An Overview of the Non-Energetic Valorization Possibilities of Plastic Waste via Thermochemical Processes

The recovery and recycling/upcycling of plastics and polymer-based materials is needed in order to reduce plastic waste accumulated over decades. Mechanical recycling processes have made a great contribution to the circularity of plastic materials, contributing to 99% of recycled thermoplastics. Challenges facing this family of processes limit its outreach to 30% of plastic waste. Complementary pathways are needed to increase recycling rates. Chemical processes have the advantage of decomposing plastics into a variety of hydrocarbons that can cover a wide range of applications, such as monomers, lubricants, phase change materials, solvents, BTX (benzene, toluene, xylene), etc. The aim of the present work is to shed light on different chemical recycling pathways, with a special focus on thermochemicals. The study will cover the effects of feedstock, operating conditions, and processes used on the final products. Then, it will attempt to correlate these final products to some petrochemical feedstock being used today on a large scale.

Acute Kidney Injury Among COVID-19-Positive Patients Is Associated With Higher Mortality: A Single-Center Experience

OBJECTIVES

Renal complications of COVID-19 are not yet well studied. We aimed to evaluate acute kidney injury prevalence among hospitalized patients with COVID-19 infection and explore its effect on patient outcomes.

MATERIALS AND METHODS

We retrospectively evaluated 586 hospitalized patients with COVID-19. Of these patients, 267 (45.5%) developed acute kidney injury, as classified according to the Kidney Disease Improving Global Outcomes guidelines. We compared this group with 319 patients (54.5%) without acute kidney injury.

RESULTS

Most patients in both study groups were men; mean age was 60.8 ± 14 versus 51.7 ± 16 years. Comorbid conditions that were substantially predominant among patients with acute kidney injury were diabetes mellitus (64% vs 42.9%), hypertension (72.6% vs 43.5%), and ischemic heart disease (25% vs 14.7%). Fever, cough, shortness of breath, and dehydration were the main presentations among patients with acute kidney injury, and patients in this group had greater prevalence of radiological findings concordant with COVID-19 (86.8% vs 59.8%). Sepsis, volume depletion, shock, arrhythmias, and acute respiratory distress syndrome were higher in patients with acute kidney injury. Anticoagulation (85% vs 59.2%), vasopressors, plasma infusions, antimicrobials, and steroids were more frequently used in patients with acute kidney injury. More patients with acute kidney injury had acute respiratory failure requiring mechanical ventilation (62.3% vs 32.9%), with higher overall mortality rate (63.2% vs 31.1%).

CONCLUSIONS

We found more frequent prevalence of acute kidney injury associated with severe COVID-19 than shown in reports from Chinese, European, and North American cohorts. Patients with COVID-19 who developed acute kidney injury had risk factors such as hypertension and diabetes, greater need for mechanical ventilation, were males, and were older age. Mortality was high in this population, especially among older patients and those who developed Kidney Disease Improving Global Outcomes stage 3 disease.

Effect of SLCO1B1 genotypes on statin intolerance and response to statins

Background

Statins are a cornerstone therapy for management of hypercholesterolaemia in primary and secondary prevention of cardiovascular disease, however there is individual variation regarding efficacy of therapy and adverse side-effects experienced.

Purpose

Polymorphisms of the SLCO1B1 gene have shown correlation with the risk of statin side-effects and efficacy of treatment, however in real-world clinical practice, their utility remains to be established.

Methods

We carried out retrospective multiple linear regression analysis using robust standard errors of 129 individuals undergoing genetic testing for the SLCO1B1 polymorphisms rs4149056 and rs2306283 to investigate for an association to statin side effects and efficacy respectively. In addition, logistic regressions which account for the binary nature of the outcomes were performed. The rs4149056 gene has 3 outcomes: T/T (considered least associated with statin intolerance), C/C (considered most associated with statin intolerance) and T/C (considered intermediately associated with statin intolerance). The rs2306283 gene has 3 outcomes: A/A (considered least associated with statin response), G/G (considered most associated with statin response) and A/G (considered intermediately associated with statin response).

Results

According to multiple regression and logistic regression analyses SLCO1B1 rs4149056 genotypes (C/C and T/C relative to the base type T/T) do not predict the incidence of myalgia, myopathy, creatine kinase rise, liver function derangement or gastrointestinal side effects at 5% significance. SLCO1B1 rs2306283 (G/G and A/G relative to the base type A/A) do not predict LDL response to statins (p-values 0.33 and 0.52 respectively).

