bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular electro-optics
Authors: Porschke Dietmar 
Published: November 2023

Abstract
Molecular electro-optical techniques provide a high potential for the acquisition of a unique set of data on macromolecules in solution, including hydrodynamic, spectroscopic, and electrostatic parameters. The information obtained by molecular electro-optics is very useful for assigning macromolecular structures. A major advantage is the particular high sensitivity. Molecular electro-optics has been used for the characterization of many different types of macromolecules, including large numbers of proteins, and is also very useful for the analysis of protein-ligand interactions.
High-flux X-ray and neutron solution scattering
Authors: Perkins Stephen J 
Published: November 2023

Abstract
Solution scattering is a diffraction technique that is used to study the overall structure of biological macromolecules in random orientations (1-4). A sample is irradiated with a collimated, monochromatic beam of X-rays or neutrons, as the result of which a circularly-symmetric diffraction pattern is observed on a two-dimensional area detector at low scattering vectors Q, The intensities I(Q) are measured as a function of Q, where Q = 4 7T sin 0 / A (20 = scattering angle; A = wavelength). While X-rays are diffracted by electrons, and neutrons are diffracted by nuclei, the physical principles are the same in both types of scattering experiments. Classical solution scattering views structures at a low structural resolution of about 2-4 nm from data obtained in a Qrange of about 0.05-3 nm-1 (Figure 1). Analyses of I(Q) by Guinier plots lead to the overall molecular weight and the radius of gyration Re (and in certain cases those of the cross-section and the thickness). The Fourier transform of I(Q) gives the distance distribution function P(r), from which the maximum dimension of the macromolecule and its shape can be deduced. In recent years, a powerful method of constrained solution scattering has been developed (4), in which automated curve fit procedures based on known crystal structures are able to extract structural information to a precision of 0.5-1.0 nm, corresponding to medium resolution structures.
Protein-ligand interactions studied by Raman and resonance Raman spectroscopy
Authors: Withnall Robert 
Published: November 2023

Abstract
The occurrence of the phenomenon of inelastic light scattering (now often called ‘Raman light scattering’) was first demonstrated by C. V. Raman (1), who was awarded a Nobel prize in Physics in 1930 for his discovery.
The Raman light scattering process involves two photons, one of which is incident on the sample whilst the other is scattered from the sample. The scattered photons travel in all directions over the full solid angle of 41r steradians although, in the Raman experiment, it is common to detect either those which are back-scattered (back-scattering configuration) or those which are scattered at an angle of90° to the direction of propagation of the incident light (90° scattering configuration).
Nitroxide spin labels as paramagnetic probes
Authors: Middleton David A 
Published: November 2023

Abstract
This chapter describes how spin label electron paramagnetic resonance (EPR) spectroscopy can be used to examine aspects of molecular structure and dynamics, and changes therein, associated with the binding of ligands to receptors at their sites of action. The scope of the chapter is restricted to studies of proteins that function within cell membranes, where this approach is particularly relevant, although some of the experimental methods can be adapted to accommodate studies on soluble proteins.
Chromosomal DNA replication in yeast: enzymes and mechanisms
Authors: Macneill Stuart A , Burgers Peter M J 
Published: November 2023

Abstract
Chromosomal DNA replication in eukaryotic cells is a remarkable process requiring the complex interplay of a variety of distinct essential factors in a spatially and temporally coordinated manner. Each replication fork supports a large multiprotein complex containing as many as 30 to 40 proteins, the vast majority of which are essential for the successful duplication of the genome. In the yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe, the molecular basis of the replication process has been studied in great detail. Indeed much of our current understanding of replication in higher eukaryotes is founded on work performed on these two distantly related ascomycetes. Each has a genome size of approximately 15 Mb and a doubling time in the range 110-240 min depending on strain characteristics and the precise growth conditions employed. S phase occupies approximately 10-15% of the cell cycle, or 15-20 min at optimal growth rates.
Mechanisms of nuclear division
Authors: Masuda Hirohisa , Hiraoka Yasushi 
Published: November 2023

Abstract
Mitotic nuclear division is the process that ensures proper segregation of duplicated copies of the genome at cell division. The orderly segregation of genetic information depends on its reorganization into condensed chromosomes, and on the assembly and functioning of the mitotic spindle. The mitotic spindle is the machinery that segregates sister chromatids into the two daughter nuclei at mitosis. These events are precisely regulated to produce genetically identical daughter cells.
In contrast, meiotic nuclear division is the process that generates genetic diversity in the offspring. Recombination of genetic information from cells with opposite mating types occurs at meiotic prophase. Meiosis encompasses two successive nuclear divisions: the first division involves cohesion of sister chromatids and disjunction of homologous chromosomes, while the second division disjoins sister chromatids in a process similar to mitotic di vision.
In this chapter we first describe mechanisms of mitotic nuclear division with an emphasis on the mechanistic aspect of the mitotic spindle and chromosomes; next, we describe mechanisms of meiotic nuclear division with a particular emphasis on chromosome organization specific to meiosis.
Radioisotope Use
Authors: Prime David , Frith Barry 
Published: November 2023

