Electronic cigarettes: "wolves in sheep's clothing".

OBJECTIVE: To provide cutting-edge information on the impact and risks of using Electronic Nicotine Delivery Systems (ENDS) by children and adolescents, based on the latest evidence published in the literature. DATA SOURCE: A comprehensive search was carried out on PubMed, using the expressions ''electronic cigarettes'' OR ''electronic nicotine delivery systems" OR "vaping" AND ''adolescent'' AND "risks" AND ''acute lung injury'. All retrieved articles had their titles and abstracts read to identify and fully read the papers reporting the most recent evidence on each subject. SUMMARY OF FINDINGS: The use of ENDS has alarmingly increased in Brazil and around the world. The possibility of customizing use, the choice of flavors and nicotine content, and the general notion that these devices are harmless when compared to conventional cigarettes are some of the factors responsible for this increase. Numerous scientific studies have proven that electronic cigarettes have serious consequences for the respiratory system, such as EVALI (E-cigarette or Vaping-Associated Lung Injury) and difficult-to-control asthma, as well as harmful effects on the neurological, cardiovascular, gastrointestinal, and immunological systems. High concentrations of nicotine make many young people addicted to this substance. In Brazil, commercialization, import, and advertising are prohibited. The viable interventions to address the use of these devices in children and adolescents are prevention and behavioral counseling. CONCLUSION: There is clear scientific evidence that these devices pose a risk to the physical and mental health of children and adolescents.

Coconut shell-based biochars produced by an innovative thermochemical process for obtaining improved lignocellulose-based adsorbents.

The urgent need for a simple and cost-effective thermochemical process to produce biochar has prompted this study. The aim was to develop a straightforward thermochemical process under O2-limited conditions for the production of coconut-based biochar (CBB) and to assess its ability to remove methylene blue (MB) through adsorption, comparing it with CBB produced by slow pyrolysis. CBBs were obtained under different atmospheric conditions (O2-limited, muffle furnace biochar (MFB); and inert, pyrolytic reactor biochar (PRB)), at 350, 500, and 700 °C, and for 30 and 90'. MFB and PRB were characterized using FTIR, RAMAN, SEM, EDS, and XRD analyses. Adsorption tests were conducted using 1.0 g L-1 of MFB and PRB, 10 mg L-1 of MB at 25 °C for 48 h. Characterization revealed that atmospheric conditions significantly influenced the yield and structural features of the materials. PRB exhibited higher yields and larger cavities than MFB, but quite similar spectral features. Adsorption tests indicated that MFB and PRB had qt values of 33.1 and 9.2 mg g-1, respectively, which were obtained at 700 °C and 90', and 700 °C and 30', respectively. This alternative method produced an innovative and promising lignocellulose-based material with great potential to be used as a biosorbent.

Is estradiol valerate an alternative to estradiol benzoate in promoting the synchronization of ovulation and timed artificial insemination in suckled Bos indicus beef cows?

The objective of the present study was to evaluate the effect of estradiol valerate administered at the beginning of the ovulation synchronization protocol on the pregnancy rate of Bos indicus cows. In the experiments, the following products from MSD, Sao Paulo, Brazil were used: estradiol valerate (EV), estradiol benzoate (EB), intravaginal progesterone device (P4), estradiol cypionate (EC), equine chorionic gonadotropin (eCG) and cloprostenol (PGF). In Experiment 1, Bos indicus cows (n=899) with a body condition score (BCS) of 2.76 ± 0.01 were included in a 3 (device) × 2 (protocol: 5 mg of EV or 2 mg of EB) factorial design. There were three types of P4 devices: a new device (New), a device previously used for 9 days (1×), and a device previously used for 18 days (2×). Nine days later (D9), the P4 device was removed, and cows received 300 IU of eCG. In addition, cows in the EB group received 1 mg of EC and 265 µg of PGF. Timed artificial insemination (TAI) was performed 48 h after P4 device removal in the EB group (TAI48) and 54 h after P4 device removal in the EV group (TAI54). In Experiment 2, Bos indicus cows (n=434) with a BCS of 2.62 ± 0.01 received a new P4 device or one previously used for 9 days and 5 mg of EV. On D9, all cows received 300 IU of eCG, and the P4 devices were removed and distributed in TAI48 and TAI54 cows. In Experiment 3, Bos indicus cows (n=429) with a BCS of 2.80 ± 0.01 were divided into the control and EV/EC groups. All cows received a P4 device. In addition, cows in the control group received 2 mg of EB, and cows in the EV/EC group received 5 mg of EV on D0. On D9, all cows received 1 mg of EC and 300 IU of eCG, and the P4 devices were removed. Cows in the control group also received 265 µg of PGF. All cows were inseminated 48 h after the removal of the P4 device. In Experiment 1, there was no effect of the interaction between protocol and P4 device on the occurrence of estrus (P=0.45) or on the pregnancy per artificial insemination ratio (P/AI; P=0.30). In addition, the occurrence of estrus and P/AI were not different between in the two estradiol groups (P=0.12 and P=0.82) and across the types of intravaginal P4 device (P=0.91 and P=0.47). In Experiment 2, the pregnancy rate was lower (tendency) in TAI48 cows (P=0.07). In Experiment 3, the estrus rate (P=0.12) and P/AI (P=0.56) were similar between the experimental groups. In summary, protocols using estradiol valerate without exogenous ovulation induction require adjustments in the timing of AI from 48 to 54 h after P4 device removal. However, a combination of estradiol valerate at the beginning of the protocol and estradiol cypionate nine days later successfully induced ovulation in Bos indicus cows inseminated 48 h after P4 device removal.

