Cm Of Water Research Articles

Outcome of Locally Assembled Continous Positive Airway Pressure Device in Neonates with Respiratory Distress in Low Resource Setting

Respiratory distress is the most frequent cause of neonatal admission in neonatal intensive care unit (NICU). Continuous Positive Airway Pressure (CPAP) is an effective mode of treatment in newborn with respiratory distress. CPAP is the application of positive pressure to the airways of spontaneously breathing patient throughout the respiratory cycle. Low cost CPAP can be locally assembled and used in neonates with respiratory distress to reduce the mortality. This is a cross sectional descriptive study conducted in NICU of Nepal Medical College Teaching Hospital from the period of June 2021 to September 2021 to assess the outcome of locally assembled CPAP. A total of 96 newborns with respiratory distress were included in the study. Severity of respiratory distress was assessed by Downes score. Downes score before and after CPAP were recorded. Newborn with Downes score of ≥4 was started with locally assembled CPAP. Outcome was taken as improvement when the respiratory distress was decreased with Downes score<4. And it was taken as a failure when baby required mechanical ventilation. Mean Downes score before starting CPAP was 4.81 and after CPAP was 0.51. Mean CPAP pressure was 4.27cm of water. Outcome of study showed, 80 (83.3%) babies were improved, 7 (7.3%) had failed CPAP who required mechanical ventilation and 1 (1%) baby expired. In conclusion, locally assembled CPAP shown to be equally effective as standard CPAP device and can be used as an effective alternative to mechanical ventilator in developing country with limited resource setting.

Nephro-urological outcomes of a proactive management of children with spina bifida in their first 5 Years of life

The proactive management of spina bifida (SB), especially of its severe form, myelomeningocele (MMC), has contributed to decreasing chronic kidney disease (CKD). The objective of this study is to present the evolution of 5-year-old patient with MMC followed from birth with a proactive approach. This retrospective study included 55 cases with MMC of up to 5 years of age. All of them were admitted at birth and followed by a multidisciplinary group, with a proactive approach: CIC and anticholinergics. In the same group, the variables were compared within the first year and the within the fifth year of life. Chronic kidney disease (CKD) was defined by: alterations on renal DMSA scintigraphy; alterations in microalbuminuria/creatininuria ratio, proteinuria 24 hs and decrease in glomerular filtration rate (GFR) calculated with Schwartz bedside equation. Although overactivity, UTI and VUR decreased throughout the first 5 years (49, 9 and 12%), reduced cystometric capacity, DLPP >40 cm of water and end-filling pressure (Pdet) >20 cm of water increased (41, 27 and 61%). All patients at 5 years of age required CIC. Reduced cystometric capacity and VUR were more significant with abnormal DMSA (36%) at 5 years old ( p: 0.03). Proteinuria and CKD increased to 25% and 49%. Similarly, the need for enalapril increased from 10% to 27%. The microalbuminuria/creatininuria ratio was pathological in 27.3%. 48 patients (87%) remained unchanged on DMSA scan and the other 7 underwent modifications (4 new cases with altered DMSA) over time. Of the 32 normal DMSA cases without changes, 81% did not present proteinuria and 88% continued to respond favorably to oxybutynin. GFR <90 ml/min/1.72m 2 was found in only 3 cases with abnormal DMSA. There was a RR 1.91 (IC95% 1.15-3.16) greater of renal compromise in cases that were anticholinergic-resistant compared to non-refractory cases. Over time, some patients suffered loss of bladder wall compliance, despite the proactive approach. There is an association between abnormal renal DMSA, reduced bladder capacity, and VUR at 5 years of age. Although proteinuria, CKD and enalapril requirement increased over 5 years, almost 90% did not show changes in renal DMSA status. Over time, some patients suffered loss of bladder wall compliance. Hence, even if a proactive approach is followed since birth, it is essential to continue with the ongoing monitoring of the renal status and thus avoid greater renal deterioration.

