A key piece of the puzzle: The central tetramer of the Saccharomyces cerevisiae septin protofilament and its implications for self-assembly.

Septins, often described as the fourth component of the cytoskeleton, are structural proteins found in a vast variety of living beings. They are related to small GTPases and thus, generally, present GTPase activity which may play an important (although incompletely understood) role in their organization and function. Septins polymerize into long non-polar filaments, in which each subunit interacts with two others by alternating interfaces, NC and G. In Saccharomyces cerevisiae four septins are organized in the following manner, [Cdc11-Cdc12-Cdc3-Cdc10-Cdc10-Cdc3-Cdc12-Cdc11]n in order to form filaments. Although septins were originally discovered in yeast and much is known regarding their biochemistry and function, only limited structural information about them is currently available. Here we present crystal structures of Cdc3/Cdc10 which provide the first view of the physiological interfaces formed by yeast septins. The G-interface has properties which place it in between that formed by SEPT2/SEPT6 and SEPT7/SEPT3 in human filaments. Switch I from Cdc10 contributes significantly to the interface, whereas in Cdc3 it is largely disorded. However, the significant negative charge density of the latter suggests it may have a unique role. At the NC-interface, we describe an elegant means by which the sidechain of a glutamine from helix α0 imitates a peptide group in order to retain hydrogen-bond continuity at the kink between helices α5 and α6 in the neighbouring subunit, thereby justifying the conservation of the helical distortion. Its absence from Cdc11, along with this structure's other unusual features are critically discussed by comparison with Cdc3 and Cdc10.

Do Brazilian medical journals reference Brazilian articles? A cross-sectional study.

Background: The quantity and quality of Brazilian scientific output increases decade by decade. However, there is a tendency to undervalue Brazilian journals, illustrated by the low number of citations compared with texts in international journals, with the tacit justification that foreign articles are of superior quality. Objectives: To investigate the differences in numbers of citations of Brazilian and international periodicals in three Brazilian journals from 2016 to 2020. Methods: All articles published in the Journal of the Brazilian College of Surgeons, in the Jornal Vascular Brasileiro, and in Acta Cirúrgica Brasileira from 2016 to 2020 were analyzed. The references of these studies were analyzed, summing the total number of citations and classifying them as published in Brazilian or foreign journals. Results: A total of 902 articles were analyzed, totaling 23,394 references, with a mean of 25.81 ± 8.59 references per article. Of these, 2,680 (11.45%) were Brazilian, equating to a mean of 2.95 ± 3.79 Brazilian references per article. Conclusions: It is necessary to improve appreciation of Brazilian periodicals, especially among Brazilian researchers and institutions responsible for science funding.

Novel Porcine Kidney-Based Microsurgery Training Model for Developing Basic to Advanced Microsurgical Skills.

BACKGROUND: Microsurgery training is critical to the practice of microvascular procedures in many surgical areas. However, even simple procedures require different levels of complex skills. Therefore, simulation-based surgical training, mainly in the area of vascular anastomosis, is of great importance. In this paper, we present a new microsurgery training model for the development of basic to advanced microsurgical skills. METHODS: Porcine kidneys were purchased from a legal butchery slaughterhouse. First, kidneys were washed with water to remove blood and clots inside vessels. Then, dissection was performed throughout the vascular pedicle from the renal arteries to the segmentary branches. Finally, the longitudinal sectioning of the kidney parenchyma was performed to expose the vessels necessary for training. Sixty end-to-end anastomoses were performed. Specific instruments and materials were used to perform anastomoses and dissections with magnification by a video system. We evaluated the diameter of vessels, time to perform anastomosis, and patency of anastomosis. RESULTS: There was no great anatomical variation among the porcine kidneys. The total length for dissection training was 25.80 ± 7.44 cm using the arterial and venous vessel. The average time to perform arterial anastomoses was 23.79 ± 4.55 minutes. For vessel diameters of ≤ 3, 4 to 6, and 7 to 10 mm, the average procedure times were 27.68 ± 3.39, 22.92 ± 4.12, and 20.77 ± 3.44 minutes, respectively. Regarding venous anastomosis, the average duration of the procedure was 26.17 ± 4.80 minutes, including durations of 31.61 ± 3.86, 25.66 ± 4.19, and 21.24 ± 3.79 minutes for vessel diameters of ≤ 7, 8 to 10, and >10 mm, respectively. Positive patency was achieved in all surgeries. CONCLUSION: The porcine kidney provides an inexpensive and convenient biological model for modeling microanastomosis with high fidelity to vascular structures.