Supplementation with long-acting injectable progesterone 3 days after TAI impaired luteal function in buffaloes.

Three experiments were conducted to evaluate the effects of long-acting injectable progesterone (iP4) in buffalo cows. In Experiment 1, ovariectomized buffaloes received 300 mg (iP300) or 600 mg (iP600) of iP4, and serum P4 concentrations were evaluated. In experiment 2, three groups were compared: control or administration of 300 mg of iP4 3 (iP4-D3) or 6 days (iP4-D6) after timed artificial insemination (TAI). On day 16, reproductive tract was recovered for conceptus, endometrium, and corpus luteum (CL) analysis. In experiment 3, pregnancy per AI (P/TAI) and proportion of pregnancy losses were evaluated after administration of 300 mg of iP4 3 (iP4-D3) or 6 days (iP4-D6) after TAI in lactating buffaloes. In experiment 1, serum P4 concentrations remained over 1 ng/mL for ~ 3 days in both groups. The 300 mg dose was used in subsequent experiments. In experiment 2, CL weight and endometrial glands density were decreased, and conceptus length was increased in iP4-D3 compared to control and to iP4-D6 (P < 0.05). Transcript abundance of Prostaglandin F Receptor (FP) and ISG15 in CL and of ISG15 and MX1 in endometrium was greater in iP4-D3 when compared to control and to iP4-D6 (P < 0.05). In experiment 3, there was no difference among experimental groups for P/TAI at D30 and pregnancy losses (P > 0.1); however, iP4-D3 presented a lower P/TAI at day 60 (41.7%) when compared to control (56.8%) and iP4-D6 (57.7%; P = 0.07). In conclusion, administration iP4 at 3 days after TAI affects CL development and consequently decreases final pregnancy outcome in buffaloes.

Simulation-based bronchoscopy training: Randomized trial comparing worked example to video introduction.

INTRODUCTION: Learning the complex skill of bronchoscopy involves the integration of cognitive domains and motor skills. The development of simulators has opened up new possibilities in bronchoscopy training. This study aimed at evaluating how effective the modeling example methodology is in training this skill and assessed its effect on cognitive load in learning. METHODS: Forty-seven medical students participating in a simulator-based bronchoscopy training program were randomly allocated to a control group, receiving a video lesson, and the modeling example group. They were evaluated by the simulator's metrics at different time points: pre-, posttest, and 15 days and 12 months after training. Cognitive load was assessed with the modified Paas scale. RESULTS: Simulation-based training was effective for both groups, based on simulator metrics (p < .05). The modeling example group outperformed the control group in all measures at posttest and after 15 days (p < .001). After 12 months, there was a decline in skill in both groups, but the modeling example group performed better (p < .001). Simulation-based training reduced cognitive load, more strongly so in the modeling example group (p < .001). CONCLUSION: The modeling example group showed substantial benefits over the control group, both in reducing the cognitive load in learning and in retaining knowledge and skill after 15 days and 12 months.

