bluuebunny/crossref_metadata_2025 huggingface dataset:
Water productivity and agronomic performance of strawberries with different leaching fractions application
Authors: Gontijo Mariana Lúcio , Souza Fabiana Silva , Diotto Adriano Valentim , Souza Fabiana Silva de , Gontijo Fernanda Lúcio
Published: April 2021

Strawberry is an economically important crop. However, because this crop is very susceptible to pests and diseases, the use of new management techniques, such as semi-hydroponic cultivation, is necessary. One of the greatest difficulties for producers in the transition from soil to semi-hydroponic cultivation is fertigation management. As most crops in Brazil are grown in open fields, monitoring the electrical conductivity of the drained solution is key. Thus, the aim of this study was to use different leaching fractions to evaluate the control of saline levels and the productivity of the San Andreas strawberry. The experimental design was completely randomized. The treatments consisted of different leaching fractions, equivalent to 10, 20, 30, and 50% excess irrigation. Most of the evaluated traits were significantly affected at the 5% level of significance according to Tukey’s test. The 30% leaching fraction showed the best results in practically all evaluations, with better values obtained even for water productivity and with 19.92 g of fruit per liter of solution used.
Síntese, atividade antifúngica e docking molecular de derivados do eugenol
Authors: Lima Josefa Aqueline Cunha , Silva Jadson Farias , Caiana Rodrigo Ribeiro Alves , Silva Júnior Josivan Pereira , Oliveira Wylly Araujo , Freitas Juliano Carlo Rufino
Published: April 2021

Este trabalho descreve a síntese e atividade antifúngica de derivados do eugenol e o docking molecular do eugenol contendo uma unidade 1,2,3-triazólica. Os derivados de eugenol foram obtidos por modificações fenólicas na hidroxila, enquanto a concentração inibitória mínima foi determinada pelo método de microdiluição em caldo. O docking molecular do derivado de eugenol com funcionalidade 1,2,3-triazol foi realizado com a enzima esterol 14-alfa desmetilase (CYP51) e demonstrou que este composto não interage favoravelmente com esta enzima, diferentemente do posaconazol. Os derivados do eugenol foram obtidos com bons rendimentos e a avaliação antifúngica mostrou que, após modificações, a atividade antifúngica foi mantida em alguns exemplos. O resultado do docking molecular nos permitiu vislumbrar alguns motivos que justificam a ausência de atividade antifúngica do derivado de eugenol com funcionalidade 1,2,3-triazol. Em resumo, o artigo fornece informações importantes que ajudarão na realização de pesquisas futuras envolvendo este produto natural.
Associação dos fatores sociodemográficos e patológicos com os resultados perinatais de gestantes adolescentes no sul do Brasil
Authors: Valoni Gabriela Rolim , Ribeiro Ronan Santos , Pelloso Sandra Marisa , Antunes Marcos Benatti
Published: April 2021

Objetivou-se analisar a associação dos fatores sociodemográficos e patológicos com os resultados perinatais em gestantes adolescentes entre 12 a 18 anos, classificadas como alto risco e acompanhadas por um serviço especializado. Trata-se de um estudo exploratório, descritivo de abordagem quantitativa. Foram analisados 920 prontuários de gestantes de alto risco, no período de setembro de 2012 a setembro de 2013. Os dados foram submetidos aos testes qui-quadrado (x²) e teste exato de Fisher. Do total, 6,7% eram gestantes adolescentes, das quais 5,2% foram selecionadas para esse estudo por realizarem o parto no hospital referência. A média de idade foi de 16,7anos e em relação ao número de gestações 18,8% adolescentes já estavam na segunda gestação, predominou-se o parto normal com 52,1%. Em relação às condições de riscos, nas condições clínicas pré-existentes, destaca-se a prevalência de hipertensão arterial (8,3%) e dependência de drogas lícitas (8,3%), nos antecedentes obstétricos o parto prematuro apresentou prevalência de 8,3%. Já nas intercorrências na atual gestação, destacou-se a malformação fetal (16,7%), seguido do trabalho de parto prematuro (12,5%). Quando analisado o desfecho perinatal das adolescentes, aquelas que apresentaram condições clínicas pré-existentes obtiveram associação estatística significativa para baixo peso ano nascer (p=0,03), intercorrência clínica na atual gestação apresentaram associação com o parto pré-termo (p=0,04) e baixo peso ao nascer (p=0,001). Conclui-se que a gestação na adolescência se relaciona com os riscos maternos tendo como consequência as complicações neonatais, destacando o parto pré-termo e o baixo peso ao nascer.
Síntese, assinalamento completo e estudo do perfil farmacocinético, bioativo e de toxicidade do 2-propin-1-il 2,3,4,6-tetra-O-acetil-β-D-glicopiranose
Authors: Santos Jonh Anderson Macêdo , Santos Cláudia Laís Araújo Almeida , Freitas Filho João Rufino , Freitas Juliano Carlo Rufino
Published: April 2021

