Defect Reduction Research Articles

Uncertainty Quantification of Ride Comfort Based on gPC Framework for a Fully Coupled Human–Vehicle Model

We investigated the stochastic response of a person sitting in a driving vehicle to quantify the impact of an uncertain parameter important in controlling defect reduction in terms of ride comfort. Using CarSim software and MATLAB/Simulink, we developed a fully coupled model that simulates a driving vehicle combined with an analytical nonlinear human model. Ride comfort was evaluated as a ride index considering the frequency weights defined in BS 6841. Additionally, to investigate the uncertainty of the ride index, a framework for calculating the ride index was proposed using the generalized polynomial (gPC) method. Further, sensitivity analysis of the ride index was performed for each uncertainty parameter, such as stiffness and damping. The results obtained through the gPC method were in good agreement with those obtained via Monte Carlo simulation (MCS) and were excellent in terms of computation time without a loss of numerical accuracy. Through in-depth investigation, we found that the stochastic distribution of the ride index varies differently for each uncertain parameter in the human model. By comparing linear and nonlinear human models, we also found that the nonlinearity of the human model is an important concern in the stochastic estimation of ride comfort.

Limb Salvage in Diabetic Patients With Combination of Radical Excision, Antibiotic Impregnated Bone Cement, and External Fixator Application

In patients with diabetes, foot ulceration is a major cause of morbidity and hospitalization. The combination of deep ulcers and underlying osteomyelitis in patients with diabetes frequently leads to chronic nonhealing foot ulcers. These patients have often ended up with amputation. From 2003 to 2017, 17 of 175 diabetic patients (11 males and 6 females, 37 to 82 y old) were treated for diabetic foot and presented with complaints of ulceration, osteomyelitis, and foot gangrene. Magnetic resonance imaging–guided necrotic tissue debridement was performed, after the placement of antibiotic-impregnated bone cement, and soft tissue defect reduction was performed with an external fixator. Approximately 4 weeks later, polymethylmethacrylate was removed, and then the external fixator was removed after the soft tissue defect was closed. No patients had recurrent ulceration or osteomyelitis seen on radiographs up to their latest follow-up. There was pin tract infection in 2 patients who were treated with oral antibiotics and wound dressings. All patients have a fibrous union in the metatarsophalangeal joint. Compared with other radical techniques such as amputation, amputation, and long-term wound dressings, salvage of limbs with an external fixation can be used in selected patients who have osteomyelitis and soft tissue defects after debridement. Level of Evidence: Diagnostic level III—nonrandomized controlled cohort study.

Study of Defects in 4H-SiC Epitaxy at Various Buffer Layer Growth Conditions

Buffer layer optimization is a critical technique to mitigate defect propagation from substrate to epilayer, reduce stress, and prevent generation of ingrown defects. In the present study, the impact of dopant transition from substrate to the buffer layer on various epilayer defects was investigated. It was found that a ramped transition of the dopant concentration from substrate to buffer layer is beneficial for reduction of basal plane dislocations in the epilayer compared to an abrupt doping transition. This reduction of defects can be attributed to reduced stress at the substrate-to-buffer layer transition. Tests on buffer layer growth rates also revealed that higher growth rates reduce BPDs (basal plane dislocations) in the epilayers. We believe that BPD conversion in epilayers grown at higher growth rates is energetically more favorable than the conversion at slower growth rates resulting in the observed reduced BPDs at higher growth rates.

Reduction in edge beading defects using two-axis spin coating technology: an analytical, numerical, and experimental study

Reduction in edge beading defects using two-axis spin coating technology: an analytical, numerical, and experimental study

Production Quality Control as An Important Factor to Meet Buyer Quality Standards at The Garment Company PT. Sukabumi Single Estuary

The objectives of this study were achieved through the use of qualitative descriptive analysis, quantitative statistical ana-lysis, and quality control. To meet the quality target set by the Buyer, which is below 1.9%, it is necessary to know how many types of defects are found in the Finishing section and in the Final Inspection and how to reduce defects through the use of control strategies and methods applied by PT. Single Estuary. The data for this study comes from the statistics of production and damage to the Finishing department between May and August. Based on the findings of the study, it can be said that the implementation of quality control in this enterprise has been carried out quite successfully, with a noticeable improvement and a good quality improvement and is worthy of appreciation. These results show the seriousness or level of commitment of the management of PT. Muara Tunggal to continuously improve the quality according to the requests of buyers or buyers. The reduction in defects was first seen in early September 2022 with a defect rate of around 1.4%. Regarding the recommendations that can be made based on the findings, these include selecting raw materials according to Buyer's standards, hiring skilled labor, maintaining strict work ethics, providing training to employees to improve their skills, maintaining machines regularly, and improving neatness, comfort, and a safe workplace.

