Dissolution Behavior of Cellulose In The Binary Solvent of Polar Aprotic Solvent And TBAA

We have found that cellulose could be dissolved rapidly in the binary solvent of polar aprotic solvents (PAS) and tetrabutylammonium acetate (TBAA) in a high solubility. The polar aprotic solvents includes dimethyl sulfoxide, pyridine, dimethylacetamide, dimethylformamide and N-Methyl-2-pyrrolidone. The factors affecting the dissolution behavior of cellulose was investigated and it is indicated that the solubility and dissolution rate of cellulose in the binary solvent are significantly dependent on the species of PAS and the molar ratio of PAS/TBAA. Among all the polar aprotic solvents, dimethyl sulfoxide is the best one, being attributed to its high diffusivity and strong solvation ability. The optimal molar ratio of PAS/TBAA was determined by donor number of the polar aprotic solvents. The dissolution of cellulose in the binary solvent was proposed to involve three processes, namely solvent diffusion, solvation of TBAA as well as disruption of the intermolecular or intramolecular hydrogen bonds (H-bonds) of cellulose.

Revisit of Optimal Donor Number Estimation in the Hong Kong Bone Marrow Donor Registry

High resolution typing of the HLA-DPB1 locus for patient who requested for hematopoietic stem cell transplantation (HSCT) workup has recently become mandatory by the National Marrow Donor Program (NMDP) in order to facilitate matching between donors and recipients for better outcomes. The likelihood of identifying HLA matched donors in Hong Kong, on top of the existing HLA-A, -B, -C, and -DRB1 loci, is revisited in this study. HLA-A, -B, -C, -DRB1 and -DPB1 genotypes of 5,266 volunteer unrelated Chinese donors from the Hong Kong Bone Marrow Donor Registry (HKBMDR), were included in this study. Matching models were employed to determine the matching probabilities for 10/10(DPB1) and 9/10(DPB1) HLA match. The matching probabilities are 20% at 10/10(DPB1) HLA match and 55% at 9/10(DPB1) match, based on the existing 130,000 donors in the HKBMDR. The likelihoods of match become 27% and 65% respectively, by increasing the registry to 250,000. However, if DPB T-cell-epitope (TCE) model is considered in the matching, the probability will increase to 46% at 10/10 DPB1 permissive mismatching. Our findings provide vital information about the future planning on the targeted recruitment size, HLA typing and search strategies of the donor registry and arose the transplant physicians’ acceptability to 9/10(DBP1) or 10/10(DBP1) HLA match. Nevertheless, the marrow donor registry has planned for increasing the registry size and bringing down the age of recruited donors which will ultimately enhance patient outcome.

Risk Factors of Ureteral Stenosis in Kidney Transplant Recipients: A Retrospective Study in National Referral Hospital in Indonesia

Ureteral stenosis is one of the most common urological complications following kidney transplantations. It is occurred in 2–10% of patients and poses a significant problem to the patients as it may lead to permanent damage to renal damage. Identification of risk factors is important to prevent the incidence of ureteral stenosis. Thus, we aim to determine the risk factors of ureteral stenosis in the Indonesian population. This is a retrospective analysis of 487 kidney transplant patients performed in Cipto Mangunkusumo Hospital between 2014 and 2018. We collected and compared donor and recipient demography data in recipients who developed ureteral stenosis and recipients who did not develop ureteral stenosis. Ureteral stenosis was defined as the presence of hydronephrosis from ultrasound and increased number of serum creatinine. The overall incidence of ureteral stenosis post-kidney transplantation in our center is 6.6% (32 from 487 patients) from January 2014 until June 2018. We found that older donor and recipient age more frequent in developing ureteral stenosis post-kidney transplantation ( p < 0.001). We also found that donors with number of arteries more than 2 ( p < 0.001) and prolonged warm ischemic time ( p < 0.05) are more frequently to develop ureteral stenosis post-kidney transplantation. There is no association between type II diabetes mellitus and hypertension with ureteral stenosis in this study. Donor age, recipient age, donor number of arteries more than 2, and prolonged warm ischemia time are associated with ureteral stenosis after kidney transplantation.

