ASYMPTOTIC STABILITY OF SHOCK WAVES FOR THE OUTFLOW PROBLEM OF A HEAT-CONDUCTIVE IDEAL GAS WITHOUT VISCOSITY

This paper is concerned with an ideal polytropic model of non-viscous and heatconductive gas in a one-dimensional half space. We focus our attention on the outflow problem when the flow velocity on the boundary is negative and we prove the stability of the viscous shock wave and its superposition with the boundary layer under some smallness conditions.Our waves occur in the subsonic area. The intrinsic properties of our system are more challenging in mathematical analysis, however, in the subsonic area, the lack of a boundary condition on the density provides us with a special manner for defining the shift for the viscous shock wave, and helps us to construct the asymptotic profiles successfully. New weighted energy estimates are introduced and the perturbations on the boundary are handled by some subtle estimates.

“I Dread the Heart Surgery but it Keeps My Child Alive”—Experiences of Parents of Children with Right Ventricular Outflow Tract Anomalies during the Assessment for Cardiac Reoperation

Background:Parents of children with complex right ventricular outflow tract(RVOT)anomalies are confronted with their child’s need for heart surgery early in life and repeated reoperations later on.Preoperative assessment needs to be performed whenever an indication for reoperation is suspected.The aim was to illuminate the experiences of parents of children diagnosed with RVOT anomalies,in particular,how they experience their child’s heart disease and everyday life during the assessment and after the decision on whether to perform a reoperation.Method:Individual interviews(n=27)were conducted with nine parents on three occasions between 2014 and 2016 and analyzed using reflexive thematic analysis.Results:The analysis resulted in the following five main coexisting themes:The heart surgery keeps my child alive illuminates parents’experiences during and after the assessment and emphasizes that heart surgery,although dreaded,is central for their child’s survival;Everyday struggles illuminates the different struggles parents had to face to ensure that their child would be in the best possible condition;the remaining three themes,Unconditional love,Trust in life,and Togetherness,illuminate the ways in which the parents gained inner strength and confidence in their everyday lives.Conclusion:Although the parents were grateful for the assessment and had learned to navigate among the fears it aroused,they experienced several distressing situations during the assessment process that should be addressed.By inviting both the parents and their child to participate in the child’s care,individualized support can take into account the needs of both parents and child.

Bipolar outflows as a repulsive gravitational phenomenon——Azimuthally Symmetric Theory of Gravitation(Ⅱ)

This paper is part of a series on the Azimuthally Symmetric Theory of Gravitation （ASTG）. This theory is built on Laplace-Poisson＇s well known equation and it has been shown that the ASTG is capable of explaining, from a purely classical physics standpoint, the precession of the perihelion of solar planets as a consequence of the azimuthal symmetry emerging from the spin of the Sun. This symmetry has and must have an influence on the emergent gravitational field. We show herein that the emergent equations from the ASTG, under some critical conditions determined by the spin, do possess repulsive gravitational fields in the polar regions of the gravitating body in question. This places the ASTG on an interesting pedestal to infer the origins of outflows as a repulsive gravitational phenomenon. Outflows are a ubiquitous phenomenon found in star forming systems and their true origin is a question yet to be settled. Given the current thinking on their origin, the direction that the present paper takes is nothing short of an asymptotic break from conventional wisdom; at the very least, it is a complete paradigm shift because gravitation is not at all associated with this process, but rather it is thought to be an all-attractive force that only tries to squash matter together onto a single point. Additionally, we show that the emergent Azimuthally Symmetric Gravitational Field from the ASTG strongly suggests a solution to the supposed Radiation Problem that is thought to be faced by massive stars in their process of formation. That is, at ,- 8-10M⊙, radiation from the nascent star is expected to halt the accretion of matter. We show that in-falling material will fall onto the equatorial disk and from there, this material will be channeled onto the forming star via the equatorial plane, thus accretion of mass continues well past the value of - 8-10M⊙, albeit via the disk. Along the equatorial plane, the net force （with the radiation force included） on any material there-on right up to the surface of the star is directed toward the forming star, hence accretion of mass by the nascent star is un-hampered.

