A ruthenium catalyst linked to a redox-active ruthenium polypyridine for water oxidation.

Chromophore-catalyst assemblies are interesting benchmark molecules for photocatalysis. We have prepared two examples of these assemblies and characterized their behaviour as catalysts for the water oxidation reaction. In the bimetallic complexes [Ru(tpy)(4,4'-X-bpy)(μ-CN)Ru(bda)(DMSO)](PF) (X = -H (1), -OCH (2), tpy = 2,2':6',2''-terpyridine, bpy = 2,2'-bipyridine, Hbda = 2,2'-bipyridine-6,6'-dicarboxylic acid and DMSO = (CH)SO), a Ru(II)-polypiridine chromophore {Ru(tpy)(4,4'-X-bpy)} is linked by a cyanide bridge to a {Ru(bda)} water oxidation catalyst.

Tuning Energetics of 2 e/2H PCET Properties with Model Ru-bisamido Complexes.

Most redox processes that break/form bonds involve net 2e changes, and many are coupled to protons. Yet most proton-coupled electron transfer (PCET) studies focus on 1e/1H reactions. Reported here is a family of molecular models that undergo tunable 2e/2H redox changes.

Coupling between two Ru(bda) catalysts bridged by a -dicyano complex.

We have prepared two trimetallic complexes [{Ru(bda)(DMSO)(μ-CN)}Ru(L)] (with bda = 2,2'-bipyridine-6,6'-dicarboxylate) where two {Ru(bda)} centers are bridged by a cyanide complex of the -Ru(L)CN family (with L = pyridine and 4--butylpyridine). The complex [{Ru(bda)(DMSO)(μ-CN)}Ru(py)] is fully soluble in aqueous solution and is a catalyst for the oxidation of water both chemically, using Ce(IV) at pH = 1 as the terminal oxidant, and electrochemically. Both reactions are first order in the complex and the resting state of the catalyst is the [RuVRuIII(py)4RuIV]2+ redox state.

Ru Monoimines with Extended Excited-State Lifetimes and Geometrical Modulation of Photoinduced Mixed-Valence Interactions.

The photophysical properties of monodentate-imine ruthenium complexes do not usually fulfil the requirements for supramolecular solar energy conversion schemes. Their short excited-state lifetimes, like the 5.2 ps metal-to-ligand charge transfer (MLCT) lifetime of [Ru(py)Cl(L)] with L = pz (pyrazine), preclude bimolecular or long-range photoinduced energy or electron transfer reactions.

Single-Cell Proteomics Analysis of Recurrent Low-Grade Serous Ovarian Carcinoma and Associated Brain Metastases.

Between 2% and 6% of epithelial ovarian cancer (EOC) patients develop brain metastases (brain mets), which are incurable and invariably result in death. This poor outcome is associated with a lack of established guidelines for the detection and treatment of brain mets in EOC patients. In this study, we characterize an unusual case of low-grade serous ovarian carcinoma (LGSOC) that metastasized to the brain.

New ruthenium polypyridyl complexes as potential sensors of acetonitrile and catalysts for water oxidation.

New ruthenium(ii) polypyridyl complexes of formulae [RuCl(MeNtrpy)(bpy-OMe)]Cl, 1, and [Ru(MeNtrpy)(bpy-OMe)(OH)](CFSO), 2, with MeNtrpy = 4'-,-dimethylamino-2,2':6',2''-terpyridine and bpy-OMe = 4,4'-dimethoxy-2,2'-bipyridine, were synthetized and characterized by spectroscopic and electrochemical techniques. Besides, [Ru(MeNtrpy)(bpy-OMe)(NCCH)], 3, was obtained and characterized by UV-vis spectroscopy in acetonitrile solution. All experimental results were complemented with DFT and TD-DFT calculations.

Lung-borne systemic inflammation in mechanically ventilated infant rats due to high PEEP, oxygen, and hypocapnia.

Background: Intensive care practice calls for ventilator adjustments due to fast-changing clinical conditions in ventilated critically ill children. These adaptations include positive end-expiratory pressure (PEEP), fraction of inspired oxygen (FiO), and respiratory rate (RR). It is unclear which alterations in ventilator settings trigger a significant systemic inflammatory response.

