Ruthenium on phosphorous-modified alumina as an effective and stable catalyst for catalytic transfer hydrogenation of furfural

Supported ruthenium was used in the liquid phase catalytic transfer hydrogenation of furfural. To improve the stability of Ru against leaching, phosphorous was introduced on a Ru/Al₂O₃ based catalyst upon impregnation with ammonium hypophosphite followed by either reduction or calcination to study the effect of phosphorous on the physico-chemical properties of the active phase. Characterization using X-ray diffraction, solid state ³¹P nuclear magnetic resonance spectroscopy, X-ray absorption spectroscopy, temperature programmed reduction with H₂, infrared spectroscopy of pyridine adsorption from the liquid phase and transmission electron microscopy indicated that phosphorous induces a high dispersion of Ru, promotes Ru reducibility and is responsible for the formation of acid species of Brønsted character. As a result, the phosphorous-based catalyst obtained after reduction was more active for catalytic transfer hydrogenation of furfural and more stable against Ru leaching under these conditions than a benchmark Ru catalyst supported on activated carbon.

Phosphorous induces structural changes in Ru/Al₂O₃ that make it more active and more stable for liquid phase hydrogenation of furfural.     

Topical use of tranexamic acid: Are there concerns for cytotoxicity?

Tranexamic acid (TXA) has revolutionized modern blood management in orthopaedic surgery, especially in total joint arthroplasty, by significantly reducing blood loss and transfusion rates. It is an antifibrinolytic agent and a synthetic derivative of the amino acid lysine, which can inhibit the activation of plasminogen and the fibrin breakdown process. The administration of TXA can be intravenous (IV), topical, and oral. In patients where the IV administration is contraindicated, topical use is preferred. Topical administration of the drug theoretically increases concentration at the operative site with reduced systemic exposure, reduces cost, and gives the surgeon the control of the administration. According to recent studies, topical administration of TXA is not inferior compared to IV administration, in terms of safety and efficacy. However, there are concerns regarding the possible toxicity in the cartilage tissue with the topical use of TXA mainly in hemiarthroplasty operations of the hip, unilateral knee arthroplasties, total knee arthroplasties where the patella is not resurfaced, and other intraarticular procedures, like anterior cruciate ligament reconstruction. The purpose of the present review is to present all the recent updates on the use of TXA focusing on the toxicity on chondrocytes and the articular cartilage that may or may not be provoked by the topical use of TXA.     

A Physiological Controller for Turbodynamic Ventricular Assist Devices Based on Left Ventricular Systolic Pressure

The current article presents a novel physiological feedback controller for turbodynamic ventricular assist devices (tVADs). This controller is based on the recording of the left ventricular (LV) pressure measured at the inlet cannula of a tVAD thus requiring only one pressure sensor. The LV systolic pressure (SP) is proposed as an indicator to determine the varying perfusion requirements. The algorithm to extract the SP from the pump inlet pressure signal used for the controller to adjust the speed of the tVAD shows robust behavior. Its performance was evaluated on a hybrid mock circulation. The experiments with changing perfusion requirements were compared with a physiological circulation and a pathological one assisted with a tVAD operated at constant speed. A sensitivity analysis of the controller parameters was conducted to identify their limits and their influence on a circulation. The performance of the proposed SP controller was evaluated for various values of LV contractility, as well as for a simulated pressure sensor drift. The response of a pathological circulation assisted by a tVAD controlled by the introduced SP controller matched the physiological circulation well, while over‐ and underpumping events were eliminated. The controller presented a robust performance during experiments with simulated pressure sensor drift.     

The role of adipocytokines in insulin resistance in normal pregnancy: visfatin concentrations in early pregnancy predict insulin sensitivity