Experimental flooding modifies rhizosphere conditions, induces photoacclimation and promotes antioxidant activities in Rhizophora mucronata seedlings

Abstract Survival of mangrove seedlings under flooding depends on their tolerance and adaptation. This study investigated the effects of flooding on rhizosphere conditions: porewater dissolved oxygen (DO), pH, and soil oxidation–reduction potential (ORP) and photosynthetic and antioxidant activities (superoxide dismutase [SOD] and guaiacol peroxidase [POX] activity and glutathione [GSH] content) of Rhizophora mucronata seedlings. The experiment lasted 20 days with three treatments: control (with drainage), waterlogging (10 cm of water above the soil surface) and submergence. Our results demonstrate that waterlogging and submergence resulted in a reduction in porewater DO, pH and soil ORP from day 5 into the treatment. Submergence resulted in lower maximum electron transport rates, lower saturating irradiance and higher light utilization efficiency from day 5 onwards, but stomatal closure was detected in both flooded treatments. POX activity and GSH content in the roots were increased by submergence. On day 5, submerged plants showed higher root POX activity than the other two treatments and higher root GSH content than controls. However, these parameters decreased on day 20, so that no difference among the treatments remained. As persistent flooding was shown to hamper the physiological performance of mangrove seedlings, extreme weather events and sea-level rise should be closely monitored.

A Left Atrial Mass in the Time of COVID

A 60-year-old woman presented to the emergency department with chest pain and worsening dyspnea. On initial vital signs, she was afebrile with a blood pressure of 160/107 mmHg, a heart rate of 89 beats/min, a respiratory rate of 30 breaths/min, and an oxygen saturation of 95% on 4 liters oxygen via nasal cannula (an increase from her home requirement of 2 liters oxygen via nasal cannula). Her weight on presentation was 10.9 kg above her baseline. Her exam was notable for elevated jugular venous pressure to 14 cm of water, rales in bilateral lung bases without wheezes, and significant bilateral lower extremity edema to her thighs.

Evaluation of the influence of individualized protective ventilation on the lung mechanical properties

The work is devoted to the study of the influence of individualized protective ventilation support on pulmonary mecha-nics. The study included 47 patients who underwent open abdominal surgery under general anesthesia. All patients had a moderate to high risk of developing postoperative pulmonary complications by the ARISCAT scale. Intraoperatively, the impact of individualized protective ventilation on respiratory mechanics, namely Ppeak, Pplat, Pdrive, dynamic pulmonary compliance was assessed. Individualized protective respiratory support was ventilation with a tidal volume of 7 ml/kg of ideal body weight, with the selection of the optimal level of positive pressure at the end of exhalation (PEEP), focusing on dynamic pulmonary compliance and performing recruiting maneuver, and then in the case of a decrease in dynamic pulmonary compliance by more than 20 %, followed by re-selection of PEEP. The studied parameters were recorded before and after the recruiting maneuver, as well as on the 30th, 60th, 90th, 120th, 150th, 180th minutes after the recruiting maneuver, depending on the duration of the operation. The use of alveolar straightening techniques led to an improvement in pulmonary mechanics, namely, an increase in dynamic pulmonary compliance by 16 % and a decrease in Pdrive by 17 %. The intraoperative level of PEEP averaged 4 [4; 5] cm of water. No cases of hypoxemia or recurrence of recruiting maneuver were reported. The obtained results indicate that chosen technique of recruiting maneuver is effective and safe, and its use allows reducing the negative impact of mechanical ventilation. The study did not find a statistically significant correlation between the level of PEEP and the value of dynamic pulmonary compliance. Such data prove the need for individual selection of ventilation parameters according to the characteristics of the mechanical properties of each patient.

Influence of agricultural managed aquifer recharge on nitrate transport: The role of soil texture and flooding frequency

AbstractAgricultural managed aquifer recharge (Ag‐MAR) is a concept in which farmland is flooded during the winter using excess surface water to recharge the underlying groundwater. In this study, we show how different recharge practices affect NO3− leaching and mineralization–denitrification processes in different soil systems. Two contrasting soil textures (sand and fine sandy loam) from the Central Valley, California, were repeatedly flooded with 15 cm of water at varying time intervals in field and soil column experiments. Nitrogen species (NO3–, NH4+, total N), total C, dissolved O2, and moisture content were measured throughout the experiments. Results show that when flooding occurs at longer intervals (every 1–2 wk), N mineralization increases, leading to an increase of mobile NO3− in the upper root zone and leaching of significant quantities of NO3− from both soil textures (137.3 ± 6.6% [sand] and 145.7 ± 5.8% [fine sandy loam] of initial residual soil NO3−) during subsequent flooding events. Laboratory mineralization incubations show that long flooding intervals promote mineralization and production of excess NO3− at rates of 0.11–3.93 mg N kg–1 wk–1 (sand) and 0.08–3.41 mg N kg–1 wk–1 (fine sandy loam). Decreasing the flooding frequency to 72 h reduces potential mineralization, decreasing the amount of NO3− leached during flooding events (31.7 ± 3.8% [sand] and 64.7 ± 10.4% [fine sandy loam] of initial residual soil NO3–). The results indicate that implementing recharge as repeated events over a long (multiple‐week) time horizon might increase the total amount of NO3− potentially available for leaching to groundwater.