Os O-glicosídeos são carboidratos de ocorrência natural e que apresentam atividades biológicas promissoras. No entanto, o caminho convencional para comercialização de um medicamento envolve um processo exaustivo e caro. Em contrapartida, pesquisas baseadas em uma abordagem in silico, têm se mostrado eficientes na predição de propriedades farmacodinâmicas, reduzindo tempo e custos. Nesse trabalho, relatamos a síntese, assinalamento completo e avaliação do perfil farmacocinético e de toxicidade do 2-propin-1-il 2,3,4,6-tetra-O-acetil-β-D-glicopiranose. O composto foi obtido em bom rendimento e excelente estereosseletividade. A partir do experimento de NOESY foi possível determinar o produto majoritário da reação de glicosilação. O estudo in silico, relatado pela primeira vez, indicou que este composto apresenta boa biodisponibilidade oral, é ativo frente aos principais alvos moleculares e exibe baixa toxicidade.
Physico-chemical and microbiological evaluation of açaí pulp processed in Igarapé-Miri, PA
Authors: Aires Cassia Barbosa , Gomes Paulo Wender Portal , Pelais Ana Carla Alves , Figueiredo Elaine Lopes , Martins Luiza Helena da Silva
Published: April 2021

Açaí is a fruit widely consumed in northern Brazil; has a high energy and antioxidant value. In addition, it is rich in anthocyanins, lipids, carbohydrates, fibers, vitamins and minerals. However, inadequate practices lead to physical, chemical and biological contamination during production, processing and transportation, consequently increasing the risk of diseases transmitted by this food. In this work, we evaluated the physical-chemical quality (pH and anthocyanins), microbiological (thermotolerant coliforms, mesophilic aerial bacteria, filamentous fungi and yeasts, Salmonella ssp; Trypanosoma cruzi) and heavy metals from açaí pulp from an industry located in Igarapé-Miri-PA. The pH results ranged from 5.10 to 5.35, anthocyanins between 67 mg/100 g to 113 mg/100 g, both were in accordance with current Brazilian legislation. As for the microbiological results, contamination by Salmonella ssp. and Trypanosoma cruzi; for heavy metal analysis the samples were in accordance with current legislation. Therefore, we suggest that the pulps produced in Igarapé-Miri have a quality standard to reach the consumer market without risks to human health.
A fauna de abelhas sem ferrão em áreas urbanas: 50 anos de estudos e prioridades de pesquisa no Brasil
Authors: Lima dos Santos Samuel Júlio , Barbosa Bruno Corrêa , Prezoto Fábio
Published: April 2021

As abelhas sem ferrão são fundamentais para a manutenção de áreas verdes presentes em centros urbanos, através da polinização. Contudo, o ambiente urbano oferece uma série de desafios que influenciam a riqueza e diversidade desses insetos. Nós objetivamos realizar uma análise detalhada dos estudos de diversidade de abelhas sem ferrão em áreas urbanas publicados nos últimos 50 anos. Para a revisão de literatura, foram selecionadas as publicações que estavam indexadas em bases de dados conhecidas, com palavras-chave indicando o assunto, dentro do período de tempo requerido para a análise. Foram encontradas 44 publicações, a maioria publicada em revistas científicas (77,27%). Os estudos começaram a ser publicados regularmente a partir do começo da década de 2000, sendo 2003, 2005, 2010 e 2012 os anos mais produtivos. Houve concentração de publicação de estudos nos estados do Paraná, Minas Gerais e São Paulo. Entre os estudos foram utilizados seis diferentes métodos de coleta, sendo que, os métodos de Busca Ativa (ou Varredura) e Busca por Ninhos demonstraram ser os mais utilizados. Verificamos que as espécies mais encontradas em ambiente urbano, segundo as publicações, são Trigona spinipes e Tetragonisca angustula. Almejamos com as informações presentes nessa análise contribuir para o conhecimento sobre a diversidade urbana de abelhas sem ferrão, além de indicar locais prioritários para a execução de futuros estudos com o grupo no Brasil.
Enabling the Environment for Private Sector Investment: Impact on Food Security and Poverty
Authors: Post Lori , Schmitz Andrew , Issa Tariq , Oehmke James
Published: April 2021

Millions of people worldwide live in extreme poverty, which has an adverse effect on global food security. Research shows that growth in the agricultural labor sector has twice the impact on poverty compared to growth in other labor sectors. To that end, we examine some of the enabling factors of private sector investment to increase food security and reduce poverty: innovative output, intellectual property rights innovation, gender-sensitive land tenure, creation of new businesses, openness to trade, government institutional flexibility, access to credit, inclusion of new sectors, income diversification, public-private partnerships, infrastructure improvements, payments for eco-system services, and climate-smart innovation. Developing policies that improve food security will help to reduce poverty.
Joint Improvisation, Minimalism and Pluralism about Joint action
Authors: Saint-Germier Pierre , Paternotte Cédric , Canonne Clément
Published: April 2021

This paper introduces freely improvised joint actions, a class of joint actions characterized by (i) highly unspecific goals and (ii) the unavailability of shared plans. For example, walking together just for the sake of walking together with no specific destination or path in mind provides an ordinary example of FIJAs, along with examples in the arts, e.g., collective free improvisation in music, improv theater, or contact improvisation in dance. We argue that classic philosophical accounts of joint action such as Bratman’s rule them out because the latter require a capacity for planning that is idle in the case of FIJAs. This argument is structurally similar to arguments for minimalist accounts of joint action (e.g., based on joint actions performed by children before they develop a full-fledged theory of mind), and this invites a parallel minimalist account, which we provide in terms of a specific kind of shared intentions that do not require plan states. We further argue that the resulting minimalist account is different in kind from the sort of minimalism suggested by developmental considerations and conclude in favor of a pluralistic minimalism, according to which there are several ways for an account of joint action to be minimal.
Height to Crown Base Modelling for the Main Tree Species in an Even-Aged Pedunculate Oak Forest
Authors: Martín-García Saray , Balenović Ivan , Jurjević Luka , Lizarralde Iñigo , Indir Krunoslav , Rafael Alonso Ponce Rafael
Published: April 2021

