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1.
Theriogenology ; 210: 227-233, 2023 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-37540955

RESUMO

A retrospective study was carried out to investigate incidence, clinical signs and ultrasonographic findings of ovarian tumours in a population of dogs referred to the Veterinary Teaching Hospital of the University of Perugia (Italy) and Anicura Tyrus Veterinary Clinic (Terni, Italy). The period of study ranged from January 2005 to December 2021. A total of 1910 dogs were affected by neoplasia but only 35 of them (1.8%), of different breeds and ages, were found to have ovarian tumours. Ultrasound of the ovaries was performed based on clinical signs; the diagnosis was achieved after ultrasound findings prompted ovariohysterectomy and ovarian pathologic evaluation In our study, the age of bitches affected by ovarian neoplasia ranged from 3 to 20 years (mean 9.6 ± 3.8). The histopathological findings of ovarian masses identified 16 granulosa cell tumours (GCT) (46%), 7 adenomas (20%), 5 adenocarcinomas (14%), 2 teratomas (6%), 1 leiomyoma (3%), 1 luteoma (3%), 1 tecoma (3%), 1 dysgerminoma (3%), and 1 haemangiosarcoma (3%). In particular, with respect to clinical signs, 69% of bitches showed abnormalities of estrus cycle (short interestral interval, persistent estrus, prolonged interestral interval). The other main clinical signs included abdominal distention, palpable abdominal mass, vulvovaginal discharge, polyuria/polydipsia, mammary masses. When present, the laboratory abnormalities were slight anemia and leucocytosis with neutrophilia. The tumours were ultrasonographically classified as mainly solid: 12/35 (34%) (1 adenoma, 4 adenocarcinomas, 1 dysgerminoma, 1 haemangiosarcoma, 1 leyomioma, 1 luteoma, 1 GCT, 1 tecoma, 1 teratoma); solid with cystic component 13/35 (37%) (9 GCT, 2 Adenomas, 1 adenocarcinoma, 1 teratoma); and mainly cystic 10/35 (29%) (6 GCTs, 4 adenomas). In our study, the ultrasound examination allowed us to suspect ovarian neoplasia in asymptomatic subjects referred for breeding management or for preventive health check. On the basis of our data, we proposed to perform a complete periodic examination of the reproductive system once a year from 6 years. Nevertheless, the presence of ovarian neoplasms found in young subjects, during breeding management, suggest including routine ultrasound examination of the reproductive tract.


Assuntos
Adenocarcinoma , Adenoma , Disgerminoma , Tumor de Células da Granulosa , Hemangiossarcoma , Luteoma , Neoplasias Ovarianas , Teratoma , Feminino , Animais , Cães , Disgerminoma/patologia , Disgerminoma/veterinária , Estudos Retrospectivos , Luteoma/veterinária , Hemangiossarcoma/veterinária , Hospitais Veterinários , Hospitais de Ensino , Neoplasias Ovarianas/diagnóstico por imagem , Neoplasias Ovarianas/veterinária , Tumor de Células da Granulosa/diagnóstico , Tumor de Células da Granulosa/veterinária , Adenocarcinoma/veterinária , Teratoma/patologia , Teratoma/veterinária , Adenoma/diagnóstico por imagem , Adenoma/veterinária
2.
Theriogenology ; 198: 164-171, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36587540

RESUMO

Extracellular vesicles (EVs) are small spherical particles surrounded by a membrane with an unusual lipid composition and a striking cholesterol/phospholipidic ratio. About 2000 lipid and 3500 protein species were identified in EVs secreted by different cell sources. EVs mediate cell to cell communication in proximity to or distant from the cell of origin. In particular, it was suggested that they represent modulators of multiple processes during pregnancy. The aim of this study was to identify the presence of EVs in canine amnion-derived cells (ASCs) culture and the expression of CD 59 on their surface. Amniotic membrane was collected in PBS with antibiotics added from 2 bitches during elective caesarean section. Cells culture was prepared and EVs were isolated. EVs were used to evaluate CD59 expression by flow cytofluorimetry. We found that the majority of EVs expressed CD59. Our results could increase the knowledge about the complex mechanisms that regulate the pregnancy in the bitch.