Abstract
The subject of this chapter is the safe use of radioisotopes in biological tracer work. The emphasis of the treatment will be on the practical aspects but a certain amount of a more fundamental nature will be included where this is necessary to clarify explanations and terminology. Since biological tracers are used in a wide variety of ways, it is only intended to discuss this topic in general terms, paying particular attention to the most commonly used radioisotopes.
The Scintillation Counter
Authors: Dodson Charles L 
Published: November 2023

Abstract
A radioactive atom or molecule emits small particles or photons or both. Monitoring radioactivity depends upon the detection of such emissions, counting either the number of particles or the number of photons. No method has been discovered to monitor radioactively emitted particles directly. Rather, we monitor the emitted photons or the effects produced by the particles interacting with selected matter. An instrument to measure radioactivity requires a sample, means of detection and means of recording. In experiments conducted early in the nineteenth century, radioactivity was monitored by dark-adapted human eyes counting scintillations produced by solid detectors and lead sulfide, and recorded by human hand. This chapter describes machines that produce the same end result by automation.
Monitoring the turnover kinetics of G protein-coupled receptors
Authors: Edwardson J Michael 
Published: November 2023

Abstract
G protein-coupled receptors are found predominantly at the plasma membrane in unstimulated cells (1). Following agonist stimulation, the receptors are usually efficiently endocytosed and delivered to intracellular compartments, from where they may be either recycled to the plasma membrane or transported to lysosomes for degradation. This intracellular transport is known to play an important role in the regulation of receptor function. Consequently, a complete characterization of the processes of receptor endocytosis and recycling is crucial to our understanding of cellular responses to agonists. The quantitation of receptor trafficking is best achieved by the use of radioligand binding. In intact cells, a non-polar, membrane-permeant radioligand will detect the total population of receptors, whereas a polar, membrane-impermeant radioligand will detect only receptors present at the cell surface. The transport of receptors into and out of the plasma membrane can therefore be measured through changes in the binding of a membrane-impermeant radioligand. In response to agonist stimulation, the binding of such a radioligand typically falls rapidly, with a half-time of a few minutes, reaching a value of 40-60% of the binding to unstimulated cells after about 30 minutes (2, 3). During this 30 minute period there is no significant reduction in the total number ofreceptors, measured through the binding of a membrane-permeant radioligand (2, 3). If the agonist is removed after a short time, the density of receptors at the surface is restored almost to the original value, by receptor recycling (2, 3). In fact, the redistribution of receptors in response to agonist stimulation, usually termed internalization, represents a ‘snap-shot’ of a new steady-state, in which at any instant there are fewer receptors at the cell surface and more in internal compartments.
Real time receptor function in vitro: microphysiometry and the fluorometric imaging plate reader (FLIPR)
Authors: Wood Martyn , Smart Darren 
Published: November 2023

Abstract
The recent application of molecular biological techniques to the cloning of receptors has greatly increased our understanding of their function and regulation. This has enabled the study of the direct interaction of the ligand with a single receptor essentially free of many of the complications experienced with in vitro studies in native receptors, although the use of recombinant expression systems has introduced new problems such as overexpression and lack of, or incorrect, coupling mechanisms. However, for receptors with 7-transmembrane domains, the use of heterologous expression systems has resulted in a limited ability to study receptor function in real time. Instead of measuring contractile or secretory responses directly, receptor function is studied using biochemical techniques such as changes in the concentration of cAMP, changes in the activity of adenylyl cyclase, or accumulation of inositol phosphates. However, these changes are not measured in real time but use ‘before’ and ‘after’ or ‘end-point’ measurements. Here, we describe the use of two techniques which enable the real time assessment of receptor function using cloned receptors expressed in cell lines, with special reference to the family of 7-transmembrane spanning receptors.
In vivo gene transfer of antisense to receptors: methods for antisense delivery with adeno-associated virus
Authors: Phillips M Ian , Qian Keping , Mohuczy Dagmara 
Published: November 2023

Abstract
Ligand receptor binding is a critically important step in the process of many diseases. Over-production of a ligand can be as pathogenic as under-production or lack of a ligand and up-regulation of receptors can produce the same defect as over-production of a ligand. Likewise, down-regulation of receptors can result in the same effects as under-production of the ligand. For example, drugs used to treat hypertension, a chronic disease affecting millions, have included p-adrenergic receptor blockers, ot-adrenergic receptor blockers and, more recently, angiotensin type 1 receptor (ATrR) blockers and Ca2+ channel blockers. All are aimed at reducing the ligand receptor binding interaction by drug receptor antagonism.
Factors Associated With Sinoatrial Reinnervation After Heart Transplantation
Authors: Christensen Anders H. , Wyller Vegard B.B. , Nygaard Sissel , Rolid Katrine , Nytrøen Kari , Gullestad Lars , Fiane Arnt , Thaulow Erik , Saul J. Philip , Døhlen Gaute 
Published: November 2023

Background.
Factors associated with sympathetic and parasympathetic sinoatrial reinnervation after heart transplantation (HTx) are inadequately studied.

