bluuebunny/crossref_metadata_2025_split huggingface dataset:
Control of Breathing During Exercise
Authors: Forster Hubert V. , Haouzi Philippe , Dempsey Jerome A. 
Published: January 2012

AbstractDuring exercise by healthy mammals, alveolar ventilation and alveolar‐capillary diffusion increase in proportion to the increase in metabolic rate to prevent PaCO2from increasing and Pao2from decreasing. There is no known mechanism capable of directly sensing the rate of gas exchange in the muscles or the lungs; thus, for over a century there has been intense interest in elucidating how respiratory neurons adjust their output to variables which can not be directly monitored. Several hypotheses have been tested and supportive data were obtained, but for each hypothesis, there are contradictory data or reasons to question the validity of each hypothesis. Herein, we report a critique of the major hypotheses which has led to the following conclusions. First, a single stimulus or combination of stimuli that convincingly and entirely explains the hyperpnea has not been identified. Second, the coupling of the hyperpnea to metabolic rate is not causal but is due to of these variables each resulting from a common factor which link the circulatory and ventilatory responses to exercise. Third, stimuli postulated to act at pulmonary or cardiac receptors or carotid and intracranial chemoreceptors are not primary mediators of the hyperpnea. Fourth, stimuli originating in exercising limbs and conveyed to the brain by spinal afferents contribute to the exercise hyperpnea. Fifth, the hyperventilation during heavy exercise is not primarily due to lactacidosis stimulation of carotid chemoreceptors. Finally, since volitional exercise requires activation of the CNS, neural feed‐forward (central command) mediation of the exercise hyperpnea seems intuitive and is supported by data from several studies. However, there is no compelling evidence to accept this concept as an indisputable fact. © 2012 American Physiological Society.Compr Physiol2:743‐777, 2012.
Peripheral Circulation
Authors: Laughlin M. Harold , Davis Michael J. , Secher Niels H. , van Lieshout Johannes J. , Arce‐Esquivel Arturo A. , Simmons Grant H. , Bender Shawn B. , Padilla Jaume , Bache Robert J. , Merkus Daphne , Duncker Dirk J. 
Published: January 2012

AbstractBlood flow (BF) increases with increasing exercise intensity in skeletal, respiratory, and cardiac muscle. In humans during maximal exercise intensities, 85% to 90% of total cardiac output is distributed to skeletal and cardiac muscle. During exercise BF increases modestly and heterogeneously to brain and decreases in gastrointestinal, reproductive, and renal tissues and shows little to no change in skin. If the duration of exercise is sufficient to increase body/core temperature, skin BF is also increased in humans. Because blood pressure changes little during exercise, changes in distribution of BF with incremental exercise result from changes in vascular conductance. These changes in distribution of BF throughout the body contribute to decreases in mixed venous oxygen content, serve to supply adequate oxygen to the active skeletal muscles, and support metabolism of other tissues while maintaining homeostasis. This review discusses the response of the peripheral circulation of humans to acute and chronic dynamic exercise and mechanisms responsible for these responses. This is accomplished in the context of leading the reader on a tour through the peripheral circulation during dynamic exercise. During this tour, we consider what is known about how each vascular bed controls BF during exercise and how these control mechanisms are modified by chronic physical activity/exercise training. The tour ends by comparing responses of the systemic circulation to those of the pulmonary circulation relative to the effects of exercise on the regional distribution of BF and mechanisms responsible for control of resistance/conductance in the systemic and pulmonary circulations. © 2012 American Physiological Society.Compr Physiol2:321‐447, 2012.
Structure and Composition of Pulmonary Arteries, Capillaries, and Veins
Authors: Townsley Mary I. 
Published: January 2012