The height to crown base (hcb) is a critical measure used in many investigations as an input variable to investigate the vigour of the stands, the social position of the trees, and to evaluate the behaviour of forest fires, among other uses. Though measuring height-related variables in the field is always time-consuming, the foremost benefits offered by modelling hcb are that it permits to generalize and average a very uneven attribute and, furthermore, provides insights about which tree and stand variables have a significant impact on hcb. However, there are many species in which models of the crown base height have not been developed in Croatia. The objective of this research was to develop a height to base crown model for each of the main species present in the two-layered mixed stands of this study. According to previous investigations, logistic models provide the highest precision and require the lowest inventory cost owing to less frequent measurements. Tree- and plot-level variables with distance-independent competition indexes were studied in the fitting model. In this research, we obtained models for the main stand species: Acer campestre (root mean squared error (RMSE) = 2.28 m, R2 = 82.80%); Alnus glutinosa (RMSE = 1.78 m, R2 = 85.36%); Carpinus betulus (RMSE = 2.47 m, R2 = 67.55%); Fraxinus angustifolia (RMSE = 2.46 m, R2 = 82.45%); Quercus robur (RMSE = 2.60 m, R2 = 80.57%); Tilia sp. (RMSE = 2.01 m, R 2 = 89.07%); and Ulmus laevis (RMSE = 1.71 m, R2 = 92.42%). The combination of the total height, tree, and plot-level variables with distance-independent competition indexes contributed to the prediction accuracy of proposed model significantly.
Transforming Textuality
Authors: Coogan Jeremiah
Published: April 2021

Late Antiquity witnessed a revolution in textuality. Numerous new technologies transformed the practices through which readers accessed written knowledge. Editors reconfigured existing works in order to facilitate new modes of access and new possibilities of knowledge. Despite recent investigations of late ancient knowing, tables of contents have been neglected. Addressing this lacuna, I analyze two examples from the early fourth century: Porphyry of Tyre’s outline of the Enneads in his Life of Plotinus and Eusebius of Caesarea’s Gospel canons. Using tables of contents, Porphyry and Eusebius reconfigured inherited corpora; their creative interventions generate and constrain possibilities of reading—sometimes in ways which run against the grain of the assembled material. I thus argue that Porphyry and Eusebius employed tables of contents to structure textual knowledge—and readers’ access to it—by embracing the dual possibilities of order and creativity in order to offer new texts to their readers. This dual function—of affording structure and inviting creative use—was significant in the construction of composite works which characterized much late ancient intellectual production. The examples of Porphyry and Eusebius illuminate broader late ancient practices of collecting and cataloguing textual knowledge.
Ulcerative colitis: nutritional habits as the disease risk factor
Authors: Bikbavova Galiya R. , Livzan Maria A. , Turchaninov Denis V. , Sovalkin Valery I. , Akhmedov Vadim A.
Published: April 2021

Background — Ulcerative colitis results from a complex interaction between genetic, internal (intestinal microflora) and external (environment) factors. Nutrition habits and the consumption of alcoholic beverages have a significant effect on the intraspecific qualitative and quantitative diversity of the intestinal microbiome. There is controversial information about the effect of various nutritional components on the occurrence of ulcerative colitis. Working with patients with ulcerative colitis, we noted specific features of the profiles of their diets before development of the first symptoms.
Aim — To assess influence of nutrition and alcohol factors on risk of ulcerative colitis in the adult population of Western Siberia.
Methods — A retrospective case control study was conducted by interviewing 81 patients with ulcerative colitis and 39 healthy individuals. The study of their diet and alcohol intake was carried out using the standardized World Health Organization countrywide integrated noncommunicable diseases intervention questionnaire, known as CINDI.
Results — The diet of patients with ulcerative colitis from before the first signs of the disease was characterized by rare consumption of fresh and cooked vegetables and of fruits in small portions but high consumption of sugar with tea and/or coffee compared to the healthy respondents. Patients with ulcerative colitis did not tolerate milk and fermented milk products before the disease onset. The average age of alcohol consumption onset for the patients with ulcerative colitis was 19.0 years and the alcohol consumption frequency before the disease’s first symptoms was less than once a month. Patients with ulcerative colitis before the first symptoms’ onset drank significantly less wine during the year and during the day, as well as less wine per single intake compared with the healthy respondents. There were no statistically significant between-group differences for the quantity and frequency of drinking strong alcoholic beverages and beer.
Conclusion — Dietary fibers’ deficiency and excess sugar intake is related to ulcerative colitis; although, wine (20 mL/d) may be protective.
Assessment of the international competitiveness of the corporate income tax of Ukraine
Authors:   State Institution ", Frolova Natalia ,   Institute for Economics and Forecasting, NAS of Ukraine"
Published: April 2021

