Exploiting diluted bioethanol solutions for the production of ethylene: Preliminary process design and heat integration

Several activity tests on a zeolite-based catalyst for the ethanol to ethylene dehydration reaction are used to outline the stoichiometry of 4 reactions describing the observed outcome. The heat and mass balances of a reactor were calculated. The thermal input was mainly sustained with a standard product-to-feed heat exchange. Upstream, two possible strategies of ethanol-water beer concentration were compared, namely a single stage flash and a small column, yielding respectively a 3:1 water:ethanol mixture and a slightly diluted azeotrope. The external heat input needed for the separation unit, the feed heating up to the reaction temperature and the reaction upkeep are compared. A flow diagram for the hot utility is then designed, converting part of the water of the beer into superheated steam that gives also electric power. The conceptual design of an ethanol to ethylene plant is therefore available to exploit bioethanol solution with different water/ethanol ratios, with different ethanol purification routes with variable heat input and energy recovery

Improved Characterization of Polyunsaturated Fatty Acids Desaturases and Elongases by Co-Expression in Saccharomyces cerevisiae with a Protozoan Acyl-CoA Synthetase

Saccharomyces cerevisiae is a valuable host for the expression and characterization of eukaryotic enzymes involved in polyunsaturated fatty acid (PUFA) biosynthesis, such as elongases and desaturases. The yeast allows a correct subcellular localization of these proteins, provides electron donors required by desaturases and is unable to synthesize PUFA that could interfere in the enzymes characterization. Unfortunately, S. cerevisiae incorporates very long chain PUFAs inefficiently, which could interfere in the characterization of enzymes using these substrates. Acyl-CoA synthetases (ACS) are involved in fatty acids uptake, and catalyze the synthesis of the corresponding CoA thioesters. ACS provides the substrates for elongases, acyl-CoA desaturases and acyl transferases. Transferases are required to synthesize phospholipids which in turn, are substrates for acyl-lipid desaturases. Expression in yeast of Trypanosoma brucei ACS1 notably improves the uptake of a wide variety of PUFA. Co-expression of ACS1 with Elo5 elongase from Leishmania major or Des4 desaturase from T. brucei showes, respectively, 2- and 5.6-fold increases in the uptake of the PUFA substrates and 2.4- and 3.5-fold increases in substrate conversion. It also allows to produce significant amount of Des4 desaturase product for further analysis, whereas it is obtained in trace amounts when the enzyme is expressed alone. Practical applications: In this report, the use of yeast strains expressing ACS1 is proposed as a useful tool in the characterization of polyunsaturated fatty acids desaturases and elongases. Furthermore, this model could be used for the production of nutraceutical PUFA. S. cerevisiae (Sc) expressing an Acyl-CoA synthetase from T. brucei (ACS1) significantly increases the intake of polyunsaturated fatty acids (PUFA), which are unusual for the yeast. It improves the possibility to study enzymes from the PUFA synthetic pathway, such as desaturases and elongases, by co-expression in a Sc-ACS1 background.Fil: Tripodi, Karina Eva Josefina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: Berardi, Florencia. Universidad Nacional de Rosario; ArgentinaFil: Uttaro, Antonio Domingo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; Argentin

Influence of bacterial colonization of the healing screws on peri-implant tissue

Abstract Background/purpose A bacterial adhesion to implant surfaces is a first stage of peri-implant mucositis and peri-implantitis. The aim of this longitudinal study was to examine the quantitative and qualitative biofilm formation on healing screws and the presence of periodontal pathogens in peri-implant crevicular fluid (PCF). In each of the 30 participants, one healing screw was adapted to every single implant. Materials and methods Thirty patients, 18 females and 12 males, were selected. Thirty healing abutments were left in situ for 20, 30 and 90 days. At regular times, the presence/absence of bleeding on probing (BOP) was determined. The specific periodontal pathogens were determined in PCF, by polymerase chain reaction (PCR). After 20, 30 and 90 days, the healing screws were removed and analyzed to establish the total bacterial count by a culture method. Results BOP+ increased significantly after 90 days. Biofilm was detected on all healing abutments and the number of cultivable oral flora showed a significant increase from 20 days to 30 days and to 90 days. At 90 days, the anaerobic counts constituted the bulk of plaque examined and Veillonella spp. were present in higher percentages levels (19.82%) among the Gram-negative bacteria. No significant differences among the experimental groups were detected in the frequencies of detection of each monitored bacteria in PCF. Conclusion The healing screws left in situ for a period of 90 days caused a peri-implant inflammation and the presence of periodontal pathogenic bacteria in the peri-implant sulcus, due to the plaque accumulation on screw surfaces

Process simulation for the design and scale up of heterogeneous catalytic process: Kinetic modelling issues