Conclusions

The presence of rs4149056 C/C and T/C genotypes was not associated with an increased risk of statin side-effects. Similarly rs2306283 genotypes did not correlate with the efficacy of statin treatment. These genotype predictors were primarily based on Simvastatin – an earlier generation statin, whereas the majority of the patients in this cohort were treated with more contemporary and widely used statins such as Atorvastatin and Rosuvastatin. We therefore conclude that these genotypic markers may have limited application in modern day clinical practice and that substantial investment of limited resources towards them may not be justified.

Funding Acknowledgement

Type of funding sources: None.

The Role of Perioperative Levosimendan in Patients with Reduced Ejection Fraction undergoing Cardiac surgery in Reducing Post-operative Hemodynamic Support

BACKGROUND: Acute perioperative left ventricular dysfunction is a major complication affecting patients subjected to cardiac surgery and is associated with increased mortality. Levosimendan as a “calcium sensitizers” with inodilator effect improves myocardial contractility by sensitizing troponin C to calcium without increasing myocardial oxygen consumption and without impairing relaxation and diastolic function. AIM: The aim of this study was to evaluate the effect of perioperative levosimendan compared to the conventional management used in the patient with poor left ventricular function undergoing cardiac surgery to reduce the need of post-operative pharmacological and mechanical circulatory support. METHODS: It is prospective observational studies were patients undergoing cardiac surgery divided into two groups of 25 patients each. The first group received conventional management while the other group received levosimendan additionally duration and type of post-operative pharmacological support, duration of mechanical ventilation, durations of ICU and hospital stays, and major outcomes, and data about the need of mechanical support were collected. RESULTS: In the levosimendan, fewer patients required vasoactive agents post-surgery (Noradrenaline) compared to the conventional group, yet the use of inotropic support (adrenaline) in the 2nd day and the need of mechanical circulatory support was equal in both groups. The mortality was equal in both groups. CONCLUSION: Perioperative levosimendan may reduce the need of vasoactive agents postoperatively, but it does not reduce the need of inotropic nor mechanical support.

New Concept of Power Generation Using TEGs: Thermal Modeling, Parametric Analysis, and Case Study

In this manuscript, an innovative concept of producing power from a thermoelectric generator (TEG) is evaluated. This concept takes advantage of using the exhaust airflow of all-air heating, ventilating, and air-conditioning (HVAC) systems, and sun irradiation. For the first step, a parametric analysis of power generation from TEGs for different practical configurations is performed. Based on the results of the parametric analysis, recommendations associated with practical applications are presented. Therefore, a one-dimensional steady-state solution for the heat diffusion equation is considered with various boundary conditions (representing applied configurations). It is revealed that the most promising configuration corresponds to the TEG module exposed to a hot fluid at one face and a cold fluid at the other face. Then, based on the parametric analysis, the innovative concept is recognized and analyzed using appropriate thermal modeling. It is shown that for solar radiation of 2000 W/m² and a space cooling load of 20 kW, a 40 × 40 cm² flat plate is capable of generating 3.8 W of electrical power. Finally, an economic study shows that this system saves about $6 monthly with a 3-year payback period at 2000 W/m² solar radiation. Environmentally, the system is also capable of reducing about 1 ton of CO₂ emissions yearly.

Effect of Levosimendan Compared to Conventional Inotropic Agents on Hemodynamics and Outcome in Patient with Poor LV Function Undergoing Cardiac Surgery

BACKGROUND

Patients undergoing heart surgery involving cardiopulmonary bypass (CPB) experience global myocardial ischemia with subsequent reperfusion which, despite cardioplegic protection, may result in different degrees of transient ventricular dysfunction. Levosimendan is a "calcium sensitisers", it improves myocardial contractility by sensitising troponin C to calcium without increasing myocardial oxygen consumption and without impairing relaxation and diastolic function.

AIM

To evaluate the adding effect of a calcium sensitiser (levosimendan) compared to the conventional inotropic and vasoactive agent used in the patient with poor left ventricular function undergoing cardiac surgery on different measured hemodynamic variables and the effect on the outcome.

METHODS

It is prospective observational studies were patients were divided into 2 groups of 30 patients each. The first Group received conventional inotropic and vasoactive treatment at different doses, while the other group received levosimendan additionally at a loading dose of 6-12mic/kg according to mean arterial pressure over 0.5 hr followed by 24 hrs infusion at 0.05 to 0.2 mic/kg/min. Hemodynamic data were collected at the end and 30 minutes after CPB, after that at 6, 12, 24, and 36 hours post CPB. Mean arterial pressure (MAP), central venous pressure (CVP), heart rate (HR), mixed venous saturation (Svo2), and base deficit (BD) were measured.

