Molecular aspects of the histamine H1 receptor

Leurs, R. [Promotor]Bakker, R.A. [Copromotor

Rapid Removal and Efficient Recovery of Tetracycline Antibiotics in Aqueous Solution Using Layered Double Hydroxide Components in an In Situ-Adsorption Process

This work demonstrates a simple approach for the efficient removal of tetracycline (TC) antibiotic from an aqueous solution. The in situ-adsorption removal method involved instant precipitation formation of mixed metal hydroxides (MMHs), which could immediately act as a sorbent for capturing TC from an aqueous solution, by employing layered double hydroxide (LDH) components including magnesium and aluminum ions in alkaline conditions. By using this approach, 100% removal of TC can be accomplished within 4 min under optimized conditions. The fast removal possibly resulted from an instantaneous adsorption of TC molecules onto the charged surface of MMHs via hydrogen bonding and electrostatically induced attraction. The results revealed that our removal technique was superior to the use of LDH as a sorbent in terms of both removal kinetics and efficiency. Moreover, the recovery of captured TC was tested under the influence of various common anions. It was found that 98% recovery could be simply achieved by using phosphate, possibly due to its highly charged density. Furthermore, this method was successful for efficient removal of TC in real environmental water samples

วิธีการทางคณิตศาสตร์สำหรับสมการชเรอดิงเงอร์และการหาเงื่อนไขของการเกิดค่าความถี่ควอซีนอร์มอลสำหรับพลังงานศักย์แบบต่าง ๆMathematical Method for Schrödinger Equation and Finding Condition of Quasi-normal Frequencies for Various Potentials

สมการชเรอดิงเงอร์นับว่ามีบทบาทเป็นอย่างมากในการศึกษาและทำความเข้าใจปรากฏการณ์ที่เกิดขึ้นในกลศาสตร์ควอนตัมเนื่องจากมีผลเฉลยเป็นฟังก์ชันคลื่น ซึ่งสามารถใช้ทำนายพฤติกรรรมต่าง ๆ ของคลื่นได้โดยจะมีค่าเปลี่ยนไปตามพลังงานศักย์ที่ใช้ โดยทั่วไปสมการชเรอดิงเงอร์สามารถแบ่งออกได้เป็น 2 ประเภท คือ สมการชเรอดิงเงอร์ที่ขึ้นกับเวลา และสมการชเรอดิงเงอร์ที่ไม่ขึ้นกับเวลา สำหรับในบทความนี้ได้สนใจศึกษาผลเฉลยของสมการชเรอดิงเงอร์ที่ไม่ขึ้นกับเวลาในหนึ่งมิติโดยวิธีการประมาณค่าแบบดับเบิลยูเคบี ซึ่งผลเฉลยดังกล่าวจะนำไปสู่การหาเงื่อนไขที่ทำให้เกิดค่าความถี่ควอซีนอร์มอลสำหรับพลังงานศักย์แบบต่าง ๆThe Schrödinger equation plays an important role in the study and understanding of various phenomena occurring in quantum mechanics. Since the solution of the equation is a wave function, it can be used to predict the behavior of matter fluctuating in a wavelike pattern according to changes in potential energy. In general, the Schrödinger equation can be divided into two types: the time-dependent and time-independent Schrödinger equations. In this paper, we are interested in studying the solution of the time-independent Schrödinger equation in one dimension using the WKB approximation method. These solutions will lead to the discovery of conditions that generate quasi-normal frequencies for different potential energies

Greybody factors for massive scalar field emitted from black holes in dRGT massive gravity

Abstract Greybody factors are transmission probabilities of the Hawking radiation, which are emitted from black holes and can be obtained from the gravitational potential of black holes. The de Rham, Gabadadze, and Tolly (dRGT) massive gravity is one of the gravity theories that modified general relativity. In this paper, we investigate the greybody factor from the massive scalar field in both the asymptotically dS and the AdS spacetime using the WKB and the rigorous bound methods. We found that the greybody factor depends on the shape of the potential as found in quantum mechanics. The higher the potential barrier, the lower the amount of the greybody factor. Interestingly, for the low multipole case, we found that there exists a critical mass which provides the maximum bound of the greybody factor. This is a crucial feature of the massive scalar field on the greybody factor from the black holes in both the asymptotically dS and the AdS spacetime

A New Approach for Removing Anionic Organic Dyes from Wastewater Based on Electrostatically Driven Assembly

A conceptually new approach for an efficient removal of anionic organic dyes from wastewater using layered double hydroxides (LDHs) through their formation is presented. Acid yellow 25 (AY25) was used as anionic organic dye model molecules. As a result of the electrostatic induction, the removal mechanism involved a concurrent incorporation of AY25 molecules into the interlayer of LDHs during their structural arrangement, where Mg²⁺ and Al³⁺ ions were utilized to construct the base of LDHs in an alkaline solution. It was found that the molar stoichiometry of all precursors was a key factor affecting the removal efficiency. Within 5 min removal time, this method still maintained high removal efficiency of over 97% and provided a removal capacity of ∼186 mg g^–1, comparable to that of other LDH-based methods. Also, almost complete dye recovery was simply achieved by anionic exchange with common anions (Cl^–, NO₃^–, and CO₃^2–). Additionally, the present technique is straightforward, cost-effective, and environmentally friendly since it avoids the synthesis step of sorbents, thus significantly saving time, chemicals, and energy. Hence, this strategy not only exhibits the alternative exploitation of LDHs, but also provides new insights into the removal of contaminants from wastewater

Oligomerization of recombinant and endogenously expressed human histamine H4 receptors

In this study, we report the homo- and hetero-oligomerization of the human histamine H4R by both biochemical (Western blot and immobilized metal affinity chromatography) and biophysical [bioluminescence resonance energy transfer and time-resolved fluorescence resonance energy transfer (tr-FRET)] techniques. The H4R receptor is the most recently discovered member of the histamine family of G-protein-coupled receptors. Using specific polyclonal antibodies raised against the C-terminal tail of the H4R, we demonstrate the presence of H4R oligomers in human embryonic kidney 293 and COS-7 cells heterologously overexpressing H4Rs and putative native H4R oligomers in human phytohaemagglutinin blasts endogenously expressing H4Rs. Moreover, we show that H4R homo-oligomers are formed constitutively, are formed at low receptor densities (300 fmol/mg of protein), and are present at the cell surface, as detected by tr-FRET. The formation of these oligomers is independent of N-glycosylation and is not modulated by H4R ligands, covering the full spectrum of agonists, neutral antagonists, and inverse agonists. Although we show H4R homo-oligomer formation at physiological expression levels, the detection of H1R-H4R hetero-oligomers was achieved only at higher H1R expression levels and are most likely not physiologically relevant

A structural insight into the reorientation of transmembrane domains 3 and 5 during family A GPCR activation

Rearrangement of transmembrane domains (TMs) 3 and 5 after agonist binding is necessary for stabilization of the active state of class A G protein-coupled receptors (GPCRs). Using sitedirected mutagenesis and functional assays, we provide the first evidence that the TAS(I/V) sequence motif at positions 3.37 to 3.40, highly conserved in aminergic receptors, plays a key role in the activation of the histamine