Process simulation represents an important tool for plant design and optimization, either applied to well established or to newly developed processes. Suitable thermodynamic packages should be selected in order to properly describe the behavior of reactors and unit operations and to precisely define phase equilibria. Moreover, a detailed and representative kinetic scheme should be available to predict correctly the dependence of the process on its main variables. This review points out some models and methods for kinetic analysis specifically applied to the simulation of catalytic processes, as a basis for process design and optimization. Attention is paid also to microkinetic modelling and to the methods based on first principles, to elucidate mechanisms and independently calculate thermodynamic and kinetic parameters. Different case studies support the discussion. At first, we have selected two basic examples from the industrial chemistry practice, e.g., ammonia and methanol synthesis, which may be described through a relatively simple reaction pathway and the relative available kinetic scheme. Then, a more complex reaction network is deeply discussed to define the conversion of bioethanol into syngas/hydrogen or into building blocks, such as ethylene. In this case, lumped kinetic schemes completely fail the description of process behavior. Thus, in this case, more detailed\ue2\u80\u94e.g., microkinetic\ue2\u80\u94schemes should be available to implement into the simulator. However, the correct definition of all the kinetic data when complex microkinetic mechanisms are used, often leads to unreliable, highly correlated parameters. In such cases, greater effort to independently estimate some relevant kinetic/thermodynamic data through Density Functional Theory (DFT)/ab initio methods may be helpful to improve process description

Presurgical treatment of uterine myomas with the GnRH-antagonist relugolix in combination therapy: an observational study

To evaluate if a preoperative medical treatment with the GnRH-antagonist relugolix in combination therapy in a series of patients with abnormal uterine bleeding associated with uterine myomas may correct the anemia before scheduled surgery for myoma-associated AUB. Thirty-one patients scheduled for surgery underwent a pre-operative three-month course with a daily oral tablet of 40 mg relugolix, 1 mg estradiol, and 0.5 mg norethindrone acetate. Hemoglobin levels, uterine volumes, largest myoma diameter, and VAS score for dysmenorrhea, pelvic pressure and bleeding discomfort, and indication to surgery were evaluated at study enrollment and at the end of therapy. Mean hemoglobin levels increased by 25%, from 9.3 ± 1.1 to 11.6 ± 1.7 g/dL after three months (p < 0.001). Uterine volume decreased from 380.7 ± 273.4 mL to 281.7 ± 198.7 mL (p < 0.001), whereas the diameter of the largest myoma decreased from 6.4 ± 2.8 cm to 5.5 ± 2.2 cm (p < 0.001). Four patients (13%), initially planned for a laparotomy procedure, were converted to a minimally-access procedure, whereas in eight patients (26%) surgery was avoided after medical therapy. Dysmenorrhea score improved from 4.7 ± 3.2 to 0.6 ± 1.1 (p < 0.0001). Pelvic pressure score decreased from 5.9 ± 2.1 to 3.1 ± 2.3 (p < 0.0001), whereas bleeding discomfort decreased from 7.4 ± 3.0 to 0.4 ± 1.6 (p < 0.0001). Preoperative GnRH-antagonist therapy may enhance hemoglobin levels, decrease uterine and myoma size, and alleviate symptoms, potentially enabling safe surgical procedures

A Retrospective Case Series in Fournier’s Disease. And Its Emergency Management et Grafting Technique for Penis Coverage

Fournier’s gangrene is a necrotizing soft tissue infection of the genital, perineal, and perirectal areas. A primary isolated involvement of the penis is rare, but it can be elected in some circumstances. •epurpose ofthiscase series isto present the …ndings of our thirteen years’ experience in the reconstruction of the penis in Fournier’s gangrene and our full-thickness grafting technique to cover the penis rod. We retrospectively reviewed patient data who underwent a penis reconstruction following Fournier’s gangrene in 2018. •e data was analyzed to report the estimated percentage of complications, of patients with primary or secondary gangrene of the penis, the number of reinterventions, and …nally the percentage of deaths or recovery. 23 patients underwent reconstruction with our technique of full-thickness skin graft. In all cases, the skin graft was harvested from the upper armwith anarrow shapemark. Nofurther penile revision surgery was required, and neither patient complained about retraction, nor traction, or pain during erection. •e donor site healed without any complications. We believe that the coverage of the penis using our grafting technique is safe, easily reproducible, and demonstrates excellent esthetic and functional results

Evaluation of Clinicopathological and Molecular Parameters on Disease Recurrence of Papillary Thyroid Cancer Patient: A Retrospective Observational Study

