RÉSUMÉ
Climate change caused by the greenhouse gases CO2 remains a topic of global concern. To mitigate the excessive levels of anthrophonic CO2 in the atmosphere, CO2 capture methods have been developed and among these, adsorption is an especially promising method. This paper presents a series of amine functionalized biochar obtained from desiccated coconut waste (amine-biochar@DCW) for use as CO2 adsorbent. They are ethylenediamine-functionalized biochar@DCW (EDA-biochar@DCW), diethylenetriamine-functionalized biochar@DCW (DETA-biochar@DCW), triethylenetetramine-functionalized biochar@DCW (TETA-biochar@DCW), tetraethylenepentamine-functionalized biochar@DCW (TEPA-biochar@DCW), and pentaethylenehexamine-functionalized biochar@DCW (PEHA-biochar@DCW). The adsorbents were obtained through amine functionalization of biochar and they are characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, Brunauer-Emmett-Teller (BET), and thermogravimetric analysis (TGA). The CO2 adsorption study was conducted isothermally and using a thermogravimetric analyzer. From the results of the characterization analyses, a series of amine-biochar@DCW adsorbents had larger specific surface area in the range of 16.2 m2/g-37.1 m2/g as compare to surface area of pristine DCW (1.34 m2/g). Furthermore, the results showed an increase in C and N contents as well as the appearance of NH stretching, NH bending, CN stretching, and CN bending, suggesting the presence of amine on the surface of biochar@DCW. The CO2 adsorption experiment shows that among the amine modified biochar adsorbents, TETA-biochar@DCW has the highest CO2 adsorption capacity (61.78 mg/g) when using a mass ratio (m:m) of biochar@DCW:TETA (1:2). The adsorption kinetics on the TETA-biochar@DCW was best fitted by the pseudo-second model (R2 = 0.9998), suggesting the adsorption process occurs through chemisorption. Additionally, TETA-biochar@DCW was found to have high selectivity toward CO2 gas and good reusability even after five CO2 adsorption-desorption cycles. The results demonstrate the potential of novel CO2 adsorbents based on amine functionalized on desiccated coconut waste biochar.
Sujet(s)
Dioxyde de carbone , Cocos , Dioxyde de carbone/composition chimique , Porosité , Charbon de bois , Spectroscopie infrarouge à transformée de Fourier , Trientine , Adsorption , CinétiqueRÉSUMÉ
BACKGROUND: We aimed to evaluate the efficacy of midodrine as a prophylaxis against post-spinal hypotension in elderly patients undergoing hip arthroplasty. METHODS: This randomized controlled trial included elderly patients undergoing hip arthroplasty under spinal anesthesia. Ninety minutes before the procedure, patients were randomized to receive either 5-mg midodrine or placebo (metoclopramide). After spinal anesthesia, mean arterial pressure (MAP) and heart rate were monitored every 2 min for 20 min then every 5 min until the end of the procedure. Post-spinal hypotension (MAP < 80% baseline) was treated with 10 mg ephedrine. The primary outcome was intraoperative ephedrine consumption. Secondary outcomes were the incidence of post-spinal hypotension, bradycardia, and hypertension (MAP increased by > 20% of the baseline reading). RESULTS: We analyzed 29 patients in the midodrine group and 27 in the control group. The intraoperative ephedrine consumption was lower in the midodrine group than in the control group (median [quartiles]: 10 [0, 30] mg versus 30 [20, 43] mg, respectively, P-value: 0.002); and the incidence of intraoperative hypotension was lower in the midodrine group than that in the control group. The incidence of hypertension and bradycardia were comparable between the two groups. CONCLUSION: The use of 5 mg oral midodrine decreased the vasopressor requirements and incidence of hypotension after spinal anesthesia for hip surgery in elderly patients. CLINICAL TRIAL REGISTRATION: This study was registered on September 22, 2022 at clinicaltrials.gov registry, NCT05548985, URL: https://classic. CLINICALTRIALS: gov/ct2/show/NCT05548985 .
