Ahmed Kamel

Synthesis, spectroscopic and structural characterization, and antimicrobial studies of metal complexes of a new hexadentate Schiff base ligand. Spectrophotometric determination of Fe(III) in water samples using a recovery test

New Schiff base complexes were prepared using the bioactive antimicrobial bis-Schiff base ligand synthesized by condensation of 2-aminobenzoic acid and 2,2′-(ethylenedioxy)bis(benzaldehyde). The pKA value of the bis-Schiff base was determined through visible spectrophotometric experiments and the stability constants of its complexes were also studied. The structural features of the complexes were determined from their elemental analyses, magnetic susceptibility, molar conductance, and spectral (IR and 1H NMR) studies. Powder XRD indicates that all the complexes are amorphous except the Cr(III) and Cu(II) chelates which are crystalline. The data revealed that the stoichiometries of all prepared complexes are of 1:1 M/L type. The UV–vis absorption spectral data for the complexes suggest an octahedral geometry around the central metal ion. Thermogravimetric data (TG and DTG) were also studied. The kinetic and thermodynamic parameters for thermal decomposition of the complexes were calculated by graphical methods using the Coats–Redfern approach. The antimicrobial activity of the bis-Schiff base and its complexes was tested against a number of bacteria and fungi to assess their inhibiting potential. Most of the complexes exhibit antibacterial activity more than the parent bis-Schiff base. Also Cr(III), Co(II), and Ni(II) complexes have antifungal activity against Candida albicans whereas the parent bis-Schiff base is inactive. A recovery test was also applied for the spectrophotometric determination of Fe(III) in different natural water samples.Graphical abstract

Synthesis, spectroscopic, thermal and biological activity studies on triazine metal complexes.

The coordination behaviour of the triazine ligand with NNO donation sites, derived from 3-benzyl-7-hydrazinyl-4H-[1,3,4]thiadiazolo[2,3c][1,2,4]triazin-4-one (HL), towards some metal ions namely Mn(II), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) are reported. The metal complexes are characterized based on elemental analyses, IR, (1)H NMR, solid reflectance, magnetic moment, molar conductance and thermal analyses (TG, DTG and DTA). The ionization constants of the organic ligand under investigation as well as the stability constants of its metal chelates are calculated spectrophotometrically at 25°C. The chelates are found to have octahedral geometrical structures. The ligand (HL) and its binary chelates are subjected to thermal analyses (TG, DTG and DTA) and the different activation thermodynamic parameters are calculated from their corresponding DTG curves to throw more light on the nature of changes accompanying the thermal decomposition process of these compounds. The synthesized ligand and its metal complexes were found to have biological activity against the desert locust Schistocerca gregaria (Forsk.) (Orthoptera - Acrididae) and its adult longevities.

Fetal intracranial hemorrhage: sonographic criteria and merits of prenatal diagnosis

Abstract Purpose: To determine the sonographic criteria for diagnosis of fetal intracranial hemorrhage (ICH), using both gray scale ultrasound, and tomographic ultrasound imaging (TUI). Materials and methods: A prospective multicenter study, recruiting patients at risk of fetal ICH over four years. All cases with fetal ICH had serial ultrasound assessments, including TUI, fetal and postnatal MRIs. Results: Twenty-one patients were diagnosed with fetal ICH, two cases had extracerebral (subdural) hemorrhage, 16 cases had intracerebral (intraventricular) hemorrhage and three cases had combined hemorrhage. The mean gestational age at which they were diagnosed was 29.8 ± 5.2 weeks. Seventy-six percent of cases had no identifiable risk factors. IUGR was associated with 57.9% of cases. Using grey scale ultrasound, we demonstrated clear cut sonographic criteria for diagnosis of fetal ICH. TUI enabled us to detect some midline cerebral lesions not detected by grey scale 2D ultrasound alone. Fetal and postnatal MRI confirmed those findings. Conclusion: Ultrasonography can be used in the detection, classification and monitoring the progression of various types of ICH. TUI is an additional diagnostic tool that might help to detect the exact size, and extent of those lesions. Fetal MRI is not superior, but might aid in the diagnosis.

