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1.
J Dairy Sci ; 104(11): 11609-11620, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34419284

RESUMO

In ruminants, it has been observed that capsicum oleoresin can alter insulin responses and that high-intensity artificial sweetener can increase glucose absorption from the small intestine. Because glucose metabolism and insulin responses are critical during early lactation, these supplements might have an effect on the metabolic status of dairy cows during the transition period. The objective of this experiment was to evaluate the effects of rumen-protected capsicum oleoresin fed alone or in combination with artificial sweetener during the transition period on lactational performance and susceptibility to subclinical ketosis in dairy cows. Fifteen primiparous and 30 multiparous Holstein cows (a total of 39 cows finished the study) were arranged in a randomized complete block design during d -21 to 60 relative to parturition. Cows within block were randomly assigned to one of the following treatments: no supplement (CON), supplementation with 100 mg of rumen-protected capsicum/cow per day (RPCap), or RPCap plus 2 g of high-intensity artificial sweetener/cow per day (RPCapS). For both the RPCap and RPCapS treatments, only rumen-protected capsicum was fed during the dry period. From d 8 to 11 of lactation, intake was limited to 70% of predicted dry matter intake to induce subclinical ketosis. Production variables were recorded daily, samples for milk composition were collected on wk 2, 4, 6, and 8, and blood samples were collected on wk -2, 1, 2, and 4 of the experiment for analysis of metabolic hormones and blood cell counts. Supplementation with rumen-protected capsicum increased serum insulin and decreased ß-hydroxybutyrate concentrations precalving, indicating a decrease in lipolysis. During the lactation period, RPCap was associated with a trend for increased milk production and feed efficiency following the ketosis challenge. Supplementation with RPCapS appeared to negate the response to rumen-protected capsicum. All cows developed subclinical ketosis during the challenge, and this was not affected by treatment. We conclude that treatments did not decrease susceptibility to subclinical ketosis; however, dietary supplementation with rumen-protected capsicum was effective at improving energy status precalving and tended to increased milk production and feed efficiency. The mechanism underlying these responses is unclear.


Assuntos
Capsicum , Rúmen , Ração Animal/análise , Animais , Bovinos , Dieta/veterinária , Suplementos Nutricionais , Lactação , Leite
2.
J Dairy Sci ; 103(1): 410-432, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31733848

RESUMO

This study examined the effect of 3-nitrooxypropanol (3-NOP), a substance under investigation, on enteric methane (CH4) emission, rumen fermentation, lactational performance, sensory properties of milk, and the resumption of ovarian cyclicity in early-lactation dairy cows. Fifty-six multi- and primiparous Holstein cows, including 8 that were rumen cannulated, were used in a 15-wk randomized complete block design experiment. Cows were blocked based on parity and previous lactation milk yield (MY) or predicted MY, and within each block were randomly assigned to one of 2 treatments: (1) control (CON), administered no 3-NOP, or (2) 3-NOP applied at 60 mg/kg of feed dry matter (3-NOP). Enteric CH4 emission was measured during experimental wk 2, 6, 9, and 15, using the GreenFeed system. Dry matter intake (DMI) and MY data were collected daily throughout the experiment, and milk composition samples were collected 7 times during the experiment. Milk samples were collected from 14 to 60 (±2) d after calving, 3 d per week, and assayed for progesterone concentration to determine resumption of ovarian activity. Compared with CON, 3-NOP decreased daily CH4 emission by 26%, CH4 yield (CH4 per kg of DMI) by 21%, and CH4 emission intensity [CH4 per kg of MY or energy-corrected milk (ECM)] by 25%. Enteric emission of carbon dioxide was decreased by 5%, and hydrogen emission was increased 48-fold by 3-NOP. Inclusion of 3-NOP decreased concentration of total volatile fatty acids (by 9.3%) and acetate but increased butyrate molar proportion, ethanol, and formate concentrations in ruminal fluid. Dry matter intake was lower for 3-NOP compared with CON, but DMI expressed as a percentage of body weight was not different between treatments. Treatment had no effect on milk and ECM, body weight change, or body condition score. Milk composition and milk fat and protein yields were not affected by treatment, except that concentrations of short-chain fatty acids in milk were increased by 3-NOP. Nutrient digestibility and blood metabolites and hormones were not affected by 3-NOP, except that insulin was decreased by 3-NOP. There was no effect of 3-NOP on postpartum resumption of ovarian activity, including days to first and second luteal phases, length of first and second luteal phases, and interval from first to second luteal phase. Sensory properties of milk from cows fed 3-NOP and cheese made from that milk were not affected by treatment. In this experiment, 3-NOP decreased daily enteric CH4 emission, emission yield, and emission intensity, improved feed efficiency, and did not affect lactational performance or onset of ovarian activity in early-lactation dairy cows.


