Publications by authors named "Marwa Sharaf"

6 Publications

  • Page 1 of 1

A Novel Dual-Band (38/60 GHz) Patch Antenna for 5G Mobile Handsets.

Sensors (Basel) 2020 Apr 29;20(9). Epub 2020 Apr 29.

Electronics and Communications Department, College of Engineering and Technology, Arab Academy for Science, Technology & Maritime Transport, Alexandria 21937, Egypt.

A compact dual-frequency ( 38 / 60   GHz ) microstrip patch antenna with novel design is proposed for 5G mobile handsets to combine complicated radiation mechanisms for dual-band operation. The proposed antenna is composed of two electromagnetically coupled patches. The first patch is directly fed by a microstrip line and is mainly responsible for radiation in the lower band ( 38   GHz ). The second patch is fed through both capacitive and inductive coupling to the first patch and is mainly responsible for radiation in the upper frequency band ( 60   GHz ). Numerical and experimental results show good performance regarding return loss, bandwidth, radiation patterns, radiation efficiency, and gain. The impedance matching bandwidths achieved in the 38   GHz and 60   GHz bands are about 2   GHz and 3.2   GHz , respectively. The minimum value of the return loss is - 42 dB for the 38   GHz band and - 47 for the 60   GHz band. Radiation patterns are omnidirectional with a balloon-like shape for both bands, which makes the proposed single antenna an excellent candidate for a multiple-input multiple-output (MIMO) system constructed from a number of properly allocated elements for 5G mobile communications with excellent diversity schemes. Numerical comparisons show that the proposed antenna is superior to other published designs.
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http://dx.doi.org/10.3390/s20092541DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7249208PMC
April 2020

Prenatal ultrasound findings of holoprosencephaly spectrum: Unusual associations.

Prenat Diagn 2020 04 10;40(5):565-576. Epub 2020 Feb 10.

Clinical Genetics Department, Human Genetics and Genome Research Division, National Research Centre, Cairo, Egypt.

Objective: The objective of this study is to evaluate the prenatal diagnosis, postnatal characteristics, and the spectrum of associated findings in fetuses with holoprosencephaly (HPE).

Methods: Fetal neurosonograms, postnatal assessment, and chromosomal analysis were performed in a cohort of 25 fetuses with HPE.

Results: The prevalence of HPE in high-risk pregnancies was 4.4:10 000. The alobar subtype was the most frequently encountered, with 17 cases (68%). Interestingly, among them, four cases (16%) presented with the rare agnathia-otocephaly complex. Chromosomal abnormalities were detected in 11 cases (44%), the most frequent being trisomy 13 in seven cases (five alobar, one semilobar, and one lobar HPE), followed by trisomy 18 in two cases with semilobar HPE. One case of alobar HPE had 45, XX, t(18;22) (q10;q10), -18p karyotyping, and one case of semilobar HPE was associated with triploidy. Facial malformations in HPE spectrum ranged from cyclopia, proboscis, and arrhinia that were associated with the alobar subtype to hypotelorism and median cleft that were frequent among the semilobar and lobar subtypes. Associated neural tube defects were identified in 12% of cases.

Conclusion: Our study illustrates the clinical and genetic heterogeneity of HPE and describes different chromosomal abnormalities associated with HPE.
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http://dx.doi.org/10.1002/pd.5649DOI Listing
April 2020

Perioperative nonhormonal pharmacological interventions for bleeding reduction during open and minimally invasive myomectomy: a systematic review and network meta-analysis.

Fertil Steril 2020 01 18;113(1):224-233.e6. Epub 2019 Nov 18.

Department of Obstetrics and Gynecology, Faculty of Medicine, Cairo University, Cairo, Egypt.

Objective: To synthesize evidence on the most effective pharmacological interventions for bleeding reduction during open and minimally invasive myomectomy.

Design: Systematic review and network meta-analysis of randomized controlled trials (RCTs).

Setting: Not applicable.

Patients: Trials assessing efficacy of pharmacological interventions during different types of myomectomy.

Interventions: Misoprostol, oxytocin, vasopressin, tranexamic acid (TXA), epinephrine, or ascorbic acid.

Main Outcome Measures: Intraoperative blood loss and need for blood transfusion.

Results: The present review included 26 randomized control trials (RCTs) (N = 1627). For minimally invasive procedures (9 RCTs; 474 patients), network meta-analysis showed that oxytocin (mean difference [MD] -175.5 mL, 95% confidence interval [CI] -30.1.07, -49.93), ornipressin (MD -149.6 mL, 95% CI - 178.22, -120.98), misoprostol, bupivacaine plus epinephrine, and vasopressin were effective in reducing myomectomy blood loss, but the evidence is of low quality. Ranking score of treatments included in subgroup analysis of minimally invasive myomectomy showed that oxytocin ranked first in reducing blood loss, followed by ornipressin. For open myomectomy (17 RCTs; 1,153 patients), network meta-analysis showed that vasopressin plus misoprostol (MD -652.97 mL, 95% CI - 1113.69, -174.26), oxytocin, TXA, and misoprostol were effective; however, the evidence is of low quality. Vasopressin plus misoprostol ranked first in reducing blood loss during open myomectomy (P = .97).