The article is devoted to assessing the international competitiveness of the corporate income tax system based on the approach of the US Tax Foundation, which develops International Tax Competitiveness Index of the corporate income tax (ICI) and takes into account the level of income tax rates, cost recovery, tax incentives and complexity of tax law. According to the analysis of the international ranking of OECD countries, Estonia, Latvia, Lithuania, and Hungary had the highest ICIs in 2019-2020. The main factors that have had a positive effect on their competitiveness are the low top marginal income tax rate, unlimited loss carryback and carryforward, no restrictions on the list of assets subject to depreciation, as well as the use of accelerated depreciation, which allows companies to compensate for a larger share of the initial value of assets, LIFO inventory or at least inventory by the weighted average cost method, no Patent Box; no tax credit for R&D, and low corporate income tax complexity. The calculation of the ICI for Ukraine, based on the approbation of the methodological approach of the Tax Foundation, found that in 2019-2020 Ukraine with a total score of 55.07 took 24th place out of 35 OECD countries. The author characterizes the main components of Ukrainian corporate income taxation in terms of their impact on international competitiveness; in addition, ways to increase ICI are substantiated.
Some Landmarks in the Romanian history of medicine
Authors:   «Grigore T. Popa» University of Medicine and Pharmacy, Baran Dana
Published: April 2021

The article provides an overview of the development of the history of medical science in Romania. The achievements of Romanian historians in the study of various areas of the history of medicine are presented.
Effectiveness of interferon therapy in time of in-situ primary renal cell carcinoma: first results
Authors:   Baku Health Center, Mukhtarov E.
Published: April 2021

Although targeted kidney cancer (RCC) therapy has resulted in interferon replacement (IFN), IFN is still widely used in metastatic RCC. However, so far, interferon used after nephrectomy. We present the results of the use of interferon in patients with primary RCC in place. 9 patients who did not undergo surgery and did not receive targeted therapy for various reasons. The average age is 67.1 ± 10.9 years (36-77 years). Women – 3 (33.3%), men – 6 (66.7%). One patient had cystic RCC, the rest had RCC. 6 (66.7%) patients had metastases in lungs, 1 – metastases in the brain. Interferon-alpha-2a was administered as follows: Initial dose: 3 million units per day, gradually increasing over 8-12 weeks up to 18 million U / day, and, if possible, up to 36 million U / day as follows: 1-3 days – 3 million units / day, 4-6 days – 9 million units / day, 7-9 days – 18 million units / day, while portability increases the dose in 10-84 days to 36 million units / day. Maintenance dose: at the maximum tolerated dose 3 times a week, but not more than 36 million U / day. Duration of treatment: not less 8 weeks, preferably at least 12 weeks. If there was an effect, the treatment continued, if there was no effect, it stopped. The maximum duration of treatment was 16 months. Only 3 (33.3%) patients had stable disease (SD). 6 (66.7%) patients died as a result of RCC. But in one patient, SV lasts 96 months. Our results confirm limited activity IFN monotherapy for this disease, but in exceptional cases, its use is possible.
Levels of fibroblast growth factor and sulfated glycosoaminoglycans in connective tissue metabolism in patients with mitral valve prolapse and type 1 diabetes mellitus
Authors:   V.N.Karazin Kharkiv National University, Nikolenko O.Ye. , Pavlov S.B. ,   Kharkiv Medical Academy of Postgraduate Education, Korzh O.M. ,   Kharkiv Medical Academy of Postgraduate Education
Published: April 2021

In order to study the influence of the main fibroblast growth factor on the indicators of the state of the main substance of the extracellular matrix, a comparative analysis of their levels in the blood serum was carried out in persons with mitral valve prolapse and type 1 diabetes mellitus. The data obtained showed that the highest level of FGF-2 was observed in patients with a combination of MVP and type 1 diabetes mellitus compared with isolated MVP and diabetes, the control group (p <0.01) Level II of the GAG ​​fraction, which is represented in the main substance of the extracellular the matrix of the heart valve apparatus was also the highest in comorbid pathology, significantly differing from the control group (p <0.05). The level of GAG fraction III was higher among diabetic patients, regardless of the presence or absence of MVP, which is associated with the localization of this GAG fraction in the basement membranes of blood vessels and may be one of the elements of the pathogenesis of diabetic angiopathy
Osteotomía percutánea de la falange distal del hallux. Indicaciones y técnica
Authors: Yañez Arauz Juan Manuel , Yañez Arauz Juan Martín , Montiel Terrón Verónica , Machado Verónica , Alfonso Matías , Villas-Tomé Carlos
Published: April 2021

Introducción: Las técnicas para corregir las deformidades del hallux incluyen osteotomías metatarsianas y falángicas. Las osteotomías sobre la falange proximal corrigen el DASA y el ángulo interfalángico. Sin embargo, no se han publicado las indicaciones para la osteotomía de la falange distal. El objetivo de este artículo es comunicar la técnica y las indicaciones de la osteotomía percutánea de la falange distal del hallux, y evaluar los resultados de una serie de casos.

Materiales y Métodos: Se analizaron 14 pies en los que se realizó una osteotomía de la falange distal del hallux para corregir una deformidad. Se midieron el DASA, la oblicuidad interfalángica y el ángulo falange distal-interfalángico en las radiografías. La técnica quirúrgica fue percutánea con control fluoroscópico. Los resultados se evaluaron mediante las escalas analógica visual de dolor y AOFAS. Seguimiento medio: 52 meses.

Resultados: 13 pies de mujeres y un pie de hombre. Edad promedio: 58 años. Los resultados clínico y estético fueron excelentes, con alivio del dolor. Mejoría de la escala AOFAS: promedio 37 puntos. Análisis comparativo de ángulos preoperatorios y posoperatorios: DASA (p = 0,01), excepto cuando se aisló de la muestra a los pacientes con osteotomía tipo Akin (p = 0,33); ángulos F2-IF y F2-MTF (p <0,00001). Se registraron las complicaciones.

