Feed Volume Research Articles

Gastric emptying of milk in infants and children up to 5years of age: normative data and influencing factors.

Gastric emptying scintigraphy is widely used in infants and children, but there is a lack of age-specific normative data. The objectives of this retrospective study were: 1) to establish a range of gastric emptying of milk or formula as a surrogate for normal gastric emptying in infants and young children ≤5years of age, and 2) to investigate the effects of patient age, feeding volume, feeding route and gastroesophageal reflux on gastric emptying. The reports of 5,136 gastric emptying studies of children ≤5years of age performed at Children's National Medical Center from January 1990 to August 2012 were reviewed. Demographic data, 1-h and 3-h gastric emptying values and gastroesophageal reflux status of all patients were stored in a database. Using stringent inclusion and exclusion criteria, the studies of patients as similar to healthy children as possible were selected for this study. The study group included 2,273 children (57% male) ages 0-59months (median: 4.6months). The median 1-h gastric emptying was 43% (interquartile range [IQR] 34-54%). The median 3-h gastric emptying was 91% (IQR 79-98%). Sixty-one percent of patients with 1-h gastric emptying value of <50% had 3-h gastric emptying ≥80%. Gastric emptying was significantly faster in children ≤6months as compared with all older age groups. In each age group, the median gastric emptying decreased with increasing feeding volume. Gastric emptying was significantly faster in patients fed via combined nasogastric tube and oral routes as compared with those fed exclusively orally. There was no significant difference in gastric emptying of children with and without gastroesophageal reflux. Although there are statistically significant differences in gastric emptying based on age, volume and route of feeding, the data suggest that overall normal liquid gastric emptying in infants and children ≤5years of age is ≥80% at 3h. One-hour emptying measurements are not reliable for detecting delayed gastric emptying.

Ultrasound-assisted digestate treatment of manure digestate for increased biogas production in small pilot scale anaerobic digesters

In this study, ultrasound (US) disintegration was evaluated as a digestate treatment strategy. Digestate treatment is the physical, chemical or biological treatment and recirculation AD of the effluents of the anaerobic digesters (i.e., digestate) to the digester as supplementary feed to increase their utilization potential for energy conversion or green chemical production in post-valorization pathways. In this scope, semi-continuous small pilot scale manure digesters were operated in parallel with various operational settings. One of the digesters was fed by adding disintegrated digestate to an equal volume of fresh manure feed (recycle ratio of 1). The obtained results showed that US-assisted digestate treatment at 1500 kJ/kg TS specific energy input with 30 days of hydraulic retention time increased the methane production rate by 18%. The increased methane production rate was found to be related to the applied specific energy and organic loading rate. A basic cost-benefit analysis showed that the energy demand of the US disintegration at lab scale was higher than the energy that can be recovered from the additional biogas produced.

Effect of 100% human milk-derived fortifier on growth of premature infants with birth weight of 1000–1500 g

Background: Preterm birth has the highest risk of perinatal morbidity and mortality. Nutrition plays a key role in the growth and development of a preterm infant. Fortification of expressed breast milk is followed to provide an optimal nutrition and a faster catch up growth. The new 100% human milk-derived fortifier (HMDF) can help in providing a safe nutritional option for a premature infant. Objective: The objective of the study was to assess the feed tolerance and impact of a new 100% HMDF on growth outcomes of preterm infants. Materials and Methods: In a single-center study, exclusively human milk-fed preterm infants (1000–1500 g birth weight) were chosen to receive human milk fortified with a new 100% HMDF. The fortifier was initiated when the enteral feed volume reached 100 ml/kg/day and was administered until discharge. The primary outcome of the study was to assess feed tolerance and the secondary endpoints included growth parameters. Results: The cohort study comprised 13 infants with a mean gestational age of 31.64±2.2 weeks and birth weight of 1314.62±110.1 g. During the study period, feed interruptions were nil and none of the infants showed any adverse events of clinical significance. Growth outcomes recorded at the end of the study period showed a mean weight gain of 25.97±7.7 g/day, mean length gain of 0.32±0.23 cm/week, and mean head circumference gain of 0.39±0.20 cm/week. The mean weight growth velocity of the infants was 18.37±5.1 g/kg/day. Conclusion: Preterm infants who received a new 100% HMDF demonstrated feed tolerance and weight gain without any clinically significant record of adverse events. The findings indicate that the new HMDF is a safe option for providing an exclusive human milk-based diet. However, a study with a larger study population may be required to reinforce the findings of this study.