The American Joint Committee on Cancer has revised the Tumor-Node-Metastasis (TNM) staging system for papillary thyroid cancer (PTC) patients. We examined the impact of this new classification (TNM-8) on patient stratification and estimated the prognostic value of clinicopathological features for the disease-free interval (DFI) in a cohort of 1148 PTC patients. Kaplan-Meier analyses showed that all clinicopathological parameters analyzed, except age and multifocality, were associated significantly with DFI. Cox regression identified tall cell PTC variant and stage as independent risk factors for DFI. When the stage was replaced with age, tumor size, and lymph node (LN) metastases in the set of covariates, the lateral LN metastases stood out as the strongest independent predictor of DFI, followed by tall cell variant and age. A noteworthy result emerging from these analyzes is that regression models had lower Akaike and Bayesian information criterions if variables were categorized based on the TNM-7. In addition, we examined data from a different PTC patient cohort, acquired from The Cancer Genome Atlas database, to verify whether the DFI prediction could be enhanced by further clinicopathological and molecular parameters. However, none of these was found to be a significant predictor of DFI in the Cox model

Fertility specialists’ views, behavior, and attitudes towards the use of endometrial scratching in Italy

Background: Endometrial scratching (ES) or injury is intentional damage to the endometrium performed to improve reproductive outcomes for infertile women desiring pregnancy. Moreover, recent systematic reviews with meta-analyses and randomized controlled trials demonstrated that ES is not effective, data on the safety are limited, and it should not be recommended in clinical practice. The aim of the current study was to assess the view and behavior towards ES among fertility specialists throughout infertility centers in Italy, and the relationship between these views and the attitudes towards the use of ES as an add-on in their commercial setting. Methods: Online survey among infertility centers, affiliated to Italian Society of Human Reproduction (SIRU), was performed using a detailed questionnaire including 45 questions with the possibility to give "closed" multi-choice answers for 41 items and "open" answers for 4 items. Online data from the websites of the infertility centers resulting in affiliation with the specialists were also recorded and analyzed. The quality of information about ES given on infertility centers websites was assessed using a scoring matrix including 10 specific questions (scored from 0 to 2 points), and the possible scores ranged from 0 to 13 points ('excellent' if the score was 9 points or more, 'moderate' if the score was between 5 and 8, and 'poor' if it was 4 points or less). Results: The response rate was of 60.6% (43 questionnaires / 71 infertility SIRU-affiliated centers). All included questionnaires were completed in their entirety. Most physicians (~ 70%) reported to offer ES to less than 10% of their patients. The procedure is mainly performed in the secretory phase (69.2%) using pipelle (61.5%), and usually in medical ambulatory (56.4%) before IVF cycles to improve implantation (71.8%) without drugs administration (e.g., pain drugs, antibiotics, anti-hemorrhagics, or others) before (76.8%) or after (64.1%) the procedure. Only a little proportion of infertility centers included in the analysis proposes formally the ES as an add-on procedure (9.3%), even if, when proposed, the full description of the indications, efficacy, safety, and costs is never addressed. However, the overall information quality of the websites was generally "poor" ranging from 3 to 8 and having a low total score (4.7 ± 1.6; mean ± standard deviation). Conclusions: In Italy, ES is a procedure still performed among fertility specialists for improving the implantation rate in IVF patients. Moreover, they have a poor attitude in proposing ES as an add-on in the commercial setting

Genetic and Chemical Evaluation of Trypanosoma brucei Oleate Desaturase as a Candidate Drug Target

Background: Trypanosomes can synthesize polyunsaturated fatty acids. Previously, we have shown that they possess stearoyl-CoA desaturase (SCD) and oleate desaturase (OD) to convert stearate (C18) into oleate (C18:1) and linoleate (C18:2), respectively. Here we examine if OD is essential to these parasites. Methodology: Cultured procyclic (insect-stage) form (PCF) and bloodstream-form (BSF) Trypanosoma brucei cells were treated with 12- and 13-thiastearic acid (12-TS and 13-TS), inhibitors of OD, and the expression of the enzyme was knocked down by RNA interference. The phenotype of these cells was studied. Principal Findings: Growth of PCF T. brucei was totally inhibited by 100 mM of 12-TS and 13-TS, with EC50 values of 4062 and 3062 mM, respectively. The BSF was more sensitive, with EC50 values of 763 and 261 mM, respectively. This growth phenotype was due to the inhibitory effect of thiastearates on OD and, to a lesser extent, on SCD. The enzyme inhibition caused a drop in total unsaturated fatty-acid level of the cells, with a slight increase in oleate but a drastic decrease in linoleate level, most probably affecting membrane fluidity. After knocking down OD expression in PCF, the linoleate content was notably reduced, whereas that of oleate drastically increased, maintaining the total unsaturated fatty-acid level unchanged. Interestingly, the growth phenotype of the RNAi-induced cells was similar to that found for thiastearate-treated trypanosomes, with the former cells growing twofold slower than the latter ones, indicating that the linoleate content itsel