RESULTS

Levosimendan had significantly improved postoperative hemodynamic values as in the mixed venous pressure at different times postoperative (p < 0.05), also the base deficit at different times postoperative (p < 0.05), while there was a significant reduction in systemic vascular resistance as decreased mean arterial pressure in levosimendan group compared to conventional group at 6hrs postoperative mean 77.50 ± 10.81 vs 83.73 ± 10.81 with (p = 0.029), and at 12 hrs postoperative mean 77.37 ± 10.10vs 84.23 ± 13.81 with (p = 0.032), and there was no significant difference in heart rate at different times postoperative between both groups (p > 0.05), while there was no significant effect on mortality between both groups (p = 0.781).

CONCLUSION

Levosimendan had improved hemodynamic parameters significantly with no effect on mortality compared to conventional inotropic agents in a patient with poor left ventricular function undergoing cardiac surgery.

The accuracy of the auto-stop function of different endodontic devices in detecting the apical constriction

Background

Electronic apex locators (EALs) are modern devices used to determine the working length during root canal preparation. The newest endodontic motors provide an integrated EAL with auto-stop function to prevent instrumentation beyond the predefined working length during rotary root canal preparation. The aim of this study was to compare the accuracy of the auto-stop function of the VDW.Gold RECIPROC motor (VDW, Munich, Germany), the EndoPilot motor (Schlumbohm, Brokstedt, Germany) and the manual measurement with Raypex 6 (VDW, Munich, Germany) to detect the apical constriction (AC).

Methods

Ninety human teeth were chosen and randomly assigned to three experimental groups (30 teeth each): VDW.Gold RECIPROC motor continuous measuring (RCM), EndoPilot continuous measuring (ECM) and Raypex 6 manual measuring (RMM). When the measurement file reached the AC, the file was fixed in the tooth. The tooth was embedded in acrylic resin and the root tip was exposed, so that the histologic structure of the root canal and the file tip was visible for microscopic analysis. Afterwards, the distance of the file tip to the AC (D_AC) was automatically computed with a specially developed software tool.

Results

The mean D_AC were −13.18 μm (SD 88.46 μm) for RMM, −22.70 μm (SD 91.57 μm) for RCM and 18.74 μm (SD 88.11 μm) for ECM. The differences were not statistically significant (P = 0.181). The rates for instrumentation beyond the AC were not statistically different (Chi² = 4.753, p = 0.096).

Conclusions

All measurement methods showed a high accuracy in detecting the AC. The auto-stop function of these endodontic motors is a reliable addition to the endodontic armamentarium.

Episiotomy and obstetric perineal wound dehiscence: beyond soreness

Postpartum episiotomy dehiscence is a rare complication of vaginal delivery. Infection rates in episiotomy wounds are surprisingly low; however, it remains the most common cause of wound dehiscence, which may lead to major physical, psychological and social problems if left untreated. Most dehisced perineal wounds are left to heal naturally by secondary intention. This approach often results in a protracted period of significant morbidity for women. There is emerging evidence that early re-suturing closure of broken-down perineal wounds may have a better outcome, but randomised controlled trials are needed to yield evidence-based guidance for this management approach.

Removal of mercury from water by multi-walled carbon nanotubes

The removal of mercury (Hg(2+)) ions from contaminated water using multiwalled carbon nanotubes (MWCNTs) was investigated in this study. Results of the study showed that MWCNTs slurry was very efficient in removing as high as 1.0 mg/L of Hg(2+) from aqueous solutions via the adsorption mechanism. This removal efficiency was found to be a function of the aqueous pH level, dosage of CNTs, mixing rate, and contact time. The study showed that the Hg uptake by MWCNTs increased to 100% with an increase in pH from pH 4 to 8. The results also showed that higher dosage of MWCNTs, showed higher removal of Hg(2+). In a 50 mL water sample, 10 mg of MWCNTs was needed to remove all of the 0.1 mg/L of Hg(2+) ions. On the other hand, increasing the mixing rate from 50 to 150 rpm improved the removal efficiency. The experimental results also showed that mercury adsorption by MWCNTs follow a pseudo second-order reaction with a rate (k) of 0.018 and it is well described by the Langmuir isotherm model with maximum adsorptive capacity (q(max)) of 13.16.

[Effect of ketamine on prevention of postmastectomy chronic pain. A pilot study]

OBJECTIVE

This pilot study was designed to evaluate the feasibility of a trial to estimate the preventive effect of ketamine on postmastectomy pain syndrome (PMPS).

STUDY DESIGN

Double-blind, randomized, placebo-controlled pilot trial.