Sea salt bittern-driven forward osmosis for nutrient recovery from black water: A dual waste-to-resource innovation via the osmotic membrane process

A dual “waste-to-resource” innovation in nutrient enrichment and recovery from domestic black water using a sea salt bittern (SSB)-driven forward osmosis (FO) process is proposed and demonstrated. The performance of SSB as a “waste-to-resource” draw solution for FO was first evaluated. A synthetic SSB-driven FO provided a water flux of 25.67±3.36 L/m2 · h, which was 1.5–1.7 times compared with synthetic seawater, 1 M NaCl, and 1 M MgCl2. Slightly compromised performance regarding reverse solute selectivity was observed. In compensation, the enhanced reverse diffusion of Mg2+ suggested superior potential in terms of recovering nutrients in the form of struvite precipitation. The nutrient enrichment was performed using both the pre-filtered influent and effluent of a domestic septic tank. Over 80% of phosphate-P recovery was achieved from both low- and high-strength black water at a feed volume reduction up to 80%–90%. With an elevated feed pH (∼9), approximately 60%–85% enriched phosphate-P was able to be recovered in the form of precipitated stuvite. Whereas the enrichment performance of total Kjeldahl nitrogen (TKN) largely differed depending on the strength of black water. Improved concentration factor (i.e., 3-folds) and retention (>60%) of TKN was obtained in the high-nutrient-strength black water at a feed volume reduction of 80%, in comparison with a weak TKN enrichment observed in low-strength black water. The results suggested a good potential for nutrient recovery based on this dual “waste-to-resource” FO system with proper management of membrane cleaning.

Renal function in the third year among very low birth weight infants fed by supplemental proteins

Very Low Birth Weight (VLBW) infants have higher nutritional needs than term infants. Energy and protein are two important factors influencing their growth. Breastfeeding is not enough to meet VLBW infants’ needs, for this reason, complementary protein is required by them. Hence, the present study aimed at investigation of renal function among VLBW infants receiving complementary proteins. The study was conducted on two groups of intervention and control (n= 18 in each group) (Case study: VLBW infants born in Akbarabadi hospital of Tehran in 2014 2015). The intervention group includes 3-year-old children who weighting less than 1200 grams at birth and have received protein supplementation at the course of NICU hospitalization, protein was added to maternal milk when the amount of milk reaches to 100 cc/kg/day, at this time parenteral nutrition was discontinued and the volume of feeding was increased 20cc/kg/day until reached to 150-180cc/kg/day. We also added the fortifier to breast milk at this time. The fortification and the protein supplementation were stopped when the weight of the baby reached to 1500 grams. The control group was fed similar to the intervention group but had received no complementary protein . The renal function was evaluated by measuring such criteria as BUN, Cr, ALB and U/A. After data collection, a statistical analysis was performed using SPSS software Ver. 22. Following to BUN evaluation, a significant correlation was seen between BUN and received protein (p-value=0.010). However, there was no significant correlation between Cr and received protein as well as mean values of the two groups (p-value=0.0766). Similarly, an insignificant correlation was found between the two groups following to investigation of ALB (p-value=0/257), while the mean values of the two groups were similar. The both groups were also equal in U/A. The complementary protein increased the BUN with no effect on Cr, ALB and U/A, providing no impact on renal function. Therefore, complementary protein intake made no conflict in renal function.

Renal function in the third year among very low birth weight infants fed by supplemental proteins.