Pamidronate Attenuates Oxidative Stress and Energetic Metabolism Changes but Worsens Functional Outcomes in Acute Doxorubicin-Induced Cardiotoxicity in Rats.

BACKGROUND: Cardiotoxicity is the major side effect of doxorubicin. As mechanisms that are involved in cardiotoxicity are ambiguous, new methods for attenuating cardiotoxicity are needed. Recent studies have shown that bisphosphonates can decrease oxidative stress. Therefore, the objective of this study was to evaluate the effect of pamidronate on preventing acute doxorubicin-induced cardiotoxicity. METHODS: Sixty-four male Wistar rats were allocated into four groups: the control group (C), the pamidronate group (P), the doxorubicin group (D) and the doxorubicin/pamidronate group (DP). The rats in the P and DP groups received pamidronate injections (3 mg/kg, IP). After 24 hours, the rats in the D and DP groups received doxorubicin injections (20 mg/kg, IP). Forty-eight hours after doxorubicin injection, the rats were killed. Echocardiography, isolated heart study and biochemical analysis were performed. RESULTS: Doxorubicin-induced acute cardiotoxicity showed increased matrix metalloproteinases (MMP)-2 activation, oxidative damage and induced alterations in myocardial energetic metabolism. Pamidronate did not inhibit MMP-2 activation but attenuated oxidative stress and improved myocardial energetic metabolism. Regarding cardiac function, the DP group exhibited a decrease in the left ventricular ejection fraction in the echocardiography and a decrease in +dP/dt in the isolated heart study compared with other groups. The same DP group presented serum hypocalcaemia. CONCLUSIONS: Despite its ability to reduce oxidative stress and improve energy metabolism in the heart, pamidronate worsened systolic function in rats treated with doxorubicin, and therefore we cannot recommend its use in conjunction with anthracycline chemotherapy.

Clinical and sociodemographic characteristics of patients with epilepsy attended at a regional reference psychiatric emergency unit.

OBJECTIVE: Epilepsy is one of the most prevalent chronic neurological diseases, presenting a high frequency of psychiatric disorders (PD). This study sought to evaluate the clinical and sociodemographic profile of patients with epilepsy (PWE) attended at a regional reference psychiatric emergency unit. METHODS: A retrospective, cross-sectional, and descriptive observational study was conducted utilizing a patient record database of individuals with epilepsy who were attended in a regional reference psychiatric emergency unit between January 2018 and August 2022. RESULTS: Out of the 31,800 psychiatric emergency visits, 260 (0.8 %) were of patients with epilepsy (ICD-10: G40). The majority were males (63.5 %) with a mean age of 42.11±15.39 years, single marital status (154; 59.25 %) and elementary education (75; 28.9 %). Most of them (203; 78.1 %) presented at least one psychiatric comorbidity at the emergency visit, but 109 (41.9 %) were not receiving any psychiatric follow-up. A total of 106 patients (40.8 %) had experienced at least one past psychiatric hospitalization. CONCLUSIONS: The occurrence of PD is highly prevalent in PWE, and probably with a high frequency of psychiatric emergencies occurring among them. Further studies are needed to assess such patient profile, particularly involving data from psychiatric emergency units.

End-to-side neurorrhaphy in the reconstruction of peripheral segmental neural loss: an experimental study.

PURPOSE: To evaluate the effects on peripheral neural regeneration of the end-to-side embracing repair technique compared to the autograft repair technique in Wistar rats. METHODS: Fifteen male Wistar rats were divided into three groups with five animals each: denervated group (GD), autograft group (GA), and embracing group (EG). For the evaluation, the grasping test, electroneuromyography (ENMG), and muscle weight assessment were used. RESULTS: Muscle weight assessment and ENMG did not show significant neural regeneration at the end of 12 weeks in the DG and GE groups, but only in GA. The grasping test showed an increase in strength between the surgery and the fourth week in all groups, and only the GA maintained this trend until the 12th week. CONCLUSIONS: The present study indicates that the neural regeneration observed in the end-to-side embracing neurorrhaphy technique, in the repair of segmental neural loss, is inferior to autograft repair in Wistar rats.