Assuntos
Âmnio , Vesículas Extracelulares , Animais , Cães , Feminino , Gravidez , Âmnio/metabolismo , Técnicas de Cultura de Células/veterinária , Cesárea/veterinária , Vesículas Extracelulares/fisiologia , Lipídeos , Antígenos CD59/metabolismo
3.
Theriogenology ; 147: 192-196, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-31767185

RESUMO

Apelin is a potent inotropic agent causing endothelium-mediated vasodilation and is involved in vessel formation by interacting with a specific receptor. Its cardiovascular profile suggests a role in the regulation of gestational hemodynamic changes. The expression of apelin and its receptor has been reported in some portions of the reproductive tract of different mammalian species. As far as we know, there are no reports describing the expression of apelin and apelin receptor in bitch's placenta. Therefore, the aim of this study was to investigate, for the first time, the presence and distribution of apelin and apelin receptor in bitch placenta by molecular biology and immunohistochemical techniques. Sixteen adult female half-breed bitches were used. The animals were divided into two groups based on the stage of pregnancy: group 1 (mid-gestation n = 8) and group 2 (end gestation n = 8). These bitches were subjected to ovariohysterectomy (group1) or non-conservative caesarean section (group 2). The immunohistochemical technique revealed the presence of positive immune reaction for apelin and apelin receptor in all the samples examined at 30 days and at the end of pregnancy. In particular, apelin and apelin receptor staining was evident in the cytoplasms of cytotrophoblasts and in epithelial cells of the maternal portion. Even if not included into the structure of the placenta, the uterine glands also exhibited a positive immune reaction for apelin and apelin receptor. The RT-PCR analysis showed the presence of transcripts for apelin and apelin receptor in all the placenta samples examined. On the basis of our results it was also possible to hypothesize a potential role of apelin in the control of local placenta blood flow during pregnancy development in bitches.


Assuntos
Receptores de Apelina/metabolismo , Apelina/metabolismo , Cães/metabolismo , Placenta/metabolismo , Animais , Apelina/genética , Receptores de Apelina/genética , Feminino , Regulação da Expressão Gênica/fisiologia , Placenta/irrigação sanguínea , Gravidez
4.
Nat Mater ; 16(10): 998-1002, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28892051

RESUMO

The charge mobility of molecular semiconductors is limited by the large fluctuation of intermolecular transfer integrals, often referred to as off-diagonal dynamic disorder, which causes transient localization of the carriers' eigenstates. Using a recently developed theoretical framework, we show here that the electronic structure of the molecular crystals determines its sensitivity to intermolecular fluctuations. We build a map of the transient localization lengths of high-mobility molecular semiconductors to identify what patterns of nearest-neighbour transfer integrals in the two-dimensional (2D) high-mobility plane protect the semiconductor from the effect of dynamic disorder and yield larger mobility. Such a map helps rationalizing the transport properties of the whole family of molecular semiconductors and is also used to demonstrate why common textbook approaches fail in describing this important class of materials. These results can be used to rapidly screen many compounds and design new ones with optimal transport characteristics.