Very Low Birth Weight (VLBW) infants have higher nutritional needs than term infants. Energy and protein are two important factors influencing their growth. Breastfeeding is not enough to meet VLBW infants’ needs, for this reason, complementary protein is required by them. Hence, the present study aimed at investigation of renal function among VLBW infants receiving complementary proteins. The study was conducted on two groups of intervention and control (n= 18 in each group) (Case study: VLBW infants born in Akbarabadi hospital of Tehran in 2014 2015). The intervention group includes 3-year-old children who weighting less than 1200 grams at birth and have received protein supplementation at the course of NICU hospitalization, protein was added to maternal milk when the amount of milk reaches to 100 cc/kg/day, at this time parenteral nutrition was discontinued and the volume of feeding was increased 20cc/kg/day until reached to 150-180cc/kg/day. We also added the fortifier to breast milk at this time. The fortification and the protein supplementation were stopped when the weight of the baby reached to 1500 grams. The control group was fed similar to the intervention group but had received no complementary protein . The renal function was evaluated by measuring such criteria as BUN, Cr, ALB and U/A. After data collection, a statistical analysis was performed using SPSS software Ver. 22. Following to BUN evaluation, a significant correlation was seen between BUN and received protein (p-value=0.010). However, there was no significant correlation between Cr and received protein as well as mean values of the two groups (p-value=0.0766). Similarly, an insignificant correlation was found between the two groups following to investigation of ALB (p-value=0/257), while the mean values of the two groups were similar. The both groups were also equal in U/A. The complementary protein increased the BUN with no effect on Cr, ALB and U/A, providing no impact on renal function. Therefore, complementary protein intake made no conflict in renal function.

The Influence of Donor Milk Supplementation on Duration of Parenteral Nutrition in Preterm Infants.

Data are limited on the association between the use of donor human milk and improvements in feeding tolerance. To determine the influence of the duration of parenteral nutrition on the growth and morbidity of the breastfed newborn when using donated human milk in the absence of mother's own milk. We conducted a retrospective study before and after the intervention that compared two groups of newborns (N = 284; each group n = 142). We used a convenience sample of all newborns ≤32 weeks gestation consecutively admitted in a single unit before (Group 1 between December 2012 and May 2014) or after (Group 2 between October 2014 and December 2016) the availability of donor human milk. In Group 2, donor human milk was administered at least 3 to 4 weeks or until the baby weighed 1,500 g. Weight was recorded daily and length and head circumference weekly. Parenteral nutrition was continued until enteral feeding volume reached 120 ml/kg/day. Additional variables measured were the number of days with a central venous catheter, age that the enteral feeding volume reached 150 ml/kg/day, and duration of stay. The duration of parenteral feeding was the same before and after: 12 (8.23) and 11 (7.19) days (p = .822). The z scores for weight and height of newborns was lower in Group 2 = -1.8 (1.0) and -2.3 (1.1) and Group 1 = -1.2 (1.1) (p < .001) and -1.8 (1.4) (p = .005). We did not find an association between the administration of donor human milk as a supplement to mother's own milk and reduced number of days of parenteral nutrition. Back translation by Laurence Grummer-Strawn.

Ultrawideband Conical Log-Spiral Circularly Polarized Feed for Radio Astronomy

In order to meet the requirements of the new generation of radio telescopes, we have developed a new topology called DYQSA, which stands for DYson Quad-Spiral Array. The design exhibits dual circular polarization contrary to dual linear polarization of state-of-the-art feeds. It covers the required ultrawideband (UWB) from 2 to 14 GHz with an almost constant and real input impedance which facilitates the design of the feeding structure and the low-noise amplifiers (LNAs). Different versions are investigated for enhancing feed performance, ensuring higher aperture efficiencies and mechanical stability. The simulation results of the reflector loaded by the proposed feed show an aperture efficiency of 65%±5% with a noise antenna temperature around 14 K and a system equivalent flux density (SEFD) of about 1300 Jy, both averaged over the required bandwidth at zenith. Measurements of the single-element and the four-element feeds are presented. Comparisons with other state-of-the-art feeds are shown in terms of total aperture efficiencies, design adaptability to different reflectors, calibration signal injection, and the required number of LNAs per feed, cost, and physical volume.