Microstructure of NbMoTaTiNi Refractory High-Entropy Alloy Coating Fabricated by Ultrasonic Field-Assisted Laser Cladding Process

Refractory high-entropy alloys (RHEAs) contain alloying elements with a high melting point, promising high-temperature applications due to their unique properties. In this work, laser cladding is used to prepare RHEAS based on NbMoTaTiNi. At the same time as laser cladding, the ultrasonic field is used, and then the microstructural characteristics, grain size, residual stress, wear, and hardness of the coating are evaluated. The results show that the coating is biphasic and includes the γ (Ni) and NbMoTaTiNi phase. The NbMoTaTiNi phase had a uniform distribution throughout the coating when the ultrasonic field was applied, so that when the ultrasonic field was not used, the NbMoTaTiNi powder, in addition to spreading uniformly, had the un-melting of large particles. This caused an increase in the residual tension of the coating. The conversion of columnar grains to the equiaxed, and the reduction in structural defects, were other characteristics of using the ultrasonic field. The formation of equiaxed grains with zigzag grain boundaries reduced the friction coefficient, wear volume loss, and the wear rate of the coating applied with ultrasonic.

Effect of Sodium Stearate on the Microstructure and Hydration Process of Alkali-Activated Material

In response to the high water sorptivity of alkali-activated slag–red mud–steel slag cementitious material (AASRSS), water and aggressive ions are easily transferred to the interior of cementitious materials, which poses a significant threat to their durability. In order to limit the transfer of moisture and aggressive ions to the interior of AASRSS, sodium stearate (NaSt) was utilized in this paper to reduce its water sorptivity. The aim of this study was to elucidate the role of NaSt in the AASRSS system. The changes in the compressive strength and water sorptivity of AASRSS mortar were tested by mixing different amounts of NaSt into the mortar. The changes in the hydration process and microstructure of AASRSS after mixing with NaSt were analyzed by using the test methods of the isothermal calorimetry, resistivity, SEM and MIP. The results showed that NaSt plays an important role in the pore structure characteristics of AASRSS and that the use of NaSt significantly reduces its water sorptivity. The improvement in the water sorptivity was caused by two main mechanisms, namely the optimization of the pore structure (reduction in defects of the microstructure and alteration of pore size distribution) and the introduction of a hydrophobic film on the pore surface. The addition of NaSt did not change the type of AASRSS hydration product, but it inhibited the hydration reaction, leading to a reduction in the hydration product. The combination of the increased porosity and reduced hydration products mainly accounts for the decrease in the compressive strength of AASRSS due to NaSt.

Mitochondrial dysfunction in glaucomatous degeneration.

Glaucoma is a kind of optic neuropathy mainly manifested in the permanent death of retinal ganglion cells (RGCs), atrophy of the optic nerve, and loss of visual ability. The main risk factors for glaucoma consist of the pathological elevation of intraocular pressure (IOP) and aging. Although the mechanism of glaucoma remains an open question, a theory related to mitochondrial dysfunction has been emerging in the last decade. Reactive oxygen species (ROS) from the mitochondrial respiratory chain are abnormally produced as a result of mitochondrial dysfunction. Oxidative stress takes place when the cellular antioxidant system fails to remove excessive ROS promptly. Meanwhile, more and more studies show that there are other common features of mitochondrial dysfunction in glaucoma, including damage of mitochondrial DNA (mtDNA), defective mitochondrial quality control, ATP reduction, and other cellular changes, which are worth summarizing and further exploring. The purpose of this review is to explore mitochondrial dysfunction in the mechanism of glaucomatous optic neuropathy. Based on the mechanism, the existing therapeutic options are summarized, including medications, gene therapy, and red-light therapy, which are promising to provide feasible neuroprotective ideas for the treatment of glaucoma.