Assuntos
Bovinos/fisiologia , Lactação/efeitos dos fármacos , Ovário/fisiologia , Propanóis/farmacologia , Rúmen/efeitos dos fármacos , Animais , Peso Corporal , Dieta/veterinária , Ácidos Graxos Voláteis/metabolismo , Feminino , Fermentação , Metano/metabolismo , Leite/metabolismo , Gravidez , Rúmen/metabolismo
3.
Phys Rev Lett ; 122(10): 101102, 2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30932663

RESUMO

During its orbit around the four million solar mass black hole Sagittarius A* the star S2 experiences significant changes in gravitational potential. We use this change of potential to test one part of the Einstein equivalence principle: the local position invariance (LPI). We study the dependency of different atomic transitions on the gravitational potential to give an upper limit on violations of the LPI. This is done by separately measuring the redshift from hydrogen and helium absorption lines in the stellar spectrum during its closest approach to the black hole. For this measurement we use radial velocity data from 2015 to 2018 and combine it with the gravitational potential at the position of S2, which is calculated from the precisely known orbit of S2 around the black hole. This results in a limit on a violation of the LPI of |ß_{He}-ß_{H}|=(2.4±5.1)×10^{-2}. The variation in potential that we probe with this measurement is six magnitudes larger than possible for measurements on Earth, and a factor of 10 larger than in experiments using white dwarfs. We are therefore testing the LPI in a regime where it has not been tested before.

4.
J Dairy Sci ; 102(10): 8999-9016, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31421886

RESUMO

The objective of this experiment was to evaluate productive and reproductive effects of replacing solvent-extracted soybean meal (SSBM) with extruded soybean meal (ESBM) in a total mixed ration for early-lactation dairy cows. Thirty-four Holstein cows (12 primiparous and 22 multiparous) were used in a randomized complete block design experiment with 17 cows per treatment. Feeding was ad libitum for 5 to 10% refusals. A fresh-cow diet was fed the first 21 d in milk followed by a lactation diet from 22 to 60 d in milk. Milk and dry matter intake data were collected throughout the experiment, and samples were collected for blood chemistry and amino acid profile, nutrient digestibility, nitrogen utilization, and enteric methane emission using the GreenFeed system (C-Lock Inc., Rapid City, SD). Dry matter intake, milk yield, and feed efficiency were not different between SSBM and ESBM. Energy-corrected milk yield and efficiency were also not different between diets. Diet had no effect on milk composition, except that milk true protein yield was decreased by ESBM. Enteric methane emission, yield, and intensity were not different between SSBM and ESBM. Because of its greater fat content, ESBM triggered expected changes in milk fatty acid (FA) profile: decreased sum of C16, saturated, and odd- and branched-chain FA and increased sum of preformed FA, polyunsaturated, and trans FA. The ESBM diet increased or tended to increase some essential amino acids in plasma. In this study, ESBM did not affect dry matter intake and did not improve lactational performance or onset of ovarian function in early-lactation dairy cows, and it decreased milk protein yield, possibly due to greater unsaturated FA intake compared with SSBM.


Assuntos
Bovinos/fisiologia , Ácidos Graxos/análise , Glycine max , Proteínas do Leite/análise , Leite/metabolismo , Reprodução , Ração Animal/análise , Animais , Indústria de Laticínios , Dieta/veterinária , Digestão , Ingestão de Alimentos , Feminino , Lactação , Metano/metabolismo , Leite/química , Rúmen/metabolismo
5.
Anaesthesist ; 67(1): 18-26, 2018 01.
Artigo em Alemão | MEDLINE | ID: mdl-29159491