Research on Recovery Mechanism and Process of Waste Thermosetting Phenolic Resins Based on Mechanochemical Method

The present study analyzed the recovery mechanism of the thermosetting phenolic resin waste, optimizing the recovery process parameters, based on the mechanochemical recovery method. The physical and chemical structure of the ultrapulverized phenolic resin powder was characterized by the low‐field NMR (nuclear magnetic resonance), IR (infrared spectroscopy), and SEM (scanning electron microscopy). The recovery process parameters were designed by using the response surface analysis method, and the multiple quadratic regression model was established and the multiobjective process parameter was optimized. The results show that the body network structure of the material is destroyed during the crushing process. The intensity of the internal cross‐linking signal is reduced and tends to be stable at about 60%, when the particle size exceeds 120 mesh. The cross‐linking bonds methylene (‐CH2‐) in the main chain of the molecular chain and the C‐O bond in the methylol group on the branch are broken. The tensile strength of the recycled sheet made of the phenolic resin powder is 8.27 MPa, and the bending strength is 17.76 Mpa through the mechanical properties test. The influences on the change rate of the cross‐linking signal intensity and the yield of the recycled powder are in the following order: rotation speed, feed size, time, and feed volume. The best recovery parameters are as follows: rotation speed of 2820 r/min, time of 80 min, feed particle diameter of 0.43 mm, and feed volume of 60 g.

Growth and development of calves depending on the method of feeding with cereal and milk

The article studies the influence of the milk feeding method on the growth and development of calves. The object of research is newborn Samara black-motley calves. It was established that after drinking the first portion of colostrum, immunoglobulin appears in the blood of calves in 2 hours. Immunoglobulin enters the bloodstream in the first 12 hours of life. The highest content of immunoglobulin (23.40 mg/ml) was observed after 48 hours in case of free suckling. It exceeded that in peers fed manually by 6.7-8.9%. Depending on the feeding scheme and method, the heifers consumed 497.0-509.4 kg of milk for three months in case of manual feeding, 589.5 kg for two months in case of free suckling, and 540.3 kg in case of regulated suckling. The technology of milk feeding, the time spent with a mother, the amount of milk consumed had a significant impact on the health of calves. The degree of calf morbidity had a significant impact on the growth and development of young animals. As a result of a greater consumption of milk and large volumes of feed, heifers under regulated suckling had a larger live weight than their peers aged 18 months by 11.1% (P &lt;0.001) (in comparison with the peers from group I), by 16.0% (P &lt;0.001) (in comparison with the peers from group II), by 17.5% (P &lt;0.001) (in comparison with the peers from group III), by 4.7% (P &lt;0.05) (in comparison with the peers from group IV).

Water Extract of Yamato Tachibana (Citrus tachibana) Induces Food Intake in Adult and Larval Zebrafish.

Yamato Tachibana (Tachibana; Citrus tachibana) is an endemic fruit and represents one of the oldest citrus species in Japan; it is grown in the Mie Prefecture. It has been attracting attention for its cultural heritage and unique scent. To evaluate biological activities of Tachibana, we fed several parts of the Tachibana fruit (whole fruit, pulp [albedo and segment wall], and flavedo) to adult zebrafish and found that Tachibana increased body weight and plasma triglycerides besides increasing overall food intake. We then created a simple fluorescence-based feeding assay using dried rotifer sheets and larval zebrafish (6 days postfertilization) to screen the various extracts of Tachibana parts. We found that water extracts of Tachibana pulp increased feeding volume in zebrafish. Although citrus species are believed to prevent obesity and obesity-associated diseases in general, our findings showed that water extracts of Tachibana increase food intake in zebrafish and lead to an increase in body weight. We suggest that Tachibana might reverse appetite loss in lean populations and may prove beneficial in aiding fish cultivation.

