Homogeneous and heterogeneous molecular catalysts for electrochemical reduction of carbon dioxide

Carbon dioxide (CO₂) is a greenhouse gas whose presence in the atmosphere significantly contributes to climate change. Developing sustainable, cost-effective pathways to convert CO₂ into higher value chemicals is essential to curb its atmospheric presence. Electrochemical CO₂ reduction to value-added chemicals using molecular catalysis currently attracts a lot of attention, since it provides an efficient and promising way to increase CO₂ utilization. Introducing amino groups as substituents to molecular catalysts is a promising approach towards improving capture and reduction of CO₂. This review explores recently developed state-of-the-art molecular catalysts with a focus on heterogeneous and homogeneous amine molecular catalysts for electroreduction of CO₂. The relationship between the structural properties of the molecular catalysts and CO₂ electroreduction will be highlighted in this review. We will also discuss recent advances in the heterogeneous field by examining different immobilization techniques and their relation with molecular structure and conductive effects.

Electroreduction of CO₂ to CO using molecular catalysis.     

Changes of electrocardiogram and hemodynamics in response to dipyridamole: In vivo comparative analyses using anesthetized beagle dogs and microminipigs

Microminipigs are expected as a novel animal model for cardiovascular pharmacological experiments. Since inherent vulnerability of coronary circulation of microminipigs has not been characterized, we performed dipyridamole-stress test to both microminipigs and beagle dogs, and compared the results. Dipyridamole in doses of 0.056 and 0.56 mg/kg were intravenously infused over 10 min (n = 4 for each animal). Dipyridamole decreased the systolic/diastolic blood pressures and double product in dogs as well as in microminipigs; but it did not significantly alter the heart rate or the global balance between the myocardial oxygen demand and supply in either animal. While organic coronary arterial stenosis was not detected in either animal, dogs have well-developed epicardial intracoronary networks unlike microminipigs. Like in humans, dipyridamole did not affect the ST segment of microminipigs, whereas it substantially depressed that in dogs. The results indicate the onset of subendocardial ischemia by dipyridamole in dogs may be partly associated with their well-developed native coronary collateral channels. Microminipigs would be more useful to evaluate the drugs which may affect the coronary circulation in the pre-clinical study than dogs.     

A new approach to alar rim defects: mucocartilaginous turnover flap

The main principle of reconstructive surgery is replacement of the defective tissues with like tissues. A full-thickness defect of the nasal ala should be reconstructed in three layers: innermost mucosal layer, outermost skin, and the cartilage in-between. The aim of this study is to describe a technique for single-stage, three-layer reconstruction of the full-thickness ala nasi defects. This technique was used on three patients with tumors involving the nasal ala. Resulting full-thickness defects are reconstructed with a mucocartilaginous turnover flap planned from the contralateral side. Aesthetically acceptable results are obtained without the compromise of the nasal airway and with minimal donor site morbidity. None of the patients requested a revision operation. In conclusion, this is a novel technique with minimal donor site morbidity and good postoperative results. Moreover, lost tissues are replaced with exactly the same kind of tissues.     

Relationship between left ventricle geometric patterns and lymphocyte DNA damage in patients with untreated essential hypertension

OBJECTIVE: To investigate the association between different the left ventricle (LV) geometric patterns and lymphocyte DNA damage in patients with hypertension (HT). METHODS: We studied 84 patients (50.0+/-6.1, years) with HT and 24 healthy control subjects (48.6+/-3.3, years). Four different geometric patterns were identified in patients according to LV mass index and relative wall thickness. Peripheral lymphocyte DNA damages and plasma levels of total antioxidant status (TAS) were determined in all subjects. RESULTS: DNA damage was increased in hypertensive patients compared with control group (p=0.001). The major increase in DNA damage was observed in concentric hypertrophic geometric pattern compared with all other geometric patterns (p<0.001, for all). In multiple linear regression analysis, lymphocyte DNA damage was independently correlated with only TAS (beta=-0.444, p<0.001), but not LV geometry (p>0.05). CONCLUSION: The major increase in lymphocyte DNA damage was observed in concentric hypertrophic geometric pattern. This result may be related to increased oxidative stress.     

Investigation of serum vitamin D and ischaemia-modified albumin levels in infertile Turkish men

Our aim was to explore the existence of a possible relationship of sperm motility with serum 25-hydroxyvitamin D3 (25-OH VD) levels and with ischaemia-modified albumin ( IMA) levels in infertile Turkish men. A total of 30 men with nonobstructive azoospermia (no spermatozoa in ejaculate), 30 men with oligospermia (total progressive motile sperm count (TPMSC) <15 × 10⁶/ml) and 33 fertile men with normospermia (with at least one child, as the control group) were enrolled in the study. The mean 25-OH VD levels for groups 1, 2 and 3 were 9.31 ± 6.46, 19.71 ± 12.80 and 30.52 ± 12.49 respectively (p < .05). There was a statistically significant difference in serum IMA levels among the groups (479.32 ± 307.56 vs. 296.37 ± 127.27 vs. 150.04 ± 81.05, respectively; p < .05). A positive correlation between serum 25-OH VD levels and TPMSC, and a negative correlation between TPMSC and serum IMA levels were determined. Infertile men had lower serum 25-OH VD and higher IMA levels than fertile men, with a positive correlation between serum 25-OH VD levels and TPMSC, and a negative correlation between TPMSC and serum IMA levels. Vitamin D supplementation may increase the sperm motility.