Tea and Its Consumption: Benefits and Risks

The recent convention of introducing phytochemicals to support the immune system or combat diseases is a centuries’ old tradition. Nutritional support is an emerging advancement in the domain of diet-based therapies; tea and its constituents are one of the significant components of these strategies to maintain the health and reduce the risk of various malignancies. Tea is the most frequently consumed beverage worldwide, besides water. All the three most popular types of tea, green (unfermented), black (fully fermented), and oolong (semifermented), are manufactured from the leaves of the plant Camellia sinensis. Tea possesses significant antioxidative, anti-inflammatory, antimicrobial, anticarcinogenic, antihypertensive, neuroprotective, cholesterol-lowering, and thermogenic properties. Several research investigations, epidemiological studies, and meta-analyses suggest that tea and its bioactive polyphenolic constituents have numerous beneficial effects on health, including the prevention of many diseases, such as cancer, diabetes, arthritis, cardiovascular disease (CVD), stroke, genital warts, and obesity. Controversies regarding beneficialts and risks of tea consumption still exist but the limitless health-promoting benefits of tea outclass its few reported toxic effects. However, with significant rise in the scientific investigation of role of tea in human life, this review is intended to highlight the beneficial effects and risks associated with tea consumption.     

Proposal and evaluation of a new norm index-based QSAR model to predict pEC50 and pCC50 activities of HEPT derivatives☆

The search and development of anti-HIV drugs is currently one of the most urgent tasks of pharmacological studies.In this work,a quantitative structure–activity relationship(QSAR) model based on some new norm indexes,was obtained to a series of more than 150 HEPT derivatives(1-[(2-hydroxyethoxy)methyl]-6-(phenylthio)thymine) to find their pEC_(50)(the required effective concentration to achieve 50% protection of MT-4 cells against the cytopathic effect of virus) and pCC_(50)(the required cytotoxic concentration to reduce visibility of 50% mock infected cell) activities.The model efficiencies were then validated using the leave-one-out cross validation(LOO-CV) and yrandomization test.Results indicated that this new model was efficient and could provide satisfactory results for prediction of pEC_(50) and pCC_(50) with the higher R_(train)~2 and the higher R_(test)~2.By using the leverage approach,the applicability domain of this model was further investigated and no response outlier was detected for HEPT derivatives involved in this work.Comparison results with reference methods demonstrated that this new method could result in significant improvements for predicting pEC_(50) and pCC_(50) of anti-HIV HEPT derivatives.Moreover,results shown in this present study suggested that these two absolutely different activities pEC_(50) and pCC_(50) of anti-HIV HEPT derivatives could be predicted well with a totally similar QSAR model,which indicated that this model might have the potential to be further utilized for other biological activities of HEPT derivatives.     

Identification of B-Cell Epitopes for Eliciting Neutralizing Antibodies against the SARS-CoV-2 Spike Protein through Bioinformatics and Monoclonal Antibody Targeting

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a global public health crisis. Effective COVID-19 vaccines developed by Pfizer-BioNTech, Moderna, and Astra Zeneca have made significant impacts in controlling the COVID-19 burden, especially in reducing the transmission of SARS-CoV-2 and hospitalization incidences. In view of the emergence of new SARS-CoV-2 variants, vaccines developed against the Wuhan strain were less effective against the variants. Neutralizing antibodies produced by B cells are a critical component of adaptive immunity, particularly in neutralizing viruses by blocking virus attachment and entry into cells. Therefore, the identification of protective linear B-cell epitopes can guide epitope-based peptide designs. This study reviews the identification of SARS-CoV-2 B-cell epitopes within the spike, membrane and nucleocapsid proteins that can be incorporated as potent B-cell epitopes into peptide vaccine constructs. The bioinformatic approach offers a new in silico strategy for the mapping and identification of potential B-cell epitopes and, upon in vivo validation, would be useful for the rapid development of effective multi-epitope-based vaccines. Potent B-cell epitopes were identified from the analysis of three-dimensional structures of monoclonal antibodies in a complex with SARS-CoV-2 from literature mining. This review provides significant insights into the elicitation of potential neutralizing antibodies by potent B-cell epitopes, which could advance the development of multi-epitope peptide vaccines against SARS-CoV-2.     

Neurodynamics for auditory stream segregation: tracking sounds in the mustached bat's natural environment

During navigation and the search phase of foraging, mustached bats emit approximately 25 ms long echolocation pulses (at 10-40 Hz) that contain multiple harmonics of a constant frequency (CF) component followed by a short (3 ms) downward frequency modulation. In the context of auditory stream segregation, therefore, bats may either perceive a coherent pulse-echo sequence (PEPE...), or segregated pulse and echo streams (P-P-P... and E-E-E...). To identify the neural mechanisms for stream segregation in bats, we developed a simple yet realistic neural network model with seven layers and 420 nodes. Our model required recurrent and lateral inhibition to enable output nodes in the network to 'latch-on' to a single tone (corresponding to a CF component in either the pulse or echo), i.e., exhibit differential suppression by the alternating two tones presented at a high rate (> 10 Hz). To test the applicability of our model to echolocation, we obtained neurophysiological data from the primary auditory cortex of awake mustached bats. Event-related potentials reliably reproduced the latching behaviour observed at output nodes in the network. Pulse as well as nontarget (clutter) echo CFs facilitated this latching. Individual single unit responses were erratic, but when summed over several recording sites, they also exhibited reliable latching behaviour even at 40 Hz. On the basis of these findings, we propose that a neural correlate of auditory stream segregation is present within localized synaptic activity in the mustached bat's auditory cortex and this mechanism may enhance the perception of echolocation sounds in the natural environment.     