2,4-D and dicamba removal from the surface of plastic mulch using overhead irrigation: analytical analysis and cucurbit bioassay crop response

AbstractGlyphosate and paraquat are effective preplant burndown herbicide options for multicrop vegetable production that uses plastic mulch, but problematic weeds such as wild radish, cutleaf evening primrose, annual morningglory, or horseweed may not be adequately controlled with these herbicides alone. The herbicides 2,4-D and dicamba could help control these troublesome weeds prior to planting if they can be removed from plastic mulch and thus avoid crop damage. Treatments included 2,4-D (1,065 and 2,130 g ae ha−1) and dicamba (560 and 1,120 g ae ha−1) applied broadcast over plastic mulch a day before transplanting. Just before transplanting, treatments received either 0.76 cm of water via overhead irrigation or no irrigation. Plastic mulch samples were collected at application and planting to determine herbicide presence using analytical techniques, and cantaloupe and zucchini squash were subsequently transplanted on the plastic beds. Analytical ultra-high performance liquid chromatography revealed that 88% to 99% of the initial herbicide concentration was present at crop planting when irrigation was not implemented. At most, a 1/50 rate of dicamba and a 1/500 rate of 2,4-D was present at planting when overhead irrigation was applied prior to transplanting. Maximum cantaloupe and squash injury from 2,4-D with irrigation was 10% and did not influence plant growth, biomass, or yield. For dicamba with overhead irrigation, cantaloupe injury was 35%, vine lengths were reduced by 24%, and maturity was delayed, whereas squash injury ranged from 9% to 12%, with no influence on growth or yield. Without irrigation to wash herbicides from the mulch prior to planting, 60% to 100% injury of both crops occurred with both herbicides. Zucchini squash was more tolerant to dicamba than cantaloupe. Results demonstrated that 2,4-D can be adequately removed from the surface of plastic mulch with irrigation, whereas a single irrigation event was not sufficient to remove dicamba.

Idiopathic intracranial hypertension with initial presentation of optic disc edema

Abstract Introduction: Idiopathic intracranial hypertension (IIH) is a disorder of elevated intracranial pressure in young women of childbearing age. The typical symptom is headache, and the symptom of visual obscuration tends to be overlooked. So, the patients usually visit the department of neurology for headache management. Here, we report a patient with IIH who first presented with ophthalmic symptoms. Patient concerns: A 28-year-old overweight female complained of intermittent darkened vision in both eyes lasting for 2 months. She was diagnosed with papilledema at another hospital and received local and systemic application administration of neurotrophic drugs and glucocorticoids 1 month before. Because of the poor outcomes, she visited our ophthalmology clinic for further management. She had no other medical history. Diagnosis: On ophthalmic examination, bilateral optic disc edema with blurred boundary was observed. The cranial magnetic resonance imaging and blood examination showed no obvious abnormality. A lumbar puncture was performed by a neurologist, which demonstrated an opening pressure of 30 cm of water. The cerebrospinal fluid biochemistry and bacteriology results were normal. A diagnosis of IIH was made based on the above findings. Outcomes: Oral acetazolamide, weight loss therapy and local corticosteroid treatment were initiated. At 7-week follow-up, the darkened vision and optic disc edema was obviously alleviated. Conclusion: IIH is a neurologic disease, but patients with this disease may first present to ophthalmology department because of the visual symptoms, such as blurred or darkened vision, visual loss, and even diplopia. As ophthalmologists, we should screen for this disease in a timely manner when we encounter similar patients with bilateral optic edema.

