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The direct laser melting of plasma sprayed bond coat has the possibility of improving the surface topography and can be done with Yb:YAG laser. In the current paper, laser melting of plasma sprayed coatings of 50 wt. % standard Amdry 963 (Ni24.5Cr6Al0.4Y) and 50 wt. % standard Amdry 9621 (Ni22Cr10AlY) was carried out by using 600 W continuous wave Yb:YAG laser. Notably, the obtained melted tracks were investigated from the upper surface plan view and transverse section. The topography, microstructure, phases, hardness, and compositions of the plasma sprayed coatings and laserremelted tracks were characterized by scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), roughness, and microhardness. By controlling the dependent laser variables (power density and interaction time), a different effect can be obtained for the plasma sprayed bond coating (NiCrAlY). Typically, the results obtained show that at low specific energies, four different distinct zones were observed. These specific energies were not sufficient to produce a uniform melting. The MCrAlY coatings remelted with high specific energies were characterized by completely uniform melting and cellular/dendritic microstructures. The melted coatings have high roughness reduction (1.2 μm) and low hardness (275 HV0.5) in comparison with plasma-sprayed coatings (10.5 μm) and (315 HV0.5) respectively. [ABSTRACT FROM AUTHOR]

Nanostructured TiO2 coatings were deposited on NiCrAlY coating by RF magnetron sputtering. NiCrAlY coating was deposited by sprayedplasma method on the Ni-base superalloy substrate. NiCrAlY layer work as the first protection layer while TiO2 nanocoatings as the second protection layer. Laser surface re-melting for coating layers by Nd-YAG laser was done. Hot corrosion test conducted for substrate after coating with both NiCrAlY and TiO2 nanocoating with and without laser surface remelting. Hot corrosion was tested by using a molten salt of Na2SO4-55 %V2O5 at 800 and 900 °C for 60 hours. The weight change measurements were performed to determine the cyclic hot corrosion kinetics of the coatings at a temperature of 800 and 900 °C. The microstructural features, surface topography, and phase composition were characterized by FE-SEM, EDS, AFM, and XRD. The results of FE-SEM indicate that some porosities, cracks, and unmelted powder can be seen on the surface of samples for plasma spraying and RF sputtering of NiCrAlY coatings. After the laser surface remelting of coatings, it can be observed the absence of porosity and crack with enhanced surface properties. The roughness decreases after laser remelting. Hot corrosion tests indicate that the plasma-sprayed NiCrAlY coating can significantly lower the hot corrosion resistance than coating two layers by nanocoating of TiO2 by RF sputtering with laser remelting. The improvement owing to the formation of extensive amounts of the protective oxide of NiO, Al2O3, Cr2O3, Y2O3, and NiCr2O4 spinal generated on the surface. [ABSTRACT FROM AUTHOR]

Abstract Background Distinguishing the recent introduction of quinolone resistant gonococci into a population from diversification of resistant strains already in the population is important for planning effective infection control strategies. We applied molecular evolutionary analyses to DNA sequences from 9 housekeeping genes and gyrA, parC and porB of 24 quinolone resistant N. gonorrhoeae (QRNG) and 24 quinolone sensitive isolates collected in Israel during 2000–2001. Results Phylogenetic and eBURST analyses and estimates of divergence time indicated QRNG were introduced on 3 separate occasions and underwent limited diversification by mutation, deletion and horizontal gene transfer. Reconstruction of N. gonorrhoeae demography showed a slowly declining effective strain population size from 1976 to 1993, rapid decline between 1994 and 1999, and an increase from 1999 to 2001. This is partially attributable to declining gonorrhea case rates from 1973 to 1994. Additional contributing factors are selective sweeps of antibiotic resistant gonococci and increased transmission from sex workers. The abrupt decline in the mid-1990s heralded an increased incidence of gonorrhea from 1997 to the present. The subsequent increase in effective strain population size since 1999 reflects the increased gonococcal census population and introduction of quinolone resistance strains. Conclusion Our study demonstrates the effective use of population genetic approaches to assess recent and historical population dynamics of N. gonorrhoeae.

