Chemical characteristics of the brines and sediments of the Ayun Musa and El-Shatt sabkha sites indicate an increase in the salinity gradient of the groundwater, passing upwards through the sabkha sediments. The potassium content of the pore water through the vertical profile of the sabkha at Ayun Musa, calculated versus ionic content of two gypsum crusts within the sediment and from the overlying surficial halite demonstrates that there is a clearly defined rise in pore-water concentration through the sabkha profile, from the ground-water table up to the surface. Evaporative pumping is probably the active process responsible for the upward capillary movement through the studied sediments.The calcium sulfate present in the sediment of both sabkhas is in the form of gypsum and is believed to be the primary sulfate product. It is present as crusts of gypsum rosettes and as fine disseminated lenticular crystals within a elastic matrix. The depositional profile at both sabkha sites is usually topped by halite, but the halite at Ayun Musa is a surficial crust (from capillary growth) while the deposition at EI-Shatt is both in the form of subaqueously-grown layers as well as surficial crusts. The profile at El-Shatt suggests that the thick halite deposits in the low areas of the sabkha form by the solutional reworking of marginal salt as well as directly from brine concentration after flooding. Because the sediments of both sabkhas shows any significant diagenetic alteration, these two sites appear to have been affected only by the very earliest stages of diagenesis.The Ayun Musa sabkha is a typical continental type receiving waters from rainfall that dissolve salts from the surrounding Miocene sediments and concentrates them within the capillary zone of the soil profile by evaporative pumping, while the EI-Shatt sabkha is largely marine, and receives its water through direct input of seawater from the Gulf of Suez by both flooding and by seepage recharge.

BACKGROUND: Multiple materials have been used for cranioplasty with different pros and cons. The current literature is defective in studies comparing titanium mesh, polyetheretherketone (PEEK), and polymethyl methacrylate (PMMA).OBJECT: This prospective randomized study was conducted to compare the outcomes of three cranioplasty techniques; titanium mesh, PEEK, and PMMA, regarding the failure rates, the complications, and the patients' satisfaction. METHODS:A total of 84 cases were included, and they were randomly divided into three groups (28 cases in each group); titanium mesh, PEEK, and PMMA groups. All patients underwent proper preoperative evaluation, including history taking, neurological examination, and routine investigations. The operative time and postoperative complications were recorded. Our primary outcome was implant failure rates, whereas secondary outcomes included implant exposure, surgical site infection, graft resorption, postoperative new-onset seizures, extradural hemorrhage, and patient satisfaction.RESULTS: Age, gender, indication for cranioplasty, and operative time did not show any significant differences between the three groups. The prevalence of implant failure was 10.7%, 3.6%, and 14.3% in the titanium mesh, PEEK and PMMA groups, respectively. Although all complications (apart from extradural hemorrhage) tended to have a higher prevalence in the PMMA group, no significant difference was detected between the three groups regarding these complications. However, this lead to a significant decrease in patients' satisfaction in the PMMA group. CONCLUSION: Titanium mesh, PEEK, and PMMA have a comparable complication profile when used for cranioplasty. However, complication rates showed a slight increase with PMMA, which lead to decreased patient satisfaction.

BACKGROUND: Multiple approaches exist to manage anterior and middle cranial fossae lesions such as frontal, frontotemporal, pterional, orbitozygomatic, and supraorbital approaches. OBJECTIVE:The current study was conducted to compare the classic pterional approach and the supraorbital eyebrow approache in the surgical treatment of anterior and middle cranial fossae lesions. PATIENTS AND METHODS:This retrospective study included 40 patients divided into two groups; the pterional group included 21 cases, while the supraorbital one included 19 cases. The collected data included; preoperative data (age, gender, American Society of Anaesthesiologists (ASA) status, tumor size, and extension), operative data (operative time, operative complications, and blood loss), and postoperative data (hospital stay, pathology, complications, cosmoses, and mortality). RESULTS:The two approaches did not express significant differences regarding all of the preoperative variables. However, operative time and blood loss were significantly increased in the pterional approach. Gross total resection was achieved in 85.71% and 84.21% of patients in pterional and suprafrontal approaches, respectively. The incidence of brain edema, cerebrospinal fluid (CSF) leakage, and surgical site infection did not significantly differ between the two approaches. However, the supraorbital group was significantly associated with increased eyebrow edema, increased supraorbital sensational loss, and more cosmetic satisfaction. CONCLUSION:Supraorbital eyebrow approach has proven to be efficacious and safe in dealing with anterior and middle cranial fossae lesions.