Ambient moisture causes methomyl residues on corn plants to rapidly lose toxicity to the pest slug, Arion subfuscus, Müller (Gastropoda, Stylommatophora)

The carbamate insecticide methomyl is sometimes used to control slugs in field corn and soybean by foliar applications, but control outcomes in research trials and commercial operations have been mixed. In this study, laboratory bioassays were conducted on dusky slug, Arion subfuscus Müller, a common pest of corn and soybean in the Mid-Atlantic United States, to evaluate residual toxicity of Lannate LV (methomyl) at low and high concentrations corresponding to label recommended field rates, and if toxicity may be affected by ambient moisture or repellency to treated plants. Without wetting events, methomyl residues on corn plants caused 90–100% mortality of A. subfuscus for two days and 70–90% mortality for six days. When corn plants were briefly misted with ca. 0.3 cm of water 6 h after methomyl application, mortality was 36% 12 h after treatment, and 0 to 5% 24 h after treatment for both low and high rates. Repellency of A. subfuscus to corn plants treated with the high rate of methomyl was narrowly significant (P = 0.04) and low rate was not significant. These results suggest that high ambient moisture needed to elicit slug activity in the field also abates toxicity of methomyl residues, explaining why field control is usually poor despite high mortality in the lab.

Transthoracic echocardiogram by protocol apical-subcostal in prone position during invasive mechanical ventilation

Funding AcknowledgementsType of funding sources: None.IntroductionDuring COVID-19 pandemic reports increased of transthoracic echocardiography (TTE) in prone and invasive mechanical ventilation (IMV), mostly describing four and five chamber apical views, and inferior vena cava (IVC) by lateral IVC window (from right side of the patient).PurposeEvaluate quality of images obtained with protocol of apical-subcostal TTE in patients with IMV and prone position.MethodsProspective study, between August and December 2020, in adults who required prone position during IMV. After placing the patient in the prone position, left arm was extended overhead, and a pillow was placed only under the left hemithorax to elevate and facilitate the apical window and space below the patient for subcostal window. Operator stands on the left side of the patient and takes images with the transducer in your right hand, starting with apical window and subsequently subcostal window. Apical views were apical four, two and three-chambers, to obtain function parameter of right and left ventricle (LV), evaluation of aortic valve, mitral and tricuspid valve. Subcostal views were four cardiac chambers and IVC, to obtain qualitative ventricle function, presence of pericardial effusion, and volume status and estimation of pulmonary pressure (together to peak systolic tricuspid pressure gradient from apical views). The images were acquired by cardiologist, then were saved, and finally evaluated by two echocardiography cardiologist experts.Results16 ETTs were performed. Male gender and obesity predominate. Positive end-expiratory pressure average was 10.8 cm of water. One patient cannot be assessed by absence of acoustic window and the rest (n = 15) were analyzed with experts. It was achieved a four-chamber apical view in 100% (n = 15), a two-chambers apical view in 60% (n = 9) and a three-chambers apical view in 100% (n = 15). It was possible to assess global function of the LV in 100% (n = 15), LV segmental function in 53% (n = 8), LV outflow tract velocity time integral in 100% (n = 15) and tricuspid annular plane systolic excursion in 100% (n = 15). Pulsed wave doppler of mitral valve in 100% (n = 15) and tissue doppler of lateral mitral valve annulus 100% (n = 15). Continuous wave doppler of aortic valve in 100% (n = 15) and tricuspid valve in 93% (n = 14). Subcostal four-chamber 80% (n = 12), presence pericardial effusion 100% (n = 15) and IVC 93% (n = 14). Non-complications associated with obtaining the position.ConclusionsETT in the prone position during IMV was possible and interpretable images were achieved. The position described allows assessment by apical and subcostal views at the same time and position of the operator and the patient. In addition, it was a safe technique, and the position was easy to be incorporated by the health team. Limitations were obtaining the two-chamber apical view and evaluation of segmental alterations of the LV. Better validation requires a larger sample.

Development and characterization of a water-based muon veto for the v-Angra Experiment

The ν-Angra experiment has developed an antineutrino detector intended to operate at sea level, a few dozen meters from the core of a nuclear reactor. The operating principle of the detector is based on the water Cherenkov light detection to be in compliance with the safety rules of the power plant operator. The detector is exposed to a high rate of background events, mainly due to cosmic rays, making its veto system a key element for efficient background rejection. The ν-Angra Collaboration has designed a veto detector composed of three layers filled with water for both passive shielding and active detection of crossing particles. The veto surrounds a volume of 1.50 × 1.05 × 1.39 m3, in which a target detector is placed, where the search for anti-neutrino events occurs. Any external particle hitting the detector must cross at least 25 cm of water before reaching this internal volume, which is protected by the veto structure, thus providing an important barrier against neutrons and low energy particles. In addition, the veto system has been instrumented with eight 8-inch photomultiplier tubes to detect external particles that may eventually reach the target detector. By making use of a trigger system based on scintillating paddles, energy distribution and detection efficiency of the veto system were assessed for different detector positions. This paper, therefore, presents the achieved results related to the characterization of such system concerning the detection of cosmic-ray muon particles passing through it.