Objectives: This study aimed to assess the proportion of women who underwent postpartum evacuation and were histopathologically confirmed to have retained products of conception (RPOC), compare the reliability of histopathology and ultrasound (US) in determining the presence of RPOC, and assess the maternal complications associated with postpartum evacuation., Methods: A retrospective cross-sectional study was conducted on all women who delivered and had postpartum evacuation at a tertiary teaching hospital in Oman over 11 years from May 2009 to May 2020. The participants were divided into two groups based on their histopathology results. McNemar test was used to compare the sonographic results with the histopathological findings., Results: A total of 151 women were included in this study. The diagnosis of RPOC was confirmed in histopathological reports of 64 (42.4%) women (group 1) but not in 87 (57.6%) women (group 2). There was no significant difference between the two groups in maternal characteristics. Parameters of clinical presentation including fever and abdominal pain were significantly different between the two groups ( p = 0.026 and p = 0.028, respectively). Vaginal bleeding was not significantly different between the groups ( p = 0.255 ) . Pelvic US detected RPOC in 135 (89.4%) women whereas the histopathology confirmed it in 64 (42.4%) women ( p < 0.001). The sensitivity of US compared to histopathology in diagnosing RPOC was 98.4% (95% CI: 91.60-99.96) and the specificity was 17.2% (95% CI: 9.98-26.84). The overall diagnostic accuracy of US in detecting RPOC was 51.7%. Two (1.3%) women had hysterectomy as a result of the evacuation. Histopathology showed smooth muscle in 20 (13.2%) women. Significant bleeding during surgery occurred in 17 (11.3%) cases., Conclusions: Diagnosis of postpartum RPOC is challenging. Our results highlighted the complexity of diagnosing RPOC. Special training is needed for doctors to diagnose RPOC from transvaginal scans. A multicenter study in Oman with a larger sample size is recommended to confirm our findings., (The OMJ is Published Bimonthly and Copyrighted 2023 by the OMSB.)

The opioid epidemic in the United States has led to increases in hepatitis C virus (HCV) infection especially in rural communities. It is recommended that persons who inject drugs undergo screening and treatment. We initiated HCV screening and treatment within a mostly rural area of Pennsylvania by targeting medicated-assisted treatment (MAT) facilities and community events. Screening was conducted in 43 rural and 13 urban counties by a clinical team. At MAT facilities, the clinical team performed HCV screening between 4:30am and 1:00pm using the OraQuick HCV test free of charge. Participants with a positive screen were linked to treatment. In all, 3,051 screening tests were conducted among 2,995 unique participants, who were mostly white (2821, 94%) and from rural counties (2597, 87%). Participants were most frequently 25-to-34 years old (798, 27%). A total of 730 patients were HCV screen positive, 371 patients received an HCV RNA PCR test, and 272 were HCV RNA positive. Of them, 249 met with a healthcare provider, 102 initiated treatment, and 50 completed SVR testing, with 49 achieving SVR. Anti-HCV positivity was more frequent among MAT facility versus non-MAT patients (41% versus 5%) ( p  < .001). Non-MAT participants were more likely to begin treatment for HCV (91% [21/23] versus 30% [81/272]) and achieve SVR (71% versus 43%). In HCV screening and treatment among high-risk patients, substantial numbers of participants were lost at every point of care between screening and follow-up testing. Specific screening, treatment, and follow-up strategies for persons in rural communities may be needed., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2021 The Authors. Published by Elsevier Inc.)

Aim: To find out whether 50 g oral glucose challenge test (OGCT) is an effective screening test for all pregnant women between 24 and 28 weeks gestation., Method: A 50 g OGCT test was administered to 307 unselected women at 24-28 weeks of gestation. When venous plasma glucose (VPG) concentration after 1 h was >7.8 mmol/l, OGCT was positive. Women with a positive OGCT underwent 2 h 75 grams oral glucose tolerance test (OGTT) as a confirmatory diagnosis of GDM. When fasting and 2 h post 75 g OGTT values were >5.5 mmol/I and >8 mmol/l, respectively, women were considered diabetic., Results: We screened 307 women for GDM by OGCT. Total number of women with positive OGCT was 83 (27.03 %). In the low-risk group, total number of women with GDM was 9/168 (5.35 %) while the total number of women with GDM in the high-risk group was 14/139 (10.07 %). There was no significant difference with respect to the total number of women with GDM in the groups., Conclusions: A 50 g OGCT seems to be an effective screening test for both groups. More cases of GDM can be discovered when universal rather than risk-related screening is applied., Competing Interests: The authors declare that they have no conflicts of interest. Ethical approval All procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation (institutional and national) and with the Helsinki Declaration of 1975, as revised in 2008 (5). Informed consent Informed consent was obtained from all patients for being included in the study.

