bluuebunny/crossref_metadata_2025_split huggingface dataset:
The physiological importance and therapeutic potential of nitric oxide in the tumour-associated vasculature
Authors: Hirst D G , Flitney F W 
Published: November 2023

Abstract
The relationship between malignant tumours and their vascular supply differs in many respects from that of most normal tissues. Tumour vasculature is characterized by rapid proliferation (1,2), increased permeability (3,4), and disorganized architecture (5-8), properties which are both a cause and a consequence of inadequate perfusion and oxygenation (9). We may summarize the condition of tumour vasculature as a system that is maximally stimulated, yet still unable to meet the metabolic demands of the tissue it supplies. The consequences of this for cancer therapy are profound (I 0,11 ). An inadequate vascular network leads to a heterogeneous blood supply and to areas within most tumours that are deprived of the limiting metabolic substrate, oxygen (12-14). This in turn creates regions with radiobiologically hypoxic cells which are both resistant to radiotherapy and quiescent. The lack of proliferative activity protects them from many chemotherapeutic drugs which are proliferation-dependent in their cytotoxic action. It should occasion no surprise then, that the influence of vasoactive agents on tumour blood flow has received considerable attention over the last 20 years (15,16) and this approach is still seen as a mechanism through which the action of anti-cancer agents could be enhanced. This review will focus on the importance of one highly topical vasoactive molecule, nitric oxide (NO). While the importance of this molecule in cancer therapy generally has been considered in a recent review (17) we will focus on its role in tumour-associated vasculature and evaluate its potential as a target for cancer therapy in this context.
Thymidine phosphorylase/ platelet-derived endothelial cell growth factor: an angiogenic enzyme
Authors: Moghaddam Amir , Chaudhuri Rangana , Bicknell Roy 
Published: November 2023

Abstract
Thymidine phosphorylase is an angiogenic enzyme which is overexpressed in many solid tumours. In contrast to other well characterized angiogenic molecules such as vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) it is not a mitogen for endothelial cells nor is it heparin binding. The fact that thymidine phosphorylase is an angiogenic molecule, an enzyme involved in nucleotide homeostasis and not a classic growth factor makes it a particularly intriguing molecule to study. It is now known that the product of thymidine/phosphorylase action on thymidine, 2-deoxyD-ribose, is angiogenic and it is release of this that mediates the angiogenic activity of the enzyme. This chapter reviews the studies that have led to the identification of thymidine phosphorylase as a potential regulator of both physiological (e.g. endometrial) as well as tumour angiogenesis.
Involvement of prostanoids in angiogenesis
Authors: Spisni Enzo , Tomasi Vittorio 
Published: November 2023

Abstract
Studies on angiogenesis began in the seventeenth century when Marcello Malpighi in Bologna described the development of the chick embryo. Figure 22.1 is an original drawing from Malpighi’s book De Formatione Pulli in Ovo, as reported by Adelmann (1). Leighton, and later Folkman and collaborators, have used the chick chorioallantoic membrane (CAM) as a powerful tool with which to study the regulation of angiogenesis in vivo. (see Chapter 2).
The Biology of the Deep Ocean
Authors: Herring Peter 
Published: November 2023