Improving Water Use Efficiency through Reduced Irrigation for Sustainable Cotton Production

The socio-economic development of a country is highly dependent on water availability. Nowadays, increasing water scarcity is a major global challenge. Continuing improvements in water-use efficiency are essential for cotton production sustainability. Reduced irrigation in cotton could be a solution to water shortage in the arid climate without compromising the cotton yield. Therefore, a two-year field study was conducted to assess the effect of two levels of irrigation i.e., 50% and 100% of available water content (AWC) on the yield of four cotton genotypes (CIM-678, CIM-343, CRIS-613, and CYTO-510). The maximum seed cotton yield was observed in CIM-678, which was 2.31 and 2.46 Mg ha−1 under 100% AWC during 2018 and 2019, respectively, and was non-significantly reduced by 7.7 and 8.94%, owing to deficit irrigation. The maximum water use efficiency (WUE) of 0.55 and 0.64 Kg ha−1 mm−1 was observed under 50% AWC in CIM-678, which was significantly higher than WUE at 100% AWC during both years. Leaf area index and physiological parameters such as photosynthesis rate, transpiration rate, and stomatal conductance were not significantly affected by deficit irrigation. So, it was concluded that the reduced irrigation technique performed well without significant yield loss, improve WUE, and saved 37 cm of water that could be used for other crops or to increase the area of the cotton crop.

Evaluation of the temporal variations of groundwater storage and its interactions with climatic variables using GRACE data and hydrological models: A study from Turkey

AbstractMonitoring of the fluctuations of groundwater storage is particularly important in arid and semi‐arid regions where water scarcity brings about various challenges. Remote sensing data and techniques play a preponderant role in developing solutions to environmental problems. The launch of Gravity Recovery and Climate Experiment (GRACE) satellites has eased the remote monitoring and evaluation of groundwater resources with an unprecedented precision over large scales. Within the scope of the current study, the latest release (RL06) of GRACE mass concentrations (Mascons) from Jet Propulsion Laboratory (JPL) dataset as well as Global Land Data Assimilation System (GLDAS) models of Noah and Catchment Land Surface Model (CLSM) were used to provide Groundwater Storage Anomalies (GWSA) over Turkey. The temporal interactions of the estimated GWSA with the climatic variables of precipitation and temperature (derived from the reanalysis datasets of CHELSA [Climatologies at High resolution for the Earth's Land Surface Areas] and FLDAS [the Famine Early Warning Systems Network Land Data Assimilation System], respectively) were investigated statistically. The results suggest that there is a descending trend (from 2003 to 2016) for Terrestrial Water Storage Anomalies (TWSA) and GWSA over Turkey with a total loss of 11 and 6 cm of water, respectively. The statistical analysis results also indicate that the monthly variations of GWSA over Turkey are highly correlated with precipitation and temperature at 2‐month lag. The analysis of the climatology (long‐term) values of monthly GWSA, precipitation and temperature also revealed high agreement between the variables.

Lumbo-peritoneal shunt as treatment modality for visual symptoms in idiopathic intracranial hypertension: A single institution experience

ObjectivesTo evaluate the efficacy of lumbo-peritoneal shunt (LPS) in patients of idiopathic intracranial hypertension presenting with visual symptoms. MethodsBetween Apr. 2014 and Mar. 2018, 70 patients of Idiopathic Intracranial Hypertension (IIH) underwent treatment at our institution. Patients were evaluated for neurological and ophthalmological status and were subjected to LPS depending on their symptoms. ResultsMean opening pressure was 29.97±5.33cm of water and mean Body-Mass Index (BMI) was 26.51±3 and the two were significantly correlated (p-value 0.006). All patients with visual symptoms (23) underwent LPS and others (47) were managed medically. All patients with LPS and 25 of medically managed patients improved, while 22 medically-managed patients required LPS due to deterioration in visual symptomatology. The proportion of patients showing complete resolution of features of IIH was significantly different between the three groups. Of the 7 patients with shunt extrusion/migration, only 2 required revision. ConclusionLPS is an equally effective and more technically familiar modality for treatment of IIH for neurosurgeons and should be offered to asymptomatic patients with objective visual signs. Shunt extrusion/migration may not always warrant revision due to “mini-shunt” that drains Cerebro-Spinal Fluid (CSF) through shunt tract even after extrusion.