Self-regulated learning e ensino médico: revisão de literatura / Self-regulated learning and medical education: a literature review

Resumo: Introdução: A aprendizagem autorregulada (self-regulated learning - SRL) é o processo ativo que o aluno realiza para atingir seus objetivos de aprendizagem. No ensino médico, pelo fato de o ambiente clínico ser propício para o desenvolvimento da SRL, há potencial benefício na aplicação dessa ferramenta no processo de ensino-aprendizado, embora as diferenças em seus cenários de aplicação exijam uma análise mais aprofundada. Objetivo: Este artigo apresenta uma revisão da literatura sobre o histórico do desenvolvimento da SRL, sua aplicabilidade e avaliação em estudantes de Medicina por meio de escala validada, além dos fatores que a influenciam, como métodos de ensino e questões demográficas e socioculturais. Método: Realizou-se uma busca com o descritor self-regulated learning nas plataformas PubMed e SciELO e na revista Medical Education Online para artigos em inglês publicados entre 2010 e 2021. Resultado: A busca nas bases de dados resultou em 198 artigos, dos quais foram selecionados 100 para a análise crítica. Desses 100 artigos, selecionaram-se 31 que preenchiam os critérios desta revisão. Conclusão: A SRL é um conceito contemporâneo considerado pilar no processo educacional. Trata-se de ferramenta de grande valor em psicologia educacional. A aplicabilidade da SRL no contexto do ensino médico demonstra-se efetiva e traz consigo especificidades sobre a autorregulação do estudante de Medicina. Contudo, são necessários novos estudos acerca do tema, de modo a permitir o desenvolvimento de métodos instrucionais eficazes com sua utilização.

Abstract: Introduction: Self-regulated learning (SRL) is the active process that students perform to achieve their learning goals. In medical education, the development of SRL is favoured by the clinical environment, hence there is potential benefit in applying this tool in the teaching-learning process, although the differences in its application scenarios require deeper analysis. Objective: The aim of this article is to present a literature review on the development of SRL, its applicability and evaluation in medical students using a validated scale, and the factors that influence it, such as teaching methods and demographic and sociocultural issues. Method: A search was performed on the Pub-med and Scielo platforms and the online Medical Education Journal for articles in English published between 2010 and 2021 using the descriptors "Self-regulated learning". Results: The database search resulted in 198 articles, of which 100 were selected for critical analysis. Of these, 31 articles were selected based on meeting the criteria of this review. Conclusions: SRL is a contemporary educational concept and considered a pillar in the educational process. It is a valuable tool in educational psychology. Its applicability in the context of medical education proves to be effective and brings with it specificities in relation to the self-regulation of medical students. However, further studies on the subject are necessary to allow for the development of effective instructional methods to support its use.

Bronchoscopy simulation training in the post-pandemic world.

Bronchoscopy is an important procedure to examine the airways. It is traditionally taught by having trainees perform it in humans. This carries risks, albeit rarely, and causes stress to trainees. The objective of this study was to review bronchoscopy simulators, as well as their use in and impact on medical education, presenting perspectives on the use of simulators in the post-pandemic world. This review was based on articles published in English in 2000-2021 and retrieved from any of the following databases: MEDLINE (PubMed), Embase, SciELO, and Google Scholar. Bronchoscopy simulators have improved markedly over time, allowing the teaching/learning process to take place in a risk-free environment. Bronchoscopy simulation training is an interesting option for the evaluation of the airways, especially in the coming years, with the COVID-19 pandemic highlighting the need for continuing medical education.

Bronchoscopy simulation training in the post-pandemic world / Treinamento com simuladores de broncoscopia no mundo pós-pandemia

ABSTRACT Bronchoscopy is an important procedure to examine the airways. It is traditionally taught by having trainees perform it in humans. This carries risks, albeit rarely, and causes stress to trainees. The objective of this study was to review bronchoscopy simulators, as well as their use in and impact on medical education, presenting perspectives on the use of simulators in the post-pandemic world. This review was based on articles published in English in 2000-2021 and retrieved from any of the following databases: MEDLINE (PubMed), Embase, SciELO, and Google Scholar. Bronchoscopy simulators have improved markedly over time, allowing the teaching/learning process to take place in a risk-free environment. Bronchoscopy simulation training is an interesting option for the evaluation of the airways, especially in the coming years, with the COVID-19 pandemic highlighting the need for continuing medical education.

