterise different combustion-phasing parameters such as cyclic variations of Indicated Mean Effective Pressure (IMEP) and maximum pressure (Pmax). In this study, cyclic variations of combustion parameters such as IMEP and Pmax were investigated using a multi-cylinder diesel engine operating with conventional diesel and palm biodiesel. The experiments were conducted using different engine loads; 20, 40, and 60% at a constant engine speed of 2500 rpm. The coefficient of variation (COV) and standard deviation of parameters were used to evaluate the cyclic variations of the combustion phasing parameters for the test fuels at specific engine test conditions. It was observed that palm biodiesel has lower COV IMEP compared to conventional diesel but is higher in COV Pmax at higher engine loads respectively. In addition, palm biodiesel tends to have a higher recurrence for the frequency distribution for maximum pressure. It can be concluded from the study that the fuel properties of palm biodiesel have influenced most of the combustion parameters.

Mitral stenosis and hypertrophic obstructive cardiomyopathy: An unusual combination

ObjectiveSystolic anterior motion of mitral valve (MV) leaflets is a main pathophysiologic feature of left ventricular outflow tract (LVOT) obstruction in hypertrophic obstructive cardiomyopathy. Thus, restricted leaflet motion that occurs with MV stenosis might be expected to minimize outflow tract obstruction related to systolic anterior motion. MethodsFrom January 1993 through February 2015, we performed MV replacement and septal myectomy in 12 patients with mitral stenosis and hypertrophic obstructive cardiomyopathy at Mayo Clinic Hospital in Rochester, Minn. Preoperative data, echocardiographic images, operative records, and postoperative outcomes were reviewed. ResultsMean (standard deviation) age was 70 (7.6) years. Preoperative mean (standard deviation) maximal LVOT pressure gradient was 75.0 (35.0) mm Hg; MV gradient was 13.7 (2.8) mm Hg. From echocardiographic images, 4 mechanisms of outflow tract obstruction were identified: systolic anterior motion without severe limitation in MV leaflet excursion, severe limitation in MV leaflet mobility with systolic anterior motion at the tip of the MV anterior leaflet, septal encroachment toward the LVOT, and MV displacement toward the LVOT by calcification. Mitral valve replacement and extended septal myectomy relieved outflow gradients in all patients, with no death or serious morbidity. ConclusionsPatients with mitral stenosis and hypertrophic obstructive cardiomyopathy have multiple LVOT obstruction mechanisms, and MV replacement may not be adequate treatment. We favor septal myectomy and MV replacement in this complex subset of hypertrophic obstructive cardiomyopathy.

Diesel–hydrogen dual-fuel combustion and its impact on unregulated gaseous emissions and particulate emissions under different engine loads and engine speeds

Experimental investigations were conducted on a diesel engine to evaluate the effects of hydrogen addition on engine combustion, unregulated gaseous emissions and particulate emissions based on the Japanese 13-mode testing cycle. A diesel–hydrogen co-operated combustion strategy is proposed in which hydrogen is naturally aspirated into the diesel engine to substitute 10, 20 and 30% of the total fuel energy at 10 selected modes and diesel is used as the sole fuel for the other 3 modes. Gradual increase of peak in-cylinder pressure and heat release rate is observed at medium and high engine loads. Pre-ignition might occur at high engine load and speed. Cyclic variation of the indicated mean effective pressure and maximum pressure derivative increased with hydrogen addition. The brake specific emissions of acetaldehyde (CH3CHO), alkenes (C2H4, C3H6 and C4H6), arenes (C6H6, C7H8 and C8H10) and particulate mass can be evidently reduced. However, with H30 operation, the weighted total HC and formaldehyde (HCHO) increased by around 27% and 8%, respectively, while NOx increased by around 17%. The simultaneous decrease of particle size and number are believed to be associated with the inhibition effect of hydrogen on soot particle formation based on the HACA (H2 abstraction and C2H2 addition) mechanism.

Etomidate is associated with longer seizure duration, lower stimulus intensity, and lower number of failed trials in electroconvulsive therapy compared with thiopental.