Design and implementation of a variable-structure adaptive fuzzy-logic yaw controller for large wind turbines

The current trend of wind energy generation industry is to use large and ultra-large wind turbines that can reach more than 10 MW in ratings; especially in off-shore wind farms. Therefore, more emphasis is being given by researchers to increase the harvested energy by each individual wind turbine. Previously, more focus has been given to pitch control techniques of turbine blades for improving the harvested energy and lowering the turbine maintenance cost. However, still not enough work is done to investigate the effectiveness of nacelle yaw control in improving the harvested energy specifically for large wind turbines. In this paper, we introduce a new yaw controller based on adaptive fuzzy systems. The control objective of the proposed controller is to effectively track of the wind direction by yaw motion of the turbine nacelle. For that reason, it is a fuzzy-logic-based controller that has the capability to adaptively tune its rule base online. The change in the fuzzy rule base is done using a variable structure direct adaptive control algorithm to achieve the pre-defined control objectives. This algorithm has two advantages. First, it has a good performance in the training phase as it makes use of the initial rule base defined for the fuzzy logic yaw controller. Second, it has a robust estimator since it depends on a variable structure technique. The adaptive nature of the proposed controller significantly reduces the rule base size and improves its performance. The previous statement is verified through three levels of testing. The first level is Model-In-the-Loop (MIL) MATLAB/SIMULINK extensive simulations, with the performance results get compared to that of a carefully tuned Proportional-Integral-Differential (PID) controller. The second level of testing is through Software-In-the-Loop (SIL) testing using the same use cases. The last level is the Processor-In-the-Loop (PIL) experimental tests using a Texas Instruments TMS320F28335 digital signal processing board.

Manual removal versus spontaneous delivery of the placenta at cesarean section in developing countries: a randomized controlled trial and review of literature

Abstract Purpose: Cesarean section (CS) rates have increased; this is especially concerning in developing countries. The mode of placental delivery contributes to morbidity associated with CS and determines blood loss during CS. We aimed to compare manual removal versus spontaneous delivery of the placenta at CS. Methods: In a randomized controlled trial, 574 women admitted for primary or repeat elective CS were randomized into two groups. In group A, the placenta was manually removed, whereas in group B, the placenta was left for spontaneous delivery. Blood loss, operative and postoperative data were recorded. Results: Blood loss was 875.2 ± 524.2 ml in group A versus 731.8 ± 426.7 ml in group B (p = .001), with a significant drop in postoperative HB (p = .015) and HCT (p = .031). In group A, odds ratios for blood loss (>1000 ml), HB drop (> 4g/dl), postpartum hemorrhage and blood transfusion were 2.581, 2.850, 2.614 and 1.665, respectively. However, the total operative time (p = .326), duration of hospital stay (p = .916) and intensive care unit (ICU) admission (p = .453) were not statistically different between the two groups. Conclusions: Manual removal of the placenta at CS is associated with a higher risk of blood loss, postpartum hemorrhage and blood transfusion, with no decrease in operative time.

Mucocele of the hard palate in children

OBJECTIVE Mucus retention cyst of the hard palate may result from obstruction of the ducts of the minor salivary glands, and it was defined as a mucocele. Although, the disease is not common in the hard palate, it was previously reported by many authors in the soft palate. The aim of our study was to present pediatric patients who were diagnosed to have mucocele of the hard palate, and to evaluate the outcome of the surgical excision of this lesion. METHODS This is a case series study included 8 pediatric patients who presented with cystic lesions on the hard palate which were removed surgically, and were diagnosed as mucoceles. Preoperative data, surgical procedures, and postoperative outcome were presented. Follow up of patients was performed for at least one year. RESULTS The swelling was detected as a single isolated lesion, on the side of the hard palate, covered with healthy mucosa, not tender, oval or round in shape, and measuring 0.4 to 1.7cm in its greatest dimension. Computed tomography showed a well defined cavity which was not invading the bone, and not disrupting the muscles of the palate. Histopathological examination confirmed that the lesion was a cavity that is lined with an epithelial layer with pseudoepitheliomatous hyperplasia. No patients developed intraoperative or postoperative complications, and no recurrence was detected in any patient. CONCLUSIONS Oral mucoceles can develop on the hard palate of the children, the lesions are mucus retention cysts. Complete surgical removal of the lesions with their cystic wall is a good treatment options, it carries no risk of recurrence.

Effect of hydrosalpinx on uterine and ovarian hemodynamics in women with tubal factor infertility

OBJECTIVE To evaluate the effect of hydrosalpinx on uterine and ovarian blood flows in women with tubal factor infertility. STUDY DESIGN In a cross-sectional study at a university teaching hospital, 60 women with hydrosalpinx-related tubal infertility (hydrosalpinx group) were compared with 60 women with male or unexplained infertility (non-hydrosalpinx group). In the mid-luteal (peri-implantation) phase of the cycle, endometrial thickness, uterine and ovarian artery pulsatility index (PI) and resistance index (RI), and endometrial and ovarian volume and 3D power Doppler vascularization index (VI), flow index (FI), and vascularization flow index (VFI) were measured in both groups. RESULTS The endometrial VI (p=0.002), FI (p=0.041), and VFI (p=0.018), and ovarian VI (p=0.011), and VFI (p=0.015) were significantly lower in the hydrosalpinx group than in the non-hydrosalpinx group. However, the endometrial thickness, uterine artery PI and RI, ovarian artery PI and RI, endometrial volume, and ovarian volume and FI were not significantly different between the two groups. CONCLUSION Hydrosalpinx is associated with impaired endometrial and ovarian blood flows which may adversely affect endometrial receptivity and oocyte quality.