RESUMO A broncoscopia é um procedimento importante para examinar as vias aéreas. O treinamento tradicional consiste em realizar o procedimento em humanos. Isso traz riscos, embora apenas raramente, e causa estresse nos broncoscopistas em formação. O objetivo deste estudo foi realizar uma revisão da literatura a respeito de simuladores de broncoscopia e seu uso e impacto na educação médica, apresentando perspectivas acerca do uso de simuladores no mundo pós-pandemia. A revisão baseou-se em artigos publicados em inglês em 2000-2021 e recuperados a partir de buscas realizadas nos seguintes bancos de dados: MEDLINE (PubMed), Embase, SciELO e Google Acadêmico. Os simuladores de broncoscopia melhoraram muito ao longo dos anos, permitindo que o processo de ensino e aprendizagem ocorra em um ambiente livre de riscos. O treinamento com simuladores de broncoscopia é uma opção interessante para a avaliação das vias aéreas, principalmente nos próximos anos, já que a pandemia de COVID-19 ressaltou a necessidade de educação médica continuada.

Mild Steel GMA Welds Microstructural Analysis and Estimation Using Sensor Fusion and Neural Network Modeling.

This study aims at evaluating the efficiency of sensor fusion, based on neural networks, to estimate the microstructural characteristics of both the weld bead and base material in GMAW processes. The weld beads of AWS ER70S-6 wire were deposited on SAE 1020 steel plates varying welding voltage, welding speed, and wire-feed speed. The thermal behavior of the material during the process execution was analyzed using thermographic information gathered by an infrared camera. The microstructure was characterized by optical (confocal) microscopy, scanning electron microscopy, and X-ray Diffraction tests. Finally, models for estimating the weld bead microstructure were developed by fusing all the information through a neural network modeling approach. A R value of 0.99472 was observed for modelling all zones of microstructure in the same ANN using Bayesian Regularization with 17 and 15 neurons in the first and second hidden layers, respectively, with 4 training runs (which was the lowest R value among all tested configurations). The results obtained prove that RNAs can be used to assist the project of welded joints as they make it possible to estimate the extension of HAZ.

Anti-Mullerian hormone and its relationship to ovulation response and fertility in timed AI Bos indicus heifers.

This study evaluated the association between plasma anti-Mullerian hormone (AMH) concentration and fertility in Nelore (Bos indicus) heifers submitted to timed artificial insemination (TAI). At the onset of the synchronization protocol, heifers (n = 289) received a subcutaneous P4 ear implant (3 mg) and 2 mg of oestradiol benzoate. Eight days later, the P4 implant was removed and 0.5 mg of oestradiol cypionate, prostaglandin (0.265 mg, i.m.) and equine chorionic gonadotropin (300 UI, i.m.) was administered, and TAI was performed 48 hr after ear implant removal. Ovarian ultrasound evaluations were performed to measure number of ovarian follicles, dominant follicle size and ovulation response. Pregnancy diagnosis was performed by ultrasound 30 days after AI. Heifers with greater circulating AMH had more antral follicles, a smaller dominant follicle near timed ovulation and lower ovulation response to the timed AI protocol compared to heifers with lower circulating AMH. Although AMH and pregnancy outcome had a quadratic-shaped pattern, AMH was not significantly associated with fertility. In conclusion, heifers with lower AMH had larger follicles towards the end of the synchronization protocol and greater ovulation responses, whereas greater circulating AMH was unrelated to conception success.

Epiglotite na era pós-vacinal ao Haemophilus influenzae tipo B / Epiglottitis in the post Haemophilus influenzae type B vaccine era

A epiglotite, conhecida recentemente como supraglotite, é uma infecção grave da epiglote e estruturas supraglóticas, com consequente obstrução da via aérea superior e risco iminente de morte. Trata-se de emergência médica, e a via aérea do paciente deve ser garantida o mais breve possível. Com o desenvolvimento e introdução da vacinação contra o Haemophilus influenzae tipo B (Hib), houve queda expressiva de sua incidência e mortalidade na faixa etária pediátrica, principalmente em crianças menores de cinco anos, porém, tal redução não foi tão significativa em adultos. A doença passou a ser mais comum em crianças acima de cinco anos e na faixa etária adulta, e agentes como Streptococcus e Staphylococcus tornaram-se os principais responsáveis. Embora rara, ela ainda não foi eliminada, fazendo-se necessário o seu rápido reconhecimento e tratamento, a fim de evitar mortalidade. (AU)