Cross-sectional and longitudinal studies on interaction between bladder compliance and outflow obstruction in men with benign prostatic hyperplasia

Aim： To explore the interaction between bladder compliance （BC） and bladder outflow obstruction （BOO） in men with benign prostatic hyperplasia （BPH） using cross-sectional and longitudinal studies. Methods： A total of 181 men with BPH were recruited, and 100 of them were followed for one year. Cystometry was performed in a standing or a sitting position with 30 mL/min infusion. BC was manually corrected and defined. Obstruction coefficient （OCO）, linear passive urethral resistance relation and international continence society （ICS） nomogram were used to diagnose BOO. The obstructed parameters were compared between the reduced BC group and the non-reduced group. BC was compared between the first investigation at the beginning of study and the second investigation at the end of study during the one-year follow-up period. Results： The group with reduced BC had increased OCO and linear passive urethral resistance relation. BC was significantly lower in the obstructed group （55.7 mL/cm water） than that in unobstructed and equivocal one （74.9 mL/cm water, P 〈 0.01）. BC gradually reduced with the increased obstructed grade. There was a significantly weak negative correlation between BC and OCO （r = - 0.132, P 〈 0.01）. Over the one-year follow-up period in the longitudinal study, BC for all men changed from 54.4 to 48.8 mL/cm water （P 〉 0.05）, and BC for the group with BOO fell from 58.4 ± 70.1 to 46.5 ± 38.7 mL/cm water （P 〉 0.05）. Conclusion： In men with BPH, a significant systematic decrease occurred in BC in the obstructed group and a significant systematic increase with urethral resistance occurred in the low BC group. A longitudinal study of the tendency of BC reduction in a group with BOO is necessary in the future.

Effect of iron overload on electrophysiology of slow reaction autorhythmic cells of left ventricular outflow tract in guinea pigs

Objective: To investigate the electrophysiology effects and mechanism of iron overload on the slow response autorhythmic cells in the left ventricular outflow tract of guinea pigs.Methods: Standard microelectrode cell recording techniques were adopted to observe the electrophysiological effects of different concentrations of Fe^(2+)(100 μmol/L, 200 μmol/L) on the left ventricular outflow tract autorhythmic cells.Heart tissues were perfused with FeSO_4(200 μmol/L) combing with CaCl_2(4.2 mmol/L), Verapamil,(1 μmol/L), and nickel chloride(200μmol/L) respectively to observe the influences of these contents on electrophysiology of FeSO_4(200μmol/L) on the left ventricular outflow tract autorhythmic cells.Results: Fe^(2+)at both 100 μmol/L and 200 μmol/L could change the electrophysiological parameters of the slow response autorhythmic cells of the left ventricular outflow tract in a concentrationdependent manner resulting into decrease in Vmax, APA and MDP, slower RPF and VDD, and prolonged APD_(50) and APD_(90)(P all <0.05).Besides, perfusion of increased Ca^(2+) concentration could partially offset the electrophysiological effects of Fe^(2+)(200 μmol/L).The L-type calcium channel(LTCC) blocker Verapamil(1 μmol/L) could block the electrophysiological effects of Fe^(2+)(200 μmol/L).But the T-type calcium channel(TTCC) blocker nickel chloride(NiCl_2, 200 μmol/L) could not block the electrophysiological effects of Fe^(2+)(200 μmol/L).Conclusions: Fe^(2+) can directly change the electrophysiological characteristics of the slow response autorhythmic cells of the left ventricular outflow tract probably through the L-type calcium channel.