An Inorganic-rich SEI Induced by LiNO3 Additive for Stable Lithium Metal Anode in Carbonate Electrolyte

The dissolution of LiNO3 in carbonate electrolytes is achieved by introducing pyridine as a new carrier solvent owing to its higher Gutmann donor number than NO3-. The Li metal anode...

Using computational chemistry to explore experimental solvent parameters – solvent basicity, acidity and polarity/polarizability

Solvent basicity and polarity/polarizability parameters are analysed using molecular properties of solvents derived from computational chemistry. The results show that Kamlet and Taft’s measure of hydrogen bond basicity, β, is essentially identical to Gutmann’s donor number, a measure of Lewis basicity, both being determined by the charge on the most negative atom of the solvent molecule and the energy of the electron donor orbital. It is also found that, for both parameters, the calculated values for alcohols and N–H containing bases deviate systematically from those for aprotic solvents. This mirrors Kamlet and Taft’s earlier observation that different solvatochromic probes yield different β values in amphiprotic solvents. Reichardt’s ET (30) and Kamlet, Abboud and Taft’s π* both show direct dependences on the dipole moments and quadrupolar amplitudes of the solvent molecules and, surprisingly, an inverse dependence on the molecular polarizability. Additionally, ET (30) has a strong dependence on the charge on the most positive hydrogen atom of the solvent molecule, reflecting its sensitivity to hydrogen bonding. Unexpectedly, π* shows a dependence on the energy of the electron donor orbital. Kammet and Taaft’s hydrogen bond acidity parameter, α, is discussed in light of the results for π* and ET (30).

Exclusive solution discharge in Li-O2 batteries

<b>Electrodepositing insulating and insoluble Li2O2 is the key process during discharge of aprotic Li-O2 batteries and determines rate, capacity, and reversibility. Current understanding states that the partition between surface adsorbed and solvated LiO2 governs whether Li2O2 grows as surface film or particles, leading to low or high capacities, respectively. Here we show that Li2O2 forms exclusively as particles via solution mediated LiO2 disproportionation. We describe a unified O2 reduction mechanism that conclusively explains capacity limitations across the whole range of electrolytes. Low-donor-number electrolytes are shown to accelerate disproportionation rather than slowing it down. Deciding for particle morphology and achievable capacities are species mobilities, true areal rate and the rate at which associated LiO2 forms in solution. Provided that species mobilities and surface are high, this allows for high capacities even with low-donor-number electrolytes, previously considered prototypical for low capacity via surface growth. The tools for these insights include microscopy, hydrodynamic voltammetry, a numerical reaction model, and in situ small/wide angle X-ray scattering (SAXS/WAXS). Combined with sophisticated data analysis, SAXS allows retrieving rich quantitative information from complex multi-phase systems. On a wider perspective, this SAXS method is a powerful in situ metrology with atomic to sub-micron resolution to study mechanisms in complex electrochemical systems and beyond.<br></b>

Acute Hemolytic Transfusion Reaction Due to Pooled Platelets: A Rare but Serious Adverse Event

A female patient aged 65 years with blood group A with relapsed lymphoma had thrombocytopenia; leukocyte-reduced group O prestorage pooled platelet concentrates (PPLTs) were transfused without adverse events. She was discharged home, but 1.5 hours later she returned with fever and dark urine. Hypotension and tachycardia developed; she was admitted to the intensive care unit. Post-transfusion blood and urine samples were obtained. Serial dilutions from 5 donor testing tubes and a simulated PLT pool were performed and read at immediate spin and IgG. Testing confirmed an acute hemolytic transfusion reaction (AHTR): elevated lactate dehydrogenase (996 U/L; normal range 135 U/L–225 U/L) and undetectable haptoglobin (&lt;10 mg/dL; normal range 30 mg/dL–200 mg/dL) levels. Urinalysis showed dark amber urine but no significant quantity of red blood cells. At 37ºC the simulated pool and donor number 5 had high-titer anti-A. As a precaution, the donor was permanently deferred. Research has shown that PLT-associated AHTR has occurred with apheresis platelets but is very rare with whole blood–derived PLTs.