Epiglottitis, recently known as supraglottitis, is a severe infection of the epiglottis and supraglottic structures, leading to upper airway obstruction and imminent risk of death. It is considered a medical emergency and the patient's airway must be cleared as soon as possible. With the development and introduction of the vaccination against Haemophilus influenzae type B (Hib), there has been a significant decline in its incidence and mortality in the pediatric age range, especially in children younger than five years old, yet not so much in adults. The disease has become more common in children older than five years old and in adults, with Streptococcus and Staphylococcus being the main responsible pathogens. Although it is a rare condition, it has not yet been eradicated, making its fast recognition and treatment necessary to decrease the chance of mortality. (AU)

Biofeedback in dysphonia - progress and challenges / Biofeedback em disfonia - progresso e desafios

Abstract Introduction There is evidence that all the complex machinery involved in speech acts along with the auditory system, and their adjustments can be altered. Objective To present the evidence of biofeedback application for treatment of vocal disorders, emphasizing the muscle tension dysphonia. Methods A systematic review was conducted in Scielo, Lilacs, PubMed and Web of Sciences databases, using the combination of descriptors, and admitting as inclusion criteria: articles published in journals with editorial committee, reporting cases or experimental or quasi-experimental research on the use of biofeedback in real time as additional source of treatment monitoring of muscle tension dysphonia or for vocal training. Results Thirty-three articles were identified in databases, and seven were included in the qualitative synthesis. The beginning of electromyographic biofeedback studies applied to speech therapy were promising and pointed to a new method that enabled good results in muscle tension dysphonia. Nonetheless, the discussion of the results lacked physiological evidence that could serve as their basis. The search for such explanations has become a challenge for speech therapists, and determined two research lines: one dedicated to the improvement of the electromyographic biofeedback methodology for voice disorders, to reduce confounding variables, and the other dedicated to the research of neural processes involved in changing the muscle engram of normal and dysphonic patients. Conclusion There is evidence that the electromyographic biofeedback promotes changes in the neural networks responsible for speech, and can change behavior for vocal emissions with quality.

Resumo Introdução Há evidências de que o complexo aparato envolvido no ato da fala, juntamente com o sistema auditivo, e seus ajustes podem ser alterados. Objetivo Apresentar evidências da aplicação de biofeedback (biorretroalimentação) para tratamento de distúrbios vocais, enfatizar a disfonia de tensão muscular. Método Realizou-se uma revisão sistemática nas bases de dados de Scielo, Lilacs, PubMed e Web of Sciences, utilizando a combinação de descritores e admitindo como critérios de inclusão: artigos publicados em revistas com comitê editorial, relatos de casos ou pesquisas experimentais ou quase experimentais sobre o uso debiofeedbackem tempo real como fonte adicional de monitoração de tratamento de disfonia de tensão muscular ou para treinamento vocal. Resultados Trinta e três artigos foram identificados em bases de dados, e sete foram incluídos na síntese qualitativa. O início dos estudos de biofeedbackeletromiográficos aplicados à terapia fonoaudiológica foram promissores e indicaram um novo método que permitiu bons resultados na disfonia de tensão muscular. No entanto, a discussão dos resultados carecia de evidências fisiológicas que pudessem servir de base. A busca por tais explicações tornou-se um desafio para os fonoaudiólogos e determinou duas linhas de pesquisa: uma dedicada à melhoria da metodologia de biofeedbackeletromiográfico para distúrbios da voz, para reduzir as variáveis de confusão e outra dedicada à pesquisa de processos neurais envolvidos na alteração do engrama muscular de pacientes normais e disfônicos. Conclusão Há evidências de que o biofeedback eletromiográfico promove mudanças nas redes neurais responsáveis pela fala e pode mudar o comportamento para emissões vocais com qualidade.

Long-Term Effects of Anterior Thalamic Nucleus Deep Brain Stimulation on Spatial Learning in the Pilocarpine Model of Temporal Lobe Epilepsy.