Abstract
The deep ocean environment is the most extensive on our planet. Its denizens are normally unseen but whenever they are exposed to view they are regarded as bizarre aliens from a different world. The Biology of the Deep Ocean takes a close look at this apparently hostile world and explains how its inhabitants are exquisitely adapted to survive and flourish within it. The book begins with an analysis of how conditions in the oceanic environment differ from those in the familiar terrestrial world and then describes the techniques (and ingenuity) required to reveal the populations inhabiting the colossal volume of the deep oceans. A section on primary production emphasizes how almost all deep-sea life depends ultimately on the phytoplankton at the surface and the export flux to deeper water. The ultimate beneficiaries of this export, the populations on the deep-sea floor, are then discussed, together with the unique features of life fuelled by chemosynthesis at hydrothermal vents and cold seeps. The horizontal and vertical distribution patterns of deep-sea animals, and their changes in time and space, are controlled by physical, biological and historical factors. The rapid reduction of biomass with depth puts a high priority on efficient prey capture and energy conservation. Chapters on energy efficiency, mechanoreception, chemoreception and vision reveal the extraordinary adaptations necessary for success. Accounts of the effector systems involved in colour, camouflage and bioluminescence heighten the concept of a different world. A chapter on animal life styles emphasizes the links between size, sex, and seasonality, visible in the contrasting benefits of gigantism, dwarf males and the ability to respond to a periodic influx of food from the surface. The final chapter and appendix deal with the unique and exciting variety of life in the deep ocean, formalized as biodiversity. Its different expression on the sea floor and in midwater invites both comparisons with the rain forest and concerns about its fragility, taking the reader back to the emphasis in the first chapter on how little we still know about this critical habitat. The Biology of the Deep Ocean complements the two companion volumes on the biology of littoral and estuarine habitats and is designed to be accessible to all marine scientists, student and professional.
Geographical distribution and ecology
Authors: Tinsley R C , Loumont C , Kobel H R 
Published: November 2023

Abstract
Extant Xenopus species principally show a parapatric distribution; many species occupy very large distinct regions of Africa in an exclusive manner, whilst others have limited ranges. Some recently described species have been identified in samples from restricted localities and their geographical ranges are generally ill defined. In contrast to the detailed laboratory studies based on other aspects of Xenopus biology, there have been few field investigations and most ecological information is based on inference. For several species, ecological preferences emerge from their geographical distribution: thus, X. tropicalis, epitropicalis and certain species of the fraseri group are more or less restricted to lowland rain forest, whereas X. muelleri is adapted to hot, dry lowland outside the zones of rain forest and wooded savanna. This ecological restriction is particularly well illustrated for the eastern population of muelleri whose range lies below 800 m and may be limited by competing species at higher altitudes, and whose southern extension ends at the 18 °C isotherm. While the mutual laevis-muelleri exclusion in south-eastern Africa could result from the temperature requirements of X. muelleri, X. laevis does not seem to be limited by a reciprocal temperature preference since it occupies niches in Namibia and Namaqualand at least as hot as X. muelleri inhabits in the east. The northernmost limit of laevis is at Jebel Marra, within the muelleri zone of the southern Sahara, where laevis may have been isolated after a previous pluvial period.
Reproductive capacity of experimental Xenopus gilli x X. I. laevis hybrids
Authors: Kobel Hans Rudolf 
Published: November 2023

Abstract
Hybridization between X. I. laevis and the rare X. gilli represents an additional threat to the latter species whose geographical range is restricted to a small coastal strip from the Cape Peninsula to Cape Agulhas, South Africa. Laboratory studies on the reproductive capacity of experimental hybrids between the two species revealed that male F1 hybrids are sterile because of failure of meiotic chromosome pairing and subsequent univalent meiosis. Female F1 hybrids produce two egg types: small eggs issue from normal oocytes and big eggs from polyploidized oocytes. While the former are aneuploid because of univalent meiosis and give lethal embryos, big endoreduplicated eggs contain complete chromosome sets of both parental species. After fertilization with spermatozoa of either species, they develop into triploid females that again may produce the two egg classes.
Sexual differentiation in Xenopus laevis
Authors: Kelley Darcy B 
Published: November 2023

Abstract
During primary sexual differentiation in Xenopus laevis, the initially ‘indifferent’ gonads develop as testes or ovaries. Males can be functionally sex-reversed by the administration of the ovarian steroid hormone oestradiol during the early stages of gonadal differentiation (tadpole stages 54 to 66). Females can be functionally sex-reversed by the implantation of a testis during this time; administration of the testicular steroid testosterone does not result in gonadal masculinization. The sexes of progeny from crosses of sex-reversed frogs suggest that males are the homogametic (ZZ) and females the heterogametic sex (ZW); individuals whose inferred genotype is WW are female.
The Biology of Streams and Rivers
Authors: Giller Paul S , Malmqvist Björn 
Published: November 2023