Low cost and easy acquisition: corn grain in microsurgery training.

OBJECTIVES: develop an easily accessible model for training the initial motor practice in microsurgery using corn kernels. METHODS: ten corn kernels (Zea mays) were used. A 7mm longitudinal cut was made on one side of the corn grain. The training consisted of performing 4 simple knots between the edges of the incision, using 10-0 mononylon thread. The parameters analyzed were 1) cost of the model; 2) assembly time of the model test system; 3) time for performing the knots; 4) distance between the knots. RESULTS: in all corn kernels tested, it was possible to perform the proposed microsurgical suture training, without any difficulty in the procedure. The average time to perform the 4 knots was 6.51±1.18 minutes. The total cost of the simulator model was R$3.59. The average distance between the knots was 1.7±0.3mm. The model developed from corn grains has an extremely low cost when compared to the use of animals or high-tech simulators. Other advantages are the easy availability of canned corn kernels and the possibility of making more than four knots along the 7mm incision. CONCLUSION: the training model developed has low cost, is easy to acquire and viable for training basic manual skills in microsurgery.

Integrated use of plant growth-promoting bacteria and nano-zinc foliar spray is a sustainable approach for wheat biofortification, yield, and zinc use efficiency.

Introduction and aims: The intensive cropping system and imbalance use of chemical fertilizers to pursue high grain production and feed the fast-growing global population has disturbed agricultural sustainability and nutritional security. Understanding micronutrient fertilizer management especially zinc (Zn) through foliar application is a crucial agronomic approach that could improve agronomic biofortification of staple grain crops. The use of plant growth-promoting bacteria (PGPBs) is considered as one of the sustainable and safe strategies that could improve nutrient acquisition and uptake in edible tissues of wheat to combat Zn malnutrition and hidden hunger in humans. Therefore, the objective of this study was to evaluate the best-performing PGPB inoculants in combination with nano-Zn foliar application on the growth, grain yield, and concentration of Zn in shoots and grains, Zn use efficiencies, and estimated Zn intake under wheat cultivation in the tropical savannah of Brazil. Methods: The treatments consisted of four PGPB inoculations (without inoculation, Azospirillum brasilense, Bacillus subtilis, and Pseudomonas fluorescens, applied by seeds) and five Zn doses (0, 0.75, 1.5, 3, and 6 kg ha-1, applied from nano ZnO in two splits by leaf). Results: Inoculation of B. subtilis and P. fluorescens in combination with 1.5 kg ha-1 foliar nano-Zn fertilization increased the concentration of Zn, nitrogen, and phosphorus in the shoot and grain of wheat in the 2019 and 2020 cropping seasons. Shoot dry matter was increased by 5.3% and 5.4% with the inoculation of P. fluorescens, which was statistically not different from the treatments with inoculation of B. subtilis as compared to control. The grain yield of wheat was increased with increasing nano-Zn foliar application up to 5 kg Zn ha-1 with the inoculation of A. brasilense in 2019, and foliar nano-Zn up to a dose of 1.5 kg ha-1 along with the inoculation of P. fluorescens in the 2020 cropping season. The zinc partitioning index was increased with increasing nano Zn application up to 3 kg ha-1 along with the inoculation of P. fluorescens. Zinc use efficiency and applied Zn recovery were improved at low doses of nano-Zn application in combination with the inoculation of A. brasilense, B. subtilis, and P. fluorescens, respectively, as compared to control. Discussion: Therefore, inoculation with B. subtilis and P. fluorescens along with foliar nano-Zn application is considered a sustainable and environmentally safe strategy to increase nutrition, growth, productivity, and Zn biofortification of wheat in tropical savannah.

Association between the rs820218 Variant within the SAP30BP Gene and Rotator Cuff Rupture in an Amazonian Population.