INTRODUCTION AND OBJECTIVES: Cognitive impairment is a significant comorbidity of temporal lobe epilepsy that is associated with extensive hippocampal cell loss. Deep brain stimulation (DBS) of the anterior thalamic nucleus (ANT) has been used for the treatment of refractory partial seizures. In the pilocarpine model of epilepsy, ANT DBS applied during status epilepticus (SE) reduces hippocampal inflammation and apoptosis. When given to chronic epileptic animals it reduces hippocampal excitability and seizure frequency. Here, we tested whether ANT DBS delivered during SE and the silent phase of the pilocarpine model would reduce cognitive impairment when animals became chronically epileptic. MATERIALS AND METHODS: SE was induced by a systemic pilocarpine injection (320 mg/kg). Immediately after SE onset, rats were assigned to receive DBS during the first six hours of SE (n = 8; DBSa group) or during SE + the silent period (i.e., 6 h/day until the animals developed the first spontaneous recurrent seizure; n = 10; DBSs group). Four months following SE, animals underwent water maze testing and histological evaluation. Nonstimulated chronic epileptic animals (n = 13; PCTL group) and age-matched naïve rats (n = 11, CTL group) were used as controls. Results were analyzed by repeated-measures analyses of variance (RM_ANOVA) and one-way ANOVAs, followed by Newman-Keuls post hoc tests. RESULTS: Although all groups learned the spatial task, epileptic animals with or without DBS spent significantly less time in the platform quadrant, denoting a spatial memory deficit (p < 0.02). Despite these negative behavioral results, we found that animals given DBS had a significantly higher number of cells in the CA1 region and dentate gyrus. Mossy fiber sprouting was similar among all epileptic groups. CONCLUSIONS: Despite lesser hippocampal neuronal loss, ANT DBS delivered either during SE or during SE and the silent phase of the pilocarpine model did not mitigate memory deficits in chronic epileptic rats.

Biofeedback in dysphonia - progress and challenges.

INTRODUCTION: There is evidence that all the complex machinery involved in speech acts along with the auditory system, and their adjustments can be altered. OBJECTIVE: To present the evidence of biofeedback application for treatment of vocal disorders, emphasizing the muscle tension dysphonia. METHODS: A systematic review was conducted in Scielo, Lilacs, PubMed and Web of Sciences databases, using the combination of descriptors, and admitting as inclusion criteria: articles published in journals with editorial committee, reporting cases or experimental or quasi-experimental research on the use of biofeedback in real time as additional source of treatment monitoring of muscle tension dysphonia or for vocal training. RESULTS: Thirty-three articles were identified in databases, and seven were included in the qualitative synthesis. The beginning of electromyographic biofeedback studies applied to speech therapy were promising and pointed to a new method that enabled good results in muscle tension dysphonia. Nonetheless, the discussion of the results lacked physiological evidence that could serve as their basis. The search for such explanations has become a challenge for speech therapists, and determined two research lines: one dedicated to the improvement of the electromyographic biofeedback methodology for voice disorders, to reduce confounding variables, and the other dedicated to the research of neural processes involved in changing the muscle engram of normal and dysphonic patients. CONCLUSION: There is evidence that the electromyographic biofeedback promotes changes in the neural networks responsible for speech, and can change behavior for vocal emissions with quality.

Timed artificial insemination: current challenges and recent advances in reproductive efficiency in beef and dairy herds in Brazil

Beef and dairy productivity depends directly on the reproductive efficiency and genetic gain of the herd, which can be related to the appropriate use of biotechnologies, such as timed artificial insemination (TAI). When considering variations in synchronizations protocols, longer or shorter periods of progesterone (P4) device treatment could provide benefits to fertility. However, our studies evidenced that protocols with six (J-synch), seven, eight and nine days of P4 device treatment had similar pregnancy per AI (P/AI). In cyclic cows, the early prostaglandin (PGF) administration, moving from the day of P4 device removal to two days earlier, which results in four handlings of cows, or the administration of one extra dose of PGF at the onset of the protocol and a single PGF on the day of P4 device removal (three handlings) are both efficient to induce early luteolysis, reducing serum P4 concentrations and, therefore, stimulating LH pulsatility, which improves growth of the dominant follicle and results greater P/AI when compared with protocols with the administration of PGF only on the day of P4 device removal. Resynchronization is another valuable tool to reduce the interval between AI. Traditional Resynch is initiated at pregnancy diagnosis (28 to 32 days after TAI) and the interval between AI is around 40 days; Resynch 22 and Resynch 14 respectively initiates 22 and 14 days after the previous AI in all cows (unknown status of pregnancy) and reduces the interval between AI to 32 and 24 days. The novelty about Resynch 14 is the need to use of Doppler ultrasonography for pregnancy diagnosis [evaluation of corpus luteum (CL) vascularization].(AU)