LAPAROSCOPIC ANASTOMOSIS IN THE ATRESIA OF SMALL BOWEL

Introduction. A complete laparoscopic intestinal anastomosis remains a challenge for pediatric surgeons. The aim of the study is to demonstrate its effectiveness in patients with small bowel atresia. Material and methods. This article describes laparoscopic surgery in a patient with small bowel atresia of type I. During laparoscopy, stitches were placed on the blind end of the atresia segment of the intestine to stabilize the movable intestinal segment; the stitches were passed transdermally to the outside. The design of the laparoscopic anastomosis did not differ from that of the open technique proposed by Jannie Louw. At the final stage of the trial, the researchers assessed immediate and long-term results after this new surgical intervention. Results. Laparoscopic intervention for small bowel atresia of type I was performed on the second day of life. The surgery lasted for 75 minutes. No complications were registered during it. The enteral nutrition was started after the decrease in the rate of losses in the gastric tube lower than 10 ml / kg / day. It was on day 3 after the surgery. A gradual increase in the volume of feeding promoted patient’s transfer to the full enteral nutrition on day 7 after the surgery. Next day, the baby was discharged from the hospital. Early follow-up revealed no any signs of anastomosis failure. One-year follow-up revealed no signs of impaired intestinal transit too. Conclusion. It seems that the care of small bowel atresia has taken a significant step forward. Anastomoses constructed laparoscopically in such patients are not only a possible option, they have demonstrated their effectiveness and safety as well.

Continuous Feedings Are Not Associated With Lower Rates of Gastroesophageal Reflux When Compared With Bolus Feedings.

Gastroesophageal reflux disease is common in children with gastrostomy tubes. Clinicians often transition to continuous feedings in an attempt to reduce reflux burden, though there is limited data to support this practice. In this retrospective study, we analyzed 24-hour multichannel intraluminal impedance with pH studies in 18 children with gastrostomy tubes receiving exclusive enteral nutrition with a combination of daytime bolus and overnight continuous feedings. There were no significant differences in the rate of reflux (reflux events per hour) between no feeding, bolus feeding, and continuous feeding periods overall or stratified by prior fundoplications (P > 0.40). After adjusting for age, BMI, feeding rate, and feeding volume in multivariate analysis, there were no significant differences in the risk of reflux between different feeding periods. These results suggest that continuous feedings may not offer a significant advantage in reducing reflux burden.

Higher load operation by adoption of ethanol fermentation pretreatment on methane fermentation of food waste

The study aims to examine whether ethanol fermentation pretreatment (EP) of food waste can contribute to high load operation on methane fermentation using an anaerobic membrane bioreactor (AnMBR). The hydraulic retention time was reduced stepwise from 20 to 5 days to increase the load by increasing the feeding volume. The corresponding organic loading rate (OLR) ranged from 6.6 to 26.5 g-COD/L/day. The control series (without pretreatment) was operable to an OLR of 8.8 g-COD/L/day versus 26.5 g-COD/L/day for the EP series. In the control series, the major volatile fatty acid (VFA) produced by acidogenesis in the reactor was propionic acid because based on Gibbs free energy variations for the methane conversion, acetic acid conversion was not as easy as from propionic acid as from ethanol in the EP series. EP proved effective in avoiding VFA accumulation and subsequent decreased pH. Therefore, EP significantly improves AnMBR performance.

Preparation of anion exchange membrane by efficient functionalization of polysulfone for electrodialysis

In this study, a chloromethylated polysulfone with controlled degree of chloromethylation (DCM) was synthesized for the preparation of anion exchange membranes (AEMs). The reported method avoided using the hazardous chemicals chloromethyl ether but achieved the same high DCM (up to 1.95) under mild experimental conditions. Various process parameters, including reaction time and temperature, solvent type and volume, and catalyst feeding mode and volume, were discussed to demonstrate how a relatively high DCM could be achieved through this process. AEMs with varied DCM were prepared and their performances were characterized. The reported AEM-1.95 possessed better properties as a result of the high molality of chloromethyl groups, such as higher ion exchange capacity and ionic conductivity, better thermal stability and alkaline stability, as well as better mechanical properties. Additionally, electrodialysis (ED) experiments were conducted to determine the feasibility of AEMs in practical applications. Results showed that the AEM prepared by higher DCM exhibited better desalination properties and lower energy consumption. The desalination rate of AEM-1.95 could be up to 94.5% and the energy consumption was only 7.5 kWh/kg. All the results demonstrate that the proposed route for efficient and non-toxic fabrication of CMPSF with high DCM exhibits significantly potential and may be a promising candidate for the preparation of AEMs with high performances.