Aim: To compare obstetric and perinatal outcomes of early and late teenage pregnancies of Omani nulliparous women with singleton pregnancies cared for and delivered at a tertiary teaching hospital., Method: In this retrospective study, we reviewed obstetric and perinatal outcomes of early teenage pregnancies (14-16 years), (n = 20) delivered at Sultan Qaboos University Hospital, Muscat, Oman, between 1 July 2006 and 30 June 2013 and compared their outcomes with outcomes of late teenage pregnancies (17-19 years), (n = 287) delivered at the same hospital during same period., Results: When compared with late teenage pregnant women, early teenagers were found to have no significant differences in prevalence of very preterm delivery <32 weeks (P = 0.62), preterm rupture of membranes (P = > 0.99), and anemia (P = 0.34). When compared to late teenagers, early teenagers had similar cesarean sections rates (P = >0.99), instrumental delivery rates (P = 0.56) and spontaneous vaginal delivery rates (P > 0.99). Both groups had similar birth weights (P = 0.87), low birth weights, (P = 0.55), and very low birth weights babies (P = 0.56 %). Perinatal mortality rate was similar in both groups., Conclusion: We may conclude that early teenage pregnant Omani women are not at increased risk of obstetric and perinatal complication compared to older teenagers.

Objectives: The aim of this study was to assess the prevalence of gestational diabetes mellitus (GDM) and pregestational diabetes mellitus (PGDM) among pregnant women in Oman and compare their obstetric and perinatal outcomes., Methods: This retrospective study assessed the obstetric and perinatal outcomes of pregnant Omani women with GDM or PGDM who delivered at the Sultan Qaboos University Hospital in Muscat, Oman, between January 2009 and December 2010., Results: There were a total of 5,811 deliveries during the study period. Of the 5,811 women who gave birth, 639 women were found to have diabetes mellitus (11.0%). A total of 581 of the diabetic women had GDM (90.9%) and only 58 (9.1%) had PGDM. Women with PGDM had a significantly higher incidence of pre-eclampsia (P = 0.022), preterm deliveries (P <0.001) and Caesarean sections (P <0.001). Neonatal complications, such as respiratory distress syndrome (RDS), neonatal hypoglycaemia, neonatal jaundice and subsequent admission to a neonatal intensive care unit (NICU) were significantly higher for neonates born to mothers with PGDM compared to those born to mothers with GDM (P <0.001). The corrected perinatal mortality rates for women with PGDM and GDM were 34.5 and 13.7 per 1,000 live births, respectively., Conclusion: In this Omani cohort, women with PGDM were at higher risk of developing obstetric and perinatal complications such as pre-eclampsia, preterm delivery and Caesarean delivery compared to women with GDM. In addition, neonates who had mothers with PGDM had higher rates of RDS, neonatal hypoglycaemia, neonatal jaundice and admission to the NICU.

Objective: To study the obstetrical and perinatal outcomes of teenage Omani girls with singleton pregnancies at a tertiary teaching hospital., Methods: This is a retrospective case control study. We reviewed obstetric and perinatal outcomes of teenage nulliparous pregnant Omani girls with singleton pregnancies aged 14 to 19 years, delivered at Sultan Qaboos University Hospital, between 1 July 2006 and 30 June 2013. We compared their outcomes with outcomes of pregnant nulliparous Omani women with singleton pregnancies aged 20 to 25 years old delivered at the same hospital during the same period., Results: When compared with pregnant women (n=307), teenage pregnant girls (n=307) were found to have higher proportion of preterm delivery <32 weeks (7% vs. 3%, p=0.040), preterm pre-labor rupture of membranes (PPROM) (19% vs. 11%, p=0.005) and anemia (58% vs. 44%, p=0.005). Cesarean section rate was higher in women than teenager girls (20% vs. 10%, p=0.001). Teenager girls had lighter babies (mean weight ± standard deviation 2,750±690 vs. 2,890±480, p=0.020), incidence of very low birth weight babies (<1,500g) was higher in teenagers (3.9% vs. 0.3%, p=0.003), but perinatal mortality rate was similar in the two groups., Conclusion: Teenage pregnant Omani women are at increased risk of preterm delivery before 32 weeks gestation, PPROM, anemia, and delivering very low birth weight babies.