Abstract
Although they constitute less than 1% of the world's water, freshwaters play a vital role in life on Earth. Running water, or lotic, habitats comprise a tiny proportion of these freshwaters, yet they offer important resources and are rich and complex environments. This book provides an essential introduction to the biology and ecology of lotic habitats, and their constituent organisms. Rarely has the breadth and complexity of all aspects of the biology of streams and rivers been dealt with in a single volume. The aim of this book is to delve into the rich and growing literature, and to provide an up-to-date introduction to stream and river biology. It begins by outlining the factors that make running water habitats unique, and describing the many different water-course systems. The authors then outline the range of living organisms in lotic habitats, and the environmental adaptations they exhibit. They discuss population, community, and ecosystem patterns and processes, such as energy flow, nutrient cycling, migration, food webs, and community structure. Each chapter includes practical information on simple studies and experiments for students to try. The book finishes with a discussion of applied issues surrounding water use, pollution, species diversity, and conservation of this fascinating and immensely important habitat.
An overview of venomous snake evolution
Authors: Underwood Garth 
Published: November 2023

Abstract
Scolecophidians have serous as well as mucous supralabial glands, but do not otherwise foreshadow later developments. Remaining snakes are primarily of secretive or burrowing nocturnal habits with a simple duplex retina (with rods and small single cones), mucous labial glands and serous superior and inferior rictal glands, opening into the corner of the mouth. They have limited mobility of the jaws and use constriction to subdue large prey of small diameter. Phisalix reports superior rictal glands to be toxic; perhaps they have a defensive function. Amongst erycines, boines, pythonines, tropidophines and bolyerines the rictal glands regress; they are able to swallow bulky prey, subdued by constriction.
Reef Evolution
Authors: Wood Rachel 
Published: November 2023

Abstract
Reefs are an extraordinary natural phenomenon. Visible from outer space, coral reefs are the largest biologically constructed features known; in close proximity their spectacular beauty and abundance of life is dazzling. Reefs are estimated to occupy only a small percentage of the oceans, but their importance to the marine environment is many-faceted and global. Reefs create harbours and allow the development of shallow basins with associated mangrove or seargrass communities; they protect coastlines from erosion; reefs are involved in the regulation of atmospheric carbon, which in turn contributes to climate control; ancient reefs can provide extensive oil and gas reservoirs. From a biological standpoint, however, the great significance of reefs lies in their ability to generate and maintain a substantial proportion of tropical marine biodiversity. This text documents those biological innovations which have moulded the evolution of reef ecosystems and given rise to the highly complex communities found today. The appearance of clonality, the acquisition of photosymbiosis and the radiation of predator groups are all discussed in depth. Throughout the book, Rachel Wood uses data from the fossil record to document the evolutionary development of reef ecosystems. This interdisciplinary approach has the aim of providing an analytical text which will be of value not only to advanced undergraduates and postgraduate courses, but also to researchers in ancient reef ecology. Rachel Wood is Royal Society University Research Fellow, and Fellow, Gonville and Caius College, Cambridge.
Atoms in Molecules
Authors: Bader Richard F W 
Published: November 2023

Abstract
The molecular structure hypothesis - that a molecule is a collection of atoms linked by a network of bonds - was forged in the crucible of nineteenth-century experimental chemistry and has continued to serve as the principal means of ordering and classifying the observations of chemistry. There is a difficulty with the hypothesis, however, in that it is not related directly to the physics which governs the motions of the nuclei and electrons that make up the atoms and the bonds. It is the purpose of this important new book to show that a theory can be developed to underpin the molecular structure hypothesis - that the atoms in a molecule are real, with properties predicted and defined by the laws of quantum mechanics, and that the structure their presence imparts to a molecule is indeed a consequence of the underlying physics. As a result the classification based upon the concept of atoms in molecules is freed from its empirical constraints and the full predictive power of quantum mechanics. As a result the full predictive power of quantum mechanics can be incorporated into the resulting theory - a theory of atoms in molecules. The book is aimed at those scientists responsible for performing the experiments and collecting the observations on the properties of matter at the atomic level, in the belief that the transformation of qualitative concepts into a quantitative theory will serve to deepen our understanding of chemistry.
Chemical Models And The Laplacian Of The Charge Density
Authors: Bader Richard F W 
Published: November 2023