Sujet(s)
Rachianesthésie , Arthroplastie prothétique de hanche , Hypertension artérielle , Hypotension artérielle , Midodrine , Humains , Sujet âgé , Midodrine/usage thérapeutique , Éphédrine/usage thérapeutique , Rachianesthésie/effets indésirables , Rachianesthésie/méthodes , Bradycardie/épidémiologie , Bradycardie/prévention et contrôle , Bradycardie/complications , Arthroplastie prothétique de hanche/effets indésirables , Hypotension artérielle/épidémiologie , Vasoconstricteurs , Hypertension artérielle/complications , Méthode en double aveugleRÉSUMÉ
BACKGROUND: Lung fibrosis is considered as an end stage for many lung diseases including lung inflammatory disease, autoimmune diseases and malignancy. There are limited therapeutic options with bad prognostic outcome. The aim of this study was to explore the effect of mesenchymal stem cells (MSCs) derived from bone marrow on Bleomycin (BLM) induced lung fibrosis in albino rats. METHODS: 30 adult female albino rats were distributed randomly into 4 groups; negative control group, Bleomycin induced lung fibrosis group, lung fibrosis treated with bone marrow-MSCs (BM-MSCs) and lung fibrosis treated with cell free media. Lung fibrosis was induced with a single dose of intratracheal instillation of BLM. BM-MSCs or cell free media were injected intravenously 28 days after induction and rats were sacrificed after another 28 days for assessment. Minute respiratory volume (MRV), forced vital capacity (FVC) and forced expiratory volume 1 (FEV1) were recorded using spirometer (Power lab data acquisition system). Histological assessment was performed by light microscopic examination of H&E, and Masson's trichrome stained sections and was further supported by morphometric studies. In addition, electron microscopic examination to assess ultra-structural changes was done. Confocal Laser microscopy and PCR were used as tools to ensure MSCs homing in the lung. RESULTS: Induction of lung fibrosis was confirmed by histological examination, which revealed disorganized lung architecture, thickened inter-alveolar septa due excessive collagen deposition together with inflammatory cellular infiltration. Moreover, pneumocytes depicted variable degenerative changes. Reduction in MRV, FVC and FEV1 were recorded. BM-MSCs treatment showed marked structural improvement with minimal cellular infiltration and collagen deposition and hence restored lung architecture, together with lung functions. CONCLUSION: MSCs are promising potential therapy for lung fibrosis that could restore the normal structure and function of BLM induced lung fibrosis.
Sujet(s)
Transplantation de cellules souches mésenchymateuses , Cellules souches mésenchymateuses , Fibrose pulmonaire , Animaux , Bléomycine/toxicité , Moelle osseuse , Femelle , Fibrose pulmonaire/induit chimiquement , RatsRÉSUMÉ
OBJECTIVES: Tracheostomy is a very common clinical intervention in critically ill adult patients. The indications for tracheostomy procedures in pediatric patients with complex conditions have increased dramatically in recent years, but there are currently no guidelines on the optimal timing of tracheostomy in pediatric patients undergoing prolonged ventilation. DATA SOURCES: We performed a systematic search of the existing literature in MEDLINE via PubMed and Embase databases and the Cochrane Library to identify clinical trials, observational studies, and cohort studies that compare early and late tracheostomy in children. The date of the last search was August 27, 2018. Included articles were subjected to manual searching. STUDY SELECTION: Studies in mechanically ventilated children that compared early with late tracheostomy were included. DATA EXTRACTION: Data were extracted into a spreadsheet and copied into Review Manager 5.3 (The Cochrane Collaboration, Copenhagen, Denmark). DATA SYNTHESIS: Data were meta-analyzed using an inverse variance, random effects model. Continuous outcomes were calculated as mean differences with 95% CIs, and dichotomous outcomes were calculated as Mantel-Haenszel risk ratios with 95% CIs. We included eight studies (10 study arms). These studies were all retrospective cohort studies. Early tracheostomy was associated with significant reductions in mortality, days on mechanical ventilation, and length of intensive care and total hospital stay, although the lack of randomized, controlled trials limits the validity of these findings. Although variance was imputed for some studies, these conclusions did not change after removing these studies from the analysis. CONCLUSIONS: In children on mechanical ventilation, early tracheostomy may improve important medical outcomes. However, our data demonstrate the urgent need for high-quality, randomized controlled trials in the pediatric population.