RESUMO

BACKGROUND: Critical incidents in difficult airway management are still a main contributory factor for perioperative morbidity and mortality. Many national associations have developed algorithms for management of these time critical events. For implementation of these algorithms the provision of technical requirements and procedure-related training are essential. Severe airway incidents are rare events and clinical experience of the individual operators is limited; therefore, simulation is an adequate instrument for training and evaluating difficult airway algorithms. OBJECTIVE: The aim of this observational study was to evaluate the application of the institutional difficult airway algorithm among anesthetists. MATERIAL AND METHODS: After ethics committee approval, anesthetists were observed while treating a "cannot intubate" (CI) and a "cannot intubate, cannot ventilate" (CICV) situation in the institutional simulation center. As leader of a supportive team the participants had to deal with an unexpected difficult airway after induction of anesthesia in a patient simulator. The following data were recorded: sequence of the applied airway instruments, time to ventilation after establishing a secured airway using any instrument in the CI situation and time to ventilation via cricothyrotomy in the CICV situation. Conformity to the algorithm was defined by the sequence of the applied instruments. Analysis comprised conformity to the algorithm, non-parametric tests for time to ventilation and differences between junior and senior anesthetists. RESULTS: Out of 50 participants 45 were analyzed in the CI situation. In this situation 93% of the participants acted in conformity with the algorithm. In 62% the airway was secured by flexible intubation endoscopy, in 38% with another device. Data from 46 participants were analyzed in the CICV situation. In this situation 91% acted in conformity with the algorithm. The last device used prior to the decision for cricothyrotomy was flexible intubation endoscopy in 39%, a laryngeal mask in 22% and other instruments in 39%. Of the 50 participants 38 had already been institutionally trained in difficult airway management during the previous 2 years. For cricothyrotomy the participants needed a median time of 63 s and there was no difference between junior and senior anesthetists (p = 0.46). The cricothyrotomy was performed faster using a surgical approach than a transtracheal puncture approach using a Melker emergency cricothyrotomy set (52 s vs. 73 s, p = 0.014). CONCLUSION: The conformity to the algorithm of over 90% indicates a good training level of the participants concerning the difficult airway algorithm. In the observed sample flexible intubation endoscopy tended to be of high significance even in the unanticipated difficult airway. Cricothyrotomy was performed faster surgically than by the use of the transtracheal puncture approach, while no differences between junior and senior anesthetists were observed. For the successful management of an unexpected difficult airway, specific training of these special and rare events is crucial. A standardized provision of special airway instruments stored in a special trolley and frequent application of this trolley in the clinical routine is recommended.


Assuntos
Manuseio das Vias Aéreas/normas , Intubação Intratraqueal/normas , Simulação de Paciente , Algoritmos , Anestesiologia/educação , Humanos , Máscaras Laríngeas , Modelos Biológicos
6.
Nature ; 481(7379): 51-4, 2011 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-22170607

RESUMO

Measurements of stellar orbits provide compelling evidence that the compact radio source Sagittarius A* at the Galactic Centre is a black hole four million times the mass of the Sun. With the exception of modest X-ray and infrared flares, Sgr A* is surprisingly faint, suggesting that the accretion rate and radiation efficiency near the event horizon are currently very low. Here we report the presence of a dense gas cloud approximately three times the mass of Earth that is falling into the accretion zone of Sgr A*. Our observations tightly constrain the cloud's orbit to be highly eccentric, with an innermost radius of approach of only ∼3,100 times the event horizon that will be reached in 2013. Over the past three years the cloud has begun to disrupt, probably mainly through tidal shearing arising from the black hole's gravitational force. The cloud's dynamic evolution and radiation in the next few years will probe the properties of the accretion flow and the feeding processes of the supermassive black hole. The kilo-electronvolt X-ray emission of Sgr A* may brighten significantly when the cloud reaches pericentre. There may also be a giant radiation flare several years from now if the cloud breaks up and its fragments feed gas into the central accretion zone.