5.
Theriogenology ; 97: 154-158, 2017 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-28583599

RESUMO

Pregnancy and lactation represent critical periods of canine reproductive life and different hormones are required to maintain homeostasis and the correct energy requirements. The aim of this study was to evaluate leptin, insulin, triiodotyronine (T3), thyroxin (T4) and cortisol serum concentrations to better describe the canine maternal energy metabolism. Twelve Bloodhound bitches that had at least one litter and were considered to be healthy submitted blood samples every 15 days starting from day 0 (ovulation) throughout pregnancy up to the end of lactation (day 120). We found that leptin concentrations increased from day 0 to reach maximum value at day 45 (P < 0.001), decreased at day 60 (P < 0.05) and rose again at day 105 and day 120 (P < 0.05 and P < 0.01 respectively). Insulin concentrations significantly increased during pregnancy peaking at day 60 (P < 0.05). After parturition dropped and reached progressively lower values similar to those at day 0 at the end of lactation. During pregnancy Body Weight was in low correlation with leptin (r = 0.32, P < 0.01) and there was no correlation with insulin (r = 0.13, P > 0.1); moreover, no correlation was found during lactation. T3 concentrations showed a U-shaped trend with a significant reduction at day 75 (P < 0.05). T4 concentrations fluctuated without any significant change (ranging from 27.0 ± 1.6 nmol/l to 32.1 ± 1.9 nmol/l). Cortisol concentrations ranged within the reference values (minimal value at day 30 (49.8 ± 6.3 nm/L) and maximal value at day 45 (72.5 ± 16.1 nm/L)). Our study states that canine pregnancy and lactation evoke many hormonal changes necessary to mother and fetuses. In particular, this is the first report regarding the pattern of leptin during whole pregnancy and lactation. The present work lays the groundwork for further studies on endocrine homeostatic mechanisms using the dog as a model for human medicine.


Assuntos
Cães/sangue , Metabolismo Energético/fisiologia , Insulina/sangue , Lactação/sangue , Leptina/sangue , Prenhez , Animais , Cães/fisiologia , Feminino , Homeostase/fisiologia , Hidrocortisona/sangue , Lactação/fisiologia , Gravidez , Prenhez/sangue , Hormônios Tireóideos/sangue
6.
Andrology ; 5(1): 160-168, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27676322

RESUMO

Prostasome-like vesicles (PV) are components of the canine prostatic fluid during ejaculation and despite some enzymatic activities have been identified recently, their functions in the reproductive events in this species are still poorly understood. In this study, we evaluated at neutral or slightly alkaline pH, the effects of different concentrations of purified PV on sperm cell motility characteristics and the impact on the short- and long-term preservation of preserved semen maintained at room temperature. Two different experiments were performed. In the first experiment, purified PV were added at increasing concentration (1.25, 2.5, 5, 10, and 20 µL equivalent to 1, 2, 4, 8, and 16 µg of protein, respectively) to aliquots of 100 µL of preserved semen maintained at 22 °C at the following time points: 0, 30, 60, 120, 240, and 480 min. Computer-assisted sperm motility characteristics and pH were assessed three times at each time points, for each sample and for every concentrations. In the second experiment, the purified PV were added with the same methods as described above but only at time 0. Sperm motility characteristics and pH were assessed over the time. This study showed how the addition of purified PV to preserved semen affects negatively (p < 0.05) at neutral and alkaline pH, both total and progressive motility in a concentration depending manner. Furthermore, prostasome addition was demonstrated to change the quality of sperm movement which may represent a mechanism facilitating sperm cells attachment to the uterine epithelium and facilitating energy preservation before fertilization.


Assuntos
Sêmen , Motilidade dos Espermatozoides/efeitos dos fármacos , Espermatozoides/efeitos dos fármacos , Animais , Cães , Relação Dose-Resposta a Droga , Concentração de Íons de Hidrogênio , Masculino , Preservação do Sêmen/métodos
7.
Theriogenology ; 85(5): 835-840, 2016 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-26613854