Conclusion: There is low-quality evidence to support uterotonics, especially oxytocin, and peripheral vasoconstrictors as effective options in reducing blood loss and need for blood transfusion during minimally invasive myomectomy. Oxytocin is the most effective intervention in minimally invasive myomectomy. For open myomectomy, a combination of uterotonics and peripheral vasoconstrictors is needed to effectively reduce blood loss.
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http://dx.doi.org/10.1016/j.fertnstert.2019.09.016DOI Listing
January 2020

Reliability of transperineal ultrasound for the assessment of the angle of progression in labor using parasagittal approach versus midsagittal approach.

J Matern Fetal Neonatal Med 2019 Oct 23:1-6. Epub 2019 Oct 23.

Department of Obstetrics and Gynecology, Sant'Orsola Malpighi University Hospital, University of Bologna , Bologna , Italy.

To assess the inter-method agreement between midsagittal (msAoP) and parasagittal (psAoP) measurements of the angle of progression (AoP) during labor. In addition, we aimed to evaluate the correlation between AoP measurements by both midsagittal and parasagittal approaches with the mode of delivery. We recruited a nonconsecutive series of women in active labor with a singleton uncomplicated term pregnancy with fetuses in vertex presentation. Women underwent transperineal ultrasound in the absence of uterine contractions or maternal pushing to measure both msAoP and psAoP. The inter-method agreement between the two acquisitions was then assessed. Lastly, both measurements were compared between women who had a vaginal delivery versus those who underwent cesarean section (CS). Overall, 151 women were included in the study. We found an excellent agreement between msAoP and psAoP (ICC 0.935; 95% CI 0.912-0.953,  < .001). On the other hand, psAoP overestimated the measurements in comparison with msAoP (101.2 ± 15.6 versus 98.2 ± 16.0,  < .001). There was a significant correlation between both methods of AoP assessment and duration of the active second stage of labor and AoP measured by either method was significantly wider in patients who delivered vaginally compared to those who had a CS. Our data showed a significant difference in the measured angle between the psAoP and the originally described msAoP. The automated measurements of AoP that have been introduced are designed using the parasagittal visualization of the more echogenic pubic arch, rather than the hypoechogenic pubic symphysis. We think that in the light of our data, care should be taken before applying data from midsagittal measurement in centers using the parasagittal automated approach.
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http://dx.doi.org/10.1080/14767058.2019.1678143DOI Listing
October 2019

Physical endometrial manipulation and its impact on success rate and live birth rate in ICSI in patients with unexplained infertility after recurrent ICSI failure, a double blinded randomized controlled trial.

J Matern Fetal Neonatal Med 2020 Sep 22;33(17):2983-2989. Epub 2019 Jan 22.

Obstetrics and Gynecology Department, AlAzhar University, Cairo, Egypt.

Unexplained infertility is a rising problem and endometrial manipulation could be one of the solutions for enhancing the pregnancy rate and live birth rate in such circumstances. To evaluate the influence of local endometrial physical manipulation with specializd method for endometrial and tubal hydration (Elgazzar and Alalfy technique) on ICSI outcome and in increasing chemical, clinical, and live birth rate in ICSI after previous recurrent ICSI failure in patients with unexplained infertility. When comparing group 1 (hydrotubation group) and group 2 (the control group with no intervention) with regards to the biochemical, clinical, and live birth rate, the hydrotubation group revealed higher rates and a better ICSI outcome. Hydrotubation is useful in increasing biochemical, clinical, and live birth rates after recurrent failed ICSI trials with a specialized method for hydration of endometrium and tubes (Elgazzar and Alalfy technique).
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http://dx.doi.org/10.1080/14767058.2019.1566897DOI Listing
September 2020

Multicenter randomized controlled trial assessing the impact of a cervical traction maneuver (Amr's maneuver) on the incidence of postpartum hemorrhage.

Int J Gynaecol Obstet 2019 Jan 22;144(1):56-61. Epub 2018 Oct 22.

ClinAmygate, Cairo, Egypt.

Objective: To assess the impact of a cervical traction maneuver (Amr's maneuver) used in conjunction with active management of the third stage of labor (AMTSL) on the incidence of postpartum hemorrhage (PPH).

Method: The present multicenter randomized controlled trial was conducted in Cairo between March 1, 2016, and June 30, 2017. Women aged at least 18 years who had singleton pregnancies and were candidates for vaginal delivery were enrolled. After block randomization, AMTSL was performed for all participants. Following placental delivery, Amr's maneuver using cervical traction for 90 seconds was carried out in the study group. The primary outcome, incidence of PPH (>500 mL blood loss) within 6 hours of delivery, was compared between the study and control groups in an intention-to-treat analysis.

Results: There were 852 patients randomized to the study (n=426) and control (n=426) groups. The incidence of PPH was significantly lower in the study group compared with the control group (6 [1.4%] vs 19 [4.5%]; P=0.015). Absolute risk reduction of 3.1% (95% CI 0.8-5.6), relative risk reduction of 0.32 (95% CI 0.13-0.78), and number needed to treat of 33 (95% CI 129-18) were observed in the study group.

Conclusion: Amr's maneuver was effective in decreasing the incidence of PPH. ClinicalTrials.gov Identifier: NCT02660567.
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http://dx.doi.org/10.1002/ijgo.12687DOI Listing
January 2019
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