7.
Acta Anaesthesiol Scand ; 61(4): 381-389, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28251605

RESUMO

BACKGROUND: The novel Totaltrack combines a supraglottic airway device with video laryngoscopic tracheal intubation. The intubation laryngeal mask Fastrach is an established device without visual control of intubation. We hypothesized that supraglottic ventilation success with Totaltrack would be similar to Fastrach, but intubation would be performed faster due to visual control of the procedure. METHODS: Fifty-five anaesthesiologists were randomized into one of two study arms: Fastrach Totaltrack. After a standardized introduction, six consecutive attempts of supraglottic ventilation and intubation attempts with each of one of the devices were performed on an airway manikin. The combined primary outcome was: time to supraglottic ventilation and time to ventilation after intubation. Additionally, success rate and learning curves were evaluated. RESULTS: Supraglottic time to ventilation was shorter when using the Fastrach compared to the Totaltrack (median: 7.8 s [confidence interval [CI]: 7.0-8.6 s] vs. 11 s [CI: 7.8-14.2 s], P < 0.001). Intubation was faster using the Fastrach compared to Totaltrack (median: 12.5 s, [CI: 10.1-14.9 s] vs. 23.3 s [CI: 21.5-25.1 s], P < 0.001). Success rate for supraglottic ventilation was comparable between Fastrach and Totaltrack (86-96%). Successful intubation via the device was 100% in Fastrach and ranged from 61% to 93% in Totaltrack, with a higher probability of successful intubation after four applications. CONCLUSION: In this manikin-based study the novel Totaltrack did not prove superior to Fastrach despite a similar design. Video laryngoscopic control of supraglottic ventilation and endotracheal intubation was prolonged using the Totaltrack. Clinical trials are mandatory to evaluate the role of the Totaltrack in airway management.


Assuntos
Intubação Intratraqueal , Máscaras Laríngeas , Manequins , Adulto , Anestesiologistas , Feminino , Humanos , Internato e Residência , Máscaras Laríngeas/efeitos adversos , Laringoscopia , Curva de Aprendizado , Masculino , Estudos Prospectivos , Respiração Artificial/métodos , Resultado do Tratamento , Gravação em Vídeo
8.
Anaesthesist ; 65(11): 822-831, 2016 Nov.
Artigo em Alemão | MEDLINE | ID: mdl-27678137

RESUMO

BACKGROUND: Simulation-based training (SBT) has developed into an established method of medical training. Studies focusing on the education of medical students have used simulation as an evaluation tool for defined skills. A small number of studies provide evidence that SBT improves medical students' skills in the clinical setting. Moreover, they were strictly limited to a few areas, such as the diagnosis of heart murmurs or the correct application of cricoid pressure. Other studies could not prove adequate transferability from the skills gained in SBT to the patient site. Whether SBT has an effect on medical students' skills in anesthesiology in the clinical setting is controversial. To explore this issue, we designed a prospective, randomized, single-blind trial that was integrated into the undergraduate anesthesiology curriculum of our department during the second year of the clinical phase of medical school. OBJECTIVES: This study intended to explore the effect of SBT on medical students within the mandatory undergraduate anesthesiology curriculum of our department in the operating room with respect to basic skills in anesthesiology. MATERIALS AND METHODS: After obtaining ethical approval, the participating students of the third clinical semester were randomized into two groups: the SIM-OR group was trained by a 225 min long SBT in basic skills in anesthesiology before attending the operating room (OR) apprenticeship. The OR-SIM group was trained after the operating room apprenticeship by SBT. During SBT the students were trained in five clinical skills detailed below. Further, two clinical scenarios were simulated using a full-scale simulator. The students had to prepare the patient and perform induction of anesthesia, including bag-mask ventilation after induction in scenario 1 and rapid sequence induction in scenario 2. Using the five-point Likert scale, five defined skills were evaluated at defined time points during the study period. 1) application of the safety checklist, 2) application of basic patient monitoring, 3) establishment of intravenous access, 4) bag-and-mask ventilation, and 5) adjustment of ventilatory parameters after the patients' airways were secured. A cumulative score of 5 points was defined as the best and a cumulative score of 25 as the worst rating for a defined time point. The primary endpoint was the cumulative score after day 1 in the operating room apprenticeship and the difference in cumulative scores from days 1 to 4. Our hypothesis was that the SIM-OR group would achieve a better score after day 1 in the operating room apprenticeship and would gain a larger increase in score from day 1 to day 4 than the OR-SIM group. RESULTS: 73 students were allocated to the OR-SIM group and 70 students to the SIM-OR group. There was no significant difference between the two groups after day 1 of the operating room apprenticeship and no difference in increase of the cumulative score from day 1 to day 4 (median of cumulative score on day 1: 'SIM-OR' 11.2 points vs. 'OR-SIM' 14.6 points; p = 0.067; median of difference from day 1 to day 4: 'SIM-OR' -3.7 vs. 'OR-SIM' -6.4; p = 0.110). CONCLUSION: With the methods applied, this study could not prove that 225 min of SBT before the operating room apprenticeship increased the medical students' clinical skills as evaluated in the operating room. Secondary endpoints indicate that medical students have better clinical skills at the end of the entire curriculum when they have been trained through SBT before the operating room apprenticeship. However, the authors believe that simulator training has a positive impact on students' acquisition of procedural and patient safety skills, even if the methods applied in this study may not mirror this aspect sufficiently.