Sujet(s)
Ventilation artificielle/statistiques et données numériques , Trachéostomie/méthodes , Adolescent , Enfant , Enfant d'âge préscolaire , Soins de réanimation , Maladie grave , Humains , Nourrisson , Unités de soins intensifs , Durée du séjour , Études rétrospectives , Facteurs temps , Trachéostomie/mortalitéRÉSUMÉ
OBJECTIVE: Bleeding is a leading cause of death among trauma patients. Delayed assessment of blood hemoglobin level might result in either unnecessary blood transfusion in nonindicated patients or delayed blood transfusion in critically bleeding patients. In this study, we evaluate the precision of noninvasive hemoglobin monitoring in trauma patients with low hemoglobin levels. METHODS: We included trauma patients with low hemoglobin levels (less than 8âg/dL) scheduled for surgical intervention. Blood samples were obtained on admission and after each blood unit with concomitant measurement of serum hemoglobin using radical-7 Masimo device. The change in blood hemoglobin after every transfused blood unit was also assessed by both methods (change in noninvasive Masimo hemoglobin [Delta-Sp-Hb] and change in laboratory hemoglobin [Delta-Lab-Hb]). The precision of Masimo hemoglobin level (Sp-Hb) compared with Laboratory hemoglobin level (Lab-Hb) was determined using both Bland-Altman and Pearson correlation analyses. RESULTS: One hundred eighty-four time-matched samples were available for final analysis. Bland-Altman analysis showed excellent accuracy of Sp-Hb compared with Lab-Hb with mean bias of 0.12âg/dL and limits of agreement between -0.56âg/dL and 0.79âg/dL. Excellent correlation was reported between both measures with Pearson correlation coefficient of 0.872. Excellent agreement was also reported between both Delta-Sp-Hb and Delta-Lab-Hb with mean bias of -0.05 and limits of agreement from -0.62 to 0.51 CONCLUSIONS:: Sp-Hb showed accurate precision in both absolute values and trend values compared with Lab-Hb measurement in trauma patients with low hemoglobin levels.
Sujet(s)
Hémoglobines/métabolisme , Plaies et blessures/sang , Plaies et blessures/métabolisme , Adulte , Femelle , Hémorragie/métabolisme , Hémorragie/thérapie , Humains , Mâle , Adulte d'âge moyen , Études prospectives , Plaies et blessures/thérapieRÉSUMÉ
BACKGROUND: Although cardiac injury has been reported in patients with various neurological conditions, few data report cardiac injury in patients with traumatic brain injury (TBI). The aim of this work is to report the incidence of cardiac injury in patients with TBI and its impact on patient outcome. METHODS: A prospective observational study was conducted on a cohort of 50 patients with severe TBI. Only patients with isolated severe TBI defined as Glascow coma scale (GCS) < 8 were included in the study. Acute physiology and chronic health evaluation (APACHE) II score, GCS, hemodynamic data, serum Troponin I, electrocardiogram (ECG), and echocardiographic examination, and patients' outcome were recorded. A neurogenic cardiac injury score (NCIS) was calculated for all patients (rising troponin = 1, abnormal echocardiography = 1, hypotension = 1). Univariate and multivariate analyses for risk factors for mortality were done for all risk factors. RESULTS AND DISCUSSION: Fifty patients were included; age was 31 ± 12, APACHE II was 21 ± 5, and male patients were 45 (90 %). Troponin I was elevated in 27 (54 %) patients, abnormal echocardiography and hypotension were documented in 14 (28 %) and 16 (32 %) patients, respectively. The in-hospital mortality was 36 %. Risk factors for mortality by univariate analysis were age, GCS, APACHE II score, serum troponin level, NCIS, and hypotension. However, in multivariate analysis, the only two independent risk factors for mortality were APACHE II score (OR = 1.25, 95 % confidence interval: 1.02-1.54, P = 0.03) and NCIS score (OR = 8.38, 95 % confidence interval: 1.44-48.74, P = 0.018). CONCLUSIONS: Cardiac injury is common in patients with TBI and is associated with increased mortality. The association of high NCIS and poor outcome in these patients warrants a further larger study.