AbstractThe pulmonary vasculature comprises three anatomic compartments connected in series: the arterial tree, an extensive capillary bed, and the venular tree. Although, in general, this vasculature is thin‐walled, structure is nonetheless complex. Contributions to structure (and thus potentially to function) from cells other than endothelial and smooth muscle cells as well as those from the extracellular matrix should be considered. This review is multifaceted, bringing together information regarding (i) classification of pulmonary vessels, (ii) branching geometry in the pulmonary vascular tree, (iii) a quantitative view of structure based on morphometry of the vascular wall, (iv) the relationship of nerves, a variety of interstitial cells, matrix proteins, and striated myocytes to smooth muscle and endothelium in the vascular wall, (v) heterogeneity within cell populations and between vascular compartments, (vi) homo‐ and heterotypic cell‐cell junctional complexes, and (vii) the relation of the pulmonary vasculature to that of airways. These issues for pulmonary vascular structure are compared, when data is available, across species from human to mouse and shrew. Data from studies utilizing vascular casting, light and electron microscopy, as well as models developed from those data, are discussed. Finally, the need for rigorous quantitative approaches to study of vascular structure in lung is highlighted. © 2012 American Physiological Society.Compr Physiol2:675‐709, 2012.
Central Chemoreceptors: Locations and Functions
Authors: Nattie Eugene , Li Aihua 
Published: January 2012

AbstractCentral chemoreception traditionally refers to a change in ventilation attributable to changes in CO2/H+detected within the brain. Interest in central chemoreception has grown substantially since the previous Handbook of Physiology published in 1986. Initially, central chemoreception was localized to areas on the ventral medullary surface, a hypothesis complemented by the recent identification of neurons with specific phenotypes near one of these areas as putative chemoreceptor cells. However, there is substantial evidence that many sites participate in central chemoreception some located at a distance from the ventral medulla. Functionally, central chemoreception, via the sensing of brain interstitial fluid H+, serves to detect and integrate information on (i) alveolar ventilation (arterial PCO2), (ii) brain blood flow and metabolism, and (iii) acid‐base balance, and, in response, can affect breathing, airway resistance, blood pressure (sympathetic tone), and arousal. In addition, central chemoreception provides a tonic “drive” (source of excitation) at the normal, baseline PCO2level that maintains a degree of functional connectivity among brainstem respiratory neurons necessary to produce eupneic breathing. Central chemoreception responds to small variations in PCO2to regulate normal gas exchange and to large changes in PCO2to minimize acid‐base changes. Central chemoreceptor sites vary in function with sex and with development. From an evolutionary perspective, central chemoreception grew out of the demands posed by air versus water breathing, homeothermy, sleep, optimization of the work of breathing with the “ideal” arterial PCO2, and the maintenance of the appropriate pH at 37°C for optimal protein structure and function. © 2012 American Physiological Society.Compr Physiol2:221‐254, 2012.
Mechanobiology in Lung Epithelial Cells: Measurements, Perturbations, and Responses
Authors: Waters Christopher M. , Roan Esra , Navajas Daniel 
Published: January 2012

AbstractEpithelial cells of the lung are located at the interface between the environment and the organism and serve many important functions including barrier protection, fluid balance, clearance of particulate, initiation of immune responses, mucus and surfactant production, and repair following injury. Because of the complex structure of the lung and its cyclic deformation during the respiratory cycle, epithelial cells are exposed to continuously varying levels of mechanical stresses. While normal lung function is maintained under these conditions, changes in mechanical stresses can have profound effects on the function of epithelial cells and therefore the function of the organ. In this review, we will describe the types of stresses and strains in the lungs, how these are transmitted, and how these may vary in human disease or animal models. Many approaches have been developed to better understand how cells sense and respond to mechanical stresses, and we will discuss these approaches and how they have been used to study lung epithelial cells in culture. Understanding how cells sense and respond to changes in mechanical stresses will contribute to our understanding of the role of lung epithelial cells during normal function and development and how their function may change in diseases such as acute lung injury, asthma, emphysema, and fibrosis. © 2012 American Physiological Society.Compr Physiol2:1‐29, 2012.
The birth and early growth of a comprehensive multidisciplinary diabetes center in a community hospital: The Bildirici Center for Diabetes Care and Research at Laniado Hospital
Authors: Niven Mordechai (Mark) 
Published: January 2012