Assuntos
Competência Clínica , Educação de Graduação em Medicina/métodos , Salas Cirúrgicas , Simulação de Paciente , Estudantes de Medicina , Manuseio das Vias Aéreas , Anestesiologia/educação , Lista de Checagem , Simulação por Computador , Currículo , Feminino , Humanos , Masculino , Segurança do Paciente , Estudos Prospectivos , Respiração Artificial , Método Simples-Cego , Adulto Jovem
9.
bioRxiv ; 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38766084

RESUMO

Subfertility remains a major problem in the dairy industry. Only 35-40% of high-yielding dairy cows and 55-65% of nonlactating heifers become pregnant after their first service. The immune system plays a critical role in the establishment of pregnancy. However, it can also create challenges for embryo survival and contribute to reduced fertility. We conducted 2 separate experiments to characterize changes in subsets of peripheral blood leukocytes (PBL) and their phenotype over the estrous cycle and early pregnancy in heifers and cows. We used flow cytometry and RT-qPCR to assess protein and mRNA expression of molecules important for immune function. We observed that monocytes and T cells were most affected by pregnancy status in heifers, whereas, CD8+ lymphocytes and natural killer (NK) cells were most affected during early pregnancy in cows. Changes in immune parameters measured appeared to be greater in heifers than cows including changes in expression of numerous immune function molecules. To test the hypothesis, we conducted a third experiment to simultaneously analyze the immunological responses to pregnancy between cows and heifers. We observed that cows had greater expression of proinflammatory cytokines and molecules associated with leukocyte migration and phagocytosis compared to heifers. Moreover, animals that failed to become pregnant showed altered expression of anti-inflammatory molecules. Overall, these findings support the hypothesis that early pregnancy signaling alters the proportions and functions of peripheral blood immune cells and differences between cows and heifers may yield insight into the reduced fertility of mature lactating dairy cows.

10.
Phys Rev Lett ; 111(6): 065001, 2013 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-23971579

RESUMO

Crystallization in a two-dimensional strongly coupled plasma from a rapidly cooled fluid is found to be efficiently blocked by an external magnetic field. Beyond a threshold of the magnetic field strength B, the relaxation time to the equilibrium crystal increases exponentially with B, which is attributed to an impeded conversion of potential to kinetic energy. Our finding is opposed to the standard picture of two-dimensional freezing of one-component systems which does not exhibit a nucleation barrier and opens the way to keep two-dimensional fluids metastable over long times.

11.
Phys Rev Lett ; 108(25): 255002, 2012 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-23004607

RESUMO

A first-principles study of the collective oscillation spectrum of a strongly correlated one-component plasma in a strong magnetic field is presented. The spectrum consists of six fundamental modes that are found to be in good agreement with results from the quasilocalized charge approximation. At high frequencies, additional modes are observed that include Bernstein-type oscillations and their transverse counterparts, which are of importance for the high-frequency optical and transport properties of these plasmas.

12.
J Dairy Sci ; 95(11): 6384-7, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22981568

RESUMO

Telomere length variation may provide a quantitative measure of the effects of dairy management and selection practices on animal stress and welfare. The objective of this study was to evaluate the association between telomere length in Holstein cattle with age, herd, and survival. A multiplex quantitative PCR (qPCR) procedure was utilized to estimate telomere length for 201 Holstein cows from 10 herds following DNA extraction from blood. Primers were designed to amplify a 79-bp telomere product and a 144-bp product of a standard reference gene (ß-globin). Both primer sets were included in the same reaction well to enable the analysis of relative quantity (qT) of telomere product compared with ß-globin product. Triplicate samples were run for each cow, and mixed models were used to analyze the qPCR results. Younger cows were significantly associated with higher qT, and significant variation was observed among herds for qT. Cows with short telomeres were more likely to be culled in the subsequent year than cows with above-average telomere lengths. Multiplex qPCR provides a cost-effective method of assessing telomere length. Variation in telomere length might provide insights into how management practices and genetic selection influence cow stress and physiological responses to stress.


