A meshless computational framework for studying cold spray additive manufacturing including large numbers of powder particles with diverse characteristics.

Cold spray (CS) has emerged as an appealing additive manufacturing (AM) technique for producing or repairing individual components or entire structures. Compared to fusion-based AM technologies, cold spray additive manufacturing (CSAM) offers distinct advantages in the fabrication of components, while avoiding some melting/solidification-related issues such as phase transformation and oxidation. It involves intricate processes that pose significant challenges for numerical modeling, particularly when simulating the entire process at a large scale. The smoothed particle hydrodynamics (SPH) method is highly suitable for handling large material deformations due to its Lagrangian and meshless nature. In this work, we develop an enhanced SPH method to conduct large-scale simulations of CSAM with different powder sizes, morphologies, and distributions. A modified material model has been incorporated to accurately capture the strain-rate hardening effects during the plastic stage. The computational scale is greatly improved by using a Message Passing Interface (MPI) based framework, enabling the simulation of approximately ten million SPH particles. To the authors' knowledge, this study marks the first attempt to numerically reproduce the entire process of CSAM with real powder sizes and distributions. Experimental data measured for a wide range of powder velocities are used to validate the simulation results and assess the prediction accuracy. Subsequently, we comparatively study the bonding mechanisms of powders with the same or different sizes, while also identifying a four-stage coating process. The effects of powder morphology on the bonding process are thoroughly investigated. A large-scale CSAM process is finally reproduced to demonstrate the capability of the present meshless scheme, and mechanisms of pore formation are analyzed, providing valuable insights for practical engineering applications.

Traveling waves shape neural population dynamics enabling predictions and internal model updating.

The brain generates predictions based on statistical regularities in our environment. However, it is unclear how predictions are optimized through iterative interactions with the environment. Because traveling waves (TWs) propagate across the cortex shaping neural excitability, they can carry information to serve predictive processing. Using human intracranial recordings, we show that anterior-to-posterior alpha TWs correlated with prediction strength. Learning about priors altered neural state space trajectories, and how much it altered correlated with trial-by-trial prediction strength. Learning involved mismatches between predictions and sensory evidence triggering alpha-phase resets in lateral temporal cortex, accompanied by stronger alpha phase-high gamma amplitude coupling and high-gamma power. The mismatch initiated posterior-to-anterior alpha TWs and change in the subsequent trial's state space trajectory, facilitating model updating. Our findings suggest a vital role of alpha TWs carrying both predictions to sensory cortex and mismatch signals to frontal cortex for trial-by-trial fine-tuning of predictive models.

Emphysematous pyelonephritis in a transplant kidney.

Emphysematous pyelonephritis (EPN) is a severe necrotizing infection of the kidney and its surrounding tissues. It is characterized by the production of gas within the kidney and perinephric structures. EPN often affects diabetic women but can also occur in nondiabetic patients who have ureteral obstruction and in immunocompromised patients. Herein, we report EPN in a 23-year-old woman who had a renal transplantation.

Effect of intralesional verapamil for treatment of Peyronie's disease: a randomized single-blind, placebo-controlled study.

PURPOSE: We aimed to assess the effect of intralesional verapamil on the treatment of Peyronie's disease. MATERIALS AND METHODS: This randomized study involved 80 patients. First, they were divided into two groups. The first group (case: 40 patients) received intralesional verapamil and the second group (control: 40 patients) local saline injection. They were followed about 24 weeks and evaluated for the size of plaques, plaque softening, reduction of pain and amelioration of penile deformity and erectile dysfunction (estimated by the International Index of Erectile Function) before and after treatment. RESULTS: Reduction of plaque size was seen in 17.5% of the case group and 12.8% of the control group (P: 0.755). Pain was reduced in 30% of the case group and 28.2% of the control group (P: 0.99). Curvature was decreased in 17.5% of the case group and 23.1% the control group (P: 0.586). Plaque softening was seen in 30% of the case group compared with 25.6% improvement in the control group (P: 0.803). Also we found 5% and 2.6% improvement in sexual dysfunction in the case and control groups, respectively. (P: 0.985). CONCLUSION: Although in some studies verapamil has been found to be effective in the treatment of Peyronie's disease, we did not find any improvement in comparison with the control group. Furthermore, larger scale studies are warranted to assess the effect of this drug on the treatment of Peyronie's disease.

Maternal erythropoietin in singleton pregnancies: a randomized trial on the effect of oral hematinic supplementation.

OBJECTIVE: Our purpose was to study the effect of hematinic supplementation on the maternal erythropoietin response during singleton pregnancy. STUDY DESIGN: In a randomized, double-blind trial 97 patients with a first-trimester hemoglobin level > or = 14.0 gm/dl received either iron and folic acid (hematinic group, n = 53) or a placebo (n = 44). Serial hemoglobin, hematocrit, and serum erythropoietin were recorded from maternal blood and from cord blood on delivery. Serum ferritin was measured in the first trimester, at 36 weeks' gestation, and in cord blood. RESULTS: In both groups (1) the mean hemoglobin was lower (p < 0.01) at 40 weeks' gestation than when first examined and (2) the mean serum erythropoietin was higher (p < 0.01). The mean serum ferritin was lower (p < 0.001) in both groups at 36 weeks' gestation than at presentation but higher (p = 0.04) in the hematinic group than in the placebo group. The mean hemoglobin and hematocrit were similar in the two groups until the third trimester but thereafter were higher (p < 0.05) in the hematinic group. The mean maternal serum erythropoietin was higher (p < 0.05) in the placebo group than in the hematinic group after 24 weeks' gestation. The mean cord blood hematologic values were similar in the two groups. CONCLUSION: Maternal serum erythropoietin increased during pregnancy, but this response was reduced in the third trimester in the hematinic-supplemented group.