SummaryDiabetes is a multisystem disorder. Diabetes care is a multidisciplinary process. The Bildirici Center for Diabetes Care and Research opened its doors to its first patients in August 2007, as the first center in Israel to offer comprehensive integrated multidisciplinary care for people with diabetes. In addition to direct patient care, the Center has organized courses, lectures and workshops for people with diabetes, as well as for professionals caring for people with diabetes and for the general community. The ability of individuals within different departments to develop and implement such a center may have been facilitated by the smallness of our institution and the familiarity they share as a result. We have shown how a community hospital, without ties to a major medical center or academic institution, can establish a multidisciplinary inpatient and outpatient diabetes center, the first of its kind in a country. Copyright © 2012 John Wiley & Sons, Ltd.
Diabetic fatty liver disease is associated with specific changes in blood‐borne markers
Authors: Sharma S. , Barrett F. , Adamson J. , Todd A. , Megson I. L. , Zentler‐Munro P. L. , MacRury S. M. 
Published: January 2012

AbstractBackgroundNon‐alcoholic fatty liver disease (NAFLD) can lead to cirrhosis and hepatocellular carcinoma and is strongly associated with obesity and insulin resistance. The aim of this study was to assess if plasma markers associated with NAFLD are increased in people with concomitant diabetes compared with those without.MethodsA total of 68 participants were recruited from diabetes and liver clinics. Fatty liver disease was indicated by routine blood tests and ultrasonography. Forty‐seven participants had type 2 diabetes; of them, 18 had no fatty liver disease as defined previously (DNoFLD) and 29 had fatty liver disease (DFLD); the remaining 21 had fatty liver disease but no diabetes (NonDFLD). Serum samples were analyzed for adiponectin (APN), alanine and aspartate aminotransferases and plasma for cholesterol, triglyceride, hyaluronic acid (HA), procollagen peptide III, alkaline phosphatase and fibrinogen.ResultsHyaluronic acid and procollagen peptide III were significantly higher and adiponectin significantly lower in DFLD than NonDFLD and DNoFLD, the difference being particularly marked for hyaluronic acid and APN. There was no difference in these markers between NonDFLD and DNoFLD and no association between any plasma or serum marker and ultrasound grade of steatosis.ConclusionWe have identified markers of hepatic steatosis that appear to be specific for people with type 2 diabetes. A further longitudinal study is merited to assess the role of these markers in understanding the progression of hepatic steatosis and fibrosis in people with and without diabetes. Copyright © 2012 John Wiley & Sons, Ltd.
Iminoether Complexes of the Type, fac‐[Re(CO)3L{HNC(CH3)OCH3}]BF4 (L = Bipyridine or a Substituted Bipyridine): Synthesis and Properties
Authors: Perera Theshini , Abhayawardhana Pramuditha , Fronczek Frank R. , Marzilli Patricia A. , Marzilli Luigi G. 
Published: January 2012

AbstractThe methyl acetimidate (an iminoether) complexes, fac‐[Re(CO)3L{HNC(CH3)OCH3}]BF4 [where L = 2,2′‐bipyridine (bipy), 4,4′‐Me2bipy, 5,5′‐Me2bipy, or 6,6′‐Me2bipy], were formed when fac‐[Re(CO)3(CH3CN)3]BF4 in acetonitrile/methanol was treated with 2,2′‐bipyridine (bipy) or the dimethyl‐2,2′‐bipyridines (4,4′‐Me2bipy, 5,5′‐Me2bipy, or 6,6′‐Me2bipy). Structural analysis of the four fac‐[Re(CO)3L{HNC(CH3)OCH3}]BF4 complexes revealed that all of the complexes crystallize with the iminoether ligand in the Z configuration and that distortions in L that involved the two pyridyl rings are minor except for 6,6′‐Me2bipy, which is highly distorted. This distortion of the 6,6′‐Me2bipy ligand is reflected in the NMR‐spectroscopic data. Upon complex formation, the methyl group signal in the 13C NMR spectrum shifted downfield significantly for 6,6′‐Me2bipy, but this did not occur in the 13C NMR spectrum of the 5,5′‐Me2bipy complex. The reaction times for forming the respective fac‐[Re(CO)3L{HNC(CH3)OCH3}]BF4 complexes for these two ligands were comparable, which indicated that the differences in the distortion of L and the methyl substituent position have little influence on the ease of iminoether formation. However, a higher steric bulk of the alcohol (methanol, ethanol, and2‐propanol) decreases the ease of fac‐[Re(CO)3(5,5′‐Me2bipy){HNC(CH3)OR}]BF4 formation. Isopropanol did not form the iminoether complex after two days of heating the reaction mixture at reflux. The low reactivity of the alcohols tested versus the amines that were tested previously suggests that selective bioconjugation to the fac‐{99mTc(CO)3}+ core through an amidine linkage is feasible for biomolecules that have both amine and hydroxy groups. Finally, a comparison of the C≡N bond lengths that were obtained for the fac‐[Re(CO)3(CH3CN)3]BF4/PF6 complexes with those values obtained for other rhenium acetonitrile complexes revealed that there is no significant difference between the C≡N bond lengths and that there is no correlation to the acetonitrile reactivity. It is possible that the fac‐{Re(CO)3}+ core stabilizes the transition state for amine or alcohol addition.
On the Coordination of Dinitrogen to Group 4 Metallocenes
Authors: Peigné Benjamin , Cano Joan , Aullón Gabriel 
Published: January 2012