Timed artificial insemination: current challenges and recent advances in reproductive efficiency in beef and dairy herds in Brazil

Beef and dairy productivity depends directly on the reproductive efficiency and genetic gain of the herd, which can be related to the appropriate use of biotechnologies, such as timed artificial insemination (TAI). When considering variations in synchronizations protocols, longer or shorter periods of progesterone (P4) device treatment could provide benefits to fertility. However, our studies evidenced that protocols with six (J-synch), seven, eight and nine days of P4 device treatment had similar pregnancy per AI (P/AI). In cyclic cows, the early prostaglandin (PGF) administration, moving from the day of P4 device removal to two days earlier, which results in four handlings of cows, or the administration of one extra dose of PGF at the onset of the protocol and a single PGF on the day of P4 device removal (three handlings) are both efficient to induce early luteolysis, reducing serum P4 concentrations and, therefore, stimulating LH pulsatility, which improves growth of the dominant follicle and results greater P/AI when compared with protocols with the administration of PGF only on the day of P4 device removal. Resynchronization is another valuable tool to reduce the interval between AI. Traditional Resynch is initiated at pregnancy diagnosis (28 to 32 days after TAI) and the interval between AI is around 40 days; Resynch 22 and Resynch 14 respectively initiates 22 and 14 days after the previous AI in all cows (unknown status of pregnancy) and reduces the interval between AI to 32 and 24 days. The novelty about Resynch 14 is the need to use of Doppler ultrasonography for pregnancy diagnosis [evaluation of corpus luteum (CL) vascularization].

Intrinsic and extrinsic factors that influence ovarian environment and efficiency of reproduction in cattle

The emergent concepts on ovary environment,reproductive physiology and the development ofpharmacology are constantly supporting the advance ofassisted reproduction. Within the last years, thebiotechnics related to the synchronization of folliculardevelopment and the manipulation of bovine estruscycle have progressed rapidly and consistently. Thecombined use of timed-artificial insemination (TAI),superovulation (SOV), ovum pick up (OPU), in vitroembryo production (IVEP) and timed-embryo transfer(TET) has a great potential to improve reproductiveoutcomes and disseminate selected genetics,diminishing the interval of generations and improvingherds genetic gain. However, several factors canpotentially affect the efficiency of these procedures. Theknowledge of the particularities of the genetic groups,follicular growth manipulation, follicular populationpredictors, and metabolic and environmental aspectsthat interfere with ovarian environment and,consequently, oocyte quantity and quality is crucial tooptimize the reproductive programs. This review aimsto elucidate some factors that affect the ovarianenvironment and must be well known in order toimprove the efficiency of reproduction in cattle.

Ribosomal DNA nanoprobes studied by Fourier transform infrared spectroscopy.

Paracoccidioides brasiliensis (P. brasiliensis) is a thermo-dimorphic fungus that causes paracoccidioidomycosis. Brazil epidemiological data shows that endemic areas are the subtropical regions, especially where agricultural activities predominate such as the Southeast, South, and Midwest. There are several tests to diagnose paracoccidioidomycosis, but they have many limitations such as low sensitivity, high cost, and a cross-reacting problem. In this work, gold nanoprobes were used to identify P. brasiliensis as an alternative diagnostic technique, which is easier to apply, costs less, and has great potential for application. The specific Ribosomal sequence of P. brasiliensis DNA was amplified and used to design the nanoprobes using a thiol-modified oligonucleotide. The results of positive and negative tests were done by UV-visible and Fourier Transform Infrared (FT-IR) measurements. The deconvolution of FT-IR sample spectra showed differences in the vibrational modes from the hydrogen bridge NHN and NHO bands that form the double helix DNA for samples matching the DNA sequence of nanoprobes that could be used to classify the samples.

Surface enhancement Raman scattering of tautomeric thiobarbituric acid. Natural bond orbitals and B3LYP/6-311+G (d, p) assignments of the Fourier Infrared and Fourier Raman Spectra.