Conclusiones: En la deformidad en valgo de la falange distal del hallux sintomática, se debe considerar una osteotomía correctora sola o asociada a osteotomía de la falange proximal. La osteotomía percutánea de la falange distal es un método eficaz, seguro y rápido.

Nivel de Evidencia: IV
Evaluación de la estabilización de fracturas expuestas de pierna grados I y II de Gustillo en la etapa aguda
Authors: Gorosito Cinalli Emmanuel Iván , Lombardo Ernesto , Baravalle Juan Manuel , González Emanuel David , Derico Jeremías , Parma Julián , Quinto Pages Ignacio , Barbero Agustín
Published: April 2021

Introducción: La fijación interna de las fracturas de pierna expuestas en la etapa aguda, es decir, dentro de las 24 h del trauma es un tema controvertido. El objetivo de este estudio fue evaluar las infecciones asociadas a la colocación de clavos endomedulares en la etapa aguda y a la colocación diferida, en la fijación de fracturas expuestas de pierna grados I y II de Gustillo.

Pacientes y Métodos: Se realizó un estudio de cohorte retrospectivo sobre el tratamiento en la etapa aguda de los pacientes que ingresaron en el hospital con fracturas expuestas de pierna entre 2015 y 2018. Se analizó la tasa de infecciones durante los primeros 6 meses después de la cirugía y se comparó la fijación en la etapa aguda con la fijación diferida.

Resultados: La fijación interna con clavos endomedulares en la etapa aguda, en pacientes con fracturas expuestas de pierna no aumentó, sino que disminuyó la tasa de infecciones en el control posoperatorio.

Conclusión: El estudio avala la colocación de clavos endomedulares en la etapa aguda, en pacientes con fractura de tibia expuestas.

Nivel de Evidencia: II
Artroplastia total de codo después de un proceso infeccioso. Cirugía en dos tiempos
Authors: Gallucci Gerardo , Sánchez Saba Javier , Boretto Jorge , Zaidenberg Ezequiel , Donndorff Agustín , Rellán Ignacio , De Carli Pablo
Published: April 2021

Objetivo: Comunicar los resultados en pacientes con un proceso infeccioso del codo, tratados en 2 etapas quirúrgicas: la primera con un espaciador de cemento con antibiótico y la segunda con una artroplastia total de codo.
Materiales y Métodos: Se describen los criterios de inclusión, el diagnóstico de infección y las 2 etapas quirúrgicas.
Resultados: Se incluyeron 10 pacientes (4 hombres y 6 mujeres, edad promedio 62 años). Causas iniciales: degenerativas (2 casos) y traumáticas (8 casos). Se realizaron 4 aloprótesis y 2 colgajos de dorsal ancho. Se identificaron 2 grupos: A (defectos óseos <4 cm) y B (>4 cm). El seguimiento fue de 5 años. La flexo-extensión fue de 117°/29° en el preoperatorio y 130°/29° en el posoperatorio; los puntajes de dolor fueron 6,5 y 2,5 (EAV); 40 y 80 (MEPS); y 56 y 30 (DASH), respectivamente. La fuerza de extensión fue de M5 (4 casos), M4 (2 casos), M3 (1 caso), M1 (2 casos) y M0 (1 caso). Un paciente tuvo una necrosis del colgajo que evolucionó con infección y 9 no tenían infección al final del seguimiento. Los pacientes del grupo A tenían menos cirugías previas y mejores resultados funcionales.
Conclusiones: El tratamiento de un proceso infeccioso de codo mediante un espaciador de cemento con antibiótico permite controlar la infección en un alto porcentaje de los casos. La reconstrucción protésica secundaria es demandante y se asocia a complicaciones. Cabe esperar que, cuanto más grande sea el defecto óseo y mayor la cantidad de procedimientos previos, los resultados funcionales sean peores.
Nivel de Evidencia: IV
Actualización del tratamiento de las fracturas intertrocantéricas
Authors: Pereira Sebastián , Vindver Gabriel , Bidolegui Fernando
Published: April 2021

Las fracturas intertrocantéricas representan el 50% de todas las fracturas del fémur proximal y su incidencia aumenta debido a la mayor expectativa de vida de la población. La reducción y fijación con un clavo de fémur proximal es el tratamiento de elección. Sin embargo, la falla de la osteosíntesis genera un aumento en la morbilidad y mortalidad, especialmente en el grupo de pacientes más añosos. Numerosos estudios señalan que los principales factores predictivos de falla están relacionados con errores de reducción de la fractura o con una incorrecta colocación del implante. Estos errores pueden ocurrir en distintas etapas de la técnica quirúrgica, como la planificación preoperatoria, la ubicación del paciente, la visualización y la reducción de la fractura, la ubicación del punto de ingreso y la colocación del clavo, y el posicionamiento del elemento (tornillo o lámina) cefálico. Por lo tanto, sobre la base de la bibliografía disponible y las más de 1000 fracturas intertrocantéricas tratadas con clavos de fémur proximal desde abril de 2002 hasta mayo de 2020, nos proponemos describir los posibles errores durante la técnica quirúrgica y ofrecer una guía sistematizada para evitarlos. Conclusiones: A pesar del gran avance y desarrollo de implantes en los últimos años, los principales factores determinantes del resultado final de la fijación de las fracturas intertrocantéricas siguen siendo la calidad de la reducción y el correcto posicionamiento del implante. Conocer los diferentes errores que se pueden producir durante cada uno de los pasos de la técnica quirúrgica resulta indispensable para poder evitarlos.
NUMERICAL SOLUTION OF GEOMECHANICAL PROBLEMS (THE CASE OF THE BALTIC SEA SHELF FIELD)
Authors:   PermNIPIneft branch of LUKOIL-Engineering LLC in Perm, Liadova Nadezhda A. , Klykov Pavel I. ,   PermNIPIneft branch of LUKOIL-Engineering LLC in Perm, Predein Andrei A. ,   PermNIPIneft branch of LUKOIL-Engineering LLC in Perm
Published: April 2021