AbstractA theoretical study on the basis of DFT calculations for complexes with the general formula [{MCp2}2N2] (M = Ti, Zr, or Hf; Cp = cyclopentadienyl ligand) is presented. The relative stability of side‐on and end‐on isomers is determined for each metal atom. A survey of the electronic structure and molecular orbitals provides a simple interpretation of the chemical bonding within the M2N2 unit and reveals the factors that determine the choice of the coordination mode of dinitrogen to metallocenes. These results have been confirmed by vibrational calculations and topological analysis of the electron density together with a structural database study. The influence of the conformational changes on some molecular properties and their implications for the N–N bonding character will be discussed.
A New Silver‐Based Precursor as Ink for Soft Printing Techniques
Authors: Fritsch Julia , Schumm Benjamin , Biedermann Ralf , Grothe Julia , Kaskel Stefan 
Published: January 2012

AbstractA new, easily obtainable silver–pyrrolidone complex that is suitable for printing applications was synthesized by the reaction of silver nitrate and 2‐pyrrolidone (Pyl) at room temperature. According to single‐crystal X‐ray crystallographic studies, the product [Ag(Pyl)2]NO3 crystallizes in the monoclinic space group C2/c (no. 15) [a = 5.358(1) Å, b = 15.217(3) Å, c = 14.986(3) Å, β = 99.296(6)°]. Highly concentrated solutions of the complex can be obtained in an ethanol/water mixture, thereby allowing for the manufacture of thin films by means of dip coating. Subsequent UV irradiation and moderate‐temperature treatment yielded compact films of elemental silver with thicknesses of about 100 nm and sheet resistances down to 6.5 Ω. Furthermore, microcontact printing (μcp) and embossing of [Ag(Pyl)2]NO3 were performed, also followed by UV treatment. By means of the photoreduction of the complex and subsequent moderate‐thermal treatment, defined structures of elemental silver lines were obtained.
Temporal variability of suspended sediment sources in an alpine catchment combining river/rainfall monitoring and sediment fingerprinting
Authors: Navratil Oldrich , Evrard Olivier , Esteves Michel , Legout Cédric , Ayrault Sophie , Némery Julien , Mate‐Marin Ainhoa , Ahmadi Mehdi , Lefèvre Irène , Poirel Alain , Bonté Philippe 
Published: January 2012