Assuntos
Bovinos/fisiologia , Indústria de Laticínios/métodos , Lactação/fisiologia , Encurtamento do Telômero/fisiologia , Fatores Etários , Animais , Feminino , Reação em Cadeia da Polimerase Multiplex/veterinária , Globinas beta/análise
13.
Anaesthesist ; 61(3): 242-8, 2012 Mar.
Artigo em Alemão | MEDLINE | ID: mdl-22430555

RESUMO

In Germany the extent of organ donation is still inadequate and not sufficient to address patients on the waiting lists. Nevertheless, intensive care treatment of potential organ donors does not receive adequate attention. However, because of the increasing age and comorbidities of organ donors in recent years, a sufficient intensive care treatment is indispensable for the success of organ transplantations. Sufficient randomized clinical trials are lacking. This article reviews the current literature and describes approaches for improvement. Multicentre studies and education of medical staff of intensive care units, for example in intensive care simulation for organ protection, could potentially be a successful approach. The improvement and establishment of curricular training and education particularly in simulation workshops might be a promising approach to enhance the quantity and quality of organ donations.


Assuntos
Anestesiologia/educação , Cuidados Críticos/métodos , Educação Médica/tendências , Transplante de Órgãos/métodos , Simulação de Paciente , Doadores de Tecidos , Morte Encefálica , Doenças Cardiovasculares/terapia , Simulação por Computador , Currículo , Doenças do Sistema Endócrino/terapia , Humanos , Pneumopatias/terapia , Estudos Multicêntricos como Assunto
14.
Phys Rev Lett ; 107(13): 135003, 2011 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-22026863

RESUMO

A first-principles study of diffusion in a strongly coupled one-component plasma in a magnetic field B is presented. As in a weakly coupled plasma, the diffusion coefficient perpendicular to the field exhibits a Bohm-like 1/B behavior in the strong-field limit but its overall scaling is substantially different. The diffusion coefficient parallel to the field is strongly affected by the field as well and also approaches a 1/B scaling, in striking contrast to earlier predictions.

15.
Eur J Vasc Endovasc Surg ; 42(5): 684-8, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21820336

RESUMO

INTRODUCTION: Supracondylar humerus fractures in childhood present with a pulseless but well-perfused hand in 2.6% of cases and with limb-threatening ischaemia in <1%. Conservative treatment is widely used in non-limb-threatening ischaemia, in particular if the child is very young (<2.5 years). It has been sufficiently proven that conservative treatment may retard growth. The aim of our study was to determine long-term patency rates after surgical reconstruction and growth impairment, if any, after surgical vascular reconstruction. PATIENTS AND METHODS: Between June 1990 and June 2004, 12 children (mean age 6.6 years, eight boys and four girls) with supracondylar fracture with vascular lesions underwent surgical reconstruction at the Department of Vascular Surgery at the University Hospital, Graz. Patient files were reviewed retrospectively. All patients were recalled for physical (forearm length and volume) and ultrasonographic examinations (forearm blood flow) in 2005 and for ultrasonographic examinations (reconstructed vascular area) in 2011, with a final mean follow-up time of 14.0 years (range 6.8-20.9 years). RESULTS: Twelve patients, 10 of whom had undergone growth measurements in 2005, were available for the latter examination. All were doing well, with patent vascular reconstructions. Seven reconstructed brachial arteries were enlarged, two of which with intramural calcifications, four did not show abnormalities and one presented with 45% thinning. There were no differences between affected and healthy forearms concerning volume, length and blood flow. CONCLUSIONS: Our data emphasise that surgical reconstruction is effective in terms of blood supply and growth. In cases with interposition of greater saphenous vein or venous patch plasty, we found a high risk for development of enlargements. We suggest that these patients be followed periodically, with ultrasound studies, to detect aneurysms and/or thrombotic changes as early as possible.