High temperature annealing on vertical p-n junction p-NiO/n-β-Ga2O3 nanowire arrays for high performance UV photodetection

The authors of this article reported the effects of annealing on performance of GLAD synthesized vertical p-NiO/n-β-Ga2O3 heterostructure (HS) nanowire (NW) arrays based UV photodetector (PD). The authors further investigated the structural, optical and electrical properties at various annealing temperatures (200 °C, 400 °C, 600 °C, 800 °C, and 1000 °C) including as deposited sample to find the best sample for UV PD application. The XRD analysis showed improved crystallinity and least dislocation density and micro strain values for 800 °C sample. However, the sample degrades beyond 800 °C owing to crystallographic defects that are formed at higher annealed temperatures. Furthermore, the photoluminescence analysis showed that the defect levels decreased at 800 °C annealed temperature which was also analogous to the XPS analysis. The FE-SEM analysis also showed the impact of high temperature annealing (800 °C) with increased in nanowire diameter and length. The surface roughness was also found to be smoother for 800 °C sample from TEM analysis. Moreover, the fabricated 800 °C annealed vertical p-NiO/n-β-Ga2O3 axial NW arrays based UV PD showed the largest responsivity (Rλ) of 940 A/W as compared to all the samples. Also, the 800 °C annealed UV PD exhibited fast response speed along with rise time and fall times of 0.32 s and 0.49 s respectively. The superior performance of 800 °C sample was ascribed to the large grain size, defect reduction and improvement of interference quality.

Suppressed polaronic conductivity induced sensor response enhancement in Mo doped V2O5 nanowires

In this paper, we show the direct correlation between the suppression of the polaronic oxygen vacancy defect (Vo) density and gas sensor response of 1 at. % Mo-doped V2O5 nanowires (MVONWs). Doping 1 at. % Mo5+ leads to substitution at the V5+ site in V2O5 nanowires (VONWs) and, therefore, reduction in Vo defects. This, in turn, affects the charge carrier hopping sites and, subsequently, enhances the sensor response at lower temperatures (<320 °C). The Mo5+ dopants lead to the lowering of Fermi energy (EF) toward valence band maxima due to the reduced Vo donor density. The polaron suppression is confirmed with the activation energy of polaron hopping, increasing from 195 to 385 meV in VONWs and MVONWs. As a result, the response to ethanol gas enhanced as the depletion width is widened for the given cross section of the nanowires. This may lead to a large depletion controlled cross-sectional area and, therefore, better sensitivity. At about 350 °C, VONWs show a change in the slope of resistance vs temperature (MIT), which is not observed in the case of MVONWs. This is attributed to the presence of the enhanced non-stoichiometry of V ion resulting in metallic behavior and accompanied by a sudden rise in the sensor response at this temperature. Moreover, the absence of MIT may be attributed to the lack of such a sudden rise in the response in MVONWs.

Guided Bone Regeneration Effects on Bone Quantity and Outcomes of Dental Implants in Patients With Insufficient Bone Support: A Single-Center Observational Study.

Background Guided bone regeneration (GBR)is used to influence on stabilization of dental implants in patients with insufficient bone quantity and anatomical problems.But many studies using GBR resulted in divergent results according to the efficiency of new bone quantity formation and implant survival. This research aimed to study the effects of GBR on the increase of bone quantity and short-term stabilization of dental implants in patients with insufficient bone support. Methodology The study included 26 patientsthat underwent the procedure for 40 dental implants from September 2020 to September 2021. In each case, the vertical bone support was intraoperatively measured, through the MEDIDENT Italia paradontal millimetric probe (Medident Italia, Carpi, Italy). The vertical bone defect was considered when the mean vertical depth between the abutment junction and the marginal bone wasgreater than 1mm up to 8mm. In the group with the presence of the vertical bone defect, GBR technique was used duringthe procedure of dental implantsrealized with synthetic bone graft, resorbable membrane, and platelet-rich fibrin (PRF), and the group was considered the study (GBR) group. The group of patients with no vertical bone defects(less than 1mm) and no need for any GBR technique usewas considered the control (no-GBR) group. The bone support was evaluated again intraoperatively after six months in both groups when the healing abutmentswere positioned. The vertical bone defect for each group in baseline and after six months is presented as mean±SD and compared using a t-test. A t-test for Equality of Means was used to calculate the mean depth difference (MDD) between baseline and six months values in each group (GBR and no-GBR) and also between both groups. P-value ≤ 0.05 is considered statistically significant. Results Overall 40 dental implants were placed, 20 of them were included in the GBR group and 20 in the no-GBR group. In the GBR group, a statistically significant greater mean vertical bone defect in baseline (day 1), compared to the no-GBR group was found (-4.46±2.76 vs -0.27±0.22; MDD = -4.19 [-5.44 to -2.94] p<0.001). At six months of follow-up in the GBR group, a new bone around the implant was formed, presenting a significantly lower bone defect compared to the baseline measure (-0.39±0.43 vs -4.46±2.76; MDD = -4.07 mm [-5.37 to -2.78]p<0.001). In six months, no statistically significant difference between GBR and no-GBR group in bone support was found (-0.39±0.43 vs -0.27±0.22; MDD = -0.19 [-0.40 to -0.03] p=0.10). In each group, only one implant failure was observed. Conclusions The use of GBR showed an important reduction of vertical depth defect between healing abutment and marginal bone predisposing similarshort-term stability and survival of dental implants. The use of GBR techniques could be essential in the stabilization of dental implants in patients with insufficient bone support.