BACKGROUND: Throughout pregnancy maternal adipose tissue is metabolically active, producing adipocytokines involved in the process of insulin resistance. We explored the role of serum adipocytokines, including the newly identified adipocytokine visfatin, in the process of insulin resistance in normal pregnancy. METHODS: We examined 80 pregnant nonobese, nondiabetic white women during the 3 trimesters of pregnancy. All study participants underwent anthropometric measurements, adipocytokine evaluation, and a 75-g oral glucose tolerance test. Homeostasis mathematical model assessment (HOMA-R), insulin sensitivity index (ISI), and indices of beta-cell secretion were calculated. RESULTS: Maternal weight, percentage total body fat, hip circumference, and indices of beta-cell secretion increased significantly during the 3 trimesters, and HOMA-R and ISI increased and decreased, respectively, in the 3rd trimester. During early pregnancy, insulin resistance, beta-cell secretion, and weight correlated positively with leptin. During the 1st trimester, visfatin correlated negatively with percentage body fat and was the best positive predictor of 2nd trimester ISI. In the 2nd trimester, serum visfatin was the best negative predictor of percentage body fat. CONCLUSIONS: During normal pregnancy of nonobese, nondiabetic women, adipose tissue increases, accompanied by a significant progressive increase of insulin resistance. Visfatin concentrations in the 1st trimester positively predict insulin sensitivity during the 2nd trimester. Body fat mass during 1st trimester of pregnancy is negatively associated with insulin sensitivity during the 2nd trimester and perhaps should be kept under control.     

Association between MRI findings and clinical outcomes in a period of 5 years after lumbar spine microdiscectomy

European Journal of Orthopaedic Surgery & Traumatology - To evaluate the associations between magnetic resonance imaging (MRI) findings and pain, disability and quality of life before surgery...     

Dermal scarification versus intramuscular diclofenac sodium injection for the treatment of renal colic: a prospective randomized clinical trial

The aim of the study is to determine whether dermal scarification is equally effective for treating acute renal colic compared to diclofenac sodium intramuscular therapy. A prospective, randomized controlled study was conducted with methodologic rigor based on CONSORT criteria. A total of 291 patients, aged ≥18 years, suffering from acute renal colic were included in this trial and randomly assigned in two groups. Patients in the first group (A) received endodermal injection (dermal scarification) of 1 ml normal saline at the area of intensity of pain. The second group (B) received 75 mg diclofenac sodium by intramuscular injection. The success of each method defined the primary end point. Pain intensity before and after treatment was assessed using a visual analog scale. The time onset and the duration of analgesia were also recorded. There was no significant difference between the two groups regarding hematuria (p = 0.158), stone identification at KUB (p = 0.751) and mean pain intensity (p = 0.609) before treatment initiation. The method was successful in 75.5 % of patients in group A and 74.3 % of patients in group B (p = 0.812). Mean pain reduction was comparable, 5.65 ± 3.05 in group A and 5.34 ± 2.99 in group B (p = 0.379), with dermal scarification eliciting its effect considerably faster, whereas the duration of analgesia was longer in the diclofenac group (p < 0.05). In conclusion, dermal scarification could constitute an alternative method for treating renal colic as it is equally effective compared to the standard treatment of diclofenac sodium.     

Sex-related aspects of the red blood cell storage lesion

BackgroundSeveral factors contribute to the manifestation of red blood cell (RBC) storage lesions, with one of the most interesting being the “donor variation effect”. Since many haematological characteristics of blood donors are sex-dependent, sex hormones and their age-dependent variation may affect the storage profile of RBCs.Materials and methodsFresh blood from 200 healthy male and female donors underwent haematological, biochemical and physiological analysis. Three selected groups of donors (men, n=8; pre-menopausal women, n=8; and post-menopausal women, n=4) exhibiting as similar as possible baseline values were recruited for blood donation in leukoreduced CPD/SAGM units. RBC indices, haemolysis and propensity for haemolysis, reactive oxygen species (ROS) and plasma antioxidant capacity were measured bi-weekly.ResultsFemale blood was characterised by lower plasma antioxidant capacity and free haemoglobin (Hb) levels in vivo, in spite of the higher RBC osmotic fragility, compared to male blood. Comparatively low Hb concentration was also measured in stored RBCs from female donors, as in vivo. Mean corpuscular Hb (MCH), mean corpuscular Hb concentration (MCHC), and plasma antioxidant capacity were also lower in female donors throughout storage, even though baseline levels were equal to those of the male group. There was no difference in propensity of stored RBCs for haemolysis between male and female units but intracellular ROS levels were significantly lower in female RBCs. Increased end-of-storage extracellular potassium and recruitment of protein stress markers (clusterin, Hb) to the RBC membrane were observed in the units of post- vs pre-menopausal female donors at mid-storage onwards.DiscussionDonor’s sex has an impact on Hb concentration and redox parameters of stored RBCs. In addition, menopause seems to promote RBC membrane remodelling, at least during prolonged storage. Our pilot study provides new insights on the different effects on RBC storage lesion according to sex.