BACKGROUND: Rotator cuff disease is one of the leading causes of musculoskeletal pain and disability, and its etiology is most likely multifactorial but remains incompletely understood. Therefore, the objective of this research was to investigate the relationship of the single-nucleotide rs820218 polymorphism of the SAP30-binding protein (SAP30BP) gene with rotator cuff tears in the Amazonian population. METHODS: The case group consisted of patients who were operated on due to rotator cuff tears in a hospital in the Amazon region between 2010 and 2021, and the control group was composed of individuals who were selected after negative physical examinations for rotator cuff tears. Genomic DNA was obtained from saliva samples. For the genotyping and allelic discrimination of the selected single nucleotide polymorphism (rs820218) in the SAP30BP gene, real-time PCR was performed. RESULTS: The frequency of the A allele in the control group was four times as high as that in the case group (AA homozygotes); an association of the genetic variant rs820218 of the SAP30BP gene with rotator cuff tears was not established (p = 0.28 and 0.20), as the A allelic frequency is ordinarily low in the general population. CONCLUSIONS: The presence of the A allele indicates protection against rotator cuff tears.

Vocal Symptoms in Brazilian Professors: Self-Perception and Relationship Factors.

OBJECTIVE: This study aimed to investigate the self-perception of vocal symptoms and relationship factors in Brazilian academic teacher. METHODS: This was a cross-sectional study. The study sample consisted of 235 Brazilian academic teachers, of whom 103 were men and 132 women, aged between 26 and 67 years, and employed at 39 institutions. All participants filled out a questionnaire detailing the presence of vocal complaints, and occupation and sociodemographic information. The vocal symptoms were investigated using voice symptom scale. RESULTS: Academic teacher with vocal complaints showed a higher perception of vocal symptoms in all domains (P < 0.001 for all). Other factors did not result in any significant difference. CONCLUSION: The only factor that influences the self-perception of vocal symptoms in Brazilian academic teachers is the presence of vocal complaints.

Vocal fatigue in professors at the beginning and end of the school year. / Fadiga vocal em professores universitários no início e ao final do ano letivo.

PURPOSE: To characterize and to compare the perception of vocal fatigue in professors at the beginning and at the end of the school year. METHODS: Observational, analytical, prospective cohort study was carried out. A total of 115 professors participated with a mean age of 40 years old, 71 women and 44 men, employees of 28 higher education institutions in the south and southeast regions of Brazil. All answered to the Vocal Fatigue Index (VFI) at the beginning (February or March) and at the end (October or November) of the Brazilian school year. The VFI results for both assessed moments were statistically compared (p<0.05). RESULTS: The professors' mean scores obtained in the factors of tiredness of voice and avoidance of voice use (p<0.001) and improvement of symptoms with rest (p=0.001) increased at the end of the school year. CONCLUSION: Professors reported higher perception of vocal fatigue at the end of the school year, which influenced the avoidance of voice use and improvement of symptoms with the rest.

OBJETIVO: Caracterizar e comparar a percepção de fadiga vocal em professores universitários no início e ao final do ano letivo. MÉTODO: Estudo observacional, analítico, de coorte prospectivo. Participaram 115 professores universitários, idade média de 40 anos, sendo 71 mulheres e 44 homens, funcionários de 28 instituições de ensino superior das regiões sul e sudeste do Brasil. Todos responderam ao Índice de Fadiga Vocal (IFV) no início (fevereiro ou março) e ao final (outubro ou novembro) do ano letivo. RESULTADOS: Os resultados obtidos no IFV nos dois momentos foram comparados estatisticamente (p<0,05). Resultados: Os escores médios obtidos nos domínios fadiga e restrição vocal (p<0,001) e recuperação com repouso vocal (p=0,001) dos professores universitários aumentaram ao final do ano letivo. CONCLUSÃO: Professores universitários referiram maior percepção de fadiga vocal ao final do ano letivo, o que influenciou na restrição vocal e na recuperação com repouso vocal.

Correction: Structural characterization of a pathogenicity-related superoxide dismutase codified by a probably essential gene in Xanthomonas citri subsp. citri.

[This corrects the article DOI: 10.1371/journal.pone.0209988.].

Inoculation of Azospirillum brasilense associated with silicon as a liming source to improve nitrogen fertilization in wheat crops.