Quantitative and qualitative characterization of the damage, deformation mechanisms, and failure modes of a nickel-based GH3536 alloy prepared via laser powder bed fusion after various heat treatments

Nickel-based alloys prepared via laser powder bed fusion (LPBF) exhibit high strength and low elongation during tensile testing at room temperature. To optimize the performance, hot isostatic pressing (HIP) and HIP with heat treatment (HT), that is, HIP + HT were applied to the deposited GH3536 samples. The plasticity and elongation of the post-treated Ni-based alloy are clearly improved; this can be attributed to the change in micromorphology from columnar grains to equiaxed grains, as well as to the reduction in defects and internal stresses. It is experimentally confirmed that the characteristic grains and defects formed during the LPBF process caused the porosity of the deposited samples to change considerably during tensile testing. The increment is up to 12.3%, and the grain deformation rate of the deposited samples is minimal. The porosity increased by 1.4% for the HIP-ed GH3536 (i.e., after hot isostatic treatment) samples and by 5.4% for the (HIP + HT)-ed GH3536 (i.e., after hot isostatic pressing and heat treatment) samples during tensile testing. The results of electron backscatter diffraction characterization and grain statistics revealed that the average grain diameter of the HIP-treated samples increased the most (>25 μm) during the tensile process, and the samples exhibited the best deformation ability. Microstructural characterization showed that the (HIP + HT)-ed samples contained a large number of “small equiaxed grains” (i.e., grains with the grain size are always less than 50 μm in the whole process of deformation). According to the grain deformation behavior analysis, these small equiaxed grains coordinated the deformation process, resulting in the (HIP + HT)-ed samples exhibiting the best deformation coordination ability and deformation mechanism.

Thermal Decomposition and Solidification Characteristics of BFFO

A novel energetic material, Bifurazano [3,4-b: 3′,4′-f] furoxano [3″,4″-d] oxacyclo-heptatriene (BFFO), has been investigated regarding two aspects, namely its thermal decomposition and solidification characteristics. The DSC curves indicate that the peak temperature of BFFO decomposition process is 271.1 °C under the static pressure of 2 MPa and the volatility of BFFO at 120 °C is significantly lower than that of TNT, DNAN and DNTF. The solidification curve indicates that the solidification of BFFO is a basic linear uniform solidification process, which is obviously different from that of TNT, DNAN and DNTF. In addition, the facet of BFFO appears much smoother and fewer defects are observed in the solidified body after solidification via CT and SEM. The reduction in solidification defects also further improves the mechanical properties of BFFO, with significant improvements in compressive and tensile strength compared to DNTF, DNAN and TNT. In summary, BFFO is a potential melt-cast carrier explosive with excellent thermal stability, solidification characteristics and mechanical properties.

Novel Codoping Moiety to Achieve Enhanced P‐Type Doping in GaN by Ion Implantation

Codoping of gallium nitride for improved acceptor ionization has long been theorized; however, reduction to practice proves difficult via growth. Herein, implementation of codoping via ion implantation and symmetric multicycle rapid thermal annealing utilizing magnesium codoped with silicon or oxygen is demonstrated. Results show enhanced photoluminescence with both donor species but with an order of magnitude greater increase with concurrent p‐type hall for codoping with oxygen. Furthermore, the addition of nitrogen to balance stoichiometry suppresses defect photoluminescence signals. The incorporation of the donor and nitrogen demonstrates defect reduction beyond magnesium, only implants despite the additional implant dose and resultant damage with coimplantation. The enhanced hole concentrations evident with oxygen incorporation reveal important considerations for device design given unintentional doping during growth and future incorporation of ion implantation capabilities.