PATIENTS AND METHOD

Thirty six patients scheduled for a radical mastectomy with axillary lymph node dissection were randomized in two groups (n=18 per group). Before skin incision, a bolus (0.5 mg/kg of ketamine or placebo) followed by a continuous infusion (0.25 mg/kg per hour of ketamine or placebo) was administered and discontinued at the end of surgical procedure. We studied the incidence and characteristics of PMPS three months after surgery as well as the feasibility of chosen methods.

RESULTS

Thirty patients were followed for three months (group ketamine n=12; group placebo n=18). At three months, there was no significant difference in the incidence of chronic pain, but a tendency to a decrease of hyperalgesia near the scar. There was no repercussion on the quality of life. The characteristics of the PMPS are similar to those described in the recent literature (intercostobrachial neuralgia 33%, neuroma pain 39%, and phantom breast pain 22%). The feasibility of the experimental study is established by the absence of difficulty during the clinical investigation period.

CONCLUSION

We found no preventive effect of ketamine on the development of PMPS. However, the non-statistically significant effect of ketamine on hyperalgesia three months after surgery could justify a larger study with the same methodology.

PI3K mediates protection against TRAIL-induced apoptosis in primary human melanocytes

Melanocytes are cells of the epidermis that synthesize melanin, which is responsible for skin pigmentation. Transformation of melanocytes leads to melanoma, a highly aggressive neoplasm, which displays resistance to apoptosis. In this report, we demonstrate that TNF-related apoptosis-inducing ligand (TRAIL), which was thought to kill only transformed cells, promotes very efficiently apoptosis of primary human melanocytes, leading to activation of caspases 8, 9 and 3, and the cleavage of vital proteins. Further, we show that stem cell factor (SCF), a physiologic melanocyte growth factor that activates both the phosphatidyl-inositol-3 kinase (PI3K) and the extracellular regulated kinase (ERK) pathways, strongly protects melanocytes from TRAIL and staurosporine killing. Interestingly, inhibition of PI3K or its downstream target AKT completely blocks the antiapoptotic effect of SCF, while inhibition of ERK has only a moderate effect. Our data indicate that protection evoked by SCF/PI3K/AKT cascade is not mediated by an increase in the intracellular level of FLIP. Further, only a sustained PI3K activity can protect melanocytes from apoptosis, thereby indicating that the PI3K/AKT pathway plays a pivotal role in melanocyte survival. The results gathered in this report bring new information on the molecular mechanisms involved in primary melanocyte apoptosis and survival that would help to better understand the process by which melanomas acquire their resistance to apoptosis.

A prospective comparative study on IVF outcomes with either purified FSH or human menopausal gonadotrophin in downregulated normogonadotrophic women

OBJECTIVE

In compare the use of purified follicle-stimulating hormone with that of a preparation containing follicle-stimulating hormone and luteinizing hormone in infertile females undergoing IVF.

DESIGN

Open-labelled prospective controlled single-center study.

SETTING

Nile Badrawy IVF unit.

PARTICIPANTS

153 infertile females undergoing their first cycle of IVF divided into 2 groups.

INTERVENTIONS

Ovarian stimulation was done with either highly purified FSH for group 1 (n = 75) or human menopausal gonadotrophin group 2 (n = 78) after pituitary desensitization commenced in the midluteal phase of the preceding cycle. Monitoring was performed by ultrasound transvaginal oocyte retrieval followed by IVF and transfer of three embryos.

OUTCOMES

Number of oocytes >18 mm at day of hCG, fertilization rate, embryo transfer rate, clinical pregnancy rate and incidence of ovarian hyperstimulation syndrome.

RESULTS

The response to ovarian hyperstimulation was similar in both groups. The number of follicles >18 mm achieved at day of hCG was 12.3 +/- 0.9 (mean +/- SEM) following stimulation with 38.3 +/- 0.9 ampoules of Fostimon The Menogon-treated group needed 39.1 +/- 0.8 ampoules to produce 11.6 +/- 0.7 follicles. Fertilization rate (2PN/cell) was 58.6 vs. 64.2% in the Fostimon and Menogon group, respectively (p > 0.05). The number of embryos transferred per woman was 3.1 +/- 0.1 in the Fostimon group and 3.6 +/- 0.1 in the Menogon group. The pregnancy rate per woman was 33.3 vs. 25.6% in the Fostimon- and Menogon-treated groups, respectively (p > 0.05). Miscarriage rate was 16 vs 20%, respectively. However, the incidence of multiple pregnancies was significantly higher in the Fostimon-treated group (32%) vs. 10% only in the Menogon-treated group (p < 0.01).

CONCLUSION

Purified FSH yields similar clinical outcome to hMG in terms of oocytes retrieved and clinical pregnancies in a standard IVF regimen.