Electrophysiological changes of autonomic cells in left ventricular outflow tract in guinea pigs with iron deficiency anemia complicated with chronic heart failure

Objective: To investigate the electrophysiological changes of autonomic cells in left ventricular outflow tract in guinea pigs with iron deficiency anemia complicated with chronic heart failure.Methods: Guinea pigs model of iron deficiency anemia complicated with chronic heart failure in 10 guinea pigs of the experimental group was made by feeding a low iron diet,pure water and subcutaneous injection of isoproterenol. The control group consisting of 11 guinea pigs was given normal food, normal water and injected with normal saline. The left ventricular outflow tract model specimen was also prepared. The standard microelectrode technique was used to observe electrophysiological changes of autonomic cells in the outflow tract of left ventricular heart failure complicated with iron deficiency anemia in guinea pig model. The indicators of observation were maximal diastolic potential, action potential amplitude, 0 phase maximal depolarization velocity, 4 phase automatic depolarization velocity, repolarization 50% and 90%, and spontaneous discharge frequency.Results: Compared with the control group, 4 phase automatic depolarization velocity,spontaneous discharge frequency and 0 phase maximal depolarization velocity decreased significantly(P < 0.01) and action potential amplitude reduced(P < 0.01) in model group. Moreover, repolarization 50% and 90% increased(P < 0.01).Conclusions: There are electrophysiological abnormalities of the left ventricular outflow tract in guinea pigs with iron deficiency anemia complicated with heart failure.

THE STABILITY OF STATIONARY SOLUTION FOR OUTFLOW PROBLEM ON THE NAVIER-STOKES-POISSON SYSTEM

In this article, we are concerned with the stability of stationary solution for outflow problem on the Navier-Stokes-Poisson system. We obtain the unique existence and the asymptotic stability of stationary solution. Moreover, the convergence rate of solution towards stationary solution is obtained. Precisely, if an initial perturbation decays with the algebraic or the exponential rate in space, the solution converges to the corresponding stationary solution as time tends to infinity with the algebraic or the exponential rate in time. The proof is based on the weighted energy method by taking into account the effect of the self-consistent electric field on the viscous compressible fluid.

Balloon dilatation for treatment of hepatic venous outflow obstruction following pediatric liver transplantation

AIM To assess the efficacy and safety of balloon dilatation for the treatment of hepatic venous outflow obstruction(HVOO) following pediatric liver transplantation.METHODS A total of 246 pediatric patients underwent liver transplantation at our hospital between June 2013 and September 2016. Among these patients, five were ultimately diagnosed with HVOO. Seven procedures(two patients underwent two balloon dilatation procedures) were included in this analysis. The demographic data,types of donor and liver transplant, interventional examination and therapeutic outcomes of these five children were analyzed. The median interval time between pediatric liver transplantation and balloon dilatation procedures was 9.8 mo(range: 1-32).RESULTS Five children with HVOO were successfully treated by balloon angioplasty without stent placement, with seven procedures performed for six stenotic lesions. All children underwent successful percutaneous intervention. Among these five patients, four were treated by single balloon angioplasty, and these patients did not develop recurrent stenosis. In seven episodes of balloon angioplasty across the stenosis, the pressure gradient was 12.0 ± 8.8 mm Hg before balloon dilatation and 1.1 ± 1.5 mm Hg after the procedures, which revealed a statistically significant reduction(P < 0.05). The overall technical success rate among these seven procedures was 100%(7/7), and clinical success was achieved in all five patients(100%). The patients were followed for 4-33 mo(median: 15 mo). No significant procedural complications or procedurerelated deaths occurred.CONCLUSION Balloon dilatation is an effective and safe therapeutic option for HVOO in children undergoing pediatric liver transplantation. Venous angioplasty is also recommended in cases with recurrent HVOO.

Right Ventricular Outflow Tract Septal Pacing versus Apical Pacing: A Prospective, Randomized, Single-blind 5-Years Follow-up Study of Ventricular Lead Performance and Safety

Summary： Lead placement for ventricular pacing variably impacts the physiological benefit of the pa- tient. This study evaluated the ventricular lead performance and safety of right ventricular outflow tract septal pacing in patients with bradyarrhythmia in South China over 60-month follow-up. Totally, 192 patients （108 males, and 84 females, 63-4-21 years old） with bradyarrhythmia were randomly divided into two groups. The right ventricular outflow tract septum （RVOTs） group had lead placement near the sep- tum （n=97）, while the right ventricular apex （RVA） group had a traditional apical placement （n=95）. RV septal lead positioning was achieved with a specialized stylet and confirmed using fluoroscopic projec- tion. All patients were followed up for 60 months. Follow-up assessment included stimulation threshold, R-wave sensing, lead impedance and lead complications. The time of electrode implantation in both the ROVTs and RVA groups were significantly different （4.29±0.61 vs. 2.16±0.22 min; P=0.009）. No dif- ferences were identified in threshold, impedance or R-wave sensing between the two groups at 1 st, 12th, 36th and 60th month during the follow-up period. No occurrence of electrode displacement, increased pacing threshold or inadequate sensing was found. The long-term active fixation ventricular electrode performance in RVOTs group was similar to that in RVA group. RVOTs pacing near the septum using active fixation electrodes may provide stability during long-term follow-up period.