Synthesis, Spectroscopic, and Thermal Characterization of Thiazole Metal Complexes: Biological Activity Studies

Metal complexes of the organic ligand with N azomethine and N thiazole donation sites, derived from 3-(2-(2-(2,6-dichlorobenzylidene)hydrazinyl)-4-oxo-4,5-dihydrothiazol-5-yl) acetic acid (H2L), with some transition metal ions, namely Mn(II), Fe(III), Co(II), Ni(II), Cu(II), and Zn(II), are reported. They are characterized based on elemental analyses, IR, 1H NMR, solid reflectance, magnetic moment, and molar conductance. The ionization constants are found to be 5.57 and 11.50, which can be attributed to loss of the hydrazo and the carboxylic acid protons, respectively. The stability constants of metal chelates, is calculated spectrophotometrically at 25°C, and the order of stability follows the Irving and Williams order. The chelates are found to have octahedral geometrical structures. The ligand (H2L) and its binary chelates are subjected to thermal analyses, and the different activation thermodynamic parameters are calculated using Coats-Redfern equation. The ligand and its metal complexes show a remarkable biological activity against the desert locust Schistocerca gregaria (Forsk) (Orthoptera – Acrididae) and its adult longevities.

Can AMH levels predict the need for increased medication during IVF/ICSI in PCOS women?

Abstract Purpose: To investigate the ability of anti-Mullerian hormone (AMH) to predict the step up of human menopausal gonadotropins (HMG) dose in women with polycystic ovarian syndrome (PCOS) undergoing IVF/ICSI cycles. Methods: AMH was drawn before ovulation induction in 976 PCOS women scheduled for IVF/ICSI. After all cycles ended, a receiver operating characteristic (ROC) curve analysis was done to investigate the ability of AMH to predict step up of the HMG. Results: The area under the curve (AUC) was 0.820 95%CI (0.792–0.848), and a cutoff value of 4.6 ng/ml (sensitivity 74%, specificity 82%) for AMH was taken (p < 0.01). Cases were divided into two groups retrospectively; group (A) (AMH ≤4.6 ng/ml), and group (B) (AMH >4.6 ng/ml). No difference in the mean age (p = 0.147); BMI (p = 0.411), basal FSH (p = 0.221), and starting dose (p = 0.195); however, the dose at which the first response occurred was higher in group (B) (p < 0.01). The total dose and number of days were higher in group (B) (both p < 0.01) irrespective of the PCOS subtype or androgen levels. Severe OHSS was also higher in group (B) (p = 0.026). Conclusions: PCOS with AMH >4.6 ng/ml are resistant to HMG stimulation, require dose step up during ART cycles, and are at higher risk for severe OHSS.

Effect of timing of pulmonary metastasis occurrence on the outcome of metastasectomy in osteosarcoma patients

BACKGROUND Complete metastasectomy is the best predictor of survival in patients with osteosarcoma pulmonary metastases. There has been some controversy in the literature regarding the prognostic significance of the timing of occurrence of lung metastasis. METHODS We reviewed the clinical course of all osteosarcoma patients with pulmonary metastases treated by metastasectomy in our hospital from January 2008 through December 2016. Each patient who underwent metastasectomy was placed into one of three groups based on whether lung metastases were present at initial presentation (Group 1), developed during chemotherapy (Group 2), or appeared after completion of chemotherapy (Group 3). Data were obtained retrospectively and follow-up was obtained until the end of June 2017. RESULTS We identified 170 patients with pulmonary nodules of whom 99 (58.2%) underwent at least one metastasectomy (149 thoracotomies). Eleven patients had benign pulmonary nodules and were excluded. The other 88 patients were classified as Group 1 (37), Group 2 (18) or Group 3 (33). The median follow-up was 35 months (range 8 to 99). Postmetastasis 5-year overall survival (OS) was 38.1 ± 6.4%; event-free survival (EFS) was 25 ± 5.3%. By group, postmetastasis 5-year OS and EFS were 34.3 ± 13% and 18 ± 9.3% in Group 1, 8 ± 6.5% and 6.5 ± 5% in Group 2, and 52 ± 11.4% and 25 ± 9% in Group 3 (P < 0.001). In univariate analysis, the only significant factors associated with survival were timing of occurrence of lung metastasis and the number of lung nodules found. CONCLUSION The timing of occurrence of lung metastasis is an important prognostic factor among osteosarcoma patients eligible for metastasectomy. Patients whose metastases occurred during chemotherapy had the worst survival. LEVEL OF EVIDENCE Level II.