Intensification of dilute acid hydrolysis of spent tea powder using ultrasound for enhanced production of reducing sugars.

Spent tea (ST) powder is one of the potential sustainable sources available abundantly and can be utilized to produce reducing sugars required for production of platform chemicals. The current study aims at intensifying the reducing sugars production based on ultrasound assisted dilute acid hydrolysis (UADAH). The effects of reaction time, solid liquid ratio, acid concentration and temperature on the yield of reducing sugars were investigated initially for UADAH process based on ultrasonic (US) horn. The highest yield of 24.75 g/L for the reducing sugars was obtained at solid liquid ratio of 1:8, acid concentration of 1% w/v and temperature of 60 °C within 120 min. Use of oxidants like hydrogen peroxide (H2O2) and Fenton's reagent to further intensify the production has also been studied. Use of H2O2 at optimum loading of 0.75 g/L resulted in reducing sugars yield of 26.2 g/L within 75 min while using same H2O2 loading with FeSO4 at loading of 0.75 g/L along with UADAH reduced the reaction time to 60 min for almost similar yield. Large scale studies performed using US flow cell revealed that yield of reducing sugars as 22.4 g/L is obtained in 120 min in the case of only UADAH, while in the case of UADAH along with H2O2 and Fenton's reagent, similar yield of reducing sugars was obtained in only 90 and 60 min respectively. UADAH in combination with oxidants has been demonstrated as an effective and intensified approach to produce reducing sugars from spent tea powder available as sustainable source.

Refractory Vasospastic Angina: When Typical Medications Don't Work.

Vasospastic angina (VSA) is defined as spasm of the coronaries leading to transient constriction and eventual myocardial ischemia. VSA is treated typically with calcium-channel blockers (CCBs) and nitrates. However, there are times when the vasospasm is refractory to typical medications. When this occurs, unconventional treatment modalities may be employed for symptomatic relief. We present a case of a 48-year-old-male with a history of inferior ST-elevation myocardial infarction (STEMI) status post percutaneous coronary intervention (PCI) with drug-eluting stent (DES) to the distal right coronary artery (RCA), who presented with recurrent angina. The pain was described as pressure-like, substernal, radiating to both arms, and similar to his previous STEMI presentation. On presentation to the emergency room, he had an elevated serum troponin with no electrocardiogram (EKG) changes. He was taken to the cath lab where it was found that he revealed severe focal stenosis just proximal to the previously placed stent. Immediately after guidewire passage into the RCA, acute vasospasm developed, resulting in diffuse, severe stenosis, extending over previously normal segments to the proximal RCA, resolving with intracoronary nicardipine and nitroglycerin, including the initial focal stenosis. The patient was diagnosed with VSA. Unfortunately, despite optimal medical therapy, he developed refractory VSA, requiring the use of unconventional treatment methods. Our patient presented with a lesser-known phenomenon called refractory VSA, where intermittent vasospasm continues despite being on a combination of two medications. Treatment for VSA is well-documented, however, little data is available for refractory VSA.

Human sperm do not bind to rat zonae pellucidae despite the presence of four homologous glycoproteins.

The specificity of sperm-egg recognition in mammals is mediated primarily by the zona pellucida surrounding ovulated eggs. Mouse sperm are quite promiscuous and bind to human eggs, but human spermatozoa will not bind to mouse eggs. The mouse zona pellucida contains three glycoproteins, ZP1, ZP2, and ZP3, which are conserved in rat and human. The recent observation that human zonae pellucidae contain a fourth protein raises the possibility that the presence of four zona proteins will support human sperm binding. Using mass spectrometry, four proteins that are similar in size and share 62-70% amino acid identity with human ZP1, ZP2, ZP3, and ZP4/ZPB were detected in rat zonae pellucidae. However, although mouse and rat spermatozoa bind to eggs from each rodent, human sperm bind to neither, and the presence of human follicular fluid did not alter the specificity of sperm binding. In addition, mutant mouse eggs lacking hybrid/complex N-glycans or deficient in Core 2 O-glycans were no more able to support human sperm binding than normal mouse eggs. These data suggest that the presence of four zona proteins are not sufficient to support human sperm binding to rodent eggs and that additional determinants must be responsible for taxon-specific fertilization among mammals.