Crack Inhibition and Performance Modification of NiCoCr-Based Superalloy with Y2O3 Nanoparticles by Laser Metal Deposition.

A new precipitation strengthening NiCoCr-based superalloy with favorable mechanical performance and corrosion resistance was designed for ultra-supercritical power generation equipment. The degradation of mechanical properties and steam corrosion at high temperatures put forward higher requirements for alternative alloy materials; however, when the superalloy is processed to form complex shaped components through advanced additive manufacturing techniques such as laser metal deposition (LMD), hot cracks are prone to appear. This study proposed that microcracks in LMD alloys could be alleviated with powder decorated by Y2O3 nanoparticles. The results show that adding 0.5 wt.% Y2O3 can refine grains significantly. The increase in grain boundaries makes the residual thermal stress more uniform to reduces the risk of hot cracking. In addition, the addition of Y2O3 nanoparticles enhanced the ultimate tensile strength of the superalloy at room temperature by 18.3% compared to original superalloy. The corrosion resistance was also improved with 0.5 wt.% Y2O3, which was attributed to the reduction of defects and the addition of inert nanoparticles.

The Functional Relationship between NADPH Thioredoxin Reductase C, 2-Cys Peroxiredoxins, and m-Type Thioredoxins in the Regulation of Calvin-Benson Cycle and Malate-Valve Enzymes in Arabidopsis.

The concerted regulation of chloroplast biosynthetic pathways and NADPH extrusion via malate valve depends on f and m thioredoxins (Trxs). The finding that decreased levels of the thiol-peroxidase 2-Cys peroxiredoxin (Prx) suppress the severe phenotype of Arabidopsis mutants lacking NADPH-dependent Trx reductase C (NTRC) and Trxs f uncovered the central function of the NTRC-2-Cys-Prx redox system in chloroplast performance. These results suggest that Trxs m are also regulated by this system; however, the functional relationship between NTRC, 2-Cys Prxs, and m-type Trxs is unknown. To address this issue, we generated Arabidopsis thaliana mutants combining deficiencies in NTRC, 2-Cys Prx B, Trxs m1, and m4. The single trxm1 and trxm4 mutants showed a wild-type phenotype, growth retardation being noticed only in the trxm1m4 double mutant. Moreover, the ntrc-trxm1m4 mutant displayed a more severe phenotype than the ntrc mutant, as shown by the impaired photosynthetic performance, altered chloroplast structure, and defective light-dependent reduction in the Calvin-Benson cycle and malate-valve enzymes. These effects were suppressed by the decreased contents of 2-Cys Prx, since the quadruple ntrc-trxm1m4-2cpb mutant displayed a wild-type-like phenotype. These results show that the activity of m-type Trxs in the light-dependent regulation of biosynthetic enzymes and malate valve is controlled by the NTRC-2-Cys-Prx system.

Comparison of Clinical Parameters between the Treatment of Infrabony Defects with and without Concentrated Growth Factors in Open Flap Debridement: In vivo Study

Introduction:This study aimed to clinically and radiographically compare the regenerative effects of open flap debridement alone and in combination with concentrated growth factor (CGF) in the treatment of periodontal three-walled infrabony defects.Materials and Methods:Fifteen patients who fulfilled the inclusion criteria were selected from the outpatient department of periodontology. A split-mouth study was conducted and bilateral or contralateral defects were divided into two groups using computer-generated randomisation sheets-control site (open flap debridement alone) and case site (open flap debridement with CGF). Clinical parameters were assessed at baseline, 1 month, 3 months and 6 months. Radiographic parameters were assessed at baseline and 6 months postoperatively.Results:At 3 and 6 months postoperatively, the test group showed statistically significant improvement in clinical parameters as compared to the control group. At 6 months postoperatively, the test group showed improved bone fill as compared to the control group.Conclusion:Present study indicates that CGF, as a biological material has the property to enhance wound healing and result in mean pocket depth reduction of periodontal infrabony defects. In addition, long-term, multicentered randomised, controlled clinical researches will be required to better understand the clinical and radiographic effects of CGF on periodontal regeneration.