RESUMO

A retrospective study was used to investigate the incidence of prostatic diseases in a large population of dogs at Alfort Veterinary Hospital and to clarify epidemiologic features, which might be of a great help to veterinarians in managing and discriminating prostatic disorders. During the investigation period, a total of 72,300 male dogs (coming mainly from the Ile-de-France region) were registered in the Alfort Veterinary College database, and 481 of them (0.7%) were found to have prostatic disorder. The diagnosis was carried out on the basis of clinical signs and ultrasound findings. Among dogs experiencing a prostatic disorder, most frequently recorded diseases were benign prostatic hyperplasia (45.9%) and prostatitis (38.5%), followed by abscesses (7.7%), cysts (5.0%), neoplasia (2.6%), and squamous metaplasia (0.2%). Our study revealed an incidence of 0.3% of prostatic disorders observed in intact male dogs, except in the case of prostatic neoplasia. The mean age of the dogs experiencing prostatic disorders was 8.6 ± 3.2 years. This was significantly different (P < 0.001). Large dogs were significantly more affected by prostatic disorders (P < 0.05), except for prostatic neoplasia. A breed predisposition was suspected in German Shepherd (odds ratio [OR] = 2.1; 95% confidence interval [CI]: 1.5-2.9), Rottweiler (OR = 1.8; 95% CI: 1.2-2.7), American Staffordshire Terrier (OR = 3.8; 95% CI: 2.5-5.8), Berger de Beauce (OR = 3.7; 95% CI: 2.2-6.1), and Bernese Mountain Dog (OR = 2.5; 95% CI: 1.3-4.7).


Assuntos
Doenças do Cão/epidemiologia , Doenças Prostáticas/epidemiologia , Fatores Etários , Animais , Cães , França/epidemiologia , Hospitais Veterinários , Hospitais de Ensino , Incidência , Masculino , Doenças Prostáticas/veterinária , Estudos Retrospectivos
9.
Transl Psychiatry ; 5: e629, 2015 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-26327687

RESUMO

Experiencing an adverse childhood and parental neglect is a risk factor for depression in the adult population. Patients with a history of traumatic childhood develop a subtype of depression that is characterized by earlier onset, poor treatment response and more severe symptoms. The long-lasting molecular mechanisms that are engaged during early traumatic events and determine the risk for depression are poorly understood. In this study, we altered adult depression-like behavior in mice by applying juvenile isolation stress. We found that this behavioral phenotype was associated with a reduction in the levels of the deacetylase sirtuin1 (SIRT1) in the brain and in peripheral blood mononuclear cells. Notably, peripheral blood mRNA expression of SIRT1 predicted the extent of behavioral despair only when depression-like behavior was induced by juvenile--but not adult--stress, implicating SIRT1 in the regulation of adult behavior at early ages. Consistent with this hypothesis, pharmacological modulation of SIRT1 during juvenile age altered the depression-like behavior in naive mice. We also performed a pilot study in humans, in which the blood levels of SIRT1 correlated significantly with the severity of symptoms in major depression patients, especially in those who received less parental care during childhood. On the basis of these novel findings, we propose the involvement of SIRT1 in the long-term consequences of adverse childhood experiences.


Assuntos
Comportamento Animal , Encéfalo/metabolismo , Depressão/metabolismo , Sirtuína 1/metabolismo , Isolamento Social/psicologia , Estresse Psicológico/metabolismo , Animais , Depressão/psicologia , Modelos Animais de Doenças , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Fatores de Risco , Estresse Psicológico/psicologia
10.
Reprod Domest Anim ; 50(1): 91-6, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25414137

RESUMO

This study sought to verify the presence of membranous vesicles in cat seminal plasma by means of transmission electron microscopy and to identify protein profile and some of the enzymatic activities associated with these particles. The transmission electron microscopy observations showed the existence of different sized vesicular membranous structures of more or less spherical shape. These vesicles were surrounded by single-, double- or multiple-layered laminar membranes. The vesicle diameters ranged from 16.3 to 387.4 nm, with a mean of 116.5 ± 70.7 nm. Enzyme activity determinations showed the presence of dipeptilpeptidase IV, aminopeptidase, alkaline and acid phosphatase. To our knowledge, this is the first report that identifies and characterizes the membranous vesicles in cat seminal plasma. However, further studies are necessary to identify the exact site of production of these membranous vesicles in the cat male genital tract and to determine their specific roles in the reproductive events of this species.