ABSTRACTInfluence of the rainfall regime on erosion and transfer of suspended sediment in a 905‐km² mountainous catchment of the southern French Alps was investigated by combining sediment monitoring, rainfall data, and sediment fingerprinting (based on geochemistry and radionuclide concentrations). Suspended sediment yields were monitored between October 2007 and December 2009 in four subcatchments (22–713 km²). Automatic sediment sampling was triggered during floods to trace the sediment origin in the catchment.Sediment exports at the river catchment outlet (330 ± 100 t km‐2 yr‐1) were mainly driven (80%) by widespread rainfall events (long duration, low intensities). In contrast, heavy, local and short duration storms, generated high peak discharges and suspended sediment concentrations in small upstream torrents. However, these upstream floods had generally not the capacity to transfer the sediment down to the catchment outlet and the bulk of this fine sediment deposited along downstream sections of the river. This study also confirmed the important contribution of black marls (up to 70%) to sediment transported in rivers, although this substrate only occupies c. 10% of the total catchment surface. Sediment exports generated by local convective storms varied significantly at both intra‐ and inter‐flood scales, because of spatial heterogeneity of rainfall. However, black marls/marly limestones contribution remained systematically high. In contrast, widespread flood events that generate the bulk of annual sediment supply at the outlet were characterized by a more stable lithologic composition and by a larger contribution of limestones/marls, Quaternary deposits and conglomerates, which corroborates the results of a previous sediment fingerprinting study conducted on riverbed sediment. Copyright © 2012 John Wiley & Sons, Ltd.
Neural basis of recollection in first‐episode major depression
Authors: van Eijndhoven Philip , van Wingen Guido , Fernández Guillén , Rijpkema Mark , Pop‐Purceleanu Monica , Verkes Robbert Jan , Buitelaar Jan , Tendolkar Indira 
Published: January 2012

AbstractBackground. Patients with major depressive disorder (MDD) display impairments in recollection, which have been explained by both hippocampal and prefrontal dysfunction. Here, we used an event‐related fMRI design, to dissociate hippocampal and prefrontal contributions to the neural processes involved in recollection success and recollection attempt early in the course of MDD. Methods. To disentangle state‐ and trait‐effects of depression, we included 20 medication‐naive patients with a first depressive episode, 20 medication‐free patients recovered from a first episode, and 20 matched, healthy controls in an event‐related fMRI study using a source recollection paradigm. Results. Group comparisons revealed that during the acute state of depression there is an increase in left prefrontal activity related to recollection attempt, while there were no differences in neural correlates of successful recollection. Conclusions. Our results indicate that in the early course of depression, depressive state is associated with increased left prefrontal activation during the attempt to recollect source information suggesting an increased need for executive control during recollection in MDD. In this sample of first‐episode MDD patients we found no evidence for hippocampal dysfunction. Hum Brain Mapp, 2013. © 2012 Wiley Periodicals, Inc.
The pace of prosodic phrasing couples the listener's cortex to the reader's voice
Authors: Bourguignon Mathieu , De Tiège Xavier , de Beeck Marc Op , Ligot Noémie , Paquier Philippe , Van Bogaert Patrick , Goldman Serge , Hari Riitta , Jousmäki Veikko 
Published: January 2012

AbstractWe studied online coupling between a reader's voice and a listener's cortical activity using a novel, ecologically valid continuous listening paradigm. Whole‐scalp magnetoencephalographic (MEG) signals were recorded from 10 right‐handed, native French‐speaking listeners in four conditions: a female (Exp1f) and a male (Exp1m) reading the same text in French; a male reading a text in Finnish (Exp 2), a language incomprehensible for the subjects, and a male humming Exp1 text (Exp 3). The fundamental frequency (f0) of the reader's voice was recorded with an accelerometer attached to the throat, and coherence was computed between f0 time‐course and listener's MEG. Similar levels of right‐hemisphere‐predominant coherence were found at ˜0.5 Hz in Exps 1–3. Dynamic imaging of coherent sources revealed that the most coherent brain regions were located in the right posterior superior temporal sulcus (pSTS) and posterior superior temporal gyrus (pSTG) in Exps 1–2 and in the right supratemporal auditory cortex in Exp 3. Comparison between speech rhythm and phrasing suggested a connection of the observed coherence to pauses at the sentence level both in the spoken and hummed text. These results demonstrate significant coupling at ∼0.5 Hz between reader's voice and listener's cortical signals during listening to natural continuous voice. The observed coupling suggests that voice envelope fluctuations, due to prosodic rhythmicity at the phrasal and sentence levels, are reflected in the listener's cortex as rhythmicity of about 2‐s cycles. The predominance of the coherence in the right pSTS and pSTG suggests hemispherical asymmetry in processing of speech sounds at subsentence time scales. Hum Brain Mapp, 2013. © 2012 Wiley Periodicals, Inc.