TECHNICAL ASSESSMENT OF GAMMA-AMINO BUTYRIC ACID (GABA) PRODUCTION FROM RICE BRAN

This research focused on technical assessment of GABA production from rice bran through fermentation by Lactobacillus brevis. Influence of operating pressure on separation of GABA by nanofiltration membrane was investigated and 4 bar was suitable for the nanofiltration process. The purification of GABA by nanofiltration with constant feed volume was carried out and purity of GABA reached 4.8 folds, compared to feed, at 5 volumes of added water. At 40 of concentration factor in concentration of GABA solution by nanofiltration with full recycle of retentate, content of GABA reached 49.8 g/L. The production of GABA from defatted rice bran at pilot scale was carried out at 1,000 L/batch (equal to 200 kg of rice bran) of fermentation. Estimation of mass balance showed that, with 200 kg of defatted rice bran, 7.0 kg of GABA powder was obtained. Results indicated that, it is potential to produce GABA from rice bran through the fermentation by Lactobacillus brevis.

Postoperative Feeding Guidelines Improve Outcomes in Surgical Infants.

Early introduction of enteral nutrition (EN) in postoperative infants improves intestinal adaptation, reducing the risk of intestinal failure-associated liver disease (IFALD). Our objective was to determine whether guideline use reduces feeding variability and improves outcomes in the neonatal intensive care unit (NICU). In a cohort study, surgical infants at risk for IFALD were evaluated pre and post implementation of feeding guidelines at 2 NICUs. A total of 167 guideline infants (2013-2018) were compared with 242 historical controls (2007-2013). Adherence was measured with timing and volume of initial postoperative feed. Primary outcomes were IFALD incidence and time to reach 50% and 100% of energy from EN. Secondary outcomes were parenteral nutrition (PN) days, postoperative necrotizing enterocolitis (NEC), central line-associated bloodstream infection (CLABSI), and length of stay (LOS). Moderate IFALD decreased from 32% to 20% (P = .005) in the guideline group. Time to achieve 50% and 100% energy from EN was decreased from medians of 8 to 5 and 28 to 21 days, respectively (P < .001). There was an overall decrease in PN use from 41 to 29 days (P = .002), CLABSI incidence from 25% to 5% (P < .001), and LOS from 70 to 53 days (P = .030). Once stratified by diagnosis, infants with NEC showed greatest improvement and reduction in IFALD from 67% to 42% (P = .045). With no difference in postoperative NEC (P = .464). Early standardized postoperative EN guidelines in intestinal-surgery infants was associated with improved outcomes, including faster achievement of feeding goals and reduced IFALD severity, especially in infants with NEC.

The effect of enteral bolus feeding on regional intestinal oxygen saturation in preterm infants is age-dependent: a longitudinal observational study