This research was developed to investigate whether inoculation with Azospirillum brasilense in combination with silicon (Si) can enhance N use efficiency (NUE) in wheat and to evaluate and correlate nutritional and productive components and wheat grain yield. The study was carried out on a Rhodic Hapludox under a no-till system with a completely randomized block design with four replications in a 2 × 2 × 5 factorial scheme: two liming sources (with Ca and Mg silicate as the Si source and limestone); two inoculations (control - without inoculation and seed inoculation with A. brasilense) and five side-dress N rates (0, 50, 100, 150 and 200 kg ha-1). The results of this study showed positive improvements in wheat growth production parameters, NUE and grain yield as a function of inoculation associated with N rates. Inoculation can complement and optimize N fertilization, even with high N application rates. The potential benefits of Si use were less evident; however, the use of Si can favour N absorption, even when associated with A. brasilense. Therefore, studies conducted under tropical conditions with Ca and Mg silicate are necessary to better understand the role of Si applied alone or in combination with growth-promoting bacteria such as A. brasilense.

Structural characterization of a pathogenicity-related superoxide dismutase codified by a probably essential gene in Xanthomonas citri subsp. citri.

Citrus canker is a plant disease caused by the bacteria Xanthomonas citri subsp. citri that affects all domestic varieties of citrus. Some annotated genes from the X. citri subsp. citri genome are assigned to an interesting class named "pathogenicity, virulence and adaptation". Amongst these is sodM, which encodes for the gene product XcSOD, one of four superoxide dismutase homologs predicted from the genome. SODs are widespread enzymes that play roles in the oxidative stress response, catalyzing the degradation of the deleterious superoxide radical. In Xanthomonas, SOD has been associated with pathogenesis as a counter measure against the plant defense response. In this work we initially present the 1.8 Å crystal structure of XcSOD, a manganese containing superoxide dismutase from Xanthomonas citri subsp. citri. The structure bears all the hallmarks of a dimeric member of the MnSOD family, including the conserved hydrogen-bonding network residues. Despite the apparent gene redundancy, several attempts to obtain a sodM deletion mutant were unsuccessful, suggesting the encoded protein to be essential for bacterial survival. This intriguing observation led us to extend our structural studies to the remaining three SOD homologs, for which comparative models were built. The models imply that X. citri subsp. citri produces an iron-containing SOD which is unlikely to be catalytically active along with two conventional Cu,ZnSODs. Although the latter are expected to possess catalytic activity, we propose they may not be able to replace XcSOD for reasons such as distinct subcellular compartmentalization or differential gene expression in pathogenicity-inducing conditions.

End-to-side neurorrhaphy in the reconstruction of peripheral segmental neural loss: an experimental study

Purpose: To evaluate the effects on peripheral neural regeneration of the end-to-side embracing repair technique compared to the autograft repair technique in Wistar rats. Methods: Fifteen male Wistar rats were divided into three groups with five animals each: denervated group (GD), autograft group (GA), and embracing group (EG). For the evaluation, the grasping test, electroneuromyography (ENMG), and muscle weight assessment were used. Results: Muscle weight assessment and ENMG did not show significant neural regeneration at the end of 12 weeks in the DG and GE groups, but only in GA. The grasping test showed an increase in strength between the surgery and the fourth week in all groups, and only the GA maintained this trend until the 12th week. Conclusions: The present study indicates that the neural regeneration observed in the end-to-side embracing neurorrhaphy technique, in the repair of segmental neural loss, is inferior to autograft repair in Wistar rats.

Effect of Feeding Bacillus subtilis Spores to Broilers Challenged with Salmonella enterica serovar Heidelberg Brazilian Strain UFPR1 on Performance, Immune Response, and Gut Health.