A dual-frequency piezoelectric micromachined ultrasound transducer array with low inter-element coupling effects

This paper presents a dual-frequency piezoelectric micromachined ultrasonic transducer (PMUT) line array with low crosstalk level, which was fabricated on silicon-on-insulator (SOI) wafers with sputtered piezoelectric thin film (PZT) and Si diaphragm structure. The obtained array consists of 120 of 0.77 MHz and 192 of 2.30 MHz PMUT units in total with minimum interspace of 50 μm. Due to the high piezoelectric coefficient of PZT, the PMUT shows high transmitting sensitivity in air and good effective electromechanical coupling factor. The displacement sensitivities are assessed to be 595 nm V−1 and 112 nm V−1 at the resonant frequencies of 0.77 MHz and 2.30 MHz respectively in air. To reduce the vibration coupling, rectangular grooves in the bottom silicon are designed between the adjacent line elements, and the PMUT units in the array are arranged in a mis-aligned style. Modal analysis for the 0.77 MHz units indicates neighbouring coupling-vibration decreases greatly from 44.5% to 14.8% of the excited vibration when the excited line is driven at 4Vpp, which proves both the grooves and the mis-aligned ranking are effective for coupling effect reduction. Moreover, results indicate the coupling effect between different frequencies can be ignored due to their inherent resonance characteristics. The sound pressures for a single 0.77 MHz line element and 2.30 MHz line element are evaluated to be 53 kPa and 73 kPa at a distance of 1 cm in water. This high performance dual-frequency PMUT line array makes some high resolution imaging methods possible based on PMUT technology, such as those of dual-frequency, total focus.

Experimental modelling and human data of glottal area declination rate for vowel and semi-occluded vocal tract phonation

ObjectiveThe aim of this study was to investigate how the maximum area declination rate (MADR) of the glottis corresponds to the maximum velocity of the self-oscillating vocal folds just before their collision. The maximum velocity before collision is closely related to impact stress in the colliding vocal folds and, thus, it is an important indicator of vocal loading. MethodsHigh speed imaging data for a male subject and measurements of the glottal area waveforms performed on a physical 1:1 scaled model for phonation on vowel [u:] were compared with those obtained during a semi-occluded vocal tract which increases voice source-vocal tract interaction. Semi-occlusion was obtained by phonation through a glass resonance tube with the distal end in air or submerged 10 cm in water. ResultsThe results show that the area declination rate of the glottis, i.e., closing velocity, before the glottal closure is substantially lower than the MADR, and also lower in semi-occluded vocal tract phonation through a tube into air and into water than in vowel phonation. ConclusionsThe results suggest that MADR is not a reliable estimate of impact stress, and that impact stress in tube therapy is lower than in vowel phonation.

Development and validation of an optimal GATE model for double scattering proton beam delivery

Proton therapy (PT) is an emerging external beam radiation therapy characterized by superior dose distribution compared to conventional modalities. In the present study, an optimal GATE model was developed and then validated for a double scattering proton nozzle based on the previously constructed model. To this aim, a double scattering treatment nozzle was modeled in the GATE platform. To accelerate the GATE simulations, a virtual range modulation wheel (vRMW) and a variance reduction technique (VRT) were implemented. Proton beam flatness, symmetry, and delivery efficiency, secondary neutron dose, and dosimetric performance were characterized through a set of GATE simulations. The findings show that range cutoff value of 0.075 mm provides the best compromise between the simulation accuracy and speed for the simulated geometry. A proton beam flatness of 98.6% was observed at the downstream of the aperture for a 7 × 7 cm2 field size. The beam flatness deteriorates at the edge of the treatment field for the single scattering model while it remains approximately constant for the double scattering one. In comparison to the single scattering delivery, the second scattering model results in a 1.28 times increase in neutron dose for the nickel, as the optimal collimator/aperture material. Furthermore, a flat beam modulation width of 3.50 cm is formed with a distal edge at 7.86 cm in water using both GATE and MCNPX codes. The GATE model agreed with the MCNPX results with a maximum difference of ±6.3% in absorbed dose estimation. The findings demonstrate that the constructed GATE model of double scattering proton nozzle results in a fast and accurate simulation of passive scattering PT.