Methods.
Fifty transplant recipients were examined at 7 to 12 wk (index visit), 6, 12, 24, and 36 mo after HTx. Supine rest heart rate variability in the low-frequency (LF) domain (sympathetic and parasympathetic sinoatrial reinnervation) and the high-frequency (HF) domain (parasympathetic sinoatrial reinnervation) were measured repeatedly and related to selected recipient, donor, and perisurgical characteristics. We primarily aimed to identify index visit factors that affect the sinoatrial reinnervation process. Secondarily, we examined overall associations between indices of reinnervation and repeatedly measured recipient characteristics to generate new hypotheses regarding the consequences of reinnervation.

Results.
LF and HF variability increased time dependently. In multivariate modeling, a pretransplant diagnosis of nonischemic cardiomyopathy (P = 0.038) and higher index visit handgrip strength (P = 0.028) predicted improved LF variability. Recipient age, early episodes of rejection, and duration of extracorporeal circulation were not associated with indices of reinnervation. Study average handgrip strength was positively associated with LF and HF variability (respectively, P = 0.005 and P = 0.029), whereas study average C-reactive protein was negatively associated (respectively, P = 0.015 and P = 0.008).

Conclusions.
Indices of both sympathetic and parasympathetic sinoatrial reinnervation increased with time after HTx. A pretransplant diagnosis of nonischemic cardiomyopathy and higher index visit handgrip strength predicted higher indices of mainly sympathetic reinnervation, whereas age, rejection episodes, and duration of extracorporeal circulation had no association. HTx recipients with higher indices of reinnervation had higher average handgrip strength, suggesting a link between reinnervation and improved frailty. The more reinnervated participants had lower average C-reactive protein, suggesting an inhibitory effect of reinnervation on inflammation, possibly through enhanced function of the inflammatory reflex. These potential effects of reinnervation may affect long-term morbidity in HTx patients and should be scrutinized in future research.
Motivational drivers of heavy work investment: intercultural comparison between USA and Egypt
Authors: Garas Lydia , Aziz Shahnaz , Wuensch Karl , Waterwall Brian 
Published: November 2023

Purpose The purpose is to identify the underlying motives of heavy work investment (HWI) types (i.e. workaholism and work engagement) based on self-determination theory, while controlling for job demands and resources. The role of four cultural differences (i.e. individualism, power distance, uncertainty avoidance and masculinity) in moderating the motivational correlated relationships is also explored using data retrieved from two distinct cultures (i.e. the USA and Egypt).Design/methodology/approach Full-time employees (N = 595) in the USA and Egypt were surveyed. Multiple regression analyses were used to test the associations between the two HWI types and four types of motivation (i.e. intrinsic, extrinsic, introjected and identified motivations). Furthermore, moderation analyses were conducted to explore potential effects of four cultural dimensions (i.e. individualism, power distance, uncertainty avoidance and masculinity) on the motivationalcorrelated relationships.Findings Workaholism positively relates to the controlled types of motivation (i.e. extrinsic and introjected regulation), while work engagement positively relates to the autonomous ones (i.e. intrinsic and identified regulation) and negatively associates with extrinsic motivation. Moreover, cultural masculinity moderated the relationship between work engagement and extrinsic motivation, as well as the association between workaholism and extrinsic motivation.Practical implications A clear differentiation of motivation behind both types of HWI is required by occupational health practitioners to design interventions that stimulate employee engagement rather than fuel workaholism. Multinational organizations could also benefit from understanding the interaction between cultural dimensions, motives and HWI, thereby planning more effective work engagement strategies among different cultures.Originality/value This is the first study to investigate the motivational correlates of HWI types across two contrasting cultures.
Mitochondrial dysfunction is associated with hypertrophic cardiomyopathy in Pompe disease‐specific induced pluripotent stem cell‐derived cardiomyocytes
Authors: Huang Wenjun , Zhou Rui , Jiang Congshan , Wang Jie , Zhou Yafei , Xu Xiaoyan , Wang Tao , Li Anmao , Zhang Yanmin 
Published: November 2023