Salmonellosis is a poultry industry and public health concern worldwide. Recently, Salmonella enterica serovar Heidelberg (SH) has been reported in broilers in Brazil. The effect of feeding a blend of three strains of Bacillus subtilis (PRO) was studied in broilers orally challenged (107 CFU/chick) or not with a SH isolated in south of Brazil (UFPR1 strain). Twelve male Cobb 500 broilers per pen were randomly assigned to six treatments in a 3 × 2 factorial experiment where PRO was added at 0, 250, or 500 g/ton of broiler feed and fed to either SH-challenged (SH Control, SH + PRO 250, and SH + PRO 500) or non-challenged birds (Control, PRO 250, and PRO 500). Broiler performance, histologic alterations in intestinal morphology, Salmonella quantification and immune cells counts in liver (macrophages, T CD4+ and T CD8+) were analyzed. Changes in the intestinal microbiota of broilers were also studied by metagenomics for Control, SH Control, SH + PRO 250, and SH + PRO 500 only. Feeding PRO at 250 or 500 g/ton reduced SH counts and incidence in liver and cecum at 21 days of age. It was observed that PRO groups increased the macrophage mobilization to the liver in SH-challenged birds (P < 0.05) but reduced these cells in the liver of non-challenged birds, showing an interesting immune cell dynamics effect. PRO at 250 g/ton did not affect gut histology, but improved animal performance (P < 0.05) while PRO at 500/ton did not affect animal performance but increased histologic alteration related to activation of the defense response in the ileum in SH challenged birds compared to control birds (P < 0.05). SH + PRO 500 group presented a more diverse cecal microbiota (Shannon-Wiener index; P < 0.05) compared to Control and SH Control groups; while SH + PRO 250 had greater ileal richness (JackkNife index) compared to Control (P < 0.05). PRO was effective in reducing Salmonella colonization in liver and cecum when fed at 250 or 500 g/ton to broilers inoculated with SH strain UFPR1. PRO promotes positive alterations in performance (at 250 g/ton), immune modulatory effect in the gastrointestinal tract, SH reduction, and intestinal microbiota modulation.

What came first: the egg or the microsurgery training? An ophthalmic model for developing basic skills in microsurgery / O que veio primeiro: o ovo ou o treinamento microcirúrgico? Um modelo oftalmológico para desenvolver habilidades básicas em microcirurgia

ABSTRACT Purpose: To describe a new accessible model of ophthalmological training using chicken eggs. Methods: With the aid of a spherical drill, the external calcified layer and the cuticle of the chicken eggshell were removed in a 2cm diameter circle. Using a video-magnification system, the film was dissected and cut to approximately 1.5 cm diameters. The film was removed and repositioned to make interrupted 12-0 nylon microsutures. The parameters analyzed were: cost, facility of acquisition and handling, time for making the model and the microsutures and number of possible uses. Results: In all simulators, it was possible to carry out separated and equidistant micro-sutures in the egg membrane, without the need for reintervention. Conclusion: The new chicken-egg model for ophthalmic surgery training is low-cost, easy to acquire and handle, and viable for the development of basic microsurgery skills.

RESUMO Objetivo: Descrever um novo modelo acessível de treinamento oftalmológico com ovo de galinha. Métodos: Com o auxílio de uma broca esférica, a camada calcificada externa e a cutícula da casca do ovo de galinha foram retiradas em um círculo 2 cm de diâmetro. Mediante um sistema de videomagnificação, a película foi dissecada e cortada em formato aproximado de 1,5 cm de diâmetro. A película foi removida e reposicionada para a confecção de microssuturas interrompidas com nylon 12-0. Os parâmetros analisados foram: custo, facilidade de aquisição e manuseio, tempo para confecção do modelo e para a confecção das microssuturas e número de utilizações possíveis. Resultados: Em todos os simuladores foi possível realizar microssuturas separadas e equidistantes na membrana do ovo, sem necessidade de reintervenção. Conclusão: O novo modelo com ovo de galinha para o treinamento de cirurgia oftalmológica é de baixo custo, fácil aquisição e manuseio, além de ser viável no desenvolvimento de habilidades básicas em microcirurgia.

Os periódicos médicos brasileiros referenciam artigos nacionais? Um estudo transversal / Do Brazilian medical journals reference Brazilian articles? A cross-sectional study

Resumo Contexto A produção científica brasileira cresce de forma quantitativa e qualitativa a cada década. Entretanto, há uma desvalorização dos periódicos brasileiros demonstrada através da baixa quantidade de citações em comparação a textos de revistas internacionais, com justificativa subentendida de que há superioridade qualitativa de artigos estrangeiros. Objetivos Verificar a diferença entre o número de citações de periódicos nacionais e internacionais em três revistas brasileiras no período de 2016 a 2020. Métodos Foram analisados todos os artigos publicados na Revista do Colégio Brasileiro de Cirurgiões, no Jornal Vascular Brasileiro e na Acta Cirúrgica Brasileira no intervalo de 2016 a 2020. Os estudos selecionados tiveram suas referências avaliadas, sendo contabilizado o número total de citações e se eram provenientes de periódicos brasileiros ou de periódicos estrangeiros. Resultados Foram analisados 902 artigos, totalizando 23.394 referências, com média de 25,81 ± 8,59 por artigo. Nesse contexto, 2.680 (11,45%) eram nacionais, correspondentes a uma média de 2,95 ± 3,79 referências brasileiras por artigo. Conclusões Faz-se necessária a maior valorização dos periódicos brasileiros, em especial por parte dos pesquisadores nacionais e das instituições responsáveis pelo fomento da ciência.