Geomechanical modeling aims at solving problems associated with ensuring accident-free well drilling. The paper deals with building a numerical 3D geomechanical model for a studied field with a further production well stability computation. The region of operations is located in the Baltic Sea shelf. Apart from the field summary, the study contains results of acquisition and audit of initial data for modeling. The method is discussed for unidimensional geomechanical modeling on key wells, including determination of dynamic and static elasticity and strength of the rock varieties, computations of pore pressure, vertical and horizontal stresses. Well stability computations have been obtained and analyzed on the basis of the findings of 1D geomechanical modeling. A further analysis deals with the results of 3D geomechanical modeling, i.e. determination of boundaries and building a structural framework of the model, geometry testing, filling the grid with mechanical properties, and computation of complete stress tensor using the finite element method (FEM). Results of the 1D- and 3D-modeling have been compared. Thus, a numerical 3D geomechanical model has been built for the field under study. The following stage of works was focused on the wellbore stability computation for the planned wells. Additionally, computation was performed for drilling mud absorption pressure gradient cubes, caving pressure, and rock hydraulic fracturing pressure at different inclination angles and drilling azimuths. Recommendations were developed for accident-free construction of wells in the field under study, including upkeep and update of the geomechanical model in real time during drilling of wells. The obtained results and techniques can be used in design and construction of wells in other fields though taking into account regional specifics.
WAYS OF IMPROVING THE FORMATION HYDRAULIC FRACTURING EFFECTIVENESS IN CARBONATE DEPOSITS OF FIELDS OF THE REPUBLIC OF KOMI AND NENETS AUTONOMOUS OKRUG
Authors:   PermNIPIneft branch of LUKOIL-Engineering LLC in Perm, Novokreshchennykh Dmitrii V. , Raspopov Aleksei V. ,   PermNIPIneft branch of LUKOIL-Engineering LLC in Perm
Published: April 2021

The study presents an overview of the formation hydraulic fracturing application in carbonate deposits of fields of the Republic of Komi and Nenets Autonomous Okrug. The formation hydraulic fracturing technology has become widely used in carbonate reservoirs since 2012, with over three hundred well jobs performed. A significant share of residual recoverable reserves in carbonate deposits needs to be withdrawn; production rates need to be increased, inter alia, by way of the formation hydraulic fracturing. In the conditions of gradual deterioration of porosity and permeability of candidate wells, maintaining a steady level of technological effectiveness of hydraulic fracturing is ensured by implementing new technologies and optimizing standard processes. The hydraulic fracturing implementation issues are inextricably connected to the main issues of oilfield developments and specific structural features of carbonate reservoirs. Taking into account the specific structural features of carbonate reservoirs and existing development issues, the main objectives of the formation hydraulic fracturing have been determined: fracture conductivity increase; horizontal and vertical sweep increase; reduction of uncontrolled leakage of fracturing fluid; reduction of fracture height in conditions of adjacent water- and gas-saturated interbeds. Presently, a number of technologies has been successfully adapted and is used at the Republic of Komi and Nenets Autonomous Okrug sites. Due to the implementation of the integral approach to selection of the hydraulic fracturing technology modifications, taking into account the existing oilfield development issues and structural peculiarities of carbonate reservoirs, the reliable effectiveness of the method has been ensured in the conditions of deteriorating candidate wells; the technology application range has been extended. The study suggests expanding the range of the existing laboratory analyses to include such aspects as determination of stress intensity factor – fracture resistance and Biot’s poroelastic parameter, study of leakage rate dynamics in regard to various fracturing fluids, depending on the reservoir properties of core samples at given gradients, determination of dependence of proppants dynamic transfer on rheological properties of fracturing fluids and their filtration rates for various degrees of fracture model opening.
EXPERIENCE OF OILFIELD DEVELOPMENT IN PERM KRAI USING HORIZONTAL WELLS
Authors:   PermNIPIneft branch of LUKOIL-Engineering LLC in Perm, Zaitcev Roman A. , Raspopov Aleksei V. ,   PermNIPIneft branch of LUKOIL-Engineering LLC in Perm
Published: April 2021

Hydrocarbon reservoir engineering has a top priority to achieve the highest possible value of the cost-effective oilrecovery factor. Structural deterioration of residual oil reserves and inevitable development of hard-to-recover reservesrequire new effective technologies and engineering solutions. Today, there is a tendency to replace the standard sizewell drilling technologies (including vertical, directional, horizontal, multilateral wells) and standard size dualcompletion equipment usage by slim-hole drilling technologies. In Perm Krai fields, more than 385 horizontal wellshave been drilled, while 3.4 % of them, i.e. 13 wells, have a small diameter. The conducted well operation analysisshows that the effectiveness of the horizontal well operations in a number of instances is significantly lower than thepotential one. This leads to a deteriorated economic performance of reservoir developments, and, eventually, to assetvalue reductions. Perhaps, the main reason of low effectiveness of the horizontal well operations lies is an insufficientunderstanding of geological and physical conditions of their successful operations. It has become obvious that drillinghorizontal wells in reservoirs with high compartmentalization, low net oil thickness, and decreased hydrodynamicconnectivity to the edge water zone offer a low level of performance. Productivity tends to decrease to average outputvalues of directional wells. Therefore, the problem of choosing a well design and its direction in specific geological andphysical conditions is highly relevant.
INFLUENCE OF THE ANIONIC COMPOSITION AND ACID GAS CONTENT IN FORMATION WATERS OF PERM KRAI FIELDS ON CORROSION INHIBITOR EFFECTIVENESS
Authors:   Perm National Research Polytechnic University, Ladygin Aleksandr N.
Published: April 2021