Operant conditioning with a stimulus discrimination: An alternative method for evaluating alcohol reinforcement in preweaning rats.

Background: Ethanol exposure at early ontogeny promotes further predisposition to consume the drug. Operant conditioning allows motivational alcohol properties to be assessed. To date, the operant conditioning approach used during infancy consisted in paired subjects being trained to learn an operant response, using simultaneously a yoked partner, which received reinforcer solution as a result of a paired animal instrumental response (OYS).

Early ethanol pre-exposure alters breathing patterns by disruptions in the central respiratory network and serotonergic balance in neonate rats.

Early ethanol exposure alters neonatal breathing plasticity. Respiratory EtOH's effects are attributed to central respiratory network disruptions, particularly in the medullary serotonin (5HT) system. In this study we evaluated the effects of neonatal pre-exposure to low/moderate doses upon breathing rates, activation patterns of brainstem's nuclei and expression of 5HT 2A and 2C receptors.

Fetal Alcohol Programming of Subsequent Alcohol Affinity: A Review Based on Preclinical, Clinical and Epidemiological Studies.

The anatomo-physiological disruptions inherent to different categories of the Fetal Alcohol Spectrum Disorder do not encompass all the negative consequences derived from intrauterine ethanol (EtOH) exposure. Preclinical, clinical and epidemiological studies show that prenatal EtOH exposure also results in early programming of alcohol affinity. This affinity has been addressed through the examination of how EtOH prenatally exposed organisms recognize and prefer the drug's chemosensory cues and their predisposition to exhibit heightened voluntary EtOH intake during infancy and adolescence.

Prenatal ethanol exposure and enkephalinergic neurotransmission.

Endogenous opioids (enkephalins, endorphins and dynorphins) are small peptides that play a main role in pain perception and analgesia, as well as in alcohol (ethanol) reinforcement and reward. Alcohol reinforcement involves the ethanol-induced activation of the endogenous opioid system, a process that may augment the hedonic value and the reinforcing properties of the drug, which in turn increases substance consumption. Changes in opioidergic transmission may contribute to alcohol intoxication and to the neuroadaptive responses produced by the long-lasting exposure to ethanol.

Hyperlocomotion and anxiety- like behavior induced by binge ethanol exposure in rat neonates. Possible ameliorative effects of Omega 3.

Maternal alcohol consumption during pregnancy may cause neurocognitive and behavioral disorders that can persist until adulthood. Epidemiological data has revealed an alarming increase in the frequency of alcohol intake in pregnant women. Nutritional variables may also have an impact on the behavioral alterations occasioned by alcohol during development.

Maternal manipulation during late gestation (GDs 17-20) enhances ethanol consumption and promotes changes and opioid mRNA expression in infant rats.

Fetal ethanol experience generates learning and memories capable to increase ethanol consummatory behaviors during infancy. Opioid system seems to be involved in mediating those alcohol-related behaviors. In this work, we proposed to study the impact of prenatal exposure to a moderate ethanol dose, upon ingestion of the drug and possible ethanol-induced molecular changes on opioid precursor peptides (POMC, Pro-enk and Pro-DYN) and receptors (MOR, DOR and KOR) mRNA expression, in hypothalamus.

Context-dependent reinstatement of an extinguished operant response in preweanling rats.

It is frequently assumed that infants are impaired in contextual memory and consequently, in recovery from extinction, a phenomenon considered to be context dependent. However, the evidence in the field is far from consistent with this interpretation, since several studies have shown context-dependent extinction in infant rats using a variety of procedures and behavioral measures. This discussion has primarily been based on studies using Pavlovian conditioning tasks.

Brief ethanol exposure and stress-related factors disorganize neonatal breathing plasticity during the brain growth spurt period in the rat.

Rationale: The effects of early ethanol exposure upon neonatal respiratory plasticity have received progressive attention given a multifactorial perspective related with sudden infant death syndrome or hypoxia-associated syndromes. The present preclinical study was performed in 3-9-day-old pups, a stage in development characterized by a brain growth spurt that partially overlaps with the 3rd human gestational trimester.

Methods: Breathing frequencies and apneas were examined in pups receiving vehicle or a relatively moderate ethanol dose (2.