Assuntos
Artéria Braquial , Fraturas do Úmero/complicações , Fraturas do Úmero/cirurgia , Doença Arterial Periférica/cirurgia , Artéria Ulnar , Criança , Pré-Escolar , Feminino , Seguimentos , Humanos , Fraturas do Úmero/patologia , Masculino , Doença Arterial Periférica/etiologia , Doença Arterial Periférica/patologia , Estudos Retrospectivos , Fatores de Tempo , Resultado do Tratamento , Grau de Desobstrução Vascular
16.
Science ; 372(6537)2021 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-33795430

RESUMO

Hallucinations, a central symptom of psychotic disorders, are attributed to excessive dopamine in the brain. However, the neural circuit mechanisms by which dopamine produces hallucinations remain elusive, largely because hallucinations have been challenging to study in model organisms. We developed a task to quantify hallucination-like perception in mice. Hallucination-like percepts, defined as high-confidence false detections, increased after hallucination-related manipulations in mice and correlated with self-reported hallucinations in humans. Hallucination-like percepts were preceded by elevated striatal dopamine levels, could be induced by optogenetic stimulation of mesostriatal dopamine neurons, and could be reversed by the antipsychotic drug haloperidol. These findings reveal a causal role for dopamine-dependent striatal circuits in hallucination-like perception and open new avenues to develop circuit-based treatments for psychotic disorders.


Assuntos
Corpo Estriado/metabolismo , Dopamina/metabolismo , Alucinações/fisiopatologia , Percepção , Animais , Percepção Auditiva , Feminino , Alucinações/psicologia , Haloperidol/farmacologia , Humanos , Ketamina/farmacologia , Masculino , Camundongos Endogâmicos C57BL , Modelos Neurológicos , Transtornos Psicóticos/fisiopatologia , Ratos , Recompensa , Estriado Ventral/metabolismo
17.
Phys Rev Lett ; 105(5): 055002, 2010 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-20867926

RESUMO

The existence of plasma oscillations at multiples of the magnetoplasmon frequency in a strongly coupled two-dimensional magnetized Yukawa plasma is reported, based on extensive molecular dynamics simulations. These modes are the analogues of Bernstein modes which are renormalized by strong interparticle correlations. Their properties are theoretically explained by a dielectric function incorporating the combined effect of a magnetic field, strong correlations and finite temperature.

18.
Nature ; 425(6961): 934-7, 2003 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-14586462

RESUMO

Recent measurements of stellar orbits provide compelling evidence that the compact radio source Sagittarius A* (refs 4, 5) at the Galactic Centre is a 3.6-million-solar-mass black hole. Sgr A* is remarkably faint in all wavebands other than the radio region, however, which challenges current theories of matter accretion and radiation surrounding black holes. The black hole's rotation rate is not known, and therefore neither is the structure of space-time around it. Here we report high-resolution infrared observations of Sgr A* that reveal 'quiescent' emission and several flares. The infrared emission originates from within a few milliarcseconds of the black hole, and traces very energetic electrons or moderately hot gas within the innermost accretion region. Two flares exhibit a 17-minute quasi-periodic variability. If the periodicity arises from relativistic modulation of orbiting gas, the emission must come from just outside the event horizon, and the black hole must be rotating at about half of the maximum possible rate.

19.
Neotrop Entomol ; 49(6): 916-922, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32700190

RESUMO

Phasmatodea (Arthropoda, Insecta) comprises phytophagous insects, popularly known as stick bugs because most of them resemble dry branches. Currently, more than 3000 species are known, the majority of which can be found in tropical regions of the world. In Brazil, it is estimated that there are approximately 200 species, but these numbers may not truly reflect the group's richness. A high degree of intraspecific polymorphism, a low number of specimens sampled, a shortage of specialized literature, and having only a small number of experts have amplified the difficulties in studying this order. Therefore, this study aims to present a historical survey of the Phasmatodea studies that have been conducted in Brazil thus far, indicating gaps in knowledge and discussing perspectives to expand understanding within this group. Furthermore, to the best our knowledge, the molecular characterization of the cytochrome oxidase subunit I gene of mitochondrial DNA of two species of phasmids found in Brazil, Cladomorphus phyllinus Gray, 1835, and Pseudophasma missionum Piza, 1981, is presented for the first time. In addition, this study records for the first time the occurrence of P. missionum in Brazilian territory.


Assuntos
Neópteros/classificação , Filogenia , Animais , Brasil , DNA Mitocondrial
20.
Phys Rev Lett ; 103(19): 195001, 2009 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-20365932

RESUMO

There have recently been many predictions of "superdiffusion" in two-dimensional strongly coupled Yukawa systems, both by computer simulations and in dusty plasma experiments, with substantially varying diffusion exponents. Here we show that the results crucially depend on the strength of dissipation and the time instant of the measurement. For sufficiently large friction even subdiffusion is possible. However, there are strong indications that, in the long-time limit, anomalous diffusion vanishes and the system returns to normal diffusion, for dissipative as well as for frictionless systems.

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