Internal iliac artery ligation (IIAL) in obstetrics and gynaecology.

Internal iliac artery ligation is a highly effective method of stemming uterine haemorrhage which is grossly underused in obstetrics and gynaecology. Two cases of incessant haemorrhage at LSCS one presented which did not respond to uterine artery ligation. One case was associated with placenta accreta, the other with a lower segment tear. In both cases unilateral internal iliac artery ligation effected cessation of haemorrhage and permitted uterine conservation. The procedure was utilised in a further two cases to stem haemorrhage associated with uterine perforation and broad ligament haematoma after termination of pregnancy and pelvic haematoma secondary to a slipped uterine artery ligature following hysterectomy.

Cord blood erythropoietin, pH, PaO2 and haematocrit following caesarean section before labour.

We have investigated the relationship between erythropoietin (Epo) and pH, PaO2 and haematocrit in 100 cord blood samples obtained at Caesarean section prior to labour. Of 82 term (> 37 weeks) infants, 64 were appropriately grown (10th-90th centiles), and their mean cord serum Epo and cord blood Epo was 23 +/- 8 mU/ml (mean +/- SD). Strong inverse correlations were found between cord serum Epo and cord blood pH (r = -0.74; p < 0.0001), and between cord serum Epo and cord blood PaO2 (r = -0.55; p < 0.0001), but not between cord serum Epo and cord haematocrit (r = 0.02; p < 0.9). For the 18 preterm babies (gestation 32.4 +/- 4.1 weeks, birth weight 1,820 +/- 476 g), the Epo level was 36 +/- 8 mU/ml, which was not significantly greater than for the term babies. Strong inverse correlations were again found between Epo and pH (r = -0.87; p < 0.0001) and Epo and PaO2 (r = -0.69; p < 0.002). Babies from complicated pregnancies (intra-uterine growth retardation, pre-eclampsia, antepartum haemorrhage, diabetes mellitus and fetal distress) tended to have higher Epo levels. Thirteen babies had Epo levels > 40 mU/ml, and 11 (85%) of these required neonatal intensive care. Cord serum Epo correlates better with oxygen tension and pH at birth than with fetal growth and haematocrit, which are measures of chronic stress to the fetus.

Breast milk beta-glucuronidase and exaggerated jaundice in the early neonatal period.

Breast-feeding is associated with jaundice in the early neonatal period. Previous work has shown levels of the enzyme beta-glucuronidase in maternal breast milk to be related to infant serum bilirubin on postnatal day 21. Our aim was to establish if there was a correlation between the level of breast milk beta-glucuronidase and the degree of early (first week) neonatal hyperbilirubinaemia. A study of 55 mother and baby pairs showed that breast milk beta-glucuronidase levels had no relationship with the level of infant serum bilirubin between postnatal days 3 and 6. Breast milk beta-glucuronidase does not directly account for the early neonatal jaundice seen in breast-fed babies.

Thyroid function studies in the nephrotic syndrome.

Total serum and urinary thyroxine (T4), triiodothyronine (T3), and thyroxine-binding globulin (TBG) as well as serum free T4, thyroid-stimulating hormone (TSH), and T3 resin uptake (T3RU) were measured in seven patients with the nephrotic syndrome. The nephrotic syndrome was defined by proteinuria exceeding 3 g/24 h. All patients were clinically euthyroid. Most values for total serum T4, free T4, T3, T3RU, TBG, and TSH were within normal limits. However, the mean serum T3 and TBG values were significantly lower in patients compared with the control group. The values (mean +/- 2 SD) for urinary T4 were 24.3 +/- 20.3 in the patient group and 1.5 +/- 0.7 microgram/24 h in the control group. Urinary T3 values for patients and the control group were 2100 +/- 856 and 848 +/- 253 ng/24 h respectively. Urinary TBG was 2.1 +/- 1.8 mg/24 h in the patients and undetectable in the control group. There was no correlation between daily urinary T3 and T4 and urinary TBG. There was a weak correlation between daily urinary protein excretion and urinary T4 (r = 0.5).

Esophageal motor function in Graves' disease.

Esophageal motor function was studied in 10 patients with untreated Graves' disease and 15 healthy volunteers who served as controls. A noncompliant recording system with a triple-lumen assembly was used. Resting upper- and lower-esophageal-sphincter pressures, amplitude, duration, and velocity of peristaltic contractions in the body of the esophagus, and the number of repetitive and simultaneous contractions were measured. There was no significant difference in peristaltic amplitude and duration between the controls and the patients with Graves' disease. However, there was a significant increase in velocity of contractions in Graves' disease as compared with controls. On restudy of 5 patients who became euthyroid after treatment with 131I, all the measured parameters were unchanged except for velocity of the peristaltic contractions. The value for this measurement decreased essentially to the same as that found in the control subjects. It is concluded that: (1) thyrotoxicosis increases the propagation velocity of esophageal contraction, and (2) thyroid hormones may play a physiologic role in the control of esophageal motor function.