Abstract
The 1916 paper of Lewis, introducing the concept of the electron pair, is one of the most important papers to be published in chemistry in this century. It is a revelation to read this paper and realize the extent to which his ideas continue to dominate chemical thinking. One must marvel at the intuitive leap that was involved in advancing the notion of the importance of the electron pair, coming as it did before the development of quantum mechanics or the still later introduction of the concept of electron spin. Indeed the opening quotation from the paper by Lewis was penned in response to Bohr’s then recently advanced mechanical model of the atom. So strong was his conviction regarding the existence of a closely coupled pair of electrons (we would say a localized pair) as being necessary for the understanding of chemical bonding, he felt forced to postulate the failure of Coulomb’s law for small interelectronic separations, and to thus necessarily reject any model which made use of this law. It is clear from the quotation given at the beginning of Chapter 5 that Lewis later (1933) abandoned this extreme position.
Scientific work in the 1880s
Authors: Kipnis A Ya , Yavelov B E , Rowlinson J S 
Published: November 2023

Abstract
At the meetings of the Section of Sciences in October and November 1880 he set out a fruitful development in molecular physics called the principle (or law) of corresponding states [12aci]. Two substantial papers in Dutch were published the same year [12,15]. Roth worked quickly; abstracts appeared in the Beibliitter in January and April 1881, and complete and even extended translations were incorporated into the German version of Continuity. Roth, one of the most active contributors to the Beibliitter, was for many years almost a ‘personal abstractor’ of van der Waals’s work, and even drew atten tion to it in his abstracts of other papers in the field [3]. Van der Waals arrived at the principle of corresponding states by analysing the transition from gas to liquid represented by the loops in his isotherms, that is the curve Bcdefgh in Fig. 3.2. These loops are unobservable and the experimental points lie on the horizontal line CG. At what pressure must this line be drawn? In 1873 he had ‘not had the good fortune to solve this important problem.... I have not succeeded in finding, in any of the properties of the saturated vapour, a characteristic one that I could use to determine where this line must be drawn through the isotherm’ [le2, p. 232,233].
Inclusion of ions and neutral molecules in calixarenes
Authors: Andreetti Giovanni D , Ugozzoli Franco , Ungaro, Rocco , Pochini Andrea 
Published: November 2023

Abstract
The design and synthesis of molecular systems which perform chemical, physical, and biomimetic transformations with high efficiency and selectivity, and the understanding of the factors which determine the selective molecular recognition are two of the major aims of host-guest or supramolecular chemistry. In this novel multidisciplinary research area there is a continuous need for new building blocks, shaping units, or substructures which can be easily functionalized to build up more complex structures able to perform a particular transformation. Since the pioneering work of Gutsche and Muthukrishnan, Gutsche et al., and ourselves, which was mainly devoted to establishing the structures of the cyclic products formed by the base-catalyzed condensation of phenols and formaldehyde, the calixarenes (1)-(4) (see the preceeding chapter by Gutsche) have become rather popular among the chemical community.
Solid state Nmr studies of inclusion compounds
Authors: Ripmeeste J A , Ratcliffe C I 
Published: November 2023