Surface enhancement Raman scattering (SERS) of two tautomer of thiobarbituric acid was obtained using silver and gold nanoparticles. Large band enhancement in the region of the ν(C=S), ν(C=C), δ(CH2), and δ(CNH) vibrational modes was found. Natural bond analysis of the tautomer species revealed expressive values of charge transfer, principally from lone pair electron orbitals of the S, N, and O atoms. Complete vibrational assignment was done for the two tautomers using the B3LYP/6-311+G (d, p) procedure, band deconvolution analysis, and from a rigorous interpretation of the normal modes matrix. The calculated spectra agree well with the experimental ones.

Fatores associados à produção e à sobrevivência embrionária em programas de superovulação e transferência de embriões em fêmeas da raça Holandesa em clima tropical / Factors associated to embryo production and survival in superovulation programs and embryo transfer in Holstein females raised in tropical climate

A alta variabilidade na resposta aos tratamentos superovulatórios e na produção de embriões tem sido relacionada a causas multifatoriais. Além disso, são restritas as informações que relacionam fatores correlatos ao embrião à concepção. Dessa forma, o objetivo do presente estudo foi avaliar a influência de variáveis relacionadas às doadoras (categoria animal e época do ano de produção do embrião) na eficiência de programas de superovulação (SOV), assim como na eficiência reprodutiva de receptoras em programas de transferência de embrião. Foram avaliados dados de 1.562 protocolos de SOV (609 em vacas em lactação e 953 em novilhas da raça Holandesa) e 4.076 transferências de embrião (receptoras Holandesas em lactação). A taxa de SOV (número de doadoras com dois ou mais CL) foi semelhante entre novilhas e vacas em lactação (89,7 vs. 91,9%, respectivamente; P = 0,26). A época do ano, também, não influenciou a taxa de SOV (época quente = 89,3% vs. época não quente = 92,2%; P = 0,09). Doadoras lactantes apresentaram maior número de CL (10,6 ± 0,6 vs. 7,5 ± 0,4; P < 0,0001), de estruturas recuperadas (7,6 ± 0,6 vs. 4,6 ± 0,4; P < 0,0001) e taxa de recuperação (77,6 vs. 58,7%; P < 0,0001) que novilhas. [...] Em conclusão, apesar das doadoras em lactação apresentarem maior resposta superovulatória, as novilhas apresentaram semelhante número de embriões viáveis, porém maior taxa de embriões viáveis. A resposta ao tratamento superovulatório e a produção de embriões foram inferiores durante a época quente do ano. Embriões originados de doadoras Holandesas lactantes apresentaram maior taxa de concepção aos 31 e aos 45 dias de gestação do que embriões originados de novilhas. Apesar da época do ano não influenciar na taxa de concepção e na perda gestacional, verificou-se relação negativa da temperatura máxima entre o estro e a TE na taxa de concepção.

The high variability in the response to superovulatory treatments and embryo production has been related to multifactorial causes. Furthermore, there are restricted data that correlates factors related to the embryo to the conception. Thus, the objective of the present study was to evaluate the influence of variables related to donors (animal type and season of embryo production) in the efficiency of superovulation (SOV) programs and reproductive performance of dairy cows submitted to embryo transfer. We evaluated data from 1,562 SOV protocols (609 in lactating Holstein cows and 953 in heifers) and 4,076 embryo transfers (lactating Holstein recipient). The SOV rate (number of donor with two or more CL) was similar among lactating cows and heifers (89.7 vs. 91.9%, respectively; P = 0.26). Also, the season did not influence the SOV rate (warm season = 89.3% vs. not warm season = 92.2%; P = 0.09). Lactating donor had higher number of CL (10.6 ± 0.6 vs. 7.5 ± 0.4; P <0.0001), of recovered structures (7.6 ± 0.6 vs. 4.6 ± 0.4; P <0.0001) and recovery rate (77.6 vs. 58.7%; P <0.0001) than heifers. Donors superovulated during warm season had fewer number of CL (8.3 ± 0.5 vs. 9.7 ± 0.5; P = 0.03), of recovered structures (5.3 ± 0.5 vs. 6, 7 ± 0.5; P = 0.04) and recovery rate (65.7 vs. 72.3%; P = 0.007). [...] In conclusion, despite the lactating donors had higher superovulatory response, heifers presented similar number of viable embryos, but higher viable embryos rate. The superovulatory response and the embryo production were lower during the warm season. Embryos from lactating Holstein donors had higher conception rate at 31 and 45 days of gestation than embryos from heifers. Although the season did not influence the conception and pregnancy loss rates, there was a negative relationship between average maximum temperature during estrus and TE and conception rate.