Esophagogastric junction outflow obstruction: Where are we now in diagnosis and management?

Esophagogastric junction outflow obstruction(EGJOO) is a major motility disorder based on the Chicago Classification of esophageal motility disorders.This entity involves a heterogenous group of underlying etiologies. The diagnosis is reached by performing high-resolution manometry. This reveals evidence of obstruction at the esophagogastric junction, manifested by an elevated integrated relaxation pressure(IRP) above a cutoff value(IRP threshold varies by the manometric technology and catheter used), with preserved peristalsis. Further tests like endoscopy, timed barium esophagram, and cross-sectional imaging can help further elucidate the underlying etiology and rule out mechanical causes.Treatment is tailored to the underlying cause. Similar to achalasia, treatment targeting lower esophageal sphincter disruption like pneumatic dilation, peroral endoscopic myotomy, and botulinum injection are used in patients with functional EGJOO and persistent symptoms.

Modified hepatic outflow tract reconstruction in piggyback liver transplantation

OBJECTIVE: To summarize the experience in modified reconstruction of the hepatic outflow tract during piggyback liver transplantation at our hospital. METHODS: The clinical data on 67 patients undergoing piggyback liver transplantation with modified hepatic outflow tract reconstruction from January 1999 to October 2002 were analyzed retrospectively. RESULTS: In this group, 7 patients (10. 45%) died perioperatively. Complications included: pulmonary infection (38 patients); multiple organ system failure (10), intraperitoneal bleeding (6), acute respiratory distress syndrome (14), thrombosis of the hepatie artery (1), and bile leakage (1). No hepatic outflow occluded. Two recipients survived for over 3 years, 8 over 2 years, and 19 over a year. CONCLUSION: Modified hepatic outflow reconstruction in piggyback live transplantation may increase the success rate of liver transplantation and decrease technical complications.

Tailoring the area of hepatic resection using inflow and outflow modulation

The performance of hepatic surgery without a parenchyma-sparing strategy carries significant risks for patient survival because of the not negligible occurrence of postoperative liver failure.The key factor of modern hepatic surgery is the use of the intraoperative ultrasound(IOUS),not only to stage the disease,but more importantly to guide resection with the specific aim to maximize the sparing of the functional parenchyma.Whether in patients with hepatocellular carcinoma and underlying liver cirrhosis,or in patients with colorectal liver metastasis,IOUS allows the performance of the so-called "radical but conservative surgery",which is the pivotal factor to offer a chance of cure to an increasing proportion of patients,who until few years ago were considered only for palliative care.Using some new IOUS-guided surgical maneuvers,which are based on the liver inflow and outflow modulations,more precise anatomically subsegmental-and segmentaloriented resections can be effectively performed.The present work describes the rationale and the surgical technique for a precise tailoring of the area of hepatic resection using the most recent attainments in IOUS.Such important technical achievements should be a fundamental part of the surgical armamentarium of the modern liver surgeon.