Abstract
In the last review of solid state NMR as applied to clathrates,1 the emphasis was on clathrate hydrate work, with smaller contributions from studies on quinol and other clathrates. This time again clathrate hydrates are prominent, as these materials are perhaps the simplest and best understood of the clathrates. Since much work has been carried out on the channel inclusion compounds (urea, thiourea, cyclopho’ Sphazene, deoxycholic acid) these are also reviewed. For the sake of completeness, earlier work on these materials has also been summarized. Other host materials reviewed include cyclodextrins, tri-o-thymotide, and Dianin’s compound.
How do they do it?—Coping with oxygen
Authors: Milgrom Lionel R 
Published: November 2023

Abstract
Oxygen is a gas. Colourless and odourless, without it we suffocate. Yet when its partial reduction products, hydroxyl radicals and peroxy radicals, ovenvhelm our body’s defence systems, oxygen ultimately kills us. It is these partial reduction products that are the most likely cause of ageing.
On the use of the fast rotation function
Authors: Alzari P M , Navaza J 
Published: November 2023

Abstract
The widespread use of molecular replacement techniques in protein crystallography is a result of the significant number of known three-imensional structures now available in the Protein Data Bank. These techniques are used almost without exception whenever a known structure for a closely homologous molecule to the one under study is available. Positioning of a molecular model in the unit cell involves the determination of both orientation and translation parameters. As a general rule, the orientation is first determined using Patterson search methods. A relatively precise solution of this problem is crucial for the success of the subsequent translation search.
Density modification: theory and practice
Authors: Podjarny A D , Rees B 
Published: November 2023

Abstract
Real space phasing methods are aimed at improving the agreement of a density map with a set of physically meaningful constraints. Density maps must agree simultaneously with experimental data such as the observed amplitudes and the MIR phase distribution and with physical constraints based on a-priori knowledge of the characteristics of the density function. These physical constraints include positivity; boundedness; electron density histogram; high-resolution atomicity; uniformity of solvent regions; continuity of the bio-polymer chain; and known NCS of the density distribution. A starting map to be processed by real space methods, such as an MIR map, is usually obtained from, and thus will fully agree with, the experimental data. If the map also agrees with the set of physical constraints, there is no room for real space techniques, and map interpretation should be attempted. It is more often the case, however, that the map does not fully agree with all the physical constraints. In this case there is room to improve the agreement by real space techniques. To impose the physical constraints on an experimental map, a “Density Modification (DM)* iterative algorithm has been proposed [1,2]. It alternates real and reciprocal space operations, and the procedure is outlined in the flowchart shown in figure 1, with the following steps:
Tin-based antitumour drugs: past, present, and future
Authors: Gielen M , Meriem A , Boualam M , Delmotte A , Willem, R , Vos D de 
Published: November 2023

Abstract
The screening results obtained on the antitumour activity of several series of diorganotin compounds against L1210, P388, and P815 cancer cells in mice are reviewed, and perspectives for future research in this area delineated.
Solid/liquid equilibrium
Authors: Koningsveld R , Stockmayer W H , Nies E 
Published: November 2023

Abstract
Polymers with sufficiently regular chain structures can exist in the crystalline state, and departures from regularity reduce the stability (and hence the melting points) of polymer crystals. For example, ‘high-density’ polyethylene, produced with the aid of organometallic coordination (Ziegler type) catalysts, typically melts at around 135 °C, while the low-density polymer produced by high-pressure free-radical polymerization melts at ≤125 °C because that process introduces chain branching. Highly isotactic polystyrene has a crystalline melting point of about 230 °C, but ordinary atactic (actually slightly syndiotactic) polystyrene does not crystallize at all.
Introduction
Authors: Ernst Richard R , Bodenhausen Geoffrey , Wokaun Alexander 
Published: November 2023

Abstract
In the course of the last two decades, nuclear magnetic resonance (NMR) has gone through a profound renaissance. Slow-passage spectroscopy techniques have largely become obsolete, and more versatile pulse techniques have begun to dominate the NMR scene. The rediscovery of the time domain has revived interest and stimulated creativity for new methodological developments. A surprising diversity of novel approaches and ingenious procedures has been invented and has radically changed the scope of NMR spectroscopy.