Transesterification Of Glycerol With Dimethyl Carbonate To Glycerol Carbonate Over Ash-, Clay- Based And Strontium-Aluminum Mixed Oxide Catalysts

The global growth in biodiesel production over the past decade has led to the availability of significant quantities of glycerol as a by-product of the triglyceride transesterification process. Glycerol (GL) is a versatile feedstock for producing chemicals such as glycerol carbonate (GC) which can be produced by the transesterification of glycerol with dimethyl carbonate (DMC) over base catalyst. In this work, dolomite, sodium rich clay, oil palm ash and K-zeolite synthesized form fly ash have been utilized as low-cost heterogeneous basic catalysts for GC synthesis from GL and DMC. The study was conducted in a batch reactor at different reaction conditions (1-7 wt%) catalyst loading; (1:1-4:1) DMC:GL molar ratio; (55-75 OC) reaction temperature and (0.5-2 h) reaction time. At the best operating conditions of 5 wt% catalyst loading; 3:1 DMC: GL molar ratio; 75 OC reaction temperature and 1.5 h reaction time, the yields of GC obtained were 98.4%, 97.3%, 96.4% and 94% for Na-clay, oil palm ash, K-zeolite and dolomite, respectively. In terms of catalyst reusability and leaching, all catalysts suffered from leaching of metallic species in range between (4.23-31%) and the best catalytic performance was obtained by Na-clay where the minimum leaching was occurred (4.23%) compared to other low-cost catalysts and it was used successfully for four cycle runs. Strontium-aluminum mixed oxide catalyst was also developed in order to have more stable and unleachable heterogeneous catalyst for GC synthesis from GL and DMC

Role of L- glutamine and crizanlizumab in sickle cell anaemia painful crisis reduction

BackgroundPatients with sickle cell disease, frequently ‎ suffer from intense painful episodes. Till recently hydroxyurea was the only available medical therapy that approved for reduction of painful episodes.AimsTo summarize the available data from randomized controlled trials that aim to evaluate the efficacy of newly approved L-‎glutamine‎ (alters redox state of red blood cells ‎‎[RBCs]) ‎and ‎crizanlizumab (‎(anti-P-selectin)‎)‎ ‎on vaso-occlusive episodes in Sickle cell disease ‎ patients.Methods PubMed, ‎Google Scholar, and EBSCO ‎ databases were ‎‎systematically search for relevant articles. The terms ‎ ‎ ‎ L-glutamine, sickle cell disease, sickle cell ‎anaemia,‎ ‎‎crizanlizumab ‎and vaso-occlusive episodes‎ were used.Results Out of Four-hundred seventy-two records, only three fulfilled the inclusion criteria. Two trials were aimed to evaluate the efficacy of L-glutamine therapy on the frequency of painful crises in sickle cell anaemia patients. Both studies showed that L-glutamine therapy significantly reduce the frequency of VOEs. Only one trial examined the ability of crizanlizumab on VOEs reduction, and showed crizanlizumab successful reduce the occurrence of VOEs.‎ConclusionNewer agent ‎with different mechanism of action, such as ‎L-glutamine, ‎and crizanlizumab may consider if ‎hydroxyurea not effective or not ‎tolerable

Safety and Feasibility Report of Robotic-assisted Left Lateral Sectionectomy for Pediatric Living Donor Liver Transplantation: A Comparative Analysis of Learning Curves and Mastery Achieved with the Laparoscopic Approach

Background. There is a growing interest in left lateral sectionectomy for donor hepatectomy. No data are available concerning the safety of the robotic (ROB) approach. Methods. A retrospective comparative study was conducted on 75 consecutive minimally invasive donor hepatectomies. The first 25 ROB procedures performed from November 2018 to July 2019 were compared with our first (LAP1) and last 25 (LAP2) laparoscopic cases performed between May 2013 and October 2018. Short-term donors and recipients' outcomes were analyzed. Results. No conversions were noticed in ROB whereas 2 conversions (8%) were recorded in LAP1 and none in LAP2. Blood loss was significantly less in ROB compared with LAP1 (P ≤ 0.001) but not in LAP2. Warm ischemia time was longer in ROB (P ≤ 0.001) with respect to the other groups. Operative time was similar in the 3 groups (P = 0.080); however, the hospital stay was shorter in ROB (P = 0.048). The trend in operative time in ROB was significantly shorter compared to LAP1 and LAP2: linear R20.478, P≤0.001; R20.012, P = 0.596; R30.004, P = 0.772, respectively. Donor morbidity was nihil in ROB, similar in LAP1 and LAP2 (n=3%-12%; P = 0.196). ROB procedures required less postoperative analgesia (P = 0.002). Recipient complications were similar for all groups (P = 0.274), and no early retransplantations were recorded. Conclusions. Robotic left lateral sectionectomy for donor hepatectomy is a safe procedure with results comparable to the laparoscopy in terms of donor morbidity and overall recipients' outcome when the procedure is performed by experts. Certainly, its use is currently very limited

Large for size in pediatrics liver transplant using left lateral segment grafts: A single center experience

Background: There are still controversies in using the large left lateral segment in pediatrics LT, with the possibility of the problem of LFS grafts, and the use of monosegmental or reduced liver grafts in small infants. This study aimed to evaluate our experience with LFSG in pediatrics LT. Methods: A cohort retrospective analysis was conducted including pediatric recipients who underwent LT between January 2011 and October 2019. We compared recipients with GRWR ≥ 4% (LFS) vs GRWR < 4% as an average for size grafts. Results: There were 331 pediatric LT, 74 patients with GRWR ≥ 4%, and 257 patients with GRWR < 4%. In the group of LFS grafts, temporary abdominal closure by silicon patch was done in 39 patients (52.7%), 2 patients (2.7%) had postoperative HAT, 3 patients (4.1%) early PVT, 1 patient (1.3%) bile leak, and 3 patients (4.1%) had wound infection, with no significant difference in these complications between the 2 groups. In patients with LFS- grafts, the 1-, 3-, 5-, and 7-year patients survival rates were 94.6%, 91.7%, 91.7%, and 91.7%, respectively, while the survival rates in patients of the other group were 96.1%, 92.6%, 91.9%, and 91.9%, respectively, with no significant difference (p =.85). Conclusion: Using LFS graft by left lateral segment in pediatric LT with potential delayed abdominal closure is a safe and feasible option with good outcomes and unnecessary need for graft reduction if performed by an experienced multidisciplinary team