In the course of hydrocarbon deposit development, formation water starts entering the wells over time. An increasing produced water volume has a negative impact on economic indicators of oilfield developments and leads to other hazardous consequences, such as equipment corrosion. Downhole equipment corrosion causes largest financial losses, since well accidents entail expensive repairs. Therefore, it is critical to prevent the equipment corrosion. The study considers main properties and composition of formation waters. Based on an overview of open literature sources, we analyzed the impact of Cl–, SO4 –2, HCO3 – anions contained in the formation waters on corrosion process kinetics at the phase interface between metal (electrode) and water (electrolyte). The study also discusses the results of researches on the influence of dissolved acid gases (H2S and CO2) on corrosion mechanisms and rates. An influence of pH value on the corrosion rate is considered. Contents of various salts in the formation waters contribute to the complexity of corrosion processes occurring in real conditions. Presence of aggressive environments can accelerate corrosion in some instances, but sometimes it can slow it down; this fact also affects the inhibitor protection effectiveness. Based on laboratory analysis data, effectiveness of using the corrosion inhibitor in the formation waters with different compositions and properties is assessed. It has been established that presence of a mix of aggressive components – chloride ions and hydrogen sulfide – in the formation waters causes hydrogen sulfide corrosion inhibition and reduction of chloride corrosion rate. Presence of dissolved salt ions and acid gases in the formation waters improves effectiveness of the corrosion inhibitors due to strong passive films formed on steel equipment surfaces.
Analysis of Petrophysical Studies of Deep Oil and Gas Reservoirs of Onshore and Offshore Fields in Azerbaijan
Authors:   Azerbaijan National Academy of Sciences Institute Oil and Gas, Gurbanov Vagif Sh. , Sultanov Latif A. ,   Azerbaijan State Oil and Industry University, Gulueva Nurlana I. ,   Azerbaijan National Academy of Sciences Institute Oil and Gas
Published: April 2021

The paper presents results of generalized laboratory studies from an array of petrophysical parameters of reservoir rocks (potential hydrocarbon reservoirs). The study is targeted at well-known horizons of productive strata of the Meso- Cenozoic sedimentary basin. The area under study includes oil and gas onshore and deep offshore fields in Azerbaijan that have been under active continuous developments. The development of these natural hydrocarbon accumulations has over a century-long history, which has shown that the major oil and gas deposits are associated with the South Caspian and Kura depressions subjected to an intensive submersion over the Meso-Cenozoic period. Although many of the fields in these depressions have been exploited for a long time, the commercial potential is high enough, especially in deep-seated areas. Nonetheless, problems associated with extracting oil and gas therefrom are pending final resolutions. Subsoil developments in the region are currently performed at an intensive rate at depths above 4-4.5 km, since most oil and gas deposits have already been explored at shallow and moderate depths (even in hard-to-reach areas). As known in oil industry, the wells with a depth of over 4 km are referred to deep wells, while those with a depth of over 6 km are referred to ultra-deep wells. Moreover, drilling of such wells is associated with serious costrelated challenges. For example, the cost of developing deep and even ultra-deep wells is high enough, ranging from $ 2-3 to $ 9-12 million. This fact emphasizes the need to enhance efficiency of such operations, which requires a highscale geological reasoning of a field’s potential and choice of a good location.
Studying the Wellbore Stability Enhancement Mechanism during Drilling through Fractured Argillites
Authors:   Saint Petersburg Mining University, Nutskova Mariia V. , Chudinova Inna V. ,   Saint Petersburg Mining University, Sobolev Aleksandr N. ,   Saint Petersburg Mining University
Published: April 2021

The paper presents the relevance of enhancing wellbore stability by developing and applying efficient drilling fluid compositions for well constructions in fractured argillite. In the process of well constructions, there comes a range of complications associated with instability of rocks forming borehole walls, which sometimes results in lower penetration rates, higher construction costs and well abandonment. Often, drilling problems occur at drilling through mudrocks that account for up to 70 % of field sections. When using water-base drilling fluids, the mudrock swelling due to the contact with the fluid dispersion medium adversely affects the drilling process and can significantly increase well construction costs. The accumulation of wellbore cavings inhibits well circulation, causes landing of drilling tools and may result in tool sticking. An analysis of drilling problems in fractured argillite is presented; the mechanisms affecting open hole stability in the fractured argillite deposits are shown. The use of potassium chloride is recommended to enhance the stability of argillite-formed borehole walls. The results are supported by experimental studies using the Chenevert method, as well as fracture propping tests. When the argillite sample was placed in potassium chloride (KCl) solution, there was a minor fracture expansion and propagation over the entire sample length, which is a positive result. To enhance wellbore stability, further study approaches are proposed: upgrading mud by adding inhibiting compounds, such as salt solutions in combination with high-molecular polymer compositions.
Ensuring Occupational Safety and Health through Ventilation in Underground Mines with Internal Combustion Engine Vehicles on Duty
Authors:   Federal State Budgetary Institution of Science Mining Institute of the Ural Branch of the Russian Academy of Sciences, Grishin Evgeniy L. , Zaitsev Artem V. ,   Federal State Budgetary Institution of Science Mining Institute of the Ural Branch of the Russian Academy of Sciences, Kuzminykh Evgeniy G. ,   Federal State Budgetary Institution of Science Mining Institute of the Ural Branch of the Russian Academy of Sciences
Published: April 2021