AbstractPompe disease (PD) is a rare autosomal recessive disorder that presents with progressive hypertrophic cardiomyopathy. However, the detailed mechanism remains clarified. Herein, PD patient‐specific induced pluripotent stem cells were differentiated into cardiomyocytes (PD‐iCMs) that exhibited cardiomyopathic features of PD, including decreased acid alpha‐glucosidase activity, lysosomal glycogen accumulation and hypertrophy. The defective mitochondria were involved in the cardiac pathology as shown by the significantly decreased number of mitochondria and impaired respiratory function and ATP production in PD‐iCMs, which was partially due to elevated levels of intracellular reactive oxygen species produced from depolarized mitochondria. Further analysis showed that impaired fusion and autophagy of mitochondria and declined expression of mitochondrial complexes underlies the mechanism of dysfunctional mitochondria. This was alleviated by supplementation with recombinant human acid alpha‐glucosidase that improved the mitochondrial function and concomitantly mitigated the cardiac pathology. Therefore, this study suggests that defective mitochondria underlie the pathogenesis of cardiomyopathy in patients with PD.
Sirtuin 2 promotes human cytomegalovirus replication by regulating cell cycle progression
Authors: Betsinger Cora N. , Justice Joshua L. , Tyl Matthew D. , Edgar Julia E. , Budayeva Hanna G. , Abu Yaa F. , Cristea Ileana M. 
Published: November 2023

ABSTRACT
The ability to modulate host cell cycle progression is a requirement of many human viruses in order to facilitate their replication and propagation. Nuclear-replicating DNA viruses frequently stall the host cell cycle in G1 to avoid competition with host DNA replication. Among these viruses is human cytomegalovirus (HCMV), a prevalent beta-herpesvirus. Here, we discover a pro-viral mechanism that employs the deacetylase activity of the human enzyme sirtuin 2 (SIRT2) for HCMV-mediated cell cycle dysregulation. First, we show that the SIRT2 deacetylase activity supports an early stage of HCMV replication. Focusing on these early infection time points, we next define temporal SIRT2 protein interactions and deacetylation substrates by using mass spectrometry-based interactome and acetylome analyses. We find that SIRT2 interacts with and modulates the acetylation level of cell cycle proteins during infection, including the cyclin-dependent kinase 2 (CDK2). Using flow cytometry, cell sorting, and functional assays, we demonstrate that SIRT2 regulates CDK2 K6 acetylation and the G1- to S-phase transition in a manner that supports HCMV replication. Altogether, our findings expand the understanding of mechanisms underlying HCMV-induced cell cycle dysregulation and point toward regulatory feedback between SIRT2 and CDK2 that can have implications in other viral infections and human diseases.

IMPORTANCE
This study expands the growing understanding that protein acetylation is a highly regulated molecular toggle of protein function in both host anti-viral defense and viral replication. We describe a pro-viral role for the human enzyme SIRT2, showing that its deacetylase activity supports HCMV replication. By integrating quantitative proteomics, flow cytometry cell cycle assays, microscopy, and functional virology assays, we investigate the temporality of SIRT2 functions and substrates. We identify a pro-viral role for the SIRT2 deacetylase activity via regulation of CDK2 K6 acetylation and the G1-S cell cycle transition. These findings highlight a link between viral infection, protein acetylation, and cell cycle progression.
A narrative review of challenges related to healthcare worker rights, roles and responsibilities in the provision of sexual and reproductive services in health facilities
Authors: Schaaf Marta , Lavelanet Antonella , Codjia Laurence , Nihlén Åsa , Rehnstrom Loi Ulrika 
Published: November 2023

IntroductionThis paper identifies and summarises tensions and challenges related to healthcare worker rights and responsibilities and describes how they affect healthcare worker roles in the provision of sexual and reproductive health (SRH) care in health facilities.MethodThe review was undertaken in a two-phase process, namely: (1) development of a list of core constructs and concepts relating to healthcare worker rights, roles and responsibilities to guide the review and (2) literature review.ResultA total of 110 papers addressing a variety of SRH areas and geographical locations met our inclusion criteria. These papers addressed challenges to healthcare worker rights, roles and responsibilities, including conflicting laws, policies and guidelines; pressure to achieve coverage and quality; violations of the rights and professionalism of healthcare workers, undercutting their ability and motivation to fulfil their responsibilities; inadequate stewardship of the private sector; competing paradigms for decision-making—such as religious beliefs—that are inconsistent with professional responsibilities; donor conditionalities and fragmentation; and, the persistence of embedded practical norms that are at odds with healthcare worker rights and responsibilities. The tensions lead to a host of undesirable outcomes, ranging from professional frustration to the provision of a narrower range of services or of poor-quality services.ConclusionSocial mores relating to gender and sexuality and other contested domains that relate to social norms, provider religious identity and other deeply held beliefs complicate the terrain for SRH in particular. Despite the particularities of SRH, a whole of systems response may be best suited to address embedded challenges.