Assuntos
Gatos , Vesículas Citoplasmáticas/química , Vesículas Citoplasmáticas/ultraestrutura , Proteínas/análise , Sêmen/química , Fosfatase Ácida/análise , Fosfatase Alcalina/análise , Aminopeptidases/análise , Animais , Vesículas Citoplasmáticas/enzimologia , Dipeptidil Peptidase 4/análise , Masculino , Microscopia Eletrônica de Transmissão , Sêmen/enzimologia
11.
Res Vet Sci ; 95(2): 632-7, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23714041

RESUMO

The present study examines the relationship between reproductive and seminal characteristic with blood flow supply of the testis in male dogs by means of Doppler ultrasonography. Five male dogs were subject to a clinical examination, blood sampling, B-Mode and Doppler ultrasonography of the testis, semen evaluation at collections and after storage at 4°C for 24, 48 and 72 h in three replicates 30 days apart. Peak Systolic Velocity was positively correlated with testicular volume and negatively with live sperm at collections and after 24h. A negative correlation existed between Resistive Index and Pulsatility Index with total and progressive motility at collections and also after 24, 48 and 72 h. Resistive Index and Pulsatility Index were also negatively correlated with the percentage of membrane intact sperms with curled tails at collections while the latter was positively correlated with End Diastolic Velocity. Moreover, positive linear correlations of weight with bilateral testicular volume and total sperm concentration and also between age and abnormal sperm at collections and after 24h were established. The results suggest that the Resistive Index and Pulsatility Index seem to be potential markers of seminal quality in dogs.


Assuntos
Velocidade do Fluxo Sanguíneo/veterinária , Cães/fisiologia , Espermatogênese/fisiologia , Testículo/irrigação sanguínea , Animais , Velocidade do Fluxo Sanguíneo/fisiologia , Masculino
12.
Reprod Domest Anim ; 48(5): 768-73, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23505997

RESUMO

This study was carried out with the objectives to test the differences in the haemodynamic characteristics of the prostatic artery in normal and benign prostatic hyperplasia (BPH)-affected dogs using Doppler ultrasonography. In sixteen male German shepherd dogs, prostatic volume was detected and prostatic biopsy was performed. The prostatic artery blood flow parameters determined were as follows: peak systolic velocity (PSV), end diastolic velocity (EDV), Resistive Index (RI) and Pulsatility Index. The power Doppler mode was used for colour flow mapping of the prostatic artery. In PW mode at marginal locations, the waveforms recorded showed a continuous pattern typical of the high-resistance vessels, while in subcapsular locations, the waveforms recorded were continuous characteristic of the low-resistance vessel. Peak systolic velocity and EDV in both locations were significantly higher in BPH group (p < 0.001) than normal group (p < 0.05). Pixel number in BPH group in both locations was significantly higher (p < 0.05) compared to the normal group. This study shows that Doppler ultrasonography represents a valid and non-invasive method for the characterization of the blood flow in the prostatic artery in dogs affected with BPH. Moreover, statistically significant differences of blood flow velocities in prostatic artery in normal and BPH-affected dogs were detected. The RI was not able to differentiate normal dogs from dogs affected by BPH and therefore is not a parameter usable for diagnostic purposes, while Power Doppler could represent an additional diagnostic tool.


Assuntos
Velocidade do Fluxo Sanguíneo/veterinária , Doenças do Cão/patologia , Próstata/irrigação sanguínea , Hiperplasia Prostática/veterinária , Ultrassonografia Doppler/veterinária , Animais , Velocidade do Fluxo Sanguíneo/fisiologia , Cães , Masculino , Hiperplasia Prostática/patologia , Ultrassonografia Doppler/métodos
13.
Reprod Domest Anim ; 48(4): 673-80, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23320475