Ellagitannin HeT obtained from strawberry leaves is oxidized by bacterial membranes and inhibits the respiratory chain.

Plant secondary metabolism produces a variety of tannins that have a wide range of biological activities, including activation of plant defenses and antimicrobial, anti-inflammatory and antitumoral effects. The ellagitannin HeT (1--galloyl-2,3;4,6-bis-hexahydroxydiphenoyl-β-d-glucopyranose) from strawberry leaves elicits a strong plant defense response, and exhibits antimicrobial activity associated to the inhibition of the oxygen consumption, but its mechanism of action is unknown. In this paper we investigate the influence of HeT on bacterial cell membrane integrity and its effect on respiration.

Mechanical ventilation strategies alter cardiovascular biomarkers in an infant rat model.

Mechanical ventilation (MV) is routinely used in pediatric general anesthesia and critical care, but may adversely affect the cardiocirculatory system. Biomarkers are increasingly measured to assess cardiovascular status and improve clinical treatment decision-making. As the impact of mechanical ventilation strategies on cardiovascular biomarkers in ventilated infants is largely unknown, we conducted this retrospective study in a healthy in vivo infant rat ventilation model using 14-days old Wistar rats.

Context-dependent extinction of an appetitive operant conditioned response in infant rats.

The present study evaluated context-dependent learning under an operant conditioning procedure in infant rats. Preweanling rats were trained in context A during postnatal days (PDs) 16 and 17 to learn an appetitive operant conditioning task, employing milk chocolate as appetitive reinforcer. On PD18 the operant response was extinguished in context A, or in an alternative context B.

Prenatal ethanol exposure modifies locomotor activity and induces selective changes in Met-enk expression in adolescent rats.

Several studies suggest that prenatal ethanol exposure (PEE) facilitates ethanol intake. Opioid peptides play a main role in ethanol reinforcement during infancy and adulthood. However, PEE effects upon motor responsiveness elicited by an ethanol challenge and the participation of opioids in these actions remain to be understood.

Conditioned breathing depression during neonatal life as a function of associating ethanol odor and the drug's intoxicating effects.

Fetal and neonatal ethanol-related alterations upon the respiratory system have been described in different mammals. Studies also indicate that perinates learn about the sensory attributes of ethanol and associate them with diverse physiological effects of the state of intoxication. The present study was conducted in rat neonates during a developmental stage equivalent to the third human gestational trimester.

Prenatal binge-like alcohol exposure alters brain and systemic responses to reach sodium and water balance.

The aim of the present work is to analyze how prenatal binge-like ethanol exposure to a moderate dose (2.0 g/kg; group Pre-EtOH) during gestational days (GD) 17-20 affects hydroelectrolyte regulatory responses. This type of exposure has been observed to increase ethanol consumption during adolescence (postnatal day 30-32).

Prenatal ethanol exposure alters met-enkephalin expression in brain regions related with reinforcement: possible mechanism for ethanol consumption in offspring.

The endogenous opioid system is involved in ethanol reinforcement. Ethanol-induced changes in opioidergic transmission have been extensively studied in adult organisms. However, the impact of ethanol exposure at low or moderate doses during early ontogeny has been barely explored.

Maternal isolation during the first two postnatal weeks affects novelty-induced responses and sensitivity to ethanol-induced locomotor activity during infancy.

Animals exposed to chronic maternal separation (MS) exhibit enhanced ethanol self-administration and greater hormonal and behavioral responsiveness to stress in adulthood. Whether the effects of MS are immediately evident in infancy or whether they appear only later on development is still an unanswered question This study tested sensitivity to ethanol's behavioral stimulating effects in infant rats that experienced MS from postnatal Day 1-14. MS infants exhibited significantly greater reactivity to the motor stimulating effects of 1.

Acetaldehyde involvement in ethanol's postabsortive effects during early ontogeny.

Clinical and biomedical studies sustains the notion that early ontogeny is a vulnerable window to the impact of alcohol. Experiences with the drug during these stages increase latter disposition to prefer, use or abuse ethanol. This period of enhanced sensitivity to ethanol is accompanied by a high rate of activity in the central catalase system, which metabolizes ethanol in the brain.