Induction agents used for electroconvulsive therapy (ECT) may alter seizure parameters. In this study, we aimed to investigate the effects of etomidate and thiopental on seizure-related variables. Registries of patients who received ECT between 2010 and 2013 in a tertiary psychiatry clinic were evaluated retrospectively. The information of patients who were on the same induction agent and muscle relaxant during the whole treatment course was assessed. Primary outcome measures were total number of ECT sessions, mean peripheral and central seizure duration, cumulative stimulus intensity, and the number of adequate seizures per total number of stimuli. Secondary measures were maximum systolic-diastolic and mean blood pressure, peak heart rate, and the frequency of antihypertensive drug use during the sessions. Although the total number of ECT sessions is similar between the etomidate (n = 43) and thiopenthal (n = 31) groups, the mean seizure duration per stimuli was significantly longer whereas the cumulative stimulus intensity was lower in the etomidate group. The number of adequate seizures obtained in relation with the number of stimuli was also significantly higher, indicating increased probability of eliciting an adequate seizure with etomidate. During threshold determination, the number of stimuli needed to provide an adequate seizure was marginally less with etomidate. No group difference was observed in hemodynamic changes and the frequency of antihypertensive use. Etomidate use, compared with thiopental as an induction agent, is associated with longer seizure duration with less cumulative intensity. The use of etomidate reduces the number of failed trials and may prevent the application of unnecessary electrical stimuli with a possibly safe hemodynamic profile.

Role of oxidative stress in surgical cavernous nerve injury in a rat model.

This study investigates the role of oxidative stress in surgical cavernous nerve (CN) injury in a rat model. Eighty-four male Sprague-Dawley rats were randomly divided into three groups: group 1, sham-operated rats; group 2, bilateral CN-crushed rats; and group 3, bilateral CN-transection-and-sutured-immediately rats. Oxidative stress was evaluated by malondialdehyde levels, super oxide dismutase (SOD) activities, and glutathione peroxidase (GPX) activities in serum. Erectile function was assessed by CN electrostimulation at 3 months with mean maximal intracavernous pressure (ICP) and maximal ICP per mean arterial pressure. Nerve injury was assessed by toluidine blue staining of CNs and nicotinamide adenine dinucleotide phosphate (NADPH)-diaphorase staining of penile tissue. GPX protein expression and nitrotyrosine-3 (NT-3) levels in penile tissue were measured. Erectile function and the number of myelinated axons of CNs and NADPH-diaphorase-positive nerve fibers were statistically decreased between groups, from sham to crush to transection. For markers, both nerve-injury groups showed increased oxidative stress markers at early time points, with the transection group showing greater oxidative stress than the crushed group and values normalizing to sham levels by week 12. GPX expression and NT-3 levels in penile tissue were in concordance with the results of SOD and GPX. These results show that oxidative stress plays an important role in injured CNs, and different methods of CN injury can lead to different degrees of oxidative stress in a rat model.

Completely intracorporeal robotic-assisted laparoscopic augmentation enterocystoplasty with continent catheterizable channel.

To report our results from series of robotic-assisted laparoscopic augmentation enterocystoplasty (RALAE) performed in a completely intracorporeal fashion. Patients who underwent RALAE with or without the creation of a catheterizable channel between 2006 and 2011 at the University of Texas, Houston and Northwestern Memorial Hospital were identified. Perioperative and follow-up data were analyzed. Preoperative and postoperative urodynamic data were analyzed when available. Twenty-two patients with neurogenic bladder underwent RALAE with or without the creation of a catheterizable channel. Fifteen patients underwent robotic augmentation enterocystoplasty alone, and 7 patients had creation of a catheterizable channel (4 Monti and 3 Mitrofanoff). There was 1 conversion to an open procedure in a patient undergoing concomitant creation of an appendicovesicostomy. Mean follow-up was 38.9 months (range, 6.2-72.1 months). Mean operative time was 365 minutes (range, 220-788 minutes); mean estimated blood loss was 110 mL (range, 30-250 mL). Median time to return of bowel function was 5 days (range, 2-17 days). Preoperative and postoperative urodynamic data were available for 13 patients. Mean cystometric capacity increased by 52%, and mean maximal bladder pressures decreased by 40. There were 5 minor complications (Clavien grade 1-2) and 4 major complications (Clavien grade 3-4). No patient experienced a wound infection. RALAE is a feasible approach that provides potential benefits over open bladder reconstruction in the neurogenic voiding dysfunction population.