RESUMO

In six German Shepherds dogs, GnRH agonist implants (Deslorelin) were inserted subcutaneously one month after histological confirmation of benign prostatic hyperplasia (BPH). Prostatic volume (PV), characteristics of ejaculate, serum testosterone concentrations and Doppler parameters of prostatic and subcapsular arteries were detected at different time intervals, for 6 month. The prostatic volume showed a significantly reduction starting at day 37. The decrease in sperm concentration, motility and increase in morphological abnormal sperm were observed from day 22 to day 37, when it was no longer possible to obtain the ejaculate. The values of peak systolic velocity and end-diastolic velocity in prostatic and subcapsular arteries showed from day 11 a gradual decrease, significant at day 22 until day 37 and reaching the lowest values at day 52 until the end of observation. The power Doppler pixel intensity of both arteries showed a gradual decrease from day 5 until day 52. In particular, a significant decrease was observed for both arteries from day 11. Testosterone serum concentration decreased to undetectable levels by day 11 until the end of the observations. All these Doppler parameters and testosterone values were positively correlated with the prostatic volume. Furthermore, testosterone values were positively correlated with peak systolic velocity, end diastolic velocity and pixel numbers. The use of implants containing GnRH analogues, even in asymptomatic subjects, is effective for the control of BPH and the application of Doppler exam of prostatic blood flow represent an non-invasive tool for monitoring the response of medical treatment.


Assuntos
Doenças do Cão/tratamento farmacológico , Hormônio Liberador de Gonadotropina/agonistas , Próstata/irrigação sanguínea , Hiperplasia Prostática/veterinária , Pamoato de Triptorrelina/análogos & derivados , Animais , Artérias/fisiopatologia , Velocidade do Fluxo Sanguíneo , Cães , Implantes de Medicamento , Masculino , Próstata/patologia , Hiperplasia Prostática/tratamento farmacológico , Hiperplasia Prostática/fisiopatologia , Análise do Sêmen/veterinária , Testosterona/sangue , Pamoato de Triptorrelina/administração & dosagem , Pamoato de Triptorrelina/uso terapêutico , Ultrassonografia Doppler/veterinária
14.
Theriogenology ; 79(2): 219-24, 2013 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-23159403

RESUMO

The aim of the study was to further characterize the relationship between hemodynamic changes in the ovary and luteal function in pregnant and nonpregnant bitches. Fourteen German Shepherd bitches were monitored three times a week from the first day of cytological diestrus (D1) until parturition or the end of diestrus (progesterone <2 ng/mL) by color Doppler, pulsed wave spectral Doppler, and power Doppler (PD) ultrasonography. By means of PD the total number of color pixels were calculated. The Doppler parameters evaluated were: peak systolic velocity (PSV), end diastolic velocity (EDV), and both resistive and pulsatility indices. Blood samples were collected three times a week throughout the experiment to determine progesterone (P4) concentrations. The length of diestrus in pregnant versus nonpregnant group was significantly shorter (P < 0.01; 57 ± 1 vs. 63 ± 1, respectively). By means of pulsed wave spectral Doppler the waveform showed a typical pattern of a low-resistive vessel characterized by a rapid systolic peak followed by a slow telediastolic decrease with a relatively high end-diastolic velocity. Blood flow parameters did not differ between left and right ovary. In both groups PSV and EDV showed a gradual decrease with the progress of diestrus; however, the values of PSV and EDV were significantly higher (P < 0.05) in the pregnant group versus nonpregnant group from D31 to D61 and from D49 to D58 respectively. Moreover, a significantly decrease (P < 0.05) of PSV and EDV in the pregnant group was observed from D46 to D58 and from D49 to D55, respectively. The resistive and pulsatility indices showed an increase during diestrus and the values were significantly lower (P < 0.05) in the pregnant group from D49 to D61. By means of PD, the pixel number was significantly higher (P < 0.05) in the pregnant versus nonpregnant group from D40 to D61. In particular, a significant decrease (P < 0.05) in the pixel number in the pregnant group was observed from D46 to D61. The comparison of the P4 values with the ovarian pixel number in the pregnant and nonpregnant group showed a direct correlation (r = 0.792, N = 59 and r = 0.774, N = 59, respectively). In particular, the P4 values were higher (P < 0.05) in the pregnant than in the nonpregnant group from D37 to D52. In conclusion, significant physiological differences between pregnant and nonpregnant bitches in terms of P4 and ovarian blood supply are reported. In addition it was possible to define that blood flow pattern during diestrus in pregnant bitches is not always closely related with P4 production.