Acoustic diffraction by a rigid annular disk

Summary The subject of this paper is the problem of acoustic diffraction by a perfectly rigid annular disk. The method of solution rests on formulating the problem in terms of an integral equation which embodies the steady state wave equation as well as the boundary conditions. This Fredholm integral equation of the first kind is converted into four simultaneous integral equations of the second kind by using Williams' integral equation technique. These four integral equations are subsequently solved by the standard iterative procedure when the frequency of the incident wave is low and the inner radius of the annulus is small.     

An overview of the Department of Energy's CarbonSAFE Initiative: Moving CCUS toward commercialization

The U.S. Department of Energy (DOE) Office of Fossil Energy (FE) National Energy Technology Laboratory (NETL) Carbon Storage Program helps develop technologies that safely and permanently store carbon dioxide (CO₂) without adversely impacting natural resources or hindering economic growth. Since 1997, the program has significantly advanced carbon capture, utilization, and storage (CCUS) science and technology, with more than 10.5 million metric tons (MMT) of CO₂ safely stored. However, key gaps in experience and knowledge remain (e.g., the technology, expertise, and processes needed to safely characterize and monitor 50+ MMT-scale geologic CO₂ storage sites). DOE's Carbon Storage Assurance Facility Enterprise (CarbonSAFE) Initiative (launched in FY16) is beginning to address this gap. The CarbonSAFE Initiative currently consists of 13 projects in Phase I: Integrated Carbon Capture and Storage (CCS) Pre-Feasibility and six projects in Phase II: Storage Complex Feasibility. This article includes the latest updates from the CarbonSAFE Initiative.     

Atrial natriuretic peptide inhibits evoked catecholamine release by altering sensitivity to calcium

Natriuretic peptides are cyclized peptides produced by cardiovascular and neural tissues. These peptides inhibit various secretory responses such as the release of renin, aldosterone and autonomic neurotransmitters. This report tests the hypothesis that atrial natriuretic peptide reduces dopamine efflux from an adrenergic cell line, rat pheochromocytoma cells, by suppressing intracellular calcium concentrations. The L-type calcium channel inhibitor, nifedipine, markedly suppressed dopamine release from depolarized PC12 cells, suggesting that calcium entering through this channel was the predominant stimulus for dopamine efflux. Atrial natriuretic peptide maximally reduced depolarization-evoked dopamine release 20 +/- 3% at a concentration of 100 nM and this effect was abolished by nifedipine, but not by pretreatment with the N-type calcium channel inhibitor, omega-conotoxin, or an inhibitor of calcium-induced calcium release, ryanodine. In cells loaded with Fura-2, atrial natriuretic peptide both augmented depolarization-induced increases of intracellular free calcium concentrations and accelerated the depolarization-induced quenching of the Fura-2 signal by manganese, findings consistent with enhanced conductivity of calcium channels. Dopamine efflux induced by either the calcium ionophore, A23187, or staphylococcal alpha toxin was attenuated by atrial natriuretic peptide. Additionally, a natriuretic peptide interacting solely with the natriuretic peptide C receptor in these cells, C-type natriuretic peptide, also suppressed calcium-induced dopamine efflux in permeabilized cells. These data are consistent with natriuretic peptides attenuating catecholamine exocytosis in response to calcium but inconsistent with the neuromodulatory effect resulting from a reduction in intracellular calcium concentrations within pheochromocytoma cells.     

Cobalt substituted ZnO thin films: a potential candidate for spintronics

Cobalt doped zinc oxide thin films have been deposited using spray pyrolysis method. These single phasic films exhibited [100] preferential texture and small decrease in the lattice parameter on cobalt substitution. The films having different Co concentration have almost similar surface morphology and microstructure. These Zn_1?x Co _x O (x ≤ 0.10) thin films distinctly showed ferromagnetic character at room temperature. The optical transmission measurements of these films clearly proved that in these films Co substitutes for Zn²⁺ and exists in +2 state. Based on the optical, structural and magnetic measurements, the possibility of occurrence of ferromagnetic ordering due to cobalt clustering is ruled out in these spray-pyrolyzed films. A correlation of the observed ferromagnetic behavior in these Zn_1?x Co _x O films with structural change resulting from the addition of Co is presented in this paper.