For over 100 years, large epidemics of meningococcal meningitis have occurred every few years in areas of the African Sahel and sub-Sahel known as the African meningitis belt. Until recently, the main approach to the control of these epidemics has been reactive vaccination with a polysaccharide vaccine after an outbreak has reached a defined threshold and provision of easy access to effective treatment but this approach has not prevented the occurrence of new epidemics. Meningococcal conjugate vaccines, which can prevent meningococcal carriage and thus interrupt transmission, may be more effective than polysaccharide vaccines at preventing epidemics. Because the majority of African epidemics have been caused by serogroup A meningococci, a serogroup A polysaccharide/tetanus toxoid protein conjugate vaccine (PsA-TT) has recently been developed. Results from an initial evaluation of the impact of this vaccine on meningococcal disease and meningococcal carriage in Burkina Faso have been encouraging. To review how the research agenda for meningococcal disease in Africa has been changed by the advent of PsA-TT and to define a new set of research priorities for study of meningococcal infection in Africa, a meeting of 41 scientists was held in Dakar, Senegal on April 24th and 25th 2012. The research recommendations developed during the course of this meeting are presented in this paper. The need for enhanced surveillance for meningitis in defined populations with good diagnostic facilities in African countries at risk of epidemics was identified as the highest priority. This is needed to determine the duration of protection against serogroup A meningococcal disease provided by PsA-TT and to determine the risk of disease and carriage caused by meningococci of other serogroups. Other research areas given high priority included identification and validation of serological correlates of protection against meningococcal disease and carriage, development of improved methods for detecting carriage and epidemiological studies aimed at determining the reasons underlying the peculiar epidemiology of meningococcal disease in the African meningitis belt. Minutes and working papers from the meeting are provided in supplementary tables and some of the presentations made at the meeting are available on the MenAfriCar consortium website (www.menafricar.org) and on the web site of the Centers for Disease Control (www.cdc.gov)., (Copyright © 2013. Published by Elsevier Ltd.. All rights reserved.)

Objectives: To determine the clinical relevance of exudative retinal detachment (ERD) and the rate of ERD resolution after plaque radiotherapy of posterior uveal melanomas., Methods: Retrospective, nonrandomized study of 135 consecutive patients with posterior uveal melanoma treated by iodine 125 plaque radiotherapy. Extent of ERD and tumor thickness were assessed before radiotherapy and at postoperative follow-up visits. Local tumor control was assessed at each follow-up visit., Results: An ERD was present in 71 patients (53%) and was a risk factor for local treatment failure (P =.03). The ERD resolved after radiotherapy in 59 (83%) of the 71 patients. The ERD resolved within 1 year in 64 patients (90%) (mean time to resolution, 5.6 months). The rate of ERD resolution correlated with the rate of decrease in tumor thickness (P =.004). The ERD did not resolve and the tumor thickness continued to increase in 5 patients, who required further intervention. A recurrent retinal detachment developed in 5 patients, who were diagnosed as having rhegmatogenous retinal detachment (3 patients) and lipid exudation secondary to tumor vasculopathy (2 patients). Two patients with local tumor recurrence did not develop a recurrent ERD. Local tumor control was achieved in 130 patients (96%)., Conclusions: An ERD may be a risk factor for local failure after plaque radiotherapy for uveal melanoma. If an ERD does not resolve within 9 to 12 months of radiotherapy and the tumor is not regressing, treatment failure should be suspected. A recurrent ERD does not necessarily represent local tumor recurrence.

The porin proteins of Neisseria meningitidis are important components of outer membrane protein (OMP) vaccines. The class 3 porin gene, porB, of a novel serogroup B, serotype 4, 15 isolate from Chile (Ch501) was found to be VR1-4, VR2-15, VR3-15 and VR4-15 by porB variable region (VR) typing. Rabbit immunization studies using outer membrane vesicles revealed immunodominance of individual PorB (class 3) VR epitopes. The predominant anti-Ch501 PorB response was directed to the VR1 epitope. Anti-PorB VR1 mediated killing was suggested by the bactericidal activity of Ch501 anti-sera against a type 4 strain not expressing PorA or class 5 OMPs. Studies that examine the molecular epidemiology of individual porB VRs, and the immune responses to PorB epitopes, may contribute to the development of broadly protective group B meningococcal vaccines.

The porin proteins PIA and PIB of Neisseria gonorrhoeae are serotyping antigens for the serovar classification system and leading candidates for gonococcal vaccine development. Although serotyping has been a useful tool, this method can be insensitive to critical sequence changes in the por gene, including those in surface-exposed variable regions (VRs). A sensitive and specific typing system for N. gonorrhoeae has been developed that uses biotin-labeled oligonucleotide probes with chemiluminescence detection to type PIB gene VRs. The PIB VR types of geographically and temporally diverse gonococcal strains and sexual contact isolates were determined. por VR typing discriminated between most unrelated isolates and provided information about individual VR type that was not apparent from serovar designations. PIB VR typing avoids limited monoclonal antibody availability, interlaboratory variation, and the requirement for culture-based surveillance associated with gonococcal serotyping, and provides useful information about the molecular epidemiology of individual por gene VRs.