Antigen inhalation as a triggering factor in systemic small-sized-vessel vasculitis. Four cases

In order to identify small-sized-vessel vasculitis occurring immediately after massive inhalation of particles which could be considered antigenic, we performed a retrospective review of patients who consulted our Department of Internal Medicine between 1980 and 1998 and were diagnosed as having small-vessel vasculitis that developed immediately after massive exposure to inhaled particles. Four patients, 27 to 55 years old, presented with small-sized-vessel vasculitis (one with Wegener's granulomatosis and three with Churg-Strauss syndrome) which developed after massive inhalation of particles. Clinical manifestations occurred from a few hours to 10 days after inhalation of diesel fumes, cereal dust, flour or cereal dust and/or pigeon droppings. Three patients remain disease-free 8, 9 and 18 years after discontinuing treatment. One patient remains well after 3 years on low-dose corticosteroids and cyclophosphamide therapy. Our data suggest that primary antigens can cause small-sized-vessel vasculitides. Identifying such etiological factors could improve our understanding of the pathogenesis of systemic vasculitides and prevent relapses due to similar antigenic exposure.

[Conservative surgery for T2 > 3 cm, T3 N0 N1 M0 breast cancer after induction chemotherapy]

Induction chemotherapy (IC) provides in more than 20% of cases a complete shrinkage of the tumor. This down staging is a new challenge for the surgeons for breast conservative procedure. Although, IC has become the standard of care for breast cancer T2 > 3 cm T3 N0 N1 M0. No guidelines have devoted attention to the surgical problems due to this down staging after IC. Location and size of the tumor before IC have to be studied and outlined by the surgeon himself. During surgery, the residual tumor volume and how much mammary gland must be removed are very difficult to determine. The maximum volume of mammary gland to be removed after IC around the primary site of the tumor before IC is the volume which permits a good cosmetic reconstruction of the breast. After IC, in spite of an important downstaging, an axillary clearance must be done. For N0 patients, sentinel lymph node biopsy could be performed before IC. If the sentinel node is p N0, axillary clearance could be avoided.

[Lymph node mapping and axillary sentinel lymph node biopsy in 243 invasive breast cancers with no palpable nodes. The south Lyon hospital center experience]

STUDY AIM

To evaluate the effect of intraoperative lymph node mapping and sentinel lymph node dissection (SLND) on the axillary staging of patients with N0 breast carcinoma. Two techniques were used: blue dye alone (Evans Blue and Patent Blue) and combined technique (blue dye and isotope).

METHODS

The incidence of axillary node metastasis in axillary lymph node dissection (ALND) and SLND was compared prospectively. Multiple sections of each SLN were examined by HPS staining and immunohistochemical techniques. Two sections of each non sentinel node in ALND specimens were examined by routine HPS staining.

RESULTS

243 patients underwent ALND after SLN biopsy. The SLN detection rate was 225/243 cases (92.59%): 89.94% with blue dye alone and 100% with the combined technique. The false-negative rate was less than 2%.

CONCLUSION

SN biopsy is an accurate staging technique for N0 breast cancer. SLN biopsy with multiple sections and immunohistochemical staining of the SLN can identify significantly more patients with lymph node metastases than ALND with routine HPS staining.

Isolation of a second cryptic plasmid from Mycoplasma mycoides subsp. mycoides

Plasmids have rarely been detected in organisms constituting the genus Mycoplasma. Recently, the isolation of a cryptic plasmid from Mycoplasma mycoides subsp. mycoides has been described, and we report here the isolation of a second cryptic plasmid from this species. Restriction map and Southern blot analyses show that the second plasmid is distinct from the previously described plasmid, although a limited region of homology was detected. The availability of mycoplasmal cryptic plasmids may lead to the development of cloning vectors that replicate in these organisms.

Isoenzymes of beta-hexosaminidase from normal rat colon and colonic carcinoma

N-Acetyl-beta-D-hexosaminidase isolated from normal rat colon was compared to that obtained from a transplantable rat colonic carcinoma. Levels of total hexosaminidase from purified epithelial cells of normal colon were similar to those from purified malignant cells from the transplantable tumor. Cultured malignant cells had significantly higher levels of activity than did freshly purified tumor cells. Isoelectric focusing of hexosaminidase from normal rat colon indicated approximately equal amounts of A (pI 5.0 ) and B (pI 8.1) isoenzyme activity. The B isoenzyme (normal cell) was more stable to heat inactivation than was the A isoenzyme and had significantly higher activity at low pH's. In contrast, the B isoenzyme from the tumor was relatively unstable to heat and low pH.