BackgroundThe factors that determine the effect of enteral feeding on intestinal perfusion after preterm birth remain largely unknown. We aimed to determine the effect of enteral feeding on intestinal oxygen saturation (rintSO2) in preterm infants and evaluated whether this effect depended on postnatal age (PNA), postmenstrual age (PMA), and/or feeding volumes. We also evaluated whether changes in postprandial rintSO2 affected cerebral oxygen saturation (rcSO2).MethodsIn a longitudinal observational pilot study using near-infrared spectroscopy we measured rintSO2 and rcSO2 continuously for two hours on postnatal Days 2 to 5, 8, 15, 22, 29, and 36. We compared preprandial with postprandial values over time using multi-level analyses. To assess the effect of PNA, PMA, and feeding volumes, we performed Wilcoxon signed-rank tests or logistic regression analyses. To evaluate the effect on rcSO2, we also used logistic regression analyses.ResultsWe included 29 infants: median (range) gestational age 28.1 weeks (25.1–30.7) and birth weight 1025 g (580–1495). On Day 5, rintSO2 values decreased postprandially: mean (SE) 44% (10) versus 35% (7), P = .01. On Day 29, rintSO2 values increased: 44% (11) versus 54% (7), P = .01. Infants with a PMA ≥ 32 weeks showed a rintSO2 increase after feeding (37% versus 51%, P = .04) whereas infants with a PMA < 32 weeks did not. Feeding volumes were associated with an increased postprandial rintSO2 (per 10 mL/kg: OR 1.63, 95% CI, 1.02–2.59). We did not find an effect on rcSO2 when rintSO2 increased postprandially.ConclusionsOur study suggests that postprandial rintSO2 increases in preterm infants only from the fifth week after birth, particularly at PMA ≥ 32 weeks when greater volumes of enteral feeding are tolerated. We speculate that at young gestational and postmenstrual ages preterm infants are still unable to increase intestinal oxygen saturation after feeding, which might be essential to meet metabolic demands.Trial registrationFor this prospective longitudinal pilot study we derived patients from a larger observational cohort study: CALIFORNIA-Trial, Dutch Trial Registry NTR4153.

Experimental study of ultrasonic rolling processing

The ultrasonic vibration device and the rolling pressure measurement device are added on the ordinary rolling equipment, which form the ultrasonic rolling equipment. Due to the ultrasonic impact, ultrasonic rolling processing can obtain better surface quality and surface reinforcement than ordinary rolling processing. The experimental results show that the process parameters such as rolling pressure, rolling speed and feed volume effects obviously on the surface roughness and surface micro-hardness of the work piece ultrasonic rolled. In ultrasonic rolling processing, a relatively small rolling pressure can be used to obtain satisfactory processing results, avoiding the surface defects caused by large rolling pressure. Ultrasonic vibration frequency is generally 20kHz. And the vibration amplitude is generally 20 μm. The right combination of process parameters and the use of coolant provide the best process results.

2784. Increased Frontal Lobe Volume and Density in Macaques Exposed to Zika Virus In Utero

BackgroundIn utero Zika virus (ZIKV) infection causes birth defects and neurodevelopmental deficits in neonates. We reasoned that a translational macaque model of congenital ZIKV infection could define disease pathophysiology not possible in human clinical studies.MethodsWe inoculated 5 pregnant rhesus macaques with a Puerto Rican isolate of ZIKV (ZIKV-PRVABC59) during the first trimester, monitored infection with plasma viral RNA (vRNA) loads, and evaluated infants for birth defects and neurodevelopmental deficits during their first week of life. Assessments included neurobehavioral assessments, ophthalmic examinations, optical coherence tomography, electroretinography with visual evoked potentials, hearing examinations, brain magnetic resonance imaging (MRI), and tissue histopathological analyses.ResultsAll five pregnant dams demonstrated plasma viremia and seroconversion following ZIKV inoculation. One of the five pregnancies resulted in a stillbirth. All liveborn infants had decreased feeding volumes and weight gain compared with control infants. A comprehensive voxel-based morphometric comparison of ZIKV-exposed and control infant brain MRIs identified increased gray matter volume and density in the frontal lobe in the ZIKV-exposed infant group, which corresponds to the pharyngeal motor cortex responsible for coordinating swallowing. Ocular studies identified differences between ZIKV-exposed and control infants in retinal layer thicknesses (inner plexiform, outer nuclear layers, photoreceptor outer segment) and visual evoked potentials (increased amplitude of waveforms). While ZIKV vRNA was detected in the decidua of 2/5 pregnancies, no ZIKV vRNA was identified in infant tissues and none of the infants developed an anti-ZIKV IgM response.ConclusionIn utero ZIKV exposure resulted in decreased feeding volumes and weight gain, which may be related to the gray matter changes identified in the pharyngeal motor cortex. Changes in retinal layer thicknesses and increased cortical visual pathway waveform amplitude suggest vision may be impaired. These changes occurred despite the lack of evidence of vertical transmission, suggesting that ZIKV exposure without measurable vertical transmission affects fetal brain development.Disclosures All authors: No reported disclosures.