Buzzer versus water resistance phonation used in voice therapy. Results obtained with physical modeling

ObjectiveMechanical buzzers have been developed to clear excessive mucus from the lungs and trachea. Recently, they have been tested for voice therapy. By rapidly interrupting airflow they cause an oscillation of oral pressure, resembling phonation through a tube into water, which is traditionally used in voice therapy (water resistance therapy, WRT). This study compared phonation through a buzzer (Shaker deluxe™) with WRT with a glass resonance tube. MethodsMeasurements were made for subglottic and oral air pressures, airflow, transglottic pressure (Ptrans) and peak-to-peak (p-t-p) oral pressure oscillation, and for glottal area variation, using a physical model of voice production, as such detailed study is not possible in humans. High-speed-imaging was used to study glottal area variation during phonation. Shaker was tested in both horizontal and upright positions. ResultsShaker upright had slightly higher flow resistance than resonance tube 10 cm in water, while Shaker horizontally had ca half of that. Ptrans was lower for Shaker in both positions, and maximum glottal amplitude and maximum glottal area declination rate were lower. Buzzing frequency for Shaker horizontally approximately corresponded to water bubbling frequency, while it was about twice that for Shaker upright. P-t-p oral pressure oscillation was higher in WRT, seemingly due to the much lower frequency of the lowest acoustic resonance of the vocal tract prolonged by the resonance tube. ConclusionsWRT may offer stronger ‘massage-like’ effect for the vocal tract and vocal folds than Shaker, while Shaker may promote softer phonation.

Role of urodynamics in male patients of high-anorectal malformations: a prospective study.

Association of spinal or vertebral anomalies and the iatrogenic denervation during surgical correction of anorectal malformation patients especially in boys can lead to neurogenic bladder inthese subset of patients. The paucity of literature with regard to urodynamic studies focusing exclusively in male children with high-anorectal malformations (HARM) lead us to analyze the urodynamic changes. The objective was to study urodynamic profile in male patients who have undergone surgery for anorectal malformation. Male high-anorectal malformation patients who had completed all the stages of repair were prospective studied. Following the basic work up, all patients based on the urodynamics were categorized into 2 groups as safe or unsafe bladders. Unsafe bladder was defined as detrusor pressure > 40cm (high detrusor pressure) or pressure variability of 15cm of water (detrusor overactivity) or significant post-void residue. MRI was limited to patients with only abnormal urodynamics to rule out spinal causes of neurogenic bladder and due to financial constraints, it could not be offered to all patients. 41 HARM meet the exclusion criteria. All patients were asymptomatic with none having history of urinary tract infections. Ultrasound showed bladder wall thickening in 31.7% patients. UDS revealed reduction in bladder capacity and compliance was noted in 31.7% and 30% patients, respectively. Elevated detrusor pressures (> 40cm of water) were noted in 10% (4/41), detrusor overactivity with concomitant elevated detrusor pressures in 19.5% (8/41) and normal UDS in 70% (29/41). 13 patients (31.7%) had abnormal cystometric parameters with 12(30%) having unsafe bladders. MRI confirmed sacral agenesis in 1 patient with unsafe bladder. Urodynamics can demonstrate occult neurovesical dysfunction in patients with HARM. This would help in early renal protective therapy and prevent the burden of long-term sequelae of neurovesical dysfunction in HARM patients.

Are water precautions necessary after tympanostomy tube placement? A cadaver study

ObjectivesTo determine whether Armstrong pressure equalization tubes allow passage of water into the middle ear with complete submersion in water up to 76 cm for 2 min. Methods10 adult cadaver heads were first assessed for the presence of fluid in both middle ears with zero-degree rigid endoscopes, after being submerged for 2 min in a plastic receptacle filled with 76 cm of water. A 25% perforation was then made in the tympanic membrane of one ear. A myringotomy was then made in the tympanic membrane of the contralateral ear, with the placement of a beveled Armstrong pressure equalization tube. The head was then submerged again for 2 min. Both ears were then examined for the presence of fluid in the middle ear using a rigid endoscope and with suction. ResultsEight out of ten (80%) of the heads showed the presence of fluid in the middle ear on the perforation side after submersion, whereas none of the heads showed fluid in the middle ear on the side with the pressure equalization tube. ConclusionsAt depths of 76 cm, total submersion in water for 2 min does not facilitate the passage of water into the middle ear via an Armstrong pressure equalization tube.