Assuntos
Diestro/fisiologia , Cães/fisiologia , Ovário/irrigação sanguínea , Ovário/diagnóstico por imagem , Ultrassonografia Doppler de Pulso , Ultrassonografia Doppler , Animais , Feminino , Hemodinâmica , Gravidez , Progesterona/sangue , Fluxo Pulsátil , Resistência Vascular
15.
J Chem Phys ; 137(22): 22A508, 2012 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-23249045

RESUMO

The charge recombination reaction from the semiconductor (TiO(2)) conduction band to electron accepting electrolytes (I(2), I(2)(-), I(3)(-)) in dye-sensitised solar cells is investigated theoretically. The non-adiabatic theory of electron transfer has been adapted to compute the charge transfer rate measured in different experimental settings (namely with and without external illumination). In both cases we are able to provide an atomic level description of the charge recombination to the electrolyte (CRE), which is in good agreement with the experimental data available. The model employs a detailed density-functional theory (DFT) description of the semiconductor-electrolyte interface and the internal reorganization energy. A continuum dielectric model is used to evaluate the external component of the reorganization energy due to the solvent degrees of freedom. The intrinsic limitations of DFT are kept to a minimum by taking two key energetic parameters (the conduction band edge and the reaction energy) from the experiments. The proposed methodology correctly reproduces (i) the ratio between CRE rate to iodine and triiodide in dark, (ii) the absolute CRE rate to triiodide in dark, and (iii) the absolute CRE rate to I(2)(-) under illumination.

16.
Transl Psychiatry ; 2: e155, 2012 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-22929597

RESUMO

Social anhedonia, or the diminished capacity to experience pleasure and reward from social affiliation, is a major symptom of different psychiatric disorders, including some forms of infantile autism and schizophrenia spectrum disorders. The brain opioid hypothesis of social attachment is a promising model for achieving insights into how neurobiological and developmental factors contribute to the regulation of social reward. In this study, genetic knocking-out and naltrexone (NTRX) treatment during the first 4 days of life were used to disrupt opioid neurotransmission in mouse pups and their attachment relationships with the mother. Both permanent (genetic) and transient (pharmacological) manipulations of opioid neurotransmission exerted long-term effects on social affiliation. When juveniles, both µ-opioid receptor knockout mice and NTRX-treated pups showed reduced interest in peers and no preference for socially rewarding environment. These results demonstrate that sociability in juvenile mice is highly dependent on the establishment during infancy of a positive affective relationship with their mothers and that opioid neurotransmission has a major role in the regulation of social hedonic capacity. If the validity of this animal model will be confirmed by future research, translational studies focusing on the interaction between early experience and opioid neurotransmission could provide useful insights for identifying endophenotypes of human psychiatric disorders associated with social anhedonia.


Assuntos
Anedonia/fisiologia , Comportamento Animal/fisiologia , Modelos Animais de Doenças , Naltrexona/efeitos adversos , Apego ao Objeto , Transtorno Reativo de Vinculação na Infância/induzido quimicamente , Receptores Opioides mu/genética , Transmissão Sináptica/genética , Análise de Variância , Anedonia/efeitos dos fármacos , Animais , Comportamento Animal/efeitos dos fármacos , Camundongos , Camundongos Knockout , Transtorno Reativo de Vinculação na Infância/genética , Receptores Opioides mu/efeitos dos fármacos , Receptores Opioides mu/fisiologia , Transmissão Sináptica/efeitos dos fármacos , Transmissão Sináptica/fisiologia
17.
Acta Psychiatr Scand ; 122(1): 40-6, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19824987