Esophagogastric junction outflow obstruction successfully treated with laparoscopic Heller myotomy and Dor fundoplication: First case report in the literature

BACKGROUND Esophagogastric junction outflow obstruction(EGJOO) is a rare syndrome,characterized by an elevation of the integrated relaxation pressure of the lower esophageal sphincter, not accompanied by alterations in esophageal motility that may lead to the criteria for achalasia. We were unable to find any prior report of the combination of Heller myotomy with anterior partial fundoplication(Dor) as the treatment for EGJOO. We herein report a case of EGJOO treated with laparoscopic Heller myotomy combined with Dor fundoplication.CASE SUMMARY A 26-year-old man presented with a 3-year history of solid dysphagia and a 30-kg weight loss. He was treated with oral nifedipine, isosorbide, and omeprazole,without resolution of symptoms. An upper gastrointestinal series(barium swallow) revealed a "bird's beak" sign. Esophagogastroduodenoscopy was positive for Los Angeles grade A peptic esophagitis. High-resolution esophageal manometry was compatible with EGJOO. Esophageal pH monitoring showed pathological acid reflux both in orthostatic and decubitus position. An 8-cm laparoscopic Heller myotomy combined with an anterior 220° Dor fundoplication was performed. Solid diet was introduced on postoperative day 2, and the patient was discharged home the same day. At 17-mo follow-up, he reported no symptoms. Barium swallow was compatible with complete radiologic resolution.Both esophageal manometry and upper endoscopy showed normal findings 9 mo after the operation.CONCLUSION Surgical treatment with Heller myotomy and Dor fundoplication is a potential treatment option for EGJOO refractory to medical treatment.

Venous outflow reconstruction in living donor liver transplantation:Dealing with venous anomalies

The reconstruction of the vascular outflow tract of partial liver grafts has received considerable attention in the past, especially in the setting of right liver grafts with undrained segments. Hepatic venous outflow reconstruction is an important factor for successful living donor liver transplantation outcome. However, in presence of undrained anterior sector and presence of multiple short hepatic veins that drain substantial portions of liver, outflow reconstruction without backtable venoplasty may lead to severe graft congestion and subsequent graft dysfunction. Various backtable venoplasty techniques in presence of multiple hepatic veins that can be used in either right- or leftlobe liver transplantation are devised to ensure a single, wide outflow channel. In this overview, various techniques to overcome the hepatic venous variations of liver allograft and outflow reconstruction are discussed.

A review of synoptic weather effects on sea ice outflow through Fram Strait: cyclone vs. anticyclone

Sea ice outflow through Fram Strait is a vital component of the sea ice mass balance of the Arctic Ocean.Previous studies have examined the role of large-scale modes of atmospheric circulation variability such as the Arctic Oscillation,North Atlantic Oscillation,and Dipole Anomaly in the movement of sea ice.This review emphasizes the distinct impacts of synoptic weather on sea ice export as well as on other relevant fields(i.e.,sea ice concentration and sea ice drift).We identify deficiencies in previous studies that should be addressed,and we summarize potential research subjects that should be investigated to further our understanding of the relationship between synoptic weather and sea ice export via Fram Strait.For example,the connection between summertime anticyclones and weakened potential vorticity related to the observed extensive spring Eurasian snow and Siberian Ocean sea ice loss is of considerable interest.In-depth exploration of this type of geophysical mechanism will be particularly useful in assessment of the robustness of such linkages inferred through statistical analyses.

Effects of Nonuniform Outflow and Buoyancy on Drag Coefficient Acting on a Spherical Particle

Pyrolysis gas jets out from the surface of a solid fuel particle when heated. This study experimentally observes the occurrence of gas jets?from heated solid fuel particles. Results reveal a local gas jet occurs from the particle’s surface when its temperature reaches the point at which a pyrolysis reaction occurs. To investigate the influence of the gas jet on particle motion, a numerical simulation of the uniform flow around a spherical particle with a nonuniform outflow or high surface temperature is conducted, and the drag force acting on the spherical particle is estimated. In the numerical study, the magnitude of the outflow velocity, direction of outflow, and Rayleigh number,?i.e., particle surface temperature, are altered, and outflow velocities and the Rayleigh number are set based on the experiment. The drag coefficient is found to decrease when an outflow occurs in the direction against the mainstream;this drag coefficient at a higher Rayleigh number is slightly higher than that at a Rayleigh number of zero.