THE APPLICATION OF AN ENAMEL MATRIX PROTEIN (EMDOGAIN) IN REGENERATIVE PERIODONTAL THERAPY. CLINICAL SERIES

Objectives: The purpose of this clinical series is to present indications for regenerative therapy with EMD. Materials and Methods: The study included 53 patients with osseous defects from 7-15mm’s in depth. Each patient understood that the procedures were not within the normal treatment due to the severity of the defects but opted to accept treatment. Along with EMD each defect also had freeze fried demineralized bone placed in the defect as well. Results: Reentry of the original defects was undertaken at approximately 1 year after surgery. It was noted that for the most part significant improvement was noted in almost all defects. Exact improvement of defects was not calculated. In several cases 10-year reentry was undertaken and in fact further reduction in defects were noted. It could not be determined at any time over the 10-year period that the reduction in pocket depth was in fact bone as no histology was ever taken to verify what the defects were filled with. Conclusions: Clinical studies have indicated that treatment with EMD with freeze dried demineralized bone positively influences regenerative periodontal therapy.

Unexpected Behavior in Thermal Conductivity of Confined Monolayer Water

Monolayer water can be formed under extreme confinement and will present distinctive thermodynamic properties compared with bulk water. In this work, we perform molecular dynamics simulations to study the thermal conductivity of monolayer water confined in graphene channels, finding an unexpected way of thermal conductivity of monolayer water dependent on its number density, which has a close correlation with the structure of water. The monolayer water is in an amorphous state, and its thermal conductivity increases linearly with the area density when the water density is low at first. Then, the thermal conductivity increases as the number density of water rises, which is attributed to the formation of a crystal structure and the reduction of crystal defects as the number of water molecules increases. After reaching the zenith, the thermal conductivity decreases rapidly owing to the formation of a wrinkle structure of monolayer water with excessive water molecules, which weakens the phonon dispersion. Moreover, we further investigate the remarkable effects of the channel height on both the structure and thermal conductivity of monolayer water. In summary, this study demonstrates the close connection between the thermal conductivity of monolayer water and its structure, contributing to not only expanding the understanding of the thermodynamic property of nanoconfined water but also benefiting the engineering applications for nanofluidics.

The impact of voluntary folate fortification of corn masa flour on US pregnancies complicated by neural tube defects

IntroductionIn 1996, the US Food and Drug Administration (FDA) mandated folic acid fortification for all enriched cereal grains. This resulted in a reduction of neural tube defect (NTD)–affected pregnancies. However, Hispanic women continued to be twice as likely to give birth to a child affected by NTD compared to non-Hispanic White women. Some hypotheses explaining this difference focus on cultural variation in dietary intake of cereal grains. In 2016, the FDA approved voluntary folic acid fortification for corn masa flour products to focus on the Hispanic diet staple. This study investigates rates of NTDs in predominantly Hispanic-populated zip codes before and after the voluntary fortification of corn masa flour with folic acid.MethodsNormal pregnancies and those complicated by NTDs between 1/1/2016 and 9/30/2020 were identified using ICD-9 and ICD-10 codes in an all-payor claims database. The post-fortification period began 12 months after the fortification recommendation. The US Census data was used to stratify pregnancies in predominantly Hispanic zip codes (≥ 75% of households) vs. non-Hispanic zip codes. The causal impact of the FDA’s recommendation was assessed by means of a Bayesian structural time series model.ResultsA total of 2,584,366 pregnancies were identified among females aged 15–50 years. Of these, 365,983 took place in predominantly Hispanic zip codes. Mean quarterly NTDs per 100,000 pregnancies did not significantly differ between predominantly Hispanic zip codes and predominantly non-Hispanic zip codes pre-FDA recommendation (184.5 vs. 175.6; p = 0.427), nor post-recommendation (188.2 vs. 185.9; p = 0.713). Rates of NTDs predicted to occur if no FDA recommendation had been made were compared to the actual rate post-recommendation: no significant difference was observed in predominantly Hispanic zip codes (p = 0.245) or overall (p = 0.116).ConclusionsRates of neural tube defects were not significantly reduced in predominantly Hispanic zip codes following the 2016 FDA approval of voluntary folic acid fortification of corn masa flour. Further research and implementation of comprehensive approaches to advocacy, policy, and public health are necessary to decrease preventable congenital disease rates. Mandatory rather than voluntary fortification of corn masa flour products may achieve more substantial prevention of neural tube defects in at-risk US populations.