RESUMO

OBJECTIVE: To evaluate the frequency and clinical correlates of adult separation anxiety disorder in a large cohort of patients with mood and anxiety disorders. METHOD: Overall, 508 outpatients with anxiety and mood disorders were assessed by the structured clinical interview for diagnostic and statistical manual (IV edition) axis I disorders for principal diagnosis and comorbidity and by other appropriate instruments for separation anxiety into adulthood or childhood. RESULTS: Overall, 105 subjects (20.7%) were assessed as having adult separation anxiety disorder without a history of childhood separation anxiety and 110 (21.7%) had adult separation anxiety disorder with a history of childhood separation anxiety. Adult separation anxiety was associated with severe role impairment in work and social relationships after controlling for potential confounding effect of anxiety comorbidity. CONCLUSION: Adult separation anxiety disorder is likely to be much more common in adults than previously recognized. Research is needed to better understand the relationships of this condition with other co-occurring affective disorders.


Assuntos
Ansiedade de Separação/diagnóstico , Ansiedade de Separação/epidemiologia , Transtornos do Humor/diagnóstico , Transtornos do Humor/epidemiologia , Pacientes Ambulatoriais/estatística & dados numéricos , Adulto , Idade de Início , Estudos de Coortes , Comorbidade , Manual Diagnóstico e Estatístico de Transtornos Mentais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Transtorno de Pânico/epidemiologia , Determinação da Personalidade , Desenvolvimento da Personalidade
18.
J Am Chem Soc ; 131(31): 11179-86, 2009 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-19621930

RESUMO

The electronic structure of the charge carrier in one of the most commonly used semiconducting polymers (poly(3-hexylthiophene (P3HT)) is described using a combination of classical and quantum chemical methods. It is shown that the carriers are localized in correspondence with long-lived traps which are present also in the crystalline phase of the polymer. The existence of activated transport for very ordered polymer phases (regardless of the strength of the polaron formation energy) is explained, and the trapped states, postulated by many phenomenological models, are described for the first time with chemical detail. It is shown that computational chemistry methods can be used to fill the gap between phenomenological descriptions of charge transport in polymers and microscopic descriptions of the individual quantum dynamic processes.

19.
J Chem Phys ; 129(4): 044704, 2008 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-18681667

RESUMO

Terahertz transient conductivity measurements are performed on pentacene single crystals, which directly demonstrate a strong coupling of charge carriers to low frequency molecular motions with energies centered around 1.1 THz. We present evidence that the strong coupling to low frequency motions is the factor limiting the conductivity in these organic semiconductors. Our observations explain the apparent paradox of the "bandlike" temperature dependence of the conductivity beyond the validity limit of the band model.

20.
Neurosci Lett ; 424(3): 179-84, 2007 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-17719176

RESUMO

Homozygosis for wolframin (WFS1) mutations determines Wolfram syndrome (WS), and common polymorphisms of WFS1 are associated with psychiatric illnesses and dependence behaviour. To test the influence of WFS1 polymorphisms on medication overuse headache (MOH), a chronic headache condition related to symptomatic drugs overuse, we analyzed 82 MOH patients for the WFS1 His611Arg polymorphism, and performed a comparison between clinical features of Arg/Arg (R/R) and non-R/R individuals. Individuals harbouring the R/R genotype showed significantly higher monthly drug consumption (t=-3.504; p=0.00075) and more severe depressive symptoms on the BDI questionnaire (t=-3.048; p=0.003) than non-R/R. WFS1 polymorphism emerged as the only significant predictor of drug consumption, at the multivariate regression analysis (F=12.277; d.f.=1,80; p=0.00075, adjusted R2=0.122). These results implicate WFS1 in the clinical picture of MOH, may be through an influence on need for drugs as in other conditions of abuse behaviour.


Assuntos
Arginina/genética , Predisposição Genética para Doença , Cefaleia/genética , Histidina/genética , Proteínas de Membrana/genética , Polimorfismo Genético , Adulto , Estudos de Casos e Controles , Análise Mutacional de DNA/métodos , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Feminino , Cefaleia/induzido quimicamente , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada
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