Abstract Background The quantity and quality of Brazilian scientific output increases decade by decade. However, there is a tendency to undervalue Brazilian journals, illustrated by the low number of citations compared with texts in international journals, with the tacit justification that foreign articles are of superior quality. Objectives To investigate the differences in numbers of citations of Brazilian and international periodicals in three Brazilian journals from 2016 to 2020. Methods All articles published in the Journal of the Brazilian College of Surgeons, in the Jornal Vascular Brasileiro, and in Acta Cirúrgica Brasileira from 2016 to 2020 were analyzed. The references of these studies were analyzed, summing the total number of citations and classifying them as published in Brazilian or foreign journals. Results A total of 902 articles were analyzed, totaling 23,394 references, with a mean of 25.81 ± 8.59 references per article. Of these, 2,680 (11.45%) were Brazilian, equating to a mean of 2.95 ± 3.79 Brazilian references per article. Conclusions It is necessary to improve appreciation of Brazilian periodicals, especially among Brazilian researchers and institutions responsible for science funding.

Low cost and easy acquisition: corn grain in microsurgery training / Baixo custo e fácil aquisição: grãos de milho no treinamento microcirúrgico

ABSTRACT Objectives: develop an easily accessible model for training the initial motor practice in microsurgery using corn kernels. Methods: ten corn kernels (Zea mays) were used. A 7mm longitudinal cut was made on one side of the corn grain. The training consisted of performing 4 simple knots between the edges of the incision, using 10-0 mononylon thread. The parameters analyzed were 1) cost of the model; 2) assembly time of the model test system; 3) time for performing the knots; 4) distance between the knots. Results: in all corn kernels tested, it was possible to perform the proposed microsurgical suture training, without any difficulty in the procedure. The average time to perform the 4 knots was 6.51±1.18 minutes. The total cost of the simulator model was R$3.59. The average distance between the knots was 1.7±0.3mm. The model developed from corn grains has an extremely low cost when compared to the use of animals or high-tech simulators. Other advantages are the easy availability of canned corn kernels and the possibility of making more than four knots along the 7mm incision. Conclusion: the training model developed has low cost, is easy to acquire and viable for training basic manual skills in microsurgery.

RESUMO Objetivo: desenvolver um modelo facilmente acessível para o treinamento da prática motora inicial em microcirurgia a partir da utilização de grãos de milho. Métodos: foram utilizados dez grãos de milho (Zea mays). Realizou-se um corte longitudinal de 7mm em uma das faces do grão de milho. O treinamento consistiu na realização de 4 pontos simples entre as bordas da incisão, utilizando fio de mononáilon 10-0. Os parâmetros analisados foram 1) custo do modelo; 2) tempo de montagem do sistema de teste do modelo; 3) tempo de realização dos nós; 4) distância entre os pontos. Resultados: em todos os grãos testados foi possível realizar o treinamento de sutura microcirúrgica proposto, sem dificuldade ao procedimento. O tempo médio para a realização dos 4 pontos foi de 6,51±1,18 minutos. O custo total do modelo simulatório foi de R$3,59. A distância média entre os pontos foi de 1,7±0,3mm. O modelo desenvolvido a partir de grãos de milhos apresenta custo extremamente baixo quando comparado ao uso de animais ou de simuladores de alta tecnologia. Outras vantagens são fácil disponibilidade de grãos de milho em conserva e possibilidade de serem realizados mais de quatro pontos ao longo da incisão de 7mm. Conclusão: o modelo de treinamento desenvolvido é de baixo custo, de fácil aquisição e viável para o treinamento de habilidades manuais básicas em microcirurgia.