Outflow of Pacific water from the Chukchi Sea to the Arctic Ocean

Pacific water exits the Chukchi Sea shelf through Barrow Canyon in the east and Herald Canyon in the west, forming an eastward-directed shelfbreak boundary current that flows into the Beaufort Sea. Here we summarize the transformation that the Pacific water undergoes in the two canyons, and describe the characteristics and variability of the resulting shelfbreak jet, using recently collected summertime hydrographic data and a year-long mooting data set. In both canyons the northward-flowing Pacific winter water switches from the western to the eastern flank of the canyon, interacting with the northward-flowing summer water. In Barrow canyon the vorticity structure of the current is altered, while in Herald canyon a new water mass mode is created. In both instances hydraulic effects are believed to be partly responsible for the observed changes. The shelfl）reak jet that forms from the canyon outflows has distinct seasonal configurations, from a bottom-intensified flow carrying cold, dense Pacific water in spring, to a surface-intensified current advecting warm, buoyant water in summer. The current also varies significantly on short timescales, from less than a day to a week. In fall and winter much of this mesoscale variability is driven by storm events, whose easterly winds reverse the current and cause upwelling. Different types of eddies are spawned from the current, which are characterized here using hydrographic and satellite data.

Effect of air core on the shape and discharge of the outflow through a bottom outlet

Experiments were conducted to study the generation of air core and its effect on the outflow shape and discharge in a cylindrical water tank with a bottom well-designed outlet. Depending on the stages of the air core in the tank, the outflow shape can vary from a smooth water jet to a smooth spindle shape with air-core, and to water sprays. The diameter of the nozzle size also has influence on the outflow pattern. The existence of the penetrated air core can dramatically reduce the outflow discharge, with the discharge coefficient decreasing with the nozzle diameter.

How does stiffness of trabecular meshwork affect outflow resistance in human eyes?

Purpose Ocular hypertension is the primary risk factor for development of glaucoma and the only modifiable endpoint[1,2].Clinical trials involving thousands of patients have shown consistently that lowering intraocular pressure（IOP）in those with glaucoma,whether or not their IOP is above normal,slows vision loss.IOP elevation is the result of diminished outflow facility in the conventional outflow pathway;and the highest resistance to aqueous humor outflow resides in the juxtacanalicular tissue（JCT）layer of trabecular meshwork（TM）and the inner wall of Schlemm’s canal（SC）.However,mechanisms of outflow facility decrease in glaucomatous eyes remain to be determined.

An Inexpensive and Simple Experimental Approach for the Estimation of Solute Import into Groundwater and Subsequent Export Using Inflow/Outflow Data

In agricultural catchments where groundwater (GW) base flow discharge contributes substantially towards stream flow, the information linking GW inflow/outflow with contaminant import/export is scarce. However, this information is essential to address aquatic ecosystem health hazard/risk associated with nitrate export and subsequent loading in sensitive surface water bodies (SWB). The objectives of this study were to assess the temporal dynamics of (i) rain water inflow/outflow behaviour in three agricultural catchments in the humid tropics of far-northeast Queensland of Australia, (ii) solute import via inflow and subsequent export in outflow, and (iii) the association between GW inflow/outflow and solute import/export. Approximately 71% of the average seasonal rainfall percolated (inflow) into the porous basaltic regolith of the Johnstone River Catchment (JRC) compared with 44% into the alluvial regolith in the Mulgrave River Catchment (MRC) and 29% into the metamorphic regolith in the Tully River Catchment (TRC), respectively. The outflows from the basaltic, alluvial, and metamorphic regoliths were 56%, 36%, and 55% of the inflows, respectively. The cumulative nitrate import per season was 25 k/ha in the JRC compared with 11 kg/ha in MRC and 34 kg/ha in TRC. The corresponding exports were 24 kg/ha, 8 kg/ha 26 kg/ha in JRC, MRC, and TRC, respectively. The total dissolved solute (TDS) exports were 82%, 77%, 75%, of the corresponding imports in JRC, MRC, and TRC, respectively. Simple correlations indicated that nitrate export was positively correlated with the outflow in each one of the regolith and similar trends were observed between inflow and import. The import/export mass balance for nitrate shows that 73% to 96% of the imports were exported during the same rainy season, suggesting the potential for nitrate associated ecosystem health hazard/risk in sensitive SWB receiving the outflows.