Increasing production capacities and developing ventilation systems in underground mines challenge mining enterprises to enhance the output level of applied mining and ventilation facilities. Most of the rock loading and transporting mining machinery at ore deposits is powered by diesel internal combustion engines. Insufficient ventilation or wrong approaches to determining the amount of air required to dilute the main components of exhaust gases from internal combustion engines, including carbon monoxide and nitrogen oxides, can result in poisoning or even death of mining workers. However, most production facilities make their ventilation systems operate at the capacity limits without any opportunities to increase their technical reserves. This fact has a direct impact on safety of mining operations. We present methods and equations aimed at determining the required air quantity for the operating areas of the vehicles equipped with internal combustion engines and the underground mines at their designing and operation stages. The analysis of regulatory documentation shows that there is no requirement to airflow rate per power unit of internal combustion engines. Therefore, we propose an approach that meets up-to-date industrial safety requirements based on the actual emissions of harmful components, performance parameters of internal combustion engines and emission standards guaranteed by manufacturers though confirming an engine’s emission class compliance. The proposed methods will allow us to enhance workplace safety at underground mines where internal combustion engine equipment is on duty, and to increase the efficiency of designing new blocks, horizons and mines by eliminating unreasonable reserves when selecting mining and ventilation equipment.
Species composition and distribution of seaweeds in Phu Yen province
Authors: Hang Nguyen Thi Thu , Tu Nguyen Van , Phu Vo Van , Lam Nguyen Ngoc
Published: April 2021

Results of four field surveys, conducted from June 2017 to June 2018 found that in the Phu Yen coastal water, a total of 103 seaweed species have been recorded, increasing the total number of seaweed species in Phu Yen province to 133 species, with 81 newly recorded species for Phu Yen geographic area. Among 103 seaweed species, 4 species belong to Cyanobacteria, 38 species belong to Rhdophytes, 24 species belong to Phaeophytes, and 37 species belong to Chlorophytes.  The number of species at surveyed sites V1 to V9 varies from 3 species/site (V3) to 83 species/site (V7) and on average 27 species/site. Sørensen’s similarity coefficient varies from 0.05 (between V3 and V7) to 0.86 (V3 and V4) and on average 0.25. 74/103 species were collected in the littoral zone, 67 species in sublittoral zone and most of them are distributed at 0-4 m water depth of subtidal zone. The marine algal flora is represented by mixing of subtropical and tropical characteristics as Cheney index was 3.
Some species of macro-gastropods in the coastal zone of Khanh Hoa province
Authors: Nghi Bui Quang , Ngan Nguyen Thi My , Phu Nguyen Kha
Published: April 2021

From November 2013 to March 2014, 104 species were collected, belonging to 27 families, 58 genera of Gastropoda in coastal area of Khanh Hoa province. Some families have a large number of species such as Conidae - 15 species; Strombidae - 15 species; Cypraeidae - 10 species; Terebridae - 7 species and Muricidae - 6 species. Many species of economic value are used for food and fine arts. 11 species are listed in Vietnam Red Data Book. Besides, images and information of samples (collecting date, place of sample collection,...) are presented.
Variation of phytoplankton community structure in Quang Ngai coastal waters during 2015–2019
Authors: Duyen Huynh Thi Ngoc , Hue Tran Thi Minh , Van Tran Thi Le , Luom Phan Tan , Lam Nguyen Ngoc , Hai Doan Nhu
Published: April 2021

Phytoplankton in coastal waters are important for the evaluation of either biodiversity or environmental impacts because of this highly vulnerable ecosystem. Seasonal and annual changes in the phytoplankton community structure in Quang Ngai waters during the period 2015 to 2019 were analyzed to assess the phytoplankton diversity and reveal possible causes of these changes. A total of 366 phytoplankton taxa belonging to 10 classes were identified throughout this present study. The highest species number was found in 2019 with 295 taxa, followed by those in 2015 (247), 2017 (185), and 2018 (99). The waters of Ly Son transect showed the highest diversity and most stable phytoplankton communities in both dry and rainy seasons, whereas the stations of Quang Ngai coast revealed high variability of the communities. All diversity indices including Margalef, Pielou, Shannon, Simpson did not reflect well differences in average values but a certain degree of variances, indicating possible environmental impacts. During the study time, there were blooms of certain diatom species including Skeletonema spp. in 2015 and Pseudo-nitzschia spp. in 2019. Analysis of a diatoms index, Centric/Pennate ratio, indicated that the waters were in eutrophic status with a decreasing trend from the coast area to Ly Son island in 2015 and 2019. This research built up fundamental data on phytoplankton communities for Quang Ngai province. The Centric/Pennate diatom index and diversity would be used as indicators for environmental changes and their values provided warning of eutrophication in this coastal waters including the water surrounding Ly Son island.